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FIELD OF THE INVENTION
[0001] The present invention relates to modular conveying apparatus.
BACKGROUND OF THE INVENTION
[0002] Sprockets for driving modular belts are usually made from stainless steel or plastic that is machined or molded. In food processing applications, sprocket drives are a particularly critical area for cleaning. It is important to be able to periodically remove the residual matters totally from the sprockets and on the rear side of the belt, in order to avoid bacteria growth and spoilage of the food processed on the belt. For this purpose sprockets have been designed with large openings to allow cleaning fluid to pass from the side and reach the critical areas to be cleaned. Such sprockets are disclosed in U.S. Pat. No. Re. 38,607. Typically, the sprocket rim and teeth are covering the hinges and hinder the fluid from reaching the hinge area for proper cleaning. Therefore the sprocket disclosed in the patent further provides pairs of teeth in a double row such that the teeth of a pair are offset. This arrangement allows better cleaning access to the rear belt side and easier release of residual matters collected on the rear belt side. But this design is only partially solving the problem since the critical hinge areas are still covered by the sprocket rim to a certain extent, when engaged on the sprocket. Therefore good access to these hinges is of primary importance.
[0003] U.S. Patent Publication No. 2004/0222072 proposes to solve this problem by using a sprocket with an oblique shape as illustrated in FIGS. 3A , 3 B of the publication. With this design, the teeth will laterally change their position on the rear side of the belt and regularly expose another place on the belt for better cleaning access. Although this is improving cleanability, the proposed solution is still having the shortcoming of periodically covering the hinge completely in a certain position. Another typical feature of the disclosed sprocket is the tracking on the belt by additional teeth engaging in the hinge gaps ( FIG. 3B , reference no. 74 ). During sprocket engagement these teeth enter into the hinge gap between two links and thus push residual matter into this gap, making it again difficult to clean. Also, the drive pockets (reference 72 as shown in FIG. 3A of the publication) of the sprocket are engaging closely over the drive faces which are identical with the center cross bar on the rear side of the belt. The drive surfaces totally covered by the enclosing drive pocket are another place where residuals are physically squeezed in between thus making cleaning more difficult.
[0004] Another patent proposing a similar solution is U.S. Pat. No. 6,740,172. The patent does not disclose the drive engagement but discloses sectional sprockets used to laterally shift the engagement area periodically. Accordingly, there is a need for an improved sprocket for easy cleaning that avoids the above described shortcomings.
SUMMARY OF THE INVENTION
[0005] The present invention meets the above described need by providing a drive sprocket for driving a modular belt having a plurality of belt modules with intercalated link ends connected by transverse pivot members to form hinges. The belt modules may have transverse ribs. The drive sprocket is driven by a shaft. The drive sprocket has a central opening for receiving the shaft. The body has a plurality of teeth disposed in pairs along a periphery of the body. The body has a first opening formed between adjacent pairs of teeth and extending toward the center of the sprocket to provide access to the hinge area, when the belt engages with the sprocket, for application of cleaning fluid.
[0006] The sprocket may also be provided with a curved recessed portion adjacent to the first opening. A plurality of second openings may be disposed in the body of the sprocket between the central opening and the first opening.
[0007] The pairs of teeth may be arranged in offset fashion with respect to a central axis or the teeth may extend for the entire with of the sprocket.
[0008] A cleaning system may be arranged proximate to the sprockets such that cleaning fluids are sprayed through the curved recessed portion into the opening disposed adjacent to the hinge of the belt when the belt engages with the sprocket. The cleaning system may include a manifold in combination with spray heads pointed toward the sprocket.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The invention is illustrated in the drawings in which like reference characters designate the same or similar parts throughout the figures of which:
[0010] FIG. 1 is a side elevational view of a sprocket according to a first embodiment of the present invention;
[0011] FIG. 2 is an end elevational view of the sprocket shown in FIG. 1 ;
[0012] FIG. 3 is a side elevational view of the sprocket shown in FIG. 1 with a modular belt engaged thereon;
[0013] FIG. 4 is a perspective view thereof;
[0014] FIG. 5 is another perspective view thereof;
[0015] FIG. 6 is an alternate embodiment of the sprocket of the present invention;
[0016] FIG. 7 is a side elevational view of another alternate embodiment of the present invention;
[0017] FIG. 8 is an end elevational view of the sprocket shown in FIG. 7 ;
[0018] FIG. 9 is a perspective view of the sprocket shown in FIG. 7 with a belt engaged thereon;
[0019] FIG. 10 is a side elevational view of another alternate embodiment of the present invention;
[0020] FIG. 11 is an end elevational view of the sprocket of FIG. 10 ;
[0021] FIG. 12 is a side elevational view of the sprocket of FIG. 11 with a modular belt engaged thereon;
[0022] FIG. 13 is perspective view thereof;
[0023] FIG. 14 is a schematic view of sprockets of the present invention in combination with a spraying system; and,
[0024] FIG. 15 is a side elevational view of another alternate embodiment of the present invention;
[0025] FIG. 16 is an end elevational view of the sprocket shown in FIG. 15 ; and,
[0026] FIG. 17 is a perspective view of the sprocket of FIG. 15 with a belt engaged thereon.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Referring initially to FIG. 1 , a drive sprocket 20 has a plurality of sprocket teeth 23 , 26 disposed in pairs 27 around the periphery of the sprocket 20 . The sprocket 20 also has a central opening 29 that is formed in the shape of a square. The square shaped opening 29 is sized to receive a square shaft 30 ( FIG. 14 ) for rotating the sprocket 20 to drive a modular belt 32 ( FIG. 3 ). The central opening 29 may be formed in other shapes to accommodate different shaft geometries as will be evident to those of ordinary skill in the art based on this disclosure. A large first opening 35 which may be oval-shaped as shown is formed in the body of the sprocket 20 . The first opening 35 is located between adjacent pairs 27 of teeth and is arranged such that it aligns with the hinge area of the module belt 32 when the belt 32 is engaged with the sprocket 20 as best shown in FIG. 3 . As shown the teeth 23 are formed by a pair of side walls 38 , 41 (opposite to wall 38 ); a pair of end walls 44 , 47 ; and a top wall 50 . The teeth 26 are formed by a pair of side walls 53 , 56 (opposite to wall 53 ); a pair of end walls 59 , 62 ; and a top wall 65 . The top walls 50 and 65 are angled relative to their respective side walls such that the top walls 50 and 65 are disposed in spaced apart relation and somewhat aligned with respect to their planar top surfaces. The sprocket 20 also has recessed curved portions 68 extending from the end of the first openings 35 toward the center of the sprocket 20 . The curved recessed portions 68 extend toward the teeth 23 , 26 and terminate at a shelf-like portion 71 between the respective teeth.
[0028] Turning to FIG. 2 , the teeth 23 , 26 are disposed in two rows along the periphery of the drive sprocket 20 . The teeth 23 , 26 are offset along the circumference of the sprocket and are disposed on opposite sides of a central axis 28 such that during driving of the modular belt 32 one of the teeth engages with one of the link ends 33 of the belt 32 and another tooth engages with the transverse rib 34 on the belt 32 . The shelf portion 71 extends between adjacent teeth 23 , 26 and is bordered on opposite sides by the curved recessed portions 68 .
[0029] Turning to FIG. 3 , the sprocket 20 is shown engaged with the modular belt 32 . The teeth 23 , 26 engage with the link ends 33 and transverse rib 34 of the respective belt modules 36 . The teeth 23 , 26 fit on opposite sides of the transverse rib 34 and provide tracking for the belt 32 . Also, the first openings 35 provide large openings and improved access to the hinge areas for cleaning when the belt 32 passes over the drive sprocket 20 . The curved recessed portions 68 also provide room near the hinge and guide the cleaning fluid into the critical hinge area.
[0030] Turning to FIGS. 4 and 5 , the end wall 47 of the tooth 23 may be disposed at an angle such that the face of the tooth 23 reduces the contact surface to the belt 32 and “squeezes” away residuals that may become trapped between the belt 32 and the sprocket 20 .
[0031] In FIG. 6 , an alternate embodiment of the sprocket 20 is shown. Sprocket 60 has the same design for the teeth 23 , 26 and the first openings 35 and curved, recessed portions 68 but also includes openings 63 which are relatively large and are positioned around the periphery of the central shaft opening. The openings 63 may be desired to improve the accessibility for water jets applied from the sides of the sprocket 60 . This alternate design does not necessarily improve the cleaning of the hinge areas.
[0032] Turning to FIGS. 7-9 , an alternate embodiment of the sprocket body that is particularly suitable for molding is shown. Sprocket 80 has a central opening 81 and has larger curved, recessed portions 83 that follow the offset (with respect to the circumference as best shown in FIG. 8 ) arrangement of the sprocket teeth pairs 86 , 89 . The teeth are disposed in pairs 91 with each tooth on opposite sides of a central axis 94 . The curved recessed portion 83 extends from the end wall 92 of one tooth 86 to the end wall 95 of the next tooth 86 on the same side of the sprocket 80 . A first opening 98 formed between adjacent teeth 86 , 89 provides an opening around the hinge area. The pairs 91 of sprocket teeth 86 , 89 provide for engagement of the transverse rib 34 and link end 33 of belt 32 as shown in FIG. 9 . The recessed portion 83 is disposed at an angle β with respect to the radial axis 93 . The angle β may be altered as necessary to improve the flow of cleaning fluid.
[0033] Turning to FIGS. 10-13 , an alternate embodiment of the sprocket is shown. Sprocket 110 has a central opening 114 . Sprocket 110 increases the open space between the sprocket 110 and the hinge of the belt 32 . The sprocket 110 may be used where tracking is not needed such as where the belt 32 is guided by guiding profiles on the edge of the belt 32 . As best shown in FIG. 11 , the sprocket 110 has a single row of teeth pairs 113 , 116 without any offset. Due to the wider teeth 113 , 116 and the closed V-shape of the space 118 between the teeth 113 , 116 , the sprocket 110 contact area is larger and may negatively effect the cleaning properties of the sprocket 110 . The sprocket 110 also includes a curved, recessed portion 121 . The recessed portion 121 extends to a first opening 124 that aligns with the hinge area of belt 32 as shown in FIG. 12 .
[0034] FIG. 14 illustrates an arrangement of a spraying system include a manifold 150 with spray heads 153 arranged adjacent to sprockets 20 such that cleaning fluid 156 can be sprayed through the curved recessed portions 68 into the first openings 35 below the hinge areas of the modular belts 32 as they pass over the drive sprocket 20 .
[0035] Turning to FIG. 15 , another embodiment of the sprocket is shown. A drive sprocket 200 has a plurality of sprocket teeth 203 , 206 disposed in pairs 207 around the periphery of the sprocket 200 . The sprocket 200 also has a central opening 209 that is formed in the shape of a square. The square shaped opening 209 is sized to receive a square shaft 30 ( FIG. 14 ) for rotating the sprocket 200 to drive a modular belt 32 as shown in FIG. 17 . A plurality of first openings 215 are disposed around the periphery of the sprocket 200 between the pairs 207 . The first openings 215 extend inward toward the center of the sprocket 200 and terminate along a curved inner wall 218 . A plurality of second openings 221 are disposed between the first openings 215 and the central opening 209 . The second openings 221 may be desired to improve the accessibility of water jets applied from the sides of the sprocket 200 . Sprocket 200 does not include recessed portions or grooves below the first opening 215 . The sprocket 200 is intended to have smooth surfaces with large openings to provide access to the hinge area of the belt and to allow easier cleaning of the sprocket itself.
[0036] In FIG. 16 , the teeth 203 , 206 are disposed in two rows along the periphery of the drive sprocket 200 . The teeth 203 , 206 are offset along the circumference of the sprocket 200 and are disposed on opposite sides of a central axis 230 . During driving of the modular belt 32 one of the teeth engages with one of the link ends 33 of the belt 32 and another tooth engages with the transverse rib 34 on the belt 32 . The transverse rib 34 on the belt 32 fits in the space 238 between the teeth 203 , 206 .
[0037] Turning to FIG. 17 , the sprocket 200 is shown engaged with the modular belt 32 . The teeth 203 , 206 engage with the link ends 33 and transverse rib 34 of the respective modules 36 . The teeth 203 , 206 fit on opposite sides of the transverse rib 34 and provide tracking for the belt 32 . Also, the first openings 215 provide large openings and improved access to the hinge areas for cleaning when the belt 32 passes over the drive sprocket 200 . As indicated by arrow 250 the first openings 215 align with the hinge areas of the belt 32 as the belt 32 passes over the sprocket 200 .
[0038] While the invention has been described in connection with certain embodiments, it is not intended to limit the scope of the invention to the particular forms set forth, but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. | 4y
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FIELD OF THE INVENTION
This invention relates to articles comprising low thermal expansion composite materials and their manufacture, in particular, those composites containing components, such as ductile alloy bodies, with negative coefficients of thermal expansion.
BACKGROUND OF THE INVENTION
Electronic devices and their package structures consist of a variety of metallic, ceramic, plastic or composite components with vastly different coefficients of thermal expansion (CTE). Mechanical or electrical failures in such devices are often caused by thermal expansion mismatch among the materials during fabrication or service. High thermal conductivity materials such as Cu and Al, and their alloys, are commonly used as heat sink materials in high-density, high-power-dissipating electronic packages. Differences in coefficients of thermal expansion (CTEs) between the heat sink material (e.g. 15-18 ppm/° C. for Cu and its alloys, 22-25 ppm/° C. for Al and its alloys, and about 8 ppm/° C. for the commonly used “low-expansion” 25% Cu-75% W composite) and the silicon chip (2.8-4.2 ppm/° C.) to which it is attached can cause stresses in the electronic package leading to complex thermal stress failure mechanisms. These thermomechanical problems can be thermoelastic, thermoplastic and elastoplastic deformations involving time-dependent and dynamic processes like stress rupture, thermal shock, thermal fatigue, creep and stress relaxation, and can seriously impair the reliability of the device. The thermal stresses induced by CTE mismatches can cause p-n junction failure in chips, brittle fracture in Si, Ga—As, or other semiconductor substrates, bowing or delamination of the layered assembly and stress corrosion failure in metals. Therefore, minimizing the mismatch between the heat sink material and semiconductor substrates can lead to significantly greater device reliability.
It is desirable to have heat sink materials with low CTE values, e.g., α˜4 ppm/° C., nearly matching that of silicon, or α˜6 ppm/° C., nearly matching that of Ga—As. Composite structures with low CTEs, e.g., layered configurations consisting of copper and low CTE materials such as tungsten (α˜4.5 ppm/° C.), molybdenum (α˜5.2 ppm/° C.), or Invar (Fe-36 w % Ni, α˜1.2 ppm/° C.) have been demonstrated. See, for example, Zweben et al, Electronic Materials Handbook , Vol. 1: Packaging (ASM, Metals Park, Ohio, 1989), p. 1129. However, the volume fraction of the non-copper metallic element generally needs to be substantial, e.g. of the order of 60-90 volume %, to significantly reduce the CTE value of copper, thereby reducing the efficiency of the heat sink.
Accordingly, there is a need for improved composite materials, especially those which can act as a heat sink for semiconductor substrates with a minimum of thermal mismatch.
SUMMARY OF THE INVENTION
In accordance with the invention, a reduced CTE composite structure is made by providing a matrix material whose CTE is to be reduced, adding negative CTE bodies to the matrix material and mechanically coupling the matrix material to the negative CTE bodies as by deforming the composite structure. A preferred application is to make an improved composite material for use as a heat sink for semiconductor substrates with a minimum of thermal expansion mismatch.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages, nature and additional features of the invention will appear more fully upon consideration of the illustrative embodiments and experimental data described in the accompanying drawings. In the drawings:
FIG. 1 is a block diagram of the steps involved in making a reduced CTE composite structure;
FIGS. 2A-2F schematically illustrate typical shaped negative CTE bodies added to matrix material;
FIG. 3 illustrates deforming a composite body using a roller mill;
FIG. 4 illustrates deforming using a drawing die;
FIG. 5 illustrates production of a composite structure having reduced CTE in two or three dimensions;
FIGS. 6A and 6B illustrate deformation of powdered composite bodies;
FIG. 7 illustrates a semiconductor device having an improved heat sink;
FIG. 8 shows the thermal expansion curve of a first exemplary material; and
FIG. 9 is a thermal expansion curve for an exemplary composite structure.
It is to be understood that the drawings are for purposes of illustrating the concepts of the invention and, except for the graphs, are not to scale.
DETAILED DESCRIPTION
Referring to the drawings, FIG. 1 is a block diagram of the steps involved in exemplary process for making a reduced CTE composite structure. The first step shown in block A is to provide a matrix material whose CTE in one or more dimensions is to be constrained. The matrix material will typically have a positive CTE. The matrix material can be a metal, polymer, plastic, ceramic, glass or epoxy material. In a preferred application it is a metal, such as copper, having desirable heat sink properties but an undesirably large CTE for important applications. The matrix material can be a block with machined holes, a porous block or even a collection of rods or an aggregation of powder.
The next step shown in block B is to add, within the matrix material, bodies of a negative CTE material. This can be accomplished in a variety of ways. If the matrix has machined holes, the negative CTE material can be added as rods, bars, strips or wires. Preferably the bodies are roughened, shaped or serrated to facilitate strong mechanical coupling with the matrix material. Roughness or serrations can be produced by machining, grinding, shot blasting, patterned etching or the like. If the matrix material is a powder, the low CTE material can be added as shaped bodies or a powder.
The negative CTE material advantageously has a large negative CTE of at least (in a negative value) −0.1 ppm/° C., preferably at least −5 ppm/° C., even more preferably at least −20 ppm/° C. An example of such an advantageous alloy is Ni—Ti with a composition near 56 wt % Ni and 44% Ti.
The desirable serration or roughness on the surface of the negative CTE bodies has a depth of at least 1% of the thickness or width of the negative CTE body, and preferably at least 5% of the thickness or the width. Alternatively, one can use a geometrically nonlinear (bent) configuration of the negative CTE rods, wires or flakes. Desirably, at least a portion of the length of the negative CTE body is bent by at least 20 degrees in at least one location. The bending can be straight, curved, random or a mixture of these in any given composite. Such a bent configuration provides enhanced mechanical coupling of the two materials during thermal expansion or contraction of the composite. FIGS. 2A through 2F illustrate typical bodies of matrix material 20 to which shaped negative CTE bodies 22 have been added.
The third step (block C) is to mechanically couple the matrix material with the negative (TE material so as to reduce the CTE of the composite structure. The mechanical coupling can be achieved by mechanical deformation of the composite structure. Compressive deformation provides compaction, reduced dimension and ensures strong mechanical coupling of the component materials. For example, a matrix body containing serrated rods can be plastically deformed as by press-forming or plate rolling. FIG. 3 illustrates the step whereby a composite body 20 of matrix material 21 and negative CTE bodies 22 is deformed by the rollers 23 of a rolling mill to produce a composite structure 24 with strong mechanical coupling between the components.
Alternatively, the structure can be deformed by rod processing such as swaging, rod rolling or wire drawing. FIG. 4 shows deformation wherein the composite body 20 is deformed by a size reducing drawing die 30 .
If the matrix material is not plastically deformable as in the case of polymer, plastic, ceramic or epoxy glass material, a tight coupling can be achieved using thermal differential contraction, e.g., by inserting the negative CTE body into holes in the matrix material at a temperature higher than the maximum anticipated service temperature (preferably 50° C. higher). During cooling, the matrix material will shrink while the negative CTE body will expand, leading to mechanical locking. Curing or solidification of liquid matrix (e.g., uncured epoxy) with the negative CTE bodies embedded therein will produce a similar locking effect.
The composite material containing the negative CTE bodies is expected to have highly anisotropic mechanical and thermal expansion properties. The CTE reduction occurs in the direction of alignment of the negative CTE bodies, and hence they are preferably arranged along the direction of thermal expansion to be managed. If a two-dimensional, three-dimensional, or isotropic reduction of CTE is needed, the negative CTE bodies can be arranged either at an inclined angle or a diagonal angle (in a three-dimensional rectangular body). Subsequent deformation and compaction will result in either two-dimensional (x-y, y-z, x-z) or three-dimensional (x-y-z) reduction the CTE of the matrix material. FIG. 5 illustrates the effect of deformation on a composite body 20 with inclined bodies 22 to produce a composite structure 24 having reduced CTE in at least two dimensions.
Instead of inserting rods of the negative CTE material in the matrix preform, a multitude of rods, bars or strips of matrix material (positive CTE elements) and rods, bars or strips of negative CTE material can be bundled together, placed in a metallic jacket, e.g. of the positive CTE material, and uniaxially deformed by rod drawing, swaging, rolling, etc.
Yet another method of fabricating the composite structure is to use a powder metallurgy processing. For example, powders of Cu and powders of the negative CTE material (e.g. Ti—Ni) can be co-compacted, sintered, or uniaxially deformed (by rolling or rod drawing and roll flattening) to produce a composite with anisotropically reduced CTE. A random distribution of elongated particles or short fibers in the preform produces, after deformation, nearly isotropic CTE reduction. The composite structure as processed by plastic deformation may be given a post-annealing heat treatment, if desired, to relieve residual stress. FIG. 6A illustrates deformation of a powdered composite body 20 to produce a composite structure 24 of anisotropic CTE. FIG. 6B illustrates deformation to produce a structure 24 of isotropic CTE.
FIG. 7 illustrates the preferred application of the invention to produce a semiconductor device 60 with an improved heat sink 61 . The semiconductor device 60 can comprise a microelectronic circuit or an active optical device 62 on a semiconductor substrate 63 . The heat sink 61 can be fabricated in accordance with the process of FIG. 1 to closely match the thermal properties of the semiconductor substrate 62 . The substrate 62 is attached to the heat sink 61 as by a thin layer 64 of solder or epoxy.
The preferred composition range of the Ni—Ti based negative CTE body is typically about 48-64 weight % Ni, with the balance Ti, and preferably 52-60% Ni, with the balance Ti. Othier alloying elements such as V, Cr, Mn, Fe, Co, Mo, Nb, Ta, W, Pd, Cu, and Zn may also bel present in an amount less than 5 wt %, as long as the temperature range of phase transformation is near ambient temperature, e.g., between −150° to +150° C. range, and preferably in the −200° to +200° C. range. Other alloys with phase transformation occurring near ambient temperature may also be used, for example, Cu—Al—Zn (1-10 wt % Al, 20-40% Zn, balance Cu), Au—Cu—Zn (10-30% Cu, 20-40% Zn, balance Au), Cu—Zn—Si (30-40 wt % Zn, 0-20% Sn, balance Cu), Cu—Al—Ni (10-20% Al, 1-5% Ni, balance Cu), Cu—Zn—Sn (30-45% Zn, 0-20% Sn, balance Cu), and Cu—Sn (20-30% Sn, balance Cu).
For a desirably large coefficient of thermal expansion, the phase transformation near ambient temperature (e.g. at the −150° to +150° C. range, and preferably in the −200° to +200° C. range) is advantageous. It has been found that a large negative CTE in a desirably wiide temperature range (e.g. at least over 100° C. range near room temperature) is more easily obtained in these materials if uniaxial tensile deformation, such as wire drawing or rod drawing, is used. The exact mechanism for this behavior is not clearly understood. The desired uniaxial deformation is at least 2% elongation in length, preferably 5% or more elongation, even more preferably 10% or more.
The invention can be more clearly understood by consideration of the following specific examples.
EXAMPLE 1
For the fabrication of a Cu composite with a reduced CTE, a Ti—Ni alloy rod with a nominal composition of 56% Ni and 44% Ti (wt %) was wire drawn to a diameter of 2.16 mm and was used as the negative CTE body. The Ti—Ni rod was inserted into a copper tube (˜4.8 mm OD and ˜3.2 mm ID) and these were swaged together using 4.24 mm, 3.76 mm, and 3.35 mm diameter dies successively. Before swaging, shallow circumferential notches spaced about 0.5-1 mm apart were cut on the surface of the Ti—Ni rods with a rotary carbide tool to improve interlocking with the Cu during swaging. The resulting composite structure consisted of a Ti—Ni alloy core with a tight cladding of Cu around it. The volume fraction (V f ) of the Ti—Ni in the composite was estimated to be ˜0.35. The composite rod was cut into specimens measuring 3 mm in length for dilatometry. A Netzsch (Model 402 E) dilatometer with a fused silica push rod and type-J thermocouples was used for studying the thermal expansion characteristics. Heating was at a rate of 5° C./min. and cooling was through forced air convection.
Shown in FIG. 8 is the thermal expansion curve for the 56% Ni-44% Ti (wt %) alloy rod. The material exhibits a negative CTE value between 25° C. and 100° C. of about −21 ppm/° C. and an average CTE between −100 to +100° C. of about −19 ppm/° C. The thermal expansion behavior of FIG. 8 is quite reproducible upon subsequent temperature cycling after initial stabilization cycling of a few times, with a variation of less than about ±10%.
Shown in FIG. 9 is the thermal expansion curve for the Cu—(Ti—Ni) composite rod with ˜65%, by volume of Cu (α˜17 ppm/° C.) and 35% of the negative CTE (α˜−21 ppm/° C.) Ti—Ni alloy. Also shown are the thermal expansion curves for Si and Cu for comparison. The composite material, in the temperature range of 25-100° C., exhibits a low average CTE value of α˜4 ppm/° C. This CTE value of ˜4 ppm/° C. is generally consistent with the calculated value of the composite of the positive expansion matrix Cu and the negative expansion Ti—Ni core, i.e.,
α(composite)=(17 ppm/° C.×0.65)+(−21 ppm/° C.×0.35)=+3.7 ppm/° C.
α(composite)=(17 ppm/° C.×0.65)+(−21 ppm/° C.×0.35)=+3.7 ppm/° C.
As is evident in the figure, the composite Cu material exhibits a much reduced CTE, almost comparable to that of Si. The thermal conductivity of the composite structure is expected to be a geometrical average of the two constituent materials (Cu and Ti—N), and is calculated to be
[(398 W/m.K)×0.65]+[(14 W/m.K)×0.35]=263.6 W/m.K.
A further advantage of the inventive composite materials is that because of the use of negative CTE bodies, a relatively large volume fraction of the matrix Cu of Al can be utilized as compared to the prior art composites utilizing zero CTE (e.g., Invar) or low CTE (e.g., W) elements. Accordingly, the inventive composites provide high thermal conductivity, which is desirable for thermal management applications. Because of the continuity in the Cu matrix material, it is expected that in a multi-filamentary distribution of the negative CTE bodies, the thermal conductivity and electrical conductivity of the composite is not likely to be highly anisotropic especially because of the dominance of Cu conductivity. Even higher thermal conductivity is expected in the inventive composites if Cu-based negative CTE elements such as Cu—Al—Zn alloys are used. The inventive low-CTE composites desirably have thermal conductivity of at least 45% of that of the matrix material, and preferably at least 60% of the matrix conductivity.
It is to be understood that the above described embodiments illustrate only a few of the many possible specific embodiments of the invention. Numerous variations can be made without departing from the spirit and scope of the invention. | 4y
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FIELD OF THE INVENTION
[0001] The present invention relates to a lock assembly.
[0002] The invention has been developed primarily for use with an electrically controllable and electrically powered mortice lock and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular use and is also suitable for use in other types of locks, such as surface mounted locks.
BACKGROUND OF THE INVENTION
[0003] Electrically controllable and/or electrically powered locks are known. Such locks must be set to operate as either fail safe or fail secure. A fail safe lock automatically reverts to an unlocked state when its power supply is interrupted, for example during a power failure. A fail secure lock automatically reverts to a locked state when its power supply is interrupted.
[0004] One disadvantage of such known locks is that, when set to operate as fail safe, they are o unable to be used to lock the door in the absence of power. This requires a security guard or a separate manual lock to secure the door until power is returned.
[0005] Another disadavantage of such locks is, when set to operate as fail secure, they are unable to be used to unlock the door in the absence of power. Door opening is then only possible using a key operated latch retract function. However, this only temporarily unlatches the door whilst the key is pivoted by a user and the door returns to locked in the absence of same. This is inconvenient as it departs from the normal operation of a door and can present a safety issue as only key holders can open the door.
OBJECT OF THE INVENTION
[0006] It is the object of the present invention to substantially overcome or at least ameliorate the above disadvantage, and/or to provide an alternative.
SUMMARY OF THE INVENTION
[0007] Accordingly, in a first aspect, the present invention provides a lock assembly including:
a lock bolt movable between a latching position and an unlatching position; a first hub adapted to move the lock bolt in response to movement of a first handle; a first electrically powered hub locker assembly positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the first handle, the first electrically powered hub locker assembly being connectable to a first power source; and a first manually driven assembly adapted for selectively preventing or allowing to transmission of power from the first power source to the first electrically powered hub locker assembly.
[0012] The lock assembly preferably includes a housing and the lock bolt, the first hub, the first electrically powered hub locker assembly and the first manually driven assembly are mounted within the housing.
[0013] The first manually driven assembly is preferably driven by a key or a turn button.
[0014] In one form, the first electrically powered hub locker assembly is adapted for powered driving in a first direction to a first position and biased driving in a second direction opposite to the first direction to a second position, wherein the first electrically powered hub locker assembly remains at, or returns to, the second position when the first manually driven assembly is driven to prevent transmission of power to the first electrically powered hub locker assembly.
[0015] In another form, the first electrically powered hub locker assembly is adapted for powered driving in a first direction to a first position and powered driving in a second direction opposite to the first direction to a second position, wherein the electrically powered hub locker assembly remains at the position it was occupying when the first manually driven assembly is driven to prevent transmission of power to the first electrically powered hub locker assembly.
[0016] The lock assembly preferably includes:
[0017] a second hub adapted to move the lock bolt in response to movement of a second handle,
[0018] wherein the first electrically powered hub locker assembly is positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the second handle.
[0019] The lock assembly preferably includes:
[0020] a second hub adapted to move the lock bolt in response to movement of a second handle; and
[0021] a second electrically powered hub locker assembly positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the second handle, the second electrically powered hub locker assembly being connectable to the first power source,
[0022] wherein the first manually driven assembly is adapted for selectively preventing or allowing transmission of power from the first power source to the second electrically powered hub locker assembly.
[0023] The lock assembly preferably includes:
a second hub adapted to move the lock bolt in response to movement of a second handle; and a second electrically powered hub locker assembly positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the second handle, the second electrically powered hub locker assembly being connectable to a second power source, wherein the first manually driven assembly is adapted for selectively preventing or allowing transmission of power from the second power source to the second electrically powered hub locker assembly.
[0027] In one form, the second electrically powered hub locker assembly is adapted for powered driving in a first direction to a first position and biased driving in a second direction opposite to the first direction to a second position, wherein the second electrically powered hub locker assembly remains at, or returns to, the second position when the first manually driven assembly is driven to prevent transmission of power to the second electrically powered hub locker assembly.
[0028] In another form, the second electrically powered hub locker assembly is adapted for powered driving in a first direction to a first position and powered driving in a second direction opposite to the first direction to a second position, wherein the second electrically powered hub locker assembly remains at The position it was occupying when the first manually driven assembly is driven to prevent transmission of power to the second electrically powered hub locker assembly.
[0029] The lock assembly preferably includes:
a second hub adapted to move the lock bolt in response to movement of a second handle; a second electrically powered hub locker assembly positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the second handle, the second electrically powered hub locker assembly, being connectable to a second power source; and a second manually driven assembly adapted for selectively preventing or allowing transmission of power from the second power source to the second electrically powered hub locker assembly.
[0033] The second hub and the second electrically powered hub locker assembly are preferably also mounted within the housing.
[0034] The second manually driven assembly is preferably driven by a key or a turn button.
[0035] In one form, the second electrically powered hub locker assembly is adapted for powered driving in a first direction to a first position and biased driving in a second direction opposite to the first direction to a second position, wherein the second electrically powered hub locker assembly remains at, or returns to, the second position when the second manually driven assembly is driven to prevent transmission of power to the second electrically powered hub locker assembly.
[0036] In another form, the second electrically powered hub locker assembly is adapted for powered driving in a first direction to a first position and powered driving in a second direction opposite to the first direction to a second position, wherein the second electrically powered hub locker assembly remains at the position it was occupying when the second manually driven assembly is driven to prevent transmission of power to the second electrically powered hub locker assembly.
[0037] The first manually driven assembly is preferably adapted for moving the first electrically powered hub locker assembly from:
a position preventing movement of the lock bolt in response to torque being applied to the first handle to a position allowing movement of the lock bolt in response to torque being applied to the first handle; or a position allowing movement of the lock bolt in response to torque being applied to the first handle to a position preventing movement of the lock bolt in response to torque being applied to the first handle.
[0040] The lock assembly preferably includes:
a second hub adapted to move the lock bolt in response to movement of a second handle, wherein the first manually driven assembly is preferably adapted for moving the first electrically powered hub locker assembly from:
a position preventing movement of the lock bolt in response to torque being applied to the second handle to a position allowing movement of the lock bolt in response to torque being applied to the second handle; or a position allowing movement of the lock bolt in response to torque being applied to the second handle to a position preventing movement of the lock bolt in response to torque being applied to the second handle.
[0045] The first electrically powered hub locker assembly preferably remains in the position it is moved to by the manual operation of the first manually driven assembly until subsequently acted upon by further manual operation of the first manually driven assembly.
[0046] The lock assembly preferably includes:
a second hub adapted to move the lock bolt in response to movement of a second handle; a second electrically powered hub locker assembly positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the second handle, and wherein the first manually driven assembly is adapted for moving the second electrically powered hub locker assembly from:
a position preventing movement of the lock bolt in response to torque being applied to the second handle to a position allowing movement of the lock bolt in response to torque being applied to the second handle; or a position allowing movement of the lock bolt in response to torque being applied to the second handle to a position preventing movement of the lock bolt in response to torque being applied to the second handle.
[0052] The second electrically powered hub locker assembly preferably remains in the position it is moved to by the manual operation of the first manually driven assembly until is subsequently acted upon by further manual operation of the first manually driven assembly.
[0053] The lock assembly preferably includes:
a second hub adapted to move the lock bolt in response to movement of a second handle; a second electrically powered hub locker assembly positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the second handle; and a second manually driven assembly adapted for moving the second electrically powered hub locker assembly from:
a position preventing movement of the lock bolt in response to torque being applied to the second handle to a position allowing movement of the lock bolt in response to torque being applied to the second handle; or a position allowing movement of the lock bolt in response to torque being applied to the second handle to a position preventing movement of the lock bolt in response to torque being applied to the second handle.
[0059] The second electrically powered hub locker assembly preferably remains in the position it is moved to by the manual operation of the second manually driven assembly until subsequently acted upon by further manual operation of the second manually driven assembly.
[0060] The first electrically powered hub locker assembly preferably includes a first driver in the form of a solenoid, a motor, a gravity driven device, a spring, an elastic band, a magnetic force, an electromagnetic force, an electrostatic force or any other force supplying or storage means.
[0061] The first driver is preferably an electrically powered pull type solenoid with a spring to biased return. Alternatively, the first driver is an electrically powered push type solenoid with a spring biased return. Further alternatively, the first driver is an electrically powered double keep type solenoid.
[0062] The second electrically powered hub locker assembly preferably includes a second driver in the form of a solenoid, a motor, a gravity driven device, a spring, an elastic band, a magnetic force, an electromagnetic force, an electrostatic force or any other force supplying or storage means.
[0063] The second driver is preferably an electrically powered pull type solenoid with a spring biased return. Alternatively, the second driver is an electrically powered push type solenoid with a spring biased return. Further alternatively, the second driver is an electrically powered double keep type solenoid.
[0064] The first manually driven assembly preferably includes a first engagement means settable in a first position engaging the first electrically powered hub locker assembly or in a second position not engaging the first electrically powered hub locker assembly, wherein movement of the first manually driven assembly whilst the first engagement means is in the first position causes movement in the first electrically powered hub locker assembly. The first engagement means is preferably slidable between the first position and the second position, most preferably in a direction parallel to the movement of the lock bolt.
[0065] The lock assembly preferably includes a front face with a first opening for providing access to the first engagement means. The first engagement means is preferably a first slidable block. The first slidable block preferably engages the first driven part in the first position and does not engage the first driven part in the second position.
[0066] The first manually driven assembly preferably includes a second engagement means settable in a first position engaging the second electrically powered hub locker assembly or in a second position not engaging the second electrically powered hub locker assembly, wherein movement of the first manually driven assembly whilst the second engagement means is in the first position causes movement in the second electrically powered hub locker assembly. The second engagement means is preferably slidable between the first position and the second position, most preferably in a direction parallel to the movement of the lock bolt. The lock assembly preferably includes a front face with a second opening for providing access to the second engagement means. The second engagement means is preferably a second slidable block. The second slidable block preferably engages the second driven part in the first position and does not engage the second driven part in the second position.
[0067] The second manually driven assembly preferably includes a second engagement means settable in a first position engaging the second electrically powered hub locker assembly or in a second position not engaging the second electrically powered hub locker assembly, wherein movement of the second manually driven assembly whilst the second engagement means is in the first position causes movement in the second electrically powered hub locker assembly. The second engagement means is preferably slidable between the first position and the second position, most preferably in a direction parallel to the movement of the lock bolt. The lock assembly preferably includes a front face with a second opening for providing access to the second engagement means. The second engagement means is preferably a second slidable block. The second slidable block preferably engages the second driven part in the first position and does not engage the second driven part in the second position.
[0068] In a second aspect, the present invention provides a lock assembly including:
a lock bolt movable between a latching position and an unlatching position; a first hub adapted to move the lock bolt in response to movement of a first handle; a first electrically powered hub locker assembly positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the first handle; and a first manually driven assembly adapted for moving the first electrically powered hub locker assembly from:
a position preventing movement of the lock bolt in response to torque being applied to the first handle to a position allowing movement of the lock bolt in response to torque being applied to the first handle; or a position allowing movement of the lock bolt in response to torque being applied to the first handle to a position preventing movement of the lock bolt in response to torque being applied to the first handle.
[0075] The lock assembly preferably includes a housing and the lock bolt, the first hub, the first electrically powered hub locker assembly and the first manually driven assembly are mounted within the housing.
[0076] The first manually driven assembly is preferably driven by a key or a turn button.
[0077] The first electrically powered hub locker assembly preferably remains in the position it is moved to by the manual operation of the first manually driven assembly until subsequently acted upon by further manual operation of the first manually driven assembly.
[0078] The lock assembly preferably includes
a second hub adapted to move the lock bolt in response to movement of a second handle, wherein the first electrically powered hub locker assembly is positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the second handle, and the first manually driven assembly is adapted for moving the first electrically powered hub locker assembly from:
a position preventing movement of the lock bolt in response to torque being applied to the second handle to a position allowing movement of the lock bolt in response to torque being applied to the second handle; or a position allowing movement of the lock bolt in response to torque being applied to the second handle to a position preventing movement of the lock bolt in response to torque being applied to the second handle.
[0084] In one form, the first electrically powered hub locker assembly is preferably adapted for powered driving in a first direction and biased driving in a second direction opposite to the first direction, wherein the first manually driven assembly is adapted for driving all or part of the first electrically powered driver assembly in the first direction or the second direction.
[0085] In another form, the first electrically powered hub locker assembly is preferably adapted for powered driving in a first direction and powered driving in a second direction opposite to the first direction, wherein the first manually driven assembly is adapted for driving all or part of the first electrically powered driver assembly in the first direction or the second direction.
[0086] The lock assembly preferably includes:
a second hub adapted to move the lock bolt in response to movement of a second handle; a second electrically powered hub locker assembly positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the second handle; and a second manually driven assembly adapted for moving the second electrically powered hub locker assembly from:
a position preventing movement of the lock bolt in response to torque being applied to the second handle to a position allowing movement of the lock bolt in response to torque being applied to the second handle; or a position allowing movement of the lock bolt in response to torque being applied to the second handle to a position preventing movement of the lock bolt in response to torque being applied to the second handle.
[0092] The second hub and the second electrically powered hub locker assembly are preferably also mounted within the housing.
[0093] The second manually driven assembly is preferably driven by a key or a turn button.
[0094] In one form, the second electrically powered hub locker assembly is preferably adapted for powered driving in a first direction and biased driving in a second direction opposite to the first direction, wherein the second manually driven assembly is adapted for driving all or part of the second electrically powered driver assembly in the first direction or the second direction.
[0095] In another form, the second electrically powered hub locker assembly is preferably adapted for powered driving in a first direction and powered driving in a second direction opposite to the first direction, wherein the second manually driven assembly is adapted to for driving all or part of the second electrically powered driver assembly in the first direction or the second direction.
[0096] The first electrically powered hub locker assembly preferably includes a first driver in the form of a solenoid, a motor, a gravity driven device, a spring, an elastic band, a magnetic force, an electromagnetic force, an electrostatic force or any other force supplying or storage means.
[0097] The first driver is preferably an electrically powered pull type solenoid with a spring biased return. Alternatively, the first driver is an electrically powered push type solenoid with a spring biased return. Further alternatively, the first driver is an electrically powered double keep type solenoid.
[0098] The second electrically powered hub locker assembly preferably includes a second driver in the form of a solenoid, a motor, a gravity driven device, a spring, an elastic band, a magnetic force, an electromagnetic force, an electrostatic force or any other force supplying or storage means.
[0099] The second driver is preferably an electrically powered pull type solenoid with a spring biased return. Alternatively, the second driver is an electrically powered push type solenoid with a spring biased return. Further alternatively, the second driver is an electrically powered double keep type solenoid.
[0100] The first manually driven assembly preferably includes a first engagement means settable in a first position engaging the first electrically powered hub locker assembly or in a second position not engaging the first electrically powered hub locker assembly, wherein movement of the first manually driven assembly whilst the first engagement means is in the first position causes movement in the first electrically powered hub locker assembly. The first engagement means is preferably slidable between the first position and the second position, most preferably in a direction parallel to the movement of the lock bolt. The lock assembly preferably includes a front face with a first opening for providing access to the first engagement means. The first engagement means is preferably a first slidable block. The first slidable block preferably engages the first driven part in the first position and does not engage the first driven part in the second position.
[0101] The first manually driven assembly preferably includes a first engagement means settable in a first position engaging the second electrically powered hub locker assembly or in a second position not engaging the second electrically powered hub locker assembly, wherein movement of the first manually driven assembly whilst the first engagement means is in the first position causes movement in the second electrically powered hub locker assembly. The first engagement means is preferably slidable between the first position and the second position, most preferably in a direction parallel to the movement of the lock bolt. The lock assembly preferably includes a front face with a first opening for providing access to the first engagement means. The first engagement means is preferably a first slidable block. The first slidable block preferably enagages the first driven part in the first position and does not engage the first driven part in the second position.
[0102] The second manually driven assembly preferably includes a first engagement means settable in a first position engaging the second electrically powered hub locker assembly or in a second position not engaging the second electrically powered hub locker assembly, wherein movement of the second manually driven assembly whilst the first engagement means is in the first position causes movement in the second electrically powered hub locker assembly. The first engagement means is preferably slidable between the first position and the second position, most preferably in a direction parallel to the movement of the lock bolt. The lock assembly preferably includes a front face with a first opening for providing access to the first engagement means. The first engagement means is preferably a first slidable block. The first slidable block preferably engages the first driven part in the first position and does not engage the first driven part in the second position.
[0103] The first electrically powered hub locker assembly is preferably connectable to a first power source and the first manually driven assembly is adapted for selectively preventing or allowing transmission of power from the first power source to the first electrically powered hub locker assembly. The lock assembly preferably includes a first controller between the first power source and the first electrically powered hub locker assembly, wherein the first manually driven assembly is adapted for altering the first controller from an energising configuration, allowing power to be transmitted from the power source to the first electrically powered hub locker assembly, to a de-energising configuration, preventing power from being transmitted from the power source to the first electrically powered hub locker assembly.
[0104] In one form, the lock assembly includes:
a second hub adapted to move the lock bolt in response to movement of a second handle, wherein the first electrically powered hub locker assembly is positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the second handle.
[0107] In another form, the lock assembly includes:
a second hub adapted to move the lock bolt in response to movement of a second handle; and a second electrically powered hub locker assembly positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the second handle, the second electrically powered hub locker assembly being connectable to the first power source, wherein the first manually driven assembly is adapted for selectively preventing or allowing transmission of power from the first power source to the second electrically powered hub locker assembly.
[0111] In a further form, the lock assembly includes:
a second hub adapted to move the lock bolt in response to movement of a second handle; a second electrically powered hub locker assembly positionable to selectively prevent or allow movement of the lock bolt in response to torque being applied to the second handle, the second electrically powered hub locker assembly being connectable to a second power source; and a second manually driven assembly adapted for selectively preventing or allowing transmission of power from the second power source to the second electrically powered hub locker assembly.
[0115] In one form, the first electrically powered hub locker assembly is adapted for powered driving in a first direction to a first position and biased driving in a second direction opposite to the first direction to a second position, wherein the first electrically powered hub locker assembly remains at, or returns to, the second position when the manually driven assembly is driven to prevent transmission of power to the first electrically powered hub locker assembly.
[0116] In another form, the first electrically powered hub locker assembly is adapted for powered driving in a first direction to a first position and powered driving in a second direction opposite to the first direction to a second position, wherein the first electrically powered hub locker assembly remains at the position it was occupying when the manually driven assembly is driven to prevent transmission of power to the first electrically powered hub locker assembly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0117] Preferred embodiments of the present invention will now be described, by way of an examples only, with reference to the accompanying drawings wherein:
[0118] FIG. 1 is a perspective view of a first embodiment of the lock assembly;
[0119] FIG. 2 is a perspective view of the lock assembly shown in FIG. 1 with the side cover removed, set to fail secure and not energised/locked;
[0120] FIG. 3 is a perspective view of the lock assembly shown in FIG. 2 , with the faceplate removed;
[0121] FIG. 4 shows the lock assembly of FIG. 2 with bolts retracted via key override;
[0122] FIG. 5 shows the lock assembly of FIG. 2 modified to operate a key operated manual override function, and the key operated manual override function activated to override the first locked electrically powered hub locker assembly, unlocking the first hub and allow rotation thereof;
[0123] FIG. 6 shows the lock assembly of FIG. 5 with the first hub rotated and the bolts retracted;
[0124] FIG. 7 shows the lock assembly of FIG. 2 with the key operated manual override function deactivated;
[0125] FIG. 8 shows the lock assembly of FIG. 7 set to fail safe and not energised/unlocked;
[0126] FIG. 9 shows the lock assembly of FIG. 8 with the key operated manual override function activated to override the unlocked first electrically powered hub locker assembly, locking the first hub and preventing rotation thereof;
[0127] FIG. 10 shows the lock assembly of FIG. 2 set to fail secure and energised/unlocked, with the key operated manual override function deactivated;
[0128] FIG. 11 is a perspective view a second embodiment of a lock assembly set to fail secure and energised/unlocked;
[0129] FIG. 12 shows the lock assembly shown in FIG. 11 with the key operated manual override function activated to override and deenergise the first locked electrically powered hub locker assembly, locking the first hub and prevent rotation thereof; and
[0130] FIG. 13 is a perspective view of a third embodiment of a lock assembly with the key operated manual override function activated to override the first unlocked electrically powered hub locker assembly, locking the first hub and prevent rotation thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0131] FIG. 1 shows an embodiment of an electrically controllable and electrically powered mortice lock assembly 20 . The lock assembly 20 includes a housing 22 with a side cover 24 and a face plate 26 . The lock assembly 20 is installed in a door with the housing 22 within a mortice void in the door and the face plate 26 adjacent to the non-hinged edge of the door, as is well understood by persons skilled in the art. A latch bolt 28 and an auxiliary bolt 30 pass through the faceplate 26 for engagement with a strike plate (not shown) in a door jamb, as is also well understood by persons skilled in the art.
[0132] The lock assembly 20 also includes an opening 32 that receives a key cylinder assembly 33 therein (as shown in FIG. 2 ). The key cylinder assembly is retained within the opening 32 with a key cylinder retaining pin (not shown), as is also well understood by persons skilled in the art. The key cylinder assembly 33 includes a key cylinder cam 33 a (as shown in FIG. 2 ). After the key cylinder assembly 33 has been inserted into the opening 32 , and the key cylinder retaining pin inserted into the key cylinder assembly 33 , the key cylinder retaining pin is prevented from releasing its engagement with the key cylinder assembly 33 by engagement of the faceplate 26 with the housing 22 .
[0133] For ease of description, the side of the lock assembly 20 shown in FIG. 1 will be referred to as the first side and the opposite side as the second side. The edge near the faceplate 26 will be referred to as the front and its opposite edge the rear. The edge near the opening 32 will be referred to as the bottom and its opposite edge the top.
[0134] The lock assembly 20 also includes a first hub 36 with a square cross section opening 38 therein, which is adapted to engage with a square cross section drive shaft (not shown) of a first external knob, lever or other handle (not shown).
[0135] FIG. 2 shows the lock assembly 20 with the side cover 24 of the housing 22 removed. The latch bolt 28 is connected to a latch bolt shaft 46 which is in turn connected to a latch bolt carriage 48 . The auxiliary bolt 30 is connected to an auxiliary bolt shaft 50 which is in turn connected to an auxiliary bolt carriage 52 . The latch bolt 28 and the auxiliary bolt 30 are biased toward a latching position, as shown in FIG. 2 , by a latch spring 54 and an auxiliary latch spring 56 respectively.
[0136] A carriage retraction arm 58 is pivotally mounted to the housing 22 by a shaft 60 and biased toward the position shown in FIG. 2 by a spring 62 . The arm 58 can be moved to retract the latch bolt 28 and the auxiliary bolt 30 under certain conditions, in response to movement of the first or second handles or the key cylinder assembly, as will be described in more detail below.
[0137] FIG. 2 also shows a first electrically powered hub locker assembly comprising a first electrically powered solenoid 64 which is connected to a first motion transfer means 66 which is in turn connected to a first hub locker 68 . The first solenoid 64 is of the pull type and also includes a first biasing spring 70 . The first motion transfer means 66 includes a tab 66 a, the function of which will be described in more detail below.
[0138] The lock assembly 20 also includes a second handle, a second hub and a second electrically powered hub locker assembly on its second side. The second electrically powered hub lock assembly comprises a second electrically powered solenoid which is connected to a second motion transfer means which is in turn connected to a second hub locker. The second electrically powered solenoid is also a pull type and includes a second biasing spring.
[0139] FIG. 2 also shows a first hub locking sensor 72 which is able to provide a signal indicative of the position of the first electrically powered hub locker assembly to allow remote signalling of the lock status of the first hub 36 to a remotely located controller or other internal control. A similar sensor is provided for the second electrically powered hub locker assembly. FIG. 2 also shows a latch bolt sensor 74 and an auxiliary bolt sensor 76 , which similarly signal the position of the latch bolt 28 and the auxiliary bolt 30 respectively. Other sensors (not shown) can also be added as desired to other mechanical facets of the lock assembly 20 , such as remotely signalling lock and/or door status or providing other internal control.
[0140] The construction and operation of the first and second electrically powered hub locker assemblies are identical and are described in the Applicant's Australian provisional patent application no. 2010903161 entitled “A lock assembly”, the relevant contents of which are incorporated herein by cross reference. Briefly, placing a screw 78 through opening 80 configures the movement of the hub locker 68 in response to the movement of its associated solenoid 64 in one direction and placing the screw 78 through opening 82 configures the movement of the hub locker 68 in response to the movement of its associated solenoid 64 in another, opposite, direction. As the first solenoid 64 is of the pull type, it retracts when energised and then relies on the first biasing spring 70 to extend it when not energised.
[0141] As shown in FIG. 2 , when the first motion transfer means 66 of the first electrically powered hub locker assembly is configured with the screw 78 in the opening 80 , and the associated solenoid 64 is not energised, the first hub locker 68 is driven by the solenoid spring 70 towards the first hub 36 to an extended position (as shown) engaging with and preventing rotation of (i.e. locking) the first hub 36 . When the solenoid 64 is energised, the first hub locker 68 is driven away from the first hub 36 to a retracted position allowing rotation of (i.e. unlocking) the first hub 36 . This is a fail secure setting.
[0142] When the first motion transfer means 66 is configured with the screw 78 in the opening 82 , and the solenoid 64 is not energised, the first hub locker 68 is driven by the solenoid spring 70 away from the first hub 36 to the retracted position allowing rotation of (i.e. unlocking) the first hub 36 . When the solenoid 64 is energised the first hub locker 68 is driven towards the first hub 36 to the advanced position engaging with and preventing rotation of (i.e. locking) the first hub 36 . This is a fail safe setting.
[0143] FIG. 3 shows the lock assembly 20 with the faceplate removed exposing a first adjustment port 84 and a second adjustment port 86 . The first adjustment port 84 is aligned with a first lockbar block 88 which has a first lockbar 90 therein. The first lockbar 90 can be positioned relative to the first lockbar block 88 in an extended position (e.g. FIG. 3 ) or a retracted position (e.g. FIG. 7 ). The first lockbar block 88 is carried on one end of a manual override slide 92 . The other end of the manual override slide 92 has a flange 94 which interacts with a lever 96 , which pivots about a shaft 98 . The lever 96 also interacts with key driven lever 100 , which pivots about a shaft 102 . A manual override sensor 103 is able to provide a signal indicative of the position of the manual override slide 92 . The second adjustment port 84 similarly provides across to a second lockbar within a second lockbar block. The above described components together form a manually driven assembly able to provide a key operated manual override function. As will be described in more detail below, the key operated manual override function is activated, with respect to the first side of the lock assembly 20 , by positioning the first lockbar 90 in the extended position and deactivated by positioning the first lockbar 90 in the retracted position. Similarly, the second adjustment port 86 is aligned with a second lockbar block which has a second lockbar therein. The second lockbar can also be positioned relative to the second lockbar block in an extended position or a retracted position. The second lockbar block is carried on the same end of the manual override slide 92 as the first lockbar block 90 . The key operated manual override function is activated, with respect to the second side of the lock assembly 20 , by positioning the second lockbar in the extended position and deactivated by positioning the second lockbar in the retracted position.
[0144] FIG. 3 also shows a key cylinder retraction bar 104 . The key cylinder retraction bar 104 has a first end 106 connected to the carriage retraction arm 58 and a second end with a depending part 108 .
[0145] As previously mentioned, FIG. 3 shows the lock assembly 20 set to fail secure and with the first solenoid 64 de-energised allowing the solenoid spring 70 to drive the first hub locker 68 into locking engagement with the first hub 36 , preventing rotation of same. As a result, the first hub 36 can not be rotated to withdraw the bolts 28 and 30 and the lock assembly 20 is locked from the first side. FIG. 3 also shows the manual override slide 92 positioned towards the upper edge of the lock assembly 20 (hereafter the upper position) and with the lock bar 90 in the extended position, but not pushing on the tab 66 a.
[0146] The key driven lever 100 is sitting rotated anti-clockwise so not pushing on lever 96 which in turn is not pushing on the flange 94 of the manual override slide 92 . This allows the manual override slide 92 to remain in the upper position shown.
[0147] Referring to FIG. 3 , the manual override slide 92 can be set to affect change only to the first, only to the second or to both of the first and second electrically powered hub locker assemblies of the lock assembly 20 , as will now be described. Pushing a key cylinder retaining pin, or other suitable tool, through the first adjustment port 84 pushes the lock bar 90 into the extended position, adjacent to the tab 66 a of the first motion transfer means 66 . As a result, downward movement of the manual override slide 92 towards the bottom edge (hereafter the lower position) of the lock assembly 20 will also pull the tab 66 a, and thus the remainder of the first motion transfer means 66 , downwards and cause movement in the first hub locker 68 similar to that of the first solenoid 64 being retracted. However, if the lock bar 90 is pulled to the retracted position (e.g. see FIG. 7 ) then the lock bar tip 90 will no longer be adjacent to the tab 66 a and movement of the manual override slide 92 will not affect the first motion transfer means 66 or the first hub locker 68 (see FIG. 7 ). The lock bar 90 is able to pulled to the retracted position by use of a hook tool (not shown) that is inserted through the adjustment port 84 , into the lockbar 90 , and then withdrawn towards the front of the lock assembly 20 .
[0148] FIG. 4 shows the lock assembly 20 of FIG. 2 after the depending part 108 of the key cylinder retraction bar 104 has been driven towards the bottom edge of the lock assembly 20 by rotation of the key cylinder cam 33 a of the key cylinder assembly 33 by a correct key. The resulting movement in the key cylinder retraction bar 104 pivots the carriage retraction arm 58 to withdraw the lock bolt 28 and the auxiliary bolt 30 . It will be appreciated that this action, known as key override unlatching, withdraws the bolts 28 and 30 for door opening but, importantly, it does not unlock the lock assembly 20 . Accordingly, as soon as torque is removed from the key used to rotate the key cylinder cam 33 a, the springs 54 and 56 extend the bolts 28 and 30 respectively and return the lock to assembly 20 to the locked configuration shown in FIG. 2 .
[0149] FIG. 5 shows the lock assembly 20 of FIG. 2 modified to operate a key operated manual override function by the addition of a revised key cylinder cam 33 a that has an extension 33 b thereon. The key operated manual override function is shown activated, by the first lockbar block 90 being in the extended position. FIG. 5 shows the key cylinder cam 33 a being rotated by a correct key to a position which causes the key driven lever 100 to pivot clockwise which in turn causes the lever 96 to pivot anti-clockwise and pull the manual override slide 92 downwards toward the bottom edge of the lock assembly 20 into the lower position. The manual override slide 92 carries the lockbar block 88 and lockbar 90 downwards allowing the lockbar 90 to pull the tab 66 a and thus the first motion transfer means 66 downwards. This in turn moves the first hub locker 68 to the retracted position. As a result, the first hub 36 is free to rotate and this rotation of the first hub 36 will retract the bolts 28 and 30 (as shown in FIG. 6 ) and the first side of the lock assembly 20 is unlocked. The manual override slide 92 will remain in the lower position shown, and thus keep the first side of the lock assembly 20 unlocked, until it is moved again by the correct key. The lock assembly 20 can be relocked by the use of the correct key (see FIG. 7 ) to rotate the key cylinder cam 33 a in a clockwise direction to pivot the key driven lever 100 in an anti-clockwise direction and reverse the previously described movements. Once again, the manual override slide 92 will then remain in the upper position until further acted upon by the correct key.
[0150] FIG. 6 shows the lock assembly of FIG. 5 after rotation of the first hub 36 has caused the carriage retraction arm 58 to withdraw the bolts 28 and 30 .
[0151] FIG. 7 shows the lock assembly 20 with the lockbar 90 pulled into the retracted position so that the lockbar 90 is no longer adjacent to the tab 66 a. As a result, the key operated manual override function is deactivated and movement of the manual override slide 92 will have no affect on the first motion transfer means 66 or the first hub locker 68 .
[0152] FIG. 8 shows the lock assembly 20 set to fail safe by the screw 78 being inserted within the opening 82 . The solenoid 64 is shown not energised and the first hub locker 68 is thus shown being driven by the first solenoid spring 70 to the retracted position, allowing rotation of the first hub 36 . In other words, the first side of the lock assembly 20 is to unlocked. The key operated manual override function is activated by the lockbar 90 being pushed into the extended position where it may engage the tab 66 a of the first motion transfer means 66 .
[0153] FIG. 9 shows the lock assembly 20 of FIG. 8 after the key operated manual override function has been used to manually lock the first side of the lock assembly 20 . As shown, the key cylinder cam 33 a has been pivoted by the correct key such that the extension 33 a causes the key driven lever 100 to pivot in a clockwise direction causing the lever 96 to pivot in an anti-clockwise direction and in turn cause the manual override slide 92 to be driven downwards to the lower position. During this movement, the locking bar 90 abouts the tab 66 a and causes the first motion transfer means 66 to drive the first hub locker 68 from the retracted position to the extended position, preventing rotation of the first hub 36 . As a result, the first side of the lock assembly 20 is now locked. Once again, the manual override slide 92 will remain in the lower position, and thus keeps the first side of the lock assembly 20 locked, until it is moved again by a correct key.
[0154] The first side of the lock assembly 20 can be unlocked by use of a correct key to rotate the key cylinder cam 33 a clockwise and drive the key driven lever 100 anti-clockwise and the lever 96 clockwise. This movement reverses the previous actions. Once again the manual override slide 92 will remain in the upper position until further acted upon by the correct key.
[0155] The position of the manual overrides slide 92 shown also activates the manual override sensor 103 which can provide a signal to cause further action. For example, the signal can be used to cause the removal of any external electrical drive, control or power signal from operating one or more of the first and second solenoids or can provide a signal notifying a control centre that the manual key override function has been used.
[0156] FIG. 10 shows the lock assembly 20 with the electrically operated locking components set to fail secure, as per FIG. 2 and FIG. 3 , and with the first solenoid 64 energised and retracted so that the first side of the lock assembly 20 is unlocked. As shown, the manual override slide 92 is not affecting the lock assembly 20 . If an external party gains access to the lock assembly's control system they may arrange for the lock assembly 20 to be left unlocked in order to gain unauthorised entry. In this situation, it is advantageous to be able to manually override this unlocked state and so secure the door. However, the manual override slide 92 as described so far cannot make any change to the state of the lock assembly 20 because the tab 66 a and thus the first motion transfer means 66 is already in the position that it would be driven to by downwards movement of the manual override slider 92 .
[0157] FIG. 11 shows a second embodiment of a lock assembly 20 ′ able to address the above situation by allowing for external electric control of the solenoids to be removed whilst leaving the hub locker 68 where the fail safe or fail secure configuration of the lock has positioned it. As a result, the lock assembly 20 ′ can be locked or unlocked using a key. In order to do so, the lock assembly 20 ′ includes a sensor 110 adapted to interact with an extended form of the key driven lever 100 . FIG. 11 shows the lock assembly 20 ′ after the key cylinder cam 33 a has been rotated by the correct key to pivot the key driven lever 100 anti-clockwise. In this position, the sensor 110 sends a signal that the key operated manual override function is not in use.
[0158] FIG. 12 shows the lock assembly FIG. 11 after the key cylinder cam 33 a has been pivoted rotated by the correct key to pivot the key driven lever 100 clockwise. As previously described, the resulting movement in the manual override slide 92 has no influence on the first motion transfer means 66 or the first hub locker 68 as the locking bar 90 is in the withdrawn position. However, the triggering of the switch 110 by the movement of the key driven lever 100 sends a signal to the controller that the power supply to the first solenoid 64 should be removed. When the lock assembly 20 is configured as fail secure as shown, removing power from the solenoid 64 allows the spring 70 to drive the first motion transfer means 66 to cause the first hub locker 68 to engage with, and prevent rotation of, the first hub 36 . This action locks the first side of the lock assembly 20 ′.
[0159] If the lock assembly 20 was configured as fail safe, the reverse would occur and the spring 70 would drive the first hub locker 68 from the engaged position to the withdrawn position, thereby unlocking the first side of the lock assembly 20 ′. Accordingly, the triggering of the switch 110 allows the lock state of the lock assembly 20 ′ to be (manually) reversed.
[0160] FIG. 13 shows a third embodiment of a lock assembly 20 ″ in which it is possible to remove external electric control to the first and/or second solenoids and also move the first hub locker 68 from the position it is placed in by the fail safe or fail secure setting of the lock assembly. Accordingly, the correct key can be used to do one of locking or unlocking.
[0161] FIG. 13 shows the lock assembly 20 ″ after starting in a condition similar to that shown in FIG. 8 (i.e. set to fail safe, the solenoid 64 not energised and thus unlocked) but that has now been acted upon by the key operated manual override function. When the correct key is used to pivot the key cylinder cam 33 a and thus pivot the key driven lever 100 in a clockwise direction, the sensor 110 triggers the removal of external control from the first solenoid 64 . The lockbar 90 is sitting in the extended position. As the manual override slide 92 is drawn downwards, the engagement between the lockbar 90 and the tab 66 a will cause the first motion transfer mechanism 66 to drive the first hub locker 68 into the extended position preventing rotation of the first hub 36 . As a result, the lock assembly 20 ″ is locked from the first side.
[0162] If the lock assembly 20 ″ had instead been set to a fail secure, then the same movement of the manual override slide 92 would have instead unlocked the first hub 36 . Accordingly, the sensor 110 is able to be used to disable remote electrical locking/unlocking, allowing the key operated manual override function to advantageously be used to independently invert the lock state as desired.
[0163] The above described lock assemblies have electrically powered hub locker assemblies (ie. locking/unlocking mechanisms) and also include a manually driven assembly (ie. key operated manual override function or mechanical locking/unlocking mechanism). The mechanical mechanism can advantageously be used to change the state of the lock assembly or to prevent the electrical control system from changing the lock assembly's lock/unlock state.
[0164] The key operated manual override function can be used in three ways. Firstly, the function can be used to only block or remove a remote signal from influencing the electrically powered hub locker assemblies (eg. solenoids/motors etc) so that: 1) if there is no remote signal at the time of manual overriding the state of the lock assembly does not change; 2) if there is a remote signal at the time of manual overriding and the actuator has a biased position then the solenoid will revert to the biased position; or 3) if there is a remote signal at the time of manual overriding and the actuator has two stable positions (ie. no biased position) then the state of the lock assembly does not change.
[0165] Alternatively, the function can physically change the position of the mechanical components that the electrically powered hub locker assemblies use to lock or unlock the lock regardless of a signal being applied or not being applied to the electrically powered hub locker assemblies.
[0166] As a result, the above described lock assemblies, when set to operate as fail safe, are still able to be used to lock the door in the absence of power. This obviates the need for a security guard or a separate manual lock to secure the door until power is returned. Further, when set to operate as fail secure, they are able to be used to unlock the door in the absence of power. This allows the normal operation of a door to continue in the absence of power.
[0167] The lock assembly embodiments described above are advantageous in many applications such as:
during the fitting out of a building when the door control/monitoring electrics are not yet installed or fully operational. If the lock assembly is set to fail safe (ie. unlocked when no power) then the manual override function can be used to lock the door after hours. If the lock is set to fail secure (ie. locked when no power) then the manual override system can be used to unlock the door during working hours; changing the lock assembly's status at any time when the power supply is interrupted, so the lock can still perform lock/unlock functions and keep a building's activities going until the electrical systems are restored; during normal powered operation, giving a manual override option;
[0171] providing a signal from within the lock assembly and sending it to the building monitoring system to show the manual key override function has been used during normal powered operation;
the remote electrical locking/unlocking of the lock assembly by an external signal powering the solenoid can be disabled internally in the lock by use of the key. Thereafter the electrically powered hub locker assemblies are de-energised and adopt whatever position that the fail safe/fail secure settings encourage. At this time the override mechanism can either leave the electrically powered hub locker assemblies in this biased position or move it to its other position; choosing whether or not the manual override function moves the hub locker or not at installation or at any time later without removing the lock from the door and whether the override mechanism removes external control from the solenoid or not is also switch selectable before installation or at any time after without removing the lock from the door; and with the addition of an additional switch on the front edge of the lock assembly that is accessible once the door is open, the remote electrical locking/unlocking of the lock by an external signal can be disabled for as long as manual key control is desired without removing the lock from the door.
[0175] Although the invention has been described with reference to preferred embodiments, it will be appreciated by persons skilled in the art that the invention can be embodied in many other forms. For example, the embodiments of lock assembly described above use independent first and second electrically powered hub locker assemblies for each side of the lock and a single manually driven assembly (ie. key operated manual override function) which can interact with each of the first and second electrically powered hub locker assemblies. In other embodiments (not shown) both of the hubs can be locked/unlocked by a single electrically powered hub locker assembly and/or independent first and second manually driven assemblies (ie. key operated manual override functions). In a further embodiment (not shown), the first and second adjustment ports are positioned s on the sides or the top, bottom or rear edges of the lock assembly, so as not to be accessible via removal of the face plate. | 4y
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This application is a continuation of co-pending PCT Application PCT/US01/04336, filed on Feb. 9, 2001, and is a continuation-in-part of U.S. patent application Ser. No. 09/500,626, filed on Feb. 9, 2000, now U.S. Pat. No. 6,472,671. The disclosure of the above-mentioned applications is considered part of, and is incorporated by reference in the disclosure of this application.
TECHNICAL FIELD
This invention relates to microscopy and more particularly to calibrating a position of a sample with respect to optical elements of a microscope and/or to calibrating fluorescence detection in microscopes.
BACKGROUND
Testing or calibration targets are employed to evaluate system performance of conventional microscopes. These are used to establish a baseline between different microscope systems and to characterize image quality in terms of its conventional components: resolution, contrast, depth of field and distortion. Common offerings for conventional microscopy are the USAF Field Resolution target, the USAF Contrast Resolution Target, the Star Target, the Ronchi Ruling Targets, Modulation Transfer Function Targets, Depth of Field Targets, and Distortion and Aberration Targets. There are others.
The targets are typically printed or vapor deposited patterns on plastic or glass substrates. The optical features on the target are preferably finer than the resolution of the optical system being tested. While it is desirable that the reference features have dimensions or parameters an order of magnitude smaller than those of the specimens to be examined by the microscope, practitioners have had to accept reference dimensions or parameters only 4 or 5 times smaller than those of the specimens to be examined.
Fluorescent microscopy of specimens is different from and more demanding than conventional microscopy because it is based on relatively low-level fluorescent emissions excited by illumination of the specimen, typically employing confocal arrangements for detecting the relatively weak signal through a pin hole or the like. An example is the detection of fluorescence from dried liquid spots containing possibly fluorescing biological material, the dried spots being essentially at the focal plane of the instrument (dried spot thickness less than a few microns). Another example is fluorescence from a biological microarray such as from a GeneChip® biological array product, as produced by Affymetrix, Inc., in which the fluorescing material is of relatively insignificant thickness.
For testing or calibration targets for fluorescence microscopy, besides the numerous conventional components of image quality, there is the requirement of testing the optical efficiency of the system in respect of fluorescence emission. This introduces significant complications, as fluorescence involves an excited photochemical effect, to produce a voltage or signal level in the detector, that introduces signal to noise ratio considerations that interact with measurements of the various optical components involved in the calibration. In general the signal to noise ratio must be at least 3 to 1 to obtain satisfactory operation.
It has been an unsolved problem, to find a calibration target that adequately simulates the fluorescent activity which it is desired to quantify over a broad range of instruments and conditions of use. It is wished to simulate fluorescing specimens that generally lie within the depth of field of the microscope, and in the case of micro dots of biological material, lie essentially at a plane, e.g. in a depth of only a few microns or even substantially less. As the dimensions of individual specimens to be imaged become increasingly smaller as microarray technology advances, the significance of not having a suitable calibration tool has become increasingly severe.
The difficulties for fluorescent microscopy is that, without the desired degree of calibration, it becomes difficult to compare the results obtained in biological or other research performed with different instruments, thus creating serious difficulties in comparing and coordinating the results of different laboratories, whether the laboratories be at different institutions, or separate laboratory facilities within the same institution. Likewise, even with a given instrument, the uncertainties of calibration can introduce errors in the measurement of important actions such as proportional expression, etc. In particular the lack of good reference and calibration is felt at the forefront of research where results are so new and there has been insufficient time or experience to generate reliable standards. The development of true quantified fluorescence microscopy can fulfill this need. On the other hand, the availability of a strong calibration tool will likely to open the possibilities of inexpensive and reliable fluoresence instrumentation and procedures for the clinical setting for diagnosis and treatment. Existing calibration tools for conventional microscopy do not satisfactorily fill the needs of fluorescence microscopy. A number of special techniques have been offered.
One technique, offered by Max Levy Reprographics, uses a layer of organic fluorescent material e.g. of 3 micron thickness, having fluorescence emission across a broad wavelength spectrum, deposited on a non-fluorescent glass substrate such as synthetic quartz. A suitable pattern is then etched away into the fluorescent material, so that the critical edges of the reference are defined by the exposed edges of the fluorescing material. One shortcoming of this technology is that the minimum thickness of the fluorescent material that can be deposited is of the order of 3 micron and, with such thickness, the edges of the pattern do not etch squarely. The finest reference details that can be formed in this material are believed to be approximately 4 micron width lines, spaced apart 8 microns on center. This is unsatisfactory for calibration with respect to instruments employing conventional 5 micron spot size and is an order of magnitude greater than required to evaluate optical spots that are ½ micron in diameter, achievable with a microscope having an 0.7 NA objective in air, or ¼ micron diameter achievable with a 1.4 NA, oil immersion objective. The relatively large thickness of the fluorescent layer poses problems of edge definition, particularly because the fluorescent rays emit at acute angles to the surface and can be blocked by the edges of the material, or on the other hand, the edges themselves fluoresce, to produce confusion.
Another technique for testing a fluorescent microscope uses as a substrate a fluorescent glass on which is deposited a very thin metal layer e.g. a few hundred Angstrom thick. Preferably a nickel layer is employed. A suitable pattern is subsequently etched in the metal to create fine features, as small as ½ micron dimension. Whereas this technique does not have the foregoing edge problem, I have realized that there are shortcomings to this approach, owing to the fact that the glass constitutes a significant fluorescing volume, i.e., a substantial thickness, 1 millimeter, far exceeding the depth of field (Notably, for a spot size of 5 or 1 ½ micron, the depth of field is typically about 50 micron and 4.5 micron, respectively, and progressively less for smaller spot sizes). The fluorescent radiation emitted from this volume causes focus to be difficult to define accurately and hence is an unsatisfactory standard for many purposes.
Accordingly, there is a need for calibration tools, calibration apparatuses, methods and tools used in microscopy.
SUMMARY OF THE INVENTION
The present invention relates to calibration apparatuses, methods and tools used in microscopy. The present invention may separately be used for calibrating a location of a sample with respect to optical elements and for calibrating fluorescence detection in microscopes.
According to one aspect, a calibration tool for fluorescent microscopy includes a support, a solid surface layer including a fluorescent material, and a thin opaque mask of non-fluorescent material defining reference feature openings having selected dimensions exposing portions of the surface layer.
Preferably, a first type of the calibration tool may include an adhesion promoter facilitating contact between the surface of the support and the solid surface layer including the fluorescent material, which is in contact with the thin opaque mask. Alternatively, a second type of the calibration tool may include the thin opaque mask fabricated (with or without an adhesion promoter) onto the support, and the solid surface layer including the fluorescent material located on the thin opaque mask.
Preferred embodiments of this aspect may include one or more of the following: The thin opaque mask is fabricated onto the support using an adhesion promoter. The support is flat and rigid. The support includes fused quartz. The surface layer is opaque. The mask comprises a thin metal film. The support forms an optical window of a cassette. Several suitable types of cassettes are described in U.S. Pat. No. 6,140,044, which is incorporated by refrence.
The fluorophores are excitable by optical radiation passing through the support and/or through the openings in the mask. The fluorophores are excited by optical radiation passing through the support and through the openings in the mask and the support absorbs excited fluorescent radiation. The solid surface layer provides a broadband fluorescence emitter. The solid surface layer provides a fluorescence emitter active at at least two wavelengths and having emission, characteristics similar to Cy3 and Cy5 fluorescent dies. The solid surface layer provides a fluorescence emitter having effective fluorescent emittance that can produce a full scale response for microscope calibration. The solid surface layer including the fluorescent material has a thickness in the range of about 2 micron to about 250 micron. The solid surface layer is polyimide.
The thin opaque mask has a thickness in the range of about 10 nm to about 10 micron. The thin opaque mask has a thickness in the range of about 10 nm to about 100 nm.
According to another aspect, a process for producing a calibration tool for fluorescent microscopy includes providing a support, providing a solid surface layer including a fluorescent material, and fabricating a thin opaque mask of non-fluorescent material defining reference feature openings having selected dimensions exposing portions of the surface layer.
Preferred embodiments of this aspect may include one or more of the following: The solid surface layer may be deposited onto the support the solid surface layer having the fluorescent material. This may include depositing an adhesion promoting layer onto the support for forming the solid surface layer including the fluorescent material. The deposition includes delivering vapor forming the solid surface layer including the fluorescent material, such as evaporating or sputtering. The depositing includes spin coating to form the solid surface layer including the fluorescent material.
The fabrication of the thin opaque mask includes depositing onto the support the non-fluorescent material and patterning the non-fluorescent material to form the reference feature openings. Then, the solid surface layer including the fluorescent material is deposited onto the thin opaque mask.
The support may be fused quartz. The thin opaque mask may include metal. The support may be used as an optical window for a cassette used in examination of biological material.
The solid surface layer provides a broadband fluorescence emitter.
The solid surface layer provides a fluorescence emitter active at at least two wavelengths and having emission characteristics similar to Cy3 and Cy5 fluorescent dyes.
According to another aspect, a method of calibrating a microscope includes providing a microscope, employing the above-described calibration tool, bringing in focus an excitation beam emitted from an objective of the microscope by examining the reference feature opening, and calibrating detection intensity of the microscope. The bringing in focus may include adjusting a position of a sample table wherein the calibration tool is located. The microscope may be an on-axis flying objective microscope. The microscope has a micro-lens objective carried upon an oscillating rotary arm.
The calibration tool is suitable for use with a confocal microscope having a restricted depth of field and the solid surface layer that comprises fluorophores has an effective depth of less than the depth of field of the confocal microscope, preferably the surface layer having an effective fluorescent emittance that can produce a full scale response of the microscope.
According to yet another aspect, a method of quantified fluorescence microscopy includes providing a fluorescence detecting microscope, employing a calibration tool as described above to calibrate the microscope, and performing fluorescence microscopy of specimens employing the calibrated microscope. Preferably the microscope is an on-axis flying objective microscope, and most preferably, the microscope has a micro objective lens carried upon a rapidly oscillating rotary arm.
In a preferred embodiment, a fluorescent calibration tool is built with a suitably fluorescent solid surface layer of constant thickness that is opaque, made of organic material or inorganic material, carried on a suitable support. For materials that are not naturally opaque, dyes or pigments are added. A very thin metal layer is subsequently deposited on the opaque fluorescent material and covered with a layer of photo-resist. An appropriate pattern is then imaged on the photo-resist and chemically etched. The resulting fluorescent pattern showing through the etched openings has extremely fine features because the metal layer is as little as a fraction of a micron thick, preferably about 100 to 300 Angstrom thick. The pattern-creating process can be identical to the process used to create integrated circuits. Presently that technology enables the formation of features as narrow as 0.2 micron width lines separated by spaces of the same dimension.
In the calibration tool, the fluorescence is caused to be a surface emission phenomenon, which permits reliable focusing and fluorescence calibration, that can be used as a standard, and enable all instruments to be set to the same standard. Preferably, the calibration tool uses a very stable fluorescing material, that is insensitive to photobleaching.
An important fluorescing material with a broad band of fluorescent response, is a selected polyimide such as Kapton™ available in liquid form and used for spin coating substrates and creating sheets with 1 to 10 micron thickness. A suitable product is available under the trade designation WE-IIII or PI-IIII from H. D. MicroSystems, Wilmington, Del. This material is a polyimide which has as a backbone a high molecular weight polyimic acid precursor comprised of specific aromatic decanydride and an aromatic diamine.
The fluorescing material may preferably be another polyimide product, Probonide 116A, available from Arch Chemicals of Portsmouth, N.H. This material exhibits broad band fluorescence of approximately ¼ the intensity of the H. D. MicroSystems product, that can be satisfactorily used. Alternatively, fluorescing polyimide material is one that is provided to the semiconductor industry as a self-priming, non-photosensitive polyimic acid formulation which becomes a fully stable polyimide coating after thermal curing.
Another material for the surface layer, suitable for a specific wavelength of interest, is an extremely thin layer of fluorescent glass deposited e.g. by evaporation or by a sol-gel process on a non-fluorescent support. In the case of a sol gel, large molecules of a glassy type of material are suspended, with selected fluorophores in a water or alcohol carrier, and applied as a film coating to a support. It is baked at a relatively low temperature to form a thin glassy fluorescent film. In these and other cases, fluorescing dyes for specific wavelengths are incorporated in a suitable non-fluorescing and preferably opaque binder, applied as a thin, uniform thickness coating. Examples of fluorescing dyes are Cy3, Cy5, and fluorescene.
In all events, the substance of the surface layer must be selected to produce sufficient fluorescence to be detected in the way that is normal to use in, operating the instruments for examining fluorescent specimens. The specific selection of a fluorescing reference material is dependent upon numerous parameters such as the response of the instrument, the selected wavelength, the size of the features to be examined and the spot size of the excitation beam. In the case of the commercial instrument as described as an example in the accompanying appendix, the fluorescent material must produce of the order of one million times the radiation detected at the detector. The polyimide materials described above provide a great benefit over others in being broad band and hence suitable as a single reference that is useful over a range of selected wavelengths at which important experiments are performed.
Some fluorescent microscopy applications demand that the material under inspection be located behind a transparent protective window, typically made of non-fluorescent optical glass such as synthetic quartz. In such cases the alignment tool preferably duplicates the application and the metalized target is first created on the glass and the fluorescent media is applied as a coating covering the metalization as well as the glass, or is provided as a planar coating on a second optically flat member which is then mounted face-to-face with the metal layer on the first optically flat member.
Importantly, in many cases, the effective fluorophores for producing photons that reach the detector lie substantially only in a surface layer. (As used herein, the term, “effective fluorophores” is meant to include substantially all of those fluorophores which are effective to produce meaningful fluorescent radiation from the face of the surface layer that can reach the detector of a microscope, and does not refer to fluorophores which are either out of the range of excitation radiation of the microscope due to the opacity of the matrix, or, though within the range of effective excitation radiation, do not produce fluorescent radiation that reaches the detector of the microscope, due, e.g., to absorption by the opaque matrix material.) The surface fluorophores approximate what occurs when dots of biological specimen material only a fraction of a micron thick produce fluorescence in response to an incident excitation beam.
In the persent calibration tool, limitation of fluorescence to the surface layer suitable for a given application may accomplished by one or a combination of techniques. In one case, the binder material for forming the solid matrix in which the calibration fluorophores are contained, is made essentially opaque at the excitation or detection wavelength or both, such that a large fraction, e.g. 80% or more, preferably as much as 99% of the detected fluorescing radiation, emanates from a surface layer of depth, Δ t , that is only of the order of the thickness of the specimen to be inspected, and within the depth of field of the instrument. In another case, the micro thickness of a layer in which the fluorophores are confined is controlled to a high degree of uniformity, the layer sitting on an opaque support devoid of fluorophores, such that even if some fluorescence occurs from a depth beyond the preferred bound, the resulting fraction of luminescence outside of the bound is uniform across the tool because of the uniformity of coating thickness, and hence is not effective to significantly disturb the calibration.
In another case, the fluorophores are introduced to a surface layer after preforming the surface layer, e.g., by diffusion, spray or implantation techniques that confine the fluorophores essentially to the surface that is to be exposed by openings in the pattern. Thus, in the calibration tool, an effective solid fluorescent surface layer is provided that can serve as a proxy for the specimen to be examined.
The thickness of the thin metal layer or other material forming the reference pattern also matters, because many rays of the detected fluorescence form an angle as great as 45 degrees with the surface being examined, and can be blocked by the edge walls of the pattern elements, if the elements are too thick, to impair the resolution of detection of the pattern edge. The finer the features to be inspected, the finer must be the calibration of the instrument, hence the more critical becomes the thickness of the pattern elements, i.e., the reference lines, circles, etc., included in the thin opaque mask.
An important aspect is the fluorescent wavelength produced by the fluorescing surface layer. Preferably, the calibration tool is made employing a broad band fluorescent material and thus is useful with various lasers and wavelengths used in a microscopes and with different types of fluorophores used in various lines of scientific or industrial inquiry. In one example, a polyimide material is selected which has effective fluorescence for use as a reference at wavelengths from 473 nm to 850 nm, or more preferably from 450 nm to 800 nm, covering essentially the entire visible spectrum. (The visible spectrum is important, since a great deal of historical biological data has been generated in that region, and is available for reference and comparison as research proceeds.) However, fluorophores in the near infrared and ultraviolet may be employed, given suitable circumstances with respect to the biology and the available sources of illumination and detection.
According to another aspect, the calibration tool is used in combination with a flying objective, on-axis scanner, to achieve highly reproducible quantified fluorescence microscopy. While microscopes with any means of moving the lens preferably a micro lens, is included, significant further advantages are obtainable by employing an oscillating rotary arm to transport the micro lens over the specimen or calibration tool. The calibration of fluorescence detection microscopes, to the calibration of on-axis, wide field of view scanning fluorescence microscopes, and ultimately to quantified fluorescent microscopy having application from the forefront of genomic research and drug discovery to clinical use. The invention has particular application to the accurate reading of biochips and micro arrays.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of an alignment tool used in microscopy.
FIG. 2 is a cross-section of the tool taken through certain alignment features along lines 2 — 2 of FIG. 1 .
FIG. 3 is a diagram depicting the fabrication of the alignment tool of FIG. 1 .
FIG. 4 shows one embodiment of the allignment tool used with a microscope.
FIG. 4A shows an alternative embodiment of the allignment tool used with a microscope.
FIG. 5 illustrates diagramatically another method for fabrication an alignment tool, while FIG. 5 a shows the resulting tool.
FIG. 5 b illustrates diagramatically another method for fabrication an alignment tool, while FIGS. 5 c and 5 d are schematic cross-sectional views of the tool fabrication.
FIG. 6 is a view of an alternative to the construction of the tool shown in FIG. 5B .
FIG. 7 illustrates the use of the tool shown in FIGS. 5B or 6 .
FIGS. 8 and 8A illustrate diagrammatically a wide-angle fluorescent scanning microscope employing a flying micro objective lens on a rapidly rotating, oscillating arm.
FIG. 9 is a perspective representation of an oscillating arm of the scanning microscope shown in FIG. 8 employing an alignment tool.
FIG. 10 is a diagramatic plan view of the oscillating arm shown in FIG. 9 used for scanning a microarray of biological material on a glass slide or biochip following the calibration of the scanning microscope shown in FIG. 9 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2 , the alignment tool 2 a comprises a generally planar rigid member carrying on its face a detailed pattern of optical features suitable for calibration of the instrument. The rigid member is typically of the same dimensions as the microscope slide, microarray chip or other object to be examined, to fit in the same position on the instrument. The optical features of the alignment tool include lines and circular dots of various dimensions to emulate the various sizes of dots and linear features of biological or other material to be examined. The finest features have dimensions of the order of 1 micron or less to suitably calibrate for detection of features of a few micron dimensions or less.
The calibration tool shown in FIGS. 1 and 2 includes regions T- 1 , T- 2 , T- 3 , T- 4 , and T- 5 . Region T- 1 includes a set of “barcode” lines having thickness 2 micron, 4 micron, 6 micron, 8 micron, 10 micron, and 12 micron, separated by twice their size. Region T- 2 include a long 5 micron and 10 micron line across. Region T- 3 includes a solid layer of the fluorescing material. Region T- 4 includes three arrays of circular features having diameters from 300 micron to 25 micron, and squares having sizes from 300 micron to 25 micron. Region T- 5 is a solid metallic area.
Referring to FIG. 3 , in one preferred embodiment the first step in manufacture of the calibration tool is to provide a rigid support plate having effective fluorophores confined to a solid surface layer 4 of only an incremental thickness, see FIG. 2 . Typically this depth, delta t, is negligible such that fluorescent emission occurs essentially as a surface phenomenon. Upon this layer, step two, a nickel or other suitable very thin and opaque metal film is applied that is etchable to form a reference pattern. Sputter coating, vacuum metal deposition or other known techniques may be employed. A photo-resist is then applied in general to the metal layer, the photoresist on the tool preform is exposed through a precision mask defining the alignment features and then the surface is chemically etched to form the resulting reference pattern. The resultant tool is used to calibrate fluorescence measurements as well as the conventional image components of fluorescent microscopes.
Referring to FIG. 4 , an oscillating arm 19 , rotating about axis A, carries an on-axis micro objective lens 18 for on-axis scanning over the alignment tool 2 A which is positioned in the place ordinarily occupied by specimens to be examined. Mirrors 15 and 17 are effective to introduce excitation light from a stationary laser source, along axis of rotation A, thence out along the arm to lens 18 , thence to the specimen (or in this case, to the calibration tool). Light reaching the surface layer 4 of the tool excites effective fluorophores, which emanate in all directions at a different wavelength. A significant feature is that this radiation is captured by micro lens 18 (whose axis is always perpendicular to the object plane), and directed back through the optical path and through a restriction such as a pin hole 103 , to detector D, 95 , typically a photo multiplier tube (PMT).
In the case of FIG. 4 , the surface layer 4 is a separately applied layer of uniform minimum thickness applied to a solid, optically flat, opaque support plate. Preferably surface layer 4 is also opaque such that excited light does not substantially penetrate even the surface layer; but even if it does penetrate to a degree, because of the great uniformity of the layer, and the non-emitting character of its support, any incidental fluorescence from below the surface layerΔ t is uniform throughout, hence its disturbing effect can in many instances be tolerated. Depending upon the particular instrument and application, in some cases, in which the solid surface layer is extremely thin and sufficiently uniform in thickness and distribution of fluorophore, the surface layer need not be opaque and will still function appropriately to produce essentially only surface emissions.
The alternative processes of FIGS. 5 and 5 b are self explanatory, both producing calibration tools which, in use, are illuminated by light passing through the transparent pattern support. The tool of FIG. 5A is produced by the steps of FIG. 5 while the tools of FIGS. 5D and 6 are produced employing the steps of FIG. 5B . The tools of FIGS. 5D and 6 differ from each other in the same respect that tools of FIGS. 4 and 4A differ, described above.
The resultant tools are effective to enable standardization of wide field of view fluorescent scanning microscopes such as the microscope depicted in FIGS. 8 and 9 . This microscope is described in detail in PCT Application PCT/US99/06097, published as WO99/47964, entitled “Wide Field of View and High Speed Scanning Microscopy,” which is hereby incorporated by reference as if fully set forth herein. It is sufficient to say that the micro objective lens 18 , mounted on a rotary arm 19 for on-axis scanning, is driven in rapid rotary oscillation movement by galvanometer or oscillating motor 3 , whose position is detected by position sensor 43 for the purpose of relating data acquisition to position on the specimen. By employing a pin hole or other restriction 103 in front of the light sensor 95 , the resulting confocal microscope has a significantly limited depth of field, which could not be calibrated well by prior techniques but which can be readily calibrated to high accuracy using calibration tools featuring broad band surface emission by fluorescence as has been described here.
FIG. 9 depicts employing a calibration tool as described above with a flying objective microscope, whereas FIG. 10 depicts the subsequent scanning of a microarray using the same instrument, now calibrated, to achieve quantified fluorescence microscopy that can readily be compared to the results produced by other microscopes that have been calibrated in the same way.
A rudimentary analysis of the amount of fluorescence required to stimulate an actual specimen is presented in the following appendix with respect to a commercial confocal fluorescence scanning microscope, based on a microlens carried on a rapidly oscillating arm, the 418 Array Scanner™, available from Genetic MicroSystems, Inc. By following a similar analysis for other instruments one can arrive at suitable fluorescent levels for those instruments; by considering the sets of data for all instruments a standard calibration tool is obtainable.
Appendix
Analysis of Fluorescence Required for a Practical Wide Field of View
Flying Objective Microscope with On-Axis Scanning (418 Array Scanner Available from Genetic MicroSystems, Inc.)
TABLE 1 (1) Illumination Power: 3 mW on specimen at 6.37 nm (2) Delivery efficiency to the PMT Detector: Collection Efficiency: Geometric: 13% .13 Dichroric Transmission .9 nm Emission Filter .6 Approximate Delivery Efficiency to the PMT = .070 (3) 5 V/nW min Gain of PMT = sensitivity = S (4) Approximately 0.5 v full scale. Typical PMT signal = C (5) Assume the weakest PMT is saturated (e.g. Hammamatsu PMT for detection of Σ = 637 nm Response = R = C ÷ S R = .5 V ÷ 5 V/nw = .1 nw @ PMT nw S = .1 nW ÷ .070 = 1.4 nW @ microscope slide (6) Fluorescence Production Rate = 1.4 (10 −9 ) ÷ 3 (10 −3 ) of the order of 1.5 ÷ 3 (10 −6 ) = .5 (10 −6 )
In this table, illumination power represents the amount of power that is typically delivered to the microscope slide for exciting fluorescent emission. The delivery efficiency (2) is defined by three values. The first is the geometric collection efficiency of the lens, based upon the size of the confocal pinhole and the distance to the microscope slide. For the instrument of the example, 13% of the fluorescing light emitted is collected, i.e. the fluorescence light is emitted at the target with spherical distribution, and the instrument collects 13% of that light. That light passes through a dichroic mirror, necessarily involving a loss factor, so that 90% of the light is passed and 10% is reflected elsewhere in the system and is wasted. Finally, in front of the photomultiplyer tube an emission filter passes about 60% of the fluorescent light. The emission filter is a multi-layer optical filter which rejects the excitation light that accompanies the fluorescent energy which is generally centered about 25–30 nanometers away from the wavelength of the excitation laser energy.
The model 418 Array Scanner instrument operates at 532 and 637 nanometer. Another useful wavelength is 473 nanometer. At these wavelengths, for this instrument, the surface layer of fluorescing material in the calibration tool must produce fluorescence power leaving its surface of the order of at least 1 millionth the illumination power reaching a specimen.
The product of the three numbers discussed, 0.13×0.9×0.6, shows that the delivery efficiency is approximately 0.070. Referring further to the table, line 3 relates to the gain of the photomultiplyer tube modules employed in the 418 Array Scanner. The modules with the least gain have a gain of 5 volts per nanowatt, meaning typically around 637 nm Σ, the PMT produces a 5 volt signal for every nanowatt of light reaching it.
At line 4 , the 418 Array Scanner system is such that when a full strength signal is obtained, the instrument produces ½ a volt at the photomultiplyer tube.
Thus by assuming that a desired test material will saturate the weakest photomultiplyer tube, an equation is produced that shows the desired performance of the material. The response of the photomultiplyer tube is equal to the gain times the signal (amount of light falling on the photomultiplyer tube). This gives a signal equal to ½ volt divided by 5 volts per nanowatt, or 0.1 nanowatts of light are obtained at the photomultiplyer tube. By taking the 0.1 nanowatt and dividing it by the efficiency of 0.07, one determines that at the microscope slide 1.4 nanowatts of fluorescent light are produced, or a little higher. Thus, the fluorescence production rate is approximately 1.4 or 1.5×10 −9 which is the nanowatts divided by 3×10 −3 , which is equal to 3 milliwatts. This results in a value of about ½×10 −6 or a factor of 1 million, meaning that for each fluorescing photon reaching the PMT, approximately 1 million photons are required to impinge on the surface layer of fluorescent material.
This shows that the fluorescent efficiency of the fluorophore needs to be approximately 1×10 −6 or higher. It needs to receive 10 6 photons for every photon it emits. Accordingly, the conversion efficiency of a suitable fluorescent reference material needs to be of the order of 1×10 −6 or higher. | 4y
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority under 35 U.S.C. §119(a) to European Application No. 12 178 805.3, filed on Aug. 1, 2012, the entire contents of which are hereby incorporated by reference.
TECHNICAL FIELD
[0002] The invention relates to a machine tool for processing plate-like workpieces, in particular metal sheets.
BACKGROUND
[0003] A representative machine tool for processing plate-like workpieces, in particular metal sheets, is known from EP 0 648 556 A1. This document discloses a turret punch press for sheet metal processing with an O-shaped machine frame. A coordinate guide for the metal sheets to be processed and a tool turret are housed in the inner compartment of the frame. The tool turret is rotatable about a vertical axis and is provided along the circumference thereof with a plurality of storage places for punching tools. A feed motion of the tool turret about the axis of rotation causes the particular punching tool that is required for the workpiece processing to be carried out to be positioned at a processing station of the turret punch press. A tool transfer device loads the storage places of the tool turret with the punching tools required for the forthcoming workpiece processing. Punching tools no longer required are removed by the tool transfer device from the storage places of the tool turret, punching tools that are required are transferred by the tool transfer device to the storage places of the tool turret. In so doing, in addition to approaching the tool turret the tool transfer device approaches a tool magazine spaced from the tool turret; the tool transfer device removes from said tool magazine the punching tools to be supplied to the tool turret and the tool transfer device inserts into said tool magazine the punch tools removed from the tool turret. The storage places of the tool magazine provided for the punching tools are housed in a frame compartment open towards one longitudinal side of the machine frame. The tool transfer device moves in the longitudinal direction of the machine frame between a position in which it is arranged in front of the lateral opening of the frame compartment and a position in which is it located adjacent a punching tool storage place provided on the tool turret. For receiving or transferring a punching tool, the tool transfer device engages in the horizontal direction in the relevant storage place on the tool turret or in the relevant storage place on the tool magazine. During movement along the machine frame the tool transfer device is guided on guide rails running horizontally and offset with respect to each other perpendicularly to a longitudinal lateral wall of the machine frame.
[0004] Other improvements in machine tools for processing plate-like workpieces, in particular metal sheets, are sought.
SUMMARY
[0005] One aspect of the invention features a machine tool for processing plate-like workpieces, in particular metal sheets. The machine tool includes a machine frame having lower and upper frame arms extending in a longitudinal direction of the machine frame and spaced apart in a vertical direction to define a frame compartment. A processing station is supported by the machine frame and configured to interchangeably receive a processing tool for workpiece processing. The machine tool has a first tool magazine disposed at least partially within the frame compartment and defining storage places configured to store processing tools interchangeable at the processing station. The first tool magazine and the processing station are movable relative to each other so as replace a processing tool at the processing station with a processing tool from the first tool magazine. A second tool magazine defines storage places configured to store processing tools remote from the processing station, and is disposed farther than the first tool magazine from the processing station. A tool transfer device has a tool holder configured to hold processing tools during tool transfer between the first and second tool magazines, the tool transfer involving relative motion between the tool holder and at least one of the first and second tool magazines in the longitudinal direction of the machine frame.
[0006] According to this aspect of the invention the remote or second tool magazine includes a magazine platform that protrudes laterally in a horizontal direction with respect to the machine frame and is accessible from above with storage places for processing tools to be interchanged at the processing station. The tool transfer device is mounted above the magazine platform on the relevant longitudinal side of the machine frame. The magazine platform is accordingly provided on the outside of the machine frame and is readily accessible there for the tool transfer device tool holder arranged above the magazine platform. The arrangement of the magazine platform and the tool transfer device on the outside of the machine frame in particular provides an opportunity for existing machine tools that do not have a remote tool magazine to be retrofitted with such a tool magazine at no great expense.
[0007] The remote tool magazine, including the magazine platform, can in principle be designed as a unit separate from the machine frame of the machine tool, but a magazine platform connected to the machine frame is preferred. By virtue of said connection the magazine platform is arranged in a permanently defined manner with respect to the remaining functional units of the machine tool, more especially also with respect to the tool transfer device. This circumstance facilitates in particular a positionally accurate relative movement of the magazine platform and the tool transfer device.
[0008] There are different options for configuring the tool magazine that is close to the station. In a preferred construction, the tool magazine close to the station comprises a horizontal carrier arranged at least partially in the frame inner compartment of the machine frame and extending transversely to the longitudinal direction of the machine frame. Storage places for processing tools are provided adjacent each other in the longitudinal direction of the carrier. The storage places of such a linear magazine are easily accessible for the tool transfer device. So that all storage places arranged along the horizontal carrier can be reached by the tool transfer device, the horizontal carrier and the tool transfer device are movable relative to each other in the longitudinal direction of the horizontal carrier. For that purpose the horizontal carrier of the linear magazine is preferably movably guided in the longitudinal direction thereof on the machine frame.
[0009] In order to transfer processing tools between the remote tool magazine and the tool magazine close to the station, a tool transfer movement is carried out in the longitudinal direction of the machine frame. This tool transfer movement is a relative movement between the tool holder of the tool transfer device on the one hand, and the remote tool magazine and/or the tool magazine close to the station on the other hand.
[0010] In order to carry out the tool transfer movement, the tool holder of the tool transfer device may be moved on the machine frame in the longitudinal direction of the frame into a receiving/transfer position remote from the station at the tool magazine remote from the station, and into a receiving/transfer position close to the station at the tool magazine close to the station. Advantageously, the tool holder of the tool transfer device constitutes only a small mass to be moved. This circumstance is accompanied in particular by high positional accuracy when approaching the receiving/transfer positions at the remote tool magazine and at the tool magazine close to the station. In addition, the tool transfer movement can be achieved by means of comparatively low-power and hence inexpensive drives.
[0011] In addition or as an alternative, in a further embodiment the tool magazine close to the station and/or the magazine platform of the remote tool magazine are/is movable with a tool transfer movement along the machine frame. In particular the tool holder of the tool transfer device can be fixedly connected to the machine frame. The tool magazine close to the station and/or the magazine platform of the remote tool magazine takes on at least part of the tool transfer movement. This option for producing the tool transfer movement is appropriate in particular in cases in which the tool magazine close to the station is movable in any case in the longitudinal direction of the machine frame. This is the case, for example, when the tool magazine close to the station is integrated in a coordinate guide for the workpieces to be machined. If the tool magazine close to the station, which tool magazine is already provided with a drive, takes on the complete tool transfer movement between the remote tool magazine and the tool magazine close to the station, then no separate drive is needed for the tool transfer.
[0012] In some embodiments the magazine platform of the remote tool magazine actively performs a tool transfer movement that is advantageously generated by means of the movable tool magazine close to the station.
[0013] If, for the tool transfer movement, the magazine platform of the remote tool magazine can be detachably coupled to the tool magazine which is close to the station and is in any case driven, then the connection of the magazine platform to the tool magazine close to the station can be limited to those cases in which a tool transfer movement has to be performed. In the case of other movements, the magazine platform does not need to be moved by the tool magazine close to the station.
[0014] In a further preferred embodiment, the magazine platform of the remote tool magazine, which magazine platform is disengaged from the tool magazine close to the station, is arranged in a rest position away from the receiving/transfer position. In this manner it is ensured that the remote tool magazine not currently in use does not impede the other procedures of the machine tool.
[0015] In the interests of an efficient tool management, in some embodiments the tool holder of the tool transfer device comprises a plurality of tool holding elements that are offset with respect to each other in the direction of the tool transfer movement. By virtue of this feature it is possible in particular to carry out a tool removal operation and a tool transfer operation in immediate succession. If the receiving position of the one tool holding element coincides with the transfer position of the other tool holding element, then only a comparatively short transfer path has to be covered between the take up of the one tool and the transfer of the other tool. In addition, the mutual offset of the tool holding elements in the direction of the tool transfer movement and hence in the longitudinal direction of the machine frame keeps the projection of the tool holder in the transverse direction of the machine frame to a minimum.
[0016] In some embodiments, the tool holder is adjustable in a horizontal direction perpendicular to the longitudinal direction of the machine frame with respect to the magazine platform of the second tool magazine, and advantageously has a large range. The magazine platform of the remote tool magazine can be designed correspondingly for receiving processing tools.
[0017] In a further preferred embodiment the magazine platform of the remote tool magazine is supported interchangeably on a supporting structure of the remote tool magazine. As a result of this feature, the configuration of the remote tool magazine can be adapted in a simple manner to changing requirements. For example, after completion of a processing task a magazine platform fitted with the relevant set of processing tools can be replaced by a magazine platform on which the processing tools required for the succeeding processing are arranged. The magazine platforms can be set up away from the machine tool. Exchange of the magazine platforms can be effected manually, for example.
[0018] Another aspect of the invention features a method of changing processing tools in a machine for processing plate-like workpieces, in particular metal sheets, such as in an automated punching machine. The method includes, in reference to a machine of the type described herein: activating a tool transfer device positioned above a selected processing tool stored in a processing tool storage place of the second tool magazine, such that the tool transfer device holds a processing tool stored in the second tool magazine; initiating a relative motion between the tool transfer device and the first tool magazine in the longitudinal direction of the machine frame, thereby moving the held processing tool to the first tool magazine; releasing the held processing tool and storing the released processing tool in a storage place of the first tool magazine; reducing a distance between the first tool magazine and the processing station; and replacing a processing tool held in the processing station with the stored processing tool.
DESCRIPTION OF DRAWINGS
[0019] FIGS. 1 through 9 sequentially illustrate the replacement of a processing tool in a punching machine for sheet metal processing, with a tool transfer device and a first construction of a remote tool magazine.
[0020] FIGS. 10 and 11 show a tool changeover process in a second embodiment of a punching machine for sheet metal processing.
[0021] Like reference numbers in the figures indicate like elements.
DETAILED DESCRIPTION
[0022] Referring first to FIG. 1 , a machine tool designed as a punching machine 1 for processing metal sheets 2 has a C-shaped machine frame 3 with a lower frame arm 4 and an upper frame arm 5 . The lower frame arm 4 and the upper frame arm 5 extend in the longitudinal direction of the machine frame 3 and are spaced apart from each other in the vertical direction to form a frame inner compartment or throat 6 . At the free end of the lower frame arm 4 and the upper frame arm 5 there is a punching station 7 , hidden in the figures, of conventional construction as the processing station of the punching machine 1 . The punching station 7 comprises in the usual manner a lower tool seat on the lower frame arm 4 and an upper tool seat on the upper frame arm 5 .
[0023] A likewise customary coordinate guide 8 is partially accommodated in the throat 6 of the machine frame 3 . The coordinate guide 8 comprises a cross beam 9 , which is movably guided on the lower frame arm 4 in the longitudinal direction of the machine frame 3 and can be moved by motor in the direction of double arrow 10 . The cross beam 9 in turn guides a horizontally running cross rail 11 , which is arranged partially inside the throat 6 and which is moved by means of a motor drive in the direction of a double arrow 12 transversely to the machine frame 3 . The cross rail 11 is provided with clamping claws 13 and also has storage places 14 for processing tools in the form of punching tools 15 . The punching tools 15 are of conventional construction and accordingly include a punch as the upper tool, a die as the lower tool, and a stripper. The individual parts of each of the punching tools 15 are housed, as is customary, in a tool cassette. The relevant tool cassette is manipulated to manage the punching tools 15 . The punching tools 15 , including the respective associated tool cassettes, are illustrated merely schematically in the figures.
[0024] By means of the clamping claws 13 a metal sheet 2 to be processed is fixed in the customary manner to the coordinate guide 8 . Owing to the fact that the cross beam 9 is movable in the direction of double arrow 10 and the cross rail 11 is movable in the direction of double arrow 12 , the metal sheet 2 can be moved by the coordinate guide 8 in a horizontal processing plane defined by double arrows 10 and 12 . Corresponding movements of the metal sheet 2 are performed in order to position the metal sheet 2 with respect to the punching station 7 of the punching machine 1 for the processing operation and in order to move the metal sheet 2 relative to the punching station 7 during the punching operation. In both cases the metal sheet 2 is supported on a stationary workpiece table 16 of the punching machine 1 .
[0025] With the storage places 14 for punching tools 15 , the cross rail 11 of the coordinate guide 8 forms a tool carrier or a tool magazine that is arranged close to the processing station 7 . Usually, the cross rail 11 is fitted with a punching tool set comprising a plurality of punching tools 15 for the particular sheet metal processing to be carried out. For the sake of clarity, only a maximum of two punching tools 15 are shown on the cross rail 11 in the figures.
[0026] The punching tools 15 are interchanged at the upper tool seat and at the lower tool seat of the punching station 7 in the customary manner by means of the coordinate guide 8 . The mobility of the cross beam 9 of the coordinate guide 8 in the direction of double arrow 10 and the mobility of the cross rail 11 in the direction of double arrow 12 is also used for that purpose. For tool changeover, the coordinate guide 8 first approaches the punching station 7 with an empty storage space 14 on the cross rail 11 . The punching tool 15 inserted at the punching station 7 is subsequently transferred out of the upper tool seat and out of the lower tool seat of the punching station 7 to the previously empty storage place 14 of the cross rail 11 . The punching tool 15 required for the next processing step and which is held ready on the cross rail 11 is subsequently inserted into the upper tool seat and into the lower tool seat of the punching station 7 by corresponding movement of the coordinate guide 8 .
[0027] During tool changeover at the punching station 7 the metal sheet 2 to be processed is released from the coordinate guide 8 and rests on the workpiece table 16 . Once the tool changeover at the punching station 7 is completed, the metal sheet 2 to be processed is gripped by the coordinate guide using the clamping claws 13 and then to carry out the impending processing is moved relative to the punching tool 15 inserted at the punching station 7 .
[0028] The punching tools 15 stored at the storage places 14 of the cross rail 11 come from a tool magazine 17 remote from the station, which tool magazine is provided close to the throat 6 at the rear end of the machine frame 3 . The remote tool magazine 17 has a magazine platform 18 , which is pushed interchangeably into a supporting structure 19 of the remote tool magazine 17 , the supporting structure being secured to the machine frame 3 . The magazine platform 18 is thus detachably connected to the machine frame 3 . The magazine platform 18 has on the top face thereof storage places 20 for punching tools 15 . In the example illustrated, four storage place rows running parallel to one another in the longitudinal direction of the machine frame 3 , each row having six storage places 20 , are provided on the magazine platform 18 . The magazine platform 18 can accordingly store a total of twenty-four punching tools 15 . If the machine frame 3 has a suitable length, a storage place row can have, for example, seven storage spaces 20 . Handles 21 , 22 on the magazine platform 18 are used for handling the magazine platform 18 during exchange thereof.
[0029] In order to transfer punching tools 15 between the remote tool magazine 17 and the tool magazine close to the station (i.e., the cross rail 11 of the coordinate guide 8 ), a tool transfer device 23 is used. Operation of the tool transfer device 23 is illustrated in FIGS. 1 to 9 . The tool transfer device comprises a tool holder 24 with two tool holding fixtures in the form of tool grippers 25 , 26 . The tool grippers 25 , 26 are of conventional construction. They can be opened and closed by motor and are numerically controlled.
[0030] The tool holder 24 with both tool grippers 25 , 26 is movably guided on a transfer carriage 27 of the tool transfer device 23 in the transverse direction of the machine frame 3 . In addition, the tool grippers 25 , 26 and the tool holder 24 can be raised and lowered vertically with respect to the transfer carriage 27 . In its turn the transfer carriage 27 is movable along the upper frame arm 5 of the machine frame 3 on guide rails 28 , 29 fixed to the machine frame. All movements of the tool holder 24 and of the transfer carriage 27 of the tool transfer device 23 are generated by means of drive motors, not shown in detail. A programmable numeric control 30 indicated in outline in FIG. 1 controls the drive motors of the tool transfer device 23 and also all other essential functions of the punching machine 1 .
[0031] If an empty storage place 14 on the cross rail 11 is to be fitted with a specific punching tool 15 stored in the tool magazine 17 remote from the station, then the coordinate guide 8 first moves into its rear end position on the machine frame 3 . Subsequently or simultaneously the tool holder 24 is moved with one of the tool grippers 25 , 26 , in the example illustrated with tool gripper 25 , along the upper frame arm 5 of the machine frame 3 into a receiving position above the punching tool 15 that is to be interchanged on the cross rail 11 ; at this point the punching tool 15 is still stored on the magazine platform 18 of the remote tool magazine 17 . For this purpose the transfer carriage 27 of the tool transfer device 23 moves along the guide rails 28 , 29 .
[0032] From the position above the punching tool 15 to be transferred, the opened tool gripper 25 is lowered towards the magazine platform 18 of the remote tool magazine 17 until it is located at the punching tool 15 to be picked up. By appropriate operation of the tool gripper 25 the punching tool 15 is fixed to the tool gripper 25 . The situation is then as shown in FIG. 1 . With the tool holder 24 still located in the receiving position at the remote tool magazine 17 , the tool gripper 25 with the punching tool 15 fixed thereto is raised and the punching tool 15 is consequently removed from its storage place 20 on the magazine platform 18 of the remote tool magazine 17 ( FIG. 2 ).
[0033] The tool holder 24 is subsequently moved, jointly with the punching tool 15 held thereon, by the transfer carriage 27 with a tool transfer movement along the machine frame 3 in the direction towards the cross rail 11 until the tool holder 24 has reached its transfer position, close to the station, at the cross rail 11 ( FIG. 3 ). Once the tool holder 24 assumes its transfer position close to the station, then the punching tool 15 on the tool gripper 25 is positioned above the particular storage place 14 of the cross rail 11 to which it is to be transferred. The cross rail 11 is correspondingly positioned relative to the cross beam 9 of the coordinate guide 8 in the direction of double arrow 12 .
[0034] For transfer of the punching tool 15 to the cross rail 11 , the tool gripper 25 of the tool holder 24 is lowered vertically and the punching tool 15 is thereby inserted into the relevant storage place 14 on the cross rail 11 ( FIG. 4 ). The punching tool 15 is subsequently released from the tool holder 24 by opening the tool gripper 25 . After transfer of the punching tool 15 to the cross rail 11 , the tool gripper 25 of the tool holder 23 is raised ( FIG. 5 ).
[0035] If a further punching tool 15 is to be transferred from the remote tool magazine 17 to the cross rail 11 , then the transfer carriage 27 of the tool transfer device 23 moves with the tool holder 24 in the direction towards the rear end of the machine frame 3 until the tool holder 24 is located with the tool gripper 25 or with the tool gripper 26 in the receiving position remote from the station above the relevant punching tool 15 on the magazine platform 18 of the remote tool magazine 17 . Depending on the position of the storage place 20 of the punching tool 15 in question, it may be necessary to move the tool gripper 25 , 26 that is used for the tool transfer perpendicularly to the machine frame 3 , in order to be able to access a punching tool 15 of the middle row of storage places 20 or one of the rows of storage places furthest from the machine frame on the magazine platform 18 of the remote tool magazine 17 .
[0036] In the manner described above, the punching tool 15 to be transferred is picked up from the magazine platform 18 of the remote tool magazine 17 and inserted at the cross rail 11 .
[0037] During the movement along the machine frame 3 , the tool holder 24 with the two tool grippers 25 , 26 is always located on the transfer carriage 27 in the end position close to the frame perpendicular to the machine frame 3 . Mass-related forces that would arise if the tool holder 24 was spaced further away from the machine frame 3 during its movement along the machine frame 3 are in this manner avoided.
[0038] The sequence of a tool transfer from the cross rail 11 of the punching machine 1 to the remote tool magazine 17 is illustrated in FIGS. 6 to 9 . By means of a corresponding movement of the cross rail 11 along the cross beam 9 of the coordinate guide 8 , the punching tool 15 to be transferred was previously arranged beneath the tool holder 24 moved into its receiving position close to the station.
[0039] The tool holder 24 is located in the receiving position close to the station in FIG. 6 . The tool gripper 25 is lowered vertically and has gripped the punching tool 15 detachably located at a storage place 14 of the cross rail 11 .
[0040] Proceeding from the situation as shown in FIG. 6 , the tool gripper 25 with the punching tool 15 affixed thereto is raised ( FIG. 7 ). The transfer carriage 27 with the tool holder 24 and the punching tool 15 is subsequently moved in the direction towards the rear end of the machine frame 3 until the tool holder 24 has reached its transfer position remote from the station and the punching tool 15 held at the tool gripper 25 is located above the storage place 20 provided for the punching tool 15 on the magazine platform 18 of the remote tool magazine 17 . The tool gripper 25 , together with the punching tool 15 , is now lowered and the punching tool 15 is thereby transferred to its assigned storage place 20 ( FIG. 8 ). The tool gripper 25 now releases the punching tool 15 and is subsequently raised into its vertical starting position ( FIG. 9 ). The tool transfer device 23 is thus ready for a further tool change.
[0041] The punching machine 1 ′ shown in FIGS. 10 and 11 differs from the punching machine 1 ′ shown in FIGS. 1 to 9 in the structural design of the remote tool magazine remote and the structural design of the tool transfer device.
[0042] The punching machine 1 ′ shown in FIGS. 10 and 11 has a tool magazine 40 which is remote from the station and is movable in the longitudinal direction of the machine frame 3 . For that purpose the supporting structure 19 of the remote tool magazine 40 is guided jointly with the magazine platform 18 on guide rails 41 , 41 extending in the longitudinal direction of the lower frame arm 4 . Four rows, each with six storage places 20 for punching tools 15 , are provided on the magazine platform 18 . A tool transfer device 43 comprises a tool holder 24 that is stationary in the longitudinal direction of the machine frame 3 . The tool holder 24 immovable in the longitudinal direction of the machine frame 3 is movably guided in the transverse direction of the machine frame 3 on a supporting frame 44 firmly connected to the machine frame 3 . The tool grippers 25 , 26 can be raised and lowered in the vertical direction.
[0043] In order to transfer a punching tool 15 from the magazine platform 18 of the remote tool magazine 40 to a storage place 14 on the cross rail 11 , the remote tool magazine 40 is positioned with its magazine platform 18 in the longitudinal direction of the machine frame 3 relative to the stationary tool holder 24 of the tool transfer device 43 . The positioning movement of the remote tool magazine 40 is generated by the coordinate guide 8 . For that purpose the remote tool magazine 40 is connected by means of a switchable coupling 45 ( FIG. 11 ) to the cross beam 9 and via the latter also to the cross rail 11 of the coordinate guide 8 . By moving the coordinate guide 8 along the machine frame 3 the magazine platform 18 of the remote tool magazine 40 can be positioned with respect to the tool holder 24 of the tool transfer device 43 in such a manner that the tool holder 24 , together with the tool gripper 26 provided for manipulating the punching tool 15 in question, is located in the receiving position above the relevant punching tool 15 . After the magazine platform 18 of the remote tool magazine has been positioned, the tool gripper 26 is lowered in the vertical direction and grips the punching tool 15 . Together with the punching tool 15 the tool gripper 26 is then raised. This produces the configuration shown in FIG. 10 .
[0044] Proceeding from this operational state, the coordinate guide 8 moves towards the rear end of the machine frame 3 until the relevant storage place 14 on the cross rail 11 is located beneath the punching tool 15 affixed to the tool gripper 26 . In so doing the remote tool magazine 40 connected to the cross beam 9 of the coordinate guide 8 is displaced towards the rear end of the machine frame 3 . By lowering the tool gripper 26 of the tool holder 24 into its transfer position, the punching tool 15 is then transferred to the storage place 14 provided for it on the cross rail 11 .
[0045] Once the cross rail 11 has been fitted with the punching tools 15 required for the subsequent sheet metal processing, the coupling 45 is released and as a result the coordinate guide 8 is separated from the remote tool magazine 40 . The coordinate guide 8 , without out having to move the tool magazine 40 along with it, can then carry out the movements required for the sheet metal processing to be performed and the tool change at the punching station 7 , including movements in the longitudinal direction of the machine frame 3 ( FIG. 11 ). The remote tool magazine 40 , now disengaged from the coordinate guide 8 , remains in its rest position at the rear end of the machine frame 3 . In order to carry out a further tool change over, the remote tool magazine 40 can be retrieved from its rear end position by the coordinate guide 8 .
[0046] A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. Accordingly, other embodiments are within the scope of the following claims. | 4y
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CROSS-REFERENCED TO RELATED APPLICATIONS
Not applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable
BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to solenoid valves. More specifically, the present invention relates to solenoid valves that have minimal power requirements.
II. Related Art
Valves are commonly used to control the flow of fluids in a hydraulic or pneumatic system. Valves are used to turn flow on or off, modulate flow or to direct flow along alternative paths. Two-port valves, for example, are used to turn flow on or off or to modulate the amount of flow past the valve. Valves with more than two ports typically have (a) either one pressure (inlet) port and multiple outlet ports, or (b) one outlet port and multiple inlet ports. In the first case, the valve is used to connect the inlet port to a selected output port to permit fluid to flow from the inlet to the selected outlet. In the second case, the valve is used to connect the outlet port to a selected input port to permit flow from the selected input port to the output port.
Solenoid valves have two main components, the valve and the solenoid. The solenoid is a helical coil of insulated wire in which an axial magnetic field is established by the flow of electric current through the coil. Many solenoid valves have a plunger and a spring arranged along the axial magnetic field produced by the solenoid. The spring biases the plunger toward a position which closes the valve. Application of current to the solenoid creates a magnetic field sufficient to overcome the force of the spring and open the valve.
A problem with solenoid valves known in the prior art is that substantial amounts of electricity are required to overcome the force of the spring to move the plunger and then retain the plunger in the open position. This adds to the cost of operation and also makes solenoid valves unacceptable for use in a variety of environments. There is a real need for an efficient solenoid type valve which can operate at low power.
SUMMARY OF THE INVENTION
Solenoid valves made in accordance with the subject invention typically include a housing, an electromagnet, an electronic circuit, a valve assembly and a lever. The housing surrounds the other aforementioned components and defines a first axis and a second axis laterally spaced from and parallel to the first axis. The housing also has a flow path. The flow path has both an inlet and outlet. The outlet is centered on the second axis of the housing.
The electromagnet includes a core and coil assembly. The core is preferably made of a soft magnetic material as opposed to an ordinary mild steel. One example of such a soft magnetic material is an alloy comprising more than 45% nickel and more than 45% iron. The core is positioned within the housing along the first axis. The coil assembly includes at least one helical coil surrounding the core. The coil assembly is electrically coupled to the electronic circuit. The electronic circuit is adapted to apply both a shifting voltage and a holding voltage to the coil assembly. Application of either of such voltages creates a magnetic field along the first axis.
The valve assembly includes a shaft extending between a first end and a second end along the aforementioned second axis. The shaft is movable along the second axis between a first position and a second position. A spring is coupled to the shaft and biases the shaft toward the first position. At least two valves are coupled to and move with the shaft. More specifically, a first poppet valve is coupled to the shaft intermediate the first and second ends of the shaft and a second poppet valve is coupled to the shaft intermediate the first poppet valve and the second end.
The lever also comprises an alloy of soft magnetic material. As is the case with the core, an example of a suitable material for the lever is an alloy comprising more than 45% nickel and more than 45% iron. The lever has a receiver and a plate. When positioned in the housing with the other components, the receiver is mated with the first end of the valve assembly's shaft and the plate extends from the receiver over the electromagnet. The plate has an engagement surface facing the electromagnet. The engagement surface of the plate has two end portions, a center portion and a recessed portion between each of the two end portions and the center portion.
When the shaft of the valve assembly is in its first position, there is a gap between the core and the center portion of the engagement surface of the plate. Application by the electrical circuit of the aforementioned shifting voltage to the coil assembly draws the center portion into contact with the core of the electromagnet thereby moving the shaft of the valve assembly from the first position to the second position. The current may then be reduced to a holding current, i.e. a current sufficient to hold the shaft of the valve assembly in the second position.
A manifold is coupled to the housing, i.e., either by integrally forming the manifold with the housing or attaching the manifold to the housing. In either case, the manifold has a pressure path in communication with the inlet of the flow path of the housing as well as both a port path and an exhaust path, which are selectively in communication with the outlet of the flow path of the housing. When the solenoid valve is fully assembled, the first poppet valve seats against a portion of the housing when the shaft is in the first position to seal the flow path and the second poppet valve seals against a portion of the manifold when the shaft is in the second position to seal the exhaust path.
Various other features may be included. For example, the coil assembly may have first and second coils. In such a case, the electronic circuit may be adapted to supply a shifting current to the first coil and a holding current to the second coil. To reduce the current necessarily supplied to the solenoid valve, the electronic circuit may include a charging capacitor which, when discharging, supplies the shifting current. The electronic circuit may also provide a step down of the voltage supplied to the circuit. In most cases, the electronic circuit will provide to the coil a shifting current to overcome the force of the spring and move the shaft to the second position and a holding current to retain the shaft in the second position. The shifting power will typically be higher than the holding power.
The voltages provided to the electronic circuit may vary. For example, the circuit may be adapted to operate at DC voltages in the range of between about 6 volts and 30 volts. Alternatively, the circuit may be adapted to operate at voltages as low as 24 volts direct current to as high as 240 volts alternating current. This enables the solenoid valve to be adapted to accommodate the available power at the location where the valve is to be employed. The electronic circuit ensures that only the minimum power required for operation of the valve is actually employed.
A complete understanding of the invention will be obtained from the following description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded view of a solenoid valve made in accordance with the present invention;
FIG. 2 is an exploded side view of the solenoid valve of FIG. 1 ;
FIG. 3 is an alternative exploded perspective view of the solenoid value of FIG. 1 ;
FIG. 4 is a partial cross-sectional view of the solenoid valve of FIG. 1 ;
FIG. 5 is a bottom view showing the engagement surface of the lever of the solenoid valve of FIG. 1 ;
FIG. 6 is a schematic diagram showing a first embodiment of the electronic circuit of the solenoid value of FIG. 1 ; and
FIG. 7 is a second embodiment of the electronic circuit.
DETAILED DESCRIPTION
This description of the preferred embodiment is intended to be read in connection with the accompanying drawings, which are to be considered part of the written description of this invention. In the description, relative terms such as “lower”, “upper”, “horizontal”, “vertical”, “above”, “below”, “up”, “down”, “top”, and “bottom”, as well as derivatives thereof (e.g., “horizontally”, “downwardly”, “upwardly”, etc.) should be construed to refer to the orientation as then described or as shown in the drawings under discussion. These relative terms are for convenience of the description and do not require that the apparatus be constructed or operated in the orientation shown in the drawings. Further, terms such as “connected”, “connecting”, “attached”, “attaching”, “joined”, and “joining” are used interchangeably and refer to one structure or surface being secured to another structure or surface or integrally fabricated in one piece, unless expressly described otherwise.
The solenoid valve 10 shown in the drawings includes a housing comprising a base 12 and a cover 14 . A separate manifold 16 is also shown. The manifold 16 may alternatively be integrally formed with the base 12 .
The housing defines a first axis represented by line 18 in FIG. 4 and a second axis represented by line 20 in FIG. 4 . In addition to containing the other components of the valve described below, the housing also contains a flow path 21 having an inlet 22 and an outlet 24 , as best shown in FIG. 3 . The manifold 16 has pressure port 26 coupled to and in communication with the inlet 22 . The manifold also has an exhaust path 28 axially aligned with the outlet 24 and a port path 30 . The exhaust path 28 and the port path 30 are selectively in communication with the outlet 24 of the flow path of the housing by operation of the valve 10 .
Centered on the first axis 18 is a magnet channel 31 adapted to hold an electromagnet 32 and a circuit board 40 . The electromagnet 32 has a core 34 also centered on the first axis 18 . Preferably, the core will be made of a soft magnetic material as opposed to ordinary mild steel. One such soft magnetic material is a metal alloy comprising more than 45% nickel and more than 45% iron. This nickel/iron alloy material is physically durable and reacts well to the cycling of power on and off to the coil(s) such that a substantial magnetic field is only present when electrical energy is applied to the coils. This alloy may be prohibitively expensive in some applications in which case other soft magnetic materials may be employed which have similar characteristics in terms of physical durability and reaction to cycling power on and off. Surrounding core 34 is a coil assembly 36 comprising at least one coil winding 38 . A second coil winding 39 may also be provided on the core 34 . The core 34 is preferably made of soft magnetic material. An example of such a soft magnetic material is an alloy containing more that 45% nickel and more than 45% iron. One such alloy is available from Carpenter Technology Corporation of Reading, Pa. This alloy is 48% nickel, 0.5% manganese, 0.35% silicon, 0.02% carbon and the remainder of the composition is iron. Other soft magnetic materials suitable for use include a silicon iron or a ferritic stainless steel.
An electronic circuit board 40 is shown in FIGS. 1-4 . Two embodiments of the circuit contained on the circuit board 40 are shown in FIGS. 6 and 7 . These circuits will be discussed in greater detail below after the mechanical features of the valve are described.
A valve assembly 50 ( FIG. 4 ) comprises a shaft 52 having a first end 54 and a second end 56 . A coil compression spring 58 surrounds the shaft 52 . The spring has a first spring end 60 and a second spring end 62 ( FIG. 2 ). When the valve assembly 50 is positioned in a channel 51 in the housing base 12 , the second end 56 of shaft 52 is able to pass from above through the exhaust 28 of the manifold. The diameter of the spring 58 is larger than the outlet 24 such that the portion of the base 12 of the housing surrounding outlet 24 acts as a stop 63 against the second end 62 of spring 58 . Adjacent the first end 54 of the shaft 52 is a e-clip catching recess 64 which cooperates with a washer 66 and e-clip 68 to couple the first end 60 of spring 58 to the shaft 52 . More specifically, the washer 66 is sandwiched between the first end 60 of the spring 58 and the spring clip 68 . The e-clip 68 fits into the clip catching recess 64 such that the e-clip 68 is securely affixed to the shaft 52 . In this fashion, the compression spring 58 is coupled to the shaft 52 between the stop 63 that surrounds outlet 24 and the washer 66 . The force of the spring 58 against the washer 66 and the portion of base 12 surrounding outlet 24 biases the shaft 52 upwardly toward a first position.
Several other significant features are associated with shaft 52 . First, a poppet valve or seal 70 surrounds the shaft 52 intermediate the first end 54 and the second end 56 of the shaft 52 . As shown in the drawings, the poppet valve 70 is proximate the second end 56 of the shaft 52 . Second, a further poppet valve or seal 72 surround the shaft 52 intermediate the first end 54 of the shaft 52 and the poppet valve 70 . In the drawings, the poppet valve 72 is proximate the poppet valve 70 . A shaft seal 74 may also be provided between the first end 54 of the shaft and the poppet valve 72 .
The spacing of these three seals along the shaft 52 is dictated by the geometry of the base 12 and manifold 16 . Specifically, the first poppet valve 72 must be able to fully engage and seal against the wall surrounding outlet 24 of the base 12 of the housing when the shaft is in the first position, i.e., the position caused by the biasing force of the spring 58 . Further, when the shaft 52 is forced down into a second position by energization of the solenoid coil 32 , the second poppet valve 70 must seal against the wall surrounding the exhaust path 28 of the manifold 16 . Further still and with reference to FIG. 4 , the shaft seal 74 must at all times be above the location where the channel from the inlet 22 of the base 12 intersects the channel in which the shaft 52 resides so that flow is direct from inlet 22 to outlet 24 and fluids do not pass through the other portions of the housing. The shaft seal 74 engages a wall section 75 of the base 12 between the stop 63 and the flow path 21 which partially defines the channel 51 in which the shaft 52 resides.
Based on the foregoing description, it should be clear that when the shaft 52 is raised by action of the compression spring 58 into the first position, the first poppet valve 72 seals against the portion of the base 12 surrounding the outlet 24 and shaft seal 74 seals against the wall section 75 . Thus, flow from the pressure port 26 and inlet 22 is blocked. Likewise, when the force of spring 58 is overcome and the shaft is move downwardly into the second position, the first poppet valve 72 unseals, the second poppet valve seals against the wall of the manifold surrounding the exhaust path 28 , and the shaft seal 74 still is sealed against the wall section 75 . Thus, fluids are able to flow along a path from the pressure port 26 of the manifold, through the inlet 22 , the flow path 21 and the outlet. 24 of the housing and out the port path 30 of the manifold. The shaft seal 74 prevents flow into other portions of the housing and the second poppet valve 70 prevents flow out the exhaust port 28 .
Of course, some mechanism must be provided to overcome the force of spring 58 (a) to move the shaft 52 from its first elevated position to its second position seen in FIG. 4 and (b) then hold the shaft 52 in its second position. In the embodiment illustrated in the drawings, this mechanism comprises the electromagnet 32 working in conjunction with a lever 80 .
The lever 80 , illustrated in FIG. 5 , is made of a material which is the same or similar to the soft magnetic material of the core. The material must be physically durable to prevent flaking and erosion of the lever 80 and core 32 . The lever 80 has a receiver 82 . The receiver 82 has a recess 84 which receives and mates with the first end 54 of the shaft 52 . The lever also includes a plate 86 extending from the receiver 82 . The plate 86 has an engagement surface 88 which faces the electromagnet 32 . The engagement surface 88 has two end portions 90 and 92 , a center portion 94 and two recessed portions 96 and 98 . Recessed portion 96 is located between the center portion 94 and the end portion 90 . Recessed portion 98 is located between the center portion 94 and the end portion 92 .
When assembled, the engagement surface 88 of the plate 86 is over and in the face-to-face relation with the electromagnet 32 . More specifically, the center portion 94 of the plate 86 resides over the core 34 of the electromagnet 32 and the recessed portions 96 and 98 reside over the coil assembly 36 . Cover 14 is adapted to hold end portion 90 of lever 80 in constant contact with the core 34 to reduce the effective air gap. Further, the first end 54 of shaft 52 resides in the recess 84 of receiver 82 . When the electromagnet 32 is not sufficiently energized to overcome the force of spring 58 , such that the shaft is urged by spring 58 to its first position, the shaft 52 holds the engagement surface of the plate 86 away from the upper end of electromagnet 32 such that there is a gap between the top of the core 34 and the center portion 94 of the lever 80 . When the electromagnet 32 is energized, a magnetic field is created which attracts the plate 86 down until the center portion 94 comes into contact with the core 34 . In this fashion, the lever 80 and the electromagnet 32 cooperate to apply a downward force to the shaft 52 sufficient to overcome the force of spring 58 , thereby moving the shaft 52 from its first position to its second position. When power to the electromagnet 32 is shut off (or reduced below the level required to hold the shaft 52 in the second position), the spring 58 returns the shaft 52 to the shaft's first position.
Application of power to the electromagnet 32 is controlled by the circuitry on circuit board 40 . FIGS. 6 and 7 show two alternative circuit arrangements. Both circuits are designed to provide a first shifting current to the electromagnet 32 . When this first shifting current is applied, the electromagnet 32 and lever 80 cooperate to shift the shaft 52 from its first position to its second position. Both of these circuits are also able to provide a second holding current to electromagnet 32 . The second holding current is less than the first shifting current. While this second holding current is applied, the electromagnet 32 and the lever 80 cooperate to hold the shaft 52 in its second position. When the shaft 52 is to be returned to its first position, power to the electromagnet 32 is cut off by the circuits FIGS. 6 and 7 .
The circuits may further provide additional functions. For example, if the coil assembly has a first coil 38 and a second coil 39 , the circuit can supply the first shifting current to the first coil and then the second holding current to the second coil. Alternatively, currents can be supplied to both coils 38 and 39 for shifting the shaft 52 from the first position to the second position. Then, the current to one of coils 38 and 39 can be turned off with the current still supplied to the other coil and being sufficient to hold the shaft 52 in the second position.
Further, the circuit may include a charge capacitor which accumulates the necessary shifting voltage. Discharge of the capacitor shifts the shaft 52 . The circuit then continues to supply the lower holding power. This arrangement is advantageous if the current supplied to circuit board 40 would otherwise be inadequate to shift the shaft 52 from its first position to its second position. Likewise, when the voltage supplied to circuit board 40 exceeds the requirements for shifting and/or holding, the circuit of circuit board 40 may provide a step down of the voltage. The circuit may also include components which filter and/or rectify the current to convert an AC input into a DC output. Further still, the circuit can operate in DC voltage ranges as low as between about 6 volts and 30 volts. Alternatively, the electronic circuit can be adapted to operate at voltages as low as 24 volts direct current to as high as 240 volts alternating current.
FIG. 6 and FIG. 7 show two alternative circuit arrangements. The circuit of FIG. 6 is employed when a single coil is used. The circuit of FIG. 7 is employed when two coils are used.
In FIG. 6 , input voltage signals are supplied to the circuit at solder connections 100 and 101 . The voltage is then filtered by an EMI filter 102 . Voltage then is applied to an AC to DC bridge rectifier 103 . Depending on the particular application, the voltage from the rectifier 103 may be quite high (over 60 v. AC) so it is passed through a stepdown circuit 104 comprising MOSFETS designed to step down the voltage so the voltage at the terminal labeled “vcoil” is in the range of about 55 to 60 volts. The circuitry in box 105 is essentially a 5 volt power supply for the internal electronics.
An op amp current source is illustrated in box 106 . The current source circuitry in box 106 ensures the current output to the coil of the electromagnet is consistent through the entire voltage range.
The circuitry in box 110 initially changes the current source in box 106 to a higher current level which provides a higher current to the coil assembly 36 necessary for shifting the shaft 52 of the valve from the first position to the second position. The circuitry in box 110 then changes the current source in box 106 to a lower current level after a time delay determined by C 6 and R 15 which provides a lower current to the coil assembly 36 to hold the shaft 52 in the second position. The coil 38 of the coil assembly 36 is connected to the circuit at P 1 and P 2 in box 112 . The capacitor 114 stores current pulses from step-down circuit 104 when voltage is low to power the circuit.
The alternative circuit of FIG. 7 is designed to be used with a dual coil electromagnet 32 having both coils 38 and 39 . The circuit of FIG. 7 is coupled to an input signal source via connections 120 and 121 . An EMI filter is provided in box 122 and an AC to DC bridge rectifier is provided in box 124 . The MOSFET switches and capacitors in box 126 are provided to supply power to shift the coil. Voltage detector 128 detects the voltage VC on the capacitors of box 126 . The voltage detector has a gate 129 to provide a time delay via R 6 and C 11 to make sure VDD is stabilized before Vc is connected to the shift coil. The flip-flop 130 controls the on/off state of MOSFET switches Q 3 and Q 4 . The circuitry in box 132 comprises a second voltage detector which turns on the chips. Box 134 is a voltage regulator which supplies 5.35v to the hold coil 39 . Switch Q 3 controlled by flip-flop 130 turns circuit 136 on to deliver current to the “shift” coil 38 until Q 3 turns off by the time delay provided by C 12 and R 7 . Q 4 in box 140 ensures power is delivered to the “hold” coil via circuit 138 until the power to the circuit shuts off. The circuit 140 makes sure Q 1 switch transistor in box 126 is shut off whenever Q 4 is on. As such, the circuit of FIG. 7 centrally supplies a “hold” current to the first coil 39 until the power to circuit shuts off and turns on the shift coil 38 only when necessary to move the shaft 52 from its first position to second position.
Various modifications may be made without deviating from the invention. For example, the valve has been described as “open” when the shaft is in its first position and “closed” when in its second position. The opposite may be the case. Likewise, the shaft 52 has been described and shown as being on the outlet side of the flow path 21 . The shaft 52 could also be placed on the inlet side of the flow path 21 . The foregoing description is intended to explain, but not limit the invention as defined by the following claims. | 4y
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[0001] The present invention relates to vehicle parts and components, and the preferred embodiments relate to, e.g., systems and methods for providing vehicle storage and for mounting electronic devices within vehicles, such as, most particularly, trucks or commercial vehicles.
BACKGROUND
[0002] In modern times, vehicles, such as, e.g., trucks, buses, cars and the like, often include a variety of electronic devices for an assortment of purposes. By way of example, vehicles can often include one or more of the following electronic devices: citizens band (CB) radios; AM/FM radios; cassette players; CD players; DVD players; video players; cellular phones; global position system (GPS) devices; radar detectors; entertainment devices; computers; etc. Often, these electronic devices are ancillary electronic devices that are not required for the operation of the vehicle itself, but for other purposes (such as, e.g., for business use or operator convenience) during the time period in which the operator is within the vehicle.
[0003] However, along with this increase in the number of ancillary electronic devices comes the need for features and structures to accommodate these ancillary electronic devices. The requirements imposed upon vehicle dash boards, consoles and other interior elements have, thus, increased over recent years, becoming increasingly complex and costly. Among other things, consoles often need to accommodate a variety of ancillary electronic devices. Meanwhile, there is also an increasing need to provide vehicle operators with increased vehicle storage space. As the complexities of vehicle dash boards, consoles and the like increase so do the costs related to the manufacture of these components.
[0004] While the foregoing issues are germane to both family vehicles (such as, e.g., cars and the like) and commercial vehicles (such as, e.g., trucks, buses and the like), these issues are often more significant in the context of commercial vehicles because, among other things, commercial entities often have business needs to, among other things, a) limit costs, b) increase productivity, and c) reduce equipment down time.
[0005] With reference to FIG. 7 , in some existing trucks of the present assignee, an overhead compartment 10 has been implemented for storage and for supporting a CB radio. In such implementations, the compartment 10 has a length in a lateral direction L that is substantially smaller than a width of the truck in which the compartment 10 is installed. In order to mount a CB radio (not shown), a mounting strap 15 (e.g., a strap that is manually attached using hook and loop fastening fabric such as, e.g., VELCRO fastening fabric) has been used to retain the CB radio. In order to mount the compartment 10 within a vehicle, the compartment 10 has been fixedly attached to a headliner (not shown) of the truck via a plurality of mounting brackets BK, which facilitate attachment to the headliner via bolts B.
[0006] While the system shown in FIG. 7 provides convenient overhead access for an operator, it is appreciated that there are a variety of limitations associated with such systems. Among other things, the present invention considers a) that it can be difficult to install a CB radio into such a system (which has limited manual manipulation room for the strap 15 , the power connectors, etc.), b) that a substantial number of components (e.g., including mounting brackets, etc.) are required in such a system, and c) that a substantial number of components parts and associated costs are required to manufacture such a system. Thus, there has been a need to improve such systems to overcome one or more of the above and/or other limitations therein.
[0007] In addition to the foregoing background art, a variety of other systems and devices are also known. By way of example, additional background documents include:
a) U.S. Pat. No. 4,888,072, which shows an overhead “accessory support device for [a] vehicle windshield and [a] method of installing;” b) U.S. Pat. No. 4,818,010, which shows an overhead “mounting system for equipment in police vehicles;” c) U.S. Pat. No. 4,717,193, which shows an overhead “shelf for a vehicle cab;” d) U.S. Pat. No. 4,421,190, which shows an “overhead instrument console;” e) U.S. Pat. No. 4,226,460, which shows an overhead “long-distance truck cabin;” and f) U.S. Pat. No. 4,079,987, which shows an overhead “container system for entertainment and communications equipment.”
[0014] As set forth below, the preferred embodiments of the present invention provide notable advancements over those described in the documents outlined as well as other existing systems and devices.
SUMMARY
[0015] The preferred embodiments of the invention greatly improve upon existing systems and methods.
[0016] In some of the illustrative embodiments disclosed herein, an overhead storage unit is provided within a vehicle, such as, e.g., a truck. The storage unit can be used, e.g., to provide storage and/or for supporting an ancillary electronic device, such as, e.g., a CB radio in the vicinity of the operator. As described below, the preferred embodiments include a variety of features having a variety of advantages and/or benefits over existing systems. In some illustrative embodiments, some or all of the following advantages can be achieved over existing systems: 1) consolidation of parts; 2) reduction of costs; 3) improved electronic device mounting structure; 4) ease of use (e.g., freedom for fingers and phalange flexibility); 5) ease of upgrading and/or option changes; and 6) improved electronic-device-storage embodiments.
[0017] According to some embodiments, an ancillary electronic device storage assembly for a vehicle is provided that includes: a base configured to support an electronic device; a retaining mechanism configured to span over the electronic device when supported on the base; a moving mechanism configured to move the retaining mechanism against and retain the electronic device; the moving mechanism having a manually driven element that is accessed from an exterior of the storage assembly; whereby the retaining mechanism can move against and retain the electronic device by forces imparted manually by a user while the user's hands are located externally to the storage assembly. In some embodiments, the storage assembly is an overhead storage unit. Preferably, the manually driven element is accessed from below the overhead storage unit. In some preferred embodiments, the electronic device is a CB radio. In some embodiments, the moving mechanism is a screw drive mechanism, and the manually driven element is a head of a screw that can be manually driven with a screw driver.
[0018] According to some other embodiments of the invention, an ancillary electronic device assembly for a vehicle is provided that includes: a base configured to support the electronic device; a channel along an upper surface of the base configured to receive wiring of the electronic device; a well proximate a front side of the base into which the channel extends; and at least one electrical connector within the well for electrically connecting the wiring of the electronic device. In some embodiments, the electronic connector is a power connector. Preferably, the base is mounted upon a storage unit having at least one additional storage area, or, more preferably, is mounted upon a storage unit having a plurality of additional storage areas.
[0019] According to some other embodiments, an assembly for providing a multi-option overhead storage unit for a vehicle which includes: a single integrally molded storage unit: the storage unit being configured to be mounted proximate a juncture between a ceiling of a vehicle and a front windshield of the vehicle, and the storage unit being sized so as to span across substantially the entire lateral width of the windshield; the storage unit including a plurality of storage compartments located laterally along the storage unit; and at least one of the storage compartments being configured to receive an ancillary electronic device supported on an electronic device support; and an ancillary electronic device support that is mountable within the at least one of the storage compartments; whereby the ancillary electronic device support can be omitted from the storage unit to provide a first option without a supported electronic device, and can be mounted within the at least one of the storage compartments to provide a second option with a supported electronic device. In some embodiments, the storage unit includes a plurality of mounting members, wherein the mounting members are adapted to accommodate headliner mounting locations in a plurality of vehicles having different headliner mounting locations. In some embodiments, the storage unit is configured to be mounted within the plurality of vehicles without additional brackets between the storage unit and the headliners.
[0020] According to some other embodiments, an overhead storage unit for a vehicle is provided that includes: a plurality of compartments, the compartments having openings through which a user can access the compartments; a removable electronics components support plate configured to be located over at least one of the openings, the electronics components support plate including at least one of a microphone mount, a plurality of switches, and a power source.
[0021] According to some other embodiments, a vehicle having a manufacturer supplied CB radio microphone support is provided that includes: removable manufacturer supplied support plate mounted upon a storage unit of the vehicle; a manufacturer supplied microphone support integrally formed in the support plate; and a CB radio microphone supported on the microphone support.
[0022] The above and/or other aspects, features and/or advantages of various embodiments will be further appreciated in view of the following description in conjunction with the accompanying figures. Various embodiments can include and/or exclude different aspects, features and/or advantages where applicable. In addition, various embodiments can combine one or more aspect or feature of other embodiments where applicable. The descriptions of aspects, features and/or advantages of particular embodiments should not be construed as limiting other embodiments or the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The preferred embodiments of the present invention are shown by way of example, and not limitation, in the accompanying figures, in which like reference numerals indicate like or similar parts, and in which:
[0024] FIG. 1 is a side view of an illustrative storage unit within a vehicle in an illustrative overhead position to a vehicle operator;
[0025] FIG. 2(A) is a bottom front perspective view of an embodiment of a storage unit along with an ancillary electronic device (such as, e.g., a CB radio) and with an electronics component support plate (such as, e.g., for supporting switches or the like);
[0026] FIG. 2(B) is a top rear perspective view of the embodiment shown in FIG. 2(A) ;
[0027] FIG. 2(C) is a bottom front perspective view of an embodiment similar to that shown in FIG. 2(A) without an added ancillary electronic device (such as, e.g., a CB radio) and without an added electronics component support plate (such as, e.g., for supporting switches or the like);
[0028] FIG. 3(A) is a front top perspective view of certain components of an illustrative support device having a retaining mechanism depicted in a displaced position for explanatory purposes;
[0029] FIG. 3(B) is a front top perspective view of certain components of an illustrative support device like that shown in FIG. 3(A) , and with a retaining mechanism depicted in an adjacent position for explanatory purposes;
[0030] FIG. 3(C) is a bottom front perspective view of certain components of an illustrative support device similar to that shown in FIG. 3(A) according to some preferred embodiments;
[0031] FIG. 3(D) is a top rear perspective view of certain components of an illustrative support device similar to that shown in FIG. 3(A) according to some preferred embodiments;
[0032] FIG. 3(E) is a top front perspective view of a CB radio mounted upon an illustrative support device similar to that shown in FIG. 3(A) according to some preferred embodiments;
[0033] FIG. 4 is a partial bottom view depicting a storage unit in the vicinity of a CB radio similar to that shown in FIG. 3(A) according to some preferred embodiments;
[0034] FIG. 5(A) is a bottom perspective view of an embodiment of a storage unit similar to that shown in FIG. 2 , which includes an ancillary electronic device and an electronics component support plate;
[0035] FIG. 5(B) is a top rear perspective view of the embodiment shown in FIG. 5(A) ;
[0036] FIG. 5(C) is a perspective view of an illustrative mounting structure that receives a hanging element of a microphone;
[0037] FIG. 6 is a diagram schematically depicting a bottom view of a storage unit 210 mounted upon a headliner or ceiling within a vehicle; and
[0038] FIG. 7 is a top perspective view of another system of the present assignee over which the present invention improves upon.
DETAILED DESCRIPTION
[0039] While the present invention may be embodied in many different forms, a number of illustrative embodiments are described herein with the understanding that the present disclosure is to be considered as providing examples of the principles of the invention and that such examples are not intended to limit the invention to preferred embodiments described herein and/or illustrated herein.
1. General
[0040] With reference to FIG. 1 , an illustrative embodiment of an overhead storage unit 110 is shown within a vehicle, such as, e.g., a truck 140 . The storage unit 110 can be used, e.g., to provide storage and/or for supporting an ancillary electronic device, such as, e.g., a CB radio 120 in the vicinity of the operator 130 . Preferably, the electronic device is located in an ergonomically desirable position, such as in the illustrative example shown in FIG. 1 . As described below, the preferred embodiments include a variety of features having a variety of advantages and/or benefits over existing systems. In some illustrative embodiments, some or all of the following advantages can be achieved over existing systems.
[0000] a. Consolidation of Parts
[0041] In the preferred embodiments, a storage unit 110 is provided that greatly limits the amount of materials and component parts. By way of example, in the preferred embodiments, the storage unit 110 can include, e.g., a) a single unitary unit configured to span across of width of the vehicle, b) a unit that is mounted without the use of additional brackets required in existing systems (such as, e.g., employing reinforcing ribs to structurally enhance the storage unit itself, employing mounting hole positions arranged to match headliners of plural vehicles and/or the like), d) an elimination of rigid door structures by implementing, e.g., nets, fabrics and/or the like.
[0000] b. Reduction of Costs
[0042] In the preferred embodiments, a storage unit 110 is provided that can reduce costs considerably over existing systems.
[0000] c. Improved Electronic Device Mounting Structure
[0043] In the preferred embodiments, a storage unit 110 is provided that includes an electronic device mounting structure having substantial advantages and benefits over existing systems.
[0000] d. Ease of Use (e.g., Freedom For Fingers and Phalangeal Motion)
[0044] In the preferred embodiments, a storage unit 110 is provided upon which, e.g., an electronic device can be easily manually installed by an individual, without space restrictions that may otherwise impede freedom of movement as in existing devices.
[0000] e. Ease of Upgrading and/or Option Changes
[0045] In the preferred embodiments, a storage unit 110 is provided that can be readily adapted to different installations options. For example, in some embodiments, a storage unit 110 is provided that can be readily marketed in a first option as a storage unit without an ancillary-electronic-device (e.g., storage-only) or, alternately, in a second option as an ancillary-electronic-device(s) (e.g., CB radio and/or other devices) supporting storage unit.
2. Electronic-Device-Storage Embodiments
[0046] FIGS. 2(A) and 2(B) show an illustrative embodiment of a storage unit 210 which includes at least one storage area(s) and at least one mounting structure for an ancillary-electronic-device 220 .
[0047] As shown, the storage unit 210 preferably has a length in a lateral direction L such that it extends across substantially the entire width of a vehicle (such as, e.g., a truck 140 as shown in FIG. 1 ) between left and right sides of the vehicle. In this regard, the length of the storage unit 210 in the lateral direction L is preferably approximately the same as that of the front windshield 150 shown in FIG. 1 . In addition, as depicted in FIG. 1 , the storage unit 210 is preferably configured so as to be located predominantly above the operator's field of view through the front windshield 150 .
[0048] In some preferred embodiments, the storage unit 210 is formed from an integral unitary piece of material (such as, e.g., from an injection molded elastomeric or plastic material and/or any other suitable material). In some preferred constructions, the storage unit 210 includes at least a front wall 211 and a bottom wall 212 . In some preferred embodiments, the upper end of the front wall 211 includes mounting members 211 M located to facilitate mounting directly to the roof of the vehicle (such as, e.g., shown in FIG. 1 ) without intermediate brackets structures or the like. In addition, the storage unit 210 can also include left and right lateral side walls 213 L and 213 R, respectively. As depicted, the upper edges 213 UE of the left and right lateral side walls 213 L and 213 R are preferably contoured to follow the contour of the vehicle ceiling in some embodiments.
[0049] In some embodiments, as illustrated, the bottom wall 212 can include other elements mounted thereon, such as, e.g., sun visors 212 V and/or other elements (such as, e.g., lights, electronic-devices, radar detectors, etc.). In embodiments having visors 212 V mounted thereto, such visors 212 V can be mounted, e.g., to pivot from an underside of the bottom wall 212 , such as, e.g., about hinges 212 HI. The hinges 212 HI can, in some instances, be mounted so as to pivot from a rearward side of the bottom wall 212 (such as, e.g., shown at the left or driver's side of the storage unit 210 ) and/or from a forward side of the bottom wall 212 (such as, e.g., shown at the right or passenger's side of the storage unit 210 ).
[0050] In some preferred embodiments, as shown, the front wall 211 includes a plurality of storage openings 230 through which personal items and/or the like for the vehicle operator or user can be placed for storage. In the illustrative embodiment shown in FIGS. 2(A) and 2(B) , the storage openings include three storage openings 230 A, 230 B and 230 C. However, in other embodiments, the storage unit 210 can include any number of openings, such as, e.g., from one opening to any number of desired openings.
[0051] In some preferred embodiments, as shown in FIG. 2(A) , the storage unit 210 also includes a plurality of other storage openings 230 D and 230 E that are used for pre-mounting vehicular items. In particular, in the preferred embodiments, the opening 230 E is configured to receive an ancillary-electronic-device, such as, e.g., a CB radio 220 , and the opening 230 D is configured to receive an electronics-components-support structure, such as, e.g., an electronics-components-support-plate 240 .
[0052] As shown in FIG. 2(B) , and as discussed further below, with reference to FIGS. 3(A)-3(E) , the CB radio 220 , or the like, is preferably mounted upon the support unit 210 via an electronic-device-support 250 (including, e.g., a support platform) and a retaining mechanism 260 (including, e.g., a clamping member, such as, e.g., a rigid element, such as, e.g., a beam, and/or a flexible element, such as, e.g., a strap). In the preferred embodiments, however, the retaining mechanism is configured to retain the CB radio 220 or the like by the application of a manual force external to the support unit 220 such as to, e.g., effect movement of the retaining mechanism 260 by easy access external to the storage unit 210 . See, e.g., arrow AA shown in FIG. 1 representing an illustrative point of external access in some illustrative embodiments.
[0053] Preferably, the storage openings 230 A, 230 B and/or 230 C, which have no pre-mounted vehicular items therein, can be used by a vehicle operator or the like to freely store items therein as desired. In some preferred embodiments, rather than utilizing, e.g., rigid doors to cover the front of these openings 230 A, 230 B and/or 230 C, these openings are at least partly covered with a retaining-netting 230 RN that is stretched across these openings. In some embodiments, the netting can be replaced with a retaining fabric (see, e.g., retaining fabric 230 RF shown in FIGS. 5(A) and 5(B) ) or another flexible material. Or, alternatively, one or more of the openings can either remain uncovered or can be provided with a rigidly attached door or the like. As illustrated in FIG. 2(A) , the retaining netting preferably extends upwardly a vertical height that is sufficient to retain items within compartments behind the openings, while providing a sufficient depth d to allow a user to freely pass their hands through the opening to grasp items stored thereon and/or to place items thereon. In the preferred embodiments, the upper edge of the retaining-netting 230 RN is supported upon an elastic wire or string 230 EL. The retaining netting 230 RN can be mounted to the storage unit 210 using a variety of mounting mechanisms, such as, e.g., rivets, screws, clamps and/or tying the netting to mounts on the storage unit.
[0054] As shown in FIG. 2(B) , in some preferred embodiments, the storage unit 210 includes a plurality of divider elements 270 distributed at one or more position, preferably at a plurality of positions, along the lateral length L of the unit. In the illustrative example, three divider elements 270 are implemented. In some examples, the divider elements could be integrally formed with the storage unit 220 (such as, e.g., by forming the unit 210 and the divider elements 270 together in the same injection molding process). In other examples, the divider elements could be removably attachable to the unit 210 , such as, e.g., by inserting the elements into respective receiving slots and/or otherwise mounting the divider elements to the unit 210 . Among other things, the employment of insertable divider elements 270 can enable the elements to be added and/or removed as desired; for example, to accommodate larger items, in some examples a removable divider element 270 could be either omitted in the original installation by the manufacturer or removed by a consumer or user after purchase of the vehicle.
3. Limited Use (e.g., Storage Only) Embodiments
[0055] FIG. 2(C) shows another embodiment of the invention in which a storage unit 210 similar to that shown in FIGS. 2(A) and 2(B) is implemented without an electronics-components-support-plate 240 and without an ancillary electronic device, such as, e.g., a CB radio 220 . Accordingly, in this illustrative embodiment, the storage unit 210 can be used to provide a plurality of convenient storage compartments. It should be appreciated based on this disclosure that this embodiment can be substantially similar to and can be modified in a like manner to the embodiment shown in FIGS. 2(A) and 2(B) . By way of example, all of the various other features described above but not shown in FIG. 2(C) can be employed herein, such as, e.g., divider elements 270 , mounting elements 211 M, etc. In addition, as in the foregoing embodiment shown in FIGS. 2(A) and 2(B) , the number of openings 230 can be modified between different embodiments.
[0056] In some preferred embodiments, at least some of the same component parts can be used to provide a first storage unit option that is similar to that shown in FIG. 2(C) and to provide a second storage unit option that is similar to that shown in FIGS. 2(A) and 2(B) . In this manner, by way of example, a manufacturer can utilize the same or similar parts to manufacture both options, with the exception that, e.g., in the second storage unit option, one or more of the electronics-components-support-plate 240 and/or the ancillary-electronics-device 220 can be provided.
4. Illustrative Electronic Device Mounting Structures
[0057] FIGS. 3(A) to 3(E) show some preferred embodiments depicting an illustrative electronic device support 250 and an illustrative corresponding retaining mechanism 260 . In this regard, as shown in FIG. 3(A) , in some embodiments, the electronic device support 250 can include, e.g., a base wall 251 upon which an electronic device can be supported. As also shown in FIG. 3(A) , in some embodiments, the support 250 can include left and right side walls 252 L and 252 R. In some embodiments, at least one of the sidewalls, such as, e.g., the side wall 252 L can include an integrally formed (e.g., integrally molded) mount 252 M, such as, e.g., an upwardly extending hook-shaped member (e.g., or clip) as shown for receiving wiring of the electronic device and/or the like.
[0058] In the preferred embodiments, the base wall 251 includes a number of advantageous features, such as, e.g., one or more, preferably all of the following features in the preferred embodiments.
[0059] First, the base wall 251 preferably includes a large array of through-holes 251 H. Preferably, these through-holes 251 H are sufficient to allow an electronic device that allow for the passage of acoustic sounds to and/or from the electronic device (such as, e.g., via a speaker, which in, e.g., a CB radio is often mounted on a bottom surface of the CB radio) so as to freely transmit and/or receive sound therethrough. With reference to FIG. 4 , when mounted within the storage unit 210 , the through-holes 251 H preferably align with an array of through-holes 212 HH formed in the bottom wall 212 of the storage unit 210 . In the preferred embodiments, as shown, the through-holes 212 HH are located within a forward protrusion section 211 FP of the front wall 211 .
[0060] Second, with reference to FIGS. 3(A) and 3(B) , during placement of the support 250 upon the storage unit 210 , downward projections 251 DP preferably are received within respective receptacles (not shown) such as to readily align the support 250 with respect to the storage unit 210 structure. In some illustrative and non-limiting embodiments, the downward projections 251 DP and the receptacles can include connection mechanisms (such as, e.g., snap-fit members, press-fit members, clamps, bolts and/or the like) to facilitate retention of the support 250 upon the storage unit 210 once assembled thereon. By way of example, one or more of the projections 251 DP can include a projecting pin 251 P that can be press-fit into a resilient press-fit retaining washer 251 R that is fixed in relation to the support unit receptacles (not shown). In some preferred embodiments, the members 251 P can be screws that are screwed into the support unit.
[0061] Third, the support 250 preferably also includes a variety of elements to facilitate usage and management of electronic device wiring, cables and/or the like. In this regard, the support 250 preferably includes at least one, preferably all, of the following features.
[0062] a. A channel 251 S for receiving wiring, cables and/or the like of the electronic device 220 mounted thereon, such as, e.g., in preferred embodiments a CB radio wiring harness. In this regard, often CB radios and other electronic devices include wires that extend from a rear of the device 220 , such as, e.g., shown in dashed lines at reference number W in FIG. 3(D) . In preferred embodiments, the channel 251 S is adapted to extend from proximate a rear of the support 250 toward a front side of the support 250 where a user can more easily and/or more ergonomically access the wiring. As shown in FIGS. 3(A) and 3(B) , the channel 251 S can also include one or more, preferably a plurality, of overhanging tang members 251 T which can help to retain wiring within the channel 251 S after it is manipulated therein. It is contemplated, however, that in some embodiments, in which wiring may extend from a side of the device, a channel 251 S could extend along a different path as long as it is directed to a well region 251 W as discussed below.
[0063] b. A well region 251 W formed proximate a front of the support 250 . In use, an installer, a customer or the like can manipulate flexible wiring of a CB radio or the like so as to be situated within the channel 251 S and to rest upon the base 251 as shown in FIG. 3(D) . As shown in FIG. 3(E) , a forward end of the wiring can be connected at, e.g., Wa and Wb, respectively, to the power connectors PC 1 and PC 2 which are conveniently located within the well 251 W proximate a front side of the support 250 . While any known type of electrical connector can be employed, in some illustrative embodiments, the connectors PC 1 and PC 2 include rotatable connector members (such as, e.g., employing two threadingly engaged clamping members) that can be conveniently rotated clockwise or counter clockwise around axes generally parallel to a front face of the CB radio or the like. In this manner, the power connectors PC 1 and PC 2 can be easily and ergonomically grasped and manipulated (e.g., rotated with one's fingers) within the well 251 W. Here, the size and depth of the well is preferably configured to provide appreciable user freedom of movement (e.g., freedom for fingers and phalanges)
[0064] c. One or a plurality of integrally formed, e.g., molded-in, mounts (such as, e.g., two in the illustrated embodiments), such as, e.g., clips 251 CL, for CB-radio connectors. In the preferred embodiments, these integrally formed mounts, e.g., clips 251 CL, will enable the electrical harness to be readily secured at a proper location without the need for additional hardware. In this regard, as described above, it is also noted that the support 250 can also include one or more integrally formed mount 252 M, such as, e.g., an upwardly extending hook-shaped member (e.g., clip) for receiving wiring of the electronic device and/or the like, such as, e.g., shown in FIGS. 3(A) and 3(B) .
[0065] As indicated above, FIGS. 3(A) to 3(E) also show some preferred embodiments of a retaining mechanism 260 . In this regard, reference is made to FIG. 3(E) . As shown in FIG. 3(E) , in this illustrative embodiment, the retaining mechanism 260 includes an inverted generally U-shaped member 262 . In some preferred embodiments, the generally U-shaped member is a generally rigid member made with an elastomeric or plastic material. In some illustrative embodiments, as with the support 250 and the storage unit 210 , the generally U-shaped member 262 can be made as an injection molded element. In some preferred embodiments, the retaining mechanism is normally biased upwardly, such as, e.g., by using a spring. In this manner, a user can freely locate a CB radio or the like beneath the generally U-shaped member 262 while the springs bias the member upwardly. Preferably, the retaining mechanism 260 is movably mounted via a movement mechanism 264 so that it can be moved (e.g., drawn) downward so as to impinge against the surface of the CB radio or the like so as to retain the device. In this regard, any appropriate movement mechanism 264 can be employed in various embodiments, such as, e.g., a threaded screw shaft assembly, a cam mechanism, a pulley structure, a flexible strap or lanyard, a motor and/or the like.
[0066] In an illustrative preferred embodiment, screws 267 , the heads of which are seen in FIG. 4 , extend through through-holes 251 RH, shown in, e.g., FIG. 3(C) , within the base 251 of the support 250 in such a manner that heads of the screws will not pass there-through. Then, the threaded ends of the screws 267 are threaded into a threaded element 265 fixed to, and integrally formed with, the generally U-shaped member 262 . Moreover, as illustrated in FIG. 4 , the bottom wall 212 of the storage unit 210 preferably includes through-holes 212 H via which the screws 267 can be readily accessed for tightening and/or loosening from a user access position external to the storage unit 210 (e.g., from beneath the storage unit 210 in this illustrative example). Preferably, this external user access can be made with a minimal amount of access room for manipulation inside the storage unit 210 in order to achieve mounting of the CB radio or the like. By way of example, the diameter of the through-holes 212 H can be significantly less than a minimum size required for manual access, such as, e.g., being less than an inch in diameter, or even less than one half of an inch in diameter, or even substantially less in some embodiments.
[0067] As a result, in order to mount a CB radio or another electronic device on the support 250 , the generally U-shaped member 262 can be clamped against the device, such as, e.g., shown in FIG. 3(D) . Preferably, as shown in FIGS. 3(C) and 3(E) , a bottom side of the member 262 is generally flat so as to apply a generally consistent force against the electronic device. In addition, preferably, the bottom side of the member 262 includes a thin foam pad attached thereto (such as, e.g., having a thickness of a few millimeters) so as to enhance gripping of the CB radio or the like, to distribute forces and/or the like. As shown in FIG. 3(D) , in some preferred embodiments, the member 262 can be formed with one or more, preferably a plurality of reinforcing ribs 262 to enhance the strength and rigidity of the member.
[0068] Referring once again to FIG. 3(A) , in some illustrative and non-limiting embodiments, the member 262 is configured such that a maximum width or span s 1 is between about 180 and 270 millimeters, or, more preferably, between about 200 and 250 millimeters, or, more preferably, between about 220 and 230 millimeters, or, more preferably, about 226 millimeters. In addition, in some illustrative and non-limiting embodiments, the member 260 is movably supported, such as, e.g., via a movement mechanism 264 , so as to have a maximum height (such as, e.g., in a fully outwardly biased state) from a bottom of the member 262 to the surface of the base 251 of between about 60 to 80 millimeters, or, more preferably, about 70 millimeters, and so as to have a minimum height from a bottom of the member 262 to the surface of the base 251 of between about 40 to 50 millimeters, or, more preferably, about 46 millimeters. In some illustrative and non-limiting embodiments, the devices shown in FIGS. 2(A) to 5(B) are depicted as to scale and proportional in size, such that some illustrative sizes and proportions can be understood based upon a comparison of the figures and the illustrative dimensions identified above in this paragraph.
5. Illustrative Electronics-Components-Support-Plate Structures
[0069] As discussed above, and as best shown in FIGS. 2(A) and 5(A) , in some preferred embodiments a storage unit 210 is adapted so as to include an electronics-components-support structure, such as, e.g., an electronics-components-support-plate 240 .
[0070] In some preferred embodiments, the electronics-components-support-plate 240 preferably includes a plurality of switches 240 S. Although FIGS. 2(A) and 5(A) depict illustrative embodiments having 4 switches, it is contemplated that in various embodiments one or more switches can be provided. In a various embodiments, the switches can enable an increased level of versatility, and can be employed by a manufacturer, an owner of the vehicle and/or an operator of the vehicle to provide desired functionality based on existing electrical needs, etc.
[0071] In some preferred embodiments, the electronics-components-support-plate 240 preferably includes an electrical outlet (not shown, but which can be, e.g., located at opening 240 E) for electrical power supply. In some embodiments, the electrical outlet can be adapted to function as a 24 Volt electrical outlet, as a 12 Volt electrical outlet and/or as another desired electrical outlet. In a various embodiments, the provision of an electrical outlet can similarly provide an increased level of versatility.
[0072] In some preferred embodiments, electronics-components-support-plate 240 includes an fixedly attached or integrally formed mounted mounting structure 240 MK, which is adapted for receiving a hanging element HM of a microphone (such as, e.g., the microphone M shown in FIG. 1 ). With the provision of such a hanging element, a CB radio or the like can readily be mounted within the vehicle in a simplistic manner without the need for the addition of unsightly or crude microphone supports by a consumer. Among other things, by providing the hanging element HM as formed as part of a component of the vehicle, a higher level of aesthetic quality and craftsmanship can be achieved, additional convenience can be achieved, and increased utility can be achieved. Moreover, by providing the hanging element HM in a manner that it can be readily added to and/or removed from the storage unit, a higher level of versatility and a wider range of user options can be achieved.
[0073] The manner in which the electronics-components-support-plate 240 is mounted upon the storage unit 210 can vary depending on circumstances. By way of example, in some embodiments, a lower end of the plate 240 can be received in a slot (not shown) and the upper end can be pivoted into position. Then, the mounting members 211 M (e.g., which can include, for example, screws or the like) can be used to retain the upper end of the plate 240 in position. In some embodiments (as shown in FIG. 5 (B)), the same screws that are used to support the upper end of the plate 240 can also be used to mount the storage unit 210 upon the headliner of a vehicle (e.g., by attachment directly to the headliner).
[0074] In addition to the foregoing electronics components that can be supported on the electronics-components-support-plate 240 , in various other embodiments a variety of other electronics components can be supported thereon based on circumstances.
6. Illustrative Vehicle Ceiling and/or Headliner Mounting Structures
[0075] As discussed above, in existing systems of the present assignee, as depicted in FIG. 7 , an overhead storage unit 10 required the implementation of mounting brackets BK (shown in dashed lines) which were used to mount the storage unit to a headliner of the vehicle. As shown in FIG. 7 , the bracket BK includes two illustrative bolts B that pass through mounting bracket BK so as to retain the bracket to the headliner. In turn, the mounting bracket, which is fixed to the storage unit, thus, supports the storage unit indirectly from the headliner.
[0076] On the other hand, according to some preferred embodiments of the invention, such additional mounting brackets are eliminated. Accordingly, the storage unit 210 according to these preferred embodiments can be directly mounted to the headliner. In this regard, as shown in FIG. 5(B) , the upwardly projecting screws at the mounting member locations 211 M can be directly screwed into the headliner.
[0077] In order to facilitate such direct attachment without the use of added bracket structures (i.e., since such bracket structures are typically made of metal and provide a higher strength and rigidity), the storage unit 210 is preferably modified to include strength enhanced edges, so as to facilitate such attachment. By way of example, as shown in FIG. 5(B) , in some embodiments the upper end of the front wall 211 preferably includes a widened strengthening element 280 that is integrally and unitarily formed with the storage unit 210 . By way of example, the strengthening element 280 can include, e.g., as shown, an overhanging wall having a plurality of reinforcing ribs 281 distributed there-over. In the preferred embodiments, the strengthening element 280 extends substantially along the length of the storage unit and extends between and connects the respective mounting member locations 211 M as shown.
[0078] In addition, in some preferred embodiments as shown in FIG. 5(A) , a plurality of caps or cover elements CP can be mounted (e.g., snap fit, or press fit) over the respective screw locations corresponding to mounting member locations 211 M. Accordingly, in order to mount the storage unit within a vehicle, the caps CP can be removed, the unit can be screwed into place, and then the caps CP can be added. In this manner, the storage unit can be readily attached without costly, complex and bulky bracket members, and while the storage unit is, hence, itself screwed to the headliner in some preferred embodiments, the screws for such an attachment are kept from view and an increased level of aesthetic appeal and refinement can be achieved.
[0079] In order to maintain a high quality aesthetic appearance, it is helpful to avoid unnecessary exposure of screws, connectors or the like. In addition to the use of caps CP, which help to obscure unsightly screws, it is noteworthy that the screws 267 (shown in FIG. 4 ) which remain uncovered in some preferred embodiments (e.g., to facilitate easy opening and closing of the moving mechanism 264 via the use of, e.g., an ordinary screw-driver by the owner or user) are, while uncovered, effectively obscured from view. First, the screw located in the array of holes 212 HH, is located within a similarly shaped hole 212 H in such a manner as to camouflage the screws presence. Second, the other of the two screws is located underneath the visor 212 V, such that, for the most part, the second screw is similarly obstructed from view.
[0080] In prior overhead storage systems, there have typically been additional complexities and costs that arise due to the implementation of such overhead storage systems in a plurality of vehicle models, having a plurality of internal structures, and, including a variety of headliner structures. Previously, different parts were required to be used for different vehicles and different headliner structures. This previously lead to increased complexities and increased costs. Accordingly, in some of the preferred embodiments herein, the mounting structure is specifically designed so as to accommodate a variety of vehicles, such as, e.g., by accommodating a variety of headliner structures.
[0081] By way of example, in some illustrative embodiments, with reference to FIGS. 5(A) and 5(B) , the multiple mounting member locations 211 M are preferably selected upon initial design and manufacture to correspond to the headliner structure of a plurality of vehicles (such as, e.g., a whole line of vehicles, which can include, e.g., two, five, ten or more vehicles). By way of example, in mounting the storage unit 210 into certain vehicles one or more of the mounting members 211 M may be extraneous and, hence, not utilized depending on the headliner structure of that vehicle. For example, FIG. 6 is a schematic diagram depicting an upward view of the bottom of a storage unit 210 as mounted upon the headliner 290 . By way of example, consider that one vehicle may have mounting locations corresponding to positions A 1 , A 2 and A 4 , while another vehicle may have mounting locations corresponding to positions A 1 , A 3 and A 4 . Accordingly, in the preferred embodiments, the storage unit 210 is modified so as to include appropriate mounting locations for a plurality of vehicles. In this manner, a substantial reduction in parts and cost savings can be realized. Moreover, in some embodiments, the mounting members 211 M can include through-holes for receiving screws that are screwed into the headliner. In some cases, to provide increased versatility in the applicability of the storage unit 210 to different vehicles, at least some of the through-holes can be elongated in the lateral direction L an amount to accommodate variations between at least some of the vehicle mounting requirements (i.e., such that the screw attachment position can vary laterally to some extent within such through-holes).
BROAD SCOPE OF THE INVENTION
[0082] While illustrative embodiments of the invention have been described herein, the present invention is not limited to the various preferred embodiments described herein, but includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations and/or alterations as would be appreciated by those in the art based on the present disclosure. By way of example, while the detailed description and drawings depict an illustrative overhead storage unit, various aspects of the invention (such as, e.g., the improved electronic device mounting methods) can be employed within a wide variety of environments. In this regard, various features could, e.g., be implemented within dash boards of vehicles, consoles and/or at any other appropriate location as would be appreciated based on this disclosure.
[0083] The limitations in the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as non-exclusive. For example, in the present disclosure, the term “preferably” is non-exclusive and means “preferably, but not limited to.” In this disclosure and during the prosecution of this application, means-plus-function or step-plus-function limitations will only be employed where for a specific claim limitation all of the following conditions are present in that limitation: a) “means for” or “step for” is expressly recited; b) a corresponding function is expressly recited; and c) structure, material or acts that support that structure are not recited. In this disclosure and during the prosecution of this application, the terminology “present invention” or “invention” may be used as a reference to one or more aspect within the present disclosure. The language present invention or invention should not be improperly interpreted as an identification of criticality, should not be improperly interpreted as applying across all aspects or embodiments (i.e., it should be understood that the present invention has a number of aspects and embodiments), and should not be improperly interpreted as limiting the scope of the application or claims. In this disclosure and during the prosecution of this application, the terminology “embodiment” can be used to describe any aspect, feature, process or step, any combination thereof, and/or any portion thereof, etc. In some examples, various embodiments may include overlapping features. In this disclosure, the following abbreviated terminology may be employed: “e.g.” which means “for example.” | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a proximity detector for detecting the proximity of a substrate by a change of electrostatic capacity.
2. Description of the Prior Arts
A proximity detector is disposed at the front edge of a door such as an elevator so as to detect an obstacle, in the way of movement of the door during the time of shutting the door or at the full opening of the door under a non-contact condition whereby the movement of the door is reversed or the operation of the movement of the door is stopped.
The conventional proximity detector has the structure shown in FIG. 1.
In FIG. 1, the reference numerals (1) and (2) respectively designate antennae disposed at the front side of the door and (3) and (4 respectively designate earth electrostatic capacities of the antennae (1), (2); (5) designates a shield plate which is insulated from the antennae (1), (2); (6) and (7) respectively designate electrostatic capacities between the antennae (1), (2) and the shield plates (5). The electrostatic capacities (3), (4), (6), (7) form an impedance bridge. The reference numeral (8) designates a AC power source; (9) designates a transformer for detecting the unbalance of the bridge; (10) designates an AC amplification circuit for amplifying the unbalanced voltage of the bridge applied to the transformer (9). The reference numeral (11) designates a rectifying circuit; (12) designates a DC amplification circuit for amplifying the output of the rectifying circuit (11); (13) designates an output relay; (14) designates an antenna cover for protecting the antennae (1), (2) disposed at the front side of the door and D designates a non-sensitive part.
Normally, the bridge circuit is balanced to zero the output of the transformer (9). When a body or a substrate approaches the antenna (1), only the earth electrostatic capacity (3) of the antenna (1) is changed whereby the impedance bridge becomes unbalanced and an output voltage which is proportional to the unbalanced value is produced in the transformer (9). The output is amplified by the AC amplification circuit (10) and it is converted to DC current by the rectifying circuit (11) and the output is amplified by the DC amplification circuit (12) to drive the relay (13). The relay (13) stops the movement of shutting the door or reverses movement of the door so as to prevent the catching of a body or a substrate in the door.
In the conventional proximity detector having the bridge structure, changes in the electrostatic capacities in the same phase mode for both of the electrostatic capacities (3), (4) of the antennas (1), (2) cancel each other in the bridge circuit, whereby the erroneous operation caused by the swinging of the door during the operation of shutting the door can be eliminated and high detecting sensitivity can be attained. On the other hand, when one's hand is caused to touch the antenna cover (14) at the full opening condition of the door to prevent the initiation of the shutting operation of the door, the following disadvantages are caused.
(a) When one's hand is caused to touch the antenna cover (14) at the nonsensitive zone D in the boundary between the antenna (1) and the antenna (2), the bridge is balanced so as not to generate the bridge output whereby the shutting operation of the door cannot be prevented.
(b) When the hand of one person is caused to touch the antenna cover (14) over the antenna (1), and a hand of another person is caused to touch the antenna cover (14) over the antenna (2), the bridge is balanced whereby the shutting operation of the door cannot be prevented.
In order to eliminate the non-sensitive zone D causing the above-mentioned trouble, it can be considered that the antennas (1), (2) are further divided to form a plurality of bridge circuits by combining the divided antennae. However, the structure of such a device is complicated.
It is difficult to overcome the disadvantages of (2) by the modification of the bridge structure in principle.
SUMMARY OF THE INVENTION
It is an object of the present invention to improve the above-mentioned disadvantage and to provide a proximity detector having a simple structure and high stability without impairing the high detecting sensitivity produced by the bridge structure.
The foregoing and other objects of the present invention have been attained by providing a proximity detector comprising a pair of antennas disposed at the front edge of a door with a space; and voltage converters for converting earth electrostatic capacities of the antennas to the corresponding voltages. The low proximity detector further includes a first detecting circuit for detecting a differential signal of the outputs of the voltage converters; and a second detecting circuit for detecting a summing signal of the outputs of the voltage converters. The movement of the door is controlled by the output of the first detecting circuit and/or the output of the second detecting circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block circuit diagram of the conventional proximity detector; and
FIG. 2 is a block circuit diagram of one embodiment of a proximity detector according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will be described by referring to FIG. 2.
In FIG. 2, the reference numerals (10a), (10b) respectively designate AC amplification circuits; (11a) to (11c) respectively designates rectifying circuits; (12) designates DC amplification circuit; (13) designates an output relay; (15) designates a differential amplification circuit; (16) designates a cumulative amplification circuit; (17) designates a pulse counter; (18) designates an OR circuit; (19a) designates a first detecting circuit; and (19b) designates a second detecting circuit.
An AC voltage given by shunting the voltage of the AC power source (8) by the electrostatic capacity (6) and the earth electrostatic capacity (3) of the antenna (1), is applied to the antenna (1). The AC voltage is rectified by the rectifying circuit (11a) to obtain the DC voltage (11aa). On the other hand, the AC voltage given by shunting the voltage of the AC power source (8) by the electrostatic capacity (7) and the earth electrostatic capacity (4) of the antenna (2), is applied to the antenna (2). The AC voltage is rectified by the rectifying circuit (11b) to obtain the DC voltage (11ba).
The DC voltages (11aa) (11ba) given by the rectifying circuits (11a), (11b) are subtracted and amplified by the differential amplification circuit (15) of the first detecting circuit (19a). The antenna (1) and the antenna (2) form a bridge from the viewpoint of the output of the differential amplification circuit (15).
The output of the differential amplification circuit (15) is zero in the case of the equation:
electrostatic capacity (3)×electrostatic capacity (7)=electrostatic capacity (4)×electrostatic capacity (6).
When the output of the differential amplifier circuit (15) has been changed in the positive direction by an increase in the earth electrostatic capacity (3) of the antenna (1) caused by proximity of a substrate to the antenna (1), the output of the differential amplification circuit (15) can be changed in the negative direction by proximity of a substrate to the antenna (2).
It is difficult to always maintain the balance of the electrostatic capacities (3), (4), (6), (7) because of variations of ambient temperature and humidity and adhesion of dust on the antenna cover (14), whereby the output of the differential amplification circuit (15) is not kept zero and it is not always constant.
In general, the change of the output of the differential amplification circuit (15) caused by the ambient temperature has a longer period in comparison with the change of the output of the differential amplification circuit (15) caused by proximity of a substrate to the antennas (1), (2). Accordingly, only the change of the output of the differential amplification circuit (15) caused by proximity of a substrate to the antennas (1), (2) is selectively amplified by the next AC amplification circuit (10a), whereby the effect of the ambient temperature is eliminated.
The polarity of the output of the AC amplification circuit (10a) caused by proximity of a substrate to the antenna (1) is different from that of proximity of a substrate to the antenna (2). Accordingly, it is rectified as the full-wave rectification by the next rectifying circuit (11c) and amplified by the DC amplification circuit (12) and passed through the OR circuit (18) to drive the relay (13).
The first detecting circuit (19a) attains non-contact detection of high sensitivity higher than that of the conventional proximity detector, by the combination of the differential amplification circuit (15), the AC amplification circuit (10a),, the rectifying circuit (11c) and the DC amplification circuit (12). On the other hand, in the cumulative (summing) amplification circuit (16) of the second detecting circuit (19b), the DC voltages (11aa), (11ba) obtained by the rectifying circuits (11a), (11b) are summed and amplified. The output of the cumulative amplification circuit (16) is decreased depending upon the increase of the earth electrostatic capacities (3), (4) of the antenna (1) and the antenna (2), and it is increased depending upon the decrease of the earth electrostatic capacities (3), (4) of the antenna (1) and the antenna (2). Accordingly, the antennae (1), (2) are considered to form one antenna from the viewpoint of the output of the cumulative amplification circuit (16).
In the case of a single antenna structure, the output of the cumulative amplification circuit (16) is changed because it is easily affected by the swinging of a door during the operation of shutting the door and the change of the earth electrostatic capacities (3), (4) of the antennas (1), (2) caused by the variation of ambient temperature and humidity. Accordingly, it is difficult to detect, with high sensitivity, the variations of the earth electrostatic capacities (3), (4) of the antennae (1), (2) from the output of the cumulative amplification circuit (16).
In the second detecting circuit (19b), only large changes in the earth electrostatic capacities of the antennas (1), (2) that is, the operation of touching or disengaging a hand from the antenna cover (14) is detected.
When a large change of the output of the cumulative amplification circuit (16) is given, for example, a hand is caused to touch the antenna cover (14), a touch pulse signal (10ba) is generated as the output of the AC amplification circuit (10b). When a hand is caused to disengage from the antenna cover (14), the disengage pulse signal (10bb) is generated as the output of the AC amplification circuit (10b).
The pulse counter (17) is usually set to zero for the datum. The pulse counter (17) is counted up by the touch pulse signal (10ba) of the AC amplification circuit (10b) to record the touching of the antenna cover (14). The output of the pulse counter (17) is passed through the OR circuit (18) to drive the relay (13).
When the pulse counter (17) is counted down to zero by the disengage pulse signal (10bb) of the AC amplification circuit (10b), the driving of the relay (13) by the output of the pulse counter (17) is stopped as there is no touching of the antenna cover (14). When a plurality of hands touch on the antenna cover (14), the driving of the relay (13) is continued until disengaging of the same number of hands occurs.
The relay (13) is driven by the logical sum of the highly sensitive detection by the first detecting circuit (19a) and the touch detection on the antenna cover (14) by the second detecting circuit (19b), whereby the door shutting operation is stopped or reversed so as to prevent the catching of a body or a substance in a door.
In the above-mentioned embodiment, there has been described the combination of only the electrostatic capacities as to convert the change of the earth electrostatic capacities (3), (4) of the antennas (1), (2) to a voltage variation. Thus, it is clear that the present invention can be applied to the case of converting the change of the earth electrostatic capacities (3), (4) of the antennas (1), (2) to the voltage variation by a other circuit systems.
In the above-mentioned embodiment, there has been described conversion of the the voltages given to the antennas (1), (2) to DC voltages by rectification. Thus, it is clear that the present invention can be applied to the case of applying the voltages given to the antennas (1), (2) directly to the differential amplification circuit (15) and the cumulative amplification circuit (16).
As described above, in accordance with the present invention, the earth electrostatic capacities of the divided antennas are respectively converted to corresponding voltages and the proximity of a substrate is detected by both a summing signal and the a subtracting signal. High sensitivity detection higher than that of the conventional bridge system can be attained and the non-sensitive zone to touching of the antenna cover can be eliminated and the erroneous operation caused by a plurality of touches on the antenna cover can be prevented. When the present invention is applied to an electric automatic door, the safety factor can be further improved. | 4y
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BACKGROUND OF THE INVENTION
The invention relates to a regenerative oxygen trap.
The necessity of being able to use certain gases having all traces of oxygen removed during chemical reactions has led to the manufacture of numerous traps of either the regenerating or non-regenerating type which are made mostly from metals or metal oxides selected subject to their chemical affinity for oxygen. However, the operation of this apparatus has many disadvantages which result partly from the reaction techniques brought into play or which are inherent in the chemical properties of the elements under consideration.
Metals currently in use include firstly titanium and zirconium which constitute excellent traps on account of their great affinity for oxygen, but which, when used in their original state, have the important disadvantage thay they rapidly lose their effectiveness. An oxide layer forms on the surface which hinders the fixation of oxygen without it being possible to detect easily the appearance of such superficial saturation.
Liquid magnesium is also a very effective oxygen trap, but has the disadvantage of introducing magnesium oxide into the purified gases.
Copper can also be used as a material for collecting oxygen. The traps which are provided with copper have the advantage of being regenerative through the action of hydrogen passing over the formed copper oxide. This system is not suitable for all applications as traces of hydrogen are still occluded in the copper after regeneration. These traces of hydrogen are subsequently found in the form of water vapour in the gas which is to be purified.
The object of the invention is to overcome the various aforementioned disadvantages and provide an oxygen trap whose effectiveness is ensured by a reaction for the rapid elimination of oxygen, the rate of which is substantially constant throughout the entire operation of the trap and can be easily controlled.
SUMMARY OF THE INVENTION
The oxygen trap according to the invention, which comprises a closed enclosure or enclave, means of admitting into this enclave a gas containing traces of oxygen to be eliminated and means for evacuating the purified gas from this enclave, is characterised in that it comprises, inside this enclave, a mass, preferably a block of material formed of a solid solution of metal oxides which imparts thereto an ionic conductivity through 0 2 - ions and a nonzero electrical conductivity, this mass being introduced into an electric circuit comprising a source of electricity such as a direct or rectified current generator.
If necessary, a furnace is associated with the trap as defined above in a case where the block must be raised to a sufficiently high temperature for the respectively aforementioned ionic and electrical conductivities to be manifested to any appreciable degree.
The aforementioned solid solutions are preferably formed of a "base oxide" having a valence number 4, such as zirconium dioxide ZrO 2 , thorium dioxide ThO 2 , or hafnium dioxide HfO 2 , and a "solute" formed of at least one oxide of a metal with a lower valency, such a syttrium oxide Y 2 O 3 , calcium oxide CaO, magnesium oxide MgO, or rare earths, such as oxides, for example, La 2 O 3 , Yb 2 O 3 , Sc 2 O 3 etc. The dissolving of the oxide with the lower valency in the oxide with the valence number 4 leads to the formation of a lattice having oxygen vacancies or unoccupied sites which impart to these solid solutions the property of conducting electric current in the form of 0 2 - oxide ions.
In addition the said solid solutions must contain an oxide or "electronic dope additive" which imparts thereto properties of electric conduction. This function is sometimes fulfilled by the base oxide and sometimes by the solute. Alternatively a metal oxide can be advantageously used, such as cerium oxide CeO 2 or one of several oxides of the transition metals. It will be noted that the oxide CeO 2 can also act as the base oxide, at least in those oxygen traps which are intended for relatively limited purification, in particular a degree of purification not exceeding that which would result in the purified gas having a partial oxygen pressure of less than 10.sup. -7 atmospheres. It is found that attempts to produce further purification result in the cerium metal tending to adopt the valence number 3, the resulting oxide therefore becoming a purely electric conductor.
Preferably the weight concentration of the solid in relation to the entire solid solution will be of the order of 5 to 20%, at least when the conditions for reciprocal miscibility of the selected oxides permit. The weight concentration of the "electronic dope additive" will possibly be lower, for example, 0.1 to 5% in the case of CeO 2 or the oxides of transition metals.
A preferred base oxide is formed by zirconium dioxide, the obtained solid solutions having ionic conductivities which are already appreciable at temperatures of the order of 600°C.
Typical solid solutions of the invention, which to a great extent possess the properties of ionic and electrical conductivity respectively, are formed of ZrO 2 , Y 2 O 3 and CeO 2 obtained in percentages by weight of, respectively, 86%, 10% and 4%, or even 90%, 9% and 1%. These solid solutions can be represented by the following respective formula:
ZrO.sub.2 (0.86) Y.sub.2 O.sub.3 (0.10) CeO.sub.2 (0.04)
zrO.sub.2 (0.90) Y.sub.2 O.sub.3 (0.09) CeO.sub.2 (0.01)
the solid solutions according to the invention are capable of conducting an electric current when introduced into an electric circuit, this conduction being accompanied by the conversion of this solid solution into its "reduced form", with oxygen in its gaseous form being eliminated. In the case of the typical compounds indicated above, this conversion can be observed for potential differences ranging from several volts to several dozen volts. The solid solutions in their reduced form have considerable affinity for oxygen as soon as the flow of electric current is interrupted. A hundred grams of such a solid solution can "trap" approximately 1 liter of oxygen. This affinity imparts to these solid solutions in the reduced form a capacity for eliminating oxygen which permits rates of purification giving rise to partial oxygen pressures of less than 10.sup. -20 and even 10.sup. -30 atmospheres. The affinity of these solid solutions proves to be almost the same as that of titanium, that is to say, much higher than that of the copper-based alloys. It is such that even the traces of water vapour and carbon monoxide are reduced to the state of hydrogen and carbon.
A particularly interesting additional property of the solid solutions based on zirconium dioxide resides in the fact that the reduced form of the solid solution is black, the solid electrolyte not returning to its white form until it is completely oxidized again. This change in colour consequently permits easy checking and control of the adsorption properties of the material in relation to the oxygen.
Another particularly interesting property which can be used to determine the saturation point of the trap concerns the electrical conductivity of the utilizable materials. The conductivities of the reduced forms are always much higher than those of corresponding oxidized forms. The conductivities undergo a sudden variation at saturation point. As an example for the solid solution comprising (ZrO 2 ) 0.87, (Y 2 O 3 ) 0.12, (CeO 2 ) 0.01, the ratio between the conductivities of the reduced and oxidized forms is always greater than 10 within the temperature range 600°-900°C.
In accordance with another advantageous feature of the invention, the said block is porous. It is simple to produce such a porous block by calcinating or roasting a powder of the selected preformed solid solution. The porosity considerably promotes exchanges between the gaseous phases containing traces of oxygen and the solid solution.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features of the invention will become apparent in the course of the following description of preferred embodiments of traps according to the invention, in connection with the drawings in which:
FIG. 1 is a diagrammatic view showing an oxygen trap capable of discontinuous or intermittent operation, and
FIG. 2 is a diagrammatic view showing the essential components of an oxygen trap capable of continuous operation.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows an experimental type of oxygen trap comprising an enclave 2, means of admitting gas to be purified comprising a connection 4 controlled by a shutter or valve 6, and means of evacuating this gas from the enclave, comprising a connection 8 controlled by a valve 10, and, inside the enclave 2, a porous block 12 formed of a solid solution such as that defined above, the gas admitted through the connection 4 being unable to be evacuated by the connection 8 until it passes through the porous block 12.
In the illustrated embodiment the enclave 2 and the block 12 are both generally cylindrical in shape, the block being maintained in position in this enclave, for example, by means of constricted zones 14 formed therein.
The block 12 is inserted in an electric circuit comprising a direct or rectified current generator 15 whose terminals are electrically connected to opposite ends of the block, for example, by means of metal conductors 16a, 16b which are simply brought into contact with the solid electrolyte. In the experimental enclave shown in FIG. 1 they are embedded in the ends of the block 12, having been secured particularly by being sintered together with this block during the formation of the latter.
A furnace 16 encloses the enclave 2, at least that part in which the block 12 is located, this furnace being suitable for bringing the solid solution to the temperature at which it exhibits appreciable degrees of ionic and electrical conductivities, for example from 600° to 800°C, when the block is formed of the solid solution containing the oxides of, respectively, zirconium, yttrium and cerium, particularly in the proportions indicated above.
The apparatus shown in FIG. 1 also comprises means, particularly a connection 20 and a valve 22 for admitting an inert gas into the enclave, as well as means of evacuating this gas, comprising particularly a connection 24 and a valve 26, these latter admitting and evacuating means being preferably arranged in such a manner that the introduced gas is caused to circulate in the opposite direction to that normally followed by the gas to be purified at an earlier stage.
The apparatus so arranged operates therefore in the following manner. During the first stage the solid solution of the block 12 is converted into its reduced form, particularly by passing an electric current through the block, the direction of the current resulting from the indication of positive and negative polarities respectively associated with the conductors 16a, 16b. During this operation the valves 6 and 10 are closed while the valves 22 and 26 are open and permit the passage through the porous block of an inert gas, such as nitrogen or a neutral gas, which draws off the oxygen liberated by the process of electrochemical reduction. When the solid solution is that indicated above by way of example, this reduction process is accompanied by a blackening of the porous mass. At the end of this process the current to the electric circuit is interrupted. The oxygen trap is therefore ready for operation, particularly in the following conditions.
The valves 22 and 26 are closed, and the valves 6 and 10 are open, the latter therefore allowing the gas for purification to be admitted into the enclave via the connection 4, brought into contact with the porous block 12 and evacuated by way of the connection 10. The traces of oxygen contained in the gas to be purified are therefore drastically reduced by the solid solution of the block 12. Observation of the colouring of the latter makes it possible to determine the precise moment when its capacity for adsorption is exhausted since it will not return to its white colour until it is completely oxidized again.
The variation in the conduction or electrical resistance of the trap can be used to be same end, as indicated above.
It will also be observed that adsorption of the oxygen is rapid irrespective of the degree of oxidation of the solid solution, and in particular that the rate of adsorption of the oxygen is not appreciably affected by this degree of oxidation as long as the latter is lower than the value which it exhibits in natural solid solutions.
When this degree of maximum oxidation is reached, the solid solution is regenerated by being converted into its reduced state, in the conditions which have been indicated above.
The trap just described is therefore suitable for discontinuous operation. A variation of this oxygen trap is shown in FIG. 2, this modification being capable of continuous operation. The different elements of te apparatus shown in FIG. 2 are designated by the same reference numerals, with the addition of a distinguishing letter, as the corresponding elements of the apparatus in FIG. 1. Only the distinct parts are designated by new reference numerals.
The apparatus shown in FIG. 2 differs essentially from that in FIG. 1 in that the enclave 2a is divided into two separate compartments 28 and 30, in that the block 12a comprises two parts 31a, 31b arranged in the compartments 28, 30 respectively, and in that a seal is effected between the two compartments and between the said parts 31a, 31b, without the gases which are in contact with one of the latter being able to diffuse in a gaseous state into the other part through the block 12a.
The parts 31a, 31b of the block 12a are advantageously porous and separated by a compact or solid central part 31c, the two compartments 28, 30 being separated by a partition 32 in which is provided a central opening permitting passage to the block 12a, in the central part thereof, a joint made of enamel, for example, producing the seal between the central part 31c and the edges of the opening in the partition 32.
The block 12a is inserted in an electric circuit comprising a current generator 15a whose positive terminal is connected to the end 36 and negative terminal to the end 38 of the block 12a, in the compartments 28 and 30 respectively.
The gas to be purified is admitted into the compartment 30 via the connection 4a, the purified gas being evacuated through the connection 8a, while an inert gas is introduced into the compartment 28 via a connection 20a and evacuated out of the compartment 28 by way of the connection 22a.
The traces of oxygen contained in the gas introduced into the compartment 30 are therefore retained in the corresponding part of the block 12a, in the form of O 2 - ions which migrate into the mass of the porous block, particularly in the general direction indicated by the arrow 40, when the generator is energized, these oxygen ions being converted into atoms of gaseous oxygen in the vicinity of the end 36 of the block 12a which is in contact with the conductor 16a to which it surrenders its electrons. A neutral gas introduced for scavenging purposes into the compartment 28 via the connection 20a sweeps the oxygen in gaseous form towards the evacuating pipe 22a.
An oxygen trap which can operate continuously is obtained as a result.
By way of another example, it is pointed out that it is possible to purify a gas (delivery rate, 8 liters/hour) up to partial oxygen pressures of the order of 10.sup. -20 atmospheres
in approximately 20 minutes if this oxygen-containing gas has an initial content of the order of 1000 ppm,
in 70 hours for an initial content of 15 ppm,
in 600 hours for an initial content of 2 ppm,
with an apparatus such as that shown in FIG. 1 in which the block 12 comprises a 10 gram cylinder having a porosity of 30% and formed of a solid solution (ZrO 2 ) 0.87, (Y 2 O 3 ) 0.12, (CeO 2 ) 0.01, which is previously reduced at a temperature of 900°C by applying to its opposite ends a potential difference of between 70 and 10 Volts (constant intensity equal to 200 mA) for 30 minutes under a current of argon in order that the liberated oxygen may be removed by electrochemical reduction.
It is interesting to note that, after 4 months of continuous operation during which more than 50 oxidation-reduction cycles took place, the trap in this embodiment showed no sign of wear, its properties having remained fully reproducible since the beginning of its use.
Irrespective of the embodiment adopted, one therefore obtains an oxygen trap which has a considerable degree of effectiveness in the absence of any undesirable secondary reaction capable of causing the deterioration of either the adsorption material of the oxygen or the finally obtained purified gases.
The invention lends itself particularly to the purification of inert gasses such as nitrogen, or neutral gases such as argon, helium, etc., by the removal of traces of oxygen which they may contain, and consequently finds particularly advantageous application in the laboratory and electronics industry (manufacture of electronic components or lamps or valves in a strictly controlled atmosphere), etc.
It will also be appreciated that the activity of the materials used in the oxygen traps according to the invention is very rapid. It is moreover also possible to determine and measure the quantity of oxygen contained in a medium, if only by the quantity of oxygen absorbed in the material.
When hafnium dioxide is used instead of zirconium dioxide in the traps under consideration, traps are obtained whose operating characteristics are substantially similar to those which were indicated in the examples above.
The replacement of zirconium dioxide with thorium dioxide in the materials in question permits even purification of gas containing traces of oxygen which is even further developed than with the two aforementioned dioxides.
It is obvious as a result of the preceding description that the invention is by no means limited to those of its embodiments which have been considered in more detail; indeed it covers all modifications. | 4y
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This application claims the benefit under 35 U.S.C. 119(e) of U.S. Provisional Application Ser. No. 61/039,864, filed Mar. 27, 2008, the disclosure of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to cylinder locks and particularly to pin tumbler cylinder locks with axial sliding detainers that provide a secondary locking mechanism in the cylinders.
2. Discussion of the Background
An ongoing problem for people using locks is other people trying to pick these locks. Pin tumbler locks, a traditional type of lock, are so common that one can buy tools specifically designed to pick a pin tumbler lock. At the same time, pin tumbler technology is well known, and consumers are comfortable with pin tumbler keys. As described below, many have looked to develop an improved lock that is less susceptible to lock picking.
A. Sohm in U.S. Pat. No. 1,141,215 discloses a cylinder where the plug contains moveable wards, or sliders, that are pushed axially by the insertion of the key. The sliders have a key contact surface and a projecting blade that extends into the shell. The shell contains annular grooves that will accept the projecting blade when the sliders are correctly positioned by the key. When the blades are positioned within the annular grooves, the plug is free to turn.
The moveable wards or sliders of this invention are primary locking elements in the cylinder. They also directly block the rotation of the plug within the shell.
B. Perkut in German Pat. No. DE 2 828 343 teaches two locking concepts. The first one (see FIG. 5 ) is of a moveable ward or slider that is very similar to the Sohm patent, but is used as a secondary locking mechanism in a pin tumbler cylinder. The slider 12 ′ has a blade 34 that extends into the shell and must be pushed by the key to an unlocked position, whereupon the blade is located in an annular ring 38 in the shell. This slider directly blocks the rotation of the plug within the shell.
The second locking concept (see FIGS. 1-4 ) also uses the slider as an auxiliary locking mechanism. The slider 12 , interfaces with a ball 20 that extends from the plug into the shell and blocks the rotation of the plug. The slider has a cavity 18 that will accept the ball when the slider is pushed to a correct axial position. When both the primary tumbler pins 106 a and 106 b and the slider are correctly aligned, the rotation of the plug forces the ball out of the shell into the plug and into the cavity 18 in the slider. Thus the plug can rotate freely. This slider provides an intermediary member, the ball, to block the rotation of the plug within the shell. However the curved shape of a ball will allow the plug to turn even if the slider is not precisely positioned.
G. Brandt in U.S. Pat. No. 5,615,566 also discloses a cylinder where the plug contains an auxiliary locking element, or slider, in addition to the regular pin tumblers. The Brandt slider 16 has a projecting blade 54 that extends out the back side of the plug and fits into a notch 24 in the shell. When the slider is pushed to the rear-most position by the insertion of the key, the slider is pushed out of the notch in the shell, and if the tumbler pins are also correctly aligned, the plug is free to rotate. The slider directly blocks the plug from rotating within the shell.
P. Field et al. in U.S. Pat. No. 6,477,875 discloses a cylinder where the plug contains sliders 24 or 24 ′ that move axially and provide tertiary locking mechanisms in the cylinder. The rotating pins must be correctly elevated for the shear line and also be rotationally aligned for the sidebar mechanism 16 or 16 ′ before the cylinder will unlock. Additionally, the sliders in the Field invention have projecting blades 32 or 32 ′ that are used to block the sidebar mechanism. The slider must be positioned at the correct axial location before the sidebar can contact the rotating pins. This slider blocks the motion of the sidebar in the plug.
Additional detailed specifications of a sidebar cylinder with a P. Field et al. slider and the key interface is provided in U.S. Pat. No. 6,945,082.
B. Field et al. in U.S. Pat. Application Publication 2007/0137272 teaches a cylinder that contains a sidebar 18 that is axially positioned by the side of a key. When moved to the correct position, the ends of the sidebar are at a location to allow the sidebar to cam into the plug and contact the side of the keyblade. If the key blade is configured with a shape corresponding to the edge of the sidebar 36 , the sidebar can move and allow the plug to rotate. The sliding sidebar directly blocks rotation of the plug in the shell.
The inventor has found that these lock designs have room for improvement. In particular, these additional mechanisms require valuable space within a traditional pin and tumbler design, and thus require that locks incorporating these features must be large or, alternatively, if a large lock is not possible, these features must be foregone.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a secondary locking mechanism within a cylinder whereby the primary tumbler pins are left unchanged and the secondary mechanism will provide for additional master keying levels without changing the key hole in the cylinder.
It is desirable to reduce the size and configuration of the components in a cylinder with an auxiliary slider mechanism, so that the mechanism can be used to key together, in the same key system, cylinders of various sizes and shapes.
It is desirable to provide a new smaller secondary locking mechanism in a cylinder, so that the key that will operate a slider and sidebar cylinder will also operate in a cylinder without space to accommodate a sidebar mechanism, thus providing expanded keying systems.
Aspects of the invention are embodied in a lock comprising a cylindrical plug having an axially-extending keyway adapted to receive a conforming key, a plurality of tumbler pins, an auxiliary locking pin, and a slider. The tumbler pins are disposed within radially-oriented tumbler pin holes formed in the cylindrical plug and adapted to control rotation of the cylindrical plug and are constructed and arranged to be engaged by a properly configured key inserted into the keyway and to be positioned by the key within their respective tumbler pin holes so as to permit the cylindrical plug to rotate. The auxiliary locking pin is disposed within the cylindrical plug and is moveable between a first position in which a portion of the auxiliary locking pin extends out of a hole formed in an outer wall of the cylindrical plug and a second position in which the auxiliary locking pin is retracted into the hole. The slider is disposed within the cylindrical plug and is moveable in an axial direction between a first position and a second position. The slider is constructed and arranged to be engaged by a cooperating key inserted into the keyway to move the slider from the first position to the second position, and the slider is operatively inter-engaged with the auxiliary locking pin such that the auxiliary locking pin is in its first position when the slider is in its first position and the auxiliary locking pin moves from its first position to its second position when the slider is moved from its first position to its second position.
Further aspects of the invention are embodied in a lock comprising a cylindrical plug having an axially-extending keyway adapted to receive a conforming key, a plurality of tumbler pins, and an auxiliary locking pin. The tumbler pins are disposed within radially-oriented tumbler pin holes formed in the cylindrical plug and adapted to control rotation of the cylindrical plug and are constructed and arranged to be engaged by a properly configured key inserted into the keyway and to be positioned by the key within their respective tumbler pin holes so as to permit the cylindrical plug to rotate. The auxiliary locking pin is disposed within the cylindrical plug and is moveable between a first position in which a portion of the auxiliary locking pin extends out of a hole formed in an outer wall of the cylindrical plug and a second position in which the auxiliary locking pin is retracted into the hole. The auxiliary locking pin includes a key contact projection extending into the keyway and constructed and arranged to be engaged by a conforming key to move the auxiliary locking pin from its first position to its second position as the conforming key is inserted into the keyway.
These and other features, aspects, and advantages of the present invention will become apparent to those skilled in the art after considering the following detailed description, appended claims and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a cylinder lock with an auxiliary locking mechanism according to one embodiment.
FIG. 2 is a cross-sectional perspective view of the cylinder lock without a key inserted and with a slider and an auxiliary locking pin both in respective first positions.
FIG. 3 is an end view of the cylinder lock without a key inserted.
FIG. 4 is a side cross-sectional view of the cylinder lock along the line 4 - 4 in FIG. 3 with the slider and the auxiliary locking pin both in respective first positions.
FIG. 5 is a side view of the cylinder lock without a key inserted.
FIG. 6 is an end cross-sectional view of the cylinder lock along the line 6 - 6 in FIG. 5 with the slider and the auxiliary locking pin both in respective first positions.
FIG. 7 is a cross-sectional perspective view of the cylinder lock with a key inserted into the lock and with the slider and the auxiliary locking pin both in respective second positions.
FIG. 8 is an end view of the cylinder lock with a key inserted into the lock with the slider and the auxiliary locking pin both in respective second positions.
FIG. 9 is a side cross-sectional view of the cylinder lock along the line 9 - 9 in FIG. 8 with the slider and the auxiliary locking pin both in respective second positions.
FIG. 10 is a side view of the cylinder lock with a key inserted.
FIG. 11 is an end cross-sectional view of the cylinder lock along the line 11 - 11 in FIG. 10 with the slider and the auxiliary locking pin both in respective second positions.
FIG. 12 is a perspective view of a key for use in the cylinder lock of the present invention.
FIG. 13 is a rear perspective view of a slider for use in an auxiliary locking mechanism according to the present invention.
FIG. 14 is a front perspective view of the slider.
FIG. 15 is a bottom rear perspective view of the slider.
FIG. 16 is a top plan view of a cylinder plug of an alternative embodiment cylinder lock.
FIG. 17 is a bottom plan view of the cylinder plug shown in FIG. 16 .
FIG. 18 is a side view of a cylinder lock.
FIG. 19 is an end cross-sectional view of the cylinder lock along the line 19 - 19 in FIG. 18 showing an alternative embodiment without a key inserted and with an auxiliary locking pin in a first position.
FIG. 20 is a side view of a cylinder lock with a key inserted
FIG. 21 is an end cross-sectional view of the cylinder lock along the line 21 - 21 in FIG. 20 showing the alternative embodiment with the auxiliary locking pin in a second position.
FIG. 22 is an end cross-sectional view of the cylinder lock along the line 19 - 19 in FIG. 18 showing the alternative embodiment with the auxiliary locking pin in a third position.
FIG. 23 is a side view of a key for use in the alternative embodiment.
DETAILED DESCRIPTION
FIG. 1 illustrates an exploded view of a cylinder lock 10 according to one embodiment of the invention. Cylinder lock 10 includes a cylindrical plug 70 , a control sleeve 20 , a shell 40 , a faceplate 100 , and an auxiliary locking mechanism 120 The cylinder lock 10 shown in FIG. 1 is of the type known as a small format interchangeable core cylinder. This is for the sole purpose of illustrating an embodiment of the inventive lock incorporating an auxiliary locking mechanism and is not intended to be limiting, as the auxiliary locking mechanism could be incorporated into other locks as well.
The shell 40 includes an upper section 42 and a lower section 52 . Lower section 52 has a hollow, generally cylindrical configuration. The upper section 42 has a solid, generally cylindrical configuration and includes tumbler pin holes 44 which receive conventional tumbler pins 90 (i.e., pin stacks). Upper section 42 includes a recess 46 extending along the axial length of the shell 40 along the bottom of the upper section 42 . The shell 40 further includes a flanged protrusion 50 , configured to interlock with recessed portion 104 (e.g., a dovetail slot) formed in the faceplate 100 . The lower section 52 of the shell 40 is hollow to receive the control sleeve 20 and the plug 70 . Service holes 54 formed in the bottom of the lower section 52 of the shell 40 allow a locksmith to remove tumblers from the tumbler holes 44 to re-key the lock 10 . A cutaway section 56 is formed in the rear of the lower section 52 of the shell 40 .
The control sleeve 20 is housed inside the shell 40 . Control sleeve 20 has a hollow, cylindrical configuration with a raised portion 22 . Tumbler holes 24 formed in the raised portion 22 of the control sleeve 20 align with tumbler holes 44 formed in the shell 40 when the control sleeve 20 is inserted into the shell 40 , such that tumblers 90 inside may move up and down to control rotation of the plug 70 in a conventional manner. Service holes 30 formed in the bottom of the control sleeve 20 align with service holes 54 formed in the shell 40 . The control sleeve 20 includes a control lug 26 along part of one side of the raised portion 22 . Raised portion 22 of the control sleeve 20 is received within the recess 46 formed in the upper section 42 of the shell 40 , and control lug 26 interlocks with the bottom of the upper section 42 of the shell 40 to lock the control sleeve 20 within the shell 40 . The control sleeve 20 further includes an auxiliary locking pin hole 32 .
The faceplate 100 includes a guard 102 with a recess 104 (e.g., a dovetail slot) which mates with the flanged protrusion 50 of the shell 40 and a ring 106 which rests against the opening of the lower section 52 of the shell 40 .
The plug 70 is mounted for axial rotation within the control sleeve 20 , which is disposed within the lower section 52 of the shell 40 . Tumbler holes 72 are formed in the plug 70 and communicate with a keyway 80 formed axially into the plug 70 . Plug 70 further includes an auxiliary locking pin hole 78 . Tumblers 90 disposed within the tumbler holes 72 operate along with a key in a conventional manner to control rotation of the plug 70 . This rotating action is generally used to release a latching mechanism (not shown). A retainer groove 74 formed in the rear end of the plug 70 receives a retainer clip 76 for securing the plug 70 within the sleeve 20 and shell 40 .
Pin stacks 90 of various bottom pins 92 , master wafers, top pins 96 , and springs 94 are positioned in the tumbler holes 72 , 24 , and 44 . Arrangements of spring loaded pins provide master keying capability and are well known in the lock art.
The head 86 of the plug 70 has a stepped perimeter which mates with the ring 106 on the faceplate 100 . The head 86 of the plug 70 provides the entry to a keyway 80 . The entry has formed keyway guides 82 which extend across the face of the entry. These guides, formed by the depressions, may be useful in guiding a key (shown later) into the keyway 80 by redirecting the force of the oncoming key along the face of the depression such that the key is aligned with the keyway 80 .
The cylinder plug 70 of the small format interchangeable core cylinder shown includes two longitudinally extending blind bores 88 (see FIGS. 2 , 4 and 9 ) bored parallel to the keyway 80 from the rear portion of the barrel of the cylinder plug 70 . One bore 88 is formed on each side of the keyway 80 , and the two bores 88 engage with corresponding prongs of a tailpiece (not shown), all of which are rotatably disposed in the cylinder shell 40 , to operate the lock mechanism as the key turns.
The auxiliary locking mechanism 120 includes an auxiliary locking pin 122 , a pin spring 134 , a pin-actuating slider 136 , and a slider spring 152 . Further details of the auxiliary locking mechanism 120 are shown in FIGS. 2 , 4 , 6 , 7 , 9 and 11 .
The auxiliary locking mechanism 120 is housed inside the plug 70 . More specifically, the slider 136 and slider spring 152 are disposed within an axially arranged slider cavity 160 , and the locking pin 122 and the pin spring 134 are disposed with a pin cavity 170 formed generally a right angle to the slider cavity 160 (See FIGS. 4 and 9 ). The slider 136 is biased by spring 152 disposed between a back end of the slider 136 and a back end of the cavity 160 opposite the forward end of the slider cavity 160 (i.e., toward the head 86 of the plug 70 ).
The auxiliary locking pin 122 includes an upper shaft 124 , which is surrounded by the pin spring 134 , and a lower point, or tip, 128 that is in contact with the slider 136 . The auxiliary locking mechanism 120 effects auxiliary locking by the top 126 of the upper shaft 124 extending through auxiliary locking hole 78 and 32 (formed in the plug 70 and the control sleeve 20 , respectively) into gap 48 defined within recess 46 adjacent the raised portion 22 (see FIGS. 4 and 6 ). The locking pin 122 then resists rotation of the plug 70 by contacting the sides of hole 32 . The auxiliary locking pin 122 must provide enough strength to resist a rotational force upon the plug 70 . In particular, if a lock 10 were compromised by aligning the tumblers with the shear line (e.g., by bumping the lock), the auxiliary locking pin 122 ought to be able to resist rotation of the plug 70 . A preferred material for the auxiliary locking pin 122 is stainless steel.
The top 126 of the auxiliary locking pin 122 is sloped to conform with the peripheral curvature of cylindrical plug 70 .
The auxiliary locking pin 122 includes a radial shoulder 130 to provide a stop for the pin spring 134 . A shoulder projection 132 protrudes from the shoulder 130 toward the face of the locking cylinder 10 . The auxiliary locking pin spring 134 is disposed around the upper shaft 124 and extends from the shoulder 130 into a counterbore formed coaxially with pin hole 78 to provide a downward biasing force upon the auxiliary locking pin 122 . The shoulder projection 132 is rectangular in cross-section and is sized to conform to the sides of the auxiliary pin cavity 170 , as shown in FIGS. 6 and 11 , to ensure that the auxiliary locking pin 122 does not rotate around its longitudinal axis. Because the tip 126 of the locking pin 122 is sloped to conform to the plug 70 , it is important that the pin 122 maintain a consistent orientation and not rotate about its longitudinal axis. If the auxiliary locking pin 122 were to rotate about its longitudinal axis, the top 126 of the auxiliary locking pin 122 would slope in a direction not conforming with the curvature of the plug 70 .
The bottom tip 128 of the auxiliary locking pin 122 sits atop the slider 136 .
As shown in FIGS. 13-15 , slider 136 includes an angled notch 142 which defines angled side walls 144 , a rear body portion 138 , a spring hole 140 formed in the rear body portion 138 in an axial orientation with respect to the plug 70 , and a curved bottom portion 146 having a curvature generally conforming to the peripheral curvature of the plug 70 . Slider 136 further includes a side projection 148 defining a contact surface 150 . When the slider 136 is installed in the slider cavity 160 , the side projection 148 and the contact surface 150 extend into the keyway 80 , and the bottom portion 146 conforms to the curvature of the plug 70 , so the slider 136 is retained within the slider cavity 160 by the control sleeve 120 .
As shown in FIGS. 2 and 4 , the slider spring 152 , having one end inserted into spring hole 140 , urges the slider 136 toward a first position at the forward end of the slider cavity 160 . As shown in FIGS. 2 , 4 , and 6 , with the slider 136 in this forward position, the pin 122 contacts the top of the rear main body 138 of the slider, thereby holding the pin in a first position with the upper shaft 124 extending through the auxiliary pin locking hole 122 into the gap 48 to prevent rotation of the plug 70 and preventing the pin 122 , which is biased downwardly by the pin spring 134 , from moving from this first position. When engaged by a key (as described in more detail below), the slider 136 is moved, against the bias of the slider spring 152 , to a second position toward the back of the slider cavity 160 . Meanwhile, the tip 128 of the auxiliary locking pin 122 slides along the top of the slider and into the notch 142 , sliding along the angled wall 144 to the bottom of the notch 142 , as shown in FIGS. 7 , 9 , and 11 . With the pin 122 moved into this second position, the upper shaft 124 withdraws from the gap 48 , through the auxiliary pin hole 32 formed in the control sleeve 20 , so that the plug 70 may rotate within the control sleeve 20 .
When a key is removed, the slider 136 is allowed to move under the force of spring 152 from the second position to the first position toward the front of the slider cavity 160 . The tip 128 of the auxiliary locking pin 122 slides up along the angled wall 144 to the top of the rear main body 138 of the slider 136 . The upper shaft 124 again protrudes through auxiliary locking pin hole 32 into gap 48 , and the plug 70 is again locked against rotation.
Preferably, the angled side walls 144 of the notch 142 form an angle of about 90°. If the angles of the side walls 144 are too steep, then it will be difficult for the tip 128 of the auxiliary locking pin 122 to slide up the side wall 144 and out of the angled groove 142 as the slider 136 moves from the back, second position to the forward, first position. On the other hand, if the angles of the side walls 144 are too shallow, the linear distance required for the angled notch 142 to reach the necessary depth to permit the upper shaft 124 of the locking pin 122 to fully withdraw from the gap 48 will be too great, which will require an unnecessarily long slider.
A key 200 configured for use in the cylinder lock 10 is shown in FIG. 12 . Key 200 includes a bow 202 , which may include a key ring hole 204 , a shoulder, or key stop, 206 , and a key blade 208 . Key blade 208 includes a biting edge 210 having teeth 212 . A slider catch 218 is formed in a lower, forward edge of the key blade 208 . The slider catch 218 comprises a slider cut 220 , which is intended to move past the slider (not shown), and a slider contact surface 222 , which is intended to engage the slider contact surface 150 . The distal end of the key blade has a tip stop 224 . Blade profile features, such as longitudinal shelf 214 , may be provided to control access to the keyway by forming a keyblade and keyway to have conforming profiles permit the only the correctly-profiled key to be inserted into a keyway.
When key 200 is inserted into the keyway 80 , the teeth 214 of the biting 210 engage pin stacks 90 to elevate the tumblers to correct positions to unlock the plug 70 . The depth to which the key 200 can be inserted into the keyway 80 will be determined by the shoulder 206 or the tip stop 224 . Also, the slider contact surface 222 will engage the contact surface 150 of the slider 136 to move the slider from the first, locking position shown in FIGS. 2 , 4 , and 6 to the second, unlocked position shown in FIGS. 7 , 9 and 11 .
FIGS. 16-23 illustrate components of a cylinder lock according to an alternative embodiment of the invention. The cylinder lock according to this alternative embodiment, like cylinder lock 10 described above, includes an auxiliary locking mechanism which includes an auxiliary locking pin, but does not include a slider which actuates the pin. FIG. 18 shows a side view of a cylinder lock 310 , and FIG. 19 shows a cross-section of the cylinder lock 310 of FIG. 18 . Cylinder lock 310 includes a cylindrical plug 370 , a control sleeve 320 , a shell 40 , a faceplate 100 , and an auxiliary locking pin 422 As with cylinder lock 10 described above, cylinder lock 310 shown in FIGS. 18-22 is of the type known as a small format interchangeable core cylinder. This is merely for the purpose of illustrating this alternative embodiment of the inventive lock incorporating an auxiliary locking mechanism and is not intended to be limiting, as the auxiliary locking mechanism could be incorporated into other locks as well.
The shell 40 of the alternative embodiment shown in the figures is identical to shell 40 described above, and thus the description will not be repeated.
The control sleeve 320 is housed inside the shell 40 . Control sleeve 320 has a hollow, cylindrical configuration with a raised portion 322 . Tumbler holes 324 formed in the raised portion 322 of the control sleeve 320 align with tumbler holes 44 formed in the shell 40 when the control sleeve 320 is inserted into the shell 40 , such that tumblers (described above) inside may move up and down to control rotation of the plug 370 in a conventional manner. Service holes 330 formed in the bottom of the control sleeve 320 align with service holes 54 formed in the shell 40 . The control sleeve 320 includes a control lug 326 along part of one side of the raised portion 322 . Raised portion 322 of the control sleeve 320 is received within the recess 46 formed in the upper section 42 of the shell 40 , and control lug 326 interlocks with the bottom of the upper section 42 of the shell 40 to lock the control sleeve 320 within the shell 40 . The control sleeve 320 further includes an upper auxiliary locking pin hole 332 and a lower auxiliary locking pin hole 334 .
The faceplate 100 of the alternative embodiment and its engagement with shell 40 is identical to faceplate 100 described above, and thus the description will not be repeated.
The plug 370 is mounted for axial rotation within the control sleeve 320 , which is disposed within the lower section 52 of the shell 40 . Tumbler holes 372 are formed in the plug 370 and communicate with a keyway 380 formed axially into the plug 370 . Tumblers (described above) disposed within the tumbler holes 372 operate along with a key in a conventional manner to control rotation of the plug 370 .
Plug 370 further includes an auxiliary locking pin hole 378 , which includes an upper pin cavity 472 and a lower pin cavity 470 having a smaller diameter than the upper spring cavity 472 . As shown in FIGS. 16 and 17 —which show top and bottom plan views, respectively, of the cylinder 370 —an area, designated by reference number 382 , between the hole 378 and keyway 380 and one of the tumbler holes 372 is broached. The purpose of this broached area will be described below.
The auxiliary locking pin 422 is disposed within auxiliary pin locking hole 378 . The auxiliary locking pin 422 includes a shaft 424 , an upper tip 426 , a spring shoulder 430 , a key contact projection 432 , and a lower point, or tip, 428 . A pin spring 434 surrounds the upper shaft 424 . The auxiliary locking pin 422 effects auxiliary locking by the upper tip 426 of the auxiliary locking pin 422 extending from the auxiliary locking pin hole 378 through auxiliary pin hole 332 formed in the control sleeve 320 and into gap 48 defined within recess 46 adjacent the raised portion 322 (see FIG. 19 ). The locking pin 422 resists rotation of the plug 370 by contacting the sides of hole 332 . A preferred material for the auxiliary locking pin 422 is stainless steel.
The tip 426 of the auxiliary locking pin 422 may be sloped to conform with the peripheral curvature of cylindrical plug 370 .
The spring shoulder 430 of the auxiliary locking pin 422 provides a stop for the pin spring 434 . More specifically, spring shoulder 430 has a transverse dimension (e.g., diameter) that is greater than that of the upper shaft 424 and the upper tip 426 . The bottom of the spring shoulder 430 forms a radial flange that is substantially perpendicular to the longitudinal axis of the auxiliary locking pin 422 . In the illustrated embodiment, the top 426 has a smaller transverse dimension (e.g., diameter) than the spring shoulder 430 so as to fit within the gap 48 . Also, as seen in FIGS. 19 , 21 , and 22 , the lower pin cavity 470 has a smaller transverse dimension (e.g., diameter) than the upper pin cavity 472 . The change in dimension between the lower pin cavity 470 and the upper pin cavity 472 defines a radial ledge.
Pin spring 434 surrounds a portion of the upper shaft 424 and resides within the upper pin cavity 472 where it is retained between the radial flange defined at the bottom of the spring shoulder 430 and the radial ledge defined at the transition of the lower pin cavity 470 and the upper pin cavity 472 .
Pin spring 434 biases the auxiliary locking pin 422 upwardly. Thus, when the locking pin 422 is unengaged by a key, as shown in FIG. 19 , it is in a first position, extending, under the bias force provided by the pin spring 434 , through the upper auxiliary locking pin hole 332 of the control sleeve 320 to prevent the cylindrical plug 370 from rotating.
The auxiliary locking pin 422 also includes a key contact extension 432 , which extends laterally through the broached area 382 adjacent the lower pin cavity 470 into the keyway 380 . FIG. 20 shows a side view of the cylinder lock 310 with a key 500 inserted into the keyhole thereof. FIG. 21 is a transverse cross section of the cylinder lock 310 and key 500 taken through the auxiliary locking pin 422 . As shown in FIGS. 20 and 21 , when a properly configured key 500 (described in more detail below) is inserted into the keyway 380 , it engages the extension 432 and pulls the auxiliary locking pin 422 down into a second position in which the upper tip 426 of the pin 422 is retracted into the plug 370 to thereby permit the plug 370 to rotate with respect to the control sleeve 320 .
As shown in FIG. 22 , if the auxiliary locking pin 422 is moved down too far within the auxiliary locking pin hole 378 into a third position (for example, if engaged by the wrong key or if the pin is moved down too far in an attempt to pick the lock), the lower tip 428 of the pin 422 will extend through the lower auxiliary locking pin hole 334 of the control sleeve 320 to again prevent rotation of the plug 370 .
When the key is removed, the auxiliary locking pin 422 is allowed to move under the force of pin spring 434 from the second position shown in FIG. 21 back to the first position shown in FIG. 19 so that the upper tip 426 again protrudes through upper auxiliary locking pin hole 332 into gap 48 , and the plug 370 is again locked against rotation.
A key 500 configured for use in the cylinder lock 310 is shown in FIG. 23 . Key 500 includes a bow 502 , which may include a key ring hole 504 , a shoulder 506 , and a key blade 508 . Key blade 508 includes a biting edge 510 having teeth 512 . The key 500 also includes a key stop 516 .
A pin groove 514 is formed along the key blade 508 . The pin groove 514 comprises a groove, or channel, having a first portion 518 which receives the key contact projection 432 when the key 500 is first inserted into the keyway 380 and the auxiliary locking pin 422 is in its first position. Progressing along the key blade 508 , the pin groove 514 includes a transition 520 , which, in the illustrated embodiment, moves closer to the bottom edge of the blade 508 , to a terminal portion 522 of the groove 514 . As the projection 432 moves along the groove 514 , while the key 500 is inserted into the keyway 480 , it moves from the initial portion 518 , through the transition 520 , and down to the terminal portion 522 . The pin 422 is thus pulled down into the second position, retracted into the plug 370 , thereby allowing the cylinder to rotate, assuming the tumblers are also properly aligned.
The auxiliary locking pin 422 is installed into the plug 370 by dropping it down into the auxiliary pin locking hole 378 . The broached area 382 allows the pin 422 , with the extending projection 432 , to be inserted into the hole 378 .
In a further embodiment, a cylinder lock may include an auxiliary locking mechanism comprising more than one auxiliary locking pin of the type shown in FIG. 19 . That is, multiple auxiliary locking pins 422 can be provided along the length of the keyway 380 , each locking pin having a key contact projection 432 at a different height, so that the pins are lowered by different amounts to permit rotation of the cylinder plug. The pin groove provided in a proper key would be shaped to accurately position each locking pin 422 into its respective second position. If the wrong key is used, and one or more pins is(are) moved too little or too much, the upper tip 426 or the lower tip 428 of the locking pin 422 will be engaged in the upper pin hole 332 or the lower pin hole 334 of the control sleeve 320 to prevent the cylinder plug from rotating. Such an arrangement may not, however, be possible if the cylinder includes longitudinal bores (such as longitudinal bores 88 shown in FIGS. 2 and 4 ).
Thus, a preferred embodiment has been fully described above with reference to the drawing figures. Although the invention has been described based upon this preferred embodiment, it would be apparent to those of skill in the art that certain modifications, variations, and alternative constructions could be made to the described embodiments within the spirit and scope of the invention. | 4y
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RELATED APPLICATION
This application is a Continuation-In-Part of co-pending application Ser. No. 07/526,387, filed May 21, 1990, entitled METHOD OF PREFERENTIAL LABELLING OF A PHYCOBILIPROTEIN WITH A SECOND DYE FOR USE IN A MULTIPLE COLOR ASSAY AND PRODUCT FOR SUCH USE, now U.S. Pat. No. 5,171,846, issued Dec. 15, 1992. This application and U.S. Pat. No. 5,171,846 are solely owned by a common assignee. Coulter Corporation, Hialeah, Fla.
FIELD OF THE INVENTION
This invention relates generally to electron donor-acceptor conjugates suitable for use in multiple color assay methods, particularly to a method of producing phycobili-protein-dye conjugates suitable for such use.
BACKGROUND OF THE INVENTION
The technique of fluorescence was first introduced by Coons in 1941. He used a blue fluorescing anthracene compound coupled to pneumococcus antiserum to detect bacterial antigens in tissue section. Subsequent to this initial discovery, many fluorescing materials have been investigated, but only two, the fluorochromes fluorescein and rhodamine, are widely used, particularly in the form of fluorescein isothiocyanate (FITC) and tetramethylrhodamine isothiocyanate (TRITC) respectively. FITC covalently binds to proteins at alkaline pH through the epsilon (ε) amino residues of lysine and through terminal amino groups. FITC's adsorption maximum is at 490-495 nm and it emits its characteristic green color at 517nm. TRITC likewise binds to proteins, has its absorption maximum at 541 nm and emits its characteristic red color at 572 nm.
Fluorescence is the emission of light of one wavelength (color) by a substance that is being irradiated by light of a different wavelength. The emitted light is always of lower energy, hence longer wavelength, then the incident light. In clinical use, the strength of the fluorescence is dependent on the efficiency with which the fluorochrome transforms incident light into emitted light, the amount of dye present in the specimen under observation and the intensity of the incident light. The dye known as Texas Red (sulforhodamine 101 sulfonyl chloride or sulforhodamine acid chloride) has previously been investigated for clinical use in conjugation with phycoerythrins, but major problems were encountered. These problems were low fluorescent efficiency, inadequate energy transfer from the phycoerythrin to Texas Red and the instability of the phycoerythrin-Texas Red conjugate. Phycoerythrin-Texas Red conjugates are desirable, however, because the overlap of their absorption and emission spectra have the potential to give a strong fluorescence signal.
Low fluorescent efficiency occurs whenever fluorescent chromophores are spatially adjacent to each other. It is usually called concentration quenching. See R. P. Hughland, "Excited States of Biopolymers", R. F. Steins, Ed., p 47 (Plenum Press, New York, 1983). However, high levels of labelling, resulting in chromophores being spatially adjacent to each other, are required in order to assure adequate energy (electron) transfer from the phycoerythrin to the acceptor dye chromophore. The net result is that the trade off required by the opposing effects results in less than optimal performance. Recently, A. N. Glazer et al. have covalently linked a phycoerythrin to an allophycocyanin to produce a highly fluorescent tandem conjugate with an energy transfer efficiency of 90%. See A. N. Glazer et al., T.I.B.S, 9:423 (1984); Biophysics J., 43,386-386 (1983); and U.S. Pat. No. 4,542,104 (See also U.S. Pat. No. 4,520,110 to L. Stryer et al. describing the use of phycobiliproteins as fluorescent probes for the analysis and separation of molecules and cells). However, forming a conjugate from two naturally occurring pigments derived from algae is much different from conjugating a synthetic dye such as Texas Red. In fact, the procedures usually followed for conjugating reactive dyes to proteins does not work with phycoerythrin-Texas Red. Using such procedures, one obtains a complex with a low energy transfer efficiency at low levels of labelling or fluorescence quenching at high levels of labelling. Texas Red forms a conjugate with a phycoerythrin by reaction of its sulfonyl or acid chloride moiety with an amine group of phycoerythrin or other phycobiliprotein
Phycobiliprotein/amine-reactive dye conjugates are known and some, for example, phycoerythrin-Texas Red conjugates, are commercially available. For example, the phycoerythrin-Texas Red conjugate known as DuoCHROME™ is available bound to streptavidin from Becton Dickinson Immunology Systems, Mountain View, Calif. (Catalog No. 9026). The available conjugates, however, suffer from the fact that they do not have a uniform phycoerythrin-Texas Red ratio throughout the individual conjugate members. There are present overlabelled and underlabelled species as well as species having the desired or optimum degree or range of labelling. Consequently, energy transfer/quenching problems can arise depending upon the distribution of labelled species within the entire sample.
This invention solves the energy transfer/quenching problem encountered in the preparation of phycobili-protein/amine-reactive conjugates in general by preferentially labelling sites close to the chromophore regions of a phycobiliprotein with an amine-reactive dye and separating overlabelled and underlabelled conjugates from conjugates having the desired degree of labelling by chromatographic methods; for example, by exploiting the differences in hydrophobic character of conjugates having different degrees of labelling.
SUMMARY OF THE INVENTION
A method is provided for preparing a phycobiliprotein/amine-reactive dye (PARD) conjugate which overcomes the problems relating to the energy transfer/fluorescent quenching phenomenon encountered in such conjugates. An amine-reactive dye, such as Texas Red or a carboxyfluoroscein succinimidyl ester, is reacted with a phycobiliprotein, such as a phycoerythrin or an allophycocyanin, in the presence of a salt especially selected to cause an intramolecular rearrangement of the phycobiliprotein structure whereby to expose a multiplicity of sites in its hydrophobic region with which said dye can bind to form the desired conjugate. The reaction is controlled as to the anion of the selected salt, permitted time of reaction and temperature. Conjugates having the preferred degree of phycobiliprotein/amine-reactive dye conjugation are separated from overlabelled and underlabelled conjugates by hydrophobic interaction chromatography. Alternatively, hydrophobic interaction chromatography may be used to separate conjugates having the desire degree of labelling from a reaction mixture which did not use the selective salts taught herein.
DETAILED DESCRIPTION OF THE INVENTION
The first feature of this invention, preferential site labelling, makes it possible to obtain a satisfactory level of energy transfer between a phycobiliprotein and an amine-reactive dye even at low levels of dye conjugation by bringing the dye and the chromophore of the phycobiliprotein into close proximity. This is accomplished by making use of the hydrophobic tetrapyrrole (bilin) chromophores that biliproteins are known to possess. See R. McColl and D. Guard-Frier, Phycobiliproteins, Chapter I, C.R.C. Press (1987). Specifically, when certain anions commonly used in some "salting-out" processes are added to a phycobiliprotein containing buffer solution, they cause the phycobiliprotein to undergo an intramolecular structural rearrangement which "open-up" or "exposes" hydrophobic sites on the protein by reducing steric hindrance about the site. As a result of this hydrophobic intramolecular rearrangement, the sites close to chromophores can more readily react with a reactive dye, such as Texas Red, to form a conjugate. The common ions used in this process may be any of the common ions used in "salting-out" processes, such as phosphate, acetate, citrate, sulfate, tartrate and the like. The preferred anions are sulfate, phosphate and acetate. The most preferred anion is sulfate because it has little or no effect on the pH of the solution. The exact amount of anion required in a given reaction is dependent on the particular phycobiliprotein undergoing reaction. For example, when using the sulfate in a phycoerythrin-Texas Red (PETR) conjugation reaction, it was found that an anion concentration in the range of about 1% to about 4% in the reaction solution resulted in a PETR conjugate having significantly improved energy transfer efficiency as compared to a PETR control conjugate prepared in the absence of a preferred anion. On the other hand, allophycocyanin requires the use of about 8% to 12% sodium sulfate. Using the principles taught herein, the optimal concentration of the selected salt can easily be determined. Overall, the optimal concentrations will range between 1% and about 20%.
The phycobiliprotein and the amine-reactive dye are reacted together at a pH greater than 7 for a time in the range of 10 minutes and at a temperature of about 4° C. to about 25° C. prior to sampling to determine if an overall adequate phycobiliprotein-dye conjugation ratio has been reached. The preferred pH is greater than 8 and less than 12. The determination is carried out by chromatographically removing excess dye from a sample of the reaction mixture and spectroscopically determining an absorbance ratio, A x /A y , defined as the ratio of the intensity of the maximum absorption of the phycobiliprotein divided by the intensity of the maximum absorption of the amine-reactive dye. For a PETR conjugate, A x /A y is A 565 /A 595 . If the value of A 565 /A 595 is in the range of 2.9 to 3.2, the reaction mixture is quenched and excess dye is removed. The A x /A y value will differ for different PARD conjugates. The removal of the excess dye simultaneously removes excess salts such as the sodium sulfate preferably used to expose a phycobiliprotein's hidden hydrophobic sites.
An excess of amine-reactive dye is used in the claimed method. The initial molar ratio of amine-reactive dye to phycobiliprotein in the reaction mixture is in the range of about 5:1 to about 30:1.
A phycobiliprotein/amine-reactive dye conjugate is formed by reaction of an amino group on the phycobiliprotein with a reactive group present on the amine-reactive dye. For example, a phycoerythrin-Texas Red conjugate is formed by reaction of an amino group on phycoerythrin with the sulfonyl or acid moiety of Texas Red. The reactivity of phycobiliprotein amino groups is well known. For example, small biomolecules such as biotin have been attached to phycobiliproteins by reaction with an appropriate activated ester or sulfonyl chloride derivative. The reaction between phycobiliproteins and amine-reactive dyes as taught herein, for example, the reaction between phycoerythrin and Texas Red, is analogous to the biotin reaction and to the reactions of fluorescein isothiocyanate with the ε-amino residues of lysine and terminal amino groups previously mentioned. While any moiety reactive with amines may be used according to the invention, the preferred reactive moieties present on the amine-reactive dye are selected from the group consisting of sulfonic and carboxylic acids and their acid chlorides and esters. Specific examples of such dyes include 5- or 6-carboxyl-x-rhodamaine succinimidyl esters, sulforhodamine 101 sulfonyl chloride, Lissemine rhodamine B sulfonyl chloride. Compounds such as fluorescein-5-isothiocyanate and fluorescein- 6-isothiocyanate, are further examples of amine-reactive dyes.
Phycobiliproteins is general may be used according to the invention. In addition to phycoerythrin and allophycocyanin used in the Examples herein, C-phycocyanin, R-phycocyanin and phycoerythrocyanin, among others, may be reacted as described herein.
The separation of over-labelled and under-labelled PARD conjugate species from those having the desired degree of labelling was accomplished using hydrophobic interaction chromatography with an appropriate column medium like butyl toyopearl. The PARD conjugate produced by this method can be used in conjunction with an antibody to stain different types of cell. The cells so stained will be dependent upon the choice of antibody. The importance of the invention lies in the fact that PARD conjugates provide for an additional color in fluorescence analysis with the use of only a single excitation wavelength, which wavelength is determined by the choice of the amine-reactive dye. For example, FITC, R-phycoerythrin, PETR and APC-FSE can be excited with a single excitation wavelength (laser) of 488nm to emit maximally at about 525, 575, 612 and 660nm respectively. As a result of this feature, the expense of multiple excitation source is eliminated.
PREFERRED EMBODIMENTS OF THE INVENTION
Example 1
Reaction of Phycoerythrin and Texas Red.
In a typical reaction, a purified R-phycoerythrin (PE) solution [3.0 g PE, 45.04 ml solution; PE concentration is 66.6 mg/ml in 2 mM EDTA-PBS (PBS =Phosphate Buffered Saline) ] was cooled in ice-bath and treated dropwise, with stirring, with an ice-cold solution of PBS containing 2 mM EDTA (29.25 ml), 20% Na 2 SO 4 (pH 7.0, 6.0 ml) and 1 M Potassium Borate (pH 9.80, 30 ml). To the resulting mixture was added with vigorous stirring and at 4° C. a 25-fold molar excess of Texas Red (20 mg/ml in anhydrous dimethylformamide). The reaction was monitored by drawing 10 μL samples periodically and removing excess dye on a 0.5-2 ml SEPHADEX ® G-50 column in PBS. The protein containing peak was collected and its A 565 /A 595 value determined spectrophotometrically. If the A 565 /A 595 values remain above 3.2, even after 30 minutes or more of reaction time a further aliquot of Texas Red solution of 1-5 times the initial PE concentration was added to the reaction mixture.
When A 565 /A 595 value fell below 3.2, preferably in the range of 2.9-3.2, reaction may be quenched by addition of an one-hundred fold molar excess of a quenching agent glycine to the reaction mixture. Typical quenching agents are glycine, hydroxylamine hydrochloride, ethanolamine, lysine among others. Excess reactive dye was next removed by passing the reaction mixture through a SEPHADEX® G-50 column in PBS, 2mM EDTA. The phycoerythrin-Texas Red conjugate, in the protein peak, was then chromatographically factionated on a butyl 650 M (available from Toyo Haas, Philadelphia, Pa.) chromatographic column by eluting with a reverse gradient (3% to 0%) of sodium sulfate in 100 mM potassium phosphate solution containing 2 mM EDTA at pH 7.0 ±0.1. Chromatographic fractions having the desired emission characteristics (high energy transfer and high quantum efficiency) were pooled, concentrated, dialiyzed against PBS, 2 mM EDTA and reconcentrated to give a purified phycoerythrin-Texas Red conjugate. The purified PETR conjugate was used as a marker in fluorescent immunoassays. The PETR marker can be conjugated to protein-like substances such as antibodies and streptavidin using methods known in the art.
Example 2
Reaction of Allophycocyanin (APC) with a Carboxyfluorescein Succinimidyl Ester (FSE)
6.25 ml (292.4 mg) APC solution (46.748 mg/ml in PBS, 2 mM EDTA) was treated by dropwise addition, with stirring, of a solution resulting from mixing PBS, 2 mM EDTA (6.17 ml), 1 M borate of pH 9.80 (7.3 ml) and 20 wt % sodium sulfate of pH 7.0 (8.76 ml). A 14-fold excess of FSE (25 mg/ml in anhydrous dimethylformamide) was added to the APC solution at room temperature (about 22° C.). After 30 minutes, a 50 μL sample of the reaction mixture was withdrawn, excess dye removed on a SEPHADEX® G-50 column in PBS which was 2 mM in EDTA, and the protein A 496 /A 652 value for the protein peak was checked.
If the A 496 /A 652 ratio is less than 0.5 after 60 minutes or more reaction time, an additional aliquot of FSE was added to the reaction mixture. When an A 496 /A 652 value in the range of 0.5-0.7 is achieved, the reaction is stopped by removing excess dye on a SEPHADEX® G-50 column in PBS, 2 mM EDTA. Alternatively, a quenching agent is added to the reaction mixture prior to passage through the SEPHADEX® column. The protein peak is collected and the APC-FSE conjugate mixture is further fractionated using hydrophobic interaction chromatography on a butyl 650 S column using a reverse gradient (4% to 0%) sodium sulfate in 100 mM potassium phosphate, 2 mM EDTA of pH 7.0±0.1, followed by steps of 50 mM potassium phosphate, 2 mM EDTA of pH 7.0±0.1, and lastly, PBS, 2 mM EDTA. Fractions showing high energy transfer efficiency and high fluorescence were found to have an A 496 /A 652 ratio of about 0.4-0.6. These were pooled, dialyzed against PBS, 2 mM EDTA and concentrated. The yield was 54%. The conjugate was used without further purification
Example 3
APC-FSE Conjugate Prepared Without Using Selected Salts
APC and FSE is reacted as in Example 2, but without the addition of the selected salt The reaction time is extended within the range of 0.5 to 5.0 hours after the addition of FSE to APC is completed. The reaction mixture is then passed through a SEPHADEX® G-50 column and is subsequently fractionated by hydrophobic interaction chromatography. Fractions having A 496 /A 652 in the range of 0.4-0.6 is collected, dialyzed and concentrated, and may be used without further purification. | 4y
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The present invention relates to a machine in the form of a powered truck-like vehicle at the rear of which is provided an apparatus capable of cutting through concrete curbstones or sidewalks.
The purpose of my invention is to produce, with the apparatus mentioned above, a step through a curbstone or a drive-in ramp through a sidewalk, suitable to allow vehicles, particularly automobiles, to have an easy and smooth access to a drive way leading to a house or other building, either existing or to be constructed. In the case of a curbstone, the step mentioned above is usually horizontal while the ramp through a sidewalk takes on a slight incline of which the angle is normally prescribed by city bylaws. The intent, in both cases, is to provide a drive-in passage leading to the existing or proposed driveway.
A search of the prior art relevant to this type of equipment has revealed the following U.S. patents: U.S. Pat. No. 2,216,971 of 1940 U.S. Pat. No. 2,312,287 of 1943 U.S. Pat. No. 2,441,431 of 1948 U.S. Pat. No. 2,783,789 of 1957 U.S. Pat. No. 3,785,705 of 1974
I have additionally found U.S. Pat. No. 3,649,071 of 1972.
All of the above patents, except U.S. Pat. No. 3,785,705 which relates to a vertically operable saw of no particular interest here, relate to saws that can operate horizontally but that I find ill-adapted and/or not suited for cutting elongated passages through curbstones or sidewalks. This is mostly because the equipment described in these patents does not provide for adequate guide means for the saw. The closest and most pertinent disclosure, in my opinion, is that of U.S. Pat. No. 3,649,071.
The latter however shows a cutting equipment which is located centrally of a wheel-mounted frame attachable to a tractor or a similar vehicle. Now, in use, the wheels of the frame on one side may rest on the street pavement but those on the other side of the frame have to be located on the side of the curbstone or sidewalk where the soil is still in a very uneven condition so that the frame has to be levelled off in order to place the saw in horizontal position. This requires that the four corners of the frame be jacked up, this being of course particularly so for the two corners that stand above the soil which has not been levelled off. Now, in certain cases where the soil is in particularly bad condition, it is not even possible to dispose the cutting saw horizontally.
It is therefore a main object of the invention to provide a machine wherein the cutting equipment is so disposed that all of the cutting work can be done without the machine itself having to straddle the curbstone as with the aforementioned frame.
Another inconvenience in the cutting equipment of U.S. Pat. No. 3,649,071 is that while the saw is mounted so as to be able to cut inclined terminal portions at the ends of the elongated central portion of the access passage, it is not provided to cut an access passage with a central elongated portion having an inclination across either the curbstone or, as the case may be, across the sidewalk. In other words, the sawing machine of the above patent has no provision for cutting an inclined ramp through and across a sidewalk and is in fact not intended for that purpose.
Therefore, a further and additional main object of my invention lies in the provision of a machine with a cutting apparatus of the above general type which is suitable to cut slots through curbstones or sidewalks to provide an access passage that is horizontal or inclined.
Another object of my invention is the provision of such an apparatus wherein the angular adjustment of the cutting saw is easily and positively obtained and held throughout the cutting operation, regardless of the condition of the soil located on the side of the curbstone or sidewall opposite the paved street or road.
A still further object of the invention resides in that the apparatus of my invention has a bridge structure, onto which the saw and its travelling and operating machanisms are mounted, is so constructed as to allow a cutting operation either along a horizontal plane or along an incline of which the angle corresponds to a value set by the local city bylaws. Additionally, however, the saw holding bridge can be made to oscillate about its longitudinal axis so as to vary this predetermined angle where a sidewalk is either narrower or wider than the usual standard width.
Therefore and in accordance with the broad concept of my invention, there is provided and claimed herein a machine which includes a powered truck-like vehicle having a support base at the rear end and an apparatus for cutting a drive-in passage across a concrete curbstone, a sidewalk or the like, the apparatus being mounted on the base and comprising:
two spaced parallel booms mounted at one end on the base and an elongated bridge structure extending between and perpendicularly to the booms, being connected to them and provided with a drive so that it can be displaced along the booms with respect to the support base of the vehicle;
means pivoting the booms and bridge structure from an inoperative position where the bridge structure is above the support base to an operative position where the booms and bridge structure are swung outwardly of the support base in a position for cutting a curbstone, sidewalk or the like;
a carrier having a concrete cutting saw capable of rotating about an axis normal to the carrier;
means mounting the carrier on the bridge structure and displacing it in a first direction along one face of the structure which is on the side looking toward the support base;
means mounting the saw on the above-mentioned carrier and for displacing the saw mounting means and the saw along a second direction which is perpendicular to the first mentioned direction. In this manner, with the apparatus in the operative position, the rotary saw is first advanced in the second direction through the curbstone, sidewalk or the like and then in the first direction to cut an elongated slot determining the longitudinal extent of the drive-in passage.
According to a preferred form of the machine, the bridge structure has a central section and, at either end, a terminal section, the terminal sections being each pivotally mounted at one end of the central section and may be driven upwardly so that it can be placed at an incline suitable to displace the carriage and saw along a slope corresponding to the incline for cutting the curbstone, sidewalk or the like to produce the terminal inclined extents of the drive-in passage which join the longitudinal central extent.
Advantageously, the bridge structure may have a second face on the side which looks away from the support base, this second face making a predetermined angle with the one face, turn-table means being provided at the outer ends of the bridge structure to allow the carrier to thus move from one face to the second face, the bridge structure carrier mounting means including, for that purpose, carrier holding means on both faces. Thus, when the carrier rides on the second face, the saw is able to cut through a sidewalk at the predetermined angle.
As aforesaid, and in a further embodiment, the bridge structure is mounted on the booms so that it an oscillate along its longitudinal axis whereby to incline the saw at an angle which is other then the aforesaid predetermined angle.
Other objects and further advantages of the invention will become apparent to those skilled in the art from the following description of a preferred embodiment of the invention having reference to the appended drawings wherein:
FIG. 1 is a perspective view of a machine made according to the invention, including the apparatus for cutting a drive-in passage across a concrete curbstone, sidewalk or the like;
FIG. 2 is a top plan view of the machine of FIG. 1;
FIG. 3 is a side elevation view of the machine with the saw in position for cutting a horizontal slot;
FIG. 4 is a view similar to that of FIG. 3 but showing the saw in position for cutting an inclined slope through a sidewalk.
FIG. 5 is a perspective view of one end section of the bridge structure;
FIG. 6 (third sheet of drawing) is a side elevation view of the terminal bridge structure portion of FIG. 5;
FIG. 7 (fourth sheet of drawing) is a top plan view particularly illustrating one terminal portion of the bridge structure with the turn-table means to allow the carrier to move from one face of the bridge structure to the other;
FIGS. 8 and 9 are, respectively, a top plan view and a side elevation view of the saw carrier structure shown mounted on the partially illustrated bridge structure.
FIG. 10 is a perspective view of the carrier and turn-table.
GENERAL DESCRIPTION
A general description of the machine in accordance with this embodiment will first be given to facilitate a better understanding of the various features of the invention.
As shown in FIG. 1, the machine is a motor truck having the usual cab A and what is generally to be termed a support base B at the rear which may include a box intended to hold sundry implements useful in the operation of the machine and a fluid pressure reservoir C, being provided along one side of the box B. The pressure fluid may either be air or oil depending on whether pneumatic or hydraulic power jacks are being used to operate the various components of the machine.
Two parallel spaced booms 1 are mounted at one of their ends on the base B and an elongated bridge structure 3 extends perpendicularly between the booms 1 being connected to the latter so that it can be displaced bodily along the booms while being kept perpendicular. The booms 1 and the bridge 3 can be pivoted as an assembly from an inoperative position, as shown in FIG. 1, where the bridge 3 stands above the support base B, to an operative position where the boom and bridge structure assembly are swung outwardly of the support base B for cutting a curbstone, sidewalk or the like, as shown in FIGS. 3 and 4.
With particular reference again to the inoperative position of the boom and bridge structure assembly, it is not quite that shown in FIG. 1 but the position where the booms 3 are swung further rearwardly so as to butt against the ends of resting arms 5 that extend from stationary posts 7 projecting upwardly from the support base B.
A carrier 9, having a concrete-cutting saw 11 rotatable about an axis generally normal to the carrier, is mounted on the bridge structure 3 so that it can be displaced along either face 17 or 19 (FIG. 4) of structure 3, this movement being along one way or the other of a first direction of displacement of the carrier and, of course, of the saw 11 mounted thereon.
Provision is also available to displace the saw 11 in a second direction which is perpendicular to the first direction.
With the above general description in mind, when the cutting apparatus stands in the positions of FIGS. 3 or 4, the rotary saw 11 is advanced first in the second direction along arrow a through the curbstone 13, or arrow b through the sidewalk 15, to cut a transverse slot. It is then moved in the first direction to cut a central slot determining the elongated central extent of the drive-in passage. It will be noted, in this respect, that the first face 17 and the second face 19, opposite face 17, make therebetween a predetermined angle α equal to the desired angle of incline of the ramp across the sidewalk 15.
The bridge structure 3 is made up of a central section 21 (FIG. 2), essentially between the two booms 1, and terminal sections 23 each on one side of the central section 21 an in the extension thereof. As shown in FIGS. 5 and 6, the sections 23 can be pivoted upwardly with respect to the central section 21 so that by moving the carriage 9 and its saw 11 to the free end of one terminal section 23, the then inclined saw can be driven across the curbstone 13 or sidewalk 15 and then toward the central section 21 to produce an inclined slot joining the central slot of the curbstone sidewalk whereby to produce the terminal or lateral inclined extent of the drive-in passage.
When the inclined slot is finished, the saw is removed, the bridge structure 3 lifted and the terminal section 23 lowered and brought into alignment with the central section 21. The carrier and saw are driven to the other end of the bridge structure and onto the other terminal section 23 where the same operation is made to produce the second terminal cut thereby completing the drive-in passage.
As shown in FIG. 7, the bridge structure 3 is provided with a turn-table 25 suitable to allow the carrier 9 to move between faces 17, 19.
DETAILED DESCRIPTION
Each boom 1 is pivoted, at 31, to the lower end of a leg 29 which is an integral part of a generally triangular bracket 27 of which the post 7 is one of the side members. Pivotal movement of the two booms 1 is obtained by means of a pair of power jacks 33 (hydraulic or pneumatic) each extending between one post 7 and one boom 1, intermediate the ends thereof. In order that the boom and bridge assembly be swung to operative or inoperative position, it is obvious that the two jacks 33 are to be operated in synchronism.
The free end of each boom 1 is provided with a levelling jack assembly made up of a telescopic standard 35 and a power jack 37, the operating rod of the jack 37 and the sliding rod of the standard 35 being of course connected to the same base plate 39. Similar jack assemblies 41 are provided at either end of the support base B mainly for stabilizing the base and, of course, the relevant end of the boom and bridge structure assembly. As to the jack assemblies 35, 37, they must of course be adjusted according to the level condition of the lot on which the base plates 39 lie, on the side of the curb 13 or sidewalk 15 opposite the paved road or street on which the jack assemblies 41 are set. In either the case of FIG. 3 or FIG. 4, the intent is to place the booms 1 into a generally horizontal common plane.
Referring now particularly to FIGS. 1 and 5, the central section 21 of the bridge structure 3 is made up of a series of inverted T cores 43 each having a central stem 45 and a pair of lateral bars 47, 47' extending in opposite directions from the stem 45 and making between them an angle which is supplementary to the previously mentioned angle α, particularly shown in FIG. 4. On the face 17 of the bridge structure 3, there are provided top and bottom elongated rail members 49, 49' secured over the top and bottom surfaces of the lateral bars 47. In a similar manner, on the second face 19 of the bridge 3, there are provided a pair of elongated rails 51, 51' secured respectively on the top and bottom surfaces of the lateral bars 47'. The arrangement is such that the outer faces of the rails 49, 49' lie in a common first plane and the outer faces of the rails 51, 51' lie in a common second plane, the first and second planes making the aforesaid angle α, as best illustrated in FIG. 4. Finally, the ends of the central stems 45 are connected to a longitudinal elongated cylindrical bar 53, in the case of the central section 21. On the other hand, the said ends of the central stems 45 are, in the case of the terminal sections 23, fixed to square hollow bars 55.
Corresponding to each end of the central section 21 is a bearing structure for the cylindrical bar 53. This structure is made up of a pair of channel members 57, 59 secured together to define an inner housing inside of which there is fixed a square bearing block 61 having a central through bore into which the relevant end of the cylindrical bar 53 journals. As best illustrated in FIG. 6, the cylindrical bar 53 extends beyond the bearing block 61 and its transverse flat radial face is secured to the lower end of an upstanding web 62 which is part of an L-shaped bracket 63 having a pair of spaced lugs 65 of which one is connected to the web 62 by means of a brace 67. The spaced lugs 65 straddle the square hollow bar 55 of the relevant terminal section 23 of the bridge structure 3, being connected thereto by a pivot 69 which can be of the bolt and nut type. It should be pointed out here that the square bar 55 is integral part of the terminal section 23 which is identical in construction to the central section 21 except that the top member is a square hollow bar 55 as opposed to the cylindrical bar 53 of the central section 21. To be noted also is the fact that the said cylindrical bar 53 is secured to the back of the web 62 of the bracket 63 but the square bar 55 is not, so that, by means of a conventional power jack such as 71 in FIG. 5, the terminal section 23 may be angularly displaced with respect to the central section 21.
Channel 59 has the web thereof fixedly secured to the bottom of a square sleeve 73 slidably mounted on the relevant boom 1 of likewise square cross-section so as to be freely insertable into the sleeve 73. Note should be taken here that the web 62 of the bracket 63 is not secured to the side of this sleeve 73, as clearly illustrated in FIG. 6.
One flange 75 of channel 57 extends beyond the sleeve 73, as best shown in FIG. 5. To the outer end of this flange 75 is secured an operating lever 77 facing a like lever 79 of which one end is secured to the cylindrical bar 53 of the bridge structure central section 21. The upward ends of the operating levers 77, 79 are interconnected by a power jack 81.
Whenever power jack 81 is operated, let us say shortened, the operating lever 77 stays stationary as it is ultimately connected to the sleeve 73 of the boom 1 while the lever 79 causes clockwise rotation of the cylindrical bar 53 as well as like rotation of the terminal section 23 since the latter is solid, in this respect, with the central section 21 through its connection to the L-shaped bracket 63 secured to the end of the cylindrical bar 53.
As aforesaid, the advantage of this construction is to place the saw 11 at an angle other than the predetermined angle α between the faces 17 and 19 where the sidewalk is either narrower or wider than conventional sidewalks. Also, this possibility of oscillating the bridge structure 3 may be found useful as a final adjustment of the saw 11 where its levelling may not be fully attained by the use of the jack assemblies 35, 37 in view of the poor level condition of the lot inside the curbstone or sidewalk.
Referring now to FIGS. 2, 4 and 7, bodily displacement of the bridge structure 3 along the booms 1 is obtained by means of a pair of synchronously operated jacks 83 of which one end is connected to the sleeves 73 and the other ends to pivots 85 on the booms 1, located adjacent to the pivots 31 of the said booms.
Referring to FIG. 5, it is pointed out that the operating levers 77, 79 will normally be held apart by a lock bar 87 having laterally projecting pins 89 at the ends thereof insertable into receiving holes 91 at the outer ends, respectively, of the operating levers 77, 79. When the levers 77, 79 are so set, the faces 17 and 19 of the bridge structure 3 (FIG. 4) will make the aforesaid angle α. When this angle has to be changed, the lock bar 87 is removed and the levers 77, 79 operated to place the saw 11 at the selected angle at which time the levers 77, 79 may be locked again in any suitable ways.
Referring now to FIGS. 8 and 9, the carrier 9 has a generally T-shaped platform 92 over which is mounted a hydraulic or pneumatic motor 93 driving the saw 11 through a gear transmission 95 (FIG. 9) contained in a housing 97 fixed to and depending from beneath the platform 92.
Along the edges of the platform 92, there are provided two pairs of spaced flanges 99, 99' defining therebetween passages into which are received two rails 101 over the top of which are provided racks 103, the rails 101 and their racks 103 being part of the means for mounting the carrier 9 and its equipment on the bridge structure 3.
Within the aforesaid passages between the flanges 99, 99' are provided a series of pairs of rollers 105 pivotally mounted, in any known manner, on the said flanges 99, 99'. These rollers 105 are so located as to ride on the rails 101, on either side of the racks 103 thereby providing a means of allowing displacement of the carrier 9 and its equipment along a second direction which is perpendicular to the first direction mentioned above corresponding to the longitudinal direction of the bridge structure 3.
Means are of course provided to allow the said carrier displacement in the second direction, along arrow c. Such means, as shown particularly in FIGS. 8 and 9, comprises a rotary axle 107 supported by a pair of brackets 109, disposed on either side of the previously mentioned motor 93, being secured to and upstanding from the central platform 92 of the carrier 9. Rotary pinions 111 are provided at the ends of the axle 107 and are in mesh with the respective racks 103 of the rails 101. A further motor 113, mounted on one of the brackets 109, drives a worm 115 in mesh with a gear (not shown) fixed to the axle 107.
It will thus be understood that operation of the motor 113 causes, through the worm and gear arrangement aforesaid, rotation of the axle 107 and pinions 111 thereby causing displacement of the carrier 9 and its equipment along the said second direction.
As mentioned above, the rails 101 are part of the means for mounting the carrier 9 on the bridge structure 3. Such means further comprises a channel-shaped bracket 117 having a web 119, parallel to the first face 17 of the bridge structure 3, and two flanges 121, 123, this bracket 117 thus defining an inner chamber 125 into which the rails 49, 49' are disposed. On either side of the latter rails 49, 49', are rollers 127 mounted for free rotation on the flanges 121 and 123, within the housing 125. These rollers are mounted so as to ride freely on the opposite faces of the upper and lower rails 49, 49', the latter rails thus constituting means for holding the mounting means on the bridge structure 3.
It will be noted that the rails 101 are secured, at one end, at the lower end of the web 119 of the bracket 117, being further braced into position by inclined struts 129 connected at one end to the outer ends of the rails 101 and, at the other end, to brackets 131 secured at the upper end of the web 119. As shown, additional rollers 133, rotatably mounted on the said brackets 131 are adapted to ride on the top surface of the top rail 49 whereas bottom rollers 135, similarly mounted at the bottom of the bracket 117, freely ride on the bottom surface of the lower rail 49'.
The means for driving the aforesaid channel assembly in the first direction along the bridge structure 3 includes a shaft 137 (FIG. 9) mounted for rotation within chamber 125 and on the top and bottom flanges 121, 123. On this shaft 137 is fixed a gear 139 (FIG. 8) in mesh with a worm 141 driven by a motor 143 (hydraulic or pneumatic) secured outwardly of and on the web 119. A further gear 140 is mounted on the shaft 137 and at the lower end thereof which meshes with a rack 145 provided on the outer face of the lower rail 49' (see FIG. 5).
When the motor 143 is energized, it drives the shaft 137 into rotation which consequently rotates the lower gear 140 which is in mesh with the rack 145 thereby causing displacement of the bracket 117 and the equipment connected thereto including the carrier 9 and the saw 11.
Thus, there has been provided means for displacing the saw in the said first direction, along the bridge structure 3, and the second direction which is perpendicular to the first direction by having the carrier 9 move along the rails 101.
As pointed out above, the upper and lower rails 49, 49' of the bridge structure 3 constitute a holding means for retaining the bracket 117 thereon with its rolling equipment and, as a consequence, the rails 101 and the carrier 9 and the equipment mounted thereon.
The same holding means is provided on the face 19 of the bridge structure 3, opposite the first face 17, in the form of the previously mentioned upper and lower rails 51, 51' (FIG. 5). The said lower face 51' further has a rack 145' allowing the displacement of the bracket 117 and its assembly. In order that the carrier 9 and the carrier mounting means can be moved from face 17 to face 19 and vice versa, use is made of the aforementioned turn-table 25 (FIG. 7).
This turn-table takes the form of a short half section of bridge structure 3. It is made up of a pair of horizontal parallel rails 149 and 151 (FIG. 10) of the same cross-section and same vertical spacing as rails 49, 49' (or 51, 51') and integrated together by vertical spacing stems 153,155 and 157. Connecting pins 159 project from the terminal faces of the rails 149, and 151, at either end thereof. These are intended to fit into receiving bores 160 (FIG. 5) and 161. As illustrated in FIG. 10, the turn-table 25 is constructed to fit selectively at the end of the rails 49, 49' or 51, 51' so that the rails 149, 151 may constitute continuations thereof, allowing the carrier 9 to be moved on the turn-table 25. Shifting of the turn-table 25, with carrier 9 thereon, is obtained by the following transfer assembly.
The latter is constituted by a cylinder base 163, secured to the square bar 55 of the terminal section 23, into which fits the post 165 of a jib 167 having a horizontal arm 169 at the end of which one end of a rope 171 hangs. The other end of the rope 171 is secured to a support bar 173 removably secured by screws 175 on top of the flange 121 of the channel bracket 117 (FIG. 9). Normally, the turn-table 25 is secured at the end of terminal portion by a bolt and nut assembly 177.
When the carrier 9 is to be moved from face 17 to face 19 of the bridge structure 3, the bar 173 is secured on the flange 121; the lower end of the cable 171 fixed to the bar 173 (in any known manner) the bolt and nut assembly 177 removed and the turn-table 25, with the carrier 9 thereon, pulled manually to be freed from the terminal section 23. It is then rotated by 180, again manually, and the connecting pins 159 inserted in the relevant bores 161 of the face 19. The bolt and nut assembly 177 is thereafter mounted to secure the turn-table 25 in the extension of face 19. | 4y
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This application relates to portable, foldable, wireless signal-following trackable carts which may be utilized as golf carts, as grocery carts, as supply carriages or as delivery vehicles, farm vehicles/equipment and in medical facilities for tracking transportation therewithin, and is based upon our U.S. Provisional Patent Applications No. 61/628,039, filed Oct. 21, 2011, and 61/633,359, filed Feb. 9, 2012, each being incorporated herein by reference in their entirety, and our co-pending brother U.S. Patent Application number (FoldableCart-10NonProv) co-filed herewith on 15 Aug. 2012 also incorporated herein by reference in its entirety
DISCUSSION OF THE PRIOR ART
Foldable and collapsible carts and particularly collapsible golf carts have been around for many years. Examples may be seen for instance and U.S. Pat. No. 5,749,424 to Reimers; U.S. Pat. No. 4,793,622, to Sydlow; and U.S. Pat. No. 4,418,776 to Weirick. Some of these carts are even self powered, as for example U.S. Pat. No. 4,106,583 to Nemeth and of course the “Segway”™ vehicle shown in U.S. Pat. No. 7,958,961 to Schade. These prior art carts are limited in their foldability and the collapsability, wherein their ultimate collapsed size would not permit them for instance to be carried aboard an airliner and stored in an overhead compartment. Further, the prior art fails to disclose a uniquely trackable, user-followable, collapsible cart as identified herein as the present invention.
It is thus an object of the present invention to overcome the disadvantages of the prior art.
It is a further object of the present invention to provide a mobile four wheeled cart arrangement capable of multiple down-size foldings, capable of minimal storage requirements.
It is yet a further object of the present invention to provide a mobile cart which is capable of tracking (following) a user behind that user yet staying within/along the same exact path the user has taken.
It is yet another object of the present invention to provide an autonomous mobile cart which is capable by a first tracking means, of following the path of a user responsive to and according to a transponder carried by and controllable by the user.
It is still yet a further object of the present invention to have the cart circumnavigationally avoid obstacles in its path by a second automatic, directional control means.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a motor driven, autonomously directed and controlled, foldable cart assembly which articulates from a fully opened, supportive frame assembly into a compact and carryable mechanism which in one preferred embodiment could be stored for example, as a “carry on” for storage for example, in an overhead bin in an airliner, within a linear length of about 45 inches.
The foldable cart assembly of the present invention comprises a lower base frame of aluminum or magnesium aluminum alloys having a first or front end and a second or rear end. The lower base frame in a first embodiment comprises a rail arrangement extending longitudinally from the front end to the rear end thereof. A pivot means is arranged generally at a midpoint of the base frame. A transverse axle member extends across the rear end of the lower base frame. A free wheeling coaster wheel is pivotally supported at each end of the rear end transverse axle member.
The lower base frame has the pivot arrangement along a mid-portion thereof, to permit articulation thereof. The front end of the lower base frame has an axle arrangement extending thereacross. A rotatably empowered, independently controlled wheel is arranged at each end of the front end's transverse axle arrangement.
Each independently controlled wheel at each end of the transverse axle arrangement is independently controlled by a microprocessor as to each wheel's speed and as to each wheel's independent direction of rotation, by each drive wheel having a computer controlled electronic drive motor thereconnected. A housing arranged supportively on the front end of the lower base frame encloses a control computer, the drive wheels' motor controls, and a power supply unit. The control computer within that housing receives information through a proper circuit, from a multiple sensor arrangement installed within the cart assembly.
A pair of upwardly directed, generally parallel, curved side bar frame members extend away from the pivot axis arrangement disposed at the mid-portion of the lower base frame arrangement. The upwardly directed curved side bar frame members have a distal end with a transverse support bar extending therebetween. This transverse support bar also functions as an interiorly tucked away carrying handle when the cart assembly is collapsed.
A pair of mid-frame members have a first (or lower) end which pivotally extend from the ends of the transverse support bar. The mid-frame members have a second (or upper) end which is attached to the mid-frame support axis. A “U” shaped handle is pivotally arranged onto the respective ends of the mid-frame support axis. A tightenable knob or hub is arranged at the juncture of the mid-frame members and the U-shaped handle so as to permit the adjustable securement into a fixed position that U-shaped handle with respect to the parallel, upwardly directed (during cart assembly use) mid-frame members, or into a down-folded orientation during carrying or storage of the cart assembly.
The lower base frame member has a strap arrangement to secure any baggage such as, for example, a golf club bag.
A generally L-shaped bracket is attached to a midpoint of each of the upwardly directable frame members and extend toward the front end of the cart assembly, and also extend generally parallel to the lower base frame arrangement. Each L-shaped bracket is spaced transversely apart from one another a specific distance, for computational purposes of the computer control unit. These L-shaped brackets include portions of the sensor arrangement within the cart assembly. Each L-shaped bracket has a distal end with an ultrasound sensor member of the multiple sensor arrangement preferably arranged therewithin.
The ultrasound sensor member component of the multiple sensor arrangement, in one preferred embodiment is arranged on/in the cart assembly for example, to detect tracking targets such as the user holding a tracking target device (handset), obstacles including sand pits, water and any sort of travel-blocking entity. A second sensor member, such as for example, an RF (radio frequency) sensor member, may also be arranged on/in the cart assembly or for example, in the housing, to function as a timer, to “set the clock” in conjunction with the monitoring of the ultrasound sensor arrangement's responses for following the ultrasound action, for ultrasound control of direction and position through the central processing unit for setting and controlling the cart assembly's direction (path) and speed. Precise tracking of positions of for example, a golfer using this cart arrangement, is accomplished by a pair of spaced apart ultrasound sensor transceivers in a phase differential manner, and by the ultrasound sensor array for detection and controlled avoidance of obstacles nearby or crossing the cart assembly's path. The ultrasound sensor arrangement is mounted in the spaced-apart manner on the frame of the cart and interacts with the RF transponder carried in a remote device by the cart's user. These transponders and the RF sensor arrangement continuously triangulate a signal between the cart and the remote device of the cart's user, so as to enable the precise tracking of a user's path by the cart assembly, because the cart's user is carrying the remote transponder.
Those ultrasound and RF transponders of the sensor arrangement are in proper electrical communication through a circuit connected with the control computer (CPU) preferably arranged within the housing which is secured at the second end portion of the lower frame member. The multi-sensor arrangement thus enables the cart assembly to autonomously follow the path of, for example, someone leading or someone directing the way, such as for example, on a golf course, with a (remote control) location-transmitting transponder handset device. The transversely separated ultrasound sensors each send and receive a common signal relative to the location transmitting remote transponder device carried for example by a golfer or the like, whereupon the control computer triangulates that differentially received and timed return signal (with the RF sensor) with the target's (transponder) angle, so as to appropriately effect the rotation of the drive wheels, both as to the rotational direction and as to the rotational speed, thereby controlling the path to be taken by the cart assembly. Once the CPU performs its calculations, it effects the driving of the powered wheels which each have a microprocessor for effecting their respective speed and rotational direction.
The ultrasound signal generator arrangement (of the two sensor configuration) is mounted on the cart, and is in communication with the remote carried handset transponder and with the central processing unit (CPU), which CPU is also in communication with the two ultrasound transponders through the CPU. The cart arranged RF transponder provides a trigger time and permits the measure of the time between the return signals of the ultrasound transponders, so as to provide the basis of the CPU to instruct the independently empowered drive wheels as to direction of rotation and to speed of rotation. The ultrasound signal communication arrangement detects tracking targets, obstacles, water, sand traps, blockages, and they also provide a measurement of distance to an item. Based upon the travel time and sound speed, the CPU continuously calculates the path and the distance between the remote device carried by the cart's user and the sensor on the cart, using triangulation, the distance and direction between the cart and the cart user (i.e. golf player) may be determined, and provides proper instructions to be transmitted to the microprocessor controlled drive wheels, to properly maneuver the cart on the field of play to follow the user's path or follow the user's inputted RF instructions into the control handset for a path for the cart to follow.
The control algorithm is based on that feedback from the sensors. By knowing the distance and direction at anytime (or all the time), the CPU keeps track of the player's walking path. For short distances, the CPU instructs the cart to closely follow the player's walking path. For longer distances, the CPU may provide commands to go to the player on a shorter path, and to follow the player within a proper distance.
The combined RF and ultrasound sensor arrangement thus provides proper feedback to the control computer (central processing unit-CPU) so that the control computer may also further control the direction of rotation and speed of each individual drive wheel so as to avoid obstructions in the path of the card assembly, yet still properly follow the location transmitting device through a non-linear path, if need be. Thus the modes of operation of the system of the present invention comprise: constant communication with user, the following of person “1” (user), and the trajectory followed, so the cart will avoid obstacles and not stray into the wrong territory, such as a pond, a tree or the like where the user would not have walked/travelled.
By way of explanation, ultrasonic range finding is use of ultrasound is also called sonar (sound navigation and ranging). This works similarly to radar (radio detection and ranging): An ultrasonic pulse is generated in a particular direction. If there is an object in the path of this pulse, part or all of the pulse will be reflected back to the transmitter as an echo and can be detected through the receiver path. By measuring the difference in time between the pulse being transmitted and the echo being received, it is thus possible to determine how far away the object is.
One aspect of the present invention is that the remote device may be instructed to send the cart towards the next position, for example, the next “hole” on the golf course by manual input of movement directions or instructions to be undertaken in real time as the cart is moving, by input means into the remote device from the user/holder of the remote device to the RF transceiver on the cart. It is to be noted that the cart may also become a push cart when the power is turned off.
A fifth or “safety” wheel is pivotally supported off of a “J”-shaped axis extending longitudinally from a pivot arrangement on the second end of the cart assembly. The fifth wheel acts so as to prevent an overturn of the cart assembly if it were going up an incline or needed further balance.
The cart assembly is articulable so as to be folded inwardly upon itself about its various pivot axes so as to be collapsible into a very compact configuration. The U-shaped handle at the upper end of the parallel frame members may be pivoted about its transverse axis so as to swing in that U-shaped handle rearwardly or forwardly as necessary. The lower base frame is foldable about its pivot arrangement located along its mid-portion. The upwardly directed frame members, having that transverse pivot axis arranged about one third of the way up from the lower base member may in itself be pivoted around that transverse pivot axis to further compact the cart assembly.
The entire cart assembly is ultimately carryable by the transverse pivot axis arranged between the upwardly directed frame members, thus functioning as a carry handle.
The invention thus comprises a foldable four wheeled load carryable cart assembly system comprising: an elongated lower base frame arrangement having a set of wheels on a first half-end thereof, and a set of empowered computer controlled drive wheels on a second half-end thereof; a plurality of pivotable frame portions extending from one side of the second half end, wherein the first half end and the second half end of the lower base frame arrangement is foldable about a generally centrally located pivot axis thereon, and the plurality of pivotable frame portions are foldable about a set of intermediate spaced-apart pivot axes to permit the cart assembly to be folded into a compact hand-carryable configuration; and wherein the cart assembly system includes a wireless user- tracking arrangement thereon, and wherein the wireless user-tracking arrangement electronically instructs an onboard central processing unit computer to control the empowered drive wheels as to rotational direction and rotational speed, to permit the cart assembly to track and follow movement of a system's user during a user's path of motion. The system includes a user-carryable wireless transponder for transmitting wireless signals about a user's location to the wireless user-tracking arrangement on the cart assembly. The tracking arrangement includes a pair ultrasound transponders arranged to communicate positional signals with the user-carryable wireless transponder. The tracking arrangement includes a radio frequency transceiver for providing timing for ultrasound signals utilized by the central processing unit computer in the cart assembly. The ultrasound sensor arrangement transmits obstacle-avoiding signals to the central processing unit computer for the cart assembly to avoid obstacles in the path of the cart assembly. The ultrasound sensors are supported in a horizontally spaced-apart configuration on one set of frame portions to provide communicated-signal triangulation capability to the onboard central processing unit computer. An independent drive motor is arranged for each drive wheel of the cart assembly.
The invention also includes a process for controlling the track, speed and direction of a collapsably foldable, central processor unit controlled, electronically motorized, individual drive wheeled, cart assembly system for use by a cart assembly user in a field of play, comprising: arranging a pair of spaced-apart wireless ultrasound transponders on a frame portion of the cart assembly; providing a carryable wireless location ultrasound transceiver device to a user of the cart assembly; sending a pair of corresponding ultrasound signals from the ultrasound transponders on the cart assembly to and receiving returned back ultrasound signals from the location transceiver device carried by a user; timing the pair of received ultrasound signals received back to the cart assembly by an onboard RF transponder; communicating the signals received by the ultrasound transponder and the RF transponder to the central processing unit computer; and triangulating the signals so as to govern the electronic instructions to the individual drive wheels for the cart assembly to follow the user carrying the transponder device. The method includes: sensing motion and direction of a remote device carried by a user of the system; instructing drive wheels on the cart pursuant to sensed direction, speed and distance of the user carrying the remote device; operating the carryable device as a remote control to instruct the cart assembly to a user-desired site. The instruction to the individual drive wheels from the central processing unit is different for each wheel. The instruction to the individual drive wheels includes an instruction to rotate at different speed from one another. The instruction to the individual drive wheels may include an instruction to rotate at different direction from one another.
The invention also comprises a collapsible wheeled load carryable autonomously mobile cart assembly system comprising: an articulable lower frame having at least two independently empowered drive wheels thereon; an articulable upper frame, with a first and a second sensor transponder arrangement thereon; and a central processing unit on the cart assembly to instruct the empowered drive wheels as to rotational requirements upon receipt of the central processing unit receiving time, direction and distance information from the first and second sensor transponder arrangement; a user carryable handset for receiving and for transmitting position signals with respect to the user and the cart assembly, wherein the first sensor arrangement consists of a pair of spaced apart ultrasound signal trasnponders for communication with an ultrasound transponder in the carryable handset. The first sensor arrangement consists of an RF signal transponder in communication with an RF transponder on the carryable handset. The RF signal transponder in the cart assembly provides a time stamp instruction to the ultrasound signals communicated to the central processing unit in the cart assembly. The articulable upper frame is divided into multiple sections for rotatable collapse into a hand carryable configuration with a collapsed lower frame therebeneath.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the tracking foldable cart assembly in an open and unloaded configuration;
FIG. 2 is a schematic representation of the control system for the cart and the remote device held/carried by the cart's user;
FIG. 3 is a flow chart relative to the schematic shown in FIG. 2 ;
FIG. 4 is a depiction of the circuit for the movement control module;
FIG. 5 is a depiction of the circuit for the sensor control module;
FIG. 6 is a representation of the circuit of the power voltage regulator module; and
FIG. 7 is a representation of the cart assembly tracking and following a user along the user's path.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings in detail, and particularly to FIG. 1 , there is shown the present invention which comprises a computer controlled, motor driven, autonomous, directed and controlled,. foldable cart assembly 10 which articulates from a fully opened, supportive frame assembly into a compact and carryable mechanism which in one preferred embodiment could be stored for example, as a “carry on” for storage, for example, in an overhead bin in an airliner, within a linear length of about 45 inches, as shown more closely, in the figures of our separate corresponding patent application, Foldablecart-10NonProv, incorporated herein by reference in its entirety.
