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FIELD OF THE INVENTION
This invention relates to hydrogen-selective membrane walls for connecting the high pressure chamber to the low pressure chamber of apparatus for the preparation of pure hydrogen at elevated temperatures.
BACKGROUND OF THE INVENTION
The prior art is replete with descriptions of palladium-bearing alloy membranes used to prepare pure hydrogen from gaseous hydrogen-containing mixtures by permeation through a palladium-bearing metallic membrane under pressure and at elevated temperatures. Reference is made to the co-pending patent application Ser. No. 08/719,385 of common assignee which is incorporated herein by reference. Wherein an important advantage of a 60% palladium-40% copper alloy membrane with respect to temperature-cycling and minimal swelling in hydrogen is disclosed. This bears also on the publication by J. Shu, B. P. Grandjean, A. van Neste and S. Kaliaguine, entitled "Catalytic Palladium-based Membrane Reactors: A Review", The Canadian Journal of Chemical Engineering, Vol. 69, (October, 1991), herein also incorporated by reference, wherein this particular palladium-copper alloy is described as showing a sharp maximum at 40 wt % Cu.
Accordingly, for the purpose of the present invention, we use such palladium copper alloys with copper contents sufficiently near the 40% by weight optimum, (i.e. 36-42% Cu), in which narrow range more than two thirds of the maximum flux is retained. Such alloys are termed "Pd/40% Cu" in this specification and the appended claims.
As shown, for example, in the above referenced co-pending application, Pd alloy membranes can be in the form of thin flat foils or small diameter tubes (e.g. 2 mm O.D.). Foils of the Pd/40% Cu membrane are readily available in thicknesses of 0.001 to 0.0025 inches, whereas special expensive techniques a re required to make such Pd/40% Cu tubes with wall thicknesses of no less than 0.0025 inch.
As also disclosed in the above-referenced co-pending application, a palladium alloy foil can be sandwiched between gaskets, and the edge area of the sandwich can be pressed onto a metallic frame. To so produce a leak-tight two-chamber apparatus, a uniform weighty and costly edge pressure is required to at least balance the pressure in the high pressure chamber. It is thus important to replace, in a pure hydrogen generator, the gasket seal with a pressure-tight seal, such as a weld. Welding is preferred over brazing or soldering to avoid contamination of the foil by the extraneous metals of the latter.
Diffusion welding employs temperatures that range from 50 to 75% of the melting point "Procedure Development and Practice Considerations for Diffusion Welding", by S. B. Dunkerton, "ASM Handbook", vol. 6, p. 883, ASM International (1993)!. Diffusion welding of copper to a different metal or to an alloy "is conducted at a temperature greater than one-half of the absolute melting point" Diffusion welding of Solid-State Welding, by J. L. Jellison and F. J. Zanner, "Metals Handbook", 9th Ed. Vol. 6, p. 672, ASM International (1983); see first column on page 672 and Table 1 on page 677!.
The Pd/40% Cu alloy has a melting point of approximately 1200° C. (1473K) "ASM Handbook", vol. 3, p. 717, ASM International (1993)!. Hence welding it to copper is expected to require a temperature in excess of about 460° C. (733K). However, we have found that the hydrogen flux across the Pd/40% Cu foil deteriorates after the foil has been exposed to such high temperatures.
Underlying the present invention is the discovery that these problems can be overcome by providing a hydrogen selective Pd/40% Cu membrane wall in the form of a thin palladium-copper alloy membrane of carefully controlled composition in an open-area copper-surfaced metallic frame, hermetically bonded by diffusion-bonding the membrane to the frame.
The term "diffusion-bonding", as used herein means controlling and maintaining an elevated bonding temperature below about 350° C., while subjecting the edge area of the membrane in contact with the frame to a substantially uniform high pressure, in an oxygen-free atmosphere.
OBJECTS OF THE INVENTION
One object of this invention is to provide a novel, much lower-temperature, diffusion-bonding technique of Pd/40% Cu to copper which avoids flux deterioration, as well as the need for excessive edge gasket compression.
Another object of this invention is a new and improved pure hydrogen-permeating membrane wall having a Pd/40% Cu foil hermetically bonded by such technique to a copper surface on a temperature and pressure-resistant, herein termed "firm", metallic frame.
Other and further objects will be explained hereinafter and are more fully delineated in the appended claims.
SUMMARY OF THE INVENTION
In summary, from one of it's viewpoints, this invention broadly embraces an assembly comprising a thin Pd/40% Cu foil having its edge area diffusion-bonded to a copper-surfaced metallic frame. The term "copper surface" as used in this specification and in the appended claims means a copper coating as well as a copper-rich alloy coating of sufficient copper content for diffusion-bonding.
The novel diffusion-bonding technique of this invention comprises the step of pressing a thin Pd/40% Cu foil, preferably 0.001-0.0025 inches thick, onto a copper-surfaced frame, after exposure to or, preferably, in a hydrogen-containing atmosphere, in the range of 200° to 350° C. and more particularly between 290° and 325° C., for example, for a cycle period of several hours in a hydrogen atmosphere furnace.
The novel wall of this invention comprises a polished firm metallic frame made of carbon steel or stainless steels or others, an adherent, preferably electroplated, copper surface thereon, and a thin Pd/40% Cu membrane foil having its edge area hermetically sealed to the copper surface by the above novel diffusion-bonding technique.
Preferred and best mode designs and techniques are later presented.
DESCRIPTION OF THE DRAWING
The invention will now be described in connection with the accompanying drawing, the single FIGURE of which is a schematic top view of a metal frame having its open area covered by a Pd/40% Cu foil with the foil edge area diffusion-bonded to the frame, in accordance with the invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
We propose, as above stated, to take advantage of the availability and of the low cost (relative to tubes) of a thin Pd/40% Cu foil membrane by diffusion-bonding it hermetically to a frame to form a wall which, in a pure hydrogen generator, obviates gasketing and the excessive mechanical pressure required therefore.
Surprisingly, we have found that a Pd/40% Cu foil can be diffusion-bonded to copper under pressure and, after exposure to and, preferably in the presence of hydrogen, even when the temperature is in the low range of 200° to 350° C., and preferably between 290° and 325° C. While we do not wish to be held to any theory, it is believable that the bond results, at least in part, from copper inter-metallic diffusion and that the hydrogen exposure eliminates any interfering oxide layer.
This mode of diffusion-bonding has been found not to be deleterious to the membrane, as evidenced by its durability, at the very same temperatures, when pure hydrogen is generated from a methanol-steam reformate, as described in the above-referred to co-pending patent application.
By way of example, referring now to the FIGURE of the drawing, samples of Alloy 101 (i.e. oxygen-free) copper frames 1, each 1.5 inches square and 0.03125 inch thick, were center punched each with a 0.625 inch diameter hole. Pd/40% Cu foils 3, each 0.001 inch thick and 1 inch diameter, were centered over the 0.625 inch diameter holes of the frames 1. The 0.1875 inch overlap edge perimeters 2 of each of the foils 3 were mechanically held under pressure by a pair of opposing flanges (not shown). The pressure was controlled by the torque load on the four flange bolts (also not shown).
After evenly tightening the flange bolts, the assemblies were loaded into a controlled atmosphere furnace for heat-treating. The furnace temperatures were varied between 200° and 350° C. with a slow flow of pure hydrogen gas through the furnace, which was held at atmospheric pressure, or alternatively under reduced pressure, for about twelve hours.
The hermetic seals between the foils and the frames produced by the diffusion bonds were tested by subjecting the finished assemblies in a separate apparatus (also not shown) to a pressure gradient of helium gas of up to 150 psi for several hours. No gas leakage was observed.
When selecting a temperature range between 290° and 325° C. and flowing hydrogen at about atmospheric or reduced pressure, a mechanical perimeter pressure in the order of 5000 psi or more resulted in producing hermetic seals between the frame and foil.
Bonding periods in the furnace vary with operating conditions. The required times for hermetic sealing are readily determined experimentally by selecting and controlling the temperature, edge pressure and either the pre-hydrogen exposure at an elevated temperature and/or the hydrogen atmosphere in the furnace, and then leak-testing the resultant assembly.
As the wall separating the high and low pressure chambers of a pure hydrogen generator, the diffusion-bonded assemblies of this invention must withstand the pressure differential at the elevated operating temperature. The above-described, 100% copper framed, diffusion-bonded assemblies deformed badly under gas pressure above about 200° C. However, operation of such diffusion bonded assemblies below about 200° C. is undesirable due to poor hydrogen permeability.
Hence, for the purpose of this invention, we use a structurally firm frame made of a metal or an alloy subject to copper coating, which is not weakened under the operating temperatures and pressures of a pure hydrogen generator, such as carbon steel, stainless steels, or others, which, when not subject to copper coating, do not lend themselves to diffusion-bonding.
We have found that diffusion-bonding, as herein described, of a Pd/40% Cu foil to a copper-coating plated onto such a firm metallic frame, results in an assembly, in which, surprisingly, the bond of the copper coating to the frame metal and the bond of the Pd/40% Cu foil to the copper coating, are both strong.
But, in leak tests of these assemblies, helium leaks were sometimes encountered. Though again we do not wish to be held to any theory, we have found it plausible to attribute the helium leaks either to the grainy streaks of the somewhat uneven surface of the metal frame, (which streaks were actually showing through the foil's edge area of the finished assembly) and/or to too thin a copper plate (such as less than 0.0005 inch thick).
Thus, to obtain consistent hermetic seals for the use of the assemblies in two-chamber hydrogen generators, we select thicker copper coatings and/or we polish the frame metal to provide a smooth even area prior to plating copper and diffusion-bonding Pd/40% Cu thereon. These samples were leakproof in the helium leak test.
As a specific example of producing such a leak proof assembly, samples of a commercial grade "oil hardening" pre-ground flat stock carbon steel were prepared in the above-described dimensions. Prior to copper plating, they were polished to a smooth finish, some by hand and others by electropolishing, cleaned by degreasing and pickled. Some samples were also subjected to a short electrolytic "nickel strike" to assure good copper adhesion.
The samples were then electroplated from standard, e.g. cyanide or sulfate, baths to copper coating thicknesses of about 0.0005 to 0.0008 inch.
Diffusion-bonding of 0.001 inch thick Pd/40% Cu foils to the copper plated frames was then performed as above-described.
While preferred embodiments of the invention have been described in the foregoing, it will be apparent to those skilled in the art that they can be varied without departing from the scope of the invention. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
Jewelry clasps are known wherein longitudinal, end-alined bodies are connected by a tongue projecting from one body into the other body and releasably engaged, as by friction, therein. In such known jewelry clasps, difficulty is often encountered in maintaining the tongue against accidental release and escape with consequent disengagement of the clasp and possible resultant loss of the jewelry. Additionally, in some instances, the clasp structure--obviously necessarily small--was difficult to assemble, may not have been sufficiently sturdy and hence subject to wear and tear, or could not be readily manipulated for engaging or disengaging the clasp. The present invention was conceived in a successful effort to provide a jewelry clasp which avoids such undesirable factors.
2. The Prior Art
Applicant is not aware of any issued United States patent, or other prior art, disclosing the particular structure and function of the jewelry clasp shown and claimed herein; U.S. Pat. No. 147,965 being representative of the prior art known to applicant.
SUMMARY OF THE INVENTION
The present invention is directed to, and it is a major object to provide, a novel quick-engageable, quick-disengageable coupling or clasp for connecting the ends of a piece of jewelry such as a necklace or bracelet.
The present invention provides, as another important object, a jewelry clasp, as in the preceding paragraph, wherein the clasp includes two initially separate longitudinal bodies end-alined in use, one body having a lengthwise projecting inner end tongue, and the other body having an inner end slot and adapted for reception, by longitudinal insertion through the slot, of the tongue; the clasp being particularly characterized by the inclusion of instrumentalities operative, without more, to secure the tongue in said other body and thus quick-engage the clasp upon the tongue being so inserted, and to release the tongue upon relative rotation of the bodies and thus quick-disengage the clasp.
The present invention provides, as an additional object, a clasp which, while especially adapted for use with jewelry, is readily adaptable--with size variation--for other coupling uses.
The present invention provides, as a still further object, a practical, reliable, and durable jewelry clasp, and one which is easy to manufacture, including assembly, and exceedingly effective for the purpose for which it is designed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an enlarged elevation of the clasp with the male and female units disengaged and separated.
FIG. 2 is a similar view, but with the clasp rotated 45 degrees about its axis; the male unit being partly in section, and the female unit in full section. The view is taken substantially on line 2--2 of FIG. 1.
FIG. 3 is a cross section taken substantially on line 3--3 of FIG. 2.
FIG. 4 is a cross section taken substantially on line 4--4 of FIG. 2.
FIG. 5 is a cross section taken substantially on line 5--5 of FIG. 2.
FIG. 6 is a view similar to FIG. 2, but shows the male and female units as initially engaged.
FIG. 7 is a cross section taken substantially on line 7--7 of FIG. 6; the view showing the position of the tongue of the male unit just before rotation to latching position.
FIG. 8 is a similar view, but shows the position of the tongue of the male unit after rotation to latching position.
FIG. 9 is an exploded view showing the several parts of the clasp.
FIG. 10 is an elevation of the clasp with the male and female units disengaged and separated; the male unit being of modified form and shown partially broken away and in section.
FIG. 11 is an enlarged cross section taken substantially on line 11--11 of FIG. 10.
FIG. 12 is a fragmentary elevation, partly in section, taken substantially on line 12--12 of FIG. 11.
FIG. 13 is an enlarged cross section taken substantially on line 13--13 of FIG. 10.
FIG. 14 duplicates FIG. 11, but here is shown bracketed with FIG. 15.
FIG. 15 is an enlarged cross section showing the position of the tongue of the male unit just before rotation to latching position; FIG. 15 being bracketed with FIG. 14 to illustrate the then relative positions of the parts of the rotary mount for the tongue of the male unit.
FIG. 16 is a view similar to FIGS. 11 and 14, but, shown bracketed with FIG. 17, illustrates the relative positions of the parts of the rotary mount for the tongue of the male unit after rotation of said tongue to latching position.
FIG. 17 is a view similar to FIG. 15, but, shown bracketed with FIG. 16, illustrates the position of the tongue of the male unit as so rotated to latching position.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to the drawings, and to the characters of reference marked thereon, and at present to the embodiment of FIGS. 1-9, inclusive, the jewelry clasp of the present invention comprises--preferably in cylindrical form and in initially separated relation--a male unit, indicated generally at 1, and a female unit, indicated generally at 2, adapted to be disposed in end-to-end longitudinal alinement. The male unit 1 includes an attachment eye 3 at its outer end, and the female unit 2 includes an attachment eye 4 at its outer end.
The male unit 1 embodies a cylindrical body 5 fitted with an inner end wall 6 from which a fixed, longitudinal tongue 7 projects; the tongue 7, while rectangular in cross section, being flat; i.e., of substantial width in one dimension, but relatively narrow in the other dimension.
Immediately outwardly of the inner end wall 6, the tongue 7 is formed, on opposite sides, with opposed, parallel notches 8 which open laterally and extend diagonally transversely of, and relative to, the major longitudinal plane of said tongue.
The female unit 2 embodies a cylindrical body 9 fitted with an inner end wall 10; such wall 10 being formed with a diametral or symmetrically disposed rectangular opening or slot 11 dimensioned for the matching but sliding reception therethrough of the tongue 7 of male unit 1.
An elongated, turnable sleeve 12 is disposed in close fitting relation in the cylindrical body 9, and such sleeve extends between the end wall 10 and a radially thin ring 13 fixed in said body 9 intermediate the ends thereof.
Within the confines thereof, but open to both of its ends, the turnable sleeve is formed with a four-sided, longitudinal, tongue-receiving passageway 14 which is formed--in rectangular cross section--so that at the end adjacent wall 10 such passageway initially matchingly registers with the slot 11. The passageway 14 is thus adapted to receive the tongue 7 in matching, sliding relation upon insertion of said tongue 7 through the slot 11 in end wall 10.
A disc 15 is disposed in close fitting relation in the body 9, and initially abuts the fixed ring 13 on the side opposite the sleeve 12; the disc 15 being formed with a fixed, longitudinal tongue 16 which projects through the ring 13 and thence into the passageway 14. The tongue 16 is of substantially the same cross section as tongue 7 and initially fully engages in passageway 14 in matching but sliding relation. The combined length of tongues 7 and 16 is substantially greater than the length of passageway 14 plus the axial extent of ring 13.
Immediately adjacent the disc 15, the tongue 16 is provided, on each of its opposite edges, with an outwardly projecting pin 17 which extends radially of the ring 13 and initially seats in a corresponding pin-receiving notch 18 in said ring 13. Such pin and notch arrangement provides, in effect, a clutch which is initially engaged.
The body 9, of the female unit 2, is closed at its outer end by an end head 19 suitably secured in place; the securing means being here shown, for illustration, as screws 20. As shown, the end head 19 is fitted with the eye 4.
A helical spring 21 is disposed in body 9 and extends, in connection, between the head 19 and the disc 15; one end of the spring hook-engaging a neck 22 of head 19, while the other end of the spring tip-engages in a receiving hole 23 in the disc 15.
The helical spring is always under some loading both as to compression and torque, and thus--while the torque effect tends to rotate disc 15 in one direction--the compression effect (i.e., tendency to expand) maintains the pins 17 in notches 18 so that the disc is releasably held against rotative motion.
In use of the above-described jewelry clasp, it is manipulated and functions as follows:
With the hands of the wearer finger-grasping the units 1 and 2 of the clasp, the tongue 7 is projected through slot 11 in wall 10, and the bodies 5 and 9 are moved axially together until the tongue is inserted to full extent in the passageway 14, and at which time the bodies 5 and 9 are in end abutment.
Upon the tongue 7 being thus thrust into the passageway 14, tongue 7 end-abuts tongue 16 and shifts the latter in a direction to move the disc 15 a distance, in the direction of head 19, sufficient to withdraw the pins 17 from notches 18 and thus un-clutch such disc, and which, at the same time, further loads and hence increases the compression effect of the spring 21.
Upon the disc 15 being thus un-clutched, the spring 21--through the medium of its torque effect--simultaneously rotates the disc 15 and consequently the tongue 16, sleeve 12, and tongue 7; the latter, including all of body 5, turning until adjacent portions of end wall 10 quick-engage in the laterally opening notches 8 to provide not only a stop for the turning motion, but latching the tongue against accidental withdrawal and escape from the passageway 14. Such latching of the clasp is yieldably maintained by the torque effect of the spring 21, and until it is desired to disengage the clasp.
Quick-disengagement of the clasp is accomplished as follows:
With the hands of the wearer finger-grasping the units 1 and 2 of the clasp, the bodies 5 and 9 are relatively rotated about the axis thereof, against the torque of spring 21, and in a direction such that the tongue 7 is manually counter-rotated until the engaged portions of the end wall 10 escape the notches 8, whereupon--under the compression effect of spring 21--the disc 15 and tongue 16 are thrust axially in a direction to re-seat pins 17 in notches 18 and simultaneously shift tongue 7 out of the passageway a distance sufficient to dispose the notches 8 outwardly of end wall 10, whereupon the clasp can be disengaged by manual completion of withdrawal of tongue 7 from the female unit 2.
When the clasp is quick-engaged in the manner previously described, the body 5 of the male unit 1 part-turns in the wearer's hand when the rigidly connected tongue 7 is spring-rotated to latching position. If it is desired to prevent such part-turning, the male unit 1 may be modified by the inclusion of a rotary mount for the tongue and in the manner disclosed in FIGS. 10-17, inclusive, of the drawings, and wherein unmodified parts--corresponding to FIGS. 1-9, inclusive--bear like reference numerals.
In the modified male unit 1 of FIGS. 10-17, the body 5 is provided at its inner end with an inset, turnable, circular plate 24; the tongue 7 being fixedly secured at its adjacent end to, and projects from, such plate in symmetrical relation thereto. The plate 24 is turnably supported by an axial spindle assembly 25 retained by a nut 26 and journaled in connection with a fixed radial wall 27 mounted in body 5 in adjacent but inwardly spaced relation to the turnable plate 24.
A coil spring 28 is disposed between turnable plate 24 and fixed wall 27 and surrounds the adjacent portion of the spindle assembly 25; such spring being anchored at one end to a stud 29 on the back face of turnable plate 24, and at the other end is anchored to fixed wall 27 as at 30. The stud 29--which extends parallel to the axis of the spindle assembly 25--extends into a short, arcuate, concentric slot 31 in the fixed wall 27; the loading of the spring being such that the stud 29 is normally maintained in one end of slot 31 and with the tongue 7 in a rotary position normal to the body 5 as shown, for example, in FIGS. 10, 11, and 14.
Upon the engagement of the clasp as previously described and when the tongue 7 of the male unit 1 is thrust into the body 9 of the female unit 2, such tongue 7 part-turns as the clasp latches, but the body 5 does not respond to such turning motion by reason of the limited rotation permitted by the spindle assembly 25. When such limited rotation of the tongue 7 occurs, the plate 24, of course, part-turns, and this moves the stud 29 from one end of the slot 31 (see FIGS. 11 and 14) to the other end of such slot (see FIG. 16), and which is in a direction to further load the spring 28. Thereafter, upon subsequent disengagement of the clasp by withdrawal of the tongue 7 from the female unit 2, the spring 28 counter-rotates the plate 24, returns the stud 29 to the starting end of slot 31, and also returns the tongue to its normal position.
Thus, with the above-described rotary mount for the tongue 7, the body 5 of the male unit 1 does not--in the embodiment of FIGS. 10-17, inclusive--part-turn in the wearer's hand when the clasp is engaged and latched.
From the foregoing description, it will be readily seen that there has been produced such a jewelry clasp as substantially fulfills the objects of the invention, as set forth herein.
While this specification sets forth in detail the present and preferred construction of the jewelry clasp, still in practice such deviations from such detail may be resorted to as do not from a departure from the spirit of the invention as defined by the appended claims. | 4y
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CROSS-REFERENCE
[0001] The present application claims priority to U.S. Provisional Application No. 61/177,621, filed May 12, 2009, the entirety of which is incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a graphical element laminate for use in forming a skate boot, and a skate boot incorporating the graphical element laminate.
BACKGROUND OF THE INVENTION
[0003] Many people enjoy skating as a recreational pastime, either with ice skates or with roller skates such as in-line roller skates. This pastime is generally made more enjoyable by providing skate boots having a distinctive and attractive appearance. In addition, manufacturers of skates have a desire to produce skate boots having a distinctive and attractive experience as they compete with other manufacturers for retail sales. As a result, skate boots are available having a wide variety of exterior colors and patterns.
[0004] The variety of colors and patterns on conventional skate boots presents a number of difficulties in the manufacturing process. One common method of producing an aesthetically pleasing skate boot is to arrange decorative pieces of leather, fabric or plastic (as the case may be) having different colors on the outwardly-facing surface of the skate boot. While this method is generally effective, it requires a potentially large number of irregularly-shaped pieces of different materials to be joined together in proper alignment with one another. This process is labour-intensive, and requires the person assembling the pieces of material to become familiar with different patterns when working on different models of skate, or as styles evolve over time. As a result, the time and cost required to manufacture a skate boot may be increased, and there may in some cases be a disincentive to create new or complex skate boot designs. In addition, the numerous seams or other joints between the pieces of material may be prone to fraying or loosening over time.
[0005] Another method of producing an aesthetically pleasing skate boot is to fashion the outer layer of the skate boot out of a plastic material, such as thermoplastic polyurethane (TPU). This allows the option of providing the appearance of different textures in different areas of the skate boot. However, this method presents difficulty in applying different colors to different areas of the skate boot. One approach is to print a design on the outside of the plastic, but this printing, particularly on the quarter, may be prone to cracking, chipping or other damage during use of the skate, resulting in an unattractive appearance. In addition, plastic is considered by some users to be less attractive than fabric, particularly a woven composite fabric. Finally, this method may also in some cases provide a disincentive to create new skate boot designs, because even a small change in design might require a new and costly mold.
[0006] Some skates are used in competitive activities, such as hockey. The aforementioned inconveniences are particularly exacerbated when the skates are used in such activities, as these activities subject the skate boots to an increased frequency of impact and abrasion, from, for example, hockey sticks and pucks and/or the blades or boots of other skaters. While current skate boots are generally of sufficient quality to maintain their structural integrity and usefulness under these conditions, these impacts and abrasions may adversely affect the aesthetic appeal of the skate boots. Plastic outer surfaces and the colors applied thereon may be prone to cracking, denting and chipping, and fabric or leather outer surfaces or the seams/joints between them may become scratched, frayed or loosened, all of which reduces the aesthetic appeal of the skate boots.
[0007] At least for these reasons, improvements in the art of skate boots would be desirable.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to ameliorate at least some of the inconveniences present in the prior art.
[0009] It is also an object of the present invention to provide a skate boot having a plastic outer layer and a composite inner layer, the plastic outer layer having at least one printed region and at least one transparent or translucent region through which the composite material can be seen.
[0010] It is also an object of the present invention to provide a method of manufacturing a skate boot having a plastic outer layer and a composite inner layer, the plastic outer layer having at least one printed region and at least one transparent or translucent region through which the composite material can be seen.
[0011] It is also an object of the present invention to provide a graphical element for a skate boot wherein the appearance of woven or non-woven fabric is interspersed with the appearance of printed elements.
[0012] It is also an object of the present invention to provide a method of manufacturing a skate boot wherein the appearance of woven or non-woven fabric is interspersed with the appearance of printed elements.
[0013] Thus, in one aspect, the invention provides a graphical element laminate for use in forming a skate boot, the laminate comprising: a base layer having a base layer inner side and a base layer outer side opposite the base layer inner side; a first thermoplastic layer laminated on the base layer outer side of the base layer, the first thermoplastic layer having a first thermoplastic layer inner side and a first thermoplastic layer outer side opposite the first thermoplastic layer inner side; a graphical element printed on at least one portion of the first thermoplastic layer inner side of the first thermoplastic layer, at least a portion of the first thermoplastic layer overlying the graphical element being at least one of transparent and translucent such that when the laminate forms part of the skate boot, at least a portion of the graphical element is visible through the first thermoplastic layer from an exterior of the skate boot. The graphical element may be opaque, translucent or transparent, or any combination thereof.
[0014] Preferably, the base layer outer side of the base layer includes a design element, and at least a portion of the first thermoplastic layer overlying the design element is at least one of transparent and translucent such that when the laminate forms part of the skate boot, at least a portion of the design element is visible through the first thermoplastic layer from the exterior of the skate boot. The design element may be any nature of visible characteristic of the base layer, including one or more of texture, shape, color or applied image.
[0015] Preferably, the first thermoplastic layer comprises at least one of a thermoplastic ionomer resin and polyurethane; the base layer comprises at least one of polyester, glass fiber, and carbon fiber. Optionally, the base layer may include a woven material and the design element is a weave of the material.
[0016] In another aspect, the invention provides a graphical element laminate for use in forming a skate boot, the laminate comprising: a base layer having a base layer inner side and a base layer outer side opposite the base layer inner side; a first thermoplastic layer laminated on the base layer outer side of the base layer, the first thermoplastic layer having a first thermoplastic layer inner side and a first thermoplastic layer outer side opposite the first thermoplastic layer inner side; a second thermoplastic layer laminated on the first thermoplastic outer side of the first thermoplastic layer, the second thermoplastic layer having a second thermoplastic layer inner side and a second thermoplastic layer outer side opposite the second thermoplastic layer inner side; a graphical element printed on at least one portion of at least one of the first thermoplastic layer outer side of the first thermoplastic layer and the second thermoplastic layer inner side of the second thermoplastic layer, at least a portion of the second thermoplastic layer being at least one of transparent and translucent such that when the laminate forms part of the skate boot at least a portion of the graphical element is visible through the second thermoplastic layer from an exterior of the skate boot.
[0017] Preferably, the base layer outer side of the base layer includes a design element, and at least portions of the first thermoplastic layer and the second thermoplastic layer of portions thereof overlying the design element of the base layer are at least one of transparent and translucent such that when the laminate forms part of the skate boot at least a portion of the design element is visible through the first thermoplastic layer and the second thermoplastic layer from an exterior of the skate boot.
[0018] Preferably, the first thermoplastic layer and the second thermoplastic layer each comprise at least one of a thermoplastic ionomer resin and polyurethane; the base layer comprises at least one of polyester, glass fiber, and carbon fiber. Optionally, the base layer may include a woven material and the design element is a weave of the material.
[0019] In yet another aspect, the invention provides a skate boot including a graphical element laminate as described hereinabove.
[0020] In yet another aspect, the inventions provides a method of manufacturing a skate boot, comprising: providing a first sheet of thermoplastic material, the first sheet having a first side and an opposing second side, the thermoplastic material being at least one of translucent and transparent; printing a graphic element on the first side of the first sheet of thermoplastic material; providing a second sheet of base layer material, the second sheet having a first side and an opposing second side, the first side of the second sheet of base layer material having a design element; positioning the first side of the first sheet onto the first side of the second sheet such that the graphic image is disposed between the first side of the first sheet and the first side of the second sheet; joining the first sheet and the second sheet together to form a graphic element laminate; and affixing the second side of the second sheet to an outer surface of a skate boot core.
[0021] In yet another aspect, the invention provides a method of manufacturing a skate boot, comprising: providing a first sheet of a first thermoplastic material, the first sheet having a first side and an opposing second side, the first thermoplastic material being at least one of translucent and transparent; printing a graphic element on the first side of the first sheet of thermoplastic material; providing a second sheet of a second thermoplastic material, the second sheet having a first side and an opposing second side, the second thermoplastic material being at least one of translucent and transparent; positioning the first side of the first sheet onto the first side of the second sheet such that the graphic image is disposed between the first side of the first sheet and the first side of the second sheet; joining the first sheet and the second sheet together; providing a third sheet of base layer material, the third sheet having a first side and an opposing second side, the first side of the third sheet of base layer material having a design element; positioning the second side of the first sheet onto the first side of the third sheet such that the design element is disposed between the second side of the first sheet and the first side of the third sheet; joining the first sheet and the third sheet together to form a graphic element laminate; and affixing the second side of the third sheet to an outer surface of a skate boot core.
[0022] In yet another aspect, the invention provides a method of manufacturing a skate boot, comprising: providing a first sheet of a first thermoplastic material, the first sheet having a first side and an opposing second side, the first thermoplastic material being at least one of translucent and transparent; providing a third sheet of base layer material, the third sheet having a first side and an opposing second side, the first side of the third sheet of base layer material having a design element; positioning the second side of the first sheet onto the first side of the third sheet such that the design element is disposed between the second side of the first sheet and the first side of the third sheet; joining the first sheet and the third sheet together to form a graphic element laminate; printing a graphic element on the first side of the first sheet of thermoplastic material; providing a second sheet of a second thermoplastic material, the second sheet having a first side and an opposing second side, the second thermoplastic material being at least one of translucent and transparent; positioning the first side of the first sheet onto the first side of the second sheet such that the graphic image is disposed between the first side of the first sheet and the first side of the second sheet; joining the first sheet and the second sheet together; and affixing the second side of the third sheet to an outer surface of a skate boot core.
[0023] For purposes of this application, the terms “inner” and “outer”, in reference to a layer of a graphic element laminate of the present invention, refer to the orientation of a side of the layer with respect to the side facing the interior or the exterior of a skate boot into which the graphic element laminate is incorporated.
[0024] For purposes of this application, the term “quarter”, in reference to a skate or skate boot, refers either individually or collectively to the left or right portions of the boot upper, and should be understood to include, but is not limited to, an integral piece or package of material that forms both the left and right upper portions of the assembled boot.
[0025] For purposes of this application, the term “printing” refers to any method of printing, applying or transferring an image onto a target surface, including digital printing such as ink jet or laser printing, gravure printing, flexography, lithography, and silk screening.
[0026] Embodiments of the present invention each have at least one of the above-mentioned objects and/or aspects, but do not necessarily have all of them. It should be understood that some aspects of the present invention that have resulted from attempting to attain the above-mentioned objects may not satisfy these objects and/or may satisfy other objects not specifically recited herein.
[0027] Additional and/or alternative features, aspects, and advantages of embodiments of the present invention will become apparent from the following description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] For a better understanding of the present invention, as well as other aspects and further features thereof, reference is made to the following description which is to be used in conjunction with the accompanying drawings, where:
[0029] FIG. 1 is a logic diagram showing a method of manufacturing a skate according to a first embodiment;
[0030] FIG. 2 is a logic diagram showing a method of manufacturing a skate according to a second embodiment;
[0031] FIG. 3 is a logic diagram showing a method of manufacturing a skate according to a third embodiment;
[0032] FIG. 4 is a right side elevation view of an ice skate manufactured according to an embodiment of the invention;
[0033] FIG. 5 is an exploded view showing the layers of material in a skate quarter according to an embodiment of the invention; and
[0034] FIG. 6 is a cross-sectional view of the skate quarter of FIG. 5 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0035] In the present application, referring to FIGS. 1 and 5 , a method of assembly of a quarter 10 for a skate boot 12 (such as a skate boot 12 as shown in FIG. 4 ) will be described according to a first embodiment, beginning at step 100 with a first flat sheet 14 . It should be understood that the method can be applied to only a portion of the quarter. It should be further understood that the method is not limited to a quarter 10 , but can also be applied to other portions of the skate boot, such as the tongue or the vamp. The sheet 14 comprises a thermoplastic material, such as a thermoplastic ionomer resin (e.g. Surlyn™ 1601-2 or Surlyn™ 8940—Surlyn is a trademark of E. I. du Pont de Nemours and Company) or thermoplastic polyurethane (TPU). The sheet 14 is preferably about 0.2 mm thick, though it should be understood that the thickness may vary according to the particular application and the structural properties desired for the assembled skate boot 12 . The sheet 14 is preferably either entirely transparent or translucent, and may be colorless or tinted with a desired color, for reasons that will be discussed in detail below. The process continues at step 105 .
[0036] At step 105 , a graphic element 20 is printed on a first side 16 of the sheet 14 , using an appropriate ink or dye that will adhere to the selected thermoplastic material. For example, if the sheet 14 is composed of TPU, a polyurethane based ink could be used. The graphic element 20 may be printed on the sheet 14 by any suitable method known in the art. It should be understood that the graphic element 20 may be any arrangement of one or more colors chosen to give the skate boot 12 an aesthetically pleasing appearance, and may include one or more words, one or more geometric shapes, a brand name, company logo or trademark. The graphic element 20 is dimensioned and positioned on the sheet 14 relative to the pattern 22 (shown in dashed lines), which represents the outline of the skate quarter 10 that will later be cut out from the sheet 14 and incorporated into the skate boot 12 , to ensure that the graphic element 20 will appear in the desired location on the assembled skate boot 12 . The pattern 22 may correspond to a left quarter or a right quarter of the skate boot 12 , or both, or of a unitary quarter (as shown in FIG. 4 ) that extends on both the left and right sides of the skate boot 12 . The graphic element 20 may optionally be an opaque graphical element covering only one or more parts 28 of the pattern 22 , in which case only the parts 30 of the pattern 22 not covered by the graphic element 20 retain the transparent or translucent appearance of the sheet 14 . The process continues at step 110 .
[0037] At step 110 , a second flat sheet 24 of thermoplastic material is laminated onto the first side 16 of the first sheet 14 , such that the graphic element 20 is disposed between the sheets 14 , 24 , to produce a graphics sub-laminate 32 . The lamination process is believed to be well known, and will not be discussed in detail. The second sheet 24 is preferably made of the same or similar thermoplastic material as the first sheet 14 , and is of the same or similar dimensions, to ensure that the second sheet 24 properly adheres to both the printed parts 28 and the unprinted parts 30 of the first sheet 14 over at least the entire surface of the pattern 22 . The second sheet 24 may be colorless or tinted with a desired color, and is preferably either entirely transparent or translucent, for reasons that will be discussed in detail below. The process continues at step 115 . It is contemplated that step 110 may be omitted, in which case the graphics sub-laminate 32 would consist of only the first sheet 14 and the graphic element 20 , and the process would proceed from step 105 directly to step 115 .
[0038] At step 115 , the graphics sub-laminate 32 is laminated onto a base layer 34 in a known manner, such that the second side 18 of the first sheet 14 adheres to the base layer 34 to form a graphical element laminate 26 . The base layer 34 is preferably a flat sheet of fabric, such as a woven cloth containing natural fibers or synthetic fibers such as glass fiber, polyester, or carbon fiber, or any suitable woven or non-woven composite. The base layer 34 may alternatively be or contain any other suitable material, such as a paper or film with a design element printed thereon. The process continues at step 120 .
[0039] At step 120 , the graphical element laminate 26 is laminated to a skate boot quarter core 36 to form a skate quarter blank 46 . The skate boot quarter core 36 may be composed of several layers 38 , 40 , 42 , 44 , depending on the intended application and the structural properties desired. In the embodiment shown, the skate boot quarter core 36 includes a layer 38 of foam such as expanded polypropylene compressed between an inner reinforcement layer 40 and an outer reinforcement layer 42 . The reinforcement layers 40 , 42 may be made of any suitable material, for example a composite non-woven polyester sheet such as KP, available from Kang-Pao Industrial Co. in China, or Formo™ (a trademark of Texon International). It is contemplated that the inner reinforcement layer 40 may optionally be omitted, in which case only the outer reinforcement layer 42 would be used. The skate core also preferably includes an outer layer 44 composed of a suitable thermoplastic material, preferably Surlyn or polyurethane having a thickness of 0.25-1.1 mm, onto which the graphical element laminate 26 is laminated. It should be understood that a number of suitable alternative compositions are known for the skate boot quarter core 36 , and all are considered to be within the scope of the invention. The process continues at step 125 .
[0040] At step 125 , the skate quarter blank 46 is cut along the contour of the pattern 22 , for example by using a die or other suitable cutting tool, and molded into the desired three-dimensional shape in a known manner, to form the skate quarter 10 . The process continues at step 130 .
[0041] At step 130 , the skate quarter 10 is assembled into an ice skate 48 . A skate boot 12 is formed by the addition of various known parts, which may include an insole (not shown), an outsole 52 , a tongue 54 , a toe protector 56 , eyelets 58 and laces 60 . It is contemplated that the assembly of the skate boot 12 may be done in any known manner, for example in the manner described in U.S. Pat. No. 7,451,991, the contents of which are incorporated by reference herein. It should be understood that, as a result of the positioning of the graphic element 20 relative to the pattern 22 at step 105 , the graphic element 20 is properly aligned on the skate boot 12 . The ice skate 48 is formed by fastening a blade holder 62 with a blade 64 to the outsole 52 in a known manner. It is contemplated that the skate boot 12 may alternatively be used in a roller skate (not shown), for example an inline roller skate, in which case a frame adapted to hold two or more wheels would be fastened to the outsole 52 instead of the blade holder 62 and blade 64 . The process concludes at step 135 .
[0042] Referring to FIGS. 2 and 5 , a method of assembly of a quarter 10 for a skate boot 12 (such as a skate boot 12 as shown in FIG. 4 ) will be described according to a second embodiment, beginning at step 200 with a base layer 34 . The base layer 34 is preferably a flat sheet of fabric, such as a woven cloth containing natural fibers or synthetic fibers such as such as glass fiber, polyester, or carbon fiber, or any suitable woven or non-woven composite. The process continues at step 205 .
[0043] At step 205 , a first flat sheet 14 is laminated onto the base layer 34 in a known manner. The first flat sheet 14 comprises a suitable thermoplastic material, such as a thermoplastic ionomer resin or thermoplastic polyurethane (TPU). The sheet 14 is preferably about 0.2 mm thick, though it should be understood that the thickness may vary according to the particular application and the structural properties desired for the final skate boot 12 . The first flat sheet 14 may be colorless or tinted with a desired color, and is preferably either transparent or translucent, for reasons that will be discussed in detail below. The process continues at step 210 .
[0044] At step 210 , a graphic element 20 is printed on the outwardly-facing side 16 of the first flat sheet 14 , using an appropriate ink or dye that will adhere to the selected thermoplastic material. For example, if the sheet 14 is composed of TPU, a polyurethane based ink could be used. The graphic element 20 may be printed on the first flat sheet 14 by any suitable method known in the art. It should be understood that the graphic element 20 may be any arrangement of one or more colors chosen to give the skate boot 12 an aesthetically pleasing appearance, as will be discussed below in further detail. The graphic element 20 may additionally or alternatively include a brand name, company logo or trademark. The graphic element 20 is dimensioned and positioned on the sheet 14 relative to the pattern 22 (shown in dashed lines), which represents the outline of the skate quarter 10 that will later be cut out from the sheet 14 and incorporated into the skate boot 12 . The pattern 22 may correspond to a left quarter or a right quarter of the skate boot 12 , or both, or of a unitary quarter (as shown in FIG. 4 ) that extends on both the left and right sides of the skate boot 12 . The graphic element 20 may optionally be an opaque graphical element covering only one or more parts 28 of the pattern 22 , in which case only the parts 30 of the pattern 22 not covered by the graphic element 20 retain the transparent or translucent appearance of the sheet 14 . The process continues at step 215 .
[0045] At step 215 , a second flat sheet 24 of thermoplastic material is laminated onto the side 16 of the first sheet 14 to produce a graphical element laminate 26 . The lamination process is believed to be well understood, and will not be discussed in detail. The second sheet 24 is preferably made of the same or similar thermoplastic material as the first sheet 14 , and is of the same or similar dimensions, to ensure that the second sheet 24 properly adheres to both the printed parts 28 and the unprinted parts 30 of the first sheet 14 over at least the entire surface of the pattern 22 . The second sheet 24 may be colorless or tinted with a desired color, and is preferably either transparent or translucent, for reasons that will be discussed in detail below. The process continues at step 220 . It is contemplated that step 215 may be omitted, in which case the graphic element laminate 26 would consist of only the base layer 26 , the first sheet 14 and the graphic element 20 , and the process would proceed from step 210 directly to step 220 .
[0046] Steps 220 - 235 are similar to steps 120 - 135 , respectively, and as such they will not be described in detail.
[0047] Referring to FIGS. 3 and 5 , a method of assembly of a quarter 10 for a skate boot 12 (such as a skate boot 12 as shown in FIG. 4 ) will be described according to a third embodiment, beginning at step 300 with a flat sheet 14 . The sheet 14 comprises a thermoplastic material, such as a thermoplastic ionomer resin or thermoplastic polyurethane (TPU). The sheet 14 is preferably about 0.2 mm thick, though it should be understood that the thickness may vary according to the particular application and the structural properties desired for the assembled skate boot 12 . The sheet 14 may be colorless or tinted with a desired color, and is preferably either entirely transparent or translucent, for reasons that will be discussed in detail below. The process continues at step 305 .
[0048] At step 305 , a graphic element 20 is printed on a side 18 of the sheet 14 , using an appropriate ink or dye that will adhere to the selected thermoplastic material. For example, if the sheet 14 is composed of TPU, a polyurethane based ink could be used; if the sheet 14 is composed of Surlyn, a Surlyn based ink could be used. The graphic element 20 may be printed on the sheet 14 by any suitable method known in the art. It should be understood that the graphic element 20 may be any arrangement of one or more colors chosen to give the skate boot 12 an aesthetically pleasing appearance, as will be discussed below in further detail. The graphic element 20 may additionally or alternatively include a brand name, company logo or trademark. The graphic element 20 is dimensioned and positioned on the sheet 14 relative to the pattern 22 (shown in dashed lines), which represents the outline of the skate quarter 10 that will later be cut out from the sheet 14 and incorporated into the skate boot 12 . The pattern 22 may correspond to a left quarter or a right quarter of the skate boot 12 , or both, or of a unitary quarter (as shown in FIG. 4 ) that extends on both the left and right sides of the skate boot 12 . The graphical element 20 may optionally be an opaque graphical element covering only one or more parts 28 of the pattern 22 , in which case only the parts 30 of the pattern 22 not covered by the graphic element 20 retain the transparent or translucent appearance of the sheet 14 . The process continues at step 310 .
[0049] At step 310 , the printed side 18 of the sheet 14 is laminated onto a base layer 34 in a known manner, such that the side 18 of the sheet 14 adheres to the base 34 to form a graphical element laminate 26 . The base layer 34 is preferably a flat sheet of fabric, such as a woven cloth containing natural fibers or synthetic fibers such as such as glass fiber, polyester, or carbon fiber, or any suitable woven or non-woven composite. The process continues at step 320 .
[0050] Steps 320 - 335 are similar to steps 120 - 135 , respectively, and as such they will not be described in detail.
[0051] Referring to FIG. 6 , the outermost layers of the quarter 10 , from the skate boot quarter core 36 to the exterior of the skate boot 12 (such as a skate boot 12 as shown in FIG. 4 ), consist of the base layer 34 , the sheet 14 with the graphic element 20 printed thereon, and optionally the sheet 24 such as in the embodiment shown in FIG. 6 .
[0052] Referring to FIG. 4 , it should be understood that the quarter 10 of the skate boot 12 can conveniently be provided with an attractive juxtaposition of parts 28 where the printed design is visible and parts 30 where the base layer 34 is visible through the unprinted portions of the transparent or translucent sheets 14 , 24 . As a result, the parts 30 can be numerous or intricately shaped by simply printing the desired shapes on the flat surface of the sheet 14 , without the need to assemble the correspondingly numerous or complex composite inserts. In this manner, a complex design of the skate boot 12 does not result in greatly increased time, cost or effort required to assemble the skate boot 12 . The possibility of tinting or shading the sheets 14 , 24 allows an additional way to enhance the aesthetic appeal of the skate boot 12 without increasing manufacturing costs. In addition, if a different appearance is desired, the persons who assemble the skate would not generally require additional training to learn the proper placement of the inserts corresponding to the new design, likely resulting in further cost saving and providing a greater incentive to create new attractive skate boot designs. In addition, if desired the second sheet 24 can advantageously be given a glossy appearance. In addition, the second sheet 24 may be either smooth or embossed with a texture or pattern.
[0053] It should be understood that the methods described above allow for the production of a skate boot 12 having a customized appearance in a cost-efficient manner. In further variations of the methods described above, a database is provided, for containing at least one information record corresponding to at least one customized boot design. A customer can thereby be given the option to personalize the appearance of his skate boot 12 , by either selecting one of a number of pre-existing designs from the database, combining pre-existing design components from the database to form an original design, or providing his own design to the database in a suitable digital format. A selected customized graphic element 20 corresponding to the customer's desired design is retrieved from the database and printed on the sheet 14 or 24 at step 105 , 210 , or 305 (as the case may be), preferably using a method of digital printing such as ink jet or laser printing, to create the customized skate boot 12 .
[0054] Referring to FIGS. 4 , 5 and 6 , it should also be understood that the skate boot 12 is reasonably durable and resistant to wear and damage. The transparent or translucent layers 14 , 24 allow portions of the composite base layer 34 to be visible without being exposed to the environment. The layers 14 , 24 protect the base layer 34 from some types of damage that may ordinarily occur during use of the skate 48 , for example due to the impact of pucks, sticks and other skates if the skate 48 is used for playing ice hockey. In addition, the absence of composite inserts eliminates the possibility that seams or joints between design components could become frayed or damaged. The second sheet 24 additionally serves to protect the graphic element 20 from becoming damaged due to chipping or abrasion during use of the skate 48 .
[0055] Referring to FIGS. 5 and 6 , it should also be understood that if two thermoplastic sheets 14 and 24 are used (such as in the embodiment shown in those FIGS. 5 and 6 ), the layers of material in the quarter 10 can advantageously be ordered in a way that ensures reliable adhesion between successive layers. In particular, the graphic element 20 can be placed between the two sheets 14 , 24 of the thermoplastic material to which it is designed to adhere, and the sheet 14 of thermoplastic material can be placed between the sheet 24 , preferably made of the same or a similar thermoplastic material, and the base layer 34 . As a result, the skate boot 12 is relatively convenient and inexpensive to manufacture, the quality of the final product is consistent, and the costs of scrap due to manufacturing defects are generally reduced.
[0056] Modifications and improvements to the above-described embodiments of the present invention may become apparent to those skilled in the art. The foregoing description is intended to be exemplary rather than limiting. The scope of the present invention is therefore intended to be limited solely by the scope of the appended claims. | 4y
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BACKGROUND
[0001] 1. Technical Field
[0002] The embodiments herein generally relate to an all-purpose protective cover configured to be used with a movable carriage. Specifically, the embodiments described herein relate to an umbrella cover configured to protect operator of a carriage from weather extremities such that the cover is conveniently mountable on the carriage.
[0003] 2. Description of the Related Art
[0004] Manually operated movable carriages, specifically, wheel chairs and baby strollers, have elaborate arrangements for the safety and well being of its occupants but seldom focus on the operator who handles such carriages. An operator of such a carriage has to manage the movement of the carriage which generally involves both his hands, thus making it further difficult for him to use a protective cover, like an umbrella, with one hand and to maneuver the carriage with the other.
[0005] U.S. Pat. No. 4,919,379 discloses a universal clamping fixture for attaching a wide variety of umbrellas, sunscreens etc. to a baby carriage. The clamps provided therein are rigid and provide a very restrictive movement to the umbrella forcing the operator to be satisfied with an orientation of the umbrella that he has clamped and is practically helpless if, say, the wind or rain, changes direction.
[0006] U.S. Pat. No. 6,244,557 discloses an umbrella mounting device for a stroller. The patent, however, describes such placement of said mounting device (and hence the umbrella) that it blocks the forward view of the operator. Also, the patent fails to provide any arrangement for keeping back the umbrella when not in use.
[0007] US 20090205692 relates to shades that could be attached to walkers and other mobility aids. The shades of the '692 published application can be rotated from a functionally horizontal orientation to a functionally vertical orientation around a connector joint placed on the shaft bearing the shade. The shaft, in turn, is attached to the walker through a pair of frictional collars. Such an arrangement is restrictive of a full rotation of the shade bearing shaft and even in a closed shade state, the shaft is held in an upright position, thus creating an unwarranted obstacle in the path of the operator.
[0008] U.S. Pat. No. 7,493,708 discloses an umbrella that could be attached to a stroller. The umbrella is fairly large to cover the operator as well as the entire carriage and requires an additional counterweight to balance the weight of the umbrella. Further, straps are provided at the rear end of the umbrella which is fastened to the legs of the operator. Such an arrangement is not only cumbersome for the operator but also creates a nuisance in the public.
[0009] There therefore exists a need in the art to provide for a protective cover that not only provides an operator desired shield from weather extremities but is also attached to the carriage in a manner that it allows an operator the flexibility to not only rotate and configure the cover according to his need but also adjust the height of the cover so as to withstand different weather conditions and take operator's height into consideration. Further, a protective cover of such nature must also be designed in a manner to not let wind or heavy rain topple it to an inverted position. Finally, the protective cover must take minimal space, should be less cumbersome, and be convenient to use and store.
SUMMARY
[0010] In view of the foregoing, an embodiment herein provides a protective cover for manually operated movable carriages. Specifically, the protective cover of the present invention includes a double layered canopy portion and a shaft portion, wherein the shaft portion further includes an attachment device that can be securely clamped onto the body of such movable carriages. A dual clamp mechanism is provided with the attachment device to help an operator adjust the orientation of the protective cover according to his requirement and also to allow a 360° rotation to a closed protective cover thus achieving an easy storage solution. Further, the protective cover is structured and designed to withstand extreme weather conditions without getting toppled over.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The detailed description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar items.
[0012] FIG. 1 illustrates side view of a baby carriage with a protective cover in open position according to an embodiment herein;
[0013] FIG. 2 illustrates front view of a protective cover according to an embodiment herein;
[0014] FIG. 3 illustrates side view of an attachment device according to an embodiment herein;
[0015] FIG. 4 illustrates different orientations of a protective cover achieved through a clamp mechanism according to an embodiment herein;
[0016] FIG. 5 illustrates side view of a baby carriage with a protective cover in closed position according to an embodiment herein;
[0017] FIG. 6 illustrates a mechanism to achieve desired height of a protective cover according to an embodiment herein.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0018] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0019] FIG. 1 illustrates a device 100 depicting a protective cover 102 attached to a baby carriage 104 , also referred to as stroller hereinafter, according to an embodiment. The protective cover 102 can be configured to protect the caregiver of the stroller 104 from rain, sun, and wind. In an embodiment, the protective cover 102 can be attached to the baby carriage 104 through an attachment means, as would be described in detail with reference to subsequent figures.
[0020] FIG. 2 illustrates front view of a protective cover 102 . In an embodiment, the protective cover 102 can be an umbrella or an umbrella like device. In another embodiment, the protective cover 102 includes a canopy portion 202 and a shaft portion 204 . The canopy portion 202 of the protective cover 102 can further include an upper portion 206 and a lower portion 208 . In an embodiment, the upper portion 206 of the canopy 202 can be made of an SUV and a permeable textile material and the lower portion 208 of the canopy 202 can be made of a clear permeable textile. The upper portion 206 , through an SUV and permeable textile based material, provides a durable and rigid support to the protective cover 102 and is made of suitable, weather-proof material to bear conditions like harsh rain drops, frozen precipitation etc. The lower portion 208 of the canopy 202 , on the other hand, is made of a transparent material to allow the operator or caregiver of the stroller 104 clear visibility. In an embodiment, the upper portion 206 and the lower portion 208 can be placed over each other so as to create a vented hood design for the canopy 202 . Such design ensures a secure exit of incoming wind, thereby preventing the protective cover 102 from inverting against the force of wind.
[0021] The shaft portion 204 of the protective cover 102 , in an embodiment, comprises a central shaft 210 , a telescoping means 212 , a flexible metal tubing 214 , an attachment device 216 and a flared end piece 218 . In an embodiment, the central shaft 210 can comprise of two or more central shaft components, with one shaft component being slidably movable within the recess of the other component. The different shaft components of the central shaft 210 can be joined at the telescoping means 212 . Referring to FIG. 2 , shaft component 210 b of central shaft 210 is slidable against the recess of slide components 210 a as is explained in detail in FIG. 6 . The central shaft 210 is preferably made of aluminum and metal so as to provide a lightweight yet stiff protective cover which is durable and weather-proof.
[0022] In another embodiment, the telescoping means 212 can be provided at a point where two shaft components of the central shaft 210 meet. The telescoping means 212 is a rotating sleeve that allows for adjustment of umbrella height. Twisting the telescoping means 212 in an anti-clockwise manner loosens the connection between the two shaft components allowing for the two shaft components to slide freely. An operator can then adjust the length of the central shaft 210 as per his/her convenience. Once the desired length is achieved, the telescoping means 212 can be twisted in a clock-wise manner to hold the shaft components of the central shaft 210 in their current position. The length adjusting feature is particularly useful for users of different heights who want the protective cover to be matching to their heights. This feature can also be useful under circumstances where one needs to adjust the height of the protective cover 102 depending upon the intensity of wind or rain.
[0023] In another embodiment, the flexible metal tubing 214 can be provided at a shaft component of the central shaft 210 to allow for small adjustments in the direction of the protective cover 102 . Functionally, moving the protective cover 102 bends the flexible metal tubing 214 . The metal tubing 214 retains its shape until it is bent into another position. Thus, the flexible metal tubing 214 provides an axis of maneuvering the direction of the protective cover 102 .
[0024] In yet another embodiment, the attachment device 216 provided on the shaft portion 204 further comprises of an inner clamp 220 and an outer clamp 222 . The attachment device 216 is a means to attach the protective cover 102 to the body of the carriage 104 , also referred to as stroller and/or baby carriage. A dual clamp mechanism, as is described below with reference to subsequent figures, can be configured to the attachment device 216 to provide separate clamps to attach, respectively, to the central shaft 210 of the protective cover 102 and the carriage body 104 . The positioning of the two clamps in close vicinity and on the same device ensures that this arrangement is clutter free and occupies a minimum possible space. The dual clamp mechanism also provides an additional benefit of swirling a closed protective cover 102 around the inner clamp axis for easy storage. The attachment device 216 can be designed to be comfortably attached to any type of carriage.
[0025] In yet another embodiment, the flare end 218 towards the end of the central shaft 210 is designed so as to provide a smooth edge to an operator using the protective cover 102 . The flare end 218 can, preferably, be of a tapering nature and be made of smooth polymeric material.
[0026] FIG. 3 illustrates side view 300 of the attachment device 216 according to an embodiment. The inner clamp 220 , also referred to as upper clamp 220 hereinafter, can be configured to attach to the shaft portion 204 of the protective cover 102 and provide a firm grip to the protective cover 102 while the outer clamp 222 , also referred to as the lower clamp 222 hereinafter, can be configured to attach to the carriage body 104 , thereby providing a firm grip to the carriage 104 . This gives the operator of the carriage 104 an advantage to not engage his hands to hold the protective cover 102 and instead use his hands to maneuver the carriage 104 . The clamps, 220 and 222 , can be rotated around their own axis and their clockwise or anticlockwise twisting can tighten or loosen their respective attachment to central shaft 210 of the carriage body 104 . The tightening and loosening of the inner clamp 220 can be particularly helpful in setting a preferred orientation for the protective cover 102 . In yet another embodiment, the attachment mechanism can also be used with other carriage 104 and/or strollers.
[0027] FIG. 4 illustrates different orientations 400 of a protective cover 102 achieved through a clamp mechanism according to an embodiment. Orientations 400 can include different orientations 402 , 404 , and 406 of the central shaft 210 , and hence of the protective cover 102 , achieved due to differential rotation of the central shaft 210 brought about by loosening the inner clamp 220 . Once the desired orientation is set, the inner clamp 220 can be tightened in its position. The outer clamp 222 can remain attached to the carriage body 104 during the whole exercise. In a preferred embodiment, the clamps are made of heavy duty plastic and aluminum. Orientation 402 demonstrates an open position of the protective cover 102 and the orientation 406 demonstrates the closed position of the protective cover 102 .
[0028] FIG. 5 illustrates a side view 500 of a baby carriage 104 with a protective cover 102 in closed position according to an embodiment. Referring to FIG. 5 , the inner clamp 220 enables an operator to place the closed protective cover 102 at a location adjacent to the main body of the carriage 104 . The closed protective cover 102 , when not in use, can be rotated around the inner clamp 220 and placed sideways to a handle or bar of the carriage 104 . The inner clamp 220 enables a 360° rotation of the closed protective cover 102 . Further, the handle or bar can be configured to provide a strap 502 to keep the closed protective cover 102 at its position. This offers a simplistic and clutter free arrangement to store the protective cover 102 when not in use. Also, when desired to use, the mechanism offered, as disclosed in the embodiment described above, to open the protective cover is simple and easy-to-follow. The operator, in such cases, can free the strap 502 and rotate the protective cover 102 along the inner clamp 220 axis to an upright position and open the protective cover 102 . The direction and height of the protective cover 102 can then be adjusted according to the embodiments described above. The clamping mechanism of the present invention, thus, provides an advantage not only in terms of space and convenience of use to an operator, but, functionally, by allowing an operator to adjust the height and bend of the protective shield as well as providing a complete flexibility of rotating the protective cover by 360 degree, also offer novel solution to the operator.
[0029] FIG. 6 illustrates a mechanism 600 to adjust the length of the central shaft 210 using the telescopic means 212 according to an embodiment. At 602 , the central shaft 210 is provided with distinct shaft components 210 a and 210 b joined at the telescopic means 212 . The telescopic means 212 , as mentioned above, is a sleeve which can be twisted to effect a loosening or tightening the connection between the two shaft components allowing them to slide freely against each other. At 602 , the telescopic means 212 is loosened to ease the connection between the shaft components 210 a and 210 b so as to enable the shaft component 210 b to be slidable against the recess of shaft component 210 a. At 604 , the length of the central shaft 210 is adjusted by allowing just the right length of the shaft component 210 b to slide against the recess of shaft component 210 a. At 606 , once the desired length is achieved, the telescoping means 212 is tightened to hold the shaft components of the central shaft 210 in their current position. | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to a hollow roller suitable for a power transmission of a planet roller type or a roller bearing.
Conventionally, when a hollow roller adapted for a power transmission of a planet type roller or a roller bearing is made of bearing steel, the surface of the steel is hardened by a carburizing process to enhance wear resistance of an outer surface when coming in contact with an opposing surface.
Conventionally, it has been considered that a soft portion should be retained at the inside of the thickness hollow roller to relax any shock.
If the hollow roller is thick enough, such a soft portion can remain. In the case of a hollow roller suitable for a compact roller bearing or a power transmission of a planet roller type which is rather thin, it is difficult to retain the soft portion at the inside of the thickness because it is difficult to precisely control the depth of carburization, in particular, due to the development of carburizing from both the outer surface and the inner side of the hollow roller. If the hollow roller is hardened from the inside and the soft portion is not retained there, tentative deformation due to shock is followed by concentration of tensile stress at the inner surface of the hollow roller, so that the portion may readily crack.
Therefore, conventionally, a rather thick hollow roller is carburized and, then, a hardened portion at the inside surface is ground to expose a soft portion at the inner surface of the hollow roller which is thin enough.
However, the inner side must be ground after the carburizing process, whereby the manufacturing steps become much to troublesome and costly.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a hollow roller with an improved structure for preventing the inner surface of the hollow roller from cracking where stress is concentrated, the hollow roller being readily fabricated at a low cost.
It is another object of the present invention to provide a hollow roller with an improved structure for eliminating the grinding of the inner surface of the hollow roller.
Briefly described, in accordance with the preferred embodiment of the present invention, the outer surface of a hollow roller except for its inner surface, is hardened, so that soft portions remain at the inner surface. Preferably, the hardening process is a carburization process for selectively carburizing the outer surface, except for the inner surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein;
FIG. 1 is a cross sectional view of a hollow roller according to a preferred embodiment of the present invention;
FIGS. 2 and 3 are cross sectional views of the hollow roller to explain partial carburization used in the present invention;
FIG. 4 is a cross sectional view of the upper half of a power transmission of a planet roller type to which the hollow roller of FIG. 1 is adapted; and
FIG. 5 is a cross sectional view of the upper half of a cylindrical roller bearing to which the hollow roller of FIG.1 is adapted.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG.1 shows a hollow roller according to a preferred embodiment of the present invention. A hollow roller 1 is made of, for example, bearing steel, cylindrical in shape. An outer surface 2 and an end surface 3 of the hollow roller 1 are subjected to carburization to thereby form a hardened portion 4 to a predetermined depth. An inner surface 6 of the hollow roller 1 is not subjected to carburization, so that the inner surface 6 remains soft. In FIG. 1, the hardened portion 4 is denoted by dots. The outer surface 2 opposing an external element during rotation is subjected to carburization, so as to prevent the abrasion of the outer surface 2.
To carry out partial carburization, the inner surface 6 of the hollow roller 1 is coated with a carburization preventive agent, such as copper, and then carburization is carried out. After carburization, the carburization preventive agent may be removed or may not.
Alternatively, as shown in FIG. 2, a bolt or shaft 20 is inserted into the hollow 5 to fastener several hollow rollers 1, in which case the inner surfaces 6 of the hollow rollers 1 and the end surfaces 3 of them are prevented from carburization. In this method, a plurality of hollow rollers 1 can be processed at once.
Still alternatively, as shown in FIG. 3, one or both sides of the hollow roller 1 are provided with a very little step 1a, so that the hollow roller 1 with the step 1a is subjected to carburization by the method described in connection with FIG. 2. In this case, only the inner surface 6 of the hollow roller 1 only is prevented from carburization. After carburization, the step 1a is removed. With this method, the end surfaces 3 of the hollow rollers 1 are subjected to carburization. As will be described in connection with FIG. 4 below. the end surfaces 3 of the hollow rollers 1 may be in contact with the opposing faces.
In any respect partial carburization can be enabled by shielding portions not to be carburized from the carburization atmosphere by any shield member. The depth of the hardened portion 4 can be controlled by controlling the depth of carburization. Preferably, a temperature of carburization is about 800° to 950° C. while the depth of carburization is about 0.5 to 1 mm. Because the un-carburized portions in the inner surface 6 of the hollow roller 1 and the end surfaces 3 are made selectively, reaming can be applied to the inner side in order to enhance the preciseness of the inner surface 6. Reaming is easier than the conventional grinding of the inner surface 6.
As stated above, when shock is applied to the hollow roller 1 in operation, the hollow roller 1 might be deformed tentatively and tensile stress is concentrated at the inner surface 6 of the hollow roller 1.
According to the present invention, if the soft portions remain at the inner surface 6 of the hollow roller 1, the inner surface 6 can be prevented from cracking at an early stage. In particular, if the hollow roller 1 is very thin, the soft portions can be selectively retained with the present invention. The inner surface 6 of the hollow roller 1 can thus be prevented from cracking at an early stage.
Further, as compared with the conventional case in which a thick hollow roller is provided which is subjected to carburizing and, then the inner surface is ground to obtain a thin hollow roller, the manufacturing steps become less costly.
FIG. 4 shows a planet roller 7 of a power transmission of a planet roller type to which the hollow roller 1 is applied. FIG. 5 shows a cylindrical roller 8 of a cylindrical roller bearing to which the hollow roller 1 is applied.
In FIG. 4, there are provided a fixed race 9, a first rotation shaft 10 functioning as a sun race, a second rotation shaft 11 coaxial with the first rotation shaft 10, a carrier 12 integrally formed at the end of the second rotation shaft 11, the carrier being rotatable in unison with the planet roller 7, a roller bearing 13 for supporting the first rotation shaft 10 to the fixed race 9, and another roller bearing 14 for supporting the second rotation shaft 11 to the fixed race 9.
In FIG. 5, there are provided an outer race 15, an inner race and a cage 17.
In these preferred embodiments of the present invention, the hardened portions 4 are formed at the outer surface 2 and the end surface 3. It may be possible to form the hardened portions only at the outer surface 2 or at least a predetermined part of the outer surface 2. The hollow roller 1 is exemplified to be cylindrical, but should not be limited for example. It may be tapered.
As mentioned above, in accordance with the present invention, upon receipt of shock to the hollow roller, the stress is concentrated on the inner surface of the hollow roller. However, since the carburization process is applied to the portions except the inner surface of the hollow roller, the inner surface of the hollow roller and the inside of the hollow roller selectively have soft portions to prevent the inner surface of the hollow roller from starting to crack.
Further, without the grinding of the hardened inside surface in the conventional case, the manufacturing steps are simplified with a low cost according to the present invention.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications are intended to be included within the scope of the following claims. | 4y
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The present invention relates to a fitting for horticultural lighting, comprising a housing for connecting equipment, a lamp holder provided in the housing and a reflector, wherein a lamp to be fitted in the lamp holder extends into the area of the reflector.
Such fittings are generally known.
In such fittings the housing for the connecting equipment and the reflector have such shapes that a certain housing for connecting equipment is fit for only one single reflector; the reflector and the housing are an inseparable unit. In horticulture it often happens that the crop produced in an illuminated area has to be changed, so that the distance between the fittings and the crops has to be changed and that the reflector has to be adapted. Of course, it is a very costly matter to replace all fittings as a whole.
The present invention aims to provide such a fitting, wherein the reflector can be exchanged for a reflector with another configuration.
This aim is reached in that connecting means between the housing and the reflector are such that the reflector can be replaced by a reflector with another configuration.
Consequently, in an illumination installation the reflectors can be replaced by reflectors with another configuration, so that the lighting properties of the fitting can be adapted to changing circumstances without involving large investments.
Also these measures will substantially simplify the stock keeping of such fittings, as only one type of housing is fit for all kinds of reflectors.
The present invention will be further elucidated with the help of the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view from underneath of a fitting according to the present invention;
FIG. 2 is a perspective view, partly broken away, of the fitting depicted in FIG. 1, but from above;
FIG. 3 is a perspective view, partly broken away, of a piece of profile to be used with the fitting according to the present invention;
FIG. 4 is a cross-sectional view according to the line IV--IV in FIG. 2;
FIG. 5 is a perspective view of a housing for connecting equipment, wherein the profile present above is partly broken away;
FIG. 6 is a perspective view from underneath of the upper plate of the housing for connecting equipment with the mounting plate being present therein.
FIG. 7 is a perspective view of a second embodiment of the fitting according to the present invention; and
FIG. 8 is a cross-sectional view of the embodiment shown in FIG. 7 according the line VIII--VIII.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The fitting depicted in FIG. 1 comprises a housing 1 for connecting equipment which is supported by a profile 2 extending above. The profile 2 supports a reflector 3. A lamp holder, not depicted in the drawing, is provided in the housing 1, and a lamp 4 is located in the lamp holder such that the lamp extends in the area of the reflector. By means of hooks, not depicted in FIG. 1, the profile 2 and thus the whole fitting is supported by a supporting rail 5 extending within the greenhouse to be luminated.
In the top view shown in FIG. 2 it is depicted how the profile 2 is supported by the supporting rail 5 by means of hooks 6. Therefore the profile 2 comprises a partly covered slot, wherein a square nut, not depicted in the drawings, is located at the location of each supporting hook 6. A bolt 8 is inserted in an aperture provided in each of the hooks 6 and the bolt 8 is screwed in the associated nut, so that the supporting hook 6 is fixed to the profile 2. This means of fixing allows the shifting of the hooks 6 in the longitudinal direction of the supporting rail 5, so that possible obstructions at the supporting rail can be avoided.
The reflector 3 comprises four hooks 9 which are screwed against reflector 3. These hooks 9 engage a rim provided in the profile 2, providing an attachment of the reflector 3 to the profile. The hooks 9 can, however, also be attached to the reflector 3 by means of adhesive or by means of rivets. The profile 2 is terminated at both sides by terminal pieces 10.
FIG. 3 shows a portion of the monolithic profile more in detail. The profile comprises flat plates 11 of equal size which are separated by a gutter 12. The plates 11 have such dimensions that they both extend over a part of the gutter 12, so that the gutter 12 comprises two rims 13 at its upper side. At both sides of the gutter a vertical strip 14 is provided which is terminated at its lower end by a rim 15.
The plates 11 are terminated by a bevelled piece 16, which ends in a vertical strip 14 of the connection line. Between the bevelled wall 16 and the rim 17 a rim 18 extends outwardly. At its inner side the rim 18 is terminated by a strip 19 extending downwardly.
Thus rims 15, 18 are developed for engaging the reflector hooks 9. As will appear in the following, these rims 15, 18 are also used for the attachment of the housing 1 for switch gear. The rims 13 within the gutter 12 are used for the attachment of suspension hooks 6 as has been described with the help of FIG. 2. Instead of the profile shown it is of course possible to use other profiles and to stay within the scope of the present invention.
In FIG. 4 it is clearly visible that the housing 1 for connecting equipment comprises an upper plate 20 and a lower plate 21. The upper plate 20 comprises hooks 22 for attaching the upper plate to the rims 15 of the profile 2. Both hooks 22 comprise a reinforcement rim 23.
The upper plate comprises at several cross-sections an internal reinforcement rim 24 extending perpendicular to the longitudinal direction and also several inner reinforcement rims 25 stretching in the longitudinal direction and provided at the upper side.
The transverse rims 24 comprise notches 26 at both lower ends, in which the upper rim of the lower plate is positioned. These notches are in some distance from the outer rim of the upper plate 24, so that between the upper rim 27 of the lower plate and between the lower rim 28 of the upper plate an airing channel 29 is provided at both sides of the housing over the full length thereof.
At the intersections of the rims 24 and 25 a number of bushings 30, which extend through the upper wall of the upper plate 20. These bushings comprise a central aperture, through which a mounting plate 32 can be provided against the upper wall of the upper plate 20 by means of parker screws 31, and such that some space remains therebetween.
From the perspective view of the housing 1 for connecting equipment as is shown in FIG. 5, it appears that the upper plate 20 comprises a number of apertures 33. Each of these apertures is surrounded by an upstanding rim 34 extending around it. Besides, the apertures 33 are provided such that they are completely covered at their upper sides by the profile 2. A number of hooks 22 are monolithic with one of the upper rims 34.
In FIG. 5 it is also visible how the reflector 3 has been attached to the profile 2 by means of reflector attachment profiles 43. In the embodiment shown these profiles 43 have been attached to the reflector by means of screws 35. This figure also shows that the neck 36 of the reflector 3 comprises a rim 37 to prevent water dripping from the reflector 3 from entering the housing 1.
FIG. 6 shows the inner side of the upper plate 20 of the housing 1 for connecting equipment. This figure shows how the mounting plate 32 comprises a folded part 38, at the back side whereof connecting means can be mounted for the connection of the power supply. Therefore swivels 40 have been provided in the head wall 39 of the upper plate. The auxiliary apparatuses, like a transformer, a starter, capacitors and the lamp holder are mounted on the mounting plate 32, and such that at least the heat producing components are on a substantial distance from both plates 20, 21 of the housing 1. This avoids that by radiation heat the plates melt or are disturbed. Further the mounting plate 32 comprises a number of apertures 42 to maintain a good circulation of air within the housing.
Herewith the remark is made that through the slit between both plates a good supply of air is secured, while, as a consequence of the holes in the mounting plate, a good circulation of air can take place within the housing and the air heated by the dissipation of the components can be released through the apertures 33 in the upper plate. This circulation of air is necessary as the housing has been made of plastic and through the heat of the dissipation of the components within the housing could melt or could burn. By securing a good circulation of air this danger is avoided.
By producing the housing of plastic, this is insulated according to class 2. As a consequence thereof the ground connection can be deleted.
As such fittings are often mounted in greenhouses the danger exists that with a random positioning of the apertures large amounts of water may enter the housing, which is of course undesired. Therefore the apertures have been provided such that the housing is at least sealed against dripping water according to the standard IP23. Thus the entering of a extravagant amount of water into the housing is avoided.
To simplify the mounting of such fittings these have to be joined beforehand, so that they can be mounted to the present suspension rail 5 with little handling. Then the lower plates 21 are removed, the cables are entered by means of the swivels 40, after which the cables are stripped and connected, after which the lower plates 21 can be positioned again. Herein it is of importance that the lower plates 21 can be released and mounted with little labour. Therefore the head wall 39 comprises two eyes 39a, in which hooks, not depicted in the drawing and connected with the lower plate 21 can engage. The reflector side of the lower plate can easily be mounted to the upper plate by means of a snap or screw connection.
The embodiment shown in FIG. 7 deviates initially from the embodiment shown beforehand in that the housing, in which the connecting apparatus have been provided, is much smaller. This relates to requirements for such housings; in several countries the choke belonging normally to connecting apparatus can be deleted -- relating to the requirements in vigour -- so that no space has to be reserved therefore in the housing 1. Whereas these chokes are rather bulky elements, the elimination thereof can substantially reduce the size of the housing one and the mounting plate provided therein.
The effect of a smaller housing resides not only in savings in material and the advantages related thereto but also in the fact that the housing is hit by less light and thus causes less shadow with normal sun light. This has a considerable consequence on the amount of light hitting the plants underneath.
Further, this embodiment deviates by the provision of an adapter or collar 53 as a connection between the housing 1 and the reflector 3. By using the collar 53 it becomes easy to use the housing 1 with several shapes of reflectors. For every other reflector 3 only the shape of the adapter 53 has to be adapted.
The adapter 53 comprises rims 44, fitting into slots 45 provided in the housing 1, so that a snap connection is developed and the adapter 53 is connected firmly with the housing 1. By providing several parallel groups the adapter can be mounted in several positions in the housing 1, so that it is fit for lamps with different lengths. Further, the reflector 3 is not any more connected to the suspension rail 2 as is the case in preceding embodiment, but is mounted to the adapter 53 by means of rivets 46. The profile 2 extends through into the adapter 53, so that the adapter is suspended from the profile 2.
The consequences thereof are that the mounting of the fittings is simplified considerably; beforehand the collars have already been riveted to the relevant reflectors, so that during mounting after the mounting of the housing 1 only the combination of the adapter 53 and the reflector 3 against the housing has to be provided by means of a simple snap connection.
Further, the housing 1 of this embodiment comprises a compartment 47 in which connection means have been provided for the connection of the fitting with a supply cable. The compartment can be locked by means of a lid 48, which is hooked at one side by means of two hooks 50, in apertures 49 in the wall 1 of the housing, while the other side of the lid is mounted by means of a snap connection 51. For release of pulling power of the cables a screw 52 has been provided. This simplifies the connection of the fitting according to this embodiment considerably.
Thus a fitting is provided which can be used in several situations, and can be manufactured at low cost and of which the mounting costs are low. | 4y
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BACKGROUND OF THE INVENTION
1. Technical Field of the Invention
The present Invention relates to hydrocarbon well stimulation, and more particularly to methods and compositions to remove (and more generally to transfer) fluid deliberately introduced into the subsurface. For instance, the methods and compositions of the present invention involve creating then exploiting a capillary pressure gradient at the fracture face to systematically induce fluid flow from the fracture into the formation (or from the formation into the fracture), thereby increasing effective fracture length, hence, improving conductivity.
This Application is one member of a family of patent applications by Hinkel and England, the Inventors of the present Invention, and assigned to Schlumberger Technology Corporation. The common feature of these Applications is that they are all directed to transferring fluids in the subsurface by non-hydraulic means. The other Applications in this family are, Enhancing Fluid Removal From Subsurface Fractures Deliberately Introduced Into the Subsurface, U.S. patent application Ser. No. 09/087,286; and, Novel Fluids and Techniques for Maximizing Fracture Fluid Clean-up, U.S. patent application Ser. No. 09/216,420. Each of these Applications is incorporated by reference in its entirety into the present Application.
2. The Prior Art
The present Invention relates generally to hydrocarbon (petroleum and natural gas) production from wells drilled in the earth. Obviously, it is desirable to maximize both the rate of flow and the overall capacity of hydrocarbon from the subsurface formation to the surface, where it can be recovered. One set of techniques to do this is referred to as “stimulation” and one such technique, “hydraulic fracturing,” is the primary, though not the exclusive subject of the present Invention.
The rate of flow or “production” of hydrocarbon from a geologic formation is naturally dependent on numerous factors. One of these factors is the radius of the borehole; as the bore radius increases, the production rate increases, everything else being equal. Another, related to the first, is the flowpaths available to the migrating hydrocarbon.
Drilling a hole in the subsurface is expensive—which limits the number of wells that can be economically drilled—and this expense only generally increases as the size of the hole increases. Additionally, a larger hole creates greater instability to the geologic formation, thus increasing the chances that the formation will shift around the wellbore and therefore damage the wellbore (and at worse collapse). So, while a larger borehole will, in theory, increase hydrocarbon production, it is impractical, and there is a significant downside. Yet, a fracture or large crack within the producing zone of the geologic formation, originating from and radiating out from the wellbore, can actually increase the “effective” (as opposed to “actual”) wellbore radius, thus, the well behaves (in terms of production rate) as if the entire wellbore radius were much larger. Hence, the hydrocarbon can move from the formation into and along or within the fracture and more easily to the wellbore.
Fracturing (generally speaking, there are two types, acid fracturing and propped fracturing, the latter of primary interest here) thus refers to methods used to stimulate the production of fluids resident in the subsurface, e.g., oil, natural gas, and brines. Hydraulic fracturing involves literally breaking or fracturing a portion of the surrounding strata, by injecting a specialized fluid into the wellbore directed at the face of the geologic formation at pressures sufficient to initiate and extend a fracture in the formation (i.e. above the minimum insitu rock stress). Morc particularly, a fluid is injected through a wellbore; the fluid exits through holes (perforations in the well casing) and is directed against the face of the formation (sometimes wells are completed openhole where no casing and therefore no perforations exist so the fluid is injected through the wellbore and directly to the formation face) at a pressure and flow rate sufficient to overcome the minimum insitu stress (also known as minimum principal stress) to initiate and/or extend a fracture(s) into the formation. Actually, what is created by this process is not always a single fracture, but a fracture zone, i.e., a zone having multiple fractures, or cracks in the formation, through which hydrocarbon can more easily flow to the wellbore.
In practice, fracturing a well is a highly complex operation performed with precise and exquisite orchestration of equipment, highly skilled engineers and technicians, and powerful integrated computers that monitor rates, pressures, volumes, etc. in real time. During a typical fracturing job, tens of thousands of gallons of materials are pumped into the formation at pressures high enough to actually split the formation in two, thousands of feet below the earth's surface.
A typical fracture zone is shown in context, in FIG. 1 . The actual wellbore—or hole in the earth into which pipe is placed through which the hydrocarbon flows up from the hydrocarbon-bearing formation to the surface—is shown at 10 , and the entire fracture zone is shown at 20 . The vertical extent of the hydrocarbon-producing zone is ideally (but not generally) coextensive with the fracture-zone height (by design). These two coextensive zones are shown bounded by 22 and 24 . The fracture is usually created in the producing zone of interest (rather than another geologic zone) because holes or perforations, 26 - 36 , are deliberately created in the well casing beforehand; thus the fracturing fluid flows down (vertically) the wellbore and exits through the perforations. Again, the reservoir does not necessarily represent a singular zone in the subterranean formation, but may, rather represent multiple zones of varying dimensions.
Thus, once the well has been drilled, fractures are often deliberately introduced in the formation, as a means of stimulating production, by increasing the effective wellbore radius. Clearly then, the longer the fracture, the greater the effective wellbore radius. More precisely, wells that have been hydraulically fractured exhibit both radial flow around the wellbore (conventional) and linear flow from the hydrocarbon-bearing formation to the fracture, and further linear flow along the fracture to the wellbore. Therefore, hydraulic fracturing is a common means to stimulate hydrocarbon production in low permeability formations. In addition, fracturing has also been used to stimulate production in high permeability formations. Obviously, if fracturing is desirable in a particular instance, then it is also desirable, generally speaking, to create as large (i.e., long) a fracture zone as possible—e.g., a larger fracture means an enlarged flowpath from the hydrocarbon migrating towards the wellbore and to the surface.
Yet many wells behave as though the fracture length were much shorter because the fracture is contaminated with fracturing fluid (i.e., more particularly, the fluid used to deliver the proppant as well as a fluid used to create the fracture, both of which shall be discussed below). The most difficult portion of the fluid to recover is that retained in the fracture tip—i.e. the distant-most portion of the fracture from the wellbore. Thus, the result of stagnant fracturing fluid in the fracture naturally diminishes the recovery of hydrocarbons. The reasons for this are both simple and complex. Most simply, the presence of fluid in the fracture acts as a barrier to the migration of hydrocarbon from the formation into the fracture. More precisely, the aqueous-based fluid saturates the pore spaces of the fracture face, preventing the migration of hydrocarbon into the same pore spaces, i.e., that fluid-saturated zone has zero permeability to hydrocarbon.
Indeed, diminished effective fracture length caused by stagnant fluid retained in the fracture tip is perhaps the most significant variables limiting hydrocarbon production (both rate and capacity) from a given well. This is particularly true for low permeability reservoirs (approx. <50 millidarcys). The significance of this stagnant fluid on well productivity is evidenced by the empirical observation well known to the skilled reservoir engineer that effective fracture lengths (the true fracture length minus the distal portion of the fracture saturated with fracturing fluid) are generally much less than the true hydraulically-induced fracture length. To achieve an increase in effective fracture length—so that it approaches the true fracture length—therefore involves removing stagnant fracturing fluid from the fracture particularly the tip.
The deliberate removal of fracturing fluid from the fracture is known as “clean-up,” i.e., this term refers to recovering the fluid once the proppant has been delivered to the fracture. The current state-of-the-art method for fracture clean-up involves very simply, pumping or allowing the fluid to flow out of the fracture—thus the fracture fluid residing in the tip must traverse the entire length of the fracture (and up the wellbore) to be removed from the fracture. The present Application is directed in part to an improved method—and compositions to execute that method—for clean-up of the fracture.
The most difficult task related to fracture clean-up is to remove the stagnant fracture fluid retained in the fracture tip (i.e., farthest from the wellbore). Often, a portion of the fracture may be hydraulically isolated, or “cut-off” so that the hydrocarbon flowing from the formation into the fracture completely bypasses this tip region, as shown in FIG. 2 . Ground level is shown at S. The direction of hydrocarbon flow is shown at 38 . Thus hydrocarbon flows—aided by the presence of the newly created fracture from the formation 40 into the fracture 42 —traverses the fracture until it gets to wellbore 10 where it is recovered at the surface. A similar flowpath is shown at 44 . These flowpaths can define two regions 46 , a producing region, and 48 , a nonproducing region at the fracture tip that is isolated from the rest of the fracture since no hydrocarbon flows through this portion of the fracture, thus no pressure gradient exists. This phenomenon (in addition to others) ensures that the stagnant fracture fluid will remain in the fracture tip rather than being displaced by producing hydrocarbon, which can occur in the region shown at 46 .
Generally speaking, creating a fracture in a hydrocarbon-bearing formation requires a complex suite of materials. In the case of conventional fracture treatments, five crucial components are required: a carrier fluid (usually water or brine), a polymer, a cross-linker, a proppant, and a breaker. (Numerous other components are sometimes added, e.g. fluid loss agents, whose purpose is to control leak-off, or migration of the fluid into the fracture face.) The first three component are injected first, and actually creates/extends the fracture. Roughly, the purpose of these fluids is to first create/extend the fracture, then once it is opened sufficiently, to deliver proppant into the fracture, which keeps the fracture from closing once the pumping operation is completed. The carrier fluid is simply the means by which the proppant and breaker (breaker can also be added to the fluid used to create/extend the fracture and commonly is) are carried into the formation. Thus, the fracturing fluid is typically prepared by blending a polymeric gelling agent with an aqueous solution (sometimes oil-based, sometimes a multi-phase fluid is desirable); often, the polymeric gelling agent is a solvatable polysaccharide, e.g., galactomannan gums, glycomannan gums, and cellulose derivatives. The purpose of the solvatable (or hydratable) polysaccharides is: (1) to provide viscosity to the fluid so that in can create/extend the fracture; and (2) to thicken the aqueous solution so that solid particles known as “proppant” (discussed below) can be suspended in the solution for delivery into the fracture. Again, the purpsoe of the proppant is to literally hold open or prop open the fracture after it has been created. Thus the polysaccharides function as viscosifiers, that is, they increase the viscosity of the aqueous solution by 10 to 100 times, or even more. In many fracturing treatments, a cross-linking agent is added which further increases the viscosity of the solution by cross-linking the polymer. The borate ion has been used extensively as a crosslinking agent for hydrated guar gums and other galactomannans to form aqueous gels, e.g., U.S. Pat. No. 3,059,909. Other demonstrably suitable cross-linking agents include: titanium (U.S. Pat. No. 3,888,312), chromium, iron, aluminum and zirconium (U.S. Pat. No. 3,301,723).
The purpose of the proppant is to keep the newly fractured formation in that fractured state, i.e., from re-closing after the fracturing process is completed; thus, it is designed to keep the fracture open—in other words to provide a permeable path (along the fracrture) for the hydrocarbon to flow through the fracture and into the wellbore. More specifically, the proppant provides channels within the fracture through which the hydrocarbon can flow into the wellbore and therefore be withdrawn or “produced.” Typical material from which the proppant is made includes sand (e.g. 20-40 mesh), bauxite, man-made intermediate-strength materials and glass beads. The proppant can also be coated with resin (which causes the resin particles to stick to one another) to help prevent proppant flowback in certain applications. Thus, the purpose of the fracturing fluid generally is two-fold: (1) to create or extend an existing fracture through high-pressure introduction into the geologic formation of interest; and (2) to simultaneously deliver the proppant into the fracture void space so that the proppant can create a permanent channel through which the hydrocarbon can flow to the wellbore. Once this second step has been completed, it is desirable to remove the fracturing fluid (minus the proppant) from the fracture—its presence in the fracture is deleterious, since it plugs the fracture and therefore impedes the flow hydrocarbon. This effect is naturally greater in high permeability formations, since the fluid can readily fill the (larger) void spaces. This contamination of the fracture by the fluid is referred to as decreasing the effective fracture length. And the process of removing the fluid from the fracture once the proppant has been delivered is referred to as “fracture clean-up.” For this, the final component of the fracture fluid becomes relevant: the breaker. The purpose of the breaker is to lower the viscosity of the fluid so that it is more easily removed fracture. Nevertheless, no completely satisfactory method exists to recover the fluid, and therefore prevent it from reducing the effective fracture length. Again, fluid recovery after delivering the proppant to the fracture represents one of the major technological dilemmas in the oilfield services field. The instant Invention is directed primarily to methods for recovering the fracturing fluid once the fluid has successfully delivered the proppant to the fracture.
Diminished effective fracture length (EFL) caused by fracture fluid retention in the fracture is an empirically demonstrable problem that results in substantially reduced well yields. The EFL can be calculated by production decline and pressure transient analysis; values obtained this way can then be compared with the true fracture length obtained using standard geometry models. EFL values of about one-half of the actual fracture length are common.
Essentially, techniques for fracture clean-up, which again, refers to recovering the proppant-less fluid from the fracture, often involves reducing the fluid's viscosity as much as practicable so that it more readily flows back towards the wellbore. Again, the goal is to recover as much fluid as possible, since fluid left in the fracture reduces the effective fracture length. Among the most troublesome aspect of fluid recovery, or clean-up is recovering that portion of the fluid at the very tip of the fracture.
The methods for fracture fluid clean-up taught in the prior art all involve removing the fracturing fluid through the same route by which the fluid was introduced into the fracture—i.e., by flowing or pumping the fluid back through the wellbore then to the surface where it is removed. The disadvantages of this method are obvious. For one thing, the fluid must traverse the entire length of the fracture—a distance often over 1000 feet in low permeability formations. Moreover, clean-up this way is expensive and time-consuming, and rarely results in effective clean-up, i.e., fluid often remains in the fracture tip, thus decreasing the effective fracture length. Indeed the time-honored empirical observation is that the effective fracture length is about 50 to 60% of the fracture length—after clean-up. The method of the present Invention is directed to a method of fluid removal not involving traversal of the fracture length and up the wellbore. Instead, the fluid is removed according to the present Invention by inducing fluid flow into the fracture faces or orthogonal to the conventional flowpath.
Although the system of the present Invention is novel in the art, others have disclosed the movement of fluids in subsurface environments by other non-hydraulic means, though not in a fracturing context. Eric van Oort, et al. at Shell in a series of SPE papers and U.S. Pat. No. 5,686,396, have investigated the problem of shale destabilization during drilling. E.g.: Eric van Oort, et al., Physico-Chemical Stabilization of Shales, SPE 37263; and Eric van Oort, et al., Manipulation of Coupled Osmotic Flows for Stabilization of Shales Exposed to Water-Based Drilling Fluids, SPE 30499. Jay P. Simpson, Studies of the Effects of Drilling Fluid/Shale Interactions on Borehole Instability, GasTIPS, 30, Spring 1997.
These authors/inventors posit that the economically devastating problem of shale instability—which is responsible for, among other things, stuck pipe due to well caving and collapse, cementing failures, and lost circulation—is caused by migration of low-solute fluid (i.e., the drilling fluid or “mud”) into the surrounding shale. This movement occurs in response to a chemical potential gradient—i.e., the solvent in low-solute fluid moves to the high-solute fluid contained in the shale pore spaces. The result is that the shale surrounding the borehole can take up/absorb drilling fluid until it literally bursts—i.e., the outward stress exerted by the imbedded fluid overcomes the shale's intrinsic strength—with consequent problems for the contiguous wellbore. This unusual behavior of shale is a direct consequence of its ability to behave as a selectively permeable membrane (i.e., selectively permeable to water in preference to solutes).
U. S. Pat. No. 5,686,396 discloses a method for improving the osmotic efficiency of shale during the drilling process. More specifically, the method involves adding compositions to the drilling fluid so that the solute content of the drilling fluid more nearly matches that of the contiguous shale system. This way, the invasion of drilling fluid into the surrounding shale system is minimized. Again, the essential physico-chemical concepts relied upon by the inventors of the '396 patent are related to those relied upon in the present Invention; nevertheless, the application (drilling versus stimulation) and actual problem to be solved (keeping fluid out of the shale versus deliberately directing fluid into the shale) are drastically different. Therefore, the van Oort references, including the '396 patent, are directed to a different problem in an entirely different setting. Finally, the van Oort references only disclose (or suggest) exploiting indigenous membrane systems—none of these references teaches deliberately creating a capillary pressure gradient in the subsurface. The present Invention is directed in part to the creation of such systems.
More particularly, the phenomenon of capillary imbibition has been intensively studied by reservoir scientists to better understand hydrocarbon movement in the subsurface. See, e.g., C. J. Radke, et al., A Pore-Level Scenario for the Development of Mixed Wettability in Oil Reservoirs, SPE 24880. The physico-chemical principles that underlie the phenomenon is described for instance, in, R. Lenormand, et al., Modeling the Diffusion Flux Between Matrix and Fissure in a Fissured Reservoir, SPE 49007; and, C. Murat, et al., An Examination of Countercurrent Capillary Imbibition Recovery from Single Matrix Blocks and Recovery Predictions by Analytical Matrix/Fracture Transfer Functions, SPE 49005; both of these papers are hereby incorporated by reference in their entirety into the present Application, and in particular those portions of the papers discussing the general phenomenon of capillary imbibition. The concept of relative permeability also been applied to stimulation—the domain to which the present Invention is directed—though in a substantially different application, namely conformance control. Dalrymple, et al. in Results of Using a Relative-Permeability Modifier with a Fracture-Stimulation Treatment, SPE 49043, investigated a novel relative permeability modifier—actually generated in situ—to seal off zones from water intrusion while still permitting hydrocarbon flow (i.e., a disproportionate permeability reduction). The authors state that the mechanism by which the permeability modifier operates is based on lining the pore-throat regions, thereby acting as a brush or micro-valve, permitting hydrocarbon intrusion but not water movement. The Dalrymple paper is not directed to removing spent fracturing fluid (clean-up) but rather to conformance control.
SUMMARY IF THE INVENTION
Like the other inventions in this family of patent applications by Hinkel and England, the present Invention is a part of our broader program to devise novel means, premised on non-hydraulic mechanisms, to transfer fluid, particularly fracturing fluid, contained for instance, in a fracture tip, ultimately for the purpose of increasing fracture conductivity and therefore hydrocarbon production.
The present Invention is directed to increasing production of hydrocarbon (oil & gas) from underground wells. In particular, the present Invention fits within the group of techniques known as “stimulation.” One stimulation technique is hydraulic fracturing, which involves pumping a fluid into the wellbore at sufficient pressures to actually fracture the formation and therefore increase the effective wellbore radius, which in turn will increase hydrocarbon production. The problem is that, quite ironically, the fluid used to fracture the formation remains in the fracture and acts as a barrier to putative hydrocarbon migrating into the fracture towards the wellbore. Hence, methods to remove this fluid—particularly that fraction that resides in the fracture tip (the region farthest away from the wellbore)—are of particular interest. Again, the conventional wisdom (as well as common sense) teaches that this recalcitrant fluid remaining in the fracture tip must be removed by somehow forcing it to flowback in the direction of the wellbore (along the length of the fracture) and where it can be recovered at the surface.
Generally, speaking, this method has not proven effective—as evidenced at least in part by the fact that the effective fracture length (fluid-free portion of the fracture) is about half of the actual fracture length is, in probably most cases. The present Invention is premised upon removing the spent fracturing fluid by transferring it transverse to the fracture, or parallel to the wellbore, into the adjacent fracture face. According to methods of the present Invention, the mechanism by which the fluid is transferred is capillary imbibition. To accomplish this, a capillary pressure gradient must be deliberately established—that is, a region of high capillary pressure juxtaposed with a region of low pressure. These two zones must be in contact, yet they must be immiscible; moreover, since it is desirable to move the fluid from the fracture into the formation, the region of high capillary pressure must reside in the formation, and the region of low pressure in the fracture.
The creation of two at least partially, immiscible phases to create a capillary pressure gradient is the signature of the invention. To do this in the case of a water-wet formation, involves pumping a (substantially) non-wetting fluid following by a (substantially) wetting fluid—so that they are at least partially immiscible. Immiscibility is essential to establish the gradient or discontinuity. Thus, the first fluid may be for instance, diesel oil that has been gelled so that is has sufficient viscosity to initiate and extend the fracture. At this point, a fracture treatment of the present Invention looks identical to an ordinary fracture treatment—indeed gelled oil is a common pad fluid, though it was much more common prior to water-based fluids, which are predominantly used today. As in an ordinary fracturing treatment, the pad fluid (in this case, gelled diesel oil) is designed to completely leak off into the formation; this complete leak-off coincides precisely with the termination of the proppant stages, or pumping a slurry containing proppant, so that the newly created fracture is propped open. For well treatments of the present Invention, the proppant slurry stage varies markedly from conventional treatments in that according to the present Invention, the proppant slurry stage is a wetting fluid—i.e., hence, an aqueous-based fluid, rather than a hydrocarbon-based fluid. According to conventional practice, the two types of fluids (hydrocarbon and aqueous) are not combined in a single treatment; in other words, the pad and proppant-slurry stages are conventionally either both aqueous or both non-aqueous. (Except that occasionally, small amounts of, e.g., diesel oil are added to an aqueous pad stage as a water control measure or for instance, the first stage might be foamed with CO 2 or N 2 , followed by an aqueous-based proppant delivery fluid). Hence, the present Invention varies markedly from conventional treatments, not just in theory, but in actual practice.
The present Invention is based upon the following physico-chemical principles. Imagine a beaker filled three-quarters full with water. Next imagine that a hollow glass tube (“a capillary tube”) open at both ends and having an inside diameter of about 0.1″ is placed into the beaker near the center. What one would observe is that the water in the beaker would spontaneously enter the tube from the bottom and travel up the tube to a level higher than the water level in the beaker. This rise in height is due to the attractive forces—i.e., adhesion tension—between the tube and the water; in other words, the adhesion tension is the force that tends to pull the liquid up the wall of the tube. This phenomenon is known as capillary imbibition, and the difference between the water level in the beaker and the water level in the tube is a measure of the system's capillary pressure.
Next, suppose that a hollow glass sleeve is placed inside the capillary tube, so that the inside surface of the capillary tube is in contact with the outside surface of the sleeve (so that no fluid can enter the space between them). The effect of inserting the sleeve is to decrease the radius of the capillary tube. And the result of a decreased radius is that the water will rise to an even higher level in the capillary tube.
Thus, capillary imbibition is a phenomenon by which fluid can be moved. Hinkel and England have discovered that this principle can be exploited to transfer fracturing fluid from a subsurface fracture into the contiguous formation and therefore achieving fracture clean-up. The system of the present Invention thus can be viewed conceptually—though very crudely—as a means to “place the sleeve into the capillary tube ” and thereby deliberately transfer fluid in the subsurface.
The basic equation describing capillary pressure is given below: P c = 2 γ lv cos θ r c
where P c is the capillary pressure, which is the quantity which we wish to maximize; γ lv is the liquid-vapor intcrfacial tension, that is, it describes the tension between the liquid phase and the overlying contiguous phase; theta (θ) is the angle formed between a horizontal reference and the meniscus; and r c , is the radius of the capillary tube.
Therefore, one can readily observe that, as r c is decreased, then P c , or the capillary pressure increases. Returning to the beaker model—decreasing the radius by inserting the sleeve increases P c . From this equation, one can also see that as the interfacial tension between the two solid and liquid is increased, capillary pressure rises.
Returning to the beaker model, this system can be though of as having two separate capillary pressures. The beaker filled with water has a capillary pressure, which can be given by the formula above. This pressure is relatively low since r c , or the radius of the beaker is “large.” The capillary tube also has a capillary pressure that is much larger than the beaker's, due largely to its smaller radius. Thus, capillary imbibition can be though of as the result of bringing into contact two systems having unequal capillary pressures. The result is fluid movement—or imbibition—from the low-pressure system to the high-pressure system. The present Invention is a direct application of these principles in a subterranean environment.
A hydrocarbon-bearing formation in the subsurface consists of rock, such as sandstone that is permeable—that is, it has void spaces in which the oil resides. Looked at in cross section, a portion of the formation rock looks similar to a cross-section of a bundle of capillary tubes. Thus, one can imagine that the movement of hydrocarbon in a subterranean environment can be modeled as capillary bundles. And indeed, this is a common paradigm to model subsurface fluid movement.
The subsurface environment of interest is a fracture deliberately induced into the subsurface. This fracture—actually a large void in the formation—is saturated with fracturing fluid. In contact with that fracture is the hydrocarbon-bearing formation. To assist in understanding the Invention, the fracture can be though of as the beaker of water, the fracturing fluid as the water in the beaker, and the formation as the capillary tube. This analogy, though rough, is appropriate since the fracture is a large, essentially open fluid-containing reservoir, and the formation, as we have already discussed is frequently modeled as a bundle of capillary tubes.
To continue the analogy, we stated earlier that when two systems having unequal capillary pressure are brought into contact, the fluid will migrate from the low-pressure system to the high-pressure system—i.e., water will travel up the capillary tube. Thus, in the case of a fracture in the subsurface, the two systems are: (1) the fracture (the beaker) which is at very low capillary pressure since it essentially an “open” system like the beaker; and (2) the formation (the capillary tube). Empirically speaking, this pressure differential is insufficient to move fluid from the fracture into the formation. If it were, then fracture clean up would be routinely observed—but it is not. The pressure differential can be increased either by decreasing the capillary pressure of the fracture or by increasing the capillary pressure of the formation. According to the present Invention, if this pressure differential were increased—i.e., if the high-pressure system is made even higher pressure (like putting the sleeve inside the capillary tube)—then fluid will more readily flow from the fracture into the formation. Conceptually, this is like placing the sleeve inside the capillary tube—in effect, increasing capillary pressure by decreasing pore radius. This is done, in accordance with the present Invention by injecting into the formation, a non-wetting fluid, such as diesel fuel. This fluid coats the inside diameters of the rock pores, thus decreasing the inside diameters of the rock pores, and therefore increasing the capillary pressure of the system. Again, this system—the hydrocarbon-bearing formation—is in contact with the fracture, and therefore, the fracturing fluid will migrate, in response to the capillary pressure differential, from the low-pressure region (the fracture) to the high-pressure region (the formation). Thus, fracture clean-up can be achieved by transferring fluid from the fracture into the formation by capillary imbibition, which was achieved by creating then exploiting a capillary pressure gradient between the two subsurface phases in contact.
Referring now to FIG. 3, a tip region is shown at 48 ; this tip has stagnant fluid. First, a high-capillary pressure region A is created in the formation immediately adjacent to the fracture, by injecting the appropriate fluid into the wellbore and allowing it to flow into the fracture and eventually migrate from the fracture into the formation. The interface between the formation and the fracture is shown at 50 . This interface divides two regions: a region A having an (artificially induced) region of high capillary pressure and a region B having low capillary pressure. They are in contact at this interface 50 . A consequence of fluid contact between two regions having different capillary pressures (i.e., a capillary pressure discontinuity) is that fluid will migrate from the low-pressure region B to the high-pressure region A, according to the flow path 56 . The fracture flows along the flowpath shown at 56 . Again, this flowpath 56 for fracturing fluid removal is drastically different from the traditional flowpath depicting fluid removal of the prior art, shown at 58 .
Again, the current state-of-the-art for removal of fracture fluids from a fracture (i.e., “fracture clean-up”) teaches that the fluid must be removed through the same path through which the fluid came in: by traversing the entire length of the fracture (which in low-permeability formations may be over 1000 ft) then moving the fluid up the wellbore. Hence, regardless of the particular clean-up method employed, one feature common to all of those methods is that in every instance, the fluid is removed through the same path. The superficial appeal of this approach is difficult to argue with at first, since the fracture represents an open channel through which the fluid can move, and when the well is produced, fluid will travel naturally through the fracture towards the wellbore, up the wellbore, and to the surface.
The present Invention represents a drastic departure from this virtually uncontested orthodoxy. The essence of the present Invention is a method for removing the fracture fluid out of the fracture by deliberately directing or channeling the fluid towards the fracture face and into the formation. Conventional practice teaches that fouling of the fracture faces with fracture fluid (“fracture damage”)—which contains, among other things, high molecular weight viscous organic polymers—is highly undesirable and should generally be avoided, and in no event intentionally induced. Put another way, the method of the present Invention is premised, in part, on an unusually counterintuitive insight—an insight that, until made, would discourage the skilled artisan from conceiving of the present Invention. This insight is that, in certain instances, for well productivity, increased effective fracture length is more important than the consequent formation damage, or loss in permeability of the fracture faces. In other words, the method of the present Invention will often result in deliberate damage to the fracture face, i.e., the fracture fluid residue (“filtrate”) will plug portions of the face thus rendering it less permeable to hydrocarbons. Yet the present Invention is premised in part on the insight that, under certain conditions, decreased production due to fracture face damage is more than offset by increased production gained by increasing the effective fracture length (by removing fluid from the tip of the fracture).
Thus, according to the present Invention, while fracture face damage may lower permeability to hydrocarbon, and therefore inhibit production, the obverse benefit from moving the fluid into the fracture face is that the fluid is removed from the fracture itself, thus increasing the effective fracture length. This increase in effective fracture length can often enhance well production even accounting for the offset detriment of fracture face damage.
Therefore, the motivation to remove fracture fluid by intentionally directing it into the fracture faces is essentially absent in the art. Yet once that motivation is provided, what is needed is a cost-effective method to move the fluid into the fracture face. Thus the present Invention is directed to a method for removing the fracture fluid by forcing it into the fracture face. More specifically, the present Invention is directed to a method for fracture clean-up by creating and/or enhancing a capillary pressure gradient (or discontinuity between the stagnant fracturing fluid remaining in the fracture and the pore fluid in the contiguous formation. This gradient, once created, is then exploited to transfer the fracturing fluid into the formation along the gradient.
One advantage of the present Invention is that it results in increased effective fracture length, which in turn means that the rate of production and the production capacity will be enhanced. The rate of production is increased due to the additional flowpaths available to the hydrocarbon; and the overall production capacity is increased due to the enlarged drainage area (the region within the hydrocarbon-bearing formation from which the hydrocarbon is effectively extractable).
A second advantage of the present Invention is that since the effective fracture length is increased, the drainage area concomitantly increases, which in turn means that less wells need to be drilled in order to recover a given amount of hydrocarbon from the formation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a stylized cross-sectional view of a typical fracture zone in a subsurface formation.
FIG. 2 depicts a cross-sectional view of a stylized fracture modified to show certain essential features of a typical fracturing operation.
FIG. 3 depicts a cross-sectional view of a stylized fracture modified to show certain essential features of the present Invention.
FIG. 4 shows data obtained from laboratory experiments conducted to obtain a velocity parameter for capillary imbibition. This parameter will be used to model subsurface fluid movement attributable to imbibition.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Several preferred embodiments of the present Invention will now be described. The methods and compositions of the present Invention are conceptually inseparable, hence both will be discussed together.
Again, the essence of the present Invention is the deliberate transfer of selected components of a fluid from one discrete subterranean compartment to another by creating or enhancing a capillary pressure discontinuity by introducing a non-wetting fluid into the formation contiguous with and in contact with the fracture. Thus, the aqueous fracturing fluid will be imbibed by the high-capillary pressure region, therefore transferring fracturing fluid from the fracture and into the formation, and therefore increasing effective fracture length.
The method of the present Invention is readily operable without limitations as to the type of fracturing fluid or breaker. Virtually all fracturing fluids contain a carrier fluid which is conventionally an aqueous liquid, and a viscosifying polymer. The conventional hydratable polymers are: guar, hydroxypropyl guar, carboxymethyl guar, carboxymethylhydroxypropyl guar, hydroxyethyl cellulose, carboxymethylhydroxyethyl cellulose, hydroxypropyl cellulose, and xanthan and other synthetic polymers. Additionally, the fracturing fluid will generally also contain one or more additives such as surfactants, salts (e.g., potassium chloride) anti-foam agents, bactericides, and cross-linking agents for the polymeric thickener.
The method of the present Invention is also operable, for instance, with ClearFRAC™, a polymer-free fracturing fluid, developed and sold by Schlumberger Dowell. ClearFRAC is a Schlumberger trademark applied to viscoelastic surfactant-based fracturing fluids. Such viscoelastic surfactant-based fracturing fluids are disclosed and claimed in: U.S. patent application Ser. No. (unassigned) (Compositions Containing Aqueous Viscosifying Surfactants and Methods for Applying Such Compositions in Subterranean Formations), by Qu, et al., filed Feb. 23, 1999; U.S. patent application No. (unassigned) (Method of Fracturing Subterranean Formations), by Card, et al., filed Dec. 23, 1998; U.S. patent application Ser. No. 09/166,658 (Methods of Fracturing Subterranean Formations); U.S. patent application Ser. No. 08/865,137 (Methods for Limiting the Inflow of Formation Water and for Stimulating Subterranean Formations); U.S. Pat. patent application No. 08/727,877 (Elongated or Wormlike Micelles in Fracturing); U.S. Pat. No. 5,551,516 (Hydraulic Fracturing Process and Composition); and U.S. Pat. No. 5,258,137 (Viscoelastic Surfactant Based Foam Fluids).
Likewise, the method of the present Invention is readily operable without limitations as to the type of breaker. Again, breakers are added to the fracturing fluid mixture to “break” or destroy/diminish the viscosity of the fracturing fluid (the matrix carrying the proppant) so that this fluid is more easily recovered from the fracture during clean-up. Examples of breakers suitable for use in the method of the present Invention include enzymes (oxidizers and oxidizer catalysts). Additionally, the breakers can be encapsulated to delay their release, according to U.S. Pat. No. 4,741,401, herein incorporated by reference, issued to Walles, et al. and assigned to Schlumberger Dowell.
Despite the firm theoretical underpinning for the present Invention, and despite the prior studies demonstrating fluid movement in subsurface environments in response to other non-hydraulic means (e.g., drilling fluids into shales by osmotic flow), whether fracture clean-up can actually occur to any appreciable degree according to the present Invention is not obvious and has not to this point been demonstrated to a reasonable engineering probability to one skilled in the art. Obviously any computer simulation designed to model fluid movement in a fractured subsurface formation is only as reliable as the choice of value for the capillary imbibition flow parameter. Likewise, in laboratory experiments intended to demonstrate the efficiency of fracture fluid removal from a subsurface fracture are limited by the inability to reproduce actual subsurface conditions. Therefore, one generally preferred way to assess the efficiency with such a downhole technique is to rely upon a computer model which simulates—as much as possible—the real world conditions. Here, the flow parameter input into the model's algorithm (in this case, the parameter depicting flow attributable to capillary imbibition, or flow according to a capillary discontinuity) are determined by laboratory experiment then input into a numerical simulator of fracture clean-up.
Thus, the following examples are intended to further illustrate the present Invention—i.e., they demonstrate the effectiveness of the methods and compositions of the present Invention for removing fluid from a fracture tip. The examples that follow are separated into three sets. The first set depicts laboratory experiments designed to determine, among other things, realistic empirical parameters to describe flow due to capillary presssure, or fluid flow driven solely by a capillary pressure discontinuity. Once those parameters are determined by experiment, they are then incorporated into a simple mathematical model to mimic fluid removal from a fracture. This model is very simple and is based on parameters and equations well known to the skilled artisan. The model results predict the effectiveness of the present Invention in removing fluid from a fracture—again, based on experimentally derived values for the key parameter—flow due to capillary imbibition. These results are presented in the second example. Thus, the two examples taken together show the efficacy of the present Invention in a model environment intended to mimic actual subsurface conditions—the model simulates conditions in the subsurface, based on a realistic osmotic flow parameters determined experimentally. The third set of examples presents designs of fracturing treatments based on the present Invention.
Example 1
Determination of an Empirically Based Parameter for Fluid Flow Attributable to Capillary Pressure
This Example records laboratory studies performed to determine a realistic parameter for the rate of fluid movement attributable to imbibition. Once this parameter is obtained, then it can be incorporated into a numerical simulator of fracture fluid movement. The output of these simulations is the total time require for a certain volume of fluid (e.g., fracturing fluid) to transfer from the fracture to the formation (i.e., “clean-up”).
We conducted laboratory studies to determine the rate of water transport through porous media due to imbibition. Specifically, these studies involved monitoring the volume of nitrogen—i.e., the non-wetting fluid—displaced from an Ohio sandstone core, upon contact with water (the wetting fluid). The sandstone core was initially saturated with deionized water and then saturated with nitrogen by injecting the gas for two hours at 150 psi. The results are shown in FIG. 4 .
These data show a delay of about 40 hours in water transport as it begins to invade the sandstone. These data also show that the rate of imbibition is relatively constant over the range of 50 to 1 10 hours and begins to plateau after about 110 hours. This plateau behavior is most likely due to the transport of sufficient water to equilibrate the capillary pressures of the wetting (water) and non-wetting (nitrogen). This plateau corresponds to the movement of 1.5 ml of water into the sandstone core; this represents less than about 2% of the total pore volume.
Finally, from these studies, a volume flux due to imbibition is obtained, which is 0.00045 cm/hr.
Example 2
Numerical Simulation of Fracture Fluid Clean-up Based on the Empirically Based Flow Parameter
Having obtained this volume flux parameter, we now perform a numerical simulation of fracture clean-up (the movement of spent fracturing fluid out of the fracture and into the formation), based on the laboratory-derived parameter.
To ensure that the results from the computer simulation mimic as closely as possible, real-world conditions, the parameter used to describe flow due to capillary imbibition (J v , the volume flux due to capillary pressure-induced flow)—the key parameter in the model—was obtained by laboratory experiment, according to Example 1. Put more simply, the study presented in this Example purports to answer the following question: having determined an experimentally based value for the capillary pressure flux, is this flux significant enough to actually move appreciable volumes of fluid from a subsurface fracture tip? Or: can the present Invention be employed to actually clean-up a fracture?
Thus, in the model described in this Example, the hydraulic (or D'Arcy) flow is set to zero—therefore any flow of the fracturing fluid held in the fracture must be due to capillary imbibition.