The foldable cart assembly 10 of the present invention comprises a lower base frame 12 of aluminum or magnesium aluminum alloys having a first end 14 and a second end 16 . The lower base frame 12 in a first embodiment comprises a rail arrangement extending longitudinally from the first end 14 to the second end 16 with a collapse pivot arrangement 22 at a midpoint thereof, as may be seen in FIG. 1 . A transverse axle member 18 extends across the first end 14 of the lower base frame 12 . A free wheeling coaster wheel 20 is pivotally supported at each end of the front transverse axle member 18 .
The lower base frame 12 has the pivot arrangement 22 along a mid-portion thereof, to enable articulated collapsible-carry of the cart assembly 10 . The second end of the lower base frame 16 has an axle arrangement 24 extending thereacross. A rotatably empowered, independently controlled wheel 37 is arranged at each end of the second end's transverse axle arrangement 24 , as shown and described in our separate patent application, incorporated herein by reference in its entirety.
Each independently controlled wheel 37 at each end of the transverse axle arrangement 24 is independently controlled by a microprocessor 39 being controlled by the central processing unit computer arrangement 30 , (CPU—represented in FIG. 2 ), as to each wheel's speed and as to each wheel's independent direction of rotation, by each drive wheel 37 having its own computer controlled electronic drive motor. A housing 28 arranged supportively on the second end 16 of the lower base frame 12 encloses the control computer CPU arrangement 30 , the drive wheels' motor controls, and a power supply unit, as represented in FIGS. 2 , 3 , 4 , 5 and 6 . The control computer arrangement 30 within that housing 28 receives information through a proper circuit 33 , from a combinational sensor arrangement (UT 1 & UT 2 ) 32 and (RF 1 ) 54 , installed within the cart assembly 10 , as represented in FIG. 3 .
A generally L-shaped bracket 50 is attached to a midpoint of each of the upwardly directable mid-frame members 34 and extend toward the second end 16 of the cart assembly 10 , and generally parallel to the lower base frame arrangement 12 . Each L-shaped bracket 50 is spaced transversely apart from one another a specific distance, for computational purposes of the computer control unit 30 . These L-shaped brackets 50 include the ultrasound transponder portions of the sensor arrangement 32 within the cart assembly 10 . Each L-shaped bracket 50 has its distal end with the first ultrasound transponder 32 of the combined sensor arrangement ( 32 and 54 ), as represented in FIG. 2 .
The second sensor member 54 , such as for example, a radio frequency tramnsponder/generator (RF) may also be arranged on/in the cart assembly 10 or for example, in the housing 28 , for functioning as a timer or “clock” for the ultrasound transponders (UT 1 and UT 2 ) 32 . By knowing the distance and direction of a player at anytime and at all time, during an activity, for example, a golf game, the microcomputer 30 can keep track of the player's “G” walking path “P”, represented in FIG. 7 . For short distances, the microprocessor 30 provides instructions to the independent microprocessor 39 controlled and motor 24 driven wheels 37 to follow the golfer “G” almost exactly. For a long distances, the microcomputer may provide instructions to the wheels 37 to follow a shorter path, all based upon feedback into the control algorithm from the sensors 32 and 54 .
Precise tracking of continuous line of positions of for example, golfers using this cart arrangement, is accomplished by the ultrasound sensors (UT 1 & UT 2 ) 32 in a phase differential manner. The ultrasound sensor array 32 is utilized for detection and controlled avoidance of obstacles “ 0 ” nearby or crossing the cart assembly's path. The RF sensor arrangement 54 is mounted on the cart assembly 10 and interacts via RF signals sent and received with respect to an RF transponder in the remote handset device “T”, represented in FIGS. 1 and 2 , carried apart from the cart assembly 10 by the cart's user “G”, as may be represented in FIG. 7 . The transponder and the RF sensor arrangement continuously triangulates a signal “S”, represented in FIGS. 1 and 7 , between the cart assembly 10 and the remote handset device “T” of the cart's user, so as to enable the precise establishing and the tracking of a path “P” by the cart assembly 10 , of the cart's user “G” carrying the remote transponder “T” as represented in FIG. 7 .
Those first and second ultrasound transponders (UT 1 & UT 2 ) 32 of the sensor arrangement are in proper electrical communication through the circuit 33 connected with the control computer (CPU) 30 preferably arranged within the housing 28 which is secured at the second end 16 of the lower frame member 12 . The multiple ultrasound sensor arrangement 32 thus enables the cart assembly to autonomously follow the path “P” of for example, someone leading the way, such as for example, on a golf course, with a (remote control) location-transmitting transponder device “T”. The transversely separated first UT 1 & UT 2 sensors 32 each receive a timed common signal “S” from the location transmitting remote transponder device “T” carried for example by a golfer “G” or the like, whereupon the control computer CPU 30 triangulates that differentially received and timed (through the RF sensors time stamping) signal with the target's (transponder) angle, so as to appropriately effect the individually different rotation of the drive wheels 37 , both as to rotational direction and as to rotational speed, thereby automatically steering and thus controlling the path “P” to be followed, i.e. taken by the cart assembly 10 . Once the CPU performs its calculations, it effects the driving of the individually powered wheels 37 which each have a microprocessor controlling their respective speed and rotational direction.
An RF signal generator arrangement (RF 1 ) 54 (the second sensor configuration utilized in the present invention) is mounted in the cart assembly 10 , and is in communication with an RF transceiver RF 2 in the remote carried transponder “T” represented in FIGS. 2 and 5 , and with the central processing unit (CPU), which CPU is also in communication with the two ultrasound transponders 32 through the computer control arrangement (CPU) 30 . The RF transponder 54 provides a trigger time which permits the measurement of the time between the signals of the ultrasound transponders to provide the basis of the CPU to instruct the independently empowered drive wheels as to direction of rotation and to speed of rotation. The ultrasound signal communication arrangement (UT 1 & UT 2 ) 32 emits sound signals for radar-like detection and alerts the cart assembly 10 as to avoidance controls of tracking targets, obstacles, water, sand traps, blockages. The ultrasound signal communication arrangement 32 may also provide a measurement of distance to an item. Thus, based upon the travel time and sound speed, the CPU constantly calculates the distance between the remote device “T” carried by the cart's user and the sensor on the cart, using triangulation, wherein the distance and direction between the cart and the cart user (i.e. golf player) may be determined, and proper instructions transmitted to the microprocessor controlled drive wheels, to properly maneuver the cart on the field of play. The control algorithm instruction is based on that feedback from the sensors 32 and 54 . By knowing the distance and direction at anytime (or all the time), the computer control arrangement (CPU) 30 keeps track of the player's walking path. For short distances, the CPU instructs the cart to closely follow the player's walking path “P”, as represented in FIG. 7 . For longer distances, the CPU may be instructed to provide commands to go to the player on a shorter more direct path, and to follow the player within a proper distance.
The combined RF and ultrasound sensor arrangements 54 and 32 thus provides a proper feedback to the control computer (CPU) 30 so that the control computer may also further control the direction of rotation and speed of each individual drive wheel and also to avoid obstructions in the path of the cart assembly, yet still properly follow the location transmitting device through a non-linear path, if need be. Thus the modes of operation of the system of the present invention comprise: constant communication with user, the following of person “ 1 ” (user), and the trajectory followed, so the cart will avoid obstacles and not stray into the wrong territory, such as a pond, a tree or the like.
Another aspect of the present invention is that the remote device may be instructed to. send the cart assembly towards the next position, for example, the next hole “H” on the golf course, via RF inputted instructions from the user's carried device “T” to the RF Transceiver on the cart 10 , for communication through the CPU to the drive wheels 37 . The cart assembly may also, in a further embodiment, become a push cart when the power is turned off.
The cart assembly 10 is articulable so as to be folded inwardly upon itself about its various pivot axes 22 , 44 and 36 , so as to be collapsible into a very compact configuration. The U-shaped handle 38 at the upper end of the parallel mid-frame members 34 may be pivoted about its transverse axis 36 so as to adjustably swing in that U-shaped handle 38 rearwardly or forwardly as necessary, or to collapse the cart assembly 10 entirely into a carryable configuration. The lower base frame 12 is foldable about its pivot arrangement 22 located along its mid-portion. The upwardly directed mid-frame members 34 , having that transverse pivot axis 44 arranged about one third of the way up from the lower base frame member 12 may in itself be pivoted around that transverse pivot axis to further compact the cart assembly 10 .
The entire cart assembly is ultimately graspable/carryable by the transverse pivot axis 44 arranged between the curved side bar members 35 and the upwardly directed mid-frame members 34 , thus functioning as a carry handle, once the sections have been articulably folded onto themselves. | 4y
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BACKGROUND
The use of photovoltaic devices with systems for concentrating sunlight onto these devices has resulted in the development of methods for optimizing the efficiency and lifetime of devices operating at elevated temperatures while minimizing the losses due to grid design. Concentrator systems often consist of cones, funnels, or lenses used to reflect a wide field of incident light onto a small focal plane where a solar cell is located. These cells are often used in space applications where thermal and radiation damage due to the environment can severely reduce cell lifetime and efficiency. Werthen, J. G., Hamaker, H. C., Virshup, G. F.;Lewis, C. R., and Ford, C. W. "High-Efficiency AlGaAs-GaAs Cassegrainian Concentrator Cells," NASA Conferences Publication 2408:61-68 (Apr. 30, 1985); Amano, C., Yamaguchi, M., and Shibukawa, A., "Optimization of Radiation-Resistant GaAs Solar Cell Structures," International PVSEC 1: 845-848 (1987).
The interdiffusion of the material used as an electrical conductor with photo-active semiconductor materials from which current is collected has resulted in the development of diffusion barrier schemes to control the instability of adjacent layers. This interdiffusion, resulting in the breakdown of the structure and loss of efficiency, has plagued existing devices being operated at high temperatures. Many nitrides, borides, and carbides of early transition metals have been suggested for use as diffusion barriers with silicon. M-A. Nicolet and M. Bartur; "Diffusion Barriers in Layered Contact Structures," J. Vac. Sci. Technol., 19: 786 (1981). The use of barriers to prevent the diffusion of a Au overlying contact layer into an ohmic contact metallized layer on GaAs wafers has been discussed in J. Shappirio, et al., J. Vac. Sci. Technol. A, 3: 2255(1985). The survivability of such metallized photovoltaic devices at temperatures up to 700° C. has been explored. These cells showed significant degradation when temperature tested at 700° C., especially when tested in a vacuum. See Horne, W. E., et al., "High Temperature Contact Metallizations for Advanced Solar Cells," Final Report on Contract AFWAL-TR-84-2044, AFWAL/POOC, Wright Patterson Air Force Base, Ohio (Sept. 1981-April 1984).
The grid pattern used in photovoltaic devices contains several loss mechanisms which reduce the available power output. It is desirable to reduce the grid area as the grid blocks out light that would otherwise enter the cell. This factor must be balanced against ohmic and surface recombination losses that are reduced with greater areal coverage by the grid contacts.
The area normally illuminated on a concentrator cell is circular in nature, with the power of the incident light decreasing radially from the center. Thus, the typical grid design for solar cell concentrators has a circular pattern with radial spokes in order to minimize power loss and maximize current collection. See Gregory C. DeSalvo, Ervin H. Mueller and Allen M. Barnett "N/P GaAs Concentrator Solar Cells with an Improved Grid and Busbar Contact Design," NASA Conference Publication 2408:51-59 (April 30-May 2, 1985); Basore, P.A. "Optimum Grid-Line Patterns for Concentrator Solar Cells Under Nonuniform Illumination," IEEE Photovoltaic Conference Record 84CH2019-8: 637-642 (May 1-4, 1984).
The use of gallium arsenide (GaAs) for solar cells, and of aluminum gallium arsenide (AlGaAs) double-heterostructures in particular, has been disclosed in U.S. Pat. No. 4,547,622 and other references cited therein. Different AlGaAs layers may be used to create a back surface field (BSF) to reflect electrons toward the p-n junction, and/or to reduce unwanted surface recombination.
Even with the many known device improvements, photovoltaic structures continue to suffer efficiency losses due to mechanical and thermal stresses encountered at elevated temperatures. Cells using compound semiconductors in particular, lose their structural and chemical integrity due to decomposition, especially at the higher operating temperatures often encountered with the use of concentrator systems.
SUMMARY OF THE INVENTION
The present invention relates to a photovoltaic structure and a method of making such a structure for use at high temperatures where certain materials are employed on the surface semiconductor to inhibit interdiffusion of these materials with the conductive contact. The cell is encapsulated with a material or materials having thermal stability and which operate to seal the entire device as well as the active junction area. These materials can also have suitable antireflective characteristics when covering the photo-active region. This system is well suited for use with concentrator systems which focus a wide field of radiation onto the photo-active surface of the cell which operates at elevated ambient temperatures.
A preferred embodiment of the invention employs grid lines which run off of the photo-active surface where they can be soldered or welded to the external contacts away from the junction area. This provides increased mechanical and thermal stability of the junction area and simplifies the sealing of the junction.
In one embodiment, the conductive grid is comprised of a refractory metal. In another embodiment, a metallized layer operates to provide a low resistance contact between the conductor and the compound semiconductor surface. At elevated temperatures, this structure inhibits diffusion and thus breakdown, while minimizing resistive losses created by separation of the conductive grid from the semiconductor surface. The resulting structure permits continuous use of the cell at ambient temperatures above 300° C. When operated at such elevated temperatures, the device will self-anneal or become radiation hardened so that the photovoltaic structure will not significantly degrade under the operating conditions often found in a space environment.
Another preferred embodiment for more hostile, very high temperature applications utilizes a barrier or antidiffusion layer on top of the metallized contact layer to substantially reduce diffusion in the grid area. This layer can be any number of metals, preferably titanium tungsten nitride (TiWN) or titanium nitride (TiN), or others such as tungsten nitride (WN) and tantalum nitride (TaN), or alternating layers of these alloys. The barrier may also be comprised of other refractory nitrides or silicides. The thermal stability of these structures makes them suitable for any high temperature application in addition to use with concentrator systems.
The cell structure can be used with any suitable grid design or with any system for concentrating the incident light onto the cell, depending upon the particular application. Where the optical concentrator used with the above device creates approximately uniform illumination across the cell, alternatives to the traditional circular grid designs can maximize the cell output. One embodiment of the present invention discloses a minimized contact area with a linear grid pattern, or alternatively, a four quadrant split of the grid pattern, to optimize output.
The photovoltaic device used with the concentrator is produced using standard photolithography and deposition techniques used in integrated circuit manufacturing. The device is thus easily manufactured at tolerances yielding substantial improvements in performance under conditions of severe thermal stress.
The above and other features of the invention including various novel details of construction and combinations of parts will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular high temperature photovoltaic systems embodying the invention are shown by way of illustration only and not as a limitation of the invention. The principles and features of this invention may be employed in varied and numerous embodiments without departing from the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1(A-H) schematically illustrates the fabrication stages of the method of making a device according to the invention;
FIG. 2 schematically illustrates a cross section of one embodiment of a high temperature photovoltaic cell according to the invention;
FIG. 3 illustrates a cross section of a hetero-junction structure of AlGaAs and GaAs;
FIG. 4 schematically illustrates an energy band diagram for the heterojunction structure of FIG. 3;
FIG. 5 illustrates a light funnel with the concentrator cell; and
FIG. 6(A) schematically illustrates a four quadrant grid pattern and the off-mesa contact areas and 6(B) illustrates the small contact design of 6(A) in an exploded view.
DETAILED DESCRIPTION OF THE INVENTION
The following high temperature cell design can be fabricated using standard semiconductor fabrication techniques. A masked set of photographic plates containing images of the pattern required at the different stages of the fabrication process illustrated in FIG. 1 can be produced.
A wafer 10 of suitably doped Gallium Arsenide (GaAs) must be prepared with an appropriate diode structure 11 (FIG. 1A). A suitable structure, for example, can consist of a classical n+/p/p+ shallow homojunction structure. As disclosed in U.S. Pat. No. 4,227,941 a GaAs solar cell can have such a structure with a 1 micron thick p+ layer on a p+ bulk GaAs wafer. This is followed by a 3.5 micron thick p layer and an n+ layer that is 1500 to 2000 Å thick and sulfur or selenium doped at 5×10 18 cm -3 .
In one embodiment, the wafer 10 and structure 11 are patterned with photoresist, such that a circular area is covered for each cell on the wafer. The wafer is then etched (FIG. 1(B)) in a peroxide/hydroxide solution to a depth 12 below the level of the junction. The mesas 21 are now isolated diodes, each of which will become the active area of the final cell. FIG. 1(C) shows the wafer 10 coated with an insulating layer 13. Numerous insulators and deposition techniques can be employed. This layer 13 acts to encapsulate the junction area 21 and isolates the semiconductor surface from subsequent metal layers. The wafer is again patterned with photoresist, and the nitride or insulating layer is etched away as above in FIG. 1(D) where the areas 14 of the subsequent metal pattern will contact the wafer.
In a preferred embodiment, these contact areas 14 or windows can be made small (on the order of 3×5 microns) to minimize surface recombination in critical applications where maximum efficiency is required. The smaller window size also reduces the area where interdiffusion with the conductive grid material can occur, especially where a diffusion barrier is not used. Alternatively, the windows can be made to run the entire length of the grid pattern in less critical applications.
Of critical importance to high temperature operations is the conductive material used to collect the photocurrent and the method of contacting this material to a compound semiconductor surface. This is addressed by coating the wafer 10 with a metal layer 15 or, alternatively, with both a metal layer and a diffusion barrier (FIG. 1(E)), which are preferably very thin. These layer(s) are designed to withstand high temperatures and to make a low resistance contact to the cell, but do not necessarily have to carry large amounts of current. A current carrying metal layer 16 on top of the metallized or diffusion barrier layer 15 shown in FIG. 1(F) is used for this purpose. The use of refractory metals as conductors has improved the performance of the collecting grid at these elevated temperatures. This performance is further improved in high temperature applications by incorporating a diffusion barrier into the cell design to avoid conductor-semiconductor interdiffusion.
The thickness of the conductive layer can be increased for applications where large amounts of current must be carried. For example, concentrators generating several hundred suns of illumination would require a high current capacity.
To form the grid, the wafer 10 is masked 17 for a third time and a conducting grid pattern 16 is placed on top of the previous layer 15. The resist 17 is then stripped in FIG. 1(G), revealing the grid pattern undercoated by the high temperature metal system 15. Since the high temperature metal system covers the cell, it must be removed everywhere except underneath the conductor 16. To accomplish this task, the wafer is sputter etched. In this process, a portion of the conductor 16 is removed as well as the metallized layer 15 not covered by conductor grid 16. Since the conductor 16 is many times thicker than the high temperature metal 15, the grid pattern remains intact after the process. In FIG. 1(H) the conductor may be enclosed with insulator 19. The top layer of the diode structure (the n+layer in the case of a shallow homojunction) is etched or thinned 20 so that carriers are located as close to the active junction as possible to maximize the cell's I-V characteristics.
In a preferred embodiment of the invention illustrated in FIG. 1, the metallization scheme consists of a thin tungsten (W) layer that is 300 to 400 Å thick, which is electron beam deposited or sputtered onto the patterned wafer. Tungsten is preferred because of its good conductivity and due to the good match of its coefficient of thermal expansion with that of GaAs. This is followed by a TiWN diffusion barrier layer. The thickness of the barrier layer is preferably around 300-1000 Å thick. The thickness of the diffusion layer should be kept at a minimum due to the mechanical stress caused by the refractory nitride in use. The refractory nitrides are best deposited by sputtering at low power to minimize sputtering damage to the GaAs surface. The top metallization can be nickel and the whole structure should then be covered by a capping layer, preferably Si 3 N 4 . In one embodiment, this structure is then annealed by rapid thermal annealing to about 500°-700° C. This step anneals off fabrication damage in the cell such as sputtering damage.
Other materials may be used instead of the tungsten for metallization, such as Mo, Ni, Ti, tungsten alloys or Ta. Alternatively, silicides such as tungsten silicide or molybdenum silicide can be used. However, for cells operating at less than 100 suns a refractory metal such as W, in a layer about 2000-5000 Å thick, can be used as a conductor without any metallization layer or diffusion barrier layer. This latter embodiment provides a simpler but thermally stable system at lower incident power levels.
FIG. 2 illustrates a cross section of a preferred embodiment of a high temperature cell with a five finger conductor pattern. Note that no metallized or barrier layer is found in this embodiment. Where the conductor 16 is a refractory metal, such as W or Mo or a refractory silicide such as WSi 2 or MoSi 2 , the thermal stability of this structure permits the omission of a diffusion barrier in certain applications. An antireflection coating 27, preferably silicon nitride, is applied to generate high efficiencies for the solar spectrum anticipated. In this embodiment, the coating serves to encapsulate the active area of the cell further limiting diffusion and decomposition of the structure elements. Non-illuminated surfaces can be sealed with an insulator. The conductors 16 are shown as extending off the junction area 11. This permits the contacts to the conductive grid to be made away from the junction area, thereby reducing the thermal and mechanical stresses often encountered when contacting the grid in the junction area. Bonding off of the junction area is even more preferable at high temperatures to minimize interdiffusion and other deleterious effects.
To get higher efficiencies, another preferred embodiment utilizes the heterojunction structure illustrated in FIG. 3. This begins with a high quality p+ wafer 10 covered by a 1 to 2 micron thick AlGaAs p+ layer 22. Overlying p GaAs layer 23 should be doped at approximately 10 17 to 10 18 cm -3 for concentrator cells and be 2.5 microns to 5 microns thick. The n+ GaAs layer 24 is preferably less than 0.25 microns thick with a doping level of 1 to 3×10 18 cm -3 . An n+ AlGaAs cap layer 25 of 100-500 Å is then deposited over the n+GaAs layer primarily for surface passivation. The Al content should be high, that is, greater than 80%. The contact layer 28 of n+ GaAs is then deposited with a doping level of over 5×10 18 cm -3 . This "pillar" type structure can be about 0.1-0.5 microns thick and results in further separation of the metallic contact from the junction area. The structure will provide about 15 relative percentage points over the shallow homojunction structure efficiency. As it is unnecessary to thin the top n+ layer as in the homojunction structure, the processing for this structure is simpler and more reproduceable. The radiation hardness of these structures can also be improved by adding aluminum at concentrations of less than 10% to each of the GaAs layers. The cell structure of FIG. 3 can be used with or without a concentrator system, as any application requiring high temperature survivability is appropriate.
A further embodiment similar to that illustrated in FIG. 3 utilizes a double heterojunction structure. This structure has a p+wafer of GaAs covered with a layer of p+ AlGaAs with approximately 20% aluminum. This is followed by a layer of p GaAs and a layer of n+AlGaAs added on top of the p GaAs layer to provide the double hetero-junction. The n+AlGaAs layer is then followed by the "pillar" type structure of n+ GaAs. In this structure, the active junction is now between the n+AlGaAs and the p GaAs.
Returning to FIG. 3, the insulator 13, as in FIGS. 1 and 2, is used to define the area over which the conductor 16 is in conductive contact with pillar 28 through the layer 15. The layer 15 is comprised of a metallization layer to provide a low resistance contact with the pillar surface 28, and a barrier layer to reduce interdiffusion between the conductor and the GaAs structure. The structure is encapsulated with layer 27. The layer 27 is an antireflective coating over the photo-active surface of the cell together with a sealing layer which is opened up for bonding at the off-mesa contact to the conductor grid.
FIG. 4 schematically depicts an energy band diagram for the heterojunction structure of FIG. 3. The heterojunction between the p+ AlGaAs layer 22 and the p GaAs layer 23 provides a back surface field which acts as a minority carrier mirror to efficiently reflect electrons back toward the p-n junction. The top AlGaAs layer 25 operates to reduce the surface recombination velocity. The interface between materials of different bandgaps, as provided by these heterojunctions, provides a more abrupt interface than when simply altering the doping profile. The back surface field should preferably have a barrier height of approximately 3KT or greater where K is Boltzmann's constant and T is the temperature in degrees Kelvin.
Although the structure described uses GaAs as the active layer, other compound semiconductors such as indium phosphide or gallium alluminum arsenide can be successfully used.
FIG. 5 shows schematically how a light funnel 35 may be used in concentrating and distributing incident light more uniformly across a cell 36.
FIG. 6A illustrates the four quadrant design 37 with a magnified view of where the four quadrants meet in FIG. 6B. The magnified view shows a particular contact pattern 38 with the small rectangular windows 39 distributed along each line of the grid.
This pattern (6A) is preferred because it is easier to fabricate than conventional designs which have radial symmetry. Illumination of a conventional light concentrating system has a radial distribution, and thus the current output of the cell varies radially. In order to accomodate this, previous concentrator grid designs were radial. Under the present concentrator design the light intensity distribution is very uniform and the desire to have radial symmetry in the grid pattern loses its supposed advantage. Note that the cell design of FIG. 3 can be used with radially illuminating concentrator systems, or any other illuminating geometry as long as the grid pattern is chosen accordingly.
The cell contact pattern can be divided into four quadrants. Each quadrant consists of straight parallel lines of conductor material partially insulated from the semiconductor surface by an insulating material. The conductor paths 38 reach from the edge or perimeter 40 of the photo-active surface to the border of the quadrants. The conductor is contacted off of the photo-active surface: i.e., the conductor extends off of the cell surface to the side 37 of the junction area. By contacting the cell conductor off of the mesa, or junction area, (21 of FIG. 1B), the mechanical and thermal stresses caused by contacting the grid on the mesa are minimized. This off-mesa contact to the grid is more important when operating temperatures are high or when periodic thermal excursions above routine operating temperatures can produce stress in the junction area.
The insulator pattern contains windows 39 which define the contact area between the conductor lines and the semiconductor surface of the cell. By adjusting the size of these contact windows, one can control the level of surface recombination of minority carriers. Reducing the window size reduces the rate of surface recombination thereby improving the overall efficiency of the cell. In applications where high efficiencies are less critical, the insulator windows may extend the entire length of the conductor line across the cell quadrant. Where higher efficiencies are needed, the windows may be reduced in size and evenly spaced along the conductor lines without significant offsetting losses due to longer current paths. More importantly, the use of windows in the contacting grid will further reduce the conductor contact area with the semiconductor surfaces to further reduce the possible interdiffusion effects occurring at high temperatures.
The above structure and design provides solar cells that are stable during high temperature operation above 300°-400° C. In addition, for space applications, these cells can anneal off radiation damage normally incurred in space when operated in this temperature range.
The above design can be used in conjunction with the so-called "CLEFT" peeled film technology in PCT/US81/00439 (corresponding to U.S. Pat. No. 4,727,047, filed Apr. 6, 1981, a C-I-P of U.S. Ser. No. 138,891, filed Apr. 10, 1980) which is incorporated herein by reference. This thin, light-weight structure permits use of the structure in tandem or with a back reflective contact to improve collection of minority carriers within the active layer.
Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Other compound materials such as InP or GaAlAs, that are useful as photovoltaic materials, can be used in the claimed structure. Such equivalents are intended to be encompassed by the following claims. | 4y
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FIELD OF THE INVENTION
[0001] The present invention relates to a process for the recycling of household waste and a system therefor.
BACKGROUND OF THE INVENTION
[0002] In conventional processes, household waste that has been collected is collected and deposited in a pit. Then, the waste material is roughly crushed and fragmented in order to facilitate incineration or stocking in landfills.
[0003] Dioxins, a highly toxic group of chemicals, are produced when polyvinyl chloride (PVC) and other plastic waste are burned at temperatures below 700° C. To prevent the production of dioxins, Government regulations have been enacted. Higher costs of incineration of the waste to comply with the Government regulations have led various communes to pay more attention to the effective treatment of the waste without incineration. Stocking the waste in landfills may cause serious environmental concerns.
[0004] An object of the present invention aims at the treatment of household waste without incineration and provides a process and system for the recycling of the household waste.
SUMMARY OF THE INVENTION
[0005] According to one aspect of the present invention, there is provided a process for the recycling of household waste comprising:
[0006] converting household waste materials into products for fertilizing and/or conditioning soil.
[0007] According to another aspect of the present invention, there is provided a process for the recycling of household waste comprising the steps of:
[0008] converting an input waste that includes a portion of “combustible” waste materials of household waste into products for fertilizing and/or conditioning soil;
[0009] sorting an input waste that includes a portion of “incombustible” waste materials of household waste into various kinds of recyclable products;
[0010] sending the remainder of the “combustible” waste materials, which is inappropriate to the transformation into the soil fertilizing and/or conditioning products, to said sorting step as said input waste thereto; and
[0011] sending the remainder of the “incombustible” waste materials to said converting step as said input waste thereto.
[0012] According to still another aspect of the present invention, there is provided a process for the recycling of household waste comprising the steps of:
[0013] processing waste materials of household waste collected as “combustible;” and
[0014] processing waste materials of the household waste collected as “incombustible;”
[0015] wherein said “combustible” waste materials processing step includes the sub-steps of:
[0016] converting organic portion of said “combustible” waste materials into products for fertilizing and/or conditioning soil; and
[0017] subjecting the remainder of said “combustible” waste materials to said “incombustible” waste materials processing step.
[0018] According to a further aspect of the present invention, there is provided a system for the recycling of household waste comprising:
[0019] a first sub-system for waste materials of household waste collected as “combustible,”
[0020] said first sub-system including a cutter for cutting input waste materials into fragments of different sizes, a drier for drying said cut fragments and a separator for separating said dried cut fragments by size into a first group appropriate to products for fertilizing and/or conditioning soil and a second group inappropriate to said soil fertilizing and/or conditioning products; and
[0021] a second sub-system for waste materials of household waste collected as “incombustible,”
[0022] said second sub-system including a bag breaker for breaking bags containing waste materials to allow the waste materials to come out of said bags and a multistage separator for separating, by material, said broken bags, said waste materials coming out of said bags and said second group of dried cut fragments,
[0023] said multistage separator being operative to separate organic materials out of the waste materials being processed for the subsequent admission into said cutter of said first sub-system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 illustrates schematically a process for handling household waste.
[0025] [0025]FIG. 2 illustrates a preferred implementation of a system for practicing the process.
[0026] [0026]FIG. 3 illustrates a drier and a separator that may be used in the system.
[0027] [0027]FIG. 4 illustrates schematically a process flow that may be used in the system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0028] Household waste is typically a mixture of organic materials, such as food wastes, paper, and cellulose packaging materials, and inorganic materials, such as plastic packaging materials, fabrics, ferrous and non-ferrous objects, batteries, synthetic materials, etc. Members constituting each home or office are entrusted to separate materials that are inappropriate to incineration from the remainder in accordance with the community regulations and deposit in a pit them, as “incombustible.” The remainder of the materials of the household waste is packed, as “combustible,” in garbage bags. The waste materials that have been deposited in a pit as “incombustible” and the waste materials that have been packed as “combustible” are separately collected. According to the community regulations, for example, the waste materials to be collected as “combustible” include food wastes, paper and green wastes. Examples of green waste are grass clippings, twigs and branches. The waste materials to be collected as “incombustible” include ferrous objects, aluminum, glass and plastics.
[0029] The waste materials that have been collected as “combustible” include mostly combustible materials, but may include materials that are classified as “incombustible.” The waste that have been collected as “incombustible” include mostly incombustible materials, but may contain materials that are classified as “combustible.”
[0030] Referring to FIG. 1, the process for handling household waste is schematically shown. The process comprises a first or “combustible” processing S 1 for processing waste materials that come out of plastic bags that have been collected as “combustible” and a second or “incombustible” processing S 2 for processing waste materials that come out of plastic bags that have been collected as “incombustible.”
[0031] The first processing S 1 has a cutter stage S 1-a for cutting input waste materials into smaller fragments, a drier stage S 1-b for drying the cut fragments and a separator stage S 1-c . The separator stage S 1-c separates the dried fragments as a usable output product for soil conditioner and/or fertilizer from the remainder. The separator stage S 1-c outputs the remainder of the fragments as an inappropriate output material to products for fertilizing and/or conditioning soil.
[0032] The separator stage S 1-c separates the dried fragmented waste materials as the output product appropriate to products for fertilizing and/or conditioning soil after removing ferrous objects by an electromagnet and removing the cut fragments inappropriate to the soil fertilizing and/or conditioning products by a filter. The separated output product appropriate to the soil fertilizing and/or conditioning products includes fermentable organic waste materials excluding plastic. The output products that have been removed by the separator stage S 1-c include non-fermentable inorganic waste materials.
[0033] The fermentable organic waste materials are subject to the subsequent fermentation process to grow into products for fertilizing and/or conditioning soil. The output products that have been removed during the separator stage S 1-c are subject to the second processing S 2 .
[0034] The second processing S 2 sorts the waste materials being processed into various kinds of reusable output products such as ferrous objects, aluminum, glass, plastics. Among the waste materials collected as “incombustible”, plastic beverage containers, aluminum beverage containers, and food and beverage containers made of glass are packed in plastic garbage bags. Thus, the second processing S 2 has a bag breaker stage S 2-a prior to the subsequent multistage separator stage S 2-b . The plastic garbage bags are broken by the bag breaker stage S 2-a into plastic fragments. These plastic fragments are handled together with plastics being processed. The waste materials coming out of the broken garbage bags are sorted by the multistage separator stage S 2-b into usable output products, such as iron, aluminum, glass and plastic.
[0035] The waste materials held to be inappropriate to products for fertilizing and/or conditioning soils by the first processing S 1 are used as the input to the multistage separator stage S 2-b . The multistage separator stage S 2-b sorts the input waste materials from the first processing S 1 into the usable output products. In the multistage separator stage S 2-b , organic waste materials are separated. The organic materials from the multistage separator stage S 2-b are sent to the first processing S 1 and used as the input to the cutter stage S 1-a . The organic materials from the multistage separator stage S 2-b are subject to cutting in the cutter stage S 1-a , drying in the drier stage S 1-b and sorting in the separator stage S 1-c .
[0036] From the preceding description, it is now understood that the preferred implementation of the present invention does not rely on incineration in handling waste materials. The waste materials collected as “combustible” are grown into products for fertilizing and/or conditioning soil, and the waste materials collected as “incombustible” are sorted into various usable output products.
[0037] [0037]FIG. 2 illustrates the preferred implementation of a system according to the present invention for practicing the process. The system includes a first or “combustible” processing sub-system S 1 and a second or “incombustible” processing sub-system S 2 .
[0038] The first processing sub-system S 1 has a cutter 1 , a drier or drying equipment 2 and a separator 3 . The separator 3 is a machine for separating waste materials of different particle sizes.
[0039] Waste materials, which have been collected as “combustible,” are used as the input to the cutter 1 of the first processing sub-system S 1 . The cutter 1 cuts the input waste into fragments. The fragmented waste materials, which are the output of the cutter 1 , are sent to the drier 2 .
[0040] [0040]FIG. 3 illustrates the preferred embodiment of the drier 2 and the separator 3 . The drier 2 includes a chamber 4 , an output device 5 , a dehumidifier 6 and a deodorizing equipment 7 . The cut fragments of the waste materials are transferred to the drier 2 by a conveyer (see FIG. 2) or by a container 8 on an industrial hand cart 9 . The waste materials are admitted into the chamber 4 by an automatic supply device 10 . The automatic supply device 10 throws in the waste materials into the chamber 4 .
[0041] The temperature within the chamber 4 is held higher than 100° C. by burning of gas ejected from a gas burner 11 . An agitator 12 within the chamber 4 mixes the waste materials within the chamber to facilitate hot air drying. A bucket conveyer 14 conveys the dried output of the chamber 4 to a sieve 15 that constitutes the separator 3 of the system shown in FIG. 2. The output materials of the sieve 15 are temporarily loaded into and discharged from a hopper 16 .
[0042] Exhaust gas resulting from the hot air drying within the chamber 4 contains moisture. This moisture containing exhaust gas is introduced into the dehumidifier 6 by a moisture discharge duct 17 . Temperature of the exhaust gas introduced into the dehumidifier 6 is removed by a water flow from a cooling tower 19 to turn the moisture into water that is discharged as effluent. The moisture free exhaust gas from the dehumidifier 6 is introduced into the deodorizing equipment 7 . Odor is removed from the exhaust gas by a deodorizer 18 . The exhaust gas from the deodorizing equipment 7 is discharged into the outside by an exhaust duct 21 .
[0043] The materials discharged from the hopper 16 are carried into a fermentation-equipment 20 (see FIG. 2), which undergoes fermentation of the input material The output products of the fermentation-equipment 20 are used for fertilizing and/or conditioning soil.
[0044] The residual materials that have failed to pass through the sieve 15 are transferred to the second sub-system S 2 .
[0045] The second sub-system S 2 includes a bag breaker 23 and a multistage separator 22 . According to this preferred implementation, the second sub-system S 2 further includes a cutter 30 and an electrostatic separator 32 for refined separation of fragments of different materials.
[0046] [0046]FIG. 4 illustrates schematically a process flow of the second sub-system S 2 . According to this illustrated flow, the input waste materials collected as “incombustible” in plastic garbage bags 36 are included in the input materials of the second sub-system S 2 . The plastic bags 36 are thrown into a hopper 24 of the bag breaker 23 . If desired, the waste materials may be fed as the input to the multistage separator 22 (see FIG. 2) after being taken out of the plastic bags 36 .
[0047] Referring to FIG. 4, a cutter 25 within the hopper 24 breaks up each of the plastic garbage bags 36 into fragments. The bag fragments 36 are separated from the waste materials and conveyed to the cutter 30 . The waste materials coming out of the bags 36 drop on a sieve 34 . The sieve 34 separates the input waste materials of different sizes. Small size waste materials I that have passed through the sieve 34 drop on a vibratory feeder 26 . The vibratory feeder 26 is a vibrating conveyer with a relatively low frequency and large amplitude of motion and sends the small size waste materials I in an inclined downward direction. During this motion, soil and cullet A are removed and a separator 27 for separating and removing cylindrical cells B from the waste materials that have been dropped on the vibratory feeder 26 . This separator 27 removes the cells B by comparing the shape of each cell with a shape pattern. The small size waste materials I without soil and cullet A and cells B are sent to the cutter 30 .
[0048] The waste materials with large sizes that will not pass through the sieve 34 slides down a slope of the seize 34 . Ferrous objects C are removed with a suspended separator 28 over the slope of the sieve 34 .
[0049] The remainder G of the large size waste materials drop down to a weight separator 29 past an aluminum separator 35 . The aluminum separator 35 removes aluminum objects F. The ferrous objects C and aluminum objects F are reduced in volume by a volume reducing equipment 33 . The weight separator 29 separates, by weight, the input large size waste materials G into beverage and food containers made of glass H and the remainder J. The remainder J of waste materials of large sizes is introduced into the cutter 30 . The cutter 30 cuts the input broken garbage bags 36 , small size waster materials I and the large size waste materials J into fragments and discharge the cut fragments onto a high performance aluminum separator 31 . This separator 31 removes aluminum objects K. An electrostatic separator 32 separates the cut fragments without aluminum objects K into paper D and plastic fragments E.
[0050] Referring also to FIG. 2, the multistage separator 22 of the second sub-system S 2 is connected to the cutter 1 of the first sub-system S 1 by a conveyer line 37 . More particularly, combustible waste materials like paper D that are separated by the electrostatic separator 32 of the multistage separator 22 are collected in a combustible waste collecting portion, and this combustible waste collecting portion is sent to the cutter 1 by the conveyer line 37 .
[0051] In other words, the cutter 1 of the first sub-system S 1 receives, as an additional input, combustible waste materials that have been sent from the second sub-system S 2 by the conveyer line 37 . Subsequently, the cut fragments discharged by the cutter 1 are dried and separated and then introduced into fermentation-equipment 20 . Incombustible inorganic waste fragments that have been separated are introduced back into the multistage separator 22 of the second-sub-system S 2 .
[0052] Referring back to FIG. 4, if the plastic fragments E that have been removed by the electrostatic separator 32 contain rubber, leather or fabric, the rubber, leather and fabric are removed and sent to a waste processing center over a number of communities.
[0053] In the preferred implementation, the multistage separator 22 handles household waste materials collected as “incombustible” and the drier 2 handles household waste materials collected as “combustible.” The first or “combustible” processing sub-system S 1 and the second or “incombustible” processing sub-system S 2 cooperate with each other to work as a single system. The incombustible inorganic waste materials from the drier 2 are fed to the multistage separator 22 , while the combustible waste materials from the multistage separator 22 are fed to the drier 2 . The combustible components of the household waste are converted into products for fertilizing and/or conditioning soil, and the incombustible components are separated for reusable products. This facilitates recycling of the household wastes.
[0054] In the previous description, the heating within the chamber 4 relied only on the gas burner 11 . The garbage within the chamber 4 can be dried within a shortened period of time (3 to 6 hours) with multi-heating using far infrared radiation, heat conduction (120° C.) and agitation with hot air (about 280° C.). Using this multi-heating, germs within the garbage are killed, and thus the dried output products may be used as prompt. The use of this prompt will not cause any environmental pollution. Using soft ceramics as the deodorant 18 within the deodorizing equipment 7 is effective in eliminating offensive odors of the gas discharged during the drying process.
[0055] From the preceding description, it will now be appreciated that household waste can be handled without replying on incineration and depositing in landfill. It will also be appreciated that the preferred implementations according to the present invention comply with recommended waste management without any incineration, any deposition in landfill, any dumping, any offensive odors and any unnecessary transportation.
[0056] The above-described preferred implementations of the present invention are example implementations. Moreover various modifications to the present invention may occur to those skilled in the art and will fall within the scope of the present invention as set forth below. | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to d.c. - a.c. inverter circuitry connectible at its input to a d.c. power source and at its output to a fluorescent lamp. More particularly, it relates to such circuitry that enables a standard type of fluorescent lamp to be operated from a low voltage battery with a high degree of efficiency, i.e., with minimum electrical power input for a given level of light power output.
There are many applications where it is desirable to have a light source that is capable of operating from a convenient d.c. power source, such as a battery. The incandescent lamp is often used as a means of converting electrical power from a battery into light power (illumination). It is well known in the art, however, that an incandescent lamp is a very inefficient means of converting electrical energy into visible light. Approximately 6% of the electrical energy supplied to an incandescent lamp is converted into visible light, the other 94% being used up in the generation of heat with a small accompanying amount of invisible ultraviolet light.
When the supply of electrical energy is limited, as in the case of a battery-operated lamp, it is desirable to achieve maximum operating efficiency so that the lamp can be operated for the longest period of time before the supply of electrical energy is exhausted. It is also well known in the art that a fluorescent lamp is approximately four to five times more efficient than an incandescent lamp. Because of its higher efficiency, the fluorescent lamp has the potential to out-perform the incandescent lamp in those instances where efficiency ranks as an important operating parameter. In order to take full advantage of this remarkable potential, however, it is essential that transistor circuitry used to supply power to the fluorescent lamp does not itself operate inefficiently. To this end, it has heretofore been recognized that the circuitry should at least take into account that the gas mixture in a fluorescent lamp must first become highly ionized in order to cause the lamp to emit visible light, that the application across the lamp of an a.c. voltage rather than a d.c. voltage makes it possible to use a purely reactive element as a current limiting impedance (ballast) in order to minimize energy loss relative to the loss experienced with the use of a resistive ballast, and that the lamp impedance will remain fairly constant if the frequency of the a.c. voltage applied across the lamp has a period of oscillation shorter than the average recombination period of the positive and negative ions, yet not so short as to unduly reduce the effectiveness of transistor switching. It has moreover been recognized that heating at least one cathode in the lamp just prior to or while the starting voltage is being applied will facilitate the ionization process.
SUMMARY OF THE INVENTION
It is the principal aim of the invention to provide transistorized circuitry which functions to convert power from a d.c. power source into a.c. voltages and currents particularly well-suited for operating a standard type fluorescent lamp at optimal efficiency.
Another aim of the invention is to provide such aforesaid circuitry with the function also of supplying transient voltages and currents only during the initial ionization of the lamp, these transients going to zero once the lamp has been started, thereby contributing to overall efficiency.
A further aim of the invention is to provide either of the aforesaid circuitries with a power transistor arranged so that current in the lamp also flows through the base of the power transistor causing the base drive to the transistor to be self-regulating, thereby contributing to overall efficiency.
According to one aspect of the invention, there is provided a fluorescent lamp circuit comprising:
(a) a fluorescent lamp of the type having a preheater which serves also as one of two spaced electrodes between which arcing in the gas filling of the lamp is to be initiated to ionize the gas filling with the aid of free electrons thermionically emitted therein by said preheater;
(b) a first sub-circuit for driving current through said preheater; and
(c) a second sub-circuit for driving current through said lamp between said spaced electrodes once the operation of said second sub-circuit has been started by a turn-on current supplied thereto;
(d) said first sub-circuit being arranged to commence energization of said preheater and continue such energization only for a time period of limited duration from a low-voltage d.c. power source upon a connection being made of said lamp circuit to said source, said first sub-circuit being further arranged to supply turn-on current during said period to said second sub-circuit sufficient to start its operation;
(e) said second sub-circuit, upon having its operation started, being arranged to operate thereafter as an inverter energized by said d.c. power source to drive high frequency alternating starting current through said lamp via said electrodes to ionize said gas filling within said time period and regeneratively to maintain its said inverter operation at a reduced voltage across said lamp after ionization takes place so as continuously to drive high frequency operating current through said lamp, the operating conditions of said second sub-circuit being self-adjusting in response to said starting and operating currents to compensate for changes in the respective peak values of said currents from predetermined optimally efficient magnitudes.
According to another aspect of the invention, there is provided a fluorescent lamp circuit comprising:
a pair of input terminals for connection across a low voltage d.c. power source;
a fluorescent lamp having a pair of electrodes at opposite ends of a gas-filled envelope;
a transformer having a ferromagnetic core on which a primary winding, a first secondary winding and a second secondary winding are wound, said secondary windings being connected in series with one another in voltage aiding relationship;
a bipolar transistor which, when conductive, connects said primary winding across said pair of input terminals;
first biasing means which, in response to the connecting of said pair of input terminals across said power source, supplies forward driving current through the base of said transistor to cause said transistor to become partially conductive so that current from said power source begins to flow through said primary winding;
means connecting one side of the serially-connected secondary windings to one end electrode of said fluorescent lamp and the other side through the base of said transistor via the path of said forward driving current thereof to the other end electrode;
a diode connected across said forward driving current path of said transistor in anti-polarity relationship therewith; and
a resistor connected from a common connection point of said serially-connected secondary windings to a common connection point of said diode, said forward driving current path of said transistor and one of said pair of input terminals;
said resistor, diode, secondary windings and the impedance of said fluorescent lamp providing biasing conditions for said transistor which cause the conductivity of said transistor to undergo successive time cycles upon said pair of input terminals being connected across said power source, one half period of each time cycle being characterized by a rise and fall of transistor conductivity from zero to full and back to zero, and the other half period by a continuing zero conductivity, each cycle being initiated by said first biasing means at least during the first few seconds of operation, whereby voltages of one polarity are induced across said secondary windings by said primary winding to drive current of one direction through said fluorescent lamp via the base of said transistor as said transistor experiences its conductive half cycle, and voltages of opposite polarity to said one polarity develop across said secondary windings to drive current of the opposite direction through said fluorescent lamp via said diode as said transistor experiences its non-conductive half cycle, the flow of lamp current via the base of said transistor effecting an automatic adjustment of the transistor base drive to regulate said lamp current.
According to a further aspect of the invention, the fluorescent lamp circuit is combined with a housing comprising:
(a) a hollow tubular body of light-transmissive rigid material in which the fluorescent lamp of said lamp circuit is centrally disposed with peripheral clearance thereabout, the length of said tubular body exceeding the length of said fluorescent lamp so that opposite end portions of said tubular body are left unoccupied by said fluorescent lamp, one such end portion containing the first and second sub-circuits of said lamp circuit in a common protective encapsulation from which electrical output leads of said sub-circuits emerge and connect to terminal pins provided at the ends of said fluorescent lamp for the driving currents to be supplied by said sub-circuits;
(b) first and second cup-like end caps of elastomeric material removably cupped over said one end portion and the other end portion, respectively, of said tubular body, each with a watertight interference fit, said first end cap having a passage extending through its base from its cup chamber to the surrounding atmosphere; and
(c) an elongated two-conductor cable having one end thereof electrically connected within said cup chamber to electrical input connections of said first and second sub-circuits emerging from said common protective encapsulation thereof, said cable including a first length portion proximate its said one end and coextensively disposed in said passage so that a relatively longer remaining length portion extends into said surrounding atmosphere to permit electrical connection of the other end of said cable to a remotely-located low-voltage d.c. power source, said cable havng an elastomeric insulating jacket of a cross-sectional shape which complements that of said passage and which, along said first length portion, makes a watertight interference fit with said passage.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the present invention may be more fully understood, it will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a schematic circuit diagram of a prior art fly-back d.c. - a.c. inverter circuit having some features in common with the preferred embodiment of the circuitry according to the invention;
FIG. 2 is a schematic circuit diagram of the preferred embodiment of the circuitry according to the invention; and
FIG. 3 is a front elevational view in section illustrative of a combination, in accordance with the invention, of a fluorescent lamp circuit with a watertight housing.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The prior art fly-back d.c.-a.c. inverter depicted in FIG. 1 uses a single bipolar transistor 1 operating from a low voltage battery 3 to power a load 5 which requires a high voltage, low current supply. The emitter-collector path of transistor 1 is connected in series with a transformer primary (or input) winding 7 wound on a first secondary (or hold) winding 11 and a second secondary (or ouput winding 13. Transistor 1 begins to conduct as a result of a forward bias current caused to flow through its base-emitter path by way of a resistor 15 when a main supply switch 17 in a series connection with battery 3 across circuit input terminals 19, 21 is closed. A positive voltage then begins to build up across primary winding 7 and, by induction, across each of secondary windings 11, 13. The voltage induced in first secondary winding 11 causes additional forward bias current to flow through a second resistor 23 and the base-emitter path of transistor 1, thereby rapidly making the transistor fully conductive, i.e. fully ON. Second secondary winding 13 is connected solely across load 5, so that the induced voltage applied to load 5 rises positively with the rise in primary voltage.
Immediately after transistor 1 becomes fully conductive, a slight decrease occurs in the primary voltage due to increased transistor saturation voltage which itself is due to a linearly increasing magnetizing current of the transformer beginning with the conduction of transistor 1. The decreased positive primary voltage is reflected in secondary windings 11, 13; and the decreased voltage across first secondary winding 11 decreases the base drive of transistor 1, resulting in a further increase in the ON resistance of transistor 1. This causes a further decrease in positive primary voltage and, as the process is regenerative, transistor 1 is rapidly turned OFF. Now, due to the inductive natures of windings 7, 11 and 13, the polarities of the winding voltages will reverse. At this time, a negative current will flow through first secondary winding 11, resistor 23 and a diode 25 which is connected in parallel anti-polarity relationship with the base-emitter path of transistor 1, such current providing a back bias which holds transistor 1 in its turned OFF condition. Meanwhile, negative current flowing through secondary winding 13 as a result of the voltage polarity reversal drives the voltage across load 5 to a high peak negative value. This current continues to flow until the energy stored in the magentic field of the transformer while transistor 1 was ON is dissipated in load 5. The negative current in first secondary winding 11 continues to flow in OFF biasing relationship to transistor 1 until such current has become so small that diode 25 ceases to conduct, whereupon forward bias current flowing from battery 3 through resistor 15 and the base-emitter path of transistor 1 again causes the transistor to begin to conduct and the preceeding cycle repeats.
Should load 5 in FIG. 1 be a fluorescent lamp of the preheat type and should provision be made for energizing at least one preheater of the lamp upon connecting the inverter circuit to battery 3, the resulting free electrons thermionically emitted into the gas filling will so lower the lamp impedance that an arc will be struck across the electrode gap of the lamp by one or more of the successive cycles of positive and negative voltages applied across the lamp by second secondary winding 13, whereby the gas filling will become ionized. Although the reactance of second secondary winding 13 will then limit the lamp current in ballast fashion, the inverter circuit will continue to apply across the electrode gap of the lamp high peak voltages which become unnecessary once ionization occurs. The preheater will, moreover, remain energized longer than necessary to facilitate ionization, and biasing current will flow through resistor 15 for starting each cycle as long as main supply switch 17 is closed. All of this adversely affects the overall efficiency of operation as gauged by the electrical power input required for a given level of light power output. These drawbacks are eliminated by certain features of the invention embodied in the circuitry depicted in FIG. 2; and certain additional features of the invention also embodied in such circuitry account for still further improvements in overall efficiency.
Referring to FIG. 2, wherein like reference numerals are employed to identify like parts shown in FIG. 1, it is seen that second secondary winding 13 is now electrically connected in series voltage-aiding relationship with first secondary winding 11 so that current driven in one direction through load 5 is also driven through the base of transistor 1. Because of this feature, the base drive to transistor 1 is self-regulating, i.e. increases in load current cause corresponding increases in the base drive current, whereas decreases in load current cause corresponding decreases in base drive current.
In FIG. 2, load 5 is schematically depicted as a conventional fluorescent lamp of the type having resistive preheater filaments at opposite ends which serve also as electrodes 27, 29 between which arcing in the gas filling is to be initiated to ionize the gas filling. Only one of the electrodes, however, need be used in its dual capacity and, to this end, electrode 27 is connected in a series circuit including battery 3, main supply switch 17 and the emitter-collector path of a starting bipolar transistor 31. Current from battery 3 will heat electrode 27 when main supply switch 17 is closed and starting transistor 31 is in a conductive state. On the other hand, the resistive filament of opposite electrode 29 is shunted and, as such, is connected by a conductor 33 to one side of a capacitor 35, the other side of which is connected by a conductor 37 through second secondary winding 13, first second secondary winding 11, the base-emitter path of transistor 1 (or diode 25, depending on the direction of the load current) and a conductor 39 to a terminal 40 of electrode 27 on the negative side of battery 3.
As an efficiency-promoting feature, starting transistor 31 is part of a sub-circuit for driving current through the resistive filament of electrode 27 only for a time period of limited duration starting with the closing of main supply switch 17 and ending about 2 seconds later when full ionization is certain to have occurred in the lamp. To this end, starting transistor 31 has its base-emitter path connected in series with a resistor 41 and capacitor 43, the serially connected base-emitter path, resistor 41 and capacitor 43 being connected by a conductor 45 to input terminal 19 at the positive side of battery 3 and by conductor 39 and a conductor 47 to input terminal 21 at the negative side of battery 3. The closing of main supply switch 17 thereby causes forward biasing current to flow via resistor 41 and capacitor 43 through the base-emitter path of starting transistor 31 to switch the starting transistor ON and maintain its ON state until capacitor 43 becomes fully charged at the end of the aforementioned time period of limited duration.
The sub-circuit of which starting transistor 31 is a part provides another efficiency-promoting feature whereby, over the same time period during which it energizes the resistive heating filament of lamp electrode 27, it supplies turn-on current to the power transistor 1, the latter transistor conveniently being viewable as part of another sub-circuit specifically provided to drive current through load 5 across the gap between electrodes 27, 29. To this end, when starting transistor (31) is conductive, current flows from input terminal 19 via conductor 45 through the emitter-collector path of starting transistor 31, thence via a conductor 49 through resistor 15, the base-emitter path of power transistor 1 and conductor 47 to input terminal 21. Conductor 49 branches off from the emitter-collector path of starting transistor 31 where a connection 51 is made from such path to the other terminal 53 of the resistive heating filament of electrode 27. Current flowing through resistor 15 supplies the base-emitter path of transistor 1 with a forward bias current which constitutes the turn-on current for starting the operation of power transistor 1 and the sub-circuit of which power transistor 1 forms part. Efficiency is promoted by the limited duration of the forward bias current flowing through resistor 15, since such forward bias current is only needed until ionization in the lamp has taken place, whereafter capacitor 35 is capable of supplying the forward bias current required for power transistor 1 during the portion of each cycle where power transistor 1 is required to turn ON. Thus, the current drain placed by resistor 15 on battery 3 in the prior art circuitry of FIG. 1 is eliminated in the circuitry of FIG. 2 about 2 seconds after main supply switch 17 is closed.
It will be appreciated that power transistor 1 repeatedly undergoes successive first and second half-cycles of conductivity, which conductivity rises from 0 in the first-half cycle to provide a rising and falling current from battery 3 through primary winding 7 to induce rising and falling voltages in first and second secondary windings 11, 13 and which, in the second half-cycle, remains at 0 to cause the falling voltages last induced in the secondary windings to reverse in polarity, whereby during each first half-cycle of power transistor conductivity, the secondary winding voltages drive current in one direction through lamp load 5 and during each second half-cycle of power transistor conductivity, the secondary winding voltages drive current in the opposite direction through lamp load 5. Resistor 23 permits a small amount of base drive current to flow in power transistor 1 to keep the sub-circuit of power transistor 1 oscillating while ionization is occuring in lamp-load 5. Capacitor 35 stores energy during the first half-cycle of power transistor conductivity for augmenting the energy stored by the magnetic field of the transformer during the first half-cycle in energizing lamp-load 5 during the second half-cycle of power transistor conductivity.
A parallel resistance-capacitance network 55, 57 is connected across conductors 39, 45, hence across the serially-connected collector-emmitter path of power transistor 1 and primary winding 7 so as to establish a reverse bias on the collector of power transistor 1 immediately upon the closing of main supply switch 17 to connect imput terminals 19, 21 across battery 3.
Core 9, upon which primary winding 7 and secondary windings 11, 13 are wound, is preferably a ferrite slug, and an air gap is formed in the closed magnetic path which causes the transformer to exhibit a gradual saturation of flux density as the magnetic intensity increases.
The period of oscillation of the current driven through lamp-load 5 is shorter than the average recombination period of the positive and negative ions of the ionized gas filling of the load.
The circuit shown in FIG. 2 oscillates at approximately 62 KHZ after full ionization is achieved, the frequency of oscillation being slightly higher prior to full ionization. Particulars of the circuit elements shown in FIG. 2 are as follows:
Resistor 15--270 ohms, 1/4 w
Resistor 23--33 ohms, 1/4 w
Resistor 41--10.0 Kohms, 1/4 w
Resistor 55--3.3 Kohms, 1/4 w
Primary winding 7--20 turns, 24 gauge
First secondary winding 11--4 turns, 30 gauge
Second secondary winding 13--350 turns, 30 gauge
Capacitors 43, 57--220 mfd, 16 v
Capacitor 35--0.0022 mfd, 600 v
Power transistor 1--TIP 33C (NPN)
Starting transistor 31--TIP 125 (PNP Darlington)
Transformer core 9--1/4" square×1" long ferrite slug
Battery 3--12 v
Conductor 47 includes a diode 59 having its cathode adjacent terminal 21 in order to protect the circuitry from an inadvertent application of a reverse polarity voltage at terminals 19, 21.
It is interesting to note what takes place when the voltage at terminals 19, 21 is reduced, as in the case of a slowly discharging battery 3. As the battery voltage decreases, the circuitry continues to operate satisfactorily until such time as the peak-to-peak voltage across lamp-load 5 is too low to sustain full ionization. At this point, the load impedance increases abruptly. The increased load impedance reduces the peak-to-peak voltage that develops across capacitor 35 during each half-cycle. The decrease in voltage across capacitor 35 will prevent capacitor 35 from providing sufficient base drive to power transistor 1 to initiate a new cycle of operation. Thus, power transistor 1 will remain in its OFF state and the only drain on battery 3 will be the small amount of current flowing through resistor 55, i.e. about 5 ma. The current flow through resistor 55 will drain away any residual charge that remains on capacitor 57 and, through a diode 61 connected between conductor 45 and the common terminal of resistor 41 and capacitor 43, will also drain away any residual charge that remains on capacitor 43. It is desirable to drain away any residual charges on capacitors 43, 57 so that the circuitry will be ready for another start cycle when terminals 19, 20 are applied across a fresh battery.
The large air gap in the closed magnetic path of the transformer, which air gap stems from the use of a ferrite slug as the common core for primary winding 7, first secondary winding 11 and second secondary winding 13, promotes overall efficiency since the magnetizing current does not increase sharply just prior to power transistor 1 turning OFF, as would be the case with square loop type transformer cores.
During the starting operation, while the impedance of lamp-load 5 is high due to initial non-ionization, the load current is relatively small, i.e. less than 50 ma peak, both when power transistor 1 is ON and OFF. However, when power transistor 1 is OFF, the negative current through secondary windings 11, 13 will drive the voltage across lamp-load 5 to approximately -400 v, and the peak-to-peak voltage across capacitor 35 will be relatively small mainly due to the limiting effect of the initial high impedance of lamp-load 5 on the current that can flow into capacitor 35 during each half-cycle. After a fraction of a second, ionization takes place due mainly to the -400 v peaks across lamp-load 5 in conjunction with the thermionic emission of filament electrode 27. The lower impedance associated with ionization causes the load current to increase to about 230 ma peak which causes capacitor 35 to acquire a higher voltage during each half-cycle. The peak voltage across lamp-load 5 when power transistor 1 turns OFF each half-cycle then drops considerably. Thus, during starting, a high peak voltage is applied across lamp-load 5 and filament electrode 27 is heated. The high peak voltage impressed across lamp-load 5 during the starting process automatically adjusts to a lower (more efficient) voltage after ionization takes place, and the heating current goes to zero about 2 seconds after the input voltage is first applied. The load current flows through the base of power transistor 1 and automatically adjusts the base drive current to compensate for changes in load current. The starting current through resistor 15 for power transistor 1 is automatically adjusted to zero about 2 seconds after the input voltage is first applied.
The possible applications of the fluorescent lamp circuitry according to the invention are many. For example, it can be used to provide illumination aboard boats, particularly sailboats, or to provide illumination in motorized campers when no external power hook-up is available, or to provide emergency household illumination during blackouts. However, an especially useful application of the fluorescent lamp circuitry is for night-fishing to attract fish by the illumination it provides. In this respect, it would be used in combination with a watertight housing. Such a combination will now be described with reference to FIG. 3 of the drawings.
In FIG. 3, a hollow tubular body 63 of light-transmissive rigid material, such as cellulose acetate butyrate (C.A.B.) or polycarbonate, is provided in which fluorescent lamp 5 of FIG. 2 is centrally disposed with clearance thereabout. The length of tubular body 63 exceeds the length of lamp 5 so that opposite end portions 65, 67 of the body are left unoccupied by the lamp. One such end portion 65 contains the circuitry of FIG. 2 in a protective encapsulation 69, suitably of epoxy material, from which electrical output leads 33, 39, 49 of the circuitry emerge and connect to the appropriate terminal pins of the lamp.
Similar cup-like end caps 71, 73 of elastomeric material, such as rubber, are removably capped over end portions 65, 67 respectively, each with a watertight interference fit. The outer peripheries of end caps 71, 73 taper inwardly towards the center of the assembly. End cap 65 is provided with a passage 75 extending through its base from its cup chamber to the surrounding atmosphere. An elongated two-conductor cable 77 has one end thereof connected within end cap 71 to electrical input terminals 19, 21 emerging from encapsulation 69. Cable 77 passes out of end cap 71 via passage 75 and has an elastomeric insulating jacket of a cross-sectional shape which complements that of passage 75 and makes a watertight interference fit therewith. The other end of cable 77 is connected to battery 3, switch 17 being omitted for simplification. Within the cup chamber of end cap 73, a suitable support 79, into which the lamp terminal pins are plugged, is provided for the corresponding end of lamp 5. | 4y
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BACKGROUND OF THE INVENTION
Much of the research and development effort in the field of automotive finishes is currently directed to the development of color coat/clear coat automotive finishes. It has been found that an excellent appearance, with depth of color and with metallic glamour, can be obtained by applying a transparent coat over a pigmented coat. Unfortunately, the durability of these transparent clear coats has left much to be desired. Often, checking, cracking and flaking occur after relatively short periods of exposure to weathering, necessitating costly refinishing.
An iminated acrylic lacquer coating composition exhibiting excellent durability is disclosed by Meyer, U.S. Pat. No. 4,168,249, issued Sept. 18, 1979. In addition to durability, this unique lacquer also exhibits the ability to adhere to either lacquer or enamel finishes. This latter property makes the Meyer lacquers attractive for across-the-board use in refinish shops as well as for original equipment finishes. When utilized without pigmentation, however, this and other iminated lacquers display a tendency to yellow over a period of time, rendering them unsuitable for color coat/clear coat finishes.
The novel composition of this invention displays all the advantages of the Meyer composition, viz., durability and lacquer/enamel adhesion, without the concomitant disadvantage of excessive yellowing.
SUMMARY OF THE INVENTION
This clear acrylic lacquer coating composition consists essentially of 5-40% by weight of a film-forming binder and 60-95% by weight of volatile organic solvents; wherein the binder consists essentially of:
(a) about 0-65% by weight, based on the weight of the binder, of one or more polymers selected from the group consisting of poly(methyl methacrylate) and other copolymers of methyl methacrylate having a relative viscosity of about 1.17 to 1.20 measured at 25° C. on a 0.5% polymer solids solution using dichloroethylene solvent;
(b) about 0-25% by weight, based on the weight of the binder, of cellulose acetate butyrate having a viscosity of about 1-20 seconds and a butyryl content of 20-55% by weight;
(c) about 10-40% by weight, based on the weight of the binder, of a polyester plasticizer comprising the reaction product of a polyol and an organic dicarboxylic acid or an anhydride of an organic dicarboxylic acid having an acid number of 0.1-10;
(d) about 0-10% by weight, based on the weight of the binder, of a phthalate plasticizer; and
(e) about 15-80% by weight, based on the weight of the binder, of a terpolymer of units of methyl methacrylate, ethyl acrylate, and t-butylaminoethyl methacrylate;
wherein (a), (b), (c), (d) and (e) total 100%.
DESCRIPTION OF THE INVENTION
The clear acrylic lacquer coating composition of the present invention, particularly suitable for use as the clear coat of a color coat/clear coat automotive finish, provides coatings possessing a combination of resistance to outdoor weathering, smoothness, a high level of gloss, and vastly diminished "in-the-can" yellowing.
The coating composition has a binder content of film-forming constituents of about 5-40% by weight. The remaining 60-95% of the composition is a solvent blend for the binder.
The acrylic polymers utilized in the coating composition are prepared by solution polymerization, wherein the monomers are blended with solvent and polymerization catalyst and are heated to about 75°-150° C. for 2-6 hours to form polymers having relative viscosities of about 1.17-1.20, measured at 0.5% polymer solids at 25° C. with dichloroethylene solvent.
Typical solvents used to prepare the acrylic polymers include toluene, ethyl acetate, acetone, ethylene glycol monoethylether acetate, methylethyl ketone, isopropyl alcohol, and other aliphatic, cycloaliphatic and aromatic hydrocarbons conventionally used for this purpose.
About 0.1-4% by weight, based on the weight of the monomers, of polymerization catalyst is used in the preparation of the acrylic polymers. Typical catalysts include azobisisobutyronitrile, azobis-α,γ-dimethyl-valeronitrile, benzoyl peroxide and t-butylpivalate.
A chain transfer agent can be used to control the molecular weight of the acrylic polymers. Typical chain transfer agents include α-mercaptoethanol, dodecylmercaptan, benzene thioethanol, mercaptosuccinic acid, butylmercaptan and mercaptopropionic acid.
The coating composition contains about 0-65% and preferably about 40-80% by weight, based on the weight of the binder, of poly(methyl methacrylate) and/or other copolymers of methyl methacrylate. A preferred composition also contains about 15-80% by weight and preferably about 2-20% by weight, based on the weight of the binder, of a terpolymer of units of methyl methacrylate, ethyl acrylate, and t-butylaminoethyl methacrylate. Ordinarily, the terpolymer will consist of about 20-90% by weight of units of methyl methacrylate, 2-40% by weight of units of ethyl acrylate, and 2-60% by weight of units of t-butylaminoethyl methacrylate. Excellent coating compositions can also be obtained, however, with significantly greater amounts of t-butylaminoethyl methacrylate. Poly(t-butylaminoethyl methacrylate) may be used in place of the methyl methacrylate/ethyl acrylate/t-butylaminoethyl methacrylate terpolymer. A preferred terpolymer consists essentially of about 60-90% by weight of units of methyl methacrylate, 10-20% by weight of units of ethyl acrylate, and 2-20% by weight of units of t-butylaminoethyl methacrylate.
Up to about 25%, preferably 5-25% by weight, based on the weight of the binder, of cellulose acetate butyrate is used in the coating composition. The cellulose acetate butyrate has a butyryl content of about 30-55% by weight and a viscosity of about 1-20 seconds, measured according to ASTM D-1343-56. Preferably, low viscosity cellulose acetate butyrate having a butyryl content of about 35-40% by weight and a viscosity of 1-3 seconds is used.
The composition contains about 10-40% by weight, based on the weight of the binder, of a polyester plasticizer containing the reaction product of a polyol, an organic dicarboxylic acid or an anhydride thereof having an acid number of about 0.1-10, and, optionally, a saturated fatty oil or fatty acid. The plasticizer is prepared by conventional polymerization techniques, wherein the constituents and a conventional esterification catalyst such as lead tallate, sodium naphthenate, barium oxide, barium hydroxide, or lithium hydroxide are reacted at 80°-200° C. for about 0.5-6 hours. Typical polyols that can be used to prepare the polyester include ethylene glycol, propylene glycol, dipropylene glycol, butane diol, diethylene glycol and neopentyl glycol. Other polyols that can be used are glycerol, trimethylol propane, trimethylol ethane, pentaerythritol, dipentaerythritol, and sorbitol. Typical organic dicarboxylic acids or anhydrides that can be used to prepare the polyester include adipic acid, azelaic acid, chlorendic acid, chlorendic anhydride, phthalic acid, phthalic anhydride, terephthalic acid, isophthalic acid, succinic acid, succinic anhydride, trimelletic acid, and trimelletic anhydride. A typical saturated fatty oil that can be used to prepare the polyester is coconut oil. Polyesters of a polyol and an organic dicarboxylic acid or anhydride thereof can additionally be reacted with a monocarboxylic acid rather than a fatty oil or acid. A preferred plasticizer contains neopentyl glycol, adipic acid, and benzoic acid.
It is recommended that the coating composition be fortified with at least one ultraviolet light stabilizer or ultraviolet screener to prevent degradation of the resultant finish by ultraviolet light. Highly preferred for this purpose is a combination of an ultraviolet screener and a hindered amine light stabilizer. The coating composition will contain about 0-6% by weight, based on the weight of the binder, of this combination, preferably about 0.5-3% by weight of a hindered amine light stabilizer and about 0.5-3% by weight of an ultraviolet screener. Preferred ultraviolet screeners include 2-(o-hydroxyphenyl)benzotriazoles, nickel chelates, o-hydroxybenzophenones, and phenyl salicylates. Highly preferred are the 2-(o-hydroxyphenyl)benzotriazoles.
While the coating composition will ordinarily be nonpigmented, it is acceptable, for clear coat use, to incorporate transparent particles, i.e., pigments having a refractive index the same as or similar to the refractive index of the film-forming constituents, in a pigment-to-binder weight ratio of about 1/100 to 150/100. Conventional pigments, e.g., inorganic pigments, metallic powders and flakes, organic dyes, organic pigments, and lakes, may also be added, in these same weight ratios, if the coating composition is to be employed other than as the clear coat of a clear coat/color coat finish.
The composition may, of course, contain additional additives, e.g., silicones, that are typically incorporated into acrylic lacquer coating compositions.
The coating composition can be applied over a variety of substrates, e.g., metal, primed metal, metal coated with enamels or lacquers, wood, glass, plastics, and the like, by spraying, electrostatic spraying, dipping, brushing, flow-coating, or any other conventional application method. Ordinarily, it will be sprayed onto a color-coated automotive substrate to form a color coat/clear coat finish.
The applied coating can be dried at ambient temperatures or, alternatively, can be baked at relatively low temperatures, e.g., 35°-100° C., for about 15 minutes-2 hours.
The resulting finish has an excellent appearance and can be rubbed or polished with conventional techniques to improve its smoothness or gloss or both. The finish is hard and resistant to weathering, staining, and scratching. It adheres well to all of the aforementioned substrates.
The present invention will be more readily understood from the following illustrative example, wherein all quantities, percentages, and ratios are on a weight basis unless otherwise indicated.
EXAMPLE
I. Preparation of methyl methacrylate/ethyl acrylate/t-butylaminoethyl methacrylate polymer solution
______________________________________ Parts______________________________________Portion 1Methyl methacrylate monomer,hydroquinone - inhigited(55 p.p.m.) 169.13Ethyl acrylate monomer 47.87t-Butylaminoethyl methacrylatemonomer, hydroquinone -inhigited (850-1350 p.p.m.) 15.97Ethyl acetate 105.69Butyl acetate 82.76Portion 22,2'-Azobisisobutyronitrile 0.45Ethyl acetate 5.98Portion 3Methyl methacrylate monomer,inhibited as above 79.78t-Butylaminoethyl methacrylate,inhibited as above 6.38Toluene 3.97Portion 42,2'-Azobisisobutyronitrile 0.80Ethyl acetate 7.98Toluene 8.00Portion 52,2'-Azobisisobutyronitrile 0.90Ethyl acetate 11.97Toluene 12.00Portion 6Isopropyl alcohol 59.84Toluene 79.78Acetone 99.73Total 798.98______________________________________
Portion 1 is charged into a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, and a heating mantle, and is heated to reflux, about 94° C. The heat is then removed. Portion 2 is quickly added to the vessel, and the resulting reaction mixture is held for about 10 minutes. Next, Portions 3 and 4 are added simultaneously over a period of 60 minutes, and the reaction mixture is again held for 10 minutes. Portion 5 is then added over a period of 90 minutes; heat is supplied as needed to maintain reflux or a minimum temperature of 90° C. over a 15 minute holding period. At the end of this period, the heat is removed and Portion 6 is added to dilute the reaction mixture; 10 minutes of mixing follows.
The resulting polymer solution has a solids content of about 38.5-40.5 and a relative viscosity of about 1.17-1.20, measured at 25° C. on a 0.5% polymer solids solution using dichloroethylene solvent. The polymer contains about 78% methyl methacrylate, 15% ethyl acrylate, and 7% t-butylaminoethyl methacrylate.
II. Preparation of neopentyl glycol/adipic acid/benzoic acid polyester plasticizer
______________________________________ Parts______________________________________Portion 1Neopentyl glycol solution(90% in water) 406.00Portion 2Adipic acid 385.00Benzoic acid 203.70Dibutyltin oxide 0.30Portion 3Toluene 43.64Portion 4Toluene 48.49Total 1087.13______________________________________
An inert gas blanket should be maintained throughout the following procedure in order to prevent darkening of color. Portion 1 is charged into a reaction vessel and heated to about 65° C. This temperature is maintained while Portion 2 is added. Next, Portion 3 is added and the reaction mixture is heated to its reflux temperature of about 138° C. The temperature of the mixture is then increased to about 160° C. and held there for one hour. A series of temperature increases and holding periods follows: the mixture is heated to about 182° C. and held at that temperature for 15 minutes, heated to about 204° C. and held for 15 minutes, heated to about 227° C. and held for 15 minutes, and finally heated to a cooking temperature of about 240° C. After one hour at 240° C., the acid number and viscosity of the reaction mixture are checked. Cooking should continue until an acid number of less than 10 is reached. Portion 4 is then added as needed to achieve a Gardner Holdt viscosity of about U-W, and the resulting polyester resin solution is cooled to room temperature.
III. Preparation of methyl methacrylate polymer solution
______________________________________ Parts______________________________________Portion 1Methyl methacrylate monomer 322.28Acetone 112.71Toluene 48.33Benzoyl peroxide 2.18Portion 2Acetone 32.29Toluene 290.29Total 808.08______________________________________
Portion 1 is premixed, charged into a reaction vessel, heated to about 100° C., and held at this temperature for about 11/2 hours. Portion 2 is then added, and the resulting polymer solution is cooled to room temperature.
The polymer solution has a polymer solids content of about 40% and a relative viscosity of about 1.19 measured at 25° C. on a 0.5% polyer solids solution using dichloroethylene solvent.
IV. Preparation of the clear lacquer coating composition
______________________________________ Parts______________________________________Portion 1Ethylene glycol monoethylether acetate 62.09Toluene 82.35Butyl benzyl phthalate 7.79Methyl methacrylate/ethylacrylate/t-butylaminoethylacrylate polymer solution(prepared in step I.) 285.20Cellulose acetate butyratesolution (25% cellulose acetatebutyrate having a butyryl con-tent of about 30-55% and a1-second viscosity in a solventof 3 parts ethylene glycol mono-ethyl ether acetate/46 partsacetone) 155.63Tinuvin 144® hindered amine basedultraviolet light stabilizer andantioxidant (available fromCiba-Geigy Corporation) 2.60Tinuvin 328® substituted benzotria-zole (available from Ciba-GeigyCorporation) 2.60Silicone solution (1% solidssilicone in xylene) 0.25Neopentyl glycol/adipic acid/benzoic acid polyester plasticizer(prepared in step II.) 43.35Methyl methacrylate polymer solu-tion (prepared in step III.) 136.14Total 778.00______________________________________
The above constituents are added in the order shown and mixed for 1 hour, or until uniformity is obtained. The clear lacquer composition is reduced with acetone to a package viscosity of about 400-420 centipoise.
The lacquer is further reduced with a thinner of acetone/toluene/xylene in a ratio of 22.5/43.5/34, to a spray viscosity of about 32 seconds, measured at 25° C. with a No. 1 Fisher Cup.
The lacquer is sprayed onto the intended substrate, which oridinarily will be a primed and color-coated automotive panel, and is allowed to dry at room temperature for 24 hours.
The resulting color coat/clear coat finish exhibits good adhesion and commercially acceptable clarity, as demonstrated by the following tests.
A. Adhesion
Three sets of panels are prepared by applying three different clear lacquers over a weathered nonaqueous dispersion OEM enamel finish. The first lacquer is that of the present invention, containing t-butylaminoethyl methacrylate (t-BAEMA). The second lacquer is prepared according to the teachings of Meyer, U.S. Pat. No. 4,168,249. The third is a non-iminated lacquer prepared as in Meyer but containing no alkylene imine.
The adhesion of the clear lacquer topcoat to the pigmented basecoat is determined on these three sets of panels by scribing a rectangular grid through the topcoat to the metal with a knife, placing Scotch® brand 610 cellophane tape of one-inch width over the grid, and then removing the tape.
A subjective rating of 10 indicates that none of the topcoat is removed by the tape, while a rating of 0 indicates that all of the topcoat is removed. The average rating for each topcoat is listed in the following table:
______________________________________No. Type of Lacquer Adhesion Rating______________________________________1 t-BAEMA 82 Meyer iminated 83 non-iminated 3______________________________________
The above results show that the lacquer of the present invention adheres as well as the Meyer iminated acrylic lacquer to a standard enamel finish. Although it is the primary amine in the Meyer lacquers that is responsible for the unacceptable yellowing, these results show that removal of the alkylene imine is not a viable solution since it also serves as an adhesion promoter.
B. Clarity
A clear Meyer lacquer formulated with an iminated acrylic resin containing a primary amine changes from a Gardner Holdt color of 1 to a Gardner Holdt color of 6, per ASTM D-1545-63, upon three months' shelf storage. The clear lacquer of the present invention, formulated with t-butylaminoethyl methacrylate, a secondary amine, changes color from 1 to 3 in a side-by-side test with the Meyer lacquer. This latter color change is commercially acceptable; the former is not. | 4y
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BACKGROUND OF THE INVENTION
1. Technical Field
This invention relates to a three-phase induction motor control method for performing motor drive control and regenerative control based on digital values.
2. Description of the Related Art
Recent control of three-phase induction motors is in many cases performed by a vector control method of controlling the instantaneous value of motor stator current and generating a torque equivalent to that of a shunt DC machine.
Using vector control of this type to perform motor drive control and regenerative control of a three-phase induction motor is disclosed in e.g. Japanese patent application Laid-Open No. 59-14385.
If an induction motor is subjected to vector control in cases where velocity control is performed up to a region of high rotational velocity, as in a spindle motor of a machine tool or the like, or in cases where control is performed to weaken excitation in accordance with a torque command at a constant rpm, the torque command, excitation current, secondary current and slip frequency become non-linear due to such effects as the secondary leakage impedance and core loss of the motor. As a result, the output torque also becomes non-linear with respect to the torque command, so that a linear relationship between the torque command and output torque cannot be accurately maintained.
Furthermore, since the output of an induction motor generally varies in proportion to the square of the voltage impressed upon the motor, the output will fluctuate when the AC input voltage undergoes a large variation. In the vector control method, a measure devised for preventing such a fluctuation in output entails varying the amount of maximum slip in dependence upon the AC input voltage. Nevertheless, satisfactory results are not obtained in terms of holding the output of the induction motor constant.
At time of regenerative braking, moreover, the power-factor fluctuates due to the capacity of a phase advancing capacitor on the input side, and there is an increase in power supply distortion and reactive power.
SUMMARY OF THE INVENTION
The present invention has been devised to solve the foregoing problems and its object is to provide a three-phase induction motor control method in motor drive control and regenerative control based on the vector control method using a power amplifier comprising a converter and an inverter, in which a linear output torque can be obtained with respect to a torque command without using a flux sensor, and in which the output of the three-phase induction motor can be held constant even when there are fluctuations in power supply voltage.
According to the present invention, there is provided a three-phase induction motor control method based on vector control for converting an AC input into a direct current at the time of motor drive control to drive a three-phase induction motor at a variable velocity. The three-phase induction motor is driven by the output of a first inverter to which the converted direct current is applied. In control method an output current of the three-phase induction motor is converted into a direct current at the time of regenerative control to regenerate the output of a second inverter, to which the direct current resulting from the conversion is applied, in an AC power supply. The method includes vector analyzing an excitation current command and secondary current command into an excitation flux direction component and a motor electromotive force direction component, respectively, on the basis of a torque command with respect to the three-phase induction motor and an excitation flux command decided to accommodate the three-phase induction motor. The method also includes determining a primary current command of the motor based on a synthesis of the vector components, and detecting the voltage of a direct current link portion of a circuit for converting the AC input into a direct current. The method further includes correcting the excitation flux command in dependence upon the detected voltage, obtaining a linear torque command and performing constant output control irrespective of a fluctuation in the power supply voltage, and adjusting a phase between voltage and current on the side of the AC power supply at the time of regenerative control, thereby performing control in such a manner that reactive power is reduced.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an embodiment of a system for practicing the method of the present invention;
FIG. 2 is a circuit diagram of a portion of FIG. 1;
FIG. 3 is an equivalent circuit of one phase of a three-phase induction motor;
FIG. 4 is a vector diagram and
FIGS. 5-10 are graphs for describing the characteristics of a three-phase induction motor.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The method of the invention will be described in conjunction with the drawings. FIG. 1 is a block diagram of a control circuit for practicing the method of the invention, and FIG. 2 is a circuit diagram of a power amplifier section shown in FIG. 1.
Before describing the control circuit of FIG. 1, let us refer to FIGS. 3 through 7 to describe the technique on which the present invention is premised.
FIG. 3 is an equivalent circuit of one phase of a three-phase induction motor, FIG. 4 is a vector diagram, and FIGS. 5, 6 and 7 are graphs for explaining characteristics. Vector control of a three-phase induction motor is performed as follows:
(1) A velocity command ω c is set.
(2) Motor velocity ω m is sensed.
(3) A torque command T c is obtained by performing a subtraction between ω c and ω m .
(4) An estimated value ω' s of slip is obtained as follows:
ω'.sub.s =K.sub.0 ×T.sub.c ×ω.sub.m (K.sub.0 is a constant)
(5) An estimated value ω' 0 of excitation frequency is obtained as follows:
ω'.sub.0 =ω.sub.m +ω'.sub.s
(6) A flux Φ corresponding to the excitation frequency ω' 0 is obtained from the characteristic diagram of FIG. 5.
(7) A winding resistance measurement, a no-load test and a lock test are carried out, and values of primary induction voltage E 1 and core loss current I 0i of the excitation current I 0 are found from the equivalent circuit of FIG. 3, and values of magnetization current I 0M , excitation resistance R 0 and excitation reactance L 0 are found from the vector diagram of FIG. 4.
(8) A revolving coordinate system is transformed into a fixed coordinate system, with the flux Φ of the revolving field serving as a reference phase. This is done as follows:
○1 Excitation current I 0 is obtained as follows by taking the vector sum between a component I 0M along the Φ axis and a component I 0i along the E 1 axis:
I.sub.0 =I.sub.0M +I.sub.0i
○2 Similarly, secondary current I 2 is obtained as follows by taking the vector sum between a component I 2M along the Φ axis and a component I 2 ω along the E 1 axis:
I.sub.2 =I.sub.2M +I.sub.2W
○3 The flux Φ is obtained as
Φ=L.sub.0.I.sub.0M
from
E.sub.1 =dΦ/dt
=L.sub.0 ×(dI.sub.0M /dt)
=d(L.sub.0.L.sub.0M)/dt
Next,
Φ.sub.0M =Φ/L.sub.0
I0i=Kω'.sub.0 Φ (K is a constant)
are obtained from the characteristic diagram of FIG. 6.
(9) The E 1 -axis component I 2w of secondary current I 2 is obtained from
I.sub.2w =(T.sub.c /Φ)
(10) The slip frequency ω s is determined from the characteristic diagram of FIG. 7.
(11) The Φ-axis component I 2M of the secondary current I 2 is obtained from
I.sub.2M =I.sub.2w ×ω.sub.s ×(L.sub.2 /R.sub.2)
(12) The component of primary current I 1 in the Φ direction is obtained from
I.sub.1 (Φ)=I.sub.0M +I.sub.2
(13) The component of primary current I 1 in the E 1 direction is obtained from
I.sub.1 (E.sub.1)=I.sub.0i +I.sub.2w
The primary current so obtained is a current command for a case where all constants of the induction motor are taken into consideration, and is for the purpose of obtaining a linear output torque with respect to a torque command.
(14) The excitation frequency ω 0 is obtained from
ω.sub.0 =ω.sub.m +ω.sub.s
Let us return to the block diagram of FIG. 1 to describe the same. As shown in FIG. 2, a power amplifier a, which comprises a converter b and an inverter c respectively provided on AC input and DC output sides, is connected to an AC power supply. The converter b is constituted by a full-wave rectifier bridge composed of diodes, each of which is connected in parallel with a transistor inverter. A DC voltage is obtained by the converter b of the power amplifier a and is applied to the inverter c. The output voltage of the inverter c is pulse-width controlled by a PWM/current control circuit m before being impressed upon a three-phase induction motor d.
The velocity command ω c and the motor velocity ω m , which is obtained, via a F/V converter o, from a voltage signal detected by a tachogenerator e, are inputted to a comparator p to obtain the torque command T c as a difference signal voltage. The torque command T c is corrected via a PI and a clamping circuit g to form an actual torque command T m . Thereafter, the primary current I 1 and excitation frequency ω 0 are obtained as described above in (4)-(14). These are applied to a 2-to-3 phase converter circuit l. The 2-to-3 phase converter circuit l converts orthogonal two-phase currents into three-phase currents to form current commands Iu, Iv, Iw in the respective three phases, these commands being applied to the PWM/current control circuit m. The input currents to the motor are fed back to the circuit m by CT1, CT2 to be compared with the output currents of the 2-to-3 phase converter circuit, whereby the circuit delivers a commanded current I in each phase to the inverter c.
The operation of the invention will now be described in terms of detecting voltage Vdc on the DC side of the power amplifier and correcting the flux Φ and induced voltage V. If a triangular wave is formed within the PWM circuit, then the output voltage will differ depending upon the degree to which the triangular wave is utilized, considering the relationship between a voltage command amplitude and the actual terminal voltage of the motor. Let B represent the amplitude of the triangular wave, and let A represent the amplitude of the PWM signal, as shown in FIG. 8(a). If the amplitude ratio A/B is less than 1, then the output voltage V u from a point u in FIG. 9 is as follows:
V.sub.u =(T.sub.ON1 /T)×√2V.sub.ac {(1+sin θ)/2}
where T represents the period. The line voltage across u-v applied to the motor is ##EQU1## where
Vac: effective value
Vdc: set value (DC voltage)
Next, let us consider control by a base signal of the transistor constituting the inverter for a case where the amplitude ratio A/B is greater than 1. Though a method exists in which the base signal of Tr in the inverter is turned off whenever the amplitude ratio (A/B) exceeds 1, as shown in FIG. 8(b), this method involves certain problems, namely the fact that the output voltage will not rise, switching loss is great, etc. FIG. 10 illustrates the manner in which the line voltage V u-v varies with respect to the amplitude ratio A/B.
In the present invention, all of the transistors Tr turn on, as shown in FIGS. 8(c), (d), in a range where the amplitude A of the PWM signal exceeds the amplitude B of the triangular wave. In other words, when the DC voltage is low, the flux command Φ above a base velocity is increased, the amplitude of the PWM circuit with respect to the triangular wave is raised, and the terminal voltage of the motor is raised to obtain a constant output. When the DC current is high, the flux command is decreased from a region below the base velocity, the amplitude of the PWM command signal with respect to the triangular wave is reduced, and the terminal voltage of the motor is lowered to obtain a constant output. As shown in the block diagram of FIG. 1, such control is performed by inputting the DC voltage V dc sensed by the inverter to a data map i indicating the relationship between excitation frequency and flux, and correcting the flux Φ in dependence upon the DC voltage V dc .
It should be noted that an induced voltage compensating circuit n corrects the value of induced voltage with respect to the motor velocity signal ω m and applies the corrected value to the PWM/current control circuit m.
The regenerative control operation of the present invention will now be described with reference to FIG. 2. A regenerative control circuit P is provided with a voltage control circuit r and a power-factor adjusting circuit q.
When regenerative control is performed, voltage on the DC side of the power amplifier a and the DC voltage command value are compared. When the voltage of the DC side is larger, an offset signal is inputted to the power-factor adjusting circuit q through the voltage control circuit r. The input voltage on the AC side of the power amplifier a is applied to the power-factor adjusting circuit via the PT, and the regenerative current command signal is outputted to the current control circuit in such a manner that the currents on the AC input side of the power amplifier sensed by CT3, CT4 take on the same phase as the voltage on the AC side, i.e. in such a manner that the power-factor becomes 1. The PWM circuit controls the transistor inverter on the basis of this commanded value.
Industrial Applicability
Thus, in motor drive control and regenerative control based on the vector control method using a power amplifier comprising a converter and an inverter, the three-phase induction motor control method of the present invention enables a linear output torque to be obtained with respect to a torque command without using a flux sensor, and enables the output of the three-phase induction motor to be held constant even when there are fluctuations in power supply voltage. | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
This patent application is a continuation of U.S. Ser. No. 07/434,760, filed Nov. 9, 1989, now abandoned.
FIELD OF THE INVENTION
This invention relates to novel polyorganosiloxanes having pendant thereon aliphatic isocyanate groups and a process for their production.
DESCRIPTION OF THE PRIOR ART
Silicone-based materials are widely employed today as specialty coatings, elastomers, films, membranes, adhesives and coupling agents. Silicone-based materials, such as polysiloxanes offer unique properties such as high oxygen permeability, lubricity and low surface tension compared to conventional carbonaceous materials. There is therefore a continuous interest in finding effective ways to combine the advantageous properties of silicone-based materials in applications where heretofore carbonaceous materials were employed.
Isocyanate organosilanes containing single functional isocyanate groups are known, such as through the disclosure of U.S. Pat. No. 4,736,046 wherein beta-isocyanatoethoxysilanes are disclosed. However, these monosubstituted nonpolymeric materials are ineffective for uses such as crosslinking or polymer chain extension, and thus do not effectively allow for the incorporation of the properties of silicones into these areas of usage.
The present invention is directed to novel polyorganosiloxanes having pendant therefrom specific isocyanate moieties. The present invention is further directed to, in a preferred embodiment thereof, to di-, tri- and polyisocyanate compounds which may be utilized in the above-mentioned functions.
SUMMARY OF THE INVENTION
The present invention is directed to a polyorganosiloxane of the following nominal formula. ##STR1## wherein R, which may be the same or different, represents an alkyl group having from 1 to about 8 carbon atoms;
R' represents hydrogen;
R" represents the group ##STR2## Q represents either R or hydrogen; X is an integer having a value ranging from 0 to about 200;
Y is an integer having a value ranging from 0 to about 200; and
Z is an integer having a value ranging from 1 to about 200; with the proviso that Q is hydrogen if Y is zero.
In a preferred embodiment thereof, the present invention further relates to a cyclic polyorganosiloxane having the following nominal formula. ##STR3## wherein R, R', and R" have values as set forth above; a is an integer having value a ranging from 0 to about 10;
b is an integer having a value ranging from 0 to about 10; and
c is an integer having a value ranging from 1 to about 10, with the proviso that Q is hydrogen if Y is zero.
The present invention further relates to a process for the production of the compounds identified in Formulae I and II above.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to the production of polyorganosiloxanes, both linear and cyclical, having at least one aliphatic isocyanate group pendant thereon. The present invention further relates to a process for the production of said polyorganosiloxanes.
The polyorganosiloxanes produced in the practice of the present invention have the following nominal formula. ##STR4## wherein R, which may be the same or different, represents an alkyl group having from about 1 to about 8 carbon atoms;
R' represents hydrogen;
R" represents the group ##STR5## Q represents either R or H; X is an integer having a value ranging from about 0 to about 200;
Y is an integer having a value ranging from about 0 to about 200; and
Z is an integer having a value ranging from about 1 to about 200, with the proviso that Q is hydrogen if Y is zero.
Preferably, R, which may be same or different, represents an alkyl group having 1 to about 4 carbon atoms;
R" is either a, a' - dimethyl meta-or para-isopropenyl benzyl isocyanate
Q is R;
X is an integer having a value ranging from 0 to about 50;
Y is an integer having a value ranging from 0 to about 50; and
Z is an integer having a value ranging from 1 to about 50.
Further, the sum of X, Y and Z preferably ranges from 2 to about 50.
Most preferably, R represents a methyl group;
R" is derived from a, a' - dimethyl meta-isopropenyl benzyl isocyanate;
X is an integer having a value ranging from 0 to about 20;
Y is an integer having a value ranging from 0 to about 20;
Z is an integer having a value ranging from 2 to about 20; and the sum of X, Y and Z is no greater than 20.
The polyorganosiloxanes of the present invention can be prepared by means well known to those skilled in silicone chemistry. For example, the precursor of the polyorganosiloxanes of this invention, have the nominal formula: ##STR6## wherein the variables are as previously defined with the proviso that Q is hydrogen if Y is zero. These compounds can be conveniently prepared by reacting a mixture containing hexamethyldisiloxane, octamethylcyclotetrasiloxane, trimethyl end blocked methyl hydrogen polysiloxane and an acid catalyst. The number of repeating units can be varied, as desired, by varying the mole ratio of the reactants. A specific procedure for preparing compounds falling within the scope of the Formula (III) is set forth in Example 2 of U.S. Pat. No. 4,046,930 granted Sep. 6, 1977.
Compounds of Formula III are then reacted with α,α-dimethyl meta or para-isopropenyl benzyl isocyanate. The meta isomer is commercially available from American Cyanamid Company which markets it under the trademark of m-TMI (which designation will be used hereinafter to refer to this reactant and to describe the remaining aspects of the invention). Preferably, m-TMI is purified prior to its reaction with the reactant of Formula III. This may be accomplished for example through vacuum distillation under an inert gas, such as nitrogen.
The molar amount of m-TMI introduced to form the reaction mixture with Compound III depends upon the degree of reaction over the Si--H linkage sought and can readily be adjusted accordingly by one of average skill in the art. If complete reaction of all Si--H linkages is desired, excess m-TMI should be introduced and any excess can be readily removed from the resulting product mixture.
The reaction of m-TMI and the Compound III is conducted at a reaction temperature of from about 20 to about 120° C., preferably about 25° to about 80° C., in the presence of a catalyst to induce reaction of the double bond present on m-TMI with the Si--H linkage in Compound III. Among the catalysts generally useful in the reaction are compounds of a platinum group metal, especially platinum-olefin complex catalysts such as those disclosed in U.S. Pat. Nos. 3,159,601; 3,159,662;3,220,972;3,775,452 and 4,808,634, the contents of which are hereby incorporated by reference. The preferred platinum group metals are platinum and rhodium, although ruthenium-based catalysts may also be employed. Specific catalysts useful in the practice of the present invention include chloroplatinic acid, endocyclopentadiene platinum and platinum divinyl tetramethyldisiloxane.
The catalyst (calculated as the weight of metal) should be present in the reaction mixture in quantities ranging from about 1 to about 250 ppm, based on the weight of the polyorganosiloxane reactant. The catalyst may be present in greater amounts although this is generally uneconomical and leads to coloration of the final product which is often undesirable. Preferably, the catalyst is present in amounts ranging from about 5 to about 100 ppm on the same basis.
Reaction times will very according to reaction temperature and catalyst content and may range up to 50 hours in order to completely react the Si--H linkages although reaction times of 6 to 24 hours are preferred. Additional catalyst may be introduced into the reaction mixture during the course of the reaction to aid in its completion.
The reaction is then carried out through the maintenance of the above described reaction temperature until the reaction proceeds to the desired degree. This can be determined by measuring the presence of Si--H linkages through such means as 'H-NMR. Any m-TMI present upon reaction completion can be removed such as by the application of high vacuum and elevated temperature, thereby isolating the final product, Compound I. Compounds of Formula II may be prepared in a similar fashion to that above except that a cyclic siloxane reactant is initially substituted for Compound III.
Cyclic siloxanes are commercially available to use in the production of compounds of Formula II. Preferred in the practice of this aspect of the present invention are cyclic siloxanes wherein the sum of a, b and c is no greater than 10. Most preferably, the sum of a, b and c does not exceed 6. Especially useful in the practice of this embodiment of the present invention is tetramethylcyclotetrasiloxane. Compounds of Formula II may further be converted to acyclic molecules through treatment with base.
In addition to the above-described polyorganosiloxane reactants, other organo-hydrosilane oligermers, polymers and copolymers should be useful in the practice of the present invention. These include 1,1,3,3-tetramethyldisiloxane.
The products of the present invention are useful as precursors for star polymers or starburst dendrimers or as crosslinking agents. Further, the compounds claimed herein can be further reacted with agents reactive with the aliphatic isocyanate moiety pendant thereon. For example, dialkanol amine may be reacted with a compound within Formula II via its amine group to yield a polyol useful in the production of starburst polymers such as those which are generally disclosed in Macromolecules 19, p. 2466 (1988). Reactions with polyalkylene glycols and diamines produce network polymers having urethane and urea linkages, respectively.
Whereas the scope of the instant invention is set forth in the appended claims, the following specific examples are provided to further illustrate certain aspect of the present invention. These examples are set forth for illustration only and are not to be construed as limitations on the present invention. All parts and percentages are by weight unless otherwise specified.
EXAMPLE
The isocyanate m-TMI(100 grams) was vacuum distilled under a slow flow of nitrogen. The fraction boiling at 127°-128° C./12.7 mm Hg was then collected for use in the hydrosilation reaction.
Tetramethylcyclotetrasiloxane (10.grams, 0.0395 moles) was mixed with the freshly distilled m-TMI (50 grams, 0.2488 moles) in a three neck flask. To the resulting clear solution was added 0.3 ml of a 3% solution of platinum divinyltetramethyldisiloxane in xylene. The mixture was then heated under nitrogen at 40° C. The reaction was continued until no SiH absorption could be detected in the 'H-NMR spectrum. Total reaction time was 30-40 hours. In the latter stages of the reaction, a small quantity of fresh catalyst was added to complete the reaction. Excess m-TMI was removed under high vacuum at a temperature of about 120° C.
The product, a slightly colored viscous liquid was analyzed by IR, NMR, gel permeation chromatography and elemental analysis, the results of which are set forth below. 1 HNMR (CDCl 3 )W-0.90(Si--CH 3 ,s,3); 0.93(Si--CH 2 ,d,2); 1.30 (CH--CH 3 ,d3); 1.69 (C--CH 3 ,s,6); 2.95 (CH,m,1); 7.10 (arom CH,s,1); 7.30 (arom CH,m,3). 13 C NMR (CDCl 3 ), w, 1.51 (SiCH 3 ); 25.55 (CH 3 ); 27.22 (Si--CH 2 ); 33.10 (C--CH 3 ); 35.35 (CH); 60.77 (C--N); 121.82, 122.75, 125.30, 128,53 (arom C); 123.27 (C═O). Anal. Calc., C 64.33; H 7.33; N 5.35. Found, C 64.02; H 7.34; N 5.30.
The absence of a SI--H absorption in the 1 H NMR spectrum of tetra[2-methyl-2{3-(1-isocyanato-1-methylethyl) phenyl}ethyl]tetramethyl cylcotetrasiloxane, (abbreviated as D4TMI) and represented schematically below, suggests complete substitution of the silanic hydrogen by m-TMI. This is was confirmed by the results of elemental analysis and by GPC. The gel permeation chromatogram depicted only one sharp peak with a very small shoulder on the higher molecular weight side. The latter may result from the reaction of m-TMI with pentamethylcyclotetrasiloxane, a likely impurity in tetramethylcyclotetrasiloxane which typically has a purity of about 95%. The 13 C NMR spectrum only showed the expected carbon absorptions. From all observations, it appeared that the conversion to the tetrafunctional aliphatic isocyanate D4TMI is quantitative. The color of the product is believed to be due to the presence of the platinum catalyst which may be removed through the application of such treatments as contact with activated charcoal.
EXAMPLE 2
The procedure of Example 1 is followed except that the polyorganosiloxane reactant was replaced with polymethylhydrodimethylsiloxane. A small amount of toluene was further added to lower the viscosity of the reaction mixture. The resulting product is a linear polysiloxane containing pendant aliphatic isocyanate groups. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to vehicle hood latches, and particularly to a latch construction wherein the primary latching member and the secondary latching member are each remotely operated (e.g. cable operated).
2. Description of Related Prior Art
Conventional vehicle hood latch systems typically include a striker on the hood, a primary latching member on the vehicle body engageable with the striker to hold the hood in the closed position, and a secondary latching member on the vehicle body in the path taken by the striker from the latched condition. The secondary latching member acts as a redundant safety device to prevent the hood from opening in the event that the primary latching member might disengage during service.
Very often the primary latching member is cable-operated from inside the vehicle. The secondary latching member is directly operated (e.g. by a handle). The secondary latching member usually has an actuating handle that is accessible to a person's fingers when the person is standing in front of the vehicle. The actuating handle must be pushed or pulled in a specific direction in order to release the secondary latching member from the striker.
The process of reaching and operating the handle of the secondary latching member may be difficult for some motorists who may not be aware of the handle construction or movement direction required to disengage the secondary latching member from the striker. The process may be more difficult during the nighttime, or when the vehicle is in a dark environment; the operation must then be carried out, using only the sense of feel to find and operate the handle. Also, the process inevitably results in the person's hand becoming dirty from atmosphere dirt accumulation on the vehicle surfaces.
U.S. Pat. No. 2,256,465 to K. Brubaker discloses an automobile latch system wherein the primary and secondary latching members are both operated from within the vehicle via a cable operator. However, the primary latching member is embodied in an over-center linkage that does not provide positive retention of the primary latching member. Under some conditions, e.g. high wind, lift forces on the hood could cause disengagement of the primary latching member.
The present invention relates to a reliable automotive hood latch system wherein both the primary latching member and the secondary latching member are cable-actuated from within the vehicle. The motorist is not required to leave the vehicle and insert his hand into a restricted space at the front edge of the hood in order to disengage the secondary latching member from the striker.
SUMMARY OF THE INVENTION
The invention contemplates an automotive hood latch construction that includes a primary latching member and an auxiliary latching member located within a housing in the path of a striker located on the vehicle hood. A single manually operated control means is provided for opening both latching members; preferably the control means includes a cable operator leading back to the vehicle passenger compartment, whereby the driver of the vehicle can completely release the hood without leaving the vehicle.
The control means and latching members are interconnected so that the primary latching member is disengaged from the striker during a first reciprocation of the cable operator; the secondary latching member is disengaged from the striker during a second reciprocation of the cable operator.
The double reciprocation requirement is a safety feature designed to prevent accidental opening of both latching members by a single inadvertent actuation of the cable operator.
In preferred practice of the invention, the primary latching member includes a hook for holding the striker in the latched position, and a spring means for causing the primary latching member to exert a lifting force on the striker when the hook is withdrawn from the striker.
The primary latching member is normally restrained in the latching position by a lever equipped with a detent. The cable operator can be reciprocated to withdraw the lever from the primary latching member, whereupon the primary latching member applies a lifting force to the striker.
The auxiliary latching member has a lost motion connection to the lever so that during the initial reciprocation of the cable operator, the auxiliary latching member remains in position to intercept the striker and thereby prevent the hood from opening. During a second reciprocation of the cable operator, the lever withdraws the auxiliary latching member from the striker, such that the striker is elevated to a cleared condition under the impetus of the spring-biased primary latching member. The primary latching member serves as a latch and also as a lifter device for the striker.
Further features and details of the invention will be apparent from the attached drawings and description of an illustrative embodiment of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a hood latch mechanism embodying the invention. A typical housing for the mechanism is shown in section.
FIG. 2 is a fragmentary sectional view taken on line 2--2 in FIG. 1.
FIG. 3 is a view taken in the same direction as FIG. 1, but showing the mechanism in a partially unlatched condition.
FIG. 4 is a view taken in the same direction as FIG. 1, but showing the mechanism in a fully unlatched condition.
FIG. 5 is a view taken in the same direction as FIG. 4, but with the manual control means returned to a standby inactive condition.
FIG. 6 is a view taken in the same direction as FIG. 1, but showing another form that the invention can take.
FIG. 7 is a view of the FIG. 6 latch mechanism taken in a partially unlatched condition.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to the FIG. 1, there is shown an automotive hood latch of the present invention, comprising a housing 10 containing a primary latching member 12, secondary latching member 14, and control lever 16. Typically, housing 10 will be mounted on the vehicle body at the upper edge of the front grille so that latching bolt members 12 and 14 are in the path of a striker 18 located on the vehicle front hood.
As shown in the drawing, the striker is a circular rod or bar movable in a generally vertical direction indicated by arrow 20. FIG. 1 shows striker 18 in three different positions: namely, a lowered position 18a; an intermediate position 18b; and a raised position 18c.
In the lowered position 18a, the striker is fully latched by primary latch bolt 12, so that the vehicle hood is retained in a fully closed position; hook 22 on the primary latch bolt 12 overlies striker 18 to prevent upward movement of the striker.
In the intermediate position 18b, the striker is released from hook 22, but is restrained against upward movement by a second hook 23 on the secondary (auxiliary) latch bolt member 14. Latch member 14 serves as a safety device to prevent the vehicle hood from opening in the event that primary latching member 12 breaks or otherwise fails to operate in the intended fashion.
In the raised position 18c, the striker is elevated beyond both latch bolts 12 and 14, such that the vehicle hood is free to be opened, e.g. manually or by some power mechanism.
The two latch members 12 and 14 are controlled and operated by a manual control means that includes a lever 16 having a pivot axis 25, and a cable 27 having one end connected to the lower end of the lever. A tension spring 29 normally holds lever 16 in the FIG. 1 position against a stop 30. Cable 27 extends out of housing 10 and through the engine compartment into the passenger compartment, where it is attached to a handle 32. The handle can be pulled to swing lever 16 away from stop 30, e.g. to the position shown in FIG. 4. When handle 32 is released, spring 29 returns the cable and lever 16 to the FIG. 1 condition.
Referring particularly to primary latch member 12, said member comprises a flat plate having a pivotal connection 34 with housing 10. The plate has a notch 36 extending radially from the pivot axis 34 to form the aforementioned hook 22. Notch 36 has a lower edge surface 37 that merges with an arcuate cam surface 39. This cam surface can exert a lifting action on striker 18 when the latch member rotates in a clockwise direction. In this regard, it will be seen from FIG. 3 that a clockwise rotation of the latch member of about twenty-three degrees (Angle A) lifts striker 18 to the partially unlatched position 18b. In the FIG. 3 position the striker is substantially disengaged from latch member 12; i.e., hook 22 no longer restrains the striker from upward movement.
Returning again to FIG. 1, the primary latching plate 12 has an abutment surface 40 contiguous with cam surface 39 and engageable with an overhanging detent surface 41 on lever 16. Lever 16 is a flat plate element coplanar with the primary latching plate 12. In the FIG. 1 condition, the detent surface on lever 16 prevents latching plate 12 from moving upwardly from the FIG. 1 position.
A wire spring 43 encircles the pivot shaft 34 for latching member 12, whereby the latching member is spring-biased in an upward direction, as indicated by arrow 44 in FIG. 1. The latch bolt is potentially in position to exert a lifting force on striker 18, via cam surface 39. Detent surface 41 normally restrains the latching member against upward swinging motion.
Latch bolt plate 12 has a linear slot 45 that accommodates a pin 47 carried by link 49. This link has a pivotal connection 50 with lever 16, such that when the lever swings in a leftward direction (from the FIG. 1 position), the link does not prevent upward swinging motion of latching plate 12. One function of slot 45 is to reset link 49 to the FIG. 1 position when the latch members 12 and 14 are subsequently returned from the FIG. 5 position to the FIG. 1 position (e.g. when the vehicle hood is moved downwardly to the latched condition).
Referring particularly to secondary (auxiliary) latch member 14, said member comprises a flat plate located in a plane parallel to the primary latching plate 12; as viewed in FIG. 1, latching member 14 is located behind plate 12. Latching plate 14 has a pivot connection 52 with the housing, whereby the plate can swing in an arcuate direction as indicated by arrow 53 in FIG. 1. A wire coil spring, encircles the pivot shaft 52 to exert a clockwise biasing force on latching member 14. Latching member 14 is normally spring-biased to the FIG. 1 position against a stop 26. The pivots 25 and 52 for lever 16 and latch bolt 12 are located at approximately the same elevation in housing 10. Also, striker 18 is located on a common horizontal plane with pivots 25 and 34 when the striker is in its lowered position.
The secondary latching member 14 has a slot 54 that accommodates the aforementioned pin 47. As shown in FIG. 2, link 49 is located in a plane (space) between primary latching plate 12 and secondary latching plate 14; pin 47 extends transversely through link 49 so as to be simultaneously within slot 45 and slot 54. The purpose of slot 54 is to provide a lost motion connection between link 49 and auxiliary latching plate 14, whereby initial reciprocation of lever 16 has no effect on latching plate 14; i.e. plate 14 remains in the FIG. 1 position when latch bolt 12 moves from the FIG. 1 position to the FIG. 3 position. When lever 16 is reciprocated a second time, an edge surface of slot 54 is engaged by pin 47 to move latching plate 14 out of the path of striker 18, thereby releasing the vehicle hood for movement to the open position.
FIGS. 1, 3, 4 and 5 show the latching and control mechanisms in various operating positions. FIG. 1 shows primary latching member 12 in the latched position wherein striker 18 is restrained against upward movement by hook 22. FIG. 3 shows the striker released from primary latching member 12, but restrained by secondary latching member 14; member 12 is spring-biased upwardly to lift striker 18 to the intermediate position 18b. FIG. 4 shows striker 18 in its elevated position 18c, released from both latch members 12 and 14. FIG. 5 shows lever 16 moved rightwardly against stop 30, whereby the secondary latch member 14 is reset to its normal position engaged with stop 26.
Comparing FIGS. 1 and 3. when a pulling force is applied to handle 32, lever 16 is moved from the FIG. 1 position to the FIG. 3 dashed line position 16a. This separates detent 41 from abutment 40, whereupon spring 43 causes latch member 12 to exert a lifting force on striker 18. Striker 18 moves upwardly from position 18a to position 18b.
Hook 23 prevents the striker from further upward movement. When handle 32 is released, spring 29 returns lever 16 to the full line position (FIG. 3).
When handle 32 is pulled a second time, the latch mechanisms take the positions depicted in FIG. 4. Pin 47 exerts a leftward force on edge surface 56 of slot 54, whereby secondary latch member 14 is swung to the left so that hook 23 moves out of the upward path taken by striker 18. Spring 43 exerts an upward biasing force on primary latch member 12, whereby cam surface 39 exerts a lifting force on striker 18, such that the striker is raised to the elevated position 18c.
When handle 32 is released, spring 29 returns lever 16 to the FIG. 5 position, wherein the mechanism is reset for the next latching cycle. FIG. 5 represents the released position wherein the vehicle hood is open, or at least in condition to be opened without interference by the latch mechanism. It should be noted that two reciprocations of the manual control means 32, 37, 16 are required to go from the FIG. 1 latched condition to the FIG. 5 released condition. During the first reciprocation of cable operator 27, striker 18 moves from the FIG. 1 latched condition to the FIG. 3 partially latched condition. During the second reciprocation of cable operator 27, striker 18 moves from the intermediate (partially latched) condition 18b to the FIG. 5 elevated condition 18c (fully released).
During the next latching cycle, the striker moves downwardly along path 20 to swing primary latching member 12 counterclockwise around pivot 34; secondary latch member 14 is momentarily deflected and then returned to the FIG. 1 position under the impetus of spring 55. Also, abutment 40 on latching member 12 snaps into engagement with detent surface 41 on lever 16; the lever may momentarily deflect away from stop 30 as edge surface 15 of latching member 12 rides along the lever edge surface 17.
Slot 54 is configured to provide adequate clearance for pin 47 during the reset period, i.e. from the FIG. 5 position to the FIG. 1 position. An important feature of the invention is that the complete cycle is accomplished by a double reciprocation of the manual control means 32, 27, 16. Both latch members 12 and 14 are operated remotely from within the passenger compartment. It is not necessary for the motorist to leave the vehicle and manually contact either latch member directly.
Some variations in construction and arrangement may be used while still practicing the invention. FIGS. 6 and 7 show one alternative arrangement that can be used. FIG. 1 represents the preferred embodiment. FIG. 6 is the less preferred form of the invention.
Referring to FIG. 6, primary latching member 12 is similar to the corresponding FIG. 1 latching member except that it has no linear slot (i.e. slot 45). Latching member 12 has a pin 60 engaged against link 49 when member 12 is in the FIG. 6 latched position.
Lever 16b has a linear slot 45a that performs essentially the same function as slot 45 in the FIG. 1 embodiment; the linear slot is formed in the lever rather than in the link.
Link 49 is a flat plate element positioned between primary latching member 12 and secondary latching member 14. The link has a transverse pin 47 extending within slot 45 in lever 16b and slot 54a in the secondary latching member 14. Slot 54a serves the same function as slot 54 in the FIG. 1 embodiment. The right end portion of link 49 has a linear slot 62 encircling the fixed pivot shaft for latching member 12. Slot 62 serves as a mechanism for allowing link 49 to pivot and also slide in the longitudinal direction (i.e. in the length dimension of the link). The left end of link 49 is connected to a tension spring 64 that is suitably anchored to the latch housing. Aforementioned pin 60 engages link 49 to prevent spring 64 from swinging the link upwardly when latching member 12 is in the FIG. 6 position.
Secondary latching member 14 has a fixed pivot shaft 52 and a coil spring 55 for biasing the latching member clockwise into engagement with stop 26. As previously noted, latching member 14 has a slot 54a engaged with transverse pin 47 carried by link 49.
FIG. 7 shows the FIG. 6 latching mechanism in the partially unlatched condition wherein striker 18 is lifted to the intermediate position 18b, substantially disengaged from hook 22 on the primary latching member 12. The FIG. 7 condition is achieved by a first reciprocation of cable operator 27, such that lever 16b is swung to the dashed line position (FIG. 7) and then returned to the initial position against stop 30. When lever 16b moves to the dashed line position, detent surface 41 on the lever moves out of the path of abutment 40, such that tension spring 43a is enabled to exert an upward lifting force on latching member 12. Cam surface 39 exerts a lift force on striker 18, whereby the striker is moved upwardly until it comes in contact with hook 23 on the secondary latching member 14.
A second reciprocation of cable operator 27 causes lever 16b to swing back and forth in the previously described fashion. As the lever swings leftwardly from the FIG. 7 position (to the dashed line position), pin 47 exerts a leftward force against an edge of slot 54a, whereby the secondary latching member 14 is moved out of the path of striker 18. Tension spring 43a moves latching member 12 upwardly so that cam surface 39 lifts the striker 18 to the raised position 18c.
When spring 29 returns lever 16a to its normal position (contacting stop 30), the two latching members 12 and 14 will be in the positions similar to the positions depicted in FIG. 5; the striker is then fully released from the two latching members 12 and
It will be seen that the FIG. 6 construction operates in the same fashion as the FIG. 1 construction. In both cases the striker is released from the primary and secondary latching members by a double reciprocation of the cable operator. A principal feature of the invention is that both latching members are operated remotely from the passenger compartment. The motorist does not have to leave the vehicle in order to release the vehicle hood for hood-operating purposes.
In both illustrated forms of the invention, the primary latch bolt 12 is retained in the latching position by engagement of detent surface 41 against abutment Detent lever 16 (or 16b) is held in the operating position (FIG. 1 or FIG. 6) by a spring 29, such that latch bolt 12 is securely held in the latching position. The lever-latch bolt relationship depicted herein is believed to have a more secure locking action than the primary latch member used in aforementioned U.S. Pat. No. 2,256,465. | 4y
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FIELD OF THE INVENTION
The present invention relates to an information recording medium, for example a magneto-optical recording medium.
BACKGROUND OF THE INVENTION
An optical disc is characterized by its high data density, large data capacity and high speed data access, and various research and development programs are presently in progress. For a recording medium of one type of optical disc which allows an additional recording only once, TeOx, TeC, Te-Sn-Se and the like are known in the art and some of them have been already marketed.
With an optical disc dedicated to playback, the playback on both sides of the disc is realized by using a disc wherein two recording layers each having a reflection layer of Al are bonded to each other with a hot-melt adhesive as disclosed in Japanese Patent Publication Open to Public Inspection (hereinafter referred to as Japanese Patent O.P.I. Publication) No. 6538/1983. An optical disc with which information is recorded by providing microscopic holes (known as pits) on a recording layer with a laser beam has an air-sandwich structure, as shown in FIG. 4, with which the adhesion is provided on the inner and outer circumferencial areas of a disc where a recording layer 1 does not exist. In such an example, a heat-hardening type epoxy adhesive or an ultraviolet-ray-hardening adhesive is used as an adhesive 6 to bond both supports 4 and 5 to each other via spacers 2 and 3 to enclose air space 7. Other than these adhesives, a two-liquid type normal-temperature-hardening epoxy adhesive may be also used. At the same time, as an erasable optical recording system, the magneto-optical recording system has attracted attention.
Some of magneto-optical recording media, for example, an optical disc, involve transparent supports on which a magnetic alloy layer composed of at least one of rare earth elements such as Sm, Eu, Gd, Tb, Dy, Ho, Er and the like as well as at least one of transition elements such as Fe, Co, Ni and the like is formed through sputtering or vacuum depostion to form an amorphous layer, whereupon a protective layer comprising organic substances may be coated in order to provide wear resistance.
With an magneto-optical disc, there is no need for the air sandwich structure, mentioned above. Accordingly, it is advantageous in terms of cost to bond the whole surface with the counterpart.
However, such a magneto-optical recording medium has as a recording layer a very corrosive material for example Gd, Tb or Fe. When two recording layers are bonded to each other by the above-mentioned hot-melt adhesive, the layers are readily corroded with such an adhesive. Therefore, such an adhesive is unusable for magneto-optical disc. Additionally, the recording layer transmits only a little amount, if any, of ultraviolet rays. Consequently, an ultraviolet-ray-hardening adhesive cannot be used to mutually bond two supports each having a recording layer. Additionally, such supports having a recording layer are hereinafter called recording elements. When an epoxy adhesive is used, a two-liquid-mixing type of the similar adhesive involves a complex process control, and, furthermore, insufficient mixing of two liquids may cause corrosion of the layer, because the hardener itself corrodes Gd, Tb and Fe. With a mono-liquid heat-hardening type of the similar adhesive, it is difficult to use a plastic for the recording element because of the heat deformation. Also, it is impossible to avoid thermal degradation of the recording layer. The production cost is higher, as this type of adhesive necessitates the provision of hardening furnace.
Though a mono-liquid-hardening type polyurethane adhesive and the like are useful adhesives as their mono-liquid non-solvent component hardens at normal temperature range, without corroding a recording layer. However, with this type of adhesive, the hardening process is slower and takes more than one day if it is left in an ordinary room, resulting in the poor productivity.
Additionally, it is technically difficult to apply a fast-hardening adhesive, such as a cyanoacrylate adhesive, upon the larger area such as the surface of disc, and the adhesive itself is expensive.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide an information recording medium such as an magneto-optical disc or the like wherein the bonding of recording elements is effected with a safe adhesive which does not corrode a recording layer, whereby the curing time, that is, the time span from the moment when both the elements are adhered to each other to the moment both the elements are tightly secured to each other, is greatly reduced.
The above object of the invention is accomplished by an information recording medium comprising two pieces of recording elements each comprising a support and a recording layer provided on a part of one surface of the support, wherein the two pieces of elements adhere face to face of said two faces to each other by a non-corrosion causing adhesive provided on a part of the surface where a recording layer is provided and a fast-hardening adhesive provided on the other part of the surface where no recording layer is provided.
More specifically, in adhering two pieces of recording elements to each other, the adhesive for the area containing information recording layer differs from the adhesive for the area containing no information recording layer. The adhesion is effected for the former area with a safe adhesive which does not corrode the information recording layer, and the adhesion for the latter area is carried out with a fast-hardening adhesive in order to reduce the curing time.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-3 exemplify the present invention: where,
FIG. 1 is a sectional view illustrating the adhesion of two information recording elements; and,
FIG. 2 is a plan view of one of the two elements; and
FIG. 3 is an enlarged fragmentary sectional view through a part of the already adhered photo-magnetic recording medium which contains two recording elements; and
FIG. 4 is a sectional view illustrating an optical disc having a conventional air-sandwich structure.
DETAILED DESCRIPTION OF THE INVENTION
According to the present invention, two or more of the above-mentioned adhesives may be employed. However, at least one of adhesives employed is of fast-hardening type. Such a fast-hardening adhesive is used to adhere the areas each having no information recording layer to each other. And, an adhesive which does not corrode the information recording layer is used, even though it is slow in hardening, to adhere the respective areas each of which has an information recording layer to each other.
The above-mentioned fast-hardening adhesives are preferably the adhesives which readily harden at the normal temperature and are exemplified by an ultraviolet-ray-hardening adhesive, cyanoacrylate adhesive, reaction-type acrylic adhesive and the like. The above-mentioned adhesives which do not corrode the information recording layer is preferably a mono-liquid moisture-hardening polyurethane adhesive and the like.
Among the examples of ultraviolet-ray-hardening adhesive, mentioned above, an ultraviolet-ray-hardening resin of cation-polymerization type especially, can avoid the permeation of oxygen and moisture, improving the corrosion resistance. Such a resin contains a primary components a resin as well as a cation polymerization initiator. As a resin, epoxy resins are favorable, and the examples of which include bisphenol A, polyglycidyl ether which is derived from a multifunctional alcohol as well as epichlorohydrin. Other suitable resins include resin series epoxides such as the following: ##STR1##
The examples of such a polymerization initiator include such complexes as a diazonium salt, sulfonium salt, iodonium salt and the like which were disclosed in Japanese Patent Examined Publications No. 14277/1977, No. 14278/1977 and No. 14279/1977. More specifically the examples include the following: ##STR2##
Other usable ultraviolet-ray-hardening adhesives include acrylic series radical polymerization-type adhesives. Acrylate monomers and oligomers used in such adhesives include polyester types, epoxy types, polyurethane series and polyether types. The epoxy acrylate, below, is used with results as satisfactory as those of the above-mentioned cation polymerization type epoxy resins. ##STR3##
The above-mentioned cyanoacylate features excellent fast-hardening properties, and is available in the form of a product known as "Aron alfa" (manufactured by Toa Chemical Industry Co., Ltd.)
The favorable examples of above-mentioned reaction-type acrylic adhesive involves a two-liquid modified acrylic series adhesive (SGA manufactured by Cemedyne Co., Ltd. or Du Pont Japan Ltd.) wherein a mixture of elastomer and acrylic monomer rapidly hardens due to a redox system hardening mechanism. Such an adhesive is available in the form of either primer or two-liquid component type, however, the two-liquid component type may be sometimes advantageous in terms of stable properties.
As shown below, the above-mentioned mono-liquid moisture-hardening polyurethane adhesives, applicable to the present invention, involve a polyisocyanate which is prepared in such a manner that a compound having a plurality of isocyanate groups in one molecule and another compound having a plurality of hydroxy groups in one molecule such as a polyal are allowed to react to each other in the presence of excess isocyanate in order to provide the resultant molecute having plurality of isocyanate groups on the end groups. ##STR4## The hardening mechanism of this adhesive is as follows. ##STR5## The polyisocyanates used for such a purpose include aromatic ones such as toluenediisocyanate, diphenylmethanediisocyanate and the like as well as aliphatic ones such as hexamethylenediisocyanate and the like.
As a polyol, 1,4-butanediol, 1,5-pentandiol, polyetherglycol or the like is employed.
The specific esamples of such polyurethanes include Imron manufactured by Du Pont Japan Ltd. Mondol 152 manufactured by Movoy Chemical Co., Ltd., Coronate 2013 manufactured by Nippon Polyurethane Industry Co., Ltd. and the like.
An information recording layer, especially, a photo-magnetic recording layer, which is advantageously used as an information recording medium of the invention, has an easy axis for magnetization vertical to the layer surface. With such a layer, information can be recorded, reproduced or erased by an optical beam. The layer may be composed of a known material, that is, an amorphous alloy comprising both a rare-earth element and transitional metallic element and is exemplified by TbFe, GdFe, GdTbFeCo, GdCo or the like. The layer may be, as known in the art, formed through sputtering.
A dielectric layer is usually provided on the photo-magnetic recording layer. The examples of such a dielectric substance include Si 3 N 4 , AlN, SiO 2 , ZnS, ITO (Indium Tin Oxide) and others. Such a dielectric layer can be laminated upon a magneto-optical recording layer through sputtering. Additionally, another dielectric layer may be provided between a magneto-optical recording layer and a support in order to sandwich the magneto-optical recording layer with two dielectric layers. Such a sandwich structure appears advantageous because the arrangement significantly reduces introduction of oxygen, which otherwise often occurs, from a support in the course of layer formation when a support made of resin is used.
Various materials are available for the material of a support and include plastics such as polyethyleneterephtharate, polyvinyl chloride, cellulose triacetate, polycarbonate, polyimide, polyamide and polymethylmethacrylate. The shape of support, or substrate, may be sheet, card, disc, drum or long-span tape.
FIGS. 1 and 2 give schematic drawings for one example of information recording medium according to the present invention. With this example, an information recording layer 11 is provided on one side of each disc-shaped support 10 to form each of two sheets of recording elements 12 which are bonded to each other after inwardly positioning each information recording layer 11. During this course, two types of adhesives are used for this example, wherein a non-fast-hardening type adhesive 13 is applied to form a larger ring on the area of information recording layer 11, and at a certain distance from the adhesive 13 a fast-hardening type adhesive 15, which readily hardens at the normal temperature range, is applied to form a smaller ring around the center hole 14. With such an arrangement to separately employ two types of adhesives 13 and 15, the previously mentioned operational effect of the invention is accomplished. If an ultraviolet-ray-hardening type resin is employed as a fast-hardening type resin 15, sufficient radiation of ultraviolet rays can be applied through the support 10, as the area around the center hole does not involve an information recording layer 11. Despite its corrosiveness the fast-hardening type adhesive 15 may have over the information recording layer 11, it does not exerts adverse effects upon the layer, because it is applied at a sufficient distance away, as mentioned above, from the information recording layer 11. By using the fast-hardening resin 15, two recording elements are bonded to each other in a short period of time. Accordingly, in spite of swift adhesion with excellent operation efficiency, the misalignment of two elements does not occur.
FIG. 3 illustrates one example of the above-mentioned information recording medium in the form of a photo-magnetic recording medium, wherein two pieces of recording element 12 each being provided with a lamination located on a support 10 and comprising a magnetic recording layer 11 which is sandwiched between the dielectric layers 23 and 24. The outer dielectric layers 24 are bonded with non-corrosive adhesive 13 in face to face relationship.
Additionally, it is possible to protect the substrate by coating an ultraviolet-ray-hardening adhesive on each recording layer and allowing the adhesive to harden prior to the above-mentioned bonding.
The present invention is described in detail, below, by referring to Examples.
EXAMPLE 1
Masking was provided on a polycarbonate support having external diameter 120 mm and internal diameter 15 mm in such a manner to expose a ring-shaped area having internal diameter 47 mm and external diameter 115 mm, where Si 3 N 4 , GdTbFe and SiN 4 each being 1000 Å thick was deposited through sputtering in order to form a layer on the support. Then, an ultraviolet-ray-hardening resin (SD-17 manufactured by Dainippon Ink & Chemicals, Inc.) was applied on the recording layer through spin coating in order to form a protective layer. Also, an ultraviolet-ray-hardening adhesive (Aronix UV 3033 manufactured by Toagosei Chemical Industry Co., Ltd.) was coated upon the inner area without the recording layer, and, at the same time, a mono-liquid moisture-hardening type polyurethane adhesive (Imron manufactured by Du Pont Japan Ltd.) was coated upon the area provided with a recording layer. Then two pieces of recording elements were bonded to each other with each recording layer being faced to the counterpart, whereby the disc was treated with ultraviolet-ray radiation.
The resultant photo-magnetic disc was immediately subjected to a recording/playback unit, and the recording/reproducing was effected without any disadvantages. Next, the disc was left under the conditions, 68° C. and 80% RH, for one month. The bit error rate of signal varied from 2×10 -6 before the above environmental test to 1×10 -5 after the test.
EXAMPLE 2
Instead of an ultraviolet-ray-hardening adhesive used in Example 1, a cyanoacrylate adhesive comprising Aron alfa manufactured by Toagosei Chemical Industry Co., Ltd. was applied dropwise in a circular pattern on the inner area having no recording layer. The two pieces of recording elements were bonded to each other by using a polyurethane adhesive. Immediately, the measurement was taken without any disadvantages. Additionally, the variation of bit error rates before and after the environmental test was exactly the same as Example 1.
COMPARISON EXAMPLE
One piece of disc having a protective layer and prepared in Example 1 was coated with a primary component of reaction-type acrylic adhesive (SGA manufactured by Cemedyne Co., Ltd.). The similar disc was coated with a hardener of the similar adhesive. Then, these discs were bonded to each other and in approximately five minutes showed a bonding strength sufficient for practical use. However, when the finished disc was left for one week at 60° C. and 80% RH, the bit error rate varied from 2×10 -6 to 3×10 -4 .
EXAMPLE 3
Instead of the ultraviolet-ray-hardening adhesive in Example 1 the SGA adhesive in Comparison example 1 was used, and, also, instead of the polyurethane adhesive in Example 1, a two-liquid-mixing type epoxy adhesive (Araldite manufactured by Showa High Polymer Co., Ltd.) was used. As a result, the finished disc showed in five minutes a bonding strength sufficient for practical use. The bit error rate varied from 2×10 -6 before the environmental test to 4×10 -6 after the test.
As can be understood from the above description, in the case of Comparison example, the bit error rate greatly deteriorated due to high corrosiveness of the reaction-type acrylic adhesive.
In contrast, excellent performance was attained with Examples 1 and 2 according to the invention. Additionally, in the case of Example 3, it seems that an insufficiently mixed portion was left in the course of mixing two liquids and the portion in turn caused the corrosion.
The present invention has been exemplified as shown above. However, the examples, above, may be further modified based on the technical concept of the invention. | 4y
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FIELD OF THE INVENTION
[0001] The present invention relates to a floor system for composting, and more particularly to a composting floor system that facilitates a forced aeration of the organic material within the compost pile and a capture of leachate generated during the process.
BACKGROUND OF THE INVENTION
[0002] Composting is a biological process which transforms organic materials into a stable, easily handled, and potentially valuable product called compost. Compost bins are commonly employed to contain a mixture of organic matter, such as vegetable refuse, municipal solid waste, sludge, manure, animal mortalities, and the like, for converting the same into useful compost for fertilizing and conditioning soil. The composting process requires a carbon source such as sawdust, a nitrogen source such as the organic matter listed above, moisture, and oxygen. A common approach to composting includes mixing and stacking the carbon source and the nitrogen source in a compost bin and introducing air to the mixture of organic materials through various means.
[0003] The composting process consumes large amounts of oxygen. Thus, an air or gas delivery means is typically used to introduce air or gas to the organic material. The delivery means commonly consists of compressed air supplied through perforated pipes or plates disposed on the base of the compost bin or pile. The pipes or plates are often damaged by associated equipment such as front-end loaders used during the unloading of compost from the bin.
[0004] The air delivery means used in prior art structures often results in insufficient amounts of oxygen being supplied to certain areas of the compost bin. Without sufficient oxygen, these areas within the composting bin tend to process at a slower rate than the rest of the material, and undesirable odors may emanate from the composting mixture.
[0005] In order to optimize the composting process, the moisture content of the mixed ingredients should be between 40 percent and 60 percent. Given these higher levels of moisture, and the natural inconsistency of the materials being composted, leachate will be generated. The floor systems used in prior art structures often require that parts of the floor be removed to clean out the leachate that accumulates during the composting process since leachate is allowed to drain through holes in the floor and collect underneath the floor. Thus, it becomes difficult to capture the leachate for disposal or reuse in the composting process.
[0006] Another method of reducing the leachate generated is to compensate for excess moisture by reducing the overall moisture content to a level where little or no leachate is generated. However, this practice significantly reduces the efficiency of the composting process, and increases the amount of time required to complete the composting process.
[0007] It would be desirable to produce a floor system for composting having a gas delivery system, wherein the flooring system facilitates drainage and collection of leachate generated during the composting process, and a collection of leachate and an efficiency and speed of aerobic composting are maximized.
SUMMARY OF THE INVENTION
[0008] Consistent and consonant with the present invention, a floor system for composting having a gas delivery system, wherein the flooring system facilitates drainage and collection of leachate generated during the composting process, and a collection of leachate and an efficiency and speed of aerobic composting are maximized, has surprisingly been discovered.
[0009] In one embodiment, the floor system for composting comprises a base portion having a plurality of trenches formed therein; a plurality of gas distribution conduits, each of the gas distribution conduits disposed in one of the trenches of the base portion and having a plurality of apertures formed therein, the plurality of gas distribution conduits adapted to be in fluid communication with a source of pressurized gas; and a header portion having a trench formed therein cooperating with the trenches of the base portion to facilitate drainage of leachate from the compost system, the header portion abutting an end of the base portion.
[0010] In another embodiment, the floor system for composting comprises a base portion having a plurality of trenches formed therein; a plurality of gas distribution conduits, each of the gas distribution conduits disposed in one of the trenches of the base portion and having a plurality of apertures formed therein, the plurality of gas distribution conduits adapted to be in fluid communication with a source of pressurized gas; a header portion having a trench formed therein cooperating with the trenches of the base portion to facilitate drainage of leachate from the compost system, the header portion abutting an end of the base portion; and a leachate collection conduit disposed in the trench of the header portion and adapted to be in fluid communication with one of a leachate storage system and a leachate treatment system, the leachate collection conduit having a plurality of apertures formed therein to facilitate a collection of the leachate in the leachate collection conduit to drain the leachate to the one of the leachate storage system and the leachate treatment system.
[0011] In another embodiment, the floor system for composting comprises a base portion including a plurality of block portions, each of the block portions having a trench formed therein; a plurality of gas distribution conduits, each of the gas distribution conduits disposed in one of the trenches of the block portions and having a plurality of apertures formed therein; a header portion having a trench formed therein cooperating with the trenches of the base portion to facilitate drainage of leachate from the compost system, the header portion abutting an end of the base portion; a gas supply header disposed in the trench of the header portion and providing communication between a source of pressurized gas and the gas distribution conduits; and a leachate collection conduit disposed in the trench of the header portion and adapted to be in fluid communication with one of a leachate storage system and a leachate treatment system, the leachate collection conduit having a plurality of apertures formed therein to facilitate a collection of the leachate in the leachate collection conduit to drain the leachate to the one of the leachate storage system and the leachate treatment system.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:
[0013] FIG. 1 is a partial perspective view of a composting floor system according to an embodiment of the invention;
[0014] FIG. 2 is a sectional view of the composting floor illustrated in FIG. 1 taken along line 2 - 2 ;
[0015] FIG. 3 is an end view of a gas supply header and a leachate collection conduit illustrated in FIG. 1 ;
[0016] FIG. 4 is an enlarged plan view of a gas supply conduit illustrated in FIG. 1 and showing apertures formed in the conduit;
[0017] FIG. 5 is a sectional view of the gas supply conduit illustrated in FIG. 4 taken along line 5 - 5 ;
[0018] FIG. 6 is a sectional view of the leachate collection conduit illustrated in FIGS. 1 and 3 ;
[0019] FIG. 7 is a partial perspective view of a composting floor system according to another embodiment of the invention;
[0020] FIG. 8 is an end view of a composting floor block portion showing an end of the block opposite the end abutting a header portion; and
[0021] FIG. 9 is an end view of a header portion showing the gas supply header and the leachate collection conduit illustrated in FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0022] The following detailed description and appended drawings describe and illustrate various exemplary embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner.
[0023] FIG. 1 illustrates a floor system 10 for composting according to an embodiment of the invention. A compost bin or pile (not shown) is disposed on the floor system 10 . A length and width of the floor system 10 can be adjusted to match that of the compost bin or pile. Walls (not shown) can also extend upwardly from a periphery of the floor system 10 .
[0024] The floor system 10 includes a base portion 12 and a header portion 14 . A plurality of spaced apart, substantially parallel trenches 16 are formed in the base portion 12 . Any desired cross sectional shape can be used for the trenches 16 such as a V-shape, a rectangular shape, or a rounded or semicircular shape, for example. The base portion 12 is sloped towards the header portion 14 . It is understood that a substructure 18 of the base portion 12 can be sloped to result in the desired slope of the base portion 12 .
[0025] The header portion 14 is disposed at an end of the base portion 12 . The slope of the base portion 12 is towards the header portion 14 . A trench 20 is formed in the header portion 14 to be substantially perpendicular to the trenches 16 of the base portion 12 . The trenches 16 of the base portion 12 are in fluid communication with the trench 20 of the header portion 14 . In the embodiment shown, the header portion 14 is not sloped. However, it is understood that the header portion 14 or the trench 20 of the header portion. 14 can be sloped as desired.
[0026] A leachate collection conduit 22 is disposed in the trench 20 of the header portion 14 . The leachate collection conduit 22 is in fluid communication with a leachate storage system (not shown), a leachate treatment system (not shown) as desired, or simply permitted to drain from the floor system 10 . As clearly shown in FIG. 6 , the leachate collection conduit 22 includes an annular array of apertures 24 formed therein. In the embodiment shown, the apertures 24 are disposed in the bottom portion of the leachate collection conduit 22 to facilitate the collection of leachate 26 . The apertures 24 permit the leachate 26 to enter the leachate collection conduit 22 and be removed from the floor system 10 . A direction of flow of the leachate 26 is indicated by the arrows L. A cap 28 is disposed at an end of the leachate collection conduit 22 to militate against leachate 26 escaping. However, it is understood that both ends of the leachate collection conduit 22 can be in communication with the leachate storage or treatment system.
[0027] A gas supply header 30 is disposed adjacent the leachate collection conduit 22 in the trench 20 of the header portion 14 . In the embodiment shown, air is used. However, it is understood that other gases such as a mixture of gases containing oxygen can be used. The gas supply header 30 is in communication with a source of pressurized gas (not shown) such as a pressurized tank or a fan, for example. Typically, it is desired to have the gas supply header 30 in the trench 20 at a higher point than the leachate collection conduit 22 as illustrated in FIG. 3 . An end cap 32 is disposed on an end of the gas supply header 30 to militate against the escape of gas therefrom.
[0028] A gas distribution conduit 34 is disposed in each one of the trenches 16 . The depth of the trenches 16 and the diameter of the gas distribution conduits 34 cooperate to maintain a top portion of the gas distribution conduits 34 at or below planar surface portions 35 . The gas distribution conduits 34 are in fluid communication with the gas supply header 30 . Flow of gas through the gas distribution conduits 34 is indicated by the arrows A. A valve (not shown) can be disposed between the gas supply header 30 and the gas distribution conduits 34 to control the flow of gas into each of the gas distribution conduits 34 . Additionally, a control system (not shown) can be used to regulate flow into the gas supply header 30 and the gas distribution conduits 34 as desired. The control system may include timers and valves, for example. An annular array of spaced apart apertures 36 are formed in the gas distribution conduits 34 , as clearly shown in FIGS. 2, 4 , and 5 . In the embodiment shown, the apertures 36 are disposed in the upper portion of the gas distribution conduit 34 to direct the flow of the gas upwardly. A diameter, quantity, and location of the apertures 36 can be varied to control the flow of the gas as desired.
[0029] In operation, organic material is disposed on the floor system 10 . The gas is supplied to the organic material by the gas supply header 30 and the gas distribution conduits 34 . The flow of gas is directed into the organic material by the apertures 36 formed in the gas distribution conduits 34 to facilitate the composting process. The oxygen supplied with the gas provides the needed oxygen to the aerobic microorganisms in order to begin the decomposition of the organic material. In one embodiment, the flow of gas into the organic material is accomplished by the alignment of the apertures 36 of the gas distribution conduits 34 in two rows spaced substantially ninety degrees apart as illustrated in FIG. 5 . However, it is understood that other configurations of the apertures 36 can be used without departing from the scope and spirit of the invention.
[0030] During the decomposition of the organic material, any leachate 26 or excess moisture formed is directed to the header portion 14 by the base portion 12 . The leachate 26 is caused to flow to the header portion 14 by the trenches 16 formed in the base portion 12 , the slope of the base portion 12 , or a combination of the trenches 16 and the slope. The leachate 26 is collected in the trench 20 of the header portion 14 . The leachate 26 is directed towards a collection point by the trench 20 . Additionally, the leachate 26 enters the leachate collection conduit 22 through the apertures 24 formed therein. Collected leachate 26 can be stored for later removal and treatment, can be directed to a treatment system (not shown), can be re-used in the composting process, or simply permitted to drain from the floor system 10 .
[0031] Once the organic material has been converted to compost material, the compost material can be removed from the floor system 10 . Any conventional removal method can be used such as by hand with a shovel or with a front end loader, as desired. The gas distribution conduits 34 are protected from damage during removal of the compost material since the top of the gas distribution conduits 34 are positioned at or below the planar surface portions 35 .
[0032] Another embodiment of the invention is illustrated in FIGS. 7, 8 , and 9 . Like structure from FIGS. 1-6 is shown in FIGS. 7-9 with the same reference numeral and a prime “′” symbol. In this embodiment, the base portion 12 ′ is produced from a plurality of elongate block portions 40 as shown in FIG. 8 . Each of the block portions 40 includes a protuberance 42 such as a tongue in a tongue and groove joint, for example, formed in one side thereof. A depression 44 such as a groove in a tongue and groove joint, for example, is formed in an opposite side thereof. When individual block portions 40 are disposed adjacent and substantially parallel with one another, the protuberance 42 of one block portion 40 is received in the depression 44 of an adjacent block portion 40 . Thus, a desired width of the base portion 12 ′ can be attained by placing block portions 40 in a side by side relation until the desired width is reached.
[0033] As shown in FIG. 9 , an end of the block portions 40 abutting the header portion 14 ′ has a depression 46 such as a groove in a tongue and groove joint formed therein. The depression 46 formed on the end of the block portions 40 receives a protuberance 48 such as a tongue in a tongue and groove joint formed on the header portion 14 ′. It is understood that a depression can be formed on the header portion 14 ′ and a protuberance can be formed on the ends of the block portions 40 without departing from the scope and spirit of the invention. The protuberances 42 , 48 and the depressions 44 , 46 facilitate an alignment between adjacent block portions 40 , and the block portions 40 and the header portion 14 ′, and militate against relative movement therebetween. Producing the floor system 10 ′ using the block portions 40 allows for large scale production, thus minimizing costs. The block portions 40 can be produced in a variety of lengths, thereby facilitating use in a variety of applications. The operation of the floor system 10 ′ is the same as previously described for the other embodiment of the invention.
[0034] The floor system 10 , 10 ′ produced according to the various embodiments of the invention facilitates the drainage, capture, removal, treatment, or reuse of excess leachate 26 , 26 ′ generated in the composting process. Additionally, gas supply is consistently and equally distributed throughout the organic material being composted. The floor system 10 , 10 ′ can be economically manufactured at one or more central facilities and transported to a desired site for efficient and simple installation. The floor system 10 , 10 ′ also readily accommodates variations in the width and length of the compost bin or pile.
[0035] From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions. | 4y
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The invention described and claimed hereinbelow is also described in European Patent Application EP 11006154.6, filed on Jul. 27, 2011. This European Patent Application, whose subject matter is incorporated here by reference, provides the basis for a claim of priority of invention under 35 U.S.C. 119(a)-(d).
BACKGROUND OF THE INVENTION
[0002] The present invention relates to an agricultural vehicle and a method of operation thereof.
[0003] Agricultural vehicles such as tractors, combine harvesters, forage harvesters and like have powerful internal combustion engines that are not operating continuously at their maximum rated power or at a fuel-efficient power level. It has been found that in only about 80% of the time such a vehicle and its driver spend working on a field a substantial amount of the engine power is indeed used. The remaining 20% of the time are spent waiting for other vehicles to finish their jobs, or in auxiliary activities such as maneuvering, coupling and uncoupling implements or trailers. All these activities require only a minute fraction of the power the internal combustion engine is capable of delivering.
[0004] Being optimized for high power operation, most internal combustion engines have mediocre efficiencies when running at low power, and considerable economies in fuel might be achieved if efficiency at low power could be improved.
SUMMARY OF THE INVENTION
[0005] The present invention overcomes the shortcomings of conventional operation of agricultural vehicles, such as those mentioned above.
[0006] To that end, the invention provides an agricultural machine which operates efficiently both at high and low power levels, and a method of operation therefore.
[0007] In an embodiment, the invention provides an agricultural vehicle comprising an internal combustion engine, an electric machine for driving one powertrain and a plurality of devices selectively drivable by the one powertrain. The powertrain comprises a first section associated to the internal combustion engine, a second section associated to the electric machine and to at least one of the plurality of devices and a first clutch for coupling the first and second section.
[0008] Preferably, the at least one device is a low power device which is likely to be used in a waiting state of the vehicle or in auxiliary operations, so that it can be operated driven by the electric machine operating as a motor while the internal combustion engine is off. By switching off the internal combustion engine when power demand is low, operation of the combustion engine at an inefficient power level can be avoided.
[0009] According to an embodiment of the invention, the at least one device is an air conditioning unit. The invention thus allows maintaining the air condition unit working while the vehicle is waiting, so that a comfortable temperature may be maintained in a driver cabin of the vehicle, although its internal combustion engine may not be working.
[0010] According to another embodiment of the invention, the at least one device is a hydraulic pump. Such a pump may be used advantageously for driving a lifting unit, in particular for lifting an implement or a trailer, in order to couple it to the vehicle.
[0011] According to another embodiment, the at least one device is a power take-off shaft. In field operation, such a shaft is conventionally used for driving an implement carried by the agricultural vehicle, and the power transmitted by it is a substantial fraction of the total power delivered by the internal combustion engine. However, in auxiliary operations such as coupling and uncoupling the implement, it may be necessary to rotate the power take-off shaft by a small angle in order to bring a terminal connector of the power take-off shaft into an orientation in which it can be coupled to a drive shaft of the tool. Obviously, this rotation requires only a minute fraction of the power the internal combustion engine could deliver, and energy is saved by leaving the internal combustion engine switched off in such a situation and using the electric machine as a motor to drive the power take-off shaft.
[0012] Evidently, the above-identified embodiments are combinable by associating two or more devices selected among an air conditioning unit, a hydraulic pump and a power take-off shaft to a second section of the powertrain.
[0013] Preferably, the powertrain further comprises a second clutch which delimits first and second subsections of said second section, where the first clutch and the electric machine are associated to the first subsection and the at least one device is associated to the second subsection. In this way, the electric machine is connected to the internal combustion engine, in particular for operation as a motor that assists the internal combustion engine in driving the powertrain, while the second subsection and the device associated to it are idle.
[0014] One of the devices drivable by the powertrain should be a wheel shaft. Since vehicle locomotion usually requires a substantial portion of the power of the internal combustion engine, the wheel shaft is preferably associated to the first section. In this way, the wheel shaft is driveable by the internal combustion engine regardless of whether the first clutch is open or closed.
[0015] Preferably, the electric machine is also operable as a generator driven by the powertrain, so that at a given time the electric machine generates the electric energy that will be needed for its operation later on.
[0016] In order to minimize the impact of electric power generation on the load of the internal combustion engine, a controller is provided for operating the electric machine as a generator, whenever the vehicle is in a brake mode. The brake mode may involve operation of friction brakes or an engine brake mode. In either case, the electric machine will have a decelerating effect that contributes to the braking action and converts into electric energy part of the kinetic energy of the vehicle that would otherwise be lost.
[0017] Further, an electric power outlet is provided that is powered by the electric machine. The electric power outlet can be used for operating electric appliances of various types.
[0018] The invention also provides a method of operating an agricultural vehicle as described above. The method includes driving an electric generator (which, preferably but not necessarily in the above-described electric machine) by means of the internal combustion engine, storing electrical energy from said generator in a battery and driving said at least one device using the electric machine while the internal combustion engine is off.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Further features and advantages of the invention will become apparent from the description of embodiments that follows, with reference to the attached figures, wherein:
[0020] FIG. 1 is a block diagram of a tractor according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] The following is a detailed description of example embodiments of the invention depicted in the accompanying drawings. The example embodiments are presented in such detail as to clearly communicate the invention and are designed to make such embodiments obvious to a person of ordinary skill in the art. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present invention, as defined by the appended claims.
[0022] The tractor of FIG. 1 comprises an internal combustion engine 1 , a gearbox 2 connected to the internal combustion engine by a drive shaft 3 , and wheel shafts 4 with wheels 5 , at least one of which wheel shafts 4 is driven via gearbox 2 and a differential gear 6 .
[0023] The drive shaft 3 extends straight through gearbox 2 to a primary member of a first friction clutch 7 . A secondary member of clutch 7 is mounted at the end of a secondary shaft 8 which carries a gearwheel 9 and extends through a second gearbox 10 . The second gearbox 10 is depicted in an idle state. By displacing a dog clutch 11 of the second gearbox 10 to the left or right along shaft 8 , one of gearwheels 12 , 13 is locked to the secondary shaft 8 , so as to drive a power take-off shaft 14 at a first or second transmission ratio.
[0024] The gearwheel 9 is engaged with two other gearwheels 15 , 16 . Gearwheel 15 drives a hydraulic lubricant pump 17 through a shaft 18 . There is no clutch between the secondary shaft 8 and the shaft 18 , so that whenever the secondary shaft 8 rotates, the pump 17 is driven. By means of a hydraulic valve, not shown, at the output of pump 17 , the output pressure of pump 17 can be switched between a low level, appropriate for feeding lubricant to bearings of the tractor, and a high level, appropriate for driving hydraulic pistons of a lifting device. Such a lifting device, for example, may comprise a three point hitch or three point linkage, which is conventionally used for attaching a plough, a harrow, a counterweight or other implements to rear and/or front ends of a tractor.
[0025] The gearwheel 16 drives a gearwheel 19 mounted on a layshaft 20 , along with an electric machine 21 . A belt drive 28 and a second friction clutch 22 connect layshaft 20 to a compressor 23 of an air conditioning unit which controls the temperature in a driver cabin of the tractor.
[0026] An electric converter 24 is connected between the electric machine 21 and a battery 25 . The electric machine 21 is operable as a motor, powered by electric energy from the battery 25 , or as a generator charging the battery 25 , depending on the mode of operation of the converter 24 .
[0027] When the electric machine 21 is in generator mode, the electric energy provided by it can be made available to electric appliances of various types by an electric power outlet, not shown, e.g., of the type conventionally used in buildings for two- or three-phase AC electric power. Such a power outlet may be provided in particular inside or close to the driver cabin, so as to enable, e.g., operation of a vacuum cleaner within the driver cabin. Further, a power outlet can advantageously be provided at a rear or the side of the tractor body, in order to provide electric power to an implement coupled to the tractor.
[0028] If the power outlet is directly connected to the electric machine 21 , in parallel to converter 24 , it may be useful to provide a generator operating mode for internal combustion engine 1 , in which its speed is controlled so that 50 Hz or 60 Hz AC power is directly output by electric machine 21 . Else, a second converter may be needed, so that electric power from electric machine 21 is first converted into DC by converter 24 , and then into 50 Hz or 60 Hz AC by the second converter. Of course, alternatively, DC power from converter 24 might be supplied to the power outlet.
[0029] While the tractor is not moving, the internal combustion engine 1 may be switched off, and clutch 7 is open. Electric machine 21 then functions as a motor which drives the compressor 23 , keeping the driver cabin cool while the driver has to wait for some other machine to finish its job on the field he is going to work on.
[0030] While the electric machine 21 is working as a motor, the input shaft 18 of the hydraulic pump 17 is rotating, too. But as long as the output pressure of pump 17 is at the low level, the load imposed on electric machine 21 by pump 18 is small. On the other hand, if the output pressure is set at the high level, the electric machine 21 can be used for powering the three-point hitch.
[0031] Further, by momentarily displacing dog clutch 11 from its idle position, power take-off shaft 13 can be rotated, so that a drive shaft of some implement coupled to the hitch can be brought into locking fit with a terminal connector 26 at the distal end of PTO shaft 13 . In this way, any preparations for field operation of the tractor that do not require the driving power of combustion engine 1 can be carried out efficiently while combustion engine 1 is off.
[0032] In field operation, when combustion engine 1 is working, electric machine 21 works as a motor or as a generator, depending on the circumstances. Whenever the power demand of the wheel shaft 4 or of an implement connected to power take-off shaft 13 rises strongly, electric machine 21 can be temporarily operated as a motor, in order to avoid fast and energy-inefficient load transitions of combustion engine 1 .
[0033] The electric machine 21 is operated as a generator whenever controller 27 detects a deficient charging state of battery 25 . Further, regardless of the charging state of the battery, electric machine 21 should work as generator whenever controller 27 detects that the driver is pressing a brake pedal or combustion engine 1 is running in brake mode.
[0034] The following list of reference signs of various elements mentioned above is included (as follows), for ease of explanation:
REFERENCE NUMERALS
[0000]
1 internal combustion engine
2 gearbox
3 drive shaft
4 wheel shaft
5 wheel
6 differential gear
7 clutch
8 second shaft
9 gearwheel
10 second gearbox
11 dog clutch
12 gearwheel
13 gearwheel
14 PTO shaft
15 gearwheel
16 gearwheel
17 hydraulic pump
18 shaft
19 gearwheel
20 layshaft
21 electric machine
22 clutch
23 compressor
24 converter
25 battery
26 terminal connector
27 controller
28 belt
[0063] As will be evident to persons skilled in the art, the foregoing detailed description and figures are presented as examples of the invention, and that variations are contemplated that do not depart from the fair scope of the teachings and descriptions set forth in this disclosure. The foregoing is not intended to limit what has been invented, except to the extent that the following claims so limit that. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/269,734, filed Nov. 12, 2008, (now issued as U.S. Pat. No. 7,810,751 to Caamano et al.) which is a continuation of U.S. patent application Ser. No. 11/420,164, filed May 24, 2006 (now issued as U.S. Pat. No. 7,533,843 to Caamaño et al.), which claims the benefit of U.S. Provisional Patent Application No. 60/685,637 filed May 27, 2005, and U.S. Provisional Patent Application No. 60/772,455 filed Feb. 10, 2006. The entire contents of all four of said priority applications (to which the present application claims priority) are incorporated herein by reference and should be considered a part of this specification.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to reels for spooling linear material and, in particular, to a reel including an improved reciprocating mechanism for distributing linear material across a rotating reel drum.
2. Description of the Related Art
Reels for spooling linear material, such as a hose or wire, onto a rotating drum have incorporated reciprocating motion of a guide through which the linear material passes, to advantageously cause the linear material to be wrapped substantially uniformly around most of the surface area of the drum.
Several methods have been utilized in the past for achieving such reciprocating motion. One common approach is to use a rotating reversing screw which causes a guide to translate back and forth in front of a rotating drum. For example, such an approach is shown in U.S. Pat. No. 2,494,003 to Russ. However, such reversing screws tend to wear out quickly, degrading reel performance and necessitating frequent replacement. Further, such reversing screws are bulky and increase the size of the reel assembly.
Another approach for producing reciprocating motion of the guide is to use a motor to control a rotating screw upon which the guide translates. In this class of reels, the motor reverses the direction of rotation of the screw whenever the guide reaches an end of the screw. Unfortunately, the repeated reversing of the motor increases the spooling time and causes the motor to wear down sooner. Other reels have incorporated significantly more complicated gear mechanisms for achieving the reciprocating motion.
Many reel constructions include exposed moving parts, such as the reel drum, guide, and motor. Over time, such moving parts can become damaged due to exposure. For example, an outdoor reel is exposed to sunlight and rain. Such exposure can cause the moving parts of the reel to wear more rapidly, resulting in reduced performance quality.
Thus, there is a need for a compact reel assembly having a reel with an improved reciprocating mechanism for efficiently distributing linear material across the reel drum.
SUMMARY OF THE INVENTION
Accordingly, it is a principle object and advantage of the present invention to overcome some or all of these limitations and to provide an improved reel incorporating a reciprocating mechanism.
In accordance with one embodiment, a reciprocating mechanism is provided, comprising an element adapted to rotate about a first axis and a worm gear extending along the first axis and coupled with respect to the element. The reciprocating mechanism also comprises a driven gear meshingly engaged with the worm gear, the driven gear configured to rotate about a driven gear axis. A lever is coupled to and configured to rotate along with the driven gear about the driven gear axis, the lever having an elongated slot. A guide member defines an encircling slot in a plane generally parallel to a plane within which the lever rotates. An elongate member has a portion extending completely or partially through, and adapted to move along, the elongated slot of the lever, the elongate member portion also extending completely or partially through, and adapted to move along, the encircling slot of the guide member. The elongate member is pivotably secured to a frame or housing such that the elongate member is configured to pivot about an axis generally perpendicular to the plane of the encircling slot. Rotation of the element about the first axis produces rotation of the worm gear about the first axis, the rotation of the worm gear producing rotation of the driven gear and the lever about the driven gear axis, the rotation of the lever guiding the portion of the elongate member along the encircling slot in order to reciprocatingly pivot the element relative to the frame or housing about a second axis generally transverse to the first axis.
In accordance with another embodiment, a reel assembly is provided. The reel assembly comprises a drum configured to rotate about a drum axis and to receive a linear material being wrapped around a spool surface of the drum as the drum rotates about the drum axis and a housing substantially enclosing the drum, a portion of the housing defining an aperture configured to receive the linear material therethrough. The reel assembly also comprises a reciprocating mechanism, comprising a lever operatively coupled with respect to the drum and defining an elongated slot. A guide member is disposed proximal the lever, the guide member defining an encircling slot. An elongate member has a portion extending completely or partially through the elongated slot of the lever and extending completely or partially through the encircling slot of the guide member, the elongate member being pivotably coupled with respect to the housing. The rotation of the drum about the drum axis rotates the lever, which in turn guides the elongate member portion along the encircling slot so as to reciprocatingly rotate the drum relative to the housing about a reciprocation axis generally transverse with respect to the drum axis.
In accordance with another embodiment, a reel assembly is provided, comprising a drum configured to rotate about a drum axis and to receive a linear material being wrapped around a spool surface of the drum as the drum rotates about the drum axis and a housing substantially enclosing the drum, a portion of the housing defining an aperture configured to receive the linear material therethrough. The reel assembly also comprises a reciprocating mechanism configured to produce relative reciprocating rotation between the drum and the housing about an axis generally orthogonal to the drum axis and at a generally constant angular velocity between endpoints of the reciprocation for a given drum rotating speed about the drum axis.
In accordance with still another embodiment, a method for spooling linear material is provided. The method comprises rotating a drum about a first axis at a first speed, reciprocatingly rotating the drum about a second axis generally perpendicular to the first axis at a generally constant second speed between endpoints of the reciprocation, and drawing linear material onto the drum, the linear material being spooled across a surface of the drum by the reciprocating rotation of the drum.
For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described herein above. Of course, it is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
All of these aspects are intended to be within the scope of the invention herein disclosed. These and other aspects of the present invention will become readily apparent to those skilled in the art from the appended claims and from the following detailed description of the preferred embodiments having reference to the attached figures, the invention not being limited to any particular preferred embodiment(s) disclosed.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features, aspects and advantages of the present invention will now be described in connection with a preferred embodiment of the invention, in reference to the accompanying drawings. The illustrated embodiment, however, is merely an example and is not intended to limit the invention. The drawings include the following figures.
FIG. 1 is a front perspective view of a disassembled reel, including a housing, in accordance with one embodiment.
FIG. 2 is a bottom perspective view of a drum assembly with reciprocating mechanism, in accordance with one embodiment disclosed herein.
FIG. 2A is a schematic illustration of a gear reduction between a motor and a gear of the reciprocating mechanism shown in FIG. 2 .
FIG. 3 is a top and side perspective view of one embodiment of a drum assembly.
FIG. 4 is bottom and side perspective view of the drum assembly in FIG. 3 .
FIG. 5 is a top partially cut-away perspective view of the reciprocating mechanism shown in FIG. 2 .
FIG. 6 is a bottom partially cut-away view of the reciprocating mechanism for a reel shown in FIG. 2 .
FIG. 7 is a bottom and side partially cut-away perspective view of reciprocating mechanism of FIG. 2 .
FIG. 8A is a top view of the drum assembly of FIG. 2 illustrating one position in the reciprocating rotation of the drum.
FIG. 8B is a top view of the drum assembly of FIG. 2 illustrating another position in the reciprocating rotation of the drum.
FIG. 8C is a top view of the drum assembly of FIG. 2 illustrating another position in the reciprocating rotation of the drum.
FIG. 8D is a top view of the drum assembly of FIG. 2 illustrating another position in the reciprocating rotation of the drum.
FIG. 8E is a top view of the drum assembly of FIG. 2 illustrating another position in the reciprocating rotation of the drum.
FIG. 9A is a top and front perspective view of the reel assembly of FIG. 1 illustrating one position in the reciprocating rotation of the drum.
FIG. 9B is a top and front perspective view of the reel assembly of FIG. 1 illustrating another position in the reciprocating rotation of the drum.
FIG. 10 is a top partially cut-away perspective view of another embodiment of a reciprocating mechanism.
For ease of illustration, some of the drawings do not show certain elements of the described apparatus.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the following detailed description, terms of orientation such as “top,” “bottom,” “upper,” “lower,” “front,” “rear,” and “end” are used herein to simplify the description of the context of the illustrated embodiments. Likewise, terms of sequence, such as “first” and “second,” are used to simplify the description of the illustrated embodiments. Because other orientations and sequences are possible, however, the present invention should not be limited to the illustrated orientation. Those skilled in the art will appreciate that other orientations of the various components described above are possible.
FIG. 1 illustrates one embodiment of a reel assembly 100 substantially enclosing a drum assembly 10 in a housing. In the illustrated embodiment, the housing includes an upper or top shell portion 22 and a lower or bottom shell portion 24 . Additionally, the upper and lower shell portions 22 , 24 have the shape of upper and lower domes 26 , 28 , respectively, so that the reel assembly 100 has a generally spherical shape. However, the upper and lower shell portions 22 , 24 can have any suitable shape, such as cylindrical and aspherical. As shown in FIG. 1 , the upper shell portion 22 includes a guide member 30 with an aperture (not shown), which preferably guides a linear material, such as a water hose, into and out of the housing of the reel assembly 100 as the linear material is wound onto or unwound from the drum assembly 10 . Additionally, the lower shell portion 24 is preferably supported by a plurality of legs 32 . However, other types of legs or support structures can be used. In one embodiment, a circumferential stand supports the lower shell portion 24 on a support surface. Preferably, the lower shell portion 24 is movably supported with respect to a lower support surface, so that the reel assembly 100 is capable of moving along the surface. For example, the legs 32 or support structure can have rollers.
As seen in FIGS. 1 and 2 , the drum assembly 10 defines a first or drum axis X about which the drum rotates. Additionally, a housing or second axis Y extends through the reel assembly 100 . In a preferred embodiment, the housing axis Y is generally vertical and the drum axis X is generally horizontal, so that the housing axis Y is generally orthogonal to the drum axis X. Further details on reel assemblies can be found in U.S. Pat. No. 6,279,848, the entire contents of which are hereby incorporated by reference and should be considered a part of this specification.
FIGS. 2-7 illustrate one embodiment of a reciprocating mechanism 200 for a reel assembly. In one embodiment, the reciprocating mechanism 200 can be used with the reel assembly 100 illustrated in FIG. 1 . The reciprocating mechanism 200 preferably includes a frame 210 comprising a top frame and a bottom frame. In the illustrated embodiment, the top frame includes an upper ring 212 and the bottom frame includes a lower ring 214 (see FIG. 1 ). In a preferred embodiment, the upper ring 212 is coextensive with and removably disposed on the lower ring 214 . In another embodiment, the upper ring 212 overlaps the lower ring 214 . The upper and lower rings 212 , 214 are preferably fastened to the upper and lower shell portions 22 , 24 , respectively, via any suitable method. In one embodiment, the shell portions 22 , 24 can be fastened to the rings 212 , 214 , respectively, using bolts or screws. In another embodiment, the shell portions 22 , 24 can be clamped, welded, or adhesively secured to the rings 212 , 214 .
In a preferred embodiment, the upper ring 212 can rotate relative to the lower ring 214 . For example, bearings 213 , as shown in FIG. 1 , can be disposed between the upper and lower rings 212 , 214 . Preferably, the rings 212 , 214 are sized to enclose a drum assembly 220 , which consists of first and second endplates 222 , 224 and a drum 226 disposed between the endplates 222 , 224 . As shown in FIGS. 2 and 5 , a ring gear 230 is preferably attached to the first endplate 222 .
The ring gear 230 is coupled to a shaft 232 , which preferably extends into a hollow portion 228 of the drum 226 and rotatingly couples to a shaft support 234 disposed inside the hollow portion 228 (see FIG. 3 ). In one preferred embodiment, the shaft support 234 is disposed generally at the center of the upper ring 212 . In another embodiment, the shaft support 234 can be offset from the center of the upper ring 212 . Preferably, the shaft support 234 allows the shaft 232 to rotate freely therein. For example, in one embodiment, the shaft 232 can couple to the shaft support 234 via a bearing (not shown) disposed therein. As explained more fully below, the shaft 232 is preferably hollow so as to convey water. Additionally, the connection between the shaft 232 and the shaft support 234 preferably inhibits the leakage of fluid therebetween, as further discussed below. For example, in one embodiment, the connection between the shaft 232 and the shaft 234 includes a substantially water-tight seal.
The shaft 232 also connects to a fitting 236 . The fitting 236 couples to a conduit member 262 disposed within the lower shell portion 24 and disposed below the lower ring 214 . In the illustrated embodiment, the conduit member 262 is curved and has a first end 264 that connects to the fitting 236 , which in turn connects to the shaft 232 . The conduit member 262 has a second end 266 disposed generally along an axis Y 2 extending generally perpendicular to the upper and lower rings 212 , 214 . In one embodiment, the shell axis Y and the axis Y 2 are coaxial. Preferably, the second end 266 extends through an aperture (not shown) in the lower shell portion 24 . In one preferred embodiment, the fitting 236 is not coupled to the upper ring 212 . Further description of the fitting 236 and the conduit member 262 is provided below.
As shown in FIG. 5 , an upper ring support member 238 extends from a surface 240 of the upper ring 212 . In the illustrated embodiment, the upper ring support member 238 defines a slot 239 therein. Preferably, the slot 239 extends along the length of the support member 238 and is sized to slidingly receive one end 245 a of a support frame 245 coupled to the conduit member 262 . As shown in FIG. 5 , the support frame 245 has a horizontal portion and a vertical portion, and the end 245 a extends from the horizontal portion of the support frame 245 . In one embodiment, at least one bearing (not shown) is disposed in the slot 239 to facilitate the sliding of the end 245 a of the support frame 245 relative to the slot 239 . However, other suitable methods for facilitating the sliding of the support frame 245 in the slot 239 , such as, for example, applying a lubricant to at least one of the slot 239 and the end 245 a of the support frame 245 .
Preferably, the shaft 232 includes a worm gear section 242 , which extends along at least a portion of the shaft 232 . In one embodiment, the worm gear section 242 extends along substantially the entire length of the shaft 232 . The shaft 232 is preferably integrally formed with the worm gear section 242 . In another embodiment, the shaft 232 is removably coupled to the worm gear section 242 via, for example, a spline connection.
As shown in FIGS. 2 , 6 and 7 , the worm gear section 242 preferably meshingly engages a top or driven gear 244 mounted on and below the support frame 245 . As used herein, the “engagement” of two gears means that the teeth of one gear are engaged with the teeth of the other gear. The top gear 244 is in turn coupled to a lever 246 (see FIG. 5 ), for example, via a pin 246 a (see FIG. 8B ) that extends along an axis of rotation of the top gear 244 . As shown in FIG. 5 , the lever 246 defines an elongated slot 247 therein. In a preferred embodiment, the top gear 244 and lever 246 are lockingly coupled, so that rotation of the top gear 244 results in rotation of the lever 246 . In another embodiment, the top gear 244 and lever 246 are integrally formed. The lever 246 is preferably coupled to an elongate member 248 , so that a first end or portion 248 a of the elongate member 248 extends through and is adapted to slidingly move along the slot 247 , while a second end or portion 248 b of the elongate member 248 is pivotably secured to the support member 238 . In one embodiment, the first end 248 a of the elongate member 248 extends completely through the slot 247 of the lever 246 and at least partially or completely through the slot 252 of the guide member 250 (described below). In another embodiment, the lever 246 is below the guide member 250 , and the first end 248 a of the elongate member 248 extends completely through the slot 252 and at least partially or completely through the slot 247 of the lever 246 .
As best shown in FIG. 5 , a guide member or track 250 is disposed adjacent the lever 246 , so that the guide member 250 extends along a plane generally parallel to a plane within which the lever 246 rotates. In the illustrated embodiment, the guide member 250 defines an encircling slot 252 . In the illustrated embodiment, the encircling slot 252 extends only partially through the guide member 250 , so as to define a groove or recess. In another embodiment, the encircling slot 252 can extend completely through the guide member 250 . In the illustrated embodiment, the first end 248 a of the elongate member 248 extends partially through and is adapted to move along the encircling slot 252 of the guide member 250 , so that the elongate member 248 pivots about an axis generally perpendicular to the plane of the encircling slot 252 . In another embodiment, the first end 248 a of the elongate member 248 can extend completely through the encircling slot 252 of the guide member 150 . In the illustrated embodiment, the guide member 250 is disposed between the support frame 245 and the lever 246 and is preferably secured to the support frame 245 . However, in another embodiment, the lever 246 can be positioned between the support frame 245 and the guide member 250 . As used herein, encircling means surrounding, but is not necessarily limited to a circular surrounding. In the illustrated embodiment, the guide member 250 is shaped somewhat in the form of a “D” (see FIG. 8A ). However, the guide member 250 can have other suitable shapes, such as circular, oval, triangular and trapezoidal.
As shown, for example in FIG. 2 , the reciprocating mechanism 200 includes a motor 254 mounted to the support frame 245 . In the illustrated embodiment, the motor 254 is disposed below the lower ring 214 and is housed in the lower shell portion 24 . Preferably, the motor 254 is an electric motor. The motor 254 preferably operatively connects to the ring gear 230 via a drive gear 256 . For example, the motor 254 can, through a gear reduction comprising multiple gears, drive the drive gear 256 , which can operatively drive the ring gear 230 at a desired speed. One example of a gear reduction is shown in FIG. 2A , which includes a motor gear 254 a that meshingly engages and drives the drive gear 256 . In the illustrated embodiment, another gear 257 (also shown in FIG. 6 ), which is preferably co-axial with the drive gear 256 , meshingly engages and drives the ring gear 230 . However, the gear reduction can include any number of gears and have other configurations for operatively coupling the motor 254 to the ring gear 230 . Additionally, any desired gear ratio can be used. In one embodiment, the gear reduction has a gear ratio of 2 to 1. In another embodiment, the gear reduction has a gear ratio of 4 to 1. In still another embodiment, the gear reduction has a gear ratio of between about 2 to 1 and about 25 to 1. One example of a gear reduction between the motor 254 and the ring gear 230 is schematically shown in FIG. 2A .
The reel 100 can also employ an electronic motor controller and associated electronic componentry for controlling the speed and direction of the motor 254 . For example, while spooling the linear material 268 (see FIG. 9A ) onto the drum 226 , a motor-controller can be employed to vary the motor speed based upon the length of unwound linear material 268 . It will be appreciated that if the motor speed is constant, the inwardly pulled linear material 268 tends to move increasingly faster due to the increasing diameter of the spool itself. A motor-controller can adjust the motor speed to more safely control the motion of the linear material 268 during spooling. Also, a motor-controller can be used to slow or stop the motor 254 just before the linear material 268 becomes completely spooled onto the drum 226 . Otherwise, the linear material 268 would get pulled into the housing or, if there is an object at the end of the linear material 268 (e.g., a nozzle), the object may whip against or otherwise impact the housing or a person near the housing. In addition, a motor-controller can even be used to assist the user during unspooling of the linear material 268 (i.e., powered unspooling). One example of a motor-controller for a reel is disclosed in U.S. Pat. No. 7,350,736 to Caamaño et al., entitled Systems and Methods for Controlling Spooling of Linear Material, the entire contents of which are hereby incorporated by reference and should be considered a part of this specification. Also, the motor 254 and/or motor-controller can be operated via a remote control. An exemplary remote control system for a motorized reel is disclosed in U.S. Pat. No. 7,503,338 to Harrington et al., the entire contents of which are hereby incorporated by reference and should be considered a part of this specification. In a preferred embodiment, a remote control is engaged on the spooled linear material 268 at or near its outward end. The remote control can send signals wirelessly (e.g., via radio frequency signals) or through a wire within the linear material.
As shown in FIGS. 3-4 , the reciprocating mechanism 200 also has a platform 258 that extends between the shaft support 234 and the edge of the upper ring 212 . As shown in FIG. 8A , the platform 258 is disposed generally opposite the upper ring support member 238 . The platform 258 preferably extends into the hollow portion 228 of the drum 226 . In one embodiment, the platform 258 can support a battery 259 , as shown in FIG. 3 , thereon so that the battery 259 is disposed between the second endplate 224 and the upper ring 212 . Preferably, the battery 259 provides power to the motor 254 . Details of one suitable battery for use with the reciprocating mechanism 200 can be found in U.S. Pat. No. 7,320,843 to Harrington, entitled Battery Assembly With Shielded Terminals, the entire contents of which are hereby incorporated by reference and should be considered a part of this specification.
As shown in FIGS. 3 and 4 , the platform 258 preferably supports the shaft support 234 thereon. In the illustrated embodiment, a pin 234 a of the shaft support 234 pivotably extends through an opening 258 a of the platform 258 , permitting the shaft support 234 to rotate with respect to the platform 258 about a vertical axis extending through the opening 258 a . This pivot connection advantageously allows the reciprocating mechanism 200 to reciprocatingly rotate the drum 226 about the shell axis Y, as further discussed below.
As discussed above, the fitting 236 couples to the conduit member 262 . In one embodiment, the second end 266 of the conduit 262 is configured to removably attach to a water hose (not shown). For example, the second end 266 can have a threaded surface for threaded engagement with a corresponding thread on the hose (e.g., a standard hose fitting). In another embodiment, the second end 266 can have a quick-disconnect portion configured to removably engage a corresponding quick-disconnect portion on the hose. Other mechanisms for connecting the hose and the conduit 262 are also possible. Preferably, water provided through the hose flows through the conduit 262 and through the fitting 236 and shaft 232 into the shaft support 234 . In one preferred embodiment, the shaft support 234 communicates, for example, via a second conduit (not shown), with a second fitting 268 (see FIGS. 2 and 8A ) disposed on the surface of the drum 226 . In this manner, water can be supplied to a hose that has been spooled on the drum 226 and has been removably fastened to the second fitting 268 . Any suitable mechanism for removably fastening the hose and the second fitting 268 can be used, such as a threaded engagement or a quick-disconnect connection. Further details on such an arrangement is shown, for example, in U.S. Pat. No. 6,981,670 to Harrington, entitled Reel Having Apparatus for Improved Connection of Linear Material, the entire contents of which are hereby incorporated by reference and should be considered a part of this specification.
The rings 212 , 214 and gears 230 , 242 , 244 , 256 of the reciprocating mechanism 200 are preferably made of a strong material resistant to breaking. In one embodiment, the rings 212 , 214 and gears, 230 , 242 , 244 , 256 can be made of a metal or metal alloy, such as stainless steel and aluminum. However, other materials can also be used. In another embodiment, the rings 212 , 214 and gears 230 , 242 , 244 , 256 of the reciprocating mechanism 200 can be made of a hard plastic. In still another embodiment, the gears 230 , 242 , 244 , 256 may be formed of acetyl, such as Delrin® sold by Dupont, headquartered in Wilmington, Del. Various combinations of these materials are also possible.
The use of the reciprocating mechanism 200 to reciprocatingly rotate the drum assembly 220 is illustrated in FIGS. 8A-8E . Actuation of the motor 254 preferably rotates the ring gear 230 in one direction via the drive gear 256 and, optionally, a gear reduction assembly (see e.g., FIG. 2A ) operatingly coupling the motor 254 to the drive gear 256 . Rotation of the ring gear 230 in turn rotates the reel drum 226 via the first endplate 222 . Rotation of the ring gear 230 also rotates the shaft 232 in the same direction, causing the worm gear section 242 to also rotate. Rotation of the worm gear section 242 rotates the top or driven gear 244 , which in turn rotates the lever 246 about the axis of the top gear 244 . As the lever 246 rotates, it guides the first end 248 a of the elongate member 248 about the axis of the top gear 244 and along the encircling slot 252 of the guide member 250 , thus moving the elongate member back and forth. As the lever 246 rotates and guides the first end 248 a of the elongate member 248 about the axis of the top gear 244 , the first end 248 a also slides along the slot 247 of the lever 246 . The movement of the elongate member 248 in turn reciprocatingly rotates the drum 226 relative to the upper ring 212 about the shell axis Y via the pivot connection 234 a , 258 a between the shaft support 234 and the platform 258 . In one embodiment (e.g., if the slot 252 is circular), the reciprocating mechanism 200 reciprocatingly rotates the drum 226 so that an angular velocity of the drum about the shell axis Y fluctuates generally sinusoidally.
In a preferred embodiment, the slot 247 on the lever 246 and the encircling slot 252 on the guide member 250 allow the drum 226 to reciprocate about the shell axis Y at a generally constant angular velocity between endpoints of the reciprocation for a given drum 226 rotation speed about the drum axis X. It is the general D-shape of the slot 252 that produces this outcome. It will be appreciated that other sizes and shapes of the slot 252 , slot 247 , lever 246 , and elongate member 248 can achieve the goal of a generally constant angular velocity between endpoints of the reciprocation.
In one embodiment, the upper shell portion 22 , which is preferably fixed with respect to the upper ring 212 , and the aperture guide 30 in the upper shell portion 22 , remain in a fixed position while the drum 226 reciprocatingly rotates inside the housing to spool and unspool the linear material 268 , as shown in FIGS. 9A-9B . In another embodiment, the reciprocating mechanism 200 reciprocatingly rotates the upper shell portion 22 about the shell axis Y, while the drum 226 is preferably in a substantially fixed angular position.
The substantially constant angular velocity of the drum 226 about the shell axis Y that is generated by the reciprocating mechanism 200 advantageously allows the spooling and unspooling of linear material onto the drum 226 with increased efficiency. Such increased efficiency allows the use of a drum 226 having a smaller width to spool the same amount of linear material, requires less power to spool the same amount of linear material, and allows for an overall reduction in the size of the reel assembly 100 . The reciprocating mechanism 200 according the embodiments discussed above also advantageously require about 30% less parts to operate than conventional reciprocating mechanisms.
FIG. 10 illustrates another embodiment of a reciprocating mechanism 200 ′. The reciprocating mechanism 200 ′ is similar to the reciprocating mechanism 200 , except as noted below. Thus, the reference numerals used to designate the various components of the reciprocating mechanism 200 ′ are identical to those used for identifying the corresponding components of the reciprocating mechanism 200 in FIG. 5 , except that a “′” has been added to the reference numerals.
The reciprocating mechanism 200 ′ includes a top or driven gear coupled to a lever 246 ′ via a pin 246 a ′ that extends along the axis of the top gear. The top gear and the lever 246 ′ are preferably lockingly coupled, so that rotation of the top gear about the top gear axis results in rotation of the lever 246 ′ in the same direction. In another embodiment, the top gear and the lever 246 ′ can be integrally formed. The lever 246 ′ is preferably pivotably coupled to an elongate member 248 ′ at a first pivot point 248 a ′. The elongate member 248 ′ is also pivotably secured to a support member 238 ′ at a second pivot point 248 b ′. The relative motion between the lever 246 ′ and the elongate member 248 ′ advantageously generates a reciprocating motion of the drum 226 ′ about a drum axis.
In a preferred embodiment, the gear ratio of the gear reduction and size of the ring gear 230 , worm gear 242 , drive gear 256 , and top gear 244 , as well as the lengths of the levers 246 and elongate member 248 , are selected to reciprocatingly rotate the drum 226 relative to the upper ring 212 about the shell axis Y so as to cause a linear material to be generally uniformly wound onto the reel drum. Thus, the reciprocating mechanism 200 advantageously allows a linear material to be uniformly wound onto the drum 226 .
As discussed above, the upper ring 212 and drum assembly 220 preferably rotate freely relative to the lower ring 214 , preferably through 360 degrees and more, as desired. Therefore, the upper shell portion 22 coupled to the upper ring 212 can advantageously rotate freely relative to the lower shell portion 24 , which is preferably fixed with respect to the lower ring 214 .
Of course, the foregoing description is that of certain features, aspects and advantages of the present invention, to which various changes and modifications can be made without departing from the spirit and scope of the present invention. Moreover, the reciprocating mechanism for a reel assembly need not feature all of the objects, advantages, features and aspects discussed above. Thus, for example, those skill in the art will recognize that the invention can be embodied or carried out in a manner that achieves or optimizes one advantage or a group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein. In addition, while a number of variations of the invention have been shown and described in detail, other modifications and methods of use, which are within the scope of this invention, will be readily apparent to those of skill in the art based upon this disclosure. It is contemplated that various combinations or subcombinations of these specific features and aspects of embodiments may be made and still fall within the scope of the invention. Accordingly, it should be understood that various features and aspects of the disclosed embodiments can be combined with or substituted for one another in order to form varying modes of the discussed reciprocating mechanism for a reel assembly. | 4y
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This is a continuation-in-part of copending application(s) Ser. No. 07/116,016 filed on Oct. 30, 1987, 4,836,221.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device for controlling the content of tobacco on a cigarette manufacturing machine and, more particularly, to a tobacco content control device which is capable of controlling the tobacco content constantly to a predetermined amount, so as to guarantee production of cigarettes having uniform tobacco contents.
2. Description of the Related Art
The reduction of total operating costs is a matter of the utmost importance to cigarette manufacturers, as this is a major factor in improving their profitability. Therefore, extensive studies have been carried out with a view to reducing operating costs as much as possible.
One way of reducing operating costs is to enhance the productivity of the cigarette manufacturing machines. From this viewpoint, technical developments have almost reached the point where a single cigarette manufacturing machine can now produce as many as 8,000 cigarettes per minute.
Another way of reducing operating costs is to reduce the weight of the tobacco content of the individual cigarettes. When recent increases in the price of leaf tobacco are taken into consideration, the above approach can yield vast profits through a slight reduction of the tobacco content of each cigarette. However, unduly large reductions of the tobacco content make it difficult to maintain the required quality. Thus, the approach most widely adapted by cigarette manufacturers has been to reduce irregularities in the weight of the tobacco content of individual cigarettes, thereby decreasing the total amount of tobacco used in cigarette production.
More specifically, in the manufacture of cigarettes as currently carried out, the weight of the tobacco content of the cigarettes and a standard deviation corresponding to irregularities in the measured weight are measured. The standard deviation is added to the minimum allowable weight, to obtain the weight which indicates the minimum acceptable quality, i.e., the target value. The cigarettes are then manufactured on the basis of this target value. Therefore, by reducing irregularities in the tobacco content of the individual cigarettes, the target value in production, i.e., the total weight of tobacco used in cigarette production is necessarily reduced.
In order to reduce irregularities in the tobacco content, it is important to maintain the cigarette manufacturing machines in good operating condition, so as to preclude unintended movement of worn-out mechanical parts. However, the most effective measure, in this regard, is to add a tobacco content control device of high quality to the cigarette manufacturing machine. Accordingly, various conventional devices have been proposed in this connection.
For example, Japanese Patent Publication No. 40-14560 (U.S. Pat. No. 3,288,147) discloses a method of controlling the tobacco content on the basis of air permeability, utilizing the correlation between the weight of the tobacco content and their air permeability. However, this method is adversely affected by variations in the suction pressure, particle size, and composition of the tobacco. These variations tend to disturb the pre-established correlation between the weight and air permeability of the tobacco content. Therefore this method has failed to reduce irregularities in the tobacco content to any significant degree.
U.S. Pat. Nos. 2,937,280 and 2,861,683 disclose methods of controlling the tobacco content on the basis of electrostatic capacitance, utilizing the correlation between the tobacco content and their electrostatic capacitance. These methods are, however, susceptible to the influences of the moisture content of the tobacco and temperature, which bias the correlation between the tobacco content and their electrostatic capacitance. Accordingly, these methods do not contribute to the reduction of irregularities in the tobacco content to any substantial degree, and have almost no practical application.
Still another method of reducing irregularities in the weight of the tobacco content utilizes the correlation between the transmission factor of radiation rays, especially β rays emitted from strontium 90, and the density of the tobacco. The tobacco content is controlled on the basis of the transmission factor of these rays. This method is, however subject to such problems as safety in handling the radiation rays, drifting and the inferior response of an amplifier in a subsequent stage, due to the weakness of the output current of an ionization box which serves as a radiation ray detector. However, since there is a reliable correlation between the transmission factor of radiation rays and the tobacco content, this method is employed in most current cigarette manufacturing machines.
There are many causes for irregularities in the tobacco content of cigarettes, such as eccentricity of a cut tobacco feed drum, slippage of cut tobacco during its suction into a perforated cigarette belt, cluttering of a trimmer, nonuniform wear of a wall for stacking cut tobacco, and slippage during production of cigarettes. For this reason, according to frequency analysis of variations in signals corresponding to densities of stick-like cigarettes, various frequencies, from a low frequency of 0.001 Hz (long variation cycle) to a high frequency of 10 Hz or 100 Hz (short variation cycle), are continuously included, and thus a so-called "white noise" state results therefrom.
In order to reduce irregularities in the tobacco content of cigarettes, a fast response control device may be used to eliminate variations in density signals representing speeds lower than the response speed.
In the 1950s, a tobacco content control device utilizing a radiometric density detector was proposed for the above purpose. Extensive studies have been carried out since then, to improve the response speed of the device.
A device for controlling the tobacco content of cigarettes by utilizing radiation rays is described in U.S. Pat. No. 2,954,775. This device employs a method of controlling the feed speed of a cut tobacco feeder on the basis of a signal from the radiometric density detector. According to this method, however, the speed of a feeder having a large inertia must be controlled. Consequently, the response rate cannot be increased to a specific or higher value. As a result, the only weight variations eliminated using this device, are those corresponding to a low frequency of about 0.01 Hz or less.
In order to increase the response speed, Japanese Patent Publication No. 38-15949 (U.S. Pat. No. 3,089,497) proposes a method of controlling a transferred tobacco layer on the basis of a signal from a radiometric density detector. According to this method, a drive motor is rotated in the forward/reverse direction to move the trimmer, in order to control the amount of tobacco. The trimmer presents a relatively small inertia when it is moved. In addition, the time interval (i.e., the delay time) from weight change detection by the radiation ray detector to the driving of the trimmer is relatively short. For these reasons, a response speed higher than is attainable by use of other methods can be obtained, in this case, with variations in frequencies of 0.1 Hz or less being almost entirely eliminated. Consequently, this method is employed in most current cigarette manufacturing machines.
Japanese Patent Publication No. 51-95198 (U.S. Pat. No. 4,036,238) proposes a method of utilizing an electrohydraulic servo mechanism for moving the trimmer up and down, instead of the motor for driving the trimmer which is disclosed in the above-described method. According to the improved method, weight variation corresponding to a low frequency of about 0.5 Hz or less can be eliminated.
U.S. Patent Application Serial No. 705,877, filed Feb. 27, 1985 (corresponding to Japanese Patent Disclosure (Kokai) No. 60-234574 and EPC Laid Open Publication No. 160,799) proposes a method of minimizing the delay time by arranging another radiometric density detector immediately behind the trimmer. This method permits the elimination of variations in frequencies of 1 Hz or less.
However, development of these high-speed devices has, instead of satisfying demand, merely created further, strong demand for the development of a tobacco content control device of even higher speed and higher performance.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a high-performance tobacco content control device for a cigarette manufacturing machine, which can control a tobacco content with high accuracy and in which variations in frequencies of 10 Hz or less ar almost eliminated.
The tobacco content control device of the present invention is used in a cigarette manufacturing machine wherein the tobacco content is fed by means of an air-permeable conveyor band, and after trimmed by a trimming means, the tobacco content on the conveyor band is wrapped by a wrapping means, thereby producing stick-like cigarettes.
The tobacco content control device comprises: a first radiometric density detector for detecting the density of the tobacco content before the tobacco content is trimmed; a second radiometric density detector, located downstream of the wrapping means, for detecting the density of the cigarettes; a high pass filter for picking up only high-frequency components out of a first signal supplied from the first radiometric density detector; a feed forward control circuit, including a delay circuit which delays the high-frequency components by a predetermined time, for generating a feed forward control signal corresponding to an instantaneous variation in the first signal; a feed back control circuit, including an integrator which integrates a second signal supplied from the second radiometric density detector, for generating a feed back control signal corresponding to an average variation in the second signal; and an adder for adding the feed forward control signal and the feed back control signal together, an output of the adder being used for controlling the trimming means, thereby controlling the amount of tobacco content fed to the cigarette manufacturing machine.
With the above construction, the feature of the feed back control performed by the second radiometric density detector and the feature of the feed forward control performed by the first radiometric density detector are advantageously combined together. As a result of this combination, the present invention provides a control system capable of quickly responding to a detection signal. It should be also noted that the delay circuit is provided for the feed forward control circuit. Therefore, the transfer time, which corresponds to the time interval between the density detection performed by the first radiometric density detector and the trimming, can be compensated for in consideration of both mechanical and electrical delays of the control system. As a result, the tobacco content can be controlled with accuracy.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a cigarette manufacturing machine comprising a tobacco content control device according to an embodiment of the present invention;
FIG. 2 is a sectional view of a first radiometric density detector shown in FIG. 1;
FIG. 3 is a sectional view showing a second radiometric density detector shown in FIG. 1;
FIG. 4 is a circuit diagram of the tobacco content control device of the present invention;
FIG. 5 is a circuit diagram showing an example of the construction of the delay circuit shown in FIG. 4; and
FIG. 6 is a perspective view of a hydraulic servo valve serving as a component of the tobacco content control device.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a cigarette manufacturing machine comprising tobacco content control devices according to an embodiment of the present invention. In the cigarette manufacturing machine shown in FIG. 1, cut tobacco is sucked upward through chimney 100 and adhered by suction to the lower side of perforated cigarette conveyor 103 which is located beneath suction chamber 102. The adhered tobacco layer is transferred to the left in the drawing toward trimmer 104. The density of the tobacco layer is measured by first radiometric density detector 106 located in the upstream side of trimmer 104. The thickness of the cut tobacco layer is adjusted to a proper thickness by trimmer 104. The cut tobacco layer having the proper thickness is transferred onto and rolled in cigarette paper which is fed from paper roll 108 and stacked on cloth tape 110. The cigarette paper is glued by glue applicator 112 and the glued portions are dried by heater 114 to form a stick-like cigarette. The thus formed stick-like cigarette is transferred to the left and passed through second radiometric density detector 116 to check its density and to cut the cigarettes into the required length with cutter 118. The cigarettes from cutter 118 are transferred to a tray by a conveyor (not shown).
FIG. 2 shows the construction of first radiometric density detector 106. Detector 106 mainly comprises radiation source 106a which emits radiant rays, and ionization box 106b which receives the radiant ray from radiation source 106a. Radiation source 106a and ionization box 106b are spaced apart from each other by a predetermined distance. Aperture windows 106c and 106d are located between ionization box 106b and radiation source 106a and serve as a radiation path. Aperture windows 106c and 106d oppose each other and are spaced apart from each other by a predetermined distance. Metal films 106e and 106f, preferably consisting of titanium foils, are adhered to aperture windows 106c and 106d, respectively. A channel for passing trimmed tobacco T on perforated conveyor 103 is provided between thin metal films 106e and 106f. Shutter 106g is provided between radiation source 106a and aperture window 106c to prevent leakage of radiation.
The operation of first radiometric density detector 106 will be described below.
When shutter 106g is open, the radiant rays emitted from radiation source 106a is transmitted through thin metal film 106e of aperture window 106c and is incident on trimmed tobacco T. The radiation rays are transmitted through trimmed tobacco T in accordance with the density of tobacco T and are incident on ionization box 106b through metal film 106f of aperture window 106d. The outer periphery of ionization box 106b is maintained at a high potential by high voltage power supply 106h, so that an ionization current corresponding to the measured density of trimmed tobacco T is generated, and this current is supplied to amplifier 106i.
A trimmer (not shown) is controlled and driven by this signal current. A detection output from first radiometric density detector 106 represents a density signal representing the density of the tobacco layer prior to formation of cigarettes.
FIG. 3 shows the construction of second radiometric density detector 116.
Detector 116 is similar to that which is used on known cigarette manufacturing machines as described above and mainly comprises radiation source 116a and ionization box 116b which oppose each other and are spaced apart from each other by a predetermined distance. Stick-like cigarette S is located between radiation source 116a and ionization box 116b. Shutter 116c for shielding radiation rays are provided between radiation source 116a and stick-like cigarette S. In addition to radiation source 116a and ionization box 116b which are used to detect the density of stick-like cigarette S, detector 116 also includes reference object 116e, radiation source 116d, and ionization box 116f, which are used to provide a target value of the cigarette density. Radiation source 116d and ionization box 116f oppose each other through reference object 116e. Ionization box 116f detects the density of reference object 116e and is electrically connected through lead wires to ionization box 116b for detecting the cigarette density.
The operation of the second radiometric density detector will be described below.
Radiation rays emitted from detector 116 are incident on stick-like cigarette S and is transmitted therethrough according to the cigarette density. The transmitted rays are incident on ionization box 116b. A negative voltage is applied by high voltage power supply to the outer periphery of ionization box 116b. When the radiation rays are incident on ionization box 116b, an ionization current is generated according to an intensity of the incident ray.
The radiation rays from reference radiation source 116d are transmitted through reference object 116e and incident on ionization box 116f. A positive voltage is applied from the high voltage power supply to the outer periphery of ionization box 116f. Upon reception of a radiant ray, ionization box 116f generates an ionization current corresponding to the target value. The ionization current generated upon application of the negative voltage to ionization box 116b and the ionization current generated upon application of the positive voltage to ionization box 116f are electrically coupled by the lead wires connected to the rear portions of ionization boxes 116b and 116f. A composite current is then supplied to amplifier 116g located in the upper portion of the detector. If stick-like cigarette S has the reference density, an output signal from amplifier 116g is set to zero. However, if the density of stick-like cigarette S is higher than the reference density, an output signal from amplifier 116g has a negative level; and if the density of stick-like cigarette S is lower than the reference density, an output signal from amplifier 116g has a positive level. Therefore, the output signal from amplifier 116g corresponds to a deviation in density of stick-like cigarette S from the reference density.
FIG. 4 shows a control circuit of the tobacco content control device of this embodiment. The same reference numerals as in FIGS. 1 to 3 denote the same parts in FIG. 4.
As described above, cut tobacco T is sucked upward through chimney 100 and adhered in a stratiform on the lower side of perforated cigarette conveyor 103 which is located beneath suction chamber 102. Tobacco T is transferred in the allowed direction, and the density of the tobacco layer is detected by first radiometric density detector 106. The radiation rays emitted from radiation source 106a provided in first radiometric density detector 106 are transmitted through tobacco T and incident on ionization box 106b. Since a high voltage is applied to ionization box 106b, a small ionization current is generated thereby. The small current signal is amplified by amplifier 106i and the amplified signal is added to the reference signal from standard signal generator 200. The sum signal is supplied to amplifier 202. An output signal as an amplified signal from amplifier 202 is a voltage signal having a polarity and a magnitude, both of which correspond to the deviation of the density of the tobacco layer from the reference density.
The cut tobacco, the density of which is detected by first radiometric density detector 106, is transferred to the left and excessive tobacco is shaved off by trimming disc 104a. Thereafter the tobacco is rolled in cigarette paper and glue is applied to the paper to form the stick-like cigarette. The density of the stick-like cigarette is measured by second radiometric density detector 116. As described above, in second radiometric density detector 116, radiation rays emitted from radiation source 116a are transmitted through stick-like cigarette S and incident on ionization box 116b. Radiation rays emitted from radiation source 116d are transmitted through reference object 116e and are incident on ionization box 106f. The voltages having opposite polarities are applied to the outer peripheries of ionization boxes 106b and 106f, and the rear portions of these ionization boxes are electrically connected to each other. An amplified output signal from amplifier 116g serves as a voltage signal having a polarity and a magnitude, both of which represent a deviation of the measured density of stick-like cigarette S from the density of the reference object. An output signal from amplifier 116g is amplified by amplifier 204 and is integrated by integrator 222. The integrated output signal from integrator 222 represents a sum of signals corresponding to a deviation of the measured density of the stick-like cigarette from the reference density, i.e., the average deviation of the tobacco density. The operation terminal in the latter stage is driven such that the sum becomes zero, thereby always maintaining the density of the cigarette constant. The output signal from integrator 222 is amplified by amplifier 224 and is supplied as a second detection signal to adder 226.
The output signal from amplifier 202 is supplied to a high pass filter constituted by capacitor 251, resistor 252, and voltage follower 253. The filter is provided for allowing a high frequency component of the output signal to pass therethrough and preventing a low frequency component of the output signal, which is also contained in the output signal from amplifier 204, from passing therethrough. Thus, the instantaneous change of the output signal is delivered from the high pass filter. The time constant of this filter is preferably about one minute. Switch 205 is provided to inhibit the filter function during calibration.
The deviation detection signal free from the DC component is amplified by amplifiers 254 and 255, and the amplified signal is supplied to adder 226 as a first detection signal in the same manner as in the second detection signal.
A sum output from adder 226 is amplified by amplifier 228, and the amplified signal is further amplified by amplifier 230. The output from amplifier 230 is supplied to electrohydraulic servo valve 232. Electrohydraulic servo valve 232 selectively supplies the pressurized oil from gear pump 234 to the upper and lower chambers of cylinder 236 according to the applied voltage, thereby displacing piston 238 upward or downward within cylinder 236. The upward or downward movement of piston 238 is transmitted to trimming disc 104a of trimmer 104 through link 240, shaft 242, link 244, and connecting rod 246 to move trimming disc 104a upward or downward. The position of trimming disc 104a is detected by differential transformer 248 having a primary coil, which is applied with a reference alternative voltage signal of several kHz from oscillator 250 and has its center core connected to piston 238 through shaft 242 and link 240. Therefore, in response to the upward and downward movement of piston 238, a corresponding signal appears in the secondary coil of differential transformer 248 by a mutual induction coupling, and this signal is amplified by amplifier 257. Half-wave portions of the output from amplifier 257 are dropped off to ground by switch 259 which is operate by the output signal of amplifier 250, and the remaining half-wave portions are flattened by low pass filter 256. An output from amplifier 258 is applied to adder 226 as a third input signal.
With the above arrangement, when the sum of the first and second input signals of adder 226 is positive, that is to say, when the tobacco contents are deficient, a voltage appears at the output terminal of adder 226. As a result, the output from amplifier 230 is increased in a positive direction, so that electrohydraulic servo valve 232 slowly changes the flow of oil to push up piston 238, lowering trimming disk 104a through link 240, shaft 242, link 244, and connecting rod 246 to increase the tobacco content. Trimming disc 104a is lowered until the third signal becomes equal to the sum of the signal (i.e., the first signal) from the first radiometric density detector and the signal (i.e., the second signal) from the second radiometric density detector. When the tobacco contents are excessive, the polarities in the foregoing operation are inverted.
The second signal generated by the above arrangement, i.e., the signal generated by second radiometric density detector 116 is obtained by integrating a signal corresponding to the density deviation by integrator 222. The first signal, i.e., the signal generated by first radiometric density detector 106 is a signal corresponding to the density deviation. Accordingly, when there is a difference between the first and second signals, the first signal may be dominant during a short time period, but the second signal is gradually increased by integration to a value which overwhelms the first signal. Therefore, the tobacco content can be determined and controlled according to the first signal with respect to variations of a short period and according to the second signal with respect to variations of a long period.
In this embodiment, first radiometric density detector 106 is arranged in the upstream side of trimmer 104 due to the following reason. In the practical control device, delay (delay time) Td occurs from the detection by the first radiometric density detector to driving of the trimmer o the basis of the detection signal. It is therefore difficult to accurately control the tobacco content of the cigarettes due to the delay time Td. In particular, in order to eliminate variations in higher frequencies, the delay time Td cannot be neglected. In the cigarette manufacturing machine, the first radiometric density detector is located in the upstream side of the trimmer, so that the first detection signal can be feed forwarded and the tobacco contents of cigarettes can be controlled. However, in the feed forward control system mentioned with reference to FIGS. 1 and 4, the tobacco content is transferred along conveyor 103 from first radiometric density detector 106 to trimming device 104. Therefore, transfer time Tt is required between the tobacco content density detection performed by first radiometric density detector 106 and the trimming performed by trimming device 104. That is, transfer time Tt is the time required from the tobacco content to be transferred from detector 106 to trimming device 104. In the case where a trimming device operates at a high speed, as in the case of this embodiment, transfer time Tt is long in comparison with delay time Td. Transfer time Tt and delay time Td can be controlled by adjusting the response speed of amplifier 254 of the feed forward control system. In this case, however, amplifier 254 cannot be set at the maximum response speed, so that the frequency response characteristics are not satisfactory. In the control device of the present invention, delay circuit 400 delays the detection signal output from first radiometric density detector 106 by difference time ΔT such that difference time ΔT corresponds to the difference between transfer time Tt (i.e., a mechanical delay) and delay time Td (i.e., an electrical delay). In this manner, the transfer time required for the tobacco content to be transferred from first radiometric density detector 106 to trimming device 104 is compensated for. As a result of this compensation, only high frequency components, which are picked up from the detection signal supplied from the first radiometric density detector by use of the high pass filter and correspond to an instantaneous variation in the density of the tobacco content, are delayed by difference time ΔT, so that the response speed of the feed forward control system is prevented from lowering.
FIG. 5 shows an example of the construction of delay circuit 400 shown in FIG. 4.
As is shown in FIG. 5, delay circuit 400 operates on the basis of reference power source voltage Vref and can delay a signal by maximum transfer time Tt (Td=0). In delay circuit 400, the high frequency signal picked up by the high pass filter is input through input terminal 401 and its amplitude is adjusted by amplifier 402. The amplitude-adjusted signal is supplied to analog delaying element 403, which is a charge transfer element such as a BBD, and is then output from output terminal 404 after predetermined difference time ΔT. Analog delaying element 403 is connected to clock 405, and this clock 405 is connected to variable resistor circuit 406 for adjusting the signal transmitting frequency of clock 405. Therefore, the signal transmitting frequency of clock 405 is adjusted by varying the resistor of variable resistor circuit 406, and the transfer speed controlled by analog delaying element 403 is adjusted by the clock signal supplied from clock 405. As a result, difference time ΔT is adjusted.
In delay circuit 400 shown in FIG. 5, the analog signal is delayed and output as it is. However, the present invention is not limited to this. For example, the analog signal may be converted into a digital signal by means of an A/D converter before it is delayed, and the delayed digital signal may be converted again into an analog signal by means of a D/A converter.
FIG. 6 shows a drive unit for driving trimming disc 104a for controlling the thickness of the tobacco layer. Referring to FIG. S, piston 238 is vertically slidable in cylinder 236 which is mounted on outer casing 306. Piston 238 is pushed down when pressurized oil is introduced into cylinder chamber 236a through pipe 300, so that the oil in cylinder chamber 236b is drained into the tank through pipe 302 and return pipe 304. Similarly, when pressurized oil is introduced into cylinder chamber 236b to push piston 238 up, the oil in opposite cylinder chamber 236a is drained into the tank through pipe 300 and return pipe 304.
The hydraulic system is kept at a predetermined oil pressure. When an oil pressure exceeding the preset pressure is applied from the gear pump, the oil pressure acts on relief valve 314 through pipe 312, connected midway along pipe 310 between gear pump 234 and electrohydraulic servo valve 232, and is drained through return pipe 316 and filter 308. The pressure in the hydraulic system is controlled by pressure adjusting screw 318.
The upward and downward movement of piston 238 moves connecting rod 320 which is pivotally connected to piston 238. The other end of connecting rod 320 is pivotally connected to link 240, so that upward and downward movement of piston 238 causes link 240 to vertically rock along with shaft 242. Shaft 242 is axially supported by outer casing 306. The rocking movement is transmitted by shaft 242 through link 244 which is fixed to the end of shaft 242 to vertically move connecting rod 246 which is pivotally supported at the other end of the arm. Trimming disc 104a is vertically moved by the upward and downward movement of connecting rod 246.
Link 330 is axially supported at the other end of shaft 242 and is rockable upon rotation of shaft 242. Link 332 is attached to link 330 and is moved vertically upward or downward by the rocking movement of link 330.
The center core of differential transformer 248 is fixed to link 332 so that the core can be vertically moved the same manner as in link 332.
For example, differential transformer 248 is adapted to produce a positive voltage when the core is moved upward and a negative voltage when the core is moved downward, in proportion to the distance of movement. In other words, differential transformer 248 generates a positive voltage when connecting rod 246 is moved upward and a negative voltage when connecting rod 246 is moved downward.
Motor 336 is connected to gear pump 234 through universal joint 338.
As described above, unlike the density detector utilizing air-permeability properties or an electrostatic capacitance change, the second radiometric density detector according to the present invention can generate an accurate detection signal and performs very stable measurement. A deviation of the measured value from the target value is integrated, and the integrated value is fed back to accurately control the average density of the produced cigarettes.
Delay (delay time) occurs until the trimmer is started in response to the detection signal after the signal is measured by the radiographic density detector. This delay time degrades control performance because the control system undesirably oscillates when the response time is shortened to 1/5 or less of the idle time as the reference for the response of the control system as a whole is increased.
A device disclosed by U.S. Ser. No. 705,877 (Japanese Patent Disclosure (Kokai) No. 60-234574 and EPC Laid Open Publication No. 160,799) serves to improve response characteristics so as to minimize the delay time.
Feedforward control in the present invention is open loop control. The deviation from the target value cannot be integrated. However, the response time of the control system can be shortened to a time required for feeding the cut tobacco between the radiometric density detector as the detection terminal and the trimmer as the operation terminal.
An arrangement of feedforward control is described in Japanese Patent Publication No. 40-14560, wherein pressure variations in the air chamber are converted by a bellows into variations in position, and the variations are feed forwarded by a hydraulic unit. However, precision of the signal is poor, and a satisfactory effect cannot be obtained.
According to the present invention, the advantages of feedback control of the radiometric density detector, the electrohydraulic servo mechanism operated as an operation terminal with a short response time, and feed-forward control are combined to obtain an ideal control system operated at high speed in response to the detection signal.
Further, in the feed forward control system, the transfer time, i.e., the time required for the density-detected tobacco content to be transferred to the trimming device is compensated for in consideration of both the mechanical and electrical time delays. As a result, the control system of the present invention operates at a high speed and with high accuracy.
As a result of the above-mentioned control, the response speed of the control device is ten times as high as the control speed of the prior art control device. In addition, the irregularities of the tobacco content of cigarettes can be reduced from 2.5% (prior art) to 1.8%.
In the control device shown in FIG. 4, no delay circuit is incorporated in the feed forward control system. In this case, the irregularities of the tobacco content of cigarettes is reduced to 2.0%. In view of this value, it can be understood that the present invention can remarkably reduce the irregularities of the tobacco content.
Normally, the weight of cigarettes is represented by the following formula:
Weight=(Defective Limit)-3.0×Variation
Therefore, the tobacco contents can be reduced by about 1.7% in the present invention.
As described above, a very high-speed control system can be arranged according to the present invention, and the irregularities of the tobacco content of cigarettes can also be minimized. | 4y
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BACKGROUND OF THE INVENTION
The invention pertains to a butter dish. The object of the invention is to present a butter dish that is also a simple means of portioning butter.
In order to solve this problem, a butter dish is presented.
SUMMARY OF THE INVENTION
For a butter dish according to the invention, the lid is provided with a cutting edge on at least one edge area, so that it is possible to cut off portioned slices of butter by lifting or swiveling the lid away from base plate forming the storage surface for the stick of butter and then lowering or swiveling the lid back onto the base plate.
The cutting edge or the knife can be manufactured as one piece with the lid, or connected with it permanently or as an exchangeable part. Suitable materials for the butter dish are plastic or metal, preferably stainless steel.
The invention makes possible wafer-thin “portioning” of slices of butter. The butter dispenser according to the invention functions with both hard and soft butter. Insofar as an exchangeable cutter or knife is used, a holder for storing a replacement blade can be provided for in the lid.
BRIEF DESCRIPTION OF THE DRAWINGS
The following invention is described in more detail with reference to a sample embodiment in the figures. These depict:
FIGS. 1-3 a butter dispenser designed as a butter dish according to the invention in top view, in side view and in front view;
FIG. 4 a longitudinal section through the butter dispenser of FIGS. 1-3;
FIG. 5 a cross section through the dispenser;
FIG. 6 a top view of the base plate of the dispenser, with the lid suggested;
FIGS. 7 and 8 the removable tray of the movable element of the base plate in bottom view and in top view; and
FIGS. 9 and 10 in top view (with lid removed) and in side view, a further embodiment of the butter dispenser according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
The butter dispenser depicted in the FIGS. 1-8, and generally referred to as 1 , is designed in the manner of a butter dish and includes a bottom plate 2 and a cap-like lid 3 , which when closed lies on the plate 2 with its open bottom side. The interior space 4 formed on the plate 2 and in the lid 3 serves for holding a stick of butter 5 with standard dimensions.
The plate 2 is formed of several parts, i.e. it includes first of all, two plate elements 2 ′ and 2 ″, which are movable in relation to each other in the longitudinal direction L of the essentially rectangular plate 2 and thus also in the longitudinal direction of the butter dispenser, by a distance that is at least equal to, but preferably larger than, half the length of the interior 4 in the direction of the longitudinal axis L. The plate element 2 ′ forms the front of the dispenser 1 and the plate element 2 ″ forms the back. The movability of the two plate elements 2 ′ and 2 ″ relative to each other is indicated by the arrows A and B. As shown especially in FIG. 5, the back plate element 2 ″ fits in the plate element 2 ′ with an integral section 2 ′″ such that it engages surfaces of a recess 6 in the plate element 2 ′ with a multiple dovetailed section located there. The plate element 2 ′ is provided with a plate-like tray 7 that is inserted into an opening of the plate element 2 ′ in such a way that after insertion the top of the tray 7 is even with the top of the two plate elements 2 ′ and 2 ″. The section 2 ′″ of the back plate element 2 ″ fitting in the recess 6 lies against the bottom of the tray 7 . There, a peg-like projection 8 is integrated that engages in an elongated hole, the axis of which is identical to the longitudinal axis L and in which the section of the plate element 2 ″ engaging in the recess 6 is located. With two lateral projections 10 the tray 7 engages in recesses 11 that are located on the top of the plate element 2 ′. This holds the tray 7 with a positive fit on the plate element 2 ′. The projection 8 engaging in the elongated hole 9 also limits the maximum distance of the relative movement between the plate elements 2 ′ and 2 ″. The length of the elongated hole 9 is at least equal to or larger than half the size of the interior 4 in the direction of the longitudinal axis L. In the depicted embodiment the essentially rectangular tray 7 has a width that is equal to the overall width of the interior 4 perpendicular to the longitudinal axis L and parallel to the plane of the plate 2 . The length of the tray 7 is approximately the same as the size of the interior 4 in the direction of the longitudinal axis L.
The lid 3 can be swiveled on its back on the plate element 2 ′ on an axis perpendicular to the longitudinal axis L and parallel to the planes of the plate 2 , with the help of joints 12 that also enable the lid 3 to be removed from the plate 2 , for example when the lid 3 is fully raised from the plate 2 , in order to make it easier to clean the butter dispenser 1 .
On the front, opposite the joints 12 , the lid 3 is provided with a cutting edge 13 extending along the entire front or width of the lid 3 . This cutting edge 13 is located on a wall section 14 of the lid 3 or on the front of this lid, which is shaped in such a way that when cutting off a slice of butter 15 from the stick of butter 5 , this slice rolls in the manner depicted in FIG. 4 in order not to stick to the outer surface of the lid 3 or the wall section 14 . In the depicted embodiment the wall section 14 is concave on its outer surface, on an imaginary axis that is perpendicular to the longitudinal axis L and parallel to the planes of the plate 2 . Due to the concave wall section 14 the edge of the lid 3 is drawn inward on the front in the manner depicted in FIG. 4 .
The butter dispenser 1 is used in such a way that when the plate elements 2 ′ and 2 ″ are pushed together and the tray 7 is located in the plate element 2 ″, the stick of butter 5 is placed on the upper surface of the tray 7 . By closing the lid 3 the butter can be stored in a suitable place, for example in the customary manner.
If a certain amount of butter is to be dispensed, the plate element 2 ′ is moved forward (arrow A) a certain amount relative to the plate element 2 ″ when the lid 3 is open, so that the stick of butter 5 comes to rest under the cutting edge 13 with its edge area adjacent to the wall section 14 . By closing the lid 3 (swiveling on the axes of the joints 12 ) the slice of butter 15 is cut off from the stick of butter 5 by the cutting edge 13 .
After cutting, the front plate element 2 ′ is moved back to the starting position (arrow B), so that the butter dispenser 1 again has small dimensions for storage.
The maximum movement stroke of the plate element 2 ′ relative to the plate element 2 ″ is somewhat larger than half the size of the stick of butter 5 in the direction of the longitudinal axis L. Limiting the movement to this size ensures a stable design of the butter dispenser 1 . In order to be able to cut the other half of the stick of butter 5 into portions in the manner described, the tray 7 is turned.
FIGS. 9 and 10 show as a further possible embodiment a butter dispenser la, which differs from the butter dispenser 1 only in that on the top of the section 2 ′″ of the plate 2 ″ a scale 16 is provided for that works together with the back edge of the plate element 2 ′ and indicates the quantity or mass of the stick of butter or slice of butter 15 cut off.
In addition, a stop 17 is provided for on the top of the plate element 2 ′ or on the storage surface for the stick of butter 5 formed there, enabling exact positioning of the stick of butter 5 .
The invention has been described above with reference to sample embodiments. Of course, numerous alterations and adaptations are possible without abandoning the underlying inventive idea.
List of reference symbols
1 butter dispenser
2 plate
2 ′, 2 ″ plate element
2 ′″ section
3 lid
4 interior
5 stick of butter
6 recess
7 tray
8 projection
9 elongated hole
10 projection
11 recess
12 joint
13 cutting edge
14 wall section
15 slice of butter
16 scale
17 stop | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is the US National Stage of International Application No. PCT/DE02/03521, filed Sep. 19, 2002 and claims the benefit thereof. The International Application claims the benefits of German application No. 10147423.7 filed Sep. 26, 2001, and of German application No. 10230127.1 filed Jul. 4, 2002 all three of the applications are incorporated by reference herein in their entirety.
FIELD OF INVENTION
[0002] The invention relates to a method for processing consistent data sets by an asynchronous application of a subscriber in an isochronous, cyclical communications system.
BACKGROUND OF INVENTION
[0003] Data networks are formed from a number of network nades and allow communication between a number of subscribers. Communication here means the transmission of data between the subscribers. The data to be transmitted in this case is sent as data telegrams, which means that the data is packed into one or more packets and sent in this form over the data network to the appropriate recipient. The term data packet is thus used. The term transmission of data is used in this document fully synonymously with the above-mentioned transmission of data telegrams or data packets.
[0004] For networking in switchable high-performance data networks for example, especially Ethernet, the subscribers are interlinked via coupling nodes. Each coupling node can be connected to more than two subscribers and can also be a subscriber itself. Subscribers are for example computers, Programmable Logic Controllers (PLC) or other machines which exchange electronic data with other machines and especially process it.
[0005] In distributed automation systems, for example in the area of drive technology, specific data must arrive at specific times at the intended subscribers and must be processed by the recipients. This is referred to as realtime-critical data or realtime-critical data traffic since if the data does not arrive at its intended destination at the right time this can produce undesired results at the subscriber.
[0006] Similarly the use of an isochronous, cyclical communication system is known from the prior art. This is taken to mean a system consisting of at least two subscribers that are linked via a data network for the purposes of mutual exchange of data or mutual transmission of data. In this case data is exchanged cyclically in equidistant communication cycles which are specified by the communication clock used by the system. Subscribers, such as central automation devices, Programmable Logic Controllers, controls, checking units, computers, machines that exchange electronic data with other machines, drives, actors or sensors, execute specific applications. In this document control units are taken to mean closed-loop controllers or control units of all types. Typical examples of communication systems used for data transmission are bus systems such as Field Bus, Profibus, Ethernet, Industrial Ethernet, FireWire or also PC-internal bus systems (PCI), etc. In such systems data telegrams are fed into the data network at fixed points for transmission by a subscriber.
[0007] For synchronous applications the processing of the data is synchronized with the communication cycle. By contrast the processing of data in asynchronous applications is not synchronized with the communication cycle. This reading and writing of data by an asynchronous application can occur at any point in time. This produces special requirements for inclusion of an asynchronous application into an isochronous, cyclical communication system. Basically consistent data is to be sent and read by a subscriber. Consistent data is data which relates to the same time interval. Subscribers with asynchronous applications known from the prior art have the consistency buffer and a communication memory. If the application is to process data from a specific address range in the communication memory, this data is first copied into the consistency buffer.
[0008] Only then does the application access the data in the consistency buffer to read it. All addresses in the communication memory can thus be overridden while the application works with the consistent data in the consistency buffer.
[0009] The application first writes data into the consistency buffer while consistent data can be sent at the same time from the communication memory to further subscribers. After write access by the application and the sending of data has ended the data written in this way is copied from a consistency buffer to the communications memory. The consistent data is stored here for onwards transmission. The copying processes lead to delays in such cases.
[0010] [0010]FIG. 1 illustrates a system from the prior art for processing consistent data blocks during read access. The communications memory 1 has a receive zone 2 and a transmit zone 3 . The receive zone 2 is linked to the receive buffer 4 and the consistency buffer 5 . The transmit zone 3 is linked to the consistency buffer 5 and the transmit buffer 6 . Data set DS A from address range AB A to which the application has access for reading is located in the consistency buffer.
[0011] [0011]FIG. 2 illustrates the sequence of read access by the application in the system shown in FIG. 1 Before read access the data set DS A is copied from the receive zone 2 of the communication memory 1 to the consistency buffer 5 . Data set A is data which can be or could be accessed by the application during a read access. Data set DS A is to be consistent during a read access and originates from the address range AB A in the receive zone 2 of communication memory 1 .
[0012] Because the data of the consistency block requests by the application is saved in the consistency buffer, newly received data of receive buffer 4 which lies in the address range of the consistency block can subsequently be stored in the receive zone 2 of communication memory 1 . Read access by the application to the data set DS A in the consistency buffer 5 takes place independently of this storage process. During the read access files can be copied from the receive buffer 4 into the receive zone 2 of communication memory 1 .
[0013] [0013]FIG. 3 shows the system from FIG. 1 during a write access by the application.
[0014] [0014]FIG. 4 illustrates the sequence of a write access by the application. While the application is writing data set DS B into the consistency buffer 5 data is forwarded from the transmit zone 3 of the communication memory 1 to the transmit buffer 6 . Data set DS B is to be copied into a specific address range AB B of the transmit zone 5 of the communication memory 1 . Before this copying process takes place all data from the address range AB B which is to move during a copying process from the transmit zone 3 to the transmit buffer 6 should be forwarded to the transmit buffer 6 . The data set DS B can thus only be copied from the consistency buffer 5 into the transmit zone 3 of the communication memory 1 once both the write access and the forwarding of data from the address range B are completed.
SUMMARY OF INVENTION
[0015] The object of the invention is thus to minimize delays which can arise as a result of the necessary copying processes at a subscriber with an asynchronous application into an isochronous cyclical communications system.
[0016] The object of the invention is achieved by a method with the features of the Independent Patent claims 1 and 2 . Preferred embodiments of the invention are specified in the dependent patent claims.
[0017] With the method in accordance with the invention, before it can be read in the asynchronous application, data is advantageously not copied into the consistency buffer. The application accesses the communication memory directly to read the data. During read access data which is destined for an address range in the communication memory to which the application has access or could have access is copied from the receive buffer into the consistency buffer. Only this data will be copied from the consistency buffer to the communication memory at the end of the reader access. A copying process is only needed if data is received during read access from the receive buffer which is addressed to an address range to which the application has access or could have access.
[0018] In a further method in accordance with the invention the application writes data directly into the communication memory. Data from an address range to which the application has access or could have access during writing is written into the consistency buffer before write access. Here it is ready for transmission while if the application is writing data to the communication memory. It is advantageous that the forwarding of the data from the consistency buffer to the transmit buffer can be interrupted as soon as write access to the reserved address range has been ended and instead current data can be forwarded from the communication memory to the transmit buffer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] A preferred exemplary embodiment of the invention is explained in more detail below with reference to the diagrams. The drawings show:
[0020] [0020]FIG. 1 a block diagram of a system from the prior art during a read access
[0021] [0021]FIG. 2 a state transition diagram during read access in accordance with the prior art,
[0022] [0022]FIG. 3 a block diagram or a system from the prior art during a write access,
[0023] [0023]FIG. 4 a state transition diagram during write access in accordance with the prior art,
[0024] [0024]FIG. 5 a block diagram of a system in accordance with the invention during a read access,
[0025] [0025]FIG. 6 a state transition diagram during a read access in accordance with the invention,
[0026] [0026]FIG. 7 a block diagram of a system in accordance with the invention during a write access,
[0027] [0027]FIG. 8 a state transition diagram during a write access in accordance with the invention,
[0028] [0028]FIG. 9 a flowchart of read access in accordance with the invention,
[0029] [0029]FIG. 10 a flowchart of write access in accordance with the invention.
DETAILED DESCRIPTION OF INVENTION
[0030] [0030]FIG. 5 shows a system in accordance with the invention of a subscriber of an isochronous, cyclical communication system for processing consistent data blocks during a read access. The system in accordance with the invention also possesses a communication memory 7 with a receive zone 8 and a transmit zone 9 , a consistency buffer 10 , a receive buffer 11 and a transmit buffer 12 . The system in accordance with the invention differs significantly from the prior art by linking of the receive buffer 11 and the transmit buffer 12 with the communication memory 7 and the consistency buffer 10 . Using the multiplexer 13 a link can be established between both the receive buffer 11 and the consistency buffer 10 and also between the receive buffer 11 and the communication memory 7 . Likewise by means of multiplexer 14 an alternative link between the transmit buffer 12 and the communication memory 7 or the consistency buffer 10 can be established. The job interface 15 controls the multiplexers 13 and 14 .
[0031] In the case shown the application 16 reads data from the address range AB C of the consistency block KB C in the receive zone 8 of the communication memory 7 , while data set DS C is being forwarded from receive buffer 11 to consistency buffer 10 which is actually intended for address range AB C. To ensure the consistency of the data read by the application, the data set DS C will thus be copied into the consistency buffer. The job interface 15 controls the multiplexer 13 so that there is a connection between the receive buffer 11 and the consistency buffer 10 . The read access has no effect on the forwarding of data from the transmit zone 9 to the transmit buffer 12 . The transmit zone 9 is thus connected via the multiplexer 14 to the transmit buffer 12 .
[0032] The use of the consistency buffer 10 during read access is thus only necessary because the data set DS C is destined for address range AB C to which the application 16 has access or could have access. Otherwise the data can be forwarded directly from the receive buffer 11 to the receive zone 8 of the communication memory 7 . The job interface 15 will then establish a connection between at the receive buffer 11 and the receive zone 8 .
[0033] [0033]FIG. 6 illustrates the sequence of read access in accordance with the invention. During read access by the application to the receive zone 8 of the communication memory 7 a data set DS C which is destined for the address range AB C of the consistency block KB C is copied from the receive buffer 11 to the consistency buffer 10 . After read access has ended the data set DS C will be copied from the consistency buffer 10 into the receive zone 8 of the communication memory 7 . Data is sent and received independently of the read access.
[0034] [0034]FIG. 7 shows the system from FIG. 5 during a write access. The address range of the consistency block KB D will be writtenby application 16 directly in the transmit zone 9 of the communication memory 7 . The data set DS D from the address range of the consistency block KB D is located in the consistency buffer 10 . It is advantageous that in transmit buffer 12 a complete set of data 17 is “in stock” for transmission. In stock here means that the set includes all data which is to be transmitted during the next transmit procedure.
[0035] [0035]FIG. 8 illustrates the sequence of a write access in accordance with the invention in the system of FIG. 7. Before write access by application 16 the data set DS D will be copied from the address range AB D of the consistency block KB D which the application can or could write to during the write access from the transmit zone 9 of the communication memory 7 to the consistency buffer 10 . During write access consistent data can be transmitted from a data set DS D from the consistency buffer 10 to the transmit buffer 12 . The job interface 15 therefore connects the consistency buffer 10 with the transmit buffer 12 .
[0036] If write access by the application 16 is ended before the ending of the copying process of data set DS D from the consistency buffer 10 to the transmit buffer 12 the copying process will be aborted. To guarantee the transmission of a complete data set from the transmit buffer 12 a data set 17 must therefore be kept in stock in this.
[0037] After the write access data can be forwarded from the address range AB D again and from the transmit zone 9 of the communication memory 7 to the transmit buffer 12 . Data which is not located in address range AB D can also be forwarded during write access from the receive zone 9 of the communication memory 9 to the transmit buffer 12 . Data can be received independently of write access at the receive port and sent at the transmit buffer 12 .
[0038] [0038]FIG. 9 shows a flowchart of a read access in accordance with the invention. First of all an address range AB C in the receive zone of the communication memory is reserved by a consistency block KB C (step 18 ). “Reservation by a consistency block” means in this connection that data can neither be copied from the receive buffer into the address range occupied by a consistency block, nor from an address range occupied by a consistency block into the transmit buffer. The address range C includes addresses to which the application has access or could have access during a read access.
[0039] In the next step (step 19 ) the application accesses the consistency block KB C in the communication memory for reading. At the same time the data set DS C which is addressed to addresses in the address range AB C of the consistency block KB C is copied from the receive buffer to the consistency buffer.
[0040] After the end of read access the consistency block KB C is released (step 20 ). The address range AB C can now be written again with data from the transmit buffer.
[0041] Data which was written during the read access into the consistency buffer can finally be copied into the address range AB C of the communication memory (step 21 ).
[0042] [0042]FIG. 10 shows a flowchart of a write access in accordance with the invention. A data set DS D in address range AB D of the transmit zone 9 of the communication memory which is written or could be written by the application during a write access will first be copied into the consistency buffer (step 22 ).
[0043] The address range AB D will then be occupied by the consistency block KB D (step 23 ). Thus data can no longer be forwarded from the address range AB D to the transmit buffer.
[0044] During the write access however data of the data set DS D can be forwarded from the consistency buffer to the transmit buffer (step 24 ).
[0045] After write access has ended the consistency block KB D will be released (step 25 ). Data can again be forwarded from the address range AB D to the transmit buffer.
[0046] The copying process of data of data set DS D from the consistency buffer to the transmit buffer will be aborted if it is not completed before the end of write access (step 26 ) and replaced by the current data from the communication memory.
[0047] A current data record is then copied from the address range AB D of the consistency block KB D to the transmit buffer (step 27 ). | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to pressure control devices and has specific reference to a device of this kind intended for use in a pyrotechnical load ejector of the type used for jettisoning loads on aircrafts.
2. Description of the Prior Art
As a rule, jettisoning loads carried by the lower structure of aircrafts is attended by a powerful thrust for causing the loads to move as fast as possible away from the aircraft. The energy required for this purpose is supplied in most instances by a pyrotechnical device acting on pistons-type ejectors. However, the very sudden pressure increment produced when firing this device is detrimentalin that both the load to be jettisoned and the aircraft structure in that both the load to be jettisoned and the aircraft structure are exposed to an abnormally high though momentary stress, considering the total energy implemented.
SUMMARY OF THE INVENTION
It is the essential object of the present invention to provide an adjustable device capable of permitting the proper use of the energy generated by the pyrotechnical means while limiting the pressure thus developed to preselected and substantially constant value throughout the ejected time. The device according to this invention is based on the well known regulation principal consisting in submitting a value or spool member on the one hand to the pressure necessary for partially closing the fluid passage so that the resultant loss pressure will limit the downstream pressure, and on the other hand to the force of a calibrated spring acting in the direction to open said passage when the pressure tends to drop below predetermined threshold.
The above principle is adapted according to this invention to the specific conditions of operation required for ejecting load from an aircraft, which implies:
THE USE OF TWO REGULAR PYROTECHNICAL IMPELLERS SO THAT FIRING A FIRST IMPELLER CAUSES BY PROPAGATION THE FIRING OF THE OTHER IMPELLER;
THE NECESSITY OF CAUSING THE THRUST APPLIED TO ONE EJECTION PISTON TO HAVE A VARIABLE VALUE IN RELATION TO THAT OTHER PISTON;
THE PROTECTION OF THE COMPONENET ELEMENTS AGAINST SOILING CAUSED BY THE POWDER COMBUSTION, AND
THE CONSTRUCTION IN A RELATIVELY SMALL VOLUME OF AN INTERCHANGEABLE DEVICE ADAPTED TO BE EASILY REMOVED AND REPLACED.
For this purpose, the present invention provides a single compact unit comprising in combination the component elements capable of meeting the above-listed requirements.
BRIEF DESCRIPTION OF THE DRAWINGS:
The single FIGURE illustrates in vertical axial section the pressure control device adapted to receive the pyrotechnical impellers connected to the cylinders of the ejection pistons (not shown).
DESCRIPTION OF THE PREFERRED EMBODIMENT
The unit illustrated comprises a main body 1 having associated therewith detachable members permitting the machining of said body and the assembling of the internal component elements thereof, which comprise a cylinder 2, having its axis aligned with that of a spool valve 9, said cylinder 2 being adapted for this purpose to enclose a coil compression spring 10 associated with the regulating spool valve 9, a body 3 constituting the shells of the cocks controlling the supply of pyrotechnical gas to the ejection pistons, a cap 4 fitted to the end of body 1 opposite said cylinder 2 and through which the pressure is directed against said spool valve 9, and a screw 5 fitted to the bottom of the main body 1 opposite the cock body 3 facilitating the access to the gas inlet passage leading to the spool valve 9.
Conduits 28 lead to respective ejection cylinders 29 containing an injection piston 30, as shown in chain dotted lines the drawing.
A pair of cavities 6 and 7 are formed in said body 1 for mounting the main impellers (not shown), a third cavity 8 being provided for receiving an emergency impeller, also not shown.
The regulating spool valve 9 has one end responsive to the pressure of the return spring 10 housed in cylinder 2 and reacting at its end opposite said spool valve 9 against a piston 11 of which the axial position is adjustable through any suitable means, shown diagrammatically in the drawing in the form of a thrust screw 12 engaging a tapped hole formed in a fixed member.
The gases released or generated when firing the impellers penetrate into an annular groove 13 surrounding the shaped section of reduced diameter of the regulating spool valve 9 providing through an annular seat 14 and along its axis a passage of variable cross-sectional area leading to an annular chamber 15 the outlet port 16 of which is connected to the inlet side of a pair of cocks 17, 18 so that by opening these cocks more or less it is possible to adjust at will the efficiency of the ejection piston (not shown) actuated by said gases under the control of each cock 17, 18. The portion of spool 9 which extends within the annular groove 13, seat 14 and chamber 15 is substantially frusto-conical with its minor base located on the side of spring 10 so that any movement of spool 9 against the force of spring 10 (i.e., to the right as seen in the Figure) will throttle the passage between the gas inlet groove 13 and the downstream annular chamber 15. The spool valve 9 carries in suitable grooves, at the ends of its frusto-conical regulating section, a pair of O-rings 19, 20 beyond which the spool valve 9 can slide in bearing-forming anti-friction bushings 21, 22.
The spool valve 9 is urged against the force of its return spring 10 by a piston 23 engaging the spool and opposite said spring 10 without requiring any accurate alignment with the spool valve, and an auxiliary spring 24 is provided for constantly urging the piston 23 against the spool 9, as shown. The rod of piston 23 is guided within the cap 4 and responsive to the gas pressure downstream of said spool via a passage 25 formed in said cap 4 and in the main body 1, said passage 25 communicationg with the outlet port of the spool valve.
The detachable block 1 may be secured through any suitable quick-fastening means to aircraft structure, for example by using studs or bolts as illustrated diagrammatically at 26 and 27.
The above-described device operates as follows:
The relative opening valves or cocks 17, 18 is adjusted beforehand, as a function of the load behaviour during the ejection, as observed during previous tests. The initial stress of spring 10 is also adjusted by means of screw 12 or any suitable system, for example an eccentric system, with due consideration for the maximum permissible efforts for both the load and the aircraft structure. To any initial stress or tension of spring 10 there corresponds, all other factors being equal, a maximum downstream pressure, as will be explained presently.
The impellers are introduced into the corresponding cavities 6, 7 and 8, and fired according to the known and conventional methods, not illustrated, the relative communication between these impellers being designed with a view to produce their mutual firing by propagation according to the known methods.
When firing the impellers the gas thus generated flows through the inlet port 13, chamber 15, outlet port 16 and passage 25, thus exerting a strong pressure against the piston 23 which forces the spool valve 9 to the right (as seen in the Figure) against the force of spring 10. If the force resulting from the pressure thus exerted firstly against piston 23 exceeds the initial force of spring 10, the spool 9 will move to the right, thus throttling the gas passage as the major base of the frusto-conical section of spool 9 approaches the seal 14. The loss of pressure thus produced counteracts and maintains the downstream pressure. When the pressure drops as a consequence of the exhaustion of the initial energy, the pressure exerted on piston 23 decreases likewise and spring 10 forces again to the left the spool 9, whereby the cross-sectional passage area between upstream and downstream increases, and the downstream pressure is maintained, at least as long as there is an upstream power available under a sufficient pressure.
It is clear that there is a constant state of equilibrium between the downstream pressure exerted on piston 23 and the force of spring 10, thus providing the necessary regulation, and on the other hand it is possible to select or control the maximum downstream pressure by adjusting the initial tension or prestress of spring 10.
The spool valve 9 on which considerable efforts are exerted has its end slidably mounted in suitable bushings 21, 22 made of anti-friction or self-lubricating materials, said bushings being protected against soiling by the combustion products by the presence of the O-rings 19 and 20. To avoid the presence of aligned bearings or bushings, the pressure is exerted on spool member 9 through the medium of an independent piston 23 constantly kept in contact with said spool 9 by the compression spring 24, in order to prevent any hammering or shock between these two members. Reference has already been made in the foregoing to a block or casting comprising several component elements in order to facilitate the machining thereof and permit the assembling of the mechanism.
Finally, it is on purpose that the mounting of this device is relatively simple, in order to facilitate the quick replacement of worn or faulty parts with new ones, and also with due regard for the relatively frequent cleaning operations made necessary by the detrimental presence of power combustion residues.
Although a single form of embodiment has been described hereinabove and illustrated in the appended drawing, it will readily occur to those conversant with the art that various modifications and changes may be brought thereto without departing from the basic principle of the invention as set forth in the appended claims. | 4y
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to, and the benefit of, Japan Patent Application No. 2007-104666, filed on 12 Apr. 2007, in the Japan Patent Office, the disclosure of which is incorporated herein by reference in its entirety.
FIELD
The present invention relates to electronic devices for surface mount, more particularly to electronic devices in which short-circuiting by solder is prevented when the devices are mounted on a circuit board or the like.
DESCRIPTION OF THE RELATED ART
Crystal devices are widely known for use as frequency-controlling elements such as crystal units, oscillators, and filters. Crystal devices are mounted on various types of circuit boards of electronic devices including, but not limited to, communication devices. In recent years, crystal devices for surface mount have been developed for mounting on circuit boards with other electronic devices, such as resistors and capacitors. In general, the electronic devices are mounted, using a surface-mount machine, on the circuit board to which solder paste has been applied. Then, the board on which the electronic devices have been placed is conveyed through a reflow furnace to achieve soldering of the electronic devices to the board.
In many instances the electronic devices must be closely arranged on the circuit board to satisfy current demands of high integration and miniaturization. Consequently, pads (corresponding to respective external terminals) for the electronic devices are situated closely together on the circuit board. As miniaturization of electronic devices for surface mount has progressed, the distances between external terminals on the electronic devices have narrowed, requiring corresponding reductions of distances between external terminals on the board. Consequently, when soldering the electronic devices on the circuit board, solder tends to overflow between external terminals and cause short-circuits. Even in situations in which short-circuits do not form between individual external terminals, solder overflow may become ball-shaped and thus adversely affect other regions of the mount board.
FIG. 7 shows a piezoelectric oscillator 200 , having a base board 210 , mounted on a circuit board PB. Specifically, the circuit board PB includes a pad 115 , and solder paste SOL has been applied to the pad 115 . When the piezoelectric oscillator 200 enters a reflow furnace after being placed in a state in which a predetermined amount of solder SOL has been applied, a solder ball is formed between the base board 210 and the circuit board PB. Thus, short-circuiting may be produced between the external terminals 215 .
If a somewhat small amount of solder paste is applied, the desired electrical connection between the external terminal 215 and the pad 115 may be insufficient. It is also difficult to detect whether or not connections between the electronic devices and the circuit board are satisfactory after performing solder reflow. Furthermore, if a connection fault should arise between an electronic device and the circuit board, the faulty connection state between the electronic device and wiring on the board may not be readily detected, which results in decreased product yield.
SUMMARY
To address the problems described above, an object of the present invention is to provide electronic devices for surface mount that prevent solder from overflowing between external terminals of the electronic device or between pads on a circuit board.
An electronic device for surface mount according to the first aspect comprises a base board made from an insulating material. An embodiment of the device includes at least one external terminal for surface mount on an outer surface. A groove is formed around the external terminal on a surface to be mounted on the printed circuit board. With this embodiment, even when solder is applied to a circuit board in a somewhat large amount during surface mounting, any over-flowed solder enters the groove. Hence, short-circuiting between external terminals is much reduced.
A base board on the electronic device for surface mount according to the second aspect comprises a resin board made of a thermoset resin. The groove is formed by thermal or mechanical processing. By making the base board on the electronic device as a thermoset resin board, the groove can be formed by thermal processing, e.g., laser processing. If mechanical processing is used, the groove can be formed by drilling or routing, for example.
A base board on the electronic device for surface mount according to the third aspect comprises a ceramic board. The groove is formed by embossing or stamping, for example. The external terminals can be printed using metallized ink. By making the base board on the electronic device of ceramic, the groove may be formed by embossing or stamping before performing calcination, followed by metallization to form the external terminals.
With an electronic device for surface mount according to the fourth aspect, the depth of the groove is from 0.1 mm to 80% of the thickness of the base board. By staying within this range, solder overflow is satisfactorily arrested. If the groove depth exceeds 80% of the thickness of the base board, the base board becomes too weak for adequate durability.
With an electronic device for surface mount according to the fifth aspect, the width of the groove is from 0.1 mm to 2.0 mm. By staying within this range, solder overflow is satisfactorily arrested.
The electronic devices can include crystal oscillators and crystal units. Crystal oscillators are categorized as large-sized among electronic devices. Consequently, a rather large amount of solder is applied to the circuit board. The present invention is especially advantageous for this application.
Electronic devices for surface mount according to the present invention advantageously prevent solder from overflowing between external terminals of the electronic device or between corresponding pads on a circuit board to which the electronic devices are mounted.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of an exemplary surface-mount piezoelectric oscillator 100 .
FIGS. 2A and 2B are elevational and plan views of a base board with external terminals.
FIGS. 3A and 3B are elevational views of a piezoelectric oscillator being mounted on a circuit board.
FIGS. 4A , 4 B, and 4 C are perspective, elevational, and plan views, respectively, of a crystal oscillator.
FIGS. 5A-5D depict exemplary steps in a method for manufacturing a ceramic layer for use a bottom layer.
FIGS. 6A-6D depict representative cross-sectional shapes of grooves.
FIG. 7 is a side view of a conventional piezoelectric oscillator mounted on a circuit board.
DESCRIPTION OF PREFERRED EMBODIMENTS
The invention is described in connection with representative embodiments, with reference to the drawings.
Construction of Piezoelectric Oscillator
FIG. 1 is a cross-sectional view of an embodiment of a surface-mounted, high-stability piezoelectric oscillator 100 of the temperature-controlled type (hereinafter referred to as a “piezoelectric oscillator”). The piezoelectric oscillator 100 comprises a base printed circuit board 10 (called a “base board”) and a sub printed circuit board 40 . The base board 10 is made of an insulating material. On the sub printed circuit board 40 are mounted a temperature-control circuit and/or electronic components 31 for an oscillation circuit. Also mounted to the sub printed board 40 is a crystal-vibrating 32 affixed using conductive adhesive 21 . On the under-surface of the base board 10 , external terminals 15 are arranged in multiple (e.g., four or six) places. The external terminals facilitate mounting of the piezoelectric oscillator 100 on the surface of a circuit board PB (refer to FIG. 3 ). To visually observe a meniscus state of soldering after surface-mounting, the external terminals 15 can be electrically connected with the electronic component 31 or the crystal-unit 32 by plated wiring or by lead wires on the surface of the base board 10 .
Also mounted to the base board 10 are first ends of respective metal supports 50 made of brass or the like. The first ends are inserted in recesses 11 and affixed using conductive adhesive 21 . Opposing second ends of the metal support 50 are affixed to the sub printed circuit board 40 using conductive adhesive 21 . The entire assembly is covered with a metal case 48 so as to seal the two-tiered base board 10 and sub printed circuit board 40 . The piezoelectric oscillator 100 having such construction generally has a size from approximately 3 mm square to approximately 50 mm square.
FIGS. 2A-2B depict the base board 10 and external terminal 15 . FIG. 2A is an enlarged view showing the metal support 50 affixed to the base board 10 , and also showing an external terminal 15 . FIG. 2B shows the under-surface of the base board 10 .
As shown in FIG. 2A , the metal support 50 includes a flange 51 and a shaft 54 . The shaft 54 has a shank 52 extending from the flange 51 . The diameter of the shaft 54 is approximately 0.03 mm to approximately 1 mm, and the diameter of the flange 51 is approximately 0.04 mm to approximately 3 mm. The flange 51 may have a diameter of approximately twice the diameter of the shaft 54 .
The recess 11 is formed in the base board 10 such that the shank 52 may be inserted therein. The base board 10 is made of a glass-epoxy laminate or other insulating material. The thickness of the base board 10 is approximately 0.6 mm to approximately 3 mm, and the depth of the recess 11 is approximately 90% to approximately 30% of the thickness of the base board 10 . Alternatively, the base board 10 can be made of an insulating material other than glass-epoxy laminate, such as a thermoset resin for glass cloth or glass non-woven fabric base material, an epoxy-resin laminate, a composite laminate, a paper-base epoxy-resin laminate, or a paper-base phenolic resin laminate. Recess or groove processing may be easily applied to these various materials by laser processing, drilling, routing, or the like.
The diameter of the recess 11 desirably is smaller than the diameter of the flange 51 , and equal to or larger than the diameter of the shank 52 . The recess 11 can be formed in the base board 10 using a flat router in the edge. Copper plating 12 is applied around the recess 11 . The external terminal 15 and the copper plating 12 are electrically connected to each other. The flange 51 of the metal support 50 and the copper plating 12 are affixed using the conductive adhesive 21 .
The groove 13 extends at least part way around the external terminal 15 . In this regard, the groove 13 a is formed only in the under-surface of the base board 10 destined to be surface mounted on the circuit board PB (refer to FIG. 3 ). The groove 13 a does not extend up the side surface in this embodiment. The groove 13 is configured to facilitate visual observation of a meniscus state of solder on the external terminal 15 from the side surface of the piezoelectric oscillator 100 .
The groove 13 b is formed entirely in the under-surface of the circuit board PB because processing is easily applied to such end. The depth of the grooves 13 ( 13 a and 13 b ) ranges from 0.1 mm to 80% of the thickness of the base board 10 . The width of the groove 13 is 0.1 mm to 2.0 mm. With these combinations of depth and width of the groove 13 , solder overflow is suppressed in the groove 13 , especially considering the size of the surface-mount piezoelectric oscillator 100 . (Solder overflow is still dependent on the amount of solder SOL applied to the circuit board PB, but this variable can be controlled.) In this embodiment, solder overflow is suppressed by flow of excess solder into the groove 13 a or into the groove 13 b , or into both grooves.
Mounting Piezoelectric Oscillator on Circuit Board
FIGS. 3A-3B show a piezoelectric oscillator 100 being mounted on the circuit board PB. FIG. 3A is a side view of the piezoelectric oscillator 100 before mounting, and FIG. 3B is a side view of the piezoelectric oscillator 100 after mounting. In FIG. 3A pads 115 are formed on a circuit board PB on which an electronic device or the like is mounted. The pads 115 form respective parts of a circuit. Solder SOL is applied to the pads 115 by application of a solder paste followed by passage through a reflow furnace of infrared type or hot-air type (not shown).
Solder is usually applied to the pads 115 at a predetermined thickness by application of solder paste SOL using a squeegee (not shown) that urges the paste through a perforated metal mask made from stainless steel (not shown). Then, the piezoelectric oscillator 100 is mounted to regions in which the solder SOL has been applied. The mounting of the piezoelectric oscillator 100 is usually performed by a numerically controlled (NC) surface-mounting machine.
As shown in FIG. 3B , during mounting of the piezoelectric oscillator 100 , superfluous solder SOL may enter the groove 13 . This flow into the groove prevents formation of solder balls or the like even if a somewhat excessive amount of the solder paste is transferred to the pads 115 . A solder resist could be formed between the external terminals 15 to avoid generating short-circuits between the external terminals. However, with the depicted embodiment, the need for solder resist is eliminated because the grooves accommodate the excess solder.
The shape of the external terminal 15 can be similar to conventional shapes. The external terminals 15 on the under-surface of the base board 10 can extend up the side surfaces of the base board 10 . This configuration allows visual observations of a meniscus state of soldering.
Construction of Crystal Oscillator
A crystal oscillator 150 is now described with reference to FIGS. 4A-4C . FIG. 4A is an overall perspective view; FIG. 4B is a cross-sectional view; and FIG. 4C is a top view with the metal lid 61 removed. The crystal oscillator 150 is a surface-mount type, comprising an insulating ceramic package 60 and a metal lid 61 that covers the package. The metal lid 61 desirably is made of Kovar (iron (Fe)/nickel (Ni)/cobalt (Co) alloy). The ceramic package 60 comprises a bottom ceramic layer 60 a , a wall ceramic layer 60 b , and seat ceramic layer 60 c . These layers are punched from green sheets formed from a slurry containing ceramic powder including alumina as a main material, a binder, and the like. Instead of using ceramic powder containing alumina as the main ingredient to form the material of the ceramic package 60 , any of various other materials can be used such as glass ceramic, zero X-Y shrinkage glass ceramic substrate, aluminum nitride, mullite, or the like. As understood from FIG. 4B , the package 60 constructed from the ceramic layers 60 a - 60 c forms a cavity. The electronic component(s) 31 and/or tuning-fork type crystal-vibrating piece 33 is mounted in the cavity.
Copper plating 12 , electrically connected with the electronic component(s) 31 , is formed in a portion of the top surface of the seat ceramic layer 60 c . At least two external terminals 15 , formed in the lower surface of the ceramic package 60 , are mounted on the surfaces of the pads 115 of the circuit board PB. The copper plating 12 connects to the external terminals 15 . A metallized layer is provided on the upper surface of the wall ceramic layer 60 b . A sealing material 39 , made from a low-temperature-brazing filler metal, is formed on the metallized layer for bonding the metal lid 61 . The wall ceramic layer 60 b and the metal lid 61 are welded together by the sealing material 39 .
The tuning-fork type crystal-vibrating piece 33 has, in its proximal portion, an adhesion region intended to be electrically connected using conductive adhesive 37 . Specifically, copper plating 12 , electrically connected with an external electrode, is formed on the seat ceramic layer 60 c , and the proximal end of the tuning-fork type crystal-vibrating piece 33 is bonded to the seat ceramic layer 60 c using the conductive adhesive 37 . As affixed, the crystal-vibrating piece extends parallel to the bottom ceramic layer 60 a and produces a predetermined vibration.
As disclosed in FIGS. 4A-4C , a groove 13 is formed around the external terminals 15 of the crystal oscillator 150 . Consequently, when mounting the crystal oscillator 150 on the circuit board PB, any superfluous solder SOL flows into the groove 13 . Hence, even if an unintended larger amount of solder paste is applied to the pads 115 (e.g., using a squeegee), a solder ball or the like is not formed, and short-circuits are avoided.
Manufacture of Bottom Ceramic Layer
FIGS. 5A-5D show a method for manufacturing the ceramic package 60 , specifically the bottom ceramic layer 60 a . FIG. 5A shows a first green sheet 60 a 1 made from alumina. The lattice-shaped broken lines 69 denote expected partition lines. In this example, a portion of the first green sheet enclosed by the parting lines 69 is a rectangle of 5 mm by 7 mm. To form the groove 13 , as shown in FIG. 5A , rectangular through-holes 18 are formed in the first green sheet 60 a 1 along the parting lines 69 using a punching machine or the like. The thickness of the first green sheet 60 a 1 dictates the depth of the groove 13 .
Next, a second green sheet 60 a 2 sized identically to the first green sheet 60 a 1 is prepared. The second green sheet 60 a 2 is a flat plate lacking the through-holes. Then, the first green sheet 60 a 1 and second green sheet 60 a 2 are stacked. Thus, as shown in FIG. 5B , the through-holes 18 become blind via-holes 19 .
Next, when the stacked sheet is cut along the parting lines 69 to form multiple units each destined to become a bottom ceramic layer 60 a having the overall configuration as shown in FIG. 5C . Then, when the wall ceramic layer 60 b and seat ceramic layer 60 c are stacked on and integrated with the bottom ceramic layer 60 a , a pre-calcination ceramic package 60 is formed. Although the wall ceramic layer 60 b and seat ceramic layer 60 c are not shown in FIG. 5(D) , printing is performed at the blind via-holes 19 of the bottom ceramic layer 60 a during application of vacuum suction. Thus, the external terminals 15 are formed by screen printing of a conductive paste including tungsten, molybdenum, or the like. The screen printing is not performed to the entire blind via-holes 19 . Rather, the conductive paste is applied only in the central portions of the blind via-holes 19 to form the grooves 13 . Although not specifically described, this screen-printing technique is also performed to the copper plating 12 of the wall ceramic layer 60 b and to the seat ceramic layer 60 c.
The stacked structure formed as described above is calcinated for a predetermined time at approximately 1500° C. to form the ceramic package 60 having the grooves 13 .
In the foregoing description, screen printing is performed after cutting along the parting lines 69 . However, the ceramic package 60 may be produced by a process having a different other than that described above. For example, screen printing of the conductive paste may be performed to the large green sheet 60 a before partition. Then the sheet is calcinated and cut along the parting lines 69 .
The foregoing description pertained to the package 60 being made of ceramic. Alternatively, the package can be made of a filled resin, with the same grooves 13 being formed around the external terminals 15 . Exemplary filled-resin materials are epoxy resin, bismaleimide-triazine (BT) resin, polyimide resin, glass epoxy resin, glass BT resin, and the like. With a resin package, the groove 13 may be formed by laser processing, drilling, routing, or the like.
In the foregoing description, the first green sheet 60 a 1 and the second green sheet 60 a 2 are stacked to form the bottom ceramic layer 60 a . Alternatively, a boss, die, or the like defining a shape complementary to the shape of the groove 13 may be urged against a single green sheet to form the grooves 13 .
Depth Profiles of Grooves
As explained above, the grooves 13 extend depthwise into the base board and can be formed by laser processing, drilling, routing, or the like to a base board made of a resin laminate. Alternatively, the grooves 13 can be formed by punching or similar method before calcining a ceramic base board.
FIGS. 6A-6D show representative sectional profiles of the grooves 13 . In FIGS. 1 to 5 described above, the sectional profile of the grooves 13 was rectangular. But, any of various other sectional profiles can alternatively be used. FIG. 6A depicts a triangular profile for the grooves 13 . Such a profile can be formed easily by drilling or routing. However, if the width and the depth of a triangular-profiled groove 13 are the same as a corresponding rectangular groove, the volume of the triangular groove is less than of the rectangular groove. Hence, the triangular groove can accept less overflowing solder SOL than a rectangular groove having the same depth and width.
FIG. 6B shows a groove 13 having a sectional profile that is semi-circular. This profile is suitable if the grooves are formed by embossing.
FIG. 6C shows a groove 13 that provides progressively larger cross-sectional area with increased depth. Although special routing or the like must be used to form such grooves, since the volume of the groove 13 increases with depth, the amount of overflowing solder SOL that can be accommodated in such a groove may be larger than with other types of grooves.
FIG. 6D shows rectangular grooves 13 formed with shoulders (i.e., the grooves are separated from the external terminals 15 by a distance ΔL).
The grooves 13 described above are formed directly at the sides of the external terminals 15 . However, the grooves need not be formed directly to the sides.
The grooves 13 described above formed as a single groove around each respective external terminal 15 . Alternatively, multiple grooves (e.g., two) can be formed around the terminals.
The foregoing description has been in the context of mounting an electronic device, such as piezoelectric oscillator 100 or crystal oscillator 150 , to a circuit board PB. This is not intended to be limiting. The principles described herein can be applied to other types of electronic devices, such as a package having Chip on Board (COB) structure, and Pin Grid Array (PGA) structure, or a Ball Grid Array (BGA) package. These various electronic devices are often manufactured using resin packages. Since a resin package has rich mechanical processability, grooves may be formed economically and with high precision using mechanical techniques such as drilling or routing.
The description has been in the context of crystal oscillators. Alternatively, a crystal unit may be used and, in particular, a large-sized device is preferable among electronic devices. Before applying the solder SOL, a solder resist may be applied to the circuit board PB between places where the solder SOL is to be applied. | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to a method for fabricating a semiconductor device and, more particularly, to an improvement in element isolation techniques of an LSI (large scale integrated circuit).
As an isolation technique of a semiconductor integrated circuit, a technique for facilitating higher packaging density and for facilitating a manufacturing process therefor is known wherein an isolation region comprises an oxide film which is formed by the selective oxidation technique. According to this method, an active region is surrounded by an oxide film, so that self-alignment is possible in base diffusion or the like, and a part required for mask alignment in the conventional method is unnecesary. For this reason, high packaging density in some degree may be achieved. However, with this method, since a thermally oxidized film is selectively buried in a silicon substrate, the substrate is distorted to a considerable extent. This degrades the electrical characteristics of the element and imposes strict limits on the structure, configuration, film thickness and selective oxidation conditions of the antioxidant mask and even the selection of the material for the substrate. This is discussed in various literature such as IEDM "High Pressure Oxidation for Isolation of High Speed Bipolar Devices", 1979, pp. 340 to 343.
In the conventional element isolation technique utilizing insulators, the field oxidation time is long, which adversely affects the diffusion and redistribution of impurities in the channel stopper. For example, when the diffusion in the transverse direction is too great, the effective channel width of the MOS transistor is reduced and the drain junction capacitance increases. This presents a big problem for achieving a high speed device.
Furthermore, since the antioxidant mask comprises a bi-layered structure consisting of a silicon nitride film and an oxide film, a bird's beak undercuts the silicon nitride film to a depth of 1 μm or more. Therefore, formation of an element isolation film of less than 2 μm width has been difficult. This is discussed, for example, in J.E.C.S., "Bird's Beak Configuration and Elimination of Gate Oxide Thinning Produced during Selection Oxidation", 1980, pp. 216 to 222.
In order to overcome the defects of the element isolation technique utilizing selective oxidation, Japanese Laid-Open Patent application No. 50-11792 discloses a method according to which a mask is formed on a semiconductor substrate, a groove of a predetermined depth is formed by etching the substrate, an insulating film is formed by the CVD process to such a thickness that the groove is filled, and the mask is removed by etching or the like to simultaneously remove the insulating film on the mask, thereby leaving the insulating film only in the groove to provide an element isolation layer. This method has various advantages. Since the processing may be performed at a relatively low temperature, the substrate may not be adversely affected (the distortion due to high temperatures may be avoided), the bird's beak is not formed and transverse diffusion of the impurity layer as the channel stopper may be prevented. However, as shown in FIG. 1, an insulating film 3 as an element isolation layer in a groove 2 formed on a semiconductor substrate 1 cannot be formed completely flat, and gaps 4 are often formed between the insulating film 3 and the side walls of the groove 2.
The gaps 4 not only impair the element isolation function of the insulating film 3 but also impose problems in the subsequent steps for formation of the semiconductor element.
SUMMARY OF THE INVENTION
The present invention has been made in consideration of this and has for its object to provide a method for fabricating a semiconductor device which overcomes the drawbacks of the conventional method involving the selective oxidation method, which prevents the formation of gaps between the element region and the field region as in Japanese Laid-Open Patent application No. 50-11792, and which is capable of substantially completely flattening the element region and the field region.
In order to achieve this object, there is provided according to the present invention a method for fabricating a semiconductor device comprising the steps of:
(a) forming a pattern of a masking material on a semiconductor substrate, and forming a groove in said semiconductor substrate by using the patterned masking material as a mask;
(b) forming a first insulating film in said groove;
(c) forming a second insulating film on the surface of said semiconductor substrate including said groove; and
(d) forming an element isolation region substantially in said groove by removing a surface layer of said second insulating film.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a finished shape of a semiconductor element isolating layer manufactured according to a conventional method;
FIGS. 2A to 2G are sectional views showing steps in sequential order according to an embodiment of the method of the present invention;
FIGS. 3A to 3D are sectional views showing another embodiment of the method of the present invention; and
FIGS. 4 to 9 are sectional views showing various modifications of the method of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiment of the present invention will be described with reference to the case wherein it is applied to the manufacture of an n-channel MOS LSI. It should be noted however that this invention is also applicable to various kinds of semiconductor devices such as bipolar transistor, p-channel MOS, CMOS and etc.
(i) A masking material 12 such as a resist film (for example 1.5 μm in thickness) is deposited on a monocrystalline silicon semiconductor substrate (p-type, 10 Ω.cm in specific resistance) 11 and patterned by photolithography or the like. Using the resist film 12 as a mask, etching is performed to form grooves 13 for example, 3 μm in width, 1 μm in depth (FIG. 2A).
In this case, it is possible to employ as the masking material Al film, silicon nitride film, or a bi-layered film consisting for example of SiO 2 and polycrystalline silicon. It is also possible as an etching method of the groove 13 to adopt a reactive ion etching or a conventional taper etching method.
(ii) Using the masking material 12 as a mask, an impurity (e.g., boron) for preventing field inversion is implanted by, for example, ion implantation (accelerated voltage of 80 KeV, dosage of 5×10 12 cm -2 ) to form a field channel stopper region 14 (FIG. 2B). The implantation of the impurity may be carried out after the following step (iii). Depending on conditions such as the initial impurity concentration of the substrate or the like, the implantation of the impurity is not always required and may therefore be omitted.
(iii) A first insulating film 15, 1 μm in thickness for example (e.g., Al 2 O 3 film, SiO 2 film or the like) is formed by a conventional method such as chemical vapor deposition method or evaporation method (FIG. 2C).
(iv) The masking material 12 is etched away with, for example, a mixed solution of H 2 SO 4 and H 2 O 2 to remove the first insulating film 15, leaving it substantially only in the grooves 13. As a result, as shown in FIG. 2D, a gap "a" (for example, 1 μm in depth, 1 μm in width at the uppermost portion of the gap) is formed between the insulating film 15 and each wall of the groove 13.
(v) A second insulating film comprising for example of a low melting point insulator 16 (e.g., boron phospho-silicate glass (BPSG)) 1 to 2 μm in thickness is formed on the entire surface of the semiconductor substrate 11 including the groove 13. The low melting point insulator 16 is then melted to fill in the gap "a" (FIG. 2E).
It is possible to employ instead of the low melting point insulator, other insulating materials such as polyimide, a spin-coated SiO 2 , CVD SiO 2 or a resist material as a second insulating material. In the case of p-channel MOS LSI, phospho-silicate glass (PSG), arsenic silicate glass (AsSG) or the like may preferably be employed as a second insulating film.
It is also possible to employ as a second insulating film the same material as that of a first insulating film 15.
(vi) The entire layer of the low melting point insulator 16 is eteched until the upper surface of the semiconductor substrate 11 is exposed (FIG. 2F). As a result, it is possible to obtain in a simple process a semiconductor device provided with a flat field region (in general, insulative isolation region) having the insulating film 15 and the low melting point insulator 16 buried therein and with an element region whose top surface is flush with that of the field region.
(vii) A gate oxide film 17 and a gate electrode 18 are formed. Then, an n + -type layer 19 is formed as a source or drain. An interlayer insulating film 20 is deposited in which is formed a contact hole 21. An Al wiring layer 22 is then formed to complete the main steps for completing an LSI (FIG. 2G).
In step (iii) above, the first insulating film 15 of Al 2 O 3 , SiO 2 or the like is deposited. However, the present invention is not limited to this. For example, an oxidizable material layer may alternatively be formed and oxidized to provide a first insulating film. More specifically, as shown in FIG. 3A, a film 15' may be formed of a material which has a faster oxidizing rate than the silicon substrate 11 (e.g., aluminum which can be oxidized faster than the silicon substrate by anodic oxidation, or porous silicon which can be oxidized faster than the silicon substrate by thermal oxidation). Then, as shown in FIG. 3B, the resist film 12 is etched away to remove the film 15' formed thereon and to leave the film 15' in the groove 13.
Oxidation is performed such that the film 15' buried in the groove 13 oxidizes faster than the substrate 11 (e.g., by anodic oxidation if the film 15' is an Al film, and by thermal oxidation if the film 15' is a porous silicon film) to convert the film 15' to an oxide films 15" (an Al 2 O 3 , alumina film if the film 15" is an Al film and an SiO 2 film if the film 15" is a porous silicon film). During this step, a thin oxide film 23 is also formed on the substrate 11 (FIG. 3C). Since the oxidizing rate of the substrate 11 is smaller than that of the film 15', the part of the substrate 11 contiguous with the film 15' is not oxidized much, so that transverse undercutting of the field oxide film (formation of the bird's beak) does not occur.
The thin oxide film 23 is etched to expose the substrate 11 and to leave the oxide film 15" only in the groove 13 (FIG. 3D).
Steps (v) to (vii) are followed without alteration thereafter.
In step (iii) described above, the film 15 is an insulator film of Al 2 O 3 or the like. However, the low melting point insulator as used in step (v) may also be used.
The masking material may be other than the resist film 12 and may, for example as shown in FIG. 4, comprise a bi-layered structure consisting of an SiO 2 film 25 and a polycrystalline silicon film 26. In this case, in order to remove the film 15 on the masking material, the polycrystalline silicon film 26 may be etched, leaving the SiO 2 film 25.
Before depositing the film 15, a thin insulator film or a thin oxide film (for example, 1,000 Å in thickness) may be formed in the groove 13.
The film 15 may comprise a bi-layered structure of two different materials.
It is also possible to form, below the resist film 12, an antioxidant film, such as an Si 3 N 4 film. This Si 3 N 4 film may be used as a mask during the field oxidation of the film 15 so as to prevent oxidation of the substrate 11.
For filling the low melting point insulator into the gap "a" in step (v) described above, an alternative step as shown in FIG. 5A may be performed. First, an insulating layer 16' (for example, 5,000 Å in thickness) containing an impurity such as boron is deposited. Then, a low melting point insulating layer 16" (for example, 1 to 2 μm in thickness) is deposited. These two layers are heated at a temperature of for example 1,000° C. for 40 minutes to form a p + -type layer 27 (channel stopper region) by diffusion on both walls of the groove 13 as shown in FIG. 5B. The entire surface of the structure is subjected to etching to leave the insulating layers 16' and 16" or to leave only the insulating layer 16' (in this case the insulating layer 16' should be deposited relatively thick for instance, 1 μm) in the groove 13.
The diffusion of an impurity to form the p + -type layer 27 may be carried out not necessarily at the melting step of the insulating layers 16' and 16", but at any subsequent heating step. The formation of the p + -type layer 27 on each side of the gap "a" may also be conducted by a conventional ion implantation method.
In step (ii), it is also possible to use the resist film 12 as a mask to ion-implant arsenic or phosphorus to form an n + -type wiring layer 28 (a p + -type wiring layer if the ion-implanted impurity is of p-type conductivity) below the field region (FIG. 6).
Before depositing the insulating layer in step (iii) described above, it is also possible to deposit a conductive layer 29 of a refractory metal such as molybdenum, silicide, polycrystalline silicon or the like, to deposit the insulating layer 15 thereover, and to treat the structure according to the steps after the etching of the resist film to provide a structure which includes the conductive layer below the field region (FIG. 7).
The semiconductor substrate is not limited to that described above but may be a substrate of a p-type silicon substrate, an n-type silicon substrate, or a substrate of a compound such as GaAs, with a monocrystalline semiconductor layer formed thereover by the epitaxial growing method. The semiconductor substrate may be a monocrystalline insulator substrate such as a sapphire substrate or a spinel substrate, with a monocrystalline semiconductor layer formed thereover. Steps (i) to (vii) described above may be adopted without alteration for forming the element isolation region in this case. FIG. 8 shows the case wherein a substrate of composite structure as described above is used. FIG. 8 corresponds to FIG. 2 except that a monocrystalline semiconductor layer 31 is deposited on a first substrate 30 of a compound such as GaAs, p-type silicon, n-type silicon or an insulator such as sapphire. The rest of the configuration in FIG. 8 is the same as shown in FIG. 2, and the same reference numerals denote the same parts and the description thereof will be omitted.
In the embodiment shown in FIGS. 2D and 2E, the low melting point insulator 16 was directly buried in the gap "a". However, the present invention is not limited to this. As shown in FIG. 9, after step (iii), it is also possible to sufficiently fill an insulator 32 such as Al 2 O 3 , SiO 2 , or the like in the gap "a" by the CVD process and then to fill the gap "a" with the low melting point insulator 16 as in step (iv) described above.
In the above embodiments, the insulating layers 16, 16' and 16" are made flush with the surface of the substrate 11 by means of etching. However, such a flattening step can also be carried out physically by means of abrasion, e.g., after the deposition of Al 2 O 3 , SiO 2 and the like.
The embodiment of the present invention has been described with reference to an n-channel structure. However, the present invention is similarly applicable to a p-channel structure. However, it is also possible to use the phosphorus- or arsenic-doped polycrystalline silicon for the film 15 to be deposited over the n-type silicon substrate and to oxidize the film 15 by the wet oxidation (especially when the temperature is 900° C. or lower, the difference in the oxidizing rates of the n-type polycrystalline silicon and the silicon substrate becomes greater.)
In summary, the method of the present invention has various advantages to be described below:
(1) Since the substrate 11 is not oxidized much during the formation of the field oxide film, the bird's beak does not form and the field region of finer pattern may be formed.
(2) The heating period required for the field oxidation may be shortened. When the anodic oxidation is adopted, the heating step is not required in the field oxidation, so that the transverse diffusion of the field channel stopper region 14 may be suppressed to the minimum. If the groove 13 is formed deeper to form a deeper field channel stopper region 14, the channel stopper region 14 may not extend into the element region even if the heat treatment in the field oxidation or in the subsequent steps is prolonged to a certain extent.
(3) Since a recess or gap is not formed between the insulating film 15 or 15" constituting the field region and the side walls of the groove 13, the element isolation layers of excellent characteristics may be formed with a good yield. Furthermore, since the element region and the field region may be flattened, the subsequent photolithography step for forming a fine pattern may be facilitated. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to the toy field and more particularly, to a spring powered prime mover which is capable of providing a driving force for toys, such as toy vehicles.
2. Description of the Prior Art
Numerous forms of spring powered prime movers have been used in the toy industry to drive toy vehicles. Every child is familiar with a spring driven toy vehicle. Frequently, the spring drive is powered by a key which stores energy by tightening a spring band into a tensioned coiled condition. Usually, a series of gears alone or in combination with a flywheel are utilized to transmit the released stored energy from the spring into rotational motion for the driving of wheels on the toy vehicle.
As can be readily appreciated, the economics of the toy business require the spring motor to be relatively inexpensive. In this regard, the toy industry has utilized a spring and is affixed to an opening in a metal housing wall. Generally, the housing wall is made of a soft metal having tabs that can be bent to form a rectangular housing configuration. A gear train is appropriately mounted within the housing wall to drive an output shaft. Usually, when the spring is mounted, it must be cut with notches to fit within an aperture in the housing wall. These notches provide a weak point in the spring and frequently permit the fracturing of the spring and release from its anchoring position upon overtensioning by accident.
The toy industry is further seeking to miniaturize toy vehicles to enhance the play value for children and incidentally reduce material cost. Problems occur in providing durable and operative gear transmissions with reduced sizes, especially in molded material.
With the general increase in labor cost around the world, the prior art is still seeking new and improved low cost miniature spring wound prime movers that are equal to or superior to the prior art devices heretofore used. Additionally, the prior art is further seeking to provide a prime mover that can be economically assembled with a minimum of labor.
SUMMARY OF THE INVENTION
The present invention comprises a spring wound prime mover that is capable of driving toys and the like. A housing member is provided and supports an output shaft rotatably mounted to the housing member. The housing member is divided into a pair of shell members that can be interconnected with respective locking pawls and catches at alternative ends of each individual shell members. A cavity in a wall of one shell member has appropriate notches or recesses to co-act with an outer circumferential portion of the spring member for anchoring the same to the shell member. The spring member can be inserted into the recessed cavity without any requirement of alignment and provides a positive and easily assembled anchoring configuration. The other end of the spring member is designed to be moved for use in storing and releasing energy ultimately to an output shaft. A synthetic resin gear train assembly is connected to the spring member and to the output shaft and is capable of providing both a relatively high and a relatively low gear ratio. The gear train assembly can include a first gear that is movably mounted to be automatically forced into engagement when energy is being stored in the spring member. For example, the output shaft can be driven by an external force and the first gear can be engaged to provide a high gear ratio for moving the spring member to store energy. The first gear is automatically forced out of engagement when the spring member drives the output shaft. A second gear is also movably mounted to be automatically forced into engagement when the spring member drives the output shaft to provide a low gear ratio and conversely, is automatically forced out of engagement when the output shaft is driven by an external force for moving the spring member to store energy.
Preferably the modulus of elasticity of the individual gears are varied, for example, by mixing carbon fibers in nylon plastic so that a modulus of 0.3 is provided in the winding gear group and a modulus of 0.25 in the driving gear group. This arrangement provides sufficient mechanical strength to the gear teeth to ensure a high life cycle while assuring a smooth running transmission of the spring energy to the rear axle.
The features of the present invention, which are believed to be novel, are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially phantomed perspective view of a prime mover mounted in a toy vehicle;
FIG. 2 is an exploded perspective view of the prime mover;
FIG. 3 is a side schematic cross-sectional view of the gear train arrangement, and
FIG. 4 is a top plan view of the prime mover housing shells.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The following description is provided to enable any person skilled in the toy field to make and use the invention and sets forth the best modes contemplated by the inventor for carrying out his invention. Various modifications, however, will remain readily apparent to those skilled in the toy field, since the generic principles of the present invention have been defined herein specifically to provide a relatively economical and easily manufactured spring wound prime mover for use as a spring motor for toys.
Referring to FIG. 1, a partially phantomed perspective view of a toy vehicle incorporating the spring wound prime mover of the present invention is disclosed. The exterior configuration of the housing is preferably made of a plastic material such as polyethylene, nylon, etc., possessing a slight degree of resiliency. A pair of rear wheels are mounted on an output shaft. The exterior configuration of the housing member can be further provided with fastening ears, recesses, tabs, etc. (not shown), to facilitate a snap mounting within the body of the vehicle. When viewing the vehicle from the front with the prime mover appropriately mounted, the housing member comprises a right-hand side shell 15, an intermediate plate 16, and a left-hand side shell 14. The intermediate plate 16 provides gear bearing holes and cam surfaces and physically divides the gear train assembly.
Shell 14 is molded from plastic material and includes a recessed circuitous cavity within a holding drum 18. The periphery of the cavity includes a plurality of notches or recessed portions 17 as can be seen in FIG. 2. A bearing hole (not shown) is centered within the cavity and is designed to receive an axle or a shaft 8 of a large dual gear member. An oblong bearing hole 10 provides a camming surface for a movable combination gear, to be subsequently described. An additional bearing hole is also provided to rotatably receive another gear shaft. Mounting posts 19 and 20 can be integrally molded with the housing shell 14 and are designed to extend through respective friction fitting holes 21 and 22 in the intermediate plate 16, and holes 21' and 22' in the other shell member 15. Another bearing hole 28 is designed to rotatably receive the output shaft 1 which extends through the corresponding bearing hole 29 in the housing shell 14.
Intermediate plate 16 includes an oblong bearing hole 10' that is complementarily positioned relative to the bearing hole 10 for movably supporting a gear. Another oblong bearing hole 4 having a camming surface corresponds to a complementary oblong bearing hole 4' positioned in housing shell 15. Intermediate plate 16 also has an aperture for supporting the shaft of the large dual gear member. Finally, housing shell 15 includes bearing holes 30 and 31 for supporting the shafts of gears.
A spring member 7 has an outer peripheral end bent back upon itself to form a configuration that is complementary to the recessed portion 17 of the housing shell 14. When the spring member 7 expands, it is capable of locking its end in any one of the recessed portions 17. The inner end of the spring member 7 is also bent back upon itself to form an approximately circular loop. This circular loop is configured to interact with a gear shaft that is concentrically located within an integral collar member as can be best seen in FIG. 2. A portion of the spring member extends through an opening slot with the inner end thereby locked against any relative movement to provide the second anchor point for the spring member. Relative rotation of one anchor point to the other anchor point will permit the storage or release of spring energy.
The gear train assembly of FIGS. 2 and 3 includes a drive pinion 2 mounted on the output shaft 1. This drive pinion 2 is fixedly mounted to mesh with a spur gear 3 that is integrally molded with a second pinion gear 12 mounted on the same axle. A movable idle gear 5 is mounted within the oblong cam bearing holes 10' and 10 of the intermediate plate and the housing shell 14. When rotating in a counterclockwise direction on the right-hand side of intermediate plate 16, the idle gear 5 engages pinion gear 6 which is fixedly mounted in housing shell 14 and the bearing hole 30 of housing shell 15 to transmit energy ultimately to the spring member 7. The pinion gear 6 is integrally molded with large gear 9. A dual gear assembly including a pinion gear 11 and a spur gear 13 can be integrally molded with appropriately extending shafts for mounting within the oblong bearing holes 10' and 10 of respectively intermediate plate 16 and housing shell 14.
When the axle 1 is rotated by the rear wheels to store energy in spring 7, the small drive pinion gear 2 engages and rotates the spur gear 3. Rotation of the spur gear 3 automatically forces the gear 5 to travel along its camming slot 4' to engage and rotate the pinion gear 6. The pinion gear 6 is connected by the shaft 8 to the inner end of the spring member 7 and rotates the same to store energy. During this wind-up mode of operation, the large gear 9 rotates in a counterclockwise direction and automatically disengages the spur gear 13 as the pinion gear 11 is driven upward to the furtherest extent of the arcuate oblong bearing holes 10 and 10'.
When the gear train assembly is in a drive configuration, the spring member 7 is releasing stored energy by rotating shaft 8 and correspondingly the large gear 9. The large gear 9 drives the pinion gear 11 in a clockwise direction to automatically engage spur gear 13 with a second pinion gear 12. Since the second pinion gear 12 is directly connected to the spur gear 3, it rotates at the same speed to drive the pinion gear 2 on the output shaft 1. As can be appreciated, the rotation of the spur gear 3 forces the idle gear 5 to the end of the bearing holes 10 and 10' and thus, automatically out of engagement with the pinion gear 6.
As can be appreciated, gears 5 and 6 are employed in a first gear ratio for the storage of spring energy, and gears 9, 11, 12 and 13 are employed in a second gear ratio for the release of energy during translation of the vehicle across a support surface. Gears 2 and 3 are common to both power trains.
Consistent with the necessity to integrally mold dual gear arrangements, it is desirable in the present invention to try and vary the modulus of elasticity of the gear material by adding carbon-filled fibers, e.g. about 15 percent by volume so that the nylon gears involved in storing energy will have a modulus of about 0.3, while the nylon gears involved in driving the rear wheels will have a modulus of about 0.25. This variation of the modulus of elasticity is desirable to ensure high mechanical strength and smooth interfacing of the gear teeth.
Referring now to FIGS. 2 and 4, the respective housing shells 15 and 14, along with intermediate plate 16 are disclosed. To facilitate rapid assembly, the housing shell 15 is provided with a pair of flexible cantilevered locking prongs or pawls 23 and 24 that are dimensioned to be complementarily to catch edges or keepers 26 and 27. The enlarged locking heads of the locking prongs include camming surfaces. A spacing post 25 simply ensures that intermediate plate 16 is firmly seated between the respective housing shells 14 and 15. As can be seen in the perspective view of FIG. 2, the edges of intermediate plate 16 are appropriately notched to accommodate the passage of locking pawls 23 and 24. Thus, during assembly, housing shell 15 can be simply snap fitted onto housing shell 14. There is no necessity to use any fasteners or screws.
Throughout the present specification, the term "vehicle" has been utilized. However, it should be readily understood that the prime mover is capable of use on numerous small toys to provide a propulsion force. To appreciate the relative size of the motor that we are referring to, its dimensions can be less than one inch by one-half inch.