Referring again to FIG. 3, the fracture tip, 48 —i.e., the distal portion of the fracture hydraulically isolated from the remainder of the fracture and thus retaining stagnant fracturing fluid that prevents the flow of hydrocarbon through that portion of the fracture—is the portion of the fracture from which it is desired to remove fluid.
The constant parameters input into the computer simulation are: fracture height (100 ft.), length (1000 ft.), fracture vertical width (0.2 in.); and permeability (8 millidarcy). Each of the values mimics real-world values. The left-most column of Table 1 recites different intervals of the total fracture length in 50 ft intervals—from 0 (at the wellbore) to 1000 ft., the distal-most portion of the fracture. Thus, the entire fracture is, in this computer simulation, discretized into 50 ft. cells. The next column gives the fracture width side-to-side (this is assumed to diminish with increasing distance from the wellbore). The next column calculated from the following equations:
V=del x*h*w
ave
where del x is the length of the differential fracture portion (in these calculations always equal to 50 ft.), w ave is the average width over the length of that portion of the fracture, and h is the fracture height. “V” represents the volume of fluid removed from that 50 ft. portion of the fracture—the total volume is shown at the bottom of each column. The rows from 650 ft.—1000 ft are intended to represent the fracture tip—i.e., that portion of the fracture from which it is difficult to remove the fracture fluid, due to the distance from the wellbore and due to the hydraulic isolation of that portion of the fracture. Thus, the numbers inside the box are intended to indicate the efficacy of the present Invention in removing fluid from the fracture tip. The two final columns display the time that it takes to remove the fluid in that portion of the fracture to the immediate left (assuming this entire fracture volume were completely filled with fluid).
In a separate set of experiments, plausible rates for diffusion were determined by conventional laboratory methods. The purpose of this experiment was to verify that diffusion would occur quickly enough relative to the experimentally determined capillary imbibition rate—in a typically subsurface environment. If solute diffusion occurs too slowly, then a solute-depleted region will occur near the interface—this local gradient near the interface is far less than the overall gradient beyond the region immediately adjacent to the interface. Experiments performed in connection with this Patent Application have determined that in fact, diffusion is much faster than the rate of capillary imbibition, and therefore the solute gradient is quickly reestablished or replenished at the interface as the solute concentration is depleted by the transfer of water from the fracture.
Thus, (referring to Table 1) at fracture cell, 650-700 ft., 1309 liters of fluid were removed (from the fracture into the contiguous formation) in a little over 14 days. The time is calculated using the following equation:
t=V/Q=V /(2 *Ac′*J v )= V /(2 *del x*h*J v )
J v is the volume flux—i.e., that parameter obtained from the laboratory experiments in Example 1above.
Also, according to Table 1, it took 5.63 days to remove all of the fluid remaining in the distal-most tip of the fracture (950-1000 ft.). Again, this number represents the migration of fracturing fluid from the fracture tip into the adjacent formation—and this fluid movement is due solely to a capillary imbibition, since the other flow term, hydraulic flow, is set to zero. Therefore, the data presented in Table 1 demonstrates to one skilled in the art that capillary imbibition, if properly exploited, is a significant source of the total flow in a subsurface fracture environment—as evidenced by the fact that, for instance, the last 100 ft. of the fracture was cleaned-up—i.e., the stagnant fracturing fluid was completely removed from the fracture into the formation by osmotic flow—in about two weeks hours. To one skilled in the art, this number is significant since fracture clean-up can take days, or weeks, or months—and even after that period of time, the fluid in the tip is still not removed. Thus, the present Invention is a viable system for removing stagnant fracturing fluid from a subsurface fracture.
The efficacy and reliability of the method and composition of the present Invention must be verifiable by the on-site petroleum engineer and other on-site personnel skilled in well stimulation. Indeed, this is easily accomplished by several means. For instance, the present Invention will result in increased fluid removal from the fracture, and therefore, increased effective fracture length. Thus conventional techniques used to measure effective fracture length can be employed to assess the efficacy of the method and composition of the present Invention. Such methods include pressure transient analysis. The effective fracture length can be compared with the actual fracture length determined by standard fracture geometry models.
Again, in this numerical study, the only source of fluid transport is imbibition. No other sources of fluid movement are considered—e.g., hydraulic means, osmosis, etc.
TABLE 1
Numerical Simulation of Fluid Movement Based on a Laboratory-
Derived Velocity Parameter for Imbibition
fracture
length
fracture
volume of
segment (ft)
width (in)
fluid (ml)
time (hr)
time (days)
0
0.200
—
—
50
0.194
2,323,991
608.16
25.34
100
0.188
2,251,713
589.24
24.55
150
0.181
2,177,852
569.91
23.75
200
0.175
2,102,280
550.14
22.92
250
0.168
2,024,850
529.87
22.08
300
0.161
1,945,391
509.08
21.21
350
0.154
1,863,703
487.70
20.32
400
0.147
1,779,552
465.68
19.40
450
0.140
1,692,654
442.94
18.46
500
0.132
1,602,677
419.40
17.47
550
0.124
1,509,168
394.40
i6.46
600
0.115
1,411,623
369.40
15.39
650
0.107
1,309,341
342.64
14.28
700
0.097
1,201,398
314.39
13.10
750
0.087
1,086,510
284.32
11.85
800
0.076
962,785
251.95
10.50
850
0.064
827,213
216.47
9.02
900
0.050
674,370
176.47
7.35
950
0.033
491,903
128.72
5.36
1000
0.00
195,538
51.17
2.13
29434502
385.13
16.05
As evidenced by Table 1, about 14 days is required to remove fluid from this fracture tip, provided that the only movement is due to capillary imbibition.
Example 3
Preferred Fracture Treatment Design
In Example 1, we obtained a laboratory-based flow parameter for capillary imbibition. In Example 2, we used that parameter in a numerical simulator of fluid movement in a fracture to model fracturing fluid clean-up. These examples demonstrate that fracturing treatments could be designed in accordance with the present Invention. Those treatment designs are presented in this Example.
In each example, we assume that the formation is a water-wet formation, as in fact most are. A typical hydraulic fracturing treatment can be conveniently divided into three phases: (1) the pad stage; (2) the proppant slurry stage; and (3) a flush. In a typical fracturing treatment, a pad fluid is first pumped—the purpose is to initiate and propagate (extend) the fracture. A second purpose (not always desired or achieved) is to seal the fracture face to prevent fluid loss as additional fluid is pumped into the fracture during later stages. Generally, though not always, the pad is pumped in a single stage. Next, the proppant slurry stages are pumped. This phase is generally divided into several stages—each stage characterized by different volumes an different proppant concentrations. Finally, a flush is performed, which is generally just a single stage.
In the case of the present Invention (again, assuming a water-wet formation) the pad stage is a non-wetting fluid and the proppant stages are wetting fluids. By contrast, conventional fracturing treatments are performed using either wetting fluids as the pad and proppant slurry stages, or conversely, both phases are non-wetting fluids. Fracturing treatments designed according to the present Invention are comprised of a non-wetting pad and wetting proppant slurry.
The idea behind this unusual design is to establish a capillary pressure gradient at the fracture face (defined by the formation on one side and the open fracture on the other). Such a gradient is established by, for instance, injecting a non-wetting pad fluid, which then leaks off into the formation, followed by injection of the wetting proppant slurry. These two immiscible phases create the desired gradient.
Below in Tables 1-3, are three exemplary fracture treatment designs. In the first column, the name given to the stage is recited; in the second column is listed the fluid type; and in the third and fourth columns are the fluid volumes and proppant concentrations for that particular stage. The key to designing fracture treatments in accordance with the present Invention lies in creating the capillary pressure gradient. To do this, the pad (which leaks off, hence ultimately resides in the formation contiguous to the fracture) and the proppant slurry must be immiscible. In the case of a water-wet formation, ideal pad fluids are gelled oil, such as Schlumberger's YF GO III™. YF GO III is a gelled oil based fluid, originally designed for treatment of water-sensitive formations. To prepare YF GO III, a gelling agent and an activator solution made up of a pH control agent and crosslinker are added to the base fluid (e.g., oil diesel, kerosene, condensate, as well as a wide variety of crude oils). If YF GO III is used as the pad fluid, then the proppant slurry stages are comprised of, preferably guar or guar-based (e.g., HPG or CMHPG) fluids, whether cross-linked or not. Generally, treatment designs of the present Invention can comprise conventional additives (e.g., bactericides, breakers, clay stabilizers); however, additives such as surfactants should generally be avoided since they might compromise the immiscibility of the two phases. In general, this should be the test to assess whether any additive should be used in fracture treatments of the present Invention. Similarly, it may be undesirable to add fluid-loss control agents—e.g., fine-mesh sand, silica flour, etc.—that form a filter cake across the fracture-formation interface and also interfere with fluid transfer.
TABLE 1
Treatment Design #1
Proppant
concentration
Stage Name
Fluid Type
Volume (gal)
(lb/gal)
pad
diesel oil, gelled
50,000
0
proppant slurry 1
guar polymer-based
5,000
1
fluid
proppant slurry 2
guar polymer-based
7,000
2
fluid
proppant slurry 3
guar polymer-based
10,000
3
fluid
proppant slurry 4
guar polymer-based
12,000
4
fluid
proppant slurry 5
guar polymer-based
15,000
5
fluid
proppant slurry 6
guar polymer-based
13,000
6
fluid
flush
guar polymer-based
5,6000
0
fluid
TABLE 1
Treatment Design #1
Proppant
concentration
Stage Name
Fluid Type
Volume (gal)
(lb/gal)
pad
diesel oil, gelled
50,000
0
proppant slurry 1
guar polymer-based
5,000
1
fluid
proppant slurry 2
guar polymer-based
7,000
2
fluid
proppant slurry 3
guar polymer-based
10,000
3
fluid
proppant slurry 4
guar polymer-based
12,000
4
fluid
proppant slurry 5
guar polymer-based
15,000
5
fluid
proppant slurry 6
guar polymer-based
13,000
6
fluid
flush
guar polymer-based
5,6000
0
fluid
TABLE 3
Treatment Design #3
Proppant
concentration
Stage Name
Fluid Type
Volume (gal)
(lb/gal)
pad
diesel oil, gelled
30,000
0
pad
YF GO III
20,000
0
proppant slurry 1
cross-linked HPG
5,000
1
proppant slurry 2
cross-linked HPG
7,000
2
proppant slurry 3
cross-iinked HPG
10,000
3
proppant slurry 4
cross-linked HPG
12,000
4
proppant slurry 5
cross-linked HPG
15,000
5
proppant slurry 6
cross-linked HPG
13,000
6
flush
CMHPG
5,6000
0
The preceding discussion was intended to describe several preferred embodiments of the present Invention. The skilled artisan will no doubt realize that various modifications to the methods and compositions described above may be effected without departing from the basic concepts and principles of the present Invention. Thus, changes of this type are deemed to lie within the spirit and scope of the Invention; the present Invention is limited only by the claims that follow. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
CLAIMING BENEFIT UNDER 35 U.S.C. 120
[0001] This patent application is a continuation-in-part of U.S. patent application Ser. No. 11/249,938, docket number AUS920050613US1, filed on Oct. 13, 2005, by Yen-Fu Chen, et al.
FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT STATEMENT
[0002] This invention was not developed in conjunction with any Federally sponsored contract.
MICROFICHE APPENDIX
[0003] Not applicable.
INCORPORATION BY REFERENCE
[0004] The related U.S. patent application Ser. No. 11/249,938, docket number AUS920050613US 1 , filed on Oct. 13, 2005, by Yen-Fu Chen, et al., is hereby incorporated by reference in its entirety, including figures.
BACKGROUND OF THE INVENTION
[0005] 1. Field of the Invention
[0006] This patent application is a continuation-in-part of U.S. patent application Ser. No. 11/249,938, docket number AUS920050613US1, filed on Oct. 13, 2005, by Yen-Fu Chen, et al. This invention relates to the fields of data control, and especially to fields of determining and checking input data characteristics to databases.
[0007] 2. Background of the Invention
[0008] Various types of databases such as hierarchical, relational and object-oriented databases, offer consistent data storage, and provide transaction persistence, security, concurrency and performance. Consequently, a distributed architecture ( 30 ) that uses databases ( 34 - 35 ) as the back-end storage mechanisms and applications ( 33 ) for programming logic have become prevalent, as shown in FIG. 3 . Many of these database arrangements may be accessed over a network ( 32 ) by users of devices ( 31 ) such as web browsers, wherein users can retrieve and enter information to the databases via the application program.
[0009] Most databases have a maximum input string length requirement which is often specified in characters. Most database designs, however, actually implement their maximum string length in bits, bytes or words. In such a computing environment, a front-end application ( 33 ) normally checks the length in characters of user input strings prior to submitting the queries to the back-end database ( 34 , 35 ) so that it can prevent users from entering strings ( 36 ) that are longer than what database allows.
[0010] If the input strings are longer than database allowable length, an error message ( 37 ) is typically generated from database, will is often returned ( 37 ′) to the end user. However, this is an undesirable result because database error message may reveal table and column names, which is not only unprofessional in appearance to the user, it may violate one or more security guidelines. Moreover, the error message may not be user friendly.
[0011] In today's world, multi-language operating environments have increasingly become the norm of everyday business, and the application programs those enterprises use are required to handle multi-language input strings. It is not a troublesome issue in an purely English environment, such as a system using exclusively the American Standard Code for Information Interchange (“ASCII”), to check user input string length corresponding to database allowable fields since each character in ASCII encoding schema uses only one byte, and it isn't a big issue in other fixed byte-length native language encoding schema. In such a case, if a database specifies a maximum input string length of 128 characters in ASCII, one can assume that the database can handle input strings of length 128 bytes.
[0012] In another example, consider a database application which is operating in a Chinese-only environment which is utilizing GB5 encoding. GB5 stores every Chinese character in two bytes. To check input string length, the front-end application program can predict exactly how many characters are allowed corresponding to database fields by dividing allowable text entries in half (e.g. two bytes per character).
[0013] However, as different languages are used simultaneously within the same database, this can be much more problematic to address. For example, a common multi-language encoding schema is UTF-8. UTF-8 encoded strings can store characters using between one byte and three bytes per character, depending on the language from which the character or symbol is taken. For instance, a Chinese character in UTF-8 requires three bytes for encoding, while an Arabic character consumes only two bytes, a Hebrew character takes two bytes, a French character takes one or two bytes, an English character takes one byte, and special characters like currency symbols can take two bytes.
[0014] Many of today's front-end database applications are hard-coded to validate text entry length against database allowable length. Moreover, these applications are also often hard coded with logic to check whether text entry fields have at least one character to fulfill database requirement for not-nullable fields. Examples of validations done in code are shown in Table 1, using Sun Microsystem's Java™ code, and Table 2 using Java Script™.
TABLE 1 Example Java Code to Validate Database Input String Length if (ss.strPoNumber.length( ) < 1) { throw new AsErrorException(getMessage(“50001”)); }
[0015]
TABLE 2
Example Java Script to Validate Database Input String Length
// Use Maximum attribute in the text entry field in web pages.
//Maxlimit is a hard-coded value in the html page.
if(field.value.length > maxlimit) {
field.value = field.value.substring(0, maxlimit);
} else {
countfield.value = maxlimit − field.value.length;
}
[0016] The lengths function in the example of Table 1 checks whether the user's text entry has at least one character, and the maxlimit in the example of Table 2 requires a declaration of variable for allowable character length within the code scope. These are fundamentally flawed processes for checking input string length, especially in multi-lingual applications, for two reasons.
[0017] First, the maxlimit variable and the maximum attribute only counts the number of characters, not the number of bytes. In a multi-language environment, checking character length may produce wrong results because characters in UTF-8 can be one to three bytes in length, and the front-end applications cannot accurately predict whether a text string reaches the allowable database length.
[0018] For example, if there is a text entry field in a front-end application that uses a 10 byte database field, and a user enters a text string such as “I like IBM very much” in Chinese:
IBM
[0020] Today's applications would calculate the total number of characters of this entry as 9, but this string actually uses 18 bytes (5*3+3) when encoded in UTF-8. The application will consider the text entry is less than the maximum length in database, so it will submit the entry to the database, the database will detect the error, and will throw back an error message that the length is too long. At this point, the user will not be able to know how many characters to remove in order to fit into the database field.
[0021] Second, even if the front-end applications check the data length in bytes, it is tedious to change hard-coded variables when requirements or design desire changes in database field length or from null to not-null attribute. Such simple changes require considerable of code re-work on front-end applications, increasing the project risk and slowing down the development pace.
[0022] Therefore, a method and mechanism is needed in the art to calculate text string lengths in bytes for multi-lingual text encoding schemes. Further, there is a need in the art in some circumstances to centralize input string length checking logic for applications, in order to enable rapid changes in text entry length and enforce the not-null attribute. In other circumstances, there is a need in the art to distribute input string length checking in order to efficiently leverage distributed and locally cached database storage efficiencies.
SUMMARY OF THE INVENTION
[0023] The present invention provides system and method for preventing user-input text strings of illegal lengths from being submitted to a database where, for each character in the string, a character length is determined in quantities of digital units of storage according to an encoding schema, the character lengths are accumulated into a total string length, also measured in digital units of storage, and the total string length is compared to one or more database input field requirements such as non-null and maximum length specifications. If a limit is not met, the system and method are suitable disposed in a manner to block or prevent submission of the user-input string to the database. The invention can alternatively be realized as a plug-in for database front-end application programs, as a stand-alone web services provider, or as a plug-in for a client-side database access program such as a web browser.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The following detailed description when taken in conjunction with the figures presented herein provide a complete disclosure of the invention.
[0025] FIG. 1 shows a logical process according to one embodiment of the present invention.
[0026] FIGS. 2 a and 2 b show a generalized computing platform architecture, and a generalized organization of software and firmware of such a computing platform architecture.
[0027] FIG. 3 illustrates a typical arrangement of databases, front-end application(s), and a user's device for entering data into the databases.
[0028] FIGS. 4 a - 4 c provide example script code according to one embodiment of the present invention.
[0029] FIGS. 5 a - 5 c depict several embodiments of the present invention, including client-side, web services-based, and server-side implementations.
DESCRIPTION OF THE INVENTION
[0030] According to one embodiment of the present invention, a stand-alone Unicode Length Checker (“ULC”) plug-in ( 51 ) is provided to a front-end application to determine the number of bytes in a user's text entry ( 36 ), and to verify the string length and null attribute conformation in the memory, as shown ( 50 ) in FIG. 5 a . The text strings are preferably only submitted to database server after the length confirms with the allowable database field length.
[0031] In another embodiment of the present invention, the various functions of the ULC plug-in ( 51 ) are provided as Web services by a web server ( 53 ), which enables asset reuse for any applications ( 33 ), either using a database or content management system as a back-end system, as shown ( 52 ) in FIG. 5 b . In this embodiment, front-end application programs subscribing to the ULC plug-in's length-checking services can reside on anywhere on network ( 32 ), on any platform, and using any programming languages.
[0032] In yet another embodiment, the ULC plug-in ( 51 ) is provided as a stand-alone product, or Integrated Development Environment (“IDE”), database or content management middleware vendors can bundle the ULC plug-in and ship it with their products to ease the application development.
[0033] Some advantages realized by the present invention over the existing length-checking methods are:
(a) The length-checking logic is de-coupled from the hard-coded application as a stand-alone plug-in, which further facilitates the de-coupling of applications and physical database models. (b) Use of the ULC plug-in accelerates development of new applications, and minimizes the impact of database length changes to the application logic. Since the verification is performed against the live database or a metadata cache, a change to a database length does not require the programmers modify the hard-coded value or configuration file. Thus, it reduces unnecessary effort to keep presentation layer and database layer in synch and relieve programmers from tedious work on coding and maintaining the length check logic. (c) The invention enables asset reuse based on length-checking patterns. The ULC plug-in can be used with any application regardless of its location, platform or programming language. Asset reuse rate increases greatly when these functions are offered as Web services via Service-Oriented Architecture (“SOA”). (d) The ULC plug-in can work with any national language strings that use any encoding schemas (e.g. for fixed-byte or variable-byte encoding schemas). It is particularly useful when used with UTF-8 or other variable-byte encoding schemas. (e) The ULC plug-in eases change management. A change in database doesn't require change in the application; a change in text entry length does not always require a database change.
[0039] FIGS. 4 a - 4 c disclose one embodiment of the invention in the form of an “industrial strength” JavaScript program, including explanatory comments within the example code. In order to employ this script, a web page designer may simply add the script code into the <head>section of the Hyper Text Markup Language (“HTML”) page. For example, actual HTML to invoke the invention for an <input>tag is shown in Table 3.
TABLE 3 Example HTML Code to Invoke the ULC Plug-in <input type=“text” name=“text1” ............ onFocus=“focusit( )” onblur=“blurit(this)” /> <input type=“hidden” name=“utf8sizetext1” value=“50” />
[0040] In this example, the use of the “hidden” tag is to pass the value of 50, in this case, which gives the maximum number of bytes. These two lines of code can either be written or done automatically by custom struts or Java Server Faces, both of which are programming methodologies which are well known in the art. Preferably, the input values are read from the database using initialization (“init”) processing, and then stored in a static hashtable. In this example, it would be also possible to retrieve that information in the custom Struts or JSF tag.
[0041] Particularly in FIG. 4 c , the UTF-8 Unicode string length is counted ( 42 ) by using the JavaScript charCodeAt() method, which returns a number indicating the Unicode value of the character at the given index. If a character's Unicode value is equal to zero, the total length variable is incremented by 2 to represent 2 bytes of additional length ( 44 ). Likewise, if a character's Unicode value is less than 128, only 1 byte of length is added to the total length variable ( 45 ). If the character's Unicode value is less than 4096, then two bytes are added to the byte length total ( 46 ). Otherwise, three bytes are added to the byte length total ( 47 ). This is repeated ( 43 ) until all characters in the string have been considered, such that the total length in bytes is accumulated and reported to the calling application program. Preferably, a check is also made to make sure that the string is a non-null or non-empty entry, an error is returned if so.
[0042] In this manner, the invention considers each character using native functions of the programming language in which the invention is embodied to determine the codepoint of each character. Then, according to the encoding schema of the string such as UTF-8, ASCII, GB5, etc., the number of bytes associated with that codepoint are added to an accumulated total string length, until all characters have been considered, and a total string length in binary units (e.g. bits, bytes, words, etc.), has been determined. For certain encoding schemes, such as UTF-8, the storage lengths of codepoints may be associated with ranges or segments of codepoint values, which greatly simplifies processing because it can be done not on a specific character lookup basis, but rather on a ranged basis.
[0043] For embodiments of the invention intended to assist in offline database input processing, one available implementation option is to serialize and send the static hashtable as part of the offline application.
[0044] The following, more detailed description of the invention is provided using several particular example implementations. It will be recognized by those skilled in the art that the features, descriptions, high level implementation provided in the following paragraphs can be implemented in a variety of programming languages using a variety of programming methodologies.
[0000] Invocation Using Style Sheet
[0045] In this implementation, the invention is provided as a client side style sheet in extensible Markup Language (“XML”). In this form, the invention is independent from any particular front-end application programs, and it also has accessibility and validity advantages.
[0046] Turning to FIG. 1 , a style sheet is initially written ( 12 ), then programmers can use it without further modification. The field length metadata can be obtained ( 13 , 19 ) by either directly querying live databases ( 100 ), or querying against a cached catalog ( 101 , 102 ). After the data from cache is optionally loaded ( 14 ), and the user click's on “submit”, “save”, “send”, or similar action triggers ( 15 ), the ULC plug-in optionally ( 16 ) checks ( 103 ) the length of each input according to the process of the invention.
[0047] If the length is found to be acceptable to the targeted database ( 104 ), it is passed on for normal handling and input to the database ( 17 ). Otherwise, a custom error message may be provided ( 105 ) to the user, as opposed to the cryptic error messages provided by databases upon such an error. The process ( 10 ) may be repeated ( 18 , 11 ) as needed for additional input strings.
[0048] In this manner, the input strings which do not conform to the database input limits are blocked from being submitted to the database, cryptic error messages and security leaks are avoided, and intelligible, user-friendly error messages are provided in their stead.
[0000] Strut-based Embodiment
[0049] In this implementation, a Strut is employed to automate the process of putting the hidden fields in web pages. From a programming perspective, this can be done automatically. In operation, the front-end application program passes the sizes of database fields to hidden fields in the web pages, then as users are entering the characters in the web pages, the front-end application program calculates the number of bytes for UTF-8 strings until the strings reach the maximum allowable fields for the database.
[0000] Client-side Cached Catalog Embodiment
[0050] In this implementation of the invention ( 51 ), a database catalog ( 54 ) is stored as a cache on the client side ( 31 ), which is used to perform length checking at the client, such that only checked or qualified input strings ( 36 ′) are sent to the front-end application programs ( 33 ), as shown in FIG. 5 c . This embodiment works very well with off-line application programs, and has performance advantages over real-time, networked database catalog access, as there is a growing need to use off-line applications to store data on the client, and synchronize to the database server later on. According to this aspect of the invention, the ULC plug-in length checking logic does not depend on connectivity to a remote database via a network.
[0051] The database catalog cache is preferably encrypted to provide security in circumstances where is it not desired for users be aware of or have access to database tables and column field names. In this arrangement, mapping of real database field names and alias of the cache is performed by the application program running on the server, not on the client computer, such that users only know the maximum length and the parameter names for input fields.
[0052] The database catalog cache is preferably either stored as XML or in IBM's Cloudscape™, a well-known type of embedded database. In the latter case, few users would be aware of an embedded database existing on the client side, but it offers many features which came with matured relational database technology, such as storage persistence and SQL access.
[0000] Error Response, Tracking, and Resolution
[0053] When a user-entered text string exceeds the maximum allowed field length for a database, the ULC plug-in preferably logs the event so that application administrators or designers can direct feedback and audit history to know how many users have similar problems. This information can guide the administrators or designers to make an informed decision whether to increase database length.
[0054] There are several options to implementing logging of field length options, including but not limited to the following:
(a) As soon as a user exceeds the text string, the application issues a pop-up message to warn the user and stops further typing in the field. The benefit is that the user will not waste his/her effort on typing something that will not be accepted. (b) The invention allows the user to continue typing the text after reaching the allowable length, but the application issues a warning and indicates where it exceeds the limit only AFTER the user submits the page. In this embodiment, the application only stores the string within the length limit, preferably. The benefit here is that the inventor or application can log how much the strings are exceeded, and can provide accurate feedback to the administrators. (c) The database fields are created with very long length, but the application determines the maximum text entry according to its own rules upon submission of an entry. To avoid high amount of input and output when databases need to fetch these long rows, it is preferably to design these long fields in variable length since they only use bytes that are needed. The benefit of this approach is that one can change text entry field length in the application without having to change the database structure every time. (d) The application stores the extra characters in the overflow fields based on certain criteria that are defined by the administrators, such as users' roles, organizations and service level agreements. This approach fits nicely with on-demand services. Besides being applicable to data entry fields, this embodiment can be applicable to content management systems, providing adjustable differential, maximum length and overflow attributes. For example, in a weblog (“blog”) related application, benefit is taken from the customizable length as it is simply not practical to allow every blog entry to exceed an unlimited length, e.g. over 32 KB. Using the present invention, the system administrators can allow certain important topics or certain groups to extend 32 KB.
Overflow Character Processing
[0059] With particular focus on the embodiment described in the previous paragraph, the invention preferably captures overflow characters (e.g. characters which extend beyond the allowed input string length), records those characters, and then provides for configurable processing of those captured overflow “sub-strings”. These logs of overflow information can be stored in a typical operational database, data mart, or data warehouse ( 110 ), so that other users or application programs can access them and perform analysis of them as desired.
[0060] For example, if a particular database field called “customer_comment” in an online hotel reservation system is limited to 75 characters, the following input string from a user:
[0061] “Requesting non-smoking, poolside room, please”
[0062] would be acceptable having a length of 45 characters, and would be submitted to the remote database without blocking.
[0063] However, the user-input string for “customer_comment” of:
“Please make sure my room is not above the second floor, as I have a fear of hotel fires and not being able to escape.”
[0000] would exceed the allowed 25 character length by 42 characters, wherein the overflow sub-string captured by the invention would be:
“f hotel fires and not being able to escape.”
[0064] According to one aspect of this embodiment of the invention, each individually captured overflow sub-string is processed by the invention, such as storing the sub-string in a second field called “comment_overflow — 1”. In this manner, an on-demand computing system can dynamically allocate memory or storage space if an overflow occurs.
[0065] According to another aspect of this embodiment of the invention, processing or analysis of many captured overflow sub-strings is performed to yield statistical and other information useful for management of the system, upgrading of the system, and especially on-demand allocation of the resources. For example, after a system such as the previously described hotel reservation system is run for a period of time, such as once per day or once per month, the character lengths of the captured overflow sub-strings can be analyzed to determine the average overflow length, which can then be used to determine a system upgrade plan, such as an on-demand resource allocation increase. If, for example, 15,000 reservations are used, the processing may determine that 95% of the reservations did not use or exceed the “customer_comment” field length, and that the 5% of reservations that did use exceed this field length, 80% of them exceeded the field length by 40 characters or less. So, a system administrator, or an on-demand resource allocation function, could allocate additional database storage to accommodate a maximum field length of 105 characters in order to handle 99% of reservations (e.g. 95%+(5% ·80%)).
[0066] Both aspects, individual and group overflow analysis, can be performed within the same embodiment, of course, if needed, as well as other types of analysis can be performed beyond the examples provided herein.
[0067] According to another aspect of the present invention, the schema applied to capturing and processing overflow string input information is based upon the user's role in an organization (e.g. manager, editor, administrator, etc.), a user's service level agreement (e.g. a contract between a computing services supplier and a computing services consumer which may stipulate resource consumption limits, costs, etc.), and the like. For example, if the overflow handling schema is based upon the user's role, the foregoing example overflow information may be stored in the additional “comment_overflow — 1” field only if the inputting user is a manager or system administrator. In another example, the overflow information may be stored in the overflow field only if the service level agreement for the user's organization permits charging of the organization for the additional storage space.
[0000] Suitable Computing Platform
[0068] The invention is preferably realized as a feature or addition to the software already found present on well-known computing platforms such as personal computers, web servers, and web browsers. These common computing platforms can include personal computers as well as portable computing platforms, such as personal digital assistants (“PDA”), web-enabled wireless telephones, and other types of personal information management (“PIM”) devices.
[0069] Therefore, it is useful to review a generalized architecture of a computing platform which may span the range of implementation, from a high-end web or enterprise server platform, to a personal computer, to a portable PDA or web-enabled wireless phone.
[0070] Turning to FIG. 2 a , a generalized architecture is presented including a central processing unit ( 21 ) (“CPU”), which is typically comprised of a microprocessor ( 22 ) associated with random access memory (“RAM”) ( 24 ) and read-only memory (“ROM”) ( 25 ). Often, the CPU ( 21 ) is also provided with cache memory ( 23 ) and programmable FlashROM ( 26 ). The interface ( 27 ) between the microprocessor ( 22 ) and the various types of CPU memory is often referred to as a “local bus”, but also may be a more generic or industry standard bus.
[0071] Many computing platforms are also provided with one or more storage drives ( 29 ), such as a hard-disk drives (“HDD”), floppy disk drives, compact disc drives (CD, CD-R, CD-RW, DVD, DVD-R, etc.), and proprietary disk and tape drives (e.g., Iomega Zip [™] and Jaz [™], Addonics SuperDisk [™], etc.). Additionally, some storage drives may be accessible over a computer network.
[0072] Many computing platforms are provided with one or more communication interfaces ( 210 ), according to the function intended of the computing platform. For example, a personal computer is often provided with a high speed serial port (RS-232, RS-422, etc.), an enhanced parallel port (“EPP”), and one or more universal serial bus (“USB”) ports. The computing platform may also be provided with a local area network (“LAN”) interface, such as an Ethernet card, and other high-speed interfaces such as the High Performance Serial Bus IEEE-1394.
[0073] Computing platforms such as wireless telephones and wireless networked PDA's may also be provided with a radio frequency (“RF”) interface with antenna, as well. In some cases, the computing platform may be provided with an infrared data arrangement (“IrDA”) interface, too.
[0074] Computing platforms are often equipped with one or more internal expansion slots ( 211 ), such as Industry Standard Architecture (“ISA”), Enhanced Industry Standard Architecture (“EISA”), Peripheral Component Interconnect (“PCI”), or proprietary interface slots for the addition of other hardware, such as sound cards, memory boards, and graphics accelerators.
[0075] Additionally, many units, such as laptop computers and PDA's, are provided with one or more external expansion slots ( 212 ) allowing the user the ability to easily install and remove hardware expansion devices, such as PCMCIA cards, SmartMedia cards, and various proprietary modules such as removable hard drives, CD drives, and floppy drives.
[0076] Often, the storage drives ( 29 ), communication interfaces ( 210 ), internal expansion slots ( 211 ) and external expansion slots ( 212 ) are interconnected with the CPU ( 21 ) via a standard or industry open bus architecture ( 28 ), such as ISA, EISA, or PCI. In many cases, the bus ( 28 ) may be of a proprietary design.
[0077] A computing platform is usually provided with one or more user input devices, such as a keyboard or a keypad ( 216 ), and mouse or pointer device ( 217 ), and/or a touch-screen display ( 218 ). In the case of a personal computer, a full size keyboard is often provided along with a mouse or pointer device, such as a track ball or TrackPoint™. In the case of a web-enabled wireless telephone, a simple keypad may be provided with one or more function-specific keys. In the case of a PDA, a touch-screen ( 218 ) is usually provided, often with handwriting recognition capabilities.
[0078] Additionally, a microphone ( 219 ), such as the microphone of a web-enabled wireless telephone or the microphone of a personal computer, is supplied with the computing platform. This microphone may be used for simply reporting audio and voice signals, and it may also be used for entering user choices, such as voice navigation of web sites or auto-dialing telephone numbers, using voice recognition capabilities.
[0079] Many computing platforms are also equipped with a camera device ( 2100 ), such as a still digital camera or full motion video digital camera.
[0080] One or more user output devices, such as a display ( 213 ), are also provided with most computing platforms. The display ( 213 ) may take many forms, including a Cathode Ray Tube (“CRT”), a Thin Flat Transistor (“TFT”) array, or a simple set of light emitting diodes (“LED”) or liquid crystal display (“LCD”) indicators.
[0081] One or more speakers ( 214 ) and/or annunciators ( 215 ) are often associated with computing platforms, too. The speakers ( 214 ) may be used to reproduce audio and music, such as the speaker of a wireless telephone or the speakers of a personal computer. Annunciators ( 215 ) may take the form of simple beep emitters or buzzers, commonly found on certain devices such as PDAs and PIMs.
[0082] These user input and output devices may be directly interconnected ( 28 ′, 28 ″) to the CPU ( 21 ) via a proprietary bus structure and/or interfaces, or they may be interconnected through one or more industry open buses such as ISA, EISA, PCI, etc.
[0083] The computing platform is also provided with one or more software and firmware ( 2101 ) programs to implement the desired functionality of the computing platforms.
[0084] Turning to now FIG. 2 b , more detail is given of a generalized organization of software and firmware ( 2101 ) on this range of computing platforms. One or more operating system (“OS”) native application programs ( 223 ) may be provided on the computing platform, such as word processors, spreadsheets, contact management utilities, address book, calendar, email client, presentation, financial and bookkeeping programs.
[0085] Additionally, one or more “portable” or device-independent programs ( 224 ) may be provided, which must be interpreted by an OS-native platform-specific interpreter ( 225 ), such as Java™ scripts and programs.
[0086] Often, computing platforms are also provided with a form of web browser or micro-browser ( 226 ), which may also include one or more extensions to the browser such as browser plug-ins ( 227 ).
[0087] The computing device is often provided with an operating system ( 220 ), such as Microsoft Windows™, UNIX, IBM OS/2™, IBM AIX™, open source LINUX, Apple's MAC OS™, or other platform specific operating systems. Smaller devices such as PDA's and wireless telephones may be equipped with other forms of operating systems such as real-time operating systems (“RTOS”) or Palm Computing's PalmOS ™.
[0088] A set of basic input and output functions (“BIOS”) and hardware device drivers ( 221 ) are often provided to allow the operating system ( 220 ) and programs to interface to and control the specific hardware functions provided with the computing platform.
[0089] Additionally, one or more embedded firmware programs ( 222 ) are commonly provided with many computing platforms, which are executed by onboard or “embedded” microprocessors as part of the peripheral device, such as a micro controller or a hard drive, a communication processor, network interface card, or sound or graphics card.
[0090] As such, FIGS. 2 a and 2 b describe in a general sense the various hardware components, software and firmware programs of a wide variety of computing platforms, including but not limited to personal computers, PDAs, PIMs, web-enabled telephones, and other appliances such as WebTV™ units. As such, we now turn our attention to disclosure of the present invention relative to the processes and methods preferably implemented as software and firmware on such a computing platform. It will be readily recognized by those skilled in the art that the following methods and processes may be alternatively realized as hardware functions, in part or in whole, without departing from the spirit and scope of the invention.
CONCLUSION
[0091] The present invention has been described, including several illustrative examples. It will be recognized by those skilled in the art that these examples do not represent the full scope of the invention, and that certain alternate embodiment choices can be made, including but not limited to use of alternate programming languages or methodologies, use of alternate computing platforms, and employ of alternate communications protocols and networks. Therefore, the scope of the invention should be determined by the following claims. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention pertains to article holders, particularly paper and paper sign holders, electrostatically supported upon glass or similar dielectric material by electrostatic force, the holder including a pair of relatively displaceable magnets between which the paper is held by magnetic force.
2. Description of the Related Art
Signs and banners, such as paper signs, are usually mounted within store windows by tape. The use of tape to support window signs is unsightly, the tape is often very difficult to remove from the glass, and there is a need for holders for paper signs and the like which does not require tape.
Electrostatic forces have been used in conjunction with display devices, such as shown in U.S. Pat. No. 4,741,119. Also, it is also known to use magnetic forces with articles and signs wherein magnets are employed to directly or indirectly support the sign, such as shown in U.S. Pat. Nos. 2,815,595; 4,222,489; 4,255,837; 4,475,300 and 4,703,575. However, the devices shown in these patents are expensive, somewhat difficult to use, and have not found ready commercial acceptance.
An inexpensive sign holder which is attached to a glass window or other supporting surface by a pressure sensitive adhesive is shown in U.S. Pat. No. 4,258,493. However, sign holders using adhesives have the disadvantage of being permanently affixed at a predetermined location on the window making the holder only suitable with particular sizes of signs, and where an adhesive is used to attach the holder to the glass unsightly deposits on the glass may remain after the sign holder is removed, and once the holder is used it cannot be easily reused.
SUMMARY OF THE INVENTION
Objects of the Invention
It is an object of the invention to provide an article holder particularly suitable for holding paper signs in windows using electrostatic forces and magnetic forces wherein an economical sign holder may be fabricated of low cost materials.
An additional object of the invention is to provide a sign holder using electrostatic and magnetic forces wherein the sign holder may be readily located upon its supporting surface, such as a glass window, may be readily relocated and reused, and wherein no residue or marks are deposited upon the supporting surface due to the attachment of the sign holder.
Yet another object of the invention is to provide a sign holder utilizing electrostatic and magnetic forces wherein the sign holder is attractive, may be used by persons of ordinary skill, requires no tape or similar ancillary components, and is attractive and dependable in operation.
In the practice of the invention, the sign holder basic member comprises a base of flexible electrostatic sensitive and attractable material, such as static cling vinyl, which is of a flexible film construction and will readily adhere to dielectric surfaces such as window glass. Preferably, the base is of a rectangular configuration having a central region located between upper and lower edges.
The article holding clip section of the holder consists of a body or section of flexible material, preferably static cling vinyl, which is attached to the base central region either by electrostatic force, heat sealing or an adhesive. The clip section includes a backing portion attached to the base, and a flap portion hinged to the backing portion by the flexible nature of the clip material. Elongated magnets are affixed to the inner faces of the backing and flap portions in opposed relationship whereby the article to be clamped, such as a sheet of paper or sign, may be located between the magnets and gripped thereby by the magnetic attraction between the magnets. The magnets are adhesively bonded to the inner faces of the backing and flap portion.
By utilizing a base of relatively large area, the base may be firmly electrostatically attached to a window or other dielectric smooth surface. In this manner, the magnet clip will be supported so as to hold a paper or sign. The base may be easily removed from the window, or relocated thereon, without leaving a residue on the window, and as the clip flap portion may be readily lifted to separate the magnets, paper may be easily inserted between the magnets, or released from their gripping force.
An electrostatic article holder in accord with the invention may be economically manufactured, can be formed of attractive colors, or be substantially transparent, and provides an article holder achieving the aforedescribed objects of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The aforementioned objects and advantages of the invention will be appreciated from the following description and accompanying drawing wherein:
FIG. 1 is a perspective exploded view of an electrostatic and magnetic holder in accord with the inventive concepts,
FIG. 2 is a front elevational view of the holder,
FIG. 3 is an end elevational view of the holder with the magnets in the paper holding relationship,
FIG. 4 is an end elevational view illustrating the clip flap portion in an open position for receiving or releasing paper,
FIG. 5 is a reduced scale perspective illustration of the manner in which the holder of the invention may be employed in conjunction with a store window, and
FIG. 6 is a elevational view illustrating the holder being installed in an inverted position for use with a banner loop or the like.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An electrostatic and magnetic holder in accord with the invention is generally represented at 10 in the drawings, and includes a rectangular base 12. The base 12 is formed of a flexible electrostatically chargeable material such as static cling vinyl and includes ends 14 and parallel lateral sides 16. A central region 18 is defined between the sides 16, and the base 12 includes an outer face 20 and an inner face 22.
Preferably, a protective shield 24 is adhered to the base inner face 22 to keep the face 22 clean and free of foreign matter during shipping and handling. The protective shield 24 may be formed of thick paper or the like having a wax or plastic surface whereby the electrostatic forces between the shield 24 and base face 22 will maintain the shield 24 firmly against the face 22, and yet, the shield 24 may be readily peeled from the base surface. The protective shield 24 is removed from the base face 22 prior to the article holder 10 being used.
A clip designated 26 is attached to the base central region 18 to the outer face 20. The clip 26 consists of a section of a flexible electrostatic attractable material such as static cling vinyl and includes a backing portion 28 and a flap portion 30, these portions being interconnected by a flexible hinge portion 32 wherein the flap portion 30 may be "pivotably" positioned relative to the back portion 28 between open and closed positions as shown in FIGS. 3 and 4.
The backing portion 28 includes an outer face 34 and an inner face 36, while the flap portion 30 includes an inner face 38. An elongated rectangular magnet 40 is bonded to the back portion inner face 36, while a similarly sized magnet 42 is bonded to the flap portion inner face 38. The magnets are attached to their respective support surfaces by an adhesive 44 interposed between the magnets and the associated clip portions' inner faces.
As will be appreciated from the drawing, the backing portion lower edge 46 extends below the flap portion lower edge 48, and in this manner the portion of the flap portion between the magnet 42 and the edge 48 constitutes a deflectable handle which may be readily grasped by the user to raise the flap portion 30 to the open position shown in FIG. 4 wherein the magnets 40 and 42 are separated.
Because both the base 12 and the clip 26 are formed of a static cling vinyl the clip 26 may be attached to the base central region 18 solely by the electrostatic forces that exist between the base face 20 and the clip backing portion outer face 34. Such electrostatic forces between the base 12 and clip 26 are sufficient to achieve the desired assembly between these components.
However, in the preferred commercial embodiment an adhesive 50 is placed between the base outer face 20 and the clip backing portion outer face 34 to assure a firm mechanical assembly of the base 12 and clip 26. When the adhesive 50, or heat sealing, is used to interconnect the base 12 and clip 26, it is not necessary that the clip be formed of a static cling material, and could be formed of any flexible material which would permit the material to hinge at 32 and permit the magnets 42 and 44 to be engaged and separated.
To use the article holder 10, if the protective shield 24 has not been removed from the base inner face 22, the protective shield should be peeled therefrom to expose the base inner face 22 so that the face 22 may be firmly pressed against a supporting surface, such as glass window 56, FIG. 5, and the base may be "ironed" against the glass by the user's fingers to eliminate air bubbles and the like.
The electrostatic nature of the base 12 will cause the base 12 to be firmly attached to the glass 56 without the use of an adhesive, and yet it is possible to peel the base 12 from the glass 56 when it is desired to remove the article holder 10, or relocate the article holder upon the glass window.
Once the article holder 10 is attached to the glass supporting surface 56 the user grasps the flap portion 30 adjacent the lower edge 48 and raises the flap portion 30 as shown in FIG. 4 to separate the magnets 40 and 42. Thereupon a paper sign or the like, represented at 58, may be inserted between the magnets, and release of the flap portion 30 will permit the magnets 40 and 42 to be attracted toward each other firmly gripping the sign 58 as shown in FIG. 3. Of course, for the magnets to be attracted to each other, opposed magnet faces have opposite polarity.
To remove the sign 58 from between the magnets 40 and 42, it is only necessary to grasp the clip flap portion 30 adjacent the lower edge 48 and lift the flap portion as shown in FIG. 4.
The magnets 40 and 42 may be formed of a barium ferrite powder utilizing binder materials is as known. The adhesives 44 and 50 may constitute double sided acrylic tape, but other types of compatible adhesives may be used. Also, it is possible to heat seal the base 12 and the clip backing portion 28 together. The thickness of the material used to form the base 12 and the clip 26 usually range between seven and twelve mils.
It is impossible to use the article holder 10 of the invention to support a loop, such as may be formed on a banner or other article which cannot be readily grasped and held by the magnets 40 and 42. Such use of the article holder 10 is represented in FIG. 6. In such instance, the article holder orientation is reversed from its usual orientation such that the clip 26 "opens" upwardly. Because a space exists between the nearest sides of the magnets 40 and 42 and the hinge portion 32 a hinge loop cavity 52, FIG. 3, exists adjacent the hinge, and this lop may be used to receive the cord 54 of a banner or other article wherein the same may be suspended from the article holder 10. In such instance, the magnets 40 and 42 will be engaging each other, and the article holder 10 is capable of supporting considerable weight in this manner.
It will be appreciated that when supporting a sign, banner, or the like, the forces imposed upon the article holder 10 will be substantially parallel to the plane of the supporting surface, i.e. glass 56. Thus, primarily shear forces are interposed between the base 12 and the glass 56, and the electrostatic forces maintaining these components in engagement is sufficient to permit relatively high shear forces to be resisted without pulling the article holder from the surface of the glass 56. However, when removing the article holder 10 from the glass 56 by peeling a corner of the base 12 from the glass and pulling the base directly away from the glass the base 12 may be easily separated from the glass supporting surface.
All of the components of the article holder 10 are economically manufactured, and as the assembly techniques may be economically achieved an article holder 10 in accord with the inventive concepts is of a low cost. The material of the base 12 and clip 26 may be transparent as to permit the article holder to be unobtrusive, but if desired, the vinyl material may be brightly colored for aesthetic purposes.
It is appreciated that various modifications to the inventive concepts may be apparent to those skilled in the art without departing from the spirit and scope of the invention. | 4y
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BACKGROUND
1. Technical Field
This invention relates to inflation needles, and more particularly to needles for inflating sports balls and the like.
2. Background Information
Throughout this application, various publications, patents and published patent applications are referred to by an identifying citation. The disclosures of the publications, patents and published patent applications referenced in this application are hereby incorporated by reference into the present disclosure.
Traditional inflation needles for sports balls and like include relatively long, thin hollow metallic probes configured to be axially inserted into the bung of the ball. While these needles may be reasonably effective in many applications, they have been found to be relatively delicate and subject to bending and breakage during use. Such breakage is at best inconvenient, requiring a user to remove the broken pieces from a pump and/or ball, and to begin the inflation process again with a new inflation needle. Such breakage also runs the risk, however, of the severed probe tip becoming lodged within the bung, where it may become difficult if not impossible to remove without damaging the ball.
Examples of various inflation needles include that disclosed by Gaines in U.S. Pat. No. 6,923,222, which is a conventional inflating needle of the type commonly employed for inflating sports balls.
Morris et al. (U.S. Pat. No. 4,043,356) disclose an inflator probe for filling gas containers, which includes a one-piece body molded from a plastic material and providing a cylindrical externally threaded end piece for attachment to a pump followed by an enlarged-diameter shoulder having finger grips and an elongated tapered nozzle extending therefrom.
Blair (U.S. Pat. No. 615,670) discloses a multiple component inflating nipple which includes a tapered shank threadably engaged with a nut captured at an end of a cup. The relatively narrow cup axially supports the shank as the nut is rotated to effect insertion.
None of these references disclose or address the problem of needle breakage during use. A need, therefore, exists for an improved inflation needle which addresses drawbacks of the prior art.
SUMMARY
In one aspect of the invention, an inflation needle, includes a tubular body having an attachment end configured for engagement with an air pump. The body fairs into a tubular probe extending along a longitudinal axis from a proximal end to a distal end which is configured for being inserted into an object to be inflated. A concavo-convex base extends radially outward from the body and towards the distal end, and terminates at a periphery spaced radially from the tubular probe, and which is configured to engage the object upon insertion of the probe therein. The periphery defines a transverse dimension of the base, and the probe defines an axial dimension extending from the periphery to the distal end, and a ratio of the transverse dimension to the axial dimension is at least 0.5:1. The inflation needle is a unitary, molded polymeric component.
In another aspect of the invention, an inflation needle includes a tubular body having an attachment end configured to be engaged with a fluid supply. The body fairs into a tubular probe extending along a longitudinal axis from a proximal end to a distal end configured for being inserted into an object to be inflated. A concavo-convex base extends radially outward from the body and towards the distal end, terminating at a periphery spaced radially from the tubular probe, the base being configured to engage the object upon insertion of the probe therein. The inflation needle is a unitary, molded polymeric component.
In still another aspect of the invention, a method for manufacturing an inflation needle includes providing a tubular body having an attachment end configured to be engaged with a fluid supply, and fairing the body into a tubular probe extending along a longitudinal axis from a proximal end to a distal end configured for being inserted into an object to be inflated. A base is extended radially outward from the body and towards the distal end, terminating at a periphery spaced radially from the tubular probe, so that the base has a substantially concave surface facing the distal end, the base being configured to engage the object upon insertion of the probe therein. The inflation needle is molded as a unitary, polymeric component.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other features and advantages of this invention will be more readily apparent from a reading of the following detailed description of various aspects of the invention taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of an embodiment of the subject invention;
FIG. 2 is a perspective view of an alternate embodiment of the subject invention;
FIG. 3 is a perspective view of another alternate embodiment of the subject invention; and
FIG. 4 is an elevational view of still another embodiment of the subject invention shown in engagement with a portion of an object to be inflated.
DETAILED DESCRIPTION
In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized. It is also to be understood that structural, procedural and system changes may be made without departing from the spirit and scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined by the appended claims and their equivalents. For clarity of exposition, like features shown in the accompanying drawings shall be indicated with like reference numerals and similar features as shown in alternate embodiments in the drawings shall be indicated with similar reference numerals.
Where used in this disclosure, the term “axial” when used in connection with an element described herein, refers to a direction substantially parallel to the insertion direction of the needle. The term “transverse” refers to a direction other than (e.g., substantially orthogonal) to the axial direction. The term “fluid” is used in its conventional sense, to refer to gases such as air, and liquids.
It was discovered by the instant inventors that prior art inflation needles tended to break due to the relatively high transverse (shear) forces to which the needles were often subjected during use. It was found that it is often difficult to insert the probe and inflate the ball without accidentally pushing the probe sideways, i.e., transversely to the insertion direction. Conditions of the sports field and use by children tend to be particularly conducive to rough handling of the needle. Also, the rounded surfaces of various sports balls make them particularly likely to roll as pressure is applied to the needle to insert and/or maintain secure engagement with a pump, which may serve to apply a transverse, bending moment to the needle. This bending moment, due to the needle's relatively small transverse dimension and thin tubular walls, has been found to often result in fractures or breaks therein. It was hypothesized that by providing a means to oppose these transverse forces, the needle would be better able to resist such breakage.
Embodiments of the present invention include an inflation needle having a probe and a flange or base which would engage the curved surface of a ball, etc., upon insertion of the probe. In the event the probe is pushed in a sideways direction during insertion or inflation, this movement would be opposed by engagement of the flange with the ball. In addition, the compression force associated with continued pressure applied to the needle, such as to maintain connection with the pump during inflation, may be distributed over the wider cross sectional area of the flange, rather than being concentrated on the narrower probe. In particular embodiments, the base is substantially concavo-convex, with a generally concave surface facing the ball, to enable its periphery to engage the rounded surface of the ball. In particular embodiments, the concavo-convex base is cylindrical or frusto-conical.
Referring now the Figures, embodiments of the invention will be described in greater detail. Turning to FIG. 1 , an inflation needle 100 has a concavo-convex base 104 which, upon full insertion of the probe 108 , engages the surface of the object to be inflated, such as the spherical surface of a sports ball. The skilled artisan, upon review of the instant disclosure, will recognize that the substantially concave inner configuration of base 104 enables it to engage a substantially convex surface (e.g., of a ball), at a point spaced transversely from probe 108 . Indeed, as best shown in FIG. 4 , the concavo-convex structure of the various base configurations enables them to engage the convex surface 150 of a ball, along their peripheries 114 . This relatively widely spaced engagement provides a relatively large moment arm to counteract any bending moment inadvertently applied by the user as discussed above.
An attachment end 102 is configured to be coupled to a pump or other supply of air (e.g., compressor or other compressed gas supply) or other fluid suitable to the particular application. In the embodiment shown, the attachment end 102 is threaded or knurled to facilitate attachment to a fluid supply. Those skilled in the art will recognize that attachment end 102 may be provided with nominally any other type of fitting to facilitate fluid connection.
The base 104 may include a scored edge 106 , allowing an improved grip for a user grasping the base 104 during handling, such as while coupling the attachment end 102 to the fluid supply and/or inserting the needle into the ball. The needle 100 is tubular/hollow and includes at least one hole 110 near the distal (insertion) end, to allow the fluid to flow therethrough in a conventional manner. In alternate embodiments, the insertion end of the probe 108 may comprise two or more holes 110 .
In particular embodiments, the needle 100 is fabricated from a moldable polymeric material, such as a high density or reinforced plastic. Selection of particular polymeric materials may enable the probe 108 thereof to be more resilient and less susceptible to breakage than a traditional metallic needle. Examples of suitable materials include but are not limited to polyamide (NYLON® DuPont), thermoplastics, or engineered resins, such as sulfone polymers, polypropylene, polyethylene, polyesters, polycarbonate, polyurethane, acrylonitrile-butediene-styrene (ABS), styrene-acrylonitile (SAN), or fiberglass. Fabrication of the needle from these polymers, particularly when using conventional high-volume approaches such as injection molding, may reduce manufacturing costs and/or complexities relative to traditional multiple-component metallic needles.
In an alternate embodiment, the inflation needle may include a stem, such as to provide improved grip for a user. Referring to FIG. 2 , needle 200 includes a stem 212 disposed between base 104 and attachment end 102 . A stem may be used with bases of nominally any desired shape, such as the frusto-conical base 304 of FIG. 3 . As shown, stem 212 optionally has grooved, striated sides to allow better gripping during use. As also shown, in particular embodiments, the exterior transverse dimension of stem 212 is approximately equal to the exterior dimension of attachment end 102 , as will be discussed in greater detail hereinbelow with respect to FIG. 4 .
As shown in FIG. 3 , needle 300 includes a concavo-convex base 304 which is substantially frusto-conical. Base 304 is also shown with an optional scored edge 306 for improved grip by the user.
Turning now to FIG. 4 , embodiments of the present invention may be provided with a wide range of dimensions suitable for any of various inflation applications. For many applications, base 104 , 304 , 404 is provided with an exterior transverse dimension T, and probe 108 is provided with an axial dimension A 4 , configured to provide a ratio T:A 4 which is at least 0.5:1, and which may be as high as about 1:1 or more in some embodiments. This ratio provides a transverse dimension T that is substantially larger than the transverse dimension T 3 of probe 108 . As discussed hereinabove, this relatively large dimension T, in combination with the inner concave configuration of the base, engages a surface 150 of an object to be inflated at a relatively large distance from probe 108 . As discussed hereinabove, this large distance provides a relatively large moment arm that effectively opposes typical transverse forces applied to probe 108 during insertion and/or use. As also discussed, this relatively large distance also defines a relatively large cross-sectional area that tends to distribute any axial forces that may continue to be applied upon full insertion of the needle.
Although concavo-convex base 104 , has been shown and described as being substantially semi-spherical, and base 304 has been shown as being frusto-conical, substantially any concavo-convex shape may be used, such as a cylindrical, box, dome shape, a series of spaced fingers, or other more complex concavo-convex configurations. Nominally any concavo-convex configuration may be used, which provides a concave surface facing the distal (insertion) end, to facilitate with a curved surface of the object to be inflated. In addition, while peripheries 114 are shown and described as being substantially circular, it should be understood that the various concavo-convex base configurations described herein may effectively form peripheries of nominally any configuration, including various polygonal or spoked configurations that may or may not provide an uninterrupted or continuous engagement with surface 150 . Rather, nominally any periphery configuration may be used, as long as it is capable of engaging a convex surface 150 at least two, and preferably at least three locations spaced radially about the axis of probe 108 upon insertion thereof. For example, a concavo-convex base may be fabricated as a series of fingers 304 ′ spaced about probe 108 , as shown in phantom in FIG. 3 , which may engage the surface of a ball at their tips.
As also shown, representative embodiments of probe 108 are provided with an axial dimension A 4 which may be within a range of about 30 mm to about 50 mm, and in particular embodiments, 35 mm to about 45 mm. Base 104 , 304 , 404 , etc., has an axial dimension A 3 which may be within a range of about 2 mm to about 6 mm, and in particular embodiments, about 3 mm to about 5 mm. Attachment end 102 and optional stem 212 ( FIG. 2 ) have axial dimensions A 1 and A 2 respectively, which are each within a range of about 5 mm to about 10 mm, or about 7 mm to about 9 mm in some embodiments. These embodiments may thus be provided with an overall axial dimension A within a range of about 40 mm to about 80 mm, and in particular embodiments, about 55 mm to about 65 mm.
Attachment end 102 and optional stem 212 are provided with transverse dimensions T 1 and T 2 which may both be within a range of about 5 mm to about 10 mm in some embodiments, and within a range of about 8-9 mm in others. Base 104 , 304 , 404 , etc., has an exterior transverse dimension T which may be within a range of about 15 mm to about 25 mm in various embodiments, and in particular embodiments, within a range of about 21 mm to about 23 mm. Exterior transverse dimension T 3 of probe 108 may be within a range of about 1 mm to about 4 mm in various embodiments, or about 2 mm to about 3 mm in other embodiments.
The following illustrative example is intended to demonstrate certain aspects of the present invention. It is to be understood that this example should not be construed as limiting.
Example
An inflation needle substantially as shown and described in FIG. 4 is injection molded as a single, unitary component, from a polymeric material. The needle includes a base 404 having an exterior transverse dimension T of about 22 mm, and a probe 108 having an axial dimension A 4 of about 40 mm, for a ratio T:A 4 of about 0.5:1.
Attachment end 102 and stem 212 both have axial dimensions A 1 and A 2 , respectively, of about 8 mm. Base 404 has an axial dimension A 3 of about 4 mm, to provide a total length A of about 60 mm.
Attachment end 102 and stem 212 have respective transverse dimensions T 1 and T 2 of about 8-9 mm. Probe 108 has an exterior transverse dimension T 3 of about 2 mm.
In the preceding specification, the invention has been described with reference to specific exemplary embodiments thereof. It will be evident that various modifications and changes may be made thereunto without departing from the broader spirit and scope of the invention as set forth in the claims that follow. The specification and drawings are accordingly to be regarded in an illustrative rather than restrictive sense. | 4y
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FIELD OF THE INVENTION
The invention concerns a cutting jet receptacle to be used on a fluid jet cutting machine.
BACKGROUND OF THE INVENTION
Fluid jet cutting machines have been used for many years to cut materials in sheets, such as plastic materials, paper, leather, rubber, metallic and composite materials formed of woven or non-woven superimposed layers impregnated with resin, etc.
On such machines, cutting of the material is effected by means of one or several nozzles, each delivering a fluid jet usually constituted by a high pressure water jet which, when required to cut metal materials, may often contain abrasive particles. Each jet is transmitted at extremely high speed, which may vary according to the materials to be cut. When the jet has completed its material cutting function, it is received in a receptacle designed in such a way as to absorb the residual energy which remains significant at the outlet of the material.
So as to carry out this function, mobile receptacles are normally used, which move at the same time as the cutting nozzle from the other side of the material to be cut, or fixed receptacles which extend over the entire width of the machine and opposite which the cutting nozzle moves.
In the case of mobile receptacles, the energy of the jet is generally absorbed by an interchangeable expendable part placed in the prolongation of the jet so that the latter strikes this part. The documents DE-A-3 518 166, U.S. Pat. Nos. 4,532,949 and 4,651,476 illustrate receptacles embodied according to this principle. In the document CH-A-567 908, the cutting jet strikes a liquid bath before arriving at the expendable part.
All these mobile receptacles require a large amount of maintenance owing to the presence of interchangeable expendable parts which need to be replaced frequently. Moreover, when a liquid is present above the expendable part, the receptacle may not be used in a slanted position.
As regards fixed receptacles illustrated in particular by the document U.S. Pat. No. 4,501,182, the energy of the jet may be absorbed by a liquid flowing in the bottom of the receptacle. However, in addition to the drawback linked to the spatial requirement of such a device, the latter may only be used in a virtually horizontal position, which excludes it being possible to orientate the cutting jet in a direction moved away from vertical.
In one particular case referred to in the document U.S. Pat. No. 2,985,050, an expendable elastomer material is placed below the liquid used to absorb most of the energy of the jet, and sprinkling ramps, placed below the level of the liquid in the receptacle and directed towards the point of impact of the cutting jet on the liquid, prevent too high a rise of the mist formed by the impact of the jet on the liquid. This device also exhibits the same drawbacks as the preceding device.
SUMMARY OF THE INVENTION
The object of the invention is to embody a mobile type cutting jet receptacle whose original conception enables it to suppress or at least highly minimize the wear of the parts constituting the latter, ensures that less maintenance is required and significantly increases the lifetime of said receptacle and makes it possible for it to be used irrespective of the orientation of the cutting jet, which may then vary between vertical and horizontal.
According to the invention, this result is obtained by means of a cutting jet receptacle for a fluid jet cutting machine, wherein said receptacle includes a hollow body having a cutting jet feed orifice kept in the alignment of this jet, at least one nozzle delivering inside this hollow body a fluid counter-jet along a certain orientation and under a certain pressure so that this counter-jet strikes the cutting jet and destroys it, and means for evacuating the fluid outside the hollow body.
In a receptacle embodied as above, the counter-jet(s) fulfill(s) a function similar to the function of expendable parts and/or the liquid bath in those receptacles of the prior Art. Maintenance is therefore considerably reduced and the receptacle may be used irrespective of the orientation of the cutting jet.
In one preferred embodiment of the invention, the receptacle includes at least two nozzles delivering counter-jets orientated in opposition with respect to the cutting jet traversing said orifice along directions inclined by a given angle with respect to one axis of the latter and distributed at regular intervals around this axis.
This disposition makes it possible to place a stand-by anti-splash plug pellet in the prolongation of the cutting jet above the impact of the latter on the counter-jets, which avoids the receptacle being damaged should a malfunction occur in these jets.
Advantageously, the hollow body is provided with an internal sheathing comprising a stand-by shoulder placed in the prolongation of the counter-jets delivered by the nozzles. This shoulder prevents the receptacle being damaged should a stoppage of the cutting jet occur without interrupting the counter-jets.
So as to eliminate the heat and mist generated by cutting and the impact of the jets inside the receptacle, the hollow body advantageously exhibits on its internal surface encompassing said feed orifice a recess with a semi-toric section extended by a concentration truncated surface situated between the feed orifice and the shoulder formed on the internal sheathing.
Elimination of heat and mist may also be favored by the presence of cooling means of the hollow body. These cooling means may include either a closed cooling circuit partly situated in the hollow body, or an open cooling circuit opening into the hollow body, or cooling ribs formed on the outer surface of the latter.
BRIEF DESCRIPTION OF THE DRAWINGS
There now follows a description of three preferred embodiments of the invention, given by way of example and being in no way restrictive, with reference to the accompanying drawings in which:
FIG. 1 is a longitudinal cutaway view representing a receptacle according to the invention and installed on a fluid jet cutting machine in the case of a first embodiment of the invention whereby this receptacle is cooled by an independent closed circuit;
FIG. 2 is a view similar to the one on FIG. 1 and representing a second embodiment of a receptacle according to the invention in which cooling is provided by an open circuit; and
FIG. 3 is a half-sectional view similar to the view on FIG. 2 and illustrating a third embodiment of the invention in which cooling of the receptacle is obtained by means of ribs formed on the body of the receptacle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
On FIG. 1, the reference 10 generally denotes a cutting jet receptacle embodied in accordance with the invention and installed on a fluid jet cutting machine whose disposition may be of any nature, said machine possibly being a manual control machine or a programmable machine. On this machine, the receptacle 10 is placed immediately below an aperture 14 formed in a horizontal table 12 supporting the part to be cut, said part being denoted by the reference 16. Above the part 16 and at the right of the aperture 14, the cutting machine comprises a cutting nozzle 18 opposite which the receptacle 10 is placed. The nozzle 18 and the receptacle 10 have a common axis which is shown vertical on FIG. 1 but whose orientation may possibly vary between vertical and horizontal by virtue of the use of the receptacle 10 of the invention.
The cutting nozzle 18 and the receptacle 10 are mounted on the machine so as to be able to move together opposite the aperture 14 along a generally transversal direction with respect to the machine, this direction being perpendicular to a longitudinal direction corresponding to the movement of the material 16 on the table 12. This simultaneous movement of the nozzle 18 and the receptacle 10 may be obtained by any device and especially by interconnecting these two members by a U-shaped arm laterally overlapping the part 16.
In operation, the cutting nozzle 18 emits a cutting jet 20 constituted by an under high pressure fluid jet which traverses the part 16 and then the aperture 14 before being collected in the receptacle 10. This cutting jet 20 is generally a water jet containing abrasive particles. It is transmitted at a high speed, usually supersonic.
The receptacle 10, in which this jet 20 is collected in accordance with the invention, is now to be described in more detail with reference to FIG. 1.
This receptacle 10 includes a hollow body 22 generally having a symmetry of revolution around an axis merged with the axis of the jet 20. This body 22 delimits an internal chamber 24 into which the jet 20 penetrates via a feed orifice 26 whose axis is also merged with the axis of the jet. This feed orifice 26 is formed in a bush 28 mounted on the body 22 and made of a material having extremely high resistance to abrasion. Adjustment means constituted by a screw 30 make it possible to move the bush 28 along the axis of the body 22 so that one extremity of this bush penetrates inside the aperture 14 and is found immediately close to the part 16 to be cut. The distance separating the bush 28 from the face of the part 16 opposite the cutting nozzle 18 may accordingly be accurately adjusted.
With regard to the direction of movement of the jet 20 inside the bush 28, the passage 26 successively has one approximately truncated convergent zone, one zone of reduced diameter and one zone of larger diameter opening into the internal chamber 24.
In its section situated opposite the bush 28, the body 22 of the receptacle 10 supports three nozzles 32 each transmitting a counter-fluid jet 34 along a direction which cuts the direction of the cutting jet 20 and orientated in the opposite direction with respect to the latter. The fluid transmitted by the nozzles 32 may be water. The pressure of the counter-jets 34 delivered by the nozzles 32 is adjusted by suitable means (not shown) placed in the feed pipes 3 of these nozzles. This adjustment is effected by taking account of the pressure of the cutting jet 20 so that, when the counter-jets strike the cutting jet, the latter is totally destroyed.
Each of the nozzles 32 is secured to the body 22 of the receptacle 10 so as to be able to move by means of a packing box 38 ensuring imperviousness of the chamber 24 with respect to the outside.
More precisely, the axes of the nozzles 32 and of the counter-jets 34 transmitted by these nozzles are orientated in opposition along directions inclined by a given angle of about 45° in the example represented with respect to the axis of the feed orifice 26, that is to the axis of the cutting jet 20. In addition, the three nozzles 32 are distributed at regular intervals around this axis, that is at 120° in relation to each other so that they simultaneously strike the cutting jet 20 and break it completely.
So as to evacuate the residual liquid resulting from the collision of the cutting jet 20 and the counter-jets 34, the body 22 is also imperviously traversed by an evacuation pipe 36 whose axis forms approximately the same angle as that of the nozzles 32 with the axis of the feed orifice 26 and which is disposed roughly between two of these nozzles. This pipe 36 opens into the internal chamber 24 which connects the latter to an effluent evacuation circuit (not shown) not forming part of the present invention.
The cutting nozzle 18 and the nozzles 32 transmitting the counter-jets 34 are normally controlled simultaneously so as to ensure that the cutting jet 20 or the counter-jets 34 do not damage the body 22 of the receptacle.
However, and so as to take into account any possible malfunctioning of the counter-jets 34, a stand-by anti-splash plug pellet 40 is mounted in the chamber 34 opposite the feed orifice 26 and between the nozzles 32, that is beyond the normal point of impact of the counter-jets with the cutting jet. This pellet 40, made of a material with extremely high resistance to abrasion, is placed in the prolongation of the cutting jet 20 so that the latter strikes it if the counter-jets 34 are not functioning properly. The pellet 40 is secured to the body 22 of the receptacle 10 by dismountable fixing means, such as a screw 42, making it possible, if need be, to replace it.
The circumferential surface of the chamber 24 is formed on an internal sheathing 44 of the body 22 made of a material having extremely high resistance to abrasion. This internal sheathing 44 comprises a stand-by shoulder 46 turned towards the nozzles 32 and the pellet 40. This shoulder 46 is localized so that the counter-jets 34 directly strike it in the event of any accidental stoppage of the cutting jet 20.
In the zone between this shoulder 46 and the feed orifice 26, the internal surface of the sheathing 44 comprises a truncated concentration surface 48 whose diameter from the orifice 26 to the shoulder 46 becomes smaller.
In its section encompassing the feed orifice 26, the extremity surface of the chamber 24 comprises a recess 50 with a semi-toric section formed directly in the body 22. This recess 50 extends the truncated concentration surface 48 and has the effect of bringing the mist, generated by cutting of the part and the impact of the jets inside the chamber 24, back to the evacuation pipe 36.
The elimination of this mist is also facilitated by cooling the receptacle 10.
In the embodiment shown on FIG. 1, this cooling is effected by causing a cooling fluid to circulate in a closed circuit, one part of this circuit being situated inside the body 22 of the receptacle. This part of the circuit internal to the body of the receptacle includes a helical groove 52 formed in the body 22 and interiorly delimited by the sheathing 44. The cooling liquid penetrates this groove 52 via a pipe 54 situated close to the nozzles 32 and leaves it via a pipe 56 situated close to the bush 28. Between the pipes 54 and 56, the cooling circuit conventionally includes means 57 to cool the cooling fluid, as well as a pump 59.
FIG. 2 shows a second mode for embodiment of the receptacle of the invention. In this second embodiment, the members corresponding to those of the first embodiment are denoted by the same reference figures increased by 100.
The receptacle 110 of FIG. 2 has general characteristics identical to those of the receptacle 10 described above with reference to FIG. 1. It is mainly distinguished from the latter by the structure of the cooling means of the body 122 of this receptacle. In effect, if these cooling means also include a helical groove 152 formed in the body 122 around the axis of the latter and interiorly delimited by the sheathing 144, the extremity of the groove 152 closest to the nozzles 132 opens directly inside the chamber 124 via a passage 158. In this case, the cooling liquid is introduced into the groove 152 via a pipe 156 at its extremity closest to the bush 128 and is evacuated with the other effluent via the pipe 136.
In the embodiment shown on FIG. 3, the receptacle of the invention also has general characteristics identical to those of the receptacle described previously with reference to FIG. 1. Accordingly, the members identical to the latter are denoted by the same reference figures increased by 200.
As in the case of FIG. 2, the receptacle of FIG. 3 is mainly distinguished from that of FIG. 1 by the structure of the cooling means of the body 222 of this receptacle 210. In this case, the cooling of the body is simply ensured by providing cooling ribs 260 on the outer surface of the latter in its cylindrical part.
Regardless of the embodiment used, the destruction of the cutting jet by means of one or several counter-jets makes it possible to suppress the expendable parts or at least significantly increase their period of life. Moreover, a receptacle designed in this way may be used irrespective of the orientation of the cutting jet between vertical and horizontal. Furthermore, these described embodiments make it possible to ensure that the mist generated by the cutting and impact of the jets inside the receptacle does not reach the part to be cut.
Of course, the invention is not merely limited to the embodiments described above by way of examples, but covers all its variants.
In particular, the number of nozzles delivering the counter-jets used to destroy the cutting jet may be other than three without departing from the context of the invention. If a single nozzle is used, it is placed directly in the axis of the cutting jet, whereas when several nozzles are used, the latter are slanted with respect to this axis, as in the embodiments described. This latter situation is preferable, as it makes it possible to destroy either the cutting jet or the counter-jets by virtue of the pellet 40 and the shoulder 46 should any malfunction occur of respectively the counter-jet delivering system or the cutting jet delivering system. | 4y
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This is a divisional application of application Ser. No. 09/968,584, filed Oct. 1, 2001; which was a continuing application, under 35 U.S.C. §120, of International application PCT/EP00/02681, filed Mar. 27, 2000; the application also claims the priority, under 35 U.S.C. §119, of German patent application No. 199 14 013.8, filed Mar. 29, 1999; the prior applications are herewith incorporated by reference in their entirety.
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The invention relates to a fuel element for a pressurized water reactor, with a laterally open skeleton containing control-rod guide tubes, to which are fastened a plurality of spacers and also a fuel element head and a fuel element foot. Gastight multilayer cladding tubes are inserted into the skeleton and in each case surround a column of fuel pellets. FIG. 1 illustrates a fuel element of this type, with a head 1 , a foot 2 and spacers 3 and 4 that are fastened to guide tubes 5 , thus producing a laterally open skeleton, into which fuel rods 6 are inserted. During operation, cooling water flows from the bottom upward through the fuel element and can also enter adjacent fuel elements laterally from the interspaces between the fuel rods. It can also be seen from FIG. 1 that additional mixing grids 7 , which serve as carriers for flow guide blades, may be provided between the spacers 4 in an upper part of the fuel element. Such flow guide blades are advantageously likewise provided in the upper part of the fuel element, at least on a top side of the spacers 4 , in order to achieve a turbulent mixing of the cooling water and a better flow onto the fuel rods 6 .
[0003] Corresponding blades are described, for example, in Published, Non-Prosecuted German Patent Application DE 15 64 697 A and are reproduced in FIG. 2 . It is also possible, however, to have other spacers (for example, formed of sleeves welded to one another) and other geometries of flow guide blades 8 , while a different number of mixing vanes may also be provided in the interspaces between adjacent fuel rods 6 .
[0004] In the pressurized water reactor, only a small fraction (normally at most 5%) of the liquid cooling water is evaporated on the outer surfaces of the fuel rods, on the contrary the heat generated in the fuel by nuclear fission is discharged essentially in that water having a corresponding temperature and maintained under high pressure is transported away by convection. In contrast, a boiling water reactor operates with lower pressure and lower temperatures, the heat from the fuel rods being transported away, at least in the upper part of the fuel element, essentially by isothermal evaporation in a two-phase mixture. In this case, it is necessary to channel the steam that occurs. The fuel elements are therefore surrounded laterally by fuel element boxes.
[0005] The techniques of the boiling water reactor and of the pressurized water reactor have developed in different directions. For the purpose of plant protection and for similar reasons, the pressurized water has admixed with it, for example, lithium hydroxide and similar additives which cannot be used in boiling water and lead to a different water chemistry (for example, a different oxygen concentration). The size and number of fuel rods in the fuel elements and the configuration of control elements in the reactor core are also different. The differences in the temperature and pressure of the cooling water also lead to different loads on the cladding tubes and to a different behavior of the fuel, in particular to different time constants of the reactor core when the latter is considered as a self-contained control system with feedback.
[0006] The result of this different control behavior is that the power output of pressurized water reactors is changed only very slowly, that is to say the pressurized water reactor is operated almost virtually in the steady state and is suitable particularly for covering basic loads. For covering peak loads of the consumer connected to the reactor, boiling water reactors, the power output of which is run up, for example, substantially more quickly and in a ramp-like manner, are more suitable. The result of this is that the cladding tubes, which are already exposed on their outer surface, according to the different water chemistry and operating temperatures, to different chemical loads (for example, nodular corrosion in the boiling water reactor or uniform corrosion in the pressurized water reactor) and have to withstand different operating pressures, are also subjected to different loads on the inside.
[0007] The outcome of this has been that the cladding tubes of boiling water reactors are formed, as a rule, of a different alloy (to be precise, zircaloy-2) from the cladding tubes of pressurized water reactors for which zircaloy-4 was developed. A zirconium alloy with 2.5% niobium, which is also used in Russian light-water cooled reactors, is also known for the pressure tubes of high-temperature reactors.
[0008] Table 1 indicates the standardized composition of industrially pure zirconium for the nuclear industry (so-called “zirconium sponge”), zircaloy-2 (“zry-2”), zircaloy-4 (“zry-4”) and zirconium niobium (“Zr/Nb”), oxygen being considered as an impurity acceptable in small quantities, even when, because of its hardening effect on zirconium, it is often desirable and is therefore added.
[0009] If use is made of a higher enrichment of the fuel pellets with fissionable isotopes of uranium and/or plutonium and therefore of a greater useful energy content (so-called “burn-up”) of the fuel, then the fuel elements can remain in the core for longer, should their cladding tubes be capable of meeting the corresponding requirements due to the longer service life. Therefore, in pressurized water fuel elements, the outer surfaces of the cladding tubes must be particularly resistant to the uniform corrosion occurring in the pressurized water and should not be pressed onto the fuel by the increased pressure, even in the event of relatively long service lives, in such a way that they thereby experience damage. In the development of cladding tubes that meet the increased requirements of a longer service life in the pressurized water reactor, it is therefore necessary to pay particular attention to the mechanical stability of the entire tube and to the resistance of the outer surface to uniform corrosion.
[0010] These conditions are fulfilled satisfactorily by single-layer cladding tubes, such as are described in European Patent EP 0 498 259 B and, in general, consist of zirconium with 0.8 . . . 1.7% Sn, 0.07 . . . 0.5% Fe, 0.05 . . . 0.35% Cr, 0.07 . . . 0.2% O, up to about 0.015% Si and up to a maximum of 0.1% Ni. In this context, it has proved particularly important that the metals, Fe, Cr and Ni, which are virtually insoluble in zirconium and are precipitated (so-called “secondary precipitations”) as intermetallic compounds (“secondary phases”), have an average particle size of about 0.1 to 0.3μ. The particle size is set by the thermal treatment to which the alloy is subjected after it has first been brought to a temperature at which the precipitations are dissolved (so-called “solution annealing”) and has then been rapidly cooled (so-called “quenching”). The resulting size and distribution of the secondary precipitations can be calculated by a “particle growth parameter” and in manufacturing practice are set by a cumulative “standardized annealing duration” A
A=Σt i ·exp(− Q/T ),
in which T is the temperature in Kelvin during a manufacturing step i, t i is the duration of the manufacturing step and Q corresponds to an activating energy, and the value Q=40,000 Kelvin may be adopted.
[0011] FIG. 3 shows the daily growth of the uniform oxidation layer on the surface of a cladding tube formed of zircaloy-4 in a pressurized water reactor at operating temperatures of about 300° C. as a function of the standardized annealing duration A which was used in the production of the cladding tube. In general, for pressurized water reactors, standardized annealing durations of between 2·10 −18 and 50·10 −18 hours are considered favorable for zircaloy-like alloys of this type, such as are described in European Patent EP 0 498 259 B (Garzarolli et al. in “Zirconium in the Nuclear Industry: Eighth International Symposium”, Philadelphia 1989 (ASTM Special Technical Publication 1023), pages 202 to 212). However, such a high annealing duration conflicts with the efforts of a person skilled in the art, by a pilgrim-step method with cold formings, to break down the alloy grain, which likewise ripens into large grains at high temperatures, into small grains by cold formings, in order to increase the mechanical stability of the cladding tube, since a fine grain leads to high stability along with high ductility. Consequently, according to the patent specification mentioned, the high standardized annealing duration is achieved by the quenched material first being forged, still at a high temperature, before it is extruded to form a tube blank and is then cold-formed in subsequent pilgrim steps with moderate intermediate annealings.
[0012] Another way is to have a composite tube that, as a so-called “duplex”, formed of a relatively thick matrix layer with a thin outer protective layer formed of another zirconium alloy. The matrix ensures the necessary mechanical stability, while the outer protective layer is resistant to the uniform corrosion posing a threat in the pressurized water reactor. Such a duplex is described for the first time in European Patent EP 0 212 351 B, where 0.1 to 1% V and up to 1% Fe is used as alloying additives for the outer protective layer. European Patent EP 0 301 395 B describes a duplex, in which the outer alloy contains 0.2 to 3% Nb and/or a total content of Fe, Cr, Ni and Sn of between 0.4 and 1% (remainder: in each case zirconium of industrial purity). It is known from European Patent EP 0 630 514 B that an outer layer of this type for a zircaloy matrix may also contain a larger total content of Fe, Cr, Ni, Sn, insofar as specific restrictions are maintained for the individual alloying additives, in particular the tin content is below the tin content of the zircaloy. The cladding tubes mentioned have proved appropriate, even under the operating conditions of the pressurized water reactor, and make it possible to achieve the desired long service lives.
[0013] The graph of FIG. 3 would be entirely different in the case of a boiling water reactor. There, because of the lower operating temperatures, virtually no uniform corrosion occurs, but oxide pustules are formed. Here, high secondary precipitations cannot act as any of the pustules that, however, are avoided when the material of the secondary phases is finely distributed and has undergone only a particularly low standardized annealing duration. Often, however, cladding tubes of boiling water fuel rods exhibited corrosion damage that emanated from inside the tubes and was attributed to stress crack corrosion. Such damage was minimized by a composite tube, in which a matrix of zircaloy had on the inside a protective layer of industrially pure zirconium, that is to say a soft material, but one susceptible to corrosion. In this case, however, the susceptibility of pure zirconium to corrosion is a disadvantage, since the situation is unavoidable where, in rare instances, due to slight damage in the tube, water from the boiling water reactor enters the cladding tube interior and then triggers corrosion leading to extensive cracks by which the water of the reactor may be contaminated to a substantially greater extent than by a multiplicity of fuel rods with locally limited damage. Instead of a protective layer of pure zirconium, therefore, a protective layer is often used, in which the zirconium contains up to 1% of another alloying additive. Thus, European Patent EP 0 726 966 B describes a cladding tube with a thick matrix layer of zircaloy, in which the secondary precipitations have a particle size of between about 0.03 and 0.1μ, and a lining of zirconium with 0.2 to 0.8% iron is bonded metallurgically to the inside.
[0014] The composite tube is particularly advantageous in the boiling water reactor, because, due to the small size of the secondary precipitations on the outer surface, a particularly low A-value becomes necessary, which, in the case of the appropriate alloying of the protective layer on the inside of the cladding tube, likewise brings about only a slight growth of secondary precipitations and grain, so that the inside is both protected more effectively against corrosion and remains soft because it is not subject to any excessive dispersion hardening as a result of Fe secondary precipitations.
[0015] However, a cladding tube of this type, configured for boiling water conditions, is entirely unsuitable for pressurized water applications, since the small size of the secondary precipitations on the outer surface would accelerate the uniform corrosion and necessitate an exchange of the cladding tube even after short service lives. On the other hand, the inner lining is not necessary, even under the operating conditions of the pressurized water reactor which have existed hitherto, since, up to now, no damage emanating from the inner surface (stress crack corrosion) has been observed. Moreover, the power output of the pressurized water reactors is not changed rapidly in the ramp-like manner, as is customary in boiling water reactors. Instead, the control conditions of the pressurized water reactor make it necessary, in any case, for the power output to be changed only slowly, there being predetermined for the control a rate of change which also takes account of the fact that the cladding tubes are not to be subjected to inadmissible stress.
[0016] In the case of a higher enrichment of the fuel and longer service lives, even the behavior of the fuel itself must be taken into consideration. Since a multiplicity of gaseous fission products occur during decomposition, the fuel swells and thereby experiences an enlargement of volume which leads to a widening of the cladding tube, especially since the latter, in the course of time, particularly under the higher pressures of the pressurized water reactor, is compressed and creeps onto the fuel. When the fuel, which is in contact with the inside of the cladding tube even at a low reactor power output, is quickly heated as a result of a rapid increase in power output customary in the boiling water reactor, however, the thermal expansion of the fuel constitutes an additional load on the cladding tube. In configuration terms, the loads can be taken into account in as much as a gas collecting space is provided at least in the upper end of the fuel rods, a gap is left free between the cladding tubes and the fuel pellets and the fuel element is efficiently and quickly cooled, for example by the initially mentioned flow guide blades on the spacers and, if appropriate, additionally introduced intermediate grids. The load has hitherto been unimportant in the control of the power output of pressurized water reactors, since, in any case, in control terms a restricted rate of change of the power output seems permissible.
SUMMARY OF THE INVENTION
[0017] It is accordingly an object of the invention to provide a fuel element for a pressurized water reactor and a method for producing cladding tubes that overcome the above-mentioned disadvantages of the prior art devices and methods of this general type, which, on the one hand, can remain in the reactor for a sufficiently long time and, on the other hand, allows a more flexible operation of the pressurized water reactor, in particular use of the pressurized water reactor for covering peaks in demand of the consumer or power supply network connected to the reactor. In particular, the object, at the same time, is to produce a cladding tube suitable for the novel fuel element.
[0018] With the foregoing and other objects in view there is provided, in accordance with the invention, a fuel element for a pressurized water reactor. The fuel element contains a laterally open skeleton having control-rod guide tubes each with a first end and a second end, spacers fastened to the control-rod guide tubes, a fuel element head disposed at the first end of the control-rod guide tubes, and a fuel element foot disposed at the second end of the control-rod guide tubes. Gastight cladding tubes are inserted into the skeleton and each is filled with a column of fuel pellets. At least some of the gastight cladding tubes have a multilayer wall. The multilayer wall is formed of a mechanically stable matrix containing a first zirconium alloy disposed in a middle of the multiplayer wall; and a thinner protective layer of a second zirconium alloy alloyed to a lesser extent than the first zirconium alloy. The thinner protective layer is bound metallurgically to the matrix and is disposed on an inside of the matrix facing the fuel pellets.
[0019] The invention proceeds, in this case, from the knowledge that the control restrictions in the control of the power output make it possible per se to have greater rates of change in the power output of a pressurized water reactor than has been conventional hitherto. Flexible operation would therefore be possible if the fuel element were also to withstand the loads occurring during rapid load changes.
[0020] To achieve the object, the invention provides the fuel element with a laterally open skeleton containing the control-rod guide tubes, to which are fastened the spacers, the fuel element head and the fuel element foot. Inserted into the skeleton are the cladding tubes which in each case surround a column of fuel pellets in a gastight manner, at least some cladding tubes each having a multilayer wall. In the middle of the wall is located, according to the invention, a mechanically stable matrix of a first zirconium alloy, alloyed to a greater extent, to which a thinner protective layer of a second zirconium alloy alloyed to a lesser extent is bound metallurgically. The protective layer is in this case located on the matrix inside facing the fuel pellets. Preferably, the two zirconium alloys have precipitations of secondary phases that, by thermal treatments with different standardized annealing durations, are ripened to a different average size.
[0021] The invention is in this case based on the fact that the configuration of the fuel element satisfies all hydraulic and cooling requirements of relatively long operation under full load or part load, particularly when at least the spacers in an upper part of the fuel element carry, on their side facing away from the flow of pressurized water, flow guide blades for intermixing the pressurized water. The configuration of the fuel rods can also satisfy these requirements, particularly when the cladding tubes are filled with a gas of increased pressure and have a gas collecting space (“plenum”) at least at the upper end and the pellets are introduced with an annular gap in relation to the inner surface of the cladding tube.
[0022] Moreover, the invention also takes account of the fact that a matrix, in particular when it has the features described in European Patent EP 0 498 259 B, is already sufficiently corrosion-resistant for relatively long operation under full load. If appropriate, a further protective layer, such as is described, for example, in European Patents EP 0 212 351 B, EP 0 301 295 B or EP 0 630 514 B mentioned, may also be bonded metallurgically around the matrix on the outside of the cladding tube.
[0023] A matrix of this type, formed of a zircaloy-like zirconium alloy (1 to 1.8% by weight Sn; 0.2 to 0.6% by weight Fe; up to 0.3% by weight Cr; remainder: industrially pure zirconium, if appropriate with an oxygen content of up to 2.0%), best displays the desired properties when it is treated with a standardized annealing duration A of between 2 and 80·10 −18 hours.
[0024] Another preferred possibility for a matrix having the desired properties is a zirconium alloy with 0.8 to 2.8% Nb (if appropriate, up to 2.7% of further additives, remainder: zirconium of industrial purity, including, if appropriate, an oxygen content of up to 2.0%). Preferably, in this case, the quantity of further additives is below the quantity of the niobium. However, such a niobium-containing zirconium alloy displays the most favorable properties when it is subjected to a substantially lower standardized annealing duration, in particular A lower than 0.5·10 −18 h.
[0025] Admittedly, the mechanical stability of the alloys is not so high that they ensure the annular gap for a relatively long time and could prevent the cladding tube from creeping down onto the fuel. The alloys overcome the fact that the cladding tube is widened again due to the growth in volume of the fuel after relatively long service lives. The alloys also withstand load changes during which the power output falls considerably below the maximum value for only a short time and is soon raised again to the maximum value.
[0026] To control the power output, however, the rate of change must be adapted to the most unfavorable case. This occurs when, during the operation of the reactor, a plurality of load changes have already taken place and then only part-load operation takes place for a relatively long time, in which the fuel contracts thermally and a renewed creeping of the cladding tube consequently occurs. There is then the threat of sudden loads when the reactor is quickly run up again and the fuel expands thermally again. This, in actual fact, requires a particularly high ductility of the cladding tube, which, however, would itself be conducive to undesirably rapid creeping.
[0027] Moreover, when, by the control elements being moved out, the reactor is run up from a state in which it was operated only under part load, with control elements inserted partially into the reactor core, the fuel pellets adjacent to the control elements which are moving past experiencing a sudden thermal load, since they were previously protected by the control elements from the high neutron flux to which they are then suddenly exposed. The pellets, which were initially intact according to FIG. 4 , therefore shatter and experience a structural change evident from FIG. 5 . In this case, individual fragments of a shattered pellet may be displaced and press locally against the inside of the cladding tube. It must therefore be assumed that, after a lengthy period under part load, close contact occurs at least locally between the fuel rod and the fuel (“deconditioning”) and then, in the case of a sudden thermal change in volume of the fuel, generates considerable stresses in the cladding tube.
[0028] If the cladding tube is formed completely of the alloys mentioned hitherto, only slow increases in power output would therefore nevertheless be possible. According to the invention, however, the stresses are absorbed by the protective layer bound metallurgically to the inside of the matrix and formed of the zirconium alloyed to a lesser extent, the protective layer formed preferably of zirconium of industrial purity which is alloyed with 0.2 to 0.8% by weight of iron. As a rule, the second zirconium alloy contains more than 0.3% by weight, preferably at least 0.35% of iron. The preferred maximum value is around 0.5 or, in any event, is below 0.6%.
[0029] However, the alloy displays the most favorable properties when the precipitations of the secondary phases have an average size which corresponds to a standardized annealing duration of about 0.1 . . . 3·10 −18 h.
[0030] Such small secondary precipitations of a ZrSe alloy on the inside of the cladding tube are known from the initially mentioned European Patent EP 0 726 966 B and can be manufactured from a composite tube blank produced by the coextrusion of tubes inserted one into the other, but the result of the further processing of the blank is that, after quenching, the two layers acquire either a high A-value, this being detrimental to the action of the protective layer, or a low A-value, that is to say the outside also has correspondingly fine secondary precipitations, which conforms to the requirements of a boiling water reactor, but is harmful to a pressurized water reactor.
[0031] However, different precipitation sizes on the inner surface and the outer surface of a cladding tube can be produced by a method that is known as “partial quenching”. In this, in the case of a cladding tube which already possesses relatively large secondary precipitations due to relatively long annealing durations, the inside is maintained at a low temperature by a coolant stream, while the outside is increased briefly (for example, inductively) to solution temperature. During cooling, a fine dispersion of precipitations occurs on the outside, that is to say, ultimately, a “metallurgic gradient” with respect to the precipitations in the cladding tube is generated. However, the result of the “metallurgic gradient” is precisely that there are substantially finer secondary precipitations on the outside than on the inside, that is to say precisely the distribution likewise suitable only for boiling water, if both layers are formed of a niobium-free ZrFe alloy.
[0032] The “partial quenching” is complicated, but is possible, at least theoretically, in the case where the matrix is formed from a ZrNb alloy.
[0033] However, such a cladding tube with a matrix of ZrNb, which is bonded metallurgically to the inside of the cladding tube by a protective layer of ZrFe, can also be produced by the two zirconium alloys first being thermally treated independently of one another, in each case solution annealing, with subsequent different standardized annealing durations A, being carried out. From the first zirconium alloy and at least the second zirconium alloy, a multilayer composite tube is then produced, the wall of which contains in the middle a thick layer of the first zirconium alloy as the matrix, a protective layer of the second alloy being bonded metallurgically to the inside of said wall. The composite tube is then processed further into the finished cladding tube, in such a way that the two layers are in this case subjected to virtually the same thermal conditions, without solution annealing.
[0034] In this case, the second zirconium alloy is treated, up to the completion of the cladding tube, with a standardized annealing duration which differs by at least 80% from the standardized annealing duration to which the first zirconium alloy is subjected up to the completion of the cladding tube. Preferably, even before the production of the composite tube, the second zirconium alloy is subjected to a standardized annealing duration of between 0.1·10 −18 h and 3·10 −18 h, advantageously at most to a standardized annealing duration of below 2·10 −18 h.
[0035] Preferably, at all events, before the production of the composite tube, a zirconium alloy with 0.8 to 2.8% niobium is treated with a lower standardized annealing duration than the zirconium alloy of the protective layer.
[0036] However, a similar method with the same composition and similar treatment of the protective layer (at most a standardized annealing duration of below 3·10 −18 h, advantageously below 2·10 −18 h) can also be adopted when a zirconium alloy of 1 to 1.8% Sn; 0.2 to 0.6% Fe; up to 0.3% Cr (remainder: industrially pure zirconium) is used as matrix, although the matrix should be treated with a standardized annealing duration of 2 to 80·10 −18 h before the production of the composite tube.
[0037] For the further processing of the composite tube to form the finished cladding tube, forming steps are necessary (in particular pilgrim steps), between which intermediate annealing is carried out in each case. At the same time, a maximum standardized annealing duration (for example, 3·10 −18 h) is preferably also maintained for this further processing. Even annealing durations of below 2·10 −18 h can easily be controlled in manufacturing terms.
[0038] Insofar as increased protection of the outer surface against uniform corrosion is desired, during the production of the composite tube a third zirconium alloy may also be bound metallurgically to the first zirconium alloy.
[0039] In accordance with an added feature of the invention, the second zirconium alloy contains at least 0.2% by weight of iron, a remainder being zirconium of industrial purity.
[0040] In accordance with an additional feature of the invention, an iron content of the second zirconium alloy is 0.40±0.04% by weight.
[0041] In accordance with another feature of the invention, the second zirconium alloy has precipitations of secondary phases, a size of which corresponds to a standardized annealing duration of about 0.1 to 3·10 −18 h.
[0042] In accordance with a further feature of the invention, the first zirconium alloy contains 1.3±0.1% Sn; 0.28±0.04% Fe; 0.16±0.03% Cr; 0.01±0.002% Si and 0.14±0.02% O.
[0043] In accordance with a further added feature of the invention, the first zirconium alloy has precipitations of secondary phases, a size of which corresponds to a higher standardized annealing duration than an annealing duration to which a size of the precipitations in the second zirconium alloy corresponds.
[0044] In accordance with a further additional feature of the invention, the size of the precipitations in the first zirconium alloy corresponds to a standardized annealing duration of 2 to 80·10 −18 h.
[0045] In accordance with another further feature of the invention, the first zirconium alloy is formed of 0.8 to 2.8% niobium and zirconium of industrial purity and also at most 2.7% of further additives.
[0046] In accordance with another added feature of the invention, in the first zirconium alloy, a quantity of the further additives is smaller than a quantity of the niobium.
[0047] In accordance with another additional feature of the invention, the first zirconium alloy contains 1.0±0.2% niobium, 0.14±0.02% oxygen, a remainder being the zirconium of industrial purity.
[0048] In accordance with an added feature of the invention, the first zirconium alloy contains precipitations of secondary phases, a size of which corresponds to a lower standardized annealing duration, as compared with the second zirconium alloy.
[0049] In accordance with an additional feature of the invention, flow guide blades are provided, and at least the spacers in an upper part of the fuel element carry, on a side facing away from a flow of pressurized water, the flow guide blades for intermixing the pressurized water.
[0050] In accordance with another feature of the invention, the gastight cladding tubes each have an upper end with a plenum formed therein at the upper end, and including a gas of an increased pressure filling the gastight cladding tubes.
[0051] In accordance with a further feature of the invention, the column of fuel pellets have ends and bodies containing virtually no fissionable material disposed at the ends.
[0052] In accordance with another added feature of the invention, a further protective layer of a third zirconium alloy which is thinner than the matrix and is bonded metallurgically to an outside of the multilayer wall.
[0053] In accordance with another additional feature of the invention, the second zirconium alloy contains at least 0.30% by weight of iron, a remainder being zirconium of industrial purity. Optionally, the second zirconium alloy contains up to 0.8% by weight of iron, the remainder being zirconium of industrial purity. Alternatively, the second zirconium alloy contains at most 0.6% by weight, of iron, the remainder being zirconium of industrial purity.
[0054] In accordance with another further feature of the invention, the first zirconium alloy contains at least 1.2% Sn, at least 0.24% Fe and at least 0.10% Cr, a remainder being zirconium of industrial purity. Optionally, the first zirconium alloy contains at most 1.5% Sn, at most 0.5% Fe and at most 0.25% Cr, a remainder being zirconium of industrial purity.
[0055] In accordance with a concomitant feature of the invention, the size of the precipitations in the first zirconium alloy corresponds to a standardized annealing duration of 30±10·10 −18 h.
[0056] Other features which are considered as characteristic for the invention are set forth in the appended claims.
[0057] Although the invention is illustrated and described herein as embodied in a fuel element for a pressurized water reactor and a method for producing cladding tubes, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
[0058] The construction and method of operation of the invention, however, 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 DRAWINGS
[0059] FIG. 1 is a diagrammatic, side-elevation view of a pressurized water fuel element according to the invention;
[0060] FIG. 2 is a fragmentary, perspective view of guide blades that are advantageous at least on some spacers or intermediate grids;
[0061] FIG. 3 is a graph showing a corrosion rate on the parameter A of the standardized annealing duration on a surface of a pressurized water fuel rod;
[0062] FIGS. 4 and 5 are cut-away, perspective views of a described state of a fresh fuel pellet before and after a ramp-like increase in power output;
[0063] FIG. 6 is a cross-sectional view of an advantageous interior of a fuel rod;
[0064] FIG. 7 is a perspective view of a cladding tube according to the first preferred exemplary embodiment;
[0065] FIG. 8 is a graph showing phase ranges of the alloys used as a matrix in the two preferred exemplary embodiments;
[0066] FIG. 9 is a flow diagram of method steps for producing the first exemplary embodiment;
[0067] FIG. 10 is a perspective view of the cladding tube according to the second preferred exemplary embodiment; and
[0068] FIG. 11 is a flow diagram of the method steps for the production of the second exemplary embodiment.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0069] Referring now to the figures of the drawing in detail and first, particularly, to FIG. 6 thereof, there is shown a cladding tube 10 of the fuel rods 6 is in each case closed in a gastight manner at upper and lower ends by an end plug 11 . At the upper end a spring 12 subjected to compressive stress ensures that a corresponding plenum 13 is maintained at least at the upper end. A column of fuel pellets 14 contains in each case, at its upper and lower end, a body 15 that contains virtually no fissionable material and may consist, for example, of aluminum oxide or else natural uranium or depleted uranium. In this case, in order to increase conductivity between the pellets 14 and the cladding tube 10 , the cladding tube 10 is filled with a high-pressure gas (for example, helium).
[0070] In the present case, a supporting body 16 at the lower end of the fuel rod also keeps free a corresponding plenum.
[0071] The outside diameter of the cladding tube is about 9.55 mm, and its wall thickness is about 0.61 mm. According to FIG. 7 , a cladding tube 20 is formed of a matrix 21 , the thickness of which is about 75 to 95% of a cladding tube wall. A protective layer 22 is bound metallurgically to the matrix 21 on the inside of the cladding tube 20 , and it is also indicated that a further protective layer 22 ′ may also be attached to the outside.
[0072] Table 2 indicates the lower and upper limit values for the composition I of the matrix 21 . Here, the values given in brackets in each case describe preferred relatively narrow limits for the contents of the individual alloy constituents or the particularly preferred limit values for the accompanying elements of the alloy constituents which are already contained as impurities in the zirconium of industrial purity (“sponge”, see Table 1) and can be maintained for the lower limits which are also advantageous, as in the case of oxygen or silicon.
[0073] In the preferred exemplary embodiment, the matrix 21 contains 1.3±0.1% Sn; 0.28±0.04% Fe; 0.16±0.03% Cr; 0.01±0.002% Si and 0.14±0.02% O. The size of the precipitated secondary phases is in this case 30·10 −18 h.
[0074] The protective layer 22 consists of 0.4±0.04% Fe and zirconium sponge, the precipitation size being determined by A=1·10 −18 h.
[0075] In the second phase, the precipitations consist virtually of intermetallic ZrFe compounds, in the case of the matrix 21 of mixed compounds of zirconium with iron and chromium, and, in FIG. 8 , it can be seen under I that, up to temperatures of about 820° C., there is an α-phase of ZrSn in addition to the corresponding secondary phase γ of these precipitations. In the range between about 820 and 960° C., there is also a β-phase of ZrSn in addition to the α-phase, and at about 840° C. (“solution temperature”) the γ-phase of the intermetallic compounds becomes a solution. Above 960° C., only the β-phase with the dissolved precipitations is still stable. If, therefore, the matrix is heated into the β-range (temperatures of above 960° C.) and is then rapidly cooled, a fine-grained α-phase is first formed, in which part of the iron is distributed in a finely dispersed manner as precipitations of the γ-phase, while the rest of the iron remains bound as metastable supersaturation in the α-phase. In this case, the finely dispersed precipitations correspondingly form nuclei, on which the excess iron fraction is accreted the more rapidly and the more highly, the higher the temperature and duration in which the matrix material is exposed to further thermal treatments in the α-range (temperatures of below 820° C.).
[0076] To produce the cladding tube 20 , first, the first alloy of ZrSnFeCr, provided for the matrix 21 , is remelted a plurality of times under a vacuum in a step 30 a ( FIG. 9 ) to homogenize the alloy constituents, in a step 31 a the alloy is forged to a shape suitable for the processing of a tube blank and, in a further step 32 a , the alloy is rapidly cooled (“β-quench”) from a temperature in the β-range (above 960° C.). This may be followed by further forging (step 33 ), the first tube blank Ra being produced at the latest during a step 34 . The step 34 is also followed by further annealings, in order to set the parameter A=30·10 −18 h in the first tube blank.
[0077] In a similar way, the second zirconium alloy (ZrFe) provided for the protective layer 22 is likewise remelted in a step 30 b , in a step 31 b is heated into the β-range (temperatures of above 960° C.) and in the step 32 b is rapidly cooled. During these steps, a second tube blank Rb is also produced. In this case, the β-quenching (step 32 b ) is followed by virtually no further heating, instead the two blanks, the shapes of which have been adapted to one another, are placed one into the other, welded to one another and jointly extruded in a step 35 . This coextrusion does not, in practice, contribute to the ripening of the precipitations, so that, in the composite tube obtained, the matrix material possesses the value A=30·10 −18 h and the second zirconium alloy possesses virtually the value A=0. Subsequently, a plurality of pilgrim steps 36 are carried out, between which brief annealings at temperatures well below 820° C. are carried out in each case, in order to recover the cold-formed material and prepare it for the next pilgrim step. What is then achieved by terminal annealing 37 is that the parameter A=1·10 −18 h is set for the entire processing of the composite tube to form the finished cladding tube, that is to say the first zirconium alloy of the matrix has the value A=31·10 −18 h, but the second zirconium alloy of the protective layer has the value A=1·10 −18 h.
[0078] For steps 33 and 34 , a range A=2 to 80·10 −18 h is maintained, values of above 5·10 −18 h being advantageous.
[0079] Values of above 60·10 −18 h signify long annealing durations at high temperatures which do not seem necessary. For steps 35 to 37 , in general, values A of below 2·10 −18 may be maintained. For the finished zirconium alloy of the matrix, therefore, values A=5 to 60·10 −18 h seem advantageous, while A=1 to 3·10 −18 h should be maintained for the second zirconium alloy of the protective layer.
[0080] In the second exemplary embodiment according to FIG. 10 , a cladding tube 40 is formed of the matrix 41 with the composition 1.0±0.2% Nb, 0.14±0.02% O, remainder: zirconium of industrial purity, see Table 2 indicating under II the preferred limits for the constituents in similar compositions.
[0081] It can be seen in FIG. 8 , under II, that, in the phase diagram of the alloy, at temperatures of up to 580° C. there is a stable α-phase in which about half the niobium is dissolved, while the remainder is precipitated as a stable β-phase of the niobium. At 580° C., there is a mixed phase α+β, in which virtually all the niobium is dissolved, while, at temperatures of above 960° C., only a β-phase of the zirconium, with the completely dissolved niobium, still exists.
[0082] The second zirconium alloy in a protective layer 42 of the cladding tube 40 is formed of the same ZrFe alloy as in the first preferred exemplary embodiment already described.
[0083] To produce the cladding tube 40 , a diagram according to FIG. 11 , similar to that of FIG. 9 , is obtained. In this case, however, after multiple remelting under a vacuum (step 50 a ) and forging in the β-range (temperatures of above 960° C.) (step 51 a ), the first zirconium alloy ZrNb of the matrix is quenched (step 52 ), a first tube blank Rc being produced from the matrix material, without the β-quenching (step 52 a ) being followed by thermal treatment with an appreciable parameter value A. A step of this kind is provided only for the second zirconium alloy of the protective layer, in which multiple remelting in a vacuum (step 50 b ) and forging in the β-range (step 51 b ) and annealing at temperatures of below about 600° C., in particular below 580° C. (α-range), take place. In this case, the second tube blank Rd is produced, which is inserted exactly into the interior of the first tube blank Rc. For the first tube blank Rc produced in steps 51 a and 52 a , virtually the parameter value A=0 is obtained, while, in steps 51 b , 52 b and 53 , the second tube blank Rd can be produced with a parameter value below 2·10 −18 h. In the exemplary embodiment, A=1·10 −18 h was set in step 53 .
[0084] The two tube blanks inserted one into the other are welded to one another and extruded together, subsequently brought to the final dimensions of the cladding tube (step 55 ) in a plurality of pilgrim steps, with recovery annealings interposed between them, and subjected to terminal annealing 56 . In steps 54 to 56 , A lower than 0.5·10 −18 h is maintained, even values A lower than 0.1·10 −18 h being possible (here: A=0.9·10 −18 h).
[0085] According to the value A being lower than 0.5·10 −18 (preferably, A lower than 0.2·10 −18 , at all events at least lower than 0.3·10 −18 ) for steps 50 a to 52 a , in the finished cladding tube preferably a value A lower than 0.1·10 −18 h is obtained for the first zirconium alloy of the matrix 41 , whereas a value A=0.1 to 3·10 −18 h, preferably between 0.2 and 1.5·10 −18 h, is obtained for the second zirconium alloy.
[0086] The cladding tubes produced in this way are filled with the columns of relatively highly enriched fuel pellets and with the high-pressure gas, are closed in a gastight manner by the end plugs and are inserted into the skeleton mentioned. They have a high burn-up which makes it possible to have a long period of utilization in the pressurized water reactor. When the pressurized water reactor is in operation, in the control of the power output the permissible rates of change need to be coordinated essentially only with the time constants defined by the physics of the fuel and of the reactor, only minor account needing to be taken of possible material damage which, even after lengthy operating times under part load, could occur on the cladding tubes when the reactor power output is being run up.
TABLE 1 Zry2 Zyr4 Sponge Grades Grades Zr/Nb Grade R60802 R60804 Grade Element R60001 R60812 R60814 R60901 Composition, Weight % Tin . . . 1.20-170 1.20-170 . . . Iron . . . 0.07-0.20 0.18-0.24 . . . Chromium . . . 0.05-0.15 0.07-0.13 . . . Nickel . . . 0.03-0.08 . . . . . . Niobium . . . . . . . . . 2.40-2.80 Oxygen {circumflex over ( )} {circumflex over ( )} {circumflex over ( )} 0.09-0.13 Iron + chromium + nickel . . . 0.18-0.38 . . . . . . Iron + chromium . . . . . . 0.28-0.37 . . . Maximum Impurities, Weight % Aluminum 0.0075 0.0075 0.0075 0.0075 Boron 0.00005 0.00005 0.00005 0.00005 Cadmium 0.00005 0.00005 0.00005 0.00005 Carbon 0.027 0.027 0.027 0.027 Chromium 0.020 . . . . . . 0.020 Cobalt 0.0020 0.0020 0.0020 0.0020 Copper 0.0050 0.0050 0.0050 0.0050 Hafnium 0.010 0.010 0.010 0.010 Hydrogen 0.0025 0.0025 0.0025 0.0025 Iron 0.150 . . . . . . 0.150 Magnesium 0.0020 0.0020 0.0020 0.0020 Manganese 0.0050 0.0050 0.0050 0.0050 Molybdenum 0.0050 0.0050 0.0050 0.0050 Nickel 0.0070 . . . 0.0070 0.0070 Nitrogen 0.0080 0.0080 0.0080 0.0080 Silicon 0.0120 0.0120 0.0120 0.0120 Tin 0.0050 . . . . . . 0.0050 Tungsten 0.010 0.010 0.010 0.010 Uranium (total) 0.00035 0.00035 0.00035 0.00035 {circumflex over ( )} When so specified in the purchase order, oxygen shall be determined and reported. Maximum or minimum permissible values, or both, shall be as specified in the purchase order.
[0087]
TABLE 2
I
II
Min.
Max.
Min.
Max.
Sn
1.0 (1.2)%
1.8 (1.5)%
. . .
1.2 (0.005)
Fe
0.2 (0.24)%
0.6 (0.5/0.4)
. . .
1.2 (0.15)
Cr
(0.8/0.10/0.12)
0.3 (0.25/0.20)
. . .
0.3 (0.02)
Nb
. . .
. . .
0.8
2.8 (1.3)
Remainder: “Zr sponge” with:
O
(0.10/0.12)
(0.20/0.18/0.16)
(0.10/0.12)
(0.20/0.18/0.16)
C
. . .
(0.01)
. . .
(0.02)
N
. . .
(0.005)
. . .
(0.005)
Si
(0.005/0.007)
(0.012)
. . .
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FIELD OF THE INVENTION
The following invention relates generally to an apparatus used in the preparation of food stuffs. More specifically, the instant invention is directed to the comminution and liquefaction of comestibles rendering the food stuffs from a solid form to either a liquid or viscous form.
BACKGROUND OF THE INVENTION
The instant invention chronicles further evolution over applicant's U.S. Pat. Nos. 2,864,419 to Woock and 3,976,001 to Trovinger. While each of these patents chronicles the state of the art at the time of those inventions, ongoing research and consumer feedback have led to the subject of the instant invention.
The following prior art reflects the state of the art of which applicant is aware and is included herewith to discharge applicant's acknowledged duty to disclose relevant prior art. It is stipulated, however, that none of these references teach singly nor render obvious when considered in any conceivable combination the nexus of the instant invention as disclosed in greater detail hereinafter and as particularly claimed.
______________________________________U.S. PAT. NO. ISSUE DATE INVENTOR______________________________________2,864,419 December 16, 1958 Woock3,976,001 August 24, 1976 Trovinger______________________________________
SUMMARY OF THE INVENTION
One facet of applicant's contribution over the known prior art involves the utilization of more advanced technology with respect to components which are selectively removable from the juicer apparatus. Heretofore the machine could not be disabled if a critical part were to have been omitted.
For example, when one is juicing, a feeder throat communicating with a juicer body would admit food stuffs to a cutter which would then coact with the food stuffs and either liquefy them or discharge them through an end of the juicer housing as a paste. More specifically, the juicer body is intended to include a sliding screen holder at a bottom area of the juicer body opposite from the top mounted feeding throat. When the holder supports a screen below the cutter, liquid would be dispensed through the screen and into an underlying container. Pulp would be discharged through a discharge end of the juicer body.
On the other hand, should it be desired that the food stuff be rendered into a paste-like form, it is not desirable to separate the juice or oil from the pulp, but rather it is desirable to keep them commingled. In such event, the screen will have been replaced with a plate that blocks the access normally existing through the screen. Thus, the entire food product is discharged through the discharge end of the juicer body. Nut butters can be made this way.