As can be readily appreciated, the gear ratios can be subjectively changed by varying the size of the gears. In operation, the child simply grasps the body of the vehicle and moves it backward for three or four inches to tension the spring member 7. Release of the vehicle will then drive it forward for a considerable distance at a relatively rapid velocity.
Modifications of the present invention could be easily accomplished by a person of ordinary skill once given the generic principles of the present invention, accordingly, the scope and spirit of the present invention should be determined only from the following claims: | 4y
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2005-0034726, filed on Apr. 26, 2005, the entire content of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a battery sheath and rechargeable battery using the same. More particularly, the invention relates to a battery sheath having enhanced mechanical strength, excellent workability and reduced thickness.
BACKGROUND OF THE INVENTION
[0003] As is generally known in the art, rechargeable batteries, for example lithium polymer batteries, include electrode assemblies, each of which typically includes a separator positioned between positive and negative electrode collectors. The separator acts as an electrolyte, serving as a medium for ion conduction. The separator also serves as a medium for separation, a function similar to their role in lithium ion batteries. The separator includes a gel-type polymer electrolyte, which is manufactured by impregnating a polymer with an electrolyte, thereby improving ion conductivity.
[0004] Unlike lithium ion batteries, lithium polymer batteries can have plate structures and do not require winding process. Therefore, the electrode assembly in a lithium polymer battery can include a number of plates laminated together and can have a square shaped structure. In addition, the electrolyte in a lithium polymer battery is injected into a completely integrated cell, and rarely leaks. Also, the plate structure of the lithium polymer battery makes it unnecessary to apply pressure when making the square shaped structure. Therefore, a thin flexible pouch may be used as the battery sheath, instead of a hard square or cylindrical can.
[0005] When a flexible pouch is used as the battery sheath, the thickness of the battery is substantially less than that of a can, enabling more electrode assemblies to be formed within the same volume allowing an increase in battery capacity. The flexible battery sheath allows the battery to take a desired shape and enables the easy mounting of the battery on various electronic appliances.
[0006] However, although pouch-type battery sheaths have increased battery capacity and can be processed into various shapes, they have low mechanical strength and are very vulnerable to external impact. For example, a hole can be easily formed in the battery sheath when the battery sheath is pierced by a sharp object (e.g., a needle or nail), and the sheath can be easily torn if, for example, it is bitten by a pet. Furthermore, when a sharp object penetrates the sheath and contacts the internal electrode assembly, a short circuit can occur between the positive and negative electrode collectors, and may cause the battery to catch fire or explode.
[0007] In addition, lithium polymer batteries using such a sheath can swell severely at high temperatures. Because the sheath surrounding the electrode assembly is flexible and has a low mechanical strength, the thickness and shape of the battery are easily deformed by gas generated from the internal polymer electrolyte.
SUMMARY OF THE INVENTION
[0008] In accordance with one embodiment of the present invention a battery sheath having a ferrite stainless steel (SUS) layer is provided. The battery sheath has enough mechanical strength to stably protect the battery from external impact. The battery sheath having a ferrite SUS layer also suppresses the battery swelling phenomenon, preventing deformation of the thickness and shape of the battery.
[0009] According to another embodiment of the present invention, a battery sheath having a ferrite SUS layer has a reduced thickness and increased mechanical strength, thereby improving battery capacity.
[0010] According to another embodiment of the present invention, a battery sheath having a ferrite SUS layer has excellent workability so that there is no blowout or no rupture when forming a cavity for containing an electrode assembly.
[0011] One exemplary battery sheath includes a ferrite SUS layer having a first surface and a second surface. A first insulation layer such as a cast polypropylene (CPP) layer is then attached to the first surface of the ferrite SUS layer. A second insulation layer such as a nylon layer or a polyethylene terephthalate (PET) layer is attached to the second surface of ferrite SUS layer.
[0012] In other embodiments, the present invention is directed to rechargeable batteries using the battery sheaths. A rechargeable battery may include an electrode assembly having at least one positive electrode collector, at least one negative electrode collector, and at least one separator between the positive and negative electrode collectors. The battery further includes positive and negative electrode tabs coupled to the electrode assembly and extended with a predetermined length from the positive and negative electrode collectors. A sheath includes a first region having a cavity with a predetermined depth for containing the electrode assembly, and a second region adapted to cover the cavity of first region.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 is a perspective view of a battery sheath before formation of a cavity, according to one embodiment of the present invention.
[0014] FIG. 2 is a cross-sectional view of a battery sheath taken along line 1 - 1 in FIG. 1 .
[0015] FIG. 3 a is a perspective view of a battery sheath having a cavity for containing an electrode assembly according to one embodiment of the present invention.
[0016] FIG. 3 b is a magnified view of the region 3 b of FIG. 3 a.
[0017] FIG. 4 is a perspective view of a rechargeable battery according to one embodiment of the present invention.
[0018] FIG. 5 is a cross-sectional view of the rechargeable battery taken along line 4 - 4 in FIG. 4 .
DETAILED DESCRIPTION
[0019] Referring to FIGS. 1 and 2 , a battery sheath 10 includes a ferrite SUS layer 11 , a first insulation layer 12 formed on a surface of the ferrite SUS layer 11 and a second insulation layer 13 formed on the other surface of the ferrite SUS layer 11 .
[0020] The ferrite SUS layer 11 has an approximately planar or a completely planar first surface 11 a and an approximately planar or a completely planar second surface 11 b opposite the first surface 11 a . In addition, the thickness of the ferrite SUS layer 11 between the first and second surfaces 11 a , 11 b ranges from about 10 μm to about 60 μm, which is less than the thickness of prior art sheaths by several microns to tens of microns. Namely, since the ferrite SUS layer 11 has increased mechanical strength because of the material characteristics, it may have more reduced thickness than that of the prior art sheaths. Furthermore, the ferrite SUS layer 11 doesn't need to increase the thickness in order to enhance the elongation ratio related to workability because of the material characteristics. The ferrite SUS layer 11 , therefore, may not only reduce the thickness thereof but also keep up the high mechanical strength. For a comparative reference, in the case of using an austenite SUS layer, it needs to increase its thickness in order to enhance the elongation ratio, thus it is difficult for its thickness to stay less than 60 μm. Therefore, in accordance with the present invention more electrode assemblies (not shown) can be contained within the same volume. That is, the capacity of the battery increases.
[0021] The ferrite SUS layer 11 may include an alloy having from about 84% to about 88.2% iron, about 0.5% or less carbon, from about 11% to about 18% chromium, and from about 0.3% to about 0.5% manganese. Furthermore, the ferrite SUS layer 11 may include a material selected from the group consisting of Korean Industrial Standard (KS) STS430 and Japanese Industrial Standard (JIS) SUS430. However, it is understood that any suitable material may be used for the ferrite SUS layer 11 . Since the ferrite SUS layer has high mechanical strength and high resistance to chemical corrosion, it increases the mechanical strength of the battery sheath 10 and increases the resistance to the electrolyte. The ferrite SUS layer 11 , of course, prevents moisture from penetrating the battery. The ferrite SUS layer 11 has an elongation ratio of about 10% to about 60%, enabling easy formation of a cavity (not shown). This elongation ratio prevents the ferrite SUS layer 11 from being damaged during formation of the cavity. The cavity is formed to a predetermined depth by a die, and contains the electrode assembly. For example, the ferrite SUS layer 11 may be annealed in an inactive gas atmosphere at a temperature of hundreds of degrees Celsius to maintain the elongation ratio at about 10% to about 60%. Of course, since the ferrite SUS layer 11 has excellent workability, it has high elongation ratio by itself and there may be no need to be annealing.
[0022] Furthermore, the characteristics of the ferrite SUS layer 11 enable suppression of swelling which may occur at higher temperatures after battery assembly. Therefore, deformation of the thickness and shape of the battery is sufficiently prevented. More particularly, massive gas may be generated by decomposition of the electrolyte at high temperature after assembling the battery. And then, the swelling phenomenon, wherein the battery sheath swells outwardly, may occur because of the massive gas. However, since the battery sheath in accordance with the present invention uses the ferrite SUS layer 11 having high mechanical strength, the swelling phenomenon is sufficiently prevented from deforming the battery.
[0023] The first insulation layer 12 which is applied to the first surface 11 a of the ferrite SUS layer 11 may be a CPP layer. A CPP layer with a thickness of about 30 μm to about 40 μm may be applied to the first surface 11 a of the ferrite SUS layer 11 . The CPP layer may have a thickness slightly greater than that of the ferrite SUS layer 11 because the CPP layer directly contacts to the electrode assembly and is thermally bonded to each other.
[0024] The second insulation layer 13 which is applied to the second surface 11 b of the ferrite SUS layer 11 may be one selected from a nylon layer and a PET layer. For example, the nylon layer or the PET layer is applied to the second surface 11 b of the ferrite SUS layer 11 by lamination at high temperature. The nylon or the PET layer with a thickness of about 5 μm to about 10 μm is applied to the second surface 11 b . The PET layer as the second insulation layer 13 may include an alloy film. More particularly, the PET layer may further include rubber particles for enhancing resistance to impact, a solubilizer surrounding the rubber particles for enhancing adherence, and an adhesive. The rubber particles increase the elongation ratio and the resistance to impact. The solubilizer improves adherence to the ferrite SUS layer 11 , and particularly to the second surface 11 b of the ferrite SUS layer 11 . The adhesive, previously applied to the PET layer enables direct lamination of the PET layer at high temperature without applying any special adhesive to the ferrite SUS layer 11 . This further simplifies the manufacturing process of the battery sheath 10 . The PET layer may not include an adhesive. In that case, an adhesive is previously formed on the second surface 11 b of the ferrite SUS layer 11 . The PET layer is then applied to the ferrite SUS layer 11 .
[0025] FIG. 3 a is a perspective view of a battery sheath 110 according to one embodiment of the present invention. The sheath 110 includes a cavity 116 for containing an electrode assembly. FIG. 3 b is a magnified view of region 3 b in FIG. 3 a . Referring to FIGS. 3 a and 3 b , the battery sheath 110 includes a first region 117 a and a second region 117 b which are folded together such that their edges are thermally bonded. The first region 117 a may include a cavity 116 having a predetermined width and depth for containing an electrode assembly (not shown). The electrode assembly includes at least one positive electrode collector, at least one negative electrode collector and at least one separator between the positive and negative electrode collectors. The second region 117 b may also include a cavity (not shown). A ferrite SUS layer 111 , which is the main material of the sheath 110 , has an elongation ratio of about 10% to about 60% for preventing the sheath 110 from being damaged during formation of the cavity 116 .
[0026] The thickness of the first layer 112 is greater than the thickness of the ferrite SUS layer 111 , and the thickness of the ferrite SUS layer 111 is greater than the thickness of a second insulation layer 113 , such as a PET layer. The first insulation layer 112 is the thickest because the portion of the first insulation layer 112 on the outer peripheral edges of the first and second regions 117 a , 117 b , respectively, are thermally bonded to each other.
[0027] FIG. 4 is a perspective view of a rechargeable battery 200 according to another embodiment of the present invention. FIG. 5 is a cross-sectional view of the rechargeable battery taken along line 4 - 4 in FIG. 5 . As shown, the rechargeable battery 200 includes an electrode assembly 221 , a sheath 210 , and a protective circuit module 223 .
[0028] The electrode assembly 221 is formed by laminating at least one positive electrode collector 221 a , at least one negative electrode collector 221 b , and at least one separator 221 c between the positive and negative electrode collectors 221 a , 221 b , respectively. The positive electrode collector 221 a includes lithium cobalt oxide (LiCoLO 2 ) on aluminum (Al) foil. The negative electrode collector 221 b includes graphite on copper (Cu) foil. The separator 221 c includes a gel-type polymer electrolyte. At least one positive electrode tab 222 a of aluminum is bonded to the aluminum foil of the positive electrode collector 221 a , and at least one negative electrode tab 222 b of nickel is bonded to the copper foil of the negative electrode collector 221 b . The positive and negative electrode tabs 222 a , 222 b extend a predetermined length from the exterior of the sheath 210 .
[0029] The sheath 210 includes a first region 217 a having a cavity 216 of a predetermined depth for containing the electrode assembly 221 , and a second region 217 b for covering the cavity 216 of the first region 217 a.
[0030] The sheath 210 includes a ferrite SUS layer 211 . A first insulation layer 212 , such as a CPP layer, is applied to a surface of the ferrite SUS layer 211 and a second insulation layer 213 , such as a PET layer, is laminated at high temperature on the other surface of the ferrite SUS layer 211 . An adhesive (not shown) may optionally be applied between the ferrite SUS layer 211 and the first insulation layer 212 . The other adhesive (not shown) may also be optionally applied between the ferrite SUS layer 211 and the second insulation layer 213 . The first insulation layer 212 surrounds the electrode assembly 221 , and the second insulation layer 213 is positioned on the outermost surface of the sheath 210 . The first insulation layers 211 on the outer peripheral edges 217 c of the first and second regions 217 a , 217 b , respectively, of the sheath 210 , are thermally bonded to each other and can be folded such that the volume of the sheath 210 is minimized. The remaining features of the sheath 210 are similar to those described above with reference to FIGS. 1 through 3 b.
[0031] The protective circuit module 223 is attached to a front side of the sheath 210 to protect the battery 200 from voltage or current generated during overcharging or over-discharging. The protective circuit module 223 is electrically connected to the positive and negative electrode tabs 222 a , 222 b , respectively.
[0032] As shown in FIG. 5 , the positive electrode 221 a is positioned on the outer surface of the electrode assembly 221 . Therefore, although the first insulation layer 212 is formed so that the positive electrode 221 a contacts the ferrite SUS layer 211 , the ferrite SUS layer isn't corroded. Namely, since the ionization tendency of the positive electrode 221 a is greater than that of the ferrite SUS layer 211 , the positive electrode may be corroded but the ferrite SUS layer 211 is not corroded. Therefore, the electrolyte doesn't leak through the ferrite SUS layer 211 .
[0033] As described above, the battery sheath includes a ferrite SUS layer having high mechanical strength such that the sheath stably protects the battery from external impact. The high mechanical strength of the sheath enables to have a reduced battery thickness and an increased volume of the electrode assembly. This increases battery capacity. The high mechanical strength of the sheath also suppresses a swelling phenomenon and prevents a deformation of the thickness and shape of the battery. The excellent workability of the battery sheath makes it possible to easily form the cavity for containing the electrode assembly. The high resistance to chemical corrosion of the battery sheath enables the battery to stably prevent from the resistance to the electrolyte and an external acid solution.
[0034] Exemplary embodiments of the present invention have been described for illustrative purposes. However, those skilled in the art will appreciate that various modifications, additions and substitutions may be made to the described embodiments without departing from the scope and spirit of the invention as disclosed in the accompanying claims. | 4y
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This application is a continuation of U.S. application Ser. No. 10/165,204, filed Jun. 6, 2002, now abandoned, the contents of which are hereby incorporated herein by reference, which is a continuation in part of International Application Ser. No. PCT/GB00/04673, filed Dec. 7, 2000, which International Application was published by the International Bureau in English as WO 01/41679 on Jun. 14, 2001.
FIELD OF THE INVENTION
The present invention relates to medical implants, particularly cardiac and vascular implants and prostheses. More specifically, the invention relates to a cardiac valve prosthesis comprising a frame and leaflets. Such valves may also be made without rigid frames and may also be used as valves in artificial hearts, whether the latter are intended for permanent implantation or for temporary support of a patient.
BACKGROUND OF THE INVENTION
In mammals the heart is the organ responsible for maintaining an adequate supply of blood, and hence of oxygen and nutrients, to all parts of the body. Reverse flow of blood through the heart is prevented by four valves which serve as the inlet and outlet of each of the two ventricles, the pumping chambers of the heart.
Dysfunction of one or more of these valves can have serious medical consequences. Such dysfunction may result from congenital defects, or from disease induced damage. Forms of dysfunction include stenosis (reduction in the orifice of the open valve) and regurgitation (reverse flow through the closing or closed valve), either of which increases the work required by the heart to maintain the appropriate blood flows to the body.
In many cases the only effective solution is to replace the malfunctioning valve. A valve replacement operation is expensive and requires specialised facilities for open heart surgery. Replacement of failed artificial heart valves carries increased risk over the initial replacement, so there are practical limits on the number of times reoperation can be undertaken. Consequently, the design and materials of an artificial valve must provide for durability of the valve in the patient. The artificial valve must also operate without high pressure gradients or undue reverse flow during closing or when closed, because these are the very reasons for which a replacement of the natural valve is undertaken.
Mechanical valves, which use a ball or a disc or a pair of pivoting rigid leaflets as the opening member(s) can meet these combined requirements of hemodynamic performance and durability. Unfortunately, a patient who has had a mechanical valve implanted must be treated with anticoagulants, otherwise blood will clot on the valve. Clotting on the valve can either restrict the movement of the valve opening member(s), impairing valve function, or can break free from the valve and obstruct blood vessels downstream from the valve, or both. A patient receiving a mechanical valve will be treated with anticoagulants for life.
Valves excised from pigs and treated with glutaraldehyde to crosslink and stabilise the tissue are also used for replacement of defective valves. These may be mounted on a more or less rigid frame, to facilitate implantation, or they may be unmounted and sewn by the surgeon directly to the vessel walls at operation. A further type of valve replacement is constructed from natural tissue, such as pericardium, treated with glutaraldehyde and mounted on a frame. Valves from pigs or made from other animal or human tissue are collectively known as tissue valves. A major advantage of tissue valves over mechanical valves is that they are much less likely to provoke the blood to clot, and so patients receiving tissue valves are not normally given anticoagulants other than during the immediate post operative period. Unfortunately, tissue valves deteriorate over time, often as a result of calcification of the crosslinked natural tissue. This deterioration presents a problem, particularly in young patients. Thus, although the recipient of a tissue valve is not required to take anticoagulants, the durability of tissue valves is less than that of mechanical valves.
In third world countries, where rheumatic fever is still common, the problems of valve replacement in young patients are considerable. Anticoagulants, required for mechanical valves, are impractical and accelerated calcification of tissue valves precludes their use.
In the Western world, life expectancy continues to increase, and this results in a corresponding rise both in patients requiring cardiac valve replacement, and in those patients needing replacement of deteriorating artificial valves implanted in the past. There is, therefore, a need for a replacement heart valve with good hemodynamics, extended durability and having sufficiently low risk of inducing clotting so that anticoagulants are not necessary.
The natural heart valves use thin flexible tissue leaflets as the closing members. The leaflets move readily out of the orifice as blood begins to flow through the valve so that flow through the open valve is unrestricted by the leaflets. Tissue valves function similarly, providing a relatively unrestricted orifice when the valve is open. For mechanical valves, on the other hand, the closing member rotates in the orifice, but is not removed from the orifice when the valve opens. This provides some restriction to flow, but more importantly, disturbs the blood flow patterns. This disturbance to the flow is widely held to initiate, or at least to contribute significantly to, the observed tendency of mechanical valves to produce clotting.
A number of trileaflet polyurethane valve designs have been described.
A valve design, comprising a leaflet geometry which was elliptical in the radial direction and hyperbolic in the circumferential direction in the closed valve position, with leaflets dip-coated from non-biostable polyurethane solutions onto injection-molded polyurethane frames has attained durabilities in excess of 800 million cycles during in vitro fatigue testing (Mackay T G, Wheatley D J, Bernacca G M, Hindle C S, Fisher A C. New polyurethane heart valve prosthesis: design, manufacture and evaluation. Biomaterials 1996; 17:1857-1863; Mackay T G, Bernacca G M, Wheatley D J, Fisher A C, Hindle C S. In vitro function and durability assessment of a polyurethane heart valve prosthesis. Artificial Organs 1996; 20:1017-1025; Bernacca G M, Mackay T G, Wheatley D J. In vitro function and durability of a polyurethane heart valve: material considerations. J Heart Valve Dis 1996; 5:538-542; Bernacca G M, Mackay T G, Wilkinson R, Wheatley D J. Polyurethane heart valves: fatigue failure, calcification and polyurethane structure. J Biomed Mater Res 1997; 34:371-379; Bernacca G M, Mackay T G, Gulbransen M J, Donn A W, Wheatley D J. Polyurethane heart valve durability: effects of leaflet thickness. Int J Artif Organs 1997; 20:327-331.). However, this valve design became unacceptably stenotic in small sizes. Thus, a redesign was effected, changing the hyperbolic angle from the free edge to the leaflet base, and replacing the injection-molded frame with a rigid, high modulus polymer frame. This redesign permitted the use of a thinner frame, thus increasing valve orifice area. This valve design, with a non-biostable polyurethane leaflet material, was implanted in a growing sheep model. Valve performance was good over the six month implant period, but the region close to the frame posts on the inflow side of the valve, at which full leaflet opening was not achieved, suffered a local accumulation of thrombus (Bernacca G M, Raco L, Mackay T G, Wheatley D J. Durability and function of a polyurethane heart valve after six months in vivo. Presented at the XII World Congress of International Society for Artificial Organs and XXVI Congress of the European Society for Artificial Organs, Edinburgh, August 1999. Wheatley D J, Raco L, Bernacca G M, Sim I, Belcher P R, Boyd J S. Polyurethane: material for the next generation of heart valve prostheses? Eur. J. Cardio-Thorac. Surg. 2000; 17; 440-448). This valve design used non-biostable polyurethane, which had tolerable mechanical durability, but which showed signs of polymer degradation after six months in vivo.
International Patent Application WO 98/32400 entitled “Heart Valve Prosthesis” discloses a similar design, i.e., closed leaflet geometry, comprising essentially a trileaflet valve with leaflets molded in a geometry derived from a sphere towards the free edge and a cone towards the base of the leaflets. The spherical surface, defined by its radius, is intended to provide a tight seal when the leaflets are under back pressure, with ready opening provided by the conical segment, defined by its half-angle, at the base of the leaflets. Were the spherical portion located at the leaflet base it is stated that this would provide an advantage in terms of the stress distribution when the valve is closed and under back pressure.
U.S. Pat. No. 5,376,113 (Jansen et al.) entitled “Closing Member Having Flexible Closing Elements, Especially a Heart Valve” issued Dec. 27, 1994 to Jansen et al. discloses a method of producing flexible heart valve leaflets using leaflets attached to a base ring with posts extending from this upon which the leaflets are mounted. The leaflets are formed with the base ring in an expanded position, being effectively of planar sheets of polymer, which become flaccid on contraction of the ring. The resulting valve is able to maintain both a stable open and a stable closed position in the absence of any pulsatile pressure, though in the neutral unloaded position the valve leaflets contain bending stresses. As a consequence of manufacturing the valve from substantially planar sheets, the included angle between the leaflets at the free edge where they attach to the frame is 60° for a three leaflet valve.
U.S. Pat. No. 5,500,016 (Fisher) entitled “Artificial Heart Valve” discloses a valve having a leaflet shape defined by the mathematical equation z 2 +y 2 =2RL (x−g)−α(x−g) 2 , where g is the offset of the leaflet from the frame, RL is the radius of curvature of the leaflet at (g,0,0) and α is the shape parameter and is >0 and <1.
A valve design having a partially open configuration when the valve is not subject to a pressure gradient, but assuming a fully-open position during forward flow is disclosed in International Patent Application WO 97/41808 entitled “Method for Producing Heart Valves”. The valve may be a polyurethane trileaflet valve and is contained within a cylindrical outer sleeve.
U.S. Pat. Nos. 4,222,126 (Boretos et al.) and 4,265,694 (Boretos et al.) disclose a trileaflet polyurethane valve with integral polyurethane elastomeric leaflets having their leading edges reinforced with an integral band of polymer and the leaflets reinforced radially with thicker lines of polyurethane.
The problem of chronic thrombus formation and tissue overgrowth arising from the suture ring of valves has been addressed by extension of the valve body on either side of the suture ring as disclosed in U.S. Pat. No. 4,888,009 (Lederman et al.) entitled “Prosthetic Heart Valve”.
Current polyurethane valve designs have a number of potential drawbacks. Close coaptation of leaflets, while ensuring good valve closure, limits the wash-out of blood during hemodynamic function, particularly in the regions close to the stent posts at the commissures. This region of stagnation is likely to encourage local thrombogenesis, with further restriction of the valve orifice in the longer term as well as increasing the risk of material embolising into the circulation. Associated with the thrombosis may be material degradation (in non-biostable polyurethanes) and calcification resulting in localised stiffening the leaflets, stress concentrations and leaflet failure. As previously discussed, animal implants of a trileaflet polyurethane valve design have indicated that thrombus does tend to collect in this region, restricting the valve orifice and damaging the structure of the valve.
Present valve designs are limited by the availability of suitable polyurethanes which possess good mechanical properties as well as sufficient durability to anticipate clinical functionality of up to twenty years or more. Many low modulus materials, which provide good hydrodynamic function, fail during fatigue testing at unacceptably low durations, due to their greater susceptibility to the effects of accumulated strain. Higher modulus polyurethanes may be better able to withstand repeated stress without accumulating significant damage, but are too stiff to provide good hydrodynamic function in conventional almost-closed geometry valve designs. Current design strategies have not been directed towards enabling the incorporation of potentially more durable, higher modulus leaflet materials, nor the creation of a valve design that is able to maintain good hydrodynamic function with low modulus polyurethanes manufactured as thick leaflets.
The nature of the valve leaflet attachment to the frame is such that, in many valve designs, there is a region of leaflet close to the frame, which is restrained by the frame. This region may extend some distance into the leaflet before it interfaces with the free-moving part of the leaflet, or may be directly at the interface between frame and leaflet. There thus exists a stress concentration between the area of leaflet that is relatively mobile, undergoing transition between fully open and fully closed, and the relatively stationary commissural region. The magnitude of this flexural stress concentration is maximized when the design parameters predicate high bending strains in order for the leaflet to achieve its fully open position.
U.S. Pat. Nos. 4,222,126 (Boretos et al.) and 4,265,694 (Boretos et al.) disclose a valve which uses thickened leaflet areas to strengthen vulnerable area of the leaflets. However this approach is likely to increase the flexure stress and be disadvantageous in terms of leaflet hydrodynamic function.
The major difficulties which arise in designing synthetic leaflet heart valves can be explained as follows. The materials from which the natural trileaflet heart valves (aortic and pulmonary) are formed have deformation characteristics particularly suited to the function of such a valve. Specifically, they have a very low initial modulus, and so they are very flexible in bending, which occurs at low strain. This low modulus also allows the leaflet to deform when the valve is closed and loaded in such a way that the stresses generated at the attachment of the leaflets, the commissures, are reduced. The leaflet material then stiffens substantially, and this allows the valve to sustain the closed loads without prolapse. Synthetic materials with these mechanical properties are not available.
Polyurethanes can be synthesized with good blood handling and good durability. They are available with a wide range of mechanical properties, although none has as low a modulus as the natural heart valve material. Although they show an increase in modulus at higher strains, this does not occur until strains much higher than those encountered in leaflet heart valves.
Polyurethanes have been the materials of choice for synthetic leaflet heart valves in the last decade or more. More recently, polyurethanes have become available which are resistant to degradation when implanted. They are clearly more suitable for making synthetic leaflet heart valves than non-stable polyurethanes, but their use suffers from the same limitations resulting from their mechanical properties. Therefore, design changes must be sought which enable synthetic trileaflet heart valves to function with the best available materials.
Key performance parameters which must be considered when designing a synthetic leaflet heart valve include pressure gradient, regurgitation, blood handling, and durability.
To minimize the gradient across the open valve, the leaflets must open wide to the maximum orifice possible, which is defined by the inside diameter of the stent. This means that there must be adequate material in the leaflets so they can be flexed into a tube of diameter equal to the stent internal diameter. In addition, there has to be a low energy path for this bending because the pressure forces available to open the valve are small, and the lower the gradient, the smaller the pressure becomes. All the leaflets must open for the lowest cardiac output likely to be encountered by that valve in clinical service.
To minimize closing regurgitation (reverse flow lost through the closing valve) the valve leaflets must be produced at or close to the closed position of the valve. To minimize closed valve regurgitation (reverse flow through the valve once it has closed), the apposition of the leaflets in the commissural region is found to be key, and from this perspective the commissures should be formed in the closed position.
Proper blood handling means minimising the activation both of the coagulation system and of platelets. The material of construction of the valve is clearly a very important factor, but flow through the valve must also avoid exposing blood either to regions of high shear (velocity gradient) or to regions of relative stasis. Avoiding regions of high shear is achieved if the valve opens fully, and relative stasis is avoided if the leaflet/frame attachment and the commissural region in particular opens wide. This is not achieved with typical synthetic materials when the commissures are molded almost closed, because the stiffness of synthetics is too high.
Durability depends to a large extent on the material of construction of the valve leaflets, but for any given material, lifetime will be maximized if regions of high stress are avoided. The loads on the closed valve are significantly greater than loads generated during valve opening. Therefore, the focus should be on the closed position. Stresses are highest in the region of the commissures where loads are transmitted to the stent, but they are reduced when the belly of the leaflet is as low as practicable in the closed valve. This means that there must be sufficient material in the leaflet to allow the desired low closing.
SUMMARY OF THE INVENTION
The present invention provides a cardiac valve prosthesis comprising a frame and two or more leaflets (preferably three) attached to the frame. Two embodiments of the invention are disclosed.
1. First Embodiment
The leaflets are attached to the frame between posts, with a free edge which can seal the leaflets together when the valve is closed under back pressure. The leaflets are created in a mathematically defined shape allowing good wash-out of the whole leaflet orifice, including the area close to the frame posts, thereby relieving the problem of thrombus deposition under clinical implant conditions.
The leaflet shape has a second design feature, by which the pressure required to open the valve and the pressure gradient across the valve in the open position is reduced by creating a valve which is partially open in its stable unstressed position. Molding the leaflets in a partially open position permits them to open easily to a wider angle resulting in an increased effective orifice area, for any given polyurethane/elastomeric material. This permits the use of materials from a wider range of mechanical properties to fabricate the leaflets, including those of a relatively stiff nature, and also permits lower modulus materials to be incorporated as thicker and hence more durable leaflets, while retaining acceptable leaflet hydrodynamic function.
A third design feature is the reduction of a stress concentration in the vicinity of the commissural region of the leaflets. In many valve designs, there exists a region of localised high bending where the opening part of the flexible leaflet merges into the stationary region of the leaflet adjacent to the valve frame. The current design reduces the bending, and hence the local stress concentration, in this region. This feature is designed to enhance the valve durability.
The wide opening of the leaflet coaptation close to the stent posts improves blood washout, reduces thrombogenesis and minimizes embolic risks to the recipient, by allowing a clear channel for blood flow throughout the whole valve orifice.
The partially open design acts to reduce the fluid pressure required to open the valve. This in turn results in lower pressure gradients across the valve, allowing the use of durable, stiffer polyurethanes to fabricate the valve which may be better equipped to deal with a cyclic stress application or thicker leaflets of lower modulus polyurethanes, hence achieving good durability with good hydrodynamic function. The position of the leaflet in its stable unstressed state acts to reduce the stress concentration resulting from leaflet bending, hence increasing valve durability.
In one aspect the invention is a cardiac valve prosthesis comprising a frame defining a blood flow axis and at least two leaflets attached to the frame. The at least two leaflets are configured to be movable from an open to a closed position. The leaflets have a blood inlet side and a blood outlet side and are in the closed position when fluid pressure is applied to the outlet side, and in the open position when fluid pressure is applied to the inlet side. The leaflets are in a neutral position intermediate the open and closed position in the absence of fluid pressure being applied to the leaflets. The at least two leaflets include a first leaflet. The first leaflet has a surface contour such that an intersection of the first leaflet with at least one plane perpendicular to the blood flow axis forms a first composite wave. The first composite wave is substantially defined by a first wave combined with at least a second wave superimposed over the first wave. The first wave has a first frequency and the second wave has a second frequency, different from the first frequency. Alternatively, the first composite wave may be defined by a first wave combined with second and third waves superimposed over the first wave. The third wave has a third frequency which is different from the first frequency.
Both the first wave and the second wave may be symmetric or asymmetric about a plane parallel to and intersecting the blood flow axis and bisecting the first leaflet. The first composite wave may be symmetric or asymmetric about a plane parallel to and intersecting the blood flow axis and bisecting the first leaflet. The at least two leaflets may include second and third leaflets. An intersection of the second and third leaflets with a plane perpendicular to the blood flow axis forms second and third composite waves. The second and third composite waves are substantially the same as the first composite wave. The first and second waves may be defined by an equation which is trigonometric, elliptical, hyperbolic, parabolic, circular, a smooth analytic function or a table of values. The at least two leaflets may be configured such that they are substantially free of bending stresses when in the neutral position. The frame may be substantially cylindrical having first and second ends, one of the ends defining at least two scalloped edge portions separated by at least two posts, each post having a tip, and wherein each leaflet has a fixed edge joined to a respective scalloped edge portion of the frame and a free edge extending substantially between the tips of two posts. The first and second waves may be symmetric about a plane parallel to and intersecting the blood flow axis and bisecting the first leaflet or at least one of the first and second waves may be symmetric about such plane. The first leaflet may have a surface contour such that when the first leaflet is in the neutral position an intersection of the first leaflet with a plane parallel to and intersecting the blood flow axis and bisecting the first leaflet forms a fourth wave.
In another aspect the invention is a method of making a cardiac valve prosthesis. The valve prosthesis includes a frame defining a blood flow axis substantially parallel to the flow of blood through the valve prosthesis and at least two flexible leaflets attached to the frame. The method includes providing a forming element having at least two leaflet forming surfaces. The forming element is engaged with the frame. A coating is applied over the frame and engaged forming element. The coating binds to the frame. The coating over the leaflet forming surfaces forms the at least two leaflets. The at least two leaflets are configured to be movable from an open to a closed position. The leaflets have a blood inlet side and a blood outlet side and are in the closed position when fluid pressure is applied to the outlet side, and in the open position when fluid pressure is applied to the inlet side. The leaflets are in a neutral position intermediate the open and closed position in the absence of fluid pressure being applied to the leaflets. The at least two leaflets include a first leaflet. The first leaflet has a surface contour such that the intersection of the first leaflet with at least one plane perpendicular to the blood flow axis forms a first composite wave. The first composite wave is substantially defined by a first wave combined with a second superimposed wave. The first wave has a first frequency and the second wave has a second frequency different from the first frequency. After the coating is applied the forming element is disengaged from the frame. The first composite wave formed in the coating step may be defined by a first wave combined with second and third waves superimposed over the first wave. The third wave has a third frequency which is different from the first frequency.
The first and second waves formed in the coating step may be either symmetric or asymmetric about a plane parallel to and intersecting the blood flow axis and bisecting the first leaflet. The first composite wave formed in the coating step may be symmetric or asymmetric about a plane parallel to and intersecting the blood flow axis and bisecting the first leaflet. The at least two leaflets formed in the coating step may include second and third leaflets. An intersection of the second and third leaflets with a plane perpendicular to the blood flow axis forms second and third composite waves, respectively. The second and third composite waves are substantially the same as the first composite wave. The first and second waves formed in the coating step may be defined by an equation which is trigonometric, elliptical, hyperbolic, parabolic, circular, a smooth analytic function or a table of values.
The first and second waves in the coating step may be symmetric about a plane parallel to and intersecting the blood flow axis and bisecting the first leaflet or at least one of the first and second waves may be asymmetric about such plane. The at least two leaflets in the coating step are configured such that they are substantially free of bending stresses when in the neutral position.
In a further aspect the invention is a cardiac valve prosthesis comprising a frame defining a blood flow axis and at least two leaflets attached to the frame including a first leaflet. The first leaflet has an internal surface facing the blood flow axis and an external surface facing away from the blood flow axis. The first leaflet is configured such that a mean thickness of a first half of the first leaflet is different than a mean thickness of a second half of the first leaflet. The first and second halves are defined by a plane parallel to and intersecting the blood flow axis and bisecting the first leaflet. The first leaflet may be further configured such that a thickness of the first leaflet between the internal and external surfaces along a cross section defined by the intersection of a plane perpendicular to the blood flow axis and the first leaflet changes gradually and substantially continuously from a first end of the cross section to a second end of the cross section.
In another aspect the invention is a method of making a cardiac valve prosthesis which includes a frame defining a blood flow axis substantially parallel to the flow of blood through the valve prosthesis and at least two flexible leaflets attached to the frame. The method includes providing a mold having a cavity sized to accommodate the frame, inserting the frame into the mold, inserting the mold into an injection molding machine, and injecting molten polymer into the cavity of the mold to form the at least two leaflets. The injection of the molten polymer causes the at least two leaflets to bond to the frame. The cavity is shaped to form the at least two leaflets in a desired configuration. The at least two leaflets are configured to be movable from an open to a closed position. The leaflets have a blood inlet side and a blood outlet side and are in the closed position when fluid pressure is applied to the outlet side, and in the open position when fluid pressure is applied to the inlet side. The leaflets are in a neutral position intermediate the open and closed position in the absence of fluid pressure being applied to the leaflets. The at least two leaflets include a first leaflet having a surface contour such that when the first leaflet is in the neutral position an intersection of the first leaflet with at least one plane perpendicular to the blood flow axis forms a first composite wave. The first composite wave is substantially defined by a first wave combined with at least a second superimposed wave. The first wave may have a first frequency, the second wave may have a second frequency, the first frequency being different from the second frequency.
In a still further aspect the invention is a method of designing a cardiac valve prosthesis which includes a frame and at least two flexible leaflets attached to the frame. The method includes defining a first desired shape of the leaflets in a first position, defining a second desired shape of the leaflets in a second position different from the first position, and conducting a draping analysis to identify values of adjustable parameters defining at least one of the first and second shapes. The draping analysis ensures that the leaflets are comprised of a sufficient amount and distribution of material for the leaflets to assume both the first and second desired shapes. Either of the first and second positions in the defining steps may be a closed position and the other of the first and second positions may be a partially open position.
2. Second Embodiment
In one aspect, this invention is a cardiac valve prosthesis comprising a substantially cylindrical frame defining a blood flow axis, the frame having first and second ends, one of the ends defining at least two scalloped edge positions separated by at least two posts, each post having a tip; and at least two flexible leaflets attached to the frame, the at least two leaflets being configured to be movable from an open to a closed position, the at least two leaflets having a blood inlet side and a blood outlet side, the at least two leaflets being in the closed position when fluid pressure is applied to the outlet side, being in the open position when fluid pressure is applied to the inlet side and being in a neutral position intermediate the open and closed position, in the absence of fluid pressure being applied to the leaflets, each leaflet having a fixed edge joined to a respective scalloped edge portion of the frame and a free edge extending substantially between the tips of two posts. The at least two leaflets may include a first leaflet having a surface contour such that when the first leaflet is in the neutral position an intersection of the first leaflet with at least one plane perpendicular to the blood flow axis forms a first composite wave, the first composite wave being substantially defined by a first wave combined with at least a second wave superimposed over the first wave, the first wave having a first frequency, the second wave having a second frequency different than the first frequency, the first wave comprising a circular arc.
The first wave may be defined by a first wave combined with second and third waves superimposed over the first wave, the third wave having a third frequency which is different from the first and second frequencies. The first composite wave as well as the second wave may be symmetric or asymmetric about a plane parallel to and intersecting the blood flow axis and bisecting the first leaflet. The at least two leaflets may further include second and third leaflets; and an intersection of the second and third leaflets with the plane perpendicular to the blood flow axis may form second and third composite waves, respectively, the second and third composite waves being substantially the same as the first composite wave. The second wave may be defined by an equation which is one of trigonometric, elliptical, hyperbolic, a smooth analytic function and a table of values. The at least two leaflets may be configured such that they are substantially free of bending stresses when in the neutral position. The first leaflet may have a surface contour such that when the first leaflet is in the neutral position an intersection of the first leaflet with a plane parallel to and intersecting the blood flow axis and bisecting the first leaflet forms a fourth wave.
In a second aspect, this invention is a method of making a cardiac valve prosthesis which includes a substantially cylindrical frame defining a blood flow axis substantially parallel to the flow of blood through the valve prosthesis and at least two flexible leaflets attached to the frame, the method comprising forming at least two scalloped edge portions on the frame, the shape of each scalloped edge portion being defined by the intersection of the frame with a plane inclined with respect to the blood flow axis; treating the frame to raise its surface energy to above about 64 mN/m; providing a forming element having at least two leaflet forming surfaces; engaging the forming element to the frame; applying a coating over the frame and engaged forming element, the coating binding to the frame, the coating over the leaflet forming surfaces forming the at least two flexible leaflets, the at least two leaflets being configured to be movable from an open to a closed position, the at least two leaflets having a blood inlet side and a blood outlet side, the at least two leaflets being in the closed position when fluid pressure is applied to the outlet side, being in the open position when fluid pressure is applied to the inlet side and being in a neutral position intermediate the open and closed position, in the absence of fluid pressure being applied to the leaflets, the at least two leaflets including a first leaflet having a surface contour such that when the first leaflet is in the neutral position an intersection of the first leaflet with at least one plane perpendicular to the blood flow axis forms a first composite wave, the first composite wave being substantially defined by a first wave combined with at least a second superimposed wave, the first wave having a first frequency, the second wave having a second frequency, the first frequency being different from the second frequency, the first wave comprising a circular arc; and disengaging the forming element from the frame.
DESCRIPTION OF DRAWINGS
FIG. 1 is a diagrammatic view comparing the shape of symmetric (solid line) and asymmetric (dashed line) leaflets.
FIG. 2 is a perspective view of the valve prosthesis in the neutral or partially open position.
FIG. 3 is a sectional view similar to the sectional view along line 3 - 3 of FIG. 2 except that FIG. 3 illustrates that view when the leaflets are in the closed position and illustrates the function which is used to define the shape of the closed leaflet belly X Closed (Z).
FIG. 4A is a front view of the valve leaflet shown in FIG. 2 . FIG. 4B is in the same view as FIG. 4A and is a partial schematic view of the same closed valve leaflet shown in FIG. 3 and illustrates that S(X,Y) n and S(X,Y) n-1 are contours enclosing the leaflet between the function X Closed (Z) and the scallop geometry.
FIG. 5 is a plot of an underlying function used in defining the valve leaflet in the molded leaflet partially open position P for valves made in accordance with the first embodiment.
FIG. 6 is a plot of a symmetrical superimposed function used in defining the shape of the valve leaflet of the first embodiment in the molded leaflet position P.
FIG. 7 is a plot of the composite function used in construction of the molded leaflet position P resulting from combining an underlying function ( FIG. 5 ) and a symmetric superimposed function ( FIG. 6 ) for valves made in accordance with the first embodiment.
FIG. 8 is a plot of an asymmetric superimposed function used in the construction of the molded leaflet position P for valves made in accordance with the first embodiment.
FIG. 9 is a plot of the composite function resulting from combining an underlying function ( FIG. 5 ) and an asymmetric function ( FIG. 8 ) for valves made in accordance with the first embodiment.
FIG. 10 is a sectional view of the valve leaflets in the neutral position along line 3 - 3 in FIG. 2 and illustrates the function which is used to define the shape of the molded leaflet belly X open (Z).
FIG. 11A is a front view of the valve. FIG. 11B is a partial schematic view of the valve leaflets of FIG. 11A and illustrates that P(X,Y) n and P(X,Y) n-1 are contours enclosing the leaflet between the function X open (Z) and the scallop geometry.
FIG. 12 is a perspective view of a valve of the first embodiment having symmetric leaflets.
FIG. 13 is a perspective view of a valve of the first embodiment having asymmetric leaflets.
FIG. 14 is a side view of a former used in the manufacture of the valve of the present invention.
FIG. 15 is a plot of an underlying function used in defining the valve leaflet in the molded partially open position P for a valve made in accordance with the second embodiment.
FIG. 16 is a plot of an asymmetrical superimposed function used in defining the shape of a valve leaflet of the second embodiment in the molded leaflet position P for valves made in accordance with the second embodiment.
FIG. 17 is a plot of the composite function used in construction of the molded leaflet position P resulting from combining an underlying function ( FIG. 15 ) and an asymmetric superimposed function ( FIG. 16 ) for a valve made in accordance with the second embodiment.
FIG. 18 is a perspective view of a valve of the second embodiment having asymmetric leaflets.
DESCRIPTION OF THE INVENTION
a. Design Considerations
Consideration of the factors discussed above results in the identification of certain design goals which are achieved by the prosthetic heart valve of the present invention. First, the prosthetic heart valve must have enough material in the leaflet for wide opening and low closing, but more than this amount increases the energy barrier to opening. To ensure that there is sufficient, but not an excess of material, a draping analysis discussed in more detail below is used. Second, to ensure sufficient material for wide opening and low closing, the valve can only be manufactured in a partially open position: (a) by deforming the stent posts outwards during manufacture; (b) by introducing multiple curves in the leaflet free edge (but see below); (c) by making the closed position asymmetric; and (d) combinations of the above. Third, if there is enough material for low closing and wide opening, the energy barrier to opening may be high enough to prevent opening of all leaflets at low flow. The energy barrier can be minimized by: (a) introducing multiple curves in the leaflet; (b) making the leaflet asymmetric; and combinations of the above. Fourth, open commissures are needed for blood handling and closed commissures are needed for regurgitation, so the valve should have partially open commissures. In particular the included angle between adjacent leaflet free edges at the valve commissures (for example see angle α of the symmetric leaflets shown in FIG. 1 ) should be in the range of 10-55°, preferably in the range 25-55°.
As discussed above, the use of multiple curves in the leaflet helps assure wide opening and more complete closure of the valve and to minimize the energy barrier to opening of the valve. However, the introduction of multiple curves of more than 1.5 wavelengths to the leaflet can be a disadvantage. While there may be sufficient material in the leaflet to allow full opening, in order for this to happen, the bends in the leaflet must straighten out completely. The energy available to do this arises only from the pressure gradient across the open valve, which decreases as the leaflets becomes more open, i.e., as the valve orifice area increases. This energy is relatively small (the more successful the valve design the smaller it becomes), and does not provide enough energy to remove leaflet curves of more than 1.5 wavelengths given the stiffness of the materials available for valve manufacture. The result is they do not straighten out and the valve does not open fully.
A draping analysis is used as a first approximation to full finite element analysis to determine if the starting shape of a membrane is such that it will take on a desired final shape when placed in its final position. From a durability standpoint the focus is on the closed position, and the desired shape of the leaflet in its closed position is defined. Draping analysis allows the leaflet to be reformed in a partially open position.
Draping analysis assumes that very low energy deformation is possible (in reality any form of deformation requires energy). In order for this to occur the bending stiffness of the leaflet/membrane must be small, each element of the membrane should be free to deform relative to its neighbour, and each element should be free to change shape, i.e., the shear modulus of the material is assumed to be very low. In applying the draping analysis, it is assumed that the leaflet can be moved readily from an original defined closed position to a new position in which it is manufactured. When the valve is actually cycled, it is assumed that the leaflet when closing will move from the manufactured position to the originally defined closed position. This allows the closed position to be optimised from a stress distribution aspect, and the manufactured position to be optimised from the point of view of reducing the energy barrier to opening.
Both symmetric and asymmetric shapes of the leaflet can allow incorporation of sufficient material in the leaflet free edge to allow full opening. FIG. 1 is a diagrammatic view comparing the shape of symmetric (solid line) and asymmetric (dashed line) leaflets and also showing the commissure area 12 where the leaflets connect to the frame. An advantage of the asymmetric shape is that a region of higher radius of curvature 14 is produced than is achieved with a symmetric curve having a lower radius of curvature 16 . This region can buckle more readily and thereby the energy barrier to opening is reduced.
An asymmetric leaflet also reduces the energy barrier through producing unstable buckling in the leaflet. During opening symmetric leaflets buckle symmetrically i.e., the leaflet buckles are generally mirrored about the centerline of the leaflet thus balancing the bending energies about this centerline. In the asymmetric valve the region of higher radius buckles readily, and because these bending energies are not balanced about the center line, this buckle proceeds to roll through the leaflet producing a sail-like motion producing a low energy path to open.
An additional feature of the asymmetric valve is that the open position is also slightly asymmetric, as a result of which it offers a somewhat helical flow path, and this can be matched to the natural helical sense of the aorta. Suggested benefits of this helical flow path include reduction of shear stress non-uniformity at the wall, and consequent reduction of platelet activation.
b. The Valve Prosthesis
First and second embodiments of the valve prosthesis will be described with reference to the accompanying drawings. FIG. 2 is a perspective view of a heart valve prosthesis made in accordance with the present invention. The valve 10 comprises a stent or frame 1 and attached leaflets 2 a , 2 b , and 2 c . The leaflets are joined to the frame at scallops 5 a , 5 b , and 5 c . Between each scallop is post 8 , the most down-stream part of which is known as a stent tip 6 . Leaflets 2 a , 2 b , and 2 c have free edges 3 a , 3 b , and 3 c , respectively. The areas between the leaflets at the stent tips 6 form commissures 4 .
1. First embodiment of heart valve prosthesis
The following describes a particular way of designing a first embodiment of a valve of the present invention. Other different design methodology could be utilized to design a valve having the structural features of the valve disclosed herein. Five computational steps are involved in this particular method:
(1) Define the scallop geometry (the scallop, 5 , is the intersection of the leaflet, 2 , with the frame, 1 ); (2) Geometrically define a valve leaflet in the closed position C; (3) Map and compute the distribution of area across the leaflet in the closed position; (4) Rebuild the leaflet in a partially open position P; and (5) Match the computed leaflet area distribution in the partially open or molded position P to the defined leaflet in the closed position C. This ensures that when an increasing closing pressure is applied to the leaflets, they eventually assume a shape which is equivalent to that defined in closed position C.
This approach allows the closed shape of the leaflets in position C to be optimised for durability while the leaflets shaped in the molded partially open shape P can be optimised for hemodynamics. This allows the use of stiffer leaflet materials for valves which have good hemodynamics. An XYZ co-ordinate system is defined as shown in FIG. 2 , with the Z axis in the flow direction of blood flowing through the valve.
The leaflets are mounted on the frame, the shape of which results from the intersection of the aforementioned leaflet shape and a 3-dimensional geometry that can be cylindrical, conical or spherical in nature. A scallop shape is defined through intersecting the surface enclosed by the following equations with a cylinder of radius R (where R is the internal radius of the valve):
X ell =E sO −E sJ .√{square root over (1−( Z/E sN ) 2 )}
H sJ =E sO −E sJ √{square root over ((1−( Z/E sN ) 2 ))}− H sO
H sN ( Z )= H sJ .tan(60).ƒ( Z )
where ƒ(Z) is a function changing with Z.
X hyp =H sO +H sJ √{square root over ((1−(Y/H sN ) 2 ))}
The shape of the scallop can be varied using the constants E s0 , E sJ , H s0 , ƒ(Z). The definition of parameters used in these and the other equations herein are contained in Table 4.
The shape of the leaflet under back pressure (i.e., in the closed position C) can be approximated mathematically using elliptical or hyperbolic co-ordinates, or a combination of the above in an XYZ co-ordinate system where XY is the plane of the valve perpendicular to the blood flow and Z is the direction parallel to the blood flow. The parameters are chosen to define approximately the shape of the leaflet under back pressure so as to allow convenient leaflet re-opening and minimize the effect of the stress component which acts in the direction parallel to the blood flow, whilst also producing an effective seal under back pressure.
The closed leaflet geometry in closed position C is chosen to minimize stress concentrations in the leaflet particularly prone to occur at the valve commissures. The specifications for this shape include:
(1) inclusion of sufficient material to allow a large open-leaflet orifice; (2) arrangement of this material to minimize redundancy (excess material in the free edge, 3 ) and twisting in the centre of the free edge, 3 ; and (3) arrangement of this material to ensure the free edge, 3 , is under low stress i.e., compelling the frame and leaflet belly to sustain the back-pressure.
FIG. 3 is a partial sectional view (using the section 3 - 3 shown in FIG. 2 ) showing only the intended position of the leaflet in the closed position. The shape of this intended position is represented by the function X Closed (Z). This function can be used to arrange the shape of the leaflet in the closed position C to meet the aforementioned specification. The curve is defined using the following equation and manipulated using the constants E cJ , E cO , Z cO and the functions E cN (Z) and X T (Z).
X Closed ( Z ) = - [ E cJ · ( 1 - ( Z - Z e O E c N ( Z ) ) 2 ) ] 0.5 + E cO - X T ( Z )
where E cN is a function changing linearly with Z and X T (Z) is a function changing nonlinearly with Z
Thus the scallop shape and the function X Closed (Z) are used to form the prominent boundaries for the closed leaflet in the closed position C. The remaining part of the leaflet is formed using contours S(X,Y) n sweeping from the scallop to the closed leaflet belly function X closed (Z), where n is an infinite number of contours, two of which are shown in FIG. 4B .
The length of the leaflet (or contours S(X,Y) n ) in the circumferential direction (XY) is calculated and repeated in the radial direction (Z) yielding a function L(Z) which is used later in the definition of the geometry in the partially open position P. The area contained between respective contours is also computed yielding a function K(Z) which is also used in the definition of the geometry in position P. The area contained between contours is approximated using the process of triangulation as shown in FIG. 4B . This entire process can be shortened by reducing the number of contours used to represent the surface (100<n<200).
The aforementioned processes essentially define the leaflet shape and can be manipulated to optimise for durability. In order to optimise for hemodynamics, the same leaflet is molded in a position P which is intermediate in terms of valve opening. This entails molding large radius curves into the leaflet which then serve to reduce the energy required to buckle the leaflet from the closed to the open position. The large radius curves can be arranged in many different ways. Some of these are outlined herein.
The leaflet may be molded on a dipping former as shown in FIG. 14 . Preferably the former is tapered with an included angle θ so that the end 29 has a diameter which is greater than the end 22 . (This ensures apposition of the frame and former during manufacture.) In this case, the scallop shape, defined earlier, is redefined to lie on a tapered geometry (as opposed to the cylindrical geometry used in the definition of the closed leaflet shape). This is achieved by moving each point on the scallop radially, and in the same movement, rotation of each point about an X-Y plane coincident with the bottom of the scallop, until each point lies on the tapered geometry.
The geometry of the leaflet shape can be defined as a trigonometric arrangement (or other mathematical function) preferably sinusoidal in nature in the XY plane, comprising one or more waves, and having anchoring points on the frame. Thus the valve leaflets are defined by combining at least two mathematical functions to produce composite waves, and by using these waves to enclose the leaflet surface with the aforementioned scallop.
One such possible manifestation is a composite curve consisting of an underlying low frequency sinusoidal wave upon which a second higher frequency sinusoidal wave is superimposed. A third wave having a frequency different from the first and second waves could also be superimposed over the resulting composite wave. This ensures a wider angle between adjacent leaflets in the region of the commissures when the valve is fully open thus ensuring good wash-out of this region.
The composite curve, and the resulting leaflet, can be either symmetric or asymmetric about a plane parallel to the blood flow direction and bisecting a line drawn between two stent tips such as, for leaflet 2 a , the section along line 3 - 3 of FIG. 2 . The asymmetry can be effected either by combining a symmetric underlying curve with an asymmetric superimposed curve or vice versa.
The following describes the use of a symmetric underlying function with an asymmetric superimposed function, but the use of an asymmetric underlying function will be obvious to one skilled in the art. The underlying function is defined in the XY plane and connects the leaflet attachment points to the scallop at a given height from the base of the valve. This underlying function shown in FIG. 5 , can be trigonometric, elliptical, hyperbolic, parabolic, circular, or other smooth analytic function or could be a table of values.
Using sine functions, one possible underlying wave is shown in FIG. 5 and is defined using the following equation.
X
u
=
X
(
n
,
0
)
+
A
u
·
sin
[
(
0.5
π
Y
(
n
,
0
)
)
·
(
Y
-
Y
(
n
,
0
)
)
]
The superimposed wave is defined in the XY plane, and connects the attachment points of the leaflet to the scallop at a given height above the base of the valve. The superimposed wave is of higher frequency than the underlying wave, and can be trigonometric, elliptic, hyperbolic, parabolic, circular, or other smooth analytic function, or a table of values.
Using sine functions, one possible symmetric leaflet design is formed when the underlying wave is combined with a superimposed wave formed using the following equation.
X
s
=
-
A
s
·
B
s
(
Y
)
·
sin
[
(
1.5
·
π
Y
(
n
,
0
)
)
·
(
Y
-
Y
(
n
,
0
)
)
]
A s can be varied across the leaflet to produce varying wave amplitude across the leaflet, for example lower amplitude at the commissures than in the leaflet centre. B s can be varied to adjust the length of the wave. The superimposed wave is shown in FIG. 6 . The composite wave formed by combining the underlying wave ( FIG. 5 ) with the superimposed wave ( FIG. 6 ) is shown in FIG. 7 .
Using sine functions, one possible asymmetric leaflet design is formed when the underlying wave ( FIG. 5 ) is combined with a superimposed wave formed using the following equation.
X
s
=
-
A
s
·
B
s
(
Y
)
·
sin
[
(
π
Y
(
n
,
0
)
)
·
(
Y
-
Y
(
n
,
0
)
)
]
0
Y
(
n
,
0
)
X
s
=
0.5
·
A
s
B
s
(
Y
)
·
sin
[
(
2.0
·
π
Y
(
n
,
0
)
)
·
Y
]
(
-
Y
(
n
,
0
)
)
0
A s can be varied across the leaflet to produce varying wave amplitude across the leaflet, for example lower amplitude at the commissures than in the leaflet centre. B s (Y) can be varied to adjust the length of the wave. The superimposed wave is shown in FIG. 8 . The resulting asymmetric composite wave is shown in FIG. 9 . The composite wave W(X c ,Y c ) n is created by offsetting the superimposed wave normal to the surface of the underlying wave ( FIGS. 7 , 9 ).
While the general shape of the leaflet in position P has been determined using the composite wave, at this stage it is not specified in any particular position. In order to specify the position of P, the shape of the partially open leaflet position can be defined as X open (Z). This is shown as reference numeral 7 in FIG. 10 .
One possible function determining this shape is given as follows:
X
open
(
Z
)
=
-
[
E
oJ
·
(
1
-
(
Z
-
Z
oO
E
oN
)
2
)
]
0.5
+
E
oO
In order to manipulate the composite wave to produce the belly shape X open (Z) the respective amplitudes of the individual sine waves can be varied from the free edge to the leaflet base. For example, the degree of ‘openness’ of the leaflet in position P can be varied throughout the leaflet.
The composite wave is thus defined to produce the molded “buckle” in the leaflet, and X open (Z) is used to define the geometry of the leaflet at position P. At this stage it may bear no relation to the closed leaflet shape in position C. In order to match the area distribution of both leaflet positions, (thus producing essentially the same leaflet in different positions) the composite wave length is iterated to match the length of the relevant leaflet contour in position C. Thus the amplitude and frequency of the individual waves can be varied in such a manner as to balance between: (a) producing a resultant wave the length of which is equal to the relevant value in the length function L(Z) thus approximating the required closed shape when back pressure is applied, and (b) allowing efficient orifice washout and ready leaflet opening. Also the area contained between the contours in the open leaflet is measured using the same process of triangulation as in the closed position C, and is iterated until it matches with the area contained between relevant contours in position C (denoted K(Z)) (through tilting the contours in P relative to each other). Thus the composite waves (P(X,Y) n ) pertaining to the contour n and length L(Z) can be tilted at an angle to the XY plane about attachment points X (n,0) . Y (n,0) and X (n,0), −Y (n,0) until the correct area is contained between P(X,Y) n and P(X,Y) n-1 (See FIGS. 10 & 11 ).
This process identifies the values of B S, A U and the contour tilt angle to be used in constructing the mold for the valve leaflet. As long as the constants such as B s and A u , and the tilt angle of the contours relative to the XY plane, are known, the surface of the leaflet in its molded position can be visualised, enclosed and machined in a conventional manner. As a result of this fitting process the composite wave retains the same basic form but changes in detail from the top of the leaflet to the bottom of the leaflet. A composite wave can be defined in the leaflet surface as the intersection of the leaflet surface with a plane normal to the Z axis. This composite wave will have the same general form as the composite wave used in the leaflet design but will differ from it in detail as a result of the tilting process described above.
In summary therefore one possible method of designing the leaflet of the first embodiment of the present invention is in the following way:
(1) Define a scallop shape; (2) Define a shape approximating the shape of the closed leaflet using elliptical, hyperbolic, parabolic or circular functions, smooth analytical functions or table of values; (3) Compute the functions L(Z) and K(Z), which define the length of the leaflet in the XY plane along the Z axis and the area distribution of the leaflet along the Z axis; (4) Use one or more associated sine waves to generate a geometry which is partially-open, which pertains to a leaflet position which is between the two extreme conditions of normal valve function, i.e., leaflet open and leaflet closed; (5) Vary the frequency and amplitude of the sinewaves to fit to the length function L(Z) and the angle at which the contour is tilted to the XY plane to fit to the area function K(Z); and (6) The respective amplitudes of the individual sine waves can be varied from the free edge to leaflet base, for example the degree of ‘openness’ of the leaflet can be varied throughout the leaflet.
Examples 1 and 2 set forth hereafter are examples of how the invention of the first embodiment can be put into practice. Using the scallop constants in Table 1, the constants required to produce an example of a symmetric leaflet valve (example 1, FIG. 12 ) and an example of an asymmetric leaflet valve (example 2, FIG. 13 ) are given in Table 2 and Table 3 respectively. These constants are used in conjunction with the aforementioned equations to define the leaflet geometry.
With one leaflet described using the aforementioned equations, the remaining two leaflets are generated by rotating the geometry about the Z axis through 120° and then through 240°. These leaflet shapes are inserted as the leaflet forming surfaces of the dipping mold (otherwise known as a dipping former), which then forms a 3-dimensional dipping mold. The composite wave described in the aforementioned equations, therefore substantially defines the former surface which produces the inner leaflet surface.
As seen in FIG. 14 the dipping mold 20 is slightly tapered so that the end 29 has a diameter which is greater than the end 22 , and has a first end 22 having an outside diameter slightly smaller than the inside diameter of the frame. The former includes at least two and preferably three leaflet forming surfaces 24 which are defined by scalloped edges 26 and flats 28 . Sharp edges in the manufacturing former and on the frame are radiused to help reduce stress concentrations in the finished valve. During the dip molding process the frame is inserted over end 22 of the former so that the scallops 5 and stent posts 8 of the frame align with the scalloped edges 26 and flats 28 of the former. The leaflet forming surfaces 24 are configured to form leaflets during the molding process which have the geometry described herein. This mold can be manufactured by various methods, such as, machining, electrical discharge machining, injection molding. In order that blood flow is not disturbed, a high surface finish on the dipping mold is essential.
For the frame there are preferably three posts with leaflets hung on the frame between the posts. A crown-like frame or stent, 1 , is manufactured with a scallop geometry, which matches the dipping mold scallop. The frame scallop is offset radially by 0.1 mm to allow for the entire frame to be coated with a thin layer of leaflet material to aid adhesion of the leaflets. Leaflets may be added to the frame by a dip-molding process, using a dipping former machined or molded to create the multiple sinewave form.
The material of preference should be a semi-rigid fatigue-and creep-resistant frame material such as polyetheretherketone (PEEK), high modulus polyurethane, titanium, reinforced polyurethane, or polyacetal (Delrin) produced by machining or injection-molding etc. Alternatively, a relatively low modulus polymer may be used, which may be fibre-reinforced, to more closely mimic the aortic wall. The frame can be machined or injection molded, and is manufactured preferably from PEEK or polyacetal (Delrin).
The frame is treated by exposure to a gas plasma or other methods to raise its surface energy above 64 mN/m (milliNewtons/meter). Then the frame is dipped in a polyurethane solution (preferably Elast-Eon™ manufactured by Aortech Biomaterials Pty, Sydney Australia) in order to apply a coating of approximately 0.1 mm thick. Having dried the frame with applied coating in an oven overnight, it is placed on the dipping former and aligned with the former scallops. The combination of frame and three dimensional dipping mold is then dipped into polyurethane solution, which forms a coating of solution on frame and mold. This coating flows slowly over the entire mold surface ensuring a smooth coating. The new coating on the frame and dipping mold solvates the initial frame coating thus ensuring a good bond between leaflet and frame. The dipping mold with polyurethane covering is dried in an oven until all the solvent has been removed. One or more dips may be used to achieve a leaflet with a mean thickness between 40 μm and 500 μm. The shape of the former, and the viscosity and solvent interactive properties of the polyurethane solution, control the leaflet thickness and the distribution of thickness over the leaflet. A dipping process does not allow precise control of leaflet thickness and its variation across a leaflet. In particular, surfaces that are convex on the dipping former result in reduced leaflet thickness when compared with surfaces that are concave. Additionally the region of the leaflet adjacent to the frame essentially provides a very small concave radius which traps further polymer solution and this results in thickening of these regions.
The shape of the former is substantially defined by the composite wave. Radiusing and polishing of the former can both contribute to some variation of the shape. The shape of the inner surface of the leaflets will closely replicate the shape of the former. The shape of the outer surface of the leaflets will be similar to the shape of the inner surface but variations will result from the processing properties of the polymer solution and details of the dipping process used to produce the valve. The leaflet may be formed from polyurethanes having a Young's modulus less than 100 MPa, preferably in the range 5 to 50 MPa.
The valve is next removed from the dipping mold. The stent posts, which had been deflected by the taper on the former, now recover their original position. The shape of the leaflets changes slightly as a result of the movement of the stent posts.
At this stage the dipping mold and frame is covered with an excess of polyurethane due to the drain-off of the polymer onto the region of the mold known as the drain-off area 30 . Leaflet free edges may be trimmed of excess material using a sharp blade rotated around the opened leaflets or using laser-cutting technology.
An alternate valve manufacturing method is injection molding. A mold is constructed with a cavity which allows the valve frame to be inserted in the mold. The cavity is also designed with the leaflet geometry, as defined above, as the inner leaflet surface. A desired thickness distribution is defined for the leaflet and the outer leaflet surface of the mold is constructed by adding the leaflet thickness normally to the inner leaflet surface. The leaflet may be of uniform thickness throughout, in the range 40 to 500 microns, preferably 50 to 200 microns, more preferably 80 to 150 microns. The leaflet may be thickened towards its attachment to the frame. Alternatively the thickness of the leaflet, along a cross-section defined by the intersection of a plane perpendicular to the blood flow axis and the leaflet, can change gradually and substantially continuously from a first end of the cross-section (i.e., first edge of the leaflet) to a second end of the cross-section (i.e., second edge of the leaflet) in such a way that the mean thickness of the first half of the leaflet is different from the mean thickness of the second half of the leaflet. This mold is inserted in a conventional injection molding machine, the frame is inserted in the mold and the machine injects molten polymer into the cavity to form the leaflets and bond them to the frame. The polymer solidifies on cooling and the mold is opened to allow the complete valve to be removed.
The leaflets may also be formed using a reaction-molding process (RIM) whereby the polymer is synthesized during the leaflet forming. A mold is constructed as described above. This mold is inserted in a reaction-injection molding machine, the frame is inserted in the mold and the machine injects a reactive mixture into the cavity. The polymer is produced by the reaction in the cavity to form the leaflets and bond them to the frame. When the reaction is complete, the mold is opened to allow the complete valve to be removed.
Yet a further option is to compression mold a valve initially dipped. This approach allows the leaflet thickness or thickness distribution to be adjusted from that initially produced. By varying the thickness of the leaflets the dynamics of the valve opening and closing can be modified. For example, the thickness of the leaflet along a cross-section defined by the intersection of a plane perpendicular to the blood flow axis and the leaflet can be varied so that the thickness changes gradually and substantially continuously from a first end of the cross-section (i.e., first edge of the leaflet) to a second end of the cross-section (i.e., second edge of the leaflet) in such a way that the mean thickness of the first half of the leaflet is different from the mean thickness of the second half of the leaflet. This will result in the thinner half of the leaflet opening first and creating a sail-like opening motion along the free edge of the leaflet.
Leaflet shape resulting from conventional injection molding, reaction injection molding or compression molding, is substantially defined by the composite wave described above. It will differ in detail for many of the same reasons identified for dip molding.
The valves of the present invention are manufactured in the neutral position or close to it and are therefore substantially free of bending stresses in this position. As a result when the leaflet is moved to its closed position the total bending energy at the leaflet center free edge and at the commissures is reduced compared to a valve made according to U.S. Pat. No. 5,376,113 (Jansen et al.).
The valves of the present invention may be used in any required position within the heart to control blood flow in one direction, or to control flow within any type of cardiac assist device.
The following examples 1 and 2 use the same scallop geometry described using the constants set forth in Table 1: While the examples described herein relate to one valve size, the same method can be used to produce valves from a wide range of sizes. This can be carried out by modifying the constants used in the equations, by resealing the bounding curves such as X closed (Z) and computing and iterating in the normal fashion or by rescaling the leaflet.
TABLE 1
values (mm)
R
11.0
E So
21.7
E sJ
21.5
E sN
13.8
H sO
0.18
f(Z)
(0.05.Z) + 1.0
EXAMPLE 1
The parameters described in the preceding sections are assigned the values set forth in Table 2 and are used to manufacture a symmetric valve. The included angle between adjacent leaflet free edges at the valve commissure for this valve is approximately 50°.
TABLE 2
Parameter
Value (mm)
Closed position
Z cO
0
Z cO
0.0
E cN (Z)
E cN = 3.0.Z + 50.3
E cO
22.0
E cJ
20.0
X T(Z)
0.0
Partially-open position
θ
12.7°
E oJ
50.0
Z oO
4.0
E oO
51.8
E oN
27.7
A u
Result from iteration procedure finds that
A u varies from 1e−5 at the leaflet base to
5.1 at 4 mm from the leaflet base to 3.8 at
the free edge.
A s (Y)
1.0
B s
Result from iteration procedure finds that
B s varies from 1e−3 at the leaflet base to
1.6 at 3 mm from the leaflet base to 0.6 at
the free edge.
FIG. 12 shows the symmetric valve which is manufactured, using the values outlined in Table 1 and Table 2.
EXAMPLE 2
The parameters described in the preceding sections are assigned the values set forth in Table 3 and are used to manufacture an asymmetric valve. The included angle between adjacent leaflet free edges at the valve commissure for this valve is approximately 48°.
TABLE 3
Parameter
Value (mm)
Closed position
Z cO
0.0
E cN (Z)
E cN = 3.0.Z + 48.9
E cO
18.4
E cJ
20.0
X T(Z)
X T(n−1) = 0.97.(X T(n) ) where X T(free edge) = 2.1
Partially-open position
θ
7.1°
E oJ
50.0
Z oO
5.0
E oO
51.5
E oN
29.0
A u
Result from iteration procedure finds that
A u varies from 1e−5 at the leaflet base to
3.1 at 3 mm from the leaflet base to 2.2 at
9 mm from the leaflet base to
3.8 at the free edge.
A s (Y)
B s (Y) = (Y − c)/m where B s = 1 at leaflet base
and m = 5.04 and c = −15.1 at leaflet free
edge.
B s
Result from iteration procedure finds that
B s varies from 1e−3 at the leaflet base to
1.1 at 6 mm from the leaflet base to 0.4 at
the free edge.
FIG. 13 shows the valve which is manufactured using the values outlined in Table 1 and Table 3.
TABLE 4
Definition of Parameters
R
Internal radius of valve
Scallop (FIG. 2)
X ell , H sJ , H sN , X hyp are used to define a surface which, when
intersected with a cylinder, scribe a function which forms the
scallop for one leaflet. This method for creating a scallop is
described in Mackay et al., Biomaterials 17 1996, although an added
variable f(Z) is used for added versatility.
X ell
Scribes an ellipse in the radial direction.
X hyp
Scribes a hyperbola in the circumferential
direction.
E sO
Ellipse X-axis offset
E sJ
Major axis of the ellipse
E sN
Minor axis of the ellipse
H sJ
Major axis of the hyperbola
H sN
Minor axis of the hyperbola
H sO
Hyperbola x-axis offset
f(Z)
Creates a varying relationship between
H sN and H sJ
Closed Leaflet geometry C (FIGS. 3 & 4)
X closed (Z) is defined as an ellipse (with a minor axis E cN (Z) which
changes with Z) in the XZ axis in the plane defined in FIG. 2 by
cutting plane 3-3. It is defined using the following constants and
functions.
Z cO
Closed ellipse Z-axis offset
E cN (Z)
Closed ellipse minor axis which changes
with Z
E cO
Closed ellipse X-axis offset
E cJ
Closed ellipse major axis
X T(Z)
Offset function which serves to increase
the amount of material in the belly
Molded position P
P is enclosed by a number (n) of contours P(X, Y) n which run from
one side of the scallop to the other. The underlying function X u is
used in defining both symmetric and asymmetric leaflets. X u is
simply an ellipse (or other such function) running in a plane from
one side of the scallop to the other. The points on the scallop are
designated X (n,0) , Y (n,0) where n refers to the contour number (see
FIGS. 5, 7, 9, 11B).
Y
Variable in plane from Y (n,0) to −Y (n,0)
A u
A u is the amplitude of the underlying
wave
A s (Y)
A s is a function which biases the wave
amplitude in a defined way, e.g. the
amplitude of the wave can be increased
near the commissure if so desired.
B s
B s is the amplitude of the superimposed
wave
Composite Curve (FIGS. 7 & 9)
X c
X coordinate for defining the composite
curve. This is derived using X u and X s
Y c
Y coordinate for defining the composite
curve. This is derived using X u and X s
Open Leaflet position (FIG. 10)
X open (Z) is defined as an ellipse in the XZ axis in the plane defined in
FIG. 2 by cutting plane 3-3. The contours defined in Composite
Curve are married to the Open Leaflet position X open (Z) to produce
the molded leaflet P.
It is defined using the following constants.
E oJ
Open ellipse major axis
Z oO
Open ellipse Z-axis offset
E oO
Open ellipse X-axis offset
E oN
Open ellipse minor axis
θ
Former taper angle
2. Second embodiment of heart valve prosthesis
The following describes another particular way of designing a second embodiment of a valve of the present invention. Other different design methodology could be utilized to design a valve having the structural features of the valve disclosed herein. Five computational steps are involved in this particular method:
(1) Define the scallop geometry (the scallop, 5 , is the intersection of the leaflet, 2 , with the frame, 1 ); (2) Define a contour length function L(z) and use this function to define a valve leaflet in the closed position C and optimize the stress distribution on the valve. The stress distribution can be confirmed using Finite Element Analysis (FEA). Thus the resulting stress distribution results from the length function L(Z) and FEA is used to confirm the optimal L(Z); (3) Rebuild the leaflet in a partially open position P; and (4) Match, using contour lengths, the computed leaflet area distribution in the partially open or molded position P to the defined leaflet in the closed position C. This ensures that when an increasing closing pressure is applied to the leaflets, they eventually assume a shape which is equivalent to that defined in closed position C.
This approach allows the closed shape of the leaflets in position C to be optimised for durability while the leaflets shaped in the molded partially open shape P can be optimised for hemodynamics. This allows the use of stiffer leaflet materials for valves which have good hemodynamics. An XYZ coordinate system is defined as shown in FIG. 2 , with the Z axis in the flow direction of blood flowing through the valve.
The leaflets are mounted on the frame, the shape of which results from the intersection of the aforementioned leaflet shape and a 3-dimensional geometry that can be cylindrical, conical or spherical in nature.
The leaflets are mounted on the frame, the shape of which results from the intersection of the aforementioned leaflet shape and a 3-dimensional geometry that can be cylindrical, conical or spherical in nature. A scallop shape is defined through cutting a cylinder of radius R (where R is the internal radius of the valve) with a plane at an inclined angle. The angle of the cutting plane is dictated by the desired height of the leaflet and the desired distance between the leaflets at the commissures.
The closed leaflet geometry in closed position C is chosen to minimize stress concentrations in the leaflet particularly prone to occur at the valve commissures. The specifications for this shape include:
(1) inclusion of sufficient material to allow a large open-leaflet orifice; (2) arrangement of this material to minimize redundancy (excess material in the free edge, 3 ) and twisting in the centre of the free edge, 3 ; and (3) arrangement of this material to ensure the free edge, 3 , is under low stress i.e., compelling the frame and leaflet belly to sustain the back-pressure.
The closed leaflet geometry is formed using contours S(X,Y) n sweeping from attachment points on one side of the scallop to the congruent attachment point on the opposite side of the scallop, where n is an infinite number of contours, two of which are shown in FIG. 4B . The geometry of the contours S(X,Y) n can be simple circular arcs or a collection of circular arcs and tangential lines; the length of each contour is defined by L(Z). Hence the geometry is defined and modified using the length function L(Z).
Thus the scallop shape and the contours S(X,Y) n are used to form the prominent boundaries for the closed leaflet in the closed position C. This process can be shortened by reducing the number of contours used to represent the surface (5<n<200). For design iteration, the ease with which the leaflet shape can be changed can be improved by reducing the number of contours to a minimum (i.e., n=5), although the smoothness of the resulting leaflet could be compromised to some extent. Upon optimising the function L(Z) for stress distribution, the number of contours defining the leaflet can be increased to improve the smoothness of the resulting leaflet (100<n<200). The function L(Z) is used later in the definition of the geometry in the partially open position P.
The aforementioned processes essentially define the leaflet shape and can be manipulated to optimise for durability. In order to optimise for hemodynamics, the same leaflet is molded in a position P which is intermediate in terms of valve opening. This entails molding large radius curves into the leaflet which then serve to reduce the energy required to buckle the leaflet from the closed to the open position. The large radius curves can be arranged in many different ways. Some of these are outlined herein.
As previously described with respect to the first embodiment the leaflet may be molded on a dipping former as shown in FIG. 14 . However, in this embodiment to aid removal of the valve from the former and reduce manufacturing stresses in the leaflet the former is preferably not tapered.
The geometry of the leaflet shape can be defined as a circular and trigonometric arrangement (or other mathematical function) preferably circular and sinusoidal in nature in the XY plane, comprising one or more waves, and having anchoring points on the frame. Thus the valve leaflets are defined by combining at least two mathematical functions to produce composite waves, and by using these waves to enclose the leaflet surface with the aforementioned scallop.
One such possible manifestation is a composite curve consisting of an underlying circular arc or wave upon which a second higher frequency sinusoidal wave is superimposed. A third wave having a frequency different from the first and second waves could also be superimposed over the resulting composite wave. This ensures a wider angle between adjacent leaflets in the region of the commissures when the valve is fully open thus ensuring good wash-out of this region.
The composite curve, and the resulting leaflet, can be either symmetric or asymmetric about a plane parallel to the blood flow direction and bisecting a line drawn between two stent tips such as, for leaflet 2 a , the section along line 3 - 3 of FIG. 2 . The asymmetry can be effected either by combining a symmetric underlying curve with an asymmetric superimposed curve or vice versa, or by utilising a changing wave amplitude across the leaflet.
The following describes the use of a symmetric underlying function with an asymmetric superimposed function, but the use of an asymmetric underlying function will be obvious to one skilled in the art. The underlying function is defined in the XY plane and connects the leaflet attachment points to the scallop at a given height from the base of the valve. This underlying function shown in FIG. 15 , can be trigonometric, elliptical, hyperbolic, parabolic, circular, or other smooth analytic function or could be a table of values.
The superimposed wave is defined in the XY plane, and connects the attachment points of the leaflet to the scallop at a given height above the base of the valve. The superimposed wave is of higher frequency than the underlying wave, and can be trigonometric, elliptic, hyperbolic, parabolic, circular, or other smooth analytic function, or a table of values.
One possible asymmetric leaflet design is formed when the underlying wave formed using a circular arc is combined with a superimposed wave formed using the following equation.
X
s
=
-
A
s
·
B
s
(
Y
)
·
sin
[
(
1.5
·
π
Y
(
n
,
0
)
)
·
(
Y
-
Y
(
n
,
0
)
)
]
A circular arc is defined by its cord length, 2Y (n,O) , and amplitude, A u , as shown in FIG. 15 . A s can be varied across the leaflet to produce varying wave amplitude across the leaflet, for example lower amplitude in one commissure than the opposite commissure. B s can be varied to adjust the length of the wave. The superimposed wave is shown in FIG. 16 . The composite wave formed by combining the underlying wave ( FIG. 15 ) with the superimposed wave ( FIG. 16 ) is shown in FIG. 17 . The composite wave W(X c, Y c ) n is created by offsetting the superimposed wave normal to the surface of the underlying wave ( FIG. 17 ). Positive γ is defined as the direction of the normal to the underlying wave relative to the x-axis. When Y is positive, the composite curve is created by offsetting in the direction positive γ and where Y is negative the composite curve is created by offsetting in the direction negative γ (the offset direction is shown by arrows for a positive Y point and a negative Y point in FIG. 17 .
While the general shape of the leaflet in position P has been determined using the composite wave, at this stage it is not specified in any particular position. In order to specify the position of P, the shape of the partially open leaflet position can be defined using the ratio of the amplitude of the circular arc A u to the amplitude of the sinusoidal wave B s .
A large ratio results in a leaflet which is substantially closed and vice versa. In this example the ratio changes from 10 at the base of the leaflet to 4 at the free edge of the leaflet. The result of this is a leaflet which effectively is more open at the free edge than at the base of the leaflet. In this way, the degree of ‘openness’ of the leaflet in position P can be varied throughout the leaflet.
The composite wave is thus defined to produce the molded “buckle” in the leaflet, and the amplitude ratio is used to define the geometry of the leaflet at position P. At this stage it may bear no relation to the closed leaflet shape in position C. In order to match the area distribution of both leaflet positions, (thus producing essentially the same leaflet in different positions) the composite wave length is iterated to match the length of the relevant leaflet contour in position C. Thus the amplitude and frequency of the individual waves can be varied in such a manner as to balance between: (a) producing a resultant wave the length of which is equal to the relevant value in the length function L(Z) thus approximating the required closed shape when back pressure is applied, and (b) allowing efficient orifice washout and ready leaflet opening.
This process identifies the values of A u and B s to be used in constructing the mold for the valve leaflet. As long as the constants such as A u and B s are known, the surface of the leaflet in its molded position can be visualised, enclosed and machined in a conventional manner. As a result of this fitting process the composite wave retains the same basic form but changes in detail from the top of the leaflet to the bottom of the leaflet. A composite wave can be defined in the leaflet surface as the intersection of the leaflet surface with a plane normal to the Z axis.
In summary therefore one possible method of designing the leaflet of the second embodiment of the present invention is in the following way:
(1) Define a scallop shape; (2) Define a shape representing the closed leaflet using a contour length function L(Z); (3) Use circular arcs and sine waves to generate a geometry which is partially-open, which pertains to a leaflet position which is between the two extreme conditions of normal valve function, i.e., leaflet open and leaflet closed; (5) Vary the amplitude of the arcs and the sinewaves to fit to the length function L(Z); and (6) The respective amplitudes of the circular arcs and sine waves can be varied from the free edge to leaflet base, for example the degree of ‘openness’ of the leaflet can be varied throughout the leaflet.
Example 3 set forth hereafter is an example of how the invention of the second embodiment can be put into practice. Using the scallop constants in Table 5, the constants required to produce an example of an asymmetric leaflet valve are given in Table 6. These constants are used in conjunction with the aforementioned equations to define the leaflet geometry.
With one leaflet described using the aforementioned equations, the remaining two leaflets are generated by rotating the geometry about the Z axis through 120° and then through 240°. These leaflet shapes are inserted as the areas of the dipping mold (otherwise known as a dipping former), which form the majority of the leaflet forming surfaces, and which then forms a 3-dimensional dipping mold. The composite wave described in the aforementioned equations, therefore substantially defines the former surface which produces the inner leaflet surface. A drain-off area 30 is also created on the former to encourage smooth run-off of polymer solution. The drain-off region 30 is defined by extruding the leaflet free edge away from the leaflet and parallel to the flow direction of the valve for a distance of approximately 10 mm. The transition from leaflet forming surface of the dipping mold 24 to the drain-off surface of the dipping mold 30 is radiused with a radius greater than 1 mm and preferably greater than 2 mm to eliminate discontinuities in the leaflet.
The details of the manufacture of the valve of the second embodiment are similar to those previously described with respect to the valve of the first embodiment until the valve is removed from the dipping mold. Since the former used in making the valve of the second embodiment is not tapered the stent posts are not deflected by the former and do not move or change the leaflet shape when the valve is removed from the mold. At this stage the dipping mold and frame is covered with an excess of polyurethane due to the drain-off of the polymer onto the region of the mold known as the drain-off area 30 . To maintain the integrity of the frame coating, the leaflet is trimmed above the stent tips at a distance of between 0.025 to 5 mm preferably 0.5 mm to 1.5 mm from the stent tip. Thus part of the surface of the leaflet is formed on the drain-off region 30 which is substantially defined using the composite wave W(X c, Y c ) 0 . Leaflet free edges may be trimmed of excess material using a sharp blade rotated around the opened leaflets or using laser-cutting technology or other similar technology.
The valve of the second embodiment may be used in any required position within the heart to control blood flow in one direction, or to control flow within any type of cardiac assist device.
The following example 3 uses the same scallop geometry described using the constants set forth in Table 5: While the example 3 described herein relates to one valve size, the same method can be used to produce valves from a wide range of sizes. This can be carried out by modifying the constants used in the equations, and computing and iterating in the normal fashion or by rescaling the leaflet.
TABLE 5
values (mm)
R
11.0
slope
−2.517
intersection
14.195
EXAMPLE 3
The parameters described in the preceding sections are assigned the values set forth in Table 6 and are used to manufacture an asymmetric valve according to the second embodiment. The included angle between adjacent leaflet free edges at the valve commissure for this valve is approximately 30°.
TABLE 6
Parameter
Value (mm)
Closed position
L(Z)
Varies from 0.025 mm at the leaflet base
to 21.3 mm at the free edge
Partially-open position
θ
0°
A u
Result from iteration procedure finds that
A u varies from 0.0006 at the leaflet base
to 3.8 at 10.7 mm from the leaflet base to
3.35 at the free edge.
A s
At the free edge of the leaflet, A s (Y)
varies from 1.5 mm at one side of the
scallop to 1.0 mm at the opposite side of
the scallop.
At the base of the leaflet, A s (Y) is 1.0 mm.
B s
Result from iteration procedure finds that
A s varies from 0.0006 at the leaflet base
to 0.839 mm at the free edge.
FIG. 18 shows the asymmetric valve which is manufactured, using the values outlined in Table 5 and Table 6.
TABLE 7
Definition of parameters
R
Internal radius of valve
Scallop (FIG. 2)
The scallop is defined using a simple straight line, defined using a
slope and intersection, to cut with a cylinder.
Closed Leaflet geometry C
L(Z) is used to modify the inherent geometry of the leaflet. Circular
arcs and straight lines can be used to enclose the surface defined
using L(Z).
Molded position P
P is enclosed by a number (n) of contours W(X, Y) n which run from
one side of the scallop to the other. The underlying function is used
in defining both symmetric and asymmetric leaflets. running in a
plane from one side of the scallop to the other. The points on the
scallop are designated X (n,0) , Y (n,0) where n refers to the contour
number (see FIGS. 15, 16, 17, 18).
Y
Variable in plane from Y (n,0) to −Y (n,0)
A u
A u is the amplitude of the underlying
wave
A s (Y)
A s is a function which biases the wave
amplitude in a defined way, e.g. the
amplitude of the wave can be varied
from commissure to commissure to
produce asymmetry in the leaflet.
B s
B s is the amplitude of the superimposed
wave
Composite Curve (FIGS. 17)
X c
X coordinate for defining the composite
curve.
Y c
Y coordinate for defining the composite
curve.
Open Leaflet position (FIG. 18)
The open leaflet position is defined using a ratio which determines
the degree of “openness” of the leaflet.
θ
Former taper angle | 4y
|
BACKGROUND OF THE INVENTION
(a) Field of the Invention
This invention relates to provide novel toxoids of elastase which is originated from Pseudomonas aeruginosa through inactivating its virulence, in other words, any toxoidizing with a synthetic peptide reagent of chloroacetyl-N-hydroxy-L-leucyl-L-alanylglycinamide while leaving its antigenity as it is.
(b) Description of the Prior Art
Pseudomonas aeruginosa is gram-negative and aerobic bacillus which generally co-exist with pyogenic bacillus and is known to be a pathogen of pyothorax, tympanitis, cystitis, hemorrhagic pneumonia, etc., on human beings and mammalian animals, especially on a mink, which is known to be one of the most expensive sources of furs. In both the fields of human and veterinary medicines, so-called "Opportunistic infections" caused by Pseudomonas aeruginosa has recently provoked an attention among doctors as the subject to be solved urgently, and immunotherapy as well as chemotherapy using antibiotics have been carried out for preventing and treating said infections, however, they are said yet incomplete and are under development.
In regard with the above-mentioned immunotherapy, the same inventors as this invention's had reached the findings that enzyme such as elastase and protease of Pseudomonas aeruginosa origin possessed antigenic activity, however, they also possessed undesirable activity such as destroying the protein tissues of patients and these undesirable enzymatic activities made infectious diseases caused by Pseudomonas aeruginosa hard to cure.
Then, for the purpose of inactivating as above these undesirable enzymatic actions while leaving desirable antigenic actions as they are, there were provided the toxoids of elastase and protease which were respectively inactivated with formalin, and the vaccine which consisted of the abovementioned two kinds of toxoid and an antigen named OEP, which was derived from Original Endotoxin Protein, which was commonly found in more than 13 kinds of Pseudomonas aeruginosa strains. Production, physicochemical properties and immunological properties of the above two kinds of toxoid together with the production of purified crystalline elastase and protease, which were used as a raw material of the toxoids, were disclosed, for example, in the specification of U.S. Pat. No. 4,160,023 patented on July 3, 1979 and those of the latter vaccin were disclosed, for example, in the specification of U.S. Pat. No. 4,157,389 patented on June 5, 1979 by the same inventors as this invention's.
SUMMARY OF THE INVENTION
This invention relates to toxoids which are first prepared from purified crystalline elastase obtained from Pseudomonas aeruginosa by treating it with a known synthetic peptide reagent or treating it preliminarily with formalin, then, with the synthetic peptide reagent for inactivating its enzymatic proteinase activity while leaving its antigenic activity as it is. The synthetic peptide reagent herein employed is chloroacetyl-N-hydroxy-L-leucyl-L-alanylglycinamide represented by a following formula:
ClCH.sub.2 CO-N--HO--L--Leu--L--Ala--L--Gly--NH.sub.2,
wherein Leu, Ala and Gly respectively express leucine, alanine and glycine, which is hereinafter referred to as "Powers Reagent" throughout this specification.
The novel toxoids of this invention are stable in their activity for a longer period of time than that of the toxoids of elastase which were invented and disclosed by the present inventors in U.S. Pat. No. 4,160,023, and the present toxoids are effective to prevent and treat infectious diseases caused by Pseudomonas aeruginosa both on human beings and mammalian animals.
DETAILED DESCRIPTION OF THE INVENTION
The afore mentioned and known toxoids were characterized by the relatively simple producing procedures, which will necessarily lower production costs, however, our recent clinical experiences have taught that an excess treatment of elastase with formalin designed to positively remove its undesirable proteinase activity, for instance, to the extent of less than 1/100 in potency of that of the original activity, may cause a sudden drop of its desirable activity simultaneously, as shown in a following Table:
TABLE 1______________________________________ Residual Proteinase Antigenic ActivitySample Activity (%) (μg/ml)______________________________________Untreated 100 30Treated with 8 30HCHO (No. 1)Treated with 5.5 30HCHO (No. 2)Treated with 1.5 60HCHO (No. 3)Treated with 0.7 240HCHO (No. 4)Treated with 0.3 480HCHO (No. 5)______________________________________
Note: In the above Table 1, the antigenic activity is expressed by a unit of μg/ml, wherein the numerator indicates the quantity of antigen and the denominator indicates the dilution volume required until a precipitation line first becomes visible. So the larger the numeral is, the less potent the antigen activity.
The present invention has been attained for the purpose of improving above these defects found on the known elastase toxoids and providing stable and effective elastase toxoids.
The Powers Reagent employed in this invention as an inactivator was at first disclosed by N. Nishino and James C. Powers in the Journal of Biological Chemistry (USA), Vol. 225, No. 8, pages 3482-3486 (1980), in which Dr. Powers et al. stated that the incubation of this reagent with Pseudomonas aeruginosa elastase resulted in a progressive loss of enzyme activity, however, no discussions were made by them about any influences on its antigenic activity.
The physical and chemical properties of Powers Reagent are as follows:
Melting point; 65°-75° C. (Decomposition) 1 HNMR spectrum; 9.8 (1H, b, CONCOH), 3.7 (2H, d, NHCH 2 CO), 1.4 (3H, d, CH 3 CH), 0.9 (6H, d, CH 3 CH), 8.2-7.9 (2H, m, 2CONH), 7.0 (2H, d, CONH 2 ), 4.4 (2H, ClCH 2 CO).
One of the products of this invention is a toxoid which is prepared by inactivating Pseudomonas aeruginosa elastase with the Powers Reagent, hereinafter referred to as "Toxoid I", and the other product of this invention is a toxoid which is prepared by inactivating Pseudomonas aeruginosa elastase once with formalin then with a Powers Reagent, hereinafter referred to as "Toxoid II". These toxoids are prepared through procedures conventionally adopted in the field of protein chemistry, and the preparation of purified crystalline elastase therein used as a raw material was disclosed by one of the inventors of this invention, K. Morihara, in the Journal of Biological Chemistry (USA), Vol. 210, pages 3295-3304 (1965) in detail (cf. U.S. Pat. No. 4,160,023).
EXAMPLE
EXAMPLE 1
Preparation of Toxoid I
One hundred milligrams of crystalline elastase and 50 mg of Powers Reagent were dissolved in 100 ml of 0.1M tris-buffer solution (pH 7.0) and the solution was kept for 24 hours long at a room temperature. The reactant was dialyzed against water and the dialysate was lyophilized, then, 95 mg of toxoid which showed 0.06 mPU/mg protein of a specific activity were given.
The meaning of "mPU/mg protein of a specific activity" will be explained later in this specification.
EXAMPLE 2
Preparation of Toxoid II
A solution of 100 mg of purified crystalline elastas with or without 0.1M lysine in 0.1M phosphate buffer solution (pH 7.0) which contained 1% of formalin and the solution was kept for two days at room temperature. The reactant was dialyzed against water to remove formalin and lysine, and was concentrated with a collodion film, then, 22 ml of water solution which were equivalent to 4 mg protein/ml, of which the specific activity was equal to 3.75 mPU/mg protein (residual activity 7.5%).
To the thus-formed solution, 22 ml of 0.2M tris-buffer solution (pH 7.0) which dissolved 8 mg of Powers Reagent were added and the mixed solution was kept for 3 days at room temperature and was dialyzed against water and was lyophilized, then, 80 mg of toxoid, which were equivalent to 1/500 of the activity which the original crystalline elastase possessed, were given.
Moreover, under the same experimental conditions as the above, the formalin-inactivated elastases were respectively treated with each 2, 1, 0.5 and 0.1 mgs of Powers Reagent, then, there were respectively given 80-85 mg of the toxoids, each of which possessed 0.15, 0.2, 0.3 and 0.6 mPU/mg protein of a specific activity.
From the result thus observed in Example 2, it is recommended, from a practical viewpoint, that to provide such a toxoid which possesses a proteinase activity of less than 1/500 of that of an original crystalline elastase, the elastase should be treated with 1% of formalin solution so as to decrease its proteinase activity into 1-10%, preferably around 5%, of that of the original elastase and then a Powers Reagent is added in a quantity of corresponding to the thus remained active elastase in which 50 mPU correspond to 1 mg of elastase.
Further, in comparison of the above Example 1 with Example 2, it must be noted that the quantity of Powers Reagent in respect to 100 mg of the material crystalline elastase is as much as 50 mg in the Example 1 and 8 mg in Example 2. As the Powers Reagent is a relatively expensive substance, the latter Toxoid II is more advantageous in production cost than the former Toxoid I when they are produced massively. On the other hand, the biological and immunological properties are almost equal to each other.
In Examples 1 and 2, the term "mPU/ml protein of a specific activity" signifies the proteinase activity determined by the following procedure:
Casein (2%, pH 7.4, 1 ml) is admixed with 1 ml of an appropriately diluted solution of an enzyme, and after a reaction at 40° C. for 10 minutes, 2.0 ml of a solution containing 0.1M trichloroacetic acid and 0.2M sodium acetate is immediately added for stopping a progress of the reaction. The mixture is kept at the same temperature for 20 minutes to precipitate unreacted casein completely and is filtered. 1 ml of the filtrate is subject to determination of tyrosine therein contained by the Folin's method. By the increase of 1γ of tyrosine per 1 minute, a proteinase activity of 1 mPU is to be indicated. 1 mPU×1,000 is equal to 1 PU.
The physical and chemical properties of Toxoid I have been identified following:
(1) Molecular weight: 20,400 (determined by a method of SDS-polyacrylamide gel cataphoresis).
(2) Ultraviolet absorption spectrum: Maximum 280 nm (E 1 280 %=14.52, pH 10), Minimum 252 nm.
(3) Isoelectric point: pH 7.0 (determined by a cataphoresis with an acetate film).
(4) Composition of amino acids: Amino acid residues (mol protein) Aspartic acid (15.7), Threonine (6.9), Serine (9.2), Glutamic acid (6.3), Proline (4.5), Glycine (13.5), Alanine (11.0), cystine/2 (1.6), Valine (6.7), Methionine (3.0), Isoleucine (3.0), Leucine (5.4), Tyrosine (8.2), Phenylalanine (6.3), Lysine (4.4), Histidine (2.5), Arginine (5.9), Tryptophane (3.0) (Total 117.1 residues).
(5) Color: Colorless powders
(6) Antigenic activity: Positive
(7) Enzymatic activity: Negative, and the chemical and physical properties of Toxoid II have been identified followingly;
(1) Molecular weight: 23,300 (determined by a method of SDS-polyacrylamide gel cataphoresis)
(2) Ultraviolet absorption spectrum: Maximum at 280 nm (E 1 280 %=11, pH 10), Minimum at 252 nm
(3) Isoelectric point: pH 6.0 (determined by a cataphoresis with an acetate film).
(4) Composition of amino acids: Amino acid residues (mol protein) Aspartic acid (18.1), Threonine (7.9), Serine (10.6), Glutamic acid (7.3), Proline (5.2), Glycine (14.7), Alanine (11.8), Cystine/2 (1.8), Valine (7.8), Methionine (3.5), Isoleucine (3.8), Leucine (6.1), Tyrosine (1.6), Phenylalanine (7.1), Lysine (8.7), Histidine (3.7), Arginine (7.0), Tryptophane (3.5) (Total: 130.2 residues)
(5) Color: Colorless powders
(6) Antigenic activity: Positive
(7) Enzymatic activity: Negative
EXPERIMENT
Immunological properties of Toxoid I and Toxoid II of this invention will be demonstrated by the following experimental data:
EXPERIMENT 1
Antigenicity Test on Rabbits
Method: Three rabbits, each having 2.5 Kg of a body weight, were subcutaneously inoculated with each 1 mg of Toxoid I together with Freund's incomplete adjuvant and the inoculation was repeated 3 to 4 times at an interval of 2 weeks. On the day of two weeks after the last inoculation, blood was collected from the rabbits and was availed for following Tests A, B and C. The same method as the preceeding was conducted employing Toxoid II.
TEST A
Passive Hemagglutinative Value Test (PHA Test)
The values were determined according to a method described by one of the present inventors, Y. Homma, in The Japan J. Exp. Med., Vol. 45, No. 5, pages 361-365 (1975), and the values were expressed as a reciprocal number to a multiplied number of the dilution of sera.
______________________________________Results:PHA ValueToxoid I Toxoid II______________________________________(Rabbit No. 1) 5120 (Rabbit No. 4) 5110(Rabbit No. 2) 2560 (Rabbit No. 5) 2560(Rabbit No. 3) 2560 (Rabbit No. 6) 2550______________________________________
Note: Before the first inoculation, No elastase PHA value was observed.
TEST B
Precipitation in Agar-gel Test
In 0.01M phosphate buffer-normal saline solution (pH 7.0) which contained 0.1% of sodium azide, agarose was dissolved to form a concentration of 1.5% by weight, and 10 ml of the solution were poured in a dish having 9 cm of a diameter and the solution was left to make the agar hard. Several holes were made on the hardened agar and antigens or antisera were separately poured into every hole and the agar was left at 22° C. for 24 hours long, then, the existence of a precipitation line was inspected. The concentration of antigens is expressed by a unit of μg/ml, wherein the numerator indicates a quantity of antigens and a denominator indicates the dilution volume which is required until a precipitation line will first becomes observable.
______________________________________Results:Antigen Concentration(μg/ml)Toxoid I Toxoid II______________________________________(Rabbit No. 1) 15 (Rabbit No. 4) 15(Rabbit No. 2) 15 (Rabbit No. 5) 15(Rabbit No. 3) 15 (Rabbit No. 6) 15______________________________________
Note: The same test as the preceeding employing an authentic crystalline elastase also resulted in a concentration of 15 μg/ml.
TEST C
Elastase-neutralizing Activity Test
Sera of the tested rabbits were warmed at 56° C. for 30 minutes and 0.2 ml of the sera were added to 0.2 ml of elastase solution, to which normal saline solution was added up to a volume of 2 ml in total. The solution was left for 60 minutes at 37° C., then, 1 ml of 2% casein solution was added to 1 ml of the solution. The residual elastase activity was determined with the thus mixed solution. Values of an elastase activity with which 1 ml of anti-serum could be neutralized were demonstrated as follows:
______________________________________Results:Elastase-neutralizing Activity(mPU/ml)Toxoid I Toxoid II______________________________________(Rabbit No. 1) 15 (Rabbit No. 4) 15(Rabbit No. 2) 12 (Rabbit No. 5) 13(Rabbit No. 3) 10 (Rabbit No. 6) 11______________________________________
EXPERIMENT 2
PHA and Elastase-neutralizing Activity on Mice
To a solution of Toxoid I of this invention in a concentration of 0.5 mg/ml., an equal volume of 1% potassium alum solution was added. Each 0.2 ml of the solution, in which 50 μg of Toxoid I were contained, were inoculated into ddY mice of 4 weeks old respectively three times at an interval of 2 weeks. At just before and on the 14th day after the third inoculation, bloods were collected from each mouse and the values of PHA and elastase-neutralizing activity were inspected in the same manner as with Tests A and C in Experiment 1.
The PHA value was commonly 640 with the first and the second collected bloods and the value of elastase-neutralizing activity was 1.52 mPU/ml with the first collected-blood and 1.83 mPU/ml with the second collected-blood.
The toxoid II of this invention was treated in the same manner as above, which resulted commonly in a PHA value of 640 with the first and the second collected-blood and the value of the elastase-neutralizing was 1.55 mPU/ml with the first collected blood and 1.80 mPU/ml with the second collected blood.
EXPERIMENT 3
Antigen Activity on Minks
Two groups, each consisted of twenty or more Sapphire minks, were subcutaneously inoculated with each 500 μg Toxoid I or Toxoid II together with an adjuvant of potassium alum for vaccinization. Two weeks later, each 500 μg of Toxoid I or Toxoid II were inoculated with the adjuvant similarly to the first inoculation. Further, three weeks after the second inoculation, each 1,000 μg of Toxoid I or Toxoid II were subcutaneously inoculated. On the 18th day from the last inoculation, every mink was drawn of its blood.
In most of the sera of the thus drawn bloods, an increase in PHA value of 16 to 60 fold of the original value was commonly observed.
From the results obtained from the above experiments, it was confirmed that injections of Toxoid I or Toxoid II of this invention may result in the prominent elevation of the PHA value and an antigen-neutralizing activity.
With respect to the acute toxicity of Toxoid I and Toxoid II of this invention, a LD 50 value has been commonly determined through an intraperitoneal administration on mice to be more than 1 mg/Kg of a body weight, while crystalline elastase of Pseudomonas aeruginosa origin is 0.125 mg/Kg of the body weight of a mouse.
Consequently, Toxoid I and Toxoid II of this invention are available, by themselves or together with pharmaceutically acceptable excipients as a pharmaceutical agent, for the production of antibodies or anti-sera, and they are useful for preventing and treating infectious diseases caused by Pseudomonas aeruginosa on human beings and mammalian animals.
To explain some practical uses of the toxoids of this invention, tested minks were divided into two groups, one was infected with Pseudomonas aeruginosa and the other was kept uninfected. Both of the group were treated with vaccine which was composed of the three components for the toxoid of this invention, a separately prepared protease toxoid from Pseudomonas aeruginosa and the foregoing explained OPE (cf. for example, U.S. Pat. No. 4,157,389), wherein, two groups of minks exhibited almost the same survival ratio, while there was found to be no survivals with a control group of minks which was infected but untreated with the vaccine.
Further, the vaccine will be preferably available for prevention and treatment of chronic infectious diseases caused by Pseudomonas aeruginosa which are generally said to be uncurable by the administration of antibiotics only, and acute Pseudomonas aeruginosa infectious diseases such as burns. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is concerned with a temperature-responsive record material for use in thermographic recording and reproducing systems and, more particularly an improved heat-sensitive record material comprising a supporting sheet provided with a heat-sensitive composition containing, in a single layer, mark forming components which react to produce a mark according to a selectively applied temperature pattern.
More particularly, the record element referring to the invention is adapted to be used for the data record in the systems wherein there are used as printing means, heated metal pins, thermic heads or any other device that transmits thermic energy.
2. Description of the Prior Art
Known in the literature there is the existence, which is therefore no object of the invention, of some colorless basic chromogenic compounds capable of being transformed into the colored form when coming into contact with acid or ionizing environments.
These compounds are, usually, leuco-compounds of triphenylmethane and fluorane dyestuffs having a lactonic structure and, among the most known thereof, there are cited here below: - 3,3-bis-(4-dimethylaminophenyl)-6-dimethylphthalide (Crystal Violet Lactone or CVL), giving a colour from blue to violet; - 3,3-bis-(p-dimethylaminophenyl)-phthalide or (Malachite Green Lactone or MGL), giving a green color; - Xanthene-9,0-benzoic acid, 3,6-bis-dimethylamino-9-p-nitroaniline lactam, giving a red color; - N-(p-nitrophenyl)-Rhodamine B-lactam (RBL) and 3',6'-bis-diethylaminofluorane both giving a red color.
In order to establish the acid or ionizing environment needed for their reaction, there are usually employed tannic acid, gallic acid, phenols, polyphenols and phenolic resins, anhydrides, anilides, imides, attapulgite, silica, etc.
It is furthermore known the use, for thermographic purposes, of layers containing, as a thermosensitive compound, mixtures of a basic chromogenic compound and an acidic compound. By selectively applying heat to said layers, the acidic compound melts thereby giving the suitable medium for turning the basic chromogenic compound into its colored form.
Nevertheless, temperature-responsive elements as above described show a marked tendency to develop color also in the absence of heat, so that this phenomenon already occurs by operating the mixture of the single dispersions comprising respectively the basic chromogenic compound and the acid compound.
In fact, the dispersions of CVL and acidic compounds, obtained by using water-soluble binders like casein, starch, modified starchs, pectine, polyvinyl acetate/crotonic acid copolymers, alkali-soluble phenolformaldehyde resins, polyvinylpyrocolidone and copolymers of it, gum arabic, urea-formaldehyde resins, etc. when mixed, give immediately a greenish color turning rapidly to a hell blue and dark blue color. In many cases, already the CVL dispersion appears greenish colored.
Besides the above cited inconveniences the specified thermographic layers also show a poor resistance to abrasion and to the operative conditions, owing to the presence of the water-soluble binders and to the low binding power of the colloid used in the dispersion.
SUMMARY OF THE INVENTION
A main object of the present invention is the preparation of dispersions of basic chromogenic compounds and of acid compounds, as well as of thermo-responsive layers containing same, which do not show the inconvenience of an untimely colored reaction until their real employment in thermo-sensitive recording systems and similar, and on the contrary provide layers of very good mechanic and coating uniformity characteristics.
Thus, according to the invention, there is provided an improved temperature-sensitive material, for use in a thermographic recording and reproducing apparatus, comprising a supporting sheet carrying a single layer containing, as the temperature-sensitive composition, a mixture resulting by dispersions of a crystal violet lactone and of an a phenolic compound in a binder, said composition being characterized in that as an essential binder a latex or a mixture of a latex with a non-ionic cellulose ether is used.
With the term "latex" is hereinafter intended a colloidal dispersion in water of synthetic polymers and/or copolymers which, being applied onto any surface, provides a transparent and homogeneous layer. If a pigment is added to the latex, the particles thereof become an integrant part of the dried layer.
According to the invention, it has been found that the use of latexes or mixtures thereof with non-ionic cellulose ethers as bidners allows the preparation of dispersions which are stable for a long time, as well as of temperature-responsive layers which are perfectly colorless at room conditions, and able to promptly develop color by heat, still keeping unchanged the good mechanic and layer uniformity characteristics.
It is known from the colloid chemistry that the latexes, bearing electric charges, undergo an immediate coagulation in the presence of pigments or other substances bearing a different charge.
A further object of the invention is therefore to individualize the latexes which either do not show said inconvenience of a coagulation in the presence of substances used for preparing the temperature-responsive layer, or for which the coagulation can be prevented by the use of a protective colloid.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The latexes being conveniently usable for the production of temperature-responsive layers according to the invention, belong to the following classes:
vinyl chloride copolymers
polystyrene
styrene-butadiene copolymers
styrene-butadiene carboxylate copolymers
modified acrylic copolymers
acrylic copolymers reticulated with zinc.
As a protective colloid for preventing the coagulation of the latexes not belonging to the classes just mentioned above, a non-ionic cellulose ether may be advantageously used of the type specified by Applicant in the copending U.S. Pat. application Ser. No. 499,702 filed on Aug. 22, 1974, which is a continuation application of Ser. No. 309,838 filed on Nov. 27, 1972 and now abandoned.
The use of synthetic polymers or copolymers as binders results in thermoresponsive layers showing characteristics similar to those of layers prepared by dispersing synthetic polymeric binders with solvents, and which show very good uniformity and good mechanic characteristics, without disadvantages.
In the temperature-responsive layers comprising the binders according to the invention, further auxiliary substances are incorporated which, not characterizing yet the dispersion, contribute to improve the mechanic and optical characteristics of the so achieved layers. These auxiliary substances may be in particular: lubricating agents such as metal stearate, in particular calcium, magnesium, lithium and aluminium stearates, waxes, the microtalc; absorbing pigments, such as silicates, clays, kaolin, zinc oxide, barium sulphate, talc, etc., optical whitening agents of the type used in the paper processing in general. The addition of these auxiliary components to the thermosensitive components according to the invention has proved particularly advantageous in those thermic writing and printing systems where a thermal writing head moving in contact with the layer is employed, as described by applicant by example in the copending U.S. Pat. application Ser. No. 309,838 filed on Nov. 27, 1972, in absence of said auxiliary additions, smudgment of the surface of the writing head in contact with the recording layer would occur.
The dispersions described below may be prepared using all known means of the technique and the rations of their components may be varied within a wide extent, always achieving good practical results.
When a mixture of latex with non-ionic cellulose ethers is used as the binder, the ratio of such mixture can be comprised between 100-0 parts and 3-97 parts by weight, bearing in mind that the ratio binder/solids may vary between 1:1 and 1:25.
The following examples will disclose some embodiments of the invention, without taking up a limiting character thereof.
EXAMPLE 1
The following dispersions are separately prepared:
A. a porcelain attritor (750 cc) was charged with 5 g of Crystal Violet Lactone (CVL), 20 g of Lutofan 300 D (Registered Trade Mark for a water dispersion without plasticizers based upon vinyl chloride, manufactured by the B.A.S.F., Badische Anilin u. Soda Fabrik) and 15.5 cc of water. The ingredients are ground for 24 hours and the mixture filtered.
B. a porcelain attritor (750 cc) was charged with 40 g of 4.4' -isopropylidenediphenol, 34 g of Lutofan 33 D and 106 cc of water. The ingredients are ground for 24 hours and the mixture filtered. 180 parts of A and 180 parts of B were mixed together, the resulting mixture was coated on paper weighing 55 g/m 2 , thus obtaining layers having a dry weight of 3-5 g/m 2 .
The thus obtained layer gives by heating in contact with a heated pin or a thermic printing head, light and humidity resistant blue colored marks.
EXAMPLE 2
The following dispersions are separately prepared:
A. a porcelain attritor (750 cc) was charged with 5 g of Crystal Violet Lactone (CVL), 10 g of Lithium stearate, 20 g of Lutofan 300 D and 40 g of zinc oxide, and added with 1 g of Tintofen HS-76 (Registered Trade Mark for optical whitening agents of the class of the stilbene and coumarine derivatives, manufactured by the GAF, General Aniline & Film Corp.) and 120 cc of water. The ingredients are ground for 24 hours.
B. a porcelain attritor (750 cc) was charged with 40 g of 4.4'-isopropyliden-diphenol, 40 g of zinc oxide, 34 g of Lutofen 300 D, 1 g of Tintofen HS-76 and 150 cc of water; the ingredients are ground for 24 hours.
196 parts of A and 265 parts of B were mixed together and the resulting mixture was coated on paper weighing 55 g/m 2 , thus obtaining layers having a dry weight of 5 - 7 gm 2 .
The so prepared layer gives, when heated by contact with a thermic printing element, perfectly light and humidity resistant blue colored marks.
EXAMPLE 3
Same as described in Example 1; by using as the binder Polyco 220 NS (Registered Trade Mark for polystirene emulsions manufactured by the Borden Chemical Co.), in the same proportion and with similar results.
EXAMPLE 4
Like Example 1, employing as the binder Dow Latex 636 (Registered Trade Mark for the styrene/butadiene dispersion manufactured by the Dow Chemical Co.)
EXAMPLE 5
Like Example 1, employing as the binder Dow Latex 815 (Registered Trade Mark for a styrene-butadiene carboxylate dispersion manufactured by the Dow Chemical Co.)
EXAMPLE 6
Like Example 1, employing as the binder Dow Latex 816 (Registered Trade Mark for a styrene-butadiene carboxilate manufactured by the Dow Chemical Co.).
EXAMPLE 7
Like Example 1, employing as the binder Primal B-231 (Registered Trade Mark for a modified acrylic copolymer manufactured by the Rohm & Haas Co.).
EXAMPLE 8
Like Example 1, employing as the binder Primal B-505 (Registered Trade Mark for an acrylic copolymer reticulated with zinc, manufactured by the Rohm & Haas Co.).
EXAMPLE 9
The following dispersions are separately prepared by charging in a porcelain attritor and grinding for 24 hours:
A. 15 g of Crystal Violet Lactone (CVL), 15 g of lithum stearate, 300 g of an acqueous solution of 2% Methocel HG-90 (Registered Trade Mark for a non-ionic cellulose ether of hydroxy-propyl methyl-cellulose, manufactured by the Dow Chemical Co.) and 150 cc of water.
B. 120 g of 4.4'-isopropylidenediphenol, 3 g of Tintofen HS-76, 42 g of Dow Latex 636 and 300 cc of water.
48 parts by weight of A and 46.5 parts of B were mixed together, and the resulting mixture was coated on paper, thus obtaining a thermosensitive element which, by heating, gives blue marks of good definition and conservation.
EXAMPLE 10
The following dispersions are separately prepared by charging in a porcelain attritor and grinding as per the preceding Examples:
A. 1 g of Vermillon (Registered Trade Mark for a basic chromogenic substance manufactured by the Nisso Kako Co.), 5 g of Wax C (Registered Trade Mark for an amido was manufactured by Hoechst), 40 g of an aqueous solution of 2% Methocel MC 15 cps (Registered Trade Mark for a methyl-cellulose having a substitution grades in methoxyle 27.5 - 31.5 produced by the Dow Chemical Co.);
B. 8 g of 4.4' -isopropylidenediphenol, 40 g of a 5% solution of Methocel 15 cps and 2.8 grs of Dow Latex 636.
46 parts by weight of A and 50.8 parts of B were mixed together. The temperature-responsive paper prepared by using the above mentioned mixture, gives by selective heating vermillon red marks of good definition and conservation.
It will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention. | 4y
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FIELD OF THE INVENTION
[0001] The present invention relates to an oxide superconductor with a c-axis oriented parallel to a substrate and an a-axis (or b-axis) oriented perpendicular to the substrate, especially to bismuth based (hereunder “Bi-based”) oxide superconductor thin films, specifically Bi 2 Sr 2 Ca 2 Cu 3 O 10±X (where X is a positive number less than unity, hereunder “Bi-2223”) or Bi 2 Sr 2 CuO 6±Y (where Y is a positive number less than unity, hereunder “Bi-2201”), in order to obtain a high performance layered Josephson junction using an oxide superconductor especially a Bi-based oxide superconductor, and a method of manufacturing the same.
[0002] Priority is claimed to Japanese application No. 2005-058246, filed Mar. 2, 2005, and Japanese application No. 2005-099504, filed Mar. 30, 2005, which are incorporated herein by reference.
DESCRIPTION OF RELATED ART
[0003] A feature of a Josephson device, which uses a superconductor, is its high speed operation and low power consumption. When applied to an integrated circuit, it can perform high speed switching with little electric power. In addition to the high speed switching, the Josephson device shows a smaller heat production than a high density integrated circuit, in which heat production is a problem common to semiconductor devices. Therefore, it is expected that the Josephson device exhibits a higher speed operation performance compared to a semiconductor.
[0004] Conventionally, Nb metal or NbN was used as a superconductor in a Josephson device. However, because the superconductive transition temperature is low, the Josephson device was usually operated at a liquid helium temperature of 4.2K. Compared to this, since an oxide superconductor has a higher superconductive transition temperature, a Josephson device using an oxide superconductor can be operated at around a liquid nitrogen temperature, and thus it is favorable from the view of resource and energy saving.
[0005] A superconductive device that shows the Josephson effect is called a Josephson junction. A Josephson junction, which is suitable for constituting an integrated circuit using superconductive devices, is favorable to be manufactured as a layered junction that has a very thin barrier layer of a normal conductor or an insulator inserted between two superconductive thin films as shown in FIG. 1 , as it enables precise dimensional control and the manufacture of many junctions. In practice, a laminated junction is also being used as a Josephson junction in superconductive integrated circuits using Nb metal.
[0006] A problem that requires a breakthrough in order to realize manufacturing of a layered Josephson junction using an oxide superconductor, is closely related to the crystal structure of oxide superconductors. Yttrium based (hereunder “Y-based”) oxide superconductors and Bi-based oxide superconductors have more remarkable anisotropy of superconducting properties such as coherence length, magnetic flux penetration depth, or critical current density, than for conventional superconductors such as Nb.
[0007] The crystals of these superconductors have orthorhombic lattice or tetragonal lattice structure, but the strength of the superconductive coupling in the c-axis direction is weaker than the coupling in the in-plane direction of a surface that is perpendicular to the c-axis. Superconductivity of an oxide superconductor is thought to occur in a CuO plane composed of a copper (Cu) atom and an oxygen (O) atom.
[0008] Therefore, the anisotropy of the superconductive coupling derives from the fact that the CuO plane is oriented perpendicular to a c-axis (namely, in the a- or b-axis direction), and not in the c-axis direction. Accordingly, the coherence length (the inter-electronic distance in which a superconducting electron pair is formed) which is closely related in a Josephson junction, is significantly shorter in the c-axis direction than in the a-axis direction. This tendency is more remarkable in a Bi-based superconductor, whose crystal structure has bigger anisotropy than that of a Y-based superconductor, and the coherence length in the c-axis direction is as short as 0.2 nm.
[0009] Thus, an oxide superconductor, especially a Bi-based superconductor such as Bi-2223 or Bi-2201 has extremely short coherence length in the c-axis direction. Therefore, in order to manufacture a Josephson junction layered in the c-axis direction using c-axis oriented films it is essential to form an even and very thin barrier layer. However, in making a barrier layer very thin, a rough surface caused by deposit and so on becomes a problem, which makes it difficult to form a very thin uniform barrier layer, and which causes current leakage between superconductors sandwiching the barrier layer from each side. Therefore this type of Josephson junction has not been obtained yet. Moreover, even if the Josephson junction can be formed, the Josephson critical current density Jc and the Josephson characteristic parameter IcRn are small, and good characteristics may not be obtained.
[0010] Accordingly, in order to obtain a high performance layered Josephson junction using a Bi-based oxide superconductor, it is essential to manufacture a junction in the non c-axis direction in which the coherence length is longer than in the c-axis direction. Among these directions, the direction in which the coherence length is the longest is the a-axis (or b-axis) direction. Therefore, in order to obtain a high performance layered Josephson junction using a Bi-based oxide superconductor, it is preferable to manufacture a Bi-based oxide superconductor thin film whose c-axis is oriented parallel to the substrate and whose a-axis (or b-axis) is oriented perpendicular to the substrate.
[0011] As one of the methods to realize this, there is known (Japanese Unexamined Patent Application, First Publication No. Hei 5-7027) a method of manufacturing an oxide superconductor film comprising; a step for forming a composition modulated film composed of oxides on a substrate by supplying active oxygen and a part of the metallic components of a Bi-based oxide onto the substrate, and a step for forming an oxide superconductor thin film on the composition modulated film by supplying active oxygen and all of the metallic components of the Bi-based oxide. However, according to this method, the proportion of the c-axis that is parallel to the substrate varies depending on conditions, and it can not be said that a Bi-based oxide superconductor thin film of good quality can be obtained.
[0012] Another method is proposed (Japanese Unexamined Patent Application, First Publication No. Hei 9-246611), where a Josephson device using a Bi-based oxide superconductor thin film whose c-axis is oriented parallel to the substrate and whose a-axis (or b-axis) is oriented perpendicular to the substrate, has excellent performance. However, there is no disclosure of any specific process to obtain the good quality Bi-based oxide superconductor thin film whose c-axis is oriented parallel to the substrate and whose a-axis (or b-axis) is oriented perpendicular to the substrate.
SUMMARY OF THE INVENTION
[0013] Consequently, it is an object of the present invention to manufacture a well-crystallized a-axis (or b-axis) oriented Bi-based oxide superconductor thin film, in order to obtain a high performance layered Josephson junction using a Bi-based oxide superconductor.
[0014] The present invention discloses two embodiments as described below.
[0015] In the first embodiment, an a-axis oriented Bi-2223 thin film is grown by a process where one unit cell of Bi-2223 is in conformity with three units of any one of a single crystal substrate of LaSrAlO 4 having a (110) plane, a single crystal substrate of LaSrGaO 4 having a (110) plane, a single crystal substrate of α-Al 2 O 3 having a (10-10) plane (a-plane), or a single crystal substrate of NdAlO 3 having a (10-10) plane (a-plane).
[0016] In a Bi-2201 thin film, an a-axis oriented Bi-2201 thin film is grown by a process where one unit cell of Bi-2201 is in conformity with two units of any one of a single crystal substrate of either LaSrAlO 4 having a (110) plane, a single crystal substrate of LaSrGaO 4 having a (110) plane, a single crystal substrate of α-Al 2 O 3 having a (10-10) plane (a-plane), or a single crystal substrate of NdAlO 3 having a (10-10) plane (a-plane).
[0017] In a first method of manufacturing a well-crystallized a-axis oriented Bi-based oxide superconductor thin film, a (110) crystal plane of a single crystal substrate of LaSrAlO 4 or the like is used, on which an a-axis oriented Bi-2223 or Bi-2201 thin film is heteroepitaxially grown at a low film forming temperature T 1 (500 to 600° C.), then homoepitaxially grown on the grown film at a high film forming temperature T 2 (650° C. to 750° C.) (double temperature growth method). Normally, if a film is directly formed on a substrate at a high temperature T 2 , a c-axis oriented Bi-2223 or Bi-2201 thin film is grown. However, by previously growing the a-axis oriented Bi-2223 or Bi-2201 thin film on the base, even if a film is formed at an increased substrate temperature, no c-axis oriented film is formed and a well-crystallized a-axis oriented Bi-2223 or Bi-2201 thin film can be manufactured.
[0018] When manufacturing a Josephson device using a well-crystallized a-axis oriented Bi-based oxide superconductor thin film made by the method according to the first embodiment of the present application, it is possible to obtain a Josephson device of extremely high performance.
[0019] In the second embodiment, by using a vicinal substrate cut with a finite angle θ from a (110) plane of a single crystal of LaSrAlO 4 or LaSrGaO 4 or the like, in the direction of [001], or a vicinal substrate cut with a finite angle θ from a (10-10) plane (a-plane) of a single crystal of α-Al 2 O 3 or NdAlO 3 or the like, in the direction of [001], and employing a double temperature growth method, a thin film is formed on the substrate by a step flow growth process in which the starting point is a step of the substrate as shown in FIG. 4 , and a high quality a-axis oriented Bi-2223 thin film having a good superconducting property can be obtained.
[0020] When manufacturing a Josephson device using a high quality a-axis oriented Bi-based oxide superconductor thin film made by the method according to the second embodiment of the present application, it is possible to obtain a Josephson device of extremely high performance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a promising example of a Josephson junction.
[0022] FIG. 2 is an explanatory drawing of a lattice conformity state.
[0023] FIG. 3 shows a model of two dimensional nucleus growth.
[0024] FIG. 4 shows a model of step flow growth.
[0025] FIG. 5 is a conceptual drawing of an MOCVD thin film forming device.
[0026] FIGS. 6A and 6B show thin film X-ray diffraction patterns.
[0027] FIGS. 7A and 7B show atomic force microscope (AFM) images of Bi-2223 thin film surfaces.
[0028] FIGS. 8A and 8B show temperature dependences of resistivity of a-axis oriented Bi-2223 thin films.
[0029] FIGS. 9A to 9 D show atomic force microscope (AFM) images of Bi-2223 thin film surfaces.
[0030] FIGS. 10A and 10B show cross-sections of the Bi-2223 thin films under the atomic force microscope (AFM) images.
[0031] FIGS. 11A and 11B shows temperature dependences of resistivity of the Bi-2223 thin films.
DETAILED DESCRIPTION OF THE INVENTION
[0032] The first embodiment and the second embodiment of the present invention will be described in detail hereinafter.
FIRST EMBODIMENT
[0033] The first embodiment according to the present invention will be described with reference to the attached drawings.
[0034] FIG. 2 shows conformity of lattice constants of a (110) plane of a single crystal substrate of LaSrAlO 4 and lattice constants of a-axis oriented Bi-2223 formed thereon. As shown in FIG. 2 , it is understood that one unit cell of Bi-2223 is in conformity with three unit cells of LaSrAlO 4 extremely well. It is also understood that the misfit of the lattice constants for the a-axis length (or b-axis length) and the c-axis length are −1.48% and 1.61%, respectively, which is extremely small.
[0035] Therefore, on a (110) LaSrAlO 4 single crystal substrate, a Bi-2223 thin film whose c-axis is oriented parallel to the substrate and whose a-axis (or b-axis) is oriented perpendicular to the substrate, can be heteroepitaxially grown. However, at this time, there is a problem in that a well-crystallized thin film cannot be obtained at a low film forming temperature T 1 (single temperature growth method). On the other hand, if a film is formed at a high film forming temperature T 2 from the beginning, a c-axis oriented Bi-2223 thin film is grown regardless of the conformity with the substrate.
[0036] Therefore, on a (110) single crystal substrate of LaSrAlO 4 , firstly an a-axis oriented Bi-2223 thin film is heteroepitaxially grown at a low film forming temperature T 1 , then homoepitaxially grown on the grown film at a high film forming temperature T 2 (double temperature growth method). As a result, even if the film forming temperature is increased, a well-crystallized a-axis oriented Bi-2223 thin film mixed with no c-axis oriented film can be manufactured by a MOCVD thin film forming device shown schematically in FIG. 5 .
EXAMPLE 1
[0037] Using a (110) single crystal substrate of LaSrAlO 4 , a well-crystallized a-axis oriented Bi-2223 superconductor thin film was manufactured by metal-organic chemical vapor deposition (MOCVD). The MOCVD device is shown in FIG. 3 . The film was formed under the following film forming conditions: Bi(C 6 H 5 ) 3 , Sr(DPM) 2 , Ca(DPM) 2 , and Cu(DPM) 2 (DPM: dipivaloylmethan) were used as metal-organic materials while each temperature was maintained at 72° C., 176° C., 161° C., and 80° C., respectively; the Ar carrier gas flow rate was 100, 300, 300, 70 sccm, respectively; the total pressure was 50 torr; the oxygen partial pressure was 23 torr; and the substrate temperature was 555° C. Under these conditions, an a-axis (or b-axis) oriented Bi-2223 thin film was heteroepitaxially grown, and then continually homoepitaxially grown at a temperature as high as the substrate temperature of 677° C. without changing the gas atmosphere.
[0038] The X-ray diffraction patterns of the a-axis oriented Bi-2223 thin films obtained by the single temperature growth method and the double temperature growth method are shown FIGS. 6A and 6B . In either case, as it is clear from the figure, all of the diffraction peaks except for the substrate can be identified as the (n00) or (0n0) plane of the Bi-2223. According to this, it is confirmed that a Bi-2223 thin film whose c-axis is oriented parallel to the substrate and whose a-axis (or b-axis) is oriented perpendicular to the substrate was manufactured.
[0039] In order to compare the crystallizing property of the a-axis oriented Bi-2223 thin films obtained by the single temperature growth method and the double temperature growth method, Table 1 shows half value widths obtained from the X-ray diffraction patterns of FIGS. 6A and 6B . As understood from the table, since the half value width of the double temperature growth method is less than that of the single temperature growth method, it is found that the a-axis oriented Bi-2223 thin film manufactured by the double temperature growth method was better-crystallized than that manufactured by the single temperature growth method.
TABLE 1 Growth method and half value width of X-ray diffraction peak Half value width of single Half value width of double temperature growth method temperature growth method (degree) (degree) (200) 0.32 0.17 (400) 0.27 0.11
[0040] FIGS. 7A and 7B shows atomic force microscope (AFM) images of surfaces of the a-axis oriented Bi-2223 thin films obtained by the single temperature growth method and the double temperature growth method. It is observed that crystal grains in the Bi-2223 thin film of the double temperature growth method are larger compared to those of the single temperature growth method. In this manner, it is found that grain boundaries are reduced and the crystallizing properties are improved by the double temperature growth method.
[0041] FIGS. 8A and 8B respectively shows temperature dependences of resistivity of the a-axis oriented Bi-2223 thin films obtained by the single temperature growth method and the double temperature growth method. Moreover, Table 2 shows the difference in the superconductive transition temperature (Tc) according to the growth method. Measurement was performed by the standard four terminal method. From the results, by using the double temperature growth method, the resistivity at normal conduction was decreased, the temperature dependence became metal-like, the superconductive transition temperature (Tc) was increased, and the superconducting property was improved. This is considered to be because the crystal grains became larger, the crystallizing property was improved, and the effect of weak coupling between grain boundaries was reduced.
TABLE 2 Growth method and superconductive transition temperature (Tc) Single temperature growth Double temperature growth method method Growth T 1 = 555° C. T 1 = 555° C. temperature T 2 = 677° C. Tc <4.2 K 25 K
[0042] As described above, when an a-axis oriented Bi-2223 oxide superconductor thin film is formed, the crystallizing property and the superconducting property of the thin film are improved, in the double temperature growth method where firstly an a-axis oriented Bi-2223 thin film is heteroepitaxially grown on a substrate at a low film forming temperature T 1 , then homoepitaxially grown thereon at a high film forming temperature T 2 , rather than with the single temperature growth at a low film forming temperature T 1 .
SECOND EMBODIMENT
[0043] The second embodiment according to the present invention will be described hereunder.
[0044] As described above, FIG. 2 shows conformity of lattice constants of a (110) plane of a single crystal substrate of LaSrAlO 4 and lattice constants of a-axis oriented Bi-2223 formed thereon. As shown in FIG. 2 , it is understood that one unit cell of Bi-2223 is in conformity with three unit cells of LaSrAlO 4 extremely well. It is also understood that the misfit of the lattice constants for the a-axis length (or b-axis length) and the c-axis length are −1.48% and 1.61%, respectively, which is extremely small.
[0045] Therefore, on a (110) LaSrAlO 4 single crystal substrate, a Bi-2223 thin film whose c-axis is oriented parallel to the substrate and whose a-axis (or b-axis) is oriented perpendicular to the substrate, can be epitaxially grown. However, as shown in FIG. 3 , if a flat substrate is used, nuclei are two-dimensionally grown on the substrate and a large number of grains are formed, making it difficult to obtain a continuous and flat film, and worsening the superconducting property due to a weak coupling between grains. Moreover, by a double temperature growth method only, each grain is merely enlarged, it still being difficult to obtain a continuous and even film, and the superconducting properties are poor.
[0046] Accordingly, by using a vicinal substrate cut with a finite angle θ from a (110) plane of a single crystal of LaSrAlO 4 or LaSrGaO 4 or the like, in the direction of [001], or a vicinal substrate cut with a finite angle θ from a (10-10) plane (a-plane) of a single crystal of α-Al 2 O 3 or NdAlO 3 or the like, in the direction of [001], and employing the double temperature growth method, a thin film is formed on the substrate by a step flow growth process in which the starting point is a step of the substrate as shown in FIG. 4 , and a high quality a-axis oriented Bi-2223 thin film having a good superconducting property can be obtained.
EXAMPLE 1
[0047] Using a vicinal substrate cut with a finite angle θ from a (110) plane of a LaSrAlO 4 single crystal in the direction of [001], a Bi-2223 superconductor thin film was manufactured by metal-organic chemical vapor deposition (MOCVD). The conceptual drawing of the MOCVD device used in this case is shown in FIG. 5 . The film was formed under the following conditions: Bi(C 6 H 5 ) 3 , Sr(DPM) 2 , Ca(DPM) 2 , and Cu(DPM) 2 (DPM: dipivaloylmethan) were used as metal-organic materials while each temperature was maintained at 72° C., 176° C., 161° C., and 80° C., respectively; the Ar carrier gas flow rate was 100, 300, 300, 70 sccm, respectively; the total pressure was 50 torr; the oxygen partial pressure was 23 torr; and the substrate temperature was 553° C. Under these conditions, an a-axis (or b-axis) oriented Bi-2223 thin film was heteroepitaxially grown, and then continually homoepitaxially grown at a temperature as high as the substrate temperature of 680° C. without changing the gas atmosphere. For the film formation in this case, substrates having inclination angles θ of 5°, 10°, and 15° were used.
[0048] FIGS. 9A and 9B show atomic force microscope (AFM) images of surfaces of the a-axis oriented Bi-2223 thin films grown on a flat substrate and a vicinal substrate at the double temperatures.
[0049] FIGS. 10A and 10B show cross-sections thereof. From these it can be confirmed that the a-axis oriented Bi-2223 thin film grown on a vicinal substrate at the double temperatures was formed by a step flow growth process, evenly, and continually.
[0050] FIGS. 11A and 11B respectively shows temperature dependences of resistivity of the a-axis oriented Bi-2223 thin films grown on a flat substrate and a vicinal substrate at the double temperatures. Measurement was performed by the standard four terminal method. Among the films formed in this case, a film having an inclination angle θ of 15° showed the best superconducting properties.
[0051] As described above, when an a-axis oriented Bi-2223 oxide superconductor thin film is formed, growth on a vicinal substrate by the double temperature growth method forms a thin film by a step flow growth process. Therefore a high quality a-axis oriented Bi-2223 thin film having excellent superconducting properties and an even and flat surface, without crystal flow, can be produced.
[0052] While preferred embodiments of the invention have been described and illustrated above, it should be understood that these are exemplary of the invention and are not to be considered as limiting. Additions, omissions, substitutions, and other modifications can be made without departing from the spirit or scope of the present invention. Accordingly, the invention is not to be considered as limited by the foregoing description but is only limited by the scope of the appended claims. | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to a pilot controlled membrane valve for ventilating containers, apparatus or the like, comprising a valve housing having a first valve seat between the inlet and outlet of the housing, first valve means movable between a closed position engaging the first valve seat and an open position and including a first membrane extending transversely through the housing and defining with the latter to one side of the first valve seat a valve chamber which is connected by overpressure passage means to the inlet. The valve includes further a pilot valve having a second valve seat, second valve means including a second membrane and being movable between a closed position engaging the second valve seat and an open position, a second outlet, and means biasing said second valve means to the closed position, wherein the cross section of the second valve seat and that of the second outlet is greater than the open cross-section of the overpressure passage means.
Such valves are employed when use of remote controlled valves is too expensive or for reasons of safety cannot be applied and if, on the other hand, the operating conditions of the valve make it necessary that the pressure at which the valve opens is closely adjacent to the maximum operating pressure and if, in addition, a high degree of sealing up to the region of the valve opening pressure must be provided and/or the valve, after initial opening, must be opened to the maximum extent without increasing the operating pressure.
In a known valve of the above-mentioned construction, the pilot valve is in form of a disc valve which is controlled by membranes. An essential disadvantage of such a construction is in the rather complicated construction of the pilot valve control which is therefore liable to malfunction. This disadvantage is further increased in that, in the known construction, the medium passing through the valve flows around the pilot control mechanism, which may lead to an additional disturbing of its function. This holds especially true if the medium passing through the valve may cause corrosion, soiling or forming deposits on the various elements of the pilot valve. A failure of the pilot valve will lead to a complete breakdown of the valve arrangement, which may entail considerable damage or accidents.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a pilot controlled membrane valve of the aforementioned kind in which the operation of the pilot valve is improved, as compared to such valves known in the art.
It is a further object of the present invention to provide a pilot controlled membrane valve of the aforementioned kind in which the control mechanism of the pilot valve is simplified in its construction so that it will operate trouble-free under extended use.
With these and other objects in view, which will become apparent as the description proceeds, the pilot controlled membrane valve according to the present invention, for ventilating containers or the like, mainly comprises a valve housing having an inlet and an outlet, a first valve seat within said valve housing connected to said inlet, first valve means movable between a closed position engaging the first valve seat and an open position including a first membrane extending transversely through the housing and defining with the latter to one side of the first valve seat a valve chamber, overpressure passage means connecting the valve chamber with the inlet, a pilot valve having a second valve seat in communication with the valve chamber, second valve means including a second membrane and being movable between a closed position engaging the second valve seat and an open position, a second outlet for the pilot valve, means biasing the second valve means to the closed position, and chamber means under atmospheric pressure surrounding the biasing means and separated from the second outlet by the second membrane, in which the cross-section of the second valve seat and that of the second outlet is greater than the cross section through the overpressure passage means.
Since the biasing means for the valve means of the pilot valve are arranged in a chamber, separated from the second outlet by the second membrane and maintained under atmospheric pressure, the fluid medium passing through the valve will not come into contact with these biasing means. Furthermore, since the main valve and the pilot valve are controlled by a membrane, the valve according to the present invention does not require guide elements with close tolerances.
In an advantageous modification of the present invention, the pilot valve may have a surge characteristic, such that the biasing force of the biasing means, which tends to move the second valve means to the closed position, decreases with increasing distance of the second valve means from the second valve seat. This will produce especially advantageous operating conditions, as will be explained, later on, on hand of one of the embodiments disclosed.
In a constructive advantageous form of the present invention, which facilitates servicing of the arrangement, the pilot valve may include a removable valve cap which surrounds the control mechanism, or biasing means of the pilot valve.
For certain operating conditions it may be advantageous to construct the pilot valve as an independent unit, releasably mounted on the valve housing of the main valve. At a malfunction of the pilot valve, respectively if the operating conditions are to be changed, a newly adjusted pilot valve may then be connected to the valve housing of the main valve.
For reasons of safety of operation and protection of the environment, it is advantageous if the outlet of the pilot valve is connected by means of a pressure-equalization tube with the outlet socket of the housing. If this pressure-equalization tube is provided with an adjustable throttle, it is possible to vary the pressure difference between the response pressure and the closure pressure of the valve in a simple manner. In this way a closing pressure can be obtained which is closely adjacent to the response pressure of the valve.
The requirement for quick and complete opening of the main valve at the opening of the pilot valve may be efficiently supported if the pressure equalization tube ends with an ejector opening into the outlet socket of the housing. The suction of gas from the valve chamber will thereby be increased by the produced injector action. In this way it is possible to reduce the cross-section of the pilot valve, respectively the cross-section of its pressure equalization tube with respect to the overpressure passage means between the valve chamber and the inlet socket of the housing.
If the valve is constructed for controlling a fluid medium which tends to lead to deposits of dirt, then it is advantageous that the outlet of the pilot valve is connected with the gas outlet of the housing by means of a large volume connecting chamber.
If in the container or the like, connected to the valve an underpressure below atmospheric pressure can occur and if it is desired that no air will flow in such a case from the surrounding atmosphere into the container, then it is advantageous to provide a check valve in the connection between the valve chamber and the inlet socket of the housing, which will assure that an underpressure in the container or the like will not be transmitted to the valve chamber so that the main valve will remain closed.
The overpressure passage means between the valve chamber and the inlet socket of the housing may also be formed by a pressure equivalization passage in the valve disc of the main valve. In this case air may flow also to containers or the like which are connected to the valve if an underpressure should occur in the connected container or apparatus.
An especially perfect sealing of the valve can be obtained when the valve means comprise a valve disc guided by a membrane and when the seal at the valve seat, at least at the main valve, will be formed by the membrane of the latter. In this case it is advantageous if the membrane of the main valve, opposite the valve chamber in the region of the valve seat of the main valve, is freely movable relative to the valve disc connected thereto. It is thereby especially advantageous when the valve disc of the main valve has a diameter which is smaller than the diameter of the valve seat thereof and in which the arrangement includes a support, preferably adjustable in vertical direction, against which the valve disc of the main valve abuts in the closed position of the valve. If in this construction the valve disc starts to move away from its support, then the membane will still abut, at the beginning of a small movement of the valve disc, against the valve seat and be pressed on thereon due to the pressure in the valve chamber. This will be especially advantageous when, for instance for the reason of chemical stability, relatively hard materials have to be used for the valve seat, respectively the membrane. In this case, the membrane is pressed, by the pressure acting thereon, onto the outer edges of the valve seat, whereby the sealing effect is increased.
If the valve has to handle especially critical products, especially products which lead to crystallizing, polymerization or sublimation, it is advantageous to provide heating coils in the interior of the valve housing. Such heating coils have thereby to be arranged so that all elements of the valve, which are impinged by the fluid medium, will be sufficiently heated.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1-4 respectively illustrate vertical cross-sections of four different embodiments of pilot controlled membrane valves according to the present invention;
FIG. 5 illustrates on an enlarged scale a detail of FIG. 1 in vertical cross-section; and
FIG. 6 illustrates a vertical cross-section of a detail of FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawing and more particularly to FIG. 1 of the same, it will be seen that the valve according to the present invention illustrated therein comprises a valve housing 3, provided with an inlet or inlet socket 1 and an outlet or outlet socket 2. The valve housing 3 encloses a first valve seat 4 of the main valve, as well as a valve chamber 5 located above the valve seat 4.
The first valve means of the main valve, illustrated in FIGS. 1 and 5, comprises a first valve disc 6 and an annular first membrane 7 clamped at its inner and outer periphery respectively to the valve disc 6 and the valve housing 3. Contrary to the usual arrangement, the membrane 7 serves not only to guide the valve disc 6, but serves also as a seal of the valve means on the valve seat 4. As can be clearly visualized from FIG. 5, the annular portion of the membrane 7, opposite the valve chamber 5 in the region of the valve seat 4, is freely movable with respect to the valve disc 6 and is thereby at this region impinged by the pressure of the valve chamber 5, as indicated by the arrows, at the right side of FIG. 5, to be thereby securely pressed onto the valve seat 4. Pressure equalization passage means in form a central opening 8 in the valve disc 6 connect the inlet socket 1 with the valve chamber 5.
The valve housing 3 forms at its upper end a second valve seat 9 for the pilot valve 10. The valve means of the pilot valve 10 likewise comprise a second valve disc 11 to which the inner periphery of a second membrane 12 is connected, whereas the outer periphery of the membrane is held on the valve housing 3 by a pilot valve cap 13, releasably connected thereto. In this way, the control mechanism for the pilot valve, that is the mechanism which biases the valve means of the pilot valve to the closed position, is located in a pilot valve chamber 14 which is securely sealed off from the pilot valve outlet 15 by the second membrane 12 and which may be maintained under atmospheric pressure by an opening in the cap 13. The pilot valve outlet or second outlet 15 is connected by means of a pressure equivalization tube 16 with the outlet socket 2 of the valve housing and the tube 16 ends in the latter with an injector port 17.
The biasing means which biases the second valve means 11, 12 to the closed position may be constituted by a weight 18, as shown at the left half of FIG. 1, or, alternatively, by a compression spring 19, as shown at the right half of this Figure.
A container or the like, not shown in the drawing, is fluid-tightly connected to the inlet socket 1 of the housing into which a gaseous fluid may pass if the pressure in the container is lower than atmospheric pressure or pressure maintained at the outlet 2, or from which fluid may be discharged when the pressure in the container is greater than atmospheric pressure or pressure at the outlet 2 of the valve housing. Through the pressure equivalization passage means or opening 8 in the valve disc 6, a pressure will be established in the valve chamber 5 equal to the pressure in the container or the like connected to the inlet socket 1. Since the surface area of the valve means 6, 7 facing the valve chamber 5 is greater than that facing the inlet socket 1, the valve means 6, 7 will, at overpressure, be securely pressed against the valve seat 4. When the pressure in the connected container or the like and therewith the pressure in the valve chamber 5 reaches the response pressure of the pilot valve 10, the latter will open. The pressure in the valve chamber 5 will then decrease over the opened pilot valve 10 and the pressure equalization tube 16, so that an overpressure will form below the first valve disc 6 to open the main valve. This function is assured when the cross-section of the second valve seat 9 of the pilot valve 10 and that of the pressure equalization tube 16 is greater than the cross-section of the pressure equivalization passage means 8 in the valve disc 6.
The pilot valve control mechanism or biasing means 18 or 19 of the pilot valve, which is important for the proper function of the valve arrangement, is located in the pilot valve chamber 14 through which no fluid medium controlled by the valve will pass and which may be maintained at atmospheric pressure. By removing the pilot valve cap 13, the response pressure of the pilot valve 10 may be varied, by change of the weight 18 or by adjusting the spring 19, without interruption of the function of the valve arrangement.
FIG. 2 illustrates a second embodiment according to the present invention in which the pilot valve 10 has a surge characteristic. The adjustment of the response pressure of the pilot valve 10 is in this case not provided by biasing means in form of a weight and/or in form of a spring, but the pilot valve includes in this embodiment a stationary permanent magnet 20 cooperating with an armature 21 connected to the valve disc 11 of the pilot valve. If the response pressure of the pilot valve 10 is reached, the valve disc 11 of the pilot valve starts to move away from its valve seat so that the distance between the permanent magnet 20 and the armature 21 is increased. Thereby the force exerted by the permanent magnet onto the armature will instantaneously and rapidly decrease and the pilot valve will open with a surge characteristic instantaneously to its maximum extent, when the response pressure for the pilot valve is reached. Thereby the pressure in the valve chamber 5 will simultaneously rapidly decrease so that the main valve will also rapidly open to the full extent.
By use of a pilot valve of the aforementioned kind, it is possible to obtain a valve arrangement of simple construction in which, when the response pressure of the pilot valve is reached, the main valve opens instantaneously to its maximum extent. This result is further improved by the use of membrane controlled valve discs, in which the surface at which the fluid pressure acts increases correspondingly at the start of the movement of the valve disc from the respective valve seat.
The pilot valve 10 is preferably dimensioned in such a manner that in order to reach its fully opened flow-cross section only a relatively short valve stroke is necessary. From this results, in the embodiment shown in FIG. 2, only a small change in the distance between permanent magnet 20 and the armature 21. At a small decrease of the operating pressure below the pressure of response of the pilot valve, the armature 21 will approach again the permanent magnet 20 so that the closing force of the pilot valve is increased. In this way the response pressure of the valve will come close to the closure pressure. By providing an adjustable throttle 22 in the pressure equalization tube 16 it is additionally possible to vary the pressure difference between the pressure of response and the closure pressure.
In the embodiments shown in FIGS. 2 and 3, it is not only possible to obtain an overpressure function, that is an exhaust of the container or the like connected to the valve, but also an underpressure function in which gaseous fluid may flow into the connected container. Since in the valve chamber 5 the same underpressure will prevail as in the container or the like connected to the inlet 1, the pressure in the outlet socket 2 will act on the lower face of the membrane 7 of the main valve and lift the latter when the product of pressure and surface area is equal to the weight of the valve disc 6 of the main valve. Since the response pressure of the pilot valve 10 is usually greater than the weight loaded response pressure of the main valve, the pilot valve 10 will remain closed during flow of gaseous fluid into the container or the like connected to the inlet socket 1 of the valve housing 2. The pilot valve control of the embodiments shown in FIGS. 1 and 2 will therefore not act, if an underpressure is maintained in the connected container or the like, so that in this case a direct weight loaded membrane valve is obtained.
In practice it is often required that the pressure of response for exhaust of gaseous fluid from a container or the like connected to the valve is relatively high, whereas in the case an underpressure is prevailing in the container or the like connected to the valve, the response pressure should be low. However, since the first valve seat 6 of the main valve has necessarily a minimum weight, which, in the valve construction shown in FIG. 5, would influence the response pressure in the case in which an underpressure is maintained in the connected container or the like, it may be advantageous to form the first valve disc 6 of the main valve in the manner as illustrated in FIGS. 3, 4 and 6. In these constructions the diameter of the first valve disc 6 of the main valve is smaller than that of the first valve seat 4, and in which the valve disc 6 in the closed position of the main valve abuts against a support 23, which is adjustable in vertical direction relative to the valve seat 4. In this construction only the very light membrane 7 will act as weight, in the case an underpressure is maintained in the container or the like connected to the valve arrangement, so that an opening will be assured by a pressure difference of only a few millimeters water column.
If, however, flow of gaseous fluid into the container or the like connected to the valve arrangement is not desired, then the valve member 5 may be connected to the inlet socket 1 by a bypass conduit 24 in which a check valve 25 is provided.
In the embodiment shown in FIG. 4, the pilot valve outlet 15 is connected to the outlet socket 2 by means of a connecting chamber 26 of large volume. This connection is better suitable than the pressure equalization tube 16 with relatively small cross section, if the valve is used for controlling flow of a gaseous medium tending to produce deposits of dirt. Heating coils 27 are also arranged in the embodiment shown in FIG. 4 through which all elements, which are impinged by the fluid medium passing through the valve, may be heated.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of pilot controlled membrane valves differing from the types described above.
While the invention has been illustrated and described as embodied in a pilot controlled membrane valve, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can be applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | 4y
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This application is a continuation of PCT/CA98/00731 filed Jul. 30, 1998 designating the United States and claiming priority of U.S. Provisional Patent Application Ser. No. 60/054,543 filed Aug. 1, 1997 (now abandoned).
BACKGROUND OF THE INVENTION
(a) Field of the Invention
The invention relates to compounds which exhibit anti-KS and anti-HIV activity, pharmaceutical compositions and method of treatment thereof.
(b) Description of Prior Art
Kaposi's sarcoma (KS) is the most common tumour in AIDS subjects which afflicts high mortality (Friedman-Kien A E et al., 1990 , J Am Acad Dermatol 22:1237-1250). Less aggressive forms can also occur in non-AIDS subjects of the Mediterranean area and equatorial Africa as well as in renal transplant patients following treatment with immunosuppressive drugs (Friedman-Kien A E et al., 1990 , J Am Acad Dermatol 22:1237-1250). The pathogenesis and therapy of KS remain enigmatic (Bais C. et al., 1998 , Nature 391:86). For unknown reasons, occurrence of KS is higher in males than in females. For example, in the West, approximately 95% of AIDS-KS subjects are men. Although, hormonal dependence of KS has been demonstrated in the case of glucocorticoid and retinoid (Guo W X et al., 1996 , Am J Pathol 148: 1999-2008; Guo W X et al., 1995 , Am J Pathol 146: 727-734; Guo W X et al., 1995 , Cancer Res 55: 823-829), sex steroids do not seem to be directly involved in KS pathogenesis. Recently, Lunardi-Iskandar et al. (Lunardi-Iskandar Y et al., 1995 , Nature 375: 64-68) reported that the placental hormone human chorionic gonadotropin (HCG), displays anti-KS activity and prevents tumours in immunodeficient mice. This preliminary finding could otentially have significant therapeutic impact as demonstrated in clinical trials (Gill PS et al., 1996 , New Engl J Med 335: 1261-1310; Gill P S et al., 1997 , J. Natl. Cancer Inst . 89: 1797) and may shed light on basic understanding of this disease particularly regarding the sexual dimorphism issue. Though the role of HCG is principally to sustain pregnancy, it is becoming increasingly apparent that this hormone, possibly along with other active molecules, may be responsible for numerous other phenomena. The low transmission rate of HIV across the placenta (Prober C G et al., 1991 , Ped Infect Dis J 10: 684-695) as well as the low incidence of Kaposi Sarcoma in women including those previously infected with the virus has led to the suspicion that pregnancy and/or reproductive hormones (such as related LH, see Lunardi-Iskandar Y et al., 1995 , Nature 377: 21-22) may be involved in curtailing the propagation of the virus. Studies by Bourinbaiar (Bourinbaiar AS et al., 1995 , Immunol Lett 44: 13-18) indicate that the hormone HCG or its β subunit may have an anti-HIV effect. The action of HCG on gonadal cells is mediated by a G-protein coupled trans-membrane receptor which interacts with the dimeric hormone (α and β complex) with very high affinity and specificity (review Segaloff D L et al., 1993 , Endocr Rev 14: 324-347). In such a system, it is very well known that either one of the individual α and β subunits have extremely low reactivity towards the membrane bound receptor (Pierce J G et al., 1981 , Ann Rev Biochem 50: 465-495; Sairam M R, 1983 , In: Hormonal Proteins and Peptides . Li C. H., ed., pages 1-79) but complete activity can be regained by appropriate (1:1) recombination of the two subunits. Lunardi-Iskandar's and Bourinbaiar's data (Lunardi-Iskandar Y et al., 1995 , Nature 375: 64-68; Bourinbaiar A S et al., 1995 , Immunol Lett 44: 13-18) suggest the involvement of an “unconventional” mode of action for HCG in KS. In fact, they reported a biological activity for the β HCG, a notion which contradicts the generally accepted paradigm that the dimeric form of the hormone is required for triggering hormonal responses in classical target tissues. While stirring a controversy (Lunardi-Iskandar Y et al., 1995 , Nature 377: 21-22; Berger P et al., 1995 , Nature 377: 21; Rabkin C S et al., 1995 , Nature 377: 21-22; Krown S E, 1996 , New Engl J Med 335: 1309-1310), these findings raise intriguing and potentially novel issues.
There is reported in Nature Medicine (Vol. 4, No. 7, July 1998) that the anti-KS activity of crude hCG preparations is still a mystery.
It would be highly desirable to be provided with compounds which would exhibit anti-KS and anti-HIV activity.
SUMMARY OF THE INVENTION
One aim of the present invention is to provide with compounds which would exhibit anti-KS and anti-HIV activity.
In accordance with one preferred embodiment of the present invention there is provided a compound having anti-KS and anti-HIV pharmaceutical activity which comprises an RCG-like inhibitory protein and fragments thereof, the protein and fragments thereof are isolated from a biologically active fraction of APL™-HCG (“APL™” is the commercial trade name of the clinical-grade HCG sold by Wyeth-Ayerst), wherein said protein has a molecular weight of about 3,500 or of about 13,000 Dalton, and wherein said protein and fragments thereof are adsorbed to polypropylene plastic supports, such as tubes or pipette tips among others.
A preferred polypropylene plastic tube includes those sold by Sarstedt (Numbreht, Germany) cat #57.512 and cat #68.752.
In accordance with another preferred embodiment of the present invention there is provided purified protein and derivatives and fragments thereof having anti-KS and anti-HIV pharmaceutical activity which is a HCG-like inhibitory protein and derivatives and fragments thereof which are adsorbed to polypropylene plastic supports, and wherein said protein has an amino acid sequence selected from the group consisting of:
Ser-Lys-Glu-Pro-Leu-Arg-Pro-Arg-Glu-Arg-Pro-Ile-Asn*-Ala-Thr-Leu-Ala-Val-Glu-Lys SEQ ID NO:1; and
Ala-Pro-Asp-Val-Gln-Asp-Lys-Phe-Thr-Arg-Gln-Ile-Met-Ala-Thr SEQ ID NO:2.
The purified protein of the present invention is referred to as HIP or HCG-like Inhibitory Protein.
In other embodiments, the derivatives contain one or more D-amino acids or non-natural amino acids.
In accordance with another preferred embodiment of the present invention there, is provided a pharmaceutical composition for the prevention and/or treatment of Kaposi's sarcoma (KS) and/or HIV which comprises a therapeutically effective amount of at least one compound of the present invention in association with a pharmaceutically acceptable carrier.
In accordance with another preferred embodiment of the present invention there is provided a pharmaceutical composition for the prevention and/or treatment of Kaposi's sarcoma (KS) and/or HIV which comprises a therapeutically effective amount of at least one protein of the present invention in association with a pharmaceutically acceptable carrier.
In other embodiments, the pharmaceutical composition is formulated as a controlled release formulation.
In accordance with another preferred embodiment of the present invention there is provided a pharmaceutical composition for the prevention and/or treatment of Kaposils sarcoma (KS) and/or HIV which comprises a therapeutically effective amount of a derivative of a protein having anti-KS and anti-HIV pharmaceutical activity which is a HCG-like inhibitory protein which is adsorbed to polypropylene plastic supports, and wherein said protein has an amino acid sequence selected from the group consisting of:
Ser-Lys-Glu-Pro-Leu-Arg-Pro-Arg-Glu-Arg-Pro-Ile-Asn*-Ala-Thr-Leu-Ala-Val-Glu-Lys SEQ ID NO:1; and
Ala-Pro-Asp-Val-Gln-Asp-Lys-Phe-Thr-Arg-Gln-Ile-Met-Ala-Thr SEQ ID NO:2
in association with a pharmaceutically acceptable carrier.
In accordance with another preferred embodiment of the present invention there is provided a method for the prevention, treatment and/or reduction of Kaposi's sarcoma and/or HIV expression in AIDS patients, which comprises administering to said patient a therapeutically effective amount of a compound of the present invention.
In accordance with another preferred embodiment of the present invention there is provided a method for the prevention, treatment and/or reduction of Kaposi's sarcoma and/or HIV expression in AIDS patients, which comprises administering to said patient a therapeutically effective amount of a protein of the present invention.
In accordance with another preferred embodiment of the present invention there is provided a method for the prevention, treatment and/or reduction of Kaposi's sarcoma and/or HIV expression in AIDS patients, which comprises administering to said patient a therapeutically effective amount of a pharmaceutical composition of the present invention.
In accordance with another preferred embodiment of the present invention there is provided a method to purify the compound or protein of the present invention, which comprises the steps of:
a) subjecting a biologically active fraction of APL-HCG or urinary extract containing said compound or protein to a polypropylene plastic support for a time sufficient for adsorption of said compound or protein to occur; and
b) washing the support and releasing the adsorbed compound or protein therefrom.
In accordance with another preferred embodiment of the present invention there is provided a method of evaluating inhibitory activity of anti-KS and anti-HIV compound, which comprises by measuring AP1 gene activity.
In other embodiments, measuring of said AP1 gene activity is effected by measuring binding to DNA response element.
For the purpose of the present invention the following terms are defined below.
“HIP”: HCG-like Inhibitory Protein;
“HPLC”: high-pressure liquid chromatography; and
“APL”: commercial trade name of the clinical-grade HCG sold by Wyeth-Ayerst, cat. #DIN 02168936.
The expression “derivatives and fragments thereof” is intended to mean any derivatives and fragments of the protein of the present invention which exhibit anti-KS and anti-HIV pharmaceutical activity effective for the prevention, treatment and/or reduction of Kaposi's sarcoma in AIDS patients. The derivatives may include one or more D-amino acids or non-natural amino acids. The derivatives and fragments are functional and substantially exhibit the biological activity of the protein of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the effect of HCG from different commercial sources on KS-Y1 cell proliferation;
FIG. 2 illustrates the fractionation and activity profile of APL-HCG;
FIG. 3 illustrates the time-course effect of APL-HCG on inhibition of AP-1 binding in KSY-1 cells;
FIG. 4 illustrates the purification of the HIP using reversed phase-HPLC;
FIG. 5 illustrates the bioassay of the collected fractions following HPLC separation;
FIG. 6 illustrates the analysis of fraction D by mass spectrometry; and
FIG. 7 illustrates the analysis of fraction A+B+C+E by mass spectrometry;
FIG. 8 illustrates the analysis of another low molecular weight fraction by mass spectrometry;
FIG. 9 illustrates the effect of HIP on HIV expression; and
FIGS. 10A and 10B illustrate potential partial sequences of the purified HIP protein of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Kaposi's sarcoma (KS), a sexually dimorphic disease inflicting high mortality in AIDS, remains at present without effective treatment. A recent report (Lunardi-Iskandar Y et al., 1995 , Nature 375: 64-68) showed that the placental glycoprotein hormone, human chorionic gonadotropin (HCG), and surprisingly its β subunit, inhibit tumorigenicity and metastasis of Kaposi's sarcoma cells in mice xenografts. The anti-KS efficacy of a commercial HCG was subsequently demonstrated in clinical trials (Gill P S et al., 1996 , New Engl J Med 335: 1261-1310; Gill P S et al., 1997 , J. Natl. Cancer Inst . 89: 1797). In addition, earlier studies by Bourinbaiar (Bourinbaiar, A. S. et al., 1992 , FEBS. Lett . 309: 82-84; Bourinbaiar A S et al., 1995 , Immunol Lett 44: 13-18) and by Gallo's group (Lunardi-Iskandar Y et al., 1998 , Nature Medicine 4:428-434) indicate that the β subunit of HCG (or peptides derived thereof) have anti-HIV effects.
The Applicants have been working for several years on the cellular and molecular aspects of KS regulation by hormones. Recent studies in the Applicants' laboratory confirm that commercial HCG preparations (known to be about 25% pure) display significant inhibitory action in a dose-dependent manner. However, pure and biologically active HCG has no effect on Kaposi's sarcoma growth in culture suggesting that a contaminant (or degradation product) may be the active agent.
The Applicants have subfractionated commercial HCG preparations based on molecular size and each fraction was tested with respect to inhibition of KS cell growth, HCG radioreceptor binding and steroidogenic bioactivity. The Applicants' results demonstrate that the anti-KS activity resides among low molecular weight components, and not in bona fide (macromolecular) HCG. Interestingly, the Applicants have identified a transcription factor which may be the target for regulation by the anti-KS components. The Applicants have concluded that, as yet unidentified molecules, present in the commercial HCG preparations, are responsible for the growth inhibitory effects wrongfully attributed to HCG.
Surprisingly, and in accordance with the present invention, there is provided the identification of a purified HIP protein having anti-KS and anti-HIV pharmaceutical activity. This protein is an HCG-like inhibitory protein and is adsorbed to polypropylene plastic supports, and has an amino acid sequence selected from the group consisting of:
Ser-Lys-Glu-Pro-Leu-Arg-Pro-Arg-Glu-Arg-Pro-Ile-Asn*-Ala-Thr-Leu-Ala-Val-Glu-Lys SEQ ID NO:1; and
Ala-Pro-Asp-Val-Gln-Asp-Lys-Phe-Thr-Arg-Gln-Ile-Met-Ala-Thr SEQ ID NO:2.
Sources of HCG
Two commercial HCG samples were tested. The first one, under the trade name of APL, was provided by Wyeth-Ayerst, Montreal (Lot #C84662A was generously donated and cat. #DIN-02168936 was purchased), it should be emphasized that APL was used in the earlier studies (Lunardi-Iskandar Y et al., 1995 , Nature 375: 64-68; Gill P S et al., 1996 , New Engl J Med 335: 1261-1310). Two samples were also purchased from Sigma, St-Louis, Mo. (lot #26H 1040). Pure HCG dimer as well as α-HCG and β-HCG were obtained from NIDDK (Bethesda, Md.). Recombinant HCG was obtained from Organon, Oss, the Netherlands. All HCG samples, previously stored lyophilised, were dissolved in PBS and frozen as aliquots.
Assessment of Cell Proliferation
The KS-Y1 (Lunardi-Iskandar Y et al., 1995 , Nature 375: 64-68) was isolated from an HIV-patient while the subline designated N-1506 (Lunardi-Iskandar Y et al., 1995 , Nature 375: 64-68) of the original KS-SLK cell line originated from an immunosupressed subject (Herndier B G et al., 1994 , AIDS 8: 575-581). These cell lines were provided by Dr. Lunardi-Iskandar (N. I. H., Bethesda) . The KS cells were passaged and the culture medium was changed every other day in presence or in absence of any of the HCG samples mentioned above for the indicated periods ranging from 24-96 hrs. 3 H-thymidine incorporation was measured as described (Guo W X et al., 1996 , Am J Pathol 148: 1999-2008; Guo W X et al., 1995 , Am J Pathol 146: 727-734) In most experiments, data are reported as means±SEM of quadruplet determinations. Statistical analysis was determined by student t-test.
Fractionation of APL on SEPHADEX™ G-100
Three vials of APL (10 000 IU/vial) were pooled for fractionation by dissolving in 1.5 ml of 0.05 M NH 4 HCO 3 . The clear solution was loaded on a column of SEPHADEX™ G-100 (“SEPHADEX™” G-100″ are beads for gel filtration preparation prepared by cross linking dextran with epichlorohydrin, available from Pharmacia, Baie d'Urfé, Qc) (1.5×90 cm) equilibrated in the same solvent. Fractions of 1.7 ml were collected and pooled into seven fractions (see FIG. 3 ). A small portion of each was saved for estimating HCG equivalent activity and the remainder was lyophilized.
HCG Receptor Binding Activity
A convenient test for HCG, a hormone which efficiently binds to the LH receptor, is to perform radioreceptor assays using membrane preparations of adult pig testes as described in detail (Sairam M R, 1983 , In: Hormonal Proteins and Peptides . Li C. H., ed., pages 1-79; Manjunath P et al., 1982 , J Biol Chem 257: 7109-7115). Standard (CR-125 HCG from NICHD, Bethesda) or test samples were tested for 125 I-HCG binding as described (Sairam M R, 1983 , In: Hormonal Proteins and Peptides . Li C. H., ed., pages 1-79). The total binding activity in each of the seven fractions was calculated and expressed as, ug HCG equivalent per fraction.
Steroidogenic Activity
HCG is a highly potent steroidogenic hormone, therefore one reliable bioassay consists of incubating mouse Leydig tumour cells (MA-10, originally obtained from Dr. M. Ascoli, Iowa) with the test material as described (Sairam M R, 1983 , In: Hormonal Proteins and Peptides . Li C. H., ed., pages 1-79). Progesterone in the medium was estimated by radioimmunoassay (Sairam M R, 1983 , In: Hormonal Proteins and Peptides . Li C. H., ed., pages 1-79).
Electrophoretic Mobility Gel Shift Assay (EMSA)
Nuclear extracts were prepared from KSY-1 cell cultures according to the original procedure of Smeal (Smeal T et al., 1989 ,. Genes Develop . 3:2091-2100). Binding reactions for AP-1 sites (TRE, TPA Response Element) were carried out as described (Smeal T et al., 1989 ,. Genes Develop . 3:2091-2100, and reviewed in Saatcioglu F et al., 1994 , Semin. Cancer Biol . 5:347-359). Synthetic collagenase TRE oligonucleotide probe of the sequence 5′-GGATCCGATGAGTCAGCCA-3′ (SEQ ID NO:5) was end labelled with 32 P-ATP and EMSA performed as described (Sineal T et al., 1989 ,. Genes Develop . 3:2091-2100). Specificity was ascertained by using. 100 molar excess of unlabelled TRE. The signal was quantified by phosphorimager analysis using the software by Molecular Dynamics (Sunnyvale, Calif.).
Pure HCG Has no Inhibitory Activity in KS Cells (FIG. 1 )
Initial experiments were designed to confirm the inhibitory action of HCG. The effects on the two different KS cell lines were compared. In cells pre-treated with a commercial HCG preparation (Sigma or APL) an inhibitory effect was elicited (p<0.05) in all KS cell lines. In preliminary experiments a dose-dependent inhibition of cell growth was noted.
The two commercial HCG products (APL and Sigma) were tested, and near identical inhibition was obtained (FIG. 1 ), right-hand two bars). However, some HCG shipments were more potent than others.
Samples were used at an equivalent concentration of 50 U/ml (FIG. 1 ). Note that upon treatment with Sigma-HCG (S) or Ayerst-HCG (APL), KS cell growth was significantly reduced as compared with the vehicle-treated cells (C). In contrast, no inhibitory effect was noted using preparations of highly purified HCG. Legend: 1=dimeric HCG; 2=α HCG; 3=β HCG; 4=unrelated human urinary protein pool; *p<0.05.
Next, the anti-KS activity of a well characterized, pure dimeric HCG, pure α or β subunits and recombinant HCG was verified. Neither one of these pure HCG's inhibited KS growth (FIG. 1, #1-3). The biological activity of these compounds was examined by induction of steroidogenesis in cultured Leydig cells. As expected, either recombinant or pure HCG elicited the classic biological responses, while neither α nor β HCG displayed any steroidogenic action.
Molecular Sieving of Crude HCG (FIG. 2 )
Generally, the pregnancy hormone ampouled into vials for clinical use is only about 25% pure for HCG as evaluated by biological activity and biochemical analyses (Manjunath P et al., 1982 , J Biol Chem 257: 7109-7115). The commercial HCG (APL) was sorted into 7 distinct fractions using SEPHADEX™ chromatography (FIG. 2 ).
The contents of 3 vials of clinical grade APL (10,000 IU each) were dissolved in 0.05 M NH 4 HCO 3 and subjected to molecular sieving on a column of SEPHADEX™ G-100 (1.5×90 cm). The eluted protein/peptide fractions monitored at A230 nm (panel E) were separated into seven pools identified as fraction pools #1-7 on the X-axis. A total of 120 tubes (1.75 ml/tube) were collected. Lyophilized material in each pool was reconstituted in KS culture medium (without serum), and evaluated for cell proliferation (panel A). HCG receptor binding in pig testicular membranes (panel B) and steroidogenic activity in MA-10 cells (panel C) were determined. Panel D: bar graphs show quantitative densitometric scanning of AP-1 binding and insert shows the actual EMSA protein-DNA complexes of fractions (fr) 2,4 and 7; nd=not determined. KSY-1 cells were treated with the indicated reagents at an equivalent concentration 100 U/ml for 4 days. Note clear segregation of HCG hormone activity on gonadal cells (pool 2) and inhibitory action on KS cells (pool 7) *p<0.05.
Over 85% HCG receptor binding activity (FIG. 2B) was recovered in the first two pooled fractions where high molecular weight proteins of the size of pure HCG would emerge. The Ve/Vo ratio of the early major fraction (pool #2) corresponded to bona fide HCG. These fractions may also contain the hormone subunits (α/β) or their degraded products in addition to other unidentified materials present in the crude extract. Fraction #7 consists, as shown in previous studies (Sairam M R, 1983 , In: Hormonal Proteins and Peptides . Li C. H., ed., pages 1-79), of relatively small peptides along with other agents present in the APL formulation. Either the steroidogenic or the binding activity that is characteristic of HCG (but not its subunits) was highest in the 2nd fraction (FIGS. 2 B and C). These results are consistent with receptor binding assays in which only the dimeric (α-β combined) HCG but not the individual subunits or their cleaved products are biologically active (Sairam M R, 1983 , In: Hormonal Proteins and Peptides . Li C. H., ed., pages 1-79; Manjunath P et al., 1982 , J Biol Chem 257: 7109-7115). On the contrary, only fraction #7 contained KS inhibitory activity.
Down-regulation of AP-1 Binding by HCG Components (FIG. 3 )
Activating protein-1 (AP-1) is a transcriptional activator which is induced by 12-O-tetradecanyl phorbol-13-acetate (TPA) tumor promoter, several growth factors and various extracellular stimuli (reviewed in Saatcioglu F et al., 1994 , Semin. Cancer Biol . 5:347-359). AP-1 consists of proteins of jun and fos families which associate to form homo-(jun/jun) or heterodimers (jun/fos) and recognize a consensus sequence 5′-TGA G/C TCA-3′ known as TPA Response Element (TRE) present on AP-1 regulated genes. AP-1 complexes are considered to play important roles in several signal transduction pathways such as growth stimulation, differentiation, neuronal excitation and transformation (Saatcioglu F et al., 1994 , Semin. Cancer Biol . 5:347-359). APL-HCG and components in fraction 7 significantly inhibited AP-1 binding to TRE in KSY-1 cells (FIG. 2 D). APL-HCG inhibited AP-1 binding by 1.5, 3 and 2 fold respectively after 3, 6 and 12 hours of treatment (FIG. 3 ).
Cells were incubated with 50 IU/ml APL-HCG (+) or with vehicle (−) for the indicated time periods (FIG. 3 ). Nuclear extracts were prepared and EMSA was performed. Results shown are representative of three experiments. Arrow-head points to free probe. 100ex.=100 fold excess unlabelled probe. Top shows the actual gel shifts while bottom panel provides quantitative phosphorimager measurement of the major band (arrow); * denotes p<0.05 as compared to vehicle-treated.
A dose-response was also observed with near maximal effect noted at approximately 100 IU/ml. Therefore, repression of AP-1 may be an important pathway by which inhibition of KSY-1 cells occurs.
Purification of the HIP Using Reversed Phase-HPLC (FIG. 4 )
APL was purchased from Wyeth-Ayerst Cat. #DIN 02168936 and shipped in an insulated box packed with refrigierant Upon receipt, APL was stored at 4° C. One APL vial (which contained the dried product) lot #JA(L)3YYF-AB was reconstituted with one (1) ml of the solvent sold with the APL ampoule at room temperature and processed for HPLC within one hour. The powder was readily dissolved resulting in a homogeneous “solution”. This “solution” was injected into a Water™ HPLC apparatus fitted with a 7.8×300 mm C-18™ columnn Elution from the column was done using an increasing linear isocratic gradient of acetonitrile in water containing 0.1% trifluoroacetic acid. The gradient was increased from 5% to 75% acetonitrile. The absorbancy was monitored at 220 wavelength during the elation and fractions were collected manually in siliconized polypropylene tubes. When regular (i.e. non-siliconized) tubes were used it was later found that biological activity was lost After collection, the fractions were immediately placed in a Savant™ Speed-vac apparatus in order to dry the samples. The gradient is drawn on FIG. 4; the right-side or Y axis shows the % acetetonile (%B; B: 80% acetonitrile in water containing 0.1% trifluoroacetic acid) and the X axis indicates time, in minutes. The absorbency at 220 nm was recorded and recorded on the Y axis. The two peaks (D & E) indicated by arrows were subsequently found (see FIG. 5 below) to contain the KS inhibitory activity.
Bioassay of the Collected Fractions Following HPLC Separation (FIG. 5 )
The fractions (peaks) indicated by arrows on FIG. 4 . were lyophilized and each was reconstituted in one (1) ml of RPMI culture medium (without serum) and tested for biological activity using the KS-Y1 cells. Since the original material was supplied as 10 000 IU of HCG, by analogy, it was assumed arbitrarily that one of the fractions should contain arbitrarily 10,000 IU of anti-KS activity. With such an assumption, the doses were evaluated throughout the present application. The biological activity was tested in absence (0) or presence of different doses (10, 100 & 200 IU/ml) . The fraction indicated as “mix” represents one pool made by mixing equivalent amounts of fractions A-E. It can be seen from FIG. 5 that fractions D, E and “Mix” display an inhibitory activity.
Analysis of the Active Fractions (HIP) by MALDI-TOF Mass Spectrometry (FIGS. 6 and 7 )
Briefly, an aliquot of each sample was embedded in a low molecular weight UV-absorbing matrix (α-cyano-4-hydroxycinnamic acid) to enhance sample ionization and then subjected to MALDI-TOF (Matrix Assisted Laser Desorption Ionization Time of Flight) mass spectrometry on a Voyager-Delayed Extraction system (Perseptive Biosystem, Framingham, Mass.).
One major peak can be observed containing moieties at approximately 13000 Dalton (FIG. 6 ). For comparison purposes, the spectrometric analysis of fractions A-C and E are also shown (FIG. 7 ), note that the 13000 Dalton species is found in both fractions D and E (FIG. 6 ).
Effect of HIP on HIV Expression (FIG. 9 )
The low molecular weight fraction #7 shown earlier to inhibit KS cell proliferation (Kachra et al., 1997 , Endocrinology , 138:4038-4041), was tested for its anti-HIV activity. Primary cultured human lymphocytes were infected with the virus HIV-IIIB as described (Tremblay et al., 1994 , Embo. J . 13:774). Immediately following infection, cells were treated with the test material (HCG fractions or recombinant HCG) daily for 10 days at the indicated dose ranging from 1 to 250 IU equivalent. Subsequently, cells were lysed and assayed for the expression of the HIV viral protein p24 as described (Tremblay et al., 1994 , Embo. J . 13:774). It can be noted that p24 expression is markedly reduced upon treatment with high doses of the fraction containing HIP while recombinant HCG displays no significant affects (FIG. 9 ).
Sequencing of the Proteins Contained in the HIP Fractions (FIGS. 10 A and 10 B)
Following the HPLC separation, the fractions were tested for biological activity as described above (for FIGS. 4 and 5 ). Two fractions which contains highest bioactivity were processed for protein sequencing using an automatic sequencing apparatus (Applied Biosystem gas phase sequencer model 470 updated to 475). An internal standard was used consisting of pTH-Nor-Leu. The initial yield efficiency was approximately 50±20 pmoles. After 15 cycle runs, data generated was examined using customary protein analysis. The deduced amino acid sequences were compared with published databases of the GenBank™. It was found that the two sequences contained significant homology with the α- and β-subunits of hCG.
CONCLUSION
The present results provide evidence for the existence of a potentially important compound which inhibits the growth of KS possibly through signalling by the AP-1 pathway. Although the sequencing of the purified active molecule is currently in progress, it is evident that it is neither HCG nor any of its classically unknown subunits.
Judging from its gel permeation chromatographic elution, its size is relatively small and probably less than 10,000-14,000. To obtain further resolution, the technique of HPLC was employed resulting in a separation of protein species into discrete and distinct peaks. Specific individual peaks were found to contain the anti-KS activity. To obtain further data, individual peaks were analyzed by polyacrylamide gel electrophoresis followed by silver staining. In instances where proteins was visualized, a “fuzzy” band was observed, indicating that the proteins comprise closely related species.
At this time, one can only speculate as to whether it is derived from HCG as a cleavage peptide. Indeed, it is known that glycoprotein hormones are metabolized to smaller polypeptides (Sairam M R, 1983 , In: Hormonal Proteins and Peptides . Li C. H., ed., pages 1-79). The putative cleavage (or related product) could elicit its action via a modified HCG receptor. In fact, the HCG receptor gene is known to be expressed as alternatively spliced variant transcripts (Segaloff D L et al., 1993 , Endocr Rev 14: 324-347) in a developmentally regulated manner raising the possibility that the putative product could mediate different aspects of hormone action. Such a hypothesis is further strengthened by parallel experiments showing that KS tissues and cell lines express significant levels of HCG receptors whose size and intracellular distribution are different from classical targets cells (Cao H., Sairam M. R. and Antakly T., Abstract #1543, Annual meeting, American Association for Cancer Research, 1996). Alternatively, the active substance could be a degradation product of the β-HCG subunit (such as but not limited to P-core) which is homologous in three-dimensional structure to several growth factors (Lapthorn A J et al., 1994 , Nature 369: 455-461). Since the initiation and proliferation of KS cells is largely growth factor-dependent, it is possible that β-core fragments act as antagonists for growth factor receptors (reviewed in Guo W X et al., 1996 , Am J Pathol 148: 1999-2008).
The partial sequences obtained in accordance with the present invention support the view that HIP proteins may be derived from hCG either as: 1) alternate expression of α- or β-subunit; or 2) enzymatic processing of the hCG subunits.
While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth, and as follows in the scope of the appended claims.
4
1
20
PRT
Artificial Sequence
anti-KS and anti-HIV compound
1
Ser Lys Glu Pro Leu Arg Pro Arg Cys Arg Pro Ile Asn Ala Thr Leu
1 5 10 15
Ala Val Glu Lys
20
2
13
PRT
Artificial Sequence
anti-KS and anti-HIV compound
2
Ala Pro Asp Val Gln Asp Lys Phe Thr Arg Gln Ile Met
1 5 10
3
15
PRT
Artificial Sequence
anti-KS and anti-HIV compound
3
Ala Pro Asp Val Gln Asp Lys Phe Thr Arg Gln Xaa Met Xaa Xaa
1 5 10 15
4
20
PRT
Artificial Sequence
anti-KS and anti-HIV compound
4
Ser Lys Glu Pro Leu Arg Pro Arg Xaa Arg Pro Ile Asn Ala Thr Leu
1 5 10 15
Ala Val Glu Lys
20 | 4y
|
FIELD OF THE INVENTION
The present invention relates generally to optical networks. More particularly, the present invention relates to a method and apparatus for auditing the network to identify the operational parameters of network elements and create an audit report.
BACKGROUND OF THE INVENTION
An optical network consists of a number of interconnected elements operating in the synchronous optical network (SONET) layer and optical layer of the network, all of which must be operating correctly and within valid operating parameters. It is especially important that all elements be operating correctly before performing a software upgrade or network reconfiguration. This requires that an audit be performed upon each of the elements in the network.
Creating a network audit report comprises three major processes. The first of these processes typically involves the gathering of network element information by capturing network element information files from the command line user interface (CLUI) of each element. The second involves the evaluation of the captured network element information files to determine if “findings”—i.e. elements which are outside valid operating parameters—have occurred due to performance or configuration issues. The final process calls for the findings to be recorded in a formal report that lists the findings, a probable cause, and corrective procedures. The formal network audit report, upon completion, is submitted to the customer.
A serious problem arises in the second process, namely, the evaluation of the captured network element information files. An experienced engineer familiar with all operating aspects of the network element's configuration and software load can spend upwards of 40 minutes analyzing the data to determine if a network element is operating within properly configured bounds and a typical network may contain 30 to 40 elements.
One approach to addressing this problem is the Preside™ Software Upgrade Management tool of Nortel Networks Corporation. This utility performs a pre-check of the network element s before attempting to perform software upgrade or network reconfiguration. However, the Preside™ tool only performs three checks on the network element and only identifies that a problem exists, not the reason or cause of the problem. It also requires experienced personnel to then troubleshoot the network element to determine what the problem is, which may require three to four hours to completely evaluate a network of 30 to 40 nodes. It further requires an IP address and uses TCP/IP as its means of communicating with the network elements, whereas personnel troubleshooting a network element typically use a modem connection in order to access the network element. Moreover, most network elements do not have an IP address, making them invisible to Preside™. Furthermore, since more than one operations controller can control the network elements in a network, Preside™ must discover what span of control each operations controller has and whether or not the network element is within that operations controller's span of control, if TCP/IP is to be used to communicate to the network element through the operations controller.
It is, therefore, desirable to provide a method of auditing a network to identify the operational parameters of network elements, particularly malfunctioning network elements, and to generate a report which allows skilled personnel to quickly and effectively identify areas of functionality of a deployed network element that is operating incorrectly by reading through the report. This could then be used to determine if the network elements that make up a network's topology are ready for a network reconfiguration or upgrade. If any of the network elements are identified as having a “finding” then those network elements are evaluated and corrective measures effected before a software upgrade or network reconfiguration is executed. Otherwise, the software upgrade or network reconfiguration can fail.
SUMMARY OF THE INVENTION
It is an object of the present invention to obviate or mitigate at least one disadvantage of previous systems and methods for auditing optical networks. In particular, it is an object of the present invention to automate an auditing function, and to generate a report that identifies malfunctioning network elements in a readily understandable format.
In a first aspect, the present invention provides a method of auditing an optical communications network to determine operational states of network elements. The method consists of first retrieving operational data from a plurality of network elements. The data can be retrieved by polling the network elements via a serial connection, using, for example, a modem, or by accessing static data capture files. Next, the operational data is evaluated to determine an operational parameter for a given network element. In a presently preferred embodiment, the operational data is evaluated by processing network interface command lines within data capture files. If the operational parameter is determined to be invalid, it is flagged as an invalid operational parameter. To determine if the operational parameter is invalid, it can be compared to predetermined operational specifications for the given network element. If the operational parameter falls outside a predetermined operating range, it is considered invalid. The evaluation and determination steps are repeated for all operational parameters related to the given network element, and then again for each remaining network element. Once the evaluation is completed, a findings report is generated. The findings report lists any of the plurality of network elements determined to have at least one invalid operational parameter, displays details of each invalid operational parameter, and provides a finding status for each invalid operational parameter.
In a further aspect, there is provided a method of auditing a synchronous optical network to identify malfunctioning network elements, and a computer program product embodying the method. The method commences with entering a directory location for network element data files. The network element data file for a given network element is then retrieved from the directory location, and verified as valid. The valid file is then opened and a network interface command line is read. If the network interface command line is valid, it is processed to determine if operational parameters for the given network element are outside valid predetermined operating ranges. Any operational parameters so determined are flagged and stored in a network element findings file. These steps are repeated for each network element, and a summary findings file is created that encapsulates the network element findings files to provide a report listing any of the plurality of network elements determined to have findings, displaying details of the findings, and providing a finding status for each finding. A computer program product, residing on a computer useable medium and embodying this method is also provided.
In yet another aspect, the present invention provides a computer program product, residing on a computer-useable medium, for auditing an optical communications network to determine operational states of network elements. The computer program product includes a data capture module stored on the computer-useable medium for retrieving operational data from a plurality of network elements via a serial connection, and for storing the operational data in data capture files. An evaluation module is communicatively coupled to the data capture module. The evaluation module evaluates the operational data to determine operational parameters for the plurality of network elements, determines if the determined operational parameters are invalid, and flags the invalid operational parameters. A reporting module communicatively coupled to the evaluation module generates a findings report for the plurality of network elements. The findings report lists any of the plurality of network elements determined to have at least one invalid operational parameter, displays details of the at least one invalid operational parameter, and provides a finding status for the at least one invalid operational parameter.
In still a further aspect, the present invention provides an auditor for auditing an optical communications network to determine operational states of network elements. The auditor consists of a serial connection for communicating with a plurality of network elements in an optical communications network, and a data capture module for retrieving operational data from the plurality of network elements via the modem. The data capture module also stores the operational data in data capture files. An evaluation module evaluates the operational data to determine operational parameters for the plurality of network elements, and to determine if the determined operational parameters are invalid. If the operational parameters are invalid, they are flagged. A reporting module can then generate a findings report for the plurality of network elements. The findings report lists any of the plurality of network elements determined to have at least one invalid operational parameter, displays details of the at least one invalid operational parameter, and provides a finding status for the at least one invalid operational parameter.
Other aspects and features of the present invention will become apparent to those ordinarily skilled in the art upon review of the following description of specific embodiments of the invention in conjunction with the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described, by way of example only, with reference to the attached Figures, wherein:
FIG. 1 is a block diagram of an optical communications network showing typical SONET and optical layer elements, connected to an auditor of the present invention;
FIG. 2 is a flowchart illustrating the method of the present invention; and
FIG. 3 is a flowchart of an embodiment of the method of FIG. 2 .
DETAILED DESCRIPTION
Generally, the present invention provides a method and system for auditing an optical communications network, at the SONET and optical layers. An auditor, embodied in a software application, queries, or polls, each network element using a modem connection to collect data related to each element, determines if each element is operating within expected operational parameters, and creates a report that permits a user to view the operational parameters associated with each network element, and identify those elements that may be malfunctioning. Preferably, the auditor examines all the data that is present for each network element, judges the data as valid or invalid, and generates a report, or summary, that indicates those instances where a network element's operational parameters are judged to be invalid. A user is then able to study the audit report to determine which network elements are not performing as expected. The auditor of the present invention is intended to operate on all network elements that are running software loads and to determine if an element is operating within established parameters based on the specifications provided for each given software release. While the invention is described herein in terms of SONET elements and optical network elements, it will be understood by those of skill in the art that present invention can be applied to other network element types that have software loads and can be polled remotely, or can download their operational data or operational parameters to readable data structures.
FIG. 1 shows a typical optical communications network 20 , including SONET network elements 22 , and optical elements 24 that transport signals at the optical layer. An auditor 26 according to the present invention, is in communication with the optical communications network 20 via a serial connection, such as a modem connection. The SONET elements 22 can include regenerators, add/drop multiplexers (ADMs), line terminating equipment, dense regenerators, 4-fiber ring (4FR) ADMs, TMux network elements, etc. The optical elements 24 can include optical amplifiers, optical switches, etc.
In a presently preferred embodiment, the auditor 26 is a command line driven application program that can be run from an Xterm window or a DOS shell prompt. The auditor 26 is embodied as software residing on a general purpose, or other suitable, computer having memory means, a modem connection to a desired optical network, and standard peripherals such as a monitor, a printer, and input and output devices. The software embodying auditor 26 can be provided on any suitable computer-useable medium for execution by the computer, such as CD-ROM, hard disk, read-only memory, or random access memory. In a presently preferred embodiment, the application software is written in a suitable programming language, such as C++. Auditor 26 generally consists of a data capture module 28 , an evaluation module 30 , and a reporting module 32 , the operation and interaction of which are described below.
Referring to FIGS. 1 and 2, the general operation of the auditor 26 is shown. At step 100 , the auditor 26 retrieves data concerning the operational parameters of network elements in a network of interest. The data can be captured directly by polling the network elements and the captured information stored in a data capture file, or it can be retrieved from static data capture files stored in a main network administrative directory location. The static data capture files are typically downloaded to the main administrative directory location at regular intervals, e.g. daily. The auditor 26 can, if desired, verify that the data capture files are of a valid type before continuing.
At step 102 , the auditor 26 opens the data capture file for a given network element and reads it. While reading the network element data capture file, the auditor 26 determines if the line read is a valid network element command line instruction. If the line read is a valid network element command line instruction, the auditor 26 processes all of the information associated with that command, at step 104 , according to the guidelines set out for the particular transport platform in applicable standards for the particular network element. The parameters evaluated at step 104 are next examined to determine if they are within expected ranges at step 106 . Parameters that are outside the valid ranges are flagged as a “Finding”, and written to a findings file for the network element at step 108 , and then proceeds to the next command line, if any, at step 110 . The result of each evaluation is flagged as “OK”, for parameters that are within valid operating ranges, and the method proceeds to the next command line instruction at step 110 . This process repeats from step 104 for each command line instruction for the network element. When the command line instructions for the particular network element have been exhausted, the auditor 26 determines if there are more network elements to examine, at step 112 , and repeats steps 102 to 110 for each network element in turn. Once the auditor 26 determines that all of the network element data capture files have been examined, it summarizes all of the findings files and creates a findings summary file at step 114 .
Referring to FIGS. 1 and 3, the following is an example of the operation of the auditor 26 described above for an OC-192 network, such as the S/DMS TransportNode™ OC-192 system of Nortel Networks Limited. Upon prompting by the auditor 26 , the user enters the directory location where the network element data files are located and the auditor 26 prompts the user to verify that the directory location is correct, as shown at step 200 . If the directory location is not correct, the user is prompted to re-enter the directory location and verification is again requested. If the user replies affirmatively, the auditor 26 retrieves the network element data file from directory at step 202 and determines if a file located in the directory location specified by the user is a valid SONET network element data capture file, or some other unrelated file at step 204 . This is done by, for example, examining the output stored in the CLUI eq ne qrne output, which accesses the card configuration within the shelf inventory of the network element. Although the network element may identified as a valid type, the configuration of the cards in the network element shelf may have been changed by the customer. The auditor 26 therefore uses the cards listed in the network element's shelf inventory to confirm the network element's functionality. For example, if the network element is identified as a regenerator, then the shelf inventory will be queried to determine if a circuit pack of type Rgn exists. If it is found to be an unrelated file, the auditor 26 ignores it and proceeds to retrieve the next network element data file. If the file is a valid network element data file, the utility then opens and reads the file at step 206 .
The network auditor 26 then creates, at step 208 , a findings file for the network element being examined. The evaluation results of the parameters collected from the network element data file are subsequently written to this findings file. While reading the network element data file, the auditor 26 determines if the line read is a valid network element user interface command. If the line read is a valid command line, the auditor 26 calls the subroutine associated with that particular command line instruction, and processes all of the information associated with that command according to the guidelines set out by the network audit specification for the particular transport platform, and determines which parameters are within valid operating ranges, as shown at steps 210 and 212 . The result of the evaluation is flagged as “OK”, for parameters that are within valid operating ranges, or “Finding”, for parameters that are outside the valid ranges described and is written to the respective findings file at step 214 .
After completing the analysis of the network element's captured operational data, the auditor 26 continues to open, read, evaluate and write the status of the results of the evaluation to the respective finding files for each of the network elements in the directory specified by the user. The auditor 26 determines whether all of the network element data files have been examined and if they have not, steps 202 to 212 are repeated. Once the auditor 26 determines that all of the network element data files have been examined, it creates a findings summary file at step 216 .
The findings summary file is created by the auditor 26 opening each of the finding files created for the network elements evaluated, and determining if the status of the evaluation is listed as either “OK” or a “Finding”. If the status of the evaluation is listed as “OK”, the auditor 26 ignores this reported evaluation. If the status of the evaluation is listed as a “Finding”, the evaluation result is copied to the finding summary file along with the data from the network element data file that shows the invalid parameter in-situ.
Once the auditor 26 has summarized the findings reported in each of the network element finding files, it closes the finding summary file, at step 218 , and prompts the user, at step 220 , to continue or terminate the audit. If the user indicates that be or she is finished using the auditor 26 , the program is terminated. If the user indicates that he or she wants to continue using the auditor 26 , the auditor 26 prompts the user to supply the location of the directory where the next set of network element data files are located and returns to step 200 .
A typical summary findings report for a single network element, NE 30063, is shown at Appendix “A”. As will be understood by those of skill in the art, a full summary findings report can include findings for a number of network elements, and can run to many pages. Typically, the summary findings report is displayed on an appropriate computer monitor, saved to a text file, and/or printed out as a hardcopy. The particular format of the summary findings report depends on the needs of the user. A graphical representation the summary findings report, as opposed to, or as a supplement to, the illustrated textual report, is also fully within the contemplation of the inventors. Such a graphical representation would provide the user with a visual identification of malfunctioning network elements, and could use colours or other indicators to identify particular invalid operational parameters.
Briefly, the illustrated summary findings report includes an identification of the network element in question, including, for example, its address and location within the network, and then displays each finding for the network element, as determined by the auditor 26 . The display of the finding includes details of the invalid operational parameters detected for the finding, and a finding status that summarizes the detected error condition and provides an indication of the expected valid operational range for the given operational parameter. For example, looking at the first page of Appendix “A”, the finding status for a first operational parameter morf pwrm disptpgll red is displayed as “LOS threshold value −20 is not 3 to 4 dB below the total input power value −11.9 and is invalid”. The details of the finding are presented in tabular form, as appropriate to the particular operational parameter. Findings for each flagged operational parameter are presented, in turn, in the report.
As will be understood by those of skill in the art, the auditor of the present invention permits users, such as product support personnel and field support personnel, to quickly generate an audit report for a network. The comprehensive nature of the report, as well as the fact that only findings for network elements that have an identified abnormality are presented, means that a user can quickly pinpoint problem areas in the network, and, due to the organized and uniform manner in which the information is presented, likely determine the root cause of the problems. The present auditor can also be used to screen networks prior to reconfigurations or upgrades to permit deficiencies to be corrected prior to the reconfiguration. In this way, it is more likely that any network reconfiguration will proceed smoothly.
In tests on data capture files for an OC-192 network, the auditor of the present invention has been found capable of analyzing a single network element in less than seven seconds. This is compared to an average of forty minutes that it would take an experienced engineer to analyze the same operational data to determine if the element is working within established operational bounds. Thus the present auditor provides a nearly 350 times performance increase, and eliminates human error.
The auditor of the present invention can also be used for training purposes to permit users to become familiar with the operation of a network and to see the types of problems that can occur.
The auditor can also, if desired, be incorporated with other network system tools, such as a network plotter, to provide a comprehensive package for network management.
The above-described embodiments of the present invention are intended to be examples only. Alterations, modifications and variations may be effected to the particular embodiments by those of skill in the art without departing from the scope of the invention, which is defined solely by the claims appended hereto.
APPENDIX A
Example Summary findings report
NETWORK AUDIT FINDING SUMMARY
***** 30063 ***** 30063 ***** 30063 ***** 30063 ***** 30063 ***** 30063 *****
Status: Finding - OPC server address is undefined.
Status: Finding - OPC server directory value undefined is invalid.
NE 30063> showserver
Server Address:
undefined
Server Directory:
undefined
Status: Finding - LOS threshold value −20 is not 3 to 4 dB below the total input
power value −11.9 and is invalid.
NE 30063> morf pwrm disptp g11 red
Shelf: 2 Slot: 12 Unit. MOR G11
Red Band (1547.50-1561.00 nm)
Current
(Last)
Power Measurements
dBm
%
(dBm
%)
Input Red Power
−12.9
78
(−
−)
Reflected Blue Power
−19.3
18
(−
−)
Input OSC Power
−25.7
4
(−
−)
Total Input Power
−11.9
100
(−
−)
Output Red Power
10.2
93
(−
−)
Output OSC Power
−0.7
7
(−
−)
Input Blue Power
−13.1
87
(−
−)
Reflected Red Power
−21.7
12
(−
−)
Reflected OSC Power
−32.7
1
(−
−)
Total Input Power
−12.5
100
(−
−)
Total Output Power
10.3
100
(−
100)
Input LOS Threshold =
−20 dBm
Input Shut-off Threshold =
−26 dBm
Blue Input/Red Output Optical Reflectometer = Enabled
Last saved at 00:00 00/00/00
Press CR to return to menu
Status: Finding - LOS threshold value −20 is not 3 to 4 dB below the total input
power value −11.3 and is invalid.
NE 30063>morf pwrm disptp g12 red
Shelf: 2 Slot: 13 Unit: MOR G12
Red Band (1547.50-1561.00 nm)
Current
(Last)
Power Measurements
dBm
%
(dBm
%)
Shelf: 2 Slot: 13 Unit: MOR G12
Blue Band (1528.40-1542.50 nm)
Current
(Last)
Power Measurements
dBm
%
(dBm
%)
Input Blue Power
−14.0
85
(−
−)
Reflected Red Power
−21.9
14
(−
−)
Reflected OSC Power
−33.0
1
(−
−)
Total Input Power
−13.3
100
(−
−)
Total Output Power
10.6
100
(−
100)
Input LOS Threshold =
−20 dBm
Input Shut-off Threshold =
−26 dBm
Blue Input/Red Output Optical Reflectometer = Enabled
Last saved at 00:00 00/00/00
Press CR to return to menu
Status: Finding - Save value 00:00 00/00/00 invalid.
NE 30063> morf pwrm dispch g11 red
Shelf: 2 Slot: 12 Unit: MOR G11
Red Band (1547.50-1561.00 nm)
Shelf: 2 Slot: 12 Unit: MOR G11
Blue Band (1528.40-1542.50 nm)
Input Power
Output Power
Current
(Last)
Current
(Last)
Ch Tx - Wavelength
dBm
%
(dBm
%)
dBm
%
(dBm
%)
1 OC-192
−13.3
82
(−
−)
10.1
95
(−
−)
DWDMTx 1533.47
2 -
−
−
(−
−)
−
−
(−
−)
3 -
−
−
(−
−)
−
−
(−
−)
4 -
−
−
(−
−)
−
−
(−
−)
OSC
−
−
(−
−)
−
−
(−
−)
Reflected Red
−21.7
12
(−
−)
Reflected OSC
−32.8
1
(−
−)
Residual
−25.6
5
(−
−)
−2.5
5
(−
−)
Total
−12.5
100
(−
−)
10.3
100
(−
−)
Last saved at 00:00 00/00/00
Press CR to return to menu
Status: Finding - Save value 00:00 00/00/00 invalid.
NE 30063> morf pwrm dispch g12 red
Shelf: 2 Slot: 13 Unit: MOR G12
NE 30063> morf pwrm dispch g12 blue
Shelf: 2 Slot: 13 Unit: MOR G12
Blue Band (1528.40-1542.50 nm)
Input Power
Output Power
Current
(Last)
Current
(Last)
Ch Tx - Wavelength
dBm
%
(dBm
%)
dBm
%
(dBm
%)
1 OC-192
−14.4
78
(−
−)
10.2
91
(−
−)
DWDMTx 1533.47
2 -
−
−
(−
−)
−
−
(−
−)
3 -
−
−
(−
−)
−
−
(−
−)
4 -
−
−
(−
−)
−
−
(−
−)
OSC
−
−
(−
−)
−
−
(−
−)
Reflected Red
−21.9
14
(−
−)
Reflected OSC
−33.0
1
(−
−)
Residual
−25.2
7
(−
−)
0.3
9
(−
−)
Total
−13.4
100
(−
−)
10.6
100
(−
−)
Last saved at 00:00 00/00/00
Press CR to return to menu
Status: Finding - Current saved hour 00:00 and current saved date 00/00/00 are
invalid.
Status: Finding - Last saved hour 00:00 and last saved date 00/00/00 are
invalid.
Optical Reflectometer
Red In/Blue Out
Blue In/Red Out
Current
(Last)
Current
(Last)
Output Optical Return Loss
30.4 dB
(−dB)
32.1 dB
(−dB)
Optical Return Loss
24 dB
24 dB
Threshold
Optical Reflectometer State
Enabled
Enabled
Last Saved at
00:00 00/00/00
00:00 00/00/00
Press CR to return to menu
Status: Finding - Alarm log record created in the last 48 hours.
NE 30063> ad 11r EQP*
Type
Date
Time
Count
Description
EQP421
01/03/99
13/57/44
5
Card Insert
EQP422
01/03/99
13/52/57
3
Card Remove
EQP401
01/03/99
13/37/36
20
Create/Delete
EQP403
00/00/00
00/00/00
0
Data Change
EQP501
00/00/00
00/00/00
0
CPG Primary state change
EQP323
00/00/00
00/00/00
0
INFO Protection Activity
EQP410
05/05/99
05/05/55
66
Audit Report
EQP411
00/00/00
00/00/00
0
Audit Report
EQP405
00/00/00
00/00/00
0
EQP MX protection exerciser result
EQP616
00/00/00
00/00/00
0
Reconfiguration Operation Success
EQP316
00/00/00
00/00/00
0
Reconfiguration Operation Failed
5
Entry to 20 ppm freerun
On
On
6
Filler card missing
On
Off
7
Autoprovisioning mismatch
On
On
8
Duplicate NE name
On
On
9
Duplicate NE ID
On
On
10
NE approval required
On
On
11
Number of level 1 NEs exceeded
On
On
12
MI port intrusion attempt
On
On
13
LCAP port intrusion attempt
On
On
14
Serial number inconsistency
On
On
15
Mismatched switch types
On
On
16
Shelf autoprovisioning mismatch
On
On
17
MX exerciser fail
On
On
18
Manual area address dropped from area
On
On
19
PM day MS/line/RS/section threshold
On
On
20
PM 15 min MS/line/RS/section threshold
On
On
21
PM 15 min path threshold
On
On
22
PM day path threshold
On
On
23
PM physical TCA
On
On
24
Protection path fail
On
On
25
Fan 1 fail
On
On
26
Fan 2 fail
On
On
27
Fan 3 fail
On
On
28
High shelf temperature
On
On
29
Low shelf voltage
On
On
30
Fan 1 missing
On
On
31
Fan 2 missing
On
On
32
Fan 3 missing
On
On
33
Breaker filter A fail
On
On | 4y
|
This application is a contiuation of Ser. No. 09/004,437 filed Jan. 8, 1998 now U.S. Pat. No. 6,158,467.
FIELD OF THE INVENTION
The present invention relates to a stopcock for use in intravenous injections and infusions, and more particularly to a stopcock having four fluid flow ports and providing four ways for fluid to flow, including two fluid flow paths capable of flowing simultaneously.
BACKGROUND OF THE INVENTION
A stopcock is a cock or valve for stopping or regulating the flow of a fluid (wherein the term “fluid” as used herein may include liquids and/or gasses). In medicine, a stopcock is most typically used for regulating the flow of intravenous (“IV”) fluids or medications into, or out of, a patient as part of an intravenous system. A stopcock can also be used to divert fluids or air into devices, such as for filling skin expanders with fluid or air during skin grafting, for filling breast implants with saline during breast augmentation procedures, for diverting spinal fluid into a manometer to measure spinal fluid pressure during a spinal tap, and for diluting viscous packed red blood cells with saline to make them less viscous for subsequent rapid infusion into the patient during transfusions.
Stopcocks have been in use in the practice of medicine for intravenous injection and infusions for more than 30 years. They provide a quick and sterile way for diverting intravenous fluid flow or medication into a patient by changing the flow path in the IV line system.
In the past six years, stopcocks have been used with increasing frequency as a needle-less intravenous injection port. That is, once the initial IV injection port has been opened using a first needle, subsequent injections and infusions are possible through the same injection port via a stopcock having three ports separated by a shut off valve. Stopcocks provide an inexpensive method of avoiding needle-stick injuries and for a clinician to comply with the FDA mandate “to use needle-less injection techniques whenever possible”.
The first stopcocks used in medicine were made out of metal. They were re-sterilized and used on other patients. With the refining of plastic injection molding techniques, inexpensive, disposable plastic stopcocks have become the state of the art. They are disposed of after use on a single patient. The disposable plastic stopcock is cost effective and helps prevent spread of diseases between patients.
Early stopcocks were simply used as “on and off” valves to start or stop intravenous infusions. They contained two ports, an inlet port and an outlet port, which were placed in a straight line. There was a shut off lever in the middle of the two ports, and fluid flowed one way. These first stopcocks were designated as two-port, one-way stopcocks.
Another prior art stopcock has a body with three ports which are arranged in a T-shaped configuration, and a core having a lever and an axial portion. The channels and ports can be selected at the option of the user by rotating the lever to a position determined by the direction of flow desired. There is a “stop” tab on the body part of these stopcocks which prevents the lever of the stopcock from being turned to a position where all three ports are open and flow into one another at one time, i.e., such that the T-shaped path of the body and the T-shaped path of the core are fully aligned. Because fluid can flow three different ways, these stopcocks are designated as three-port, three-way stopcocks.
Referring to FIG. 1A, the prior art stopcock 2 is a three-port, four-way stopcock. It does not have a stop tab as in the three-port, three-way stopcock to prevent the lever from being turned to a position opposite the right angled port. The stopcock 2 includes a body 4 having an entry port 6 , an exit port 8 and an injection port 10 , and a core 12 . The body 4 and the core 12 are molded as two separate parts and press-fit together to make a completed three-port, four-way stopcock 2 . The core 12 includes a rotating axial portion 14 connected to a lever 16 .
Referring to FIG. 1 B and FIG. 1C, the axial portion 14 of the core 12 has a first flow channel 18 , a second flow channel 20 and a third flow channel 22 which form a confluent “T” configuration. The lever 16 generally includes the word “off” 24 and an arrow 26 molded on its upper surface to show which direction fluid will not flow. The arrow 26 and the word “off” 24 do not directly indicate to the user which way the medication or fluid will flow.
The three-port, four-way stopcock 2 is a four-way stopcock because fluid can flow in four different ways. First, when the lever 16 points toward the entry port 6 , fluid can flow between the injection port 10 and exit port 8 . Second, when the lever 16 points toward the injection port 10 , fluid can flow between the entry port 6 and exit port 8 . Third, when the lever 16 points toward the exit port 8 , fluid can flow between the entry port 6 and injection port 10 . Finally, when the lever 16 points opposite the injection port 10 , i.e., toward no port, fluid can flow between all three ports 6 , 8 , 10 at one time.
Referring to FIG. 2, the body 4 of the three-port, four-way stopcock 2 is molded as one piece. The entry port 6 , exit port 8 and injection port 10 are located in a single horizontal plane and are confluent at a central chamber 28 , which is filled with the axial portion 14 of the core 12 when the stopcock 2 is assembled. The entry port 6 has a female luer lock connector 30 and is the main fluid entry end of the stopcock 2 . It usually is connected to a male luer-lock connector 32 from an IV set connected to a bag of IV fluid. The exit port 8 has a male luer lock or luer slip connector 32 and is the fluid exit end of the stopcock 2 and is usually connected to a female luer lock connector 30 of an IV extension set which ultimately connects to the IV catheter in the patient. The injection port 10 protruding perpendicularly from the middle of the straight line flow path formed by the entry port 6 and exit port 8 has a female Luer lock connector 30 and is used for adding medication or fluids to the IV system.
Referring to FIG. 3, the axial portion 14 and the lever 16 are molded as one piece in a right angle configuration to form a completed core 12 . The lever 16 rotates in a horizontal plane which is parallel to the horizontal plane formed by the three fluid flow ports 6 , 8 and 10 .
The procedure a clinician must follow to perform a typical IV injection or infusion using a conventional three-port, four-way stopcock 2 is fraught with difficulty and risk. An examination of this procedure makes clear the need for an improvement, such as that of the present invention described further below.
A typical intravenous setup using a three-port, four-way stopcock 2 has the exit port 8 typically connected to an IV extension tubing which is subsequently connected to an IV catheter in the patients vein. The entry port 6 is connected to a main IV administration set which is in turn connected to a bag of IV fluid, and the injection port 10 normally has a syringe or a secondary IV fluid line connected to it. When a syringe is attached to the injection port 10 , the bulk and length of the syringe requires that the syringe-stopcock assembly sit on a surface wherein a single plane is formed by the slow ports 6 , 8 , 10 of the stopcock 2 and the attached syringe. The axial portion 14 then extends vertically upward from, and the lever 16 rotates in a plane parallel to, that surface. To turn the lever 16 in a desired direction, a first hand of a clinician is held palm up in a horizontal plane, with the fingers pointing upward in a vertical direction, to stabilize the syringe-stopcock assembly, and a second hand of the clinician is held above the lever 16 , with fingers pointing in a downward, vertical direction, for grasping and rotating the lever 16 .
This arrangement is awkward for the clinician. With the first hand below and the second hand above the stopcock 2 , the clinician must first determine which way to turn the lever 16 to obtain the desired fluid flow, and then he or she must turn it in the correct direction, either clockwise or counter-clockwise, with fingers of the second hand. When the clinician is assured that the stopcock is secure in the grasp of the first hand only, the second hand releases the lever 16 and grasps the barrel of the syringe attached to the injection port 10 . The second hand then pushes or pulls the plunger of the syringe to give an injection of medication or to aspirate fluid. The second hand must next move from the syringe barrel back to its previous position grasping the lever 16 of the stopcock 2 and rotating it back to its original position. This procedure is cumbersome and time consuming, and involves twice moving one hand between two perpendicular planes.
Referring to FIG. 4, there is shown another prior art stopcock. This stopcock is designated a four-port, three-way stopcock 34 . Fluid can flow in three different ways. First, the fluid may flow between an entry port 36 , an exit port 38 , and a first lateral port 40 , simultaneously. Second, fluid may flow between the entry port 36 , exit port 38 and second lateral port 42 simultaneously. Third, fluid may flow between the entry port 36 and exit port 38 only. The stopcock 34 comprises a body 44 assembled with core 46 . The core 46 has an axial portion 48 and a lever 50 . The axial portion 48 sits partially inside a central chamber 52 of the body 44 and includes the entry port 36 . The body includes the exit port 38 , first lateral port 40 and second lateral port 42 which, together with the entry port 36 , are confluent to the central chamber 52 such that the body 44 and the core 46 form an air-tight and a fluid-tight connection. The central chamber 52 is only partially filled with the axial portion 48 of the core 46 when the stopcock 34 is fully assembled. The axial portion 48 enters the body 44 through an opening opposite the exit port 38 .
Referring to FIGS. 5A & 5B, the core 46 of the four-port, three-way stopcock is smaller in diameter, and shorter, than the body 44 of the stopcock 34 . The lever 50 is built around the axial portion 48 about a third of the way down from its top end 54 . The axial portion 48 is vertical and has a hollow cavity 55 at its center extending down its entire length. The axial portion 48 has a female luer connector 30 connected to its top end 54 . A groove 56 is carved into the outer surface of the axial portion 48 , beginning at its bottom end 58 and going about one third of the way up its length. An arrow-shaped end 60 of the lever 50 points in the direction that the groove 56 faces. The groove 56 is separated from the hollow cavity 55 by a remaining thickness of material comprising the axial portion 48 .
Referring back to FIG. 4, the axial portion 48 does not extend to the bottom of the central chamber 52 . Thus, there is a small spacing 62 between the bottom of the central chamber 52 and the bottom end 58 of the axial portion, where the groove 56 begins. This spacing and the groove allow fluid to flow between the entry 36 , exit 38 and either the first 40 or second 42 lateral ports, simultaneously, if the lever is pointed toward one of the two lateral ports 40 , 42 . If not, fluid merely flows between the entry 36 and exit 38 ports.
The four-port, three-way stopcock 34 has many drawbacks. First, it lacks the ability to selectively direct IV medications and IV fluids to specific ports and subsequently, to specific parts of the IV system. When the lever 50 is turned toward either of the lateral ports 40 , 42 , fluid flows between the entry 36 , exit 38 and either one of the lateral ports 40 , 42 , simultaneously, instead of selectively between any two ports. Second, because of the design of the stopcock 34 , fluid cannot be directed to flow between the lateral ports 40 and 42 . Third, only one continuous flow path can run through the stopcock 34 at one time. Finally, fluid cannot be selectively, and specifically, diverted from either the entry 36 or exit 38 ports to either lateral port 40 , 42 because the fluid flow path between the entry 36 and exit 38 ports cannot be shut off, i.e., some fluid will always flow between the entry 36 and exit 38 ports.
SUMMARY OF THE INVENTION
The present invention provides a stopcock having two components, a body and a core, that are assembled together and form a fluid-tight and air-tight seal. The body has a number of connectable ports attached to a central chamber. The core has an axial port and is positioned within the central chamber so that it can be rotated with respect to the body. The core also has two separate, non-communicating fluid passages that can carry fluid between two different sets of ports, simultaneously. For example, the core can be rotated to a position wherein one fluid flows between the axial port of the core and one of the connectable ports of the body, while another fluid simultaneously flow between two other connectable ports of the body.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a top view of a prior art three-port, four-way stopcock.
FIG. 1B is a cross-sectional/top view of the T-intersection flow path of a core of a prior art three-port, four-way stopcock.
FIG. 1C is a top view of the lever part of a prior art core of a three-port, four-way stopcock.
FIG. 2 is a top view of a body of a prior art three-port, four-way stopcock.
FIG. 3 is a side view of a core of a prior art four-way, three-port stopcock.
FIG. 4 is a cross-sectional/front view of a prior art four-port, three-way stopcock.
FIG. 5A is side view of a core of a prior art four-port, three-way stopcock.
FIG. 5B is a cross-sectional/top view of a prior art core of a four-port, three-way stopcock.
FIG. 6 is a perspective view of a four-port, four-way stopcock of the present invention.
FIG. 7A is a cross-sectional/top view of a core of a four-port, four-way stopcock of the present invention, taken along the line 7 A— 7 A.
FIG. 7B is a side view of a core of a four-port, four-way stopcock of the present invention.
FIG. 7C is a top view of the lever of a core of a four-port, four-way stopcock of the present invention.
FIG. 8 is a perspective view of a typical IV setup utilizing all four ports and two separate flow paths simultaneously of a four-port, four-way stopcock of the present invention.
FIG. 9 is a perspective view of another embodiment of a four-port, four-way stopcock of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 6, a four-port, four-way stopcock 70 of the present invention comprises a body 72 and a core 74 . In a preferred embodiment, the body 72 is substantially similar to the body 4 of the three-port, four-way stopcock of FIG. 2 . The body 72 includes a main entry port 76 , a main exit port 78 and a secondary entry port 80 , each being confluent to a central chamber 82 . The core 74 has an axial portion 84 , an axial port 96 and a lever 86 . In a preferred embodiment, the main entry port 76 has a female luer lock connector 30 , the main exit port 78 has a male luer lock or luer slip connector 32 and the secondary entry port 80 has a female luer connector 30 attached to its end. In another embodiment (shown in FIG. 9 ), port 80 may have a male luer lock or luer slip type connector.
Referring to FIGS. 7A and 7B, the axial portion 84 of the core 74 includes a first channel 88 , a second channel 90 , a third channel 92 and an axial flow channel 94 , which ends at the opening of the axial port 96 . The first channel 88 and third channel 92 are open to one another, as are the second channel 90 and axial flow channel 94 . Neither the first channel 88 nor third channel 92 is open to either the second channel 90 or axial flow channel 94 , and vice-versa. The second channel 90 opens in the direction in which the lever 86 points. The openings of channels 88 , 90 and 92 are all on the same horizontal plane of the core 74 .
Referring to FIG. 7B, the second channel 90 is shorter than the first channel 88 and third channel 92 and does not intersect them. Instead, a remaining thickness of core material separates the fluid flow path defined by the confluent first channel 88 and third channel 92 .
The axial portion 84 further includes an axial port 96 which opens vertically above the lever 86 . In a preferred embodiment, the axial port 96 includes a female luer-lock connector 30 . The axial flow channel 94 , which opens at the axial port 96 , is not entirely vertical, but is positioned at an acute angle to vertical such that it connects the axial port 96 with the shortened second flow channel 90 , yet avoids connection, or communication, with the fluid flow path formed by the first channel 88 and the third channel 92 .
The four-port, four-way stopcock 70 of the present invention features two independent fluid flow paths through its core 74 . A main fluid flow path is formed by the first channel 88 and third channel 92 , and a secondary fluid flow path is formed by the second channel 90 and the axial flow channel 94 .
When the core 74 is press-fit assembled to the body 72 , the four-port, four-way stopcock of the present invention is complete. The two press-fit parts combine to make an air-tight and a fluid-tight seal.
As the lever 86 is rotated, thereby rotating the core 74 , the second flow channel 90 opens in a new direction equal to the direction into which the protruding lever 86 extends. Flow is enabled between the axial port 96 and either the main entry port 76 , main exit port 78 or secondary entry port 80 via the axial flow channel 94 when the lever 86 is pointing towards one of these respective ports.
There are four positions of the lever 86 which provide four useful ways for fluid to flow through the stopcock 70 . First, when the lever 86 is turned to point in a direction opposite the secondary entry port 80 , medication or fluid, such as a syringe or a secondary IV line, attached to the axial port 96 cannot flow because the second flow channel 90 is blocked, as there is norort extending in that direction to accommodate flow. The main fluid flow path is, however, enabled for flow between the main entry port 76 and main exit port 78 . Second, when the lever 86 is pointed toward the secondary entry port 80 , flow is enabled between the axial port 96 and the secondary entry port 80 , as well as between the main entry port 76 and exit port 78 , simultaneously. Thus, two independent fluid flow paths through the stopcock 70 are enabled and all four ports are being utilized at the same time. Third, when the lever 86 is pointed toward the main entry port 76 , flow is enabled between the axial port 96 and the main entry port 76 , no other ports being enabled. Likewise, and finally, when the lever 86 is pointed toward the main exit port 78 , flow is only enabled between the axial port 96 and the main exit port 78 .
Both aspiration, or flow to the axial port 96 , and infusion, or flow from the axial port 96 are possible in conjunction with any of the three horizontal ports 76 , 78 , 80 . A clinician has the additional option of using the secondary entry port 80 for infusion or aspiration with the axial port 96 , while at the same time enabling flow between the main entry port 76 and main exit port 78 .
Referring to FIG. 7C, the lever 86 has an arrow 98 on its upper surface pointing in a direction in which the lever 86 protrudes. The lever 86 further has the word “ON” 99 written on its upper surface to indicate to the user which way the fluid will flow from or to the axial port 96 into or out of the second flow channel 90 . The lever 86 will always point to the specific port that fluid or medication to/from a syringe or secondary IV line attached to the axial port 96 will flow. A clinician can thus immediately know where fluid to or from the axial port 96 will flow.
The improved stopcock of the present invention has the advantage that it has four-ports and can support fluid flow in four different and useful ways. Also, the flow ports are located in two separate planes, three 76 , 78 , 80 associated with the body 72 in a single horizontal plane and the axial port 96 of the core 74 extending vertically upwards. Prior art devices restrict the possible choices of orientation of the stopcocks and attached medical devices. An additional advantage of the four-port, four-way stopcock 70 of the present invention is that two independent fluid flow paths can be simultaneously enabled. This is not possible with the prior art stopcocks 2 (shown in FIG. 1 A), 34 (shown in FIG. 4 ).
An important clinical situation where the ability to run two separate fluid paths through a stopcock simultaneously would be used, is during blood transfusion. Blood transfusion is a common procedure during surgery and in the post operative care units. Blood is usually obtained from the blood bank in the form of packed red blood cells. The packed red blood cells from the blood bank are cold, and they are a very viscous solution. Packed red blood cells are obtained by separating the fluid plasma from the cells of the whole blood, by centrifuging the blood after the blood has been taken from the donor. The separated blood components are stored in the refrigerator, in the blood bank, to prolong their shelf life. The cold, viscous, packed red blood cells are frequently diluted with saline solution, by the clinician before transfusing them into the patient, to make them less viscous and to warm them up. A warm, and less viscous, solution of red blood cells will flow through an IV system much faster than will a viscous solution of cold packed red blood cells. The ability to transfuse blood rapidly is important when blood must be transfused into a patient as fast as possible to preserve the patient's vital signs.
Referring to FIG. 8, with the four-port, four-way stopcock 70 of the present invention, the main fluid flow path between the main entry port 76 and main exit port 78 can be used as the main IV line to infuse fluids and medications into a patient, while the secondary fluid flow path between the axial port 96 and secondary entry port 80 can be used to dilute the packed red blood cells. To perform this simultaneous procedure, the lever 86 is first turned to point opposite the secondary entry port 80 . This is the “off” position for the axial port 96 because there is no flow port opposite the secondary entry port 80 . In this position, medication is now flowing from a main IV set connected to the main entry port 76 , through the first channel 88 and the third channel 92 , through the main exit port 78 , to the IV extension set connected to the IV catheter in the patient.
A bag of saline solution to be used for diluting the packed red blood cells is next attached to a secondary IV set, and a male luer connector 32 of the secondary IV set is attached to the female luer connector 30 of the secondary entry port 80 . The bag of packed red blood cells is attached to a third IV set, and the male luer connector 32 of this third IV set is attached to the female luer connector 30 at the axial port 96 . After these connections are made, the saline bag is maintained at a level higher than the level of the bag of packed red blood cells.
The lever 86 is next turned to point toward the secondary entry port 80 . This enables the diluting saline solution to flow through the secondary IV set attached to the secondary entry port 80 , through the second channel 90 and axial flow channel 94 , out the axial port 96 , through the third IV set and into the bag of packed red blood cells to dilute the viscous packed red blood cells and make them warmer. Turning the lever 86 toward the secondary entry port 80 also permits continued flow through the main IV flow path, and continued therapy to the patient through the main IV line while the packed red blood cells are being diluted through the secondary fluid flow path. Both the main and secondary fluid flow paths of the stopcock 70 of the present invention are thus flowing simultaneously.
When the red blood cells attached to the axial port 96 have been diluted with the saline solution coming from the secondary entry port 80 , the lever 86 is next turned to point toward the main exit port 78 , and the diluted red blood cells can now flow from the bag of diluted red blood cells, through the third IV set attached to the bag of diluted red blood cells, into the axial port 96 , through the axial flow channel 94 , out of the main exit port 78 and into the patient.
This technique of red blood cell dilution and subsequent infusion into the patient is done with a simple twist of the lever 86 of the four-port, four-way stopcock 70 , and prevents any spillage of valuable blood cells or contamination of any fluids in the IV system. This uninterrupted, red blood cell dilution and transfusion procedure is easily, and sterilely, completed with the four-port, four-way stopcock 70 of the present invention because of the stopcock's ability to enable two separate flow paths at one time.
In another embodiment, the secondary entry port 80 would comprise a male luer slip or luer lock fitting. This is an ideal configuration for filling skin expanders or breast implants (which are typically equipped provided with an inflation tube having a female luer connector) with air or fluid from a syringe attached to axial port 96 .
CONCLUSION
From the foregoing description, it is believed apparent that the present invention provides a novel four-port, four-way stopcock for intravenous injections and infusions. It should be understood, however, that the invention is not intended to be limited to the specifics of the illustrated embodiments, but rather is defined by the accompanying claims. | 4y
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BACKGROUND OF THE INVENTION
This invention relates to ceramic capacitors and in particular, but not exclusively, to multilayer ceramic capacitors and dielectric compositions for use therein.
A multilayer ceramic capacitor basically comprises a stack consisting of a plurality of dielectric members formed of a ceramic material, with electrodes positioned between the members. The electrodes may be screen-printed onto the ceramic material, in the unfired state thereof, using conductive inks. A stack of screen-printed dielectric members is assembled, pressed together, cut into individual components, if appropriate, and fired until sintering occurs, in order to ensure non-porisity. The internal electrodes may be of rectangular form and cover the whole or part of the area of the adjacent dielectric layers. The internal electrodes in successive layers may be sideways stepped relative to one another or have elongate portions which cross one another, as described in British Application No. 7841677 (Ser. No. 2032689A) (A. Oliver-G. Mills 1-1).
With the conventional employed dielectrics the capacitors must be fired at temperatures of the order of 1200°-1400° C., which means that the internal electrodes must be of a suitable material to withstand such temperatures and that, therefore, expensive noble metals, such as platinum or palladium must be used. However, if the firing temperature can be reduced, by a suitable choice of the dielectric, then internal electrodes with a high silver content (50-100% silver) could be used, thus reducing costs for materials and manufacture. In British Application No. 8120605 (Ser. No. 2107300) (J. M. Wheeler 1) there is disclosed a dielectric composition which can be fired at a temperature between 950° C. and 1100° C. and can thus be used with high silver content internal electrodes. These low firing temperature dielectrics comprise lead magnesium niobate PbMg 1/2 Nb 1/2 O 3 with one or more of the following, namely lead titanate, lead stannate, lead zirconate, and some of these dielectric compositions have dielectric constants in the range 7500-10,000, which makes them particularly suitable for multilayer ceramic capacitors. The conventionally employed ceramic (U.S. coding Z5U) which are compatible with high silver content electrodes usually have dielectric constants lower than 6000. The electronics industry, generally, requires smaller components, and smaller and cheaper capacitors can be obtained by producing dielectrics which are compatible with high silver content electrodes and even higher dielectric constants than the 7500- 10,000 range mentioned above with reference to British Application No. 8120605.
In British Application No. 8317265 (Ser. No. 2126575) (J. M. Wheeler 2x) there is disclosed a dielectric composition comprising lead magnesium niobate PbMg 1/2 Nb 1/2 O 3 non-stoichiometric lead iron niobate and one or more oxide additives, which may be chosen from silica, manganese dioxide, ceric oxide, lanthanum oxide, zinc oxide, alumina, tungsten oxide, nickel oxide, cobalt oxide and cuprous oxide. If, for example, three or more oxide additives are chosen from the first eight of the ten mentioned above, compositions having firing temperatures between 980° C. and 1075° C. may be obtained, the dielectric constants after firing being in the range 10,600 to 16,800, making them particularly suitable for small multilayer ceramic capacitors with high silver content electrodes. Additionally the dielectric composition may contain lead titanate (PbTiO 3 ).
SUMMARY OF THE INVENTION
It is an object of the present invention to provide alternative dielectric compositions which can be used with high silver content electrodes and have higher dielectric constants than the Z5U compositions.
According to one aspect of the present invention there is provided a dielectric composition comprising lead magnesium niobate and lead zinc niobate.
According to another aspect of the present invention there is provided a ceramic capacitor including dielectric comprising lead magnesium niobate and lead zinc niobate.
According to a further aspect of the present invention there is provided a multilayer ceramic capacitor including a plurality of layers of dielectric and a plurality of high silver content electrodes arranged between the dielectric layers, which dielectric layers are formed of lead magnesium niobate and lead zinc niobate.
According to yet another aspect of the present invention there is provided a method of manufacturing a multilayer ceramic capacitor including the steps of screen-printing a plurality of electrodes onto each of a plurality of dielectric members, assembling a stack of the resultant screen-printed members, pressing the stack together, dividing the stack into individual capacitor components and firing the individual components at a temperature between 900° to 1075° C., and wherein the dielectric comprises lead magnesium niobate and lead zinc niobate.
The dielectric composition may also include one or more oxide additives chosen from silica, manganese dioxide, zinc oxide, nickel oxide, alumina, ceric oxide, lanthanum oxide, tungsten oxide, gallium oxide, titanium dioxide and lead oxide. One or more of the following may also be added, bismuth stannate, bismuth titanate, lead stannate, lead zirconate and lead titanate with or without oxide additives. The examples of such dielectric compositions quoted hereinafter in Tables 1 to 4 fire at temperatures between 900° C. and 1075° C. and have dielectric constants after firing in the range 9000 to 17,600.
DETAILED DESCRIPTION
The dielectric compositions of the present invention are based on lead magnesium niobate, which may be generally referred to as PbMg 1/2 Nb 1/2 O 3 , and lead zinc niobate, which may be generally referred to as PbZn 1/3Nb 2/3 O 3 , preferably approximately 75% (by weight) of the lead magnesium niobate and approximately 25% (by weight) of the lead zinc niobate, since these proportions appear to provide the highest dielectric constant values. Whereas the lead magnesium niobate is generally referred to as PbMg 1/2 Nb 1/2 O 3 , the material actually employed and for which the results quoted in Tables 1 to 4 were obtained is non-stoichiometric PbMg 0 .443 Nb 0 .5001 O 3 . The expression lead magnesium niobate is however conventionally understood to mean PbMg 1/3 Nb 2/3 O 3 which is not the niobate we have used. The niobate we have used is, generally, non-stiochiometric and approximates to "Mg 1/2 Nb 1/2 ". Preferably the magnesium is in the range 0.35 to 0.5 and the niobium is in the range 0.4 to 0.6. Hence the expression PbMg 0 .35 to 0.5 Nb 0 .4 to 0.6 O 3 .
Lead zinc niobate is conventionally understood to mean PbZn 1/3 Nb 2/3 O 3 whereas non-stoichiometric variations are possible. Preferably the zinc is in the range 0.3 to 0.5 and the niobium is in the range 0.6 to 0.7. Hence the expression PbZn 0 .3 to 0.5 Nb 0 .6 to 0.7 O 3 .
In the following tables measured electrical parameters are quoted, for different firing temperatures, for the base material (Tables 1 and 2) and for the base material with added metallic oxides at the 0.1% (by weight) level (Table 3) or for other levels of added oxides or other additives (Table 4). The various compositions are fired for between one and two hours and aluminium electrodes suitably evaporated onto a surface thereof, so that the dielectric constant, the dielectric loss (tan δ) and the temperature dependence (in %) of the dielectric constant at -30° C. and +85° C. (for Tables l and 3) or +10° C. and +85° C. (for Tables 2 and 4) with respect to the dielectric constant at +25° C. can be measured.
TABLE 1______________________________________FiringTemp. Dielectric Tan. δ Temp. Dependence (%)°C. Constant (%) -30° C. +85° C.______________________________________1025 14500 1.1 +7.6 -55.01050 11100 0.78 +8.0 -50.3______________________________________
TABLE 2______________________________________Firing Dielectric Tan δ Temp. Dependence (%)Temp. Constant (%) 10° C. 85° C.______________________________________ 980 14900 1.1 +14.0 -56.91000 13000 to 14500 1.0 to 1.1 +8 to +15 -55 to -561020 14500 to 15700 0.7 to 1.7 +9 to +16 -56 to -591040 12900 to 13800 1.05 to +10 to +13 -54 to -56 1.45______________________________________
The results obtained for the base material and quoted in Tables 1 and 2 indicate that the base material alone can be used as the dielectric composition for ceramic capacitors since they have values of the required order.
The properties of the base material can however be varied by the use of additives, the results for examples of which are quoted in Tables 3 and 4. In particular the very high dielectric constant values and very low firing temperatures obtained when PbO is added should be noted in Table 4, as well as the combination of high dielectric constant with temperature coefficient of capacitance well within the Z5U range when three additives PbZrO 3 , TiO 2 and Bi 2 Ti 2 O 7 are incorporated into the dielectric.
It is anticipated that similar combinations of three or more additives chosen from those listed in Tables 3 and 4 will also give dielectrics having properties suitable for use in multilayer ceramic capacitors.
The composition including 5% lead oxide, which fires at temperatures less than 950° C. (900° C. quoted in Table 4), has a high dielectric constant value and temperature coefficient of capacitance within the Z5U range, is of particular interest since it enables firing with 100% silver electrodes.
TABLE 3______________________________________Addition toTemp.Dependence (%)base material Firing Dielectric Tan+85° C. Temp. δ0.1% °C. Constant (%) -30° C.______________________________________SiO.sub.2 1000 11400 1.3 +8.5 -53 1025 15150 1.0 +12 -57 1050 12450 0.87 +10 -52MnO.sub.2 1000 10200 0.86 +8 -55 1025 12900 0.54 +12.5 -54 1050 11150 0.74 +11 -50.5ZnO 1000 10100 1.22 +7 -50 1025 13950 1.00 +11 -55 1050 11800 0.95 +9.5 -52.5NiO 1000 9550 1.17 +7 -48 1025 13800 0.82 +14 -57 1050 12050 0.74 +9 -50Al.sub.2 O.sub.3 1000 10850 1.18 +8 -50 1025 14500 0.73 +14 -57 1050 11750 0.75 +9 -50CeO 1000 10700 0.87 +8 -50 1025 12600 0.66 +14 -53 1050 9700 0.76 +9 -47La.sub.2 O.sub.3 1000 9700 0.88 +11 -47 1025 13750 0.44 +19 -56 1050 10400 0.75 +13 -51.5WO.sub.3 1000 10300 1.25 +9 -49 1025 15050 0.73 +15 -56.5 1050 10850 0.63 +6 -54.5SiO.sub.2 MnO.sub.2 1000 11500 0.94 +6 -45 1025 12900 0.91 +9 -51.5 1050 10600 0.59 +8.5 -49SiO.sub.2 ZnO 1000 11550 0.95 +8 -51 1025 14700 0.80 +11 -56 1050 13000 0.98 +10 -55SiO.sub.2 NiO 1000 11950 1.34 +5 -47 1025 14250 0.92 +13 -56 1050 12100 0.96 +8 -52SiO.sub.2 Al.sub.2 O.sub.3 1000 9000 1.01 +10 -51 1025 12400 0.79 +14 -55 1050 11900 1.04 +9 -53SiO.sub.2 CeO 1025 11000 0.55 +10 -53 1050 11450 0.80 +11 -52 1075 12250 1.03 +7 -55SiO.sub.2 La.sub.2 O.sub.3 1025 11000 0.56 +14 - 54 1050 12200 0.69 +13 -53 1075 13000 1.19 +11 -57.5SiO.sub.2 WO.sub.3 1000 9550 1.17 +7 -51 1025 11700 0.64 +7 -55 1050 11500 1.02 +7 -53______________________________________
TABLE 4__________________________________________________________________________Addition to Firing Dielectric Tan δ Temp. Dependence (%)base material Temp. C. Constant (%) +10° C. +85° C.__________________________________________________________________________ 3 wt. % Ga.sub.2 O.sub.3 980 11600 0.65 +19 -55 1020 15000 1.15 +15.2 -55.9 4 wt. % Ga.sub.2 O.sub.3 980 13100 0.90 +18 -55 5 wt. % Ga.sub.2 O.sub.3 980 10200 0.70 +17 -51 1020 12200 0.70 +15.1 -55.1 0.075 wt. % TiO.sub.2 1020 15400 1.2 +11.5 -54.8 0.25 wt. % PbO 950 15300 1.05 +12.6 -57.1 980 15100 1.1 +11.0 -55.8 1020 15600 1.05 +12.5 -56.5 1 wt % PbO 950 15200 1.00 +12.6 -56.6 980 15600 1.05 +11.4 -56.5 1020 16300 1.05 +12.1 -56.3 5 wt. % PbO 900 13400 1.05 +13.1 -53.5 980 16100 1.0 +11.5 -56.4 1020 16000 0.8 +10.1 -58.3 10 wt. % PbO 900 11000 1.2 +13.0 -52.2 980 16250 1.15 +13.3 -56.1 1020 16300 1.0 +13.3 -56.9 0.5 wt % Bi.sub.2 (SnO.sub.3).sub.2 1000 13200 0.70 +23.7 -54.0 1020 14100 0.60 +21.0 -54.7 1 wt. % Bi.sub.2 (SnO.sub.3).sub.2 1000 11600 0.45 +22.7 -50.1 1020 11800 0.30 +21.0 -54.0 1 wt. % Bi.sub.2 (SnO.sub.3).sub.2 1000 14100 0.95 +17.3 -50.9 2 wt. % PbTiO.sub.3 1020 14000 0.95 +14.0 -53.0 2 wt. % Bi.sub.2 (SnO.sub.3).sub.2 1020 12100 2.90 +1.0 -46.5 6 wt. % PbTiO.sub.3 1 wt. % Bi.sub.2 Ti.sub.2 O.sub.7 1020 10500 0.55 +16.2 -49.2 0.5 wt. % PbSnO.sub.3 1020 14100 0.65 +16.5 -54.2 0.5 wt. % PbSnO.sub.3 1020 14300 2.55 +4.9 -49.9 5 wt % PbZrO.sub.3 2 wt. % PbTiO.sub.3 1040 15000 1.55 +3.1 -54.2 0.5 wt. % WO.sub.3 1 wt. % PbTiO.sub.3 1040 15000 1.75 +5.2 -55.7 0.05 wt. % La.sub.2 O.sub.3 4 wt. % PbZrO.sub.3 1020 14600 3.3 +2.9 -53.5 0.075 wt. % TiO 1040 1430 2.7 0.0 -50.9 (4 wt. % PbZrO.sub.3) 980 17600 2.9 +8.9 51.7 0.07 wt % TiO.sub.2 1000 15200 2.6 +8.8 52.0 0.8 wt % Bi.sub.2 Ti.sub.2 O.sub.7 1020 15800 2.7 +8.3 -52.2__________________________________________________________________________
Table 4 indicates the results obtained for oxides other than those quoted in Table 3, and for which the temperature dependence has been measured at different temperatures to those in Table 3. Results are also quoted for additives whose major proportions are other than simple oxides, e.g. bismuth stannate, bismuth titanate, lead stannate, lead zirconate and lead titanate.
In addition to the parameters quoted in Table 3, the temperature coefficient of capacitance, for the constituent examples quoted therein, shows Z5U characteristics, that is between 10° C. and 85° C. the capacitance varies less than +22%, -56% (EIA Code). Thus the invention provides dielectric compositions which fire at low temperatures 900° to 1075° C.), and are thus compatible with high silver content internal electrodes, have relatively high dielectric compositions (9000-17,600) and have Z5U temperature dependence characteristics. It is anticipated that additives comprising three or more of the oxides, added at the 0.1% level to the base material, will provide similar characteristics to those quoted for one or two.
A method of manufacturing a multilayer ceramic capacitor using the dielectric compositions of Tables 1 to 4 may comprise the step of screen printing a plurality of electrodes on each of a plurality of unfired dielectric sheets with a high silver content ink; assembling a stack of such printed sheets with the electrodes of alternate layers arranged relative to one another as appropriate to the particular construction employed, for example sideways stepped or overlapping cross-wise; pressing the sheets together with extra blank ceramic sheets applied to the top and bottom of the stack if required; cutting the sheets to form individual capacitor components and firing the individual components at a temperature between 900° and 1075° C. Subsequently the electrodes between every other sheet may be connected in a conventional manner (end terminated) by the appropriate application of conductive paint, for example, to opposite end (side) faces of the stack.
Whilst specific reference has been made to the use of high silver content electrodes, the dielectric compositions of the present invention may be used with other electrode materials, such as palladium, platinum or gold.
Whilst specific mention has been made of multilayer capacitors with internal electrodes, the dielectric compositions of the present invention can alternatively by used with other ceramic capacitor types, with or without electrodes that are fired with the ceramic. | 4y
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FIELD OF THE INVENTION
[0001] This invention relates generally to fluid heating systems, and the use thereof, and, more particularly, to vehicle fluid heating systems.
BACKGROUND OF THE INVENTION
[0002] In cold climates, it is important to minimize the amount of time needed to warm a vehicle to operating temperature. More specifically, the temperature of the hydraulic oil must be increased to a minimum operating temperature before implement operation, such as a loader, is allowed. This oil can be heated by the operator manually by cycling the loader circuit, but this activity can be both fatiguing and time-consuming to the operator. Alternatively, the vehicle could include a system or arrangement on the vehicle to warm the hydraulic oil already being automatically circulated, such as with a fixed-flow cooling fan circuit.
[0003] A drawback of a fixed-flow cooling fan circuit is that it is pressure-controlled. That is, a fixed amount of flow supplies the circuit via a gear pump, and a variable pressure-relief valve defines the inlet pressure to the hydraulic cooling fan. In response to an increase in the pressure in the cooling fan circuit, the speed of the cooling fan likewise increases, providing undesirable cooling to the same hydraulic oil that is to be heated. In other words, it has not been possible to generate a high system pressure (which would most quickly heat the oil) without also operating the cooling fan at a high speed.
[0004] Accordingly, it would be desirable to provide an inexpensive pressure-controlled fixed-flow cooling fan circuit to operate at a high pressure without increasing the speed of the cooling fan in order to minimize time associated with heating hydraulic oil associated with implement operation of a work vehicle. It would additionally be desirable for the fan circuit to operate essentially independently of an operator (an automatic process) that generates large amounts of pump flow at a high pressure, and operates independently of or without resulting in external movement of the implement.
SUMMARY OF THE INVENTION
[0005] The present invention relates to a fluid heating system for a work vehicle including a pressurized fluid circuit having a pump and a fan for cooling pressurized fluid of the fluid circuit. Pressurized fluid of the fluid circuit provided to the fan results in fan operation. A speed of the fan corresponding to a flow rate of pressurized fluid of the fluid circuit provided to the fan. A control device is in fluid communication with the fluid circuit, the control device operable between a first position and a second position. The first position of the control device results in substantially all of the pressurized fluid of the fluid circuit being provided to the fan. The second position of the control device results in at least a portion of the pressurized fluid of the fluid circuit bypassing the fan, thereby reducing the speed of the fan while increasing a pressure magnitude of and increasing a temperature of the fluid system.
[0006] The present invention further relates to fluid heating system for a work vehicle including a pressurized fluid circuit having a pump and a fan for cooling pressurized fluid of the fluid circuit. Pressurized fluid of the fluid circuit provided to the fan results in fan operation, the fluid circuit operating independent of or not resulting in external movement of an implement. A speed of the fan corresponds to a flow rate of pressurized fluid of the fluid circuit provided to the fan. A control device is in fluid communication with the fluid circuit, the control device operable between a first position and a second position. The first position of the control device results in substantially all of the pressurized fluid of the fluid circuit being provided to the fan. The second position of the control device results in at least a portion of the pressurized fluid of the fluid circuit bypassing the fan, thereby reducing the speed of the fan while increasing a pressure magnitude of and increasing a temperature of the fluid system.
[0007] The present invention further relates to a method for heating a work vehicle including providing a pressurized fluid circuit having a pump and a fan for cooling pressurized fluid of the fluid circuit. Pressurized fluid of the fluid circuit provided to the fan results in fan operation. A speed of the fan corresponds to a flow rate of pressurized fluid of the fluid circuit provided to the fan. A control device is in fluid communication with the fluid circuit, the control device operable between a first position and a second position. The first position of the control device results in substantially all of the pressurized fluid of the fluid circuit being provided to the fan. The second position of the control device results in at least a portion of the pressurized fluid of the fluid circuit bypassing the fan, thereby reducing the speed of the fan while increasing a pressure magnitude of and increasing a temperature of the fluid system. The method further includes selectably actuating the control device between the first position and the second position.
[0008] An advantage of the present invention is the capability to rapidly warm hydraulic oil in a hydraulic circuit.
[0009] A further advantage of the present invention is the capability to rapidly warm hydraulic oil in a hydraulic circuit independent of or without resulting in external movement of an implement or requiring continuous input from an operator.
[0010] It is to be understood that an embodiment of the present invention may incorporate one or more of the identified advantages.
[0011] Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIGS. 1 and 2 are schematic representations of an exemplary embodiment of a fluid heating system of the present disclosure.
[0013] Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
DETAILED DESCRIPTION OF THE INVENTION
[0014] Referring to the drawings, FIGS. 1-2 show schematic representations of an exemplary embodiment of the present disclosure. FIG. 1 shows a fluid heating system 10 including a control device 12 , such as a digitally controlled solenoid valve having a first position 20 and a second position 22 . Control device 12 is controlled by a control module 24 that receives input signals from sensors 34 associated with temperatures and/or other component/system/subsystem operating parameters. Under normal operating conditions, such as when the ambient temperature is greater than a predetermined minimum temperature, such as 90° C. in one application, and in combination with other parameters in other applications such as discussed in further detail below, hydraulic pump 26 provides pressurized hydraulic oil to a fluid circuit 28 . In response to sensors 34 controlled by control module 24 sensing the temperature of the hydraulic oil in fluid circuit 28 , as well as other temperature/parameters as discussed in further detail below, control device 12 is maintained in first position 20 , providing unobstructed flow to and from fan motor 14 .
[0015] However under operating conditions in which hydraulic oil is less than a predetermined minimal temperature, such as zero (0)° C. in one operating condition, and in combination with other parameters and other operating conditions such as disclosed in further detail below, a motor hydraulic pump 26 provides pressurized hydraulic oil to fluid circuit 28 . In response to sensors 34 controlled by electronic control module 24 , the temperature of the hydraulic oil and fluid circuit 28 , as well as other exemplary temperature/parameters that are below predetermined minimum values as discussed in further detail below, control device 12 is actuated to second position 22 . As shown in the figures, second position 22 of control device 12 contains a flow restrictor therein for raising the fluid pressure between pump 26 and control device 12 . When the fluid pressure of the hydraulic oil is sufficiently raised, a valve such as a pressure relief or bypass valve 30 is urged to an open position, permitting the pressurized oil to bypass fan motor 14 such as shown by directional arrows 36 , continue through the remainder of fluid circuit 28 through to oil sump 32 . As a result, the pressurized oil bypassing fan motor 14 , only a small amount of hydraulic oil reaches fan motor 14 , so that fan motor 14 operates at a reduced rotational speed, thereby reducing cooling capacity of hydraulic oil contained in fluid circuit 28 by fan 16 , while forcing flow of hydraulic oil of fluid circuit 28 to bypass the majority of the system flow at an elevated pressure back to oil sump 32 . The combination of flow of the hydraulic oil at increased pressure, as well as the reduced cooling capacity of fan 16 more quickly results in raising the fluid temperature of the hydraulic oil. In other words, the arrangement of the control device 12 reduces the amount of time required to reach a nominal hydraulic oil operating temperature, while requiring no continuous interaction from the operator, such as initial operator interaction of an optional manually operated control 42 . In one embodiment, fluid heating system 10 operates substantially independent of or substantially without input from an operator. In another embodiment, operation of fluid heating system 10 may be automatic, i.e., not requiring interaction from the operator.
[0016] As shown in the figures, fluid circuit 28 includes one of component module 38 or component module 40 , depending upon which of component modules 38 , 40 is purchased by the user. The component modules 38 , 40 which are not otherwise relevant to operation of the present disclosure are not further discussed.
[0017] An optional heat exchanger 44 may be utilized by fluid circuit 28 , such as for purposes of thermal exchange with other system(s) and/or subsystem(s) such as discussed in more detail below. The location of exchanger 44 may be utilized anywhere downstream of the node 46 of component module 40 , or downstream of the node 48 of component module 38 , depending on which of component modules 38 , 40 is present in fluid system 28 .
[0018] It is to be understood that the size of the restriction of control device 12 and second position 22 may be optimized to generate a specific heat load. In one embodiment, control device 12 may have multiple positions with differently sized restrictions. In one embodiment, the restriction of control device 12 may be variably sized.
[0019] It was found in development that this solution could also solve an additional problem discovered on working vehicles, such as diesel burning wheel loaders with Selective Catalytic Reduction (SCR) exhaust treatment. On some of these vehicles, the engine must be periodically warmed above a certain temperature when idling for extended periods of time, such as more than six hours, to prevent damage to the vehicle. The system 10 described above can be used to increase the temperature of the diesel engine (and in turn the SCR system) by creating a parasitic load on the engine in the manner previously described. By energizing or actuating control device 12 to second position 22 , it was shown that the temperature of the diesel engine could be elevated above this threshold temperature automatically, again independent of or without any input from the operator. This arrangement has an additional advantage of substantially eliminating external motion such as might be associated might when loading the engine via the ground drive or implement hydraulic cylinders. Substantially eliminating such external motion of the work vehicle reduces danger and risk to objects and personnel near the work vehicle while permitting a process that can be automatically performed. It is to be understood that the system 10 would be operated at predetermined time intervals less than those resulting in damage to the vehicle.
[0020] Control device 12 operation can also be utilized to warm a frozen urea tank (not shown) more quickly, reducing the time to operation of the work vehicle in cold temperatures, the urea used as a reductant within the SCR system.
[0021] There are at least four different uses of the fluid heating system of the present disclosure:
1. Heating the air temperature inside the cab more quickly 2. Periodically elevating the engine temperature to combat hydrocarbon build-up in SCR system 3. More rapidly warming the urea tank 4. More rapidly warming the hydraulic oil.
[0026] In one embodiment, feedback signals received from various sensors provided to the control module may include the following operating parameters:
Ambient Temperature
Coolant Temperature
Transmission Oil Temperature
Hydraulic Oil Temperature
Urea Temperature
Engine Speed
[0027] Fan Reverser state
Auto Fan state
However, in other embodiments, other combinations of feedback signals, possibly including additional parameters may be utilized, such as air cabin temperature.
[0028] One embodiment relates to heating the air temperature inside the operator cab more quickly. For example, to turn ON the feature (i.e., energize the control valve or control device 12 ) all of the following conditions must be met for a predetermined period of time, such as 20 consecutive seconds, although in other embodiments other time periods of different duration and/or different parameters may be used:
Ambient Temperature<0° C.
Coolant Temperature<75° C.
Transmission Oil Temperature<75° C.
Hydraulic Oil Temperature<75° C.
Engine Speed>650 RPM
[0029] Fan Reverser state=Not Active
Auto Fan=ON
[0030] In this embodiment, once the valve or control device 12 is energized (ON), auto fan control is be disabled and fan speed should be set to maximum fan speed.
[0031] In this embodiment, once the valve or control device 12 is energized, any of the following conditions may be used to turn the valve OFF, although in other embodiments, the number and amount of conditions may be different:
Charge Air Temperature>90° C.
Coolant Temperature>85° C.
Transmission Oil Temperature>90° C.
Hydraulic Oil Temperature>90° C.
Engine Speed<600 RPM
Fan Reverser=Active
[0032] In this embodiment, if any parameter for entry or exit condition of this routine is not present or out of range, then the feature is disabled.
[0033] In one embodiment, to periodically elevate the engine temperature to combat hydrocarbon build-up in the SCR system:
[0034] To turn ON the feature (i.e., energized the valve or control device 12 ) the following conditions are to be met for X1 consecutive seconds:
Coolant Temperature<Y1° C.
Once the valve or control device 12 is energized, auto fan control is to be disabled and fan speed is to be set to maximum fan speed.
Once the valve or control device 12 is energized, the following conditions may be used to turn the valve OFF:
Temperature>YY1° C. for Z1 consecutive seconds (YY1≧Y1)
If the Coolant Temperature signal is not present or out of range, then the feature is to be disabled.
[0037] In one embodiment, to more rapidly warm the urea tank:
[0000] To turn ON the feature (i.e., energize the valve or control device 12 ) the following conditions are to be met for X2 consecutive seconds:
Urea Temperature<Y2° C.
Once the valve or control device 12 is energized, auto fan control is to be disabled and fan speed set to maximum fan speed.
Once the valve or control device 12 is energized, the following conditions may be used to turn the valve OFF:
Urea Temperature>YY2° C. for Z2 consecutive seconds (YY2≧Y2)
If the: Urea Temperature signal is not present or out of range, then the feature is to be disabled.
[0040] In one embodiment, to more rapidly warm the hydraulic oil:
[0000] To turn ON the feature (i.e., energize the valve or control device 12 ) the following conditions are to be met for X3 consecutive seconds:
Hydraulic Oil Temperature<Y3° C.
Once the valve or control device 12 is energized, auto fan control is to be disabled and fan speed set to maximum fan speed.
Once the valve or control device 12 is energized, the following conditions are to turn the valve OFF:
Hydraulic Oil Temperature>YY3° C. for Z3 consecutive seconds (YY3≧Y3)
If the: temperature signal is not present or out of range, then the feature is to be disabled.
[0043] While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. | 4y
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TECHNICAL FIELD
The present invention relates generally to tools employed in the telecommunication industry for seating and cutting the free ends of wires inserted into resilient telephone wire terminal receptacles such as the AT&T/Lucent Technologies RJ-45/M-series type jacks. It is more particularly directed to a new and improved wire-insertion and cutting tool head, geometrically configured to match a resilient telephone wire terminal receptacle such that when pressure is applied to the head from a source such as a handle, the head will provide means by which to seat and cut multiple wires that have been inserted into the wire terminal receptacle. Thus, with one impact, a multiplicity of wires may be simultaneously seated into a wire terminal receptacle and cut.
BACKGROUND OF THE INVENTION
Tools for terminating electrical conductors at terminal clips or blocks are widely used in the telephone industry. Currently, there is a wide variety of such instruments, generally serving the purpose of cutting and seating individual telephone wires. Examples of a few such tools may be found in U.S. Pat. Nos. 5,832,603; 5,758,403; 5,628,105; 4,656,725; and 4,161,061 and the patents cited therein.
Typical impact tools include an elongated handle and an impact head for cutting and seating wires in a terminal block. Such a handle may contain a hammer element and a compression spring arranged such that the spring actuates the hammer, causing it to strike the impact head. Thus, the hammer provides an impact force that causes the impact head to cut and seat the wires into the terminal block. In operation, the impact head is aligned with, and pushed into, a terminal block. As the handle is pressed, the spring is released, forcing the hammer against the impact head. The force stored in the spring is thus translated into the impact head, thereby forcibly cutting and seating one or more wires in the terminal block. In place of handles, some impact tools utilize electric motors to provide the impact force; thereby reducing the manual strength required to seat and cut the wires in a terminal block.
With the increasing complexity of terminal blocks and the need for technicians and craftspersons to efficiently use their time, a need arose to develop means by which multiple wires can be cut and seated simultaneously. Early solutions to this problem, although providing great improvements over prior single-wire seating and cutting techniques, have met with limited success.
Examples of these solutions include wire-insertion and cutting heads such as those employed by AT&T model 788J1 and Seimens model S788J impact tools. Illustrations of these tools, which comprise separate wire-insertion and seating blade support blocks and knife blade support blocks are provided in FIGS. 1 and 2, respectively. The wire-insertion and seating blade block includes a plurality of slotted copper wire-insertion blades 1 captured within respective slots 3 formed in a region of the base block 5 and extending into respective standoffs 7 in the wall of the base block 5 . A base region 9 with ribs 11 is formed on one side of the wire-insertion and seating blade block in order to accept the knife blade support block. The knife blade support block 21 is made of an injection molded insulating material and contains a plurality of razor blade-like cutting knives 23 securely retained therein. Depressions 25 are molded into the base of the knife blade support block 21 in order that the ribs 11 of the wire-insertion and seating blade block may be received such that the wire-insertion and seating blade block and knife blade support block 21 may be maintained in an operative relationship during use. FIGS. 3 and 4 demonstrate this impact head in an operative relationship with a terminal receptacle 31 during normal operation. As depicted, the dimensions of the impact head are chosen such that the contacts 33 in the terminal receptacle 31 are bridged by the slotted copper wire-insertion blades 35 of the wire-insertion and seating blade block 37 . When the impact head is actuated, the wire 39 is pressed against the bottom surface 41 of the slot in the terminal receptacle 31 and the end of the wire 43 is severed by the cutting knives 23 of the knife blade support block 21 . During this process, the contacts cut into the wire jacket 45 , electrically contacting the wire 39 . Unfortunately, the experience of technicians and craftspersons has revealed a major shortcoming of this design, as depicted in FIG. 5 . In this case, the impact head has been actuated but did not cut the wire. This problem is the result of the two-piece design of the impact head and the associated play between the parts. Even when the two pieces are properly aligned, a small amount of play is allowed therebetween. Furthermore, small particulate pieces of matter such as plastic from the terminal block or pieces of wire insulation may become lodged between the impact head pieces, causing malfunction. Additionally, this problem may be caused or exacerbated by failure to properly align the impact tool with the terminal receptacle. Any wires remaining uncut must be individually severed with the use of a separate tool.
An attempt to correct these shortcomings is disclosed in U.S. Pat. No. 5,836,069 and U.S. Pat. No. 5,628,105, the first being to an impact tool head having a plurality of unitary pressing and cutting blades and the second being to a wire termination tool in which the impact tool head is incorporated. In order to solve the problem of misalignment between parts, this impact head included an injection-molded piece with a plurality of integrally formed wire-seating and cutting blades. Thus, the misalignment problems associated with the two-piece impact head design were overcome.
In order to construct the one-piece impact head, as detailed in U.S. Pat. No. 5,836,069, a plurality of integrally formed wire-seating and cutting blades 60 such as the one shown in FIG. 6 are positioned in a molded support block 70 as shown in FIG. 7, such that they are aligned in a generally parallel fashion. The final assembly for an impact head of this type is shown in FIG. 8 . The use of this impact head in alignment with a terminal receptacle of a termination block is demonstrated in FIG. 9 . This design's main advantage is that the cutting blade is forced to remain in alignment with the rest of the tool, thus eliminating the problem of uncut wires due to play between the parts. Although this design increases the wire-cutting reliability of the impact head, it suffers from several important drawbacks. First of all, the integrally formed wire-seating and cutting blades, because of their integral nature, must be fabricated from a material that is functional for both cutting and seating wires. As such, the material must be soft enough to minimize damage to the terminal receptacle, yet be hard enough to provide a durable cutting instrument. Because damage minimization and durability as a cutting surface are somewhat conflicting requirements, a manufacturer must make a compromise between the two functions when choosing materials. Second, the design of the integrally formed one-piece impact head is such that post-fabrication sharpening of the blades is not practical. Consequently, differences in blade length due to positioning variations of the integrally formed wire-seating and cutting blades in the mold results in a more rapid dulling of some blades than of others. As some blades dull and others remain sharp, it is likely that not all of the wires will be cut with one impact, and therefore, multiple impacts will be required to cut and seat the wires in a terminal. Multiple impacts not only require additional time and labor but may also cause structural damage to the terminal head. Furthermore, dull blades require a more powerful impact for successful cutting, which may cause structural damage as well. Third, because this design requires the placement of a plurality of integrally formed wire-seating and cutting blades in the mold prior to fabrication, consistent alignment is difficult and manufacture is costly.
The invention disclosed herein overcomes these difficulties by providing a one-piece integrally molded impact head having distinct pressing and cutting blades which can be chosen from different materials to optimize the seating and cutting functions independently. Additionally, the dimensions of the pressing and cutting blades may be independently chosen to optimize their effectiveness in their distinct roles. Furthermore, the integral molded structure is designed such that the blades may be sharpened after the molding process is complete, thus ensuring blade uniformity for improved durability. Finally, the design of the impact tool head disclosed herein, because of its multi-component nature, is readily adaptable to different terminal block configurations, and may optionally be made to press wires into the grooves of only one terminal ridge and to cut the wires on only one side of the terminal ridge. Thus, the impact tool head disclosed herein provides an improved device for cutting and seating wires in the same terminal blocks as the prior-art tools just described, such as a Lucent 110-type terminal block. Further, the present invention may economically constructed such that it may cut and seat wires across a plurality of terminal ridges in a Lucent 110-type terminal block, thus providing for further improvement over the prior-art tools.
SUMMARY OF THE PRESENT INVENTION
In accordance with the present invention, an improved impact tool head having separate and distinct pressing and cutting blades integrally molded therein is presented. This impact tool head allows different materials to be chosen for the pressing blades and for the cutting blades. Thus, it provides the ability to optimize both the pressing and the cutting processes independently without the compromises necessitated by having separate blocks for the pressing and cutting blades or by the use of a single uniform material piece for both the pressing and cutting blades. Additionally, sets of pressing blades and sets of cutting blades may be formed, each set comprising one continuous piece of material in order to reduce manufacturing costs and to ensure uniformity of production. Also, by allowing the pressing blades and cutting blades to be formed separately, adjustments in the dimensions of each may be made independently of the other. Thus, it is possible to ensure optimal design of each and to adapt the design to the needs of a variety of terminal block configurations. Furthermore, the integral molded structure is designed to allow post-molding sharpening of the cutting blades in order to ensure blade uniformity for improved durability.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of wire-insertion and seating blade block of a conventional two-piece wire-insertion and cutting impact head assembly;
FIG. 2 is a perspective view of a knife blade support block of a conventional two-piece wire-insertion and cutting impact head assembly;
FIG. 3 is a diagrammatic representation of an operationally combined wire-insertion and seating blade block and knife blade support block of a conventional two-piece wire insertion and cutting impact head assembly of FIGS. 1 and 2, operatively aligned with a terminal receptacle of a terminal block;
FIG. 4 is a diagrammatic representation of an operationally combined wire-insertion and seating blade block and knife blade support block of a conventional two-piece wire insertion and cutting impact head assembly of FIGS. 1 and 2, operatively aligned with, and actuated against, a terminal receptacle of a terminal block demonstrating the wire insertion and seating blades and knife blades in operative contact with a wire;
FIG. 5 is a diagrammatic representation of an operationally combined wire-insertion and seating blade block and knife blade support block of a conventional two-piece wire insertion and cutting impact head assembly of FIGS. 1 and 2, demonstrating the unwanted deflection of a knife around a wire jacket;
FIG. 6 is a perspective view of the prior art unitary wire seating and cutting blade used in a unitary element impact tool head;
FIG. 7 is a front view of an embodiment of the prior art unitary element impact tool head demonstrating the operative positioning of the unitary wire-seating and cutting blades shown in FIG. 6;
FIG. 8 is a perspective view of an embodiment of the prior art unitary element impact tool head utilizing a plurality the of the unitary wire-seating and cutting blades shown in FIG. 6;
FIG. 9 is a diagrammatic representation of the prior art unitary element impact tool head demonstrating its use operatively aligned with, and actuated against a terminal receptacle of a terminal block such that it is operative to seat and cut a wire;
FIG. 10 is a perspective view of a preferred embodiment of an assembled impact tool head according to the present invention;
FIG. 11 is a front view of an embodiment of a set of four of separate and distinct pressing blades according to the present invention;
FIG. 12 a is a front view of an embodiment of a pair of separate and distinct pressing blades according to the present invention;
FIG. 12 b is a side view of an embodiment of a pair of separate and distinct wire-pressing blades according to the present invention;
FIG. 13 is a perspective view of a pre-assembly embodiment of a wire-cutting blade set according to the present invention;
FIG. 14 is a cutaway side view demonstrating the operative alignment of the separate and distinct wire-pressing blades and wire-cutting blades within the impact tool head according to an embodiment of the present invention;
FIG. 15 is a cutaway front view demonstrating the operative alignment of the separate and distinct wire-pressing blades and wire-cutting blades within the impact tool head according to an embodiment of the present invention;
FIG. 16 is a perspective view of an example of a terminal block with which the impact tool head of the present invention would be used;
FIG. 17 is a diagrammatic representation of the impact tool head demonstrating its use operatively aligned with, and actuated against a terminal receptacle of a terminal block such that it is operative to seat and cut a wire;
FIG. 18 is a perspective view of a second preferred embodiment of the impact tool head in a configuration including one set of cutting blades and individual pressing blades;
FIG. 19 is a cutaway side view of a second preferred embodiment of the impact tool head as shown in FIG. 18 operatively aligned with, and actuated against a terminal block.
DETAILED DESCRIPTION
A perspective view of a preferred embodiment of an assembled impact tool head according to the present invention is shown in FIG. 10 . The impact tool head is of generally rectangular shape, including a support block body 101 formed of an injection-moldable and suitably resilient insulating material, preferably a plastic material such as liquid crystal, ryton, ultem, or mineral filled nylon. The support body block 101 includes a longitudinal groove 103 formed in the body material and extending along the length of the support body block 101 between end faces 105 and 107 . The longitudinal groove 103 opens on a generally planar surface 109 and is sized to accommodate a multiple terminal wire cable within the terminal block. Pairs of pressing blades 111 reside perpendicular to, and on either side of the longitudinal groove 103 . The tops of the pressing blades 111 are substantially planar with the generally planar surface 109 . Cutting blade portions 115 extend perpendicularly beyond the generally planar surface 109 and abut the pressing blades 111 opposite the longitudinal groove 103 . In this particular embodiment, shoulders 117 are formed adjacent the cutting blade portions 115 and opposite the pressing blades 111 on the generally planar surface 109 to allow the impact tool head to be grasped within an impact tool. The dimensions of the individual pieces of the impact tool head may be chosen to allow usage with differently sized and configured terminal blocks.
Two versions of a pre-assembly embodiment of wire-pressing blades according to another version of the invention are shown in FIGS. 11 and 12, respectively. The version of FIG. 11 demonstrates the manufacture of four wire-pressing blades in one unit and the version of FIG. 12 a and FIG. 12 b , respectively, demonstrate front and side views of the manufacture of two wire-pressing blades as a single unit. The pressing blades 111 are formed of a resilient material sufficiently durable to endure many impacts, e.g. beryllium copper, a carbon composite, or other sufficiently hard material. The material of the pressing blades 111 is preferably chosen to avoid chemical interaction with the cutting blades 115 . The pressing blades 111 each include a first pressing surface 119 and a pressing surface 121 separated by a straddle portion 123 which forms a substantially U shape therebetween. The dimensions of the straddle portion 123 are chosen such that the first pressing surface 119 and the second pressing surface 121 press a wire into a terminal slot without contacting or damaging the terminal contacts during operation (FIGS. 16 and 17 with their accompanying explanations will provide further information in this regard). In the embodiments of FIGS. 11 and 12, sets of pressing blades are formed as a single piece, connected by a center portion 125 having a breakable portion 127 . Notches 129 and 131 may be formed in the center portion 125 on either side of the breakable portion 127 to permit easy removal after molding so that electrical conduction is impossible between adjacent pressing blades. This is necessary to prevent electrical shorting between adjacent conductors in a terminal block during operation of the impact tool head. The pressing blades 111 further include seating portions 133 , which preferably include locking holes 135 through which injection-moldable material flows and hardens during molding to fixedly hold the pressing blades 111 in place within the impact tool head. FIG. 12 b provides a side view of a pair of wire-pressing blades according to the invention in order to more specifically show the relationship between the pressing blades 111 , the center portion 125 , the breakable portion 127 , and the notches 129 and 131 . Additionally, the thickness 137 of the pressing blades 111 is chosen to allow for optimal fit when pressing wires into a slot in particular terminal block.
A pre-assembly embodiment of a wire-cutting blade set 150 according to the invention is shown in a perspective view in FIG. 13 . The set of wire-cutting blades 150 is formed of a hardened material such as 440C steel, and includes a breakaway portion 152 from which extend one or more cutting blades 154 each including a cutting blade portion 115 with a bevel-shaped cutting end 156 formed thereon. An arched locking portion 158 is formed between the breakaway portion 152 and the bevel-shaped cutting ends 156 along the cutting blade portions 15 in order to help hold the wire-cutting blade set 150 rigidly in place within the impact head after the molding process. The arched locking portion 158 preferably takes the shape of a roughly 90-degree arc, as shown in the figure. Also, the cutting blades 154 are preferably formed as individual blades as shown in FIG. 13, but could be formed as a single, wider, blade. Between the arched locking portion 158 and the breakaway portion 152 , breakaway notches 160 are preferably formed to allow for easy removal of the breakaway portion after the molding process is complete.
Cutaway side and front views demonstrating the operative alignment of the wire-pressing blade pairs 111 and the wire-cutting sets 150 within the impact tool head of the present invention are presented in FIGS. 14 and 15, respectively. In manufacture, a mold cavity of an injection mold apparatus is preloaded with one or more pairs of pressing blades 111 and two wire-cutting blade sets 150 such that the breakable portion 125 of the pressing blade pairs 111 (see FIGS. 11 and 12) resides in the portion of the mold which will form the longitudinal groove 103 of the impact head; such that the pressing blade pairs 111 reside so that after molding they will be substantially planar with the generally planar surface 109 of the impact tool head; and such that the after molding, the bevel-shaped cutting ends 156 of the wire-cutting blade sets 150 extend perpendicularly beyond the generally planar surface 109 of the impact tool head. The number of pressing blade pairs 111 equals the number of cutting blade portions 115 in each wire-cutting blade set 150 (see FIG. 13 ). The exact number of pressing blade pairs 111 and cutting blade portions 115 is tailorable to the requirements of a particular terminal block. Additionally, dimensions of the wire-pressing blade pairs 111 and the wire-cutting blade sets 150 may be chosen for compatibility with a particular terminal block. These dimensional choices include not only the overall scale, but also the dimensions of particular features of the individual pieces, e.g. adjustment of the depth of the straddle portion 123 of the pressing blades 111 to accommodate different wire contacts or of the length of the cutting blade portions 115 of the wire-cutting blade sets 150 to vary the distance by which the bevel-shaped cutting ends 156 extend beyond the generally planar surface 109 of the impact tool head. During the molding process, various means for attaching the impact tool head may be included, depending on needs of the impact device with which it is to be used, e.g. threaded holes in the molding material, shoulders 117 formed adjacent the cutting blades 115 and opposite the pressing blades 111 (see FIG. 10 ), etc. After molding, the breakable portion 125 (see FIGS. 11 and 12) is removed from the longitudinal groove 103 of the impact tool head to clear it from obstruction. The breakaway portions 152 of the wire-cutting blade sets 150 are also removed.
A perspective and partial cut-away view of an example of a terminal block with which the impact tool head of the present invention would be used is shown in FIG. 16 . In this particular case, the terminal block shown is configured as a Lucent RJ-45 terminal block. However, the impact tool head of the invention can be configured compatibly with any geometrically similar configuration. As shown in the figure, the terminal block is of a generally block shape, and includes a two substantially planar ridges 200 formed on either side of a longitudinal wire receptacle 202 . A plurality of wire terminal grooves 204 , each including an electrically conductive contact 206 therein, are formed in the substantially planar ridges 200 . Individual wires 208 from a multiple-wire cable 210 are placed in an operative relationship with the wire terminal grooves 204 as shown, such that they may be pressed and cut by the impact tool head. The terminal block of the example further includes longitudinal anvil-ridge portions 212 along its exterior, positioned to act as anvils against which the individual wires 208 may be cut as they are seated in the terminal grooves 204 . The electrically conductive contacts 206 are designed such that they penetrate and form an electrical connection with the individual wires 208 as they are seated within the terminal grooves 204 .
A diagrammatic representation of the impact tool head demonstrating its use in operative alignment with, and actuated against a terminal receptacle of a terminal block of the type shown in FIG. 16, such that it is operative to seat and cut a wire in a wire terminal groove of the terminal block is presented in FIG. 17 . Here, the dimensions of the impact tool head have been selected to fit the particular terminal block such that the distance 250 between the wire-cutting blade sets 150 provides sufficient clearance for the terminal block body 252 to fit and to be guided therebetween. The height 254 by which the pressing blade pairs 111 extend from the support body block 101 is chosen such that when the impact tool head is actuated against the terminal block, the pressing blade pairs 111 extend into the wire terminal grooves 204 of the terminal block (see FIG. 16 ), pressing the individual wires 208 into them. Also, the dimensions of the straddle portions 123 of the pressing blades pairs 111 are chosen such that they do not contact the electrically conductive contacts 106 (see FIG. 16 ), but still press the individual wires 208 onto the electrically conductive contacts 106 with sufficient force to cause the electrically conductive contacts 206 to penetrate and electrically contact the individual wires. Furthermore, the distance 256 by which the cutting blades 150 extend beyond the generally planar surface 109 of the impact tool head (see FIG. 1 also) is chosen such that when the impact tool head is actuated against the terminal block, the cutting blades 150 cut the wires 208 against the longitudinal anvil-ridge portions 212 of the terminal block (see FIG. 16 also), leaving wire clippings 258 . Additionally, the longitudinal groove 103 of the impact tool head is geometrically configured to accommodate the multiple-wire cable 210 residing in the longitudinal wire receptacle 202 of the terminal block.
The multiple component design of the impact tool head disclosed herein, although described above in a configuration compatible with an RJ-45 terminal block, is readily adaptable to other terminal block configurations. An example of a second preferred embodiment of the impact tool head is a design for use with a single strip of a Lucent 110-style terminal block is shown in perspective view in FIG. 18, utilizing one set of cutting blades 302 and pressing blades 300 configured as unitary pressing blades set into the impact tool head block 304 . A cutaway drawing of the second preferred embodiment of the impact tool head aligned with, and actuated against, a single strip of a Lucent 110-style terminal block is shown in FIG. 19 . In this figure, the impact tool head 304 is actuated against the terminal block 306 , causing the cutting blades 302 and the pressing blades 304 to respectively seat and cut a terminal wire 308 therein. Using an impact tool head with this configuration, a number of wires may be seated and cut at one time along a strip. Additionally, though not shown in the figures, the impact tool head disclosed herein may be adapted to seat and cut wires along two or more strips of a terminal block having a configuration geometrically similar to that of a Lucent 110-type terminal block.
As can be seen by the preferred embodiments above, the design of this impact tool head may be easily adapted to the requirements of many more terminal blocks than presented. Thus, foregoing descriptions of the preferred embodiments of the invention have been presented for purposes of illustration and description. It is neither intended to be exhaustive nor to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is directed to an improved continuous crumbing machine for recycling rubber tires and other materials such as polyethylene containers, gypsum, hardboard, tin cans, glass jars and bottles. The device comprises a pair of rotating rolls having negative rake teeth of interlocking sprocket design formed on the outer periphery of each roll. The materials to be fragmented or crumbed are fed between pairs of rotating rollers having negative rake teeth. A plurality of stages of rotating rollers are placed in series to obtain the desired particle size.
2. Description of the Related Art
The following patents are directed to the crumbing and shredding of rubber tires:
______________________________________Patent Number Inventor Date______________________________________3,843,061 Hammelmann 19744,235,383 Clark 19804,614,308 Barclay 19864,757,949 Horton 1988.______________________________________
Barclay & Horton are directed to continuous processes. Barclay employs a plurality of stator blades which intermesh with rotor blades mounted on a central, vertical shaft. The Barclay device is massive, the rotors being about 48 inches in diameter (See Col. 7, lines 16-30 of the Barclay patent).
Horton has transversely disposed cutter wheels on adjacent parallel horizontal shafts. The shafts rotate at different speeds ranging from about 20-34 RPM for the first shaft, and about 26-42 RPM for the second shaft, the speed of the second shaft being about 6 RPM faster.
Horton appears to be the closest reference, but Horton employs cutter wheels instead of negative rake teeth integrally formed into rotating rolls, as in the subject invention. Horton's differential RPM ratio is never as great as the subject invention, which may range from 4:1 to 25:1. Horton obtains particle sizes of one to two inches, and does not mention steel wire removal. In addition, Horton employs cutter wheels instead of negative rake teeth.
Hammelmann's apparatus receives successive tires, stretches them and subjects the tires to a high speed water jet. Clark employs abrasive, counterrotating wheels to disintegrate a tire which is fed into the nip between the wheels in an upright position.
SUMMARY OF THE INVENTION
This invention comprises an improved continuous crumbing machine for recycling rubber tires, including steel-belted ones, and other materials, such as polyethylene containers, gypsum, hardboard, tin cans and glass containers. The apparatus is capable of taking a steel-belted tire from its original configuration down to its component parts. The wire in the steel belts is substantially completely separated from the rubber "crumbs", which are typically 40 mesh or smaller at the finish of the process.
The apparatus of the instant invention substantially removes the steel wire from steel belted tires and produces a fine, granular crumb material in the range of about 40 mesh or less, which is entirely suitable for making various recycled products, including membranes on landfills, rubber conduits, bed liners, floats for nautical use, and various formed objects.
The apparatus of the invention preferably comprises a plurality of pairs of heavy rollers (about 12-20" diameter ) which are disposed horizontally adjacent to each other, and which rotate downwardly and inwardly towards each other. The opposed roller surfaces have integral, negative rake teeth which intermesh along the length of the rollers so that an incoming object is gripped, compressed and torn apart by the rollers.
The opposed rollers rotate at different speeds in the ratio of 4:1 to 25:1 RPM to further increase the tearing and comminuting action as the incoming object is fed down into the nip of the opposing rollers. The rollers are driven by a drive system capable of developing 100,000 to 5,000,000 inch lbs. of torque at the nip between the rollers determined by the size of the rollers, and the material being comminuted.
A second and third tier of similar opposed roller pairs are normally disposed below the first tier to receive the partially crumbed material and to comminute it further. The second and third tiers of roller pairs are capable of comminuting (crumbing) a steel belted rubber tire down to 40 mesh or less in particle size, and to substantially completely separate the steel wire from the rubber crumb.
A magnetic separator is used to remove all steel particles from the finely powdered crumb. The rubber crumb is then used to make various recycle products, such as rubber membranes for landfills, rubber conduits, bed liners, floats for nautical use and formed objects. In addition to crumbing steel-belted tires, the apparatus may be used to disintegrate and comminute polyethylene containers, gypsum, hardboard, tin cans, glass jars and bottles.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 of the drawings is a perspective view of one of the crumbing rollers having integral grooves, but prior to machining the integral teeth on it;
FIG. 2 is an enlarged, schematic end view of two intermeshing crumb rollers;
FIG. 3 is a schematic, top plan view of a pair of intermeshed crumb rollers with the intermediate, intermeshing teeth and grooves omitted;
FIG. 4 is a schematic end view of a three stage crumbing machine with parts omitted; and
FIG. 5 is an enlarged schematic end view showing the profile of the negative rake teeth on the periphery of the crumb rollers.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 1, crumb rollers 10 each have an integral drive axle 11, and a shorter, integral support axle 12. The cylindrical body 13 of each crumb roller 10 is shown in an intermediate stage of manufacture, in which a plurality of transverse, integral grooves 14 have been machined on the peripheral surface 15 of the crumb roller 10 to define ridges 16.
Intermeshing, integral teeth 17 are machined into the ridges 16, as shown in FIG. 2. Crumb rollers 10 are disposed horizontally parallel to each other so that the integral teeth 17 of one roller 10 are disposed in the grooves 14 of the opposing roller 10. The rollers 10 are disposed more closely together than is shown in FIG. 2 for optimum crumbing action. The preferred clearance between outer tips 17a of teeth 17 and bottom 14a of groove 14 is about 0.001 to 0.250 inch, with the clearance being adjustable for different materials.
FIG. 3 shows only some of the grooves 14 and the ridges 16 which carry the teeth 17. The grooves 14, ridges 16 and teeth 17 extend along the complete length of each roller 10. The drive axle 11 are disposed at opposite ends of the assembled pair of crumb rollers 10 to simplify space requirements for the respective independent drives.
Rollers 10 are typically about 12-20 inches in diameter in a typical three-stage crumbing machine for crumbing steel belted tires. The diameter of the rollers 10 is determined by the particular material to be disintegrated. Rollers 10 rotate downwardly and inwardly towards each other. The opposing rollers 10 are independently driven to rotate at different speeds, preferably in the range of speed ratios from 5:1 to 25:1. The rotational speed differential greatly enhances the crumbing action, and makes possible the complete separation of the steel belting wire material from the rubber of the steel-belted tires.