Until now, there was no practical way to disable the machine should the screen holder not be installed on a bottom face of the juicer body. The effect of its omission is that access to the cutter can be afforded where the screen holder would normally be. This, by itself, is not objectionable, but should the user also neglect to put a container for catching the liquid that is generated by the action of the cutter, when the machine is operated, liquid will spill onto a counter surface.
Just having the liquid disposed on a counter surface is a relatively minor annoyance. However, human nature induces a reflexive action in which the user of the machine may attempt to minimize the amount of spillage. The user therefore may reflexively put one's hand adjacent where the screen holder would normally be to "catch" the spill. A possibility therefore exists that one's hand could get too close to the cutter. This is because the screen holder and the clearance that it affords, as well as the barrier through the screen, has not been provided.
The instant invention disables the machine without the screen holder in place.
More particularly, the screen holder carries a magnet on a surface thereof proximate to a bell hub which serves as a cap adjacent one end of a motor which has an output shaft that projects towards the cutter. The bell hub supports a triac and reed switch device which is sensitive to the presence of the magnet and is interposed in the circuit which normally powers the motor. Thus the motor is enabled only when it senses the presence of the magnet and therefore the screen holder. Tolerances are such that the magnet switch system is not easily defeated.
OBJECTS OF THE INVENTION
Accordingly, it is a primary object of the present invention to provide a new and novel juicer.
A further object of the present invention is to provide a device as characterized above which is extremely durable in construction, safe to use and lends itself to mass production techniques.
A further object of the present invention is to provide a device as characterized above in which the motor that powers an output shaft of the juicer which carries the cutter cannot be enabled if a sliding screen holder is missing from the device.
Viewed from a first vantage point, an object of the present invention is to provide a safety device for a power juicer, comprising, in combination: a motor having an output shaft disposed within a housing with an end of the shaft projecting from the housing, the shaft end receiving a cutter for rotation with the shaft, the cutter surrounded by a juicer body which includes a feeding throat, a discharge and a juice outlet, a removable holder extending the juice outlet from the cutter, and means for enabling the motor carried on the holder to prevent motor operation without the holder deployed on the juicer.
Viewed from a second vantage point, an object of the present invention is to provide a safety circuit for a power juicer, comprising, in combination: a power source, a motor disposed in a housing and having a cutter in driving engagement therewith, an on-off switch operatively coupled between the motor and power source, a cutter limited access means coupled to the housing and a safety switch located on the cutter limited access means operatively coupled to the motor to render the motor operative only when the cutter limited access means is deployed on the housing.
These and other objects will be made manifest when considering the following detailed specification when taken in conjunction with the appended drawing figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of the juicer with portions taken in section for clarity.
FIG. 2 is an exploded parts perspective view of the sections shown in FIG. 1.
FIG. 3 is a similar perspective view of FIG. 2 taken from a different angle.
FIG. 4 is a schematic depiction of the safety device according to the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Considering the drawings, wherein like reference numerals denote like parts throughout the various drawing figures, reference numeral 10 is directed to the juicer according to the present invention.
Referring to FIGS. 1 and 4, in its essence, the juicer 10 includes a motor 2 ensconced within a housing 4 having an output or motor shaft 30 which supports a cutter 28. An end of the motor adjacent the cutter 28 includes a shield 8 which underlies a hub 6 which collectively isolate the interior of the housing 4 from external contamination. The housing 4 includes a base 34 supported on a surface via feet 32.
The output shaft 30 driven by the motor 2 extends from the motor 2, through both the motor and shield 8 end the juicer end bell hub 6 to receive a cutter 28 thereon. The cutter 28 is circumscribed by a juicer body 22. The juicer body 22 includes on a topmost surface thereof, a top mounted inlet feed throat 20 which receives food stuffs therethrough for admission to the cutter 28 for liquefaction and/or comminution. A tamper 24 assists in forcing the food stuffs to the cutter 28.
The body 22 includes an outlet 40 on a bottom side thereof remote from the throat 20. The outlet 40 is protected by either a screen 16 or a non-foraminous plate 16 which blocks this outlet 40 and is held in place by a sliding holder 18. The juicer body 22 includes a discharge end 26 remote from the bell hub 6.
When the screen 16 is in place, liquid will pass through outlet 40 and pulp will exit the discharge end 26. When the screen 16 is replaced with the plate, the food stuffs placed within the throat 20 will come through the discharge end as a paste.
The screen holder 18 has an end 42 adjacent the bell hub 6. That holder end 42 supports a magnet 14. An inside surface of the juicer bell hub 6 supports a triac 12 having quick connect terminals 72. The quick connect terminals 72 of the triac 12 are operatively coupled to the motor 2 and a source of power (FIG. 4) with the source of power interrupted therefrom by a manual switch S and an A/C plug P coupled to power. When the manual switch S is enabled, a voltage will appear across two terminals of the triac 12 operatively coupled between the power and the motor 2. However, current will not flow through the triac 12 until magnetic starter switch or reed switch 50, disposed in parallel with the triac 12, perceives the magnet 18 to be adjacent thereto. Only the magnet 14, when strategically placed adjacent the reed switch 50, will enable the circuit of FIG. 4. The closing of the reed switch 50 included by the magnet 18 allows the voltage to activate the triac 12 which then transmits power directly to the motor in a safe manner.
The magnet 14, as shown in FIG. 3, is mounted on a face 42 of the sliding screen holder 18 so that it properly addresses the reed switch 50. The sliding screen holder 18 is a substantially four-sided structure having an open top face and open bottom face. The open bottom face can include access inhibiting bars 41, preferably running transverse to the holder's long axis to further preclude access therein. The bars 41 are cylindrical with a flat bottom. The topmost portion of the sliding screen holder includes first and second trackways 60, 62 running parallel to the length of the holder 18. The trackways 60, 62 ride within tracks 66 (FIG. 1) located on both sides of the outlet 40 on the juicer body 22. Motion of the holder 18 in the direction of the arrow A slides the holder 18 onto the juicer body 22 and locates the magnet 14 adjacent the reed switch 50. A shelf 68 disposed below the trackways 60, 62 supports either the screen or plate 16.
FIG. 3 also shows an interior face of the bell hub 6 and the means by which the triac 12 is mounted on the interior face of the bell hub 6. FIG. 2 shows another view of the plate 70 and reflects that the one side of the plate 70 adjacent the bell hub supports the magnetic starter switch, preferably reed switch 50. The FIG. 3 view, showing the triac mounted on an opposite side of the plate 70 includes a pair of leads 72 for coupling into the circuit described above and shown in FIG. 4. The triac 12 is located on the plate 70. Locator posts 74 on an inner face of hub 6 position the triac and magnetic reed 50 precisely to address the magnet 14 carried on the holder 18.
Moreover, having thus described the invention, it should be apparent that numerous structural modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described hereinbelow by the claims. | 4y
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FIELD OF THE INVENTION
This invention relates to wear resistant nuclear fuel assembly components and, more particularly, to surface hardened, zirconium-based alloy components such as nuclear fuel cladding tubes, spacer elements and channels and to methods of making such components.
BACKGROUND OF THE INVENTION
The operating environment within a nuclear reactor, including a pressurized water reactor (PWR) and a boiling water reactor (BWR) is particularly hostile. A considerable effort has been expended in the nuclear reactor industry to arrive at materials which are able to withstand the combination of mechanical, thermal, chemical (corrosion) and radiation effects encountered in that environment. At the present time, only a few types of zirconium-based alloys are considered to be acceptable. Those alloys are generally identified as Zircaloy materials. The Zircaloy materials are used for nuclear fuel cladding tubes, spacer elements and channels within the reactor.
As a result of experience with long term operation and multiple reloads of nuclear fuel elements, it has been found that certain operating conditions arise which tend to reduce the energy output per unit of fuel ("burn-up") obtainable and thereby affect operating costs and efficiencies in an undesirable manner. For example, during the operation of nuclear reactors, metal debris which may be present in the reactor can be carried by the cooling water and can impact upon fuel assembly components. The repeated interaction of such debris and the fuel assembly components (such as fuel cladding tubes, channels or spacer elements) can result in fretting (rubbing) damage to the components.
While the Zircaloy materials gradually have been optimized with respect to corrosion resistance requirements within a reactor, the fretting wear resistance of Zircaloy, as well as resistance to combined effects of fretting wear and subsequent corrosion have not been optimized. The need to improve fretting wear resistance should not result in any undesirable compromise with respect to corrosion resistance.
Zircaloy materials until relatively recently have been treated prior to insertion into a reactor by autoclaving techniques to apply a relatively thin coating (0.5 microns) of oxide material to improve their general operational characteristics. Such an oxide coating has not been found to be resistant to fretting wear or fretting induced corrosion but rather has been found to be subject to being damaged or worn away by the fretting action of the debris. Thereafter, fretting corrosion will occur at the fretting site in the area where the oxide layer has been removed. The corrosion layer which forms is also susceptible to debris fretting wear and will be removed by action of the water and debris. Eventually, after successive cycles of wear and corrosion occur, a hole ultimately can be produced in the base metal itself. In the case of fuel cladding, such a hole will result in the unwanted release of radioactive material and radiation into the cooling water, and if it is in excess of reactor operating limits, will require an untimely shutdown of the reactor for replacement of fuel elements.
One approach to avoiding such problems is to improve the wear resistance of the Zircaloy fuel assembly components, especially at their lowermost ends where debris is most often present.
Outside of the field of nuclear reactors, it has been proposed that layered structures incorporating whiskers of nitrides, carbides or carbonitrides into Group IVb metals, which include zirconium, will provide a hardened surface condition. (See, e.g., U.S. Pat. Nos. 4,915,734; 4,900,525; and 4,892,792.) Furthermore, dispersions of hard substances in a binder metal, such as zirconium oxide dispersed in iron, cobalt or nickel (see U.S. Pat. No. 4,728,579) have been described as providing improved wear resistance for cutting tools. In addition, in the field of cutting tools, it has been observed (see U.S. Pat. No. 3,955,038) that, before applying an oxide coating such as zirconium oxide to a binder metal, imposition of an intermediate layer such as a carbide or a nitride of a metal in the fourth to sixth subgroups of the periodic system (including zirconium) may impede undesirable diffusion of metal from the substrate into the formed oxide layer.
It is understood that the foregoing structures are formed by processes which require temperatures that are incompatible with maintaining the metallurgical state of Zircaloy components to be used in a reactor. That is, such Zircaloy components typically are heat treated to produce particular grain structures and stress relieved conditions in the finished product.
In order to preserve the desired metallurgical structure and properties, it is necessary that any additional wear resistant layer be applied utilizing temperatures that are below temperatures at which the desired properties will be changed.
For example, in the case of stress relieved cladding of a type used in pressurized water reactors, post annealing processing temperatures should be maintained below about 500° C. In the case of cladding, spacers or channels which have been treated to produce a recrystallized condition (as typically used in boiling water reactors), post annealing processing temperatures should be maintained below about 700° C. and, in some cases, below about 600° C. in order to avoid undesired metallurgical changes in the respective components.
STATEMENT OF THE INVENTION
In accordance with one aspect of the present invention, an improved nuclear fuel element of the type including a zirconium alloy tube, which may or may not be separated from a central core of nuclear fuel material by a barrier layer, has a hard, wear resistant layer produced on at least a portion of the outside surface of the tube by reacting the outside surface of the zirconium alloy with material selected from the group consisting of carbon, nitrogen, oxygen and combinations of the foregoing, the reaction occurring below about 700° C. at a temperature which is sufficiently low to avoid unwanted changes (e.g., annealing which changes desired grain structures) near the outer surface of the tube.
In accordance with a further aspect of the present invention, a method of improving fretting resistance of zirconium alloy components for use in a nuclear reactor comprises reacting at least a portion of the surface of the component with material selected from the group consisting of carbon, nitrogen, oxygen and combinations of such materials, the reaction temperature being maintained below about 700° C. at a level to produce a hard, wear resistant layer on the surface without producing undesirable metallurgical changes in the vicinity of the surface.
In accordance with yet another aspect of the present invention, an improved structural component formed of a zirconium alloy for use in a nuclear reactor, the improvement comprising a wear resistant layer produced on at least a portion of a surface of the component which contacts cooling fluid in the reactor, the wear resistant layer being produced by reacting the surface with material selected from the group consisting of oxygen, carbon, nitrogen and combinations of such material, the reaction temperature being maintained below about 700° C. so as to maintain a metallurgical state in the vicinity of the surface which existed prior to the formation of the layer.
BRIEF DESCRIPTION OF THE DRAWING
The foregoing and other features of the present invention will be more readily apparent from the following detailed description and drawings of illustrative embodiments of the invention in which:
FIG. 1 is an elevation view, partially in section, of a typical fuel assembly for a light water nuclear power reactor, the assembly being foreshortened in height and partially broken away for convenience and clarity; and
FIG. 2, drawn to a different scale than FIG. 1, is a sectional view of a fuel rod employed in the assembly of FIG. 1 incorporating one version of the present invention.
DETAILED DESCRIPTION
Referring to FIG. 1, a typical 14×14 fuel bundle assembly is indicated generally by the reference numeral 10. Fuel assembly 10 includes an upper tie plate 12 and a lower tie plate 14, capturing at opposite ends a plurality of (e.g., 176) fuel rods 13 of tubular shape. A plurality of guide tubes 11 are secured to upper tie plate 12 and to lower tie plate 14. A plurality of grid spacers 15 (e.g., eight several of which are shown) are disposed along the length of fuel rods 13 at locations between tie plates 12 and 14 and form cells, as is well known, through which fuel rods 13 and guide tubes 11 extend. A lowermost one 15' of the grid spacers is illustrated as a debris-resistant spacer of the type shown and described in U.S. Patent No. 4,849,161 of Brown et al.
Each of fuel rods 13 encloses a stack of fissionable fuel pellets 16. Pellets 16 in each stack are maintained in close proximity to each other by means of a spring 17 disposed between an upper end of the rod 13 and the uppermost one of pellets 16. A lower end cap 18 of each fuel rod is in close proximity to but spaced away from the upper portion of lower tie plate 14 to take into account the expected linear growth of rods 13 in the operation of the reactor. The total height from the bottom of lower tie plate 14 to the top of the uppermost pellet 16 (i.e., the top of the active fuel) may, for example, be a few inches less than twelve feet.
Lower tie plate 14 may be entirely conventional or may comprise a debris resistant design above the lower core support plate 22.
Coolant supplied from below the lower tie plate 14 may be expected to carry debris of the type noted above. As the coolant (water) flows upwardly, some debris will be intercepted and can drop down below the plate 22. Some amount of debris, however, can impact upon the exterior surface of fuel rods 13, spacers 15 and, in the case of BWR assemblies, enclosing channel structure, particularly at the lower ends thereof. In the case where a fuel assembly does not include a debris catching device or screen, an even greater amount of debris may be expected to impact upon the exterior surface of fuel rods 13, spacers 15 and other components in the fuel assembly.
Fuel rod cladding, spacers or channels may be manufactured in accordance with the present invention to include a method for final hardening treatment of the surface(s) of the components which are exposed to coolant water and accompanying debris.
A process in accordance with this invention, which is applicable to treating either one or more surfaces of zirconium alloy material, whether it is in strip, sheet or tubular form, will produce components having an extended service life. It is preferable, in order to retain the desired metallurgical condition of the component, that hardening operations be conducted without exceeding a temperature of, for example, 500°-700° C., the specific limit temperature being dependent upon the function and/or nature of the component and the environment (PWR or BWR) in which the component is to be employed as noted above.
In accordance with the one aspect of the present invention, a method of improving fretting resistance of zirconium alloy components used in nuclear reactors comprises placing the alloy component into a closed vessel, introducing a gaseous atmosphere containing acetylene and raising the temperature within the vessel to a temperature in the range of 450° C. to 500° C., preferably to 475° C .for a period of 8 hours so as to produce a hard, wear resistant carbide layer on the surface of the alloy component. The carbide layer will be of the order of one micron thick (typically slightly less), and will exhibit a hardness acceptable for resisting fretting in a nuclear reactor environment. The carbide layer which is produced in this manner is black in color.
Cladding and flat Zircaloy material treated with acetylene as described above to produce a wear resistant layer thereafter was subjected to a standard autoclaving test to determine whether the wear resistant layer was also resistant to waterside corrosion. The results of testing for corrosion resistance alone were that such corrosion resistance was equal to or better than that obtained for components which were the same in all respects except that they were not provided with the wear resistant layer.
In accordance with a further aspect of the invention, a method of improving fretting resistance of zirconium alloy components used in nuclear reactors comprises placing at least a portion of an alloy component to be treated in a molten bath containing one or more cyanide salts having an effective melting point less than 500° C. for a period of four to twelve hours to produce a wear resistant layer on the alloy component. In one particular arrangement, a mixture of 60% sodium cyanide and 40% potassium cyanide (weight percent) was used to produce a hard, wear resistant layer two microns thick which was black in color. X-ray fluorescence analysis of the layer so formed indicated the presence of oxide material, although it is normally to be expected that a carbonitride layer is formed by means of a cyanide bath. The resulting surface layer was found to be of increased hardness and wear resistance as compared to the Zircaloy itself.
In accordance with a further aspect of the invention, a method of improving fretting resistance of zirconium alloy components used in nuclear reactors comprises placing at least a portion of an alloy component to be treated in a molten bath containing one or more carbonate salts having an effective melting point less than 500° C. for a period of four to twelve hours to produce a wear resistant oxide layer on the alloy component. In one particular arrangement, a mixture of 50% lithium carbonate and 50% potassium carbonate (weight percent) was used to produce a hard, wear resistant layer two microns thick which was black in color. X-ray fluorescence analysis of the layer so formed indicated the presence of oxide material. The resulting surface layer was found to be of increased hardness and wear resistance as compared to the Zircaloy itself.
In accordance with a further aspect of the present invention, a method of improving fretting resistance of zirconium alloy components used in nuclear reactors comprises lacing the zirconium alloy component in a closed furnace, introducing an air or oxygen atmosphere into the furnace, and raising the temperature within the furnace to a temperature level between about 400° C. and 500° C. (preferably less than 475° C.) for a period of between about forty and about eighty hours to grow a hard, wear resistant oxide layer on the surface of the alloy component. The oxide layer so formed typically will be in the range of between about 0.7 microns and 1.4 microns thick (that is, of the order of one micron) and will e black in color.
The grown oxide layer exhibits a desired resistance to corrosion which might occur in a nuclear reactor environment while, at the same tie, providing an increased fretting resistance.
In each of the foregoing examples, the wear resistant layer was produced without compromising the corrosion resistance characteristics of the zirconium alloy component. Particular attention must be paid to the maximum reaction temperature in each case to avoid undesirably changing the metallurgical structure of the components. To that end, temperatures less than about 500° C. were employed in each example for cladding in the stress relieved condition. Appropriate reaction temperatures (e.g., temperatures in the vicinity of about 600° C. to 700° C.) for components other than stress relieved cladding, such as recrystallized cladding, channel and spacers, similarly should be observed to avoid undesired secondary effects on metallurgical characteristics such as grain size or structure.
As is shown in FIG. 2, typical fuel cladding 13 constructed in accordance with the present invention includes an outer wear resistant layer 30 over at least a portion of the length thereof (typically at least the lowermost portion). The thickness of layer 30 is exaggerated in FIG. 2 compared to the dimensions of other elements. The inner surface of cladding 13 may be separated from fuel pellets 16 by a barrier layer 32 (as is known). The invention is also useful in connection with non-barrier cladding, spacers and channels as noted above.
It should be recognized that various modifications may be made in the apparatus and processes described above without departing from the true scope of the present invention, which is pointed out in the following claims. | 4y
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FIELD OF THE INVENTION
The present invention relates to a valve system for treating hydrocephalus.
BACKGROUND
Shunt systems for directing body fluid from one region to another are known in the medical field. One application for such a fluid shunt system is in the treatment of hydrocephalus in order to direct cerebrospinal fluid (“CSF”) away from the brain and into the venous system or to another region of the body. In this application, a shunt is implanted on the patient's skull, under the scalp, and is coupled to a brain ventricle catheter which is adapted for insertion into the brain and to a distal catheter which is adapted for insertion into the drainage region, such as the peritoneal cavity, the atrium or other drainage site.
The shunt systems typically include a pressure-regulated valve to control the flow rate of the CSF. The distal catheter is typically implanted caudal to the ventricular inlet which causes the shunt system to act as a siphon when the patent is in the upright position. The siphoning effect can cause overdrainage that can lead to low pressure headaches, slit ventricles, and subarachnoid hemorrhages.
Anti-siphoning has previously been addressed with several mechanisms, including weighted ball and seat valves, flow control valves, and diaphragm valves. In turn, the weighted ball and seat valves contain one or more balls or other mechanism, that when acted on by gravity, i.e. when the patient is upright, the ball seats in the valve passage and closes the fluid pathway. Closing a primary fluid pathway can lead to underdrainage if the alternate pathway does not provide sufficient drainage as well. Another ball and seat design closes in response to excessive flow, but offers a secondary pathway that always remains open, allowing for constant drainage, but the resistance of the secondary pathway remains fixed. Diaphragm valves are typically in the closed flow position and only opening in response to positive pressure and closing again when under negative distal pressure. A diaphragm valve has its disadvantages, in that it can become encapsulated by tissue and fails to open under positive pressure, this leads to underdrainage.
Examples of previous solutions include U.S. Pat. No. 4,605,395 to Rose et al. disclosing a single flow path ball and seat valve and U.S. Pat. No. 4,681,559 to Hooven, having two flow paths, but both have pressure valves. U.S. Pat. No. 6,126,628 Nissels is a pressure valve with a tortuous secondary flow path. However, the secondary flow path has fixed flow characteristics. Additionally, U.S. Pat. No. 8,177,737 to Negre et al. is a pressure valve with numerous secondary ports, but the flow to certain ports is controlled by the location of the ball in the primary flow path. Thus, the need exists for an anti-siphon valve of simple design, yet having multiple flow and pressure characteristics.
SUMMARY
Accordingly, the present invention provides tools and methods for simply controlling the siphoning effect caused by the implantation of certain shunt-systems. The examples of the present invention provide gravitationally assisted anti-siphoning valves wherein control over the siphoning rate is directly related to the number of open fluid passageways. Each secondary pathway can provide equal fluid flow resistance, such that each setting of the device is a multiple of the resistance of the single pathway. Alternately, each pathway can have its own unique resistance profile and flow is controlled by selecting the appropriate pathway. In one example, the user can select one or more pathway configurations to control the flow, without complex mechanisms that can potentially be obscured by tissue.
An anti-siphon drainage device can have a housing forming an internal chamber, inlet and outlet ports can be part of the internal chamber and fluidly connected by a primary flow path. A valve seat is associated with the primary flow path, a sloped section extends from the valve seat, and a valve element is disposed in the sloped section and can seat in the valve seat to restrict a fluid flow into the primary flow path from the inlet port. A secondary flow path can have an opening near the inlet port and an orifice near the outlet port. A regulator has an aperture to selectively open and close the opening of the secondary flow path. When the valve element is seated in the valve seat and restricting the fluid flow into the primary flow path, the fluid flows into the secondary flow path.
The anti-siphon drainage device can have the inlet port disposed approximately above the outlet port in a vertical direction, causing the valve element to enter the valve seat and restrict the fluid flow to the primary flow path. Contrary, when the inlet port is disposed approximately parallel the outlet port in a horizontal direction, the valve seat allows the fluid flow into the primary flow path. One of the valve element or the valve seat can allow a restricted fluid flow into the primary flow path when seated (i.e. a “leaky valve”). The disposition of the valve element in the valve seat can be controlled by gravity.
The primary flow path can be hydraulically larger than the secondary flow path. Some examples have the secondary flow path spiraled around the primary flow path. In others, they can be any shape or straight.
Another example of the anti-siphon drainage device can have a second secondary flow path separate from the secondary flow path having a second opening. The secondary flow path and the second secondary flow path can spiral around the primary flow path as a double threaded screw. The regulator can include a plurality of second apertures, which along with the aperture, are configured to selectively open and close the opening and the second opening.
A yet further example can also have a third secondary flow path separate from both the secondary flow path and the second secondary flow path, and having a third opening. The regulator now has a plurality of second apertures, which along with the aperture, are configured to selectively open and close the opening, the second opening, and the third opening. The regulator can have different settings to selectively open and close the opening, the second opening, and the third opening. The settings can have at least one of the following configurations: all open, all closed, each of the openings individually opened, and pairs of openings opened.
Furthermore, an example can have the primary flow path having a primary hydraulic capacity (P1), the secondary flow path having a secondary hydraulic capacity (F1), the second secondary flow path having a third hydraulic capacity (F2), and the third secondary flow path having a fourth hydraulic capacity (F3). The hydraulic relationship between them can be: F1<F2<F3<P1. Alternately, the hydraulic relationship can be: F1<F2<F1+F2<F3<F1+F3<F2+F3<F1+F2+F3<P1.
A method of forming an anti-siphon drainage device like that described above can include the steps of forming the primary flow path with the valve seat; disposing the valve element in the sloped section; forming the secondary flow path; and disposing the regulator over the secondary flow path to selectively occlude the secondary flow path. Forming the secondary flow path can include spiraling the secondary flow path around the primary flow path. The primary flow path can be formed with a first hydraulic characteristic, and the secondary flow path can be formed with a second hydraulic characteristic. In an example, the first hydraulic characteristic is greater than the second hydraulic characteristic.
BRIEF DESCRIPTION OF THE DRAWINGS
This invention is described with particularity in the appended claims. The above and further aspects of this invention may be better understood by referring to the following description in conjunction with the accompanying drawings, in which like numerals indicate like structural elements and features in various figures. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
The drawing figures depict one or more implementations in accord with the present teachings, by way of example only, not by way of limitation. In the figures, like reference numerals refer to the same or similar elements.
FIG. 1 illustrates an example of the placement of an anti-siphon device of the invention relative to a fluid shunt system disposed in a patient;
FIG. 2 is an isometric view of an example of anti-siphon device in accordance with the invention;
FIG. 3 is a front view of the anti-siphon device without the housing in the secondary flow position;
FIG. 4 is a front view of the anti-siphon device without the housing in the primary flow position;
FIGS. 5A and 5B are a top section view of the anti-siphon device illustrating an example of a regulator;
FIG. 6 is a cross-sectional isometric view of another example of an anti-siphon device;
FIGS. 7A and 7B are a top section view of the anti-siphon device illustrating another example of a regulator; and
FIG. 8 is a table illustrating the apertures, secondary flow paths, and the flow resistance level.
DETAILED DESCRIPTION
In the following detailed description, numerous specific details are set forth by way of examples in order to provide a thorough understanding of the relevant teachings. However, it should be apparent to those skilled in the art that the present teachings may be practiced without such details. In other instances, well known methods, procedures, components, and/or circuitry have been described at a relatively high-level, without detail, in order to avoid unnecessarily obscuring aspects of the present teachings.
Referring to the drawings, and particularly to FIGS. 1 and 2 , a CSF anti-siphon pressure relief valve system 100 for maintaining a desired predetermined intracranial pressure in a patient P is illustrated. The system 100 includes an adjustable resistance, gravitationally activated, anti-siphon device 102 constructed in accordance with the present invention for maintaining a desired intracranial pressure.
Cerebrospinal fluid (CSF) 14 is drained from a ventricle 15 of the brain 16 by means of a ventricular catheter 17 . Preferably, the catheter is radio-opaque in order to facilitate its accurate placement within the brain. The distal end 18 of the catheter allows the passage of CSF therethrough and is positioned in a suitable brain ventricle. The other end of the catheter is coupled to an inlet port 104 of the anti-siphon device 102 to establish fluid communication between the system 100 and the ventricle. The outlet port 106 of the valve system is attached to one end of a drain catheter 23 , the opposite end of which discharges into an appropriate location in the patient's body. Although the drain catheter is shown threaded through an appropriate vein 24 to terminate within the right atrium of the heart 25 , a different drainage location, such as, for example, the peritoneal cavity, could be selected instead. When open, the system 100 allows passage of CSF from the brain ventricle to the selected discharge location to relieve excessive intracranial pressure caused by excessive accumulation of CSF.
While an increased differential pressure may result from the excessive accumulation of CSF in the brain ventricle, such an increase might also be a perfectly normal response to ordinary physical activity of the patient. For example, when a patient stands after lying for some time in a recumbent position, as illustrated in phantom in FIG. 1 , the differential pressure will suddenly increase by reason of the sudden increase in vertical height H in the fluid column existing between the distal end of the ventricular catheter 17 and the drainage location. If a relief valve of the system were to open and permit unrestrained fluid flow in response to this pressure increase, overdrainage of the ventricle and a brain hematoma, are possible results. Further, the dimensions of the various parts described are selected so as to be compatible with subcutaneous implantation of the valve over the cranium 33 .
Referring to FIGS. 2 , 3 and 4 , an example of the adjustable resistance, gravitationally activated, anti-siphon device 102 according to the invention is shown. The device 102 includes an inlet 104 in the form of an aperture 108 disposed in a housing 110 and an outlet 106 in the form of a connector 112 suitable for coupling to a drainage catheter 23 . The housing 110 defines the inlet 104 at the proximal end of the device. The outlet 106 is at the distal end of the device 102 through which the fluid is directed from the device 102 . The components of the device 102 , including the housing 110 , are fabricated with any suitable biocompatible material. Examples of such preferred materials include polyethersulfone (PES), polysulfone (PS), polyurethane, polyethylene and polypropylene.
FIGS. 3 and 4 illustrate a partial section through the housing 110 . Through a midline 114 of the housing 110 is a primary flow path 116 . The primary flow path 116 connects the inlet port 104 to the outlet port 106 and is the main fluid path for the CSF. At a point in the primary flow path 116 a valve seat 118 is disposed in and stems from one end of the primary flow path 116 approximate to the inlet port 104 . Leading to the valve seat 118 is a sloped section 120 . The sloped section 120 can angle from the inlet port 104 to the valve seat 118 , where the narrowest section is at the valve seat 118 . Disposed within the sloped section is valve element 122 , which in one example can be a ball. Suitable materials for fabricating the ball 122 and seat 118 include synthetic ruby (aluminum oxide).
The valve element 118 , in one example, is not pressure sensitive. For example, the valve element 118 is not biased using a resilient element (e.g. a spring) to be unseated only when the pressure at the outlet 106 reaches a predefined threshold. In this example, the valve element 118 is displaced by gravity dictated by the orientation of the valve 102 .
When the housing 110 is in the upright position (i.e. the inlet port 104 is vertically higher than the outlet port 106 ) the ball 122 can be disposed in the seat 118 and the primary flow path 116 is sealed off by the ball 122 (see FIG. 3 ). In one example, the primary flow path 116 is completely sealed to fluid flow. In other examples, the seal maybe “leaky” and deliberately allow a small amount of fluid to pass into the primary flow path 116 even though the ball 122 is seated properly.
The sloped section 120 can direct the ball 122 into the valve seat 118 when the housing 110 is in the vertical position. In examples, the sloped section 120 can be conical or frustoconical. In contrast, FIG. 4 illustrates the device 102 is the horizontal position, and the ball 122 , by force of gravity, rolls down the sloped section 120 and out of the valve seat 118 . This clears the primary flow path 116 and allows fluid to flow freely. The horizontal and vertical positions of the device typically correspond to a horizontal or vertical position of the patient (i.e. laying down or sitting up).
The device 102 can also include one or more secondary flow paths 124 . The secondary flow paths 124 can transport fluid from the inlet 104 to the outlet 106 but are separate and distinct from the primary flow path 116 and in other examples are separate and distinct from each other. As an example, FIGS. 3 and 4 illustrate two secondary flow paths 124 a , 124 b as a spiral path formed from a double threaded screw. However, the secondary flow paths 124 can take any form and any number. The opening 126 for the secondary flow paths can be within the sloped section 120 but outside the valve seat 118 . In one example, the ball 122 cannot seat in, and thus block, the secondary flow paths 124 . The secondary flow paths 124 can then discharge to the outlet port 106 through an orifice 140 .
Under primary flow conditions, as illustrated in FIG. 4 , the primary flow channel 116 is open, because the ball 122 has rolled out, and the CSF preferentially flows through the primary flow path 116 . This is when the patent is typically prone. FIG. 3 illustrates the secondary flow conditions when the patent is upright and gravity has placed the ball 122 into the seat 118 , sealing off the primary flow path 116 . In this condition, the fluid now must flow into the openings 126 of the secondary flow paths 124 to reach the outlet 106 . Sealing the primary flow channel 116 prevents siphoning, while having secondary flow paths 124 continues to allow for drainage.
In an example, each of the primary and secondary flow paths can have the same, similar or different hydraulic characteristics, for example, at least flow rates. The primary flow path 116 can be hydraulically larger than the secondary flow paths 124 . “Hydraulically larger” means that the primary flow path 116 can pass more fluid (i.e. a larger flow rate) than the secondary flow paths 124 , but this can be for various reasons. One reason can be that the primary flow path 116 has a larger diameter (flow rate=velocity×area) or has a smaller hydraulic resistance (also a factor of velocity and path geometry, along with other elements). A smaller hydraulic resistance allows the fluid to flow easier. Additionally, it can be a combination of these and other elements that allow a higher flow rate through the primary flow path 116 .
While, in certain examples, the ball 122 cannot block the secondary flow paths 124 , the secondary flow paths 124 can still be regulated. FIGS. 5A and 5B illustrate a secondary flow path regulator 128 . The regulator 128 can control the flow of fluid into the secondary flow paths 124 by partially or fully blocking the openings 126 . In this example, the regulator 128 has three apertures 130 . Two of the apertures 130 are illustrated in FIG. 5A as covering over both of the openings 126 . This is the maximum secondary flow condition. Also illustrated is a third aperture 130 a offset from the other two apertures 130 . The regulator 128 can be rotated such that the third aperture 130 a is over an opening 126 . It can seen in FIG. 5B , that when the third aperture 130 a is over one opening 126 , for flow path 124 a , the other opening 126 , and thus flow path 124 b , is occluded. One or either flow path 124 a , 124 b can be selected by rotation of the regulator 128 . Further, in certain examples, there can be partial occlusion.
Additionally, the regulator 128 can have a valve element opening 132 , allowing the valve element 122 unrestricted access to the valve seat 118 . In an example, the regulator 128 cannot affect or block flow to the primary flow path 116 . The purpose of the regulator 128 , in one example, is only to regulate the flow to the secondary flow paths 124 .
In certain examples, the regulator 128 is set by the surgeon prior to implanting the valve 102 into the patient. Particular rotations of the regulator 128 can result in differing secondary flow path rates and thus affect the intracranial pressure. Some valves can only be set by manual manipulation, which can require exposing the valve if the settings need to be changed once inside the patient. Other examples of the valve can have their settings changed without surgery.
Preventing flow into the primary flow path 116 when the valve 102 is upright prevents the siphoning effect. However, CSF still needs to be drained to prevent underdrainage. The secondary flow path 124 allows for continued drainage without a siphon effect. When the primary flow path 116 is opened (i.e. the valve element 122 is not seated in the valve seat 118 ) all or most of the fluid enters the primary flow path 116 . While the secondary flow path 124 is still open, the hydraulic characteristics of the primary flow path 116 are such that the fluid preferentially takes the primary path, as the path of least resistance.
FIGS. 6-7B illustrate another example of an adjustable resistance, gravitationally activated, anti-siphon device 200 . The anti-siphon device 200 can have three secondary flow paths 224 a - c . Similar elements to the above example will be similarly referenced herein. The anti-siphon device 200 has an inlet 204 in aperture 208 form disposed in a housing 210 and an outlet 206 within a connector 212 . Through a midline 214 of the housing 210 is a primary flow path 216 . The primary flow path 216 connects the inlet port 204 to the outlet port 206 and is the main fluid path for the CSF. The primary flow path 216 can have a valve seat 218 disposed therein. Leading to the valve seat 218 is a sloped section 220 that can angle from the inlet port 204 to the valve seat 218 , where the narrowest section is at the valve seat 218 . Within the sloped section 220 can be a valve element 222 , which in one example can be a ball.
When the housing 210 is upright position the ball 222 can be disposed in the seat 218 and the primary flow path 216 is sealed. FIG. 6 also illustrates a cross-section of two of the three secondary flow paths 224 a , 224 b , 224 c . In this example, the secondary flow paths 224 a , 224 b , 224 c are straight and have openings 226 a , 226 b , 226 c near the inlet 204 and flow into the primary flow path 216 at a point below the valve seat 218 through orifices 240 a , 240 b , 240 c.
FIG. 7A illustrates the openings 226 a , 226 b , 226 c of the three secondary flow paths 224 a , 224 b , 224 c . In this example, each flow path has a different flow characteristic. The first secondary flow path 224 a (“F1”) has the lowest flow rate, based on any of the factors mentioned above. The second secondary flow path 224 b (“F2”) has the next lowest flow rate, but greater than F1. The third secondary flow path 224 c (“F3”) has the largest flow rate of the secondary flow paths 224 , but still a lower flow rate than the primary flow path 216 (“P1”). In relationship form: F1<F2<F3<P1
FIG. 7B illustrates a secondary flow path regulator 228 to control the flow of fluid into the secondary flow paths 224 by partially or fully blocking the openings 226 . In this example, the regulator 228 has five to seven apertures 230 . The apertures 230 are spaced to allow any combination of secondary flow paths 224 to be set. Each individual secondary flow path 224 a , 224 b , 224 c can be selected as well as combinations of secondary flow paths 224 a , 224 b , 224 c . FIG. 8 illustrates an example of the eight different configurations three secondary flow paths of varying flow resistance can supply. The dark sections represent the apertures 230 . In this example the hydraulic capacity can be:
F 1< F 2< F 1+ F 2< F 3< F 1+ F 3< F 2+ F 3< F 1+ F 2+ F 3< P 1
In both hydraulic capacity examples F1 can have a value that 0<F1.
A user selected flow configuration can reduce the number of anti-siphon devices kept in stock. Currently, the devices are preset from the factory with a particular secondary flow rate, and thus the above example of the present invention can replace up to eight prior art devices. Here, the user can preset the secondary flow rate on the current invention and then change his mind, and change the settings again and again.
A further example is a method to form the anti-siphon valve discussed above. The method can include forming the primary flow path with the valve seat and disposing the valve element in the sloped section. Next, the secondary flow path can be formed and the regulator can be disposed over the secondary flow path to selectively occlude the secondary flow path.
While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings. | 4y
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BACKGROUND OF THE INVENTION
This invention relates to lamps and, in particular, to a lamp and socket assembly providing repeatable mechanical alignment of the lamp and reliable electrical contact with the lamp.
In the past, a number of lamps used as signal lamps, e.g. for automobiles, comprised a brass base having pins for securing the base to the socket. As known in the art, the lamp can move slightly in its socket, making repeatable positioning of the filament difficult and allowing the lamp to change position due to vibration or shock. In addition, since the base is not sealed from dirt and moisture, the base may corrode and fuse to the socket causing poor electrical contact in service and breakage when the lamp is removed.
While "prefocused" lamps are available, in which the base contains a flange for mounting the lamp and from which the filament is accurately located, it is also desirable to reduce the number of types of bases. For example, it is desirable to have a single base and socket assembly which can be used for either front or rear insertion and which has the "prefocused" characteristic.
Prior attempts to solve these problems, for example, as described in U.S. Pat. Nos. 3,749,960 and 3,999,095, have not proven entirely satisfactory. In the former, the base of the lamp is mechanically secured to the panel or reflector by a locking ring or gasket while a connector attaches to the base of the lamp and electrically connects with pins protruding therefrom. Thus, replacement of the lamp is difficult due to the gasket. The separate gasket also adds to the parts count and cost. Further, the lamp and base are physically long which may be undesirable, e.g., in the trunk of a car.
The latter patent describes a lamp and socket having a shorter overall length. However, the lamp is mechanically connected to the electrical connector which, in turn, is mechanically connected to a panel or reflector by way of a resilient gasket. This indirect mechanical connection of the lamp to the reference (panel or reflector) particularly when combined with the resilient gasket can lead to errors in the positioning of the bulb. A partial solution is to manufacture the rigid parts to very tight tolerances so that cumulative errors do not exceed a predetermined tolerance. Even if this were done, the gasket remains a source of positioning error.
SUMMARY OF THE INVENTION
In view of the foregoing, it is therefore an object of the present invention to provide a lamp and socket assembly having more consistent positioning of the filament with respect to a reference feature.
Another object of the present invention is to provide a simplified lamp and socket construction.
A further object of the present invention is to provide a moisture and dust resistant seal for the lamp connectors when assembled.
Another object of the present invention is to provide a more compact lamp and socket construction.
The foregoing objects are achieved in the present invention wherein the assembly comprises a lamp having a base comprising a first cylinder having means to support the wire leads from the lamp. A socket collar, comprising a second cylinder, an annular ring, and indexing and latching means, is connected to the reflector or panel with the annular ring acting as both an interference or labyrinth seal and a reference plane. An electrical connector is positioned by the collar and can be held in place either by the collar or by latch means on the lamp base.
BRIEF DESCRIPTION OF THE DRAWINGS
A more complete understanding of the present invention can be obtained by considering the following detailed description in conjunction with the accompanying drawings, in which:
FIG. 1 is an exploded perspective view of a preferred embodiment of the present invention.
FIG. 2 is an exploded perspective view of an alternative embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a lamp and socket assembly in accordance with the present invention comprises a wire lamp 11, a lamp base 21, a socket collar 31, and a suitable connector 43. Specifically, bulb 11 is a wire lamp comprising a suitably transparent vitreous envelope 12 having a formed seal area 13 from which lead wires 14-17 and the residue of the exhaust tube 18 extend.
Base 21 comprises a suitable plastic capable of withstanding the operating temperatures of the lamp. Base 21 comprises a cylindrical member having a hollowed-out or enlarged portion 22 which fits around formed seal area 13 and is attached thereto by a suitable cement, known in the art. Base 21 further comprises an annular ring 23 which forms a step with lower portion 24 of base 21. Protruding from the lower side of base 21 are a plurality of pins, such as pin 25, having locking means 26 formed therein. Further, pins 25 comprise an axial groove 27 for receiving respective ones of leads 14-17 which extend through the central portion of base 21 and are wrapped about pins 25 and lie in the axial groove. Index pin 28 also extends axially from lower portion 24 and rotationally aligns the lamp about its axis.
Socket collar 31 also comprises a suitable plastic material which can be more flexible than that of base 21. The collar is molded in a generally cylindrical shape having an inside diameter 32 approximately equal to the outside diameter of lower portion 24 of base 21. Extending radially outward from the upper end of collar 31 are a plurality of locking tabs 33-35 for rear insertion of the collar. As indicated in FIG. 1, locking tabs 33-35 are preferably distinguishable to provide an indexing function, i.e., so that the collar can be inserted into a panel or reflector in only one manner. If desired, locking tabs 33-35 may include a beveled portion to facilitate the insertion thereof into a suitably shaped hole in the panel or reflector (not shown). Collar 31 comprises an outer annular ring 37 which rests against the panel or reflector to provide an interference seal against dirt and moisture. For this reason, annular ring 37 comprises at least 50% of the area defined by a circle having the same outside diameter. Collar 31 further comprises an inner annular ring 37a for receiving respective prongs 25 from lamp base 21. Notch 38 receives index pin 28. Lower end 39 of collar 31 is also provided with radially extending locking tabs, such as tab 40, having beveled portion 41 to provide a front insertion capability for the lamp and socket assembly.
Connector 43, which may also comprise a molded plastic, has an outer shell 44 having an outside diameter approximately equal to the inside diameter of lower portion 39 of collar 31. Shell 44 is provided with a cut or groove 45 for holding connector 43 in place by way of bead 42. Alternatively, recesses may be provided for receiving shoulders 26 on elongated pins 25 of the lamp base. Indexing of connector 43 is obtained by way of ridge 46 in collar 31 and groove 47 in connector 43.
Within shell 44 are a plurality of contact pins 49 having conductive tabs 50 fastened to the outside thereof. Conductive tabs 50, in turn, are connected to conductors 51 which supply power to the lamp.
Connector 43 is inserted into collar 31 against a stop defined by inner annular ring 37a. The lamp is inserted into the other side of collar 31 where prongs 25 engage inner annular ring 37a, thereby securely fastening the elements together. The entire assembly can then be inserted from the rear into a panel or reflector. Conversely, if front insertion is utilized, collar 31 is first attached to the base, the lamp inserted, and the connector attached afterward. While the lamp and socket assembly is illustrated in a preferred embodiment as being three separate pieces, collar 31 may be advantageously combined with either lamp base 21 or connector 43 as a one-piece unit. These and other modifications are illustrated in FIG. 2 in an alternative embodiment of the present invention.
Specifically, in FIG. 2, the lamp base and collar have been combined into an integral unit 53 adapted for rear insertion into a panel or reflector and into which connector 80 is securely fastened to seal the lamp. Lamp unit 53 comprises a wire lamp having an envelope 54 from which lead wires 55-58 extend. Base 60 of lamp unit 53 comprises a molded plastic unit having a central cylindrical member 61, a portion of the interior of which is suitably shaped to receive the seal area of envelope 54, to which it is attached by any suitable adhesive known in the art. Surrounding cylindrical portion 61 is a first annular ring 62 having locking tabs 63 and 64 for securing the lamp unit to a panel or reflector. Extending from annular ring 62 is a second cylindrical section 66 having a diameter larger than the diameter of the first cylindrical section. Cylindrical sections 66 and 61 and annular ring 62 define a chamber 67 for receiving connector 80.
The lower portion of cylindrical section 66 is terminated in a second and larger annular ring 71, which corresponds to annular ring 37 in FIG. 1, i.e., is of a sufficient width to provide an interference seal for the lamp assembly. As a convenience to the user, tabs such as tabs 72 and 73, orthogonal to annular ring 71, may be provided to assist in the twisting action utilized to insert and lock lamp assembly 53 in place. Extending from the lower portion of annular ring 71 are suitable locking members, exemplified in FIG. 2 as comprising tab 74 and tapered shoulder 75.
In the interior of lamp assembly 53, central cylindrical member 61 terminates in a plurality of pins 76-78, around which are wound lead wires 55-58, respectively. While illustrated in FIG. 2 as comprising a two-filament lamp having two of the lead wires, 56 and 57, joined to form a common lead, it is understood by those of skill in the art that the base and collar unit 60 is also suitable for use with a single-filament lamp or, with an additional pin, for use with a lamp having four independent leads.
Connector unit 80, molded of a suitable resilient plastic known in the art, comprises a cylindrical unit dimensioned to fit within chamber 67. The outer surface of cylinder 81 comprises tapered ridges 82 and 83 which serve to seal connector 80 in place. Cylinder 81 further comprises a shoulder 84 extending around at least a portion thereof for engaging annular ring 71 thereby providing a stop to limit and control the insertion of connector 80.
The lower portion of connector 80 comprises wires 87-89 terminated in conductive contacts 91-93 which extend into the interior of cylinder 81 to make contact with lead wires 55-58, respectively. The lower portion of cylinder 81 is closed by floor 94. Thus, connector 80 is closed on three sides and fits into base 60 which is also closed on three sides. When connected, the combination effectively seals the contact area and provides a mechanically and electrically secure connection between wires 87-89 and lamp 53.
Although held in place by ridges 82 and 83, connector 80 is securely fastened to lamp 53 by way of locking tabs such as tab 96 having an aperture 97 into which tapered shoulder 75 fits. Tab 96 is attached to the lower portion of connector 80 including floor 94 and the extended portion surrounding wires 87-89.
To facilitate removal of connector 80, opposed tabs such as tab 98 are provided which are mechanically coupled to the locking tabs such that the locking tabs can be flexed out of position to clear tapered shoulder 75 and enable removal of connector 80. As is apparent to those of skill in the art, locking tabs 63 and 64 as well as the tabs on connector 80 may be asymmetrically located about the axis of the assembly to provide an indexing function.
Conductive contacts 91-93 comprise flat sheet metal strips curved back on themselves to form a resilient contact and are crimped or otherwise suitably fastened to the ends of wires 87-89. The leads are held in place by spring tab 101 and tapered ridge 102 which abut shoulders 103 and 104, respectively. Tapered ridge 102 also serves as a seal for the wire, preventing water or dirt from entering the contact area.
There is thus provided by the present invention a lamp and socket assembly which is compact, easily made, and mechanically accurate in the positioning of the filament relative to a panel or reflector. In addition to being mechanically secure, the electrical connections are more reliable due to the separate enclosure of the contact area, which is in addition to the sealing of the panel or reflector by the annular ring.
Having thus described the invention, it will be apparent to those of skill in the art that various modifications may be made within the spirit and scope of the present invention. For example, while described in FIG. 2 as combined with the base, the collar may be combined with the connector instead and comprise a softer plastic. With presently available materials, base 60 in FIG. 2 must be a hard plastic, i.e., capable of withstanding lamp operating temperatures. As such, a gasket may be desired for a moisture tight seal in some applications. Also, other forms of turning aids can be substituted for tabs 72 and 73 described in the embodiment of FIG. 2. Lead wires 87-89 and contacts 91-93 may be molded into connector 80 in a single operation rather than separately forming the plastic part and inserting the wires as indicated by FIG. 2. Rather than two sets of locking tabs on the socket collar of FIG. 1, a single set may be used and the socket collar reversed for either front or rear insertion. While a preferred embodiment is described in connection with a two-filament lamp, the teachings of the present invention apply to a single-filament lamp as well. | 4y
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This is a division of application Ser. No. 639,307, filed Aug. 9, 1984, now U.S. Pat. No. 4,597,433.
BACKGROUND OF THE INVENTION
The prior art is replete with smog abatement processes using ammonia to react with sulphur dioxide, but recovery of ammonium compounds for sale as byproducts increase power plant costs instead of reducing them. Likewise the resulting ammonium-sulphur compounds and particulates in minute amounts produce a plume and smog from power plant chimneys, which is as objectionable as a sulphur oxide smog.
Currently, the least expensive processes being used for power plant pollution abatement provide for scrubbing the flue gas with a limestone slurry. But, locally mined limestone is rarely available, and capital and operating costs for grinding the limestone, and disposing of precipitated gypsum mixed with fly ash, is expensive. Additional costs for electrostatic precipitators or baghouses are the rule rather than the exception. Typically, the amount of limestone or dolomite required to capture all the sulphur from a high sulphur coal is about equal to the weight of ash in the coal, so massive amounts are needed.
Heretofore, power plant recuperators of heat from flue gas have been so subject to corrosion by sulphur acids condensing out from the gas at temperatures of 300° F. or less that they have not been economical, since downtime for repairs is enormously expensive.
In the prior art, flue gas traveling at high velocities has been exposed to scrubber water to remove SO 2 , wherein film coefficients slow absorption. The physical chemistry at gas speeds of only a foot a second, where fog particles are involved, is quite different from that when speeds of 10 to 40 feet per second existant in conventional practice. The enormous cost of acid resistant metal vessels made large enough to reduce speeds of gas flow through them has prevented them from even being considered.
It is noted in passing that in my previous U.S. Pat. No. 4,054,246, there is disclosed the novel concept of preheating air needed for combustion of power plant fuel by recuperation of the heat in flue gases, using subterranean pits filled with gravel. Further, in my U.S. Pat. No. 4,173,034, the advantages of heat storage in very large beds of pebbles are disclosed in some detail.
Those skilled in the chemical process arts generally appreciate that regenerative and recuperative heaters have been known for centuries. That this is still an active area of development is evidenced by three recent U.S. patents, U.S. Pat. No. 4,383,573; U.S. Pat. No. 4,349,069; and U.S. Pat. No. 4,361,183, all assigned to Combustion Engineering Inc., which all disclose regenerative heaters, but which are not otherwise pertinent to the present invention.
While the terms "regenerative" and "recuperative" are frequently used in the alternative it is believed that more proper definitions suggest that "regenerative" implies a closed system whereas "recuperative" implies systems where energy may be added (e.g. not a closed system). Insofar as the present invention is of the former type "regenerative" will be used herein.
OBJECTS OF THE INVENTION
It is a general object of the present invention to provide improved means for pollution control for coal-burning boilers and the like.
A further object of the present invention is to provide improved means of heat and byproduct recovery from flue gases.
A still further object of the present invention is to provide improved means of heat and byproduct recovery for boiler flue gases and the like which are an economic benefit to the overall operation.
Still another object of the present invention is to provide a pair of pebble bed regenerators of very large surface area, whereby flue gas velocities are reduced, fogs/smogs are encouraged to form, and cooling to the ambient range is achieved.
Yet another object of the present invention is to recover heat and byproducts from flue gases heretofore generally wasted.
These and other objects and advantages of the invention will become clear from the following detailed description of embodiments of same, and the novel features will be particularly pointed out in connection with the appended claims.
THE DRAWINGS
Reference will hereinafter be made to the accompanying drawings, in which:
FIG. 1 is a simplified flow sheet or flow diagram illustrating an embodiment of the invention;
FIG. 2 is a simplified diagram illustrating the concepts of condensate recovery and heat storage in accordance with the invention;
FIG. 3 is a partial, cross-sectional elevation view, highly idealized, of a small portion of a pebble wall or block within the pebble bed of the invention;
FIG. 4 is a partial, isometric cross-sectional view of the top or upper portion of a pebble bed illustrating removal of some dry flash ash prior to cooling-condensation carried out within the bed;
FIG. 5 is a transverse, vertical cross-sectional view of a pair of pebble beds in accordance with the invention; and
FIG. 6 is a longitudinal, vertical cross-sectional view of a pebble bed, taken along line B--B of FIG. 5.
DESCRIPTION OF EMBODIMENTS
In essence, the present invention is based, at least in part, on the discovery that current pollution control systems largely waste sensible heat in flue gases below certain temperatures, largely because of their corrosive nature at such temperatures, and that vast sums of money are spent overcoming the corrosiveness, when indeed a better approach is to employ acid-resistant materials under conditions controlled so that contained sulphur is never oxidized to sulphuric acid, but is rather recovered as marketable SO 2 . The expense of neutralization is thus avoided, a marketable byproduct is produced and, most important, by utilizing the previously-wasted sensible heat to preheat combustion air going to the boiler, savings of truly surprising dimensions are achieved, as set forth in more detail hereinbelow.
In its important aspects the invention is illustrated in the flow sheet of FIG. 1, and attention is directed thereto. Those skilled in the chemical process industries ("C.P.I.") will immediately appreciate the lack of conventional recovery equipment: precipitators, bag houses and, of course, the input of limestone or dolomite necessary to chemically bind the sulfur. Rather, there are a pair of pebble or rock beds. These beds are truly massive, being as large as 75×150×60 feet, and are formed of sized, acid-resistant aggregate (manufactured or natural stone) providing myriad tortuous paths for cooling gases and condensing fluids.
Before discussing these aspects of the invention in detail, however, it is important to note that FIG. 1 is greatly simplified for purposes of clarity and, for example, does not show steam or power as an output. Rather, it merely shows preheated air as an input and flue gas as an output. Both of these flows are shown as passing through a High Temperature Regenerator, which is a conventional unit forming no part of the present invention. However, it is preferred that those units (two are of course necessary) be Ljunstrom-type rotating wheels with closely-spaced metal vanes forming rings around the vertical axis of rotation. Such units have proven efficient and economic between boiler exit gas temperatures and those lower temperatures at which SO 2 starts to oxidize and become corrosive, normally below about 500° F. As set forth in more detail hereinbelow, however, the physical chemistry is more complex than meets the eye, and specifying a temperature or even temperature range can be a dangerous generalization.
In any pair of regenerative heaters, it is manifest that the sensible heat retained in one is used to preheat incoming, ambient air prior to combustion in the boiler and, at the same time, hot flue gas is cooled in the other, giving up its heat to the walls of same. What distinguishes the present invention is the much greater extent to which this is carried out.
As noted supra, at lower temperatures in the range of 500° to 200° F., this invention makes use of porous gravel or sized pebble beds. These are in the range of about 1.5 to 6 inches diameter, with closely sized 2 inch diameter gravel chosen in the FIGURES and EXAMPLES described hereinbelow. Preferably, the beds are large enough in area and thickness so gas flow need not be reversed by dampers more often than once every eight hours. Such dampers or valves have been common in iron blast furnace stoves for about 100 years.
After cooling in the pebble bed the flue gases may occupy as little as half the volume they do when entering, due both to condensation of contained water, which involves a volume reduction of 950 to 1, and contraction according to the gas laws, e.g. PV=RT. Therefore, fan power to push the clean gas up the power plant chimney is not excessive. Since both particulate and gaseous pollutants that are noxious have been removed in the pebble bed, the need for a stack at all is merely to mix the CO 2 and whatever minor CO is present with atmospheric air.
Of course, in a bed preheating ambient air, more-or-less of the reverse holds true: expansion according to the gas laws and vaporization of any moisture, which will be a variable.
As shown in FIG. 1, the condensate, with its contained SO 2 entrained in the water of condensation together with NO x , chlorides, and other trace elements, is bled out of the bottom of the recuperator into a settling vessel or pond where clear water containing SO 2 is continuously or occassionally removed to a vacuum vessel for evaporation of SO 2 and its compression to a liquid, which is conventionally stored in refrigerated tank cars not under appreciable pressure. After SO 2 removal, the cold water is returned to the recuperators for washing out any fly ash accumulation and to keep the lowest level of the bed cold, to collect smog while the level of the bed immediately above is reaching hot flue gas temperature. This ensures that the smog will have at least a few feet to travel a tortuous path downward through the pebbles, wet with condensate, and be entrapped thereon.
The physical chemistry of this invention may be better understood by consideration of FIG. 2, which is a simplified diagram illustrating smog recovery in condensate water while storing heat in a pebble. In essence, this involves certain physical and thermal interactions between a pebble 10, a covering film of water 12, and smog droplets 14 nucleated on flyash or other particulates 16. As in nature, condensation may start on a particle of flyash 16, since it acts as a nuclei. This condensing fog is distilled water, and, as shown by several scientific papers over the past 24 years, the reaction of SO 2 with H 2 O in this miniscule state is practically instantaneous, even as acidity increases. Reference is made to "SOME ASPECTS OF SO 2 ABSORPTION BY WATER-GENERALIZED TREATMENT" by Gregory R. Carmichael and Leonard K. Peters, published by Pergamon Press Ltd. 1979 in ATMOSPHERIC ENVIRONMENT Vol. 13 pp. 1505-1513. In nature, smog returns to earth when the droplets become large enough to make "heavy" fog or dew. As shown in FIG. 2, droplet 14' has reached film 12 and is attaching as at 18 by surface-tension, but will rapidly become part of film 12. Indeed, in climates where fogs are common, noxious smogs have sometimes produced a rash of fatalities.
FIG. 3 is an idealized cross-section through a porous, pebble wall or pebble block of the invention, wherein evenly-sized crushed rock or pebbles, shown as spheres but actually of more irregular shape, are cemented together at just the points of contact of each pebble with its adjoining pebbles. This is accomplished by mixing the pebbles with a cementing slurry or thick cementing liquid, dumping the mix into a form and jarring or vibrating the form or contained pebble mix sufficiently so that all that remains of the cementing slurry or thick cementing liquid is that which thinly coats the pebble surfaces and which adheres principally around the points of contact of one pebble with its adjoining pebbles. For many purposes in construction of porous walls, floors, ceilings or the like, the slurry may consist of Portland cement with or without fine sand admixed, and water. In the case of the regenerators of this invention, acid resistance is a key element and the cementing slurry should be a fireclay, resin, plastic with or without fine quartz sand admixed and water or other liquid. The pebbles are preferably quartz or volcanic rock with lower coefficient of expansion when subjected to repeated heating and cooling. The chemical industry has produced a great many conventional acid-proof cements which may be employed.
A most important aspect of the present invention is the exceptionally large area of the pebble heaters, which means that gas velocity therethrough will be very low. In the case of the incoming flue gas, this means that a substantial portion of the contained fly ash, e.g. the larger particles, will cease to be carried by the gas stream and will "drop out." FIG. 4 is an isometric view of means for coarse fly ash catchment over the pebble beds, with conveyance to downspouts by long prism-shaped pebble masses or blocks 22, having a triangular cross-section, made porous as in FIG. 3, but faced on the upper surface with a very hard and smooth slab 24 of acid resistant concrete, so the fly ash accumulating thereon will slide off into acid proof tile gutters 26 which include a gas permeable bottom, so fly ash falling therein is conveyed to downspouts (not shown) by fluidized flow. The prism shapes 22 are precast in forms and arranged on top of each pebble bed regenerator so they act like snow fences in causing the great bulk of fly ash to fall into the gutters directly or onto the smooth prism faces sloping at about 45 degrees, so any considerable depth of fly ash accumulating slides off into the gutters just as snow slides off a metal roof. The gas fed under the false bottom of the gutters must be very clean, dry and hot so that it will never plug the pores of the false floor of the gutters or cause the fly ash to cake in its route to the downspouts and bins (not shown) below the pebble beds. Alongside the gutters are acid proof tile pipes 27 with perforations on their sides opposite the gutters for flooding the pebble beds occassionally as needed to quickly flush down any accumulation of light fly ash between pebbles, which has not been carried down by the water of condensation from the flue gases. The upper layers of the recuperators are easily accessible for repair or replacement of prism shapes, gutters, flooding conduits or pebbles although little maintenance is contemplated, insofar as with time-proven materials of construction the pebble bed should last the life of the power plant. Some crumbling of pebbles is not serious, unless travel of flue gas becomes impeded.
FIG. 5 is a transverse. vertical section and FIG. 6 is a longitudinal vertical cross-section through a preferred embodiment of the pebble beds 28, 30 of this invention, and featuring low construction and operating costs in comparison with conventional means now employed to carry out the functions of collecting fly ash, cooking the flue gases and removing the noxious and very fine particulates and noxious gases therefrom. This is true despite the very substantial size of these beds.
The beds are in the order of 10 to 80 feet deep or more; this, of course, depends on the size of the power plant. Preferably, the beds are closely sized, spherically-shaped, and are of acid-resistant composition, so as not to be subject to deterioration by repeated heating and cooling, over 20,000 cycles, between 50° F. and 300° F. Any pebble (32) layer may be a single size from about 3/4 inches diameter to 5 inches or more, but smaller pebbles must not be above larger ones. Smaller sizes have more surface to promote SO 2 recovery in the condensate but have a much higher resistance to flue gas flow, and there is greater danger of plugging pore spaces. If mixed sizes were used, of course, gas flow would all but cease.
The horizontal cross-section of the beds is made large enough to slow flue gas speeds downwardly to about 1 foot per second or less at the entering face, which may be only half the velocity at the bottom of the bed due to cooling-contraction. As the hot flue gases reach the enormous area of the precooled pebbles, they are slowed to perhaps one-fifth or one-tenth of their previous speed, and at once start dropping their coarse fly ash on the prism-shaped "show fences," and thence into the gutters. As the partially cleaned flue gases enter the previous cooled bed, the heat capacity of the first foot or two of pebble layers condenses enough moisture to produce a steam-fog and smog out of fly ash, condensed moisture and very fine fly ash. As discussed supra in connection with FIG. 2, the droplets grows in size, its momentum inevitably causes it to collide with the already wetted surface of a pebble, where it is entrapped with further condensate and washed downwardly over colder pebbles so the SO 2 , once absorbed, tends to be retained. As in "Principles of Chemical Engineering" by Walker, Lewis and McAdams explained almost 60 years ago: "Thus, if SO 2 gas, whether or not mixed with inert gas, be brought in contact with water at 20° C., the SO 2 will continue to dissolve in the water until its concentration is sixty times that in the gaseous phase." It should be noted that the cooling of the flue gas is done at the face of a pebble so condensation and simultaneous solution of SO 2 must primarily occur there.
It should be appreciated that the top layers of rocks in the beds will heat up first, while the layers beneath remain cool. The absorbing surface and heat capacity of the rocks is so great that the heating of layers proceeds like a wave. Each successive layer will reach something close to flue gas temperature before the rate of heat transfer slows appreciably and the next layer starts to warm up. But, hot water of condensation, running downwards will speed the process somewhat. The beds must be deep enough so that the lowest layer is cool, and will condense all the water in the flue gases and, furthermore, provide a layer of cool pebbles, so that the smog in twisting and turning around pebbles will be entrapped on the water film covering each pebble.
EXAMPLES
Some specific examples will aid in understanding the invention are set forth hereinbelow. Base-line power plant data has been taken from an E.P.A. study, "Rocky Mountain-Prairie Region VIII: Coal-Fired Power Plant Trace Element Study, A Three-Station Comparison" by Radian Corp., Austin, Tex. Example I below is derived therefrom as denoted (*), and in Example II it is as noted thereunder (**). Thus, data in Table I below is * from Vol. 1, page 11, Table 2-2, and in * Table II it is from Vol. 2, page 27, Table 4-1.
TABLE I______________________________________Station II Flow Rates______________________________________Coal: 2.75 × 10.sup.5 lb/hr = 3300 tons/dayFlue gas: 5.46 × 10.sup.7 scfh______________________________________
TABLE II______________________________________Station II Coal Analysis As Rec'd, Pct. Dry______________________________________Moisture, 29.19Ash, 5.12Volatiles, 30.15Fixed Carbon, 35.54BTU/lb 8290 11,708Ultimate, Pct.Carbon 48.31Hydrogen 6.53Nitrogen 0.67Oxygen 39.02Sulphur 0.35Ash 5.12______________________________________
By estimating the amount of heat which can be recuperated from the flue gases of one pound of coal to preheat the air needed for its combustion, the tons of coal saved by this invention each day can be readily obtained. First, the heat in the steam condensed from the gases is estimated. Second, the sensible heat in cooling the gases down from 300° F. to 50° F. is estimated. The sum of these BTU savings is the increase in the heating value of the coal. Thus, fewer tons will be needed. Heat recovered conventionally (from gases at boiler temperature down to 300° F.) is not included.
Those familiar with heat and material balances will appreciate that total moisture in the boiler flue gases includes all water made from H 2 during combustion, plus moisture in and on the coal, and moisture in the combustion air. In Table III below, data for calculating the latter figure have been taken from "Combustion Engineering" (First Ed.) pp. 25-25 and 25-26, which assume 22% excess air and 34% volatiles, deemed reasonable.
TABLE III______________________________________Heat of Condensation/lb. CoalSource H.sub.2 O per lb.______________________________________Wet coal (as rec'd.) 0.2919Combustion (from H.sub.2) 0.5877(0.0653 × 9)In Comb. Air 0.1007 0.9803______________________________________
So, with a heat of condensation of 950 BTU/lb, there is
0.9803×950=930 BTU
recoverable from this water. The sensible heat in these gases is, in essence, that recoverable in cooling from 300° F. to about 50° F.
TABLE IV______________________________________Sensible Heat in Flue Gases(per one pound of coal)______________________________________ 980 (from Table III)5.46 × 10.sup.7 scfh/2.75 × 88610.sup.5 = 198.54 scfhper lb. coal198.54 × 0.238 × 0.075 ×250 =[scfh × (sp. heat) ×lb/cf × F.° temp. change]TOTAL 1816______________________________________
The recuperator efficiency is 95% both in and out, =90.25%×1816=1639 BTU. Thus, the equivalent heating value of coal, attained by invention by conservation is =8290+1639=9929 BTU. So if
Y=tons coal/day with invention, then Y×9929=3300×8290. So Y=2755 tons coal per day 3300-2755=545 tons coal saved. At $40/ton, this equals a saving of $21,800/day.
The design of FIGS. 4, 5, 6, 7 and 8 comprises a pair of pebble beds, which, to be properly effective should each be 75 ft. wide by 150 ft. long and 60 ft. deep. Pebbles are closely sized quartz pebbles or volcanic rocks about two inches in diameter. The heat capacity is calculated below for one of the pair of recuperator beds.
TABLE V__________________________________________________________________________Bed Heat CapacityVolume Rock Density % Solid Specific Temperature HeatOf Bed of Solids Rock Heat Change/cycle Capacitycu. ft. lbs/cu. ft. (voids = 42%) BTU/lb degrees F. BTU__________________________________________________________________________75 × 150 ×60 = 6.75 ×10.sup.5 × 165 × 0.58 × 0.21 × 250 = 3.391 × 10.sup.9__________________________________________________________________________
The heat recuperated per day is: 1639/lb×2000×2755 tons=9.03×10 9 . Therefore, the dampers reversing the flow through the beds need to be set to change once every 8 hour shift, although 9 hours allowable.
The flue gas speed downward and combustion gas speed upward are calculated as follows:
5.46×10 7 scfh×(2755/3300÷[60 (min./hr.)×11,250 sq.ft.]=68 ft/min, or about 1 ft. per second. The pressure necessary to force this flow with 2 in. diameter pebbles is about 0.08×60 ft. (depth) or 4.8 inches water. The weight of 4.8 inches of water spread over 150×75 sq. ft. is 281,250 lbs. which, moving at 1 ft./sec., becomes ftlb/sec. Since a kilowatt is equivalent to 737.7 ft.lb/sec., a fan of 281,250/737.7 or about 380 kw is required for each of the recuperators in the pair. Each would add 380×0.948×60×60=12×10 5 BTU/hr friction heat), equivalent to about 1.5 tons coal/day.
The recovery of SO 2 is readily obtained from a calculation of the %SO 2 in the flue gas, compared to the SO 2 recovered in the water of condensation, bearing in mind that equilibrium will be reached and further recovery will cease, when the condensed SO 2 equals 60 times the concentration by weight in the flue gas. In this EXAMPLE I., if all the SO 2 were to remain in the flue gas, it would contain %S=0.35×2=0.70% SO 2 /per lb. of coal.
TABLE VI______________________________________SO.sub.2 ExtractionDegree of 60 × % SO.sub.2 in Con-Extraction of SO.sub.2 SO.sub.2 in % SO.sub.2 densate by Ex-From the Flue Gas Flue Gas in Flue Gas traction Process______________________________________0 0.047%*** 2.82% 020% 0.0376% 2.256% 0.143%40% 0.0282% 1.692% 0.286%60% 0.0188% 1.128% 0.429%80% 0.00940% 0.564% approx. = 0.572% at approximate equilibrium90% 0.00470% 0.282%* 0.643%100% 0 0 0.715**______________________________________ Notes Explaining Derivation of Figures in above Table ***The SO.sub.2 in the flue gas at 0% extraction is calculated as follows % SO.sub.2 in coal is 2 × % S = 0.70% or 0.007 lbs/lb coal. Since scfh flue gas/lb coal = 5.46 × 10.sup.7 /2.75 × 10.sup.5 = 198.54 scfh, then lb flue gas/lb coal = 0.075 lb/cf × 198.54 = 14.8 lb SO.sub.2 /lb flue gas = 0.007/14.89 = 0.00047 = 0.047% **The SO.sub.2 in the condensate at 100% extraction is calculated as follows: % SO.sub.2 in coal is 2 × % S = 0.70% or 0.007 lbs/lb coal The condensate was previously calculated as 0.9796 lbs, so the SO.sub.2 /lb condensate = 0.007/0.9796 = 0.00715 = 0.715% *The 90% extraction is achievable by diluting the condensate with fresh water or condensate from which the SO.sub.2 has been removed by vacuum. This dilution would be done by flooding the lower 10 ft. of pebble bed. That is, by adding 1.3 lb fresh water to 1 lb condensate making 2.3 total The 0.643% SO.sub.2 is reduced to 0.643/2.3 or 0.280%, comparable with 0.282% which is the amount of flue gas SO.sub.2 water at equilibrium with flue gas containing 0.00470% (see Walker, Lewis and McAdams reference, supra).
EXAMPLE II
A North Dakota Coal is considered in the following example. References to the EPA study (supra) are Table 2-3, p. 12, Vol. 1, and Table 4-1, page 28, Vol. 4.
TABLE VII______________________________________STATION III FLOW RATESSTREAM FLOW RATE______________________________________Coal 2.34 × 10.sup.5 lb/hrFlue Gas 4.11 × 10.sup.7 scfh______________________________________
TABLE VIII______________________________________STATION III COAL ANALYSIS As Received, Pct______________________________________ProximateMoisture 36.84Ash 7.84Volatiles 26.24Fixed Carbon 29.08 100.00Sulphur 0.91BTU/lb 6214Ultimate, Pct.Carbon 41.91Hydrogen 6.77Nitrogen 0.60Oxygen 41.97Sulphur 0.91Ash 7.84 100.00______________________________________
To calculate the coal which can be saved with this North Dakota coal used in a power plant by using the invention, the same procedure applies as used in Example I. Savings by recuperating the heat of the condensate and sensible heat in the flue gases are computed below and added together.
__________________________________________________________________________HEAT OF CONDENSATION = POUNDS H.sub.2 O × 950 BTU/lbper one pound of coalH.sub.2 O as moisture in coal 0.3684H.sub.2 O from hydrogen (0.0677 × 9) 0.6093H.sub.2 O in air for combustion 0.07550.013 × 935 lb air0.006214 coal heat valueper million BTUTotal lb H.sub.2 O per lb coal ##STR1##SENSIBLE HEAT IN FLUE GASES(per one pound of coal)4.11 × 10.sup.7 scfh/2.34 × 10.sup.5 =175.68 × 0.238 × 0.075 × 300°(scfh/lb coal) (sp.ht.) (lb/cu. ft.) F.° temp change = SENSIBLEHEAT 940Recuperator efficiency in & out 90.25% × TOTAL 1940 = 1750Heating value of coal obtained by invention = 6214 + 1750 = 7964__________________________________________________________________________BTU/l
To determine the coal saved per day, again let Y=coal used per day, with the invention, then Y×79.64=2808×6214, so Y=2191.
The tons saved per day=2808-2391=617; so dollars saved per day=617×$40/ton coal=$24,680/day.
Besides the coal saving, the invention greatly reduces SO 2 pollution as the following Table IX illustrates.
TABLE IX______________________________________EXTRACTION OF SO.sub.2Degree of 60 × % SO.sub.2 in Con-Extraction of SO.sub.2 SO.sub.2 in % SO.sub.2 densate by Ex-From the Flue Gas Flue Gas in Flue Gas traction Process______________________________________ 0% 0.138%*** 8.28% 020% 0.110% 6.62% 0.34%40% 0.083% 4.98% 0.69%60% 0.055% 3.30% 1.04%80% 0.014% 1.68% 1.38%90% 0.014% 0.83%* 1.56%*100% 0 0 1.728%**______________________________________ Notes explaining this Table ***The SO.sub.2 in the flue gas at 0% extraction is calculated as follows % SO.sub.2 in coal is 2 × % S = 1.85% or 0.0182 lbs/lb coal and since scfh flue gas/lb coal 4.11 × 10.sup.7 /2.34 × 10.sup.5 = 175.64 scfh so lb flue gas/lb coal = 0.075 lb/cf × 175.64 = 13.17 lb SO.sub.2 /flue gas = 0.0182/13.17 = 0.00138 = 0.138% **The SO.sub.2 in the condensate at 100% extraction is calculated as follows: % SO.sub.2 in coal is 2 × 5S = 1.82% or 0.0182 lbs/lb coa and since lb condensate was previously calculated as 1.0532 the SO.sub.2 /lb condensate is 0.0182/1 = 0.01728 = 1.728% *The 90% extraction is calculated achievable by diluting the condensate with fresh water or condensate from which the SO.sub.2 has been removed b vacuum. This dilution would be done by flooding the lower 10 ft, of pebbl bed. That is, if an amount of fresh water equal to that in the condensate were added, the % SO.sub.2 in the condensate would be halved from 1.56% t 0.78% which is lower than 0.83% in equilibrium with flue gas containing 0.014% SO.sub.2. (see Walker, Lewis and McAdams reference previously given)
In calculating the heat of condensation used in both examples, a figure od 950 BTU/lb water condensed was used when actually the accepted standard is 1050.3. This makes the above estimates of saving on the conservative side.
As a rough estimate this invention recovers about 90% of the high heating value. The recuperator efficiency of 95% in and 95% out equals 90.25%. Thus, the coal industry as well as the power industry are enormously benefitted both by the coal savings, as well as making high sulphur coal valuable without causing air pollution.
Although these examples show the use of coal, it will be appreciated that savings with oil and natural gas furnaces will be greater to the extent that H 2 O condensate is greater, due to more hydrogen in the oil or gas.
Various other changes in the details, steps, materials, and arrangements of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in this art within the principle and scope of the invention as defined in the appended claims. For example, it will be appreciated that while this invention has been described with reference to boiler installations for power generation from fossil fuels, it is not so limited and may be employed with any large-scale furnaces burning such fuels; copper smelting, glassmaking or pig iron or scrap melting operations come to mind. | 4y
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This application claims the benefit of a U.S. Provisional Application 60/022,509 filed Jun. 28, 1996, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a cosmetic product that can stably store ascorbic acid and then deliver same to the skin.
2. The Related Art
Ascorbic acid, also known by its common name of Vitamin C, has long been recognized as an active substance benefiting skin appearance. Vitamin C reportedly increases the production of collagen in human skin tissue. Wrinkles and fine lines are thereby reduced. An overall healthier and younger-looking appearance results. Vitamin C has also found utility as an ultraviolet ray blocking or absorbing agent. Whitening or bleaching skin compositions have also employed Vitamin C utilizing its property of interference with the melanin formation process. There also is a belief that ascorbic acid interacts with the human immune system to reduce sensitivity to skin aggravating chemicals. Reduced levels of Vitamin C concentration on the skin have also been implicated with an increase in stress. From all of the foregoing perspectives, Vitamin C or ascorbic acid may provide significant benefit when topically applied.
Unfortunately, Vitamin C is a very unstable substance. Although it is readily soluble in water, rapid oxidation occurs in aqueous media. Solubility of ascorbic acid has been reported to be relatively poor in nonaqueous media, thereby preventing an anhydrous system from achieving any significant level of active concentration. A system is necessary for dissolving or at least uniformly suspending Vitamin C which is also chemically compatible with the active.
The art has sought to overcome the problem in a variety of ways. One approach is the preparation of ascorbic acid derivatives. These derivatives have greater stability than the parent compound and, through biotransformation or chemical hydrolysis, can at the point of use be converted to the parent acid. For instance, U.S. Pat. No. 5,137,723 (Yamamoto et al) and U.S. Pat. No. 5,078,989 (Ando et al) provide glycosylate and ester derivatives, respectively.
U.S. Pat. No. 4,818,521 (Tamabuchi) describes under the background technology a so-called two-pack type cosmetic wherein Vitamin C powder and other ingredients are separately packaged in different containers with mixing just prior to use of the cosmetic. The mixing procedure and expensive packaging were said to be drawbacks of this system. The patent suggests stable oil-in-water type emulsions that are weakly acidic and wherein ascorbic acid has been premixed with a stabilizing oil.
Maintenance of pH below about 3.5 has also been suggested in U.S. Pat. No. 5,140,043 (Darr et al) as a stabilization means for aqueous compositions of ascorbic acid.
Water compatible alcohols such as propylene glycol, polypropylene glycol and glycerol have been suggested as co-carriers alongside water to improve stability. An illustration of this approach can be found in U.S. Pat. No. 4,983,382 (Wilmott and Znaiden). Therein a blend of water and water-miscible organic solvent are combined as a stabilizing system. At least about 40% of the organic solvent must be ethanol while the remainder may be selected from such alcohols as propylene glycol, glycerin, dipropylene glycol and polypropylene glycol.
Japanese Patent 44-22312 (Shionogi) describes the stabilization of Vitamin C in a mainly aqueous medium by a variety of glycols. These include polyethylene glycol, ethylene glycol, diethylene glycol and even ethanol. These formulations are intended for ingestion.
U.S. Pat. No. 4,372,874 (Modrovich) has reported incorporation of relatively large amounts of ascorbic acid in a polar water-miscible organic solvent such as dimethyl sulfoxide. Levels of water are kept below 0.5% through addition of a particulate desiccant to the carrier. Although highly polar systems such as dimethyl sulfoxide may be effective, this and related carriers are toxicologically questionable.
Accordingly, it is an object of the present invention to provide a delivery system for ascorbic acid in which the compound is soluble or at least uniformly dispersible and oxidatably storage stable.
Another object of the present invention is to provide a delivery system which assists the penetration of ascorbic acid into the human skin while avoiding irritation thereof.
Still another object of the present invention is to provide a system for delivering ascorbic acid that is aesthetically pleasing and imparts a soft and smooth skinfeel.
These and other objects of the present invention will become more readily apparent through the following summary, detailed discussion and Examples.
SUMMARY OF THE INVENTION
A cosmetic composition is provided that includes:
(i) from 0.001 to 50% of ascorbic acid;
(ii) from 0.1 to 30% of a crosslinked non-emulsifying siloxane elastomer; and
(iii) from 10 to 80% of a volatile siloxane.
DETAILED DESCRIPTION OF THE INVENTION
Now it has been discovered that ascorbic acid can be stabilized against decomposition and also stably suspended in a system containing a crosslinked non-emulsifying siloxane elastomer and a volatile siloxane. Although not wishing to be bound by any theory, it is considered that the elastomer provides a three-dimensional structure which prevents Vitamin C from precipitating from either water or oil phases. Moreover, the three-dimensional structure allows the amount of water to be minimized thereby minimizing ascorbic acid oxidation.
Ascorbic acid is available from several sources including Roche Chemicals. Amounts of this material may range from 0.001 to 50%, preferably from 0.1 to 10%, optimally from 1 to 10% by weight.
Crosslinked non-emulsifying siloxane elastomers of this invention will have an average number molecular weight in excess of 10,000, preferably in excess of 1,000,000 and optimally will range from 10,000 to 20 million. The term "non-emulsifying" defines a siloxane from which polyoxyalkylene units are absent. Illustrative of the elastomer is a material with the CTFA name of Crosslinked Stearyl Methyl-Dimethyl Siloxane Copolymer, available as Gransil SR-CYC (25-35% active elastomer) from Grant Industries, Inc., Elmwood Park, N.J. Supply of related elastomer may also be available from the General Electric Company.
Amounts of the elastomer may range from 0.1 to 30%, preferably from 1 to 15%, optimally from 3 to 10% by weight.
A third essential element of the present invention is that of a volatile siloxane. Illustrative of this category are the cyclo polydimethyl siloxane fluids of the formula ((CH 3 ) 2 SiO)) x , wherein x denotes an integer of from 3 to 6. The cyclic siloxanes will have a boiling point of less than 250° C. and a viscosity at 25° C. of less than 10 centipoise. Cyclomethicone is the common name of such materials. The tetramer and pentamer cyclomethicones are commercially available as DC 244 and DC 344 from the Dow Corning Corporation.
Amounts of the volatile siloxane will range from 10 to 80%, preferably from 20 to 70%, optimally from 30 to 65% by weight.
Compositions of this invention may further include a pharmaceutically acceptable carrier. Generally the carrier will be an ingredient which can solubilize Vitamin C and all other elements of the composition. Amounts of the carrier may range from 1 to 70%, preferably from 10 to 60%, optimally from 20 to 50% by weight.
Pharmaceutically acceptable carriers may be selected from water, polyols, silicone fluids, esters and mixtures thereof. When present, water may range from 0.5 to 20%, preferably from 1 to 10%, usually from 2 to 6%, optimally less than 5% by weight of the composition.
Advantageously one or more polyols are present as carriers in the compositions of this invention. Illustrative are propylene glycol, dipropylene glycol, polypropylene glycol, polyethylene glycol, sorbitol, hydroxypropyl sorbitol, hexylene glycol, 1,3-butylene glycol, 1,2,6-hexanetriol, glycerin, ethoxylated glycerin, propoxylated glycerin and mixtures thereof. Most preferably the polyol is a mixture of polyethylene glycol, molecular weight ranging from 200 to 2,000, and propylene glycol. Preferred weight ratios of polyethylene glycol to propylene glycol range from 5:1 to 1:10, preferably from 2:1 to 1:5, optimally 1:1 to 1:2. Amounts of the polyol may range from 1 to 50%, preferably from 10 to 40%, optimally from 25 to 35% by weight of the composition.
Silicone oils may also be included as carriers in the compositions of this invention. These oils will be nonvolatile. The nonvolatile silicone oils useful in the compositions of this invention are exemplified by the polyalkyl siloxanes, polyalklyaryl siloxanes and polyether siloxane copolymers. The essentially nonvolatile polyalkyl siloxanes useful herein include, for example, polydimethyl siloxanes with viscosities of from about 5 to about 100,000 centistokes at 25° C. Such polyalkyl siloxanes include the Viscasil series (sold by General Electric Company) and the Dow Corning 200 series (sold by Dow Corning Corporation). Polyalkylaryl siloxanes include poly(methylphenyl)siloxanes having viscosities of from about 15 to about 65 centistokes at 25° C. These are available, for example, as SF 1075 methylphenyl fluid (sold by General Electric Company) and 556 Cosmetic Grade Fluid (sold by Dow Corning Corporation). Useful polyether siloxane copolymers include, for example, a polyoxyalkylene ether copolymer having a viscosity of about 1200 to 1500 centistokes at 25° C. Such a fluid is available as SF-1066 organosilicone surfactant (sold by General Electric Company). Cetyl dimethicone copolyol and cetyl dimethicone are especially preferred because these materials also function as emulsifiers and emollients. The former material is available from Goldschmidt AG under the trademark Abil EM-90. Amounts of the nonvolatile siloxane may range from 0.1 to 40%, preferably from 0.5 to 25% by weight of the composition.
Esters may also be incorporated into the cosmetic compositions as pharmaceutically acceptable carriers. Amounts may range from 0.1 to 50% by weight of the composition. Among the esters are:
(1) Alkyl esters of fatty acids having 10 to 20 carbon atoms. Methyl, isopropyl, and butyl esters of fatty acids are useful herein. Examples include hexyl laurate, isohexyl laurate, isohexyl palmitate, isopropyl palmitate, decyl oleate, isodecyl oleate, hexadecyl stearate, decyl stearate, isopropyl isostearate, diisopropyl adipate, diisohexyl adipate, dihexyldecyl adipate, diisopropyl sebacate, lauryl lactate, myristyl lactate, and cetyl lactate. Particularly preferred are C 12 -C 15 alcohol benzoate esters.
(2) Alkenyl esters of fatty acids having 10 to 20 carbon atoms. Examples thereof include oleyl myristate, oleyl stearate, and oleyl oleate.
(3) Ether-esters such as fatty acid esters of ethoxylated fatty alcohols.
(4) Polyhydric alcohol esters. Ethylene glycol mono and di-fatty acid esters, diethylene glycol mono- and di-fatty acid esters, polyethylene glycol (200-6000) mono- and di-fatty acid esters, propylene glycol mono- and di-fatty acid esters, polypropylene glycol 2000 monooleate, polypropylene glycol 2000 monostearate, ethoxylated propylene glycol monostearate, glyceryl mono- and di-fatty acid esters, polyglycerol poly-fatty esters, ethoxylated glyceryl monostearate, 1,3-butylene glycol monostearate, 1,3-butylene glycol distearate, polyoxyethylene polyol fatty acid ester, sorbitan fatty acid esters, and polyoxyethylene sorbitan fatty acid esters are satisfactory polyhydric alcohol esters.
(5) Wax esters such as beeswax, spermaceti, myristyl myristate, stearyl stearate.
(6) Sterols esters, of which cholesterol fatty acid esters are examples thereof.
Minor adjunct ingredients may also be included in cosmetic compositions of this invention. These ingredients may be selected from preservatives, fragrances, anti-foam agents, opacifiers, colorants and mixtures thereof, each in their effective amounts to accomplish their respective functions.
The following examples will more fully illustrate the embodiments of this invention. All parts, percentages and proportions referred to herein and in the appended claims are by weight unless otherwise indicated.
EXAMPLE 1
The effect of a crosslinked non-emulsifying siloxane polymer was evaluated in contrast to related siloxanes with respect to suspension/uniform distribution of Vitamin C and resistance to oxidation under storage conditions. Formulations and test results are outlined under Table I.
TABLE I______________________________________ Example No. (Weight %) 1A 1B 1C 1D______________________________________COMPONENTCyclomethicone 55.5 60.0 55.5 55.5Polyethylene Glycol 200 20.25 20.25 20.25 20.25Water 14.0 14.0 14.0 14.0Ascorbic Acid 5.0 5.0 5.0 5.0EM-90 (Cetyl Dimethicone 0.75 0.75 0.75 0.75Copolyol)Gransil SR CYL 4.5 -- -- --(% Elastomer Active)DC 200 Fluid -- -- 4.5 --(Polydimethylsiloxane)Gransurf 671 (Ethoxylated -- -- -- 4.5Dimethicone Copolyol)ResultsAscorbic Acid Retention (%)2 weeks at RT 98.6 Phase Phase Phase separation separation separation2 weeks at 110° C. 97.84 weeks at 110° C. 87.9______________________________________
Formulation 1A was a homogeneous stable aesthetically pleasing emulsion of cream-like consistency which retained Vitamin C unoxidized for at least two weeks both at room temperature and at 110° C. By contrast, formulations 1B, 1C and 1D did not form a stable emulsion. These formulations separated and therefore did not uniformly suspend ascorbic acid.
EXAMPLES 2-5
A series of further examples were prepared. Their compositions are outlined under Table II. These formulations provide good storage stability for the ascorbic acid and are aesthetically consumer acceptable.
TABLE II______________________________________ Example No. (Weight %)COMPONENT 2 3 4 5______________________________________Cyclomethicone 42.0 41.6 40.0 42.0Gransil SR CYL 18.0 17.9 17.3 18.0Propylene Glycol 16.8 14.8 17.5 15.0Polyethylene Glycol 200 11.0 13.7 13.5 13.5Ascorbic Acid 5.0 5.0 5.0 5.0Dimethyl Isosorbide 2.0 2.0 2.0 2.0Cetyl Dimethicone Copolyol 0.8 0.8 0.8 0.8Water balance balance balance balance______________________________________
EXAMPLES 6-12
These series of Examples illustrate the scope of the present invention. Various concentrations of ascorbic acid, cyclomethicone and siloxane elastomer are illustrated.
TABLE III______________________________________ Example No. (Weight %)COMPONENT 6 7 8 9 10 11 12______________________________________Cyclomethicone 36.0 36.0 36.0 40.0 40.0 45.0 32.0Gransil SR CYL 24.0 24.0 24.0 20.0 20.0 15.0 27.0Butylene Glycol 17.5 -- 17.5 -- -- -- 29.0Glycerin -- 17.5 -- -- -- -- --Polyethylene Glycol 10.0 -- -- 17.5 12.0 10.0 10.0200Polyethylene Glycol -- 10.0 10.0 10.0 12.0 10.0 --800Dimethyl Isosorbide 2.0 2.0 2.0 4.0 5.0 10.0 1.0Ascorbic Acid 1.0 1.0 1.0 4.0 4.0 5.0 0.5Cetyl Dimethicone 0.8 0.8 0.8 0.8 0.8 -- --CopolyolWater bal. bal. bal. bal. bal. bal. bal.______________________________________
The foregoing description and Examples illustrate selected embodiments of the present invention. In light thereof variations and modifications will be suggested to one skilled in the art, all of which are within the spirit and purview of this invention. | 4y
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FIELD OF THE INVENTION
[0001] The present invention relates generally to food preparation devices and, more particularly, to a peeling tool for peeling the skins of fruits and vegetables and for shaving fruits and vegetables.
BACKGROUND OF THE INVENTION
[0002] Various designs exist for handheld food peeling devices that include a handle and a blade whereby a user manually pushes the blade across a food product to slice the food product. While existing handheld food peeling devices are generally suitable for what is regarded as ordinary performance, there is room for improvement in terms of adaptability, such as peel thickness and peel type customization, flexibility, and safety.
SUMMARY OF THE INVENTION
[0003] It is an object of the present invention to provide a peeling tool for peeling food products having a mechanism for adjusting peel thickness, a selectively actuatable safety cover and a multi-blade peeling cartridge.
[0004] These and other objects are achieved by the present invention.
[0005] A peeling tool includes a main shaft, a handle affixed to a first portion of the main shaft, a nose rotatably coupled to a second portion of the main shaft, a blade assembly positioned intermediate the handle and the nose about the main shaft, the blade assembly including a first arcuate blade and a second arcuate blade defining a space therebetween for the passage of a slice of a food product, and a peel thickness adjustment mechanism, the peel thickness adjustment mechanism being actuatable to adjust a dimension of the space.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The present invention will be better understood from reading the following description of non-limiting embodiments, with reference to the attached drawings, wherein below:
[0007] FIG. 1 is a perspective view showing the front a peeling tool with a flat peeling blade exposed according to a first preferred embodiment of the present invention.
[0008] FIG. 2 is a perspective view showing the back of the peeling tool of FIG. 1 with a julienne peeling blade exposed.
[0009] FIG. 3 is a perspective view showing the front of the peeling tool of FIG. 1 with a sleeve in a safety position.
[0010] FIG. 4 is an exploded view of the peeling tool of FIG. 1 illustrating the physical components thereof.
[0011] FIG. 5-8 are various views of the flat blade portion of the blade assembly of the peeling tool of FIG. 1 .
[0012] FIGS. 9-13 are various views of the right, julienne blade portion of the blade assembly of the peeling tool of FIG. 1 .
[0013] FIGS. 14-15 illustrate the cutting of a food product with the julienne blade portion of the blade assembly of the peeling tool.
[0014] FIG. 16 is a top plan view of the blade assembly of the peeling tool illustrating the cutting of a food product with the flat blade portion of the blade assembly.
[0015] FIG. 17 is a longitudinal cross-sectional view of the peeling tool of FIG. 1 .
[0016] FIG. 18 is an enlarged, detail cross sectional view of a nose of the peeling tool of FIG. 1 .
[0017] FIG. 19 is a cross-sectional view of the peeling tool of FIG. 1 , taken along line A-A of FIG. 5 .
[0018] FIG. 20 is a perspective view of the peeling tool of FIG. 1 illustrating how a user adjusts the tool for peel thickness.
[0019] FIG. 21 is a side elevational view of a first and second locking mechanism of the peeling tool of FIG. 1 .
[0020] FIG. 22 is a reverse side elevational view of the first and second locking mechanism of the peeling tool.
[0021] FIGS. 23A-25B illustrate locking positions and blade positions corresponding to minimum, medium and maximum peel thickness.
[0022] FIGS. 26-28 are various views illustrating the structure of the second locking mechanism.
[0023] FIGS. 29-33 are various views illustrating the structure of the first locking mechanism.
[0024] FIGS. 34-35 are views illustrating the structure of a localizer for adjusting for peel thickness.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0025] Referring generally to FIGS. 1-4 , a peeling tool 10 according to a first preferred embodiment of the present invention comprises a main shaft 12 , a blade assembly 14 , a fixed holder or main handle 16 , an end cap 18 and a peel thickness adjustment mechanism 20 contained within a nose 22 . As shown in FIGS. 1-3 the main shaft 12 , holder 16 and blade assembly 14 define an elongated body of the peeling tool 10 . The main shaft 12 is preferably made of metal or other strong material suitable to withstand bending stress during use.
[0026] As best shown in FIG. 4 , the fixed holder 16 is a two part skin that is fixedly secured to, and encompasses, one end of the main shaft 12 . In the preferred embodiment, the fixed holder 16 is secured to the main shaft 12 via pins 24 . The nose 22 containing the peel thickness adjustment mechanism 20 is rotatably coupled to the other end of the main shaft 12 , and the blade assembly 14 is mounted about the main shaft 12 intermediate the fixed holder 16 and the nose 22 . As best shown in FIGS. 1-3 , a sleeve 26 is slidably mounted about the blade assembly 14 and fixed holder 16 intermediate the nose 22 and end cap 18 . As shown therein, the end cap 18 , nose 22 and sleeve 26 have an enlarged and substantially equal diameter as compared to the fixed holder 16 and cylindrical blade assembly 14 .
[0027] Importantly, as noted above, the sleeve 26 is slidable from a first position, as shown in FIGS. 1 and 2 , in which the sleeve 26 encompasses the fixed holder 16 and abuts the end cap 18 , to a second position, as shown in FIG. 3 , in which the sleeve 26 encompasses the blade assembly 14 and abuts the nose 22 . As will be readily appreciated, in the first position, the sleeve 26 functions as an ergonomic handle for gripping the peeling tool 10 during use. In the second position, the sleeve 26 encompasses the blade assembly 14 for safety and for protecting the blade assembly 14 when the tool 10 is not in use.
[0028] As further shown in FIG. 5 , the blade assembly 14 includes two separate blade portions, a flat blade portion 28 and a julienne blade portion 30 for making flat peel slices and julienne peel strips, respectively. FIGS. 5-8 show various views of the flat blade portion 28 . The flat blade portion 28 includes a right flat blade 32 integrally formed with two annular guides 34 at respective ends of the blade 32 . Alternatively, the right flat blade 32 may be spot welded to the annular guides 34 .
[0029] FIGS. 9-13 show various views of the julienne blade portion 30 . The julienne blade portion 30 includes a left flat blade 36 , to compliment the right flat blade 32 of the flat blade portion 28 , and a julienne blade 38 . The left flat blade 36 and julienne blade 38 are integrally formed with two annular guides 34 at respective ends of the blades. Alternatively, the left flat blade 36 and julienne blade 38 may be spot welded at 39 to the annular guides 34 .
[0030] In an assembled state, the flat blade portion 28 and julienne blade portion 30 are brought into registration with one another to form the generally cylindrical blade assembly 14 . As will be readily appreciated, the julienne blade 38 and flat blades 32 , 36 are oriented opposite one another on the blade assembly 14 such that a user simply rotates the peeling tool 10 within his or her hand to present the desired blade system to the food product to be peeled, as discussed in detail below and as shown in FIG. 16 . As discussed above, the blade assembly 14 is received on the main shaft 12 by inserting the shaft 12 through the annular guides 34 . Importantly, however, the flat blade portion 28 and julienne blade portion 30 are not affixed to one another, such that the flat blade portion 28 is capable of rotating slightly about the main shaft 12 independently of the julienne blade portion 30 to adjust for peel thickness, as discussed in detail below.
[0031] FIGS. 14 and 15 illustrate the cutting of a food product with the julienne blade 38 . Importantly, the julienne blade 38 can be used to cut from either side of the blade for right-handed and left-handed users. Referring now to FIG. 16 , a top plan view of the blade assembly 14 is shown. As discussed above, the blade assembly 14 includes three separate blades, a left flat blade 36 , a right flat blade 32 and a julienne blade 38 . FIG. 16 illustrates the cutting of a food product 40 with one of the flat blades 32 , 36 . In operation, the peel or a slice 41 of a food product 40 passes in between the space 42 between the left flat blade 36 and right flat blade 32 as the food product is peeled/sliced. Importantly, this space 42 may adjusted for peeling different thicknesses of skin, as discussed below.
[0032] Turning now to FIG. 17 , a longitudinal cross-section view of the peeling tool 10 is shown. As shown therein, a stopper 44 is fixedly secured to the metal shaft 12 and holds the blade assembly 14 in proper position for peeling. In particular, the stopper 44 prevents the blade assembly 14 from sliding too far down the shaft 12 towards the end cap 18 .
[0033] Referring to FIG. 18 , an enlarged, cross-section view of the nose 22 is shown. As shown therein, the nose 22 defines a housing and includes a release button 46 for activating the peel thickness adjustment mechanism 20 , as discussed in detail below, and a sharpened tip 48 for removing potato eyes or blemishes from food products. The nose 22 is rotatably coupled to the main shaft 12 and houses the peel thickness adjustment mechanism 20 . As shown in FIG. 18 , the nose 22 contains a spring 50 operatively connected to the nose 22 for rotatably biasing the nose 22 relative to the main shaft 12 , a first lock 52 , a second lock 54 , a localizer 56 and the release button 46 .
[0034] As shown in FIG. 19 , the blade assembly 14 is mounted on the main shaft 12 and is configured to swing about an angle C. Importantly, this swinging configuration of the blade assembly 14 ensures that the peeler 10 , and the blade assembly 14 in particular, is always in contact with the skin of various food products that may be oddly or irregularly shaped.
[0035] FIG. 20 illustrates how a user may adjust the peeler 10 for peeling different thicknesses of skin. As shown therein, a user pushes down on the release button 46 on the nose 22 to free the nose 22 . The nose 22 may then be rotated clockwise or counterclockwise to adjust the space 42 , i.e., the width between the left flat blade 36 and right flat blade 32 (this space 42 can best be seen in FIG. 16 ).
[0036] In particular, as shown in FIGS. 21 and 22 , when the button 46 is depressed and the nose 22 is rotated, a ramp 58 of the second lock 54 engages a correspondingly-shaped slot 60 in the first lock 52 to rotate the first lock 52 . This rotation of the first lock 52 causes the first lock 52 to move upwards, away from the blade assembly 14 , until teeth 62 on the first lock 52 disengage from the end of the flat blade portion 28 such that the flat blade portion 28 becomes loose and its position can be adjusted. This upwards movement also releases spring biased lock balls 64 from their seated position within the localizer 56 , which permits the localizer 56 to be rotated which, in turn, effects rotation of the flat blade portion 28 and right flat blade 32 , as discussed below. As will be readily appreciated, the position of the right flat blade 32 can be adjusted along an arcuate path as the flat blade portion 28 is rotated about the main shaft 12 . This upwards movement is shown in FIGS. 21 and 22 .
[0037] As noted above, the localizer 56 includes a plurality of recesses or detents 66 oriented about a circumference of the localizer 56 . In the preferred embodiment, the localizer 56 includes three such recesses or detents 66 corresponding to minimum, medium and maximum peel thickness. Upon rotation of the nose 22 , and thus rotation of the flat blade portion 28 , the button 46 may be released at a desired point to cause spring-urged lock balls 64 to be urged into one of the plurality of recesses 66 in the localizer 56 . This rotation adjusts the space 42 between the right flat blade 32 of the flat blade portion 28 and the left flat blade 36 of the julienne blade portion 30 . In particular, FIG. 23A shows the position of the lock ball 64 in the first recess, which corresponds to the minimum space, x, between the blades 32 , 36 , i.e., minimum peel thickness, as shown in FIG. 23B . FIG. 24A shows the position of the lock ball 64 in the third recess, which corresponds to maximum peel thickness, z, as shown in FIG. 24B . Finally, FIG. 25A shows the position of the lock ball 54 in the second recess, which corresponds to medium peel thickness, y, as shown in FIG. 25B .
[0038] Referring back to FIGS. 26-38 , the structure of the second lock 54 is shown in detail. As shown therein, the second lock 54 has a ramp 58 that engages the corresponding slot 60 in the first lock 52 to unlock the lock system. Moreover, referring to FIGS. 29-33 , the structure of the first lock 52 is shown in detail. As shown therein, the first lock 52 is generally cylindrical in shape and has a plurality of teeth 68 for matching the teeth of a holder 70 , which is secured to the main shaft 12 by a lock pin 71 , and the localizer 56 .
[0039] FIGS. 34 and 35 illustrate the structure of the localizer 56 . As shown therein, the localizer 56 is generally disc-shaped and has a plurality of teeth 72 for matching the teeth 72 for meshing with the teeth 68 of the first lock 52 . As discussed above, the localizer 56 is mounted about the main shaft 12 below the nose and above the blade assembly 14 , is partially rotatable about the shaft 12 , and includes a plurality of locating recesses 66 corresponding to different peel thicknesses.
[0040] As will be readily appreciated, the ability of the peeling tool 10 of the present invention to adjust for varying peel thickness is an important aspect of the present invention. In addition, the peeling tool of the present invention provides a level of safety heretofore unknown in the art by providing a sleeve that entirely covers the blade assembly when the peeling tool is not in use. Advantageously, this sleeve may also be retracted towards the end cap of the peeling tool to double as an ergonomic handle during use, as discussed above.
[0041] While the preferred embodiment of the present invention has been disclosed herein, it is understood that various modifications can be made without departing from the scope of the presently claimed invention. | 4y
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This application is a continuation of application Ser. No. 537,142, now abandoned, filed Sept. 29, 1983.
BACKGROUND OF THE INVENTION
This invention relates to stacking rings used to support periodic groups of fairing segments for towed marine systems for sonar, communication, mine sweeping and oceanographic exploration which are normally deployed into the sea and tethered to a moving vessel at speeds ranging from 0 to 50 knots. Quite often when velocities exceed 10 knots, it is necessary to add streamlined fairings to the entire length of tow cable in order to reduce cable strumming (cable vibration) and in order to increase system depth performance by reducing the cable drag.
Performance problems with fairings can occur due to fluid drag force components which act parallel to the cable axis. This axial force is cumulative and can create a force of several thousand pounds on the bottom fairing. Not only can this stacking force crush fairings at the bottom, but also it can cause jamming and distortion of the fairing shape which prevents the fairing from rotating freely in the flow, resulting in poor performance.
The solution to the problem is to fasten a suspension device which transfers the load to the cable at intervals (typically 5-10 feet) down the cable length, instead of allowing the force in each fairing to accumulate, and at the bottom of the cable, to jam the fairings.
Prior solutions have incorporated hard metallic rings which are installed either by compression techniques on pretensioned cables, or by welding the ring seam shut with clearance between the cable, and vulcanizing rubber between the ring and cable to form a bond. Generally the process requires various forms of welding, brazing, cable pretensioning, special tooling and individual testing because of the elasticity and compressibility of tow cables.
Metallic rings have numerous deficiencies: Hard nodes or rings produce concentrated regions of stress which reduce the fatigue life of the cable; metallic rings attached to the cable are larger than the cable and generally slightly larger than the fairing diameter, and passage of the ring through sheaves and winding on storage drums under tension can cause damage to the sheaves and drums; metallic rings are not field-installable or repairable; metallic rings corrode in the sea water/marine environment, and some forms actually accelerate corrosion of the cable itself; metallic rings present poor bearing surfaces for the fairing; metallic rings are relatively expensive; and metallic rings cannot readily adapt to cable diameter changes which occur as a result of cable tensioning and postforming of the cable during use.
SUMMARY OF THE INVENTION
A stacking ring of elastomeric material is formed by molding the elastomeric material around a cable which has been prepared with a bonding agent to provide a compliant ring capable of supporting substantial loading along the cable axis. Low-friction bearing surfaces may be incorporated in the ends of the ring which also increase the axial force retention capability of the ring.
It is the primary object of this invention to provide a stacking ring which does not have the deficiencies of the prior art rings. It is therefore an object to provide a durable, elastic, field-installable, inert, inexpensive and cable-adhering stacking ring.
It is a further object to provide a stacking ring which is easily adaptable to various cable and fairing constructions.
It is a feature of this invention that it is moldable at room temperature and atmospheric pressure.
The basic design of the stacking-ring makes it readily adaptable as a suspension device on tow cables for any application requiring attachment at intermediate points along the cable.
BRIEF DESCRIPTION OF THE DRAWINGS
The objects and features of this invention are explained in the following description taken in conjunction with the accompanying drawings, in which:
FIG. 1 is a isometric quarter-section view of the stacking ring of the invention;
FIG. 2 is an isometric view of the end bearing disk in the stacking ring of FIG. 1;
FIG. 3 is a plan view of a fairing segment with a cut-out section in which a stacking ring is positioned; and
FIG. 4 is a cross-sectional view of FIG. 3 along section line 4--4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The stacking ring 10 of this invention is basically a molded, synthetic elastomeric cylinder (e.g. urethane, silicone) which is formulated to cure at room temperature in a simple cavity mold at atmospheric pressure. In order to illustrate the details of the stacking ring more clearly, FIG. 1 shows the stacking ring 10 with a length approximately twice that actually utilized and a thickness about four times the actual thickness of the stacking ring relative to a cable diameter of 1" as shown in the quarter-section view of FIG. 1.
The stacking ring 10 consists of the elastomer 11, surface bonding agent 12 and end bearing discs 13. In an alternate embodiment of the invention the bearing discs 13 are not present. In another alternate embodiment of the stacking ring 10 the bearing disc may be of a material which is capable of being bonded to the elastomer 11, with the possible utilization of a bonding agent to improve the bond between the elastomer 11 and the disc 13. Bearing materials which are difficult to bond, such as disclosed in this preferred embodiment, will utilize mechanical linking of the elastomer 11 with the ring 13.
Functionally the stacking ring 10 of FIG. 1 performs the same general purpose as the prior art metallic stacking rings. That is, it prevents fairings from sliding axially along the cable 14 and its periodic placement along the length of the cable 14 prevents the accumulation of stacking forces on the bottom fairing which would otherwise be of such magnitude as to distort the fairing and prevent its free rotation about the cable as is necessary for proper operation. The stacking ring design of this invention represents a significant improvement over the prior art stacking ring design in that the problems applicable to metallic stacking rings presented earlier in this application have been overcome.
The stacking ring 10 is fabricated by priming that portion of the cable 14 to which the ring is to be bonded with an elastomer bonding agent. For a stainless steel cable 14 it was found that the commercially available epoxy primer, DEVOE 201, provided a satisfactory bond between the cable and the polyurethane elastomer. Two low friction bearing discs 13 shown in detail in FIG. 2 are snapped over the cable 14 by twisting open the disc 13 at its split line 131. If the disc 13 is not to be used, the previous step may be omitted. A conventional split mold (not shown) is secured around the cable 14 with the discs 13 within each end of the mold. The mold is so configured that whether or not the disc 13 is used there is a sufficiently tight seal at the ends of the mold to prevent the elastomer compound which is next injected into the mold from leaking out of the mold. A commercially available polyurethane elastomer, Conap EN-8, has been found to have the characteristic properties desirable in this application, namely bonding capability to the cable 14, elasticity, and sufficient strength to withstand the axial component of force provided by the fairings which it is restraining. The elastomer is allowed to cure. Cure times are typically three to seven days at normal ambient temperatures. As little as twelve hours are required if elevated temperatures are used.
The split bushings or bearing discs 13 in the end of each stacking ring 10 are designed to provide low friction surfaces for each fairing group or suspended device to rotate against while supporting the axial load. Free rotation is a necessary requirement for proper fairing performance. The bearing disc 13 has a T-shaped cross-section 132 with captivating holes 133 contained in the leg 134 of the "T". The hole 133 is encapsulated in the elastomer 11 as shown in FIG. 1. The holes 133 lock the bearing disc 13 in place and distribute the stacking load within the stacking ring 10 to increase the bearing capacity of ring 10 and to resist peeling of the ring from the cable.
A stacking ring having a 1.25 inch diameter and 1.75 inch length bonded to a 1" diameter cable 14 when tested in a laboratory tensile test had a capacity exceeding 800 to 1300 pounds and thus is easily capable of withstanding the maximum axial stress imposed upon a stacking ring 10 when spaced at 10-foot intervals thereby supporting twenty fairing segments each six inches in length such as shown in FIGS. 3 and 4. The elastomer material employed in the stacking ring 10 is noncorrosive and significantly softer than the cable 14, thus eliminating a source of fatigue stress in the cable. The compliance of the stacking ring 10 does not cause any damage to the sheaves, cable drum or other apparatus used to deploy the cable. The design and material selection of the stacking ring 10 allows field retrofit or repair at any point on the cable without expensive tooling and methods. The materials selected are inherently inexpensive. Because the stacking ring 10 is constructed of an elastomer material which is bonded to the cable, the ring 10 has the ability to adapt to cable diameter changes produced by changes in stress on the cable.
The use of low friction bearing discs or bushings 13 at the ends of the stacking ring is an additional novel feature. The material selected in a preferred embodiment of the invention for the low friction bushing 13 is DELRIN which has the attributes of being a low friction material which can be factory fabricated by injection molding prior to molding the stacking ring 10 and which has sufficient flexibility when slotted as by slot 131 of FIG. 2 to be twisted and slipped onto the cable 14. Since chemical bonding to DELRIN is difficult, the T-shaped disc 13 design of FIGS. 1 and 2 has locking holes 133 which allows the disc 13 to be mechanically locked to the elastomer 11 of stacking ring 10 to not only produce a low friction surface at the end of the stacking ring, but also to distribute the load produced by the stacked fairings within the molded ring.
Field installation and repair capabilities of the stacking ring of this invention contribute greatly to its desirability.
FIG. 3 illustrates how the stacking ring of this invention may be used with a particular form of fairing 30. However, the invention is not limited to being used with only this particular type of fairing, but may, for example, also be used with an appropriately modified or even unmodified fairing of the type described in U.S. Pat. No. 3,611,976 or other fairings.
Referring again to FIG. 3, there is shown a top plan view of a fairing 30. After the stacking ring 10 has been bonded to the cable 14, the fairing 30 tail halves 35, shown in cross-section in FIG. 3, are slipped over the cable and stacking ring. The fairing 30 has the central region of the nose portion 33 cut away in order to accommodate the stacking ring 10. The cutout portion 39 of the nose 33 of the fairing is only slightly larger than the corresponding dimensions of the stacking ring. The forward portion 37 of the nose 33 has the same radius as the stacking ring 10, but the rear portion 38 of the cutout has a slightly larger radius in order to provide clearance for rotation of the fairing about the ring while providing only small clearance in order to reduce turbulence effects. Although not preferred, the cutout 39 may alternatively be at the end of a fairing. If the increased drag and turbulence can be tolerated, then ring 10 may be placed between fairings without a cutout nose portion.
The fairing is held together with fasteners 31 and contains a flexible spring-steel clip 32 in the nose portion 33 of the fairing 30. The steel clip is in contact with the cable 14 and allows the fairing 30 to freely rotate around the cable. The links 34 attach the fairing 30 to its adjacent fairings. A sectional view along section line 4--4 of the fairing 30 is shown in FIG. 4. The fasteners 31 are seen to fasten together the two tail halves 35 of the fairing. The edges of the tail halves of the fairing are glued to a stiffener plate 36. The spring steel clips 32 are shown surrounding and of slightly larger diameter than the cable 14.