Each crumb roller 10 can be manufactured from a single, solid steel core, and the grooves 14 and teeth 17 may be machined integrally on the outer, peripheral surface 15 of the core body 13. It is important that the finished crumb roller 10 have a Rockwell hardness in the range of 50-70 in order to have significant useful life and wear in the crumbing operation to make the apparatus economically feasible for recycling typical waste materials, such as steel belted tires, polyethylene containers, gypsum, hardboard, tin cans, glass jars and bottles.
The crumb rollers 10 are preferably made from high alloy steels and tool steels, such as AISI A2 and M2. More specifically, AISI Steels #4140, 4150 and 4340 have been used. AISI # 4340 is presently preferred for tire crumbing apparatus. The crumb rollers are heat treated to obtain a Rockwell hardness of 50-70.
For certain comminuting applications, the crumbing rollers 10 can be made of a ceramic material. The important requirement is that the crumbing rollers 10 be harder than the material being comminuted.
A typical crumb roller 10 used for crumbing steel-belted tires has grooves 14 which are about 0.455 inches wide and about 1/12 inches deep. The teeth 17 are about 0.375 inches wide. The outer diameter of these crumb rollers 10 are about 9.6 inches, and their length is about 33-40 inches, not including the axles 11 and 12.
As shown in FIG. 4, the crumb rollers 10 are typically arranged in horizontally disposed stages 18, 19 and 20, each stage comprising a pair of horizontally disposed, closely intermeshing crumb rollers 10. Material to be crumbed, such as steel-belted tires, or tire fragments 21, is fed into stage 18 to produce a first stage crumb 22, which drops by gravity into the nip between crumb rollers 10 of second stage 19. Second stage 19 produces a second stage, finer crumb 23 which falls by gravity into the nip between the crumb rollers 10 of the third stage 20. Third stage 20 produces a final stage powdered crumb 24, substantially completely separate from steel wire 24a. Steel wire 24a can then be removed from the powdered crumb product 24 by means of a magnetic separator (not shown).
As can best be seen in FIG. 5, an important feature of this invention is the negative rake teeth 17. It has been discovered that a rake of about 30 degrees measured between the radius of the roller and the transverse side surfaces of each of the teeth 17. The negative rake teeth 17, in combination with the differential rotational rates of the pairs of crumbing rollers 10, insures optimum crumbing action for tires, or tire fragments 21, first stage crumb 22, and second stage crumb 23, to produce a finely powdered crumb 24, from which all the steel wire 24a can be removed, as by magnetic separation.
In a typical first stage 18, the crumb rollers 10 have about 40-72 teeth, equally spaced around the circumference of a 10-12 inch diameter roller 10. About 60 teeth around the periphery of the first stage roller 10 is preferable. Side clearances between the teeth 17 of the opposing first stage rollers 10 is about 0.050 inch, and the diametrical clearance between teeth 17 and the opposing groove 14 of the opposing roller 10 is about 0.060 inch. The width of the teeth 17 in the first stage 18 is preferably about 0.355 inch for a roller 10 about 30 inches long.
For the typical second stage 19, the crumb rollers 10 also have 40-72 teeth 17 around the periphery of a 10-12 inch diameter roller 10, and about 60 teeth 17 around the second stage roller 10 is again preferred. Side clearance between the opposing teeth 17 of the opposing rollers 10 in the second stage 19 is reduced to about 0.040 inch, and the clearance between the teeth 17 and the opposing groove 14 is reduced to about 0.050 inch. The teeth 17 have a width of 0.355 inch, as in the first stage 18.
The crumb rollers 10 in the typical third stage 20 have about 60 to 90 teeth around the circumference of the third stage rollers 10, which are about 10-12 inches in diameter. At present, when the third stage rollers 10 are 12 inches in diameter, 72 teeth 17 around the periphery of the roller 10 is preferred. Teeth width for the third stage crumb rollers 10 is preferably about 0.310 inch, which is less than in the first two stages 18 and 19. The side clearances between the opposing teeth 17 of the third stage rollers 10 is also reduced, being about 0.025 inch. The clearance between the teeth 17 and the grooves 14 of the opposing roller 10 in the third stage 20 is in the range of 0.015 to 0.045 inch, and is preferably about 0.035 inch, which is less than the same clearance in the preceding stages 18 and 19.
The left and right crumb rollers 10 in each stage 18,19 and 20 are each provided with an independent drive motor (not shown) to drive the rollers 10 in all the stages 18, 19 and 20 of the crumbing machine through their respective drive axles 11. Reduction gears can be provided so that the rate of rotation of each roller 10 can be adjusted as required.
The drive motor for the left (slow speed) side of stages 18, 19 and 20 may be an A. C. electric motor capable of driving the left set of drive axles 11 and their respective rollers 10 in stages 18, 19 and 20 to develop a torque of 100,000 to 5,000,000 inch pounds under load. The drive motor for the right (high speed) side drive axles 11 may be a D. C. electric motor, and is connected to drive the right set of drive axles 11 of the right 1-5 set of rollers 10 to develop a torque of 100,000 to 5,000,000 inch pounds, also.
Controls (not shown) for the drive motors enable the operator of the apparatus to adjust the rotational speeds of the left set of rollers 10 in the stages 18, 19 and 20 separately from the rotational speeds of the right set of rollers 10 in stages 18, 19 and 20 to obtain a rotational differential between the right and left sets of rollers 10 ranging from 4:1 to 25:1.
Hydraulic drive motors (not shown) can also be used for either the left or the right side crumb rollers 10 in each stage 18, 19 and 20. In fact, any combination of hydraulic, diesel, AC, and D.C. drives may be used, so long as the RPM and torque requirements are met. The RPM of the crumb rollers 10 on the low speed side may range from about 1/2 to about 25 RPM. The high speed side crumb rollers 10 may typically range from 10 to 250 RPM. It is the speed differential between the left and right side rollers 10 in the respective stages 18, 19 and 20 in combination with the negative rake teeth which gives the excellent crumbing action.
When there is considerable heat buildup in the crumb rollers 10 in a particular tire crumbing application, the last stage 20 crumb rollers 10 may be provided with cooling means. The crumb rollers 10 may be cored out, for example, and cooled with chilled water to bring the temperature of the crumb 23 entering the final stage 20 down to about 30 degrees F. The cooling produces a better final crumbing action, and improves crumbing efficiency.
The above description applies primarily to effective crumbing of steel-belted tires. It is also contemplated that other materials may be comminuted or crumbed using the overall system of the invention. Tests are presently being conducted to determine the optimum conditions for crumbing or comminuting other materials such as "EPDM", "SBR", "VITON" (chemically resistant synthetic rubber) and silicone rubber chunks. It is presently believed that the crumbing rolls 10 will be operated within the general parameters set forth above.
Other teeth configurations may be more effective for crumbing the last-named materials. For some applications, the negative rake teeth 17 described above may be spaced at intervals around the outer periphery of the crumbing rolls 10 with an elongated ridge (not shown) filling in the intervals between the teeth 17. It is also possible that other teeth shapes may be more effective for crumbing certain materials. Teeth which are hook-shaped in profile are being considered for the crumbing of silicone rubber chunks.
This invention makes possible the efficient recycling of high volume, extremely durable materials, such as steel-belted rubber tires, which are practically non-degradable in landfills. The resulting crumb products are in high demand for reprocessing into similar, or different products. These second generation products can also be crumbed and recycled again and again, using the system of the present invention, thereby greatly reducing the loading up of overtaxed landfills, and providing a recycling economic bonus as well. | 4y
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BACKGROUND OF THE INVENTION
[0001] 1. Field of Invention
[0002] The present invention relates generally to the field of fluid transfer, and more specifically to submersible and surface pump apparatus and systems and methods of making and using same.
[0003] 2. Related Art
[0004] Vertical and horizontal centrifugal pump systems are designed to operate in downthrust mode, where pressure inside the pump case by action of the pump impellers tends to exert an axial force on the pump shaft toward the suction inlet. Most pump and motor manufacturers instruct users not to operate these pumps in upthrust mode, where pressure exerted by pumped fluid against the impellers at the suction inlet may result in damaged impellers, a damaged pump shaft, and damaged pumps seals and bearings. Upthrust conditions may exist at startup, when operating at high flow rates, and/or when the specific gravity of the fluid being pumped changes. In the upthrust condition, bearings may not be cooled sufficiently due to lack of recirculation and may fail. Some pump manufacturers use a disk-type upthrust pad at the discharge/exit area of the pump to limit the upthrust movement of the shaft. Other pump manufactures have used combinations of a grooved upthrust pad in the diffuser and grooved radial bore in the diffuser to prevent the loss of lubrication to the bearing in the upthrust condition. These approaches are not always successful.
[0005] It is evident that there is a need in the art for pump apparatus and methods which more adequately address the upthrust condition problem.
SUMMARY OF THE INVENTION
[0006] In accordance with the present invention, coupling members, systems including same, and methods of making and using same are described that reduce or overcome problems in previously known apparatus and methods. Apparatus of the invention comprise a securing mechanism to limit upthrust, or limit the tendency of a pump shaft going into the upthrust condition, and therefore reduce or prevent failure. In systems of the invention one shaft, such as a pump shaft, is secured axially and rotationally to the coupling, and the coupling is in turn secured axially and rotationally to a second shaft, such as a thrust chamber shaft.
[0007] A first aspect of the invention is coupling members adapted to connect a first shaft, such as a pump shaft, with a second shaft, such as a thrust chamber shaft. The coupling members of the invention are adapted to connect a first shaft with a second shaft, the coupling member comprising means for transmitting rotational movement between the shafts and means for securing the shafts from substantial axial movement during rotation of the shafts and coupling member, the coupling member including at least one torque-limiting element. The first shaft may be a pump shaft while the second shaft may be a thrust chamber shaft, although the invention is not so limited. Any means for securing the first and second shafts to the coupling member may be used, including any combination of male/female connections, as long as the transmission of rotational motion and axial securing functions are achieved. For example, coupling member may have dual female receptacles for accepting ends of the shafts; one side of the coupling member may have a female receptacle while the other has a male portion connecting to a female portion of the other shaft, and so on. In certain embodiments, the coupling member defines a first axial chamber adapted to accept a first end of the first shaft, and a second axial chamber adapted to accept a first end of the second shaft, the axial chambers separated by a coupling plate, which in some embodiments has a through hole adapted to accept a male portion of an axial motion securing member, and in other embodiments is a solid plate. The means for transmitting rotational movement may be selected from splines, pins, bolts, rivets, clamps, rings, threads, grooves, gears, bearings, collets, or other equivalent functional elements. The coupling members may also include axial motion securing elements in the first and second axial chambers for axially securing the shafts in the coupling member.
[0008] For convenience only, the first shaft is hereinafter referred to as the pump shaft, and the second shaft is referred to as a thrust chamber shaft, however, those of skill in the art will recognize that the inventive coupling members, systems, and methods may be used when coupling any two rotating shafts.
[0009] The inventive coupling members may be used in systems of the invention, which comprise a second aspect of the invention. Systems of the invention comprise a coupling member connecting a first shaft with a second shaft, the coupling member comprising means for transmitting rotational movement between the shafts and means for securing the shafts from substantial axial movement during rotation of the shafts and coupling member, the coupling member including at least one torque-limiting element. In certain embodiments, the first end of the pump shaft, or a sub-shaft or component intermediate of the pump shaft first end is axially secured in the inventive coupling member. One way of accomplishing this is by virtue of a female aperture or receptacle extending inwardly from the pump shaft first end a certain distance and accepting a male portion of a pump shaft axial securing member, the female receptacle and the male portion of the pump shaft axial securing member being threaded in matching relationship. The pump shaft axial securing member may have a head, forming with the male portion a bolt. In these embodiments the male portion protrudes through a central through hole in a coupling plate and threadingly engages the threads in the female receptacle, while the head engages the coupling plate, thus axially securing the pump shaft to the coupling member upon tension forces, in other words, forces tending to move the pump shaft axially away from the coupling plate, such as during upthrust conditions.
[0010] Alternatively, systems of the invention include those wherein the female receptacle in the pump shaft first end may comprise one or more grooves, such as J grooves, while the male portion of the pump shaft adjusting member includes one or more radially extending pins or other protuberances, the pins sliding into matching respective grooves and engaging a portion of the groove to axially secure the pump shaft. Other shaped grooves may of course be used, as long as the securing function is achieved. In certain system embodiments the pump shaft may be axially secured to the coupling member by one or more pins inserted through matching transverse passages through walls of the coupling member which define the first chamber and through a corresponding transverse passage in the pump shaft. The pin or pins may be tapered, threaded their whole or a portion of their length, or held by cotter pins. The pins may comprise any shape and material sufficient to provide the axial securing function, that is, of retaining the axial position of the pump shaft and coupling member so that the pump and motor thrust bearings are not damaged by upthrust or other conditions. Alternatively, to avoid forming a passage through the pump shaft, the pump shaft may be modified on its outer surface proximate the first chamber inner wall to be threaded or accept a threaded collar which also has threads on its outer surface and mating with threads on the inner wall of the first chamber. A two-piece ring, a snap ring, or combination thereof, or other axial securing retainer, as described further herein, may be employed. Alternative embodiments include those wherein the pump shaft first end comprises a female receptacle, while the coupling member comprises a male member. Any of the mentioned securing means may be used in these embodiments.
[0011] In certain system embodiments the pump shaft axial securing member is adjustable, such as when the male portion is threaded and meshes with a threaded receptacle in the pump shaft or intermediate component, or when the pump shaft end is threaded or a threaded collar is used. This has certain advantages as will be discussed herein. In addition, one or more pump shaft shims may be positioned between the coupling plate and the first end of the pump shaft, the male portion of the pump shaft axial securing member passing through the shims and through the coupling plate. The pump shaft shims, if used, may comprise a material that is the same as or different from the coupling member material and the pump shaft. In certain embodiments the pump shaft, pump shaft shims, and coupling member are all of the same material. The pump shaft axial securing member head may include surfaces allowing the head to be turned by a tool, such as a wrench, screw driver or other tool. The pump shaft axial securing member head may or may not be the same material as the male portion.
[0012] Systems of the invention include those wherein the thrust chamber shaft is axially secured in the second chamber. In certain embodiments the thrust chamber shaft is axially secured to the coupling member by a two-piece ring and snap ring. Alternatively, one or more pins may be inserted through matching transverse passages through walls of the coupling member which define the second chamber and through a passage in the thrust chamber shaft. The pin or pins may be tapered, threaded, or held by cotter pins. The pins may be comprised of any shape and material sufficient to provide the axial securing function, that is, of axially securing the relative position of the thrust chamber shaft and coupling member so that the pump and motor thrust bearings are not damaged by upthrust or other conditions. Alternatively, to avoid forming a passage through the thrust chamber shaft, the thrust chamber shaft may be modified on its outer surface proximate the second chamber inner wall to be threaded or accept a threaded collar which also has threads on its outer surface and mating with threads on the inner wall of the second chamber. Alternative embodiments include those wherein the thrust chamber shaft first end comprises a female receptacle, while the coupling member comprises a male member. Any of the mentioned securing means may be used in these embodiments.
[0013] In embodiments employing a coupling plate, the coupling plate may be positioned anywhere internally of the coupling member as long as it separates the two chambers and serves the pump shaft axially securing function in conjunction with the pump shaft axial securing member. The coupling plate may be integral to the coupling member body or a separate piece inserted into the coupling member body. Further, the coupling plate is only required when using a bolt to secure the coupling member to one of the shafts. Apparatus and systems of the invention include those wherein the coupling member is cylindrical in shape, as are the first and second axial chambers. However, neither the axial chambers nor the portions of the shafts which fit therein are required to be cylindrical in shape. In fact, square shafts, hex shafts or any other of a number of configurations could be employed for engaging the chambers or shafts together. The coupling member and coupling plate (if present) may be all one and the same material, but this is not required. Combinations of different materials may be used as desired. The coupling plate may have two substantially parallel surfaces substantially perpendicular to the longitudinal axis of the pump shaft and thrust chamber shaft. In these embodiments the pump shaft axial securing member interacts with the coupling plate by way of a head that abuts against a surface of the coupling plate that faces the thrust chamber shaft. In other embodiments, the side of the coupling plate facing the thrust chamber shaft may have a recessed area that accepts the head of the pump shaft axial securing member so that it abuts the recessed area, allowing the first end of the thrust chamber shaft to be positioned substantially flush against the coupling plate. In certain embodiments the coupling plate is positioned approximately midway between the ends of the coupling member. Apparatus and systems of the invention include those wherein the first and second axial chambers of the coupling member have equal diameters, apparatus and systems wherein the chambers have different diameters, and apparatus and systems wherein one or both axial chambers have truncated conical shape.
[0014] Apparatus and systems of the invention include a torque-limiting feature functioning to physically break the coupling member upon exposure to excessive torque conditions. One such feature is a portion of the coupling member having a reduced thickness cross section, as described more fully herein. The reduced thickness cross section or sections may be positioned anywhere, but in certain embodiments it may be advantageous to place one reduced thickness portion approximately at the axial midpoint of the coupling member, or between the coupling plate (if present) and one of the ends of the coupling member, either on the thrust shaft side or the pump shaft side of the coupling member. Two or more reduced thickness portions may be envisioned in certain other embodiments. The reduce thickness cross sections may be annular grooves or depressions of any shape. Alternatively, or in conjunction with reduced thickness cross sections, apparatus and systems of the invention may include one or more radially and/or longitudinally extending shear pins. Another alternative is the use of spring-load mechanisms, such as spring-load ball and groove features.
[0015] Another aspect of the invention are methods of making a locked pair of shafts, one method of the invention comprising:
[0016] (a) measuring axial shaft movement of first and second shafts during operation using a standard coupling;
[0017] (b) selecting a coupling member to limit the axial shaft movement; and
[0018] (c) installing the coupling member to limit the axial shaft movement.
[0019] Methods of the invention include those wherein the selecting a coupling member to limit shaft movement includes calculating the width and/or number of shaft shims required to limit the axial shaft movement, and installing one or more shaft shims in the coupling by bolting or other means. In one embodiment, the first shaft is a pump shaft that is axially secured using a bolt and optional shaft shims, while the second shaft is a thrust chamber shaft that is secured axially to the coupling using one or more pins, bolts, or other means. In horizontal and other pumping systems, the pin (or bolt or screw) may be inserted through the intake of the pump.
[0020] Yet another aspect of the invention are methods of pumping fluids, one method comprising:
[0021] (a) determining a pumping requirement for transferring a fluid;
[0022] (b) selecting a pump having a pump shaft, and a driver having a driver shaft;
[0023] (c) coupling the pump shaft and driver shaft axially using a coupling member of the invention; and
[0024] (d) pumping the fluid using the pump to meet the pumping requirement.
[0025] Apparatus and systems of the invention may be used downhole pumping systems, in submersible pump systems, and in horizontal pumping systems, and may be used between any two shafts in such systems, such as shafts between a driver and a pump, between two pump sections, between a pump and an auxiliary device such as an auger or other fluid transmission device. In pumping systems including motors, especially downhole pumping systems, the systems may include a motor protector, which may or may not be integral with the motor, and may include integral instrumentation adapted to measure one or more downhole parameters. Pump systems employing apparatus and systems of the invention may be adapted to produce a dynamic head up to 7,500 feet or more. The driver shaft may be one and the same as the pump shaft in certain embodiments, and in certain other embodiments the pump shaft may be mechanically coupled to and driven by the driver shaft. In other embodiments, the driver shaft and the pump shaft may be distinct and not be coupled mechanically, such as in magnetic couplings wherein the driver shaft drives a magnetic coupling comprising magnets on the driver shaft which interact with magnets in a protector, in which case the protector shaft mechanically connects to and drives the pump shaft.
[0026] Apparatus and methods of the invention will become more apparent upon review of the brief description of the drawings, the detailed description of the invention, and the claims that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The manner in which the objectives of the invention and other desirable characteristics can be obtained is explained in the following description and attached drawings in which:
[0028] FIGS. 1-3 illustrate schematically in side-elevation, partial cross-sectional views of a prior art horizontal pumping system, and certain problems therewith; and
[0029] FIGS. 4-19 illustrate schematically in side elevation, partial cross-sectional views, of non-limiting embodiments of apparatus, systems, and methods of the invention.
[0030] It is to be noted, however, that the appended drawings are not to scale and illustrate only typical embodiments of this invention, and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
DETAILED DESCRIPTION
[0031] In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
[0032] All phrases, derivations, collocations and multiword expressions used herein, in particular in the claims that follow, are expressly not limited to nouns and verbs. It is apparent that meanings are not just expressed by nouns and verbs or single words. Languages use a variety of ways to express content. The existence of inventive concepts and the ways in which these are expressed varies in language-cultures. For example, many lexicalized compounds in Germanic languages are often expressed as adjective-noun combinations, noun-preposition-noun combinations or derivations in Romanic languages. The possibility to include phrases, derivations and collocations in the claims is essential for high-quality patents, making it possible to reduce expressions to their conceptual content, and all possible conceptual combinations of words that are compatible with such content (either within a language or across languages) are intended to be included in the used phrases.
[0033] The invention describes coupling members, systems incorporating same, and methods of making and using same for pumping fluids, for example, to and from wellbores, although the invention is applicable to pumps designed for any intended use, including, but not limited to, so-called surface fluid transfer operations. A “wellbore” may be any type of well, including, but not limited to, a producing well, a non-producing well, an experimental well, and exploratory well, and the like. Wellbores may be vertical, horizontal, some angle between vertical and horizontal, and combinations thereof, for example a vertical well with a non-vertical component. As discussed, vertical and horizontal centrifugal pump systems are designed to operate in downthrust mode, where pressure inside the pump case by action of the pump impellers tends to exert an axial force on the pump shaft toward the suction inlet. Most pump and motor manufacturers instruct users not to operate these pumps in upthrust mode, where pressure exerted by pumped fluid against the impellers at the suction inlet may result in damaged impellers, damage the pump shaft, and damaged pumps seals and bearings. Upthrust conditions may exist at startup, when operating at high flow rates, and/or when the specific gravity of the fluid being pumped changes. In the upthrust condition, bearings may not be cooled sufficiently due to lack of recirculation and may fail. Previous approaches to solving these problems are not always successful.
[0034] Given that there is considerable investment in existing equipment, it would be an advance in the art if upthrust conditions and their consequences could be avoided or reduced, and further if a torque-limiting feature could be included, so that more expensive components, such as shafts, do not fail before less expensive components, such as couplings. This invention offers methods and apparatus for these purposes. A torque-limiting element is placed in the coupling members of the invention for the purpose of having the coupling “fail” at a specified torque value generally less than the value needed to “fail” either of the shafts. “Failure”, as used herein, means limiting the ability of the coupling to transmit torque between the two shafts. This can be accomplished in any number of ways including appropriate choice of a coupling material(s), employing the use of one or more grooves on the OD or ID of the coupling having a variable length and depth so as to limit the cross sectional area and thus the strength of the coupling to a predetermined value. The depth of the grooves may be equal to zero depending on the design and/or choice of material. Use of one or more radial or longitudinal “shear” pins may provide the torque-limiting feature. Another means for torque limiting employs the use of a press fit member designed to slip under a given torsional load. Spring loaded mechanisms and cam loaded mechanisms may be used. Any combination of these means may be employed in a given situation.
[0035] FIGS. 1-3 illustrate schematic side-elevation, partial cross-sectional views of a prior art horizontal pumping system 100 , useful for illustrating certain problems therewith. FIG. 1 illustrates a motor 2 , horizontal pump 4 having a pump inlet 6 and a pump outlet 8 , and a thrust chamber 10 . Motor 2 is supported on a surface 18 by a motor support 12 , and pump 4 is supported by pump supports 14 and 16 . Surface 18 may be earthen, concrete, metal, or virtually any structural support member. Thrust chamber 10 has thrust bearings (not illustrated) for carrying the downthrust, indicated by arrow DT in FIGS. 1 and 2 produced by pump impellers 24 . As more clearly illustrated in FIGS. 2 and 3 , thrust chamber 10 connects a thrust chamber shaft 20 to a pump shaft 22 through a coupling 26 to transmit torque and rotation speed using splines 28 and 30 . Shaft shims 32 are used for preventing the downward movement of the shaft so that all the down thrust produced by pumping action is transferred to the thrust bearings in the thrust chamber. Pump shaft 22 is free to move horizontally to the right in FIGS. 1-3 (or in the axial direction) allowing the stages to go in the upthrust, indicated by large arrow UT and small arrows 34 ( FIG. 3 ).
[0036] FIGS. 4-19 illustrate schematic side-elevation, partial cross-sectional views, not necessarily to scale, of apparatus, systems, and methods of the invention only as examples, but the invention is not so limited, and are presented only for explaining some of the inventive concepts. FIG. 4 illustrates system embodiment 200 of the invention. Coupling member 35 has a first axial chamber in which a first end of pump shaft 22 is fitted with spline connections 30 , and a second axial chamber into which thrust chamber shaft 20 is fitted with spline connections 28 , as in previously known coupling members. However, in addition coupling member 35 has a threaded female aperture 38 extending from the end of the pump shaft inwardly a certain distance, determined by the particular tension loads expected, the materials of construction, and the like. Coupling member 35 includes in embodiment 200 a coupling plate 37 having a central through hole 40 . Threaded male member 36 threadingly fits with mating threads of threaded female aperture 38 . Male member 36 includes a head 42 which engages a transverse surface of coupling plate 37 inside of a recessed portion 43 of thrust shaft 20 . Coupling member 35 also includes in embodiment 200 a pair of transverse through holes 45 and 47 in the wall forming the second axial chamber of coupling member 35 through which a pin 49 is tightly fitted. A similar size through hole 51 in thrust chamber shaft 20 at a matching location accepts pin 49 . The arrangement of through holes 45 , 47 , and 51 with pin 49 serves the functions of transferring torque from thrust chamber 20 to coupling member 35 and axial tension forces. A torque-limiting feature 46 may be included, in this embodiment a groove or thin region of the wall of coupling member 35 . Torque-limit feature 46 , if present, functions as a failure mechanism, so that coupling member 35 may fail, rather than more expensive components, such as shafts 20 , 22 .
[0037] In use, pump shaft 22 movement in upthrust and downthrust conditions may be measured. Shaft shims 44 having a central through hole through which shaft 36 threadedly fits may be employed as desired. Based on the measured or observed axial movement of pump shaft 22 , the length (or number) of shaft shims 44 required is calculated so that pump shaft 22 has limited movement. During installation, the required number of shaft shims 44 and pump shaft 22 are bolted to coupling member 35 with bolt 26 , 42 . The pump is then installed, for example in a horizontal skid. Pump shaft 22 is rotated so that the radial hole 45 in coupling member 35 and though hole 51 in thrust chamber shaft 20 match. Pin 49 , which may also be a bolt, or screw, is used to secure coupling member 35 with thrust chamber shaft 20 . The securing device may be installed through pump intake 6 .
[0038] In certain embodiments of the invention, a variety of seals, filters, absorbent assemblies and other protection elements may be used to protect motors and other components, particularly if the apparatus and systems of the invention are to used in downhole applications. These components are not illustrated for clarity, but may include, for example, one or more thrust bearings disposed about shafts 20 and 22 to accommodate and support the thrust load from pump 4 . A plurality of shaft seals may also disposed about shaft 20 between pump 4 and motor 2 to isolate a motor fluid in motor 2 from external fluids, such as well fluids and particulates. Shaft seals also may include stationary and rotational components, which may be disposed about the shafts in a variety of configurations. Systems of the invention also may include a plurality of moisture absorbent assemblies disposed throughout housings between a pumps and a motor. These moisture absorbent assemblies absorb and isolate undesirable fluids (for example, water, H2S, and the like) that have entered or may enter housing through shaft seals or though other locations. For example, moisture absorbent assemblies may be disposed about shaft 20 at a location between pump 4 and motor 2 . In addition, the actual protector section above the motor may include a hard bearing head with shedder.
[0039] FIG. 5 illustrates another apparatus and system embodiment 300 of the invention. Coupling member 35 is similar to embodiment 200 depicted in FIG. 4 , with slight differences. Pump shaft 22 is once again held in coupling member 35 via a bolt 36 , 42 , however in embodiment 300 bolt head 42 is set in a recessed area 45 of coupling plate 37 . This allows thrust chamber shaft 20 to be flush at its end up against coupling plate 37 . Another difference is that thrust chamber shaft 20 is secured axially by use of a two piece ring 48 and a snap ring 50 . Two piece ring 48 is held by a groove 53 in thrust chamber shaft 20 .
[0040] Another apparatus and system embodiment 400 is illustrated schematically in FIG. 6 . Comparing to embodiment 300 of FIG. 5 , note that embodiment 400 does not include a threaded bolt to axially secure pump shaft 22 to coupling member 35 , but rather has a threaded collar 52 , having internal threads 54 mating with similar threads on pump shaft 22 , and external threads 56 matching corresponding threads on the inside wall of the first axial chamber of coupling member 35 .
[0041] FIG. 7 illustrates apparatus and system embodiment 500 of the invention. The coupling of thrust chamber shaft 20 to coupling member 35 in embodiment 500 is exactly the same as in embodiments 300 and 400 , however the coupling of pump shaft 20 to coupling member 35 makes use of two pins, bolts, or screws 58 and 60 , which extend through the wall of coupling member 35 an pump shaft 20 in through holes. One pin or more than two pins may be employed as needed, depending on the particular torque requirements materials of construction, environmental conditions, and degree of safety margin desired or required by local laws, and the like.
[0042] FIG. 8 illustrates yet another apparatus and system embodiment 600 , wherein both the pump shaft 22 and thrust chamber shaft 20 are axially secured using two piece rings and snap rings. Thrust chamber shaft 20 is secured axially by use of two piece ring 48 and snap ring 50 . Two piece ring 48 is held by a groove 53 in thrust chamber shaft 20 . In like manner pump shaft 22 is secured axially by use of a two piece ring 48 ′ and a snap ring 50 ′. Two piece ring 48 ′ is held in a groove 53 ′ in thrust chamber shaft 20 .
[0043] FIGS. 9 and 10 illustrate apparatus and system embodiments 700 and 800 , respectively, wherein each embodiment uses the same axial securing features for pump shaft 22 as embodiment 300 of FIG. 5 . In embodiment 700 of FIG. 9 , thrust chamber shaft 20 is axially secured to coupling member 35 using a threaded collar 64 having internal threads 68 matching corresponding threads in thrust chamber shaft 20 , and external threads 66 matching corresponding threads in coupling member 35 . In embodiment 800 of FIG. 10 , thrust chamber shaft 20 is axially secured in coupling member 35 using a tapered pin 70 , having a smaller diameter end 72 . Pin 70 is tightly fit inside through holes 71 and 73 in coupling member 35 wall, and through hole 75 in thrust chamber shaft 20 . More than one pin 70 may be employed, with corresponding through holes.
[0044] FIG. 11 illustrates another apparatus and system embodiment 900 of the invention, which may be explained as a mirror image of embodiment 300 of FIG. 5 . Thrust chamber shaft 20 is axially secured in coupling member 35 via a bolt 36 ′, 42 ′, and bolt head 42 ′ is set in a recessed area 45 ′ of coupling plate 37 . This allows pump shaft 20 to be flush at its end up against coupling plate 37 . Pump shaft 22 is secured axially by use of a two piece ring 48 ′ and a snap ring 50 ′. Two piece ring 48 ′ is held in a groove 53 ′ in pump shaft 20 .
[0045] FIG. 12 illustrates another apparatus and system embodiment 1000 of the invention, identical in all aspects to embodiment 300 of FIG. 5 except for the torque-limit feature. Rather than a groove or thinned wall region 46 as in embodiment 300 of FIG. 5 , embodiment 1000 of FIG. 12 includes a pair of longitudinal shear pins 74 and 76 (one pin or more than two pins may be used). Other torque-limit features, such as radially placed shear pins, radially or longitudinally placed spring-loaded mechanisms, and the like, may be used, and are considered viable options for use in apparatus, systems and methods of the invention.
[0046] FIGS. 13-19 illustrate yet other embodiments of the invention. FIG. 13A illustrates the assembled apparatus embodiment 1100 , and FIG. 13B illustrates a partially exploded view. Embodiment 1100 includes a thrust chamber shaft 20 and pump shaft 22 secured in a coupling member 35 . Splines 28 and 30 are used in spline connections in embodiment 1100 to provide torque transmission. Splines 28 in this embodiment are extended at 31 ( FIG. 13B ) so that they are longer than coupling member 35 . External snap rings 81 and 82 are employed for axially securing the shafts. Groove 77 is provided in shaft 20 ( FIG. 13D ) for external snap ring 81 , while a similar groove is provided in shaft 22 for external snap ring 82 . FIG. 13B also depicts shims 44 , which are optional. Shims 44 have a central through hole 29 ( FIG. 13C ) so that if used they will accept a threaded bolt 80 , which is installed in mating threads 79 in shaft 20 . An unthreaded lead-in 78 is provided to promote assembly of this embodiment. A torque-limit feature may be provided by any of the means discussed herein; in embodiment 1100 , this feature would be provided by the materials of construction of coupling member 35 .
[0047] FIGS. 14A-14D illustrate another embodiment 1200 of the invention. FIG. 14A illustrates the assembled apparatus embodiment 1200 , and FIG. 14D illustrates a partially exploded view without the coupling member. In embodiment 1200 , spline connections 28 , 28 ′, and 30 are once again employed for torque transmission. Securing shaft 20 axially is accomplished by way of a pin (not illustrated) fitting in a through hole 86 in coupling member 35 ( FIGS. 14B and 14C ), and a mating cut out 87 in shaft 20 . Note that cut out 87 is not a through hole in shaft 20 ; this may provide more strength for shaft 20 . Axially securing shaft 22 is accomplished by use of an internal snap ring 50 ′, an external snap ring 83 , and two piece ring 48 , the latter fitting in a channel in shaft 22 ( FIG. 14D ). Internal snap ring 50 ′ fits in a groove 85 in coupling member 35 ( FIG. 14B ). A torque-limit feature may be provided by any of the means discussed herein; in embodiment 1200 , this feature could be provided by the materials of construction of coupling member 35 , as well as the through hole 86 .
[0048] FIGS. 15A-15D illustrate another embodiment 1300 of the invention. Spline connections 28 , 30 are employed for torque transmission. Embodiment 35 does not include a separate coupling member 35 . Rather, coupling of shafts 20 and 22 is through a male/female connection. FIG. 15A is an exploded view of embodiment 1300 , illustrating an external chamfered end 89 of shaft 20 fitting into an internal chamfered end 90 of shaft 22 . A groove 77 in shaft 20 is adapted to hold a wire snap ring 88 , which may be a round wire snap ring. Snap ring 88 is designed to snap into an internal channel 91 in shaft 22 during installation, axially securing shaft 20 to shaft 22 . Spline couplings 28 , 30 , snap ring 88 and groove 91 , and the female end of shaft 22 essentially make up a coupling member. IN this embodiment, shaft 22 is a hollow shaft, as indicated 23 , although the invention is not so limited. As depicted sequentially in FIGS. 15B, 15C , and 15 D, as shaft 20 slides into the female opening in the end of shaft 22 , snap ring 88 is first compressed by chamfer 90 into groove 77 , then with further movement snaps out of groove 77 and into place in channel 91 . Further, as groove 91 provides a reduce wall cross section in the female end portion of shaft 22 , this feature may serve as a torque-limit measure.
[0049] FIGS. 16 and 17 illustrate schematically two similar embodiments 1400 and 1500 , respectively. Both embodiments are illustrated as they might appear prior to assembly. In embodiment 1400 of FIG. 16 , shaft 20 includes a conical aperture 102 that mates with a solid conical terminal section 104 of shaft 22 when assembled. A threaded female section 106 inside of shaft 20 also mates with a threaded male portion 108 of shaft 22 when assembled. Undercuts 114 aid in threading and boring of threads 106 and conical aperture 102 . Another set of threads, 110 on an external portion of shaft 20 , mates with a set of internal threads 112 in coupling member 35 . Coupling member 35 may be a standard nut in this embodiment, fitted with a two piece ring 116 . A round wire snap ring 118 helps to axially secure shaft 22 to coupling member 35 . Threads 112 may serve as a torque-limiting feature, as well as materials of construction of coupling member 35 . FIG. 17 illustrates a similar embodiment 1500 , having a straight aperture 120 in shaft 20 rather than a conical aperture 102 as in embodiment 1400 of FIG. 16 . Straight aperture 120 accepts a pilot extension 122 of shaft 22 which bottoms out in aperture 120 . Other than these differences, embodiments 1400 and 1500 are identical.
[0050] FIGS. 18A-18C illustrate yet another embodiment of the invention. FIG. 18A illustrates an exploded, partial cross-sectional view. In this embodiment, shaft 20 includes a threaded section 124 and a non-threaded terminal section 125 . Non-threaded terminal section 125 accepts a bolt-locking washer 126 , which in turn seats at the end 127 of a bore in the end of shaft 22 . A portion 128 of the bore is threaded to accept threaded section 124 of shaft 20 . Coupling member 35 in this embodiment may comprise a barbed nut having barbs 130 and undercuts 129 ( FIG. 18B ), allowing barbs 130 to deflect inwardly when assembled into chamfer 131 on shaft 22 and down onto threads 124 of shaft 20 . Coupling member or nut 35 has internal threads (not illustrated), and surfaces 132 allowing a wrench or other tool to turn and tighten the assembly. FIG. 18C illustrates the assembled apparatus, partially in cross-section. Both torque and axial forces are transferred by the threads, and additional axial force transmission is supplied by the lock washer 126 and the barbs 130 of coupling member 35 . Torque-limiting may be accomplished by materials of construction of coupling member 35 , or by any other means described herein or their functional equivalent.
[0051] FIGS. 19 and 19 A- 19 D illustrate another embodiment of the invention. Spline connections 28 and 30 are used for torque transfer, while internal circular push on rings 48 and 48 ′, as well as internal snap rings 50 and 50 ′ secure shafts 20 and 22 axially to coupling member 35 . Snap ring 50 fits into a groove 133 in coupling member 35 , while snap ring 50 ′ fits into a groove 85 ′ in coupling member 35 .
[0052] Apparatus, systems, and methods of the invention may be employed in a variety of applications, such as in horizontal pumping systems (“HPS”), such as illustrated generally in FIG. 1 . Any of a number of drivers, such as motors, turbines, generators, and the like, may be employed. However, the HPS may comprise other pumps, such as positive displacement pumps, in conjunction with the centrifugal pump, and other drivers for a given application. As is known, centrifugal pumps will include a set of impellers and diffusers designed move fluid through the pump, perhaps toward a second or more stage having a different set of impellers and diffusers, eventually forcing fluid out through a discharge. A single pump housing may house all pump stages.
[0053] As explained in assignee's U.S. Pat. No. 6,425,735, the motor may be fixedly coupled to horizontal skid at a motor mount surface of the horizontal skid. The pump may be coupled to the horizontal skid by a mount assembly, which may include a support (e.g., a fixed support) and clamp assemblies. The pump may be drivingly coupled to the motor through support. Alternatively, the support may be an external conduit assembly configured for attachment to a pump conduit, such as one of two pump conduits extending from the pump. Pumping systems of the invention may displace water, salt water, sewage, chemicals, oil, liquid propane, or other fluids in through one of the pump conduits and out of another pump conduit. In addition, the temperature of the fluids may vary. For example, some applications may involve pumping hot fluids, while others may involve pumping cold fluids. In addition, the temperature may change during the pumping operation, either from the source of the fluid itself, or possibly due to the heat generated by the operation of the pump and/or driver. In addition, temperature may change dramatically due to weather change.
[0054] Electrical submersible pumps (“ESP”), such as pumping systems known under the trade designation Axia™, available from Schlumberger Technology Corporation, may be modified in accordance with the teachings of the invention. Pumps of this type may feature a simplified two-component pump-motor configuration, with pump having one or more stages inside a housing, and a combined motor and protector. The pump may be built with integral intakes and discharge heads. Fewer mechanical connections may contribute to faster installation and higher reliability of this embodiment. The combined motor and protector assembly, known under the trade designation ProMotor™, may be prefilled in a controlled environment, and may include integral instrumentation that measures downhole temperatures and pressures.
[0055] An alternative electrical submersible pump configuration in which apparatus and systems of the invention may be employed include an ESP deployed on cable, an ESP deployed on coiled tubing with power cable strapped to the outside of the coiled tubing (the tubing acts as the producing medium), and more recently a system known under the trade designation REDACoil™ having a power cable deployed internally in coiled tubing. For example, three “on top” motors may drive three pump stages, all pump stages enclosed in a housing. The pump stages may be identical in number of pump stages and performance characteristics, while some pump stages may have different performance characteristics. A separate protector may be provided, as well as an optional pressure/temperature gauge, sub-surface safety valve (SSSV) and a chemical injection mandrel. The technology of bottom intake ESPs (with motor on the top) has been established over a period of years. It is important to securely install pump stages, motors, and protector within coiled tubing, enabling quicker installation and retrieval times plus cable protection and the opportunity to strip in and out of a live well. This may be accomplished using a deployment cable, which may be a cable known under the trade designation REDACoil™, including a power cable and flat pack with instrument wire and one or more, typically three hydraulic control lines, one each for operating the lower connector release, SSSV, and packer setting/chemical injection.
[0056] Apparatus and systems of the invention may include many optional items. One optional feature of apparatus and systems of the invention is one or more sensors located at the protector to detect the presence of hydrocarbons (or other chemicals of interest) in the internal lubricant fluid. The chemical indicator may communicate its signal to the surface over a fiber optic line, wire line, wireless transmission, and the like. When a certain chemical is detected that would present a safety hazard or possibly damage the motor if allowed to reach the motor, the pump may be shut down long before the chemical creates a problem.
[0057] Typical uses of apparatus and systems of the invention will be in downhole and surface fluid transfer applications.
[0058] Although only a few exemplary embodiments of this invention have been described in detail above, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the following claims. In the claims, no clauses are intended to be in the means-plus-function format allowed by 35 U.S.C. §112, paragraph 6 unless “means for” is explicitly recited together with an associated function. “Means for” clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. | 4y
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application Ser. No. 13/832,753, filed Mar. 15, 2013 now U.S. Pat. No. 8,623,133; which is a continuation-in-part of U.S. patent application Ser. No. 13/563,902, filed Aug. 1, 2012 now U.S. Pat. No. 8,419,852; which is a continuation-in-part of U.S. patent application Ser. No. 13/330,763, filed Dec. 20, 2011, now U.S. Pat. No. 8,252,108 which is a continuation-in-part of U.S. patent application Ser. No. 13/168,412, filed Jun. 24, 2011, now U.S. Pat. No. 8,101,017 which is a continuation-in-part of U.S. patent application Ser. No. 12/945,941, filed Nov. 15, 2010, now U.S. Pat. No. 7,967,908.
This application is related to U.S. Pat. No. 7,468,102 titled, “LIGHT-WEIGHT COMPOSITION FOR MASONRY, MORTAR AND STUCCO,” inventor Jorge G. Chiappo.
FIELD OF THE INVENTION
This invention relates to the field of cement and more particularly to a light-weigh composition of pre-mixed cement mix and sand.
BACKGROUND OF THE INVENTION
Mortar and stucco normally consists of the combination of cement and sand in a ratio of approximately three (3) parts sand to one (1) part cement. Directions for specific brands of cement usually call for from 2.25:1 to 3:1 sand to cement ratios. The cement is generally mixed at the job-site in a gasoline or electric powered mortar mixers. Often, the sand is delivered in bulk, while the cement mix is delivered in bags weighing either 78 or 80 pounds. Due to the weight of the bags, they are often delivered on palates and lifted with fork lifts and/or cranes. One bag of cement mix is mixed with approximately three cubic feet of sand. Water is added to achieve a consistency that allows good workability. While the term sand is used throughout this disclosure for ease of discussion, those skilled in the art will recognize that sand may include other heavy aggregates, such as gravel, crushed stone and the like.
Pre-mixed mortar, stucco or masonry mix is a form of concrete that is pre-mixed at the manufacturing site and typically delivered to the job site in packages such as bags. The package (e.g. bag) contains a mixture of sand and concrete and, optionally, other aggregates. Typically, the pre-mixed mortar, stucco or masonry is used by adding water and applying to the job site.
The weight and volume of these bags of pre-mix mortar, stucco or masonry create several problems. During storage, the weight and volume relate to the total storage space required and the cost of transporting within the warehouse. During transportation, the volume and weight affect the total number of bags that fit within a given truck and the fuel consumption required to transport the bags to the construction site. At the construction site, the weight becomes more of an issue since individual bags are often lifted by a worker and many bags are lifted per day, the 78-80 pound bags cause fatigue and are the cause of many stress-related ailments. For home use, smaller bags (e.g. 60 pound bags) are often sold since many homeowners find it difficult to lift 80 pounds.
U.S. Pat. No. 5,718,758 to Breslauer recognizes that mortars of the prior art create problems due to weight, leading to worker injury during carrying of the mortar, etc.
Other cement compositions disclosed in U.S. Pat. No. 6,840,996 to Morioka, et al, U.S. Pat. No. 7,070,647 to Fujimori, et al, and U.S. Pat. No. 7,148,270 to Bowe describe various cement compositions, none of which provide a light-weight ready-mix composition.
U.S. Pat. No. 7,468,102 to Jorge G. Chiappo describes a light-weight cement mix, but not a pre-mixed composition comprising sand.
Existing pre-mixed compositions have a substantial effect on the environment. For example, in Florida alone, around 25 million bags of pre-mix were consumed in 2008, or approximately 1 million tons of material that had to be mined, shipped, hauled and used. By reducing the per-bag weight by 18 percent while producing an equivalent yield 820 million tons of material would be mined, shipped, hauled and used to create the same amount of finished product that previously contributed to 1 million tons of material that had to be mined, shipped, hauled and used. That means, 180M tons less in raw materials mined, significantly less transportation costs, less wear and tear on vehicles, less fossil fuel used in transportation, less structure for storage, reduced personal injury from strain, etc.
What is needed is a light-weight, pre-mixed mortar, stucco or masonry mix ready for adding water at the job site.
SUMMARY OF THE INVENTION
In one embodiment, a pre-mixed mortar, stucco or masonry composition is disclosed including from 70 to 80 percent sand and from 20 to 30 percent of a light-weight cement mix composition that comprises either slag cement, Gypsum or a combination of slag cement and gypsum; Portland cement; clay; and polystyrene.
In another embodiment, a pre-mixed mortar, stucco or masonry composition is disclosed comprising approximately 75 percent sand and approximately 25 percent of a light-weight cement mix composition that includes from 4 to 20 percent ground polystyrene; up to 20 percent perlite and/or mica; 5 to 10 percent clay; up to 20 percent slag cement; and up to 91 percent Portland cement.
In another embodiment, a pre-mixed mortar, stucco or masonry composition is disclosed comprising approximately 75 percent sand and approximately 25 percent of a light-weight cement mix composition that includes from 4 to 20 percent pulverized polystyrene; up to 20 percent mica; 5 to 10 percent clay; up to 20 percent slag cement; and up to 91 percent Portland cement.
The invention can be best understood by those having ordinary skill in the art by reference to the following detailed description.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the presently preferred embodiments of the invention. Although the disclosed pre-mixed mortar, stucco or masonry mixture is ideal for use in masonry, mortar and stucco, there is no limitation to the application of the mortar, stucco or masonry mix of the present invention.
Prior to the present invention, pre-mixed mortar, stucco or masonry mix is typically delivered to the job site in bags weighing 78 or 80 pounds. The weight of these bags often causes stress and strain injuries to the workers. Additionally, transporting and storage of these bags utilizes more space and energy than is needed. The pre-mixed cement of the present invention provides the same resulting volume of cement with the strength and consistency of the prior art cement mixtures at a per-bag weight of approximately 65 pounds, saving energy and storage space and reducing worker stress and strain. Although 65 pound bags are used as an example, it is known and anticipated to produce the claimed product in any size bag or container including an 80 pound bag that will produce a greater resulting volume than an 80 pound bag of the prior art cement mixtures.
The mortar, stucco or masonry mix of the present invention is mixed with water as the prior mortar, stucco or masonry mixes. Mixing a 65 pound container of the pre-mixed cement mix of the present invention with water, results in a volume is similar to that of an 80 pound container of a pre-mixed cement mix of the prior art. Therefore, a 65 pound bag of the mortar, stucco or masonry mix of the present invention produces a similar amount (volume) of mortar, stucco or masonry when mixed with water as did an 80 pound bag of the prior art.
In some embodiments, the pre-mixed mortar, stucco or masonry mix of the present invention consists of approximately 75% sand and a light-weight cement mix composition of from 35% to 90% cement by weight (either slag cement, Portland cement or hydraulic cement), from 2% to 10% fly ash or hydrous magnesium sulfate by weight, from 1% to 3% sodium tall oil (e.g., a wood pulp by-product) by weight, from 1% to 2% sodium stearate by weight, from 1% to 2% sodium C 14-16 Alpha Olefin by weight, from 1% to 3% linear alkyl benzene by weight and from 10% to 20% silicon dioxide SiO 2 (also known as silica or silox) or fly ash by weight. Silicon dioxide SiO 2 is often derived from fly ash which is a byproduct of coal combustion. Fly ash also consists of aluminum oxide (Al 2 O 3 ) and iron oxide (Fe 2 O 3 ).
In some embodiments, the pre-mixed mortar, stucco or masonry mix of the present invention consists of approximately 75% sand and a light-weight cement mix composition of from 35% to 90% of either slag cement, Portland Cement and/or Gypsum, from 2% to 10% ground granulated blast furnace slag (GGBFS) by weight, from 1% to 3% sodium tall oil (e.g., a wood pulp by-product) by weight, from 1% to 2% sodium stearate by weight, from 1% to 2% sodium C 14-16 Alpha Olefin by weight, from 1% to 3% linear alkyl benzene by weight and from 10% to 20% silicon dioxide SiO 2 (also known as silica or silox) by weight. Silicon dioxide SiO 2 is often derived from fly ash which is a byproduct of coal combustion. Fly ash also consists of aluminum oxide (Al 2 O 3 ) and iron oxide (Fe 2 O 3 ).
In some embodiments, the pre-mixed mortar, stucco or masonry mix of the present invention consists of approximately 75% sand and a light-weight cement mix composition of from 60% to 91% of Portland Cement by weight, from zero to 20% Slag Cement by weight, from 4% to 20% ground plastic, preferably polystyrene by weight, from 0% to 20% Perlite or Mica by weight, and from 5% to 10% clay by weight.
Although any type of clay is anticipated, a silicate material known as Kaolin is preferred, for example, AS 2 H 2 .
Although any type of plastic is anticipated, including, but not limited to, polystyrene, ABS, acrylic, fiberglass, latex powder, and vinyl acetate; polystyrene is preferred.
Although any form of polystyrene is anticipated, it is preferred that the polystyrene be in the form of a fine powder, between 75 to 375 mesh, preferably between 350 and 375 mesh. One method of producing polystyrene is a fine powder of around 350 to 375 mesh is by dry freezing the polystyrene, and pulverizing and/or grinding the polystyrene to an approximately 350-375 mesh. In some embodiments, the polystyrene is recycled polystyrene, such as from packing material.
When a 65 pound bag of pre-mixed cement mix of the present invention is mixed with aggregate and water, it produces, for example, a similar amount of product as a 78 or 80 pound bag of pre-mixed cement of the prior art. Therefore, less weight is transported to the job site, less strain is placed upon the workers, yet the same amount of resulting mix is derived. Equivalent and proportional results are achieved with smaller or larger sized bags or containers.
Equivalent elements can be substituted for the ones set forth above such that they perform in substantially the same manner in substantially the same way for achieving substantially the same result.
It is believed that the system and method of the present invention and many of its attendant advantages will be understood by the foregoing description. It is also believed that it will be apparent that various changes may be made in the form, construction and arrangement of the components thereof without departing from the scope and spirit of the invention or without sacrificing all of its material advantages. The form herein before described being merely exemplary and explanatory embodiment thereof. It is the intention of the following claims to encompass and include such changes. | 4y
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TECHNICAL FIELD
[0001] The present invention relates to a laminate and a production method thereof.
BACKGROUND ART
[0002] Electrochemical cells, such as fuel cells and metal-air batteries, which use gas in an electrode reaction, are provided with a conductive porous layer to improve the battery performance thereof.
[0003] The membrane-electrode assembly (MEA) used as a component of a solid polymer fuel cell has a structure wherein a conductive porous layer, a catalyst layer, an ion-conductive solid polymer electrolyte membrane, a catalyst layer, and a conductive porous layer are sequentially laminated.
[0004] This conductive porous layer is generally formed by using a conductive porous substrate, such as carbon paper or carbon cloth. To enhance the conductivity, gas diffusivity, gas permeability, smoothness, water control properties, such as water drainability and water retainability, etc., of the conductive porous substrate, a conductive layer comprising conductive carbon particles, a water-repellent resin, etc., may be further formed on a conductive porous substrate, which is used as a support.
[0005] Conventional conductive porous layers are formed by applying a conductive layer-forming paste composition to a conductive porous substrate having a surface roughness of about tens of μm, such as carbon paper or carbon cloth, and then drying (for application methods, see Patent Literature (PTL) 1 and 2). Therefore, due to the penetration of the paste composition into the conductive porous substrate surface, etc., it was difficult to form a conductive layer with a uniform thickness. When the film thickness of the conductive layer is not uniform as described above, that is, when there is variation in the film thickness of the conductive layer, stable permeation and diffusion of gas over the adjacent catalyst layer surface is impossible, which lowers fuel cell performance.
[0006] Another method for producing a conductive porous layer comprises forming a conductive layer on a transfer film, then pressure-welding the conductive layer onto the conductive porous substrate and removing the transfer film, by a transfer method. However, compared to the above application methods, this method is insufficient in terms of adhesion between the conductive porous substrate and the conductive layer, leaving room for improvement in battery performance, etc. Further, when the conductive layer is directly laminated on a support, e.g., a separator without using the conductive porous substrate, adhesion between the separator and the conductive layer is insufficient, leaving room for improvement in battery performance, etc.
CITATION LIST
Patent Literature
[0007] PTL 1: JP2006-278037A
[0008] PTL 2: JP2006-339018A
SUMMARY OF INVENTION
Technical Problem
[0009] An object of the present invention is to provide a laminate having good adhesion between a support and a conductive layer.
Solution to Problem
[0010] In view of the above problems, the prevent inventors carried out extensive research to impart excellent adhesion between a support and a conductive layer. As a result, the inventors found that a laminate that can solve the above problems can be provided by using a specific conductive layer. Specifically, we found that a laminate having an improved adhesion between a conductive layer and a support can be produced when a polymer contained in the conductive layer having gas diffusivity and gas permeability is present with a higher density at the surface in contact with the support than at the opposite side surface thereof. The present invention was accomplished based on this finding.
[0011] That is, the present invention relates to the laminate and production method thereof shown in Items 1 to 8 below.
[0012] Item 1. A laminate comprising a conductive layer A formed on a support,
[0013] the conductive layer A containing a conductive carbon material and a polymer,
[0014] the polymer in the conductive layer A being dense at the surface in contact with the support.
[0015] Item 1-1. The laminate according to Item 1, wherein the conductive layer A has gas diffusivity and/or gas permeability.
[0016] Item 1-2. The laminate according to Item 1 or 1-1, wherein the polymer in the conductive layer A is present with a higher density at the surface in contact with the support than at the opposite side surface thereof.
[0017] Item 1-3. The laminate according to any one of Items 1 to 1-2, wherein the conductive layer A satisfies at least one of the following conditions:
[0000] (1) the surface in contact with the support has a fluorine atom content 1 atm % or more larger than at the opposite side surface thereof,
(2) the surface in contact with the support has an oxygen atom content 1 atm % or more larger than at the opposite side surface thereof, and
(3) the surface in contact with the support has a nitrogen atom content 1 atm % or more larger than at the opposite side surface thereof.
[0018] Item 2. A laminate comprising a conductive layer B formed on the surface of the conductive layer A opposite to the surface of the support side of the conductive layer A in the laminate according to Item 1, the conductive layer B containing a conductive carbon material and a polymer.
[0019] Item 2-1. The laminate according to Item 2, wherein the conductive layer B has gas diffusivity and/or gas permeability.
[0020] Item 3. The laminate according to any one of Items 1 to 2-1, wherein the support is a separator or a conductive porous substrate.
[0021] Item 4. The laminate according to any one of Items 1 to 3, wherein the separator comprises at least one member selected from the group consisting of metals such as stainless steel, copper, titanium, aluminum, rhodium, tantalum, and tungsten, or alloys including at least one member of the metals; graphite; and carbon compounds in which carbon is added into resin, and
[0022] the conductive porous substrate is carbon paper, carbon cloth, or carbon felt.
[0023] Item 5. The laminate according to any one of Items 2 to 4 satisfying one of the following conditions (A) and (B):
[0000] (A) the polymer in the conductive layer B is present with a higher density at the surface not in contact with the conductive layer A than at the surface in contact with the conductive layer A, and
(B) the polymer in the conductive layer B is present with a higher density at the surface in contact with the conductive layer A than at the surface not in contact with the conductive layer A.
[0024] Item 5-1. A method for producing a laminate comprising a conductive layer A formed on a support, comprising a step of producing the conductive layer A using a conductive layer A-forming paste composition containing a conductive carbon material and a polymer,
[0025] the polymer in the conductive layer A being dense at the surface in contact with the support.
[0026] Item 6. A method for producing a laminate comprising a conductive layer A having gas diffusivity and/or gas permeability formed on a support, the method comprising the steps of:
[0000] (I) applying a conductive layer A-forming paste composition containing a conductive carbon material and a polymer to a substrate, and drying the composition to produce the conductive layer A having a polymer with a higher density at the surface of the substrate side than at the surface not in contact with the substrate, and
(II) detaching the conductive layer A produced in (I) above from the substrate, disposing the conductive layer A on the support in a manner such that the polymer contained in the conductive layer A is present with a higher density at the surface in contact with the support than at the opposite side surface thereof, and bonding the conductive layer A and the support.
[0027] Item 7. A method for producing a laminate comprising a support, a conductive layer A having gas diffusivity and/or gas permeability, and a conductive layer B having gas diffusivity and/or gas permeability, the conductive layer A being formed on the support, and the conductive layer B being formed on the conductive layer A,
[0028] the method comprising the steps of:
[0000] (I) applying a conductive layer A-forming paste composition containing a conductive carbon material and a polymer to a substrate, and drying the composition to produce the conductive layer A having a polymer with a higher density at the surface of the substrate side than at the surface not in contact with the substrate,
(I′) applying a conductive layer B-forming paste composition containing a conductive carbon material and a polymer to a substrate, and drying the composition to produce the conductive layer B,
(II′) detaching the conductive layer A produced in (I) above from the substrate, and disposing the conductive layer A on the support in a manner such that the polymer contained in the conductive layer A is present with a higher density at the surface in contact with the support than at the opposite side surface thereof,
(III) detaching the conductive layer B produced in (I′) above from the substrate, and disposing the conductive layer B on the conductive layer A, and
(IV) bonding the support, conductive layer A, and conductive layer B.
[0029] Item 8. A membrane-electrode assembly for batteries comprising a catalyst layer laminated membrane and at least one laminate according to any one of Items 1 to 1-2,
[0030] the catalyst layer laminated membrane comprising a catalyst layer, an electrolyte membrane, and a catalyst layer that are sequentially laminated,
[0031] the laminate being disposed on one side or both sides of the catalyst layer laminated membrane,
[0032] the laminate being stacked on the catalyst layer laminated membrane in a manner such that the conductive layer A is in contact with the catalyst layer.
[0033] Item 9. A membrane-electrode assembly for batteries comprising a catalyst layer laminated membrane and at least one laminate according to any one of Items 2 to 5,
[0034] the catalyst layer laminated membrane comprising a catalyst layer, an electrolyte membrane, and a catalyst layer that are sequentially laminated,
[0035] the laminate being disposed on one side or both sides of the catalyst layer laminated membrane,
[0036] the laminate being stacked on the catalyst layer laminated membrane in a manner such that the conductive layer B is in contact with the catalyst layer.
[0037] Item 10. A cell comprising the membrane-electrode assembly for batteries according to Item 8 or 9.
1. Laminate
[0038] The laminate of the present invention comprises a conductive layer A formed on a support. The conductive layer A contains a conductive carbon material and a polymer.
[0039] The present invention has a feature in that the polymer in the conductive layer A is present with a higher density at the surface in contact with the support than at the opposite side surface thereof. Since the polymer in the conductive layer A is present with a higher density at the surface in contact with the support than at the opposite side surface thereof, adhesion between the support and the conductive layer is remarkably improved. When the polymer is present with high density at both surfaces of the conductive layer A, i.e., at the surface in contact with the support and the opposite side surface thereof, and the densities are the same, adhesion between the support and the conductive layer can be improved; however, gas diffusivity and electrical resistance are reduced. Accordingly, in one example of the present invention, when the polymer, which is present with a higher density at one surface of the conductive layer A than at the opposite side surface thereof, includes a fluorine atom, the fluorine atom content at the surface in contact with the support is preferably 1 atm % or more, and more preferably 2 atm % or more larger than the fluorine atom content at the opposite side surface thereof. The upper limit of the difference in fluorine atom content is not particularly limited, but is typically about 20 atm %. The fluorine atom content in the surface of the conductive layer A is measured using energy-dispersive X-ray fluorescence spectrometry.
<Conductive Layer A>
[0040] The conductive layer A contains a conductive carbon material and a polymer. Although the thickness of the conductive layer A is not limited, the preferable thickness is typically about 1 μm to 300 μm, and particularly preferably about 50 μm to 250 μm. In the present invention, use of the conductive layer A can form a laminate having more excellent gas permeability and gas diffusivity.
1. Conductive Carbon Material
[0041] Examples of conductive carbon materials include, but are not limited to, conductive carbon particles, conductive carbon fibers, and the like.
[Conductive Carbon Particles]
[0042] Any carbon material that is conductive may be used as conductive carbon particles, and known or commercially available materials can be used. Examples of such conductive carbon particles include carbon blacks, such as channel black, furnace black, ketjen black, acetylene black, and lamp black; graphite; active charcoal; and the like. Such conductive carbon particles can be used singly, or in a combination of two or more. The incorporation of such conductive carbon particles can enhance the conductivity of the laminate.
[0043] The average particle diameter (arithmetic average particle diameter) of the conductive carbon particles is not limited, and is typically 5 nm to 100 μm. To increase the relatively pore volume and impart gas permeability, smoothness, and water control properties such as water drainability and retainability to the conductive layer A, the preferable average particle diameter is typically about 5 nm to 200 nm, and particularly preferably about 5 nm to 100 nm. To impart gas diffusivity to the conductive layer A, the preferable average is about 5 μm to 100 μm, and particularly preferably about 6 μm to 80 μm.
[0044] When a carbon black is used as conductive carbon particles, the average particle diameter (arithmetic average particle diameter) of the carbon black is not limited. The preferable average particle diameter thereof is typically about 5 nm to 200 nm, and particularly preferably about 5 nm to 100 nm. When a carbon black aggregate is used, the preferable average particle diameter thereof is about 10 to 600 nm, and particularly preferably about 50 to 500 nm. When graphite, active charcoal, or the like is used, the preferable average particle diameter thereof is about 500 nm to 100 μm, and particularly preferably about 1 μm to 80 μm. The average particle diameter of the conductive carbon particles is measured by an LA-920 particle size distribution analyzer, produced by Horiba, Ltd.
[Conductive Carbon Fibers]
[0045] Incorporation of conductive carbon fibers can improve the quality of the surface coated with the conductive layer A-forming paste composition, and can also provide a sheet-like conductive layer A with high strength. Examples of conductive carbon fibers that can be used in the conductive layer A include, but are not limited to, vapor-grown carbon fibers (VGCF (registered trademark)), carbon nanotubes, carbon nanocaps, carbon nanowalls, and the like. Other than the above, as conductive carbon fibers having a relatively large average fiber diameter, PAN (polyacrylonitrile)-based carbon fibers, pitch-based carbon fibers, and the like can be used.
[0046] The average fiber diameter of the conductive carbon fibers is not particularly limited, and is about 50 nm to 20 μm. To increase the relatively pore volume and impart gas permeability, smoothness, and water control properties, such as water drainability and retainability, to the conductive layer A, the preferable average particle diameter is about 50 to 450 nm, and particularly preferably about 100 to 250 nm. The fiber length in this case is not limited, and the preferable average is about 4 to 500 μm, particularly preferably about 4 to 300 μm, more preferably about 4 to 50 μm, and even more preferably about 10 to 20 μm. The preferable average of the aspect ratio is about 5 to 600, and particularly preferably 10 to 500. The fiber diameter, fiber length, and aspect ratio of the conductive carbon fibers are measured from images measured under a scanning electron microscope (SEM), etc.
[0047] When the function of gas diffusivity is imparted to the conductive layer A by providing a relatively large pore diameter, the preferable average fiber diameter of conductive carbon fibers is about 5 μm to 20 μm, and particularly preferably about 6 μm to 15 μm. The fiber length in this case is not limited, and the preferable average is 5 μm to 1 mm, and particularly preferably about 10 μm to 600 μm. The preferable average of the aspect ratio is about 1 to 50, and particularly preferably about 2 to 40. In this case as well, the fiber diameter, fiber length, and aspect ratio of the conductive carbon fibers are measured from images measured under a scanning electron microscope (SEM), etc.
Polymer
[0048] The polymer is not particularly limited, and known or commercially available materials can be used. The polymer preferably has a Tg of about −100 to 300° C., more preferably −60 to 250° C., even more preferably about −30 to 220° C., and particularly preferably about −20 to 210° C. Specific examples of the polymer include ion-conductive polymer resins (e.g., Nafion), vinyl acetate resins, styrene-acrylic copolymer resins, styrene-vinyl acetate copolymer resins, ethylene-vinyl acetate copolymer resins, polyester-acrylic copolymer resins, urethane resins, acrylic resins, phenolic resins, polyvinylidene fluoride (PVDF), and the like. Other examples thereof include hexafluoropropylene-vinylidene fluoride copolymers; trifluorochloroethylene-vinylidene fluoride copolymers, and like fluororubbers; silicone rubbers; and the like. Such polymers may be used singly, or in a combination of two or more.
[0049] The use of an elastomer, such as fluororubber, as a polymer can increase the flexibility of the conductive layer A, and can also further increase its adhesion to other layers due to the low Tg of the elastomer. In this specification, the term “fluororubber” refers to a material having a Tg of about −30 to 100° C.
[0050] As the elastomer, an elastomer emulsion (a suspension in which elastomer particles are dispersed) may be used, or an elastomer dissolved in a solvent may be used. In the case of using an elastomer emulsion, it is preferable to prepare an emulsion by dispersing an elastomer in a solvent, or by using a commercially available product. Examples of the solvent include water, ethanol, propanol, and the like. Examples of the solvent used when an elastomer dissolved in a solvent is used include N-methylpyrrolidone (NMP), methyl ethyl ketone (MEK), toluene, vinyl acetate, dimethylacetamide (DMA), isopropyl alcohol (IPA), and the like.
[0051] To impart water repellency to the conductive layer A, a water-repellent resin, such as a fluororesin, may be used. In particular, when a polymer with poor water repellency is used as the polymer, the use of a water-repellent resin is effective for increasing water repellency. Examples of such fluororesins include polytetrafluoroethylene resin (PTFE), fluorinated ethylene propylene resin (FEP), perfluoroalkoxy resin (PFA), and the like.
[0052] In the present invention, the conductive layer A-forming paste composition may comprise a dispersant, alcohol, etc., in addition to the above conductive carbon material and polymer, as long as the effect of the present invention is not impaired.
Dispersant
[0053] The dispersant may be any dispersant that can disperse conductive carbon particles, a polymer, etc., in water. Known or commercially available dispersants can be used. Examples of such dispersants include nonionic dispersants, such as polyoxyethylene distyrenated phenyl ether, polyoxyethylene alkylene alkyl ether, and polyethylene glycol alkyl ether; cationic dispersants, such as alkyltrimethylammonium salts, dialkyl dimethyl ammonium chlorides, and alkylpyridinium chlorides; and anionic dispersants, such as polyoxyethylene fatty acid esters and acidic group-containing structure-modified polyacrylate. Such dispersants may be used singly, or in a combination of two or more.
Alcohol
[0054] The alcohol is not particularly limited, and known or commercially available alcohols can be used. Examples of such alcohols include monohydric or polyhydric alcohols having about 1 to 5 carbon atoms. Specific examples thereof include methanol, ethanol, 1-propanol, isopropanol, 1-butanol, 1-pentanol, and the like.
Support
[0055] The support is not particularly limited as long as it has a function of supporting the conductive layer. Examples of the support include a separator, a conductive porous substrate, and the like.
<Separator>
[0056] A known or commercially available separator can be used as a separator.
[0057] The material of the separator is not particularly limited, and can be suitably selected according to its purpose. Examples include metals, such as stainless steel, copper, titanium, aluminum, rhodium, tantalum, and tungsten, or alloys including at least one of these metals; graphite; carbon compounds in which carbon is added into resin; and the like. Of these, from the viewpoint of strength, reduction in fuel cell thickness, conductivity, etc., the metals or alloys containing at least one of the metals are preferable, and titanium and stainless steel are more preferable.
[0058] To improve corrosion resistance and conductivity, plate processing can be performed on the surface of the separator. The material of the plate is not particularly limited, and examples include metals, such as platinum, ruthenium, rhodium, tungsten, tantalum, and gold, or alloys thereof; carbon; composites of carbon and corrosion-resistant resins, e.g., epoxy resins and acrylic resins; and the like. Of these, gold is preferable in view of high water repellency.
[0059] The separator includes a gas flow channel. The width, depth, shape, etc., of the gas flow channel are not particularly limited, and can be suitably selected according to its purpose as long as the gas flow channel flows hydrogen, air, etc., which are the fuels of a fuel cell, and discharges water generated by the reaction of the fuel cell to the exterior of the cell. The width is typically 0.1 mm to 2 mm (preferably 0.5 mm to 1.5 mm), and the depth is typically 0.05 mm to 2 mm (preferably 0.1 mm to 1 mm).
[0060] The gas flow channel may have an uneven surface or a flat surface. The gas flow channel preferably has an uneven surface from the viewpoint of improvement in water repellency. When the gas flow channel has an uneven surface, the surface roughness is preferably 5 nm to 200 nm, and more preferably 5 nm to 100 nm. The surface roughness in the present invention is the value measured according to JIS B 0601.
[0061] The separator preferably includes a water-repellent layer partially or wholly formed on the gas flow channel, and the water-repellent layer includes at least one member selected from sulfur and sulfur compounds.
[0062] In the separator, a phosphorous-containing layer is formed on at least a side of, preferably both sides of, and more preferably the entire surface of a metal plate constituting the separator. The phosphorous-containing layer protects the surface of the metal plate from the superacid-related corrosion of the solid polymer electrolyte.
[0063] The material constituting the phosphorous-containing layer varies depending on the types of metal plates, and the types of phosphorous compounds used for forming the phosphorous-containing layer.
[0064] Examples of the phosphorus compound used in the formation of the phosphorous-containing layer include known inorganic phosphorus compounds, such as condensed phosphoric acids, e.g., phosphoric acid and polyphosphoric acid, and the salts thereof. Examples of the salts include ammonium salts, alkali metal salts, such as sodium salts and potassium salts, and metal salts.
<Conductive Porous Substrate>
[0065] The conductive porous substrate can be used as a gas diffusion layer when used for fuel cells.
[0066] A known or commercially available gas diffusion layer can be used as the gas diffusion layer. Specifically, a conductive porous substrate can be used as a gas diffusion layer. The conductive porous substrate is not particularly limited as long as it has conductivity and porosity. Examples of the conductive porous substrate include carbon paper, carbon cloth, carbon felt, and the like.
[0067] For exemplary purposes with respect to the properties of typical carbon paper, the properties of TGP-H-060 produced by Toray Industries are shown below:
Thickness: 190 μm;
[0068] Electrical resistance: 80 mΩ·cm in the thickness direction, 5.8 mΩ·cm in the surface direction;
Porosity: 78%;
[0069] Bulk density: 0.44 g/cm 3 ;
Surface roughness: 8 μm.
The thickness of the carbon paper, etc., is not limited.
Preferably, the thickness is typically about 50 to 1,000 μm, and more preferably about 100 to 400 μm.
[0070] To suitably diffuse an oxidizing agent gas in a catalyst layer mentioned later, the conductive porous substrate may be a porous metallic body formed of a metal mesh, a metal foaming body, and the like. Use of the porous metal body further improves conductivity. Examples of metals used for the porous metal body include poor metals, such as nickel and palladium; silver; stainless steel; and the like. To improve corrosion resistance and conductivity, plate processing may be performed on the metal mesh and metal foaming body surface. The material of the plating is not restricted, but examples include metals, such as platinum, ruthenium, rhodium, tungsten, tantalum, and gold, or alloys thereof; carbon; composites of carbon and corrosion-resistant resins, such as epoxy resins and acrylic resins. Of these, gold is preferable from the viewpoint of high water repellency.
[0071] A conductive porous substrate previously subjected to a water-repellent treatment is preferably used. This can further enhance the water repellency of the conductive porous substrate.
[0072] The water-repellent treatment may be, for example, a method comprising immersing the conductive porous substrate in an aqueous dispersion of a fluororesin, etc. The fluororesin may be the aforementioned resin, or the like. In this method, a dispersant as mentioned above may be used to disperse a fluororesin in water, and an aqueous suspension containing a fluororesin and an aqueous dispersant is preferably used as the aqueous dispersion.
[0073] The amount of the fluororesin in the aqueous dispersion is not particularly limited and may be, for example, about 1 to 30 parts by weight, and preferably about 2 to 20 parts by weight, per 100 parts by weight of water.
<Conductive Layer B>
[0074] In the laminate of the present invention, the conductive layer B is preferably formed on the surface of the conductive layer A (i.e., on the surface opposite to the support side surface of the conductive layer A).
[0075] The conductive layer B contains a conductive carbon material and a polymer. Although the thickness of the conductive layer B is not limited, the preferable thickness is typically about 1 μm to 150 μm, and particularly preferably about 5 μm to 100 μm. In the present invention, by forming the conductive layer B on the surface opposite to the support side surface of the conductive layer A, a laminate having improved gas permeability, smoothness, water control properties, etc. can be formed.
Conductive Carbon Material
[0076] Examples of conductive carbon materials include, but are not limited to, conductive carbon particles, conductive carbon fibers, and the like. The materials listed in the conductive layer A section can be used as conductive carbon particles and conductive carbon fibers.
Polymer
[0077] The materials used in the conductive layer A section can be used as polymers. That is, the polymer preferably has a Tg of about −100 to 300 C.°, more preferably −60 to 250 C.°, even more preferably about −30 to 220 C.°, and particularly preferably about −20 to 210 C.°. Specific examples of the polymer include ion-conductive polymer resins (e.g., Nafion), vinyl acetate resins, styrene-acrylic copolymer resins, styrene-vinyl acetate copolymer resins, ethylene-vinyl acetate copolymer resins, polyester-acrylic copolymer resins, urethane resins, acrylic resins, phenolic resins, polyvinylidene fluoride (PVDF), and the like. Other examples thereof include hexafluoropropylene-vinylidene fluoride copolymers; trifluorochloroethylene-vinylidene fluoride copolymers, and like fluororubbers; silicone rubbers; and the like. Such polymers may be used singly, or in a combination of two or more.
[0078] In the present invention, the conductive layer B-forming paste composition may comprise a fluororesin, a dispersant, alcohol, etc., in addition to the above conductive carbon material and polymer, as long as the effect of the present invention is not impaired. Usable fluororesins, dispersants, and alcohols may be the same materials as used in the conductive layer A.
<Characteristics of Conductive Layer A and Conductive Layer B>
[0079] In the present invention, the front and back sides of the conductive layer A have different densities of the polymer component. That is, the conductive layer A has a polymer with a higher density at one side surface than at the opposite side surface thereof. When the conductive layer A contains two or more types of polymers, at least one type of polymer is preferably present with a higher density at one side surface than at the opposite side surface thereof. Specifically, when the polymer that is present with a higher density at one side surface than at the opposite side surface thereof contains a fluorine atom, the one side surface of the conductive layer A preferably has a fluorine atom content 1 atm % or more, more preferably 2 atm % or more larger than at the opposite side surface thereof. The upper limit of the difference in fluorine atom content is not particularly limited, and it is typically about 20 atm %.
[0080] The surface of the conductive layer A having a higher fluorine atom content preferably has a fluorine atom content of 10 to 20 atm %, and more preferably 11 to 18 atm %. When the fluorine atom content is in this range, adhesion with the support can be further improved. The surface of the conductive layer A having a lower fluorine atom content preferably has a fluorine atom content of 1 to 16 atm %, and more preferably 2 to 15 atm %. When the fluorine atom content is in this range, gas diffusivity and battery properties can be improved.
[0081] In the above example, the polymer containing a fluorine atom is used. When a polymer that is present with a higher density at one side surface than at the opposite side surface thereof does not contain a fluorine atom, the density degree can be confirmed by suitably confirming the density of an atom contained in the polymer. Specifically, for a polymer containing an oxygen atom, the density can be confirmed by the oxygen atom content, and for a polymer containing a nitrogen atom, the density can be confirmed by the nitrogen atom content. The preferable density difference, between the front and back surfaces, or the preferable density of the oxygen atom or nitrogen atom is the same as that of the fluorine atom. Similar to the fluorine atom content, the oxygen atom content and nitrogen atom content in the surface of the conductive layer A are measured using energy-dispersive X-ray fluorescence spectrometry, etc.
[0082] In the present invention, the front and back sides of the conductive layer B may have different densities of the polymer component, or the polymer component may be uniformly present in the conductive layer B. That is, in the conductive layer B, the polymer is present with a higher density at one side surface than at the opposite side surface thereof, or the polymer component may be uniformly present in the conductive layer B.
[0083] In the present invention, to further improve gas diffusivity and battery properties, the front and back sides of the conductive layer B desirably have different densities of the polymer component. Specifically, in the conductive layer B, the polymer is preferably present with a higher density at one side surface than at the opposite side surface thereof. More specifically, when the polymer that is present with a higher density at one side surface than at the opposite side surface thereof contains a fluorine atom, the side surface of the conductive layer B preferably has a fluorine atom content 1 atm % or more, more preferably 2 atm % or more larger than at the opposite side surface thereof. The upper limit of the difference in fluorine atom content is not particularly limited, and is typically about 20 atm %.
[0084] The surface of the conductive layer B having a higher fluorine atom content preferably has a fluorine atom content of 10 to 20 atm %, and more preferably 11 to 18 atm %. When the fluorine atom content is in this range, adhesion with the support can be further improved. The surface of the conductive layer B having a lower fluorine atom content preferably has a fluorine atom content of 1 to 16 atm %, and more preferably 2 to 15 atm %. With the fluorine atom content is in this range, gas diffusivity and battery properties can be improved.
[0085] As in the conductive layer A, in the above example, the polymer containing a fluorine atom is used. When a polymer that is present with a higher density at one side surface than at the opposite side surface thereof does not contain a fluorine atom, the density degree can be confirmed by suitably confirming the density of an atom contained in the polymer. Specifically, for a polymer containing an oxygen atom, the density can be confirmed by the oxygen atom content, and for a polymer containing a nitrogen atom, the density can be confirmed by the nitrogen atom content. The preferable density difference, between the front and back surfaces, or the preferable density of the oxygen atom or nitrogen atom is the same as that of the fluorine atom.
[0086] In the present invention, when the conductive layer B contains two or more types of polymers, at least one type of polymer is preferably present with a higher density at one side surface than at the opposite side surface thereof. The surface at which the polymer is present with a higher density in the conductive layer B has excellent adhesion, thus improving adhesion with another material.
[0087] Specifically, the present invention desirably satisfies either of the following conditions (A) and (B):
[0000] (A) The polymer in the conductive layer B is present with a higher density at the surface not in contact with the conductive layer A than at the surface in contact with the conductive layer A, and
(B) The polymer in the conductive layer B is present with a higher density at the surface in contact with the conductive layer A than at the surface not in contact with the conductive layer A.
[0088] The distribution states of the polymer component in the conductive layer A and conductive layer B are confirmed by analyzing both surfaces of each layer using energy-dispersive X-ray fluorescence spectrometry, etc. The distribution of the polymer component can also be analyzed by energy-dispersive X-ray fluorescence analysis in the layer's cross-sectional direction. When the element specific to the polymer cannot be detected by energy-dispersive X-ray fluorescence analysis, for example, in the case of using a styrene-acrylic acid rubber, the functional group resulting from the polymer is observed by a Fourier transform infrared spectrophotometer, etc.
[0089] In the present invention, the pore diameter distribution of each of the conductive layer A and the conductive layer B is preferably within the range of 10 nm to 10 μm. To impart gas permeability, smoothness, and water control properties, such as water drainability and water retainability to the conductive layers, the pore diameter distribution is preferably such that the volume of pores having a diameter of 10 nm to 5 μm accounts for at least 50% of the total pore volume. The above-mentioned pore diameter distribution can be achieved by using, for example, conductive carbon fibers with an average fiber diameter of about 50 to 450 nm, a polymer, conductive carbon particles with an average particle diameter (arithmetic average particle diameter) of 5 to 200 nm, and conductive carbon particles (e.g., graphite, active charcoal, etc.) with an average particle diameter of 500 nm to 40 μm.
[0090] To impart gas diffusivity to the conductive layers, the pore diameter distribution is preferably such that the volume of pores having a diameter of 5 to 100 μm accounts for at least 50% of the total pore volume. The above pore diameter distribution can be achieved, for example, by using conductive carbon fibers with an average fiber diameter of 5 μm or more, conductive carbon particles with an average particle diameter of 5 μm or more, a polymer, etc.
[0091] The pore diameter distribution can be measured, for example, by an AutoPore IV 9500 automatic porosimeter (produced by Shimadzu Corporation).
<Method for Producing the Conductive Layer A and the Conductive Layer B>
[0092] The conductive layer A of the present invention can be obtained, for example, by applying the conductive layer A-forming paste composition containing a conductive carbon material and a polymer to a substrate, and drying the composition; and then detaching the substrate.
[0093] The conductive layer B can also be obtained by applying the conductive layer B-forming paste composition containing a conductive carbon material and a polymer to a substrate, and drying the composition; and then detaching the substrate.
[0094] According to the production method above, the proportion of the polymer component that is present at the surfaces of the conductive layer A and conductive layer B can be adjusted by utilizing the phenomenon, occurring during the drying of the paste composition, in which the polymer component contained in the conductive layer A-forming paste composition or in the conductive layer B-forming paste composition segregates from the side not in contact with the substrate toward the side in contact with the substrate. Accordingly, the density of the polymer component at one side surface can be increased by adjusting the amount of polymer used, viscosity of the paste composition, particle diameter in the case of using an elastomer emulsion as a polymer, drying time, specific gravity of the conductive carbon material (e.g., conductive carbon particles, conductive carbon fibers, etc.), functional group present at the surface of the conductive carbon material (e.g., conductive carbon particles, conductive carbon fibers, etc.), and the like. In particular, as the viscosity of the paste composition lowers and the drying time lengthens, the resin tends to segregate.
Content
[0095] The conductive layer A-forming paste composition may contain, for example, about 5 to 200 parts by weight (particularly, 40 to 150 parts by weight) of the polymer, about 0 to 100 parts by weight (particularly, 5 to 50 parts by weight) of the dispersant, about 0 to 1,100 parts by weight (particularly, 100 to 1,000 parts by weight) of the solvent, such as alcohol, based on 100 parts by weight of the conductive carbon particles (the total amount of conductive carbon particles and conductive carbon fibers, when conductive carbon fibers are contained). When the conductive carbon fibers are contained, the preferable ratio of conductive carbon particles to conductive carbon fibers is in the range of about 9:1 to 1:9 (weight ratio), and particularly preferably about 8:2 to 2:8 (weight ratio). To enhance water repellency, the composition may contain a fluororesin as a polymer in an amount of about 5 to 250 parts by weight (particularly, 10 to 200 parts by weight). When an elastomer emulsion is used as a polymer, the solids content is preferably within the above-mentioned range.
[0096] The formulation of the conductive layer B-forming paste composition may be the same as that of the conductive layer A-forming paste composition.
[0097] The substrate is not particularly limited insofar as the paste composition can be applied thereto. Known or commercially available substrates can be used widely. Examples of substrates include polyimide, polyethylene terephthalate, polyparabanic acid aramid, polyamide (nylon), polysulfone, polyether sulphone, polyphenylene sulfide, polyether ether ketone, polyether imide, polyarylate, polyethylene naphthalate, polypropylene, and like polymeric films. Further, ethylene-tetrafluoroethylene copolymers (ETFE), tetrafluoroethylene-hexafluoropropylene copolymers (FEP), tetrafluoro-fluoro alkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), or the like can also be used. Among these, polymeric films that are highly heat-resistant and easily available are preferable. For example, polyethylene terephthalate, polyethylene naphthalate, polytetrafluoroethylene (PTFE), polyimide, and like films are preferable.
[0098] The substrate preferably has a release layer formed thereon. For example, the release layer may comprise a known wax. As a substrate having a release layer formed thereon, a film coated with SiOx, a fluororesin, or the like may be used.
[0099] It is preferable from the viewpoint of ease of handling and cost efficiency that the thickness of the substrate is typically about 6 to 100 μm, and particularly preferably about 10 to 60 μm.
[0100] The application method of each paste composition is preferably application using known or commercially available doctor blades and like blades; wire bars; squeegees, and like instruments; applicators; die coaters; etc.
[0101] The amount of each paste composition to be applied is not particularly limited. For example, to impart gas permeability, smoothness, and water control properties, such as water drainability and water retainability to the conductive layers, the paste composition is preferably applied in such an amount that the conductive layer after drying has a thickness of about 1 to 150 μm, and preferably about 5 to 100 μm. To impart gas diffusivity to the conductive layers, the paste composition is preferably applied in such an amount that the conductive layer after drying has a thickness of about 1 to 300 μm, and preferably about 50 to 250 μm.
[0102] The drying conditions are also not limited. The drying conditions can be suitably changed according to the conditions, such as the volatilization temperature of the solvent used (e.g., alcohol) (for example, about 150° C.), and the glass transition temperature of the polymer.
[0103] After the conductive layer A and conductive layer B are obtained by drying, the conductive layers may be further subjected to drying at a higher temperature (e.g., about 150 to 500° C.), if necessary.
[0104] Further, the conductive layer A and conductive layer B may be treated on the surface (in particular, on the surface in contact with another layer). Examples of the surface treatment include mechanical treatment to physically roughen the surface by a metallic brush, sandblasting, or the like, matting treatment, corona discharge treatment, plasma discharge treatment, ultraviolet treatment, flame treatment, etc.
[0105] For example, in the corona treatment, the inter electrode distance is 0.3 to 5 mm, the discharge energy is 0.5 to 5 kW, a silicone rubber covering electrode is used as an electrode, and a sample is irradiated at the rate of 0.1 to 50 m/min.
<Method for Producing Laminate>
[0106] The laminate of the present invention can be produced by laminating and bonding the support and the conductive layer A.
[0107] For example, the laminate of the present invention is produced by the following steps:
[0000] (I) Forming a conductive layer A using a conductive layer A-forming paste composition containing a conductive carbon material and a polymer, and
(II) Disposing the conductive layer A on the support in a manner such that the polymer contained in the conductive layer A produced in (I) above is present with a higher density at the surface that is in contact with the support, and bonding the support and the conductive layer A.
[0108] Before or after step (II), the step of producing a conductive layer B, and the step of laminating the conductive layer B on the conductive layer A may be added. The conductive layer B can be obtained, for example, by previously applying a conductive layer B-forming paste composition containing a conductive carbon material and a polymer on the substrate, and drying the composition; and then detaching the conductive layer B from the substrate. In this case, the bonding of the conductive layer B and the conductive layer A may be performed separately from, or at the same time as the step of bonding the support and the conductive layer A performed in step (II).
[0109] An example of the method for producing the laminate of the present invention is as follows.
[0110] The method for producing the laminate of the present invention comprises the steps of:
[0000] (I) Applying a conductive layer A-forming paste composition containing a conductive carbon material and a polymer to a substrate, and drying the composition, and then detaching the conductive layer A from the substrate to produce the conductive layer A; and
(II) Disposing the conductive layer A on a support in a manner such that the polymer contained in the conductive layer A produced in (I) above is present with a higher density at the surface that is in contact with the support, and performing hot-pressing for bonding.
[0111] The temperature for hot pressing in step (II) is not particularly limited, and is typically from 25 to 300° C. The pressure for hot pressing in step (II) is not particularly limited, and it is typically from 0.5 to 30 MPa.
[0112] The method for producing the laminate comprising a conductive layer B, for example, includes the steps of:
[0000] (I) Applying a conductive layer A-forming paste composition containing a conductive carbon material and a polymer to a substrate, and drying the composition, and then detaching the conductive layer A from the substrate to produce the conductive layer A;
(I′) Applying a conductive layer B-forming paste composition containing a conductive carbon material and a polymer to a substrate, and drying the composition, and then detaching the conductive layer B from the substrate to produce the conductive layer B; and
(II′) Disposing the conductive layer A on a support in a manner such that the polymer contained in the conductive layer A produced in (I) above is present with a higher density at the surface that is in contact with the support, disposing the conductive layer B produced in (I′) above on the conductive layer A, and performing hot-pressing for bonding.
[0113] In the present invention, the front and back sides of the conductive layer B desirably have different densities of the polymer component. Specifically, the polymer present in one side surface of the conductive layer B is preferably present with a higher density than at the opposite side surface thereof.
[0114] Accordingly, in step (II′) above, the conductive layer B is preferably disposed on the conductive layer A in a manner such that the laminate satisfies either of the following conditions (A) and (B):
[0000] (A) The polymer in the conductive layer B is present with a higher density at the surface not in contact with the conductive layer A than at the surface in contact with the conductive layer A, and
(B) The polymer in the conductive layer B is present with a higher density at the surface in contact with the conductive layer A than at the surface not in contact with the conductive layer A.
[0115] The temperature of hot pressing in step (II′) above is not particularly limited, and is typically from 25 to 300° C. The pressure of hot pressing in step (II′) is not particularly limited, and is typically from 0.5 to 30 MPa.
[0116] After the formation of the laminate of the support and conductive layer A, the laminate of the support, conductive layer A and conductive layer B, and the laminate of the conductive layer A and conductive layer B, drying (for example, at about 150 to 500° C.) may be performed at a high temperature as required.
2. Membrane-Electrode Assembly for Batteries
[0117] The laminate (comprising at least a conductive porous substrate and a conductive layer A) of the present invention can also be used to produce a membrane-electrode assembly for batteries. Specifically, the laminate of the present invention is preferably stacked on one side or both sides of the catalyst layer laminated membrane wherein one or two catalyst layers are laminated on one side or both sides of the electrolyte membrane in a manner such that the conductive layer A or conductive layer B and the catalyst layer are face-to-face.
[0118] In the present invention, the membrane-electrode assembly can be produced by stacking and bonding the previously produced laminate of the present invention on one side or both sides of the catalyst layer electrolyte membrane laminate described below. The laminate of the present invention and the membrane-electrode assembly can also be produced at the same time by stacking the laminate of the present invention on one side or both sides of the catalyst layer laminated membrane described below in a manner such that the catalyst layer and the conductive layer A or conductive layer B of the laminate of the present invention are face-to-face.
[0119] Alternatively, the conductive layer B may be stacked on one side or both sides of the catalyst layer laminated membrane described below beforehand, and the laminate of the support and the conductive layer A may be stacked on the conductive layer B in a manner such that the conductive layer B and the conductive layer A are face-to-face, and press bonded to produce the membrane-electrode assembly.
<Catalyst Layer Laminated Membrane>
Electrolyte Membrane
[0120] The electrolyte membrane is not limited as lone as it is a hydrogen ion-conductive electrolyte membrane or a hydroxide ion-conductive electrolyte membrane. Known or commercially available electrolyte membranes, such as hydrogen ion-conductive electrolyte membranes or hydroxide ion-conductive electrolyte membranes, can be used. Examples of hydrogen ion-conductive electrolyte membranes include the “Nafion” (registered trademark) membrane produced by Du Pont, Inc.; the “Flemion” (registered trademark) membrane produced by Asahi Glass Co., Ltd.; the “Aciplex” (registered trademark) membrane produced by Asahi Kasei Corporation; the “GoreSelect” (registered trademark) membrane produced by Gore & Assoc. Inc.; and the like. Examples of hydroxide ion-conductive electrolyte membranes include hydrocarbon-based electrolyte membranes, such as Aciplex (registered trademark) A-201, A-211, A-221, etc., produced by Asahi Kasei Corporation; Neosepta (registered trademark) AM-1 and AHA produced by Tokuyama Corporation; and the like. Examples of fluororesin-based electrolyte membranes include Tosflex (registered trademark) IE-SF34 produced by Tosoh Corporation; Fumapem (registered trademark) FAA produced by FuMA-Tech GmbH; and the like.
[0121] The preferable thickness of the electrolyte membrane is typically about 20 to 250 μm, and particularly preferably about 20 to 150 μm.
[0122] When the membrane-electrode assembly for batteries of the present invention is used for metal-air batteries, a gel or liquid electrolyte can be used in addition to solid electrolyte membranes. In this case, the materials used for the electrolyte are not particularly limited, and known or commercially available materials conventionally used for metal-air batteries can be used. For example, the electrolyte is selected according to the metal at the negative electrode, and water, a salt solution, an alkaline solution, a metal salt solution of the metal at the negative electrode, etc., can be suitably used.
Catalyst Layer
[0123] As the catalyst layer, a known or commercially available platinum-containing catalyst layer (a cathode catalyst or an anode catalyst) can be used. Specifically, the catalyst layer is preferably formed of a dried product of the catalyst layer-forming paste composition, comprising (1) carbon particles supporting catalyst particles and (2) a hydrogen ion-conductive polymer electrolyte (preferably a hydrogen ion-conductive polymer electrolyte).
[0124] Any catalyst particles that can cause an oxidation-reduction reaction (in the case of fuel cells, oxidation of hydrogen at the anode, and reduction of oxygen at the cathode; and in the case of metal-air batteries, reduction of oxygen at the positive electrode) and that have catalytic activity can be used as the catalyst particles. Examples of catalyst particles include platinum, platinum alloys, platinum compounds, and the like. Examples of platinum alloys include alloys of platinum and at least one metal selected from the group consisting of ruthenium, palladium, nickel, molybdenum, iridium, iron, and cobalt.
[0125] Examples of hydrogen ion-conductive polymer electrolytes include perfluorosulfonic acid-based fluorine ion-exchange resins. Specific examples thereof include perfluorocarbon sulfonic acid-based polymers (PFS-based polymers) in which a C—H bond of a hydrocarbon-based ion-exchange membrane is replaced with fluorine.
[0126] The thickness of the catalyst layer is not particularly limited. The thickness thereof is typically about 1 to 100 μm, and preferably about 2 to 50 μm.
[0127] In the catalyst layer, fluororesins and non-polymer-based fluorine materials, such as fluorinated pitch, fluorinated carbon, and graphite fluoride, can be added as a water repellent.
[0128] In metal-air batteries, examples of the catalyst used for the positive electrode include, in addition to the catalysts used for anode and cathode catalysts above, manganese dioxide, gold, active charcoal, iridium oxides, perovskite complex oxides, metal-containing pigments, etc. The catalyst powders thereof can be dispersed using a water repellent as a binder, and applied to form a catalyst layer. Alternatively, a material that can be vapor deposited is vapor deposited to form a catalyst layer. The catalyst layer can be also formed by reducing a metal salt solution on an electrode to deposit metal in a fine shape.
[0129] The metal at the negative electrode is selected depending on the type of the metal-air battery to be formed. Metals, such as lithium (Li), sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), zinc (Zn), aluminum (Al), and iron (Fe), or alloys or metal compounds thereof can be used as a negative-electrode active material. To increase the contact area of the negative electrode and the electrolyte, the negative electrode preferably has pores.
Method for Producing Catalyst Layer Laminated Membrane
[0130] The catalyst layer laminated membrane can be produced, for example, by using a transfer film for catalyst layer formation in which a catalyst layer is formed on one side of a substrate, and disposing the catalyst layer transfer film in a manner such that the catalyst layer and the electrolyte membrane are face-to-face, pressing the layers under heat to transfer the catalyst layer to the electrolyte membrane, and then detaching the transfer film. A catalyst layer laminated membrane comprising a catalyst layer on both sides of the electrolyte membrane can be produced by repeating this operation twice. In consideration of work efficiency, etc., simultaneously laminating the catalyst layer on both sides of the electrolyte membrane is preferable.
[0131] For the transfer, it is preferable to press the layers from the substrate film side of the catalyst layer transfer film using a known pressing machine, etc. To avoid poor transfer, the preferable pressure level is typically about 0.5 to 10 MPa, and particularly preferably about 1 to 8 MPa. To avoid poor transfer, the face to be pressed is preferably heated during the pressing operation. Preferably, the heating temperature is appropriately changed according to the type of electrolyte membrane to be used.
[0132] The substrate film is not particularly limited, and the same substrates as mentioned above can be used. Examples of substrate films include polymeric films such as polyimide, polyethylene terephthalate (PET), polysulfone, polyether sulphone, polyphenylene sulfide, polyether ether ketone, polyether imide, polyarylate, polyethylene naphthalate (PEN), polyethylene, polypropylene, and polyolefin. Heat-resistant fluororesins, such as ethylene-tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and polytetrafluoroethylene (PTFE), can also be used. Among these, inexpensive and easily available polymeric films are preferable; and polyethylene terephthalate, etc., are more preferable.
[0133] In view of the workability, cost efficiency, etc., of forming the catalyst layer on the substrate film, the preferable thickness of the substrate film is typically about 6 to 150 μm, and particularly preferably about 12 to 75 μm.
[0134] The substrate film may have a release layer formed thereon. Examples of release layers include a layer comprising a known wax, a plastic film coated with known SiOx or a fluororesin, and the like. A substrate film comprising a film with high release properties formed thereon, such as a laminate of a PET substrate and a heat-resistant fluororesin substrate; and like structured substrate films, are also usable.
[0135] Other than the transfer method mentioned above, the catalyst layer can be formed on the electrolyte membrane by applying the catalyst layer-forming paste composition on the electrolyte membrane. In this case, known conditions can be used.
3. Battery
[0136] The battery of the present invention (e.g., solid polymer fuel cells, metal-air batteries, etc.) can be produced by the method of combining the catalyst layer laminated membrane with the laminate (laminate of the separator and the conductive layer A) of the present invention, or by providing a known or commercially available separator, terminals, etc., in the above membrane-electrode assembly or on the conductive porous substrate side of the laminate (laminate of the conductive porous substrate and the conductive layer A).
[0137] For example, when the laminate of the present invention is used for metal-air batteries, the conductive porous substrate can be used as the support to assemble the negative electrode/electrolyte/separator for metal-air battery/conductive layer A (conductive layer B)/support. In this case, since the conductive layer A (conductive layer B) includes a conductive carbon material, it functions as the catalyst layer and/or gas diffusion layer. In addition to the above structure, a positive electrode catalyst layer can be laminated on the conductive layer A side. In this case, a conductive porous substrate such as metal mesh can be used as the support.
[0138] When the laminate of the present invention is used for metal-air batteries, the structure of (negative electrode/electrolyte/separator for metal-air battery/positive electrode catalyst layer/(conductive layer B)/conductive layer A/support) is an option. In this case as well, since the conductive layer A (conductive layer B) includes a conductive carbon material, it functions as a catalyst layer and/or a gas diffusion layer. Therefore, the laminate can be used without providing the positive electrode catalyst layer mentioned above.
[0139] The types of metal-air batteries include lithium-air batteries, sodium-air batteries, potassium-air batteries, magnesium-air batteries, calcium-air batteries, zinc-air batteries, aluminum-air batteries, and iron-air batteries. The metal-air battery may be a primary battery or a secondary battery. The materials used to form the positive electrode catalyst layer, negative electrode, electrolyte, separator, and support may be known or commercially available materials that are conventionally used in metal-air batteries. The electrolyte may be in the form of a liquid, a gel, or a solid.
Advantageous Effects of Invention
[0140] According to the present invention, a laminate having good adhesion between the support (separator or conductive porous layer) and the conductive layer can be provided.
[0141] According to the present invention, a laminate having good adhesion between the conductive layer A and the conductive layer B, and having reduced film thickness variation in each conductive layer can be provided.
DESCRIPTION OF EMBODIMENTS
[0142] The present invention is explained in detail with reference to the Examples and Comparative Examples; however, the present invention is not limited to the following examples.
<Materials>
[0143] The materials shown below were used for preparation of the conductive layer A-forming paste composition and the conductive layer B-forming paste composition.
[0000] Conductive carbon particles: Furnace black (Balkan xc72R: produced by Cabot Corporation), average molecular weight: 1,000 to 3,000, average particle diameter: 30 nm
Conductive carbon fibers (1): VGCF (VGCF (registered trademark) (standard product): produced by Showa Denko K.K.; average fiber diameter: 150 nm, average fiber length: 10 to 20 μm, and average aspect ratio: 10 to 500)
Conductive carbon fibers (2): S241 (produced by Osaka Gas Chemical, Co., Ltd.; average fiber diameter: 13 μm, average fiber length: 130 μm, and average aspect ratio: 10)
Polymer (1): Nafion (a 5 wt % Nafion solution “DE-520” produced by Du Pont, Inc., was used), Tg: 130° C.
Polymer (2): Solef21216/1001 (produced by Solvay Solexis; PVDF; solids content: 10 wt %), Tg: −30° C.
Polymer (3): Polytetrafluoroethylene (PTFE) (AD911L: produced by Asahi Glass Co., Ltd.), Tg: about 130° C.
Dispersant: Emulgen A-60 (produced by Kao Corporation)
Example 1
[0144] Conductive carbon particles (100 parts by weight), polymer (3) (50 parts by weight), conductive carbon fibers (1) (75 parts by weight), polymer (1) (1,250 parts by weight (solids content: 62.5 parts by weight)), dispersant (25 parts by weight), and water (350 parts by weight) were subjected to media dispersion to prepare a conductive layer A-forming paste composition. The conductive layer A-forming paste composition was applied to a polyethylene terephthalate (PET) film including a release layer to a thickness of about 50 μm using an applicator. Regarding the viscosity of the paste composition, the shear viscosity was about 150 mPa·s at a shear rate of 1,000 (1/s). The viscosity of the paste composition was measured using a Physica MCR301 produced by Anton Paar GmbH (a cone-shaped jig with a diameter of 50 mm and an angle of 1° was used as a jig). The paste compositions used in other Examples and Comparative Examples were measured in the same manner. Subsequently, drying was performed in a drying furnace set at 95° C. for about 15 minutes to produce a conductive layer (A-1). In the conductive layer (A-1), the polymers (polymers (1) and (3)) were present with a higher density at the surface in contact with the PET film.
[0145] Subsequently, the conductive layer (A-1) was detached from the PET film including the release layer, and the surface of the conductive layer (A-1) having the polymers (polymers (1) and (3)) with a higher density was brought into contact with the surface of a metal separator obtained by applying gold after the formation of a flow channel on a stainless steel substrate. Hot-pressing was then performed at a pressing temperature of 120° C. and a pressing pressure of 15 kN, for a pressing time of 2 minutes to produce the laminate of Example 1.
Example 2
[0146] A conductive layer (A-1) was produced in the same manner as in Example 1.
[0147] Subsequently, the conductive layer (A-1) was detached from the PET film including the release layer, and the surface of the conductive layer (A-1) having the polymers (polymers (1) and (3)) with a higher density was brought into contact with the surface of carbon paper (carbon paper TGPH090 produced by Toray Industries, Inc.). Hot-pressing was then performed at a pressing temperature of 120° C. and a pressing pressure of 25 kN, for a pressing time of 2 minutes to produce the laminate of Example 2.
Example 3
[0148] Polymer (2) was added to methyl ethyl ketone (MEK), and the mixture was stirred at 80° C. for 60 minutes using a stirrer (media rotation speed: 300 rpm), thereby obtaining a PVDF solution having a solids content (polymer (2)) of 10 wt % in which polymer (2) was dissolved in the methyl ethyl ketone. Conductive carbon fibers (2) (100 parts by weight), the prepared PVDF solution having a solids content of 10 wt % (100 parts by weight), and methyl ethyl ketone (50 parts by weight) were subjected to media dispersion to prepare a conductive layer A-forming paste composition. The conductive layer A-forming paste composition was applied to a polyethylene terephthalate (PET) film including a release layer to a thickness of about 50 μm using an applicator. Regarding the viscosity of the paste composition, the shear viscosity was about 437 mPa·s at a shear rate of 1,000 (1/s). Subsequently, drying was performed in a drying furnace set at 95° C. for about 15 minutes to produce a conductive layer (A-2). In the conductive layer (A-2), the polymer (polymer (2)) was present with a higher density at the surface in contact with the PET film.
[0149] Subsequently, the conductive layer (A-2) was detached from the PET film including the release layer, and the surface of the conductive layer (A-2) having the polymer (polymer (2)) with a higher density was brought into contact with the surface of a metal separator obtained by applying gold after the formation of a flow channel on a stainless steel substrate. Hot-pressing was then performed at a pressing temperature of 150° C. and a pressing pressure of 100 kN, for a pressing time of 2 minutes to produce the laminate of Example 3.
Example 4
[0150] A conductive layer (A-2) was produced in the same manner as in Example 3.
[0151] Subsequently, the conductive layer (A-2) was detached from the PET film including the release layer, and the surface of the conductive layer (A-2) having the polymer (polymer (2)) with a higher density was brought into contact with the surface of carbon paper (carbon paper TGPH090 produced by Toray Industries, Inc.). Hot-pressing was then performed at a pressing temperature of 150° C. and a pressing pressure of 100 kN, for a pressing time of 2 minutes to produce the laminate of Example 4.
Example 5
[0152] Conductive carbon particles (100 parts by weight), polymer (3) (50 parts by weight), conductive carbon fibers (1) (75 parts by weight), polymer (1) (1,250 parts by weight (solids content: 62.5 parts by weight)), dispersant (25 parts by weight), and water (350 parts by weight) were subjected to media dispersion to prepare a conductive layer B-forming paste composition. The conductive layer B-forming paste composition was applied to a polyethylene terephthalate (PET) film including a release layer to a thickness of about 50 μm using an applicator. Regarding the viscosity of the paste composition, the shear viscosity was about 150 mPa·s at a shear rate of 1,000 (1/s). Thereafter, drying was performed in a drying furnace set at 95° C. for about 15 minutes to produce a conductive layer (B-1). In the conductive layer (B-1), the polymers (polymers (1) and (3)) were present with a higher density at the surface in contact with the PET film. The conductive layer (B-1) produced was the same as the conductive layer (A-1) produced in Example 1.
[0153] The surface opposite to the surface of the conductive layer (B-1) having the polymers (polymers (1) and (3)) with a higher density was brought into contact with the surface of the conductive layer (A-1) of the laminate produced in Example 1, and hot-pressing was performed at a pressing temperature of 120° C. and a pressing pressure of 100 kN, for a pressing time of 2 minutes to produce the laminate of Example 5.
Example 6
[0154] The surface opposite to the surface of the conductive layer (B-1) having the polymers (polymers (1) and (3)) with a higher density was brought into contact with the surface of the conductive layer (A-1) of the laminate produced in Example 2, and hot-pressing was then performed at a pressing temperature of 120° C. and a pressing pressure of 100 kN, for a pressing time of 2 minutes to produce the laminate of Example 6.
Comparative Example 1
[0155] The laminate of Comparative Example 1 was produced in the same manner as in Example 1 except that the conductive layer (A-1) was detached from the PET film including the release layer, the surface opposite to the surface of the conductive layer (A-1) having the polymers (polymers (1) and (3)) with a higher density was brought into contact with the surface of a metal separator obtained by applying gold after the formation of a flow channel on a stainless steel substrate, and hot-pressing was performed at a pressing temperature of 120° C. and a pressing pressure of 15 kN, for a pressing time of 2 minutes.
Comparative Example 2
[0156] The laminate of Comparative Example 2 was produced in the same manner as in Example 2 except that the conductive layer (A-1) was detached from the PET film including the release layer, the surface opposite to the surface of the conductive layer (A-1) having the polymers (polymers (1) and (3)) with a higher density was brought into contact with the surface of carbon paper (carbon paper TGPH090 produced by Toray Industries, Inc.), and hot-pressing was performed at a pressing temperature of 120° C. and a pressing pressure of 25 kN, for a pressing time of 2 minutes.
Comparative Example 3
[0157] The laminate of Comparative Example 3 was produced in the same manner as in Example 3 except that the conductive layer (A-2) was detached from the PET film including the release layer, the surface opposite to the surface of the conductive layer (A-2) having the polymer (polymer (2)) with a higher density was brought into contact with the surface of a metal separator obtained by applying gold after the formation of a flow channel on a stainless steel substrate, and hot-pressing was performed at a pressing temperature of 150° C. and a pressing pressure of 100 kN, for a pressing time of 2 minutes.
Comparative Example 4
[0158] The laminate of Comparative Example 4 was produced in the same manner as in Example 4 except that the conductive layer (A-2) was detached from the PET film including the release layer, the conductive layer (A-2) having the polymer (polymer (2)) with a higher density was brought into contact with the surface opposite to the surface of carbon paper (carbon paper TGPH090 produced by Toray Industries. Inc.), and hot-pressing was performed at a pressing temperature of 150° C. and a pressing pressure of 100 kN, for a pressing time of 2 minutes.
Reference Example 1
Production of Catalyst Layer Laminated Membrane
[0159] 4 g of platinum catalyst-supporting carbon particles (“TEC10E50E” produced by Tanaka Kikinzoku Kogyo), 40 g of an ion-conductive polymer electrolyte solution (Nafion 5 wt % solution: “DE-520” produced by Du Pont, Inc.), 12 g of distilled water, 20 g of n-butanol, and 20 g of t-butanol were added, and mixed while being stirred using a disperser, thereby obtaining an anode catalyst layer-forming paste composition and a cathode catalyst layer-forming paste composition.
[0160] The anode catalyst layer-forming paste composition and the cathode catalyst layer-forming paste composition were each individually applied to a transfer substrate (material: polyethylene terephthalate film) using an applicator, and dried at 95° C. for 30 minutes to form catalyst layers, thereby obtaining an anode catalyst layer-forming transfer sheet and a cathode catalyst layer-forming transfer sheet. The coating amount of the catalyst layer was determined so that both of the anode catalyst layer and the cathode catalyst layer had a platinum-supporting amount of about 0.45 mg/cm 2 .
[0161] Using the anode catalyst layer-forming transfer sheet and the cathode catalyst layer-forming transfer sheet produced above, hot-pressing was performed on front and back surfaces of the electrolyte membrane (Nafion membrane “NR-212” produced by Du Pont, Inc.; film thickness: 50 μm) at 135° C. and 5 MPa for 2 minutes, and then each of the transfer substrates alone was detached. The catalyst layer laminated membrane was thus produced.
Example 7
[0162] Two laminates produced according to Example 5 were prepared. The laminates were disposed in a manner such that the conductive layer (B-1) side surface of each laminate was in contact with each of the catalyst layer surfaces of the catalyst layer laminated membrane obtained in Reference Example 1. Hot pressing was performed at a pressing temperature of 100° C., pressing pressure of 7.5 kN, and pressing time of 2 minutes, and the solid polymer fuel cell of Example 7 was thus produced.
Example 8
[0163] Two laminates produced according to Example 1 were prepared. Two conductive layers (B-1) produced according to Example 5 were also prepared.
[0164] Each conductive layer (B-1) was detached from the PET film including the release layer, and the surface of the conductive layer (B-1) having the polymers (polymers (1) and (3)) with a higher density was brought into contact with each side of the catalyst layer laminated membrane obtained in Reference Example 1. Hot pressing was performed at a pressing temperature of 100° C., pressing pressure of 7.5 kN, and pressing time of 2 minutes to produce a laminate in which the conductive layer (B-1) was formed on both sides of the catalyst layer laminated membrane.
[0165] Subsequently, the laminates obtained according to Example 1 were disposed in a manner such that the conductive layer (A-1) side surface of each laminate was in contact with each of the conductive layers (B-1) of the laminate produced, and the laminates were stacked to produce the solid polymer fuel cell of Example 8.
Example 9
[0166] The membrane-electrode assembly of Example 9 was produced in the same manner as in Example 8 except that the laminate produced in Example 2 was used in place of the laminate produced in Example 1.
Example 10
[0167] The solid polymer fuel cell of Example 10 was produced in the same manner as in Example 8 except that the laminate produced in Example 3 was used in place of the laminate produced in Example 1.
Example 11
[0168] The membrane-electrode assembly of Example 11 was produced in the same manner as in Example 8 except that the laminate produced in Example 4 was used in place of the laminate produced in Example 1.
Example 12
[0169] The conductive layer A-forming paste composition, which was the same as the paste in Example 3, was prepared. Regarding the viscosity of the paste composition, the shear viscosity was about 437 mPa·s at a shear rate of 1,000 (1/s). The conductive layer A-forming paste composition was applied to a polyethylene terephthalate (PET) film including the release layer, using an applicator to a thickness of about 50 μm. Immediately thereafter, hot air set at 80° C. was applied to the coating side for drying to produce a conductive layer (A-3). In the conductive layer (A-3), the polymer (polymer (2)) was present with a higher density at the surface in contact with the PET film.
[0170] Subsequently, the laminate of Example 12 was produced in the same manner as in Example 3 except that the conductive layer (A-2) was detached from the PET film including the release layer, the surface of the conductive layer (A-2) having the polymer (polymer (2)) with a higher density was brought into contact with the surface of a metal separator to which gold had been applied after the formation of a flow channel of a stainless steel plate, and hot-pressing was performed at a pressing temperature of 150° C. and a pressing pressure of 25 kN, for a pressing time of 2 minutes.
Comparative Example 5
[0171] The conductive layer (A-3) was produced in the same manner as in Example 12. The laminate of Comparative Example 5 was produced in the same manner as in Example 3 except that the conductive layer (A-3) was detached from the PET film including the release layer, the surface opposite to the surface of the conductive layer (A-3) having the polymer (polymer (2)) with a higher density was brought into contact with the surface of a metal separator obtained by applying gold after the formation of a flow channel on a stainless steel substrate, and hot-pressing was performed at a pressing temperature of 150° C. and a pressing pressure of 25 kN, for a pressing time of 2 minutes.
Example 13
[0172] The conductive layer (A-3) was produced in the same manner as in Example 12.
[0173] Subsequently, the conductive layer (A-3) was detached from the PET film including the release layer, the surface of the conductive layer (A-3) having the polymer (polymer (2)) with a higher density was brought into contact with the surface of carbon paper (carbon paper TGPH090 produced by Toray Industries. Inc.), and hot-pressing was performed at a pressing temperature of 150° C. and a pressing pressure of 25 kN, for a pressing time of 2 minutes, thus obtaining the laminate of Example 13.
Comparative Example 6
[0174] The conductive layer (A-3) was produced in the same manner as in Example 12.
[0175] Subsequently, the conductive layer (A-3) was detached from the PET film including the release layer, the surface that was opposite to the surface of the conductive layer (A-3) having the polymer (polymer (2)) with a higher density was brought into contact with the surface of carbon paper (carbon paper TGPH090 produced by Toray Industries. Inc.), and hot-pressing was performed at a pressing temperature of 150° C. and a pressing pressure of 25 kN, for a pressing time of 2 minutes, thus obtaining the laminate of Comparative Example 6.
<Conductive Layer A Evaluation Test 1>
[0176] The conductive layer (A-1) obtained in Example 1, the conductive layer (A-2) obtained in Example 3, and the conductive layer (A-3) obtained in Example 12 were each detached from the PET film including the release layer. The layers were observed by energy dispersion X-ray analysis. Table 1 shows the results. As the analysis device, an EX-23000BU energy dispersion X-ray analysis device produced by JEOL Ltd., was used. The results confirmed that the density of the F element contained in the polymer was different between the front surface and the back surface of each conductive layer; and the polymer was segregated between the front surface and the back surface of the conductive layer A. In Table 1, “PET film contact surface” means the surface that was in contact with the PET film before the PET film was detached from the conductive layer A, and “PET film non-contact surface” means the surface opposite to the PET film contact surface.
[0000]
TABLE 1
Conductive layer (A-1)
Conductive layer (A-2)
Conductive layer (A-3)
PET film
PET film
PET film
PET film
PET film
PET film
Evaluation
non-contact
contact
non-contact
contact
non-contact
contact
element
surface
surface
surface
surface
surface
surface
C
83.77
82.09
92.95
83.47
88.46
87.08
F
14.74
15.75
2.69
16.53
9.15
11.34
<Laminate Evaluation Test 2>
1. Adhesion
[0177] Using a medium-temperature press device (produced by Tester Sangyo, Co., Ltd.), adhesion between the conductive layer (A-1), (A-2), or (A-3) and the metal separator or conductive porous substrate in each of the laminates (50×50 mm 2 ) obtained in Examples 1 to 6 and 12 to 13, and Comparative Examples 1 to 6, was measured.
[0178] Adhesion was subjectively evaluated as to whether layers were adhered together in a manner such that one layer was not detached from another layer. Specifically, adhesion was rated A or B.
[0000] A: Strongly adhered and difficult to detach layers with hands.
B: Easy to detach layers with hands, or no adhesion observed. Table 2 shows the results.
[0000]
TABLE 2
Adhesion
state
Example 1
A
Example 2
A
Example 3
A
Example 4
A
Example 5
A
Example 6
A
Example 12
A
Example 13
A
Comp. Exam. 1
B
Comp. Exam. 2
B
Comp. Exam. 3
B
Comp. Exam. 4
B
Comp. Exam. 5
B
Comp. Exam. 6
B | 4y
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation in part of pending U.S. application Ser. No. 09/141,960 filed Aug. 28, 1998, and pending application PCT/US99/19477 filed Aug. 30, 1999 (now published as WO012155A1: An Improved Soft Shell Venous Reservoir) the disclosures of these applications being incorporated herein by reference thereto.
GOVERNMENT INTERESTS
[0002] This invention was in part made with government support under an SBIR Grant # R44-HL55034 awarded by the National Institute Health, National Heart, Lung, and Blood Institute. As such the government may have certain rights in the invention.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The invention is a blood reservoir with at least one pliable wall having at least three innovative features. First, the compliant reservoir is sealed within a rigid housing allowing control of the “atmospheric” pressure surrounding the bag, and therefore the pressure at which the bag would collapse. This first invention enables vacuum augmented venous drainage (VAVD) with a collapsible soft-shell reservoir (i.e. venous bag) and is particularly useful for cardiopulmonary bypass. Second, the invention incorporates means that improve gas bubble removal from blood transiting the collapsible reservoir. Third, a reservoir with all ports extending from its top is disclosed, an innovation that provides easy loading/unloading of the reservoir in/out of its holder and simplifies sealing the reservoir in a chamber thereby allowing the aforementioned VAVD.
[0005] 2. Description of the Prior Art
[0006] Blood is routinely pumped outside the body during dialysis, cardiopulmonary bypass, and long-term cardiac and/or respiratory support (e.g. extracorporeal membrane oxygenation, ECMO). In general, blood flows from the venous side of the patient to a venous reservoir that is usually maintained at atmospheric pressure. Blood flow from the patient to the reservoir is a function of the resistance of the fluid conduit between patient and reservoir, and the pressure difference between patient and reservoir. When the reservoir is maintained at atmospheric pressure, that pressure difference is the height difference between patient and reservoir; the resulting flow is referred to as gravity drainage. Venous drainage by gravity alone provides inadequate return during procedures such as minimally invasive cardiac surgery and bypass via femoral cannulation. Usually it is the resistance of the venous cannula that limits the flow achievable. Vacuum augmented venous drainage (VAVD) is a technique that overcomes flow limitations by applying suction to the hard shell reservoir thereby increasing the pressure difference between the venous cannulation site and venous reservoir. VAVD allows for a decrease in the inner diameter of the venous line, thereby reducing prime volume and enabling the use of a smaller cannula, which translates to an easier insertion, a better surgical view and a smaller surgical incision. This method precludes the use of the safer soft-shell closed venous reservoir (venous bag) unless a more expensive and complicated two-pump system is used (see McKusker K, Hoffman D, Maldarelli W, Toplitz S, and Sisto D. High-flow femoro-femoral bypass utilizing small cannulae and a centrifugal pump on the venous side. Perfusion 1992; 7:295-300).
[0007] Clinically, a venous bag is used because it provides significant safety features. If the bag empties, it collapses, thereby preventing gross air from being pumped to the patient. It usually has no air-blood interface, and it requires no antifoam agents that can embolize into the blood. A recent study by Schonberger et al (Schonberger JPAM, Everts PAM, and Hoffmann J J. “Systemic blood activation with open and closed venous reservoirs. Annals of Thoracic Surgery, 1995; Vol. 59, pages 1549-55) comparing the hard shell to the bag reservoir found significantly lower blood activation, shed blood loss, crystalloid infusion, and hemolysis, and less donor blood infusion with the bag reservoir. Schonberger's group recommended against routine use of an open (hard shell) venous reservoir system. Currently, a slight negative pressure applied to the venous line (to facilitate blood drainage) using a single pump is possible with less desirable hard shell venous reservoirs. It is impossible to apply negative pressure to current soft-shell reservoirs, but it is possible with the present invention.
[0008] In an open, hard shell reservoir, air escapes by floating to the top of the reservoir. In a bag reservoir, air floats to the top but must be actively eliminated. This can be done manually with a syringe, or more frequently with a roller pump operating slowly so as to continuously pump fluid to the cardiotomy reservoir. With either method, a sudden large volume of air can overwhelm the air removal system and cause disastrous consequences, especially without a vigilant perfusionist. With one preferred embodiment of the present invention, air would be eliminated automatically without a roller pump or intervention by the perfusionist, and priming of the extracorporeal circuit would be facilitated through faster air removal utilizing either a floating ball valve or a hydrophobic membrane. Currently there are devices used in the CPB circuit that incorporate hydrophobic membranes that remove air yet do not allow blood to cross (e.g. Model # AutoVent-SV, Pall Corp Glen Cove N.Y.). Studies with filters used in these applications have shown that the membranes clear air from water almost indefinitely (many days), even if high suction is applied, without reducing gas transfer rate over time. However, when the membrane is exposed to blood, especially when high suction is applied, a film forms on the membrane over time, causing a significant increase in resistance to gas flow. The present invention incorporates designs and means to reduce this problem and extend the life of the membrane when used with blood. Likewise, U.S. Pat. No. 3,849,071 shows a floating ball within a blood filter that supposed to open a purge port when air enters and close when the blood level rises. However, as described, it is a physical impossibility for the ball to “fall” and open the purge port because, as shown, the weight of the floating ball is insufficient to overcome the force holding the ball against the purge port. With the present invention, the relative weight of the ball, the internal diameter of the purge port, and the suction applied to the purge port are designed to assure that the ball will drop to open the purge port in response to air level in the venous reservoir.
[0009] With prior art soft-shell reservoirs (SSR) air may be trapped at the top of the liquid by the collapsed walls of the reservoir, see FIGS. 1 a and 1 aa . U.S. Pat. No. 4,622,032 illustrates a soft shell reservoir having an inlet tube extending from the bottom half way into the reservoir. This arrangement helps bubbles move up to the top of the extended tubes but the bubbles can still be trapped above said tubes. U.S. Pat. No. 5,573,526 illustrate the prior art soft-shell reservoir having its gas removal tubes (i.e. 18 and 20 of FIG. 1) extending from the top less 40% of the height of its blood chamber into the reservoir. All other prior art SSR have air removal tubes that are shorter with many having vent tubes that do not extend into the SSR at all (e.g. U.S. Pat. No. 5,580,349). As FIGS. 1 b and 1 bb illustrates, a tube extending from the top and into the SSR prevents complete collapse of the pliable walls of the bag thereby forming a pathway for air to move upward. The prior SSR air removal tubes extend less than 40% of the height of the blood chamber and therefore air still may be trapped below said tubes.
[0010] A soft shell venous reservoir sold by Johnson and Johnson (and now by Medtronic see reference 13) shows a soft shell reservoir with an inline tube extending, along one side of the bag, to the gas purge port at a 45° incline. This design has a rigid fluid path between blood inlet and gas purge port. However, this design is not as conducive to air removal as a vertical fluid path would be. In addition, the tube extending between inlet tube and purge port had an ID of ⅝″, or only 25% greater diameter than the inlet tube. Thus, the velocity of the liquid in the column slows to only 64% of the inlet velocity. In another aspect of the present invention, a vertical path is provided from the blood inlet at the bottom of the bag to the gas purge port at the top of the bag, such path limiting the aforementioned problem of trapped air. The vertical path also has a large enough diameter that slows the velocity of the liquid to 25% or less of the inlet velocity. A lower blood velocity is more conducive to bubble removal.
[0011] State of the art soft shell venous reservoirs with a screen are designed such that a large portion of the screen contacts the internal walls of the bag, thereby increasing the resistance to blood flow across the screen, and rendering that portion of the screen ineffective, at least partially. This contact between the screen and the walls of the bag increases as the volume in the reservoir decreases. One aspect of the present invention reduces that problem by preventing the external walls of the venous reservoir from contacting the screen.
[0012] The indication of blood level in present soft shell venous reservoir is very inaccurate and low level, or air-in-the-reservoir, alarms are not reliable because many are designed for hard shell reservoirs. The present invention provides effective means to alarm at low blood levels and in the soft shell venous reservoir.
[0013] Currently, at the end of the bypass procedure, the patient is weaned off the heart lung machine by reducing the bypass flow. This is achieved by partially clamping the venous line and decreasing speed of the arterial pump. Once off bypass, the blood left in the venous reservoir is gradually pumped back to the venous side of the patient. Another aspect of the invention allows the user to adjust the positive pressure applied to the blood within the venous reservoir. By being able to increase the pressure of the venous reservoir, the user can effectively reduce venous drainage or perfuse the blood back to the patient. This is not possible with current venous reservoir bags and may be dangerous with hard shell reservoirs (i.e., air may be pushed to the patient).
[0014] The inventor has also previously described an inline bladder (The Better-Bladder™, now U.S. Pat. No. 6,039,078), a device with a thin walled, sausage shaped bladder sealed inside a clear, rigid housing. Since the bladder is made from a single piece of tubing, the blood path is smooth with no flow discontinuities. The bladder portion is sealed within the housing that has an access port to the housing space outside the bladder. Because of its thin wall, the enlarged section can easily collapse. Thus, it can serve as an inline reservoir, providing compliance in the venous line to reduce the pressure pulsations at the pump inlet. The Better-Bladder also transmits the blood pressure flowing through it across its thin wall, allowing pump inlet pressure to be measured noninvasively by measuring the gas pressure of the housing via the gas port. The degree of “gravity drainage” is user-adjustable by setting the negative pressure in the Better-Bladder housing. If the suction generated by the venous pump becomes too great, the pump is slowed or stopped by a pump controller. The Better-Bladder does not have a gas purge port or a screen to inhibit gas bubbles. It is also much smaller, having nominal volume of 80 ml for adult perfusion as compared to over 1,000 ml for a venous reservoir.
[0015] Despite users acknowledgement that SSR are safer, hard shell reservoirs are easier to use and therefore more widely used. For example, it is easier to connect the inlet tubing located at the top of the hard shell reservoir than to the inlet tube of the SSR located at the bottom. Though some SSRs are premounted by the manufacture to a supporting plate (e.g. Cobe see U.S. Pat. No. 5,693,039), most require multiple hanging hooks for proper support (e.g. Baxter's SSR model #BMR1900 has 3 holes at the top and 4 holes at the bottom), an inconvenience at best, a danger in an emergency. Present mounted SSR do not improve the tube connection by much. It would be a clinical advantage to provide a SSR that allows fast mounting and dismounting, and tube connection that are easy or even easier than that of hard shell reservoir. Another requirement for present SSR is the use of a supporting faceplate (e.g. see FIG. 3 of U.S. Pat. No. 5,573,526). These are used to improve the bubble path from the blood to the top of the reservoir. Such faceplates are again inconvenient, require additional assembly time by the user, and may obstruct the direct approach to the front wall of the bag. The latter is useful when bubbles “stuck” on the wall are to be dislodged. The elimination, or at least the reduced requirement, of a front plate is another desirable attribute.
[0016] U.S. Pat. No. 5,823,045 “ Measuring Blood Volume in Soft-Shell Venous Resevoirs (sp.) by Displacement” illustrates a SSR enclosed in a rigid housing. This invention suggests sealing a SSR within a rigid housing but does not suggest applying vacuum to the fluid surrounding the SSR. In fact, neither the figures nor the specifications mention a port for adjusting the fluid in sealed container 12 . Van Driel's patent has some major flaws. The tubes connected to the bag are to be “threaded through resilient seals 26 in the bottom of container 12 . . . ” also renders '045 clinically irrelevant. If, though not described as such, container 12 is disposable, then the system as described is too expensive. If, as understood, container 12 is not disposable, then “threading” the tubes would break sterility, and would be very difficult, especially if a seal is required. Further, since the outside diameter of perfusion connectors are larger than the OD of the tubing they connect, it would be impossible to have any of the tubing of the SSR connected to anything until after they have been threaded. In addition, the housing needs to be sufficiently wide for the user to place their hands and thread the inlet and outlet tubes at the bottom of box 12 , a major disadvantage that hinders quick setup and increases the likelihood of contamination. This invention has not been reduced to clinical practice.
[0017] Since the SSR is sealed in container 12 , external means are provided by '045 to “massage” the SSR with “vibrator” 36 . In fact, since vibrator 36 is not connected to the wall of the SSR, it can only squeeze the wall rather than the pull and push motions required for vibration. This provides significantly less manipulation ability as compared to direct contact with the bag.
[0018] PCT's International Publication Number WO 99/08734 entitled “ System and Method for Minimally Invasive Surgery Vacuum-Assisted Venous Drainage” illustrates in FIG. 9 a standard SSR (“preferably BMR-800 or BMR-1900”) completely sealed in a rigid housing. It is also suggested that “ . . . a pressure differential between the interior and exterior of the reservoir . . . ” be maintained. This design is as impractical as that of U.S. Pat. No. '045. If the bag and rigid housing are assembled and shipped to the end user as a single unit, the unit becomes very expensive and therefore would be used only for VADV cases. The expense arises from a housing required to support a large force. The force can be calculated as (Pressure)*(Area). Thus, to support a pressure of −250 mmHg with a safety factor of 2 for a box that holds a bag like the BMR-1900 (10″ high by 12″ wide), the force on each faceplate is 1200 lb! The inventors did not suggest, nor showed or described, a mechanism for the user to seal the bag in the box. Even if there was a mechanism, it would be very difficult, time consuming, and, as described with relation to '045, most likely to break sterility. And, once sealed it would be impossible for the user to contact the bag.
[0019] Both '045 and '08734 illustrate the rigid housing as a rectangular box. A better design to support the large external force due to the large area and vacuum used would be an ellipsoid cross section or at least rounded corners.
[0020] Both '045 and '08734 illustrate the great need for designs that allow simple, inexpensive, and quick means to seal and remove the bag from its container even with long tubing or large connectors without affecting its sterility. Simple and quick means to reach the enclosed bag would also be welcomed. The present invention overcomes these clinically non-workable prior art designs.
[0021] It is standard practice to place the venous reservoir above the oxygenator to assure that the microporous membrane is always under positive pressure. A negative pressure would result in air crossing the membrane and entering the arterial line, a very dangerous situation. When VAVD is used, suction can be applied to the venous reservoir only once the arterial pump is generating a positive pressure in the arterial line. Otherwise, the suction applied to the venous reservoir can draw air across the membrane. A one-way valve at the pump outlet prevents vacuum applied to the venous reservoir from reaching the membrane oxygenator, but a one-way valve incorporated into the outlet of the present venous reservoir is preferable. Means to assure that the gas side of the membrane oxygenator is always positive relative to the blood side would also be a major safety feature for all VAVD applications.
BRIEF SUMMARY OF THE INVENTION
[0022] The present invention incorporates improved designs for venous reservoirs that provide the benefits of prior art devices (limiting pump suction using the safer, pliable blood reservoir) while avoiding their disadvantages (air entrapment, inability to utilize VAVD, required vigilance for air removal). Further, its advantages and uniqueness are also enhanced by providing the user with means to adjust the degree of suction applied for venous augmentation and assuring that a greater area of the screen is effective in liquid transport.
[0023] Briefly, the present invention in its simplest form consists of a blood reservoir having at least one pliable wall, a blood inlet, a blood outlet, and a gas purge port. In one preferred embodiment, a first structure having tubular cross section and semirigid wall is placed above said inlet thereby providing a first path for undesirable bubbles entering the reservoir to move to the top where they are eliminated via said gas purge port. The first structure preferably has an effective cross section that is larger than the ID of said inlet tube thereby slowing any blood flow and allowing more favorable conditions (longer time, lower drag) for gas bubbles to float upward. The wall of the first structure is sufficiently rigid to prevent collapse of said pliable wall from blocking said first path. In another preferred embodiment, the pliable wall of the venous reservoir is sealed externally, forming a pressure chamber external to the venous reservoir. Controlled suction applied to said external chamber is transmitted across said pliable wall thereby controlling the negative pressure of the blood at which said pliable wall moves.
[0024] Another preferred embodiment has all the tubes at the top of the SSR. These tubes pass through, sealed within, and physically supported by a rigid disposable supporting plate providing three major advantages. First, the bag is supported by hanging the supporting plate in a supporting fixture, much like the hard shell reservoir. This allows the user to “drop in” the SSR and just as easily remove the SSR from its holder. Second, the supporting plate provides simple sealing means along a single plane, an extremely important feature for simple and secure sealing of the SSR within housing for VAVD applications. Third, by having all the tubes for the bag entering from its top, the bottom of the bag is unhindered and can be placed lower to the floor allowing greater gravity drainage. In addition, because the bag hangs from the top, the weight of the SSR/blood contributes to the seal of the supporting plate against the housing. Designed properly, this gravitational force can eliminate or greatly simplify any clamping required by other designs.
[0025] It is therefore the objective of the present invention to provide an improved venous blood reservoir with at least one pliable wall that provides a path for gas bubbles entering the inlet to move unhindered up to the gas purge port.
[0026] A further objective of the present invention is an improved venous blood reservoir, having at least one pliable wall, allowing the user to adjust the negative pressure applied to said pliable wall thereby allowing for augmented venous drainage.
[0027] A further objective of the present invention is an improved venous blood reservoir designed to maintain its external wall from contacting the screen material and thereby reducing the resistance to blood flow across the screen.
[0028] Yet another objective of the present invention is to incorporate a one-way valve at the outlet of the venous reservoir, said valve preventing blood from being sucked into the venous reservoir when pressure at the outlet of the venous reservoir is positive relative to the liquid pressure in the venous reservoir.
[0029] Another objective of the present invention is to provide an improved venous blood reservoir with at least one pliable wall that when placed at the pump inlet, provides compliance that reduces pressure fluctuations at said pump inlet.
[0030] Another objective of the present invention is to provide an improved venous blood reservoir with at least one pliable wall that when placed at the pump inlet, provides automated means to eliminate air.
[0031] Another objective of the present invention is to provide an improved venous blood reservoir with at least one pliable wall and with a relatively large gas purge port, said port providing a more volumetrically effective gas purge, and one that is less traumatic to the blood.
[0032] Another objective of the present invention is to provide automated means to detect air in the venous reservoir and utilize said means to alarm the user or control the suction used to remove air from the venous reservoir.
[0033] Another objective of the present invention is to provide the user with a SSR that is simple to use, and easy to load and unload from its holder or from its container.
[0034] Another objective of the present invention is to provide the user with a SSR having all its connections above the bag facilitating said connections and allowing a lower placement of the reservoir thus providing greater gravity drainage.
[0035] Another objective of the present invention is to utilize gravity to facilitate sealing of the SSR in its VAVD container.
[0036] Another objective of the present invention is to utilize the applied suction to facilitate sealing the SSR within its VAVD container.
[0037] Another objective of the present invention is to provide a single plane to seal SSR in VAVD container.
[0038] Another objective of the present invention is to provide a non-disposable VAVD container that supports at least −100 mmHg.
[0039] Another objective of the present invention is to provide a disposable cover/holder as part of the SSR for the VAVD container.
[0040] Yet another objective of the present invention is to provide a single venous bag that can be used with either standard or with VAVD thus, reducing cost of inventory and simplifying the user's set up.
[0041] Another objective of the present invention is to provide a disposable SSR incorporating a structure that facilitates sealing the bag within a non-disposable VAVD container, thus reducing cost.
[0042] Another objective of the present invention is to provide a SSR incorporating means to prevent the SSR from pulling out of, or twisting within its holder.
[0043] Another objective of the present invention is to provide a means to allow suction application to both SSR and cardiotomy independent of the height difference between the two.
[0044] Another objective of the present invention is to provide a means to reduce the chance of gas pulled across the microporous membrane when suction is applied to the venous reservoir.
[0045] Another objective of the present invention is to provide a VAVD housing having an ellipsoid cross section that can better support a large external force and streamlined to the shape of the SSR.
[0046] Another objective of the present invention is to provide a VAVD housing for SSR that does not require the user's hands to be placed within said housing when mounting said SSR in said housing. Other objectives, features and advantages of the present invention will become apparent by reference to the following detailed description of the presently preferred, but nonetheless illustrative, embodiments thereof with reference to the accompanying drawings therein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] [0047]FIG. 1 is a line drawing of the pertinent components of a typical cardiopulmonary bypass (CPB) circuit showing the relative location of the venous reservoir of the present invention.
[0048] [0048]FIG. 1 a is a line drawing of a typical prior art venous reservoir illustrating how incoming air bubbles are prevented from reaching the gas exhaust port and are trapped midway in the bag.
[0049] [0049]FIG. 1 aa is a line drawing of a cross section taken of FIG. 1 a along line 1 a - 1 a′.
[0050] [0050]FIG. 1 b is a line drawing of a typical venous reservoir according to the present invention, illustrating a pathway provided by channels formed along a tube extended into bag.
[0051] [0051]FIG. 1 bb is a line drawing of a cross section taken of FIG. 1 b along line 1 b - 1 b′.
[0052] [0052]FIG. 2 a is a line drawing illustrating one preferred embodiment of the present invention where a perforated cylinder is used to keep the flexible walls of the venous reservoir bag away from its screen as well as provide an uninterrupted fluid path between blood inlet and gas exhaust port.
[0053] [0053]FIG. 2 b is a line drawing of a cross section taken of FIG. 2 a along line 15 - 15 ′.
[0054] [0054]FIG. 2 c is a line drawing of a cross section taken of FIG. 2 a along line 16 - 16 ′.
[0055] [0055]FIG. 2 cc is an enlarged view of the circled section taken from FIG. 2 c.
[0056] [0056]FIG. 2 d is a line drawing of a cross section taken of FIG. 2 a along line 17 - 17 ′.
[0057] [0057]FIG. 2 e is a line drawing illustrating the flow of blood and air at the inlet of the venous reservoir shown in FIG. 2 a.
[0058] [0058]FIG. 2 f is a line drawing illustrating one preferred method to assemble the screen used with the venous reservoir shown in FIG. 2 a.
[0059] [0059]FIG. 3 a is a line drawing illustrating one preferred sealing scheme of an adult size venous reservoir that allows the use of a universal holder for it and the pediatric venous reservoir shown in FIG. 3 b.
[0060] [0060]FIG. 3 b is a line drawing illustrating one preferred sealing scheme of a pediatric size venous reservoir that allows the use a universal holder for it and the adult venous reservoir shown in FIG. 3 a.
[0061] [0061]FIG. 4 is a line drawing illustrating one preferred embodiment of the present invention where the venous reservoir is topped with a microporous membrane that allows air, but not blood, to be removed.
[0062] [0062]FIG. 5 a is a line drawing illustrating another preferred embodiment of a microporous membrane placed at the top of the venous reservoir allowing air, but not blood, to be removed.
[0063] [0063]FIG. 5 b is a line drawing of a cross section taken of FIG. 5 a along line b-b′.
[0064] [0064]FIG. 6 a is a line drawing illustrating one preferred embodiment of the present invention where air removal is automated by utilizing a floating ball valve.
[0065] [0065]FIG. 6 b is a line drawing illustrating another view of the bottom of the ball cage used in FIG. 6 a taken along line 23 - 23 ′.
[0066] [0066]FIG. 6 c is a line drawing illustrating another view of the ball cage used in FIG. 6 a taken along line 24 - 24 ′.
[0067] [0067]FIG. 6 d is a line drawing illustrating another embodiment of the present invention where air removal is automated by utilizing a floating ball valve incorporating two safety features.
[0068] [0068]FIG. 7 a is a line drawing illustrating another preferred embodiment of the present invention where a rigid cylinder, incorporated as one external wall of the venous reservoir, maintains the screen wall unhindered and provides an uninterrupted fluid path between blood inlet and gas exhaust port.
[0069] [0069]FIG. 7 b is a line drawing of a cross section taken of FIG. 7 a along line 25 - 25 ′.
[0070] [0070]FIG. 7 c illustrates rigid cylinder 72 , shown in FIG. 7 a , isolated and rotated 90° clockwise.
[0071] [0071]FIG. 7 d is an enlarged view of the top, circled section of the venous reservoir shown in FIG. 7 a illustrating the slot providing communication for removal of air external to the screen.
[0072] [0072]FIG. 7 e is a line drawing of a cross section taken of FIG. 7 d taken along line 26 - 26 ′.
[0073] [0073]FIG. 7 f is a line drawing of a cross section taken of FIG. 7 e taken along line 27 - 27 ′.
[0074] [0074]FIG. 8 a is a line drawing illustrating one preferred embodiment of the present invention where a venous reservoir can be sealed within a rigid housing where suction can be applied to the external flexible walls of said reservoir thereby providing venous augmentation.
[0075] [0075]FIG. 8 b is a line drawing of a cross section taken of FIG. 8 a along line 28 - 28 ′.
[0076] [0076]FIG. 8 c is a line drawing of a cross section taken of FIG. 8 a along line 29 - 29 ′ illustrating the rigid bottom cap used with the venous reservoir to seal the bottom of the housing shown in FIG. 8 a.
[0077] [0077]FIG. 9 a is a line drawing of another preferred embodiment of the present invention wherein the venous reservoir can be sealed within a rigid housing where suction can be applied to the external flexible walls of said reservoir thereby providing venous augmentation.
[0078] [0078]FIG. 9 b is a line drawing of a cross section taken of FIG. 9 a along line 30 - 30 ′ showing the bottom seal of the venous reservoir within the housing and door shown in FIG. 9 a.
[0079] [0079]FIG. 9 c is a line drawing of a cross section taken of FIG. 9 a along line 31 - 31 ′ showing the top seal of the venous reservoir within the housing and door shown in FIG. 9 a.
[0080] [0080]FIG. 9 d is a line drawing of a cross section taken of FIG. 9 a along line 32 - 32 ′ showing another preferred sealing means incorporated into the inlet tube of the venous reservoir shown in FIG. 9 a.
[0081] [0081]FIG. 9 e is a line drawing of a cross section taken of FIG. 9 d along line 33 - 33 ′ showing a top view of the means incorporated into the inlet tube of the venous reservoir shown in FIG. 9 a.
[0082] [0082]FIG. 9 f is a line drawing identical to that shown in FIG. 9 d except that this embodiment incorporates a gasket having an indentation to seal about the inlet tube of the reservoir, and a deeper indentation in the housing to support said tube while the venous reservoir is loaded.
[0083] [0083]FIG. 10 a is a three dimensional rendering of another preferred embodiment illustratingun adaptation of the present invention to other venous reservoir having at least one flexible wall by sealing said flexible wall within a rigid housing such that suction can be applied externally to said flexible wall, thereby providing venous augmentation.
[0084] [0084]FIG. 10 b is a line drawing of a longitudinal cross sectional view of FIG. 10 a.
[0085] [0085]FIG. 10 c is a line drawing of a cross section taken of FIG. 10 b along line 10 c - 10 c ′ showing another view of the venous reservoir within the housing shown in FIG. 10 a.
[0086] [0086]FIG. 11 is a line drawing illustrating another embodiment of the present invention where air removal is automated by connecting the gas exhaust port of the venous reservoir to the inlet port of a cardiotomy reservoir, said cardiotomy having negative pressure applied to it.
[0087] [0087]FIG. 12 a is a line drawing illustrating another preferred embodiment of the present invention, similar to that shown in FIG. 8 a , except that all the tubes entering the bag enter from the bottom and incorporate a disposable cover plate.
[0088] [0088]FIG. 12 b is a line drawing of a cross section taken of FIG. 12 a along line 112 - 112 ′.
[0089] [0089]FIG. 12 c is line drawing of a cross section taken of a bottom view of cover 89 of FIG. 12 a along line 29 - 29 ′.
[0090] [0090]FIG. 13 a is a line drawing illustrating one preferred embodiment of the present invention where all the tubes entering the bag enter from the top and are supported by a disposable supporting plate.
[0091] [0091]FIG. 13 b is a line drawing of a cross section taken of FIG. 13 a along line 131 - 131 ′.
[0092] [0092]FIG. 13 c is line drawing of a cross section taken of a top view of cover 1389 of FIG. 13 a along line 132 - 132 ′.
[0093] [0093]FIG. 13 d is line drawing of a front view of a SSR shown in FIG. 13 a having an outlet section with the outlet tube centered at the bottom and connected to the side wall of the bag.
[0094] [0094]FIG. 13 dd is a line drawing of a cross section taken of FIG. 13 d along line 133 - 133 ′.
[0095] [0095]FIG. 13 e is line drawing of a front view of a SSR shown in FIG. 13 a having a different outlet section with the outlet tube on the side and connected to the side wall of the bag.
[0096] [0096]FIG. 13 ee is a line drawing of a cross section taken of FIG. 13 e along line 134 - 134 ′.
[0097] [0097]FIG. 13 f is line drawing of a preferred embodiment of top cover 1389 shown in FIG. 13 a and a combination of components designed to reduce the chance of air crossing the into the arterial line by applying controlled suction to the gas side of the oxygenator.
DETAILED DESCRIPTION OF THE INVENTION
[0098] Reference should now be made to the drawings wherein the same reference numerals are used throughout to designate the same or similar parts. It should be noted that the use of cardiopulmonary bypass, as shown in FIG. 1, is for descriptive purposes, and should not be taken as a limitation to the use of the devices described hereinafter. It should also be noted that the term soft shell reservoir, venous bag and bag are used interchangeably.
[0099] [0099]FIG. 1 is a schematic representation of a system according to the present invention and showing the relative location of the venous reservoir in a typical cardiopulmonary bypass circuit. As shown, tubing 123 is inserted at one end by means of a cannula (not shown) in the vena cavae for obtaining venous blood from the heart (not shown) of patient 1102 . Tubing 123 is coupled, as an example, to venous reservoir 1103 . The blood is drawn from venous reservoir 1103 via tube 135 by roller pump 1104 and pumped through a membrane oxygenator 1105 wherein oxygen is supplied to the blood and carbon dioxide is removed. The blood from the oxygenator is then conducted by means of tubing 157 to arterial filter 1107 and then via tubing 172 and an arterial cannula (not shown) back to the patient. As described in the prior art, the venous blood, here shown coming from the patient's vena cavae, may contain air that must be eliminated before it is pumped back to the patient. This is one of the main functions of the venous reservoir. As shown, air entering venous reservoir 1103 rises to the top of said reservoir where it is removed by suction pump 1114 to cardiotomy reservoir 1115 . Roller pump 1104 is usually one of 3 to five pumps composing a heart-lung machine, which is part of a hardware required for cardiopulmonary bypass.
[0100] [0100]FIGS. 2 a , 2 b , 2 c , 2 d and 2 e illustrate line drawings of one preferred embodiment of the present invention. Here, venous blood enters the venous reservoir 1819 via inlet tube 1 and is directed into first inlet chamber 2 , shown as a cutaway. First inlet chamber 2 preferably has a circular cross section with its walls formed of fine screen 3 typically having a pore size of 40μ to 150μ and having an effective open area that is preferably greater than 40%. It is understood that though lower pore sizes result in higher resistance to blood flow, they prevent smaller bubbles from crossing the screen. It should also be understood that screen 3 is preferably heparin coated, to increase wettability and reduce clot formation. The top of chamber 2 is in fluid communication with gas purge port 4 . The bottom of chamber 2 is open and is in fluid communication with inlet tube 1 and, via expandable chamber 8 , with outlet tube 5 . Preferably outlet tube 5 is located on the opposite side of, and lower than, inlet tube 1 .(Bentley patent?)
[0101] In one of the preferred embodiment, shown in FIG. 2 a , first inlet chamber 2 has a larger inside diameter than inlet tube 1 (e.g. 1.0″ v. 0.5″), said larger diameter serves to slow the velocity of the blood (e.g. ¼ the inlet velocity), and thus allow more time for any bubbles to rise to the top where they can be removed. Slowing the blood also reduces the tendency of the flowing blood to carry the bubbles, especially the smaller ones, by reducing the drag on the bubbles by the moving blood. Lower velocity also lowers the tendency of larger bubbles to break into smaller ones; larger bubbles have a higher buoyancy and less of a chance of crossing screen 3 into expandable chamber 8 , and flowing out of the bag through outlet tube 5 shown in FIG. 2 a . With sufficient pressure across screen 3 , the bubbles could cross into chamber 8 and travel to outlet 5 of the reservoir, a very undesirable outcome. To reduce that possibility, inlet chamber 2 is open at the bottom where debubbled blood can exit first inlet chamber 2 at 2 a . To improve flow conditions, the outlet of inlet tube 1 , 1 a , is preferably centered with the centerline of chamber 2 , as also shown in FIG. 2 b (cross-section 15 - 15 ′ in FIG. 2 a ). Also shown is one preferred embodiment of structure 28 that centers inlet tube 1 within chamber 2 formed by screen 3 . Connector 28 , shown in FIG. 2 a and as a cross section taken of FIG. 2 a along line 15 - 15 ′ shown in FIG. 2 b , lines up and connects inlet tube 1 to inlet chamber 2 . Thus, in one preferred embodiment, connector 28 has a wheel cross-section with an internal circular structure 28 a connected via spokes 28 b to an external circular structure 28 c . The inside diameter of inside structure 28 a that allows interference fitting to the outside diameter of inlet tube 1 and the outside diameter of outside structure 28 c supports cylinder 6 . The space between internal structure 28 a and outside structure 28 c maintained by spokes 28 b forms a fluid communication between inlet chamber 2 and expandable chamber 8 as indicated by the downward facing arrow at the bottom of FIG. 2 e . It should also be obvious that since screen 3 may be flimsy, it may need radial support, as for example internal cage 26 , see FIG. 2 c (cross section 16 - 16 ′ in FIG. 2 a ) and 2 f . Screen 3 can be attached to cage 26 by various means (e.g. insert molding) longitudinally and radially to 26 a or 26 b and longitudinally to ribs 26 c , for example, by adhesive. This would maximize the ID of first internal chamber 2 to provide a smooth and straight vertical flow path thereby facilitating the upward motion of the bubbles.
[0102] With this design, as is the case for present venous reservoir bags (e.g. Bentley, Cobe, Sarns/3M, Minntech) most of the incoming blood would exit via screen 3 across which very few bubbles, if any, cross. However, present venous reservoir bags are made of four layers: the two outside layers being flexible PVC sheets and the two inside layers being a screen (e.g. U.S. Pat. No. 4,734,269). The screen is usually folded over with the fold being in the center of the venous reservoir bag and its edges sandwiched and sealed along at least two of edges of the two PVC outer layers. This design is simple but it provides no means to keep the internal surface of the external PVC walls from contacting the external wall of the screen. This contact reduces the effective screen area available for blood flow, especially at low blood volumes, causing further problems because more bubbles cross the screen at lower blood volumes. For example, tests conducted with the Cobe venous reservoir bag (Model # VRB, Cobe Lakewood, Colo.) showed that at a blood flow of 4.0 L/min and an air flow of 750 mL/min, the bubble count (size> 50μ) with a blood volume of 750 ml in the bag was 35 bubbles/sec as compared to 94 bubbles/sec when the blood volume was 500 ml. The Baxter venous reservoir bag (Model #BMR-1900, Baxter/Bentley Irvine, Calif.) had similar results: the bubble count increased from 69 bubbles/sec to 160 bubbles/sec when the blood volume decreased from 750 to 500 ml.
[0103] The present invention eliminates the problem of screen to wall contact by introducing means to maintain the wall of the venous reservoir bag away from the screen as well as to maintain a vertical column of blood within first inlet chamber 2 . This can be achieved by either incorporating the means into the disposable bag, or by interfacing a disposable bag with a nondisposable holder, the combination providing the aforementioned means. FIG. 2 a illustrates one preferred embodiment of the disposable type. Here, a semi rigid cylinder 6 with perforated wall is placed over screen 3 forming second inlet chamber 7 in fluid communication with expandable chamber 8 via said perforations as well as its open bottom at 6 a . The perforations can be effectively formed by using a tubular net with, for example 0.030″ to 0.100″ diameter strands forming a diamond shaped opening, see 6 in FIG. 2 a , and can be obtained from Nalle Plastics Inc. Austin, Tex. The tubular net can be made of polypropylene, polyester, Nylon, or polyethylene. It must possess at least three properties: 1) sufficient stiffness (either by rigidity of the material or thickness of the yarn) and structure to keep walls 18 and 19 (FIGS. 2 b , 2 c , 2 d ) of venous reservoir bag 1819 (FIG. 2 a ) away from screen 3 thereby maintaining chamber 7 ; 2) an opening to allow unhindered fluid communication between chamber 7 and expandable chamber 8 ; and 3 ) cause no undesired interaction with biological fluids. Tubular net 6 preferably extends vertically from the bottom of venous reservoir 1819 at its inlet to the top of said reservoir and can be attached to the external wall of air-venting tube 4 for support. The inlet to cylinder 6 , 6 a , may extend below screen 3 providing free fluid communication between inlet 1 and expandable chamber 8 . With this design, experiments similar to those described for the Cobe and Baxter bags result in a steady bubble count of 60 at bag volumes of 500 and 1000 ml.
[0104] [0104]FIG. 2 e illustrates the blood path of the present invention. Venous blood with some gas bubbles 23 enters the venous reservoir via inlet tube 1 . The inertial forces of the blood exiting outlet of tube 1 propel the blood and bubbles upward into first inlet chamber 2 . Chamber 2 is preferentially lined up within ± 15° of the vertical line. This essentially vertical position, unlike prior art devices, provides the least resistance for gas bubbles to rise up chamber 2 to air-venting tube 4 where they are evacuated by suction applied to the outlet of tube 4 , port 4 b.
[0105] As shown in FIG. 2 a , screen 3 extends to the top of venous reservoir 1819 where it is sealed to gas venting tube 4 . This seal prevents blood from exiting at the top where it may drag bubbles out of inlet chamber 2 into expandable chamber 8 . Should gas volume increase at tube 4 and displace blood volume at the top of chamber 2 , the gas could cross screen 3 and enter chamber 7 and chamber 8 . Because screen wall 3 may get wet again before all the gas at the top of chamber 8 is removed, that gas can be trapped. Purge tube 9 (see FIGS. 2 a and 2 e ) is provided to allow gas to be purged from chambers 7 and 8 . For that purpose, the topmost entry point of tube 9 into chamber 8 is the highest point in chamber 8 (e.g. point 8 a is higher than point 8 b ). Tube 9 extends from air-venting tube 4 into chamber 8 , said extension preferably having holes 9 a in its wall to provide better fluid communication with chamber 8 along the entire length of tube 9 . Holes 9 a allows air to enter tube 9 and be evacuated as described before. Other holes may be punched into tube 9 to allow air to be evacuated at any blood level. The smaller diameter of tube 9 and the location of its outlet at the top of venting tube 4 reduces the chance of blood flowing (with bubbles) from chamber 2 to chamber 8 via tube 9 . The extension of tube 9 into chamber 8 also forms two channels, shown as 9 aa in FIG. 2 cc , for air to travel along the tube upwards because the tube prohibits the opposite walls of the bag from making complete contact. Channels 9 aa increase in size with increasing outside diameter of air removal tube 9 and thicker/stiffer walls 18 and 19 of bag 1819 . FIG. 1 b and its associated view along 1 b - 1 b ′, FIG. 1 bb , illustrate how the present invention provides air channels. FIG. 1 a and its associated view along 1 a - 1 a ′, 1 aa illustrate how prior art shorter air removal tube (e.g. prior art U.S. Pat. No. 5,573,526 FIG. 1 tubes 18 and 20) lack such channels. Tube 9 extends downward into blood chamber 8 at least 40% but preferably over 50% of the height blood chamber 8 . As well known in the art, tube 9 can alternatively be sealed directly into chamber 8 and external to tube 4 . As shown, tube 9 is exposed to the same suction applied to air-venting tube 4 .
[0106] With the present invention because, air moves freely to the top of bag 1819 where it can be purged easily. It therefore should be obvious that the degree of suction applied and the blood volume removed in order to purge the gas should be significantly lower than with present devices. The smaller blood volume removed, the lower flow required to remove the gas and the larger ID of the purge line all contribute to significantly lower blood damage. This is especially true when stopcocks, which have very small ID (e.g., 0.062″ and sometimes less) and are used with present devices, are eliminated.
[0107] The user may not easily determine the presence of bubbles or the blood level in first inlet chamber 2 due to the opacity of the blood and/or screen 3 . Yet another innovation provides means to easily ascertain the presence of bubbles by increasing the ID of air-venting tube 4 to at least ¼″ but preferably ⅜″ or greater. Other venous reservoir bags have gas ports of ⅛″ ID or smaller, which presents a high resistance to gas and blood flow. The increased port diameter of the present invention increases the ease by which bubbles rise up tube 4 for two reasons. First, gas bubbles move up easier in a liquid filled tube having a diameter larger than the diameter of the bubbles. Second, a larger diameter tube accommodates larger bubbles with greater buoyancy, providing greater upward force on the bubbles relative to the capillary force within a liquid filled tube that inhibits their movement. Thus, by having an exhaust tube with a larger diameter, the user could pull blood up into tube 4 . Should air enter first inlet chamber 2 , it would travel up and replace the blood in tube 4 causing the visible blood level 4 d (see FIG. 2 a ) in tube 4 to drop, an indication that air entered the venous reservoir and must be removed. It should be understood that the process can be automated by incorporating level detector 10 radial to tube 4 , said detector 10 connected to a suction controller and/or alarm monitor via transmitter line 10 a . Monitor/controller 12 alarms the user to air entering tube 4 and/or starts the required suction applied to the outlet of tube 4 , 4 b , to remove said air and raise the liquid level. Once the level detector detects the rising liquid, it can stop the alarm and/or stop the suction used to remove the gas from the venous reservoir. Monitor/controller 12 can, for example, control the speed of the pump providing suction. Alternatively, it can open or close the tube providing suction (not shown) by a solenoid actuated tubing clamp. Also, as described in reference to one way valve 422 in reference to FIG. 4, preferably one-way valve 22 , placed just below outlet 4 b of tube 4 , prevents air from entering the reservoir if the reservoir empties and is exposed to the suction generated by arterial pump 1104 . Further, defoamer sponge 24 , preferably incorporating anti-foam A and placed below valve 22 , may be used to break up blood in the form of foam that reaches the inlet of valve 22 . Placement of defoamer 24 at the top of tube 4 provides the desirable defoaming action while limiting contact between the defoamer and the blood that rises to that level.
[0108] As shown in FIG. 2 a the large diameter of chamber 2 allows more time for the bubbles to rise to the top and causes less turbulence that could hinder the upward motion of the bubbles. Most of the blood preferably flows from chamber 2 to chamber 7 across screen 3 , thereby assuring the upward motion of the bubbles. This preference is enhanced by cylinder 6 maintaining screen 3 free of contact with venous reservoir walls 18 and 19 , see FIG. 2 c . Typically, if wall screen 3 forms a cylinder with a 1″ diameter, then for an 8″ high structure, its surface area is 25in2. This large effective area is available for blood flowing from inlet chamber 2 to expandable chamber 8 and is virtually independent of the blood volume in expandable chamber 8 . Annular space 7 formed by cylinder 6 and screen 3 and better seen in FIG. 2 c , serves to separate gas from the blood; any bubbles that may have crossed wall 3 can still be buoyed upward to the top of chamber 7 where they can be removed by tube 9 . The blood then flows from expandable chamber 8 to outlet port 5 . Should air enter chamber 8 , it can still float to the top of said chamber and be eliminated via tube 9 . FIG. 2 cc , which is an enlargement of the circled section shown in FIG. 2 c , illustrates how tube 9 forms air channels 9 aa , described in reference to FIGS. 1 b and 1 bb , thereby enhancing air removal by keeping walls 18 and 19 slightly apart along the length of tube 9 . Thus with this design, there are three chambers for air elimination: chambers 2 , 7 , and 8 .
[0109] A major reason a collapsible bag is used as a venous reservoir is to prevent air from being pumped out of the bag and into the patient should the venous reservoir empty. In present bags this is achieved by having the outlet port ( 5 in FIG. 2 a ) at the lowermost point of the bag. This can be incorporated into the present invention. Alternatively, the inlet of outlet tube 5 , 5 a , can be cut on a diagonal (nominal 35° to 65°) with its pointed end protruding into expandable chamber 8 and its low point in line with the periphery of the bag at 8 c , as shown in FIG. 2 a . Tube 5 should be made of relatively soft material (e.g. 55 Shore A) and have a relatively large ID/wall ratio (e.g. 0.5″/0.062″=8). Since a larger ID/wall ratio, as well as softer durometer wall, requires a lower pressure difference across the wall of the tube to collapse the tube, then the combination of higher ratio and lower durometer can be used to quantify the ease of said collapse, (ID/wall)/durometer. Thus, for the above example, (0.5″/0.062″)/(55)= 0.147. This number is significantly higher than that obtained for the outlet tube typically used at the outlet of present venous reservoirs (0.5″/0.093″)/(65)= 0.082. Since the ease of tube collapse is related to (ID/wall) 3 , (see my U.S. Pat. No. 5,215,450: Innovative Pumping System for Peristaltic Pumps), even a small change in that ratio causes a large change in ease of collapse. Thus, the softer tubing and/or high ID/wall ratio allows collapsing walls 18 and 19 of venous reservoir bag 1819 to gradually, rather than suddenly, impede the flow out of outlet tube 5 . Once empty of liquids, the present aspect of the invention provides a looser seal about the outlet as compared to standard bags. Thus, when inlet flow resumes, less volume is needed to open the outlet tube, thereby providing resumption of flow sooner than present venous reservoir bags.
[0110] An experiment was conducted to determine the negative pressure developed between the outlet of venous reservoir 1103 and the inlet of pump 1104 when pump 1104 (see FIG. 1) was pumping at 6.0 L/min out of venous reservoir 1103 and the venous flow into the venous reservoir was less than 6.0 L/min. The reservoir was emptied and its outlet collapsed. Also measured was the blood volume required in the venous reservoir to reopen the venous reservoir outlet. Once emptied, the outlet of the Cobe reservoir bag stayed closed until the volume in the bag increased to over 1,400 ml. During that time, the pump inlet pressure (measured in line 435 in FIG. 1) decreased to and remained at over −600 mmHg. Once the blood volume in the bag reached 1,400 ml, sufficient pressure was exerted to expand walls and release the collapsed outlet of the venous reservoir, thereby allowing resumption of blood flow from the venous reservoir to the pump inlet. A similar experiment with the Baxter bag required an increase in blood volume of 400 ml before the high negative pressure at the pump inlet (−580 mmHg) was relieved and the bag outlet opened up. With the present invention, only 350 ml were required to open the venous reservoir outlet and reestablish flow, and the maximum negative pressure was only −400 mmHg.
[0111] As shown in FIGS. 2 a , 2 b , 2 c , 2 d , layers 18 and 19 are heat sealed (e.g., by radio frequency welding) by a double margin along their upper and lower edges, by a relatively wide seal along their right edge and by a narrower seal along their left edge. Anchoring holes (eyelets) 27 , used to hang bag 1819 , can be formed by punching holes through, and along, the top and bottom of the heat sealed surface. The preferred configuration includes a hole on both sides of inlet tube 1 , outlet tube 5 , and air-venting tube 4 , and in the upper corner of the bag opposite tube 4 to facilitate secure attachment of the bag to the frame, see FIG. 2 a.
[0112] It should be understood that various sizes of the venous reservoir can be made without necessarily affecting their performance; for example, three popular sizes having capacities of 400, 1200, and 2000 ml are some of the possibilities. To simplify manufacturing and reduce costs of the hardware, all reservoir sizes can have the same footprint so each size can utilize the same frame. Here, smaller capacity reservoirs have a smaller bag portion and larger peripheral area (FIG. 3). Anchoring holes 21 a , 21 b , 21 c , 21 d , 21 e , 21 f , and 21 g used to attach each bag to the frame can be accommodated by corresponding adjustable supporting pins in the frame, for example, as well known in the art.
[0113] [0113]FIGS. 7 a , 7 b , and 7 c illustrate another preferred embodiment of the present invention. Here, rigid cylinder 72 replaces perforated cylinder 6 , shown in FIG. 2 a , to provide annular space 77 as well as to serve as part of the wall of venous reservoir 772 . Pliable venous reservoir walls 18 and 19 are sealed to rigid cylinder 72 on both sides of longitudinal slot 72 a , said slot better seen in FIG. 7 b —(a cross sectional view of cylinder 72 along lines 25 and 25 ′ in FIG. 7 a ) and 7 c (a cross sectional view of cylinder 72 along lines 272 and 272 ′ in FIG. 7 a ), providing fluid communication between annular space 77 and expandable outlet chamber 8 . To reduce stasis and provide smooth blood flow, the incline at the bottom of the rigid cylinder 72 , 72 d , matches the bottom incline of chamber 8 , 8 d . Cylinder 72 (FIG. 7 b ) preferentially has longitudinal lips 72 b and 72 c along both sides of slot 72 a , said lips tapering and thinning as they extend outward. These lips serve to seal venous reservoir walls 18 and 19 about slot 72 a (e.g., by radio frequency welding) as well as to form a smooth blood flow path from annular space 77 to expandable chamber 8 . It should be obvious that cylinder 72 preferentially is made of biocompatible, clear, rigid thermoplastic that can be easily sealed to venous reservoir walls 18 and 19 . A good choice would be rigid PVC. It should be obvious that screen 3 , air-venting tube 4 , outlet tube 5 , and expandable chamber 8 formed by walls 18 and 19 serve the same purpose described for the venous reservoir embodiment shown in FIG. 2 a.
[0114] [0114]FIG. 7 d , which is an enlargement of the circled section shown in FIG. 7 a , illustrates another preferred embodiment providing a fluid path between chamber 8 and air-venting tube 74 that allows air removal present in annular space 77 and expandable chamber 8 . Here, cylindrical air-venting tube 74 has a notch 74 h , at its bottom, also seen in FIG. 7 e , which is a view of FIG. 7 d taken along cross section 26 - 26 ′ and FIG. 7 f , which is a view of FIG. 7 e taken along cross section 27 - 27 ′. As shown, the height of notch 74 h extends beyond the top of screen cage 26 , 26 b . The bottom of notch 74 h extends onto the highest point of chamber 8 , 8 a , which also preferentially corresponds to the highest point of screen 3 . Thus, notch 74 h provides a fluid communication, see arrow 84 in FIG. 7 d , between air-venting tube 74 and chamber 8 . Notch 74 h replaces the function of tube 9 shown in FIG. 2 a.
[0115] As described so far, air removal is accomplished as it is by current techniques: suction pump 1114 (see FIG. 1) typically with ¼″ ID tubing is used to remove the gas from the top of the venous reservoir. This arrangement works but requires constant vigilance and intervention by the user to control air removal. Another innovative feature of the present invention is that air can be automatically eliminated from the reservoir with little or no user intervention required. Three preferable designs for the air purge port use a hydrophobic membrane, a floating ball, or controlled suction. All three methods allow air to be removed with very little, or no blood loss. The user would have the option to connect wall suction or one of the sucker pumps as the suction source for the air purge port, preferably having some regulating means to adjust/limit the degree of suction.
[0116] [0116]FIG. 4 illustrates one preferred embodiment that achieves a large membrane area at the top of the venous reservoir. The design, with a cross section in the shape of an inverted “V” or “U”, achieves a large area and provides an inclined surface. Membrane 45 has an inclined surface that facilitates clearing of any blood film off the surface of the membrane. Gravity and wicking should encourage any such film to “peel” off the surface into the blood pool, thereby maintaining the membrane clearer and the gas transfer rate up. Membrane support 425 can be incorporated as the top of a semi-rigid PVC frame formed into a protective “roof”. The inside surface of the roof-contacting membrane incorporates ridges 425 a , which are in unimpeded fluid communication with air-venting tube 44 . Ridges 425 a also support membrane 45 and prevent it from deforming due to pressure differences across its wall. The membrane should meet a high gas flow elimination requirement (at least 1 L/min at −100 mmHg). Membranes preferably are made of PTFE (e.g. Durapel™ from Millipore, Bedford, Mass.) or polypropylene (e.g. Zintex™ from W L Gore, Elkton, Md.), preferably having a pore size between 0.45μ and 1.0μ. The small pore provides a sterile barrier.
[0117] The membrane is used to automatically remove air 423 that may accumulate at the top of the venous reservoir by applying suction (from the hospital supply) to air-venting tube 44 . Hydrophobic microporous membrane 45 prevents the loss of blood 46 from the venous reservoir. One-way valve 422 may be placed at the outlet of air-venting tube 44 to prevent air from entering the reservoir if the reservoir empties and is exposed to the suction generated by arterial pump 1104 . Membrane 45 has sufficient surface area to allow the removal of the expected volume of air entering the venous reservoir. Studies have shown that membranes that clear air from water can function almost indefinitely (many days) and high suction can be applied without reducing gas transfer rate over time. (However, over time, when the membrane is exposed to blood, especially when high suction is applied, a film overlays the membrane, resulting in a significant increase in resistance to gas flow. When applying lower suction (preferably between −50 and 200 mmHg), the transfer rate of gas across the membrane does not decrease as fast as with high suction (possibly due to less plasma penetration into the pores or lower holding force of the film). Therefore, removing air from blood requires a membrane with a larger area. The larger area compensates for the lower suction used to extend the life of the membrane and the lower transfer rates seen with blood as compared to water.
[0118] Another preferred embodiment, shown in FIGS. 5 a and 5 b , utilizes a tubular microporous membrane 55 in fluid communication with purge port 54 , said tubular membrane internally supported and sealed to perforated rigid housing 525 . Perforated rigid housing 525 allows gas to cross membrane 55 and enter chamber 59 unimpeded. Housing 525 is sealed at the bottom along 525 a . Chamber 59 , formed by housing 525 , is in fluid communication with purge port 54 . Annular space 57 is formed by circular membrane 55 and air-venting tube 4 . Air-venting tube 4 could be in fluid communication with first inlet chamber 2 shown in FIG. 2 a and preferably located on top of chamber 2 . Normally annular space 57 is filled with blood. Should air 523 enter line 1 (see FIG. 2 a ), it would rise up chamber 2 , as shown in FIG. 2 f , enter annular space 57 (FIGS. 5 a and 5 b ), across membrane 55 into chamber 59 (FIG. 5 a ), across port 522 a of one-way valve 522 , and be purged via purge port 54 . Applying suction to purge port 54 facilitates air removal by increasing the pressure difference across membrane 55 . As with the “roof” design referenced in FIG. 4, vertical placement of the tubular membrane 55 facilitates “peeling” of the blood layer of the surface of the membrane, thereby improving long-term gas transfer.
[0119] The second preferred method to remove air utilizes a floating ball, which allows air but not blood to be removed through the purge port. As shown in FIG. 6 a , housing 64 a forms chamber 67 that allows air bubbles to rise unhindered as previously described for chamber 2 and tube 4 in reference to FIG. 2 a . Housing 64 a incorporates ball cage 68 , floating ball 61 and unidirectional valve 622 . Port 622 a of unidirectional valve 622 providing fluid communication between chamber 67 and gas exhaust port 64 , is open as long as air 623 is present in chamber 67 . When most of the air has been eliminated, the rising fluid level brings ball 61 to the top of chamber 67 , effectively closing port 622 a . In this position, any further withdrawal of fluid from the venous reservoir is prevented. When more air enters the reservoir, the blood level falls, ball 61 drops, and the applied suction removes air 623 . Suction may be provided by a wall source or a suction pump, but preferably is controlled for the purpose described below.
[0120] There are two forces maintaining ball 61 up against port 622 a keeping said port closed: the buoyancy of the ball and the suction force applied at the gas port (Fs). Fs= (πd2S/4, where d is the inside diameter of air port 622 a in contact with ball 61 , and S is the negative pressure (suction) applied via air-venting tube 64 against said ball. The upward force, Fs, must be less than the weight of the ball so that when the blood level drops, the weight of the ball overcomes Fs and the ball falls. Cage 68 , in general has a larger ID than the OD of ball 61 , see 68 a in FIG. 6 a and 6 c , where FIG. 6 c is a line drawing illustrating another view of the ball cage used in FIG. 6 a taken along line 24 - 24 ′. Cage 68 aligns the ball with air port 622 a . The bottom of cage 68 narrows down to an ID smaller than the OD of ball 61 , see 68 b FIGS. 6 a and 6 b , where FIG. 6 b is a line drawing illustrating another view of the bottom of the ball cage used in FIG. 6 a taken along line 23 - 23 ′. The smaller ID 68 b serves to retain ball 61 within its chamber 67 and prevents it from falling into the venous reservoir. For this design, for example, ball 61 may be a 1″ solid polypropylene ball (specific gravity sp= 0.90), or a hollow ball (where sp is adjustable). Air port seal 622 a could, for example, be made of soft silicone and the ID of the air port may be {fraction (1/32)}″. To assure a good seal, the surface of the ball should have a fine finish, preferably with a tolerance of 0.001″ or better. The applied suction should be low to assure that ball 61 does not “stick” to gas port 622 a in the closed position, and to minimize blood damage. For example, a pressure of −30 mmHg can be applied to remove the air. This degree of suction is sufficient to withdraw the air and maintain the liquid column within first and second inlet chambers 2 and 7 when flexible chamber 8 is less than full, see FIG. 2 a . To prevent excess suction (e.g. over −150 mmHg) from being applied, the line between air venting tube 64 and the suction source can include a t-connector 64 c with a suction regulating valve 632 attached at the inlet of side port 64 c (FIG. 6 d ). Such valves are commercially available at various cracking pressures and are currently used for IV infusion sets (e.g., NP Medical, Clinton, Mass., cost < $0.25). As well known in the art, a blood trap (not shown) may be incorporated so any blood that may enter the line would not progress to the suction source, and, in fact, excess lost may be returned to the patient. Alternatively, the air-venting tube 64 may be connected at 64 b to Cardiotomy reservoir 1115 (see FIG. 1), to which suction is applied. Thus, any blood that may pass the ball valve system would go back to the patient via cardiotomy 1115 . Safety is paramount. Therefore, side port 64 d , having for example a female Luer, in fluid communication with first inlet chamber (e.g., via chamber 67 in FIG. 6 d ), is placed prior to either the ball or the membrane. Port 64 d provides the user means to eliminate incoming air in a fashion similar to that of present devices, in case the membrane or ball malfunctions.
[0121] Another preferred method to remove air is a variation of the second method but without the floating ball valve combination. As shown in FIG. 11, the top of first inlet chamber 112 of venous reservoir 113 is extended into “chimney” 114 that serves to vent air and is connected to cardiotomy reservoir 15 , to which suction is applied at 15 a . The degree of suction should be sufficient to elevate the blood level into chimney 114 , even when the expandable chamber 118 is less than full. Thus, any air 623 entering inlet tube 111 would float to the top of first inlet chamber 112 and enter chimney 114 . The air would then displace the liquid in chimney- 114 , coalesce with air volume 114 a that interfaces between the blood in chimney 114 and outlet 114 b of chimney 114 , and the additional suction would pull the liquid up the chimney to its original level. This system requires that chimney 114 have an ID that facilitates upward movement of air bubbles, even large ones. The length of the chimney needs to be at least equal to the level of the expected liquid when suction is applied and expandable chamber 118 is full. Beyond that height, the outlet of chimney 114 b can be connected via ¼″ ID tube- 116 to the cardiotomy reservoir. Air space 114 a below chimney outlet 114 b assures that the blood does not enter smaller diameter tube 116 . Suction, applied at 15 a , can be provided by the wall source, or suction pump 1114 (FIG. 1) connected to cardiotomy reservoir 15 , said suction regulated to appropriate levels as well known in the art.
[0122] As described in the Description of the Prior Art, improved venous drainage can be achieved by applying some negative pressure on the venous blood. Another aspect of the invention allows the user to apply suction with a collapsible reservoir. FIGS. 8 a , 8 b , and 8 c illustrate venous reservoir 772 , previously described in reference to FIGS. 7 a , 7 b , and 7 c , placed in generally elliptical, clear rigid, housing 88 . Housing 88 is open both at its bottom, defined by border 88 a , and at its top, defined by border 88 b , said borders having sealing gaskets 82 and 81 respectively. Disposable venous reservoir 772 incorporates rigid bottom cap 89 , said cap having lip 89 a with its inside diameter matching outside diameter of housing 88 to form a seal along gasket 82 . Bottom cap 89 also is sealed to inlet tube 1 at 89 a and outlet tube 5 at 89 b . A similar arrangement is made at the top of venous reservoir 772 where rigid disk 72 d is sealed along top gasket 81 of housing 88 . Thus, the user would slip chimney 74 of disposable venous reservoir 772 into the bottom of housing 88 , push it up and insert it through opening 88 d at the top of housing 88 . When lined up, rigid disk 72 d is pushed against gasket 81 and bottom cap 89 seals against gasket 82 . The bottom and top seals are reinforced and maintained by cap 89 held against housing 88 by snaps 88 e , 88 f , 88 g and 88 h that lock onto ridge 89 d of cap 89 . At the end of the case, snaps 88 e , 88 f , 88 g and 88 h , each of which is hinged at its midpoint (e.g. see 88 i of hinge 88 f ) are pushed inward, as shown by respective arrows 812 and 811 for snaps 88 f and 88 e , causing the bottom of said snaps (e.g. 88 j shown in FIG. 8 b ) to move outward, see for example 88 e ′ in FIG. 8 b , releasing said snaps from locking ridge 89 c and 89 j thereby allowing the removal of venous reservoir 772 .
[0123] Chamber 87 , formed between venous reservoir 772 and rigid housing 88 , communicates via port 88 c with vacuum regulator 813 , said regulator used to adjust the degree of suction applied to chamber 87 using knob 813 b . Gauge 813 a can be used to indicate the applied suction. As described before, venous reservoir 772 responds to pressure differences across its walls 18 and 19 (FIG. 8 b ). Thus, diminished blood flow from patient 1102 , see FIG. 1, due to increased resistance to flow (e.g. smaller cannula) can be increased by applying suction to chamber 87 . The suction “pulls” walls 18 and 19 outward thereby pulling the blood into the blood chamber. For safety, housing 88 is sized to assure that venous reservoir 772 cannot over-expand beyond defined limits, said limits defined as a volume in blood chamber 8 that would result in a pressure measured at the top of blood chamber 8 being greater than 10 mmHg. Thus, as chamber 8 of venous reservoir 772 expands, walls 18 and 19 move towards the walls of housing 88 until they make contact, see 18 a and 19 a in FIG. 8 b . Once contact is made, further outward motion of walls 18 and 19 is limited by rigid housing 88 . To facilitate the use of the system, housing 88 incorporates pole clamp 810 , said clamp provides a simple connection of said housing to a heart-lung machine. It should be understood that a rigid component, such as rigid cylinder 72 , incorporating into venous reservoir 772 , see FIGS. 7 a and 8 a , is required to facilitate both the introduction of said venous reservoir 772 into housing 88 , and the sealing of said reservoir against gasket 81 , shown in FIG. 8 a . To enhance the ability of the user to see the blood in venous reservoir 772 , light 80 , shown in FIG. 8 b , can be added to the back of housing 88 .
[0124] [0124]FIG. 9 a illustrates another embodiment for a nondisposable housing designed to allow venous augmentation with a collapsible venous reservoir. The concept is similar to that shown in FIG. 8 a except that the seals and closure mechanism are different. Here, venous reservoir 772 is placed in container 98 , said container having a back plate and four walls forming first open box, 98 e , which accommodates venous reservoir 772 . Container 98 has a matching door 99 that is hinged at 99 f by pin 98 f to container 98 and is shown in FIG. 9 b and 9 c . Door 99 has a front plate and four walls forming second box 99 e that also accommodates venous reservoir 772 . To operate, venous reservoir 772 is placed in first box 98 e and door 99 is closed thereby sealing said venous reservoir, along gasket 92 , within space 909 formed by first box 98 e and second box 99 e . Port 98 c in box 98 in fluid communication with the formed sealed space can be connected to a regulated vacuum source, much like the one described in reference to port 88 c shown in FIG. 8 a and 8 b . It should be understood that for proper function, the venous reservoir is free to expand within the sealed space 909 thus formed. For free expansion of venous reservoir 772 , seals of the venous reservoir within container 98 and door 99 are achieved at inlet tube 1 , between 92 a and 99 a (FIG. 9 b ), air-venting tube 4 , at 92 b and 99 b (FIG. 9 c ), and along outlet tube 5 , at 92 c and 99 c (FIG. 9 b ). When door 99 is closed, the ID of indentations 92 a and 99 a form a tight seal about the OD of inlet tube 1 . Similarly, indentations 92 c and 99 c form a tight seal about the outside of outlet tube 5 (FIG. 9 b ), and indentations 92 b and 99 b form a tight seal about the outside of air-venting tube 4 (FIG. 9 c ). To assure a tight seal, relievable latches 99 d and 99 f lock unto ridge 98 d , see FIGS. 9 a , 9 b and 9 c.
[0125] To improve the seal along the inlet, outlet and gas exhaust port, each of said tubes preferably incorporates a secondary structure, see sealing structure 1 a in FIG. 9 d for inlet tube 1 . Sealing structure la has a flexible wall forming a wings 1 aa and 1 ab on the side of tube 1 , see FIGS. 9 e and 9 d . The wings are tapered, being thickest at the base and thinnest at the tips, see FIG. 9 d . For effective sealing, gasket 92 accommodates wing 1 aa at thinner section 92 aa and wing 1 ab at thinner section 92 ab , said accommodation providing a seal between container 98 and door 99 along gasket 92 . Gasket 92 , for example, can be made of a polyurethane sponge, which conform to the shape of said wings, see FIG. 9 d . Wing 1 a preferably is bonded or welded to tube 1 and is therefore disposed when venous reservoir 772 is disposed. Similar designs can be incorporated into air-venting tube 4 and outlet tube 5 .
[0126] [0126]FIG. 9 f illustrates another preferred embodiment for sealing inlet tube 1 between housing 98 and door 99 . Here, gasket 93 is attached to door 99 , said gasket having indentation 93 a to seal about the inlet tube 1 when door 99 is closed against housing 98 . This design also incorporates deeper indentation 98 a ′ in the housing, with a closed circumference greater than 225° and an inside diameter that is less than the OD of inlet tube 1 . When the venous reservoir is loaded into the housing, flexible inlet tube 1 is pushed into indention 98 a ′ where it is retained within said indentation by a pressure fit. This allows the user to load air-venting tube 4 and outlet tube 5 . It should be obvious that purge port should be loaded first thereby having the venous reservoir hanging from the top while the other two tubes are lined up before door 99 is closed.
[0127] [0127]FIGS. 12 a , 12 b , and 12 c illustrate another preferred embodiment that is identical to that described in FIGS. 8 a , 8 b and 8 c with two major exceptions. Gas removal port 74 and its associated seal 72 d shown in FIG. 8 a are replaced by gas removal tube 124 shown in FIG. 12 a . Tube 124 bends and extends to the bottom of bag 772 , see FIG. 12 a , and exits in the same direction as inlet tube 1 and outlet tube 5 thereby eliminating the need for top seal 72 d . Bag 772 in FIG. 8 a has its gas removal port 74 extending straight up with its outlet ending above bag 772 and pointing opposite to said inlet and outlet tubing. Having all three tubes of bag 772 extend beyond blood chamber 8 and in one direction and exit along the same plane allows all three tubes to be threaded, preferably during manufacturing, through bottom supporting plate, or cover 89 . Thus, as shown in FIGS. 12 a , 12 b , and 12 c , inlet tube 1 is threaded through cover 89 and is sealed at 89 a , outlet tube 5 is threaded through cover 89 and is sealed at 89 b , and gas removal 124 is threaded through cover 89 and is sealed at 89 e . Having all tubes extend beyond blood chamber sealed within single plate 89 significantly simplifies sealing bag 772 in housing 88 ; it allows sealing along a single plane of cover 89 against single O-ring 82 of housing 88 . It should be obvious that bottom plate 89 could incorporate perfusion connectors as described in reference to supporting plate 1389 in FIG. 13 f.
[0128] The other innovative design, shown in FIGS. 12 a and 12 b but not in FIG. 8 a or 8 b , incorporates an opening 88 k in front wall 881 of housing 88 allowing the user to reach bag 772 without removing the bag from its housing. Reaching bag 772 was the purpose of the external means provided by aforementioned U.S. Pat. No. '045 to massage the SSR with vibrator 36 . The present invention incorporates removable sealing means to front wall 881 of housing 88 , such as door 1288 , whose outside outline is shown as a dashed line in FIGS. 12 a and 12 b . Door 1288 in its neutral state is supported by hinge 1202 hanging at on front wall 881 . The outside perimeter of opening 88 k , shown as a dotted line in FIGS. 12 a and 12 b , of front wall 881 is surrounded by flexible seal 83 . Seal 83 assures that when door 1288 is closed, it seals opening 88 k from atmospheric pressure. To open door 1288 , the user would release any negative pressure in closed chamber 87 then open door 1288 by pulling handle 1288 a shown in FIG. 12 b . Closure of door 1288 against seal 83 can be facilitated by tilting front wall 881 either by design, or by tilting entire housing 88 , thereby allowing gravity to hold door 1288 against wall 881 . Design correctly, using gravity to push door 1288 against seal 83 can eliminate clamps that may be necessary otherwise. Gravity closing would allow hinged door 1288 , if it were not secured to rigid housing 88 , to also serve as a pressure relief valve should vacuum fail. As well known in the art of doors, mechanisms to maintain door 1288 open, or even temporarily remove the door, can be easily incorporated in the usual manner. To assure that vacuum is not applied accidentally, door closure is preferably designed such a complete seal occurs only when vacuum is applied and the user temporarily pushes against the door. The seal formed by the initial pushing force provided by the user, is then maintained once vacuum build within chamber 87 .
[0129] [0129]FIGS. 13 a and 13 b illustrate another preferred embodiment of a soft shell reservoir with the very innovative features: top loading of the reservoir into its holder and easy secure sealing of the bag for vacuum assist. Venous bag 1366 is preferably made by RF welding polyvinylchloride or polyurethane film having thickness of 0.015 to 0.020″ along perimeter 1310 , to form expandable chamber 138 with walls 1318 and 1319 . Folded screen 1303 (e.g. Medifab from Tetko Inc. Depew N.Y., a polyester mesh with a pore size of 105μ and a 52% opening) is placed with fold (preferably not creased) 1303 a facing downward and sealed along its vertical sides by welding its side edges between walls 1318 and 1319 along periphery 1310 . Screen fold 1303 a defining the bottom of screen 1303 , preferably is placed at least ½″ from the bottom of blood chamber 138 . The top free edges 1303 b and 1303 c of screen 1303 , shown in FIG. 13 b , face upward and, at least partially, are not sealed along the top periphery 1310 a and therefore an opening into pouch formed by fold 1303 a and the two sealed sides of screen 1303 . The screen placement defines four sections, within expandable chamber 138 . Bottom or outlet section 138 a defined as the section of blood chamber between screen fold 1303 a and blood outlet tube 1305 . Mid or inlet section 138 b defined as the section of blood chamber between the top of screen 1303 and its fold 1303 a . In inlet section 138 b , blood is completely surrounded by screen 1303 . Top, or bubble removal section 138 c , is defined as the section of blood chamber 138 above inlet section 138 b , between the top of screen 1303 and sealed top periphery 1310 a . Bubble removal section 138 c has no screen. The “in-between” section, 138 d , is the section between walls 1318 and 1319 and screen 1303 . The four sections are in fluid communication with each other.
[0130] As shown, four tubes enter bag 1366 . Inlet tube 1301 and infusion tube 1306 are in direct fluid communication with inlet section 138 b . Air removal tube 1304 is in direct fluid communication with inlet section 138 b and air removal section 138 c . Outlet tube 1305 is in direct fluid communication with outlet section 138 a . Tubes 1301 , 1306 and 1304 enter from the top of blood chamber 138 , are sealed along top perimeter of sealed section 1310 a , pass through air removal section 138 c , two screen edges 1303 b and 1303 c of screen 1303 and into inlet section 138 b . All tubes, except outlet tube 1305 , preferably have holes along their length positioned in inlet section 138 b . Gas removal tube 1304 also has holes, 1304 aa , along its length stationed in both air removal section 138 c and inlet section 138 b.
[0131] Inlet tube 1301 preferably enters blood chamber 138 at a top corner of blood chamber 138 and extends to the bottom of inlet section 138 b , preferably diagonally to a bottom corner opposite said top corner. Blood enters inlet tube 1301 at its inlet end 1301 a in a downward direction, said inlet being above said blood chamber 138 and changes direction as it flows within curved inlet tube 1301 . Outlet end 1301 d of inlet tube 1301 is preferably sealed, forcing blood out exiting holes 1301 b . Exit holes 1301 b are preferably located only along the top length of tube 1301 situated in inlet section 138 b that faces air removal section 138 c , see FIG. 13 a . Thus, venous blood, entering inlet tube 1301 in a downward flow at inlet 1301 a , is diverted from a downward flow to a more horizontal flow and then in an upward direction through exit holes 1301 b . The diversion in flow occurs within inlet tube 1301 distal to inlet 1301 a . The upward blood flow pushes bubbles towards air removal section 138 c . A venous bag for an adult patient would preferably have inlet tube 1301 , said tube preferably having an ID of 0.5″ and exit holes 1301 b with a diameter of 0.5″ or larger.
[0132] Blood entering inlet section 138 b preferentially flows to outlet section 138 a via screen 1303 , said screen, once wet, allowing liquid through but retaining bubbles within inlet section 138 b . Bubbles are pushed upwards by the direction of the blood exiting holes 1301 b and by buoyancy. Bubbles rise towards air removal section 138 c and then to access holes 1304 a of air removal tube 1304 , where they are removed, is obstructed when wall 1318 collapses against its opposing wall, as happens with prior art SSR when blood volume is low. With the present SSR, as described in reference to FIG. 2 cc and FIGS. 1 b and 1 bb , channels are formed along the outside diameter of tubes 1301 , 1306 , and 1304 providing a pathway for bubbles to move upward to air removal section 138 c and on to access holes 1304 a of air removal tube 1304 . Air removal efficiency is further improved by extending tube 1304 , and preferably also infusion tube 1306 , from the top of blood chamber 138 downward into inlet section 138 b , at least 50% of the vertical distance between the top and the bottom of inlet section 138 b but preferably over 80% of the height inlet chamber 138 b . If no screen is used, then said extension downward from the top of blood chamber 138 is at least 50% of the height of blood chamber 138 .
[0133] As shown in FIG. 13 a , air removal tube 1304 preferably extends in a diagonal direction within blood chamber 138 b thereby providing a longer air removal channel than that possible with said tube extending only vertically. Tube 1306 serving as an infusion line, may be closed at its top and just serve as a spacer that provides air bubbles a pathway to air removal section 138 c when low blood volume tends to collapse the blood chamber. In fact additional intermediate gas purge tubes (not shown), similar to tubes 1304 and 1306 may be incorporated in a similar manner to provide more numerous air removal channels. Having air channels from the bottom of the screen to the air removal section, not only eliminates the front plate of prior art venous reservoir, but also allows chamber 138 of bag 1366 to take its natural tear drop shape, much like that shown in FIG. 12 b . The teardrop shape provides a larger area of the screen (the bottom) for blood flow unhindered by contact with the walls of the bag.
[0134] To assure that air bubbles can travel along the entire horizontal length of air removal section 138 c towards air removal tube 1304 , spacer 138 cc may be placed along the top of blood chamber 138 . Spacer 138 cc prevents the flexible wall forming blood chamber 138 from completely collapsing against its opposing wall when the blood chamber is partially empty. As with the aforementioned air channels provided by tube 1304 , preventing said complete collapse increases the efficiency of gas from the top of blood chamber 138 .
[0135] Another innovative design feature requires that the open ends of the all tubes of venous reservoir 1366 be above blood chamber 138 . Inlet tube 1301 , gas removal tube 1304 and infusion tube 1306 enter blood chamber 138 from its top. Outlet tube 1305 exits outlet blood chamber 138 a in a direction that facilitates outlet flow to exit in an upward direction. For example, as shown in FIG. 13 a , tube 1305 exits outlet pocket 138 aa , the lowest portion of outlet 138 a , in a horizontal direction thereby requiring only 90° turn for changing the normally downward outlet flow to the desirable upward flow. Here the venous reservoir also incorporates supporting plate 1389 having a first and second planar surfaces, with said first planar surface facing blood chamber 138 . The tubes of venous reservoir: inlet tube 1301 at 1389 a , outlet tube 1305 at 1389 b , gas removal tube 1304 at 1389 c , and infusion tube 1306 at 1389 d can be threaded through, solvent bonded and sealed during manufacturing to supporting plate 1389 .: (inlet tube 1301 at 1389 a , outlet tube 1305 at 1389 b , gas removal tube 1304 at 1389 c , and infusion tube 1306 at 1389 d .) Supporting plate 1389 can serve to support bag 1366 by dropping it into holder 1388 , as is done with prior art hard shell reservoir (e.g. Baxter holder p/n HSRH for hard shell reservoir p/n HSR4000). For this purpose, the perimeter of supporting plate 1389 is preferably larger than the perimeter of venous reservoir 1366 .
[0136] Inlet 1305 a of outlet tube 1305 tube may also be designed to prevent pocket 138 aa , shown in FIG. 13 a , from prematurely collapsing (i.e. while there is still blood in outlet chamber 138 a ) and uncollapsing once blood returns to outlet chamber 138 a . This is achieved by having the inlet of tube 1305 cut longitudinal to form a scoop-shape whose walls provide the resilience to maintain the walls of bag 1366 of section 138 aa apart from each other. A similar design was described in reference the inlet 5 a of outlet tube 5 shown in FIG. 2 a.
[0137] Another advantage of having all the tubes for the SSR entering from its top is that the bottom of the bag is unhindered by tubing and can be placed lower on to the floor thereby allowing greater gravity drainage.
[0138] It should be obvious that other designs of SSR 772 shown in FIG. 13 a can be made without compromising the spirit of the present invention. For example, FIG. 13 d is a line drawing of the bottom part of another preferred embodiment of a SSR, SSR 1362 . FIG. 13 dd is a line drawing of a cross section taken of FIG. 13 d along line 133 - 133 ′. SSR 1362 is identical to SSR 1366 shown in FIGS. 13 a and 13 b except its outlet section 1368 a is shaped as a funnel and its outlet tube 1365 enters said outlet section through back wall 1362 a via an angled connection. Here, as for outlet 138 a of bag 1366 , outlet tube 1365 exits outlet section 1368 a at lowest point, pocket 1368 aa . The angled connection can be made utilizing, for example, a Halkey-Roberts semi rigid connector #727AC (St. Petersburg, Fla.) RF welded to wall 1362 a and then connecting outlet tube 1365 to said connector. This design with an angle connector eliminates the need for outlet tube 1365 to be bent, as is the case for the design of outlet tube 1305 shown in FIG. 13 a . Though not illustrated, it is also possible to have outlet tube 1305 contained within blood chamber 138 and exiting at the top of bag 1366 .
[0139] [0139]FIG. 13 e is a line drawing of the bottom part of another preferred embodiment of a SSR, SSR 1372 . FIG. 13 ee is a line drawing of a cross section taken of FIG. 13 e along line 134 - 134 ′. SSR 1372 is identical to SSR 1366 shown in FIGS. 13 a and 13 b except its outlet tube 1375 enters its outlet section 1378 a through back wall 1372 a via an angled connection. Here, as for outlet 138 a of bag 1366 , outlet tube 1375 exits outlet section 1378 a at lowest point, pocket 1378 aa . The angled connection can be made utilizing, for example, a Halkey-Roberts semi rigid connector #727AC (St. Petersburg, Fla.) RF welded to wall 1372 a and then connecting outlet tube 1375 to said connector. This design with a semi rigid angle connector eliminates the need for outlet tube 1375 to be bent, as is the case for the design of outlet tube 1305 shown in FIG. 13 a.?
[0140] [0140]FIGS. 13 a , and 13 b also illustrate a line drawing of one preferred embodiment of a SSR holder that in combination with supporting plate 1389 of venous bag 1366 can form a closed housing that can be used for VAVD. Container 1388 can, in one embodiment, consist of continuous vertical walls (e.g. an extruded ellipsoid tube), a bottom and open top 1388 f forming an internal chamber having an effective internal diameter (e.g. for an ellipsoid the effective diameter being a function of the major and minor diameters.) Open top 1388 f preferably has a smaller opening than that of container 1388 , said opening sized to at least allow venous reservoir 1366 with its blood chamber 138 empty, to be dropped into container 1388 . The internal diameter of container 1388 is sized to prevent blood chamber 138 from over extending beyond aforementioned desirable limits. The perimeter of cover 1389 preferably is larger than opening 1388 f so as to close said opening 1388 f of container 1388 and form sealed chamber 1309 .
[0141] When positioned properly, supporting plate, or cover, 1389 closes said opening 1388 f forming housing 1309 . In one embodiment, cover 1389 preferably has two protrusions along its perimeter, 1389 e and 1389 f , said protrusions forming a channel between accepting open perimeter 1388 a of container 1388 . This combination lines up cover 1389 and container 1388 , provides a better seal, and hinders cover 1389 from sliding off container 1388 .
[0142] Rim 1388 a along the open perimeter of housing 1388 may incorporate sealing gasket 1382 against which cover 1389 can seal when vacuum is applied to chamber 1309 . When regulated vacuum is applied, via port 1308 shown in FIG. 13 b , SSR 1366 can be used to enhance venous drainage, as described in aforementioned VAVD. For VAVD, the cross section of container 1388 is preferably ellipsoid, a shape that accommodates the general shape of SSR 1366 and provides mechanical strength. It also serves to line up top of bag 1366 with its supported bottom, as well as preventing cover 1389 from rotating and thereby preventing the bag from twisting. Twisting along the vertical axis is also minimized by guides 1388 c and 1388 b extending from the bottom of container 1388 , accepting bag 1366 . Preferably, guides 1388 b and 1388 c support bag 1366 via outlet tube 1305 , which is stiffer than pliable wall 1319 and 1318 . Container 1388 preferably should be made from crystal clear, rigid, scratch resistance, tough material such as polycarbonate that can withstand an internal pressure of at least −250 mmHg. Since cover 1389 is disposable, it can be made from less expensive material, such as polyvinyl chloride, and need not be clear or scratch resistance. Cover 1389 required the physical strength to withstand the expected pressure differences across its wall when used for VAVD, preferably supporting a minimum internal pressure of −200 mmHg. Structures such as ribs 1389 f , shown in FIG. 13 a , can be used to reinforce cover 1389 . Reducing opening 1388 f by extending 1388 g shown in FIG. 13 b , to “just” allow loading of venous reservoir, reduces the area of cover 1389 that is exposed to vacuum and therefore reduces its required strength.
[0143] The top loaded SSR 1366 , compared to the bottom loaded design shown in FIG. 8 b , has significant advantages. SSR 1366 can be easily placed in the housing with one hand. Once placed, it stays in the holder/housing without clamps (e.g. 88 g and 88 h in FIG. 8 a ). With top loading/support, the weight (gravity) of the blood in bag 1366 pulls down cover 1389 against seal 1382 rather than pulling away, thereby using gravity, at least partially, to initiate a seal between cover 1389 and container 1388 . Also, the support on top and the weight (blood volume) on the bottom tend to “straightens out” bag 1366 . Top loading also provides a single flat plane to seal the bag and its associated tubing within housing 1388 . This feature is extremely important to assuring simplicity, reliability, and cost effectiveness. Making one of the walls of the of the housing a disposable rather than the entire housing as shown in FIG. 9 of PCT '16893, reduces costs significantly. Further reduction in costs is achieved by making the disposable wall, a wall with a small area (e.g. top or bottom wall). A smaller area requires lower force to support the same pressure difference and therefore allows use of thinner cover.
[0144] Top loaded SSR has two additional advantages. First, when placing venous reservoir 1366 into its holder by hanging it by it supporting plate 1389 , blood in blood chamber 138 tends to settle at the bottom of blood chamber 138 lowering the center of gravity towards the bottom of the venous reservoir and far below, supporting plate 1389 . Thus, supported at its top and pulled down by weight of the blood, gravity is used to assist in maintaining the venous reservoir in a vertical position. Second, cover 1389 responds to pressure differences across its wall in a useful manner. Thus, when suction is applied to chamber 1309 , cover 1389 pulls tighter against seal 1382 ; the additional sealing force approximating the product of the area of 1389 exposed to the vacuum applied and the level of vacuum. For example, for a cover 2″ wide and 7.5″ long, when a suction of −50 mmHg (−1 psi) the sealing force would be 15 lbs. Similarly, should the vacuum fail, and cover 1389 was not secured to ridged housing 1388 , a build up of pressure within chamber 1309 would provide a force to open cover 1389 to relief pressure should it rise above atmospheric. Accidental pressure build up due to failed vacuum supply can also be achieved by introducing a small “leak” that prevents total sealing yet is small enough to allow suction in the operating room to overcome that leak and provide the desired regulated vacuum. Such a leak could for example be between 100 and 500 cc/min.
[0145] It is obvious that the safety features described with respect to FIG. 8 b apply to bag 1366 and housing 1388 shown FIG. 13 a . For example, housing 1388 is sized to assure that venous reservoir 1366 cannot over-expand beyond defined limits, said limits defined as a volume in blood chamber 138 that would result in a pressure measured at the top of blood chamber 138 of +10 mmHg. Should blood chamber 138 of venous reservoir 1366 expand, walls 1318 and 1319 would move outward until they make contact with the vertical walls of housing 1388 , as shown for walls 18 a and 19 a in FIG. 8 b . Once contact is made, further expansion of walls 1318 and 1319 is limited by the vertical walls of rigid housing 1388 .
[0146] For non-VAVD applications container 1388 need not be sealed. For example, front wall 1388 e of housing 1388 shown in FIG. 13 b , can be minimized or eliminated to allow the user to reach bag 1366 without removing the bag from the holder. This still provides a venous reservoir featuring easy top loading and connections of the inlet tube, outlet tube, and purge port to the extracorporeal circuit made by an end user from the top of the venous reservoir. Top connections are easier to make in the operating room than the side or bottom connections required with prior art soft shell venous reservoirs. It should also be obvious that bag 1366 can incorporate additional tubing (e.g. for cardiotomy return) in a manner similar to that shown for inlet tube 1301 and/or outlet tube 1305 . The advantage of top loading being maintained as long as said additions allow top cover 1389 to be used as shown. To simplify changing from a closed housing and open front wall housing, front wall 1388 e of housing 1388 , can be designed as a removable wall as described in detail in reference to door 1288 of housing 88 in FIGS. 12 a and 12 b.
[0147] The aforementioned design of SSR incorporating a disposable supporting plate adds little cost compared to the added convenience and shorter set up time making it economical to use the bag for standard or VAVD procedures. This reduces cost of inventory and simplifies the user's set up and learning curve.
[0148] It should be emphasized that all the designs for sealing a venous reservoir having at least one flexible wall within a rigid housing for example, as described in reference to FIGS. 8 b , 9 b , 10 b , 12 b , or 13 b , allow the introduction of a venous reservoir into a rigid container without compromising the sterility of the blood contacting surfaces of the venous reservoir. As well known in the art, the blood contacting surfaces of a venous reservoir consist of at least the inside walls of the blood chamber as well as that of the inlet, the outlet, and the air removal tubes. Thus, the present invention overcomes one of the major obstacles, though not mentioned as such in the description of the prior art, inherent in prior art SSR intended to be sealed within a housing, see aforementioned U.S. Pat. No. '045 and PCT '08734.
[0149] Cover 1389 may also incorporate tubing connectors 1389 aa , 1389 bb , 1389 cc, and 1389 dd, shown in FIG. 13 f , that facilitate assembly of bag tubing and eliminate the need for separate tubing connectors. Thus, inlet tube 1301 is sealed (e.g. solvent bonded) to the bottom of inlet connector 1389 aa , said inlet connector providing fluid communication between itself and said inlet tubing. Similarly, outlet tube 1305 is sealed to the bottom of outlet connector 1389 bb , said outlet connector forming fluid communication between itself and said outlet tubing. To further enhance the functionality of outlet connector 1389 bb , unidirectional valve 1305 c may be placed within outlet connector 1389 bb . One-way valve 1305 is a safety feature that prevents back flow from the arterial line, 157 shown in FIG. 1, should arterial pump 1104 stop. Air removal tube 1304 is sealed to the bottom of air removal connector 1389 cc , said connector forming fluid communication between itself and said air removal tubing. Like connector 1389 bb , air removal connector 1389 cc may incorporate unidirectional valve 1304 c . This valve assures that air cannot enter the bag via connector 1389 cc . Lastly, infusion tube 1306 is sealed (e.g. solvent bonded) to the bottom of infusion connector 1389 dd , said infusion connector forming fluid communication between itself and said infusion tubing. An additional advantage of incorporating rigid connectors into cover 1389 : they provide physical strength to the cover further preventing buckling under high vacuum.
[0150] [0150]FIG. 13 f also illustrates means that assure the pressure on the gas side 1105 c of microporous oxygenator 1105 , not fall below that of chamber 1309 . This is achieved by applying the same suction to the outlet of gas port of oxygenator 1105 as is applied to chamber 1309 of FIG. 13 a . Thus, vacuum is provided by vacuum regulator 813 via tube 818 to three-way valve 1391 . Three-way valve 1391 channels the regulated vacuum to tube 1390 a , said tube in fluid communication with chamber 1309 , seen in FIG. 13 a and 13 b , via connector 1308 placed in housing wall 1388 , see FIG. 13 f . Valve 1391 also channels the regulated vacuum to tube 1390 b , said tube in fluid communication with gas side chamber 1105 b of oxygenator 1105 . Tube 1390 b is also in fluid communication with one-way valve 1392 , caged in structure 1393 a having opening 1393 b to atmosphere, said one-way valve opening when pressure in tube 1390 b exceeds atmospheric pressure. A similar one-way valve 1394 , is in fluid communication with tube 1390 a connecting suction port 1308 of housing 1388 to said three-way valve 1391 . Valve 1394 opens when the pressure in tube 1390 a exceeds atmospheric pressure. Both valves 1392 and 1394 provide safety and assure that in the event vacuum, applied to either tube 1390 a or 1390 b , fail, the pressure in said tubes not be built but rather exhaust to atmosphere. It is important the valves 1392 and 1394 have very low cracking pressure, preferably below 10 mmHg. It is also important that these valves present a low resistance to gas flow, preferably requiring no more than 10 mmHg pressure drop at an air flow of 10 L/min. Similarly, vacuum regulator 813 , when used to apply suction to oxygenator 1105 , should accommodate gas flows exceeding that expected for oxygenator 1105 , or 12 L/min for adults. Three-way valve 1391 preferably allows the user to apply suction to chamber 1309 via tube 1309 a but not to oxygenator 1105 , apply suction to both chamber 1309 and oxygenator 1105 , or not to apply suction to either chamber 1309 or oxygenator 1105 .
[0151] Applying suction to the gas side of the oxygenator can reduce O 2 transfer rate because the partial pressure of O 2 , pO 2 , on the gas side is lowered by the percentage decrease in total pressure on the gas side. Thus, when suction of −50 mmHg is applied to the gas side, the total pressure is lowered by 50/760 or 7% thereby nominally reducing the O 2 exchange by 7%. Considering that the percent O 2 used in the sweep gas is less than 100%, it is possible to compensate for decreased total pressure by increasing the % of O 2 in the sweep gas. To avoid reduction in O 2 exchange, it is desirable to apply suction to the gas side only when there is none or very low blood flow. Low blood flow can be indicated by low pressure on the blood side. To achieve this desirable result, suction applied to the gas side of the oxygenator is throttled with valve 1391 , said valve responding to pressure readings taken of arterial line 157 shown in FIG. 1. For example, when the pressure in line 157 falls below 100 mmHg (a pressure indicating low blood flow), a signal is sent to direct valve 1391 to apply suction to gas exhaust line 1390 b of oxygenator 1105 shown in FIG. 13 f . It should be pointed out that the decrease in O 2 exchange due to suction application on the gas side (i.e. reduction in pO 2 ) is compensated by longer residence time of the blood (lower blood flow). Applying vacuum to the gas side has no adverse affect on CO 2 exchange.
[0152] The scope of the invention should not be limited to the aforementioned embodiments. The invention can be extended to other embodiments as illustrated with the venous reservoir having a single flexible wall assigned to Cordis Dow Corp and made by C. R. Bard (U.S. Pat. No. 4,424,190). Currently, there are no means to apply suction to the venous blood utilizing this Bard venous reservoir. With the present invention, applying suction to this design of a venous reservoir is simple. FIGS. 10 a , a three dimensional view, 10 b , a cross sectional view of 103 , and 10 c , a cross sectional view along lines 10 c and 10 c ′ shown in FIG. 10 b , all illustrate a modification of the venous reservoir component shown in FIG. 1 of Pat. No. '190. Blood enters venous reservoir 103 at inlet 101 into chamber 102 , said chamber formed by rigid wall 1019 and flexible wall 1018 , shown in a semi-full position. Wall 1018 is also shown in an almost empty position as indicated by dashed line 1018 ′. Flexible wall is sealed to rigid wall 1019 along periphery 1019 a , said seal made by solvent bonding, RF welding, ultrasonic welding or other appropriate method. Air entering expandable blood chamber 102 is extracted via gas exhaust port 104 . Gas exhaust port 104 may incorporate an automated gas removal means, as shown for example, utilizing a hydrophobic membrane as described in reference to FIG. 5 a . Blood exits via outlet tube 105 . For augmented venous return, the present invention adds face plate 108 that seals the external surface of flexible wall 1018 along periphery 108 a of face plate 108 , forming sealed pressure chamber 107 . The seal 108 a and seal 1019 a therefore can sandwich the free ends of flexible wall 1018 and can be made simultaneously. Gas port 108 b is in fluid communication with sealed pressure chamber 107 , and is preferably connected to vacuum regulator 813 shown and previously described in reference to FIGS. 8 a and 12 a . Faceplate 108 , is preferably clear and rigid such as clear PVC, polycarbonate, polyethylene terephtalate (PET), polyethylene terephtalate glycol (PETG), polyester, or alike. Faceplate 108 does not have to be biocompatible because it does not contact blood. It should be clear that by incorporating sealing means between faceplate 108 and flexible wall 1018 , similar to those described in reference to FIG. 8 a , faceplate 108 could be made nondisposable. Whether disposable or not, faceplate 108 forming pressure chamber 107 allows the user to apply suction to chamber 107 via port 108 b , said suction transmitted to the blood via flexible wall 1018 thereby providing augmented venous return.
[0153] [0153]FIG. 10 b shows nondisposable cover 108 rests within lip 1019 aa of disposable rigid structure 1019 where it is held lightly. When vacuum is applied to suction port 108 b of nondisposable cover 108 , the user would hold cover 108 against periphery 1019 a of structure 1019 . Seal material 1082 a , located along the periphery of cover 108 , is then compressed therebetween forming sealed chamber 107 . The suction within chamber 107 would pull disposable structure 1019 and nondisposable cover 108 together. Thus, the pressure difference across faceplate 108 is used for forming a tighter seal and holding cover 108 . As described in reference to cover 1389 shown in FIG. 13 a , should vacuum fail, any pressure buildup in chamber 107 would push faceplate 108 open to relieve said pressure.
[0154] It should be understood that a comprehensive description of each of the applications of the invention is beyond the scope of a patent application and therefore the aforementioned descriptions are given as illustrations and should not be used to limit the intent, spirit, or scope of the invention. With that in mind, | 4y
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This is a continuation of application Ser. No. 07/770,508, filed Oct. 3, 1991, and now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in general to a method for enhancing recovery of data from a database, and in particular to accelerating generation of search arguments leading to recovery of specific data from the database. Still more particularly, the invention relates to methods generating a dynamic dialog between a data processing machine used to access the database and a user by providing the user access to results of a search as those results are obtained by the data processing machine and accepting refinement of search arguments conceived by the operator during the course of the search.
2. Description of the Prior Art
The prior art teaches the programming of data processing systems for searching through information to retrieve particular pieces of data. An example of such a system is the LEXIS™ legal research system of Mead Data Central, Dayton, Ohio. Such prior art systems access information which has been organized into a database. A database consists of objects, i.e., discrete packets of related information, such as the text of an article. The data processing system recovers the object if the object meets certain criteria. In the example of an article, the criteria could be the presence of a certain series of words in the text. The object is identified to the user and the contents of the object are made available for the user's perusal.
Database searching allows a user to quickly recover collections of objects meeting virtually any criteria a user can compose. A problem with prior art systems has been that they return recovered objects only upon completion of a search. In other words, all objects in a database must be evaluated for conformance to the search criteria before the searcher can review the results. This can be time consuming. It can also present the user with a mass of material effectively as overwhelming as the original database. The user may discover upon completion of a search that the original search criteria were not effective in returning the desired data. This can occur because the operator is unsure of terminology, or because the user defined the criteria too narrowly, or because the user lacked clear understanding of just what was desired, or for a host of other reasons. Obtaining the desired data is hindered by the necessity of waiting for each level or iteration of a search to be completed before the search parameters can be modified, altered or replaced by reference to the search results for the prior parameters.
A conventional approach to searching information is a "search dialog" wherein a command is invoked from a graphical menu system, parameters are filled in a "pop-up window" and results are delivered to a window upon completion of the search. This approach does not fully exploit the capabilities of most data processing systems. Typically, many iterations of the search parameters are required to refine the criteria to solve the user's problem.
SUMMARY OF THE INVENTION
It is therefore one object of the present invention to provide a method of enhancing recovery of desired data from a database.
It is another object of the present invention to provide a method of accelerating the user's generation of search arguments leading to recovery of the desired data from the database.
It is still another object of the present invention to provide a method for generating a dynamic dialog between a data processing machine used to access a database and the user, where the user can access results of a search as obtained by the machine and can repeatedly refine the search arguments during the course of the search with reference to results as obtained.
The foregoing objects are achieved as is now described. A data processing system has access to a memory storing a data or other information base. The data processing system evaluates objects from the data base against search criteria generated from parameters entered into the data processing system by a user. As objects are located by execution of a search program meeting the search criteria, those objects are identified to the user while the search continues. The user can access the qualified objects for conformance to the desired target data. The user may enter modified parameters based upon his evaluation of such results as obtained. The data processing system then continues the search over such part of the database as the user designates.
The above as well as additional objects, features, and advantages of the invention will become apparent in the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
The novel features believed characteristic of the invention are set forth in the appended claims. The invention itself however, as well as a preferred mode of use, further objects and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:
FIG. 1 is pictorial representation of a computer incorporating the present invention;
FIG. 2 is pictorial representation of a plurality of windows imaged on a computer display screen;
FIG. 3 is a pictorial representation of a plurality of windows imaged on a computer display screen after a search has been initiated using and initial search criteria set;
FIG. 4 is a pictorial representation of the plurality of windows imaged on a computer display screen utilizing a set of search criteria subsequent to the first;
FIG. 5 is a logic flow diagram illustrating a portion of the method of the present invention.
FIG. 6 is a logic flow diagram illustrating a portion of the method of the present invention.
FIG. 7 is a logic flow diagram illustrating a portion of the method of the present invention.
FIG. 8 is a logic flow diagram illustrating a portion of the method of the present invention.
FIG. 9 is a logic flow diagram illustrating a portion of the method of the present invention.
FIG. 10 is a logic flow diagram illustrating a portion of the method of the present invention.
FIG. 11 is a logic flow diagram illustrating a portion of the method of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
With reference now to the figures and in particular with reference to FIG. 1, there is depicted a pictorial representation of a personal computer system 10 which may be utilized in accordance with the method of the present invention. Personal computer system 10 includes a computer 12, preferably provided by utilizing an IBM Personal System/2 or similar system. Personal computer system 10 generally includes a keyboard 14, a video display device 16 and may include a mouse 18. Keyboard 14, video display device 16 and mouse 18 are utilized to allow user input to computer 12 and to provide user discernable messages.
FIG. 2 illustrates a pictorial representation of a computer display screen 20 on which are imaged a mouse pointer 22 and windows 24 and 26. Windows 24 and 26 are generated by a computer application program, in this case a database management program. Windows 24 and 26 include window title bars 25 and 27, respectively.
Window 24 is the search criteria frame. Through interaction with window 24 the user may select search criteria which can include values 28 such as strings of text, entered through a value entry field 30. The text string appears in entry field 30, indicating the location where text search parameter may be entered by a user. A database includes a plurality of files or objects, which are the subject of the search. Objects may include data, such as strings of text, authorship, and categorical classification. The user selects object attributes 32 in selection field 33. Attributes 32 relate back to an entry field 30 for a value. Entry field 33 for attributes 32 may be scrolled to bring different attributes into the field of view. Particular attributes may be highlighted by moving mouse pointer 22 to a particular attribute and selecting that attribute. Object attributes selected are highlighted after selection. A field of logical operators 34 includes an equality operator, a not equal operator, a greater than operator, a greater than and equal to operator, a less than operator, a less than and equal to operator, a logical "AND" operator, a plus operator, and a logical OR operator. Ellipses at the end of field 34 indicate additional operators which may be accessed. A selected operator, here the equality symbol, is highlighted by a box 36 surrounding the operator. Operators may be selected by moving mouse pointer 22 to a box and pressing a select button on mouse 18.
A user controls operation of the search through four selection buttons appearing near the bottom of window 24. Initiation of evaluation of the database in terms of values freshly entered through search criteria box window 24 is done by selecting "search" button 38. A "Stop" button 40, upon selection, interrupts a search. A "Resume" button 42, upon selection, causes resumption of an interrupted search over a selected portion of the database. A "Restart" button 44, upon selection, initiates a modified search over the entire database. A search may also be cancelled by exiting window 24.
Database window 26 allows direct access to a database as well as displaying captions for files in a particular database. Database window 26 includes menu bar 46 for accessing the contents of a database for viewing, and editing. A help routine is accessed through menu bar 46.
FIG. 3 illustrates in pictorial representation a computer display screen 20 after definition of a search and commencement of that search. Window 24 exhibits a text value 31 in field 30. An attribute 53 has been selected in attribute entry field 33. Mouse pointer 22 has been moved to the "Search" button 38 and selected, indicating a search has been selected. A search results window 48 has been generated and displayed. Search results window 48 resembles database window 26 and includes menu bar 50 and a results display field 52. An "In Process" message 54 appears in window 48 indicating a search is in process. Results 55 thus far obtained are displayed in results display field 52. Results 55 may be opened for viewing as the search proceeds.
FIG. 4 illustrates a pictorial representation of computer display screen 20 after modification of a search as provided by the present invention. Searches may be interrupted by user selection with the "Stop" button 40. This action reopens window 24 for the selection of new or modified search criteria. As illustrated, a new search has been entered through search criteria window 24 and includes a new value 37 in value entry field 30 and a new logical operator selected from operator button 34. Mouse pointer 22 has been moved to the "Resume" button 42 indicating resumption of the search with the new search criteria.
Search results window 48 reflects the selection of new search criteria. Results field 52 is divided by a hatched line 63 into two subsidiary fields 62 and 64, respectively. Subsidiary field 62 displays qualifying files found with the original search criteria. Search results subsidiary field 62 also illustrates the original search arguments as a search development aid to the user. Search results subsidiary field 64, in which in process bar 54 appears, displays files so far located using the new search criteria. "In Process" message 54 indicates that the database has not yet been exhausted and that additional files may be displayed as located.
With reference to FIGS. 5-11, there are depicted logic flow charts illustrating the search routines of the present invention.
FIG. 5 illustrates operation of the process of the invention on a typical personal computer, which begins with the loading of an operating system from peripheral memory. This occurs at block 70 labeled "Start" indicating power up and system tests and block 72 labeled "Initialize System, Memory and Display" indicating loading of an operating system. The present invention operates in a "windows" environment, which is preferably provided by the OS/2® operating system and an associated graphic user interface such as the "Presentation Manager"® available from the International Business Machines Corporation. The Presentation Manager graphic user interface is a layer of software which resides on the operating system. The presentation manager fetches windows, pointers and objects for display screen 20 as illustrated by box 74.
Next, block 76 illustrates a wait period by the computer until a user initiates some action. Block 76 is also a reentry point indicated by the letter A, circle 78, from various other points in the process. At block 76 computer waits on user selection of a menu item from a window displayed on visual display device 16.
Next, blocks 80, 84, 88, 92, 96, and 100 illustrate possible responses by computer 12 after selection of an operation by a user. A number of responses are possible. Only those responses relating to database inquiry as modified by the present invention are illustrated in detail. Decision block 80 illustrates determination of whether the user has requested viewing current search criteria. If so, the process is diverted to a criteria routine by way of block 82. Otherwise, at decision block 84, it is determined whether the user has initiated a search using current criteria. If yes, program execution is diverted to a search subroutine via block 86. Otherwise, at decision block 88 it is determined if a current search has been resumed after an interruption. If the user has requested a resumption of a search, program execution is diverted to a resume routine indicated by block 90. Otherwise, program execution continues to block 92 where it is determined if a user has cancelled a search. If the user has selected cancellation of a search routine, execution is sent to a cancel routine via block 94. Otherwise, program execution continues to block 96 where it is determined if a search has been restarted. A restart routine is entered through block 98 from the yes branch from block 96. Otherwise, program execution moves to block 100 indicating some other user action has been selected not related to the search functions of the present invention. These other actions, such as word processing, do not directly relate to the present invention and are not discussed further here. From block 100, processing returns to block 76 via path 78 to monitor for another user input.
FIG. 6 illustrates the criteria selection routine. The routine is entered through block 82. Next, block 102 is utilized to fetch window frame 24 for display to a user. Next, any prior search criteria are fetched and formatted for display utilizing block 104. Next, blocks 106 and 108 illustrate transfer of the window and search criteria to the display screen for user viewing. Next, block 110 illustrates the computer waiting for the user to change or to input new search criteria values. Next block 112 illustrates receipt of such user selected values whereupon they are formatted and displayed to the user for confirmation. Next block 114 illustrates the changes being saved as current search criteria and program execution being returned via block 78 to the monitor block 76 of FIG. 5.
FIG. 7 illustrates a search subroutine entered through block 86. From block 86, block 116 is utilized for fetching current search criteria in preparation for display of the criteria to a user and for evaluation of database objects in processing a search. Next, block 118 illustrates retrieval of a pointer to the database to be searched. The pointer indicates the specific object in the database to be searched and indirectly establishes the quanta of the database to be searched. Next, block 120 illustrates retrieval of the data supporting generation of a search results window frame, which is used to display results as obtained. Next, block 122 illustrates generation of an "In Process" message for inclusion in the results window frame question block 120. Next, block 124 illustrates writing the information to be generated on the display to a display buffer and the updating of the display with the search results window frame and in process data.
Next, at block 126, the search routine enters an evaluation process relating to database searching is executed in a conventional manner. Block 126 illustrates calling the next object in a database in comparison of the contents and attributes of the object with the search criteria. Next, decision block 128 illustrates comparison of the contents of the object with the search criteria. Where the object meets the search criteria the results are presented to a user as provided by block 130 along the yes branch from decision block 128. Block 130 is utilized to format and identify objects in the results window.
Next block 132 determines if the most recently searched object is the last object in a database, in which case the search has been completed. Decision block 132 follows both block 130 and the no branch from decision block 128. If an object is the last process execution is returned to block 76 via "A".
Search check block 134 follows the negative decision branch from block 132. The search check routine, which is described below, may result in the search being aborted under some conditions, and under other conditions reentering the search routine through entry point B at 138. Hatched line from search check 134 to block 136 indicates the usual result from operation of the search check routine and will be understood not to be the direct route stemming from execution of the routine. Next, block 136 illustrates updating the data and display pointers from which execution of the routine advances back to block 126. The process repeats until all objects of a database have been searched.
The search check subroutine illustrated beginning at block 134 in FIG. 8 reflects monitoring for user involvement in the search. Next, decision block 140 is utilized to determine if a user has stopped the search. Stopping a search is to be distinguished from cancelling a search. The affirmative decision branch from decision block 140 returns execution of the process to block 76 in FIG. 5. The negative decision branch from block 140 results in the process advancing to decision block 142 where it is determined whether a user has instructed the computer to resume a search. The affirmative decision branch from block 142 returns the process to the search routine of FIG. 7 at letter "B" via block 138. The negative decision branch advances the process to the decision block 144 where it is determined if a user has instructed a restart of search. The affirmative branch where it takes the process through block 98 to a restart routine. The negative branch advances search execution decision block 146 where it is determine if the user has cancelled the search, i.e., instructed the computer to exit from the database search routine altogether. The affirmative branch takes execution of the process through block 94 to a cancel routine. A negative decision returns execution of the process through block 138 to the search routine as described above.
FIG. 9 illustrates a cancel routine entered through block 94. The cancel routine releases computer memory for other programs. Block 148 illustrates, upon entry into the cancel routine, erasure of the results window from user view. Next, block 150 illustrates changing the display buffer and resulting display as a result of cancellation of the search routine. Next, block 152 illustrates the release of memory, here the main computer memory, from the program and information data required for execution of the search. Process execution is returned to user monitor status at block 76 at A via block 78.
FIG. 10 illustrates the restart routine entered via block 98. The restart routine is essentially initiation of a new search over an entire database. In order to display to a user information reflecting such a restart, and to execute the search over an entire database, certain changes in memory and repositioning of search pointers is required. Block 154, following entry into the restart routine, illustrates erasure of current search results. Next, block 156 illustrates the fetching of the current search criteria and data entered by the user. Next, block 158 illustrates updating data and display pointers for resuming the search and for indicating to the user the status of the search. Next block 160 illustrates updating of the display buffer and display in concordance with the updated data and display pointers. Next, block 86 illustrates return of the program to the search subroutine illustrated in FIG. 7.
FIG. 11 illustrates the "resume" routine utilized where a user determines that new search criteria are required, but that the entire database need not be searched. Resume can also be entered without modification of a search. Decision block 162 illustrates consideration of both possibilities. When new search criteria have been entered, process execution follows the affirmative decision path. Where no new search criteria have been entered, the decision program follows the negative decision path to decision block 163 where it is determined if the scope of the search has been changed. If the scope of the search is unchanged execution proceeds via block 138 back into the search routine of FIG. 7. Alternatively, process execution can be delivered to block 168 to permit repositioning of a search point. Block 164 follows the affirmative decision path from block 12 and illustrates fetching the new search criteria entered by the user. Next, block 161 illustrates writing the prior criteria and the separator after those results obtained using the prior criteria. Next block 168 allows for display and data pointers to be reset to define the ambit of the new search with respect to objects in the database. Next, block 170 illustrates update of the display buffer and display with the new information and return of the program to searching via block 138 at letter B.
A user gains from employing the present invention with an otherwise conventional database search scheme by gaining the ability to dynamically revise search parameters during the course of a search. This feature saves the user considerable time and frustration in the employment of database searching.
While the invention has been particularly shown and described with reference to a preferred embodiment it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention.
Although the invention has been described with reference to a specific embodiment, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiment as well as alternative embodiments of the invention will become apparent to persons skilled in the art upon reference to the description of the invention. It is therefore contemplated that the appended claims will cover any such modifications or embodiments that fall within the true scope of the invention. | 4y
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a method for producing a pressure vessel, in particular a pressure vessel for a vehicle. Further, the invention relates to a pressure vessel, in particular a pressure vessel for a vehicle.
[0002] More specifically, the invention relates to a pressure vessel for receiving and storing a medium under overpressure and a method for producing same.
[0003] A pressure vessel, in particular for a vehicle, is known from document DE 299 09 827 U1. This document discloses a pressure vessel for receiving and storing a medium under overpressure, comprising a vessel main part which is closed in a pressure-tight manner by an arched cover and an arched base. For this purpose, the cover at the cover end of the vessel main part and the base at the base end of the vessel main part are welded to the vessel main part. The vessel main part has a plurality of cross-webs which connect opposite wall segments of the wall of the vessel main part to one another in order to give the vessel main part the required pressure resistance.
[0004] In the case of the known pressure vessel, the vessel main part is finish-machined before mounting the cover and the base on the vessel main part. On the one hand, this process involves introducing grooves into the cross-webs in the respective transition regions thereof into the wall of the vessel main part. The grooves serve for the centred reception of the cover and of the base at the first and second openings of the vessel main part. Moreover, the vessel main part is adapted to the outer circumference of the cover attachment rim and of the base attachment rim in the region of the first opening and of the second opening in order to compensate for tolerances between the vessel main part and the cover and base.
[0005] The finish-machining processes on the vessel main part which have been described above are each accomplished by cutting, i.e. by the removal of material.
[0006] However, a finish-machining process on the vessel main part involving cutting is expensive and time-consuming, and this has a disadvantageous effect on the production process.
[0007] Moreover, a finish-machining process on the vessel main part involving the removal of material in order to introduce the grooves and for the above-described tolerance compensation to allow accurately fitting reception of the cover and base elements is associated with a reduction in the wall thickness of the vessel main part. This reduction in wall thickness leads to weakening of the wall of the vessel main part, especially in the cover and base attachment regions of the vessel main part, and this can result in a preferential breaking point or a possible lack of leaktightness in the vessel main part.
[0008] The above-described weakening of the wall of the vessel main part due to the finish-machining involving cutting must therefore be compensated by deliberate reinforcement of the wall, at least in the cover and base attachment regions. Here, the reinforcement of the wall should be provided either during the production of the vessel main part, by producing the vessel main part overall with a greater wall thickness, or introduced subsequently into the vessel main part, e.g. by deposition welding. Producing the vessel main part with a greater wall thickness disadvantageously leads to a higher weight of the pressure vessel and to higher costs for materials in the production of the pressure vessel. Subsequent reinforcement of the wall of the vessel main part is a time-consuming and expensive measure.
[0009] DE 102 12 801 C1 discloses a cooler for liquid media which is constructed from a main profile and a plurality of webs arranged therein. In order to ensure a meandering flow of the liquid medium, the ends of the webs, which project beyond the longitudinal ends of the main profile, are pressed into the interior of the profile. The open ends of the main profile are then soldered to end plates and thus closed.
SUMMARY OF THE INVENTION
[0010] It is an object of the invention to provide a method for producing a pressure vessel, in particular for a vehicle, which can be carried out with high production accuracy and with a lower outlay in terms of materials, time and cost.
[0011] It is another object of the invention to provide a pressure vessel of the type stated at the outset which can be produced with high production accuracy and with a lower outlay in terms of materials, time and cost.
[0012] According to the invention, a method for producing a pressure vessel is provided, comprising the steps:
[0013] a) providing a vessel main part, which has a wall, a first opening at a first end, a second opening at a second end and at least one cross-web, which connects opposite wall segments of the wall of the vessel main part to one another,
[0014] b) providing an arched cover and an arched base, wherein the arched cover has a cover attachment rim and the arched base has a base attachment rim,
[0015] c) embossing, without cutting, a first and a second groove into the at least one cross-web at the first opening and introducing a third and fourth groove into the at least one cross-web at the second opening, wherein the grooves are embossed in respective regions of connection of the at least one cross-web to the opposite wall segments of the vessel main part,
[0016] d) inserting the cover attachment rim into the grooves at the first opening and inserting the base attachment rim into the grooves at the second opening,
[0017] e) securing the cover and the base on the vessel main part in the region of the first and second ends in order to close the vessel main part in a pressure-tight manner.
[0018] Further according to the invention, a pressure vessel for receiving and storing a medium under overpressure is provided, comprising a vessel main part having a wall and at least one cross-web connecting opposite wall segments of the wall to one another, and further comprising a first opening and a second opening, an arched cover closing the vessel main part at the first opening and having a cover attachment rim, an arched base closing the vessel main part at the second opening and having a base attachment rim, a first and a second groove in the at least one cross-web at the first opening in the vessel main part, the cover attachment rim being received in the first and second grooves, a third and a fourth groove in the at least one cross-web at the second opening in the vessel main part, the base attachment rim being received in the third and fourth grooves, the grooves being embossed, without cutting, in respective regions of connection of the at least one cross-web to the opposite wall segments.
[0019] In the case of the method according to the invention and of the pressure vessel according to the invention, the grooves for the centred reception of the cover and of the base are introduced into the at least one cross-web without cutting, more specifically by embossing. Embossing the grooves has the advantage that no material is removed during embossing, and therefore weakening of the material of the vessel main part is avoided.
[0020] In the context of the present invention, the term “groove” should be taken to mean a recess, the length of which can also be shorter than the width thereof.
[0021] As a result, it is possible to dispense with the additional use of reinforcing regions, at least in the region of the region of connection of the at least one cross-web to the opposite wall segments of the vessel main part, which is preferably produced as an extruded aluminium profile, thereby enabling the pressure vessel to be produced with a lower weight, at lower cost and with a reduced outlay on processing.
[0022] The grooves are preferably embossed into the at least one cross-web in such a way that centred reception of the cover attachment rim on the vessel main part at the first opening and of the base attachment rim on the vessel main part at the second opening is ensured.
[0023] This facilitates correctly positioned placement of the cover and of the base on the vessel main part.
[0024] In a preferred embodiment of the method according to the invention and of the pressure vessel according to the invention, the wall of the vessel main part is finish-sized by forming, without cutting, in the region of the first opening and of the second opening in order to adapt an inside of the wall to an outer circumference of the cover attachment rim and of the base attachment rim.
[0025] By means of this measure, any manufacturing tolerances of the vessel main part, of the cover and of the base are advantageously compensated, likewise without cutting, i.e. without removing material. Finish-sizing the vessel main part by forming without cutting has the advantage that weakening of the material of the wall of the vessel main part is avoided, thus eliminating the need for the vessel main part either to be produced with a greater wall thickness from the outset or for the wall thickness to be increased afterwards by the application of material. In combination with the embossed grooves, the pressure vessel according to the invention in this embodiment is particularly sparing of materials and can be produced at reasonable cost and with less expenditure of time.
[0026] Finish-sizing of the vessel main part by forming without cutting is preferably carried out by pressing the wall of the vessel main part, e.g. by pressing it from the outside in order to displace a wall segment inwards, and/or by pressing it from the inside in order to displace a wall segment outwards.
[0027] Finish-sizing ensures that the cover attachment rim and the base attachment rim can be received with an accurate fit into the attachment regions of the vessel main part which are predefined by the introduced grooves, on the one hand, and the inside of the wall, on the other hand, and this has an advantageous effect on the quality of attachment of the cover and of the base to the vessel main part.
[0028] In another preferred embodiment of the method and of the pressure vessel, the wall of the vessel main part is configured with a uniform wall thickness all the way round the circumference.
[0029] It is advantageous here that the vessel main part can be produced at particularly low cost, in particular as an extruded aluminium profile. Moreover, it is ensured that the stresses acting on the wall of the vessel main part are distributed uniformly.
[0030] In another preferred embodiment of the method and of the pressure vessel, the cover and the base are joined to the vessel main part by a material joint, in particular a welded joint or an adhesive joint.
[0031] This measure has the advantage that the base and the cover can be joined to the vessel main part at low cost and in a pressure-tight manner by means of a welded or an adhesive joint.
[0032] In another preferred embodiment of the method, the grooves are formed with a bevelled shoulder in the form of a chamfer during embossing.
[0033] In the case of the pressure vessel, the grooves preferably have a bevelled shoulder in the form of a chamfer.
[0034] This measure advantageously facilitates the insertion of the cover attachment rim and the base attachment rim into the respective attachment regions formed by the grooves and the inside of the wall of the vessel main part. The chamfer is produced during the embossing of the grooves, thus advantageously eliminating an additional processing operation.
[0035] By means of the method according to the invention, the pressure vessel according to the invention can be produced at low cost, with a low weight and with a low reject rate in a series production process.
[0036] Further advantages and features will emerge from the following description and the attached drawing.
[0037] It is obvious that the features mentioned above and those which remain to be explained below can be used not only in the respectively indicated combination but also in other combinations or in isolation without exceeding the scope of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] An illustrative embodiment of the invention is shown in the drawing and is described in greater detail with reference to the latter. In the drawing:
[0039] FIG. 1 shows a pressure vessel in an exploded perspective view;
[0040] FIG. 2 shows, in perspective, a vessel main part of the pressure vessel in FIG. 1 in an intermediate stage of the production of the pressure vessel in FIG. 1 ;
[0041] FIG. 3 shows, in perspective, the vessel main part in FIG. 2 in a further intermediate stage of the production of the pressure vessel;
[0042] FIG. 3 a shows a detail A in FIG. 3 on a larger scale than FIG. 3 ;
[0043] FIG. 3 b shows a detail B in FIG. 3 on a larger scale than FIG. 3 ; and
[0044] FIG. 4 shows, in perspective, the pressure vessel in FIG. 1 in partially sectioned view in the finished condition.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0045] A pressure vessel provided with the general reference sign 10 is shown in an exploded view in FIG. 1 . Further details of the pressure vessel 10 and of the production thereof are shown in FIGS. 2 to 4 .
[0046] The pressure vessel 10 is used in a vehicle (not shown). The pressure vessel 10 is used in general to receive and store a medium under overpressure, which can be a gas, a liquid or steam. The pressure vessel 10 can be used as a storage and compensation tank for pneumatic control systems in motor vehicles, for example. One specific application is, for example, the use of the pressure vessel 10 as a compensation and storage tank for compressed air in a pneumatic chassis suspension system of a vehicle.
[0047] The pressure vessel 10 has a vessel main part 12 which, overall, is formed integrally of metal, in particular steel or aluminium sheet. The vessel main part 12 can have been produced, for example, by a cold forming method, in particular by extrusion.
[0048] The pressure vessel 10 furthermore has a cover 14 and a base 16 , wherein both the cover 14 and the base 16 are of arched design. The shaping of the vessel main part 12 , of the cover 14 and of the base 16 can fundamentally be matched in terms of the geometry and configuration thereof to the installation location at which the pressure vessel 10 is to be positioned. The arching of the cover 14 and the arching of the base 16 fundamentally ensure uniform pressure distribution at the surface of the cover and the surface of the base.
[0049] On the side facing the vessel main part 12 , the cover 14 has a cover attachment rim 18 , which extends along the entire circumference of a cover rim 20 . On the side facing the vessel main part 12 , the base 16 has a base attachment rim 22 , which is formed along the entire circumference of a base rim 24 .
[0050] The vessel main part 12 has a substantially box-shaped form, wherein the vessel main part 12 furthermore has arched ends 26 , 28 . Fundamentally, however, the vessel main part 12 can be configured in any desired box-shaped form which is matched to an installation location of the pressure vessel 10 .
[0051] The vessel main part 12 has opposite lateral wall segments 30 , 32 , which are connected to one another by cross-webs 34 . There are four cross-webs 34 in the embodiment shown. The vessel main part 12 thus has a wall 36 all around the circumference, being formed by the opposite wall segments 30 , 32 and the wall segments of the arched ends 26 , 28 . It is self-evident that the number of cross-webs 34 can be less than four or indeed greater than four, depending on the size of the pressure vessel 10 .
[0052] The cross-webs 34 which connect the opposite wall segments 30 , 32 to one another extend in the vessel main part 12 from a cover-side first opening 38 at a first end 39 of the vessel main part 12 , to a base-side second opening 40 at a second end 41 of the vessel main part 12 .
[0053] In the embodiment shown, the individual cross-webs 34 are aligned so as to be straight and flat and parallel to one another. However, it is self-evident that the cross-webs 34 can also be arranged so as not to be parallel to one another.
[0054] Wall segments 30 , 32 are formed integrally with the wall segments of the arched ends 26 , 28 and the cross-webs 34 . This can be achieved by producing the vessel main part 12 as an extruded profile made of metal, e.g. aluminium. The direction of extrusion is in the direction of the longitudinal extent of the cross-webs 34 , i.e. in the direction of the connection between the cover-side first opening 38 and the base-side second opening 40 . In this case, the vessel main part 12 can be produced as a metre-length extruded profile and then cut to length as required from this metre-length material.
[0055] At wall segments 30 , 32 , the cross-webs 34 each have regions 42 of connection to the wall 36 , said regions widening towards the walls 36 in a section plane orthogonal to the surface of the cross-webs 34 (cf. also FIG. 3 a , FIG. 3 b ).
[0056] At the first opening 38 , the cross-webs 34 each have a first groove 44 a and a second groove 44 b, which are introduced without cutting, by embossing (stamping), into the cross-webs 34 in the region of the respective regions 42 of connection of the cross-webs 34 to wall segments 30 , 32 . Moreover, the cross-webs 34 each have, at the second opening 40 , further, third and fourth grooves 45 a, 45 b (see FIG. 4 ), which are introduced without cutting, by embossing, into the cross-webs 34 in the region of the regions 42 of connection of the cross-webs 34 to wall segments 30 , 32 . In this case, grooves 44 a and 45 a are situated opposite one another, as are grooves 44 b and 45 b. The embossed grooves 44 a, 44 b, 45 a, 45 b, on the one hand, and an inside 46 of the wall 36 of the vessel main part 12 , on the other hand, result in first and second attachment regions 48 , 50 at the cover-side first opening 38 and at the base-side second opening 40 , said attachment regions receiving the cover attachment rim 18 of the cover 14 and the base attachment rim 22 of the base 16 , respectively.
[0057] In FIG. 2 , the vessel main part 12 of the pressure vessel 10 is shown in an intermediate stage of production. In the intermediate stage show in FIG. 2 , the vessel main part 12 is provided as an extruded profile, wherein the grooves 44 a, 44 b and 45 a , 45 b have not yet been introduced into the cross-webs 34 .
[0058] Starting from the stage in FIG. 2 , the vessel main part 12 is shown in a subsequent stage of production in FIG. 3 . At this stage, as explained above, the grooves 44 a, 44 b, 45 a, 45 b have been introduced into the cross-webs 34 of the extruded blank of the vessel main part 12 in the region of the cover-side first opening 38 and of the base-side second opening 40 . The grooves 44 a, 44 b, 45 a, 45 b are embossed into the cross-webs 34 in respective regions 42 of connection of the cross-webs 34 to wall segments 30 , 32 . The grooves 44 a, 44 b, 45 a, 45 b are designed in such a way that they, on the one hand, and the inside 46 of the wall 36 of the vessel main part 12 , on the other hand, form the first attachment region 48 for the cover attachment rim 18 at the cover-side first opening 38 and the second attachment region 50 for the base attachment rim 22 at the base-side second opening 40 of the vessel main part 12 . In this case, the grooves 44 a , 44 b, 45 a, 45 b are designed in such a way that they can receive the cover attachment rim 18 and the base attachment rim 20 in a centred manner.
[0059] One of the grooves 44 a is shown on an enlarged scale in FIG. 3 a . One of the grooves 44 b is shown on an enlarged scale in FIG. 3 b . Grooves 44 a, 44 b and grooves 45 a, 45 b are introduced by embossing material of the cross-webs 34 . During the embossing of grooves 44 a, 44 b, material of the cross-webs 34 is displaced in a direction from the first opening 38 towards the second opening 40 . The embossing of grooves 45 a, 45 b takes place in the opposite direction, i.e. in a direction from the second opening 40 towards the first opening 38 . As is evident from FIGS. 3 a and 3 b , grooves 44 a, 44 b have a substantially rectangular profile (and the same applies to grooves 45 a, 45 b ). On the side thereof facing away from the wall 36 , the grooves 44 a, 44 b, 45 a, 45 b have a bevelled shoulder 52 in the form of a chamfer, which makes it easier to insert the cover attachment rim 18 and the base attachment rim 22 into the grooves 44 a, 44 b, 45 a, 45 b.
[0060] It is self-evident that the profiles of grooves 44 a, 44 b and 45 a, 45 b can also have profile shapes which deviate from the profile shape shown. Thus, grooves 44 a , 44 b and 45 a, 45 b can also be of round or stepped design.
[0061] Embossing the grooves 44 a, 44 b, 45 a, 45 b ensures that the wall thickness 54 of the wall 36 is not reduced in the attachment regions 48 , 50 .
[0062] In order to adapt the inside 46 of the wall 36 to the outer circumference of the cover attachment rim 18 and to the outer circumference of the base attachment rim 22 , the wall 36 of the vessel main part 12 is finish-sized by forming, without cutting, in the region of the first opening 38 and of the second opening 40 , if such adaptation is required due to manufacturing tolerances during the production of the vessel main part 12 , of the cover 14 and/or of the base 16 .
[0063] Finish-sizing the vessel main part 12 by forming without cutting in the region of the first opening 38 and of the second opening 40 is accomplished by pressing the wall 36 of the vessel main part 12 in sections, namely inwards (e.g. arrows 53 in FIG. 3 ) and/or outwards (e.g. arrows 55 in FIG. 3 ), depending on whether the outer circumference of the vessel main part 12 has to be reduced or increased completely or in sections at the first opening 38 and at the second opening 40 . By virtue of the finish-sizing by forming without cutting, the vessel main part 12 has a uniform wall thickness 54 over the entire circumference (see FIGS. 3 a and 3 b ).
[0064] FIG. 4 shows the pressure vessel 10 in the finished stage. In contrast to FIG. 1 , the pressure vessel 10 in FIG. 4 is shown with a view of the base 16 , whereas FIG. 1 shows the pressure vessel 10 with a view of the cover 14 . Moreover, in FIG. 4 the base 16 is shown cut away.
[0065] During the transition from FIG. 3 to FIG. 4 , the cover 14 has been placed on the first opening 38 of the vessel main part 12 , or, to be more specific, the cover attachment rim 18 has been inserted into grooves 44 a, 44 b of the cross-webs 34 . During this process, grooves 44 a, 44 b bring about centring of the cover 14 on the vessel main part 12 .
[0066] In the same way, the base 16 has been placed on the second opening 40 of the vessel main part 12 , i.e. the base attachment rim 22 is inserted into grooves 45 a , 45 b of the cross-webs 34 . Here too, grooves 45 a, 45 b bring about centring of the base 16 on the vessel main part 12 .
[0067] The cover 14 and the base 16 are then welded to the vessel main part 12 in order to close the pressure vessel 10 in a pressure-tight manner. FIG. 4 shows the welding by means of weld seams 56 , which extend around the entire circumference of the vessel main part 12 .
[0068] It is also possible for the cover 14 and/or the base 16 to be connected to the vessel main part 12 by adhesive bonding instead of by welding. | 4y
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The present invention is related to the field of electrical components, and more particularly is related to the field of shunts for circuit panels.
BACKGROUND OF THE INVENTION
Shunts for circuit panels are known which have a plurality of pairs of contacts for completing circuit paths of a circuit panel, where it is desired to program the circuit panel by bringing at least a selected one of the circuit paths into a closed condition by a corresponding electrically joined pair of contacts. Programming of the shunt to program the circuit panel by opening a selected circuit path is accomplished by physical breaking of the strap electrically connecting the particular pair of contacts in the shunt corresponding to that path, as known from the DIP shunt sold by AMP Incorporated of Harrisburg, Pa. under Part No. 435704-5. Such a shunt cannot be sealed, because the aperture must remain open to receive the strap-breaking tool. Also and more importantly close spacing of the contact pairs is not feasible due to the need for adequate lateral spacing to receive the tool for assured breaking of only the selected strap and not adjoining ones. An improved method of creating a discontinuity between a selected pair of contacts is desired not requiring tool insertion.
SUMMARY OF THE INVENTION
The electrical component of the present invention has pairs of contacts having outer contact sections electrically engageable with contact sections of circuit paths of a circuit panel such as a circuit board or a flexible panel. Inner contact sections are in spaced pairs in respective cavities of the housing and are bridged by a fuse element secured thereto in electrical engagement therewith. The fuse element has a selected in-service current-carrying capability corresponding with that of the circuit path whose circuit it completes upon the components being secured to the circuit panel, and also has characteristics selected to cause opening of the fuse upon application of a designed electrical programming current by melting due to heat buildup from high resistance due to the small diameter.
According to one method of using the electrical component of the invention, the component serves as a programmable shunt for programming the circuit panel. The outer contact sections corresponding to the circuit path desired to be an open path, have applied thereto a designed programming current prior to mounting the component to the circuit panel. Programming current can also be applied after mounting the component to the panel by applying it to the circuit path desired to be opened, which may be done prior to mounting the thus-programmed circuit panel into its ultimate in-service site. Such applied programming current opens the corresponding fuse element and breaks the electrical connection between the inner contact sections.
According to other aspects of the electrical component of the present invention the contacts can be insert molded in the housing, the cavities of the housing containing the fused inner contact sections can be sealed, and the outer contact sections can be disposed in a dual in-line arrangement and can either comprise vertical legs for insertion into panel holes and soldered to conductive pads of the circuit paths or can have horizontal sections for surface mounting to conductive pads of the circuit paths. The fuse element can be welded, bonded or crimped to the inner contact sections and can comprise a length of fine wire such as 0.0015 inch diameter constantan or copper alloy wire, or 0.0007 inch diameter aluminum wire.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the electrical component of the invention exploded from a printed circuit board with a housing end wall portion broken away.
FIG. 2 is a cross-sectional view taken along lines 2--2 of FIG. 1.
FIG. 2A is similar to FIG. 2 representing an alternate embodiment of securing the fuse element, and of the outer contact sections.
FIG. 3 is a perspective view showing a segment of a flexible circuit panel having conductive pads for surface mounting of the embodiment of the electrical component of FIG. 2A.
FIGS. 4A-4D are perspective views illustrating sequentially one method of making the electrical component of FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1 and 2 show the electrical component 10 of the present invention having a housing 12 and a plurality of pairs of contacts 14A,14B spaced therealong preferably in a dual in-line arrangement. Each contact 14A has an innner contact section 16A spaced proximate an inner contact section 16B of its corresponding contact 14B. A fuse element 30 extends between the pair of inner contact sections 16A,16B and is mechanically secured thereto at joints 32 in electrical engagement therewith. Each of the pair of contacts 14A,14B also has an outer contact section 18A,18B respectively for electrical engagement with a corresponding contact means of an elecrical circuit path on a circuit panel. Fused inner contact sections 16A,16B are preferably disposed in respective cavities 20 of housing 12. The electrical component is preferably sealed by securing a sealing member 22 to the top 24 of housing 12 and a sealing member 26 to the bottom 28 of the housing. Outer contact sections 18A,18B are vertical leg sections for insertion into holes 54 which form part of the circuit paths 52 on a rigid circuit panel such as a printed circuit board 50. The fuse element 30 is preferably secured for performance reasons to the top surfaces of inner contact sections 16A,16B and arced upwardly away from the ends of the contact sections.
FIG. 2A illustrates an alternate embodiment where fuse element 30 is secured by joints 32 to bottom surfaces of the inner contact sections 46A,46B of contacts 44A,4B, in housing 42 of component 40. Because the walls of the housing must have a height sufficient to enable handling by automated handling apparatus for positioning on a circuit panel, it is easier during fabrication of the fuse shunt to secure the fuse element 30 to the bottom surfaces of contact sections 46A,46B which are proximate the bottom face of the fuse shunt. Contacts 44A,44B include outer contact sections 48A,48B which comprise a pair of coplanar horizontally extending sections, for surface mounting to conductive pads 64 of the circuit paths 62 on the surface of a circuit panel, such as flexible circuit panel 60 as shown in FIG. 3.
The fuse element is secured to the inner contact sections such as by conventional resistance welding or wire bonding techniques to form joints 32. Another method of joining the fuse element is disclosed in U.S. patent application Ser. No. 857,209 filed Apr. 29,1986. In that method the fuse element is a wire segment first disposed in a groove skived axially along the inner contact sections and then terminated by deforming portions of the inner contact sections forming sidewalls of the groove over the top of the wire at at least one location on each inner connect section by means of a terminating tool. Various methods based on conventional techniques may be used so long as heat is not generated in sufficient amounts to inadvertently open or damage the fuse element which is fragile requiring care in handling and processing.
It is believed preferable to secure the fuse element to the pair of contact sections after securing the contacts in the housing, so that the housing provides mechanical stability and enhances physical protection of the fragile wire fuse element during fabrication as is shown in FIGS. 4 A to 4C. While joined to a carrier strip 70, the contacts 14A,14B are preferably placed in a mold and a dielectric housing 12 molded thereto by conventional insert molding techniques, as shown in FIG. 4B. The fuse elements 30 are then secured to respective contact sections, as in FIG. 4C. Thin, transparent sealing membranes 22,26 are then preferably adhered to the top and bottom surfaces 24,28 respectively of housing 12 completing the manufacture of the electrical component, as in FIG. 4D. The completed components can then be severed from the carrier strip and the outer contact sections 18A,18B formed into the desired configuration. The contacts 14A,14B are preferably stamped from a strip of copper alloy, and outer contact sections 18A,18B may be tin-lead plated for solderability. Housing 12 may be formed of a thermoplastic material such as glass-filled polyester resin. Sealing membranes 22,26 may be MYLAR (trademark of E. I. du Pont de Nemours and Company).
Fuse element 30 is preferably a wire segment of a selected very small diameter creating high resistance, and may be any of several conventional types of conductive metals such as high copper content alloy, aluminum, silver alloy, or constantan. The proper material to be used, and the actual diameter selected depend on the type of current desired to be carried by the fuse during normal in-service use and also the designed programming current for opening the fuse element. For example, a satisfactory fuse element can be a short length of aluminum wire having a diameter of 0.0007 inches if it is desired that the fuse carry an in-service current of 0.100 amperes and open upon receiving a programming current of 1.0 amperes for 100 milliseconds or less. A satisfactory fuse element can be a short length of constantan alloy having a diameter of 0.0015 inches for the same in-service and programming currents.
The fuse element opens by melting upon sufficient heat buildup resulting from the programming current passing through its very small diameter, and limited length for sufficient time. It is possible to estimate an appropriate small diameter for the fuse element when the following items are known: the programming current (l p ) and programming time (t), length of the fuse (L), ambient temperature (T a ), and metal alloy being used for the fuse. Characteristic properties of the metal alloy are ascertained: melting temperature T m , specific heat (Cp), latent heat of fusion (Q f ), resistivity (ρ), and specific gravity (SG).
The heat required to melt the fuse is related to the fuse element dimensions and properties as follows:
HEAT=MASS×[(T.sub.m -T.sub.a)Cp+Q.sub.f ] (1)
where the mass of the fuse element is ##EQU1##
The power generated by the current through the fuse is
POWER=l.sub.p.sup.2 R (3)
where
R=ρ4L/πD.sup.2 (4)
and the power and heat to melt are related to each other as:
HEAT=POWER×t (5)
EXAMPLES
Where two metal alloys are considered, constantan and aluminum, their characteristic values are as follows:
TABLE 1______________________________________ Constantan Aluminum______________________________________SG (specific gravity) 0.323 lb/ft.sup.3 0.0975 lb/ft.sup.3T.sub.m (melting temperature) 2210° F. 660° F.Cp (specific heat) 0.098 Btu/lb/°F. 0.215 Btu/lb/°F.Q.sub.f (latent heat of fusion) 100 Btu/lb 170 Btu/lbρ (resistivity) 374 Ω mil.sup.2 /ft 20.37 Ω mil.sup.2 /ft______________________________________
Typical values for the remaining variables, relevant to the present invention and its purpose and typical environment, are:
TABLE 2______________________________________I.sub.p (programming current) = 1.0 amperest (programming time) = 100 millisecondsL (fuse length) = 0.10 inchesT.sub.a (ambient temperature) = 75° F.______________________________________
Because adjacent contact structure at the terminations 32 of the ends of fuse element 30 is at theoretical ambient temperature, the contacts act as heat sinks and absorb some of the heat from the fuse element during programming. Other matters affecting programming are dimensional variations in the diameter of the fuse elements from fabrication thereof, surface contamination thereon, and the fuse length between terminations.
It is believed that successful programming of a fuse shunt may be accomplished using fuse elements of the metals given above at the stated length and programming current and time at the following diameters:
D constantan=0.0015 inches
D aluminum=0.0007 inches
Unprogrammed (unopened) fuse elements at such diameters are believed will successfully carry in-service currents of 100 milliamperes.
To avoid interfering with the opening of the fuse elements, the element 30 should be preferably spaced away from the ends of the inner contact sections 16A,16B and also from any of the structure of the housing 12 or seals 22,26 which would act to dissipate heat otherwise needed to melt the fuse. The seals 22,26 serve to physically protect the fragile fuse elements 30, and contain any vapors give off during the fuse melting and avoid possible contamination of nearby circuitry or components outside of component 10. | 4y
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BACKGROUND
[0001] The invention relates to a decorative element according to the preamble of patent claim 1 .
[0002] Decorative elements are used today in many manners, thus in particular commercially and also privately for various decorative purposes. Thus, it is known in particular for Christmas stars and similar to attach wire pins through solder joints on a star formed base element, wherein pearls or similar decorative stones are lined up on the wire pins. This yields an individually configurable decorative element which can be used in many ways for various applications.
[0003] It is the object of the invention to provide a decorative element which facilitates variability and simultaneously also facilitates stable anchoring of the pins or threads supporting the pearls.
[0004] Furthermore, the decorative element shall also provide a good optically pleasing design or appearance and be suitable for many applications through its variability.
SUMMARY OF THE INVENTION
[0005] According to the invention a decorative element is provided with a base element configured as a support element with a number of wire-formed or thread-formed pins or also one or plural endless threads or wires for receiving ornamental elements or decorative elements, wherein the support element is configured in plural components, preferably in two components and thus configured from formed elements which are at least partially provided as a partial spherical elements or as partial rotational elements.
[0006] Bore holes are distributed over a circumference of the sphere or the circumference of the rotational element, thus in particular in longitudinal rows which are preferably arranged parallel to one another. The bore holes are provided for receiving pins. Thus, the formed elements can be spherical shells or flat shell formed elements so that for example a sphere can be formed when connecting two spherical shells, however a semi spherical element is generated when connecting a spherical shell with a flat shell with a level base as a placement surface, wherein the semi spherical element forms a semi sphere and can be placed on a horizontal surface.
[0007] Through the multi-component configuration of the element, in particular the two-shell configuration, a disengageable connection is feasible in a simple manner. This is useful in particular for a ball-formed element, in particular configured as a hollow element which is formed from two spherical shells or similar. These can be connected in a simple manner through a plug-in connection, a threaded connection or a bayonet closure. Also a threaded connection is advantageous, wherein the threaded connection is provided in sections over the entire circumference of the spherical shells. The multi-component arrangement and the disengageable configuration also increase variability because the formed element can be opened any time and the pins can be replaced or rearranged and attached, thus with the same length or with a different length. Thus, the pins or threads are run from the outside or the inside through bore holes that are distributed over the circumference of the ball shells and are preferably attached on the inside of the sphere through a pin button, a fold-over or a knot or a T-formed plug-in connection. Subsequently, the pearls can be lined up in any manner from the outside. At the free pin- or thread-end, the pearls are fixated through a knot, a fold, a ring or a thickening which is provided e.g. through upsetting. Optionally, in particular for a knotting of the threads or a fold-over of the pins for attachment at the inside of the sphere, the pearls can also be previously lined up on the pins or threads, thereafter the pins or threads are run from the outside through the bore hole and are then attached on the inside. In case the pin already has an attachment button at one end, running the pin through is performed from the inside of the sphere to the outside and subsequently the pearls or similar ornamental stones are threaded up from the outside.
[0008] In case of flexible threads made from plastic material the threads or plastic pins are stiffened by the threaded-on pearls which are closely adjacent to one another, so that the threads extend more or less in a straight line from the spherical shell in outward direction.
[0009] Instead of a wire pin or a thread also an endless thread can be used or also plural endless threads. In case of an endless thread the endless thread is inserted through a bore hole and attached therein as usual, thus through bending the wire over or through an applied crimping bead. On the section of the endless wire protruding outward beyond the spherical shell suitable decorative elements can be strung up. The protruding endless thread can then be bent into a loop. Optionally the free end can also be run inward through another bore hole and can thus be run outward through another bore hole forming additional loops and arranging decorative elements in rows. Also this yields broad variability.
[0010] In a particularly advantageous embodiment of the invention one of the spherical shells has a greater spherical section than the other shell, wherein the dividing plane of both spherical shells represents a secant plane through a sphere. When both spherical shells are connected with one another through a plug connector, thus a plug protrusion that can be integrally formed at one of the spherical shells, the spherical shells complement one another in a flush manner to form a spherical element. This embodiment yields the option that a row of bore holes with offset bore holes extends in a center of the sphere, this means along a central plane through the sphere which extends through the center of the sphere. This yields an appealing appearance with a center row of bore holes, wherein the other rows of bore holes are arranged parallel thereto. Thus, it is useful when the bore holes of adjacent rows of bore holes are offset relative to one another and thus respectively preferably centered with the bore holes of an adjacent row.
[0011] A plurality of bore holes is provided distributed over the ball or the spherical shell(s), wherein preferably each bore hole receives a pin, so that a large number of pins can be arranged distributed over the sphere or the spherical shell. When the pearls are then lined up on the pins or threads this yields a very decorative appearance. It is appreciated that pearls with different sizes and colors can be threaded onto the pins or threads in any manner.
[0012] In an advantageous embodiment of the invention, the two spherical shells have different sizes, wherein it is not excluded that both spherical shells are also as identically sized halves. In that both spherical shells are divided into halves with unequal sizes this yields a respective displacement of the connection seam or joint of the connection from the central plane of the sphere, wherein in a simple manner, also a row of bore holes and thus respective pins or threads for lining up the pearls in the central plane of the sphere, this means centered exactly about the center axis, can be provided. The other rows of bore holes are then arranged in parallel to the central plane defined by the center row of bore holes, in particular arranged in an identical manner so that an even structure of the pins or threads and of the pearls arranged thereon is provided about the sphere. In the context of a uniform structure of this type, the bore holes are arranged for each series of bore holes with uniform circumferential distance. The bore holes of adjacent rows of bore holes can then be aligned offset from these bore holes or identical with these bore holes. Thus, it is helpful when adjacent rows of bore holes are arranged concentric with one another, which however is not mandatory.
[0013] Preferably, the size of the sphere is in a diameter range of 1 to 10 cm, in particular 2 to 5 cm. Thus, bore holes with a number between 10 and 100, preferably 20 to 72, particularly preferably 34 to 60, can be provided per sphere.
[0014] The pins are advantageously provided in the form of wires, in particular metal wires, in particular steel wires. The pins, however, can also be made from plastic material. Instead of stiff pins, also textile or plastic threads can be used, in particular nylon threads. Since the threads or pins are attached at the spherical shell, a self-acting stiffening of the threads is provided when the pearls are tightly spaced, so that the threads remain raised. Thus, it is advantageous overall when the pins or threads are arranged perpendicular to a plane contacting the respective bore hole in a tangential manner.
[0015] The spherical shells themselves can be made from metal, in particular brass, or from plastic material. Furthermore, spherical shells can be colored or coated, in particular with gold-, silver- or copper-colored layer. The pins can either extend with identical length from the spherical shell in outward direction or with different lengths, wherein the pin size is in a range of 1 to 7 cm, preferably 1 to 5 cm, particularly preferably between 1.5 to 3.5 cm. The same applies for the thread length respectively computed extending from the outer spherical surface.
[0016] The attachment of the pins is provided through a pinhead in the interior of the spherical shell, whose dimensions are larger than the dimensions of the bore hole. Alternatively, the pin can also be bent or upset in order to attach the pin at the spherical shell. In case of threads made from textile material or plastic material, the attachment is provided through knots or in that the threads have a T-formed head. The thread can then be threaded in through the T-piece. The T-head then fixates the thread in outward direction so that pearls are applied from the outside and the pearls can then be fixated through a knot connection.
[0017] In case of a flat shell that is attachable at a spherical shell and that has a flat base various functional elements can be attached thereon which increases variability. Particularly suitable are an ear clip, a broach pin, an ear pin, hair clips, hair clamps, finger rings, hat pins, and similar. At spherical shells or at the flat shells also animal figures or Christmas angels can be attached, so that indefinite variability is provided. The invention is particularly suitable for an arts and crafts system, wherein the spherical shells and a flat shell are provided as base elements, which are connectable with one another, wherein the spherical shells are configured with respective bore holes for receiving pins, threads, or endless threads or endless wires. The flat shell can be used as stand element or for attaching functional elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] Subsequently embodiments of the invention are described with reference to the drawing, wherein:
[0019] FIG. 1 illustrates a perspective schematic view of a sphere formed from two spherical shells;
[0020] FIG. 2 illustrates a schematic partial view for illustrating a pin;
[0021] FIG. 3 illustrates an analogous alternative view of FIG. 1 ; and
[0022] FIG. 4 illustrates an embodiment of a thread with a T-formed head piece for attachment.
[0023] FIG. 5 illustrates another embodiment of a spherical decorative element according to the invention;
[0024] FIG. 6 illustrates a view of the sphere of FIG. 5 in an open position of both spherical shells;
[0025] FIG. 7 illustrates another embodiment of a spherical shell configured as a suspended element;
[0026] FIG. 8 illustrates another embodiment of a spherical shell configured as a standing decorative element or a table decorative element;
[0027] FIG. 9 illustrates a side view of another embodiment according to the invention;
[0028] FIG. 10 illustrates another embodiment of the invention configured as a napkin ring or table card holder;
[0029] FIG. 11 illustrates another embodiment according to the invention configured as an ear clip;
[0030] FIG. 12 illustrates another embodiment of a pin.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] FIG. 1 illustrates a spherical element 1 configured as a sphere which is formed from two shells 3 and 5 . Thus, the shell 3 is configured as a ball-formed scraper is configured slightly smaller than the spherical shell 5 also configured as a ball-formed scraper. The two shells 3 and 5 can either be connected with one another through an insertable connection or a threaded connection. For illustration purposes, FIG. 1 illustrates a plug-in socket 7 which is sized smaller relative to the rest of the spherical shell 3 , wherein the spherical shell 3 is insertable into the spherical shell 5 through the plug-in socket. Therefore, the plug-in connection is a fitted connection which is fixated, however, also disengageable under tension. Alternatively, and this is schematically illustrated in FIG. 1 , the connection of both shells 3 and 5 can be provided through a threaded connection. Thus, one or plural threads can be provided over the entire circumference of the socket 7 which is schematically indicated by the reference numeral 9 . Respective thread turns or a respective thread is then also provided in the edge portion of the spherical shell 5 as indicated at 11 . Instead of a circumferential thread turn, thread turns can also be provided in sections as apparent from FIG. 1 for both spherical shells 3 and 5 . Alternatively the interconnection of both spherical shells can also be provided through one or plural bayonet closures which are not illustrated.
[0032] It is apparent that each spherical shell is provided with a plurality of bore holes 13 which extend through the spherical shell. Thus, it is helpful that a row of bore holes is provided in the central plane of the sphere which is designated as 15 . The row of bore holes is also illustrated in dashed lines which only serve illustration purposes. In the illustrated embodiment, additional rows of bore holes are provided which are configured at a distance from the row of bore holes 15 that are configured centered in the center plane and which also include a number of bore holes 13 that are preferably arranged at uniform distances from another. However, it is not mandatory that the bore holes are arranged at uniform distances from one another; however an even structure is generated for an arrangement with even distances. Optionally, the bore holes of adjacent rows of bore holes can also be arranged offset from one another.
[0033] Through these bore holes 13 , as described best with reference to FIGS. 2 and 3 , a pin 17 is inserted. The pin 17 illustrated in FIG. 2 includes a thickened head 19 at its inner end, wherein the thickened head has at least one dimension which is greater than the diameter of the associated bore hole 13 . Thus, the pin 17 is inserted from the inside to the outside through the bore hole 13 until the pinhead 19 contacts the inner surface of the spherical shell. Then, pearls 21 are lined up from the outside which can have identical sizes or completely different sizes and can have identical or different shapes. After the lineup of the pearls 21 , a fixation is provided at the protruding free-end of the pin 17 through forming an eyelet, wherein the eyelet 23 is apparent from FIG. 2 and can also be used as a hanger for another row of pearls 25 . For better illustration, the pearls 21 are represented as transparent pearls so that the pin 17 is visible. This also applies for FIGS. 1 , 2 and 3 .
[0034] In the embodiment, according to FIG. 3 , mounting the pin is provided at the interior of the spherical shell through folding the pin over, wherein the fold-over is designated as 25 . Fixating the lined up pearls 21 is in turn provided through a fold-over 25 at the free end of the pin. The pin is configured as a metal wire, in particular as a steel pin.
[0035] FIG. 4 alternatively illustrates a plastic material thread made from nylon which is configured with a T-piece 27 for attachment at its lower end for insertion into a bore hole and attachment of the thread at the spherical shell. Subsequently, the pearls not illustrated in FIG. 4 , are lined up and a fixation of the non-illustrated pearls is provided at the thread 29 through a knot 31 .
[0036] The variability of the decorative element is rather large since the pins do not have to be provided in each bore hole, the pins or threads can be configured with different lengths and also a different number of pearls with different size and shape can be provided which is at the discretion of the user of the decorative element. It is helpful that the decorative element is configured in a very simple manner, can be opened and replaced with new pins or threads any time so that the design can be changed at will. The decorative element is suited in particular for arts and crafts and is therefore highly suitable in particular for school applications. The decorative element in do it yourself construction also appeals to all age groups and is also suitable for arts and crafts applications in assisted living facilities. It is advantageous that the same spherical element can be used for different decorative arrangements. This is caused by high variability, the simple assembly of the pins and threads and the simple lineup of the pearls and the simple opening and closing of the spherical element. A spherical element in the context of this application means that the element does not have to be a strictly geometrical sphere, though the sphere actually has exactly spherical shape in a preferred embodiment.
[0037] The embodiment illustrated in FIGS. 5 and 6 is configured from two spherical shells 3 , 5 . As illustrated in FIG. 6 one of the spherical shells, herein the spherical shell 5 is configured with a larger sphere section than the other spherical shell 3 according to FIG. 6 . The spherical shell 5 like the embodiment according to FIG. 1 has a plug in section 7 which is configured offset inward through a circumferential annular shoulder 30 relative to the larger sphere section. This plug in section represents a plug connector through which the spherical shell 5 can be attached at the other opposite spherical shell 3 . The spherical shell 3 certainly includes a respective receiving mechanism corresponding to the plug in recess 7 , thus as already described in a context with the embodiment according to FIG. 1 .
[0038] As apparent from FIG. 6 for the right spherical shell 5 a thread section 31 is arranged on the plug in section 7 , wherein a second respective thread section is provided on an opposite side of the plug in section 7 which, however, is not evident from the drawing figure. Thus, two opposite thread sections 31 are provided for the illustrated embodiment at the plug in section 7 . Respective threaded grooves which correspond with these thread sections are configured at the opposite spherical shell 3 . The invention is certainly not limited to two thread sections which are only exemplary. Three or four or more thread sections can be distributed over the circumference which is eventually also a function of the size of the decorative element.
[0039] Both spherical shells form a sphere in combination along a dividing plane 32 or a dividing line 32 which is eventually formed by the annular shoulder 30 . The dividing plane 32 represents a secant plane through the spherical element, this means that the dividing plane or the circumferential edges of the spherical shells which contact one another when assembling the shells are generated by an intersection of the sphere with a plane which goes through the sphere but not through the center of the sphere so that both spherical shells complement one another to form a sphere after connecting through the plug in section 7 and the thread sections.
[0040] This embodiment has the option that a row 33 with bore holes is on a central plane after connecting both spherical shells, wherein the central plane intersects with the spherical element and extends through the center of the sphere as clearly apparent from FIG. 5 . This means the dividing line 32 is offset to the right relative to a central plane through the sphere center so that the row 33 with offset bore holes 13 can be arranged along an intersection plane with the sphere which is formed by the central plane through the center of the sphere.
[0041] As apparent from FIGS. 5 and 6 additional rows of bore holes 34 and 36 are arranged on this sphere and thus in an arrangement that is parallel to the row of bore holes 33 and also to the row of bore holes of the opposite shell. The rows of bore holes 13 of adjacent rows of bore holes are thus offset from one another with parallel centers as apparent from the view of the right spherical shell in FIG. 6 . This embodiment is useful but not the only one. Various embodiments are feasible.
[0042] FIG. 7 illustrates the spherical shell which is illustrated in FIG. 6 on the left side and which can be used as a suspended decorative element. For this purpose the spherical shell 3 can be provided at the secant dividing line 32 for example with an inward oriented fold over which forms a suspension eyelet through which the spherical shell 3 can be suspended at a wall.
[0043] The embodiment according to FIG. 8 uses the spherical shell 5 that is apparent from FIG. 6 as a standard element so that FIGS. 7 and 8 illustrate that the individual spherical shells can also be used as separately standing decorative elements or suspended decorative elements.
[0044] It is appreciated that also the embodiment according to these figures has pins or threads run through the bore hole 13 and the pins or threads are attached at a spherical shell as described already with reference to the embodiment according to FIGS. 1-4 .
[0045] FIG. 9 illustrates another embodiment in which a spherical shell 5 , thus the spherical shell illustrated in FIGS. 5 and 6 that is provided with a plug in section 7 is used. This spherical shell can be analogously connected with a shell element 40 with a flat base element 41 . Thus, FIG. 9 illustrates the threaded groove in dashed lines on the left side which threaded groove interacts with the thread section 31 formed on the plug in section 7 for attaching both elements at one another. Connecting the shell formed component with the spherical shell 5 yields a decorative element which can be used on a horizontal surface as standing decorative element. This yields a semi sphere instead of a total sphere according to the illustration in FIG. 1 .
[0046] FIG. 10 illustrates variations of the embodiment according to FIG. 9 in turn in a schematic view. Thus, a napkin ring 42 is attached at a base 41 of the shell 40 and thus in particular through a threaded bolt 43 . On the opposite side at the spherical shell 5 a pin 44 is run through the top most bore hole and attached at the spherical shell wherein the pin is bent into a spiral shape 46 in its upper most portion 45 , wherein the spiral shape 46 is used as a receiving element for table cards or name cards which are insertable therein. Alternatively, however, also other configurations are feasible in that for example the spherical shell 5 is integrally configured with the shell 40 as a receiver for a candle holder, wherein a candle holder only has to be attached at the spherical shell. For this purpose only a T-pin has to be inserted through the center bore hole in an upper portion of the spherical shell where a candle holder is then attached in a suitable manner. Thus, a pin run through at an upper end of the spherical shell can also be used as an insertion pin for inserting a candle, so that dedicated candle holders are not required. The remaining bore holes can then be used for receiving various decorative elements through the inserted pins.
[0047] In the embodiment according to FIG. 11 a known ear clip 47 is attached at the base 41 of the shell 40 , thus through a small plate 48 which is for example glued together with the base 41 of the shell 40 or can be attached in another suitable manner, thus screwed together. The shell 40 is then connected with a spherical shell 5 so that a piece of ear jewelry is provided which can be configured in any manner. Instead of an ear clip also ear plugs or hair clips, finger rings, hat pins and similar can be attached which shows the variability of the system.
[0048] As stated regarding the embodiment according to FIG. 11 instead of a hair clip also another functional element can be attached, in particular a broach pin can be soldered on or glued on so that the decorative element can be pinned to a garment. In the embodiment according to
[0049] FIG. 11 , the illustrated small plate 48 can also be attached at the shell 40 through a central threaded connection as indicated in FIG. 11 . Thus, different attachment options are conceivable that are within the skill of a person skilled in the art.
[0050] Instead of pins or threads that are run through the bore holes also commercially available endless wires can be used which are run from an inside through one of the bore holes, wherein the beginning of the wire is fixated through annular bending or through attachment of a so called crimp bead. The endless wire that is run through is then formed in a loop or differently and can be decorated with decorative elements. Thus, the endless wire can also be run through other bore holes and can be pulled out again at another location, wherein in turn loop formation is feasible and decorative elements can be put on the wire. This yields a plurality of different decorative and design options.
[0051] For example the spherical shells can also be used for curtain decorations. For a curtain tie down whose ends are often provided with commercially available tassels as a completion the ends can also be decorated with the two spherical halves. Thus small magnets provided with small individual bore holes can be attached in each of the half spheres in the cavities of the two half spheres. The half spheres in turn are attached at both ends of the curtain tie downs and are assembled through the magnetic effect until a voluntarily provided separation occurs and can thus be used as decorative curtain tie downs.
[0052] The spherical shells or spherical elements with the pins, threads or endless wires can also be used in combination with plant assemblies. For example a plant assembly can be attached through pins at an approximately central portion of the spherical shell, whereas one or plural endless wires can be run through the adjacent bore holes that do not have to be used for the plant assembly and wherein a decorative effect is achieved through forming loops and stringing up decorative elements on the endless wires wherein the decorative effect adds to the appearance of the plant assembly.
[0053] FIG. 12 illustrates an embodiment of a wire pin 50 with a circular cross section which includes a T formed attachment element at its lower end. Above the T-head a flat rectangular element 52 is produced through flattening the pin with circular cross section wherein the flat element has sharp edges 53 on both sides. The flat element with edges thus advantageously extends over a length which corresponds approximately to the thickness of the spherical shell. This can be for example a length of 4 mm. This yields sharp cutting edges on both sides of the flat element. This has the effect that the pin after loosely running the circular pin through the bore hole the pin is effectively anchored in the bore hole through the flat element with edges so that any movement of the pin attached in the spherical shell can be avoided in a simple manner. Thus, the diameter of the wire pin 50 is adapted to the diameters of the bore hole in the spherical shells so that the desired attachment in the bore hole is achieved through a pressed flat element 42 with edges. This yields a very simple and secure permanent fixation of the wire pins in the spherical shell. | 4y
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BACKGROUND OF THE INVENTION
This invention relates to the storage of liquid radioactive material.
The term "liquid radioactive material" as used in this specification includes within its scope solutions and slurries.
Such solutions and slurries may arise during the reprocessing of irradiated nuclear fuel. When a nuclear fuel has been irradiated in a nuclear reactor it is normally reprocessed to separate uranium and plutonium from the fission products. The fission products are highly radioactive and have to be stored for very long periods. One method for the long term storage of fission products is to store them as solutions or slurries in large tanks fitted with cooling coils to remove the decay heat and with means for circulating the fission product solution or slurry within the tank. However it is difficult to ensure that sufficient circulation occurs within the large volume of liquid in the tank to prevent the accumulation of sediment on the tank walls and on the cooling coils which tends to reduce the efficiency of the cooling. As a safety measure there must be spare tanks available to which to transfer the fission product solution or slurry should any defect become apparent in the original tank. The capital investment in such storage tanks is large and it is therefore desirable to reduce the number of spare tanks which have to be provided.
SUMMARY OF THE INVENTION
According to the present invention a storage installation for liquid radioactive material comprises pipe circuits containing the liquid radioactive material, means for circulating the liquid radioactive material around the pipe circuits and means for circulating a liquid cooling medium over the external surface of the pipe circuits.