Having described a preferred embodiment of the invention, it will now be apparent to one of skill in the art that other embodiments incorporating its concept may be used. It is felt, therefore, that this invention should not be limited to the disclosed embodiment, but rather should be limited only by the spirit and scope of the appended claims. | 4y
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BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to a device for collection and storage of the free, non-active, portion of a strap of a manually operated cargo tightener which is used to secure cargo to be transported.
2. Description of the Related Art
The typical prior art cargo tightener, which is modified to make the present invention, includes a shaft provided at one end of a connecting link or arm. The shaft is journaled in one end of the connecting arm, thus providing for rotatable attachment of a lever to the connecting arm. A first, or short, strap is firmly secured to a bolt or pin in the other end of the connecting arm, and has at its free end, a hook or other device for attachment to a vehicle transporting the cargo.
A second strap has a hook or other device at one of its ends. The hook is attached to the transportation vehicle. The other end, or free or non-active, end of the second strap is inserted through a slot in the rotatable shaft. A ratchet arrangement permits tightening of the strap by back and forth movement of the lever with respect to the connecting link. Because the connecting arm or link is held firmly in place by the first strap, the second strap tightens down over the cargo. The cargo tightener is conventional and, therefore, will not be described in any great detail except with regard to the modification of the lever to provide the strap collector portion of the present invention.
A common problem when using the above mentioned cargo tightener with tensioning straps concerns the handling of the free end of the strap not used when securing the cargo. This strap portion has to be thoroughly secured to the cargo in order not to flutter in the encountering wind, or to trail on the ground, both cases leading to a hasty soiling and wearing down of the strap. Further, a freely fluttering strap is a danger to traffic, particularly in connection with the wider 24 to 30 foot long straps used professionally by haulage contractors.
Many attempts to solve these problems are known in the prior art. US Patent Publication No. US 2004/0094650 A1 to Huang, shows a strap fastener system including a strap fastener for fastening a belt, and a winding device for winding the strap. The winding device includes a housing which is attached to a connecting arm portion of the typical prior art cargo tightener. A reel is put in the housing for winding the strap, and a torque spring is arranged between the reel and the control device for automatically rotating the reel in the non-rotational position of the control device.
U.S. Pat. No. 5,611,520 to Söderström, shows a strap collector which is designed to be attached to the connecting arm of a standard cargo tightener. The strap collector includes a magazine for the protection and storage of the long tensioning strap of the cargo tightener when wound to the shaft of the strap collector.
U.S. Pat. No. 6,609,275 B1 to Lin, shows a strap tightener with an auto pulling device connected to a seat. The auto pulling device includes a housing and a reversing device. The reversing device is rotatably received in the housing. The housing would correspond to a connecting arm portion of a prior art cargo tightener.
U.S. Pat. No. 6,102,371 to Wyers, shows a strap tensioning and collection device having a variable length strap and a fixed length strap operatively associated with the strap storage section, and a strap tensioning section.
U.S. Pat. No. 4,622,721 to Smetz, et al. shows a device for connecting components to a belt.
German Offenlegungsschrift DE 36 39 712 A1 to Kinnert, shows a tensioning ratchet, in particular for belts, which is equipped with a ratchet body having a retaining bolt for fastening a safety belt, and having a ratchet lever which is mounted at the other end of the ratchet body so as to be rotatable about the axle of a slotted roller for fastening the end of a tensioning belt to be wound thereon.
All of the above devices perform generally satisfactorily, but share the problem of relatively high costs and difficulty of manufacture. In addition, they are rather bulky. Thus, those skilled in the art continued their search for a better cargo tightener and strap collector.
SUMMARY OF THE INVENTION
The aim of the present invention is to provide a cargo tightener and strap collector which is more cost effective compared with prior art devices, is less bulky, and is easier to manufacture. This is accomplished by having the strap collector on the lever portion of the cargo tightener, rather than on the connecting arm segment, as in the prior art. The advantages of this will become apparent by a careful reading of the detailed description, with appropriate reference to the accompanying drawings, wherein like numerals designate like parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is to be described in more detail below using exemplary embodiments.
FIG. 1 is a perspective view of a prior art cargo tightener.
FIG. 2 is a perspective view of a construction embodying the present invention.
FIG. 3 is an elevational view of the construction of FIG. 2 in its open position.
FIG. 4 is a perspective view of the construction of FIG. 2 in its closed position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 , there is shown a prior art cargo tightener and strap collector, generally designed by the numeral 10 . The cargo tightener and strap collector 10 comprises a connecting arm or link 12 , and a lever or arm 14 . A strap 15 is provided with a hook 16 at one end thereof for connection to a transportation vehicle (not shown). The other end of strap 15 is firmly held to connecting arm 12 by pin 17 . Reciprocal motion of lever 14 using handle 18 will cause shaft 19 to rotate due to the ratchet and pawl assembly 13 .
The present invention relates to a modification of the lever or arm 14 to solve the problems of the prior art. For purposes of understanding, new reference numerals are used when referring to the present invention.
Referring now to FIGS. 2-4 , the present invention relates to an improved cargo tightener and strap collector, generally designated by the numeral 20 . An improved apparatus for tightening and collecting a strap, or strap collector, or combination cargo tightener and strap collector 20 , includes a connecting arm or link 22 and a lever 24 . Connecting arm 22 extends in a longitudinal direction, and may be substantially similar to the connecting arm 12 shown in the prior art construction of FIG. 1 . It is a modification to the lever of the prior art construction, identified by the numeral 24 , which provides a novel cargo tightener and strap collector 20 . As with the prior art, there is provided a first shaft 26 journaled for rotation in one, or first, end 22 A of the connecting arm 22 . At the other, or second, end 22 B of the connecting arm 22 is provided a pin 23 , to which a first, or short, strap 25 is attached. A first hook or fastening means or fastening device 27 is attached to the other end of the strap 25 . In use, the hook 27 will be attached to the transportation vehicle on which the cargo being tightened is being transported.
As in the prior art devices, reciprocal rotation of the lever 24 will cause co-rotation of the first shaft 26 . Journals for first shaft 26 , as well as second shaft 40 , are provided by opposed apertures provided in a first pair of spaced apart sidewalls 36 provided in connecting arm 22 , and a second pair of spaced apart sidewalls 37 in the lever 24 . A second shaft 40 has provided therein second slot 42 ( FIG. 4 ) to accept a free end, i.e., the end without the second hook 54 , of a second belt 50 , as hereinafter described.
At least a first portion 40 A of shaft 40 may extend beyond at least one of the second pair of sidewalls 37 ( FIG. 2 ) so that a knob 44 may be attached thereto for rotation of the second shaft 40 . In the preferred embodiment, a first portion and a second portion ( 40 A, 40 B) of the second shaft 40 will extend beyond the second pair of spaced apart sidewalls 37 , and a knob 44 will be attached to each portion of the second shaft.
Reciprocal rotation of the lever 24 will cause co-rotational rotation of the first shaft 26 by virtue of a pair of ratchet wheels 60 which are mounted on the first shaft 26 between the first pair of sidewalls 36 and the second pair of spaced apart sidewalls 37 . It is preferred that two ratchet wheels 60 be used, although one may possibly be used. Pawl 61 aides in the rotation of the first shaft 26 by operating on the ratchet wheel 60 . The pawl 61 is spring loaded and slides in a pair of opposed slots 64 ( FIG. 4 ) in the second pair of opposed sidewalls 37 .
Second, or long, strap 50 is provided having second hook 54 provided at one end thereof. The free or non-active end of strap 50 , so referred to because it has no connection to second hook 54 , is first passed through first slot 32 and then inserted in second slot 42 ( FIG. 4 ). Second shaft 40 is then rotated, with the aid of knobs 44 , to roll up free end of strap 50 into a roll 52 .
In use, second hook 54 and second strap 50 are completely unrolled and removed from second shaft 40 . Second hook 54 is attached to the transportation vehicle on which the cargo is to be transported, at the appropriate location. The free end of the strap 50 is placed through first slot 32 in first shaft 26 , and the lever 24 is reciprocally rotated, causing co-rotational movement of the first shaft 26 . Since the first strap 50 is inserted in the first slot 32 , and the connecting arm 22 is restrained by the first strap 25 and the first hook 27 , the cargo tightener and strap collector 20 is tightened down on the cargo. At this point, the free end of the second strap 50 is inserted in the second slot 42 in the second shaft 40 and the knobs 44 are rotated to take up any slack in the strap before the cargo is transported.
Alternately, the free end of the strap of the second strap 50 may be left inserted in the second slot 42 in the second shaft 40 , and the second strap 50 along with second hook 54 may be pulled out, causing the roll 52 to unwind until the second hook 54 may be attached to the transportation vehicle in the appropriate spot. The lever 24 is then reciprocally rotated causing co-rotational movement of the first shaft 26 , and the tightening of the cargo tightener and strap collector 20 on the cargo (not shown) in the manner previously described. Any slack in the second strap 50 is taken up by rotating the knob or knobs 44 until the slack is removed.
In order to provide clearance for the roll 52 so that it does not strike the cargo being transported, the lever 24 is provided with a first substantially linearly extending portion 70 , and a second linearly extending portion 71 extending at an angle with respect to the first portion 70 , thus elevating the roll 52 away from the cargo by elevating the second shaft 40 away from the cargo.
If it is desired to have the linearly and angularly extending portions 71 of the second pair of sidewalls 37 be further apart proximate the roll 52 , a pair of diverging portions 72 of the second pair of sidewalls 37 may be interposed between the first linearly extending portion 70 and the second linearly and angularly extending portion 71 of each of said second pair of sidewalls 37 .
Thus, by carefully considering the problems in the prior art devices, we have provided a novel cargo tightener and strap collector which is simpler in construction, easier to manufacturer and less costly than prior art devices. | 4y
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REFERENCE TO RELATED APPLICATIONS
[0001] This application is a national stage application under 35 USC 371 of International Application No. PCT/EP2008/007246, filed Sep. 4, 2008, which claims the priority of German Patent Application No. 10 2007 044 601.4, filed Sep. 19, 2007, the contents of which prior applications are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The invention relates to a wind farm having at least one wind energy installation, which each have a generator and a converter, and having a farm master which is designed for real power and wattless-component monitoring and transmits a control signal for the wattless component via a communication network to the wind energy installations, and having a connection grid system which connects the wind energy installations to one another in order to feed electrical power into a grid system via a junction point.
BACKGROUND OF THE INVENTION
[0003] The behavior of wind farms when connected to the electrical grid system is becoming increasingly important for operation of wind farms. Because of the increasing number and size of the wind farms, they can and must make their contribution to ensuring the stability of the grid system. The important factors from the point of view of the grid system operators are not only the compensated feeding of real power, but there are additionally also requirements relating to the feeding of wattless component, in order to make it possible to comply with specific tolerance limits for the emitted voltage. The latter is particularly important in the case of wind farms which are connected to the medium-voltage grid system. This is because, in these grid systems, changes in the voltage level of individual points, such as the feed point of a large wind farm, due to the network structure, can lead to influences on the primary routes and directions in which the electrical power flows. It is also known for it to be highly important to feed in wattless components in order to support the voltage level. This is the case in particular in the event of a voltage dip.
[0004] The capability of wind farms with modern wind energy installations fitted with converters to feed both real power and a wattless component is therefore of major importance. One requirement is that specific nominal-value requirements must be complied with for the wattless component (irrespective of whether this relates to a direct requirement for the wattless component or the power factor), and frequently for the nominal voltage as well, with respect to a junction point between the wind farm and the grid system. The farm master uses these nominal value requirements to determine appropriate control signals for the individual wind energy installations in the wind farm. In doing so, it is necessary to remember that the wind energy installations in a wind farm do not necessarily all need to be identical, and that, particularly in spatially extended wind farms, they are frequently also connected via long lines with different capacitance and resistance characteristics. In order to counteract the delay effect associated with this, attempts have been made to transmit requirements for the voltage to be emitted by the wind energy installations, rather than wattless-component nominal values, to the wind energy installations, in which case the wind energy installations regulate this in accordance with the requirement by means of a local voltage regulator (DE-A-102004048339). This concept offers the advantage of rapid transmission, even when the transmission speed in the communication network is limited. However, it has disadvantageously been found that implementation can be difficult, particularly in the case of wind farms having wind energy installations of a different type or from different manufacturers. This applies in particular to retrofitting. It is also known for a dedicated wattless-component nominal value to be preset for each of the individual wind energy installations (WO-A-01/73518). One disadvantage of this concept is that, when the wattless component (or the power factor or the angle) of the individual wind energy installations is preset directly by the farm master, the limited transmission speeds in the communication network for the wind farm can result in delays, leading to delayed readjustment and thus to a poor response to rapid changes.
SUMMARY OF THE INVENTION
[0005] In the light of the last-mentioned prior art, the invention is based on the object of providing an improved power-factor management which achieves a better dynamic response and therefore more stability in the grid system.
[0006] The inventive solution lies in the features broadly disclosed herein. Advantageous embodiments are specified in the detailed disclosure.
[0007] In the case of a method for operation of a wind farm having at least two wind energy installations, which has a generator with a converter for production of electrical power and has a controller, having a farm master which is designed for real-power and wattless-component monitoring, and trans-mits a control signal for the wattless component via a communication network to the wind energy installations, and having a connection grid system which connects the wind energy installations to one another in order to feed the electrical power produced into a grid system via a junction point, wherein the wattless component is regulated at least one of the wind energy installations by means of a power-factor regulator to whose input a wattless-component nominal value is applied and which acts on the converter in order to set a wattless component, there is provided, according to the invention, application of a signal to the at least one wind energy installation, and regulation of the emitted voltage by varying the wattless component emitted from the converter at the nominal voltage by means of an additional regulator, and furthermore linking of the power-factor regulator and the additional regulator such that a common control signal is formed for the converter.
[0008] The expression real-power or wattless regulator should be understood in a wide sense, and in addition to real power regulation devices it also covers current regulation devices which appropriately regulate the real component and the reactive component of the current, and therefore also the emitted power. It is therefore irrelevant to the invention whether the current or the power, or both in a mixed form, is or are used to regulate the real component and the reactive component.
[0009] The combination, as provided according to the invention, of a dedicated power-factor regulator in the wind energy installation and local voltage regulation achieves a better response of the wind energy installations in the wind farm, to be precise particularly with respect to the dynamic response to changes. This improvement allows faster regulation in the wind farm and makes it possible to avoid oscillations, such as those which, conventionally, have occurred frequently in the case of wind farms with different types of wind energy installations. In this case, the response can be influenced in a simple manner (in general by a simple software change) by the choice of the way in which the powerfactor regulation and the additional regulation are linked. The interaction according to the invention of the powerfactor regulator and the additional regulator by linking them therefore results in a rapid dynamic response, that is to say a fast reaction to voltage changes, and good stability, that is to say steady-state accuracy without the risk of regulation oscillations. For finer tuning, it is possible to provide for the power-factor regulation to have the dominant influence in the linking process. This reinforces the damping influence on regulation oscillations between the wind energy installations, as a result of which these virtually disappear. In contrast, if the additional regulation of the voltage is dominant in the linking process, then a faster response can be achieved when the voltage changes occur.
[0010] The interaction according to the invention will be explained in the following text using the example of a voltage dip. The voltage reduction in the grid system is identified virtually at the same time by the farm master and the control system for the individual wind energy installations. The farm master uses its wattless-component monitoring unit to calculate a new wattless-component nominal value on the basis of the changed voltage value. Because of the signal delay, which unavoidably occurs because of the limited bandwidth, in the transmission of the changed nominal value to the wind energy installations (this value is in practice several hundred milliseconds), the changed nominal values arrive at the powerfactor regulator for the wind energy installations with a considerable delay. Since the additional regulator in the wind energy installation likewise identifies the voltage dip, there is no need to wait for the delayed transmission of new nominal values, and instead the required change in the wattless-component output can be anticipated at this stage. When the new nominal values arrive from the farm master, the linking process according to the invention to the power-factor regulator ensures that sufficient steady-state accuracy is achieved. In this case, the wattless-component monitoring unit that is implemented in the farm master adapts the nominal requirements for the wind energy installations such that the total wattless component being produced by the farm at that time matches the nominal requirement. This process can be carried out slowly and therefore with high steady-state accuracy, since the wind energy installations in which the additional regulator and the power-factor regulator are linked can autonomously anticipate the required reaction.
[0011] Furthermore, in addition to the rapid regulation of the control differences while at the same time avoiding control oscillations, the method according to the inventionallows flexible matching to the requirements of different grid system operators. For example, the method can easily be implemented in such a way that, rather than presetting a wattless component for the wind farm as an entity, a nominal voltage for the wind farm can be used as an entity for control purposes. Furthermore, the method according to the invention offers the advantage that it can be implemented with comparatively minor modifications in software-based control systems and farm masters. Only a small amount of additional hardware complexity is required.
[0012] The signals of the power-factor regulator and of the additional regulator can be linked by means of variable weighting factors. This makes it possible to influence the interaction between the additional regulator and the powerfactor regulator. Various operating methods are possible. For example, it is possible for the farm master to preset not only the signal for the nominal voltage for the additional regulator but also for the wattless-component nominal value for the power-factor regulator. This allows very flexible overall optimization of the response of the wind energy installations in the wind farm, and therefore of the wind farm with respect to the grid system. However, for simplicity, it is also possible to provide for one of the two nominal values to in each case be set at the wind energy installation, and for the other to in each case be preset dynamically by the farm master. For example, if provision is made for the wattless-component nominal value to be constant, the farm master passes the signal for the nominal voltage to the additional regulator for the wind energy installation. This allows very rapid voltage regulation and therefore achieves effective stabilization of the grid-system voltage. Furthermore, this makes it possible to avoid undesirable excessive voltage increases by individual wind energy installations. This therefore allows the losses in the wind farm to be optimized overall. In this case, there is no need to preset a fixed wattless component for all of the wind energy installations, but expediently only for some of the wind energy installations in the farm. However, alternatively, it is also possible to provide a fixed setting for the nominal voltage at the wind energy installations, while the wattless-component nominal value is preset dynamically by the farm master. This also allows sufficiently rapid reaction to voltage changes, to be precise in particular also in conjunction with wind energy installations in the wind farm which do not have local voltage regulation. This method according to the invention can therefore be carried out very flexibly in various ways. Furthermore, it is robust to wind farms with wind energy installations of different types, which do not have specific functionalities, such as voltage regulation, or have different additional functionalities, such as additional passive compensation. The method according to the invention can therefore be used successfully even in those wind farms which have wind energy installations for which it is not possible to preset either the nominal voltage or the wattless component. The method according to the invention is therefore even suitable for wind farms which cannot be included in the regulation process because of a widely extended connection grid system or difficulties in the communication network of individual installations.
[0013] In one proven embodiment, the linking is carried out by varying the wattless component in the wind energy installation linearly with the voltage, provided that the voltage is within a voltage tolerance band. Provision is preferably also made for the wattless component to be varied non-linearly outside the limits of the tolerance band, for example by means of a kink in a characteristic at the limits of the tolerance band. This therefore allows the response of the method according to the invention to be varied within and outside the tolerance band, between the wattless-component preset on the one hand and the voltage regulation on the other hand.
[0014] In this case, the linking process is influenced predominantly by the additional regulator, and the wattless component of the wind energy installation will follow a voltage change, corresponding to the characteristics of the additional regulator. In this case, the additional regulator may be not only a proportional regulator but may also have integral and/or differential components.
[0015] The linking process can advantageously be carried out by input filtering of the input variable for the power-factor regulator or the additional regulator. In particular, it is possible to connect the additional regulator upstream of the power-factor regulator, as a result of which an output signal from the voltage regulator is applied as one of the input signals to the power-factor regulator. This makes it possible to achieve a clear regulator structure. This structure allows non-linear input filtering, for example by means of a characteristic element as an input filter.
[0016] In order to improve the overall voltage stability of the wind farm, the voltage emitted from the wind farm can be regulated at a nominal value by means of a voltage control module which acts on the wattless-component monitoring unit of the farm master. A nominal value for the nominal voltage of the farm is applied as an input thereto, and its output signal is applied as an input signal to the wattlesscomponent monitoring unit. This makes it possible to base the operation of the wind farm on a voltage nominal value (preset by the grid system operator) rather than wattless-component nominal values. A reactive-current compensator can advantageously be used as a voltage control module and, in the simplest case, may be in the form of a characteristic element. Provision is preferably also made for a pilot control signal for the nominal voltage to be produced as a function of the actual voltage at the wind farm in order to compensate for the voltage changes produced by the additional regulators for the wind energy installations. This makes it possible to use the pilot control to largely compensate in the farm master for the risk of overshoots when the grid system voltage changes because of the influence of the local voltage regulation of the wind energy installation. The fundamental idea is simply to correct the wattless-component nominal values transmitted to the wind energy installations by the contribution to be expected from the local voltage regulation. This therefore considerably improves the dynamic response to voltage changes, in particular voltage dips.
[0017] An emergency controller is preferably used in the control system for the wind energy installation, which is designed to provide a preferably stored substitute value for the power-factor regulator when there is no signal for the wattless-component nominal value. This makes it possible to maintain a certain amount of power-factor regulation in the wind energy installation, even in the event of failure of the communication, for example as a result of a fault in the communication network, to be precise at a standard value stored in advance.
[0018] The invention relates to a wind energy installation which has a generator with a converter for production of electrical power, and has a controller with a connection for a communication network, via which a control signal for the wattless component is applied to the wind energy installation, and has an additional regulator to whose input a signal for a nominal voltage is applied and which emits control signals for the converter in order to vary the emitted wattless component, in order to regulate the emitted voltage from the wind energy installation at the nominal value, wherein, according to the invention, the wind energy installation has a power-factor regulator to whose input a wattless-component nominal value is applied, and which acts on the converter in order to set a wattless component which corresponds to the wattless-component nominal value, and wherein a logic unit is provided which connects the power-factor regulator and the additional regulator to one another such that a common control signal is formed for the converter.
[0019] The invention furthermore relates to a wind farm having at least two wind energy installations, which have a generator with a converter for production of electrical power and has a controller, having a farm master which is designed for real-power and wattless-component monitoring, and trans-mits a control signal for the wattless component via a communication network to the wind energy installations, and having a connection grid system which connects the wind energy installations to one another in order to feed the electrical power produced into a grid system via a junction point, wherein at least one of the wind energy installations has a power-factor regulator to whose input a wattless-component nominal value is applied and which acts on the converter in order to set a wattless component which corresponds to the wattless-component nominal value, wherein, according to the invention, the wind energy installation has an additional regulator to whose input a signal for a nominal voltage is applied, and which emits control signals for the converter in order to vary the emitted wattless component, in order to regulate the emitted voltage from the wind energy installation at the nominal value, wherein a logic unit is provided, which connects the power-factor regulator and the additional regulator to one another such that a common control signal is formed for the converter.
[0020] For a more detailed explanation, reference is made to the above statements relating to the method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention will be explained in more detail in the following text with reference to the attached drawings, which illustrate advantageous exemplary embodiments, and in which:
[0022] FIG. 1 : shows a schematic view of one exemplary embodiment of a wind farm according to the invention, having a farm master and wind energy installations;
[0023] FIG. 2 : shows one example of a request relating to the response of the wind farm to the grid system;
[0024] FIG. 3 : shows a schematic illustration of a farm master according to a first exemplary embodiment of the invention;
[0025] FIG. 4 : shows a schematic illustration of a wind energy installation according to a first exemplary embodiment of the invention;
[0026] FIG. 5 shows illustrations of alternative characteristics for the exemplary embodiment shown in FIG. 4 ;
[0027] FIG. 6 : shows a schematic illustration of a farm master according to a second exemplary embodiment of the invention; and
[0028] FIG. 7 : shows a schematic illustration of a wind energy installation according to a second exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0029] According to one embodiment of the invention, a wind farm comprises a plurality of wind energy installations 1 (by way of example, FIG. 1 shows five wind energy installations), a connection grid system 3 to which the wind energy installations 1 are connected and which is connected via a junction point 69 to a medium-voltage grid system 9 , a farm master 8 for central control of the wind farm and a communication network 7 , which connects the farm master 8 to the individual wind energy installations 1 .
[0030] The individual wind energy installations 1 have a tower 11 at whose upper end a machine house 12 is arranged such that it can rotate in the azimuth direction. On its front end face, a rotor 13 is attached such that it can rotate to a rotor shaft (not illustrated), via which the rotor 13 drives a generator 15 in the machine house 12 . This is preferably a double-fed asynchronous generator, although other types are also possible. A converter 17 is connected to the generator 15 and converts the electrical power at a variable frequency, as produced by the generator, to a threephase current at a fixed frequency (grid system frequency). The wind energy installation 1 is monitored by a controller 2 , which acts on the individual components of the wind energy installation 1 via suitable control lines (not illustrated). The communication network 7 is connected to the controller 2 .
[0031] The farm master 8 is provided to monitor the electrical power fed into the grid system 9 and carries out a control function for the wind energy installations 1 . The electrical power produced by the wind energy installations 1 is fed into the distribution grid system 3 and is passed via this to a connection line 6 , via which it is passed to the junction point 69 and further into the grid system 9 . The connection line 6 may have a considerable length and may therefore have resistances, inductances and capacitances which are not negligible. These are illustrated symbolically in FIG. 1 as concentrated elements 60 along the connection line 6 . The connection line 6 has a medium-voltage trans-former 66 which is designed to increase the voltage level in the distribution grid system 3 from about 1000 volts to the voltage level of the medium-voltage grid system 9 of about 20 kV. Furthermore, pick-ups for voltage and current 68 , 68 ′ are arranged along the connection line 6 , and their measurement signals are connected to the farm master 8 .
[0032] In addition to inputs of the voltage and current measurement signals mentioned above, relating to the power fed from the wind farm into the grid system 9 , the farm master 8 has inputs for the maximum real power P-MAX that can be fed in and for a preset wattless component for the power to be fed in. The term “wattless-component preset” should be understood in a general form and, in addition to a wattlesscomponent value Qv includes the power factor cos φ, tan φ, the angle φ itself or else a preset voltage Uv. The farm master 8 has a real-power branch with a subtraction element 83 and a real-power monitoring unit 85 ( FIG. 3 ). The input signal, which is supplied from the outside, for a maximum real power is applied to a positive input of the subtraction element 83 . An output signal from a real-power calculation unit 87 is applied to the other, negative input of the subtraction element 83 , and the measurement signals determined by the current and voltage pick-ups 68 , 68 ′ are connected to the real-power calculation unit 87 as input signals. The real-power calculation unit 87 determines the real power actually emitted from the wind farm, and this is compared by the subtraction element 83 with the intended maximum power P-Max, and the difference resulting from this is applied as an input signal to the real-power monitoring unit 85 . A limit function is implemented in the real-power monitoring unit 85 and emits a real-power limiting signal P max to the wind energy installations 1 in the wind farm if the actually emitted real power exceeds the intended maximum power.
[0033] The farm master 8 furthermore has a wattless-component branch with a subtraction element 84 and a wattless-component monitoring unit 88 . An external nominal signal for the wattless-component preset Qv is applied to a first, positive input of the subtraction element 84 . A wattless-component calculation unit 89 is connected to the negative input of the subtraction element 84 and uses the voltage and current measurement signals determined by the measurement pick-ups 68 , 68 ′ to calculate the value of the wattless component Q actually emitted from the wind farm. The subtraction element 84 determines the difference between the wattless component actually fed in and the applied preset value, and supplies the difference, after limiting by a limiting module 86 , to the wattless-component monitoring unit 88 . This is designed to use the difference between the emitted wattless component and the intended nominal value to in each case produce updated control signals for the individual wind energy installations 1 in the wind farm, to be precise for their controllers 2 . These control signals are used to vary the nominal operating point of the wind energy installations 1 such that any differences between the wattless power emitted from the wind farm and the preset value are regulated out. It should be noted that direct presetting of the nominal wattless component Qv is only one of a number of possibilities for regulating the wattless component. The process of presetting a nominal voltage is illustrated by way of example in FIG. 2 . The conversion module 82 is in the form of a reactive-current compensator module in which a characteristic function is stored for determining a wattless-component preset Qv as a function of the preset voltage. This is preferably stored in the form of a look-up table.
[0034] The design and operation of the controller 2 for a wind energy installation 1 will be explained with reference to the exemplary embodiment illustrated in FIG. 4 . The main components of the controller 2 are a real-power regulator 25 and a power-factor regulator 24 . A subtraction element 23 is connected to the input of the real-power regulator 25 . The maximum level P-MAX, as determined by the farm master, for the real power of the respective wind energy installation is applied to the positive input of the subtraction element 23 , and a measure of the real power actually emitted by the wind energy installation 1 , as determined by a calculation unit 27 , is applied to the negative input. This determines (in a manner corresponding to the calculation unit 87 in the farm master) the actually emitted real power on the basis of measurement signals which are measured by voltage and current sensors (not illustrated) on the connecting line of the wind energy installation 1 to the connection grid system 3 . The subtraction element 23 uses the difference to determine any discrepancy, which is used as an input signal for the realpower regulator. The real-power regulator 25 uses a control algorithm which is known per se to determine a control signal for the wind energy installation, and this is supplied to a decoupling and limiting module 29 .
[0035] The power-factor regulator 24 has a similar structure to that of the real-power regulator 25 , and a subtraction element 22 is connected to its input. This subtraction element 22 forms the difference between the applied signals for a nominal wattless component qs, as determined by the wattless-component monitoring unit 88 in the farm master 8 , and the actually emitted wattless component of the wind energy installation, as calculated by means of a wattless-component calculation unit 28 . The difference between these forms a wattless-component discrepancy, which is applied as an input signal to the power-factor regulator 24 . From this, this uses a control algorithm that is known per se to determine a control signal for the wind energy installation 1 , which is likewise applied to the decoupling and limiting module 29 . This is designed to use the control signals from the realpower regulator 25 and the power-factor regulator 24 to generate common reference signals for the converter 17 in the wind energy installation 1 . These signals are applied as a reference vector F to the converter 17 and possibly also to the generator 15 in the wind energy installation.
[0036] The controller 2 designed according to the invention furthermore has an additional regulator 4 , which has a subtraction element 41 at its input, and a control core 43 . A measure for a nominal value of the voltage emitted by the wind energy installation 1 is applied to a positive input of the subtraction element 41 ; the measure of the actually emitted voltage, as determined by the voltage measurement device 19 , is applied to the other, negative input of the subtraction element 41 . The voltage difference which results in this case is applied as an input signal to the control core 43 of the additional regulator 4 . This is designed to use the voltage difference to determine correction signals for the input of the power-factor regulator 24 . In the illustrated exemplary embodiment, the control core 43 for this purpose has a switchable characteristic element 44 , which has a family of different characteristics (two in the illustrated example) implemented in it, as well as a multiplication element 45 . The choice between the characteristics can be made as required from the outside, by the farm master 8 or if required also automatically by the controller 2 of the wind energy installation 1 .
[0037] Reference is made to FIG. 5 , which shows the family of two characteristics. The characteristic represented by means of a solid line will be explained first of all. This is subdivided into a plurality of sections: a first branch for a voltage difference of more than 10% of the rated voltage, an upper branch for a difference of more than +10% of the rated voltage, and a main area in the voltage band in between. The characteristic gradient in the main area is chosen such that a voltage difference of +10% or −10% results in a correction value for the reactive current to be fed in of +16% and −16%, respectively, of the rated current. A somewhat higher gradient of the characteristic is chosen in the lower branch, for which the nominal value for the reactive current changes by about 20% of the rated value for every 10% further voltage difference. In contrast, a very high gradient of the characteristic is implemented for protection against overvoltage in the upper branch of the characteristic, such that even a voltage difference of +15% results in the maximum possible reactive current (that is to say the rated current) being emitted. A nominal value for the wattless component is calculated from the reactive current determined in this way, by multiplication by the voltage, in the multiplication element 45 . A characteristic such as this allows a good control rate to be achieved, which is particularly suitable for improving the response of the wind farm in its entirety with regard to the wattless-component preset, when voltage changes occur.
[0038] These characteristics are particularly suitable for damping control oscillations between the wind energy installations in a wind farm with a wattless-component preset to the individual wind energy installations.
[0039] An alternative characteristic is represented by dashed lines in FIG. 5 . This is subdivided into five sections: a lower branch, a lower plateau, a main area, an upper plateau and an upper branch. The main area extends over a narrower range than in the case of the characteristic explained first of all, specifically in a range from −5% to +5% of the nominal voltage. The gradient of the linear characteristic is considerably greater than in the case of the first variant, so that even a difference of 5% results in a 30% change in the magnitude of the reactive current. This value of 30% for the reactive current is also maintained in the subsequent plateau area of the characteristic, which extends from 5% to 10% difference, both in the case of undervoltage and in the case of overvoltage. This is followed for lower voltage by the lower branch of the characteristic, which has a gradient corresponding to the first variant, that is to say a change of about 20% in the reactive current for every 10% voltage difference. The upper branch once again has a considerably greater gradient, as a result of which, starting from a reactive current of 30% for an overvoltage of just 10%, the maximum reactive current (rated current) is reached at an overvoltage of +15%. The voltage regulation element is dominant in this characteristic. This is advantageous when particularly rapid voltage regulation is desirable in the wind farm, in order to reliably preclude negative effects of voltage changes.
[0040] According to a further aspect of the invention, the gradient of the characteristic in the main area can be chosen such that it corresponds to the characteristic gradient of the reactive-current compensation implemented in the farm master 8 . This is achieved in that, when voltage changes occur, the individual wind energy installations can react autonomously and quickly to the voltage change by means of the additional regulator 4 by feeding in wattless component, while at the same time, in the course of the greater reaction time of the farm master 8 , which is lengthened in particular by the communication time via the communication network 7 , corrected nominal values for the individual wind energy installations are calculated by means of the reactive-current compensation of the farm master, as a result of which the local additional regulators 4 for the wind energy installations 1 are returned to their initial value again. A plurality of iteration cycles of the farm master 8 may be required for this purpose before a steady-state accuracy is achieved. However, this is not disturbing since the additional regulator 4 provided at the wind energy installations 1 ensures a rapid reaction and therefore a good dynamic response, overall.
[0041] As a result of such linking of the compensation in the farm master 8 to the additional regulator 4 , the invention therefore achieves a considerable improvement in the response of the wind farm with respect to the wattless component in the event of voltage changes within and outside the intended tolerance band.
[0042] The additional regulator 4 and the power-factor regulator 24 are linked to one another by being connected in series. In this case, the additional regulator 4 acts as an input filter for the power-factor regulator 24 , which uses its own reference variable (wattless-component nominal value) and the actuating signal of the additional regulator 4 to calculate a common output signal, which is transmitted with the reference factor to the wind energy installations 1 . A logic unit 5 is therefore formed by the structure with the additional regulator 4 , the subtraction element 22 , the powerfactor regulator 24 and feedback via the voltage pick-up 19 and subtraction element 41 .
[0043] The wind energy installations 1 can in this case be operated in various ways. For example, in a first operating mode, as described above, both the nominal wattless component and the voltage of the individual wind energy installations 1 can be preset by the farm master 8 . This is the fully linked operating mode and allows very flexible optimization of the response of the wind energy installations 1 in the wind farm and, in consequence, optimization of the response of the wind farm overall with respect to the grid system 9 . Furthermore, presetting a nominal wattless component for the individual wind energy installations 1 offers the capability to also include any passive compensation devices which may be present there in the closed-loop control process.—For simplicity, however, other operating responses with restricted linking may also be provided. For example, in a second operating mode, the nominal voltage is still preset by the farm master 8 , while a nominal wattless component is set at the wind energy installations. This operating mode offers the advantage of very rapid voltage regulation in order in this way to stabilize the emitted voltage and therefore, in the end, the voltage emitted overall from the wind farm to the grid system 9 , as well. Furthermore, this allows optimization of the losses in the wind farm and makes it possible to avoid undesirable excessive voltage levels at individual wind energy installations 1 , in particular those which are located at the end of long connecting lines in the connection grid system 3 . In a wind farm having a plurality of wind energy installations, it is expedient for only some of the wind energy installations to have a constant wattless-component nominal value preset.—An alternative third operating mode is for the farm master 8 to preset the emitted nominal wattless component, while the nominal value for the emitted voltage is constant. An operating mode such as this may be expedient in wind farms which also have wind energy installations without local voltage regulation. This operating mode can therefore be used in particular for retrofitting.—Finally a fourth operating mode is also possible, in which both the nominal voltage and the wattless component are set at fixed nominal values. This also makes it possible to include wind energy installations 1 which are located at highly unfavorable points (long connecting lines and difficult connection via the communication network 7 ). The invention therefore offers the flexibility to be introduced into the overall control concept for the wind farm well even for highly problematic wind energy installations. In a situation such as this, the controller 2 can preferably be designed such that either the preset wattless component or the preset nominal voltage has priority. In the situation mentioned first, it is expedient to implement slow regulation in the controller 2 , which internally slowly readjusts the wattless-component nominal value such that the additional regulator is returned to its initial value again when voltage changes occur.
[0044] FIG. 6 illustrates a second embodiment of the farm master which differs from the first embodiment illustrated in FIG. 2 essentially by the provision of an additional compensation module 80 for the voltage. A measured value for the voltage, as determined by means of the voltage pick-up 68 , of the electrical power emitted by the wind farm into the grid system 9 is applied to one input of the compensation module 80 . An output signal from the compensation module 80 is applied as a further negative input to the subtraction element 84 in the farm master 8 . The compensation module 80 has a Dcharacteristic and is designed, as pilot control, to determine a compensation value in the event of voltage changes, which compensation value corresponds approximately to the influence of the reactive-current compensator in the farm master 8 . The nominal wattless-component value transmitted to the individual wind energy installations 1 can therefore at this stage be corrected by the contribution of the local additional regulator 4 . This considerably counteracts the risk of overshoots in the event of sudden voltage changes.
[0045] In the second exemplary embodiment of the wind energy installation, as illustrated in FIG. 7 , an emergency control module 21 is provided in the controller 2 , and is designed to provide a substitute value when there is no signal for the nominal wattless component. For this purpose, the output of the emergency control module 21 is applied to the subtraction element 22 . In order to allow regulation by means of the emergency control module 21 , it is preceded by a subtraction element 20 which determines the difference between the nominal wattless component, as determined by the farm master 8 , and the nominal wattless component actually fed in, and applies this as an input signal to the emergency control module. Even if the communication network 7 fails, wattlesscomponent regulation can therefore be carried out at the wind energy installation 1 . Regulation is in this case carried out optionally at a stored standard value or at a mean value of the most recently transmitted nominal wattless-component values. The additional regulator 4 is preferably still active, for additional assistance. | 4y
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a gas injector for injecting gaseous fuel with the aid of a dual valve needle.
[0003] 2. Description of the Related Art
[0004] Apart from liquid fuels, gaseous fuels, such as natural gas or hydrogen, have lately also been used for operating vehicles to an increasing extent. However, the known injectors are only conditionally suitable for these gaseous fuels, since gaseous fuels have different energy densities and volumes than liquid fuels. To ensure that internal combustion engines operated on the basis of such fuels have no excessive consumption and expel only a minimum of pollutants, it is necessary to inject the most exact gas quantities possible during each injection process. One or more injection process(es) per combustion cycle must also be possible in this context. Apart from the necessity of injecting a certain maximum quantity within a predefined period of time, there must also be the possibility of metering defined minimal gas quantities in a precise manner. A low system pressure should prevail during the process, so that a content of a gas tank can be utilized to the fullest extent possible. Furthermore, between the injection processes, the injector has to seal the gas from the combustion chamber. FIG. 1 schematically illustrates an example of the nozzle-side end of a known gas injector 1 , in which an outwardly opening valve needle 3 sits on a valve seat 2 in a housing 5 . FIG. 1 shows the closed state of the injector. When this injector is opened, an effective overall opening cross-section initially becomes linearly larger across the lift, as long as a released annular cross-sectional area at the valve needle constitutes the smallest cross-section. As soon as the annular gap between valve needle 3 having radius R 1 and housing 5 has a smaller cross-sectional area than the cross-sectional area between valve seat 2 and housing 5 released by the lift, a blow-in injection rate is constant.
[0005] When configuring gas injectors, there is a conflict in objectives between the necessary mass flow rate during an injection and the need for the lowest possible system pressure of the gas. As a result, gas injectors must have the greatest possible flow cross-sections. However, because space is usually limited, the large flow cross-sections are frequently unable to be realized by simple upscaling of the dimensions of the injectors, especially in the case of outwardly opening injectors.
BRIEF SUMMARY OF THE INVENTION
[0006] In contrast, the gas injector according to the present invention for the injection of gaseous fuel for an internal combustion engine has the advantage that a flow cross-section in an open injector is able to be increased, so that even at low system pressures a sufficiently large gas quantity is injectable within a predefined time. The gas injector according to the present invention has a very compact and small design, so that it can be used even in tight engine compartments. The gas injector according to the present invention includes a valve body and a dual valve needle having an outer needle and an inner needle. In addition, an actuator system is provided, which is designed to actuate the outer needle and the inner needle independently of each other in each case. In the present invention, it is therefore possible to actuate only the outer needle or only the inner needle or both needles at different times. The largest opening cross-section preferably results when both needles are actuated. The outer needle is a hollow needle, and the inner needle is situated in the hollow region of the hollow outer needle. Furthermore, a first sealing seat is developed between the valve body and the outer needle, and a second sealing seat is developed between the outer needle and the inner needle. Placing the inner needle within the outer needle makes for a very compact design. If both needles are in the open state, a large opening cross-section can be achieved, and the required gas quantity or gas mass is able to be injected within a predefined period of time even at the lowest possible system pressure.
[0007] The actuator system preferably includes a first actuator for actuating the inner needle and a second actuator for actuating the outer needle. This makes it possible to realize an individual actuation of the outer needle and the inner needle in a relatively simple manner. Although two actuators are admittedly required for this purpose, a broader usage spectrum results in this way, in which different injection strategies are able to be realized, as well. For example, the inner needle can be opened earlier than the outer needle, or the outer needle earlier than the inner needle, or both needles are opened simultaneously. The same also applies to the respective closing processes. As a result, different injection strategies with regard to the opening and closing of the gas injector are possible, depending on the intended use and the individual operating state of an internal combustion engine, for instance.
[0008] According to an alternative development of the present invention, the actuator system includes precisely one actuator, a first compression element and a second compression element. The first compression element is preferably situated between the inner needle and the outer needle, and the second compression element is preferably situated between the outer needle and the valve body. This configuration thus makes it possible to also realize a stepped opening of the inner needle and outer needle using precisely one actuator, preferably by selecting different prestress forces of the compression elements. The opening characteristic is therefore obtainable as a function of a lift effected by an actuator.
[0009] The prestress forces of the two compression elements especially preferably differ. Furthermore, the prestress forces of the two compression elements are preferably adjustable, so that different operating states of an internal combustion engine having different injection strategies are available, as well. The compression elements especially preferably are springs.
[0010] Moreover, the gas injector preferably includes a stop, which delimits a movement of the inner needle and/or the outer needle, so that a maximum lift can be specified in an uncomplicated manner. In particular when using two actuators for the individual actuation of the inner needle and the outer needle, the use of a stop makes it easy to restrict a maximum lift.
[0011] In addition, the gas injector preferably also includes a slaving element; after one of the two needles has traveled a predefined lift length, the other needle is carried along by this slaving element. Especially preferably, the slaving element is situated on the inner needle, which, once a predefined lift has been realized, then carries the outer needle along and lifts the outer needle off from the first sealing seat at the valve body.
[0012] Moreover, the actuator system preferably includes a magnet armature or a piezo actuator.
[0013] Especially preferably, the outer needle and the inner needle are outwardly opening closing elements. As a result, an outwardly opening gas injector having a compact design is able to be provided in an uncomplicated manner.
[0014] In addition, the gas injector is preferably used in internal combustion engines having direct injection. The gas injector is situated directly at a combustion chamber of an internal combustion engine and injects directly into the combustion chamber.
[0015] The present invention furthermore relates to a gas-operated internal combustion engine, which includes a gas injector according to the present invention. The internal combustion engine especially preferably is used in a vehicle.
[0016] Preferred exemplary embodiments of the present invention are described in detail below, with reference to the accompanying drawing. Identical or functionally equivalent parts are designated by the same reference numerals.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 shows a schematic sectional view of a gas injector according to the related art.
[0018] FIG. 2 shows a schematic sectional view of a gas injector according to a first exemplary embodiment of the present invention.
[0019] FIG. 3 shows a schematic sectional view of a gas injector according to a second exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] In the following text, a gas injector 1 according to a first preferred exemplary embodiment of the present invention is described in detail with reference to FIG. 2 .
[0021] As can be gathered from FIG. 2 , gas injector 1 includes a valve body 2 and a needle system which includes an outer needle 3 and an inner needle 4 . Inner needle 4 is situated in a hollow region 30 of outer needle 3 .
[0022] Moreover, gas injector 1 includes an actuator system 7 having a first actuator 71 and a second actuator 72 . First actuator 71 actuates inner needle 4 , and second actuator 72 actuates outer needle 3 . Inner needle 4 is guided inside outer needle 3 .
[0023] Moreover, a first sealing seat 5 is developed between outer needle 3 and valve body 2 . In addition, a second sealing seat 6 is formed between inner needle 4 and outer needle 3 . The two sealing seats are developed as circles. Outer needle 3 and inner needle 4 are both provided as outwardly opening needles, so that gas injector 1 is an outwardly opening injector.
[0024] In addition, gas injector 1 includes a first stop 8 , which restricts a lift travel of outer needle 3 , and a second stop 9 , which restricts a lift travel of inner needle 4 .
[0025] The provision of two separate actuators 71 , 72 makes it possible to actuate and move outer needle 3 and inner needle 4 separately. As a result, only outer needle 3 may lift off from first sealing seat 5 . Alternatively, it is also possible that only inner needle 4 lifts off from second sealing seat 6 . As a further alternative, outer needle 3 and inner needle 4 may be lifted off from their sealing seats together. In addition, different opening lifts of outer needle 3 and inner needle 4 are realizable, as well. As a result, the present invention makes it possible to execute quite different injection strategies, which in particular are dependent upon an operating point of an internal combustion engine.
[0026] A resetting of outer needle 3 and inner needle 4 takes place via restoring elements (not shown), such as springs.
[0027] FIG. 2 shows a partially open state of gas injector 1 , in which outer needle 3 has lifted off from first sealing seat 5 and inner needle 4 has lifted off from second sealing seat 6 . This is indicated by arrows A and B in FIG. 2 . This is not yet the maximum opening position because, as can be gathered from FIG. 2 , a space still remains between the plate-shaped end regions of outer needle 3 and inner needle 4 with respect to stops 8 , 9 in the region of first and second actuators 71 , 72 . The two actuators 71 , 72 of this exemplary embodiment are magnet armatures. However, it should be noted that piezo actuators may be used as well.
[0028] As indicated in FIG. 2 by arrows C, fuel is supplied via multiple openings 41 at the plate-shaped end of inner needle 4 , past second stop 9 , into a first space 20 in valve body 2 . The gas is then able to be supplied from first space 20 into a second space 21 via first through openings 31 in the plate-shaped end region of outer needle 3 . Outer needle 3 furthermore is provided with second through openings 32 in a center region, which form a connection between second space 21 and hollow region 30 of outer needle 3 . Fuel is therefore able to be guided to sealing seats 5 , 6 both at an inner side of outer needle 3 and an outer side of outer needle 3 . The flow routes of the gaseous fuel are indicated by the arrows in FIG. 2 .
[0029] According to the present invention, it is therefore possible to provide a gas injector 1 having a closing element which includes two needles, the closing element opening in the outward direction. Because of dual sealing seat 5 , 6 , it is also possible to inject greater gas quantities into a combustion chamber during an injection cycle. Gas injector 1 can be disposed directly at the combustion chamber and thus may be a directly-injecting gas injector.
[0030] FIG. 3 shows a gas injector 1 according to a second exemplary embodiment of the present invention. In contrast to the first exemplary embodiment, gas injector 1 of the second exemplary embodiment has an actuator system that includes precisely only one actuator 71 . In addition, further below, gas injector 1 of the second exemplary embodiment includes a first compression element 10 and a second compression element 11 . First compression element 10 is situated between inner needle 4 and outer needle 3 . Second compression element 11 is situated between outer needle 3 and valve body 2 . Compression elements 10 , 11 are cylindrical helical springs and have different spring constants. FIG. 3 shows the closed position of gas injector 1 . First sealing seat 5 and second sealing seat 6 are closed. Both compression elements 10 , 11 retain gas injector 1 in the closed position. If an injection of gas is to take place, actuator 71 will be actuated, so that inner needle 4 is moved in the direction of arrow A. The maximum lift of inner needle 4 is delimited by stop 8 . The axial movement of inner needle 4 compresses first compression element 10 . Outer needle 3 still remains closed until the prestress force of first compression element 10 , which is compressed more and more, exceeds the force of second compression element 11 . At this point, outer needle 3 opens as well. As a result, a gas injector 1 having a stepped opening characteristic can be described in the second exemplary embodiment. Inner needle 4 opens first, followed by outer needle 3 . It should be noted that different opening characteristics are able to be realized by selecting different spring constants of compression elements 10 , 11 . As an alternative, a slaving element may also be provided at inner needle 4 , which carries outer needle 3 along and opens it once a specific lift of inner needle 4 has been attained. | 4y
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BACKGROUND OF THE INVENTION
Tachometers have been used for many years with variable speed dynamoelectric machines either motors or generators, and perhaps are more commonly used with DC motors which are variable speed devices in order, to provide an accurate indication of the speed of the motor. Quite often this speed signal is returned to an electrical control circuit to correct for any mismatch between the desired and the actual speed. This may be a part of an entire drive system for a large piece of machinery, for example, where it is desired to closely coordinate the speeds of several motors driving different parts of the machinery so that a web, for example, moving through the machinery will not be stretched or broken.
The prior art has known many forms of tachometers, many of which have been constructed as small DC or AC generators in the form of separate dynamoelectric machines with their own bearings and driven in some manner from the shaft of the DC motor, the speed of which is to be sensed. In many cases the DC motor has driven a load at what is termed the back end of the motor and the front end of the motor has been provided with a shaft extension to drive such prior art tachometers. However, there are several occasions when the front end of the motor is not readily available from which to drive such a tachometer. Three such occasions are:
1. Where the DC motor has a double shaft extension, e.g. for tandem motor drives,
2. When a brake may be mounted on the front end of the motor, and
3. When the fan and cover of a totally enclosed fan cooled motor is provided on the front end of such DC motor.
When the front end of the motor is already being used for one of the above-mentioned purposes, then the prior art had difficulty in mounting a tachometer also on such front end of the motor. Such prior art mounting usually took the form of two choices: either a timing belt drive to a laterally mounted tachometer, or else a cantilever mounting of the tachometer with the tachometer driven coaxially from the front end shaft extension. In the former choice, the laterally displaced drive with a timing belt had additional problems of providing a suitable mounting for the tachometer and a suitable drive arrangement with space for the timing belt and pulley. In the latter choice the cantilever coaxial mounting of the tachometer meant that the tachometer increased the length of the motor by a minimum of about five inches and in many cases by as much as twenty-one inches where in combined analog and digital output from the tachometer was desired. In many cases room for such a long tachometer extension was simply not available. In both of these two choices of prior art tachometer mounting, the tachometer was a complete dynamoelectric machine by itself, not only with a rotor and stator but also a frame, end brackets and bearings at both ends of the shaft to support the tachometer rotor. This made an expensive construction. Also in many cases it was necessary to provide a flexible or universal shaft connection because one could not rely on the shaft of the tachometer being exactly coaxial with the shaft of the DC motor. In the prior art type without separate bearings, if the tachometer rotor and stator were not coaxial, then there was the problem of run-out between the tachometer rotor and stator which would give undesirable variations in the tachometer voltage output at a frequency of either one or two times the rotational speed.
SUMMARY OF THE INVENTION
The invention may be incorporated in a combined dynamoelectric machine and tachometer with the dynamoelectric machine having a frame, comprising in combination, an end bracket in said frame surrounding a rotatable shaft of the machine, wall means defining recess means in said end bracket, a tachometer rotor mounted axially within said recess means and connected to be rotated in accordance with rotation of said shaft of the machine, said tachometer rotor having a circular pole piece area with a plurality of magnetic poles, magnetically responsive transducer means having an electrical output, and means mounting said transducer means in said recess means close to said pole piece area of said rotor to be magnetically actuated by rotation of said tachometer rotor.
An object of the invention is to provide a direction sensing analog and digital tachometer built into a motor end bracket.
Another object of the invention is to provide a combined dynamoelectric machine and tachometer wherein the tachometer is a compact unit occupying a minimum of longitudinal space in the dynamoelectric machine.
Another object of the invention is to provide a compact low-cost tachometer stator assembly which mounts the magnetic transducers and contains the digital and analog circuitry in a protected enclosure.
Another object of the invention is to provide a tachometer stator which includes an externally available calibration adjustment and also includes terminals for the power supply and the analog and digital outputs.
Another object of the invention is to provide a tachometer with molded plastic rotor and stator assemblies which are explosion proof and resistant to chemical and moisture environments and also provided with simple locator means for achieving rotor and stator air gap spacing and concentricity.
Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawing.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a plan view, partly in section, of a combined dynamoelectric machine and tachometer embodying the invention;
FIG. 2 is a sectional view on line 2--2 of FIG. 1 of the tachometer mounted in the end bracket;
FIG. 3 is an enlarged sectional view of only the tachometer stator and rotor;
FIG. 4 is a view of the tachometer stator on line 4--4 of FIG. 3 with part of the enclosure broken away;
FIG. 5 is a top view of the tachometer stator;
FIG. 6 is a partial enlarged view similar to FIG. 2 and illustrating the rotor poles; and
FIG. 7 is a schematic diagram of an electrical circuit usable with the tachometer.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows generally the construction of a combined dynamoelectric machine 11 and tachometer 12. The dynamoelectric machine may be a generator but in the preferred embodiment is illustrated as a DC motor having variable speed characteristics. Such DC motor includes a frame 13 carrying a stator 14 which includes the pole pieces for a field cooperating with a wound rotor 15 or armature winding. The armature winding is connected to a commutator 16. Brushes 17 held by brush rigging 18 ride on the commutator for external electrical connection to the armature winding 15. The commutator 16 and armature winding 15 are the rotor of the machine 11 fixedly mounted on a shaft 20 journaled in bearings 21 which are mounted in a front end bracket 22 and a rear end bracket 23. The shaft 20 extending from the rear end bracket 23 is adapted to drive the usual load. The commutator 16 is usually provided within the front end bracket 22 in order that any servicing of the brushes or commutator may be at this front end away from the usual load. In FIG. 1, the shaft 20 is shown as a double shaft extension meaning that it extends not only from the rear end bracket 23 but also from the front end bracket 22.
As one example of a use for such a double shaft extension, the dynamoelectric machine 11 is shown as a totally enclosed fan cooled machine. To accomplish this the front end bracket 22 is machined with a short cylindrical coaxial shoulder 26 to provide a National Electrical Manufacturers Association standard "C" face mounting. This coaxial shoulder 26 provides a register fit for a fan cover 27. A fan 28 is mounted on the shaft 20 within the fan cover 27 to have an intake for air through a screen 29 and to have output air directed by a shroud 30 longitudinally along the sides of the motor frame 13.
FIG. 1 also illustrates in the dotted lines the mounting of a prior art tachometer 32. Such a tachometer 32 is shown of the pancake style for minimal added axial length but required a spider 33 for mounting the tachometer 32 in order to provide air openings between the legs of the spider to the screen 29. Also the shaft 20 had to be drilled and reamed at a coaxial aperture 34 to accept a small diameter shaft extension 35 to drive the tachometer 32. This prior art tachometer mount had the problem of shaft concentricity or run-out and also the problem of additional axial length.
FIGS. 2, 3, 4, 5 and 6 show the details of the tachometer 12 of the present invention. Such tachometer 12 is built into the front end bracket 22 closely adjacent the front bearing 21. In FIG. 2 a cover 37 has been broken away to show the structure. A wall 38 has a circular portion 39 and a sector portion 40. The circular wall portion 39 is coaxial with the shaft 20 and encloses a rotor 41 of the tachometer 12. The tachometer 12 is provided with a stator 42 within the sector wall portion 40. This wall 38 provides an axially extending recess within the front end bearing 22 for locating and physically protecting the tachometer 12.
The tachometer rotor 41 is provided with a metal hub 44 which may be of machinable material such as aluminum. Secured to it is a hardened plastic intermediate area 45 carrying a magnetic rim 46. This rim provides a circular pole piece area with a plurality of magnetic poles. In the preferred embodiment this is a large number of magnetic poles and they are radially directed. The magnetic rim may be physically toothed to provide the plural magnetic poles or as in the preferred embodiment may be a smooth cylindrical rim as shown in FIG. 7 into which the north and sourth poles are permanently magnetized with a neutral area between such poles. The rotor 41 may be held in place on the shaft 20 by set screws 47.
The tachometer stator 42 has a frame 50 on which transducer means 51, 52 is mounted. This transducer means 51, 52 is responsive to the magnetic pole piece area or magnetic rim 46 of the rotor 41 and in the preferred embodiment includes at least a first Hall effect switch 51. Also in this preferred embodiment a second Hall effect switch 52 is provided in order to provide rotational direction sensing. The Hall effect switches 51 and 52 each have an operating surface to be magnetically influenced by the pole piece area 46 of the rotor 41. The frame 50 of the tachometer stator 42 has an arcuate portion 53 in order to accommodate the tachometer rotor 41. The operating surfaces of the Hall switches 51 and 52 extend outwardly from or are closely adjacent to this arcuate surface 53 and may be covered with a thin layer of hardened plastic material for moisture and corrosion resistance. The Hall switches are also mounted in threaded barrels 54 for air gap adjustment.
The frame 50 also mounts speed signal processing circuitry or an electrical circuit 55 and this electrical circuit may be mounted on first and second printed circuit boards 56 and 57. The frame 50 includes a metal base 59 mounting the Hall switches 51 and 52. Other large circuit components such as a range adjustment or calibration adjustment potentiometer 58 are mounted on the circuit boards 56 and 57, which in this preferred embodiment are stacked one on top of the other and are sector shaped for a compact electrical circuit which will fit within the recess 43. The front end bracket 22 is provided with a radially directed aperture 60 to provide tool access to the adjustable potentiometer 58 when the stator 42 is in proper position in the recess 43. Bushings 61 and screws 62 may be used to secure the printed circuit boards 56 and 57 in a spaced position and also fitted into the bushings 61 may be locator means 63. These locator means may be machine screws fitting in apertures in the front end bracket 22 and be slightly enlarged for slight adjustment of the tachometer stator 42. In this way the tachometer stator would be located by shims or feeler gauges. However in the preferred embodiment the locator means 63 are accurately sized dowel pins fitting within close tolerance apertures 64 in the front end bracket 22 to precisely locate the tachometer stator 42 relative to the tachometer rotor 41 for both air gap and concentricity. A mounting screw 65 may be provided through the frame 50 into the front end bracket 22 to secure such tachometer stator 42 in place. Terminal means 68 is provided on the frame 50 for example on one or both printed circuit boards 56 and 57. Individual conductors from a cable 69 are connected to the terminal means 68 and this cable 69 passes through a radially directed fitting 70 on the outer circumference of the front end bracket 22 for external electrical connection to the tachometer 12.
The front end bracket 22 in many dynamoelectric machines is made of cast iron and in such case the bracket material will conduct any leakage flux to the shaft and such flux may improperly influence the Hall effect switches. In such cases magnetic flux shielding is provided for the Hall switches 51 and 52 by providing a metal shield 110 of a high permeability substance, for example, mu-metal so as to capture any leakage flux from the dynamoelectric machine 11 and direct it away from the Hall switches. The front end bracket may be case aluminum, rather than cast iron, but in either case, the electrical conductivity may not provide sufficient RF shielding. Accordingly, the RF shielding may be enhanced by a metal shield 72 around the tachometer stator 42 or at least between the stator 42 and the end bracket 22 in the recess 43. The entire tachometer stator 42 may be potted in a hardened plastic material or may be encased in a thin wall hardened plastic case. This will provide corrosion and moisture resistance for the entire tachometer stator. Also the rotor itself is a combination of metal and molded plastic so that the stator and rotor are intrinsically explosion proof and resistant to chemical and moisture environments.
FIG. 6 shows an enlarged view of part of the tachometer rotor 41 and the magnetic pole piece area 46. The multiple poles formed as permanent magnets are indicated in the FIG. 6 and illustrate that the rotor need not be a toothed rotor, it may have a smooth surface. The Hall switch 51 is illustrated in FIG. 6 as positioned in the threaded barrel 54. A magnetic flux concentrator 49 is preferably used with the Hall switch 51. This concentrator may be an E shape to help provide a return flux path to adjacent poles of the rotor. Alternatively, as shown in FIG. 6, this flux concentrator 49 may be merely a small slug of permeable material closely adjacent the side opposite the operating surface of the Hall switch 51. This will help promote the magnetic flux path to be transversely through the Hall switch 51.
The electrical circuit 55 is shown in FIG. 7 and includes the Hall effect switches 51 and 52 which are transducers actuated by the changing magnetic flux from the multiple pole tachometer rotor 41. The Hall effect switches are passive devices which require that an operating voltage be applied in one plane and in a perpendicular plane the electrical switching action is achieved. Terminals 80 and 81 are a part of the terminal means 68 and an operating voltage, for example, 12 volts positive and 12 volts negative may be applied to terminals 80 and 81, respectively, and after being regulated by Zener diodes 82 appear as regulated output voltages of plus 10 volts and -10 volts, for example, on conductors 84 and 85, respectively. Each Hall switch has four terminals Nos. 1, 2, 3 and 4 with the plus 10 volts being applied to the terminal 4 on each switch and the terminals No. 1 being connected to a conductor 86 which is 0 volts. The output of each Hall switch appears between terminals 1 and 3. Terminal 3 on Hall switch 51 is connected to an output terminal 87 and the third terminal on Hall switch 52 is connected to an output terminal 88. Amplifiers may be provided in this connection if desired in order to increase the output power. One digital signal output is obtained between terminal 87 and the zero volt conductor 86 and a second digital output is obtained between terminal 88 and the conductor 86. In this manner the tachometer 12 provides a two phase digital signal output.
This circuit 55 also includes means to provide an analog signal output. A digital to analog convertor 91 is provided and has a digital input from the terminal 3 of the Hall switch 51. The output is on a conductor 92 as an analog signal, the magnitude of which depends upon the frequency input of the digital signal. This analog output is passed to an operational amplifier 94 through a circuit 93 which may be an inverter circuit. This circuit 93 includes switches shown as FET switches 95 and 96. When the FET switches 95 are turned on, the analog signal is supplied directly to a non-inverting input terminal 97 of the operational amplifier 94. When the FET switches 96 are turned on the analog signal is supplied directly to the inverting input terminal 98 of the amplifier 94. In this way the analog signal on the output terminal 99 is made either positive or negative depending upon which pair of FET switches is on.
A D flip-flop 102 is provided in the circuit 55. This D flip-flop has a D or data input on a terminal 103 from the third terminal of the Hall switch 52. The clock input terminal 104 of this flip-flop is connected to the third terminal of Hall switch 51. A D or data flip-flop is one wherein when the input is clocked on the clock input 104, then whatever signal, either logic zero or logic one, that is present on the data input terminal 103 will be clocked through to appear on the Q output terminal 105. The Q output terminal 106 is of course of the opposite logic condition. The Q terminal 105 is connected to turn on the FET switches 95 and the Q terminal is connected to turn on the FET switches 96 when such terminal is a logic one condition.
OPERATION
The tachometer 12 has the advantage that it may be installed in the dynamoelectric machine 11 at the time of the initial manufacture and sale or may be readily installed in the field at a later date. If installed later, the cover 37 may be removed for access to the recess 43. The tachometer stator 42 may be mounted in position and the locator means provided by the dowel pins 63 will fit within the close tolerance apertures 64 in the front end bracket 22. The tachometer frame 50 may be secured in position by the mounting screw 65. The cable 69 may be passed through the fitting 70 for connection to the terminal means 68. The tachometer rotor 41 may be slipped over the end of the shaft 20 and secured in any convenient manner, as by the set screws 47. The locator means 63 thus provides proper location of the stator and rotor of the tachometer for both air gap and concentricity. The cover 73 may then be remounted to enclose the tachometer 12 within the recess 43.
The tachometer 12 may be easily calibrated in the field by means of a counter and timer such as a stop watch. In the preferred embodiment, the rotor 41 may have 60 north poles and 60 south poles for a 120 pole rotor providing 60 pulses per revolution per Hall switch. The dynamoelectric machine 11 may be operated at some calibrating speed, for example, 1000 rpm and at such speed there should be 60 thousand pulses provided on the digital output terminals 86 and 87 in 1 minute's time. The speed of the machine 11 may thus be adjusted to provide such counted number of 60 thousand pulses in 60 seconds. The range adjustment potentiometer 58 may then be moved by some external tool such as a screw driver to provide the predetermined analog output voltage for that speed. Merely as an example this might be 8 volts at the speed of 1000 rpm. In this manner the tachometer 12 may be used to calibrate itself rather than requiring one to connect some precalibrated tachometer in a temporary manner in order to calibrate the built in tachometer 12.
Where the dynamoelectric machine 11 has double shaft extension, as shown in FIG. 1, then the tachometer 12 built within an axial recess in the front end bracket 22 is especially valuable. The front end shaft extension may be used to drive a fan 28 for a totally enclosed fan cooled motor 11 and the fan cover 27 may be mounted on the C face register fit or shoulder 26 on the front end bracket 22. This mounting may be made without interference with the tachometer 12 and may be made whether or not such tachometer is present in the machine 11.
FIG. 1 illustrates one form of prior art tachometer 32 in dotted lines which was a prior art form of mounting such tachometer on the outboard end of the fan cover 27. It was mounted on the spider 33 with the spider required in order that air might enter between the legs of the spider. Many other prior art tachometers were not nearly as compact in axial dimension as shown from the tachometer 32. In many cases it was necessary to mount a cantilever bracket axially extending from the spider 33. Then on this cantilever bracket one would mount a separate free standing tachometer and couple it to the small diameter shaft extension 35 by a flexible coupling or universal joint. This made a very long extending tachometer which was cumbersome and in many cases could not be accommodated in the environment of the motor 11. Some prior art tachometers which were combined digital and analog output tachometers extended as much 21 inches from the face of the mounting, in this case the outboard face of the fan cover 27.
Further in many cases if the motor 11, as a totally enclosed fan cooled motor, was supplied without a tachometer, the shaft 20 might not be any longer than necessary to just mount the fan 28. In such case it did not extend out to the screen 29 and there was not any way in which a tachometer could be mounted outboard of the motor 11. In the present case the shaft 20, even if for only a single ended shaft motor, will always extend at least to the outer face 25 of the front end bracket 22, which face is that on which the C face register fit shoulder 26 is provided. Accordingly, there is always the provision for field installation of the tachometer 12.
The tachometer 12 may be provided in many different frame sizes of dynamoelectric machines 11, for example, frame sizes 180 to 400. If the shaft at that axial location does not have the proper diameter, then the metal hub 44 may be readily machined to accept the shaft diameter as it exists in the machine 11.
Typical Hall switches currently available are turned on at a flux density of 50 to 100 gauss and turned off at -50 to -100 gauss. The alternate north and south poles may be magnetized in the rim 46. Pole strengths at the peripheral surface of the rotor rim may be in the range from 350 to 400 gauss and the air gap may be in the order of 0.025 to 0.050 inches. This may include any plastic covering over the operating surface of the Hall switches 51 and 52. The peripheral distance between adjacent north and south poles may be in the order of 0.100 inches in order to minimize interpolar leakage flux and to maximize the useful air gap flux.
In the tachometer 12 there is means included in the rotor 41 and the transducer means 51, 52 to sense direction as well as rotational speed of the tachometer rotor 41. In the preferred embodiment this is provided by using two Hall switches 51 and 52 with the associated circuit 55. The stator frame 50 accurately locates the Hall switches relative to the rotor especially by the locator means 63. The stator frame 50 also accurately locates the two Hall switches so that the square wave outputs thereof are substantially 90 electrical degrees apart. In order to do this the circumferential spacing between the Hall switches is p(n + 1/2) where n is any integer and p is the circumferential pole pitch between adjacent north and south poles.
FIG. 7 illustrates the electrical circuit 55 and shows why the nominal 90° phasing between the Hall switches 51 and 52 is preferred. This phase displacement may not be exactly 90° in fact it may be most any angle other than 180° and integral multiples thereof. On FIG. 7 square wave inputs are drawn at the data input 103 and the clock input 104 of the flip-flop 102. This D flip-flop will trigger upon a positive going logic signal input as shown by the arrow 108. If the data input from the Hall switch 52 lags the signal from the Hall switch 51, then at the time of triggering or clocking the flip-flop 102, the data input will be a logic zero as shown at time 109. Thus Q will be a zero and Q will be logic one. This turns on the FET switches 96 supplying the analog signal to the inverting input 98 of the operational amplifier 94 and thus the analog signal output at terminal 99 is negative. Conversely, if the Hall switch 52 leads the Hall switch 51 by nominally 90° or any range from 1° to 179°, then the signal clocked through the flip-flop 102 will make Q terminal 105 a logic one, turning on FET switches 95 and supplying the output of the digital to analog converter 91 to the non-inverting input 97 of the operational amplifier 94. Thus the analog output signal at terminal 99 will be a positive signal. In this manner the circuit 55 senses clockwise or counter clockwise rotation of the rotor 41.
It will be noted that the recess 43 establishes that the tachometer rotor 41 is mounted in the same longitudinal position as the tachometer stator 42, these two elements at least partially overlap in a longitudinal direction.
The present disclosure includes that contained in the appended claims, as well as that of the foregoing description. Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed. | 4y
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FIELD
Embodiments of the invention relate to the manufacturing of complementary metal-oxide-semiconductor (CMOS) devices. More particularly, embodiments of the invention relate to integrating n-type and p-type metal gate transistors within a single CMOS device.
BACKGROUND
Prior art CMOS devices manufactured with prior art semiconductor processes typically have polysilicon gate structures. Polysilicon, however, can be susceptible to depletion effects, which can add to the overall gate dielectric thickness in the CMOS device. Furthermore, as the effective physical gate dielectric thickness decreases, the polysilicon depletion contributes proportionally to the total dielectric thickness. It is, therefore, desirable to eliminate polysilicon depletion in order to scale gate oxide thickness.
Metal gates, on the other hand, are not as susceptible to depletion as polysilicon and are in many ways preferable to polysilicon for forming gate structures. Typical prior art semiconductor processes, however, do not incorporate n-type and p-type metal gates within the same device or integrated circuit. This is due, in part, to the complexity and cost of developing a semiconductor process that can reliably deposit metal gate structures of differing types into the same semiconductor device or integrated circuit.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the invention are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements and in which:
FIG. 1 illustrates the state of transistors after depositing ILD 0 according to one embodiment.
FIG. 2 illustrates the state of transistors after ILD 0 polish-back to expose polysilicon gate structures according to one embodiment.
FIG. 3 illustrates the state of transistors after selective n-type poly etch according to one embodiment.
FIG. 4 illustrates the state of transistors after depositing n-type metal according to one embodiment.
FIG. 5 illustrates the state of transistors after polishing the n-type metal according to one embodiment.
FIG. 6 illustrates the state of transistors after selectively etching p-type polysilicon according to one embodiment.
FIG. 7 illustrates the state of transistors after depositing p-type metal according to one embodiment.
FIG. 8 illustrates the state of transistors after polishing the p-type metal according to one embodiment.
FIG. 9 illustrates the completed transistors according to one embodiment.
FIG. 10 illustrates the state of transistors after an optional implant patterning according to one embodiment.
FIG. 11 illustrates the state of transistors after n-type implant and optional ash.
FIG. 12 illustrates the state of transistors after a second selective n-type polysilicon etch.
DETAILED DESCRIPTION
Embodiments of the invention described herein relate to semiconductor manufacturing. More particularly, embodiments of the invention described relate to integrating n-type and p-type metal gate transistors within the same complementary metal-oxide-semiconductor (CMOS) device or integrated circuit.
In order to manufacture CMOS devices and integrated circuits that can avoid the effects of gate depletion, embodiments of the invention incorporate n-type and p-type metal gates into the same CMOS device or integrated circuits.
FIG. 1 illustrates a cross-section of a CMOS device containing a p-type transistor and an n-type transistor after depositing ILD 0 (“Inter-layer dielectric”) according to one embodiment. In FIG. 1 , poly-silicon gate transistors 105 , 110 are fabricated using standard CMOS processing techniques in order to prevent silicide formation on the poly-silicon gate electrode. The nitride hard masks 115 are to protect the gate structures during silicidation and ILD 0 120 is deposited on the structure.
The ILD 0 is polished back to expose the doped polysilicon gates in FIG. 2 . The ILD 0 polishing also removes residual silicide around the nitride masking layer. After the polysilicon gates 205 , 210 are exposed, an ammonium hydroxide etch is used to selectively etch away 305 the n-type polysilicon. The ammonium hydroxide etch is low temperature (e.g., <40 deg. Celsius), uses sonication, and has a concentration of approximately 2-29%. The result of the polysilicon etch is illustrated in FIG. 3 .
Removal of the p-type polysilicon above the gate dielectric creates a damascene-like “trench” which is filled with an n-type metal 405 , such as Hf, Zr, Ti, Ta, or Al, as illustrated in FIG. 4 . Alternatively, the trench can be filled with an alloy containing an n-type component using PVD (“Physical vapor deposition”), CVD (“Chemical vapor deposition”), or ALD (“Atomic Layer deposition”). CVD and ALD may use an organometallic or halide precursor, and a reducing atmosphere. Furthermore, the thickness of the n-type metal or alloy can be such that the trench is only partially filled. For example, the thickness of the n-type metal or alloy can vary from approximately 50 angstroms to approximately 1000 angstroms in various embodiments. If the trenches are not completely filled, they may be filled with an easily polished metal, such as W (“Tungsten”) or Al (“Aluminum”).
The n-type metal is polished back to create the n-type metal gates 505 and to expose the p-type polysilicon gate 510 as illustrated in FIG. 5 .
FIG. 6 illustrates the transistors after a selective dry etch is performed to remove the p-type polysilicon without removing the n-type metal gate. The selective dry etch can be performed using a parallel plate or ECR (“Electron cyclotron resonance”) etcher and SF6 (“Sulfur hexafluoride”), HBr (“Hydrogen Bromide”), HI (“Hydrogen Iodide”), Cl2 (“Chlorine”), Ar (“Argon”), and/or He (“Helium”). Alternatively, a wet etch, such as approximately 20-30% TMAH (“Tetramethylammonium Hydroxide”) at approximately 60-90 degrees Celsius with or without sonication may also be used to remove the p-type polysilicon gate.
A p-type metal, such as Ru (“Ruthenium”), Pd (“Palladium”), Pt (“Platinum”), Co (“Cobalt”), Ni (“Nickel”), TiAlN (“Titanium Aluminum Nitride”), or WCN (“Tungsten Carbon Nitride”) can be used to fill the gate trench created by etching the p-type polysilicon gate 605 . Alternatively, an alloy using p-type metal can be deposited in the trench using chemical vapor deposition or atomic layer deposition with an organometallic precursor and a reducing atmosphere. Furthermore, the thickness of the p-type metal or alloy can be such that the trench is only partially filled. FIG. 7 illustrates the transistors after the p-type metal or alloy has been deposited in the gate trench 710 .
The p-type metal or alloy is polished back, as illustrated in FIG. 8 , to create the p-type gate structures 805 , 810 , and ILD 0 is again deposited to provide room for the contact layer.
Contacts 903 are etched and deposited, as illustrated in FIG. 9 , resulting in the final transistor structure.
Rather than using a dry etch to remove the p-type polysilicon as described above, the p-type polysilicon gate can be converted to n-type in order to allow a gentler wet etch to remove the polysilicon rather than a dry etch. For example, after the p-type polysilicon 1010 has been exposed, rather than using a selective dry etch to remove the polysilicon, an n-type implant 1015 is performed to change the doping of the polysilicon in order to allow an ammonium hydroxide etch to be performed, as illustrated in FIG. 10 .
The result of the implant and ash (if required) is illustrated in FIG. 11 . An ammonium hydroxide etch removes the remaining polysilicon gate structure 1210 resulting in the structure illustrated in FIG. 12. A p-type metal or alloy may then be deposited in the trench left by removing the p-type polysilicon gate as described above.
While the invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments, which are apparent to persons skilled in the art to which the invention pertains are deemed to lie within the spirit and scope of the invention. | 4y
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CROSS-REFERENCE TO RELATED COPENDING PATENT APPLICATIONS
The following patent applications which are assigned to the assignee of the present invention cover subject matter related to the subject matter of the present invention: "Data Processor Controlled Display System With a Plurality of Selectable Basic Function Interfaces for the Control of Varying Types of Customer Requirements and With Additional Customized Functions", Attorney Docket No. AM9-97-153 U.S. patent application Ser. No. 09/053,210; "Data Processor Controlled Display System With a Plurality of Switchable Customized Basic Function Interfaces for the Control of Varying Types of Operations", Attorney Docket No. AM9-97-155 U.S. patent application Ser. No. 09/053,214; "Data Processor Controlled Display System for the Control of Operations With Control Properties Which are Selectably Constant or Variable", Attorney Docket No. AM9-97-156 U.S. patent application Ser. No. 09/053,207; "Data Processor Controlled Display Interface With Tree Hierarchy of Elements View Expandable into Multiple Detailed Views", Attorney Docket No. AM9-97-157 U.S. patent application Ser. No. 09/053,209; "Data Processor Controlled Interface with Multiple Tree of Elements Views Expandable into Individual Detail Views", Attorney Docket No. AM9-97-158 U.S. patent application Ser. No. 09/052,858; and "Data Processor Controlled Display System With a Tree Hierarchy of Elements View Having Virtual Nodes", Attorney Docket No. AM9-97-160 U.S. patent application Ser. No. 09/053,213; all are assigned to International Business Machines Corporation by Claudia Alimpich et al. and all are filed concurrently herewith.
TECHNICAL FIELD
The present invention relates to interactive computer controlled display systems for controlling operations and particularly to user friendly display interfaces for the control of such operations.
BACKGROUND OF THE INVENTION
The computer and computer related industries have benefitted from a rapidly increasing availability of data processing functions. Along with this benefit comes the problem of how to present the great number and variety of available functions to the interactive operator or user in display interfaces which are relatively easy to use. In recent years, the hierarchical tree has been a widely used expedient for helping the user to keep track of and organize the operative and available functions. In typical tree structures such as those in Microsoft Windows 95™ and IBM Lotus™ systems, there is presented on the display screen a variety of available functions and resources in tree hierarchies with classes and subclasses of functions and resources displayed as objects in a descending and widening order based upon some kind of derivation from the next higher class or subclass.
The relationships between items in different levels of a tree are sometimes referred to as parent/child relationships. In some structures, child items can inherit properties from their parent items. In such structures when specific properties are changed in the parent item, those changed properties will be inherited by its child items. However, there may arise circumstances where it is desirable to effect changes in all child objects of a given parent without modifying the parent and without necessarily having to modify each child. The conventional tree structures which allow inheritance would not be adequate for such purpose because the properties of the parent would have to be modified in order to pass down the modification.
SUMMARY OF THE INVENTION
The present invention provides a tree display interface which provides for the modification of child objects through their parents without modifying the parent. As a result, the parent remains unmodified in the tree structure and continues to represent its original functions and resources.
Thus, the present invention provides an ease of use tree display interface through which operators may effectively manage computer controlled operations. This is accomplished through an interactive display interface providing a tree of items. Parent items at one level have child items at the next lower level. Interactive means are provided for the modification of the properties of child items in said tree wherein the operator is enabled to designate at the parent level the modification of the properties to be made in the child items represented by said parents, but without modifying the parent.
The interface also provides for the interactive modification of the properties of individual child items in the tree independently of the designation of property modification at the parent level. The invention may effectively be used in application or operating system interface including such interfaces for production operations as well as in communications.
The tree system of the present invention may be distinguished from existing trees of elements having parent child relationships where the child elements inherit or receive attributes from the parents. In the operation of the present invention, there is no passing down of attributes from parent to child elements. Furthermore, the parent item may have entirely different properties than its children. Nevertheless, in the present invention, the parent item is still capable of representing its child items. In this manner, a modification may be made in the properties of the child items by designating the change at the representative parent item, but, unlike the above inheritance relationships, there is no change in the parent's properties.
For another embodiment, attention is directed to copending U.S. Patent Application: "Data Processor Controlled Display System With a Tree Hierarchy of Elements View Having Virtual Nodes", C. Alimpich et al., filed on the same date as the present application (Attorney Docket No. AT9-97-160) which is cross-referenced above and describes a tree with virtual elements. The virtual tree elements described in that application may be used as the parent items of the present invention through which the child items are changed without changing the parent. Since such parent items would be virtual, they would have no properties themselves which could be changed; yet the virtual parent which represents the child items could be used to effectuate a change in the properties of the child items.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of an interactive data processor controlled display system including a central processing unit which is capable of implementing the program of the present invention for presenting tree views of items;
FIG. 2 is a diagrammatic view of a display screen on which an initial tree view of items is shown prior to any user selection;
FIG. 3 is the view of the display screen of FIG. 2 showing the tree resulting from the selection of items at a couple of levels from the tree of items of FIG. 2 and the designation of a parent item for modification of its child items;
FIG. 4 is the view of the display screen of FIG. 3 during the modification of all of the child items of a selected parent item;
FIG. 5 is the view of the display screen of FIG. 3 during the next step of modification after the step of FIG. 4;
FIG. 6 is the same view of the display screen as FIG. 3 after the modification of the child items of the designated parent item has been completed;
FIG. 6A is tree view of the display screen of FIG. 6 expanded to show the child items of the designated parent item of FIG. 6;
FIG. 7 is the view of the display screen of FIG. 3 after the views on the screen have been expanded to show the child items of a selected parent item from the tree of FIG. 3;
FIG. 8 is the view of the display screen of FIG. 7 during the modification at selected child item level;
FIG. 9 is the view of the display screen of FIG. 7 during the next step of modification after the step FIG. 8 with respect to said selected child item;
FIG. 10 is the same view of the display screen as FIG. 7 after the modification of the selected child item has been completed;
FIG. 11 is a flowchart showing the development of the program of the present invention for designating the child items for modification both at the parent and individual child levels; and
FIG. 12 is a flowchart showing the running of the program described with respect to FIG. 11.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a typical data processing system is shown which may function as the computer controlled display terminal used in implementing the tree views of the present invention. A central processing unit (CPU), such as one of the PC microprocessors available from International Business Machines Corporation, is provided and interconnected to various other components by system bus 12. An operating system 41 runs on CPU 10, provides control and is used to coordinate the function of the various components of FIG. 1. Operating system 41 may be one of the commercially available operating systems such as DOS or the OS/2 operating system available from International Business Machines Corporation (OS/2 is a trademark of International Business Machines Corporation); Microsoft Windows 95™ or Windows NT™, as well as Unix and AIX operating systems. A programming application for presenting tree views of action queues and modifying such queues in accordance with the present invention, application 40 to be subsequently described in detail, runs in conjunction with operating system 41 and provides output calls to the operating system 41 which implements the various functions to be performed by the application 40.
A read only memory (ROM) 16 is connected to CPU 10 via bus 12 and includes the basic input/output system (BIOS) that controls the basic computer functions. Random access memory (RAM) 14, I/O adapter 18 and communications adapter 34 are also interconnected to system bus 12. It should be noted that software components including the operating system 41 and the application 40 are loaded into RAM 14 which is the computer system's main memory. I/O adapter 18 may be a small computer system adapter that communicates with the disk storage device 20, i.e. a hard drive. Communications adapter 34 interconnects bus 12 with an outside network enabling the data processing system to communicate with other such systems, particularly when the operations controlled by the interfaces of the present invention are in a network environment or when the controlled operations are in communications systems. I/O devices are also connected to system bus 12 via user interface adapter 22 and display adapter 36. Keyboard 24, trackball 32, mouse 26 and speaker 28 are all interconnected to bus 12 through user interface adapter 22. It is through such input devices that the user interactive functions involved in the displays of the present invention may be implemented. Display adapter 36 includes a frame buffer 39 which is a storage device that holds a representation of each pixel on the display screen 38. Images may be stored in frame buffer 39 for display on monitor 38 through various components such as a digital to analog converter (not shown) and the like. By using the aforementioned I/O devices, a user is capable of inputting information to the system through the keyboard 24, trackball 32 or mouse 26 and receiving output information from the system via speaker 28 and display 38. In the illustrative embodiment, which will be subsequently described, the tree of action queues interfaces will be shown with respect to the control of high throughput printers such as electrophotographic or laser printers. A local printer system 44 may be accessed and controlled via printer adapter 43 while, as previously mentioned, networked printers may communicate via communications adapter 34.
There will now be described a simple illustration of the present invention with respect to the display screens of FIGS. 2 through 10. When the screen images are described, it will be understood that these may be rendered by storing an image and text creation programs, such as those in any conventional window operating system in the RAM 14 of the system of FIG. 1. The operating system is diagrammatically shown in FIG. 1 as operating system 41. The display screens of FIGS. 2 through 10 are presented to the viewer on display monitor 38 of FIG. 1. In accordance with conventional techniques, the user may control the screen interactively through a conventional I/O device such as mouse 26 of FIG. 1, which operates through user interface 22 to call upon programs in RAM 14 cooperating with the operating system 41 to create the images in frame buffer 39 of display adapter 36 to control the display on monitor 38.
The display screen of FIG. 2 shows a tree 50 of levels in region 52 of a display screen. Also shown is menu bar 51. In the example being described, the tree will pertain to levels of items in to be processed during printer operations. Thus, the items may be awaiting various printing related actions to be applied to them. In FIG. 3, Queue 1 is expanded to show the next lower level, a queue of Printer Jobs 53: Job1 through Job4. In order to make a modification of actions to be applied, Jobs representation 72 has been selected by the operator, which has resulted in an expanded view 70 of all four jobs in the job queue giving details of actions to be carried out. For purposes of this example, let us assume that after reviewing this information, the operator wishes to modify actions applied to all of the documents which are child items under Job3. These child items (documents) are not shown in this screen but may be seen hereinafter, as in FIG. 6A as group 62 of Doc1 through Doc3. Thus, the operator selects Job3, 71 which is shown highlighted in FIG. 3. This commences the operation to modify all of Doc1 through Doc3 as follows. First, the operator selects Job modification 55 from menu bar 51 in FIG. 4. This drops menu 56 from which the operator selects the "Change Media" process. This results in the dialog box 57 of FIG. 5 appearing on which the operator scrolls until the item in scroll window 58 is "legal", which indicates that the action modification is the change in media from letter to legal paper. The operator then confirms the change by pressing the OK button 59. This results in the display screen of FIG. 6 which indicates that in Job3 all of the child documents have had the actions to be applied to them modified so that they will be printed on legal paper. This will be clearer with respect to FIG. 6A which shows the group of child documents: Doc1 through Doc3 with the medium modified in all so that legal paper will be used. The group of child items or documents in FIG. 6A has been brought up by the operator pointing and clicking on Job3 which is shown highlighted 61 to indicate its section for display of the child documents in the queue 62. Thus, the operator, by designating Job3, which represents its child documents, Doc1 through Doc3 for change to legal paper has modified Doc1 through Doc3 to be printed on legal paper. However, Job3 itself has not been modified, it remains unchanged in Queue1.
Now commencing with FIG. 7 there will be described a procedure whereby an individual child item may be modified as to the actions to be applied to it without modifying other child items in the group from its parent. One of the child documents in the group represented by Job1 is to be individually modified. The operator selects Job1 which is shown highlighted 63. This brings up document group 64. Doc1 is selected by the operator and thus highlighted 65 which indicates that it is to be changed. Then, FIG. 8, the "Documents" item 66 is selected from menu bar 51, menu 67 drops down and "Change Media" is selected. This results in the dialog box 68 of FIG. 9 appearing on which the operator scrolls until the item in scroll window 73 is "legal", which indicates that the action modification is the change in media from letter to legal paper for Doc1. The operator then confirms the change by pressing the OK button 74. This results in the display screen of FIG. 10 which indicates that Doc1 has had its paper changed from letter to legal while other child items, Doc2 and Doc3 remain with letter paper.
Now with reference to FIG. 11 we will describe a process implemented by a program according to the present invention. The started 90 program is continuous and involves the development of the display screen interfaces previously described with respect to FIGS. 2 through 10. In the flowchart of FIG. 11, a basic tree interface is set up, step 91, wherein the items at tree nodes represent items involved in the operations being controlled. In the present example, these would be printer operation control interfaces. Of course, appropriate conventional linkages are set up between the actual real-time items involved in the operations and representations of the items displayed on a screen whether these representations be text or icons, step 92.
Then a process is set up whereby the operator may designate modifications at parent level modifications in the actions to be applied to child items of that parent and to have such modifications applied to all of the child items, step 93, without any corresponding modification to the parent. These are the modifications described with respect to FIGS. 3 through 6A.
Then, step 94, a process is set up by which the operator may elect to change actions applied to only a child item individually. This type of modification has been described with respect to FIGS. 7 through 10. Next, step 95, a set up is made whereby the modifications made by the processes of steps 93 and 94 are reflected in the displayed tree; in this connection, modifications made by the process of step 93 are reflected in FIG. 6A, while modifications made by the process of step 94 are reflected in FIG. 10.
Now that the basic program has been described and illustrated, there will be described, with respect to FIG. 12, a flow of a simple operation showing how the program could be run. First, step 80, the basic trees of items used, FIGS. 2 through 10, and described in steps 91 and 92 of FIG. 11 are set up. Next, step 81, a determination is made as to whether the operator has designated an item at a parent level in order to make an overall action modification in the child items represented by this parent. If Yes, then, step 82, an appropriate set of screen interfaces for this modification are provided, e.g. the interfaces of FIGS. 4 and 5. The modifications are recorded in the system for all of the child items represented by the parent, step 83, and the changes are shown on the display, step 84, e.g. the changes shown in FIGS. 6 and 6A. Then, step 85, a determination is made as to whether the operator has selected a modification to be made in just one of the individual child items represented by a parent, e.g. the individual child item change selected in the screen of FIG. 7. Step 85 also would have been done directly if the decision from step 81 had been No. If the decision from step 85 is Yes, then, step 86, an appropriate set of screen interfaces for this modification are provided, e.g. the interfaces of FIGS. 8 and 9. The modifications are recorded in the system for the individual child item, step 87, and the changes are shown on the display, step 88, e.g. the changes shown in FIG. 10. The process flow then returns to decision step 81 via branch "A", and a further determination is awaited on additional action modifications to be designated by the operator. Step 81 would have been returned to directly if the decision from step 85 had been No.
While the present invention has been described using trees of items in printer operations as the illustrative example, the invention is equally applicable to the management and control of a wide variety of operations including the management of directories/folders and files/documents. For example, the present invention would allow all documents in a folder to be printed by specifying a print operation/action at the folder level. Likewise, all documents could be deleted by specifying, at the folder level, a deletion of all documents without deleting the folder itself. Other properties of the documents (e.g. format, font, etc.) could also be changed at the folder/directory level. The invention is equally applicable to the management of industrial, chemical, and manufacturing production operations including the manufacturing of integrated circuits, as well as automated tool and die production. The use trees of action items could be a very significant implement in all such operations. In addition, queues of items are very extensively used in all aspects of communications including the distribution of programs, documents and information packets of all varieties over the Internet, and the present invention could be of value in modifying items in such communications operations.
Although certain preferred embodiments have been shown and described, it will be understood that many changes and modifications may be made therein without departing from the scope and intent of the appended claims. For example, although the invention has been described with reference to modification of properties, the invention is also applicable to actions to be taken on child items which could be designated at the parent level. Such actions may involve the printing, deleting, etc. of documents, for example. | 4y
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FIELD OF INVENTION
The present invention relates in general to an articulated robot wrist.
BACKGROUND
A robot wrist is disclosed for example in European patent application EP 1938930 A1 and in European patent EP 2 022 609 B1.
SUMMARY
Disclosed herein are embodiments of an articulated robot wrist. One embodiment is of the type comprising a first body comprising a first and a second end, said first end of said first body being intended to be mounted on a robot component that is rotatable around a first axis. A second body comprises a first and a second end, said first end of said second body being rotatably mounted on said second end of said first body around a second axis inclined with respect to said first axis. A third body comprises a first and a second end, said first end of said third body being rotatably mounted on said second end of said second body around a third axis inclined with respect to said second axis. Said first and third axes are both substantially orthogonal to said second axis. In at least one position of said robot wrist, said first and third axes are substantially aligned to each other. Said first body comprises a substantially elbow-shaped portion having at its base a first opening which is directed towards said second and third bodies and which is substantially aligned to said first axis in the mounted condition of said wrist.
Said elbow-shaped portion carries an offset portion, substantially arranged side by side and spaced apart with respect to the axis of said first opening and on which there is provided said second end of said first body. Said second body comprises a cantilever portion, corresponding to said second end of said second body, which has a second opening substantially aligned to said third axis, in the mounted condition of said robot wrist said first and second openings being traversed by cables and/or tubes for the supply and/or control of a device associated to said third body of the robot wrist.
Said robot wrist can further comprise means for driving rotation of said second and third bodies, around said second and third axes, respectively. Said means for driving rotation of said second and third bodies comprises a first and a second motor carried by said offset portion of said first body, first gear means for transmission of the rotation of the output shaft of said first motor to said second body, and second gear means for transmission of rotation of the output shaft of said second motor to said third body.
The object of the present invention is that of improving a robot wrist of this type, in particular by providing a more compact structure and a simpler and more reliable kinematic chain. The object is achieved by providing a robot wrist having the features of claim 1 . The claims form integral part of the technical teaching which is provided herein with reference to the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be now described, purely by way of non-limiting example, with reference to the annexed drawings, in which:
FIG. 1 represents a perspective view of the robot wrist described herein;
FIG. 2 shows a cross-sectional view taken along the longitudinal sectional plane diagrammatically shown by line II-II in FIG. 1 ;
FIG. 3 shows a detail of FIG. 2 at an enlarged scale; and
FIG. 4 shows a further detail of FIG. 2 at an enlarged scale.
DETAILED DESCRIPTION OF EMBODIMENTS
In the following description various specific details are described in order to provide thorough understanding of the embodiments. The embodiments may be provided for example without one or more of these specific details, or through other methods, components or materials etc.
In other cases, known structures, materials or operations are not shown nor described in detail to avoid a bulky description of the various aspects of the embodiments. Therefore, references as used herein are only for convenience and do not define the scope of protection or the scope of the embodiments.
In the figures, reference numeral 10 designates an articulated robot wrist. As known in the art, a robot of this type is to be mounted on a robot component and is to be provided with a tool or other operating apparatus which is supplied and/or controlled with cables and/or tubes which are directly associated with the structure of the wrist itself. These cables and/or tubes are shown diagrammatically in the figures and designated by reference C. They define what is called the “harness” of the robot wrist, the robot wrist being defined as being “harnessed” once the cables and/or tubes have been mounted thereon. These aspects will not be discussed herein in detail, since they are per se conventional in the art and will be explained only to the extent which is necessary for describing the wrist of the invention.
Wrist 10 comprises a first body 12 including a first end 12 ′ and a second end 32 . The first end 12 ′ is to be mounted on a robot component (not shown) which is rotatable around a first axis IV.
Wrist 10 further comprises a second body 14 comprising a first end 42 and a second end 24 . The first end 42 is rotatably mounted on the end 32 of body 12 around a second axis V inclined with respect to the first axis IV. Furthermore, the robot wrist 10 comprises a third body 16 comprising a first end and a second end designated by reference 16 ″. As shown in the figures, preferably the third body 16 is an annular body which is to be traversed by cables and/or tubes of the tool associated to the wrist and whose end 16 ″ have a surface on which there are formed suitable seats for connection of this tool.
The first end of body 16 is rotatably mounted on the second end 24 of body 14 around a third axis VI inclined with respect to the second axis V.
Axes IV and VI form an angle substantially of 90 degrees with respect to the second axis V (in other words, axes IV and VI are both substantially orthogonal to axis V). As shown in the figures, in given positions in space of the robot wrist, these axes are substantially aligned with each other. In particular, the configuration shown in the figures is maintained for all the positions of the wrist which, with respect to that shown, are displaced only as a result of a rotation of the wrist around axis IV.
It is to be noted that in the present description, when reference is made to an orthogonal condition between two axes or straight lines, this may be applied both to the case of lines or axes which intersect each other and are perpendicular relative to each other, and to the case of lines or axes which do not intersect with each other but have their projections on a common plane parallel to them which form an angle substantially of 90 degrees relative to each other.
More specifically, the first body 12 comprises a substantially elbow-shaped body 18 which has, at its base, a first opening 20 facing towards the second body 14 and the third body 16 . In the mounted condition of the wrist, the opening 20 is substantially aligned with the first axis IV. Furthermore, the elbow-shaped portion carries an offset portion 22 , substantially arranged side by side, and spaced apart, with respect to the axis of opening 20 . On this offset portion the second body 14 is rotatably mounted around the second axis V. The second body has instead a cantilever portion 24 , corresponding to the above mentioned second end of the second body 14 , which has a second opening 26 substantially aligned with the third axis VI. In the mounted and harnessed condition of the robot, the first opening 20 and the second opening 26 are both traversed by cables and/or tubes C of the tool associated with the third body 16 . As visible from FIG. 1 , due to the general configuration which is defined by portions 18 and 22 , there is formed a passage for the cables and/or tubes C such that these cables and the tubes are held within the overall lateral dimension of the robot wrist, so as to avoid that they may interfere with the operations of the wrist itself. To this end, portion 22 further has a bracket 23 on its side facing the openings 20 , 26 , through which the cables and/or tubes are guided. This bracket has the function of constraining the cables and tubes to remain within the overall lateral dimension of portion 22 in the configurations of the wrist in which the second body 14 is rotated so that the opening 26 is displaced away from the condition aligned with opening 20 . Furthermore, in the mounted and harnessed condition of the robot, the cables and/or tubes C extend, for a portion of their length, substantially aligned with axis IV and, for another portion of their length, substantially aligned with axis VI. This condition provides a reduction to a minimum of the torsional and bending stresses to which the cables are subjected during the manoeuvres of the robot wrist.
In the robot wrist described herein, the means for driving the rotation of the second body 14 and the third body 16 are mounted directly on the structure of the wrist itself. In particular the driving means comprise a first motor 28 and a second motor 30 which are both carried by the offset portion 22 of the first body 12 . As will be described more in detail in the following, these driving means further comprise first gear means for transmitting the rotation of the output shaft of said first motor to said second body, and second gear means for transmitting the rotation of the output shaft of the second motor 30 to the third body 16 .
In the robot wrist described herein, at its end opposite to the elbow-shaped portion 18 , the offset portion 22 of the first body 12 has a fork-shaped portion 32 , corresponding to said second end of the first body. This fork-shaped portion 32 is arranged side by side, and spaced apart, with respect to the axis of opening 20 and the second body 14 is rotatably mounted thereon, around second axis V.
As will be seen herein in the following, this configuration of the offset portion enables the use of a kinematic chain for transmitting the movements from motors 28 and 30 , respectively to the second body 14 and the third body 16 , which is very simple and compact, the transmission of movement to the second and the third bodies being obtained through two different “routes”, with a resulting greater reliability of the entire kinematic chain.
In various embodiments, as well as in that shown in the figures, the first transmission means comprise a first shaft 34 rotatably mounted within a first arm 32 ′ of the fork-shaped portion 32 . As visible in FIG. 3 , the first arm 32 ′ has an opening 38 which is engaged by a plate 40 bolted to the edge of this opening, which has a central portion 40 ′ with a hole, adapted to rotatably support shaft 34 around the second rotational axis V, with the interposition of a bearing member 41 . As will be described more in detail in the following, shaft 34 is connected in rotation to the first motor 28 and is adapted to drive in rotation a second body 14 .
On their turn, the second transmission means comprise a shaft 36 rotatably mounted on the second arm 32 ″ of the fork-shaped portion, substantially in line with shaft 34 . As will be described more in detail in the following, the second shaft 36 is connected in rotation to the second motor 30 and is adapted to drive the third body 16 in rotation.
The second body 14 comprises a base casing 42 , corresponding to said first end of the second body, which is received within the space between the first and second arms of the fork-shaped portion and is rotatably supported thereby. More specifically, casing 42 has two opposite sides with a first opening 44 and a second opening 46 through which shaft 34 and shaft 36 are respectively received and rotatably supported with interposition of bearing members 53 and 56 . In particular, on the side of the second fork arm 32 ″, a bush 50 bolted to casing 42 engages the opening 46 and rotatably supports shaft 36 through bearing members 56 . The same bush 50 is rotatably supported by a bearing member 52 which is arranged on an opening 48 provided in the second fork arm 32 ″, opening 48 being substantially specularly arranged with respect to opening 38 of the first arm. The bearing member 52 acts also as an abutment member on one side of casing 42 and, similarly, a bearing member 55 , mounted on opening 38 of fork arm 32 ′, acts as an abutment member on the opposite side of this casing.
Casing 42 is driven in rotation by shaft 34 . In particular, between shaft 34 and casing 42 there is interposed a reducer means 58 which is supported by the bearing member 55 and is adapted to connect in rotation shaft 34 to casing 42 . The reducer means which has been shown in the figures is a harmonic reducer of a specific type which is conventionally used in the field of robots, and therefore it is not described herein in detail. In any case, it is clearly evident that the reducer means shown merely constitutes an example and in place thereof a reducer means of any other type conventionally used in this field may be adopted.
Casing 42 further contains transmission means (which will be described more in detail in the following) adapted to transmit rotation of second shaft 36 to further transmission members which are arranged within the cantilever portion 24 and are adapted to drive the third body 16 .
In various embodiments, as well as in that shown herein, inside the cantilever portion 24 the second body 14 comprises, a shaft 60 which is freely rotatably mounted around an axis parallel to the third axis VI. Shaft 60 is connected in rotation to said transmission means and on its turn transmits the rotation to the third body 16 . In particular, shaft 60 has a first end which carries a gear wheel 62 which is engaged by said transmission means and a second end opposite to the first end which carries a gear wheel 64 which engages a gear wheel 66 carried by the third body 16 . It is be noted that due to shaft 60 the third body 16 as well as the terminal part of portion 24 supporting the third body 16 can be positioned much forwardly with respect to the fork portion 32 , so as to allow a distance between second axis V and opening 26 of cantilever portion 24 that reduces to a minimum the torsional and/or bending stresses of the cables and/or tubes C through opening 26 , which may be due to the rotation of the second body 14 around second axis V.
In various embodiments, as well as in that shown herein, the transmission means indicated above comprise a shaft 68 which is rotatably mounted within casing 42 around an axis parallel to third axis VI and arranged on the opposite side with respect to shaft 60 . Shaft 68 has a first end with a bevel gear wheel 70 engaging a corresponding gear wheel carried by shaft 36 . Furthermore, this transmission means comprise a reducer means 74 which at its input is coupled to a second end of shaft 68 opposite to the above mentioned first end. At its output reducer means 74 is coupled to a gear wheel 76 which engages the gear wheel 62 carried by shaft 60 . The reducer means which has been shown in the figures is a harmonic reducer of a specific type which is conventionally used in the field of robots and therefore is not described in detail herein. In any case, it is clearly apparent that the reducer means shown herein constitutes only an example and in place thereof a reducer means of any other type conventionally used in this field may be adopted.
With reference now to FIGS. 2 and 4 , the first motor 28 and the second motor 30 are mounted inside offset portion 22 and substantially aligned with each other. The output shafts of motors 28 and 30 are connected to shafts 34 and 36 through respective belt transmissions. In particular, a bevel gear wheel 78 is secured to the output shaft of motor 28 and engages a bevel gear wheel 80 carried by a shaft 82 which is rotatably mounted within the offset portion 22 around an axis parallel and spaced apart from the second axis V. Shaft 82 has its end opposite to wheel 80 carrying a pulley 84 which is connected in rotation through a transmission belt 86 to a pulley 88 carried by shaft 34 . Similarly, on the output shaft of the second motor 30 there is secured a bevel gear wheel 90 which engages a bevel gear wheel 92 carried by a shaft 94 which is mounted in the offset portion 22 , on the side of this portion opposite with respect to shaft 82 . Shaft 94 is rotatable around an axis parallel and spaced from the second axis V. Shaft 94 has its end opposite to wheel 92 carrying a pulley 96 which is connected in rotation, through a transmission belt 98 , to a pulley 100 carried by shaft 36 .
In view of the foregoing, the transmission of movement to the second and third bodies, respectively in the rotations around axes V and VI, are obtained as described in the following.
When the first motor 28 is activated, shaft 82 is rotated, so as to drive rotation of shaft 34 through belt 86 . Shaft 34 transmits its movement to the reducer means 38 , which carries out a multiplication of torque, finally transmitting the rotation directly to the casing 42 of second body 14 .
Similarly, when the second motor 30 is activated, shaft 94 is rotated, so as to drive rotation also of shaft 36 through belt 98 . Shaft 36 drives rotation of shaft 68 , which transmits its movement to the reducer means 74 . The latter carries out a multiplication of torque, transmitting the movement to the gear wheel 76 . On its turn, wheel 76 rotates shaft 60 and wheel 64 , which, by engaging gear wheel 66 , finally drives rotation of the third body 16 .
It is to be noted that during the rotation of the second body 14 , shaft 68 is caused to oscillate with respect to shaft 36 . Due to the rotational connection between these two shafts, this oscillation would tend to rotate shaft 68 around its axis and then to cause an undesired actuation of the third body. In order to avoid this drawback, during the oscillation of shaft 68 the second motor 30 is controlled to rotate shaft 36 in a manner coordinated with this oscillation, so that shaft 68 does not rotate around its axis. Obviously, in cases in which a simultaneous actuation of the second and third bodies is requested, motor 30 is suitably controlled so that shaft 36 is able to transmit a rotation to shaft 68 corresponding to the desired movement for the third body.
It is finally to be noted that the above mentioned motors 28 and 30 have not been described herein in detail, since they can be of any type which is conventionally used in the field of robots. Similarly, some constructional details shown in the figures have not been described, to avoid an unnecessary complicated description, but they will be anyway clearly evident to the persons skilled in the art.
Naturally, while the principle of the invention remains the same, the details of construction and the embodiments may widely vary with respect to what has been described purely by way of non limiting example, without departing from the scope of the invention, as defined in the annexed claims. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to exercise apparatus, and in particular, to apparatus associated with a couch or other seating assembly.
2. Description of Related Art
With the wide recognition of the benefits of regular exercise, people have been increasing the opportunities to exercise by bringing exercise equipment into their homes. Conventional exercise equipment employs a frame having a system of cables and pulleys to lift an adjustable weight. The exerciser can stand or can rest on a seat or bench next to the frame in order to manually pull an end of the cable. Conventional exercise apparatus of the foregoing type are shown in U.S. Pat. Nos. 321,388; 4,372,553; 4,549,733; and 4,603,855.
With one known exercise machine, the exerciser stands between a pair of spaced frames. The exerciser can pull an opposing pair of cables on the frames to lift an adjustable weight with the cable system. A variety of exercises can be performed with this equipment, such as butterfly exercises. The cable can be routed in a bight around a reversing pulley attached to an adjustable weight. Thus the exerciser can pull either end or both ends of the cable to lift the adjustable weight.
A disadvantage with these exercise machines is the relatively large amount of floor space required by them. Many apartments and homes do not have a sufficient number of rooms or rooms large enough to accommodate such exercise machines. On the other hand, where the space is available a homeowner may find the exercise equipment aesthetically dissonant with the furnishings or decorations in the room where the exercise is to take place.
In U.S. Pat. Nos. 382,440 and 337,942 exercise machines having cable-lifted weights are mounted in tall boxes that are finished like furniture. While attractive, these devices are dedicated exercise machines and therefore still require the same amount of floor space as conventional exercise apparatus.
In U.S. Pat. No. 4,913,423 a chair is outfitted with cables that can be pulled by means of handles located atop the arms and the back of the chair. Similarly, a leg device can use cables pulled from the foot of the chair. This reference shows a double chair in FIG. 8. A disadvantage with exercise equipment of the foregoing type is the difficulty adjusting the effort level. The above exercise apparatus employs internal springs that establish the cable tension during exercise. This produces a tension that is not readily adjusted without disassembling the chair. Also, the tension on the exercise cable increases in accordance with the spring constant of the spring. In one embodiment of this known exercise device, a stack of adjustable weights are mounted in the back of the chair. Accordingly, the chair cannot be positioned against the wall, since the user will then be denied access to the weights for the purpose of adjustment.
U.S. Pat. No. 3,893,667 shows a small seat containing a system of springs that can be pulled from various directions by means of cables. Again, this reference has the disadvantages associated with springs.
U.S. Pat. No. 5,267,926 shows a chair that is fitted with exercise apparatus, including a pair of cables that can be used to lift weights. When installed on a chair, however, this apparatus interferes with use as an ordinary chair. See also U.S. Pat. No. 1,114,458.
U.S. Pat. No. 3,218,067 shows an exercise machine that is mounted in a headboard. This device uses elastic cables that can be wound onto a reel. This arrangement has the same disadvantage as the spring operated machines.
Elaborate and aesthetically unappealing apparatus mounted on beds are shown in U.S. Pat. Nos. 2,057,811 and 3,455,295.
Accordingly, there is a need for exercise apparatus that does not require a large amount of floor space and can be placed in room without upsetting its decor.
SUMMARY OF THE INVENTION
In accordance with the illustrative embodiments demonstrating features and advantages of the present invention, there is provided an exercise apparatus with a couch having a seating area sized to seat more than one person. The apparatus has an engagement means mounted at least partially inside the couch with a distal end adapted for reciprocation. Also included is an exercise means coupled to the engagement means for applying a force to the distal end in order to exercise one who reciprocates the distal end.
In accordance with another aspect of the invention, an exercise apparatus is provided with a seating assembly having a pair of side structures and a seating area between the side structures. Also included is a case mounted alongside one of the side structures of the seating assembly. The apparatus also has a cable routed through the seat assembly to the case. The cable has one end routed to emerge through the seat assembly for pulling exercises. The apparatus also has an adjustable weight mounted in the case and coupled to the cable to be lifted in response to pulling of the cable.
In accordance with still another aspect of the invention, an exercise apparatus is provided with a couch having a rear face, a pair of arms and a seating area between the arms sized to seat at least two people. The exercise apparatus also includes a cable that is routed through the couch to emerge from the couch near the arms for pulling exercises. Also included is an adjustable weight coupled to the cable to be listed in response to pulling of the cable. The adjustable weight is accessible in a region that is spaced from the rear face of the couch to avoid any need for clearance behind the couch in order to gain access to the adjustable weight.
By employing equipment of the foregoing type, an improved exercise apparatus is achieved. In the preferred embodiment exercise apparatus is associated with a couch. The assembly is built with a rectangular case mounted next to one arm of the couch. In this preferred embodiment the case is designed as a decorative column upon which a lamp may be placed. The case however, contains a adjustable weight that is lifted by a header that can roll on a pair of vertical tracks inside the case. The weights may be lifted by a cable system that is routed between the case and the couch. In other embodiments, the weights may be replaced with springs, elastomeric cords or other devices that can be stretched or deformed to provide muscle resistance to the exerciser.
In one preferred embodiment, a cable system terminates in a pair of attachment loops that protrude through openings on the inside of each of the arms of the couch. Handles or other exercise devices can be attached to these loops by clasps or the like. A stop, preferably mounted in the arms of the couch, can prevent the cable from retracting into the arm and getting lost.
The cable is preferably routed in two stretches from the two couch arms into the case. Inside the case, the cables may be routed under a pair of lower pulleys and over a pair of upper pulleys before they meet and loop a reversing pulley mounted on a header that holds the weights. Arranged in this preferred fashion, the two ends of the cable emerging from the couch arms can be used individually or together to lift the adjustable weight. The tension on the cable system can be changed, for example, by stacking a selectable number of weight plates on the header.
In one embodiment, an additional cable line can protrude from an end of the couch opposite the case. This additional cable line can protrude at a low elevation and can be used with a strap or other device for leg exercises.
BRIEF DESCRIPTION OF THE DRAWINGS
The above brief description as well as other objects, features and advantages of the present invention will be more fully appreciated by reference to the following detailed description of presently preferred but nonetheless illustrative embodiments in accordance with the present invention, when taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is an axonometric view of a exercise apparatus with its exercise features concealed and shown in the form of a couch with an adjoining stand;
FIG. 2 is an axonometric view of the apparatus of FIG. 1 with the door of the case removed and the couch arms uncovered to reveal the exercise features;
FIG. 3 is a side elevational view of the case of FIG. 2;
FIG. 4 is a rear elevational view, partly in section, of the case of FIG. 3;
FIG. 5 is a top plan view , partly in section, of the case of the FIG. 3;
FIG. 6 is an exploded, axonometric view of the couch arm shown next to the case in FIG. 2;
FIG. 7 is a detailed, exploded view of the pulley and stop of FIG. 6;
FIG. 8 is a schematic illustration of the pulley system of FIG. 2;
FIG. 9 is a schematic illustration of a pulley system of FIG. 8, shown with an additional cable line; and
FIG. 10 is an axonometric view of an exercise apparatus that is an alternate to that of FIGS. 1 and 2, employing an intervening end table and with its exercise mechanism shown in phantom.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, an exercise apparatus is shown employing a seating assembly in the form of a couch 10 having a pair of side structures, namely arms 12 and 14 . Couch 10 has a back 16 with a front and rear face. Couch 10 also has a seating area 18 between the arms 12 and 14 .
Next to arm 14 is a case 20 shown containing an adjustable weight in the form of a header 22 supporting a rod 24 . A selectable number of weight plates 26 are shown stacked on rod 24 . A cable C is shown mounted inside case 20 to follow a routing that will be described presently. Cable C is at times referred to as an engagement means, and weight 26 is also referred to as an exercise means.
While shown adjacent arm 14 , in other embodiments the case can be mounted adjacent arm 12 . While this case is rectangular, in other embodiments the case can be cylindrical, a polygonal prism, a frustrum of an ovoid, etc. Also, case 20 can be finished with an appropriate wood or plastic laminate or may be made of a fine wood that can be finished appropriately.
A handle 28 connected to one end of cable C is shown protruding inwardly from the inside face of arm 12 in FIG. 2 . In FIG. 1, the handle 28 has been detached from the cable and an arm cover 31 is shown concealing the opening for the cable in arm 12 . Another handle (to be described presently) and is associated with arm 14 .
Referring to FIGS. 3, 4 , and 5 , a header is shown as a rectangular palette 22 having on its right and left edges two pairs of wheels 30 . Wheels 30 roll within the pair of tracks 32 , which are channels mounted on opposing inside faces of case 20 . A rod 24 is shown angled slightly upwardly out from header 22 for the purpose of holding a stack of weight plates 26 .
A door 34 is shown hingedly attached to one corner of case 20 . In other embodiments door of the case can be positioned on various sides and can be hinged in various ways. Mounted opposite door 34 , inside case 20 is a vertical support beam 36 running the full height of the inside of case 20 . Mounted near the top, on opposite sides of beam 36 , are a pair of upper pulleys 38 . Mounted on opposite sides near the bottom of support beam 36 , are a pair of lower transition pulleys 40 . Transition pulleys 40 are mounted adjacent a pair of openings 42 along the bottom of the wall of case 20 , opposite door 34 . Journaled on the back of header 22 , opposite rod 24 is a reversing pulley 44 , used for a purpose to be described presently. While shown on the back of the header, this reversing pulley can be positioned on the front, top edge or elsewhere in other embodiments.
Referring to FIGS. 6 and 7, previously mentioned couch arm 14 is shown with its outside covering and padding removed, as well as one of its side panels, to reveal the mechanism inside the arm. The cap 42 is shown removed for illustrative purposes. Arm 14 is shown containing an internal beam 49 supporting an upper pulley 50 , and a lower pulley 48 .
Two stretches of cable C passing through the arm are shown as follows: stretch C 1 is shown passing through arm 14 to continue along the bottom of the couch. Stretch C 2 is shown passing under lower pulley 48 and over upper pulley 50 to pass through hole 52 before terminating in a cable loop 54 . Loop 54 is secured by means of U-bolt 56 that squeezes the end of the cable against the plate 58 using nuts 60 . With loop 54 secured in this fashion, it cannot be drawn into the arm 14 and lost. For this purpose, a U-shaped stop 62 is mounted on the bolt/axle 64 of upper pulley 50 . Accordingly, the hardware 56 / 58 cannot pass through the stop 62 and therefore loop 54 will remain exposed. Thus, handle 66 may be attached to loop 54 by using the clasp 68 at the inside end of the handle. Previously mentioned handle 28 (FIG. 2) is constructed and attached to cable C 1 in the same way.
Referring to FIGS. 8 and 9, cable C is shown routed over previously mentioned pulleys 38 , 40 , 44 , 48 and 50 . In FIG. 8, pulleys 38 and 40 are shown mounted on vertical beam 36 , while pulleys 48 and 50 are mounted on beam 49 inside one couch arm. In the opposite couch arm, vertical beam 70 is shown supporting an upper pulley 72 and a lower pulley 74 . Accordingly, beam 70 and its pulleys are structured in a manner similar to beam 49 and pulleys 48 and 50 .
In FIG. 8, cable C is shown traveling over and to the outside of pulley 72 before passing under lower pulley 74 . Thereafter, cable C passes through the couch (underneath the seating area 18 of the couch 10 of FIG. 1) to follow stretch C 1 . See also FIG. 6 . Stretch C 2 is shown, as before, passing over pulley 50 and under pulley 48 .
In FIG. 9, stretches C 1 and C 2 are shown passing under pulleys 40 and rising to pass over the top of upper pulleys 38 . Thereafter, stretches C 1 and C 2 join in a bight that passes under reversing pulley 44 , which can lift the weight header 22 . Pulley 44 is shown on the back of header 22 , but in other embodiments can be positioned at the front, the top edge, etc.
To facilitate an understanding of the principles associated with the foregoing apparatus, its operation will now be briefly described. The door 34 may be opened to expose the header 22 (FIGS. 1 and 2 ). The user can then place an appropriate number of weight plates 26 on the rod 24 of header 22 . Handles 28 and 66 may be stored on hooks (not shown) on the back of door 34 . Accordingly, door 34 functions as a means of storing exercise accessories, namely, handles 28 and 66 . The covers 31 on arms 12 and 14 may be removed to expose the loops on the ends of cable C. In FIG. 6 the handle 66 is shown with its clasp 68 adjacent to loop 54 . The clasp 68 can be opened and hooked around loop 54 in a conventional manner. Handle 28 (FIGS. 8 and 9) can be installed in a similar manner.
The user can then stand near or sit anywhere on couch 10 . For example, the user can sit next to one of the arms 12 or 14 to use one of the ends of cable C. Alternatively, the user can sit centrally on seating area 18 of couch 10 and pull on both ends of cable C, simultaneously.
Referring to FIGS. 8 and 9, when user pulls on handle 66 , stretch C 2 of cable C is pulled over pulley 50 and under pulleys 40 and 48 . Consequently, stretch C 2 of cable C is pulled over the top of one of the pulleys 38 to shorten the bight that is located between pulleys 38 and under reversing pulley 44 . Referring to FIG. 3, 4 and 5 , header 22 rises while its rollers 30 ride in the tracks 32 .
If handle 28 (FIG. 9) is pulled (instead of or simultaneously with handle 66 ) stretch C 1 of cable C is pulled over pulley 72 and under pulleys 74 and 40 . As a result, cable C is pulled over the top of one of the pulleys 38 to shorten the bight that is located between pulleys 38 and under reversing pulley 44 , to lift weight header 22 .
FIG. 9 illustrates an additional feature for alternate embodiments. Specifically, a line 76 is shown tied at point 77 along the stretch C 1 of cable C. Line 76 is shown traveling past the arm area containing pulleys 72 and 74 . In this embodiment line 76 emerges to the outside of the couch arm (arm 12 of FIG. 2 ). Line 76 is shown coupled to a leg exercising accessory 78 such as a leg bracelet or strap. Thus, a user may slip a foot into the accessory 78 . Since the line 76 emerges at a relatively low elevation, the user can readily exercise a leg by pulling with the leg on line 76 . The cable C can then lift the adjustable weight in a fashion similar to that described in connection with the pulling of handle 28 .
Referring to FIG. 10, previously mentioned couch 10 is shown again with arms 12 and 14 and seating area 18 . The previously mentioned cables loops and handles located at or in couch 10 are the same as before. The previously illustrated case is shown herein as alternate case 120 , which has been spaced from arm 14 by an intervening, rectangular end table 180 .
The case 120 contains the same mechanism as before, except reversed, right to left. Corresponding components have a reference numeral that was increased by one hundred over the correspondent. Accordingly, weight header 122 is shown mounted with its rod 124 pointing toward couch 10 . As a clear variation over the embodiment of FIG. 2, reversing pulley 144 is shown on the same side as the rod 124 . Pulleys 138 and 140 are shown mounted to the outside of case 120 .
Cable stretches C 1 and C 2 pass through end table 180 to pass under pulleys 140 and over pulleys 138 , before joining in the bight located between pulleys 138 and under reversing pulley 144 . Routed in this fashion, the cable C can lift the adjustable weight in essentially the same manner as with the other embodiment.
The exposed faces of case 120 are closed. One can gain access to header 122 and rod 124 for the purpose of adding weights, by lifting the top 182 of end table 180 . No wall exists at the intersection between table 180 and case 120 . Therefore, the user can add or remove weights from rod 124 through end table 180 .
It will be appreciated that still other modifications may be implemented with respect to the above described, preferred embodiments. In some embodiments the adjustable weight may be formed from a horizontal stack of weight plates that may be connected by a pin to a vertical rod depending from a header. In other embodiments, the weights may be replaced with springs, elastomeric cords or other devices that can be stretched or deformed to provide muscle resistance to the exerciser. The couch may have various, aesthetically pleasing shapes and design features in other embodiments. While the ends of the cables are shown connected to handles, other grasping devices can be used such as pulling bars, cloth loops etc. While a loop and clasp is shown for connecting the handle to the cable end, in other embodiments the handle may be permanently attached from alternate fastening means. In other embodiments, the reversing pulley on the header can be mounted on a different elevation or can be mounted along the top edge of the header. In still other embodiments, the header can be an open frame made of various components that are fastened together by bolts, welding, etc. The size, dimensions and shape of the couch and the adjacent case can be altered depending upon the desired seating capacity, weight capacity, pulling range, aesthetic considerations, etc.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present invention is a Continuation-In-Part of U.S. application Ser. No. 09/968,393 entitled “NETWORK-BASED PHOTOSHARING ARCHITECTURE” (2215P/P214) filed on Oct. 1, 2001, which is assigned to the Assignee of the present application and herein incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to electronic storage and sharing of digital images, and more particularly to an improved photosharing architecture.
BACKGROUND OF THE INVENTION
[0003] Over the past several years, photosharing has become widely accepted by photo enthusiasts. Many websites currently exist that allow users to upload digital images to the site for storage on a server and for viewing by others over the Internet. Metadata, which is typically associated with an image or group or images, is typically supported by photosharing sites. One of the most significant inhibitors of photo sharing on the Web today, however, is the lack of privacy available for the images and their associated metadata.
[0004] There are currently several available options for sharing images on the web today. One option is for a user or a small group of users to build their own site for sharing, and restrict access to the site through the traditional access control mechanisms available. This can be costly and is beyond the skills of most people, however. Further, there is currently no efficient mechanism that allows a user to search for images across more than one of these “private” sites.
[0005] Another option is for individuals and groups to host their own images on some of the current peer-to-peer networks, such as Yaga™ without incurring great cost or requiring significant technical expertise in setting up and maintaining a web site. Some of these peer-to-peer systems provide limited support for searching using a small set of fixed metadata fields. However, the images discoverable on the current peer-to-peer networks are public as are their metadata, so access is available to all users on the system.
[0006] A further option is for users and small user groups to share their images using a traditional web-based photosharing services. These services offer a limited amount of privacy. Through traditional access control mechanisms, a user or group can specify who may see the images and associated metadata. Some of these sites provide search facilities that allow searching on the limited amount of metadata they support. The current photosharing services, however, have possession of both the images and metadata (copies of them, at least). In this sense, the images and metadata are not private. In fact, the user agreements for most of these sites take little responsibility for keeping the images and metadata private, in most cases specify that once the images have been uploaded to the photosharing site, both the images and the metadata become the property of the photosharing site.
[0007] Accordingly, there is a need for a system that allows users and groups to share images and restrict access to the images and metadata. Further, the system should allow users to execute searches that span more than one private image storage site in a manner that restricts access to the images and data according to the image owner's wishes. The present invention addresses such a need.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] [0008]FIG. 1 is a block diagram illustrating a network-based photosharing system in accordance with a preferred embodiment of the present invention.
[0009] [0009]FIG. 2 is a block diagram illustrating the contents of the central site peer server.
[0010] FIGS. 3 - 5 are flow charts illustrating three processes for searching for resources located throughout the system using metadata, while at the same time ensuring the privacy of private metadata on the peer nodes.
SUMMARY
[0011] The present invention is a method for executing searches for resources that span more than one private resource repository in a restricted-access resource sharing system. The system includes at least one server node and multiple peer nodes connected to a network. Resources, such as data digital images, may be retrieved from the nodes based by issuing queries containing terms matching the metadata associated with the resources. The method includes maintaining storage of resources and associated metadata on respective peer nodes, wherein the associated metadata is based on at least one metadata vocabulary. Each of the peer nodes is allowed to indicate to the server that the metadata vocabularies associated with the resources are designated as private, thereby becoming a restricted access peer node. If a first restricted access peer node specifies to the server which metadata vocabularies the first restricted access peer node supports, a first level of privacy is provided whereby search queries received by the server that use the specified metadata vocabularies are passed to the first respective restricted access peer nodes for processing, while searches that do not use the specified vocabularies are processed by the server. If the first restricted access peer node does not specify to the server which metadata vocabularies the first restricted access peer node supports, a second level of privacy is provided whereby search queries received by the server are passed to the first respective restricted access peer nodes for processing.
[0012] According to the method and system disclosed herein, the present invention provides users with a way to maintain privacy of their metadata, while allowing searches for images based on that metadata to be performed across all the nodes in the system.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The present invention relates to a method and system for providing a web-based, peer-to-peer photosharing service. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiments and the generic principles and features described herein will be readily apparent to those skilled in the art. Thus, the present invention is not intended to be limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and features described herein.
[0014] The present invention will be described in terms of a preferred embodiment where the targets to which the metadata is applied are digital images, although the metadata may be applied to any type of digital resource.
[0015] Co-pending application Ser. No. 09/968,393 provides a web-based, peer-to-peer photosharing service in which all workstations and computers in the network store their own images and act as servers to other users on the network. The photosharing service includes at least one central server, known as the peer server, that is available to users through client computers or peer nodes. The photosharing service allows users to maintain storage of their images on their own computers, and enables users and their guests to search for images across the other user's peer nodes based on a wide array of metadata supported by the system. The advantage of the service is that it frees users from having to setup their own independent photosharing site, solves storage problems encountered by photosharing service providers, and also solves photosharing usability problems encountered by users of the service.
[0016] [0016]FIG. 1 is a block diagram illustrating a peer-to-peer (P2P) photosharing system in accordance with a preferred embodiment of the present invention. According to the present invention, the system 10 includes a central photosharing website 12 that includes a peer server 14 , and multiple peer nodes 16 . The peer server 14 and each of the peer nodes 16 are capable of communicating with one another over a network, such as the Internet. In a preferred embodiment, users 18 may also access the central site 12 from devices or clients (not shown) that are not peer nodes 16 , via the use of a standard web browser.
[0017] In a preferred embodiment, the peer nodes 16 may each represent either a website or a computer, and typically store the digital images 20 of a particular user 18 . Although the user interface for the peer nodes 16 may be implemented in a number of different ways, in a preferred embodiment the peer user interface is implemented as a web browser, but alternately it may be an application specifically designed for the system 10 . Each peer node 16 may store the images 20 of more than one user. For example, two family members which share a home PC, but manage their images separately may maintain separate accounts with the system 10 on the shared PC. The digital images 20 are stored as image files that include image data. Each image also has metadata 22 associated with it that describe and categorize the image. The metadata 22 may be associated with the images 20 by the user 18 or automatically by the peer node 16 as described below. In addition, some or all of the metadata 22 may be associated with the image 20 by a digital camera at the time of image capture. Each image 20 may also be associated with a particular type of metadata, which is a smaller representation of the image data, called a thumbnail image 24 .
[0018] The photosharing service 10 is in contrast to the traditional photosharing model where the user 18 would post digital images by uploading the images from his or her computer to a webserver for storage in a static album. Instead, in the previous embodiment, the photosharing service 10 , the peer nodes 16 maintain storage of the actual image data and only the metadata 22 (and, in particular, the thumbnail image 24 ) for each image are uploaded to the peer server 14 . This allows users to construct queries that search through the metadata 22 stored at the peer server 14 to find images 20 of interest (or groups of images, albums, sound clips, movies, whatever has metadata).
[0019] For example, users 18 may dynamically create image albums 26 for viewing the images 20 by submitting search criteria that are based on metadata 22 . In FIG. 1 for example, assume that user 18 a has shared images 20 on the central site 12 by uploading the metadata 22 to the peer server 14 . User 18 b may then submit a search to the peer server 14 to view images 20 having metadata that matches the search criteria. In response, the peer server 14 returns a list of image locators (e.g., URLs) for images 20 matching the search criteria to peer node 16 b , and the peer node 16 b sends requests using the image locators to retrieve the matching images as needed.
[0020] One drawback with caching the metadata 22 on the server 14 where the searches are performed is that users 18 loose control over their metadata 22 . The present invention solves this problem by providing the photosharing system 10 with an extension that allows a peer node 16 or a group of peer nodes 16 to store images 20 and metadata 22 without caching any metadata 22 including thumbnails at the peer server 14 . This extension also enables users to search for images 20 on one or more of these peer nodes 16 using metadata vocabularies associated with these private images, as described below.
[0021] According to the present invention, the owner of a peer node has two levels of privacy that he/she can use to maintain privacy of his/her metadata 22 and images 20 . In both levels of privacy, the images 20 and metadata 22 are not cached on the peer server 14 , and the peer node 16 indicates to the server 14 that the peer node 16 contains private metadata 22 and images 20 . In the first level of privacy, the peer nodes 16 indicate to the peer server 14 which metadata 22 vocabularies the image 20 it stores makes use of. In the second level of privacy, the peer server 14 has no knowledge of which metadata 22 vocabularies the image 20 on the peer node uses, providing a higher level of security for the peer node.
[0022] [0022]FIG. 2 is a block diagram illustrating the contents of the central site peer server 14 . In a preferred embodiment, the peer server 14 includes a web server application 50 , a metadata vocabulary library 52 , a user and group account database 54 , and a cache 56 .
[0023] The web server application 50 serves pages formatted to suit the capabilities of the peer node 16 . The web server application 50 includes a form-driven user interface 66 that provides users 18 with an easy and intuitive way to define custom metadata vocabularies 84 without specifying the syntax for knowing the underlying schema language.
[0024] The metadata vocabulary library 52 is for storage and management of metadata vocabularies 84 or schemas. The vocabulary library 52 stores both custom metadata vocabularies 84 created by the users 18 , as well as actual metadata values associated with specific images 22 and uploaded from client computers 16 .
[0025] In a preferred embodiment, the vocabulary library 52 includes a universal schema, shared schemas, and private schemas, which in a preferred embodiment are defined using RDF and XML. All images 20 in the system 10 are required to have associated with them metadata 22 specified by the universal schema. Each metadata vocabulary 84 specifies the metadata properties in that vocabulary and specifies constraints that must be enforced in order to comply with the vocabulary. Users 18 and groups are allowed to define their own schemas, which may include the universal schema and may borrow from other vocabularies 84 .
[0026] The cache 56 is used to store the metadata 22 associated with frequently accessed images 20 to provide for quicker searches. The metadata 22 may be automatically replaced in the cache 56 with the metadata 22 from other images 20 based on the peer server's configured caching policies.
[0027] The user and group account database 54 stores user account and corresponding contact information and preferences of each registered user 18 . Groups of users may also share common policies, which may include permission settings, UI options, required and optional metadata vocabularies, subscriptions lists, event/notification policies, and caching policies.
[0028] The user account database 54 allows mandatory vocabularies 84 to be associated with certain target resources. For example, a particular user 18 may want all of his individual photographs to have a certain set of metadata 22 always supplied. His/her account would be configured to indicate the assignment of metadata supporting the relevant metadata vocabulary 84 is required before the image 20 may be stored on the system 10 . An example of required metadata, might be a vocabulary 84 for data about the owner of the account (e.g., name, address, etc). Multiple vocabularies 84 may be required for any given target types.
[0029] Digital still Images 20 need not be the only type of target resources. Examples of other types of image files for which required vocabularies may be specified include multiple image files, such as timelapse images, burst images, panorama images, etc. Non-image target resources may also be supported, such as sound files, movies, and text documents. The present invention applies to any resource that could conceivably have metadata associated with it.
[0030] It should be noted that use of the vocabulary library 52 is not required to implement the present invention, but is preferred. In this case, each user account record includes the necessary information needed to support two levels of privacy.
[0031] According to a preferred embodiment of the present invention, each user account record maintained by the peer server 14 includes a private data vocabulary list 90 and a private search indicator 92 . The private data vocabulary list 90 identifies which metadata vocabularies 84 the peer node 16 makes use of. For each metadata vocabulary 84 listed, the user account would also include a list of corresponding properties (not shown).
[0032] The private search indicator 92 is used to indicate whether or not the user wishes to reveal which metadata vocabularies 84 are used by the images stored on the user's peer node 16 . In a preferred embodiment, the private search indicator 92 is a Boolean that is set to (TRUE) if the peer node 16 maintains private metadata 22 , and is set to (FALSE) if the peer node's metadata 22 is public. In the case where the private search indicator 92 is TRUE, indicating private metadata 22 , the user of the peer node has the option of using one of two levels of privacy to protect their private metadata 22 .
[0033] In the first level of privacy, the peer node 16 is specifies to the peer server 14 which metadata vocabularies 84 the peer node supports (i.e., which vocabularies 84 are used by the images 20 on the peer node 16 ). Search queries received by the peer server 14 that use these vocabularies 84 are then sent to the peer node 16 and the peer node 16 handles the search, while searches that don't contain properties from the vocabularies 84 supported by a peer node 16 are processed by the server 14 . While some privacy is lost in the first level, the benefit is improved performance because searches that don't contain properties from vocabularies supported by a peer node 16 are not sent to the peer node 16 for processing.
[0034] In the second level of privacy (the higher level), the peer node 16 does not specify to the peer server 14 which metadata vocabularies 84 peer node 16 supports. In this case, the private data vocabulary list 90 maintained on the server for the user of the peer node 16 will be empty, and the server 14 will pass all searches that pass the traditional access control filters passed to the peer node 16 for processing.
[0035] FIGS. 3 - 5 are flow charts illustrating three different techniques for searching for resources located throughout the system 10 using metadata, while at the same time ensuring the privacy of private metadata on the peer nodes 16 . FIG. 3 illustrates a first embodiment of a general private metadata search and retrieval process where both the requesting peer node 16 and the peer nodes 16 being searched may or may not be protected by firewalls. In this embodiment, the requesting peer node 16 may be any electronic device having a web browser or client application. FIGS. 4 and 5 illustrate alternative embodiments for the private metadata search and retrieval process that provide the same functions as that shown in FIG. 3, but provide optimizations when certain firewall conditions are met. These processes may yield better performance than the general method illustrated in FIG. 3.
[0036] Referring now to FIG. 3, the process for enabling private metadata searches begins with the peer server 14 presenting a screen(s) to the peer node 16 that allows a user to construct a search query in step 102 to locate a desired image or other resource in the system 10 . Preferably, the peer server 14 displays a list of metadata vocabularies 84 supported by the system 10 for user selection. In step 104 , the user constructs the search query by selecting which metadata vocabularies 84 to use in the search, selecting properties of interest corresponding to those vocabularies, and by supplying values for the selected properties that the system 10 will attempt to find matches for.
[0037] In response to the user finishing construction of the query, the peer node 16 submits the query to the peer server 14 in step 106 . As shown in FIG. 3, the peer server then performs three separate activities (in any sequence or in parallel) in steps 108 , 114 , and 120 , which are the initial steps in each of these three respective activities.
[0038] The first activity begins in step 108 , where the peer server 14 searches the metadata cache 56 containing metadata 22 sent to it by the peer nodes 16 . For each resource which matches the query string and to which the querying user has authorization to access, the peer server 14 creates a resource locator in step 110 that the requesting peer node 16 will use to access the resource. In step 112 , the peer server 14 waits for the three activities begun in steps 108 , 114 , and 120 to complete.
[0039] The second activity begins in step 114 , where the peer server 14 searches the user account records 54 to find peer nodes 16 that maintain private metadata 22 , and that have specified which metadata vocabularies 84 their resources (e.g., images) make use of. In step 116 , the peer server 14 matches the search query against the listed vocabularies 84 . When the peer server 14 finds a user account record with a match, the peer server sends the query to the corresponding peer node 16 for final processing in step 118 .
[0040] The third activity begins in step 120 , where the peer server 14 locates all user account records 54 that indicate private metadata 22 is supported, but have not identified any metadata vocabularies 84 to the peer server 14 . For each matching user account 54 , the peer server 14 sends the query to the corresponding peer nodes 16 for processing in step 118 .
[0041] Each peer node 16 , which receives the search query, searches its private metadata 22 database for matching resources in step 122 . For each matching resource, the peer node 16 creates a resource locator in step 124 , and returns it to the peer server 14 in step 126 . The peer server 14 waits for these responses in step 112 . In an alternative embodiment, the peer node 16 that processed the search query could return any resource locators directly to the peer node 16 that requested the search, assuming that the peer server 14 sends the URL of the requesting peer node 16 to the other peer nodes 16 when passing the search query.
[0042] When the peer server 14 receives all the responses to the query from the peer nodes 16 for (or the requests timeout) in step 112 , the peer server 14 sends the resource locators for all the matching resources to the requesting peer node 16 in step 128 . The requesting peer node 16 then uses the received resource locators to retrieve the desired data.
[0043] Note: To completely hide any information returned from the peer nodes 16 , the peer nodes 16 must encrypt their responses. In a preferred embodiment this is done using a public key associated with the requesting peer node 16 . This key can be obtained by the peer nodes 16 in a number of ways. In a preferred embodiment, the requesting peer node 16 sends the key to the peer server 14 along with the search query. The peer server 14 then sends the key to each peer node 16 it forwards the query to. In another embodiment, public keys could be stored in a well-known location from which the peer nodes 16 can retrieve it. Examples of such well-known repositories are LDAP directories, a certificate authority such as Versign, and the peer server 14 itself. Each peer node 16 would encrypt its responses to query requests. These requests can only be unencrypted with the requesting peer node's private key.
[0044] [0044]FIG. 4 is a flow chart illustrating a second embodiment for the private metadata search and retrieval process, which is optimized for peer nodes 16 unprotected by firewalls. Like the process illustrated in FIG. 3, this process functions despite the presence of firewalls protecting the peer nodes 16 . This process, however, in most cases will provide better performance for peer nodes 16 that are not behind firewall than the method illustrated in FIG. 3, but the requesting peer node 16 may or may not be behind a firewall. The search and retrieval process provides additional privacy in that query responses are not routed through the peer server 14 , rather the responses are sent directly to the requesting peer node 16 . It may also provide better performance than queries processed by the process of FIG. 3 in cases where the peer server 14 is processing a great deal of requests and responses. Data encryption in this method can be provided by methods most commonly used today (e.g., SSL connections).
[0045] The search and retrieval process of FIG. 4 begins with the system 10 presenting a user 18 with a screen(s) that allows the user 18 to construct a query in step 202 . In step 204 , the user 18 constructs the search query by selecting the metadata vocabularies 84 to use, selecting the properties of interest, and supplying values for the properties that the system 10 will attempt to find matches for. In response to the user finishing construction of the query, the peer node 16 submits the query to the peer server 14 in step 206 . The peer server 14 then performs three separate activities (in any sequence or in parallel) in steps 208 , 214 , and 220 , which are the initial steps in each of these three respective activities.
[0046] The first activity begins in step 208 , where the peer server 14 searches the metadata cache 56 containing metadata 22 sent to it by the peer nodes 16 . For each resource which matches the query string and to which the querying user has authorization to access, the peer server 14 creates a resource locator in step 210 that the requesting peer node 16 will use to access the resource. In step 212 , the peer server 14 waits for the three activities begun in steps 208 , 214 , and 220 to complete.
[0047] The second activity begins in step 214 , where the peer server 14 searches the user account records 54 to find peer nodes 16 that maintain private metadata 22 , and have specified which metadata vocabularies 84 their resources (e.g., images) make use of. In step 216 , the peer server 14 matches the search query against the listed vocabularies. When the peer server 14 finds a record with a match it builds a peer node locator containing the query sent by the requesting client in step 218 .
[0048] In step 220 , the peer server 14 locates all peer node account records that indicate they support private metadata 22 and where the vocabularies 84 have not been identified to the peer server 14 . When peer server 14 finds a record for a peer node 16 having vocabularies 84 containing properties matching those in the search query, the peer server 14 creates respective peer node locator pointing to each of those peer nodes 16 and embeds the query in the peer node locators in step 218 .
[0049] After finishing constructing all the peer node locators with the embedded query in step 218 , the peer server 14 provides the peer node locators to the waiting process of step 212 .
[0050] When the peer server 14 receives all the peer node locators (or the requests timeout) in step 212 , the peer server 14 sends the peer node locators to the requesting peer node 16 in step 222 . In step 224 , the requesting peer node 16 then uses the returned peer node locators to send the query to the peer nodes 16 identified in the resource locators. (Note: peer nodes 16 behind firewalls could be supported by indicating in each peer node locator that the query should be routed through a Peer Proxy).
[0051] In response to receiving one of the resource locators, each peer node 16 searches its metadata database to find resources that match the query in step 226 . For each matching resource found, the peer node 16 creates a peer node locator in step 228 . In step 230 the peer node returns any created peer node locators to the requesting peer node 16 . Finally, in step 232 the requesting peer node 16 uses the peer node locators to retrieve the resources and presents the results of the query to the user.
[0052] [0052]FIG. 5 is a flow chart illustrating a third embodiment for the private metadata search and retrieval process, which is optimized for peer nodes protected by firewalls. While this process is operational for both peer nodes 16 that are, and are not, protected by firewalls, the process provides no real benefit over the process in FIG. 4 for peer nodes 16 that are not protected firewalls. The requesting peer node 16 may or may not be protected a firewall. Like the process in FIG. 4, this process provides additional privacy over the process shown in FIG. 3 in that query responses are not routed through the peer server 14 . It may also provide better performance than queries processed by the method in FIG. 3 in cases where the peer server 14 is processing a great deal of requests and responses. Data encryption in this method can be provided by methods most commonly used today (e.g., SSL connections).
[0053] The search and retrieval process begins the same as the previous two embodiments with a screen being presented to the user 18 (step 302 ) and the user 18 constructing a search query (step 304 ). Once the requesting peer node 16 submits the query to the peer server 14 (step 306 ), the peer server 14 performs the three activities initially started in steps 308 , 316 , and 322 .
[0054] The first activity begins in step 308 , where the peer server 14 searches the metadata cache 56 containing metadata 22 sent to it by the peer nodes 16 . For each resource which matches the query string and to which the querying user has authorization to access, the peer server 14 creates a resource locator in step 310 that the requesting peer node 16 will use to access the resource. In step 312 the peer server 14 sends all the resource locators to the requesting peer node 16 .
[0055] The second activity begins in step 316 , where the peer server 14 searches the user account records 54 to find peer nodes 16 that maintain private metadata 22 , and that have specified which metadata vocabularies 84 their resources (e.g., images) make use of. In step 318 , the peer server 14 matches the search query against the listed vocabularies. When the peer server 14 finds a user account record with a match, the peer server 14 forwards the query to the corresponding peer node 16 along with a resource locator for the requesting peer node 16 in step 320 .
[0056] The third activity begins in step 322 , where the peer server 14 locates all user account records 54 that indicate private metadata 22 is supported, but have not identified any metadata vocabularies 84 to the peer server 14 . For each matching user account 54 , the peer server 14 sends the query to the corresponding peer nodes 16 along with a resource locator for the requesting peer node 16 in step 320 .
[0057] Each peer node 16 , which receives the search query, searches its private metadata 22 database for matching resources in step 324 . For each matching resource, the peer node 16 creates a resource locator in step 326 . In step 328 , each peer node 16 using the resource locator of the requesting peer node 16 received from the peer server 14 establishes a network connection with the requesting peer node 16 . Each peer node 16 uses this connection to send the resources locators it has created to the requesting peer node 16 . The connection is left open to allow the requesting peer node 16 to make requests, if needed.
[0058] In step 314 , the requesting peer node 16 collects all the resource locators from the peer server 14 and peer nodes 16 . After the requesting peer node 16 either receives all resource locators or a timeout period expires, the requesting peer node 16 uses the resource locators to retrieve the data needed to present the results of the query to the user.
[0059] A peer-to-peer photosharing service has been disclosed that maintains privacy over user metadata and images. The present invention has been described in accordance with the embodiments shown, and one of ordinary skill in the art will readily recognize that there could be variations to the embodiments, and any variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims. | 4y
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FIELD OF THE INVENTION
[0001] The present invention relates to internal combustion engines, and more particularly to engine control systems that control engine operation in a displacement on demand engine.
BACKGROUND OF THE INVENTION
[0002] Some internal combustion engines include engine control systems that deactivate cylinders under low load situations. For example, an eight cylinder engine can be operated using four cylinders to improve fuel economy by reducing pumping losses. This process is generally referred to as displacement on demand or DOD. Operation using all of the engine cylinders is referred to as an activated mode. A deactivated mode refers to operation using less than all of the cylinders of the engine (one or more cylinders not active).
[0003] In the deactivated mode, there are fewer cylinders operating. As a result, there is less drive torque available to drive the vehicle driveline and accessories (e.g., alternator, coolant pump, A/C compressor). Engine efficiency, however, is increased as a result of decreased fuel consumption (i.e., no fuel supplied to the deactivated cylinders) and decreased engine pumping. Because the deactivated cylinders do not take in air, overall engine pumping losses are reduced. During typical engine operation in the deactivated mode, the engine is switched to the activated mode when the torque demand is greater than a threshold (e.g., approximately 95%) of the maximum torque available in the deactivated mode.
[0004] During the course of normal driving, there are many operating conditions just above the threshold of the deactivated mode torque limit. As a result, there are multiple occurrences of switching to the less fuel efficient activated mode. Once in the activated mode, hysteresis often delays transition back into the deactivated mode. These conditions result in missed opportunities to reduce fuel consumption.
SUMMARY OF THE INVENTION
[0005] Accordingly, the present invention provides an engine control system for controlling engine operation in activated and deactivated modes in a displacement on demand (DOD) engine. The engine control system includes an impulse charging device that is disposed upstream of an intake port of a cylinder of the DOD engine and that is operable to regulate air flow into the cylinder. A first module initiates impulse charging to regulate air flow into the cylinder when a desired engine torque output nears a first threshold engine torque output during engine operation in the deactivated mode.
[0006] In one feature, the impulse charging device inhibits air flow into the cylinder for a portion of an intake event.
[0007] In another feature, the impulse charging device includes a high-speed valve that is operable in an open position to enable air flow therethrough and a closed position to inhibit air flow the reth rough.
[0008] In still other features, the engine control system further includes a second module that switches engine operation to the activated mode when the desired engine torque nears a second threshold engine torque during engine operation in the deactivated mode with impulse charging. The second module switches engine operation to the deactivated mode when the desired engine torque is below the first threshold engine torque minus a hysteresis value.
[0009] In yet another feature, the first module ceases impulse charging when the desired engine torque is below the first threshold engine torque.
[0010] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein:
[0012] FIG. 1 is a functional block diagram illustrating an exemplary vehicle powertrain including a displacement on demand (DOD) engine system having an impulse charging system according to the present invention;
[0013] FIG. 2A is a schematic cross-section of a cylinder of the engine including an impulse charging valve in a closed position;
[0014] FIG. 2B is the schematic cross-section of the cylinder of the engine including the impulse charging valve in an open position;
[0015] FIG. 3 is a flowchart illustrating the impulse charging control according to the present invention;
[0016] FIG. 4 is an exemplary graph illustrating torque increase achieved using the impulse charging control of the present invention;
[0017] FIG. 5 is a logic diagram illustrating exemplary modules that execute the impulse control of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. For purposes of clarity, the same reference numbers will be used in the drawings to identify similar elements. As used herein, activated refers to operation using all of the engine cylinders. Deactivated refers to operation using less than all of the cylinders of the engine (one or more cylinders not active). As used herein, the term module refers to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
[0019] Referring now to FIG. 1 , a vehicle 10 includes an engine 12 that drives a transmission 14 . The transmission 14 is either an automatic or a manual transmission that is driven by the engine 12 through a corresponding torque converter or clutch 16 . Air flows into the engine 12 through a throttle 13 . The engine 12 includes N cylinders 18 . One or more of the cylinders 18 are selectively deactivated during engine operation. Although FIG. 1 depicts four cylinders (N=4), it is appreciated that the engine 12 may include additional or fewer cylinders 18 . For example, engines having 4 , 5 , 6 , 8 , 10 , 12 and 16 cylinders are contemplated. Air flows into the engine 12 through an intake manifold 20 is directed to the cylinders 18 through runners 22 and is combusted with fuel in the cylinders 18 .
[0020] Referring now to FIGS. 1, 2A and 2 B, the engine further includes impulse charging devices 24 located within respective intake runners 22 associated with respective cylinders 18 . Although two impulse charging devices 24 are illustrated, it is appreciated that more or fewer impulse charging devices 24 can be implemented. The impulse charging devices 24 selectively inhibit air flow from the intake manifold into its respective cylinder, as discussed in further detail below. More specifically, each impulse charging device 24 includes a high-speed valve 26 . During normal engine operation, the valve 26 remains open and has very little effect on air intake into the cylinders 18 . In an impulse charging mode, the valve 26 is closed during most of the intake event. As a result, there is a low pressure or vacuum within the cylinder 18 and along the intake runner 22 downstream of the impulse charging device 24 .
[0021] The valve 26 is rapidly opened at a predetermined time towards the end of the intake event and an inrush of air produces a supercharging effect within the cylinder 18 . In this manner, the air pressure above the piston is increased over a traditional intake event. The valve 26 is closed and a positive pressure wave produced by the inrush of air is captured. At the beginning of the subsequent intake event, the positive pressure wave functions to eliminate exhaust residuals. In the impulse charging mode, the torque output of the engine can be increased as much as 20% at lower engine speeds.
[0022] A control module 38 communicates with the engine 12 and various inputs and sensors as discussed herein. An engine speed sensor 48 generates a signal based on engine speed. An intake manifold absolute pressure (MAP) sensor 50 generates a signal based on a pressure of the intake manifold 20 . A throttle position sensor (TPS) 52 generates a signal based on throttle position.
[0023] When light engine load occurs, the control module 38 transitions the engine 12 to the deactivated mode. In an exemplary embodiment, N/2 cylinders 18 are deactivated, although one or more cylinders may be deactivated. Upon deactivation of the selected cylinders 18 , the control module 38 increases the power output of the remaining or activated cylinders 18 . The inlet and exhaust ports (not shown) of the deactivated cylinders 18 are closed to reduce pumping losses.
[0024] The engine load is determined based on various engine operating parameters including, but not limited to, the intake MAP, cylinder mode, impulse charging mode and engine speed. More particularly, engine load is expressed as the percent of maximum available engine torque. For purposes of discussion, engine torque will be used in the foregoing discussion. If engine torque is below a threshold level for a given RPM, the engine load is deemed light and the engine 12 is operated in the deactivated mode. If engine torque is above the threshold level for the given RPM, the engine load is deemed heavy and the engine 12 is operated in the activated mode. An exemplary threshold level is 95% of maximum available torque (T DEAC ). The control module 38 controls the engine 12 based on the impulse charging control to maintain engine operation in the more fuel efficient regions and to extend the time during which the engine 12 operates in the deactivated mode.
[0025] The impulse charging control of the present invention regulates engine operation in the impulse charging mode concurrent to the engine operating in the deactivated mode. More particularly, there is a maximum available engine torque when operating in the deactivated mode (T DEAC ). When the torque demand on the engine (T DES ) exceeds a threshold torque (T THR ) (e.g., 90%-95% of T DEAC ), the deactivated cylinder mode engine is concurrently operated in the impulse charging mode. Impulse charging while operating in the deactivated mode provides an increased available engine torque (T DEACIC ) (i.e., T DEAC <T DEACIC ). In general, a torque increase of up to approximately 20% can be achieved (e.g., T DEACIC =(1.2)T DEAC ).
[0026] T THR correspondingly increases to provide a second threshold (T THRIC ) when operating in the concurrent deactivated and impulse charging modes. Using an exemplary value of 95%, T THR would be approximately equal to 0.95*T DEAC in the deactivated mode T THRIC would be approximately equal to 0.95*T DEACIC in the deactivated mode with impulse charging. Because T DEACIC is greater than T DEAC , T THRIC in the deactivated mode with impulse charging is greater than T THR in the deactivated mode without impulse charging. Engine operation switches to the activated mode when the T DES exceeds T THRIC . More specifically, when T DEACIC is insufficient to provide T DES , engine operation is switched to the activated mode. T DES is determined based on driver demand (e.g., accelerator pedal position).
[0027] Referring now to FIG. 3 , exemplary steps executed by the impulse charging control will be described in detail. In step 100 , control determines whether to transition to the deactivated mode. If control determines not to transition to the deactivated mode, control loops back. If control determines to transition to the deactivated mode, control deactivates select cylinders 18 in step 102 .
[0028] In step 104 control monitors T DES . Control determines whether T DES exceeds T THR in step 106 . If T DES does not exceed T THR , control ends impulse charging if it is currently active in step 108 and loops back to step 104 . If T DES exceeds T THR , control initiates impulse charging in step 110 . In step 112 , control determines whether T DES exceeds T THRIC . If T DES does not exceed T THRIC , control loops back to step 104 . If T DES exceeds T THRIC , control ends impulse charging activity and activates all cylinders (i.e., switches to the activated mode) in steps 113 , 114 and ends.
[0029] Referring now to FIG. 4 , exemplary torque curves versus engine speed are illustrated for the impulse charging control. An exemplary DOD range for the deactivated mode is defined from approximately 950 RPM to approximately 2900 RPM. T DEAC (in phantom) indicates the torque curve during normal engine operation in the deactivated mode. The T DEACIC (in solid) indicates the torque curve during engine operation in the deactivated mode with impulse charging. A significant torque increase is achieved by concurrent operation in the deactivated mode and impulse charging modes, enabling the engine to remain in the deactivated mode for an extended period.
[0030] Referring now to FIG. 5 , the logic flow of the impulse charging control will be described in detail. A cylinder mode module 500 receives engine operating parameters including torque and RPM signals, and generates a cylinder activation or deactivation signal based thereon. The cylinder activation or deactivation signal is sent to a cylinder actuator module 502 and a torque module 504 . The cylinder actuator 502 deactivates or activates selected cylinders based on the activation or deactivation signal. The torque module 504 monitors the available torque output of the engine in comparison to T DES . The torque module 504 generates an impulse charging control signal if T DES is nearing T THR . The impulse charging control signal is sent to an impulse charging module 506 , which regulates operation of the impulse charging devices 24 .
[0031] Those skilled in the art can now appreciate from the foregoing description that the broad teachings of the present invention can be implemented in a variety of forms. Therefore, while this invention has been described in connection with particular examples thereof, the true scope of the invention should not be so limited since other modifications will become apparent to the skilled practitioner upon a study of the drawings, the specification and the following claims. | 4y
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PRIORITY CLAIM
[0001] The present application is a continuation of U.S. application Ser. No. 12/583,087, entitled “Method of Synchronization for Low Power Idle,” filed on Aug. 11, 2009, now U.S. Pat. No. 8,270,389, which claims the benefit of U.S. Provisional Patent Application No. 61/188,717, entitled “Method of Synchronization for Low Power Idle” and filed on Aug. 11, 2008. Both of the above-referenced applications are hereby incorporated by reference herein in their entireties.
FIELD OF THE INVENTION
[0002] This invention relates to communication devices and systems, and in particular, to a method and apparatus for low power idle synchronization.
RELATED ART
[0003] Efforts are being made to develop a standard for energy efficiency in Ethernet. This enhancement will reduce power consumption in networks, such as for example Ethernet networks, when the link utilization is low. Low link utilization occurs when little or no data is being transmitted by the link.
[0004] As proposed in the prior art, power consumption is reduced in the following manner: When no data is ready to be transmitted by one side of the link, that side signals to the other side that is entering the lower power mode. Then, after a period of time the transceiver can power down its transmitting circuits. The receiver on the other side detects the sleep signal and can then power down its receiving circuits. Together this can save close to 50% of the power consumed maintaining the full-duplex link. If no data is ready to be transmitted in either direction then the transmitting and receiving circuits on both sides of the link can be powered down (this is known as symmetrical mode). When data is ready to be transmitted the relevant transmitter sends an alert signal that triggers the receiver to wake up to re-establish the link. This low power state is known as LPI (Low Power Idle) or EEE (Energy Efficient Ethernet) mode.
[0005] While this prior method of EEE mode reduces power consumption, it suffers from several drawbacks. One such drawback is that the master and slave may become out of sync during lower power mode. For example, 10GBASE-T devices, which operate under the Ethernet standard, contain a number of adaptive systems that maintain integrity during the low power mode to ensure that the transition back to full data mode is error free. This is particularly a concern for the timing recovery circuits which during loop timing mode the ‘slave’ transceiver recovers timing from the ‘master’. During the quiet period the clocks can drift apart since the slave is unable to update its timing state to maintain synchronization with the master since there is no signal transmitted. As a result, this clock drift can inhibit operation of the receiver since the sampling time is no longer optimal and ISI (inter-symbol interference) increases, which degrades the link quality. This reduces the SNR (signal to noise ratio) at the receiver, and can increase the rate at which incorrect decisions are made at the receiver's slicer or decision device as well as increasing the BER (bit error rate) in the device. In turn this reduces the accuracy of the adaptive filters used to cancel the various kinds of interference. This causes errors on the link and in the worst case it can cause the link to retrain, meaning that no data can be transferred for several seconds.
[0006] The innovation disclosed herein overcomes these drawbacks and provides additional benefits.
SUMMARY
[0007] In one embodiment, a method comprises receiving, at a receiver, data from a transmitter. The data is received via an Ethernet link, is modulated according to a first modulation scheme, and is received while the receiver is in a first mode. The first mode corresponds to a first power consumption level of the receiver. The method also includes, after receiving the data, receiving, at the receiver, a sleep signal from the transmitter, and, in response to receiving the sleep signal, transitioning the receiver to a second mode. The second mode corresponds to a second power consumption level of the receiver that is lower than the first power consumption level. The method also includes, after transitioning to the second mode, detecting, at the receiver, an expiration of a predetermined time interval, and, in response to detecting the expiration of the predetermined time interval, transitioning the receiver to a third mode. The third mode corresponds to a third power consumption level of the receiver that is greater than the second power consumption level. The method also includes, after transitioning to the third mode, receiving, at the receiver, a refresh signal from the transmitter. The refresh signal is modulated according to a second modulation scheme different than the first modulation scheme. The method also includes synchronizing the receiver to the transmitter based on the refresh signal, and, after synchronizing the receiver to the transmitter, transitioning the receiver back to the second mode.
[0008] In another embodiment, a device comprises a receiver configured to receive, from a transmitter coupled to the receiver via an Ethernet link, data while the receiver is in a first mode. The first mode corresponds to a first power consumption level of the receiver. The data is modulated according to a first modulation scheme. The receiver is also configured to, after receiving the data, receive a sleep signal from the transmitter, and, in response to receiving the sleep signal, transition to a second mode. The second mode corresponds to a second power consumption level of the receiver that is lower than the first power consumption level. The receiver is also configured to, after transitioning to the second mode, detect an expiration of a predetermined time interval, and, in response to detecting the expiration of the predetermined time interval, transition to a third mode. The third mode corresponds to a third power consumption level of the receiver that is greater than the second power consumption level. The receiver is also configured to, after transitioning to the third mode, receive a refresh signal from the transmitter. The refresh signal is modulated according to a second modulation scheme different than the first modulation scheme. The receiver is also configured to synchronize to the transmitter based on the refresh signal, and, after receiving the refresh signal, transition back to the second mode.
[0009] In another embodiment, a method comprises generating, at a transmitter, data modulated according to a first modulation scheme, and transmitting, via the Ethernet link, the data to a receiver while the transmitter is in a first mode. The first mode corresponds to a first power consumption level of the transmitter. The method also includes, after transmitting the data to the receiver, transitioning the transmitter to a second mode. The second mode corresponds to a second power consumption level of the transmitter that is lower than the first power consumption level. The method also includes, after transitioning the transmitter to the second mode, detecting, at the transmitter, an expiration of a predetermined time interval, and, in response to detecting the expiration of the predetermined time interval, transitioning the transmitter to a third mode. The third mode corresponds to a third power consumption level of the transmitter that is greater than the second power consumption level. The method also includes generating, at the transmitter, a refresh signal that (i) is to be used by the receiver to synchronize to the transmitter, and (ii) is modulated according to a second modulation scheme different than the first modulation scheme, and, after transitioning the transmitter to the third mode, transmitting, from the transmitter, the refresh signal to the receiver via the Ethernet link. The method also includes, after transmitting the refresh signal to the receiver, transitioning the transmitter back to the second mode.
[0010] In another embodiment, a device comprises a transmitter configured to generate data modulated according to a first modulation scheme, and transmit, via an Ethernet link, the data to a receiver while the transmitter is in a first mode. The first mode corresponds to a first power consumption level of the transmitter. The transmitter is also configured to, after transmitting the data to the receiver, transition to a second mode. The second mode corresponds to a second power consumption level of the transmitter that is lower than the first power consumption level. The transmitter is also configured to, after transitioning to the second mode, detect an expiration of a predetermined time interval, and, in response to detecting the expiration of the predetermined time interval, transition to a third mode. The third mode corresponds to a third power consumption level of the transmitter that is greater than the second power consumption level. The transmitter is also configured to generate a refresh signal that (i) is to be used by the receiver to synchronize to the transmitter, and (ii) is modulated according to a second modulation scheme different than the first modulation scheme, and, after transitioning to the third mode, transmit the refresh signal to the receiver via the Ethernet link. The transmitter is also configured to, after transmitting the refresh signal to the receiver, transition back to the second mode.
[0011] Other systems, methods, features and advantages of the invention will be or will become apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. In the figures, like reference numerals designate corresponding parts throughout the different views.
[0013] FIG. 1 illustrates an example environment of use having two communication transceivers.
[0014] FIG. 2 illustrates an example timing diagram for transition to idle of one example embodiment.
[0015] FIG. 3 illustrates an example embodiment of a low power idle (LPI) system configured to establish timing for refresh signals and present refresh signals to the channels.
[0016] FIG. 4 illustrates an exemplary timing diagram of transition between the XGMII and the PMA modules.
[0017] FIG. 5A illustrates how XGMII code words are converted to signaling on the wire.
[0018] FIG. 5B illustrates timing diagram of a master slave refresh period assignment after PAM 2 training.
[0019] FIG. 6 illustrates an exemplary timing diagram for a 4 channel communication system configured for duplex operation.
[0020] FIG. 7 illustrates an echo response resulting from an exemplary refresh signal.
[0021] FIG. 8 illustrates a timing diagram between PHY A transceiver and PHY B transceiver relative to a PAM 16 transition.
DETAILED DESCRIPTION
[0022] FIG. 1 illustrates an example environment of use between two communication transceivers. This is but one possible environment of use and as such, it is contemplated that other environments of use may also adopt the teachings disclosed herein. As shown, a first transceiver 104 includes a transmitter 108 and a receiver 112 . The transmitter 108 comprises a PCS 116 and a PMA 118 . The PCS (physical coding sublayer) encodes the data from an upper layer, such as a MAC layer, and adds framing information and redundancy to aid in error detection and correction. The operations performed by the PCS 116 facilitate frame recovery and error correction decoding at an opposing receiver.
[0023] The output of the PCS 116 feeds into the PMA (physical medium attachment) 118 . The PMA 118 is responsible for converting the digital data to a format and signal type suitable for transmission over a communication channel or cable 130 . A THP (Tomlinson-Harashima precoder) (not shown) may be located within the PMA 118 . An analog front end (AFE) (not shown) may be located between the PMA 118 and the channel 130 .
[0024] This example embodiment also includes the receiver 112 having a PMA 122 and a PCS 120 . Likewise, the opposing transceiver 134 includes a receiver 138 and transmitter 142 , each having a PMA 144 , 148 and PCS 146 , 150 as shown. Operation for each element is as described above. It is contemplated that this example environment may be embodied in an Ethernet communication system communicating over 4 twisted pair conductors. One of ordinary skill in the art is versed on the environment and apparatus of an Ethernet based network communication device and hence this environment is not discussed in detail.
[0025] FIG. 2 illustrates an example timing diagram of one example embodiment. In contrast to the prior art that would enter an indefinite sleep state until awaken by an activate signal, the method and apparatus disclosed herein established a predetermined timing protocol to establish periods during which a refresh signal is generated and sent to a corresponding timed and recently activated receiver.
[0026] As shown in FIG. 2 , during a period 209 the communication system is engaged in active data exchange. During a period 208 the communication system enters an idle mode 208 wherein the communication system continues to transmit over the channel, but does so with packets and frames containing idle control data or other information to maintain synchronization of the communication devices. After a period of idle 208 , the transmitter enters into LPI (low power idle) state 210 . This period comprises a period when the transmitter and receiver are synchronously powered down to reduce power consumption.
[0027] It is contemplated that powering down as many components and subsystems as possible will occur to increase the amount of realized power consumption. In one embodiment, during the LPI state, one or more of the following components are powered down: echo cancellers, next (near end crosstalk) cancellers, fext (far end cross talk) cancellers, equalizers, timing recovery, DACs (digital to analog converters), ADCs (analog to digital converters), AFEs, and PGAs.
[0028] After a predetermined period of time or predetermined counter value the transmitter and corresponding receiver awake for a refresh period 212 . During the refresh period 212 the receiver awakes just prior to the refresh signal when the transmitter transmits, for a short period, idle or other type information sufficient for the transmitter to maintain synchronization with the receiver and for the receiver to adapt its filters, equalizers and clock to the transmitter. Over time, the clock, which synchronizes the transmitter to the receiver and guides slice and decision operations, can drift if synchronization does not occur. This results in the transmitter's master clock being unsynchronized from the receiver, which results in decoding and slicing errors. After a refresh period 212 , the transmitter and receiver return to LPI mode 210 until the next predetermined refresh period.
[0029] The refresh signals may comprise any type data to achieve clock synchronization and filter/equalizer adaptation. In one embodiment the refresh signals comprises idle packets. In one embodiment the refresh signal is a predefined pseudo-random PAM 2 sequence. Refresh signals may be PAM 2 coded, PAM 16 coded, or any other coding scheme.
[0030] Upon the transmitter receiving data to be transmitted from upper layers, such as the MAC, the transmitter sends an alert/wake sequence. The alert sequence is detected by a simple low-power circuit and wakes the rest of the receiver from the low power mode. The wake sequence 216 instructs the receiver to return to active data mode. After wake code is received and processed, the system returns to active data communication in period 220 . Through the use of periodic refresh signals at predetermined refresh periods or times, clock synchronization is maintained and the filters/equalizers are likewise adapted.
[0031] Therefore, to limit the loss due to the timing offset, while in LPI mode the transmitter and receiver wake up periodically and data is transferred between them, with the aim to keep the coefficients in adaptive filters and timing loops up to date.
[0032] The EEE mode can operate asymmetrically (one side of the link is in LPI/EEE quiet/refresh cycling, the other is in full data mode) or symmetrically (both sides of the link are in LPI/EEE quiet refresh cycling).
[0033] In symmetrical mode greater power savings can be attained since both the transmitting and receiving parts of the transceiver can be powered down for relatively long periods of time. To maximize power savings the refresh signals for the master-transmitted signal and the slave-transmitted signal are synchronized so that they do not overlap. This alignment minimizes/eliminates overlap between the near and far-end signals after they have been dispersed by the channel response. This allows the adaptation of echo/next (near end crosstalk) filters and equalization/FEXT (far end crosstalk) filters to be separated which provides the greatest opportunity for power savings. Achieving this alignment is important to achieve maximum power savings.
[0034] Overlap is unwanted because when a refresh signal is set from the transmitter, it creates an echo which is reflected back into the system. To cancel this echo would require powering and operation of the echo canceller, which consumes power. Since one of the goals of the present invention is to reduce power consumption, it is preferred to minimize operation of the echo canceller. By avoiding or preventing overlap, a refresh signal will not be received at a transmitting transceiver, thereby avoiding need for the echo canceller.
[0035] FIG. 3 illustrates an example embodiment of a low power idle (LPI) system configured to establish timing for refresh signals and present refresh signals to the channels. This is but one possible example embodiment and it is contemplated that one of ordinary skill in the art may arrive at different embodiments without departing from the scope of the claims that follow. This example embodiment is shown in a four channel embodiment typical of network based Ethernet operating over twisted pair copper.
[0036] In this embodiment an XGMII presents a signal to a PAM 2 generator 304 , a PAM 16 PCS_coded signal generator 308 , and an LP_Idle Detector 312 and an idle detector 310 . The PAM 2 LFCR generator 304 generates PAM 2 signals for use during training and during refresh. In the 10Gbit standard, training occurs within a 2 second time period utilizing PAM 2 coded training sequences. Training includes clock synchronization, and establishment of filter, precoder, and equalizer coefficients. After training, the system transitions to PAM 16 coding at a 10gigabit rate. It is contemplated that during refresh periods that PAM 2 signals, PAM 16 signals, or any other format may be utilized for synchronization and adaptation.
[0037] The PAM 16 PCS coded signal generator 308 processes the input from the XGMII to generate PAM 16 coded frames. It is contemplated that the data may be encoded using a technique known as DSQ (double square constellation). PAM 16 coding is understood by one of ordinary skill in the art of 10 Gigabit Ethernet and is not discussed in detail herein. The XGMII output is also presented to the LP_Idle (LPI) detector 312 .
[0038] The idle detector 310 has an output which connects to the refresh generator 320 . The idle detector 310 detects idles, such as codes or frames, in the XGMII data that follow LP_idles. At this transition the PHY will terminate transmit lower power mode and begin to send the alert sequence followed by the wake signaling. The idle detector 312 monitors for the idle signal from the XGMII when the XGMII enters the normal idle state. The output from the idle detector 312 is utilized to detect a transition from the lower power mode. This signals the transmitter that it should transition to the normal mode of operation by sending the alert and wake signals, followed by normal data.
[0039] The output of the PAM 2 generator 304 and the PAM 16 coded signal generator 308 connect to a multiplexer 316 . The multiplexer 316 also received a control signal from a refresh generator 320 which selectively controls which input signal is output from the multiplexer 316 . The multiplexer 316 comprise any device capable of selectively outputting one of multiple inputs signals on its outputs. Although shown as a multiplexer, it is contemplated that other devices, such as switches, control logic, and the like, may be utilized instead. Through control of the multiplexer 316 , either the PAM 2 signal or the PAM 16 signal may be output to downstream portions of the transmitter shown in FIG. 3 .
[0040] An LP_idle detector 312 provides an input to the refresh generator 320 to assist in the refresh generator providing the control signal to the multiplexer 316 . The LP_idle and idle codeword detectors are used to time transitions to and from the lower power mode using sleep and wake signals.
[0041] Also input to the refresh generator 320 is a transmit LDPC frame counter 324 and a receiver LDPC frame counter 328 . In one embodiment, these counters comprise 9 bit counters which cycle at 512 count value. The frame counters 324 , 328 are activated at the start of the transition from PAM 2 to PAM 16 or synchronized with another counter or event. These frame counters 324 , 328 maintain a continual count and these counts are utilized by the system of FIG. 3 for timing the refresh signal exchange. In one embodiment, the counters generate a count and periodically at fixed predetermined times values during the counter value sequence, refresh periods are predetermined so that refresh signals are transmitted and received. To increase power savings, while also maintaining synchronization and adaptation, because refresh signals are periodically sent, based on predetermined times or counter values so that the receiver may remain in sleep mode until the predetermined refresh period and does not need to monitor the channel. FIG. 6 discussed this in greater detail.
[0042] The output of the multiplexer 316 is presented to the channels A-D as shown and in particular to a multiplexer 330 A- 330 D associated with each channel as shown. The alternative inputs to the multiplexer 330 are zero inputs that are also used to reset the delay line within the THP. The multiplexer may also be used to control AFE/DAC for power savings. A channel specific control input is also presented to the multiplexers 330 to control which input is presented on the multiplexer output. It is contemplated that during LPI (low power idle) mode the output from the multiplexers 330 may comprise a zero output, or either of the PAM 16 signal or a PAM 2 signal. It is also contemplated that any channel A-D may be independently controlled as to when its predetermined time period to enter LPI mode and conduct a refresh operation will occur. In one embodiment this is controlled by the LDPC counter values based on a predetermined timing or scheduling scheme, but in other embodiments, other factors or means may control the timing of the refresh periods.
[0043] The output of the multiplexers 330 feed into Tomlinson Harashima precoders 334 A- 334 D. In other embodiments, different precode operations may occur, or precoding may be omitted. The output of the precoders 334 is presented to DA converters 338 A- 338 D which modify the format of the outgoing signals to an analog format suitable for processing by an analog front end and eventual transmission over a channel.
[0044] In operation, the XGMII outputs data or control information to the PAM 2 signal generator 304 , the PAM 16 coded signal generator 308 , and the LP_Idle detector 312 . During training the PAM 2 generator generates a PAM 2 coded signal which is output to the multiplexer 316 and routed through the transmitter to the channel. Training occurs as is understood in the art. At the end of training, the system transitions from PAM 2 coding to PAM 16 coding to achieve a higher effective data transmit rate. At this transition the LDPC counters are initiated. These counters run continually during operation of the communication device and are synchronized with system operation.
[0045] After a period of inactivity, the XGMII may send an idle control code which is control code that is PAM 16 coded, just like data, to maintain the communication link. After a period of idle from the XGMII, the communication system may transition into LPI mode. This transition to LPI (LPI) mode may be the result of commands from upper layers or from the XGMII itself, or one or more idle frame counters. In one embodiment, uppers layers generate and output a special control character defined as a low power idle character. Upon receipt of this LPI character, entry into LPI mode occurs.
[0046] To initiate LPI mode, the operation monitors for a code or other signaling from the XGMII. In one embodiment, each channel, and each master and slave associated with a channel, is assigned a predetermined LDPC frame counter value at which it will send and/or receive refresh signals. In one embodiment, a transmitter associated with a channel may enter sleep mode at any time after entry to idle, but refresh periods are set by the LDPC frame counter values.
[0047] After entry into LPI mode, the multiplexer 330 associated with the channel entering LPI mode is controlled to output a zero output. One or more control signals from a controller, processor, or control logic may be configured to output a power down signal to these elements. In addition, other aspects of the channel may be shut down or enter a low power mode to reduce power consumption. This includes, but is not limited to the THP 334 , the DAC 338 , PMA, PCS, an analog front end including amplifiers and drivers, and the PAM 16 and PAM 2 encoders. Likewise, the receiver components may also be shut down or enter low power mode to reduce energy consumption. These components include but are not limited to equalizers, echo and NEXT cancellers, FEXT cancellers, ADC, PGA, LCPC decoders, or any other device. By shutting one or more of these devices down or entering low power mode, power savings is realized.
[0048] During LPI mode, the system monitors the LDPC frame counter for a count value associated with and designating a predetermined refresh period for that channel. Upon occurrence of the predetermined LDPC frame counter value, the transmitter and corresponding remote receiver awake for a refresh period. At this time, the refresh generator 320 provides a control signal to output from the multiplexer 316 either of the PAM 2 or PAM 16 signal, which are processed in the normal course to achieve clock synchronization and adaptation of the equalizers and filters. It is contemplated that the remote receiver may awake slightly before the refresh signal so that is prepared for the incoming refresh signal. Then, a refresh signal is sent from the transmitter to the receiver. The refresh signal is processed by the receiver to update the clock synchronization and to adapt the equalizers and filters.
[0049] After the refresh signal is sent and synchronization and adaptation occurs, the system re-enters sleep mode to reduce power consumption. To re-enter sleep mode the multiplexer 330 is controlled to output zero values and the desired components are powered down or enter low power mode.
[0050] When the upper layers have data to transmit, the system must exit LPI mode. To exit LPI mode the XGMII provides data to the PAM 16 generator 308 and the LP_Idle detector 312 . The data request is detected and a wake signal is sent to the corresponding receiver. This wake signal restores the receiver and transmitter to active data mode and data communication occurs.
[0051] It is contemplated that in one embodiment a portion of the receiver does not sleep, so that it can detect the alert sequence which signals that the wake signal will follow. In such an embodiment, when the transmitter sees XGMII signaling that indicates IDLE signals, it begins to move from the low power mode to the normal operational mode. In this embodiment, the first step is to transmit an alert sequence, which is a predefined sequence of non-precoded PAM 2 symbols. The alert sequence is followed by the wake sequence which is PAM 16 /DSQ data (encoded IDLE codegroups). As such, in this embodiment a small part of the receiver that detects the PAM 2 sequence is always on during the lower power mode and when it detects the PAM 2 alert sequence it turns on the rest of the receiver in time to receive all or part of a wake sequence and the receiver is then ready to receive normal data immediately after the wake sequence. In an alternative embodiment, the receiver remains in sleep mode until a refresh period, at which time it listens for an alert sequence. The transmitter would likewise only send an alert sequence during the refresh period. If refresh periods are not spaced too great a time period apart, this delay would not be noticeable to a user.
[0052] FIG. 4 illustrates an exemplary timing diagram of the transition between the XGMII and the PMA modules. As shown in FIG. 4 , an output of the XGMII comprises data 404 and the corresponding output from the PMA output is coded data. When the XGMII transitions to idle (no upper layer data to transmit), the PMA continues to output data, but is designated as idle data 410 by control codes.
[0053] After a period of idle 408 by the XGMII, the XGMII transitions to low power idle 412 . The detection of the low power idle 412 causes the PMA to output a sleep signal 414 , and the transition to quiet period 416 . It is contemplated that during this quiet period 416 , the transmitter and opposing receiver may enter LPI state to reduce power consumption and realize power savings.
[0054] When the XGMII has upper layer data to transmit, it may output either idle or data information 418 . In one embodiment it first sends an easy to detect and decode PAM 2 signal, which may or may not be precoded. Then idle signals are encoded in PAM 16 , which comprise the wake signal, followed by data.
[0055] FIG. 5B illustrates timing diagram of a master slave pair post PAM 2 training. In symmetrical mode LPI/EEE for 10GBASE-T, it is possible to synchronize the master and slave transceivers so that the master's refresh-quiet cycle is half a cycle away from the slave's refresh-quiet cycle. This provides numerous benefits. One such benefit is that it prevents overlap of the refresh signals. In addition, increases power reduction while maintaining clock synchronization.
[0056] Sleep mode is signaled by the transceiver sending LP_IDLE codewords to the link partner. The LP_IDLE codewords are detected at the end of the link partner's receive path, after signal processing and error correction.
[0057] One major impediment to achieving the optimal symmetric refresh-quiet synchronization is that if both transceivers try to enter the low power idle around the same time. For example, the alignment must be established by the link partners with little training time and no prior knowledge of the link partner timing. Neither side knows when the other will decide to enter sleep. Thus, it is possible that the transceivers enter sleep simultaneously, in which case some mechanism is required to determine which link partner should be used as the refresh reference. This is shown in FIG. 5A . This is further complicated by the unknown latencies of the link itself as well as the transmit path and the receive path (which are likely to vary by implementation), since the second transceiver does not detect the sleep signal exactly when the first transceiver decides to transmit it.
[0058] Resolving this alignment is difficult without a complex handshaking and synchronization scheme using the sleep signal. To date, no solutions exist to this problem. The requirements for 10GBASE-T EEE are different to the requirements for previous generations of Ethernet.
[0059] A solution as disclosed herein is to use symmetrical sleep signaling so that the slave waits longer than the master before transitioning into the refresh-quiet cycle. While this is one possible solution, this solution would add complexity and extreme care must be taken with boundary conditions.
[0060] The requirements for 10GBASE-T are higher than for other Ethernet standards since the data rate is much higher and there is the receivers are more complex. A similar refresh-quiet signaling is not used for 1GBASE-T/100BASE-TX PHYs.
[0061] Another solution to the synchronization problem uses a reference available to both sides, instead of requiring that the last transceiver to transition adjust its quiet refresh cycle with respect to the link partner. The following disclosed one possible embodiment of a solution based on this principle. In other embodiments variations to this solution will be contemplated by one of ordinary skill in the art.
[0062] 10GBASE-T transceivers have about 2 seconds to train and exchange information before they transition to the full data mode. During this time the transceivers train using a PAM- 2 constellation. Once the PHYs enter data mode the transceivers send each other data using a PAM- 16 constellation. The data is contained in LDPC frames, which last for 256 symbols on each pair.
[0063] During PAM- 2 training the PAM- 2 signal on pair A inverts at 256 symbol intervals, at the LDPC boundary. The signal also contains one 16-octet infofield every 16384 PAM- 2 symbols. The infofield includes a countdown field that expires when the transmitting PHY transitions from PAM- 2 training data to PAM- 16 data mode. Together these values can be used by the slave to identify the exact 800 MHz symbol when the master transitions to data mode.
[0064] FIG. 5B illustrates timing diagram of a master slave refresh period assignment after PAM 2 training. In this example embodiment, the slave uses the master's infofield countdown to start a local counter at the start of the master's PAM- 16 data-mode 540 . This countdown may start at exactly the start of the master's PAM- 16 data-mode or at another time referenced from the start of the master's PAM- 16 data-mode. The counter increments at the start of LDPC frame 544 and provides both sides with a timing reference with respect to the master (the counters may be offset by the latency of the link, which is unknown). The time for the refresh signal is known as T r 548 . The quiet period is known as T q 552 . The complete cycle time is known as T C . Each of these periods is an integer multiple of the LDPC frame time T f . Although link latency is not known, it is defined by a maximum value or can be measured, so latency can be accommodated in this LPI system by accounting for the maximum potential or actual latency.
[0065] The master sends a refresh 556 timed to k.T C at the boundary of a refresh-quiet cycle timed with respect to the master's transition to data-mode. The slave knows exactly when the refresh signal will appear at its receiver. Each refresh is transmitted on a fixed pair derived using simple modulo logic. For example, in one embodiment, the refresh on pair A is transmitted when the refresh active signal is high and the LDPC frame counter modulo 4T C is less than T C , the refresh on pair B is transmitted when the refresh active signal is high and the LDPC frame counter modulo 4T C is between T C and 2T C . The slave is able to derive the timing of the refreshes it receives through similar modulo logic based on the receive LDPC frame counter.
[0066] In this embodiment, the slave sends a refresh 560 timed to k.T C +0.5×T f ; exactly halfway into the master's refresh-quiet cycle, timed with respect to the master's transition to data-mode at the slave. The signal is guaranteed not to overlap with the master's refresh signal since the latency, in this embodiment, of the link is bounded to 570 ns (802.3 an standard paragraph 55.7.2.5). It is contemplated that T q may be much greater than 570 ns. The master is able to derive the timing of the refreshes it receives through similar modulo logic based on the receive LDPC frame counter.
[0067] In this scheme the master can detect the first slave refresh signal to recover the exact alignment (since the latency of the link is an unknown parameter).
[0068] It is also contemplated that another solution is for the slave to extend the LPI sleep signal (LP_IDLE) to the next refresh boundary to give an absolute reference to the master, but this could be a complete quiet time away, which reduces power savings and as such may not be as desirable.
[0069] It is contemplated that the LPI system may operate in symmetric or asymmetric modes. Power savings may be maximized when either transceiver in a transceiver pair may independently enter LPI mode. For example, during a network operation requiring downloading of data from a remote server, one transceiver may be continually transmitting the data to the requesting transmitter, but the requesting transceiver may only periodically transmit acknowledgment signals. During these quiet periods between the transmission of the acknowledgement signals, the requesting transceiver may enter LPI mode. It is contemplated that the time from idle to entry into LPI may be short, thereby providing for power savings since only a short period time would pass in idle mode before LPI state occurs.
[0070] FIG. 6 illustrates an exemplary timing diagram for a 4 channel communication system configured for duplex operation. This figure illustrates an exemplary timing and spacing scheme for refresh signals on each bi-directional pair. The vertical axis 604 represents each pair's transmitter for PHY A 612 and PHY B 616 . The horizontal axis 608 represents time. It should be noted that this is but one example sequencing of refresh signals and in other embodiments other sequencing or ordering for refresh signals may be arrived at by one of ordinary skill in the art.
[0071] In this example embodiment a refresh signal 620 is sent during a first refresh period on channel A from PHY A 612 . After a time period or counter value delay 624 , a refresh signal 630 is sent on channel C from PHY B 616 . It is contemplated that the time or counter value at which each transmitter transmits it refresh is set based on the LDPC frame counter, which start at the transition to PAM 16 .
[0072] Thereafter, a refresh signal 634 is sent from transmitter B associated with PHY A 612 . Other refresh signals are sent as shown with the predetermined timing and spacing as shown in FIG. 6 . During periods when a refresh signal is not being sent, the transmitter is in sleep mode and not transmitting signals as shown. A receiver corresponding to the transmitter is also in sleep mode and only wakes at predetermined and known times to receive and process the refresh signal.
[0073] The spacing between refresh signals shown in FIG. 6 may be selected based on the particular clock synchronization requirements. In one embodiment the refresh counter is set to a 512 LDPC frame count. In the network Ethernet embodiment having 8 transmitters total between a master and slave transceiver set, equate to a refresh period every 64 LDPC frames. In one embodiment the refresh comprises 4 LDPC frames in duration and the subsequent quiet or sleep period is 124 LDPC frames. This equate to a total of 128 frames per total cycle. In other embodiments other refresh signal spacing may be selected. In one embodiment, the timing of each refresh is set by the LDPC frame counter which is triggered by the transition to PAM 16 .
[0074] Spacing between refreshes provides numerous advantages. One such advantage is that a clock update from one periodic refresh signal may be utilized to update the clock for all channels at a PHY. A timing recovery loop defines when or how often a system needs to update or refresh its clock synchronization. In this embodiment every refresh signal sent out and received is shared between pairs to refresh the clock synchronization for all channels A-D on a PHY 612 , 616 . However, the adaptive filters and equalizers do not require updating as often as the clock and can thus be updated with each refresh signal, such as once every 512 LDPC frames, which is the cycle period in this embodiment for the refresh signal. Other embodiments may adapt at a different cycle timing.
[0075] Another advantage with the timing and spacing scheme which does not overlap refresh signals is that a receiver in the same transceiver as a transmitter sending a refresh signal may remain in sleep mode because it does not have to process an incoming refresh signal. By preventing overlap of refresh signal periods, the echo canceller may remain off, which in turn increases power savings. As is understood, echo cancellers consume a significant amount of power and by keeping the echo canceller circuitry off, power savings is maximized.
[0076] Another advantage is best understood in relation to FIG. 7 , which illustrates an echo response resulting from an exemplary refresh signal. In this example plot the refresh signal is a fixed number of T r frames. In one embodiment, this fixed number of T r frames comprises 4 LDPC frames. By maintaining sufficient spacing between a refresh signal 704 and subsequent refresh signals on other channels, the echo response 708 from the refresh signal 704 does not affect other refresh periods. As shown, before another refresh signal on another channel occurs, the echo will have dissipated so that it does not interfere with the other channels refresh period.
[0077] Another advantage over the prior art is that this method substantially reduces the complexity of sleep signaling and reduces the risk that different implementations of the LPI mode do not interoperate. For example, alternative solutions require complex handshaking for the sleep signal, which increases power and design complexity and interoperability risk. Other solutions are likely to have corner conditions that are difficult to test and debug, particularly when the latency of the link, the transmit path, and the receive path vary.
[0078] Furthermore, other solutions might require a longer handshaking period that would reduce the energy efficiency of the low power idle mode. Since the timing of the master refresh signal is known precisely, the implementer can chose to power down circuits for a longer period of time than if the timing were uncertain, which results in power savings.
[0079] FIG. 8 illustrates a timing diagram between PHY A transceiver and PHY B transceiver. This diagram is provided for purposes of understanding and is not to scale and does not depict accurate timing routines for an actual system. One potential problem with the prior art is that when a PHY A transmitter 804 switches to PAM 16 coding after training, the corresponding PHY B receiver 806 likewise transitions to PAM 16 . However, there may be a period W 820 before the PHY B transmitter 812 transitions from PAM 2 coding to PAM 16 coding. This period W 820 represents a period when prior art phys are not normally synchronized and the original 10gbase-t standard did not require close synchronization (since it was not required, and interoperability is simpler if the timing requirements were less stringent).
[0080] As can be appreciated, if this value W 820 is excessively large, then it may be greater than the period between refresh signals or so large that it disrupts the LPI timing scheme by causing overlap of refresh signals. The current standard specifies a time period for transition time W that is undesirably long. Moreover, the standard may not specify an exact time, but instead just require that the transition to PAM 16 occur within a maximum time period. Regardless, the unknown and potentially large time period W may disrupt the refresh scheme outlined herein.
[0081] To resolve this potential conflict, it is proposed to reduce the value W 820 to a small value. In one embodiment the value of W is zero of a value close to zero such that the PHY B transmitter transitions to PAM 16 at the same time as PHY A transmitter 804 or PHY B receiver 808 . In one embodiment the value of W is 1 LDPC frame. In one embodiment the value of W is less than 5 LDPC frames. In one embodiment the value of W is less than 10 LDPC frames. In one embodiment the value of W is less than 20 LDPC frames. A complete refresh cycle may comprise 512 LDPC frames with each refresh signal comprising 4 LDPC frames.
[0082] In one embodiment the transition of PHY A 804 is the transition from which one or more or all other PHY systems derive their refresh timing. In one embodiment, one channel is defined as a master and this channels transition from PAM 2 to PAM 16 a master transition. From this master transition all other refresh transitions may be set.
[0083] It is also contemplated that instead or in addition to minimizing or fixing the value W at a small number of LDPC frame and linking the start of the LDPC frame counter to the transition from PAM 2 to PAM 16 , that the refresh period may be established based on when PAM 16 coding is initiated by using the infofield offsets to predict exactly when this will happen. The synchronization may be based on the transition from PAM 2 to PAM 16 , using the frame boundaries established using the infofields. Thus in one embodiment, the system training, if starting slave silent mode (with the master transmitting), will occur with only one side transmitting and the synchronization or refresh timing will be set or occur when PAM 2 synchronization occurs. Because the frame boundaries are always present, when the slave syncs to the master, the refresh timing scheme may be established. Thus, the timing may be set at this event and the LDPC and infofield frames used as a timing guide.
[0084] Other systems, methods, features and advantages of the invention will be or will become apparent to one with skill in the art upon examination of the figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the invention, and be protected by the accompanying claims. While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible that are within the scope of this invention. In addition, the various features, elements, and embodiments described herein may be claimed or combined in any combination or arrangement. | 4y
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FIELD OF THE INVENTION
The present invention relates to a braking system of an agricultural vehicle and is applicable in particular to vehicles, such as combine and forage harvesters, having ancillary equipment that may be raised and lowered relative to the ground with consequential raising and lowering of the centre of gravity of the vehicle.
BACKGROUND OF THE INVENTION
On combines and forage harvesters, as well as on other agricultural vehicles, brakes are used to turn the vehicle within a smaller turning circle than would be achievable by the use of the steering wheels. The brakes are also the preferred method of steering in difficult field conditions.
In order to achieve this, two separate braking circuits are provided which have separate brake pedals for braking the left and right sides of the vehicle. The brakes are designed to be very powerful so that steering using the brakes can be achieved with minimal effort.
Furthermore, in combine and forage harvesters the hydrostatic drive system is often used for braking. During field operation, the hydrostatic drive system serves as the primary means for stopping the vehicle while the friction brakes acting on the wheels are used primarily for steering.
Of course, the same braking systems must be capable of being used when the vehicle is being driven on roads. Under such driving conditions, the two brake pedals are physically connected to one another, so that they cannot be depressed separately, and symmetrical braking is achieved by hydraulically interconnecting the two braking systems so that the same braking pressure is applied to the slave cylinders on both sides of the vehicle.
As a result, for driving on normal roads, more braking capacity is available to the driver than is needed and in some countries there is a legal requirement for simultaneous braking using the hydrostatic drive system which increases the maximum braking force still further.
The availability of an excessively high braking force presents a particular problem in the case of harvesters that are being driven on a road in that they risk toppling forwards. This problem is aggravated by the fact that, when driven on a road, the header of a harvester, that is to say the attachment on the front of the vehicle which is operable to cut and collect the crop, has to be raised and therefore changes the position of the centre of gravity of the whole vehicle.
OBJECT OF THE INVENTION
The present invention therefore seeks to avoid the risk of an agricultural vehicle toppling forwards when driven on a road without reducing its braking capacity during field operation.
SUMMARY OF THE INVENTION
In accordance with a first aspect of the present invention, there is provided an agricultural vehicle having ancillary equipment that may be raised and lowered relative to the ground with consequential changing of the position of the centre of gravity of the vehicle and having a braking system of variable capacity to enable the maximum braking force to be reduced when the position of the centre of gravity of the vehicle is changed in order to prevent the vehicle from toppling forwards during maximum braking.
The braking capacity can be reduced in a variety of ways. A first possibility is to provide two slave cylinders on each wheel, both being activated under normal conditions and one being disabled when the braking capacity is to be reduced.
In this second aspect of the invention, there is provided an agricultural vehicle having ancillary equipment that may be raised and lowered relative to the ground with consequential changing of the position of the centre of gravity of the vehicle and having a hydraulic braking system comprising a master cylinder and a slave cylinder, wherein the braking system further includes a second slave cylinder associated with the same wheel as the first slave cylinder and a valve for isolating the second slave cylinder from the master cylinder when the position of the centre of gravity of the vehicle is changed, thereby ensuring that the braking force does not exceed a safe limit below which the vehicle does not risk toppling forwards when braking.
Another possibility for achieving a variable capacity braking system is to provide a switchable hydraulic amplification stage which operates during field use but not during road use.
In this third aspect of the invention, there is provided an agricultural vehicle having ancillary equipment that may be raised and lowered relative to the ground with consequential changing of the position of the centre of gravity of the vehicle and having a hydraulic braking system comprising a master cylinder and a slave cylinder, wherein the braking system additionally comprises a pressure amplification stage and a valve having a first position in which the master cylinder is connected to the slave cylinder by way of the pressure amplification stage and a second position in which the master cylinder is directly connected to the slave cylinder, the pressure amplification stage being bypassed in the second position of the valve to ensure that the braking force does not exceed a safe limit below which the vehicle does not risk toppling forwards when braking.
Other possibilities for a dual capacity or variable capacity braking system will be readily apparent to the person skilled in the art, but the preferred approach is to selectively limit the braking force by limiting the pressure in the hydraulic braking circuits during road use. The advantage of this approach is that it involves minimal alteration to existing braking systems and can therefore if necessary be retrofitted easily to existing vehicles.
In the fourth and most preferred aspect of the invention, there is provided an agricultural vehicle having ancillary equipment that may be raised and lowered relative to the ground with consequential changing of the position of the centre of gravity of the vehicle and having a hydraulic braking system comprising a master cylinder and a slave cylinder, wherein the braking system further includes a pressure relief valve for limiting the hydraulic pressure applied to the slave cylinder when the centre of gravity of the vehicle is raised, thereby ensuring that the braking force does not exceed a safe limit below which the vehicle does not risk toppling forwards when braking.
Preferably, the agricultural vehicle has two hydraulic braking systems with separate brake pedals each acting on a respective side of the vehicle, so as to enable the vehicle to be steered by the application of a braking force to only one side of the vehicle and the master cylinders of the two braking systems additionally comprise pressure equalisation ports that are connected to one another, each port including a non-return valve that is opened as soon as the associated brake pedal is depressed, so that equal pressures are applied to the slave cylinders on the opposites sides of the vehicle when the two brake pedals are depressed simultaneously.
The pressure relief valve is conveniently connected in this case to the hydraulic line interconnecting pressure equalisation ports of the master cylinders.
In order to activate and disable the pressure relief valve selectively, a two position valve may suitably be arranged in series with the pressure relief valve, the two position valve serving to isolate the pressure relief valve from the pressure equalisations ports in its first position but not in its second position.
The two position valve could simply be a manually operated ON/OFF valve with an interlock that obliges it to be opened before the two brake pedals can be connected to one another for driving on a road.
It is preferred, however, to provide a normally closed solenoid valve that is operated automatically in dependence upon the selected drive ratio, the speed of the vehicle, the height of the header or any other parameter indicative of road use, as opposed to field use, of the vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described further, by way of example, with reference to the accompanying drawing, in which:
FIG. 1 is a block diagram of the hydraulic circuit of a braking system of an agricultural vehicle constructed in accordance with the first and fourth aspect of the invention,
FIG. 2 is section through a valve of a braking system constructed in accordance with the second aspect of the invention,
FIG. 3 is a block diagram of part of the hydraulic circuit of a braking system constructed in accordance with the third aspect of the invention, and
FIG. 4 is a block diagram similar to that of FIG. 3 showing the braking system during field use of the vehicle when the brake pedals are depressed separately.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a braking system comprising two (left and right) master cylinders 10 , 10 ′ connected to two slave cylinders 12 , 12 ′ by way of respective hydraulic pressure lines 14 , 14 ′ to form separate left and right braking circuits. The two braking circuits are identical and only one of them needs to be described.
In each of the braking circuits, the master cylinder 10 comprises a housing 10 a containing a piston 10 b that is moved by means of an actuating rod 10 c connected to a respective brake pedal. When the piston 10 b is moved by depressing a brake pedal, fluid under pressure is supplied through a port 10 d to the slave cylinder 12 , the piston of which acts on a brake pad on a respective side of the vehicle.
Each of the master cylinders 10 , 10 ′ is further connected through a port 10 e that incorporates a non-return valve 10 f , to a common reservoir 16 at ambient pressure through a line 18 . The reservoir maintains the circuits filled with hydraulic fluid as their volume increases through wear of the brake pads.
As so far described, each hydraulic circuit is entirely conventional and operates in the same manner as the braking system of most road vehicles.
Because two separate braking circuits are provided for the left and right side of the vehicle, during field operation the left and right sides of the vehicle can be braked separately by operating only one or other of the two brake pedals and this allows the vehicle to be steered by means of its brakes.
Such braking is inappropriate, for obvious reasons, when the vehicle is to be driven on a road. Thus, during road use, the brake pedals are mechanically connected to one another so that they cannot be operated separately. One cannot rely on the mechanical coupling of the brake pedals to ensure equal braking on both sides of the vehicle and this is instead accomplished, in a known manner, by interconnecting the hydraulic circuits. To this end, each of the master cylinders 10 and 10 ′ additionally comprises a pressure equalisation port 10 g that incorporates a non-return valve 10 h . The piston 10 b has a shoulder which acts on the closure member of the non-return valve 10 h as soon as the brake pedal is depressed to connect the working chamber of the cylinder to a pressure equalisation line 20 . If only one of the brake pedals is operated during field use, only one of the non-return valves 10 h will be open and high pressure will not be able to flow from the actuated braking circuit to the other. However if both pedals are depressed, even by unequal amounts, the two circuits will be able to communicate with one another through the pressure equalisation line 20 to ensure symmetrical braking when the vehicle is in road use.
As so far described, the braking system is known in the context of brake steered agricultural vehicles. Master cylinders having an additional pressure equalisation which also incorporate a non-return valve in the pressure equalisation port that is opened as soon as the piston is moved are currently available and their internal construction need not therefore be described in greater detail herein.
The illustrated embodiment of the present invention comprises a solenoid operated two position valve 24 and a pressure relief valve 26 arranged in series with one another in a line 22 that leads from the pressure equalisation line 20 to the line 18 connected to the fluid reservoir 16 .
The solenoid valve 24 is shown in its normal position for field use wherein it maintains the pressure equalisation line 20 isolated and does not therefore interfere with pressure supplied to the slave cylinders 12 , 12 ′.
However, when a parameter is sensed that indicates that the vehicle risks toppling because it is being driven on a road with the header raised, the solenoid valve 24 is moved into its other position in which it connects the pressure equalisation line 20 to the pressure relief valve 26 .
The pressure relief valve 26 is a spool valve that is acted upon in one direction by a spring and in the opposite direction by a pilot pressure derived from its intake port. As soon as the pressure applied to the relief valve 26 exceeds a threshold, which as represented by an arrow in the drawing may be adjustable to suit the vehicle, the valve opens and connects the pressure equalisation line 20 to the ambient pressure in the reservoir 16 . In this way, the pressure delivered to the slave cylinders 12 , 12 ′ is limited to the value set by the pressure relief valve and the risk of the vehicle toppling is avoided.
The signal for operating the solenoid valve 24 may be derived from any suitable source, for example from a sensor that responds to the selected drive ratio, the speed of the vehicle or the height of the header.
It will be seen from the drawing that the additional components required to eliminate the risk of the vehicle toppling during road use are the two contained within the box drawn in dotted lines, namely the two position solenoid valve 24 and the pressure relief valve 26 . These two components can be formed as a sub-assembly that may be connected using only two hydraulic connections to an existing braking system, thus making it possible to modify existing vehicles with relative ease.
Though the embodiment of FIG. 1 is preferred because of the ease of retrofitting, the capacity of the braking system can be altered in other ways as will now be described with reference to two further embodiments of the invention, shown in FIG. 2 and in FIGS. 3 and 4 , respectively. In the case of both these further embodiments, all the components shown in FIG. 1 , other than the two valves 24 and 26 , are present. These are the components that are conventionally to be found in an agricultural vehicle that can be steered by asymmetrical braking.
In the case of the alternative embodiment, a valve body 50 as shown in FIG. 2 is provided, in addition to which a second brake calliper (not shown), which incorporates an additional slave cylinder, is provided on each wheel. Lines 60 and 62 lead to the separate slave cylinders on the left side of the vehicle and lines 60 ′ and 62 ′ lead to separate slave cylinders on the right side of the vehicle. Once again, primed reference numerals will be used to avoid unnecessary repetition of description.
The valve body 50 shown in FIG. 2 has two intake ports connected to the lines 14 , 14 ′ from the master cylinders 10 , 10 ′ and four output ports connected to the lines 60 , 62 , 60 ′ and 62 ′. A valve spool 52 is mounted in a bore in the valve body 50 and at each end the spool is acted upon by a spring 55 , 55 ′ and the pressure in a control chamber 54 , 54 ′ that communicates with one of the intake ports. When equal pressures are applied to the two control chambers 54 , 54 ′, the spool 52 adopts its illustrated position. Here the lines 14 and 14 ′ are connected to the lines 60 , and 60 ′ through passages 66 and 66 ′ in the body 50 while the two further passages 68 and 68 ′ that lead to the lines 62 and 62 ′ are closed by the valve spool 52 . Thus, when both brake pedals are depressed during road use of the vehicle, only one set of brake pads acts on each side of the vehicle.
When only the left side is braked, the pressure in the control chamber 54 will move the valve spool 52 to the right as viewed, allowing fluid to flow through the passage 68 to the line 62 leading to the slave cylinder of the second calliper and two sets of brakes will be activated on the left side of the vehicle but none on the right, causing the vehicle to be steered to the left. To allow hydraulic fluid to be drained from the second slave cylinder when the brake pedal is released and the passage 68 is again closed by the valve spool 52 , a non-return valve 64 is provided which allows fluid to flow from the line 62 to the line 14 only in the direction that reduces the braking force on the wheels.
By operation of the valve body 50 , it is ensured that maximum braking force can still be applied when braking only one wheel, by means of the first and second slave cylinders. The braking force will however be divided by two when braking both wheels simultaneously because only the first slave cylinder on the left and right wheel is used due to an equal pressure being applied to both sides of the valve spool 52 .
The embodiment of FIGS. 3 and 4 comprises a valve 30 connected to the lines 14 , 14 ′ of FIG. 1 and two pressure amplifiers 38 and 38 ′ each connected to a respective one of the slave cylinders 12 and 12 ′ in FIG. 1 .
The valve 30 is generally similar to the valve 50 in FIG. 2 and has control chambers 34 and 34 ′ connected to the lines 14 and 14 ′ from the master cylinders. As in the case of the valve spool 52 in FIG. 2 , the spool 32 of the valve 30 adopts a central position, shown in FIG. 3 , when both brake pedals are depressed during road operation and an end position, shown in FIG. 4 , when only one brake pedal is depressed during field operation.
During road operation, the master cylinder lines 14 and 14 ′ are connected to the slave cylinders 12 and 12 ′ through lines 42 and 42 ′ that bypass the pressure amplification stages 38 and 38 ′ so that the latter have no effect. On the other hand, when the spool 32 moves to its end position shown in FIG. 4 because only the left brake pedal is depressed, the passage 42 is blocked by a land of the spool 32 and instead the pressure from the master cylinder line 14 is applied through the passage 40 to the amplification stage 38 which increases the pressure applied to the slave cylinder 12 by a factor equal to the ratio of the surface areas of the opposite ends of its piston. Similarly, on depressing the right brake pedal, the master cylinder line 14 ′ is blocked by another land of the spool 32 , preventing pressure to be transmitted to the right slave cylinder 12 ′.
Accordingly, when driving on the road and depressing both brake pedals simultaneously, the spool 32 is forced to stay in the middle of the valve 30 , because of the equal pressure in the master cylinder lines 14 and 14 ′.
However, because of the pressure amplification stages 38 and 38 ′, the system is able to create a higher braking force when the left or right brake is used alone. The system is dimensioned such that the braking force is within safe braking limits when driving on the road. | 4y
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BACKGROUND OF THE INVENTION
[0001] The invention relates to an electrode for a combination of supercapacitor and battery, where the electrode has an active structure. Further aspects of the invention concern processes for producing such an electrode and also a combined supercapacitor and battery cell comprising at least one such electrode.
[0002] Electric energy can, for example, be stored by means of batteries or by means of capacitors. Batteries store the electric energy in the form of chemical reaction energy and capacitors store the electric energy in the form of charges on capacitor electrodes. A battery comprises at least one positive electrode and at least one negative electrode which are separated by means of a separator. Owing to their high energy density, use is frequently made of lithium ion batteries which also display a low self discharge. In the lithium ion battery cells used in lithium ion batteries, lithium ions migrate from one electrode to the other electrode during charging and discharging of the battery. As active materials for the electrodes, use is frequently made of intercalation materials which are able to reversibly incorporate and release lithium ions. A lithium ion conductor is used for transport of the lithium ions. In the case of lithium ion battery cells used at present, which are employed, for example, in the consumer sector (cellular telephone, MP3 player, etc.) or as energy store in electric or hybrid vehicles, the lithium ion conductor is frequently a liquid electrolyte which, for example, contains the lithium electrolyte salt lithium hexafluorophosphate (LiPF 6 ) as a solution in organic solvents.
[0003] In batteries, the specific power offtake, i.e. the discharge rate, also referred to as C rate, is limited. In addition, it is possible for the battery to be damaged when the battery is discharged at high C rates because the internal currents become too high. The same problem occurs during charging of a battery: charging of a battery can also be carried out only at a particular C rate without damaging the battery. The C rate is defined as the maximum permissible charging or discharging current divided by the capacity of the battery.
[0004] For the purposes of the present patent application, the term battery or battery cell is used as is customary in the conventional language, i.e. the term battery or battery cell encompasses both a primary battery or primary battery cell and also secondary batteries or secondary cells. The latter are also referred to as rechargeable batteries or rechargeable battery cells.
[0005] In contrast to batteries, capacitors can provide very high charging and discharging currents without being damaged. For this reason, capacitors are suitable as replacement for batteries or for supplementing batteries by means of a parallel connection of battery and capacitor when a high degree of reliability and high charging and discharging currents are required.
[0006] Capacitors comprise two electrodes which are arranged parallel to one another at a small spacing. A dielectric is generally present in-between. Various construction types of capacitors are known in the prior art, with supercapacitors having a specific capacitance which is up to 10 000 times as great as that of conventional electrolyte capacitors. However, a supercapacitor achieves only about 10% of the capacity of a battery of the same weight. In the case of supercapacitors, no dielectric is used between the two electrodes. The structure of these supercapacitors resembles that of a battery and comprises two electrodes which are mechanically separated from one another by a separator and are electrically connected to one another by means of an electrolyte. Application of a voltage to the capacitor results in formation of double layers on the electrodes, in which double layers a layer of positive charges and a layer of negative charges are formed in a mirror-like arrangement. In addition, pseudocapacitances can be formed when ions come into direct contact with the surface of the electrode and release an electron to the electrode. The total capacitance of the supercapacitor is then made up of the double layer capacitance and the pseudocapacitance.
[0007] A disadvantage of the prior art is that there is no simple component which combines both battery properties and capacitor properties.
SUMMARY OF THE INVENTION
[0008] An electrode for a combination of supercapacitor and battery is proposed. The electrode comprises an active structure which comprises an active material layer which is divided stripwise in the plane, with capacitor strips and battery strips being arranged alternately in the plane.
[0009] The active materials of a capacitor electrode and of a battery electrode, respectively, are present in the capacitor strips and battery strips of the active material layer. During production of the electrode, the respective active materials are positioned, in the form of alternating strips and spatially separated from one another, in the active material layer of the active structure.
[0010] In the case of the capacitor strip, a capacitor active material which generally comprises a mixture of graphite and further additives such as a conductive material and/or an electrolyte is used.
[0011] The battery strips contain a battery active material which generally comprises a mixture of graphite and, depending on the configuration of the battery strip as cathode or anode of the battery, an anode active material or a cathode active material. Furthermore, further additives, for example a conductive material or an electrolyte, can be added to the battery active material.
[0012] In the case of a cathode, the cathode active material can, for example, be selected from among a lithiated transition metal oxide, for example Li(NiCoMn)O 2 , LiMn 2 O 4 , Li 2 MO 3 .LiMO 2 (where M is, for example, Ni, Co, Mn, Mo, Cr, Fe, Ru or V), LiMPO 4 (where M is, for example, Fe, Ni, Co or Mn), Li(Ni 0.5 Mn 1.5 )O 4 , Li x V 2 O 5 , Li x V 3 O 8 (where 0≦x≦2), and further cathode materials known to those skilled in the art, e.g. borates, phosphates, fluorophosphates, silicates. A further possibility for the active material is, for example, a lithiated sulfur.
[0013] In the case of an anode, the anode active material is, for example, selected from among a graphite, silicon and metallic lithium and films coated with lithium.
[0014] Binders can optionally also be added to the capacitor active material or the battery active material in order to increase the stability. The binders are frequently plastics or polymers. For example, PVdF (polyvinylidene fluoride) is suitable as binder.
[0015] The conductive material used in the capacitor strips and/or battery strips can, for example, be selected from among carbon nanotubes, a conductive carbon black, graphene, graphite, metal particles, treated carbon particles, carbon nanotubes, carbon filaments, metal nanotubes, metal filaments and a combination of at least two of these materials.
[0016] For liquid electrolytes in capacitors, use is made of aqueous electrolytes up to cell voltages of about 2.3 V or organic solvents, with in each case acids, bases or salts additionally being dissolved in the electrolyte in order to increase the electrical conductivity. The organic electrolytes typically used for batteries because of the relatively high cell voltage and the high dielectric strength therefore required can also be used for capacitors. The electrolyte for batteries can be, for example, a solid electrolyte based on polyethylene oxide (PEO) or based on soya. In the case of a liquid electrolyte, the lithium electrolyte salt lithium hexafluorophosphate (LiPF 6 ), for example, can be used as a solution in an organic solvent. Furthermore, it is possible to dissolve not only lithium salts for the capacitor function but additionally also acids, bases or salts in the solvent in order to increase the electrical conductivity. Solutions of quaternary ammonium salts or alkylammonium salts such as tetraethylammonium tetrafluoroborate (N(Et) 4 BF 4 ) or triethyl(methyl)ammonium tetrafluoroborate (NMe(Et) 3 BF 4 ), for example, are customary for organic electrolytes in capacitor technology.
[0017] The graphite present in the capacitor active material or in the battery active material is, for example, a pressed expanded graphite. Graphite can be converted into expandable graphite by means of an acid treatment, for example with chromic acid or sulfuric acid. The expandable graphite can be mixed with the further materials present in the capacitor strip or in the battery strip and subsequently be heat treated at a temperature of from about 850 to 900° C., forming expanded graphite. When expanded graphite is pressed in a pressing apparatus, a stable self-supporting sheet can be produced.
[0018] In advantageous embodiments of the invention, further strips having a further function can be introduced between a battery strip and a capacitor strip in the active material layer.
[0019] Examples of such further strips encompass conductivity strips which have a high proportion of graphite and optionally additional conductive materials. A further embodiment is formed by barrier strips which, for example, contain a polymer material and serve as frames or diffusion barriers. It is likewise conceivable to provide a barrier strip with additives which can suppress undesirable secondary reactions between constituents of the active material layer. Diffusion barriers can, in particular, be used in order to counter mixing of constituents of a battery strip and of a capacitor strip. A further embodiment is formed by insulation strips which have no electrical conductivity or only a low electrical conductivity and thus form an insulator between two strips, in particular between a battery strip and a capacitor strip.
[0020] In one embodiment of the electrode, the active structure comprises three layers, with a first graphite layer, the active material layer and a second graphite layer being arranged in this order.
[0021] In this variant, the active material layer is surrounded by graphite. Here, the graphite layers preferably comprise expandable graphite which has been expanded and pressed to form a stable layer. A binder is optionally added to the graphite in order to increase the stability and the elasticity. A high elasticity is particularly advantageous in connection with battery strips in the case of which a volume change occurs during charging or during discharging. If a high elasticity is required, a silicone, for example, can be used as binder.
[0022] In this embodiment, the proportion of binder in the active material layer, i.e. in the capacitor active material and the battery active material, can advantageously be reduced or the active material layer can be made completely free of a binder such as PVdF.
[0023] The first graphite layer and/or the second graphite layer preferably comprises an additive in the form of a conductive material. This gives the first and/or second graphite layer good electrical conductivity, so that these can form a contact to the active material layer like a power outlet lead.
[0024] In a further embodiment of the invention, the active material layer has a gradient perpendicular to the plane in which the active material layer has the strip structure, with the proportion of graphite and/or of a binder being lowest in the middle of the active material layer and increasing in the direction of the two surfaces.
[0025] In this variant, a structure which resembles the three-layer system comprising the first graphite layer, the active material layer and the second graphite layer is formed, but the transitions are fluid. The gradient in the direction perpendicular to the plane in which the active material layer is divided into strips leads to the concentration of graphite and/or of a binder being greatest at the surfaces of the active material layer. As in the previous embodiment, a result is that the capacitor active material is advantageously essentially enclosed by graphite even though there is no sharp boundary between a graphite layer and the active material layer. In a development of this variant, it is likewise possible to add a conductive material in order to improve the electrical conductivity, with a gradient also being able to be set for the conductive material so that the proportion of conductive material is lowest in the middle of the active material layer and increases in the direction of the two surfaces.
[0026] In a further embodiment of the invention, the active material layer has a gradient perpendicular to the plane of the active material layer, with the proportion of graphite being highest in the middle of the active material layer and decreasing in the direction of the two surfaces. In this variant, the active material layer of the electrode has a layer which consists essentially of graphite in its interior. Since graphite is a relatively good electrical conductor, a power outlet lead can be provided in this way in the interior of the active material layer over the cross section. A conductive material can optionally be added as additive to the graphite in order to effect a further improvement in the electrical conductivity. In this embodiment, the active material layer can advantageously be made very thick since the outward conduction of power is not only possible via the surfaces of the active material layer but is also assisted by the graphite layer in the interior.
[0027] In addition, it is possible for the proposed electrodes to comprise a power outlet foil on which the active structure is arranged.
[0028] Such a power outlet foil is generally a thin metal foil or a polymer film coated with a metal. If the battery strips of the electrode are configured as cathode for a lithium ion battery cell, an aluminum foil having a thickness in the range from 13 μm to 15 μm, for example, is used. In the case of production of an electrode having battery strips configured as anode, a copper foil having a thickness in the range from 6 μm to 12 μm, for example, is used. In further embodiments, it is also conceivable to use a graphite foil as power outlet foil.
[0029] A further aspect of the invention is to provide a process for producing one of the electrodes described. Here, features described for the electrode apply analogously to the process and, conversely, features described for the process apply analogously to the electrode.
[0030] In the proposed process for producing an electrode for a combination of supercapacitor and battery, starting materials for the active structure are introduced together into a pressing apparatus and pressed without addition of solvents to form a sheet, with the starting materials being introduced spatially distributed into the pressing apparatus by means of a plurality of application systems.
[0031] The pressing apparatus can be, for example, a calender. The starting materials for the capacitor strips, the battery strips and optionally for the graphite layers are supplied separately to the application systems. The application systems for producing the active material layer are configured, for example, with a plurality of nozzles which are arranged next to one another and alternately discharge the starting material for a capacitor strip and for a battery strip. The starting materials are introduced dry and do not contain any solvent. As a result, there is only little mixing of the starting materials for the capacitor strips and battery strips between the individual strips of the active material layer, so that the spatial distribution of the starting materials is essentially maintained during passage through the pressing apparatus.
[0032] The starting materials preferably comprise expanded graphite, with the expanded graphite together with the further components present in the starting materials forming a stable sheet during passage through the pressing apparatus.
[0033] In a further process for producing an electrode for a combination of supercapacitor and battery, the starting materials are firstly applied to a support or to a power outlet foil without addition of solvents by means of a plurality of application systems in one or more steps and subsequently pressed in a pressing apparatus to form a sheet.
[0034] In this embodiment, the support or the power outlet foil serve as substrate onto which the individual layers of the active structure are applied in succession. After each application of a layer, precompacting can firstly be carried out, for example by means of a roller or a doctor blade. In variants in which a support is used, the support is removed from the active structure either before passage through the pressing apparatus or after passage through the pressing apparatus. In this case, the active structure alone forms the electrode. If a power outlet foil is used, this remains joined to the active structure after passage through the pressing apparatus, so that the active structure together with the power outlet foil forms the electrode.
[0035] A calender or a static press, for example, is suitable as pressing apparatus.
[0036] A further aspect of the invention is to provide a combined supercapacitor and battery cell which comprises at least one of the electrodes described. Here, an electrode having battery strips configured as anode, a separator and an electrode having battery strips configured as cathode together with a housing form the combined supercapacitor and battery cell. The housing additionally comprises terminals via which the two electrodes are electrically contactable from the outside.
Advantages of the Invention
[0037] The proposed electrode makes it possible to combine a battery and a supercapacitor with one another directly in one component in a simple manner, with these being electrically connected in parallel. The proposed division of the electrode into strips, with capacitor strips and battery strips alternating in the plane of the active material layer, allows spatial separation of functions and thus separate optimization of the battery function and the capacitor function despite integration of the two functions in the same component.
[0038] The combined supercapacitor and battery cell which is likewise proposed can be subjected to high currents in the short term, as a result of which faster charging and discharging operations become possible. Here, the capacitor part can also be considered to be a safety buffer for the battery. The battery part is protected against high charging and discharging currents, so that it cannot be damaged even at high loads.
[0039] The integration of the graphite layer in the interior of the active material layer, as proposed in advantageous variants, advantageously improves the electrical conductivity of the active structure, so that the capacitor strips and battery strips can be made thick without there being problems with the electrical conductivity.
[0040] In the variants in which the active structure comprises three layers, with the active material layer being arranged between two graphite layers, the active structure is particularly mechanically stable. This makes it possible to reduce the proportion of binder in the active material layer, as a result of which the electrical conductivity in the active material layer is improved.
[0041] Furthermore, it is possible to configure the active structure in such a way that a stable sheet is formed after pressing, without it being necessary to provide an additional power outlet foil, for example a metal foil.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] FIG. 1 shows a self-supporting active structure having an active material layer,
[0043] FIG. 2 shows a self-supporting active structure having an active material layer enclosed between two graphite layers,
[0044] FIG. 3 shows a self-supporting active structure having an increased proportion of graphite in the middle,
[0045] FIG. 4 shows an active structure with power outlet lead,
[0046] FIG. 5 shows a three-layer active structure with power outlet lead,
[0047] FIG. 6 shows an active structure on a power outlet lead having a conductive layer arranged in the middle of the active structure and
[0048] FIG. 7 shows a sectional view of a combined supercapacitor and battery cell.
DETAILED DESCRIPTION
[0049] In the following description of working examples of the invention, identical or similar components or elements are denoted by the same reference numerals, with a repeated description of the components or elements in individual cases being omitted. The figures show the subject matter of the invention merely schematically.
[0050] FIG. 1 shows a first embodiment of an electrode 10 for a combination of supercapacitor and battery. The electrode 10 comprises an active structure 12 which, in the embodiment of FIG. 1 , comprises only a single layer, namely the active material layer 18 . FIG. 1 shows the electrode 10 in a sectional view from the side. It can be seen here that battery strips 14 and capacitor strips 16 are arranged alternately in the active material layer 18 of the active structure 12 .
[0051] FIG. 2 shows a second embodiment of the electrode 10 , likewise in a sectional view from the side. The electrode 10 again comprises an active structure 12 which, in the embodiment of FIG. 2 , comprises three layers. Here, the active structure 12 comprises a first graphite layer 24 , the active material layer 18 and a second graphite layer 26 in this order. The active material layer 18 is thus covered on its upper side and on its underside in each case with a graphite layer 24 , 26 . As described above in respect of FIG. 1 , the active material layer 18 has a strip structure, so that in the view from the side in FIG. 2 battery strips 14 and capacitor strips 16 alternate.
[0052] In a further variant which is not shown, it is conceivable for there to be no sharp transition but instead a continuous transition at the transitions between the active material layer 18 and the first graphite layer 24 and/or the second graphite layer 26 . In this way, the active structure 12 can be configured so that a gradient is formed perpendicular to the plane of the active material layer 18 . Here, the proportion of graphite is greatest at the surfaces of the active structure 12 and lowest in the middle of the active structure 12 .
[0053] FIG. 3 depicts a third embodiment of the electrode 10 . FIG. 3 once again shows the electrode 10 in a sectional view from the side. The active structure 12 comprises the active material layer 18 in which battery strips 14 and capacitor strips 16 are once again arranged alternately. The active material layer 18 has a gradient in respect of its proportion of graphite in a direction perpendicular to the plane of the active material layer 18 . The direction perpendicular to the plane is indicated by an arrow with the reference numeral 28 in FIG. 3 .
[0054] Owing to the gradient, the distribution of graphite in the battery active material and in the capacitor active material, respectively, in the capacitor strips 16 and in the battery strips 14 is selected so that it is, viewed in the direction 28 , highest in the middle of the active material layer 18 and decreases in the direction of an upper side 30 and an underside 32 . The upper side 30 and the underside 32 form the surfaces of the electrode 10 . As a result of the increased concentration of graphite in the middle of the active material layer 18 , a conductive layer 20 located in the interior of the active structure 12 is formed after pressing of the active structure 12 . The conductive layer 20 typically has an increased electrical conductivity.
[0055] In the embodiments depicted in FIG. 2 and FIG. 3 , the conductivity of the first graphite layer 24 , of the second graphite layer 26 and of the conductive layer 20 can be improved by adding an additional conductive material as additive to the graphite.
[0056] FIGS. 4, 5 and 6 show further embodiments of the electrode 10 . Here, the embodiment of FIG. 4 corresponds essentially to the electrode 10 described above for FIG. 1 , with the electrode 10 of FIG. 4 comprising a power outlet foil 22 in addition to the active structure 12 . The power outlet foil 22 is joined to one side of the active structure 12 . The power outlet foil 22 is firstly used for electrical contacting of the active structure 12 , and secondly the power outlet foil 22 can mechanically support the active structure 12 . This is useful particularly when the active structure 12 has only a small proportion of binders and/or graphite.
[0057] Except for the additional power outlet foil 22 , the electrode 10 depicted in FIG. 5 corresponds to the electrode 10 described above in relation to FIG. 2 . The power outlet foil 22 is again joined to one of the surfaces of the active structure 12 .
[0058] The electrode 10 shown in FIG. 6 corresponds to the electrode 10 described above in relation to FIG. 3 , with a power outlet foil 22 also being provided in addition to the active structure 12 , so as to form, together with the active structure 12 , the electrode 10 .
[0059] FIG. 7 shows a combined supercapacitor and battery cell in a sectional view.
[0060] FIG. 7 schematically shows a combined supercapacitor and battery cell 100 in a sectional view, with depiction of a cell housing having been omitted in the interests of simplicity. The combined supercapacitor and battery cell 100 comprises a layer sequence having an anode 101 , a separator 104 and a cathode 102 in this order.
[0061] The structure of the anode 101 and of the cathode 102 correspond essentially to the structure of an electrode as described above in relation to FIG. 4 . Here, the anode 101 comprises a first power outlet foil 221 together with an anode active structure 121 having anode battery strips 141 and anode capacitor strips 161 . Correspondingly, the cathode 102 comprises a second power outlet foil 222 together with a cathode active structure 122 having cathode battery strips 142 and capacitor strips 162 .
[0062] The separator 104 is arranged between anode 101 and cathode 102 in order to separate the anode 101 electrically and mechanically from the cathode 102 but allow flow of ions between anode 101 and cathode 102 . To effect electrical contacting of the combined supercapacitor and battery cell 100 , terminals assigned to the cell housing are in each case electrically connected to the first power outlet foil 221 and the second power outlet foil 222 .
[0063] The invention is not restricted to the working examples described here and the aspects emphasized therein. Rather, many modifications which are of the kind that a person skilled in the art would routinely make are possible within the scope defined by the claims. | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to systems for converting the energy of sea waves into useful energy.
Most of the state-of-the-art systems proposed and developed for the objective in question were designed for the exploitation of the kinetic energy of sea surf waves; all of these have failed due to technical and other reasons.