The liquid cooling medium may be in a tank and the pipe circuits may be immersed in the cooling medium in the tank. Alternatively the liquid cooling medium may be passed through the annular gap between co-axial pipes the inner one of which contains the liquid radioactive material.
The liquid cooling medium may be circulated from the tank or the annular gap between the co-axial pipes of the alternative pipe circuits described above to a heat exchanger by means of pumps. Should the pumps cease to operate the temperature of the liquid radioactive material within the pipe circuits will rise because of the cessation of flow of the cooling medium. It is undesirable that the liquid radioactive material should boil within the pipe circuits. Additionally, as the temperature of the liquid radioactive material rises the rate of corrosion of the pipe circuits by the liquid material therein also rises. To prevent boiling of the liquid radioactive material and to minimise the corrosion which could occur during a malfunction of the cooling medium circulating pump secondary cooling systems are preferably provided.
In the case of pipe circuits which are immersed in the cooling medium in a tank a condenser may be provided on the tank to prevent loss of any cooling medium should the temperature of the cooling medium be raised to a point at which evaporation of the cooling medium is occurring to a significant extent. The condenser is preferably an air condenser requiring no power input for its operation and it should be of such a size that no loss of cooling medium occurs even if the cooling medium boils.
The said means for circulating the liquid radioactive material around the pipe circuits may comprise fluidic pump means, and such means may be operated by a pulsed-liquid column controlled by air pressure.
The cooling medium may be water but if a tank is used which is fitted with a reflux condenser as described in the preceding paragraph a cooling medium having a boiling point in the range 60°-80° C. is preferred so that the temperature of the pipe circuits does not rise to a point where the corrosion rate is excessive. Examples of cooling media which may be used include methanol, isopropanol, methylene chloride, carbon tetrachloride and other halogenated hydrocarbons such as those sold under the trade name Freon. In a situation where the pumps circulating the cooling medium are not operating the latent heat of evaporation extracted from the pipe circuits as the cooling medium boils prevents excessive heating in the pipe circuits.
DESCRIPTION OF THE DRAWINGS
The invention is illustrated by the following description of storage installations for liquid radioactive waste, given by way of example only. The description has reference to the accompanying drawings in which:
FIG. 1 is a diagrammatic representation of a storage installation for liquid radioactive waste and
FIG. 2 is a diagrammatic representation of a further storage installation for liquid radioactive waste showing a cooling system for the circulating liquid cooling medium in normal operation and a secondary cooling system.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, the installation illustrated therein comprises a tank 1 containing a liquid cooling medium which may be water and which is circulated by pumps (not shown) through heat exchangers (not shown) to remove the decay heat of the radioactive material. Five pipe circuits 2 (of which only one is shown) are immersed side-by-side in the cooling medium in the tank 1. Each pipe circuit 2 is manufactured from seamless stainless steel tube and is provided with a side arm 3 which has a pulsing chamber 4. The liquid in the pulsing chamber is caused to oscillate by air-flow controllers 5, 6 which alternatively introduce air into the pulsing chamber 4 and withdraw it. The oscillating motion of the liquid in the pulsing chamber is converted by a fluidic pump 7 into a circulatory motion around the pipe circuit 2 in the direction of the arrows. The fluidic pump 7 operates on the pulsed fluid diode principle and has no moving parts within the tank 1. A further side arm 8 extends from the pipe circuit to a point above the liquid level in the tank and this further side arm is used for filling and emptying the pipe circuit 2, for removing samples of the liquid for analysis and for providing access for instruments to be lowered into the liquid, for example to measure the temperature of the liquid.
Conveniently the pipe circuit 2 shown in the figure may be manufactured from 10" diameter seamless stainless steel tube and may contain 450 feet of such tube. A pipe circuit so formed would have a capacity of 7 cubic meters.
The pipe circuits 2 are placed in the tank 1 in close packed array to maximise the number of pipe circuits in the tank. Pipe circuits of different shapes, sizes and pipe diameters may be utilised within a tank to maximise the utilisation of the space within the tank.
In use the fluidic pump 7 circulates the liquid radioactive material round the pipe circuit 2. This circulation minimises the possibility of sediment depositing on the walls of the coil which reduces the heat transfer properties of the walls. If water is used as the cooling medium in the tank, it is chemically treated to ensure minimum corrosion of the pipe circuits and tank. The cooling liquid is preferably monitored to detect any increase in radioactivity level which would indicate that a pipe circuit was leaking. In the event that one pipe circuit in a tank leaks only the radioactive material in that circuit has to be transferred to alternative storage facilities. Thus the amount of spare storage capacity which has to be provided is less than is required for storage in tanks. If one pipe circuit leaks the remaining pipe circuits can remain in the tank and the faulty circuit can be isolated or replaced. Thus the failure of one pipe circuit does not necessitate abandoning the tank and its associated shielding whereas a failure in the tank used for tank storage of radioactive liquids may mean that the tank and the shielding surrounding it become heavily contaminated and cannot be re-used.
An alternative embodiment may be manufactured from tubing having two co-axial tubes. The liquid radioactive material is stored in the inner tube and the cooling medium is circulated through the annular gap between the tubes. The pipe circuit formed from co-axial tubes may be placed in a tank, for example as shown in FIG. 1, and may be further cooled by the circulation of a liquid medium such as water in the tank.
Referring now to FIG. 2 a tank 1 and a pipe circuit 2 are shown. The pipe circuit is similar to that shown in FIG. 1 and the same reference numerals are used to identify the parts thereof. In normal use the cooling medium is withdrawn from the tank 1 through a pipe 10 and passed through a heat exchanger 11 by a pump 12 and returned to the base of the tank 1. The heat exchanger is cooled by water which is circulated by a pump 13 and which is passed down a cooling tower 14. The tank 1 is fitted with an air-cooled condenser 15 to condense any vapour evaporating from the cooling medium and return it to the tank.
In the event of a malfunction of any of the components of the cooling system which prevent or reduce the circulation of the cooling medium the decay heat emitted by the liquid radioactive material in the pipe circuit 2 will raise the temperature of the liquid material in the pipe circuit and of the cooling medium in the tank. If the rise in temperature proceeds for a sufficient length of time the temperature of the cooling medium will rise to its boiling point. The cooling medium then boils and the vapour condenses in the condenser 15 and is returned to the tank 1. As the liquid medium boils, its latent heat of evaporation is extracted from the pipe circuits and the temperature in the pipe circuits will be maintained at a value similar to the boiling point of the medium. The use of a cooling medium having a boiling point in the range 60°-80° C. ensures that the temperature within the pipe circuits does not rise to the boiling point of the liquid radioactive material or to a point where the corrosion rate of the pipe circuits by the liquid radioactive material becomes excessive. In normal use the circulating cooling medium ensures that the temperature of the liquid radioactive material is kept as low as possible and it is only in the situation where the normal circulatory cooling is not operative that the secondary cooling system utilising the condenser 15 is operative.
The cooling medium surrounding the pipe circuits in the present invention acts as an additional barrier facilitating the containment of any leakage which may occur from the pipe circuits. Storage in the pipe circuits rather than in tanks facilitates criticality control of liquids containing plutonium as the pipe circuits can be designed to be safe by geometry. The construction of storage installations according to the present invention is facilitated as the pipe circuits can be tested before being installed. The circulation of the liquid radioactive material and of the cooling medium and the large surface area of the pipe circuits facilitates heat transfer from the liquid radioactive material to the cooling medium. | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to a new and distinctive corn inbred line, designated LH185. There are numerous steps in the development of any novel, desirable plant germplasm. Plant breeding begins with the analysis and definition of problems and weaknesses of the current germplasm, the establishment of program goals, and the definition of specific breeding objectives. The next step is selection of germplasm that possess the traits to meet the program goals. The goal is to combine in a single variety or hybrid an improved combination of desirable traits from the parental germplasm. These important traits may include higher yield, resistance to diseases and insects, better stalks and roots, tolerance to drought and heat, and better agronomic quality.
Choice of breeding or selection methods depends on the mode of plant reproduction, the heritability of the trait(s) being improved, and the type of cultivar used commercially (e.g., F 1 , hybrid cultivar, pureline cultivar, etc.). For highly heritable traits, a choice of superior individual plants evaluated at a single location will be effective, whereas for traits with low heritability, selection should be based on mean values obtained from replicated evaluations of families of related plants. Popular selection methods commonly include pedigree selection, modified pedigree selection, mass selection, and recurrent selection.
The complexity of inheritance influences choice of the breeding method. Backcross breeding is used to transfer one or a few favorable genes for a highly heritable trait into a desirable cultivar. This approach has been used extensively for breeding disease-resistant cultivars. Various recurrent selection techniques are used to improve quantitatively inherited traits controlled by numerous genes. The use of recurrent selection in self-pollinating crops depends on the ease of pollination, the frequency of successful hybrids from each pollination, and the number of hybrid offspring from each successful cross.
Each breeding program should include a periodic, objective evaluation of the efficiency of the breeding procedure. Evaluation criteria vary depending on the goal and objectives, but should include gain from selection per year based on comparisons to an appropriate standard, overall value of the advanced breeding lines, and number of successful cultivars produced per unit of input (e.g., per year, per dollar expended, etc.).
Promising advanced breeding lines are thoroughly tested and compared to appropriate standards in environments representative of the commercial target area(s) for three years at least. The best lines are candidates for new commercial cultivars; those still deficient in a few traits are used as parents to produce new populations for further selection.
These processes, which lead to the final step of marketing and distribution, usually take from eight to 12 years from the time the first cross is made. Therefore, development of new cultivars is a time-consuming process that requires precise forward planning, efficient use of resources, and a minimum of changes in direction.
A most difficult task is the identification of individuals that are genetically superior, because for most traits the true genotypic value is masked by other confounding plant traits or environmental factors. One method of identifying a superior plant is to observe its performance relative to other experimental plants and to a widely grown standard cultivar. If a single observation is inconclusive, replicated observations provide a better estimate of its genetic worth.
The goal of plant breeding is to develop new, unique and superior corn inbred lines and hybrids. The breeder initially selects and crosses two or more parental lines, followed by repeated selfing and selection, producing many new genetic combinations. The breeder can theoretically generate billions of different genetic combinations via crossing, selfing and mutations. The breeder has no direct control at the cellular level. Therefore, two breeders will never develop the same line, or even very similar lines, having the same corn traits. Each year, the plant breeder selects the germplasm to advance to the next generation. This germplasm is grown under unique and different geographical, climatic and soil conditions, and further selections are then made, during and at the end of the growing season. The inbred lines which are developed are unpredictable. This unpredictability is because the breeder's selection occurs in unique environments, with no control at the DNA level (using conventional breeding procedures), and with millions of different possible genetic combinations being generated. A breeder of ordinary skill in the art cannot predict the final resulting lines he develops, except possibly in a very gross and general fashion. The same breeder cannot produce the same line twice by using the exact same original parents and the same selection techniques. This unpredictability results in the expenditure of large research monies to develop a superior new corn inbred line.
The development of commercial corn hybrids requires the development of homozygous inbred lines, the crossing of these lines, and the evaluation of the crosses. Pedigree breeding and recurrent selection breeding methods are used to develop inbred lines from breeding populations. Breeding programs combine desirable traits from two or more inbred lines or various broad-based sources into breeding pools from which inbred lines are developed by selfing and selection of desired phenotypes. The new inbreds are crossed with other inbred lines and the hybrids from these crosses are evaluated to determine which have commercial potential.
Pedigree breeding is used commonly for the improvement of self-pollinating crops or inbred lines of cross-pollinating crops. Two parents which possess favorable, complementary traits are crossed to produce an F 1 . An F2 population is produced by selfing one or several F 1 's or by intercrossing two F 1 's (sib mating). Selection of the best individuals is usually begun in the F 2 population; then, beginning in the F 3 , the best individuals in the best families are selected. Replicated testing of families, or hybrid combinations involving individuals of these families, often follows in the F 4 generation to improve the effectiveness of selection for traits with low heritability. At an advanced stage of inbreeding (i.e., F 6 and F 7 ), the best lines or mixtures of phenotypically similar lines are tested for potential release as new cultivars.
Mass and recurrent selections can be used to improve populations of either self- or cross-pollinating crops. A genetically variable population of heterozygous individuals is either identified or created by intercrossing several different parents. The best plants are selected based on individual superiority, outstanding progeny, or excellent combining ability. The selected plants are intercrossed to produce a new population in which further cycles of selection are continued.
Backcross breeding has been used to transfer genes for a simply inherited, highly heritable trait into a desirable homozygous cultivar or inbred line which is the recurrent parent. The source of the trait to be transferred is called the donor parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent. After the initial cross, individuals possessing the phenotype of the donor parent are selected and repeatedly crossed (backcrossed) to the recurrent parent. The resulting plant is expected to have the attributes of the recurrent parent (e.g., cultivar) and the desirable trait transferred from the donor parent.
Descriptions of other breeding methods that are commonly used for different traits and crops can be found in one of several reference books (e.g., Allard, 1960; Simmonds, 1979; Sneep et al., 1979; Fehr, 1987).
Proper testing should detect any major faults and establish the level of superiority or improvement over current cultivars. In addition to showing superior performance, there must be a demand for a new cultivar that is compatible with industry standards or which creates a new market. The introduction of a new cultivar will incur additional costs to the seed producer, the grower, processor and consumer; for special advertising and marketing, altered seed and commercial production practices, and new product utilization. The testing preceding release of a new cultivar should take into consideration research and development costs as well as technical superiority of the final cultivar. For seed-propagated cultivars, it must be feasible to produce seed easily and economically.
Once the inbreds that give the best hybrid performance have been identified, the hybrid seed can be reproduced indefinitely as long as the homogeneity of the inbred parent is maintained. A single-cross hybrid is produced when two inbred lines are crossed to produce the F progeny. A double-cross hybrid is produced from four inbred lines crossed in pairs (AxB and CxD) and then the two F 1 hybrids are crossed again (AxB) x (CxD). Much of the hybrid vigor exhibited by F 1 hybrids is lost in the next generation (F 2 ). Consequently, seed from hybrid varieties is not used for planting stock.
Corn is an important and valuable field crop. Thus, a continuing goal of plant breeders is to develop stable, high yielding corn hybrids that are agronomically sound. The reasons for this goal are obviously to maximize the amount of grain produced on the land used and to supply food for both animals and humans. To accomplish this goal, the corn breeder must select and develop corn plants that have the traits that result in superior parental lines for producing hybrids.
SUMMARY OF THE INVENTION
According to the invention, there is provided a novel inbred corn line, designated LH185. This invention thus relates to the seeds of inbred corn line LH185, to the plants of inbred corn line LH185 and to methods for producing a corn plant produced by crossing the inbred line LH185 with itself or another corn line. This invention further relates to hybrid corn seeds and plants produced by crossing the inbred line LH185 with another corn line.
DEFINITIONS
In the description and tables which follow, a number of terms are used. In order to provide a clear and consistent understanding of the specification and claims, including the scope to be given such terms, the following definitions are provided:
Predicted RM. This trait for a hybrid, predicted relative maturity (RM), is based on the harvest moisture of the grain. The relative maturity rating is based on a known set of checks and utilizes conventional maturity systems such as the Minnesota Relative Maturity Rating System.
MN RM. This represents the Minnesota Relative Maturity Rating (MN RM) for the hybrid and is based on the harvest moisture of the grain relative to a standard set of checks of previously determined MN RM rating. Regression analysis is used to compute this rating.
Yield (Bushels/Acre). The yield in bushels/acre is the actual yield of the grain at harvest adjusted to 15.5% moisture.
Moisture. The moisture is the actual percentage moisture of the grain at harvest.
GDU Silk. The GDU silk (=heat unit silk) is the number of growing degree units (GDU) or heat units required for an inbred line or hybrid to reach silk emergence from the time of planting. Growing degree units are calculated by the Barger Method, where the heat units for a 24-hour period are: ##EQU1## The highest maximum used is 86° F. and the lowest minimum used is 50° F. For each hybrid, it takes a certain number of GDUs to reach various stages of plant development. GDUs are a way of measuring plant maturity.
Stalk Lodging. This is the percentage of plants that stalk lodge, i.e., stalk breakage, as measured by either natural lodging or pushing the stalks determining the percentage of plants that break off below the ear. This is a relative rating of a hybrid to other hybrids for standability.
Root Lodging. The root lodging is the percentage of plants that root lodge; i.e., those that lean from the vertical axis at an approximate 30° angle or greater would be counted as root lodged.
Plant Height. This is a measure of the height of the hybrid from the ground to the tip of the tassel, and is measured in centimeters.
Ear Height. The ear height is a measure from the ground to the ear node attachment, and is measured in centimeters.
Dropped Ears. This is a measure of the number of dropped ears per plot, and represents the percentage of plants that dropped an ear prior to harvest.
DETAILED DESCRIPTION OF THE INVENTION
Inbred corn line LH185 is a yellow dent corn with superior characteristics, and provides an excellent parental line in crosses for producing first generation (F 1 hybrid corn.
LH185 was developed from the single cross LH59 ×LH123Ht by selfing and using the pedigree system of plant breeding. Selfing and selection were practiced within the above F 1 cross for seven generations in the development of LH185.
Some of the criteria used to select ears in various generations include: yield, stalk quality, root quality, disease tolerance, late plant greenness, late season plant intactness, ear retention, pollen shedding ability, silking ability, and corn borer tolerance. During the development of the line, crosses were made to inbred testers for the purpose of estimating the line's general and specific combining ability, and evaluations were run by the Williamsburg, Iowa Research Station. The inbred was evaluated further as a line and in numerous crosses by the Williamsburg and other research stations across the Corn Belt. The inbred has proven to have a very good combining ability in hybrid combinations.
The inbred has shown uniformity and stability for all traits, as described in the following variety description information. It has been self-pollinated and ear-rowed a sufficient number of generations, with careful attention to uniformity of plant type to ensure homozygosity and phenotypic stability. The line has been increased both by hand and sibbed in isolated fields with continued observation for uniformity. No variant traits have been observed or are expected in LH185.
Inbred corn line LH185 has the following morphologic and other characteristics (based primarily on data collected at Williamsburg, Iowa):
VARIETY DESCRIPTION INFORMATION
A. Maturity
INBRED=LH185
Best Adapted For: Northcentral Regions of the Corn Belt
Heat Unit Silk: 1455 ##EQU2##
B. Plant Characteristics
Plant height (to tassel tip): 163 cm.
Length of top ear internode: 13 cm.
Number of tillers: None
Cytoplasm type: Normal
Number of ears per stalk: Single
Ear height (to base of top ear): 35 cm.
C. Leaf
Color: 7.5 GY 3/4 Munsell Color Charts for Plant Tissues
Angle from stalk: 30°-60°
Marginal waves: Few
Width (widest point of ear node leaf): 8 cm.
Number of leaves (mature plants): 12
Sheath pubescence: Light
Longitudinal creases: Few
Length (ear node leaf): 59 cm.
D. Tassel
Number of lateral branches: 4
Branch angle from central spike: 30°-40°
Pollen shed: Medium
Anther color: Yellow
Glume color: Green
Peduncle length (top leaf to basal branch): 03 cm.
E. Ear (Husked Ear Data Except When Stated Otherwise)
Length: 12 cm.
Midpoint diameter: 35 ram.
Weight: 38 gm.
Number of Kernel rows: 10
Silk color: Green
Husk color (fresh): Light green
Husk color (dry): Buff
Husk extension: Long (8-10 cm.)
Shank length: 05 cm.
Shank (no. of internodes): 8
Taper of Ear: Slight
Husk leaf: Medium--8-15 cm.
Position of shank (dry husks): Upright
F. Kernel (Dried)
Size (from ear midpoint)
Length: 11 mm.
Width: 10 mm.
Thickness: 4 mm.
Shape grade (% rounds): 40-60
Pericarp color: Bronze
Aleurone color: White
Endosperm color: Yellow
Endosperm type: Normal starch
Gm Weight/100 seeds (unsized): 27 gm.
G. Cob
Diameter at midpoint: 25 mm.
Strength: Strong
Color: White
LH185 is a line developed from the parents LH59 and LH123. LH185 as a plant resembles more closely the LH123 parent except LH185 is a shorter plant with a very low ear placement. LH185 is earlier flowering than LH123. In hybrid combination, the ear type is somewhat like LH123 (relatively short and girthy).
LH185 has a much greater area of adaptability than LH123 had when LH123 was used commercially. One particular agronomic trait that increases LH185's area of adaptation over LH 123 is LH 185's improved resistance to summer stalk brittling. This was a particularly limiting problem that was characteristic of LH123 in a number of hybrids.
LH185 has very good general combining ability. LH185's yield to moisture ratio is improved over either parent.
TABLES
In the tables that follow, the traits and characteristics of inbred corn line LH185 are given in hybrid combination. The data collected on inbred corn line LH185 is presented for the key characteristics and traits. The tables present yield test information about LH185. LH185 was tested in several hybrid combinations at numerous locations, with two or three replications per location. Information about these hybrids, as compared to several check hybrids, is presented.
The first pedigree listed in the comparison group is the hybrid containing LH185. Information for the pedigree includes:
1. Mean yield of the hybrid across all locations.
2. A mean for the percentage moisture (% M) for the hybrid across all locations.
3. A mean of the yield divided by the percentage moisture (Y/M) for the hybrid across all locations.
4. A mean of the percentage of plants with stalk lodging (% SL) across all locations.
5. A mean of the percentage of plants with root lodging (% RL) across all locations.
6. A mean of the percentage of plants with dropped ears (% DE).
7. The number of locations indicates the locations where these hybrids were tested together.
The series of hybrids listed under the hybrid containing LH185 are considered check hybrids. The check hybrids are compared to hybrids containing the inbred LH 185.
The (+) or (-) sign in front of each number in each of the columns indicates how the mean values across plots of the hybrid containing inbred LH185 compare to the check crosses. A (+) or (-) sign in front of the number indicates that the mean of the hybrid containing inbred LH185 was greater or lesser, respectively, than the mean of the check hybrid. For example, a +4 in yield signifies that the hybrid containing inbred LH185 produced 4 bushels more corn than the check hybrid. If the value of the stalks has a (-) in front of the number 2, for example, then the hybrid containing the inbred LH185 had 2% less stalk lodging than the check hybrid.
TABLE 1______________________________________Overall Comparisons ofLH185 × LH195 Hybrid Vs. Check Hybrid Mean %Hybrid Yield % M Y/M % SL % RL DE______________________________________LH185 × LH195 227 20.95 10.82 1 6 0(at 16 Loc's)as compared to:LH195 × LH212 +7 -.67 +.64 -3 +1 0LH132 × LH212 +16 -.43 +.53 -3 +1 0LH195 × LH59 +14 +.64 +.36 -1 +3 0LH195 × LH184 +14 +.67 +.34 -1 +3 0______________________________________
TABLE 2______________________________________Overall Comparisons ofLH185 × LH198 Hybrid Vs. Check Hybrid Mean %Hybrid Yield % M Y/M % SL % RL DE______________________________________LH185 × LH198 221 20.54 10.78 1 7 0(at 21 Loc's)as compared to:LH132 × LH82 +29 -1.34 +2.02 -1 +1 0LH204 × LH212 +7 -.63 +.65 -2 +2 0LH132 × LH59 +15 -.37 +.92 -1 +2 0LH205 × LH216 +21 -.34 +1.17 0 +1 0LH198 × LH59 +12 -.04 +.59 0 +1 0LH198 × LH82 +27 +.09 +1.29 -1 -4 0______________________________________
TABLE 3______________________________________Overall Comparisons ofLH185 × LH132 Hybrid Vs. Check Hybrid Mean %Hybrid Yield % M Y/M % SL % RL DE______________________________________LH185 × LH132 211 21.42 9.85 1 6 0(at 17 Loc's)as compared toLH132 × LH212 +3 -.86 +.51 -1 +3 0LHE136 × LH82 +22 -.03 +1.05 -1 +3 0LH132 × LH59 +17 +.44 +.61 -1 +1 0LH204 × LH212 +2 +.91 -.37 -2 +1 0______________________________________
TABLE 4______________________________________Overall Comparisons ofLH185 × LH74 Hybrid Vs. Check Hybrid Mean %Hybrid Yield % M Y/M % SL % RL DE______________________________________LH185 × LH74 189 20.91 9.03 3 4 0(at 21 Loc's)as compared toLH74 × LH51 +1 -2.31 +.95 -1 -1 0LH216 × LH206 +1 -1.84 +.76 +2 0 0LH132 × LH165 +11 -1.09 +.96 0 -1 0LH132 × LH167 +1 -.34 +.18 -1 -1 0LH202 × LH82 +14 -.08 +.64 -4 -2 0______________________________________
DEPOSIT INFORMATION
Inbred seeds of LH185 have been placed on deposit with the American Type Culture Collection (ATCC), Rockville, Md. 20852, under Deposit Accession Number 75618 on Dec. 3, 1993. A Plant Variety Protection Certificate is being applied for with the United States Department of Agriculture.
Although the foregoing invention has been described in some detail by way of illustration and example for purposes of clarity and understanding, it will be obvious that certain changes and modifications may be practiced within the scope of the invention, as limited only by the scope of the appended claims. | 4y
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BACKGROUND OF THE INVENTION
This invention relates generally to continuous web business processing machines and particularly to a conveyor apparatus forming an integral part of such a machine which provides that document blanks are sequentially deposited on the continuous web in an overlapped relation.
Continuous web business processing machines of the type under consideration commonly produce a combination product which consists of the web having document blanks attached thereto. The blanks frequently require further processing in the nature of printing for example and it is a considerable advantage to provide that such blanks are overlapped with respect to each other so that they can be fed as a continuous stream into a printing machine in such a way that each blank tends to hold the following blank in place and thereby avoid disengagement, tearing and other problems to which the blanks would otherwise be subject as they are passed between rollers and other mechanisms. In addition the overlap condition tends to render the web, blank combination easier to package and store.
Conveyor apparatus which provides this overlap alignment are known and one such apparatus is disclosed in U.S. Pat. No. 4,270,967. In this apparatus an angled overhead conveyor rack assembly is used in combination with a bottom conveyor assembly, the combination being disposed between a feeder such as a Halm Jet rotary vacuum feeder and a compression station. The bottom conveyor is provided with longitudinally spaced stops at intervals shorter than the length of the blanks. The leading edge of the document blank is intercepted by one of the stops and the trailing end is raised by a succeeding stop in cooperation with the overhead conveyor rack which applies a downward force onto the document blank as the document blank moves toward the compression station. The operation of this overlap device and particularly the aligned forward movement of the blank depends upon the use of the overhead rack which is a somewhat complicated and therefore expensive device.
Another apparatus which provides for the staggering of blanks of sheet material is disclosed in U.S. Pat. No. 3,672,667. This patent discloses the use of an endless conveyor having a wedge cam element on the outer surface. The cam is provided with an inclined leading flank and a trailing flank. Blanks fed onto the conveyor impinge against the trailing flank and the blanks are held onto the conveyor by suction during travel. The leading edge of the cam raises preceding blanks to permit following blanks to be received under said preceding blanks by virtue of the reduced exit speed of the blanks. A carrier sheet business form assembly having overlapping blanks is shown in U.S. Pat. No. 4,091,987 and is standard in the industry.
SUMMARY OF THE INVENTION
This conveyor apparatus is used in connection with a continuous web business processing machine to provide accurate, overlapping alignment of blanks deposited on the continuous web at high speed.
The conveyor apparatus includes a first endless, flexible conveyor having at least one endless flexible element and having upper and lower spans, said element providing a plurality of pins having a leading flank and an inclined trailing flank, a second conveyor carrying the elongated web; blank feed means at the upstream end of the first conveyor for depositing blanks onto said upper span of said conveyor with the leading end of the blank extending beyond the leading flank of the pin and being disposed in overlapping relation above the trailing end of the preceeding blank, and blank takeoff means at the downstream end of the first conveyor for removing blanks from the upper stand of said conveyor and depositing said blanks onto the web carried by the second conveyor with the leading end of the blank being disposed in underlapping relation below the tailing end of the preceeding blank and in contact with a gum line of the web.
In one aspect of the invention the first conveyor includes a pair of flexible elements disposed in side-by-side relation, the pins on one element being transversely aligned with the pins on the other element.
It is an aspect of this invention to provide blank feed means depositing blanks onto the upper span of the first conveyor at a surface speed at least as great as the surface speed of the upper span to facilitate engagement of the trailing edge of the blank against the leading flank of the following pin.
It is another aspect of this invention to provide blank takeoff means removing blanks from the upper stand of the first conveyor at a surface speed at least as great as the surface speed of the upper stand to avoid continuous engagement between the trailing edge of a blank and the leading flank of the following pin.
It is yet another aspect of this invention to provide that the first conveyor includes brush means for retarding the speed of the blanks deposited on said conveyor upper span to facilitate engagement between the trailing edge of a blank and the leading flank of the following pin.
Still another aspect of this invention is to provide that the endless flexible elements of the first conveyor are chains, having lugs attached thereto at intervals along the length thereof for mounting the pins.
It is another aspect of this invention to provide pins which are recessed on the trailing flank and include an elongate slotted opening to the mid-lengthwise adjustment of the pins relative to the direction of movement of the chain.
Still another aspect of this invention is to provide pins which are substantially wedge-shaped having a leading flank substantially perpendicularlly disposed to the direction of travel of the flexible elements of the upper conveyor.
Yet another aspect of this invention is to provide pins which are selectively removable to vary the spacing between said pins to suit selected blank sizes.
Yet another aspect of this invention is to provide a method of overlapping blanks deposited from a feed device onto an endless conveyor comprising the steps of delivering blanks onto the conveyor upper span at equal time intervals; raising the leading end of the blank relative to the trailing end at the point spaced rearwardly from the leading edge thereof above the trailing end of a preceeding blank; engaging the relatively low trailing end of the blank and pushing the blank at the speed of the conveyor and maintaining the blank in an overlap condition during travel of the blank for substantially the length of the conveyor.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a generally schematic side elevational view of the conveyor apparatus;
FIG. 2 is a plan view on line 2--2 of FIG. 1;
FIG. 3 is an enlarged cross sectional view taken on line 3--3 of FIG. 1;
FIG. 4 is a fragmentary sectional view taken on line 4--4 of FIG. 3,
FIG. 5 is a schematic illustrating an end product of the conveyor apparatus, and
FIG. 6 is an enlarged perspective view of a wedge-shaped pin.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now by reference numerals to the drawings and first to FIGS. 1 and 2 it will be understood that the conveyor apparatus generally indicated by numeral 10 forms an integral part of a business form machine of the type used for processing an elongate web W and depositing document blanks B such as envelopes at intervals along said web.
The conveyor apparatus 10 consists essentially of an upper conveyor 12 and a lower conveyor 14, constituting first and second conveyors respectively, both mounted to a side support structure generally indicated by numeral 15 and similar to the support structure shown in U.S. Pat. No. 4,249,984 and U.S. Pat. No. 4,257,514. A feed means for projecting a continuous stream of blanks B onto the upper conveyor and generally indicated by 16, is disposed at the upstream end of the upper conveyor 12, a blank take-off means generally indicated by 18 is disposed at the downstream end of the upper conveyor 12 for removing blanks from the upper conveyor and depositing said blanks onto the perforated carrier web W carried by the lower conveyor 14. The web includes transverse fold lines 20, as shown in FIG. 5 and transverse gum lines 22 are disposed intermediate alternate pairs of fold lines 20 on the upper side of said web, said gum lines being applied at equal intervals along the length of the web W at a gumming station (not shown) disposed upstream of the lower conveyor 14. The web and blank combination is collected at a fan folding station 24 disposed at the downstream end of the lower conveyor 14 and collected at a collecting station 26. Alternatively, the web and blank combination can be collected in rolls.
Referring now more specifically to the component parts of the upper conveyor 12 and with particular reference to FIGS. 1, 2, 3, and 4 it will be understood that said conveyor includes at least one and preferably a pair of transversely spaced chains 30, constituting endless flexible elements and providing upper and lower spans 32 and 34 which travel around upstream and downstream rotatable sprocket elements 36 and 38. Sprocket elements 36 are mounted on an idler shaft 35 and sprocket elements 38 are mounted on a drive shaft 37, said shafts 35 and 37 being carried by the support frame 15. Shaft 37 is connected to a drive means generally indicated by 120 and a chain drive 122 interconnects shafts 35 and 37 as shown in FIG. 2. Importantly, chains 30 carry a plurality of generally wedge-shaped pins 40 disposed at equally spaced intervals along the length of the chains and attached to said chains as by L-shaped lugs 42. As shown in FIG. 6, the pins 40 include, relative to the direction of motion of the upper span, a perpendicular leading flank 44 and an inclined trailing flank 46. In the embodiment shown in FIG. 6, each pin 40 includes a recess 48 and an elongate bottom opening 50 and said pin 40 is attached to said lug 42 as by a removable fastener 52. In the embodiment shown the blanks are envelopes but the apparatus can readily be modified to suit longer blanks such as letterheads by simply removing selected pins 42.
As shown in FIG. 3 the chains 30 are disposed between intermediate and side portions 56 and 58 respectively of a table assembly 54, the side portions 58 being slotted to receive the pins 40. The upper surface of said table 54 is disposed slightly above the lowest portion of the pin inclined flank 46 so that, as shown in FIG. 4, the inclined flank presents no obstacle to movement of a blank B received by said table surface. The upper conveyor 12 also includes a super adjacent brush assembly 60 providing opposed support arms 62 each carrying a plurality of brush elements 64 depending therefrom in angled relation.
The feed device 16 at the upstream end of the upper conveyor 12 includes a supply tray 70 carrying a stack of blanks B and having a forward lip 72 and a feed wheel 74 mounted to a shaft 73 carried by the support frame 15 and being engageable with the blanks B to transfer said blanks from said tray 70 onto the table assembly 54. In the embodiment shown, the feed wheel 74 is connected to the shaft 35 through a drive means generally indicated by numeral 124. The circumferential surface speed of the feed wheel 74 relative to the linear speed of the conveyor upper span 32 and the longitudinal spacing of the pins 40 relative to the length of the blank B are such that the leading edge 82 of the blank B slides up the inclined flank 46 while the trailing edge 84 of said blank engages the upright flank 44 of the following pin. In the embodiment shown, the brushes 64 provide the necessary retarding effect to facilitate this action. The disposition of the pins 40 as described provides that the blanks B are deposited on the conveyor upper span 32 with the leading end of the blank extending beyond the leading flank of the pins 40 and being disposed in overlaping relation above the trailing end of the preceding blank.
As shown in FIG. 1 the blanks B are carried by the conveyor upper span 30 in a generally horizontal condition into the vicinity of the take-off means 18. The leading edge 80 of the blank B is engaged and carried forwardly by a disc assembly 84 consisting of spaced pairs of discs 86 and 88 mounted to shafts 85 and 87 respectively, carried by the support frame 15. Disc assembly 84 is disposed upstream of a vacuum drum 90. The drum 90 is mounted to a shaft 89 carried by the support frame 15 and forms part of the take-off means, and continues the movement of the blanks through a reverse turn guided by a curved guide assembly 92 to deposit blanks B onto the web W carried by the lower conveyor 14. As best shown in FIGS. 1, 3 and 4 the lower conveyor 14 is of the pin chain type consisting of upstream and downstream pin chain units 100 and 102 disposed adjacent a table plate 110 carrying the web W. Pin chain units 100 and 102 include drive and idler sprockets 104 and 106 mounted to shafts 103 and 105 respectively carried by the side frame 15 and pin chains 108, which engage the perforations of the web W to transport the web W along the plate 110.
The disc assembly shafts 87 and 89 and the shaft 91 vacuum drum are operatively connected to the drive shaft 37 by drive means indicated by 125 and 126 respectively. The drive shaft 103 of the pin chain units 100 is operatively connected to shaft 37 by drive means indicated by 128 and the drive shafts 103 of the two pin chain units 100 and 102 are operatively connected together by a chain assembly (not shown). The vacuum drum 90 deposits the blanks B onto the web W in an upside down condition such that the face of the blanks which was uppermost during travel along the upper span 32 of the upper conveyor 12 becomes the lowermost face. Consequently, the blank B is deposited on the web W carried by the lower conveyor 16 with the leading end disposed in underlapping relation below the trailing end of the preceding blank and in contact with one of the gum lines 22 provided at spaced intervals along the length of the web W as clearly shown in FIG. 4. The circumferential surface speeds of the discs 86 and 88 and the vacuum drum 90, relative to the linear speed of the lower conveyor are such that the overlap of the blanks B is maintained. This is shown in FIG. 4 in which overlap "A" on the upper conveyor 12 is substantially equal to overlap "a" in the lower conveyor 14.
In the preferred embodiment the linear speed of the web W as determined by the lower conveyor 14 can be considered as a reference speed. The linear speed of the upper conveyor 12 which carries the blanks is substantially equal to the speed of the web W. However, the circumferential surface speed of the feed wheel 74 is preferably in excess of the speed of the upper conveyor 12 to facilitate accurate placement of the blanks B on said upper conveyor. The circumferential surface speed of the take-off discs 86 and 88 is also greater than the speed of the upper conveyor so that the pins 40 do not catch the trailing edge of the blanks B as the pins turn around sprocket 38. The circumferential surface speed of the vacuum drum 90 is substantially the same as the linear speed of the web W so that there is a minimum of differential movement when the blanks are disposed on the web.
The fan-folding take-off means 24 disposed adjacent the downstream end of the lower conveyor 14 includes a receiving table plate 112 and guide plate 114 which direct the combined web W and blanks B into the vicinity of a vacuum wheel assembly 116 mounted to a shaft 115 carried by the support frame 15. The wheel assembly fan-folds the combined web and blank and deposits the fan-folded combination by way of a guide plate 118 to the collection station 26. Although fan-folding is convenient for packaging the combination web and blanks can be stored in a roll if desired.
In the embodiment shown, the contour of the inclination of the trailing flank 46 of the pins 40 is straight. However, the contour of the trailing flank can be varied so long as the height of the pin 40 which projects above the lapped blank is at least as great as the thickness of the blank material.
When it is desired to vary the spacing of the pins 40 to suit a different blank it is simply a matter of removing selected pins to increase the spacing to two or three times the spacing between the pins. The extent of the overlap is not critical so long as it is sufficient to prevent unlapping and therefore fine adjustment of pin spacing is not essential. However, the pins are lengthwise adjustable to compensate for chain stretching. | 4y
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This application is a Divisional of application Ser. No. 10/799,907, filed Mar. 12, 2004, U.S. Pat. No. 6,977,319.
FIELD OF THE INVENTION
The present invention is directed to novel alkylated aromatic compositions, zeolite catalyst compositions and processes for making the same. The catalyst compositions comprise zeolite Y and mordenite zeolite having a controlled macropore structure. The present invention is also directed to the preparation of the catalyst compositions and their use in the preparation of novel alkylated aromatic compositions. The catalyst compositions of the present invention exhibit reduced deactivation rates during the alkylation process, thereby increasing the life of the catalysts.
BACKGROUND OF THE INVENTION
It is well known to catalyze the alkylation of aromatics with a variety of Lewis or Bronsted acid catalysts. Typical commercial catalysts include phosphoric acid/kieselguhr, aluminum halides, boron trifluoride, antimony chloride, stannic chloride, zinc chloride, onium poly(hydrogen fluoride), and hydrogen fluoride. Alkylation with lower molecular weight olefins, such as propylene, can be carried out in the liquid or vapor phase. For alkylations with higher olefins, such as C 16 olefins, the alkylations are done in the liquid phase, usually in the presence of hydrogen fluoride. Alkylation of benzene with higher olefins is especially difficult, and requires hydrogen fluoride treatment. However, hydrogen fluoride is not environmentally attractive.
The use of the above listed acids is extremely corrosive, thus requiring special handling and equipment. Also, the use of these acids might involve environmental problems. Another problem is that the use of these acids can give less than desirable control on the precise chemical composition of the product produced. Thus, it is preferable to use a safer, simpler catalyst, preferably in solid state. This simpler process would result in less capital investment, which would result in a less expensive product.
Solid crystalline aluminosilicate zeolite catalysts have been known to be effective for the alkylation of aromatics with olefins. Zeolitic materials which are useful as catalysts are usually inorganic crystalline materials that possess uniform pores with diameters in micropore range that is less than 20 angstroms. Zeolites occur naturally and may also be prepared synthetically. Synthetic zeolites include, for example, zeolites A, X, Y, L and omega. It is also possible to generate metaloaluminophosphates and metalosilicophosphates. Other materials, such as boron, gallium, iron or germanium, may also be used to replace the aluminum or silicon in the framework structure.
These zeolite catalyst materials are commercially available as fine crystalline powders for further modification to enhance their catalytic properties for particular applications. Processes for the further modification to enhance catalytic properties of the zeolite catalysts are well known in the art, such as forming the zeolite catalysts into shaped particles, exchanging the cations in the catalyst matrix, etc.
Forming zeolite powders into shaped particles may be accomplished by forming a gel or paste of the catalyst powder with the addition of a suitable binder material such as a clay, an inorganic compound, or an organic compound and then extruding the gel or paste into the desired form. Zeolite powders may also be formed into particles without the use of a binder. Typical catalyst particles include extrudates whose cross sections are circular or embrace a plurality of arcuate lobes extending outwardly from the central portion of the catalyst particles.
One problem with catalyst particles used in fixed bed reactors is catalyst deactivation. In most hydrocarbon conversion processes, including alkylation, the primary catalyst deactivation is caused by coke formation. This catalyst deactivation is a serious problem in the use of zeolite catalysts for alkylation reactions. This deactivation problem is well known in the art and it is well understood that the deactivation mechanism can involve polymerization of the olefin into large molecular species that cannot diffuse out of the pores containing the active sites in the zeolitic material.
The use of zeolite catalysts for preparation of alkyl aromatics is typically conducted by the catalytic alkylation of aromatic hydrocarbons with normal alpha olefins or branched-chain olefins, and optionally a promotor. The alkylated aromatic hydrocarbons can be converted into corresponding sulfonic acids which can be further converted into alkylated aromatic sulfonates.
A number of patents have discussed processes for the preparation of zeolite catalysts and the further shaping and forming of the catalyst particles and extrudates with and without the use of binders. There are also a number of patents disclosing the use of zeolite catalysts for alkylation of aromatic hydrocarbons.
U.S. Pat. No. 3,094,383 discloses the preparation of synthetic zeolite materials which upon hydration yield a sorbent of controlled effective pore diameter and in which the sorbent and its zeolite precursor are provided directly in the form of an aggregate.
U.S. Pat. No. 3,130,007 discloses the method of preparing sodium zeolite Y with silica to alumina ratios ranging from greater than 3 to about 3.9.
U.S. Pat. No. 3,119,660 discloses a process for making massive bodies or shapes of crystalline zeolites. The patent also discloses methods for the identification of the catalyst materials using X-ray powder diffraction patterns in conjunction with chemical analyses.
U.S. Pat. No. 3,288,716 discloses that the high “heavy content” of the alkylated aromatic product can be controlled during the alkylation step and has advantages over distilling the alkylated aromatic product to obtain the desired molecular weight.
U.S. Pat. Nos. 3,641,177 and 3,929,672 disclose the technique to remove sodium or other alkali metal ions from zeolite catalysts. The '177 patent also discloses that such removal of the sodium or other alkali metal ions activates the zeolite catalysts for the alkylation of aromatic hydrocarbons with olefins by liquid phase reaction.
U.S. Pat. Nos. 3,764,533, 4,259,193 and 5,112,506 disclose the “heavy alkylate” content influences neutral sulfonates and overbased sulfonates. In U.S. Pat. No. 5,112,506, the effect of molecular weight distribution or “heavy alkylate” is shown to influence the performance of both Neutral and HOB sulfonates and the di-alkylate content is shown to influence the rust performance of the corresponding sulfonate in U.S. Pat. No. 3,764,533. In U.S. Pat. No. 4,259,193, a mono-alkylate sulfonate is preferred. U.S. Pat. Nos. 3,288,716; 3,764,533; 4,259,193; and 5,112,506 are hereby incorporated by reference for all purposes.
U.S. Pat. No. 3,777,006 discloses the use of nucleating centers for the crystallization of crystalline aluminosilicate zeolites having a size in excess of 200 microns and characterized by high strength and excellent adsorptive properties.
U.S. Pat. No. 4,185,040 discloses the preparation of highly stable and active catalysts for the alkylation of aromatic hydrocarbons with C 2 –C 4 olefins. The catalysts are acidic crystalline aluminosilicate zeolites which exhibit much improved deactivation rates.
U.S. Pat. No. 4,395,372 discloses an alkylation process for alkylating benzene comprising contacting benzene and lower olefins with a rare earth exchanged X or Y zeolite catalyst in the presence of sulfur dioxide.
U.S. Pat. No. 4,570,027 discloses the use of a low crystallinity, partially collapsed zeolite catalyst for producing alkylaromatic hydrocarbons. The alkylation reaction also involves conditioning the catalyst bed with hydrogen prior to conducting the alkylation reaction.
U.S. Pat. Nos. 4,762,813; 4,767,734; 4,879,019 and 5,111,792 disclose the preparation of a hydrocarbon conversion catalyst using a low silica to alumina ratio zeolite Y bound into an extrudate and steamed to modify the catalyst.
U.S. Pat. No. 4,764,295 discloses a process for making non-foaming detergent-dispersant lubricating oil additives. The process further involves carbonation for making the products more basic.
U.S. Pat. No. 4,876,408 discloses an alkylation process using an ammonium-exchanged and steam stabilized zeolite Y catalyst having an increased selectivity for mono-alkylation. The process involves the presence of at least one organic compound under conditions such that sufficient amount of carbonaceous material evenly deposits on the alkylation catalyst to substantially suppress its alkylation activity.
U.S. Pat. No. 4,891,448 discloses a process for alkylation of polycyclic aromatic compounds in the presence of an acidic mordenite zeolite catalyst having a silica to alumina molar ratio of at least 15:1 to produce a mixture of substituted polycyclic aromatic compounds enriched in the para alkylated isomers.
U.S. Pat. No. 4,916,096 discloses use of a zeolite Y catalyst for hydroprocessing. The zeolite Y catalyst comprises a modified crystalline aluminosilicate zeolite Y, a binder and at least one hydrogenation component of a Group VI or a Group VIII metal.
U.S. Pat. No. 5,004,841 discloses a process for alkylation of polycyclic aromatic compounds in the presence of an acidic mordenite zeolite catalyst having a silica to alumina molar ratio of at least 15:1 to produce substituted polycyclic aromatic compounds enriched in the linear alkylated isomers.
U.S. Pat. No. 5,026,941 discloses the use of a zeolite Y catalyst having a silica to alumina ratio of 15 to 110 for the alkylation of naphthalene or mono-isopropylnaphthalene.
U.S. Pat. No. 5,118,896 discloses an aromatic alkylation process comprising the steps of contacting a hydrocarbon feed with an alkylating agent under liquid phase alkylation conditions in the presence of a silica-containing large macropore, small particle size zeolite catalyst, the catalyst having a pore volume of about 0.25 to 0.50 cc/g in pores having a radius of 450 angstroms and a catalyst particle diameter of not more than 1/32 of an inch.
U.S. Pat. No. 5,175,135 discloses the use of an acidic mordenite zeolite catalyst for alkylation of aromatic compounds with an alkylating agent having from one carbon atom to eight carbon atoms to produce substituted aromatic compounds enriched in the linear alkylated isomers. The acidic mordenite catalyst is characterized by its silica to alumina molar ratio, its porosity and a Symmetry Index.
U.S. Pat. No. 5,191,135 discloses the process for making long-chain alkyl-substituted aromatic compounds from naphthalenes, the process comprising a zeolite alkylation catalyst in the presence of 0.5 to 3.0 weight percent water. The presence of water increases the selectivity for making mono-alkylated products.
U.S. Pat. Nos. 5,240,889 and 5,324,877 disclose processes for the preparation of a catalyst composition having alkylation and/or transalkylation activity and wherein the catalyst composition contains greater than 3.5 weight percent water based on the total weight of the catalyst composition and the aromatic alkylation process using said catalyst composition and olefins containing 2 carbon atoms to 25 carbon atoms.
U.S. Pat. No. 5,198,595 discloses a process for alkylation of benzene or substituted benzene in the presence of an acidic mordenite zeolite catalyst having a silica to alumina ratio of at least 160:1 and a Symmetry Index above about 1.0. A process for the preparation of the catalyst is also disclosed.
U.S. Pat. No. 5,243,116 discloses the production of alkylated benzenes by alkylation and/or transalkylation in the presence of an acidic mordenite zeolite catalyst having a silica to alumina molar ration of at least 30:1 and a specific crystalline structure determined by X-ray diffraction.
U.S. Pat. No. 5,453,553 discloses a process for the production of linear alkyl benzenes which process comprises co-feeding a mixture of benzene, linear olefins and molecular hydrogen in the presence of a zeolite catalyst containing a transition metal under alkylation condition such that the catalyst is not deactivated.
U.S. Pat. No. 5,506,182 discloses the preparation of a catalyst composition comprising 10 to 90 percent of a modified zeolite Y catalyst formed from a modified zeolite Y and 10 to 90 percent binder using slurries of the modified zeolite Y and the binder to form the catalyst composition having a clear absorption peak in an IR spectrum of a wavelength of 3602 per centimeter. The patent also discloses the substitution of iron for the alumina in the zeolite Y structure.
U.S. Pat. No. 5,922,922 discloses a process for isomerizing a normal alpha olefin in the presence of an acidic catalyst having a one-dimensional pore system, and then using the isomerized olefin to alkylate aromatic hydrocarbons in the presence of a second acidic catalyst, which can be zeolite Y having a silica to alumina ratio of at least 40 to 1.
U.S. Pat. No. 5,939,594 discloses the preparation of a superalkalinized alkylaryl sulfonate of alkaline earth metal. The alkyl group of the alkylaryl sulfonate contains between 14 to 40 carbon atoms and the aryl sulfonate radical of alkaline earth metal is fixed in a molar proportion comprised between 0 and 13% in positions 1 or 2 of the linear alkyl chain.
U.S. Pat. No. 6,031,144 discloses a process for reducing the residual olefin content of an alkylation reaction product by removing at least a portion of the non-alkylated single-ring aromatic hydrocarbon and then reacting the remaining alkylation reaction product in the presence of an acidic catalyst such as a molecular sieve or clay.
U.S. Pat. No. 6,337,310 discloses the preparation of alkylbenzene from preisomerized normal alpha olefins for making low overbased and high overbased sulfonates having a TBN in the range of 3 to 500. The process uses HF as catalyst or a solid acidic alkylation catalyst, such as a zeolite having an average pore size of at least 6 angstroms.
U.S. Pat. No. 6,525,234 discloses a process for alkylating aromatic using a porous crystalline material, e.g., MCM-22 and in situ regenerating the catalyst by use of a polar compound having a dipole moment of at least 0.05 Debyes.
It is known that most solid acid catalysts produce high 2-aryl attachment when alkylating with alpha-olefins. See S. Sivasanker, A. Thangaraj, “Distribution of Isomers in the Alkylation of Benzene with Long-Chain Olefins over Solid Acid Catalysts,” Journal of Catalysis, 138, 386–390 (1992). This is especially true for mordenite zeolite.
Two general treatises on zeolite are: Handbook of Molecular Sieves by Rosemarie Szostak (Van Nostrand Reinhold, New York 1992) and Molecular Sieves: Principles of Synthesis and Identification, 2 nd Edition, by Rosemarie Szostak (Chapman and Hall, London, UK 1999).
SUMMARY OF THE INVENTION
The present invention is directed to novel alkylated aromatic compositions and processes for preparation of carbonated, overbased alkylated aromatic sulfonates, which processes comprise the alkylation in the presence of the catalyst composites of this invention, and further sulfonation and carbonation, overbasing of the alkylated aromatic sulfonic acids.
The present invention is also directed to zeolite catalyst compositions having a controlled macropore structure comprising zeolite Y and mordenite zeolite. The present invention is also directed to a process for preparing the catalyst compositions. The catalysts and catalyst compositions exhibits reduced deactivation rates during the alkylation process, thereby increasing the life of the catalysts and the catalyst compositions.
In particular, the present invention is directed to an alkylated aromatic composition comprising a mixture of:
(a) an alkylated aromatic hydrocarbon alkylation product wherein the alkylation reaction is conducted in the presence of an alkylation catalyst having a macropore structure comprising zeolite Y, and wherein the peak macropore diameter of the catalyst, measured by ASTM Test No. D 4284-03, is less than or equal to about 2000 angstroms and the cumulative pore volume of the catalyst at pore diameters less than or equal to about 500 angstroms, measured by ASTM Test No. D 4284-03, is less than or equal to about 0.30 milliliters per gram; and (b) an alkylated aromatic hydrocarbon alkylation product wherein the alkylation reaction is conducted in the presence of an alkylation catalyst having a macropore structure comprising mordenite zeolite having a silica to alumina molar ratio of about 50 to about 105 and wherein the peak macropore diameter of the catalyst, measured by ASTM Test No. D 4284-03, is less than or equal to about 900 angstroms and the cumulative pore volume of the catalyst at pore diameters less than or equal to about 500 angstroms, measured by ASTM Test No. D 4284-03, is less than or equal to about 0.30 milliliters per gram.
The weight percent of the alkylated aromatic hydrocarbon of (a) in the mixture may be in the range of about 40 percent to about 99 percent based on the total alkylated aromatic composition. Preferably the weight percent of the alkylated aromatic hydrocarbon of (a) in the mixture is in the range of about 50 percent to about 90 percent based on the total alkylated aromatic composition, and more preferably the weight percent of the alkylated aromatic hydrocarbon of (a) in the mixture is in the range of about 70 percent to about 80 percent based on the total alkylated aromatic composition.
The alkyl groups of the alkylated aromatic composition may be derived from alpha olefins, isomerized olefins, branched-chain olefins, or mixtures thereof. The alpha olefins or the isomerized olefins have from about 6 carbon atoms to about 40 carbon atoms. Preferably, the alpha olefins or the isomerized olefins have from about 20 carbon atoms to about 40 carbon atoms. The branched-chain olefins have from about 6 carbon atoms to about 70 carbon atoms. Preferably, the branched-chain olefins have from about 8 carbon atoms to about 50 carbon atoms. More preferably, the branched-chain olefins have from about 12 carbon atoms to about 18 carbon atoms.
The alkyl groups of the alkylated aromatic composition may be partially-branched-chain isomerized olefins wherein the olefins have from about 6 carbon atoms to about 40 carbon atoms. Preferably, the partially-branched-chain isomerized olefins have from about 20 carbon atoms to about 40 carbon atoms.
The aromatic hydrocarbon of the alkylated aromatic composition may be benzene, toluene, xylene, cumene, or mixtures thereof. Preferably, the aromatic hydrocarbon is toluene or benzene.
The zeolite Y in step (a) and the mordenite zeolite in step (b) may contain a binder. Preferably, the binder in the zeolite Y in step (a) and the binder in the mordenite zeolite in step (b) is alumina.
The zeolite Y in step (a) and the mordenite zeolite in step (b) may be in the form of a tablet.
Another embodiment of the present invention is directed to a process for preparing an alkylated aromatic composition comprising:
(a) contacting at least one aromatic hydrocarbon with at least one olefin under alkylation conditions in the presence of a zeolite catalyst having a macropore structure comprising zeolite Y, and wherein the peak macropore diameter of the catalyst, measured by ASTM Test No. D 4284-03, is less than or equal to about 2000 angstroms and the cumulative pore volume of the catalyst at pore diameters less than or equal to about 500 angstroms, measured by ASTM Test No. D 4284-03, is less than or equal to about 0.30 milliliters per gram to form a first alkylated aromatic hydrocarbon product; (b) contacting at least one aromatic hydrocarbon with at least one olefin under alkylation conditions in the presence of a zeolite catalyst having a macropore structure comprising mordenite zeolite having a silica to alumina molar ratio of about 50 to about 105, and wherein the peak macropore diameter of the catalyst, measured by ASTM Test No. D 4284-03, is less than or equal to about 900 angstroms and the cumulative pore volume of the catalyst at pore diameters less than or equal to about 500 angstroms, measured by ASTM Test No. D 4284-03, is less than or equal to about 0.30 milliliters per gram to form a second alkylated aromatic hydrocarbon product; and (c) combining the first alkylated aromatic hydrocarbon product and the second alkylated aromatic hydrocarbon product to form the alkylated aromatic composition;
wherein steps (a) and (b) can be conducted in any order.
The above process may further comprise in step (b) the reactivation of the deactivated zeolite catalyst with a suitable solvent flush, preferably the solvent is an aromatic hydrocarbon. More preferably, the aromatic hydrocarbon is benzene.
The above process may further comprise sulfonating the alkylated aromatic composition to form an alkylated aromatic sulfonic acid. The alkylated aromatic sulfonic acid may be reacted with an alkaline earth metal and carbon dioxide to produce a carbonated, overbased alkylated aromatic sulfonate.
The first alkylated aromatic hydrocarbon product in the alkylated aromatic composition may be in the range of about 40 percent to about 99 percent based on the total alkylated aromatic composition. Preferably, the first alkylated aromatic hydrocarbon product in the alkylated aromatic composition is in the range of about 50 percent to about 90 percent based on the total alkylated aromatic composition. More preferably, the first alkylated aromatic hydrocarbon product in the alkylated aromatic composition is in the range of about 70 percent to about 80 percent based on the total alkylated aromatic composition.
The olefin in step (a) and step (b) may be independently an alpha olefin, an isomerized olefin, a branched-chain olefin, or mixtures thereof. The alpha olefin or isomerized olefin may have from about 6 carbon atoms to about 40 carbon atoms. Preferably, the alpha olefin or isomerized olefin has from about 20 carbon atoms to about 40 carbon atoms. The branched-chain olefin may have from about 6 carbon atoms to about 70 carbon atoms. Preferably, the branched-chain olefin has from about 8 carbon atoms to about 50 carbon atoms. More preferably, the branched-chain olefin has from about 12 carbon atoms to about 18 carbon atoms.
The olefin in step (a) or step (b) may be independently a partially-branched-chain isomerized olefin, and the olefin may have from about 6 carbon atoms to about 40 carbon atoms. Preferably, the partially-branched-chain isomerized olefin has from about 20 carbon atoms to about 40 carbon atoms.
The aromatic hydrocarbon of the alkylated aromatic composition may be benzene, toluene, xylene, cumene, or mixtures thereof. Preferably, the aromatic hydrocarbon is toluene or benzene.
The cumulative pore volume of the zeolite catalyst at pore diameters less than or equal to about 400 angstroms in step (a) and step (b) is less than or equal to about 0.30 milliliters per gram. Preferably, cumulative pore volume of the zeolite catalysts at pore diameters less than or equal to about 300 angstroms in steps (a) and (b) is less than about 0.25 milliliters per gram, more preferably at pore diameters less than or equal to about 300 angstroms is less than about 0.20 milliliters per gram, and most preferably at pore diameters less than or equal to about 300 angstroms is in the range of about 0.08 milliliters per gram to about 0.16 milliliters per gram.
The cumulative pore volume of the zeolite catalysts at pore diameters less than or equal to about 400 angstroms in steps (a) and (b) is in the range of about 0.05 milliliters per gram to about 0.18 milliliters per gram. Preferably, the cumulative pore volume of the zeolite catalysts at pore diameters less than or equal to about 300 angstroms in steps (a) and (b) is in the range of about 0.08 milliliters per gram to about 0.16 milliliters per gram.
The zeolite Y catalyst in step (a) has a peak macropore diameter in the range of about 700 angstroms to about 1800 angstroms. Preferably, the peak macropore diameter of the zeolite Y catalyst in step (a) is in the range of about 750 angstroms to about 1600 angstroms. More preferably, the peak macropore diameter of the zeolite Y catalyst in step (a) is in the range of about 900 angstroms to about 1400 angstroms.
In step (b), the peak macropore diameter of the mordenite zeolite catalyst is in the range of about 400 angstroms to about 800 angstroms. Preferably in step (b), the peak macropore diameter of the mordenite zeolite catalyst is in the range of about 400 angstroms to about 700 angstroms. More preferably in step (b), the peak macropore diameter of the mordenite zeolite catalyst is in the range of about 450 angstroms to about 600 angstroms.
In steps (a) in the above process, the zeolite Y catalyst has a silica to alumina ratio of about 5:1 to about 100:1. Preferably in step (a), the zeolite Y catalyst has a silica to alumina ratio of about 30:1 to about 90:1. More preferably in step (a), the zeolite Y catalyst has a silica to alumina ratio of about 60:1 to about 80:1.
In step (b) in the above process, preferably the mordenite zeolite catalyst has a silica to alumina ratio of about 60:1 to about 80:1.
The zeolite Y in step (a) and the mordenite zeolite in step (b) may contain a binder. Preferably, the binder in the zeolite Y in step (a) and the binder in the mordenite zeolite in step (b) is alumina.
The zeolite Y in step (a) and the mordenite zeolite in step (b) may be in the form of a tablet.
A further embodiment of the present invention is directed to a process for preparing an alkylated aromatic composition comprising contacting at least one aromatic hydrocarbon with at least one olefin in the presence of a zeolite catalyst having a macropore structure comprising zeolite Y and mordenite zeolite having a silica to alumina ratio of about 50:1 to about 105:1, and wherein the peak macropore diameter of the catalyst, measured by ASTM Test No. D 4284-03, is less than or equal to about 2000 angstroms and the cumulative pore volume of the catalyst at pore diameters less than or equal to about 500 angstroms, measured by ASTM Test No. D 4284-03, is less than or equal to about 0.30 milliliters per gram.
The cumulative pore volume of the zeolite catalyst at pore diameters less than or equal to about 400 angstroms is less than or equal to about 0.30 milliliters per gram. Preferably, the cumulative pore volume zeolite catalyst at pore diameters less than or equal to about 300 angstroms is less than or equal to about 0.25 milliliters per gram. More preferably, the cumulative pore volume zeolite catalyst at pore diameters less than or equal to about 300 angstroms is less than or equal to about 0.20 milliliters per gram.
The cumulative pore volume of the zeolite catalyst at pore diameters less than or equal to about 400 angstroms may be in the range of about 0.05 milliliters per gram to about 0.18 milliliters per gram. Preferably, the cumulative pore volume of the zeolite catalyst at pore diameters less than or equal to about 300 angstroms is in the range of about 0.08 milliliters per gram to about 0.16 milliliters per gram.
The peak macropore diameter of the zeolite catalyst is in the range of about 400 angstroms to about 1500 angstroms. Preferably, the peak macropore diameter of the zeolite catalyst is in the range of about 500 angstroms to about 1300 angstroms. More preferably the peak macropore diameter of the zeolite catalyst is in the range of about 600 angstroms to about 1100 angstroms, and most preferably the peak macropore diameter of the zeolite catalyst is in the range of about 750 angstroms to about 900 angstroms.
The zeolite Y has a silica to alumina molar ratio of about 5:1 to about 100:1 and the mordenite zeolite has a silica to alumina molar ratio of about 50:1 to about 105:1. Preferably the zeolite Y has a silica to alumina molar ratio of about 30:1 to about 90:1, and more preferably the zeolite Y and the mordenite zeolite independently has a silica to alumina molar ratio of about 60:1- to about 80:1.
The zeolite catalyst may contain a binder. Preferably, the binder is alumina.
The zeolite catalyst may be in the form of a tablet.
Yet another embodiment of the present invention is directed to a zeolite catalyst composition having a macropore structure comprising:
(a) zeolite Y; and (b) mordenite zeolite having a silica to alumina molar ratio in the range of about 50:1 to about 105:1;
wherein the peak macropore diameter of the catalyst composition, measured by ASTM Test No. D 4284-03, is less than about 2000 angstroms and the cumulative pore volume of the catalyst at pore diameters less than or equal to about 500 angstroms, measured by ASTM Test No. D 4284-03, is less than or equal to about 0.30 milliliters per gram.
The cumulative pore volume of the zeolite catalyst composition at pore diameters less than or equal to about 400 angstroms is less than or equal to about 0.30 milliliters per gram. Preferably, the cumulative pore volume zeolite catalyst composition at pore diameters less than or equal to about 300 angstroms is less than or equal to about 0.25 milliliters per gram. More preferably, the cumulative pore volume zeolite catalyst composition at pore diameters less than or equal to about 300 angstroms is less than or equal to about 0.20 milliliters per gram.
The cumulative pore volume of the zeolite catalyst composition at pore diameters less than or equal to about 400 angstroms may be in the range of about 0.05 milliliters per-gram to about 0.18 milliliters per gram. Preferably, the cumulative pore volume of the zeolite catalyst composition at pore diameters less than or equal to about 300 angstroms is in the range of about 0.08 milliliters per gram to about 0.16 milliliters per gram.
The peak macropore diameter of the zeolite catalyst composition is in the range of about 400 angstroms to about 1500 angstroms. Preferably, the peak macropore diameter of the zeolite catalyst composition is in the range of about 500 angstroms to about 1300 angstroms. More preferably the peak macropore diameter of the zeolite catalyst composition is in the range of about 600 angstroms to about 1100 angstroms, and most preferably the peak macropore diameter of the zeolite catalyst composition is in the range of about 750 angstroms to about 900 angstroms.
The zeolite Y in step (a) having a silica to alumina ratio of about 5:1 to about 100:1, preferably the zeolite Y has a silica to alumina molar ratio of about 30:1 to about 90:1, and more preferably the zeolite Y has a silica to alumina molar ratio of about 60:1 to about 80:1.
The mordenite zeolite in step (b) preferably has a silica to alumina molar ratio of about 60:1 to about 80:1.
The zeolite catalyst composition may contain a binder. Preferably, the binder is alumina.
The zeolite catalyst composition may be in the form of a tablet.
DETAILED DESCRIPTION OF THE INVENTION
Definitions
The term “alkylate” means an alkylated aromatic hydrocarbon.
The term “2-aryl content” is defined as the percentage of total alkylate (the alkylate species in which the alkyl chain derived from the olefin employed in the present alkylation process is attached to the aromatic ring) that is comprised of those chemical species in which the attachment of the alkyl chain to the aromatic ring is at the 2-position along the alkyl chain.
The term “binder” means any suitable inorganic material which can serve as matrix or porous matrix to bind the zeolite particles into a more useful shape.
The term “branched-chain olefins” means olefins derived from the polymerization of olefin monomers higher than ethylene and containing a substantial number of branches wherein the branches are alkyl groups having from about one carbon atom to about 30 carbon atoms. Mixtures of ethylene and higher olefins are also contemplated.
The term “calcining” as used herein means heating the catalyst to about 400° C. to about 1000° C. in a substantially dry environment.
The term “carbonated, overbased” is used to describe those alkaline earth metal alkyl aromatic sulfonates in which the ratio of the number of equivalents of the alkaline earth metal moiety to the number of equivalents of the aromatic sulfonic acid moiety is greater than one, and is usually greater than 10 and may be as high as 20 or greater.
The term “cumulative pore volume” obtained by Mercury Intrusion Porosimetry as used herein refers to that part of the total volume in milliliters per gram derived from the graphical, cumulative pore volume distribution, measured by Section 14.1.6 of ASTM D 4284-03, or the corresponding tabular presentation of the same data between defined upper and lower pore diameters. When no lower diameter limit is defined, the lower limit is the lowest detection limit or lowest radius measured by Section 14.1.6 of ASTM D 4284-03.
The terms “dry basis”, “anhydrous basis”, and “volatiles-free basis” shall refer to the dry weight of catalyst composite or raw materials expressed on a metal oxides basis such as Na 2 O.Al 2 O 3 .xSiO 2 .
The term “flush” as used herein means contacting the deactivated mordenite catalysts and mordenite catalyst composites of this invention in the reactor with a suitable solvent, such as an aromatic hydrocarbon for reactivation of the mordenite catalysts and mordenite catalyst composites.
The term “loss-on-ignition (LOI)” as used herein means the percent weight loss of the zeolite composite and raw material samples which volatilize or evaporate when heated to 538° C. for 1 hour. When the temperature is greater than or equal about 538° C., the “loss-on-ignition” approximates the percent volatiles.
The terms “macropore”, “mesopore”, and “micropore” as used herein follow the definitions set forth by the International Union of Pure and Applied Chemistry (IUPAC), Division of Physical Chemistry, in Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II Definitions, Terminology and Symbols in Colloid and Surface Chemistry Part I, Adopted by the IUPAC Council at Washington, D.C., USA, on 23 Jul., 1971. Pores with widths or diameters exceeding ˜50 nanometers (500 angstroms) are called “macropores”. Pores with widths or diameters not exceeding ˜2.0 nanometers (20 angstroms) are called “micropores”. Pores of intermediate size (2.0 nanometers<width or diameter≦50 nm) are called “mesopores”.
The term “Mercury Intrusion Porosimetry” refers to the ASTM Test No. D 4284-03 used to determine pore volume distribution of catalysts by Mercury Intrusion Porosimetry. Mercury pore distribution was measured using a Quantachrome Scanning Mercury Porosimeter Model SP-100. The software version used by the instrument is V2.11 (dated Oct. 27, 1993). Surface tension used in the calculation is 473 dynes per centimeter and the contact angle is 140 degrees.
The terms “normal alpha olefin” and “linear alpha olefin” mean those straight-chain olefins without a significant degree of alkyl branching in which the carbon to carbon double bond resides primarily at the end or “alpha” position of the carbon chain, i.e., between C 1 and C 2 . Normal alpha olefins are derived from polymerization of ethylene.
The term “normal alpha olefin isomerization” means the conversion of normal alpha olefins into isomerized olefins having a lower alpha olefin content (the double bond is between C 1 and C 2 ), higher internal olefin content (the double bond is in positions other than between C 1 and C 2 ), and optionally a higher degree of branching.
The term “partially-branched chain olefin” is defined as the olefin product of isomerization of normal alpha olefins wherein the degree of branching is higher than in the starting normal alpha olefins.
The term “peak macropore diameter” as used herein means the peak diameter (i.e., the diameter within the macropore region at which the differential plot of pore size distribution, as defined by Section 14.2, reaches a maximum) in the macropore range determined by ASTM Test No. 4284-03 for the macropore peak in the catalysts of the present invention.
The term “peptizing” means the dispersion of large aggregates of binder particles, including hydrated aluminas, into much smaller primary particles by the addition of acid.
The term “percent volatiles” as used herein means the difference between the actual weight of the catalyst composite or the raw materials and the weight of the material on a dry, anhydrous, or volatiles-free basis, expressed as a percentage of the actual sample weight.
The term “SAR” or “silica to alumina ratio” refers to the molar ratio of silicon oxide to aluminum oxide; mol SiO 2 :mol AlO 3 .
The term “sufficient water to shape the catalyst material” means quantity of water required to make an acid peptized mixture of zeolite and alumina powders into an extrudable mass.
The term “tabletting” as used herein refers to the process of forming a catalyst aggregate from zeolite powder or a mixture of zeolite and binder powders by compressing the powder in a die.
The term “total pore volume” obtained by Mercury Intrusion Porosimetry as used herein refers to the total pore volume in milliliters per gram derived from the graphical, cumulative pore volume distribution (Section 14.1.6 of ASTM D 4284-03) or the corresponding tabular presentation of the same data.
As used herein, all percentages are weight percent, unless otherwise specified.
As noted above, the present invention is directed to novel alkylated aromatic compositions and their sulfonated and carbonated products. The alkylation of the aromatic hydrocarbons is carried out in the presence of the zeolite catalyst compositions of the present invention having a controlled macropore structure comprising zeolite Y and mordenite zeolite. The catalysts of the present invention were characterized by pore volume distribution obtained by Mercury Intrusion Porosimetry, ASTM Test No. D 4284-03. Mercury Intrusion Porosimetry provides a graph of cumulative pore volume (pv) versus pore diameter (pd). Mercury Intrusion Porosimetry also is used to determine the macropore peak diameter from the derivative, delta pv (Δpv) divided by delta pd (Δpd). The graphs are used to characterize the catalysts of the present invention.
The zeolite catalyst compositions were prepared using zeolite Y and mordenite zeolite. Zeolite Y and mordenite zeolite may also be combined to prepare zeolite catalyst compositions of the present invention. When the zeolite catalyst compositions contain both zeolite Y and mordenite zeolite, the zeolite catalyst composite may be prepared by mixing zeolite Y and mordenite zeolite powders before the binding and shaping steps. The zeolite Y CBV 760® and CBV 600® available from Zeolyst International having a nominal silica to alumina ratio of 60 and 6.7, respectively, may be used for preparing the zeolite catalyst compositions of this invention. However, zeolite Y having a silica to alumina ratio between 5 and 110 may be used for the preparation of the zeolite catalysts compositions of the present invention. The mordenite zeolite 90A® having a nominal silica to alumina ratio of 90, also available from Zeolyst International, may be used for preparing the zeolite catalyst compositions of this invention. Mordenite zeolite having a silica to alumina ratio of 50 to 105 may be used in the preparation of the zeolite catalyst compositions of this invention.
The catalysts of the present invention may be shaped or formed into tablets, extrudates or any other shape using procedures well known in the prior art. The preparation of extrudates requires the presence of a binder, such as alumina. The tabletted catalysts do not require the presence of a binder, but a binder may be present in a tabletted zeolite catalyst. The crystalline zeolite powder may be compressed to form a tablet. The tabletted catalysts of the present invention provide exceptionally low deactivation rates in alkylation reactions.
The alkylation of aromatic hydrocarbons with one or more olefins may be carried out in a fixed bed reactor in the presence of the zeolite catalysts compositions of the present invention comprising only zeolite Y, only mordenite zeolite, or both zeolite Y and mordenite zeolite. The alkylation process is conducted without the addition of water and using dried aromatic hydrocarbon and olefin feed. It is believed that the presence of water during the alkylation increases the deactivation rate of the catalysts of this invention. When the alkylation using zeolite Y and mordenite zeolite is carried out in separate fixed bed reactors, the alkylated aromatic hydrocarbons may be combined to obtain the desired amount of alpha olefins versus branched-chain olefins. Alkylation reactions using normal alpha olefins and zeolite catalysts compositions comprising only mordenite zeolite give predominantly alkylated aromatic hydrocarbons wherein the attachment of the of the alkyl chain to the aromatic ring is at the 2-position along the alkyl chain. On the other hand, alkylation reactions using zeolite catalysts compositions comprising only zeolite Y and normal alpha olefins give predominantly attachments at other than the 2-position along the alkyl chain.
The alkylation reaction may be carried out by any conventionally known process. The aromatic hydrocarbon is reacted with one or more olefins in the presence of a catalyst of the present invention under alkylation reaction conditions. The above alkylation process is conducted without the addition of water and using dried aromatic hydrocarbon and olefin feed. It is believed that the presence of water during the alkylation process increases the deactivation rate of the catalysts of this invention.
The aromatic hydrocarbon may be single-ring or double-ring, preferably the aromatic hydrocarbon is a single-ring aromatic hydrocarbon. The aromatic hydrocarbon may be an alkylated aromatic hydrocarbon, such as a mono-alkylated aromatic hydrocarbon, wherein the alkyl group has from about 4 carbon atoms to about 80 carbon atoms. When the aromatic hydrocarbon used is a mono-alkylated aromatic, the product of the alkylation reaction is a di-alkylated aromatic hydrocarbon.
The olefins useful for alkylation of the aromatic hydrocarbons may be linear-chain olefins or branched-chain olefins having from about 4 carbon atoms to about 80 carbon atoms. In addition, normal alpha olefins may be isomerized to obtain partially-branched-chain olefins for use in alkylation process of the present invention. These resulting partially-branched-chain olefins may be alpha-olefins, beta-olefins, internal-olefins, tri-substituted olefins, and vinylidene olefins.
Alkylated aromatic hydrocarbon sulfonic acids of the alkylated aromatic hydrocarbons of the present invention may be prepared by any known sulfonation reaction. The alkylated aromatic sulfonic acids may be further reacted with an alkaline earth metal and carbon dioxide to obtain carbonated, overbased alkylated aromatic sulfonates useful as detergents in lubricating oils. Carbonation may be carried out by any conventionally known process. The degree of overbasing may be controlled by changing the reaction conditions and the amount of the alkaline earth metal and carbon dioxide used in the carbonation process.
The novel alkylation compositions of the present invention may be obtained by conducting the alkylation reactions as described above in the presence of the zeolite catalyst compositions of the present invention prepared as described in Examples 1–4 below.
Procedure for Isomerization of Normal Alpha Olefins
The isomerization process may be carried out in batch or continuous mode. The process temperatures can range from 50° C. to 250° C. In the batch mode, a typical method is to use a stirred autoclave or glass flask, which may be heated to the desired reaction temperature. A continuous process is most efficiently carried out in a fixed bed process. Space rates in a fixed bed process can range from 0.1 to 10 or more weight hourly space velocity.
In a fixed bed process, the isomerization catalyst is charged to the reactor and activated or dried at a temperature of at least 150° C. under vacuum or flowing inert, dry gas. After activation, the temperature of the isomerization catalyst is adjusted to the desired reaction temperature and a flow of the olefin is introduced into the reactor. The reactor effluent containing the partially-branched, isomerized olefins is collected. The resulting partially-branched, isomerized olefins contain a different olefin distribution (alpha olefin, beta olefin, internal olefin, tri-substituted olefin, and vinylidene olefin) and branching content than the unisomerized olefin.
Procedure for Alkylation of Aromatic Hydrocarbons
Alkylation of aromatic hydrocarbons with normal alpha olefins, partially-branched-chain isomerized olefins, and branched-chain olefins may be carried out by any method known by a person skilled in the art.
The alkylation reaction is typically carried out with an aromatic hydrocarbon and an olefin in molar ratios from 1:15 to 25:1. Process temperatures can range from about 100° C. to about 250° C. The process is carried out without the addition of water. As the olefins have a high boiling point, the process is preferably carried out in the liquid phase. The alkylation process may be carried out in batch or continuous mode. In the batch mode, a typical method is to use a stirred autoclave or glass flask, which may be heated to the desired reaction temperature. A continuous process is most efficiently carried out in a fixed bed process. Space rates in a fixed bed process can range from 0.01 to 10 or more weight hourly space velocity.
In a fixed bed process, the alkylation catalyst is charged to the reactor and activated or dried at a temperature of at least 150° C. under vacuum or flowing inert, dry gas. After activation, the alkylation catalyst is cooled to ambient temperature and a flow of the aromatic hydrocarbon compound is introduced, optionally toluene. Pressure is increased by means of a back pressure valve so that the pressure is above the bubble point pressure of the aromatic hydrocarbon feed composition at the desired reaction temperature. After pressurizing the system to the desired pressure, the temperature is increased to the desired reaction temperature. A flow of the olefin is then mixed with the aromatic hydrocarbon and allowed to flow over the catalyst. The reactor effluent comprising alkylated aromatic hydrocarbon, unreacted olefin and excess aromatic hydrocarbon compound are collected. The excess aromatic hydrocarbon compound is then removed by distillation, stripping, evaporation under vacuum, or any other means known to those skilled in the art.
Procedure for Sulfonation of Alkylated Aromatic Hydrocarbons
Sulfonation of alkylated hydrocarbons may be carried out by any method known by a person skilled in the art.
The sulfonation reaction is typically carried out in a falling film tubular reactor maintained at about 65° C. The alkylated aromatic hydrocarbon is placed in the tube and sulfur trioxide diluted with nitrogen is added to the alkylated aromatic hydrocarbon. The molar ratio of alkylated aromatic hydrocarbon to sulfur trioxide is maintained at about 1.05:1. The resulting alkylated aromatic sulfonic acid may be diluted with about 10% 100 Neutral oil followed by thermal treatment with nitrogen bubbling at a rate of about 10 liters per kilogram of product and stirring while maintaining the temperature at about 85° C. until the desired residual sulfuric acid content is obtained (maximum of about 0.5%).
Procedure for Carbonation, Overbasing of Alkylated Aromatic Sulfonic Acids
Carbonation, overbasing of alkylaromatic sulfonic acids may be carried out by any method known by a person skilled in the art to produce alkylaromatic sulfonates.
Generally, the carbonation, overbasing reaction is carried out in a reactor in the presence of the alkylated aromatic sulfonic acid, diluent oil, an aromatic solvent, and an alcohol. The reaction mixture is agitated and alkaline earth metal and carbon dioxide are added to the reaction while maintaining the temperature between about 20° C. and 80° C.
The degree of carbonation, overbasing may be controlled by the quantity of the alkaline earth metal and carbon dioxide added to the reaction mixture, the reactants and the reaction conditions used during the carbonation process.
Reactivation of Deactivated Mordenite Zeolite Catalysts and Composites
Once the mordenite zeolite catalysts and catalyst composites are completely deactivated, the alkylation reaction stops because of the polymerization of the olefin into large molecular species that cannot diffuse out of the crystal micropores containing the active sites in the zeolitic material. However, reactor bed need not be changed to remove the deactivated mordenite zeolite catalysts and catalyst composites. The deactivated mordenite zeolite catalysts and catalyst composites are reactivated at the end of an alkylation run by stopping the olefin feed stream to the reactor and permitting the aromatic hydrocarbon stream to continue to be flushed through the reactor for a sufficient time, typically from about 12 hours to about 24 hours.
EXAMPLES
Example 1
Preparation of Zeolite Catalyst Composition 1
Zeolite Catalyst Composition 1 is prepared by mixing zeolite Y powder and mordenite zeolite powder available from Zeolyst International or any other commercial source. The zeolite Y and mordenite zeolite powders are mixed in any proportion based on the desired alkylated aromatic product.
As an example, zeolite Y catalyst powder is mixed with mordenite zeolite catalyst powder to obtain a final ratio of 85:15 in the final Zeolite Catalyst Composition.
Zeolite Catalyst Composition 1 is prepared by the following method:
Loss-on-ignition (LOI) is determined for samples of commercially available zeolite Y (CBV 760® and CBV 600®) and mordenite zeolite (CBV 90A®) available from Zeolyst International by heating the samples to 538° C. for 1 hour. The LOI obtained provides the percent volatiles in the zeolite Y and mordenite zeolite batches being used. The LOI of a commercial sample of Versal® hydrated aluminum oxide available from Sasol is also obtained by heating the samples to 538° C. for 1 hour. Next, based on the results obtained from the LOI of the zeolite Y, mordenite zeolite and the alumina powders the amount of alumina powder is weighed out to obtain 80% (volatile-free basis) zeolite content of the composite consists of 85% zeolite Y and 15% mordenite zeolite on a volatile-free basis.
The three dry powders are added to a Baker Perkins mixer and dry mixed for 4 minutes. The amount of concentrated (70.7%) nitric acid to give 0.7 weight % (based on 100% nitric acid) of the dry weight of the zeolite and the alumina powders is calculated. This amount of 70.7% nitric acid was weighed out and dissolved in deionized water.
The total amount of water and 70.7% nitric acid needed to obtain a final concentration of approximately 50% total volatiles is calculated as follows. Volatiles in the Y zeolite, mordenite zeolite and alumina powders is calculated. Nitric acid solution is considered to be 100% volatiles. Thus, the amount of deionized water that must be added is the difference between the final concentration of volatiles of 50% minus the total volatiles in the three powders.
Deionized water is added over a period of 5 minutes to the powders in the mixer using a peristaltic pump. The mixer is then stopped so that the walls of the mixer can be scraped down. Mixing is then resumed and the solution of nitric acid in water is added over 5 minutes using the peristaltic pump. At the end of acid addition, mixing is continued for a total time of 40 minutes, with occasional holds to allow for scraping the sides of the mixer. At the end of the mixing period, the percent volatiles are measured. Additional amounts of deionized water is added until the mixture appears extrudable and the percent volatiles are again measured.
The wet mixture is extruded through 1.27 millimeters, asymmetric quadrilobe die inserts, in a Bonnot extruder. The wet long cylindrical strands are dried at 121° C. for 8 hours. The long cylindrical strands are then broken to give extrudates with length to diameter ratio of 2:6. The extrudates are sieved and the portion larger than 1.0 millimeter is retained.
The extrudates are then calcined in a muffle furnace using the following temperature program:
The extrudates are heated to 593° C. over two hours, then held at 593° C. for ½ hour and next cooled to 204° C. A total weight of the extrudates is obtained.
Mercury Intrusion Porosimetry is used to characterize the extrudates. A peak macropore diameter in angstroms and a cumulative pore volume at diameters less than 300 angstroms is obtained from the Mercury Intrusion Porosimetry data.
The Zeolite Catalyst Composition is charged to a pilot plant reactor used for the alkylation of aromatic hydrocarbons. The reaction effluent of this reactor has greater than or equal to 99% conversion of the olefin feed stream. When benzene is used as the aromatic hydrocarbon and the alkylation reaction is conducted using the Zeolite Catalyst Composition, there is a much higher attachment of the alkyl chain to the aromatic ring at the 2-position along the alkyl chain in the alkylated benzene than when the zeolite Y catalyst composite is used alone in the alkylation reaction.
Excess benzene is removed by distillation, stripping or any other suitable means and the alkylated benzene is sulfonated using sulfonation procedures well known in the art. The alkyl benzene sulfonic acid is further carbonated with an alkaline earth metal and carbon dioxide.
Example 2
Preparation of Zeolite Y Catalyst Composite
Zeolite Y Catalyst Composite was prepared are described above in Example 1 using zeolite Y CBV 760® available from Zeolyst International.
Example 3
Preparation of Mordenite Zeolite Catalyst Composite
Mordenite Zeolite Catalyst Composite was prepared are described above in Example 1 using mordenite zeolite CBV 90A® available from Zeolyst International.
Example 4
Preparation of Zeolite Catalyst Composition 2
Zeolite Catalyst Composition 2 is prepared by mixing Zeolite Y Catalyst Composite and Mordenite Zeolite Catalyst Composite prepared in Examples 2 and 3. The Zeolite Y Catalyst Composite and Mordenite Zeolite Catalyst Composite are mixed in any proportion based on the desired alkylated aromatic product. As an example, Zeolite Y Catalyst Composite is mixed with Mordenite Zeolite Catalyst Composite to obtain a final ratio of 85:15 in the Zeolite Catalyst Composition 2.
The resulting Zeolite Catalyst Composition 2 is charged to a pilot plant reactor for the alkylation of aromatic hydrocarbons as described below in Example 5.
Example 5
Preparation of Alkylbenzene Compositions Using Zeolite Y Catalyst Composite
Typically, alkylation of aromatic hydrocarbons with normal alpha olefins, partially-branched-chain isomerized olefins and branched-chain olefins was carried out as described below:
A fixed bed reactor constructed from 15.54 millimeters Schedule 160 stainless steel pipe was used for this alkylation test. Pressure in the reactor was maintained by an appropriate back pressure valve. The reactor and heaters were constructed so that adiabatic temperature control could be maintained during the course of alkylation runs. A 192 gram bed of 850 micrometer to 2 millimeters Alundum particles was packed in the bottom of the reactor to provide a pre-heat zone. Next, 100 grams of a zeolite Y catalyst composite similar to the zeolite Y catalyst composite prepared in Example 2 above was charged to the fixed bed reactor. The reactor was gently vibrated during loading to give a maximum packed bulk density of catalyst in the reactor. Finally, void spaces in the catalyst bed were filled with 351 grams 150 micrometers Alundum particles as interstitial packing.
The reactor was then closed, sealed, and pressure tested under nitrogen. Next, the alkylation catalyst was dehydrated during 15 hours at 200° C. under a 20 liters per hour flow of nitrogen measured at ambient temperature and pressure and then cooled to 100° C. under nitrogen. Benzene was then introduced into the catalytic bed in an up-flow manner at a flow rate of 195 grams per hour. Temperature (under adiabatic temperature control) was increased to a start-of-run temperature of 182° C. (measured just before the catalyst bed) and the pressure was increased to 14.6 atmospheres.
When temperature and pressure had lined out at desired start-of-run conditions of 182° C. and 14.6 atmospheres, a feed mixture, consisting of benzene and C 20-24 NAO at a molar ratio of 10:1 and dried over activated alumina, was introduced in an up-flow manner. As the feed reached the catalyst in the reactor, reaction began to occur and internal catalyst bed temperatures increased above the inlet temperature. After about 8 hours on-stream, the reactor exotherm was 20° C. At 26 hours on-stream, the olefin conversion in the product was 99.1%. The run was stopped after 408 hours on-stream, although the run could have continued. At this time, the olefin conversion was 99.45%.
Alkylated aromatic hydrocarbon products containing excess benzene were collected during the course of the run. After distillation to remove excess aromatic hydrocarbon, analysis showed that greater than 99% conversion of olefin was achieved during the course of the run.
A fixed bed reactor was constructed from 15.54 millimeters Schedule 160 stainless steel pipe. Pressure in the reactor was maintained by an appropriate back pressure valve. The reactor and heaters were constructed so that adiabatic temperature control could be maintained during the course of alkylation runs. A small amount of 850 micrometer to 2 millimeters acid-washed Alundum was packed in the bottom of the reactor to provide a pre-heat zone. Next, 100 grams of whole alkylation extrudate catalyst was charged to the fixed bed reactor. Finally, void spaces in the catalyst bed were filled with 150 micrometers acid-washed Alundum interstitial packing. The zeolite Y or the mordenite zeolite alkylation catalyst was then dehydrated for at least 8 hours at 200° C. under a flow of nitrogen gas and then cooled to ambient temperature under nitrogen gas. Benzene was then introduced into the catalytic bed in an up-flow manner. Temperature (isothermal temperature control) and pressure were increased at start of run conditions. Normal operating pressure was 11.91 atmospheres. The initial temperature of approximately 150° C. was chosen so that the temperature in the catalytic bed increased under adiabatic temperature control to about 160° C. to about 175° C. When temperature and pressure had lined out at desired start-of-run conditions, the reactor system was switched to adiabatic temperature control. A dried feed mixture, consisting of olefin and benzene, was introduced in an up-flow manner. The benzene to olefin molar ratio was 10:1. As the reaction began to occur, temperature increased in the catalyst bed above the inlet temperature.
Alkylated benzene product containing excess benzene was collected during the course of the run. After distillation to remove excess benzene, analysis showed that greater than 99% conversion of olefin was achieved during the course of the run.
Example 6
Preparation of Alkylbenzene Compositions
Typically, alkylation of aromatic hydrocarbons with normal alpha olefins, partially-branched-chain isomerized olefins and branched-chain olefins was carried out as described below:
A fixed bed reactor was constructed from 15.54 millimeters Schedule 160 stainless steel pipe. Pressure in the reactor was maintained by an appropriate back pressure valve. The reactor and heaters were constructed so that adiabatic temperature control could be maintained during the course of alkylation runs. A bed of 170 grams of 850 micrometer to 2 millimeters Alundum particles was packed in the bottom of the reactor to provide a pre-heat zone. Next, 100 grams of mordenite catalyst composite similar to the mordenite catalyst composite prepared in Example 3 above was charged to the fixed bed reactor. Finally, void spaces in the catalyst bed were filled with 309 grams of 150 micrometers Alundum particles interstitial packing. The reactor was gently vibrated while charging catalyst and alundum to ensure a high packed bulk density. After charging, the reactor was closed, sealed, and the pressure was tested.
The alkylation catalyst was then heated to 200° C. under a 20 liters per hour flow of nitrogen measured at ambient temperature and pressure and dehydrated for 23 hours at 200° C. The catalyst bed was then cooled to 100° C. under nitrogen. Benzene was then introduced into the catalytic bed in an up-flow manner at a flow rate of 200 grams per hour. Temperature (under adiabatic temperature control) was increased to a start of run inlet temperature of 154° C. (measured just before the catalyst bed) and the pressure was increased to 12.66 atmospheres.
When temperature and pressure had lined out at desired start-of-run conditions of 154° C. and 12.66 atmospheres, a feed mixture, consisting of benzene and C 20-24 NAO at a molar ratio of 15:1 and dried over activated alumina, was introduced in an up-flow manner at 200 grams per hour. As the feed reached the catalyst in the reactor, reaction began to occur and internal catalyst bed temperatures increased above the inlet temperature. After about 8 hours on-stream, the reactor exotherm was 20° C. In the first 57 hours on-stream, the olefin conversion decreased from 100% to 98.8% (Run Period 1). At this point, the catalyst bed was flushed with benzene at 200 grams per hour during 18 hours. Following the benzene flush, the benzene and olefin feed flow was resumed. Inlet temperature was increased to 162° C. at 57 run hours. Feed was continued until 351 run hours (Run Period 2 from 57 to 351 run hours). Olefin conversion was initially 98.9% during Run Period 2 but declined to 98.1% at 321 run hours and further to 95.3% at 351 run hours. A second benzene flush was performed at 351 run hours during 17 hours. After the second benzene flush, feed flow was resumed again to start Run Period 3. Feed was continued until 550 run hours. Olefin conversion was initially 98.5% but declined to 98.3% at 519 run hours and to 97.0% at 550 run hours. A third benzene flush was done during a weekend. Feed flow was resumed after the third benzene flush to begin Run Period 4. At the beginning of Run Period 4, olefin conversion was 98.8% and at 942 run hours the olefin conversion was 98.4%. The run was stopped after 942 hours on-stream but could have continued longer.
Alkylated aromatic hydrocarbon products containing excess benzene were collected during the course of the run. After distillation to remove excess aromatic hydrocarbon, analysis showed that greater than 97% conversion of olefin was achieved during most of the course of the run.
Example 7
Preparation of Alkylbenzene Sulfonic Acids
A mixture of 85 weight % of the alkylated benzene prepared using the zeolite Y catalyst and 15 weight % of the alkylated benzene prepared using mordenite zeolite catalyst as in Examples 5 and 6 above was sulfonated by a concurrent stream of sulfur trioxide (SO 3 ) and air with in a tubular reactor (2 meters long, 1 centimeter inside diameter) in a down flow mode using the following conditions:
Reactor temperature was 60° C., SO 3 flow rate was 73 grams per hour, and alkylate flow rate was 327 grams per hour at a SO 3 to alkylate molar ratio of 1.05. The SO 3 was generated by passing a mixture of oxygen and sulfur dioxide (SO 2 ) through a catalytic furnace containing vanadium oxide (V 2 O 5 ).
The resulting crude alkylbenzene sulfonic acid had the following properties based on the total weight of the product: weight % of HSO 3 was 15.61% and weight % of H 2 SO 4 was 0.53.
The crude alkylbenzene sulfonic acid (1665 grams) was diluted with 83 grams of 100 Neutral diluent oil and placed in a 4 liter four-neck glass reactor fitted with a stainless steel mechanical agitator rotating at about 300 rpm, a condenser and a gas inlet tube (2 millimeters inside diameter) located just above the agitator blades for the introduction of nitrogen. The contents of the reactor were placed under vacuum (40 millimeters Hg) and the reactor was heated to 110° C. with stirring and nitrogen was bubbled through the mixture at about 30 liters per hour for about 30 minutes until the weight % of H 2 SO 4 is less than about 0.3 weight %. This material is the final alkylbenzene sulfonic acid.
The final alkylbenzene sulfonic acid had the following properties based on the total weight of the product: weight % of HSO 3 was 14.95 and weight % of H 2 SO 4 was 0.17.
Example 7
Preparation of Alkylbenzene Sulfonates
To a 5 liter four-neck glass reactor equipped with heating and cooling capability and fitted with a stainless steel mechanical agitator rotating at between 300 and 350 rpm, a gas inlet tube (2 millimeters inside diameter) located just above the agitator blades for the addition of CO 2 , a distillation column and condenser under nitrogen gas was charged 129.4 grams of centrate.
The centrate was a mixture of the sludge fractions previously produced during the purification of high TBN carbonated, overbased synthetic sulfonates by centrifugation and decantation and was added to the reaction mixture of this example for recycling the contents of the centrate. The centrate had a TBN of 197 and contained approximately 73 grams of xylene solvent, 12 grams active calcium sulfonate, 9 grams calcium hydroxide and calcium carbonate, 8 grams of carbon dioxide, and 23 grams of 100 Neutral diluent oil.
Next, 40 grams of methanol, 207 grams of xylene solvent, 296.5 grams (0.59 mole) of the alkylbenzene sulfonic acid (HSO 3 was 14.95 weight % based on the total weight of the reaction mixture) from Example 6 above was charged to the reactor over 15 minutes at room temperature. A slurry of 160 grams (2.16 mole) of calcium hydroxide, 362 grams of xylene solvent and 94.2 grams of methanol was added to the reactor and the contents of the reactor were cooled to 25° C. Subsequently, 33 grams (0.79 mole) of CO 2 was added to the reactor through the gas inlet tube over 39 minutes while the temperature of the reactor increased to about 32° C. A second slurry composed of 160 grams (2.16 mole) of calcium hydroxide, 384 grams xylene solvent, and 131 grams of methanol was then added to the reactor concurrently with 0.9 grams of CO 2 over about 1 minute. Then 92 grams of CO 2 was added to the reactor over 64 minutes while the temperature of the reactor was increased from about 30° C. to about 41° C. A third slurry composed of 82 grams of oxide and 298 grams of xylene solvent was then charged to the reactor concurrently with 1.4 grams of CO 2 over about 1 minute. Next, 55 grams (1.25 mole) of CO 2 was added to the reactor over approximately 60 minutes while keeping the reactor temperature at approximately 38° C.
The water and methanol were then distilled from the reactor by first heating the reactor to 65° C. over about 40 minutes at atmospheric pressure and then to 93° C. over about 60 minutes at atmospheric pressure and then finally to 130° C. over about 30 minutes at atmospheric pressure. The temperature of the reactor was then decreased to 110° C. over about 60 minutes at atmospheric pressure and next then cooled to approximately 30° C. and 475.7 grams of 600 Neutral diluent oil was added to the reactor followed by 413 grams of xylene solvent. The sediment in the product was then removed by centrifugation. The xylene solvent in the product was distilled by heating the product to 204° C. over approximately 45 minutes at 30 millimeters Hg vacuum and holding the product at 204° C. and 30 millimeters Hg vacuum for 10 minutes. The vacuum was replaced with nitrogen gas and the contents allowed to cool to room temperature to obtain the overbased sulfonate having the following properties based on the total weight of the product:
The weight % of calcium was 16.2, TBN was 429, weight % of sulfur was 1.70, weight % of calcium sulfonate was 0.94, and viscosity was 111 cSt at 100° C. | 4y
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FIELD OF THE INVENTION
[0001] The present invention is generally in the field of kits, and more specifically concerns kits for domestic use for the self-detection of various physiological conditions.
BACKGROUND OF THE INVENTION
[0002] Parasitology is one of the very few remaining tests in clinical medicine which relies on the visual recognition skills of a trained technologist. It involves, in fact, two visual recognition skills. One is the identification of particular morphological features characterizing an organism as belonging to a certain species, and being able to recognize it by name. The other, and much more difficult skill is the ability to recognize old, young, damaged, deformed, or even partially degraded organisms—perhaps occurring only at the edge of a microscopic field—and know that it is a particular parasite. Such being the case, a negative result for a parasitology test only indicates that no parasite was found, and can not be conclusive that a patient is negative for parasites.
[0003] The problem of parasite identification for the laboratory is additionally difficult due to the fact that parasite frequency can vary widely, and may not have any relation to severity of disease. Parasite reports are typically graded from rare to many. It is possible, in fact for a person to have a serious parsitological infestation, but to have only infrequent, periodic, or occasional shedding of parasitic organisms. In the case of low frequency of occurrence in the stool, organisms may or may not be present in the particular specimens being examined under the microscope.
[0004] The problem of parasite identification for the laboratory is additionally complicated due to the fact that transportation of specimens from the patient to the clinical laboratory is usually delayed and during this delay the parasites may die or be degraded, thus decreasing even further the chances of identification.
[0005] Thus, the situation exists where many clinical laboratories fail to detect parasites which, in fact, are present in patient specimens. Clinical laboratory surveys in the United States frequently report a positive prevalence of parasites of 1-3%, and rarely over 5%. Yet various published studies by specialty, or university based laboratories, show that the true positive rate can be as much as 4- or 5- fold higher than
[0006] In response to this situation, parasitologists have developed methods of concentrating parasites and staining them with contrasting colors so as to improve recognition ability. Thus, a concentration procedure followed by a trichrome staining procedure has been developed as the standard method of properly performed parasitology analysis. This method, however, is laborious and time consuming. It is, therefore, not done by all labs all the time, in spite of recommendations to that effect. Even when performed, it does not address or solve all the problems mentioned above.
[0007] In recognition of this situation diagnostic device companies have developed tests for particular parasites. Notably tests for giardia lamblia, entamoeba histolytica, and cryptosporidium sp. are commercially available. These take two forms, either being an ELISA test (i.e.: Alexon-Trend, Inc), or fluorescent tagging of the organisms followed by direct microscopic examination (ie:Meridian Diagnostics, Inc). The problem with these tests, however, is that they attempt to identify a particular organism, and not all organisms or the overall presence of parasites. Furthermore these tests require laboratory procedures and the intervention of skilled technicians.
[0008] The nature of parasite examination, and prevalence in the world, divides the parasites into two large groups: protozoans, and worms and eggs. Protozoans are single celled organisms, and are the most common parasites found in developed countries of the world. They are, also, as a rule, smaller than worms and eggs, and are examined on high power (40×) of the microscope. Worms and eggs on the other hand are multi-cellular organisms, and are very common in underdeveloped countries of the world. They are, as a rule, larger than protozoans and are examined at low power (10×) of the microscope.
[0009] What is needed by medical science and the market, therefore, are two tests—one for protozoans, and one for worms and eggs. It would be sufficient to identify those specimens which are positive and differentiate them from those that are negative. It would be even more advantageous, however, to identify specifically those particular parasites which are present in each specimen.
SUMMARY OF THE INVENTION
[0010] The present invention is based on the realization that there is a need for a non-invasive, fast, accurate, and user friendly method for diagnosing the presence of parasites, both protozoan and non-protozoan, in stool. The need is especially evident in view of the high false negative diagnosis of many standard laboratory tests and the high level of skill required to identify, under a microscope the instance and type of the parasite. The present invention is further based on the realization that detection of the presence of parasites in stool is of the type of detections which may be carried out at home, or at a doctor's clinic, without involving an analyzing laboratory, since the patient (or doctor) can easily understand a positive result of such a test, and proceeds to treat the parasite, with consultation with a doctor by the administration of anti-parasitic compounds. Furthermore, there is a great advantage of detecting parasites in fresh stool instead of waiting until the parasite reaches the laboratory resulting many times in non-viable or degraded parasites.
[0011] The present invention is further based on the realization that it is possible to develop a kit for such a non-invasive, reliable and home (and practitioner's office) testing.
[0012] Thus the present invention by its first aspect concerns a home kit for detection of the presence of a parasite in a stool sample, the kit comprising:
[0013] (a) a vessel for mixing a stool specimen with a diluting liquid to produce a diluted stool specimen;
[0014] (b) a housing holding within a substrate, the substrate comprising at least one zone containing at least one anti-parasitic antibody, the housing further comprising reagents for producing a visually detected reaction when an antibody-parasite antigen complex is formed, the housing further comprising at least one conveying means for receiving diluted stool specimen and transferring it to the anti-parasitic antibody containing zone of the substrate;
[0015] (c) the housing further comprises an indicator for showing the presence of the visually detected reaction.
[0016] Preferably the anti-parasitic antibodies are polyclonal, in order to ensure that they interact effectively with all varieties of a specific specie of parasites. The antibodies may be prepared by any method known in the art, for example, by immunizing an animal with a suitable parasite or an immunogenic portion thereof, and then collecting the antibodies produced. Where the antibody is monoclonal, it should be against a conserved epitope of the specific parasite spears which is common to any many varieties of the parasite species as possible.
[0017] The antibodies may be against an immunogenic epitope present on the external surface of the protozoa or non-protozoa parasite, or against an immunogenic epitope of a compound shed of secreted from the parasites, such as parasite eggs.
[0018] The term “home kit” in the context of the present invention refers to the fact that the kit of the invention, and the detection reaction produced therein, does not necessitate any complicated machinery for collecting the specimen and preparing it, for positioning the specimen in the kit, and for reading and interpreting the results—and typically, the results can be viewed by the naked eye, or by simple optical reactor. The term does not necessarily mean that the kit is only operable at home, since due to its non-invasiveness and it is easy, user friendly manner of operation, it can be also used in a practitioner's office or even in hospitals without involving an analytical laboratory.
[0019] The kit of the present invention comprises a vessel in which a small amount of stool specimen can be placed and diluted by a suitable diluting liquid. The vessel can then be sealed and the stool and diluting liquid shaken to produce a diluted stool specimen. The diluting liquid may be plain tap water, but according to a preferred embodiment of the invention the diluting liquid is, saline, distilled water, 10% formalin solution, sodium acetate solution with or without detergent and the like, and this diluting liquid is also provided as part of the kit's present invention, either a priori present inside the vessel or in a separate container.
[0020] The vessel may be for example in the form of a regular capped tube, having graduations, which indicate the volume of the raw stool specimen which is to be placed inside the tube, as well as the amount of the diluting liquid to be added.
[0021] The kit may also comprise a construction for collecting the stool, such as a disposable sheet to be placed inside a toilet bowl, a disposable vessel for stool collection, etc., as well as a scooping device, for example in the shape of a small spoon to pick a determined amount of stool. The scooping device (scoop) may be an integral part of the vessel's cap.
[0022] The kit's main component is a housing which holds within a substrate. For example the housing may be a plastic container. The substrate may be sandwiched between two layers of the plastic container. On a predefined zone of the substrate are present antibodies against at least one parasite, and by a preferred embodiment they are immobilized on that zone. Examples of the substrates are absorbent material such as nitrocellulose sheets, gel-films, cellulose acetate, fiberglass sheet, paper, agarose gels, and in general any media featuring capillary force or absorbent forces of fluid. Typically the housing has at least one conveying means which can receive the diluted stool specimen and transfer it to said zone. The conveying of the liquid may be by capillary or absorbing flow, which are due to the inherent properties of substrate, or the inherent properties of a specifically desired layer or by the construction of specific flow channels which bring the fluid to the antibody-containing zone.
[0023] By one option the conveying means are a combination of an opening in the container which opening is associated with a construction which can transfer to diluted stool specimen to the zone on the substrate which holds the anti-parasite antibody and where the antibody-antigen interaction takes place. For example, the conveying means are in the shape of an opening in the housing through which a small amount of the diluted stool can be poured. The stool is then transferred to the antibody containing zone of the substrate, for example, by capillary forces either of the substrate itself (which is made of absorbent material) or by capillary or absorbent forces of a specially designed layer which sole purpose is to transfer the diluted stool to the antibody-containing zone, or by flow in specially designed channels.
[0024] By another option the conveying means is an absorbent material or material composed of capillaries which protrudes out of the housing, for example, an absorbent wick protruding out of an opening in the housing. In such a case the protruding substrate material is dipped in the diluted stool and due to capillary forces the liquid is transferred to the antibody-containing zone which is present inside the housing.
[0025] The anti-parasite antibodies may be immobilized on the substrate by any interaction such as covalent bonds, hydrogen bonds, electrostatic forces contained within voids of beads, etc.
[0026] Typically, large particles have to be filtered out of the diluted stool before the diluted stool is conveyed to the antibody-containing zone of the substrate. Said filtering may take place in the vessel itself, for example by constructing a two part cap: the more distal part serving as a seal, which hermetically closes the vessel and allows the user to vigorously mix its contents. However, this cap may be opened fully or partially to expose below a filter sieve which can ensure that only relatively small particles are poured from the vessel into the convening means.
[0027] Alternatively, the housing itself may comprise said filtering sieve, which for example may be present either at the mouth of the opening of the convening means, or may be present as a continuous filter sieve layer above the substrate zone on which the anti-parasite antibodies are present.
[0028] By a preferred option where the substrate is an absorbent material, the stool particles may be sieved on its upper layers of the substrate so that a filtered specimen reaches the layer of immobilized antigen.
[0029] By one embodiment, the kit may comprise a single parasite in stool antigen and in such a case it can give a binary (yes/no) indication, whether the stool contains that parasite. Alternatively, the indication may be quantitative, for example, by giving three shades of the same color—a darker shade indicating “high” (amount of parasites in stool), than medium shade “medium”, and light shade “low”.
[0030] By a preferred embodiment, the kit of the present invention is used to detect a plurality of different parasites, and in such a case it is possible to determine, in a single assay, whether the individual has a parasite in his/her stool and which type.
[0031] Kits in accordance with a preferred embodiment are generally divided into two groups according to the parasites to be detected; kits or the detection of protozoa parasites and kits for the detection of non-protozoa parasites.
[0032] The kits for the detection of fecal protozoan parasites are for the detection of protozoa (single cell parasite): Amoeba histolytica, Amoeba hartmanni, Amoeba coli, Amoeba nana, Giardia lamblia, , Cryptosporidium sp., Blastocystis hominis, Chilomastix mesnili, lodamoeba butschlii, Dientamoeba fragillis.
[0033] The kits for the detection of fecal non-protozoan parasites are for the detection of Platyhelminthes (flat worms): flukes (liver, intestines, lungs and blood) and tapeworms (intestines), Nemathelminthes (round worms); Strongyloides, Trichuris, Trichinella, Pin worms, Ascaris, et al.
[0034] Preferably the kits of the invention are for the detection of protozoa parasites.
[0035] The kits of the invention may be used for human and veterinary usage. Many times domestic animals and pets suffer from the same parasite problems as humans and the kit of the invention may be used to detect parasites in animal stools.
[0036] Typically, regions of the substrate surrounding the zone on which the anti-parasite is immobilized are saturated by non-specific hydrophilic polymers such as bovine serum albumin, other proteins, or polyethylene glycol to block unspecific binding of the antibody to the substrate.
[0037] Interaction between the anti-parasite antibodies, a priori present in the kit, and parasites or parasitic components (for example, epitopes shed or secreted by parasites, for example, eggs which are present in the stool specimen, yields an antigen-antibody complex. In the kit of the invention the presence of such a complex should produce a visually detected reaction—i.e. a reaction which produces a visible indication, which may be viewed either by the naked eye, or by an optical reader. Examples of such a reaction is a color reaction (achieved by ELISA method) or a precipitation reaction which can easily be detected. A plurality of methods for producing visually detected reaction for antigen-antibody complexes are well known in the art, for example, as specified in “Immunoassay Handbook”. by David Wild, 2 nd Edition, Nature Publishing Group, pp 159-175, 271-277). An example is indirect ELISA, a procedure which is used to identify the presence of the stool antigen utilizing, for example, antibodies against the parasites conjugated to a visually detectable moiety (such as gold particles) or conjugated to an enzyme producing a color reactor). Another possibility is by detection of the presence of antibody-antigen aggregates, by visually detectable precipitation reaction.
[0038] The indicator is typically an opening in the housing (“a window”), which allows direct viewing of the visually detected reaction. Typically the opening is immediately above the region on which the antibodies are immobilized. The view may be by the naked eye, for example, by the detection of a colored bar, or a colored dot, or alternatively may be viewed by an optical reader, to increase sensitivity.
[0039] Where a single parasite is to be detected, a single indicator can be used which when showing the indicator (color bar, dot, etc.) indicates that there exists the specific parasite in the stool.
[0040] Where a plurality of parasites are to be detected, a plurality of indicators (windows) can be used so that each indicator is associated with a single parasite. Alternatively, a single indicator giving different readings can be used wherein each reading is in accordance with the specific antigen-antibody complex formed and thus each reading is indicative of a different parasites, present in the sample.
[0041] For example, where five different parasites are to be tested, it is possible to construct a housing with five different and separate anti-parasite-antibody containing substrate zones, so that in each zone a different anti-parasite-antibody will be immobilized, and for each zone there will be associated a separate indicator. This will ensure that the visually detected reaction in each zone is specific to the anti-parasite antibody (and hence parasite) present on the substrate of said zone, and the indicator (“window”) will simply be specifically associated with each zone. In the above case the housing may have a single means convening for example in the form of an absorbent layer.
[0042] The liquid stool specimen is poured into an opening, and due to the fact that the substrate is absorbent, capillary forces present in the absorbent material, cause transfer of the diluted stool specimen through all the separate zones on which are immobilized different anti-parasite antibodies. Then, the specific visually detected reaction is formed in each separate zone which reaction can be viewed by the specific indicator associated with that zone (for example by a “window” in the container through which a colored bead can be viewed).
[0043] In accordance with a preferred embodiment of the invention, the kit also contains internal control. The internal control is composed of those parasitic epitopes which specifically interact with the immobilized antibodies, present a priori, in the zone of the antibodies. The purpose of these, a priori, present parasitic antigens, is to form aggregates with the anti-parasitic antibody, to produce a visually detected reaction, in order to determine that the reagents used for producing the reaction are functioning properly.
[0044] The antibodies detected by the kit of the invention may be any antibody, monoclonal or polyclonal against a parasite.
[0045] As indicated above, polyclonal antibodies are preferred for ensuring that they react with all varieties of the species of parasites tested. Monoclonal antibodies are used and they should be directed against an epitope conserved in all varieties of the parasite species.
[0046] The present invention also concerns a method for detecting the presence of a parasite in a stool sample, the method comprising:
[0047] (a) obtaining a stool specimen;
[0048] (b) diluting the stool specimen with a diluting liquid to produce a diluted stool specimen;
[0049] (c) introducing the stool specimen into the kit of the invention; and
[0050] (d) viewing the indicator, the presence of a visually detected reaction in the indicator, indicating the presence of the parasite in the stool.
BRIEF DESCRIPTION OF THE DRAWINGS
[0051] In order to understand the invention and to see how it may be carried out in practice, a preferred embodiment will now be described, by way of non-limiting example only, with reference to the accompanying drawings, in which:
[0052] [0052]FIG. 1 shows a schematic representation of the components of the kit of the invention;
[0053] [0053]FIG. 2A shows one embodiment of the housing of the invention having the substrate fully contained within the housing, for detecting the presence of a single parasite in the stool;
[0054] [0054]FIG. 2B shows another embodiment of the housing of the type shown in FIG. 2A for detecting the presence of a plurality of parasites in the stool;
[0055] [0055]FIG. 3A shows an embodiment of a housing containing a substrate protruding out of the housing for detecting the presence of a single parasite in the stool; and
[0056] [0056]FIG. 3B shows a housing containing a substrate protruding out of the housing for detecting a plurality of parasites in the stool.
DETAILED DESCRIPTION OF THE INVENTION
[0057] Reference is made to FIG. 1 which shows basically an example of the various components of the kit of the invention.
[0058] The main component of the kit of the invention is a housing 10 holding within a substrate on which are immobilized various anti-parasite antibodies, as will be explained in more detail in FIGS. 2 and 3 and on which, the detection actually takes place. In addition, the kit comprises a vessel 11 into which a stool specimen is placed. Typically it is capable of holding about 5-10 cc of liquid. Cap 13 of the vessel is engagable with vessel 11 , and once closed can form a hermetically closed seal so that the vessel can be vigorously shaken to dilute the stool specimen with the diluting liquid. The vessels may be marked by graduations 12 which show the amount of liquid present within.
[0059] By the embodiment shown in FIG. 1, the cap 13 has as an integral part also scooping spoon 14 which can pick up a small amount of stool, and once the cap is fully engaged with the tube 11 , the spoon is immersed inside the liquid in the tube and thus cause dilution of the stool. The kit also comprises liquid bottles 15 which may contain, for example, the diluting liquid, and in some cases, reagents required to produce a color reaction (to be specified in more detail hereinafter). Finally, the kit also contains a device 16 , in the form of a small disposable container, for collecting the stool.
[0060] Where it is desired to add reagents present in bottle 15 , the kit may also contain a small pipette 17 .
[0061] Reference is now made to FIG. 2A which shows the housing of the kit of the present invention 20 . Typically, the housing is made out of plastic material, and holds within an absorbent material such as nitrocellulose. In the housing, three openings are evident, 21 , 22 and 23 . Into opening 21 , a minute amount of diluted stool sample is poured. Then, due to the capillary forces of the nitrocellulose substrate present within housing 20 , the liquid advances towards opening 22 and 23 . Opening 22 (T) is the test indicator and present above the region of the substrate on which the anti-parasitic antibodies against one species of parasites to be determined in the stool are immobilized. If the stool sample contains parasites or parasite portions reactive with the immobilized antibody on the substrate in region 22 , an antibody-antigen aggregate is formed, which can be viewed, for example, as a dark dot in opening 22 .
[0062] Opening 23 is a control zone C in opening 22 , and in that zone, a priori, are present already aggregates of the parasitic antigens bound to the anti-parasitic antibodies. The purpose of opening 23 is to test the quality of the reagents in forming the visually detected reaction.
[0063] Once the aggregate of antibody-antigens are formed in test region T (and a priori present in control region C), they can be detected by any manner known in the art. In a manner, they are detected by the use of antibodies against parasite antigens (for example, antibodies of the same type as those immobilized to the substrate) which are conjugated to a detectable moiety. The detectable moiety for example may be a gold particle which may be visualized directly, or alternatively, may be an enzyme such as alkaline phosphatase, which can produce a color reaction if provided with its appropriate substrate such as para-nitro phenyl phosphate. Alternatively, other enzymes or other labels may be used.
[0064] The antibody coagulated to the detectable moiety may be added, after a phase of time (allowing the parasite antibody in the tested region to react with the parasitic antigen in the stool sample) to occur, simply by adding, from an external tube, the appropriate antibody to a detectable moiety.
[0065] By another option, the antibody conjugated to the detectable moiety (either with the gold particle or with the enzyme) may be present at a different layer than the layer on which the anti-parasite antibody is present, for example, present in a layer below that of the anti-parasite antibody. Between two layers there is present a dissolvable layer, which is slowly degraded by fluids in the specimen. This ensures that there is time for degradation of the layer, allowing first the parasite antigen in the stool sample to react with the immobilized antibody and only later the antibody conjugated to the detectable moiety is added.
[0066] [0066]FIG. 2B shows essentially the same construct as FIG. 2A, but for the detection of a plurality of parasites in stool, in the present case for the detection of four different protozoa allergies marked schematically as A, B, C and D. The housing 30 has an elongated opening 31 on which the sample is poured. Then, by capillary forces the fluid advances towards the other end of the housing. Openings 32 , 34 , 36 and 38 show test results, i.e. are above the zone of the substrate containing immobilized anti-parasite antibodies. Openings 33 , 35 , 37 and 39 are control openings, i.e. in above the zones of the substrates on which are immobilized, a priori, antigen-antibody aggregates. The reaction takes place essentially as explained in 2 A above. In the present case, all the control openings have a dot indicator, indicating that the reagents properly work as they detected the a priori present antigen-antibody aggregates. In the test samples, there is an indicator in openings 32 and 36 , indicating that the tested has both parasitic protozoa A and C.
[0067] Reference is made to FIG. 3A which shows another embodiment for the housing of the invention. Housing 40 contains within substrate, such as a nitrocellulose sheet, which protrudes, in the form of a wick 41 out of the end of the housing. Then, the protruding end of the substrate may be dipped inside the vessel 43 containing the diluted stool sample. As explained above, by capillary forces, the sample advances, and through openings 44 and 45 , it can be determined whether a color reaction takes place both in the test (T) and the control (C) indicators (opening).
[0068] [0068]FIG. 3B shows a similar apparatus to that in 3 A 50 , having a protruding substrate therefrom as wick 51 . However, in this case instead of having one indicator in the form of an opening test and one indicator for control, there are four indicators for the test (T) 52 , 54 , 56 and 58 and four indicators for the control (C) 53 , 55 , 57 and 59 . After the sample has been diluted, it is poured to an elongated open vessel 60 , and the protruding substrate 51 is dipped in this liquid containing vessel. Then, the liquid advances to the zones of the antibody of the test, or the zone containing, a priori, antigen-antibody aggregates of the control, and a color reaction may be determined. In the present case, as can be seen, the controls are appropriate, and the stool sample contains both parasites A and C indicated by the presence of colored dots. | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to a drive motor mounting module for a hybrid electric vehicle, the motor mounting module in combination with the vehicle, and the method of installation into the vehicle. More specifically, the hybrid electric vehicle drive motor mounting module is comprised of a drive motor, a front motor mount support bracket, a chassis front support bracket, a chassis cross member, two rear motor mount brackets, two vertical channels, two cross braces, and two motor module locating mounts. The module can be modularly assembled prior to installation to the vehicle chassis on a main assembly line. The mounting module engages the drive motor to the chassis by three point mountings.
PRIOR ART
Series type hybrid electric vehicles are electric vehicles with an engine driven electric generator to supply electricity to the vehicle's battery and electric distribution system. Unlike parallel type hybrid electric vehicles which have a drive-line which may be driven directly from the conventional fuel burning engine as well as by an electric motor, there is no such engine to drive-line mechanical engagement in a series type hybrid electric vehicle. The term series refers to the path of energy from the engine to the drive-line and hence the power axle or axles and wheels. The generator feeds electricity to the electric system of the vehicle which includes the batteries and the drive motor. If the series type hybrid electric vehicle is not being driven, then all the electrical energy from the generator acts to charge the batteries. As a result, the drive motor needs not be mounted near or in line with either engine or generator. The drive motor may be mounted to the vehicle chassis as a completely separate step from the steps for engaging the engine and generator to the chassis. The series type hybrid vehicle lends itself to a modular motor installation. Hybrid electric vehicle technology is continuing to develop. Motor installation details and methods of assembly have not been previously described.
Since series type hybrid electric vehicles utilize an off the shelf electric motor with internal gearing, it is preferred that these off the shelf electric motors need not be significantly modified to allow installation to the chassis. The lack of mechanical engagement of the generator to the motor in the series type vehicles allows versatility in motor mounting. Three point mounting becomes a possibility.
Heretofore, a drive motor mounting module for a series type hybrid electric vehicle has not been suggested which is mounted to the vehicle through three point modular mounting without significant modification to the motor.
SUMMARY OF THE INVENTION
Accordingly, it is a primary object of the invention to provide a motor mounting module for a series type hybrid electric vehicle which allows for three point mounting to the chassis of the vehicle.
A second object of the invention is to provide a motor mounting module for a series type hybrid electric vehicle which requires no significant modification to an off-the-shelf electric motor for installation to the chassis of the vehicle. This will allow the use of various types and makes of electric motors as the vehicle's drive motor and hence lower the overall cost to produce series type hybrid electric vehicles.
The objects of the invention are satisfied with a hybrid electric vehicle drive motor mounting module comprised of an electric drive motor, a front motor mount support bracket, a chassis front support bracket, a chassis cross member, two rear motor mount brackets, two vertical channels, two cross braces, two motor module locating mounts, and two frame mount castings. The module can be modularly assembled prior to installation to the vehicle chassis on a main vehicle assembly line. The mounting module engages the drive motor to the chassis by a three point mounting arrangement.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become more apparent upon perusal of the detailed description thereof and upon inspection of the drawings in which:
FIG. 1 is a rear perspective view of a chassis of a series type hybrid electric vehicle with a motor mounting module made in accordance with this invention.
FIG. 2 is a left front perspective of the motor mounting module shown in FIG. 1 separate of the vehicle.
FIG. 3 is a left front perspective view of the support structure of the motor mounting module shown in FIG. 1 without a drive motor and separate of the vehicle.
FIG. 4 is a partial left side view of the motor mounting module shown in FIG. 1.
FIG. 5 is a partial left rear side view of the chassis mounting components separate of the motor mounting module and the vehicle shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings in greater detail, in FIGS. 1 to 5, there is shown a series type hybrid electric vehicle 101 with a drive motor mounting module 10 made in accordance with this invention. The vehicle 101 has a chassis 102 with two frame rails 103a and 103b. There is an engine 104 and an electric generator 105 engaged to the frame rails 103a and 103b. The generator 105 is electrically engaged by cables 111 to an electric control system 106 (not shown) and batteries 107 (not shown). The batteries 107 are located within a battery box 108 which is engaged to a right frame rail 103b. The electric control system 106 and batteries 107 are electrically engaged by cables 111 to an electric drive motor 11. The electric motor 11 is engaged to the frame rails 103a and 103b through the drive motor mounting module 10.
The drive motor mounting module 10 is comprised and installed to the vehicle 101 as follows. A front motor mount support bracket 12 is engaged via fasteners 81 (not shown) to the front of the electric motor 11. A chassis cross member 17 is engaged to and between the frame rails 103a and 103b with connections at a left cross member side 18 and at a right cross member side 19. The chassis cross member 17 has a centered chassis front support bracket 14. The front motor mount support bracket 12 of the motor 11 is engaged to the chassis front support bracket 14 with a rubber isolator 15 inserted between at the area of engagement. The rubber isolator 15 prevents a metal to metal contact between the front motor support bracket 12 and the chassis front support bracket 14. In the preferred embodiment, the front motor support bracket 12 is right angle or "L" shaped with a horizontal chassis cross member engagement face 12a directed forward relative to the vehicle 101. Also in the preferred embodiment, the chassis front support bracket 14 is right angle or "L" shaped with a front motor horizontal engagement face 14a directed rearward relative to the vehicle 101. This preferred embodiment allows the chassis cross member 17 to be installed to the frame rails 103a and 103b on a main assembly line. Separate from the assembly line, the front motor support bracket 12 is engaged to the motor. The motor mounting module 10 is then dropped in and engaged to the chassis 102 on the main assembly line. The front motor support bracket 12 and the chassis front support bracket 14 comprise the first or front point of the unique "3 point" motor mounting of this invention.
The second and third three points or rear points of the "3 point" mounting are comprised as follows. A right rear motor mount bracket 20 is engaged to a right rear under side of the motor 11. A left rear motor mount bracket 40 is engaged to a left rear underside of the motor 11. Separate vertical channels 21 are engaged to the right rear motor mount bracket 20 and the left rear motor mount bracket 40. A cross brace 23 is engaged between the upper portions of the vertical channels 21 for lateral support. A motor module locating casting mount 24 is engaged to each vertical channel 21. On a main vehicle assembly line, a frame mount casting 30 is engaged to the inner faces of each of the frame rails 103a and 103b of the chassis 102.
The frame mount casting 30 contains a rear isolator 32. The rear isolator 32 on each of the frame mount castings 30 is made of a rubber and acts similar to the rubber isolator 15 that was previously described on the chassis front support bracket 14. The rubber isolator 15 and the rear isolator 32 provide electro-magnetic frequency (EMF) and radio frequency interference (RFI) isolation of the motor from the rest of the chassis 102 and vehicle 101. The rear isolators 32 are shaped to engage with the motor module locating casting mount 24 which was previously attached to the vertical channels 21. The frame mounted castings 30 are engaged to the frame rail 103a and 103b through spacers 31 and fasteners 85 (not shown). The frame mount castings 30, like the chassis cross member 17, are installed to the chassis 102 on a main vehicle assembly line, while the rest of the motor mount module 10 is assembled separate from the main vehicle assembly line. The motor module locating castings 24 are shaped to fit within the frame mounting castings 30, to allow the entire rear section of the motor mount module 10 to be dropped in and installed as a modular element on the main assembly line. In the preferred embodiment, the motor module locating casting mounts 24 on the vertical channels 21 are "V" shaped so they will be aligned within the also "V" shaped frame mount castings 30 when the entire rear section of the motor mount module 10 is dropped into the chassis 102. In the embodiment of the invention shown in FIG. 2, the vertical channels 21 are each comprised of a front section 21a, a back section 21c, and a side section 21b. When viewed from above, the vertical channels 21 are "U" shaped. Also in the embodiment shown in FIG. 3, the rear motor mount brackets 20 and 40 are also made up front faces 20a and 40a, inner side faces 20b and 40b, and back faces 20c and 40c. The motor module locating casting mounts 24 are engaged to the side sections 21b of the vertical channels 21. It is the inner side sections 20b and 40b of the rear motor mount brackets 20 and 40 that are engaged to the motor 11. The inner side sections 20a and 40a are shaped to conform to the underside of the motor 11. The front sections 20a and 40a and rear sections 20c and 40c of the motor mount brackets 20 and 40 fit within the "U" shape of the vertical channels 21 where they are engaged. This embodiment may have two cross braces 23 to provide further lateral support.
The motor mount module 10 of this invention allows modular installation of the motor 11 for the motor mount module 10 on the main assembly line as follows. Separate from the main assembly line, an off-line portion of the motor mount module 10 is assembled. The front motor mount support bracket 12 is engaged to the front of the motor 11. The side sections 20b and 40b, and two rear motor mount brackets 20 and 40 are installed to the rear under side of the motor 11. The vertical channels 21 are installed to the rear motor mount brackets 20 and 40. In the preferred embodiment, the motor mount brackets 20 and 40 slip into the "U" shape of the vertical channels 21 for engagement via fasteners 86 (not shown). The cross braces 23 are installed across the upper portions between the vertical channels 21. The motor module locating casting mounts 24 are installed to the outer sides of the vertical channels 21. An on-line portion of the motor mount module 10 is assembled along the main assembly line as follows. The chassis cross member 17 is installed between frame rails 103a and 103b. The frame mount castings 30 are installed on each frame rail 103a and the 103b rearward from the chassis cross member 17. The motor 11, with the front motor support bracket 12, the rear motor mount brackets 20 and 40, vertical channels 21, cross braces 23, and motor mount locating mounts 24 installed, is lowered into place to engage to the chassis front support bracket 14 of the chassis cross member 17 and the frame mount castings 30 already installed on the frame rails 103a and 103b of the chassis 102. Fasteners 87 (not shown) are used to finally engage the motor mount module 10 to the chassis 102 of the vehicle 101. The motor mount module 10 may be installed with any off-the-shelf electric motor 11. This allows for economical decisions related to the choice of electric motor 11 for the hybrid electric vehicle 101.
The electric motor 11 is mechanically engaged to a drive or rear axle assembly 110 with rear wheels 112 through a prop shaft or drive line 113. Although described and shown as rear drive, the invention may also be applied in a front drive configuration where the drive axle assembly 110 is forward on the vehicle 101. When the motor 11 is energized and rotates, the drive line 113 rotates which imparts rotational energy to the rear wheels 112 through the rear axle assembly 110.
As described above, the drive motor mounting module of the present invention, the hybrid electric vehicle 101 with the drive motor mounting module 10 installed, and the method of installation provide a number of advantages, some of which have been described above and others of which are inherent in the invention. Also modifications may be proposed to the drive motor mounting module 10, the hybrid electric vehicle 101, and the method of installation without departing from the teachings herein. Accordingly, the scope of the invention is only to be limited as necessitated by the accompanying claims. | 4y
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CROSS REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of our co-pending appliation Ser. No. 07/780,814, filed Oct. 22, 1991, now abandoned, entitled BATTERY REPLACEMENT APPARATUS for which benefit is claimed.
BACKGROUND OF THE INVENTION
The applicable art of the present invention relates generally to devices which aid in the removal of small batteries or handling small magnetic parts and prevents contamination of the battery surfaces with the fingers. Generally, batteries which are small, on the order of 3-5 mm in diameter and 1-3 mm in height are difficult to hold and more difficult to manipulate. Manipulation is required, however, when batteries are removed from the packages in which they are sold, or when they are installed in the various devices in which they are needed. A specific situation involves one piece hearing aids which are designed to fit within the ear.
Manipulation using the prior art necessarily entails touching the battery with the fingers, thereby contaminating the surface of the battery with oil. Such contamination interferes with the electrical contact of the battery with the contact terminals of the devices in which they are installed. Another specific situation involves photographic batteries which are required to be wiped with a cloth before being inserted in photographic equipment.
There is also need for a magnetic pickup device which can be used to pick up small fasteners, such as screws, which are used to fasten common objects such as eyeglasses, to make it easier for repairmen to handle them. Such a device is of particular value in making repairs to computer hardware and electronic assemblies which require the handling of small fasteners and parts which are difficult to place or remove because they are often located in crevices or other obstructed places. An additional requirement for handling computer or electronic parts is that the handling device be small, operable with one hand and able to retrieve or place parts without subjecting adjacent components to ranging stray magnetic fields which could cause damage or loss of programmed information. No present device is known which meets all of these requirements.
The prior art battery handling devices generally consist of a rigid or slightly flexible shaft having a lint brush at one end as shown in FIG. 1. More importantly, the shaft usually incorporates a magnet rigidly mounted in the center of the shaft with the axis of the magnet held perpendicular to the axis of the shaft. The magnet is included to provide a method to attract and hold small batteries so that they may be grasped by the user.
The prior art battery handling devices are inadequate for several reasons. First, due to the geometry of the batteries involved and the nature of magnetic forces, the batteries attracted to the magnet of the prior art device contact the magnet in an undesirable orientation. The magnet generally contacts the battery on its circumference; i.e., with the axis of the battery perpendicular to the longitudinal axis of the magnet. This makes it particularly difficult to pick up the battery and insert it in a socket which grips the circumferential edge of the battery without first manipulating it with the fingers.
Manipulation of the battery when attached to the magnet is unsatisfactory because it is time consuming and difficult. Further, it is unsatisfactory because many times the user of small batteries for health aid devices, such as hearing aids, are afflicted with arthritis or have unsteady hands. The lack of dexterity in these users further complicates the task of manipulating the battery temporarily connected to the prior art device.
Second, the orientation of the magnet with respect to the shaft in the prior art device, makes the accurate placement of the battery attached to the magnet difficult. Once a battery is manually oriented on the magnet by the user, the user must then press the magnet into the socket provided by the battery-powered device. A ninety degree orientation of the magnet to the shaft makes this placement difficult.
Third, the prior art handling devices do not provide for a method of easily removing the magnet from the battery once the battery has been put in place where it is to be left. This is especially troublesome when the user is attempting to use the prior art devices to place the battery in the socket provided by the battery-powered device. After the battery has been pressed into the socket, the prior art devices have a tendency to pull the battery from the socket when removal of the prior art device is attempted.
Fourth, small battery-powered devices, such as hearing aids, generally provide a "door" or "hatch" which serves as a holder for the batteries required for its operation. Once the battery is inserted into this holder, it is rotated into the device. The battery fits snugly in the "door" of the device and is usually held in place by a friction fit between the door and the circumference of the battery. When replacement of the battery is required, the door must be dislodged from the device and rotated into its open position for removal of the old battery and insertion of the new battery. As with the manipulation of a small battery, manipulation of the "door" on a small device, such as a hearing aid, can be difficult for persons with arthritis or those who have problems manipulating their hands. The prior art devices make no provision for opening the battery doors of small devices.
Fifth, it is desirable to provide a device which allows for attachment to, manipulation of and detachment from small batteries or other parts without the necessity of handling them with the fingers. They should pick up only from the end and not the side. Physically touching a battery with the fingers often leaves a deposit of oil which can interfere with the contacts of the battery. The prior art handling devices require physical manipulation of the battery with the fingers in order to place it in the correct orientation on a freestanding magnet. They naturally are drawn to the side rather than directly under the end.
Therefore, it is desirable to provide a device which allows for easy attachment and manipulation and release of small batteries and parts without the necessity of touching them. It is desirable to provide a feature which provides for the opening of "doors" on small battery-powered devices. It is desirable to provide a magnetic pickup device which is operable with one hand and small enough to reach into small openings without subjecting other adjacent components to stray laterally extending magnetic fields. This necessitates controlling the magnetic field while using a much stronger magnet than has heretofore been commercially available.
SUMMARY OF THE INVENTION
This invention provides a simple apparatus and method for attachment to various metallic batteries. The invention further possesses the attributes of making it easy to quickly remove the battery from the packaging in which it is sold and position the battery on a magnet in a desired orientation without the requirement that the battery be handled by the user. Further, the invention provides for an easy method of detachment from the battery. Additionally, the invention provides a means to easily open battery "doors" on small battery-powered devices. Further, the invention provides a method to manipulate batteries without contamination by the fingers.
A battery replacement and pickup apparatus has an elongated barrel having an open lower end. An elongated non-magnetic shaft is movable independently within the barrel between an extended position and a retracted position and has at least a hollow lower end portion for receiving a small powerful magnet formed to fit within the hollow portion. The magnet is preferably an extremely strong powerful magnet which makes it possible to reduce the diameter of the magnet and the attendant device while still providing a strong magnetic attraction force. The magnet is fitted within the hollow lower end portion of the movable shaft for moving therewith, said magnet being generally flush with the open lower end of the barrel for magnetic connection with a small battery or other magnetically attracted part when the movable shaft is moved to the extended position. A ratchet locking means operatively disposed within the barrel alternately holds the movable shaft in the extended or retracted position and biasing means located within the barrel above the open lower end urges the movable shaft towards the retraction position whereby a small battery or other small part may be picked up and securely held by contact with the magnet when the shaft is in the extended position and released by separation of the magnet from the battery or part when the shaft is in the retracted position. The magnet is preferably a neodymium based permanent magnet which is available in compositions having an attractive force which is approximately an order of magnitude greater than common ALNICO magnets, commonly available.
The barrel is preferably a cylindrical barrel, although the barrel may have a triangular cross-section or some other shape. The lower end portion of the barrel has a cylindrical cross-section surrounding the magnet contained therein in order to provide a smaller tip which will reach into small places and not interfere with cavities in which batteries may be placed in such things as cameras.
In the variation of the invention, the lower portion of the barrel is thickened around the magnet to an extent that effectively prevents the magnet from picking up a small battery which is located at the outer side surface of the lower open end of the barrel without reducing the magnetic pickup force at the open end so that when the magnet is in the extended position it will pick up a battery only at the open end of the barrel. That is to say that when the magnet is in the extended position, the magnetic attractive force provided by the magnetic field is directed longitudinally to a much greater extent than laterally. The reduction in lateral attractive forces is accomplished both by the separation between the magnet and the object caused by the thickened lower tip of the barrel and by the inhibiting or blocking effect caused by the plastic tip of the barrel or a non-magnetic shield which surrounds the magnet. Non-magnetic as defined herein means not attracted by a magnet. Magnetic material is material means material that is attracted by a magnet.
The blocking effect is enhanced by one of several means. The battery replacement and pickup apparatus may be provided with a magnet having an outer side surface covered with a non-magnetic barrier layer which effectively blocks lateral magnetic attractive force without reducing longitudinal magnetic attraction when the movable shaft is in the extended position. The non-magnetic barrier layer is preferably bismuth, lead, or predominantly bismuth or lead alloy or material of similar magnetic blocking characteristics. The non-magnetic barrier layer in combination with the lower portion of the barrel are selected to have a magnetic blocking effect which has a lateral magnetic attraction less the weight of a small hearing aid battery so that the device will not pick up a battery from the side in the event the open end is not placed directly on the battery when the magnet is extended.
In order to provide still a smaller diameter at the tip portion of a hand held battery replacement and lower end of the magnet in the extended position, being adapted to effectively block the magnetic attractive effect at the tip in a lateral direction without also effecting the magnetic tip in a longitudinal direction. The non-magnetic shield member may be movable with the operating shaft, surrounding the lower end of the magnet or it may be fixed inside a tip opening of the barrel surrounding a portion of the operating shaft and magnet. The non-magnetic shield member is preferably constructed of lead, bismuth or predominantly lead and/or bismuth alloy or material of similar magnetic blocking characteristics.
This apparatus may also be provided with an adjustment means carried by the barrel for positioning the extended position of the magnet with respect to the lower tip opening of the barrel. The adjustment means may comprise a replaceable shim located in separable parts of the barrel which can be unscrewed and replaced to produce an extended position in which the magnet is withdrawn to a small extent into the tip opening. This is sometimes desirable for making it easier to position the tip against the upper surface of certain small button-type batteries which are constructed with a smaller diameter domed portion provided the opening is large enough to receive the upper portion of the dome inside it. In addition to a more secure hold on such a battery, it helps insure the battery is properly located on the tip end of the device. It also provides a way to reduce the magnetic attractive force at the tip itself, if desired, without changing the magnet.
In a preferred embodiment of the present invention, a two-piece elongated non-magnetic barrel is provided with is large enough to be eaily hand hold and manipulated. The barrel is preferably cylindrical though the barrel could be in the form of a polygon. The top piece of a cylindrical barrel attaches to the bottom piece of a cylindrical barrel through a threaded connection. A shim is provided between the upper and lower sections to adjust the space relationship between the upper portion of the barrel with respect to the lower portion of the barrel. The barrel is hollow and preferably has a longitudinal opening and an open tip end.
Within the cylindrical barrel, a non-magnetic shaft is provided. One end of the shaft is adapted to hold a small, cylindrical magnet. The other end is adapted to fit a "click stop" ratchet mounted in the upper end of the barrel. The "click stop" ratchet provides a means to position and lock the shaft in an extended or retracted position. Such a ratchet is found in common ballpoint pens, and is well known in the art. It extends out the upper end of the barrel for operation by the thumb of the same one hand that holds it. Other types of conventional slide mechanisms can be employed.
In the extended position of the preferred embodiment, the magnet on the end of the shaft is flush with the bottom open end of the barrel. In the retracted position, the magnet is retracted into the barrel a sufficient distance to release its magnetic hold on the object. A spring is mounted on the shaft to provide the force necessary to withdraw the magnet into the barrel. The end of the barrel is provided with a reduced diameter ledge which acts as a hook to open small doors on small battery-powered devices for battery replacement.
In operation, the "click stop" ratchet and spring are used to withdraw the magnet into the barrel of the apparatus. The barrel of the apparatus is then placed directly adjacent a flat surface of the battery. The open end in the lower barrel portion serves to align the battery with the longitudinal axis of the apparatus. The ratchet is then used to move the magnet to its extended position thereby bringing it into contact with the battery. Once in contact with the battery, the magnet is held in this position by the locking action of the ratchet.
Once in place, the ratchet is used to withdraw the magnet into the barrel weakening the magnetic field holding the battery because of the greater distance of the magnet from the battery, while retaining the battery in the desired orientation. In its retracted position, the detachment of the battery from the apparatus requires only a small additional force or it falls free of its own weight.
Once the magnet engages the battery, the apparatus may be lifted and manipulated to place the battery in its desired holder in the battery-powered device. The preferred magnet is strong enough in attractive force to withdrawn a battery against the opposing frictional forces of a battery holder such as may be found in a hearing aid. The pickup device advantageously will pick up an eyeglass screw and hold it standing up which helps to position it in its opening.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the prior art.
FIG. 2 is a perspective view of a hearing aid having an open battery compartment.
FIG. 3 is a perspective view of the hearing aid of FIG. 2, the hearing aid having the battery compartment closed.
FIG. 4 is a sectional view of the battery replacement apparatus taken along the longitudinal axis of the apparatus.
FIG. 5 is a view of the hearing aid of FIGS. 2 and 3 showing a battery held by the magnet at the end of the battery replacement apparatus ready to be inserted into the open battery compartment.
FIG. 6 is an exploded view of ratchet mechanism 53.
FIG. 7 is a perspective view of an embodiment having a triangular cross-section in the upper portion with a circular cross-section at the tip in order to minimize the diameter at the tip.
FIG. 8 is a cutaway cross-sectional view of the tip of a magnetic pickup device which is provided with a non-magnetic shield extending from the open end of the tip along the outer surface of the shaft.
FIG. 9 is an alternative version of the non-magnetic shield which is fixedly attached inside the barrel at the tip surrounding the shaft and magnet.
FIG. 10 is a schematic illustration to indicate the general kind of magnetic field that prevails at the opposite poles of a cylindrical magnet and schematically illustrates the presence of a non-magnetic barrier layer around the magnet.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 4 illustrates a sectional view of the battery replacement apparatus 10. The apparatus 10 includes a lower barrel portion 15 and an upper barrel portion 35. The lower barrel portion 15 is connected to the upper barrel portion 35 via a set of mating threads 25. Mating threads 25 on the exterior of lower barrel portion 15 fit into receiving threads 30 on the interior portion of the upper barrel portion 35. Between the lower barrel portion 15 and upper barrel portion 35, a shim 27 is provided to adjust the position of lower barrel portion 15 with respect to upper barrel portion 35.
Within upper barrel portion 35 there is a ratchet mechanism 53 which enables the extension and retraction of a magnet 65. The position of the magnet is indicated by the dotted lines in FIG. 4. Ratchet mechanism 53 is commonly found in retractable ball point pens and will only be briefly described here. A specific example is the Fisher-Price Rite Point Century pen R2013.
In FIG. 6, the three elements which make up the ratchet mechanism 53 in the preferred embodiment are best shown; the ratchet wheel 45, the ratchet driver 50 and the two pair of interprojections 40 provided on the interior of upper barrel portion 35.
Each pair of interprojections 40 is arranged to be parallel with the longitudinal axis of the apparatus and arranged to be diametrically opposed with respect to each other. The angled lower ends 42 of each interprojection form a rotational pawl. Each pair of interprojections 40 is provided with a lower ratchet stop 41. Each lower ratchet stop 41 is formed by a "stair step" between the two interprojections of each pair of interprojections 40.
The interior of barrel portion 35 is also provided with two upper ratchet stops 46. Each upper ratchet stop is placed at a ninety degree angle measured around the longitudinal axis of the apparatus from the two lower ratchet stops 41 provided between each pair of interprojections 40.
As can be seen best in FIG. 6, ratchet driver 50 is provided with an upper portion 52, lower perimeter 54 and open end 58. Around the lower perimeter 54, there is a set of eight downwardly disposed triangular teeth 56. Ratchet driver 50 is also provided with eight guide inserts 57. Each guide insert 57 is placed directly in line with the lower point of each tooth 56. Each guide insert 57 extends outwardly from the circumference of lower perimeter 54.
When the apparatus is assembled, two diametrically opposed guide inserts 57 on ratchet driver 50 are slidably mounted in both opposing pair of interprojections 40 and are constrained by interprojections 40 to reciprocate longitudinally without rotation. At least a portion of upper portion 52 of ratchet driver 50 extends out of the open end 37 of upper barrel portion 35.
FIG. 6 also shows ratchet wheel 45. Ratchet wheel 45 is provided with an upper cylindrical portion 47 and a lower ratchet portion 48. Upper cylindrical portion 47 of ratchet wheel 45 is rotatably inserted into the open end 58 of ratchet driver 50. Lower ratchet portion 48 consists of a set of eight upwardly disposed triangular teeth 49 and four upwardly disposed ratchet teeth 44 placed around its circumference. A ratchet tooth 44 is placed on every other triangular tooth 49 on lower ratchet portion 48. The diameter of the upwardly disposed triangular teeth 49 is slightly larger than that of the upper cylindrical portion 47 of ratchet wheel 45. The diameter of the ratchet teeth 44 is slightly larger than the upwardly disposed triangular teeth 49. The upwardly disposed teeth 49 of ratchet wheel 45 are designed to mate with the downwardly disposed teeth 56 on lower perimeter 54 of ratchet driver 50.
Each ratchet tooth 44 has a sawtooth slanted upper face 51 which is coplanar with one face of the upwardly disposed triangular tooth 49 on which it is placed.
Each ratchet tooth 44 is designed to slide longitudinally within the longitudinal guide formed by each pair of interprojections 40. The slanted upper face 51 of each ratchet tooth 44 is also designed to alternately engage with upper ratchet stops 46 and lower ratchet stops 41. The engagement of the slanted upper face 51 of each ratchet tooth 44 with upper ratchet stops 46 or lower ratchet stops 41 locks the ratchet wheel in a retracted or extended position respectively.
Referring again to FIG. 4, the upper end 59 of shaft 55 is adapted to fit within the lower, open end 43 of ratchet wheel 45. At the lower end 61 of shaft 55, a spring stop 60 is provided. Spring 70 is slidably arranged on shaft 55 and frictionally held in position against spring stop 60 and spring stop 17 provided on the inner surface of lower barrel portion 15. Spring 70 provides a longitudinal force to shaft 55, which translates such force to ratchet wheel 45.
The cooperation of interprojections 40, ratchet driver 50 and ratchet wheel 45 can be described as follows.
By depressing upper portion 52 of ratchet driver 50 into the open end 37 of upper barrel portion 35, the downwardly disposed triangular teeth 56 around the lower perimeter 54 of ratchet driver 50 engage the upwardly disposed triangular teeth 49 of ratchet wheel 45. As the upper portion 52 of ratchet driver 50 is depressed further within open end 37 of upper barrel portion 35, ratchet teeth 44 are pressed out of the longitudinal guide formed by the pair of interprojections 40. Once free of the longitudinal restraint of interprojections 40, the compressive force provided by spring 70 forces the teeth 49 of ratchet wheel 45 upwards into meshing engagement with teeth 56 on ratchet driver 50. The meshing action of triangular teeth 49 and triangular teeth 56 causes ratchet wheel 45 to rotate with respect to ratchet driver 50.
Upon releasing the upper portion 52 of ratchet driver 50, the compressive force of spring 70 again urges ratchet wheel 45 upward. The slanted upper face 51 of ratchet teeth 44 are forced into engagement with the slanted lower ends 42 of interprojections 40. The lower ends 42 of interprojections 40 urge ratchet teeth 44 to further rotate ratchet wheel 45.
As the upper portion 52 of ratchet driver 50 is completely released, the compressive force of spring 70 forces the ratchet teeth 44 into engagement with upper ratchet stops 46. When ratchet teeth 44 engage upper ratchet stops 46, the ratchet wheel 45 and, consequently, shaft 55 and magnet 65 come to rest in their retracted position.
Upon depressing upper portion 52 of ratchet driver 50, the cycle as described repeats, rotating ratchet wheel 45 between its retracted position and its extended position, thereby extending shaft 55 and magnet 65 alternatively as desired.
In the preferred embodiment, ratchet wheel 45, interprojections 40 and ratchet driver 50 provide a means to move and lock magnet 65 in an extended or retracted position. It is understood that many other methods of moving and locking shaft 55 in an extended or retracted position as are known in the art may be substituted for ratchet wheel 45, interprojections 40 and ratchet driver 50 within the current invention without detracting from its utility or functionality. Further methods of moving shaft 55 will not be discussed here further, but are encompassed by the present invention.
As seen in FIG. 4, shaft 55 is provided with a cavity 66 at its lower end. A magnet 65 is mounted in the cavity 66. Generally, magnet 65 is strong enough to provide a sufficient magnetic force to hold battery 95 tightly against ledge 20 when the apparatus is in its extended position, but very loosely against ledge 20 or not at all when the apparatus is in its retracted position.
In the best mode of the apparatus, magnet 65 is a small, preferably cylindrical neodymium (Nd-Fe-B) permanent magnet preferably having at least residual flux density (Br) of about 11.5 kilogauss (KGs), coercive force (Hc) of about 9 kilo oersteds (KOe), intrinsic coercive force (Hci) of about 15 kilo oersteds (KOe) and a maximum energy product (BHmax) of about 26-36 mega gauss-oersteds (MGOe).
Ideally, in the preferred embodiment, magnet 65 should be flush with opening 75 of lower barrel portion 15 when the apparatus is placed in its extended position. In order to achieve the flushness required between magnet 65 and open end 75, shim 27 is provided surrounding mating threads 25,30 and fitting between lower barrel portion 15 and upper barrel portion 35 when apparatus 10 is assembled. Shim 27 may be supplied with varying widths. The varying widths of shim 27 allow lower barrel portion 15 to be adjusted with respect to magnet 65 in order to bring magnet 65 flush with or a fixed distance from open end 75 of lower barrel portion 15. Opening 75 may be designed to accept a raised upper portion 100 of a circular battery in which case the magnet 65 may be adjusted upwardly slightly to allow the remainder of the battery to rest against ledge 20. It should be noted that certain peculiar shaped magnets may be used in the apparatus without harming its practicality or functionality. Such magnets may obviate the need for the magnet being flush with opening 75 of lower barrel portion 15.
In operation of the preferred embodiment, magnet 65 is placed in its retracted position in apparatus 10. Open end 75 of apparatus 10 is then placed directly adjacent the slightly raised portion 100 of battery 95. It should be noted that batteries not having a raised portion 100 as shown in FIG. 2 may also be held and manipulated by apparatus 10.
Ratchet driver 50 is then depressed and released locking magnet 65 into its extended position. This extended position brings magnet 65 into contact with the slightly raised portion 100 of battery 95. The attractive coercive force provided by magnet 65 attracts and holds the battery against the open end 75 of lower barrel portion 15. Once the battery is magnetically held with the battery in contact with the ledge 20 of lower barrel portion 15, the battery may be elevated and apparatus 10 may be used to place the battery into the open door 90 of hearing aid 80, a battery holding device, as indicated in FIG. 5. Once in place, magnet 65 may be withdrawn into lower barrel portion 15 by depressing and releasing ratchet driver 50, thereby locking magnet 65 into its retracted position and allowing the easy removal of magnet 65 from the battery.
In order to remove a battery from a small battery-operated device such as hearing aid 80 as illustrated in FIG. 3, it is necessary to open the door 90 which conceals the battery 95. The ledge 20 formed in the lower barrel portion 15 has a sharp edge which may be used to open door 90 in the device 80. Ledge 20 is placed directly adjacent projection 92 on door 90. Apparatus 10 may then be used to pry open door 90 exposing battery 95.
As seen in FIG. 2, once battery 95 is exposed, apparatus 10 is then positioned directly above door 90 and directly above battery 95. Open end 75 formed in the lower barrel portion 15 serves to align the device 10 with the vertical axis of battery 95. This alignment is accomplished by the slightly raised portion 100 of battery 95 fitting within open end 75 when lower barrel portion 15 is brought into contact with battery 95.
In FIG. 7 is a triangular battery replacement and pickup apparatus generally designated by the reference numeral 12. It has a generally triangular shaped barrel 16 having a triangularly shaped cross-sectional upper portion 18 and a generally circularly cross-sectioned lower section 22. It has a push button 24 of an internal ratcheting and locking mechanism which is conventionally provided to alternately move the shaft 55 with its magnet 65 into the extended or retracted position in response to depression of the push button. Shaft 55 and magnet 65 move longitudinally within the hollow barrel and in the extended position the extreme lower end of the magnet is preferably flush with opening 26 formed by wall 28 at the tip. The magnet and shaft holding it may be slightly smaller than the diameter of the tip opening 26 to avoid any possibility of small parts getting stuck between the walls and the shaft to interfere with the reciprocating motion in response to the ratchet mechanism operated by the push button.
FIG. 8 shows the cross-sectional view of the tip portion of a variation of the invention using the reference numerals of FIG. 4. This could be the tip of a shape variation of the type shown in FIG. 7. In FIG. 8 lower barrel portion 15 has an opening 75 having a lower tip end wall which will be called 28 which defines opening 75. The longitudinally extending walls 28 have an offset which creates ledge 17 on which the end of spring 70 rests. Shaft 55 is a hollow shaft in which magnet 65 is held with one of its flat ends coterminous with the lower end portion 61 of shaft 55. It is shown in the extended or pickup position.
Surrounding the cylindrical outer diameter of shaft end portion 61 within spring 70 is a cylindrical non-magnetic shield member 72 which is also coterminous with the lower end of shaft 61 and a flat surface at the end of magnet 65. Non-magnetic shield member 72 preferably extends slightly beyond the opposite end of magnet 65 as shown. It may be frictionally or otherwise attached to the outer diameter of shaft 61 to move therewith. The material for shield 72 and its thickness is adapted to effectively block the magnetic attractive effect at the tip in a lateral direction without also effecting the magnetic effect at the tip in the longitudinal direction where the arrow 75 is shown. It has surprisingly been found that lead effectively blocks the sideward effect of a magnet in attracting steel parts. It is believed that materials such as Bismuth or lead or combinations of them and alloys which are predominantly Bismuth or lead or combinations of them apparently block the magnetic flux emanating from the end of the magnet in a way that is not completely understood. It is known that bismuth, for example, is a highly diamagnetic material.
A magnetic effect is generally and schematically shown graphically in FIG. 10 insofar as it applies to the high energy (BHmax) neodymium type magnets which are preferably employed. The oval shaped areas in FIG. 10 schematically represent the magnetic field at the tip which is believed to be blocked in a sideward or lateral direction by the presence of the non-magnetic shield. The practical effect is that if the apparatus 10, 12 were placed in a vertical orientation with tip opening 75 against a horizontal surface and the magnet in the extended pickup position, a magnetic battery placed adjacent the outer side surface of barrel 15 would either not be attracted or be attracted so weakly that it would fall off under its own weight or with very little effort applied. On the contrary, if the magnet in the extended position shown in FIG. 8 were placed longitudinally directly on top of the magnetic object, such as a battery, it would be strongly attracted and held until the magnet was separated by retraction whereupon it would be released. The presence of the shield member makes it possible to use a smaller lower barrel portion 15 with a smaller diameter so that the whole device can be built about the size of an ordinary pocket clip ballpoint pen. The effect created by non-magnetic shield 72 and shield 78 in FIG. 9 is greater than that caused solely by the lateral separation of a sidewardly oriented magnetic object from the magnet which, of course, also reduces the magnetic attraction force applied.
FIG. 9 shows an alternative construction of a non-magnetic shield member 78 which in all respects is like the one shown in FIG. 8 except that shield 78 is fixed in the tip of the pen and does not move with the reciprocation of lower shaft 61 and magnet 65. It is also coterminous with the end of the tip but has an outwardly laterally angled portion which coincides with ledge 17 and extends upwardly following the inside surface 68 of barrel 15. It is larger in diameter and surrounds spring 70 which actually rests on the angled portion, supported by ledge 17.
In FIG. 10, the magnetic flux at the end corners of magnet 65 are indicated by the letter F. These lines of flux tend to be concentrated at the corner ends and not in the middle of the magnet. The preferred neodymium type magnets which have great attractive force tend to have this pattern. Even though the magnetic flux is believed to be blocked by the magnetic shield so as to extend only longitudinally with respect to magnet 65 and not laterally, the exact shape and extent of these flux lines is not actually understood, but the effect is as though they were blocked by the shield member. That is to say that with the construction of FIGS. 8 or 9, without the shield member, the tip would attract magnetic parts at the side of the tip and with the non-magnetic shield it will not or will attract so weakly as to not cause problems with errant pickup which necessitates hand manipulation to get the part back around to opening 75 so that it can be properly manipulated.
FIG. 10 also illustrates the use of a barrier coating layer 82 which surrounds side wall 76 of magnet 65. This can also serve as a non-magnetic shield member and can be supplied as a layer of solder on the outside of the magnet taking care to not overheat the magnet such that its coercive force would be reduced. Barrier layer 82 might also be provided by wrapping the outer surface of the magnet to build up sufficient thickness always leaving at least the terminal lower end of magnet 65 open so that the magnet picks up at the open end. Barrier layer 82 can be a substitute for non-magnetic shield members 72, 78 or they can be used in combination or in combination with a thickened tip to eliminate any stray laterally extending magnetic field that would permit errant pickup from the sides. Any combination of a thickened plastic barrel 15, a non-magnetic barrier coating 82 or shield 72, 78 is within the scope of the invention. They should be selected to optimize the minimal side pickup propensity.
In the best mode, some dimensions of a typical battery pickup device without the non-magnetic shield member may be helpful to understand the invention. Shaft member 55, 61 is a thin brass tube having an inside diameter 71 of about 0.105" which is also approximately the outside diameter 76 of magnet 65. The outside diameter of the shaft tube was about 0.122". The magnet was fixed inside the open end of the tube with suitable adhesive. The magnets are commonly made by powder metallurgy techniques and can be provided to a small tolerance in diameter variation. The outside diameter of the ABS plastic lower barrel portion 15 was 0.250" in one example which utilized a HENNEO 35 magnet to make a battery pickup device. It exhibited some undersirable pickup propensity from the side. It is estimated that a thickening of the lower barrel tip to about 0.300" would be required to reduce the side pickup propensity of this structure to an acceptable degree. This was compared by putting a donut-shaped plastic part around the tip of the barrel which reduced the sideways pickup propensity. Some experimentation may be necessary to select the best materials for blocking the sideward magnetic pulling effect of the magnet. It is believed that better materials for this purpose are materials such as bismuth and lead as compared to air. Plastic such as ABS plastic is not as effective for this purpose but also exhibits a blocking effect which is believed to be related to density of the plastic, with greater density being helpful in this regard. Materials such as aluminum or copper are believed to have very little, if any, effect in reducing the sideward magnetic pulling effect when interposed between a magnet and a magnetically attractable part.
A lead shield which significantly reduced the side attraction was placed all around the side surface of the magnet and estimated to have a thickness of about 0.050-0.100" in a test. This had the effect of substantially weakening the magnetic field of the side direction without having any effect on the attractive pull at the tip. It did not completely eliminate the side attraction but weakens the side pickup propensity of attractive pull from the side to an acceptable amount. A thicker shield would be expected to have a greater weakening effect. Use of the shield should make a smaller tip diameter possible without increasing undesirable side directed attractive forces.
The magnets are obtained from Hennaco Industrial Enterprises, Inc., 5 Highview Court, Montville, N.J. 07045, U.S.A. A copy of the magnet supplier's chart entitled "Magnetic and Physical Characteristics of HENNECO (Nd-Fe-B)" is attached hereto and incorporated by reference. These magnets are sold under the trade name Henneo, and those referred to a Henneo 30 or Henneo 35 are believed to make good magnets for this application with the HENNEO 35H being most desirable because it has enough magnetic attraction force to pull small hearing aid batteries out of the retaining socket even when they are tightly frictionally held therein. An intrinsic coercive force of about 15 KOe or greater is preferred in order to have sufficient magnetic strength for this purpose. Where this is not such a problem an intrinsic coercive force of about 9 KOe would be suitable. These magnets provide an extremely powerful attractive force in an extremely small package. It doesn't matter which pole of the magnet is used at the top, but it is important that the face on the end of the magnet be perpendicular to the long axis within a very close tolerance of about ±0.002 inches because otherwise there is created a non-uniform magnetic field that exaggerates the undesirable side attraction. A non-uniform field may also be created if the magnets are not properly aligned when they are magnetized initially.
It should be noted that the shield surrounding the magnet must not be made of magnetic material (magnetizable) such as steel, because it traps the magnetic field in a way that results in undesirable magnetic side attraction at the tip even when the magnet is retracted. It seems that if steel were used as the shield the magnetic effect is transferred to the shield all up and down the length of the ferromagnetic steel shield even when the magnet is in the retracted position. | 4y
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This is a continuation of application Ser. No. 167,006, filed Mar. 10, 1988, now abandoned.
FIELD OF THE INVENTION
The present invention relates to the art of constricting objects using a clamp and a flexible band and, in particular, to a clamp unit which can be removed from a band and subsequently positioned on the band at a different location.
BACKGROUND OF THE INVENTION
There are a number of prior art clamping devices of different configurations and for use in achieving a variety of clamping purposes. According to one method of categorization, these devices can be classified into one of two categories. The first category is characterized by the fact that one end of the band is, by design, permanently fixed to the clamp housing. If not so attached at manufacture then it is essentially permanently attached upon initial assembly by the user of the clamping device. The second category consists of those clamping devices in which the clamp or housing thereof can be removed from the band or strap and re-positioned on the band at a different location or attachment area.
With respect to this second category of clamping devices, prior art devices are disclosed in three known prior art patents. U.S. Pat. No. 3,879,811, issued Apr. 29, 1975, to Leverton, entitled "Constrictible Band Clips" describes a band with circular holes in it and a housing with a single tooth or protuberance to engage the band at a desired or selected one of the holes. The other end of the band is bent at a right angle and is rotatably attached to the nose of an adjuster screw. Turning of the screw moves the screw through the housing and decreases the length or diameter of the band around an object, which is being constricted by the band. U.S. Pat. No. 4,286,361, issued Sept. 1, 1981, to MacKenzie, entitled "Hose Clamp" describes a band with slot holes in it and a housing with protuberances extending from its lower outer surface to engage the band at a selected first area or point. The band is engaged at a second area or point by means of a worm-drive screw. Guide arms at one end of the housing locate and position the protuberances in the holes of the band, together with the object being constrained. U.S. Pat. No. 4,307,495, issued Dec. 29, 1981, to Sadler, entitled "Hose Clamp" describes a band with slot holes in it and a housing with protuberances extending from its lower inner surface to engage the band at one point. The band is engaged at a second point by a worm-drive screw.
SUMMARY OF THE INVENTION
The clamping assembly of this invention preferably includes a flexible roll formed band which has a continuous, alternating series of depressions and ridges along its longitudinal axis. The clamping assembly also includes a clamp unit and a worm screw. The clamp unit is used to engage the band at one suitable position on the band. The worm screw is received into a chamber of the clamp unit for engaging a second suitable position.
The clamp unit includes a body having a generally semi-circular shape. The clamp unit also includes an interior shelf connected to one side of the body and an exterior shelf connected to the opposite side of the body. Because of this construction, a band receiving area or longitudinal gap is defined between the shelves into which band portions can be inserted laterally. The depressions and ridges of the band are engaged by locking teeth extending out from the interior shelf. These teeth prevent movement of the band in longitudinal direction. Also because of the teeth construction and arrangement, the band cannot be inserted into the clamping unit in a longitudinal direction. The second location on the band is engaged by the worm screw and band portions are held firmly against an outer surface of the interior shelf.
In use, in one embodiment, one end of the band is inserted into the clamp unit in a direction along the longitudinal extent of the band. The screw is then positioned into the clamp unit. Next, the band is placed around the object to be confined. Portions of the band are then slid sideways into the clamp unit using the longitudinal receiving area so that the band closely confines the object. The screw can be used to further tighten the band around the object, if needed or desired.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevational view showing the various parts of the clamping assembly of the present invention joined together;
FIG. 2 is a longitudinal, cross-sectional view illustrating the engagement between the worm screw and band portions, as well as the engagement of the locking teeth and other band portions;
FIG. 3 is a lateral, cross-sectional view illustrating the assembled parts of the clamping assembly including the locking teeth that engage portions of the band;
FIG. 4 is a perspective view showing the clamp unit with the worm screw and band portions removed;
FIG. 5 is a cross-sectional view showing the band portions and the locking teeth with the worm screw removed;
FIG. 6 is a cross-sectional view showing the clamp unit with the worm screw and the band portions removed; and
FIG. 7 is a perspective view illustrating the sidewise connecting of the clamp unit and band portions.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with the present invention, a clamping assembly 10 is disclosed for use in tightening objects, such as hoses and the like. With reference to FIG. 1, the clamping assembly 10 includes a clamp unit or housing 12 that receives portions of a band or strap 14. The band 14 is positioned about the object to be clamped or tightened. The clamp assembly 10 also includes a worm screw 16, which is positioned and held in the clamp unit 12 for use in adjusting the tension of the band 14 by movement thereof relative to the clamp unit 12 by turning or rotating the worm screw 16.
The band 14 is, preferably, a roll formed band. With reference to FIGS. 2-4, the roll formed band 14 includes a number of alternately spaced ridges 17 and depressions 18. The depressions 18 define recesses for receiving threads 20 of the worm screw 16, but are not so deep as to constitute through holes in the band 14.
The important and novel features of the present invention reside in the clamp unit 12, as best illustrated in FIGS. 4 and 6, which show the clamp unit 12 without the roll formed band 14 and the worm screw 16. The clamp unit 12 includes a main body 22, which is shaped somewhat in the form of a semi-circle. One end of the body 22 is open for inserting the screw 16 while the opposite end has a stop wall or cover 24 against which is positioned the tip of the screw 16, as best seen in FIG. 2 The clamp unit 12 also includes an interior shelf 26 having a portion or side integrally formed with the body 24. The body 22 and the interior shelf 26 define a chamber 28 for receiving the threads 20 of the worm screw 16 and portions of the band 14. The interior shelf 26 extends inwardly of the body 22 to define the chamber 28 and terminates to define a free end or edge 30 of the interior shelf 26. The interior shelf 26 also includes a first or upper surface 32 and a second or lower surface 34. The upper surface 32 faces the chamber 28 and the lower surface 34 has a number of teeth or projections 38 that extend outwardly from the lower surface 34. The teeth 38 are spaced from each other to define recesses 40, as seen in FIGS. 2 and 5. The recesses 40 are of a size to receive ridges 17 of the roll formed band 14 for use in providing a locking engagement between the clamp unit 12 and the roll formed band 14.
The clamp unit 12 also includes a leg 44 connected to that side of the body 22 opposite from the side integrally joined to the interior shelf 26. The leg 44 extends a short distance and is integrally joined to an exterior shelf 46. As can be seen in FIG. 6, the free edge 30 of the interior shelf 26 and the leg create a longitudinal gap having a relatively small width. The exterior shelf 46, like the interior shelf 26, has a first or inner surface 48 and a second or outer surface 50. The inner surface 48 faces the locking teeth 38 and provides a support for portions of the band 14. The inner surface 48 has a substantially relatively smooth face. The outer surface 50 also has a substantially relatively smooth face and is that part of the clamp unit 12 that contacts portions of the object to be held or clamped by the clamping assembly 10. The exterior shelf 46 is an integral solid or continuous member that has a longitudinal extent essentially the same as that of the interior shelf 26. The lateral extent or width of the exterior shelf 46 is greater than that of the interior shelf 26. The exterior shelf 46 also has a free edge 54, which is located near or below that edge of the interior shelf 26, which is integrally joined to the body 22. This construction defines a longitudinally-extending gap or receiving area 56 for use in receiving a selected or desired portion of the roll formed band 14. Unlike known clamping assemblies, the clamp unit 12 and band 14 of the present invention are combined or joined together by using a sidewise movement of one or both of the clamp unit 12 and the band 14, as will next be explained.
In using the clamping assembly 10, a desired length of the roll formed band 14 is selected and typically cut or disconnected from a larger roll of the band 14. With reference to FIG. 7, a desired or selected band portion or attachment area on the band 14, which is spaced from first and second free ends 58, 60 of the band 14, is taken and inserted into the longitudinally extending receiving area 56 in a sidewise manner. The clamp unit 12 is joined to this portion of the band 14 by moving the clamp unit 12 substantially perpendicular to the longitudinal extent of the band 14. In this manner, the locking teeth 38 are caused to engage the depressions 18 of this part of the band 14. The teeth 38 are configured to function with the ridges 17 and the depressions 18 of the band 14 such that the teeth 38 will not accept the band in a direction along the longitudinal extent of the band 14. That is, the user is unable to position the free ends 58, 60 of the band 14 between the interior and exterior shelves 26, 46, respectively, in a direction along the longitudinal extent of the band 14. After the clamp unit 12 and the band 14 are joined together, the next step is to position the band 14 about the object to be constrained. After being positioned about the desired object, the free end 60 of the band 14 is inserted into that end of the clamp unit 12 having the stop wall 24 so that the free end 60 is supported on the first or upper surface 32 of the interior shelf 26 and with the ridges 17 and the depressions 18 of the band 14 facing the chamber 28. The user pushes or causes a portion or length of the band 14 through the clamp unit 12 so that the band 14 is more closely in contact or adjacent to the object. The threaded portion 20 of the worm screw 16 is then inserted into the chamber 28 whereby the threaded portion 20 overlies portions of the roll formed band 14 and the threads 20 are received by the depressions 18 of the band portion supported on the upper surface 32 of the interior shelf 26. The worm screw 16, which has its tip or end abutted against the stop wall 24 can then be turned to cause the band 14 to move relative to the clamp unit 12 and thereby further tighten the band 14 about the object.
Based on the foregoing detailed description, a number of advantages of the present invention are readily seen. A clamping assembly is provided that can be easily adapted to clamp different sized or diameter objects since the clamp unit is detachable from the band. The clamp unit and the band are readily attached using a novel sidewise engagement whereby locking teeth of the clamp unit engage depressions of a roll formed band. A worm screw received by the clamp unit provides the fine adjustment or tightening of the band about the object. The clamp unit is an integral piece that can be inexpensively manufactured and yet provides the necessary strength and locking capability to reliably clamp hoses or other objects.
Although the present invention has been described with reference to a particular embodiment, it should be appreciated that variations and modifications can be effected within the spirit and scope of this invention. | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Patent Application No. 60/550,972, filed Mar. 5, 2004 and Application Ser. No. 60/577,405, filed Jun. 4, 2004. The contents of these applications are incorporated herein by reference.
STATEMENT ON FEDERALLY SPONSORED RESEARCH
N/A
Embodiments of the present invention are directed to devices and method for coupling, or joining components for receiving and discharging fluids. Devices made in accordance with the present invention have special application to fittings, valves and check valves.
BACKGROUND OF THE INVENTION
The present invention is directed to devices for receiving and discharging fluids. Devices embodying features of the present invention include, by way of example, without limitation, tees, unions, fittings, valves and check valves. These devices are sometimes placed in line between two or more conduits that are joined in the form of a union, or tee, or valve. The term “union” is used in the sense of joining or bringing together. A “tee” is a form of fitting in which fluid flow is split or combined. The devices are sometimes part of a larger structure in which the device communicates through ports or openings. This application will use the term “fluid path means” to mean all conduits, tubing, pipes, openings or ports which convey or transport fluids.
In this application, the term fitting will be used in the broadest sense to refer to a device that may be placed in a larger structure, for example, a pump assembly, or in line.
The term “valve” is used in a conventional manner to denote a device that can stop fluid flow in a conduit or pipe. A check valve is a special valve that allows fluid to flow in one direction only.
Fitting and valves of the prior art typically have gaskets and seals that are separate and discrete parts. These gaskets and seals exhibit material creep, cold flow and relaxation. That is, as the fluid pressure fluctuates, the gaskets move. This movement can lead to the gasket slipping from an original position, leading to gasket or seal failure.
This movement also creates a rebound of the gasket as the pressure is released, creating a potential pressure ripple. Analytical instruments, in particular, are sensitive to the rebound and pressure ripple effect.
These problems are amplified as the pressure contained by such devices increases. Analytical instruments, such as chromatography pumps and detectors typically operate at pressures of up to 3,000 to 4,000 pounds per square inch (psi). It is desirable to have analytical instruments operate at higher pressures, however, fittings, valves and check valves have a high failure rate at pressures greater than 3,000 psi.
SUMMARY OF THE INVENTION
Embodiments of the present invention feature devices and methods for holding fluids at high pressures. One embodiment of the present invention features a device for receiving and discharging fluids. The device comprises a first housing having at least one side wall. The side wall has an interior surface defining at least one chamber and has at least one end cap abutment surface for receiving an end cap. The device has at least one end cap having at least one first housing abutment surface. The first housing abutment surface receives the end cap abutment surface positioning the end cap on the first housing for enclosing the chamber. At least one of the first housing abutment surface and the end cap abutment surface has first seal coating. The first seal coating comprises a deformable plastic adhering to the abutment surface. The device further comprises a fluid path means for receiving and removing fluid from the chamber. And, the device comprises compression means to compress the end cap, with the end cap abutment surface received on said first housing abutment surface, towards said first housing to deform said first seal coating and seal said chamber.
Preferably, the seal coating is selected from one or more of the polymeric coatings consisting of polytrifluoroethylene (PTFE), polyetheretherketone (PEEK), polychlorotrifluoroethylene (PCTFE), perfluoroalkoxy (PFA) and fluorinatedethylenepropylene (FEP).
As used herein, the term “fluid path means” refers to openings, ports, conduits and pipes that provide fluid. Thus, embodiments of the present invention can be placed in line, with fluid path means comprising conduits and pipes or incorporated within the housing of a larger structure, for example, without limitation, a pump head or pump housing.
Preferably, the end cap abutment surface and/or the housing abutment surface is a ridge to localize compression forces on said seal coating. The ridge is a relatively narrow protrusion capable of contact with an opposing abutment surface.
Embodiments of the present invention are ideally suited for fittings and valves. Where the device is in the form of a valve, the chamber contains a valve assembly. The valve assembly may comprise rotary-type valves, gated valves or check valves.
In the case where the device is in the form of a check valve, the first housing has at least one end wall opposite the end cap. The fluid path means comprises at least one opening in said end cap and at least one opening in said end wall. And, the chamber holds a valve assembly comprises a ball seat and a ball.
Preferably, the interior wall and/or the end cap has a ball seat abutment surface. And, the ball seat comprises a cylinder having a two rims, and a fluid passage. At least one of the rims has a ball receiving surface for engaging the ball and closing the fluid passage. And, at least one of the rims has a rim abutment surface for engaging the ball seat abutment surface and sealing the ball seat and the housing and/or end cap.
Preferably, the ball seat abutment surface and/or rim abutment surface has a ball seat seal coating. Preferably, the ball seat coating is made and formed as described above with respect to the seal coating.
Preferably the first housing end wall has an interior surface and an exterior surface, and one or more end wall openings. And, the exterior surface has an end wall abutment surface encircling the one or more end wall openings. Preferably, the end wall abutment surface has an end wall seal coating, the end wall seal coating comprising a deformable plastic to sealably engage an adjoining wall. Preferably, the end wall seal coating is made and formed as described above with respect to the seal coating. Devices of this type are well suited to be mounted in a further major housing structure having the adjoining wall. For example, without limitation, the end wall seal coating would engage the adjoining wall of a pump head housing. In this embodiment, preferably, the adjoining wall has an adjoining wall opening for the passage of fluid into the end wall opening. In this embodiment, the compression means comprises such adjoining wall for receiving the end wall and compressing the end wall seal coating in sealing engagement.
For inline application, preferably, the compression means comprises a compression housing assembly comprising a compression housing and compression sleeve. The compression housing has a compression chamber for receiving the housing. The compression sleeve engages the end cap for placing the end cap, and first housing under compression.
Preferably, the compression housing assembly has a compression nut. The compression nut and compression housing have cooperating threads which engage upon relative rotation of the compression nut and compression housing. The compression nut engage the compression sleeve to compress the compression sleeve, end cap and first housing within the compression housing chamber.
A further embodiment of the present invention comprises a method of joining fluid passages. One embodiment of the present method comprises the steps of providing a device having a first housing having a at least one side wall. The side wall has an interior surface defining at least one chamber, and has at least one end cap abutment surface for receiving an end cap. The device has at least one end cap. The end cap has at least one first housing abutment surface and is capable of being received on the first housing abutment surface for enclosing said chamber. The device has a first seal coating on at least one of the first housing abutment surface and the end cap abutment surface. The first seal coating comprises a deformable plastic adhering to the abutment surface. The device has a fluid path means for receiving and removing fluid from the chamber; and compression means to compress the end cap, with said end cap abutment surface received on said first housing abutment surface, towards said first housing to deform said first seal coating and seal said chamber. The method further comprises the step of placing the receiving conduit and discharge conduits in communication with the fluid passages.
Embodiments of the present method can be practiced with any of the devices of the present invention described above. The devices and methods of the present invention are ideally suited for high pressure applications. These high pressure applications include pressures of 4000 psi and greater.
The devices made in accordance of the present invention do not have seals that exhibit material creep, cold flow and relaxation. That is, as the fluid pressure fluctuates, the seal coating do not move. The seal coatings are adhered to or fixed to one of the abutment surfaces. As such the seal coating can not move or slip from an original position. Thus, embodiments of the present invention provide devices that do not have gasket failure.
Nor do devices of the present invention exhibit rebound pressure ripple due to gasket movement as the pressure is released. Analytical instruments, in particular, having devices made in accordance with the present invention are less sensitive to pressure fluctuations. These features and advantages will be apparent to those skilled in the art to which this invention relates upon viewing the Figures and reading the detailed description that follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts, in cross section, a side view of a device made in accordance with the present invention;
FIG. 2 depicts, in slight elevation, a view of an end cap of a device made in accordance with the present invention;
FIG. 3 depicts, in slight elevation a view of an end cap of a device made in accordance with the present invention;
FIG. 4 depicts, in cross section, a side view of an end cap of a device made in accordance with the present invention; and,
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will now be described with respect to the Figures, with the understanding that the Figures and description are directed to the preferred embodiments of the present invention. For example, the present invention will be described in detail with respect to a check valve. Individuals skilled in the art will recognize that features of the present invention have application in many devices which hold or transport fluids under pressure.
Turning now to FIG. 1 , a device, for holding fluids at high pressures, generally designated by the numeral 11 , is depicted. The device 11 , for receiving and discharging fluids, is in the nature of a check valve. Device 11 comprises a first housing 13 , an end cap 15 , at least one seal coating 17 and compression means 19 .
Turning now to FIG. 2 , the first housing 13 has at least one side wall 25 . Side wall 25 has an interior surface 27 a and an exterior surface 27 b . The interior surface 27 a defines at least one chamber 29 , preferably, cylindrical in shape. Interior surface 27 a has at least one end cap abutment surface 31 for receiving the end cap 15 . Preferably, the end cap abutment surface 31 is recessed into chamber 29 to facilitate positioning of the end cap 15 . As depicted, interior surface 27 has a recess section 33 forming the recess for receiving end cap 15 .
The housing 13 has an end wall 35 having an interior surface 37 a and an exterior surface 37 b . The end wall 35 closes the chamber 29 defined by the interior surface 27 a of the side wall 25 .
End cap 15 is cylindrical in shape to cooperate with the recess section 33 of the interior surface 27 a of the first housing 13 . End cap 15 has at least one first housing abutment surface 39 . Turning now to FIGS. 3 and 4 , alternative embodiments of end cap 15 are disclosed. The end cap 15 of FIG. 2 is illustrated in greater detail in FIG. 3 . End cap abutment surface 39 is a ridge 39 a to localize compression forces on said seal coating 17 . The ridge 39 a is a protrusion jutting upward from a planar surface 39 b . The ridge 39 a is capable of contact with an opposing abutment surface such as end cap abutment surface 31 of the first housing 13 . The ridge 39 a localizes or focuses compression forces in a small area.
Turning now to FIG. 4 , a further embodiment of the end cap 15 is illustrated, generally designated by the numeral 15 ′. End cap 15 ′ is cylindrical in shape to cooperate with the recess section 33 of the interior surface 27 a of the first housing 13 . End cap 15 ′ has at least one first housing abutment surface 39 ′. In this embodiment, the first housing abutment surface 39 ′ is planar, without any protruding surface features. The abutment surface 39 ′ is capable of contact with an opposing abutment surface such as end cap abutment surface 31 of first housing 13 .
The first housing abutment surface 31 receives the end cap abutment surface 39 and 39 ″ positioning the end cap 15 and/or 15 ′ on the first housing 13 for enclosing the chamber 29 . The end cap 15 and/or 15 ′ and first housing are typically made of stainless steel; however, other materials can readily be substituted. In the case where, the first housing 13 and end cap 15 and/or 15 ′ are parts of a check valve, the first housing 13 is approximately 0.25 to 0.75 mm in length and diameter. The end cap 15 and or 15 ′ are approximately 0.1 to 0.70 in diameter and 0.1 to 0.2 mm in thickness.
At least one of the first housing abutment surface 39 and/or 39 ′ and the end cap abutment surface 31 has first seal coating 17 . The first seal coating 17 comprises a deformable plastic adhering to first housing abutment surface 31 and/or 31 ′ or the end cap abutment surface 39 . Seal coating 17 is selected from one or more of the polymeric coatings consisting of polytrifluoroethylene (PTFE), polyetheretherketone (PEEK), polychlorotrifluoroethylene (PCTFE), perfluoroalkoxy (PFA) and fluorinatedethylenepropylene (FEP). The polymeric coating is applied to the entire end cap 15 and/or 15 ′ or the first housing abutment surface 31 and/or 31 ′ to a thickness of 0.0005-0.0025 inches, and most preferably, approximately 0.0010 to 0.0015 inches. Methods of placing a polymeric coating on a metal substrate are well known in the art.
The device 11 further comprises fluid path means for receiving and removing fluid from the chamber. Referring now to FIGS. 3 and 4 , the end cap 15 and 15 ′ have an end cap opening 45 . And, returning now to FIG. 1 , the first housing has a first housing opening or more preferably a pair of first housing openings 47 a and 47 b for introducing fluids into the chamber 29 . Preferably, the pair of openings are set off axis for check valve applications in end wall 35 .
The end cap opening 45 and first housing openings 47 a and 47 b may comprise any ports, conduits and pipes that provide fluid. Thus, embodiments of the present invention can be placed inline, with fluid path means comprising conduits and pipes or incorporated within the housing of a larger structure, for example, without limitation, as depicted in FIG. 1 , a pump head or pump housing 49 .
The device 11 comprises compression means 19 to compress the end cap 15 and/or 15 ′, with the end cap abutment surface 31 and/or 31 ′ received on said first housing abutment surface 39 , towards said first housing 13 . The compression deforms the first seal coating 17 and seals the chamber. As illustrated in FIG. 1 , the compression means 19 comprises pump housing 49 , compression housing 51 and screw fitting 53 .
It will be recognized by those skilled in the art that pump housing 49 may be substituted with a further fitting that cooperates with compression housing 51 and screw fitting 53 , to allow the device 11 to be placed in a fluid line.
Embodiments of the present invention are ideally suited for fittings and valves. Where the device is in the form of a valve, referring to FIG. 2 , the chamber 29 contains a valve assembly 61 . The valve assembly 61 may comprise rotary-type valves (not shown), gated valves (not shown) or check valves, to described in further detail.
In the case where the device is in the form of a check valve, the first housing 13 has at least one end wall 65 opposite the end cap 15 or 15 ′. The fluid path means comprises at least one opening 45 in said end cap 15 or 15 ′ and at least one opening, and preferably two, 47 a and 47 b , in said end wall 65 . Chamber 29 holds a valve assembly 61 comprising a ball seat 71 and a ball 73 .
Preferably, the interior wall 27 a has a first ball seat abutment surface 77 . And, the end cap 15 and/or 15 ′ has a ball seat abutment surface 79 . The ball seat 71 comprises a cylinder section 81 having a first rim 83 , a second rim 85 and a fluid passage 87 . The first rim 83 has a ball receiving surface 89 for engaging the ball 73 and closing the fluid passage 87 . Second rim 85 has a rim abutment surface 91 and end cap 15 and/or 15 ′ has a ball seat abutment surface 79 . Preferably, at least one of the rim abutment surface 91 and ball seat abutment surface 79 has a ball seat seal coating 95 . The ball seat seal coating 95 engages the abutment surface opposite to that it is placed and seals the ball seat and the housing 13 and/or end cap 15 and/or 15 ′. The ball seat coating 95 may comprise a portion of the seal coating 17 on the end cap 15 and/or 15 ′. Preferably, the ball seat coating is made and formed as described above with respect to the seal coating 17 .
The exterior surface 37 b of end wall 35 has an end wall abutment surface 99 encircling the one or more end wall openings 47 a and 47 b . Preferably, the end wall abutment surface 99 has an end wall seal coating 101 . The end wall seal coating 101 is a deformable plastic made and formed as described above with respect to the seal coating 17 . The end wall seal coating 101 sealably engages an adjoining wall to which it is compressed.
Devices of this type are well suited to be mounted in a further major housing structure having the adjoining wall. For example, turning now to FIG. 1 , the end wall seal coating 101 engages the adjoining wall 105 of a pump head housing 49 . In this embodiment, preferably, the adjoining wall 105 has an opening 103 for the passage of fluid into the end wall opening (not shown). In this embodiment, the compression means 19 comprises such adjoining wall 105 and a cylindrical wall 107 for receiving the end wall abutment surface 99 and compressing the end wall seal coating 101 in sealing engagement. The compression means 19 comprises a compression assembly comprising a compression housing 51 and compression sleeve 53 . The compression housing 51 has a compression chamber 113 for receiving the first housing 13 and the end cap 15 and/or 15 ′. The compression sleeve 53 engages the compression housing 51 for placing said end cap 15 and/or 15 ′, and first housing 13 under compression.
Preferably, the compression sleeve 53 and compression nut (not shown) or the pump head 49 or other apparatus to which it is placed has cooperating threads 115 as depicted in FIG. 1 . The cooperating threads 115 engage upon relative rotation of the compression sleeve and pump housing 49 or compression nut (not shown).
Turning now to FIG. 2 , the compression housing 51 has an second end cap abutment surface 117 . At least one of the end cap 15 and/or 15 ′ has a compression assembly seal coating 121 . The compression assembly seal coating 121 is a deformable plastic made and formed as described above with respect to the seal coating 17 . The compression assembly seal coating 121 sealably engages an adjoining wall to which it is compressed.
In operation, a method of using the present invention to joining fluid passages comprises the steps of providing a device 11 having a first housing 13 , an end cap 15 and or 15 ′, a seal coating 17 and compression means 19 . The device has a fluid path means for receiving and removing fluid from the chamber 29 . The method further comprises the step of placing the receiving conduit and discharge conduits in communication with the fluid passages and compressing the seal coating 17 to seal the chamber 29 .
The devices and methods of the present invention are ideally suited for high pressure applications. The devices made in accordance of the present invention do not have seals that exhibit material creep, cold flow and relaxation. That is, as the fluid pressure fluctuates, the seal coating do not move. The seal coatings are adhered to or fixed to one of the abutment surfaces. As such the seal coasting can not move or slip from an original position. Thus, embodiments of the present invention provide devices which do not have gasket failure.
These and other advantages and features will be apparent to those skilled in the art to which this invention relates and therefore the present invention should not be limited to the precise details disclosed herein but should encompass the subject matter of the claims that follow. | 4y
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FIELD OF THE INVENTION
The invention concerns a frame for machine tools of the type comprising a horizontal bed and at least one vertical upright. In the present invention there is provided a rigid wall rigidly connected with the bed and the upright for bracing and stiffening. The bed, the upright and the wall are preferably cast as a single piece, preferably of a polymerizable resin-concrete.
BACKGROUND OF THE INVENTION
A large class of machine tools are disposed on a frame which includes a horizontal bed and at least one vertical upright which is mounted on the bed. Depending on the particular construction of the machine tools there are provided on the vertical uprights and on the bed clamping means, and drive means for workpiece and tools, and these are disposed in operable association over three or more axis.
It is known to produce the frame from cast iron or cast steel. The production of these frames is inefficient, since after the casting a further operation such as milling or grinding is necessary. In particular because of this secondary operation it becomes impossible, as a rule, to cast frames for large machine tools in a single casting. A further substantial assembly operation expense is therefor necessary in order to join together these individual pieces.
It is further known to produce a frame of sintered steel. Here also substantial production and assembly expenditures are necessary.
Finally, it is known (for example, see EP 0 046 272 A2), to cast the frame in a single piece using a castable concrete comprising mineral particles bound by a setting polymer resin. This method of manufacture is economical. These frames are characterized by a substantially higher vibration dampening characteristic as compared with the above-mentioned frames constructed of cast iron, cast steel and sintered steel.
It is a common feature of all these known frames, that the uprights which are mounted on the frame project tower-like clear from the bed. Higher loads, inaccuracies in the calibrated assembly of the bed, temperature fluctuations and temperature gradients can therefor result in bending and torsional movement of the upright with respect to the bed. Such movements directly compromise the targeted machine tool precision. In order to improve the precision and minimize the deformation movement of the stand and the bed, the dimensions and the cross-sections of the frame are enlarged. A small improvement in precision is attained at the expense of a substantial increase in the weight and in the material cost of the frame.
The present invention is concerned with the problem of providing a frame for machine tools, which with less expenditure makes possible a higher degree of mechanical precision of the machine tools.
SUMMARY OF THE INVENTION
This problem is solved in accordance with the invention by providing, in a frame for machine tools of the type comprising a horizontal bed and at least one vertical upright, a rigid wall rigidly connected with the bed and the upright for bracing and stiffening. The bed, the upright and the wall are preferably cast as a single piece, preferably of a polymerizable resin-concrete.
Preferred embodiments of the invention are set forth in the dependent claims.
In the frame according to the invention, there is provided, in addition to the horizontal bed and the vertical upright, a vertical rigid wall, which is rigidly fastened on the one hand with the bed and on the other hand with the upright. This wall brings about a form stable bracing of upright and bed, which stiffens the frame against bending and torsion. The bracing by means of the wall makes the frame into a unit having form stability against bending and twisting. Inaccuracies in the alignment during the assembly of the frame have practically no consequence on the precision of the respective positioning of the bed and upright. Fluctuations in the room temperature and in particular temperature gradients in the vicinity of the frame have less of an effect on the form stability of the frame. The frame can, in addition, accept higher loads, which is particularly desirable when it is desired to machine heavier workpieces and when desired to use higher working pressures, higher power, etc. As a result of the bracing by the wall, the material cross sections of the frame can be further reduced, which further saves on costs and weight. By means of the reduced weight and using a construction of a large surface area bed, larger machine tools can be set up with a smaller surface loading of the floor.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following the invention will be explained in greater detail with the aid of a preferred embodiment which is illustrated in the drawings. There are shown in
FIG. 1--a top view of a frame for a machining center in accordance with the present invention,
FIG. 2--a vertical section along line I--I of FIG. 1,
FIG. 3--a vertical section along line II--II in FIG. 1,
FIG. 4--a side view of the machine frame of FIG. 1 from the right,
FIG. 5--a vertical section along line III--III in FIG. 1,
FIG. 6--a vertical section along line IV--IV in FIG. 1, and
FIG. 7--a vertical section along line V--V in FIG. 1.
DETAILED DESCRIPTION OF THE INVENTION
In order to also reduce the assembly costs, the frame consisting of the bed, the uprights, and the wall is preferably cast as a single piece. As the material therefor there is preferably used a polymerizable resin-concrete (polymer-concrete), a castable concrete comprised of mineral particles bound by a setting polymer resin. The casting of the frame can be executed with a sufficiently high precision, so that no expensive followup operation is necessary. In particular, ductwork and canals for the supply lines for the machine tools can be cast directly into the casting. The installation of these supply lines, for example electrical supply lines, control, hydraulic, cooling medium supply and withdrawal lines, turnings or chips removal, etc. can be easily accomplished.
The additional bracing by means of the wall allows, due to improved stability, a lower material cross sections of bed and uprights. This results not only in reduced weight and reduced material costs. There can also be hollowed out, also in the frame, larger hollow spaces, which can be additionally used to advantage. These hollow spaces could, for example, be used as coolant reservoirs with great volume capacity. The greater volume capacity makes possible a more effective cooling, which leads to a higher machining precision.
Besides these advantages, which are directly attributable to the reinforcement and stiffening of the frame, the wall can be used as a mounting member of the frame. The wall can be provided with guideways and carrier elements for a wide range of machine parts and machine tools. This brings with it a substantial savings in construction and assembly expenses.
Above all it becomes possible to provide the wall with those functional elements, which in conventional machine tools must be laterally positioned and assembled on the bed. The machine tool can herewith be erected elevationally, and requires a smaller standing room.
So, for example, the headstock of a machine tool can be provided beside the wall horizontally slidably guided on the bed. Above the space which is necessary for the movement of the headstock there can on the wall, for example on a bracket, a tool storage place be provided. Above the tool storage place there can be provided guideways, in which a handling-element is operably provided, for changing of the tools between the storage place and the working place of the machine tool. The wall which is additionally provided on the frame thus makes possible the provision of headstock, tool module or magazine, and handling equipment in three stages one above the other, whereby an exceptionally compact, space saving construction results.
Finally the unoccupied back surface of the wall can also be used as a mounting surface or casing wall for the necessary supply- and/or control means for the machine tool. Hereby there is achieved a further savings in space requirements and construction expense.
Turning now to the figures, the frame represented in the figures is intended for a machining center, in which the headstock with horizontal main spindle is displaceable along a horizontal plane, while the workpiece is mounted on a vertically displaceable workpiece table with vertical work holding plane. Main spindle and workpiece axis are thereby oriented at right angles to each other along a horizontal axis, so that cooling means and chips can freely fall downwardly.
The frame is comprised basically of a bed 10, a vertical upright 12 standing upon and associated with the bed 10, and a vertical wall 14. The unitary frame is cast as a single piece out of polymerizable resin-concrete.
The bed 10 is in the form of a flat, quadrilateral building stone and is formed of a quadrilateral bedplate 16 (side relationship approximately 2:1) with a circumscribing, upwardly directed rim 18, so that a basin like configuration of the bed 10 results. The inner area of the bed 10 is provided with upright standing crosspieces 20, which are variously arranged to run in part oriented longitudinally and in part oriented transversely along the bed 10 and abut on the rim 18. The crosspieces 20 partition the bed 10 into distinct, basin like receptacle spaces. These crosspieces 20 also serve to brace the bed 10. The bed 10 shows, as a result of the surrounding rim 18 and the crosspieces 20, even with a reduced material cross section and material content, a high stability against bending and twisting.
Near a narrow side of the bed 10 is disposed the vertical upright 12. Set into the upright 12 are vertical guide rails 24, which serve to guide a not shown sled, which carries the workpiece mounting table. Further there is integrated in the upright 12 a receptacle 26 for the not shown workpiece spindle of this sled.
The wall 14 is connected onto a longitudinally of the bed 10 running crosspiece 20. The wall 14 has a quadrilateral form, whereby its height essentially corresponds to the height of the uprights 12. The wall 14 is connected to the uprights 12 along a vertical edge. The wall 14 extends from the upright 12 along the longitudinal direction of the bed 10 up to the narrow edge of the bed 10 remote from the upright 12. In the cross-sectional direction of the bed 10 the wall 14 partitions the surface of the bed in approximately the ratio 1:3.
In the larger surface area section of the bed 10 between the wall 14 and the longitudinally running rim 18 there are provided, adjacent to the uprights 12, two parallel perpendicularly to the wall 14 running crosspieces 20, which on their upper edges carry crossrails 28. On the crossrails 28 there is set a not shown transverse displaceable sled, which parallel to the wall 14 carries longitudinal guiding means for the not shown headstock. The headstock with the horizontal and parallel to the wall 14 situated spindle is thereby in the area next to the wall 14 parallel to the wall (Z-axis) and on the crossrails 28 perpendicularly to the wall (Y-axis) displaceable.
At approximately half the height of the wall 14 projects a horizontal bracket 30 out of the planar surface of the wall 14. The bracket 30 extends in the illustrated embodiment in the from the uprights 12 oppositely facing region of the wall 14 over approximately 2/3 of the length of the wall. The height of the bracket 30 over the upper edge of the bed 10 is so selected, that the headstock in its terminal position can travel on the Z-axis with its rearward part under the bracket 30. The higher built-up front section of the headstock travels at the same time in front of the bracket 30. The bracket 30 is cast as a single piece into the wall 14. In order to provide supplemental support for the projecting bracket 30, there is provided a support 32 behind the area of travel of the headstock between a crosspiece 20 of the bed 10 and the bracket 30. The support 32 is likewise cast integrally with the bed 10, the wall 14 and the bracket 30.
On the bracket 30 there are set perpendicularly to the wall 14 oriented receiving rails 34. The receiving rails 34 are for receiving a not shown tool module.
On the horizontal upper edge of the wall 14 there are provided guideways 36, which extend along the entire length of the wall 14. On the guideways there is displaceably disposed a not shown handling element, with which tools can be exchanged between the on the bracket 30 disposed tool module and the main spindle of the headstock.
On the side of the wall 14 which is opposite the headstock and the bracket 30 there is to be found a free space 38 between the wall 14 and the rim 18. This free space 38 serves to receive supply means and energy providing lines of the machining center. In the free space 38 there are disposed the switch boxes 40 for the energy supply, the controllers, etc., which in the figures are indicated using dashed lines. The wall 14 can thereby simultaneously serve as the back wall of the switch boxes and for the mounting of the supply means.
The wall 14 has through holes for the connection of supply means. Further, there are incorporated in the crosspieces 20 of the bed 10 and in the uprights 12 canals and pipe conduits, through which the supply and control circuits are conducted. Further, the cooling circulation is conducted through such canals.
Below the work space of the machining center, which is defined in the bed 10 by the crossrails 28 and the front side of the upright 12 provided with the vertical guide rails 24, is the receiving groove 42 into which is set a chips exhaust 44. On the free narrow side of the bed 10 there is provided laterally adjacent the work space in the bed 10 a collection basin 46 for the dirty cooling medium. Out of this collection basin 46 the cooling medium is pumped through a filter and into a receiving space 22, which serves as a supply reservoir. From the supply reservoir the cooling medium is routed back to the work area for cooling.
Since the entire frame including bed 10, uprights 12, wall 14, with all described elements is cast as a single piece and in which also the installation canals and circuits are already incorporated, there results a substantial savings in assembly work and time. | 4y
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BACKGROUND OF THE INVENTION
At present, most of the more that 600,000 tons of regulated biomedical waste generated by hospitals, laboratories, clinics and medical offices in the United States are disposed of through means of off-site incineration. Such incineration, whether on-site or off-site gives rise to problems concerning compliance with the Federal Clean Air Standards Act which, as a result, have often raised capital and operating costs associated therewith to prohibitive levels.
Accordingly, some effort has been directed toward the creation of industrial sized autoclaving. However, this approach has been questioned because it cannot be assured that steam penetration will occur throughout an entire load of medical waste, given the variables of packaging and fluid volumes which may exist within any particular batch of medical waste. Further, autoclaving does not render the medical waste unrecognizable or reduce its volume. Thusly, it is unsuitable for disposal in already overcrowded landfills.
Most importantly, the storing costs and liability have caused increasingly more health care institutions to turn away from having their waste hauled to off-site treatment. However, the problem of satisfactory means of on-site treatment, by whatever means, still exists.
Prior art approaches to medical waste fragmentation and disposal, other than the approaches of autoclaving and incineration include efforts at encapsulating the contaminated waste, typically in a thermoplastic compound. Such efforts are taught in U.S. Pat. No. 4,979,683 to Busdeker, entitled Portable Small Scale Medical Waste Treatment Machine and U.S. Pat. No. 4,992,217 (1991) to Spinello, entitled Apparatus and Method For Sterilizing, Destroying And Encapsulating Medical Implement Wastes.
There is further known in the art, a number of special purpose medical waste grinders having potential value in smaller or portable type disposal systems. Such grinding approaches are shown in U.S. Pat. No. 4,971,261 (1990) to Solomons, entitled Medical Waste Fragmentation and Disposal System, and U.S. Pat. No. 5,025,994 (1991) to Maitlen, et al, entitled Medical Waste Grinder.
The use of microwaves in the disinfecting of medical waste, which comprises one aspect of the present system, is shown, with reference to the treatment of sludge in U.S. Pat. No. 5,003,143 (1991), entitled Microwave Sludge Drying Apparatus and Method. Further, the use of microwaves in a medical disinfectant system for the treatment of medical waste exists in a system commercially available from ABB Sanitec, Inc., Division of Asea Brown Boveri, known as the ABB Sanitec Microwave Disinfection System. The Sanitec system has been used in Europe since 1984 and in the United States since 1990. The Sanitec system employs two basic steps--the first that of shredding the medical waste and the second that of steam-treating the ground waste while exposing the same to microwaves.
The Sanitec system suffers from a number of problems that have limited its use in the United States. One of these is that many states do not permit infectious waste to be ground prior to treatment because such grinding creates an additional risk of exposing hospital workers to infection. It is asserted by many state regulators that when medical material containing infectious agents are manipulated and disrupted, such waste, particularly waste containing aerosols, containing micro-organism are released, people can become infected through the mouth, nose and eyes as well as transdermally. A second difficulty with the Sanitec system is that its normal operating temperature, in the microwave portion thereof, is that of 203 degrees Fahrenheit. This specialists in the applicable field (which is known as epidemiology), have asserted is inadequate to confidently kill the test organism Bacillus strarochermophilus. Accordingly, the prior art of medical waste disposal and disinfection systems which employ microwaves have suffered from problems at the input stage regarding the possible release of infectious agents during the grinding step and, as well, at the output thereof because of inadequate temperature.
The instant invention addresses the above shortcomings of microwave and other prior art approaches of to medical waste disposal. In so doing there is provided a system concept applicable to various sized system including one that can easily be used within most doctors offices and, one that can be used on-site at a hospital and, finally, an industrial sized system which can be used off-site at designated medical waste disposal locations.
SUMMARY OF THE INVENTION
The inventive medical waste disposal system comprises a fluid-tight drum for superheating a quantity of untreated medical waste that is at least partially water-saturated, to at least 275 degrees Fahrenheit for at least thirty minutes, said fluid-tight means having a selectably openable and closeable input. The drum will deposit its contents into a matrix of grinding elements having surfaces of respectively different grinding dimensions, said grinding dimensions proportioned to dimensions of the medical waste to be processed. The system further includes means for exposing to microwave energies, the ground waste output of said matrix of grinding elements, said microwave exposing means including water-misting means directed to the medical waste material prior to microwaving to assure an uniform microwave penetration which will heat the ground waste to a temperature of about 270 degrees (the normal operating temperature of an autoclave). After microwaving, the treated waste is deposited into a disposal chute into which may, optionally, be incorporated compaction means and/or encapsulation means. All openings of the system to the external environment are covered by hepa-filters to catch any potentially harmful airborne pathogens that may not have been neutralized by the system.
It is an object of the present invention to provide a medical waste disposal system, the output thereof may be treated as conventional solid garbage or waste.
It is another object of the invention to provide a medical waste disposal system which can be made in small and portable units suitable for use within a doctor's office and upon hospital grounds.
It is a further object of the present invention to provide a medical waste disposal system which does not in the normal operation thereof create any emissions into the atmosphere.
It is a yet further object of the invention to provide a medical waste disposal system having a sufficiently high operating temperature to kill any known test bacteria or organism.
It is another object to provide a waste disposal system having redundancy of disinfecting capability.
It is yet another object to provide a medical waste disposal system in which one level of disinfection occurs prior to mechanical manipulation of the medical waste.
The above and yet other objects and advantages of the present invention will become apparent from the hereinafter set forth Brief Description of the Drawings, Detailed Description of the Invention and Claims appended herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment of the present invention.
FIG. 2 is a side schematic view of the embodiment of FIG. 1.
FIG. 3 is an enlarged schematic view of the superheated steam containing vessel of the inventive system.
FIGS. 4A thru 4C are a sequence of views showing the loading, operation and dispensing respectively of the super-heated steam containing vessel shown in FIG. 3. Also, FIG. 4A is a radial cross-sectional view taken along Line 4--4 of FIG. 2.
FIG. 5 is a front schematic view of the embodiment of FIG. 1.
FIG. 6 is a top schematic view of the microwave portion of the system.
FIG. 7 is a perspective view of a second embodiment of the instant system.
FIG. 8 is a rear plan view of the embodiment of FIG. 7.
FIG. 9 is a side schematic view of the embodiment of FIG. 7.
FIG. 10 is a top schematic view of the embodiment of FIG. 7.
DETAILED DESCRIPTION OF THE INVENTION
With reference to FIG. 1 there is shown a housing 10 of a first embodiment of the invention having, therein, an input opening 12 and a chute-like output opening 14.
With reference to FIG. 2 a number of the interior mechanical components are shown in schematic view. More particularly, at the bottom of the chute of opening 12 is shown a vessel which is in the nature of an elongated drum 16 shown in greater detail in FIGS. 3 and 4.
In FIG. 3 it may be seen that vessel 16 is axially mounted upon axles 18 and 20 to the interior walls of housing 10 and, through the use of motor 22, may be rotated when it is entirely sealed.
Drum 16 is shown in radial cross-sectional in views FIGS. 4A thru 4C. Therein it may be noted that drum 16 includes of an inner drum 24 and an outer drum 26. Each of said drums are provided with separate longitudinal openings 28 and 30 respectively which openings must be opened to load drum 24 and both of which must be opened to release contents thereof in the manner shown in FIG. 4C. Openings 28 and 30 are closed prior to disinfecting of the contents thereof. This disinfecting occurs after a quantity of water from outlet 31, has filled the lower two or three inches of drum 24, after medical waste 32 has past through openings 28 and 30 of drums 24 and 26. It is noted that inner drum 24 is surrounded by a spiral of resistance heating elements 34. The function of these elements is to heat the surface of inner drum 24 to a temperature in excess of 300 degrees F. such that the interior of inner drum 24 will function in a manner analogous to that of a pressure cooker, that is, the containment of superheated gas which is indicated by dots 36 in FIG. 4B. The superheated gas will completely permeate medical waste 32 such that the heat values within inner drum 24 will extend to every pore and granule of the waste. Also, in the event that there are aerosol-containing capsules within waste 32, such containers will quickly burst within inner drum 24 and the contents thereof will be rapidly disinfected by the pressure and heat of the superheated steam within the inner drum 24.
After a period of about fifteen minutes the resistance heating elements 34 on the surface of inner drum 24 are turned-off. Thereupon the inner and outer drum is rotated per FIG. 4B. It is noted that fins 40 are provided upon the external surface of inner drum 24 such that when the drum is are rotated in the direction indicated by arrow 42 a maximum cooling effect will be imparted to both drums. Holes 43 are provided in outer drum 26 to facilitate escape of heat.
After the temperature within inner drum 24 has fallen below 100 degrees F., the doors 28 and 30 of the respective drums will be oriented downward in the manner shown in FIG. 4C. This will enable the disinfected waste 32 to be dropped downwardly into a matrix 44 of cylindrical grinding elements. The use of a plurality of grinding elements assures that no part of the waste will escape disintegration and, as well, thermal values will be further dispersed during the grinding process. It is to be appreciated that the surfaces of the elements in matrix 44 will possess a variety of configurations such that grinding of maximum efficiency of a broad range of configurations of medical waste will be efficiently accomplished. That is, small grinding surfaces are necessary to grind small items such as hypodermic needles, while larger grinding surfaces are necessary to grind materials having larger dimensions, such as cans or canisters. Accordingly, the top level of grinding element many possess a larger dimension surfaces, the second level somewhat smaller dimension grinding surfaces, and the lowest level of grinding matrix 44 the smallest gauge grinding capability.
Ground medical material is discharged from grinding matrix 44 into compartment 46 of a "lazy susan" type of receiving means 48 which is shown in top view in FIG. 6. Therein it may be noted that the material from compartment 44 is then advanced in direction 50 into exposure to a plurality of microwave elements 52. While each compartment 46 is moving from the position shown at the right of FIG. 6 to the position at the left of FIG. 6, a mist of water that is, water vapor is sprayed thru conduit 53 upon the waste to assure that the microwaving will thoroughly and uniformly penetrate the waste 32. In FIG. 2 there is shown, about microwave elements 52, microwave insulation 54 which assures that radiation will not escape from the housing 10. The Effect of the microwaving is to expose the waste to a temperature of about 275 degrees Fahrenheit for a period of at least thirty minutes. Accordingly, disinfecting occurs both at the beginning and end of the present system such that any pathogens or other infectious material not neutralized at the input step are neutralized at the output step of the system. After microwaving is accomplished the bottom of lazy susan receiving means 48 opens so that the processed waste will drop down chute 56 to output opening 14. It is to be noted that, followed the microwaving step, use may be made of known state of the art compacting and/or encapsulating means (see Background of the Invention) to assure that the medical waste, even after processed, cannot be touched by a medical worker, notwithstanding the fact that after processing in accordance with the present system, there is no necessity to treat the processed waste in any fashion different from that of ordinary residential trash. Therefore, output 14 will typically include a thick gauge plastic bag, e.g., one of five mils such that the output from lazy susan means 46 will be effectively deposited into a bag that a hospital waste disposal worker need do nothing more to than close. It is noted that area 58 (see FIG. 2) is reserved for control electronics of the system.
A second embodiment of the present inventive means is shown in FIGS. 7 thru 10. This system differs from the above described embodiments of FIGS. 1 thru 6 in that it is adapted for larger quantity applications, such as a hospital site, as opposed to within a doctor's office. In this embodiment, the medical waste, after the superheating step involving drums 24 and 26, is dropped onto a conveyor belt 160 and, therefrom, into grinding matrix 144. In the same fashion as in the initially described embodiment, the output of grinding matrix 144 will drop into a first compartment 146 (see FIG. 10) of lazy susan means 148 and, thereafter, will be exposed, at the right side thereof to microwave means 152. It is noted that grinding matrix 144, lazy susan means 148 and microwave assembly 152 differ from that of the first embodiment only in physical dimension. The output of the microwave material is then dropped onto a second conveyor belt means 162 and, therefrom, to output 114. Compaction means will typically be combined with the output area 114 in the system of the embodiment of FIGS. 7 thru 10 in that larger volumes of materials are contemplated.
It is to be appreciated that the second embodiment of the invention described above may be upsized indefinitely as, for example, where off-site medical waste disposal and disinfection are desired.
It has been found that by providing disinfection functions at both the input of all embodiments of the present system, even the most hearty of pathogens will be neutralized. No known pathogens can withstand an operating temperature of more than 270 degrees Fahrenheit which is achieved at both beginning and end of the system.
It is also noted that, at all potential interfaces with the external environment, the embodiments of the instant system are provided with so-called hepa-filters to eliminate any potential, however remote, that may exist for the airborne transmission of pathogens from the system.
It is also noted that the above described system responds to a limitation in prior art microwave approaches to medical waste processing by providing a pathogen neutralizing capability prior to the grinding step such that no mechanical manipulation or disruption of material occurs prior to grinding. Further, in the event that aerosols are contained within particular load of medical waste, there is provided a thick gauge superheating drum 24 such that even the explosion of an aerosol canister would have no effect on the mechanical integrity of the drum 24. No known prior art approach accounts for the possibility of the explosion of an aerosol during the treatment thereof with, thereby, the potential for airborne release of pathogens.
Accordingly, while there has been shown and described the preferred embodiment of the present invention (the embodiment of FIGS. 1 thru 6), it to be appreciated that the invention may be practiced otherwise that is herein specifically shown and described and that, within such embodiment, certain changes may be made in the form and arrangement of the parts without departing from the underlying idea or principles of this invention, within the scope of the Claims appended herewith. | 4y
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TECHNICAL FIELD
[0001] The present invention relates to methods and devices for cleaning air to purify indoor air polluted by dust, germs, and the like.
BACKGROUND ART
[0002] At present, indoor air in houses, hospitals, buildings, and the like, has been increasingly polluted. Pollutants include dust, molds, ticks, pollens, and various pathogenic germs including influenza viruses, tuberculosis bacteria, methicillin-resistant Staphylococcus aureus (MRSA) as nosocomial infectious bacteria, Legionella bacteria, coronaviruses such as severe acute respiratory syndrome (SARS) viruses, noroviruses, campylobacter, O-157 as food-poisoning germs, and the like. These various kinds of pollutants including floating fungus and airborne infectious germs are suspended in indoor space or attached to indoor wall surfaces, ceilings, furniture, and the like, to thereby deteriorate indoor environments and exert enormous harmful effects on human bodies.
[0003] There is suggested an air cleaning device for purifying indoor air polluted by the foregoing pollutants (hereinafter, referred to as “polluted air”) that includes: a wind tunnel with an air inlet and an air outlet vertically arranged; a fan which takes polluted air into the wind tunnel from the air inlet and discharges the same from the air outlet; a nozzle which scatters liquid pressurized by a pump to an entire air path of the wind tunnel; and a collection tank for collecting the liquid, in which the polluted air taken by the fan into the wind tunnel contacts the liquid scattered from the nozzle, whereby the polluted air is purified (for example, refer to Patent Document 1).
[0004] In addition, there is suggested another air cleaning device in which pumped-up water is reflected on a mushroom-shaped reflector and turned into a spray of water, and polluted air taken in by an intake fan from an upper entry of a housing contacts the spray of water spreading over the housing, whereby the polluted air is purified (for example, refer to Patent Document 2).
[0005] Further, there is suggested another air cleaning device that includes: a housing retaining cleaning water; an air blower which is arranged above the cleaning water to blow polluted air downward from a fan; and a guide which extends from an lower end of the air blower into the cleaning water, increases in diameter downward, has a rib as a spiral projection therein, and is fixed to a rotation shaft of the air blower so as to rotate together with the fan, in which the polluted air blown downward by the fan contacts the cleaning water transferred upward by the rotation of the guide, whereby the polluted air is purified (for example, refer to Patent Document 3).
CITATION LIST
Patent Literature
[0006] Patent Document 1: JP-A No. 7-17324
[0007] Patent Document 2: EP Application Public-disclosure No. 1506805 specification
[0008] Patent Document 3: JP-A No. 2008-520424
SUMMARY OF INVENTION
Technical Problem
[0009] The air cleaning device described in Patent Document 1 requires a pump and a nozzle, which leads to increase of manufacturing costs. In addition, the air cleaning device of Patent Document 1 is configured to let polluted air contact the surface of water drops scattered from a nozzle, but the time of contact between the liquid and the polluted air is comparatively short. This results in insufficient purification of the polluted air which may reduce the efficiency of removing germs and the like.
[0010] The air cleaning device described in Patent Document 2 requires a pump and a reflector, which leads to increase of manufacturing costs. In addition, the air cleaning device of Patent Document 2 is configured to let polluted air contact the surface of water mist spreading into a housing, but the time of contact between the liquid and the polluted air is comparatively short. This results in insufficient purification of the polluted air which may reduce the efficiency of removing germs and the like.
[0011] The air cleaning device described in Patent Document 3 is configured to have a guide extended from the lower end of an air blower into cleaning water and fixed to a rotation shaft of the air blower so as to rotate together with the rotation shaft. This requires a large-capacity motor for rotating the air blower fan and the guide, and complicates a support structure of the rotation shaft, which leads to increase in consumption of energy such as electric power and manufacturing costs.
[0012] In addition, even if the air cleaning device of Patent Document 3 is configured in such a manner that the guide extended into the cleaning water and increased in diameter downward does not rotate but the air blower fan rotates alone, the lower opening of the guide for blowing the polluted air is positioned in the cleaning water, which requires a large capacity air blower due to a high resistance of the cleaning water. This also brings about increase in consumption of energy such as electric power and manufacturing costs.
[0013] In light of the foregoing circumstances, an object of the present invention is to provide an air cleaning method and device that realize sufficient purification of polluted air, high-efficiency removal of germs and the like from polluted air, a relatively simplified structure, and suppression of increase in manufacturing costs.
Solution to Problem
[0014] To solve the foregoing issue, an air cleaning method of the present invention includes: pressurizing by an air blower air taken into a container main body containing a liquid as sterilizing fluid, deodorant fluid, or water; blowing the air pressurized by the air blower into a cylindrical body which has upper and lower openings and extends in a vertical direction, from the upper opening, the lower opening being an air blowing port separated from a surface of the liquid; blowing out of the lower opening, the air blown from the upper opening into the cylindrical body and rotating and descending in a spiral manner, so as to collide with the liquid, plunging the air into a bottom of a liquid containing part for containing the liquid in the container main body, and agitating and mixing the air and the liquid; and raising the air agitated and mixed with the liquid on an outside of the cylindrical body, and discharging the same to an outside of the container main body.
[0015] According to this configuration, the air taken into the container main body is pressurized by the air blower, and rotates and descends in a spiral manner by rotation of blades of the air blower and contact with the inner wall surface of the cylindrical body, and is blown out of the lower opening as an air blowing port toward the liquid surface, and collides with the liquid and plunges into the bottom of the liquid containing part (container bottom), and is agitated and mixed with an approximately total amount of the liquid as if the air is washed by the liquid. Therefore, the air taken into the container main body is allowed to contact the liquid with efficiency.
[0016] Accordingly, it is possible to remove pollutants such as dust, dirt, molds, ticks, pollens, and the like, in an efficient manner. In addition, if the liquid is sterilizing fluid, it is also possible to kill and remove pollutants such as viruses, germs, and the like, in an efficient manner. If the liquid is deodorant fluid, it is possible to eliminate bad odors of cigarette, formalin, and the like, in an efficient manner. If the liquid is water, it is possible to remove dust from construction sites, plants, and the like, in an efficient manner.
[0017] In addition, the thus configured air cleaning device does not require a pump or a nozzle as described in Patent Document 1 or a pump or a reflector as described in Patent Document 2. Further, this air cleaning device is not configured to rotate a guide fixed to the rotation shaft of the air blower and extended into the cleaning water as in Patent Document 3, and therefore the cylindrical body positioned under the air blower is not driven and the lower opening of the cylindrical body as an air blowing port is separated from the surface of the liquid. This does not require a large-capacity air blower or motor or a complicated structure, which makes it possible to suppress increase in consumption of energy such as electric power and manufacturing costs.
[0018] To solve the foregoing issue, an air cleaning method of the present invention includes: pressurizing by an air blower air taken into a container main body containing a liquid as sterilizing fluid, deodorant fluid, or water; blowing the air pressurized by the air blower into a cylindrical body which has upper and lower openings and extends in a vertical direction, from the upper opening, the lower opening being an air blowing port separated from a surface of the liquid; pumping up and pressurizing the liquid, and ejecting the liquid upward from the nozzle so as to collide with a reflector separated inward from the cylindrical body; contacting the air blown from the upper opening into the cylindrical body and rotating and descending in a spiral manner with the liquid colliding with and scattered by the reflector; causing a mixture of the air falling from the cylindrical body and the scattered liquid to collide with a puddle of liquid in the container main body, plunging the mixture into a bottom of a liquid containing part for containing the liquid in the container main body, and agitating and mixing the air with the liquid; and raising the air agitated and mixed with the liquid on an outside of the cylindrical body and discharging the same to an outside of the container main body.
[0019] According to this configuration, the air taken into the container main body is pressurized by the air blower, and rotates and descends in a spiral manner by rotation of the blades of the air blower and contact with the inner wall surface of the cylindrical body, and the liquid as a jet flow ejected from the nozzle is scattered by collision with the reflector separated inward from the cylindrical body, and the air rotating and descending in a spiral manner and the liquid colliding with and scattered by the reflector are brought into contact within the cylindrical body, and a mixture of the air and the liquid sharply falls in a bubble state.
[0020] The bubbled mixture collides with the liquid contained in the lower part of the container, and penetrates through the puddle of liquid and plunges into the bottom of the liquid containing part (container bottom). Accordingly, the entire liquid puddle is also strongly agitated and mixed in a spiral manner so as to bubble, swell, and increase in volume, as if the air is washed by the liquid. Therefore, the air taken into the container main body is allowed to contact the liquid with extremely high efficiency.
[0021] Accordingly, it is possible to remove pollutants such as dust, dirt, molds, ticks, pollens, and the like, in a highly efficient manner. In addition, if the liquid is sterilizing fluid, it is also possible to kill and remove pollutants such as viruses, germs, and the like, in a highly efficient manner. If the liquid is deodorant fluid, it is possible to eliminate bad odors of cigarette, formalin, and the like, in a highly efficient manner. If the liquid is water, it is possible to remove dust from construction sites, plants, and the like, in a highly efficient manner.
[0022] Besides, if the air taken in from the air inlet is hot wind, for example, the hot wind can be cooled down by airborne droplets of the liquid colliding with and reflected on the reflector and scattered in various directions. In addition, since the liquid as a jet flow collides from below with the reflector heated by transfer of forced convection heat from the hot wind, the hot wind can be cooled down via the reflector by high-efficiency colliding jet cooling. Accordingly, in any of cases where the liquid is sterilizing fluid or deodorant fluid or water, this configuration is suited for cooling hot air in working sites or the like at high temperatures.
[0023] Moreover, differently from the configuration described in Patent Document 3 with rotation of the guide fixed to the rotation shaft of the air blower and extended in the cleaning water, in this configuration, the cylindrical body arranged under the air blower is not driven and the lower opening of the cylindrical body as an air blowing port is separated from the surface of the liquid, which eliminates the need for a large-capacity air blower or motor and prevents a structure from being complicated. This makes it possible to suppress increase in consumption of energy such as electrical power and manufacturing costs.
[0024] In this arrangement, it is preferred to raise the air agitated and mixed with the liquid on the outside of the cylindrical body and remove the liquid from the air in the middle of a flow path for discharging the air to the outside of the container main body.
[0025] According to this configuration, the air agitated and mixed with the liquid is raised and cleared of the liquid before being discharged to the outside of the container main body. This makes it possible to suppress a content of the liquid in the discharged air and reduce decrease in amount of the liquid in the container main body, thereby to realize longer time intervals between tasks of refilling the liquid.
[0026] To solve the foregoing issue, an air cleaning device in the present invention includes: a container main body which contains a liquid as sterilizing fluid, deodorant fluid, or water; a cylindrical body which has upper and lower openings and extends in a vertical direction, which is arranged within the container main body such that the lower opening is separated from a surface of the liquid; an air blower which is arranged above the cylindrical body within the container main body, and pressurizes the air taken in from the air inlet of the container main body, and blows the same from the upper opening as an air blowing port into the cylindrical body; and an air outlet which is formed on an outside of the cylindrical body of the container main body, wherein the air blown by the air blower from the upper opening into the cylindrical body, rotates and descends in a spiral manner and is blown out from the lower opening as an air blowing port, and collides with the liquid and plunges into a bottom of a liquid containing part for containing the liquid in the container main body, and is agitated and mixed with the liquid, and
[0027] the air agitated and mixed with the liquid is raised on the outside of the cylindrical body and is discharged from the air outlet.
[0028] According to this configuration, the air taken in from the air inlet is pressurized by the air blower, and rotates and descends in a spiral manner by rotation of blades of the air blower and contact with the inner wall surface of the cylindrical body, and is blown out of the lower opening as an air blowing port toward the liquid surface, and collides with the liquid and plunges into the bottom of the liquid containing part (container bottom), and is agitated and mixed with an approximately total amount of the liquid as if the air is washed by the liquid. Therefore, the air taken in from the air inlet is allowed to contact the liquid with efficiency.
[0029] Accordingly, it is possible to remove pollutants such as dust, dirt, molds, ticks, pollens, and the like, in an efficient manner. In addition, if the liquid is sterilizing fluid, it is also possible to kill and remove pollutants such as viruses, germs, and the like, in an efficient manner. If the liquid is deodorant fluid, it is possible to eliminate bad odors of cigarette, formalin, and the like, in an efficient manner. If the liquid is water, it is possible to remove dust from construction sites, plants, and the like, in an efficient manner.
[0030] In addition, the thus configured air cleaning device does not require a pump or a nozzle as described in Patent Document 1 or a pump or a reflector as described in Patent Document 2. Further, this air cleaning device is not configured to rotate a guide fixed to the rotation shaft of the air blower and extended into the cleaning water as in Patent Document 3, and therefore the cylindrical body positioned under the air blower is not driven and the lower opening of the cylindrical body as an air blowing port is separated from the surface of the liquid. This does not require a large-capacity air blower or motor or a complicated structure, which makes it possible to suppress increase in consumption of energy such as electric power and manufacturing costs.
[0031] In this arrangement, a bar-like body is preferably provided so as to stand on the bottom of the liquid containing part and extend toward an approximate center of the cylindrical body.
[0032] According to this configuration, the bar-like body brings about a smaller passage section of the air blown out of the cylindrical body and colliding with the liquid. This increases a pressure of the air rotating and descending in a spiral manner, thereby to facilitate the agitation and mixture of the air and the liquid.
[0033] Therefore, the air taken in from the air inlet can contact the liquid with higher efficiency.
[0034] In addition, baffles are preferably provided so as to project from the bottom or side of the liquid containing part.
[0035] According to this configuration, the agitation and mixture of the air spirally rotating and descending and the liquid can be facilitated by the agitation facilitating effect of the baffles. This allows the air taken in from the air inlet to contact the liquid with higher efficiency.
[0036] Further, an agitator is preferably arranged on the bottom of the liquid containing part.
[0037] According to this configuration, the agitation and mixture of the air spirally rotating and descending and the liquid can be facilitated by the agitation facilitating effect of the agitator. This allows the air taken in from the air inlet to contact the liquid with higher efficiency.
[0038] To solve the foregoing issue, an air cleaning device in the present invention includes: a container main body which contains a liquid as sterilizing fluid, deodorant fluid, or water; a cylindrical body which has upper and lower openings and extends in a vertical direction, which is arranged within the container main body such that the lower opening is separated from a surface of the liquid; an air blower which is arranged above the cylindrical body within the container main body, and pressurizes the air taken in from the air inlet of the container main body, and blows the same from the upper opening as an air blowing port into the cylindrical body; a pump which pumps up and pressurizes the liquid; a nozzle which is upwardly attached to a discharging port of the pump; a reflector which is provided above the nozzle, and is separated inward from the cylindrical body, and collides with the liquid as a jet flow ejected from the nozzle and reflects the same; and an air outlet which is formed on an outside of the cylindrical body of the container main body, wherein the air blown by the air blower from the upper opening into the cylindrical body, rotates and descends in a spiral manner, and contacts the liquid colliding with and scattered by the reflector, and a mixture of the air falling from the lower opening as an air blowing port and the scattered liquid collides with a puddle of liquid in the container main body and plunges into a bottom of a liquid containing part for containing the liquid in the container main body, and is agitated and mixed with the liquid, and the air agitated and mixed with the liquid is raised on the outside of the cylindrical body and discharged from the air outlet.
[0039] According to this configuration, the air taken into the container main body is pressurized by the air blower, and rotates and descends in a spiral manner by rotation of the blades of the air blower and contact with the inner wall surface of the cylindrical body, and the liquid as a jet flow ejected from the nozzle is scattered by collision with the reflector separated inward from the cylindrical body, and the air rotating and descending in a spiral manner and the liquid colliding with and scattered by the reflector are brought into contact within the cylindrical body, and a mixture of the air and the liquid sharply falls in a bubble state.
[0040] The bubbled mixture collides with the liquid contained in the lower part of the container, and penetrates through the puddle of liquid and plunges into the bottom of the liquid containing part (container bottom). Accordingly, the entire liquid puddle is also strongly agitated and mixed in a spiral manner so as to bubble, swell, and increase in volume, as if the air is washed by the liquid. Therefore, the air taken into the container main body is allowed to contact the liquid with extremely high efficiency.
[0041] Accordingly, it is possible to remove pollutants such as dust, dirt, molds, ticks, pollens, and the like, in a highly efficient manner. In addition, if the liquid is sterilizing fluid, it is also possible to kill and remove pollutants such as viruses, germs, and the like, in a highly efficient manner. If the liquid is deodorant fluid, it is possible to eliminate bad odors of cigarette, formalin, and the like, in a highly efficient manner. If the liquid is water, it is possible to remove dust from construction sites, plants, and the like, in a highly efficient manner.
[0042] Besides, if the air taken in from the air inlet is hot wind, for example, the hot wind can be cooled down by airborne droplets of the liquid colliding with and reflected on the reflector and scattered in various directions. In addition, since the liquid as a jet flow collides from below with the reflector heated by transfer of forced convection heat from the hot wind, the hot wind can be cooled down via the reflector by high-efficiency colliding jet cooling. Accordingly, in any of cases where the liquid is sterilizing fluid or deodorant fluid or water, this configuration is suited for cooling hot air in working sites or the like at high temperatures.
[0043] Moreover, differently from the configuration described in Patent Document 3 with rotation of the guide fixed to the rotation shaft of the air blower and extended in the cleaning water, in this configuration, the cylindrical body arranged under the air blower is not driven and the lower opening of the cylindrical body as an air blowing port is separated from the surface of the liquid, which eliminates the need for a large-capacity air blower or motor and prevents a structure from being complicated. This makes it possible to suppress increase in consumption of energy such as electrical power and manufacturing costs.
[0044] In this arrangement, a guide body is preferably provided within the cylindrical body under the reflector so as to receive the liquid colliding with and reflecting on the reflector, and guide the same outward.
[0045] According this configuration, a part of the liquid scattered by collision with the upper guide body, further collides with the lower guide body, and is guided outward and scatters by the lower guide body. Accordingly, airborne droplets of the scattered liquid are guided into a mixing space inside the cylindrical body. This increases the density of airborne droplets of the liquid within the mixing space, which allows the air taken in from the outside to contact the liquid with higher efficiency.
[0046] Further, a liquid removing means is preferably provided in the middle of a flow path for raising the air agitated and mixed with the liquid on the outside of the cylindrical body and discharging the same from the air outlet.
[0047] According to this configuration, the air agitated and mixed with the liquid is raised and cleared of the liquid by a liquid removing means before being discharged to the outside of the container main body. This makes it possible to suppress a content of the liquid in the discharged air and reduce decrease in amount of the liquid in the container main body, thereby to realize longer time intervals between tasks of refilling the liquid.
Advantageous Effects of Invention
[0048] As in the foregoing, according to the air cleaning method and device in the present invention, the air taken into the container main body and pressurized by the air blower, is blown from the upper opening into the cylindrical body with the lower opening (blowing port) separated from the surface of the liquid, so as to rotate and descend in a spiral manner, and the air is strongly blown out of the lower opening as a blowing port toward the liquid surface, or a mixture formed by contacting the air spirally rotating and descending within the cylindrical body with the liquid colliding with and scattered by the reflector, is strongly blown out of the lower opening toward the liquid surface, such that the mixture collides with the liquid puddle and plunges into the bottom of the liquid containing part, whereby the air taken into the container main body is agitated and mixed with the liquid. This allows the air to contact the liquid with efficiency, thereby achieving sufficient purification of the polluted air. Accordingly, these method and device provide significant advantages of removing efficiently germs and the like from the polluted air, simplifying the structure, and suppressing increase of manufacturing costs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] FIG. 1 is a perspective view of an air cleaning device in an embodiment of the present invention;
[0050] FIG. 2 is a partial longitudinal sectional view of the same;
[0051] FIG. 3 is a partial longitudinal sectional view of a configuration in which a bar-like body is provided so as to stand on a bottom of a liquid containing part of a container main body;
[0052] FIG. 4 is a partial longitudinal sectional view of a configuration in which baffles are provided so as to project from the bottom of the liquid containing part of the container main body;
[0053] FIG. 5 is a partial longitudinal sectional view of a configuration in which an agitator is arranged on the bottom of the liquid containing part of the container main body; and
[0054] FIG. 6 is a partial longitudinal sectional view of a configuration in which air spirally rotating and descending within a cylindrical body and liquid scattered by collision with a reflector, are contacted and mixed together.
DESCRIPTION OF EMBODIMENTS
[0055] The perspective view in FIG. 1 shows an embodiment with an air cleaning device 1 for indoor use, for example, domestic use, which is brought into an operational state by inserting a power plug 22 at a leading end of a power cord 21 into a socket not shown and then turning on a switch 23 .
[0056] When the air cleaning device 1 is in the operational state, polluted air PA is taken in from air inlets 5 , 5 , . . . formed at an upper part of a side surface of a container main body 2 . The polluted air PA contacts sterilizing fluid, deodorant fluid, or water, contained in the container main body 2 , and then is discharged as clean air CA with no unpleasant odor, from air outlets 6 , 6 , . . . .
[0057] In this arrangement, since downwardly-inclined louvers 7 , 7 , . . . are provided at upper edge portions of the air outlets 6 , 6 , . . . , the clean air CA is discharged downward from the air outlets 6 , 6 , . . . , thereby to suppress suction of the clean air CA from the air inlets 5 , 5 , . . . .
[0058] As shown in the partial longitudinal sectional view of FIG. 2 , the air cleaning device 1 in the embodiment of the present invention includes: the container main body 2 that contains liquid A as sterilizer, deodorizer, or water in a liquid container 2 A; a cylindrical body 3 with upper and lower openings 3 A and 3 B that is arranged within the container main body 2 and extends in a vertical direction such that the lower opening 3 B is separated from a surface of the liquid A; an air blower 4 that is arranged above the cylindrical body 3 within the container main body 2 , pressurizes the polluted air PA taken in from the air inlets 5 , 5 , . . . of the container main body 2 , and blows the same into the cylindrical body 3 from the upper opening 3 A as an air blowing port; and the air outlets 6 , 6 , . . . formed on an outside of the cylindrical body 3 of the container main body 2 .
[0059] As shown in FIGS. 1 and 2 , the container main body 2 of the air cleaning device 1 is an approximately circular cylinder in appearance, and is configured in such a manner that a liquid container 2 A which serves as a liquid containing part for containing the liquid A and has the louvers 7 , 7 , . . . on a side surface of an upper part thereof and the air outlets 6 , 6 , . . . as long holes extending in a circumferential direction under these louvers 7 , 7 , . . . , is connected by a connecting member 2 C to an air blower assembly 2 B which has the air inlets 5 , 5 , . . . as a large number of round holes on the side surface thereof.
[0060] In addition, the cylindrical body 3 extending in a vertical direction and having the upper and lower openings 3 A and 3 B, is arranged above the liquid A and under the air blower 4 within the container main body 2 , such that the lower opening 3 B as an air blowing port is separated from the liquid A. Arranged on an outside of the cylindrical body 3 are upper and lower metal draining meshes 8 and 9 as liquid removing means.
[0061] The liquid removing means may not be metal draining meshes but may be filters, impellers, cyclone centrifugal separators, or the like.
[0062] The polluted air PA taken in from the air inlets 5 , 5 , . . . is pressurized by the air blower 4 and blown from the upper opening 3 A into the cylindrical body 3 . The polluted air PA then rotates and descends in a spiral manner by rotation of blades of the air blower 4 and contact with an inner wall surface of the cylindrical body 3 , and is blown out of the lower opening 3 B as an air blowing port toward the liquid surface so as to collide with the liquid A, and plunges into a container bottom (a bottom of the liquid container 2 A), and then is agitated and mixed with the liquid A. The clean air CA having been agitated and mixed with the liquid A is raised on the outside of the cylindrical body 3 , and then is discharged from the air outlets 6 , 6 , . . . .
[0063] Arranging a whorl-like grill or the like under the blades of the air blower 4 can provide a stronger spiral rotating force.
[0064] In this arrangement, the degree of agitation and mixture of the polluted air PA and the liquid A depends on specification data such as air volume and air pressure at the air blower 4 , shape and length in a vertical direction of the cylindrical body 3 , and amount (depth) of the liquid A. For example, if the cylindrical body 3 is too short in a vertical direction, the polluted air PA does not descend in a spiral manner or descends in a weaken spiral manner, and if the cylindrical body 3 is too long in a vertical direction, larger friction loss is generated to lower the air pressure. In either case, there is a tendency that the polluted air PA and the liquid A are agitated and mixed to a lowered degree.
[0065] Therefore, according to the specifications of air purifying performance and the like required for the air cleaning device 1 , the foregoing specification data is determined by experiment or simulation or the like, such that the polluted air PA pressurized by the air blower 4 and blown into the cylindrical body 3 rotates and descends in a spiral manner so as to collide with the liquid A, and plunges into the container bottom, and then is agitated and mixed to a desired degree.
[0066] For reference, Tables 1 to 3 show results of testing at which mixing states of the air and the liquid are observed with a distance set at 20 mm between the lower opening 3 B as an air blowing port and the surface of the liquid A, using an AC fan produced by Sanyo Denki Co., Ltd. (model no. 109S075UL) as the air blower 4 .
[0067] It can be understood from the test results in Table 1 with variations in shape of the cylindrical body 3 , that a circular cylindrical body with the upper and lower openings 3 A and 3 B identical in diameter produces a more favorable mixing state than a cylindrical body with the upper and lower openings 3 A and 3 B decreased or increased in diameter downward. It can be understood from the test results in Table 2 with variations in length of the cylindrical body 3 , that the mixing state becomes more weakened with increase of length in the cylindrical body 3 . It can be understood from the test results in Table 3 with variations in liquid amount and liquid depth, that the mixing state becomes more weakened with increase of liquid amount and liquid depth.
[0000]
TABLE 1
Diameter of upper
115 mm
115 mm
115 mm
opening 3A
Diameter of lower
115 mm
90 mm
130 mm
opening 3B
Length of cylindrical
230 mm
230 mm
230 mm
body 3
Distance between
20 mm
20 mm
20 mm
lower opening 3B
and liquid surface
Mixing state
Liquid rotates
Decreased amount of
Preferred amount of air
favorably in
air is blown into
is blown into liquid, but
agitation and
liquid. Mixing
pressure of air blown into
mixing. Mixing
state is slightly
liquid is low. Mixing state
state is favorable.
insufficient.
is slightly insufficient.
[0000]
TABLE 2
Diameter of upper
115 mm
115 min
115 mm
opening 3A
Diameter of lower
115 mm
115 mm
115 mm
opening 3B
Length of cylindrical body 3
115 mm
230 mm
345 mm
Distance between
20 mm
20 mm
20 mm
lower opening 3B and
liquid surface
Mixing state
Liquid swells
Liquid rotates
Pressure of air blown
vigorously
favorably in
into liquid is low, and
in agitating and
agitation and
agitation and mixing are
mixing. Mixing
mixing. Mixing
weakened. Mixing
state is extremely
state is favorable.
state is slightly
favorable.
insufficient.
[0000]
TABLE 3
Diameter of upper
115 mm
115 mm
115 mm
opening 3A
Diameter of lower
115 mm
115 mm
115 mm
opening 3B
Length of cylindrical body 3
230 mm
230 mm
230 mm
Distance between lower
20 mm
20 mm
20 mm
opening 3B and liquid
surface
Liquid amount and
600 ml, 50 mm
400 ml, 30 min
200 ml, 20 mm
liquid depth
Mixing state
Liquid does not rotate
Liquid rotates,
Liquid is mixed
vigorously, and is mixed
well bubbles,
vigorously and
only by its upper
and spatters
bubbles entirely.
portion of about 1 to
around.
Mixing state
2 cm. Mixing state is
Mixing state is
is extremely
slightly insufficient.
favorable.
favorable.
[0068] According to the foregoing configuration of the air cleaning device 1 , the polluted air PA taken in from the air inlets 5 , 5 , . . . is pressurized by the air blower 4 so as to rotate and descend in a spiral manner, and is blown from the lower opening 3 B as an air blowing port toward the liquid surface, and collides with the liquid A and plunges into the container bottom, and then is agitated and mixed with an approximately total amount of the liquid A, as if the air is washed by the liquid. Therefore, the polluted air PA taken in from the air inlets 5 , 5 , is allowed to contact the liquid A with efficiency.
[0069] Accordingly, it is possible to remove pollutants such as dust, dirt, molds, ticks, pollens, and the like, in an efficient manner. In addition, if the liquid A is sterilizing fluid, it is also possible to kill and remove pollutants such as viruses, germs, and the like, in an efficient manner. If the liquid A is deodorant fluid, it is possible to eliminate bad odors of cigarette, formalin, and the like, in an efficient manner. If the liquid A is water, it is possible to remove dust from construction sites, plants, and the like, in an efficient manner.
[0070] In addition, the thus configured air cleaning device does not require a pump or a nozzle as described in Patent Document 1 or a pump or a reflector as described in Patent Document 2. Further, differently from the configuration described in Patent Document 3 with rotation of the guide fixed to the rotation shaft of the air blower and extended in the cleaning water, in this configuration, the cylindrical body 3 arranged under the air blower is not driven and the lower opening 3 B of the cylindrical body 3 as an air blowing port is separated from the surface of the liquid A, which eliminates the need for a large-capacity air blower or motor and prevents a structure from being complicated. This makes it possible to suppress increase in consumption of energy such as electrical power and manufacturing costs.
[0071] In addition, upper and lower metal draining meshes 8 and 9 as liquid removing means are arranged in the middle of a flow path in which the clean air CA having been purified by being agitated and mixed with the liquid A is raised on the outside of the cylindrical body 3 and is discharged from the air outlets 6 , 6 , . . . . Accordingly, the clean air CA is cleared of the liquid by the liquid removing means before being discharged from the air outlets 6 , 6 , . . . .
[0072] This makes it possible to suppress a content of the liquid in the discharged clean air CA and reduce decrease in amount of the liquid A in the container main body 2 , thereby to realize longer time intervals between tasks of refilling the liquid A.
[0073] In this arrangement, as shown by a partial longitudinal sectional view of FIG. 3 , a bar-like body 10 is provided so as to stand on the bottom of the liquid container 2 A as a liquid containing part for containing the liquid A and extend toward an approximate center of the cylindrical body 3 , thereby to decrease by the bar-like body 10 a passage section of the polluted air PA blown from the cylindrical body 3 and colliding with the liquid A. Accordingly, the polluted air PA rotating and descending in a spiral manner has an increased pressure to facilitate agitation and mixing of the polluted air PA and the liquid A, which allows the polluted air PA taken in from the air inlets 5 , 5 , . . . to contact the liquid A with higher efficiency.
[0074] In addition, as shown in the partial longitudinal sectional view of FIG. 4 , baffles 11 may be provided so as to project from the bottom of the liquid container 2 A. According to this configuration, agitation and mixing of the polluted air PA spirally rotating and descending and the liquid A are facilitated by the agitation facilitating effect of the baffles 11 , which allows the polluted air PA taken in from the air inlets 5 , 5 , . . . to contact the liquid A with higher efficiency.
[0075] The baffles 11 may be provided so as to project from portions of the side parts of the liquid container 2 A immersed in the liquid A.
[0076] Further, as shown in the partial longitudinal sectional view of FIG. 5 , an agitator 12 formed by a motor 13 and agitating blades 14 may be arranged on the bottom of the liquid container 2 A. According to this configuration, agitation and mixing of the polluted air PA spirally rotating and descending and the liquid A are facilitated by the agitation facilitating effect of the agitator 12 . This allows the polluted air PA taken in from the air inlets 5 , 5 , . . . to contact the liquid A with higher efficiency.
[0077] Moreover, as shown in the partial longitudinal sectional view of FIG. 6 , the air cleaning device may be configured in such a manner that: the liquid A is pumped up and pressurized, and is ejected upward from a nozzle 17 so as to collide with the reflector 18 ; the polluted air PA blown from the upper opening 3 A into the cylindrical body 3 so as to rotate and descend in a spiral manner, contacts the liquid A colliding with and scattered by the reflector 18 , in an internal mixing space B within the cylindrical body 3 ; a mixture of the polluted air PA falling from the cylindrical body 3 and the scattered liquid A, collides with a puddle of liquid in the container main body 2 and plunges into the bottom of the liquid container 2 A such that the polluted air PA is agitated and mixed with the liquid A; and the clean air CA having been agitated and mixed with the liquid A is raised on the outside of the cylindrical body 3 and discharged outside the container main body 2 .
[0078] Specifically, the air cleaning device 1 shown in FIG. 6 has a pump 15 for pumping up and pressurizing the liquid A sucked and fixed by suction cups 15 A, 15 A, . . . to the liquid container 2 A at a center of an upper surface of the bottom plate. The pump 15 has a discharge opening to which the upwardly directed nozzle 17 is attached directly or via a pipe 16 extending in a vertical direction. Accordingly, the liquid A is ejected as an upward jet flow from the nozzle 17 .
[0079] In addition, arranged above the nozzle 17 is the bowl-shaped reflector 18 opened downward and separated inward from the cylindrical body 3 , which collides with the liquid A ejected upward from the nozzle 17 .
[0080] Arranged under the reflector 18 is a bowl-shaped guide body 19 opened downward and separated inward from the cylindrical body 3 , which receives the liquid A colliding with and reflected on the reflector 18 , and guides the same outward.
[0081] In the configuration of FIG. 6 , the guide body 19 is attached to an upper end of the pipe 16 and the reflector 18 is fixed above the guide body 19 using bar-like support members 20 , 20 , . . . extending in a vertical direction. Alternatively, the reflector 18 may be supported by the cylindrical body 3 using bar-like support members extending in a horizontal direction, for example.
[0082] In addition, the reflector 18 and the guide body 19 under the same may not be formed in a bowl-like, downwardly-opened shape, but may be formed in the shape of a hemisphere, a partial hemisphere, a paraboloid, an umbrella, a flat plane, or the like, or may be formed in three dimensions, not two dimensions.
[0083] Further, the guide body 19 is not an essential component, and the reflector 18 may be singly provided. [ 0041 ]
[0084] According to the configuration of the air cleaning device 1 shown in FIG. 6 , the polluted air PA taken into the container main body 2 is pressurized by the air blower 4 , and rotates and descends in a spiral manner by rotation of the blades of the air blower 4 and contact with the inner wall surface of the cylindrical body 3 , and the liquid A as a jet flow ejected from the nozzle 17 is scattered by collision with the reflector 18 separated inward from the cylindrical body 3 , and the polluted air PA spirally rotating and descending and the liquid A colliding with and scattered by the reflector 18 are brought into contact within the cylindrical body 3 , and a mixture of the polluted air PA and the liquid A sharply falls in a bubble state.
[0085] The bubbled mixture collides with the liquid A contained in the lower part of the container 2 , and penetrates through the puddle of liquid and plunges into the bottom of the liquid containing part 2 A (container bottom). Accordingly, the entire liquid puddle is also strongly agitated and mixed in a spiral manner so as to bubble, swell, and increase in volume, as if the polluted air PA is washed by the liquid A. Therefore, the polluted air PA taken into the container main body 2 is allowed to contact the liquid A with extremely high efficiency.
[0086] Accordingly, it is possible to remove pollutants such as dust, dirt, molds, ticks, pollens, and the like, in a highly efficient manner. In addition, if the liquid A is sterilizing fluid, it is also possible to kill and remove pollutants such as viruses, germs, and the like, in a highly efficient manner. If the liquid A is deodorant fluid, it is possible to eliminate bad odors of cigarette, formalin, and the like, in a highly efficient manner. If the liquid A is water, it is possible to remove dust from construction sites, plants, and the like, in a highly efficient manner.
[0087] Besides, if the polluted air PA taken in from the air inlets 5 , 5 , . . . is hot wind, for example, the hot wind can be cooled down by airborne droplets of the liquid A colliding with and reflected on the reflector 18 and scattered in various directions. In addition, since the liquid A as a jet flow collides from below with the reflector 18 heated by transfer of forced convection heat from the hot wind, the hot wind can be cooled down via the reflector 18 by high-efficiency colliding jet cooling. Accordingly, in any of cases where the liquid A is sterilizing fluid or deodorant fluid or water, this configuration is suited for cooling hot air in working sites or the like at high temperatures.
[0088] Considering these cooling characteristics, the reflector 18 is preferably formed by metal with high thermal conductivity, such as copper or aluminum.
[0089] Moreover, differently from the configuration described in Patent Document 3 with rotation of the guide fixed to the rotation shaft of the air blower and extended in the cleaning water, in this configuration, the cylindrical body 3 arranged under the air blower 4 is not driven and the lower opening 3 B of the cylindrical body 3 as an air blowing port is separated from the surface of the liquid A, which eliminates the need for a large-capacity air blower or motor and prevents a structure from being complicated. This makes it possible to suppress increase in consumption of energy such as electrical power and manufacturing costs.
[0090] Further, when the guide body 19 is provided to receive the liquid A colliding with and reflected from the reflector 18 and guide the same outward, a part of the liquid A scattered by collision with the upper reflector 18 , further collides with the lower guide body 19 , and is guided outward and scattered by the guide body 19 . Accordingly, airborne droplets of the thus scattered liquid A are guided into the mixing space B inside the cylindrical body 3 . This increases the density of the airborne droplets of the liquid within the mixing space B, which allows the polluted air PA taken in from the outside to contact the liquid A with higher efficiency.
[0091] The air cleaning device 1 described above has one air blower 4 arranged above the cylindrical body 3 . Alternatively, a plurality of air blowers may be arranged above the cylindrical body 3 . For example, two, three, four, or more air blowers may be arranged in parallel in a horizontal direction (in a horizontal plane).
[0092] In addition, the air cleaning device 1 described above includes the container main body 2 that is an approximately circular cylinder in appearance. However, the appearance of the container main body 2 is not limited to an approximately circular cylinder but the container main body 2 may be formed in any other shape such as a polygonal column.
[0093] Further, the shapes of the air inlets 5 , 5 , . . . and the air outlets 6 , 6 , . . . are not limited to those in this embodiment, but these air inlets and outlets may be provided as round holes, slits, long holes, with any appropriate size.
[0094] Moreover, the air inlets may be formed in a top plate as an upper surface of the air blower assembly 2 B (container main body 2 ) or may be used in conjunction with the air inlets 5 , 5 , . . . in the side surface of the air blower assembly 2 B.
[0095] In addition, the connecting member 2 C may be eliminated between the liquid container 2 A and the air blower assembly 2 B. The range of vertical division of the container main body 2 and the division structure of the same are not limited to those in this embodiment.
REFERENCE SIGNS LIST
[0096] A Liquid (sterilizing fluid, deodorant fluid, or water)
[0097] B Mixing space
[0098] CA Clean air
[0099] PA Polluted air
[0100] Air cleaning device
[0101] Container main body
[0102] 2 A Liquid container (liquid containing part)
[0103] 2 B Air blower assembly
[0104] 2 C Connecting member
[0105] Cylindrical body
[0106] 3 A Upper opening (air blowing port)
[0107] 3 B Lower opening (air discharging port)
[0108] 4 Air blower
[0109] 5 Air inlet
[0110] 6 Air outlet
[0111] 7 Louver
[0112] 8 , 9 Metal mesh (liquid removing means)
[0113] 10 Bar-like body
[0114] 11 Baffle
[0115] 12 Agitator
[0116] 13 Motor
[0117] 14 Agitating blade
[0118] 15 Pump
[0119] 15 A Suction cup
[0120] 16 Pipe
[0121] 17 Nozzle
[0122] 18 Reflector
[0123] 19 Guide body
[0124] 20 Support member
[0125] 21 Power cord
[0126] 22 Power plug
[0127] 23 Switch | 4y
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RELATED APPLICATION
This application is a continuation-in-part of application Ser. No. 604,896 filed Apr. 27, 1984, now U.S. Pat. No. 4,608,011.
BACKGROUND OF THE INVENTION
The present invention relates in general to a candle apparatus. More particularly, the present invention is concerned with an improved functional and decorative lighting means that is adapted to have the appearance of a candle with its associated candle-like flame but in which the flame and associated lighting is produced from a liquid source which may be a petroleum or non-petroleum product.
It is an object of the present invention to provide an improved candle apparatus that is safe to operate, relatively easy to maintain and which provides a candle-like flame and appearance.
Another object of the present invention is to provide an improved candle apparatus in accordance with the preceding object, and in which the liquid container may be easily removed and/or replaced.
Still a further object of the present invention is to provide an improved candle apparatus in accordance with the preceding objects, and which is readily adaptable to being configured into different sizes and shapes, having in particular, a universal base construction.
Another object of the present invention is to provide an improved candle apparatus having a candle-like flame and furthermore characterised by candle-like illumination about the flame.
SUMMARY OF THE INVENTION
To accomplish the foregoing and other objects, features and advantages of the invention, there is provided a candle apparatus that comprises a base having means defining a base opening. The base opening is for receiving a canister. The canister contains the liquid that is to be burned. This liquid may be a petroleum product but is preferably a vegetable oil based product. The canister has a removable top cap with sealing means associated therewith. A wick or the like extends from the canister through the cap and it is the wick that is lighted to produce the candle-like flame. Over the canister and the base is fitted an external shell that substantially covers the canister and also extends about a platform on the base. The base may have associated therewith, some means by which the base and thus the entire candle apparatus can be supported from a larger base or other structure from which the candle apparatus is to be supported. The shell preferably has an upper peripheral flange in proximity to the flame for providing candle-like illumination.
BRIEF DESCRIPTION OF THE DRAWINGS
Numerous other objects, features and advantages of the invention should now become apparent upon a reading of the following detailed description taken in conjunction with the accompanying drawing, in which:
FIG. 1 is an exploded perspective view of the candle apparatus of the present invention;
FIG. 2 is a cross-sectional view taken through the candle apparatus of the present invention with the canister and shell in position in use; and
FIG. 3 is an enlarged view of the top of the candle apparatus illustrating a flame and associated rays interacting with the apparatus shell.
DETAILED DESCRIPTION
Reference is now made to the drawing which illustrates in FIG. 1 an exploded perspective view of a preferred embodiment of the candle apparatus of the present invention. FIG. 2 shows a cross-sectional view with all of the parts of the apparatus in their assembled position in use. FIG. 3 is an enlarged fragmentary view of the top of the candle apparatus illustrating the flame and associated light rays.
The apparatus of the present invention comprises a base 10 having extending upwardly therefrom, a platform 12 which in turn has extending upwardly therefrom, an annular wall 14 defining a base opening 16. Through the base 10 and integral platform 12, there is provided a centrally disposed passage 18 which is preferably countersunk as indicated at 20. This passageway may be for receiving a wood screw or the like.
The base 10 is constructed preferably of a plastic material and the passage 18 for receiving the wood screw may provide a means by which the base can be fastened to another member not shown herein. For example, the base 10 may be secured to a larger base member to provide additional stability to the candle apparatus.
As indicated in FIG. 2, in the cross-sectional view, it is preferred that the base 10 and platform 12 be substantially solid with the exception of the passageway 18. This provides for sufficient weight to the base member. In addition, weights may be provided in the base member to provide additional stability for the overall candle apparatus. However, for the most part, the provision of a solid plastic base and platform provides sufficient weight to provide good stability to the candle apparatus.
The candle apparatus of this invention also comprises a canister 24 which is of cylindrical construction with the outer diameter thereof dimensioned so as to snugly fit within the base opening 16 defined by the annular wall 14. This snug fit is illustrated in the cross-sectional view of FIG. 2. The bottom wall 26 of the canister rests upon the top wall 28 of the platform 12.
The canister 24 contains a liquid 30. This liquid 30 may be a petroleum product such as Nopar 15, but is preferably a vegetable oil base product.
The canister 24 is sealed at the top by means of a cap 32 which is fitted with an O-ring 34 which provides a tight seal between the cap 32 and the top periphery of the canister 24. It is noted that the cap 32 is also provided with a centrally disposed passage 36 through which extends the wick 40. FIG. 2 shows a small segment of the wick 40 extending outwardly of the passage 36. It is also preferred that the top of the cap 32 be arranged in a step configuration as noted in FIG. 2. One of the steps in the top of the cap 32 forms a shoulder 42 which is a limiting means relative to the outer shell 46.
As just indicated, the remaining portion of the candle apparatus comprises a shell 46 which is generally of cylindrical shape, totally open at the bottom and having an annular flange 48 at the top thereof directed inwardly. It is noted that the shell 46 is conveniently aligned with the canister and with the cap 32 by means of interaction of the flange 48 with the shoulder 42. This tends to position the components properly and, in particular, positions, the canister 24 in its proper vertical orientation.
The shell 46 at its bottom end rests upon the surface 50 of the base. As indicated previously, the fit between the canister and the annular wall 14 is snug. Also, there is preferably a relatively snug fit between the shell 46 and the outer surface of the annular wall 14 extending downwardly to the base 10.
It is noted in accordance with the unique candle apparatus of this invention that, in order to replace the canister 24 or in order to refill it, one simply has to remove the shell 46. When this is removed, then the canister 24 is readily accessible. The canister 24 may then be removed from the base opening 16 and then may be replaced or refilled.
For the purpose of refilling, the cap 32 is relatively easily removed and additional liquid can be added to the canister. The canister is then replaced in the base opening 16 and the shell 46 is then inserted over the canister and base. Once again, proper alignment is provided by the interaction at the top of the cap between the shoulder 42 defined in the cap and flange 48 that terminates at the annular wall 49 forming a centrally disposed hole in the top flange of the shell. The flange 48 actually provides a hole which is of slightly greater diameter than the diameter at the annular shoulder 42.
Reference is now made to FIG. 3 which shows the top of the candle apparatus enlarged to clearly illustrate dimensional and positional relationships in particular between the canister and shell. It is noted that in FIG. 3 the top of the wick 40 has been lighted and there is illustrated in FIG. 3 the flame F. Rays R are shown extending from the flame F and in particular as they extend toward and impinge upon the surface W of the flange 48.
To provide the proper type of candle-like illumination and glow, it is desired to have the flange 48 as the thickest part of the shell 46. This thickness of plastic material is instrumental in providing sufficient volume of plastic to create an illumination and glow at the flange 48. In this regard, note in FIG. 3 that the maximum thickness of the flange 48 as represented by the dimension t is greater than the thickness of the wall of the shell as represented by the dimension d. The dimension t may be on the order to twice the dimension d. The minimum thickness of the flange 48 at the centrally disposed hole may be on the same order of magnitude as the dimension d.
As indicated previously, FIG. 3 shows the rays R directed to the surface W of the flange 48. It is noted that this surface is at an angle to the horizontal preferably on the order of at least 20°. By slanting the wall W the rays R are intercepted at the wall in a more orthogonal manner thus enhancing illumination not only directly at the flame F but also providing illumination or glow at the flange 48.
It is also noted in FIG. 3 that the top of the cap 32 in particular at the shoulder 42 interlocks with the hole in the shell. As such it is preferred that the top of the shell be substantially co-terminous with the top of the cap 32 of the canister. This is advantageous in providing proper illumination and also in proper candle-like appearance. It is also preferred to have the main surface S of the cap 32 disposed at a vertical height substantially mid way of the height of the hole in the shell. The point P on the flange of the shell is preferably above the surface S.
The entire product of the present invention is made out of a very rigid and durable plastic. The preferred plastic is ABS plastic. Such a plastic product is not deteriorated by petroleum products. The cap 32 of the liquid container may be of phenolic.
Having described one embodiment of the present invention, it should now be apparent to those skilled in the art that numerous other embodiments are contemplated as falling within the scope of this invention. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device and method for generating a laser light show, and in particular, a device and method for generating a laser light show having enhanced holographic effects.
2. Description of the Related Art
As the cost and reliability of laser light sources has decreased and increased, respectively, their applications have become increasingly varied and common. One application growing increasingly popular is in the field of entertainment. Laser light sources are being used to create laser light shows, both indoors and outdoors. Indeed, modern concert tours can often be considered disappointing unless a laser light show is included.
Devices for generating laser light shows have suffered and continue to suffer from a number of drawbacks. One drawback is that the devices tend to be rather large and bulky, and therefore difficult to transport. The laser light sources themselves tend to be rather large and bulky, and a series of beam reflectors, e.g. mirrors, and converging means, e.g. lenses, are required to draw the multiple colored laser beams (e.g. red, yellow, green) into close mutual proximity to facilitate their manipulation.
Devices for generating laser light shows typically fail to take advantage of the holography generating capabilities of laser light. Rather, the devices typically will simply use the laser light sources to project brilliantly colored light patterns upon some surface.
Accordingly, a need exists for a laser light show device having an improved design to reduce its size and complexity, and means for advantageously using the laser light to create and enhance holographic imagery.
SUMMARY OF THE INVENTION
A laser light show device in accordance with the present invention has an improved design and layout which reduces its mechanical size and complexity. The present invention advantageously uses the holography generating capability of laser light to produce projected images having enhanced holographic effects. The object image is projected onto a background having up to three types of background images. One type of background image is the projection of a reference beam created by reflecting a laser light beam off a rotating wobbler plate and diffracting the wobbled light beam through a spherical crystal lens.
A second background image is generated by diffracting a laser light beam through a slowly rotating cylindrical amorphic dipolyhedral lens. A third background image is generated by diffracting a laser light beam through two diffraction gratings, wherein one diffraction grating is moving relative to the other.
The present invention uses a novel laser light beam shutter to effectively turn on and off, e.g. modulate, the laser light beam. The invention's shutter consists of a substantially opaque rod mounted and driven to rotate about its longitudinal axis. The rod has a substantially cylindrical hole perpendicular to its longitudinal axis. As the rod spins, the hole becomes alternately concentric and non-concentric with the laser light beam, thereby allowing the laser light beam to pass freely or become effectively blocked.
The present invention provides a means for projecting a suspended holographic image. Multiple laser light beams modulated by object image information are projected equiangularly about the equator of a substantially spherical body having a white periphery with a matte finish. The spherical body is centrally located within one of two opposing parabolic reflectors. The second parabolic reflector has a centrally located aperture through which a holographic image is projected. The holographic image converges just beyond the aperture and just outside the paraboloid formed by the opposing parabolic reflectors.
These and other objects, features and advantages of the present invention will be readily understood upon consideration of the following detailed description of the invention and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Throughout the figures similar elements are indicated by like numerals.
FIG. 1A is a block diagram of a laser light show device in accordance with the present invention.
FIG. 1B is a side view of the invention illustrating the mechanical mounting of the laser assemblies.
FIG. 2 illustrates a laser light shutter assembly in accordance with the present invention.
FIG. 3A is a block diagram of the invention's reference and object beam generator.
FIG. 3B illustrates the double hemispherical diffraction produced by a spherical lens in accordance with the present invention.
FIGS. 4A-4B illustrate the invention's amorphic dipolyhedral lens assembly.
FIG. 5 illustrates the invention's diffraction gratings assembly.
FIG. 6 illustrates the invention's holographic suspension projector.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1A, a laser light show device 10 in accordance with the present invention consists of the following elements, coupled as shown: multiple colored laser assemblies 12a-12c; dielectric mirrors 14a-14c; multiple beam splitters 16a-16c, 18a-18c; multiple reference and object beam generator assemblies 20a-20c; an object information source 22; an amorphic dipolyhedral lens assembly 24; and a diffraction gratings assembly 26.
As shown in FIG. 1A, three laser light assemblies 12a-12c, preferably having red, yellow and green laser light sources, are used in a preferred embodiment of the present invention. However, it will be appreciated that any number or colors of laser light sources can be used in accordance with the present invention as described below.
Each laser assembly 12a-12c emits an incident laser beam 28a-28c which is reflected off a dielectric mirror 14a-14c. The reflected laser beams 30a-30c pass through the first set of beam splitters 16a-16c, producing secondary incident laser beams 32a-32c and secondary reflected laser beams 34a-34c. As described more fully below, the secondary incident laser beams 32a-32c are diffracted through the amorphic dipolyhedral lens assembly 24 prior to projection.
The secondary reflected laser beams 34a-34c are passed through the second set of beam splitters 18a-18c, producing tertiary incident laser beams 36a-36c and tertiary reflected laser beams 38a-38c. As described more fully below, the tertiary reflected laser beams 38a-38c are passed through the diffraction gratings assembly 26 prior to projection.
The beam splitters 16a-16c, 18a-18c can be selected according to subjective desires regarding the relative beam intensities of the resulting laser beams 32a-32c, 34a-34c , 36a-36c, 38a-38c. For example, the first beam splitters 16a-16c can be selected to allow approximately 30% of the intensities of the reflected laser beams 30a-30c to pass through as the secondary incident laser beams 32a-32c, with the remaining intensities reflecting as he secondary reflected laser beams 34a-34c.
The tertiary incident laser beams 36a-36c are coupled into the reference and object beam generators 20a-20c for processing prior to projection of the reference 78a-78c and object 68a-68c beams. As explained more fully below, object image information signals 40a-40c from the object image information source 22 are also coupled into the reference and object beam generators 20a-20c for use in processing the tertiary incident laser beams 36a-36c prior to projection of the reference 78a-78c and object 68a-68c beams.
The object image information signals 40a-40c, supplied by the object image information source 22, can contain virtually any type of image data. For example, the object image information signals 40a-40c can represent graphics data, such as that used in an engineering workstation, a video game or medical imaging applications.
As seen in FIG. 1A, the dielectric mirrors 14a-14c are staggered horizontally so that the incident laser beams 28a-28c produce reflected laser beams 30a-30c which are similarly horizontally staggered. By appropriately staggering the dielectric mirrors 14a-14c horizontally, the reflected laser beams 30a-30c can be proximally located adjacent to one another at distances on the order of several millimeters. Thus, the horizontal spacing of the reflected laser beams 30a-30c can be substantially less than the horizontal spacing of the incident laser beams 28a-28c, which is dictated by the physical dimensions of the laser assemblies 12a-12c (typically on the order of several inches).
As shown in FIG. 1B, the laser assemblies 12a-12c can be mounted along an inclined plane 42. By mounting the laser assemblies 12a-12c in this fashion, the vertical spacing of the reflected laser beams 30a-30c can also be established to be on the order of several millimeters. Just as with the horizontal spacing constraints imposed by the physical sizes of the laser assemblies 12a-12c, the vertical spacing would otherwise be substantially greater.
Therefore, by appropriately staggering the dielectric mirrors 14a-14c horizontally, and mounting the laser assemblies 12a-12c along a properly inclined plane 42, the reflected laser beams 30a-30c can be proximally located adjacent one another as desired.
Referring to FIG. 2, each laser assembly 12 contains a laser light source 44, which produces an original laser beam 46, and a shutter 48, which is driven by a shutter motor 50 through a coupling shaft 52. As described further below, the shutter motor 50 is controlled by a shutter control signal 54. The original laser beam 46 produced by the laser light source 44 is modulated by the shutter 48 to produce the incident laser beam 28. This modulation is done by rotating the shutter 48. As the shutter 48 rotates, a hole 56 in the shutter, perpendicular to the axis of rotation, alternates between being aligned and non-aligned with the original laser beam 46. When the hole 56 is in alignment with the original laser beam 46, the incident laser beam 28 is produced. This means of modulating the original laser beam 46 produces an incident laser beam 28 which can be effectively turned on and off very quickly.
Referring to FIG. 3A, the reference and object beam generator assembly 20 consists of the following elements, coupled as shown: a beam splitter 58; an x-y scanner assembly 60; a wobbler plate assembly 62; and a spherical lens 64.
The tertiary incident laser beam 36 enters the reference and object beam generator assembly 20 and passes through the beam splitter 58. The reflected beam 66 is reflected through the X-Y scanner assembly 60 to produce the object beam 68 for projection. The X-Y scanner assembly 60 is driven by the object image information signal 40, appropriately scanning, i.e. deflecting, the reflected beam 66 in the X- and Y-directions to product the object beam 68 for projection.
The non-reflected beam 70 exiting the beam splitter 58 is reflected off a wobbler plate assembly 62. The dielectric mirror 72 of the wobbler plate assembly 62 rotates in a non-planar manner. The non-reflected beam 70 strikes the wobbling mirror 72 slightly off center, thereby striking a wobbling mirror surface. This produces a wobbling reflected beam 74 which spins conically about a central axis.
The wobbling beam 74 is passed through the spherical lens 64 to produce a singly hemispherically diffracted beam 76 and then a doubly hemispherically diffracted beam 78. As shown in FIGS. 3A and 3B, the single and double diffraction patterns are hemispherical in the sense that the diffraction patterns extend in both the vertical and horizontal directions.
In a preferred embodiment, the spherical lens 64 is constructed of substantially optically pure quartz crystal. The latticed structure of the quartz crystal enhances the regularity and uniformity of the diffraction properties of the spherical lens 64. This results in more uniform hemispherically diffracted beams 76, 78.
Both the object image beam 68 and reference image beam 78 are projected together. When so projected, the reference image beam 78 serves as a dim background providing a sensation of parallax, while the object image beam 68 provides the subject image. The overall holographic effect can be enhanced by selectively synchronizing the wobbler control signal 80 with the shutter control signal 54.
By selectively controlling the rotational speed of the wobbling dielectric mirror 72, relative to the rotational speed of the shutter 48, the relative wobbling circular motion of the wobbling beam 74, relative to the on-off modulation of the incident laser beam 28, and therefore the non-reflected beam 70, produces a reference image beam 78 having variable stasis. By varying the relative rotational speeds of the wobbling mirror 72 and shutter 48, the reference beam 78 can be selectively provided with negative stasis, wherein the reference beam pattern appears to rotate counterclockwise, or positive stasis, wherein the reference beam pattern tends to rotate clockwise. This produces an overall effect of making the projected object image appear to recede or approach the viewer.
Another X-Y scanner (not shown) can be used in line with the non-reflected beam 70. By "averaging" the object image information signal 40, the X-Y, i.e. planar, center of the object image can be represented. Such an "averaged" object image information signal can then be used to drive the X-Y scanner for the non-reflected beam 70. This would produce a wobbling beam 74, and therefore a reference beam 78, which projects a reference image which is substantially centered about the projected object image.
Further projected background image information can be provided by using the amorphic dipolyhedral lens assembly 24, as shown in FIGS. 4A-4B. The lens assembly 24 consists of an amorphic dipolyhedral lens 82 rotated by a motor 84 via a shaft 86. The rotational speed of the lens 82 can be set at any speed subjectively deemed desirable, based upon the visual effect produced. The secondary incident laser beam 32 enters the lens 82, producing a singly vertically diffracted beam 88. The singly vertically diffracted beam 88, exits the lens 82, producing a doubly vertically diffracted beam 90. FIG. 4B illustrates this vertical diffraction in more detail. The amorphic dipolyhedral lens 82 is a hollow cylinder constructed of glass with irregular longitudinal protrusions, e.g. knurls, about its periphery. In a preferred embodiment, glass is preferred over crystal to take advantage of the non-latticed structure of glass. This non-latticed structure, in conjunction with the longitudinal outer surface irregularities, enhance the amorphic diffraction properties of the lens 82. An experimental version of the lens 82 was constructed from an empty Finlandia® vodka bottle.
Still further background image information can be projected to further enhance the holographic effect of the laser light show device in accordance with the present invention. Such additional background image information can be provided with the diffraction gratings assembly 26. Referring to FIG. 5, the tertiary reflected laser beam 38 first passes through a fixed diffraction grating 92. This produces a singly diffracted beam 100, which is passed through a rotating diffraction grating 94, producing a doubly diffracted beam 102. The rotating diffraction grating 94 is rotated by a motor 96 via a shaft 98.
In an alternative embodiment, the first diffraction grating 92 can also be rotated, either in a direction counter to that of the rotational direction of the first rotating diffraction grating 94, or in the same direction but at a different speed. This double diffraction of the laser beam 38 through multiple diffraction gratings moving relative to one another produces a background image beam 102 which imparts a further sensation of motion which enhances the holographic effect of the displayed object image.
As stated above, the background and object image information need not be projected onto a surface, but can instead be projected to produce a suspended holographic image. This can be accomplished by using a holographic suspension projector as shown in FIG. 6.
Top and bottom opposing concave reflective saucers 104, 106, preferably parabolic reflectors, are used. Centrally located within the bottom reflector 106, is a substantially spherical image reflector 108 The image reflector 108 should have a substantially white surface with a matte, i.e. not glossy, finish. For example, a white plastic material can be used, however, a white ceramic material will produce a better image.
Centrally disposed within the top reflector 104 is an aperture 110. Object image information modulated onto multiple laser beams 112a-112c is projected substantially equiangularly about the equator of and onto the image reflector 108. The multiple images thereby produced on the image reflector 108 are reflected within the parabolic reflectors 104, 106 and converge at a point 114 just beyond the aperture 110. This converging image information produces a holographic image which appears to be suspended just above the aperture 110.
The object image information modulating each of the laser beams 112a-112c can be identical, thereby producing a suspended holographic image which appears substantially identically regardless of the horizontal viewing perspective. Alternatively, the object image information modulating each of the laser beams 112a-112c can represent different views of the same subject, thereby producing a suspended holographic image which appears to be three-dimensional as the horizontal viewing perspective changes.
It should be understood that various alternatives to the embodiments of the present invention described herein can be employed in practicing the present invention. It is intended that the following claims define the scope of the present invention and that structures and methods within the scope of these claims and their equivalents be covered thereby. | 4y
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This is a division of application Ser. No. 07/896,036, filed Jun. 9, 1992 now U.S. Pat. No. 5,211,682.
BACKGROUND OF THE INVENTION
This invention relates to a fuel feed apparatus which feeds fuel to an internal combustion engine, and more particularly, to a fuel feed apparatus which is capable of promoting atomization of the fuel by supplying assist air to a fuel injection valve disposed in an intake passage of the internal combustion engine and serving to inject the fuel.
Heretofore, an internal combustion engine of the type that one cylinder is provided with a plurality of intake valves has been put into practice widely.
Further, there has been well known a fuel injection valve of the type that a plurality of fuel injection nozzles are directed to a plurality of intake valves individually so as to inject the fuel toward the intake valves to thereby reduce fuel adhesion to the intake passage and hence improve the performance of the engine.
In addition, there has been well known such a technique named air assist that air is injected from the fuel injection valve together with the fuel. For example, as disclosed in Japanese Utility Model Examined Publication No. 2-16057, it has been known as well that assist air is supplied to a fuel injection valve having two fuel injection nozzles so as to atomize the fuel sprayed for two intake valves by the assist air. Moreover, in the fuel injection valve disclosed in Japanese Patent Unexamined Publication No. 64=24161 as well, assist air is supplied to the fuel injection valve having two fuel nozzles so as to atomize the fuel sprayed for two intake valves by the assist air. According to these air assist techniques, since the fuel can be atomized by the assist air, combustion can be improved and hence the constituents of exhaust gas can be improved.
Still furthermore, Japanese Patent Unexamined Publication No. 63-314363 discloses a technique that a sleeve to be provided at the tip end of the fuel injection valve is divided into two parts so as to form assist air passages in abutting surfaces of the two sleeve members.
According to the conventional air assist technique described above, the assist air is supplied to two sprays of fuel directed to two intake valves individually so as to form two separate sprays of fuel atomized by the assist air. However, in case of atomizing the fuel due to air assist, since the assist air is made to collide against the sprayed fuel, as the particle size of the air-assisted sprayed fuel becomes smaller to promote the atomization, the spray cone angle of the air-assisted sprayed fuel becomes larger. For this reason, if it is intended to form two air-assisted sprays as in the conventional air assist technique, it is necessary to make small the spray cone angle of each spray, resulting in the problem that the atomization cannot be performed satisfactorily.
In consequence, according to the conventional air assist technique, it is impossible to perform the atomization satisfactorily, resulting in the problem that the fuel adheres to the intake passage or the intake valves.
Particularly when it is required to inject a large amount of fuel such as when the internal combustion engine is operated in high-load condition or operated at low temperatures immediately after the engine is started, the fuel injection time of the fuel injection valve is prolonged in order to increase the fuel injection amount so that the fuel injection is started before the intake valves are opened in some cases. If the fuel is injected at the time when the intake air flows slow, such as before the intake valves are opened, according to the conventional air assist technique, a large amount of fuel adheres to the intake passages or the intake valves, thereby making it impossible to improve the combustion in the cylinder sufficiently and hence to improve the constituents of the exhaust gas satisfactorily.
Further, according to the conventional air assist technique, forming of the assist air passages requires drilling of elongated holes, resulting in the problem that the manufacturing cost is increased. To cope with this, it is considered to form the assist air passages between the two members. However, in case that the two members are plasticized, there is a possibility that, in joining the two members to each other, the assist air passages are deformed due to crushing of the bonding agent, resin or the like to thereby cause the clogging of the assist air passages or the lack of assist air flow.
OBJECT AND SUMMARY OF THE INVENTION
An object of the present invention is to provide a fuel feed apparatus which is capable of actualizing an injection mode which forms sprays directed toward a plurality of intake valves and another injection mode which forms a single spray having a wide spray cone angle, while overcoming the above-described problems of the conventional air assist technique.
Another object of the present invention is to provide a method for manufacturing a fuel feed apparatus which is capable of forming assist air passages using a resin material without deforming the assist air passages.
According to the present invention, at the tip end of a fuel injection valve are provided a passage member which is formed with a fuel passage, assist air passages and a guide portion, and an interrupter means serving to interrupt the supply of assist air. The fuel passage is so formed as to direct the fuel injected from the fuel injection valve toward a plurality of intake valves of an internal combustion engine, while the assist air passages are so formed as to cross the fuel injected from the fuel passage. For this reason, as the supply of the assist air is cut off by the interrupter means, the fuel injected from the fuel injection valve is passed through the fuel passage so as to be injected toward the respective intake valves, thereby forming sprays directed toward a plurality of intake valves of the internal combustion engine. On the other hand, as the interrupter means allows the assist air to be supplied, the fuel issued from the fuel passage is stirred and atomized due to collision with the assist air so as to become a single spray. At this time, the spray cone angle becomes large due to collision with the assist air, and however, it is regulated by the guide portion, thereby obtaining a spray of the desired spray cone angle. In this way, according to the present invention, it is possible to actualize an injection mode which forms sprays directed toward a plurality of intake valves and another injection mode which forms a single spray having a wide spray cone angle.
Further, the fuel passage can comprise a plurality of fuel passages directed to the plurality of intake valves. This makes is possible to form a plurality of separate sprays directed toward the respective intake valves.
Moreover, the assist air passages are each formed to extend inwardly and inclinedly from the outside of the fuel passage toward the direction of fuel injection so that the spray cone angle can be prevented from becoming too large when the assist air is supplied.
Still furthermore, the assist air passages are so opened as to surround the opening of the fuel passage so that the spray cone angle can be prevented from becoming too large when the assist air is supplied.
According to the manufacturing method of the present invention, an inner member and an outer member which are formed with a fuel passage and assist air passages are formed using a resin material and, moreover, they are joined to each other to be unified. At this time, by inserting the inner member into the outer member through one of openings thereof, the assist air passages are formed which extend from the penetrating holes passing through between the inner member and the outer member to reach around the fuel passage opened in the end surface of the inner member. Furthermore, the inner member and the outer member are joined to each other at a joining position nearer to one of the openings than the penetrating holes. Therefore, since no assist air passage is formed in the joining position, the assist air passages can be prevented from being deformed or clogged at the time of joining.