It is the object of the present invention to provide an off-shore, submerged energy generator utilizing the differential hydrostatic pressure prevailing between peaks and valleys of sea waves.
It is a further object of the invention that the generator be self-contained, i.e. working in closed cycles, without any external intervention, servicing, controls, etc.
SUMMARY OF THE INVENTION
Thus provided according to the present invention there is a system for the conversion of hydrostatic pressure variations such as generated by off-shore sea waves, into useful energy, comprising a casing hermetically sealed and submerged in the sea underneath the waves level, at least one wall of the casing being adapted to become displaced inwards and outwards of the casing under variable hydrostatic pressure applied thereon, a cylinder-and-piston system, (“the first system”) the piston being coupled to the said one wall to move in unison therewith, valve means associated with the first system so that on every stroke of the piston a quantity of a fluid supplied to the cylinder is compressed out of the cylinder into a pressurized fluid vessel and means for converting the energy of the pressurized fluid stored in the pressurized fluid vessel into useful energy.
Preferably the system further comprises a second cylinder-and-piston system (“the second system”), the piston thereof being coupled to the piston of the first system to move in unison therewith and means for controllably varying the effective volume of the cylinder of the second system.
The effective volume varying means may comprise a source of a liquid and means for introducing/evacuating the liquid into/from the said cylinder.
Further means may be provided for increasing the initial pressure in the said effective volume space.
BRIEF DESCRIPTION OF THE DRAWINGS
These and additional objects, advantages and constructional features of the invention will become more clearly understood in the light of the ensuing description of a preferred embodiment thereof, given by way of example only, with reference to the accompanying drawings, wherein:
FIG. 1 is a schematic view illustrating the underwater working location of the system and some of its sub-systems; and
FIG. 2 is a schematic representation of the system.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Shown in FIG. 1 is a portion of a sea body of water, between bottom A and surface B, waves C, forming peaks C 1 and valleys C 2 . It is the deferential hydrostatic pressure prevailing near the bottom A (or anywhere else below the surface B), namely the head balance (H 1 -H 2 ) that is harnessed to produce useful energy according to the principles to be explained below.
The energy generator generally denoted 10 , is comprised of a barrel-shaped casing 12 , with circular side wall 12 a, bottom 12 b and cover 14 .
The generator 10 is self-contained in the sense that it works in a closed loop and need not to cooperate with any other system; the functions of certain sub-systems are automatically controlled by feedback from relating other sub-systems, as will be seen later on. This stand-alone feature of the generator is regarded as one of the uniques of the present invention.
Furthermore, the generator 10 need not to rest on the sea bottom A, but can be held in buoyancy thereabove using suitable anchoring means (not shown).
As further schematically seen in FIG. 1 the cover 14 of the casing 12 is made as a membrane 16 , namely a rigid plate connected to the side wall 12 a of the casing 12 intermediate a yeildable sheet 16 a, thus allowing the displacement of the plate 16 a up and down following changes in the differential pressures applied thereto (between the interior and the outer pressures as will be explained in detail below).
The general sub-systems of the generator 10 will be now identified for better understanding of the more detailed description given in conjunction with FIG. 2; these include:
First cylinder-and-piston assembly or system 18 ;
Second cylinder-and-piston system 20 ;
Pressurized fluid (air) accumulating vessel 22 ;
Turbine 24 drivingly coupled to electrical power generator 26 ;
Liquid supply source 28 for varying the volume of the cylinder of system 20 ; and
Interim fluid (air) supply vessel 30 , for supplying the cylinder of system 18 , and connected via conduit 32 to turbine 24 discharge port, thus closing the working loop of the fluid.
Referring now for more details to FIG. 2, it should be first noted that in order to function properly, the pressure prevailing within the casing 12 of the generator 10 , denoted Pg, must always be kept less than the minimum hydrostatic pressure applied by the waves B. namely under the water head H 2 ; otherwise, the membrane cover 16 will not respond to the differential pressure (H 1 -H 2 ), i.e. become displaced up and down as desired.
Therefore, outer pressure gauge 40 and inner pressure gauge 42 are provided for constantly measuring these pressures, and to govern the operation of an electrically operated, reversible suction pump 44 for lowering the internal pressure; relief valve 46 is associated with the high pressure vessel 22 for increasing the internal pressure, as the case may be.
A central computerized unit CPU is included, which controls the various operational parameters of the generator sub-systems as will be explained below.
The first cylinder-and-piston system 18 comprises cylinder 50 and piston 52 with piston rod 54 , which extends upwards where it is rigidly connected to the plate 16 , as well as downwards out of the cylinder 50 , where it becomes the rod of piston 56 of the second cylinder-and-piston system 20 , provided with cylinder 58 . Thus defined are upper and lower effective spaces denoted S 1 and S 2 .
The system 18 acts as a double-stroke air pump, compressing air supplied from vessel 30 to vessel 22 . There are provided two unidirectional inlets 60 , 62 connected to the vessel 30 on the one hand, and two unidirectional outlets 64 , 66 , leading to the vessel 22 , as shown. Reciprocation of the piston 52 in either direction will therefore pressurize air into the vessel 22 .
Referring to the second cylinder-and-piston system 20 , it will be noted that the stroke of the piston 52 is opposed by that of the piston 56 , both being mounted to a common rod 54 .
The cylinder 58 is of a variable effective volume (space S 3 ), achieved by filling it partly, to a controlled amount, with liquid 70 , such as oil, through pump 72 from container 28 .
The variable space S 3 within the cylinder 58 underneath the piston 56 is also adapted to be charged with pre-determined, variable pressure to be supplied from pressurized air vessel 22 via control valve 80 and pressure regulator 82 .
The turbine (or air motor) 24 is operated by the pressurized air stored in vessel 22 , via control valve 84 and pressure regulator 86 .
As already explained, the discharge port of the turbine 24 is connected by conduit 32 and control valve 88 to the interim air supply vessel 30 .
Finally, a rechargeable battery 90 recharged by the generator 26 (through voltage regulator 92 ) is included for supplying electric power to operate the CPU, the suction pump 44 , the oil pump 72 and all the control valves and other devices as apparent from the foregoing description.
The operation of the generator 10 proceeds as follows. As already mentioned, the internal pressures Pg is pre-set and maintained to a value less to a certain extent, than the value of the external hydrostatic pressure to which the membrane cover 16 is subjected. Otherwise, should the internal pressure exceed the external pressure, the membrane cover would not respond to, i.e. become displaced downwards under the external pressure represented by the water head H 1 ; and if the internal pressure is too low, again the membrane 16 will not function, but remain stationary at its lowermost position, irrespective of a reduced water head H 2 .
Regulation of the pressures is maintained by the suction pump 44 , or the relief valve 46 (controlled by pressure gauges 40 , 42 ), in accordance with the actual working conditions, taking into account, among other parameters, the height of the sea waves B at any given time.
Supposing that the internal pressure has been properly adjusted, the piston 52 is at its uppermost position, and the generator is first subjected to the increased hydrostatic pressure proportional to a wave peak C 1 , then, under such elevated pressure the membrane cover 10 will descend. The piston will move down and a quantity of air (space S 2 ) will be compressed into the vessel 22 .
Simultaneously, a pressure will be built-up in the space S 3 . This counter-pressure is essential in order to achieve the upwards stroke of the piston 52 along with the lifting of the membrane cover 16 , after the wave peak C 1 has passed away and a lower hydrostatic pressure, related to head H 2 , prevails.
The appropriate adjustment of the counter pressure, which is of major importance for starting and maintaining the cyclic operation of the unit, is achieved by adjusting at least one of the following variants: Changing the effective volume S 3 , and/or charging extra pressure thereinto. The first variant is accomplished in the present example by the filling/evacuating the oil 70 into/out of the lower part of the cylinder 58 ; and the second variant is adjusted by partly directing compressed air from the vessel 22 , though pressure regulated valve 82 into the space S 3 .
The combination of the two variants, each being individually controllable by the CPU, along with suitable calculation of the area of the piston 56 relative to that of the piston 52 ensure the availability of a wide range of changeable factors required for achieving the desired result, namely, effectively, lifting the piston 56 when a relative relief of force is sensed by the membrane 16 , caused by the decreased hydrostatic pressure H 2 , with minimum loss of energy.
As the compression cycles continue, the pressure will be built-up within the vessel 22 . Upon reaching a level sufficiently high, pressure regulator 86 , by a command of the CPU, will open and the compressed air will drive the turbine 24 for as long as the pressure remains effective for that purpose. Again controlled by the CPU, the valve 84 will close and a new cycle will be started.
Low pressure air is directed through conduit 32 from the outlet port of the turbine 24 to the vessel 30 , and therefrom to the cylinder 50 . The air is therefore recycled in a closed working loop (except for a portion either expelled from the relief valve 46 , or sucked by suction pump 44 —as already mentioned above).
It goes without saying that a plurality of generators as herein described, are readily adapted to work in parallel, thus compensating for the inherent operating pauses of each one of them.
Once installed, no maintenance or servicing is requested for a long period (say, for replacing the batteries 90 ). It is thus suitable for use along coasts of deserted areas, where the supply of conventionally produced electricity is too expensive.
Those skilled in the art will readily understand that various changes, modifications and variations may be applied to the invention as above exemplified without departing from the scope of the invention as defined in and by the appended claims. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 10/053,765 filed Jan. 18, 2002, which claims priority to U.S. Provisional Patent Application Ser. No. 60/262,764, filed Jan. 19, 2001. The complete disclosures of the above applications are hereby incorporated by reference for all purposes.
[0002] Additionally, this application is a continuation-in-part of U.S. patent application Ser. No. 13/710,299 filed Dec. 10, 2012, which is a continuation of U.S. patent application Ser. No. 12/903,048 filed Oct. 12, 2010, issued as U.S. Pat. No. 8,332,521, which is a continuation of U.S. patent application Ser. No. 10/016,223 filed Nov. 1, 2001, issued as U.S. Pat. No. 7,941,541, and which claims benefit of U.S. Provisional Patent Application Ser. No. 60/245,101 filed Nov. 1, 2000. The complete disclosures of the above patent applications are hereby incorporated by reference for all purposes.
TECHNICAL FIELD OF THE INVENTION
[0003] Present invention relates to providing content to an output device and, in particular, to providing universal output in which an information apparatus can pervasively output content to an output device without the need to install a dedicated device dependent driver or applications for each output device.
BACKGROUND OF THE DISCLOSURE
[0004] The present invention relates to universal data output and, in particular, to providing a new data output method and a new raster image process for information apparatuses and output devices.
[0005] As described herein, information apparatuses refer generally to computing devices, which include both stationary computers and mobile computing devices (pervasive devices). Examples of such information apparatuses include, without limitation, desktop computers, laptop computers, networked computers, palmtop computers (hand-held computers), personal digital assistants (PDAs), Internet enabled mobile phones, smart phones, pagers, digital capturing devices (e.g., digital cameras and video cameras), Internet appliances, e-books, information pads, and digital or web pads. Output devices may include, without limitation, fax machines, printers, copiers, image and/or video display devices (e.g., televisions, monitors and projectors), and audio output devices.
[0006] For simplicity and convenience, hereafter, the following descriptions may refer to an output device as a printer and an output process as printing. However, it should be understood that the term printer and printing used in the discussion of present invention refer to one embodiment used as a specific example to simplify the description of the invention. The references to printer and printing used here are intended to be applied or extended to the larger scope and definition of output devices and should not be construed as restricting the scope and practice of present invention.
[0007] Fueled by an ever-increasing bandwidth, processing power, wireless mobile devices, and wireless software applications, millions of users are or will be creating, downloading, and transmitting content and information using their pervasive or mobile computing devices. As a result, there is a need to allow users to conveniently output content and information from their pervasive computing devices to any output device. As an example, people need to directly and conveniently output from their pervasive information apparatus, without depending on synchronizing with a stationary computer (e.g., desktop personal computer) for printing.
[0008] To illustrate, a mobile worker at an airport receiving e-mail in his hand-held computer may want to walk up to a nearby printer or fax machine to have his e-mail printed. In addition, the mobile worker may also want to print a copy of his to-do list, appointment book, business card, and his flight schedule from his mobile device. As another example, a user visiting an e-commerce site using his mobile device may want to print out transaction confirmation. In still another example, a user who takes a picture with a digital camera may want to easily print it out to a nearby printer. In any of the above cases, the mobile user may want to simply walk up to a printer and conveniently print a file (word processing document, PDF, HTML etc) that is stored on the mobile device or downloaded from a network (e.g., Internet, corporate network).
[0009] Conventionally, an output device (e.g., a printer) is connected to an information apparatus via a wired connection such as a cable line. A wireless connection is also possible by using, for example, radio communication or infrared communication. Regardless of wired or wireless connection, a user must first install in the information apparatus an output device driver (e.g., printer driver in the case the output device is a printer) corresponding to a particular output device model and make. Using a device-dependent or specific driver, the information apparatus may process output content or digital document into a specific output device's input requirements (e.g., printer input requirements). The output device's input requirements correspond to the type of input that the output device (e.g., a printer) understands. For example, a printer's input requirement may include printer specific input format (e.g., one or more of an image, graphics or text format or language). Therefore, an output data (or print data in the case the output device is a printer) herein refers to data that is acceptable for input to an associated output device. Examples of input requirements may include, without limitation, audio format, video format, file format, data format, encoding, language (e.g., page description language, markup language etc), instructions, protocols or data that can be understood or used by a particular output device make and model.
[0010] Input requirements may be based on proprietary or published standards or a combination of the two. An output device's input requirements are, therefore, in general, device dependent. Different output device models may have their own input requirements specified, designed or adopted by the output device manufacturer (e.g., the printer manufacturer) according to a specification for optimal operation. Consequently, different output devices usually require use of specific output device drivers (e.g., printer drivers) for accurate output (e.g., printing). Sometimes, instead of using a device driver (e.g., printer driver), the device driving feature may be included as part of an application software.
[0011] Installation of a device driver (e.g., printer driver) or application may be accomplished by, for example, manual installation using a CD or floppy disk supplied by the printer manufacturer. Or alternatively, a user may be able to download a particular driver or application from a network. For a home or office user, this installation process may take anywhere from several minutes to several hours depending on the type of driver and user's sophistication level with computing devices and networks. Even with plug-and-play driver installation, the user is still required to execute a multi-step process for each printer or output device.
[0012] This installation and configuration process adds a degree of complexity and work to end-users who may otherwise spend their time doing other productive or enjoyable work. Moreover, many unsophisticated users may be discouraged from adding new peripherals (e.g., printers, scanners, etc.) to their home computers or networks to avoid the inconvenience of installation and configuration. It is therefore desirable that an information apparatus can output to more than one output device without the inconvenience of installing multiple dedicated device dependent drivers.
[0013] In addition, conventional output or printing methods may pose significantly higher challenges and difficulties for mobile device users than for home and office users. The requirement for pre-installation of a device-dependent driver diminishes the benefit and concept of mobile (pervasive) computing and output. For example, a mobile user may want to print or output e-mail, PowerPoint® presentation documents, web pages, or other documents at an airport, gas station, convenience store, kiosk, hotel, conference room, office, home, etc. It is highly unlikely that the user would find at any of these locations a printer of the same make and model as is at the user's base station. As a consequence, under the conventional printing method, the user would have to install and configure a printer driver each time at each such remote location before printing. It is usually not a viable option given the hundreds, or even thousands of printer models in use, and the limited storage, memory space, and processing power of the information apparatus.
[0014] Moreover, the user may not want to be bothered with looking for a driver or downloading it and installing it just to print out or display one page of email at the airport. This is certainly an undesirable and discouraging process to promote pervasive or mobile computing. Therefore, a more convenient printing method is needed in support of the pervasive computing paradigm where a user can simply walk up to an output device (e.g., printer or display device) and easily output a digital document without having to install or pre-install a particular output device driver (e.g., printer driver).
[0015] Another challenge for mobile users is that many mobile information apparatuses have limited memory space, processing capacity and power. These limitations are more apparent for small and low-cost mobile devices including, for example, PDAs, mobile phones, screen phones, pagers, e-books, Internet Pads, Internet appliances etc. Limited memory space poses difficulties in installing and running large or complex printer or device drivers, not to mention multiple drivers for a variety of printers and output devices. Slow processing speed and limited power supply create difficulties driving an output device. For example, processing or converting a digital document into output data by a small mobile information apparatus may be so slow that it is not suitable for productive output. Intensive processing may also drain or consume power or battery resources. Therefore, a method is needed so that a small mobile device, with limited processing capabilities, can still reasonably output content to various output devices.
[0016] To output or render content (e.g. digital document) to an output device, a raster image processing (RIP) operation on the content is usually required. RIP operation can be computationally intensive and may include (1) a rasterization operation, (2) a color space conversion, and (3) a halftoning operation. RIP may also include other operations such as scaling, segmentation, color matching, color correction, GCR (Grey component replacement), Black generation, image enhancement compression/decompression, encoding/decoding, encryption/decryption GCR, image enhancement among others.
[0017] Rasterization operation in RIP involves converting objects and descriptions (e.g. graphics, text etc) included in the content into an image form suitable for output. Rasterization may include additional operations such as scaling and interpolation operations for matching a specific output size and resolution. Color space conversion in RIP includes converting an input color space description into a suitable color space required for rendering at an output device (e.g. RGB to CMYK conversion). Digital halftoning is an imaging technique for rendering continuous tone images using fewer luminance and chrominance levels. Halftoning operations such as error diffusion can be computationally intensive and are included when the output device's bit depth (e.g. bits per pixel) is smaller than the input raster image bit depth.
[0018] Conventionally, RIP operations are included either in an information apparatus, or as part of an output device or output system (e.g. in a printer controller). FIG. 1A illustrates a flow diagram of a conventional data output method 102 in which RIP 110 is implemented in the information apparatus. Output devices that do not include a printer controller to perform complex RIP operations, such as a lower-cost, lower speed inkjet printer, normally employ data output method 102 . In data output method 102 , an information apparatus obtains content (e.g. a digital document) in step 100 for rendering or output at an output device. The information apparatus may includes an application (e.g. device driver), which implements RIP operation 110 . The information apparatus generates an output data in step 120 and transmits the output data to the output device in step 130 for rendering. The output data relating to the content is in an acceptable form (e.g. in an appropriate output size and resolution) to the output engine (e.g. display engine, printer engine etc.) included in the output device. The output data in a conventional output method 102 is usually device dependent.
[0019] One drawback for the data output method 102 of FIG. 1A is that the information apparatus performs most if not the entire raster image processing operations 110 required for output. The RIP operations may require intensive computation. Many information apparatus such as mobile information device might have insufficient computing power and/or memory to carry out at an acceptable speed the RIP operations 110 required in an output process.
[0020] Another drawback for the conventional data output method 102 of FIG. 1A is that the generated output data is device dependent and therefore is typically not very portable to other output devices. As a result, the information apparatus may need to install multiple applications or device drivers for multiple output devices, which may further complicate its feasibility for use in information apparatuses with limited memory, storage and processing power.
[0021] FIG. 1B illustrates a flow diagram of another conventional data output method 104 in which the RIP is implemented in an output device. An example of an output device that implements process 104 is a high-speed laser printer which includes a printer controller for performing RIP operations and an output engine (e.g. printer engine) for rendering content. Printer controller may be internally installed or externally connected to an output device (printer in this example). In data output method 104 , an information apparatus obtains content for output in step 100 and generates in step 160 an output data or print data for transmitting to the output device in step 170 . Print data includes information related to the content and is usually encoded in a page description language (PDL) such as PostScript and PCL etc. In step 180 , the printer receives the output data or print data (in a PDL). In step 190 , a printer controller included in the printer interprets the PDL, performs RIP operations, and generates a printer-engine print data that is in a form acceptable to the printer engine (e.g. a raster image in an appropriate output size, bit depth, color space and resolution). In step 150 the printer engine renders the content with the printer-engine print data.
[0022] It will be understood that a reference to print data or output data including a language, such as PDL, should be interpreted as meaning that the print data or output data is encoded using that language. Correspondingly, a reference to a data output process generating a language, such as PDL, should be interpreted as meaning that the data output process encodes data using that language.
[0023] There are many drawbacks in the conventional data output method 104 shown in FIG. 1B . These drawbacks are especially apparent for mobile computing devices with limited processing power and memory. One such drawback is that the output data or print data, which include a page description language (PDL) such as PostScript or PCL, can be very complex. Generating complex PDL may increase memory and processing requirements for an information apparatus. Furthermore, interpreting, decoding and then raster image processing complex PDL can increase computation, decrease printing speed, and increase the cost of the output device or its printer controller.
[0024] Another drawback is that the output data that includes PDL can creates a very large file size that would increase memory and storage requirements for the information apparatus, the output device and/or the printer controller etc. Large file size may also increase the bandwidth required in the communication link between the information apparatus and the output device.
[0025] Finally, to rasterize text in an output device, a printer controller may need to include multiple fonts. When a special font or international characters is not included or missing in the printer controller, the rendering or output can potentially become inaccurate or inconsistent.
SUMMARY OF THE INVENTION
[0026] Accordingly, this invention provides a convenient universal data output method in which an information apparatus and an output device or system share the raster image processing operations. Moreover, the new data output method eliminates the need to install a plurality of device-dependent dedicated drivers or applications in the information apparatus in order to output to a plurality of output devices.
[0027] In accordance with present invention, an electronic system and method of pervasive and universal output allow an information apparatus to output content conveniently to virtually any output device. The information apparatus may be equipped with a central processing unit, input/output control unit, storage unit, memory unit, and wired or wireless communication unit or adapters. The information apparatus preferably includes a client application that may be implemented as a software application, a helper application, or a device driver (a printer driver in case of a printer). The client application may include management and control capabilities with hardware and software components including, for example, one or more communication chipsets residing in its host information apparatus.
[0028] The client application in the information apparatus may be capable of communicating with, managing and synchronizing data or software components with an output device equipped with an output controller of present invention.
[0029] Rendering content in an output device refers to printing an image of the content onto an substrate in the case of a printing device; displaying an image of the content in the case of a displaying device; playing an audio representation of the content in a voice or sound output device or system.
[0030] An output controller may be a circuit board, card or software components residing in an output device. Alternatively, the output controller may be connected externally to an output device as an external component or “box.” The output controller may be implemented with one or more combinations of embedded processor, software, firmware, ASIC, DSP, FPGA, system on a chip, special chipsets, among others. In another embodiment, the functionality of the output controller may be provided by application software running on a PC, workstation or server connected externally to an output device.
[0031] In conventional data output method 102 as described with reference to FIG. 1A , an information apparatus transmits output data to an output device for rendering. Output data corresponds to content intended for output and is mostly raster image processed (RIPed) and therefore is device dependent because raster image processing is a typical device dependent operation. Output data may be encoded or compressed with one or more compression or encoding techniques. In present invention, an information apparatus generates an intermediate output data for transmitting to an output device. The intermediate output data includes a rasterized image corresponding to the content; however, device dependent image processing operations of a RIP (e.g. color matching and halftoning) have not been performed. As a result, an intermediate output data is more device independent and is more portable than the output data generated by output method with reference to FIG. 1A .
[0032] In one implementation of this invention, the intermediate output data includes MRC (Mixed raster content) format, encoding and compression techniques, which further provides improved image quality and compression ratio compared to conventional image encoding and compression techniques.
[0033] In an example of raster image process and data output method of the present invention, a client application such as a printer driver is included in an information apparatus and performs part of raster image processing operation such as rasterization on the content. The information apparatus generates an intermediate output data that includes an output image corresponding to the content and sends the intermediate output data to an output device or an output system for rendering. An output controller application or component included in the output device or output system implements the remaining part of the raster image processing operations such as digital halftoning, color correction among others.
[0034] Unlike conventional raster image processing methods, this invention provides a more balanced distribution of the raster image processing computational load between the Information apparatus and the output device or the output system. Computational intensive image processing operations such as digital halftoning and color space conversions can be implemented in the output device or output system. Consequently, this new raster image processing method reduces the processing and memory requirements for the information apparatus when compared to conventional data output methods described with reference to FIG. 1A in which the entire raster image process is implemented in the information apparatus. Additionally, in this invention, a client application or device driver included in the information apparatus, which performs part of the raster image processing operation, can have a smaller size compared to a conventional output application included in the information apparatus, which performs raster image processing operation.
[0035] In another implementation, the present invention provides an information apparatus with output capability that is more universally accepted by a plurality of output devices. The information apparatus, which includes a client application, generates an intermediate output data that may include device independent attributes. An output controller includes components to interpret and process the intermediate output data. The information apparatus can output content to different output devices or output systems that include the output controller even when those output devices are of different brand, make, model and with different output engine and input data requirements. Unlike conventional output methods, a user does not need to preinstall in the information apparatus multiple dedicated device dependent drivers or applications for each output device.
[0036] The combination of a smaller-sized client application, a reduced computational requirement in the information apparatus, and a more universal data output method acceptable for rendering at a plurality of output devices enable mobile devices with less memory space and processing capabilities to implement data output functions which otherwise would be difficulty to implement with conventional output methods.
[0037] In addition, this invention can reduce the cost of an output device or an output system compared to conventional output methods 104 that include a page description language (PDL) printer controller. In the present invention, an information apparatus generates and sends an intermediate output data to an output device or system. The intermediate output data in one preferred embodiment includes a rasterized output image corresponding to the content intended for output. An output controller included in an output device or an output system decodes and processes the intermediate output data for output, without performing complex interpretation and rasterization compared to conventional methods described in process 104 . In comparison, the conventional data output process 104 generates complex PDL and sends this PDL from an information apparatus to an output device that includes a printer controller (e.g. a PostScript controller or a PCL5 controller among others). Interpretation and raster image processing of a PDL have much higher computational requirements compared to decoding and processing the intermediate output data of this invention that include rasterized output image or images. Implementing a conventional printer controller with, for example, PDL increases component cost (e.g. memories, storages, ICs, software and processors etc.) when compared to using the output controller included in the data output method of this present invention.
[0038] Furthermore, an output data that includes PDL can create a large file size compared to an intermediate output data that includes rasterized output image. The data output method for this invention comparatively transmits a smaller output data from an information apparatus to an output device. Smaller output data size can speed up transmission, lower communication bandwidth, and reduce memory requirements. Finally, this invention can provide a convenient method to render content at an output device with or without connection to a static network. In conventional network printing, both information apparatus and output device must be connected to a static network. In this invention, through local communication and synchronization between an information apparatus and an output device, installation of hardware and software to maintain static network connectivity may not be necessary to enable the rendering of content to an output device.
[0039] According to the several aspects of the present invention there is provided the subject matter defined in the appended independent claims.
[0040] Additional objects and advantages of the present invention will be apparent from the detailed description of the preferred embodiment thereof, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0041] FIG. 1A is a flow diagram of a conventional data output method and its corresponding raster image process in accordance with prior art.
[0042] FIG. 1B is a flow diagram of a second conventional data output method and its corresponding raster image process for an output device that includes a conventional printer controller in accordance with prior art.
[0043] FIGS. 2A and 2B are block diagrams illustrating components of an operating environment that can implement the process and apparatus of the present invention.
[0044] FIG. 3A is a schematic block diagram illustrating hardware/software components of an information apparatus implementation in accordance with the present invention. The information apparatus includes an operating system.
[0045] FIG. 3B is a second schematic block diagram illustrating hardware/software components of an information apparatus implementation in accordance with the present invention.
[0046] FIG. 4A is a block diagram of a conventional printing system or printer with a conventional printer controller.
[0047] FIG. 4B is a block diagram of a second conventional output system or output device.
[0048] FIG. 5A is a schematic block diagram of a printing system or printer with a conventional printer controller and an output controller in accordance with present invention.
[0049] FIG. 5B is a schematic block diagram of a second output system or output device that includes an output controller in accordance with present invention.
[0050] FIG. 6A is a schematic block diagram illustrating hardware/software components of an output controller in accordance with present invention. The output controller includes an operating system.
[0051] FIG. 6B is a second schematic block diagram illustrating hardware/software components of an output controller in accordance with present invention. The output controller does not include an operating system.
[0052] FIG. 6C is a third schematic block diagram illustrating hardware/software components of an output controller in accordance with present invention. The output controller combines the functionality of a printer controller and an output controller of present invention.
[0053] FIGS. 7A-7F illustrate various configurations and implementations of output controller with respect to an output device such as a printer.
[0054] FIG. 8A is a block diagram illustrating an exemplary implementation of hardware/software components of wireless communication unit.
[0055] FIG. 8B is block diagram illustrating a second exemplary implementation of hardware/software components of wireless communication unit.
[0056] FIG. 9 is a flow diagram of a universal data output method and its corresponding raster imaging process of the present invention.
[0057] FIG. 10 is a block diagram of a universal data output method of the present invention with respect to the components, system and apparatus described with reference to FIG. 2 .
[0058] FIG. 11 is a flow diagram illustrating one way of implementing a discovery process optionally included in the output process of FIG. 10 .
[0059] FIGS. 12A and 12B are flow diagrams of exemplary client application process included in the output process of FIG. 10 .
[0060] FIGS. 13A and 13B are flow diagrams of exemplary output device or output system process included in the output process of FIG. 10 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0061] Sets forth below are definitions of terms that are used in describing implementations of the present invention. These definitions are provided to facilitate understanding and illustration of implementations of the present invention and should in no way be construed as limiting the scope of the invention to a particular example, class, or category.
[0062] Output Device Profile (or Object)
[0063] An output device profile (or object) includes software and data entity, which encapsulates within itself both data and attributes describing an output device and instructions for operating that data and attributes. An output device profile may reside in different hardware environments or platforms or applications, and may be transported in the form of a file, a message, a software object or component among other forms and techniques. For simplicity of discussion, a profile or object may also include, for example, the concept of software components that may have varying granularity and can consist of one class, a composite of classes, or an entire application.
[0064] The term profile or object used herein is not limited to software or data as its media. Any entity containing information, descriptions, attributes, data, instructions etc. in any computer-readable form or medium such as hardware, software, files based on or including voice, text, graphics, image, or video information, etc., are all valid forms of profile and object definition.
[0065] A profile or object may also contain in one of its fields or attributes a reference or pointer to another profile or object, or a reference or pointer to data and or content. A reference to a profile or object may include one or more, or a combination of pointers, identifiers, names, paths, addresses or any descriptions relating to a location where an object, profile, data, or content can be found.
[0066] An output device profile may contain one or more attributes that may identify and describe, for example, the capabilities and functionalities of a particular output device such as a printer. An output device profile may be stored in the memory component of an output device, an information apparatus or in a network node. A network node includes any device, server or storage location that is connected to the network. As described below in greater detail, an information apparatus requesting output service may communicate with an output device. During such local service negotiation, at least a partial output device profile may be uploaded to the information apparatus from the output device. By obtaining the output device profile (or printer profile in the case of a printer), the information apparatus may learn about the capability, compatibility, identification, and service provided by the output device.
[0067] As an example, an output device profile may contain one or more of the following fields and or attribute descriptions. Each of following fields may be optional, and furthermore, each of the following fields or attributes may or may not exist in a particular implementation (e.g., may be empty or NULL):
[0068] Identification of an output device (e.g., brand, model, registration, IP address etc.)
Services and feature sets provided by an output device (e.g., color or grayscale output, laser or inkjet, duplex, output quality, price per page, quality of service, etc.) Type of input languages, formats, output data and/or input requirements (e.g., PostScript, PCL, XML, RTL, etc.) supported by an output device. Device specific or dependent parameters and information (e.g., communication protocols, color space, color management methods and rendering intents, resolution, halftoning methods, dpi (dots-per-inch), bit depth, page size, printing speed, number of independent colors channels or ink etc.) Data and tables needed for image processing such as color table, halftone table, scale factor, encoding/decoding parameters and methods, compression and decompression parameters and method etc. Another profile which contain parameters and information about the output device and its service (e.g. color profiles, halftoning profiles, communication profiles, rasterization profiles, quality of service etc.). Payment information on a plurality of services provided by an output device. Information or security requirements and type of authentication an output device supports. Date and version of the output device profile, history of its modification and updates. Software components containing algorithms or instructions or data, which may be uploaded to run in an information apparatus. For example, a graphical user interface (GUI) software component may be uploaded to an information apparatus. The software component may be incorporated into or launched in the information apparatus by a client application of present invention to capture a user's preferences (e.g., print quality, page layout, number of copies, number of cards per page, etc.). In another example, software components may include methods, instructions or executables for compression/decompression, encoding/decoding, color matching or correction, segmentation, scaling, halftoning, encryption/decryption among others. Pointer or reference to one or more output device parameters, including one or more of the above described output device profile or object fields and or attribute descriptions. For example, a more up-to-date or original version of output device parameters may sometimes be stored in a network node (any device, server or storage location that is connected to the network), or within the information apparatus where it can be obtained by the client application. An output device profile may include pointer or pointers to these output device parameters.
[0079] Content (or Data Content, Digital Content, Output Content)
[0080] Content (or data content, digital content, output content) is the data intended for output, which may include texts, graphics, images, forms, videos, audio among other content types. Content may include the data itself or a reference to that data. Content may be in any format, language, encoding or combination, and it can be in a format, language or encoding that is partially or totally proprietary. A digital document is an example of content that may include attributes and fields that describe the digital document itself and or reference or references to the digital document or documents. Examples of a digital document may be any one or combination of file types: HTML, VHTML, PostScript, PCL, XML, PDF, MS Word, PowerPoint, JPEG, MPEG, GIF, PNG, WML, VWML, CHTML, HDML, ASCII, 2-byte international coded characters, etc. Content may be used interchangeably with the term data content, output content or digital content in the descriptions of present invention.
[0081] Intermediate Output Data
[0082] Output data (or print data in case of a printer) is the electronic data sent from an information apparatus to an output device. Output data is related to the content intended for output and may be encoded in a variety of formats and languages (e.g. postscript, PCL, XML), which may include compressed or encrypted data. Some output device manufacturers may also include in the output data (or print data) a combination of proprietary or non-proprietary languages, formats, encoding, compression, encryption etc.
[0083] Intermediate output data is the output data of the present invention, and it includes the broader definition of an output file or data generated by an information apparatus, or a client application or device driver included in the information apparatus. An intermediate output data may contain text, vector graphics, images, video, audio, symbols, forms or combination and can be encoded with one or more of a page description language, a markup language, a graphics format, an imaging format, a metafile among others. An intermediate output data may also contain instructions (e.g. output preferences) and descriptions (e.g. data layout) among others. Part or all of an intermediate output data may be compressed, encrypted or tagged.
[0084] In a preferred embodiment of this invention, intermediate output data contains rasterized image data. For example, vector graphics and text information or objects that are not in image form included in content can be rasterized or conformed into image data in an information apparatus and included in an intermediate output data. Device dependent image processing operations of a RIP such as digital halftoning and color space conversions can be implemented at an output device or an output system.
[0085] The intermediate output data can be device dependent or device independent. In one implementation, the rasterized output image is device dependent if the rasterization parameters used, such as resolution, scale factor, bit depth, output size and or color space are device dependent. In another implementation of this invention, the rasterized image may be device independent if the rasterization parameters used are device independent. Rasterization parameter can become device independent when those parameters include a set of predetermined or predefined rasterization parameters based on a standard or a specification. With predefined or device independent rasterization parameters, a client application of present invention can rasterize at least a portion of the content and generate a device independent image or images included in the intermediate output data. By doing so, the intermediate output data may become device independent and therefore, become universally acceptable with output devices that have been pre-configured to accept the intermediate output data.
[0086] One advantage of rasterizing or converting text and graphics information into image data at the information apparatus is that the output device or printer controller no longer needs to perform complex rasterization operation nor do they need to include multiple fonts. Therefore, employing the intermediate output data and the data output method described herein could potentially reduce the cost and complexity of an output controller, printer controller and or output device.
[0087] One form of image data encoding is known as mixed raster content, or MRC. Typically, an image stored in MRC includes more than one image or bitmap layers. In MRC, an image can be segmented in different layers based on segmentation criteria such as background and foreground, luminance and chrominance among others. For example, an MRC may include three layers with a background layer, a foreground layer and a toggle or selector layer. The three layers are coextensive and may include different resolution, encoding and compression. The foreground and background layers may each contain additional layers, depending on the manner in which the respective part of the image is segmented based on the segmentation criteria, component or channels of a color model, image encoding representation (HLS, RGB, CMYK, YCC, LAB etc) among others. The toggle layer may designate, for each point, whether the foreground or background layer is effective. Each layer in a MRC can have different bit depths, resolution, color space, which allow, for example, the foreground layer to be compressed differently from the background layer. The MRC form of image data has previously been used to minimize storage requirements. Further, an MRC format has been proposed for use in color image fax transmission.
[0088] In one embodiment of present invention, the intermediate output data includes one or more rasterized output images that employ MRC format, encoding and or related compression method. In this implementation, different layers in the output image can have different resolutions and may include different compression techniques. Different information such as chrominance and luminance and or foreground and background information in the original content (e.g. digital document) can be segmented and compressed with different compression or encoding techniques. Segmented elements or object information in the original content can also be stored in different image layers and with different resolution. Therefore, with MRC, there is opportunity to reduce output data file size, retain greater image information, increase compression ratio, and improve image quality when compared to other conventional image encoding and compression techniques. Implementations of rasterization, raster image processing and intermediate output data that include MRC encoding in the present invention are described in more detail below.
[0089] Rasterization
[0090] Rasterization is an operation by which graphics and text in a digital document are converted to image data. For image data included in the digital document, rasterization may include scaling and interpolation. The rasterization operation is characterized by rasterization parameters including, among others bit depth and resolution. A given rasterization operation may be characterized by several more rasterization parameters, including output size, color space, color channels etc. Values of one or more of the rasterization parameters employed in a rasterization operation may be specified by default; values of one or more of the rasterization parameters may be supplied to the information apparatus as components of a rasterization vector. In a given application, the rasterization vector may specify a value of only one rasterization parameter, default values being employed for other rasterization parameters used in the rasterization operation. In another application the rasterization vector may specify values of more than one, but less than all, rasterization parameters, default values being employed for at least one other rasterization parameter used in the rasterization operation. And in yet another application the rasterization vector may specify values of all the rasterization parameters used in the rasterization operation.
[0091] FIGS. 2A and 2B are block diagrams illustrating components of an operating environment that can implement the process and apparatus of present invention. FIG. 2A shows an electronic system which includes an information apparatus 200 and an output device 220 . The output device 220 includes an output controller 230 . FIG. 2B illustrates a second implementation of an electronic system that includes an information apparatus 200 and an output system 250 . The output system 250 includes an output device 220 and an output controller 230 which may be externally connected to, or otherwise associated with, the output device 220 in the output system 250 .
[0092] Information apparatus 200 is a computing device with processing capability. In one embodiment, information apparatus 200 may be a mobile computing device such as palmtop computer, handheld device, laptop computer, personal digital assistant (PDA), smart phone, screen phone, e-book, Internet pad, communication pad, Internet appliance, pager, digital camera, etc. It is possible that information apparatus 200 may also include a static computing device such as a desktop computer, workstation, server, etc.
[0093] FIGS. 3A and 3B are block diagrams illustrating examples of hardware/software components included in an information apparatus 200 of present invention.
[0094] Information apparatus 200 may contain components such as a processing unit 380 , a memory unit 370 , an optional storage unit 360 and an input/output control unit (e.g. communication manager 330 ). Information apparatus 200 may include an interface (not shown) for interaction with users. The interface may be implemented with software or hardware or a combination. Examples of such interfaces include, without limitation, one or more of a mouse, a keyboard, a touch-sensitive or non-touch-sensitive screen, push buttons, soft keys, a stylus, a speaker, a microphone, etc.
[0095] Information apparatus 200 typically contains one or more network communication unit 350 that interfaces with other electronic devices such as network node (not shown), output device 220 , and output system 230 . The network communication unit may be implemented with hardware (e.g., silicon chipsets, antenna), software (e.g., protocol stacks, applications) or a combination.
[0096] In one embodiment of the present invention, communication interface 240 between information apparatus 200 and output device 220 or output system 250 is a wireless communication interface such as a short-range radio interface including those implemented according to the Bluetooth or IEEE 802.11 standard. The communication interface may also be realized by other standards and/or means of wireless communication that may include radio, infrared, cellular, ultrasonic, hydrophonic among others for accessing one or more network node and/or devices. Wired line connections such as serial or parallel interface, USB interface and fire wire (IEEE 1394) interface, among others, may also be included. Connection to a local network such as an Ethernet or a token Ring network, among others, may also be implemented in the present invention for local communication between information apparatus 200 and output device 220 . Examples of hardware/software components of communication units 350 that may be used to implement wireless interface between the information apparatus 200 and the output device 220 are described in more detail with reference to FIGS. 8A and 8B below.
[0097] For simplicity, FIG. 3 illustrates one implementation where an information apparatus 200 includes one communication unit 350 . However, it should be noted that an information apparatus 200 may contain more than one communication unit 350 in order to support different interfaces, protocols, and/or communication standards with different devices and/or network nodes. For example, information apparatus 200 may communicate with one output device 220 through a Bluetooth standard interface or through an IEEE 802.11 standard interface while communicating with another output device 220 through a parallel cable interface. The information apparatus 200 may also be coupled to a wired or wireless network (e.g. the Internet or corporate network) to send, receive and/or download information.
[0098] Information apparatus 200 may be a dedicated device (e.g., email terminal, web terminal, digital camera, e-book, web pads, Internet appliances etc.) with functionalities that are pre-configured by manufacturers. Alternatively, information apparatus 200 may allow users to install additional hardware components and or application software 205 to expand its functionality.
[0099] Information apparatus 200 may contain a plurality of applications 205 to implement its feature sets and functionalities. As an example, a document browsing or editing application may be implemented to help user view and perhaps edit, partially or entirely, digital documents written in certain format or language (e.g., page description language, markup language, etc.). Digital documents may be stored locally in the information apparatus 200 or in a network node (e.g., in content server). An example of a document browsing application is an Internet browser such as Internet Explorer, Netscape Navigator, or a WAP browser. Such browsers may retrieve and display content (e.g. digital content) written in mark-up languages such as HTML, WML, XML, CHTML, HDML, among others. Other examples of software applications in the information apparatus 200 may include a document editing software such as Microsoft Word™ which also allows users to view and or edit digital documents that have various file extensions (e.g., doc, rtf, html, XML etc.) whether stored locally in the information apparatus 200 or in a network node. Still, other example of software applications 205 may include image acquisition and editing software.
[0100] As illustrated previously with reference to FIG. 1 , there are many difficulties in providing output capability to an information apparatus 200 that has limited memory and processing capability. To address theses difficulties, information apparatus 200 includes a client application 210 that helps provide the universal data output capability of the present invention. Client application 210 may include software and data that can be executed by the processing unit 380 of information apparatus 200 . Client application 210 may be implemented as a stand-alone software application or as a part of or feature of another software application, or in the form of a device driver, which may be invoked, shared and used by other application software 205 in the information apparatus 200 . Client application 210 may also include components to invoke other applications 205 (e.g., a document browsing application, editing application, data and/or image acquisition application, a communication manager, a output manager etc.) to provide certain feature sets, as described below. FIG. 3 illustrates a configuration where the client application 210 is a separate application from the other application 205 such as the case when the client application is a device driver; however, it should be noted that the client application 210 can be combined or being part of the other application not shown in FIG. 3 . Client application 210 may be variously implemented in an information apparatus 200 and may run on different operating systems or platforms. The client application 210 may also run in an environment with no operating system. For example, FIG. 3A illustrates an implementation where the information apparatus 200 A includes an operating system 340 A; while FIG. 3B illustrates an implementation where the information apparatus 200 B does not include an operating system.
[0101] Client application 210 includes a rasterization component 310 to conform content into one or more raster output images according to one or more rasterization parameters; an intermediate output data generator component 320 that generates and/or encodes intermediate output data that includes the one or more output images; and a communications manager 330 that manages the communication and interaction with an output device 220 or system 250 or output controller 230 . Communications manager can be implemented as part of the client application 210 (shown in FIG. 3 ) or as a separate application (not shown). Components in a client application can be implemented in software, hardware or combination. As an example, client application 210 may include or utilize one or more of the following:
Components or operations to obtain content (e.g. digital document) for output. The client application 210 may obtain a digital document from other applications 205 (e.g. document browsing application, content creation and editing application, etc.), or the client application 210 may provide its own capability for user to browse, edit and or select a digital document. Components or operations to rasterize content that includes text, graphics and images among others objects or elements into one or more raster images according to a set of rasterization parameters such as scale factor, output size, bit depth, color space and resolution. The rasterization parameters may be obtained in various ways, for example, from an output device profile uploaded from an output device 220 , or stored locally in information apparatus 200 , or manually inputted by a user. Alternatively, rasterization parameters may be based on a predefined standard or specification stored in the information apparatus 200 as a set of defaults, or hard-coded in the client application 210 , or calculated by the client application 210 after communicating with an output device 220 , output controller 230 , and/or a user. Components or operations to generate intermediate output data that includes at least one rasterized output image corresponding to the content (e.g. digital document). This process may further include one or combination of compression, encoding, encryption and color correction among others. The intermediate output data may include, for example, images, instructions, documents and or format descriptions, color profiles among others. Components or operations to transmit the intermediate output data to an output device 220 or system 250 through wired or wireless communication link 240 .
[0106] The client application 210 may also optionally include or utilize one or more of the following components or operations:
Components or operations to communicate with one or more output devices 220 to upload an output device profile. Components or operations to communicate directly or indirectly (such as through an operating system or component or object model, messages, file transfer etc.) with other applications 205 residing in the same information apparatus 200 to obtain objects, data, and or content needed, or related to the pervasive output process of present invention (e.g. obtain a digital document for printing). Components or operations to manage and utilize directly or indirectly functionalities provided by hardware components (e.g. communication unit 350 ) residing in its host information apparatus 200 . Components or operations to provide a graphical user interface (GUI) in host information apparatus to interact with user. Components or operations to obtain user preferences. For example, a user may directly input his or her preferences through a GUI. A set of default values may also be employed. Default values may be pre-set or may be obtained by information apparatus 200 as result of communicating and negotiating with an output device 220 or output controller 230 .
[0112] The above functionalities and process of client application 210 of present invention are described in further detail in the client application process with reference to FIG. 12 .
[0113] Output device 220 is an electronic system capable of outputting digital content regardless of whether the output medium is substrate (e.g., paper), display, projection, or sound. A typical example of output device 220 is a printer, which outputs digital documents containing text, graphics, image or any combination onto a substrate. Output device 220 may also be a display device capable of displaying still images or video, such as, without limitation, televisions, monitors, and projectors. Output device 220 can also be a device capable of outputting sound. Any device capable of playing or reading digital content in audio (e.g., music) or data (e.g., text or document) formats is also a possible output device 220 .
[0114] A printer is frequently referred to herein as an example of an output device to simplify discussion or as the primary output device 220 in a particular implementation. However, it should be recognized that present invention applies also to other output devices 220 such as fax machines, digital copiers, display screens, monitors, televisions, projectors, voice output devices, among others.
[0115] Rendering content with an output device 220 refers to outputting the content on a specific output medium (e.g., papers, display screens etc). For example, rendering content with a printer generates an image on a substrate; rendering content with a display device generates an image on a screen; and rendering content with an audio output device generates sound.
[0116] A conventional printing system in general includes a raster image processor and a printer engine. A printer engine includes memory buffer, marking engine among other components. The raster image processor converts content into an image form suitable for printing; the memory buffer holds the rasterized image ready for printing; and the marking engine transfers colorant to substrate (e.g., paper).
[0117] The raster image processor may be located within an output device (e.g. included in a printer controller 410 ) or externally implemented (in an information apparatus 200 , external controller, servers etc). Raster image processor can be implemented as hardware, software, or a combination (not shown). As an example, raster image processor may be implemented in a software application or device driver in the information apparatus 200 . Examples of raster image processing operations include image and graphics interpretation, rasterization, scaling, segmentation, color space transformation, image enhancement, color correction, halftoning, compression etc.
[0118] FIG. 4A illustrates a block diagram of one conventional printing system or printer 400 A that includes a printer controller 410 and a printer engine 420 A. The printer controller 410 includes an interpreter 402 and a raster image processor 406 , and the printer engine 420 includes memory buffer 424 A and a marking engine 426 A.
[0119] Marking engine may use any of a variety of different technologies to transfer a rasterized image to paper or other media or, in other words, to transfer colorant to a substrate. The different marking or printing technologies that may be used include both impact and non-impact printing. Examples of impact printing may include dot matrix, teletype, daisywheel, etc. Non-impact printing technologies may include inkjet, laser, electrostatic, thermal, dye sublimation, etc.
[0120] The marking engine 426 and memory buffer 424 of a printer form its printer engine 420 , which may also include additional circuitry and components, such as firmware, software or chips or chipsets for decoding and signal conversion, etc. Input to a printer engine 420 is usually a final rasterized printer-engine print data generated by a raster image processor 406 . Such input is usually device dependent and printer or printer engine specific. The printer engine 420 may take this device dependent input and generate or render output pages (e.g. with ink on a substrate).
[0121] When a raster image processor is located inside an output device 220 , it is usually included in a printer controller 410 (as shown in FIG. 4A ). A printer controller 410 may interpret, rasterize, and convert input print data in the form of a page description language (e.g., PostScript, PCL), markup language (e.g., XML, HTML) or other special document format or language (e.g. PDF, EMF) into printer-engine print data which is a final format, language or instruction that printer engine 420 A can understand.
[0122] Print data sent to a printer with printer controller 410 is usually in a form (e.g. postscript) that requires further interpretation, processing or conversion. A printer controller 410 receives the print data, interprets, process, and converts the print data into a form that can be understood by the printer engine 420 A. Regardless of the type of print data, conventionally, a user may need a device-specific driver in his or her information apparatus 200 in order to output the proper language, format, or file that can be accepted by a specific printer or output device 220 .
[0123] FIG. 4B illustrates another conventional output device 400 B. Output device 400 B may be a printing device, a display device, a projection device, or a sound device. In the case that the output device is a printing device or a printer, the printer with reference to FIG. 4B does not include a printer controller 410 . As an example, printer 400 B may be a low-cost printer such as a desktop inkjet printer. RIP operations in this example may be implemented in a software application or in a device driver included in an information apparatus 200 . The information apparatus 200 generates device dependent output data (or print data in case of a printer) by rasterizing and converting a digital document into output data (e.g. into a compressed CMKY data with one or more bits per pixel) that can be understood by an output engine (or printer engine in case of a printer) 420 B.
[0124] Regardless of type or sophistication level, different output device 220 conventionally needs different printer drivers or output management applications in an information apparatus 200 to provide output capability. Some mobile devices with limited memory and processing power may have difficulty storing multiple device drivers or perform computational intensive RIP operations. It may also be infeasible to install a new device dependent or specific printer driver each time there is a need to print to a new printer. To overcome these difficulties, present invention provides several improvements to output device 220 or output system 250 as described in detail next.
[0125] In present invention, output device 220 may include an output controller 230 to help managing communication and negotiation processes with an information apparatus 200 and to process output data. Output controller 230 may include dedicated hardware or software or combination of both for at least one output device 220 . Output controller 230 may be internally installed, or externally connected to one or more output devices 220 . The output controller 230 is sometimes referred to as a print server or output server.
[0126] FIGS. 5A and 5B illustrate two exemplary internal implementations of the output controller 230 of present invention. FIG. 5A illustrates the implementation of an output controller 230 inside a conventional printer with reference to FIG. 4A , which includes a conventional printer controller 410 ( 5 A). The output controller 230 ( 5 A) includes an interpreter 510 A component for decoding the intermediate output data of present invention; and a converter component 530 A for converting one or more decoded output images into a printer-controller print data that is suitable for input to the printer controller 410 ( 5 A). An optional image processing component 520 A may be included in the output controller 230 ( 5 A).
[0127] FIG. 5B illustrates the implementation of an output controller 230 included internally in a conventional output device 220 with reference to FIG. 4B , which does not include a printer controller. The output controller 230 ( 5 B) includes an interpreter 510 B component for decoding the intermediate output data of present invention; an image processor 520 B component for performing one or more image processing operations such as color space conversion, color matching and digital halftoning; and an optional encoder 530 B component to conform the processed output images into an output-engine output data that is suitable for input to the output engine 420 B if the result of the image processing is not already in required form suitable for the output engine 420 B.
[0128] In one implementation, output device 220 may include a communication unit 550 or adapter to interface with information apparatus 200 . Output device 220 may sometimes include more than one communication unit 550 in order to support different interfaces, protocols, or communication standards with different devices. For example, output device 220 may communicate with a first information apparatus 200 through a Bluetooth interface while communicating with a second information apparatus 200 through a parallel interface. Examples of hardware components of a wireless communication unit are described in greater detail below with reference to FIGS. 8A and 8B .
[0129] In one embodiment, output controller 230 does not include a communication unit, but rather utilizes or manages a communication unit residing in the associated output device 220 such as the illustration in FIG. 5 . In another embodiment, output controller 230 may include or provide a communication unit to output device 220 as shown in FIG. 6 . For example, an output controller 230 with a wireless communication unit may be installed internally or connected externally to a legacy printer to provide it with wireless communication capability that was previously lacking.
[0130] FIG. 6 includes three functional block diagrams illustrating the hardware/software components of output controller 230 in three different implementations. Each components of an output controller 230 may include software, hardware, or combination. For example, an output controller 230 may include components using one or more or combinations of an application-specific integrated circuit (ASIC), a digital signal processor (DSP), a field programmable gate array (FPGA), firmware, system on a chip, and various communication chip sets. Output controller 230 may also contain embedded processors 670 A with software components or embedded application software to implement its feature sets and functionalities.
[0131] Output controller 230 may contain an embedded operating system 680 . With an operating system, some or all functionalities and feature sets of the output controller 230 may be provided by application software managed by the operating system. Additional application software may be installed or upgraded to newer versions in order to, for example, provide additional functionalities or bug fixes. FIG. 6A and FIG. 6C illustrates examples of implementation with an operating system 680 while FIG. 6B illustrates an example without the operating system 680 or the optional embedded processor 670 .
[0132] Output controller 230 typically includes a memory unit 640 , or may share a memory unit with, for example, printer controller 410 . The memory unit and storage unit, such as ROM, RAM, flash memory and disk drive among others, may provide persistent or volatile storage. The memory unit or storage unit may store output device profiles, objects, codes, instructions or data (collectively referred to as software components) that implement the functionalities of the output controller 230 . Part of the software components (e.g., output device profile) may be uploaded to information apparatus 200 during or before a data output operation.
[0133] An output controller 230 may include a processor component 670 A and 670 C, a memory component 650 , an optional storage component 640 , and an optional operating system component 680 . FIG. 6 shows one architecture or implementation where the memory 650 , storage 640 , processor 670 , and operating system 680 components, if exist, can be share or accessed by other operational components in the output controller 230 such as the interpreter 610 and image processor 650 . FIG. 6 shows two communication units 660 A and 660 B included in the output controller 230 ; however, the output controller 230 of present invention may include any number of communication units 660 . It is also possible that the output controller does not contain any communication unit but rather utilizes the communication unit of an output device.
[0134] The output controller 230 may be connected externally to an output device 220 or integrated internally into the output device 220 . FIGS. 5A and 5B illustrate implementations of output controller 230 inside an output device 220 . The output controller 230 , however, may also be implemented as an external box or station that is wired or wirelessly connected to an output device 220 . An output controller 230 implemented as an external box or station to an output device 220 may contain its own user interface. One example of such an implementation is a print server connected to an output device 220 in an output system 250 . Another configuration and implementation is to integrate or combine the functionalities of an output controller 230 with an existing printer controller 410 (referred to as “combined controller”) if the output device 220 is a printer as shown with reference to FIG. 7C or 7F . A combined controller can also be internally integrated or externally connected to output device 220 , and include functionalities of both printer controller 410 (e.g., input interpretation and or raster image processing) and output controller 230 of present invention. One advantage of this configuration is that the functionalities or components of output controller 230 and printer controller 410 may share the same resources, such as processing unit, memory unit, etc. FIG. 6C illustrates an example of a combined controller implementation or output controller 230 where the printer controller 410 C, interpreter 610 C and converter 630 C shares the use of the processor 670 C, memory 650 C and storage 640 C, managed by an operating system 680 C. Various exemplary implementations and configurations of an output controller 230 with respect to an output device 220 or output system 250 are illustrated in further detail with reference to FIG. 7 .
[0135] Other possible implementations of output controller 230 may include, for example, a conventional personal computer (PC), a workstation, and an output server or print server. In these cases, the functionalities of output controller 230 may be implemented using application software installed in a computer (e.g., PC, server, or workstation), with the computer connected with a wired or wireless connection to an output device 220 . Using a PC, server, workstation, or other computer to implement the feature sets of output controller 230 with application software is just another possible embodiment of the output controller 230 and in no way departs from the spirit, scope and process of the present invention.
[0136] The difference between output controller 230 and printer controller 410 should be noted. Printer controller 410 and output controller 230 are both controllers and are both dedicated hardware and or software for at least one output device 220 . Output controller 230 refers to a controller with feature sets, capabilities, and functionalities of the present invention. A printer controller 410 may contain functions such as interpreting an input page description language, raster image processing, and queuing, among others. An output controller 230 may include part or all of the features of a printer controller 410 in addition to the feature sets, functionalities, capabilities, and processes of present invention.
[0137] Functionalities and components of output controller 230 for the purpose of providing universal data output may include or utilize:
Components and operations to receive output data from a plurality of information apparatus 200 ; the output data may include an intermediate output data containing at least one rasterized image related to the data content intended for output. Components and operations to interpret and/or decode the intermediate output data. Components and operations to process the intermediate output data. Such components and operations may include image processing functions such as scaling, segmentation, color correction, color management, GCR, image enhancement, decompression, decryption, and or halftoning among others. Components and operations to generate an output-engine output data, the output-engine output data being in an output data format acceptable for input to an output engine. Components and operations to send the output-engine output data to the output engine.
[0143] When associated with an output device 220 that includes a printer controller 410 , the output controller of present invention may further include or utilize:
Components and operations to convert the intermediate output data into a printer-controller print data (e.g. a PDL such as PostScript and PCL), the printer-controller print data being in a format acceptable to a printer controller. Components and operations to send printer-controller print data to one or more printer controllers.
[0146] In addition to the above components and functionalities, output controller 230 may further include one or more of the following:
Components and operations to communicate with one or more information apparatus 200 through a wired or wireless interface. Components and operations to communicate and or manage a communication unit included in the output controller 230 or output device 220 . Components and operations to store at least part of an output device profile (a printer profile in case of a printer) in a memory component. Components and operations to respond to service request from an information apparatus 200 by transmitting at least part of an output device profile to the information apparatus requesting service. The output controller 230 may transmit the output device profiles or object in one or multiple sessions. Components and operations to broadcast or advertise the services provided by a host output device 220 to one or more information apparatus 200 that may request such services. Components and operations to implement payment processing and management functions by, for example, calculating and processing payments according to the services requested or rendered to a client (information apparatus 200 ). Components and operations to provide a user interface such as display screen, touch button, soft key, etc. Components and operations to implement job management functions such as queuing and spooling among others. Components and operations to implement security or authentication procedures. For example, the output controller 230 may store in its memory component (or shared memory component) an access control list, which specifies what device or user may obtain service from its host (or connected) output device 220 . Therefore, an authorized information apparatus 200 may gain access after confirming with the control list.
[0156] When output controller 230 is implemented as firmware, or an embedded application, the configuration and management of the functionalities of output controller 230 may be optionally accomplished by, for example, using controller management software in a host computer. A host computer may be a desktop personal computer (PC), workstation, or server. The host computer may be connected locally or through a network to the output device 220 or the controller 230 . Communication between the host computer and the output controller 230 can be accomplished through wired or wireless communication. The management application software in the host computer can manage the settings, configurations, and feature sets of the output controller 230 . Furthermore, host computer's configuration application may download and or install application software, software components and or data to the output controller 230 for the purpose of upgrading, updating, and or modifying the features and capabilities of the output controller 230 .
[0157] Output device 220 in one implementation includes or is connected to output controller 230 described above. Therefore, functionalities and feature sets provided by output controller 230 are automatically included in the functionalities of output device 220 . The output device 220 may, however, implement or include other controllers and/or applications that provide at least partially the features and functionalities of the output controller 230 .
[0158] Therefore, the output device 220 may include some or all of the following functionalities:
Components and operations to receive multiple service requests or queries (e.g., a service request, a data query, an object or component query etc.) from a plurality of information apparatus 200 and properly respond to them by returning components, which may contain data, software, instructions and/or objects. Components and operations to receive output data from a plurality of information apparatus 200 ; the output data may include an intermediate output data containing one or more rasterized image related to the content intended for output. Components and operations to interpret and/or decoding the intermediate output data. Components and operations to process and/or convert the intermediate output data into a form (e.g. output-engine print data) suitable for rendering at an output engine associated with the output device. Components and operations to render a representation or an image related to the content onto an output medium (e.g. substrate or a display screen).
[0164] An output device 220 may further comprise optionally one or more of the following functionalities:
Components and operations for establishing and managing a communication link with an information apparatus 200 requesting service; the communication link may include wired or wireless communication. Components and operations for storing at least part of an output device profile (e.g. printer profile) in a memory component. Components and operations to provide at least part of an output device profile (e.g., printer profile in case of a printer) to one or more information apparatus 200 requesting service. The output device 220 may transmit the output device profile in one or multiple sessions. Components and operations to advertise or broadcast services provided or available to one or more information apparatus 200 . Components and operations to implement payment processing and management functions by, for example, calculating and processing payments according to the services requested by or rendered to a client (information apparatus 200 ). Components and operations to implement job management functionalities such as queuing and spooling among others. Components and operations to provide a user interface such as display screen touch button, soft key, power switch, etc. Components and operations to implement security or authentication procedures. For example, the output device 220 may store in its memory component (or a shared memory component) an access control list, which specifies what device or user may obtain service from it. Therefore, an authorized information apparatus 200 may gain access after confirming with the control list.
[0173] FIGS. 7A-7F illustrate various alternative configurations and implementations of output controller 230 with respect to an output device 230 . Printer is sometimes used as an exemplary output device 230 to demonstrate the various configurations. It should be understood, however, the output device 230 of present invention is not limited to printers.
[0174] As described with reference to FIG. 4 ., a printer may or may not contain a printer controller 410 . Printer 400 A that includes a printer controller 410 typically has higher speed and is more expensive than printer 400 B which does not include a printer controller 410 .
[0175] FIG. 7A shows that output controller 230 may be cascaded externally to one or more printers (only one shown). Information apparatus 200 communicates with output controller 230 A, which then communicates with output device 220 such as a printer 220 A. The communication link between the output controller 230 A and the printer 220 A may be a wired link or a wireless link, as described above. FIGS. 6A and 6B illustrates two examples of functional component design of the output controller that can implement the configuration illustrated in FIG. 7A . The Image processor 620 in this implementation is optional.
[0176] FIG. 7B shows another implementation in which output controller 230 B is installed as one or more circuit boards or cards internally inside printer 220 B. The output controller 230 B may co-exist with printer controller 410 and other components of the printer 220 B. One example of this implementation is to connect output controller 230 B sequentially with the printer controller 310 . FIG. 5A shows as an example of an implementation.
[0177] FIG. 7C shows another implementation in which the functionalities of output controller 230 and printer controller 410 are combined into a single controller (referred to as “combined controller”) 230 C. In this implementation, it is possible to reduce the cost of material when compared to implementing two separate controllers as shown in FIG. 7B . As an example, the combined controller 230 C may share the same processors, memories, and storages to run the applications and functionalities of the two types of controllers and therefore, may have lower component costs when compared to providing two separate controllers. FIG. 6C illustrates an example of a combined controller functional component implementation.
[0178] Some printers do not include a raster image processor or printer controller 410 , as illustrated in FIG. 4B . An example of this type of printer is a lower cost desktop inkjet printer. Input to an inkjet printer may consist of a compressed CMYK data (proprietary or published) with one or more bits per pixel input. To output to a printer that does not include a printer controller, a device specific software application or a printer driver is typically required in an information apparatus 200 to perform raster image processing operations. Accordingly, output controller 230 can be implemented into a variety of output devices 220 and/or output systems 250 including printers that do not have printer controllers for performing raster image processing operations.
[0179] FIG. 7D and FIG. 7E illustrate two implementations of output controller 230 in an output device 220 or system 250 . The output device 230 or system 250 may include a display device, a projection device, an audio output device or a printing device. In the case when the output device 220 D or 220 E is a printer, it does not include a printer controller. FIG. 7D illustrates an implementation of an output controller 230 D installed as an external component or “box” to output device 220 D. For example, the output controller 230 may be implemented as an application in a print server or as a standalone box or station. In this configuration, some or all of raster image processing operations may be implemented in the output controller 230 D. Output controller 230 D receives intermediate output data from an information apparatus 200 and generates output-engine output data that is acceptable to the output engine included in the output device 220 D. The output controller 230 D may send the output data to the output device 220 D through a wired or wireless communication link or connection. FIGS. 6A and 6B illustrates two example of functional component design of the output controller that can implement the configurations for both FIGS. 7D and 7E .
[0180] FIG. 7E shows a fifth implementation of output controller 230 E in which the output controller 230 E is incorporated within output device 220 E as one or more circuit boards or cards and may contain software and applications running on an embedded processor. As with output device 220 D ( FIG. 7D ), output device 220 E does not include a printer controller 410 . Accordingly, the output controller 230 E implements the functionalities and capabilities of present invention that may include part of or complete raster imaging processing operation.
[0181] FIG. 7F shows a sixth implementation, an external combined controller 230 F that integrates the functionalities of a printer controller 310 and an output controller into a single external combined controller component or “box” 230 F. The two controller functions may share a common processor as well as a common memory space to run applications of the two types of controllers. Under this configuration, either information apparatus 200 or the combined controller 230 F could perform or share at least part of raster image processing functionality. FIG. 6C shows an example of functional components of a combined controller 230 F.
[0182] Another implementation of the combined controller 230 F shown in FIG. 7F is to use an external computing device (PC, workstation, or server) running one or more applications that include the functionality of output controller 230 and printer controller 410 .
[0183] The above are examples of different implementations and configurations of output controller 230 . Other implementations are also possible. For example, partial functionalities of output controller 230 may be implemented in an external box or station while the remaining functionalities may reside inside an output device 220 as a separate board or integrated with a printer controller 410 . As another example, the functionalities of output controller 230 may be implemented into a plurality of external boxes or stations connected to the same output device 220 . As a further example, the same output controller 230 may be connected to service a plurality of output devices 220
[0184] FIGS. 8A and 8B are block diagrams illustrating two possible configurations of hardware/software components of wireless communication units. These wireless communication units can be implemented and included in information apparatus 200 , in output controller 230 and in output device 220 . Referring to FIG. 8A , a radio adapter 800 may be implemented to enable data/voice transmission among devices (e.g., information apparatus 200 and output device 220 ) through radio links. An RF transceiver 814 coupled with antenna 816 is used to receive and transmit radio frequency signals. The RF transceiver 814 also converts radio signals into and from electronic signals. The RF transceiver 814 is connected to an RF link controller 810 by an interface 812 . The interface 812 may perform functions such as analog-to-digital conversion, digital-to-analog conversion, modulation, demodulation, compression, decompression, encoding, decoding, and other data or format conversion functions.
[0185] RF link controller 810 implements real-time lower layer (e.g., physical layer) protocol processing that enables the hosts (e.g., information apparatus 200 , output controller 230 , output device 220 , etc.) to communicate over a radio link. Functions performed by the link controller 810 may include, without limitation, error detection/correction, power control, data packet processing, data encryption/decryption and other data processing functions.
[0186] A variety of radio links may be utilized. A group of competing technologies operating in the 2.4 GHz unlicensed frequency band is of particular interest. This group currently includes Bluetooth, Home radio frequency (Home RF) and implementations based on IEEE 802.11 standard. Each of these technologies has a different set of protocols and they all provide solutions for wireless local area networks (LANs). Interference among these technologies could limit deployment of these protocols simultaneously. It is anticipated that new local area wireless technologies may emerge or that the existing ones may converge. Nevertheless, all these existing and future wireless technologies may be implemented in the present invention without limitation, and therefore, in no way depart from the scope of present invention.
[0187] Among the currently available wireless technologies, Bluetooth may be advantageous because it requires relatively lower power consumption and Bluetooth-enabled devices operate in piconets, in which several devices are connected in a point-to-multipoint system. Referring to FIG. 8B , one or more infrared (IR) adapters 820 may be implemented to enable data transmission among devices through infrared transmission. The IR adapters 820 may be conveniently implemented in accordance with the Infrared Data Association (IrDA) standards and specifications. In general, the IrDA standard is used to provide wireless connectivity technologies for devices that would normally use cables for connection. The IrDA standard is a point-to-point (vs. point-to-multipoint as in Bluetooth), narrow angle, ad-hoc data transmission standard.
[0188] Configuration of infrared adapters 820 may vary depending on the intended rate of data transfer. FIG. 8B illustrates one embodiment of infrared adapter 820 . Transceiver 826 receives/emits IR signals and converts IR signals to/from electrical signals. A UART (universal asynchronous receiver/transmitter) 822 performs the function of serialization/deserialization, converting serial data stream to/from data bytes. The UART 822 is connected to the IR transceiver 826 by encoder/decoder (ENDEC) 824 . This configuration is generally suitable for transferring data at relatively low rate. Other components (e.g., packet framer, phase-locked loop) may be needed for higher data transfer rates.
[0189] FIGS. 8A and 8B illustrate exemplary hardware configurations of wireless communication units. Such hardware components may be included in devices (e.g., information apparatus 200 , output controller 230 , output device 220 , etc.) to support various wireless communications standards. Wired links, however, such as parallel interface, USB, Firewire interface, Ethernet and token ring networks may also be implemented in the present invention by using appropriate adapters and configurations.
[0190] FIG. 9 is a logic flow diagram of an exemplary raster imaging process (RIP) 902 that can implement the universal output method of present invention. Content (e.g. digital document) 900 may be obtained and/or generated by an application running in an information apparatus 200 . For example, a document browsing application may allow a user to download and or open digital document 900 stored locally or in a network node. As another example, a document creating or editing application may allow a user to create or edit digital documents in his/her information apparatus 200 .
[0191] A client application 210 in the information apparatus may be in the form of a device driver, invoked by other applications residing in the information apparatus 200 to provide output service. Alternatively, the client application 210 of present invention may be an application that includes data output and management component, in addition of other functionalities such as content acquisitions, viewing, browsing, and or editing etc. For example, a client application 210 in an information apparatus 200 may itself include components and functions for a user to download, view and or edit digital document 900 in addition of the output management function described herein.
[0192] Raster image process method 902 allows an information apparatus 200 such as a mobile device to pervasively and conveniently output content (e.g. a digital document) to an output device 220 or system 250 that includes an output controller 230 . A client application 210 in an information apparatus 200 may perform part of raster image processing operations (e.g. rasterization operation). Other operations of raster image processing such as halftoning can be completed by the output device 220 or by the output controller 230 . In conventional data output methods, raster image processing is either implemented entirely in an information apparatus (e.g. a printer that does not include a printer controller with reference to FIG. 1A ) or in an output device (e.g. a printer that includes a printer controller with reference to FIG. 1B ). Present invention provides a more balanced approach where raster image process operations are shared between an information apparatus 200 and an output device 220 or system 250 . For example, content 600 may be processed (e.g. raster image processed) by different components or parts of an overall output system from a client application 210 to an output controller 230 before being sent to an output engine or a printer engine for final output in step 960 . Because the raster image processing operations are not completely implemented in the information apparatus 200 , there is less processing demand on the information apparatus 200 . Therefore, present RIP process may enable additional mobile devices with less memory and processing capability to have data output capability.
[0193] In step 910 , rasterization operation, a content (e.g. digital document), which may include text, graphics, and image objects, is conformed or rasterized to image form according to one or more rasterization parameters such as output size, bit depth, color space, resolution, number of color channels etc. During the rasterization operation, text and vector graphics information in the content are rasterized or converted into image or bitmap information according to a given set of rasterization parameters. Image information in the content or digital document may be scaled and or interpolated to fit a particular output size, resolution and bit depth etc. The rasterization parameters are in general device dependent, and therefore may vary according to different requirements and attributes of an output device 220 and its output engine. There are many ways to obtain device dependent rasterization parameters, as described in more detail below with reference to FIG. 12A . Device dependent rasterization parameters, in one example, may be obtained from an output device profile stored in an information apparatus 200 , an output device 220 or an output controller 230 .
[0194] In an alternative implementation, rasterization parameters may be predetermined by a standard or specification. In this implementation, in step 910 the content 900 is rasterized to fit or match this predefined or standard rasterization parameters. Therefore, the rasterized output image becomes device independent. One advantage of being device independent is that the rasterized output image is acceptable with controllers, devices and/or output devices implemented or created with the knowledge of such standard or specification. A rasterized image with predefined or standardized attributes is usually more portable. For example, both the client application 210 and output device 220 or its output controller 230 may be preprogrammed to receive, interpret, and or output raster images based on a predefined standard and/or specification.
[0195] Occasionally, a predefined standard or specification for rasterization parameters may require change or update. One possible implementation for providing an easy update or upgrade is to store information and related rasterization parameters in a file or a profile instead of hard coding these parameters into programs, components or applications. Client application 210 , output controller 230 , and/or the output device 220 can read a file or a profile to obtain information related to rasterization parameters. To upgrade or update the standard specification or defaults requires only replacing or editing the file or the profile instead of replacing a software application or component such as the client application 210 .
[0196] In step 920 the rasterized content in image form is encoded into an intermediate output data. The intermediate output data, which describes the output content, may include image information, instructions, descriptions, and data (e.g. color profile). The rasterized output image may require further processing including one or more of compression, encoding, encryption, smoothing, image enhancement, segmentation, color correction among others before being stored into the intermediate output data. The output image in the intermediate output data may be encoded in any image format and with any compression technique such as JPEG, BMP, TIFF, JBIG etc. In one preferred embodiment, a mixed raster content (MRC) format and its related encoding and/or compression methods are used to generate the output image. The advantages of using MRC over other image formats and techniques may include, for example, better compression ratio, better data information retention, smaller file size, and or relatively better image quality among others.
[0197] In step 930 , the intermediate output data is transmitted to the output device 220 or output system 250 for further processing and final output. The transmission of the intermediate output data may be accomplished through wireless or wired communication links between the information apparatus 200 and the output device 220 and can be accomplished through one or multiple sessions.
[0198] In step 940 , the output device 220 or output system 250 receives the transmitted intermediate output data. The output device 220 or output system 250 may include an output controller 230 to assist communicating with the information apparatus 200 and/or processing the intermediate output data. Output controller 230 may have a variety of configurations and implementations with respect to output device 220 as shown in FIG. 7A-7F . Interpretation process 940 may include one or more of parsing, decoding, decompression, decryption, image space conversion among other operations if the received intermediate output data requires such processing. An output image is decoded or retrieved from the intermediate output data and may be temporarily stored in a buffer or memory included in the output device/output system ( 220 / 250 ) or output controller 230 for further processing.
[0199] If the intermediate output data includes components with MRC format or encoding techniques, it may contain additional segmented information (e.g. foreground and background), which can be used to enhance image quality. For example, different techniques or algorithms in scaling, color correction, color matching, image enhancement, anti-aliasing and or digital halftoning among others may be applied to different segments or layers of the image information to improve output quality or maximize retention or recovery of image information. Multiple layers may later be combined or mapped into a single layer. These image processing and conversion components and/or operations can be included in the output controller 230 of present invention.
[0200] In step 950 , the decoded or retrieved output image from the intermediate output data may require further processing or conversion. This may include one or more of scaling, segmentation, interpolation, color correction, GCR, black generation, color matching, color space transformation, anti-aliasing, image enhancement, image smoothing and or digital halftoning operations among others.
[0201] In an embodiment where the output device 220 does not include a printer controller, an output controller 230 or an output device 220 that includes output controller, after performing the remaining portion of RIP operations (e.g. color space conversion and halftoning) on the output image, may further convert the output data in step 950 into a form that is acceptable for input to a printer engine for rendering.
[0202] In an alternative embodiment where the output device 220 or the output system 250 includes a conventional printer controller, the output controller may simply decodes and or converts the intermediate output data (print data in this example) into format or language acceptable to the printer controller. For example, a printer controller may require as input a page description language (e.g. PostScript, PCL, PDF, etc.), a markup language (HTML, XML etc) or other graphics or document format. In these cases, the output controller 230 may interpret, decompress and convert the intermediate print data into an output image that has optimal output resolution, bit depth, color space, and output size related to the printer controller input requirements. The output image is then encoded or embedded into a printer-controller print data (e.g. a page description language) and sent to the printer controller. A printer-controller print data is a print data that is acceptable or compatible for input to the printer controller. After the printer controller receives the printer-controller print data, the printer controller may further perform operations such as parsing, rasterization, scaling, color correction, image enhancement, halftoning etc on the output image and generate an appropriate printer-engine print data suitable for input to the printer engine.
[0203] In step 960 , the output-engine output data or printer-engine print data generated by the output controller 230 or the printer controller in step 950 is sent to the output engine or printer engine of the output device for final output.
[0204] FIG. 10 illustrates a flow diagram of a universal data output process of the present invention that includes the raster image processing illustrated with reference to FIG. 9 . A universal data output process allows an information apparatus 200 to pervasively output content or digital document to an output device. The data output process may include or utilize:
A user interface component and operation where a user initiates an output process and provides an indication of the selected output content (e.g. digital document) for output. A client application component or operation that processes the content indicated for output, and generates an intermediate output data. The intermediate output data may include at least partly a raster output image description related to the content. An information apparatus component or operation that transmits the intermediate output data to one or more selected output device 220 . An output device component (e.g. output controller) or operation that interprets the intermediate output data and may further process or convert the output data into a form more acceptable to an output engine for rendering of the content.
[0209] With reference to FIG. 10 , a user in step 1000 may initiate the universal output method or process 1002 . Typically, a user initiates the output process by invoking a client application 210 in his/her information apparatus 200 . The client application 210 may be launched as an independent application or it may be launched from other applications 205 (such as from a document browsing, creating or editing application) or as part of or component of or a feature of another application 205 residing in the same information apparatus 200 . When launched from another application 205 , such as the case when the client application is a device driver or helper application, the client application 210 may obtain information, such as the content (e.g. digital document) from that other application 205 . This can be accomplished, for example, by one or combinations of messages or facilitated through an operating system or a particular object or component model etc.
[0210] During output process 1002 , a user may need to select one or more output devices 220 for output service. An optional discovery process step 1020 may be implemented to help the user select an output device 220 . During the discovery process step 1020 , a user's information apparatus 200 may (1) search for available output devices 220 ; (2) provide the user with a list of available output devices 220 ; and (3) provide means for the user to choose one or more output devices 220 to take the output job. An example of a discovery process 1020 is described below in greater detail with reference to FIG.
[0211] The optional discovery process 1020 may sometimes be unnecessary. For example, a user may skip the discovery process 1020 if he or she already knows the output device (e.g., printer) 220 to which the output is to be directed. In this case, the user may simply connect the information apparatus 200 to that output device 220 by wired connections or directly point to that output device 220 in a close proximity such as in the case of infrared connectivity. As another example, a user may pre-select or set the output device or devices 220 that are used frequently as preferred defaults. As a result, the discovery process 1020 may be partially or completely skipped if the default output device 220 or printer is found to be available.
[0212] In stage 1030 , the client application may interact with output device 220 , the user, and/or other applications 205 residing in the same information apparatus 200 to (1) obtain necessary output device profile and/or user preferences, (2) perform functions or part of raster image processing operations such as rasterization, scaling and color correction, and/or (3) convert or encode at least partially the rasterized content (e.g. digital document) into an intermediate output data. The processing and generation of the intermediate output data may reflect in part a relationship to an output device profile and/or user preferences obtained, if any. The intermediate output data generated by the client application 210 is then transmitted through wired or wireless local communication link(s) 240 to the output controller 230 included or associated with the selected output device 220 or output system 250 . An exemplary client application process is described in greater detail with reference to FIG. 12 .
[0213] In step 1040 , the output controller 230 of present invention receives the intermediate output data. In the case where the selected output device 230 does not include a printer controller, the output controller 230 of present invention may further perform processing functions such as parsing, interpreting, decompressing, decoding, color correction, image enhancement, GCR, black generation and halftoning among others. In addition, the output controller 230 may further convert or conform the intermediate output data into a form or format suitable for the output engine (e.g. printer engine in the case of a printer). The generated output-engine output data from the output controller is therefore, in general, device dependent and acceptable for final output with the output engine (or the printer engine in case of a printer) included in the selected output device 220 or output system 250 .
[0214] In the case where the selected output device 220 is a printer, and when the printer includes or is connected to a printer controller, the output controller 230 may generate the proper language or input format required to interface with the printer controller (referred to as printer-controller print data). The printer controller may for example require a specific input such as a page description language (PDL), markup language, or a special image or graphics format. In these cases, the output controller 230 in step 1040 may interpret and decode the intermediate output data, and then convert the intermediate output data into the required printer-controller print data (e.g. PDL such as PostScript or PCL). The printer-controller print data generated by the output controller is then sent to the printer controller for further processing. The printer controller may perform interpretation and raster image processing operations among other operations. After processing, the printer controller generates a printer-engine print data suitable for rendering at the printer engine.
[0215] In either case, the output controller 230 or printer controller generates an output-engine output data that is suitable for sending to or interfacing with the output engine or the printer engine included in the output device for rendering. The output data may be temporarily buffered in components of the output device 220 . An implementation of the output device process 1040 is described in greater detail with reference to FIG. 13 .
[0216] The steps included in the universal pervasive output process 1002 may proceed automatically when a user requests output service. Alternatively, a user may be provided with options to proceed, cancel, or input information at each and every step. For example, a user may cancel the output service at any time by, for example, indicating a cancellation signal or command or by terminating the client application 210 or by shutting down the information apparatus 200 etc
[0217] FIG. 11 is a flow diagram of an example of a discovery process 720 , which may be an optional step to help a user locate one or more output devices 220 for an output job. The discovery process 1020 may, however, be skipped partially or entirely. Implementation of discovery process 1020 may require compatible hardware and software components residing in both the information apparatus 200 and the output device 220 . The information apparatus 200 may utilize the client application 210 or other application 205 in this process. The discovery process 1020 may include:
An information apparatus 200 communicating with available output devices 220 to obtain information and attributes relating to the output device 220 and or its services such as output device capability, feature sets, service availability, quality of service, condition. An Information apparatus 200 provides the user information on each available and or compatible output devices 220 . A user selects or the client application 210 (automatically or not) selects one or more output devices 220 for the output service from the available or compatible output devices 220 .
[0221] Various protocols and or standards may be used during discovery process 1020 . Wireless communication protocols are preferred. Wired communication, on the other hand, may also be implemented. Examples of applicable protocols or standards may include, without limitation, Bluetooth, HAVi, Jini, Salutation, Service Location Protocol, and Universal Plug-and-play among others. Both standard and proprietary protocols or combination may be implemented in the discovery process 1020 . However, these different protocols, standards, or combination shall not depart from the spirit and scope of present invention.
[0222] In one implementation an application (referred here for simplicity of discussion as a “communication manager,” not shown) residing in the information apparatus 200 helps communicate with output device 220 and manages service requests and the discovery process 1020 . The communication manager may be a part of or a feature of the client application 210 . Alternatively or in combination, the communication manager may also be a separate application. When the communication manager is a separate application, the client application 210 may have the ability to communicate, manage or access functionalities of the communication manager.
[0223] The discovery process 1020 may be initiated manually by a user or automatically by a communication manager when the user requests an output service with information apparatus 200 .
[0224] In the optional step 1100 , a user may specify searching or matching criteria. For example, a user may indicate to search for color printers and or printers that provide free service. The user may manually specify such criteria each time for the discovery process 1020 . Alternatively or in combination, a user may set default preferences that can be applied to a plurality of discovery processes 1020 . Sometimes, however, no searching criteria are required: the information apparatus 200 may simply search for all available output devices 220 that can provide output service.
[0225] In step 1101 , information apparatus 200 searches for available output devices 220 . The searching process may be implemented by, for example, an information apparatus 200 (e.g. with the assistance of a communication manager) multi-casting or broadcasting or advertising its service requests and waiting for available output devices 220 to respond. Alternatively or in combination, an information apparatus 200 may “listen to” service broadcasts from one or more output devices 220 and then identify the one or more output devices 220 that are needed or acceptable. It is also possible that multiple output devices 220 of the same network (e.g., LAN) register their services with a control point (not shown). A control point is a computing system (e.g., a server) that maintains records on all service devices within the same network. An information apparatus 200 may contact the control point and search or query for the needed service
[0226] In step 1102 , if no available output device 220 is found, the communication manager or the client application 210 may provide the user with alternatives 1104 . Such alternatives may include, for example, aborting the discovery process 1020 , trying discovery process 1020 again, temporarily halting the discovery process 1020 , or being notified when an available output device 220 is found. As an example, the discovery process 1020 may not detect any available output device 220 in the current wired/wireless network. The specified searching criteria (if any) are then saved or registered in the communication manager. When the user enters a new network having available output devices 220 , or when new compatible output devices 220 are added to the current network, or when an output device 220 becomes available for any reason, the communication manager may notify the user of such availability.
[0227] In step 1106 , if available output devices 220 are discovered, the communication manager may obtain some basic information, or part of or the entire output device profile, from each discovered output device 220 . Examples of such information may include, but not limited to, device identity, service charge, subscription, service feature, device capability, operating instructions, etc. Such information is preferably provided to the user through the user interface (e.g., display screen, speaker, etc.) of information apparatus 200 .
[0228] In step 1108 , the user may select one or more output devices 220 based on information provided, if any, to take the output job. If the user is not satisfied with any of the available output device 220 , the user may decline the service. In this case, the user may be provided with alternatives such as to try again in step 1110 with some changes made to the searching criteria. The user may choose to terminate the service request at any time. In step 1112 , with one or more output devices 220 selected or determined, the communication link between information apparatus 200 and the selected output device or devices 220 may be “locked”. Other output devices 220 that are not selected may be dropped. The output process 1020 may then proceed to the client application process of step 1030 of FIG. 10 .
[0229] FIG. 12A is a flow diagram of an exemplary client application process with reference to step 1030 of FIG. 10 . A client application process 1202 for universal output may include or utilize:
[0230] A client application 210 that obtains content (e.g. digital document) intended for output.
[0231] A client application 210 that obtains output device parameters (e.g. rasterization parameters, output job parameters). One example of implementation is to obtain the output device parameters from an output device profile (e.g. printer profile), which includes device dependent parameters. Such profile may be stored in an output controller 230 , output device 220 or information apparatus 200 .
[0232] A client application 210 that may optionally obtain user preferences through (1) user's input (automatic or manual) or selections or (2) based on preset preference or pre-defined defaults or (3) combination of the above.
[0233] A client application 210 that rasterizes at least part of the content intended for output (e.g. a digital document) according to one or more rasterization parameters obtained from previous steps such as through output device profile, user selection, predefined user preferences, predefined default or standard etc.
[0234] A client application 210 that generates an intermediate output data containing at least part of the rasterized image related at least partly to the content intended for output.
[0235] A client application that transmits the intermediate output data to an output device 220 or output controller 230 for further processing and or final output.
[0236] A client application 210 may obtain content (e.g. digital document) 900 or a pointer or reference to the content in many ways. In a preferred embodiment, the client application 210 is in the form of a device driver or an independent application, and the content or its reference can be obtained by the client application 210 from other applications 205 in the same information apparatus 200 . To illustrate an example, a user may first view or download or create a digital document by using a document browsing, viewing and or editing application 205 in his/her information apparatus 200 , and then request output service by launching the client application 210 as a device driver or helper application. The client application 210 communicates with the document browsing or editing application to obtain the digital document or reference to the digital document. As another example, the client application 210 is an independent application and it launches another application to help locate and obtain the digital document for output. In this case, a user may first launch the client application 210 , and then invoke another application 205 (e.g. document editing and or browsing application) residing in the same information apparatus 200 to view or download a digital document. The client application 210 then communicates with the document browsing or editing application to obtain the digital document for output.
[0237] In another embodiment, the client application 210 itself provides multiple functionalities or feature sets including the ability for a user to select the content (e.g. digital document) for output. For example, the client application 210 of present invention may provide a GUI where a user can directly input or select the reference or path of a digital document that the user wants to output.
[0238] In order to perform rasterization operation on content (e.g. digital document) 900 , the client application 210 in step 1210 needs to obtain device dependent parameters of an output device 220 such as the rasterization parameters. Device dependent parameters may be included in an output device profile. A client application 210 may obtain an output device profile or rasterization parameters in various ways. As an example, an output device profile or rasterization parameters can be obtained with one or combination of the following:
The client application communicates with an output device 220 to upload output device profile or information related to one or more rasterization parameters. The client application 210 obtains the output device profile from a network node (e.g. server). A user selects an output device profile stored in the user's information apparatus 200 . The client application 210 automatically retrieves or uses a default profile, predefined standard values or default values among others. The client application 210 obtains output device parameters by calculating, which may include approximation, based at least partly on the information it has obtained from one or combination of an output device 220 , a user, default values, and a network node.
[0244] It is important to note that step 1210 is an optional step. In some instance, part of or the entire output device profile or related device dependent information may have been already obtained by the client application 210 during the prior optional discovery process (step 1020 in FIG. 10 ). In this case, step 1210 may be partially or entirely skipped.
[0245] In one implementation, the client application 210 communicates with one or more output devices 220 to upload output device profiles stored in the memory or storage components of those one or more output devices 220 or their associated one or more output controllers 230 . In some instance, the uploaded output device profile may contain partially or entirely references or pointers to device parameters instead of the device parameters themselves. The actual output device parameters may be stored in a network node or in the information apparatus 200 , where they can be retrieved by the client application 210 or by other applications 205 using the references or pointers. It should be noted that a plurality of information apparatuses 200 may request to obtain output device profile or profiles from the same output device 220 at the same time or at least during overlapping periods. The output device 220 or its associated output controller 230 may have components or systems to manage multiple communication links and provide the output device profile or profiles concurrently or in an alternating manner to multiple information apparatuses 200 . Alternatively, an output device 220 may provide components or systems to queue the requests from different information apparatuses 200 and serve them in a sequential fashion according to a scheme such as first come first served, quality of service, etc. Multi-user communication and service management capability with or without queuing or spooling functions may be implemented by, for example, the output controller 230 as optional feature sets.
[0246] In another implementation, one or more output device profiles may be stored locally in the information apparatus 200 . The client application 210 may provide a GUI where a user can select a profile from a list of pre-stored profiles. As an example, the GUI may provide the user with a list of output device names (e.g. makes and models), each corresponding to an output device profile stored locally. When the user selects an output device 220 , the client application 210 can then retrieve the output device profile corresponding to the name selected by the user.
[0247] In certain cases, during a discovery or communication process described earlier, the client application 210 may have already obtained the output device ID, name, or reference or other information in a variety of ways described previously. In this case, the client application 210 may automatically activate or retrieve an output device profile stored in the information apparatus 200 based on the output device ID, name, or reference obtained without user intervention.
[0248] In yet another implementation, the client application 210 may use a set of pre-defined default values stored locally in a user's information apparatus 200 . Such defaults can be stored in one or more files or tables. The client application 210 may access a file or table to obtain these default values. The client application 210 may also create or calculate certain default values based on the information it has obtained during previous steps (e.g. in optional discovery process, based on partial or incomplete printer profile information obtained, etc). A user may or may not have an opportunity to change or overwrite some or all defaults.
[0249] Finally, if, for any reason, no device dependent information is available, the client application 210 may use standard output and rasterization parameters or pre-defined default parameters. The above illustrates many examples and variations of implementation, these and other possible variations in implementation do not depart from the scope of the present invention.
[0250] In step 1220 , the client application 210 may optionally obtain user preferences. In one exemplary implementation, the client application 210 may obtain user preferences with a GUI (graphical user interface). For simplicity, a standard GUI form can be presented to the user independent of the make and model of the output device 220 involved in the output process. Through such an interface, the user may specify some device independent output parameters such as page range, number of cards per page, number of copies, etc. Alternatively or in combination, the client application 210 may also incorporate output device-dependent features and preferences into the GUI presented to the user. The device-dependent portion of the GUI may be supported partly or entirely by information contained in the output device profile obtained through components and processes described in previous steps. To illustrate, device dependent features and capabilities may include print quality, color or grayscale, duplex or single sided, output page size among others.
[0251] It is preferred that some or all components, attributes or fields of user preferences have default values. Part or all default values may be hard-coded in software program in client application 210 or in hardware components. Alternatively, the client application 210 may also access a file to obtain default values, or it may calculate certain default values based on the information it has obtained during previous steps or components (e.g. from an output device profile). A user may or may not have the ability to pre-configure, or change or overwrite some or all defaults. The client application 210 may obtain and use some or all defaults with or without user intervention or knowledge.
[0252] In step 1230 , the client application 210 of present invention performs rasterization operation to conform a content (e.g. a digital document), which may includes objects and information in vector graphics, text, and images, into one or more output images in accordance with the rasterization parameters obtained in previous steps. During rasterization process, text and vector graphics object or information in the content is rasterized or converted into image or bitmap form according to the given set of rasterization parameters. Image information in the content may require scaling and interpolation operations to conform the rasterization parameters. Rasterization process may further include operations such as scaling, interpolation, segmentation, image transformation, image encoding, color space transformation etc. to fit or conform the one or more output images to the given set of rasterization parameters such as target output size, resolution, bit depth, color space and image format etc.
[0253] In step 1240 , the client application 210 generates an intermediate output data that includes the rasterized one or more output images. The intermediate output data of the present invention may contain image information, instructions, descriptions, and data such as color profile among others. Creating and generating intermediate output data may further include operations such as compression, encoding, encryption, smoothing, segmentation, scaling and or color correction, among others. The image or images contained in an intermediate output data may be variously encoded and/or implemented with different image formats and/or compression methods (e.g. JPEG, BMP, TIFF, JBIG etc or combination). One preferred implementation is to generate or encode the output image in the intermediate output data with mixed raster content (MRC) description. The use of MRC in the data output process of present invention provides opportunities to improve the compression ratio by applying different compression techniques to segmented elements in the content. In addition, MRC provides opportunities to maintain more original content information during the encoding process of the output image and, therefore, potentially improve output quality.
[0254] In step 1250 , the client application 210 transmits intermediate output data to an output device 220 through local communication link 240 . The communication link may be implemented with wired or wireless technologies and the transmission may include one or multiple sessions.
[0255] It should be recognized that FIG. 12A illustrates one example of a client application process 1030 in the data output method 1002 of present invention. Other implementations with more or less steps are possible, and several additional optional processes not shown in FIG. 12 may also be included in the client application process 1030 . Use of these different variations, however, does not result in a departure from the scope of the present invention. As an example, an optional authentication step may be included when the selected output device 220 provides service to a restricted group of users. Various authentication procedures may be added in step 1210 when client application 210 obtains output device profile by communicating with an output device or an output controller. As another example, authentication procedures may also be implemented in step 1250 when the client application transmits intermediate output data to one or more output devices 220 or output controllers 230 . A simple authentication may be implemented by, for example, comparing the identity of an information apparatus 200 with an approved control list of identities stored in the output device 220 or output controller 230 . Other more complex authentication and encryption schemes may also be used. Information such as user name, password, ID number, signatures, security keys (physical or digital), biometrics, fingerprints, voice among others, may be used separately or in combination as authentication means. Such identification and or authentication information may be manually provided by user or automatically detected by the selected output device or devices 220 or output controller 230 . With successful authentication, a user may gain access to all or part of the services provided by the output device 220 . The output device profile that the client application 210 obtains may vary according to the type or quality of service requested or determined. If authentication fails, it is possible that a user may be denied partially or completely access to the service. In this case, the user may be provided with alternatives such as selecting another output device 220 or alternative services.
[0256] Another optional process is that a user may be asked to provide payment or deposit or escrow before, during or after output service such as step 1210 or 1250 with reference to FIG. 12 . Examples of payment or deposit may include cash, credit card, bankcard, charge card, smart card, electronic cash, among others. The output controller 220 may provide payment calculation or transaction processing as optional feature sets of present invention.
[0257] FIG. 12B illustrates another exemplary client application output process 1030 with which an information apparatus 200 can pervasively and universally output content to one or more output devices 220 associated with or equipped with an output controller 230 of present invention.
[0258] The process illustrated in FIG. 12B is similar to the process described in FIG. 12A except that step 1210 , obtaining output device profile, is skipped. In this embodiment, the client application 210 utilizes a set of hard-coded, standard or predefined output device parameters including rasterization parameters with which the client application 210 can perform rasterization operation and other required image processing functions. Users may be provided with the option of changing these parameters or inputting alternative parameters. Rasterization parameters include output size, output resolution, bit depth, color space, color channels, scale factors etc. These pre-defined parameters typically comply with a specification or a standard. The same specification and standard may also defined or describe at least partly the intermediate output data. Predefined standard parameters can be stored in a file or profile in an information apparatus 200 , an output controller 230 , and/or in an output device 220 for easy update or upgrade.
[0259] In client output process 1204 , since the rasterization parameters are predefined, the client application 210 may not need to upload printer profiles from the selected output device 230 . Consequently, no two-way communication between the information apparatus 200 and the output device or devices 220 is necessary in this process 1204 when compared with process 1202 illustrated in FIG. 12A . The client application 210 performs rasterization operation 1225 based on standard and/or predefined parameters and generates a rasterized output image with predefined or standard properties of those rasterization parameters. The resulting intermediate output data, which includes at least one rasterized output image, is transmitted from the information apparatus 200 to an output device 220 in step 1250 or to its associated output controller 230 for rendering or output. The intermediate output data generated in process 1202 in general is less device dependent compared to the intermediate output data generated in the process 1202 shown in FIG. 12A . The output controller 230 included or associated with the output device 220 may be preprogrammed to interpret the raster output image, which includes properties or attributes that correspond to those standard or predefined parameters.
[0260] The standard or predefined rasterization parameters may be hard coded or programmed into the client application 210 and/or the output controller 230 . However, instead of hard coding those parameters, one technique to facilitate updates or changes is to store those standard parameters in a default file or profile. The standard or predefined parameters contained in the file or profile can be retrieved and utilized by applications in an information apparatus 200 (e.g. client application 210 ) and/or by applications or components in an output device 220 or the output controller 230 . In this way, any necessary updates, upgrades or required changes to those predefined or standard parameters can be easily accomplished by replacing or modifying the file or profile instead of modifying or updating the program, application or components in the information apparatus 200 , output device 220 and/or output controller 230 .
[0261] A client application process 1204 providing universal output capability to information apparatus 200 may include or utilize:
A client application 210 that obtains content (e.g. digital document) intended for output. A client application 210 that optionally obtains user preferences (in step 1220 ) through (1) user's input (automatic or manual) or selections or (2) based on preset preference or predefined defaults or (3) combination of the above. A client application 210 that rasterizes content (in step 1230 or 1225 ) according to pre-defined or standard rasterization parameters. A client application 210 that generates intermediate output data (in step 1240 ) for rendering or output at an output device 220 ; the intermediate output data containing at least partially a rasterized image related to the content intended for output. A client application 210 that transmits the intermediate output data to an output device 220 (in step 1250 ) for further processing and final output.
[0267] One advantage of the client output process 1204 of FIG. 12B compared to the process 1202 illustrated in FIG. 12A is that the generated intermediate output data is in general less device dependent. The device independent attribute allows the intermediate output data to be more portable and acceptable to more output devices equipped or associated with output controllers. Both data output processes ( 1202 and 1204 ) enable universal output; allowing a user to install a single client application 210 or components in an information apparatus 200 to provide output capability to more than one output device 220 .
[0268] FIG. 13A illustrates one example of an output device process 1302 and its associated raster imaging method of present invention. In this output device process 1302 , an output device 220 is capable of receiving an intermediate output data from an information apparatus 200 . The output device process 1302 and its operations may include or utilize:
An output device/system or output controller that receives intermediate output data (in step 1300 ). The intermediate output data includes at least partially a raster output image describing at least part of the content for rendering at the output device 220 or system 250 . An output device/system or output controller that interprets (in step 1310 ) the intermediate output data; in one preferred embodiment, the intermediate output data includes an output image utilizing one or more MRC formats or components. An output device/system or output controller that performs image processing operation (in step 1320 ) on the raster image. The image processing operation may include but not limited to image decompression, scaling, halftoning, color matching, among others. An output device/system or output controller that converts and or generates (in step 1330 ) output-engine output data that is in a format or description suitable for input to an output engine (e.g. printer engine in case of a printer) included in an output device 220 . An output engine in an output device 220 that renders or generates a final output (e.g. the output-engine output data) in step 1370 .
[0274] The output device 220 or output system 250 may include an output controller 230 internally or externally to assist the management and operation of the output process 1302 . As shown in FIG. 7 , there are many possible configurations and implementations of an output controller 230 associated to an output device 220 Herein and after, output controller 230 is regarded as an integral part of the output device to which it is attached. Hence, the following described output device operations may be partially or completely performed by the output controller associated with it.
[0275] In step 1300 , output device process 1302 is initiated by client application 210 transmitting an intermediate output data to output device 220 or output system 250 . In step 1310 , the output device 220 reads and interprets the intermediate output data, containing at least one raster output image relating to the content intended for output. During the reading and interpretation process 1310 , the output device 220 may include components that parse the intermediate output data and perform operations such as decompression, decoding, and decryption among others. The output image may be variously encoded and may include one or more compression methods.
[0276] In the event that the method of image encoding includes MRC format, then, in one example implementation, during decoding and mapping of the output image in step 1310 , the lower resolution layer and information in an image that includes MRC may be mapped, scaled or interpolated to a higher-resolution output image to produce a better image quality. Therefore, step 1310 , in the event that the intermediate output data includes MRC component, each layer in an MRC image can be decompressed, processed, mapped and combined into a single combined output image layer. Step 1310 may also include scaling, color space transformation, and/or interpolation among others. In addition to the possibility of mapping methods using different scaling and interpolation ratio with different layers, another advantage of using MRC is that segmentation information contained in MRC can be utilized to apply different image processing and enhancement techniques to data in different layers of an MRC image in step 1320 .
[0277] In step 1320 , the output device 220 may further perform image processing operations on the decoded output image. These image processing operations may include, for example, color correction, color matching, image segmentation, image enhancement, anti-aliasing, image smoothing, digital watermarking, scaling, interpolation, and halftoning among others. The image processing operations 1320 may be combined or operated concurrently with step 1310 . For example, while each row, pixel, or portion of the image is being decoded and or decompressed, image processing operations 1320 is applied. In another implementation, the image processing 1320 may occur after the entire output image or a large portion of the image has been decoded or decompressed.
[0278] If the intermediate output data includes MRC component, then in step 1320 , there are additional opportunities to improve image quality. An image encoded in MRC contains segmented information that a traditional single layer image format does not usually have. As an example, foreground can be in one layer, and background in another. As another example, chrominance information may be in one layer and luminance may be in another. This segmented information in MRC may be used to apply different or selective image processing methods and algorithms to different layers or segments to enhance image quality or retain or recover image information. Different image processing techniques or algorithms may include color matching, color correction, black generation, halftoning, scaling, interpolation, anti-aliasing, smoothing, digital watermarking etc. For example, one can apply calorimetric color matching to foreground information and perceptual color matching to background information or vice versa. As another example, error diffusion halftoning can be applied to foreground and stochastic halftoning can be applied to background or vice versa. As yet another example, bi-cubic interpolation can be applied to a layer and bi-linear or minimum distance interpolation can be applied to a different layer.
[0279] In step 1330 , the output device 220 or the output controller 230 may convert the processed image (e.g. halftoned) into a form acceptable to the output engine of output device 220 . This conversion step is optional, depending on the type, format and input requirement of a particular output device engine (e.g. printer engine in case of a printer). Different output engines may have different input raster image input requirements. As an example different output engines may require different input image formats, number of bits or bytes per pixel, compression or uncompressed form, or different color spaces (e.g. such as RGB, CMY, CMYK, or any combination of Hi-Fi color such as green, orange, purple, red etc). Incoming raster image data can be encoded in a row, in a column, in multiple rows, in multiple columns, in a chunk, in a segment, or a combination at a time for sending the raster data to the output engine. In some cases, step 1330 may be skipped if the result of step 1320 is already in a form acceptable to the output device engine. In other cases, however, further conversion and or processing may be required to satisfy the specific input requirement of a particular output device engine.
[0280] It is important to note that the above described processing from step 1310 to step 1330 may require one or more memory buffers to temporarily store processed results. The memory buffer can store or hold a row, a column, a portion, or a chunk, of the output image in any of the steps described above. Storing and retrieving information into and from the memory buffer may be done sequentially, in an alternating fashion, or in an interlaced or interleaved fashion among other possible combinations. Step 1310 to step 1330 operations can be partially or completely implemented with the output controller 230 .
[0281] In step 1370 , the output device engine included in the output device 220 or output system 250 receives the output-engine output data generated in step 1330 or step 1320 . The output-engine output data is in a form that satisfies the input requirements and attributes of the output engine, such as color space, color channel, bit depth, output size, resolution, etc. The output engine then takes this output-engine output data and outputs or renders the data content through its marking engine or display engine.
[0282] One advantage of data output method 1002 that includes output device process 1302 is that it has less processing requirements on an information apparatus 200 compared to conventional process with reference to FIG. 1A , and therefore, enables more information apparatus 200 with relatively lower processing power and memory space to have output capability.
[0283] For example, some image processing functions, such as halftoning (e.g. error diffusion) may require substantial processing and computing power. In data output process 1002 that includes output device process 1302 , halftoning is performed in step 1320 by an output device component (e.g. the output controller 230 ) included in the output device 220 or the output system 250 , not in the information apparatus 200 ; therefore reducing the computational requirements for the information apparatus 200 . Another advantage of data output 1302 is that the intermediate output data is less device dependent than the output data generated by conventional output method 102 with reference to FIG. 1A . The device independence provides opportunity to allow a single driver or application in an information apparatus 200 to output intermediate output data to a plurality of output devices 220 that include output controllers 230 .
[0284] Some output devices 220 may contain a printer controller 410 . An example of this type of output device or printer is a PostScript printer or PCL printer among others. FIG. 13B illustrates an example of an output device process 1304 with a printer that includes a printer controller 410 . As discussed in FIG. 1 , a printer with a printer controller requires input such as page description language (e.g. PostScript, PCL etc.), markup language (HTML, XML etc), special image format, special graphics format, or a combination, depending on the type of the printer controller.
[0285] There are many printing system configurations for providing the data output capability and process to a printer or a printing system that includes a printer controller. In one example, the existing printer controller in the output device 220 may incorporate the feature sets provided by the output controller to form a “combined controller” as described previously with reference to FIGS. 7C and 7F . In another example, the output controller 230 of present invention may be connected sequentially or cascaded to an existing printer controller; the output controller 230 can be internally installed (with reference to FIG. 7B ) or externally connected (with reference to FIG. 7A ) to the output device 220 . For output device 220 that includes a printer controller, the output controller 230 may simply decode the intermediate output data in step 1310 and then convert it into a form acceptable for input to the printer controller in step 1350 .
[0286] An output device process 1304 and operations for an output device 220 or system 250 that includes a printer controller 410 may include or utilize:
An output controller 230 or components in an output device 220 or system 250 that receives an intermediate print data or output data (with reference to step 1300 ), the intermediate print data includes at least a raster image related at least in part to the content for rendering at the output device 220 . An output controller 230 or components in an output device 220 or system 250 that interprets the intermediate output data (with reference to step 1310 ); in one preferred embodiment, the intermediate output data includes an output image utilizing one or more MRC format or components. An output controller 230 or components in an output device 220 or system 250 that converts the intermediate output data into a printer-controller print data (with reference to step 1350 ); the printer-controller print data includes a format or language (e.g. PDL, PDF, HTML, XML etc.) that is acceptable or compatible to the input requirement of a printer controller. A printer controller or components in an output device 220 or system 250 that receives a printer controller print data; the printer controller may parse, interpret and further process (e.g. rasterization, scaling, image enhancement, color correction, color matching, halftoning etc.) and convert the printer-controller print data into a printer-engine print data (with reference to step 1360 ); the printer-engine print data comprising of a format or description acceptable for input to a printer engine in the output device 220 or the output system 250 . A printer engine or components in an output device 220 or system 250 that renders or generates a final output (with reference to step 1370 ) with the input printer engine print data.
[0292] In output device process 1304 , step 1300 (receiving intermediate output data) and step 1310 (interpret intermediate output data) are identical to step 1300 and step 1310 in output device process 1302 , which have been described in previous sections with reference to FIG. 13A .
[0293] In step 1350 , the output controller 230 converts the intermediate print data into a printer-controller print data that is in a form compatible or acceptable for input to a printer controller. For example, a printer controller may require as input a specific page description language (PDL) such as PostScript. The output controller 230 then creates a PostScript file and embeds the output image generated or retrieved in step 1310 into the PostScript file. The output controller 230 can also create and embed the output image from step 1310 into other printer controller print data formats, instructions or languages.
[0294] In step 1360 , the printer controller receives printer-controller print data generated in step 1350 that includes an acceptable input language or format to the printer controller. The printer controller may parse, interpret, and decode the input printer-controller print data. The printer controller may further perform raster image processing operations such as rasterization, color correction, black generation, GCR, anti-aliasing, scaling, image enhancement, and halftoning among others on the output image. The printer controller may then generate a printer-engine print data that is suitable for input to the printer engine. The type and or format of printer-engine print data may vary according to the requirement of a particular printer engine.
[0295] It is important to note that the above described process from step 1310 to step 1360 may require one or more memory buffer to temporarily store processed results. The memory buffer can store or hold a row, a column, a portion, or a chunk, of the output image in any of the steps described above. Storing and retrieving information into and from the memory buffer may be done sequentially, alternated, or in an interlaced or interleaved fashion among other possible combinations. Process and operations of step 1310 to step 1360 can be implemented with output controller 230 .
[0296] In step 1370 , the printer engine included in the output device 220 or output system 250 generates or renders the final output based on the printer-engine print data generated in step 1360 . For example, the printer-engine print data may be in CMY, CMYK, and RGB etc, and this may be in one or more bits per pixel format, satisfying the size and resolution requirement of the printer engine. The printer engine included the output device 220 may take this print data and generate or render an output page through its marking engine.
[0297] Having described and illustrated the principles of our invention with reference to an illustrated embodiment, it will be recognized that the illustrated embodiment can be modified in arrangement and detail without departing from such principles. In view of the many possible embodiments to which the principles of our invention may be applied, it should be recognized that the detailed embodiments are illustrative only and should not be taken as limiting the scope of our invention. Rather, I claim as my invention all such embodiments as may come within the scope of the following claims and equivalents thereto.
[0298] Unless the context indicates otherwise, a reference in a claim to the number of instances of an element, be it a reference to one instance or more than one instance, requires at least the stated number of instances of the element but is not intended to exclude from the scope of the claim a structure or method having more instances of that element than stated. Specifically, but without limitation, a reference in a claim to an or one output device or system, to an or one image, or to a or one rasterization parameter is not intended to exclude from the scope of the claim a structure or method having, including, employing or supplying two or more output devices or system, images or rasterization parameters. | 4y
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BACKGROUND
[0001] 1. Field of the Invention
[0002] The present invention relates to power electronics, and more particularly to a method and apparatus of a unified solution for bridgeless power factor controllers and grid connected inverters.
[0003] 2. Background Information
[0004] Conventionally, the bridgeless power factor controllers and the grid connected inverters are controlled with different approaches. In both applications, it is essential to regulate the dc voltage to a constant and to control the ac side current to be in phase with the ac side voltage. The difference in the two applications is the direction of power, in the power factor controllers, the power direction is from the ac side to the dc side. In the inverters, the power direction is from the dc side to the ac side. In grid connected inverters, the control often involves DSP or microcontrollers. Complex algorithms have been developed to control the ac current and the dc voltage. It is preferred to have a unified, easy-to-use control solution which works for both power factor controller and grid connected inverter. In this way, the development cycle for both applications can be reduced. It is also desired to have a control solution which leads to better ac current waveform, less power dissipation, and higher reliability. The disclosed invention provides a solution to all those requirements.
SUMMARY OF THE INVENTION
[0005] The embodiments of the present invention are directed to the general method and the implementation of the unified controller for both bridgeless power factor controllers and grid connected inverters. The control method involves two steps. The first step is to derive the ac side current reference from the ac side voltage and the dc side voltage. The second step is to regulate the ac side current to the current reference with minimal response time. The first step is based on the mathematical relationships between the ac side voltage, current, and the dc side voltage. It can be implemented with either hardware or software. The hardware implementation example has been provided, mainly based on the sample based controller. The software flow chart has also been provided. The second step may be implemented with all current mode full bridge controllers. In the present invention, a modified hysteretic switching pattern is disclosed. The disclosed switching pattern can minimize the switching event, avoid the usage of deadtime without the risk of shoot-through.