In addition, on the occasion of welding the inner member and the outer member to each other by melting part of the both members as the inner member is inserted into the outer member, since the inner member is formed on the outer periphery thereof with a guide portion which is to be inserted as being kept in contact with the inner peripheral wall surface of the outer member, it is possible to weld the both members to each other favorably due to melting of a melting portion and a stepped portion while maintaining a gap between the inner member and the outer member.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a structural view showing a schematic structure of a first embodiment of the present invention;
FIG. 2 is a sectional view of an air-assist fuel injection valve;
FIG. 3 is a schematic view showing a form of atomization of fuel issued from the air-assist fuel injection valve;
FIG. 4 is a schematic view showing another form of atomization of the fuel issued from the air-assist fuel injection valve;
FIG. 5 is a structural view showing a schematic structure of a second embodiment of the present invention;
FIG. 6 is a flow chart showing the operation of a control unit;
FIG. 7 is a sectional view of a fuel injection valve according to a third embodiment of the present invention;
FIG. 8 is a side view of a sleeve;
FIG. 9 is a view as viewed from an arrow mark direction A of FIG. 8;
FIG. 10 is a sectional view taken along the line I-O-I of FIG. 9;
FIG. 11 is a view as viewed from an arrow mark direction B of FIG. 10;
FIG. 12 is a side view showing the shape of a sleeve nozzle according to the third embodiment of the present invention before it is melted;
FIG. 13 is a view as viewed from an arrow mark direction C of FIG. 12;
FIG. 14 is a sectional view taken along the line II-O-II of FIG. 13;
FIG. 15 is a sectional view taken along the line III--III of FIG. 14;
FIG. 16 is a sectional view showing a modification of the groove shape of FIG. 15;
FIG. 17 is a side view of a cover nozzle according to the third embodiment of the present invention;
FIG. 18 is a view as viewed from an arrow mark direction D of FIG. 17;
FIG. 19 is a sectional view taken along the line IV-O-IV of FIG. 18;
FIG. 20 is a sectional view of a sleeve according to a fourth embodiment of the present invention;
FIG. 21 is a sectional view of a fuel injection valve according to a fifth embodiment of the present invention; and
FIG. 22 is a sectional view of a fuel injection valve according to a sixth embodiment of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Preferred embodiments of the present invention will be described below.
FIG. 1 is a structural view showing a schematic structure of a first embodiment.
In an internal combustion engine 1, each cylinder is provided with two intake valves 2 and two exhaust valves 3. In FIG. 1, one of the intake valves 2 and one of the exhaust valves 3 alone are illustrated. An intake passage 4 is connected to the intake valve 2 of the internal combustion engine, and a throttle valve 5 serving to regulate the intake air flow is disposed in the intake passage 4. Further, upstream of the intake passage 4 are provided an intake measuring device and an air cleaner which are not shown.
An air-assist fuel injection valve 6 is disposed between the throttle valve 5 and the intake valve 2 in the intake passage 4. The air-assist fuel injection valve 6 comprises a fuel injection nozzle through which the fuel is injected and an assist air jet nozzle through which assist air is jetted toward the fuel injected from the fuel injection nozzle. Further, the air-assist fuel injection valve 6 is fixed in the intake passage 4 so as to make the fuel injection nozzle thereof point at the intake valve 2. The air-assist fuel injection valve 6 is supplied with the fuel from a fuel tank which is not shown, which fuel is pressurized by a fuel pump and regulated at a fixed pressure by a pressure regulating valve, while a control pulse generated by a control unit which is not shown and having a pulse duration corresponding to the amount of fuel to be injected to sent to the air-assist fuel injection valve 6. In addition, the assist air is introduced to the air-assist fuel injection valve 6 through an assist air passage 7 communicated with the intake passage 4 upstream of the throttle valve 5.
FIG. 2 is a sectional view showing the structure of the air-assist fuel injection valve 6.
The air-assist fuel injection valve 6 comprises a fuel valve section 600. A popular fuel injection valve is used as this fuel valve section 600.
The fuel valve section 600 has a valve housing 602 which is formed with a fuel injection nozzle 601 at the tip end thereof. A valve needle 603 serving to open and close the fuel injection nozzle 601 is received in the valve housing 602. The valve housing 602 is fixed to a housing 604. A magnet coil 605 is disposed in the housing 604 and energized by a control circuit which is not shown through a connector 606. The valve needle 603 is provided with an armature 607 so that the valve needle 603 is moved by the electromagnetic force produced due to energization of the magnet coil 605. A stator 608 is fixed to the housing 604 and the fuel is supplied to the upper end portion, in this drawing, of the stator 608 from the fuel pump which is not shown. As the magnet coil 605 is energized and, hence, the valve needle 603 is moved, the fuel injection nozzle 601 is opened so that the fuel is allowed to pass through the inside of the stator 608, the inside of the armature 607 and, further, between the valve needle 603 and the valve housing 602 until it is injected from the fuel injection nozzle 601.
The fuel valve section 600 is inserted in a case 610 which serves to form assist air passage. The case 610 is equipped with a pipe 611 so that the assist air is introduced from the assist air passage 7 into the case 610 through the pipe 611. Within the case 610, a sleeve 620 and a socket 630 are disposed at the tip end portion of the valve housing 602 of the fuel valve section 600. By inserting and fixing the fuel valve section 600 in the case 610, the sleeve 620 and the socket 630 are fixedly held between the fuel valve section 600 and the case 610.
The sleeve 620 is formed with two fuel passages 621 and 622 through which the fuel injected from the fuel injection nozzle 601 is made to pass. A partition wall 623 is formed between these two fuel passages 621, 622 so as to divide into two parts the fuel injected from the fuel injection nozzle 601. Each of the two fuel passages 621, 622 is conical in shape so that the sectional area thereof is reduced as going toward the downstream of the spray of the fuel.
Further, the sleeve 620 is formed with two assist air passages 624 and 625 through which the assist air is made to pass. The upstream ends of the assist air passages 624, 625 are opened into the interior space of the case 610, while the downstream ends of the assist air passages 624, 625 are opened into the downstream parts of the fuel passages 621, 622 of the sleeve 620, respectively. The axis of the assist air passage 624 crosses the axis of the fuel passage 621, while the axis of the assist air passage 625 crosses the axis of the fuel passage 622. Further, the axes of the two assist air passages 624, 625 cross each other at a point downstream of the partition wall 623.
The socket 630 is formed with a conical passage 631 which serves to regulate the spray cone angle of the fuel.
The air-assist fuel injection valve 6 shown in FIG. 2 is fixed in the intake passage 4 of the internal combustion engine so that the axes of the two fuel passages 621, 622 are directed respectively to the intake valves of the internal combustion engine and the two sprays of fuel injected through the two fuel passages 621, 622 are directed respectively to the intake valves.
FIGS. 3 and 4 are schematic views each showing the form of spraying of the fuel from the fuel injection valve to the intake valves of the internal combustion engine.
The internal combustion engine is equipped with two intake valves 2a and 2b. The intake passage 4 is branched off into two intake ports 4a and 4b which are communicated with the two intake valves 2a and 2b, respectively. An intermediate wall 4c is formed between the two intake ports 4a, 4b. It is noted that, in FIGS. 3 and 4, the form of spraying from the fuel injection valve 6 is shown as the hatched section and the spray cone angle is indicated by α or β.
Next, operation of the above-described embodiment will be described.
In this embodiment, when the throttle valve 5 is opened, the differential pressure of the assist air passage 7 is caused to disappear to cut the assist air, resulting in that the injection of the assist air from the assist air passages 624, 625 is stopped. As the magnet coil 605 of the fuel valve section 600 is energized while the throttle valve 5 is being opened, the fuel is injected from the fuel injection nozzle 601. The fuel injected from the fuel injection nozzle 601 is separated into the two fuel passages 621, 622. The fuel passed through the two fuel passages 621, 622 becomes two sprays of fuel the spray cone angle of which is narrow as indicated by 60 in FIG. 3. These sprays of fuel each having the narrow spray cone angle α are made to pass through the passage 631 and then go toward the two intake valves 2a, 2b, respectively.
In consequence, fuel adhesion to the inside of the intake passage 4 can be prevented when the engine is operated in the high rotational speed and high load condition, that is, when the throttle valve 5 is opened, so that it is possible to supply the fuel to the combustion chamber with reliability, resulting in that it is possible to improve the transient response characteristic of the engine, particularly the transient response characteristic obtained when heavy gasoline is used.
As the throttle valve 5 is closed, the differential pressure arises in the assist air passage 7 so as to allow the assist air to be supplied into the case 610, resulting in that the assist air is jetted through the assist air passages 624, 625. As the magnet coil 605 of the fuel valve section 600 is energized when the throttle valve 5 is closed, the fuel is injected from the fuel injection nozzle 601. The fuel injected from the fuel injection nozzle 601 is separated into the two fuel passages 621, 622. Since the assist air is introduced to the downstream parts of the fuel passages 621, 622, the fuel passed through the two fuel passages 621, 622 collides with the assist air so as to be disposed. At this time, dispersion of the sprayed fuel is regulated by the passage 631 formed in the socket 630, and however, it becomes a single spray of fuel having a wide spray cone angle β as shown in FIG. 4.
In consequence, atomization of fuel can be promoted when the engine is operated in the low rotational speed and low load-condition, that is, when the throttle valve 5 is closed, so that it is possible to supply the mixture of high quality, with the result that it is possible to reduce the emission and the change of combustion as well as to improve the transient response characteristic. Particularly in the case that, since a large quantity of fuel is injected when the temperature of the internal combustion engine is low, the magnet coil 605 is energized for a long time and the injection is started before the rising of air stream in the seat portions of the intake valves 2a, 2b, fuel adhesion to the intake pipe can be reduced and hence the fuel can be supplied to the combustion chamber with reliability owing to the large spray cone angle of the fuel and the promotion of the atomization.
As described above, according to this embodiment, it is possible to inject the fuel in accordance with the operating condition of the internal combustion engine and reduce the fuel adhesion to the intake passage caused at the time of increasing the amount of fuel in the case that the fuel is injected toward the intake valves, resulting in that it is possible to reduce the emission and the change of combustion as well as to improve the transient response characteristic of the internal combustion engine.
Next, description will be given of a second embodiment of the present invention with reference to FIGS. 5 and 6. FIG. 5 is a structural view showing a schematic structure of the second embodiment.
The assist air passage 7 is provided with a control valve 8 which serves to open and close this passage. The control valve 8 serves to open and close the assist air passage 7 in accordance with a signal from the control unit 9. The control unit 9 receives a signal from an operating condition detecting means 10 which serves to detect the operating condition of the internal combustion engine 1 and serves to control the control valve 8 in accordance with this operating condition. In this embodiment, it is designed that the operating condition detecting means 10 detects the low temperature condition of the internal combustion engine 1 from the cooling water temperature of the internal combustion engine.
The second embodiment has the same construction as that of the first embodiment except the above-described control valve 8 disposed in the assist air passage 7.
FIG. 6 is a flow chart showing the operation of the control unit 9 of the second embodiment.
At step 101, the cooling water temperature is received from the operating condition detecting means 10 as the operating condition of the internal combustion engine. At step 102, it is judged whether or not the cooling water temperature is the temperature representative of the low temperature condition of the internal combustion engine. If it is judged to be in the low temperature condition, the operation proceeds to the next step as indicated by an arrow mark YES. While if it is judged not to be in the low temperature condition, the operation proceeds to the next step as indicated by an arrow mark NO. At step 103, the control valve 8 is opened, while at step 104, the control valve 8 is closed.
According to this embodiment, only when the internal combustion engine is in the low temperature condition, the assist air is supplied and the atomization of the fuel is promoted. It is therefore possible to reduce the emission and the change of combustion as well as to improve the transient response characteristic of the internal combustion engine.
Although the supply of the assist air is interrupted in accordance with the cooling water temperature of the engine in the above second embodiment, it is possible to interrupt the supply of the assist air in accordance with the operating condition of the internal combustion engine such as the gear changing operation of the transmission, for example. Further, it is also possible that, by linking to a variable intake device which varies the intake valve operating timing of the internal combustion engine, the assist air is supplied only in the case that the timing at which the intake valve is opened is delayed so as to cause the fuel injection to start before the intake valve is opened, thereby promoting the atomization of the fuel.
Next, a third embodiment of the present invention will be described. Although the aforesaid first embodiment employs the air-assist fuel injection valve of the structure of FIG. 2, the third embodiment employs an air-assist fuel injection valve shown in FIGS. 7 to 19 in place of the air-assist fuel injection valve of FIG. 2. It is noted that the air-assist fuel injection valve of this embodiment is fixed in the intake passage of the internal combustion engine in the same manner as the first embodiment.
As shown in FIG. 7, an electromagnetic type fuel injection valve 701 is fitted in a delivery pipe 702 which serves to supply the fuel to the cylinders of the internal combustion engine. A housing 703 of the fuel injection valve 701 is formed in the shape of a stepped cylinder and a magnet coil 705 wound on a spool 704 is disposed in the large diameter portion of the housing 703. A cylindrical iron core 706 extends through the spool 704 from above and an adjusting pipe 707 is disposed within the iron core 706 so as to be axially slidable.
A nozzle body 710 is lap fixed in the small diameter portion of the housing 703 through a spacer 709 and an injection nozzle 712 is formed in a downward projected end surface of the nozzle body 710. A needle valve 714 is disposed in the nozzle body 710 from above so as to be slidable. A pintle 716 is formed at the tip end of the needle valve 714, which pintle 716 penetrates through the injection nozzle 712 leaving a gap from the inner peripheral wall of the latter and projects out from the injection nozzle 712. On the other hand, a stopper 718 is formed substantially in the middle of the needle valve 714 so as to be opposite to the spacer 709. Further, a movable core 720 is provided at the top end of the needle valve 714 so as to be opposite to and connected with the iron core 706. The movable core 720 is biased downward by a coiled spring 722 disposed between the iron core 706 and the adjusting pipe 707. A split sleeve 724 is provided at the end portion of the body 710 in which the injection nozzle 712 is formed in such a manner that it covers the end portion of the body 710.
The sleeve 724 comprises an inner sleeve nozzle 730 and an outer cover nozzle 731 as shown in FIGS. 8 and 9. The sleeve nozzle 730 and the cover nozzle 731 constituting the sleeve 724 are made of 6--6 nylon (containing 30 wt % glass), polyacetals, PPS or the like.
The inner sleeve nozzle 730 has two fuel passages 732 and 733. The fuel passages 732 and 733 are each conical in shape so that the sectional area thereof is reduced as going toward the downstream of the spray of the fuel. The inner sleeve nozzle 730 is formed in the outer peripheral wall thereof with semicircular grooved portions 734, 735, 736, 737, 738 and 739 each of which serves to form an air passage. The grooved portion 734 serving to form the air passage can have the cross section of rectangular shape shown in FIG. 16, for example, in place of the cross section of circular arc shape shown in FIG. 15. The inner sleeve nozzle 730 has a tapered surface 730a and an annular stepped portion 730b.
The outer cover nozzle 731 has six holes 744, 745, 746, 747, 748 and 749, for example, these holes each penetrating from the inside wall to the outside wall and serving to form an air induction port. It is sufficient for each of the holes 746 to 749 to have a passage area which is not smaller than the passage area surrounded by the grooved portion 734, 735, 736, 737, 738 or 739 and the inside wall of the cover nozzle 731. Further, the cover nozzle 731 is formed at the tip end thereof with a diffuser portion 750 which serves to guide the spray of the fuel stirred and atomized by the assist air and regulate the same within the desired spray cone angle as well as a chamfered portion 751 which is to be used for positioning in the automatic assembling process. Gaps G1 and G2 shown in FIG. 10 are designed to have a clearance of about 0.1 to 0.3 mm. This makes it possible to prevent other parts than the stepped portion 730 from being melted and welded at the time of the ultrasonic welding which is to be described later, thereby preventing the assist air passage from being clogged due to generation of unnecessary fins.
FIGS. 8 to 11 are illustrations showing the structure of the sleeve nozzle 730 after the welding. Namely, FIG. 8 is a side view of the sleeve nozzle 730, FIG. 9 is a view as viewed from an arrow mark direction A of FIG. 8, FIG. 10 is a sectional view taken along the line I-O-I of FIG. 9, and FIG. 11 is a view as viewed from an arrow mark direction B of FIG. 10. Further, FIGS. 12 to 14 are illustrations showing the shape of the sleeve nozzle 730 before it is welded, in which FIG. 12 is a side view, FIG. 13 is a view as viewed from an arrow mark direction C of FIG. 12, and FIG. 14 is a sectional view taken along the line II-O-II of FIG. 13. Moreover, FIG. 15 is a sectional view taken along the line III--III of FIG. 14. In addition, FIGS. 17 to 19 are illustrations showing the shape of the cover nozzle 731 before it is welded, in which FIG. 17 is a side view, FIG. 18 is a view as viewed from an arrow mark direction D of FIG. 17, and FIG. 19 is a sectional view taken along the line IV-O-IV of FIG. 18.
It is noted here that FIGS. 12 to 14 illustrate the stepped portion 730b and the guide portion 752, the stepped portion 730b being shown for a longer distance in the axial direction as compared with FIGS. 8 to 11. This axial elongated portion of the stepped portion 730b is the portion which is to be melted at the time of the ultrasonic welding which is to be described later. On the other hand, the guide portion 752 is formed to have an outside diameter which is substantially equal to an inside diameter of the cylindrical surface 731a of the cover nozzle 731 shown in FIG. 19, which guide portion forms a guide surface by means of which the sleeve nozzle 730 is inserted into the cover nozzle 731 with the stepped portion 730b thereof being melted in the welding process, so that a fixed gap is maintained between the cover nozzle 731 and the sleeve nozzle 730.
Within the delivery pipe 702, the passage of the fuel taken from the fuel intake port is formed between a first O ring 758 and a second O ring 759. The air induced through an air passage 702a and a passage 702b formed in the delivery pipe 702 is radially sealed between the second O ring 759 and a third O ring 760.
Next, description will be given of the procedure for manufacturing the above-described embodiment.
The cover nozzle 731 and the sleeve nozzle 730 are formed by means of the injection molding. The both nozzles are unified by being welded to each other as the sleeve nozzle 730 is inserted into the cover nozzle 731. The sleeve nozzle 730 is inserted from an opening 731c of the cover nozzle 731.
On the occasion of the welding, as shown in FIG. 10, the sleeve nozzle 730 is inserted into the cover nozzle 731, the cover nozzle 731 and the sleeve nozzle 730 are pressed against each other so that the stepped portion 730b and the stepped portion 731b are subjected to the ultrasonic pressure, thereby melting the stepped portion 730b by ultrasonic vibrations. Fins produced by ultrasonic waves are received in a fin receiver 753 so as to avoid exerting bad influence on the O ring 760 shown in FIG. 7. In the course of press-fitting the sleeve nozzle 730 while melting the stepped portion 730b by the ultrasonic waves, when the tapered surface 730a is brought into contact with the cover nozzle 731, application of the ultrasonic vibrations is brought to an end.
In the welding process described above, in case of press-fitting the sleeve nozzle 730 while melting the stepped portion 730b, the gaps G1 and G2 are maintained due to the guide portion 752 as shown in FIG. 10, thereby preventing generation of fins caused due to unnecessary melting and welding.
In FIG. 7, the sleeve nozzle 730 is assembled to the fuel injection valve 701 in such a manner that the sleeve nozzle 730 is press-fitted on the outer periphery of the nozzle body 710 of the fuel injection valve 701 and, in order to prevent come-off, a grooved portion 710a and a projection 730c are fastened to each other by means of snap-fitting. In this case, the relative position of the nozzle body 710 and the sleeve nozzle 730 in the direction of rotation is decided as well.
According to the above-described embodiment, the fuel taken from the fuel intake port is passed through the regulating portion and then injected through the injection nozzle 712. The injected fuel is divided into two directions by the fuel passages 732, 733 of the sleeve nozzle 730 and, thereafter, atomized at once due to air jets issued from the grooves 734, 735, 736, 737, 738 and 739.
Further, according to the above-described embodiment, since the supply of the assist air is interrupted, it is possible to obtain two spraying patterns, that is, fuel injection with high directivity and spray of well atomized fuel. Particularly, by directing the two fuel passages 732, 733 formed in the sleeve nozzle 730 toward the intake valves of the internal combustion engine, respectively, when the assist air is out off, the fuel passing through the fuel passages 732, 733 can be supplied to the intake valves with high directivity. This makes it possible to reduce the amount of fuel adhered to the wall surface of the intake pipe and hence to supply the required amount of fuel to the combustion chamber of the internal combustion engine with accuracy. Further, in the above-described embodiment, the outlets of the assist air passages formed between the cover nozzle 731 and the sleeve nozzle 730 are so arranged as to cross the streams of fuel injected from the fuel passages 732, 733 at the outlets of the two fuel passages 732, 733 and, moreover, they are distributed substantially uniformly around the two fuel passages 732, 722, as shown in FIGS. 9 and 10 in detail. For this reason, it is possible to make the fuel injected from the two fuel passages 732, 733 collide against the assist air effectively when the assist air is supplied, thereby making it possible to obtain the spray of fuel in which the fuel is atomized satisfactorily and stirred as if it is a single stream of sprayed fuel. In consequence, mixing with the air taken into the internal combustion engine can be assured favorably and the fuel can be taken into the combustion chamber with reliability by being carried by the flow of intake air even when the amount of intake air is small, so that the required amount of fuel can be supplied to the combustion chamber of the internal combustion engine as being held in the state suitable to obtain a good combustion.
Further, in the foregoing description, the number of fuel passages has been described as being two since the number of intake valves is two, and however, it is possible to easily design the number of fuel passages to be even one or more than three as occasion demands. Incidentally, the supply of the assist air can be interrupted in accordance with the load of the internal combustion engine or the like. For example, it is possible to supply the assist air at the time of low load operation in which the amount of intake air is small while cut off at the time of high load operation in which the amount of intake air is large.
With the structure of the above-described embodiment, in forming the assist air passage in the resinous sleeve 724, the sleeve 724 is divided into two parts, that is, the inner cylindrical sleeve nozzle 730 and the outer cylindrical cover nozzle 731, and the assist air passage is formed between them, and therefore, it becomes possible to form a plurality of assist air passages each having a complicated shape without difficulty.
Moreover, the induction ports of the assist air are formed as penetrating through the cover nozzle 731 from the outside wall to the inside wall, and the cover nozzle 731 is overlapped by the sleeve nozzle 730 at the portion thereof nearer to the fuel injection valve than (or above) these induction ports, and the cover nozzle 731 and the sleeve nozzle 730 are welded to each other at this overlapped portion, and therefore, it is possible to prevent generation of fins and clogging of the assist air passages which are expected to take place when the cover nozzle 731 and the sleeve nozzle 730 are welded to each other around the assist air passages formed below the induction ports.
In addition, in order to form the gap between the cover nozzle 731 and the sleeve nozzle 730 except the above overlapped portion, when the cover nozzle 731 and the sleeve nozzle 730 are welded to each other at the above-described overlapped portion as the sleeve nozzle 730 is inserted into the cover nozzle 731, the guide portion 752 is formed. Therefore, it is possible to prevent the cover nozzle 731 and the sleeve nozzle 730 from being welded to each other around the assist air passages and hence to prevent the generation of fins and the clogging of the assist air passages.
FIG. 20 shows a fourth embodiment of the present invention.
In the fourth embodiment, the assist air passages are formed in the cover nozzle 731. Each assist air passage 772 is formed by slotting the inner wall of the cover nozzle 731.
FIG. 21 shows a fifth embodiment of the present invention.
In the fifth embodiment, the cover sleeve 731 is formed on the outer peripheral wall thereof with a projection 774 and the delivery pipe 702 is formed with a groove so that the sleeve 730 and the fuel injection valve 701 are positioned relative to the delivery pipe 702 due to this projection 774.
FIG. 22 shows a sixth embodiment of the present invention.
In the sixth embodiment, the fuel feed passage is of the top feed type.
In the sixth embodiment, the fuel is fed through a filter 776 and the inside of the adjusting pipe 707. To the fuel injection valve 701 of this top feed type is assembled the same sleeve 724 as that of the third embodiment described before.
In the embodiments described above, the assist air passage is wholly formed between the sleeve nozzle 730 and the cover nozzle 731 from the penetrating hole to the outlet thereof. However, part of the assist air passage may be formed as extending into the sleeve nozzle 730 and opened in the vicinity of the outlets of the fuel passages 732, 733 formed in the sleeve nozzle 730. In this case, the assist air passage extending into the sleeve nozzle 730 can be formed in such a manner that it is branched off from the assist air passage formed between the sleeve nozzle 730 and the cover nozzle 731 so as to extend toward the sleeve nozzle 730. This makes it possible to reduce the length of the assist air passage formed in the sleeve nozzle 730, thereby making it easy to form the assist air passage. Further, the position of the outlet of the assist air passage can be set freely relative to the positions of the outlet of the fuel passage, and therefore, it becomes possible to obtain the desired atomizing form.
As has been described above, according to the third to sixth embodiments of the fuel feed apparatus of the internal combustion engine, it goes without saying that the supply of the assist air makes it possible to obtain a favorable atomizing form and, in addition, it is possible to easily manufacture the split type sleeve that has a plurality of assist air passages of a complicated shape.
Since it is possible to easily form a plurality of complicated assist air passages by fitting and welding the inner member in and to the outer cylindrical member, high workability can be achieved in manufacturing and assembling the members, forming the assist air passages and the like operations.
Further, since the inner member is welded to the outer cylindrical member at the portion nearer to one of the openings of the outer member through which the inner member is inserted than the penetrating holes, clogging of the assist air passages, change of the passage area and the like problem can be prevented from taking place in the manufacturing process. | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to a keyboard electronic musical instrument, and in particular to a circuit for automatically generating a bass note corresponding to the lowest key depressed on one of the manuals other than the pedalboard. In a broader aspect, the invention also relates to a circuit for generating a single pulse in a serial data stream in response to the last-occurring pulse in the data stream produced by multiplexing a manual of the instrument.
Present-day electronic organs generally fall into three classes: smaller home organs which are voiced to simulate a wide range of modern instruments but are not designed to closely simulate a pipe organ, electronic theater organs which simulate the characteristic sound of a theater pipe organ, and institutional or classical organs which simulate pipe organs generally found in churches and concert halls. Although classical pipe organ literature is best played on a true pipe organ, such organs are very expensive and require frequent maintenance to maintain the pipes in tune. Furthermore, changes in humidity and temperature affect the operation and sound of the organ, and the number of technicians who can maintain and tune pipe organs is rapidly dwindling. Consequently, pipe organs have become so expensive that they are beyond the means of most musicians and many churches.
In order to permit classical literature to be played, electronic organs have been developed which simulate, to varying degrees of closeness, the sound of a pipe organ. One approach is to utilize a pure digital system wherein the sounds produced by the various instruments are digitally stored in memories which are then addressed at a variable rate depending on the keys depressed to produce the tones of the instruments at the frequencies desired. Systems of this type have unique problems which prevent them from being completely satisfactory, however. Firstly, the number of harmonics as a function of the frequency of the waveform varies somewhat because of the limited number of sample points at low frequencies, and, secondly, aliasing is a significant problem. Other organs of this type utilize pure analog techniques where individual tone generators produce the various voices and complex switching arrangements are utilized to key the various tones. The circuitry and switching arrangement for such an organ is extremely complex and unwieldy, however, and this greatly increases the physical size and cost of the organ as well as posing significant maintenance problems. The third approach, and that which is employed in the present system, is to combine digital and analog techniques to utilize the advantages inherent in each of them.
In a pipe organ or an electronic organ simulating a pipe organ, the upper manual is referred to as the Swell manual because the volume of those voices was traditionally controlled by a swell chamber having a series of shutters which opened and closed under the control of the organist. The lower manual is referred to as the Great manual, and it, like the Swell manual, comprises sixty-one keys. The pedal manual comprises thirty-two pedals arranged in a convex pattern. The voice controls are referred to as stops and take the form of rocker tabs, blade-type tabs or drawbars.
Such organs also include a particular type of special effect control known as couplers, both intermanual and intramanual. Intermanual couplers enable voices normally assigned to one manual, including the pedalboard, to be played on another manual. For example, the pedalboard can be caused to play voices assigned to certain ranks of the Great manual, or the Swell manual may be coupled to the Great manual and vice versa. Intramanual couplers, on the other hand, enable expansion of the basic rank of pipes. For example, if an eight foot flute voice is played on the Great manual, and the four foot Great to Great coupler is activated, the organ will produce both the eight foot flute and the four foot flute. Likewise, if the sixteen foot Great to Great coupler is actuated, a sixteen foot flute will also be played.
A technique which is often employed in pipe and electronic organs is referred to as unification, which permits more ranks of pipes or voices to be produced without duplicating each pipe or voice in the rank. For example, a rank of diapasons at the eight foot level requires sixty-one pipes, and in a non-unified system, to add a rank of four foot diapasons, an additional sixty-one pipes would be necessary, for a total of one hundred twenty-two pipes. However, of the five octaves of four foot diapasons, four of them are exactly at the same pitch as the original eight foot rank of diapasons, so that there are forty-eight redundant pipes. In a unified system, then, for each additional footage, only twelve pipes or keyers are added, so that for the combined two foot, four foot, eight foot and sixteen foot ranks, a total of only ninety-seven pipes or keyers are necessary. The disadvantage to this is that the chorus effect is not as pronounced, but this is offset by the very substantial cost savings.
Pipe organs are capable of producing voices known as mixtures, which comprise two to five or more pitches produced simultaneously by depressing a single key. The pitches are generally unison and mutation pitches, so that a 1 3/5 foot mixture comprises a 2 foot pitch, a 1 3/5 foot pitch, and a 1 foot pitch, for example. The rank of the mixture determines the pitches that are played, so depending where on the manual the key is depressed, the mixture will comprise either two unison and one mutation, as in the previous example, or two mutations and one unison. In this latter case, the mixture would comprise, for example, a 11/3 foot pitch, a 2 foot pitch, and a 22/3 foot pitch.
In an electronic organ of the type in question, there are, of necessity, a large number of interconnections between the manuals, keyswitches, couplers, stops, keyers and tone generators, which results in a very complex system. Such complexity greatly increases the cost of manufacturing and maintaining the organ and provides numerous opportunities for malfunctions to develop.
With organs of the classical variety having two or more manuals and a full pedalboard, they are extremely difficult instruments to play with any degree of proficiency. Not only must the organist play with both hands on one or more of the manuals, but must also coordinate his or her feet, which are used to play the pedals. In much classical literature, the staff of music which is written for the pedals is often of a high degree of difficulty, and therefore requires a proficient musician to play it properly.
A problem which is encountered in many churches in small communities, is that they are not able to attract an organist having sufficient skill to play the pedals with any degree of proficiency. Persons able to play the piano are usually quite readily available, however, and they generally are able to play the music written for the upper manuals of the organ because the keys are arranged similarly to those of a piano. This is not entirely satisfactory, however, because when the pedals of the organ are not played, the music lacks the characteristic fullness of a pipe organ.
Prior attempts to solve this problem have involved circuitry which plays one or more bass notes corresponding in note name to a key or group of keys played on the accompaniment manual but sounding one or more octaves lower. In many cases, this has been accomplished by rather complex switching arrangements, which have proven to be troublesome from the standpoint of manufacturing costs and difficulty of maintenance. To reduce the switching complexity, other solutions have entailed scanning of the accompaniment manual from the lower keys to the higher keys and producing a control pulse corresponding to the first depressed key of the accompaniment manual which is encountered. Since this is, of necessity, the lowest depressed key on the accompaniment manual, the system works reasonably well as long as the scanning is from low to high. Problems are encountered, however, where the manual is multiplexed from high to low, as it is in systems where the lower frequency footages are generated by delaying the keydown pulses in the data stream and then recombining them to form a composite data stream comprising the original keydown pulses as well as footage pulses in octavely related time slots.
It has been found that a reasonably full organ sound can be obtained by producing an additional tone corresponding in pitch to the lowest tone placed on the Great manual but voiced as if it were played by the pedalboard. Since this note on the accompaniment manual is not the first note in the data stream but the last note, problems arise because if the data stream is considered in real time during a scan of the manual, there is no information in the data stream which indicates whether the keydown pulse at any particular time is the last one in the data stream, or if a lower key has been depressed thereby producing yet another keydown pulse. Although long delay lines or utilization of dynamic registers or memories could be utilized to store the data stream for a preceding scan so that the proper keydown pulse during the next scan can be selected as that pertaining to the lowest depressed key on the accompaniment manual, such systems are quite complex and add significantly to the manufacturing cost of the organ.
The problem to be solved, then, is the provision of a circuit which will detect the last keydown pulse in the serial data stream and utilize this information to key a tone which is then voiced as if it were played by the pedals, and to accomplish this efficiently from the standpoint of circuit requirements.
SUMMARY OF THE INVENTION
The present invention overcomes the problems and disadvantages of prior art solutions by providing a relatively simple circuit which is responsive to keydown pulses in the lower two octaves of the Great manual and selects the last keydown pulse to initiate the generation of a further pulse, which is transmitted to the footage generator for the pedals. This pulse is then selectively delayed in time by increments of twelve time slots and the pulses are combined to form a data stream comprising keydown signals in time slots corresponding to the pedal footages which are selected. This data stream is then demultiplexed to key tones that are subsequently voiced as if they were played directly by the pedals.
A window circuit monitors the timing codes produced by the multiplexer, which correspond respectively to the keys of the Great manual, and opens the window concurrently with the time slot corresponding to the highest note in the lower two octaves, and closes the window after the time slot corresponding to the lowest key in the lower two octaves. During the time that the data window is open, keydown pulses from the data stream are gated to the preset inputs of a dual four bit counter, which has its outputs decoded to produce a pulse twenty-four counts after being preset. Thus, each keydown pulse in the lower two octaves will preset the counter, but since the window is only twenty-four bits wide, the decoded count will not be reached during the time that the window is open. This results in decoding of the count exactly twenty-four bits after the time the counter was preset by the last occurring pulse in the data stream for the lower two octaves. Since the time slot twenty-four bits later is octavely related to the time slot of the last keydown pulse, the note corresponding to this keydown pulse is of the same pitch and can be processed by standard shift register delay techniques to produce the desired footages.
The present invention is not limited to the production of a bass note, but the same circuit technique can be utilized for detecting the last keydown pulse in a data stream corresponding to a multiplex keyboard regardless of the direction multiplexing. For example, if the keyboard were scanned from low to high, and it were desired to insert only a single pulse in the serial data stream a given number of time slots after the time slot of the highest note, regardless of the number of keys depressed, then the same counter and gating arrangement could be utilized. In this case, the window would open with the scanning of the appropriate manual, and the counter would be continually reset until a predetermined number of time slots after the last setting of the counter by the last occurring pulse.
Specifically, the present invention contemplates an electronic organ including at least one keyboard having playing keys, a multiplexer for cyclically scanning the keys in succession from one end of the keyboard to the other and producing a time division multiplexed serial data stream comprising a plurality of time slots corresponding to the keys of the keyboard and keydown signals in time slots corresponding to actuated keys of the keyboard. A demultiplexer demultiplexes the serial data stream on its input and controls tone producing means to place tones on its output selected in accordance with the time slot positions of keydown signals in the serial data stream. The improvement is a pulse generating circuit interposed between the multiplexer and demultiplexer comprising an input to which the serial data stream is connected, a pulse output, means responsive to the keydown signals in the serial data stream on its input for generating on the pulse output a second serial data stream synchronized with the first mentioned data stream comprising a plurality of time slots in a single keydown pulse for each scan of the keyboard, wherein the single pulse is in a time slot of the second data stream which is separated in time from the time slot of the last keydown signal in the first mentioned data stream by a fixed number of time slots, and means for connecting the pulse output of the pulse generating circuit to the demultiplexer input.
It is an object of the present invention to provide a pulse generating circuit for an electronic organ which monitors a selected segment of the data stream and produces a keydown pulse in a time slot octavely related to the last-occurring keydown pulse in the data stream.
It is a further object of the present invention to provide an automatic bass generation system for use in a multiplexed organ wherein the last-occurring pulse in the serial data stream initiates a pulse which keys tones voiced as if they were produced directly by the pedals themselves.
A still further object of the present invention is to provide an automatic bass generation system of the type described above which is efficient from the standpoint of circuitry requirements and is capable of being easily integrated into existing electronic organ multiplexing technology.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a general block diagram for the digital front end of the multiplexed plural manual organ of the present invention;
FIG. 1A is a block diagram of the transpose and fold circuit;
FIG. 2 is a general block diagram of one of the keyers;
FIG. 3 is a more detailed block diagram of one of the keyer chips of FIG. 2;
FIG. 4 is a schematic of a tri-level encoder and decoder;
FIG. 5 is a block diagram of the variable counter system of one of the keyer chips;
FIG. 6 is a schematic of a plurality of the keyers identified as a block in FIG. 3;
FIG. 6A is a schematic of one of the discrete keyers shown as a block in FIG. 6;
FIG. 7 is a schematic of the inputs and outputs for the Great multiplexer and driver;
FIG. 8 is a schematic of the Great manual;
FIG. 9 is a schematic of the Great multiplexer and driver;
FIG. 10 is a schematic of the receiver shifter;
FIG. 11 is a schematic of the Swell or Pedal receiver;
FIG. 12 is a schematic of the multiplex control block;
FIG. 13 is a schematic of the couplers;
FIG. 14 is a schematic of the Great tab generator;
FIG. 15 is a schematic of the Principal tab collector;
FIG. 16 is a schematic of the multiplex percussion generator;
FIG. 17 is a schematic of the mixture gating and generation circuit;
FIG. 18 is a schematic of the mixture generator;
FIG. 19 is a schematic of the transposer;
FIG. 19A is a schematic of the transpose fold circuit; and
FIG. 20 is a schematic of the automatic bass circuit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to FIG. 1, the organ comprises a Swell manual 20, a Great manual 22, each of which comprises sixty-one keys, and a thirty-two note pedalboard 24. The Swell manual 20, Great manual 22 and pedalboard 24 are multiplexed in parallel by means of Great multiplexer and driver 26, which produces, on lines 28, a parallel, eight bit wide driver signal. The driver signals are connected to Swell manual 20, to pedalboard 24, and to Great manual 22 over lines 28.
For ease in referencing, the driver signals, which are actually a series of eight bit binary words wherein only one bit location is high at any one time, are referred to as "K" numbers or "K" drivers.
Swell manual 20 is connected to swell multiplex receiver 36 over eight lines 38, and pedalboard 24 is connected to Pedal multiplex receiver 40 over lines 42. The Great multiplexer and driver 26 also includes the receivers for Great manual 22, which are connected to it over eight lines 44. The reason for selecting the Great multiplexer 26 as the receiver, is that it must produce the delta data pulse, which is generated each time there is a new depressed key on great manual 22, and is connected to the multiplex percussion block 46 over line 48.
Although the same "K" drivers are used for all three manuals, the receivers are separate, and the outputs of receivers 36, 40 and 26 are the actual data streams, with a separate data stream for the Swell manual 20, the Great manual 22 and the pedalboard 24. The data streams from Swell multiplex receiver 36, pedal multiplexer receiver 40 and Great multiplex receiver 26 are connected to multiplex control block 50 over lines 52, 54 and 56, respectively. Multiplex control block 50 causes data to be output on alternate scans of the manuals, even though data is being inputted to it on each scan. As discussed earlier, the use of a double scan wherein data is outputted on every other scan enables the lower frequency footages to be generated by means of serial data stream delay techniques.
The Swell data stream from multiplex control 50 is connected to the coupler block 58 over line 60, the Pedal serial data stream is connected thereto over line 62 and the Great serial data stream over line 64. The couplers 58, which are controlled by tabs 66, enable the Great data on line 60 to sound as though it were played on the Swell manual, or enables data generated by the pedalboard, which data is connected to couplers 58 on line 62, to sound as though it were played on the Swell or Great manuals. This type of coupling is known as Intermanual coupling wherein the notes played on one manual are voiced in accordance with the voicing selected for another manual.
The other type of coupling utilized in large organs is known as intramanual coupling wherein notes played in one frequency range of a manual sound in either a higher or lower frequency range. For example, by delaying data which would normally sound in the eight foot range by twelve time frames, it will sound one octave lower in the sixteen foot range, because the manuals are scanned downwardly from the high end. If the data were advanced twleve time frames, then it would sound in the four foot range.
Returning now to the multiplexing circuitry, eight bit receiver shifter 70, which is an eight bit shift register, is synchronized by a pulse from great multiplexer and driver 26 on line 72, and produces on eight output lines 74 a series of eight bit binary numbers when the eight bit locations individually go high in succession. The eight bit locations of the receiver shifter outputs go high in succession for each change of state in the "K" numbers at the output of Great multiplexer and driver 26. The eight bit locations of receiver shifter 70 outputs 74 are referred to as "T" numbers. Thus, the various combinations of the "K" numbers and "T" numbers produce sixty-four separate states, which is more than adequate for the sixty-one notes of the Swell manual 20 and Great manual 22.
Swell tab generator 76, which is controlled by tabs 78, generates the various footages by delaying the serial data stream on input line 80 similar to the data shifting principle disclosed in U.S. Pat. No. 3,951,028, which is owned by the assignee of the present application. Swell tab generator 76 has four outputs, the first output 82 being connected through delay 84 to two celeste keyer blocks 86. Tone generator 88 is connected to keyers 86. The second output 90 from Swell tab generator 76 is connected to three complex keyer blocks 92, which are fed with tones from tone generator 94. Complex keyers 92 typically generate reeds and trombones, and utilize square wave voicing. Output 96 from tab generator 76 is connected to a bank of four flute keyers 98 supplied with tones from tone generator 100, and output 102 is connected to a bank of four principal keyers 104, which are supplied with tones from tone generator 106.
Keyers 86, 98, 104 and 92 basically demultiplex the multiplex serial data streams at their respective inputs and produce the appropriate tones on their outputs. For example, if the sixteen, eight, four, two and one foot tabs 78 Swell tab generator 76 are actuated, five pulses will appear in the data streams on outputs 82, 90, 96 and 102 for the depressed key, and these will be demultiplexed by the keyer banks 86, 98, 104 and 92 to produce sixteen foot, eight foot, four foot, two foot and one foot tones. The outputs 108 and 110 of keyer banks 98 and 104 are connected directly to the voicing circuitry (not shown), but the outputs 112 and 114 of celeste keyers 86 and complex keyers 92 are connected through FET tabs 116 and 118. Normally, the outputs of the keyers 86, 98, 104 and 92 have footages at sixteen foot, eight foot, four foot and two foot from each octave available, and FET tabs 116 and 118 enable a particular footage to be selected. In the flute keyer bank 98 and principal keyer bank 104, however, the footage generation is accomplished by tabs 78 in conjunction with swell tab generator 76 and the other tab generators to be described below.
The delay 84 for celeste keyer 86 is because the two celeste keyers 86 each only have a capacity of twenty-four bits of serial data, whereas the swell manual 20 and great manual 22 each have sixty-one keys. The delay provides a delay of thirteen bits so that the data does not shift through the celeste keyers 86 before latch command. If it would be desired to play the lowest thirteen notes of the swell and great manuals, which notes are effectively eliminated by delay 84, it would be necessary to add a third celeste keyer and eliminate delay 84. It will be noted that the flute keyer bank is provided with four keyers each having a twenty-four bit capacity, the principal keyer bank 104 is provided with four keyers each having a twenty-four bit capacity, and the complex keyer bank 92 is provided with three keyers each having a twenty-four bit capacity.
The pedal tab generator 120, which is also controlled by tabs 78 over lines 122, has a first output 124 connected to the flute keyer bank 98 and a second output 126 connected to the principal keyer bank 104. Great tab generator 128, which is controlled by tabs 78 over lines 130, has a first output 132 connected to the flute keyer bank 98 and a second output 134 connected to the principal keyer bank 104. Great tab generator 128 also has an output 136 comprising three lines havng pulses at the two foot, four foot and eight foot time slots, which are connected to a collector in the Pedal tab generator 120.
Chiff-harp-chime tab generator 138, which is controlled by tabs 78 over lines 140, is provided with eight foot serial data from the Great tab generator 128 over line 142. Its output 144 is connected to multiplex percussion block 46, which has a serial data output 146 connected to a bank of two percussion keyers 148, supplied by tone generators 150. The output 152 of percussion keyer bank 148 is connected through FET tabs 154 to the output line 156. Multiplex percussion block 46 produces a burst of serial data under the control of a delta data pulse on line 48, which is substantially longer in time than a scan of the keyboard, and produces a transient envelope characteristic of percussive sounds, such as those produced by a harp or chimes or the chiff characteristic of the pipe organ sound.
The auto bass generator 160 is controlled by tabs 78 over lines 162 and receives its input data from the Great serial data line 64 over line 164. This block is intended for persons not sufficiently skilled to play the pedals 24, and it monitors the lowest two octaves of the Great serial data on line 64 and inserts a pulse into the Great tab generator 128 over line 166 corresponding to the lowest key played on the great manual 22. It has been found that this technique produces a very pleasing pedal sound, although the versatility of selective playing of the pedals 24 is lacking.
The mixture generator 168 is controlled by tabs 78 over lines 170 and receives data from couplers 58 over lines 172. As discussed earlier, the mixture generator plays three footages by selecting only a single tab. For example, if a C key is pressed, the organ will play the C as well as the G above and below it, or the G note with the C notes on either side of it, depending on the octave in which the key is depressed. In the top two octaves, for example, the unison will sound as well as the 1 1/3 and 2/3 mutations, which corresponds to the notes G, C, G with a C key depressed. In the next octave, the unison as well as its first harmonic will sound together with the 1 1/3 mutation, which corresponds to the C, G, C keys with a C key depressed. In the next higher octave, the unison sounds together with the 1 1/3 mutation and 2 2/3 mutation (keys G, C, G) and in the highest octave, the unison, its first harmonic and the 2 2/3 mutation (C, G, C) will sound. The output from the mixture generator 168 is connected over line 174 to the principal keyer bank 104.
To summarize the block diagram illustrated in FIG. 1, the Swell manual 20, Great manual 22 and Pedal manual 24 are multiplexed in parallel fashion and connected to the respective inputs of multiplex control block 50. This passes the multiplexed data on alternate scans of the manuals and connects the serial data streams to the inputs of couplers 58. Couplers 58 route the serial data selected by the three manuals to the Swell tab generator 76, Pedal tab generator 120, Great tab generator 128 and mixture generator 168. The tab generators comprise a plurality of shift registers which delay the incoming data to produce the various footages, which are selected by tabs 78. The chiff-harp-chime generator receives data of the appropriate footage from the great tab generator 128 and transmits it to multiplex percussion block 46, which provides a data burst on line 146 to simulate a percussive envelope. The time of the data burst is controlled by the data delta pulse on line 43, which is generated by great multiplexer and driver 26 each time a new key is depressed. The auto bass block 160 receives its data directly from the great data stream on line 164, and transmits a single pulse of data to Great tab generator 128 which corresponds to the lowest note played on the Great manual. Great tab generator 128 routes this data to the appropriate keyer bank. The outputs of the tab generators are connected to the appropriate keyer banks 86, 98, 104, 92 and 148 wherein the serial data streams are demultiplexed and the corresponding tones appear on their respective outputs. Celeste keyers 86 and complex keyers 92 are provided with tab switching 116 and 118 on their outputs to select the desired footages.
Keyer banks 86, 98, 104, 92 and 148 will now be described. Each of the keyer banks comprises two, three or four individual keyer blocks as indicated in FIG. 1, and the keyer banks are the subject of Pat. 4,217,801. Basically, the keyer banks are comprised of individual keyer chips which may be interconnected in building block fashion to accommodate manuals of any length, and may be expanded as desired to accommodate the higher frequency footages, which are generated by a data delay technique described in the aforementioned U.S. Pat. No. 3,951,028.
Referring now to FIG. 2, the complex keyer bank 92 will be described, although each of the other keyer banks are similar except that they may comprise more or less individual keyer chips in the bank, as indicated in FIG. 1. Keyer bank 92 comprises three keyer chips 180, 182 and 184, which are connected in series. The high frequency multiplex clock signal and reset signal are combined on line 186 and connected to a tri-level input on each of chips 180, 182 and 184 so that the clocking and reset functions can be combined on a single line.
The serial data stream on line 188 comprises time slots corresponding on a one-to-one basis with the depressed keys of the manuals and contains keydown signals, customarily in the form of pulses, in time slots corresponding to depressed ones of the keys. This time division multiplexed data stream is fed to the serial data input 190 of keyer chip 180 in which it is delayed two octaves and then fed out on serial data output line 192. Each of keyer chips 180, 182 and 184 corresponds to two adjacent octaves, and it is for this reason that the serial data stream is delayed by time slots equaling two octaves. It will be recalled that the manuals are scanned in a downward direction beginning with the highest key and ending with the lowest key thereof, and it is for this reason that the serial data stream is first fed to keyer chip 180.
The delayed serial data stream on output 192 is connected to the serial data input 194 of chip 182, delayed by a period of two octaves, and fed out on output 196 to the serial data input 198 of keyer chip 184. In each of the keyer chips 180, 182 and 184, the serial data stream flows through a twenty-four bit shift register for demultiplexing and delay purposes. At the appropriate time in the scans of the manuals, a latch pulse appears on line 200, which is connected to the latch inputs 202, 204 and 206 of the keyer chips. At this time, chip 184 contains the top two octaves of the data, chip 182 the next two octaves, and chip 180 the last two octaves, wherein the data corresponds to the keys depressed. It will be recalled that the footages for complex keyer bank 92 are not selected by the swell tab generator 76, but are selected by FET tabs 118 on its output, The latch signals on inputs 202, 204 and 206 cause the internal latches within the chips to be clocked thereby transferring the keydown data to the individual keyers.
The tones are generated by a master tone generator 94 and supplied to keyer chip 184 over twelve input lines 212. Two of these lines include tri-level encoders 214 and 216 connected thereto which encode the tone signals with the binary encoded sustain switch data from switches 218, thereby avoiding the necessity for utilizing a second pair of pins for switches 218. In a similar fashion, attack switches 220, which are also binary encoded, are connected to chip 184 on the same line with one of the tones by means of tri-level encoder 222.
The twelve tones, which may be produced by a top octave synthesizing technique or by individual oscillators, are generally ibn the 8,000 Hz. to 4,000 Hz. range. The tones on lines 212 are divided by a factor of four in chip 184 so as to lower them by two octaves and then fed out on lines 224 to the tone input pins 226 of keyer chip 182 with the tri-level inputs. These tones are further divided in frequency by a factor of four to lower them an additional two octaves and fed out over lines 228 to the tone input pins 230 of keyer chip 180. By this successive frequency division of the tones, they are at the proper frequencies for the octaves related to the respective chips 180, 182 and 184.
Each of the chips includes sustain-type keyers wherein the keying envelope is selected by switches 218 and 220. The keyed tones at a footage for each of the pitches of the respective octaves are bussed together and fed to bus amplifiers 234 over lines 236, 238 and 240, respectively. The outputs from the bus amplifiers 234 are connected to voicing circuits 242 which are selected by tab FETs 118 and then through amplifier 244 to speaker 246.
Referring now to FIG. 3, one of the chips 180, 182 and 184 is shown in greater detail. The serial data stream on pin P14, which may be received either directly or from the serial data output pins of one of the other keyer chips, is fed into twenty-four bit shift register 250, which in turn feeds a twenty-four bit latch 252. Latch 252 receives the latch command from four bit latch delay 254, which in turn is fed by the latch signal on pin P15, and is clocked by the high frequency multiplex clock train brought in on pin P16 and decoded by tri-level gate 256. The four bit delay for the latch signal caused by delay 252 is necessary to enable the data to completely fill the highest frequency keyer chip 184. Although the latch command is generated by the "K" and "T" numbers, and could presumably be chosen such that data would completely fill the highest frequency keyer chip 184, the particular chips utilized are adapted for use also with conventional latch command which occurs at the end of a scan, and for this reason, the four bit delay is present and must be compensated for in generating the latch command.
The master reset on line 258 is separated out by tri-level gain 256. Latch 252 feeds a twenty-four section sustain envelope generator block 260 generally of the type disclosed in Patent 4,217,801. Envelope generators/keyers 260 are fed with sixty tones over lines 262 from forty-eight dividers 264, which produce the five octaves of tones necessary for the 16', 8', 4' and 2' footages for the two adjacent octaves keyed by the particular keyer chip 180, 182 or 184. Dividers 264 receive the twelve tones for a single octave over pins P29-P40 and, in addition to performing the above-discussed frequency division, pass these tones to keyers 260 and to tone output pins P17-P28. Tri-level gates 266, 268 and 270 separate out the attack and sustain commands for attack and decay counters 272 and 274, and tri-level encoders 276, 278 and 280 re-encode this data on tone output pins P17, P18 and P19. Tri-level gate 282 separates a test signal from the A tone.
FIG. 4 illustrates a typical tri-level gate wherein the tri-level signal 288 is produced by combining a high frequency signal, such as tone signal 290, with a static signal such as that produced by switch 292 as it switches between states one and two. In state two, diode 294 clamps the tone swing between +5 v. and 0 v., whereas in state one, tone signal 290 is permitted its full swing between +5 v. and -9 v. Decoding of the static signal may be accomplished by means of D-type flip-flop 296, which is clocked by the signal on line 298 and transfers the -9 v. signal on the D terminal 300 to the Q output 302 when the tri-level input on line 304 swings to -9 v.
With reference to FIG. 5, the circuitry for selecting the effective count lengths of counters 272 and 274 is shown. Counters 272 and 274, which may be of the polynomial counting type, shift register type, binary type or decimal type, are clocked by the high frequency clock pulse trains on lines 306 and 308 from tri-level decoder 256. Attack counter/decoder 272 has two outputs 310 and 312, which are connected respectively to one of the inputs of AND gates 314 and 316, the other inputs of which are fed by the inverted and non-inverted logic levels on line 318 leading from tri-level gate 266. With output 310 being the shortest count, when a logic level on line 318 is logic 1, AND gate 314 will be enabled and the pulse train on line 320 will be at the higher frequency. Conversely, when a logic level on line 318 is logic 0, AND gate 316 will be enabled and the pulse train on line 320 will be at the lower frequency. It should be noted that counter/decoder 272 may have more than two outputs so that the relative frequencies may have a ratio other than 2:1. The pulse train on line 320 is fed to inputs 389 and 392 of the circuit shown in FIG. 6 in both its inverted and non-inverted form.
Sustain counter/decoder 274 has four outputs which are fed respectively to one of the inputs of AND gates 322, 324, 326 and 328. As was the case with counter 272, the output connected to AND gate 322 is the least significant bit and represents the shortest count length, and the output connected to AND gate 328 is the most significant bit with the longest count length. The four outputs of counter 274 need not be four consecutive counts of the counter, but may be spaced as required by the particular sustain characteristics which are to be achieved. The other inputs of AND gates 322, 324, 326 and 328 are fed by outputs 330 from binary to decimal decoder 332. Decoder 332 is fed by a two bit binary word on lines 334 and 336 produced by tri-level gates 268 and 270. Depending on which of AND gates 322-328 is enabled, the pulse train on line 338 will have a correspondingly higher or lower frequency and, thus, four different sustains can be selected depending on the logic levels on pins P29 and P30. The pulse train on line 338 is connected to the inputs 391 and 393 of the circuit shown in FIG. 6 in its inverted and non-inverted forms, respectively.
Counter/decoders 272 and 274 feed twenty-four banks of four keyers each, wherein each of the four keyers produces one of the footages required by that particular note, for example, the 16', 8', 4' and 2' footages.
Referring now to FIG. 6 a portion of the keyer/divider combination 260, 264 shown generally in FIG. 3 will be described in detail. The tone, for example, the C♯ tone in the highest octave, is fed in from pin P35 on line 340 into R/S driver 342, which connects the tone to one of the inputs 344 of individual keyer 346. The tone is also fed through a series of divide-by-two dividers 348, 350, 352 and 254, which present tones at one of the inputs to keyers 356, 358 and 360 at the 4', 8' and 16' pitches. The 2', 4', 8' and 16' pitches for the C♯ tone in the next octave lower are accomplished by tying together the tone inputs of the 2' lower octave keyer 362 and the 4' higher octave keyer 356, by tying together the tone inputs of the 4' lower octave keyer 366 and the 8' higher octave keyer 358, and by tying together the tone inputs of the lower octave 8' keyer 368 and the 16' higher octave keyer 360. The 16' lower octave keyer 370 is fed directly by divider 354, and the master reset is brought in on line 372.
Envelope generator 374 for the higher octave C♯ tone comprises field effect transistors (FET) 376, 378, 380, 382, 384 and 386 having their sources and drains connected in series. The gate terminal 388 for FET 376 is fed by the non-inverted A output from attack counter 272 on line 389, whereas the gate 390 for FET 378 is fed by the inverted output A from attack counter 272 on line 392. The gates 396 and 398 of FET's 384 and 386 are controlled by the inverted and non-inverted pulse trains on lines 400 and 402, respectively, from decay counter 274.
The gates 406 and 408 of FET's 380 and 382 are controlled by the non-inverted and inverted outputs, respectively, from NAND gate 410, and when a keydown signal on line 412 is received from one of the latches 252 designating a particular depressed key, FET 380 will be enabled. Similarly, when the key is released and the opposite logic level is present on line 412, FET 380 will be disabled and FET 382 will be enabled. Thus, the attack characteristics are controlled by the frequency of the signals on lines 389 and 392, and the relative capacitances of capacitors 401 and 403. Capacitor 401 may have a capacitance of 0.001 microfarad, and capacitor 403 may have a value of 0.47 microfarads, for example.
The keying envelope is connected to the control inputs of keyers 346, 356, 358 and 360 over line 418. The envelope adjust voltage on lines 420 and 422 is controlled by a potentiometer (not shown) external to chips 180, 182 and 184, and serves to set the keyer current.
When a keydown signal is received on line 412, FET 380 will be turned on thereby providing a high conductivity path between FET 378 and capacitor 403. As FET 376 opens and closes, the voltage on line 420 will incrementally charge capacitor 401. Similarly, as FET 378 switches on and off, the voltage on capacitor 401 will discharge into capacitor 403 thereby raising the voltage level on line 418 incrementally and gradually over a period of time. As the transistors continue to oscillate between their on and off states, the voltage on capacitor 403 will gradually charge towards the voltage level on line 420. The time interval required for the voltage on capacitor 403 to charge fully is determined by the frequency of the signal on lines 389 and 392, as developed by variable count length attack counter 272, and by the ratio values, rather than the particular sizes, of capacitors 401 and 403.
When the key is released and the logic level on line 412 returns to the opposite level, FET 380 will be disabled and FET 382 will be enabled, due to the inverting function of NAND gate 424, so that there is a path of high conductivity between FET 384 and capacitor 403. As FET's 384 and 386 are alternately enabled by the out-of-phase pulse trains on lines 400 and 402, capacitor 403 will incrementally discharge into capacitor 404, and capacitor 404 will discharge through FET 386 to ground on line 426. Thus, the voltage level on line 418 will gradually return to the lower voltage level so as to disable keyers 346, 356, 358 and 360.
FIG. 6A shows one possible configuration for keyers 346-370. It comprises a pair of field effect transistors 428 and 430 connected in series wherein the gate 432 of FET 428 is connected to line 434, which in turn is connected to control line 418 from envelope generator 374. The gate 436 of FET 430 is connected to line 344, which carries the highest frequency footage tone from line 340, in the case of keyer 346. Thus, when a tone is present and there exists a keying voltage, the keyed tone will appear on line 438, which is connected to bus amplifiers 234 (FIG. 2). When the key is released, the voltage decays out and the keyer will be turned on.
The lower octave envelope generator 440 functions identically to generator 374 and is controlled by the keying signal on line 442. Again, the attack characteristics are controlled by the frequency of the pulse trains on lines 389 and 392 and by the ratio of capacitors 444 and 446. The decay characteristics are controlled by the frequency of the pulse trains on lines 400 and 402 and by the ratio of capacitors 448 and 446. In this case, however, line 450 carries the keying signal and actuates the keyers 362, 366, 368 and 370, which pertain to the next lower octave.
The multiplexing system for the Great manual 22, Swell manual 20 and pedalboard 24 will now be described in detail. FIG. 7 illustrates the various inputs and outputs for great multiplexer and driver 26, wherein lines 28a carry the inversions of the K numbers referred to earlier. The circuitry in this and the subsequent figures is drawn in negative logic. Lines 456 are connected to lines 28a and two inverters 458 such that the signals on lines 28 are the noninverted K numbers. Multiplexer and driver 26 causes lines 28a to carry a logic 1 (negative voltage) in succession for a period of eight time frames each as the manuals 20, 22 and 24 are scanned.
A portion of Great manual 22 is illustrated in FIG. 8 and it will be seen at the inverted K lines 28a are connected, respectively, to the buses or switch rails 462 associated with the eight groups of keyswitches 460. Thus, as lines 28a are sequentially activated, the associated bus 462 is also actuated thereby enabling the keyswitches 460 which come into contact with it depending on which keys of the manual 22 are depressed.
Lines 44, which carry the I numbers, are connected respectively to the line 464 connected to the respective keyswitch 460 in each of the eight groups. Multiplexer 26 (FIG. 7) enables lines 44 in sequence and repetitively in synchronism with the mutliplex clock pulses on line 466 from multiplex clock 468. On each scan of manual 22, lines 44 are enabled in sequence eight times, but because buses 462 are enabled in sequence only once per scan of the manual 22, a particular keyswitch 460 is scanned only once per scan of the manual. Although only forty-four keyswitches 460 have been illustrated, an institutional organ will typically comprise manuals of sixty-one keys each so that the I6 and I7 lines will also be connected to their respective buses (not shown).
Since each of the keyswitches 460 on Great manual 22 is scanned individually, a time division multiplexed data stream will be produced by multiplexer 26 on line 470 (FIG. 7). This data stream comprises a time slot for each of the keyswitches 460 wherein pulses appear in those time slots corresponding to depressed keys of the Great manual 22. At the end of each scan of manual 22, the K and I numbers are decoded internally in multiplexer 26 and a single pulse is produced on line 472. This pulse is known as the demultiplex latch pulse, the causes the serial data to be demultiplexed by the appropriate keyers 86, 98, 104, 92 and 148 (FIG. 1). The manner of decoding the multiplex drivers to generate a pulse of a particular time in the scan of the keyboard is well known in the art. Multiplexer 26 also generates a delta data pulse on line 48 each time there is a new key depressed on Great manual 22. Line 474 carries a reset pulse for purposes of system reset.
An exemplary circuit for generating the aforementioned K pulses and activating the I lines 44 is illustrated in FIG. 9. An eight bit shift register 476 is clocked by the multiplex clock train on line 466 and causes lines 478 to be activated in sequence from left to right as viewed in FIG. 9. Since lines 478 are connected to the gates of FET's 480, FET's 480 will be turned on in sequence thereby permitting lines 44 to be connected to data line 482 in sequence. Shift register 476 is connected as a recirculating shift register by virtue of lines 478 being connected to NOR gate 486.
On the eighth time frame of each cycle of shift register 476, a pulse will be generated on clock input line 490. The trailing edge of this pulse clocks eight bit shift register 492 thereby activating output lines 494 connected to the respective stages of shift register 492 in sequence. Lines 494 are held activated for eight clock pulses until the line 478 is deactivated. Output lines 494 are connected through inverters 496 to produce inverted K pulses on lines 28a.
Lines 28a are not only connected to Great manual 22, but are also connected to the buses (not shown) of pedalboard 24 and Swell manual 20. It should be noted, however, that pedalboard 24 generally comprises thirty-two pedals rather than sixty-one keys as in the case of Great manual 22 and Swell manual 20. Lines 28a are connected to Swell manual 20 and pedalboard 24 in the same manner as they are connected to Great manual 22, which is illustrated in FIG. 8.
FIG. 10 shows receiver shifter 70, which produces the T numbers on lines 74 for multiplexing the Swell manual 20 and pedalboard 24 as well as provide timing for the remainder of the system in conjunction with the K pulses produced by multiplexer 26 (FIG. 7). The T0-T7 pulses produced on lines 74 are in synchronism with the I0-I7 activating pulses produced on the outputs 478 of the respective stages of shift register 476 (FIG. 9). They are produced by shift registers 498 and 500, which are clocked by the train of clock pulses on lines 501 and 502 from inverter 503. Inverter 503 is connected to multiplex clock line 72 (FIG. 7). Data is loaded into shift register 498 on line 504 as a direct result of the multiplex latch pulse on line 506, which is connected to line 472 from multiplexer 26 (FIG. 7). Line 506 is connected to one of the inputs of NOR gate 508, the output of which is inverted by inverter 510. As the pulse on the data input 504 of shift register 498 is shifted through it in synchronism with the multiplex clock pulses on line 501, the Q1, Q2, Q3 and Q4 outputs are sequentially activated. The Q4 output is connected to the data input of shift register 500 over line 512 so that the Q4 output pulse is then shifted through shift register 500 and sequentially activates the Q1-Q4 output lines thereof. The Q1-Q4 outputs of shift register 498 and the Q1-Q3 outputs of shift register 500 are connected to the inputs of NOR gate 514, the output 516 of which is connected to the other input of NOR gate 508. This arrangement causes shift registers 498 and 500 to function as a recirculating eight bit shift register. This activates the T0-T7 lines 74 in sequence encyclically each scan of manuals 20 and 24. As indicated earlier, the T pulses are in synchronism with the I pulses produced by multiplexer 26. The multiplex latch pulse on line 506 serves to keep shift registers 498 and 500 in synchronism with multiplexer 26.
FIG. 11 illustrates either swell receiver 36 or pedal receiver 40. Lines 74 to receiver shifter 70 shown in FIG. 10 are connected to one of the inputs 517 of the respective AND gates 518, and the other inputs 519 are connected to the outputs of inverters 520. Inverters 520 are connected to the I0-I7 lines 38 and 42 connected to the ganged keyswitches of either the Swell manual 20 or pedalboard 24. The receiver illustrated in FIG. 11 is identical for Swell manual 20 and pedalboard 24, and the manner in which lines 38 and 42 are connected to the keyswitches is similar to that illustrated in FIG. 8 in connection with Great manual 22.
The T pulses on lines 74 enable AND gates 518 in sequence so that one group of ganged keyswitches at a time is connected to the outputs 524 of AND gates 518. Since the K drive pulses from multiplexer 26, which appear on lines 28a (FIG. 7), activate the buses for the Swell manual 20 and pedalboard 24 in sequence and for eight time slots each, a time division multiplexed data stream appears on the output 526 of NOR gate 528. This output is inverted by inverter 530, and the serial data stream appears on lines 52 and 54 for the swell receiver 36 and pedal receiver 40, respectively. It should be noted that, because the T pulses from receiver shifter 70 (FIG. 10) are generated in synchronism with the I0-I7 enabling pulses of multiplexer 26 (FIG. 7), and because the K pulses generated by multiplexer 26 are common to manuals 20, 22 and 24, the serial data streams generated in parallel on lines 52, 54 and 56 (FIG. 1) are synchronized with each other.
The serial data streams on lines 52, 54 and 56 are fed into multiplex control block 50, which is illustrated in detail in FIG. 12. As mentioned earlier, the various footages selected by tabs 78 are achieved by delaying the pulses corresponding to depressed keys of the various keyboards by one or more octaves or by a portion of an octave. Accordingly, the actual data stream by the time it reaches keyers 86, 98, 104, 92 and 148, is considerably longer than the sixty-one time frames associated with manuals 20 and 22 and the thirty-two time frames associated with pedalboard 24. This means that the keyboards cannot be again scanned immediately and produce serial data because this data would overlap with the delayed pulses associated with the lower frequency footages.
The function of multiplex control block 50 is to provide data to couplers 58 and to the automatic bass circuit 160 (FIG. 1) on alternate scans of manuals 20, 22 and 24. This alternate scan technique greatly simplifies the timing and control of the multiplexing of the manuals and synchronization of the demultiplexing keyers 86, 98, 104, 92 and 148 with multiplexing of the manuals. Serial data from the Great manual multiplexer 26 on line 470 is connected to line 56 in FIG. 12, and this is connected to one of the inputs of AND gate 526. The other input of AND gate 526 is connected over line 528 to the Q output of D-type 4013 flip-flop 530. The clock input 532 of flip-flop 530 is connected to the demultiplex latch line 472 of multiplexer 26 so that flip-flop 530 is clocked once each scan of the Great manual. The Q output of flip-flop 530 is connected over line 534 to the D input thereof. Flip-flop 530 functions as a divide-by-two and enables AND gate 526 on alternate scans of Great manual 22. Thus, on the first scan thereof, the Q output of flip-flop 530 will enable AND gate 526, but when the demultiplex latch pulse is received on line 532 at the end of that scan, the Q output will change states thereby disabling AND gate 526. This has the effect of permitting Great multiplex data on line 56, although it is generated on each scan of Great manual 22, to be passed by AND gate 526 to output line 536 only on alternate scans. Line 528 is connected over line 538 to one input of each of AND gates 540 and 542 so that these AND gates are also enabled on the same alternate scans of the Swell manual 20 and the pedalboard 24, respectively.
The pedal serial data on line 62 is delayed two time slots by flip-flops 544 and 545, and the swell serial data on line 60 is delayed two time slots by flip-flops 546 and 547. Flip-flops 544-547 are clocked by the inverted multiplex clock train on line 548. The pedal data and Swell data is delayed simply for the purpose of causing it to be in synchronism with the Great data on line 56, which is delayed by two time slots due to the internal configuration of multiplexer 26. On output lines 536, 60 and 552, then, the serial data from all three manuals is in perfect synchronism. Due to the action of AND gates 526, 540 and 542, data is present only on alternate scans of manuals 20, 22 and 24, although they are actually being scanned continuously, and serial data is being generated on every scan thereof. Data on line 164 from Great manual 22 is connected to the automatic bass circuit 160 over line 164, and to couplers 58 over line 64. Swell data is connected to couplers 58 over line 60, and the pedal data on line 552 is gated by AND gate 556 to line 62, which is connected to couplers 58. When the automatic bass tab is switched on, a control signal on line 558 from inverter 560 will disable AND gate 556 so that normal pedal data will be blocked. As will be described below, the pedal data is then produced by the lowest depressed key on the Great manual 22.
With reference now to FIG. 13, the couplers 58 will be described. Basically, the function of an intermanual coupler is to route the data generated by one manual into the data stream corresponding to another manual. For example, if the Swell to Great tab is actuated, a depressed key on the Great manual will cause a tone corresponding to the depressed key of the Great manual and also a tone corresponding to the same key on the Swell manual, even though the latter key is not depressed. Similarly, the pedalboard can be coupled to the Great manual and to the Swell manual so that actuation of a pedal has the capability of producing tones corresponding to keys on the Great and Swell manual.
Another type of coupling is intramanual coupling wherein the actuation of a key in the eight foot range, for example, will also produce tones in the four foot range and/or sixteen foot range, and, in some organs, may even be coupled into the one foot or two foot range or down in frequency to the thirty-two foot range. In intramanual coupling, however, the coupling is confined to the manual itself, as opposed to intermanual coupling wherein one manual is coupled to the other.
As shown in FIG. 13, the Swell manual data is brought into couplers 58 over line 60 and the data corresponds to the four foot range of the Swell manual. If switch 560 is closed, AND gate 562 will be enabled and the swell data from line 60 will be passed by AND gate 562 onto the four foot output line 564. The serial data stream on line 60 is delayed twelve time slots by twelve bit shift register 558 so that the data stream on line 566 corresponds to the eight foot range, and this data is passed by AND gate 563 if it is enabled by the opening of switch 570. If switch 570 is closed, however, AND gate 568 will be disabled so that the eight foot data will not be passed. It will be recalled that the manuals are scanned from high to low so that the longer the serial data stream is delayed, the lower are the frequencies of the tones corresponding to the keydown pulses in the data stream. Lines 564 and 572 carry essentially the same data stream, except that the eight foot data stream on line 572 is delayed in time by twelve time slots, which corresponds to one octave.
In order to produce the sixteen foot tones, the sixteen foot Sub tab 574 is closed thereby enabling AND gate 576. The eight foot tones on line 566 are delayed by an additional twelve bits by shift register 578 so that the data stream appearing at the input of AND gate 576 and on its output line 580 is the same data stream that appeared at line 60, but has been delayed in time by twenty-four bits so that it corresponds to the sixteen foot range. Shift registers 558 and 578 are clocked by the multiplex clock train on line 582.
The four foot swell data is passed by AND gate 584 when this gate is enabled by opening switch 570. The data is passed by OR gate 586 and OR gate 588 to the swell data output line 590, which is connected to mixture generator 168. Output line 590 is one of the group of lines indicated generally as 172 in FIG. 1. The swell data at the output of AND gate 568 is carried by line 592 and OR gates 593 and 594 to the delayed swell output line 596, which is also connected to the mixture gating circuit (FIG. 17) forming a portion of mixture generator 168. It will be noted that the data appearing on line 596 is the original data on line 60 but delayed by one octave.
Great manual serial data is brought into coupler block 58 over line 64, and is connected to the Great data output line 598 over line 599 and OR gate 600. Line 598 is connected to the mixture gating circuit in mixture generator 168. The Great data stream passes through twelve bit shift register 602 thereby transforming it down into the eight foot range and is connected to the great data output line 604 by lines 605, 606 and OR gate 607. Line 608 carries the same data for connection to the mixture gating circuit.
The Great data stream at the output 605 of shift register 602 is coupled to the Swell manual collector NOR gate 610 by enabling AND gate 612. This is accomplished by closing the Swell to Great switch 614.
Pedal serial data is brought into coupler 58 over line 62, and is connected to pin 6 of the 4006 eighteen bit shift register 602 by line 616. Shift registers 558, 578 and 602 are eighteen bit shift registers, and since only twelve bits have previously been used for the Swell and Great data, the remaining capacity can be utilized to delay the pedal data without the necessity for using additional shift registers. The output at pin 8 of shift register 602, which is line 618, comprises the data on input line 616 delayed by four bits. This, in turn, is connected to pin 6 of shift register 558 and brought out on pin 8, which is connected to line 620, thereby delaying the pedal data an additional four bits, and line 620 is connected to pin 6 of shift register 578 and brought out on pin 8 to line 622, thereby delaying the pedal data an additional four bits. Thus, the data stream appearing on line 622 and on line 616 is the same data stream on the pedal input 62, but delayed twelve bits, or one octave.
By closing the Swell to Pedal tab switch 626, the pedal data on line 622 will be coupled by AND gate 628 to one of the inputs of swell NOR gate 610. Similarly, by closing the Great to Pedal tab 630, AND gate 631 will be enabled thereby passing the pedal data through OR gate 607 to the Great data output line 604. This also enables AND gate 632 so that the pedal data from line 62 will be passed through OR gate 600 to the Great data output line 598 connected to the mixture gating circuit (FIG. 17). Pedal data is connected to the mixture gating swell data line 590 through OR gate 588 and AND gate 634, when the latter is enabled by closing the pedal to swell switch 626. Switch 614 also enables AND gate 636 so that the Great manual data on line 64 can be coupled to the Swell data output line 590 which is connected to the mixture gating circuit.
Tab generators 76, 120, 128 and 138 receive data either directly or indirectly from the couplers in the form of serial data streams wherein keydown pulses appear in time slots corresponding to the depressed keys of the respective manuals 20, 22 and 24 as well as keydown signals coupled from one manual to another or from one footage to another within a manual. Basically, the tab generators generate the appropriate footages by delaying the incoming data in increments of twelve bits for the octavely related footages, such as four foot, two foot, eight foot and sixteen foot, and by less than twelve bits for the mutations, such as two and two-thirds. In all cases, the incoming data is considered to be nominally in the one foot range so that if it is delayed by five counts it would then be in the one and three-fifths range, if delayed by twelve counts in the two foot range, etc. The incoming data streams are selectively delayed by using shift registers to produce the various footages that are recombined before being connected to the multiplexers/keyers.
For purposes of illustration, only the Great tab generator 128 will be described in detail, although the Swell tab generator 76 and pedal tab generator 120 used basically the same technique for producing the desired footages. Referring now to FIG. 14, which illustrates the Great tab generator 128, the incoming serial data from coupler block 58 on line 604 is delayed twelve bits (one octave) by 4006 shift register 640 to produce at pin 10 on line 606 the two foot Great data stream. The two foot data stream is connected to one of the inputs of AND gate 608 by line 609, and appears on output line 610 if AND gate 608 is enabled by closing the two foot principal tab switch 612. Similarly, this data stream appears on the two foot stopped flute output line 614 if AND gate 616 is enabled by closing the stopped flute two foot tab switch 618.
The two foot input 606 to type 4006 shift register 662 is brought out on pin 9 after being delayed eighteen bits and connected to pin 6 of shift register 640 over line 664. From here it is brought out on pin 9 of shift register 640 after being delayed an additional five bits and is fed to the data input of D-type flip-flop 666 over line 668. Flip-flop 666 delays the data stream an additional one bit so as to produce the eight foot Great tab data stream on line 670. This is connected to line 142 for connection to the chiff, harp and chime tab generator 138 (FIG. 1) and through AND gate 672 to line 674 when the eight foot tab switch 676 is closed. Line 674 is connected to the stopped flute collector. The eight foot Great data on line 678 is passed by AND gate 679 to the eight foot principal collector line 680 when tab switch 682 is closed.
If desired, the two and two-thirds mutation can be generated by connecting pin 13 of shift register 662 to the data input of flip-flop 684 over line 685. This produces an additional delay of five bits to produce the desired mutation.
The four foot stopped flute data stream on line 686 is produced by closing switch 688 thereby enabling AND gate 689 and permitting the twelve bit delayed data from pin 11 of shift register 662 to be passed to line 686. This same data stream will appear on the four foot principal output line 690 by closing switch 692 thereby enabling AND gate 693.
Great tab generator 128 produces on its output lines the stopped flute and principal two foot, four foot, and eight foot data streams, which are essentially the identical data streams but delayed in time depending upon the footage. The eight foot Great data on line 670 is connected to the harp, chiff and chime tab generator 138 over line 142.
When the automatic bass switch 700 is closed, the two foot Great data on line 702 is passed by AND gate 704 to the pedal two foot tab generator 120. The low bit is passed by AND gate 705 when it is enabled by the inverted low data control bit on input 166. In the automatic bass mode, the pedalboard 24 is disabled and the bass note is that which corresponds to the lowest key depressed in the lower two octaves of the Great manual. When the control bit on input 166 signals that this is, in fact, the lowest bit in the Great manual data stream, AND gate 705 is temporarily enabled thereby passing the lowest bit to AND gate 704, which will pass it on to output line 707 if the automatic bass switch 700 is closed. The lowest bit on line 707 is processed by the pedal tab generator 120. In pedal tab generator 120, the automatic bass data is selectively delayed by means of shift registers to produce the one foot, one and one-third foot, two foot, four foot, eight foot or sixteen foot data streams, which are collected together and connected over lines 124 and 126 to the inputs of multiplexer/keyers 98 and 104. The footage generation techniques utilized in the pedal tab generator 120 are essentially the same as those utilized in the Great tab generator 128, which is illustrated in FIG. 14.
FIG. 15 illustrates the principal tab collector for the serial data streams received from the Swell tab generator 76, pedal tab generator 20 and Great tab generator 128. Line 710 carries the sixteen foot pedal data, which is the two foot data on line 24 of coupler 58 (FIG. 13) that has been delayed by forty-eight bits (four octaves). This is passed to output line 716 when AND gate 717 is enabled by closing the sixteen foot tab switch 718. The eight foot pedal data on line 711 is connected to output line 719 by closing the eight foot switch 720, which enables AND gate 722, and is connected to output line 724 by AND gate 726, which is enabled by closing switch 718 and the appropriate control signal on the transpose fold line 728.
Four foot pedal data on line 712 is connected to output line 730 by enabling AND gate 732, which is accomplished by closing switch 733. The closing of pedal mixture switch 736 enables AND gates 738 and 740, thereby passing the two foot and one and one-third foot data streams on lines 713 and 714 to output lines 741 and 742.
The two foot output line 610, the four foot output line 690 and the eight foot output line 680 from Great tab generator 128 (FIG. 14) are connected to three of the inputs of OR gate 744. Also connected thereto are the output lines 746 and 748 for the two foot and four foot data streams, respectively, from Swell tab generator 76 (FIG. 1). OR gate 744 collects these data streams and produces a single data stream on line 750, which is one of the inputs of OR gate 752. The other inputs of OR gate 752 are lines 716, 719, 724, 730, 741 and 742, which carry the pedal tab data streams. OR gate 752 collects these data streams and produces a single principal data stream on line 754, which is connected to the appropriate input of the principal keyer/demultiplexer bank 104 (FIG. 1). A keyer bank of this type is illustrated in detail in FIGS. 2-6. Although not illustrated in a separate block in FIG. 1, the collector of FIG. 15 is essentially a portion of the principal keyer/multiplexer bank 104. A somewhat similar collector circuit is part of the flute keyer/multiplexer bank 98.
Line 142 from Great tab generator 128 (FIG. 14) connects to the input of the chiff, harp and chime generator block 138. Harp data is produced by shifting the Great data on line 142 such that it is in the four foot range, and this is fed to demultiplex percussion block 46 over line 144. Chime data is produced by delaying the highest note in the data stream on line 142 in three shift registers such that notes five bits, twelve bits and twenty bits lower than the note played are produced in parallel. For example, if C is played, G in the octave below it, C an octave lower, and E below that will be played. A similar technique is disclosed in allowed patent application Ser. No. 000,158, filed Jan. 2, 1979, which application is expressly incorporated herein by reference. This chime data is fed to multiplex percussion block 46 over line 144.
Chiff is played together with the eight foot tab from the Great manual 22, and this is two and two-thirds away from the eight foot data pulse. The chiff data is also fed to multiplex percussion block 46. If desired, the chiff, harp and chime data can be prioritized so that if the chime tab is actuated, harp and chiff will not play, if the harp tab is actuated chiff will not play, thereby assigning chiff the lowest priority.
Multiplex percussion circuit 46 is illustrated in detail in FIG. 16, and functions to produce a burst of data to simulate the percussive nature of the harp, chime and chiff sounds. The latch command from Great multiplexer 26 is brought into the multiplex percussion generator 46 on line 766 to the data input of flip-flop 767, which delays the latch pulse by one clock cycle. The delta data pulse from great multiplexer 26 is brought in on line 48, and this pulse is typically ten milliseconds wide. The data stream from chiff, harp and chime generator 138 on line 144 is connected to the data input of flip-flop 768, and this delays the data stream by one clock cycle. Since both the latch command and the data stream are delayed by the same amount, the percussion keyers 148 are not affected. The purpose of the delay is to eliminate the effect of minute delays which are caused upstream from the system.
The data stream on the Q output line 769 of flip-flop 768 is connected to one of the inputs of AND gate 770 and one of the inputs of NOR gate 771. The outputs of gate 770 and 771 are connected to the inputs of NOR gate 772, and these three gates function as an exclusive OR circuit. Line 773 is connected to the Q output of sixty-four bit shift register 774, and is connected to the other inputs of AND gate 770 and NOR gate 771. Sixty-four bit shift register 774 and sixty-four bit shift register 776 are connected in series and are clocked by the multiplex clock train on line 778. Shift register 776 and 774 together form a one hundred twenty-eight bit storage shift register, which is exactly the length of two scans of great manual 22.
The output of NOR gate 772 is connected over line 780 to one of the inputs of AND gate 781, the other input of which is connected to line 48. AND gate 781 enables the serial data from the Q output of flip-flop 768 if it is enabled by the output of exclusive OR arrangement 782. This occurs only when the serial data on lines 769 is different from the serial data which is being recirculated by shift registers 776 and 774. The necessity for this arises because of the face that the delta data pulse, which is much wider than a single clock cycle, is produced each time a new key is depressed. The purpose of percussion generator 46 is to produce a burst of data for each new key which is depressed and produce this burst for the width of the delta data pulse. If an earlier depressed key is still being held when a new key is depressed, and if data for both of these keys is outputed to the keyers 148, the first depressed key would sound again. In order to prevent this, incoming new data from the Q output of flip-flop 768 is compared with recirculating data in shift register 776 and 774, which data is representative of all keys presently depressed at any time, so that the new data is separated out for transmission to the keyers 148.
AND gate 784 is connected to the output of AND gate 781 by line 785, and has its other input 786 connected to delta data line 48. Thus, AND gate 784 is enabled only during the ten millisecond delta data pulse, and all new data passed by AND gate 781 will be passed to output line 146 on each alternate scan of the great manual 22. This, in effect, produces a burst of new data which, when it is utilized to control the sustain type keyers 148 described earlier, produces a percussive effect.
The delta data pulse on line 48 is inverted by inverter 788 so as to disable AND gate 789, which gate is connected to receive the serial data from the output of AND gate 781 by line 790. At the end of the delta data pulse, however, And gate 789 is then enabled to pass the data stream from AND gate 781 over line 792 to the input of NOR gate 793. The output of NOR gate 793 is inverted by inverter 794 and fed to the data input 795 of shift register 776. This arrangement loads the new data into shift register 776 and 774 for recirculation. It will be noted that the Q output 796 of shift register 774, after being gated by AND gate 798, is also connected to the input of NOR gate 793 for recirculation of the data already in shift registers 776 and 774.
Recirculation of the data in shift registers 776 and 774 is accomplished by AND gate 798, which, due to the presence of inverter 800, is enabled each time there is a match between the new data from flip-flop 768 and the output data from shift register 774 on line 801. Thus, exclusive OR arrangement 782 enables AND gate 798 for recirculation whenever there is a match between the data, and enables AND gate 781 for the gating of new data whenever there is no match between such data and the recirculated data. A new data burst will be produced for each new key which is depressed, and the sustaintype keyers 148 will cause the sound to decay out with a percussive envelope independently of the length of time the keys are held down.
The mixture generator 168 will now be described, with reference to FIG. 17. Swell data from coupler 58 (FIG. 13) is brought into the mixture gating and generation block 168 over line 590, and the same data which has been delayed by twelve bits (one octave) is brought in on line 596. Similarly, the Great data stream from coupler 58 is brought into circuit 168 on line 598, and the same data which is delayed by one octave is brought in on line 608. AND gates 804 and 805 are enabled when the Swell mixture tab 806 is closed, thereby gating the delayed Swell data to OR gate 807 and the normal Swell data to OR gate 808. When Great mixture tab 809 is closed, AND gates 810 and 811 are enabled thereby passing the delayed Great data to OR gate 807 and the normal Great data to OR gate 808.
As mentioned earlier, it is customary to produce mixtures in different inversions depending on the octave in which the key or keys are depressed. For the top octave extending between high C and the C below high C, the unison (the depressed key) forms the outside notes and the mutation (two and two-thirds, for example) forms the inner note. Assuming the depressed key to be nominally in the one-half foot range, the lower unison is in the four foot range, the upper unison is in the two foot range, and the mutation is two and two-thirds foot. For the next lower octave extending from B to the next lower C, the unison forms the inner note and the mutations the outside note. Thus, the inner note is at two foot, the upper mutation is at one and one-third foot, and the lower mutation is at two and two-thirds foot. In this case, assuming that a C key is depressed, G, C, and G notes will be produced, in that order.
For the next octave extending from the next lower B to the C below it, the unisons again form the outside notes and the mutation the inside note. The footages for the unisons are one foot and two foot, and for the mutation one and one-third foot. For the lowest two octaves, the unison forms the inner note and the mutations the outside note, wherein the unison is at one foot and the mutations at one and one-third foot and two-thirds foot, respectively.
The data streams for the upper octave and for the third octave are routed to the inputs of OR gate 812, the output of which connects to three serially arranged shift registers 813, 814 and 815, which introduce delays of twelve bits, five bits and seven bits, respectively. The outputs 816 from shift registers 813, 814 and 815 form the unison and mutation data streams for these octaves. In a similar fashion, the Swell and Great data streams for the second highest octave and for the lowest two octaves are connected to the inputs of OR gate 817, the output of which is connected to three serially connected shift registers 818, 819 and 820, which introduce delays of five bits, seven bits and five bits, respectively. The outputs 821 of shift registers 818, 819 and 820 carry the unison and mutation data streams, and, like outputs 816, are collected and connected to the principal tab collector (FIG. 15).
If the depressed key is in the uppermost thirteen notes of the Swell or Great manual, it is necessary to delay the data stream, which is nominally in the one-half foot range, by twenty-four bits to produce the two foot data stream, and then delay this data stream by an additional five bits to produce the two and two-thirds foot data stream, and then delay this data stream by an additional seven bits to produce the four foot data stream. This can be accomplished by routing the delayed Swell data stream and delayed Great data stream on the outputs of AND gates 804 and 810, respectively, through AND gate 822. Because the data stream has already been delayed by a full octave (twelve bits) in the coupler block 58, shift register 813 will produce the additional twelve bits of delay for a total of twenty-four bits thereby producing the two foot data stream. Shift register 814 will delay this by an additional five bits to produce the two and two-thirds foot data stream, and shift register 815 will delay it an additional seven bits for the four foot data stream. AND gate 822 is enabled when RS flip-flop 823 is in its set position, and flip-flop 823 is set by the output of AND gate 824, which occurs at time K1, T6. At this time, the K1 line of multiplexer 26 (FIG. 7) is enabled, and the T6 line of receiver shifter 70 (FIG. 10) is enabled. Due to the fact that the data on line 596 is delayed two counts in the multiplexer and then by one octave, AND gate 822 will not be enabled until the fifteenth multiplexer count.
On the multiplexer count corresponding to the twenty-sixth note, which is K3, T3, AND gate 826 will reset RS flip-flop 823 and, because of the logic 1 on line 827, will set RS flip-flop 828. The output line 829 from RS flip-flop 828 is connected to the inputs of AND gates 830 and 831, and enables both of these AND gates simultaneously. The output of OR gate 808 carries the undelayed Swell and Great data and is connected to the other input of AND gate 830. Similarly, the output of OR gate 807 carries the delayed Swell and Great data and is connected to the other input of AND gate 831. At the same time, the undelayed swell and great data are passed by AND gate 830, and this corresponds to the third octave of keys.
The output of AND gate 831 is gated by OR gate 817 to shift registers 818, 819 and 820, which delay the data stream by five bits, seven bits and five bits, respectively. Because the data stream was initially delayed by twelve bits, however, the effect of shift register 818 is to delay it seventeen bits, thereby producing the one and one-third, two foot and two and two-thirds foot data streams for the mutation-unison-mutation notes.
Shift registers 813, 814 and 815 delay the data stream corresponding to the third octave by twelve bits, five bits and seventeen bits. This produces the one foot, one and one-third foot and two foot data streams corresponding to the unison-mutation-unison notes.
At count K4 T7, which corresponds to the thirty-seventh key, AND gate 833 is enabled thereby resetting flip-flop 828 and setting RS flip-flop 834. This enables AND gate 835, which gates the undelayed Swell and Great data corresponding to the lower two octaves of the manual through OR gate 817 into shift registers 818, 819 and 820. These shift registers delay the data by five bits, seven bits and five bits, respectively, thereby producing the two-thirds foot, one foot and one and one-third foot data streams. These, in turn, correspond to the mutation-unison-mutation notes of the lower two octaves. AND gate 835 is enabled until count T7 K7 whereupon AND gate 836 resets flip-flop 834 and no further data is passed by AND gate 835.
FIG. 18 illustrates a preferred shift register arrangement for providing the necessary delay to generate the mixture data streams. Shift registers 840 and 842 are substituted for shift registers 813, 814 and 815 in FIG. 17, and are connected to the output 843 of OR gate 812. Shift registers 840 and 842 are type 4006 shift registers that are clocked by the multiplex clock train on line 844 and produce twelve bit, five bit and seven bit delays on output lines 845, 846 and 847, respectively. Type 4006 shift register 848 takes the place of shift registers 818, 819 and 820 in FIG. 17, and is connected to the output line 849 from OR gate 817. Shift register 848 produces the required five bit, seven bit and five bit delays on output lines 850, 851 and 852. The outputs of shift registers 840, 842 and 848 are collected together by OR gate 853 the output line 174 of which is connected to the principal keyer/multiplexer bank 104.
With reference now to FIG. 19, the transposer block 856, which is illustrated generally in FIG. 1A, will be described in detail. The transposer enables the data to be changed automatically to a different pitch by altering the time at which the latch pulse is transmitted to the keyer/multiplexers 86, 98, 104, 92 and 148. In the past, it has generally been the practice to delay the data stream to accomplish transposition, but this has often necessitated a very long shift register in the case where wraparound of the data occurs. For example, if the lowest note on the organ is transposed lower in frequency, it would be necessary to delay the pulse corresponding to this note by an entire scan of the keyboard so that it would appear in its proper transposed position in the octave above the lowest octave of the organ.
In FIG. 19, the data disable pulse is brought in on line 858, which connects to the Q output of flip-flop 530 in the multiplex control block 50 illustrated in detail in FIG. 12. It will be recalled that data is passed only during alternate scans of the manuals, and when flip-flop 530 activates line 858, AND gates 859 and 860 in FIG. 19 will be enabled to pass the K7 and K6 lines from great multiplexer 26 (FIG. 7).
If no transposition is selected by player operated selector switch 861, which corresponds to C, AND gate 867, which has as its inputs the K6 T7 lines, will produce on line 862 a pulse at time K6 T7, which is the normal time frame in which the demultiplex latch pulse should be produced. The data stream will arrive at the keyer/demultiplexers 86, 98, 104, 92 and 148 at the normal time so that the data produced by depression of the keys of the manuals will correspond to the note names of those keys.
AND gates 863, 864, 865, 866, 868, 869, 870, 871 and 872 are connected to various combinations of the T and K lines as illustrated in FIG. 19 so that they will be enabled at times earlier or later than the K6 T7 time. For example, AND gate 868 will be enabled at K6 T6, which is a time one time frame earlier than the normal latch time frame of K6 T7, and has the effect of causing the data stream to advance one less time frame further in the keyers. This transposes the entire data stream by one-half step lower in frequency. Similarly, AND gate 866 has as its inputs K7 T1, which occurs two time frames after the K6 T7 latch time. This has the effect of delaying the latch command by two time frames thereby causing the data stream to move two time frames further along in the keyers. This produces a transposition of two half steps higher in frequency. Rather than utilizing a separate AND gate for producing the enabling pulse at the time K0 T0, a different technique has been utilized. This is because of timing and synchronization difficulties sometimes experienced when making the transition between both a new T number and a new K number. The output of AND gate 867 is delayed one bit by flip-flop 874, which is clocked by the multiplex clock train on line 875. The output 876 of flip-flop 874, then, carries a pulse which synchronous with the K7 T0 time.
The outputs of AND gates 863, 864, 865, 866, 867, 868, 869, 870, 871, 872 and line 876 form the inputs of AND gates 877, 878, 879, 880, 881, 882, 883, 884, 885 and 886. Only one of these AND gates is enabled, however, by selector switch 861, so that only one of the outputs from AND gates 863-872 or line 876 will be connected to the collecting OR gate 887.
It will be noted that AND gates 884 and 885 are collected by OR gate 888 and then connected to OR gate 887 over line 889.
Momentary contact switch 890 clocks divide-by-two flip-flop 891 which has its Q output connected to line 892 and its Q output connected to one of the inputs of AND gate 893 over line 894. The inversion of the output is inverted by inverter 895 and connected to one of the inputs of AND gate 896. When momentary switch 890 is pressed once, flip-flop 891 disables AND gate 893 so that the normal latch pulse on 862 is blocked. At the same time, the inverted output to AND gate 896 enables the output 898 from OR gate 887 to pass to collecting OR gate 899. The output 900 of OR gate 899 is connected to the latch input line (FIG. 2) of each of the keyers 86, 98, 104, 92 and 148 (FIG. 1). When switch 890 is pressed again, flip-flop 891 assumes its alternate state thereby disabling AND gate 896 to prevent the passage of the transposed latch pulse, and enables AND gate 893 to permit the normal K6 T7 pulse to be connected to the input of OR gate 899 over line 901. LED circuit 902 provides a visual indication when the transposition circuit is actuated.
With reference now to FIG. 19A, the fold circuitry associated with transposer 856 will be described. Output lines 903 from transposer 856 (FIG. 19) will be activated when selector switch 861 is turned to any position indicating that the transposition will be in the flat direction. This means that switch 861 is in the B, A♯, A, G♯ or G positions. When transposing flat, if the sixteen foot tab is on, low C will be lost if the data is transposed one time frame flat, low C and C♯ will be lost if it is transposed two time frames, low C, C♯ and B will be lost if it is transposed three time frames, etc. This is because the data will not have sufficient time to be advanced completely into the demultiplexer keyers 86, 98, 104, 92 and 148 before the transposed latch command occurs.
The data which would otherwise not fully enter the keyers before latch command is injected into the data stream one octave higher by the transposer fold circuit 904 in FIG. 19A. Thus, if the data stream is transposed one time frame flat and the low C key is depressed with the sixteen foot tab on, a pulse will be injected into the data stream in the C position in the next octave, which is the position of the transposed note exactly one octave higher. If the data stream is transposed two time frames flat, this pulse would still be injected in the data stream in the C position in the next octave. If both the low C and C♯ keys in the lowest octave are depressed, two pulses would be injected for the situation where the data stream is transposed two time frames flat, one pulse in the C position and one pulse in the C♯ position in the next highest octave.
This is accomplished by providing a series of five AND gates 905, 906, 907, 908 and 909, the inputs of which are the K5 line and the T6, T5, T4, T3 and T2 lines, respectively. AND gates 905-909 produce pulses on their outputs at the K-T times indicated, and their outputs are gated to collecting OR gates 910, 911, 912 and 913 to output line 914 depending on whether the respective AND gates 915, 916, 917, 918 and 919 are enabled. Line 914 is connected to each of the tab generator collector portions, an example of which is shown in FIG. 15, and causes AND gate 756 (FIG. 15) to produce an output on its output line 758 if the sixteen foot tab switch 718 is also closed. This enables AND gate 716 to pass those pulses in the eight foot data stream on line 711 which correspond to the enabling control pulses on line 728. The enabling control pulses are selected such that they occur twelve bits ahead of those time frames below low C, which are lost if the data stream is transposed flat. For example, if the data stream is transposed flat by one time frame, which is achieved by turning selector switch 861 to the B position, and low C is depressed with the sixteen foot tab actuated, this tone would not be played. To enable the tone to be heard, AND gate 726 is enabled so that the data stream on the eight foot line, which is the normal data stream, will be gated to the output of AND gate 726 only during that time frame in which AND gate 726 is enabled. By selecting the proper K and T driver lines, AND gate 726 will be enabled in exact coincidence with the played note on the eight foot line 711. Since line 711 carries the entire data stream regardless of whether the eight foot tab switch 720 is depressed, the single pulse passed by enabled AND gate 726 will be played in the eight foot range. It should be noted that similar injection circuitry is utilized in the other tab generators 76, 120, 128 and 168 as well.
If the data stream is transposed two time slots lower, then both AND gates 905 and 906 will produce output pulses at the K5 T6 and K5 T5 times which correspond to the time frames associated with the lost keys played one octave higher. In this case, this would correspond to the C and C♯ keys in the lowest octave of the manual. Again, AND gate 726 would be enabled during these two time frames to pass the serial data stream on line 711, which, if it contained keydown pulses in these two time frames, would produce the C and C♯ notes in the eight foot range.
The K5 line 934 is gated together with the data disable line 935 by AND gate 936 so that it is effective only during the alternate scans of the manuals. Transpose line 892 from FIG. 19 enables AND gates 920, 921, 922, 923 and 924, the other inputs of which are connected to the transpose fold control lines 925, 926, 927, 928 and 929, respectively, which are indicated generally as 903 in FIG. 19. A control signal on line 929, which is connected thereto by positioning selector switch 861, indicates transposition flat by one time frame. Similar control signals on lines 928, 927, 926 and 925 indicate transposition flat by two time frames, three time frames, four time frames, and five time frames, respectively.
The outputs of AND gates 920-924 are collected together by OR gates 930, 931, 932 and 933 in a priority fashion so that if a control signal is present on any of lines 925-929, the series connected OR gates 933-930 will enable all of the AND gates 915-919 corresponding to a lower degree of transposition. For example, if AND gate 923 is enabled, OR gate 931 will produce an enabling signal on AND gate 916 and also transmit an enabling signal through OR gate 930 to AND gate 915. An output from OR gate 932 will enable AND gate 917, and also enable AND gates 915 and 916 through OR gates 930 and 931, respectively. Thus, if selector switch 861 is moved to the G position, thereby causing transposition of five time frames flat, each of AND gates 915-919 will be enabled and five time slots will be passed through AND gate 756 in FIG. 15 from the eight foot data line 711.
The choice of T and K lines is completely dependent on the multiplexing sequence that is employed. In this sense, the selection of the K and T lines for transposition, latching, transpose fold, and the like depends on their particular relationship to the data stream. The time frames in the data stream could be numbered sequentially or in pitch and octave format. All that is necessary is to determine at which point in the data stream the particular control pulse or pulses are to be generated to produce the desired effect.
The automatic bass circuit 160 is illustrated in FIG. 20 together with portions of the great tab generator 128 and pedal tab generator 120. As discussed earlier, one of the features of the present invention is that of an automatic bass wherein the pedalboard 24 is deactivated and the lowest note played in the lowest two octaves of the great manual 22 is coupled to the pedal tab generator for voicing as if it were being played on the pedalboard itself. This feature enables a person able to play another keyboard instrument, such as a piano, to play an organ, without the necessity of learning to manipulate the pedalboard.
Great data from the multiplex control block 50 (FIG. 12) is brought into the automatic bass circuit on line 164, and this data is in the one-half foot range. It passes through inverter 940 to one of the inputs of AND gate 941. Count decoder 942 decodes the TK counts to open a window at K4 T7 by producing an output from activated AND gate 943 to set RS flip-flop 944. On count K2 T7, which is exactly twenty-four bits or two octaves later, the output of AND gate 946 goes high thereby resetting flip-flop 944. When flip-flop 944 is set, AND gate 941 is enabled to pass great data from inverter 940, and when flip-flop 944 is reset, AND gate 941 is disabled and will block great data from inverter 940.
A 4520 dual four bit counter 948 is clocked at the multiplex clock rate by the pulse train on multiplex clock line 950. This counter counts down from count 256, and its outputs are decoded by inverters 952 and NAND gate 954 such that it generates a pulse on output line 956 exactly at count 232. Counter 948 is reset, however, by the output 958 of AND gate 941, which carries the Great serial data stream within the lowest two octaves of great manual 22 as determined by window circuit 960. Each time that a data pulse appears on line 958, counter 948 will be reset and begin counting down from count 256.
This means that counter 948 always generates a pulse on line 956 exactly twenty-four counts, or two octaves of multiplex count pulses, after it is preset to its starting count of 256. Thus, if three keys in the lowest two octaves of the Great manual are held depressed, when the highest depressed key is scanned, counter 948 will be reset to count 256. When the next count is detected, counter 948 will again be reset to count 256. Because the lowest two octaves are only twenty-four bits wide, the first and second scanned keys must be less than twenty-four keys apart so that counter 948 will again be reset. When the third key is scanned, which key is the lowest depressed key in the lower two octaves of Great manual 22, counter 948 will again be reset, and will produce an output pulse on line 956 exactly twenty-four bits later. Since the last-mentioned key is the lowest key depressed on the manual, no other keydown pulses will be present on line 164, which would reset counter 948. When the last key in the Great manual 22 is scanned, window circuit 960 will close thereby disabling AND gate 941 and preventing the further passage of data from line 164.
The pulse on line 956 connected to the output of AND gate 954 is exactly two octaves lower than the last keydown pulse which reset counter 948, and is therefore exactly two octaves lower than the lowest depressed key on the Great manual. It will be recalled that the incoming data on line 164 is in the one-half foot range, so that delaying this data by two octaves will place it in the two foot range, which is the desired footage for injection into the pedal data stream.
The lower portion of FIG. 22 illustrates a portion of the Great tab generator 128 (FIG. 14). The enabling pulse on line 956 is connected to the input 166 of converter 963, the output of which enables AND gate 705. The Great two foot data on line 702 is therefore passed by AND gate 705 to the input of AND gate 704, the latter being enabled by closing the automatic bass switch 700.
Pedal data on line 964 of pedal tab generator 120 is in the one foot range, and this is delayed by twelve bits by shift register 965 to produce the two foot output on line 713. The two foot automatic bass output on line 968 from AND gate 704 is added to the two foot pedal data on line 970 at the inputs of OR gates 971, and this is delayed by shift register 972 to produce the four foot, eight foot and sixteen foot outputs on lines 712, 711 and 710, respectively. This data is then collected and connected to the inputs of flute keyers 98 and the principal keyers 104 wherein it is demultiplexed.
While this invention has been described as having a preferred design, it will be understood that it is capable of further modification. This application is, therefore, intended to cover any variations, uses, or adaptations of the invention following the general principles thereof and including such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and fall within the limits of the appended claims. | 4y
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CROSS REFERENCE TO OTHER APPLICATIONS
[0001] This application claims the benefit of and incorporates by reference U.S. Provisional Application No. 61/289,762 filed Dec. 23, 2009.
FIELD OF THE INVENTION
[0002] The invention is directed to the field of tire manufacturing and tire construction.
BACKGROUND OF THE INVENTION
[0003] Tires are typically manufactured on a cylindrical tire building drum with the tire components assembled in layers upon the drum. The carcass or load carrying member of the tire is typically made from one or more layers of ply which are cut and then spliced upon the tire building drum. The ply fabric is formed from a plurality of reinforcements which are coated in rubber prior to application to the drum.
[0004] In the early 1900s, bias tires were made of two or more layers of ply wherein the reinforcements were angled with the circumferential direction. The cord angle of the ply layer provided reinforcement in both the radial and circumferential direction. One advantage to bias tires is that since the cords are oriented at an angle, they have strength in the circumferential direction and the radial direction. The disadvantage to bias tires is that the cords of the ply were not placed in the most efficient path possible, resulting in energy loss.
[0005] In the 1970s, the radial tire became the industry standard. For the radial ply, the cords have a 90 degree angle with the circumferential direction, so that the cords are normal to the bead, running from bead to bead. One advantage to radial tires is that the cords are oriented efficiently, i.e., the shortest distance between two points. One disadvantage to radial tires is that they have low strength in the circumferential direction. Thus as a radial tire rolls through its contact patch, the tire bulges due to the lack of strength in the circumferential direction. The tire bulge is a source of energy loss which results in increased rolling resistance.
[0006] The next generation tire or tire of the future will most likely be a low rolling resistance tire due to the consumer demand for more fuel efficient vehicles. The inventors of this application have discovered that a geodesic tire could represent a viable solution to a low rolling resistance tire due to its unique properties. Geodesic tires are tires whose ply cord paths are geodesic lines on the tire surface, conforming perfectly to the geodesic law for an axisymmetric surface that ρ cos α=ρ 0 cos α 0 . The result of the geodesic path is that the cord tension is uniform over the entire cord path, and that shear stresses due to inflation pressure are zero. A true geodesic path is the shortest distance between two points on a surface.
[0007] While the math of geodesic tires is described by Purdy, efforts to build a true geodesic tire have been elusive. Most of the efforts have been focused on building a geodesic tire flat on a tire building drum so that the cords would pantograph into the geodesic position upon formation into the final tire shape. This approach has not been proven to result in a geodesic tire. Thus for the foregoing reasons, it is desired to provide an improved method and apparatus for forming a geodesic tire without the above described disadvantages.
Definitions
[0008] “Aspect Ratio” means the ratio of a tire's section height to its section width.
[0009] “Axial” and “axially” means the lines or directions that are parallel to the axis of rotation of the tire.
[0010] “Bead” or “Bead Core” means generally that part of the tire comprising an annular tensile member, the radially inner beads are associated with holding the tire to the rim being wrapped by ply cords and shaped, with or without other reinforcement elements such as flippers, chippers, apexes or fillers, toe guards and chafers.
[0011] “Belt Structure” or “Reinforcing Belts” means at least two annular layers or plies of parallel cords, woven or unwoven, underlying the tread, unanchored to the bead, and having both left and right cord angles in the range from 17° to 27° with respect to the equatorial plane of the tire.
[0012] “Bias Ply Tire” means that the reinforcing cords in the carcass ply extend diagonally across the tire from bead-to-bead at about 25-65° angle with respect to the equatorial plane of the tire, the ply cords running at opposite angles in alternate layers.
[0013] “Breakers” or “Tire Breakers” means the same as belt or belt structure or reinforcement belts.
[0014] “Carcass” means a layer of tire ply material and other tire components. Additional components may be added to the carcass prior to its being vulcanized to create the molded tire.
[0015] “Circumferential” means lines or directions extending along the perimeter of the surface of the annular tread perpendicular to the axial direction; it can also refer to the direction of the sets of adjacent circular curves whose radii define the axial curvature of the tread as viewed in cross section.
[0016] “Cord” means one of the reinforcement strands, including fibers, which are used to reinforce the plies.
[0017] “Inner Liner” means the layer or layers of elastomer or other material that form the inside surface of a tubeless tire and that contain the inflating fluid within the tire.
[0018] “Inserts” means the reinforcement typically used to reinforce the sidewalls of runflat-type tires; it also refers to the elastomeric insert that underlies the tread.
[0019] “Ply” means a cord-reinforced layer of elastomer-coated cords.
[0020] “Radial” and “radially” mean directions radially toward or away from the axis of rotation of the tire.
[0021] “Sidewall” means a portion of a tire between the tread and the bead.
[0022] “Laminate structure” means an unvulcanized structure made of one or more layers of tire or elastomer components such as the innerliner, sidewalls, and optional ply layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The invention will be described by way of example and with reference to the accompanying drawings in which:
[0024] FIG. 1 is a perspective view of a tire carcass having geodesic cords;
[0025] FIG. 2 is a close up view of the cords of the tire carcass in the crown area;
[0026] FIG. 3 is a close up view of the cords of the tire carcass in the bead area;
[0027] FIG. 4A illustrates the initial cord winding on a tire blank in a geodesic pattern;
[0028] FIG. 4B illustrates the cord winding on a tire blank of FIG. 5 a after multiple passes;
[0029] FIG. 5 illustrates various geodesic curves;
[0030] FIG. 6 illustrates a front view of a tire carcass having geodesic cords of the present invention;
[0031] FIG. 7 illustrates a side view of the carcass of FIG. 7 ;
[0032] FIGS. 8 and 9 illustrate a close up perspective view of the bead area of the carcass of FIG. 7 ;
[0033] FIGS. 10-11 illustrate a first embodiment of an apparatus for laying ply on a tire blank;
[0034] FIG. 12 illustrates a second embodiment of an apparatus for laying ply on a tire blank;
[0035] FIG. 13 illustrates a cross-sectional view of a passenger tire of the present invention;
[0036] FIG. 14 illustrates various test tire performance for normalized spring rate;
[0037] FIG. 15 illustrates various test tire performance for normalized spring rate for aramid ply;
[0038] FIG. 16 illustrates rolling resistance data for a control and aramid geoply tire;
[0039] FIG. 17 illustrates rolling resistance data for a control and polyester geoply tire; and
[0040] FIG. 18 illustrates a cross-sectional view of a prior art radial passenger tire with a tire of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0041] A cross-sectional view of a tire having geodesic cords is shown in FIG. 13 . As shown, the tire 300 may be representative of a passenger tire and comprises a pair of opposed bead areas 310 , each containing one or more column beads 320 embedded therein. As compared to a tire of the same size, the tire of the present invention has a greatly reduced bead due to the carcass configuration, as described in more detail, below. The tire 300 may further comprises sidewall portions 316 which extend substantially outward from each of the bead area 310 in the radial direction of the tire. A tread portion 330 extends between the radially outer ends of the sidewall portions 316 . Furthermore, the tire 300 is reinforced with a carcass 340 toroidally extending from one of the bead areas 310 to the other bead area 310 . A belt package 350 is arranged between the carcass 340 and the tread.
[0042] FIGS. 1-3 illustrate the tire carcass 340 of the present invention wherein the cords are arranged in geodesic lines. As shown in FIG. 2 , the crown portion 341 of an exemplary passenger tire of size 225 60R16 has spaced apart plies with the angle of about 48 degrees (which varies depending upon the overall tire size). As shown in FIG. 3 , the bead area 342 of the tire has closely spaced cords with the cords tangent to the bead. Thus the ply angle continuously changes from the bead core to the crown. A geodesic path on any surface is the shortest distance between two points or the least curvature. On a curved surface such as a torus, a geodesic path is a straight line. A true geodesic ply pattern follows the mathematical equation exactly:
[0000] ρ cos α=ρ 0 cos α 0
[0043] wherein ρ is the radial distance from the axis of rotation of the core to the cord at a given location;
[0044] α is the angle of the ply cord at a given location with respect to the mid-circumferential plane;
[0045] ρ 0 is the radial distance from the axis of rotation of the core to the crown at the circumferential plane, and α 0 is the angle of the ply cord with respect to the tread centerline or midcircumferential plane.
[0046] FIG. 5 illustrates several different ply path curves of a tire having geodesic cords. One well known embodiment of a geodesic tire is the radial tire and is shown as curve 4 , wherein the cords have an angle a of 90 degrees with respect to the circumferential plane. Curves 1 , 2 and 3 of FIG. 5 also illustrate other geodesic cord configurations. Curve 1 is a special case of a geodesic cord pattern wherein the cord is tangent to the bead circle, and is referred to herein as an orbital ply. FIGS. 4A-4B illustrate a carcass 340 having an orbital ply configuration and in various stages of completion. For curve 1 of FIG. 5 , the following equation applies:
[0047] At ρ=ρbead, the angle α is zero because the cords are tangent to the bead.
[0000] α=cos −1 (ρ bead/ρ)
[0048] FIGS. 6-9 illustrate a first embodiment of a green tire carcass of the present invention. The tire is illustrated as a passenger tire, but is not limited to same. The cords of the carcass are arranged in a geodesic orbital pattern wherein the cords are tangent to the bead radius of the tire. The close proximity of the cords results in a very large buildup of cord material in the bead area. In order to overcome this inherent disadvantage, the inventors modified the ply layup as described in more detail, below.
Apparatus
[0049] In a first embodiment of the invention, the tire 300 having a carcass with geodesic ply is formed on a core 52 . The core may be in the shape of a cylinder such as a tire building drum, but is preferable in the shape of the final tire. The core has a first end, a second end and a outer core surface located between the first end and the second end. The outer core surface is preferably shaped to closely match the inner shape of the tire. The core may be rotatably mounted about its axis of rotation and is shown in FIGS. 10 and 11 . The core may be collapsible or formed in sections for ease of removal from the tire. The core may also contain internal heaters to partially vulcanize the inner liner on the core. The core may be optionally disposable.
[0050] Next, an inner liner 305 is applied to the core. The inner liner may be applied by a gear pump extruder using strips of rubber or in sheet form or by conventional methods known to those skilled in the art. An optional bead, preferably a column bead 320 of 4 or more wires may be applied in the bead area over the inner liner.
[0051] Next, a strip of rubber having one or more rubber coated cords 2 is applied directly onto the core over the inner liner as the core is rotated. With reference to FIGS. 10-11 , a perspective view of an apparatus 100 in accordance with the present invention is illustrated. As shown the apparatus 100 has a guide means which has a robotic computer controlled system 110 for placing the cord 2 onto the toroidal surface of core 52 . The robotic computer controlled system 110 has a computer 120 and preprogrammed software which dictates the ply path to be used for a particular tire size. Each movement of the system 110 can be articulated with very precise movements.
[0052] The robot 150 which is mounted on a pedestal 151 has a robotic arm 152 which can be moved in preferably six axes. The manipulating arm 152 has a ply mechanism 70 attached as shown. The robotic arm 152 feeds the ply cord 2 in predetermined paths 10 . The computer control system coordinates the rotation of the toroidal core 52 and the movement of the ply mechanism 70 .
[0053] The movement of the ply mechanism 70 permits convex curvatures to be coupled to concave curvatures near the bead areas thus mimicking the as molded shape of the tire.
[0054] With reference to FIG. 11 , a cross-sectional view of the toroidal core 52 is shown. As illustrated, the radially inner portions 54 on each side 56 of the toroidal mandrel 52 have a concave curvature that extends radially outward toward the crown area 55 of the toroidal mandrel 52 . As the concave cross section extends radially outward toward the upper sidewall portion 57 , the curvature transitions to a convex curvature in what is otherwise known as the crown area 55 of the toroidal mandrel 52 . This cross section very closely duplicates the molded cross section of a tire.
[0055] To advance the cords 2 on a specified geodesic path 10 , the mechanism 70 may contain one or more rollers. Two pairs of rollers 40 , 42 are shown with the second pair 42 placed 90° relative to the first pair 40 and in a physical space of about one inch above the first pair 40 and forms a center opening 30 between the two pairs of rollers which enables the cord path 10 to be maintained in this center. As illustrated, the cords 2 are held in place by a combination of embedding the cord into the elastomeric compound previously placed onto the toroidal surface and the surface tackiness of the uncured compound. Once the cords 2 are properly applied around the entire circumference of the toroidal surface, a subsequent lamination of elastomeric topcoat compound (not shown) can be used to complete the construction of the ply 20 .
[0056] The standard tire components such as chafer, sidewall, and tread may be applied to the carcass and the tire cured in a conventional mold. The tire may further include an optional bead having a significantly reduced area and weight. One example of a bead suitable for use with the tire of the invention comprises a column bead 320 having ⅔ reduction in weight as the standard tire.
[0057] A second embodiment of an apparatus suitable for applying ply in a geodesic pattern onto a core is shown in FIG. 12 . The apparatus includes a ply applier head 200 which is rotatably mounted about a Y axis. The ply applier head 200 can rotate about the Y axis +/−100 degrees. The rotation of the ply applier head 200 is necessary to apply the cord in the shoulder and bead area. The ply applier head 200 can thus rotate about rotatable core 52 on each side in order to place the ply in the sidewall and bead area. The ply applier head 200 is mounted to a support frame assembly which can translate in the X, Y and Z axis. The ply applier head has an outlet 202 for applying one or more cords 2 . The cords may be in a strip form and comprise one or more rubber coated cords. Located adjacent the ply applier head 200 is a roller 210 which is pivotally mounted about an X axis so that the roller can freely swivel to follow the cord trajectory. The ply applier head and stitcher mechanism are precisely controlled by a computer controller to ensure accuracy on placement of the ply. The tire core is rotated as the cord is applied. The tire core is rotated discontinuously in order to time the motion of the head with the core. The ply applier head and stitcher apparatus is specially adapted to apply cord to the sidewalls of the tire core and down to and including the bead area.
[0058] The strip of rubber coated cords are applied to the core in a pattern following the mathematical equation ρ cos α=constant. FIG. 5 illustrates ply curves 1 , 2 , and 3 having geodesic ply paths. Curves 2 and 3 illustrate an angle β, which is the angle the ply makes with itself at any point. For the invention, the angle β is selected to be in the range strictly greater than 90 degrees to about 180 degrees. Preferably, the geodesic path (or orbital path) of the invention is ply curve 2 with β about equal to 180 degrees. For ply curve 2 , if a point on the curve is selected such as point A, the angle of ply approaching point A will be equal to about 180 degrees. Likewise, the angle of the ply going away from point A will also be about 180 degrees. Thus for any point on curve 2 , the angle of ply approaching the point and leaving the point will be about 180 degrees, preferably substantially 180 degrees.
[0059] As shown in FIG. 5 , the angle α 0 is selected so that the cord is tangent to the bead. Starting at a point A, the cord is tangent to the bead. Curve 1 of FIG. 5 illustrates the cord path from point A to the center crown point B, which is an inflection point. The cord continues to the other side of the tire wherein the cord is tangent at point C. The process is repeated until there is sufficient coverage of the core. Depending on the cord size and type selection, the cords are wound for 300 to 450 revolutions to form the carcass. Since the cords are tangent to the bead at multiple locations, the build up of the cords in the bead area form a bead.
[0060] As described above, the ply cords are applied to the core in a pattern following the mathematical equation ρ cos α=constant. Using a three dimensional grid of data points of the core, a calculation of all of the discrete cord data points satisfying the mathematical equation ρ cos α=constant may be determined. The three dimensional data set of the core is preferably X,Y,Ψ coordinates, as shown in FIG. 5 . A starting point for the calculation is then selected. The starting point is preferably point A of FIG. 5 , which is the point of tangency of the cord at the bead location. An ending point is then selected, and is preferably point C of FIG. 5 . Point C represents the point of tangency on the opposite side of the tire compared to point A. Next the change in Ψ is calculated from point A to point C. The desired cord path from the starting point A to ending point C is then determined from the three dimensional data set using a method to determine the minimum distance from point A to point C. Preferably, dynamic programming control methodology is used wherein the three dimensional minimum distance is calculated from point A to point C. A computer algorithm may be used which calculates each distance for all possible paths of the three dimensional data set from point A to point C, and then selects the path of minimal distance. The path of minimum distance from point A to point C represents the geodesic path. The discrete data points are stored into an array and used by the computer control system to define the cord path. The process is them repeated from point C to the next point of tangency and repeated until sufficient coverage of the carcass occurs.
Geodesic Ply With Indexing
[0061] In a variation of the invention, all of the above is the same except for the following. The strip is applied starting at a first location in a first continuous strip conforming exactly to ρ cos α=constant for N revolutions. N is an integer between 5 and 20, preferably 8 and 12, and more preferable about 9. After N revolutions, the starting point of the strip for the second continuous strip is moved to a second location which is located adjacent to the first location. The strip is not cut and remains continuous, although the strip could be cut and indexed to the starting location. The above steps are repeated until there is sufficient ply coverage, which is typically 300 or more revolutions. The inventors have found that this small adjustment helps the ply spacing to be more uniform.
Radius Variation
[0062] In yet another variation of the invention, all of the above is the same except for the following. In order to reduce the buildup at the bead area, the radius ρ is varied in the radial direction by +/− delta in the bead area of the tire on intervals of Q revolutions. Delta may range from about 2 mm to about 20 mm, more preferably from about 3 to about 10 mm, and most preferably about 4 to about 6 mm. The radius is preferably varied in a randomized fashion. Thus for example, if Q is 100, then for every 100 revolutions, the radius may be lengthened about 5 mm, and in the second 100 revolutions, the radius may be shortened about 5 mm.
[0063] Another way of varying the radius is at every Qth revolution, the radius is adjusted so that the point of tangency is incrementally shortened by gamma in the radial direction, wherein gamma varies from about 3 mm to about 10 mm. Q may range from about 80 to about 150, and more preferably from about 90 to about 120 revolutions. Thus for example, Q may be about 100 revolutions, and gamma may be about 5 mm. Thus for every 100 revolutions, the radius may be shortened by 5 mm in the radial direction. The variation of the radius may be preferably combined with the indexing as described above.
Axial Variation
[0064] In yet another variation, all of the above is the same as described in any of the above embodiments, except for the following. In order to account for the buildup at the bead area, the cord axial dimension is increased in the bead area. Thus there is a deviation in the geodesic equation at the bead area. In the vicinity of the bead area, wherein ρ is <some value, a new X value is calculated to account for the buildup of material in the bead area. A new X value is calculated based upon the cord thickness. The new X value may be determined using a quadratic equation. The ρ and α values remain unchanged.
Dwell Variation
[0065] In yet another variation, all of the above is the same as described in any of the above embodiments, except for the following. In order to reduce the buildup at the bead area, a dwell angle Ψ is utilized. Thus instead of there being one point of tangency at the bead, the angle Ψ is dwelled a small amount on the order of 5 about degrees or less while the other variables remain unchanged. The dwell variation is useful to fill in gaps of the cord in the bead area.
Cord Construction
[0066] The cord may comprise one or more rubber coated cords which may be polyester, nylon, rayon, steel, flexten or aramid.
Test Results
[0067] Test tires of size P225/R60-16 were built having a geoply construction with both aramid and polyester cord. The geoply test tires were built with indexing every 9th iteration and having the cord tangent to the bead at certain locations. The angle β was selected to be 180 degrees. The test tire built using polyester cord had 400 total revolutions of cord, and with the starting location of the cord at every 9th revolution being indexed an amount 0.0012 m. The aramid construction tire had about 350 revolutions and an indexing factor of 0.0015 m. Each test tire included typical tire components and a single column 6 wire bead. Test tires were also built having no bead. The test tires were compared with a production tire having a size P225R60-16 and sold under the brand name GOODYEAR EAGLE RSA. As shown in FIGS. 14 and 15 , the geoply tire for both aramid cord and polyester cord showed a significantly higher normalized spring rate for the longitudinal, lateral and vertical direction. For the longitudinal spring rate, the geoply tire (both aramid and polyester construction) had a 50% greater spring rate than the production tire. The aramid cords that were utilized in the tire construction trials had a modulus of elasticity range of 18,000-50,000 MPa and TPI (twist per inch) in the range 9×9-16×16. It is preferred to have a TPI closer to the lower end of the stated range. The cord construction of the aramid cord had a DTEX of 1100/2 & DENIER 1000/2. The polyester cords that were utilized in the tire construction had a modulus of elasticity of about 8000 MPa, TPI 8.5×8.5, DTEX, 1670/2 and DENIER 1500/2.
Rolling Resistance Test Data
[0068] As shown in FIG. 16 , the aramid geoply tire had a 12.3% improvement in rolling resistance as compared to the production control tire. As shown in FIG. 17 , the polyester geoply tire showed a 5.4% improvement in rolling resistance compared to the production control. The better results for the aramid tire are believed to be due to the fact that the aramid tire has the highest vertical spring rate. Due to lower deflection, the tire consumes less energy. The improvement in rolling resistance was surprising and unexpected.
[0069] FIG. 18 illustrates a cross-sectional view of a standard radial tire as compared to a tire having an orbital ply of the present invention. For the same outside diameter, the load carrying characteristics of the orbital ply construction allow for a smaller size tire. Thus in one example, the wheel may be larger as shown with a narrower tire width. The orbital ply tire would result in a lighter weight, more aerodynamic tire with lower rolling resistance.
[0070] Variations in the present invention are possible in light of the description of it provided herein. While certain representative embodiments and details have been shown for the purpose of illustrating the subject invention, it will be apparent to those skilled in this art that various changes and modifications can be made therein without departing from the scope of the subject invention. It is, therefore, to be understood that changes can be made in the particular embodiments described which will be within the full intended scope of the invention as defined by the following appended claims. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention relates to, and is entitled to the benefit of the earlier filing date and priority of, co-pending U.S. patent application Ser. No. 09/859,164, entitled Modified Electrochemical Hydrogen Storage Alloy Having Increased Capacity, Rate Capability and Catalytic Activity, filed Jun. 20, 2002 and to U.S. patent application Ser. No. 09/290,633, filed Apr. 12, 1999, now U.S. Pat. No. 6,270,719, the disclosures of which are herein incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention pertains to electrochemical hydrogen storage alloys.
BACKGROUND OF THE INVENTION
[0003] In rechargeable alkaline cells, weight and portability are important considerations. It is also advantageous for rechargeable alkaline cells to have long operating lives without the necessity of periodic maintenance. Rechargeable alkaline cells are used in numerous consumer devices such as portable computers, video cameras, and cellular phones. They are often configured into a sealed power pack that is designed as an integral part of a specific device. Rechargeable alkaline cells can also be configured as larger cells that can be used for example, in industrial, aerospace, and electric vehicle applications.
[0004] The materials proposed in the prior art for use as hydrogen storage negative electrode materials for secondary batteries are materials that have essentially simple crystalline structures. In simple crystalline materials, limited numbers of catalytic site are available resulting from accidently occurring, surface irregularities which interrupt the periodicity of the crystalline lattice. A few examples of such surface irregularities are dislocation sites crystal steps, surface impurities and foreign absorbates. For more than three decades, virtually every battery manufacturer in the world pursued such crystalline electrode materials for electrochemical applications, but none produced a commercially viable nickel metal hydride battery until after the publication of U.S. Pat. No. 4,623.597 (the '597 patent) to Ovshinsky, et al, which disclosed fundamentally new principles of electrode material design.
[0005] As taught in the '597 patent (the contents of which are incorporated by reference), a major shortcoming of basing negative electrode materials on simple ordered crystalline structures is that irregularities which result in the aforementioned catalytically active sites occur relatively infrequently. This results in a relatively low density of catalytic and/or storage sites and consequently poor stability. Of equal importance is that the type of catalytically active sites available are of an accidental nature, relatively few in number and are not designed into the material as are those of the present invention. Thus, the efficiency of the material in storing hydrogen and its subsequent release is substantially less than that which would be possible if a greater number and variety of sites were available.
[0006] Ovshinsky, et al, fundamental principles overcome the limitations of the prior art by improving the characteristics of the negative electrode through the use of disordered materials to greatly increase the reversible hydrogen storage characteristics required for efficient and economical battery applications. By applying the principles of disorder, it has become possible to obtain a high energy storage, efficiently reversible, and high electrically efficient battery in which the negative electrode material resists structural change and poisoning, with improved resistance to the alkaline environment, good self-discharge characteristics and long cycle life and deep discharge capabilities. The resulting disordered negative electrode materials are formed from lightweight, low cost elements by techniques that assure formation of primarily non-equilibrium metastable phases resulting in high energy and power densities at low cost. These non-equilibrium, metastable phases assure the formation of localized states where a special degree of disorder, if properly fabricated, can come from the structural and compositional disorder of the material.
[0007] The materials described generally in the '597 patent have a greatly increased density of catalytically active sites providing for the fast and stable storage and release of hydrogen. This significantly improved the electrochemical charging/discharging efficiencies and also showed an increase in hydrogen storage capacity. Generally, this was accomplished by the bulk storage of hydrogen atoms at bonding strengths within the range of reversible electromotive force suitable for use in secondary battery applications. More specifically, such negative electrode materials were fabricated by manipulating the local chemical order and hence the local structural order by the incorporation of selected modifier elements into the host matrix to create the desired disorder, type of local order and metal hydrogen bond strengths. The resulting multicomponent disordered material had a structure that was amorphous, microcrystalline, multiphase polycrystalline (but lacking long range compositional order), or a mixture of any combination of these structures.
[0008] The host matrix of the materials described in the '597 patent were formed from elements capable of storing hydrogen an thus are considered hydride formers. This host matrix was modified by incorporating selected modifier elements which could also be hydride formers. These modifiers enhanced the disorder of the final material, thus creating a much greater number and spectrum of catalytically active sites with an increase in the number of hydrogen storage sites. Multiorbital modifiers (such as transition elements) provided the greatly increased number of sites due to various bonding configurations available. Because of more efficient storage and release of hydrogen and because of the higher density of the catalytic sites, the hydrogen more readily found a storage site. Unfortunately, there remained, until U.S. Pat. No. 5,840,440 ('440), an insufficient density of new hydrogen storage sites formed due to disorder to significantly increase the hydrogen storage capacity of the material.
[0009] The '597 patent describes the use of, inter alia, rapid quench to form disordered materials having unusual electronic configurations, which results from varying the three-dimensional interactions of constituent atoms and their various orbitals. Thus, it was taught that the compositional, positional and translational relationships of the constituent atoms were not limited by crystalline symmetry in their freedom to interact. Selected elements could be utilized to further control the disorder of the material by their interaction with orbitals so as to create the desired local internal chemical environments. These various and at least partially unusual configurations generate a large number of catalytically active sites and hydrogen storage sites not only on the surface but throughout the bulk of the material. The internal topology generated by these various configurations allowed for selective diffusion of hydrogen atoms.
[0010] In general disorder in the modified material can be of an atomic nature in the form of compositional or configurational disorder provided throughout the bulk of the material or in numerous regions or phases of the material. Disorder can also be introduced into the host matrix by creating microscopic phases within the material which mimic the compositional or configurational disorder at the atomic level by virtue of the relationship of one phase to another. For example, disordered materials can be created by introducing microscopic regions or phases of a different kind or kinds of crystalline phases, or by introducing regions of an amorphous phase or phases, or by introducing regions of an amorphous phase or phases in addition to regions of a crystalline phase or phases. The types of disordered structures that provide local structural chemical environments for improved hydrogen storage characteristics include amorphous materials, microcrystalline materials, multicomponent multiphase polycrystalline materials lacking long range composition order or multiphase materials containing both amorphous and crystalline phases.
[0011] Short-range, or local, order is elaborated on in U.S. Pat. No. 4,520,039 to Ovshinsky, entitled Compositionally Varied Materials and Method for Synthesizing the Materials the contents of which are incorporated by reference. This patent discloses that disordered materials do not require periodic local order and how spatial and orientational placement of similar or dissimilar atoms or groups of atoms is possible with such increased precision and control of the local configurations that it is possible to produce qualitatively new phenomena. In addition, this patent discusses that the atoms used need not be restricted to “d band” or “f band” atoms, but can be any atom in which the controlled aspects of the interaction with the local environment and/or orbital overlap plays a significant role physically, electronically, or chemically so as to affect physical properties and hence the functions of the materials. The elements of these materials offer a variety of bonding possibilities due to the multidirectionality of f-orbitals, d-orbitals or lone pair electrons. The multidirectionality (“porcupine effect”) of d-orbitals provides for a tremendous increase in density of sites, the spectrum of types of sites and hence the presence of active storage sites. Following the teaching can result in a means of synthesizing new materials which are disordered in several different senses simultaneously.
[0012] The '597 patent is described in detail above because this patent represents a starting point for the investigation that resulted in the present invention. That patent introduced the concept of making negative electrode material for nickel metal hydride batteries from multicomponent disordered alloys. This teaching was diametrically opposed to the conventional “wisdom” of battery manufacturers at the time. It was not until this concept was adopted in production processes by said manufacturers that negative electrode materials with an increased number of catalytically active sites were produced and nickel metal hydride batteries became commercially viable. In capsule form, the '597 patent taught that significant additional sites for hydrogen catalysis (to allow the rapid storage and release of hydrogen and greatly improve stability) were formed and made available by purposely fabricating disordered negative electrode material (as opposed to the homogeneous, ordered polycrystalline material of the prior art). The '597 patent also proposed that the use of disorder could be employed to obtain additional hydrogen storage sites. However, it was not appreciated that in order to obtain a substantial increase in hydrogen storage capacity from such non-conventional storage sites, it would be necessary to increase the number of storage sites by approximately 3 orders of magnitude.
[0013] Not only was the teaching of the '597 patent adopted by all nickel metal hydride manufacturers, but in recent years some of these manufacturers have begun to use rapid solidification techniques (as taught by Ovshinsky) to increase the degree of disorder within a negative electrode alloy formula. For instance, battery companies have even gone so far as to rapidly quench highly-modified LaNi 5 -type electrochemical negative electrode material. By employing nonequilibrium processing techniques, the resulting negative electrode material includes hydrogen storage phases and catalytic phases on the order of 2000 Angstroms in average dimension. The hydrogen storage capacity of the negative electrode material does not improve significantly, but the catalytic activity is greatly improved as evidenced by improved rate capability and stability to oxidation and corrosion, resulting in increased cycle life.
[0014] As mentioned above, certain battery companies have begun to investigate the use of rapidly-quenched, highly modified LaNi 5 type hydrogen storage materials for electrochemical applications. For example, in Phys. Chem 96 (1992) No. 5 pp. 656-667, P. H. L. Notten, et al of Philips Research Laboratories presented a paper entitled “Melt-Spinning of AB 5 5 -Type Hydride Forming Compounds and the Influence of Annealing on Electrochemical and Crystallographic Properties.” In this paper, non-stoichiometric modified LaNi 5 5 materials, La 6 Nd 2 Ni 3 Co 24 Si 1 and La 6 Nd 2 Ni 26 Co 24 Mo 1 were rapidly solidified. These non-stoichiometric materials were compared to their stoichiometric counterparts with the result being that the non-stoichiometric materials demonstrated good, but not unusual hydrogen storage capacity. However, the non-stoichiometric compounds did show the presence of additional volume percents of a catalytic phase, which phase, as predicted by the '597 patent, was responsible for the improved electrochemical properties as compared to the properties found in the examples of stoichiometric material. Once again, and more importantly, no significantly higher density of non-conventional hydrogen storage sites were obtained. In research and development activities at Energy Conversion Devices, Inc. with highly modified TiNi-type electrochemical negative electrode materials, such as described in U.S. Pat. No. '440 which is incorporated herein by references, rapidly quenched electrode materials were melt spun. The work resulted in improved oxidation and corrosion resistance and cycle life was increased by a factor of five. On the other hand and as was true in the case of the aforementioned Japanese work, no significant increase in hydrogen storage capacity was demonstrated and the phases of the negative electrode material present were also relatively large.
[0015] Therefore, while the teachings of the '597 patent were revolutionary for those of ordinary skill in the art in learning to apply the principals of disorder disclosed therein to negative electrode materials to obtain commercial batteries with commercially viable discharge rates and cycle life stabilities while maintaining good hydrogen storage capacity, the '597 patent provided for the most part generalities to routineers concerning specific processes, processing techniques, alloy compositions, stoichiometries in those compositions, etc. regarding how to further significantly increase the hydrogen storage capacity (as opposed to the catalytic activity). It was not until the '440 patent that a teaching was presented of the nature and quantification of additional active storage sites required to significantly increase the hydrogen storage capacity of the negative electrode material through the deliberate introduction of defect sites and the presence of other concurrent non-conventional and/or conventional storage sites.
[0016] Despite the exceptional electrochemical performance now provided by current highly disordered nickel metal hydride systems (twice the hydrogen storage capacity of conventional NiCd systems) consumers are demanding increasingly greater run times, safety and power requirements from such rechargeable battery systems. No current battery system can meet these demands. Accordingly, there exists a need for a safe ultra high capacity, high charge retention, high power delivery, long cycle life, reasonably priced rechargeable battery system.
[0017] While U.S. Pat. No. 5,840,440 (“the '440patent”) represents innovative ideas with respect to useable storage sites in an electrochemical negative electrode material due to the use of high defect density and small crystallite size, the focus of the '440 patent is on the bulk properties of the hydrogen storage alloy. Significant discussion therein relates to increased surface sites; however, the additional sites so described relate to the interior surfaces, or grain boundaries, again within the alloy. The '440 patent does not address the interface between the metal hydride alloy and the electrolyte at the so-called oxide layer.
[0018] Of most relevance to the present invention is commonly assigned U.S. Pat. No. 5,536,591 (“the '591 patent”) in which the oxide (metal/electrolyte) interface is addressed in detail and where teachings on composition, size and distribution of catalytic sites within the oxide interface was first provided.
[0019] The '591 patent taught that hydrogen storage and other electrochemical characteristics of the electrode materials thereof could be controllably altered depending on the type and quantity of host matrix material and modifier elements selected for making the negative electrode materials. The negative electrode alloys of the '591 patent were resistant to degradation by poisoning due to the increased number of selectively designed storage and catalytically active sites which also contributed to long cycle life. Also, some of the sites designed into the material could bond with and resist poisoning without affecting the active hydrogen sites. The materials thus formed had a very low self discharge and hence good shelf life.
[0020] As discussed in U.S. Pat. No. 4.716,088 (“the '088 patent”), the contents of which are specifically incorporated by reference, it is known that the steady state surface composition of V—Ti—Zr—Ni alloys can be characterized as having porous, catalytic regions of enriched nickel. An aspect of the '591 patent was a significant increase in the frequency of occurrence of these nickel regions as well as a more pronounced localization of these regions. More specifically, the materials of the '591 patent had discrete nickel regions of 50-70 Angstroms in diameter distributed throughout the oxide interface and varying in proximity from 2-300 Angstroms or preferably 50-100 Angstroms, from region to region. This was illustrated in the FIG. 1 or the '591 patent, where the nickel regions 1 were shown as what appear as particles on the surface of the oxide interface 2 at 178,000 X. As a result of the increase in the frequency of occurrence of these nickel regions, the materials of the '591 patent exhibited significantly increased catalysis and conductivity.
[0021] The increased density of Ni regions in the materials of the '591 patent provided metal hydride powder particles having a highly catalytic surface. Prior to the '591 patent, Ni enrichment was attempted unsuccessfully using microencapsulation. The method of Ni encapsulation results in the expensive physical, chemical or electrochemical deposition of a layer of Ni at the metal-electrolyte interface. The deposition of an entire layer was expensive, excessive and resulted in no improvement of performance characteristics since this kind of encapsulated layer did not result in the production of the localized, finely distributed nickel regions of 50-70 Angstrom in a porous matrix.
[0022] The enriched Ni regions of the 591 patent could be produced via two general fabrication strategies. The first of these strategies was to specifically formulate an alloy having a surface region that is preferentially corroded during activation to produce the described enriched Ni regions. It was believed that Ni was in association with an element such as Al at specific surface regions and that this element corroded preferentially during activation, leaving the enriched Ni regions described in the '591 patent. “Activation” as used herein specifically refers to “etching” or other methods of removing excessive oxides, such as described in the '088 patent as applied to electrode alloy powder, the finished electrode, or at any point in between in order to improve the hydrogen transfer rate.
[0023] The second of these strategies was to mechanically alloy a secondary alloy to a hydride battery alloy, where the secondary alloy preferentially corroded to leave enriched nickel regions. An example of such a secondary alloy was given as NiAl. The most preferred alloys having enriched Ni regions were alloys having the following composition: (Base Alloy) a Co b Mn c Fe d Sn e ; where the Base Alloy comprised 0.1 to 60 atomic percent Ti, 0.1 to 40 atomic percent Zr, 0 to 60 atomic percent V, 0.1 to 57 atomic percent Ni, and 0 to 56 atomic percent Cr; b was 0 to 7.5 atomic percent; c was 13 to 17 atomic percent; d was 0 to 3.5 atomic percent; e was 0 to 1.5 atomic percent; and a+b+c+d+e=100 atomic percent.
[0024] The production of the Ni regions of the '591 patent was consistent with a relatively high rate of removal through precipitation of the oxides of titanium and zirconium from the surface and a much lower rate of nickel removal, providing a degree of porosity to the surface. The resultant surface had a higher concentration of nickel than would be expected from the bulk composition of the negative hydrogen storage electrode. Nickel in the metallic state is electrically conductive and catalytic, imparting these properties to the surface. As a result the surface of the negative hydrogen storage electrode was more catalytic and conductive than if the surface contained a higher concentration of insulating oxides. Many of the alloys of the '591 patent include Mn. The effects of the addition of Mn to these alloys was generally discussed in U.S. Pat. No. 5,096,667, the disclosure of which is incorporated herein by reference. The addition of Mn usually results in improved charging efficiency. This effect appears to result from the ability of Mn to improve the charging efficiency of alloys into which it is added by improving oxidation resistance and oxygen recombination. It has been observed that oxygen gas generated at the nickel hydroxide positive electrode recombined at the surface of the metal hydride electrode. Oxygen recombination is an especially aggressive oxidizer of its environment, even compared to the alkaline electrolyte.
[0025] It is possible that the modifier elements added to the Base Alloy of the '591 patent, particularly Mn and Fe, and most particularly Co, either alone, or in combination with Mn and/or Al for example, act to catalyze oxygen reduction, thereby avoiding or reducing the oxidation of the surrounding elements in the metal hydride alloy. It is believed that this function of the modified alloys reduces or even eliminates the formation and build up of detrimental surface oxide, thereby providing a thinner and more stable surface.
[0026] It is believed that several additional factors may explain the unexpected behavior of Mn and Fe in the Base Alloys of the present invention: (1) The combination of Mn and Fe may affect the bulk alloy by inhibiting the bulk diffusion rate of hydrogen within the metal through the formation of complex phase structures, either by effecting the grain boundaries or by affecting the equilibrium bond strength of hydrogen within the metal. In other words, the temperature dependence of the hydrogen bond strength may be increased thereby decreasing the available voltage and capacity available under low temperature discharge. (2) It is believed that the combination of Mn and Fe may result in a lower electrode surface area for metallurgical reasons by increasing the ductility of the alloy and thereby reducing the amount of surface area formation during the activation process. (3) It is believed that the combination of Mn and Fe to these alloys may inhibit low temperature discharge through the alteration of the oxide layer itself with respect to conductivity, porosity, thickness, and/or catalytic activity. The oxide layer is an important factor in the discharge reaction and promotes the reaction of hydrogen from the Base Alloy of the present invention and hydroxyl ion from the electrolyte. It is believed that this reaction is promoted by a thin, conductive, porous oxide having some catalytic activity.
[0027] The combination of Mn and Fe does not appear to be a problem under room temperature discharge, but has shown a surprising tendency to retard the low temperature reaction. The formation of a complex oxide could result in a subtle change in oxide structure such as pore size distribution or porosity. Since the discharge reaction produces water at the metal hydride surface and within the oxide itself, a small pore size may be causing a slow diffusion of K + and OH − ions from the bulk of the electrolyte to the oxide. Under room temperature discharge where polarization is almost entirely ohmic to low temperature discharge where activation and concentration polarization components dominate the physical structure of the oxides with Fe and Mn compared to Mn alone could be substantially different.
[0028] Still another possible explanation is that Mn and Fe have multivalent oxidation states. Some elements within the oxide may in fact change oxidation state during normal state of charge variance as a function of the rate of discharge and can be both temperature, fabrication, and compositionally dependant. It is possible these multiple oxidation states have different catalytic activity as well as different densities that together effect oxide porosity. A possible problem with a complex oxide containing both Mn and Fe could be that the Fe component retards the ability of the Mn to change oxidation state if present in large quantities.
[0029] Throughout the preceding discussion with respect to the oxide it should be noted that the oxide also contains other components of the Base Alloy, such as V, Ti, Zr, Ni, and/or Cr and other modifier elements. The discussion of a complex oxide of Mn and Fe is merely for the sake of brevity and one skilled in the art should not infer that the actual mechanism cannot also include a different or more complex explanation involving other such elements.
[0030] Deficiencies of the Prior Art
[0031] While prior art hydrogen storage alloys frequently incorporate various individual modifiers and combinations of modifiers to enhance performance characteristics, there is no clear teaching of the role of any individual modifier, the interaction of any modifier with other components of the alloy, or the effects of any modifier on specific operational parameters. Because highly modified LaNi 5 alloys were being analyzed from within the context of well ordered crystalline materials, the effect of these modifiers, in particular, was not clearly understood.
[0032] Prior art hydrogen storage alloys, when incorporated into batteries, have generally exhibited improved performance attributes, such as cycle life, rate of discharge, discharge voltage, polarization, self discharge, low temperature capacity, and low temperature voltage. However, prior art alloys have yielded batteries that exhibit a quantitative improvement in one or two performance characteristic at the expense of a quantitative reduction in other performance characteristics
[0033] Electrical formation is defined as charge/discharge cycling required to bring the batteries up to their ultimate performance. For prior art alloys, electrical formation is essential for maximum battery performance at both high and low discharge rates. For instance certain prior art VTiZrNiCrMn alloys could require as many as 32 cycles of charge and discharge at various rates to fully form the electric vehicle battery. It is believed that this electrical formation causes expansion and contraction of the negative electrode alloy material as it alternately stores and releases hydrogen. This expansion and contraction induces stress and forms in-situ cracks within the alloy material. The cracking increases the surface area, lattice defects and porosity of the alloy material. Heretofore, NiMH batteries have required this electrical formation treatment.
[0034] There is no “set-in-stone” method of electrical formation. The reason for this is that different active metal hydride materials which have been prepared by different methods under different conditions, and formed into electrodes by different methods will require different electrical formation processing. Hence, no detailed method of electrical formation suitable for all batteries can be described. However, generally electrical formation involves a relatively complex procedure of cycling the prepared battery through a number of charge/discharge cycles at varying rates of charge/discharge to varying depths of charge/discharge.
[0035] This electrical formation requirement puts an additional financial burden on commercial battery manufacturers. That is, it requires the manufacturers to purchase capital equipment in the form of battery chargers and also requires the cost of labor and utilities to run the equipment. These costs are significant and are passed on to the consumer. Therefore, there remains a need in the art for an electrochemical hydrogen storage alloy which requires little or no electrical formation.
[0036] The chemical/thermal activation of the electrochemical hydrogen storage alloys involves a relatively lengthy period of immersing the alloy material (in powder or electrode form) into a concentrated potassium hydroxide or sodium hydroxide solution, preferably at an elevated temperature. In situ treatment of the electrodes in the battery is limited to a temperature of about 60° C. because of the separators used therein. In powder form, the temperature limit is higher. The normal maximum concentration of potassium hydroxide is about 30% by weight KOH in water. The required residence time depends on temperature and concentration, but is typically a few days for the finished batteries. Information on chemical/thermal activation of electrochemical hydrogen storage alloys is provided in the 088 patent. This again is another added cost for the manufacturer. The costs of raw materials such as KOH or NaOH and water, the cost of disposing of spent chemicals, the energy costs to heat the alloy materials and the KOH solution, the labor and inventory costs, and the time costs all make it desirable to reduce or eliminate this activation process. Therefore, there is a need in the art to develop an electrochemical hydrogen storage alloy which requires little or no chemical/thermal activation.
[0037] Additionally, prior art alloys have all been designed for ultimate capacity, and have not been designed for the high rate requirements of HEV use and the like. Prior art VTiZrNiCrMn alloys have a specific capacity of 380-420 mAh/g in electrode form. Recently, there has been increased demand for rechargeable batteries having higher power and rate capabilities in addition to the high energy.
[0038] Finally, prior art alloys having high electrochemical storage capacity have lacked a very highly catalytic surface. Some prior art alloys had a catalytic surface, but it was limited. Higher catalytic activity allows for higher exchange currents and thereby higher rate capabilities. Also, the surface area of the alloy affects the exchange current. That is, the higher the surface area, the greater the exchange current. Therefore, there is a need in the art for electrochemical hydrogen storage alloys which have a greater surface catalytic activity as well as a greater surface area.
SUMMARY OF THE INVENTION
[0039] The above deficiencies are remedied by a modified Ti-V-Zr-Ni-Mn-Cr electrochemical hydrogen storage alloy which has at least one of the following characteristics: 1) an increased charge/discharge rate capability over that the base Ti-V-Zr-Ni-Mn-Cr electrochemical hydrogen storage alloy; 2) a formation cycling requirement which is significantly reduced over that of the base Ti-V-Zr-Ni-Mn-Cr electrochemical hydrogen storage alloy; or 3) an oxide surface layer having a higher electrochemical hydrogen storage catalytic activity than the base Ti-V-Zr-Ni-Mn-Cr electrochemical hydrogen storage alloy.
[0040] The modified Ti-V-Zr-Ni-Mn-Cr electrochemical hydrogen storage alloy comprises, in atomic percentage: (Base Alloy) a Co b Fe c Al d Sn e , where said Base Alloy comprises 0.1 to 60% Ti. 0.1 to 40% Zr, 0 to 60% V, 0.1 to 57% Ni, 5 to 22% Mn and 0 to 56% Cr; b is 0.1 to 10.0%; c is 0 to 3.5%; d is 0.1 to 10.0%; e is 0.1 to 3.0%; and a+b+c+d+e=100%.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1 depicts Electrochemical capacity of 16 alloys at discharge currents of 50 and 12 mA/g, without alkaline etching;
[0042] FIG. 2 plots the peak power in W/Kg versus cycle number for alloys 01 , 02 , 03 , 04 , 05 , 12 , and 13 ;
[0043] FIGS. 3 a - 3 c plot cell capacity, number of electrical formation cycles and peak power at 50% depth of discharge (at room temperature), respectively for alloys 01 and 12 ; and
[0044] FIG. 4 , plots the specific power (W/Kg) at 50 and 80% depth of discharge for alloys 01 and 12 ;
[0045] FIGS. 5 a and 5 b depict the effect of alkaline etching on alloy- 01 , specifically depicted are plots of capacity versus cycle number at 12 and 50 mA/g discharge, respectively;
[0046] FIGS. 6 a and 6 b depict the effect of alkaline etching on alloy- 012 , specifically depicted are plots of capacity versus cycle number at 12 and 50 mA/g discharge, respectively;
[0047] FIG. 7 plots AC impedance (Nyquist plots) at 85% state of charge (SOC) of thermal/chemical activated negative electrodes prepared from base alloy- 01 and from alloy- 12 of the instant invention;
[0048] FIG. 8 plots discharge curves at 2C rate for C-cells manufactured using negative electrodes fabricated from base alloy- 01 and from alloy- 12 of the instant invention, it should be noted that the higher power capability demonstrated by alloy- 12 in half cell measurements was also reflected in the performance of the C-cells;
[0049] FIG. 9 shows the half cell capacity as a function of discharge rate, again, the electrodes using alloy- 12 electrodes exhibited better rate capability; and
[0050] FIG. 10 plots the pressure-concentration isotherm (PCT) curve of alloy- 12 cooled in a cylindrical mold verses a flat slab shaped mold which has a higher overall cooling rate.
DETAILED DESCRIPTION OF THE INVENTION
[0051] The deficiencies of the prior art are overcome by the instant modified VTiZrNiCrMn electrochemical hydrogen storage alloy. In order to improve the catalytic activity of the prior art negative hydride alloys, the base alloy material was modified by the addition of one or more elements to increase the surface area of the heat-activated alloys and to enhance the catalytic nature of the surface of the materials. In addition to VTiZrNiCrMn, the alloys also contain Al, Co, and Sn. The alloy has an increased charge/discharge rate capability over that of the base VTiZrNiCrMn electrochemical hydrogen storage alloy. It also has an electrical formation cycling requirement which is reduced to one tenth that of the base VTiZrNiCrMn electrochemical hydrogen storage alloy. A chemical/thermal activation is required by the base VTiZrNiCrMn electrochemical hydrogen storage alloy. Finally the alloy has an oxide surface layer having a higher electrochemical hydrogen storage catalytic activity and higher surface area than the base VTiZrNiCrMn electrochemical hydrogen storage alloy. Each of these properties will be discussed in detail hereinbelow.
[0052] Catalytic Activity
[0053] The 591 patent, discussed hereinabove, represents the best prior art teaching of the desirable properties of the metal/electrolyte interface, or surface oxide of the metal hydride material providing specific teaching on the role of metallic nickel sites as catalytic sites. The 591 patent also describes the nickel sites as approximately 50-70 Angstroms in size, with a broad proximity range of 2-300 Angstroms. With respect to proximity, the STEM micrographs provided suggest approximately 100-200 Angstrom proximity as following the teaching of the '591 patent.
[0054] To distinguish the alloys of the present invention over those of the '591 patent, the inventors have discovered superior catalysis and high rate discharge performance can be achieved by one or more of the following:
[0055] 1) the catalytic metallic sites of the inventive alloys are formed from a nickel alloy such as NiMnCoTi rather than just Ni;
[0056] 2) the catalytic metallic sites of the inventive alloys are converted by elemental substitution to an FCC structure from the BCC structure of the prior art Ni sites;
[0057] 3) the catalytic metallic sites of the inventive alloys are much smaller in size (10-50, preferably 10-40, most preferably 10-30 Angstroms) than the Ni sites of the prior art alloys (50-70 Angstroms) and have a finer distribution (closer proximity);
[0058] 4) the catalytic metallic sites of the inventive alloys are surrounded by an oxide of a multivalent material (containing MnO x ) which is believed to possibly be catalytic as well, as opposed to the ZrTi oxide which surrounded the prior art Ni sites;
[0059] 5) the oxide could also be multiphase with very small (10-20 Angstrom) Ni particles finely distributed in a MnCoTi oxide matrix;
[0060] 6) the oxide may be a mix of fine and coarse grained oxides with finely dispersed catalytic metallic sites:
[0061] 7) alloy modification with aluminum may suppress nucleation of large (50-70 Angstrom) catalytic metallic sites (at 100 Angstrom proximity) into a more desirable “catalytic cloud” (10-20 Angstroms in size and 10-20 Angstroms proximity);
[0062] 8) NiMn oxide is the predominant microcrystalline phase in the oxide and the catalytic metallic sites may be coated with NiMn oxide.
[0063] The instant alloys, therefore, distinguish over the '591 alloys in that: 1) the catalytic metallic sites are still present but may be nickel alloy and are much smaller and more finely divided; 2) the old TiZr oxide support is replaced by a NiMnCoTi oxide which is more catalytic and more porous; and 3) aluminum metal doping provides a very fine grain catalytic metallic site environment.
EXAMPLE I
[0064] Sn, Co, Al, and Fe were considered as additives to a base AB 2 alloy. Sixteen different chemical formulas were designed according to the orthogonal array used in the Taguchi method to minimize the total number of alloys needed to complete the design matrix. Each element has four different levels; i.e., Sn (0.4, 0.6, 0.8, 1.0), Co (0, 0.5, 1.0, 1.5), Al (0, 0.4, 0.8, 1.2), Fe (0, 0.4, 0.8, 1.2), as shown in Table 1 (all numbers are in atomic percentages). Alloy- 01 is the base formula (control) with only 0.4% Sn originating from one of the source materials (zircalloy in replacement of zirconium) to reduce raw materials cost.
TABLE 1 Alloy Element Concentration (Atomic %) Capacity # Sn Co Al Fe V Ti Zr Ni Cr Mn (mAh/g) 01 0.4 0.0 0.0 0.0 5.0 9.0 26.6 38.0 5.0 16.0 390 02 0.4 0.5 0.4 0.4 5.0 9.0 26.6 38.0 4.5 15.2 382 03 0.4 1.0 0.8 0.8 5.0 9.0 26.6 38.0 4.0 14.4 375 04 0.4 1.5 1.2 1.2 5.0 9.0 26.6 38.0 3.5 13.6 375 05 0.6 0.0 0.4 0.8 5.0 9.0 26.4 38.0 5.0 14.8 379 06 0.6 0.5 0.0 1.2 5.0 9.0 26.4 38.0 4.5 14.8 387 07 0.6 1.0 1.2 0.0 5.0 9.0 26.4 38.0 4.0 14.8 376 08 0.6 1.5 0.8 0.4 5.0 9.0 26.4 38.0 3.5 14.8 389 09 0.8 0.0 0.8 1.2 5.0 9.0 26.2 38.0 5.0 14.0 401 10 0.8 0.5 1.2 0.8 5.0 9.0 26.2 38.0 4.5 14.0 374 11 0.8 1.0 0.0 0.4 5.0 9.0 26.2 38.0 4.0 15.6 370 12 0.8 1.5 0.4 0.0 5.0 9.0 26.2 38.0 3.5 15.6 385 13 1.0 0.0 1.2 0.4 5.0 9.0 26.0 38.0 5.0 14.4 369 14 1.0 0.5 0.8 0.0 5.0 9.0 26.0 38.0 4.5 15.2 369 15 1.0 1.0 0.4 1.2 5.0 9.0 26.0 38.0 4.0 14.4 335 16 1.0 1.5 0.0 0.8 5.0 9.0 26.0 38.0 3.5 15.2 339
[0065] All sixteen alloys were prepared by induction melting under an argon atmosphere with commercially available raw materials. The melt size ranged from 20 to 60 kg depending on the crucible size been used. After reaching 1600° C., the melt was held at that temperature for 20 minutes to homogenize it. Afterwards, the liquid was cooled down to 1300° C. and tilt-poured into a carbon steel mold. The ingots thus obtained were pulverized by a hydride/dehydride process without mechanical grinding as indicated in U.S. application Ser. No. 09/141,668, filed Aug. 27, 1998, entitled A METHOD FOR POWDER FORMATION OF A HYDROGEN STORAGE MATERIAL, herein incorporated by reference. Powder of 200 mesh or smaller was roll-milled onto a Ni-mesh substrate without other conducting metal powder or inorganic additives. The electrochemical capacity of each alloy was determined by constructing a flooded full cell using grafted PE/PP separators, partially pre-charged Ni(OH) 2 counter electrodes, and 30% KOH solution as the electrolyte The cells were charged at 50 mA/g for 13 hours and then discharge at 50 mA/g and a final pull current at 12 mA/g.
[0066] The discharge capacity for the third cycle at 50 and 12 mA/g for each alloy are plotted in FIG. 1 . This figure indicates that alloy- 12 shows the smallest differential between capacities at 50 and 12 mA/g, which indicates a good high-rate material.
[0067] Electrical Formation Cycling
[0068] Electrical formation or workup cycling of NiMH type batteries, as discussed herein above, has previously been a requirement for alkaline type batteries. This electrical formation was required to bring the battery to full capacity and especially full power. Without such formation, the batteries perform below maximum capability. Typical formation entails cycling the virgin battery many times at differing charge/discharge rates. For example, the base alloy, having a nominal composition (in atomic %) Ti 9.0%, Zr 27.0%, V 5.0%, Ni 38.0%, Cr 5.0%, and Mn 16.0%, required 32 charge/discharge cycles to achieve full power. Particularly in the area of electric vehicles, where power translates into acceleration of the vehicle, formation cycling is an expensive process with respect to equipment, processing time and inventory control. Any reduction in the number of cycles required to form the battery to it's full capability reduces the cost of manufacturing.
[0069] The instant alloy materials have been specifically designed to speed up formation. To that end the instant alloy materials have reduced the electrical formation requirement thereof to just three cycles in consumer, cylindrical cells and also EV batteries. This reduction in formation cycles is ten fold over the prior art base alloy. Therefore, production times and costs are reduced, and throughput is increased.
EXAMPLE II
[0070] C-size cylindrical batteries were constructed using the alloys fabricated from example I as negative electrode. These cells included paste Ni(OH) 2 as the positive electrodes and 30% KOH solution as electrolyte. The peak power of the battery was measured by the pulse discharge method and the results of a few key alloys are plotted in FIG. 2 as a function of cycle number. It is clear from the figure that alloys- 02 , - 03 , - 04 , - 05 , - 12 , and - 13 all have higher peak power than the control (alloy- 01 ). Especially alloy- 12 which reached it's full rate capability after only three electrical formation cycles. This is a dramatic improvement over alloy- 1 for which more than 15 cycles are needed.
EXAMPLE III
[0071] Both electrodes from alloy- 01 and alloy- 12 were made into identical prismatic cells for electrical vehicle application (90 Ah by design). Testing results for these cells are summarized in FIGS. 3 a, 3 b and 3 c. Both cells reached their designed capacity and power after 5 days of heat treatment at 60° C. and various number of mini-cycles for electrical formation. Cell employing alloy- 12 showed marginal advantages in both capacity and power. However, the most significant finding is that the number of mini-cycles needed to achieve the maximum power was dramatically reduced from 39 (alloy- 01 ) to 9 (alloy- 12 ), which offers a substantial cost reduction in capital equipment and electricity.
[0072] The electrical formation was further studied to take full advantage of alloy- 12 . Instead of the typical 37 hours of electrical formation for alloy- 01 , the whole formation process can be reduced to 12 hours by using alloy- 12 . The final capacity and specific power were not affected by this aggressive formation scheme, ash show in FIG. 4 .
[0073] Chemical/Thermal Activation
EXAMPLE IV
[0074] All sixteen alloys obtained from Example I were examined after various etching conditions. This alkaline etch was designed to simulate the heat formation process during battery fabrication. Electrodes were cut into proper size (2 by 5 inches) and etched in a 100° C. 30% KOH solution for 1, 3, and 4 hours. Etched electrodes together with unetched electrodes were used to construct flooded full cells using graft PE/PP separators, partially pre-charged Ni(OH) 2 counter electrodes, and 30% KOH solution electrolyte. The cells were charged at 50 mA/g for 13 hours and then discharge at 50 mA/g and a final pull at 12 mA/g. The capacities under various etching conditions are plotted as a function of cycle number in FIGS. 5 a and 5 b for the alloy- 01 and FIGS. 6 a and 6 b for alloy- 12 , respectively. It is found that alloy- 12 is easier to form (reaching full capacity and rate capability within fewer cycles) when compared to the alloy- 01 .
[0075] Catalytic Activity & Rate Capability
[0076] The instant alloy materials have far outdistanced Misch metal nickel based metal hydride alloys. The rate of catalytic surface activity of the instant alloys and rate of bulk diffusion of hydrogen are similar. Therefore, neither process inhibits the rate of charge/discharge, when compared to the other. In fact, because of the improvements in catalytic surface activity, the instant alloys have much improved discharge rate capability, i.e. as much as 300% greater rate capability. This, as will be discussed further herein below, appears to be caused by the enhanced oxide layer of the instant alloy materials.
[0077] Electrochemical studies were conducted to characterize the newly developed derivative alloys and compare their properties with alloy- 01 material. The study helped to better understand the nature of the changes occurring at the surface of alloy- 01 as a result of the compositional and structural modifications and the relation of these changes to the increased catalytic activity and rate capability of the material.
[0078] AC Impedance—Surface Kinetic and Diffusion Properties
[0079] FIG. 7 shows AC impedance plots (Nyquist plots) at 85% state of charge (SOC) of thermal/chemical activated negative electrodes prepared from the alloy- 01 and alloy- 12 . The main semicircle in the impedance plots of FIG. 7 is due to the charge transfer which occurs at the surface of the MH electrode. The hydrogen species formed at this step are adsorbed to the electrode's surface. The diameter of this circle represents the charge transfer resistance R ct of the hydride reaction. At frequencies lower than that of the charge transfer semicircle, the impedance is attributed to the absorption of the hydrogen below the surface of the metal. This step is followed by the bulk diffusion step in which the absorbed hydrogen species diffuse into the bulk of the metal hydride material. The absorption step gives rise to a small semicircle at the lower frequency range of the impedance plots and the bulk diffusion step gives rise to the straight, Warburg, behavior observed at lower frequency range of the impedance plots. Following the Warburg region, the impedance turns into a 90° capacitive line due the fact that the hydrogen diffusion occurs through a finite length.
[0080] The impedance behavior shown in FIG. 7 therefore support a three step mechanism as described in the following equations:
M+H 2 O+e⇄MH ad +OH − Charge Transfer (A)
MH ad ⇄ MhabS Absorption (B)
MH abS ⇄ MhabB Bulk Diffusion (C)
Where MH ad is the adsorbed hydrogen, MH abS is the absorbed hydrogen just below the surface and MH abB is the absorbed hydrogen in the bulk of the negative material. The charge transfer step (A) controls the impedance of the electrode at the high frequency range. At lower frequencies, the bulk diffusion process dominates the impedance.
[0082] Surface Kinetics
[0083] The surface kinetics of the hydride reaction is measured by the charge transfer resistance (R ct ) or the exchange current (l 0 ). l 0 is related to R ct by the equation:
l 0 =RT/nFR ct (1)
[0084] Table 2 shows the charge transfer resistances obtained from the impedance plots of Figure 7 and the exchange currents for alloy- 01 and alloy- 12 . As Table 2 shows the exchange current for the 2.7% Co, Al, Sn modified alloy- 12 is 2-3 times larger than that of alloy- 01 , indicating faster charge transfer kinetic by the same proportion.
TABLE 2 Alloy R ct (ohm · g) I 0 (mA/g) Alloy-01 0.4 65 Alloy-12 0.17 155
[0085] The magnitude of the exchange current (l 0 ) is generally determined by the catalytic activity of the electrode surface measured by the exchange current density (i 0 ) and by the specific surface area (A) of the electrode. In order to understand better how each of these parameters contribute to the increase in charge transfer kinetics observed in the derivative alloys, the values of i 0 and A for the different electrodes were also measured. The double layer capacitance (C d1 ) of the electrodes calculated from the ac impedance plots of FIG. 7 were used to determine the surface area A of the different electrodes. To calculate the surface area from C d1 , a specific capacitance of 20 uF/cm 2 (a common literature value) was assumed. The exchange current densities of the different electrodes were calculated using the relationship
i 0 =l/A× 100 (2)
[0086] where i 0 in equation 2 is in mA/cm 2 , l 0 is in mA/g and A is in m 2 /g. Table 3 shows the values of l 0 , C d1 , A and i 0 for alloy- 01 and alloy- 12 .
TABLE 3 10 2 × Alloy I 0 (mA/g) C d1 (Far/g) A(m 2 /g) i 0 (mA/cm 2 ) Alloy-01 65 0.16 0.8 0.8 Alloy-12 155 0.26 1.3 1.2
[0087] As Table 3 shows, both the surface area and the exchange current densities are higher in alloy- 12 electrodes as compared to alloy- 01 electrodes. Calculations from Table 3 show that for alloy- 12 about 50% of the increase in the exchange current (l 0 ) can be attributed to the higher surface area of these materials and about 50% of the increase can be attributed to the higher exchange current densities of these materials as compared to alloy- 01 . The higher surface area of the alloy- 12 electrodes with respect to alloy- 01 electrodes occurred during the heat activation of the electrodes since ac impedance measurements showed that the surface area of these electrodes in the virgin state were similar to each other. The heat activation process helps to increase the surface area of the electrodes. The results presented here show that the modifying elements added to alloy- 01 serve an important role in creating higher surface area due to their dissolution at the surface during the heat activation process. The higher exchange current densities of alloy- 12 as compared to the base alloy indicates the added elements not only contributed to the increase in surface area of the electrodes but also contribute to the enhancement in the catalytic nature of the materials by changing the surface composition.
[0088] Though not wishing to be bound by theory, it is possible the oxide surface area is substantially increased by a mechanism similar to that in which Co, Al, and Sn modification causes the nickel catalytic sites to be reduced from 50-70 Angstroms to 10 Angstroms. It is possible in the VTiZrNiCrMn prior art material, that two mechanisms control 50-70 Angstroms size sites. First, microcrystallite size within the bulk alloy may inherently influence resultant Ni sites after oxidation of the remaining elements. It is more likely, however, that the dissolution, erosion and corrosion of the resultant oxide is influenced by its chemical makeup. For example, in a prior art oxide matrix dominated by TiZr oxide, which is relatively insoluble, corrosion/erosion may occur in large chunks of 50-70 Angstrom size, while the Sn, Al, Co modified materials may be corroding on an atomic basis on the order of 10 Angstroms. Al and Sn may be particularly crucial in this regard in that they may be bonded to Ni within the surface oxide but dissolve in a “finer” or less “chunky” manner than VTiZr oxides.
[0089] Bulk Diffusion
[0090] From the ac impedance plots of FIG. 7 , the diffusion rate of hydrogen in the bulk material can also be determined. While the surface kinetics determine the power capability of the electrode and batteries which use them, the diffusion rate determines the rate capability. The diffusion rate of the hydrogen species is reflected in the impedance of the electrodes at the lower frequency range of the impedance plots of FIG. 7 . R d is related to the diffusion coefficient of the hydrogen species (D H ) and to the diffusion length (l) by equation 3:
R d =V M /ZFa ( dE/dy )( l/ 3 D ) (3)
where V M is the molar volume of the electrode material, Z is the charge per hydrogen atom absorbed, F is Faraday number, a is the geometric surface area of the electrode and (dE/dy) is the change of equilibrium potential of the electrode per unit change of hydrogen absorption. This parameter was obtained from measured data of equilibrium potential versus state of charge of the electrodes and was calculated to be approximately 0.06V at a state of charge between 85% to 50%. D and I are the diffusion coefficient and diffusion length respectively. Assuming a diffusion length equal to the electrode thickness, the hydrogen diffusion coefficient of the different alloy materials could be calculated. Table 4 shows the diffusion resistance obtained from the Nyquist plot of FIG. 7 and the diffusion coefficient calculated for alloy- 01 and alloy- 12 . The diffusion coefficient of alloy- 12 is larger, giving rise to a proportionally higher diffusion rate and better rate capability for alloy- 12 .
[0092] Though not wishing to be bound by theory, the mechanism through which the Sn, Co, Al modified alloys may have improved bulk hydrogen diffusion rates may be related to one or more of the following:
[0093] 1. refinement of microstructure towards smaller crystallite sizes, which in turn promotes grain boundaries and hydrogen transport;
[0094] 2. higher hydrogen equilibrium pressure; or
[0095] 3. finer dispersion of catalytic sites within the bulk (similar to surface oxide).
TABLE 4 Alloy R d (ohm) D(cm 2 /sec) Alloy-01 1.4 3.9 × 10 −8 Alloy-12 0.97 5.6 × 10 −8
[0096] Cell Performance
[0097] The performance of the different negative electrodes was also studied in cylindrical C-cells. FIG. 8 shows discharge curves at 2C rate of C-cells manufactured using negative electrodes fabricated from alloy- 01 and from alloy- 12 . As FIG. 8 shows, the cells using alloy- 12 exhibited higher operating voltages reflecting superior power capability. FIG. 9 shows the capacity of electrodes fabricated from alloys- 01 and - 12 . C-cells using the alloy- 12 electrodes exhibited better rate capability.
[0098] Analytical Study—The Oxide Surface
[0099] The oxide surface of the instant alloys is the same thickness as that of the prior art alloys, however, the instant inventors have noticed that the modification of the alloys has affected the oxide surface in several beneficial ways. First the oxide accessibility has been affected. That is, the additives to the alloy have increased the porosity and the surface area of the oxide. This is believed to be caused by Al, Sn and Co. The modifiers added to the alloy are readily soluable in the electrolyte, and believed to “dissolve” out of the surface of the alloy material, leaving a less dense, more porous surface into which the electrolyte and ions can easily diffuse.
[0100] Second, the inventors have noted that the derivative alloys have a higher surface area than the prior art alloys. It is believed that the mechanical properties of the alloy (i.e. hardness, ductility, etc.) has been affected. This allows the material to be crushed easier, and allows for more microcracks to be formed in the alloy material during production and also easier in-situ formation of microcracks during electrochemical formation.
[0101] Finally, the inventors have noted that the alloys are more catalytically active than the prior art alloys. This is believed to be cause by a more catalytic active oxide surface layer. This surface layer, as is the case with some prior art materials (see for example U.S. Pat. No. 5,536,591 to Fetcenko et al.,) includes nickel particles therein. These nickel particles are believed to provide the alloy with its surface catalytic activity. In the instant alloy, the inventors believe there are a number of factors causing the instant increase in catalytic surface activity. First, the inventors believe that the nickel particles are smaller and more evenly dispersed in the oxide surface of the instant alloy materials. The nickel particles are believed to be on the order of 10 to 50 Angstroms in size. Second, the inventors believe that the nickel particles may also include other elements such as cobalt, manganese and iron. These additional elements may enhance the catalytic activity of the nickel particles, possibly by increasing the roughness and surface area of the nickel catalytic sites themselves. Third, the inventors believe that the oxide layer itself is microcrystalline and has smaller crystallites than prior art oxide. This is believed to increase catalytic activity by providing grain boundaries within the oxide itself along which ions, such as hydrogen and hydroxyl ions, may move more freely to the nickel catalyst particles which are situated in the grain boundaries. Finally, the instant inventors have noted that the concentrations of cobalt, manganese and iron in the oxide surface are higher than in the bulk alloy and higher than expected in the oxide layer.
[0102] The surface area of the base alloy increased by about a factor of two during the activation treatment, the inventive alloy increases in surface area by about a factor of four. As discussed earlier, the higher surface area of the inventive alloy is only partially responsible for the higher catalytic property of these alloys. As the ac impedance measurements demonstrated, the better catalytic activity of the surface of the inventive alloy also contributes to the enhanced catalytic behavior thereof.
[0103] Hence, the improved power and rate capability of the inventive alloys is the result of the higher surface area within the surface oxide as well as improved catalytic activity within the oxide due to the smaller size and finer dispersion of the nickel catalyst particles compared to prior art materials. Observations from high resolution scanning transmission electron microscopy (STEM) included presence of nickel catalyst “clouds” having a size in the 10-30 Angstrom range and extremely close proximity, on the order of 10-20 and 10-50 Angstrom distance. Another contributing factor to the improved catalysis within the oxide is the transformation of the supporting oxide in which the Ni particles reside. In prior art materials, the supporting oxide may be primarily rare earth or TiZr based oxides while in the case of the inventive materials, the support oxide is now comprised of at least regions of NiCoMnTi “super catalysts.” This could also be NiMn regions surrounded by TiZr oxide. These super catalysts show a surprising lack of oxygen based on Electron Energy Loss Spectroscopy (EELS). It may be possible these regions are partially metallic or in a low oxidation state.
[0104] Another observation with the inventive materials is that prior art nickel catalytic regions within the oxide were bcc crystallographic orientation based on Select Area Electron Diffraction (SAED), which the inventive materials were observed to have an fcc orientation. It may be possible that the catalytic regions of Ni have been partially substituted by Co, Al, Mn, Sn, or other elements which have shifted the crystallographic orientation. It is indeed likely the bcc to fcc Ni shift reflects a higher degree of substitution.
[0105] Though not wishing to be bound by theory, it is also possible the fcc Ni in conjunction with NiCoMnTi regions and TiZr oxide may form a super lattice which may further promote ionic diffusion and reaction. Still another theory based on analytical evidence suggests that metallic Ni particles reside in a Mn oxide support. The presence of the Mn oxide is intriguing in that MnO x is multivalent and could promote catalysis via changing oxide states during the charge/discharge reactions.
[0106] Finally, another interpretation of the analytical evidence suggests even a multiphase surface oxide. In addition to metallic Ni or Ni alloys, there appears to exist both a fine grained and coarse grained support oxide. Perhaps the course grained aspect to the surface is dominated by TiZr prior art style oxide while the appearance of the fine grained support oxide in the inventive materials may be the MnOx or NiMnCoTi oxide or a MnCoTi oxide. The difficulty in assigning these structures more specifically resides in the very invention itself, i.e. the extremely small size and fine distribution. Even state of the art analytical instruments using electron probes, etc., have some kind of analytical region where averaging is taking place. Difficulty in assignment is mainly due to overlap of these extremely fine regions with one another during analysis.
[0107] In this context, one key role of Al,Sn,Co modification in these alloys may be as a “poison to the surface”, inhibiting the growth of large Ni particles. In other words, these specific dopants may be viewed as metallic catalysts and support oxide dispersants.
EXAMPLE V
[0108] Performance of negative electrodes produced with alloys of the instant invention can be further optimized by adjusting the melt-casting conditions of the alloys. For example, a flat slab mold was used to increase the quench rate during casting relative to the conventional cylindrical mold used in Example 1. The ingots obtained from the slab mold have an average thickness of less than about 5 inches and preferably less than about one inch as compared with 10 inch thick ingots obtained from the cylindrical mold.
[0109] The pressure-concentration isotherm (PCT) curves of alloy- 12 from both casting methods are plotted in FIG. 10 . From this figure, one can easily identify the superiority of faster solidification via the slab mold as compared with the slower cooling of the cylindrical mold by the extended curve into higher hydrogen storage. Electrodes were formed from alloy material from both ingots and subjected to half-cell testing as taught in Example 1. The results, which are listed in Table 5, confirm the PCT predictions about capacity. Not only did the full capacity increase from 355 mAh/g for the cylindrical mold to 395 mAh/g for the slab mold, but the capacity loss at high rate discharge was less for the slab mold. These increases in capacity can be directly related to higher power in the finished battery.
TABLE 5 Mold Type Capacity @ 50 mA/g Capacity @ 12 mA/g Cylindrical 329 mAh/g 355 mAh/g Slab 376 mAh/g 395 mAh/g | 4y
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FIELD OF THE INVENTION
The invention described herein relates to support grids for fuel rods in nuclear reactor fuel assemblies. More particularly, this invention relates to support grids having spring tabs and arches which are designed to provide increased contact area relative to the fuel rod.
BACKGROUND OF THE INVENTION
Commercial nuclear reactors used for generating electric power include a core composed of a plurality of fuel assemblies which generate heat used for electric power generation purposes. Each fuel assembly includes an array of fuel rods and control rod guide tubes held in spaced relationship with each other by grids of egg-crate configuration spaced along the fuel assembly length. The fuel rods may be approximately 0.5 inches in diameter and about 12 feet long, thus requiring a number of support grids along their length. Each grid includes a plurality of interwoven Inconel or Zircaloy straps which are vertically stacked to form multiple cells, with each cell having springs on two adjacent walls and projections, such as arches, on each of the other two adjacent opposing walls. The springs impose lateral forces on each fuel rod in the assembly, pressing the fuel rods into contact with the opposing arches. Although this fuel assembly design performs exceptionally well in a nuclear reactor, one disadvantage inherent in this design is that the inwardly projecting springs and arches cause fuel rod fretting wear at the contact points between the fuel rods and the support grid springs and arches.
Fuel rod fretting wear is an important design consideration for pressurized water reactor (PWR) steam generators. Fuel rod wear results from fluid-flow-induced fuel-rod vibration and from the existence of clearances, or gaps, between the fuel rods and the fuel rod supports. Such gaps are either initially present or form during reactor operation. If fuel rod vibration is excessive in duration and intensity, wear can result in unacceptable fuel rod wall material loss and fatigue cracking, leading to fuel rod failure.
SUMMARY OF THE INVENTION
In view of the foregoing, it is apparent that prior art support grid designs are susceptible to fuel rod failure due to fretting wear. One advantage of the support grids of the present invention is a reduction in the likelihood of fuel rod failure as compared to prior-art support-grid designs.
This and other advantages have been achieved by the construction of support grids having enhanced contact area with the fuel rods contained therein.
For example, according to an embodiment of the present invention, a support grid for use in a nuclear reactor fuel assembly is described which includes a plurality of intersecting straps that form openings for receiving, supporting and spacing a plurality of nuclear fuel rods. The support grid also includes a plurality of spring tabs biased into the openings, for applying lateral forces against the fuel rods, and a plurality of arches projecting into the openings, for providing lateral support for the fuel rods. Both the spring tabs and the arches have contours corresponding to a portion of the circumference of the fuel rods to provide substantially arc-shaped regions of contact between the fuel rods and the tab springs and arches.
Upon study of the specification and appended claims, further advantages of this invention will become apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic elevational view illustrating a fuel assembly according to an embodiment of the present invention.
FIG. 2 is a plan view of a portion of a support grid according to the prior art, illustrating the relationship of the fuel rods with respect to the springs and arches of the support grid.
FIG. 3 is a plan view of a portion of a support grid according to an embodiment of the present invention, illustrating the relationship of the fuel rods with respect to the spring tabs and arches of the support grid.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, there is shown in FIG. 1 a nuclear reactor fuel assembly 10 comprising an array of fuel rods 12 held in spaced relationship with each other by support grids 14a spaced along the fuel assembly length. Each grid includes a peripheral strap 20.
In assembling a fuel assembly, an array of control rod guide tubes 15 having control rods 40 adapted for slidable longitudinal movement therein, are positioned to extend axially through selected cells in the grid and are thereupon welded to grid tabs or strap walls to form the fuel assembly skeleton structure. Opposite ends of the guide tubes are attached to top and bottom nozzles 42, 44 in the usual manner.
Referring now to the portion of the prior-art support grid 14 shown in FIG. 2, upper and lower straps 22, 23 made of Zircaloy, Inconel or other material are interwoven to form grid sections of egg-crate configuration. The three support grids 14 shown in FIG. 1 are vertically aligned such that the square-shaped openings 24 formed by the interwoven straps 22, 23 are likewise vertically aligned to form cells that are of a size sufficient to receive fuel rods 12 or control rod guide tubes. Each square-shaped opening 24 designated to receive a fuel rod 12 has a pair of arches 25 on two adjacent sides and a pair of spring tabs 26 on the remaining opposing adjacent sides. The cells formed from the vertically-aligned square-shaped openings 24 within the support grids 14 thus contain adjacent, vertically aligned columns of arches 25 and spring tabs 26 which are disposed for contact with the fuel rods 12. Note that only lines of contact 27 are formed between the fuel rods 12 and the arches 25 and spring tabs 26.
FIG. 3 illustrates a portion of a support grid 14 which is designed in accordance with an embodiment of the present invention. As can be seen from FIG. 3, this improved support grid 14 is equipped with improved spring tabs 26a and arches 25a which follow the contour of the circumference of the fuel rod 12, thereby providing substantially arc-shaped areas of contact 27a between the fuel rod 12 and the arches 25a and spring tabs 26a. Obviously, contact area can be further increased by further increasing the length of the arc along which the arches 25a and spring tabs 26a follow the circumference of the fuel rod and by increasing the width (i.e., the dimension normal to the paper in FIG. 3) of the arches 25a and spring tabs 26a.
Previously published research indicates that metal wear (as measured by material volume removed) is proportional to load, with the area of metal contact essentially having no effect on the material volume removed. See. Archard, J. F., and Hirst, W., "The Wear of Metals Under Unlubricated conditions", Proc. Royal Society (London), Vol. 236A, pp. 397-410 (1956). Thus, by holding the contact force between the fuel rod 12 and the support grid 14 approximately constant and by increasing the contact area over which the material will be removed, the depth of any fuel rod fretting wear will be reduced since the wear is distributed over a larger area.
Moreover, when gaps arise between the fuel rod 12 and arches 25a and spring tabs 26a (e.g., due to interactions between the fuel rod 12 and support grid 14 under reactor operation conditions) the contoured shape of the support grid arches 25a and spring tabs 26a will dampen destructive vibrations between the fuel rod 12 and arches 25a and spring tabs 26a due to the enhancement of squeeze film effects between these elements. By dampening vibrations, impact loads are lessened and fuel rod 12 wear is reduced. Squeeze film behavior is characterized by a large buildup of force which occurs just prior to impact and which acts in a direction to reduce the impact. Research in this area, based on tube vibrations within an annular support, indicates that the increase in damping due to the squeeze film effect increases with the velocity of the vibration. Such damping should also increase with increasing the area of contact on impact, as suggested by the observation of a decrease in squeeze film effects upon tube canting (which causes point contact, rather than line contact) and by an increase in squeeze film effect with the length of contact area (i.e., support "thickness"). See, Haslinger, K. H., and Martin, M. L., "Experimental Characterization of Fluid and Squeeze Film Effects in Heat Exchanger Tube Supports", Journal of Fluids and Structures, Vol. 4, pp. 605-629 (1990).
Finally, the contoured shape of the arches 25a and spring tabs 26a provides additional resistive force during lateral loading (e.g., effects due to seismic activity, LOCA, operating, shipping, and so forth). This is due to the fact that, as the fuel rod 12 moves laterally, the spring tabs 26a deflect a greater distance due to their contoured shapes, producing larger relative forces.
Of course, in using contoured arches 25a and spring tabs 26a such as those shown in FIG. 3, assembly considerations such as potential mixing vane interferences should be taken into consideration. Fortunately, spacer grid assembly fixtures are available which have mixing vanes that can be held out of the way during assembly so that such interferences will not exist.
Thus, a support grid 14 for a nuclear reactor fuel assembly 10 has been described which includes contoured spring tabs 25a and arches 26a for increased contact area with nuclear fuel rods 12. Such increased contact area is provided to remove fuel rod fretting and to increase resistive forces during lateral loading.
From the foregoing description, one skilled in the art can easily ascertain the essential characteristics of this invention, and without departing from the spirit and scope thereof, can make various changes and modifications of the invention to adapt it to various usages and conditions. | 4y
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RELATED APPLICATION
The application relates to U.S. patent application Ser. No. 10/389,380, filed Mar. 13, 2003, entitled Alert Mechanism And Method For Monitoring Remote System Process Of Time Critical Data Via The Internet, which is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to the field of manufacturing of integrated circuits, and more specifically to manufacturing integrated circuits meeting special customer requirements with multiple subcontractors in remote locations.
BACKGROUND OF THE INVENTION
The manufacture of integrated circuit devices is a very complicated process. A manufacturer often needs the support of a number of subcontractors to successfully produce integrated circuit devices for its customers. FIG. 1 illustrates a common approach that many companies utilize in manufacturing integrated circuit devices. As shown in FIG. 1 , the process starts when an integrated circuit manufacturer 100 receives a production order from a customer 102 . Upon receiving the production order, it engages a number of subcontractors, such as semiconductor foundries 104 , assembly and packaging subcontractors 106 , testing subcontractors 108 and material suppliers 110 in manufacturing the integrated circuit devices to satisfy the customer's production order.
In the approach illustrated in FIG. 1 , the semiconductor foundries 104 normally produce multiple semiconductor wafers at one time. A ‘lot’ usually contains a number of wafers ranging from 1 to 25. Each wafer may contain thousands of copies of an integrated circuit design. Each copy of such integrated circuit design is called a ‘die’ or a chip. The wafers are sent to assembly and packaging subcontractors 106 where each die is cut from a wafer and put into a package. Next, each package is tested by testing subcontractors 108 before it is sent to the customer. The material suppliers 110 provide raw materials or components to each of the subcontractors and to the manufacturer 100 . All of the above tasks are performed in different subcontractor factories and these factories are sometimes located in different countries. It is the responsibility of the manufacturer to manage the simultaneous activities among all the subcontractors.
One of the challenges of the approach described in FIG. 1 is to allow customers to specify special manufacturing requirements of an integrated circuit design and to have the ability to track such customer special requirements throughout the manufacturing process. The ability to support customer special requirements permits a manufacturer to offer more services. For example, to achieve the best performance, many integrated circuit devices are designed to push the limits of the manufacturing process technology. Designers need to experiment with certain manufacturing process parameters in order to obtain the best results. Therefore, there is a need for a method and system that support customer special requirements and track such requirements throughout the manufacturing process while managing multiple subcontractors in remote locations effectively.
Another challenge of the approach described in FIG. 1 is that the activities occurring in all subcontractor factories need to be synchronized to ensure maximum utilization of production capacity. This problem is especially acute when ensuring that sufficient quantities of die are available to satisfy the special requirements of customers while at the same time minimizing unnecessary inventory buildup in the manufacturer's and subcontractors' warehouses.
SUMMARY OF THE INVENTION
Disclosed are a method and system for manufacturing integrated circuits meeting special customer requirements with multiple subcontractors in remote locations. The disclosed manufacturing automation execution system detects customer special requirements and keeps track of such special requirements throughout the manufacturing process. The system accesses various databases to retrieve relevant data for determining and issuing electronic die release orders to subcontractors in remote locations. The disclosed method and system enable a broader range of services in manufacturing of integrated circuits.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned features and advantages of the invention as well as additional features and advantages thereof will be more clearly understood hereinafter as a result of a detailed description of a preferred embodiment of the invention when taken in conjunction with the following drawings in which:
FIG. 1 illustrates the involvement among multiple companies in manufacturing semiconductor integrated circuit devices;
FIG. 2 illustrates a computer system running an integrated circuit manufacturing automation execution system;
FIG. 3 illustrates a preferred architecture of an integrated circuit manufacturing automation execution system;
FIG. 4 illustrates a method for managing and updating the die bank database;
FIG. 5 illustrates a method for managing and updating the assembly and test capability database;
FIG. 6 illustrates a method for monitoring subcontractor work in progress (WIP) status.
FIG. 7 illustrates a method for manufacturing integrated circuits meeting customer special requirements with multiple subcontractors in remote locations;
DETAILED DESCRIPTION
The following description is provided to enable a person skilled in the art to which the invention pertains to make and use the invention and sets forth the best modes presently contemplated by the inventors for carrying out the invention. Various modifications, however, will remain readily apparent to those skilled in the art. Any and all such modifications, equivalents and alternatives are intended to fall within the spirit and scope of the presently claimed invention.
Manufacturing Automation Execution System
In a preferred embodiment, a manufacturing automation execution (MAX) system is implemented using a computer system shown in FIG. 2 . The computer system comprises one or more processing units (CPU's) 200 , at least one network or other communications interface 203 , a memory device 204 , and one or more communication busses 206 for interconnecting these components. The MAX system may optionally have a user interface 202 .
The memory 204 may include high-speed random access memory and may also include non-volatile memory, such as one or more magnetic disk storage devices. The memory 204 may include mass storage that is remotely located from the central processing unit(s) 200 . The memory 204 preferably stores:
an operating system 208 that includes procedures for handling various basic system services and for performing hardware dependent tasks;
a communication module 210 that is used for controlling the communication between the system and various file servers 205 via the network interface(s) 203 and one or more communication networks, such as the Internet, other wide area networks, local area networks, metropolitan area networks, and so on;
a manufacturing automation execution module 212 , for implementing many of the main aspects of the present invention, including an electronic die release order module 214 , an assembly & test forecasting module 216 , a tester capacity and spare part inventory module 218 , a material planning & management module 220 , a rework management module 222 and a subcontractor work in progress (WIP) tracking module 224 ; and
Databases 226 , including die bank database 228 , assembly capability database 230 , die release database 232 , subcontractor WIP database 234 , and customer rule set database 236 .
The die bank database 228 stores the details of wafer lots available in the manufacturer's die bank. It includes information identifying the location, die type, age, wafer quantity, customer-special requirement tag, vendor lot number, lot comments, lot hold status, and wafer comments.
The assembly capability database 230 stores the qualification status of each subcontractor with respect to the assembly of a particular integrated circuit device. It includes information describing the bonding diagram, die type, package type, pin count, grade, test code, MSL code, customer process flow (CPF) code, pad size, pad pitch, subcontractor site status, latest revision number, active document deviations, and material status qualification codes for each site-device-package-bonding diagram combination.
The die release database 232 stores assembly and test instructions for lots released from the die bank database to subcontractors. It includes information about each fabricated lot, released lot, assembly site, test site, product, package, wafer identifications in lot, bonding diagram used, labels, date code, required ship date, and expedite handling information.
The subcontractor WIP database 234 stores information reflecting the manufacturer's WIP lot details updated daily by the subcontractor. It includes information such as subcontractor code, source/target device, vendor lot number, operation location, lot status, hold code and description, original ship-out date, current ship-out date, assembly quantity, test quantity, and current quantity.
The customer rule set database 236 stores various specialized customer requirements for certain integrated circuit devices. Information such as special test programs, special lot number indicator, special rule effective date, special bonding diagram to be used, and top marking specifications are kept in this database. In addition, this database stores manufacturing process parameters such as n-channel breakdown voltage 238 , n-channel saturation current 240 , p-channel saturation current 242 , n-channel threshold voltage 244 , p-channel threshold voltage 246 , yield before bake 248 , and yield after bake 250 .
The MAX module 212 and the databases 226 may include executable procedures, sub-modules, tables and other data structures.
In other embodiments, additional or different modules and data structures may be used, and some of the modules and/or data structures listed above may not be used. Additional or different information may be stored in the databases, and some of the information listed in the above databases may not be used.
Manufacturing Automation Execution System Architecture
FIG. 3 depicts an illustrative embodiment of a preferred architecture of the manufacturing automation execution (MAX) system 212 . As indicated in FIG. 2 , the MAX system 212 comprises an electronic die release order (EDRO) module 214 , an assembly & test forecasting module 216 , a tester capacity & spare part inventory module 218 , a material planning & management module 220 , a rework management module 222 and a subcontractor work in progress (WIP) tracking module 224 . These modules work collectively in data sharing and cross-functional controls.
Internally, the MAX system is supported by various computer systems within the manufacturer's computer network, such as a corporate planning system 308 , a shop floor management system 310 , a document control system 312 , a manufacturing parameters system 314 and a wafer test system 316 . The corporate planning system 308 determines assembly and test volume allocations to each subcontractor according to the subcontractor's respective qualifications and predetermined business criteria. The shop floor management system 310 tracks lot movements from die bank, assembly, testing to finished goods store. It facilitates the processing of wafer lots via a predefined series of routes. The document control system 312 maintains specifications of each subcontractor's manufacturing technologies, integrated circuit packages and testing capabilities. The manufacturing parameter system 314 maintains information such as assembly-qualified sites and their device process capabilities. The wafer test system performs testing of wafers to determine if the wafers pass customer requirements at the wafer sort process. Externally, the MAX system communicates with subcontractors' systems 302 and foundry systems 304 via the Internet 306 .
The following is a description of the modules within the manufacturing automation execution system 212 .
Electronic Die Release Order (EDRO) Module 214
The EDRO module 214 collects wafer records from foundries, and maps such records to the shop floor management system 310 on a daily basis. In addition, control parameters that are related to assembly qualified sites and their device process capabilities, bonding diagrams and other specification details are refreshed daily with data from the document control system 312 and manufacturing parameter system 314 . Local control tables are maintained and information is temporarily stored that is not readily available elsewhere in the manufacturer's database system.
Manufacturing personnel have the alternative of manually selecting wafers/lots themselves or programming the EDRO module to allocate the wafers/lots for them based on criteria entered via a web-based user interface which is driven by the Active Server Page of the Internet Information engine. Die release parameters are validated against a set of predefined logic rules, and an array of control parameter tables is used to check against potential errors and lot processing delays.
All EDRO transactions generated are transferred automatically into the shop floor management system 310 for update. The shop floor management system tracks lot movements from die bank, assembly, testing to finished goods store. It facilitates the processing of wafer lots via a predefined series of routes. This step is implemented by transferring data via text files with transaction codes to reflect lot split, merge, ship and process records, and their corresponding field sets. The records of any legacy shop floor management systems are uploaded and translated using software scripts to conform to the database file structures. This data file conversion automation eliminates a time consuming and redundant manual data entry step in the shop floor management system 310 .
At predefined delivery time windows, the EDRO records are saved into a file for each subcontractor and sent to the subcontractors via Internet FTP. The subcontractor receiver systems are preprogrammed to recognize the customized file format and parse the records and fields from the file accordingly. Linux scripts are used to provide intelligent system detection, recovery and alert mechanisms, ensuring that the data is completely and successfully delivered without the need for manual intervention. A link to the material planning and management module 220 permits the enforcement of soon-to-be obsolete piece-part material consumption priority, decrement of material quantity per expected consumption, and auto-alert on material shortages encountered at the EDRO transaction level. This die release transaction user interface is implemented using the Microsoft Open Database Connectivity (ODBC) interface.
Assembly & Test Forecasting Module 216
The assembly and test forecasting module 216 retrieves daily forecast numbers for assembly and test volumes from a file generated by the corporate planning system 308 and uploads the information into an assembly capability database 230 . The forecasted assembly and test volumes are allocated to the various subcontractors according to their respective qualifications and business criteria. Reports are generated and emailed to the subcontractors respectively.
The forecasted allocation data from the corporate planning system 308 is read by the tester capacity & spare part inventory module 218 and the materials planning & management module 220 via the Microsoft ODBC interface. The benefit of maintaining a single forecast data source is to preserve data integrity and consistency throughout the systems used in offshore planning. Any records generated can be readily accessible immediately by the other modules without any intermediate processing, thereby eliminating manual compilation work, redundant data transfer, duplications and storage overheads.
Tester Capacity & Spare Part Inventory Module 218
The tester capacity and spare part inventory module 218 produces a projected tester utilization report based on the test forecasts from the subcontractors 302 . The relevant data is readily accessible on demand from the subcontractors.
The tester records and their relevant spare-parts inventory are maintained in the assembly capability database 230 . Subcontractors provide periodic updates to the assembly capability database. The expected yield of the tester is computed based on a set of user-defined parameters and formulae for each tester type and configuration. The available reports provide visibility for the tester utilization at each subcontractor site, and they highlight any component shortages in advance. A capacity analysis tool is used for simulating different tester capacity utilization scenarios and suggesting reallocations where necessary.
Material Planning & Management Module 220
An online data bridge between the MAX system 212 and each subcontractor is established using the Internet 306 . Depending on system capabilities or preferences, subcontractors generate the files based on a predefined standardized field sequence using either fixed field length or comma delimiter formats. Microsoft Structured Query Language (SQL) Server Bulk Copy Program (BCP) scripts are customized for each subcontractor to facilitate data entry into databases. Data on the piece-part material current inventory levels and materials on order are updated on a weekly basis.
Using data received from the assembly & test forecasting module and the EDRO module, the material planning and management module 220 provides tools to facilitate proactive activities such as anticipating potential material shortages, avoidance of unnecessary holding costs, prevention of excess material purchases, and keeping material obsolescence to minimum possible levels. To enforce priority use of soon-to-be obsolete but usable piece-part materials, the material planning and management module 220 provides an interface to the EDRO module, which has a mechanism to prioritize the usage of soon-to-be obsolete materials first in the electronic die release order transactions.
As electronic die release orders are processed, the material planning and management module 220 reduces the material piece-part quantities accordingly as materials are consumed. This step provides realtime visibility of the current material inventory levels at each subcontractor site. The material planning and management module 220 automatically sends out emails to material supply management personnel notifying them if there are material shortages for fulfilling the electronic die release orders. This electronic alerting mechanism allows prompt action in expediting delivery of materials on order.
Rework Management Module 222
The rework management module 222 is linked to the EDRO module 214 , sharing the same die release database 232 with the EDRO module. As rework orders are conducted, the original lot attributes such as date codes are extracted from the die release database. The rework management module helps to cut down data entry activities, and ensures data accuracy.
On demand, the rework management module 222 generates a rework request file in Microsoft Excel format and sends the file to the subcontractor where the rework is performed. The status of the rework lots is then extracted from the returned rework file and updated into the die release database 232 via a custom Microsoft Excel Visual Basic for Applications (VBA) program using the Microsoft ODBC interface.
Subcontractor WIP Tracking Module 224
The subcontractor WIP tracking module 224 generates subcontractor WIP data and report files at least once daily. These files are extracted over the Internet via FTP from a subcontractor WIP database. Each subcontractor WIP system may use a subcontractor unique report format. In order to avoid burdening scarce subcontractor information system resources in developing a standardized format, the subcontractor WIP tracking module uses existing reports. This is achieved by developing Linux scripts with powerful text processing tools to read different report formats and process the report data into a format which is optimized for direct database upload using the built-in Microsoft SQL BCP utilities.
The subcontractor WIP tracking module 224 also creates a WIP summary report for data received from each subcontractor. This WIP summary report which is stored in the subcontractor WIP database 234 contains each subcontractor's WIP tables, with irrelevant data filtered. The WIP summary report is used to derive various reports on demand, each displaying WIP information from different user perspectives. The lot information is linked back to the EDRO transaction details via hyperlinked Active Server Pages program scripts of the Microsoft SQL servers.
The module maintains a process map for correlating manufacturer's process names with that of the subcontractors'. This is used to standardize and clarify the process descriptions in the WIP reports among all subcontractors. The module further determines any assembly lot that fails to start on time per EDRO instructions by matching the expected lot number in the WIP report.
Managing Customer Special Requirements
Managing & Updating Die Bank Database
FIG. 4 illustrates a method for managing and updating the die bank database 228 . The method starts in block 400 and moves to step 402 where the MAX system retrieves wafer data from a foundry system 304 . Wafer data is stored in a standardized text file format known as a Wafer Probe Record (WPR). The WPR contains wafer composition details such as wafer number, good die quantity and die type. One WPR file is created for each lot. In a predetermined time interval, the foundry system saves WPR in a foundry data file server. At a designated time interval, the MAX system accesses the foundry server and retrieves the WPR file over the Internet using FTP protocols. The WPR file from each foundry is then parsed to obtain wafer records, and such wafer records is then stored in the die bank database 228 .
In step 404 , the MAX system retrieves die bank inventory data from the shop floor management system 310 . In step 406 , the MAX system compares wafer details retrieved from foundries to the die bank inventory data stored in the shop floor management system. Only matched lots are made available for the next step of identifying customer-qualified wafers.
In step 408 , the system retrieves a list of customer qualified wafer records from the wafer test system 316 in accordance with the customer special requirements stored in the customer rule sets database 236 . In step 410 , the wafer records are scanned and tagged to denote that they are special customer-qualified wafers. In step 412 , the system updates the die bank database 228 with wafer records that are tagged as special customer-qualified wafers. The method ends in block 414 .
Managing & Updating Assembly Capability Database
FIG. 5 illustrates a method for managing and updating assembly capability database 230 . The method starts in block 500 and moves to block 502 where the MAX system retrieves assembly capability data. Control data such as qualified subcontractors and their device process capabilities, die type, package type and bonding diagrams are retrieved from the corporate planning system 308 .
In step 504 , the system further retrieves manufacturing document data where the latest document revision numbers for bonding diagrams are extracted from the document control system 312 . In step 506 , the MAX system updates the assembly capability database 230 with the information retrieved in steps 502 and 504 . The method ends in step 508 .
Monitoring Subcontractor Work In Progress Status
Once an EDRO of a lot is issued, the lot is released for assembly from the die bank database within a predefined period of time. If the released lot appears in the daily subcontractor WIP report, it indicates that the lot has started in production. Manufacturing personnel can determine that certain lots are behind schedule if they have not shown up in the WIP report after the expected lead-time from the receipt of the EDRO transaction. Manufacturing personnel can then follow up with the subcontractors on the lots that are behind schedule to expedite their release into assembly. In the event that the delay is inevitable, they can opt to reschedule lots in the finished goods inventory (FGI) to service the more urgent production lots.
FIG. 6 illustrates a method for monitoring subcontractor work-in-progress status. The method starts in block 600 . In step 602 , the system retrieves subcontractor WIP data from each subcontractor system 302 via the Internet. The WIP data is preprocessed into a format optimized for uploading into the MAX system. Next, in step 604 , the method updates the subcontractor WIP database 234 . Upon updating the subcontractor WIP database, the system scans the WIP database EDRO released lots in step 606 .
In step 608 , a determination is made whether there is any previously released EDRO lot that the production process has not yet started. If there is, the method moves to step 610 where the system sends an email to responsible personnel to follow up with subcontractor on the lot status. From the WIP report, manufacturer personnel can contact the subcontractors to find out the cause of the delay and expedite if possible. In the alternative, if the production process for all the EDRO released lots has been started, the method ends in step 612 .
Managing Customer Special Requirements
FIG. 7 illustrates a method for manufacturing integrated circuits meeting customer special requirements using multiple subcontractors in remote locations. The method starts in step 700 and thereafter moves to step 702 where the MAX system receives a customer transaction file via the Internet. In step 704 , the MAX system parses the customer transaction file to extract customer special requirements. For example, a certain customer has specific requirements that wafers used must pass a predetermined set of electrical criteria, such as the n-channel breakdown voltage 238 and the n-channel saturation current 240 , in order for them to be used in manufacturing integrated circuit devices. As a result, the manufacturer needs to perform wafer tests and generate a list of qualified wafers in the die bank database 228 . Thereafter, when an EDRO transaction is generated for the specific device, the MAX system can ensure that only customer-qualified wafers are utilized or else it will stop the transaction from proceeding.
In step 706 , the system updates customer rule sets database 236 with information extracted in step 704 . Whenever new requirements or changes in customer special requirements are provided, such information is updated in the customer rule set database 236 .
In step 708 , the MAX system automatically selects wafers within a lot to be used based on a first-in-first-out (FIFO) shelf life mechanism. It picks wafers by die type from a foundry lot in the die bank database 228 . Quite often, not all wafers in a lot are required to full fill a customer's order and hence not all wafers are selected from the lot. This procedure of separating a group of wafers in a lot is called ‘lot splitting’. In this case, the original lot is called a ‘parent lot’, and the new lot that contains the selected wafers is called a child lot. The system issues a new lot number for the child lot and the parent lot remains in the die bank database 228 .
In step 710 , a determination is made as to whether there are any customer special release parameters by examining the first character of a lot number, which is marked to indicate a customer-qualified wafer lot. If there is no customer special parameters, the method continues at step 714 .
In the alternative, the method goes to step 712 where the system validates any special release details by checking wafers selected in step 708 . If one or more wafers are found not to be customer-qualified, the system prompts an error message and repeats the process of wafer selection. Certain special release details, such as EDRO assembly site, wafer number, lot number, marking instructions, due date, and bonding diagram are entered in the system. This step is important because if there were engineering issues during the manufacturing process, having special release details of the affected lots can greatly help troubleshooting the problematic die. In addition, the parent lot and its child lots can be identified and recalled from the production floor, avoiding unnecessary scrappage and therefore reducing adverse impact on production costs.
In step 714 , subsequent to selecting wafers and entering special release details, the system validates such release parameters by checking the special release details entered in step 712 versus the parameters stored in assembly capability database 230 . It prompts for correction if any error is found. The newly entered special release details are used to derive other essential data to complete the EDRO transaction.
In step 716 , the system displays final details of the EDRO transaction and requests the manufacturing personnel to confirm the electronic die release order. In step 718 , the system updates the die release database 232 with the new EDRO records. At this point, the new EDRO records in the die release database 232 are ready for electronic transmission to subcontractors 302 over the Internet 306 .
In step 720 , the system generates the die release file for transmission to subcontractors 302 . At a predetermined time window, the system scans the die release database 232 for any new EDRO records. The new EDRO records for each subcontractor are separated and written into text files in a standardized field sequence.
In step 722 , the system transfers die release file to each subcontractor. The system first establishes a file transfer protocol (FTP) connection and then sends each file to the corresponding subcontractor's file server. After a file transfer, a listing of the directory storing the transferred file is fetched from the subcontractor's file server and the file size reported therein is checked against the original file transferred. If the sizes of the transferred file and the received file do not match, the file transfer process is repeated. This file transfer checking and retrying process will be repeated until the sizes of the transferred file and the received file match or until a predetermined maximum number of tries are made. If the file transfer is still unsuccessful after the maximum number of tries are made, which may occur if the subcontractor's computer system is down, the data is accumulated for the next FTP transmission window. In an alternative embodiment of the disclosure, if the file transfer error persists, the system sends an email to alert responsible personnel of the error condition. The method ends in step 724 .
The MAX system provides at least four important advantages for manufacturing of integrated circuits with multiple subcontractors in remote locations. First, it supports customer special requirements. The system performs tracking of customer special requirements with minimal impact to the existing manufacturing process. Second, it simplifies the process of placing electronic die release orders to subcontractors. As a result, there is significant reduction in manual activities and process time required for both the manufacturer and the subcontractors. Third, the system eliminates the need to use multiple standalone computer systems by replacing the process with a convenient and user-friendly one-stop center for customer transactions. Fourth, it improves the accuracy of electronic die release orders through automatic validation of input data from subcontractors and automatic derivation of information using various application programs and scripts. This system reduces delay in fulfilling customer orders and reduces the possibility of building wrong products.
One skilled in the relevant art will easily recognize that various modifications of this disclosure can work well for the inventive manufacturing automation execution system while preserving the spirit of the present invention. For example, different modules of the system can be executed by one or more servers on the manufacturer's computer network, and various databases can reside in one or more file servers either located locally or in remote locations.
The foregoing description, for purposes of explanation, has been described with reference to specific embodiments. However, the illustrative discussions above are not intended to be exhaustive or to limit the invention to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. | 4y
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This application is a divisional application of application Ser. No. 09/845,448, now U.S. Pat. No. 6,686,664, filed Apr. 30, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to methods and structures for attaching a semiconductor chip or chip carrier to a substrate and, more particularly, to methods and structures for attaching a semiconductor chip or chip carrier to a substrate using solder ball technology.
2. Background and Related Art
In the fabrication of electronic devices as, for example, during ball attach or card attach, low melt C4 (controlled collapsed chip connection) solder balls on a chip carrier will reach their melting temperature and become liquid. Typically, for solder with a high tin content, the volume expansion associated with this phase change can range between 3 and 6%. If the C4 solder balls have been encapsulated prior to this volume change, as is typically the case, the volume expansion is constrained and the resulting pressure may result in the squeezing of this expanding volume of liquid into voids present in the surrounding underfill and its associated interfaces. This volume expansion of solder may also result in opening any weak interfaces, like underfill to chip passivation (for example polyimide) or underfill to solder mask interfaces. It is clear that the effect of such action could result in device failure.
SUMMARY OF THE INVENTION
In accordance with the present invention, structures are provided on the chip carrier to relieve pressure created by volume expanding solder upon heating and reflow. The structures are formed directly beneath the solder balls or bumps. The pressure relief structure may be in the form of microchannels or vias, an air cushioned diaphragm, or porous or compressible medium, like foam. The various structures act in a manner to accept or accommodate the expanding or excess volume of solder created during melting to thereby minimize or avoid the creation of pressure that may affect the region adjoining or surrounding the solder balls and the various material interfaces.
Accordingly, it is an object of the present invention to provide improved methods of making connections in electronic devices, to enhance overall reliability of the product.
It is another object of the present invention to provide structures which act to accommodate expanding solder when it changed to the liquid phase.
It is yet another object of the present invention to provide a method of attaching enclosed solder balls to connection pads by providing structures that accommodate expanding solder upon reflow.
It is a further object of the present invention to provide structures that relieve internal pressures in an enclosed electronic packaging environment caused by the expansion of solder when going from the solid to liquid phase.
It is yet a further object of the present invention to provide methods and structures that relieve pressure from solder reflow to thereby prevent damage to material interfaces in electronic devices.
These foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of a preferred embodiment of the invention, as illustrated in the accompanying drawings, wherein like reference members represent like parts of the invention.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 shows a cross-section of a typical Prior Art arrangement wherein a semiconductor chip is positioned for electrical connection to a substrate through an array of solder balls.
FIG. 2A shows an enlarged section of the arrangement shown in FIG. 1 with one form of structure used to release pressure on reflow of solder balls.
FIG. 2B shows an enlarged section of the arrangement shown in FIG. 1 with a further structure used to release pressure on reflow of solder balls.
FIG. 3 shows another enlarged section of the arrangement shown in FIG. 1 with an air-cushioned form of structure used to relieve pressure on reflow of solder balls.
FIG. 4 shows yet another enlarged section of the arrangement shown in FIG. 1 with another air-cushioned form of structure used to relieve pressure on reflow of solder balls.
FIG. 5 shows still yet another enlarged section of the arrangement shown in FIG. 1 with a compressible form of structure used to relieve pressure on reflow of solder balls.
FIG. 6 shows a further enlarged section of the arrangement shown in FIG. 1 with a further porous form of structure used to relieve pressure on reflow of solder balls.
DETAILED DESCRIPTION
With reference to FIG. 1 , there is shown a conventional arrangement of semiconductor chip and substrate. Substrate 3 may be a PCB type of substrate or a ceramic substrate, for example. Substrate 3 may also be a single chip module or a multi chip module (MCM) which is, in turn, attached to a substrate, such as a PCB. Chip 1 is shown positioned on substrate 3 with C4 solder balls or bumps 5 , for example, positioned therebetween. Solder balls 5 may, in fact, not be ball shape but may be shaped like bumps or be, very generally, globular in shape. FIG. 1 shows the balls 5 somewhat elongated in shape but slightly truncated at their ends by conductive pads 7 and 9 . Thus, the terms “solder balls” or “solder bumps” should not be taken to be limiting in shape but taken to be more as a mass of solder. In this regard, it is clear that connection is not necessarily limited to a C4-type or a flip chip solder connection but may, for example, be a BGA solder interconnect. Typically, solder balls 5 are first attached to conductive pads 7 on substrate 3 . Pads 7 may, for example, be copper pads. Chip 1 is then aligned so that its copper pads 9 , or other bump limiting metallurgy (BLM) structures, align with solder balls 5 .
As further shown in FIG. 1 , a layer of insulating material 11 surrounds and encapsulates solder balls 5 . Typically, the chip and substrate pads are aligned to solder balls 5 and then the arrangement heated to reflow the solder to make the connection. After connection is made, an underfill is then dispensed between chip and substrate to provide encapsulation of the solder connections and support therefor.
Whatever technique is used to make connections and encapsulate same, it is clear that when encapsulated there is little room for expansion of the solder balls or connections on subsequent single or multiple reflow. Subsequent reflow may occur, for example, when there is subsequent attachment to a PCB, where substrate 3 is a single or MCM, or subsequent attachment to a card. It can also occur during preconditioning. This problem is particularly severe for low melt single alloy solders. Typically, the volume expansion associated with high tin content solders in going to the liquid phase is 3 to 6%. However, the problem may exist for any of a variety of solder alloys that exhibit high volume expansion (e.g. >3%) on melting and that will encounter additional reflow (melt) temperatures during assembly or preconditioning of the package.
With such volume expansion in an encapsulated environment, the phase change instantaneously produces pressure that may result in the squeezing of the excess volume into voids present in the surrounding underfill or spacer, or produce a hydraulic force acting on the semiconductor chip thus opening or delaminating any weak interfaces, such as, the underfill-polyimide and underfill-solder mask interfaces. In addition, solder bridging, solder migration to interfaces and solder depletion within joints may occur. In this regard, it should be understood that the problems caused by solder volume expansion on reflow also exist with second and subsequent levels of solder interconnects, such as, BGA solder joints that have been underfilled or encapsulated. Accordingly, the teachings of the present invention to solve such problems are equally applicable to second and subsequent levels of packaging. The teachings help in mitigating the above related problems and provides for improving reliability of the electronic product.
In accordance with the present invention, several structural arrangements are provided to relieve pressure created by volume expansion of solder during reflow. FIG. 2A is enlarged partial section showing one of the solder balls of FIG. 1 with such partial section showing one such structural arrangement for relieving pressure during reflow. Microchannel, cavity or via 13 is shown beneath solder ball 5 to accommodate expanding solder volume during reflow. Connection to other circuitry here is through top surface metallurgy connected to pad 7 . In this regard, each of the solder balls in the solder ball array is provided its own independent microchannel or via to facilitate expansion. These microchannels or vias may be, for example, laser drilled by laser ablation through pads 7 (forming hole 8 ) and into the substrate 3 prior to mounting solder balls and chip to the substrate.
Representative dimensions for a 5% volume expansion of C4 solder balls might be A=140 μm, B=100 μm, C=45 μm and D=25 μm. Such dimensions would typically approximate the maximum volume of the microchannel that is needed to accommodate 5% volume expansion of solder. It should be understood, however, that, in general, the microchannel volume need not necessarily be large enough to accommodate the total volume expansion of the solder but rather the microchannel volume may be optimized to be large enough to sufficiently relieve pressure and limit stress build-up so that it is below the interfacial adhesion strength of the underfill. This, in turn, will depend on the type of underfill and passivation on the die and the choice of solder mask material on the laminate.
Microchannel or via 13 , in FIG. 2A , has a non-wettable surface 15 such that during reflow, the excess volume of solder would be forced into microchannel 13 thus relieving the pressure by accommodating the excess volume without affecting the adjoining regions. Then, during cooling the surface tension of the solder would force the solder back up onto copper pad 7 thus regaining its original ball-like shape. It should be understood that the Figures are not to scale and are only generally illustrative of the shapes and sizes and are merely used to facilitate a description and understanding of the invention.
FIG. 2B shows a pressure relief structure similar that shown in FIG. 2A but rather than employ a single microchannel or via, multiple microchannels are employed under each solder ball, such as shown at 14 and 16 . As in FIG. 2A , holes in pad 7 may be laser ablated and then the microchannels or vias 14 and 16 either ablated or etched into substrate 3 . Similar to FIG. 2A , the surfaces of microchannels or vias 14 and 16 may be non-wettable.
Employment of multiple microchannels or vias, as shown in FIG. 2B , would be particularly useful for BGA solder joints, such as, those employed in MCM-L (multi chip module-laminate) and CSP (chip size package) applications that have large contact surface areas. By using multiple microchannels, the microchannel depths may be reduced to achieve the same total volume. Shorter microchannel depths have the advantage of shorter return paths for solder upon solidification. A particularly advantageous shape for the microchannels would be conical, as shown in FIG. 2B , with E>D for each hole. Although two microchannels or vias 14 and 16 are shown in FIG. 2B , it is clear that more than two holes could be employed. Typically, anywhere from 2 to 6 somewhat evenly spaced holes through pad 7 would work well although the number will be somewhat dependent upon the area of the pad surface. It should also be noted, that the single hole 13 in FIG. 2A could also be conical in shape with the larger opening running through pads 7 , similar to FIG. 2B .
FIG. 3 shows another structural arrangement for accommodating solder volume expansion during reflow. In FIG. 3 , via or cavity 17 is plated with a layer 19 of conductive material, such as, copper. The plated via 17 , shown in contact with pad 7 , is used to make connection to other circuitry. Electrical connection can also be made directly to pad 7 from the surface. In this structural arrangement, pad 7 also acts as an air-cushioned diaphragm which functions to accommodate expanding volume of solder into via 17 during reflow. In this regard, pad 7 is sufficiently thin and elastic so as to flex without rupture in response to the expanding volume of solder during reflow and, then, upon cooling return to its original state, as shown.
FIG. 4 shows a further air-cushioned diaphragm arrangement for accommodating excess volume of solder during reflow. In this arrangement, a flexible insulating layer 21 , such as polyimide, is used as a diaphragm over cavity 23 . A hole or via 25 formed in pad 7 exposes solder ball 5 to layer 21 . During reflow of solder ball 5 , excess volume of solder acts to depress layer 21 downwardly into cavity 23 to accommodate the expanding volume. During cooling, the volume expanded into the cavity via layer 21 is contracted and the air-cushioned diaphragm returns to its original state, as shown.
FIG. 5 shows yet another structural arrangement for accommodating solder volume expansion during reflow. In FIG. 5 , a somewhat porous, deformable layer 27 is exposed to solder ball 5 by way of a hole or aperture 29 . Layer 27 has a top surface that is closed and continuous (non-permeable to solder) and compliant. Upon application of heat to reflow solder ball 5 , excess solder caused by volume expansion during the liquid phase is forced downwardly through hole 29 causing deformable layer 27 to compress to relieve the resultant pressure. The liquid solder on reflow does not enter into the pores or voids of layer 27 since its top surface is non-permeable. Since compression is local to each cell, each cell is closed off from the others. In addition to having the top surface of layer 27 non-permeable, a thin, flexible, non-permeable membrane may also be formed on its surface. Upon cooling, the liquid solder is drawn back up through hole 29 onto pad 7 to its original position, as shown. This is a result of both surface tension and pressure from the deformable layer. Typical materials that may be used for layer 27 are RO2800 Rogers material with a non-permeable membrane, like polyimide, adhered to the top surface such that it acts as a closed-cell material. Cellular silicone can also be converted to a closed-cell structure through adhesion of polyimide to its surface. Thicknesses for layer 27 may range from 75 μm to 100 μm.
FIG. 6 shows yet a further structural arrangement for accommodating solder volume expansion during reflow. In FIG. 6 , a porous, rigid layer 31 is employed, in contrast to the deformable layer 27 in FIG. 5 . In the structural arrangement of FIG. 6 , when solder ball 5 is subjected to heat to reflow the solder, the volume expansion of the solder in the liquid phase is accommodated by being absorbed into the pores or voids of layer 31 . In this regard, the surface of layer 31 is open, i.e., the voids are accessible at the surface portion of the layer exposed to hole 29 . Thus, the voids in regard to layer 31 act as pressure relief reservoirs. Layer 31 may be made, for example, of porous ceramic material with non-wettable voids. Again, upon cooling the liquid solder is drawn up through hole 29 to reform on pad 7 , as shown.
To ensure that the porous area under solder ball 5 is isolated from the porous areas under adjacent solder balls, isolation trench or region 33 may be formed. Isolation region 33 may be made by forming a trench in rigid layer 31 around the region beneath solder ball 5 . The trench may then be backfilled with an isolating material, such as, polyimide or an oxide. The trench may be etched or laser profiled through layer 31 to substrate 3 . Isolation region 33 prevents unwanted migration of the solder, absorbed during reflow, from interacting with the solder absorbed during reflow of an adjacent site. Rigid layer 31 may be made of a conventional ceramic material fabricated to exhibit voids. Layer 31 may be 75 μm to 100 μm thick.
Rather than form isolation region 33 in the porous rigid layer 31 , the substrate, itself, may be used to form an isolation region. This may be achieved by masking a region of substrate 3 around the site of the solder ball that is to act as the isolation region, and then etching back the substrate inside the region. Thereafter the etched region is backfilled with the porous, rigid material.
It will be understood from the foregoing description that various modifications and changes may be made in the preferred embodiment of the present invention without departing from its true spirit. It is intended that this description is for purposes of illustration only and should not be construed in a limiting sense. The scope of this invention should be limited only by the language of the following claims. | 4y
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BACKGROUND OF THE INVENTION
The invention concerns a pressure regulating inlet-and-outlet valve for a space or vessel enclosed by a wall or barrier and sealed off from the outside.
Such pressure regulating inlet-and-outlet valves are well known in the art. Spring-loaded check valves, for example, are used to limit the pressure in sealed spaces in a housing or vessel.
The conventional ball-and-spring check valves have a number of drawbacks. They require several parts that move in relation to one another with narrow tolerances within a valve housing. Furthermore, both over and under pressure cannot be compensated with one and the same valve. These valves react relatively inertly to differences in pressure, and it is impossible to provide for a constant pressure within narrow limits.
SUMMARY OF THE INVENTION
The principal object of the present invention is to improve a pressure regulating inlet-and-outlet valve such that it will have few parts, be simple, sturdy, cost-effective to manufacture, and will react substantially without delay in response to very slight differences in both excess and under pressure.
This object, as well as other objects which will become apparent from the discussion that follows, are achieved, in accordance with the present invention, in a pressure regulating inlet-and-outlet valve of the aforesaid type by providing a valve seal formed by at least one gap spanned by a magnetic field and completely occupied by a "ferrofluidic liquid" (magnetic fluid) confined within the gap by the field. Ferrofluidic seals can withstand a certain difference in pressure. The maximum pressure difference at which the seal will continue to function properly can be determined by appropriate design--e.g., the height of the gap between the core and, for example, one pole shoe of a magnet. The valve seal in accordance with the invention can thus be used to regulate even very slight pressure differences, on the order of 0.02 bars.
At a critical excess or over-pressure the ferrofluidic liquid in the valve seal will uncover a very narrow gap, and the confined and compressed gas (e.g., air) will flow out. At a critical under pressure, due to cooling for example, the valve seal will open in the opposite direction and fresh gas (e.g., air) will enter the housing from the environment. Critical over and under pressures can be very precisely defined, resulting in very precisely controlled pressures within the housing or vessel to which the valve is connected.
One advantage of the valve in accordance with the invention over the known embodiments (such as ball-and-spring check valves) is that very slight differences in both over and under pressure can be compensated with only a single valve component. With respect to the valve's function it should be noted that it will remain open only until the excess pressure has been released. Once the critical situation is compensated, the valve will close again, confining noxious or unpleasant gases in the housing and away from the environment. Foreign contaminants penetrating inside the valve through the inlet/outlet, for example, cannot pass through the ferrofluidic liquid accumulated between the core and the pole shoe. This is especially true of water, which does not mix with ferrofluidic liquid.
Another advantage of the inlet-and-outlet valve according to the invention is that it is easy to clean and to add fresh ferrofluidic liquid.
One preferred embodiment of the present invention has a condenser on the side of the gap facing away from the space being sealed. This component condenses the escaping gas and collects it in a reservoir. The condensed material can be returned to the sealed space through a line.
In order to control larger over and under pressures within a housing it is possible to provide a plurality of gaps arranged in series. The series of gaps makes it possible to use the valve in various applications with different pressures on a modular basis. When the pressure differences are great, the gap can be simply elongated.
The gap can be straight and demarcated on one side by a magnet and on the other by a piece of iron. Manufacture is therefore especially simple. The gap can also be annular.
This approach makes it possible to accommodate a long gap in a narrow space. A labyrinth seal can be positioned upstream toward the space being sealed. Inexpensive known labyrinth seals are available in a wide range of dimensions and can be employed. Although the ferrofluidic liquid will not mix with the liquid found in the space being sealed, a labyrinth seal will provide extra protection against drops of ferrofluidic liquid being forced out of the gap and lost. A rebound plate, for example, can be employed instead of a labyrinth seal and will constitute a cost-effective and effective protector for the ferrofluidic seal.
The labyrinth seal can have at least one drain opening into the space being sealed. The drain will make it possible to subject the ferrofluidic seal to the over pressure prevailing in the space being sealed and for the medium that flows through the labyrinth to return to that space. A rebound plate can also be positioned upstream of the ferrofluidic seal and be provided for practical purposes with drains.
The gap in one advantageous, preferred embodiment of the invention is accommodated in an insert that can be secured to the wall of a housing as a ready to use unit. This design is of particular advantage in view of the economics of manufacturing the wall next to the valve. If the insert screws into the wall and is sealed off from it, no special demands on the dimensional stability of the housing will be necessary. The precise width of the gap between the annular magnet and its core can more easily be established in an insert. When a ready-to-use unit screws into a housing, it is also possible to withstand even comparatively high pressures in comparatively thin-walled housings by employing a plurality of gaps in series.
The magnetic field can be generated by a permanent magnet that demarcates one side of an annular or straight gap. The magnets are magnetized axially and can be secured to two pole shoes that conduct the magnetic flux to the core. This construction is of particular advantage from the aspect of economics when the permanent magnet is a bar magnet accommodated next to a plate of magnetizable material, in conjunction with which it creates a straight gap.
The magnetic field in another preferred embodiment is generated by an electromagnet. In this arrangement it is of advantage to employ the electromagnet to generate a variable and optionally very powerful field, resulting in a better and more precise match between the magnetic forces confining the ferrofluidic liquid and the demands of the particular application--thus providing a variable level of pressure retention.
The preferred embodiments of the present invention will now be described with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of an inlet-and-outlet valve with a rebound plate upstream of the gap.
FIG. 2 is a cross-sectional view of an inlet-and-outlet valve, similar to the valve of FIG. 1 but with a sealing gap upstream of the ferrofluidic seal and with an activated carbon filter inside the air inlet and outlet.
FIG. 3 is a cross-sectional view of an inlet-and-outlet valve with two gaps arranged in series.
FIG. 4 is a cross-sectional view of an inlet-and-outlet valve with a labyrinth seal arranged upstream toward the space being sealed.
FIG. 5 is a graph of the distribution of pressure in an inlet-and-outlet valve according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The pressure regulating inlet-and-outlet valves illustrated in FIGS. 1 through 4 consist essentially of four components. A sealed housing 1 has at least one air inlet and outlet 1.1 and is preferably made from a non-magnetic material such as brass or, even more ideal from the aspect of economy, plastic. An insert 2, threaded, for example, and screwed into a vessel housing wall 10, is also preferably made of brass or plastic. A ferrofluidic seal comprises an axially magnetized annular magnet 3 and two pole shoes 11 that convey the magnetic flux to a core 4. The purpose of the magnetic core 4 is to couple the magnetic flux to pole shoes 11 and to accordingly ensure that a ferrofluidic liquid 7 is confined within a gap 6. The liquid 7 can be a suspension of particles of metal in oil.
The insert 2 illustrated in FIG. 1 accommodates a rebound plate 5 that protects the gap 6 from liquid such as oil splashing out of a space 9 that is being sealed. The housing 1 and core 4 in this embodiment are in two parts, making it possible, for example, to use one and the same housing with inserts and cores that have been lengthened to accommodate a plurality of gaps 6 arranged in series.
FIG. 2 illustrates an inlet-and-outlet valve in accordance with the invention similar to the valve illustrated in FIG. 1 but with the magnetic core 4 and sealed housing 1 in one piece. The core in this version also protects the ferrofluidic seal. This unit, which essentially comprises only four components, is particularly recommended for the manufacture of a single type of inlet-and-outlet valve on a large industrial scale. This embodiment also includes an activated carbon filter 12 concentrically accommodated in the insert 2 and positioned directly upstream of the inlet and outlet 1.1 in the housing 1.
The filter 12 is designed to prevent direct contact with the ferrofluidic liquid. The material must also be made of a material that will not draw the ferrofluidic liquid from the sealing gap between the pole shoe 11 and the core 4. The activated carbon filter 12 can, for example, also be axially separated from its adjacent pole shoe. The filter mitigates the detrimental action of the gases escaping through the gap 6 before they can enter the atmosphere through inlet and outlet 1.1.
FIG. 3 illustrates an inlet-and-outlet valve that is essentially identical with the valve illustrated in FIG. 1, although it is intended to withstand higher and lower pressures and is accordingly provided with a series of two gaps 6.1 and 6.2. The components of this valve are substantially identical in design with those of the valve illustrated in FIG. 1 with the exception that the core 4 and insert 2 are axially longer. This minor change is of particular advantage from the aspect of economy.
The inlet-and-outlet valve illustrated in FIG. 4 has an annular gap 6. Ferrofluidic liquid 7 is protected by a labyrinth seal 8. Labyrinth seal 8 is provided with a drain 8.1 that opens into the space 9 being sealed. The labyrinth seal is positioned upstream of the gap 6 toward the space 9. Labyrinth seals are in themselves known and exist in enough different shapes and sizes to be economical for industrial-scale valve production.
FIG. 5 is a graph of pressure (vertical axis) vs. time (horizontal axis) illustrating how the inlet-and-outlet valve works. Variations in pressure are plotted in terms of varying temperature, which pressure may oscillate around the atmospheric pressure for example.
As the temperature inside the sealed space 9 increases, the pressure will also increase up to a precisely prescribed threshold. As the temperature continues to increase, ferrofluidic liquid 7 will uncover a narrow gap 6, between a pole shoe 11 and the core 4 of the magnet for example, allowing gas to escape through inlet and outlet 1.1 and compensating the pressure. Ferrofluidic liquid 7 will thereafter completely occupy the gap 6 again, sealing the space 9 off from the environment. The opposite procedure will occur when the pressure inside the space decreases. The valve will seal off the space until the pressure decreases to a precisely prescribed lower threshold. A gap 6 will then open in the ferrofluidic seal and allow gas (e.g., air) to flow in from the environment until the pressure is compensated, at which time the valve will close again. The pressures will be compensated to a narrow tolerance, which can be established at precisely 0.02 bars. The advantage is that one and the same pressure regulating inlet-and-outlet valve can be employed to compensate very slight over and under pressures. The valve will remain open until the maximal allowable pressure is established again. If conditions remain stable, the valve will close, confining noxious or unpleasant gases to the sealed space. A valve in accordance with the invention will respond very rapidly to minimal pressure differences. It is simple in design, easy to clean, and very precisely adjustable.
There has thus been shown and described a novel pressure regulating inlet and outlet valve which fulfills all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow. | 4y
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RELATED APPLICATIONS
This application is a Continuation-in-part of co-pending U.S. application Ser. No. 12/897,564, filed on Oct. 4, 2010 claiming priority from U.S. Provisional Application No. 61/329,121, filed on Apr. 29, 2010 both which is incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
The present invention relates generally to the field of keys, and more particularly, to keys with mutually compressible actuating elements.
BACKGROUND OF THE INVENTION
Embodiments of the present invention generally relate to entry security, and particularly to key assemblies and lock assemblies having elements capable of biasing locking pins and mechanical and design characteristics that substantially increase the number of key/lock combinations, thereby inhibiting the unauthorized replication of the key assembly.
Locks are often intended to provide the security of permitting only authorized ingress and/or egress for a given entry. The existence of a locked entry and/or the inability to unlock a locked entry may indicate that unauthorized passage through the entry is prohibited and/or to deter such unauthorized passage. Locking such entries may therefore control when, who, and/or what passes through the entry.
Various attempts may be made to gain unauthorized passage through a locked entry. For example, an individual lacking authorization may attempt to gain entry by breaking the door and/or breaking the lock. However, these actions suffer from many drawbacks, including, for example, the noise associated with breaking the door and/or lock, the resulting visual or audible indication that unauthorized ingress/egress may being occurring or has occurred, the potential need for tools to carry out the act of breaking the door and/or lock, and the time and energy associated with such a break.
Another option for unauthorized entry that may not involve some of the challenges associated with physically breaking the lock or door is duplicating the key that unlocks the lock, or use other devices in an attempt to manipulate, or pick, the lock so as to unlock the lock. Duplicating keys for many types of locks merely requires duplicating the general physical shape of the blade of the key, recreating the profile of key bits and the shape and depth of holes or cavities in the key. Such unauthorized duplication may be achieved by filing, cutting, and/or machining a blank of material, such as a key blank or other blank that is or can be machined or manipulated to suitably match the shape and configuration of the key.
Locks to an entry must, in addition to allowing authorized individuals to enter, have specific key profiles that prevent unauthorized key duplication, either by an unauthorized entrant or an unauthorized professional assembling the duplicate key. Additionally, a variety of top-secret institutions require keys with more combinations that are difficult to duplicate in order to avoid unauthorized entry.
Present day flat blade keys often have depressions of different depths in the key blade or, in the cases of high-security entry, have holes that are of different shapes. Additionally, there are keys having a variety of shapes, such as round cross-sectioned keys; and keys having outward projecting bits; all for the purpose of preventing unauthorized entry and/or unauthorized key duplication.
Thus, a need exists for key assemblies configured to prevent or deter successful unauthorized duplication of the key assembly. Further, a need exists to provide a key assembly that has mechanical properties and design requirements that increase the possible key/lock combinations that would inhibit unauthorized successful duplication of the key assembly, and thereby provide increased security against unauthorized ingress or egress through an entry.
BRIEF SUMMARY OF THE INVENTION
According to an aspect of the invention, a key assembly is provided that comprises a key blade, the key blade having a first surface and a second surface, the key blade configured to be inserted into a mating lock; an aperture in the key blade, the aperture having an axis; a cap having an outer surface, captured in the aperture for continuous axial travel between a first limit extending out of the first surface and a second limit recessed within the aperture; and a base having an outer surface, captured in the aperture for continuous axial travel between a first limit extending out of the second surface and a second limit recessed within the aperture; wherein the base is biased away from the cap.
According to another aspect of the invention, a key assembly is provided wherein the key is positioned in a lock assembly, the key assembly, comprising: a key blade, the key blade having a first surface and a second surface, the key blade configured to be inserted into the lock; an aperture in the key blade, the aperture having an axis; a cap having an outer surface, captured in the aperture for continuous axial travel between a first limit extending out of the first surface and a second limit recessed within the aperture; and a base having an outer surface captured in the aperture for continuous axial travel between a first limit extending out of the second surface and a second limit recessed within the aperture; wherein the base is biased away from the cap; the lock assembly having a barrel, a column extending from the barrel, and a cylinder configured to rotate within the barrel, the cylinder including a guide way; the column having an aperture configured to receive the sliding movement of a first pin housing, the first pin housing configured to receive the sliding movement of a first pin; the cylinder including a cylinder aperture configured to receive the sliding movement of a second pin housing, the second pin housing configured to receive the sliding movement of a second pin, the first pin being inwardly biased against the second pin so as to place the first pin in the cylinder aperture when the key assembly is not positioned in the lock assembly; the key assembly configured to outwardly bias and move the cap or the base against the first pin when the key assembly is positioned in the lock assembly so that the second pin and the second pin housing are located inside the cylinder and the first pin and first pin housing are located outside of the cylinder.
Additionally, according to another aspect the invention provides, in combination, a key assembly comprising: a key blade, the key blade having a first surface and a second surface, the key blade configured to be inserted into a mating lock; an aperture in the key blade, the aperture having an axis; a cap having an outer surface, captured in the aperture for continuous axial travel between a first limit extending out of the first surface and a second limit recessed within the aperture; and a base having an outer surface captured in the aperture for continuous axial travel between a first limit extending out of the second surface and a second limit recessed within the aperture; wherein the base is biased away from the cap; and a mating lock assembly, the lock assembly having a barrel, a column extending from the barrel, and a cylinder configured to rotate within the barrel, the cylinder including a guide way; the column having an aperture configured to receive the sliding movement of a first pin housing, the first pin housing configured to receive the sliding movement of a first pin; the cylinder including a cylinder aperture configured to receive the sliding movement of a second pin housing, the second pin housing configured to receive the sliding movement of a second pin, the first pin being inwardly biased against the second pin so as to place the first pin in the cylinder aperture when the key assembly is not positioned in the lock assembly; the key configured to outwardly bias and move the cap or the base against the first pin when the key assembly is positioned in the lock assembly so that the second pin and the second pin housing are located inside the cylinder and the first pin and first pin housing are located outside of the cylinder.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
The present invention will be understood and appreciated more fully from the following detailed description, taken in conjunction with the drawings in which:
FIG. 1 illustrates an exploded view of a key assembly according to an embodiment of the present invention;
FIG. 2 illustrates a perspective view of a key assembly and a lock assembly according to an embodiment of the present invention;
FIG. 3A illustrates a cross sectional view of the actuation element shown in FIG. 1 according to an embodiment of the present invention; and FIG. 3B illustrates another embodiment containing a ball.
FIG. 4 illustrates a cross sectional perspective view of a key assembly engaging a lock assembly according to an embodiment of the present invention;
FIG. 5 illustrates a cross sectional view of a lock assembly prior ( 5 a ) to the insertion of a mating key assembly into a lock assembly containing a depression in the key way; FIG. 5 b shows the insertion of the key; and FIG. 5 c shows the key blade lifting a pin in the lock assembly according to an embodiment of the invention;
FIG. 6 a illustrate a cross sectional view of a key assembly having multiple actuation elements positioned in a lock assembly according to an embodiment of the present invention. 6 b illustrates an enlarge view of an actuation element in FIG. 6 a engaging a second pin according to an embodiment of the present invention. 6 c illustrates a partial cross sectional view of key assembly having a contoured cap posited in a lock assembly that includes a second pin having a mating contoured tip according to an embodiment of the present invention;
FIG. 7 illustrates a cross sectional view of a section of the lock assembly in which the key assembly has been inserted into the lock assembly according to an embodiment of the present invention;
FIG. 8 illustrates a cross sectional view of a section of the lock assembly having a lower pin assembly in which the key assembly has been inserted into the lock assembly according to an embodiment of the present invention;
FIG. 9 a illustrates a cross sectional view of a section of the lock assembly having a lower pin assembly in which the key assembly has been inserted into the lock assembly according to an embodiment of the present invention. 9 b illustrates a cross sectional view of a section of the key assembly having an actuator pin extending from the cap of the actuation element according to an embodiment of the present invention;
FIG. 10 illustrates a cross sectional view of a key assembly and a lock assembly in which the actuation elements include a protruding ball according to an embodiment of the present invention;
FIG. 11 illustrates a cross sectional view of a key assembly and lock assembly in which the protruding balls extend from the base of the actuation elements and the lock assembly includes a lock actuation assembly according to an embodiment of the present invention:
FIG. 12 is an exploded view of an embodiment of the key blade where the biasing elements are magnets and mechanical;
FIG. 13 is an illustration of an embodiment of the key and lock combination having both magnetic and mechanical biasing and locking elements and pins including a magnetic locking safety pin coaxial and diametrically opposed to a magnetic locking pin slidably movable in the lock's column; and
FIG. 14 is a magnified view of an embodiment of the key and lock combination in FIG. 13 , illustrating the magnetic biasing elements in the embedded floating elements of the key blade, forcing the locking pin of the column and the locking safety pin of the barrel to their respective positions.
The foregoing summary, as well as the following detailed description of the preferred embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the preferred embodiments of the present invention, the drawings depict embodiments that are presently preferred. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 illustrates an exploded view of a key blade ( 112 ), the key blade ( 112 ) having a first surface ( 106 ) and a second surface ( 108 ), the key blade configured to be inserted into a mating lock; an aperture ( 109 ) in the key blade ( 112 ), the aperture having an axis; a cap ( 120 ) having an outer surface ( 123 , FIG. 3A ), captured in the aperture ( 109 ) for continuous axial travel between a first limit extending out of the first surface ( 106 ) and a second limit recessed within the aperture ( 109 ); and a base ( 124 ) having an outer surface ( 131 ), captured in the aperture ( 109 ) for continuous axial travel between a first limit extending out of the second surface ( 108 ) and a second limit recessed within the aperture ( 109 ); wherein the base ( 124 ) is biased away from the cap ( 120 ). The key blade 112 may have various different general shapes and sizes, such as, for example, having a generally rectangular, cylindrical, square, triangular, or trapezoidal cross-section, among others.
The blade 112 may also include recesses and protrusions forming one or more outwardly projecting key bit 116 . The key bit 116 may be located at various locations along the blade 112 , including for example along the sides 110 , first or second surfaces 106 , 108 , or in one or more key guide ways 118 in the blade 112 . The key blank 102 may be constructed from a variety of different resilient materials, such as, for example, metallic materials, including, but not limited to, metal, brass, bronze, stainless steel, or a combination thereof.
FIG. 2 illustrates a perspective view of a key assembly 100 and a lock assembly 200 according to an embodiment of the present invention. The lock assembly 200 includes a column 202 and a barrel 204 . The barrel 204 includes a drum 206 that houses and permits the rotational movement of a cylinder 208 . The cylinder 208 includes a lock guide way 210 that is configured to receive the insertion and position mating key blade 112 of the key assembly 100 . For example, the shape of the lock guide way 210 may be similar to that of the cross-sectional shape of the blade 112 and may include recesses, grooves, or other characteristics that generally complement and mate with those of the key blade 112 .
FIG. 3A illustrates a cross sectional view of an actuation element 104 according to an embodiment of the invention shown in FIG. 1 . The actuation element may include a cap 120 having an outer surface, a base 124 having an outer surface, wherein the cap 120 is biased away from the base 124 with the aid of a biasing means 122 such as a spring in one embodiment, or an elastic material, in another embodiment, or an identical-pole facing magnets, foam rubber, elastic cones or other similar mechanisms for biasing the cap 120 from the base 124 . According to one embodiment, the biasing means 122 may be a spring. However, different embodiments of the present invention allow for the use of different actuators, such as, for example, magnets and air pressure, or a combination thereof. The spring actuator 122 shown in FIGS. 3A (and 3 B) may provide a biasing force that may allow for the continuous altering in the linear distance between an upper portion of the cap 120 and the base 124 , regardless of whether the cap 120 or the base 124 is anchored by the aperture 109 in one embodiment, or the lock guide way 210 in another embodiment. For example, when the biasing means 122 is a spring, when the spring is extended, the distance between the upper surface portion of the cap 120 and the base 124 is greater than if the spring was compressed.
According to the embodiment illustrated in FIG. 3A , the cap 120 and base 124 may be configured to provide a sliding engagement that allows for the continuous relative movement of the cap 120 and/or base 124 relative to each other. For example, the cap 120 may include at least one lower protrusion 121 that extends downwardly from an upper portion 123 of the cap 120 . At least a portion of the lower protrusion 121 may be configured to be received in a bore 125 of the base 124 . The lower protrusion 121 may include outwardly extending tabs 127 that mate with inwardly extending lips 129 of the base 124 that, in one embodiment retain the cap 120 and base 124 in a sliding engagement. Moreover, upper portion of the cap 123 , the lower protrusion 121 and the inwardly extending base lips 129 define a channel capable of being captured by the aperture 109 positioned in key blade's 112 . Further, this engagement assists in another aspect, in retaining the biasing means 122 within the actuation element 104 , as shown in FIG. 3A . Therefore, in one embodiment, when the actuation element 104 attempts to extend the distance between an upper portion of the cap 120 and the base 124 , the inwardly extending lips of the base 124 and the outwardly extending tabs of the cap 120 provide interference that prevents the cap 120 from separating from the base 124 . The position of the tabs 127 and/or lips 129 may thus limit the distance the cap 120 may be biased away from the base 124 , the base 124 may be continuously biased away from the cap 120 and/or the cap 120 and the base 124 may be biased away from each other. Further, the tabs 127 and lip 129 may limit the distance the cap 120 and/or base 124 may extend from the first or second surface 106 , 108 . In one embodiment, a shelf 111 extending radially inside the aperture 109 engages the channel created by upper portion of the cap 123 , the lower protrusion 121 and the inwardly extending base lips 129 , thereby limiting the continuous axial motion of the element 104 , between predetermined limits above surface 106 and below surface 108 . In one embodiment, element 104 may freely and continuously move from a position wherein the cap 120 extends about 1 mm above surface 106 , to a position in which the base 124 extends about 1 mm below surface 108 . In one embodiment, the element 104 , is referred to as floating, or a floating element, between the upper and lower limits, capable of being continuously positioned anywhere along the aperture 109 axis with the cap 120 and the base 124 capable of being biased away from each other in a continuous manner, regardless of whether the cap 120 , or the base 124 are anchored. In one embodiment, the terms actuation element and floating element are interchangeable.
Additionally, the cap 120 and/or base 124 may be sized or configured to limit how close the upper portion of the cap 120 can come to the outer lower surface 131 of the base 124 . For example, according to the embodiment shown in FIG. 3A , the outer portion 123 of the cap 120 may be sized to allow for an interference with at least a portion of the base 124 at the lips 129 so as to limit the distance the cap 120 may travel when a compression force is applied to the actuator element 104 . These limitations in the distance the cap 120 may extend inwardly or outwardly from the base 124 according to certain embodiments of the present invention may provide an additional security against successful, unauthorized duplication of the key assembly 100 .
As shown in FIG. 1 , the floating element 104 may be positioned along the blade 112 of the key blank 102 . According to one embodiment, element 104 may be captured in an aperture 109 defined by an opening in the key blank 102 thereby defining an internal surface having a shelf thereon 111 . The shelf 111 may be located anywhere along the axial dimension of the aperture 109 and may be used to capture the cap 120 , the base 124 or the channel created by upper portion of the cap 123 , the lower protrusion 121 and the inwardly extending base lips 129 , of floating element 104 . The aperture 109 may be a continuous aperture or may include one or more counter bores.
The precise location of each floating element 104 and the number of floating elements 104 on the blade 112 may vary. Additionally, the blade 112 may include one or more floating elements 104 that may have the caps 120 positioned above or recessed in the first surface 106 , or the base 124 below or recessed in the second surface 108 , or a combination thereof. According to an embodiment illustrated in FIG. 1 , the cap 120 may be positioned along the first surface 106 . The base 124 may be positioned at, below or recessed to the second surface 108 . According to other embodiments, both the cap 120 and the base 124 are configured to be able to be biased away from each other and/or the adjacent surface of the blade 112 .
Accordingly and in one embodiment, provided herein is key assembly 100 having a key blade 112 , the key blade 112 having a first surface 106 and a second surface 108 , the key blade 112 configured to be inserted into a mating lock 200 ; an aperture 109 in the key blade 112 , the aperture having an axis; a cap 120 having an outer surface 123 , captured in the aperture 109 for continuous axial travel between a first limit extending out of the first surface 106 and a second limit recessed within the aperture 109 ; and a base 124 having an outer surface 131 , captured in the aperture 109 for continuous axial travel between a first limit extending out of the second surface 108 and a second limit recessed within the aperture 109 ; wherein the base 124 is biased away from the cap 120 .
FIG. 4 illustrates a cross sectional perspective view of a key assembly 100 engaging a lock assembly 200 according to an embodiment of the present invention. The column 202 may include at least one bore 222 that is configured for the sliding movement of a first pin housing 224 . An outer end of bore 222 may be closed, such as, for example, through the use of a plug 228 . An outer actuator 230 , such as a spring, may inwardly bias the first pin housing 224 , such as, for example, biasing the first pin housing 224 toward the cylinder 208 .
A first pin 226 may be positioned for a sliding engagement within the first pin housing 224 . According to on embodiment, the first pin 226 may be inwardly biased from the pin housing 224 by an inner pin actuator 232 . According to an embodiment, the inner pin actuator 232 may be a spring. However, other actuators 232 may be used to bias the first pin 226 , including, for example, a magnet, an electromagnet, air pressure and the like in other embodiments. According to the embodiment illustrated in FIG. 4 , a distal end of the first pin 226 may engage the inner pin actuator 232 .
As shown in FIG. 4 , the cylinder 208 includes at least one cylinder aperture 240 configured for the sliding movement of a second pin housing 242 . The second pin housing 242 may be configured to receive and allow the sliding movement of a second pin 244 . The second pin 244 includes a second pin upper surface 243 and a second pin lower surface 246 . The second pin upper surface 243 may be configured for engagement with the distal end 227 of the first pin 226 .
Turning now to FIG. 5 illustrating a cross sectional view of a lock assembly 200 prior to the insertion and positioning of a mating key assembly 100 according to an embodiment of the invention. As shown, ( FIG. 5 a ) in one embodiment when a key blade 100 is not inserted into the lock assembly 200 , the outer actuator 230 biases the first pin housing 224 and first pin 226 downwardly or inwardly. Alternatively or in addition to the outer actuator 230 , the inner actuator 232 may also downwardly or inwardly force or bias the first pin 226 . These forces may move the first pin housing 224 and/or first pin 226 in a downwardly direction, so that at least a portion of the first pin housing 224 and/or first pin 226 enter into the cylinder 208 aperture 240 while another portion of the first pin housing 224 and/or first pin 226 , respectively, remains in the drum 206 , thereby preventing the rotation of cylinder 208 . As shown in FIG. 5 a , in one embodiment of the invention, when a depression 250 , is disposed in the guide way 210 of the cylinder 208 of lock assembly 200 , cylinder 208 aperture 240 is configured to prevent the lower pin housing 242 from sliding into the depression 250 , likewise, pin housing 242 is configured to limit the downward motion of pin 244 into depression 250 in the guide way 210 of cylinder 208 in lock assembly 200 . As shown in FIG. 5 b , pin housing 242 and pin 244 are beveled in their distal end at an angle that is configured to interact with the angle at the distal end of key blade 112 , such that sliding key blade 112 into the guide way 210 engages the beveled distal end of pin housing 242 ( FIG. 5 b ), lifting the housing 242 from guide way 210 and then likewise proceed to engage pin 244 ( FIG. 5 c ) and lift pin 244 from guide way allowing the pin to align with floating element 104 (not shown). Absent the configuration shown in FIG. 5 , pin housing 242 and pin 244 would slide into depression 250 and prevent the insertion of key blade 112 , thereby, through the use of the right angle in beveling both the key blade 112 and the distal ends of pin housing 242 and pin 244 , in combination with a lock assembly 200 having a depression 250 disposed in the guide way 210 of the cylinder 208 , the inventors have added to the complexity and thereby the security of the key/lock combination.
The presence of the first pin housing 224 and/or first pin 226 in both the cylinder aperture 240 and the drum 206 of the column 202 creates an interference that prohibits the rotational movement of the cylinder 208 about the barrel 204 . For the embodiment illustrated in FIG. 4 , when a key assembly 100 is positioned into the lock assembly 200 , and the floating element 104 is properly positioned on the blade 112 so that the cap 120 in floating element 104 engages the second pin housing and/or pin 242 , 244 , then when the biasing means 122 , such as a spring in one embodiment exerts the correct amount of force to counter the forces exerted on the actuator (such as forces created by outer actuator 230 and inner pin actuator 232 ) and to move at least a portion of the floating element 104 , such as for example the cap 120 , a proper distance, the first pin housing 224 and/or first pin 226 may be forced outside of the cylinder 208 without a portion of the second pin housing 242 and/or second pin 244 entering the bore 222 . If these criteria are satisfied, the first pin housing and pin 224 , 226 respectively and second pin housing and pin 242 , 244 respectively may be positioned so as to not inhibit the rotational movement of the cylinder 208 about the barrel 204 . If however the biasing means 122 in floating element 104 does not exert adequate force in one embodiment; and/or in another embodiment, the location of the base 124 along the aperture 109 axis is not anchored precisely as necessary; and/or, in another embodiment, the cap 120 is not biased away from the base 124 to a sufficient distance; or any combination thereof in other certain embodiments, at least a portion of the first pin housing 224 and/or first pin 226 may continue to be extended into the cylinder aperture 240 while the remainder of the first pin housing 224 and/or first pin 226 is in bore 222 of the column 202 , thereby creating an interference that inhibits the rotational movement of the cylinder 208 . Conversely, if the biasing means such as a spring in one embodiment exerts too large a force and/or in another embodiment, the location of the base 124 along the aperture 109 axis is not anchored precisely as necessary; and/or, in another embodiment, the cap 120 is biased away from the base 124 to an extended distance; or any combination thereof in other certain embodiments, at least a portion of the second pin housing 242 and/or second pin 244 may be pushed into bore 222 of the column 202 while the remainder of the second pin housing 242 and/or second pin 244 remains in the cylinder aperture 240 , thereby creating an interference that inhibits the rotational movement of the cylinder 208 .
FIG. 5 illustrates the second pin housing 242 and second pin 244 touching the bottom of the lock guide way 210 prior to the insertion of the key assembly 100 . According to such an embodiment, the second pin housing 242 and second pin 244 and/or key assembly 100 may be configured to allow the second pin housing 242 and second pin 244 to be lifted outwardly when a key assembly 100 is inserted into the lock assembly 200 , such as, for example, through the use of tapered surfaces. Further, the second pin housing 242 and second pin 244 need not be touching the bottom of the lock guide way 210 prior to the corresponding key assembly 100 being inserted into the lock assembly 200 . Moreover, the second pin housing 242 and second pin 244 may be in the lock guide way 210 but above the bottom of the lock guide way 210 before the insertion of the key assembly 100 so as to minimize possible interference with the ability to position the key assembly 100 into the lock assembly 200 .
FIG. 6 a illustrate a cross sectional view of a key assembly 100 having multiple floating elements 104 a , 104 b rotatably symmetrical, positioned in a lock assembly 200 according to an embodiment of the present invention. FIG. 6 b illustrates an enlarge view of floating element 104 a in FIG. 6 a engaging a second pin 244 according to an embodiment of the present invention. As shown, floating elements 104 a and 104 b may have caps 120 a , 120 b respectively positioned along or about the first and second surfaces 106 , 108 , respectively, of the key blade 112 . While floating elements 104 a , 104 b are illustrated as being next to each other, in certain other embodiments, floating elements 104 a , 104 b may be spaced apart at different locations along the length and/or width of the blade 112 . Further, although FIGS. 6 a , 6 b illustrate only a mating cylinder aperture 240 , pins 226 , 244 respectively, pin housings 224 , 242 respectively and actuators 230 , 232 respectively for one of the floating elements 104 a , the lock assembly 200 may also include similar components for other floating elements 104 b.
As illustrated in FIG. 6 b , floating elements 104 a , 104 b may be positioned in apertures 109 a , 109 b respectively that have counter bores having a depth that allows the upper surface of the caps 120 a , 120 b and bottom surface of the base 124 a , 124 b to be flush, above, or recessed in the respective first or second surface 106 , 108 of key blade 112 .
According to the embodiment illustrated in FIGS. 6 a , 6 b , when the key assembly 100 is properly positioned within lock assembly 200 , floating element 104 a , cylinder aperture 240 , and bore 222 of the column 202 are aligned. The biasing means, such as a spring in one embodiment 122 a of the floating element 104 a may then be actuate. The extent the biasing means 122 a such as an identical-pole facing magnet in certain embodiment may be actuated depend in one embodiment on several design criteria. For example, the size and force of the biasing means 122 a may be countered by the size and force of the outer actuator 230 and/or inner pin actuator 232 , alone or in combination. Additionally, the tabs 127 a of the cap 120 a and lips 129 a of the base 124 a may limit the distance the cap 120 a may be biased away from the base 124 a . Each of these design criteria may be implemented in precisely controlling the distance or amount the may move the first pin housing 224 and first pin 226 and/or second pin housing 242 and second pin 246 so as to allow for the cylinder 208 to be rotated, and thereby operate the lock assembly 200 .
In one embodiment, the key blade may comprise a combination of actuating means such as magnets and springs. FIG. 12 , shows an exploded view of such embodiment having four ( 4 ) symmetrically positioned floating elements wherein floating element ( 104 a ) in the key blade ( 112 ), where key blade ( 112 ) is having a first surface and a second surface ( 108 ), the key blade configured to be inserted into a mating lock; a first aperture ( 109 a ) in the key blade ( 112 ), the aperture having an axis; a cap ( 120 a ) having an outer surface ( 123 a , FIG. 3 ), captured in the aperture ( 109 a ) for continuous axial travel between a first limit extending out of the first surface ( 106 ) and a second limit recessed within the aperture ( 109 a ); and a base ( 124 a ) having an outer surface ( 131 a ), captured in the aperture ( 109 a ) for continuous axial travel between a first limit extending out of the second surface ( 108 ) and a second limit recessed within the aperture ( 109 a ); wherein the base ( 124 ) is biased away from the cap ( 120 ) with a biasing means ( 122 a ) which is a spring with ball bearing ( 260 a and 260 b ) disposed on opposite sides of the spring ( 122 a ) and protruding from both the base ( 124 a ) and the cap ( 120 a ); and wherein floating element ( 104 b ) is embedded in a second aperture ( 109 b ) in the key blade ( 112 ), the second aperture ( 109 b ) having an axis; a cap ( 120 b ) having an outer surface ( 123 b ), captured in the second aperture ( 109 b ) for continuous axial travel between a first limit extending out of the first surface ( 106 ) and a second limit recessed within the aperture ( 109 a ); and a base ( 124 b ) having an outer surface ( 131 b ), captured in the second aperture ( 109 b ) for continuous axial travel between a first limit extending out of the second surface ( 108 ) and a second limit recessed within the second aperture ( 109 b ); wherein the base ( 124 b ) having a magnet ( 122 b ′) associated therewith is biased away from the cap ( 120 b ) having a magnet ( 122 b ″) associated therewith, the magnets (,) positioned with the same poles facing facing adjacent surfaces thus creating a repelling force and biasing the cap ( 120 b ) from the base ( 124 b ).
In one embodiment, provided herein is a key assembly ( 100 ) comprising: a key blade ( 112 ), the key blade being substantially flat and having a first surface ( 106 ) and a second surface ( 108 ), the key blade configured to be inserted into a mating lock ( 200 ); an aperture in the key blade ( 109 ), the aperture having an axis; a cap ( 120 ) having an outer surface ( 130 ), captured in the aperture ( 109 ) for continuous axial travel between a first limit extending out of the first surface ( 106 ) and a second limit recessed within the aperture ( 109 ); and a base ( 124 ) having an outer surface ( 131 ), captured in the aperture ( 109 ) for continuous axial travel between a first limit extending out of the second surface ( 108 ) and a second limit recessed within the aperture ( 109 ); and a magnet ( 122 ) associated with the base ( 124 ), the cap ( 120 ) or both, the magnet having sufficient magnetic strength to attract or repel a movable part in the key blade ( 112 ), or the lock ( 200 ) from a locking position to an unlocking position in the lock ( 200 ), or in both the key ( 100 ) and the lock ( 200 ).
For example, in the embodiment illustrated in FIGS. 6 a , 6 b , the biasing means, 122 a such as a spring in one embodiment, may activate to allow cap 120 a to be biased outwardly against the mating second pin housing 242 and/or second pin 244 . Whether the cap 120 a engages either the second pin housing 242 , the second pin 244 , or both, may be determined by the size, shape, and/or configuration of the mating surfaces of the cap 120 a , second pin housing 242 , and second pin 244 . For example, as shown in FIGS. 6 b , the relative sizes of the cap 120 a , second pin housing 242 , and second pin 244 allow the cap 120 a to directly engage both the second pin housing 242 and second pin 244 .
Additional combinations, and thereby security may be provided by requiring that the second pin housing 242 and second pin 244 mate a specific surface configuration of the cover 120 a . For example, FIG. 6 c illustrates a partial cross sectional view of key assembly 1100 having a contoured cap 1120 a posited in a lock assembly 1200 that includes a second pin 1244 having a mating contoured tip 1245 according to an embodiment of the present invention. In the embodiment shown in FIG. 6 c , the use of first and second pin housings have been eliminated. Therefore, the column 1202 includes a drum 1206 configured for the placement and sliding movement of a first pin 1226 , and the cylinder 1208 includes an aperture 1240 configured to receive and allow the sliding movement of a second pin 1244 . As illustrated, the second pin 1244 includes a tip 1245 that is configured to mate with the contoured surface of the cap 1120 a so that, when engaged, a portion of the tip 1245 fits within a recess 1125 in the cap 1120 a . If the portion of the tip 1245 were too large to properly fit all the way within the recess 1125 and thus not mate the recess 1125 , the second pin 1244 would sit too high on floating element 1104 a when the cap 1120 a is biased away from the base 1124 a , resulting in at least the upper surface 1243 of the second pin 1244 extending into the aperture 1222 of the column 1202 , thereby creating an interference that prohibits the rotational movement of the cylinder 1208 about the barrel 1204 . Conversely, if the size of the recess 1125 is too large and/or too deep, the second pin 1244 may sit too deep in the recess 1125 , resulting in the second pin 1244 being drawn to far into the floating element 1104 a when the cap 1120 a is biased away from the base 1124 a , resulting in a portion of the first pin 1226 being moved inwardly so that the first pin 1226 is in both in the drum 1206 of the cylinder 1208 and the aperture 1222 of the column 1202 . The presence of the first pin 1226 in both the bore 1222 of the column 1202 and the aperture 1240 of the cylinder 1208 creates an interference that inhibits the rotational movement of the cylinder 1208 , and thereby prohibits unlocking of the lock. Therefore, even a slight error in sizing in an unauthorized attempt to replicate and use the key assembly of the present invention unsuccessful.
Referencing FIGS. 6 a , 6 b , the second pin housing 242 and/or second pin 244 may then be moved against the force of the outer actuator 230 and/or inner pin actuator 232 to move the first pin housing 224 and first pin 226 into the bore 222 of the column 202 while the second pin housing 242 and/or second pin 244 remain in the cylinder aperture 240 . More specifically, the engagement between the first pin housing and pin 224 , 226 with the second pin housing and pin 242 , 244 occurs at a distance equal to the diameter of the cylinder 208 so that the cylinder 208 can be rotated without prohibitive interference from the first pin housing and pin 224 , 226 and the second pin housing and pin 242 , 244 . This requires precise forces from the biasing means 122 such as a spring in one embodiment, and actuators 230 , 232 and tight tolerances for at least the fixed location of the floating element 104 along the aperture 109 axis, pins 226 , 244 , and pin housings 224 , 242 . Once the key assembly 100 is allowed to rotate in the cylinder 208 , the key assembly 100 may operate as a traditional key to unlock the lock assembly.
Different types of actuators for biasing means 122 , outside actuator 230 , and/or inner pin actuator 232 may be used. More specifically, although the biasing means 122 , and actuators 230 , and 232 are illustrated in FIG. 6 a as springs, other types of actuators may be used, for example, a magnet or air pressure, among others. Moreover, biasing means 122 , and actuators 230 , and 232 may each individually provide a force alone or in conjunction with another biasing means. For example, in embodiments in which the biasing means 122 is an identical pole-facing magnet, a mating magnet in the locking assembly 200 may have a polarity that is identical that of the outer surface of biasing means 122 in the key assembly 100 , and thereby be rejected by the actuator 122 when the corresponding key assembly 100 is properly positioned in the lock assembly 200 .
Further, rather than provide separate magnets, components of the floating element 104 , such as the cap 120 , among others, and components of the lock assembly, such as, for example, the second pin 242 , among others, may be construction from the necessary metallic materials or be imparted with a specific polarity for floating of the lock assembly 200 .
Reference is made to FIGS. 12 and 13 , providing ( FIG. 12 ) a key assembly 100 positioned in a lock assembly 200 ( FIG. 13 ), the key assembly 100 , comprising wherein floating element ( 104 a ) in the key blade ( 112 ), where key blade ( 112 ) is having a first aperture ( 109 a ) in the key blade ( 112 ), the aperture having an axis; a cap ( 120 a ) having an outer surface ( 123 a , FIG. 3 ), captured in the aperture ( 109 a ) for continuous axial travel between a first limit extending out of the first surface ( 106 ) and a second limit recessed within the aperture ( 109 a ); and a base ( 124 a ) having an outer surface ( 131 a ), captured in the aperture ( 109 a ) for continuous axial travel between a first limit extending out of the second surface ( 108 ) and a second limit recessed within the aperture ( 109 a ); wherein the base ( 124 ) is biased away from the cap ( 120 ) with a biasing means ( 122 a ) which is a spring with a ball bearing ( 260 a ) protruding from both the cap ( 120 a ); and wherein floating element ( 104 b ) is embedded in a second aperture ( 109 b ) in the key blade ( 112 ), the second aperture ( 109 b ) having an axis; a cap ( 120 b ) having an outer surface ( 123 b ), captured in the second aperture ( 109 b ) for continuous axial travel between a first limit extending out of the first surface ( 106 ) and a second limit recessed within the aperture ( 109 a ); and a base ( 124 b ) having an outer surface ( 131 b ), captured in the second aperture ( 109 b ) for continuous axial travel between a first limit extending out of the second surface ( 108 ) and a second limit recessed within the second aperture ( 109 b ); wherein the base ( 124 b ) having a magnet ( 122 b ′) associated therewith is biased away from the cap ( 120 b ) having a magnet ( 122 b ″) associated therewith, the magnets ( 122 b ′, 122 b ″) are positioned with identical poles facing adjacent surfaces thus creating a repelling force and biasing the cap ( 120 b ) from the base ( 124 b ). As shown in FIG. 13 , lock assembly 200 having a barrel 204 , a column 202 extending from the barrel 204 , and a cylinder 208 configured to rotate within the barrel 204 , the cylinder 208 including a guide way 210 ; the column 202 having an bore 222 configured to receive the sliding movement of a first pin housing 224 a , the first pin housing 224 a configured to receive the sliding movement of a first pin 226 a (not shown); the cylinder 208 including a cylinder aperture 206 a (not shown) configured to receive the sliding movement of a second pin housing 242 a , the second pin housing 242 a configured to receive the sliding movement of a second pin 244 a (not shown, the first pin 226 a being inwardly biased against the second pin 244 a so as to place the first pin 226 a in the cylinder aperture 206 when the key assembly 100 is not positioned in the lock assembly 200 ; the key assembly 100 configured to outwardly bias and move the cap 120 b or the base 124 b against the first pin 226 a using the magnetic biasing force of floating element 104 b when the key assembly 100 is positioned in the lock assembly 200 so that the second pin 244 a and the second pin housing 242 a are located inside the cylinder 208 and the first pin 226 a and first pin housing 224 are located outside of the cylinder 208 . In certain embodiment the second pin and pin housing are magnetic and the biasing of the second pin is done by the magnetic elements in the key blade such that absent the magnetic force generated by the magnets in the floating element, the lock remains in a locking position.
In another embodiment, provided herein is a lock assembly 200 comprising: a barrel 204 ; a column 202 extending from the barrel, the column having at least two column apertures 222 a , 222 b ; a cylinder 208 configured to rotate within the barrel, the cylinder including a guide way 210 sized and configured to receive a key blade 112 , the cylinder 208 including a cylinder aperture axially registered with the column aperture 222 a when the lock assembly is locked, and movable out of registration with the column aperture with the key blade to unlock the lock assembly; a first and a second pin captured by one of the cylinder and the column, the pins having a first portion slidable in the cylinder aperture and a second portion slidable in the column aperture, the pins normally being biased to a locking position with the first portion within the cylinder aperture and the second portion within the column aperture to lock the cylinder relative to the barrel; a magnetically influenced part associated with the first pin, the magnetically influenced part being movable responsive to a magnetic field provided in the guide way to move the first pin to an unlocking position entirely outside one of the cylinder aperture and the column aperture; and a mechanically influenced part associated with the second pin, the mechanically influenced part being movable responsive to a non-magnetic force provided in the guide way to move the second pin to an unlocking position entirely outside one of the cylinder aperture and the column aperture.
In one embodiment, locking safety pin is non-aligned with any locking pin in column 202 . Accordingly and in another embodiment, when key blade 112 , comprises floating elements 104 a , 104 b , 104 n in key blade 112 , one floating element having a magnet biasing means (see FIGS. 13 , 14 ) will bias the cap 120 or the base 124 against the locking pin slidably movable in the column 202 aperture 222 , while its symmetric counterpart will repel or attract the safety locking pin thus allowing movement of the cylinder 208 in the barrel 206 . As shown in FIG. 14 , column 202 comprises an additional aperture containing a mechanically biased locking pin, a mechanically biased safety locking pin located within the cylinder and extending within an aperture located in the barrel 208 and an additional magnetic or non-magnetic locking pin.
In one embodiment the magnetically influenced part of either the locking pin or the locking safety pin is integral with the pin and is positioned to repel or attract a magnetic field provided in the keyway. In one embodiment, the magnetically influenced part is associated with the safety locking pin and is slidable within the cylinder aperture adjacent to the keyway and is non-aligned with the locking key. In another embodiment the first locking pin is normally biased into its locking position by a resilient element. In one embodiment, the second column aperture 222 b is generally coaxial with the first column aperture and diametrically opposed to the first column aperture. In another embodiment, the magnet is movable normal to the direction of insertion of the key blade in the guide way.
In one embodiment, the magnet 122 is further defined as a first magnet 122 ′, the invention further comprising a second magnet 122 ″ associated with the base or the cap, the second magnet being positioned to repel the first magnet normal to the direction of insertion of the key blade in the guide way.
In another embodiment, the biasing means used to move the locking pins is a magnet that is further defined as a first magnet 122 b ′, the invention further comprising a second magnet 122 b ″ associated with the base or the cap, wherein the first and second magnets being movable with respect to the other magnet, the second magnet being positioned to be repelled by or repel the first magnet normal to the direction of insertion of the key blade in the guide way. In another embodiment the repelling magnets bear between the key blade and the pin to bias the pin into its unlocking position.
For embodiments in which air pressure is used as an actuator, the floating element 104 may include at least one air passageway that is sized to deliver a predetermined amount of pressure to counter the pressure needed to be overcome by the floating element 104 to properly position the first and second pin housings 224 , 242 and first and second pins 226 , 244 along the interface of cylinder 208 and barrel 204 so as to allow the cylinder 208 to rotate.
According embodiments of the present invention, when in the locked position prior to the insertion of a key assembly 100 , rather than creating an inference by moving a portion of the first pin housing 224 and/or first pin 226 into the cylinder aperture 240 , a portion of the second pin housing 242 and/or second pin 244 may instead be drawn into the bore 222 of the column 202 while another portion of the second pin housing 242 and/or second pin 244 , respectively, remains in the cylinder aperture 240 . According to such an embodiment, the floating element 104 may have a polarity opposite to a polarity in the lock assembly 200 that may draw the second pin housing 242 and/or second pin 244 out of the aperture 240 while retaining the first pin housing 224 and first pin 226 in the bore 222 of the column 202 so that the first and second pins and housings, 224 , 226 , 242 , 244 respectively do not inhibit the rotational movement of the cylinder 208 about the barrel 204 . According to one such embodiment, biasing means 122 and the first pin 224 , second pin 242 , first pin housing 226 , and/or second pin housing 244 may be construction of magnets or be imparted with polarities that, when properly mated, allow the first pin 226 , second pin 244 , first pin housing 224 , and second pin housing 242 be positioned in the lock assembly 200 so as to not inhibit the rotational movement of the cylinder 208 .
In one embodiment, the invention provides a key assembly 100 positioned in a lock assembly 200 , the key assembly 100 , comprising: a key blade 112 , the key blade having a first surface 106 and a second surface 108 , the key blade 112 configured to be inserted into the lock 200 ; an aperture 109 in the key blade 112 , the aperture 109 having an axis; a cap 120 having an outer surface 123 , captured in the aperture 109 for continuous axial travel between a first limit extending out of the first surface 106 and a second limit recessed within the aperture 109 ; and a base 124 having an outer surface 131 captured in the aperture 109 for continuous axial travel between a first limit extending out of the second surface 108 and a second limit recessed within the aperture 109 ; wherein the base 124 is biased away from the cap 120 ; the lock assembly 200 having a barrel 204 , a column 202 extending from the barrel 204 , and a cylinder 208 configured to rotate within the barrel 204 , the cylinder 208 including a guide way 210 ; the column 202 having an bore 222 configured to receive the sliding movement of a first pin housing 224 , the first pin housing 224 configured to receive the sliding movement of a first pin 226 ; the cylinder 208 including a cylinder aperture 206 configured to receive the sliding movement of a second pin housing 242 , the second pin housing 242 configured to receive the sliding movement of a second pin 244 , the first pin 226 being inwardly biased against the second pin 244 so as to place the first pin 226 in the cylinder aperture 206 when the key assembly 100 is not positioned in the lock assembly 200 ; the key assembly 100 configured to outwardly bias and move the cap 120 or the base 124 against the first pin 226 when the key assembly 100 is positioned in the lock assembly 200 so that the second pin 244 and the second pin housing 242 are located inside the cylinder 208 and the first pin 226 and first pin housing 224 are located outside of the cylinder 208 .
FIG. 7 illustrates a cross sectional view of a section of the lock assembly 200 in which the key assembly 100 has been inserted into the lock assembly 200 according to an embodiment of the present invention. In this embodiment, the lock guide way 210 includes a depression 250 in which the base 124 a is inserted when the key assembly 100 is positioned in the lock assembly 200 . The addition of the depression 250 and the limit the cap 120 a may be separated from the base 124 a by the tabs 127 and lip 129 may reduce the distance that the floating element 104 moves the first and second pins 226 , 244 and first and second housings 226 , 244 . For example, when activated, the base 124 a may be located in the depression 250 , and therefore be lower in the cylinder 208 than where the base 124 a is located in the embodiment illustrated in FIG. 6 . Thus, by lowering the base 124 , the cap 120 a may not extend from surface 106 the key blade 112 in the embodiment in FIG. 7 than the embodiment shown in FIG. 6 a . A longer second pin 244 and/or second pin housing 242 may therefore be required in the embodiment shown in FIG. 7 so that the engagement of the second housing and pin 242 , 244 and first housing and pin 224 , 226 occurs along the diameter of the cylinder 208 so as to allow for the cylinder 208 to be rotated, and thereby operate the lock assembly 200 .
FIG. 8 illustrates a cross sectional view of a section of the lock assembly 200 having a lower pin assembly 300 in which the key assembly 100 has been inserted into the lock assembly 200 according to an embodiment of the present invention. The lower pin 302 moves through an opening 306 in the cylinder 208 and is under the force of a spring 308 . The lower pin assembly 300 includes a lower pin 302 and bottom cylinder 304 . As show in FIG. 8 , the base 124 a may have a contoured surface complementary to the tip 309 of the lower pin 302 . Moreover, these mating surfaces of the tip 309 and base 124 a allow the lower pin 302 to be properly position so that when activated, the lower pin assembly 300 does not extend beyond the outer diameter of the cylinder 208 . However, if the tip 309 is improperly configured for the contour of the base 124 , the tip may not properly mate the contour of the base 124 , but instead may abut against the bottom of the base 124 . Such an arrangement may prohibit the lock from operating, as the lower pin assembly 300 may extend beyond the diameter of the cylinder 208 , and thereby interfere with the rotation of the cylinder 208 .
When the tip 309 does properly mate with the contour of the base 124 a , the lower pin assembly 300 may extend into the barrel 204 or the plug 310 of the lower actuating element 309 may be forced by a spring 308 into the cylinder 208 , both of which may inhibit rotational movement of the cylinder 208 .
FIG. 9 a illustrates a cross sectional view of a section of the lock assembly 200 having a lower pin assembly 300 in which the key assembly 100 has been inserted into the lock assembly according to an embodiment of the present invention. In the embodiment illustrated in FIG. 9 a , the base 124 a includes an actuator pin 126 a , a portion of which may slide outwardly through an aperture in the outer surface 131 of base 124 a beyond the base 124 a . For example, the base 124 a may include an orifice through which at least a portion of the actuator pin 126 a may travel. The actuator pin 126 a includes a distal end 128 , a proximal end 130 , and at least one shoulder 132 . The distal end 128 engages the tip 309 of the lower pin 302 . According to one embodiment, the biasing means 122 a , such as a spring in one embodiment imparts a downward force against the shoulder 128 to direct the actuator pin 126 a downwardly against the lower pin 302 . Further, the shoulder 128 may limit the distance the actuator pin 126 a may travel out of the base 124 a and/or retain the actuator pin 126 a in the base 124 a thereby again, increasing the number of possible key/lock combination and adding to the security of the entry way. Due to the precision required in the depth that the bottom cylinder 304 and plug 310 must move to reach the proper position so as to not prohibit the cylinder 208 from moving, the configuration of the actuator pin 126 a may add further complexity to the ability to the unauthorized successful duplication of the key assembly 100 .
FIG. 9 b illustrates a cross sectional view of a section of the key assembly 100 having an actuator pin 126 b extending from the cap 120 a of the floating element 104 a according to an embodiment of the present invention. The actuator pin 126 b shown in FIG. 9 b is similar to the actuator pin 126 a shown in FIG. 9 a , except, rather than extending from the base 124 a and exerting a force against the lower pin assembly 300 , the actuator pin 126 b in FIG. 9 b extends from the cap 120 and exerts a force against the second pin 244 . Additionally, the embodiment illustrated in FIG. 9 b includes the feature of a depression 250 , as previously discussed with reference to FIG. 7 .