BRIEF DESCRIPTION OF FIGURES
[0006] FIG. 1 is the general topology of single phase voltage source converter;
[0007] FIG. 2 shows the waveforms of ac side voltage and current and dc side voltage;
[0008] FIG. 3 is the control diagram of deriving ac current reference Iacref;
[0009] FIG. 4 is the block diagram showing the hardware implementation of ‘Sample Based Controller’ block in FIG. 3 ;
[0010] FIG. 5 is the software flow chart of ‘Sampled Based Controller’ block in FIG. 3 ;
[0011] FIG. 6 is the conventional hysteretic switching pattern for single phase converters;
[0012] FIG. 7 shows the disclosed switching pattern for power flow controller during positive half cycle of the ac voltage;
[0013] FIG. 8 shows the disclosed switching pattern for power flow controller during negative half cycle of the ac voltage;
[0014] FIG. 9 shows the disclosed switching pattern for grid connected inverter during positive half cycle of the ac voltage;
[0015] FIG. 10 shows the disclosed switching pattern for grid connected inverter during negative half cycle of the ac voltage;
[0016] FIG. 11 shows an alternate disclosed switching pattern for power flow controller during positive half cycle of the ac voltage;
[0017] FIG. 12 shows an alternate disclosed switching pattern for power flow controller during negative half cycle of the ac voltage;
[0018] FIG. 13 shows an alternate disclosed switching pattern for grid connected inverter during positive half cycle of the ac voltage;
[0019] FIG. 14 shows an alternate disclosed switching pattern for grid connected inverter during negative half cycle of the ac voltage;
[0020] FIG. 15 is the block diagram of the implementation of the disclosed switching pattern;
[0021] FIG. 16 is the complete IC block diagram for general bridgeless PFC circuit and/or grid connected inverter controller
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] Both the bridgeless power factor controller and the grid connected inverter are converters connected to the power grid. FIG. 1 shows the general topology of the converter. S 1 , S 2 , S 3 , and S 4 are general power semiconductors. Without losing generosity, they are drawn as ideal switches with anti-paralleled diodes. They can be MOSFET, or IGBT, or diode, whichever applicable. The ac source Vac is the voltage source with a stable RMS voltage level and a fixed frequency. Lac 1 and Lac 2 are the interface inductors. C is the dc side bulk capacitor. The dc side voltage Vdc is to be regulated. In either power factor controller or inverter. Vdc must be regulated to a constant value. The ac side current must be a sinusoidal waveform with the same phase angle as the ac voltage. The only difference is that the current sense polarity of a power factor controller is the reverse of an inverter. In the following description, the reversal of the polarity is not explicitly emphasized. It is implied that whenever a power factor controller is mentioned, the current polarity is defined as positive if the current flows from the ac side to the dc side; and whenever an inverter is mentioned, the current polarity is defined as positive if the current flows from the dc side to the ac side.
[0023] The control of the general converter as shown in FIG. 1 includes two steps. The first step is to find out the ac side current reference, A ‘Sample Based Controller’ is disclosed as an effective and easy-to-implement controller. The second step is to find a way to let the actual ac current follow the current reference as quickly as possible, A new current mode switching pattern is disclosed to improve the waveform and reduce the losses.
First Step: Find the ac Side Current Reference—‘Sample Based Controller’
[0024] Since the ac side current has to be in phase with the ac voltage, it is straightforward to make the ac current reference to be proportional to the ac voltage. The difficult part is how to derive the proportion coefficient, which determines the magnitude of the current. The magnitude of the current determines the amount of power being delivered. So the coefficient is supposed to be derived from the power requirement. In voltage source converter, the variation in the dc side voltage (Vdc in FIG. 1 ) reflects the relationship between ac side power and dc side power.
[0025] Assume the ac side voltage being
[0000] V sc ( t )=√{square root over (2)} V rms sin(ω t ) (1)
[0000] Where Vac is the ac side voltage as shown in FIG. 1 ;
Vrms is the RMS voltage of Vac;
ω=2πf, f is the frequency of the ac side voltage; and
t is the time.
[0026] In steady state operation of the power factor controller, the current direction is from the ac side to the dc side, with the same phase angle of the ac voltage. Assume the RMS value of the current being Irms, so
[0000] I ac ( t )=√{square root over (2)} I rms sin(ω t ) (2)
[0000] Where Iac is the ac side current as shown in FIG. 1 , with the direction from the ac side to the dc side.
[0027] Assume under steady state, the dc side voltage is Vdc and dc side current is Idc, as shown in FIG. 1 . Neglect the losses in the semiconductors, the inductor, and the wiring. The following set of power balance equations can be written.
[0000]
P
a
c
(
t
)
-
t
E
l
(
t
)
=
P
d
c
(
t
)
+
t
E
c
(
t
)
(
3
)
P
a
c
(
t
)
=
V
a
c
(
t
)
I
a
c
(
t
)
(
4
)
P
d
c
=
V
d
c
(
t
)
I
d
c
(
t
)
(
5
)
E
1
(
t
)
=
1
2
(
L
a
c
1
+
L
a
c
2
)
I
a
c
2
(
t
)
(
6
)
E
c
(
t
)
=
1
2
CV
d
c
2
(
t
)
(
7
)
[0000] Where Pac(t) is the ac side instantaneous power; Pdc is the dc side power, which is a constant; El(t) is the total energy stored in the inductors Lac 1 and Lac 2 ; Ec(t) is the energy stored in the capacitor C; Lac 1 , Lac 2 , and C are the inductors and the dc side capacitor in FIG. 1 .
[0028] From Equations (1)˜(7), the dc side voltage can be derived as
[0000]
V
d
c
2
(
t
)
=
V
d
c
0
2
+
Δ
Pt
-
P
d
c
2
+
Q
l
2
ω
C
sin
(
2
ω
t
-
δ
)
(
8
)
[0000] Where: Vdc 0 is the initial value of Vdc
[0000]
Δ
P
=
V
r
m
s
I
r
m
s
-
P
d
c
Q
l
=
ω
L
I
r
m
s
2
L
=
L
a
c
1
+
L
a
c
2
tan
δ
=
Q
l
P
d
c
[0029] Equation (8) shows that
when ΔP=0, Vdc 0 is the rms value of Vdc. when ΔP=0, Vdc(t) varies periodically at double of the line frequency. when ΔP>0, Vdc(t) will ramp up when ΔP>0, Vdc(t) will ramp down In practical, Q 1 <<Pdc. So when ΔP=0, Vdc(t) reaches Vdc 0 almost at the same time when the ac side voltage reaches zero.
[0035] FIG. 2( a ) shows the waveforms of the ac side voltage and current; FIG. 2( b ), ( c ) and ( d ) show the dc side voltage waveform when ΔP=0, ΔP>0 and ΔP<0, respectively. The trend lines are drawn by connecting Vdc(t) only at the moments of ac voltage zero-crossing points.
[0036] The derivation of the ac side current reference is based on the above analysis and the results shown in FIG. 2 . The control diagram is shown in FIG. 3 . The current reference Iacref is the product of the ac side voltage and a coefficient k. The coefficient k is derived from ΔVdc, which is the difference between the dc voltage reference and the actual dc voltage. The key point is that k is updated only at the zero crossing points of the ac input voltage. The controller which derives k is called ‘Sample Based Controller’, because it updates k once every half cycle.
[0037] The ‘Sample Based Controller’ block in FIG. 3 can be implemented either in hardware or in software. FIG. 4 shows a hardware implementation example.
[0038] In FIG. 4 , the ‘Zero-crossing of Vac’ signal is from the ‘Zero-crossing Detector’ block in FIG. 3 . It is a square waveform. Both rising and falling edges indicate a zero-crossing point of the ac voltage. The ‘Signal Conditioning’ block in FIG. 4 transforms the waveform into a pulsed logic signal. The signal is normally at low level. The rising and/or falling edges of the zero-crossing signal will trigger the logic signal to be high level for a short period of time, which is enough to activate the downstream sample/hold circuit. The pulse duration is in the order of micro-seconds.
[0039] ‘Sample/Hold 1 ’ and ‘Sample/Hold 2 ’ blocks are used to get the new ΔVdc value and to keep the last ΔVdc value. It is important to have the ‘Delay 1 ’ block, so that the last ΔVdc value can be reliably sampled through ‘Sample/Hold 2 ’ block, to become ‘ΔVdc,old’ signal. So the timing of ‘Delay 1 ’ block should be designed to make sure that the starting of the sample period of ‘Sample/Hold 1 ’ is after the completion of the sample period of ‘Sample/Hold 2 ’.
[0040] K P , K D and K I are gain blocks. This gives the options of using any one or any combinations of P, I, or D controller. ‘ΔVde,new’ is the present difference between the dc voltage reference and the actual dc voltage. This signal, is fed to gain block K P directly for proportional controller output. The summing block ‘SUM 1 ’ takes ‘ΔVdc,new’ and ‘ΔVdc.old’ as inputs, with ‘Δdc,new’ being positive, and ‘ΔVdc,old’ being negative. The result is fed to gain block K D for differential controller output. It is important to have delay block ‘Delay 2 ’ and sample/hold block ‘Sample/Hold 3 ’ for a functional integrator. ‘Sample/Hold 3 ’ is used as a memory of the integration result from the last time. The zero-crossing signal will trigger ‘Sample/Hold 3 ’ block to feed the old integration value to one input of the summing block ‘SUM 2 ’. The other input of ‘SUM 2 ’ block is ‘ΔVdc,new’, so the output of ‘SUM 2 ’ is the new integration result. The ‘Delay 2 ’ block is important to prevent the output, of ‘Sample/Hold 3 ’ block from changing. The timing of the delay block is a little longer than the completion of sample period of ‘Sample/Bold 3 ’ block. In this way, the output of ‘Delay 2 ’ block will remain unchanged for the rest of the half cycle, until the next zero-crossing of the ac voltage. Finally, the output is the coefficient k, which is the sum of P, I and D controllers. Since the output is updated once every half cycle, it is actually a discrete PID controller with sample time being half of the line cycle.
[0041] In FIGS. 3 and 4 , all functional blocks are simple analog circuits. FIGS. 3 and 4 form the block diagram of a complete integrated circuit. The circuit can greatly reduce the development cycle of the system, improve the reliability, and lower the system cost.
[0042] The ‘Sample Based Controller’ block in FIG. 3 can also be implemented in software. FIG. 5 shows a software flowchart example.
[0043] In the initialization part, the gain values of K P , K D and K I are given. All the inputs and outputs are cleared to 0. There should be software limits for the integrator output I and the overall output k. Set both edges of zero-crossing signal to be interruptable. Once a zero-crossing event happens, the interrupt part of the software is executed. In the interrupt software, the outputs of P, I and D controllers are calculated separately and then added up together to get the overall output k. With this method, only a low profile microcontroller is required, due to the low memory requirement, short execution time, and low interrupt frequency.
Second Step: A New Current Mode Switching Pattern
[0044] The basis of the new switching pattern is the hysteretic control, in the conventional hysteretic switching pattern, the switches are controlled in pairs. FIG. 5 shows the current flow of an inverter during positive half cycle of the ac voltage. Refer to FIG. 1 , S 1 and S 4 are always switched on and off at the same time; S 2 and S 3 are switched on and off at the same time. Whenever S 1 and S 4 are on, S 2 and S 3 must be off and vice versa. The logic is simple. However, there are two main disadvantages in this pattern. Firstly, a deadtime has to be inserted during the commutation between S 1 and S 2 , and also between S 3 and S 4 , to avoid the risk of shoot-through. Secondly, all the switches are commutated once in each switching cycle, which is not necessary and increases the losses.
[0045] The idea of the disclosed switching pattern is to reduce the number of switching events. In each half line cycle, only one switch is in PWM mode for both PFC circuit and the inverter.
[0046] The current flow for positive and negative half cycles of one switching pattern example for bridgeless PFC is shown in FIG. 7 and FIG. 8 , respectively. For a bridgeless PFC circuit, there are two diode and two controllable switches. In the positive half cycle, S 2 is in PWM mode and S 4 is kept off. In the negative half cycle, S 2 is kept off and S 4 is in PWM mode. Let a logical variable H represent the sign of the ac side voltage, i.e.,
[0000] H=0 when the ac side voltage Vac<0;
H=1 when the ac side voltage Vac>=0.
[0047] Define a hysteretic band ΔI (ΔI>0). Let a logical variable S represent the relationship between the actual current and the current reference as follows:
[0000] S=0 when Iac>Iacref+ΔI
S= 1 when Iac<Iacref−ΔI
S is not changed when Iac is between (Iacref−ΔI) and (Iacref+ΔI). According to FIG. 7 and FIG. 8 , the switching logic equations of the switches can be written as;
[0000] S 2 = H·S (9)
[0000] S 4 = H · S (10)
[0000] Where H and S are the logic inverse of H and S, respectively.
[0048] The current flow for positive and negative half cycles of one switching pattern example for the inverter is shown in FIG. 9 and FIG. 10 , respectively. For an inverter, there has to be four controllable switches. Note FIGS. 9 and 10 have the same current path as in FIGS. 7 and 8 , except; the reversal in the direction. In the positive half cycle, S 1 is in PWM mode, S 2 and S 3 are kept off, and S 4 is kept on. In the negative half cycle, S 1 is kept off, S 2 is kept on, S 3 is in PWM mode, and S 4 is kept off. The switching logic equations are:
[0000] S 1 = H·S (11)
[0000] S 2 = H (12)
[0000] S 3 = H · S (13)
[0000] S 4 =H (14)
[0049] This method can be recombined to get up to four different switching patterns, due to the symmetric nature of the converter. Another example is shown in FIG. 11˜14 for another kind of current flow. For the power factor controller, instead of using S 1 and S 3 to be diodes, in this example, S 1 and S 2 are diode. For the inverter, instead of doing PWM on S 1 and S 3 , in this example, S 3 and S 4 are in PWM mode. The resulting switching logic equations for the power factor controller are:
[0000] S 3 = H·S (15)
[0000] S 4 = H · S (16)
[0050] The resulting switching logic equations for the inverter are;
[0000] S 1 =H (17)
[0000] S 2 = H (18)
[0000] S 3 = H · S (19)
[0000] S 4 = H·S (20)
[0051] Other combinations in power factor controllers include choosing S 3 and S 4 as diodes, or S 2 and S 4 as diodes.
[0052] When S 3 and S 4 are diodes in power factor controllers, the switching logic equations are:
[0000] S 1 = H · S (21)
[0000] S 2 = H·S (22)
[0053] The corresponding switching logic equations for the inverter with the same current path are:
[0000] S 1 = H·S (23)
[0000] S 2 = H · S (24)
[0000] S 3 = H (25)
[0000] S 4 =H (26)
[0054] When S 2 and S 4 are diodes in power factor controllers, the switching logic equations are:
[0000] S 1 = H · S (27)
[0000] S 3 = H·S (28)
[0055] The corresponding switching logic equations for the inverter with the same current path are:
[0000] S 1 =H (29)
[0000] S 2 = H · S (30)
[0000] S 3 = H (31)
[0000] S 4 = H·S (32)
[0056] The switching pattern is based on hysteresis comparison and simple logics, so it can be integrated into one integrated circuit. One implementation example is shown in FIG. 15 . The inputs to the circuit include the ac side voltage Vac, the ac current reference Iacref which is derived from the first step, the measured ac current Iac, and the optional external setting ‘Hysteresis Band Setting’. The outputs are the switching signals. Since there are so many combinations, the outputs are designed to be suitable for ail combinations. For power factor controllers, the output ‘H’ and ‘ H ’ are not used.
[0057] Under this kind of switching pattern, for the bridgeless power factor controller, each controllable switch is in PWM mode for half cycle and in fully on mode for the other half cycle. For the grid connected inverter, one pair of the switches are switched at line frequency only. The other pair of the switches are in PWM mode for half cycle and in off mode for the other half cycle. All unnecessary switching events have been removed. This feature reduces the gate drive loss, which is a considerable reduction in the control power dissipation. There is no risk of shoot-through, so no deadtime is required. This is an important benefit, it not only improves the waveform by removing the distortion caused by the deadtime, but also improves the reliability.
[0058] Finally, the two steps can be combined into one integrated circuit, as shown in FIG. 16 . FIG. 16( a ) shows the top level block, diagram which is a combination of FIG. 3 and FIG. 15 . FIG. 16( b ) shows the detail implementation of the ‘Sample Based Controller’ block, which is the same as in FIG. 4 .
[0059] While exemplary embodiments described hereinabove, it should be recognized that these embodiments are provided for illustration and are not intended to be limitative. Any modifications and variations, which do not depart from the spirit and scope of the invention, are intended to be covered herein. | 4y
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BACKGROUND
Technology for manufacturing large-area photovoltaic cells from amorphous semiconductor alloys has been developed in recent years. Breakthroughs have been made in preparing amorphous semiconductor materials of electronic device quality. These high quality materials include hydrogen, fluorine, or a combination of the two in amorphous silicon, silicon-germanium, and germanium. It is believed that hydrogen and fluorine passivate or satisfy dangling bonds and other structural defects in the amorphous structure so that desirable charge carrier transport properties are achieved.
The principal method of preparing these amorphous semiconductor materials is glow discharge deposition. In that process, a gas mixture containing at least one semiconductor precursor gas, such as silane, disilane, silicon tetrafluoride, germane, and germanium tetrafluoride or mixtures of them, is admitted to a vacuum chamber held at a reduced pressure, typically 13 to 65 pascal. The gas mixture may also include hydrogen or argon as a diluent and a dopant precursor gas, such as diborne or boron trifluoride to deposit a p-type conductivity material or phosphine or phosphorus tetrafluroide to deposit an n-type conductivity material. The gas mixture also includes a source of hydrogen and/or fluorine. Material deposited without the presence of a dopant precursor gas is typically slightly n-type in conductivity, is substantially intrinsic and may be compensated to a higher resistivity with a trace of a p-type dopant, such as boron.
The gas mixture is admitted to the chamber through a fixture that forms a cathode. A glow discharge plasma is struck between the cathode and an electrically conductive substrate by impressing an electrical potential across the cathode and substrate. The glow discharge plasma is sustained by electrical power that may be direct current or may be alternating current up through the microwave frequency range. The glow discharge disassociates the gas mixture into various species that deposit on the substrate and build up the depositing alloy. By changing dopant precursor gases during the deposition process, p-n, p-i-n, and more complex device structures may be deposited. Three layer p-i-n and multiple p-i-n amorphous silicon alloy and amorphous silicon-germanium alloy structures have proven particularly useful as photovoltaic devices.
The process of producing glow discharge deposited amorphous photovoltaic devices has been developed to permit continuous production of such materials over large areas. For example, methods for the continuous production of amorphous photovoltaic material on large-area, flexible metallic substrates has ben disclosed in U.S. Pat. Nos. 4,400,409 to Izu et al. for Method of Making P-Doped Silicon Films; No. 4,410,558 and No. 4,519,339 to Izu et al. for Continuous Amorphous Solar Cell Production System; No. 4,485,125 to Izu et al. for Method for Continuously Producing Tandem Amorphous Photovoltaic Cells; No. 4,492,181 to H. Ovshinsky et al. for Method for Continuously Producing Tandem Amorphous Photovoltaic Cells; and No. 4,514,437 to Nath for Apparatus for Plasma Assisted Evaporation of Thin Films and Corresponding Methods of Deposition. The disclosures of these patents are incorporated herein by reference. Apparatus for depositing complex amorphous semiconductor alloy devices on flexible substrates 30 cm. wide and over 300 m. long has been built and is now operating.
More recently very lightweight amorphous semiconductor alloy arrays of photovoltaic cells have been constructed from continuously deposited alloy materials. These lightweight cells have an exceptionally high specific power, i.e. power output to mass ratio. The lightweight cells are prepared in the way described above, but on a very thin substrate, such as electroformed metal foil, or a metal substrate that is chemically etched to an unconventional thinness, or on an insulator intially supported by a metal substrate that is completely removed by chemical etching after deposition of the amorphous alloy. See U.S. patent application Ser. No. 696,390 filed Jan. 30, 1985, by Hanak for Extremely Lightweight, Flexible Semiconductor Device Arrays and Method of Making Same. It is desirable to fabricate these extremely lightweight arrays directly from continuous processing machinery rather than to thin or remove a conventional thickness substrate in order to reduce the number of process steps and thereby to improve yield and to reduce cost. It is also desirable to avoid use of a very thin electroformed foil because of the special care required in handling that delicate foil.
SUMMARY OF THE INVENTION
In the invention, extremely lightweight, large-area arrays of amorphous semiconductor alloy solar cells are continuously fabricated by depositing an alloy film on a surrogate substrate, laminating a support material to the film opposite the surrogate substrate and separating the film and support material from the substrate by exposing them to a thermal shock. In a preferred embodiment of the invention, the surrogate substrate is an endless band that cycles through a deposition apparatus. The alloy film is deposited, preferably by glow discharge, to form a preselected photovoltaic structure, the support material is applied and the film is then peeled from the surrogate substrate. The substrate is then cleaned, for example, in an etching glow discharge, and cycled back into the deposition chambers for receiving an alloy film deposit. The deposition, lamination, peeling and cleaning processes all preferably proceed continuously.
The surrogate substrate is chosen to have a thermal coefficient of expansion different from that of the allow film to aid their separation. A thermal shock may be applied by passing the film and surrogate substrate through a path of an inert low temperature fluid, such as liquid nitrogen or by passing the film and substrate between rollers, one of which is heated or cooled. For a silicon alloy photovoltaic film, it is preferred to form the surrogate substrate from stainless steel.
Other processing steps may be used to form electrical contacts on the lightweight array, to laminate additional protective layers to the alloy film and to eliminate any electrical defects that may result from separating the alloy film from the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic, cross sectional view of an embodiment of an apparatus according to the invention for carrying out the inventive process.
FIG. 2 is a schematic, cross sectional view of an apparatus for applying a thermal shock according to an embodiment of the invention.
FIG. 3 is a schematic, cross sectional view of another apparatus for applying a thermal shock according to another embodiment of the invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
An embodiment of a novel apparatus 10 for carrying out the inventive process is shown in a schematic, cross sectional view in FIG. 1. In general, apparatus 10 includes a large vacuum envelope 12 in which a subatmospheric pressure may be established and maintained by vacuum pumps (not shown). Within envelope 12 there are various chambers, some communicating with others, in which the ambient gases and pressures may be independently controlled.
Within envelope 12 an endless surrogate substrate 14, preferably of stainless steel or some other material that has a thermal coefficient of expansion substantially different from that of amorphous semiconductor alloys, is trained around four rollers 16, 18, 20, and 22. These rollers are driven by a motor (not shown) to move the endless substrate through envelope 12. Additional tensioning and steering rollers may be used to keep surrogate substrate 14 taut and to maintain its sideways alignment during travel, respectively.
Substrate 14 is treated in various ways within envelope 12 and the following description is merely illustrative of one possible sequence of treatments. Some of the described treatments can be omitted, others added and some of those shown can be performed multiple times. As moving substrate 14 travels away from roller 16 toward roller 18, it enters a chamber 24 through a gas gate 26. Gas gate 26 is supplied with an inert gas that sweeps across and through the opening of chamber 24 to isolate its environment from that of envelope 12. Examples of such gas gates are described in U.S. Pat. Nos. 4,438,724 to Doehler et al. for Grooved Gas Gate; No. 4,450,786 to Doehler et al. for Grooved Gas gate; No. 4,462,332 to Nath et al. for Magnetic Gas Gate; No. 4,480,585 to Gattuso for External Isolation Moduel; and No. 4,537,795 to Nath et al. for Method for Introducing Sweep Gases Into a Glow Discharge Deposition Apparatus. The disclosures of these patents are incorporated herein by reference.
Within chamber 24 a metal or metal alloy film is deposited on substrate 14 to form an electrode, called a back electrode because of its location at the rear of the photovoltaic cells to be formed, for electrical interconnection of the photovoltaic cells to be produced. The back electrode may also be reflective to reflect back into the cell for absorption light that reaches the bottom of the cell. The back electrode may be deposited by sputtering, as illustrated by a sputtering source 28 disposed within chamber 24. Other processes, such as radio frequency sputtering or a vapor deposition, can be used to deposit the back electrode.
After the deposition of the conducting layer for the back electrode, substrate 14 moves out of chamber 24, through another gas gate 30 into an adjacent chamber 32. While chambers 24 and 32 are shown as adjacent, they may be separated within envelope 12 and an exit gas gate may be fitted to chamber 24 and an entrance gas gate fitted to chamber 32. For simplicity, however, the chambers are shown adjacent in FIG. 1 with a single gas gate between them. Likewise, other chambers within envelope 12 are shown as adjacent, but it is understood they may be separated and two gas gates may be required where only one is shown in FIG. 1.
Chamber 32 is the first of three related chambers, 32, 34, and 36. In each of these chambers, a layer of an amorphous semiconductor alloy film is deposited by establishing and maintaining a glow discharge in a gas mixture containing at least one semiconductor precursor gas. A combination cathode and gas dispenser 38 is shown disposed in each of chambers 32, 34, and 36. Examples of such cathodes are described in U.S. Pat. Nos. 4,369,730 to Izu et al. for Cathode for Generating a Plasma; and No. 4,483,883 and No. 4,513,684 both to Nath et al. for Upstream Cathode Assembly, the disclosures of which are incorporated herein by reference. Each cathode is driven by an electrical energy source (not shown) supplying direct current or alternating current at a frequency through the microwave range. Substrate 14 is electrically connected to the electrical energy source so that a glow discharge may be established and maintained in each of chambers 32, 34, and 36 between substrate 14 and the respective cathodes 38.
Chambers 32, 34, and 36 are interconnected by gas gates 40 and 42, respectively, so that their respective gas mixtures are isolated from each other. Those gas mixtures are supplied to cathodes 38 as indicated by the arrows. As is known in the art, the gas mixtures contain not only at least one semiconductor precursor gas, such as silane, disilane, silicon tetrafluoride, germane, germanium tetrafluoride and mixtures of these gases, but also a source of hydrogen and/or fluorine to passivate defects in the deposited amorphous semiconductor alloy. In addition, a diluent gas such as argon or hydrogen may be supplied. The apparatus shown is specifically intended to deposit a p-i-n or n-i-p structure. That is, a dopant precursor gas, such as diborane or boron trifluoride is added to the gas mixture in chamber 32 or 36 to deposit a p-type conductivity layer. Another dopant precursor gas, such as phosphine phorosphorus pentachloride, is added to the gas mixture in the other of chambers 32 or 36 to deposit a n-type layer. Either dopant precursor gas or only trace amounts of a p-type dopant precursor gas are added to the gas mixture in chamber 34 to deposit a substantially intrinsic type layer in that chamber. Thus a p-i-n or n-i-p structure is formed. If a simpler structure is desired, one or more chambers can be removed. If a more complex structure, such as a tandem or two cell structure, is desired, additional deposition chambers can be added to apparatus 10.
Upon completion of the deposition of the three layer amorphous semiconductor alloy film on substrate 14 (or on the back electrode), substrate 14 exits chamber 36 through a gas gate 44 and enters chamber 46. If desired, the deposited film can be formed into patterns of cells in chamber 46. A laser scriber 48 is disposed in chamber 46. Scriber 48 can form a desired pattern of cells in the alloy film by scanning its relatively high powered beam across the film in a preselected pattern, removing the film where the beam strikes. Such scribers are disclosed in U.S. Pat. No. 4,292,092 to Hanak, which is incorporated herein by reference.
After the treatment in chamber 46, if any, the combined alloy film and substrate move through a gas gate 50 into another deposition chamber 52. In chamber 52 a transparent, electrically conductive layer, such as a transparent oxide like indium tin oxide, tin oxide, or cadmium tin oxide, is deposited on the alloy film. This conductive layer forms another electrode, commonly called the front electrode because of its position on the light-incident side of the photovoltaic cell, on the array of lightweight photovoltaic cells being fabricated. The deposition process for the transparent, electrically conductive layer may be chosen from numerous known processes such as magnetron sputtering and evaporation. A sputtering source 54 is shown disposed in chamber 52 to carry out one embodiment of that process.
In a final, optional processing step, the alloy film with its conducting layer moves out of chamber 52 into an adjacent chamber 56 through a gas gate 58. In chamber 56, the transparent conducting layer is formed into patterns of interconnections by a scanning laser scriber 60 disposed in the chamber. Laser 60 works in a fashion similar to that of laser scriber 48, selectively removing the transparent conducting material wherever its beam strikes to leave a preselected pattern of conductors interconnecting the photovoltaic cells.
After any patterning of the transparent conducting layer, the cells are electrically complete and ready to be peeled away from substrate 14. However, the alloy film, back reflector and front electrode layer are no more than 1.0 micrometer in thickness and are frequently thinner. These thin films are too delicate for direct handling, so a support material is bonded to the front electrode to add mechanical strength before further processing. The substrate and deposited layers exit from chamber 56 through a final gas gate 62 to a laminating station. There, a laminate, which must be transparent if the alloy film is to be used for photovoltaic applications, is applied to the film or front electrode on the face opposite substrate 14. Ethylene vinyl acetate is one such support material. The support material is fed from a supply coil 64 to a pair of rollers 66 through which the substrate and film pass. Rollers 66 are preferably moderately heated to bond the support material to the alloy film and apply the minimum possible pressure in order to avoid damage to the film. Alternatively, the support material may be coated with a pressure sensitive adhesive for bonding to the alloy film. The structure thus produced has sufficient strength to withstand further handling and is therefore ready to be separated from substrate 14.
The substrate, alloy film, and support material next pass to a separating station 68 where they are exposed to a differential thermal shock. Because the thermal coefficients of expansion of the substrate and the alloy film and support material are different, the thermal shock causes them to separate from each other. Substrate 14 then continues around roller 18 to be cleaned and used again in the continuous processing. The alloy film with its support layer continues on for further separate processing as explained below.
Various means may be used to apply a thermal shock to the substrate-alloy film combination at station 68. Preferred embodiments of thermal shock means are shown in FIGS. 2 and 3. In FIG. 2, the assembly passes through a cooled fluid bath that results in the desired separation. In that embodiment, the assembly passes over rollers 102, 104, 106, and 108 that direct the assembly into a liquid bath 110 within a chamber 112. Bath 110 may be liquid nitrogen that is periodically replenished through an inlet 114. The use of a volatile liquid as the bath requires that station 68 be fitted with entrance and exit seals 116 and 118 that contain the fluid within chamber 112 and isolate it from the volume outside chamber 112, but inside vacuum envelope 12. Alternatively, it might be desirable to place chamber 112 outside envelope 12.
Another embodiment of a thermal shock means is shown in FIG. 3. There, a pair of oppositely disposed rollers 202 and 204 contact the substrate and alloy film, respectively. Roller 202 contacts surrogate substrate 14 and contains a liquid 206, either a relatively cold liquid, such as liquid nitrogen, or a relatively hot liquid. The heat transfer between roller 202 and substrate 14 provides a thermal shock that separates the substrate from the alloy film. This embodiment is superior to that of FIG. 2 in that no additional seals are required to isolate the processing step. Rather, the rolls may extend beyond envelope 12 or the interior of roller 202 may be accessible from outside envelope 12 to permit continuous circulation of the liquid through roller 202 to maintain a desired temperature.
After surrogate substrate 14 is separated from the alloy film, it passes over rollers 18 and 20 on its route to roller 16 for continued use. Because the separation of the alloy film from substrate 14 may not be perfect, some residue may be left on the substrate. It is desirable to remove any residue in order to maintain a high quality of continuously deposited alloy film. Substrate 14 therefore travels from roller 20 through a cleaning station 70. Station 70 includes entrance an exit gas gates 72 and 74 for isolating the gases within cleaning chamber 76 from envelope 12. A cathode 78, much like the glow discharge cathodes 38 used in chambers 32, 34, and 36, is disposed in cleaning chamber 76. By admitting an appropriate gas mixture to chamber 76, establishing appropriate process conditions, and igniting a glow discharge between substrate 14 and cathode 78, an etching process, rather than a depositing process, may be carried out. The etching cleans substrate 14 and prepares it for receiving further deposits. After cleaning, substrate 14 passes over roller 22 and back to roller 16.
After the alloy film and support material are separated from substrate 14, there may be further processing. When the alloy film is stripped from substrate 14, the back electrode, if one was deposited, is accessible. That back electrode may be formed into a pattern of electrical interconnections with a laser scriber in the same manner as the alloy film and transparent conductive layer were patterned. A laser 80 is disposed in envelope 12 adjacent the exposed back electrode to scan over a preselected pattern, removing portions of the conductive layer where it strikes and leaving behind the desired electrical interconnections. Laser 80 is shown within envelope 12, but may be contained within a chamber to contain and collect the debris produced in the laser scribing process.
After the back electrode is patterned, additional metallization may be applied to complete electrical connections to the "substrate" side of the photovoltaic array. These contacts may be predeposited on a roll of a material that is applied to the alloy film in registration with the pattern produced by laser 80 or may be a continuous, skeletal web of contacts wound on a roll that is applied to the film in registration with the patterned back contact. A coil 82 of such a film or skeletel web is disposed near the separated alloy film and is bonded to the patterned back electrode between a pair of rollers 84 disposed on opposite sides of the film. The bonding may be thermally assisted.
Finally, a support material may be applied to the backside of the photovoltaic array for added strength and protection, without substantial addition of weight. A supply roll 86 of a lightweight polymeric film such as ethylene vinyl acetate, a fluoropolymer, an acrylic, or a polyimide is applied to the alloy film between two rollers 88 disposed on opposite sides of the alloy. The polymeric film may be themally bonded to the alloy film or a pressure sensitive adhesive may be used.
The completed lightweight, large-area array of photovoltaic cells is then collected and stored on a take-up coil 90. A steering and tensioning roller 92 between rollers 88 and take-up coil 90 maintains the proper tension on the alloy film and maintains it in the appropriate side-to-side position.
The alloy film separates relatively easily from a substrate, like surrogate substrate 14. The process, however, may damage the alloy film or its electrical interconnections. When a liquid nitrogen thermal shock is applied to an alloy film on a substrate, the separation readily occurs, although some pin holes are created in the amorphous semiconductor alloy film resulting in short circuiting of some of the photovoltaic cells. The effects of these short circuits may be eliminated in numerous ways. An electrically insulating fluid that fills the pin holes, such as a cureable photoresist, may be applied to the back electrode side of the array and cured. Alternatively, an etchant that selectively etches the transparent conductive layer may be applied to the back electrode side of the array. The etchant isolates the short circuited cells and improves the performance of the array by removing the effects of the inoperative cells.
While FIG. 1 is described with respect to a particular sequence of processing, the processing steps may be performed in a different sequence or some steps may be deleted and others added. For example, it may be desirable to deposit the alloy film directly on surrogate substrate 14 by omitting the deposition of the back electrode until other processing is complete. In that case, all processing after the separation of surrogate substrate 14 from the alloy film would be omitted from apparatus 10 and would be performed in different apparatus. The alloy film and transparent conductive layer on the front side of the array might not be formed into patterns in apparatus 10 to avoid creating the debris produced in both processes. Again, in that processing sequence, no further processing steps would be performed in apparatus 10 after the separation of the alloy film from the surrogate substrate. Rather, the alloy film could be formed into patterns by water jet or laser scribing or by chemical or electrochemical etching from the back side of the alloy film. After this processing, electrical contacts would be applied to the back side of the alloy film and finally a laminate applied to the back side to protect and strengthen the assembly.
While the apparatus of FIG. 1 shows surrogate substrate 14 as an endless band, continuous processing could also be achieved with a very long, e.g. 300 m., surrogate substrate. Roller 22 would be replaced by a supply coil of substrate material and roller 20 would be replaced by a take-up reel, collecting the surrogate substrate after the alloy film has been deposited and separated from it. The cleaning step could be omitted and the substrate would be cleaned in a separate apparatus between depositions.
The invention has been described with respect to certain preferred embodiments. Various modifications and additions within the spirit of the invention will occur to those of skill in the art. Therefore, the scope of the invention is limited solely by the following claims. | 4y
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RELATED APPLICATION
This application claims the benefit of and priority to U.S. Provisional Patent Application No. 61/831,865, filed Jun. 6, 2013, the entire disclosure of which is hereby incorporated herein by reference.
TECHNICAL FIELD
In various embodiments, the present invention relates to the metallization of electronic devices such as flat panel displays and touch panel displays, in particular to capping and barrier layers for such metallization.
BACKGROUND
Flat panel displays have rapidly become ubiquitous in various markets, and are now commonly utilized in a variety of appliances, televisions, computers, cellular phones, and other electronic devices. One example of a commonly used flat panel display is the thin film transistor (TFT) liquid crystal display (LCD), or TFT-LCD. A typical TFT-LCD contains an array of TFTs each controlling the emission of light from a pixel or sub-pixel of an LCD. FIG. 1A depicts the cross-section of a conventional TFT 100 as might be found in a TFT-LCD. As shown, the TFT 100 includes a gate electrode 105 formed on a glass substrate 110 . A gate insulator 115 electrically insulates the gate electrode 105 from overlying conductive structures. An active layer 120 , typically composed of amorphous silicon, conducts charge between a source electrode 125 and a drain electrode 130 , under the electrical control of gate electrode 105 , and the conducted charge controls the operation of the pixel or sub-pixel connected thereto (not shown). A source/drain insulator 132 electrically isolates the source electrode 125 from the drain electrode 130 and protectively seals the TFT 100 . As shown, each of the gate electrode 105 , source electrode 125 , and drain electrode 130 typically include a barrier metal layer 135 and a metal conductor layer 140 thereover. The barrier 135 provides good adhesion between the conductor 140 and the underlying glass and/or silicon and reduces or prevents diffusion therebetween.
Over time, LCD panel sizes have increased and TFT-based pixel sizes have decreased, placing increasingly high demands on the conductors within the TFT-LCD structure. In order to decrease the resistance in the conductors and thereby increase electrical signal propagation speeds in the TFT-LCD, manufacturers are now utilizing low-resistivity metals such as copper (Cu) for the conductors 140 within the display. Metals such as molybdenum (Mo), titanium (Ti), or molybdenum-titanium alloys (Mo—Ti) have been utilized for barriers 135 underlying Cu conductors 140 ; however, these metals suffer from one or more deficiencies that limit the performance of the TFT-LCD and/or present difficulties in the fabrication process for the TFT-LCD. For example, some conventional barriers 135 have relatively high resistivity and therefore compromise the overall conductivity of the electrodes. Furthermore, as shown in FIG. 1B , during the etching of electrodes such as gate electrodes 105 , either a residue 145 (of one or both electrode materials) or etch discontinuities 150 , e.g., stepped or nonlinear profiles (caused by non-uniform etch rates of the two different electrode materials), may result.
Similarly, touch-panel displays are becoming more common in electronic devices, and they may even be utilized in tandem with TFT-LCDs. A typical touch-panel display includes an array of sensors arranged in rows and columns and that sense a touch (or close proximity) of, e.g., a finger, via capacitive coupling. FIG. 2A schematically depicts an exemplary sensor array 200 for a touch-panel display that includes multiple conductive column sensors 210 that are interconnected to form columns 220 , as well as multiple conductive row sensors 230 that are interconnected to form rows 240 . The sensors 210 , 230 are formed over a substrate 250 and are electrically coupled to a processor 260 that both senses the changes in capacitive coupling that represent “touches” and provides these signals to other electronic components within a device (e.g., a computer or mobile computing device that incorporates a touch screen). The sensors 210 , 230 may be formed of a transparent conductor such as indium tin oxide (ITO), and the substrate 250 may be glass or any other suitably rigid (and/or transparent) support material.
FIG. 2B depicts a magnified perspective view of a point within the sensor array 200 where the interconnected column sensors 210 intersect the interconnected row sensors 230 . In order to avoid electrical shorting between the columns 220 and the rows 240 (see FIG. 2A ), the interconnections between column sensors 210 are isolated from the underlying or overlying row sensors 230 . For example, as shown in FIG. 2B , an insulator layer 270 is disposed between the column 220 of column sensors 210 and a conductive interconnect (or “bridge”) 280 that electrically connects the row sensors 230 within a row 240 . As shown in FIG. 2C , the interconnects 280 are typically composed of an Al conductive layer 290 with an overlying barrier or capping layer 295 that is typically composed of Mo, Ti, or Mo—Ti. The capping layer 295 helps to prevent diffusion from the conductive layers 290 and protects conductive layers 290 from corrosion during processing and product use. The capping layer 295 may also improve adhesion to overlying layers. However, as described above for TFT-LCDs, the metals conventionally used for the capping layer 295 metals from one or more deficiencies that limit performance and/or present difficulties in the fabrication process. For example, the capping layers 295 may have relatively high resistivity and therefore compromise the overall conductivity of the interconnects 280 , degrading electrical performance. Furthermore, as shown in FIG. 2D , during the etching of the interconnects 280 , either a residue 296 (of one or both of conductive layer 290 or capping layer 295 ) or etch discontinuities 297 , e.g., stepped or nonlinear profiles (caused by non-uniform etch rates of the two different materials), may result.
In view of the foregoing, there is a need for barrier and/or capping metal layers for electronic devices such as TFT-LCDs and touch-panel displays that provide excellent adhesion to underlying substrates, prevent diffusion of the conductor metal into nearby layers, protect the conductor metal from corrosion, and are uniformly etched with the underlying or overlying conductor metals during fabrication.
SUMMARY
In accordance with various embodiments of the present invention, electronic devices such as TFT-LCDs and touch-panel displays, and the metallic interconnects and electrodes therein, are fabricated utilizing capping and/or barrier layers including or consisting essentially of an alloy of Cu and one or more refractory metal elements such as tantalum (Ta), niobium (Nb), Mo, tungsten (W), zirconium (Zr), hafnium (Hf), rhenium (Re), osmium (Os), ruthenium (Ru), rhodium (Rh), Ti, vanadium (V), chromium (Cr), or nickel (Ni). The one or more refractory elements may be present in the alloy at weight concentrations of 1-50 percent. In an exemplary implementation, alloy barrier layers are formed directly on substrate layers such as glass and/or silicon-based layers, and conductor layers including or consisting essentially of highly conductive metals such as Cu, silver (Ag), aluminum (Al), or gold (Au) are formed thereover to form the various electrodes in a TFT structure. In another exemplary implementation, highly conductive metals such as Cu, Ag, Al, and/or Au are utilized as conductive interconnects in a touch-panel display and are capped with protecting capping layers that include or consist essentially of an alloy of Cu and one or more refractory metal elements such as Ta, Nb, Mo, W, Zr, Hf, Re, Os, Ru, Rh, Ti, V, Cr, or Ni. The one or more refractory elements may be present in the alloy at weight concentrations of 1-50 percent (hereafter weight %).
Surprisingly, even though the barrier and capping layers are predominantly Cu, the presence of the refractory-metal alloying element(s) discourages or even prevents the diffusion of Cu into nearby layers, e.g., an underlying silicon layer, approximately as well as pure Mo barrier layers when utilized with Cu conductor layers. While not wishing to be bound by any particular theory or mechanism for this phenomenon, the refractory-metal alloying element may react with atoms of the silicon layer to form silicide regions that occupy grain boundaries in the barrier or capping metal and thereby prevent diffusion of Cu into the substrate (or other adjoining layer) along the grain boundaries, which would otherwise be fast diffusion paths.
In various embodiments, the barrier and/or capping layer includes or consists essentially of an alloy of Cu with (i) Ta and Cr, (ii) Ta and Ti, or (iii) Nb and Cr. For example, the barrier and/or capping layer may include (i) 1 weight %-12 weight % Ta (preferably approximately 5 weight % Ta) and 1 weight %-5 weight % Cr (preferably approximately 2 weight % Cr), (ii) 1 weight %-12 weight % Ta (preferably approximately 5 weight % Ta) and 1 weight %-5 weight % Ti (preferably approximately 2 weight % Ti), or (iii) 1 weight %-10 weight % Nb (preferably approximately 5 weight % Nb) and 1 weight %-5 weight % Cr (preferably approximately 2 weight % Cr). Furthermore, when utilized in conjunction with highly conductive conductor layers such as Cu to form electrodes and/or interconnects, the barrier and/or capping layer and the conductor layer exhibit substantially identical etch rates in preferred etchants such as a PAN etch, i.e., a mixture of phosphoric acid, acetic acid, and nitric acid, which may be mixed with water and may be heated to elevated temperatures. Thus, etch-related residue and discontinuities are minimized or eliminated via use of the barrier and/or capping layers in accordance with preferred embodiments of the present invention.
In an aspect, embodiments of the invention feature a thin-film transistor that includes or consists essentially of a substrate and an electrode. The substrate may include or consist essentially of silicon and/or glass. The electrode includes or consists essentially of (i) disposed over or on the substrate, a barrier layer that includes, consists essentially of, or consists of an alloy of Cu and one or more refractory metal elements selected from the list consisting of Ta, Nb, Mo, W, Zr, Hf, Re, Os, Ru, Rh, Ti, V, Cr, and Ni, and (ii) disposed over or on the barrier layer, a conductor layer that includes, consists essentially of, or consists of Cu, Ag, Al, and/or Au.
Embodiments of the invention may include one or more of the following in any of a variety of different combinations. The substrate may include, consist essentially of, or consist of glass. The substrate may include, consist essentially of, or consist of silicon, e.g., amorphous silicon. The barrier layer may include, consist essentially of, or consist of an alloy of Cu, Ta, and Cr. The barrier layer may include, consist essentially of, or consist of 1 weight %-12 weight % Ta, 1 weight %-5 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of approximately 5 weight % Ta, approximately 2 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of 5 weight % Ta, 2 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of approximately 2 weight % Ta, approximately 1 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of 2 weight % Ta, 1 weight % Cr, and the balance Cu.
The barrier layer may include, consist essentially of, or consist of an alloy of Cu, Ta, and Ti. The barrier layer may include, consist essentially of, or consist of 1 weight %-12 weight % Ta, 1 weight %-5 weight % Ti, and the balance Cu. The barrier layer may include, consist essentially of, or consist of approximately 5 weight % Ta, approximately 2 weight % Ti, and the balance Cu. The barrier layer may include, consist essentially of, or consist of 5 weight % Ta, 2 weight % Ti, and the balance Cu.
The barrier layer may include, consist essentially of, or consist of an alloy of Cu, Nb, and Cr. The barrier layer may include, consist essentially of, or consist of 1 weight %-10 weight % Nb, 1 weight %-5 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of approximately 5 weight % Nb, approximately 2 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of 5 weight % Nb, 2 weight % Cr, and the balance Cu.
The electrode may include a sidewall including, consisting essentially of, or consisting of (a) an exposed portion of the barrier layer, (b) an exposed portion of the conductor layer, and (c) an interface between the exposed portion of the barrier layer and the exposed portion of the conductor layer. The sidewall of the electrode may be substantially, or even entirely, free of discontinuities notwithstanding the interface. The substrate may be substantially, or even entirely, free of Cu diffusion from the barrier layer. The barrier layer may include, consist essentially of, or consist of a plurality of crystalline grains separated by grain boundaries. At least one of the grain boundaries may include a particulate therein. The particulate may include, consist essentially of, or consist of a reaction product of silicon and at least one of the refractory metal elements.
In another aspect, embodiments of the invention feature a method of forming an electrode of a thin-film transistor. A substrate is provided. The substrate may include, consist essentially of, or consist of silicon and/or glass. A barrier layer is deposited over the substrate, and a conductor layer is deposited over the barrier layer. The barrier layer includes, consists essentially of, or consists of an alloy of Cu and one or more refractory metal elements selected from the group consisting of Ta, Nb, Mo, W, Zr, Hf, Re, Os, Ru, Rh, Ti, V, Cr, and Ni. The conductor layer includes, consists essentially of, or consists of Cu, Ag, Al, and/or Au. A mask layer is formed over the barrier layer, and the mask layer is patterned to reveal a portion of the conductor layer. A remaining portion of the mask layer may at least partially define a shape of the electrode. An etchant is applied to remove portions of the conductor layer and the barrier layer not masked by the patterned mask layer, thereby forming a sidewall of the electrode. The sidewall includes, consists essentially of, or consists of (a) an exposed portion of the barrier layer, (b) an exposed portion of the conductor layer, and (c) an interface between the exposed portion of the barrier layer and the exposed portion of the conductor layer. The sidewall is substantially, or even entirely, free of discontinuities notwithstanding the interface.
Embodiments of the invention may include one or more of the following in any of a variety of different combinations. The mask layer may include, consist essentially of, or consist of photoresist. The etchant may include, consist essentially of, or consist of a mixture of phosphoric acid, acetic acid, nitric acid, and water. The etchant may include, consist essentially of, or consist of 50-60 weight % phosphoric acid, 15-25 weight % acetic acid, 3-5 weight % nitric acid, and the balance water. The etchant may include, consist essentially of, or consist of 50 weight % phosphoric acid, 25 weight % acetic acid, 3 weight % nitric acid, and the balance water. The remaining portion of the patterned mask layer may be removed, e.g., after the etchant is applied. The barrier layer may include, consist essentially of, or consist of a plurality of crystalline grains separated by grain boundaries. The substrate may include, consist essentially of, or consist of silicon. The electrode may be annealed at a temperature sufficient to form a particulate within at least one of the grain boundaries (e.g., between 200° C. and 700° C., or between 300° C. and 500° C.). The particulate may include, consist essentially of, or consist of a reaction product of silicon and at least one of the refractory metal elements (e.g., a refractory metal silicide). The substrate may include, consist essentially of, or consist of glass or amorphous silicon.
The barrier layer may include, consist essentially of, or consist of an alloy of Cu, Ta, and Cr. The barrier layer may include, consist essentially of, or consist of 1 weight %-12 weight % Ta, 1 weight %-5 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of approximately 5 weight % Ta, approximately 2 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of 5 weight % Ta, 2 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of approximately 2 weight % Ta, approximately 1 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of 2 weight % Ta, 1 weight % Cr, and the balance Cu.
The barrier layer may include, consist essentially of, or consist of an alloy of Cu, Ta, and Ti. The barrier layer may include, consist essentially of, or consist of 1 weight %-12 weight % Ta, 1 weight %-5 weight % Ti, and the balance Cu. The barrier layer may include, consist essentially of, or consist of approximately 5 weight % Ta, approximately 2 weight % Ti, and the balance Cu. The barrier layer may include, consist essentially of, or consist of 5 weight % Ta, 2 weight % Ti, and the balance Cu.
The barrier layer may include, consist essentially of, or consist of an alloy of Cu, Nb, and Cr. The barrier layer may include, consist essentially of, or consist of 1 weight %-10 weight % Nb, 1 weight %-5 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of approximately 5 weight % Nb, approximately 2 weight % Cr, and the balance Cu. The barrier layer may include, consist essentially of, or consist of 5 weight % Nb, 2 weight % Cr, and the balance Cu.
In yet another aspect, embodiments of the invention feature a touch-panel display that includes or consists essentially of a substrate, a plurality of conductive touch-panel row sensors, a plurality of conductive touch-panel column sensors, and an interconnect. The row sensors are disposed over the substrate and arranged in lines extending along a first direction. The column sensors are disposed over the substrate and arranged in lines extending along a second direction and intersecting the lines of the row sensors. The interconnect is disposed at a point of intersection between a line of row sensors and a line of column sensors, and the interconnect electrically connects two column sensors or two row sensors. The interconnect includes, consists essentially of, or consists of (i) a conductor layer that includes, consists essentially of, or consists of Cu, Ag, Al, and/or Au, and (ii) disposed over or on the conductor layer, a capping layer that includes, consists essentially of, or consists of an alloy of Cu and one or more refractory metal elements selected from the list consisting of Ta, Nb, Mo, W, Zr, Hf, Re, Os, Ru, Rh, Ti, V, Cr, and Ni.
Embodiments of the invention may include one or more of the following in any of a variety of different combinations. The interconnect may extend over or under a row sensor and electrically connect two column sensors. An insulating layer may be disposed between the interconnect and the row sensor and may electrically insulate the interconnect and the row sensor. The interconnect may extend over or under a column sensor and electrically connect two row sensors. An insulating layer may be disposed between the interconnect and the column sensor and may electrically insulate the interconnect and the column sensor. The substrate may include, consist essentially of, or consist of an insulating material, e.g., glass. The row sensors and/or the column sensors may include, consist essentially of, or consist of a substantially transparent conductive material, e.g., indium tin oxide.
The capping layer may include, consist essentially of, or consist of an alloy of Cu, Ta, and Cr. The capping layer may include, consist essentially of, or consist of 1 weight %-12 weight % Ta, 1 weight %-5 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of approximately 5 weight % Ta, approximately 2 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of 5 weight % Ta, 2 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of approximately 2 weight % Ta, approximately 1 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of 2 weight % Ta, 1 weight % Cr, and the balance Cu.
The capping layer may include, consist essentially of, or consist of an alloy of Cu, Ta, and Ti. The capping layer may include, consist essentially of, or consist of 1 weight %-12 weight % Ta, 1 weight %-5 weight % Ti, and the balance Cu. The capping layer may include, consist essentially of, or consist of approximately 5 weight % Ta, approximately 2 weight % Ti, and the balance Cu. The capping layer may include, consist essentially of, or consist of 5 weight % Ta, 2 weight % Ti, and the balance Cu.
The capping layer may include, consist essentially of, or consist of an alloy of Cu, Nb, and Cr. The capping layer may include, consist essentially of, or consist of 1 weight %-10 weight % Nb, 1 weight %-5 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of approximately 5 weight % Nb, approximately 2 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of 5 weight % Nb, 2 weight % Cr, and the balance Cu.
The interconnect may include a sidewall that includes, consists essentially of, or consists of (a) an exposed portion of the capping layer, (b) an exposed portion of the conductor layer, and (c) an interface between the exposed portion of the capping layer and the exposed portion of the conductor layer. The sidewall of the electrode may be substantially, or even entirely free of discontinuities notwithstanding the interface. The capping layer may include, consist essentially of, or consist of a plurality of crystalline grains separated by grain boundaries. At least one of the grain boundaries may include a particulate therein. The particulate may include, consist essentially of, or consist of an agglomeration (e.g., an aggregation of atoms coming together via diffusion) of one or more of the refractory metal elements. One or more of the grain boundaries may contain a larger concentration of the refractory metal element(s) than the bulk volumes of the grains of the capping layer.
In another aspect, embodiments of the invention feature a method of forming an interconnect of a touch-panel display. A structure including or consisting essentially of a substrate, a plurality of conductive touch-panel row sensors, and a plurality of conductive touch-panel column sensors is provided. The row sensors are disposed over the substrate and arranged in lines extending along a first direction. The column sensors are disposed over the substrate and arranged in lines extending along a second direction and intersecting the lines of the row sensors. An insulator layer is deposited at least at a point of intersection between a line of row sensors and a line of column sensors. A conductor layer is deposited over the insulator layer, and a capping layer is deposited over or on the conductor layer. The conductor layer includes, consists essentially of, or consists of Cu, Ag, Al, and/or Au. The capping layer includes, consists essentially of, or consists of an alloy of Cu and one or more refractory metal elements selected from the group consisting of Ta, Nb, Mo, W, Zr, Hf, Re, Os, Ru, Rh, Ti, V, Cr, and Ni. A mask layer is formed over the capping layer. The mask layer is patterned to reveal a portion of the capping layer. A remaining portion of the mask layer may at least partially define a shape of the interconnect. An etchant is applied to remove portions of the capping layer and the conductor layer not masked by the patterned mask layer, thereby forming a sidewall of the interconnect. The sidewall includes, consists essentially of, or consists of (a) an exposed portion of the capping layer, (b) an exposed portion of the conductor layer, and (c) an interface between the exposed portion of the capping layer and the exposed portion of the conductor layer. The sidewall is substantially, or even entirely, free of discontinuities notwithstanding the interface.
Embodiments of the invention may include one or more of the following in any of a variety of different combinations. The mask layer may include, consist essentially of, or consist of photoresist. The etchant may include, consist essentially of, or consist of a mixture of phosphoric acid, acetic acid, nitric acid, and water. The etchant may include, consist essentially of, or consist of 50-60 weight % phosphoric acid, 15-25 weight % acetic acid, 3-5 weight % nitric acid, and the balance water. The etchant may include, consist essentially of, or consist of 50 weight % phosphoric acid, 25 weight % acetic acid, 3 weight % nitric acid, and the balance water. Any remaining portion of the patterned mask layer may be removed. The capping layer may include, consist essentially of, or consist of a plurality of crystalline grains separated by grain boundaries. The interconnect may be annealed at a temperature sufficient to form a particulate within at least one of the grain boundaries (e.g., between 200° C. and 700° C., or between 300° C. and 500° C.). The particulate may include, consist essentially of, or consist of an agglomeration of at least one of the refractory metal elements. The substrate may include, consist essentially of, or consist of an insulating material, e.g., glass. The row sensors and column sensors may include, consist essentially of, or consist of a substantially transparent conductive material, e.g., indium tin oxide.
The capping layer may include, consist essentially of, or consist of an alloy of Cu, Ta, and Cr. The capping layer may include, consist essentially of, or consist of 1 weight %-12 weight % Ta, 1 weight %-5 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of approximately 5 weight % Ta, approximately 2 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of 5 weight % Ta, 2 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of approximately 2 weight % Ta, approximately 1 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of 2 weight % Ta, 1 weight % Cr, and the balance Cu.
The capping layer may include, consist essentially of, or consist of an alloy of Cu, Ta, and Ti. The capping layer may include, consist essentially of, or consist of 1 weight %-12 weight % Ta, 1 weight %-5 weight % Ti, and the balance Cu. The capping layer may include, consist essentially of, or consist of approximately 5 weight % Ta, approximately 2 weight % Ti, and the balance Cu. The capping layer may include, consist essentially of, or consist of 5 weight % Ta, 2 weight % Ti, and the balance Cu.
The capping layer may include, consist essentially of, or consist of an alloy of Cu, Nb, and Cr. The capping layer may include, consist essentially of, or consist of 1 weight %-10 weight % Nb, 1 weight %-5 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of approximately 5 weight % Nb, approximately 2 weight % Cr, and the balance Cu. The capping layer may include, consist essentially of, or consist of 5 weight % Nb, 2 weight % Cr, and the balance Cu.
These and other objects, along with advantages and features of the present invention herein disclosed, will become more apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and may exist in various combinations and permutations. As used herein, the terms “approximately” and “substantially” mean ±10%, and in some embodiments, ±5%. The term “consists essentially of” means excluding other materials that contribute to function, unless otherwise defined herein. Nonetheless, such other materials may be present, collectively or individually, in trace amounts. For example, a structure consisting essentially of multiple metals will generally include only those metals and only unintentional impurities (which may be metallic or non-metallic) that may be detectable via chemical analysis but do not contribute to function. As used herein, “consisting essentially of at least one metal” refers to a metal or a mixture of two or more metals but not compounds between a metal and a non-metallic element or chemical species such as oxygen or nitrogen (e.g., metal nitrides or metal oxides); such non-metallic elements or chemical species may be present, collectively or individually, in trace amounts, e.g., as impurities. As used herein, “columns” and “rows” refer to elements arranged in different directions (and that may intersect), and are otherwise arbitrary unless otherwise noted; i.e., an arrangement of elements may be a row or a column, regardless of its orientation in space or within a device. As used herein, “substrate” or “base layer” refers to a support member (e.g., a semiconductor substrate such as silicon, GaAs, GaN, SiC, sapphire, or InP, or a platform including or consisting essentially of another material, e.g., an insulating material such as glass) with or without one or more additional layers disposed thereon, or to the one or more additional layers themselves.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the following description, various embodiments of the present invention are described with reference to the following drawings, in which:
FIG. 1A is a schematic cross-section of a thin-film transistor for a liquid crystal display;
FIG. 1B is a schematic cross-section of an etched conventional TFT electrode;
FIG. 2A is a plan-view schematic of the sensor array of a touch-panel display;
FIG. 2B is a magnified perspective view of a portion of the sensor array of FIG. 2A ;
FIG. 2C is a schematic cross-section of the sensor-array portion of FIG. 2B ;
FIG. 2D is a schematic cross-section, along a plane perpendicular to that of FIG. 2C , of the sensor-array portion of FIG. 2B depicting an etched conventional interconnect;
FIGS. 3 and 4 are schematic cross-sections of a TFT electrode during fabrication in accordance with various embodiments of the invention;
FIGS. 5 and 6 are schematic cross-section of an interconnect for a touch-panel display in accordance with various embodiments of the invention;
FIGS. 7A and 7B are Auger spectra graphs of mutual diffusion of Cu and Si without a diffusion barrier therebetween;
FIGS. 8A and 8B are Auger spectra graphs of mutual diffusion of Cu and Si between a Si layer and a Cu-alloy capping or barrier layer in accordance with various embodiments of the invention;
FIGS. 9A-9C are plan-view micrographs of the surface of a Cu-alloy capping or barrier layer as deposited ( FIG. 9A ), after annealing at 300° C. ( FIG. 9B ), and after annealing at 500° C. ( FIG. 9C ), in accordance with various embodiments of the invention;
FIGS. 10A and 10B are plan-view micrographs taken via scanning electron microscopy ( FIG. 10A ) and transmission electron microscopy ( FIG. 10B ) of an annealed Cu-alloy capping or barrier layer on Si, in accordance with various embodiments of the invention; and
FIG. 11 depicts corrosion levels after environmental corrosion testing of samples of pure Mo, pure Cu, CuTaCr alloy, and CuNbCr alloy in accordance with various embodiments of the invention.
DETAILED DESCRIPTION
FIG. 3 depicts an initial step in the fabrication of a TFT gate electrode in accordance with embodiments of the present invention. As shown, a barrier layer 300 is deposited on a substrate 310 (e.g., a glass or silicon substrate) by, e.g., sputtering or other physical deposition process. A conductor layer 320 is subsequently deposited on the barrier layer 300 by, e.g., sputtering or other physical deposition process. Typically the thickness of the barrier layer 300 will be between approximately 5% and approximately 25% (e.g., approximately 10%) of the thickness of conductor layer 320 . For example, the thickness of the barrier layer 300 may be approximately 50 nm, and the thickness of the conductor layer 320 may be approximately 500 nm. A mask layer 330 (e.g., photoresist) is formed over the conductor layer 320 and patterned by conventional photolithography.
As shown in FIG. 4 , a gate electrode 400 is then fabricated by etching the portions of the conductor layer 320 and barrier layer 300 not covered by the mask layer 330 , preferably in a single-step wet etch. A wet etchant (e.g., a PAN etch) is utilized to etch away the metal layers at substantially the same rates, resulting in sidewalls 410 that are substantially smooth and/or linear and that are substantially free of any discontinuity (e.g., a stepped or nonlinear profile) at an interface 420 between the conductor layer 320 and barrier layer 300 . The wet etchant may include or consist essentially of, for example, a PAN etch including or consisting essentially of 50-60 weight % phosphoric acid, 15-25 weight % acetic acid, 3-5 weight % nitric acid, and the balance DI water. Some specific examples are provided in the table below. In one preferred embodiment, the wet etchant includes or consists essentially of 50 weight % phosphoric acid, 25 weight % acetic acid, 3 weight % nitric acid, and the balance (22 weight %) DI water.
acetic acid,
DI water,
phosphoric acid,
nitric acid,
CH3COOH
balance
H3PO4 (wt %)
HNO3 (wt %)
(wt %)
(wt %)
etchant 1
50
5
15
30
etchant 2
60
5
20
15
etchant 3
50
3
25
22
After etching, the substrate 310 (as well as the electrode 400 ) is preferably substantially free of etch residue of one or both of the conductor layer 320 and the barrier layer 300 in regions proximate the gate electrode 400 . In accordance with various embodiments of the invention, the wet-etching process is performed at room temperature. The wet etchant may be sprayed on the substrate 310 , or the substrate 310 may be partially or completely immersed in the wet etchant. The wet-etching process may be performed as a batch (i.e., multiple-substrate) process or as a single-substrate process. In preferred embodiments, after etching the sidewalls 410 form an angle 430 with the surface of the underling substrate 310 of between approximately 50° and approximately 70°, e.g., approximately 60°. After etching, the mask layer 330 may be removed by conventional means, e.g., acetone, a commercial photoresist stripping agent, and/or exposure to an oxygen plasma.
FIG. 5 depicts an initial step in the fabrication of a touch-panel sensor interconnect in accordance with embodiments of the present invention. As shown, a conductive layer 500 is deposited over a sensor 510 (e.g., a row or column sensor that may be composed of a transparent conductor such as ITO) on a substrate 520 (e.g., a glass or silicon substrate) by, e.g., sputtering or other physical deposition process. A capping layer 530 is subsequently deposited on the conductive layer 500 by, e.g., sputtering or other physical deposition process. Typically the thickness of the capping layer 530 will be between approximately 5% and approximately 25% (e.g., approximately 10%) of the thickness of conductive layer 500 . For example, the thickness of the capping layer 530 may be approximately 50 nm, and the thickness of the conductive layer 500 may be approximately 500 nm. A mask layer 540 (e.g., photoresist) is formed over the capping layer 530 and patterned by conventional photolithography.
As shown in FIG. 6 , an interconnect 600 is then fabricated by etching the portions of the capping layer 530 and conductive layer 500 not covered by the mask layer 540 , preferably in a single-step wet etch. A wet etchant (e.g., a PAN etch) is utilized to etch away the metal layers at substantially the same rates, resulting in sidewalls 610 that are substantially smooth and/or linear and that are substantially free of any discontinuity (e.g., a stepped or nonlinear profile) at an interface 620 between the capping layer 530 and conductive layer 500 . The wet etchant may include or consist essentially of, for example, a PAN etch including or consisting essentially of 50-60 weight % phosphoric acid, 15-25 weight % acetic acid, 3-5 weight % nitric acid, and the balance DI water. In one preferred embodiment, the wet etchant includes or consists essentially of 50 weight % phosphoric acid, 25 weight % acetic acid, 3 weight % nitric acid, and the balance (22 weight %) DI water.
After etching, the substrate 520 and electrode 510 (as well as the interconnect 600 ) are preferably substantially free of etch residue of one or both of the capping layer 530 and the conductive layer 500 in regions proximate the interconnect 600 . In accordance with various embodiments of the invention, the wet-etching process is performed at room temperature. The wet etchant may be sprayed on the substrate 520 , or the substrate 520 may be partially or completely immersed in the wet etchant. The wet-etching process may be performed as a batch (i.e., multiple-substrate) process or as a single-substrate process. In preferred embodiments, after etching the sidewalls 610 form an angle 630 with the surface of the underling substrate 520 of between approximately 50° and approximately 70°, e.g., approximately 60°. After etching, the mask layer 330 may be removed by conventional means, e.g., acetone, a commercial photoresist stripping agent, and/or exposure to an oxygen plasma.
Barrier layers 300 and capping layers 530 in accordance with various embodiments of the invention also serve as effective diffusion barriers for metallic layers that include or consist essentially of, e.g., Cu, Ag, Al, or Au. Specifically, the alloying element(s) within the barrier layer 300 and/or capping layer 530 substantially prevent diffusion of a conductor layer material (e.g., Cu) into an underlying silicon substrate or an adjoining layer even after exposure to elevated temperatures (e.g., up to approximately 200° C., up to approximately 350° C., up to approximately 500° C., or even higher) for times of, e.g., up to 2 hours. FIGS. 7A and 7B show the concentrations of Cu and silicon across a Cu/silicon interface (i.e., one without a barrier layer between the Cu and silicon) as measured with Auger electron spectroscopy (AES) as fabricated (no anneal) and after anneals of 200° C.-500° C. As shown, mutual diffusion of the Cu and silicon occurs at temperatures as low as (or even lower than) 200° C., and the interface is severely diffused after an anneal at 500° C. Additionally, the Cu layer exhibits poor adhesion to silicon in the absence of a barrier layer between the Cu and silicon.
FIGS. 8A and 8B show the concentrations of Cu and silicon across an interface between silicon and a barrier layer 300 or capping layer 530 that includes or consists essentially of CuTaCr as measured with AES after no anneal and anneals of 200° C.-500° C. In the illustrated embodiment, the barrier layer 300 or capping layer 530 is composed of 2 weight % Ta, 1 weight % Cr, and the balance Cu. (In another embodiment exhibiting similar behavior, the barrier layer 300 or capping layer 530 includes or consists essentially of 5 weight % Ta, 2 weight % Cr, and the balance Cu.) In contrast to the results shown in FIGS. 7A and 7B , there is negligible diffusion of Cu or silicon across the interface, even after an anneal at 500° C. for two hours. FIGS. 9A-9C are a series of scanning electron microscopy (SEM) micrographs of the surface of the barrier layer 300 or capping layer 530 as deposited ( FIG. 9A ), after an anneal of 300° C. for one hour ( FIG. 9B ), and after an anneal of 500° C. for one hour ( FIG. 9C ). As shown, the grain structure and size of the barrier layer 300 or capping layer 530 show no appreciable change, and there is no evidence of the formation of different phases (e.g., copper silicide phases) even after a heat treatment of 500° C. These results were confirmed by x-ray diffraction (XRD) scans of annealed structures, in which no silicide phases were detected even after anneals of 500° C. for two hours. In contrast, copper silicide phases are clearly evident in SEM and XRD performed on samples of pure Cu layers on Si that have been annealed at 500° C. for two hours.
FIGS. 10A and 10B show, respectively, SEM and transmission electron microscopy (TEM) images of a barrier layer 300 or capping layer 530 that is disposed in contact with silicon (e.g., a silicon substrate and/or a silicon overlayer) and that has been annealed at 350° C. for 30 minutes. Precipitates 1000 are evident within the Cu grain boundaries 1010 of the barrier layer 300 or capping layer 530 . In various embodiments the precipitates include or consist essentially of a silicide of one or more of the refractory metal alloying elements of the barrier layer 300 or capping layer 530 , and such precipitates reduce or substantially eliminate Cu diffusion along the grain boundaries into the adjoining silicon.
Similarly, in various embodiments of the invention, the refractory-metal dopants of barrier layers 300 and/or capping layers 530 tend to segregate to the Cu grain boundaries and provide beneficial effects even in the absence of reaction with silicon to form silicides. For example, the Cu grain boundaries may be occupied, and partially or substantially completely “blocked” with the refractory-metal dopants and thereby retard or substantially prevent oxygen diffusion along the Cu grain boundaries. In this manner, corrosion of the barrier layer 300 , capping layer 530 , and/or the conductive layer in contact therewith is decreased or substantially prevented. Thus, in various embodiments of the present invention, a barrier layer 300 or capping layer 530 may include or consist essentially of a polycrystalline Cu matrix doped with one or more refractory metal elements, where the grain boundaries of the layer between the doped Cu grains contain a higher concentration of the refractory metal dopant(s) that the concentration within the grains themselves. For example, the refractory metal concentration within the grain boundaries may be larger than that within the grains by a factor of 5, a factor of 10, or even a factor of 100.
FIG. 11 depicts images of four different metallic samples after an environmental corrosion test conducted at 60° C. and 80% humidity for a period of 260 hours. As shown, the samples of pure Cu and pure Mo experienced much more severe corrosion that did the Cu-alloy samples in accordance with embodiments of the present invention. The two Cu-alloy samples were (1) Cu with 10 weight % Ta and 2 weight % Cr (labeled in FIG. 11 as CuTaCr), and (2) Cu with 5 weight % Nb and 2 weight % Cr (labeled in FIG. 11 as CuNbCr). The table below provides data regarding the amount of exposed surface area corroded during the environmental corrosion test for each of the samples. As indicated, the Cu-alloy samples in accordance with embodiments of the present invention experienced much less corrosion than the pure Cu and Mo samples, demonstrating the benefits of such alloys over conventional Mo diffusion barriers and capping layers, as well as over pure Cu.
Sample
Corroded Surface Area (%)
Mo
6.78
Cu
3.84
CuTaCr
1.75
CuNbCr
0.83
In preferred embodiments of the invention, the barrier layers 300 or capping layers 530 have low resistivity, e.g., below 10 microOhm-cm, or even below 5 microOhm-cm, even after anneals of up to 500° C., up to 600° C., or even higher temperatures. Moreover, in preferred embodiments the barrier layers 300 or capping layers 530 exhibit good adhesion to glass as measured by, e.g., an ASTM standard tape test. Embodiments of the invention also include electronic devices (or portions thereof) in which a highly conductive material (e.g., Cu, Ag, Al, and/or Au) is utilized to form all or a portion of a conductor or electrode and has both a barrier layer 300 below it and a capping layer 530 above it.
The terms and expressions employed herein are used as terms and expressions of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described or portions thereof. In addition, having described certain embodiments of the invention, it will be apparent to those of ordinary skill in the art that other embodiments incorporating the concepts disclosed herein may be used without departing from the spirit and scope of the invention. Accordingly, the described embodiments are to be considered in all respects as only illustrative and not restrictive. | 4y
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CROSS REFERENCE TO RELATED PATENTS
The present invention is an improvement over the methods disclosed in the present inventor's U.S. Pats. No. 4,053,348, No. 4,102,735, No. 3,758,350, assigned to the assignee of the present invention; all of which are incorporated herein by reference and relied upon.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, generally, to methods for forming dies by chemical milling and the resulting dies and, more especially, to methods for improving the processability of steel dies destined to be circuit stamping dies used to fabricate circuit boards.
2. Description of the Background Art and Technical Problems
The present inventor's U.S. Pat. No. 3,758,350, entitled "Method of Making a Die for Stamping Out Circuit Boards", discloses a method for etching a die block to form an improved die particularly adapted for manufacturing a relatively compact circuit board where the circuit elements are of relatively small width and with small separation therebetween. In that method, first there is formed a conventional flat face die, comprising flat face die elements with intervening recess areas, this being accomplished in a conventional manner. Then the recess areas are filled with an etchant-resistant filler such as epoxy, and a photo resist is applied over the filler in a manner to overlap the outer edge portions of the die elements so that the middle portion of each die element is etchant active. The die is then exposed to an etching medium, such as ferric chloride, to form die element recess in the middle portion of each die element with shoulders along the edge portions thereof. Next the resist material is removed and, with the filler still remaining in the recess, the die surface is again etched for a short period of time. In one procedure the final etching is done in a manner to provide "modified" die element edge portions where the inner edge surface of each die element edge portion is somewhat rounded, and in another procedure the final etching is accomplished in a manner to provide a knife edge die.
The methods disclosed in the aforementioned patent have proven quite effective in making precision dies for the stamping of circuit boards and the trimming of circuits borne on flexible substrates. Nonetheless, certain improvements over those basic techniques have been made by the present inventor, particularly relating to the manufacture of dies for stamping circuit boards from heavier foil. It has now become somewhat commonplace to use thicker foil elements in the manufacture of circuit boards to achieve, for example, the ability of the board to carry higher current loads. In turn, this has somewhat complicated the design of suitable dies for that purpose.
In a circuit board manufacturing operation it is desirable to accomplish both the forming of the circuit elements from the foil sheet and the bonding of these circuit elements to a dielectric substrate in one stamping operation. This is usually accomplished by providing a thermo-adhesive coating between the foil sheet and the substrate and heating the die prior to the stamping operation. When the heated die is brought into engagement with the foil sheet, the die elements press into the foil sheet to separate the circuit elements therefrom and press these elements into firm engagement with the substrate while heating the underlying adhesive layer to cause bonding of the circuit elements thereto. The excess foil adjacent the die elements does not become bonded to the substrate, and this excess foil is simply stripped away from the dielectric material after the stamping sequence.
When it is attempted to use heavier foils to make circuit boards where the width and spacing of the elements are quite small, the problems of accomplishing this simultaneous forming and bonding of the circuit elements properly are greatly aggravated. First, with regard to the individual die elements, the edge portions of each element must be of a height sufficient to cause a separation through the entire thickness of the foil sheet. Second, the depth of the recess area of the die must be sufficient to permit the excess foil to become positioned in the recesses during the stamping operation, without the excess foil becoming bonded to the substrate. Thus, the recessed areas of the die must have a depth sufficient to accommodate the excess foil, while the die elements must have and retain a sharp cutting profile lest a dull or rounded edge leaves a small ribbon of foil which can bridge the circuit elements to yield an undesired electrical connection. These same considerations are equally applicable to trimming dies used to trim circuits on a flexible substrate. Accordingly, it is important that the raised die elements be formed precisely to avoid this unacceptable result. It is also important to the precision of any subsequent sharpening procedure that the raised stamping element be formed precisely.
Although the goal of forming raised die elements in a very precise pattern and within carefully controlled tolerances is easily articulated, realization of that goal is sometimes quite elusive. Notwithstanding the high technological development in the art, it too often occurs that the raised elements in the die are imperfectly formed regardless of the care taken to prepare and then process the die blank. Suprisingly, a die blank believed to be of high quality steel and prepared with care will sometimes be found to have raised die elements inexplicably out of tolerance or rounded resulting in the need either to scrap the die and begin again or to undertake tedious, labor-intensive efforts to salvage that die. Considerable effort and capital resources have been expended to detect, if not understand, how and why seemingly properly prepared die blanks surprisingly run out of tolerance during intermediate fabrication techniques.
SUMMARY OF THE INVENTION
Identification Of The Threshold Problem
The methods for forming precision dies include chemical milling of a metallic die block, typically a low carbon steel or air hardening or oil hardening tool steel. The etchant most often employed is ferric chloride which will preferentially attack the exposed metal surfaces of the die block, but against which etching action the photo resist and the underlying epoxy fill remain passive. It has now been learned, however, that the epoxy fill itself (which is loaded within the cavities of a foil cutting die to support the dry film resist layers and protect the cavity side of the die during the chemical milling operation) sometimes is not perfectly adhered near the cavity edge proximate the location of a raised die element. It has also been detected that the epoxy fill sometimes will separate slightly from the metal substrate during subsequent processing; for example, due to thermal shock as the die is intermittently etched in a bath at about 100° F. and rinsed in water at about 65-70° F. In either event, this tendency toward void formation initially or during later processing will in turn tend to allow the penetration of etchant within the slight void between the epoxy within a cavity and the side of a die element, which should not be etched if optimum quality of the finished die is to be maintained. While this is a particularly vexing problem, where the die element being formed is destined to be a knife edge the problem is exacerbated due to the very small dimension of the edge itself and the preferential etchant attach which occurs along a sharp line or at a point. Thus, the ability of the etchant to remove material from both sides of a given die element edge due to the ability to penetrate within a void resulting from imperfect bonding of the epoxy likely will cause an uncontrollable etching procedure where that die element edge is out of tolerance with a corresponding edge. More often than not, the entire die must be scrapped.
Pinpointing slight separation between the epoxy (or other filler) and the cavity edge as the significant contributing factor to imperfect die edge formation was somewhat problematic. If the void is macroscopic and easily detectable, the typical remedy in the past has been to strip the fill and refill the cavity before etching. However, microscopic voids, even those imperceptible under 40X magnification, have now been appreciated by the present inventor to lead to the disasterous results noted above. That such small, unseen voids or separations could have this effect was not at all apparent in the first instance, notwithstanding the demonstrable adverse consequences.
This problem is not confined to the manufacture of circuit stamping or trimming dies, but occurs or can occur in any chemical milling operation where a polymeric fill is used as a mask and/or support for a dry film resist. It is, however, a particularly severe problem in the context of circuit board stamping dies since precisional tolerances must be maintained extremely close. Attempts to relieve uncontrollable etching due to imperfect bonding of filler materials by locating more stable filler compositions or better control in the application of the filler to the partially formed dies have not met with commercially-acceptable success. Accordingly, now that the problem has been identified, the need still exists to find a way to eliminate the problem of uncontrollable etching due to imperfect bonding of epoxy masking and/or support fills.
SUMMARY OF THE SOLUTION
The present invention advantageously provides a means for insuring a uniformity of etching action even in situations where slight voids may exist betwen the, e.g., epoxy fill and the cavity within which it is loaded. Thus, the present invention desirably permits one to achieve closely held tolerances during chemical milling procedure, which procedure is not as sensitive to the presence of inadvertent voids between the epoxy fill within a cavity and the metal substrate proximate a raised die element.
These and other advantages are achieved in a method for making a die, by chemical milling an etchable workpiece in a series of etching procedures to yield raised die elements separated and bounded by recessed cavities, wherein at least one etching sequence comprises etching a partially formed workpiece having at least selected ones of the recessed cavities provided with an underlayment film of an etchant-resistant composition beneath the etchant-resistant filler. Thus, even should there occur initial or subsequent partial separation of the fill from the metal substrate, any void thereby formed remains etchant-passive by virtue of the passive underlayment film.
In one aspect of the present invention, the method comprises the steps of initially partially etching a steel workpiece to form raised die element precursors separated and bounded by recessed cavities, depositing a film of an etchant-resistant composition on the workpiece in at least selected ones of the recessed cavities, filling the cavities wherein the film has been deposited with an etchant-resistant filler, and subsequently etching the workpiece in the normal manner. That preferred method includes depositing the film by an electro-deposition technique, and more preferably by electroplating a film selected from the group consisting of gold and platinum. Preferably, the film is applied to the entire work face of the partially formed die and is then removed from selected regions. In one variant, the metal die is plated with gold or platinum (more preferably gold) on its working face, the plated die is then surface ground to remove the film from the raised surfaces of the die, and epoxy fill is then loaded within the recessed cavities bearing the etchant-resistant film. The die is then processed in accordance with the techniques disclosed in one or more of the present inventor's U.S. Pats. No. 3,758,350, No. 4,053,348, and No. 4,102,735.
When the chemical milling procedure is completed, the epoxy or other filler is removed from the recessed cavities and the die is ready for operation. Not only is the die produced by the aforementioned preferred technique one which does not tend to suffer from uncontrollable and unwanted etching proximate the die elements, the retained gold film tends to provide a certain amount of lubricity to the die during subsequent use.
Other advantages and applications of the present invention will become apparent, and a fuller understanding gained, by reference to the following detailed description of the invention, taken in conjunction with the figures of drawing, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-3 are sectional views of a portion of a die block at various intermediate stages in the formation of raised die elements;
FIG. 4 is an enlarged sectional view of a portion of a finished die showing a completed die element;
FIG. 5 is an enlarged, fragmentary sectional view of one of the die elements shown in FIG. 2, further illustrating a situation where a void exists adjacent the die element;
FIG. 6 is an enlarged fragmentary sectional view of the die element of FIG. 5 following etching;
FIG. 7 is a view similar to FIG. 5, but showing the interposition of an etchant-resistant film underlayment below a fill in the die cavities; and,
FIG. 8 is a view of the die element of FIG. 7 following a subsequent etching operation.
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates, generally, to the fabrication of precision dies and, more especially, to such dies which are destined for the manufacture of circuit boards. Further along these lines, the present invention resides in part in the identification of heretofore unappreciated and undetected sources of problems in die fabricating techniques and resides in equal part in a solution therefor. Accordingly, the invention will now be described with reference to certain preferred embodiments within that context; although those skilled in the art will appreciate that such a description is meant to be exemplary only and should not be deemed limitative.
A pervasive problem in the processing of precision dies by chemical milling is the lack of control of the etching process which can occur when an etchant-resistant fill disposed within cavity to protect the same is not bonded properly to the face of that cavity. This can allow etchant to migrate within a void between the metal die block and the fill, whereby the die element being formed by the etching procedure loses its dimensional tolerance.
It can be appreciated that this problem becomes especially critical in fabricating circuit stamping dies, where it is attempted to form the edge portions of the individual die elements within quite close tolerances (e.g., on the order of one thousandth of an inch or less) so that these can properly perform their function of separating the quite small circuit elements from the foil, which circuit elements may be as small as 0.010" wide. Not only is this precision of importance in the initial formation of the die, but also with regard to future maintenance of the die. As the edge portions of the individual die elements become worn, resharpening becomes necessary and with the very small dimensions involved this resharpening can best be accomplished by means of etching. Such resharpening can only be accomplished properly if the initial formation of the die elements is within proper tolerances.
In one aspect of the present invention, the uncontrollable etching due to void formation or imperfect adherence between an epoxy fill and a cavity in a metallic die block is minimized by first applying to selected areas of the die block a film of an etchant-resistant material as an underlayment for the epoxy fill. Thus, even if etchant is able to penetrate the void, it will encounter a passive surface notwithstanding the presence of that void.
Turning to the figures of drawing, in all of which like parts are identified with like reference numerals, FIGS. 1-3 illustrate cross-sections of a die block at various stages in a chemical milling procedure to produce raised die elements which may be destined for stamping circuit boards. For the sake of brevity, reference is made to the present inventor's U.S. Pats. No. 3,758,350, No. 3,911,716, No. 4,053,348, and No. 4,102,735, for a complete discussion of the manner in which the chemical milling process is utilized for the formation of the die elements shown in these figures.
Briefly stated, a die block designated generally as 10 is formed with a plurality of raised die elements designated generally as 12, a separating cavity 14 disposed intermediate the die elements and background cavities 16 outwardly bounding the region of die elements. Each die element includes a die element recess 18 separating opposing edges or shoulders 20. This profile of die elements and cavities is preferably formed in a step-back sequence of etching--first, where the overall region of die elements is masked and the background cavities formed; second, where the individual die element regions are masked and the separating cavities formed; and, third, where the background and separating cavities are masked and the die element cavities formed. This step-back procedure is disclosed in the aforementioned patents, forms no part of the present invention, and thus further background information can be obtained by reviewing those references.
FIG. 1 illustrates a die 10 nearing the last stages of formation of die elements 12. The background and separating recesses within metal die block 10 are loaded with a filler designated generally as 22, such as an epoxy filler. The epoxy fill, which is an etchant-resistant material, serves to protect the cavities 14 and 16 during etching, while the upper surface of the fill serves to support a photo resist layer 24 used to mask selected areas of the die block during the chemical milling procedure.
The die block 10 is exposed to an etchant, such as ferric chloride, which, due to the resist layer 24 and epoxy fill 22, is capable of removal of material only from the die element cavities 18 since the remaining areas are protected by the film 24. As etching proceeds, the die element edges 20 become progressively thinner as the cavity 18 is etched toward the separating and background cavities 14 and 16, respectively. When this step has proceeded to an appropriate extent, the die is washed and the resist layer 24 is removed to yield the intermediate configuration of FIG. 2.
As can be seen in FIG. 2, the die elements 12 still retain a thickness at the upper working surface of the die where the edges 20 are being formed. When it is desired to form a knife edge element, such as the one shown in detail in FIG. 4, the die block is subjected to a further etching treatment with, e.g., ferric chloride. Again, due to the epoxy fill 22, etching proceeds within the die element cavities 18 and material is removed from the walls thereof to reduce further the transverse dimension of the die element edges 20. This reduction occurs both laterally and transversely and, upon completion, yields the die block illustrated in FIG. 3. At this stage, the etching procedure is terminated, the die is washed and cleaned thoroughly, and the epoxy fill 22 is stripped therefrom to yield a precision die having raised die elements 12 shown in enlarged view in FIG. 4.
The foregoing general description of the etching procedure is now somewhat conventional and is well disclosed in the previously mentioned United States patents. FIGS. 5 and 6 show how the presence of an imperfect bond between the epoxy fill 22 within the cavities separating a given die element can contribute to a loss of tolerance of the knife edges 20.
FIG. 5 is an enlarged view of a portion of the die shown in FIG. 2. As can be seen, the knife edges 20 have a top profile which is to be removed in a sharpening operation by etching with ferric chloride.
In the die of FIG. 5, the epoxy fill 22 in the background recess 16 is shown to be separated from the side face of the cavity proximate the die element edge 20, to yield a void or space 26 (the dimension of which is somewhat exaggerated for the sake of clarity) leading from the top surface of the die 10. Thus, when the die is exposed to etchant, that etchant may seep within the void 26 and remove the portion of die element edge 20 on the side adjacent the void 26, that edge being identified as 20'. This will yield a low, rounded, dull edge 20", as shown in FIG. 6. In turn, the die resulting from this operation will not exhibit the high precision needed for stamping, e.g., circuit boards.
FIGS. 7 and 8 parallel the die represented in FIGS. 5 and 6, respectively. However, the cavities 14 and 16 are first imparted with an underlayment of a film of an etchant-resistant composition 28. Accordingly, where an inadvertent void 26 results from an imperfect bonding of the epoxy fill or from subsequent shrinkage thereof during a cure or for any other reason, any etchant which may migrate within the void will find passive surface which may not be etched. Consequently, sharp, well defined uniform edges are imparted to the die elements 12 as etching and removal of material from the die can proceed only from within the die element cavity 18.
The preferred material for film 28 is gold since it is highly resistant to attack by ferric chloride, the most preferred etchant for dies of the variety with which the present invention is involved. After the background and separating cavities are formed but prior to filling these cavities with epoxy, the die is first thoroughly scrubbed with an abrasive such as aluminum oxide (e.g. 240 grit) to remove carbon deposits or other contaminants which might be present at the surfaces of the die. All of the surfaces of the die, save the cutting or working face, are masked and gold is then plated in accordance with conventional procedures to yield a film preferably from about 0.00005 to about 0.00015", and most preferably about 0.0001". The passive film is then removed from those areas where etching is to occur and the die is processed in accordance with the foregoing procedures for chemical milling to yield the sharp cutting edges 20. A particularly preferred method for removing the passive film from the working areas (e.g. those where die elements 12 are to be formed) is by surface grinding the top face of the die, although any other desirable method might be used to achieve this end.
While gold is the most preferred composition for the film underlayment, any material which is passive to the etchant employed might equally well be used to good advantage. For example, platinum might be utilized in lieu of gold. And, even though these are fairly expensive materials, the thin layer employed minimizes the overall cost of using such precious metals. For example, at current prices, a six inch by nine inch die can be electroplated with gold having a value of little more than about $5.00. The metallic films are also preferred for ease of deposition, since the same may be electroplated directly onto the steel substrate. Although plating gold onto steel normally requires an underlying flash of other metal (such as nickel), since the purpose of the plating here is to provide an etchant passive surface and not necessarily an integral permanent bond between the the gold film and the steel substrate, the electroplating procedure need not be as complicated as to require intermediate layers of compatible constituents.
While electroplating is the preferred technique for depositing the metallic film, other techniques might be used. For example, a standard electroless plating process where a solution or paste is applied and then reduced to metallic form might be employed. Likewise, the film might be sputtered onto the die face if that be desirable. Other techniques will occur to those skilled in the art, as well as other suitable compositions for the underlayment.
Regardless of the deposition technique, it is somewhat surprising that such thin films of passive elements such as gold or platinum have the demonstrable, beneficial effects realized by practicing the present invention. For example, were a film of gold to be plated to a thickness of about 0.0001-0.00015" on an open area of a die, that film would not be expected to function in an acceptable manner as a resist film. To the contrary, it would be expected to break down at least locally and fail to provide an efficient, etchant-resistant mask. Nonetheless, as an underlayment film, these materials are found exceedingly beneficial in obtaining high quality precision dies through chemical milling techniques.
When the preferred underlayment film of gold is employed, it not only serves to guard against unwanted etching as aforesaid, the retained gold film is believed to impart better operational characteristics to the die ultimately formed. For example, it is believed that the retained gold film will provide a measure of improved lubricity to the die when used in a subsequent stamping operation. This is an important advantage in providing dies with better stamping characteristics and better longevity.
While the invention has now been described with reference to certain preferred embodiments, those skilled in the art will appreciate the various substitutions, modifications, changes and omissions that may be made without departing from the spirit thereof. Accordingly, it is intended that the scope of the present invention be limited solely by that of the claims granted herein. | 4y
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BACKGROUND OF THE INVENTION
This invention relates to infusion pumps for administering fluid from a fluid source to a patient. More particularly, the invention relates to a highly portable, compact, pump having readily disposable and replaceable cassette-type pump and value components, and capable of administering fluid to a patient at a flow rate which is substantially continuous and precisely controlled.
Previous infusion pumps for supplying fluids to patients can be classified generally as syringe type and peristaltic type. Among the syringe type infusion pumps are those shown in the following U.S. Pat. Nos. 3,447,479; 3,701,345; 3,731,679; 3,739,943; 3,858,581; 3,901,231; 3,985,133; and 4,367,435. These syringe pumps all share the common characteristic of employing an electric motor to drive the plunger of a syringe so as to expel fluid therefrom at a controlled flow rate for administration to a patient. All syringe pumps likewise share the common problem of being incapable of providing a substantially continuous flow rate to the patient because of the necessity to interrupt delivery of the fluid while the plunger is being retracted to refill the syringe after it has been emptied. The resultant intermittent interruption of fluid flow to the patient during such refilling introduces a troublesome variable into flow rate planning, requiring higher than optimum flow rates during delivery of the fluid to make up for the intermittent interruptions in flow so that the time-averaged flow rate to the patient will be optimal. Unfortunately, the necessity for higher than optimal flow rates interspersed with interruptions thereof can cause both harmful excessive concentrations of infused fluids at some times, and harmful insufficient concentrations at other times. The peristaltic type infusion pumps such as those shown in U.S. Pat. Nos. 3,736,930, 3,737,251 and 3,841,799, on the other hand, although providing substantially continuous flow, do not have the necessary accuracy of flow rate control provided by the syringe-type pumps and cannot therefore be used where a high degree of precision is required.
Another problem with prior infusion pump units is that their pumping and valving structures, even when provided in easily replaceable cassette form, lack the compactness and simplicity to provide a high degree of portability and versatility for both hospital and home use. Although some units, such as those shown in U.S. Pat. Nos. 3,456,648 and 3,994,294, employ simplified valving which utilize tube-deforming devices for selectively opening and closing fluid conduits, the means of packaging such simplified valving systems in a highly compact, replaceable cassette form have not been known.
Although highly accurate stepper motors have been used to control infusion pump flow rates, as exemplified by the aforementioned U.S. Pat. Nos. 3,736,930 and 3,985,133, the frequency control of pulses driving such motors does not provide adequate insurance that the commanded flow rate will actually occur, particularly under variable back pressure conditions. The same is true of pulsed, nonstepping motors utilized in pumps such as those shown in the aforementioned U.S. Pat. Nos. 3,858,581 and 4,367,435, where transient load conditions may likewise prevent the motor from moving in accordance with the drive pulses. Moreover, the aforementioned pulsed electric motors do no have optimal energy efficiency characteristics which enable them to maximize the life of a battery power source, which would enhance their portability. Usually the drive pulses are of a constant duration which is longer than necessary to advance the motor the necessary amount against normal back pressures, thereby consuming excess power.
Finally, although a number of the prior infusion pump devices include occlusion detection systems, such as those shown for example in U.S. Pat. Nos. 3,731,679 and 3,985,133, such systems provide insufficient control over the likelihood that a partial occlusion, such as a partially obstructed or pinched fluid outlet, will disable the system. Accordingly, in some cases, disabling occlusions occur with excessive frequency, requiring excessive supervision and correction by an attendant.
SUMMARY OF THE PRESENT INVENTION
The present invention is directed to an infusion pump having mutually-compatible features which overcome all of the foregoing drawbacks of the prior art. The pump may be used for intravascular, body cavity, enteral and other similar infusions.
Substantially continuous flow is made compatible with highly accurate volumetric flow control by employing a dual chamber piston and cylinder assembly with associated valving which pumps fluid to the patient at a predetermined volumetric flow rate while simultaneously drawing fluid from the fluid source at the same flow rate. Thus no interruptions of the flow for refilling are necessary, and the discharge flow rate is thus the actual desired optimum flow rate rather than a higher than optimal flow rate. These objectives are achieved in a pump housed in a highly compact, inexpensive, disposable cassette despite the need for twice as many pumping chambers and twice as much input-output valving as is employed in prior syringe-type pumps. This is made possible by the utilization of pairs of deformably-closable input-output tubes within the cassette structure, each pair being connected to a respective pump chamber, with a simple tube closure structure movably mounted on the cassette for controlling the selective opening or closing of all of the tubes simultaneusly.
Improved reliability with respect to maintaining the desired fluid flow rate under variable load conditions, and improved energy efficiency of the pumping motor to enhance the battery-powered portability of the pumping unit, are achieved in the present invention by a motor system which initiates motor driving electrical pulses at an adjustably variable, predetermined time rate dependent upon the desired flow rate, but terminates each of such pulses not on the basis of time but rather on the basis of position attained by the motor in response to the pulse. This control system has the advantage of shortening the duration of each electrical pulse if light load conditions permit the motor quickly to attain a predetermined increment of advancement in response to a pulse, thereby saving energy. Alternatively, the system provides longer pulse durations if high load conditions, in the form of high back pressure, tend to retard the advancement of the motor in response to each pulse. Such variable, load-dependent pulse durations increase the likelihood that the pump will reliably deliver the required increment of fluid in response to each electrical pulse even under conditions of high loading.
Finally, the occlusion-detection system of the present invention, which monitors the average rate of movement of the pump-motor, is accompanied by a system for controllably varying the time-averaged electrical current driving the pump motor so as to controllably vary the maximum pressure of fluid pumped to the patient. This enables the operator to vary the degree to which the infusion pump is susceptible to being retarded by back pressure, enabling the use of different pumping pressures when appropriate to compensate for loading conditions which vary from patient to patient. Thus, for example, if a particular patient has a propensity for retarding the pump with excessive frequency, the operator has the ability to correct this problem by increasing the electrical current to raise the pump's output pressure.
The foregoing and other objectives, features and advantages of the present invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an exemplary embodiment of the infusion pump of the present invention, showing the base housing with a cassette inserted therein.
FIG. 2 is an enlarged, side-sectional view of the infusion pump of FIG. 1.
FIG. 3 is a cross-sectional view taken along line 3--3 of FIG. 2.
FIG. 4 is a side-sectional view of the cassette employed in the pump of FIG. 1.
FIG. 5 is a cross-sectional view of the cassette taken along line 5--5 of FIG. 4.
FIG. 6 is an enlarged, extended sectional view of the valve assembly of the cassette shown in its condition when the pump piston is moving in one direction.
FIG. 7 is an enlarged, extended sectional view of the valve assembly similar to that of FIG. 6 showing the condition thereof when the pump piston is moving in the opposite direction.
FIG. 8 is a front view of the control panel of the infusion pump of FIG. 1.
FIG. 9 is a block diagram of the major control circuit components of the pump of FIG. 1.
FIG. 10 is a diagram of the general functions of the microcomputer (MCU) of FIG. 9.
FIG. 11 is a schematic diagram showing an exemplary system by which the rotary position of the pump drive motor can be sensed using Hall effect sensors.
FIG. 12 is a schematic diagram showing an exemplary sequence by which the three phases of the pump drive motor may be commutated.
FIG. 13 is a schematic diagram showing the relationship between position-sensing and commutation of the pump drive motor in accordance with FIGS. 11 and 12.
FIG. 14 is a table showing the pump drive motor commutation sequence in reversible directions in accordance with FIG. 13.
FIG. 15 is a schematic diagram of an exemplary pump drive motor and valve motor control circuit.
FIG. 16 is an exemplary logic flow diagram according to which the microcomputer of the unit is programmed to control the pump drive motor.
DESCRIPTION OF THE PREFERRED EMBODIMENT
General Arrangement
The exemplary embodiment of the infusion pump of the present invention, indicated generally as 10 in FIG. 1, comprises a base member 12 which detachably houses an insertable cassette 14, both of which may be of impact-resistant plastic construction. The base 12 essentially consists of a rectangular housing having major sidewalls 16 and 18 and ends 20 and 22, with interior partition 24, 26 and 28 defining battery compartments 30 and 32, partition 34 and end 22 defining a motor compartment 36, and ribs 38 and 40 together with end 20 defining a cavity into which the cassette 14 can be matingly inserted as shown in FIGS. 1-3. When so inserted, the major sides of the cassette are engaged by the ribs 40 and held in place by opposing pairs of detents 42 mounted in the ribs 40 which engage mating depressions in the sides of the cassette 14. The cassette is also restrained against movement along its length by the engagement of one of its ends with the end 20 of the base 12, and the engagement of its opposite end with a lug 38a protruding upwardly from the rib 38 upon which the cassette rests, as shown in FIG. 2.
Mounted on the partition 34 within the base 12 are a bidirectional pump-motor 44 and a bidirectional valve motor 46. The valve motor 46 is preferably a conventional linear actuator stepper motor having high reluctance or "cogging" force for holding position without energizing of the coils, so as to be capable of maintaining the valve assembly in the desired position without consuming battery power. The pump-motor 44, on the other hand, is a rotary motor preferably having little or no cogging torque. Both motors are powered by four rechargeable batteries which may be inserted in battery compartments 30 and 32 or, alternatively, by an external DC source.
Mounted on the drive shaft 44 of the pump-motor 40 is a screw member 48 threadably engaging the base of a U-shaped drive yoke 50 having a pair of spaced-apart legs 50a and 50b which straddle the sides of the cassette 14 when it is inserted in the base 12 as shown in FIGS. 2 and 3. Turning of the pump-motor 44 in one direction moves the yoke 50 away from the motor, while turning of the motor in the opposite direction retracts the yoke 50 toward the motor, the yoke being slidably supported for such reciprocative movement on the partition 24. The drive shaft 46a of the linear valve motor 46 is attached to an L-shaped valve controller 54, which reciprocates with respect to the motor 46 in a direction parallel to the direction of reciprocation of the yoke 50.
The base 12 also includes a control panel 56 attached to the side 18 of the base member. The control panel includes an LCD 58 for displaying total volume to be infused (cc), volumetric rate of infusion (cc/hr), volume currently infused, minimum rate of infusion to keep a vein open following total infusion (KVO), and output pressure setting. In addition, the lCD displays operating messages which assist the user in the input of new pump control settings, interpretation of error conditions, and determination of the unit's present operating mode. A key pad 60 permits the user to input desired settings by first pressing the "HALT/DATA" key, selecting the value to be modified by pressing one of the four "SET" keys, and then inputting the setting by depressing the appropriate numeric keys. The key pad 60 also provides a key for actuating a "PURGE" mode of the pump for the clearing of air from the system by running the pump at high speed while connected to the fluid source but not to the patient.
The electronic control circuitry for the unit, to be explained hereafter, is mounted within the control panel 56 and on the interior surface of the side wall 18 in the area bounded by the partitions 24 and 34 and the end wall 20.
THE CASSETTE
As best seen in FIGS. 4-7, the replaceable, disposable cassette 14 has a generally rectangular body composed of a bottom portion 62 housing a double-acting piston pump assembly, a middle portion 64 housing a valve assembly, and an upper portion 66 housing a fluid inlet 68 for connection to a source of fluid (not shown) and a fluid outlet 70 for connection to a patient. The piston pump assembly comprises a cylindrical bore 72 formed in the bottom portion 62 and having a reciprocating piston assembly 74 therein consisting of two plungers 76 and 78 joined together by a rod 80 having a transverse pin 82 connected thereto and protruding transversely from the bore through respective slots such as 84 formed in both sides of the cassette. When the cassette is inserted downwardly into the base 12, the ends of the pin 82 are guided by respective V-shaped notches, such as 50c (FIG. 2) in each leg 50a, 50b of the yoke 50, into a closely mating rectangular notch 50d at the bottom of each V-shaped notch. This establishes a tight, detachable driving connection between the legs of the reciprocative yoke 50 and the piston rod 80 for driving the piston assembly 74.
The middle portion 64 of the cassette contains two pairs of normally open, deformably closable, resilient tubes 86a, 86b and 88a, 88b, respectively, each pair being interconnected through nipples 87 and conduits 90 and 92, respectively, with a respective fluid chamber 94 or 96 of the piston pump assembly. Tubes 86a and 88b are both connected to the fluid inlet 68, while tubes 86b and 88a are both connected to the fluid outlet 70. Am elongate valve control member 98 is slidably mounted within the middle portion 64 of the cassette so as to move longitudinally with respect to the cassette in a direction parallel to the direction of movement of the piston assembly 74. As best seen in FIGS. 6 and 7, the valve control member 98 has four apertures 98a, 98b, 98c and 98d formed therein, each enclosing a respective one of the deformable tubes. The member 98 also has a portion protruding from one end of the cassette which includes an upwardly-tapered aperture 100 which, upon insertion of the cassette 14 into the base 12, engages an upwardly-protruding pin 102 (FIG. 2) on the L-shaped valve controller 54. The valve control member 98 has two alternative positions as shown in FIGS. 6 and 7, respectively. The position of FIG. 6, caused by the stepper motor 46 retracting the valve controller 54 in a direction toward the motor 46, deformably closes tubes 86a and 88a while permitting tubes 86b and 88b to remain open. Tube 88b exposes chamber 96 to fluid inlet 68 while tube 86b exposes chamber 94 to fluid outlet 70. This position of the valve control member 98 is used when motor 44 is retracting the yoke 50 toward itself, so that fluid is drawn from the fluid source into chamber 96 while it is pumped to the patient from chamber 94 simultaneously and at the same volumetric flow rate. Conversely, the other position of the valve control member 98 is that shown in FIG. 7, caused by motor 46 extending the valve controller 54. This position is used when motor 44 is extending the yoke 50 away from itself, since it opens tube 86a to draw fluid from the fluid source into chamber 94 while also opening tube 88a to pump fluid to the patient from chamber 96, closing the other tubes 86b and 88b. With the directions of the motors 46 and 44 properly synchronized such that valve control member 98 changes position when yoke 50 changes direction, fluid is pumped substantially continuously to the patient from the cassette while fluid is simultaneously drawn into the cassette from the fluid source substantially continuously and at the same volumetric flow rate.
GENERAL DESCRIPTION OF CONTROLS
The control circuitry for the infusion pump is based upon a single chip microcomputer (MCU) such as the Hitachi Model HD630V1 microcomputer. The program within the MCU is started with power-on switching by means of switch 106 (FIG. 8) and maintains and controls all pump functions while providing for user input and function display through the control panel 56. The MCU operates normally in the ultralow-power "sleep" mode (FIG. 10) but can be awakened by "interrupts" produced by one of several components of the control circuitry. First, under normal pump operating conditions, the volumetric rate of fluid infusion set by the user is translated by the MCU 104 into a time interval between the initiations of discrete pump motor drive pulses. This time interval is placed into a timer register, which keeps track of elapsed time regardless of the "sleep" condition of the MCU. When each time interval is completed, the MCU awakens, provides appropriate commands to the pump-motor and visual displays, and goes to sleep again. This cycle is repeated throughout the infusion. In addition, abnormal conditions can interrupt the sleeping state of the MCU. The operator could make changes to the pump control variables (rate, volume to infuse, etc.) by touching the "HALT/DATA" key, the appropriate "SET" key and the appropriate numeric keys, which interrupts the MCU. The input is processed, and the variables modified until the operator requests the pumping operation to resume by a second depression of the "HALT/DATA" key. Other conditions which interrupt the MCU are error states which may occur. These include such conditions as low battery power, external power interruption, air in line, etc.
With reference to FIG. 9, the MCU has a serial I/O port 108 which provides for communication with a peripheral computer device or terminal if desired. This port could be used by a nurses' station to monitor the pump's performance, change settings, record pumping progress, etc., and can be used to "gang" several units infusing several fluids simultaneously.
Pump-Motor Control and Occlusion Sensing
Pump-motor 44 is preferably a noncogging, brushless, permanent magnet rotary motor of three-phase, four-pole design having three Hall effect sensors for monitoring position of the permanent magnet rotor and controlling the solid-state power drive switches (such as Darlington pairs) which commutate the three coil phases. Such motors as well-known, as evidenced for example by U.S. Pat. Nos. 4,130,769 which is incorporated herein by reference. However, in accordance with the special requirements of the present invention, the Hall effect sensors cooperate with the MCU 104 to control the power drive switches in a unique manner.
FIG. 11 depicts six separate rotor position zones per revolution which the three Hall effect sensors are capable of detecting, together with the digital signals (for example "011") which the three Hall sensors produce when the rotor is anywhere within the corresponding zone. FIG. 12 shows the sequence of commutation of the three coil phases A, B, and C as the rotor rotates (e.g. "AB" indicates that phase A is connected to positive voltage and phase B is connected to ground while phase C is connected to neither ). FIG. 13 shows how each of the six rotor position zones is correlated to the particular one of the commutations of FIG. 12 which is effective to move the rotor to the respective zone (e.g., if the rotor is at position "H=011", commutation "AC" will move the rotor to position "H=111"; conversely, if the rotor is at position "H=110", the same commutation "AC" will move the rotor to position "H=111" by reverse rotation). The table of FIG. 14 shows the entire commutation sequence for rotation in either a counterclockwise or clockwise direction, representing a sequence of six motor-control bytes which are stored in the MCU 104 for outputting in sequence at the aforementioned time intervals predetermined by the volumetric flow rate selected by the user, each motor-control byte initiating a motor-driving electrical pulse.
With reference to FIG. 15, each motor-driving pulse is initiated by the commutation information of the motor-control byte, designated by the bits V1, V0, G1, G0, respectively. These are fed to a dual two in--one out selector 110, which actuates one of the three switches 111 for connecting the appropriate one of the three phases A, B, C to positive voltage, and also actuates one of the three switches 113 for connecting the appropriate one of the other phases to ground. The motor-control byte thus written is the one which corresponds to the position zone immediately adjacent to the zone where the rotor is currently located, depending upon the desired direction of rotation. While the foregoing drive pulse-initiating portion of the motor-control byte is being provided to the selector 110, the position command portion of the same byte, designated in FIG. 15 by the bits H2, H1, and H0, is being supplied to a four-bit comparator 112. Simultaneously, the actual Hall effect position sensor readings from the motor 44 are also being supplied to the comparator 112. When the motor-control byte is first written and the drive pulse initiated, the commanded position and actual position will not be equal, and the comparator 112 will emit a low signal on line 114 which is necessary to enable the selector 110. However, as soon as the rotor has moved to the commanded position as a result of the drive pulse, the commanded position and actual position sensed by the comparator 112 will be equal, causing the signal in line 114 to go high, thus disabling the selector 110 and deactivating the power drive switches 111 and 113. Thus, although the motor drive pulses are initiated on a time interval basis, they are terminated on a position basis in response to the advancement of the rotor beyond a predetermined position (i.e., into a new position zone) after the initiation of the pulse.
Should the rotor, after initiation of a pulse, fail to attain the commanded position zone or if, having attained it, the rotor regresses from such zone, the output of the comparator 112 on line 114 will be low, enabling the selector 110 to drive the motor 44 toward the commanded position zone. Thus, the system automatically opposes any regression of the rotor, helping to ensure advancement of the motor especially under high load conditions. If the rotor cannot attain the commanded position zone, the MCU detects this condition by the absence of a high signal from the comparator 112 as sensed on line 116, in response to which the MCU, at the next pulse initiation time, writes the same motor-control byte previously written rather than the next one in the commutation sequence. The MCU counts the number of times this error condition occurs per cc of output fluid, and transmits an error signal in response to the error count exceeding a predetermined number.
The logic flow diagram by which the MCU 104 starts and controls the pump-motor 44 is shown in FIG. 16. To start the motor, the aforementioned error count is initialized to zero, and the present position of the motor is determined in the following manner. Starting at the top of the motor-control byte table of FIG. 14, the commutation information in the byte is masked off and the byte is then written. Since all commutation information is now zero, no power or ground can be connected to any phase. The Hall effect sensors feed actual rotor position to the comparator 112 where it is compared with the position command information in the motor-control byte. If they are unequal, the next motor-control byte in the table is written, and so forth until comparator 112 senses equality, at which time the signal in line 116 goes high establishing the starting point for the commutation sequence. Motor direction is determined by the location of the valve controller 54, as sensed by the closure of one of two limit switches 118 and 120 (FIGS. 2 and 15) or, alternatively, by Hall effect sensors (not shown) within the linear actuator valve motor 46. This information determines in which direction to initiate the commutation sequence. The next motor-control byte in the appropriate direction is written to initiate a motor-drive pulse and rotate the motor. When such drive pulse is terminated depends on whether the rotor has attained the commanded position zone as determined by the comparator 112 in accordance with the previous discussion.
At the end of an interval of time predetermined by the operator's selection of volumetric flow rate, the MCU reads the comparator's output signal on line 116 to determine whether or not the rotor has moved to the commanded position zone. If the signal on line 116 is low, indicating that the commanded position was not attained, the MCU increments the error count and determines whether the count has reached a predetermined maximum count. If not, the same motor-control byte previously written is rewritten at the end of the next time interval. But, if the maximum count has been reached, the MCU transmits an error signal which indicates that the average rate of movement of the motor 44 has been to slow. The error signal may disable the pump and/or actuate an alarm (not shown) mounted in the base 12, and/or write a message to a remote monitor which may be connected to the MCU.
Conversely, if a high signal on line 116 indicates that the commanded position zone has been attained, variables are updated to track progress of the infusion, and the next motor-control byte in the sequence is written. One of the updated variables is the cc-step count which signals the completion of each cc infused. After the infusion of each cc, the error count is cleared so that it can begin again. This feature makes the error count dependent upon the volume of fluid infused, providing a constant error tolerance per cc, as opposed to a variable error tolerance dependent upon motor speed.
When the yoke 50 reaches the end of its stroke in either direction, as indicated by its engagement with one of a pair of limit switches 122 and 124 (FIGS. 2 and 15), the MCU senses closure of the respective switch and actuates valve motor 46 through switch 126 to move the valve control member 98 rapidly it its opposite position for the return stroke of the piston assembly 74. The fluid is thus pumped continuously until the preset total volume to be pumped is reached, or until some error condition interrupts pumping.
Variably controllable output pressure of the pump is made possible by an amplifier 128 inserted in the main power line to the motor drive switches 111. The amplifier 128 variably regulates the time-averaged electrical current in response to a conventional digital-to-analog converter 130 which receives commands from the MCU 104 in response to the pressure setting entered by the user on the control panel 56, as previously described. The output torque of the pump-motor 44, and thus the output pressure of the fluid, is directly proportional to the time-averaged drive current as thus controlled, permitting adjustment of the fluid output pressure by the operator to compensate for excessive error counts due to external loading variables.
The bit indicated as "Hor" in FIG. 15 is a rotor position override, or "masking," bit capable of preventing the comparator 112 from outputting a high signal disabling the dual selector 110, regardless of rotor position. This bit can be used in high-speed applications, such as purging air from the system, where disabling of the selector 110 to terminate drive pulses is undesirable.
The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof, it being recognized that the scope of the invention is defined and limited only by the claims which follow. | 4y
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority from U.S. Provisional Ser. No. 61/570,086, filed Dec. 13, 2011.