FIG. 10 illustrates a cross sectional view of a key assembly 100 and a lock assembly 200 in which the floating elements 104 a , 104 b include a protruding ball 260 a , 260 b according to an embodiment of the present invention. The partially protruding ball 260 a , 260 b may be retained in the floating elements 104 a , 104 b by a variety of different ways, including, for example, having in the cover 120 a , 120 b an opening smaller than the outer diameter of the partially protruding ball 260 a , 260 b . Biasing means 122 a , 122 b such as elastic materials in certain embodiments may force at least a portion of the protruding ball 260 a , 260 b to extend outwardly from the cap 120 , the base 124 as shown in FIG. 3 b and FIG. 14 , or both in floating elements 104 a , 104 b . For example, in the embodiment illustrated in FIG. 10 , the biasing mean 122 a may force at portion of the protruding ball 260 a to extend beyond the cover 120 a so that the partially protruding ball 260 a engages and moves the second pin 244 outwardly while the cover 120 a engages and moves the second housing 242 outwardly. The distance the protruding ball 260 a extends from the cover 120 a is configured so that the second pin 244 moves the distance required to move the first pin 226 out of the aperture 240 of the cylinder 208 and into the bore 222 of the column 202 while retaining the second pin 244 in the aperture 240 of the cylinder 208 . Additionally, because the partially protruding ball 260 a extends from the cover 120 a , the second pin 244 may have a different length than that of the second pin housing 242 , further complicating the unauthorized duplication of the key assembly 100 .
FIG. 11 illustrates a cross sectional view of a key assembly 100 and lock assembly 200 in which the partially protruding balls 260 a , 260 b extend from the base 124 a , 124 b of floating elements 104 a , 104 b and the lock assembly 200 includes a lower lock actuating assembly 300 according to an embodiment of the present invention. Similar to the embodiment illustrated in FIG. 10 , the floating elements 104 a , 104 b may be configured to control the extent the protruding balls 260 a , 260 b may be outwardly biased when floating elements 104 a , 104 b are actuated, such as, for example, controlling the size of the aperture opening in the lower surface 131 a , 131 b of base 124 a , 124 b respectively, through which the balls 260 a , 260 b partially protrude.
In the embodiment illustrated in FIG. 11 , when the floating element 104 a is actuated in at the proper location along the axis of the key blade 112 aperture 109 when inserted in the lock assembly 200 , the protruding ball 260 a engages a lower pin 400 . The lower pin 400 may slidingly move inside a lower housing 402 . The lower housing 402 may slide in a lower bore 404 of the cylinder 208 . The lower pin 400 may include a plunger 401 that engages a lower protruding ball 336 of a lock floating assembly 300 . In addition to the lower protruding ball 336 , the lock floating assembly 300 may include a cover 333 , an actuator 334 and a base 335 . The cover 333 and base 335 of the lock assembly 300 may be retained together in a manner similar to that described above with respect to the cover 120 a and base 124 a of the floating element 104 a of the key assembly 100 , such as, for example, the cover 333 having a lower protrusion 336 with taps 337 that engage the lips 338 of the base 335 . In use, when the lock biasing mechanism 300 inwardly extends into lower bore 404 of the cylinder or the lower pin 400 or lower pin housing 402 extends into the opening 210 in the barrel, an interference is created that inhibits the rotational movement of the cylinder 208 . When the proper forces are exerted on the lower pin 400 , lower pin housing 402 , and lock floating assembly 300 , and the protruding balls 260 a , 336 base 124 a , and cover 333 extend the proper distance, neither the lower pin 400 and lower pin housing 402 do not extend into the opening 210 nor does assembly 300 extend in the cylinder 208 so to not inhibit rotational movement of the cylinder 208 .
In one embodiment, provided herein in combination; a key assembly 100 comprising: a key blade 112 , the key blade having a first surface 106 and a second surface 108 , the key blade 112 configured to be inserted into a mating lock; an aperture 109 in the key blade, the aperture having an axis; a cap 120 having an outer surface 123 , captured in the aperture 109 for continuous axial travel between a first limit extending out of the first surface 106 and a second limit recessed within the aperture 109 ; and a base 124 having an outer surface 131 captured in the aperture 109 for continuous axial travel between a first limit extending out of the second surface 108 and a second limit recessed within the aperture 109 ; wherein the base 124 is biased away from the cap; and a mating lock assembly 200 , the lock assembly having a barrel 204 , a column 202 extending from the barrel 204 , and a cylinder 208 configured to rotate within the barrel 204 , the cylinder 208 including a guide way 210 ; the column having an aperture configured to receive the sliding movement of a first pin housing 224 , the first pin housing configured to receive the sliding movement of a first pin 226 ; the cylinder 208 including a cylinder aperture 206 configured to receive the sliding movement of a second pin housing 242 , the second pin housing configured to receive the sliding movement of a second pin 244 , the first pin 226 being inwardly biased against the second pin 244 so as to place the first pin 226 in the cylinder aperture 206 when the key assembly 100 is not positioned in the lock assembly 200 ; the key configured to outwardly bias and move the cap 120 or the base 124 against the first pin 226 when the key assembly 100 is positioned in the lock assembly 200 so that the second pin 244 and the second pin housing 242 are located inside the cylinder 208 and the first pin 226 and first pin housing 224 are located outside of the cylinder 208 .
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims. | 4y
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RELATED APPLICATION
[0001] The present invention is related to and claims the benefit of U.S. provisional patent application Ser. No. 61/148,376, filed Jan. 29, 2009, the contents of which are incorporated by reference herein in their entirety.
TECHNICAL FIELD
[0002] The invention generally relates to methods of identifying and categorizing organisms and more specifically methods of generating and using patterns of chromosomal variation in order to classify organisms.
BACKGROUND
[0003] Rapid identification of microorganisms, such as bacteria, from clinical samples is important in clinical microbiology. Moreover, the proper classification and/or characterization of microorganisms can have a significant impact on proper diagnosis and treatment of disease.
[0004] Traditional methods for phylogenetic analysis of microorganisms at the DNA level involve creating restriction digests and using pulse-field electrophoresis to produce banding patterns that are useful in determining the relatedness of different microorganisms or different strains of a microorganism. Recently, optical mapping has enabled the generation of genomic restriction maps of many thousands of single DNA molecules. Each optical molecule map contains an ordered set of DNA fragments of distinct sizes. The order and sizes of the fragments within a given map represents a unique signature of the genome of the organism from which the DNA was obtained. optical mapping allows the collection of thousands of single molecule maps in parallel. optical mapping also has the benefit of allowing the identification of bacteria directly from clinical samples without the need for growth on primary culture medium.
[0005] The optical mapping technique has the benefit of conveying more information that standard electrophoresis, which only is able to separate fragments by size and charge. For example, optical mapping has the capability of differentiating characteristics of samples other than simply size. The present invention provides various novel uses for optical mapping in the identification and analysis of organisms.
SUMMARY
[0006] The present invention provides methods of identifying and classifying organisms. Methods of the invention utilize optical mapping in order to provide insight into genomic characteristics of a microorganism, resulting in rapid identification and classification.
[0007] In one embodiment, methods of the invention allow the determination of the genetic relatedness of two or more organisms based upon optical maps produced from restriction digests of their DNA. The invention is particularly useful for the identification and classification of microorganisms, particularly disease-causing microorganisms. For example, methods of the invention have been used to identify patterns of chromosomal markers in antibiotic-resistant bacteria that allow classification of the bacteria with respect to specific resistance characteristics. That type of classification is useful for determining the appropriate course of treatment for an individual infected with the bacterium from which the DNA was obtained.
[0008] Methods of the invention also allow one to determine a likely lineage for a particular genomic element in a microorganism under investigation. For example, methods of the invention are useful for identifying the source of the antibiotic resistance in an isolated microorganism. Moreover, optical mapping according to the invention allows the identification of common genetic elements or patterns in organisms, such as microorganisms, that are informative with respect to the choice of treatment options. In the area of antibiotic resistance, one can also determine whether resistance was acquired, for example, by transfer via a conjugative plasmid or some other event or series of events.
[0009] Methods of the invention allow the identification of genomic rearrangements, such as inversions, that would not be observable using traditional techniques, such as pulse-gel electrophoresis. The ability to identify genomic changes at a level of granularity not before achieved opens up many new research and clinical applications, including establishing phylogenetic relationships, suggesting appropriate treatments, determining the etiology of disease, determining the way in which genomic elements (e.g., antibiotic resistance) are acquired and passed on, among others.
[0010] The invention contemplates, in one embodiment, creating patterns that are useful as markers of genomic characteristics of an organism. Pattern generation and comparison is a useful way to categorize microorganisms, such as bacteria, and to create catalogs of strains or types based upon relevant genetic characteristics. For example, bacteria can be classified on the basis of patterns generated by optical mapping with respect to their antibiotic resistance properties. Generating the patterns and then comparing unknown samples leads to rapid and accurate diagnosis followed by appropriate treatment. Using methods of the invention, one can determine whether a specific bacterium is vancomycin-resistance, methicillin-resistant and, if so, what subtype (e.g., hospital-acquired vs. community acquired).
[0011] In another embodiment, the invention contemplates obtaining DNA from an organism (e.g., a test organism), creating restriction fragments of the DNA and making an optical map based upon those fragments. The optical map is then compared to maps of restriction fragments of at least on other organism in order to categorize the test organism. By categorization, it is meant placing the organism in a category based upon patterns in the optical map. Categorization can be done by similarities or differences in one or more pattern(s) present in the optical map of the organism and those of organisms in a database or other organisms for which optical maps are created in concert with the test organism.
[0012] The invention allows the determination of the relatedness of organisms, such as microorganisms based upon the pattern of restriction fragments, or markers, on nucleic acid obtained from the organism(s). FIG. 9 , for example, shows the pattern of deletions, insertions, inversions and repeats in nine strains of vancomycin-resistant stapholoccus aureus (VRSA). The various triangles in the schematic indicate spots in which a deletion or insertion has occurred. These were determined to be characteristic of the particular strain that displayed resistance. These patterns allow one to determine that VRSA 1 and VRSA 5 are the same. More importantly, the patterns across all nine strains reveal that the vancomycin resistant trait did not originate from the same progenitor source. This conclusion has importance in tracing the source of an infection and in matching the treatment with the particular bacterium. It is important to note that it is immaterial for purposed of the invention exactly what the deletion or insertion is (i.e., what particular nucleotides were deleted or inserted). Rather, what is important is the pattern of insertions and/or deletions along the length of the chromosome. It is those patterns that allow one to compare strains, subtypes, etc. in order to make determinations about phylogeny, categorization, etiology, and the like.
[0013] Methods of the invention are based upon chromosomal DNA analysis using optical mapping, which produces high-resolution, ordered restriction maps of an organisms genome. Once prepare, as detailed below, maps are compared, for example, by using phylogenetic analysis techniques and viewers as described herein. Patterns produced using optical maps of the invention are useful to distinguish, categorize, and compare the organisms from which DNA was obtained.
[0014] In one aspect, an unknown sample is compared to a database of optical maps, or patterns generated therefrom, in order to allow identification, classification, comparison, etc. of organisms. Using a restriction map database, organisms are identified and classified not just at a genus and species level, but also at a sub-species (strain), a sub-strain, and/or an isolate level. The featured methods offer fast, accurate, and detailed information for identifying and classifying organisms. Methods of the invention can be used in a clinical setting, e.g., a human or veterinary setting; or in an environmental or industrial setting (e.g., clinical or industrial microbiology, food safety testing, ground water testing, air testing, contamination testing, and the like). In essence, the invention is useful in any setting in which the detection and/or identification of a microorganism is necessary or desirable.
[0015] This invention also features methods of diagnosing a disease or disorder in a subject by, inter alia, identifying at least one organism by correlating the restriction map of a nucleic acid from each organism with a restriction map database and correlating the identity of each organism with the disease or disorder. Methods of the invention further contemplate using the diagnosis to prescribe appropriate treatment.
[0016] The DNA from any organism can be used in methods of the invention. Common organism include a microorganism, a bacterium, a protist, a virus, a fungus, or disease-causing organisms including microorganisms such as protozoa and multicellular parasites. The nucleic acid can be deoxyribonucleic acid (DNA), a ribonucleic acid (RNA) or can be a cDNA copy of an RNA obtained from a sample. The nucleic acid sample includes any tissue or body fluid sample, environmental sample (e.g., water, air, dirt, rock, etc.), and all samples prepared therefrom.
[0017] Methods of the invention can further include digesting nucleic acid with one or more enzymes, e.g., restriction endonucleases, e.g., BglII, NcoI, XbaI, and BamHI, prior to imaging. Preferred restriction enzymes include, but are not limited to:
[0000]
AflII
ApaLI
BglII
AflII
BglII
NcoI
ApaLI
BglII
NdeI
AflII
BglII
MluI
AflII
BglII
PacI
AflII
MluI
NdeI
BglII
NcoI
NdeI
AflII
ApaLI
MluI
ApaLI
BglII
NcoI
AflII
ApaLI
BamHI
BglII
EcoRI
NcoI
BglII
NdeI
PacI
BglII
Bsu36I
NcoI
ApaLI
BglII
XbaI
ApaLI
MluI
NdeI
ApaLI
BamHI
NdeI
BglII
NcoI
XbaI
BglII
MluI
NcoI
BglII
NcoI
PacI
MluI
NcoI
NdeI
BamHI
NcoI
NdeI
BglII
PacI
XbaI
MluI
NdeI
PacI
Bsu36I
MluI
NcoI
ApaLI
BglII
NheI
BamHI
NdeI
PacI
BamHI
Bsu36I
NcoI
BglII
NcoI
PvuII
BglII
NcoI
NheI
BglII
NheI
PacI
[0018] Imaging ideally includes labeling the nucleic acid. Labeling methods are known in the art and can include any known label. However, preferred labels are optically-detectable labels, such as 4-acetamido-4′-isothiocyanatostilbene-2,2′disulfonic acid; acridine and derivatives: acridine, acridine isothiocyanate; 5-(2′-aminoethyl)aminonaphthalene-1-sulfonic acid (EDANS); 4-amino-N-[3-vinylsulfonyl)phenyl]naphthalimide-3,5 disulfonate; N-(4-anilino-1-naphthyl)maleimide; anthranilamide; BODIPY; Brilliant Yellow; coumarin and derivatives; coumarin, 7-amino-4-methylcoumarin (AMC, Coumarin 120), 7-amino-4-trifluoromethylcouluarin (Coumaran 151); cyanine dyes; cyanosine; 4′,6-diaminidino-2-phenylindole (DAPI); 5′5″-dibromopyrogallol-sulfonaphthalein (Bromopyrogallol Red); 7-diethylamino-3-(4′-isothiocyanatophenyl)-4-methylcoumarin; diethylenetriamine pentaacetate; 4,4′-diisothiocyanatodihydro-stilbene-2,2′-disulfonic acid; 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid; 5-[dimethylamino]naphthalene-1-sulfonyl chloride (DNS, dansylchloride); 4-dimethylaminophenylazophenyl-4′-isothiocyanate (DABITC); eosin and derivatives; eosin, eosin isothiocyanate, erythrosin and derivatives; erythrosin B, erythrosin, isothiocyanate; ethidium; fluorescein and derivatives; 5-carboxyfluorescein (FAM), 5-(4,6-dichlorotriazin-2-yl)aminofluorescein (DTAF), 2′,7′-dimethoxy-4′5′-dichloro-6-carboxyfluorescein, fluorescein, fluorescein isothiocyanate, QFITC, (XRITC); fluorescamine; IR144; IR1446; Malachite Green isothiocyanate; 4-methylumbelliferoneortho cresolphthalein; nitrotyrosine; pararosaniline; Phenol Red; B-phycoerythrin; o-phthaldialdehyde; pyrene and derivatives: pyrene, pyrene butyrate, succinimidyl 1-pyrene; butyrate quantum dots; Reactive Red 4 (Cibacron® Brilliant Red 3B-A) rhodamine and derivatives: 6-carboxy-X-rhodamine (ROX), 6-carboxyrhodamine (R6G), lissamine rhodamine B sulfonyl chloride rhodamine (Rhod), rhodamine B, rhodamine 123, rhodamine X isothiocyanate, sulforhodamine B, sulforhodamine 101, sulfonyl chloride derivative of sulforhodamine 101 (Texas Red); N,N,N′,N′ tetramethyl-6-carboxyrhodamine (TAMRA); tetramethyl rhodamine; tetramethyl rhodamine isothiocyanate (TRITC); riboflavin; rosolic acid; terbium chelate derivatives; Cy3; Cy5; Cy5.5; Cy7; IRD 700; IRD 800; La Jolta Blue; phthalo cyanine; naphthalo cyanine, BOBO, POPO, YOYO, TOTO and JOJO.
[0019] A database for use in the invention can include a restriction map similarity cluster. The database can include a restriction map from at least one member of the clade of the organism. The database can include a restriction map from at least one subspecies of the organism. The database can include a restriction map from a genus, a species, a strain, a sub-strain, or an isolate of the organism. The database can include a restriction map with motifs common to a genus, a species, a strain, a sub-strain, or an isolate of the organism.
[0020] In another aspect, the invention features a method of diagnosing a disease or disorder in a subject, including obtaining a sample suspected to contain at least one organism to be detected; (b) imaging a nucleic acid from each organism; (c) obtaining a restriction map of each nucleic acid; (d) identifying each organism by correlating the restriction map of each nucleic acid with a restriction map database; and (e) correlating the identity of each organism with the disease or disorder or with other organisms in the database.
[0021] Methods can further include treating a disease or disorder in a subject, including diagnosing a disease or disorder in the subject as described above and providing treatment to the subject to ameliorate the disease or disorder. Treatment can include administering a drug to the subject.
[0022] In one embodiment, a restriction map obtained from a single DNA molecule is compared against a database of restriction maps from known organisms in order to identify the closest match to a restriction fragment pattern occurring in the database. This process can be repeated iteratively until sufficient matches are obtained to identify an organism at a predetermined confidence level. According to methods of the invention, nucleic acid from a sample are prepared and imaged as described herein. A restriction map is prepared and the restriction pattern is correlated with a database of restriction patterns for known organisms. In a preferred embodiment, organisms are identified from a sample containing a mixture of organisms. Use of methods of the invention allows the detection of multiple microorganisms from the same sample, either serially or simultaneously.
[0023] In use, the invention can be applied to identify or classify a microorganism making up a contaminant in an environmental sample. For example, methods of the invention are useful to identify a potential biological hazard in a sample of air, water, soil, clothing, luggage, saliva, urine, blood, sputum, food, drink, and others. In a preferred embodiment, methods of the invention are used to detect and identify an organism in a sample obtained from an unknown source. In essence, methods of the invention can be used to detect biohazards in any environmental or industrial setting.
[0024] Further aspects and features of the invention will be apparent upon inspection of the following detailed description thereof.
[0025] All patents, patent applications, and references cited herein are incorporated in their entireties by reference.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a diagram showing restriction maps of six isolates of E. coli.
[0027] FIG. 2 is a diagram showing restriction maps of six isolates of E. coli clustered into three groups: O157 (that includes O157:H7 and 536), CFT (that includes CFT073 and 1381), and K12 (that includes K12 and 718).
[0028] FIG. 3 is a diagram showing common motifs among restriction maps of six isolates of E. coli.
[0029] FIG. 4 is a diagram showing restriction maps of six isolates of E. coli , with the boxes indicating regions common to E. coli.
[0030] FIG. 5 is a diagram showing restriction maps of six isolates of E. coli , with the boxes indicating regions that are unique to a particular strain, namely O157, CFT, or K12.
[0031] FIG. 6 is a diagram showing restriction maps of six isolates of E. coli , with the boxes indicating regions unique to each isolate.
[0032] FIG. 7 is a tree diagram, showing possible levels of identifying E. coli.
[0033] FIG. 8 is a diagram showing restriction maps of a sample (middle map) and related restriction maps from a database.
[0034] FIG. 9 is a schematic diagram showing patterns of markers in various vancomycin-resistant bacterial strains in which dark triangles represent deletions, lighter triangles represent insertions, semicircular arrows are inversions, and double arrows are tandem repeats.
[0035] FIG. 10 is a comparison of a methicillin-resistant bacterium and three different strains of vancomycin-resistant bacteria, showing restriction fragment patterns from optical maps according to the invention.
[0036] FIG. 11 shows pattern matching between two methicillin-resistant bacteria and a vancomycin-resistant bacterium from optical maps prepared according to the invention.
[0037] FIG. 12 is a schematic diagram showing patterns of markers in various methicillin-resistant Staphylococcus aureaus strains.
DETAILED DESCRIPTION
[0038] The present invention provides methods of identifying and/or classifying mircoorganisms. Preferred methods include obtaining a restriction map of a nucleic acid, e.g., DNA, from each organism and correlating the restriction map of each nucleic acid with a restriction map database, thereby identifying and/or comparing organisms obtained from a sample. With use of a detailed restriction map database that contains motifs common to various groups and sub-groups, organisms can be identified and classified not just at a genus and species level, but also at a sub-species (strain), a sub-strain, and/or an isolate level. For example, bacteria can be identified and classified at a genus level, e.g., Escherichia genus, species level, e.g., E. coli species, a strain level, e.g., O157, CFT, and K12 strains of E. coli , and isolates, e.g., O157:H7 isolate of E. coli (as described in Experiment 3B below). The featured methods offer a fast, accurate, and detailed information for identifying organisms. These methods can be used in a variety of clinical settings, e.g., for identification of an organism in a subject, e.g., a human or an animal subject.
[0039] This disclosure also features methods of diagnosing a disease or disorder in a subject by, inter alia, identifying each organism in a sample, including a heterogeneous sample, via correlating the restriction map of a nucleic acid from each organism with a restriction map database, and correlating the identity of each organism in the sample with the disease or disorder. These methods can be used in a clinical setting, e.g., human or veterinary setting.
[0040] Methods of the invention are also useful for identifying and/or detecting organisms in food or in an environmental setting. For example, methods of the invention can be used to assess an environmental threat in drinking water, air, soil, and other environmental sources. Methods of the invention are also useful to identify organisms in food and to determine a common source of food poisoning in multiple samples that are separated in time or geographically, as well as samples that are from the same or similar batches.
[0041] In a particularly-preferred embodiment, methods of the invention comprise identifying restriction patterns based upon optical mapping and using those patterns to determine characteristics of the organism being analyzed. For example, a microorganism is compared to a database of known patterns in order to determine properties that allow identification of the organism, characteristics of the organism, classification of the organism, and other features that aid in, for example, disease diagnosis and treatment.
Restriction Mapping
[0042] Methods featured herein utilize restriction mapping during both generation of the database and processing of an organism to be identified. One type of restriction mapping that is used is optical mapping. Optical mapping is a echnique for production of ordered restriction maps from a single DNA molecule (Samad et al., Genome Res. 5:1-4, 1995). During this method, fluorescently labeled DNA molecules are elongated in a flow of agarose between a coverslip and a microscope slide (in the first-generation method) or fixed onto polylysine-treated glass surfaces (in a second-generation method). Id. The added endonuclease cuts the DNA at specific points, and the fragments are imaged. Id. Restriction maps can be constructed based on the number of fragments resulting from the digest. Id. Generally, the final map is an average of fragment sizes derived from similar molecules. Id. Thus, in one embodiment of the present methods, the restriction map of an organism to be identified is an average of a number of maps generated from the sample containing the organism.
[0043] Optical mapping and related methods are described in U.S. Pat. No. 5,405,519, U.S. Pat. No. 5,599,664, U.S. Pat. No. 6,150,089, U.S. Pat. No. 6,147,198, U.S. Pat. No. 5,720,928, U.S. Pat. No. 6,174,671, U.S. Pat. No. 6,294,136, U.S. Pat. No. 6,340,567, U.S. Pat. No. 6,448,012, U.S. Pat. No. 6,509,158, U.S. Pat. No. 6,610,256, and U.S. Pat. No. 6,713,263, each of which is incorporated by reference herein. Optical Maps are constructed as described in Reslewic et al., Appl Environ Microbiol. 2005 September; 71 (9):5511-22, incorporated by reference herein. Briefly, individual chromosomal fragments from test organisms are immobilized on derivatized glass by virtue of electrostatic interactions between the negatively-charged DNA and the positively-charged surface, digested with one or more restriction endonuclease, stained with an intercalating dye such as YOYO-1 (Invitrogen) and positioned onto an automated fluorescent microscope for image analysis. Since the chromosomal fragments are immobilized, the restriction fragments produced by digestion with the restriction endonuclease remain attached to the glass and can be visualized by fluorescence microscopy, after staining with the intercalating dye. The size of each restriction fragment in a chromosomal DNA molecule is measured using image analysis software and identical restriction fragment patterns in different molecules are used to assemble ordered restriction maps covering the entire chromosome.
Restriction Map Database
[0044] The database(s) used with methods described herein are generated by optical mapping techniques discussed supra. The database(s) can contain information for a large number of isolates, e.g., about 200, about 300, about 400, about 500, about 600, about 700, about 800, about 900, about 1,000, about 1,500, about 2,000, about 3,000, about 5,000, about 10,000 or more isolates. In addition, the restriction maps of the database contain annotated information (a similarity cluster) regarding motifs common to genus, species, sub-species (strain), sub-strain, and/or isolates for various organisms. The large number of the isolates and the information regarding specific motifs allows for accurate and rapid identification of an organism.
[0045] The restriction maps of the database(s) can be generated by digesting (cutting) nucleic acids from various isolates with specific restriction endonuclease enzymes. Some maps can be a result of digestion with one endonuclease. Some maps can be a result of a digest with a combination of endonucleases, e.g., two, three, four, five, six, seven, eight, nine, ten or more endonucleases. The exemplary endonucleases that can be used to generate restriction maps for the database(s) and/or the organism to be identified include: BglII, NcoI, XbaI, and BamHI. Non-exhaustive examples of other endonucleases that can be used include: Alul, ClaI, DpnI, EcoRI, HindIII, KpnI, PstI, SacI, and SmaI. Yet other restriction endonucleases are known in the art.
[0046] Map alignments between different strains are generated with a dynamic programming algorithm which finds the optimal alignment of two restriction maps according to a scoring model that incorporates fragment sizing errors, false and missing cuts, and missing small fragments (See Myers et al., Bull Math Biol 54:599-618 (1992); Tang et al., J Appl Probab 38:335-356 (2001); and Waterman et al., Nucleic Acids Res 12:237-242). For a given alignment, the score is proportional to the log of the length of the alignment, penalized by the differences between the two maps, such that longer, better-matching alignments will have higher scores.
[0047] To generate similarity clusters, each map is aligned against every other map. From these alignments, a pair-wise alignment analysis is performed to determine “percent dissimilarity” between the members of the pair by taking the total length of the unmatched regions in both genomes divided by the total size of both genomes. These dissimilarity measurements are used as inputs into the agglomerative clustering method “Agnes” as implemented in the statistical package “R”. Briefly, this clustering method works by initially placing each entry in its own cluster, then iteratively joining the two nearest clusters, where the distance between two clusters is the smallest dissimilarity between a point in one cluster and a point in the other cluster.
Organisms to be Identified
[0048] Various organisms, e.g., viruses, and various microorganisms, e.g., bacteria, protists, and fungi, can be identified with the methods featured herein. In one embodiment, the organism's genetic information is stored in the form of DNA. The genetic information can also be stored as RNA.
[0049] The sample containing the organism to be identified can be a human sample, e.g., a tissue sample, e.g., epithelial (e.g., skin), connective (e.g., blood and bone), muscle, and nervous tissue, or a secretion sample, e.g., saliva, urine, tears, and feces sample. The sample can also be a non-human sample, e.g., a horse, camel, llama, cow, sheep, goat, pig, dog, cat, weasel, rodent, bird, reptile, and insect sample. The sample can also be from a plant, water source, food, air, soil, plants, or other environmental or industrial sources.
Identifying Organisms
[0050] The methods described herein, i.e., methods of identifying at least one organism, diagnosing a disease or disorder in a subject, determining antibiotic resistance of at least one organism, determining an antibiotic resistance profile of a bacterium, and determining a therapeutically effective antibiotic to administer to a subject, and treating a subject, include correlating the restriction map of a nucleic acid of each organism with a restriction map database. The methods involve comparing each of the raw single molecule maps from the unknown sample (or an average restriction map of the sample) against each of the entries in the database, and then combining match probabilities across different molecules to create an overall match probability.
[0051] In one embodiment of the methods, entire genome of the organism to be identified can be compared to the database. In another embodiment, several methods of extracting shared elements from the genome can be created to generate a reduced set of regions of the organism's genome that can still serve as a reference point for the matching algorithms.
[0052] As discussed above and in the Examples below, the restriction maps of the database can contain annotated information (a similarity cluster) regarding motifs common to genus, species, sub-species (strain), sub-strain, and/or isolates for various organisms. Such detailed information would allow identification of an organism at a sub-species level, which, in turn, would allow for a more accurate diagnosis and/or treatment of a subject carrying the organism.
[0053] In another embodiment, methods of the invention are used to identify genetic motifs that are indicative of an organism, strain, or condition. For example, methods of the invention are used to identify in an isolate at least one motif that confers antibiotic resistance. This allows appropriate choice of treatment without further cluster analysis.
Applications
[0054] Methods described herein are used in a variety of settings, e.g., to identify an organism in a human or a non-human subject, in food, in environmental sources (e.g., food, water, air), and in industrial settings. The featured methods also include methods of diagnosing a disease or disorder in a subject, e.g., a human or a non-human subject, and treating the subject based on the diagnosis. The method includes: obtaining a sample comprising an organism from the subject; imaging a nucleic acid from the organism; obtaining a restriction map of said nucleic acid; identifying the organism by correlating the restriction map of said nucleic acid with a restriction map database; and correlating the identity of the organism with the disease or disorder.
[0055] As discussed above, various organisms can be identified by the methods discussed herein and therefore various diseases and disorders can be diagnosed by the present methods. The organism can be, e.g., a cause, a contributor, and/or a symptom of the disease or disorder. In one embodiment, more than one organism can be identified by the methods described herein, and a combination of the organisms present can lead to diagnosis. Skilled practitioners would be able to correlate the identity of an organism with a disease or disorder. For example, the following is a non-exhaustive list of some diseases and bacteria known to cause them: tetanus— Clostridium tetani ; tuberculosis— Mycobacterium tuberculosis ; meningitis— Neisseria meningitidis ; botulism— Clostridium botulinum ; bacterial dysentry— Shigella dysenteriae ; lyme disease— Borrelia burgdorferi ; gasteroenteritis— E. coli and/or Campylobacter spp.; food poisoning— Clostridium perfringens, Bacillus cereus, Salmonella enteriditis , and/or Staphylococcus aureus . These and other diseases and disorders can be diagnosed by the methods described herein.
[0056] Once a disease or disorder is diagnosed, a decision about treating the subject can be made, e.g., by a medical provider or a veterinarian. Treating the subject can involve administering a drug or a combination of drugs to ameliorate the disease or disorder to which the identified organism is contributing or of which the identified organism is a cause. Amelioration of the disease or disorder can include reduction in the symptoms of the disease or disorder. The drug administered to the subject can include any chemical substance that affects the processes of the mind or body, e.g., an antibody and/or a small molecule, The drug can be administered in the form of a composition, e.g., a composition comprising the drug and a pharmaceutically acceptable carrier. The composition can be in a form suitable for, e.g., intravenous, oral, topical, intramuscular, intradermal, subcutaneous, and anal administration. Suitable pharmaceutical carriers include, e.g., sterile saline, physiological buffer solutions and the like. The pharmaceutical compositions may be additionally formulated to control the release of the active ingredients or prolong their presence in the patient's system. Numerous suitable drug delivery systems are known for this purpose and include, e.g., hydrogels, hydroxmethylcellulose, microcapsules, liposomes, microemulsions, microspheres, and the like. Treating the subject can also include chemotherapy and radiation therapy.
INCORPORATION BY REFERENCE
[0057] References and citations to other documents, such as patents, patent applications, patent publications, journals, books, papers, web contents, have been made throughout this disclosure. All such documents are hereby incorporated herein by reference in their entirety for all purposes.
Equivalents
[0058] The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting on the invention described herein. Scope of the invention is thus indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
EXAMPLES
Example 1
Microbial Identification Using Optical Mapping
[0059] Microbial identification (ID) generally has two phases. In the first, DNA from a number of organisms are mapped and compared against one another. From these comparisons, important phenotypes and taxonomy are linked with map features. In the second phase, single molecule restriction maps are compared against the database to find the best match.
[0060] Database Building and Annotation
[0061] Maps sufficient to represent a diversity of organisms, on the basis of which it will be possible to discriminate among various organisms, are generated. The greater the diversity in the organisms in the database, the more precise will be the ability to identify an unknown organism. Ideally, a database contains sequence maps of known organisms at the species and sub-species level for a sufficient variety of microorganisms so as to be useful in a medical or industrial context. However, the precise number of organisms that are mapped into any given database is determined at the convenience of the user based upon the desired use to which the database is to be put.
[0062] After sufficient number of microorganisms are mapped, a map similarity cluster is generated. First, trees of maps are generated. After the tree construction, various phenotypic and taxonomic data are overlaid, and regions of the maps that uniquely distinguish individual clades from the rest of the populations are identified. The goal is to find particular clades that correlate with phenotypes/taxonomies of interest, which will be driven in part through improvements to the clustering method.
[0063] Once the clusters and trees have been annotated, the annotation will be applied back down to the individual maps. Additionally, if needed, the database will be trimmed to include only key regions of discrimination, which may increase time performance.
[0064] Calling (Identifying) an Unknown
[0065] One embodiment of testing the unknowns involves comparing each of the raw single molecule maps from the unknown sample against each of the entries in the database, and then combining match probabilities across different molecules to create an overall match probability.
[0066] The discrimination among closely related organisms can be done by simply picking the most hits or the best match probability by comparing data obtained from the organism to data in the database. More precise comparisons can be done by having detailed annotations on each genome for what is a discriminating characteristic of that particular genome versus what is a common motif shared among several isolates of the same species. Thus, when match scores are aggregated, the level of categorization (rather than a single genome) will receive a probability. Therefore, extensive annotation of the genomes in terms of what is a defining characteristic and what is shared will be required.
[0067] In one embodiment of the method, entire genomes will be compared to all molecules. Because there will generally be much overlap of maps within a species, another embodiment can be used. In the second embodiment, several methods of extracting shared elements from the genome will be created to generate a reduced set of regions that can still serve as a reference point for the matching algorithms. The second embodiment will allow for streamlining the reference database to increase system performance.
Example 2
Using Multiple Enzymes for Microbial Identification
[0068] In one embodiment, the single molecule restriction maps from each of the enzymes will be compared against the database described in Example 1 independently, and a probable identification will be called from each enzyme independently. Then, the final match probabilities will be combined as independent experiments. This embodiment will provide some built-in redundancy and therefore accuracy for the process.
INTRODUCTION
[0069] In general, optical mapping can be used within a specific range of average fragment sizes, and for any given enzyme there is considerable variation in the average fragment size across different genomes. For these reasons, it typically will not be optimal to select a single enzyme for identification of clinically-relevant microbes. Instead, a small set of enzymes will be chosen to optimize the probability that for every organism of interest, there will be at least one enzyme in the database suitable for mapping.
[0070] Selection Criteria
[0071] A first step in the selection of enzymes was the identification of the bacteria of interest. These bacteria were classified into two groups: (a) the most common clinically interesting organisms and (b) other bacteria involved in human health. The chosen set of enzymes must have at least one enzyme that cuts each of the common clinically interesting bacteria within the range of average fragment sizes suitable for detailed comparisons of closely related genomes (about 6-13 kb). Additionally, for the remaining organisms, each fragment must be within the functional range for optical mapping (about 4-20 kb). These limits were determined through mathematical modeling, directed experiments, and experience with customer orders. Finally, enzymes that have already been used for Optical Mapping were selected.
[0072] Suggested Set
[0073] Based upon the above criteria, the preliminary set consisted of the enzymes BglII, NcoI, and XbaI, which have been used for optical mapping. There are 28 additional sets that cover the key organisms with known enzymes, so in the event that this set is not adequate, there alternatives will be utilized (data not shown).
[0074] Final Steps
[0075] Because the analysis in Experiment 2 is focused on the sequenced genomes, prior to full database production, this set of enzymes will be tested against other clinically important genomes, which will be part of the first phase of the proof of principle study.
Example 3
Identification of E. coli
[0076] A. In one embodiment of a microbial identification method, nucleic acids of between about 500 and about 1,000 isolates will be optically mapped. Then, unique motifs will be identified across genus, species, strains, substrains, and isolates. To identify a sample, single nucleic acid molecules of the sample will be aligned against the motifs, and p-values assigned for each motif match. The p-values will be combined to find likelihood of motifs. The most specific motif will give the identification.
[0077] B. The following embodiment illustrates a method of identifying E. coli down to an isolate level. Restriction maps of six E. coli isolates were obtained by digesting nucleic acids of these isolates with BamHI restriction enzyme. FIG. 1 shows restriction maps of these six E. coli isolates: 536, O157:H7 (complete genome), CFT073 (complete genome), 1381, K12 (complete genome), and 718. As shown in FIG. 2 , the isolates clustered into three sub-groups (strains): O157 (that includes O157:H7 and 536), CFT (that includes CFT073 and 1381), and K12 (that includes K12 and 718).
[0078] These restriction maps provided multi-level information regarding relation of these six isolates, e.g., showed motifs that are common to all of the three sub-groups (see, FIG. 3 ) and regions specific to E. coli (see, boxed areas in FIG. 4 ). The maps were also able to show regions unique to each strain (see, boxed areas in FIG. 5 ) and regions specific to each isolate (see boxed regions in FIG. 6 ).
[0079] This and similar information can be stored in a database and used to identify bacteria of interest. For example, a restriction map of an organism to be identified can be obtained by digesting the nucleic acid of the organism with BamHI. This restriction map can be compared with the maps in the database. If the map of the organism to be identified contains motifs specific to E. coli , to one of the sub-groups, to one of the strains, and/or to a specific isolate, the identity of the organism can be obtained by correlating the specific motifs. FIG. 6 shows a diagram to illustrate the possibilities of traversing variable lengths of a similarity tree.
[0080] C. The following example illustrates identifying a sample as an E. coli bacterium. A sample (sample 28) was digested with BamHI and its restriction map obtained (see FIG. 8 , middle restriction map). This sample was aligned against a database that contained various E. coli isolates. The sample was found to be similar to four E. coli isolates: NC 002695, AC 000091, NC 000913, and NC 002655. The sample was therefore identified as E. coli bacterium that is most closely related to the AC 000091 isolate.
Example 4
Identification of Bacteria from Clinical Samples
[0081] Rapid identification of bacteria is an important goal in clinical microbiology labs. Current testing procedures most often require pure culture, which significantly lengthens the time required for identification. In contrast, single molecule maps generated by Optical Mapping can theoretically provide more rapid identification, even when multiple organisms are present.
[0082] The example herein assessed the ability of Optical Mapping to identify unknown bacteria directly from clinical samples.
Methods
[0083] Clinical samples were provided by Gundersen Lutheran Medical Foundation. The five samples for each of five clinical sample types (clinical colony, spiked blood bottles, spiked urine samples, clinical blood bottles, and clinical urine samples) were prepared and the identities blinded. Urine and blood culture bottle samples were processed by OpGen for isolation of bacterial cells. High molecular weight DNA for the samples were prepared directly from isolated bacterial cells using a modified Pulse-Field Gel Electrophoresis method as described in Birren et al. (Pulsed Field Gel Electrophoresis; A Practical Guide. San Diego: Academic Press, Inc. p. 25-74, 1993). Optical Chips for all DNA samples were prepared according to Reslewic et al. Microbial identification was performed by comparing collections of single molecule maps from each DNA sample to the identification database to determine the number of matches by using the algorithms described herein.
[0084] Results
[0085] DNA isolated from unknown samples from each of five sample type groups (clinical colony, spiked blood bottle, spiked urine sample, clinical blood bottle, and clinical urine sample) was analyzed by Optical Mapping using the restriction enzyme(s) specified. Collections of single molecule maps for each blinded clinical sample were analyzed using the algorithms described herein. Match data were generated using a p-value maximum set to 0.001. The number of single molecule maps that matched the top reported bacterial species as well as the next reported bacterial species from the ID are listed in Table 1 below. The final bacterial species identifications by Optical Mapping for each unknown sample along with the identifications made by Gundersen Luthern Medical Foundation microbiology laboratory are also represented.
[0000]
TABLE 1
Clinical identification data
Matches
to Top
Matches to
Unknown
Top Reported
Reported
Next Reported
ID by Optical
Sample Type Group
Sample
Enzyme(s)
Species
Species
Species
Mapping
ID by GLMF
Results
Clinical Colony
UTI 1
NcoI/Bg/II/XBaI
None
—
—
Not in DB
S. marcescens
Not in DB
Clinical Colony
UTI 2
NcoI
E. coli
55
0
E. coli
E. coli
Correct
Clinical Colony
UTI 3
Bg/II
E. coli
51
1
E. coli
E. coli
Correct
Clinical Colony
UTI 4
NcoI
P. aenuginosa
17
0
P. aenuginosa
P. aenuginosa
Correct
Clinical Colony
UTI 5
Bg/II
K. pneumoniae
78
1
K. pneumoniae
K. pneumoniae
Correct
Spiked Blood Bottle
SB 1
NcoI
S. aureus
64
0
S. aureus
S. aureus
Correct
Spiked Blood Bottle
SB 2
NcoI
E. Faecium
86
1
E. Faecium
E. Faecium
Correct
Spiked Blood Bottle
SB 3
NcoI
S. pyogenes
38
1
S. pyogenes
S. pyogenes
Correct
Spiked Blood Bottle
SB 4
Bg/II
P. auruginosa
251
1
P. auruginosa
P. auruginosa
Correct
Spiked Blood Bottle
SB 5
NcoI
S. agalactiae
122
2
S. agalactiae
S. agalactiae
Correct
Spiked Urine Bottle
SU 1
NcoI
E. coli
186
2
E. coli
E. coli
Correct
Spiked Urine Bottle
SU 2
NcoI
P. mirabillis
53
1
P. mirabillis
P. mirabillis
Correct
Spiked Urine Bottle
SU 3
NcoI
S. saprophyticus
23
1
S. saprophyticus
S. saprophyticus
Correct
Spiked Urine Bottle
SU 4
Bg/II
K. pneumoniae
66
1
K. pneumoniae
K. pneumoniae
Correct
Spiked Urine Bottle
SU 5
Bg/II
P. auruginosa
71
1
P. auruginosa
P. auruginosa
Correct
Clin. Blood Bottle
CB A
NcoI
S. epidermidis
89
1
S. epidermidis
S. epidermidis
Correct
Clin. Blood Bottle
CB B
NcoI
S. agalactiae
19
0
S. agalactiae
S. agalactiae
Correct
Clin. Blood Bottle
CB 3
NcoI
E. coli
22
1
E. coli
E. coli
Correct
Clin. Blood Bottle
CB 4
NcoI
K. pneumoniae
15
2
K. pneumoniae
K. pneumoniae
Correct
Clin. Blood Bottle
CB 6
NcoI
E. coli
100
1
E. coli
E. coli
Correct
Clin. Urine Sample
CU 1
NcoI
S. aureus
200
1
S. aureus
S. aureus
Correct
Clin. Urine Sample
CU 2
NcoI
E. Faecalis
69
1
E. Faecalis
E. Faecalis
Correct
Clin. Urine Sample
CU 3
NcoI
E. coli
38
1
E. coli
E. coli
Correct
Clin. Urine Sample
CU 4
NcoI/Bg/II/XBaI
None
—
—
Not in DB
C. freundii
Not in DB
Clin. Urine Sample
CU 5
Bg/II
* K. pneumoniae
1
1
K. pneumoniae
K. pneumoniae
Correct
Comparison of the columns entitled “ID by Optical Mapping” and “ID by GLMF” show that Optical Mapping made the same identification as Gundersen Luthern Medical Foundation in all but two cases. The results column shows Optical Mapping called the correct bacterial species for the unknown samplein all but two cases. An * symbol represents an unknown sample where the Optical Mapping assembly was used instead of the microbial identification to make an identification.
[0086] Data herein showed that of the 23 clinical samples that contained a representative species in the identification database, 100% identified to the same species as was identified by classical microbiology techniques at the Gundersen Lutheran Medical Foundation laboratory (Table 3). Furthermore, UTI 1 and CU 4 were correctly identified as not being in the identification database (Table 3).
[0087] Thus data herein demonstrated the ability of Optical Mapping to provide identification of clinically relevant bacteria directly from clinical samples. In addition, the results provided strong evidence that Optical Mapping could be used to significantly reduce the time necessary to identify bacteria in a clinical laboratory.
Example 5
Identification of Bacteria from Heterogeneous Samples
[0088] An important goal of clinical microbiology laboratories is the rapid identification of bacteria from clinical samples. However, lengthy culturing steps to obtain enough of a pure culture to allow for identification will slow the time to a result. In contrast, Optical Mapping can potentially provide identifications directly from clinical samples that may contain more than a single organism thereby decreasing the time to a result.
[0089] The example herein assessed the ability of Optical Mapping to identify unknown bacteria in complex mixtures.
[0090] Methods
[0091] Bacterial mixes were provided by Gundersen Lutheran Medical Foundation. Bacterial species for the mixtures were normalized to 1×10 9 CFU/ml and mixed in combinations and amounts to yield eight groups with varying constituents and ratios as shown in Table 2. The eight bacterial mixtures (1-8) were prepared with two to four bacterial species to allow for a specific ratio of each bacterium as measured by colony forming units. The percentage of each bacterium within each group is listed in Table 2.
[0000]
TABLE 2
Mixed culture constituents and ratios
Group
Bacterial Species
Percent
1
Escherichia coli O157:h7 ATCC 35150
50
Pseudomonas aeruginosa ATCC 9027
50
2
Esherichia coli O157:h7 ATCC 35150
90
Pseudomonas aeruginosa ATCC 9027
10
3
Staphylococcus aureus ATCC 25923
50
Escherichia coli O157:h7 ATCC 35150
50
4
Staphylococcus aureus ATCC 25923
90
Escherichia coli O157:h7 ATCC 35150
10
5
Staphylococcus aureus ATCC 25923
33
Escherichia coli O157:h7 ATCC 35150
33
Pseudomonas aeruginosa ATCC 9027
33
6
Staphylococcus aureus ATCC 25923
60
Escherichia coli O157:h7 ATCC 35150
30
Pseudomonas aeruginosa ATCC 9027
10
7
Enterococcus faecalis ATCC 19433
25
Staphylococcus aureus ATCC 25923
25
Escherichia coli O157:h7 ATCC 35150
25
Pseudomonas aeruginosa ATCC 9027
25
8
Enterococcus faecalis ATCC 19433
50
Staphylococcus aureus ATCC 25923
20
Escherichia coli O157:h7 ATCC 35150
20
Pseudomonas aeruginosa ATCC 9027
10
[0092] High molecular weight DNA for the samples was prepared directly from isolated bacterial cells using a modified Pulse-Field Gel Electrophoresis method as described in Birren et al. Optical Chips for DNA samples were prepared according to Reslewic et al. Microbial identification was performed by comparing collections of single molecule maps from each DNA sample to the identification database to determine the number of matches by using the algorithms described herein.
[0093] Results
[0094] DNA isolated from eight unknown bacterial mixtures (A, B, C, D, E, F, G, and H) was analyzed by Optical Mapping using the enzyme(s) specified (NcoI, BglII). Collections of single molecule maps for each unknown mixture (Table 2) were analyzed using the algorithms described herein. The algorithms identified matches to the identification database (Table 3).
[0000]
TABLE 3
Microbial mixture identification data
Max
Matches to
Unknown
S. aureus
E. coli
E. faecalis
P. aeruginosa
Untested
OpGen 1 st
OpGen 2 nd
Mix
Enzyme
Matches
Matches
Matches
Matches
Species
Choice
Choice
A
NcoI
1330*
204*
1
0
3
4 +
3
Bg/II
1*
78*
0
1
2
B
NcoI
0
594*
0
0*
2
2 +
1
Bg/II
0
912*
0
32*
3
C
NcoI
376*
451*
0
0*
3
6 +
5
Bg/II
29*
924*
0
127*
3
D
NcoI
425*
656*
90*
0*
4
8
7 +
Bg/II
5*
198*
0*
49*
3
E
NcoI
536*
1115*
170*
0*
2
7
8 +
Bg/II
0*
280*
0*
80*
3
F
NcoI
301*
518*
0
0*
3
5 +
6
Bg/II
2*
245*
0
150*
3
G
NcoI
235*
923*
0
0
2
3 +
4
Bg/II
3*
413*
0
3
4
H
NcoI
0
285*
0
0*
2
1 +
2
Bg/II
0
647*
0
777*
2
The match data was generated using a p-value maximum set to 0.01. Data were from representative Optical Chips. The number of matches represented how many single molecule maps matched the database to a specific species.
A * marked set indicates a match to a test species at a level of 8-fold or higher above background (i.e. max hit to untested species).
The + indicates where a correct group identification was made.
[0095] Data indicated that the bacterial constituents of the complex mixtures were identified correctly in 8 of 8 groups. Furthermore, the percentage of contributing bacterial species was identified correctly for 6 of the 8 groups.
[0096] Thus data herein demonstrated the ability of Optical Mapping to provide identification of clinically relevant bacteria in complex mixtures. In addition, the results provided strong evidence that Optical Mapping could be used to significantly reduce the time necessary to identify bacteria in a clinical laboratory.
Example 6
Comparison of Patterns Between Bacterial Strains
[0097] Several vancomycin-resistant Staphylococcus aureus (VRSA) and methicillin-resistant Staphylococcus aureas (MRSA) strains were obtained. The DNA was isolated and restriction digests were performed as provided above. An optical map was constructed using the methods described above for each strain and particular markers, or fragments, characteristic of the strains were identified. FIGS. 10-12 show the results for several of these comparisons. In FIG. 10 , there clearly are unique restriction patterns (shown in pink) that differentiate the USA-100 MRSA and VRSA-8 strains. These patterns allow clear differentiation of those strains from each other. Referring to FIG. 11 , the strains shown in that Figure enable classification of the three VRSA strains based upon an Xbal digest as VRSA-positive, but as different strains. However, the pattern is distinct from the MRSA strain shown immediately above, enabling easy distinction from the three VRSA strains. Finally, FIG. 12 shows how patterning according to the invention allows the indentification of two MRSA strains (USA 100 and USA 300) as MRSA and the VRSA-2 strain as a distinct strain. Indeed this is the case, as the MRSA and VRSA strains have different antibiotic resistance profiles that are indicated by the different restriction digest patterns revealed by optical mapping.
[0098] The embodiments of the disclosure may be carried out in ways other than those set forth herein without departing from the spirit and scope of the disclosure. The embodiments are, therefore, to be considered to be illustrative and not restrictive. | 4y
|
This is a continuation of application Ser. No. 08/155,227, filed on Nov. 22, 1993, which was abandoned upon the filing hereof.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a refrigerant condenser comprised of a pair of headers connected by a plurality of tubes, through which tubes a refrigerant flows in a serpentine manner.
2. Description of the Related Art
In the past, as this type of refrigerant condenser, provision has been made of a multiflow (MF) type refrigerant condenser such as the one shown in FIG. 8. That is, a pair of headers 1 and 2 are connected by a plurality of tubes 3 comprised of flat tubes. In the headers 1 and 2 are arranged separators at predetermined positions so that the refrigerant will flow in a serpentine manner through the tubes 3 between the headers 1 and 2.
In this case, to raise the heat exchange rate, Japanese Unexamined Patent Publication (Kokai) No. 63-161393 discloses a construction in which the number of times the refrigerant changes direction of flow in the headers 1 and 2 (hereinafter referred to as number of "turns") is set to one or more, while Japanese Unexamined Patent Publication (Kokai) No. 63-34466 discloses a construction in which the number of tubes making up the refrigerant passageway is reduced so as to reduce the cross-sectional area of the refrigerant passage from the inlet to the outlet.
In a refrigerant condenser comprised of a refrigerant passage which is turned back and forth as in the above-mentioned related art, however, if the number of turns of the refrigerant passage is increased to set the condensation distance large, while it is possible to increase the flow rate of the refrigerant and raise the heat exchange rate, the pressure loss inside the tubes increases, whereby the refrigerant pressure falls and along with this the problem arises of a fall in the condensation temperature. Therefore, when the number of turns of the refrigerant passage is set excessively large, the temperature difference between the outside air and the refrigerant becomes smaller, which is a factor behind a reduced heat exchange performance.
On the other hand, if the number of turns of the refrigerant passage is reduced to set the condensation distance smaller, while it is possible to decrease the pressure loss in the tubes, the flow rate of the refrigerant ends up falling, the heat exchange rate in the tubes becomes smaller, and the performance falls, which creates another problem. In view of the above, there assumingly is a number of turns of the refrigerant passage which is optimal for each heat exchanger.
The above-mentioned related art, however, merely suggest that increasing the number of turns or decreasing the sectional area of the passage contributes to an improved heat exchange rate. They do not go so far as to specify the optimal condensation distance for a heat exchanger and therefore do not solve the basic problem of improving the heat exchange rate.
SUMMARY OF THE INVENTION
The present invention was made in consideration of the above circumstances and has as its object the provision of a refrigerant condenser which enables the heat exchange rate to be designed to a high value by specifying the optimal condensation distance in a condenser constructed with the refrigerant passage turned back and forth.
The present invention achieves the above object by the provision of a refrigerant condenser which is provided with:
a plurality of superposed tubes,
a pair of headers joined to the tubes at the two ends, and
separators disposed inside the headers for dividing the tubes into a plurality of groups,
a high temperature, high pressure gaseous refrigerant flowing through the tube groups changing in direction of flow in the headers,
when the number of times the direction of flow is changed in the headers being N (integer) and the distance between the pair of headers being W (unit: mm), the condensation distance L (unit: mm) of the refrigerant being expressed by L=(N+1)W,
the condensation distance L (unit: mm) being L=400+1180 de to 700+1180 de when the equivalent diameter in the tubes corresponding to the tube area is de (unit: mm) and de<1.15.
When the condensation distance L of the refrigerant condenser is set to a value calculated by the above-mentioned equation, the heat exchange rate of the refrigerant condenser becomes optimal, so by setting the number of turns of the refrigerant passage so that the above equation is satisfied, it is possible to obtain a refrigerant condenser with an optimal heat exchange rate.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and effects of the present invention will become clearer from the following detailed description of embodiments made with reference to the drawings, in which:
FIG. 1 is a view of the relationship between the equivalent diameter of the tubes and the condensation distance in an embodiment of the present invention;
FIG. 2 is a schematic view of the construction of a heat exchanger;
FIG. 3 is a view of the relationship between the number of turns of the refrigerant passage, the combination of the tubes, and the condensation distance;
FIG. 4 is a graph of the relationship between the number of turns of the refrigerant passage and the ratio of performance with respect to 0 turns;
FIG. 5 is another graph of the relationship between the number of turns of the refrigerant passage and the ratio of performance with respect to 0 turns;
FIGS. 6A and 6B are sectional views of the core tubes;
FIG. 7 is a graph of the relationship between the core width and the optimal number of turns;
FIG. 8 is a schematic view of the construction of a heat exchanger in the related art; and
FIG. 9 is a view of the relationship between the equivalent diameter of tubes and the condensation distance in tubes with a small equivalent diameter.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Below, an embodiment of the present invention applied to a refrigerant condenser of a car air-conditioner is described with reference to FIG. 1 to FIG. 7. FIG. 2 shows an MF type refrigerant condenser. In FIG. 2, a pair of headers 11 and 12 are connected by a core 13. The core 13 is comprised of a plurality of tubes 13a comprised of flat tubes between which are welded corrugated fins 13b. Separators 14 are disposed at predetermined positions in the headers 11 and 12. It is possible to set the number of turns of the refrigerant passage to any number as shown in FIG. 3 by the position of disposition of the separators 14. That is, when there are 32 tubes 13a, with 0 turns, all the 32 tubes 13a form a refrigerant passage oriented in one direction. In this case, the condensation distance L becomes W. Here, W is the distance between the headers 11 and 12 and matches with the lateral width of the core 13. With 1 turn, it is possible to set the tubes 13a to a combination of 16 and 16, a combination of 24 and 8, etc. In this case, the condensation distance L becomes 2W. Further, with 2 turns, it is possible to set the tubes 13a to a combination of 11, 11, and 10, a combination of 16, 12, and 4, etc. In this case, the condensation distance L becomes 3W. FIG. 3 shows an example of a combination of the tubes 13a, but is possible to set any combination.
FIG. 4 and FIG. 5 show the trend in the number of turns of the refrigerant passage when the core size is set to various dimensions in the case of an equivalent hydraulic diameter de of the inside of the tubes 13a of 0.67 mm. That is, FIG. 4 shows the ratio of performance with respect to 0 turns when setting the core width W to from 300 mm to 700 mm in 100 mm increments and setting the number of turns of the refrigerant passage from 1 to 5 in a heat exchanger with 24 tubes 13a, a core height H of 235.8 mm, and a core thickness D of 16 mm (FIG. 2). FIG. 5 shows the ratio of performance with respect to 0 turns when setting the core width W to from 300 mm to 700 mm in 100 mm increments and setting the number of turns of the refrigerant passage from 1 to 6 in a heat exchanger with 40 tubes 13a, a core height H of 387.8 mm, and a core thickness D of 16 mm. The dots on the curves in FIG. 4 and FIG. 5 show the optimal performance points of each. The "equivalent diameter de" indicates the hydraulic diameter corresponding to the total sectional area of combined bores of a single tube 13a, since the shape of the tubes 13a is at a section of the tube 13a, usually the sectional shapes shown in FIGS. 6A and 6B. That is, it is defined as de (equivalent diameter)=4×(total hydraulic sectional area)/(total wet edge length).
Here, various combinations of numbers of tube 13a are considered for various numbers of turns, but FIG. 4 and FIG. 5 show the ones with the optimal performance obtained as a result of calculation. That is, the performance of a condenser is determined by the balance of the improvement of the heat exchange rate and the pressure loss. The two have effects on each other, so it is possible to derive this by converting the relationship between the two to a numerical equation. Using this, it becomes possible to find the efficiencies of various heat exchangers. Further, for this calculation, detailed heat transmission rate characteristics and pressure loss characteristics were found by experiment and the results were used to prepare a simulation program and perform analysis. For the settings of the parameters at this time, the heaviest load conditions in the refrigeration cycle of a car air-conditioner were envisioned and use was made of an air temperature at the condenser inlet of 35° C., a condenser inlet pressure of 1.74 MPa, a superheating of the condenser inlet of 20° C., a subcooling of the condenser outlet of 0° C., an air flow of the condenser inlet of 2 m/s, and a refrigerant of HFC-134a. The analysis and the experimental findings were compared. As a result, the present inventor confirmed that the results of analysis and the experimental values substantially matched in the range of an equivalent diameter of the tubes 13a of 0.6 mm to 1.15 mm. Further, the inventor confirmed that the number of turns giving the optimal performance shown in FIG. 4 and FIG. 5 (optimal number of turns) is substantially the same even if the pitch of the fins differs or the core thickness D differs.
From FIG. 4 and FIG. 5, it is learned that so long as the core width W is the same, the optimal number of turns is the same even if the number of tubes 13a differs. This means if the core width is the same, the optimal number of turns is the same regardless of the combination of the numbers of tubes 13a.
FIG. 7 shows the results of the above calculation for tubes 13a of different equivalent diameters de to find the optimal number of turns for different core widths W. In this case, while there are only whole numbers of turns in actuality, regions other than those of integers are also shown so as to illustrate the trends.
Now then, in FIG. 7, looking at the tubes 13a with a de of 0.67 mm for example, the condensation distance L at the optimal number of turns is 3 when W=300 mm, so L=(3 (turns)+1)×300=1200 mm. When W=400 mm, it becomes 2 turns, so L=(2+1)×400=1200 mm. When W=500 mm, it becomes 2 turns, so L=(2+1)×500=1500 mm. When W=600 mm, it becomes 1 turn, so L=(1+1)×600=1200 mm. When W=700 mm, it becomes 1 turn, so L=(1+1)×700=1400 mm. Further, when the equivalent diameter de of the tubes 13a is 0.9 mm, the condensation distance L becomes 1500 mm when W=300 mm, 1600 mm when W=400 mm, 1500 mm when W=500 mm, 1800 mm when W=600 mm, and 1400 mm when W=700 mm. Further, when the equivalent diameter of the tubes 13a is 1.15 mm, the condensation distance L becomes 1800 when W=300 mm, 2000 mm when W=400 mm, 2000 mm when W=500 mm, 1800 mm when W=600 mm, and 2100 mm when W=700 mm. Usually, the core width W of a refrigerant condenser used for a car air-conditioner is about 300 mm to 800 mm, so from the results of the above calculations, it is learned that when the equivalent diameters de of the tubes 13a are the same, there is not that much effect on the core width W and the optimal condensation distance L lies in a certain range.
Therefore, it is possible to specify the optimal condensation distance L for an equivalent diameter de of tubes 13a. FIG. 1 shows the results when changing the equivalent diameters de and finding by the above analysis the range of the optimal condensation distances L for those de. Linear approximation of the data obtained enables the optimal condensation distance L to be set as
L=400 +1180 de to 700+1180 de (1)
where the units of L and de are also millimeters.
Therefore, if the equivalent diameter de of the tubes 13a of the core 13 of the heat exchanger is known, it is possible to find the optimal condensation distance L from equation (1), so it becomes possible to set the optimal number of turns (N) by finding the number of turns matching that condensation distance from the following equation (2):
N (number of turns)=L/W-1 (2)
Further, since the number of turns must be an integer, it is necessary to round off the number of turns found from equation (2).
In recent years, advances in the manufacturing technology for tubes of refrigerant condensers have made possible the production of tubes with extremely small equivalent diameters. If the above equation (1) is applied to such very small tubes, the number of turns is set to 0. For example, FIG. 9 shows the results obtained by using the above-mentioned simulation program to find the optimal condensation distance at an idle high load (A) and a 40 km/h constant load (B) for tubes with an equivalent diameter de of less than 0.60 mm. Looking at just the line of the idle high load (A), when the equivalent diameter is 0.18 mm to 0.5 mm, the optimal condensation distance L becomes 300 to 800 mm, so as mentioned above, 0 number of turns is the optimal specification when the core width W is 300 mm to 800 mm.
In this way, by making the tubes ones with an equivalent diameter of 0.18 mm to 0.5 mm, it is possible to provide a refrigerant condenser with a good efficiency with 0 number of turns. A condenser with 0 number of turns does not require any separators for dividing the headers, so the work of inserting the separators and the process of detecting leakage of refrigerant from the separator portions become unnecessary. Further, it becomes possible to simplify and standardize the shape of the header portions. Further, compared with the case of use of tubes with a large equivalent diameter as shown in FIG. 9, the fluctuation in the optimal condensation distance due to load fluctuations becomes smaller, so it is possible to maintain the optimal state for the load conditions even if the load conditions fluctuate.
As explained above, in the present invention, the optimal condensation distance L is determined from the equivalent diameter de of the tubes 13a of the core 13 of the heat exchanger and the optimal number of turns of the refrigerant passage is found from the condensation distance L, so the present invention differs from the related art, which only suggested that an increase of the number of turns or a decrease of the sectional area of the passage contributed to an improvement of the heat exchange rate and therefore it is possible to design a heat exchanger with a high heat exchange rate. | 4y
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This application is a divisional of Ser. No. 09/095,703, filed on Jun. 9, 1998, now U.S. Pat. No. 5,968,422, which claims the benefit of U.S. Provisional Application No. 60/058,096 filed on Jun. 30, 1997.
BACKGROUND OF THE INVENTION
This invention relates to a method of injection molding contact lens molds for cast molding contact lenses having a rotationally asymmetric lens surface, and apparatus for carrying out the method.
One method in practice for making contact lenses is cast molding. Cast molding of contact lenses involves depositing a curable mixture of polymerizable monomers in a mold cavity formed by two mold sections, curing the monomer mixture, and disassembling the mold assembly and removing the lens. Other processing steps, for example, hydration in the case of hydrogel lenses, may also be employed. One mold section forms the anterior lens surface (anterior mold section), and the other mold section forms the posterior lens surface (posterior mold section). Prior to the cast molding of the contact lens, each of the mold sections is formed by injection molding a resin in the cavity of an injection molding apparatus. Mounted in the injection molding apparatus are tools for forming the optical surfaces on the mold sections. Whereas the mold sections are typically used only once for casting a lens, the injection molding tools are used to make hundreds of molds.
Several known cast molding methods have the potential to mold a finished contact lens, for example, U.S. Pat. No. 5,271,875 (Appleton et al.). Since these methods avoid time-consuming and labor-intensive operations such as lathing, the methods have been found to offer the potential to reduce production time and cost for the manufacture of spherical contact lenses.
However, various problems have been encountered in employing cast molding technology for manufacturing other types of contact lenses, especially contact lenses that have at least one rotationally asymmetric surface. As one example, toric contact lenses (i.e., contact lenses having a toric optical zone that are used to correct refractive abnormalities of the eye associated pith astigmatism) have at least one surface that is not rotationally symmetric. The problems encountered may be due to several factors. First, the toric optical zone is not spherical. Second, toric contact lenses include some type of ballast (such as prism ballast or slab-off zones) to inhibit rotation of the lens on the eye so that the cylindrical axis of the toric zone remains generally aligned with the axis of the astigmatism; in order to provide such ballast, the edge thickness of the lens is not uniform about the entire circumference of the lens. As another example of such lenses, many mulitfocal designs are not rotationally symmetric.
Applicant found that, in forming contact lens molds for molding lenses having a rotationally asymmetric lens surface, problems were encountered in consistently obtaining contact lens molds having the same geometries. Such inconsistencies in the contact lens mold geometries translated to inconsistencies in cast molding contact lenses in the molds. The present invention solves this problem.
SUMMARY OF THE INVENTION
The invention provides an improved method for injection molding a contact lens mold having a rotationally asymmetric molding surface. The method comprises: providing a first molding tool including a convex molding surface, and a second molding tool including a concave molding surface, wherein one of said convex or concave molding surfaces has an optical quality finish and is rotationally asymmetric, said one molding surface for forming an optical surface on the contact lens mold, and the other of said convex or concave molding surface is rotationally asymmetric; positioning the molding tools in opposed relationship to form a space therebetween, such that the respective molding surfaces are spaced substantially uniformly across their surfaces; and injecting a plastic resin into a space formed between the molding surfaces.
The method is especially useful for injection molding contact lens molds having a mold cavity defining surface for forming a toric contact lens surface molded thereagainst, and more particularly, for contact lens molds having a mold cavity defining surface shaped to provide ballast to a contact lens surface molded thereagainst.
The invention further includes an assembly for carrying out the method, and contact lens molds formed by the method.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross-sectional view of a representative toric contact lens.
FIG. 2 is a schematic exploded view of a representative mold assembly.
FIG. 3 is a schematic cross-sectional view of the mold assembly of FIG. 2 assembled for cast molding a contact lens.
FIG. 4 is a schematic cross-sectional view of tooling for injection molding an anterior mold section of the assembly shown in FIGS. 2 and 3 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 schematically illustrates a representative contact lens having a rotationally asymmetric surface. For this described preferred embodiment, contact lens 1 is a toric contact lens, although the invention is applicable to other contact lenses having at least one rotationally asymmetric surface. As used herein, the term “rotationally asymmetric surface” denotes a surface that is not a second-order surface of revolution, such as a torus section.
Central zone 11 of posterior surface 3 is toric, i.e., this zone has a toric surface that provides the desired cylindrical correction. Posterior surface 3 may optionally include at least one peripheral curve 12 surrounding the central toric zone 11 . For the described embodiment, central zone 21 of anterior surface 4 is spherical, and the spherical curve is matched with central zone 11 to provide the desired spherical correction to the lens. Anterior surface 4 includes at least one peripheral curve 22 surrounding central zone 21 . Lens 1 is provided with ballast so that the lens maintains a desired rotational orientation on the eye. For the described embodiment, schematically shown in FIG. 1, peripheral section 24 has a different thickness than an opposed peripheral section 25 of the lens periphery due primarily to the ballast in surface 4 ; thus, anterior surface 4 is not rotationally symmetric. Other ballast types for inhibiting rotation of the contact lens on the eye are known in the art, and the invention is applicable for such other ballast types that require a rotationally asymmetric surface. It is further noted that for toric lens designs, the centerpoint of central zone 21 is not necessarily aligned with the center of lens 1 , thereby further contributing to surface 4 not being rotationally symmetric.
A representative mold assembly 25 for the method of this invention is shown in FIGS. 2 and 3. The mold assembly includes posterior mold 30 having a posterior mold cavity defining surface 31 (which forms the posterior surface of the molded lens), and anterior mold 40 having an anterior mold cavity defining surface 41 (which forms the anterior surface of the molded lens). Each of the mold sections is injection molded from a plastic resin, such as polypropylene or polystyrene, in an injection molding apparatus, as described in more detail below. When the mold sections are assembled, a mold cavity 32 is formed between the two defining surfaces that corresponds to the desired shape of the contact lens molded therein. Accordingly, for the described embodiment, posterior mold cavity defining surface 31 has a toric central zone (for forming the toric posterior surface of the toric contact lens) having a cylindrical axis, and anterior mold cavity defining surface 41 has a configuration that will provide ballast to a lens molded in mold cavity 32 . Of course, surfaces 31 , 41 may also include curves for forming desired peripheral curves on the lens, and the central zones of surfaces 31 , 41 may be designed to provide a desired spherical correction to the molded toric lens.
As mentioned above, the posterior and anterior mold sections are injection molded from a plastic resin in an injection molding apparatus. FIG. 4 illustrates schematically an injection mold arrangement for the injection molding of anterior mold section 40 . As seen in the Figures, anterior mold section 40 includes surface 42 opposed to anterior mold cavity defining surface 41 , surfaces 41 and 42 defining segment 43 therebetween of mold section 40 . Tools 51 , 52 are mounted in the injection molding apparatus. Tool 51 has an optical quality finish on its molding surface 53 since tool 51 is used to form mold anterior cavity defining surface 41 . (As used herein, the term “optical quality finish” denotes a molding surface that is sufficiently smooth for ultimately forming the optical surface of a contact lens, e.g., the produced contact lens is suitable for placement in the eye without the need to machine or polish the formed lens surface.) Tool 52 , used to form opposed surface 42 , does not need to have an optical quality finish on its molding surface 54 since opposed surface 42 of contact lens mold 40 does not contact the polymerizable lens mixture in casting contact lenses, i.e., opposed surface 42 does not form part of mold cavity 32 .
According to conventional methods of injection molding such a contact lens mold, the shape of opposed surface 42 was not considered particularly critical. Therefore, tool molding surface 54 would generally have a shape that was easy to machine in order to avoid unnecessary labor and expense in forming the molding surface on tool 52 , i.e., this tool molding surface would be formed of rotationally symmetric curves especially spherical curves.
However, applicant found that, in forming contact lens molds for molding lenses having a rotationally asymmetric lens surface, a problem of inconsistent molding of contact lens molds was encountered. More specifically, it was discovered that when surface 53 of tool 52 was made with a rotationally symmetric molding surface as in conventional methods, it was difficult to obtain contact lens molds having consistent geometries, which translated to inconsistencies in the casting of lenses in the contact lens molds. It is believed that there was still sufficient mismatch between the shapes of surfaces 41 and 42 , especially in the region of the molding surfaces that provide ballast, that uneven resin flow occurred in injection molding the contact lens mold, thus causing the inconsistency in the injection molding process.
The present invention solved this problem by providing molding tool 52 with a molding surface 54 that is rotationally asymmetric, such that when the two molding tools 51 , 52 are positioned in opposed relationship, molding surfaces 53 , 54 are spaced substantially uniformly across their surfaces. Preferably, tools 51 and 52 are locked into these positions with respect to one another. It is believed that this uniformity in the space formed between the molding surfaces 53 , 54 results in more uniform flow of resin during injection molding, and thereby provides more consistency in the injection molding of the contact lens mold sections. Preferably, surface 54 has curves approximating each of the curves on surface 53 . Molding surfaces 53 , 54 should be shaped so that the thickness of section 43 varies no more than 0.2 mm, more preferably no more than 0.15 mm, and especially no more than 0.1 mm, across its profile.
(It is noted that due to the scale of FIG. 4, the various curves of surfaces 41 and 42 are not visibly illustrated; similarly, the various curves of surface 31 is not illustrated in FIG. 3 . However, for the described embodiment, it is evident that surface 31 would be shaped to provide contact lens surface 21 , and surfaces 41 , 42 of the tools would be shaped accordingly. As discussed above, for the described embodiment, lens 1 does not include a uniform peripheral thickness due primarily to inclusion of a ballast.)
Tools 51 , 52 are typically made from brass, stainless steel or nickel or some combination thereof, and the desired molding surface is formed on the tools according to generally methods known in the art, such as lathe cutting. Alternately, if the tool surface has a shape that is difficult to lathe cut, other methods are generally available in the art, such as electrodischarge machining. After forming the desired surface, surface 53 of tool 51 is polished to achieve precision surface quality so that no surface imperfections are transferred to the mold section being injection molded therefrom. Surface 54 of tool 52 does not require such degree of polishing, since it is not used to form an optical surface, and therefore, the molding surface 54 of tool 52 does not need to correspond exactly to surface 53 . As shown schematically in FIG. 4, the end of tool 52 opposite surface 54 is designed to mount the tool in insert 55 , surrounded by ejector sleeve 56 , and tool 51 is surrounded by sleeve 57 . This assembly is mounted in blocks 58 , 59 , with a gate 60 provided for introducing resin As would be apparent to one skilled in the art, the exact design or configuration to accommodate the molding tools will depend on the injection molding apparatus.
Although certain preferred embodiments have been described, it is understood that the invention is not limited thereto and modifications and variations would be evident to a person of ordinary skill in the art. As one example, the invention is applicable to toric contact lenses having other ballast means than that illustrated for the described embodiment, and for other types of contact lenses having at least one rotationally asymmetric surface. As another example, the invention is not limited to injection molding of anterior mold sections, but is also applicable to injection molding of posterior mold sections that have a rotationally asymmetric mold cavity defining surface. As yet another example, the invention is applicable to contact lens mold types other than those illustrated in FIGS. 2 to 4 , and the various injection molding set-ups therefor. | 4y
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BACKGROUND OF THE INVENTION 1. FIELD OF THE INVENTION
This invention concerns the field of power supply systems for telecommunications applications and, in particular, to power supply systems for generating ringing voltage signals in remotely located telecommunications units.
2. Prior Art Systems and Methods
In a conventional telephone network, a wire pair extends from a "central office" location to a subscriber's premises. Battery voltage is typically applied to the wire pair at the central office to power the subscriber's telephone service set(s), and an AC voltage, traditionally a nominal 90 volts at 20 Hertz, is applied to "ring" the service set(s) at the subscriber's premise, in order to signal an incoming call and induce the subscriber to remove the handset from its cradle, creating an "off hook" condition. The standard telephone service set within the traditional U.S. telephone system includes an audible call annunciator, classically a bell, more recently a piezoelectric resonator, which is broadly resonant at a given "ringing frequency," broadly in a range of 16 to 67 hertz, wherein, for example, 20 hertz is a typical ringing frequency used in the U.S. and 25 hertz is a typical ringing frequency used in Europe.
Ringing voltage is generated at a central office in a number of ways. For example, a rotary generator, or ringing machine, may be employed consisting of a single-speed motor, either AC or DC, depending upon the local power supply. The motor rotates one or more AC generators which generate the desired ringing frequencies and voltages. Magnetic generators operating from AC power mains at the central office have also been used to generate ringing signals. Such generators employ resistors, transformers and tuned circuits of inductors and capacitors in order to develop the desired ringing signal. Vibrating reed converters have also been employed to generate ringing voltage from a 48 volt (DC) central office battery supply. These converters typically include two magnetic coils, an armature and a reed assembly mounted on a frame, and convert the 48 volts DC into an AC square wave of the desired frequency for ringing. A device such as a mechanical interrupter is typically employed to divide the ringing generator's signal into alternating ringing and silent periods, the traditional U.S. standard being alternating periods of two seconds "ringing" and four seconds "silent" For example, one implementation has been a motor for rotating a shaft carrying a number of cams which operate switch contacts that switch the ringing signal on and off. All of the foregoing approaches are generally bulky, however, and require significant amounts of primary operating power.
Fiber optic networks are proliferating within U.S. and foreign telecommunications networks, wherein communication signals are sent via lightwave signal transmission over an optical medium, typically an "optical fiber", instead of via electrical signal transmission over a metallic medium, typically a wire pair. Known fiber optic telecommunications distribution networks typically comprise a plurality of optical fibers extending from a central office location to a remotely located subscriber interface unit (SIU), wherein each optical fiber comprises a communications path for one or more subscribers served from the SIU. At the SIU, the optical signals are converted to electrical signals and then transmitted the remaining distance to each subscriber over a traditional wire pair. Because centralized signal transmission for several subscribers over an optical fiber is often more cost effective than individual signal transmission over a wire pair, it is desirable to be able to locate each SIU as close as possible to the subscribers it serves.
It is not possible, however, to send central office battery power and ringing voltage signals via optical transmission. Thus, operating power and ringing signal generation must be provided locally at each SIU and delivered to subscribers in an appearance functionally identical to the existing "wire plant" network discussed above. For example, U.S. Pat. No. 5,321,596, entitled "DC/DC/AC Power Supply For A Subscriber Interface Unit" issued to D. Hurst and assigned to the assignee of the present application, discloses an efficient and compact power supply system for generating on-demand ringing voltage signals in an SIU. The Hurst system includes a DC to DC switched mode power supply, which converts a source of DC primary power into DC operating power for an SIU. A ringing voltage signal is derived by converting a reference sine wave into an AC voltage signal derived from a DC to AC power converter. In one described embodiment, the ringing voltage signal is a 56 volts-RMS sine wave centered at -48 volts. The ringing voltage signal is centered at -48 volts in order to provide sufficient "offset" voltage from ground, which normally requires an offset of at least -40 volts, so that the SIU can detect an off-hook condition on a particular subscriber line receiving the ringing signal.
Most functions of an SIU that consume operating power, (e.g., optical/electrical signal conversion, off-hook monitoring, call processing, etc.), require a substantially constant operating power level, P SIU =V SIU *I SIU , where V SIU represents available operating voltage supplied to the SIU, and I SIU represents the operating current load of the SIU. If the SIU operating power level falls below a minimum threshold for any non-negligible duration of time, (e.g., for more than 10 ms), the SIU will cease operation until the available operating power level recovers, thereby causing undesirable service interruptions and call failures. Because the required operating power is constant, a drop in the operating voltage level will cause the SIU to attempt to pull additional current in order to maintain minimum threshold power. There are limits, however, to the SIU's ability to increase current in order to maintain minimum operational power because of the corresponding additional drain on the operating voltage supply.
In particular, as demonstrated in FIG. 1, when the SIU current load is less than the current load at maximum power, the relationship between the operating voltage level V SIU and current load I SIU is linear and stable. However, when the current load exceeds the current load at maximum power P MAX , the operating voltage becomes unstable and can drop precipitously. Thus, for stable operation of an SIU, a certain, minimum voltage supply, V MIN , must be maintained in order to prevent the total operating power from dropping below the required threshold.
Operating voltage for an SIU is typically supplied over a "feeder" line from a voltage source. In some instances, the voltage source is local to the SIU. In many cases, however, the feeder line extends over a substantial distance, thereby significantly reducing the available voltage supply at the SIU location because of the resistance of the feeder line (R FEEDER in FIG. 1). Because the SIU voltage supply is directly related to the feeder line resistance R, feeder line distances must often be kept shorter than is otherwise desirable, (e.g., no longer than where R =R MAX in FIG. 1), and can represent a limiting restraint on the distance an SIU can be located from a central office. Further, SIU operating cost constraints typically require that power supplied to an SIU be limited to that actually necessary to meet applicable service levels--i.e., sufficient to ensure that call completion and call processing functions are fully operational under most all, non-extraordinary, operating conditions.
Voltage used for ringing signals imposes a relatively significant transient load on the operating power of an SIU, e.g., typically up to 4 watts per line. In particular, simultaneous ringing of two or more lines can cause a severe impact on the operating voltage supply of an SIU, even if the overlap is only momentary. For illustrative purposes, FIG. 2 depicts the incremental impact of three subscriber lines, A, B, and C, respectively, on the current load and corresponding operating voltage of an SIU, where subscriber lines A, B and C each require simultaneous ringing signal generation. In particular, during each interval T IMAX , where all three subscriber lines require ringing voltage generation, the operating voltage level falls below V MIN , Creating an "undervoltage" condition.
Built into traditional telecommunications industry service level criteria is the likelihood of a very small percentage of subscriber lines in an SIU requiring simultaneous ringing voltage generation during a particular time interval. However, the relatively large corresponding operating voltage supply required to ensure that sufficient stand-by power is available for accommodating simultaneous on-demand ringing signal generation for more than a very small percentage of subscriber lines would impose a prohibitively high operating cost. As a result, the operating voltage supply of an SIU, V SIU , is susceptible to low, or "undervoltage" conditions, if simultaneous ringing voltage is required for more than a small percentage of subscriber lines, i.e., if the number of subscriber lines simultaneously requiring ringing voltage exceeds the capability of the power supply. Other factors, such as, for example, fluctuating input voltage levels and/or feeder line resistance may further cause the operating voltage supply of an SIU to be particularly susceptible to an undervoltage condition, even when only a small number of subscribers require simultaneous ringing voltage generation.
Thus, it is desirable to provide a power supply system for generating on-demand ringing voltage signals in an SIU, or the like, wherein corrective steps are taken during a low voltage condition to limit power consumed by ringing voltage generation, in order to ensure that sufficient continuous operating power is delivered to the SIU and uninterrupted service maintained, without imposing significant stand-by power supply costs.
SUMMARY OF THE INVENTION
According to the present invention, a voltage detection circuit is provided in conjunction with a power supply system for generating ringing voltage signals in an SIU, or other remote telecommunications unit. The detection circuit monitors the available operating voltage level of the SIU and, if an "undervoltage" condition is detected, causes a ringing reference signal to temporarily change state from an AC sine wave to a steady-state DC voltage. The reference signal is used to shape a voltage output signal generated by a DC to AC power conversion operation for supplying on-demand ringing voltage signals. Under "normal" SIU operating voltage conditions, i.e., where there is sufficient operating voltage available for providing threshold operating power to the SIU, the converted voltage is shaped by the AC sine wave reference signal into a AC sine wave of appropriate frequency and voltage to provide standard ringing functionality, centered at a sufficiently negative offset voltage to detect an off-hook condition, preferably -48 volts. When an undervoltage condition is detected in the SIU, i.e., where there is not sufficient voltage available to operate the SIU without risking failure, the converted voltage is shaped by the reference steady-state DC reference signal into a steady-state DC voltage, which, while unable to provide ringing functionality, is sufficiently offset so that an off-hook condition can still be detected by the SIU. Because the steady-state DC voltage imposes a significantly lower transient current load on the SIU operation than does the AC sine wave ringing voltage signal, the voltage supply of the SIU is allowed to restore to a safe operating level.
Upon initial detection of an undervoltage condition in an SIU, the DC voltage reference signal is employed in lieu of the AC sine wave for a predetermined time interval, preferably at least 20 ms and no more than 100 ms, to allow proper restoration of the SIU operating voltage level, while minimizing audible ringing signal loss to subscribers. If, at the end of the predetermined time interval, an undervoltage condition is still detected, then the DC voltage reference signal is maintained for an additional time interval, with the process repeated until the SIU voltage level is restored to a sufficient operating level, or until ringing signal generation is no longer required.
Thus, it is an object of the invention to provide a power supply system for generating on-demand ringing signals in a remote telecommunications subscriber interface unit, wherein transient ringing voltage is eliminated during low operating voltage conditions to ensure continuous operating power is available to the SIU and uninterrupted service is maintained. One advantage of the invention includes the ability to extend the power supply feeder distance from a voltage supply source to an SIU.
As will be apparent to those skilled in the art, other and further objects and advantages will appear hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
It is to be understood that the accompanying drawings are provided for the purpose of illustration only, and are not intended as a definition of the limits of the invention. The drawings illustrate both the design and utility of preferred embodiments of the present invention, in which:
FIG. 1 depicts exemplary power curves for a typical SIU operation;
FIG. 2 depicts the impact on available operating voltage in a typical SIU operation when ringing voltage is simultaneously required for a plurality of subscriber lines;
FIG. 3 is a schematic diagram of a preferred embodiment of the present invention;
FIG. 4 depicts a standard AC sine wave ringing signal under normal SIU operating voltage conditions; and
FIG. 5 depicts implementation of a DC offset voltage on a ringing signal during an undervoltage condition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 3 illustrates a power supply system for generating ringing voltage signals in a remote telecommunications subscriber interface unit (SIU). The system comprises a flyback power converter 10, for converting a DC voltage supply V SIU into AC ringing voltage V RING . The converter 10 includes a primary side transistor switch 12, such as a field-effect-transistor switch (FET) or the like, operated by a converter control circuit 14, which periodically causes current to be transferred through a pair of secondary transformer windings, 16a and 16b, respectively, wherein winding 16a circulates current through a first, "positive" rectifying diode 18a, and winding 16b circulates current through a second, "negative" rectifying diode 18b, respectively. A pair of switches 20a and 20b build a ringing voltage signal 22 from positive and negative current supplied through rectifying diodes 18a and 18b, respectively. Ringing voltage signal 22 is smoothed through an LC filter circuit 24 and provided as ringing voltage VRmNG for on-demand use in subscriber line(s) served by the SIU. In preferred embodiments, additional ringing voltage signals may be generated for use by substantially similar converter circuit operations (not shown) provided in parallel with converter 10.
A voltage detection circuit 26 monitors the SIU operating voltage level V SIU at the primary side input to power converter 10. Under "normal" SIU operating voltage conditions, i.e., where V SIU is equal to or greater than a predetermined minimum required operating voltage level V MIN , a first, low voltage control signal 28 is output by the detection circuit 26 into a reference signal selection circuit 30, wherein control signal 28 triggers the reference signal selection circuit 30 to output a low voltage (AC) reference sine wave 32. Sine wave 30 is preferably transmitted within a range of 16 to 67 hertz, with the actual frequency selected according to the desired ringing frequency for the SIU subscriber lines. When an "undervoltage" condition is detected, e.g., where V SIU is less than V MIN , a second, low voltage control signal 34 is output by voltage detection circuit 26 into the reference signal selection circuit 30, triggering circuit 30 to output a steady-state, low (DC) voltage signal 36, in lieu of (AC) reference sine wave 32.
Various known circuit design and switching techniques may be employed to achieve the aforementioned reference signal generation and selection of either an (AC) sine wave signal 32 or a steady-state low (DC) voltage signal 36, depending on the voltage level V SIU detected at the input to the ringing signal power converter 10. By way of example(s), a low voltage (AC) reference sine wave may be generated by imputing a high frequency AC sine wave reference, (e.g., 200 hertz or greater), into a step counter, such as a Johnson step counter, and then converting the counter output signal into a smooth, low frequency sine wave via a filter circuit. A steady-state, low (DC) voltage signal may be provided by a reference voltage source, preferably no more than 2.5 volts and substantially accurate. An operational-amplifier type feedback hysteresis may be employed in conjunction with one or more transistor switches to select between the (AC) sine wave and (DC) steady-state voltage, based on a selected voltage level differential between control signals 28 and 34. Other known circuit switching techniques may also be employed to achieve the change in ringing reference signals based on the detected voltage level of the SIU operating voltage.
An electrical path 38 is provided between the output side of the power converter 10 and a summing junction 40, wherein ringing voltage signal 22 is input into summing junction 40 via path 38. Reference signal 32 or 36 is also input into summing junction 40, wherein summing junction 40 compares reference signal 32 or 36 with ringing signal 22. A feedback signal 42 is output from summing junction 40 and input into positive and negative switch drivers 44 and 46, respectively, which drive positive current switch 20a and negative current switch 20b, respectively, in order to shape ringing voltage signal 22 into the same form as the particular reference signal 32 or 36. Preferably, a resistor 48 is provided across electrical path 38 to reduce the voltage of signal 22 prior to when it is compared to reference signal 32 or 36, in order to increase the accuracy of feedback signal 42.
As illustrated in FIG. 4, during normal SIU voltage conditions, i.e., when V SIU ≧V MIN , ringing output voltage V RING is shaped by (AC) reference signal 32 in the form of an AC sine wave. In the embodiment shown, V RING is supplied at 56 volts-RMS by the power converter operation, having a peak nominal voltage of around 82 volts. V RING is centered at a -48 volts offset in order for the SIU to detect an off-hook condition and is transmitted at a frequency of 20 hertz, i.e., with a peak to peak period of 50 ms. As depicted in FIG. 5, during an undervoltage condition, i.e., when V SIU <V MIN , illustrated as occurring at t=a, ringing output voltage V RING is shaped by (DC) reference signal 36 in the form of a steady-state, -48 volts DC signal. As demonstrated by comparing shaded areas V AC and V DC of FIGS. 4 and 5, respectively, when implemented as a DC offset signal, V RING consumes considerably less operating voltage during a 50 ms cycle than when implemented as a normal AC ringing signal.
Preferably, voltage detection circuit 26 is provided with delay means (not shown), such as an RC or LC delay circuit, to maintain the (undervoltage) control signal 34 "on" for a predetermined amount of time, T DC , when an undervoltage condition is first detected, regardless of whether the SIU operating voltage V SIU returns to a sufficient operating level prior to the duration of T DC . T DC is preferably selected to be at least 20 ms to allow for voltage recovery in an SIU and is preferably greater, e.g., 50 ms in the embodiment illustrated in FIG. 5. By implementing a "minimum" recovery time T DC , V SIU is allowed to restore to a safe operating level and then be maintained at that level for a sufficient period of time to ensure stable operation. In this manner, rapid, alternating "on/off" selection between AC and DC ringing reference signals by selection circuit 30 is avoided. A maximum holding time, preferably no more than 100 ms, --i.e., no more than two (AC) sine wave cycles at 20 hertz, is also preferred in order to avoid unnecessary disruption of audible ringing signal transmission over the subscriber line. If, at the end of the predetermined time interval, an undervoltage condition in V SIU is still detected by circuit 26, then control signal 34 and corresponding DC reference signal 36 are maintained for an additional time interval T DC , with the process repeated until sufficient SIU operating voltage is finally restored, or until ringing signal generation is no longer required in the SIU.
Thus, a ringing voltage power supply system for a remote telecommunications subscriber interface unit has been disclosed, including SIU voltage detection circuitry operating in conjunction with variable-state ringing reference signal generation. While embodiments and applications of the present invention have been illustrated and described, it would be apparent to those skilled in the art that many other modifications are possible without departing from the inventive concepts herein.
The scope of the invention, therefore, is not to be restricted except in the spirit of the appended claims. | 4y
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BACKGROUND OF THE DISCLOSURE
This disclosure is directed to a device to protect male pipe threads during shipment or handling; the thread protector is installed on the exposed threads of pipe in an assembled pipe system to protect from corrosion above ground, under ground or under water. As an example, the thread protector is particularly advantageous for use with small diameter pipe, but not limited to 1/8" to about 6" having tapered threads known as dry seal threads. This pipe is most often galvanized at the mill and shipped in 20 foot lengths to a distributor or end user for cutting to length. Threads will be added to conform to system requirements. When a thread is machined on the pipe, the protective coating (e.g., galvanizing) is removed thus exposing unprotected metal. Cutting and threading removes the protective coating and thereafter leaves an unprotected male thread.
Pipe thread protectors installed at the pipe mill may include shipping wrappers such as paper or tape covers. Also, disposable end caps are known. In very general terms, the variety is unlimited but protection of the pipe (both before and after installation) is irregular, and especially so around the male threads on the pipe. It is fairly common to use metal pipe which has been coated with a thin film (usually galvanizing) to prevent corrosion. In actuality, it does not really prevent corrosion, rather, it merely delays the onset of corrosion. Where the coating is absent, the corrosion starts even more rapidly. The rate of pipe thread corrosion is dependent on environmental conditions. The measure of corrosive severity increased markedly in humid areas, areas near water and especially areas near the sea coast. For instance, a breeze from a salt water body will cause significantly accelerated corrosion of pipe. It is also true at locations which are exposed to widely fluctuating temperature extremes. These and other variables cause wide variation in threaded pipe longevity. As one example, consider a typical one-family residence which has a conventional threaded pipe connection from the gas main to the gas meter. The exposure variations and risk of damage can be quite severe for the gas meter connections. The gas meter is typically installed out of doors and is exposed to inclement weather. Highly corrosive fertilizers, insecticides, etc. accelerate corrosion. Adding the variables mentioned above, exposed connections may corrode and require replacement in quick order when it is intended to least many years. While the failure date is difficult to predict, but in any event, the threaded connections on the meter must be inspected often and corrosion must be dealt with in all circumstances to improve safety and reduce loss of unmetered gas. Failure of the threaded pipe connections is an expensive repair or replacement job; if the threaded connection life can be extended, then safety is increased and cost is reduced.
Several devices have been used in the past. For instance, Teflon tape (a registered trademark of the DuPont Company) is often applied to the threads, also, shrink sleeves aer known. Various weights of grease, adhesives, sealants or bituminous coatings can also be applied to the threads. They provide some measure of protection. In some instances, the previous devices are detrimental in that they trap fluid condensate or otherwise allow capillary migration of fluid directly to the threaded area. Such flow may be miniscule but it will nevertheless contribute to the damage of threads, perhaps in a fashion unseenby visual inspection. One prior art device is an added threaded sleeve such as that shown in the patent of Schmaus, U.S. Pat. No. 2,101,514. This patent is representative of other pipe thread protectors including U.S. Pat. No. 1,168,196. Primarily, the Schmaus structure suffers from limitations arising out of a dissimilar metal junction which gives rise to currents between the metals which may cause corrosion in the presence of an electrolyte. Moreover, Schmaus does not deal with full thread protection. The last thread on the threaded male pipe is viewed as most subject to failure in a threaded pipe system. With normal installation, mechanical loading acts on the region of the last thread, the most vulnerable part of the pipe. Even though the pipe is galvanized, this will not retard corrosion in exposed last thread region. Again, corrosion may be accelerated depending on the nature of environmental conditions. For all these reasons, the improved device of this disclosure provides protection and is therefore markedly more desirable than the devices of the prior art.
This new, useful and unobvious apparatus is a thread protector which functions as a sleeve or cap which fits over the threads at the time of manufacture. When the pipe is threaded, this device can be installed over the threads. The device length covers the threads in most instances. It has a transverse head or covering which forms a sacrificial disc which is easily punched out of the device covering the open end of the pipe prevents foreign matter entering into the pipe. At the time the threaded pipe is installed, the disc can be cleared to leave a sleeve with a surrounding radial shoulder to provide a structurally substantial member for abutting pipe couplings threaded on the pipe. So to speak, the sleeve is forced up the pipe by the coupling to position the sleeve portion sufficiently along the pipe so that all the threads beyond the coupling are protected. The device abuts against the coupling (female fitting) to cover the threads not within the coupling. A dissimilar metal junction between the protective device and pipe or coupling is avoided because the preferred material of this apparatus is a polymer as will be described below. Moreover, sealing against the atmosphere can be easily achieved by packing with a grease, silicon or other sealant. Capillary liquid flow is prevented around the threaded area and coupling face. The present apparatus thus converts readily from a capped thread protector into a sleeve which covers all the exposed threads and thereby prevents corrosion at the exposed threads.
BRIEF SUMMARY OF THE DISCLOSED APPARATUS
This apparatus is a plastic cap which initially serves as a thread protector for pipe. At the time of pipe installation, the present invention is left on the pipe with a sleeve portion of sufficient length telescoping over the exposed male threads of a threaded pipe. Initially, the protector covers the pipe end to function as a cap. The protective cap is placed over the end of the pipe indefinitely until such time as the pipe is installed in a plumbing system. At that time, the end of the cap can be punched out. This defines an upstanding, exposed shoulder on the exterior. The shoulder is abutted against a coupling to position the sleeve portion over the threads exposed to atmosphere beyond the coupling. This permits the device to be converted to a corrosion protective device at the time the pipe is threaded to a coupling. In conjunction with grease, silicon or other sealants, a corrosion-proof fitting is then installed, and al the threads and coupling face is covered to thereby assure protection against corrosion arising from inclement weather and chemicals in the atmosphere.
DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features, advantages and objects of the present invention are attained and can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings.
It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.
FIG. 1 shows the thread protector cap of the present disclosure positioned over a set of threads on a pipe, and further illustrates a central portion which is defined by a circular internal groove so that the cap can be punched out, thereby defining a sleeve which covers the threads; and
FIG. 2 shows the thread protector of FIG. 1 after the central cap has been removed wherein a coupling has pushed the thread protector on the pipe to assure protection of all portions of the threads, both those covered by the coupling, and those which are exposed on the exterior of the pipe.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Attention is first directed to FIG. 1 of the drawings where the improved thread protector of the present disclosure is identified by the numeral 10. It is placed on a pipe 12 is threaded with male threads at 14. The pipe may be wholly coated, wholly bare or both. The threads terminate at a last thread 16. This is sometimes known as the "last scratch" referring to the fact that it is an area or region of weakness in the pipe and is particularly susceptible to wear, corrosion or mechanical stress. The last scratch region at 16 may or may not be protected when manufactured. It may be exposed bare metal; it may be a regular or tapered thread, it is, generally, a region of weakness. Depending on the conditions and passage of time, this region will likely be the weakest region of the plumbing system when the pipe 12 is assembled in a piping system.
Typically, the pipe 12 will be in the range of about 1/8" to about six inches in nominal diameter. These are the National Standard pipe sizes which are typically installed in single-family residences, apartment complexes, office buildings, industry and similar locations. It is particularly intended that the present apparatus be used with threaded pipe which may be cut and threaded at the plant after manufacture or threaded prior to installation. The pipe 12 is thus described as a mass manufactured pipe where the threads and exterior may or may not be protected with a coating.
The thread protector of this disclosure incorporates a sleeve portion 20. The sleeve portion 20 defines a right cylinder construction. It has sufficient length to cover the threads and a portion of the unthreaded pipe body, and has an internal surface that fits snug over the threads and pipe body. It is not essential that the threads "take a bite" or cut into the inner wall of the sleeve 20.
The sleeve terminates at an upstanding circular shoulder or lip 22. This fully encircles the sleeve portion 20. The shoulder 22 defines an abutting face at 24. The face 24 can be in a commom plane transverse to the center line of the pipe 12 and the thread protector 10. It can also be somewhat sloping or constructed with a small to medium size semicircular bead. It is helpful that the face 24 on the shoulder have a region of contact for cooperation with the pipe coupling as will be described in FIG. 2.
Around the interior of the sleeve 20, a recessed groove 28 is formed adjacent to the sleeve so that a very thin web or membrane is defined. The groove depth and webbing remaining can vary even to the point of forming spaced perforations in a circle. There is a central cap 30 in the form of a circular disc. At the time of manufacture, it is integral with the remainder of the structure which is ideally made by injection molding techniques. However, the cap 30 can be removed by punching out the cap 30. This breaks the cap free at the groove 28. The groove 28 is thus sufficiently deep that it leaves a thin web ranging from about 0.001 to about 0.015 inches thickness. This range can differ depending on the nature of the material used to form the thread protector 10. It is important however to note that the central cap can be removed simply by striking or punching with a mallet, hammer or other blunt instrument at the cap portion 30. This procedure can be used to break the cap free at the groove 28. When this is done, it leaves the sleeve open to telescope further along the pipe 12.
The device of the present disclosure is installed by finger pressure. It is positioned on the end of the pipe until the cap 30 abuts against the end of the pipe. At this time, it will cover most of the threads 14. Moreover, it is held on by friction in view of the relatively close manufacturing tolerance. To the measure that pipe is not perfectly round, the device of this disclosure is deformable. The preferred deformable material enables the sleeve to accommodate less than a perfect circle. An exemplary material is a low density polyethylene but alternate materials can be used. Pliability is desirable so the sleeve can flex and stretch; there is a hoop load where an interferance fit is encountered. The thickness of the wall of the sleeve 20 typically can vary up to about 0.031 or 0.312 inches depending on scale factors and the choice of material. As mentioned before, the face 24 can be planar, tapered, or constructed with a bead to improve contact and sealing.
Attention is now directed to FIG. 2 of the drawings where the pipe 12 and coupling face is fully protected after installation of a pipe coupling 40. The term coupling refers also to a tee, elbow or any other threaded device which engages the male threads on the pipe 12. At this stage, the pipe 12 has been threaded to a coupling 40 for assembly in a plumbing system. The coupling has an abutting end face which contacts the face 24 adjacent to the surrounding shoulder 22. Moreover, the coupling threads up over most but not all of the threads 14. It is not uncommon to leave two or three of the threads exposed. The present invention 10 is pushed onto the pipe. It slides along the pipe in telescoping fashion. It abuts the end of the pipe coupling 40 and extends over the threads to protect the threads against corrosion. Moreover, at the time of installation, a grease, lubricant or other sealant is placed on the threads and pipe surface. When the coupling is threaded to the pipe, it pushes some of the grease or lubricant along the threads. It is convenient to smear an excess quantity of sealant or lubricant on the threads prior to coupling engagement, leaving some under the sleeve 20 even after the sleeve 20 is moved further along the pipe. This leaves a coating of sealant or lubricant under the sleeve 20 and especially in the region of the threads. This typically will cover all the threads with the sealant. Moreover, the sleeve extends over the threads. The annular space between the sleeve 20 and the pipe 12 is thus sealed with the sealant or lubricant, and prevent capillary fluid flow between the protector and the threads. If desired, sufficient sealant can be placed underneath the sleeve 20 and in the region of the coupling that the end face of the shoulder 22 is also covered. It is very helpful to provide complete sealing against the external atmosphere so that the region of the threads and especially the last scratch thread 16 is protected. In general terms, a sealing material under the sleeve enhances performance, particularly by excluding atmospheric exposure and also preventing water flow. Water, normally mixed with various materials, can flow due to capillary movement into and along the threads, increasing rust, corrosion and erosion.
The arrangement of FIG. 2 is achieved in relatively quick order. While the pipe 12 may be stored for weeks or months, and such storage is assisted by placing the thread protector 10 over the end of the pipe (see FIG. 1), the thread protector 10 is quickly converted to the form shown in FIG. 1. Conveniently, it is removed from the end of the pipe, and the cap 30 is punched out quickly. Then, the device is moved beyond the threads. Also, the pipe threads are painted or smeared with the sealant or lubricant. As always, the coupling 40 is joined to the threads 14 in the conventional manner. As it threads up to the final torque, the shoulder of the coupling pushes the present apparatus further along the pipe. It is desirable to leave the sleeve 20 in the location shown in FIG. 2. Typically, the present apparatus does not interfere with installation of the pipe and threaded coupling in the pipe system.
When the threaded connection is complete between the pipe 12 and the coupling 40, the thread protector 10 of the present disclosure is in the position illustrated. All the threads are enclosed and the coupling face is protected. Thus the connection is protected from exposure to detrimental environment by the overcovering thread protector 10 of this disclosure. It assures a high measure of protection. It is far better than merely using protective tape in the pipe joint.
The present apparatus is a device which can be installed and left permanently at a threaded joint in a pipe system. This permits the device to protect the threaded joint indefinitely, far greater than would be obtained with an exposed connection or with other protective devices. Moreover, this protective device 10 is relatively inexpensive in cost and can be manufactured in great quantity to enable an inexpensive corrosion protection system for a completed plumbing system whether indoors or outdoors, whether above ground or below ground. An added benefit is color coding (cosmetically attractive) the sleeve to indicate a particular fluid in the pipe, e.g., black for water, red for gas, etc.
While the foregoing is directed to the preferred embodiment, the scope thereof is determined by the claims which follow: | 4y
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RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 09/292,792, filed Apr. 14, 1999, which is a continuation-in-part of U.S. patent application Ser. No. 09/053,958, filed Apr. 2, 1998. The contents of the above-identified patent applications are hereby incorporated by reference as if fully disclosed herein.
FIELD OF THE INVENTION
[0002] This invention relates to the general field of adhesive patches, specifically, to a patch assembly having a device retaining housing, and more specifically, for retaining a radio transmitter or other device securely to a live animal. This application, thus, describes a composite textile fabric patch assembly having a pouch-type housing disposed thereon, capable of securely housing a radio transmitter or the like; said patch being detachably and/or semi-permanently mounted to the animal via pre-applied, pressure sensitive adhesive.
BACKGROUND AND PRIOR ART
[0003] It is not uncommon to monitor via radio frequency and the like, not only humans but non-human animals, for a number of reasons. For example, non-human animals are monitored for breeding status and humans are monitored for birthing status. This invention is generally directed to and discussed in terms of the animal husbandry industry for ease of understanding, but is not limited or intended to be limited to such.
[0004] A current standard for ensuring breed backs and the like in the cattle industry is the use of artificial insemination (AI) of cows. In order to achieve a high success rate using AI, it is necessary to inseminate the cow during standing heat. Generally, cows are classified as in standing heat and ready for breeding when they submit to being mounted by other cows. One way of determining a standing heat is to have ranch hands, in shifts, observe the herd, pull the cows that appear to be in standing heat and inseminate them. In recent years, technology has provided alternatives to reliance on the human eye for 24-hour observation, for example, the HeatWatch® system (U.S. Pat. No. 5,542,431 to Starzl et al.). This alternative includes the transfer of pertinent information via radio frequency (RF) broadcast from individual cows to a remote location for evaluation and action thereon. One aspect of the system is the attachment of a radio frequency transmitter to the tailhead of each cow. Attachment of this and/or other apparatuses to the tail-heads of cows has been achieved in the past with crude patches that are cemented to a cow with what is generally referred to as livestock glue.
[0005] In their simplest form, prior art patch systems comprise absorbent patches of woven or non-woven synthetic or natural fibers affixed directly to an adhesive tape or placed on a section of the animal previously coated with standard cement. Neither the tape nor the cement adheres well to flexible, hair-growing human or non-human animal skin, particularly in the presence of water, perspiration, or the like. Further, adhesives and tapes can be irritating to skin due to their complete occlusion of oxygen or, alternatively, due to gapping such that the patch system is non-occlusive and falls off the animal.
[0006] In an attempt to provide a superior patch system, prior art has been developed that includes various types of housings and adhesives. U.S. Pat. No. 4,450,844 to Quisno, entitled PATCH SYSTEM FOR USE ON THE SKIN, is directed to a patch system for use on skin. More specifically, a patch having a housing used on human or animal skin for predictive or diagnostic testing or dermal drug delivery and having adhesive coated tape by which it is attached to skin.
[0007] U.S. Pat. No. 4,911,156 to Libertucci, entitled ELASTIC LEG WRAP FOR HORSES, is directed to improved horse leg wraps employing elastic strips interspersed with nylon webbing. Said wrap is significantly lighter than prior art when saturated and resists sliding off of a live animal.
[0008] Next, a METHOD AND SUBSTANCE FOR THE DETECTION OF COWS IN ESTRUS is disclosed in U.S. Pat. No. 4,696,258 to Magrath et al. Microencapsulated substances for detecting standing heat without the use of patches are described and reference the prior use of inferior fabric patches cemented to the rumps of cows.
[0009] The Herriott patent, U.S. Pat. No. 5,566,679 entitled METHODS FOR MANAGING THE REPRODUCTIVE STATUS OF AN ANIMAL USING COLOR HEAT
[0010] MOUNT DETECTORS is directed to a detection patch that is cemented to a cow's back or tailhead. Said detection patch contains chemicals within pressure responsive receptacles that produce a chemiluminescent reaction when activated.
[0011] U.S. Pat. No. 846,106 to Leonardo, entitled METHOD AND APPARATUS FOR DETECTING STANDING HEAT IN CATTLE, is an apparatus adapted to be adhered by adhesive to the base of the tail of a cow. A salient feature of the invention is the provision of a sleeve adapted to retain the assembly of the modular housing and the switch, and to secure the assembly to a cow with an acceptable livestock adhesive. The sleeve is made of plastic layers secured to a polyester backing, and joined to a base sheet of nylon mesh material via perimeter stitching. For attachment to the cow, the nylon base sheet becomes enmeshed in the livestock adhesive applied to the cow.
[0012] The most relevant prior art, describing two estrus detection systems using cemented patches, includes a CATTLE STANDING HEAT DETECTOR disclosed in U.S. Pat. No. 3,158,134 to Larson and a METHOD AND DEVICE FOR DETECTING PERIOD OF HEAT IN COWS as described in U.S. Pat. No. 3,076,431 to Rule et al. Larson discloses a patch base portion having upper and lower surfaces and a housing assembly disposed on one of those surfaces. Said patch is cemented in place on a cow. Larson does not disclose the pre-application of adhesive to the patch base surface opposite the housing assembly. Rule et al. disclose the use of non-setting type adhesive or cement for patch application to a live animal. Non-setting adhesives, however, are inappropriate for extended periods of attachment. Shortcomings found in the prior art include, for example, the inability to retain a patch assembly on an animal for a specified and/or extended period of time, and difficulty of application of patch assemblies. Further, current patch assembly adhesives pull out hair, create skin irritations and allow microbial growth thereunder.
[0013] The present invention overcomes these drawbacks by providing a self-adhesive patch adapted for semi-permanent attachment to living human and non-human animals. The assembly of the instant invention is highly suitable for the above-stated purposes as it is made from laminated elastic textile fabric having flexible and breathable characteristics, for example, Goretex® and Darlexx®, and has factory-applied (preapplied), quick-setting, pressure sensitive adhesive disposed thereon. The patch assembly of the instant invention may be constructed from any number of materials, for example, nylon, canvas, fabric or other similar materials or combinations of such materials.
[0014] In the preferred embodiment, a commercially available, composite textile fabric combining two or more materials having different, yet essential, characteristics is employed; in combination, each material retains its identity while contributing necessary characteristics, such as flexibility and breathability, to the textile as a whole. More specifically, said composite textile fabrics may be constructed from synthetic fibers and/or filaments and are generally useful in the industrial arts. Additional examples of textiles include Lycra®, Nylon®, Dacron® and Orlon®.
[0015] While prior art is suitable for short term patch assembly attachment, notwithstanding skin irritations and the like, none of the prior art can easily and quickly be applied to a live animal, nor does it provide the necessary adhesive bond strength. The present invention provides a pressure sensitive adhesive formulated to possess a quick setting time, having superior bond strength, and in turn, superior attachment and extended retention of patch assemblies to live animals. This invention, thus, provides a patch assembly having a device retaining housing, said assembly adapted for simple, clean attachment to a live animal and possessing an extended shelf-life prior to use obviating the necessity to store and/or apply adhesives to either the animal or the patch.
SUMMARY OF THE INVENTION
[0016] This invention is based on a novel concept for the attachment of patch assemblies to live animals, for example, patches having device retaining housings, e.g., pockets for safely retaining radio transmitters.
[0017] The present invention, when practiced as disclosed herein, provides a novel patch assembly adapted to securely adhere to human and non-human animals for lengthy periods. Adhesives employed herewith are applicable to all patch assemblies for semi-permanent attachment to non-human animals, as well as patch assembly attachment to human skin. The instant invention, thus, is useful for semi-permanent attachment of a device to the skin of a living animal, but is not intended to be limited to this use.
[0018] In its broadest terms, the patch assembly disclosed herein is comprised of a base portion having a device retaining housing mounted thereon, and having pressure sensitive adhesive pre-applied to the opposite surface of said base portion. More specifically, the instant invention comprises a patch assembly constructed of composite textile fabric having at least the characteristics of flexibility and breathability, adapted for easy and neat application to a living animal's tailhead, or other body part. That application is accomplished by removing release paper covering the adhesive, positioning the patch assembly and applying pressure.
[0019] Accordingly, it is an object of the invention to effectively reduce labor, skill and mess in the application of patch assemblies to live animals. That is, adapt said patch assembly for easy, clean manipulation. An additional object of the present invention is to provide patch assemblies with pressure sensitive adhesive having sufficient bond strength to remain in place for extended periods. Further, the patch assembly of the present invention is more aesthetically pleasing in appearance than that of the prior art patch assemblies.
[0020] The instant invention works well, even in the presence of moisture or movement. Said composite materials include, for example, elastomers, rubbers, polymers, plastics and derivatives thereof. The patch assembly of the present invention has numerous applications, however, all embodiments of the instant invention include the same general methodologies, objects and elements: patch assemblies, including a device retaining housing, having pressure sensitive adhesive disposed thereon for mounting on a live animal, and may further comprise certain customizing features and specifications. The patch assembly of the present invention has numerous applications and is suitable for use both with humans and nonhuman animals.
[0021] Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying figures, that illustrate by way of example, the principles of the instant invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] [0022]FIG. 1 is an isometric view of the preferred embodiment of the patch assembly;
[0023] [0023]FIGS. 2 a , 2 b and 2 c are exploded views of the housing assembly; depicting the individual parts thereof and their relationship to one another. FIG. 2 a illustrates the upper portion of the device retaining housing assembly, and FIG. 2 b , the lower portion of the housing assembly. FIG. 2 c depicts the engagement of the upper and lower portions of the housing assembly having a device retained therein.
[0024] [0024]FIG. 3 depicts a lateral cross-sectional view of the patch assembly;
[0025] [0025]FIG. 4 shows the surface of the composite patch section of the patch assembly having pressure sensitive adhesive disposed thereon in a pattern facilitating the flexibility and breathability of the patch assembly.
[0026] [0026]FIG. 5 shows the surface of the composite patch section of the patch assembly having pressure sensitive adhesive disposed thereon, depicting an alternate adhesive pattern shown to facilitate the flexibility and breathability of the patch assembly.
[0027] [0027]FIG. 6 shows the surface of the composite patch section of the patch assembly having pressure sensitive adhesive disposed thereon in yet another useful pattern.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0028] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. The present invention provides a patch system useful for easy semi-permanent attachment to the skin of a human or non-human animal subject, as well as retaining a device within a housing mounted thereon. It is recognized by those skilled in the art that a broad range of patch assemblies and adhesive formulations may be practiced in accordance with the presently disclosed invention.
[0029] The concept of a factory-applied “peel and stick” adhesive patches to retain a device on an animal, for example, the tail-head of a cow, responds to industry need. In current use are cloth or plastic patches that are glued to the tail-head of a cow using non-setting, solvent-based “sale-tag adhesive” which is dispensed from a tube equipped with a nozzle. This patch adhesive system has proven to be reasonably satisfactory in current applications throughout the U.S. and in several foreign countries. However, this method is messy, time-consuming, and requires reasonably careful and skilled application to achieve the required retention period. That is, the amount of time the patch is retained on the animal without reapplication. Even then, in high temperatures or when significant moisture is present, retention is a problem.
[0030] Originally, patches employed, for example in conjunction with Heat Watch® (DDx, Inc., Denver, Colo.) were constructed of burlap fabric which fell apart; especially under conditions of excessive moisture. The next generation of patches were constructed of polyester mesh with pouches produced from Cordura® yarn, or the like. Since conception, several types of adhesives and many patch materials have been tried. Specifically, latex-based adhesives were tried and rejected due to long curing time. Several hot-melt or pressure-sensitive formulations were tried and rejected due to lack of bond strength.
[0031] With the instant invention, a number of individual adhesives and combinations of factory-applied hot-melt adhesive and spray-on solvent-based adhesive are employed with patches constructed of laminated elastic textile fabrics. The present invention is directed to a patch assembly intended to overcome the deficiencies of prior art patch assemblies. This is accomplished by novel means of patch attachment to a live animal and by virtue of the fact that the assembly is made of breathable and flexible material, on which quick-setting, pressure sensitive adhesive has been applied, the combination of which facilitates the extended retention thereof. Moreover, ancillary methods of retention are included herein, for example, hog ring attachments and tail-loops. The present invention provides a patch assembly having quick-setting, pressure sensitive adhesive with superior bond strength on one surface and a device retaining housing on the opposite surface thereof, useful for attachment to a live animal.
[0032] Referring first to FIG. 1, the details of the basic structure of the preferred embodiment of the invention include two major portions: a patch assembly 5 , including a device retaining housing 15 mounted on a patch base 10 ; and, a peel-and-stick pressure sensitive adhesive 50 . In a preferred embodiment of the present invention, the patch base 10 is generally rectangular in shape having a device housing 15 centrally disposed on its surface or, alternatively, integrally formed and extending therefrom, and a preapplied pressure sensitive adhesive 50 on the opposite surface from said housing 15 . This patch assembly 5 retains within its housing 15 a radio transmitter or other device securely on a cow or other animal. The patch base 10 is comprised of composite textile fabric, for example, fabric with polytetrafluoroethylene laminate, or like laminated elastic textile fabrics having knit flexible backings; said assembly further comprises a housing 15 constructed of synthetic yarns, for example, Cordura® or other like material, generally centered on the patch base 10 . Said housing 15 may be sewn onto the patch base 10 or integrally formed therefrom as discussed supra. Also, optionally included in the patch assembly 5 are ancillary retention features. For example, a tail strap 25 which is either taped onto the animals's tail or fastened with a wire or cord through a grommet 20 in the tail strap and a hog ring inserted through the animal's skin. These features may steady the patch assembly 5 and, in fact, maintain it on the animal in the event the assembly becomes dislodged from the animal. The tail strap 25 retains the patch on the animal if it comes loose from its glued-on position.
[0033] The base of the patch lends itself well to being composed of a composite fabric material having the characteristics of flexibility and breathableness. For example, any number of textiles in the laminated elastic textile fabric group may be used. As a non-limiting example, excellent results have been achieved with the composite material sold under the trademarks Gore-tex® and Darlexx®.
[0034] The preferred embodiment of the housing assembly 15 , as shown in FIGS. 2 a , 2 b , and 2 c , is comprised of an upper portion 30 , a lower portion 35 and at least one fastener 40 , for example, the hook-and-loop type fastener marketed under the name Velcro®. The upper portion 30 having a generally rhomboid shape presents an inverted rhomboid-shaped, planar flange 31 from its shorter, parallel side; disposed and mounted in a generally central area of the flange, on the internal surface, is a segment of hook-and-loop fastener 40 , either hook or loop portion. See FIG. 2 a . A generally rectangular-shaped piece of fabric having a rhombus-shaped, planar flange 36 extending therefrom, the shorter parallel side integrally formed from the rectangle's short side, forms the lower portion 35 of the housing assembly 15 (FIG. 2 b ); disposed and mounted in a generally central area at the point of flange integration, on the external surface, is a segment of hook-and-loop fastener 40 portion functionally corresponding to that of the upper housing portion 30 . Said flanges 31 , 36 , functionally interfold with one another, one over the other, thereby engaging said fastener segments, closing and sealing the housing 15 from external influences (FIG. 2 c ); said lower flange 36 inserts into the housing 15 and over the device 45 housed therein, said upper flange 31 , in turn, inserting under lower flange 36 , engaging the corresponding hook-and-loop fastener portions 40 .
[0035] [0035]FIG. 3 shows a lateral cross-section of the patch assembly, subsequent to the previously described housing assembly 15 engagement. The three, remaining peripheral edges of both the upper 30 and lower portion 35 of the housing assembly 15 are continuously connected or affixed to one another, for example, by stitching or sealing, so as to define a housing assembly 15 having three closed or sealed peripheral edges and one open peripheral edge for receiving and securely retaining a device. Said unaffixed peripheral edges providing an opening allowing insertion or removal of a device; once a device is placed inside the housing 15 , the opening is sealed as described. Prior to insertion of a device, said housing assembly 15 is mounted in a generally central location on said patch base portion 10 by, for example, cementing or preferably stitching it thereto.
[0036] On the patch base 10 surface opposite the housing assembly 15 is adhesive 50 for use in application of the patch assembly 5 to an animal. See FIG. 4. The adhesive used is, in general, a solvent-based hot-melt pressure-sensitive type adhesive such as Bostik H/M 9068 (Bostik Inc., Middleton, Mass.). The adhesive is applied in a specific pattern by an electronic glue dispensing device, specifically adapted for such application, by manipulating dispensing nozzles via computer-controlled positioning devices. The application pattern is closely controlled and may be varied, through computer programming, to produce any number of alternative patterns altering the percentage of area of adhesive versus the percentage of area enabling air flow, see, for examples, FIGS. 4, 5 and 6 . By creating a pattern of adhesive, as opposed to a single, solid layer of adhesive, air and water vapor are able to migrate to and from the skin facilitating patch retention. Moreover, the elastically deformable patch fabric allows water vapor to pass through while blocking the passage of fluid to the skin surface. That is, the patch assembly allows air to reach the skin surface, while shedding fluid therefrom and/or enabling the transfer of vapors away therefrom.
[0037] Prior to use, the pressure sensitive adhesive may be protected with a removable release paper facilitating storage and/or transport. Release paper may be of any appropriate type, suitable or adapted for use with the particular application to which the patch assembly is directed. Generally, papers coated with polyethylene silicone, paraffin wax or aluminum foil provide excellent results. Said configuration insures long-shelf life of the assembly; significantly longer, with or without release paper, than conventional livestock glue preparations. In use, the patch assembly is attached to the animal, for example a cow, by first cleaning the hide of loose hair, dander, dirt and other particles. Then a thin layer of adhesive activator, such as contact type aerosol adhesive, is sprayed evenly onto the tailhead to provide a base for the patch and to activate the adhesive on the patch. An optional coat of activator may be sprayed directly onto the patch itself. Allow the activator to set for approximately 1 minute—that is, dry until not sticky to the touch. If not already removed, remove the release paper from the patch and position and apply the patch to the cow, pressing it into place using either finger pressure or a small roller. Finally, attach tail strap and hog ring in a standard method.
[0038] It is apparent that the present invention provides a method and means for mounting and easily retaining a radio transmitter or other device to a live animal. Furthermore, the instant invention may clearly be practiced in conjunction with any type of device to be retained on an animal, i.e., identification, location, bodily functions. While specific embodiments of the invention have been illustrated and described herein, these should not be construed as limitations on the scope of the invention, but rather an exemplification of the preferred embodiments thereof. Numerous variations are possible and will occur to those skilled in the art. It is therefore to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit and scope of the invention. | 4y
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TECHNICAL FIELD
[0001] The present invention relates to an exhaust gas purifying device for an internal combustion engine that temporarily adsorbs NOx in an exhaust gas of the internal combustion engine and purifies the exhaust gas by reducing the adsorbed NOx.
BACKGROUND OF THE INVENTION
[0002] In lean-burn internal combustion engines (diesel engines, for example), a lean NOx catalyst (hereinafter referred to as LNC) may be fitted in an exhaust passage to clean the exhaust gas by reducing NOx (nitrogen oxides) in the exhaust gas. This LNC functions to trap (more specifically, adsorb) NOx when the air fuel ratio of the exhaust gas (referred to as exhaust A/F hereinafter) is higher than a prescribed level (referred to as a “lean” condition hereinafter), and reduce the adsorbed NOx to a harmless form when the exhaust A/F is lower than a prescribed level (referred to as a “rich” condition hereinafter).
[0003] The exhaust gas purifying capability of the LNC can change depending on operating conditions of the internal combustion engine and it is known, for example, that a phenomenon called “NOx slip” can sometimes happen in that part of the NOx adsorbed by the LNC is released without being reduced during the reduction process.
[0004] In order to avoid such a phenomenon, Japanese Patent Application Publication No. 2006-214320 has proposed an internal combustion engine control that prevents the lean operation when an LNC temperature is below a prescribed temperature and a load of the internal combustion engine is higher than a prescribed value.
[0005] On the other hand, because the exhaust gas purifying capability of the LNC tends to diminish as an amount of adsorbed NOx increases, a so-called “rich spike control” is conducted in that the exhaust A/F is made into a rich atmosphere intermittently at appropriate times in order to reduce the NOx adsorbed by the LNC. In this regard, it has been also found that though not as good as the LNC, a three-way catalyst (TWC) also has a similar NOx processing ability.
[0006] However, the technique described in JPA Publication No. 2006-214320 needs to conduct stoichiometric (abbreviated to “stoic” hereinafter) operation until the LNC temperature reaches an activation temperature, which is 200° C. or higher, for example, and this is undesirable in view of fuel consumption efficiency.
BRIEF SUMMARY OF THE INVENTION
[0007] The present invention is made to solve such prior art problems, and a primary object of the present invention is to provide an improved exhaust gas purifying device for an internal combustion engine that can achieve higher NOx decreasing ability in an inactive state of an LNC.
[0008] To achieve such an object, the present invention provides an exhaust gas purifying device for an internal combustion engine, comprising: a first catalyst (TWC 7 , for example) having a reducing ability; a second catalyst (LNC 9 , for example) provided downstream of the first catalyst, the second catalyst is adapted to trap NOx in a lean condition of air fuel ratio of an exhaust gas and reduce the trapped NOx in a rich condition of air fuel ratio of the exhaust gas; and an exhaust air fuel ratio control means for controlling an exhaust air fuel ratio to decrease the NOx in the first and second catalysts, wherein the exhaust air fuel ratio control means conducts NOx decreasing control suitable for the first catalyst when the second catalyst is in an inactive state and the first catalyst is in an active state, and wherein the exhaust air fuel ratio control means conducts NOx decreasing control suitable for the second catalyst after the second catalyst is activated.
[0009] According to such a structure, in an operating state where the second catalyst temperature has not reached the activation temperature and hence the exhaust emission could be deteriorated, a NOx decreasing control suitable for the first catalyst, which is positioned upstream of the second catalyst and hence can reach its activation temperature earlier than the second catalyst, is conducted to effectively decrease NOx.
[0010] Preferably, the NOx decreasing control suitable for the first catalyst can be selected from a rich spike control, a continuous stoic control and a weak rich control. Typically, in an operating state where the second catalyst temperature has not reached the activation temperature, a rich spike mode control suitable for the first catalyst is conducted to decrease NOx if the first catalyst temperature has reached the activation temperature and the load is low, and this contributes to economic fuel consumption. On the other hand, if the load is high and the first catalyst cannot adsorb NOx, the exhaust air fuel ratio (A/F) is controlled to be continuously “stoic” or weak rich to reduce NOx into a harmless form. Thus, the present invention is quite effective in achieving both of improvement of exhaust emission quality and favorable fuel economy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Now the present invention is described in the following with reference to the appended drawings, in which:
[0012] FIG. 1 is an overall structural view of an internal combustion engine to which the present invention is applied;
[0013] FIG. 2 is a block diagram of a control device to which the present invention is applied;
[0014] FIG. 3 is a flowchart regarding mode switching control;
[0015] FIG. 4 is a graph schematically showing the mode switch timing;
[0016] FIG. 5 is a flowchart regarding rich spike control; and
[0017] FIG. 6 is an explanatory view regarding a judgment value for rich spike control performing region.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] FIG. 1 is a basic structural view of an internal combustion engine E to which the present invention is applied. The mechanical structure of this internal combustion engine (diesel engine) E is no different from a conventional one, and the engine E comprises a turbocharger 1 equipped with a variable boost pressure mechanism. An intake passage 2 is connected to a compressor side of the turbocharger 1 and an exhaust passage 3 is connected to a turbine side of the turbocharger 1 . An air cleaner 4 is connected to an upstream end of the intake passage 2 , and an intake control valve 5 for controlling a flow rate of fresh air flowing into a combustion chamber and a swirl control valve 6 for restricting a cross-section of the flow passage to increase the air flow velocity in a low rotational speed/low load operation region are provided at appropriate positions in the intake passage 2 . Further, connected on a downstream side of the exhaust passage with respect to the turbocharger 1 is connected an exhaust gas purifying device 10 , which comprises: a TWC 7 (first catalyst) for oxidizing HC and CO as well as reducing NOx in the exhaust gas under a “stoic” atmosphere; a filter (DPF) 8 for removing particulate matter (PM) such as soot; and an LNC 9 (second catalyst) for trapping (more specifically, adsorbing) NOx in the exhaust gas when the oxygen level is high (“lean” condition) and reducing the adsorbed NOx when the oxygen level is low (“rich” condition), where the TWC 7 , filter 8 and LNC 9 are arranged in this order from upstream along the flow of exhaust gas.
[0019] The swirl control valve 6 and a part of the exhaust passage 3 near the exit of the combustion chamber are connected to each other via an exhaust gas recirculating (hereinafter referred to as EGR) passage 11 . This EGR passage 11 comprises a cooler passage 11 a and a bypass passage 11 b which are bifurcated at a switching valve 12 , and an EGR control valve 13 is provided at a junction of the passages 11 a and 11 b for controlling an EGR flow rate toward the combustion chamber.
[0020] A fuel injection valve 14 is provided to a cylinder head of the internal combustion engine E such that an end of the fuel injection valve 14 extends into the combustion chamber. The fuel injection valve 14 is connected to a common rail 15 containing fuel at a prescribed high pressure, and the common rail 15 is connected to a fuel pump 17 driven by a crankshaft to pump up fuel from a fuel tank 16 .
[0021] The variable boost pressure mechanism 19 for the turbocharger 1 , the intake control valve 5 , EGR passage switching valve 12 , EGR control valve 13 , fuel injection valve 14 , fuel pump 17 and so on are configured to operate according to control signals from an electronic control unit (ECU) 18 (see FIG. 2 ).
[0022] As shown in FIG. 2 , the ECU 18 in turn receives signals from an intake valve opening sensor 20 , crankshaft rotational speed sensor 21 , intake flow rate sensor 22 , boost pressure sensor 23 , EGR valve opening sensor 24 , common rail pressure sensor 25 , accelerator pedal sensor 26 , O 2 sensors 27 U and 27 L, NOx sensors 28 U and 28 L, TWC temperature sensor 29 , LNC temperature sensor 30 and so on which are provided in appropriate parts of the internal combustion engine E.
[0023] A memory for ECU 18 stores a map setting target values of various controlled quantities such as optimum fuel injection obtained beforehand with respect to crankshaft rotational speed and torque demand (accelerator pedal displacement) which is typically determined experimentally so that the various control quantities may be optimally controlled and an optimum combustion state may be achieved under all load conditions of the internal combustion engine E.
[0024] Next, with reference to FIG. 3 , an explanation is made to selection control of a rich spike mode. First of all, an LNC temperature is detected and a judgment is made on whether or not the temperature has reached a prescribed activation temperature which is 150-200° C., for example (step 1 ). When it is determined that the LNC temperature has reached the activation temperature (“Yes” in step 1 ), a rich spike mode suitable for the LNC 9 is conducted (step 2 ).
[0025] When it is found that the LNC temperature has not reached the activation temperature (“No” in step 1 ), a judgment is made on whether or not the TWC 7 has reached a prescribed activation temperature, which is 200° C., for example (step 3 ). When it is found that the TWC 7 has not reached the activation temperature (“No” in step 3 ), it is judged that a condition for conducting the rich spike mode has not established, and the first cycle of the process is ended.
[0026] When it is found in step 3 that the TWC 7 has reached the activation temperature (“Yes” in step 3 ), a search is made in a load determination map (not shown in the drawings) set with respect to the crankshaft rotational speed and torque demand, and a judgment is made on whether the current state is in a prescribed high load region (step 4 ). If it is found that the load is below a prescribed value (“No” in step 4 ), a rich spike mode suitable for TWC 7 is conducted (step 5 ), while if it is found that the load is greater than the prescribed value (“Yes” in step 4 ), a continuous stoichiometric mode (stoic mode) or a weak rich mode is conducted (step 6 ).
[0027] Because the TWC 7 is disposed more upstream of the exhaust passage or closer to the combustion chamber than the LNC 9 , the temperature of the TWC 7 rises faster than the LNC 9 . FIG. 4 shows such a situation in a time sequence. As shown, when the TWC reaches the activation temperature, the rich control suitable for the TWC 7 is conducted until the LNC 9 reaches the activation temperature, and when the LNC 9 reaches the activation temperature, the rich control suitable for the LNC 9 is conducted.
[0028] Next, an explanation is made to the control in the rich spike mode with respect to FIG. 5 . The rich spike mode is for releasing and reducing NOx adsorbed by TWC 7 or LNC 9 during the lean combustion operation, and conducted in response to an increase in the amount of fuel injection (main injection and post injection) or decrease in an amount of air intake in the fuel injection valve 14 , which can result from the control of turbocharger 1 , intake control valve 5 , swirl control valve 6 and/or EGR control valve 13 .
[0029] First, a judgment is made on whether a “rich” timer for counting an execution time of the rich spike mode has finished time counting (i.e., the timer indicates count 0) or not (step 11 ). When the count value of the rich timer is zero, in other words, when it is determined that the rich spike mode has finished (“Yes” in step 11 ), a search is made in a NOx discharge map (not shown in the drawings) which is adapted to be accessed by using the crankshaft rotational speed and the torque demand as an address, and NOx discharge corresponding to the current operation state is computed (step 12 ). This map is adapted to provide a higher value for a higher crankshaft rotational speed and for a higher torque demand.
[0030] Then, the NOx discharge obtained in step 12 is added to a previously obtained NOx discharge accumulation to calculate an updated (current) NOx discharge accumulation (step 13 ). The NOx discharge accumulation indicates a total amount of NOx adsorbed by the TWC 7 or the LNC 9 .
[0031] Subsequently, a judgment is made on whether the displacement of the accelerator pedal is zero (fully closed) or not (step 14 ). If it is found that the accelerator pedal is not being stepped on, i.e., the current state is in a deceleration or idling (“Yes” in step 14 ), it is considered that the condition for conducting the rich spike mode has not established, and the first cycle of the process is ended. When it is found in step 14 that the accelerator pedal is being stepped on (“No” in step 14 ), then a judgment is made on whether the NOx discharge accumulation obtained in step 13 exceeds a prescribed threshold value or not (step 15 ).
[0032] This threshold value is set for both of TWC 7 and LNC 9 , and can be obtained by searching a table configured with respect to the temperature of each catalyst. As shown in FIG. 6 , the threshold value provided by the table is set at a first judgment value for the catalyst temperature below a first prescribed temperature (200° C., for example), set at a second judgment value, which is higher than the first judgment value, for the catalyst temperature higher than a second prescribed temperature, and set at a value on a straight line connecting the first and second judgment values for the catalyst temperature between the first and second prescribed temperatures. This is intended to cope with the tendency that the lower the temperature of TWC 7 or LNC 9 is or the more the amount of adsorption of NOx is, the reduction rate of NOx decreases due to NOx slip.
[0033] When it is determined that the NOx discharge accumulation is below the prescribed threshold value (“No” in step 15 ), it is considered that the amount of adsorption of NOx is not enough and the condition for conducting the rich spike mode has not established, and the first cycle of the process is ended.
[0034] On the other hand, when it is determined that the NOx discharge accumulation exceeds the prescribed threshold value (“Yes” in step 15 ), the rich spike mode is conducted (step 16 ) and the NOx discharge accumulation is reset to zero. At the same time, the rich timer for counting back from a prescribed execution time of rich spike mode (5 sec, for example) is set to start, and the first cycle of the process is ended.
[0035] When it is determined in step 1 that the counting of the rich timer has not finished counting (“No” in step 1 ), in other words, when the rich spike mode is still being conducted, an averaged value of the accelerator pedal displacement is computed and a judgment is made on whether the averaged displacement is substantially zero or not (step 18 ). When it is determined that the averaged value of accelerator pedal displacement is substantially zero (“No” in step 18 ), it is considered that the accelerator pedal has been released during the execution of rich spike mode, and thus the rich spike mode operation is terminated. When it is determined that the averaged value of accelerator pedal displacement is not substantially zero (“Yes” in step 18 ), the rich spike mode operation is continued.
[0036] As described above, when the LNC 9 is inactive and the TWC 7 is active, the rich spike mode, the continuous stoic mode or the weak rich mode is selectively conducted depending on the operational load, and this can allow efficient NOx purification (or decrease) to be achieved by using the TWC 7 even though the LNC 9 is inactive without deteriorating fuel consumption efficiency.
[0037] Although the present invention has been described in terms of preferred embodiments thereof, it is obvious to a person skilled in the art that various alterations and modifications are possible without departing from the scope of the present invention which is set forth in the appended claims.
[0038] The disclosure of the original Japanese patent application (Japanese Patent Application No. 2006-316528 filed on Nov. 24, 2006) on which the Paris Convention priority claim is made for the present application is hereby incorporated by reference in its entirety. | 4y
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FIELD OF THE INVENTION
[0001] The present invention relates to the field of switching regulator and more particularly to smart start-up circuit for switching regulators.
BACKGROUND ART
[0002] Switching regulator is a vitally important device. Switching regulators are building blocks used extensively in power systems, industry, motor, communication, networks, digital systems, consumer electronics, computers, and any other fields that high efficient voltage regulating functions.
[0003] Switching regulators (i.e., DC-TO-DC converters) can provide output voltages which can be less than, greater than, or of opposite polarity to the input voltage. Prior Art FIG. 1 illustrates a basic architecture of a conventional switching regulator 100 . The conventional switching regulator 100 basically consists of an oscillator, a reference circuit 102 , an error amplifier, a modulator including a comparator, resistors, and a control logic circuit. Control technique of switching regulators has typically used two modulators: a pulse-width modulator and a pulse-frequency modulator. The output DC level is sensed through the feedback loop including two resistors. An error amplifier compares two input voltages: the sampled output voltage and the reference voltage. The output of the error amplifier is compared against a periodic ramp generated by the saw tooth oscillator. The pulse-width modulator output passes through the control logic to the power switch. The feedback system regulates the current transfer to maintain a constant output voltage within the load limits. In other words, it insures that the output voltage level reaches the equilibrium. When the output voltage level reaches the equilibrium, V F is equal to V REF , as shown in Prior Art FIG. 1 .
[0004] However, it takes a vast amount of time until the output voltage level reaches the equilibrium from an initial condition after the switching regulator of Prior Art FIG. 1 starts. Therefore, power and time are consumed until the switching regulator's output voltage level reaches the equilibrium. In addition, it takes a long time to simulate and verify the conventional switching regulator 100 before fabrication since its simulation time is absolutely proportional to time that is required the switching regulator's output voltage level to reach the equilibrium. Hence, this long simulation adds additional cost and serious bottleneck to design time-to-market. In other words, the slow start-up of the switching regulator increases design simulation time. For these reasons, the conventional switching regulator 100 of Prior Art FIG. 1 is very inefficient to implement in system-on-chip (SOC) or integrated circuit (IC).
[0005] Thus, what is needed is a fast starting-up switching regulator that can be highly efficiently implemented with a drastic improvement in a very fast start-up time, start-up time controllability, performance, time-to-market, power consumption, power and time management, efficiency, cost, and design time. It is highly desirable to enable all of the switching regulators' output voltage levels to reach the equilibrium immediately for much higher power efficiency or according to schedule. The present invention satisfies these needs by providing five embodiments.
SUMMARY OF THE INVENTION
[0006] The present invention provides five types of the smart start-up circuits for switching regulators. The smart start-up circuits simultaneously enable any switching regulator's output voltage level to reach the equilibrium according to schedule. The basic architecture of the smart start-up circuits consists of a sensor, two stacked PMOS transistors, two stacked NMOS transistors, and a feedback line. The sensor senses a voltage at its input. If the sensing voltage does not reach the expected voltage compared to the midpoint voltage of the sensor, the output voltage of the sensor turns on the corresponding transistor, which provides a current to its output until the output voltage reaches the midpoint voltage. The time to reach the midpoint voltage at the load is simply equal to the charge stored at the load divided by the current, which can be scaled.
[0007] Consequently, all smart start-up circuits provide a significant reduction in the difference between the initial output voltage level and the expected output voltage level in order to overcome serious drawbacks simultaneously. The smart start-up time of the present invention enables all systems to be managed in terms of power, stand-by time, and start-up time. The present invention provides five different embodiments which achieve a drastic improvement in a very fast start-up time, start-up time controllability, performance, time-to-market, power consumption, power and time management, efficiency, cost, and design time.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate five embodiments of the invention and, together with the description, serve to explain the principles of the invention:
[0009] Prior Art FIG. 1 illustrates a block diagram of a conventional switching regulator (i.e., DC-TO-DC converter).
[0010] FIG. 2 illustrates a block diagram of two types of smart start-up circuits for switching regulator in accordance with the present invention.
[0011] FIG. 3 illustrates a circuit diagram of a basic smart start-up circuit according to the present invention.
[0012] FIG. 4 illustrates a circuit diagram of a smart start-up circuit in accordance with the present invention.
[0013] FIG. 5 illustrates a circuit diagram of a dual smart start-up circuit according to the present invention.
[0014] FIG. 6 illustrates a circuit diagram of a p-type smart start-up circuit in accordance with the present invention.
[0015] FIG. 7 illustrates a circuit diagram of a p-type dual smart start-up circuit according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] In the following detailed description of the present invention, five types of the smart start-up circuits, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be obvious to one skilled in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, CMOS digital gates, components, and metal-oxide-semiconductor field-effect transistor (MOSFET) device physics have not been described in detail so as not to unnecessarily obscure aspects of the present invention.
[0017] FIG. 2 illustrates two types of the smart start-up circuits for switching regulators in accordance with the present invention. One type of the smart start-up circuit is applied for switching regulators driving a load 216 connected between V OUT and ground, as seen in the switching regulator system 210 shown in FIG. 2 . The other type of the smart start-up circuit called “p-type smart start-up circuit” is applied for switching regulators driving a load 226 connected between V DD and V OUT , as seen in the switching regulator system 220 shown in FIG. 2 . To reduce the difference between the initial output voltage level and the expected output voltage level of the switching regulator, the output of all the smart start-up circuits is coupled to the output terminal of switching regulators, as shown in FIG. 2 . The switching regulator 212 represents all types of the switching regulators (i.e., DC-TO-DC converter) driving a load 216 connected between V OUT and ground without regard to the types of switching regulators because the applications of the smart start-up circuit 214 are independent of architectures and types of switching regulators. The switching regulator 222 represents all types of the switching regulators (i.e., DC-TO-DC converter) driving a load 226 connected between V DD and V OUT without regard to the types of switching regulators because the applications of the p-type smart start-up circuit 224 are independent of architectures and types of switching regulators. If loads 216 and 226 are multiple-order, then they will be approximated to the first-order load with neglecting resistor and inductor in the load for simplicity.
[0018] FIG. 3 illustrates a basic smart start-up circuit according to the present invention. This basic smart start-up circuit 300 does not have power-down mode in order to show the fundamental concept of the invention clearly. The basic smart start-up circuit 300 is a feedback circuit that consists of lower-voltage sensing inverters 302 and 312 (i.e., an even number of inverters), higher-voltage sensing inverters 304 and 324 (i.e., an even number of inverters), two stacked PMOS transistors 306 and 308 , two stacked NMOS transistors 326 and 328 , and a feedback line 310 . The gate terminal of a PMOS transistor 308 is connected to a proper fixed-bias voltage (not shown) or ground (e.g., “0”, low, etc.). The gate terminal of a NMOS transistor 326 is connected to a proper fixed-bias voltage (not shown) or power supply voltage (e.g., V DD , “1”, high, etc.).
[0019] It is assumed that the output of the basic smart start-up circuit 300 is at ground. Since the first lower-voltage sensing inverter 302 initially senses a voltage less than the lower midpoint voltage of the first lower-voltage sensing inverter 302 , the output voltage of the second lower-voltage sensing inverter 312 is low enough to turn on the PMOS transistor 306 . At the same time, the output voltage of the second higher-voltage sensing inverter 324 is low enough to turn off the NMOS transistor 328 . Thus, the PMOS transistor 306 provides a current (i.e., I P ,) to the output until the output voltage (i.e., V OUT ) goes up to the lower midpoint voltage of the first lower-voltage sensing inverter 302 . The time to reach the lower midpoint voltage at the load connected between V OUT and ground is as follows:
Δ t = V M C P I P
where V M is the lower midpoint voltage determined by the device aspect ratios of the first lower-voltage sensing inverter 302 and C P is the value of the capacitor in the load. Also, assuming that V M is closer to the output voltage level that reaches the equilibrium in switching regulators, the start-up time of the switching regulators is approximately given by
V M C P I P
This start-up time is varied by the current I P depending on the size of the PMOS transistor 306 .
[0020] It is assumed that the output of the basic smart start-up circuit 300 is at power supply. Since the first higher-voltage sensing inverter 304 initially senses a voltage greater than the higher midpoint voltage of the first higher-voltage sensing inverter 304 , the output voltage of the second higher-voltage sensing inverter 324 is high enough to turn on the NMOS transistor 328 . At the same time, the output voltage of the second lower-voltage sensing inverter 312 is high enough to turn off the PMOS transistor 306 . Thus, the NMOS transistor 328 provides a current (i.e., I N ) to the output until the output voltage (i.e., V OUT ) goes down to the higher midpoint voltage of the first higher-voltage sensing inverter 304 . The time to reach the higher midpoint voltage at the load connected between V OUT and power supply is as follows:
Δ t = ( V DD - V M ( H ) ) C P I N
where V M(H) is the higher midpoint voltage determined by the device aspect ratios of the first higher-voltage sensing inverter 304 and C P is the value of the capacitor in the load. Also, assuming that V M(H) is closer to the output voltage level that reaches the equilibrium in switching regulators, the start-up time of the switching regulators is approximately given by
( V DD - V M ( H ) ) C P I N
This start-up time is varied by the current I N depending on the size of the NMOS transistor 328 .
[0021] The midpoint voltage is a voltage where the input voltage and the output voltage of the inverter are equal in the voltage transfer characteristic. At the midpoint voltage, the transistors of the inverter operate in the saturation mode. This midpoint voltage of inverter is expressed as
V DD - V T n - V T P 1 + K n K p + V T n where
K n K p = μ n C OX ( W L ) n μ p C OX ( W L ) p
[0022] In design of the basic smart start-up circuit of FIG. 3 , it is also desirable to use a value for the lower midpoint voltage, V M , less than V OUT ′ and a value for the higher midpoint voltage, V M(H) , greater than V OUT ′. V OUT ′ is the output voltage level that reaches the equilibrium in switching regulators.
[0023] FIG. 4 illustrates a smart start-up circuit 400 according to the present invention. A power-down input voltage, V PD , is defined as the input voltage for power-down mode. The power-down enable system is in power-down mode when V PD is V DD and it is in normal mode when V PD is zero. The smart start-up circuit 400 is a feedback circuit that consists of lower-voltage sensing inverters 402 and 412 (i.e., an even number of inverters), two stacked PMOS transistors 406 and 408 , two stacked NMOS transistors 426 and 428 , a feedback line 410 , and a power-down NMOS transistor 442 . In addition, the gate terminal of a PMOS transistor 408 is connected to a proper fixed-bias voltage (not shown) or ground (e.g., “0”, low, etc.). The gate terminal of a NMOS transistor 426 is connected to a proper fixed-bias voltage (not shown) or power supply voltage (e.g., V DD , “1”, high, etc.). Furthermore, the gate terminal of a NMOS transistor 428 is shorted and thus no current flows into the drains of the NMOS transistors 426 and 428 .
[0024] The circuit mode changes from power-down mode to normal mode in FIG. 4 . Since the first lower-voltage sensing inverter 402 initially senses a voltage less than the lower midpoint voltage of the first lower-voltage sensing inverter 402 , the output voltage of the second lower-voltage sensing inverter 412 is low enough to turn on the PMOS transistor 406 . The PMOS transistor 406 generates a current (i.e., I P ) to the output until the output voltage (i.e., V OUT ) goes up to the lower midpoint voltage of the first lower-voltage sensing inverter 402 . Furthermore, assuming that V M is closer to the output voltage level that reaches the equilibrium in switching regulators, the start-up time of the switching regulators is approximately given by
V M C P I P
Also, V M is the lower midpoint voltage determined by the device aspect ratios of the first lower-voltage sensing inverter 402 and C P is the value of the capacitor in the load. The start-up time is varied by the current I P depending on the size of the PMOS transistor 406 .
[0025] In design of the smart start-up circuit of FIG. 4 , it is also desirable to use a value for the lower midpoint voltage, V M , less than V OUT ′. V OUT ′ is the output voltage level that reaches the equilibrium in switching regulators. The smart start-up circuit 400 is used for all types of switching regulators driving the load connected between V OUT and ground. Since the power-down NMOS transistor 442 is on during power-down mode, it provides an output pull-down path to ground. Thus, V OUT of the smart start-up circuit 400 is zero so that no current flows into the circuits during power-down mode.
[0026] FIG. 5 illustrates a dual smart start-up circuit 500 in accordance with the present invention. The dual smart start-up circuit 500 is a modification of the circuit described in FIG. 4 . The gate terminal of a PMOS transistor 508 is connected to a proper fixed-bias voltage (not shown) or ground (e.g., “0”, low, etc.). The gate terminal of a NMOS transistor 526 is connected to a proper fixed-bias voltage (not shown) or power supply voltage (e.g., V DD , “1”, high, etc.). Furthermore, compared to FIG. 4 , the first difference to note is that the higher-voltage sensing inverters 504 and 524 (i.e., an even number of inverters) are added into FIG. 5 in order to provide the higher-voltage sensing function. The second difference to note is that the output of the second higher-voltage sensing inverter 524 is connected to the gate terminal of a NMOS transistor 528 . Therefore, the dual smart start-up circuit 500 is able to sense the lower-voltage as well as the higher-voltage while the smart start-up circuit 400 is able to sense only the lower-voltage.
[0027] No current flows into the drains of the NMOS transistors 526 and 528 assuming V OUT <V M(H) where V M(H) is the higher midpoint voltage decided by the device aspect ratios of the first higher-voltage sensing inverter 504 . If V OUT is greater than V M(H) , the gate voltage of the NMOS transistor 528 is V DD . As a result, a current flows into the drains of the NMOS transistors 526 and 528 until V OUT goes down to V M(H) .
[0028] In design of the dual smart start-up circuit of FIG. 5 , it is also desirable to use a value for the lower midpoint voltage, V M , less than V OUT ′ and a value for the higher midpoint voltage, V M(H) greater than V OUT ′ . V OUT ′ is the output voltage level that reaches the equilibrium in switching regulators. V M is the lower midpoint voltage decided by the device aspect ratios of the first lower-voltage sensing inverter 502 . The dual smart start-up circuit 500 is used for all types of switching regulators driving the load connected between V OUT and ground. Zero dc volt at V OUT ensures that no current flows into the circuits during power-down mode.
[0029] FIG. 6 illustrates a p-type smart start-up circuit 600 according to the present invention. The power-down input voltage, V PD , is defined as the input voltage for the p-type power-down mode as well as for the power-down mode. The p-type power-down enable system is in power-down mode when V PD is V DD and it is in normal mode when V PD is zero. The p-type smart start-up circuit 600 is a feedback circuit that consists of a higher-voltage sensing inverters 604 and 624 (i.e., an even number of inverters), two stacked PMOS transistors 606 and 608 , two stacked NMOS transistors 626 and 628 , a feedback line 610 , a power-down inverter 614 , and a power-down PMOS transistor 642 . In addition, the gate terminal of a PMOS transistor 608 is connected to a proper fixed-bias voltage (not shown) or ground (e.g., “0”, low, etc.). The gate terminal of a NMOS transistor 626 is connected to a proper fixed-bias voltage (not shown) or power supply voltage (e.g., V DD , “1”, high, etc.). Furthermore, since the PMOS transistor 606 is turned off, no current flows out of the drains of the PMOS transistors 606 and 608 .
[0030] The circuit mode changes from p-type power-down mode to normal mode in FIG. 6 . Since the first higher-voltage sensing inverter 604 initially senses a voltage greater than V M(H) , the output voltage of the second higher-voltage sensing inverter 624 is high enough to turn on the NMOS transistor 628 . V M(H) is the higher midpoint voltage decided by the device aspect ratios of the first higher-voltage sensing inverter 604 . The NMOS transistor 628 generates a current (i.e., I N ) to the output until the output voltage (i.e., V OUT ) goes down to V M(H) . Assuming that V M(H) is closer to the output voltage level that reaches the equilibrium in switching regulators, the start-up time of the switching regulators is approximately given by
( V DD - V M ( H ) ) C P I N
Also, C P is the value of the capacitor in the load. The start-up time is varied by the current I N depending on the size of the NMOS transistor 628 .
[0031] In design of the p-type smart start-up circuit of FIG. 6 , it is also desirable to use a value for the higher midpoint voltage, V M(H) , greater than V OUT ′. V OUT ′ is the output voltage level that reaches the equilibrium in switching regulators. The p-type smart start-up circuit 600 is used for all types of switching regulators driving the load connected between V OUT and power supply. The output voltage of the power-down inverter 614 , V PDB , is zero during power-down mode. As a result, the power-down PMOS transistor 642 is turned on and thus provides an output pull-up path to V DD . Therefore, V OUT of the p-type smart start-up circuit 600 is V DD so that no current flows into the circuits during power-down mode. On the contrary, it was stated earlier that V OUT , must be zero when power-down mode occurs in FIG. 4 and FIG. 5 .
[0032] FIG. 7 illustrates a p-type dual smart start-up circuit 700 in accordance with the present invention. The p-type dual smart start-up circuit 700 is a modification of the circuit described in FIG. 6 . The gate terminal of a PMOS transistor 708 is connected to a proper fixed-bias voltage (not shown) or ground (e.g., “0”, low, etc.). The gate terminal of a NMOS transistor 726 is connected to a proper fixed-bias voltage (not shown) or power supply voltage (e.g., V DD , “1”, high, etc.). Compared to FIG. 6 , the first difference to note here is that the lower-voltage sensing inverters 702 and 712 (i.e., an even number of inverters) are added into FIG. 7 in order to sense the lower-voltage. The second difference to note here is that the output of the second lower-voltage sensing inverter 712 is connected to the gate terminal of the PMOS transistor 706 . The p-type dual smart start-up circuit 700 is able to sense the lower-voltage as well as the higher voltage while the p-type smart start-up circuit 600 is able to sense only the higher voltage.
[0033] No current flows out of the drains of the PMOS transistors 706 and 708 if V OUT is greater than V M . V M is the lower midpoint voltage decided by the device aspect ratios of the first lower-voltage sensing inverter 702 . If V OUT is less than V M , the PMOS transistor 706 is turned on until V OUT goes up to V M . In design of the p-type dual smart start-up circuit of FIG. 7 , it is also desirable to use a value for the higher midpoint voltage, V M(H) , greater than V OUT ′ and a value for the lower midpoint voltage, V M , less than V OUT ′. V OUT ′is the output voltage level that reaches the equilibrium in switching regulators. The p-type dual smart start-up circuit 700 is used for all types of switching regulators driving the load connected between V OUT and power supply. V OUT =V DD in the p-type dual smart start-up circuit 700 ensures that no current flows into the circuits during power-down mode.
[0034] In summary, the five smart start-up circuits of the present invention within switching regulators simply control how fast the output voltage level reaches the equilibrium from an initial output voltage level. The balance between PMOS output resistance and NMOS output resistance is important to obtain high output resistance. Furthermore, the CMOS process variations usually must be considered so that the proper value of the midpoint voltage is chosen for all the smart start-up circuits 300 , 400 , 500 , 600 , and 700 . Each bulk of two stacked PMOS transistors can be connected to its own N-well to obtain better immunity from substrate noise in all the smart start-up circuits 300 , 400 , 500 , 600 , and 700 .
[0035] The smart start-up circuit 214 shown in FIG. 2 represents the basic smart start-up circuit 300 , the smart start-up circuit 400 , and the dual smart start-up circuit 500 , as shown in FIG. 3 , FIG. 4 , and FIG. 5 , respectively. Also, the p-type smart start-up circuit 224 shown in FIG. 2 represents the basic smart start-up circuit 300 , the p-type smart start-up circuit 600 and the p-type dual smart start-up circuit 700 , as shown in FIG. 3 , FIG. 6 , and FIG. 7 , respectively. The conventional switching regulator 100 and the switching regulator system 210 including the basic smart start-up circuit 300 are simulated using the same components. As a result, the total simulation time of the conventional switching regulator 100 is 40 hours and that of the switching regulator system 210 using (W/L) MP1 =6u/1u of the PMOS transistor 306 is 3 hours. This improvement can be accomplished by simply inserting a proper one of the smart start-up circuits into any conventional switching regulator, and the simulation time can be reduced by a factor of 13. It should be noted that the same time step has been used for the SPICE simulation in order to accurately measure and compare the simulation time of all circuits.
[0036] All the smart start-up circuits of the present invention are very efficient to implement in system-on-chip (SOC) or integrated circuit (IC). The present invention provides five different embodiments which achieve a drastic improvement in a very fast start-up time, start-up time controllability, performance, time-to-market, power consumption, power and time management, efficiency, cost, and design time. While the present invention has been described in particular embodiments, it should be appreciated that the present invention should not be construed as being limited by such embodiments, but rather construed according to the claims below. | 4y
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BACKGROUND OF THE INVENTION
This invention relates generally to a method of and apparatus for determining the temperature and other thermodymanic characteristics of an object, and particularly relates to a method of and apparatus for measuring the temperature of a highly reflective moving object.
In the prior art various types of temperature measuring apparatus are known, for example, a color pyrometer which is a device designated to measure the temperature of an object by determining the intensity of its radiation at two different wave length regions. Such a two-color pyrometer is quite satisfactory for determining the temperature of an object provided the object is a black or so called gray body. A gray body as used here is defined as having a radiation intensity over different wave lengths which generally follows Plank's laws except that the intensity of its radiation is less by a fixed amount than the radiation of a black body. However, if the object is not a black body or is a non-gray body and therefore has a radiation intensity distribution over different wavelengths which does not follow Plank's laws, a two-color pyrometer will not, in general, indicate the true temperature of the object.
Another type device used to measure the temperature of an object is a total radiation pyrometer. As the name implies this device measures the total radiation emitted by an object. Conventionally, a total radiation pyrometer makes use of a black body which is used as a reference body. In one type of total radiation pyrometer the reference body is held at a fixed temperature and the radiation intensity of the reference body and that of the object being measured are compared after taking into account any differences in the distances between the reference body and its detector and the object and its detector. Again, the object is assumed to have a radiation distribution of either a black body or a gray body.
Another type of total radiation pyrometer has been devised to overcome the disadvantages of the two devices previously discussed. This is also a total radiation pyrometer but has been adapted so that the reference body and an opaque object are positioned in close proximity. As a result, when the temperature of the object and the black body are the same the body is in a substantially isothermal enclosure, i.e. the object is essentially in a black body environment. This construction is advantageous because it ensures that Kirchoff's law is obeyed by the radiation emitted and reflected by the object. When the reference body is not at the same temperature as the object, the sum of the energies emitted and reflected by the object are not numerically equal to that from the black body at the same temperature which is positioned in place of the object.
The radiation emitted by the black body is measured by a first detector and a second detector measures the radiation emitted by the object as well as the radiation of the black body reflected by the object together. It is essential for the operation of such a pyrometer that a black body environment be provided for the object which means that the black body must be in close proximity to the object. Under certain conditions this constraint cannot be met, for example, if the object, the temperature of which is being measured, is located in an induction furnace, it may be impossible to position the black body also in the induction furnace without disturbing the electric field created in the induction furnace and without adversely affecting the operation of the black body. Also, there are definite limits which define the geometric relationship between the object, the black body and the respective detectors. In such a total radiation pyrometer the black body must be of a relatively large size and therefore has considerable thermal lag.
Another apparatus for measuring temperature at the surface of an object using infrared radiation is described in U.S. Pat. No. 3,924,469 which discloses an apparatus comprising a variably heated metallic body which serves as a compensating radiator, a reflective member mounted on a shaft within a cavity provided within the compensating radiator body for rotation, or alternatively oscillation, about an axis forming an oblique angle to the plane of the reflective member such that in one position of the reflective member only infrared radiation from the surface of the object is reflected by it into a radiation detector, while in another position of the reflective member only infrared radiation from a wall surface of the cavity within the compensating radiator is reflected by it into the radiation detector whereby infrared radiation from the object and compensating radiator are admitted to the radiation detector in alternation. The detector then produces an alternating current signal determined by any temperature differential existing between the object and the heat supply to the compensating radiator is varied in accordance with the signal in such sense as to reduce the signal to zero whereby the temperature of the compensating radiator then equals the temperature of the object.
With the exception of attaching dyestuff, dielectric media and other foreign substances to the object and observing their temperature related characteristics from a distance, no practical radiation pyrometry methods of measuring the temperature of an object without physical contact exist. Radiation pyrometry methods have in the past been of limited usefulness because both the radiation being emitted by the object and the radiation being reflected by it influence the value obtained by such methods. In order to ensure precise temperature measurements by use of radiation pyrometry methods it is important to reduce the radiation from extraneous sources which is reflected from the object and extracted by a sensor. Additional radiation pyrometry methods are disclosed in U.S. Pat. Nos. 3,057,200; 3,364,066; 3,413,474; 3,462,602; 3,073,122; 4,172,383; 4,233,512 and general radiation theory is also discussed in standard texts for the study of physics, however, it is not felt that these references are particularly relevant to the invention disclosed and claimed herein.
In the art of continuous casting and rolling of aluminum the difficulties in continuously measuring the temperature of the cast bar between the casting machine and the rolling mill are compounded by the reflective and emissivity characteristics of the cast alulminum bar. The radiative surface properties of a cast aluminum bar are a function of the surface quality and alloy composition surface properties can also be functions of the solidification process itself, for example, inverse segregation will significantly alter the surface characteristics of a cast bar. Also, the amount of thermal radiative energy from the cast bar which reaches an infrared sensor is affected by the intervening atmosphere which absorbs, reflects, scatters and re-emits radiative energy, as well as the geometry of the sensor location relative to the cast bar. The problem of accurately measuring the cast bar temperature of an aluminum cast bar by infrared radiation pyrometry is made even more complex because of the temperature range being measured and because aluminum characteristically has a low and extremely variable (0.02 to 0.6) emissivity and the combination of these factors create problems in discriminating between the signal from the cast bar and extraneous signals from the surroundings.
The exact composition of an aluminum cast bar depends upon the alloy specified by a customer and by specified physical properties which are desired for a finished product to be produced from the bar being cast. All such variations are reflected in changes in both the optical and thermal radiative properties of the bar surface. Also, the amount of surface oxidation, surface scale and other surface characteristics are variable from one alloy to another. Additionally the surface characteristics and indirectly the thermal radiative properties of the cast bar can be changed by variations in process parameters.
SUMMARY OF THE INVENTION
Briefly described, the present invention comprises a method of and apparatus for continuously measuring the temperature of moving and reflective substrate without the necessity of the temperature sensor coming into direct physical contact with the moving substrate. The moving substrate (for example cast metal bar and billet) emerging from a casting machine is passed through an apparatus adapted to apply a uniform layer of soot to the bar surface, detect infrared radiation being emitted from the blackened area of the cast bar and convert the detected radiation into an electrical temperature signal which is displayed in meaningful fashion, and completely remove the soot from the surface of the cast bar before the cast bar enters a rolling mill which then rolls the cast bar into a rod.
It is therefore an object of this invention to overcome the disadvantages setforth above.
It is another object of this invention to make it possible to accurately measure the temperature of a moving reflective material without physically contacting the moving material with the measuring device.
Another object of this invention is to provide a method of and apparatus for making an accurate emissivity based temperature measurement of a moving highly reflective substrate.
It is another object of this invention to provide a method of and apparatus for measuring the temperature of a moving reflective substrate which negates the influence of substrate surface properties upon the optical and thermal radiative properties of the substrate.
It is still another object of the present invention to provide a method of and apparatus for continuously measuring the temperature of a moving reflective substrate which is not influenced by the composition of the alloy which makes up the substrate.
Yet another object of the present invention is to provide a method of and apparatus for continuously measuring the temperature of a moving reflective substrate which eliminates the problem of discriminating between the signal from the substrate and extraneous signals from the surroundings.
A further object of the present invention is to provide a radiation pyrometric method for measuring the temperature of a moving substrate which is unaffected by reflected radiation.
These and other objects, features and advantages inherent in the present invention will become apparent from the accompanying drawings and the following detailed description thereof wherein like numerals indicate like parts throughout the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagramatic representation of the temperature measuring device of the present invention.
FIG. 2 is a diagramatic representation of the automatic sooter which makes up a part of the temperature measuring device of the present invention.
FIG. 3 is a diagramatic representation of the lens purging apparatus which makes up a part of the temperature measuring device of the present invention.
FIG. 4 is a diagramatic representation of the soot removal and sensor cooling portions of the temperature measuring device of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to the drawings, FIG. 1 shows a cast bar 10 advancing from a casting machine (not shown) toward a rolling mill 14. A cast bar 10 advances toward mill 14 it passes through sooter 16 which burns acetylene to form a uniform layer of soot which deposits on the surface of cast bar 10. After soot is uniformly applied to its surface, cast bar 10 continues to advance toward mill 14 and passes infrared radiation sensor 18 where infrared radiation which is emitted from bar 10 is detected. The detected infrared radiation is converted into an electrical signal in sensor 18, simplified by amplifier 20 and transmitted to recorder 21, digital display 23 or other remote instruments not shown where it is displayed in a useful fashion or used as control input data. Cast bar 10 continues to advance and passes atomizer 22 where the soot coating is removed by means of a fine water spray or water oil emulsion spray directed against bar 10 by atomizer 22 which causes the carbon to fall from the cast bar 10.
Automatic sooter 16 is illustrated in more detail in FIG. 2. The acetylene supply means 19 which supplies acetylene to sooting tips 17 is adapted to provide a constant flow of acetylene regardless of the pressure of the acetylene source. This is accomplished by first flowing the acetylene through acetylene filter 24 where gas borne solid impurities are removed. After exiting the filter 24 the acetylene passes through a solenoid valve 25 which is adapted to receive remote signals capable of interrupting or starting the flow of acetylene through the system. From solenoid valve 25 the acetylene passes to flow control valve 26 where the flow rate of the acetylene is adjusted to a constant rate which is thereafter independant of the upstream pressure of the general source of acetylene supply. The acetylene then flows from the flow control valve 26 to flow meter 27 and thence to mixer 28 where it is mixed with air before being conveyed to manifold 20 to which sooting tips 17 are attached. The air which is mixed with the acetylene in mixer 28 follows a similar and parallel path from the general air supply to mixer 28. Air flows through air supply means 19 to filter 24a which removes any air borne particulate contaminants. After passing through air filter 24a the air then passes through solenoid valve 25a which is adapted to receive remote source signals capable of interrupting or starting the flow of air through the system. From solenoid valve 25a the air then passes to flow control valve 26a where the flow rate is adjusted to a constant rate which is independant of the pressure of the general source of air supply. Air then flows from flow control valve 26a through flow meter 27a to mixer 28 where it is mixed with the acetylene and the air acetylene mixture is then transported to manifold 29 for subsequent soot production at sooting tips 17. Ignition of the air acetylene mixture flowing from sooting tips 17 is accomplished by positioning an electric igniter 30 in the stream of air fuel mixture flowing from tips 17. The electric igniter ignites the acetylene-air mixture and the mixture of acetylene and air is regulated to burn in such a way to promote soot formation so that a layer of soot will be deposited by convection and system pressure on cast bar 10 as it advances past and through the burning air-acetylene mixture. An electric igniter of the glow-plug type has been used with best results but both a spark plug type igniter or pilot flame could also be used successfully. Carbon could also be applied as a spray or by electrostatic deposition methods but such methods are temperature dependent and must be closely controlled. Soot applied using the automatic sooter 16 can be applied in varied thicknesses and with proper acetylene and air flow rates (for example 12 cubic feet per minute acetylene and 20 cubic feet per minute air) essentially no free atmospheric soot is experienced when tips 17 are of the Horns H-1 type and are positioned approximately three to four inches from the cast bar. At such use levels, approximately 7 to 8 pounds of soot would be deposited on the substrate in a five day, 24 hour per day work week if the equipment were operating at eighty percent efficiency. In the operation of the automatic sooter 16 an air supply of from 20 to 200 psi (2 to 5 scfh) is required and an acetylene supply of a maximum 15 psi at 5 to 20 scfh per hour is required.
Cast bar 10 which has been blackened with soot produced by automatic sooter 16 advances past infrared sensor 18. Because the cast bar 10 has been blackened, the emissivity of the bar passing sensor 18 becomes the emissivity of the carbon coating (from about 0.78 to about 0.80 in the temperature range of from room temperature to 1000° F.) instead of the highly variable emissivity of an uncoated aluminum cast bar. Therefore, accurate bar temperature measurements can be made with very little variation (K 3° F. within the separational temperature range).
When the cast bar 10 is coated with soot the radiative surface properties of the bar are made substantially constant and because the black surface will absorb and not reflect radiative energy from other sources, the radiation detected relates to the absolute temperature of the emitting object (cast bar 10) and therefore such detected radiation can be used to monitor the temperature of the emitting object.
Because the ambient temperature in the vicinity of a continuous casting and rolling line can reach temperatures in excess of 100° F. cooler 32 is used to cool sensor 18. This cooling is accomplished by using a water system the used water from which is routed to atomizer 22 via water delivery means 33 for spraying thereof onto the cast bar 10. Cooling water is supplied to cooler 32 via water supply means 33a with the motive force necessary to move the water being supplied by the flow of air through atomizer 22 which is of the Venturi type. Lens 34 of sensor 18 is kept free of dust and other particulate matter which might interfere with reception of infrared radiation from cast bar 10 by continuously purging the lens 34 and lens area with either air, nitrogen, helium or mixtures thereof which is delivered to the lens through purging gas purge line 35. Purging gas entering purge line 25 from the source of purging gas (not shown) passes through filter 36 which houses a filter element fine enough to remove any harmful particulate contaminants which might be in the unfiltered purging gas. After passing through filter 36 the purging gas passes through flow control unit 37 so that a constant flow of purging gas to lens 34 is assured without regard to intermittent increases or decreases in the pressure of the purging gas. A flow meter 38 is also provided downstream of flow control unit 37 so that the operator may select the desired flow rate of the purging gas being supplied to lens 34 through purging line 35. This introduction of a purging gas into lens 34 creates a positive pressure within the lens body thereby preventing carbon particles or other particulate contaminants from entering the lens and interfering with the accurate sensing of radiant energy from cast bar 20.
While it is necessary to apply the soot to the surface of cast bar 10 to accurately measure the radiant energy being emitted by the bar, it is equally as necessary to completely remove all of the soot from bar 10 before the bar enters rolling mill 14. If the soot is not removed, the carbon particles will be removed from the surface of rod by the rolling lubricant and will soon so alter the lubricating properties of the rolling lubricant that production will have to be curtailed or stopped altogether while contaminated rolling lubricant is replaced with fresh lubricant. In order to avoid such an occurance, the apparatus of the present invention has had included in it a device designed to completely remove the soot from the surface of bar 10 before the bar enters rolling mill 14.
Referring to FIG. 4 for a more detailed view of this device, it can be seen that cooler 32 which maintains the temperature of sensor 18 within the optional operating range for infrared radiation sensors is adapted to allow the cooling water which enters from coolant supply line 32a to drain from the sensor area through drain line 32b. Cooling water thus removed from sensor 18 is accumulated in reservoir 40 and as needed withdrawn from reservoir 40 through atomizer supply line 41 by the flow of air through Venturi type atomizer 43. Water being withdrawn from reservoir 40 is filtered through submerged filter 42 as it enters supply line 41. This filtered water is then conveyed to atomizer 43 where it is applied to the soot bearing surface of cast bar 10 in quantities sufficient to remove all residual soot from the surface of bar 10. Usually no more than about one-half to one liter of water per hour is required to completely remove all residual soot from the bar surface depending on production rate and size of bar. A soluble oil and water emulsion may be used to remove the soot from bar 10 with equal success. Atomizer 43 requires air to draw water from reservoir 40 and propel the water droplets onto the cast bar 10, this air is supplied to atomizer 43 through air line 44. Air entering atomizer 43 through line 44 is filtered through filter 45 before entering the atomizer 43 to prevent blockages caused by particulate contaminants borne by the unfiltered air. Soot may also be removed from bar 10 by using a torch (not shown) and a very lean oxidizing flame which completes combustion of the soot. In any event, it is necessary to carefully remove the soot from bar 10 to prevent the harmful effects described above and to avoid significantly altering the temperature of bar 10 before it enters the rolling mill 14 because, an increase or decrease from optimum rolling temperature can significantly harm the physical and electrical properties of the rod being rolled from cast bar 10.
To demonstrate the effect of reflected radiant energy upon the temperature of a cast aluminum alloy bar, soot was applied to a cast bar which had implanted in it a type "K" thermocouple. The temperature of the soot covered area of the cast bar was determined to be approximately 800° F. when the temperature of the bar was measured by the infrared radiation technique of the present invention and the temperature of the cast bar as measured by the type "K" thermocouple was also measured as approximately 800° F. while the temperature measured by an infrared sensor focused on an area of the bar having no soot covering was lower than 500° F. Additionally experiments also demonstrated that within reasonable limits, the thickness of the soot layer covering the bar has no appreciable effect on the accuracy of the measurements made by the method and apparatus of the present invention so long as the bar surface is completely covered.
This invention has hereinbefore been described in terms of one preferred embodiment but it is understood that variations and modifications can be effected within the spirit and scope of the invention as described and as defined in the appended claims. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application relates to application Ser. No. 10/143,313, entitled “Distributed Configuration-Managed File Synchronization Systems,” and application Ser. No. 10/142,413, entitled “Delta Transfers in Distributed File Systems,” both filed concurrently herewith and in the name of the present assignee. All these documents are hereby incorporated by reference for all purposes.
FIELD OF INVENTION
The subject of this application relates generally to the field of data transfer. More particularly, an embodiment of the present invention relates to provision of persistent queuing in distributed file systems.
BACKGROUND OF INVENTION
As the use of digital data becomes more prominent in everyday life, the need for access to reliable data sources increases. For example, a user may need regular access to data that can be physically located across different buildings or even around the world. This is often the case with respect to large company projects that may involve many groups worldwide working on a same solution.
As these types of joint projects become more commonplace, so does the need for having access to such data in real-time. In other words, the data accessed by each remote site will need to be current whether that data is stored locally or halfway around the world. Accordingly, the users need to have access to the latest version of the data as soon as it is released into the system from any site.
In many current implementations utilizing transmission control protocol/Internet protocol (TCP/IP), file transfer protocol (FTP), and other similar facilities (e.g., RSYNC command provided in Unix systems) are utilized to maintain data amongst remote sites. These tools, however, are generally useful only for transferring files from one point to the next. Moreover, automation of these tools only results in synchronization among multiple sites when a batch update or a nightly synchronization is performed. Also, if one of the remote sites goes down or cannot accept external data, the data may be dropped and unavailable.
SUMMARY OF INVENTION
The present invention, which may be implemented utilizing a general-purpose digital computer, includes novel methods and apparatus to provide persistent queuing for distributed file systems that can provide ready access to data among remote users. In an embodiment, an apparatus is disclosed. The apparatus includes a distributed file system including a plurality of remote systems. The plurality of remote systems includes a sender site and a receiver site. The apparatus further includes a local queue accessible by the sender site; a remote queue accessible by the receiver site; a next attempt time indicator; and an attempt counter. The next attempt time indicator may specify a next time to install a transferred file on the receiver site. The attempt counter indicates how many attempts have been made to install the transferred file on the receiver site.
BRIEF DESCRIPTION OF DRAWINGS
The present invention may be better understood and its numerous objects, features, and advantages made apparent to those skilled in the art by reference to the accompanying drawings. These drawings, however, should not be taken to limit the invention to the specific embodiments, but are for explanation and understanding only.
FIG. 1 illustrates an exemplary computer system 100 in which the present invention may be embodied;
FIG. 2 illustrates an exemplary network configuration 200 in accordance with an embodiment of a present invention;
FIG. 3 illustrates an exemplary communication system 300 in accordance with an embodiment of a present invention;
FIG. 4 illustrates an exemplary local queue 400 in accordance with an embodiment of a present invention; and
FIG. 5 illustrates an exemplary remote queue 500 in accordance with an embodiment of a present invention.
The use of the same reference symbols in different drawings indicates similar or identical items.
DETAILED DESCRIPTION
In the following description, numerous details are set forth. It will be apparent, however, to one skilled in the art, that the present invention may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form, rather than in detail, in order to avoid obscuring the present invention.
Reference in the specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
FIG. 1 illustrates an exemplary computer system 100 in which the present invention may be embodied in certain embodiments. The system 100 comprises a central processor 102 , a main memory 104 , an input/output (I/O) controller 106 , a keyboard 108 , a pointing device 110 (e.g., mouse, track ball, pen device, or the like), a display device 112 , a mass storage 114 (e.g., hard disk, optical drive, or the like), and a network interface 118 . Additional input/output devices, such as a printing device 116 , may be included in the system 100 as desired. As illustrated, the various components of the system 100 communicate through a system bus 120 or similar architecture.
In an embodiment, the computer system 100 includes a Sun Microsystems computer utilizing a SPARC microprocessor available from several vendors (including Sun Microsystems of Palo Alto, Calif.). Those with ordinary skill in the art understand, however, that any type of computer system may be utilized to embody the present invention, including those made by Hewlett Packard of Palo Alto, Calif., and IBM-compatible personal computers utilizing Intel microprocessor, which are available from several vendors (including IBM of Armonk, N.Y.). Also, instead of a single processor, two or more processors (whether on a single chip or on separate chips) can be utilized to provide speedup in operations. It is further envisioned that the processor 102 may be a complex instruction set computer (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing a combination of instruction sets, and the like.
The network interface 118 provides communication capability with other computer systems on a same local network, on a different network connected via modems and the like to the present network, or to other computers across the Internet. In various embodiments, the network interface 118 can be implemented in Ethernet, Fast Ethernet, wide-area network (WAN), leased line (such as T1, T3, optical carrier 3 (OC3), and the like), digital subscriber line (DSL and its varieties such as high bit-rate DSL (HDSL), integrated services digital network DSL (IDSL), and the like), time division multiplexing (TDM), asynchronous transfer mode (ATM), satellite, cable modem, and FireWire.
Moreover, the computer system 100 may utilize operating systems such as Solaris, Windows (and its varieties such as NT, 2000, XP, ME, and the like), HP-UX, IBM-AIX, Unix, Berkeley software distribution (BSD) Unix, Linux, Apple Unix (AUX), and the like. Also, it is envisioned that in certain embodiments, the computer system 100 is a general purpose computer capable of running any number of applications such as those available from companies including Oracle, Siebel, Unisys, Microsoft, and the like.
It is envisioned that the present invention may be applied to systems, which utilize a revision control system (RCS) and meta data information, individually or in combination. The RCS can be configured as a backend storage system including the actual files. It is envisioned that RCS may be hidden from users. The meta data information can include data about the actual files. The meta data may be stored in a database, such as that provided by Sybase, Inc., of Emeryville, Calif. The meta data may include relational information, block and sector information, file type, and the like.
FIG. 2 illustrates an exemplary network configuration 200 in accordance with an embodiment of a present invention. As illustrated, the network configuration 200 includes three hubs (Hub 1 202 , Hub 2 204 , and Hub 3 206 ) as an example. The hubs may be configured to communicate with each other through any number of networking tools including a point-to-point connection. Each of these hubs may have their own spokes. For example, Hub 1 202 may have spokes 208 , 210 , and 212 . Similarly, Hub 2 204 may have spokes 214 – 218 and Hub 3 may have spokes 220 – 224 . All spokes on a single site may be grouped together to form a local subnet (e.g., with one hub and multiple spokes). Each remote site may be connected in a star topology (e.g., with the hub at the center of the star).
Each spoke may have a set of configuration parameters defined in a local or remote database. When the spoke is brought up, the spoke may utilize the configuration parameters to configure itself or auto-configure. Accordingly, each site may be easily reconfigured by, for example, changing the entries in the database that contains the configuration data for each site. Each spoke ( 208 - 224 , for example) can have the following configuration parameters defined, in addition to any already existing ones:
1. VectorIn: a vector that contains the list of Ids for sites (siteIds) that send files to the spoke; 2. VectorOut: a vector that contains the list of siteIds that receive files from the spoke; and/or 3. Pass through or Store-n-go field: this field indicates to the spoke whether that spoke is just a connector or a hub (for example, with a buffer and no central directory) or a spoke (which, for example, makes a copy of the file it is transferring into the spoke's central directory).
Depending on the above parameters, each spoke can then become a hub or a spoke. Furthermore, in an embodiment, all hubs need not be in pass-through mode, and all spokes may be in store-n-go mode. For example, on a site, if there is a single spoke, it is unnecessary to add another hub on the same site. The only spoke can then act as a hub in store-n-go mode. So, each site may be configured as per the requirements at that site. In an embodiment, some of the advantages of such an architecture are that each site only transfers the file once to the other sites, but not to each spoke. This reduces network traffic. Also, such an architecture is very scalable, and is highly flexible to accommodate different configurations at each site.
In some embodiments, it is envisioned that hubs may not have users working on them. So, no new files may be created on such hubs. In case a hub hosts users, that hub may be configured similar to a spoke. For example, that hub can transfer the given file locally to all spokes, and transfer a copy to each of the remote hubs.
It is envisioned that a hub may differentiate between the local-domain generated file and the file that it received from a foreign domain. In one embodiment, the receiving entity (or module), for example upon receiving a file, can check to see if the origin site of the file is the same domain as the hub. If so, the file does not need to be routed any further and can be just locally copied. On the other hand, if the domain of the origin site is different, the hub knows that it has to transfer a copy of the file to each of the local spokes.
It is also envisioned that this checking may be performed by, for example, employing a FileReceiver module. The FileReceiver module can receive files and may run as a thread on a general-purpose computer or an appropriate networking device. The FileReceiver upon receiving a file may: (1) ensure that the received file is accurate (for example, by performing checksum validations) and/or (2) check the file origin (and if the file is foreign, the FileReceiver can route the received file locally). In an embodiment, the step (2) above can be done by the FileReceiver present on a hub rather than on a spoke. In an embodiment, if the FileReceiver module has to route the file, the FileReceiver module can insert entries into, for example, a transfer table in a database (e.g., locally). In one embodiment, there can be one entry per each local spoke in the database. Another process, e.g., a database reader (DBReader such as that discussed with respect to FIG. 3 ), can then handle additional work for transferring the file.
Accordingly, the routing information can be stored in a database. In an embodiment, with the above-proposed architecture, each hub may know which domain it belongs to, and what spokes exist on its local domain. Also, each spoke may know to which other spokes and hubs is it directly connected. For example, an entry in a transfer table can be inserted for each spoke and/or hub that the given local spoke is directly connected to. In certain embodiments, the DBReader module on the local spoke can then handle or initiate the transfers.
FIG. 3 illustrates an exemplary communication system 300 in accordance with an embodiment of a present invention. The communication system 300 includes a sender site 302 and a receiver site 304 . The sender site 302 includes a database 306 (DB), an RCS 308 , a DBReader module 310 , and a send daemon 312 . It is envisioned that the database 306 may store meta data and other data as required. The RCS may be hidden from users and store actual files being transferred and/or maintained on the sender site 302 . The DBReader module 310 can be a process that may run on a computer system (such as that discussed with respect to FIG. 1 ). In certain embodiments, the DBReader module 310 may be run on a multitasking system as a process, for example. The DBReader module 310 may run on a system continuously. It is envisioned that the DBReader module 310 has access to the database 306 and the RCS 308 , and can process the stored data. The DBReader module 310 may initiate a file transfer process by, for example, reading a job description from a transfer table stored, for example, in the database 306 .
In an embodiment, the DBReader module 310 may further communicate with the send daemon 312 . It is envisioned that the send daemon 312 can be responsible for sending data from the sender site 302 to the receiver site 304 . The send daemon 312 can be a Unix daemon thread or other similarly configured process running on a computer system. The send daemon 312 may be configured to run in the background so it can be activated with short notice. In one embodiment, the send daemon 312 may be a thread spawned from the DBReader module 310 .
The send daemon 312 may have access to a local queue 314 (internal or external to the send daemon 312 ). The local queue 314 may provide storage capabilities to the send daemon 312 . It is envisioned that the local queue 314 may be any type of storage such as random access memory (RAM), its varieties such as dynamic RAM (DRAM), static RAM (SRAM), synchronous DRAM (SDRAM), and the like. Further information regarding the local queue 314 may be found by reference to FIG. 4 .
The receiver site 304 includes a database 316 , an RCS 318 , a monitor 320 , and a remote server 322 . The database 316 and RCS 318 may be similar to those of the sender site 302 (i.e., database 306 and RCS 308 ). The monitor 320 can be on lookout for information of interest and inform a selected party (e.g., a user) about the status of the information desired. For example, the monitor 320 may be a visual aid indicating status of a transfer in real-time. The remote server 322 can have access to the database 316 , RCS 318 , and monitor 320 . The remote server 322 may also have access to a remote queue 323 (RemoteQ). The remote queue 323 may be a similar device such as that discussed with respect to the local queue 314 . The remote queue 323 can provide the remote server 322 with storage capabilities. It is envisioned that the remote queue 323 may store meta data for the receiver site 304 . Also, the remote queue 323 may provide memory for delivered job descriptions which are uninstalled. Further information regarding the remote queue 323 may be found by reference to FIG. 5 .
The sender site 302 can also include one or more file sender/s 324 which may communicate with one or more, respective, file receiver/s 326 . This communication may also utilize acknowledge capabilities to ensure a file is properly transferred. Other error correction capabilities may also be used to ensure proper communication between the file senders 324 and file receivers 326 . Such error correction capabilities may include parity checking, M0–5 checksum validation, and the like. The file senders 324 may hold all information about the file that is being transferred. Further, it is envisioned that the file sender 324 may perform one or more of the following: physically transfer a file from the sender site 302 to the receiver site 304 , obtain acknowledgment regarding the transfer, update a ReceivedTime field (indicating when the data sent was received), for example, in the transfer table that may be stored in the database 306 . The file sender 324 can be a thread spawned by the send daemon 312 .
The file receiver 326 may be responsible for one or more of the following tasks: receiving files over, for example, a TCP socket, re-calculating the checksum, verifying file correctness, copying the file into the designated buffer area, sending an ACK/NAK signal (to acknowledge receipt or non-receipt), remove the current entry (or row) from queue of the remote server 322 , and update the file receiver count at the remote server 322 . In some embodiments, the file receiver 326 may be a thread spawned by a remote server routine.
The sender site 302 can additionally include a command sender 328 for sending commands from the sender site 302 to a command executor (CE) 330 on the receiver site 304 . It is envisioned that the command sender 328 may perform one or more of the following: start a server socket, wait for the acknowledgment from the command executor 330 , and update the appropriate database (such as the database 316 ). Moreover, the command sender 328 may be a thread spawned by the remote server 322 . Furthermore, the command executor 330 may perform one or more of the following: connect to the command sender 328 , execute the command (e.g., copy data, delete data, and/or delete directory), send acknowledgment, and update information about when an action is done in an appropriate database (such as the database 316 ). Moreover, the command executor 330 may be a thread spawned by the remote server 322 .
In an embodiment, the sender site 302 can include a command manager (Cmd Mgr) 334 and a monitor 336 . The monitor 336 may be similar to that discussed with respect to the receiver site 304 (i.e., the monitor 320 ). The command manager 334 is envisioned to be able to communicate (directly or indirectly) with the remote server 322 and to execute commands. Such commands may, for example, include push data and pull data, which can be used to change the priority on a file that is being transferred, so that it is shipped ahead of or after the rest (or select ones) of the current queue members.
The receiver site 304 can further include one or more file installer/s 332 . The file installers 332 may perform one or more of the following: verify whether meta data of predecessor and object being installed are in place, verify whether the RCS 318 of predecessor is in place, install the object into the RCS 318 , update object's meta data, send acknowledgment as required, update flags including CompleteTime (indicating the time the installation was complete) and Installation Message (any messages resulting from the installation) on, for example, a source database (where the file being installed is located), and delete any unused buffer files utilized for the installation. It is envisioned that the file installer 332 may be a thread spawned by the remote server 322 .
It is also envisioned that the send daemon 312 may perform one or more of the following: perform handshake operations between the sender and receiver sites, initiate a file transfer or a command execution, execute a remote method invocation (RMI) call on the remote server 322 , transfer job description, request/provide a port number, spawn a file sender (such as 324 ) along with passing relevant port information, spawn a command sender (such as 328 ), wait on the local queue 314 for more jobs, and keep a balance in the number of existing transport channels. Further, the remote server 322 may provide remote methods to the send daemon 312 to initiate a file transfer or a command execution. The remote server 322 may also keep an account on file receiver/file installer counts, spawn the file receivers 326 to receive files, and spawn file installers 332 when the remote queue 323 receives a new member.
The communication system 300 may further include a service provider 338 . The service provider 338 may provide a variety of services to the system components including one or more of the following: handling periodic registrations from key modules, subscribing and unsubscribing of available monitoring services, routing the monitor messages to the corresponding monitors, and providing a pointer to the correct log file for remote modules. It is envisioned that one service provider 338 is sufficient for the entire system. In an embodiment, the service provider 338 may run on a primary site.
Also, the communication system 300 may further include a database manager module (not shown), which may provide useful application programming interfaces (APIs) to, for example, insert, update, delete, and select information on various tables in the databases present in the communication system 300 . Such a database manager may be implemented as a Java object.
It is envisioned that an interface between a user command and transparent transport layer may be a database. More specifically, this interface may be a transfer table. Such a transfer table may store the required information about each file transfer. Each user command, after successful completion, may in turn deposit a transfer request into the transfer table. Furthermore, it is envisioned that the DB Reader 310 may be present on all sites where there is a possibility of users checking in files. The DB Reader 310 having sensed what needs to be transferred can buffer the jobs into the respective queues of the destinations. It also can spawn the send daemon 312 , for each destination and from then on, it may hand over the corresponding queue to it. The send daemon 312 may then handle the handshake between itself and the remote server 322 , and establish full-duplex communication channels for example, to transfer files and receive acknowledgments. This may involve creation of file sender—file receiver pairs ( 324 and 326 , respectively) on sender and receiver sites, respectively. If the command is other than create or save data, the command sender 328 and command executor 330 pairs may be created.
The file sender 324 can transfer a file, and the checksum of that file over the established channel, and wait for the acknowledgment from the file receiver 326 . The file receiver 326 having received the file, may perform a checksum verification between the received checksum, and the re-calculated checksum on the receiver site 304 . If they tally, a positive ACK maybe sent to the file sender 324 . Otherwise, a NAK may be sent. Upon receiving an ACK, the file sender 324 may update the ReceivedTime in, for example, the transfer table and exit. On receiving a NAK, the file sender 324 may re-transfer the file. The iteration may be continued until a positive ACK is received, or once the file sender 324 times out. If the file sender 324 times out, it may enter a panic state, and send out e-mails to an appropriate target (such as a system administrator).
Once a file is received correctly, the file receiver 326 may copy the file to its designated buffer area, and enter the job description into the remote queue 323 , and also register the job in an appropriate (e.g., RemoteQ) table in the database 316 . In case of the remote server 322 break down, the remote queue 323 may rebuild the required information from the database 316 . In such a case, the remote server 322 may start a FileInstaller thread for each file received (such as file installer 332 ). The FileInstaller can be responsible for the installation of the file in the RCS 318 , and for updating a VersionHere bit in a FileVersions table in the database 316 . The FileInstaller may perform a series of checks for the presence of both the predecessor's and the file's meta-data, and also the RCS version of the predecessor. Upon having verified all the dependencies, the file may be checked into the RCS 318 . Then the FileVersions, TransferConfirm, and RemoteQ tables may be notified of the successful installation, and the CompleteTime and Installation Message entries (or columns) may be set on the source database, i.e., the database on the site where the file originated. This process may complete the file transfer procedure in accordance with an embodiment of the present invention.
The above procedure may be applied where the command is either create or save data. If the command is one of delete data, delete directory, or copy data, a command sender (such as the command sender 328 ) may be started instead of the file sender 324 . The command sender 328 may then wait for the ACK from the corresponding command executor 330 . Having received the ACK/NAK, the acknowledgment may be recorded in the database 316 , and a panic mail may be sent in case of NAK. In case of delete data or delete directory, a deletor thread may be spawned, for example, as a part of the command sender 328 . This thread may wait for the positive acknowledgments from all the sites, for example, from its VectorOut. Having received them, the deletor thread can delete the RCS files from the local central directory, and then clean the meta-data on its site. This process may replicate to other sites, through meta-data replication, for example.
FIG. 4 illustrates an exemplary local queue 400 in accordance with an embodiment of a present invention. It is envisioned that in certain embodiments the local queue 400 may be the same or similar to the local queue 314 of FIG. 3 . Moreover, the order of the fields of FIG. 4 is for illustrative purposes and it is envisioned that these fields may be reshuffled as desired. The local queue 400 may be maintained on a source data site (such as the sender site 302 of FIG. 3 ) and identified in a local site id field 422 . The local queue 400 may include information regarding identity of a destination site, such as in a destination site id field 420 . In an embodiment, the local queue 400 may be responsible for storing job descriptions ( 416 ) and pointers ( 418 ) to actual physical user file and other appropriate meta-data.
Moreover, the local queue 314 may provide one or more of the following functions: storage for unsent jobs and arrangement of pending jobs according to their priority (e.g., first-come, first-serve (FCFS) for jobs with no or same priority). The local queue 400 may keep track of the number of unsent jobs in, for example, an unsent job count field 424 . In an embodiment, the local queue 314 may be implemented as a Java object. The local queue 400 may have the jobs numbered and ordered according to job priority. The local queue 400 may dynamically reorder the queue to accommodate incoming jobs and their priorities. In an embodiment, at any point in time, an instance of the local queue 400 may be maintained in a main memory (such as the main memory 104 and/or the mass storage 114 of FIG. 1 ). If the system reboots, crashes, shuts off, or otherwise loses power, the local queue 400 can be rebuilt from nonvolatile memory (such as the mass storage 114 of FIG. 1 ) in the same manner that existed prior to the power loss.
As illustrated in FIG. 4 , the local queue 400 may include a number of time stamp fields. An InsertTime field 402 indicates the time when a job is inserted into the local queue 400 . The InsertTime field 402 may be updated by a user command responsible for requesting a file transfer, for example. A SendTime field 404 indicates the time when a job (or file) is actually dispatched. The SendTime field 404 may be updated, for example, by the send daemon 312 of FIG. 3 . A ReceivedTime field 406 indicates when a file has reached the destination site (for example the receiver site 304 ). The ReceivedTime field 406 may be updated by a remote server after successfully receiving a transferred file (such as the remote server 322 on the receiver site 304 ). A CompleteTime field 408 indicates when a file is actually installed into, for example, a backend version control system including setting all required flags in an appropriate database, concluding the transaction. With respect to FIG. 3 , such a completion may be achieved once a file installer 332 finishes its tasks including updating the appropriate tables in the database 316 and the RCS 318 . The CompleteTime field 408 may be updated by a remote server on, for example, a receiver site (such as the remote server 322 on the receiver site 304 ).
In an embodiment, the local queue 400 includes an installation message field 410 . The installation message field 410 may store a comment (e.g., a brief one such as one-liner or more extended comment for debugging purposes, for example) regarding installation status of a transaction. The installation message field 410 may be updated by a file installer on a remote site (such as the file installer 332 on the receiver site 304 ). Upon a successful completion, the stored comment may start with “ACK,” and specify that a file was successfully created or saved. Upon a failure, the stored comment may start with “NAK,” and indicate what went wrong. It is envisioned that such a field can be very helpful in debugging and trouble-shooting.
The local queue 400 may be very helpful in calculating delays and elapsed times including how long it took for a file to reach its destination, how long it took for the file to be installed into a version control, how long the file spent on the wire, how long was the waiting for the meta-data and predecessors, and the like. In an embodiment, such information can assist in keeping track of the performance of a system under different network conditions, and help in tuning the system accordingly.
As illustrated in FIG. 4 , the local queue 400 can also include a checksum field 412 . The may contain information regarding checksum of a file being transferred. In an embodiment, the checksum field 412 may be calculated during the insertion of a job into the local queue 412 . A file receiver (such as the file receiver 332 of FIG. 3 ) may compare the checksum on the physical file with the checksum stored in the local queue 412 for correctness. The file can then be rejected if the two values do not match. The local queue 400 can also include a resend field 414 which may be utilized for re-dispatching a job when required (e.g., in cases where the transaction was unsuccessful).
FIG. 5 illustrates an exemplary remote queue 500 in accordance with an embodiment of a present invention. It is envisioned that in certain embodiments the remote queue 500 may be the same or similar to the remote queue 323 of FIG. 3 . Moreover, the order of the fields of FIG. 5 is for illustrative purposes and it is envisioned that these fields may be reshuffled as desired. The remote queue 500 may be maintained on a recipient data site (such as the receiver site 304 of FIG. 3 ).
In an embodiment, the remote queue 500 stores data associated with a successfully received file, which needs to be installed into the backend version control system at the recipient site. Accordingly, in certain embodiments, the remote queue 500 may include two parts. First, meta data ( 501 ) which may be stored in the database (such as the database 316 of FIG. 3 ). Second, the physical data which may be stored on a disk, for example (such as the mass storage 114 of FIG. 1 and/or the RCS 318 of FIG. 3 ). The physical data may be stored in a buffer space until it can be installed. The meta data may be stored in a table in a database and contain information about the transferred data such as the origin site ( 502 ), checksum(s) ( 504 ), predecessor information ( 506 ), size ( 508 ), and the like.
The remote queue 500 may also include two timestamps ReadTime 510 and CompleteTime 512 that may be utilized in recording when a job was started and when it was done. This helps in gathering performance statistics as well. In an embodiment, a primary advantage is that the remote queue 500 may be reconstructed by reading the table in the database, after the remote installer reboots from a crash, restarts, or otherwise recovers from a power loss. The remote queue 500 may also include a priority field ( 514 ) associated with order of installation for each job.
When installing a received file, a file installer (such as the file installer 332 of FIG. 3 ) accesses the remote queue 500 on periodic basis and retrieves information regarding a new job. In an embodiment, the remote queue 500 is polled every ten (10) seconds. It is however envisioned that more or less frequent polling may be chosen depending on the quality of the communication channels, system performance, or other relevant information whether determined externally or dynamically through feedback regarding system performance. The queued jobs may be popped out in the order of priority (and installed likewise). If the installation is unsuccessful, the job may be marked as incomplete in the database table, and an attempt counter 516 may be incremented. Also, a next attempt time field 518 may be set to the next slot. Such an implementation can provide exponential back-off and optimizes the usage of system resources including the file descriptors, memory, and the like.
In an embodiment, it is envisioned that exponential back-off may be a very effective technique for managing multiple thread and/or processes contending for shared resources. In particular, exponential back-off allows any thread and/or process to use some resource for a given time, without being able to release the resource in the defined amount of time. The resource will then be released irrespective of whether the process has finished its task successfully. As a result, all the processes waiting for a given resource will be provided with a fair chance to utilize the resource of interest. If the process that has been allocated the resource cannot finish its task in the allocated time due to any reason such as wait for other unavailable resource, system not responding, and the like, the process will release the allocated resource back to the pool and reclaim it when the process believes it can use it again. If the process is not successful in finishing its task utilizing the reallocated resource again, the process will release the resource again, but will reclaim it after waiting for a longer time period than the previous wait time. Accordingly, the process waits longer and longer each time to reclaim a resource, resulting in back-offs from the resource in an exponential like manner. In an embodiment, the process will eventually either finish successfully or time out. This will ensure that other successful processes do not suffer from unfairness and/or starvation.
Therefore, in accordance with certain embodiments of the present invention, the procedure for receiving a file at a recipient site is independent of installing the file on the recipient site. This bifurcation is envisioned to yield better performance, be more tunable, provide improved control, and allow for load balancing (for example, among distributed systems). Also, some embodiments of the present invention address the problems associated with keeping live data on a particular site, spoke, or a domain, in sync with the data on multiple remote spokes in real-time. In a user community distributed across a country or anywhere in the globe, the need arises to have select data be available on any site at any time. Embodiments of the present invention provide users access to the latest version of the data as soon as it is released into the system from any site. Therefore, there should not be a need to wait for the new data until there is a batch update or a nightly synchronization, for example.
Additionally, if one of the remote sites is down or cannot accept external data, the systems provided in accordance with some embodiments of the present invention can temporarily store (e.g., buffer or queue) the new data until the remote spoke is back on-line. Further, the system can work with the configuration control mechanisms (CCM) on each site and can install the new data into the CCM on the remote sites. Additionally, the system can work with meta data (if any) in, for example, the backend database storage, so that the user commands or interfaces to the database function accurately during any synchronization process.
The foregoing description has been directed to specific embodiments. It will be apparent to those with ordinary skill in the art that modifications may be made to the described embodiments, with the attainment of all or some of the advantages. For example, the schemes, data structures, and methods described herein can also be extended to other applications. More specifically, any type of data may be transferred utilizing embodiments of the present invention. Also, the transfer systems provisioned in accordance with embodiments of the present invention may be configured depending on a specific project, data types, number of users, size of files, location of users, and the like. Further, the routines described herein may be implemented utilizing Java programming techniques. Therefore, it is the object of the appended claims to cover all such variations and modifications as come within the spirit and scope of the invention. | 4y
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FIELD OF THE INVENTION
The present invention relates generally to portable supports for power drills, and particularly, to an inverted power drill support that is height adjustable, allows drilling operations at various angles, provides a leverage advantage that reduces operator effort, and minimizes risks to the operator using the power drill support.
BACKGROUND OF THE INVENTION
A well known type of power drill apparatus, the drill press, is commonly used to accurately guide a drill bit through a motion range.
Most commonly available drill presses are of the type in which the drill is lowered into contact with the workpiece. Only a limited number of drill presses can perform a drilling operation on an overhead or overlying surface, that is, a surface which is only readily accessible from a position directly underneath.
Prior art inverted drill presses, while facilitating drilling operations on overlying surfaces, are often cumbersome and not readily mobile. Moreover, many of these prior art presses require the operator to be positioned close to the power drill support and thus, beneath the drilling site. Such a requirement increases the risk of injury to the operator from falling metal particles dislodged during the drilling process.
These problems are particularly significant in the context of drilling operations underneath a vehicle. More particularly, the prior art drill presses have not been well suited for use in the installation of trailer hitches or similar devices on automobile frames.
Due in part to the substantial design changes which have occurred in the automobile industry over the past decade, today's vehicles are often unable to accommodate a temporary multi-clamp hitch that would attach directly to the vehicle bumper. Therefore, the installation of a bolt-on trailer hitch, or similar device, on such late model vehicles becomes necessary. The installation of a bolt-on hitch generally requires overhead drilling, and can pose significant problems.
For instance, if a hydraulic lift is not available, the installer must use jacks or ramps for raising an end of the vehicle. In either case, the installer must be positioned beneath the partially elevated vehicle, thereby increasing the hazards associated with the installation operation. Moreover, because the elevated vehicle is at an angle relative to the floor surface, not only must the operator generate enough vertical force so that the drill bit penetrates the vehicle frame, but the power drill must be held at an angle so that the bit is perpendicular to the frame surface. Applying sufficient force at the proper angle can be awkward and poses a drill control problem for the operator.
Moreover, even if the installer has access to a standard overhead vehicle lift, the available prior art overhead drill presses require that the operator be positioned proximate the drill press during drilling. As previously mentioned, such a location increase the danger with which the drilling operation is conducted since the operator is exposed to the expelled metal fragments of the drilled vehicle frame. Furthermore, as most garage floors are sloped for drainage, the drill bit of a standard inverted drill press will not be perpendicular to the vehicle frame unless the angle of the drill press base is adjusted relative to the floor.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an inverted drill assembly obviating, for practical purposes, the above-mentioned limitations.
In accordance with the broad aspects of the invention, there is provided a portable assembly for supporting and positioning, both vertically and angularly, an inverted power drill relative to a surface of an overlying workpiece. All of the positioning and operating controls of the support assembly are removed from the vicinity of the power drill so as to enhance operator safety.
In accordance with a specific, exemplary embodiment of the invention, the power drill support assembly includes a stable, mobile pedestal positionable along a floor underneath the vicinity of the workpiece. Mounted on the pedestal is an upright standard supporting a power drill carriage for moving the drill toward and away from the workpiece surface. The carriage is pivotally mounted on the standard and the angle of the drill relative to the workpiece is controlled by a tilt lever coupled to the carriage. The carriage includes means for locking the carriage at the selected drill angle.
The carriage further includes a parallel linkage for controlling the motion of the power drill toward and away from the workpiece along a generally linear path. The parallel linkage is actuated by a power drill feed lever actuated by the operator. The power drill feed lever provides a leverage advantage which reduces operator effort requirements.
BRIEF DESCRIPTIONS OF THE DRAWINGS
To facilitate an understanding of the invention, the accompanying drawings illustrate a preferred embodiment. The above and other objects of the invention, as well as the features thereof as summarized above, will become more apparent from the following description when taken in conjunction with the accompanying drawings in which:
FIG. 1 is a perspective view of an inverted angle drill in accordance with a preferred embodiment of the present invention;
FIGS. 2A and 2B are side elevation views, partly in cross section, of a height adjustment latch mechanism forming part of the apparatus of FIG. 1, with the mechanism shown in the latched configuration in FIG. 2A and unlatched in FIG. 2B;
FIG. 3 is a side elevation view of a handle switch mechanism comprising part of the apparatus of FIG. 1;
FIGS. 4 and 5 are side elevation views showing details of a power drill support carriage in accordance with the preferred embodiment;
FIG. 6 is an end elevation view, partly in cross section, of the power drill support carriage as seen along the plane 6--6 in FIG. 4; and
FIG. 7 is a top plan view, partly in section, of the power drill support carriage as seen along the plane 7--7 in FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Turning now to the drawings, there is shown a portable assembly 10 for supporting and positioning an inverted power drill 12 relative to an overlying workpiece 14, for example, the frame of an automobile, having a surface 16. The power drill carries a drill bit 18. The assembly 10 includes, generally, a pedestal 20, an upright standard 22 mounted on the pedestal and an adjustable carriage 24 supporting the inverted power drill. The pedestal includes radially-extending feet 26 providing a wide, stable base. Two of the feet 26 have casters or rollers 28 at their outer ends to facilitate moving the portable assembly 10.
Welded to the pedestal 20 is a vertical receptacle 30 for receiving the lower end of the upright standard 22. The standard and the receptacle may be fabricated of tubular steel stock so dimensioned that the standard 22 fits closely within the receptacle 30. The vertical receptacle 30 and the lower portion of standard 22 are round to allow rotational movement of the carriage 24. A threaded fastener 31 inserted through a hole in the pedestal centered under receptacle 30 engages threads (not shown) at the bottom of standard 22 and prevents accidental separation of the standard 22 and the pedestal 20. Removal of threaded fastener 31 allows standards of various heights to be interchangeably used in the support of assembly 10 to accommodate a variety of drilling environments.
The carriage 24 is mounted, in a manner to be described, on a square tube 32 slidably received by, and adjustably positionable along, the standard 22. Such vertical adjustment permits the assembly 10 to be used with vehicles of different frame heights or with vehicles elevated to different heights.
The assembly 10 includes a latch mechanism 34 mounted on the tube 32 for securing the tube 32, and therefore the carriage and power drill, at a selected height along the standard 22. The latch mechanism 34 is carried by a pair of side plates 36 welded to and projecting from the lower end of the tube 32. The mechanism 34 consists of a handle 38, pivotally mounted at 40 on the side plates 36, and a generally vertically oriented, narrow plate 42 attached to the handle 38 adjacent the pivot 40. A latch pin 44 secured to the lower end of the plate 42 is adapted to enter any of a plurality of vertically spaced apertures 46 formed in one of the sides of the standard 22. A compression spring 48, interposed between the upper end of the plate 42 and the confronting face of the tube 32, biases the handle and plate counterclockwise (as seen in FIGS. 2A and 2B), that is, to the latching position in which the pin 44 is received by one of the apertures 46 (FIG. 2A).
To adjust the carriage and power drill height, the operator pulls up on the handle 38, causing it and the plate 42 to pivot in a clockwise fashion about the pivot 40, as shown in FIG. 2B, withdrawing the pin 44 from the aperture permitting the operator to slide the carriage and power drill up or down along the standard. Once a new position is reached, the handle 38 is released causing the pin 44, under the bias of the spring 48, to enter another one of the apertures 46 thereby locking the apparatus in place vertically.
The carriage 24 includes a parallel linkage 50 having a bracket 52 comprising a web portion 54 for supporting the power drill and side flanges 56. The parallel linkage 50 includes a first pair of parallel, identical side links 58a, 58b disposed along one side of the standard 22 and a second pair of parallel side links 60a, 60b identical to and parallel to the first pair, adjacent the other side of the standard. One end of each of the link pairs is fastened by pivot pins 62 to a flange 56 of the bracket 52 at spaced apart points.
The carriage 24 also includes a tilt mechanism 70 (FIGS. 4 and 5) for adjusting the angle of the power drill 12 so as to facilitate the orientation of the drill bit 18 perpendicular to the workpiece surface 16. The tilt mechanism includes a tilt control lever 72 having an outer, bifurcated end 74 with grip handles 76 and an inner end 78 mounted on a horizontal pivot shaft 80 rotatable in a sleeve 82 secured to the slidable tube 32. The tilt control lever 72 is thereby movable up and down about a horizontal pivot axis defined by the shaft 80 and sleeve 82.
The inner end of the tilt control lever 72 includes a generally vertical extension 84, perpendicular to the main, bifurcated portion of the lever. A vertical tilt plate 86 is welded along its forward edge to the lever extension 84. It will thus be seen that the plate 86 can be angularly displaced or tilted in its vertical plane about the pivot by moving the tilt control lever 72 up and down. To facilitate unimpeded tilting of the plate, the lever 72 and plate 86 are laterally offset so that the plate clears the standard 22 as it is moved to different angular positions.
A pair of transversely-extending sleeves 88 are welded to the tilt plate 86 adjacent the rear edge of the plate. The sleeves 88 are vertically separated by a distance equal to that separating the link pivot pins 62 on each flange of the power drill support bracket 52.
The other ends of the link pairs 58, 60 are fastened to the tilt plate by pivot pins 90 rotatably received by the sleeves 88 thereby defining a four bar parallel linkage.
The carriage 24 is locked by the operator at a selected angular position by means of a threaded rod 94 terminating in a T-handle 96. The end of the threaded rod passes through a slot 98 in a hinged lock plate 100 and is received by a threaded hole 102 in the tilt plate. A collar 104 welded to the threaded rod clamps the tilt plate 86 against the lock plate 100 upon tightening of the threaded rod by means of the T-handle 96. The lock plate is hingedly attached to the slidable tube 32 by means of a hinge pin 106 on a projecting tab 108 welded to the slidable tube.
The ends of the lower links 58b, 60b attached to the tilt plate 86 have extensions 110 which are joined by a bracket 112 to a drill feed lever 114 having a hand grip 116 at its outer extremity. Accordingly, up and down movement of the feed lever 114 causes the power drill 12 to move up and down in parallel fashion through the action of the parallel linkage 50 pivoting on the tilt plate. Although the parallel linkage causes the power drill to describe an arc as it is moved up and down by the feed lever, it will be appreciated that for the small displacements involved in drilling through an automobile frame member, that motion is linear for all practical purposes. The length of the feed lever 114 is considerably greater than that of the portion of the side links 58a, 58b between the pivot pins 62 and 90. Accordingly, a substantial mechanical advantage is provided so as to reduce operator effort.
The feed lever 114 includes, under bracket 112, an air valve 118 for controlling the energization and direction of rotation of the power drill 12 via conduits and hoses (not shown) in a manner well known in the art. Actuation of the valve 118 is controlled by a fore-and-aft extending rod 120 pivotally attached to the feed lever by means of a pivot bracket 122, and joined to the air valve through connecting rod 124.
It will be appreciated that the invention described provides a versatile, portable inverted power drill support in which the vertical position as well as the angle of the drill may be easily adjusted so as to permit rapid installation of trailer hitches and the like to automobile frames. All operator manipulated elements, including the levers 72 and 114 and the tilt lock T-handle 96 are well removed from the vicinity of the power drill thereby minimizing risks of injury while using the equipment.
While it will be obvious to those skilled in the art that the invention is susceptible of various modifications and alternative constructions, one specific, preferred embodiment thereof has been shown in the drawings and described in detail. It should be understood, however, that there is no intention to limit the invention to the specific form illustrated and described, but on the contrary, the intention is to cover all modifications, alternative constructions and equivalents falling within the spirit and scope of the invention as defined by the appended claims. For example, it will be obvious that the drill 12 may be either pneumatically or electrically powered. | 4y
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CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 60/989,604, filed on Nov. 21, 2007, the entire content of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates generally to high chair devices. More particularly, the present invention relates to accessories for a high chair.
BACKGROUND OF THE INVENTION
[0003] As most parents of small children are aware, it is a common occurrence for children and toddlers seated at high chairs to drop food, utensils, toys, and other articles to the floor. Moreover, when a small child is seated at a high chair which is positioned with a table in front of it, the child will most often drop or toss the food or other articles off the side or rear of the high chair. For reasons of cleanliness and prevention of illness, most parents and guardians will not give a utensil or toy, and certainly not a child's food, back to the child after it has fallen onto the floor without having first cleaned the article. This is especially true in a restaurant, where a floor surface is less likely to be clean because of the large amount of foot traffic and potential dirt and bacteria. Furthermore, it may be more difficult to sanitize or replace a child's utensil or other article when in a restaurant.
[0004] Accordingly, it may be desirable to prevent a child's food, utensils, toys, or other articles from falling to the floor when the child is seated in a high chair.
SUMMARY OF THE INVENTION
[0005] Aspects of embodiments of the present invention include a high chair net assembly for preventing a child's food, utensils, toys, or other articles from falling to the floor and holding such articles at a height where the child can recover them. Another aspect of embodiments of the present invention is a high chair net assembly constructed from a safe, durable, and washable material. Yet another aspect of embodiments of the present invention is a high chair net assembly that is lightweight and portable so that it can easily be carried to and used at a restaurant. Still another aspect of embodiments of the present invention is a high chair net assembly that is configured to be attached to a high chair of a type commonly found in a restaurants.
[0006] According to one embodiment, the above and other desirable aspects of the present invention may be carried out by a high chair net assembly including a net, and at least one coupling device configured to couple the net to a high chair.
[0007] In one embodiment, the high chair net assembly further includes at least one folding mechanism. In one embodiment, the at least one folding mechanism is moveable from a folded position to an unfolded position, and the net surrounds at least a portion of a periphery of the high chair when the at least one folding mechanism is in the unfolded position.
[0008] According to another embodiment, a high chair net assembly includes: a net configured to surround at least a portion of a periphery of a high chair; at least one panel configured to at least partially cover at least one side or back of the high chair; and at least one hinge assembly including a first arm and a second arm pivotably coupled to the first arm, the first arm configured to support the at least one panel and having a mechanism for attaching the at least one panel to the high chair, and the second arm configured to support the net.
[0009] According to another embodiment, a method of utilizing a high chair net assembly having a net, at least one coupling device, and at least one folding mechanism includes coupling the net to a high chair via the at least one coupling device, and unfolding the at least one folding mechanism to open the net around the high chair.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The above aspects, and other features and aspects, of embodiments of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
[0011] FIG. 1 is a front perspective view of a high chair net assembly according to an embodiment of the present invention;
[0012] FIG. 2 is a top view of the high chair net assembly of FIG. 1 ;
[0013] FIG. 3 is a front view of the high chair net assembly of FIG. 1 ;
[0014] FIG. 4 is a front view of the high chair net assembly of FIG. 1 , the high chair net assembly shown in a folded position;
[0015] FIG. 5 is a front view of a hinge of a high chair net assembly according to an embodiment of the present invention, the hinge shown in an unfolded position; and
[0016] FIG. 6 is a front view of the hinge of FIG. 5 , the hinge shown in a folded position.
DETAILED DESCRIPTION
[0017] In the following detailed description, certain exemplary embodiments of the present invention are shown and described, by way of illustration. As those skilled in the art would recognize, the described exemplary embodiments may be modified in various ways, all without departing from the spirit or scope of the present invention. Accordingly, the drawings and description are to be regarded as illustrative in nature, rather than restrictive.
[0018] With reference to FIGS. 1-4 , a high chair net assembly 100 includes a net 102 . In one embodiment, the net 102 is constructed from a nylon mesh material. This material is advantageous because it is durable, lightweight, collapsible, and easily cleaned. Alternatively, the net 102 may be constructed of any other suitable material, such as cloth, cotton, or any material which is flexible and washable. Further, the net 102 may be formed from a single piece of material or from several pieces of material sewn or otherwise joined to one another.
[0019] As shown in FIG. 2 , in one embodiment, the net 102 has a substantially semi-circular outer shape and an inner rectangular cut-out sized to match the dimensions of a high chair. The diameter 104 of the substantially semi-circular outer edge is approximately 40 inches (102 centimeters). The substantially rectangular cutout has a width 106 of approximately 15 inches (38.1 centimeters) and a depth 108 of approximately 12 inches (30.5 centimeters). Alternatively, the net 102 may have three substantially rectangular sides joined by two substantially triangular portions, or any other suitable shape. The dimensions of the net 102 may be varied, of course, without departing from the present invention. A large net 102 will prevent more articles from falling to the floor. However, a small net 102 may be more easily used in small spaces and may be more portable.
[0020] With further reference to FIGS. 1-4 , the high chair net assembly 100 , in one embodiment, also includes three vertical panels 110 . In one embodiment, the vertical panels 110 are formed from cloth. However, the invention is not limited thereto, and other suitable materials, including fiberglass, aluminum, wood, nylon mesh, and/or a plastic, may be used to form the vertical panels 110 . While the embodiment shown includes three vertical panels 110 , the high chair net assembly may alternatively include any other desired number of vertical panels 110 , such as one or two. Additionally, a single vertical panel 110 having more than one side may be used instead of three separate vertical panels 110 .
[0021] The vertical panels 110 have lengths that are approximately equal to the dimensions of the three corresponding sides of the substantially rectangular cutout of the net 102 , described above. Further, each of the vertical panels 110 , in the embodiment shown, has a height of approximately nine inches (22.8 centimeters). However, the height of the vertical panels 110 is not crucial to the invention and may be varied as desired. A greater height of the vertical panels 110 will result in the net 102 being closer to the floor. A beneficial height of the vertical panels 110 , according to one embodiment, will allow a child to reach an article resting on the net 102 . Additionally, one or more of the vertical panels 110 may have a different height than one or more other vertical panels 110 .
[0022] As further shown in FIGS. 1-4 , according to one embodiment, the high chair net assembly 100 includes six sleeves 112 . In one embodiment, the sleeves 112 are formed from cloth. The material of the sleeves 112 should be a flexible material because the sleeves 112 will be folded during use. Alternatively, each sleeve 112 may be formed as two separate segments that are separated near a region where the sleeve 112 is folded. In one embodiment, the sleeves 112 are open on an end nearest the high chair. Alternatively, the sleeves 112 may be open on both ends. Also, each sleeve 112 may be formed from a single layer of material, two stacked layers of material, or a tubular segment of material.
[0023] The sleeves 112 , according to one embodiment, have a length of approximately 24 inches (70 centimeters) and a width of approximately three inches (7.62 centimeters). Alternatively, the length and the width of the sleeves 112 may be varied, so long as a supporting member can be inserted into each sleeve 112 . Also, although the shown embodiment of the high chair net assembly 100 includes six sleeves 112 , the high chair net assembly may include any other suitable number of sleeves 112 .
[0024] With further reference to FIGS. 1-4 , the high chair net assembly 100 includes one or more attachment members 120 configured to attach the net 102 to a high chair. In the embodiment shown in FIGS. 1-4 , the attachment members 120 include six hooks 122 . In one embodiment, the hooks 122 are constructed from a plastic material, providing durability, light weight, and low cost. Further, because the hooks 122 will extend to an inner region of the high chair, a plastic material may also provide for safe handling if a child touches the hooks 122 . The hooks 122 may alternatively be constructed from any other suitable material, such as aluminum, fiberglass, or wood.
[0025] According to one embodiment, a width 124 of each of the hooks 122 (i.e. the distance between the two opposite faces), as shown in FIG. 3 , is slightly greater than the thickness of a component of a high chair over which the hooks 122 are placed. In one embodiment, the width 124 of the hooks 122 is approximately one inch (2.54 centimeters), such that the hooks fit snugly over a side rail or back of a typical restaurant-style high chair. Additionally, by constructing the hooks 122 from a material with some elasticity, such as a plastic material, the width 124 can be increased during use to fit more snugly over a component of a high chair.
[0026] As an alternative to the hooks 122 , the attachment members 120 may include any other device known in the art that is suitable for attaching a net to a high chair. For example, the attachment members 120 may include straps, which may, in turn, include hook-and-loop fasteners. Alternatively, the attachment members 120 may include clamps, magnets, set screws, and/or any other suitable device or combination thereof.
[0027] With further reference to FIGS. 1-4 , according to one embodiment, the high chair net assembly 100 also includes one or more folding mechanisms 130 . FIGS. 1-3 show the high chair net assembly 100 in an unfolded (i.e. opened) position. By contrast, FIG. 4 shows the high chair net assembly 100 in a folded (i.e. closed) position. In the embodiment shown in FIGS. 1-4 , the high chair net assembly 100 includes six folding mechanisms 130 , the six folding mechanisms 130 embodied by six hinges 132 .
[0028] The hinges 132 are shown in greater detail in FIGS. 5 and 6 . FIG. 5 shows one of the hinges 132 in an unfolded position, while FIG. 6 shows one of the hinges 132 in a folded position. In one embodiment, the hinges 132 are constructed from a plastic material, providing durability, light weight, and low cost. Alternatively, the hinges 132 may be constructed from any other suitable material, such as aluminum, wood, or fiberglass.
[0029] As shown in FIGS. 5 and 6 , each of the hinges 132 includes a stationary arm 134 , a pivot 135 , and an extending arm 136 . The extending arm 136 is pivotably, or rotatably, coupled to the stationary arm 134 at the pivot 135 . In one embodiment, the stationary arms 134 have a length of approximately 8 inches (20.3 centimeters) and a width of approximately 1.5 inches (3.8 centimeters). The extending arms 136 , in one embodiment, have a length of approximately 10 inches (25.4 centimeters) and a width of approximately 1.5 inches (3.8 centimeters). The widths of the stationary arms 134 and the extending arms 136 are less than the widths of the sleeves 112 .
[0030] Of course, the lengths of the stationary arms 134 and extending arms 136 may vary in alternative embodiments. In one embodiment, the length of the stationary arms 134 should be approximately equal to the height of the vertical panels 110 . As described above, a greater height of the vertical panels 110 will result in the net 102 being closer to the floor. Also, as described above regarding the heights of the vertical panels 110 , the stationary arms 134 may have lengths that vary from one another. For example, if a back of a high chair is at a higher elevation than are sides of the high chair, stationary arms 134 for use with the back may be longer than stationary arms 134 for use with the sides of the high chair. Longer extending arms 136 will result in the net 102 protruding a greater distance from a high chair.
[0031] In one embodiment, the end of each extending arm 136 located at the pivot 135 has a stop 138 . Each stop 138 has a face which butts against the side of the stationary arm 134 opposite the pivot 135 . The angle of the face of the stop 138 controls the maximum angle to which the extending arm 136 will open relative to the corresponding stationary arm 134 . In one embodiment, an angle of approximately 75 degrees is used, but any angle of 90 degrees or less may be used. A smaller angle will result in the ends of the extending arms 136 and the net 102 being closer to a high chair.
[0032] The high chair net assembly 100 is configured to be used with a high chair 150 . The high chair 150 , in one embodiment, is of a style commonly used in restaurants for toddlers and small children. As shown in FIG. 1 , the high chair 150 has a seat 152 and a back 154 . The high chair 150 also has two side rails 156 at or near the top of the high chair 150 which extend from a front to the back 154 of the high chair 150 . Additionally, the high chair 150 has four legs 158 which may be connected by one or more structural beams 160 . As shown in FIG. 1 , the high chair 150 may also include a restraint 162 to keep the child or toddler from falling. The high chair 150 is commonly made from wood, but may also be constructed from aluminum, plastic, or another material or combination thereof.
[0033] In assembly, the components of the high chair net assembly 100 described above and shown in FIGS. 1-6 may be connected to each other in any suitable manner or combination thereof. In one embodiment, for example, each of the vertical panels 110 is sewn to the net 102 . The seam along which the net 102 and each of the vertical panels 110 is connected should remain flexible because this is the region where the high chair net assembly 100 is folded and unfolded. Also, in one embodiment, each of the sleeves 112 is sewn partially to one of the vertical panels 110 and partially to the net 102 . Two of the sleeves 112 are connected to each of the vertical panels 110 , one of the sleeves 112 being located near each end of each of the vertical panels 110 . The sleeves 112 are folded at an angle where the net 102 is connected to the vertical panels 110 .
[0034] In one embodiment, the stationary arms 134 and the extending arms 136 of the hinges 132 are inserted into the sleeves 112 . As a result of this configuration, the extending arms 136 support the net 102 because the sleeves 112 are connected to the net 102 . Also, as shown in FIGS. 1-3 , when the hinges 132 are in an unfolded position, the net 102 will also have an unfolded shape. Furthermore, by inserting the stationary arms 134 into the sleeves 112 , the vertical panels 110 , to which the sleeves 112 are connected, will hold their shape even where formed from a flexible material, such as a cloth.
[0035] Further, in assembly, one or more of the attachment members 120 may be combined with one or more of the folding mechanisms 130 . For example, in the embodiment shown in FIGS. 5 and 6 , one of the hooks 122 and one of the hinges 132 are constructed as a unitary device by forming the hook 122 at the end of the stationary arm 134 of the hinge 132 opposite the end of the stationary arm 134 connected to the extending arm 136 . Alternatively, two or more of the hooks 122 may be combined with one of the hinges 132 , or vice versa.
[0036] In use, according to one embodiment, the high chair net assembly 100 is first attached to the high chair 150 via the one or more attachment members 120 . With reference to FIG. 4 , according to one embodiment, the high chair net assembly 100 is attached to the high chair 150 by placing the hooks 122 onto the two side rails 156 and the back 154 of the high chair 150 . In one embodiment, two of the hooks 122 are attached to each side rail 156 and two of the hooks 122 are attached to the back 154 of the high chair 150 .
[0037] After the high chair net assembly 100 has been attached to the high chair 150 , the high chair net assembly 100 may be opened by unfolding the one or more folding mechanisms 130 . As shown in FIGS. 1-3 , when the hinges 132 are opened by moving the extending arms 136 of the hinges 132 away from the stationary arms 134 via the pivots 135 , the extending arms 136 will also move the sleeves 112 and thereby open the net 102 . Due to the angle of the stops 138 , the extending arms 136 , and therefore the net 102 as well, will open to an angle of approximately 75 degrees relative to the side rails 136 and the back 134 of the high chair 150 . This is beneficial because when the net 102 is supported at an angle of less than 90 degrees relative to the side rails 136 and the back 134 of the high chair 150 , articles dropped by a child and caught by the net 102 will likely come to rest in an area of the net 102 near the high chair 150 , where the articles will be within the child's reach.
[0038] Use of the high chair net assembly 100 has been described above by performing the attaching task before the unfolding task. However, the high chair net assembly 100 may also be utilized by first unfolding the high chair net assembly 100 , and subsequently attaching the high chair net assembly 100 to a high chair.
[0039] Although embodiments of the present invention have been described with reference to a restaurant-style high chair of a type described above and depicted in FIGS. 1-4 , it will be appreciated by individuals skilled in the art that the high chair net assembly 100 according to embodiments of the present invention can be used with other types of high chairs that are known in the art.
[0040] Although the present invention has been described in certain specific embodiments, many additional modifications and variations would be apparent to those skilled in the art. It is therefore to be understood that this invention may be practiced otherwise than as specifically described. Thus, the present embodiments of the invention should be considered in all respects as illustrative and not restrictive, the scope of the invention to be determined by the claims supported by this application and their equivalents, rather than the foregoing description. | 4y
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This is a continuation of co-pending application Ser. No. 602,961 filed on 4/23/84 now abandoned.
BACKGROUND OF THE INVENTION
The field of this invention is directed to industrial heavy duty type swivels which are used in making connection between a load receiving and a hoisting device which will have the freedom to rotate under design tension load conditions. Most swivels heretofore known have involved parts having intricate and extensive machining operations welded or precise press fit connections of the adjoining parts, and which were not necessarily easy to repair or maintain under field conditions.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an industrial type swivel that has been simplified in its construction with a minimal amount of machining of the parts.
A further object of the invention is to provide an industrial swivel wherein the major components are constructed by the investment casting process.
A further object of the invention is to provide an industrial swivel that can be pre-assembled together and safely interlocked, yet can be easily disassembled for maintenance and repair.
In its broadest form, the invention comprises an industrial swivel having an upper connection with a barrel cavity to receive a lower connection having a shank. Pre-assembled upon the shank, prior to its connection into the cavity, is a thrust bearing between upper and lower retention means with a non-threaded means to rotatably interlock the pre-assembly into the barrel of the cavity.
The specific form of the invention is directed to a swivel having an upper connector with a barrel cavity depending therefrom. The cavity has, internally, at least one slot at the bottom connecting with a circumferential groove thereabove. The groove includes adjacent at least one slot at least one detent ledge and an adjoining lock ledge. The lower connector includes a shank having contoured groove below the upper end of the shank. The shank is rotatably retained in the barrel cavity by pre-assembled parts comprising a plug that is rotatably attached at the bottom of the shank. The plug has a flange which has an upper face that abuts a bottom face of the barrel cavity. Above said upper face of the plug flange is an upper lug for each slot. A resilient gasket is provided between said upper face of the plug flange and the bottom face of the barrel cavity. A bushing is positioned co-axially within the plug between the plug and the shank. A thrust bearing is provided above the plug and retained there by a split nut thereabove. The split nut has an interior contour to fit the contoured groove on the shank. A collar surrounds the split nut to retain the split nut there assembled around the shank. The pre-assembled parts are positioned and retained within the barrel cavity by inserting the upper lug or lugs into each slot and forcibly rotating the plug across the detent ledge with the lug thereafter dropping into the appropriate lock ledge.
The location of the detent ledge relative to the bottom surface of each lug is such that the resilient gasket positioned between the upper face of the plug flange and the bottom face of the barrel cavity is of thickness to create a compression force to restrain the lug from jumping the detent ledge and to further create a seal between the upper face of the plug flange and the bottom face of the barrel cavity when in the locked position.
A grease opening and zerk are positioned on one of the barrel for filling the cavity after assembly. In one embodiment, a set screw is provided in the cavity for retaining the plug in the locked position.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of the swivel assembly of this invention.
FIG. 2 is a sectional view taken along the line 2--2 of FIG. 1.
FIG. 3 is a sectional view taken along the line 3--3 of FIG. 1.
FIG. 4 is an exploded view of the connector assembled parts in accordance with this invention.
FIG. 5 is a sectional view of the lower portion of the barrel cavity.
FIG. 6 is an end view taken along the line 6--6 of FIG. 5.
FIG. 7 is a side elevational view of the plug of this invention.
FIG. 8 is a top elevational view of the plug of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Before explaining the present invention, in detail, it is to be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanied drawings, since the invention is capable of other embodiment and being practiced or carried out in a variety of ways. Also, it is to be understood that the phraseology or terminology employed herein is for the purpose for description and not of limitation.
As shown in FIG. 1, the industrial swivel of this invention is generally designated by the numeral 10 and includes an upper connector 12, in this instance, a jaw type having parallel legs 14 and 16 with co-axial openings 18 and 20. The upper connector has, depending therefrom, a barrel portion 22 with a cavity 24. The barrel terminates with a bottom face 26. As best shown in FIG. 3 the bottom of the cavity internally includes at least one or as shown a plurality of slots 28. Each of these slots connects with an internal circumferential groove 30.
As best shown in FIG. 5, the groove 30 includes, around its inner periphery, a detent and lock ledge portion generally designated by the numeral 32, which includes a raised detent surface 34, a lower lock ledge 36 and a vertical stop edge 38.
Referring again to FIG. 1, a lower connector, in this instance a hook 50, only the top portion of which is shown, includes a shank 52. The upper end of the shank includes a contoured groove 54 positioned below the top 56 of the shank, forming a knob 58. The shank 52 is rotatably retained within the barrel cavity by the combination of pre-assembled parts that include a plug 60, as best described in FIGS. 7 and 8. The plug has a flange with an upper face 62 adapted to match the lower face 26 of the barrel. In the assembled condition a resilient gasket 64 is provided between the two faces. The plug has a cylindrical surface 70 with a plurality of bayonet type lugs 72 formed as a part at the top of the plug which provide the interlocking connection with the barrel cavity as hereinafter described. Each lug is formed with a curved or radius surface 73. Also formed as a part of the plug is a transverse opening 74 for receiving a handle or other instrument to aid in rotating and locking the plug in place. A bronze bushing 78 is provided between the plug and shank 52 as a bearing surface.
Above the plug is situated a thrust bearing 80 which is retained in the assembled position by a nut which is split into two portions 82 and 84 (See FIG. 2), the nut having a contoured surface 86 and 88 which will match or fit into the contoured surface 54 of the shank 52. Flat surface 85 under load condition transmits the forces through the split nut to the shank through knob 58. Thus, there is very little outward force against cylindrical collar 90 which is positioned as a slip fit around the split nut to retain said parts 82 and 84 in the assembled condition as shown.
Also formed as a part of the barrel cavity is a threaded set screw opening 100 which is positioned such that one edge of the hole is in line with the detent shoulder 34. (See FIGS. 3, 5 and 6). A set screw 102 is provided therefor.
An opening 108 is provided in the upper part of the barrel cavity which includes an enlarged recess portion 110 with a standard grease zerk 112 press fit or threadably closing the opening 108 for supplying lubricant to the cavity 24.
The exploded view of FIG. 4 describes an upper eye connector 110 having a barrel and cavity 112 to receive the lower connector, in this instance a single eye 114 having a shank 52 and the heretofore similarly numbered assembled parts shown exploded.
In the assembly of the swivel the plug 60 and its associated bushing 78 are first positioned over the shank 52 at the bottom thereof. Gasket 64 is then placed upon the upper face 62. Thrust bearing 80 is then positioned atop the plug 60 and split nut halves 82 and 84 are then assembled with the contoured portions 86 and 88 matching the surface 54. Thereafter the sleeve 90 is positioned around the split nut to retain the parts in the assembled conditions. The parts then placed into the cavity 24 with the lugs 72 of the plug 60 being inserted upwardly through appropriate slots 28. The necessary applied torque to interlock the plug with the cavity occurs by the use of a spanner wrench which may be inserted into opening 74 formed on the flange of the plug 60. By combining upward compression of the gasket 64 and rotation of the plug, the radius surfaces 73 ride over detent ledges 34 until the lug is opposite and resting in the lock ledge 36 with any further rotative movement being restrained by the stop edge 38. To test whether or not the plug has been properly positioned within the cavity, a set screw 102 is then threaded within opening 100 as best shown in FIG. 3. In the event there has not been sufficient rotation of the plug, the set screw will not enter into the cavity advising that further rotation is necessary. Thereafter the cavity is lubricated by being filled with grease through zerk type valve 112 utilizing a common grease gun. Disassembly of the unit can be achieved by a reversal of the steps described above.
Although only two types of connection combinations are shown, i.e., an upper jaw and lower hook (FIG. 1) and upper eye and lower eye (FIG. 4), it is to be understood that other combinations are inclusive of the invention including but not limited to an upper jaw/lower jaw, upper jaw/lower eye, upper eye/lower jaw and upper eye/lower hook. | 4y
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FIELD OF THE INVENTION
[0001] This invention relates to construction elements suitable for use in constructing internal or external walls, ceilings, roofs, floors and the like—where reduction of transmission of sound from one side to another is important.
BACKGROUND TO THE INVENTION
[0002] The sound transmission loss of a wall partition, ceiling, roofs or floor are determined by physical factors such as mass and stiffness. A complex interplay of factors works to prevent or allow the transmission of sound through surfaces. In a double layer assembly, such as plasterboard on wood or metal framing, the depth of air spaces, the presence or absence of sound absorbing material, and the degree of mechanical coupling between layers critically affect sound transmission losses.
[0003] The mass per unit area of a material is the most important factor in controlling the transmission of sound through the material. The so-called mass law is worth repeating here, as it applies to most materials at most frequencies:
[0000] TL=20 log 10 (m s f)−48. where: TL=transmission loss (dB)
m s =mass per unit area (kg/m 2 )
f=frequency of the sound (Hz)
[0007] Stiffness of the material is another factor which influences TL. Stiffer materials exhibit “coincidence dips” which are not explained by the above mass law. The coincidence or critical frequency is shown by:
[0000]
f
c
=A/t
where: A is a constant for a material
t is the thickness of the material (mm)
[0010] There are other factors in wall, roof, ceiling & floor design such as the mass-air-mass resonance, which also affect transmission loss at different frequencies.
[0011] Generally, relying only on the mass law to achieve a specific TL results in a thick wall, ceiling or floor construction, which reduces usable floor area and ceiling height in an apartment dwelling. Attempts to avoid those coincidence dips noted above appear only to increase transmission loss slightly, if at all. Generally only very expensive and labour intensive solutions give an acceptable transmission loss. Building regulations are becoming more strict while more apartment blocks are being constructed, with cost being a pre-eminent factor.
[0012] The Sound Transmission Loss of a dividing structure separating two spaces varies with frequency. If the structure has a degree of stiffness, incident acoustic energy causes the structure to vibrate which re-radiates the acoustic energy on the other side of the structure. Low frequency re-radiation is mainly controlled by the structure stiffness. At about an octave above the lowest resonance frequency of the barrier, the mass of the structure takes over control of the re-radiation and dominates the sound reduction performance, and the mass law (above) indicates that doubling the mass of the structure increases the structure's noise attenuation performance by approximately 6 dB.
[0013] High frequency incident acoustic energy causes ripple-, or bending-waves of the surfaces of the structure. Unlike compression waves, the velocity of bending waves increases with frequency. Every ‘stiff panel construction’ has a critical or coincidence frequency which considerably reduces the Sound Transmission Loss of structural panel construction.
[0014] A common coincidence frequency occurs between 1000 & 4000 Hz and is caused by the bending wave speed in the material equaling the speed of sound in the medium surrounding the panel (in this case air). In this frequency range the waves coincide and reinforce each other in phase, greatly reducing the noise reduction performance of the panel at approximately the critical frequency.
[0015] The present invention seeks to ameliorate one or more of the abovementioned disadvantages of known methods of increasing TL such as higher cost, mass & reduced available space.
SUMMARY OF THE INVENTION
[0016] According to one aspect of the present invention there is provided an acoustic laminate suitable for use in wall, floor and ceiling assemblies and other dividing structure assemblies, the laminate including: a viscoelastic acoustic barrier being in the form of discrete, spaced apart sections or a continuous layer; and a construction panel, the barrier affixed to one or more panel faces of the construction panel.
[0017] Preferably the construction panel is plasterboard, medium-density fibreboard, plywood, fibre-cement sheeting or timber.
[0018] Throughout this specification, “construction panel” is to be taken to include those panels constructed from fibreglass, composites such as carbon fibre, sheets used in domestic construction of walls, glass-reinforced plastics, plasterboard, medium-density fibreboard, plywood, fibre-cement sheeting or timber. Excluded from the definition are steel sheets, aluminium, C-beams, I-beams, structural supports and the like. Furthermore, “panel” is to be taken to include a panel having contours or curvature such as for example, sinusoidal, or of course completely flat.
[0019] Preferably the construction panel is affixed to the viscoelastic acoustic barrier layer by adhesive.
[0020] Preferably the viscoelastic acoustic barrier is poured onto the construction panel and cures on the panel, bonding to the panel during curing.
[0021] Preferably the viscoelastic acoustic barrier layer is affixed to the construction panel in strips along an axis parallel to respective panel faces.
[0022] Preferably a matrix of viscoelastic pads are affixed to the construction panel across respective panel faces.
[0023] Preferably a second layer of construction panel is affixed to an outer face of the viscoelastic barrier or strips or pads in order to provide a three-layer laminate, for captive-, or constrained-layer damping-type effect.
[0024] Preferably the viscoelastic acoustic barrier layer has a density within a range of 1000 kg/m 3 to 3000 kg/m 3 .
[0025] Preferably the viscoelastic acoustic barrier layer has a surface density of approximately 2.5 kg/m 2 .
[0026] Preferably the viscoelastic acoustic barrier layer has a thickness below 6 mm.
[0027] Preferably the viscoelastic acoustic barrier layer has a thickness of 1.7 mm.
[0028] Preferably the viscoelastic acoustic barrier layer has a density is 1470 kg/m 3 .
[0029] Preferably the viscoelastic acoustic barrier layer is a polymeric elastomer impregnated with material which in preferred forms is a particulate material.
[0030] Preferably the filler material is calcium carbonate.
[0031] Preferably the viscoelastic acoustic barrier layer is faced on one side with a nonwoven polyester of thickness approximately 0.05 mm.
[0032] Preferably the viscoelastic acoustic barrier layer is faced on the other side of the viscoelastic barrier or strips or pads by an aluminium film reinforced with polyester as a water barrier.
[0033] Preferably the viscoelastic acoustic barrier layer has a Young's Modulus of less than 344 kPa.
[0034] Preferably the acoustic laminate is incorporated into a wall structure utilising staggered studs and a cavity filled with polyester batts or other sound absorptive material.
[0035] Preferably the viscoelastic acoustic barrier layer is in the form of a composition which includes water, gelatine, glycerine and a filler material.
[0036] Preferably the composition includes:
5-40 wt % water 5-30 wt % gelatine 5-40 wt % glycerine; and 20-60 wt % filler material.
[0041] Preferably the composition includes 1 to 15 wt % of a group II metal chloride such as for example calcium chloride or magnesium chloride.
[0042] Preferably the composition includes 2 to 10 wt % magnesium chloride.
[0043] Preferably the composition further includes 0.5 to 7 wt % starch or gluten.
[0044] Preferably the starch is provided from the addition of cornflour to the composition.
[0045] Preferably the filler material is a non-reactive material with a high density.
[0046] Preferably the density is greater than 1 g/cm 3 .
[0047] Preferably the density of the filler material is approximately 2.0 to 3.0 g/cm 3 .
[0048] Preferably the filler material is chosen from any non-reactive material with a high density such as for example barium sulphate or KAOLIN.
[0049] Preferably the composition includes:
10-25 wt % water 5-20 wt % gelatine 10-25 wt % glycerine; 40-60 wt % filler material; 1-10 wt % magnesium chloride; and 0.5-3 wt % starch;
[0056] Preferably the composition further includes constituents such as for example ethylene and/or propylene glycols; polyvinyl alcohols; deodorisers; anti-oxidants and/or fungicides.
[0057] Preferably a wall construction is provided, incorporating additional layers of construction panel are provided, affixed to staggered studs.
[0058] Preferably the a wall construction is provided, which includes absorbent material in the form of polyester batts.
DESCRIPTION OF PREFERRED EMBODIMENT
[0059] In order to enable a clearer understanding of the invention, drawings illustrating example embodiments are attached, and in those drawings:
[0060] FIG. 1 is a schematic representation of a reference wall (typical of current construction method) used in testing to give a benchmark for measured results;
[0061] FIG. 2 is a schematic representation of a wall constructed in part using components of a preferred embodiment of the present invention;
[0062] FIG. 3 is a graph showing results of benchmark transmission loss testing of the reference wall shown in FIG. 1 (an STC60 curve is superposed on the test results);
[0063] FIG. 4 is a graph showing results of transmission loss testing of the wall shown in FIG. 2 (an STC63 curve is superposed on the test results); and
[0064] FIG. 5 is a graph showing graphs in FIGS. 3 and 4 superposed on similar axes;
[0065] FIG. 6 is a graph showing expected coincidence effects of prior art stiff panels;
[0066] FIG. 7 shows Transmission Loss (TL) test results of a reference wall of the prior art displaying coincidence dip effects;
[0067] FIG. 8 shows TL test results of a wall treated with preferred embodiments of the present invention, showing the much reduced coincidence dips, if detectable at all;
[0068] FIG. 9 shows TL test results of a wall treated with another preferred embodiment of the present invention—ie spaced viscoelastic strips (an STC curve is superposed on the results, and corrected data is also shown in broken line);
[0069] FIG. 10 shows the composition of the reference wall tested in FIG. 9 ;
[0070] FIG. 11 shows TL test results of a wall treated with yet another preferred embodiment of the present invention—ie viscoelastic pads spaced on a matrix (an STC curve is superposed on the results, and corrected data is also shown in broken line);
[0071] FIG. 12 shows the composition of the reference wall tested in FIG. 11 .
[0072] Referring to FIG. 1 there is shown a reference wall generally indicated at 1 . The reference wall is a composite wall consisting of two layers of 13 mm thick fire rated plasterboard directly secured to 64 mm, 0.75 mm steel studs on one side. The wall is wholly repeated in mirror image about a centreline extending between the studs, with a 20 mm gap separating the studs. An infill cavity insulation of 50 mm glasswool 11 kg/m 3 is located between one set of the steel studs.
[0073] A composite wall assembly utilising a preferred embodiment of the present invention is shown at FIG. 2 item 20 . The composite wall assembly includes a laminate assembly 12 including a layer of 13 mm high density plasterboard 14 , adhered to one face of a centre lamina of 2.5 kg loaded polymeric elastomer shown at 16 , which is itself on its other side adhered to a 13 mm standard density plasterboard 18 . The laminate assembly 12 is affixed to 64 mm, 0.6 mm thick steel studs 22 . A cavity 24 is provided, filled on one side with 50 mm thick 48 kg/m 3 polyester insulation batts 26 . On the other side of the cavity 24 , studs 23 are provided, the studs 23 being staggered from studs 22 . Affixed to the studs 23 is a laminate assembly 13 , a mirror image of the laminate assembly 12 .
Experimental Data Utilising Preferred Embodiments of the Present Invention
[0074] A reference wall and a composite wall, each in accordance with the above descriptions and Figures were constructed, and their sound transmission performance was tested. A +1.OdB correction was applied during testing to the reference wall to align its glasswool performance with that of the composite wall. The composite wall utilised 48 kg/m 3 and the reference wall used 1 lkg/m 3 glasswool to infill one side of the cavity.
[0000]
TABLE 1
Comparison Results of the Testing Conducted.
De-
scrip-
⅓ Octave Band Centre Frequency
tion
100
125
160
200
250
315
400
500
630
Com-
45
45
48
50
53
56
57
59
61
posite
Wall
Refer-
37
42
44
47
51
51
55
58
61
ence
Wall
Im-
8
3
4
3
2
5
2
1
0
prove-
ment
De-
scrip-
⅓ Octave Band Centre Frequency
tion
800
1000
1250
1600
2000
2500
3150
4000
5000
Com-
64
66
67
67
68
70
73
77
78
posite
Wall
Refer-
62
64
66
68
64
61
64
64
64
ence
Wall
Im-
2
2
1
−1
3
9
9
13
| 14
prove-
ment
[0075] FIGS. 3 , 4 and 5 show the tabulated results graphically.
[0076] The table above and the graphs show the improvement in acoustic performance that occurs in the nominated frequency regions due to the addition of a lamina of loaded polymeric elastomer 16 , surface density of 2.5 kg/m 2 , between a sheet of 13 mm high-density plasterboard 14 and a sheet of 13 mm normal density plasterboard 18 . Normal experience teaches that a very small improvement of performance in a so-called coincidence dip frequency region (2500 Hz in this case) can occur where plasterboards of differing densities are adhered together. This improvement is normally only of the order of 2 to 3 dB. However, the performance gain in this experiment for the composite wall assembly 20 is 9 dB, with significant gains in performance occurring above this frequency.
[0077] The combined graph ( FIG. 5 ) and table shows an improvement in the frequency regions of 100 Hz to 400 Hz and from 2000 Hz to 5000 Hz.
[0078] When the concept of Acoustic Performance Index is applied to the composite wall assembly 20 ( FIG. 2 ), the score is extremely high. Acoustic Performance Index takes into account the cost of the wall compared to its acoustic performance and to the thickness of the wall and the floor space cost. Thickness is a very important consideration as floor space in a typical apartment is AU$6000 per square metre. The composite wall assembly 20 is only 206 mm wide and has an acoustic performance that can only be matched by expensive wall systems which are 280 mm wide or more. The composite wall system has a high Acoustic Performance Index of R w greater than or equal to 55.
[0079] The combination of the construction panel and viscoelastic barrier provide an unexpected synergy. It would be expected that adding a very thin layer of dense material would only provide a small benefit according to the mass law. For example, at 1250 Hz, increasing the mass by 6 kg/m 2 , (as we have shown above in the testing) we are expected to produce a gain in transmission loss of 2 dB (see Also FIG. 6 ). However, in the testing above, at that frequency, we see TL gain of 21 dB.
[0080] Furthermore, the expected coincidence dip does not eventuate. We would have expected that the change in stiffness would have given us a change in transmission loss of 1.6 dB at 2500 Hz. However, we demonstrated at that frequency, a change of 18 dB.
[0081] By affixing viscoelastic material to construction panel in the form of plasterboard the panel resonance at low frequencies was reduced and stiff panel ‘Coincidence effects’ were greatly reduced at higher frequencies, especially the frequencies at which the ear is most sensitive.
[0082] Other embodiments have been tested: In one embodiment, strips of viscoelastic material covering 25-50% of the panel surface were affixed to the stiff construction panel. The strips were paced by air gaps which formed small voids of less than 4 mm thickness. The resulting damping is apparently as effective as having a full sheet of viscoelastic barrier material on the construction panel, in the sense that shear strains within the viscous-elastic material are still induced which greatly reduces or eliminates the stiff panel construction ‘Coincidence effect’ in the band width 1000-4000 Hz, which is the ear's most sensitive region.
[0083] It is believed that the small spaced air gaps (2-4 mm in thickness) between the construction panels, spaced also between viscoelastic strips or pads appear to act the same way as the actual viscoelastic material. That is, they do not allow the bending wave generated in the panel to reach the speed of sound in the medium surrounding the panel and thus avoid coincidence dips and phase reinforcement.
[0084] It should be noted that shear strains in the viscoelastic treatment actually transform bending waves into heat energy which is noiseless.
[0085] Advantageously, preferred embodiments such as for example that shown at FIGS. 10 and 12 of this invention function via the following mechanism:
Most rigid materials will be sympathetic to vibration at one or more frequencies, and damping materials are an efficient and effective means to control vibration and structure-borne radiated noise. ‘Damping’ is the energy dissipation properties of a material or system under cyclic stress, and damping vibration can significantly reduce the creation of secondary noise problems.
[0088] With the above two paragraphs in mind, the specially formulated non slip viscoelastic strips or pad matrix situated on the construction panel are in contact with the construction panel effectively increasing the vibrations' decay rate. Decay rate is the speed in dB/second at which the vibration reduces after panel excitation has ceased—the higher the decay rate, the better the acoustic performance.
[0089] By applying viscoelastic barrier material in strips and pads to construction board in the form of plasterboard the panel resonance at low frequencies was reduced and ‘Coincidence effects’ were also substantially eliminated.
[0090] Although not shown in the drawings, a method of adhering the construction panel and viscoelastic barrier together has shown excellent adhering properties, and that is to utilise a pouring head which pours a hot or warm viscoelastic composition directly onto the construction board. The composition cools and then grips the face of the board. This may be used to make sandwiches of the compound, ie a second layer of construction board on to an upper surface of the cooling or curing composition.
[0091] Further experiments have been conducted on other preferred embodiments:
[0092] In one embodiment, a wall was constructed as shown in FIG. 10 , starting on the outside: 13 mm standard plasterboard panel 114 ; viscoelastic barrier 116 in strips 50 mm wide, spaced at 50 mm intervals along the panel 114 ; 13 mm standard plasterboard panel 118 ; 64 mm staggered studs 122 in 90 mm track; 20 kg/m 3 polyester batt 126 , 13 mm standard plasterboard panel 115 ; viscoelastic barrier in strips 50 mm wide 117 , spaced at 50 mm intervals; 13 mm standard plasterboard panel 119 . This wall underwent TL testing and the results are shown at FIG. 9 . Only a slight coincidence dip occurs at 1000-4000 Hz. Overall, the STC and corrected transmission loss data are unexpectedly high for this type of construction.
[0093] Similarly, a wall constructed as shown in FIG. 12 has a plurality of 50 mm viscoelastic strips 216 spaced with a 150 mm gap between each. The TL results appear at FIG. 11 and they seem very similar to those shown in FIG. 10 , the only difference being the spacing between the viscoelastic strips. These results show the mechanism of the trapped air apparently working as a viscoelastic medium which reduces the buildup of transverse waves in the panel, without the mass or expense of an actual viscoelastic medium. Again, the STC and corrected transmission loss data are unexpectedly high for this type of construction.
[0094] Some wall constructions do not include any absorptive batt material, and the results appear to be better than similar walls without absorptive batts.
[0095] A feature of a preferred embodiment of the present invention will become better understood from the following example of a preferred but non-limiting embodiment thereof.
EXAMPLE
[0096] 100 g of water together with 100 g of glycerine and 10 g of starch was mixed and then heated to a temperature of 85° C. 80 g of gelatine and 20 g of magnesium chloride was then dissolved into the mixture and a gel was formed. 310 g of barium sulphate was then added to the gel providing a composition with good flexibility, elasticity, tensile strength, and density with good film forming properties. The composition had the following composition by weight:
16% water; 16% glycerine; 1.5% starch; 13% gelatine; 3.5% magnesium chloride; and 50% barium sulphate.
[0103] The composition was then extruded into a flat sheet and bonded onto an aluminium film and then brought down to room temperature whereby the composition cured to form a sheet of composite material of 4 mm in thickness that showed excellent sound dampening properties.
[0104] Finally, it is to be understood that various alterations, modifications and/or additions may be incorporated into the various constructions and arrangements of parts without departing from the spirit or ambit of the invention. | 4y
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BACKGROUND OF THE INVENTION
The invention concerns a columnar shaped piece comprising a thermoplastic matrix with ancillary pieces of a non-creeping hard material embedded therein and cemented by the plastic matrix.
A columnar shaped piece of the aforesaid type is generally known. The ancillary pieces embedded therein and cemented by the plastic matrix consist of essentially spherical mineral dyes. They provide the piece with color and have only a very slight effect on the piece's mechanical properties, especially its bending resistance.
A method is known for the manufacture of columnar shaped pieces wherein a thermoplastic is melted in an extruder, blended with ancillary pieces of non-creeping material, introduced into a mold and shaped into a piece therein, and solidified by cooling. The ancillary pieces in this method are particles of pigment. They dictate only the color of the resulting columnar-shaped piece.
SUMMARY OF THE INVENTION
A principal object of the present invention is to provide a columnar shaped piece that differs from the known piece of this type due to its improved mechanical properties and especially to its improved bending resistance.
A further object of the present invention is to develop a method of manufacturing which produces columnar shaped pieces with definitely improved strength.
These objects, as well as other objects which will become apparent in the discussion that follows, are achieved, in accordance with the present invention, in that the ancillary pieces are essentially overlapping plates or "slabs" and essentially parallel with one another and the longitudinal axis of the columnar shaped piece. This design definitely reduces the tendency of the thermoplastic material that constitutes the matrix to creep subject to long-term stress and allows the columnar piece to be employed as a structural element.
It has been demonstrated especially practical for the slabs to be essentially the same size longitudinally and transversely. This feature will help ensure that the slabs overlap like roofing tiles along and around the columnar piece. All mechanical properties, especially bending resistance, resistance to compression, and resistance to buckling will be definitely improved along and around the piece.
The slabs should if at all possible be 0.2 to 0.4 as thick as they are long and wide.
This feature will help ensure orientation of the slabs parallel to one another and to the axis of the piece while it is being manufactured by extruding a blend.
The slabs can be duroplastic, preferably reinforced with fiber. Materials of this nature are widely employed in the manufacture of automobile bodies in the form of extensive surfaces. It has up to now been impossible to recycle them and they are accordingly cheap and plentiful. They can easily be broken down into slabs of the size needed for the present application with mechanical breakers or screen mills. The process is accompanied by the advantage that the edge of the resulting slabs is irregular, so that the ends of any fibers included therein will extend beyond it. This characteristic improves bonding the slabs into the thermoplastic matrix. Another advantage is that plastic resins and thermoplastics have essentially the same coefficient of linear heat expansion, and fluctuations in the temperature at which the piece is used cannot lead to interior stress.
The piece should have embedded in it 10 to 40 slabs: in practical terms 20 to 30% of its weight in slabs. It is within the latter range in particular that the slabs can easily be embedded in the piece arrayed mutually overlapping and parallel and paralleling the axis of the piece. Their mechanical properties are accordingly able to optimally complement those of the thermoplastic matrix to the extent that severe mechanical stress can be accommodated and that attenuation will be satisfactory, which is a major advantage in terms of impact absorption. Heat expansion and shrinkage on the part of the columnar piece cannot destroy the adhesion between the embedded slabs and the plastic matrix. An especially satisfactory mechanical resistance on the part of the piece and in particular definitely improved bending and buckling resistance in relation to weight can be attained when the slabs are embedded closer together at the periphery of the piece than they are at the core. It has also been demonstrated to be advantageous for the plastic at the core of the piece to be at least partly expanded.
In the manufacturing method in accordance with the invention, the molten thermoplastic is blended with ancillary pieces in the shape of slabs; the molten thermoplastic with the slabs in it is introduced in the form of a flexible paste-like strand or "billet"that rotates around a horizontal axis into one end of the mold and, inside the mold, is brought into contact with its inner surface along the circumference; and the aforesaid introduction continues until the inner surface is continuously and uniformly covered with constituents of the billet. Various forces act on the billet while it is being introduced into the mold. The diameter of the billet is always shorter than that of the mold. Its forward end will accordingly, and due to its satisfactory plastic deformability subsequent to introduction into the mold, sag and come into contact with the latter's inner surface, resulting in a certain level of mutual adhesion. The billet will accordingly begin to rotate as well as advance. The subsequently introduced constituents of the billet will accordingly constantly and continuously be brought into contact along the circumference inside the mold, resulting in mutual adhesion, initially with the inner surface and then with the already deposited constituents of the billet until the available space between the deposited constituents and the outlet from the extruder is completely occupied. The billet, as it continues to enter in the same mode will now occasion a relative displacement and replacement of the constituents already deposited in the mold to the extent that the original adhesion between the billet and the inner surface will be destroyed and the original billet will be transformed into the piece. The rear end of the piece will accordingly be constantly augmented with new subsidiary sections while its forward end travels through the columnar mold and eventually comes into contact with the mold's forward wall. It is of advantage to position in this vicinity a sensor that will emit a signal when the new piece is finished. The piece will now be cooled to solidify it, with shrinkage decreasing the diameter to produce a gap at the inner surface of the mold. The piece will accordingly be extremely easy to remove with a compressed fluid, air for example.
The slabs in the resulting pieces are surprisingly continuously mutually overlapping, extending essentially parallel to one another and to the piece's axis. The slabs are surrounded on all sides by the plastic matrix and can accordingly not be detected at the surface of the piece. The piece's mechanical properties are in any case significantly improved.
The method in accordance with the invention is especially appropriate for processing waste plastic into new products. The waste must be broken up small and thoroughly mixed to be smoothly supplied to the extruder. In addition to the thermoplastic constituents, those based on polyolefins and polyvinyl chloride for example, the blend can contain slabs of such a non-creeping hard material as fiber-reinforced epoxide resin. The slabs can measure approximately 5 to 10 mm longitudinally and transversely and be 0.5 to 3 mm thick. Dyes of conventional composition can be included when necessary. The starting materials can be of any form--moldings and imprinted or unimprinted sheet for example.
The extruder in the generic device has in accordance with the invention only one screw, which is coaxial with the outlet and the mold. Ideally, the rotation will be superimposed over the force that expels the billet. The ratio between the open diameter D1 of the outlet and the free diameter D2 of the extruder should preferably be between 0.3 and 0.8, provided that the diameter D1 of the outlet is at least twice as long as the longest slab.
It has been demonstrated to be of advantage for the same reason for the outlet to be circular. This feature promotes the desired rotation of the billet around its axis. The ratio between the length and the diameter of the outlet should also be as small as possible and should not exceed 1.
The extruder should if possible not have any degassing device. The bubbles of air or gas expelled from such an embodiment along with the billet are surprisingly not uniformly distributed over the product's cross-section. They are confined to the vicinity of the core, which is accordingly surrounded by a completely non-porous outer zone. The width of this zone is approximately constant over the circumference, and the zone is optically distinctly different from the core. No blowholes can be observed in the vicinity of the surface. The piece's surface can, rather, be of any texture, which is a significant advantage from the aspect of esthetics. The cross-sectional design hereintofore described also means particularly satisfactory buckling and bending strengths in terms of the product's weight.
In addition to the aforesaid type of mold, at least two additional molds can be associated with one extruder, each mold traveling by the extruder's outlet and stopping in front of it as desired. This approach considerably accelerates the manufacturing process in that one mold is always in the emptying position, one in the charging position, and one in the cooling position.
The individual molds in such an embodiment can revolve in a device that rotates around an axis paralleling the axis of the extruder. This system will simplify the engineering of the drive mechanism that moves the separate molds in relation to one another.
The rotating device can be immersed at least up to its axis in water, with the extruder positioned above the surface of the water next to a receptacle for the pieces. Such a design will be compact and space-saving and will provide an especially satisfactory potential for completely automating manufacture of the products.
A columnar piece in accordance with the invention can have almost any cross-section desired. Not only circular but stellate and polygonal cross-sections can easily be created. The edges of rectangular cross-sections can be of any shape--with convex or concave curves for example. It accordingly becomes possible to produce what is called profile board, which has tongues and grooves that allow it to be joined together into large surfaces, to almost zero tolerance. The ratio of the depth to the width of such pieces can easily be between 1:4 and 1:6.
The mold employed in the method in accordance with the invention can be very simple, a thin-walled cylinder of metallic material for example. It is practical not to cool the mold with an ancillary coolant until its inner surface is uniformly wet with constituents of the billet. This approach will ensure that the product will exhibit a consistent inner and outer design over its total length. The product can then be cooled by active means, by directly immersing the mold and its contents in water for example. The product's non-porous outer zone will ensure continuous cooling and solidification of the areas that determine dimensional stability. The piece can soon be removed from the mold, which is a major advantage from the aspect of economics.
The preferred embodiments of the present invention will now be described with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic longitudinal section through a preferred embodiment of a device for carrying out the method in accordance with the invention.
FIG. 2 is a top view of the device illustrated in FIG. 1.
FIG. 3 illustrates the principle involved in introducing the billet into the mold.
FIG. 3a as an overhead view of a slab.
FIGS. 4 through 7 illustrate examples of cross-sections of different columnar shaped pieces obtainable with the method in accordance with the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The device illustrated in FIGS. 1 and 2 consists of an extruder 14 positioned above a tub 8 of water.
The extruder 14 has a housing accommodating a screw 7 that rotates on a driveshaft 13. A blend 2 enters the extruder from a hopper at the left, and the threads around screw 7 force the material constantly to the right. The housing has an inside diameter D2 that decreases to a diameter D1 at the output end in the vicinity of an outlet 9. The blend 2 of granulated thermoplastic and 20 to 25% ancillary pieces by weight in the form of slabs 2.5 mm thick and 5 to 10 mm long and wide of cotton-reinforced epoxide resin enters from the hopper at the left but can accordingly not travel through extruder 14 unaltered. It is exposed to thorough kneading, resulting in melting of the thermoplastic particles and thorough distribution, bonding, and wetting of the slabs as it travels through the device. The ratio of diameter D2 to diameter D1 is approximately 2.5. The plastic leaving outlet 9 is accordingly in the form of an essentially homogeneous and viscous billet rotating and traveling toward the right with slabs embedded in it paralleling the direction of emergence.
Downstream and to the right of extruder 14 is a mold 4 in the form of a thin-walled metal cylinder. The mold is forced against the downstream end of the extruder by a pressure-generating device 16 The mold is coaxial with outlet 9 and screw 7. It is mounted in a device 10 that secures not only mold 4 but other molds 4.1 to 4.3 as well and rotates around an axis 11 paralleling the axis of extruder 14. The individual molds accordingly revolve past the outlet 9 from the extruder and can stop in front of it as desired. The molds in rotating device 10 are all columnar shaped and are charged concentrically with the axis from the left end. As long as this latter condition is ensured, they can also have different cross-sections.
Rotating device 10 is immersed in tub 8 with its axis 11 below the surface of the water. The water can be at room-temperature.
Above the tub 8 and next to the extruder 14 is a receptacle 15 for finished pieces 1, which are in the present case expelled from occupied mold 4.3 by compressed air injected through a nozzle 17 into the mold's right end (in the direction indicated by the arrow 17.1) A stop 18 accurately positions the expelled pieces in receptacle 15. The stop can then be pivoted down around its axis (in the plane of projection) to allow the intercepted piece to enter an assembling device 19--a shipping pallet or something similar.
FIG. 3 schematically illustrates how a billet 3 is introduced into a mold 4. Billet 3 arrives through the outlet 9 from extruder 14 rotating around its axis and moving forward toward the center of the downstream end of mold 4, which is surrounded by a rigid inner surface and positioned in stationary relation to outlet 9. Billet 3 is in an easily deformable state and rests subject to gravity initially below outlet 9 against the inner surface of the mold 4, where a certain mutual adhesion between it and the mold 4 occurs due to the billet's adhesive properties. Due to the pressure of additional constituents of the billet 3 as they arrive and revolve around its axis, a deposit will continue to occur along the circumference of the mold 4, resulting in mutual adhesion with inner surface 6 and with the already deposited constituents of the billet 3. The originally available space between the deposited constituents of the billet 3 and outlet 9 will accordingly become completely occupied, and the already deposited constituents will be displaced into still available spaces, creating the initial subsidiary section of the columnar piece. The embedded slabs will surprisingly now all extend parallel to one another and to the axis of piece 1.
The original adhesion against the inner surface 6 of mold 4 will simultaneously be destroyed, and, although new constituents of piece 1 will continually come into existence at the left, the right end of the piece will become increasingly displaced to the right, in the direction indicated by the outlined arrow inside mold 4. This process will continue until mold 4 is completely charged and inner surface is continuously and uniformly covered with constituents of the billet 3. The attainment of this state will be indicated by a sensor 16 that communicates electrically with a switch that, when said state is attained, interrupts the supply of billets and rotates the device 10 around its axis. Hot and charged mold 4 enters the water in tub 8, and charged mold 4.1, which has already been cooled in the water, is positioned for discharging in front of receptacle 15, while another mold, which has already been discharged, is positioned for charging. The extruder 14 can now be engaged again, and the mold 4.3 in the discharging position can be discharged with compressed air from the nozzle 17, introducing the next cycle.
FIGS. 4 through 7 illustrate different inner and outer cross-sections of columnar shaped pieces manufactured with the method and device in accordance with the invention. Characteristic of all these pieces is that, in addition to an almost non-porous zone around the edge with an essentially constant width, they have almost a foam structure at the core. The slabs at the edge are surprisingly all comprised of the hard material and extend parallel to one another and to the axis of the piece. They have a relatively extensive surface and accordingly adhere satisfactorily to the plastic matrix around them even when the two materials are not ideally matched. The pieces are accordingly provided with a skeletal reinforcement by the slabs, which finally dictates their outstanding mechanical strength and satisfactory chemical resistance. The surface consists entirely of constituents of the plastic matrix. It can have any desired texture, which is a significant aesthetic advantage. It can easily be scored to imitate leather or wood. The cross-section can be rectangular, circular, or stellate.
There has thus been shown and described a novel columnar shaped piece and method of manufacturing the same which fulfills all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow. | 4y
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BACKGROUND OF THE INVENTION
The subject matter disclosed herein relates to a device and method of verifying electrical pulses, and in particular to a device and method for verifying electrical utility meter pulses in parallel with a load monitoring system.
Many applications use pulse generators to transmit a pulse signal that indicates a unit of measurement. In an exemplary application, an electrical utility meter uses a relay to generate a pulse each time a dial on the utility meter rotates. By accumulating the number of pulses transmitted during a given time period, a usage parameter (e.g. kilowatt-hours) may be determined. The use of a pulse generator provides advantages in extending older technologies that may lack communications capability. The pulse generator further provides advantages by allowing a third party access to information from a metering device without having to provide a connection to the processing or communication circuitry of the meter. It should be appreciated that providing access to the communication circuitry of a meter may weaken security or create the risk of unauthorized access.
In an exemplary embodiment of an electrical utility meter, the pulse generator may be relay having two dry contacts (form C) or a single dry contact (form A), sometimes referred to as a KYZ or KY, KZ pulse output relay. Each time the meter disk or disk emulator (on digital meters) rotates a full turn, the relay changes state between the dry contacts. This change in state creates what can be considered a pulse signal on the relay output. By knowing the scaling of the disk rotation, the amount of electrical power consumed may be determined by counting the number of pulses generated over a period of time. The relay output for electrical meters is often used to provide the customer with a way to monitor their electrical usage in near real-time. It is common for electrical meters to have the pulse generating relay built in and connected with an external terminal block or wiring harness that allows the customer access to the pulses.
Another application is in energy usage consulting. Devices are commercially available that connect to the front of a utility meter and optically determine the rotation of the meter disk (on mechanical meters) or disk emulator/calibration pulses (on digital meters). The device then generates a pulse each time that a disk or disk emulator/calibration pulses completes a rotation. The energy consultant may then use this information to determine the impact of various changes that are made to the connected facility rather than waiting for the monthly utility account statement.
One problem that arises in these applications is when there is a discrepancy between the meter and the system that accumulates the pulses. It is difficult to trace the source of the error to determine if the error originates in the utility meter, or in the customer system.
Accordingly, while existing pulse systems are suitable for their intended purpose, there remains a need for improvements particularly in systems and methods for verifying the accuracy of the pulse system.
BRIEF DESCRIPTION OF THE INVENTION
According to one aspect of the invention, a device is provided having a first input. A pulse splitting relay having a second input is electrically coupled to the first input. The pulse splitting relay further includes a first output and a second output electrically coupled to the second input. A recorder is electrically coupled to the first output, the recorder further has a processor responsive to executable computer instructions when executed on the processor for receiving a first signal from the first output and storing data in memory in response to the first signal. The data may include a date and time when the first signal was received.
According to another aspect of the invention, a pulse verifying system is provided. The system includes a pulse source. A demark device is operably coupled to the pulse source, the demark device being adapted to receive a pulse signal from the pulse source and inhibit electrical power from transmitted from the demark device to the pulse source. A verifying device is operably disposed between the pulse source and the demark device. The verifying device includes a pulse splitting relay having a first input operably coupled to the pulse source, a first output and a second output, wherein the second output is operably coupled to the demark device. The verifying device further includes a recorder operably coupled to the first output, the recorder has a processor that is responsive to executable computer instructions when executed on the processor for storing data in memory in response to receiving a first signal from the first output, wherein the data includes a date and a time when the first signal was received.
According to yet another aspect of the invention, a method of verifying electrical pulses is provided. The method includes generating a first series of pulses with a pulse source, wherein each of the first series of pulses corresponds to a unit of measurement. The first series of pulses is transmitted to an input of a pulse splitting relay. A second series of pulses is generated with the pulse splitting relay in response to the pulse splitting relay receiving the first series of pulses. A third series of pulses is generated with the pulse splitting relay in response to the pulse splitting relay receiving the first series of pulses. The second series of pulses is transmitted to a recorder. A first data is stored with the recorder in response to receiving the second series of pulses, the first data includes a date and time when each of the second series of pulses was received by the recorder. The third series of pulses is transmitted to a first output.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWING
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a block diagram of a pulse verifier in accordance with an embodiment of the invention;
FIG. 2 is a perspective view illustration of a pulse verifier in accordance with an embodiment of the invention;
FIG. 3 is a schematic diagram of the pulse verifier of FIG. 2 ;
FIG. 4 is a block diagram of a pulse verifier in accordance with another embodiment;
FIG. 5 is a block diagram of a pulse verifier in accordance with another embodiment; and,
FIG. 6 is a block diagram of a pulse verifier in accordance with another embodiment.
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the invention provide advantages in allowing personnel to verify the accuracy or precision of pulse signals from a pulse generation source. Embodiments of the invention provide further advantages in monitoring pulse signals in parallel with an external system. Yet further embodiments of the present invention provide further advantages in locating the sources of error in a system using pulse signals. Still further embodiments of the invention provide advantages in being portable and transportable by a single person.
Referring now to FIG. 1 , an exemplary pulse verifier device 20 is illustrated. The device 20 includes an input 22 that is received from a pulse generation source, such as a dry contact relay 24 ( FIG. 4 ) for example, that generates a series of signal pulses. The input 22 is connected to a pulse splitting relay 26 . In the exemplary embodiment, the pulse splitting relay 26 is an isolation relay model “Sentry 30” produced by Austin International. The pulse splitting relay 26 accepts the signal from input 22 provides a first bistable output 28 and a second bistable output 30 . In the exemplary embodiment, the pulse splitting relay 26 receives input electrical power 32 from an external source. The pulse splitting relay 26 isolates the output signals 28 , 30 from the input 22 and creates a pair of output pulse signals that are substantially identical to the input pulse signal received from input 22 .
The first output signal 28 is transmitted to a recorder 34 . The recorder 34 includes a controller having a processor 36 and memory 38 . In the exemplary embodiment, the recorder 34 is a utility grade data recorder, such as Model SSR-660 data recorder manufactured by Transdata, Inc. The recorder 34 is a suitable electronic device capable of accepting data and instructions, executing the instructions to process data and storing the results. The recorder 34 may accept instructions and data through a user interface, or other means such as by not limited to electronic data card, voice activation means, manually operable selection and control means, radiated wavelength and electronic or electrical transfer. In the exemplary embodiment, the recorder 34 includes an optical interface 40 that provides a connection with an external device, such as a laptop computer for example.
The recorder 34 is capable of converting the pulse signal from pulse splitting relay 26 into a digital record. In general, the recorder 34 accepts the data from the pulse splitting relay 26 and is given certain instructions for the purpose of associating the pulse signal data with one or more data, such as but not limited to time data and date data for example. The recorder 34 stores data in memory 38 so that it may be later received by an external device (not shown). In one embodiment, the recorder 34 includes, or is connected to a communications device, such as a cellular (CDMA, GSM) modem, a telephone modem, or a local area network for example. The memory 38 may include one or more types of memory, including random access memory (RAM), non-voltile memory (NVM) or read-only memory (ROM). The recorder 34 may further include one or more input/output (I/O) controllers or (not shown).
The recorder 34 includes operation control methods embodied in application code. These methods are embodied in computer instructions written to be executed by processor 36 , typically in the form of software. The software can be encoded in any language, including, but not limited to, assembly language, VHDL (Verilog Hardware Description Language), VHSIC HDL (Very High Speed IC Hardware Description Language), Fortran (formula translation), C, C++, Visual C++, Java, ALGOL (algorithmic language), BASIC (beginners all-purpose symbolic instruction code), visual BASIC, ActiveX, HTML (HyperText Markup Language), and any combination or derivative of at least one of the foregoing. Additionally, an operator can use an existing software application such as a spreadsheet or database and correlate various cells with the variables enumerated in the algorithms. In one embodiment, the recorder 34 includes an imbedded web server that allows service personnel to communicate with the recorder 34 from remote locations. Furthermore, the software can be independent of other software or dependent upon other software, such as in the form of integrated software.
In the exemplary embodiment, the device 20 receives a pulse signal from input 22 . The pulse splitting relay 26 receives the pulse signal and generates a first output signal 28 and a second output signal 30 . The second output signal 30 is transmitted to an external device or system, such as but not limited to another recorder, a building management system, an accumulator and the like. The first output signal is transmitted to the recorder 34 . The pulse signal data is combined with a date and time data for when the pulse signal was received. The pulse signal data, and or the date and time data are stored in memory 38 . Periodically, service personnel visit the device 20 and connect an external data collection device (not shown), such as a laptop computer for example, to the device 20 . In the exemplary embodiment the external data collection device transmits a signal via the optical interface 40 to the recorder 34 . When the signal is received via the optical interface 40 , the processor 36 retrieves the pulse signal data and date and time data from memory 38 and transmits the data to the external data collection device via optical interface 40 . In one embodiment, the data includes an accumulated pulse signal data. In another embodiment, the processor 36 converts the pulse data into a unit of measurement, such as kilowatt-hours for example.
Another embodiment of a portable pulse verifier device 20 is illustrated in FIG. 2 and FIG. 3 . In this embodiment, the device 20 includes a housing 42 . The housing 42 includes a plurality of walls 44 that define rectangular parallelepiped box having a substantially hollow interior portion 46 . One side of the housing is a movable lid or cover 48 that is coupled to the walls 44 by one or more hinges 50 . In the exemplary embodiment, the cover 48 may include a lock to prevent unauthorized access to the recorder 34 . In one embodiment, the housing 42 is the substantially the size of a briefcase and of a weight such that the device 20 may be carried by a single person. In one embodiment, the housing 42 includes a handle 45 on one wall. It should be appreciated that having a portable pulse verifier device 20 provides advantages in allowing service personnel to quickly deploy the device 20 to a desired location and allows the device 20 to remain at the installation site to collect data until the service personnel return.
Arranged within the interior portion 46 is the recorder 34 and pulse splitting relay 26 . The recorder 34 and pulse splitting relay 26 are electrically coupled as illustrated in FIG. 3 to a terminal block 52 having post terminals for connection to the pulse source generator. Adjacent the input terminal block 52 is an electrical power inlet 54 . In the exemplary embodiment, the electrical power inlet 54 is coupled to provide 120 Volt electrical power to the “K” line input terminal 56 on the pulse splitting relay 26 and on the “K” output post 60 of output terminal block 58 . Since external power is provided to the pulse splitting relay 26 , the received pulse signals may be replicated and transmitted without loss of signal quality or strength.
An exemplary embodiment of an application using the device 20 with a utility meter 60 is illustrated in FIG. 4 . Utility meters 60 are commonly used to measure and report the consumption of electrical power delivered to a customer. These meters 60 commonly provide a pulse signal output that allows an end customer or other third party to receive a signal that may be used for monitoring electrical consumption without waiting for a monthly statement from the utility or power provider. This pulse signal output is typically generated by a dry contact relay 24 that is connected with a terminal block or other wired connection that allows the customer to connect with the meter 60 . The pulse signal may be used by the customer in a number of ways, such as during energy audits to determine to effect of different changes being made to the facility, or it may be used in conjunction with a building management system to allow monitoring of energy usage, or it may be used with a demand response program to monitor compliance during peak demand periods for example.
A connection 62 , such as a three-wire connection for example, transmits the pulse signal from the dry contact relay 24 to the device 20 . The device 20 receives the pulse signal as discussed herein above and generates a first output pulse signal that is transmitted to the recorder 34 and a second output pulse signal that is transmitted over connection 64 to a demark box 66 . A demark box 66 is a standard device used in connection with utility meters that allows the pulse signal to pass into the customers system, such as to a building management system 68 for example. The demark box 66 provides a level of protection by allowing the pulse signal to pass into the system 68 but prevents or inhibits excess electrical current or voltage from being transmitted into the utility owned equipment. In essence, the demark box 66 keeps the customers system from impacting the operation (or damaging) the utility meter 60 .
When arranged in the configuration illustrated in FIG. 4 , the device 20 records the pulse signal in parallel with the transmission of the pulse signal to the demark box 66 . If the data recorded by the system 68 is different from the device 20 , then any errors in the pulse signal recorded by the customer would be originating on the customer's side of the demark box 66 . Conversely, if the data recorded by the device 20 and that system 68 match, then the service personnel may have to examine the utility meter 60 as a possible source of error. It should be appreciated that it is undesirable to remove the utility meter 60 or replace it unnecessarily since once the utility meter 60 is removed, the utility meter 60 will typically need to be recertified before being redeployed to another installation. The recertification process for the utility meter is costly and time consuming unless justified with some indication that the utility meter 60 is faulty.
Another embodiment of an application utilizing the device 20 with a utility meter 60 is illustrated in FIG. 5 . In this embodiment, the pulse signal is transmitted over connection 62 to the demark box 66 . The pulse signal passes through the demark box 66 over a connection 70 to the device 20 . The device 20 receives the pulse signal and generates a first output pulse signal that is transmitted to the recorder 34 and a second output pulse signal that is transmitted to a downstream receiving system, such as building management system 68 for example. When arranged in this configuration, the data recorded by the recorder 34 and by the downstream system may be compared. If the data matches, then the component that is inducing an error may be the demark box 66 for example. If the data does not match, then the error may be introduced somewhere in the downstream system.
Yet another embodiment of an application utilizing the device 20 with multiple utility meters 60 , 72 is illustrated in FIG. 6 . In this embodiment, the application utilizes two utility meters to measure electrical consumption. This type of arrangement may be used in a building having multiple leaseholders for example where each meter is connected to an electrical service associated with each leased space. The embodiment further uses an external recorder 74 that aggregates the measurements from the utility meters 60 , 72 and transmits the data to the utility, such as via a telephone connection 76 for example. The external recorder 74 then transmits the signal to the demark box 66 and to the system 68 . In this embodiment, the device 20 is arranged between the utility meter 60 and the external recorder 74 . The pulse signal from utility meter 60 is transmitted to the device 20 that transmits a first output pulse signal to recorder 34 and a second output pulse signal to the external recorder 74 . In this configuration, any issue in the connection between the utility meter 60 and the external recorder 74 may be isolated and identified even though a second utility meter 72 is arranged in parallel.
An embodiment of the invention may be embodied in the form of computer-implemented processes and apparatuses for practicing those processes. The present invention may also be embodied in the form of a computer program product having computer program code containing instructions embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, USB (universal serial bus) drives, or any other computer readable storage medium, such as random access memory (RAM), read only memory (ROM), or erasable programmable read only memory (EPROM), for example, wherein, when the computer program code is loaded into and executed by a computer, the computer becomes an apparatus for practicing the invention. The present invention may also be embodied in the form of computer program code, for example, whether stored in a storage medium, loaded into and/or executed by a computer, or transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein when the computer program code is loaded into and executed by a computer, the computer becomes an apparatus for practicing the invention. When implemented on a general-purpose microprocessor, the computer program code segments configure the microprocessor to create specific logic circuits. A technical effect of the executable instructions is to record pulse signals in parallel with a system for verifying the accuracy or precision of a pulse source.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims. | 4y
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a divisional of U.S. patent application Ser. No. 12/474,408, entitled “Coulter Assembly”, filed May 29, 2009, now U.S. Pat. No. 8,047,147, which is herein incorporated by reference in its entirety.
BACKGROUND
The invention relates generally to a coulter assembly, and more specifically, to a continuously variable depth adjustment system for altering a coulter disk penetration depth.
Generally, coulters are towed behind a tractor via a mounting bracket secured to a rigid frame of the implement. Coulters are typically configured to excavate a trench into soil, and may assist in delivering a liquid or dry fertilizer into the trench. Specifically, certain coulters include a coulter disk that cuts into the soil as the coulter moves along the terrain. A penetration depth of the coulter disk is generally regulated by a gauge wheel. In a typical configuration, the gauge wheel is positioned adjacent to the coulter disk and rotates across the soil surface. The coulter disk is positioned below the gauge wheel such that the coulter disk penetrates the soil. A vertical offset distance between the coulter disk and the gauge wheel determines the coulter disk penetration depth. As will be appreciated by those skilled in the art, the effectiveness of fertilizer may be dependent upon its deposition depth within the soil. Therefore, precise control of coulter disk penetration depth may be beneficial for crop growth.
However, typical coulter assemblies only facilitate gauge wheel adjustment in discrete increments. For example, the gauge wheel may only be adjusted between two or three discrete positions. As a result, the coulter may not deposit the fertilizer at a suitable depth to enhance crop growth.
BRIEF DESCRIPTION
The present invention provides a coulter assembly configured to facilitate continuous adjustment of coulter disk penetration depth. In an exemplary embodiment, the coulter assembly includes a support structure and a coulter disk rotatable coupled to the support structure. A gauge wheel is movably coupled to the support structure and configured to rotate across a surface of the soil to limit a penetration depth of the coulter disk into the soil. A depth adjustment assembly is coupled to the gauge wheel and configured to adjust the penetration depth of the coulter disk by continuously varying the vertical position of the gauge wheel. This configuration enables any coulter disk penetration depth to be selected within the gauge wheel range of motion, thereby facilitating deposition of fertilizer within the soil at a suitable depth to enhance crop growth.
DRAWINGS
These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:
FIG. 1 is a perspective view of a towable agricultural implement including multiple coulter assemblies;
FIG. 2 is a detailed perspective view of one coulter assembly, as shown in FIG. 1 ;
FIG. 3 is a left side view of the coulter assembly of FIG. 2 , showing a support structure, a coulter disk, a gauge wheel, and a swing arm;
FIG. 4 is an exploded view of the coulter assembly of FIG. 2 , showing the support structure, the coulter disk, the gauge wheel, and the swing arm;
FIG. 5 is a right side view of the coulter assembly of FIG. 2 , showing the support structure and a depth adjustment assembly; and
FIG. 6 is an exploded view of the coulter assembly of FIG. 2 , showing the support structure and the depth adjustment assembly.
DETAILED DESCRIPTION
Turning now to the drawings, FIG. 1 is a perspective view of a towable agricultural implement 10 including multiple left-handed coulter assemblies 12 and right-handed coulter assemblies 14 . As discussed in detail below, the coulter assemblies 12 and 14 may include a coulter disk configured to excavate a trench into soil. A fertilizer delivery assembly positioned behind the coulter disk may then inject a liquid or dry fertilizer into the trench. In such an arrangement, seeds planted adjacent to the trench may receive a proper amount of fertilizer. As illustrated, the coulter assemblies 12 and 14 are secured to shanks 16 that couple the coulter assemblies 12 and 14 to a tool bar 18 . In the present embodiment, the tool bar 18 includes 12 left-handed coulter assemblies 12 and 12 right-handed coulter assemblies 14 . Further embodiments may include more or fewer coulter assemblies 12 and 14 . For example, certain embodiments may include 2, 4, 6, 8, 10, 14, 16, or more left-handed coulter assemblies 12 and right-handed coulter assemblies 14 . The tool bar 18 is coupled to a tow bar 20 , including a hitch 22 . The hitch 22 may, in turn, be coupled to a tractor such that the towable agricultural implement 10 may be pulled through a field. In certain embodiments, the tool bar 18 , including the coulter assemblies 12 and 14 , precedes row units configured to deposits seeds into the soil. In such embodiments, the row units may be offset from the coulter assemblies 12 and 14 such that the seeds are deposited a desired distance from the fertilizer enriched trench. This configuration may enable the crops to absorb a proper amount of fertilizer as they grow.
As discussed in detail below, a penetration depth of each coulter disk may be varied by adjusting a vertical position of a gauge wheel. Specifically, the gauge wheel may rotate across a surface of the soil to limit coulter disk penetration. Increasing or decreasing the vertical position of the gauge wheel with respect to the coulter disk varies the penetration depth. In the present embodiment, a depth adjustment assembly is coupled to the gauge wheel to continuously vary its vertical position. Therefore, any coulter disk penetration depth within the gauge wheel range of motion may be selected.
FIG. 2 is a detailed perspective view of a left-handed coulter assembly 12 . The coulter assembly 12 is coupled to the shank 16 by a tool bar mount 24 . As illustrated, the tool bar mount 24 is rotatably coupled to a support structure 26 by a shaft 28 . The shaft 28 enables the support structure 26 to rotate about an axis 30 in a direction 32 in response to obstructions or variations in the terrain. Specifically, the tool bar mount 24 may be coupled to the shank 16 by fasteners that pass through openings 34 in the tool bar mount 24 . The tool bar mount 24 includes a spring plate 36 configured to limit rotation of the support structure 26 with respect to the tool bar mount 24 . The coulter assembly 12 includes a threaded rod 38 and a compression spring 40 configured to maintain a substantially constant force between the gauge wheel and the soil. Specifically, the threaded rod 38 passes through an opening in the spring plate 36 , and the spring 40 is disposed about the threaded rod 38 . A first spring stop 42 is disposed between the spring 40 and the spring plate 36 , and a second spring stop 44 is disposed adjacent to the opposite end of the spring 40 to ensure that the spring 40 remains disposed about the threaded rod 38 . The second spring stop 44 is secured to the spring 40 by a washer 46 and a pair of fasteners 48 . The threaded rod 38 is coupled to a pin 50 that passes through a hole 52 in the support structure 26 . The pin 50 is secured to the threaded rod 38 by a loop 54 and the support structure 26 by a cotter pin 56 .
The structure described above enables the support structure 26 to rotate about the axis 30 in the direction 32 in response to variations in field conditions. For example, if the support structure 26 is driven to rotate in the direction 32 by contact with an obstruction, the support structure 26 may rotate about the shaft 28 . As the support structure 26 rotates, the spring 40 is compressed, thereby biasing the support structure 26 toward its initial orientation. Specifically, rotation of the support structure 26 causes the pin 50 to rotate about the axis 30 in the direction 32 . Because the pin 50 is coupled to the threaded rod 38 by the loop 54 , the threaded rod 38 is driven to translate through the opening in the spring plate 36 . The spring 40 is then compressed between the spring stops 42 and 44 by the washer 46 secured to the threaded rod 38 by the fasteners 48 . The spring compression applies a biasing force to the support structure 26 by the previously described linkage, thereby inducing the support structure 26 to return to its initial orientation. Such a configuration may serve to protect the coulter assembly 12 by absorbing the impact of obstructions encountered during cultivation.
The coulter assembly 12 also includes a coulter disk 58 rotatably coupled to the support structure 26 by a bearing assembly 60 . The bearing assembly 60 enables the coulter disk 58 to freely rotate as it engages the soil and excavates a trench. The coulter assembly 12 also includes a scraper 62 disposed adjacent to the coulter disk 58 and coupled to the support structure 26 by a bracket 64 . The scraper 62 is configured to remove accumulated soil from the coulter disk 58 and may serve to widen the trench. The scraper 62 is coupled to a fertilizer tube 66 configured to deliver liquid or dry fertilizer into the trench.
A gauge wheel 68 is pivotally coupled to the support structure 26 by a swing arm 70 . The swing arm 70 is, in turn, coupled to a depth adjustment assembly 72 configured to continuously vary the vertical position of the gauge wheel 68 with respect to the support structure 26 . As discussed in detail below, because the gauge wheel 68 travels along the surface of the soil, varying the position of the gauge wheel 68 alters the penetration depth of the coulter disk 58 into the soil. The depth adjustment assembly 72 includes a lever 74 and a shaft 76 . The shaft 76 is rigidly coupled to a first end of the lever 74 , and a linear actuator is coupled to the second end. In this configuration, extension and retraction of the linear actuator induces the lever 74 and the shaft 76 to rotate. In certain embodiments, the linear actuator may include a pneumatic cylinder, a hydraulic cylinder, or an electromechanical actuator, for example. In the present embodiment, the linear actuator includes a rod 78 , a pin 80 , a mount 82 , a first fastener 84 and a second fastener 86 . As discussed in detail below, adjusting the position of the fasteners 84 and 86 with respect to the rod 78 rotates the lever 74 , thereby rotating the shaft 76 coupled to the swing arm 70 . Rotating the swing arm 70 alters the vertical position of the gauge wheel 68 , thereby varying the penetration depth of the coulter disk 58 . Because the fasteners 84 and 86 may be positioned at any location along the length of the rod 78 , extension and/or retraction of the rod 78 with respect to the mount 82 may be continuously varied. Therefore, any coulter disk penetration depth within a range defined by the length of the rod 78 and the geometry of the depth adjustment assembly 72 may be achieved.
FIG. 3 is a left side view of the coulter assembly 12 , showing the support structure 26 , the coulter disk 58 , the gauge wheel 68 , and the swing arm 70 . As previously discussed, the depth adjustment assembly 72 may rotate the swing arm 70 , thereby adjusting the vertical position of the gauge wheel 68 . Specifically, the swing arm 70 includes a first region 88 and a second region 90 . The first region is rigidly coupled to the shaft 76 by a bolt 92 . In this manner, rotation of the shaft 76 induces the swing arm 70 to rotate. In addition, the gauge wheel 68 is rotatably coupled to the second region 90 by a bolt 94 . The bolt 94 enables the gauge wheel 68 to rotate as it moves across the soil surface.
In the illustrated embodiment, the gauge wheel 68 includes an outer surface 96 and an inner hub 98 . The outer surface 96 may be composed of rubber to provide traction between the gauge wheel 68 and the soil. The inner hub 98 may be composed of a rigid material (e.g., nylon) capable of supporting the outer surface 96 . As illustrated, a penetration depth D is established between the bottom of the gauge wheel 68 and the bottom of the coulter disk 58 . Specifically, because the gauge wheel 68 rotates along the surface of the soil, the coulter disk 58 may penetrate the soil to the penetration depth D. In addition, because the depth adjustment assembly 72 is configured to lock the swing arm 70 into place during operation of the coulter assembly 12 , the gauge wheel 68 may limit the penetration depth D based on the angle of the swing arm 70 . Moreover, because the depth adjustment assembly 72 is configured to continuously vary the angle of the swing arm 70 with respect to the support structure 26 , the depth adjustment assembly 72 may continuously vary the penetration depth D of the coulter disk 58 into the soil.
In the present embodiment, the gauge wheel 68 is disposed directly adjacent to the coulter disk 58 . In this configuration, the gauge wheel 68 may serve to remove accumulated soil from the coulter disk 58 as the gauge wheel 68 rotates. In certain embodiments, the gauge wheel 68 is angled about a longitudinal axis of the support structure 26 toward a soil penetrating portion of the coulter disk 58 . This arrangement may serve to enhance soil removal from the coulter disk 58 .
FIG. 4 is an exploded view of the coulter assembly 12 , showing the support structure 26 , the coulter disk 58 , the gauge wheel 68 , and the swing arm 70 . Specifically, FIG. 4 illustrates the internal parts that enable the swing arm 70 to rotate with respect to the support structure 26 . As previously discussed, the swing arm 70 is rigidly coupled to the shaft 76 . To limit rotation of the swing arm 70 with respect to the shaft 76 , a key 100 is inserted into a recess 102 in the shaft 76 . A bearing 104 is then disposed between the shaft 76 and the support structure 26 to enable the shaft 76 to rotate within the support structure 26 . The first region 88 of the swing arm 70 includes an opening 106 including a recess 108 configured to interlock with the key 100 . Specifically, the recess 108 is aligned with the key 100 prior to disposing the opening 106 about the shaft 76 . Interaction between the key 100 and the recess 108 limits rotation of the swing arm 70 with respect to the shaft 76 . Therefore, rotation of the shaft 76 by the depth adjustment assembly 72 rotates the swing arm 70 , while limiting rotation of the swing arm 70 during operation of the coulter assembly 12 . Finally, the swing arm 70 is secured to the shaft 76 by the bolt 92 and washers 110 and 112 .
As previously discussed, the gauge wheel 68 is coupled to the second region 90 of the swing arm 70 by the bolt 94 . Specifically, the bolt 94 passes through the gauge wheel 68 and a washer 114 . The bolt 94 then secures to an opening 116 within the second region 90 of the swing arm 70 . This configuration enables the gauge wheel 68 to rotate with respect to the swing arm 70 as it moves across the soil surface.
FIG. 5 is a right side view of the coulter assembly 12 , showing the support structure 26 and the depth adjustment assembly 72 . As previously discussed, the depth adjustment assembly 72 facilitates continuous adjustment of the penetration depth D of the coulter disk 58 into the soil by adjusting the vertical position of the gauge wheel 68 . Specifically, a position of the rod 78 may be varied by adjusting the position of the fasteners 84 and 86 with respect to the mount 82 . In certain embodiments, the rod 78 may be threaded and the fasteners 84 and 86 may be nuts including complementary threads configured to mate with the threaded rod 78 . In such a configuration, washers 118 and 120 may be disposed between the nuts 84 and 86 , respectively, and the mount 82 . For example, the rod 78 may be translated in a direction 122 by uncoupling the fastener 86 , moving the rod 78 in the direction 122 , and then securing both fasteners 84 and 86 about the mount 82 . Translating the rod 78 in the direction 122 rotates the lever 74 in a direction 124 , thereby rotating the shaft 76 in the direction 124 . As previously discussed, the shaft 76 is rigidly coupled to the swing arm 70 . Therefore, rotating the shaft 76 in the direction 124 induces the swing arm 70 to rotate in the direction 124 , thereby increasing the vertical displacement of the gauge wheel 68 with respect to the support structure 26 and increasing the penetration depth D of the coulter disk 58 .
Conversely, the rod 78 may be translated in a direction 126 by uncoupling the fastener 84 , moving the rod 78 in the direction 126 , and then securing both fasteners 84 and 86 about the mount 82 . Translating the rod 78 in the direction 126 rotates the lever 74 in a direction 128 , thereby rotating the shaft 76 in the direction 128 . Because the shaft 76 is rigidly coupled to the swing arm 70 , rotating the shaft 76 in the direction 128 induces the swing arm 70 to rotate in the direction 128 . Therefore, the vertical displacement of the gauge wheel 68 with respect to the support structure 26 is decreased, and the penetration depth D of the coulter disk 58 is decreased. In certain embodiments, the penetration depth D of the coulter disk 58 may be continuously varied between approximately 0 to 6 inches. However, further embodiments may have a greater or lesser range of adjustment. Because the fasteners 84 and 86 may be positioned at any location along the rod 78 , any penetration depth D may be established within the range limited by the length of the rod 78 and the geometry of the depth adjustment assembly 72 .
FIG. 6 is an exploded view of the coulter assembly 12 , showing the support structure 26 and the depth adjustment assembly 72 . As illustrated, the threaded rod 78 includes a loop 130 configured to receive the pin 80 . The loop 130 of the threaded rod 78 may be aligned with openings 132 in the lever 74 . The pin 80 may then be inserted through the openings 132 and the loop 130 to secure the threaded rod 78 to the lever 74 . The pin 80 includes a recess 134 , and the threaded rod 78 includes an opening 136 . The recess 134 may be aligned with the opening 136 , and a pin 138 may be inserted through the opening 136 and into the recess 134 . In this manner, the threaded rod 78 may be rotatably secured to the lever 74 .
As previously discussed, the lever 74 is rigidly coupled to the shaft 76 including the key 100 . A bearing 140 is disposed about the shaft 76 such that the shaft 76 may rotate within an opening 142 within the support structure 26 . This configuration may enable linear movement of the threaded rod 78 to induce rotation of the shaft 76 within the opening 142 such that the swing arm 70 rotates with respect to the support structure 26 . The threaded rod 78 may be inserted through an opening 144 in the mount 82 . As illustrated, the opening 144 is elongated in the vertical direction to enable vertical movement of the threaded rod 78 as the rod 78 translates in the direction 122 and/or 126 through the opening 144 in the mount 82 . As previously discussed, fastener 84 and washer 118 is disposed on one side of the mount 82 , while fastener 86 and washer 120 are disposed on the opposite side. In this configuration, the threaded rod 78 may be positioned and secured relative to the mount 82 such that the vertical position of the gauge wheel 68 may be continuously varied with respect to the support structure 26 , thereby enabling the penetration depth D of the coulter disk 58 to be continuously adjusted.
While only certain features of the invention have been illustrated and described herein, many modifications and changes will occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a solar cell power system, and in particular, to a solar cell power system for satellites or the like which is of the type adapted to supply power from a solar cell to a load during the sunlight while stabilizing the voltage by means of a shunt device, and also to supply power to the load through discharge from a storage battery in the eclipse time, the system having a solar array bus lockup cancelling mechanism which serves to cancel a stage in which the voltage of the solar cell power system is fixed to that of the storage battery during the sunlight and a battery continues to discharge for a long time even when the power supply to the load can be met solely with the power generated by the solar cell (The state will be hereinafter referred to as "solar array bus lockup") so that the system is restored to a state in which the voltage is regulated by the shunt device.
2. Description of the Prior Art
FIG. 1 is a block diagram showing the construction of a conventional solar cell power system, which includes a solar cell 1, a storage battery 2, a first diode 3 whose anode is connected to the output terminal of the solar cell 1, and a power bus 4 which is connected to the cathode of the first diode 3.
The system further includes a second diode 5 whose cathode is connected to the cathode of the first diode 3 through the power bus 4; a shunt device 6, which is connected between the anode of the first diode 3 and a return line (hereinafter referred to simply as RTN) in parallel with the solar cell 1, and which is adapted to consume any surplus power generated by the solar cell 1; a battery charger 7, which is connected to the power bus 4 in parallel with the second diode 5 and which serves to charge the storage battery 2 during the sunlight; a capacitor bank 8 which is connected between the power bus 4 and the RTN; and a load 9 which is connected to the power bus 4 and the RTN, and whose magnitude is set at the ground station with a command CE. In addition, the system includes a solar array current monitor 10, which is adapted to detect the level of the current flowing through the first diode 3 into the power bus 4 and convert it to a telemetry signal I SATLM before its transmittal; a load current monitor 11, which is adapted to detect the level of the current flowing through the power bus 4 into the load 9 and convert it to a telemetry signal I LTLM before its transmittal; a charge/discharge current monitor 12, which is connected between the anode of the second diode 5 and the storage battery 2, and which is adapted to detect the level of the charge/discharge current of the storage battery 2 and convert it to a telemetry signal I CTLM before its transmittal; and a bus voltage monitor 13 which is adapted to detect the voltage of the capacitor bank 8 and convert it to a telemetry signal V BUSTLM before its transmittal.
The operation of this conventional power system will now be described in detail.
During the sunlight, the power generated by the solar cell 1 is supplied to the load 9 through the first diode 3. Any surplus power that results when the power generated by the solar cell 1 exceeds the power consumed by the load 9 is partly converted by the battery charger 7 to charge the storage battery 2, and the rest is consumed by the shunt device 6.
In this process, the voltage of the capacitor bank 8 (hereinafter referred to as bus voltage) is regulated to a value V SHNT . The value of the bus voltage V SHNT is generally set to be constantly higher than that of the voltage V BAT of the storage battery 2.
FIG. 2 shows the relationship between the power generated by the solar cell 1 and the load power consumed by the load 9. The power generated by the solar cell 1 is represented by the I S -V S curve of FIG. 2. The load 9 appears to be a constant-power load since it generally contains a built-in DC/DC converter and consumes power while converting the bus voltage to an appropriate constant voltage. Accordingly, the relationship between the load voltage and the load current can be represented by the curve P--P' shown in FIG. 2.
As stated above, the shunt device 6 consumes any surplus power generated by the solar cell 1 so that the bus voltage may be regulated to V SHNT . As a result, the intersection point A of the straight line M--M' and the constant power line P--P' of FIG. 2 represents the power operating point.
In the eclipse time, power generation by the solar cell 1 is stopped, so that power is supplied to the load 9 through discharge of the storage battery 2 through the intermediation of the second diode 5. The bus voltage at this time is equal to the discharge voltage V BAT of the storage battery 2.
In order to monitor the operating condition of the power system, the solar array current monitor 10, the load current monitor 11, the charge/discharge current monitor 12, and the bus voltage monitor 13 detect the current or voltage level at different parts of the system, as stated above, and convert them to telemetry signals, which are transmitted to the ground station.
FIG. 3 shows the transition of the power operating point when load fluctuation occurs during a period of sunlight. In FIG. 3, the curve I S -V S represents the current/voltage characteristic of the power generated by the solar cell 1; V BAT represents the bus voltage value when the storage battery 2 is discharging; and V SHNT represents the value of the regulated bus voltage obtained by the solar-cell surplus-power control effected by the shunt device 6.
The case considered will be that where the power consumption by the load 9 fluctuates when the power consumed by the load 9 is P1 and the operating point is A. As long as the power consumption fluctuates within the range: V SHNT ×I S , the power operating point lies in the straight line M--M' of FIG. 3.
If, however, the power consumption of the load 9 has exceeded the range of V SHNT ×I S , increasing from P1 to P2, it exceeds the power generated by the solar cell 1, so that power compensation is effected by discharge from the storage batter 2. In this case, the power operating point moves from A to M, then to B.
Once it has moved to B, the operating point is not restored to A even if the power consumption of the load 9 is immediately reduced to P1 afterwards; it only moves to the point C. This brings about a state in which the bus voltage is fixed to the voltage of the storage battery 2, and the storage battery 2 continues to discharge, although the solar cell 1 is capable of generating all the power required by the load 9. This phenomenon is called solar array bus lockup.
To cancel solar array bus lockup, the power consumption of the load 9 is temporarily reduced to P3 or less by a command from the ground station, thus shifting the operating point in the order: C, D, E to A.
If solar array bus lockup is left unattended, the storage battery 2 will be allowed to discharge constantly, destroying the balance of power of the storage battery 2 between periods of sunlight and eclipse.
Conventionally, occurrence of solar array bus lockup has been detected in the following manner: first, discharge from the storage battery 2 is confirmed through the telemetry signal I CTLM of the charge/discharge current monitor 12. Then, a computer provided in the ground station performs a calculation using the following values: an engineering transformation I SA of the telemetry signal I SATLM of the solar array current monitor 10, an engineering transformation I L of the telemetry signal I LTLM of the load current monitor 11, and an engineering transformation V BUS of the telemetry signal V BUSTLM of the bus voltage monitor 13 as well as the regulated bus voltage value V SHNT obtained by the shunt device 6 for the purpose of checking whether the following inequality holds true or not:
V.sub.SHNT ×I.sub.SA >V.sub.BUS ×I.sub.L ( 1)
With the conventional method, solar array bus lockup is judged to have been brought about if the inequality (1) holds true.
This method, however, can only be used when communication is always possible between the satellite and the ground station, as in the case of a geostationary satellite. A satellite in a relatively low earth orbit, is in a state for a considerable length of time when no communication with the ground station is possible, if solar array bus lockup occurs during such a period, the above method cannot be used until communication with the ground station again becomes possible. Accordingly, under these circumstances prompt cancellation of solar array bus lockup cannot be effected.
It is an object of this invention to provide a solar cell power system having a solar array bus lockup cancelling mechanism which is adapted to automatically detect the occurrence of solar array bus lockup and cancel it.
SUMMARY OF THE INVENTION
In accordance with this invention, the above object is achieved by means of a solar cell power system with a solar array bus lockup cancelling mechanism, comprising: a common return line; a solar cell means having an output terminal and a terminal connected to the return line; a shunt device connected in parallel between the output terminal of the solar cell means and the return line; a power bus; a first unilateral current transmission means which has an input terminal connected to the output terminal of the solar cell means and an output terminal connected to the power bus and which allows a current to flow only from the output terminal of the solar cell means toward the power bus; a storage battery means having an output terminal and a terminal connected to the return line; a charging means connected to the power bus and the output terminal of the storage battery means in series with the storage battery means; a second unilateral current transmission means which has an input terminal connected to the output terminal of the storage battery means and an output terminal connected to the power bus and which allows a current to flow only from the output terminal of the power storage means toward the power bus; a charge storage means connected between the power bus and the return line; a load which has a first terminal connected to the power bus, a second terminal connected to the return line, and a control terminal, the load reducing its own magnitude when a load power reducing signal is supplied to the control terminal; a charge/discharge current monitor means which has an output terminal and which is connected to the storage battery means to monitor the charge/discharge current that charges the storage battery means or that is discharged therefrom, emitting through the output terminal a signal representing the charge/discharge current thus monitored; a bus voltage monitor means which has an output terminal and which is inserted between the power bus and the return line to monitor the bus voltae in the power bus, emitting through the output terminal a signal representing the bus voltage thus monitored; a solar array current monitor means which has an output terminal and which is connected to the first unilateral current transmission means to monitor the solar array current flowing from the first unilateral current transmission means to the power bus, emitting through the output terminal a signal representing the solar array current thus monitored, or a load current monitor means which has an output terminal and which is connected to the load to monitor the load current, emitting through the output terminal a signal representing the load current thus monitored; and a solar array bus lockup determining means which has three input terminals and an output terminal, two of the three input terminals being respectively connected to the output terminal of the charge/discharge current monitor means and the output terminal of the bus voltage monitor means, the remaining one input terminal being connected to either the solar array current monitor means or the load current monitor means, the output terminal being connected to the control terminal of the load, the solar array bus lockup determining means including a reference voltage generating means for generating a reference voltage representing the regulated bus voltage when the solar cell power system is not in the solar array bus lockup state with the bus voltage being regulated by the shunt device, the solar allay bus lockup determining further calculating the effective generated power of the solar cell means and the load power consumed by the load on the basis of the regulated bus voltage, the monitored bus voltage, the monitored discharge current, and either of the monitored solar array current or the monitored load current to generate a load power reducing signal at the output terminal when the effective generated power is greater than the load power.
With the above construction, this solar cell power system detects a state in which, during a period of sunlight, its bus voltage is fixed to the output voltage of the storage battery means and in which discharge from the storage battery means continues even when the solar cell means can manage to supply all the necessary load current, and temporarily reduces the magnitude of the load to restore the state in which the bus voltage is regulated by the shunt device.
In accordance with this invention, the above object is also attained by another type of solar cell power system with a solar array bus lockup cancelling mechanism, comprising: a common return line; a solar cell means having an output terminal and a terminal connected to the return line; a shunt device connected in parallel between the output terminal of the solar cell means and the return line; a power bus; a first unilateral current transmission means which has an input terminal connected to the output terminal of the solar cell means and an output terminal connected to the power bus and which allows a current to flow only from the output terminal of the solar cell means toward the power bus; a storage battery means which has an output terminal and a terminal which is connected to the return line; a charging means which is connected to the power bus and the output terminal of the storage battery means in series with the storage battery means; a second unilateral current transmission means which has an input terminal connected to the output terminal of the storage battery means and an output terminal connected to the power bus and which allows a current to flow only from the output terminal of the power storage means toward the power bus; a charge storage means connected between the power bus and the return line; a load which has a first terminal connected to the power bus, a second terminal connected to the return line; a charge/discharge current monitor means which has an output terminal and which is connected to the storage battery means to monitor the charge/discharge current that charges the storage battery means or that is discharged therefrom, emitting through the output terminal a signal representing the charge/discharge current thus monitored; a bus voltage monitor means which has an output terminal and which is inserted between the power bus and the return line to monitor the bus voltage in the power bus, emitting through output terminal a signal representing the bus voltage thus monitored; a solar array current monitor means which has an output terminal and which is connected to the first unilateral current transmission means to monitor the solar array current flowing from the first unilateral current transmission means to the power bus, emitting through the output terminal a signal representing the solar array current thus monitored, or a load current monitor means which has an output terminal and which is connected to the load to monitor the load current, emitting through the output terminal a signal representing the load current thus monitored; a solar array bus lockup determining means which has three input terminals and an output terminal, two of the three input terminals being respectively connected to the output terminal of the charge/discharge current monitor means and the output terminal of the bus voltage monitor means, the remaining one input terminal being connected to either the output terminal the solar array current monitor means or the output terminal of the load current monitor means, the solar array bus lockup determining means including a reference voltage generating means for generating a reference voltage representing the regulated bus voltage when the system is not in the solar array bus lockup state with the bus voltage being regulated by the shunt device, and calculating the effective generated power of the solar cell means and the load power consumed by the load on the basis of the regulated bus voltage, the monitored bus voltage, the monitored discharge current, and either of the monitored solar array current or the monitored load current to generate a solar array bus lockup signal at the output terminal when the effective generated power is greater than the load power; and a solar array bus lockup cancelling drive means which has an input terminal connected to the output terminal of the storage battery means, an output terminal connected to the power bus, and a control terminal connected to the output terminal of the solar array bus lockup determining means, the solar array bus lockup cancelling drive means responding to the solar array bus lockup signal to accumulate for a predetermined time solar array bus lockup cancelling drive energy supplied from the storage battery means and to discharge the solar array bus lockup cancelling drive energy to the power bus after the predetermined time has elapsed.
With the above construction, this solar cell power system is capable of being restored from a state in which, during a period of sunlight, its bus voltage is fixed to the output voltage of the power storage means and in which discharge from the storage battery means continues even though the solar cell means can manage to supply all the load current, to the state in which the bus voltage is regulated by the shunt device without temporarily reducing the magnitude of the load.
The above and other objects and features of this invention will be apparent from the following description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram showing the construction of a conventional solar cell power system;
FIG. 2 is a diagram showing the relationship between the power generated by the solar cell and the load power consumed by the load in the solar cell power system shown in FIG. 1;
FIG. 3 is a diagram showing the transition of the power operating point when the load fluctuates during a period of sunlight and the transition of the power operating point when solar array bus lockup occurs and is cancelled;
FIG. 4 is a diagram showing the construction of the first embodiment of the solar cell power system with a solar array bus lockup cancelling mechanism in accordance with this invention;
FIG. 5 is a diagram showing the construction of the second embodiment of the solar cell power system with a solar array bus lockup cancelling mechanism in accordance with this invention;
FIG. 6 is a diagram showing the construction of the third embodiment of the solar cell power system with a solar array bus lockup cancelling mechanism in accordance with this invention;
FIG. 7 is a diagram showing the construction of the fourth embodiment of the solar cell power system with a solar array bus lockup cancelling mechanism in accordance with this invention; and
FIG. 8 is a diagram showing the construction of the fifth embodiment of the solar cell power system with a solar array bus lockup cancelling mechanism in accordance with this invention.
In the drawings, the same reference numerals indicate the same or equivalent components.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 4 shows the construction of a first embodiment of the solar cell power system with a solar array bus lockup cancelling mechanism in accordance with this invention. In the drawing, the elements 1 to 13 are identical with those of the conventional system described with reference to FIG. 1, so that a description thereof will be omitted here. The reference numeral 14a indicates a solar array bus lockup determining device, which is connected to a charge/discharge current monitor 12, a bus voltage monitor 13, a load current monitor 11 and a load 9. This solar array bus lockup determining device 14a is composed of a reference power source 15, a first multiplier 16a, a second multiplier 16b, a comparator 17a and a subtracter 18a.
In the following, this solar array bus lockup determining device 14a will be described in detail.
The subtracter 18a is connected to the telemetry output terminal of the load current monitor 11 and the telemetry output terminal of the charge/discharge current monitor 12, subtracting the telemetry I CTLM of the charge/discharge current monitor 12 from the telemetry I LTLM of the load current monitor 11 and transmitting the result (I LTLM -I CTLM ) to the first multiplier 16a. This first multiplier 16a is connected to the output terminal of the subtracter 18a and the output terminal of the reference power source 15 where it multiplies the output of the subtracter 18a (I LTLM -I CTLM ) by the output V REF of the reference power source 15, supplying a signal P S1 to the comparator 17a.
The second multiplier 16b is connected to the output terminal of the bus voltage monitor 13 and the telemetry output terminal of the load current monitor 11 and multiplies the output V BUSTLM of the bus voltage monitor 13 by the telemetry I LTLM of the load current monitor 11, supplying a signal P L1 to the comparator 17a.
The comparator 17a compares the output P S1 of the first multiplier 16a with the output P L1 of the second multiplier 16b, and when the condition:
P.sub.S1 >P.sub.L1 (2)
is attained, supplies a load power reducing signal to the load 9.
The input signals I LTLM , I CTLM , V BUSTLM and V REF , which are supplied to the subtracter 18a, the first multiplier 16a and the second multiplier 16b, are respectively related in the following manner to the actual load current I L , the discharge current I D of the storage battery 2, the bus voltage V BUS , and the regulated bus voltage V SHNT obtained by the shunt device 6:
I.sub.LTLM =K.sub.1 ·I.sub.L (3)
I.sub.CTLM =K.sub.1 ·I.sub.D (4)
V.sub.BUSTLM =K.sub.2 ·V.sub.BUS (5)
V.sub.REF =K.sub.2 ·V.sub.SHNT (6)
In equations (3) to (5), K 1 and K 2 are constant transformation coefficients used when transforming the actual current levels or voltage levels to telemetries. The output V REF of the reference power source 15 is set in such a manner that it satisfies equation (6).
The input signals P S1 and P L1 to be supplied to the comparator 17a can be obtained from equations (3) to (6) as follows:
P.sub.S1 =K.sub.1 ·K.sub.2 ·V.sub.SHNT ·(I.sub.L -I.sub.D) (7)
P.sub.L1 =K.sub.1 ·K.sub.2 ·V.sub.BUS ·I.sub.L(8)
In equation (7), (I L -I D ) is obtained by subtracting the discharge current of the storage battery 2 from the actual load current, so that, in the solar array bus lockup condition, its value is equal to the actual solar array current I SA that actually flows from the solar cell 1 into the power bus 4.
That is, in the solar array bus lockup condition, P S1 indicates a value equivalent to the effective generated power of the solar cell 1 and P L1 indicates a value equivalent to the load power of the load 9.
In consideration of the above, equations (7) and (8) may be substituted in equation (2) and I L -I D may be replaced by I SA , thereby obtaining equation (1), which is none other than the criterion for solar array bus lockup.
Thus, when solar array bus lockup has occurred, the condition of equation (2) holds true. As a result, a load power reducing signal is transmitted from the comparator 17a to the load 9, reducing the magnitude of the load automatically. When the magnitude of the load has been reduced and the solar array bus lockup state cancelled, the discharge of the storage battery 2 is stopped and the bus voltage becomes V SHNT , so that the condition shown in equation (2) does not hold true any longer, and the emission of the load power reducing signal from the comparator 17a is stopped.
FIG. 5 shows the construction of a second embodiment of the solar cell power system with a solar array bus lockup cancelling mechanism in accordance with this invention. In the drawing, the elements 1 to 13 are identical with those of the conventional system described with reference to FIG. 1, so that a description thereof will be omitted here. The reference numeral 14b indicates a solar array bus lockup determining device, which is connected to a charge/discharge current monitor 12, a bus voltage monitor 13, a load current monitor 11 and a load 9. This solar array bus lockup determining device 14b is composed of a reference power source 15, a first multiplier 16c, a second multiplier 16d, a comparator 17b, a first subtracter 18b and a second subtracter 18c.
In the following, this solar array bus lockup determining device 14b will be describe in detail.
The first subtracter 18b is connected to the telemetry output terminal of the load current monitor 11 and the telemetry output terminal of the charge/discharge current monitor 12, subtracting the telemetry I CTLM of the charge/discharge current monitor 12 from the telemetry I LTLM of the load current monitor 11 and transmitting the result (I LTLM -I CTLM ) to the first multiplier 16c.
The second subtracter 18c is connected to the telemetry output terminal of the bus voltage monitor 13 and the output terminal of the reference power source 15, subtracting the telemetry output V BUSTLM of the bus voltage monitor 13 from the output V REF of the reference power source 15 and transmitting the result (V REF -V BUSTLM ) to the first multiplier 16c.
The first multiplier 16c is connected to the output terminal of the first substracter 18b and the output terminal of the output terminal of the second subtracter 18c and multiplies the output (I LTLM -I CTLM ) of the first subtracter 18b by the output (V REF -V BUSTLM ) of the second subtracter 18c, supplying a signal P 12 to the comparator 17b.
The second multiplier 16d is connected to the telemetry output terminal of the bus voltage monitor 13 and the telemetry output terminal of the charge/discharge current monitor 12 and multiplies the output V BUSTLM of the bus voltage monitor 13 by the telemetry I CTLM of the charge/discharge current monitor 12, supplying a signal P B2 to the comparator 17b.
The comparator 17b compares the output P I1 of the first multiplier 16c with the output P B1 of the second multiplier 16d, and when the condition:
P.sub.I1 >P.sub.B1 (9)
is attained, supplies a load power reducing signal to the load 9.
The input signals I LTLM , I CTLM , V BUSTLM and V REF , which are applied to the first substracter 18b, the second subtracter 18c and the second multiplier 16d, are respectively related in the following manner to the actual load current I L , the discharge current I D of the storage battery 2, the bus voltage V BUS , and the regulated bus voltage V SHNT obtained by the shunt device 6:
I.sub.LTLM =K.sub.1 ·I.sub.L (10)
I.sub.CTLM =K.sub.1 ·I.sub.D (11)
V.sub.BUSTLM =K.sub.2 ·V.sub.BUS (12)
V.sub.REF =K.sub.2 ·V.sub.SHNT (13)
In equations (10) to (12), K 1 and K 2 are constant transformation coefficients used when transforming the actual current levels or voltage levels to telemetries. The output V REF of the reference power source 15 is set in such a manner that it satisfies equation (13).
The input signals P 11 and P B1 to be supplied to the comparator 17b can be obtained from equations (10) to (13) as follows:
P.sub.I1 =K.sub.1 ·K.sub.2 ·(V.sub.SHNT -V.sub.BUS)·(I.sub.L -I.sub.D) (14)
P.sub.B1 =K.sub.1 ·K.sub.2 ·V.sub.BUS ·I.sub.D(15)
In equation (14), (I L -I D ) is obtained by subtracting the discharge current of the storage batter 2 from the actual load current, so that, in the solar array bus lockup condition, it is equal to the solar array current I SA that actually flows from the solar cell 1 into the power bus 4.
That is, in the solar array bus lockup condition, P I1 indicates a value equivalent to the potential generated power of the solar cell 1 and P B2 indicates a value equivalent to the discharge power of the storage battery 2.
In consideration of the above, equations (14) and (15) may be substituted in equation (9) and K 1 ·K 2 ·V BUS ·(I L -I D ) may be added to both sides, thereby obtaining equation (1), which is none other than the criterion for solar array bus lockup.
Thus, when solar array bus lockup has occurred, the condition shown in equation (9) holds true. As a result, a load power reducing signal is transmitted from the comparator 17b to the load 9, reducing the magnitude of the load automatically. When the magnitude of the load has been reduced and the solar array bus lockup state cancelled, the discharge from the storage battery 2 is stopped and the bus voltage becomes V SHNT , so that the condition shown in equation (9) does not hold true any longer, which stops the emission of the load power reducing signal from the comparator 17b.
FIG. 6 shows the construction of a third embodiment of the solar cell power system with a solar array bus lockup cancelling mechanism in accordance with this invention. In the drawing, the elements 1 to 13 are identical with those of the conventional system described with reference to FIG. 1, so that a description thereof will be omitted here. The reference numeral 14c indicates a solar array bus lockup determining device, which is connected to a solar array current monitor 10, a charge/discharge current monitor 12, a bus voltage monitor 13 and a load 9. This solar array bus lockup determining device 14c is composed of a reference power source 15, a first multiplier 16e, a second multiplier 16f, a comparator 17c, and an adder 19.
In the following, this solar array bus lockup determining device 14c will be described in detail.
The first multiplier 16e is connected to the telemetry output terminal of the solar array current monitor 10 and the output terminal of the reference power source 15, where it multiplies the telemetry I SATLM of the solar array current monitor 10 by the output V REF of the reference power source 15, transmitting a signal P S2 to the comparator 17c.
The adder 19 is connected to the telemetry output terminal of the solar array current monitor 10 and the telemetry output terminal of the charge/discharge current monitor 12, adding the telemetry I SATLM of the solar array current monitor 10 to the telemetry I CTLM of the charge/discharge current monitor 12 and transmitting the result (I SATLM +I CTLM ) to the second multiplier 16f. The second multiplier 16f is connected to the output terminal of the adder 19 and the telemetry output terminal of the bus voltage monitor 13 and multiplies the output (I SATLM +I CTLM ) of the adder 19 by the output V BUSTLM of the bus voltage monitor 13, supplying a signal P L2 to the comparator 17c.
The comparator 17c compares the output P S2 of the first multiplier 16e with the output P L2 of the second multiplier 16f, and when the condition:
P.sub.S2 >P.sub.L2 (16)
is attained, supplies a load power reducing signal to the load 9.
The input signals V REF , I SATLM , I CTLM and V BUSTLM , which are supplied to the first multiplier 16e, the adder 19 and the second multiplier 16f, are respectively related in the following manner to the actual regulated bus voltage V SHNT obtained by the shunt device 6, the solar array current I SA , the discharge current I D of the storage battery 2 and the bus voltage V BUS :
I.sub.SATLM =K.sub.1 ·I.sub.SA (17)
I.sub.CTLM =K.sub.1 ·I.sub.D (18)
V.sub.BUSTLM =K.sub.2 ·V.sub.BUS (19)
V.sub.REF =K.sub.2 ·V.sub.SHNT (20)
In equations (17) to (19), K 1 and K 2 are constant transformation coefficients that are used when transforming the actual current levels or voltage levels to telemetries. The output V REF of the reference power source 15 is set in such a manner that it satisfies equation (20).
The input signals P S2 and P L2 to be supplied to the comparator 17c can be obtained from equations (17) to (20) as follows:
P.sub.S2 =K.sub.1 ·K.sub.2 ·V.sub.SHNT ·I.sub.SA(21)
P.sub.L2 =K.sub.1 ·K.sub.2 ·V.sub.BUS ·(I.sub.SA +I.sub.D) (22)
In equation (22), (I SA +I D ) is obtained by adding the discharge current of the storage battery 2 to the actual solar array current, so that, in the solar array bus lockup condition, it is equal to the actual load current I L that flows from the power bus 4 to the load 9.
That is, in the solar array bus lockup condition, P S2 indicates a value equivalent to the effective generated power of the solar cell 1 and P L2 indicates a value equivalent to the load power of the load 9.
In consideration of the above, equations (21) and (22) may be substituted in equation (16) and I SA +I D may replaced by I L , thereby obtaining equation (1), which is none other than the criterion for solar array bus lockup.
Thus, when solar array bus lockup has occurred, the condition shown in equation (16) holds true. As a result, a load power reducing signal is transmitted from the comparator 17c to the load 9, automatically reducing the magnitude of the load. When the magnitude of the load has been reduced and the solar array bus lockup state cancelled, the discharge of the storage battery 2 is stopped and the bus voltage becomes V SHNT , so that the condition shown in equation (16) does not hold true any longer, and the emission of the load power reducing signal from the comparator 17c is stopped.
FIG. 7 shows the construction of a fourth embodiment of the solar cell power system with a solar array bus lockup cancelling mechanism in accordance with this invention. In the drawing, the elements 1 to 13 are identical with those of the conventional system described with reference to FIG. 1, so that a description thereof will be omitted here. The reference numeral 14d indicates a solar array bus lockup determining device, which is connected to a solar array current monitor 10, a charge/discharge current monitor 12, a bus voltage monitor 13 and a load 9. This solar array bus lockup determining device 14d is composed of a reference power source 15, a first multiplier 16g, a second multiplier 16h, a comparator 17d, and a subtracter 18d.
In the following, this solar array bus lockup determining device 14d will be described in detail.
The subtracter 18d is connected to the output terminal of the reference power source 15 and the telemetry output terminal of the bus voltage monitor 13 and subtracts the telemetry output V BUSTLM of the voltage monitor 13 from the output V REF of the reference power source 15, transmitting the result (V REF -V BUSTLM ) to the first multiplier 16g.
The first multiplier 16g is connected to the output terminal of the subtracter 18d and the output terminal of the solar array current monitor 10 and multiplies the output (V REF -V BUSTLM ) of the subtracter 18d by the output I SATLM of the solar array current monitor 10, supplying a signal P I2 to the comparator 17d.
The second multiplier 16h is connected to the telemetry output terminal of the bus voltage monitor 13 and the telemetry output terminal of the charge/discharge current monitor 12 and multiplies the output V BUSTLM of the bus voltage monitor 13 by the output I CTLM of the charge/discharge current monitor 12, supplying a signal P B2 to the comparator 17d.
The comparator 17d compares the output P I2 of the first multiplier 16g with the output P B2 of the second multiplier 16h, and when the condition:
P.sub.I2 >P.sub.B2 (23)
is attained, supplies a load power reducing signal to the load 9.
The input signals V REF , I SATLM , I CTLM and V BUSTLM , which are supplied to the subtracter 18d, the first multiplier 16g and the second multiplier 16h, are respectively related in the following manner to the actual regulated bus voltage V SHNT obtained by the shunt device 6, the solar array current I SA , the discharge current I D of the storage battery 2 and the bus voltage V BUS :
I.sub.SATLM =K.sub.1 ·I.sub.SA (24)
I.sub.CTLM =K.sub.1 ·I.sub.D (25)
V.sub.BUSTLM =K.sub.2 ·V.sub.BUS (26)
V.sub.REF =K.sub.2 ·V.sub.SHNT (27)
In equations (24) to (26), K 1 and K 2 are constant transformation coefficients that are used when transforming the actual current levels or voltage levels to telemetries. The output V REF of the reference power source 15 is set in such a manner that it satisfies equation (27).
The input signals P I2 and P B2 to be supplied to the comparator 17d can be obtained from equations (24) to (27) as follows:
P.sub.I2 =K.sub.1 ·K.sub.2 ·(V.sub.SHNT -V.sub.BUS)·I.sub.SA (28)
P.sub.B2 =K.sub.1 ·K.sub.2 ·V.sub.BUS ·I.sub.D(29)
That is, in the solar array bus lockup condition, P I2 indicates a value equivalent to the potential generated power of the solar cell 1 and P B2 indicates a value equivalent to the discharge power of the storage battery 2.
In the solar array bus lockup condition, the following relationship is established between the solar array current I SA , the discharge current I D of the storage battery 2 and the load current I L :
I.sub.SA =I.sub.L -I.sub.D (30)
In consideration of the above equation (30), equations (28) and (29) may be substituted in equation (23) and K 1 ·K 2 ·V BUS ·(I L -I D ) may be added to both sides, thereby obtaining equation (1), which is none other than the criterion for solar array bus lockup.
Thus, when solar array bus lockup has occurred, the condition shown in equation (23) holds true. As a result, a load power reducing signal is transmitted from the comparator 17d to the load 9, automatically reducing the magnitude of the load. When the magnitude of the load has been reduced and the solar array bus lockup state cancelled, the discharge of the storage battery 2 is stopped and the bus voltage becomes V SHNT , so that the condition shown in equation (23) does not hold true any longer, which stops the emission of the load power reducing signal from the comparator 17d.
As described above, the solar array bus lockup determining device 14a of the first embodiment is composed of one reference power source 15, two multipliers 16a, 16b, one comparator 17a, and one subtracter 18a, utilizing, as input data, the respective telemetries of the load current monitor 11, the charge/discharge current monitor 12 and the bus voltage monitor 13 of the solar cell power system. The solar array bus lockup determining device 14b of the second embodiment is composed of one reference power source 15, two multipliers 16c, 16d, one comparator 17b, and two subtracters 18b, 18c, utilizing, as input data, the respective telemetries of the load current monitor 11, the charge/discharge current monitor 12 and the bus voltage monitor 13 of the solar cell power system. The solar array bus lockup determining device 14c of the third embodiment is composed of one reference power source 15, two multipliers 16e, 16f, one comparator 17c, and one adder 19, utilizing, as input data, the respective telemetries of the solar array current monitor 10, the charge/discharge current monitor 12 and the bus voltage monitor 13 of the solar cell power system. The solar array bus lockup determining device 14d of the fourth embodiment is composed of one reference power source 15, two multipliers 16g, 16h, one comparator 17d, and one subtracter 18d, utilizing, as input data, the respective telemetries of the solar array current monitor 10, the charge/discharge current monitor 12 and the bus voltage monitor 13 of the solar cell power system. When solar array bus lockup has occurred, these solar array bus lockup determining devices 14a to 14d supply a load power reducing signal to the load 9 to control the magnitude of the load, thereby determining the occurrence of solar array bus lockup automatically and cancelling it without causing the function of the load to be lost for a long period or depending on support from a ground station.
In the first to the fourth embodiment described above, a solar array bus lockup cancelling mechanism in accordance with this invention is incorporated into a solar cell power system whose load 9 can be reduced. In some cases, however, the load 9 cannot be reduced.
FIG. 8 shows the construction of a fifth embodiment of this invention in which a solar array bus lockup cancelling mechanism in accordance with this invention is incorporated into a solar cell power system of the type in which load reduction is impossible or in which from the operational viewpoint, it is preferable, not to reduce the load. In the drawing, the elements 1 to 13 are identical with those of the conventional system described with reference to FIG. 1, so that an explanation thereof will be omitted here. The load 9 may consist of a fixed load since it naturally operates as such. The solar array bus lockup determining device 14 of this embodiment is identical with the solar array bus lockup determining device 14c shown in FIG. 6 or the solar array bus lockup determining device 14d shown in FIG. 7. The reference numeral 20 indicates a solar array bus lockup cancelling drive device, which is composed of a drive 21, a transistor 22, a coil 23 and a third diode 24.
In the following, this solar array bus lockup cancelling drive device 20 will be described in detail.
The drive 21 is connected to the output terminal of the solar array bus lockup determining device 14 through which a solar array bus lockup signal is emitted (more specifically, the output terminal of the comparator 17c shown in FIG. 6 or of the comparator 17d shown in FIG. 7) and, is connected to the base of the transistor 22. The emitter of the transistor 22 is connected to the RTN and the collector thereof is connected to the node between the coil 23 and the anode of the third diode 24. The other end of the coil 23, which is not connected to the diode 24, is connected to the node between the anode of the second diode 5 and the charge/discharge current monitor 12. The cathode of the third diode 24 is connected to the power bus 4.
When solar array bus lockup occurs, the drive 21 receives a solar array bus lockup signal from the solar array bus lockup determining device 14 and responds to this signal to drive the base of the transistor 22 to cause the transistor 22 to be conducted for a certain period T ON , short-circuiting its collector.
Here, the following relationship exists between the solar array current I SA , the voltage V BAT of the storage battery 2, the current I DO supplied from the storage battery 2 to the power bus 4 through the charge/discharge current monitor 12 and the second diode 5, the current I DL flowing from the storage battery 2 through the charge/discharge current monitor 12, the coil 23 and the transistor 22, the short-circuit period T ON of the transistor 22, the load power P1, the inductance L of the coil 23, and the energy W L stored in the coil 23: ##EQU1## When the transistor 22 has been opened, the energy W L stored in the coil 23 is supplied to the power bus 4 through the third diode 24. If T ON and L are selected such that the current I DL which the coil 23 supplies to the power bus is greater than I DO , the capacitor bank 8 begins to be charged with a current "I DL -I DO " and the bus voltage V BUS increases. As a result, the power operating point of FIG. 3 moves from point C (which, as described with reference to the prior art, is the operating point when the power consumption is increased from P1 to P2 and then reduced to P1) to the point F. As a result of the increase of V BUS , the power supply P SA from the solar array increases as follows:
P.sub.SA =V.sub.BUS ·I.sub.SA (34)
Thus, supposing the time t at which the transistor 22 has become open is 0, V BUS continues to increase, as indicated by equations (33) and (34), as long as there exists, after the opening of the transistor 22, the following energy relationship between the solar array power supply P SA , the accumulated energy W L of the coil 23 and the load power P1: ##EQU2## and thus the power operating point of FIG. 3 moves from C to F, then to A. When V BUS has become higher than the power operating point F of FIG. 3 by even the slightest degree, the power P1 to be supplied to the load 9 can be provided solely by the power "V BUS ·I SA " from the solar cell 1 consisting of a solar array and, due to the surplus power control effected by the shunt device 6, the power operating point of FIG. 3 moves to the point A in the line M--M', thus releasing the system from the solar array bus lockup state.
Thus, by adjusting the inductance L of the coil 23 and the short-circuiting time T ON of the transistor 22 and accumulating in the coil 23 energy that increases V BUS to or beyond the power operating point F of FIG. 3, the system can be automatically released from the solar array bus lockup state without reducing the load 9.
As described above, the solar array bus lockup cancelling device of the fifth embodiment operates as follows: when the load current temporarily becomes greater than the power generated by the solar cell 1 so that the bus voltage is fixed to the voltage of the storage battery 2, a solar array bus lockup signal emitted from the solar array bus lockup determining device 14 is supplied to the drive 21 of the solar array bus lockup cancelling drive device 20, which causes the transistor 22 to be short-circuited for a certain period with the result that energy is accumulated in the coil 23. The energy accumulated in the coil 23 charges the capacitor bank 8 through the third diode 24, causing the bus voltage to increase. As a result, the bus voltage is restored to a voltage which is at the level when the power supply to the load 9 is performed solely with the output power of the solar cell 1 while being regulated by the shunt device 6. Accordingly, the solar array bus lockup state can be cancelled without reducing the magnitude of the load.
Instead of the solar array current, the load current may be used for the purpose of determining the occurrence of solar array bus lockup, as in the first and second embodiments. In that case, the solar array bus lockup determining device 14 of FIG. 8 may consist of the solar array bus lock-up determining device 14a or 14b shown in FIG. 4 or FIG. 5, with the telemetry I LTLM from the load current monitor 11 being received by the device 14, as indicated by the broken line of FIG. 8, instead of I SATLM from the solar array current monitor 10.
Although the invention has been described in detail with reference to some of its embodiments, it is to be understood that the scope of the invention is not limited to the above description. It should be obvious that various changes and modifications may be made by those skilled in the art without departing from the scope and spirit of the invention. | 4y
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Application Ser. No. 61/313,199 filed Mar. 12, 2010, the contents of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention relates to latent hardeners for epoxy resins and, more particularly, to latent hardeners comprised of a core material that is encapsulated or coated in a step-wise manner with two or more shell materials.
BACKGROUND OF THE INVENTION
[0003] Epoxy adhesives have been known for over 50 years and were one of the first high temperature adhesives to become commercialized. Once cured, the material retains its adhesive properties over a large range of temperatures, has high shear strengths, and is resistant to weathering, oil, solvents, and moisture. The adhesive is available commercially as either a 1-part adhesive or 2-part adhesive and is available in several forms, such as pastes, solvent solutions, and supported films. Of the three forms, the 1-part adhesive film generally provides good adhesive strength with better thickness uniformity and has found practical use in the development of anisotropic conducting films for electronics, most notably flat panel displays.
[0004] To construct a 1-part adhesive film, one typically combines all at once, a latent hardener, multi-functional epoxy resins, phenoxy resins, additives, and optionally fillers. This composition is then cast as a film on a release layer. During the bonding process, the adhesive is transferred to one particular surface and the release layer removed. Another surface is brought into contact with the film, and the adhesive hardened or cured into a strong thermosetting adhesive through the application of heat and/or pressure. In this example, the two components of the adhesive that enable the material to cure into a thermoset adhesive are the hardener and the multi-functional epoxy. It is the later, that sets up the cross-linked network, but it is the former that enables this to happen. During the curing process, the latent hardener initiates the polymerization of the multi-functional epoxy by first forming ring-opened adducts with the oxiranes of the epoxy resin. Once produced, the addition products cause a cascade of ring-opened species that propagate through the adhesive, finally producing a cross-linked thermoset material.
[0005] The active ingredient of the hardener is usually comprised of the reaction product of an amine compound, like an imidazole, and an epoxy resin. Such adducts are known to initiate and accelerate the cure of epoxy resins (Heise, M. S.; Martin, G. C. Macromolecules, 1989, 22 99-104; Heise, M. S.; Martin, G. C. J. Poly. Sci.: Part C: Polym. Lett. 1988, 26, 153-157; Barton, J. M; Shepherd, P. M.; Die Makromolekular Chemie 1975 176, 919-930). One drawback of these however is that they are so effective as curatives they cannot be used directly into a 1-part adhesive because once added, they would start to kick-off the cure in a relative short period of time. What one would see therefore is a slow increase in the viscosity of the composition, while one is attempting to make the adhesive and its film, as the hardener continues to accelerate the ring-opening polymerization of the epoxy moieties. This phenomenon is most commonly referred to as reduced workable lifetime, in other words, the time available to assemble the adhesive and make the film was dramatically reduced because of premature hardening. Therefore, to stop this from happening, one usually does not use amine-epoxy adducts themselves as hardeners, but instead what is typically done is to encapsulate or coat the amine-epoxy adduct with a protective shell of material that sequesters the amine-epoxy adduct from the adhesive environment. Once incorporated into the adhesive, the amine-epoxy adduct is released from its protective shell through the application of heat and/or pressure. Such latent hardeners described here are commonly called to as a core-shell latent hardener, where the core in this case is an amine-epoxy adduct and the shell is the protective shell.
[0006] There is one significant trade-off often encountered with core-shell latent hardeners, which is the cure speed is often slowed and the cure temperature often increased because of the inclusion of a protective shell, which must be broken or rendered permeable in order to allow the core material to be released into the adhesive environment or matrix. Without being bound by any particular theory, it is well known that as one increases the barrier properties of the shell material using such means, like increasing the thickness of the shell, cross-linking density, or T g of the shell, or by increasing the degree of incompatibility between the shell and the core material or the adhesive matrix, it takes more energy to release the amine-epoxy adduct into the adhesive environment. What one has therefore is a hardener that when formulated into a 1-part adhesive has the desired property of increased shelf life stability, but at the expense of a lower curing temperature and a reduction of cure speed. Therefore, it continues to be a constant balance to prepare a core-shell latent hardener that has just enough of a protective shell to protect the core material at normal storage conditions, but not too much as to slow down the cure speed of the adhesive. Also, the release of the core material may be triggered at a reasonably low temperature and completed within a narrow temperature range.
[0007] One of the most frequently used core-shell latent hardeners are those comprised of core-shell materials, as described in U.S. Pat. No. 4,833,226, U.S. Pat. No. 5,219,956, US 2006/0128835, US 2007/0010636, US 2007/0055039, US 2007/0244268, EP 1,557,438, EP 1,731,545, EP 1,852, 452, and EP 1,980,580. The hardeners described here are obtained, first by the synthesis of a lump of core material, which is then pulverized into micro-sized particles that are irregular in shape. The core material is the reaction product of an amine compound and an epoxy resin and said core material functions as a hardener for epoxy compositions, such as that found in adhesives and coatings. To improve the storage stability of the core material and prevent premature curing, it is encapsulated with a shell of a material that is impervious to components of the epoxy composition, such as solvent, diluent, low molecular weight epoxides and additives. To accomplish this, the pulverized solid is added to a mixture of polyfunctional isocyanate, an active hydrogen compound, like water, and an epoxy resin. The chemistry of said encapsulation procedure relies on the cross-linking reactions and/or hydrolysis of the polyisocyanate compound to form a cross-linked shell coating around the particles. Typical cross-linking structures of the shell include, but are not limited to, urea, urethane, carbamate, biuret, allophanate, etc. However, the crosslinking reactions take places randomly without discrimination in the continuous phase and at the interface. It is highly likely that some core particles are not fully encapsulated, while unwanted byproducts such as crosslinked polyurea particles are produced in the continuous phase. Moreover, the core particles prepared by this process are of irregular shape with a very broad distribution of shape and particle size, the uniformity of the thickness and crosslinking density of the shell formed thereon is very poor. As a result, the encapsulated hardener particles typically show a very broad distribution of release property and the 1-part adhesive formulated with this type of hardener capsules often shows poor shelf-life stability and a sluggish curing profile or a high curing temperature.
[0008] There is another group of inventions, namely EP 459,745, EP 552,976, U.S. Pat. No. 5,357,008, U.S. Pat. No. 5,480,957, U.S. Pat. No. 5,548,058, U.S. Pat. No. 5,554,714, U.S. Pat. No. 5,561,204, U.S. Pat. No. 5,567,792, and U.S. Pat. No. 5,591,814, that also describe core shell latent hardeners, which unlike those above are spherical in shape. The core material is obtained as a spherical particle and is synthesized from the reaction of an amine with an active hydrogen atom (e.g., imidazole) and an epoxy resin, in an organic medium and in the presence of a dispersant. The amine, epoxy resin, and dispersant are soluble in the organic medium, while the reaction product, the core material, is not, and as a result the core particle precipitates out from solution as a stable dispersion with a relatively narrow size distribution. The most important factor to make a stable dispersion of desirable particle size with a narrow size distribution is the nature of the dispersant and the inventors show examples that use dispersants from the class of graft of polyacrylates, polyacrylamides, polyvinyl acetates, polyethylene oxides, polystyrenes, and polyvinyl chlorides. Once isolated, the spherical core material is encapsulated with an isocyanate to prepare a spherical core-shell latent hardener.
[0009] One disadvantage of the aforementioned latent hardeners is the need of the shell material to be free of defects, such as such as holes, voids, thin areas, or areas comprised of insufficient cross-link density. These defects would enable the core to escape from the protective shell prematurely, either during processing or storage of the finished article. Either way, this premature release of core from the encapsulated latent hardener would show up as a loss of storage stability and shelf-life (in the case of a 1-part epoxy adhesive). This deficiency; however, can be overcome by the application of additional and successive layers of the shell material over the preexisting shell, thus filling in and coating the defects with an additional layers shell material.
[0010] Another limitation of the prior art is that in an attempt to make the protective shell more impervious and thereby improving its barrier properties, the compatibility of the shell with the surrounding epoxy composition was neglected. The prior art teaches encapsulation in the presence of an isocyanate, and optionally water and additional epoxy. What one then obtains is a shell comprised of a cross-linked polyurethane and optionally a polyurea. When formulated into an epoxy adhesive, the now hard and highly cross-linked shell could have poor capability with the surrounding epoxy. An example of this would be a mismatch of surface tensions between the surface of the shell and the epoxy; which would show up as a dewetting phenomenon in which the epoxy fails to adequately wet and spread over the surface of the shell material. As a consequence therefore one would see that after curing, the adhesive would contain voids and regions of inhomogeneous curing, both of which would lead to a reduction of adhesive strength.
[0011] There remains a need for core-shell latent hardeners with improved barrier properties to prevent premature cure. Additionally, there is a need of encapsulated latent hardeners with improved epoxy compatibility.
SUMMARY OF THE INVENTION
[0012] This invention relates to latent hardeners or catalysts for thermosets such as epoxy resins and, more particularly, to latent hardeners or catalysts comprised of a core material that is encapsulated or coated with two or more shell materials. The core material, which is a curative for epoxy resins, is further comprised of the reaction product of an amine (e.g., imidazoles, piperazines, primary aliphatic amines, and secondary aliphatic amines) and an epoxy resin. In one embodiment, the core material is synthesized in an organic medium and in the presence of a dispersant which is the reaction product of carboxyl terminated poly(butadiene-co-acrylonitrile) (CTBN) and an epoxy resin. In one embodiment, the reaction product of a CTBN and an epoxy resin is capable of providing a stable dispersion of spherical-shaped core particles with a narrow size distribution. In another embodiment near 100% conversion is obtained by using a slight excess of epoxy. In another embodiment, the spherical-shaped core particles are encapsulated by reacting with a multi-functional isocyanate or thioisocyanate. Optionally, an epoxy resin is added at the same time as the isocyanate to build up the thickness of the encapsulated shell. In still another embodiment, once formed, the core material is fully encapsulated with two or more shell materials that are applied in a step-wise manner using a multi-functional isocyanate, or a mixture of isocyanate and multi-functional epoxy resin, or a mixture of an isocyanate and epoxy compatible material, such as CTBN or polyacrylate modified epoxy, or a mixture of an isocyanate, multi-functional epoxy, and an epoxy compatible material. Curable compositions prepared using the particles have excellent storage stability and improved curing properties.
[0013] One aspect of this disclosure relates to an improvement to the barrier properties and solvent resistance of a latent hardener or catalyst.
[0014] Another aspect of this disclosure relates to an improvement of barrier properties and solvent resistance of a latent hardener or catalyst.
[0015] Another aspect of this disclosure relates to an improvement of compatibility of the latent hardener or catalyst with an epoxy resin or composition.
[0016] Another aspect of this disclosure relates to a latent hardener or catalyst of a spherical-shape and which is fully encapsulated.
[0017] Another aspect of this disclosure relates to a latent hardener or catalyst that releases the core material at the desired temperature, pressure, or combination of both.
[0018] Another aspect of this disclosure relates to a latent core-shell latent hardener or catalyst, wherein the hardener or catalyst is comprised of a stable dispersion of spherical-shaped particles.
[0019] Another aspect of this disclosure relates to a process of making spherical-shaped core particles using a dispersant, wherein said dispersant is the reaction product (adduct) of a carboxyl-terminated butadiene-acrylonitrile rubber (CTBN) and an epoxy resin.
[0020] Another aspect of this disclosure relates to a curing agent comprised of an amine compound, an epoxy resin, and a dispersant, wherein said dispersant is the adduct of CTBN and an epoxy resin.
[0021] Another aspect of this disclosure relates to a process for making the curing agent.
[0022] Another aspect of this disclosure relates to a masterbatch that is comprised of the curing agent.
[0023] Another aspect of this disclosure relates to an electronic device or a flat panel display comprising the composition that is comprised of the curing agent disclosed herein. For example a common method that is used to connect the driver integrated circuit (IC) to the electronic device or flat panel display is through the use of either a chip-on-glass (COG) or chip-on-film (COF). In the constructions of the COG and COF, anisotropic conducing film adhesives (ACF) and non-conducting film adhesives (NCF) are typically used to attach the COG or COF to the driver IC and it is the curing agent that enables the adhesives to cure and produce a permanent bond between the components. Accordingly, in one embodiment, the integrated circuit chip or other electronic component is attached using an epoxy adhesive containing the curing agent described herein.
[0024] Another aspect of this disclosure relates to a composition containing the curing agent, where the composition is an adhesive, conducting adhesive, composite, molding compound, anisotropic conducting film (ACF) adhesive, non-random array ACF, non-conductive adhesive film (NCF), coating, encapsulant, underfill material, lead or free solder.
[0025] Another aspect of this disclosure relates to a circuit board comprising an epoxy adhesive composition comprised of the curing agent that is disclosed herein. Traditionally, the electronic components, such as resistor, capacitor, and IC are assembled to the circuit board through a soldering process. This process requires high temperature and generates waste. However, an ACF, NCF or conductive adhesive containing the disclosed curing agent provides an alternative method to mount the electronic components on the circuit board without the use to high temperatures, waste, and toxic heavy metals. In this application, ACF and NCF provide the electrical contact and secure the component to the board.
[0026] Another aspect of this disclosure relates to an electronic device or display which is assembled using an epoxy adhesive composition that contains the curing agent disclosed herein.
[0027] Another aspect of this disclosure relates to a flip chip comprising the adhesive composition containing the curing agent disclosed herein. Traditionally a flip chip is a chip that mounted to the substrate in two steps. First, the chip is bonded to the substrate through soldering or eutectic bonding. Underfill material, typically in liquid form, is then filled in the gap and cured between the chip and the substrate. Replacing the soldering or eutectic bonding process with an ACF or NCF containing the disclosed curing agent is an alternative method to accomplish the first step. Not only does the adhesive approach provided advantages encountered with circuit boards, but the ACF and NCF also function as the underfill material to fill the gap between the chip and the substrate thereby accomplishing the process in a single step, where two were used before.
[0028] Another aspect of this disclosure relates to an electronic device or display where the composition is cured, partially cured, or un-cured and is comprised of the curing agent.
[0029] Another aspect of this disclosure relates to a semiconductor device, such as a high definition LCD, Electronic Paper (ePaper), mini projectors, and cell phones that are comprised of flat panel displays, electronic devices, circuit boards, and flip chips in which an epoxy adhesive containing the curing agent disclosed herein is used as described above.
[0030] Another aspect of this disclosure is a fixed array ACF, where the fixed array ACF is an ACF wherein the gold particles are dispersed in the adhesive film in a predetermined pattern, such as that described in Trillion's patent application 2006/0280912 A1 wherein an epoxy adhesive containing the curing agent disclosed herein is used to construct the array.
[0031] Another aspect of this disclosure is a High T g 1-part molding compound comprising a protected phenolic compound as described in U.S. application Ser. No. 12/008,375 filed Jan. 10, 2008 which is herein incorporated by reference, where the protected phenolic compound comprises an aryl glycidyl carbonate moiety, and the curing agent disclosed herein.
[0032] Still another aspect of this disclosure are 1-part composites, including prepreg composites and molding compounds, such as sheet molding compounds (SMC), bulk molding compounds (BMC), and dough molding compounds (DMC) wherein the curing agent is the curing agent disclosed herein.
[0033] Still another aspect of the disclosure is adhesives and coating applications, including solder mask and impregnation coatings in which the curing agent is the curing agent disclosed herein.
[0034] Another aspect of this disclosure employs epoxy resins containing the curing agent disclosed herein in assembly and packaging for semi-conductor applications such as described in Colclaser, Roy A.; “ Microelectronics Processing and Device Design ”; John Wiley & Sons, Publishers: New York, 1980; Chapter 8, page pp. 163-181.
[0035] Another aspect of this disclosure relates to the circuit board where the composition is cured, partially cured, or un-cured and is comprised of the curing agent disclosed herein.
[0036] Another aspect of this disclosure relates to a flip chip where the epoxy adhesive composition described herein is cured, partially cured, or un-cured and is comprised of the curing agent.
[0037] Another aspect of this disclosure relates to a semiconductor device comprising the composition containing the curing agent. Another aspect of this disclosure relates to a semiconductor device where the composition is cured, partially cured, or un-cured and is comprised of the curing agent.
[0038] Another aspect of this disclosure relates to a composition, where the composition is a 1-part adhesive composition having a substantially long shelf-life at storage conditions and the composition is reactive at either the curing temperature or the molding temperature, and the composition contains the curing agent disclosed herein.
[0039] Another aspect of this disclosure relates to a composition containing the curing agent, where after cure the composition shows adhesion at interfaces, low shrinkage on cure, and low coefficient of thermal expansion (CTE).
[0040] Another aspect of this disclosure relates to a composition containing the curing agent, where the composition is a matrix for a composite material or molding compound.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1 is a drawing showing a core material encapsulated with two protective shell materials. In the case for improved latent hardener compatibility the composition of protective shell 2 is selected such that is comprised of an epoxy compatible material, while the composition of shell 1 is selected based only on its barrier properties.
[0042] FIG. 2 is an electron micrograph of core particles of spherical shape comprised of 2-methylimidazole, diglycidyl ether of bisphenol A (DGEBA), and the CTBN-epoxy adduct isolated from CVC Thermoset Materials HyPox™ RK84.
[0043] FIG. 3 is an electron micrograph of core particles of spherical shape comprised of 2-methylimidazole, diglycidyl ether of bisphenol A (DGEBA), and the CTBN-epoxy adduct isolated from CVC Thermoset Materials HyPox™ RK84, wherein the core particle is encapsulated with 4,4′-methylenebis(phenyl isocyanate) (MDI).
[0044] FIG. 4 is an electron micrograph of a single core particle of spherical shape comprised of 2-methylimidazole, diglycidyl ether of bisphenol A (DGEBA), and the CTBN-epoxy adduct isolated from CVC Thermoset Materials HyPox™ RK84.
[0045] FIG. 5 is the chemical structure of a CTBN-epoxy adduct (c) where a hydroxyl-functional epoxy resin (b) such as that of CVC Thermoset Specialties HyPox RK84 is used in the synthesis along with CTBN (a). The residual unreacted epoxy resin (b) is removed prior to (c) being used as a dispersant.
[0046] FIG. 6 is the chemical structure of a CTBN-epoxy adduct (e) where disglydicyl ether of bisphenol A (d) such as that of CVC Thermoset Specialties HyPox RA1340 is used in the synthesis, along with CTBN (a).
DETAILED DESCRIPTION OF THE INVENTION
[0047] In accordance with one embodiment, the curing agent is an adduct of: (i) an amine, (ii) an epoxy compound, and (iii) an adduct of an elastomer and an epoxy resin. The elastomer/epoxy resin adduct functions as an reactive dispersant enabling the formation of a dispersion of spherical un-encapsulated particles in the reaction medium.
[0048] Another aspect of the invention is a method for the preparation of fine spherical core particles of a curing agent that comprises reacting an amine compound with an epoxy/elastomer adduct followed by an epoxy compound, in the presence of a continuous phase at elevated temperatures with agitation, and recovering fine spherical particles formed from the reaction mixture solution. Optionally, the recovered particles may be filtered to remove aggregated particles and classified by methods such as gravity fractionation, filtration, sedimentation, field flow fractionation, and field flow classification to remove small satellite particles. The continuous phase is an organic solvent or solvent mixture comprised of either a solvent capable of dissolving the amine compound, the epoxy compound and the epoxy/elastomer adduct but incapable of dissolving the adduct formed from the three reactants or a mixture of a solvent and non-solvent, where the solvent is capable of dissolving the amine compound, the epoxy compound and the epoxy/elastomer adduct but incapable of dissolving the adduct particles formed from the three reactants or a mixture and the non-solvent is a non-solvent for the amine compound, the epoxy compound, the epoxy/elastomer adduct, and the adduct particles formed from the three reactants. The selection of the continuous phase affects the dispersion stability and the particle size and particle size distribution.
[0049] Yet another embodiment of the invention is a heat curable composition that comprises, as its major components, an epoxy composition and spherical particles of the curing agent. In this case, the spherical particles of the curing agent of this invention are not soluble or swellable in the epoxy composition. In one embodiment the particles have a melting flow temperature of at least about 50° C. and a particle diameter of 0.1 μm to 30 μm. The particles are incorporated in the adhesive in an amount of about 1 to 60 parts by weight per 100 parts by weight of the epoxy resin.
[0050] The present invention also includes a curing agent masterbatch for epoxy resins wherein the masterbatch comprises a liquid epoxy resin in which fine spherical particles of the curing agent are uniformly dispersed. In a particular embodiment, the particles have been reacted with 1 to 100 parts by weight of a polyfunctional isocyanate compound, and optionally with 1-100 parts by weight of an epoxy compound, based on 100 parts by weight of said particles. The particles are then allowed to react one or more additional times in successive steps with 1 to 100 parts by weight of a polyfunctional isocyanate compound, and optionally with 1-100 parts by weight of a multifunctional epoxy compound, and optionally with 1-100 parts by weight of an epoxy compatible material, based on 100 parts by weight of said particles.
[0051] The present invention further includes a method for preparation of a curing agent masterbatch for epoxy resin with comprises the step of dispersing spherical particles of the curing agent in an epoxy resin at a temperature below the melt flow temperature of said spherical particles.
[0052] Curing Agent Epoxy Plus Amine Compound
[0053] In the present invention the amine compounds and the epoxy compounds which can be employed in the preparation of the curing agent are selected based on its chemical structure which promotes the curing reaction by anionic polymerization, its melting point, and its compatibility with the epoxy resin which will be cured in a molten or plasticized viscoelastic state, its quick curability and its reactivity. The melting flow temperature is defined herein as the temperature at which the substance begins to flow as a molten fluid, as determined by the conventional methods. Examples of amine and epoxy compounds useful in certain embodiments of the invention are disclosed in EP 459,745, EP 552,976, U.S. Pat. No. 5,357,008, U.S. Pat. No. 5,480,957, U.S. Pat. No. 5,548,058, U.S. Pat. No. 5,554,714, U.S. Pat. No. 5,561,204, U.S. Pat. No. 5,567,792, and U.S. Pat. No. 5,591,814, which are incorporated herein by reference.
[0054] Amine Compound
[0055] While any amine compound can be used, the selection of the amine will be based upon the nature of the epoxy compound. An amine is selected that reacts with the epoxy compound but enables the reaction without full polymerization. While it is possible to use substantially any amine compounds when reacting monofunctional epoxy compounds, when reacting polyfunctional epoxy compounds, an amine compound which has only one active hydrogen, i.e., a secondary amino group that contributes to the reaction of the epoxy group. Use of compounds having a tertiary amino group, i.e., having no active hydrogen, is also permitted. The following compounds are illustrative examples of amine compounds which can be combined with bifunctional bisphenol A diglycidyl ether: imidazoles represented by 2-methylimidazole and 2,4-dimethylimidazole, piperazines represented by N-methyl piperazine and N-hydroxylethyl-piperazine, anabasines represented by anabasine, pyrazoles represented by 3,5-dimethyl-pyrazole, purines represented by tetra-methyl-quanidine or purine, pyrazoles represented by pyrazole, and triazoles represented by 1,2,3-triazole, and the like.
[0056] Epoxy Compound
[0057] Examples of epoxy compounds are monofunctional epoxy compounds such as n-butyl glycidyl ether, styrene oxide and phenylglycidyl ether; bifunctional epoxy compounds such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether and diglycidyl phthalate; trifunctional compounds such as triglycidyl isocyanurate, triglycidyl p-aminophenol; tetrafunctional compounds such as tetraglycidyl m-xylene diamine and tetraglycidyldiaminodiphenylmethane; and compounds having more functional groups such as cresol novolac polyglycidyl ether, phenol novolac polyglycidyl ether and so on. The selection of epoxy is also determined by the type of the amine compound to be combined. The epoxy compounds are also selected based upon the softening point of the adduct formed and the compatibility in a molten state with respect to the epoxy resin which is to be cured. Since the majority of the epoxy resins to be cured comprise bisphenol A diglycidyl ether, this compound is most typically used as the starting material for the preparation of an adduct. In one embodiment, epoxy compounds having an epoxy equivalent weight of, at most about 1,000, and preferably at most about 500 are typically employed.
[0058] Solvent
[0059] It is also important to select a solvent system which can dissolve the amine compounds and the epoxy compound as the starting materials but can precipitate the adduct in the form of particles without dissolution. Examples of solvents that can be used in certain embodiments of the present invention are methyl isobutyl ketone, methyl isopropyl ketone, methyl ethyl ketone, acetone, n-butylacetate, isobutyl acetate, ethyl acetate, methyl acetate, tetrahydrofuran, 1,4-dioxane, cellosolve, ethyleneglycol monoethyl ether, diethyleneglycol dimethyl ether, anisole, toluene, p-xylene, benzene, methylene chloride, chloroform, trichloroethylene, chlorobenzene and pyridine. These solvents can be used alone, or two or more solvents can be used together.
[0060] Non-Solvent
[0061] Additionally a non-solvent may need to be added to assist with forcing the amine compound to react with the epoxy functionalities of the dispersion stabilizer and epoxy resin. A non-solvent in the case is any solvent that does not dissolve either the amine compound, dispersion stabilizer, or epoxy resin. One possible class of compounds that can be used as non-solvents are linear or branched aliphatic compounds such as heptane, hexane, octane, iso-octane, petroleum ether, and the like. One example of a non-solvent in combination with a solvent is a mixture of heptane and MIBK. In addition to the above-mentioned solvent and non-solvent, a diluent or a weak solvent may be optionally used to widen the formulation or process window.
[0062] Dispersion Stabilizer or Dispersant
[0063] The dispersion stabilizer or dispersant enables a stable dispersion of the adduct particles in the reaction medium. Without such a dispersion stabilizer, the particles of the adduct formed may aggregate and precipitate out as a viscous mass during the reaction, and thus the desired fine spherical particles cannot be obtained. An optimum dispersant is important for the preparation of a stable dispersion with a narrow particle size distribution. Reactive dispersants are often more effective than non-reactive dispersants since desorption or migration of the dispersant away from the particle surface is less likely once it reacts with the particle phase. Elastomer/epoxy adducts are used as reactive dispersants in accordance to this invention. A suitable molecular weight range of the reactive dispersant is from about 1,000 to 300,000, preferably from about 2,000 to 100,000, and most preferably from about 3,000 to 10,000.
[0064] Epoxy/Elastomer Adducts as Reactive Dispersants
[0065] The epoxy/elastomer adduct itself generally includes about 1:5 to 5:1 parts of epoxy or other polymer to elastomer, and more preferably about 1:3 to 3:1 parts of epoxy to elastomer. More typically, the adduct includes at least about 5%, more typically at least about 12% and even more typically at least about 18% elastomer and also typically includes not greater than about 50%, even more typically no greater than about 40% and still more typically no greater than about 35% elastomer, although higher or lower percentages are possible. The elastomer suitable for the adduct may be functionalized at either the main chain or the side chain. Suitable functional groups include, but are not limited to, —COOH, —NH 2′ —NH—, —OH, —SH, —CONH 2 , —CONH—, —NHCONH—, —NCO, —NCS, and oxirane or glycidyl group, etc. The elastomer optionally may be vulcanize-able or post-crosslink-able. Exemplary elastomers include, without limitation, natural rubber, styrene-butadiene rubber, polyisoprene, polyisobutylene, polybutadiene, isoprene-butadiene copolymer, neoprene, nitrile rubber, butadiene-acrylonitrile copolymer, butyl rubber, polysulfide elastomer, acrylic elastomer, acrylonitrile elastomers, silicone rubber, polysiloxanes, polyester rubber, diisocyanate-linked condensation elastomer, EPDM (ethylene-propylene diene rubbers), chlorosulphonated polyethylene, fluorinated hydrocarbons, thermoplastic elastomers such as (AB) and (ABA) type of block copolymers of styrene and butadiene or isoprene, and (AB)n type of multi-segment block copolymers of polyurethane or polyester, and the like. In the case that carboxyl-terminated butadiene-acrylonitrile (CTBN) is used as the functionalized elastomer, the preferable nitrile content is from 12-35% by weight, more preferably from 20-33% by weight.
[0066] An example of a preferred epoxide-functionalized epoxy/elastomer adduct is sold in admixture with an epoxy resin under the trade name HyPox™ RK84 ( FIG. 5 ), a bisphenol A epoxy resin modified with CTBN elastomer, and the trade name HyPox™ RA1340 ( FIG. 6 ), an epoxy phenol novolac resin modified with CTBN elastomer, both commercially available from CVC Thermoset Specialties, Moorestown, N.J. In addition to bisphenol A epoxy resins, other epoxy resins can be used to prepare the epoxy/elastomer adduct, such as n-butyl glycidyl ether, styrene oxide and phenylglycidyl ether; bifunctional epoxy compounds such as bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether and diglycidyl phthalate; trifunctional compounds such as triglycidyl isocyanurate, triglycidyl p-aminophenol; tetrafunctional compounds such as tetraglycidyl m-xylene diamine and tetraglycidyldiaminodiphenylmethane; and compounds having more functional groups such as cresol novolac polyglycidyl ether, phenol novolac polyglycidyl ether and so on. Examples of additional or alternative epoxy/elastomer and other adducts suitable for use in the present invention are disclosed in U.S. Pat. No. 6,846,559 and U.S. Patent Publication 2004/0204551 to Czaplicki, Michael both of which are incorporated herein by reference.
[0067] Amine Compound Plus Reactive Dispersant
[0068] To prepare the curing agent, in one non-limiting process, the selected amine compound and the epoxide-functionalized reactive dispersant are first allowed to react to ensure the dispersant is fully incorporated. The reactive dispersant is dissolved in a selected solvent system and allowed to react using a combination of heating and stirring from about 2 min to about 3 h, preferably from about 4 min to about 2 h, and most preferably from about 5 min to about 1 h. Thus, the reaction temperature which can be employed in the present invention is typically 40° C. to 90° C., preferably 50° C. to 80° C., and the concentration of the starting materials, i.e. the amine compound and the epoxide-functionalized reactive dispersant, is typically about 2 to 40% by weight, preferably about 5 to 30% by weight. The amount of reactive dispersant is from about 1 to 70% (w/w) based on the combined weights of the reactive dispersant and amine compound, preferably from about 5 to 50% (w/w) based on the combined weights of the reactive dispersant and amine compound and most preferably from about 9 to 35% (w/w) based on the combined weights of the reactive dispersant and amine compound. In the special case where the epoxide-functionalized reactive dispersant contains a residual epoxy compound that is not bonded to the elastomer, such as in FIGS. 5 and 6 , an additional purification step is undertaken which consists of removing the unreacted epoxy compound from said reactive dispersant. This purification step is especially important to avoid the formation of aggregates and lumps of solid material after the addition of the epoxy compound (see below).
[0069] Epoxy Compatible Material
[0070] The epoxy compatible material is any epoxy-functional material that contains a functional group or groups that are compatible with an epoxy resin. One example are the epoxide-functionalized epoxy/elastomer adducts that are sold as admixtures with an epoxy resin, available commercially under the trade name HyPox™ RK84 ( FIG. 5 ) and the trade name HyPox RA1340 ( FIG. 6 ), from CVC Thermoset Specialties, Moorestown, N.J. Said HyPox elastomers contain the epoxy compatibilizing monomer acrylonitrile. Other examples would include, but are not limited to, epoxy-functional polyacrylates that would contain epoxy compatible co-monomers, like acrylonitrile and methyl methacrylate.
[0071] Amine Compound Plus Epoxide-Functionalized Reactive Dispersant Plus Epoxy Compound, Formation of the Un-Encapsulated Particles.
[0072] After the amine compound has been allowed to react with the epoxide-functionalized dispersant, the formation of the un-encapsulated latent hardener particles begins with the addition of the epoxy compound. A solution of the epoxy compound is slowly added to the stirred heated solution of the amine compound-dispersion stabilizer solution over the course from about 5 min to 6 h, preferably from about 10 min to 4 h, and most preferably from about 15 min to 2 h, using an apparatus that allows for a constant uninterrupted addition of epoxy resin solution, such as a syringe pump or peristaltic pump or the like. The amount of epoxy compound is from about 10 to 90% (w/w) based on the combined weights of the amine compound, reactive dispersant, and epoxy compound, preferably from about 30 to 85% (w/w) based on the combined weights of the amine compound, reactive dispersant, and epoxy compound, and most preferably from about 50 to 80% (w/w) based on the combined weights of the amine compound, reactive dispersant, and epoxy compound. In one example, a solution of the reactive dispersant and the amine is agitated, while heating, under an inert atmosphere and after a predetermined time, a solution of epoxy compound is added over a predetermined time. The originally clear solution will become opaque as the epoxy compound begins to react. As the reaction progresses, the opaqueness of the reaction system gradually increases, with a characteristic milky white turbid dispersion eventually occurring.
[0073] When the reaction temperature and the concentration of the starting materials are too high, aggregates may easily form even in the presence of a suitable amount of the reactive dispersant. Thus, the reaction temperature which can be employed in the present invention is typically 40° C. to 90° C., preferably 50° C. to 80° C., and the concentration of the starting materials, i.e. the amine compound, the reactive dispersant, and epoxy compound, is typically 2 to 40% by weight, preferably 5 to 30% by weight. Generally, the particle size of the adduct increases with increased concentrations of the starting materials but decreases with increased concentrations of the reactive dispersant.
[0074] Encapsulation
[0075] The particles are subsequently encapsulated, with each layer of encapsulate or protective shell applied over the particle in two or more successive steps. Various known methods for encapsulating spherical curing agents may be used in this invention. In one embodiment, the adduct particles may be reacted with an encapsulation agent to form two or more protective shells, where said encapsulating agent is comprised of a polyfunctional isocyanate compound or a mixture of polyfunctional isocyanate compounds and multifunctional epoxy compounds or a mixture of polyfunctional isocyanate and epoxy compatible compound (e.g., acrylonitrile), or a mixture of a polyfunctional isocyanate, epoxy compounds, and epoxy compatible compound. Suitable polyfunctional isocyanate compounds include the mononuclear and polynuclear species of toluene diisocyanate, methylene diphenyl diisocyanate, hydrogenated methylene diphenyl diisocyanate, 1,5-naphthalene diisocyanate, isophorone diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, tetramethylxylene diisocyanate, 1,3,6-hexamethylene triisocyanate, lysine diisocyanate, triphenylethane triisocyanate, polyfunctional isocyanate compounds formed by addition of such compounds and other active hydrogen-containing compound, and any mixtures thereof.
[0076] Representative examples of multifunctional epoxies include methylene bisglycidyl aniline, HELOXY™ Modifier 48 (a product of Hexion Specialty Chemicals), Toagosei GP-301 graft polymethylmethacrylate-g-epoxy modified acrylate polymer, and a multi-functional epoxy containing acrylonitrile (epoxy compatible co-monomer) but other multifunctional epoxies should also work.
[0077] The amount of the encapsulation agent employed to encapsulate the un-encapsulated particles affects the storage stability and the curability of a curing agent masterbatch. With the same particles of the addition product, increased amounts of the encapsulation agent improve the storage stability, but lower the curability. Thus, for adduct particles having a diameter of about 0.1 micron to 30 micron, the encapsulation agent is employed in ratio from about 50:50 to 95:5 (w/w) core particles to encapsulation agent, preferably from about 60:40 to 90:10 (w/w) core particles to encapsulation agent, and most preferably in a ratio from about 70:30 to 90:10 (w/w) core particles to encapsulation agent. Additionally, when the encapsulation agent is a mixture of isocyanate compounds and epoxy compounds or isocyanate compounds and epoxy compatible compounds, the amount of epoxy compound is used in a ratio from about 1:99 to 99:1 (w/w) isocyanate compounds to epoxy compounds, preferably from about 60:40 to 99:1 (w/w) isocyanate compounds to epoxy compounds, and most preferably in a ratio from about 80:20 and 99:1 (w/w) isocyanate compounds to epoxy compounds. Additionally, when the encapsulation agent is a mixture of isocyanate compounds, epoxy compounds, and epoxy compatible compounds, the amount of epoxy compound is used in a ratio from about 1:99 to 99:1 (w/w) isocyanate compounds to epoxy compounds, preferably from about 60:40 to 99:1 (w/w) isocyanate compounds to epoxy compounds plus epoxy compatible compounds, and most preferably in a ratio from about 80:20 and 99:1 (w/w) isocyanate compounds to epoxy compounds. Thus, the compromise between storage stability and curability varies depending on the size of the adduct particle, with smaller particle sizes requiring increased amounts of shell forming material such as polyfunctional isocyanate to achieve the same release or barrier properties.
[0078] In one embodiment, when the particle forming reaction is completed, the un-encapsulated particles are isolated from the reaction medium by filtration and then washed with fresh solvent. The particles are then subsequently encapsulated.
[0079] Masterbatch
[0080] In general, to form the masterbatch, the encapsulated particles are uniformly dispersed in an epoxy resin in a range from about 5 to 90% (w/w) based on the combined weights of the particles and epoxy resin, preferably in the range of about 15 to 80% (w/w) based on the combined weights of the particles and liquid epoxy compound, and most preferably in the range of about 20 to 70% (w/w) based on the combined weights of the particles and liquid epoxy compound.
[0081] In one embodiment, the epoxy resin can be one or more epoxy resins of bisphenol A, bisphenol F, novolac epoxies, and the like.
[0082] In one embodiment, to avoid the formation of secondary particles, the encapsulated particles are mechanically dispersed in the epoxy resin as primary particles, for example, by blending with a three roll mill.
[0083] In another embodiment, after the encapsulation process is completed, heating and stirring are stopped and an epoxy resin is added to the dispersion. The mixture is again stirred, enough to distribute the epoxy resin equally in the dispersion. The solvent is then removed, using vacuum distillation, or the like, such that the total solid content is about 60 to 100% (w/w), preferably about 70 to 100% (w/w), and most preferably about 80 to 100% (w/w). The particles are then dispersed further in the epoxy resin using techniques known to those of ordinary skill in the art, such as a three-roll mill, or the like.
[0084] In yet another embodiment, when the reaction is completed, the solvent is removed using vacuum distillation to 100% (w/w) solids content. The solid particles are then added to an epoxy resin and the particles dispersed further in epoxy resin using techniques known to those of ordinary skill in the art, such as a three-roll mill, or the like.
[0085] In still yet another embodiment, when the reaction is completed, the particles are separated by filtering the dispersion of the particles. Fresh solvent is used to wash off unreacted starting material adhered to the surface of the particles. An epoxy resin is then added to the solid particles and the mixture dispersed further using techniques known to those of ordinary skill in the art, such as a three-roll mill, or the like.
[0086] The adhesive compositions disclosed herein are potentially useful in various applications including in a conducting adhesive, composite, molding compound, anisotropic conducting film (ACF) adhesive, non-random array ACF, non-conductive adhesive film (NCF), coating, encapsulant, underfill material, lead-free solder, etc.
[0087] Having described the invention in detail, the invention will be illustrated by the following non-limiting examples:
EXAMPLES
Examples for the Formation of the Un-Encapsulated Core Particles
Example 1
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (1)
[0088] Commercial material HyPox RK84 [a commercial material of CVC Thermoset Specialties and mixture of a bisphenol A epoxy resin and its adduct with CTBN ( FIG. 5 )] was used as the dispersion stabilizer. A three-necked round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet was charged with 0.93 g of the CTBN-epoxy adduct, 1.64 g (0.02 mole) of 2-methylimidazole and 48 g of 4-methyl-2-pentanone (MIBK). The reactor was placed in an 80° C. bath and purged with argon. After 1 h, a solution of 3.39 g (0.019 equivalent weight) DER™ 332 (a product of Dow Chemical) and 3.4 g of MIBK was added dropwise over the course of 20 min, after which the reaction was allowed to stir at 300 rpm for 6 hr under an argon atmosphere. A white milky dispersion was formed. The dispersion was discharged from the reactor, centrifuged, washed with MIBK, and evaporated to dryness to afford 3.6 g (60.4% yield) of product. A small drop of the dispersion was diluted, coated on glass slide and dried in vacuum at room temperature. The dried sample was sputtered with a thin layer of gold and the scanning electron micrograph of this taken using a Hitachi S-2460N scanning electron microscope.
Example 2
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (2)
[0089] A CTBN-epoxy adduct that was isolated from CVC Thermoset Specialties HyPox™ RK84 was used as the dispersion stabilizer. The adduct was obtained by dissolving the material in methyl ethyl ketone, followed by precipitation with methanol, and repeating the process two more times. The un-encapsulated core particles 2 were synthesized from 0.51 g of the CTBN-epoxy adduct, 1.63 g (0.02 mole) of 2-methylimidazole, 3.51 g (0.02 equivalent weight) DER™ 332 and 51 g of MIBK using the procedure of Example 1 to afford 4.4 g (78% yield) of particles.
Example 3
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RA 1340 (3)
[0090] Commercial material HyPox RA1340 [a commercial material of CVC Thermoset Specialties and mixture of diglycidyl ether of bisphenol A and its adduct with CTBN ( FIG. 6 )] was used as the dispersion stabilizer. The microcapsule core 3 was synthesized from 1.15 g of the aforementioned CTBN-epoxy adduct, 1.64 g (0.02 mole) of 2-methylimidazole, 2.87 g (0.0164 equivalent weight) DER™ 332 and 51 g of MIBK using the procedure of Example 1 to afford 1.2 g (21.2% yield) of particles.
Example 4
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RA 1340 (4)
[0091] A CTBN-epoxy adduct isolated from CVC Thermoset Specialties HyPox™ RA 1340 was used as the dispersion stabilizer. The adduct was obtained by first dissolving the material in methyl ethyl ketone, followed by precipitation with methanol, and repeating the process two more times. The un-encapsulated core particles 4 were synthesized from 0.53 g of the CTBN-adduct, 1.65 g (0.02 mole) of 2-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, and 51 g of MIBK using the procedure as described in Example 1 to afford 2.6 g (45.9% yield) of particles.
Example 5
Synthesis of Un-Encapsulated Core Particles from 2-ethyl-4-methylimidazole, DGEBA, and HyPox™ RK 84 (5)
[0092] The un-encapsulated core particles 5 were synthesized from 0.57 g of the CTBN-epoxy adduct of Example 2, 2.20 g (0.02 mole) of 2-ethyl-4-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, and 63 g of MIBK using the procedure of Example 1 to afford 0.7 g (11.2% yield) of particles.
Example 6
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RA 1340 (6)
[0093] The un-encapsulated core particles 6 were synthesized from 0.26 g of the CTBN-epoxy adduct of Example 4, 1.64 g (0.02 mole) of 2-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, and 50 g of MIBK using the procedure of Example 1 to afford 1.6 g (26.9% yield) of particles.
Example 7
Synthesis of Un-Encapsulated Core Particles from 2-ethyl-4-methylimidazole, DGEBA, and HyPox™ RK 84 (7)
[0094] The un-encapsulated core particles 7 were synthesized from 0.57 g of the CTBN-epoxy adduct of Example 2, 2.20 g (0.02 mole) of 2-ethyl-4-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332 and 56 g of MIBK using the procedure of Example 1 and the reaction was allowed to stir at 300 rpm for 16.5 h under an argon atmosphere to afford 2.5 g (40% yield) of particles.
Example 8
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (8)
[0095] The microcapsule core 8 was synthesized from 0.52 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, and 51 g of MIBK using the procedure of Example 1. The reaction was allowed to stir at 300 rpm for 16 h under an argon atmosphere to afford 4.0 g (71% yield) of particles.
Example 9
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (9)
[0096] The un-encapsulated core particles 9 were synthesized from 0.52 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, and 52 g of MIBK using the procedure of Example 1. The reaction was allowed to stir at 1000 rpm for 6 h under an argon atmosphere to afford 4.18 g (74% yield) of particles.
Example 10
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (10)
[0097] The un-encapsulated core particles 10 were synthesized from 0.52 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole and 37.3 g of 4-methyl-2-pentanone (MIBK). The reactor was placed in an 80° C. bath and purged with argon. After 1 h, a solution of 3.5 g (0.02 equivalent weight) DER™ 332 (a product of Dow Chemical) and 3.5 g of MIBK was added dropwise over the course of 15 min, after which the reaction was allowed to stir at 1000 rpm for 1 h under an argon atmosphere. After this, 10 g of heptane was added dropwise over the course of 1 h. The reaction was allowed to stir at 1000 rpm for another 4 h. A white milky dispersion was formed. The dispersion was discharged, centrifuged, washed with MIBK, and evaporated to dryness to afford 2.1 g (37% yield) of dried particles.
Example 11
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (11)
[0098] The un-encapsulated core particles 11 were synthesized from 0.52 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, and 37.3 g of 4-methyl-2-pentanone (MIBK). The reactor was placed in an 80° C. bath and purged with argon. After 1 h, a solution of 3.5 g (0.02 equivalent weight) DER™ 332 (a product of Dow Chemical) and 3.5 g of MIBK was added dropwise over the course of 15 min, after which the reaction was allowed to stir at 1000 rpm for 1 h under an argon atmosphere, after which 3 g of heptane was added drop wise over the course of 1 h. The reaction was allowed to stir at 1000 rpm for 4 h. A white milky dispersion was formed. The dispersion was discharged, centrifuged, washed with MIBK, and evaporated to dryness to afford 3.0 g (53% yield) of dried particles.
Example 12
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (12)
[0099] The un-encapsulated core particles 12 were synthesized from 1.05 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, and 51 g of MIBK using the procedure of Example 1. The reaction was allowed to stir at 1000 rpm for 6 h to afford 4.4 g (71% yield) of particles.
Example 13
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (13)
[0100] A three-necked round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet. The flask was charged with 0.52 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 5.1 g of heptane and 42.3 g of 4-methyl-2-pentanone (MIBK). The reaction flask was placed in an 80° C. bath and purged with argon. After 1 h, a solution of 3.5 g (0.02 equivalent weight) DER™ 332 (a product of Dow Chemical) and 3.6 g of MIBK was added dropwise over the course of 15 min, after which the reaction was allowed to stir at 1000 rpm for 6 h. A white milky dispersion was formed. The dispersion was discharged, centrifuged, washed with MIBK, and evaporated to dryness to afford 3.4 g (60% yield) of particles.
Example 14
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and “Purified” HyPox™ RK 84 (14)
[0101] A three-necked round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet was charged with 0.52 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 5.1 g of heptane and 46.8 g of 4-methyl-2-pentanone (MIBK). The reactor was placed in an 80° C. bath and purged with argon and stirred for 1 h at 300 rpm. A solution of 3.5 g (0.02 equivalent weight) DER™ 332 (a product of Dow Chemical) and 3.5 g of MIBK was added dropwise over the course of 15 min, after which the reaction was allowed to stir at 300 rpm for 1 hr and then at 1000 rpm for another 5 h. A white milky dispersion was formed. The dispersion was discharged, centrifuged, washed with MIBK and evaporated to dryness to afford 3.2 g (57% yield) of particles.
Example 15
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (15)
[0102] The un-encapsulated core particles (15) were synthesized from 0.51 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, 15.3 g of heptane and 34 g of MIBK using the procedure of Example 13. The reaction was allowed to stir at 1000 rpm for 6 h under an argon atmosphere to afford 4.5 g (80% yield) of particles.
Example 16
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (16)
[0103] The un-encapsulated core particles 16 were synthesized from 0.52 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, 2.6 g of heptane and 49 g of MIBK using the procedure of Example 13 and the reaction was allowed to stir at 1000 rpm for 6 h under an argon atmosphere to afford 2.4 g (42.4% yield) of particles.
Example 17
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (17)
[0104] The un-encapsulated core particles 17 were synthesized from 0.52 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, 10.2 g of heptane and 41 g of MIBK using the procedure of Example 13. The reaction was allowed to stir at 1000 rpm for 6 h under an argon atmosphere to afford 3.9 g (69% yield) of particles.
Example 18
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (18)
[0105] A three-necked round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet was charged with 0.52 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, and 47.3 g of 4-methyl-2-pentanone (MIBK). The reactor was placed in an 80° C. bath, and purged with argon. After the reaction was allowed to stir at 300 rpm for 1 hr, a solution of 3.5 g (0.02 equivalent weight) DER™ 332 (a product of Dow Chemical) and 3.5 g of MIBK was added dropwise over the course of 15 min, after which the reaction was allowed to stir at 300 rpm for 1 h and then 1000 rpm for another 5 h. A white milky dispersion was formed. The dispersion was discharged, centrifuged, washed with MIBK, and evaporated to dryness to afford 4.53 g (80% yield) of particles.
Example 19
Synthesis Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (19)
[0106] The un-encapsulated core particles 19 were synthesized from 0.51 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, and 51 g of MIBK using the procedure of Example 13 and the reaction was allowed to stir at 1500 rpm for 6 h under an argon atmosphere to afford 4.05 g (71.5% yield) of particles.
Example 20
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (20)
[0107] The un-encapsulated core particles 20 were synthesized from 0.52 g of the CTBN-epoxy adduct of Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, 7.6 g of heptane, and 43 g of MIBK using the procedure of Example 13 and the reaction was allowed to stir at 1000 rpm for 6 h to afford 4.05 g (71.5% yield) of particles.
Example 21
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (21)
[0108] The un-encapsulated core particles 21 were synthesized from 0.51 g of the CTBN-epoxy adduct from Example 2, 1.65 g (0.02 mole) of 2-methylimidazole, 3.5 g (0.02 equivalent weight) DER™ 332, 7.6 g of heptane and 43 g of MIBK using the procedure of Example 13. The reaction was allowed to stir at 1000 rpm for 16 h to afford 3.6 g (64% yield) of particles.
Example 22
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (22)
[0109] The un-encapsulated core particles 22 were synthesized from 0.51 g of the CTBN-epoxy adduct from Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.85 g (0.022 equivalent weight) DER™ 332, 7.6 g of heptane, and 43 g of MIBK using the procedure of Example 13. The reaction was allowed to stir at 1000 rpm for 6 h under an argon atmosphere to afford 4.95 g (82.3% yield) of particles. A small drop of the dispersion was diluted with MIBK, coated on glass slide, and dried under vacuum at room temperature. The dried sample was sputtered with a thin layer of gold and its electron micrograph ( FIG. 1 and FIG. 2 ) taken with a Hitachi S-2460N scanning electron microscope.
Example 23
Synthesis of Un-Encapsulated Core Particles from 2-methylimidazole, DGEBA, and HyPox™ RK 84 (23)
[0110] The un-encapsulated core particles 23 were synthesized from 0.51 g of the CTBN-epoxy adduct from Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.85 g (0.022 equivalent weight) DER™ 332, 7.6 g of heptane and 42 g of MIBK using the procedure of Example 13. The reaction was allowed to stir at 1000 rpm for 16 h to afford 4.49 g (74.7% yield) of particles.
Examples for the Encapsulation of the Un-Encapsulated Core Particles
Example 24
Encapsulated Particles from 2-methylimidazole, DGEBA, HyPox™ RK 84, and MDI (24)
[0111] The microcapsule core was synthesized from 0.52 g of the CTBN-epoxy adduct from Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.85 g (0.022 equivalent weight) DER™ 332, 7.6 g of heptane and 42 g of MIBK using the procedure of Example 13. The reaction was allowed to stir at 1000 rpm for 6 h under an argon atmosphere. A small drop of the dispersion was removed, diluted with MIBK, coated on glass slide, and dried under vacuum at room temperature. The dried sample was sputter-coated with a thin layer of gold and the electron micrograph taken with a Hitachi S-2460N scanning electron microscope. The encapsulation was started by adding a solution of 1.56 g (0.0125 equivalent weight) of 4,4′-Methylenebis(phenyl isocyanate), most commonly referred to as MDI, and 14.1 g of MIBK, which was added dropwise over the course of 110 min, after which the reaction was allowed to stir at 1000 rpm for 15 h under an argon atmosphere. A small drop of the dispersion was dried and its FT-IR spectrum showed complete conversion of the isocyanate moiety. After it was confirmed all of the isocyanate had been consumed, a small drop of the dispersion was removed, diluted with additional MIBK, coated on glass slide, and dried under vacuum at room temperature. The dried sample was sputtered with a thin layer of gold and its electron micrograph taken with a Hitachi S-2460N scanning electron microscope ( FIG. 3 and FIG. 4 ).
Example 25
Synthesis Microcapsules from 2-methylimidazole, DGEBA, HyPox™ RK 84, MDI, and 4,4′-Methylenebis(N,N-diglycidylaniline) (25)
[0112] The microcapsule core was synthesized from 0.51 g of the CTBN-epoxy adduct from Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.85 g (0.022 equivalent weight) DER™ 332, 7.6 g of heptane and 42 g of MIBK using the procedure of Example 13 and the reaction was allowed to stir at 1000 rpm for 6 hr under an argon atmosphere. The encapsulation was started by adding a solution of 1.4 g (0.0112 equivalent weight) of MDI, 0.16 g (0.00038 equivalent weight) of 4,4′-Methylenebis(N,N-diglycidylaniline), and 14.1 g of MIBK, which was added dropwise over the course of 110 min, after which the reaction was allowed to stir at 1000 rpm for 15 h under an argon atmosphere. A small drop of dispersion was dried and its FT-IR spectrum showed complete conversion of the isocyanate moiety.
Example 26
Synthesis of Microcapsules from 2-methylimidazole, DGEBA, HyPox™ RK 84, and MDI (26)
[0113] The microcapsule core was synthesized from 0.52 g of the CTBN-epoxy adduct from Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.86 g (0.022 equivalent weight) DER™ 332, 7.6 g of heptane, and 42 g of MIBK using the procedure of Example 13. The reaction was allowed to stir at 1000 rpm for 6 h under an argon atmosphere. The encapsulation was performed by the addition of a solution of 1.57 g (0.0125 equivalent weight) of MDI and 14.1 g of MIBK, which was added dropwise over the course of 90 min, after which the reaction was allowed to stir at 1000 rpm for 15 h under an argon atmosphere. A small drop of dispersion was dried and its FT-IR spectrum showed complete conversion of the isocyanate moiety.
Example 27
Synthesis of Microcapsules from 2-methylimidazole, DGEBA, HyPox™ RK 84, MDI, and 4,4′-Methylenebis(N,N-diglycidylaniline) (27)
[0114] The microcapsule core was synthesized from 0.52 g of the CTBN-epoxy adduct from Example 2, 1.64 g (0.02 mole) of 2-methylimidazole, 3.85 g (0.022 equivalent weight) DER™ 332, 7.6 g of heptane and 43 g of MIBK using the procedure of Example 13 and the reaction was allowed to stir at 1000 rpm for 6 hr under an argon atmosphere. The encapsulation was started by adding a solution of 2.8 g (0.0223 equivalent weight) of MDI (a product of Sigma Aldrich), 0.35 g (0.0033 equivalent weight) of 4,4′-Methylenebis(N,N-diglycidylaniline), and 14.1 g of MIBK, which was added dropwise over the course of 240 min, after which the reaction was allowed to stir at 1000 rpm for 15 h under an argon atmosphere.
Example 28
Synthesis of Microcapsules from 2-methylimidazole, DGEBA, HyPox™ RK 84, MDI, and 4,4′-Methylenebis(N,N-diglycidylaniline) (28)
[0115] A three-necked round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet was charged with 1.03 g of the CTBN-epoxy adduct from Example 2, 3.28 g (0.04 mole) of 2-methylimidazole, 15.2 g of heptane and 76 g of 4-methyl-2-pentanone (MIBK). The reactor was placed in an 80° C. bath and purged with argon. After 1 hr, a solution of 7.7 g (0.044 equivalent weight) DER™ 332 (a product of Dow Chemical) and 7.7 g of MIBK was added drop wise over the course of 40 min, after which the reaction was allowed to stir at 1000 rpm for 6 hr under an argon atmosphere. A white milky dispersion was formed. A small drop of the dispersion was diluted, coated on glass slide and dried in vacuum oven at room temperature. The dried sample was sputtered with a thin layer of Au and taken scanning electron micrographs. The encapsulation was started by adding a solution of 2.8 g (0.0223 equivalent weight) of MDI, 0.32 g (0.003 equivalent weight) of 4,4′-Methylenebis(N,N-diglycidylaniline), and 28.2 g of MIBK, which was added dropwise over the course of 240 min, after which the reaction was allowed to stir at 1000 rpm for 12.5 hr under an argon atmosphere.
Example 29
Synthesis of Microcapsules from 2-methylimidazole, DGEBA, HyPox™ RK 84L, Desmodur® W, and 4,4′-Methylenebis(N,N-diglycidylaniline) (29)
[0116] A three-necked round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet was charged with 2.09 g of the CTBN-epoxy adduct from Example 2, 6.56 g (0.08 mole) of 2-methylimidazole and 183 g of 4-methyl-2-pentanone (MIBK). The reactor was placed in an 80° C. bath and purged with argon. After 1 hr, a solution of 15.4 g (0.088 equivalent weight) DER™ 332 (diglycidyl ether of bisphenol A (DGEBA) from Dow Chemical) and 18.7 g of MIBK was added drop wise over the course of 1 hr, after which the reaction was allowed to stir at 1000 rpm for 6 hr under an argon atmosphere. A white milky dispersion was formed. The particles were allowed to precipitate under gravity allowing the supernatant liquid was removed by decantation. The particles were redispersed in MIBK. The residual dispersion was filtered through a small pore size membrane filter. The particles were redispersed in MIBK and then filtered through a 30 μm pore size filter to remove large-sized particles and aggregates. A few drops of the resulting dispersion were dried, sputtered with gold, loaded into an SEM. Its micrograph showed the particles were of adequate quality to be allowed to proceed on to the encapsulation step. The solid content of the dispersion was measured at 9.84% (w/w). The yield of total dispersion was 84.4 g.
[0117] A three-neck round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet was charged with 0.83 g of the CTBN-epoxy adduct from Example 2, 10.3 g of MIBK, and the purified dispersion. The reactor was placed in an 80° C. bath and purged with argon. To this, 17 g of heptane was added drop-wise over the course of 1 hr. The encapsulation was started by adding a solution of 1.9 g (0.0145 equivalent weight) of Desmodur® W (a liquid cycloaliphatic diisocyanate from Bayer MaterialScience), 0.19 g (0.002 equivalent weight) of 4,4′-Methylenebis(N,N-diglycidylaniline), and 18.9 g of MIBK, which was added drop-wise over the course of 4 hr, after which the reaction was allowed to stir at 1000 rpm for 12.5 hr under an argon atmosphere.
Example 30 (Prophetic)
Synthesis of Microcapsules Comprised of Two Shell Materials
[0118] A three-necked round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet is charged with 2.09 g of the CTBN-epoxy adduct from Example 2, 6.56 g (0.08 mole) of 2-methylimidazole and 183 g of 4-methyl-2-pentanone (MIBK). The reactor is placed in an 80° C. bath and purged with argon. After 1 hr, a solution of 15.4 g (0.088 equivalent weight) DER™ 332 (a product of Dow Chemical) and 18.7 g of MIBK is added drop-wise over the course of 1 hr, after which the reaction is allowed to stir at 1000 rpm for 6 hr under an argon atmosphere. A white milky dispersion is formed. The particles are allowed to precipitate under gravity allowing the supernatant liquid to be removed by decantation. The particles are redispersed in MIBK. The residual dispersion is filtered through a small pore size membrane filter. The particles are redispersed in MIBK and then filtered through a 30 μm pore size filter to remove large-sized particles and aggregates.
[0119] A three-neck round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet is charged with 0.83 g of the CTBN-epoxy adduct from Example 2, 10.3 g of MIBK, and the purified dispersion. The reactor is placed in an 80° C. bath and purged with argon. To this, 17 g of heptane is added drop-wise over the course of 1 hr. The encapsulation with the first shell layer was started by adding a solution of 1.9 g (0.0145 equivalent weight) of Desmodur® W (a product of Bayer MaterialScience), 0.19 g (0.002 equivalent weight) of 4,4′-Methylenebis(N,N-diglycidylaniline), and 18.9 g of MIBK is added drop-wise over the course of 4 hr, after which the reaction is allowed to stir at 1000 rpm for 12.5 hr under an argon atmosphere.
[0120] The second shell layer is formed by the addition of a solution of 1.9 g (0.0145 equivalent weight) of Desmodur® W (a product of Bayer MaterialScience), 0.19 g (0.002 equivalent weight) of 4,4′-Methylenebis(N,N-diglycidylaniline), and 18.9 g of MIBK is added drop-wise over the course of 4 hr, after which the reaction is allowed to stir at 1000 rpm for 12.5 hr under an argon atmosphere.
Example 31 (Prophetic)
Synthesis of Microcapsules Comprised of Two Shell Materials, where the Outermost Shell Material is Comprised of an Epoxy Compatible Material
[0121] A three-necked round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet is charged with 2.09 g of the CTBN-epoxy adduct from Example 2, 6.56 g (0.08 mole) of 2-methylimidazole and 183 g of 4-methyl-2-pentanone (MIBK). The reactor is placed in an 80° C. bath and purged with argon. After 1 hr, a solution of 15.4 g (0.088 equivalent weight) DER™ 332 (a product of Dow Chemical) and 18.7 g of MIBK is added drop-wise over the course of 1 hr, after which the reaction is allowed to stir at 1000 rpm for 6 hr under an argon atmosphere. A white milky dispersion is formed. The particles are allowed to precipitate under gravity allowing the supernatant liquid to be removed by decantation. The particles are redispersed in MIBK. The residual dispersion is filtered through a small pore size membrane filter. The particles are redispersed in MIBK and then filtered through a 30 μm pore size filter to remove large-sized particles and aggregates.
[0122] A three-neck round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet is charged with 0.83 g of the CTBN-epoxy adduct from Example 2, 10.3 g of MIBK, and the purified dispersion. The reactor is placed in an 80° C. bath and purged with argon. To this, 17 g of heptane is added drop-wise over the course of 1 hr. The first shell layer encapsulation was started by adding a solution of 1.9 g (0.0145 equivalent weight) of Desmodur® W (a product of Bayer MaterialScience), 0.19 g (0.002 equivalent weight) of 4,4′-Methylenebis(N,N-diglycidylaniline), and 18.9 g of MIBK is added drop-wise over the course of 4 hr, after which the reaction is allowed to stir at 1000 rpm for 12.5 hr under an argon atmosphere.
[0123] The second shell layer is formed by the addition of a solution of 1.9 g (0.0145 equivalent weight) of Desmodur® W (a product of Bayer MaterialScience), 1.9 g of CVC Thermoset Materials HyPox™ RA1340, and 18.9 g of MIBK is added drop-wise over the course of 4 hr, after which the reaction is allowed to stir at 1000 rpm for 12.5 hr under an argon atmosphere.
Example 32 (Prophetic)
Synthesis of Microcapsules Comprised of Two Shell Materials, where the Outermost Shell Material is Comprised of an Epoxy Compatible Material
[0124] A three-necked round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet is charged with 2.09 g of the CTBN-epoxy adduct from Example 2, 6.56 g (0.08 mole) of 2-methylimidazole and 183 g of 4-methyl-2-pentanone (MIBK). The reactor is placed in an 80° C. bath and purged with argon. After 1 hr, a solution of 15.4 g (0.088 equivalent weight) DER™ 332 (a product of Dow Chemical) and 18.7 g of MIBK is added drop-wise over the course of 1 hr, after which the reaction is allowed to stir at 1000 rpm for 6 hr under an argon atmosphere. A white milky dispersion is formed. The particles are allowed to precipitate under gravity allowing the supernatant liquid to be removed by decantation. The particles are redispersed in MIBK. The residual dispersion is filtered through a small pore size membrane filter. The particles are redispersed in MIBK and then filtered through a 30 μm pore size filter to remove large-sized particles and aggregates.
[0125] A three-neck round bottom flask, equipped with a PTFE fluoropolymer half moon-shaped overhead stirrer, a reflux condenser, an addition funnel, and an argon gas inlet is charged with 0.83 g of the CTBN-epoxy adduct from Example 2, 10.3 g of MIBK, and the purified dispersion. The reactor is placed in an 80° C. bath and purged with argon. To this, 17 g of heptane is added drop-wise over the course of 1 hr. The encapsulation was started by adding a solution of 1.9 g (0.0145 equivalent weight) of Desmodur® W (a product of Bayer MaterialScience), 0.19 g (0.002 equivalent weight) of 4,4′-Methylenebis(N,N-diglycidylaniline), and 18.9 g of MIBK is added drop-wise over the course of 4 hr, after which the reaction is allowed to stir at 1000 rpm for 12.5 hr under an argon atmosphere.
[0126] The second shell layer is formed by the addition of a solution of 1.9 g (0.0145 equivalent weight) of Desmodur® W (a product of Bayer MaterialScience), 1.9 g of Toagosei GP-301 graft polyacrylate, 0.19 g (0.002 equivalent weight) of 4,4′-Methylenebis(N,N-diglycidylaniline), and 18.9 g of MIBK is added drop-wise over the course of 4 hr, after which the reaction is allowed to stir at 1000 rpm for 12.5 hr under an argon atmosphere.
Examples for the Preparation of the Masterbatch
Example 33
Preparation of the Masterbatch from the Particles of Example 24
[0127] The dispersion of the particles of Example 24 were evaporated under vacuum at 50° C. to obtain a yellow solid, ground with a mortar and pestle, and added to diglycidyl ether of bisphenol A in a ratio of 35:65 (w/w) particles to epoxy resin. The mixture was dispersed for 20 min using a three roll mill to obtain a creamy yellow dispersion.
Example 34
Preparation of the Masterbatch from the Particles of Example 28
[0128] At room temperature, 10 g of diglycidyl ether of bisphenol A was added to the reaction mixture of Example 28, which contained the dispersion of the particles, and stirred for 3 hr. The solvent was removed under vacuum at 31° C. to a solids content of 86% (w/w). From this, 12.86 g was removed and mixed with and additional 7.90 g of diglycidyl ether of bisphenol A. The mixture was then process further for 3 min using a three-roll mill to obtain a creamy yellow dispersion.
[0129] Performance Results:
[0130] For the solvent resistance test, mixtures were prepared by combining the particles, diglycidyl ether of bisphenol A, and MIBK in a ratio of 4:50:46 (w/w). The mixtures were then placed in a 40° C. oil bath and monitored visually for a change in viscosity. The results are shown below in Table 1. Aliquots of the mixtures above were coated on glass slides as thin films and dried under vacuum at room temperature. DSC traces were obtained using a TA Instruments Q10 Differential Scanning calorimeter using a temperature window of 30 to 250° C., a heating rate of 5° C./min, and performed under a nitrogen atmosphere. The results are shown below in Table 1.
[0000]
TABLE 1
The solvent resistance and DSC results of the un-encapsulated and
encapsulated particles:
Solvent resistance and DSC results of the un-encapsulated and
encapsulated particles
Un-
Solvent
DSC
encapsulated/
resistance
T peak (exo,
Particle
Encapsulated
Time to gel (h)
° C.)
ΔH (J/g)
22
Un-encapsulated
14
105
297
24
Encapsulated
120
119
330
25
Encapsulated
170
124
307
27
Encapsulated
240
142
200
28
Encapsulated
190
124
218
[0131] Having described the invention in detail and by reference to specific embodiments thereof it will be apparent to those skilled in the art that numerous variations and modifications are possible without departing from the spirit and scope of the following claims. | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is based on and hereby claims priority to PCT Application No. PCT/GB2007/050660 filed on Oct. 30, 2007, GB Application No. 0621598.2 filed on Oct. 31, 2006 and GB Application No. 0720885.3 filed on Oct. 25, 2007, the contents of which are hereby incorporated by reference.
BACKGROUND
[0002] This invention relates to a method of downlink operation in a communication system.
[0003] In Release 6 universal mobile telecommunications system (UMTS) terrestrial radio access network (UTRAN) frequency division duplex (FDD) systems a terminal can be in one of two states in the downlink, cell forward access channel (Cell_FACH) or cell dedicated channel (Cell_DCH). In Cell_FACH, there is no active connection to the Node B at the physical layer, no regular power control, or uplink. In Cell_DCH, there is continuous power control and active uplink and downlink. However, it is not desirable to keep the terminal in Cell_DCH state, as this uses up resources, so it is usual to move the terminal to another state when not actually communicating. Although it is not generally efficient to do so, the Cell_FACH state can be used for transmissions of small amounts of data. There are discussions to increase throughput and reduce latency requirements for users in Cell_FACH state by enabling the NodeB to map the data of the forward access channel (FACH) on high speed physical downlink shared channel (HS-PDSCH).
[0004] One proposal under discussion in 3 rd generation partnership project (3GPP) is that the high speed downlink shared channel (HS-DSCH) be used for carrying the FACH for users in CELL_FACH state, rather than using the secondary common control physical channel (S-CCPCH). This proposal is based on the assumption that the HS-DSCH would be transmitted on several consecutive occasions to the terminal, or user equipment (UE) to overcome the problems of feedback free operation and ensure correct reception at the same time. The high speed shared control channel (HS-SCCH) is required to indicate the start of the HS-DSCH transmission. Although consecutive transmission has advantages concerning latency, overcoming the problems due to different knowledge states in different involved entities, when comparing high speed downlink packet access (HSPDA) transmission versus S-CCPCH transmission as currently used as a physical channel for carrying the FACH, is not considered here.
[0005] Conventionally, the S-CCPCH, under control of the radio network controller (RNC) and the NodeB, the NodeB being used as transmitter only, has been used to carry the FACH and so the mobility procedures were controlled by the RNC. To enable inter-frequency and inter-radio access technology (RAT) measurements, FACH measurement occasions were assigned to different UEs, depending on a modulo cell radio network temporary identifier (C-RNTI) operation. In Cell-FACH state, a UE is requested to listen continuously whether it is scheduled, or not. For inter-frequency or inter-RAT measurements the UE needs to listen to other frequencies, so the FACH measurement occasions were introduced. The other measurements for handover are done based on the UE's internal identifier and when the RNC recognises this, the UE is switched to another frequency to do its measurements. However, the Node B has no knowledge of the measurement occasions as the Node B schedules as directed by the RNC. If the Node B is scheduling on HS-DSCH without knowing the measurement occasions, the Node B may try scheduling when the UE is on another frequency. This can give rise to loss of repeat transmissions due to the length of time that the UE is off the scheduling frequency.
SUMMARY
[0006] The inventors propose a method of downlink operation in a communication system comprising a network controller, a base station and a terminal. According to the method, one communication channel is scheduled by the base station; and one communication channel is scheduled by the network controller; wherein the terminal listens to the channel scheduled by the base station at predetermined times known to the terminal and the network controller; further comprises signalling from the network controller to the base station, information relating to the predetermined times.
[0007] Preferably, the communication system is in a state where there is no active communication between the terminal and the base station.
[0008] Preferably, the channel scheduled by the network controller has a longer transmit time interval than the channel scheduled by the base station.
[0009] Preferably, the downlink is high speed downlink packet access (HSDPA).
[0010] Preferably, the state is cell forward access channel (Cell_FACH) state.
[0011] Preferably, the network controller is a radio network controller.
[0012] Preferably, the base station is a Node B.
[0013] Preferably, the predetermined times are measurement occasions of the terminal.
[0014] Preferably, FACH content is mapped onto a high speed physical downlink shared channel (HS-PDSCH), or onto a high speed downlink shared channel (HS-DSCH).
[0015] Preferably, the signalling includes information on a relationship of secondary common control physical channel (S-CCPCH) transmit time interval (TTI) length and measurement occasion.
[0016] Preferably, the terminal has two operating states, one of which includes occasions at which the terminal retunes; and wherein the timing of the occasions is signalled from the network controller to the base station.
[0017] Preferably, the S-CCPCH having the smallest TTI length provided by the network is a reference for calculating length of a measurement occasion.
[0018] Preferably, the S-CCPCH using the left most or right most code of an orthogonal variable spreading factor (OVSF) code tree is a reference for calculating length of a measurement occasion.
[0019] Preferably, the signalling includes the cell radio network temporary identifier.
[0020] Preferably, without further signalling, a quick repeat transmission is resumed with its existing setting directly after termination of a measurement occasion, if an original repeat transmission was interrupted by the measurement occasion.
[0021] Preferably, the terminal can choose not to receive the resumed transmission, if the interrupted original repeat transmission was sufficient.
[0022] The inventors also propose a communication system operating in downlink. The communication system includes a base station, a base station controller and at least one terminal; wherein the terminal has two operating states in downlink; wherein in one operating state the terminal retunes its receiver to take measurements; and wherein times at which the retuning takes place are signalled from the base station controller to the base station.
[0023] Preferably, the base station controller further comprises a store to store rules which have been defined to determine timing of a next retransmission after a collision between a retuning to take measurements and a retransmission.
[0024] Preferably, the base station controller further comprises a processor, for processing an identifier of the terminal and determining timing of the retuning to take measurements from the identifier.
[0025] Preferably, the system operates high speed downlink packet access in Cell_FACH state.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] These and other objects and advantages of the present invention will become more apparent and more readily appreciated from the following description of the preferred embodiments, taken in conjunction with the accompanying drawings of which:
[0027] FIG. 1 illustrates signalling in different channels;
[0028] FIG. 2 is a block diagram of an example of a typical system for implementing the proposed method;
[0029] FIG. 3 illustrates message exchange in the system of FIG. 2 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0030] Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout.
[0031] The inventors' proposals address the problem of the base station trying to schedule the terminal during measurement occasions by providing information to the base station about the measurement occasions.
[0032] Technical specification TS25.331 defines the measurement occasion as follows:
When in CELL_FACH state and when the variable C_RNTI is non-empty the UE in FDD mode shall perform measurements as specified in subclauses 8.4.1.6 and 8.4.1.9 during the frame(s) with the cell system frame number (SFN) value fulfilling the following equation:
[0000] SFN div N=C — RNTI mod M _REP+ n*M _REP
[0000] where
N is the transmission time interval (TTI), in number of 10 ms frames, of the FACH having the largest TTI on the S-CCPCH selected by the UE according to the procedure in subclause 8.5.19. FACHs that only carry multimedia broadcast multicast service (MBMS) logical channels (MBMS traffic channel (MTCH), MBMS point to multipoint scheduling channel (MSCH), or MBMS point to multipoint control channel (MCCH)) are excluded from measurement occasion calculations. C_RNTI is the C-RNTI value of the UE stored in the variable C_RNTI M_REP is the Measurement Occasion cycle length. According to the equation above, a FACH Measurement Occasion of N frames will be repeated every N*M_REP frame, and M_REP=2 k .
where,
k is the FACH Measurement occasion cycle length coefficient.
The value of the FACH Measurement occasion cycle length coefficient is read in system information in “System Information Block type 11” or “System Information Block type 12” in the information element (1E) “FACH measurement occasion info”.
n=0, 1, 2 . . . as long as the SFN is below its maximum value
The UE is allowed to measure on other occasions in case the UE moves “out of service” area, or in case it can simultaneously perform the ordered measurements.
[0039] This means that the UE measurement behaviour depends on the TTI length of the used S-CCPCH to carry the FACH and is multiplied by 2̂K which describes the measurement occasion cycle length. Which of these 2̂K TTIs the Ue performs its measurements in, depends on the modulo C-RNTI operation. By these functions it is ensured that in case of a sufficient number of UEs within Cell-FACH, the times when UEs perform their measurements are nearly evenly distributed and there are always sufficient UEs to listen to the S-CCPCH. However, knowledge of the C-RNTI and the measurement occasions itself is present in the RNC and in the UE. Up to now, the NodeB has no knowledge of the measurement occasions as it schedules the UE as indicated by the RNC and so no knowledge is needed.
[0040] FIG. 1 illustrates a comparison of FACH scheduling via S-CCPCH against FACH scheduling via HS-DSCH, including HS-SCCH indication. A first signalling block 1 is sent on the HS-SCCH, then moves to the HS-PDSCH and is repeated 2 several times. Considering the offset between HS-SCCH and HS-DSCH it is clear that a 5 times quick repeat would not even work within a 10 ms S-CCPCH TTI 3 , which is the most commonly used TTI for S-CCPCH, even if a schedule “now” command for HSDPA were used. The UE may miss either the scheduling information, or the last transmissions, as the NodeB is not aware of the periods the UE is listening, nor would any scheduling method introducing more diversity than consecutive scheduling work.
[0041] To overcome the above mentioned problems it is important that the NodeB has awareness of the measurement behaviour of the UE. As a consequence, corresponding signalling from the RNC to the NodeB needs to be introduced as the NodeB has no UE context and in Cell-FACH there is no such context at all. However, by providing the C-RNTI and the calculation rule for the measuring occasions, the NodeB is able to calculate the times when the UE is listening and when the UE is measuring autonomously. In addition, if the FACH content is mapped to the HS-PDSCH only, then there needs to be clarification of which S-CCPCH TTI length drives the measurement occasion length used in the FACH calculation. Although, an S-CCPCH exists carrying FACH data for non-HSDPA UEs, the NodeB is not aware of this and there may also be multiple S-CCPCHs with different TTI length. For example, MTCH is also mapped to the S-CCPCH having a very large TTI. As a consequence an additional rule can be introduced as the reference for the FACH measurement occasions for UEs of which data are mapped into the HS-DSCH in general. For example, if the FACH is mapped onto HS-DSCH, the S-CCPCH with the smallest TTI length provided by the network is used as a reference for calculating the length of the measurement occasion; or the S-CCPCH using the most left or right code of the OVSF code tree. Such additional definition for the measurement occasions is required as the S-CCPCH carrying the FACH as used in the definition may be meaningless for some of the UEs.
[0042] Furthermore, the C-RNTI of a UE which receives the FACH via HS-PDSCH needs to be known in the NodeB, or the measurement occasion group, to which it belongs. The corresponding signalling needs to be introduced in the RNC to NodeB signalling and is made use of by the NodeB to MAC-HS. This ensures that during a measurement occasion a UE need not be scheduled or notified because the NodeB takes the measurement occasions into account.
[0043] Furthermore, consideration is required of the fact that the quick repeat scheduling via HS-DSCH may be interrupted by a measurement occasion, as the measurement occasions generally have priority over data reception. This applies particularly if, for the introduction of additional diversity, non contiguous quick repeat/interleaved FACH mapped on HS-PDSCH scheduling patterns, were defined. Thus, if a quick repeat transmission is interrupted by a measurement occasion it shall be resumed directly after terminating the measurement occasion with the same settings applied to the HS-PDSCH prior the measurement occasion, without any additional HS-SCCH signalling. If the UE evaluates that the reception was already successful, based on that portion of the quick-repeat transmission received prior the measurement occasion, then the UE is not required to receive the remaining part after the measurement occasion and can extend it accordingly until a new HS-SCCH indication arrives.
[0044] FIG. 2 illustrates a typical system in which the proposed method is applied. Terminals, or UEs T 1 , T 2 communicate with a network via a base station, or Node B 4 and a base station controller, or radio network controller RNC 5 . The RNC sends configuration information and measurement information to the Node B. As shown in the example of FIG. 3 , the RNC 5 sends HS-DSCH configuration 6 , FACH configuration 7 , reference TTI and N for measurements 8 and UE specific measurement information 9 , such as C-RNTI.
[0045] The proposals allow for HSDPA to be used in CELL_FACH state without clashing with measurement occasions, which would otherwise not be possible. A system comprising a basestation, a basestation controller and terminals with two operating states, in one of the operating states the times at which the terminal retunes its receiver are unknown to the basestation, which is controlling the allocation of radio resources, and thus the basestation controller informs the basestation of these occasions. A rule can be applied in the event of a collision of a retransmission and a measurement as to the occurrence of the next retransmission. The measurement occasion may be calculated from the identity of the terminal.
[0046] The invention has been described in detail with particular reference to preferred embodiments thereof and examples, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention covered by the claims which may include the phrase “at least one of A, B and C” as an alternative expression that means one or more of A, B and C may be used, contrary to the holding in Superguide v. DIRECTV, 69 USPQ2d 1865 (Fed. Cir. 2004). | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/958,386, filed Oct. 4, 2004, which is a continuation of U.S. patent application Ser. No. 10/268,747, filed Oct. 10, 2002,U.S. Pat. No. 6,799,344, the entire contents of each of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to bedding products (including but not limited to mattresses) and in particular to bedding products having multiple firmness zones.
2. Description of the Related Art
Traditional bedding or seating products have either an inner spring core comprising a plurality of identically configured coil springs arranged in linear columns and rows or an inner spring core comprising a plurality of pocketed coils, also arranged into columns and rows. When such a spring core is used, it is typically covered with a pad or other covering material that surrounds and envelops the spring core. Sometimes, in the case of a bedding product, an additional padding layer known as a “topper” is attached to the top sleeping surface. A topper may also be attached to the bottom sleeping surface as well, so that the mattress can be flipped.
Traditional bedding or seating products typically have one degree of firmness throughout because all of the springs of the spring core are identical.
Alternatively, bedding and seating systems may have a resilient foam core. This foam core may be surrounded by perimeter bolsters, located around the edges of the sleeping or seating surface, i.e., at the head, foot, or sides of a mattress as those terms are known in the art. Foam core mattresses may also include toppers, in addition to a cover.
Also known in the art are bedding or seating products that have increased firmness in certain regions of the sleeping surface, such as about their perimeter edge portions or in the lumbar region. In particular, lumbar support schemes have included coils or foam elements within the core of different stiffness/resiliency from those employed in other regions of the mattress.
Present core systems add to the complexity of mattress assembly by requiring determination of desired firmness prior to core manufacturing. Also, once a core is assembled with a particular lumbar stiffness, it cannot be readily changed.
What is needed is an easily installed, versatile support member that can be placed in a desired sleep surface region late in the manufacturing cycle, so as to simplify the process and reduce costs.
SUMMARY
A versatile support member constructed of a metallic mesh, in some embodiments, is provided in a bedding product. The support member is placed on top of the mattress core (whether foam or spring coil) before the mattress cover is attached. The support member may be constructed of titanium wire in a woven or welded mesh grid or web configuration, although other metals (such as, but not limited to, vanadium, chromium, platinum, molybdenum, nickel, iron, zinc) or alloys thereof may be used. Fiber composites, such as carbon or graphite, may also be used.
The support member is conventionally sized in width (here defined as the dimension running along the length of the mattress) according to the area to be supported. Its length (here defined as the dimension running across the width of the mattress) is selected according to the size of the mattress, e.g., King, Queen, Twin, etc. The support member may be directly attached to the core at the ends of its length or may be secured to the upper or lower border wires by hog rings, stitching, lacing, gluing, or other conventional means. In mattresses lacking border wires, such as all-foam or foam rail systems, the support member may be attached to the foam core itself, or sewn into the cover.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure may be better understood and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawing.
FIG. 1 is an isometric view of a bedding product according to one embodiment of the invention.
FIG. 2 is a partial isometric view of an inner spring core with a support member consisting of a cloth web interwoven with titanium, according to one embodiment of the invention.
The use of the same reference symbols in different drawings indicates similar or identical items.
DETAILED DESCRIPTION
FIG. 1 illustrates, in an isometric view, a bedding product generally and in particular a mattress 10 manufactured according to one embodiment of this invention. Mattress 10 consists of a top sleeping surface 12 , a bottom sleeping surface 14 , a head 15 , a foot 16 , and two side edges 17 . Top sleeping surface 12 and bottom sleeping surface 14 may have a topper (not shown) attached to each of them. The topper may contain one of more layers of fabric, batting, ticking, foam, and/or coiled springs. When present, the foam layer(s) of the topper may include latex and/or synthetic foam, including but not limited to polyurethane foam.
Although omitted for clarity, the topper may be either permanently or removably attached to sleeping surface 12 and 14 . Examples of permanently attached topper, seen in the art, are those that are sewn or bonded onto the mattress cover or those that are encased within a sealed pocket in the mattress cover, yet disposed on the surface of the mattress. Removable toppers are typically attached with a temporary fastener, such as a zipper or hook-and-loop fastener in one or more locations. Either attachment method may be used, or no topper may be supplied.
Mattress 10 may also include a foam core 20 and border wires 40 . Foam core 20 is, in some embodiments, a single, monolithic block of a single type of resilient foam selected from foams having a range of densities (themselves well-known in the art) for supporting one or more occupants during sleep. In one embodiment, foam core 20 is made of any industry-standard natural and/or synthetic foams, such as (but not limited to) latex, polyurethane, or other foam products commonly known and used in the bedding and seating arts having a density of 1.5 to 1.9 and 20 to 35 ILD. Although a specific foam composition is described, those skilled in the art will realize that foam compositions other than one having this specific density and ILD can be used. For example, foams of various types, densities, and ILDs may be desirable in order to provide a range of comfort parameters to the buyer.
Border wires 40 may consist of solid rods, 6 gauge wire, helical coils, or a combination thereof. Border wires 40 may also be omitted.
In an alternative embodiment, foam core 20 may comprise one or more horizontal layers of multiple types of foams arranged in a sandwich arrangement. This sandwich of different foams, laminated together, may be substituted for a homogeneous foam block of a single density and/or ILD.
In a further embodiment, foam core 20 may comprise one or more vertical regions of different foam compositions (including vertical regions having multiple horizontal layers), where the different foams are arranged to provide different amounts of support (also referred to as “firmness” in the art) in different regions of the sleeping surface.
In a further alternate embodiment, foam core 20 may be entirely replaced by a conventional coil spring core, comprised of conventional helical or semi-helical springs known and used in the art today. The springs may also be encased in a fabric pocket, either individually, in groups, or pocketed in strings joined by fabric, all of which are well-known in the bedding art.
Accordingly, the invention is not limited to any particular type of foam density or ILD or even to a homogenous density/ILD throughout foam core 20 . Furthermore, the invention is not limited to any particular type of core.
Note also that the mattresses drawn in FIGS. 1 and 2 are not drawn to scale: the overall mattress dimensions typically fall into the ranges commonly found in the trade and referred to, for example, as Twin, Full, King, Queen, Double, etc.
Returning to FIG. 1 , border wires 40 of a type and construction well-known in the art are placed at the outer vertices of core 20 . Border wires 40 may be used as attachment points for securing foam core 20 (or a spring core) with clips or metal “hog ring” attachment devices currently known and used in the bedding art today. (As noted above, border wires 40 may also be omitted.)
Support member 50 is a metallic mesh material, including but not limited to tape, banding, webbing, open-weave, woven mesh, non-woven fibers, or a welded or stamped grid/mesh configuration. Support member 50 may be attached to border wires 40 at its ends 51 by means of gluing, stitching, lacing, riveting, welding, or by other attachment means currently known or afterwards discovered for attaching fabric-like, planar materials. Alternatively, support member 50 may be attached directly to core 20 by similarly conventional means.
In one embodiment, support member 50 consists of a woven mesh or screen of titanium wire, where the wires are approximately 0.011 to 0.035 inches in diameter and the mesh spacing (i.e., the gap between adjoining wires) is approximately 0.25 inches.
Alternatively, welded grids, rather than woven meshes, may be used for a stiffer feel. The support member could also be stamped or punched from a sheet of metal, leaving a grid or screen pattern.
Non-woven fibers in a plastic or fabric matrix, as well as metal wires or composite fibers (e.g., carbon or graphite) woven with natural or synthetic fibers (e.g., cotton, Kevlar, wool or Nylon cloth) may also be employed. Such a configuration would resemble conventional cloth webbing or banding, but containing (i.e., interwoven with) metal wires or fibers.
FIG. 2 is a partial isometric view of a mattress 200 constructed according to an alternate embodiment. Spring core 210 is shown without cover or embellishment. Note that, as in FIG. 1 , spring core 210 may have attached to its perimeter border wire 220 . Support member 230 may be attached to border wire 220 . In some embodiments, support member 230 consists of a conventional cloth banding material interwoven with titanium fibers or wires.
The diameter of the wires forming the mesh (wire gauge) or diameter of the fibers used, as well as the mesh spacing, may be selected to optimize the stiffness, resiliency, weight, and cost of the product according to the needs of the consumer. Wires or fibers of larger diameter and/or smaller mesh spacing may be selected for increased stiffness, just as smaller diameter wires and/or larger mesh spacing may be chosen for a softer feel. Accordingly, the invention is not limited by the size of the wires or fibers used not their relative spacing.
Support members 50 may consist of a single piece of material or multiple strips of material placed at intervals along the length of the sleeping surface. In an exemplary embodiment, support member 50 is about three to six inches wide, though the exact width depends on the region to be supported. ( FIG. 1 , by way of example and not limitation, shows a single support element 50 disposed in the lumbar region.)
While particular embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from this invention in its broader aspect and, therefore, the appended claims are to encompass within their scope all such changes and modifications as fall within the true spirit of this invention. | 4y
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BACKGROUND OF INVENTION
The most fundamental program resident on any computer is the operating system (OS). Various operating systems exist in the market place, including Solaris™ from Sun Microsystems Inc., Palo Alto, Calif. (Sun Microsystems), MacOS from Apple Computer, Inc., Cupertino, Calif., Windows NT®, from Microsoft Corporation, Redmond, Wash., UNIX, and Linux. The combination of an OS and its underlying hardware is referred to herein as a “traditional platform”. Prior to the popularity of the Internet, software developers wrote programs specifically designed for individual traditional platforms with a single set of system calls and, later, application program interfaces (APIs). Thus, a program written for one platform could not be run on another. However, the advent of the Internet made cross-platform compatibility a necessity and a broader definition of a platform has emerged. Today, the original definition of a traditional platform (OS/hardware) dwells at the lower layers of what is commonly termed a “stack,” referring to the successive layers of software required to operate in the environment presented by the Internet and World Wide Web.
Prior art FIG. 1 illustrates a conceptual arrangement wherein a first computer ( 2 ) running the Solaris™ platform and a second computer ( 4 ) running the Windows® NT platform are connected to a server ( 8 ) via the Internet ( 6 ). A resource provider using the server ( 8 ) might be any type of business, governmental, or educational institution. The resource provider ( 8 ) needs to be able to provide its resources to both the user of the Solaris™ platform and the user of the Windows® 98 platform, but does not have the luxury of being able to custom design its content for the individual traditional platforms.
Effective programming at the application level requires the platform concept to be extended all the way up the stack, including all the new elements introduced by the Internet. Such an extension allows application programmers to operate in a stable, consistent environment.
iPlanet™ E-commerce Solutions, a Sun Microsystems|Netscape Alliance, has developed a net-enabling platform shown in FIG. 2 called the Internet Service Deployment Platform (ISDP) ( 28 ). ISDP ( 28 ) gives businesses a very broad, evolving, and standards-based foundation upon which to build an e-enabled solution.
ISDP ( 28 ) incorporates all the elements of the Internet portion of the stack and joins the elements seamlessly with traditional platforms at the lower levels. ISDP ( 28 ) sits on top of traditional operating systems ( 30 ) and infrastructures ( 32 ). This arrangement allows enterprises and service providers to deploy next generation platforms while preserving “legacy-system” investments, such as a mainframe computer or any other computer equipment that is selected to remain in use after new systems are installed.
ISDP ( 28 ) includes multiple, integrated layers of software that provide a full set of services supporting application development, e.g., business-to-business exchanges, communications and entertainment vehicles, and retail Web sites. In addition, ISDP ( 28 ) is a platform that employs open standards at every level of integration enabling customers to mix and match components. ISDP ( 28 ) components are designed to be integrated and optimized to reflect a specific business need. There is no requirement that all solutions within the ISDP ( 28 ) are employed, or any one or more is exclusively employed.
In a more detailed review of ISDP ( 28 ) shown in FIG. 2 , the iPlanet™ deployment platform consists of the several layers. Graphically, the uppermost layer of ISDP ( 28 ) starts below the Open Digital Marketplace/Application strata ( 40 ).
The uppermost layer of ISDP ( 28 ) is a Portal Services Layer ( 42 ) that provides the basic user point of contact, and is supported by integration solution modules such as knowledge management ( 50 ), personalization ( 52 ), presentation ( 54 ), security ( 56 ), and aggregation ( 58 ).
Next, a layer of specialized Communication Services ( 44 ) handles functions such as unified messaging ( 68 ), instant messaging ( 66 ), web mail ( 60 ), calendar scheduling ( 62 ), and wireless access interfacing ( 64 ).
A layer called Web, Application, and Integration Services ( 46 ) follows. This layer has different server types to handle the mechanics of user interactions, and includes application and Web servers. Specifically, iPlanet™ offers the iPlanet™ Application Server ( 72 ), Web Server ( 70 ), Process Manager ( 78 ), Enterprise Application and Integration (EAI) ( 76 ), and Integrated Development Environment (IDE) tools ( 74 ).
Below the server strata, an additional layer called Unified User Management Services ( 48 ) is dedicated to issues surrounding management of user populations, including Directory Server ( 80 ), Meta-directory ( 82 ), delegated administration ( 84 ), Public Key Infrastructure (PKI) ( 86 ), and other administrative/access policies ( 88 ). The Unified User Management Services layer ( 48 ) provides a single solution to centrally manage user account information in extranet and e-commerce applications. The core of this layer is iPlanet™ Directory Server ( 80 ), a Lightweight Directory Access Protocol (LDAP)-based solution that can handle more than 5,000 queries per second.
iPlanet™ Directory Server (iDS) provides a centralized directory service for an intranet or extranet while integrating with existing systems. The term directory service refers to a collection of software, hardware, and processes that store information and make the information available to users. The directory service generally includes at least one instance of the iDS and one or more directory client programs. Client programs can access names, phone numbers, addresses, and other data stored in the directory.
One common directory service is a Domain Name System (DNS) server. The DNS server maps computer host names to IP addresses. Thus, all of the computing resources (hosts) become clients of the DNS server. The mapping of host names allows users of the computing resources to easily locate computers on a network by remembering host names rather than numerical Internet Protocol (IP) addresses. The DNS server only stores two types of information, but a typical directory service stores virtually unlimited types of information.
The iDS is a general-purpose directory that stores all information in a single, network-accessible repository. The iDS provides a standard protocol and application programming interface (API) to access the information contained by the iDS.
The iDS provides global directory services, meaning that information is provided to a wide variety of applications. Until recently, many applications came bundled with a proprietary database. While a proprietary database can be convenient if only one application is used, multiple databases become an administrative burden if the databases manage the same information. For example, in a network that supports three different proprietary e-mail systems where each system has a proprietary directory service, if a user changes passwords in one directory, the changes are not automatically replicated in the other directories. Managing multiple instances of the same information results in increased hardware and personnel costs.
The global directory service provides a single, centralized repository of directory information that any application can access. However, giving a wide variety of applications access to the directory requires a network-based means of communicating between the numerous applications and the single directory. The iDS uses LDAP to give applications access to the global directory service.
LDAP is the Internet standard for directory lookups, just as the Simple Mail Transfer Protocol (SMTP) is the Internet standard for delivering e-mail and the Hypertext Transfer Protocol (HTTP) is the Internet standard for delivering documents. Technically, LDAP is defined as an on-the-wire bit protocol (similar to HTTP) that runs over Transmission Control Protocol/Internet Protocol (TCP/IP). LDAP creates a standard way for applications to request and manage directory information.
X.500 and X.400 are the corresponding Open Systems Interconnect (OSI) standards. LDAP supports a X.500 Directory Access Protocol (DAP) capabilities and can easily be embedded in lightweight applications (both client and server) such as email, web browsers, and groupware. LDAP originally enabled lightweight clients to communicate with X.500 directories. LDAP offers several advantages over DAP, including that LDAP runs on TCP/IP rather than the OSI stack, LDAP makes modest memory and CPU demands relative to DAP, and LDAP uses a lightweight string encoding to carry protocol data instead of the highly structured and costly X.500 data encodings.
An LDAP-compliant directory, such as the iDS, leverages a single, master directory that owns all user, group, and access control information. The directory is hierarchical, not relational, and is optimized for reading, reliability, and scalability. This directory becomes the specialized, central repository that contains information about objects and provides user, group, and access control information to all applications on the network. For example, the directory can be used to provide information technology managers with a list of all the hardware and software assets in a widely spanning enterprise. Most importantly, a directory server provides resources that all applications can use, and aids in the integration of these applications that have previously functioned as stand-alone systems. Instead of creating an account for each user in each system the user needs to access, a single directory entry is created for the user in the LDAP directory. FIG. 3 shows a portion of a typical directory with different entries corresponding to real-world objects. The directory depicts an organization entry ( 90 ) with the attribute type of domain component (dc), an organizational unit entry ( 92 ) with the attribute type of organizational unit (ou), a server application entry ( 94 ) with the attribute type of common name (cn), and a person entry ( 96 ) with the attribute type of user ID (uid). All entries are connected by the directory.
Understanding how LDAP works starts with a discussion of an LDAP protocol. The LDAP protocol is a message-oriented protocol. The client constructs an LDAP message containing a request and sends the message to the server. The server processes the request and sends a result, or results, back to the client as a series of LDAP messages. Referring to FIG. 4 , when an LDAP client ( 100 ) searches the directory for a specific entry, the client ( 100 ) constructs an LDAP search request message and sends the message to the LDAP server ( 102 ) (step 104 ). The LDAP server ( 102 ) retrieves the entry from the database and sends the entry to the client ( 100 ) in an LDAP message (step 106 ). A result code is also returned to the client ( 100 ) in a separate LDAP message (step 108 ).
LDAP-compliant directory servers like the iDS have nine basic protocol operations, which can be divided into three categories. The first category is interrogation operations, which include search and compare operators. These interrogation operations allow questions to be asked of the directory. The LDAP search operation is used to search the directory for entries and retrieve individual directory entries. No separate LDAP read operation exists. The second category is update operations, which include add, delete, modify, and modify distinguished name (DN), i.e., rename, operators. A DN is a unique, unambiguous name of an entry in LDAP. These update operations allow the update of information in the directory. The third category is authentication and control operations, which include bind, unbind, and abandon operators.
The bind operator allows a client to identify itself to the directory by providing an identity and authentication credentials. The DN and a set of credentials are sent by the client to the directory. The server checks whether the credentials are correct for the given DN and, if the credentials are correct, notes that the client is authenticated as long as the connection remains open or until the client re-authenticates. The unbind operation allows a client to terminate a session. When the client issues an unbind operation, the server discards any authentication information associated with the client connection, terminates any outstanding LDAP operations, and disconnects from the client, thus closing the TCP connection. The abandon operation allows a client to indicate that the result of an operation previously submitted is no longer of interest. Upon receiving an abandon request, the server terminates processing of the operation that corresponds to the message ID.
In addition to the three main groups of operations, the LDAP protocol defines a framework for adding new operations to the protocol via LDAP extended operations. Extended operations allow the protocol to be extended in an orderly manner to meet new marketplace needs as they emerge.
A typical complete LDAP client/server exchange might proceed as depicted in FIG. 5 . First, the LDAP client ( 100 ) opens a TCP connection to the LDAP server ( 102 ) and submits the bind operation (step 111 ). This bind operation includes the name of the directory entry that the client wants to authenticate as, along with the credentials to be used when authenticating. Credentials are often simple passwords, but they might also be digital certificates used to authenticate the client ( 100 ). After the directory has verified the bind credentials, the directory returns a success result to the client ( 100 ) (step 112 ). Then, the client ( 100 ) issues a search request (step 113 ). The LDAP server ( 102 ) processes this request, which results in two matching entries (steps 114 and 115 ). Next, the LDAP server ( 102 ) sends a result message (step 116 ). The client ( 100 ) then issues the unbind request (step 117 ), which indicates to the LDAP server ( 102 ) that the client ( 100 ) wants to disconnect. The LDAP server ( 102 ) obliges by closing the connection (step 118 ).
By combining a number of these simple LDAP operations, directory-enabled clients can perform useful, complex tasks. For example, an electronic mail client can look up mail recipients in a directory, and thereby, help a user address an e-mail message.
The basic unit of information in the LDAP directory is an entry, a collection of information about an object. Entries are composed of a set of attributes, each of which describes one particular trait of an object. Attributes are composed of an attribute type (e.g., common name (cn), surname (sn), etc.) and one or more values. FIG. 6 shows an exemplary entry ( 124 ) showing attribute types ( 120 ) and values ( 122 ). Attributes may have constraints that limit the type and length of data placed in attribute values ( 122 ). A directory schema places restrictions on the attribute types ( 120 ) that must be, or are allowed to be, contained in the entry ( 124 ).
SUMMARY OF INVENTION
In general, in one aspect, the present invention involves a method of addressing an entry in a directory server comprising generating a unique identifier for the entry, creating an encoded address by encoding the unique identifier into a distinguished name, and specifying the entry using the encoded address for a plurality of operations.
In general, in one aspect, the present invention involves a method of addressing an entry in a directory server, comprising generating a unique identifier for the entry, creating an encoded address by encoding the unique identifier into a control, and specifying the entry using the encoded address for a plurality of operations.
In general, in one aspect, the present invention involves a unique identifier-based addressing system for a directory server, comprising a unique identifier generated for an entry and an encoded address created by encoding the unique identifier into a distinguished name. The entry is specified using the encoded address for a plurality of operations.
In general, in one aspect, the present invention involves a unique identifier-based addressing system for a directory server, comprising means for generating a unique identifier for an entry, means for creating an encoded address by encoding the unique identifier with a control, and means for specifying the entry using the encoded address for a plurality of operations.
In general, in one aspect, the present invention involves a unique identifier-based addressing system for a directory server, comprising means for generating a unique identifier for an entry, means for creating an encoded address by encoding the unique identifier into a distinguished name, and means for specifying the entry using the encoded address for a plurality of operations.
Other aspects and advantages of the invention will be apparent from the following description and the appended claims.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 illustrates a multiple platform environment.
FIG. 2 illustrates a block diagram of iPlanet™ Internet Service Development Platform.
FIG. 3 illustrates part of a typical directory.
FIG. 4 illustrates the LDAP protocol used for a simple request.
FIG. 5 illustrates a typical LDAP exchange between the LDAP client and LDAP server.
FIG. 6 illustrates a directory entry showing attribute types and values.
FIG. 7 illustrates a typical computer with components.
FIG. 8 illustrates a typical networked workgroup.
FIG. 9 illustrates a block diagram of state information in one embodiment of the invention.
FIG. 10 illustrates a flowchart of a time-based, single-threaded generation algorithm in one embodiment of the invention.
FIG. 11 illustrates a flowchart of a time-based, multi-threaded generation algorithm focusing on the generator task in one embodiment of the invention.
FIG. 12 illustrates a flowchart of a time-based, multi-threaded generation algorithm focusing on the update task in one embodiment of the invention.
DETAILED DESCRIPTION
Specific embodiments of the invention will now be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency.
The invention described here may be implemented on virtually any type computer regardless of the traditional platform being used. For example, as shown in FIG. 7 , a typical computer ( 22 ) has a processor ( 12 ), associated storage element ( 14 ), among others. The computer ( 22 ) has associated therewith input means such as a keyboard ( 18 ) and a mouse ( 20 ), although in an accessible environment these input means may take other forms. The computer ( 22 ) is also associated with an output device such as a display ( 16 ), which also may take a different form in a given accessible environment. Computer ( 22 ) is connected via a connection means ( 24 ) to the Internet ( 6 ).
Directory servers have been used as a corporate infrastructure component for over a decade. The directory server concept has evolved substantially over this time. Today, the directory industry roughly comprises three major categories: Network Operating Systems (NOS) Directories, Meta-directories, and Application Directories.
NOS directories are the oldest. These directories serve as information storage systems for the NOS. NOS directories are designed to support print-sharing and file-sharing requirements for small to medium-sized networked workgroups as shown in FIG. 8 . The network workgroup shows a first client ( 130 ), a second client ( 132 ), a third client ( 134 ), and a shared printer ( 136 ) with an Ethernet connection ( 138 ) at one location. Using a router ( 140 ), a connection is made to a remote network via a hub ( 142 ). Connected to the hub ( 142 ) is a remote shared printer ( 148 ), a first remote client ( 144 ), a second remote client ( 146 ), and a file server ( 150 ). The entire networked workgroup is able to connect to a wide area network ( 152 ) or the Internet ( 6 ) via the router ( 140 ). NOS directories are also integrated with the operating system. Typical NOS directories include Microsoft® NT Domain Directory and Active Directory for Windows® 2000, Novell Directory Services (NDS), and Sun Microsystems Network Information Service (NIS) for UNIX.
The creation of Meta-directories is a result of the increase in requirement of the directory server from the explosion of e-mail communication. Meta-directories use standard protocols and proprietary connections for synchronizing e-mail systems. However, Meta-directories go beyond e-mail synchronization. Meta-directories integrate key legacy data-systems into a standards-based directory for use by one or more corporate Intranet applications.
Application directories store user information, such as employee, partner, vendor, and customer information, in a single repository for access by multiple applications across multiple heterogeneous systems for up to millions of users. Application directories provide storage for user information, user authentication and access control, and provide the foundation for security for many Internet applications. The primary purpose of the application directory is to support Intranet and E-commerce applications. Application directories serve this role by having such features as Meta-directory capabilities, high-performance, scalability and reliability.
iPlanet™ Directory Server (iDS) is a type of application directory that delivers user-management infrastructure for managing large volumes of user information for e-business applications and services. The iDS provides global directory services by providing information to a wide variety of applications. Until recently, many applications came bundled with their own proprietary databases. However, as discussed above, while a proprietary database can be convenient for a one application environment, multiple databases become an administrative burden if they manage the same information.
The global directory service provides a single, centralized repository of directory information that any application can access. However, giving a wide variety of applications access to the directory requires a network-based means of communicating between the applications and the directory. The iDS uses LDAP to give applications access to the global directory service.
Historically, directory server used the DN to identify and retrieve the entry in the directory. However, when a update function is performed on a DN, the DN changes. Consider the following example. Two clients are updating the same directory entry at about the same time. One of the clients adds an attribute while another renames the entry. If the modify operation reaches the server after the rename operation, modify operation fails since a target DN contained by the operation is stale. If the client had an ability to use a Unique Identifier (UniqueID) of an entry, this problem would be avoided because UniqueID is assigned to an entry once and never changes. Thus, UniqueID provides a good way to unambiguously refer to an entry in a distributed or replicated environment.
Multi-master replication is a replication model where updates are applied on multiple servers. Multi-master replication comes in two flavors: synchronous and asynchronous. In the case of synchronous multi-master replication, an update is applied only after all updateable servers are notified. With asynchronous multi-master replication, entries can be written and updated on any of several updateable replica without requiring communication with other updateable replicas before a write or update operation is performed. As found in the iDS, multi-master replication requires directory entries to be unabmiguously identified, even in the presence of renaming operations. Therefore, UniqueID-based addressing becomes critical for iDS to work properly when multi-master replication occurs. Consider a second, similar example where two masters are also present. The entry is renamed on one master and modified on the other master. When renaming operation is replayed to the second master, the operation succeeds resulting in the desirable state. But when the modify operation is replayed to the first master, the operation fails because the entry with supplied DN no longer exists. As a result, two masters end up in a different state. On the other hand, if the entry had been specified by UniqueID rather that the DN, both operations succeed resulting in a consistent state across servers.
Understanding UniqueID-based addressing starts by defining UniqueID. UniqueID is a 136 bit number with the first octet set to the identifier type and the remaining bits set to the identifier itself. In an embodiment of this invention, the first octet is set to zero which results in the remaining 16 octets (128 bits) being generated in accordance with UUID specification. UUID stands for Universal Unique Identifier and refers to a specification published by Open Group. Further discussion about Open Group is beyond the scope of this discussion. For more information, see http://www.opengroup.org/overview/who_we_are.htm. Further discussion about UUID is beyond the scope of this discussion. For more information, see http://www.opengroup.org/onlinepubs/9629399/apdxa.htm.
The first step to establishing UniqueID-based addressing for iPlanet™ Directory Server is to generate UniqueID for each entry. One implementation of UniqueID generation supports both time-based and name-based UUIDs. Time-based generation is an ID generated based on a current system time and is globally unique. Name-based generation is based on a byte stream called “name.” Time-based IDs are most common. The name-based IDs are useful if the same set of UniqueIDs need to be generated independently on two separate systems. In an embodiment of this invention, the UniqueID generated does not guarantee uniqueness, but makes repetition very unlikely.
Referring to FIG. 9 , the UniqueID generator maintains state information ( 102 ) including a system time ( 90 ), a time sequence number ( 92 ), a nodeid ( 94 ), a clock sequence ( 96 ), and a flag ( 98 ). A timestamp portion ( 100 ) of the state includes two parts, namely system time ( 90 ) obtained through a call to time plus time sequence number ( 92 ) that keeps IDs generated within the exact same second distinct. Up to 10^7 IDs can be generated per second. The timestamp ( 100 ) is a 60 bit value in Universal Time Coordinate (UTC) as a count of 100 nanosecond intervals since 00:00:00.00, Oct. 15, 1582 (date of Gregorian reform to the Christian calendar) that differentiates IDs generated on a same system. Nodeid ( 94 ) is designed to differentiate between IDs generated on different systems. Clock sequence ( 96 ) is used to ensure uniqueness if clock is set back or nodeid ( 94 ) has changed. The flag ( 98 ) indicates whether the state information has been saved during server shutdown.
State information is stored persistently either in a file or in a directory entry as a single binary attribute. The state information is read into memory during startup and written back to memory during shutdown. The first time UniqueID generator is started, state time is set to current system time, time sequence is set to zero, nodeid is set to cryptographic strength random number, clock sequence is set to a random number. If disorderly shutdown is detected during server startup, the clock sequence is set to a random number to reduce risk of duplicates.
The implementation of UniqueID generator uses randomly generated nodeid rather than a Network Information Center (NIC) address. If NIC is used, the state information is required to be shared among all servers running on the same host causing a significant reduction in performance.
Two different types of time-based generation algorithms include a single-threaded generation and a multi-threaded generation. The single-threaded generation has the following steps as shown in FIG. 10 . First, obtain current system time (step 110 ). If current system time equals state time (step 112 ), then the time sequence number is incremented (step 114 ). If not, if the current time is greater than state time (step 116 ), then set state time to system time (step 118 ) and set time sequence to zero (step 120 ). If not, set state time to system time (step 122 ), set time sequence to zero (step 124 ), and increment clock sequence (step 126 ). Next, format UniqueID using state information (step 128 ).
The multi-threaded generation algorithm includes two separate tasks. A generator task is executed for each generated ID, an update task is executed periodically to update state information. Referring to FIG. 11 , the generator task starts by acquiring read lock for state information (step 130 ). Read lock prevents updating of the state information data until read is unlocked. Next, time sequence is atomically incremented (i.e., the value is correctly incremented in a multi-threaded environment without interference by other threads) (step 132 ). The ID is generated based on the state information (step 134 ) followed by releasing read lock (step 136 ). As shown in FIG. 12 , the update task starts with obtaining a a write lock (step 139 ) to prevent other threads from reading or modifying state information. Next, system time is obtained (step 140 ). If system state does not equal state time (step 142 ), then acquire write lock for state information (step 144 ). Write lock prevents writing of the state information data until write is unlocked. If system time is less than state time (step 146 ), then increment clock sequence number (step 148 ). Next, set state time to system time (step 150 ). Then, set time sequence to zero (step 152 ) followed by releasing write lock (step 154 ).
Name-based generation algorithm takes a UUID that differentiates name spaces and a byte stream to generate MD5 digest of the data. Given the same namespace UUID and the same input stream, a same UniqueID is generated. MD5 digest is a 128 bit value computed from an arbitrary sized input stream using MD5 digest algorithm described in RFC 1321. Given the same input the algorithm is guaranteed to produce the same result. Further discussion of MD5 Digest is beyond the scope of this discussion, however more information may be found at http://www.faqs.org/rfcs/rfc1321.html.
Random generation algorithm takes a UUID that is randomly generated using physical source of randomness or cryptographic strength random number generator.
Once UniqueID is generated, a method of addressing UniqueID is necessary to be able to specify the entry by UniqueID for search, delete, modify and rename operations. Because the only way to address an entry for delete, modrdn or modify operation is through the DN, at least two options exist. The first option is to modify target DN to include addressing information. The second option is to define a new control to carry the addressing information.
Modifying the target DN by encoding addressing information starts by reserving some of the DN namespace for alternative addressing mechanisms. The general form of the addressing string is: <unique attribute value assertion, [<dn>|<databaseid>], addressingmechanism=OID (where OID is a unique identifier assigned to objects). Examples of encoding addressing information in the DN follow. First, a situation where address by UniqueID and backend is unknown is represented by UniqueID=<uuid>, addressingmechanism=<oid>. Second, a situation where address by UniqueID, DN provided to as a hint of which backend is represented by UniqueID=<uuid>, <DN>, addressingmechanism=<oid>. Third, a situation where address by UniqueID, database id uniquely indentifies the backend is represented by UniqueID=<uuid>, databaseid=<genid>, addressingmechanism=<oid>. Many variations of this theme exists, but the idea of using the OID to select the addressing mechanisms make it extensible.
An advantage of the encoding addressing information approach is the allowance of a uniform addressing scheme where the entry is always addressed by the DN. Normal LDAP operations can be used to locate an entry based on the entry's UniqueID.
The second option is defining a control that contains addressing scheme OID and addressing data. As an example, each UniqueID-based search contains OID of the addressing scheme, UniqueID of the requested entry and a flag telling the server whether DN should be used as a hint or ignored altogether. The advantage of this option is no changes are required to LDAP specification.
Applications of UniqueID-based addressing is utilized by the following operations. Replicated modify, delete, and modrdn operation are replayed using UniqueID-based addressing. Also, UniqueID-based addressing may be beneficial for non-replicated operations. The implementation details depend on the addressing scheme selected. Operations originated at the replication module use target DN or serverID as the base of the address. Using serverID is more efficient if the entry has been deleted because the serverID prevents searching multiple backends.
While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims. | 4y
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BACKGROUND OF THE INVENTION
Prior Art
The following is a tabulation of some prior art that presently appears relevant:
U.S.A. patents
Patent Number
Issue Date
Patentee
5,068,883
Nov. 26, 1991
DeHaan, et al.
8,428,217
Apr. 23, 2013
Peschmann
8,054,203
Nov. 8, 2011
Breed, et al.
5,449,864
Sep. 12, 1995
Beatty, et al.
This invention provides a means to identify if there are concealed items in an automobile. Automobiles are often used for transporting illegal and contraband materials such as illegal drugs, cash from illegal activities, untaxed goods, counterfeit goods, and other contraband. Automobiles can also be used as weapons when explosive materials are hidden within them. This invention provides a means to identify if there are hidden materials within an automobile, and provides advantages over the prior art.
Several methods use radiation to examine a vehicle and determine if there are hidden materials. One system uses dual energy X-ray CT scanning to examine objects and determine what kinds of materials are within the objects, including objects that are vehicles. The disadvantages of this system is that the apparatus to generate the dual energy is large and not readily mobile, and requires considerable effort to move from one location to another. Also this system requires a large and significant source of electricity to power the dual energy X-ray generating devices that are used to examine the objects. The dual energy X-ray radiation also poses a health risk to persons who may be exposed to it, so that it cannot be used to examine a vehicle if there are persons within the vehicle.
Another method uses a first substructure and a second substructure and the vehicle must be positioned between the substructures, and then ultrasonic sound is used to examine the vehicle and determine if there are objects within the vehicle. The disadvantage of this method is that it requires two separate structures that the vehicle must be driven between and the substructures themselves are not readily mobile and easy to carry by a single person.
One method used to detect contraband uses Infrared Light to examine a vehicle and detect certain analytes of material, Analyte Detection with Infrared Light. The infrared light is tuned to excite certain kinds of particles so that it can be configured to detect certain materials, such as those contained within explosive substances. To examine an entire vehicle at one time, requires a large number of infrared light sources as part of a large apparatus. The method is not readily mobile. Also this method cannot be used to determine if there are materials hidden within the hollow cavities of an automobile, such as the hollow space within the door of an automobile, where infrared light cannot penetrate without dismantling the door.
Another method, Vehicle Security Inspection System, uses a large apparatus and a conveyer belt that the vehicle is driven upon and then the conveyer belt is used to ferry the automobile past sensors of different types to detect contraband within the automobile. The permanent installation version of this method is large and not readily moveable from one location to another. A conveyer belt large enough to transport and carry an entire automobile cannot be carried by a single person from one location to another.
One method, Motor Vehicle Screening Apparatus and Method, relies on large, heavy machines to weigh the vehicle and compare the weight of the vehicle to that of an empty vehicle of the same type, to determine if the vehicle has additional materials in it. This is a large machine not readily moveable and takes a significant amount of time to prepare and deploy. The method uses an apparatus that is not readily mobile, and cannot be moved from one location to another by a single person.
Also, all of these methods do not automatically come with a connection to the internet that allows the methods to retrieve and send data to a central computer server connected to the internet. A significant effort would be required to setup these methods to report the results of their deployment and usage to a central computer server connected to the internet. Most Mobile Devices contain at least one means of connecting to the internet, and many have multiple means to connect to the internet.
SUMMARY OF THE INVENTION
The object of this invention is to provide a device to determine if there are concealed items within an automobile, or vehicle. The term “Mobile Device” specifically refers to certain kinds of mobile telephones, known as “Smartphones”, such as the Apple iPhone, Android Phone, Windows Phone, and Blackberry Phone. Also, the term Mobile Device is often used to refer to tablet computers such as the Apple iPad, Android Tablet Computer, and Windows Tablet Computer. Using the Google internet search engine with the term “Mobile Device” will show that the term “Mobile Device” is specifically used to refer to these kinds of devices. These devices contain all the components needed to implement this invention. A device that runs a computer operating system, and a custom software application that runs on and controls the Mobile Device.
By measuring the frequency of vibration with which a surface of the automobile vibrates, and comparing it to the frequency of vibration for that particular kind of automobile when it is empty of hidden materials, it can be determined if there are hidden materials within the automobile. The mass of an object affects the frequency of vibration, when an automobile has hidden materials within it, it adds mass to the automobile and causes the frequency of vibration of different surfaces of the automobile to change.
Many Mobile Devices contain all of the necessary components to implement this invention, A computer processor chip and memory chips that allow a computer operating system and software to run on the device. An accelerometer, an electronic device that measures vibration and motion. An electronic vibrator that causes the Mobile Device to vibrate. For devices that do not specifically have an electronic vibrator to vibrate the device, the speaker of the device that emits sounds can be used to vibrate the device as well. A computer operating system, that manages the components of the Mobile Device and allows for the development of custom software using a programming language such as Java, Objective C, Swift, C#, C++, or C. A computer database library that allows for the storage and retrieval of data using a software application. A touch screen display that allows the Mobile Device user to control the Mobile Device and software that runs on it. A Global Positioning System (GPS) sensor that allows the latitude and longitude location of the Mobile Device to be determined. Some Mobile Devices also use the GLONASS global location system to get latitude and longitude. A connection to the internet using the cellular communications network the Mobile Device uses, and/or a connection to the internet using a wireless internet router, known as WiFi. The means of connection to the internet can also provide the Latitude and Longitude location of the device through Google Maps, which tracks latitude and longitude of network routers and cellular towers. A battery that serves as the source of electricity for all of the components within the Mobile Device, and also the Mobile Device can be connected to a wall outlet source of electricity, and/or an automobile electricity source device charging cable.
The Mobile Device is small and lightweight, and can be transported by a single person without difficulty. It also has a battery that allows for the Mobile Device to be used for several hours when fully charged, without the need of being plugged in to a wall outlet source of electricity and/or other source of electricity such as an automobile.
This invention is implemented using the Mobile Device by the following steps (a) Data about the automobile being inspected is entered into the Mobile Device using the touch screen of the Mobile Device (b) a long side of the device is placed against the part of the automobile being inspected (c) User presses a button on the touch screen of the device that causes the device to vibrate and apply energy to the surface of the automobile, and cause that surface to vibrate (d) The accelerometer contained within the device measures the vibration (e) The custom device software compares the vibration frequency during the test of the automobile, the test frequency, to that of the vehicle when it is empty of concealed items, the baseline frequency of vibration. and determines if there is a significant difference, that may indicate concealed materials (f) A simple PASS or FAIL message is displayed to the user depending on the results of the comparison (g) The results of the test are stored by the application software in a computer database on the Mobile Device and reported by web service to the central internet server, where the deployment of this Device across a geographic area can be monitored from a central location.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 —a drawing showing how the device is used to test an automobile for concealed items
FIG. 2 —an outline of a mobile device and it's list of components used by this invention
FIG. 3 —a flowchart showing the process for obtaining Normal Frequencies of Vibration
FIG. 4 —a flowchart that shows the basic operation of the invention
FIG. 5 —a flowchart showing the decision process while testing the automobile for concealed items
DETAILED DESCRIPTION OF THE INVENTION
Solid surfaces, including surfaces of metal, vibrate with a frequency of vibration when energy is applied to that surface, such as a tap or strike with another solid object. The following mathematical formula shows how the exact frequency of vibration, fn, is determined, the formula uses the number value K, the elastic constant, and the mass of the object, M, to determine the exact frequency of vibration. When K stays the same for the particular surface but mass M changes, the frequency of vibration also changes. Thus changes in mass of an object also cause changes in the frequency of vibration of that particular object. This is the basis of this invention and how it is used to determine if there are concealed materials within an object, when the object is an automobile.
f
n
=
1
2
π
K
M
By applying energy to the surface of an automobile, and causing that surface to vibrate, then measuring the frequency of vibration, and then comparing that frequency of vibration to the known frequency of vibration for that automobile when the automobile is empty of concealed items, it can be determined if there are concealed items within the automobile. Most automobiles contain hollow cavities where items can be hidden, such as the hollow cavity between the outside surface of an automobile door and the inside surface of that automobile door, hidden items in this hollow cavity affect the mass M of the surface of the door, causing it to vibrate with a different frequency than when that hollow cavity is empty. The same process can be applied to other parts of the automobile. Also, when a significant object of a certain size is contained anywhere within the automobile, it will affect the frequency of vibration of all surfaces of the automobile. This is the basis of this Device and how it uses vibration to determine if there are hidden materials within an automobile.
Many mobile devices provide all of the components needed to implement this invention. The components are listed here. A computer processor chip and computer memory chips. An accelerometer electronic hardware component. An electronic vibrator hardware component, including speakers. A touch screen interface. A computer operating system. A computer database. A global positioning system (GPS) or GLONASS sensor. Electronic components that connect to the internet through cellular communications network. Electronic components that connect to the internet through a wireless internet router, or Wifi. A custom software application that allows the user of the Mobile Device to examine an automobile and determine if there are concealed items within the automobile by comparing the vibration value of the surface of an automobile, the test frequency, to the known vibration value, the baseline frequency, of an automobile free of contraband and hidden materials.
The mobile device contains a computer processor chip and computer memory chips that allow for software to operate on the device and manage all of the components of the device. The Mobile Device has a computer operating system software installed on it that provides for many features on the device, including the management of the components of the device, making device calls, sending text messages, allowing for users to interact with the operating system using a touch screen interface, the Graphical User Interface (GUI), and allows for the running of custom software applications that are written using a programming language such as Java, Objective C, Swift, C#, C++, and/or C.
The Mobile Device contains an accelerometer, an electronic sensor that measures vibration. This electronic component can be accessed using software. The rate of vibration measured by the accelerometer can be read by the software and stored in a variable to be used within the software, and also stored in a database on the Mobile Device. Most Mobile Devices contain an accelerometer.
The Mobile Device contains an electronic vibrator that causes the Mobile Device to vibrate. Most Mobile Devices contain an electronic vibrator specifically for vibrating the device. Normally this is used to put the Mobile Device in a “silent” mode so that the device does not make a noise when receiving an incoming call or incoming text message, instead the device vibrates. Also many software games for Mobile Devices use the electronic vibrator This electronic component can be accessed and controlled using software. It can be used to apply energy to the surface of an automobile and cause the surface of the automobile to vibrate. For those tablet computer devices that do not have an electronic vibrator specifically to vibrate the device, those devices instead can use the sound speaker built-in to the device to cause the device to vibrate.
The Mobile Device contains a touch screen interface which allows the user to interact and control the Mobile Device.
The Mobile Device contains a database library, which allows for the creation of computer databases which are accessed and controlled using the Structured Query Language (SQL) computer language.
Most Mobile Devices also contain a sensor that can determine the Latitude and Longitude location of the Mobile Device using the GPS or GLONASS Satellite network. Data from this GPS or GLONASS sensor can be accessed using software. Also this invention could also work with Mobile Devices that do not have GPS or GLONASS to get the Latitude and Longitude location of the device, those devices can instead get their location from the connection to the internet using the Google Maps system, which identifies the location of the device by way of the known location of internet routers and cellular network towers near the device.
Many Mobile Device contains components that allow it to connect to the internet through the cellular communications network that handles device calls and text messages coming from and going to an Mobile Device. For Mobile Devices that do not have cellular network connectivity, that feature can be added to the device through the use of attachments that connect to the cellular network and plug in to the USB port of the device, so called “Dongles”. Many Mobile Devices can also connect to the internet through a wireless internet router where such a router is available and within proximity of the Mobile Device. This is often referred to as WiFi. Data can be sent and retrieved from the internet using software. The list of components of this invention are summarized in FIG. 2 of the drawings, along with the outline of a particular Mobile Device, The Motorola Droid Smartphone.
Before this Device can be used to determine if hidden materials are contained within an automobile, a database must be built that contains the vibration values of empty automobiles to be used as the Baseline Frequencies of Vibration for comparisons. A part of this invention allows for this task to be done.
The vibration frequency measurement of an automobile empty of concealed items not normally a part of the automobile is called the Baseline Frequency. A Baseline Frequency applies to a type of automobile and part of the automobile. The Baseline Frequency can be the empty vehicle vibration frequency measurement for an automobile door. The baseline frequencies are stored in the Mobile Device computer database and also optionally on a server computer that can be accessed through the Mobile Device network connection, if available.
The data used by this invention and stored in the Mobile Device database consists of the following at a minimum:
BASELINEFREQUENCY data
Fields:
MANUFACTURER, a text field containing the name of the automobile Manufacturer/Make (optional)
MODEL, a text field containing the model of a car (optional)
TYPE, a text field containing the type of automobile (car, sport utility vehicle, van, or truck)
PART, a text field containing the auto part (door, bumper, quarter panel, trunk, fuel tank, dashboard)
BASELINEFREQUENCY, a real field that stores a floating point number, for the frequency of vibration.
ASSIGNMENTINFO data
Fields:
KEYID, a randomly generated string of data used to be the unique identifier of a single device
VARIANCE data
Fields:
VARIANCE, a number to be used as the natural variance of vibration values
TESTS data
Fields:
DATETIME, text field, the data and time of the test of the automobile
LATITUDE, number, latitude location of the device during auto test
LONGITUDE, number, longitude location of the device during auto test
MANUFACTURER, text field, the manufacturer/make of the automobile being tested (optional)
MODEL, text field, the model of the automobile being tested
COLOR, text field, the color of the automobile being tested (optional)
TYPE, text field, the type of automobile being tested (car, sport utility vehicle, etc.)
PART, text field, the part of automobile being tested (bumper, door, etc.)
TESTFREQUENCY, number, the average vibration of the auto surface during the test
PASSFAIL, text field, the results of the test of the auto, either PASS or FAIL.
Before this invention can be effectively used, a database of the known Baseline Frequencies of Vibration for automobiles that are free of concealed items not normally a part of the automobile, must be built. This invention also provides the means to do this task in a similar fashion to testing for concealed items. It consists of the following steps which are summarized in a flowchart in FIG. 3 of the drawings:
(1) Power on the Mobile Device and start the custom software application on the device. (2) In the first screen of the software application, the user selects the Manufacturer/Make of the automobile from a user interface control, then clicks the continue button to go to the next screen. The manufacturer chosen is stored in the Mobile Device database. (3) The next screen of the custom software application, the users selects the type of the automobile being tested, such as 2 door car, 4 door car, truck, sport utility vehicle, etc. The users selection is stored in the Mobile Device Database. (4) The next screen of the custom software application, the user selects the part of the automobile being tested. Parts such as quarter panel, bumper, door, boot, trunk, bonnet, dashboard, and fuel tank. The users selection is stored in the Mobile Device database. (5) The user is now at the screen of the custom software application where the automobile will be tested to get the Baseline Frequency of Vibration. When this screen is opened, the accelerometer is initialized and ready to begin measuring vibration. On this screen of the application is a button titled INITIATE TEST FOR BASELINE FREQUENCY or similar words the user can understand. The user then takes the device and places a narrow edge against the surface of the automobile part being tested and holds the Mobile Device against the surface of the automobile. The user then clicks the button titled INITIATE TEST FOR BASELINE FREQUENCY on this screen. The Mobile Device then begins vibrating by way of its electronic vibrator hardware, or by way of its sound speaker, while the device is vibrating, the average vibration value is is measured by the accelerometer hardware and stored as the Baseline Frequency of Vibration, The user can stop holding the Mobile Device against the automobile surface once it stops vibrating. (6) The custom software application stores the results of the test, including the Baseline Frequency of Vibration, in the device database and/or optionally also reports the results of the test and the data involved with the test to a server computer through the network connection, if a network connection is available. The server computer can then make the data available to other Mobile Devices for use in testing automobiles for concealed items.
The detailed process using this invention to do a test of an automobile for the presence of concealed items is similar, composed of the following steps, which are summarized in flowcharts in FIG. 4 and FIG. 5 of the drawings:
(1) Power on the Mobile Device and start the custom software application on the device.
(2) In the first screen of the software application, the user selects the Manufacturer/Make of the automobile from a user interface control, then clicks the continue button to go to the next screen. The manufacturer chosen is stored in the Mobile Device database.
(3) The next screen of the custom software application, the user selects the Color of the automobile, then clicks the continue button to go to the next screen. The color chosen is stored in the Mobile Device database.
(4) The next screen of the custom software application, the users selects the type of the automobile being tested, such as 2 door car, 4 door car, truck, sport utility vehicle, etc. The users selection is stored in the Mobile Device Database.
(5) The next screen of the custom software application, the user selects the part of the automobile being tested. Parts such as quarter panel, bumper, door, boot, trunk, bonnet, dashboard, and fuel tank. The users selection is stored in the Mobile Device Database.
(6) The user is now at the screen of the custom software application where the actual test of the automobile will take place. When this screen is opened, the location sensor (GPS, GLONASS, NETWORK) is initialized and registers the latitude and longitude location of the device and where the automobile test is taking place. The accelerometer is also initialized and ready to begin measuring vibration. On this screen of the application is a button titled INITIATE TEST FOR CONCEALED ITEMS, or similar words the user can understand. The user then takes the device and places a narrow edge against the surface of the automobile part being tested and holds the Mobile Device against the surface of the automobile. The user then clicks the button titled INITIATE TEST FOR CONCEALED ITEMS on this screen. The Mobile Device then begins vibrating by way of its electronic vibrator hardware, or by way of sound speaker. While the device is vibrating, the average vibration value is measured by the accelerometer hardware and stored as the Test Frequency of Vibration, The user can stop holding the Mobile Device against the automobile surface once it stops vibrating.
(7) The custom software application compares the Test Frequency of Vibration to the Baseline Frequency of Vibration for that type and part of automobile, stored in the Mobile Device database, or available from a server computer through network connection, taking into account the variance of vibrations, if a significant difference exists between the two, that may indicate the presence of concealed items in the automobile. A small amount of concealed material of say only 1 or 2 kilograms (2.2 or 4.4 pounds) may not affect the Test Frequency of Vibration, but a large amount of concealed materials, say 25 to 50 kilograms (55 pounds to 110 pounds) will have a significant affect on the Test Frequency of Vibration of the surface of the automobile, since Mass affects the frequency of vibration, so much so that it will be noticeably different than the Baseline Frequency of Vibration for when an automobile is free of concealed items not normally a part of the automobile. The Mobile Device accelerometer hardware provides the means to determine the frequency of vibration. The Mobile Device electronic vibrator, or sound speaker, provides the means to apply energy to the surface of the automobile causing that surface to vibrate.
(8) The custom software application stores the results of the test in the device database and/or also optionally reports the results of the test to a server computer through the network connection, if a network connection is available. This invention is designed to have its own database of Baseline Frequency values so that it can operate in the event that there is no network connection through the cellular network or through a wireless router, “WiFi”.
OTHER EMBODIMENTS
The process involved with this invention could also be used with different kinds of devices that measure vibration, like a laser vibrometer, and different devices that apply energy to the surface of an automobile causing that surface to vibrate. | 4y
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RELATIONSHIP TO OTHER APPLICATION(S)
[0001] This application is a continuation-in-part of U.S. Ser. No. 13/553,795 filed on Jul. 19, 2012 and claims the benefit of the filing date of U.S. Provisional Patent Application Ser. No. 61/804,620 filed on Mar. 22, 2013, the disclosure(s) of which are incorporated herein by reference.
GOVERNMENT RIGHTS
[0002] This invention was made under contract awarded by US Department of Energy, Contract Number DE-EE0006378 and DE-SC0009196. The government has certain rights in the invention.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] This invention relates generally to systems for transporting and installing large photovoltaic modules, and more particularly, to a photovoltaic module handling system that enables substantially automated and rapid replenishment of photovoltaic modules in a solar panel array.
[0005] 2. Description of the Related Art
[0006] Co-pending patent application U.S. Ser. No. 13/553,795 describes an automated system for photovoltaic (PV) power plant construction. In this system, robotic shuttles deliver large panel assemblies to their mounting positions on a ground-mount rack in the form of an elevated delivery track from load stations at the end of each row of racks in a solar panel array. This system is a marked improvement over manual delivery of large panel assemblies to their final mounting positions.
[0007] A common theme in the utility scale, photovoltaic power plant construction has been to achieve cost reduction by using larger building blocks for construction. One way to do this is to pre-assemble movable PV panels into larger arrays, either at the panel manufacturer, at a local warehouse, or at the construction site. These larger building blocks must then be brought to the field for installation on a support rack systems. Field labor is required to assist in positioning the panels in their final mounting position, to install mounting clamps, and to interconnect electrical wiring. Field labor, particularly if utilizing building trades, is paid at a much higher labor rate than factory labor.
[0008] There is, thus, a need to reduce labor costs per panel by replacing field labor with factory labor.
[0009] Of course the larger building blocks are heavier to handle. Expensive aluminum rails have been used on the panels to reduce weight. There is, therefore, a need to reduce material costs by replacing panel aluminum rails with lower-cost materials, such as galvanized steel, as well as reducing the amount of components, such as clamps, required to complete the installation.
[0010] While larger building blocks can improve overall installation rates, the size and weight of both panel arrays, and large monolithic panels, means that they can no longer be handled by manual labor alone. Therefore, heavy equipment (e.g., cranes, boom trucks, ground-mounted robotic arms) may be required to deploy such panels safely. The use of heavy equipment requires some initial site grading and, frequently, re-grading as heavy equipment can create deep mud tracks and treacherous conditions, especially post-rain and snowfall. It can even bring construction to a halt until the surface is stabilized. Personnel safety is a big issue when heavy equipment is used on the work-site. In addition, special training may be required for use and maintenance of such equipment. There is, therefore, a need for an installation system that does not require the use of heavy equipment to install panel arrays.
[0011] It is therefore, an object of this invention to provide an solar panel installation system that utilizes larger building blocks, such as panel modules, but that does not require the use of large, or heavy, equipment.
[0012] In co-pending application U.S. Ser. No. 13/553,795, small automated PV shuttles, sometimes referred to as drones, support and carry panel assemblies, weighing up to 120 kg, to their final rack-mounted position. No heavy equipment is required to travel between rack rows during installation, and the size of installation crews is reduced. However, while the shuttles utilized can handle pre-panelized framed modules. However, for maximum cost savings, pre-panelization of frameless modules is highly preferred. Frameless modules have the advantage of lower cost (no aluminum frame) and the frames so not have to be grounded, which is a major cost adder.
[0013] However, frameless modules are more fragile at the edges and corners. Therefore, greater care is required when handling frameless modules. There is, thus, a need for a system that can safely utilize frameless modules.
[0014] It is another object of this invention to provide a system that can take full advantage of the economies of scale and the ability to use pre-panelized modules, and particularly, frameless pre-panelized modules.
SUMMARY OF THE INVENTION
[0015] These, and other, objects features, and advantages are achieved by the present invention entire solar panel arrays are populated from a single, centralized material handling location by using a specialized assembly jig that serves as a fork lift pallet and pre-positions a stacked-up array of solar panel modules for delivery to a ground-mount rack of a solar array. An advantageous aspect of the present invention is that the manual work in assembling the solar panel modules, including the installation of low-cost, adhesively applied rails that will be used to grip and transport the panels to their final destination, as well pre-wired electrical components, is performed in a weather-protected location on smooth ground and can be located either on-site or off-site.
[0016] In addition to the foregoing, the manual handling risk to the panel is minimized because the frameless solar panel modules are pre-panelized, and most advantageously, pre-panelized in a specialized assembly jig that will be used to transport the pre-panelized solar panel arrays directly to the field array. Field-handling of PV modules is, therefore, limited to one simple loading motion at the end of the array. The rack rail-mounted robotic shuttles then take-over and deliver the PV module to its final position. By minimizing human handling of the modules, particularly at the critical final installation step where module corners are easily struck and damaged, the risks related to frameless modules are minimized and the associated cost savings can be fully realized.
[0017] In a specific embodiment of the invention, a specialized PV assembly jig and fork-lift transport pallet, herein designated “pallet jig,” is provided to support, protect, and align, PV panels stacked in an upside down position, opposite to their operational position. The pallet jig is configured to be transported on the tines of a forklift truck for further transport, or to its final destination at the field array. Once the pallet is transported to the load station at the end of a row of solar panel racks in the field array, a robotic loader lifts the upside down PV panels from the combined PV panel assembly jig and forklift transport pallet in an arcing overhead motion that lifts, tilts, and deposits the PV panels in an upright position at the loading station of a railed rack support as ground-mounted in a solar panel field array.
[0018] In a method embodiment of the invention, panel assembly is accomplished while each panel of the module is uppermost on the pallet jig, and is oriented upside down (or sunny-side-down) for ease of application of the components to the underside of the PV solar panels. The pallet jig holds the individual PV solar panel modules in place in a stacked arrangement, referred to herein as a stack-up, by upright support members attached to the horizontal stringers of the pallet-like jig structure on the external supports on the back side and the shorter, longitudinally-spaced apart sides of the pallet. The upright corner support members on the longitudinally-spaced apart sides of the pallet jig are pivotably, or removably, connected and held in place by a latching mechanism, for example, so that they can be laid out of the way for ease of removing the modules from the stack-up.
[0019] The upright corner support members, as well as the upright support members on the back of the pallet jig, are provided with protrusions, illustratively lugs, for positioning a solar panel module in place relative to a second solar panel module installed on top of the first solar panel module, as series of modules being so stacked to comprise a multi-layer stack-up. The protrusions interengage with rails that are installed on the backside of the solar panels, illustratively, by an adhesive strip. The panels being supported and spaced apart by the lugs so that the height of the applied adhesive strip remains uniform.
BRIEF DESCRIPTION OF THE DRAWING
[0020] Comprehension of the invention is facilitated by reading the following detailed description, in conjunction with the annexed drawing, in which:
[0021] FIG. 1 is a perspective view of a combined PV panel assembly jig and forklift transport pallet that is prepared in a panelization station, such as shown in FIG. 12 , for use in the practice of a specific illustrative embodiment of the invention;
[0022] FIG. 2 is a fragmentary perspective view of the PV panel assembly jig and fork lift pallet of FIG. 1 in an empty condition;
[0023] FIG. 3 is a perspective view of a sub-assembly of a roller-mounted movable support plate with a pivotable jig support channel bar hinge-coupled to the movable plate, and carrying at each end an adjustable draw latch, the sub-assembly is also shown pallet-mounted in FIG. 2 ;
[0024] FIG. 4 is a fragmentary enlarged perspective view of the details of a slide-out end assembly of the pallet jig illustrating the adjustable draw latch and location-establishing pallet jig components as also seen in FIGS. 2 and 3 on a smaller scale;
[0025] FIG. 5 is a fragmentary perspective sub-assembly view of one of the thin-gauge steel rails (in the form of a hat-style channel) secured by dual beads of a commercially-available adhesive to the underside surface of a PV panel module during the pallet-jig panelization process of the present invention;
[0026] FIG. 6 is a fragmentary perspective view illustrating a portion of a jig locating and lug support strip affixed to and carried by one of the pallet jig upright support posts, the strip having protruding positioning lugs for supporting and positioning respective PV glass panels with their associated support rails as each PV module is being assembled upside down and stacked during pallet loading in the inverted panel stack-up panelization process and that provides the predetermined orientation in the inverted pallet jig stack-up array as shown in FIG. 1 ;
[0027] FIG. 7 is fragmentary perspective view, with portions shown in cross-section, further illustrating the relationship of a PV panel and associated support rails with the jig lugs of FIG. 6 ;
[0028] FIG. 8 is a fragmentary perspective view of an uppermost layer in the panelization jig pallet stack-up illustrating installation of wiring and other electrical components to the uppermost inverted panelization layer during the panelization assembly process of FIG. 11 a employed in making the pallet jig stack-up of FIG. 1 ;
[0029] FIG. 9 is a fragmentary perspective view of a support block assembled at a defined position on a support rail which in turn is adhesively affixed to an underlying PV module while the same is upside down and in the uppermost exposed position in the panelization stack-up process;
[0030] FIG. 10 is a fragmentary perspective view of two registered support blocks and associated PV panels, with the blocks being shown in half-section in assembled relationship to one another and associated rails and PV glass panels during the panelization process;
[0031] FIGS. 11 a , 11 b , and 11 c are perspective semi-schematic views respectively showing successive panelization assembly steps of the bottom PV glass panel utilizing the pallet jig of FIG. 1 ;
[0032] FIG. 12 is a diagrammatic plan view of a PV solar panel panelization work center in accordance with the invention which illustrates material flow and labor stages in a factory-like environment, preferably located near the ground support rail racks field array installation, and the processing steps involved in preparing the PV solar panel modules oriented inverted and upside-down, or with their shady-side-up, or conversely, sunny-side-down, in the stack-up array of FIG. 1 ;
[0033] FIG. 13 is a perspective view of an assembled PV solar panel module, shown shady-side-up and by itself;
[0034] FIG. 14 is a perspective view of one system embodiment of solar panel modules having been delivered in a conventional sunny-side-up, non-jigged stack-up to the rack loading station by a forklift truck, and being manually placed on the rack loading station by a two-man crew;
[0035] FIG. 15 is a diagrammatic plan view illustrating an entire rail-rack-supported field array of solar panel PV modules as drone-populated from a central logistics area;
[0036] FIG. 16 is a perspective view of another embodiment of the step of successively individually robotically removing, and inverting to operable, or sunny-side-up, orientation, solar panel modules from two inverted, or sunny-side-down, stack-ups of finished solar panel modules, the stack-up in the foreground shown as being carried in an inverted module stack-up condition by a fork truck and in the forklift pallet jig assembly of FIG. 1 , and the other stack-up being shown in the background, as having already been transported to, and seated by the fork lift truck, as an entire palletized stack, on a rack-loading entry platform station. At this station, the PV modules are robotically unloaded as, and when, they individually become the uppermost exposed sunny-side-up module on the stack;
[0037] FIG. 17 is a perspective view showing the rack-loading station (shown uppermost in FIG. 16 ) wherein the automated hydraulic robot is shown holding a PV panel slightly beyond midway in the path of its transfer motion as the transfer robot is rotating the lifted panel about its longitudinal axis, and lowering it to bring it into upright orientation for disposition on the associated tilttable drone rack-loading station as shown in FIG. 16 ;
[0038] FIG. 18 is a perspective view showing a solar panel module supported on an associated operable computerized drone which is in turn movable on the ground-installed rail rack system in an operable embodiment of the invention;
[0039] FIG. 19 is a perspective view of a drone monitoring station constructed to record drone telemetry and provide a watch dog radio signal that, when halted, acts as an emergency stop to all robots operating at the site;
[0040] FIG. 20 is a perspective view of one embodiment of a solar panel array rack in accordance with the system of co-pending U.S. Ser. No. 13/553,795, as ground-installed;
[0041] FIG. 21 is a perspective view of one embodiment of an operable automated drone which is battery-powered and monitored by the drone monitoring station of FIG. 19 ;
[0042] FIG. 22 is a perspective view of the solar panel transfer robot (as also seen in FIGS. 16 and 17 ) illustrating the same entry at the approximate midpoint of the transfer stroke of the pick-up arm of the inverter-rack loader robot as shown in FIG. 17 , and also showing the tilttable drone loading station;
[0043] FIG. 23 is a perspective view, similar to FIG. 22 , showing a transfer robot with its panel transfer arm gripping the rails of an inverted PV solar panel assembly supported uppermost on solar panel stack-up 102 of FIG. 1 , and illustrating a portion of the associated pivotable end support posts unlatched and pivoted down and out of the way during the PV panel transfer operation;
[0044] FIG. 24 is a fragmentary perspective view showing the panel transfer robot carrying a solar panel downwardly in the tilt rack loading portion of its operational cycle, with the robot panel carrier arm having inverted the solar panel to upright orientation and while lowering the same to be supported on top of tilt rails of the robotic drone-loading station.
[0045] FIG. 25 is an isometric view of a stacking block 400 described in conjunction with FIGS. 9 and 10 , and referenced as 400 a and 400 b therein;
[0046] FIG. 26 is another isometric view of stacking block 400 oriented in a different direction than shown in FIG. 25 ;
[0047] FIG. 27 is a center cross-section view showing associated rails 312 a and 312 b facing the shady-side-surface 316 a and the sunny-side-surface 316 b of solar panel 316 as oriented in stack-up 102 of FIG. 1 ;
[0048] FIGS. 28 , 29 , 30 , 31 , 32 , 33 , 34 , and 35 shown in pairs comprising the even-numbered figures and the next consecutive odd-numbered figure, with illustrative spacer block configurations, the space block configuration of FIGS. 30 and 31 being presently preferred;
[0049] FIGS. 36 and 37 are fragmentary end and isometric views of a four panel stack-up using rails identical to those shown in FIG. 27 to respectively laterally space apart a vertical stack-up of spacer rails configured in cross-section the same as FIGS. 30 and 31 ;
[0050] FIGS. 38 and 39 are end elevational and perspective views, respectively, with the solar panels completed and oriented in a stack-up slightly modified from the stack-up of FIG. 1 ;
[0051] FIG. 40 is perspective assembly view of the robot transfer station having a stationary platform for receiving as input the palletized stack-up 102 , as shown in FIG. 16 , and also having an upright robotic tower provided with the pivotable panel carrier frame duly supported thereon and pivotally-actuated to swing the pick-up box arm through approximately 180° over the top of the robotic tower and to lower the panel, as a stack-up, onto the stationary receiving platform as shown by panel stack-up 102 b ( FIG. 16 );
[0052] FIG. 41 is a perspective view of the upright robotic tower equipped with two ram-actuated chain drives, one rigged for pivoting the gripper pick-up arm of the robot, and the other for raising and lowering the pick-up arm and associated carriage, up and down on the robot tower;
[0053] FIG. 42 is a perspective view of the box assembly of the pick-up arm shown in horizontal position by itself;
[0054] FIG. 43 is a semi-exploded perspective view of the hydraulic and chain drive components of the transfer and inverting ram as shown in detail in FIGS. 40 , 41 , 42 , and 43 ;
[0055] FIGS. 44 and 45 show the pivotal panel pick-up arm mechanism in a perspective assembly view of FIG. 44 and exploded in the perspective view of FIG. 45 , that rotates the oppositely extending pair of protruding drive shafts that non-rotatively are affixed to the pivoting arm that carries and pivots the pick-up arm;
[0056] FIG. 46 is a perspective view and FIG. 47 is partially exploded view of the tilting mechanism and framework for operably supporting the receiving channels 650 and 652 , and also the transfer and tilt station disposed between the upright robot mechanism and the input end of an associated rack row.
DETAILED DESCRIPTION
[0057] FIG. 1 is a perspective representation of a combined PV assembly jig and forklift transport pallet 100 , herein designated “pallet jig,” on which a stack-up 102 of PV modules 104 are individually jigged bottom-first and oriented upside-down relative to their operational orientation when mounted on a support rack in a solar panel array, such as the support rack shown on FIG. 18 . Components of pallet jig 100 are shown in greater detail in FIGS. 2 , 3 , and 4 . Pallet jig 100 is re-usable and serves as both a panelization jig in forming the inverted stack-up 102 of PV modules 104 and a transfer pallet that is removably engageable and supportable on the tines of a suitable forklift truck for transport to rack array panel loading stations in a field-installed solar panel array.
[0058] As best shown in the assembled views of FIGS. 1 and 2 , pallet jig 100 is made of robust steel pallet frame components, including laterally-spaced and longitudinally extruded box channel members, stringers 106 and 108 , open at their opposite longitudinal ends and designed to slidably receive a pair of fork tines of a commercially available forklift truck. As best seen in FIG. 2 , a pair of longitudinally spaced apart and parallel box frame members, cross beams 110 and 112 , are made up by a longitudinally-aligned array of open-ended shorter box section channels 114 , 116 , and 118 , registering with mating openings (not seen) in box beams 106 and likewise as to box beam 108 . The outer front and rear sides of the pallet construction are formed by C-section steel channels, such as front channel 120 seen in FIG. 2 , and on the opposite side of the pallet by C-section steel channels 122 , 124 , and 126 ( FIGS. 1 , 2 , and 4 ). The opposite longitudinal ends of the pallet framework are made up of C-section channels 130 , 132 , and 134 . C-section channel 130 is welded at its ends to the box section upright corner post 136 and at the other end to the side of stringer 106 adjacent its open end. Likewise C-section channel 132 is welded at its opposite longitudinal ends respectively to stringers 106 and 108 adjacent their open ends, and channel 134 is likewise welded to stringer 108 and upright corner post 140 .
[0059] Stringer beams 106 and 108 provide at each of their opposite longitudinal ends, a pair of rectangular-shaped openings 107 , 109 for receiving conjointly, respectively, the two conventional tines of a forklift mounted on the upright mast rails of a conventional forklift truck. Likewise, the opposite open ends of cross-beams 110 and 112 are designed to individually receive respective forklift tines of a conventional forklift truck (such as forklift truck 601 in FIG. 14 ).
[0060] The palletizing panel-locating function of pallet jig 100 is served by a series of upright channel posts disposed along the back of the opposite longitudinal ends of pallet jig 100 and along the rear side of pallet jig 100 . The upright channel posts are also clearly seen and described in connection with FIGS. 11 a , 11 b , and 11 c.
[0061] The primary jig post components, as shown in the aforementioned figures, include upright jig support and panel positioning posts arranged in pairs, illustratively, end support uprights 150 , 152 and 154 , 157 , one pair being located at each of the longitudinally opposite ends 105 and 115 of pallet jig 100 , along with corner support posts 158 a and 158 b . Pallet end support uprights 150 and 152 , for example, are both mounted at their bottom ends on a pivoting channel and sliding plate sub-assembly 170 shown separately in FIG. 3 . Sub-assembly 170 is a pivoting hinge beam that includes an inverted C-channel beam 171 , slide plate 172 and draw latch assemblies 190 and 192 .
[0062] As best seen in FIGS. 2 and 3 , pivoting channel and sliding plate subassembly comprises an inverted C-channel beam 171 provided with laterally spaced and longitudinally extending rows 174 and 176 of mounting bolt holes. Pivoting hinge beam 170 when upright rests on a centrally located slide plate 172 and is hingedly coupled thereto by a pair of hinges 178 and 180 ( FIGS. 2 and 3 ). Slide plate 172 has a pair of wheels 182 (only one wheel being seen in FIG. 3 ) rotatably mounted on down-turned side flanges 183 of slide plate 172 and tracking, in assembled condition, in associated wheel track channels 184 and 186 , respectively, affixed to the mutually-facing inner sides of longitudinal pallet channels, or box channel members, 108 and 106 as shown in FIG. 2 . Pivoting hinge beam 170 is releaseably held to the pallet in a fixed position by a pair of the adjustable draw latch assemblies 190 and 192 to thereby support and restrain associated jig posts 150 , 152 , and 158 fixed in predetermined upright orientation.
[0063] Draw latch assembly 190 is shown in detail in FIG. 4 . Referring to FIG. 4 , a locating and latch block and V-groove receiver sub-assembly 194 comprises an upright mounting plate 196 affixed by bolts 198 and 200 registered by associated mounting holes in the web of channel 120 . Mounting plate 196 has an upper extension 202 which supports mounting bolts 204 and 206 which thread into associated mounting holes in V-groove receiver 194 to securely affix the same to channel 120 . Locating block 194 has a front side facing pallet end channel 130 with a vertically-extending V-groove 210 therein that serves as the locating receiver for a cylindrical pin 212 in the latched position of associated latch 190 . Cylindrical locating pin 212 is welded to the outer face of the vertical flange 214 of pivot channel beam 170 and is drawn into seating engagement with the V-groove 210 of locating block 194 in the fully latched up condition of draw latch assembly 190 shown in FIG. 4 .
[0064] Each adjustable draw latch 190 and 192 , also comprises a U-shaped bracket member 220 having a pair of upright side flanges 222 and 224 held upright and spaced apart by an integral bottom web (not shown) that is welded to the upper surface of pivoting hinge beam 170 at the associated longitudinal end thereof. Adjustable draw latches 190 and 192 also include an inverted U-shaped latch receiver 226 having its center web welded to the upper face of locating block 194 . Latch receiver 226 serves as a receiver locking catch for cylindrical latch pin 230 . The upper edges of the upright sides of latch receiver 226 are configured to provide sliding support for cylindrical latch pin 230 in the latching and unlatching operating conditions thereof, and also to provide stop latch surfaces of semi-circular configuration to releaseably hold latch pin 230 in securely locked position when drawn thereagainst by swinging pivot handle 240 . Draw latch 190 includes a draw rod 232 that is externally threaded for threadably engaging an internally threaded through hole in latch pin 230 such that latch pin 230 , in unlatched condition, can be threadably adjusted along draw rod 232 . The end of draw rod 232 opposite pin 230 has a cross pin 234 that is pivotably mounted by being received in associated mounting holes in flanges 222 and 224 . Cross pin 234 thus serves as a pivot pin for draw rod 232 as well as a mounting pin for the pivot handle 240 of adjustable draw latch 190 .
[0065] Flanges 222 and 224 of latch assembly 190 have their upper edges configured to provide a draw cam action in cooperation with a cam follower bracket 242 ( FIG. 4 ). Follower bracket 242 has a horizontal cross piece 244 extending between and through associated slots provided in the pair of down-turned flanges of pivot handle 240 . The cam follower edges of cam follower latch bracket 242 are configured to slidably ride on down-sloping and latch-configured camming edges 246 of each mounting bracket 220 as to thereby function as a draw latch arm.
[0066] Draw latch assemblies 190 and 192 are fixedly mounted one each at the opposite longitudinal ends of pivoting hinge beam 170 as shown in FIGS. 1 to 3 . When latch assemblies 190 and 192 are unlatched by pivotably raising their associated latch operating arms 240 to thereby disengage latching pins 230 from locking brackets 226 . Inverted C-channel beam 171 , along with upright post supports 150 , 152 , and 158 a affixed upright thereon, can be pivoted outwardly about the rotational axis of the hinge pin connections 178 and 180 of channel beam 171 to slide plate 172 , thereby removing associated end support channels 150 and 152 as well as corner support post 158 from their upright edge-engagement with the associated panelized modules 104 by allowing the uprights to be pivoted down to rest on the ground. This release action frees up the panelized PV modules 104 and permits the panels to be removed more easily and safely from their position in the palletized stack-up.
[0067] Each of the pallet rear side support uprights and longitudinally opposite pallet end side support uprights, or jig posts, 150 , 152 , 158 , 155 , 156 , 158 b , 154 and 159 , is mounted in a selected position with respect to its associated horizontal support beam member of pallet jig 100 by an associated mounting gusset 260 as seen in FIG. 2 , only one of which will be described in detail. Gusset 260 comprises a U-shaped plate member having upright flanges 264 and 268 flanking its center web 265 . Gusset center web 265 is seated flat and bolted to an associated horizontal pallet frame member, which in this case is C-channel beam 171 of pivoting hinge beam 170 . Jig post 150 is selectively adjustably located longitudinally of pivoting hinge beam 170 by selecting the appropriate mounting bolt hole registry for a mounting bolt 262 having its head seated on the gusset center web 265 and its threaded shank extending through the selected bolt hole in the row of holes on C-channel beam 170 . The triangularly-shaped upright attachment flanges 264 and 266 of gusset 260 flank the opposite sides of the associated channel flanges of its associated upright jig post 150 and are welded thereto.
[0068] The two rear upright support posts 155 and 156 are likewise mounted to the pallet by associated gussets of like construction to gusset 260 and are likewise bolted in longitudinally adjustable positions by associated mounting bolts that extend one through the center web of the associated gusset. The gusset of each rear support posts 155 and 156 is bolted to the selected bolt hole in a row of bolt holes provided in a mounting channel 157 ( FIG. 2 ) fixedly and non-pivotally carried by associated pallet frame members at the rear side of pallet jig 100 .
[0069] Preferably, the pair of pivotal end support upright posts 150 and 152 , and likewise the pair of pivotal end support upright posts 154 and 157 that are located at the respectively associated opposite longitudinal ends of pallet jig 100 are provided with a pair of associated horizontal spreader bars 151 and 153 ( FIGS. 1 , 2 and 11 ). These spreader bars are in the form of C-channels wherein the center web, at opposite longitudinal ends of each spreader bar, are folded in and welded to the associated mutually facing sides of end support upright posts 150 and 152 , and likewise as to a pair of spreader bars 151 ′ and 153 ′ welded to end support upright posts 154 and 157 at the opposite longitudinal ends of pallet jig 100 .
[0070] Referring again to FIGS. 1 and 2 , and in more detail to FIGS. 6 and 7 , each of the upright posts 150 , 152 , 154 , 155 , 156 , 158 a , and 158 b is provided with an associated jig strip (best seen in FIGS. 2 and 11 and fragmentarily in FIGS. 6 and 7 ). Each of these jig strips is identified by the reference numeral of the associated upright support post as raised by a prime suffix, in FIGS. 1 , 2 , 6 , and 7 . Preferably, jig strips 150 ′ through 158 b ′ are machined to provide a one-piece finished part that is adhesively, or otherwise, securely affixed with its smooth backside against the inwardly facing surface of its respectively associated upright support post. As seen by way of example in FIGS. 6 and 7 , the surface of the base of jig strip 150 ′ that faces inwardly toward the panelization zone of pallet jig 100 is provided with protruding support and positioning projections, or lugs, 302 a and 302 b , arranged in a spaced apart vertical row and designed to position and support an associated PV panel rail in its proper position for the palletization process. Another vertical row of spaced apart lugs 300 a , 300 b , etc. are each positioned and designed to edge-support an associated PV panel during the panelization process, as described hereinafter, and with the panel edge supported at the desired height to insure uniform adhesive bead thickness.
[0071] The panelization process of the invention is best understood by viewing the assembly sequence shown in FIGS. 11 a , 11 b , and 11 c , in conjunction with the panelization work center material flow diagram of FIG. 12 , all to be read further in conjunction with the details in FIGS. 5-10 .
[0072] It should be understood that each PV solar panel module build-up starts with constructing a PV solar panel module, such as that shown in FIG. 13 , while its components are being sequentially supported on pallet jig 100 in an inverted, or upside down, relationship relative to their final operational orientation when later field-mounted on a rack of a solar panel array, illustratively of the type disclosed in co-pending U.S. Ser. No. 13/553,795, published on Jan. 24, 2013 as US-2013-0019925-A1.
[0073] Referring first to FIG. 13 , each panelized PV solar panel module includes, when completed, two parallel support rails 310 and 312 of identical construction that are adhesively affixed to, and transversely span, the downwardly facing bottom surfaces of two or more panels comprising a panel module. In this specific embodiment, three closely laterally-spaced coplanar PV panels 314 , 316 , and 318 are employed. PV solar panel module 103 is assembled in inverted condition (bottom-side-up) to form a jig-positioned, stack-up of such panels in forklift compatible pallet jig 100 .
[0074] Referring now to FIG. 5 , rails 310 and 312 are each preferably a thin gauge steel rail. Although it is to be understood that each rail 310 and 312 can be provided as a single flange or an I-beam section style, the hat section, double brim style channel configuration shown in FIG. 5 is presently preferred inasmuch as it provides better stability and section strength. Each rail 310 and 312 is adhesively affixed to, and spans a laterally-orientated, coplanar array of PV panels 314 , 316 , and 318 ( FIG. 13 ). Referring to FIG. 5 , each of the integral rail brim flanges 312 a and 312 b carry on their panel-facing sides a single adhesive bead 320 a and 320 b , respectively. The adhesive beads 320 a and 320 b are preferably formed of commercially-available adhesives, such as Dow Corning PV-8303 with the bead size being determined pursuant to the manufacturer's recommendation, just prior to installation in pallet jig 100 .
[0075] Referring to FIGS. 11 a , 11 b , 11 c , and 12 , adhesive beads 320 a and 320 b are first applied to the associated rail flanges 312 a and 312 b by specifically designed machinery 520 operable in panelization work center 500 as seen in the material flow diagram of FIG. 12 . By way of example, each adhesive bead 320 a and 320 b is preferably 3 mm thick and 9 mm wide in its cross-sectional dimensions as applied by machinery 520 .
[0076] Referring back to FIGS. 6 and 7 , for example, it is to be understood that the vertical row of rail-support and positioning lugs 302 a , 302 b , etc. are designed to hold the associated rail 312 , with the applied adhesive beads, with an appropriate contact pressure for the adhesive beads against the jig-oriented, upwardly-facing operable under-surface of the associated PV glass panel. Likewise the vertical row of panel support and positioning lugs 300 a , 300 b , etc. are vertically spaced apart and oriented to support the associated PV glass panel, resting thereon, at the desired height to assure uniform adhesive bead thickness.
[0077] In the embodiment shown in FIG. 7 , the rail support and positioning lugs 302 a , 302 b , etc. are designed to hold the associated rail 312 and 312 a , the appropriate distance above the associated PV glass and are dimensioned to have a relatively small clearance against the associated rail 312 and 312 a to keep the rail from twisting when assembled thereon in the final jigged position. The distance between rail holding jig lugs 302 a , 302 b is just sufficient to allow the next rail to slide in with a slight twisting motion.
[0078] Referring to FIG. 9 , a single stacking block 400 a is shown installed on associated rail 312 . Each stacking block can be formed as a one-piece plastic block that is machined or precision injection molded to the configuration shown in FIG. 9 and in cross section in FIG. 10 . All stacking blocks 400 , 400 a , 400 b , etc. in contact with a frameless PV glass panel, or module, are preferably made of plastic, illustratively urethane foam, or another relatively soft material, so as to minimize risk of damaging the PV glass of the module array.
[0079] FIG. 10 illustrates two identical stacking blocks, or spacers, 400 a and 400 b , in cross section, slidably received in vertical registry with one another on the hat section portions of associated rails 312 and 312 a . The stacking blocks are dimensioned so that the weight of the PV module stack-up 102 , as seen in FIG. 1 , is transmitted though the associated stacking blocks and rails so that no load support stress is placed on a PV glass layer in the panelization jig stack-up 102 . In addition, one or more spacers, suitably located between PV glass layers, may be required to maintain uniform thickness of the adhesive beads across the panel and to preserve the quality of the adhesive beads.
[0080] In FIG. 10 , two identical stacking blocks 400 a and 400 b are shown in assembled condition with associated rail 312 and 312 a , each block being shown in central half section. As shown in assembling step FIG. 11 c , four stacking blocks 400 a , etc. are c-rail installed at rail-block position numbered 406 , 408 , 410 and 412 per PV module, and as so installed, have a bottom tang portion 402 on their underside to ensure repeatable lateral spacing gaps between adjacent glass panels, such as panels 314 and 316 shown in FIG. 9 . Such spacing is particularly helpful in preventing damage to adjacent longitudinal solar panel edges as they flex and vibrate during truck lift transport described hereinafter. This is especially beneficial when dealing with “frameless” solar panel modules. each stacking block is provided with a notch 404 ( FIG. 9 ) to provide a gap between the stacking block and adjacent vertical side of the rail to thereby form a suitable passage way for accommodating the DC wiring loads installed in the stack-up assembly step of FIG. 11 a.
[0081] FIGS. 11 a , 11 b , and 11 c , diagrammatically and sequentially, illustrate the use of the PV assembly jig and forklift transport pallet 100 of the present invention to construct the stack-up 102 of inverted solar panels PV modules 104 as each is loaded upside-down (i.e., sunny-side-down) as shown in FIG. 1 . Preferably, the empty pallet jig 100 is provided as starting material for use in the panelization work center 500 shown diagrammatically in FIG. 12 . Preferably, work center 500 is established at a location spaced away from, but relatively close to, the site where the ground-supported array of solar panel racks is being constructed.
[0082] Panelization work center 500 is preferably a conventional, covered temporary construction-site-installed building (not shown) that provides relatively low cost protection against the weather, such as may be provided by a temporary quonset hut, or circus-tent type structure, so that the solar array construction equipment and materials can be securely, but temporarily stored therein, and solar panel construction labor can also be performed in the weather-protected environment so that such labor is eligible for the applicable factory labor rates which are significantly lower than the field labor rates of the relevant construction trades. Indoor construction conditions also reduce material damage and loss.
[0083] Referring further to diagrammatic FIGS. 11 a , 11 b , 11 c , in conjunction with FIG. 12 , note that, by way of example, panelization work station 500 is arranged with two parallel manual panelization assembly lines 510 and 512 mutually flanking a central rail prep line 516 . Rail prep line 516 preferably provides rail surface prep and adhesive bead application equipment to provide an indoor supply of rails with adhesive applied to the flanges, as described above, for manual installation in the flanking panelization assembly lines 510 and 512 .
[0084] Referring further to FIGS. 11 a , 11 b , and 11 c , in that sequence, FIG. 11 a shows the initial steps in constructing and pallet-assembling the bottommost solar panel module of a stack of such modules when forming the stack-up array 102 of inverted (i.e., sunny-side-down) modules seen in FIG. 1 .
[0085] In FIG. 11 a , three PV solar panels are shown installed side-by-side and so-oriented upside down and in a laterally-spaced array, ready for transport by fork lift truck, and removably supported in predetermined position by the associated solar panel support jig components of pallet jig 100 . More particularly, PV solar panel 314 , for example, is supported in horizontal orientation, bottom side up, on end support upright posts 150 and 152 by its panel edges resting on their associated jig lugs, such as lug 300 a , more clearly seen in FIG. 6 , which are provided on end support upright posts 150 and 152 . In this figure, pivoting end support upright posts 150 and 152 are shown locked to their vertical orientation by latches the associated pallet draw latch assemblies 190 and 192 . Likewise, the rear right-hand corner of panel 314 , as viewed in FIG. 11 a , is held horizontally-oriented while resting on its associated corner jig lug on upright corner support post 158 b.
[0086] The left-hand longitudinal edge of bottommost panel 314 rests on pallet frame channel sections 114 , 116 , and 118 ( FIG. 2 ) in lateral closely-spaced relation with the right hand longitudinal pallet edge of center panel 316 . Panel 316 in turn also rests on and is supported by pallet channels 114 , 116 , and 118 . The left-hand longitudinal edge of center panel 316 is closely spaced from the right-hand longitudinal edge of panel 318 , and those longitudinal edges are both supported on pallet channel 110 . The rear corner of panel 314 rests upon and is horizontally positioned by associated jig lug on upright corner support post 158 a.
[0087] The mutually-facing parallel longitudinal edges of panels 314 and 316 are closely spaced and held parallel to one another by their jig fixturing on pallet jig 100 . Likewise, the closely spaced mutually-facing parallel longitudinal edges of panels 316 and 318 rest on sectional pallet frame channel 110 . Panel 318 , at its rear left-hand corner, rests on on associated jig lugs on rear corner upright post 158 . The left-hand longitudinal edge of panel 318 rests on associated jig lugs on end support upright post 154 and 157 .
[0088] When PV solar panels 314 , 316 , and 318 are so-assembled and thereby releasably supported in a single layer so as to form the bottommost PV solar panel module 103 in stack-up array 102 ( FIG. 1 ), they are pallet jig oriented as PV module components located at predetermined x, y, and z, datum points, on and relevant to, associated support components of pallet 100 . Thus, the PV solar panel component of the bottommost layer of the pallet stack-up 102 ( FIGS. 1 and 2 ) is positioned at a predetermined x,y,z, location on pallet jig 100 , albeit in an upside down or inverted (sunny-side-down) condition relative to their final operational orientation (sunny-side-up) when finally operationally installed in a PV solar panel field array.
[0089] Referring again to FIG. 11 a , following manual installation of module support rails 310 and 312 , the next step in the assembly of pallet stack-up 102 is to install commercially-available panel DC wiring and wire management components, such as electrical components 502 a , 504 a , 506 a and 508 a , as partially shown in FIG. 8 . The majority of such DC wiring and wire management components are manually installed, with cable ties being used to manually dress the DC wiring, both intra-panel and inter-panel, to the underside surfaces of the three panel array 314 , 316 , and 31 . The manual labor installation work is greatly facilitated by the upwardly facing inverted orientation of the panels. However, the DC wiring must be restrained prior to the panel module being transported by the automated installation equipment as described hereinafter.
[0090] The next step in the construction of the solar panel module comprising PV panels 314 - 318 is shown in FIG. 11 b . Rails 310 and 312 are manually attached. Referring to FIG. 12 , adhesive beads 320 a and 320 b ( FIG. 5 ) are applied to the rails at the central adhesive dispensing station 520 in work center 500 . The panels are likewise oriented upside-down as manually assembled in their predetermined positions and orientation spanning panels 314 , 316 , and 318 , and with their associated adhesive beads 320 a and 320 b contacting the respectively upwardly facing bottom surfaces of inverted PV panels 314 , 316 , and 318 . Rails 310 and 312 are also inverted as installed and rest at their ends in the associated jig lugs as partially shown in FIGS. 6 and 7 .
[0091] Referring to FIG. 11 c , the next and last step in completing “in jig” the lowermost solar panel module assembly is to install the set of four removable stacking blocks 400 designated in FIG. 11 c as stacking blocks 406 , 408 , 410 , and 412 . Each of these blocks is identical to one another and to the installed stacking blocks 400 a and 400 b as shown in FIGS. 9 and 10 . Stacking blocks 406 and 410 are assembled on their respective rails 310 and 312 so that their bottom projections 402 a ( FIG. 9 ) fit in the gap between the mutually facing longitudinal edges of panels 316 and 318 . Likewise, stacking blocks 408 and 412 have their bottom projections 402 a disposed the gap between the mutually facing longitudinal edges of panels 314 and 316 . Stacking blocks 408 and 412 are removably seated on associated rails 310 and 312 such that their bottom protrusions 402 a likewise defines the gap between the longitudinally extending and mutually facing edges of panels 316 and 314 . The x, y, z datum in the dimensions of the stacking blocks are predetermined by the associated pallet jig and positioning lug orientations provided for the single bottom layer assembly of FIG. 11 c . The stacking blocks also provide a gap to control the vertical distance between the associated rails 310 and 312 and the back of the associated panel, i.e., the thickness of the adhesive beads 320 a and 320 b , as shown in FIG. 5 .
[0092] The solar module positioning and assembly steps described above in conjunction with FIGS. 11 a , 11 b , and 11 c , complete the bottommost layer of the PV module stack-up 102 of FIG. 1 . Note that the x,y,z datum points for this module assembly are predetermined relative to the features of the pallet jig 100 as described hereinabove in conjunction with FIGS. 1-10 . The sequential steps of the assembly cycle of FIGS. 11 a , 11 b , and 11 c are repeated with respect to constructing and assembling the next solar assembly module as superimposed sunny side down on top of the bottommost module 103 . These steps further include installing removable and reusable slip-fit stacking blocks 406 , 418 , 410 , and 412 , accurately positioned and located on their associated rails 310 , 312 , for serving their final operative use as damage prevention to the panel stack-up 102 during lift truck delivery to the field array of solar panels.
[0093] Referring specifically to panelization work center 500 shown diagrammatically in the flow diagram of FIG. 12 . Work center 500 is made large enough to prepare the completed PV assembly jig and forklift transport pallets, shown in FIG. 1 as pallet jig 110 , and by way of example, may comprise at least two assembly lines 510 and 512 Empty pallet jigs 100 and 100 ′ are returned from their field-emptying cycle and fed as recycling starting input to assembly lines 510 and 512 shown schematically in FIG. 12 .
[0094] Preferably work center 500 is constructed as a temporary warehouse or portable factory, to provide a weather-protected covered and firm surface work platform, such as a concrete floor pad represented diagrammatically as pad 514 in FIG. 12 . Hence, the manually-performed assembly steps in the construction of pallet jigged stack-ups 102 of inverted solar panel modules 104 is efficiently completed by manual labor and production equipment that are sheltered in panelization work center 500 . In FIG. 12 , a series of empty pallet jigs 100 are shown entering assembly line row 510 , and empty pallet jigs 110 ′ are shown entering the duplicate assembly line row 512 . The two assembly lines 510 and 512 are spaced apart to accommodate central processing line 516 for surface preparation and application of adhesive to support rails 310 and 312 for sequential assembly as described herein to each layer of PV modules 104 in the jig pallets 100 , 100 ′, and so on, as provided to assembly lines 510 and 512 .
[0095] The central rail supply line 516 of workstation 500 includes a rail surface preparatory station 518 and a centrally located adhesive dispensing station 520 that receives the output of panel rails upstream from surface prep station 518 and applies the adhesive beads 320 a and 320 b to the rail hat brim flanges 312 a , and 312 b , described in conjunction with FIG. 5 . In the embodiment shown, central adhesive dispensing station 520 has two sets 520 a and 520 b of three duplicate output stages arrayed one set on each of the longitudinal sides of dispensing station 520 to thereby provide the appropriate output of rails from the central station 520 with adhesive beads applied to the rail hat flanges. The rails are manually retrieved from central station output and assembled with and affixedly applied to the upwardly facing bottom surface of inverted PV panels in the manner described in conjunction with FIG. 11 b.
[0096] The pallet-jig PV panel assembly stations 520 , 522 , 524 and 526 , 528 , 530 provided respectively in each of the panelization assembly lines 510 and 512 complete a palletized and jig-oriented respective stack-up 102 ( FIG. 1 ) for fork lift transport. The assembly steps of FIGS. 11 a , 11 b , and 11 c are repetitively performed on and in each of the pallet jigs 100 , as shown diagrammatically in FIG. 12 by the right-angle assembly arrows 519 , 522 , and 524 of assembly line 512 , and likewise diagrammatically shown by the right angle assembly arrows 526 , 528 , and 530 and assembly line 510 . These completely assembled PV module stack-ups 102 are then fork lift truck transported from the final stage of assembly lines 510 and 512 to an input queue at a covered adhesive curing station (not shown). Thus, the assemblies are protected from weather, and also if needed, simultaneously heated to assist curing of the adhesive beads and consequent adhesion of the rails to the associated PV module panels.
[0097] Referring to FIG. 15 , using a system such as that disclosed in co-pending U.S. Ser. No. 13/553,795, entire PV solar panel rail rack arrays 602 and 603 can be populated from a central logistics area. Typically, this area will be a permanent service or fire access road 600 as seen in FIG. 15 and which is already included in the site plan as shown diagrammatically in the solar panel rail rack arrays 602 and 603 . Aisle breaks 604 and 606 in the arrays 603 and 602 , respectively, can be bridged with temporary rails indicated schematically at 608 , thereby extending the solar panel field area that is reachable from a single logistics area for installation of the PV solar panels by automated drones 902 , as described and shown in the aforementioned co-pending patent application.
[0098] FIG. 14 illustrates a stack-up 610 of PV solar panel modules 611 oriented sunny-side-up and unrestrained while being delivered by fork lift truck 601 and manually off-loaded to provide a ground-supported stack 610 of panels 611 in accordance with the prior art. Also in accordance with the prior art, after having been delivered by a fork lift truck, the individual solar panels 611 are manually off-loaded from the ground-supported stack-up 610 and then individually carried manually, or by specially-equipped rough terrain trucks, between adjacent rack rows until reaching their final individual operational position on the support rack.
[0099] FIG. 14 also illustrates a stack-up 610 of solar panel PV modules oriented right-side up in stack 610 in accordance with the prior art, and to be manually lifted and placed one at a time by a two man installation team on drone-equipped support rails of a system constructed in accordance with the aforementioned co-pending application. This drone-equipped rack array system, in conjunction with the PV assembly jig and forklift transport pallet of the present invention, can save hundreds of hours of service time in constructing solar panel arrays, as well as the time and cost of staging modules around the array field, and the subsequent trash retrieval cost. By using the railed rack arrays and automated robotic drones to carrying and place PV solar panels on the racks to form the solar panel array, a small team of people can install a megawatt (MW) of solar panels per day, approximately 20 times faster than an equivalent number of laborers manually installing PV solar panel modules in accordance with the prior art. The system of the invention can thus eliminate 95% of the automated PV panel carrier labor costs of installing PV solar panels.
[0100] FIG. 16 is a perspective overhead view that shows, by way of two side-by-side parallel field delivery and assembly lines, sequential stages in automated unloading and inverting of upside-down solar panels to a sunny side up orientation from panelization stack assemblies at panel unloading and transfer stations, each feeding PV panels to a given entry location of an associated dual rail rack support made in accordance with the invention. A stack-up load 102 a of solar panel modules constructed and assembled on a pallet jig 100 a , in the manner described previously herein in conjunction with FIGS. 1-12 , is shown in FIG. 16 being carried on fork tines of a forklift truck 103 for deposit of the pallet-jigged load stack-up 102 a onto the channel-type ground-mounted stationary load-receiving platform 612 a . The accurate predetermined positioning of a pallet jig 100 a on receiving platform 612 a is designed to stationarily position stack-up 102 a at fixed and predetermined x, y, z geographic datum points relative to operational engagement, transfer and release datum points of an associated robotic transfer station mechanism 614 positioned between platform 612 a and the associated end-loading point of an associated rack rail installation 616 .
[0101] FIG. 16 illustrates a neighboring palletized jig stack-up 102 b , which is provided in a manner similar to stack-up 102 a . Stack-up 102 a is better seen in FIG. 17 after the same has been accurately deposited on, and supported by, an associated stationary support rack 612 b constructed and positioned in the manner of support station 612 a ( FIG. 16 ). The stack-up 102 b is also accurately positioned for cooperation with the associated robotic inverter/transfer station 618 a that in turn is operably positioned relative to the feed-in end of the associated rail rack 620 a and 620 b.
[0102] FIGS. 22 , 23 , and 24 , as well as the opposite side view in FIG. 17 , illustrate the structure and operation of the robotic solar panel load inverter/transfer mechanism of transfer station 618 and of the duplicate mechanism of neighboring transfer station 614 as seen in FIG. 16 . Transfer stations 618 and 614 each include an automated, hydraulically-actuated robotic carriage tower 622 shown stationarily mounted on channel framework platform 624 that in turn is secured at its entrance end to the associated ground supported loading platform 612 b . Transfer robot tower 622 supports a combined hydraulic and chain-drive, computer controlled drive carriage 626 that is raised and lowered on an interior track of tower 622 . Carriage 626 is located on the side of tower 622 facing oncoming PV solar panel load array stack-up 102 b . Carriage 626 also pivotally supports a transfer carriage pivot arm assembly 628 see, as pivoted almost upright in FIG. 22 .
[0103] Transfer carriage pivot arm 628 comprises a rectangular hollow beam box frame construction provided, as best shown in Figures * and *, with two sets of hydraulically-actuated panel rail grippers 529 , located one pair each on the hollow longitudinally extending box frame carriage side member 630 and 632 that are in turn joined at their longitudinally opposite ends by carriage cross frame members 634 and 636 ( FIG. 22 ). A pair of laterally-spaced transfer carriage support arms 640 are affixed at their outer ends to the closet crossbar 636 of carriage arm 628 . Gripper support arms 640 straddle carriage 626 and, at their lower ends, are pivotally supported on carriage 626 . Gripper actuating hydraulic lines 641 are trained from carriage 626 via hollow arms 640 and into the hollow side arms 632 and 634 of gripper 629 .
[0104] Each of the solar panel transfer stations 614 and 618 also includes a tilttable platform station mechanism located between its associated robot transfer tower 622 and the loading/unloading ends of the associated dual rack rails of solar panel support racks. As best seen in FIGS. 22 and 23 , platform tilt mechanism 624 is made up of a laterally-spaced apart pair of parallel Z-section channel rail platform members 650 and 652 . Tilt platform rails 650 and 652 are carried on the upper ends of a rocker framework *** of generally U-shaped configuration. Rocker platform frame arms *** and *** ( FIGS. 22 and 23 ) carry platform rail members 640 and 642 , normally horizontal, mounted to and spanning the upper ends of frame arms 656 and 658 .
[0105] The entire platform framework 650 is rockingly supported by a pair of upright U-shaped stanchion-rocker arm assemblies, located at and supported midpoints of stationary rocker platform 624 . Each stanchion assembly comprises a stationary arm fixed at its lower section frame 624 and rotatably carrying, at its upper end, one end of a pivot rod 662 journalled therethrough. A companion rocker support gusset member 664 is rockingly carried supported faced inwardly of fixed gusset support member 660 . Pivot rod 662 , passes through support member 664 , but is non-rotatively affixed to its upper end. The lower end of the stationary support arm 664 is fixed to the center of the associated rocker U-frame member 652 so as to rockingly carry the same on, and in response to, rotation of pivot rod 662 for rocking travel, through a travel arc angle sufficient to orient the solar panel receiving plane mutually defined by platform rails 650 , 652 , i.e., tilt platform rails from a horizontal solar panel receiving attitude (shown in FIGS. 22 and 23 ) to a tilted panel transfer attitude wherein platform rails 650 and 652 are respectively lined up in registry with associated station rack rails 620 a and 620 b.
[0106] The pivot rocking actuation of rocking carriage 650 is obtained by computer-controlled operation of a hydraulic ram 670 ( FIG. 23 ) pivotally mounted at its lower cylinder end, and thereby affixed, to stationary frame 624 . The piston rod 671 of ram 670 is pivotally connected at its upper end to the swingable crank arm 672 . In turn, crank arm 672 is connected at its upper end to the protruding other end of pivot rod 662 and non-rotatively coupled thereto for actuating pivot rod 662 , and thus swinging support arm 664 through the aforementioned working range of rocker support frame 650 in response to automated hydraulic control.
[0107] In the operation of the respective transfer stations 614 and 618 , the respectively associated transfer carriage receiving platform rails 640 and 642 are automatically controlled and hydraulically actuated to pivot through a working arc starting from a horizontal solar panel pick-up attitude, wherein transfer carriage arm 628 has been lowered to lay flat on the exposed panel rails 310 and 312 affixed to whatever inverted solar panel module is oriented upside down and exposed as the uppermost inverted solar panel such as solar panel module 104 as shown in FIG. 23 .
[0108] When transfer gripper arm mechanism 628 is so-oriented, the grippers carried by its transport arms 630 and 632 are actuated to cause the grippers to firmly engage the exposed panel rails 310 and 312 . The transfer robot 618 is then actuated, by its computer control system, to first carry the uppermost inverted panel assembly module vertically upwardly as carriage 626 is elevated along tower 622 . The robot 618 thus initially carries the gripped module with a generally horizontal attitude until robot carriage 626 is approaching the upper limit of its vertical travel on tower 622 . The robot then causes carriage 626 to be pivoted upwardly to thereby swing the supported panel 90 to clear over the top of tower 622 while thereby also inverting the panel from its inverted horizontal stack orientation bottom face up to pivoting the panel to fully upright vertical orientation, and thus, completing the first 90° of the load pivoting motion as the carriage 618 travels upright over the upper end of tower 622 . The fully upright vertical orientation of carriage 626 can be seen in FIG. 22 while traveling empty over tower 622 on its return travel path and where it will complete the second 90° pivoting motion to load-pickup horizontal orientation, as seen in FIG. 1 , and is then fully inverted to bring the PV module assembly with the glass panels facing upright, as shown in FIGS. 16 and 17 , as support carriage 628 is traveling down tower 622 with rails of the solar panel load firmly engaged by the grippers of carriage 628 , and having been pivoted to a horizontal attitude as shown in FIG. 24 .
[0109] In the rail racks panel loading phase of operation of the hydraulically-actuated robot tower 622 , the robot drives carriage arm assembly 628 downwardly to an off-load carriage position where panel rails 310 and 312 extend across and rest upon the uppermost flanges of transfer Z-section channels 640 and 642 of tilt mechanism 618 . Solar panel assembly 104 is oriented horizontally and extends over the ends of transfer channels 640 and 642 , closest to, rails 620 a and 620 b that in turn are disposed in an angled plane closely spaced to the ends of rack rails 620 a and 620 b , as shown In FIGS. 22 and 23 . As the carriage arm assembly 628 travels through the space between tilt platform rails 640 and 642 of the tilting carriage when disposed in a horizontal plane. The solar panel assembly module rails 130 and 132 engage and rest upon the horizontal flanges of tilt support rails 640 and 642 . The carriage arm assembly 628 then continues its downward travel so as to be clear of tilt platform support channels 650 and 652 until the carriage reaches its lowermost stop position where the carriage components are disposed within the confines of the pivoting frame 650 in non-interfering relation therewith.
[0110] The pivotal panel support mechanism of tilt frame 650 is then actuated to cause the solar panel to bodily pivot about the axis of pivot rod 652 so as to bring the solar panel into the tilted attitude matching the tilt of rack rails 620 a and 620 b relative to each other and with the mutually inwardly facing flanges 644 and 646 tilt-aligned with the inwardly extending flanges of rack rails 620 a and 620 b . This enables the remote-controlled drone 902 with its super-posed panel rail gripping mechanism 910 to be lowered into its lowermost position on the drone, and then the drone 902 to be actuated to travel with its opposite side wheels running on associated flanges 644 and 646 of transfer rails 640 and 642 so that the rails of drone lift mechanism 910 touch the panel assembly module rails 310 and 312 resting on the upper flanges of platform channels 640 and 642 . The lift mechanism of drone 902 is then actuated to elevate and engage the panel assembly module rails 310 and 312 and elevate them upwardly off of transfer platform rails 640 and 642 and carry the tilted panel supported on carriage 910 of drone 902 with the solar panel tilted to match the tilted orientation of the rack rails 620 a and 620 b to match their tilt angle for drone-supported travel on the rails to bring the solar panel being carried on the drone 902 in tilted orientation and spaced above the rails 620 a and 620 b until the drone-supported solar panel reaches its installation location on the dual rail support rack shown as installed and ground-mounted in FIG. 20 , as described in the aforementioned co-pending patent application.
[0111] Drone monitoring station 700 , shown in FIG. 19 , is constructed to record drone telemetry and provide a watch dog radio signal that, when halted, acts as an emergency stop to all robots operating at the site. “Once operation is initiated, both the autoloader and the drones worked autonomously.
[0112] Referring in more detail to FIGS. 25-47 , and supplementing the photographic views of the structure of operable embodiments of various structural features shown in FIGS. 13 , 14 , 16 , 18 , 19 , 21 - 24 , a successful working embodiments of the system, method, and apparatus of the present invention.
[0113] Referring first to construction and use of the space blocks shown in FIGS. 25-37 , in conjunction with the perspective drawing views provided in FIG. 5 through 10 and FIG. 11 c , assembly and use of the spacer blocks are shown in FIGS. 9 , 10 , and 27 . Referring to FIGS. 25 and 26 , spacer block 400 is preferably accurately machined, die-cast, or injection-molded, such that its longitudinal bottom projection 402 a enters into the gap formed between the mating, or opposed longitudinal edges, of an associated pair of solar panels as shown in FIG. 9 . This helps the accurate positioning of solar panel rails relative to the associated solar panels, and also helps to protect the longitudinal side edges of an adjacent pair of solar panels.
[0114] Spacer blocks 400 have a transverse U-shaped channel of constant cross-sectional configuration extending all the way through and open at the ends of the spacer block. These channels are defined by accurately spaced apart, and parallel, side surfaces 405 and 406 , that are designed to have a close slip fit as the space block is aligned with an associated rail end and slidably pushed down to seated position with the crown and adjacent parallel sides of the rail fitting nicely within groove 403 .
[0115] The slip fit installation and removal characteristic of the spacer blocks relative to the associated solar panel rails helps maintain the rail assembly accurately in the panel jig 100 but does hinder the separation of the spacer blocks from their associated panel rails when the panel is being inverted and installed on the associated field support rack.
[0116] Spacer block 400 , as well as the remaining variations thereof in FIGS. 28-35 , have basically been described previously in connection with FIG. 11 c.
[0117] Referring to the structure, function, and operation, of the “flipper” station for transferring solar panels one at a time from the platform loading station to the rails of the field rack solar panel array, is best seen in FIGS. 40-47 , and will be described hereinafter with respect to these figures.
[0118] Referring first to the assembly view of FIG. 40 , the load-receiving platform 612 a , as seen ground-mounted, at the front end of station 618 . The base of robot tower 622 is mounted on a channel framework attached to the rear of platform 612 a . The carriage 626 has upright channel member 700 of channel configuration carrying on each side a pair of vertically-spaced rollers removably supporting the carriage on the cooperative frame walls of tower 622 . A vertically-extending ram has the lower end of its cylinder fixed to the base of the tower and the upper end of its pistons carrying a sprocket on which a carriage-elevating chain is trained with one run extending stationarily down to a fixed point at the base of the train as seen in FIG. 41 , and the other trained around a sprocket at the upper end of the carriage as seen in FIG. 43 .
[0119] As seen in FIG. 44 , the gripper arm pivoting motion is provided by a chain 720 looped over two sprockets 722 and 722 ′ (only one sprocket being shown in the figure), each fixed to a shaft 724 and 724 ′ extending through a pair of bearings 722 and 726 . The inner ends of lift-arm carriage are non-rotatively affixed to the rotary shaft 724 . The chain loop 720 is fixedly coupled to the upper end of the piston of ram 726 that is used to produce the pivoting motion of the grip arm assembly. The ram 726 , through chain 720 , causes the pivot rod 724 to rotate, and thereby causing the pivoting motion of the gripper arms while the same travel up and down with the carriage, the vertical motion being produced by vertical travel of the carriage. Thus, the compound motion of the pivot arms, namely the vertical motion of the carriage carrying the pivot arms bodily up and down. The carriage arms can be independently pivoted by the pivot shaft whose pivoting rotary drive is carried with the carriage as it is being moved vertically by the ram.
[0120] It is also to be noted that the rigging arrangement for the vertical actuation of the carriage is rigged to produce a 2:1 distance.
[0121] The solar panel stack unloading work, wherein each solar panel module is lifted off its uppermost position on the multiple panel stack-up on the pallet jig at the input station to the inverter station is shown in the discussion of FIGS. 16 , 22 , 23 , 24 , 44 , and 45 . The tilt station mechanism is best seen in the perspective assembly view of FIG. 26 , taken in conjunction with the exploded perspective view of FIG. 47 . This is supplemental to the previous discussion of the tilting and transferring PV panel station comparable for individually-loading drone-mounting solar panels one-at-a-time onto the rail racks described previously.
[0122] From the foregoing description in conjunction with the appended drawings, as well as the description, drawings, and claims of co-pending patent application U.S. Ser. No. 13/553,795 and underlying provisional application U.S. Ser. No. 61/804,620 filed on Mar. 22, 2013, incorporated herein by reference, it will be understood that the system, apparatus, and method of PV power plant construction provides improved results, benefits, and advantages over the prior art apparatus and systems for installing and equipping PV power plant construction. By automating the requisite processes of assembling, transporting and positioning the thousands of PV panels required for large-scale projects, the system of the invention enables megawatt-per-day panel installation rates with just a small construction crew. Moreover, this automation is achieved with no additional installation materials.
[0123] Although the invention has been described in terms of specific embodiments and applications, persons skilled in the art can, in light of this teaching, generate additional embodiments without exceeding the scope or departing from the spirit of the claimed invention. Accordingly, it is to be understood that the drawing and description in this disclosure are proffered to facilitate comprehension of the invention, and should not be construed to limit the scope thereof. Moreover, the technical effects and technical problems in the specification are exemplary and are not limiting. The embodiments described in the specification may have other technical effects and can solve other technical problems. | 4y
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[0001] This application is a division of co-pending application Ser. No. 10/385,857, filed on Mar. 12, 2003, which claims the benefit of Japanese application no. 2002-067086, filed on Mar. 12, 2002.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a production method of cellulose film in which cellulose film is produced by preparing a polymer solution through dissolving cellulose ester in a solvent containing a prescribed organic solvent as the main component, forming a filmy object from the prepared polymer solution, and evaporating the solvent in the filmy object, and a cellulose film thus produced; and protective film for polarizing plate, optical functional film, polarizing plate, and liquid crystal displays produced by the above described production method of cellulose film.
[0004] 2. Description of the Related Art
[0005] Conventionally, cellulose film is used as optical materials for optical functional films for use in widening the viewing angle and preventing glare; protective films for the polarizing plates in liquid crystal displays; and the like. The cellulose films used for such optical materials are produced by means of the solution method for forming film. In the solution method for forming film, a filmy object is formed from a polymer solution in which cellulose ester or the like is dissolved in an organic solvent, the filmy object formed is heated to evaporate the organic solvent in the filmy object, and a polymer film is thereby obtained. In this connection, when the organic solvent remains in the produced cellulose film, there occur adverse effects on the dimensional stability of the film, or the coloring of the film is degraded. Accordingly, the control of the residual amount of the organic solvent in the produced cellulose film has heretofore been performed from the viewpoint of the quality. The produced cellulose film is subjected to saponification and the like in post-processes, and subsequently is commercialized as optical functional film, or protective film for polarizing plate.
[0006] Now, when the cellulose film produced by the solution method for forming film is considered from the standpoint of the environment conservation, nowadays considered to be important, there is concern that, with the level of the residual amount of the organic solvent as controlled from the viewpoint of the quality, a slight amount of the organic solvent is evaporated from the produced film in the post-processes subsequent to the film production.
[0007] However, as for the residual amount of the organic solvent, investigation has hitherto been performed from the viewpoint of the quality, but no investigation has been performed from the viewpoint of the environment conservation, and hence it is not clear how far the level of the residual amount of the organic solvent should be lowered so that the effects on the environment substantially vanish.
[0008] Additionally, in order to reduce the residual amount of the organic solvent, the following treatments are suggested: the heating period of time is extended in the evaporation process, the heating temperature is raised, and the amount of the organic solvent is reduced in relation to the amount of cellulose ester. However, in the current solution method for forming film, the production efficiency is improved while the quality of the film being maintained at a high level, and hence a variety of measures are adopted for shortening the time required for the evaporation process as much as possible; these measures include the following measures in which the amount of the organic solvent is decreased to a level as low as possible in relation to the amount of cellulose ester, and the heating temperature is raised to a level below which cellulose ester is not thermally decomposed. Consequently, it is anticipated that not only the quality of the film is degraded, but also the production efficiency is remarkably degraded, owing to extending of the heating time in the evaporation process, raising the heating temperature, and reducing the amount of the organic solvent in relation to the amount of cellulose ester, for the purpose of reducing the residual amount of the organic solvent.
SUMMARY OF THE INVENTION
[0009] The present invention, in view of the above circumstances, takes as its object the provision of a production method of cellulose film which can reduce the residual amount of the organic solvent, without degrading the film quality, and with degrading the production efficiency to the least possible extent; a cellulose film which substantially has little effects on the environment due to the residual organic solvent; and protective film for polarizing plate, optical functional film, polarizing plate, and a liquid crystal display produced by the above described production method of cellulose film.
[0010] The production method of cellulose film of the present invention, which achieves the above described object, is a production method of cellulose film which method produces cellulose film by preparing a polymer solution through dissolving cellulose ester in a solvent having a prescribed organic solvent as the main component, forming a filmy object from the prepared polymer solution, and evaporating the solvent in the filmy object; and wherein:
[0011] the polymer solution is prepared by adding a poor solvent, having the highest boiling point among the materials contained in the solvent, so as to have the content of 0.1 to 1.0 wt % where the total amount of the solvent in the prepared polymer solution is taken as 100 wt %; and
[0012] the solubility of cellulose ester in the poor solvent is inferior to the solubility of cellulose ester in the organic solvent which is the main component of the solvent.
[0013] The addition amount of the poor solvent is very small, so that the addition of the poor solvent scarcely degrades the production efficiency of the cellulose film. Additionally, since the poor solvent is highest in boiling point among the materials contained in the solvent, it is most difficult to be evaporated and tends to remain. Furthermore, since the solubility of cellulose ester in the poor solvent is inferior to the solubility of cellulose ester in the organic solvent which is the main component of the solvent, the intermolecular bond between the poor solvent and the cellulose ester is difficult to be formed as compared to the intermolecular bond between the main-component organic solvent and the cellulose ester. In the solvent during the evaporation process, the action of the remaining poor solvent prevents the formation of the intermolecular bond between the main-component organic solvent and cellulose ester, and the evaporation of the main-component organic solvent is thereby promoted. Additionally, the remaining poor solvent hardly forms the intermolecular bond with cellulose ester so that cellulose ester is scarcely restrained by cellulose ester, and the addition amount of the poor solvent is very small; hence the poor solvent is evaporated at the end of the evaporation process, and the added poor solvent does not affect the film characteristics.
[0014] Additionally, in the production method of cellulose film of the present invention, the main-component organic solvent is dichloromethane, and it is preferable that the polymer solution is prepared by adding an alcohol having one to two carbon atoms in addition to the poor solvent.
[0015] The compatibility of dichloromethane with cellulose ester is satisfactory, and hence adoption of dichloromethane as the main component of the solvent leads to reduction of the total amount of the solvent in relation to the amount of cellulose ester. Additionally, addition of alcohols having 1 to 2 carbon atoms improves the dimensional stability (self-supporting property) of the filmy object, making the transportation of the film-like material be convenient.
[0016] Furthermore, in the production method of cellulose film of the present invention, taking the total amount of the solvent in the prepared polymer solution to be 100 wt %, it is preferable to prepare the polymer solution in such a way that dichloromethane is added in a content of 70 to 99 wt %, and simultaneously an alcohol having 1 to 2 carbon atoms is added in a content of 0.9 to 29.0 wt %.
[0017] Additionally, in the production method of cellulose film of the present invention, it is preferable that the poor solvent is an alcohol having the boiling point in the range from 80 to 170° C.
[0018] The boiling point of dichloromethane, the main solvent component of the solvent, is about 40° C.; accordingly, when the boiling point of the added alcohol is 80° C. or above, the alcohol remains in the solvent during the evaporation process, preventing without fail the intermolecular bonding formation of dichloromethane with cellulose ester. On the other hand, when the boiling point of the added alcohol is chosen to be 170° C. or below, the alcohol can be evaporated in the final stage of the evaporation process without causing the thermal decomposition of cellulose ester.
[0019] In this connection, in the production method of cellulose film of the present invention, when the mixing of the poor solvent is performed in an in-line mode, a static mixer may be used in the piping for addition and mixing; or
[0020] at least two or more kinds of polymer solutions maybe subjected to simultaneous flow casting or successive flow casting.
[0021] Additionally, in the production method of cellulose film of the present invention, it is also preferable that the polymer solution of cellulose ester film has the solid content ranging from 15 to 30 wt %.
[0022] Additionally, in the production method of cellulose film of the present invention, it is also preferable that the material containing the cellulose acetate synthesized from wood pulp as the main component is used as cellulose ester.
[0023] As cellulose ester, the cellulose acetate synthesized from cotton linter is known, in addition to the cellulose acetate synthesized from wood pulp; however, adoption of the cellulose acetate synthesized from wood pulp as the main component makes it possible to reduce the costs for cellulose film.
[0024] Additionally, in the production method of cellulose film of the present invention, it is preferable that the film is made to be swollen and then dried on the way of the drying process thereof, or after drying, during the film formation process by flow casting of the polymer solution of cellulose ester.
[0025] As above, through swelling once the filmy object, while the solvent being evaporated from the filmy object, or after the solvent has been evaporated, even when the molecules composing the solvent form the intermolecular bond with cellulose ester, the intermolecular bond can be broken; namely, the evaporation of the solvent can be further promoted by swelling once the filmy object and then evaporating the solvent therein again.
[0026] In this connection, it is preferable that for the purpose of swelling once the film (filmy object), the film may be swollen with water, a solvent may be applied onto the film, or exposure to a solvent gas may be performed. Incidentally, it is preferable that an alcohol-based substance (for example, an alcohol having 1 to 2 carbon atoms, etc.) is used as the solvent to be applied and the solvent gas.
[0027] The cellulose film of the present invention, which achieves the object of the present invention, is characterized in that, in the form of the finished film product, the residual amount of dichloromethane is 0.1 wt % or less, and additionally the total residual amount of the solvent is 0.5 wt % or less.
[0028] By controlling the residual amount of dichloromethane, and the total residual amount of the solvent to the values as specified above, the effects on the environment of the residual solvent in the cellulose film having been produced can be substantially prevented.
[0029] The protective film for polarizing plate, optical functional film, polarizing plate, and liquid crystal displays, which achieve the object of the present invention, are characterized in that each thereof is produced by use of the production method of cellulose film of the present invention, or by use of the cellulose film of the present invention.
[0030] As above, the present invention can provide the production method of cellulose film in which the residual amount of the organic solvent in the film can be reduced, without degrading the film quality and with degrading the production efficiency to a least possible extent; the cellulose film which gives the substantially vanishing effects of the residual solvent on the environment; and the protective film for polarizing plate, optical functional film, polarizing plate, and a liquid crystal display, all produced by the aforementioned production method of cellulose film.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a simplified schematic view of the production line while the cellulose film is being produced by flow casting of the polymer solution onto a round cylindrical drum; and
[0032] FIG. 2 is a simplified schematic view of the production line while the cellulose film is being produced by flow casting of the polymer solution onto an endless belt.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0033] Description will be made below on the embodiments of the present invention.
[0034] In the embodiments of the production method of cellulose film of the present invention, the cellulose film is produced by flow casting of a polymer solution onto a supporting body. The supporting bodies onto which the flow casting of the polymer solution is performed include the following two bodies, a round cylindrical drum and an endless belt. Now, with reference to FIG. 1 , description is made on the production line wherein a cellulose film is produced by the flow casting of the polymer solution onto the round cylindrical drum.
[0035] FIG. 1 is a simplified schematic view of the production line while the cellulose film is being produced by flow casting of the polymer solution onto a round cylindrical drum.
[0036] The production line 1 shown in FIG. 1 is one embodiment of the production method of cellulose film of the present invention, namely, a production line of TAC (triacetyl cellulose) film; from the upstream side of the production line 1 in order, there are arranged a polymer solution preparation apparatus 100 , a flow casting die 200 , a flow casting drum 300 , and a peeling roll 400 .
[0037] In the production line 1 , there are arranged three polymer solution preparation apparatuses 100 , each preparing a different type of polymer solution. Here, as an example, description will be made on the polymer solution preparation apparatus 100 shown on the right in FIG. 1 . The polymer solution preparation apparatus 100 prepares the polymer solution of triacetyl cellulose. In preparation of the polymer solution, triacetyl cellulose is dissolved in a solvent containing dichloromethane as the main component, and a small amount of n-butanol is added to the solution in which triacetyl cellulose is dissolved. n-Butanol is higher in boiling point than dichloromethane. Additionally, the solubility of triacetyl cellulose in n-butanol is inferior to the solubility of triacetyl cellulose in dichloromethane. The polymer solution preparation apparatus 100 comprises a storage tank 110 , a liquid delivery pump 120 , a poor solvent supply device 130 , a static mixer 140 , and a filter 150 . In the storage tank 110 , a mixed solution CM of dichloromethane and methanol wherein triacetyl cellulose is dissolved is stored while being stirred by stirring blades 111 . The solution CM stored in the storage tank 110 is delivered to a flow casting die 200 by the liquid delivery pump 120 ; the static mixer 140 and the filter 150 are arranged in some midway points along the liquid delivery path. Additionally, the poor solvent supply device 130 supplies n-butanol B to the static mixer 140 under favor of a liquid delivery pump 131 . In the static mixer 140 , n-butanol B is added to and mixed with the mixed solution CM. The addition amount of n-butanol is so small that the adding and mixing of n-butanol little degrades the production efficiency of the TAC film. Incidentally, instead of using the poor solvent supply device 130 , n-butanol may be added to and mixed in the storage tank 110 . The filter 150 removes, from the solution delivered from the static mixer 140 , foreign objects, undissolved raw materials, etc., and then the solution is delivered to a flow casting die 200 .
[0038] In the flow casting die 200 , the polymer solutions prepared respectively in the three polymer solution preparation apparatuses 100 are supplied. More specifically, from the polymer solution preparation apparatus 100 depicted at the right of FIG. 1 , of the three polymer solution preparation apparatuses, the polymer solution constituting the film surface layer is delivered; from the polymer solution preparation apparatus 100 depicted at the center, the polymer solution constituting the film central part is delivered; and from the polymer solution preparation apparatus 100 depicted on the left, the polymer solution constituting the film back surface layer is delivered. The respective delivered polymer solutions are discharged from the outlet of the flow casting die 200 . Incidentally, the number of the polymer solution preparation apparatuses 100 is not necessarily limited to 3, but it may be one, two, or more than three depending on the specification of the produced cellulose film.
[0039] The flow casting drum 300 is revolved along the direction of the arrow A. The flow casting die 200 is arranged above the flow casting drum 300 in such a way that the outlet faces onto the circumferential surface of the flow casting drum 300 .
[0040] The respective polymer solutions discharged from the outlet of the flow casting die 200 are subjected to simultaneous flow casting onto the circumferential surface of the flow casting drum 300 rotating along the direction of the arrow A. The polymer solutions discharged onto the circumferential surface of the flow casting drum 300 , during about three-quarter revolution along the direction of the arrow A, is water-cooled from the inside of the flow casting drum 300 and simultaneously air-cooled from the outside by blasting cooling air, and accordingly the gelation is promoted to form a filmy object having self-supporting property.
[0041] Subsequently, the filmy object reaches the position, where a peeling roll 400 is installed, to be peeled off.
[0042] A winding device 500 is arranged at the downstream end of the production line 1 shown in FIG. 1 . A soft film drying zone 11 and a late stage drying zone 12 are arranged between the peeling roll 400 and the winding roll 500 , both zones being the zones where the solvent in the filmy object is evaporated. Furthermore, a swelling device 600 is arranged between the soft film drying zone 11 and the late stage drying zone 12 . The filmy object peeled off by the peeling roll 400 is delivered by two driving rolls along the direction of the arrow B, via the soft film drying zone 11 →the swelling device 600 →the late stage drying zone 12 , and wound by the winding roll 500 .
[0043] A tenter 700 is arranged in the soft film drying zone 11 . The filmy object peeled off by the peeling roll 400 is delivered to the soft film drying zone 11 , and passes through the interior of the tenter 700 . Inside the tenter 700 , the filmy object is heated, the solvent contained in the filmy object is further evaporated. The filmy object discharged from the tenter 700 is delivered to the swelling device 600 . A swelling device is a device in which the filmy object delivered thereto is once made to be swollen; the swelling device 600 in FIG. 1 is a device where the solvent gas composed of ethanol is sprayed onto the filmy object being delivered. Incidentally, instead of ethanol, alcohols such as methanol and water vapor may be sprayed. The filmy object discharged from the swelling device 600 is delivered to the late stage drying zone 12 . Plural rolls 800 are arranged in the late stage drying zone 12 , and the filmy object is delivered while being wrapped around the plural rolls 800 . The filmy object is heated in the upstream section 12 a of the late stage drying device 12 , and the solvent remaining in the filmy object is evaporated.
[0044] As for the n-butanol added to and mixed in the polymer solution preparation apparatus 100 , it is most resistant to evaporation and tends to remain in the solvent, since n-butanol is highest in boiling point among the materials contained in the solvent. Additionally, since the solubility of triacetyl cellulose in n-butanol is inferior to the solubility of triacetyl cellulose in dichloromethane, it is more difficult to form the intermolecular bond of n-butanol with triacetyl cellulose than the intermolecular bond of dichloromethane with triacetyl cellulose. In the solvent having been added and mixed with n-butanol, the action of n-butanol breaks the intermolecular bond between dichloromethane and triacetyl cellulose, promoting the evaporation of dichloromethane. Additionally, since the remaining n-butanol does not tend to form intermolecular bond with triacetyl cellulose, it does not tend to be engaged to triacetyl cellulose, and its addition amount is small, it is evaporated by the time when the filmy object has passed the upstream section 12 a of the late stage drying zone 12 , so that the added n-butanol does not affect adversely the characteristics of the film. Furthermore, since in the production line 1 , the solvent in the filmy object is once evaporated in the soft film drying zone 11 and is subsequently swollen by the swelling device 600 , even the intermolecular bond between dichloromethane and triacetyl cellulose which remains unbroken by n-butanol can be broken. Then, in the upstream section 12 a of the late stage drying zone 12 , the solvents remaining in the filmy object, such as the dichloromethane broken out of triacetyl cellulose by the swelling action, is evaporated. Consequently, in the production line 1 , the evaporation of the solvent in the filmy object is promoted, and the remaining amount of dichloromethane in the filmy object having passed the delivery zone 12 can be reduced to be 0.1 wt % or less, and simultaneously the total residual amount of the solvent is also reduced to be 0.5 wt % or less.
[0045] In the downstream section 12 b of the late stage drying zone 12 , the filmy object is cooled down to room temperature, and the filmy object (TAC film) takes the form of the finished TAC film product. The filmy object (TAC film) discharged from the late stage drying zone 12 is wound by the winding device 500 . The TAC film thus produced is subsequently delivered to the subsequent processes, unshown in the figure, and is commercialized as the optical functional films such as protective film for polarizing plate and anti-glare film. Additionally, polarizing plate is formed by attaching the protective film for polarizing plate onto both sides of a polarization element made of polyvinyl alcohol etc.; and a part of a liquid crystal display is made by using the polarizing plate.
[0046] Now, with reference to FIG. 2 , description will be made below on the production line wherein cellulose film is produced by flow casting of the polymer solution onto an endless belt.
[0047] FIG. 2 is a simplified schematic view of the production line while the cellulose film is being produced by flow casting of the polymer solution onto an endless belt.
[0048] The production line 2 shown in FIG. 2 is the TAC (triacetyl cellulose) film production line which is an embodiment of the production method of cellulose film of the present invention, as the production line 1 shown in FIG. 1 , wherein a flow casting band 900 is arranged instead of the flow casting drum 300 arranged in the production line 1 shown in FIG. 1 . With the same reference numerals for the same constituent elements as those of the production line 1 in FIG. 1 , description is made below with a focus on the points different from those in the production line 1 shown in FIG. 1 .
[0049] In the production line 2 shown in FIG. 2 , the three same polymer solution preparation apparatuses 100 as the three polymer solution preparation apparatuses shown in FIG. 1 , and three flow casting dies 200 are arranged. The three polymer solution preparation apparatuses 100 are respectively connected to the three flow casting dies 200 in a one-to-one relation. Additionally, the three flow casting dies 200 , flow casting band 900 , and peeling roll 400 are arranged in a drying chamber 10 .
[0050] The flow casting band 900 is formed by wrapping an endless belt 930 around a driving drum 910 and a driven drum 920 . The belt 930 displaces circularly along the direction of the arrow C in the drying chamber 10 . The three flow casting dies 200 are arranged along the running direction of the belt 930 and above the belt 930 , with the die outlets facing onto the surface of the belt 930 .
[0051] The polymer solutions delivered to the respective flow casting dies 200 are successively subjected to flow casting onto the surface of the belt 930 circularly running along the direction of the arrow C, the solvent is gradually evaporated while the belt 930 is circularly running in the drying chamber 10 , and becomes a film to yield the self-supporting property. Namely, the evaporation of the solvent leads to a filmy object having shape stability. After the belt 930 has finished about one round, the filmy object is peeled off by the peeling roll 400 , and delivered to the soft film drying zone 11 .
[0052] In the soft film delivery zone 11 of the production line 2 shown in FIG. 2 , plural rolls are arranged; the filmy object going into the soft film drying zone 11 is delivered along the direction of the arrow D, by being guided by the plural rolls. The swelling device 600 is arranged in a midway position in the soft film delivery zone 11 . Incidentally, the swelling device 600 may be arranged in a midway position in the upstream section 12 a of the late stage drying zone 12 . The swelling device 600 shown in FIG. 2 is different from the swelling device shown in FIG. 1 in that the filmy object being delivered is water soaked and rinsed with water. Incidentally, the application of an alcohol such as ethanol may replace the watersoaking. Both in the upstream section and in the downstream section of the swelling device 600 of the soft film drying zone 11 , dry air is blasted onto the filmy object being delivered, resulting in evaporation of the solvent in the filmy object. In the upstream section 12 a of the late stage drying zone 12 , next to the soft film delivery zone 11 , the filmy object is heated, and the solvent remaining in the filmy object is evaporated. Additionally, in the downstream section 12 b of the late stage drying zone 12 , the filmy object is cooled down nearly to room temperature, to take a form of the finished TAC film product. The filmy object (TAC film) discharged from the late stage drying zone 12 is wound by the winding device 500 .
[0053] Now, detailed description is made below on the preparation of the polymer solution. In the polymer solution preparation performed in the polymer solution preparation apparatuses 100 as shown in FIGS. 1 and 2 , at the beginning, triacetyl cellulose grains are dissolved in an organic solvent having dichloromethane as the main component, in the storage tank 110 . The triacetyl cellulose is a mixture of those synthesized from wood pulp and cotton linter, wherein the content of that synthesized from wood pulp is 60 wt % and the rest of 40 wt % is allotted to that synthesized from cotton linter. As above, making that synthesized from wood pulp be the main component can reduce the cost for the TAC film. Incidentally, that synthesized from cotton linter may be completely excluded to make the whole comprise only that synthesized from wood pulp.
[0054] The compatibility between the dichloromethane and triacetyl cellulose is satisfactory, and hence adopting dichloromethane as the main component of the organic solvent leads to the reduction of the total amount of the solvent in relation to the amount of triacetyl cellulose. Additionally, the organic solvent in the storage tank 110 contains methanol as a component of the mixed solvent. The addition of methanol leads to the improvement of the shape stability (self-supporting property) of the filmy object peeled off by the peeling roll 400 , and the easiness in transporting the filmy object. The composition ratio between the dichloromethane and methanol is so adjusted in the storage tank 110 that dichloromethane is contained in the content of from 70 wt % to 99 wt %, and methanol is contained in the content of from 0.9 wt % to 29.0 wt %, taking the total amount of the solvent in the polymer solution prepared in the polymer solution preparation apparatus 100 to be 100 wt %. Incidentally, ethanol may replace methanol, or water may be added with modified composition ratio of methanol. Furthermore, in the organic solvent in the storage tank 110 , a plasticizer, an ultra violet light absorber, an anti-deterioration agent, etc. are dissolved as additives. In the storage tank 110 , the solid content such as triacetyl cellulose and the additives is adjusted so as to be from 15 to 30 wt %, taking the amount of the polymer solution prepared in the polymer solution preparation apparatus 100 to be 100 wt %. n-Butanol, a poor solvent, is so added that the content thereof falls in the range from 0.1 wt % to 1.0 wt %, taking the amount of the polymer solution prepared in the polymer solution preparation apparatus 100 to be 100 wt %. Incidentally, as a poor solvent, any alcohol having the boiling point in the range from 80 to 1700, other than n-butanol, may be used. The boiling point of dichloromethane is about 40° C.; accordingly, when the boiling point of the poor solvent is 80° C. or higher, the poor solvent remains in the solvent during evaporation of the solvent, and the intermolecular bonding of dichloromethane to triacetyly cellulose is prevented without fail. On the other hand, when the boiling point of the poor solvent is 170° C. or lower, the poor solvent can be evaporated without thermally decomposing triacetyl cellulose.
[0055] As a result of the preparation described above, the solvent of the polymer solution delivered to the flow casting die 200 is composed of dichloromethane and n-butanol. Additionally, the composition ratios thereof are such that the content of dichloromethane ranges from 70 wt % to 99 wt %, the content of methanol ranges from 0.9 wt % to 29.0 wt %, and the content of n-butanol ranges from 0.1 wt % to 1.0 wt %, talking the total amount of the solvent to be 100 wt %.
[0056] Incidentally, until this point, description has been made on the production method of TAC film using the polymer solution in which triacetyl cellulose is dissolved in the solvent containing dichloromethane as the main component; however, in the production method of cellulose film of the present invention, the main solvent component may be an organic solvent such as lower fatty alcohols, and a chloride of a lower fatty hydrocarbon other than dichloromethane. Additionally, the solute may be a cellulose ester other than triacetyl cellulose. Furthermore, the added poor solvent is not limited to n-butanol, but it may be any solvent which is highest in boiling point among the materials contained in the solvent of the prepared polymer solution, and is inferior in the solubility of cellulose ester to the organic solvent which is the main component of the solvent.
EXAMPLES
[0057] Description will be made below on the TAC film production by applying the production method of cellulose film of the present invention, and the performed measurement of the residual amounts of the organic solvents, together with the comparative examples.
[0058] At the beginning, example 1 produced the TAC film by using the production line 1 shown in FIG. 1 . In the preparation of the polymer solution, the triacetyl cellulose synthesized from cotton linter was not mixed; the triacetyl cellulose synthesized from wood pulp (20 parts by weight), a plasticizer (2.2 parts by weight), and an ultraviolet light absorber (0.02 parts by weight) were used; and the solvent was prepared so as to give the composition ratios specified below, for which the polymer solution prepared by the polymer solution preparation apparatus 100 was taken to be 100 wt %. Additionally, in the swelling device 600 , a solvent gas composed of nitrogen gas and added methanol (methanol:nitrogen=2:8) was sprayed onto the filmy object discharged from the soft film drying zone 11 , thereby swelling once the filmy object.
(Example 1)
[0000]
Dichloromethane: 79.6 wt %
Methanol: 19.9 wt %
n-Butanol: 0.5 wt %
[0062] Additionally, in examples 2 to 4, the TAC films were produced under the same conditions as those in example 1, except that the conditions under which the filmy object discharged from the soft film drying zone 11 was once swollen, was changed to each condition specified below. In other words, the composition ratios of the polymer solutions were the same as those in example 1.
(Example 2)
[0000] Application of a Solvent (Methanol:Water=1:1) in 0.5 cc/m 2 .
(Example 3)
[0000] Spray of Water Vapor at 120° C.
(Example 4)
[0000] Rinsing with Water by Watersoaking.
[0063] Furthermore, in example 5, the TAC film was produced under the same conditions (the composition ratios of the polymer solution, etc.) as those in example 1, except that the filmy object discharged from the soft film drying zone 11 was not once swollen.
(Example 5)
[0064] Between the soft film drying zone 11 and the late stage drying zone 12 shown in FIG. 1 , the filmy object was not once swollen, and the filmy object discharged from the soft film drying zone 11 as delivered to the late stage drying zone 12 , thereby performing the continuous drying.
[0065] Additionally, furthermore, in respective examples 6 and 7 and comparative examples 1 and 2, the TAC films were produced under the same conditions as those in example 5, except that the solvent composition ratios of the polymer solution were changed as the respective conditions specified below. In other words, in the same manner as that in Example 5, the filmy object discharged from the soft film drying zone 11 was not once swollen.
(Example 6)
[0000]
Dichloromethane: 99.0 wt %
Methanol: 0.9 wt %
n-Butanol: 0.1 wt %
(Example 7)
[0000]
Dichloromethane: 70.0 wt %
Methanol: 29.0 wt %
n-Butanol: 1.0 wt %
(Comparative Example 1)
[0000]
Dichloromethane: 79.6 wt %
Methanol: 20.31 wt %
n-Butanol: 0.09 wt %
(Comparative Example 2)
[0000]
Dichloromethane: 79.6 wt %
Methanol: 19.29 wt %
n-Butanol: 1.01 wt %
[0078] On the TAC films produced in respective examples 1 to 7 and comparative examples 1 and 2, described above, the total residual amount of the organic solvent, the residual amount of dichloromethane, and the residual amount of n-butanol were respectively measured by gas chromatography, and the results as shown in Table 1 were obtained.
TABLE 1 Total Residual amount Residual residual of amount amount dichloromethane of n-butanol (wt %) (wt %) (wt %) Example 1 0.34 0.03 0.31 [0.5 Wt %, Solvent gas] Example 2 0.34 0.03 0.31 [0.5 Wt %, Solvent application] Example 3 0.35 0.04 0.31 [0.5 Wt %, Water vapor] Example 4 0.35 0.04 0.31 [0.5 Wt %, Watersoaking] Example 5 0.37 0.05 0.32 [0.5 Wt %, No swelling] Example 6 0.18 0.09 0.09 [0.1 Wt %, No swelling] Example 7 0.48 0.04 0.44 [1.0 Wt %, No swelling] Comparative Example 1 0.45 0.11 0.34 [0.09 Wt %, No swelling] Comparative Example 2 0.51 0.03 0.48 [1.01 Wt %, No swelling]
[0079] Table 1 shows the total residual amount (wt %) of the organic solvent, the residual amount of dichloromethane (wt %), and the residual amount of n-butanol (wt %), in a single horizontal row, for each example or each comparative example. These three residual amounts are the residual amounts in the TAC film immediately after having been discharged from the late stage drying zone 12 .
[0080] The present inventors discovered, as a result of diligent research, that in order to substantially reduce the effects on the environment ascribable to the solvent remaining in the TAC film after production, in the form of the finished TAC film product, the residual amount of dichloromethane is required to be 0.1 wt % or less, and additionally the total residual amount of the organic solvent is required to be 0.5 wt % or less. From the results shown in Table 1, for the TAC film produced in any of examples 1 to 7, the residual amount of dichloromethane is 0.1 wt % or less, and additionally the total residual amount of the organic solvent is 0.5 wt % or less. Accordingly, in the TAC film produced in any of examples, the effects of the residual solvent on the environment can substantially be suppressed. However, in the TAC film produced in comparative example 1, wherein the content of n-butanol is 0.09 wt %, the total residual amount of the organic solvent is 0.5 wt % or less, but the residual amount of dichloromethane takes a slightly higher value of 0.11 wt %. On the contrary to comparative example 1, in the TAC film produced in comparative example 2, wherein the content of n-butanol is 1.01 wt %, the residual amount of dichloromethane is 0.1 wt % or less, but the total residual amount of the organic solvent takes a slightly higher value of 0.51 wt %. As can be seen from these results, in order to produce the cellulose film which substantially vanishes the effects of the residual solvent on the environment, n-butanol has only to be added in the content range from 0.10 wt % to 1.00 wt % in the preparation process of the polymer solution, taking the total amount of the solvent in the prepared polymer solution to be 100 wt %. Turning to a comparison of example 1 with example 5, both examples being the same in the addition amount of n-butanol, the residual amount of dichloromethane remaining in the TAC film is larger in example 5 than in example 1. Such a matter is also the case in comparison of any example of examples 2 to 4 with example 5. As can be seen from these results, by swelling once the filmy object between the soft film drying zone 11 and the late stage drying zone 12 , the evaporation of dichloromethane in the late stage drying zone 12 is promoted. A comparison of examples 1 and 2 with examples 3 and 4 indicates that the evaporation of dichloromethane is more promoted by swelling the filmy object with a solvent than with water. Incidentally, the peeling off operation with the peeling roll was able to be more rapidly performed in the production of the TAC film in any example than in the production of the TAC film in any comparative example. | 4y
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