FIELD
The present disclosure relates to the field of hybrid electric vehicles (HEV) and battery electric vehicles (BEV), and more particularly to an electric power dissipation system and method for hybrid electric and battery electric vehicles.
BACKGROUND
Permanent magnet synchronous motors (PMSM) are widely used in hybrid electric vehicles and battery electric vehicles. Among the permanent magnet synchronous motors, interior permanent magnet (IPM) motors are the most commonly used motors for HEV/BEV applications due to their high power density, high efficiency and wide speed range.
When a hybrid electric vehicle or battery electric vehicle is in an electric mode (i.e., the mode when it is only running the electric motor without the assistance of an internal combustion engine), the vehicle needs to give the driver similar drive performance as compared to conventional vehicles that only use an internal combustion engine. One of the desired features for hybrid electric and battery electric vehicles is to have a coast-down performance similar to that of conventional vehicles. This requires the electric motor to provide certain brake torque to the vehicle when the accelerator pedal is released. In other words, the mechanical power is converted to electric power and fed back to the battery. This is also called coast-down regenerative braking. Regenerative braking is an energy recovery mechanism that slows down a vehicle by converting its kinetic energy into another form—in the case of hybrid electric and battery electric vehicles, the kinetic energy is converted into electrical energy. In conventional braking systems (i.e., for internal combustion engine vehicles), by contrast, excess kinetic energy is converted into heat by friction in the brake linings; therefore, the excess energy is wasted in these vehicles. For hybrid electric and battery electric vehicles, however, the excess energy can be stored in a battery or bank of capacitors for later use.
However, under certain conditions, (e.g., when the state of charge (SOC) of the battery is high or the battery temperature is hot/cold), regeneration current is not allowed back to the battery. Battery state of charge is the equivalent of a fuel gauge for the battery in a hybrid electric or battery electric vehicle, which measures how fully charged the battery is. Thus, when the state of charge of the battery is high or the battery temperature is hot/cold, the amount of power that can be accepted by the battery is met or exceeded. As such, there is the possibility of detrimental effects to the battery if more power is fed back to it.
Under certain conditions such as e.g., when the SOC is nearly full or the battery temperature is high, if coast-down regeneration is not allowed, the electric motor suddenly has to remove all of its braking torque to prevent the current (i.e., energy converted from kinetic energy) from charging the battery. This affects the smoothness of the driving experience as perceived and felt by the driver. This will give the driver inconsistent drive performance when the above conditions exist compared to when they do not. Thus, there is a need to allow regenerative braking in hybrid electric and battery electric vehicles under all circumstances even when the regeneration current cannot be fed back to the battery.
SUMMARY
In one form, the present disclosure provides a motor control apparatus for a hybrid electric vehicle comprising an electric motor. The apparatus comprises a battery control module coupled to a battery and configured to monitor and detect a state of the battery; and a motor control unit coupled to the battery and the battery control module, said motor control unit being configured to selects one of a normal motor control operation, a power dissipation motor control operation, or a discharge operation based on the state of the battery received from the battery control module. During the power dissipation motor control operation, power from brake torque is dissipated in stator windings of the electric motor.
The present disclosure also provides a method of operating an electric motor of a hybrid electric vehicle. The method comprises detecting, at a battery control module, a state of an electric battery within the vehicle; and selecting, at a mode control unit, one of a normal operation, power dissipation operation, or discharge operation of the electric motor based on the detected state of the battery. During the power dissipation operation, power from brake torque is dissipated in stator windings of the electric motor.
As disclosed herein, the state of the battery includes a state of charge of the battery, a battery temperature, and/or a fault condition. The motor control unit selects the normal motor control operation if the state of charge of the battery is below a predetermined value and selects the power dissipation motor control operation if the state of charge of the battery is above a predetermined value.
Further areas of applicability of the present disclosure will become apparent from the detailed description and claims provided hereinafter. It should be understood that the detailed description, including disclosed embodiments and drawings, are merely exemplary in nature intended for purposes of illustration only and are not intended to limit the scope of the invention, its application or use. Thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates an interior permanent magnet operating plane;
FIG. 2 illustrates a schematic of the electrical system of a hybrid electric vehicle;
FIG. 3 illustrates a block diagram of the control process having the electric power dissipation process in accordance with the present disclosure; and
FIG. 4 illustrates a block diagram of the control process having the electric power dissipation process in accordance with another embodiment of the present disclosure.
DETAILED DESCRIPTION
Described herein is a mechanism to maintain consistent drive performance for hybrid electric and battery electric vehicles (as compared to conventional vehicles with internal combustion engines) under constrained conditions. The disclosed mechanism provides a path to dissipate power generated by braking torque without generating any power back to the battery. In addition, under certain conditions, the mechanism can even draw current from the battery while still producing the desired electric motor braking torque. In some instances, it is desirable to have current drawn from the battery to discharge it (to prevent a battery overcharge condition) or to warm it up (i.e., if the battery charge power limit is low because it is cold) so that the battery can provide full power more quickly.
Embodiments described herein dissipate the power generated by braking torque through the electric motor's stator windings, while the motor is providing the required electric motor braking torque and without charging the battery. In the synchronous frame, the steady-state voltage equation of an interior permanent magnet motor can be expressed as:
V ds =R s i ds −ω r L q i qs (1)
V qs =R s i qs +ω r ( L d i ds +λ PM □) (2)
Where v as , v qs , i ds and i qs are the motor currents and voltages in the d-q reference frame, ω r is the rotor electrical frequency, L d and L q are the stator d- and q-axis inductances, R s is the stator resistance, and λ PM is the permanent-magnet flux linkage.
The motor torque output is given by:
T em =(3 P/ 2)(λ PM i q +( L d −L q ) i d i q ) (3)
Where P is the number of pairs of poles of the motor.
The motor current is limited by i max :
i ds 2 +i qs 2 <i max 2 (4)
With the motor model defined in equations (1) and (2) for a given torque, T em , the minimum current is the shortest distance from the torque curve to the origin, i=√{square root over (i ds 2 +i qs 2 )}. For a given torque T, the minimum current is the shortest distance from the torque curve to the origin in the current d-q coordinate and the Maximum Torque Per Ampere (MTPA) curve can be obtained as:
i
d
=
I
PM
2
(
L
q
-
L
d
)
-
λ
PM
2
4
(
L
d
-
L
q
)
2
+
i
qs
2
(
5
)
Referring to FIG. 1 , the maximum torque per ampere (MTPA) curve, maximum torque per volt (MTPV) curve, current limit circle, I limit, and torque curves are plotted. The voltage ellipses for the motors (1) and (2) are also plotted. For any given torque, DC bus voltage, and motor speed, there exists a torque curve and a voltage ellipse curve as shown, for example, in FIG. 1 . The torque curve intercepts with the voltage ellipse and the boundaries such as the MTPA curve, MTPV curve and current limit circle. A unique set of optimal reference currents i d and i q within the optimal operational plane can be determined.
For a given torque command, the motor current i d and i q can be chosen at any point along the torque curve. However, the optimal (i.e., minimum) motor current is at the intersection between the MTPA and the torque curve as shown in FIG. 1 . To maintain the same motor torque output, it has been determined that more current will dissipate more power, or losses, in the motor stator windings. Thus, the present disclosure aims to maintain the same torque output with the more possible current (note: if maximum possible power needs to be dissipated, then the highest possible current i max on the same torque curve will be needed). The total power dissipation in the motor stator winding is:
P= 3 R s ( i ds 2 +i qs 2 ) (6)
And the power from the battery, or DC power supply is:
P=V dc I dc (7)
The maximum power dissipation is limited by the motor current limit, i max (i.e., the current limit circle radius). For a given torque command, the maximum power dissipation current command is at the intersection of the current limit circle and the torque curve as shown in FIG. 1 . The intersection point (i d — max , i q — max ) is determined by equations (3) and (4) set forth above.
FIG. 2 illustrates an electrical system overview of a hybrid electric vehicle. The electrical system includes a battery 10 , which is an electric battery, connected to a battery control module 20 and a power electronics and motor control unit 30 . The battery control module 20 monitors and controls the functions of the battery 10 . For example, the battery control module 20 can detect the state of charge of the battery and/or the battery's temperature. The power electronics and motor control unit 30 contains motor control process 40 (described below) and is also connected to an electric motor 50 , which can be for example, an interior permanent magnet motor.
FIG. 3 illustrates an example motor control process 40 having a power dissipation process 60 in accordance with the present disclosure. In a desired embodiment, the process 40 is implemented in software operated by control unit 30 or other processor. The power dissipation process 60 includes, among other processing, a current regulator process 62 and i q process 64 . The current regulator process 62 (which can be, for example, a proportional integral regulator) tries to regulate the DC current feedback to the current reference value. The DC bus voltage V dc and current feedbacks i ds are sensed and the DC power consumption P can be calculated by equation (7). Depending on the i dc — ref value, either zero or a positive value for more power consumption by the motor and other loads in the system, the DC current feedback is compared with the reference value and fed to the current regulator. The “other loads” could be, for example, a DC/DC converter (e.g., 300V to 12V), heater or cooler, and all other auxiliary loads that are connected to the high voltage DC bus. The auxiliary loads can be factored into the determination by use of load reference models or look-up tables for a more accurate calculation. The commanded i d is calculated by equation (6) and is compensated by the output of the current regulator process 62 . The commanded i d can also be obtained by using look-up tables that can take motor/vehicle parameter uncertainty and other vehicle power loads into consideration to get better accuracy of the power consumption.
The i d , i q calculation for normal motor torque control (i.e., when power dissipation mode is not needed) is performed in process 42 . It should be appreciated that the process 42 can also be implemented by using a look-up table 42 ′ (as shown in FIG. 4 ) with calibration entries to accommodate the uncertainty of the motor and other loads in the vehicle; this may allow for a more accurate calculation. The motor stator resistance value is also compensated for by stator temperature feedback. In other words, the motor stator resistance is compensated for by stator temperature feedback. Thus, for more accurate calculations, a sensor may be used to sense the temperature and calculate the resistance based on that temperature. For a given i d and commanded torque, the commanded i q is calculated by equation (3). I d and i q are limited by the intersection point of torque and current limit circle (i d — max , i q — max ). Depending on whether the drive system is in the power dissipation mode or not, a motor control process 44 will take input either the normal current command or the disclosed novel power dissipation current command.
According to the present disclosure, the battery control module 20 monitors the state of the battery 10 (e.g., SOC or temperature of the battery). Depending on the state of the battery, the motor control process 40 will switch the operation of the motor control process 44 to use either use normal motor control (i.e., under a normal battery condition) or the disclosed power dissipation motor control process in accordance with the disclosed principles (i.e., under a constrained battery condition). By dissipating the power in the motor stator windings, the vehicle can maintain the coast-down braking torque without charging the battery, which can improve vehicle drive performance when power limits are constrained. The motor control process can not only produce zero charging current to the battery, it can also follow a prescribed commanded DC discharge current to dissipate more power from the battery. This accelerates the warm-up process of the battery or prevent a battery overcharge condition.
The disclosed embodiments can also be used for transient driveline control when the battery charge power is constrained. For example, for active driveline damping control, the battery is often used as a buffer to sink and source electric motor power to damp driveline oscillations. If the battery charge power is compromised, the damping control cannot function properly. With the power dissipation control process disclosed herein, a portion of the damping control can be maintained even under adverse conditions. | 4y
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BACKGROUND OF THE INVENTION
1. Field of Invention
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.
2. Related Art
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.
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
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.
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.
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.
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.
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.
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.
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.
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.
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.
Another aspect of the invention are methods of making a locked pair of shafts, one method of the invention comprising:
(a) measuring axial shaft movement of first and second shafts during operation using a standard coupling; (b) selecting a coupling member to limit the axial shaft movement; and (c) installing the coupling member to limit the axial shaft movement.
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.
Yet another aspect of the invention are methods of pumping fluids, one method comprising:
(a) determining a pumping requirement for transferring a fluid; (b) selecting a pump having a pump shaft, and a driver having a driver shaft; (c) coupling the pump shaft and driver shaft axially using a coupling member of the invention; and (d) pumping the fluid using the pump to meet the pumping requirement.
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.
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
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:
FIGS. 1-3 illustrate schematically in side-elevation, partial cross-sectional views of a prior art horizontal pumping system, and certain problems therewith; and
FIGS. 4-19 illustrate schematically in side elevation, partial cross-sectional views, of non-limiting embodiments of apparatus, systems, and methods of the invention.
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
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.
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.
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.
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.
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 ).
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 .
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 .
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, H 2 S, 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.
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 .
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 .
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.
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 .
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.
FIG. 11 illustrates another apparatus and system embodiment 900 of the invention, which may be explained as a minor 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 .
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.
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 .
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 .
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 , 15 C, 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.
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.
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.
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 .
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.
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.
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.
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.
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.
Typical uses of apparatus and systems of the invention will be in downhole and surface fluid transfer applications.
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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BACKGROUND OF THE INVENTION
[0001] The present invention pertains to an integrated oxygen fueled combustion and pollution control system. More particularly, the present invention pertains to an oxy-fueled combustion system having integrated pollution control to effectively reduce, to near zero, emissions from combustion sources.
[0002] Oxy-fueled combustion systems are known in the art. Such systems use essentially pure oxygen for combustion with fuel in near stoichiometric proportions and at high flame temperatures for high efficiency energy production. Oxy-fuel systems are used in boilers to produce steam for electrical generation and in industrial settings, such as in aluminum recycling to melt aluminum for recasting. It is also contemplated that oxy-fueled combustion can be used for waste incineration as well as other industrial and environmental applications. Oxy-fuel technology and uses for this technology are disclosed in Gross, U.S. Pat. Nos. 6,436,337, 6,596,220, 6,797,228 and 6,818,176, all of which are commonly owned with the present application and are incorporated herein by reference.
[0003] Advantageously, because oxy-fuel combustion uses oxygen rather than air as an oxygen source, there is concomitant reduction in flue gas produced. In addition, combustion is carried out so that the NOx combustion products are near zero and are due almost exclusively to fuel-borne nitrogen. That is, because oxygen rather than air is used as an oxygen source, there is less mass flow and no nitrogen to contribute to the formation of NOx.
[0004] Although oxy-fuel combustion provides fuel efficiency and reduced emission energy generation, there is still a fairly substantial amount of emissions that are produced during the combustion process. In addition, because the volume of gas is less, due to the use of oxygen instead of air, the concentration of other pollutants is higher. For example, the mass of SOx and particulate matter will not change, however, the concentration will increase because of the reduced overall volume.
[0005] Pollution control or removal systems are known in the art. These systems can, for example, use intimate contact between the flue gases and downstream process equipment such as precipitators and scrubbers to remove particulate matter, sulfur containing compounds and mercury containing compounds. Other systems use serial compression stripping of pollutants to remove pollutants and recover energy from the flue gas stream. Such a system is disclosed in Ochs, U.S. Pat. No. 6,898,936, incorporated herein by reference.
[0006] Accordingly, there is a need for a combustion system that produces low flue gas volume with integrated pollution removal. Desirably, such a system takes advantage of known combustion and pollution control systems to provide fuel efficient energy production in conjunction with reduced pollutant production and capture of the remaining pollutants that are produced.
BRIEF SUMMARY OF THE INVENTION
[0007] An integrated oxygen fueled combustion system and pollutant removal system, reduces flue gas volumes, eliminates NOx and capture condensable gases. The system includes a combustion system having a furnace with at least one burner that is configured to substantially prevent the introduction of air. An oxygen supply supplies oxygen at a predetermine purity greater than 21 percent and a carbon based fuel supply supplies a carbon based fuel. Oxygen and fuel are fed into the furnace in controlled proportion to each other. Combustion is controlled to produce a flame temperature in excess of 3000 degrees F. and a flue gas stream containing CO2 and other gases and is substantially void of non-fuel borne nitrogen containing combustion produced gaseous compounds.
[0008] The pollutant removal system includes at least one direct contact heat exchanger for bringing the flue gas into intimated contact with a cooling liquid, preferably water, to produce a pollutant-laden liquid stream and a stripped flue gas stream. The system includes at least one compressor for receiving and compressing the stripped flue gas stream.
[0009] Preferably, the system includes a series of heat exchangers and compressors to cool and compress the flue gas. The flue gas can be cooled and compressed to and the stripped flue gas stream can separated into non-condensable gases and condensable gases. The condensable gases, in large part CO2, are condensed into a substantially liquid state and can be sequestered. The CO2 can be recirculated, in part, to carry a solid fuel such as coal into the furnace.
[0010] A method oxy-fuel combustion integrated with pollutant removal includes providing a furnace having at least one burner, and configured to substantially prevent the introduction of air, providing an oxygen supply for supplying oxygen at a predetermine purity greater than 21 percent and providing a carbon based fuel supply for supplying a carbon based fuel.
[0011] Either or both of the oxygen and carbon based fuel are limited to less than 5 percent over the stoichiometric proportion and combustion is controlled to produce a flame temperature in excess of 3000 degrees F. and a flue gas stream containing CO2 and other gases and substantially void of non-fuel borne nitrogen containing combustion produced gaseous compounds.
[0012] The pollutant removal system is provided which includes a direct contact heat exchanger in serial arrangement with a compressor. The flue gas is brought into intimated contact with a cooling liquid, preferably water, in the heat exchanger to produce a pollutant-laden liquid stream and a stripped flue gas stream. The stripped flue gas stream is fed into the compressor to compress the stripped flue gas stream.
[0013] In a preferred method, the steps of cooling the stripped flue gas stream and compressing the cooled stripped flue gas stream are carried out as well as sequestering the compressed cooled stripped flue gas stream.
[0014] These and other features and advantages of the present invention will be apparent from the following detailed description, in conjunction with the appended claims.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0015] The benefits and advantages of the present invention will become more readily apparent to those of ordinary skill in the relevant art after reviewing the following detailed description and accompanying drawings, wherein:
[0016] FIG. 1 is flow diagram of an integrated oxy-fuel combustion and pollutant removal system that was assembled for testing the principles of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0017] While the present invention is susceptible of embodiment in various forms, there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiment illustrated. It should be further understood that the title of this section of this specification, namely, “Detailed Description Of The Invention”, relates to a requirement of the United States Patent Office, and does not imply, nor should be inferred to limit the subject matter disclosed herein.
[0018] As discussed in the aforementioned patents to Gross, an oxy-fuel combustion system uses essentially pure oxygen, in combination with a fuel source to produce heat, by flame production (i.e., combustion), in an efficient, environmentally non-adverse manner. Oxygen, which is supplied by an oxidizing agent, in concentrations of about 85 percent to about 99+ percent can be used, however, it is preferable to have oxygen concentration (i.e., oxygen supply purity) as high as possible.
[0019] In such a system, high-purity oxygen is fed, along with the fuel source in stoichiometric proportions, into a burner in a furnace. The oxygen and fuel is ignited to release the energy stored in the fuel. For purposes of the present disclosure, reference to furnace is to be broadly interpreted to include any industrial or commercial heat generator that combusts fossil (carbon-based) fuel. For example, water-tube-walled boilers for electrical power generation, as well as direct fired furnaces for industrial applications are contemplated to use the oxy-fueled combustion system. In a preferred system, oxygen concentration or purity is as high as practicable to reduce green-house gas production.
[0020] It is contemplated that essentially any fuel source can be used. For example, oxygen can be fed along with natural gas, for combustion in a furnace. Other fuel sources contemplated include oils including refined as well as waste oils, wood, coal, coal dust, refuse (garbage waste), animal wastes and products and the like. Those skilled in the art will recognize the myriad fuel sources that can be used with the present oxy-fuel system.
[0021] Compared to conventional combustion processes which use air as an oxidizing agent to supply oxygen, rather than essentially pure oxygen, for combustion, the oxy-fuel system has an overall flow throughput that is greatly reduced. The oxygen component of air (about 21 percent) is used in combustion, while the remaining components (essentially nitrogen) are heated in and exhausted from the furnace. Moreover, the present process uses oxygen in a stoichiometric proportion to the fuel. That is, only enough oxygen is fed in proportion to the fuel to assure complete combustion of the fuel. Thus, no “excess” oxygen is fed into the combustion system.
[0022] Many advantages and benefits are achieved using the oxy-fuel combustion system. Aside from increased efficiency (or conversely reduced fuel consumption to produce an equivalent amount of power), because of the reduced input of gas, there is a dramatic decrease in the volume of flue gas. Based on the difference between using air which is 21 percent oxygen and pure oxygen, the volumetric flow rate is about one-fifth (1/5) using an oxy-fuel combustion system, compared to a conventional air-fed combustion system. In addition, because there is no energy absorbed by non-combustion related materials (e.g., excess oxygen or nitrogen), more energy is available for the underlying process.
[0023] Advantageously, the reduced gas volume (and thus flue gas volume) also increases the residence time of the gases in the furnace or boiler to provide additional opportunity for heat transfer.
[0024] In that the overall flue gas volume is so greatly reduced, highly efficient downstream processing that would otherwise not be available or would be impractical can now be used in large scale industrial and power generation settings.
[0025] Accordingly, the present invention uses oxy-fuel combustion in conjunction with the removal of multiple pollutants through the integrated condensation of H2O and CO2 with entrainment of particulates and dissolution and condensation of other pollutants including SO2. Such a pollutant removal system and method is disclosed in the aforementioned patent to Ochs et al.
[0026] Consolidating the removal of pollutants into one process has the potential to reduce costs and reduce power requirements for operation of such a system. Non-condensable combustion products including oxygen and argon may be present in combustion products. Although the oxy-fuel combustion system is operated at or very near stoichiometry (preferably within 5 percent of stoichiometry), oxygen may be present in the flue gas. Argon can come from the air separation process (remaining in the produced oxygen). Some relatively small amounts of nitrogen may also be present as fuel-borne or as air in-leakage into the underlying process equipment.
[0027] Condensable vapors such as H2O, CO2, SOx, and although minimal, NOx, are produced in the combustion process and are the targets for condensation. When referring to combustion products in this invention it is assumed that these condensable vapors and non-condensable gases are present as well as particulates and other pollutants.
[0028] The pollutant control portion of the system can also accomplish remediation and recovery of energy from combustion products from a fossil fuel power plant having a fossil fuel combustion chamber (e.g., a boiler, furnace, combustion turbine or the like), a compressor, a turbine, a heat exchanger, and a source of oxygen (which could be an air separation unit). Those skilled in the art will understand and appreciate that reference to, for example, a compressor, includes more than one compressor.
[0029] The fossil fuel power plant combustion products can include non-condensable gases such as oxygen and argon; condensable vapors such as water vapor and acid gases such as SOX and (again, although minimal, NOX); and CO2 and pollutants such as particulates and mercury. The process of pollutant removal and sequestration, includes changing the temperature and/or pressure of the combustion products by cooling and/or compressing the combustion products to a temperature/pressure combination below the dew point of some or all of the condensable vapors.
[0030] This process is can out to condense liquid having some acid gases dissolved and/or entrained therein and/or directly condensing the acid gases (such as CO2 and SO2) from the combustion products. It is carried out further to dissolve some of the pollutants thus recovering the combustion products. Dissolve in the context of this disclosure means to entrain and/or dissolve.
[0031] This process is repeated through one or more of cooling and/or compressing steps with condensation and separation of condensable vapors and acid gases. The recovery of heat in the form of either latent and/or sensible heat cab also be accomplished. The condensation reduces the energy required for continued compression by reducing mass and temperature, until the partially remediated flue gas is CO2, SO2, and H2O poor. Thereafter the remaining flue gases are sent to an exhaust.
[0032] The fossil fuel can be any of those discussed above. In certain instances, the pollutants will include fine particulate matter and/or heavy metals such as mercury other metals such as vanadium.
[0033] The present invention also relates to a method of applying energy saving techniques, during flue gas recirculation and pollutant removal, such that power generation systems can improve substantially in efficiency. For example, in the case of a subcritical pulverized coal (PC) system without energy recovery, the performance can drop from 38.3% thermal efficiency (for a modern system without CO2 removal) to as low as 20.0% (for the system with CO2 removal and no energy recovery). A system according to one embodiment of the present invention can perform at 29.6% (with CO2 removal) when energy recovery is included in the model design. it is anticipated that better efficiencies will be achieved. The present oxy-fuel combustion with integrated pollution control is applicable to new construction, repowering, and retrofits.
[0034] In an exemplary system using the present oxy-fuel and IPR process, flue gases as described in the table below are predicted. The flue gases will exit from the combustion region or furnace area, where they would pass through a cyclone, bag house or electrostatic precipitator for gross particulate removal. The combustion gas then passes through a direct contact heat exchanger (DCHX). In this unit the flue gases come into contact with a cooler liquid. This cooling step allows the vapors to condense. The step also allows for dissolving the entrained soluble pollutants and fine particles.
[0035] The gases exiting the first column are now cleaner and substantially pollutant free. These gases are compressed and can proceed into a successive DCHX and compression step. A final compression and heat exchange step is used to separate the oxygen, argon, and nitrogen (minimal) from the CO2. Also a mercury trap is used to remove gaseous mercury before release to atmosphere.
[0036] The table below shows the expected results as a comparison of the present oxy-fuel combustion and IPR system to a conventional air fueled combustion process. As the results show, the volume of flue gas at the outset, is less in the oxy-fuel combustion system by virtue of the elimination of nitrogen from the input stream. In the present system, the IPR serves to further reduce the volume and gas flow through successive compression and cooling stages. As the flue gases progress through the combined processes the final product is captured CO2 for sequestration.
[0000]
TABLE 1
A COMPARISON OF THE PROPERTIES AND COMPOSITIONS
OF IPR-TREATED OXY-FUEL COMBUSTION PRODUCTS WITH
THOSE FROM A CONVENTIONAL COAL FIRED BOILER
Conventional
after
Oxyfuel
After 1 st
After 2 nd
After 3rd
economizer
exhaust
compression
compression
compression
Gas Flow (kg/hr)
1,716,395
686,985
364,367
354,854
353,630
Vol flow (m 3 /hr)
1,932,442
826,995
72,623
15,944
661
Inlet Pressure
14.62
15.51
62
264
1,500
(psia)
Inlet Temp. (°F.)
270
800
342
323
88.2
Density (kg/m 3 )
0.8882
0.8307
5.02
22.26
534.61
H 2 O (fraction)
0.0832
0.33222
0.0695
0.00994
0.0004
Ar (fraction)
0.0088
0.01152
0.0163
0.01730
0.0175
CO 2 (fraction)
0.1368
0.61309
0.8662
0.92161
0.9305
N 2 (fraction)
0.7342
0.00904
0.0128
0.01359
0.0137
O 2 (fraction)
0.0350
0.02499
0.0353
0.03755
0.0379
SO 2 (fraction)
0.0020
0.00913
0.0000
0.00000
0.0000
[0037] As can be seen from the data of Table 1, the volume of the combustion products has dropped significantly as a result of the successive compressing and cooling stages. The result is a capture of CO2 and subsequent sequestration, which is the ultimate goal. The CO2 thus resulting can be stored or used in, for example, a commercial or industrial application.
[0038] A test system 10 was constructed to determine the actual results vis-à-vis oxy-fuel combustion in conjunction with CO2 sequestration and pollutant removal. A schematic of the test system is illustrated in FIG. 1 . The system 10 includes an oxy-fueled combustor 12 having a coal feed 14 (with CO2 as the carrier gas 16 ), and an oxygen feed 18 . Coal was fed at a rate of 27 lbs per hour (pph), carried by CO2 at a rate of 40 pph, and oxygen at a rate of 52 pph. In that the system 10 was a test system rather than a commercial or industrial system (for example, a commercial boiler for electrical generation), the combustor 12 was cooled with cooling water to serve as an energy/heat sink.
[0039] The combustor exhaust 20 flowed to a cyclone/bag house 22 at which ash (as at 24 ) was removed at a rate of about 1 pph. Following ash removal 24 , about 118 pph of combustion gases remained in the flue gas stream 26 at an exit temperature that was less than about 300° F.
[0040] The remaining flue gases 26 were then fed to a direct contact heat exchanger 28 (the first heat exchanger). Water (indicated at 30 ) was sprayed directly into the hot flue gas stream 26 . The cooling water condensed some of the hot water vapor and further removed the soluble pollutants and entrained particulate matter (see discharge at 32 ). About 13 pph of water vapor was condensed in the first heat exchanger 28 —the flue gases that remained 34 were present at a rate of about 105 pph.
[0041] Following exit from the first heat exchanger 28 , the remaining gases 34 were fed into a first, a low pressure compressor 36 , (at an inlet pressure of about atmospheric) and exited the compressor 36 at a pressure of about 175 lbs per square inch gauge (psig). As a result of the compression stage, the temperature of the gases 38 increased. The remaining flue gases were then fed into a second direct contact heat exchanger 40 where they were brought into intimate contact with a cooling water stream as at 42 . The exiting stream 44 released about an additional 4 pph of water and thus had an exiting exhaust/flue gas 44 flow rate of about 101 pph.
[0042] Following the second heat exchanger 40 , the gases 44 were further compressed to about 250 psig at a second compressor 46 . Although the second compression stage resulted in a temperature increase, it was determined during testing that a third heat exchange step was not necessary. It will be appreciated that in larger scale operation, however, such additional heat exchange/cooling stages may be necessary.
[0043] A third compression stage, at a third compressor 48 was then carried out on the remaining flue gases 50 to increase the pressure of the exiting gas stream 52 to about 680 psig. Again, it was determined that although the temperature of the gases increased, active or direct cooling was not necessary in that losses to ambient through the piping system carrying the gases were sufficient to reduce the temperature of the gases.
[0044] A final compression, at a final compressor 52 , of the gases was carried out to increase the pressure of the gases to about 2000 psig. Following the final compression stage, the remaining gases 56 were fed into a heat exchanger 58 , the final heat exchanger, in which the temperature of the stream 56 was reduced to below the dew point of the of the gases and as a result, condensation of the gases commenced. The condensate (as at 60 ), which was principally liquefied CO2 (at a rate of 80 pph), was extracted and sequestered. In the present case, the CO2 was bottled, and retained.
[0045] The non-condensable gases (as at 62 ), which included a small amount of CO2, were passed through a mercury filter 64 and subsequently bled into an accumulator 66 . The accumulator 66 provided flexibility in control of the system flow rate. The exhaust 68 from the accumulator 66 was discharged to the atmosphere. The flow rate from the accumulator 66 , normalized to steady state from the overall system, was about 21 pph.
[0046] It will be appreciated by those skilled in the art that the above-presented exemplary system 10 was for testing and verification purposes and that the number and position of the compression and cooling stages can and likely will be changed to accommodate a particular desired design and/or result. In addition, various chemical injection points 70 , filters 72 , bypasses 74 and the like may also be incorporated into the system 10 and, accordingly, all such changes are within the scope and spirit of the present invention.
[0047] The projected fuel savings and other increased efficiencies of the present oxy-fuel combustion system with IPR are such that the cost of this combined process is anticipated to be competitive with current combustion technologies. Additionally, the prospect of new regulatory requirements are causing power plant designers to revisit the conventional approaches used to remove pollutants which would only serve to improve the economics behind this approach.
[0048] It will be appreciated that the use of oxy-fueled combustion systems with IPR in many industrial and power generating applications can provide reduced fuel consumption with equivalent power output or heat generation. Reduced fuel consumption, along with efficient use of the fuel (i.e., efficient combustion) and integrated R provides significant reductions in overall operating costs, and reduced and sequestered emissions of other exhaust/flue gases.
[0049] Due to the variety of industrial fuels that can be used, such as coal, natural gas, various oils (heating and waste oil), wood and other recycled wastes, along with the various methods, current and proposed, to generate oxygen, those skilled in the art will recognize the enormous potential, vis-à-vis commercial and industrial applicability, of the present combustion system. Fuel selection can be made based upon availability, economic factors and environmental concerns. Thus, no one fuel is specified; rather a myriad, and in fact, all carbon based fuels are compatible with the present system. Accordingly, the particulate removal stages of the integrated IPR system may vary.
[0050] As to the supply of oxygen for the oxy-fueled burners (combustion system), there are many acceptable technologies for producing oxygen at high purity levels, such as cryogenics, membrane systems, absorption units, hydrolysis and the like. All such fuel uses and oxygen supplies are within the scope of the present invention.
[0051] In general, the use of oxygen fuel fired combustion over current or traditional air fuel systems offers significant advantages in many areas. First is the ability to run at precise stoichiometric levels without the hindrance of nitrogen in the combustion envelope. This allows for greater efficiency of the fuel usage, while greatly reducing the NOx levels in the burn application. Significantly, less fuel is required to achieve the same levels of energy output, which in turn, reduces the overall operating costs. In using less fuel to render the same power output, a natural reduction in emissions results. Fuel savings and less emissions are but only two of the benefits provided by the present system. In conjunction with the integrated pollutant removal (IPR) system, the present oxy-fuel IPR system provides far greater levels of efficiency and pollution control than known systems.
[0052] It is anticipated that combustors (e.g., boilers) will be designed around oxygen fueled combustion systems with integrated IPR to take full advantage of the benefits of these systems. It is also anticipated that retrofits or modifications to existing equipment will also provide many of these benefits both to the operator (e.g., utility) and to the environment.
[0053] In the present disclosure, the words “a” or “an” are to be taken to include both the singular and the plural. Conversely, any reference to plural items shall, where appropriate, include the singular.
[0054] From the foregoing it will be observed that numerous modifications and variations can be effectuated without departing from the true spirit and scope of the novel concepts of the present invention. It is to be understood that no limitation with respect to the specific embodiments illustrated is intended or should be inferred. The disclosure is intended to cover by the appended claims all such modifications as fall within the scope of the claims. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to collapsible shade structures and specifically to collapsible or folding tents. The shade structure of the present invention provides an integral structure capable of supporting itself to act as a shelter.
2. Description of the Prior Art
Prior art collapsible shade structures have suffered from several drawbacks. One drawback with such collapsible shade structures is the difficulty associated with erecting and stably supporting such structures. Another drawback associated with these prior art collapsible shade structures is that the construction of such structures tend to be complicated, bulky and are therefore troublesome to fold away and to store.
A further drawback of such prior art collapsible shade structures is that the structure itself tends to be weak even after it has been erected, and often requires other means to provide the required structural integrity. An example of such a structure is U.S. Pat. No. 3,990,463, which discloses a flexible and coilable frame member which allows for the structure to be easily collapsed and stored when not in use. The frame member is secured to the fabric of the structure and is held in a "figure-eight" configuration with the cross-over of the figure-eight as the apex of the structure and the loops of the figure-eight extending downwardly therefrom to provide support for the structure. Since the cross-over of the figure-eight frame member can only effectively support two of the side panels, tie members are provided at the lower corners of the structure and are located so as to tension and support the other two side panels. The tie members are therefore required to stabilize the frame and to hold the frame and the remainder of the structure upright because the frame member alone cannot accomplish this.
Another example is U.S. Pat. No. 3,960,161, which discloses a portable structure similar to that described in U.S. Pat. No. 3,990,463, in which the structure is supported by a flexible coilable frame member secured to the fabric. The structure in U.S. Pat. No. 3,960,161 also requires tie members at the lower corners of the structure to provide support and stability in use, and to tension the fabric by pulling downwardly and outwardly from the frame member.
The various existing collapsible shade structures have not been successful in providing a simple structure which is easy to erect and may be folded to a compact size for ease of storage, in which the structure when erected is capable of stably supporting itself. The present invention, therefore, provides for an improvement over the prior art collapsible shade structures and provides a collapsible shade structure with a novel frame structure in which the structure when erected is capable of stably supporting itself, and which also allows the collapsible shade structure to be of simple construction, to be easily erected and easily folded to a compact size to facilitate ease of storage.
SUMMARY OF THE DISCLOSURE
In order to accomplish the objects of the present invention, the collapsible shade structure is made of a plurality of foldable frame members each having a folded and an unfolded orientation. Four or more of such frame members are configured to form an interior space. A fabric material is provided which substantially covers the frame members to form a side panel for each frame member, each side panel assuming the unfolded orientation of its associated frame member. Interconnecting portions of the fabric material form a hinge portion between each frame member. A roof formed from the fabric material interconnects the upper portions of the side panels.
When the structure is to be folded and stored, the side panels and their corresponding frame members may be folded on top of each other about the hinge portions to have the side panels and frame members overlaying each other. The overlying side panels and frame members are then collapsed by twisting and folding to form a plurality of concentric frame members and side panels to substantially reduce the size of the shade structure in the folded orientation.
The collapsible shade structure may be used as a shelter affording a camper, for example, the convenience of a tent which may be easily erected and easily collapsed and folded to a compact arrangement that is a fraction of its unfolded size for easy storage. The materials used are lightweight, and together with its compact size, the tent is very convenient to transport.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects, advantages and features of the invention will become apparent from the detailed description of the preferred embodiments when read in conjunction with the accompanying drawings, in which:
FIG. 1 is a perspective view of the collapsible shade structure having four triangular side panels;
FIG. 2 is a perspective view of the internal frame structure of the collapsible shade structure of FIG. 1;
FIG. 3 is a perspective view partially broken away showing the vent of the collapsible shade structure of FIG. 1 in an open position;
FIG. 4 is a perspective view of the vent of FIG. 3 in a closed position;
FIG. 5 is a cross-sectional side view of the vent of FIG. 3 in an open position;
FIG. 6A represents a perspective view of a roof which may be used with the collapsible shade structure of FIG. 1;
FIGS. 6B-6F illustrate the separate components of the roof of FIG. 6A;
FIG. 7 is a second embodiment of the collapsible shade structure having six side panels;
FIG. 8 is a third embodiment of the collapsible shade structure having five side panels;
FIG. 9 is a fourth embodiment of the collapsible shade structure having four rectangular side panels and a roof comprising two triangular panels;
FIG. 10 is a fifth embodiment similar to the embodiment of FIG. 1, having three triangular side panels along two of the sides thereof;
FIGS. 11(A) through 11(F) illustrate the operation of the collapsible shade structure of FIG. 1 showing how it may be folded up for compact storage;
FIG. 12 is a perspective view of a further embodiment of the collapsible shade structure which may be used as a cabana, showing a side panel acting as a door in an open position exposing the interior of the cabana; an
FIG. 13 is a perspective view of one of the corners of the cabana of FIG. 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments of the present invention will be described in terms of tents with reference to FIGS. 1-13, although the principles and concepts are equally applicable to other collapsible shade structures. The scope of the invention is best defined by the appended claims.
As shown in FIGS. 1, 2 and 3, the basic structure for a tent 30 comprises four resilient frame members 34, 38, 42 and 46. Each of the frame members 34, 38, 42 and 46 has three sides connected by curved portions to form a triangular-shape. The frame members 34, 38, 42 and 46 are retained in position by fabric or sheet material 50, which includes internal frame retaining sleeves 54, 58, 62 and 66 for retaining the frame members 34, 38, 42 and 46, respectively. The internal frame retaining sleeves 54, 58, 62 and 66 may be provided by mechanically fastening (stitching), fusing, or gluing so that the frame members 34, 38, 42, and 46 are retained in position. The fabric 50 in conjunction with the frame members 34, 38, 42, and 46 form four triangular side panels 70, 74, 78, and 82, respectively, so that each frame member is used to support one side panel. Each side panel and its associated frame member is vertically inclined inwardly at an angle to create a domed structure in which the interior area of the structure gradually decreases from the bottom to the top
Although the frame members 34, 38, 42, and 46 are described as formed of flexible steel, other materials such as plastics may be used. The frame members should be made of a material which is relatively strong and yet is flexible to a sufficient degree to allow it to be coiled. The term fabric is to be given its broadest meaning and should be made from strong, lightweight materials and may include woven fabrics, sheet fabrics or even films. The fabric should be waterproof and capable of withstanding the harsh outdoor environment to be suitable for use as an outdoor tent during camping. The fabric and frame members are preferably made of lightweight material to facilitate ease of transportation of the tent.
The tent 30 is further provided with a roof 86 which is made of the same material as fabric 50. The roof 86 is located between the upper curved portions of the side panels 70, 74, 78 and 82 and takes the form of an interconnecting fabric.
A floor portion 84 which may be made from the same material as the fabric 50 is provided to interconnect the lower edges of the side panels 70, 74, 78 and 82. Ties 88 are provided at the corners of the side panels 70, 74, 78 and 82 for securing the tent 30 to the ground. The area of the floor 84 is larger than the area of the roof 86 due to the vertically inclined side panels forming the domed structure.
The tent 30 is also provided with a door 90, preferably located in a side panel, for example, side panel 70, for ingress and egress. The door 90 is essentially a triangular-shaped cutout in the side panel 70 having a portion which is made of a fly-screen 94. The door 90 has two zipper edges 98 and 102 and a hinged edge 106. Mating zipper halves are provided along each side of the edges 98 and 102 of the door 90 and the corresponding edges of the side panel 70 to releasably hold the door 90 in a sealed position when the tent 30 is being occupied and the zippers pulled up.
Ventilation of the tent 30 is achieved through the fly-screen 94 and through vents 110 and 114 disposed at the upper curved portion of side panels 74 and 82, respectively. Vents 110 and 114 have the same construction. For example, referring to FIGS. 1, 3, 4, and 5, the vent 110 has a waterproof hood 118 which is sewn along the upper curved edges of the side panel 74. The hood 118 extends outwardly from the side panel 74 in an open position. The outer periphery 120 of the hood 118 is formed by a small steel loop 122 enclosed within the outer periphery 120 which defines the semi-circular shape of the outer periphery 120. A hinged hook 126 is provided at a central portion of the outer periphery 120. A strip 130 having one end sewn to a central portion of the bottom of side panel 74 has an opposite end which may be hooked by the hinged hook 126 to keep the hood open The upper portion of side panel 74 is made up of a mesh portion 132. The upper curved portion of the frame member 38 and an elongated steel strip 138 together define the semi-circular shape of the mesh portion 132. The outer periphery 120 of the hood 118 and the steel strip 138 define a semi-circular shape for fitting another screen mesh 134 therebetween.
The vent 110 may be held in the open position shown in FIGS. 1, 3, and 5 by hooking the strip 130 to the hook 126. The hood 118 is retracted when the tent 30 is to be collapsed and stored. When the hood 118 is to be retracted, the strip 130 is unhooked from the hook 126, and the hood 118 is pulled upwardly so that the hinged hook 126 may be made to hook an elastic loop 142 so that the screen mesh 134 is held firmly against the mesh portion 132 of the side panel 74. Regardless of whether the hood 118 is tied in the open or in the closed position, the mesh portion 132 and the screen mesh 134 provide ventilation to the inside compartment of the tent 30, as well as shielding the interior of the tent 30 from bugs and insects.
FIG. 6 illustrates an additional modification that may be made to the tent 30 of the present invention. For example, rods 146 and 150 are provided in a manner perpendicular to each other to provide further support to the upper portion of the tent and, in particular, the roof 86. Openings 154 are provided at an upper central portion of each side panel for receiving the ends of the rods 146 and 150. A retaining member 158 is fixed at the central point of the roof 86 and holds the rods 146 and 150 perpendicular to each other in such a manner that each end of the rod 146 or 150 is fitted through a guide 162 and its corresponding opening 154. This provides more stability to the roof 86 of the tent 30.
FIG. 7 illustrates a second embodiment 200 of the tent of the present invention wherein the tent 200 is provided with six inclined triangular side panels as opposed to the four triangular side panels shown in the embodiment of FIG. 1. As with the embodiment of FIG. 1, each side panel 204 is provided with a separate frame member 208 to provide the necessary stable support.
FIG. 8 illustrates a third embodiment 230 of the tent of the present invention wherein five inclined triangular side panels 234 supported by five frame members 238 are provided.
FIG. 9 illustrates a fourth embodiment 250 of the tent of the present invention wherein four rectangular side panels 254 are provided but are arranged to stand vertically as opposed to being inclined at an angle so as to form a rectangular internal block or space. The roof in the embodiment of FIG. 9 may be formed by two triangular-shaped frame members 258 which ma be folded one upon the other when the tent is folded up.
FIG. 10 illustrates a fifth embodiment 280 of the tent of the present invention wherein two opposing walls 284 may be lengthened by providing three inclined side panels 288 to comprise each wall 284, each side panel 288 supported by a separate frame member 292.
It can be seen, therefore, that the tent of the present invention may take a variety of external shapes. These external shapes are facilitated by the provision of additional frame members configured to form the desired shape. Each side of the tent, regardless of the shape, is supported by at least one frame member. The tent may be of any size but is commonly of such a size as to accommodate one or more persons.
FIGS. 11(A) through 11(F) describe the various steps for folding the tent 30 of the embodiment of FIGS. 1-5 for storage. In FIG. 11(A), the first step consists of pushing in side panels 70 and 74 such that side panel 70 collapses upon side panel 82 and side panel 74 collapses upon side panel 78. Then, in the second step shown in FIG. 11(B), the two side panels 70 and 82 are folded so as to be collapsed upon the two side panels 74 and 78. The structure is twisted and folded to collapse the frame members and side panels into a smaller shape. In the third step shown in FIGS. 11(C) and 11(D), the opposite border 320 of the structure is folded in upon the previous fold to further collapse the frame members with the side panels. As shown in FIG. 11(E), the fourth step is to continue the collapsing so that the initial size of the structure is reduced. FIG. 11(F) shows the fifth step with the frame members and side panels collapsed on each other to provide for a small essentially compact configuration having a plurality of concentric frame members and layers of the side panels so that the collapsed structure has a size which is a fraction of the size of the initial structure.
Therefore, the present invention provides a collapsible shade structure in which each side panel is supported by at least one frame member to provide stable support for the entire structure. The collapsible shade structure may be easily collapsed by folding and twisting the frame members and the side panels to cause the frame members to collapse within themselves to form smaller concentric frame members and layers of side panels to create a compact folded configuration which may be stored and transported very easily.
Referring to FIG. 12, the collapsible shade structure of the present invention may take the form of a cabana 170. The cabana 170 is comprised of three side panels 174, 178 and 182, each supported by a frame member, 176, 180 and 184, respectively. The cabana 170 also has a mesh door 186 which is also supported by a frame member 188. The mesh door 186 is sewn to the roof 190 along a hinged edge 194 so that the mesh door may be flipped up or down about the hinged edge 194. The mesh door 186 may be flipped to an open position such as that shown in FIG. 12 and held in place atop the roof 190 by means of "Velcro" pads 198. As shown in FIG. 13, the four corners of the cabana may be provided with pockets 202 which are used to collect sand. Each pocket 202 is provided with a flap 206, which is normally secured to the pocket 202 by means of "Velcro" pads, but the flap 206 may be opened to allow the sand collected therein to be emptied.
While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.
The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims ar therefore intended to be embraced therein. | 4y
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This invention relates to nitrogen atom-containing polysiloxanes which can be synthesized from inexpensive reactants and useful as the main component of fiber and fabric finishing agent compositions for imparting softness and durability of home laundering to a variety of fibers or fibrous materials, methods for preparing the same, and fiber and fabric finishing agent compositions.
BACKGROUND OF THE INVENTION
A number of organopolysiloxanes such as dimethylpolysiloxanes, epoxy group-containing polysiloxanes, and nitrogen atom-containing polysiloxanes have been widely used as treating agents for imparting softness and smoothness to a variety of fibers or fibrous materials. Most widely used among others are the nitrogen atom-containing polysiloxanes, especially aminoalkyl group-containing organopolysiloxanes, which can impart satisfactory softness to a variety of fibers or fibrous materials. More specifically, fiber treating agents based on organopolysiloxanes having such aminoalkyl groups as —C 3 H 6 NH 2 and —C 3 H 6 NHC 2 H 4 NH 2 are widely used because of their softness capability as disclosed in JP-B 48-1480, JP-B 54-43614, JP-B 57-43673, JP-A 60-185879, JP-A 60-185880, and JP-A 64-61576.
These nitrogen atom-containing polysiloxanes are generally synthesized by equilibrating with alkalis dimethyl cyclics such as 1,1,3,3,5,5,7,7-octamethyl-cyclotetrasiloxane, nitrogen atom-containing trialkoxy-silanes, nitrogen atom-containing cyclopolysiloxanes, etc.
In the silicone industry, the dimethylsiloxy sources for polysiloxanes are dimethyl cyclics obtained by hydrolyzing dimethyldichlorosilane and distilling the hydrolyzate, and α,ω-dihydroxydimethylpolysiloxane which is the still residue. Since the former is in greater demand than the latter, the latter is converted by cracking into the former as needed. As compared with the former, the latter is inexpensive.
Since the nitrogen atom-containing polysiloxanes as typified by aminoalkyl group-containing organopolysiloxanes are currently used for general purposes, there is an increasing demand for cost reduction. If α,ω-dihydroxydimethylpolysiloxane could be used as the starting reactant, it would become possible to synthesize nitrogen atom-containing polysiloxanes in an inexpensive manner. There is a need for such a synthetic method.
As the method for obtaining higher molecular weight polysiloxanes from α,ω-dihydroxydimethylpolysiloxane as the starting reactant, alcohol-removing reaction with alkoxysilanes is known. However, a high temperature or a catalyst is essential for this reaction because of low reactivity. British Patent No. 9,188,239 discloses the use of an amino compound salt with phosphoric acid or carboxylic acid as the catalyst. Japanese Patent No. 2,857,203 discloses the use of strontium hydroxide or barium hydroxide as the catalyst. However, the amino compound salts with phosphoric acid or carboxylic acid give rise to a yellowing problem when applied to white or tint color fibers or fibrous materials. Additionally, it is difficult to remove the catalyst from the product since most of these catalysts are liquid. On the other hand, such catalysts as strontium hydroxide and barium hydroxide also become foreign matters in the fiber treating step and cause cracking of polysiloxanes. This necessitates an extra step of removing the catalyst. An efficient reaction method without a need for a catalyst is thus demanded.
Among prior art nitrogen atom-containing poly-siloxanes, aminoalkyl group-containing organopolysiloxanes are most common. They suffer from the problem that the softness imparted thereby lowers during long-term use or by repeated washing. There is a need for nitrogen atom-containing polysiloxanes having long-lasting performance.
JP-B 46-3627 discloses the condensates of α,ω-dihydroxydimethylpolysiloxane with amino group-containing alkoxysilanes, but reaction conditions are described nowhere. In Examples described therein, the ratio of the moles of α,ω-dihydroxydimethylpolysiloxane to the moles of amino group-containing alkoxysilane is 0.07 or 0.02. These ratios are outside the range used in the present invention. Also, JP-A 6-184257 discloses analogous condensates, but no reference is made to the preparation method. No alkoxy groups are left in these condensates, that is, all alkoxy groups are replaced by α,ω-dihydroxydimethylpolysiloxane. This structure differs from the polysiloxanes of the present invention. Further, U.S. Pat. No. 3,355,424 discloses piperidyl group-containing organopolysiloxanes which are prepared by hydrolytic condensation of an addition product of allyloxypiperidine and a dialkoxysilane. This preparation method differs from the method of the present invention. No alkoxy groups are left in these condensates.
Further, fibers treated with organopolysiloxanes having such aminoalkyl groups as —C 3 H 6 NH 2 and —C 3 H 6 NHC 2 H 4 NH 2 suffer from degradation of amino groups by heat or ultraviolet radiation during heat treatment, drying or aging. In particular, white or tint color fibers or fibrous materials treated with such organopolysiloxanes have the serious problem that their color changes to yellow and their softness lowers during heat treatment, drying or aging.
For preventing the yellowing problem, it was proposed to modify aminoalkyl group-containing organopolysiloxanes, for example, by reacting the aminoalkyl groups with organic acid anhydrides or chlorides (JP-A 57-101046), epoxy compounds (JP-A 59-179884), higher fatty acids (JP-A 1-306683), and carbonates (JP-A 2-47371).
As compared with the unmodified aminoalkyl group-containing organopolysiloxanes, these modified organopoly-siloxanes were found to be improved in anti-yellowing effect, but to a still insufficient extent. With respect to the impartment of softness and smoothness to fibers or fabrics, the modified ones are rather inferior to the unmodified ones.
SUMMARY OF THE INVENTION
An object of the invention is to provide a novel and improved nitrogen atom-containing polysiloxane which is effective as a main component of a fiber-treating agent composition for imparting softness and smoothness to fibers or fibrous materials while minimizing the yellowing thereof.
Another object of the invention is to provide a novel and improved nitrogen atom-containing polysiloxane which is effective as a main component of a fiber and fabric finishing agent composition for imparting to fibers or fibrous materials a softness which is not only high at the initial, but also lasts even after washing.
A further object of the invention is to provide a method for preparing the nitrogen atom-containing polysiloxane.
A still further object of the invention is to provide a fiber and fabric finishing agent composition comprising the nitrogen atom-containing polysiloxane as a main component.
We have found that an organopolysiloxane having some alkoxy groups left intact is effective for enhancing the bond to a substrate and improving softness, and durability of home laundering. In the resulting polymer, amino group-containing silicon atoms are not present as blocks, but regularly distributed in accordance with the degree of polymerization of α,ω-dihydroxypolysiloxane. This feature is the largest difference from the polymers prepared by the prior art technique of alkali equilibration. The regular distribution of amino groups in the polymer is effective for improving softness and durability. The invention is predicated on this finding.
In a first aspect, the invention provides a nitrogen atom-containing polysiloxane having at least one polymer terminus represented by the general formula (1).
Herein R 1 is a nitrogen-free, substituted or unsubstituted, monovalent organic group of 1 to 20 carbon atoms, R 2 is a monovalent organic group containing at least one nitrogen atom, R 3 is an organoxy group represented by —OR 1 , and p is a positive number of 2 to 2,000.
In a second aspect, the invention provides a method for preparing a nitrogen atom-containing polysiloxane as defined above, comprising the step of effecting alcohol-removing reaction between (A) an organopolysiloxane of the general formula (5):
wherein R 1 and p are as defined above and (B) an organosilane of the general formula (6):
wherein R 1 , R 2 , and R 3 are as defined above.
In a third aspect, the invention provides a nitrogen atom-containing polysiloxane comprising at least one unit represented by the general formula (11).
Herein R 1 is a nitrogen-free, substituted or unsubstituted, monovalent organic group of 1 to 20 carbon atoms, R 2 is independently a monovalent organic group containing at least one nitrogen atom, R 3 is an organoxy group represented by —OR 1 , and p is a positive number of 2 to 2,000.
In a fourth aspect, the invention provides a method for preparing a nitrogen atom-containing polysiloxane as defined above, comprising the step of effecting alcohol-removing reaction between (A) an organopolysiloxane of the general formula (5):
wherein R 1 and p are as defined above and (C) an organosilane of the general formula (13):
wherein R 2 and R 3 are as defined above.
Also contemplated herein is a fiber and fabric finishing agent composition comprising the above-defined nitrogen atom-containing polysiloxane as a main component.
We have found that a nitrogen atom-containing polysiloxane in which a nitrogen atom-containing group of formula (1) is selectively introduced into the polymer terminal group, upon treatment of fibers or fibrous materials therewith, ensures efficient reaction with fiber surfaces, improves durability, minimizes yellowing by heat or UV radiation after treatment because of a reduced number of nitrogen atoms not adsorbed on fiber surfaces, prevents the fibers or fibrous materials from yellowing, and imparts excellent softness.
Although the prior art method of synthesizing nitrogen atom-containing polysiloxanes by equilibrating with alkalis dimethyl cyclics such as 1,1,3,3,5,5,7,7-octamethyl-cyclotetrasiloxane, nitrogen atom-containing trialkoxy-silanes, nitrogen atom-containing cyclopolysiloxanes, etc. is impossible to selectively introduce a nitrogen atom-containing group into the polymer terminus, the compound of the invention can be prepared by reacting αω-dihydroxydimethylpolysiloxane with a nitrogen atom-containing dialkoxysilane while removing the resultant alcohol from the reaction system. Since the nitrogen atom-containing trialkoxysilane functions as a catalyst for removing the alcohol, this reaction readily takes place without a need for a catalyst.
JP-A 9-137061 discloses a nitrogen atom-containing polysiloxane prepared by alcohol-removing reaction of αω-dihydroxydimethylpolysiloxane as the starting reactant. This method has the drawback that reaction is very slow in the absence of a catalyst such as sodium phosphate or barium hydroxide. Where the catalyst is used, an extra step of neutralizing or removing the catalyst is necessary, complicating the overall process. The average structure of the thus prepared polysiloxane is described in this patent although the general structure is described nowhere. It is not attempted to produce a nitrogen atom-containing polysiloxane having a nitrogen atom-containing group selectively introduced at the polymer terminus as in the present invention.
By 29 Si-NMR analysis, we have found the following fact. When αω-dihydroxydimethylpolysiloxane is reacted with a nitrogen atom-containing dialkoxysilane, the nitrogen atom-containing dialkoxysilane becomes a self catalyst so that the first alkoxy group may undergo quick alcohol-removing reaction without a need for catalyst, but the second alkoxy group undergoes little alcohol-removing reaction. Further, where a nitrogen atom-containing trialkoxysilane is used, this nitrogen atom-containing alkoxysilane similarly becomes a self catalyst so that the first and second alkoxy groups may undergo quick alcohol-removing reaction without a need for catalyst, but the third alkoxy group is quite poorly reactive as compared with the first and second ones.
We have thus found that by reacting inexpensive αω-dihydroxydimethylsiloxane with a nitrogen atom-containing triorganoxysilane on the basis of the above-described reaction scheme, a novel nitrogen atom-containing polysiloxane having a desired degree of polymerization is readily obtainable without a need for catalyst. In the resulting nitrogen atom-containing polysiloxane, nitrogen atom-containing groups are not present as blocks, but introduced at regular intervals in the polymer, and organoxy groups are contained on polymer side chains. For this reason, as compared with prior art nitrogen atom-containing polysiloxanes, the nitrogen atom-containing polysiloxane of the invention firmly bonds with fibers, accomplishing excellent softness, long-term softness retention, and durability of home laundering.
Also, the nitrogen atom-containing polysiloxane comprising units of formula (11) is prepared by starting with αω-dihydroxydimethylpolysiloxane which is the still residue after removal of cyclic polysiloxanes in the step of vacuum distilling hydrolyzates of dimethyldichlorosilane. Because low molecular weight components have almost been removed, the nitrogen atom-containing polysiloxane has a minimized content of low molecular weight components as compared with the prior art nitrogen atom-containing polysiloxanes resulting from equilibration. This minimizes the build-up problem or the contamination in a treatment dryer line by low molecular weight siloxanes.
Furthermore, the synthetic method of the invention can readily produce a silanol-terminated nitrogen atom-containing polysiloxane having a degree of polymerization of less than 200, although the prior art technique of equilibration with alkali compounds was difficult to produce such a polysiloxane.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an NMR spectrum of the compound obtained in Synthetic Example 1.
FIG. 2 is an NMR spectrum of the compound obtained in Synthetic Example 8.
FIG. 3 is an NMR spectrum of the compound obtained in Synthetic Example 10.
FIG. 4 is an NMR spectrum of the compound obtained in Synthetic Example 11.
DESCRIPTION OF THE PREFERRED EMBODIMENT
First Embodiment
In the first embodiment, the nitrogen atom-containing polysiloxane has at least one polymer terminus represented by the general formula (1).
Herein R 1 is a nitrogen-free, substituted or unsubstituted, monovalent organic group of 1 to 20 carbon atoms, R 2 is a monovalent organic group containing at least one nitrogen atom, R 3 is an organoxy group represented by —OR 1 , and p is a positive number of 2 to 2,000. The other terminus of the nitrogen atom-containing polysiloxane may be a hydroxyl group or a OSiR 1 R 2 R 3 group or even a OSiR 1 3 or OSiR 1 2 R 3 group.
The polysiloxane is typically represented by the following general formula (I).
Herein, R is —OH, —OSiR 1 3 , —OSiR 1 2 R 3 or —OSiR 1 R 2 R 3 .
In the organopolysiloxanes of the invention, the organic groups represented by R 1 include substituted or unsubstituted monovalent hydrocarbon groups of 1 to 20 carbon atoms, and especially 1 to 3 carbon atoms. Examples of the organic groups represented by R 1 include alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, dodecyl, tetradecyl, octadecyl, and eicosyl, alkenyl groups such as vinyl, allyl, propenyl, butenyl and hexenyl, aryl groups such as phenyl and tolyl, aralkyl groups such as benzyl, phenylethyl and phenylpropyl, cycloalkyl groups such as cyclopentyl and cyclohexyl, and substituted ones of the foregoing groups in which some or all of the hydrogen atoms attached to carbon atoms are replaced by halogen atoms, e.g., halogenated alkyl groups such as chloromethyl and trifluoropropyl, and halogenated aryl groups such as chlorophenyl. Of these, preferably at least 90 mol % of the R 1 groups are methyl, phenyl, and trifluoropropyl.
R 2 stands for monovalent organic groups containing at least one nitrogen atom, for examples, groups of the following formulae (2), (3) and (4).
—R 4 (NR 5 CH 2 CH 2 ) a NR 6 2 (2)
R 4 stands for divalent hydrocarbon groups of 1 to 6 carbon atoms, for example, alkylene groups such as methylene, dimethylene, trimethylene, tetramethylene, pentamethylene, and hexamethylene. Of these, trimethylene is desirable.
R 5 and R 6 are independently hydrogen or unsubstituted or hydroxyl-substituted monovalent hydrocarbon groups of 1 to 50 carbon atoms which may be separated by an oxygen atom, especially unsubstituted or hydroxyl-substituted alkyl groups. Examples are monovalent hydrocarbon groups of 1 to 8 carbon atoms including alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl and octyl, and phenyl. Also included are groups represented by COR wherein R is an alkyl group of 1 to 10 carbon atoms and groups represented by CH 2 CH(OH)CH 2 O(C 2 H 4 O) n R 9 wherein R 9 is hydrogen or a monovalent hydrocarbon group such as C 1-8 alkyl, and n is a positive number of 0 to 10. R 5 and R 6 may be the same or different, and a pair of R 6 may also be the same or different. Of these groups, hydrogen and methyl are preferred.
R 7 is —CH═, —N═, —OCH═or —ON═, and R 8 is hydrogen or methyl.
In formula (2), “a” is an integer of 0 to 4. Illustrative examples of the organic group R 2 represented by formula (2) include
—C 3 H 6 NH 2 ,
—C 3 H 6 NHC 2 H 4 NH 2 , and
—C 3 H 6 NHC 2 H 4 NHC 2 H 4 NH 2 .
Also included are substituted ones of these illustrative examples in which one or two hydrogen atoms in NH or NH 2 are replaced by COR wherein R is a C 1-10 alkyl group and in which one or two hydrogen atoms in NH or NH 2 are replaced by CH 2 CH(OH)CH 2 O(C 2 H 4 O) n R 9 wherein R 9 is hydrogen or a monovalent hydrocarbon group (e.g., C 1-8 alkyl) and n is a positive number of 0 to 10.
In formula (1), R 3 is an organoxy group represented by —OR 1 , preferably an alkoxy group of 1 to 6 carbon atoms. Illustrative examples of R 3 are methoxy, ethoxy and propoxy groups, with methoxy being most preferred.
Letter p is a positive number satisfying 2≦p≦2,000, and preferably 10≦p≦300.
Illustrative examples of the nitrogen atom-containing polysiloxane having at least one polymer terminus represented by the general formula (1) are given below.
Also included are substituted ones of these illustrative compounds in which one or two hydrogen atoms in NH or NH 2 are replaced by COR wherein R is a C 1-10 alkyl group and in which one or two hydrogen atoms in NH or NH 2 are replaced by CH 2 CH(OH)CH 2 O(C 2 H 4 O) n R 9 wherein R 9 is hydrogen or a monovalent hydrocarbon group (e.g., C 1-8 alkyl) and n is a positive number of 0 to 10.
According to the invention, the nitrogen atom-containing polysiloxane of the first embodiment can be prepared by effecting alcohol-removing reaction between (A) a both end hydroxyl-blocked organopolysiloxane of the following general formula (5) and (B) a nitrogen atom-containing organosilane of the following general formula (6).
Herein R 1 , R 2 , R 3 and p are as defined above.
In formula (5), p is a positive number of 2 to 2,000 as defined above. If p is less than 2, because of unstable silanol, condensation reaction takes place parallel to the reaction with component (B), resulting in cyclic by-products. An organopolysiloxane of formula (5) in which p is greater than 2,000 is less reactive with a nitrogen-containing organosilane of formula (6). Preferably p is from 10 to 300. R 1 is as defined above, and preferably at least 90 mol % of the R 1 groups are methyl, phenyl, and trifluoropropyl. Illustrative examples of the organopolysiloxane of formula (5) are given below.
In formula (6), R 1 , R 2 and R 3 are as defined for formula (1). Where R 2 stands for groups of formula (2), those groups wherein R 6 is H are preferred because of a high catalytic activity in reaction with component (A). Methyl is most preferred as R 1 . Methoxy is most preferred as R 3 because it facilitates alcohol-removing reaction. Illustrative examples of such organosilanes are given below.
Where R 2 stands for groups of formula (3), those groups wherein R 5 and R 8 are hydrogen atoms are preferred because of a high catalytic activity in reaction with component (A). Methyl is most preferred as R 1 . Methoxy is most preferred as R 3 because it facilitates alcohol-removing reaction. Illustrative examples of such organosilanes are given below.
Where R 2 stands for groups of formula (4), those groups wherein R 5 and R 8 are hydrogen atoms are preferred because of a high catalytic activity in reaction with component (A). Methyl is most preferred as R 1 . Methoxy is most preferred as R 3 because it facilitates alcohol-removing reaction. An illustrative example of such organosilanes is given below.
Where R 2 in formula (6) stands for groups of formulae (2) to (4), it is preferred that R 5 and R 6 be hydrogen or monovalent C 1-8 hydrocarbon groups such as alkyl or phenyl.
The conditions for reaction between components (A) and (B) generally include a temperature of about 50 to 180° C. and a time of about 3 to 20 hours although the conditions depend on the reactivity of silanol in component (A) and the reactivity of organoxy group, especially alkoxy group in component (B). By this reaction, a nitrogen atom-containing polysiloxane as represented by formula (1) is readily obtained. Since the alcohol by-product precludes the progress of reaction, reaction must be effected under a nitrogen stream while removing the resultant alcohol. No solvent is generally necessary although a solvent such as toluene or xylene may be used if component (A) has a high viscosity. If the reaction is slow, a catalyst such as triethylamine or tetramethylene ethylenediamine is optionally used.
The molar ratio of component (A) to component (B) used is preferably 0.5≦(A)/(B)≦1.0, and more preferably 0.6≦(A)/(B)≦1.0. If the molar ratio (A)/(B) is more than 1.0, an excess of the nitrogen atom-free polysiloxane may be left behind. If (A)/(B) is less than 0.5, the dialkoxysilane reactant may be left behind.
When reaction is effected at (A)/(B)>0.5, a nitrogen atom-containing polysiloxane having a nitrogen atom-containing group at one terminus and a silanol group left at the other terminus is obtainable as part of the product. This polysiloxane has relatively rich reactivity and forms a firmer bond with fibers, thus providing satisfactory softness, long-term softness retention and durability of home laundering. When storage in polysiloxane form is necessary, however, the same polysiloxane undergoes a viscosity rise over time under certain storage conditions. Accordingly, if necessary, the other terminus of the polysiloxane is converted into a non-functional or relatively less functional group such as a trimethylsilyl or dimethylmethoxysilyl group by reacting the polysiloxane with a silylating agent such as trimethylsilanol or N,O-(bistrimethylsilyl)acetamide or a difunctional alkoxysilane such as dimethyldimethoxysilane. Also an alcohol or glycol compound such as methanol, ethanol, propanol or ethylene glycol may be added to the polysiloxane for suppressing a viscosity rise.
It is a common practice to modify conventional nitrogen atom-containing polysiloxanes by reacting them with organic acids, inorganic acids or epoxy compounds. This is optionally applicable to the nitrogen atom-containing polysiloxane obtained by the inventive method. For example, the nitrogen atom-containing polysiloxane is modified with organic acids, inorganic acids or epoxy compounds in order that one or two hydrogen atoms in NH or NH 2 be replaced by COR or CH 2 CH(OH)CH 2 O(C 2 H 4 O) n R 9 wherein R is a C 1-10 alkyl group, R 9 is hydrogen or a monovalent hydrocarbon group (e.g., C 1-8 alkyl) and n is a positive number of 0 to 10. Examples of the organic acid used herein include formic acid, acetic acid, acetic anhydride, and propanoic acid, with acetic acid and acetic anhydride being preferred. Examples of the inorganic acid used herein include hydrochloric acid and phosphoric acid. Examples of the epoxy compound are those of the following general formula (7).
Herein R 9 is hydrogen or a monovalent hydrocarbon group (e.g., C 1-8 alkyl) and n is a positive number of 0 to 10. R 9 is preferably hydrogen or butyl.
Second Embodiment
In the second embodiment, the nitrogen atom-containing polysiloxane contains at least one unit represented by the general formula (11).
Herein R 1 is a nitrogen-free, substituted or unsubstituted, monovalent organic group of 1 to 20 carbon atoms, R 2 is independently a monovalent organic group containing at least one nitrogen atom, R 3 is an organoxy group represented by —OR 1 , and p is a positive number of 2 to 2,000.
The nitrogen atom-containing polysiloxane containing at least one unit of formula (11) may have any desired terminal group selected from, for example, among dialkylhydroxysilyl, trialkylsilyl, alkyldialkoxysilyl, and dialkylalkoxy groups. Of these, dialkylhydroxysilyl, trialkylsilyl, and alkyldialkoxysilyl groups are preferred from the stability standpoint. Those groups of the following general formula (12) or (12′) are especially preferred.
In the polysiloxane terminus represented by formula (12) or (12′), R 1 , R 2 and R 3 are as defined for formula (11). Illustrative examples of the organic groups represented by R 1 and R 2 are as previously described in conjunction with the first embodiment. R 2 preferably stands for monovalent organic groups of the formulae (2), (3) and (4) wherein R 4 to R 8 and “a” are as previously described. Also, R 3 and p are as previously described in conjunction with the first embodiment.
Where R 2 stands for groups of formula (2), those groups wherein R 6 is H are preferred because of a high catalytic activity in reaction with component (A). Methoxy is most preferred as R 3 because it facilitates alcohol-removing reaction. Illustrative examples of such terminal groups are given below.
The polysiloxane in the second embodiment is typically represented by the following general formula (II).
Herein, R′ is H, —SiR 1 3 , —SiR 1 2 R 3 , —SiR 1 R 3 2 or —SiR 1 R 2 R, two R′ groups may be the same or different, and q is a number of 1 to 30, and especially equal to 1, 2 or 3.
Illustrative examples of the nitrogen atom-containing polysiloxane containing at least one unit of formula (11) are given below.
Also included are substituted ones of these illustrative compounds in which one or two hydrogen atoms in NH or NH 2 are replaced by COR wherein R is a C 1-10 alkyl group and in which one or two hydrogen atoms in NH or NH 2 are replaced by CH 2 CH(OH)CH 2 O(C 2 H 4 O) n R 9 wherein R 9 is hydrogen or a monovalent hydrocarbon group (e.g., C 1-8 alkyl) and n is a positive number of 0 to 10.
According to the invention, the nitrogen atom-containing polysiloxane of the second embodiment can be prepared by effecting alcohol-removing reaction between (A) a both end hydroxyl-blocked organopolysiloxane of the following general formula (5) and (C) a nitrogen atom-containing organosilane of the following general formula (13).
Herein R 1 , R 2 , R 3 and p are as defined above.
In formula (5), p is a positive number of 2 to 2,000 as defined above. If p is less than 2, because of unstable silanol, condensation reaction takes place parallel to the reaction with component (C), resulting in cyclic by-products. An organopolysiloxane of formula (5) in which p is greater than 2,000 is less reactive with a triorganoxy-silane of formula (13). Preferably p is from 10 to 500. R 1 is as defined above, and preferably at least 90 mol % of the R 1 groups are methyl, phenyl, and trifluoropropyl. Illustrative examples of the organopolysiloxane of formula (5) are as described in conjunction with the first embodiment.
In formula (13), R 2 and R 3 are as defined for formula (1). Where R 2 stands for groups of formula (2), those groups wherein R 6 is H are preferred because of a high catalytic activity in reaction with component (A). Methoxy is most preferred as R 3 because it facilitates alcohol-removing reaction. Illustrative examples of such organosilanes are given below.
(CH 3 O) 3 SiCH 2 CH 2 CH 2 NH 2
(CH 3 O) 3 SiCH 2 CH 2 CH 2 NHCH 2 CH 2 NH 2
(CH 3 O) 3 SiCH 2 CH 2 CH 2 NHCH 2 CH 2 NHCH 2 CH 2 NH 2 .
Where R 2 stands for groups of formula (3), those groups wherein R 5 and R 8 are hydrogen atoms are preferred because of a high catalytic activity in reaction with component (A). Methoxy is most preferred as R 3 because it facilitates alcohol-removing reaction. Illustrative examples of such organosilanes are given below.
Where R 2 stands for groups of formula (4), those groups wherein R 5 and R 8 are hydrogen atoms are preferred because of a high catalytic activity in reaction with component (A). Methoxy is most preferred as R 3 because it facilitates alcohol-removing reaction. An illustrative example of such organosilanes is given below.
Where R 2 in formula (6) stands for groups of formulae (2) to (4), it is preferred that R 5 and R 6 be hydrogen or monovalent C 1-8 hydrocarbon groups such as alkyl or phenyl.
The conditions for reaction between components (A) and (C) generally include a temperature of about 50 to 180° C. and a time of about 3 to 20 hours although the conditions depend on the reactivity of silanol in component (A) and the reactivity of organoxy group, especially alkoxy group in component (C). By this reaction, a nitrogen atom-containing polysiloxane as represented by formula (11) is readily obtained. Since the alcohol by-product precludes the progress of reaction, reaction must be effected under a nitrogen stream while removing the resultant alcohol. No solvent is generally necessary although a solvent such as toluene or xylene may be used if component (A) has a high viscosity.
The molar ratio of component (A) to component (C) used is preferably 1.0<(A)/(C)≦4.0, and more preferably 1.0<(A)/(C)≦2.0. If the molar ratio (A)/(C) is more than 4.0, an excess of the nitrogen atom-free polysiloxane may be left behind. If (A)/(C) is less than 1.0, a polysiloxane having left therein two of the three alkoxy groups may form, detracting from aging stability.
When reaction is effected between components (A) and (C), a nitrogen atom-containing polysiloxane having a silanol group at either terminus is obtainable as a main product. This polysiloxane has relatively rich reactivity and forms a firmer bond with fibers, thus providing satisfactory softness, long-term softness retention and durability of home laundering. When storage in polysiloxane form is necessary, however, the same polysiloxane undergoes a viscosity rise over time under certain storage conditions. Accordingly, if necessary, the terminus of the polysiloxane is converted into a more stable terminus having an organoxy group of the general formula (12), especially alkoxy group by reacting the polysiloxane with a nitrogen atom-containing diorganoxysilane of the general formula (6):
wherein R 1 , R 2 and R 3 are as defined above, and especially a dialkoxysilane. Alternatively, the terminus of the polysiloxane can be converted into a non-functional or relatively less functional group such as a trimethylsilyl or dimethylmethoxysilyl group by reacting the polysiloxane with a silylating agent such as trimethylsilanol or N,O-(bistrimethylsilyl)acetamide or a difunctional alkoxysilane such as dimethyldimethoxysilane. Also an alcohol or glycol compound such as methanol, ethanol, propanol or ethylene glycol may be added at the end of reaction for suppressing a viscosity rise.
The modification of polysiloxanes by reaction with organic acids, inorganic acids or epoxy compounds is optionally applicable to the nitrogen atom-containing polysiloxane obtained by the inventive method. For example, the nitrogen atom-containing polysiloxane is modified with organic acids, inorganic acids or epoxy compounds in order that one or two hydrogen atoms in NH or NH 2 be replaced by COR or CH 2 CH(OH)CH 2 O(C 2 H 4 O) n R 9 wherein R is a C 1-10 alkyl group, R 9 is hydrogen or a monovalent hydrocarbon group (e.g., C 1-8 alkyl) and n is a positive number of 0 to 10. Examples of the organic acid used herein include formic acid, acetic acid, acetic anhydride, and propanoic acid, with acetic acid and acetic anhydride being preferred. Examples of the inorganic acid used herein include hydrochloric acid and phosphoric acid. Examples of the epoxy compound are those of the formula (7).
Composition
The fiber and fabric finishing agent composition of the invention contains a nitrogen atom-containing organo-polysiloxane of the first or second embodiment as a main component. The composition may take the form of solutions of the polysiloxane in organic solvents such as toluene, xylene, n-hexane, n-heptane, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, butyl acetate, and mineral turpentine, or emulsions of the polysiloxane with the aid of nonionic, anionic, cationic or ampholytic surfactants. The emulsifier used herein is not critical. Exemplary nonionic surfactants include ethoxylated higher alcohols, ethoxylated alkylphenols, polyhydric alcohol fatty acid esters, ethoxylated polyhydric alcohol fatty acid esters, ethoxylated fatty acids, ethoxylated fatty acid amides, sorbitol, sorbitan fatty acid esters, ethoxylated sorbitan fatty acid esters, and sucrose fatty acid esters. They preferably have a HLB in the range of 5 to 20, and especially 10 to 16. Exemplary anionic emulsifiers include higher alcohol sulfuric acid ester salts, alkyl phenyl ether sulfuric acid ester salts, alkylbenzenesulfonic acid salts, higher alcohol phosphoric acid ester salts, ethoxylated higher alcohol sulfuric acid ester salts, ethoxylated alkyl phenyl ether sulfuric acid ester salts, and ethoxylated higher alcohol phosphoric acid salts. Exemplary cationic emulsifiers include alkyltrimethylammonium chlorides, alkylamine hydrochloride salts, coconut amine acetate, alkylamine acetate, and alkylbenzenedimethylammonium chloride. Exemplary ampholytic surfactants include N-acylamidopropyl-N,N-dimethylammoniobetains, and N-acylamidopropyl-N,N′-dimethyl-N′-β-hydroxypropylammoniobetains. An appropriate amount of the surfactant used is about 5 to 50 parts and more preferably about 10 to 30 parts by weight per 100 parts by weight of the organopolysiloxane. On emulsification, water is preferably used in such amounts that the organopolysiloxane may be present in a concentration of 10 to 80% and preferably 20 to 60% by weight.
The emulsion may be prepared by conventional well-known techniques. Usually the organopolysiloxane and a surfactant are mixed and this mixture is emulsified by an emulsifying machine such as a homomixer, homogenizer, colloidal mill, line mixer, Universal Mixer (trade name), Ultra Mixer (trade name), Planetary Mixer (trade name), Combi-Mix (trade name) or three-roll mixer.
To the fiber and fabric finishing agent composition of the invention, suitable additives may be added insofar as the advantages of the composition are not impaired. Such additives are silicon compounds such as dimethylpoly-siloxane, αω-dihydroxydimethylpolysiloxane and alkoxy-silanes, and other additives such as anti-creasing agents, flame retardants, antistatic agents, antioxidants, preservatives, and anti-rusting agents.
Various fibers or fibrous materials are treated with the fiber and fabric finishing agent composition of the invention by adjusting the composition in emulsion form to a desired concentration, and applying the composition to fibers or fibrous material as by dipping, spraying or roll coating. The loading on fiber or fabric varies with the type of fibers and is not critical although an organopolysiloxane loading on fiber or fabric of 0.01 to 10% by weight is usually employed. The fibers or fibrous materials are then dried as by hot air blowing or in a heating oven. Drying may be effected at about 100 to 150° C. for about 2 to 5 minutes although the drying conditions vary with the type of fibers.
The fibers or fibrous materials which can be treated with the fiber and fabric finishing agent composition of the invention are not critical. It is effective to a wide spectrum of fibers including natural fibers such as cotton, silk, hemp, wool, Angora and mohair and synthetic fibers such as polyester, nylon, acrylic and spandex. The state and shape of fibers or fibrous materials are not critical. Not only raw material forms such as staples, filaments, tows, and threads, but also a variety of fibrous materials such as fabrics, knitted goods, batting, and non-woven fabrics can be treated with the fiber and fabric finishing agent composition of the invention.
EXAMPLE
Examples of the invention are given below by way of illustration and not by way of limitation. The viscosity is a measurement (centipoise) at 25° C.
Structural Analysis by 29 Si-NMR
Peaks in 29 Si-NMR were observed by uniformly dissolving 1.5 g of a sample and 0.04 g of tris(2,4-pentanedionate)chromium as a buffer reagent in 1.35 g of toluene and 0.15 g of benzene-d 6 , filling a sample tube of 10 mm in diameter therewith, operating an analyzer Lambda 300WB (JEOL), and determining 600 to 3,000 times collection.
Synthetic Example 1
A 500-ml glass flask equipped with an ester adapter, condenser and thermometer was charged with 476.5 g (0.030 mol) of αω-dihydroxydimethylpolysiloxane represented by the following average structural formula (i) as component (A) and 12.4 g (0.060 mol) of N-β-(aminoethyl)-γ-aminopropyl-methyldimethoxysilane as component (B). In a nitrogen stream, reaction was effected at 120° C. for 12 hours. In the ester adapter, the distillate of methanol resulting from methanol-removing reaction was observed. At the end of reaction, the resulting product (A-1) was subject to structural identification by 29 Si-NMR. The result that the peak (−2.7 ppm) of the reactant, N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane had disappeared indicated that all the silane had reacted. The NMR chart is as shown in FIG. 1, with attribution shown in Table 1.
TABLE 1
Chemical
shift
Number of silicone
(ppm)
atoms by integration ratio
Attribution
−12.5
2.0
−22.5
214.0
From the analytical results and the reaction route, the product was identified to have the following average structural formula (ii). The measurements of volatile content and rotational viscosity are shown in Table 2.
Synthetic Example 2
The procedure of Synthetic Example 1 was repeated except that the amount of N-β-(aminoethyl)-γ-aminopropyl-methyldimethoxysilane was changed to 6.2 g (0.030 mol). At the end of reaction, the resulting product (A-2) was subject to structural identification by 29 Si-NMR. The product was identified to have the following average structural formula (iii). The measurements of volatile content and rotational viscosity are shown in Table 2.
Synthetic Example 3
The procedure of Synthetic Example 1 was repeated except that 9.8 g (0.060 mol) of γ-aminopropylmethyl-dimethoxysilane was used instead of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane. At the end of reaction, there was obtained a viscous, colorless, clear oily product (A-3), which was subject to structural identification by 29 Si-NMR. The product was identified to have the following average structural formula (iv). The measurements of volatile content and rotational viscosity are shown in Table 2.
Synthetic Example 4
The procedure of Synthetic Example 1 was repeated except that 9.9 g (0.060 mol) of 3-piperazinopropylmethyl-dimethoxysilane was used instead of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane and the reaction conditions were 120° C. and 12 hours. At the end of reaction, there was obtained a viscous, colorless, clear oily product (A-4), which was subject to structural identification by 29 Si-NMR. The product was identified to have the following average structural formula (v). The measurements of volatile content and rotational viscosity are shown in Table 2.
Synthetic Example 5 (Comparison)
A 2000-ml glass flask equipped with a reflux condenser and thermometer was charged with 1586.8 g (21.4 mol) of octamethylcyclotetrasiloxane and 16.0 g (0.10 mol) of 1,3,5,7-tetra[N-β-(aminoethyl)-γ-aminopropyl ]-1,3,5,7-tetramethylcyclotetrasiloxane. In a nitrogen stream, the contents were dried at 120° C. for 2 hours. Then 20.6 g (0.10 mol) of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane and then 1.08 g (0.0020 mol) of a catalyst represented by the following average structural formula (vi) were added to the flask. Reaction was effected at 150° C. for 6 hours for polymerization. At the end of polymerization, the reaction mixture was cooled to 90° C. Ethylene chlorohydrin, 3.22 g (0.040 mol), was added to the reaction mixture whereupon reaction was effected at 90° C. for 2 hours for neutralization. At the end of reaction, there was obtained a viscous, colorless, clear oily product (A-5), which was subject to structural identification by 29 Si-NMR. The product was identified to have the following average structural formula (vii). The measurements of volatile content and rotational viscosity are shown in Table 2.
Synthetic Example 6
A 1000-ml glass flask equipped with an ester adapter, condenser and thermometer was charged with 344.8 g (0.10 mol) of αω-dihydroxydimethylsiloxane represented by the following average structural formula (viii) as component (A) and 41.3 g (0.20 mol) of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane as component (B). In a nitrogen stream, reaction was effected at 120° C. for 8 hours. In the ester adapter, the distillate of methanol resulting from methanol-removing reaction was observed. At the end of reaction, the reaction mixture was cooled to 80° C., to which 30 g of isopropyl alcohol and 204.4 g (0.60 mol) of an epoxy compound represented by the following average structural formula (ix) were added whereupon reaction was effected at 80° C. for 8 hours. By stripping under a vacuum of 5 mmHg at 120° C. for 2 hours, a colorless clear oil (A-6) having a viscosity of 1,018 cp was collected. The oil was analyzed by 1 H-NMR, finding that all the epoxy groups had reacted. Upon structural analysis by 29 Si-NMR, the oil was identified to have the following average structural formula (x). The measurements of volatile content and rotational viscosity are shown in Table 2.
Synthetic Example 7 (Comparison)
A 1000-ml glass flask equipped with a reflux condenser and thermometer was charged with 370.8 g (5.0 mol) of octamethylcyclotetrasiloxane and 16.0 g (0.25 mol) of 1,3,5, 7-tetra[N-β-(aminoethyl) -γ-aminopropyl]-1,3,5,7-tetramethylcyclotetrasiloxane. In a nitrogen stream, the contents were dried at 120° C. for 2 hours. Then 20.6 g (0.10 mol) of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane and then 0.54 g (0.0010 mol) of a catalyst represented by the above average structural formula (vi) were added to the flask. Reaction was effected at 150° C. for 6 hours for polymerization. At the end of polymerization, the reaction mixture was cooled to 90° C. Ethylene chlorohydrin, 1.61 g (0.020 mol), was added to the reaction mixture whereupon reaction was effected at 90° C. for 2 hours for neutralization. At the end of reaction, the reaction mixture was cooled to 80° C., to which 12 g of isopropyl alcohol and 204.2 g (0.60 mol) of an epoxy compound represented by the above average structural formula (ix) were added whereupon reaction was effected at 80° C. for 8 hours. By stripping under a vacuum of 5 mmHg at 120° C. for 2 hours, a colorless clear oil (A-7) having a viscosity of 1,018 cp was collected. The oil was analyzed by 1 H-NMR, finding that all the epoxy groups had reacted. Upon structural analysis by 29 Si-NMR, the oil was identified to have the following average structural formula (xi). The measurements of volatile content and rotational viscosity are shown in Table 2.
TABLE 2
SE 1
SE 2
SE 3
SE 4
SE 5
SE 6
SE 7
N-containing
A-1
A-2
A-3
A-4
A-5
A-6
A-7
polysiloxane
Volatile content @
0.5
0.1
0.2
0.3
12.5
1.6
1.4
105° C./3 hr (%)
Viscosity (cp)
1200
1180
1150
1180
640
1018
850
Example 1
To 150 g of the nitrogen atom-containing polysiloxane (A-1) synthesized in Synthetic Example 1 was added 90 g of polyoxyethylene tridecyl ether (amount of ethylene oxide added=10 mol, HLB=13.6). After mixing, 150 g of deionized water was added to the mixture, which was agitated at a high speed for 15 minutes by a homomixer for effecting phase inversion. Further, 610 g of deionized water was added to the mixture, which was agitated at 2,000 rpm for 15 minutes by the homomixer for effecting dilution, yielding a milky white emulsion.
To the emulsion was added 3.0 g of a cetic acid, followed by thorough agitation and heat treatment at 80° C. for 4 hours. The solution was further diluted with deionized water to a 100- fold volume, providing a test solution.
Pieces of polyester/cotton mixed (50%/50%) broadcloth and cotton broadcloth were dipped in the test solution for 1 minute, nipped through rolls at a nip rate of 100%, dried at 100° C. for 2 minutes, and heat treated at 150° C. for 2 minutes, obtaining treated cloth pieces. The softness of polyester/cotton mixed broadcloth and the home laundering test and yellowing of cotton broadcloth were evaluated according to the criteria shown below. The results are shown in Table 3.
Example 2
A test solution was prepared as in Example 1 except that the nitrogen atom-containing polysiloxane (A-2) synthesized in Synthetic Example 2 was used instead of the polysiloxane (A-1) and the amount of acetic acid was changed to 1.35 g. Pieces of cloth were similarly treated and tested for softness, home laundering test and yellowing. The results are shown in Table 3.
Comparative Example 1
A test solution was prepared as in Example 1 except that the nitrogen atom-containing polysiloxane (A-5) synthesized in Synthetic Example 5 was used instead of the polysiloxane (A-1) and the amount of acetic acid was changed to 3.4 g. Pieces of cloth were similarly treated and tested for softness, home laundering test and yellowing. The results are shown in Table 3.
Softness:
Three experts of a panel touched the treated cloth with hands and rated for softness. It was rated “O” for good, “Δ” for somewhat unacceptable, and “X” for unacceptable.
Wash-fastness:
Before and after the treated cloth was washed 10 times under the same conditions, it was examined for water repellency. It was rated “O” for good, “Δ” for somewhat unacceptable, and “X” for unacceptable.
Yellowing:
Relative evaluation of yellowness was made by measuring b value by means of a differential colorimeter ZE2000 (Nippon Denshoku Kogyo K. K.). The treated cloth was rated “O” for good with little yellowing and “Δ” for poor with noticeable yellowing.
TABLE 3
Softness
home
N-containing
Panelist
Panelist
Panelist
launder-
Yellow-
polysiloxane
A
B
C
ing test
ing
Example 1
(A-1)
◯
◯
◯
◯
◯
Example 2
(A-2)
◯
◯
Δ
Δ
◯
Com-
(A-5)
Δ
Δ
Δ
X
Δ
parative
Example 1
Example 3
To 300 g of the nitrogen atom-containing polysiloxane (A-6) synthesized in Synthetic Example 6 was added 50 g of polyoxyethylene tridecyl ether (amount of ethylene oxide added=10 mol, HLB=13.6). After mixing, 100 g of deionized water was added to the mixture, which was agitated at a high speed for 15 minutes by a homomixer for effecting phase inversion. Further, 550 g of deionized water was added to the mixture, which was agitated at 2,000 rpm for 15 minutes by the homomixer for effecting dilution, yielding a clear micro-emulsion. The solution was further diluted with deionized water to a 68-fold volume, providing a test solution.
A treating solution was prepared by adding 147.8 g of deionized water to 2.2 g of the emulsion. Pieces of polyester/cotton mixed (50%/150%) broadcloth (for softness evaluation) and fluorescent dye-treated cotton broadcloth (for yellowing evaluation) were dipped in the test solution for 2 minutes, nipped through rolls at a nip rate of 100%, dried at 100° C. for 2 minutes, and heat treated at 150° C. for 2 minutes, obtaining treated cloth pieces. For yellowing evaluation, the cloth pieces were further heat treated at 200° C. for 2 minutes.
The treated cloth pieces were evaluated for softness and yellowing according to the criteria shown above. They were also evaluated for home laundering test according to the criterion shown below. The results are shown in Table 4.
Comparative Example 2
A test solution was prepared as in Example 6 except that the nitrogen atom-containing polysiloxane (A-7) synthesized in Synthetic Example 7 was used instead of the polysiloxane (A-6). Pieces of cloth were similarly treated and tested for softness, home laundering test and yellowing. The results are shown in Table 4.
Home Laundering Test:
The treated cloth was washed once under the same conditions. Three experts of a panel examined the cloth for softness. It was rated “O” for good, “Δ” for somewhat unacceptable, and “X” for unacceptable.
TABLE 4
Softness
Home laundering test
N-containing
Panelist
Panelist
Panelist
Panelist
Panelist
Panelist
Yellow-
polysiloxane
A
B
C
A
B
C
ing
Example 3
(A-6)
◯
◯
◯
◯
◯
Δ
◯
Comparative
(A-7)
Δ
Δ
Δ
Δ
Δ
X
Δ
Example 2
Synthetic Example 8
A 500-ml glass flask equipped with a mechanical agitator blade, ester adapter, condenser and thermometer was charged with 275.9 g (0.080 mol) of α,ω-dihydroxy-dimethylpolysiloxane represented by the following average structural formula (xii) as component (A) and 8.9 g (0.040 mol) of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane as component (C). In a nitrogen stream, reaction was effected at 120° C. for 8 hours. In the ester adapter, the distillate of methanol resulting from methanol-removing reaction was observed, and a viscosity rise of the reaction solution was also observed. At the end of reaction, there was obtained a viscous colorless clear oily product. The product was subject to structural identification by 29 Si-NMR. The NMR chart is as shown in FIG. 2, with attribution shown in Table 5.
TABLE 5
Chemical
shift
Number of silicone
(ppm)
atoms by integration ratio
Attribution
−14.1
2.0
−22.4
94.0
−59.2
1.0
From the analytical results and the reaction route, the product was identified to have the following average structural formula (xiii). The measurements of volatile content and rotational viscosity are shown in Table 8.
Synthetic Example 9
A 500-ml glass flask equipped with an ester adapter, condenser and thermometer was charged with 275.9 g (0.080 mol) of α,ω-dihydroxydimethylpolysiloxane represented by the above average structural formula (xii) as component (A) and 8.9 g (0.040 mol) of N-β-(aminoethyl)-γ-aminopropyl-trimethoxysilane as component (C). In a nitrogen stream, reaction was effected at 120° C. for 8 hours. In the ester adapter, the distillate of methanol resulting from methanol-removing reaction was observed, and a viscosity rise of the reaction solution was also observed. Then, 16.5 g (0.080 mol) of γ-aminopropylmethyldimethoxysilane was added to the reaction solution, whereupon reaction was effected at 120° C. for 10 hours in a nitrogen stream. At the end of reaction, there was obtained a viscous colorless clear oily product. The product was subject to structural identification by 29 Si-NMR. It was identified to have the following average structural formula (xiv). The measurements of volatile content and rotational viscosity are shown in Table 8.
Synthetic Example 10
The procedure of Synthetic Example 8 was repeated except that 289.6 g (0.084 mol) of α,ω-dihydroxy-dimethylpolysiloxane and 14.0 g (0.063 mol) of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane were used. At the end of reaction, there was obtained a viscous colorless clear oily product (A-8). The product was subject to structural identification by 29 Si-NMR. The NMR chart is as shown in FIG. 3, with attribution shown in Table 6.
TABLE 6
Chemical
shift
Number of silicone
(ppm)
atoms by integration ratio
Attribution
−15.0
2.0
−22.4
188.0
−59.1
3.0
From the analytical results and the reaction route, the product was identified to have the following average structural formula (xv). The measurements of volatile content and rotational viscosity are shown in Table 8.
Synthetic Example 11
The procedure of Synthetic Example 10 was repeated except that 11.3 g (0.063 mol) of γ-aminopropyltrimethoxy-silane was used instead of N-β-(aminoethyl)-γ-aminopropyl-trimethoxysilane and reaction was effected at 120° C. for 16 hours. At the end of reaction, there was obtained a viscous colorless clear oily product. The product was subject to structural identification by 29 Si-NMR. The NMR chart is as shown in FIG. 4, with attribution shown in Table 7.
TABLE 7
Chemical
shift
Number of silicone
(ppm)
atoms by integration ratio
Attribution
−14.3
2.0
−22.5
188.0
−59.2
3.0
From the analytical results and the reaction route, the product was identified to have the following average structural formula (xvi). The measurements of volatile content and rotational viscosity are shown in Table 8.
Synthetic Example 12
The procedure of Synthetic Example 8 was repeated except that 9.9 g (0.040 mol) of 3-piperazinopropyl-trimethoxysilane was used instead of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane and reaction was effected at 120° C. for 12 hours. At the end of reaction, there was obtained a viscous colorless clear oily product. The product was subject to structural identification by 29 Si-NMR. The product was identified to have the following average structural formula (xvii). The measurements of volatile content and rotational viscosity are shown in Table 8.
Synthetic Example 13 (Comparison)
The procedure of Synthetic Example 8 was repeated except that 8.3 g (0.040 mol) of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane was used instead of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane. At the end of reaction, there was obtained a viscous colorless clear oily product. A viscosity rise as in Synthetic Example 8 did not occur. The product was subject to structural identification by 29 Si-NMR, finding that the number of silicon atoms per molecule was 65, which indicated incomplete reaction. The measurements of volatile content and rotational viscosity are shown in Table 8.
TABLE 8
SE
SE
SE
SE 13
SE 8
SE 9
10
11
12
(Comparison)
Volatile content @
0.3
0.3
0.3
0.4
0.3
0.6
105° C./3 hr (%)
Viscosity (cp)
365
325
893
342
340
133
Average number of
95
97
195
95
93
65
silicon atoms per
molecule
Synthetic Example 14
A 1000-ml glass flask equipped with a mechanical agitator blade, ester adapter, condenser and thermometer was charged with 401.6 g (0.20 mol) of α,ω-dihydroxy-dimethylpolysiloxane represented by the following average structural formula (xviii) as component (A) and 22.2 g (0.10 mol) of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane as component (C). In a nitrogen stream, reaction was effected at 120° C. for 8 hours. In the ester adapter, the distillate of methanol resulting from methanol-removing reaction was observed. At the end of reaction, the reaction mixture was cooled to 80° C., to which 40 g of isopropyl alcohol and 104.4 g (0.30 mol) of an epoxy compound represented by the following average structural formula (xix) were added whereupon reaction was effected at 80° C. for 8 hours. By stripping under a vacuum of 5 mmHg at 120° C. for 2 hours, a colorless clear oil having a viscosity of 310 cp was collected. The oil was analyzed by 1 H-NMR, finding that all the epoxy groups had reacted. Upon structural analysis by 29 Si-NMR, the oil was identified to have the following average structural formula (xx).
Synthetic Example 15 (Comparison)
A 2000-ml glass flask equipped with a reflux condenser and thermometer was charged with 1423.7 g (19.2 mol) of octamethylcyclotetrasiloxane and 32.1 g (0.20 mol) of 1,3,5,7-tetra[N-β-(aminoethyl)-γ-aminopropyl]-1,3,5,7-tetramethylcyclotetrasiloxane. In a nitrogen stream, the contents were dried at 120° C. for 2 hours. Then 20.6 g (0.10 mol) of N-β-(aminoethyl)-γ-aminopropylmethyldimethoxysilane and then 1.08 g (0.0020 mol) of a catalyst represented by the following average structural formula (xxi) were added to the flask. Reaction was effected at 150° C. for 6 hours for polymerization. At the end of polymerization, the reaction mixture was cooled to 90° C. Ethylene chlorohydrin, 3.22 g (0.040 mol), was added to the reaction mixture whereupon reaction was effected at 90° C. for 2 hours for neutralization. At the end of reaction, there was obtained a viscous, colorless, clear oily product (A-9), which was subject to structural identification by 29 Si-NMR. The product was identified to have the following average structural formula (xxii).
Example 4
To 150 g of the nitrogen atom-containing polysiloxane (A-8) synthesized in Synthetic Example 10 was added 90 g of polyoxyethylene tridecyl ether (amount of ethylene oxide added=10 mol, HLB=13.6). After mixing, 160 g of deionized water was added to the mixture, which was agitated at a high speed for 15 minutes by a homomixer for effecting phase inversion. Further, 600 g of deionized water was added to the mixture, which was agitated at 2,000 rpm for 15 minutes by the homomixer for effecting dilution, yielding a milky white emulsion.
To the emulsion was added 5.69 g of acetic acid, followed by thorough agitation and heat treatment at 80° C. for 4 hours. A clear micro-emulsion was obtained. The emulsion was further diluted with deionized water to a 100-fold volume, providing a test solution.
Pieces of polyester/cotton mixed (50%/50%) broadcloth and cotton broadcloth were dipped in the test solution for 1 minute, nipped through rolls at a nip rate of 100%, dried at 100° C. for 2 minutes, and heat treated at 150° C. for 2 minutes, obtaining treated cloth pieces. The softness of polyester/cotton mixed broadcloth and the wash-fastness of cotton broadcloth were evaluated according to the criteria shown below. The results are shown in Table 9.
Comparative Example 3
A test solution was prepared as in Example 4 except that the nitrogen atom-containing polysiloxane (A-9) synthesized in Synthetic Example 15 was used instead of the polysiloxane (A-8). Pieces of cloth were similarly treated and tested for softness and home laundering test. The results are shown in Table 9.
Softness:
Three experts of a panel touched the treated cloth with hands and rated for softness. It was rated “O” for good, “Δ” for somewhat unacceptable, and “X” for unacceptable.
Home Laundering Test:
Before and after the treated cloth was washed 10 times under the same conditions, it was examined for water repellency. It was rated “O” for good, “Δ” for somewhat unacceptable, and “X” for unacceptable.
TABLE 9
Home
laundering
Softness
test
N-containing
Panelist
Panelist
Panelist
After
polysiloxane
A
B
C
Initial
washing
Example 4
(A-8)
◯
◯
◯
◯
Δ
Comparative
(A-9)
Δ
Δ
X
◯
X
Example 3
Japanese Patent Application Nos. 11-180093 and 11-180094 are incorporated herein by reference.
Although some preferred embodiments have been described, many modifications and variations may be made thereto in light of the above teachings. It is therefore to be understood that the invention may be practiced otherwise than as specifically described without departing from the scope of the appended claims. | 4y
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/684,828, filed Nov. 26, 2012, which is a continuation of U.S. Pat. No. 8,317,127, filed Jan. 10, 2012, which is a divisional application of U.S. Pat. No. 8,096,496, filed Dec. 8, 2008; and claims the benefit of U.S. Provisional Patent Application Ser. No. 61/014,960, filed Dec. 19, 2007, the disclosures of each being incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
[0002] This invention relates to a fluid-tight drip pan, and more specifically to a fluid-tight drip pan for the engine or transmission compartment of a helicopter.
BACKGROUND OF THE INVENTION
[0003] Larger helicopters, in general, have several features in common in a typical basic configuration or layout. For instance, a typical helicopter will have a cabin section rearward of the pilot's cockpit or flight deck and which is used to transport people, cargo or both. In addition, the helicopter will have an engine compartment which is located typically above and to the rear of the pilot's cockpit or flight deck, and above the cabin section. The engine compartment typically houses two primary components, at least one engine and a rotor transmission with a corresponding transmission housing.
[0004] Both the engine and the rotor transmission contain numerous fluids, such as petroleum-based lubricants, that are critical to the operation of the engine and the transmission. These fluids inevitably leak from various locations in the engine and the transmission during both the operation and storage of the helicopter. Because the engine compartment is generally oriented above the cabin section, any leaking fluids eventually seep or drip into the cabin section, unless proper sealing mechanisms are in place. The inflow of these leaking fluids spoil, stain or damage the cabin's interior materials such as seat covers and acoustic linings. In addition, the leaking fluids can severely damage or destroy sensitive electronic equipment that may be placed in the cabin section of a helicopter.
[0005] Moreover, the exterior of the helicopter around the engine and transmission compartment is not completely fluidtight, allowing fluid such as water to leak from these areas into the cabin with similar adverse effects.
[0006] During routine inspection and maintenance it is necessary to have both ready visual and physical access to portions of the engine or at least the rotor transmission. Such access is required to check critical fluid levels, to replace worn, damaged or depleted parts or filters, or to adjust mechanical systems. Typically, various access panels in or around the engine or transmission compartments provide the requisite openings to achieve ready access to the engine and the rotor transmission. In some helicopters, a forged or fixed airframe structure forms an access opening which is located below the rotor transmission housing and above the cabin section. The opening is thus accessible through the cabin's ceiling. This access opening, however, must be sealed by a cover against the inevitable oil and fluid drippings which the engine and the rotor transmission will produce, as well as against water leakage.
[0007] The access opening below the engine compartment in the prior helicopters, such as the BLACK HAWK® helicopter, made for the United States by Sikorsky Aircraft Company of Stratford, Conn., is defined by both the aircraft structural forgings and a flexible or yieldable downwardly-turned skirt which is riveted onto the helicopter's forged structure. The skirt is thin and many times more flexible relative to the helicopter's forged structure.
[0008] Prior drip pan designs attached a covering plate directly to the flexible skirt with a hollow seal sandwiched therebetween. One hollow seal used in prior designs resembled the flexible, hollow door seals used around car doors or refrigerator doors. However, the skirt contains surface aberrations, such as the protruding rivet heads from the rivets securing the skirt to the forged helicopter structure. When the seal engaged both the skirt and the rivet heads, it could be upset enough so that leakage occurred. Accordingly, the hollow seal traversing these aberrations while sandwiched between the skirt and the covering plate is unable to provide a suitable, consistent, long-term fluid seal. Moreover, flexing of the flexible skirt could also cause leakage.
[0009] Also, the geometry of the cover cannot be such that it protrudes significantly into the interior of the cabin section. Headroom in the cabin section typically is limited and any additional protrusion from the ceiling of the cabin section is undesirable. In addition, because weight is critical to the operation of any aircraft, heavy cover constructions are undesirable.
[0010] Other prior drip pan structures disclosed in U.S. Pat. Nos. 6,112,856; 6,216,823; 6,446,907 and Design Pat. No. D444,443, which are fully incorporated herein by this express reference, provided improvements and solutions to these difficulties. However, Sikorsky has now introduced its “M” Model BLACK HAWK® helicopter for which these prior structures are not readily adaptable due to a change in configuration of the skirt noted above.
[0011] In particular, while the prior drip pans provided a port for visual access to an oil filter, the port was offset from the filter, rendering it more difficult to see the filter from many viewing angles through the port, also requiring specially shaped tools to manipulate filter retention bolts and requiring tilting of filters when removed or replaced.
[0012] The “M” model is currently in the process of introduction by Sikorsky for use by U.S. Military. In that model, and in other aircraft with what are or will be similarly-shaped skirts, there is still a skirt as disclosed in the prior U.S. Pat. No. 6,446,907 with the exception that in the access area or corner for the filter, the corner of the skirt has been pulled outwardly to allow direct and straight-through access to the filter and its filter retention bolts where the pan is removed. Such direct access is preferable as it eliminates the need for the special dog-bone shaped tools necessary to operate the filter retention bolts to remove and install the filter as was required with the prior drip pan, which not only required such tools but also required the filter to be “tipped” as it was removed or replaced and before it could be seated (see FIG. 6 of U.S. Pat. No. 6,446,907). Accordingly, in the new “M” model, one corner of the old prior skirt has been pulled or extended outwardly and asymmetrically to the other corners.
[0013] Stated in another way, the radius point or center of the expanded corner curve of the skirt has been moved outwardly from its position in the prior drip pan and the straight sides of the skirt are no longer tangent to the curve of this corner.
[0014] Such modification of the skirt renders the prior symmetric frame and drip pan incompatible with the new “M” model air frame. There is or would be a gap between the new skirt at the expanded corner and the old drip pan and drip pan frame. Accordingly, there is no way for the old drip pan and frame structure of the prior patents, including U.S. Pat. No. 6,446,907, to provide sealing for the new “opened” corner defined by the new skirt to allow more direct access to the filter.
[0015] In order to overcome this problem, the old frame and drip pan could be re-shaped to the new skirt shape, however, the requirement to seal the pan peripherally to the frame in such a case would require extensive and expensive re-working of the peripheral seal structure of the pan. In particular, the pan would require a special seal seat groove to be milled or otherwise manufactured into the edge of the pan.
[0016] Specifically, since the straight skirt sides extend in a direction intersecting with, and are no longer tangent to, the skirt curve at this corner, the skirt takes on inwardly-facing convex shapes, directed inwardly of the access opening, before flowing into the new expanded inwardly-facing concave corner. This skirt configuration would require a cooperative configuration of the drip pan whose cover would follow that of the skirt. When a drip pan for a corresponding frame is so shaped, the peripheral o-ring sealing the drip pan to the frame cannot be used as with the prior o-ring groove due to the changed configuration of the sealing surfaces. When stretched to fit, the o-ring on the drip pan would not follow this curved portion of the pan because it would span across the corresponding outwardly-facing concave drip pan curves. Thus, the fit of the o-ring would render installation of the pan to the frame problematical and adversely affect the desired seal.
[0017] In other words, the spanning o-ring would interfere with the corresponding inwardly-facing convex curve of the frame when the pan was inserted therein. This would, in turn, require the provision of a much more expensive and complicated o-ring retaining groove in the peripheral edge of the removable pan.
[0018] Moreover, the aforesaid problem of visual access to the filter through the corresponding site port has remained a problem. It is desired to enhance the location of the port to facilitate more visual access to the filter and to its “bypass button” from more viewing locations. The retention of the prior site port in its same position relative to the old drip pan, however, would retain the visual disadvantages mentioned.
[0019] Accordingly, it is one objective to provide an improved leak-proof drip pan apparatus for use in “M” model BLACK HAWK® helicopters.
[0020] A further objective of this invention is to provide an improved cover and seal for the interior access opening of helicopters such as the BLACK HAWK® “M” model helicopter and those of similar structure.
[0021] Another object of this invention is to provide a drip pan that will effectively and consistently seal fluid from passage from an engine or transmission compartment to a cabin section of a BLACK HAWK® “M” model helicopter and similar air frames.
[0022] Another object of this invention is to provide a drip pan which permits quick visual and physical access to the engine or transmission compartment of a BLACK HAWK® “M” model helicopters and similar helicopters without requiring modification to the existing aircraft structure.
[0023] Another objective of the invention is to more effectively seal a drip pan to the skirt defining a transmission access opening in a BLACK HAWK® “M” model helicopters and similar helicopters.
[0024] Still another object of this invention is to provide a drip pan that can be attached to the existing structure of a BLACK HAWK® “M” model helicopter and similar helicopters without modification of the existing airframe structure and with minimal intrusion into the helicopter's cabin section.
[0025] Another objective of the invention is to provide an improved drip pan for use with BLACK HAWK® “M” model helicopter and similar air frames using an o-ring seal between drip pan and frame, where all peripheral curves in the pan are convex (i.e., outwardly directed) with respect to the pan.
[0026] Yet another objective of the invention is to provide enhanced visual access to a filter in an “M” model BLACK HAWK® helicopter.
SUMMARY OF THE INVENTION
[0027] In other features and functions, the new helicopter drip pan apparatus herein covers and effectively seals a structural opening in the helicopter without leakage.
[0028] To these ends, in one embodiment, a drip pan is adapted to cooperate with a frame having an inwardly-facing peripheral surface. The frame is secured to a depending skirt which defines the structural access opening for access to a rotor transmission of a BLACK HAWK® Model “M” helicopter. The access opening also provides access to components, such as an oil filter, attached to the rotor transmission.
[0029] The drip pan comprises a member having an outwardly-facing peripheral surface. The outwardly-facing peripheral surface is adapted to cooperate with the inwardly-facing peripheral surface of the frame and defines a first pan corner and at least one other pan corner. The first pan corner differs in curvature from the other pan corner. In one embodiment, the member is removably received within the frame in a single orientation. In one embodiment, the first pan corner is defined by a first pan corner radius and the other pan corner is defined by a pan corner radius that is larger than the first pan corner radius.
[0030] In one embodiment, a helicopter has an access opening defined by a depending skirt having at least two straight sides connected by a corner. The corner is defined by an inwardly oriented concave curve such that an extension of the concave curve intersects an extension of at least one straight side at an angle greater than zero degrees. The drip pan apparatus comprises a drip pan and a frame. The frame is configured to cooperate with the skirt, including the inwardly oriented concave curve. The frame comprises an inwardly-facing first frame corner defined by a first frame corner radius, and at least one other inwardly-facing frame corner defined by a frame corner radius that is greater than the first frame corner radius. The drip pan cooperates with the frame and comprises a first pan corner defined by a first pan corner radius that is configured to cooperate with the first frame corner, and at least one other corner defined by a pan corner radius that is greater than the first pan corner radius. The at least one other pan corner is configured to cooperate with the at least one other inwardly-facing frame corner.
[0031] In one embodiment, a drip pan apparatus for covering and sealing the helicopter transmission access opening in a helicopter comprises a drip pan and a frame adapted to mount to the helicopter transmission access opening. The frame has an inwardly-facing peripheral surface extending around the frame. The inwardly-facing peripheral surface has a first frame corner defined by a first frame corner shape and at least one other frame corner defined by a frame corner shape that differs from said first frame corner shape. The drip pan has an outwardly-facing peripheral surface extending around the drip pan. The outwardly-facing peripheral surface has a first pan corner defined by a first pan corner shape and at least one other drip pan corner defined by a drip pan corner shape that differs from the first pan corner shape. The first pan corner cooperates with the first frame corner and the drip pan is configured to be selectively affixed to the frame. A seal member is operably disposed between the outwardly-facing peripheral surface and the inwardly-facing peripheral surface when said drip pan is affixed to the frame.
[0032] In one embodiment, a drip pan is configured to cooperate with a frame secured to a depending skirt, which defines an access opening for access to a rotor transmission of a helicopter. The frame has an inwardly-facing peripheral surface of asymmetrical shape. The drip pan comprises a member having an outwardly-facing peripheral surface of asymmetrical shape operably corresponding to the asymmetrical shape of the inwardly-facing peripheral surface of the frame. A resilient seal is disposed between the inwardly-facing peripheral surface and the outwardly-facing peripheral surface when the member is operably disposed in the frame for sealing the member to the frame, about the peripheral surfaces.
[0033] In one embodiment, a drip pan apparatus for a rotor transmission access opening in a helicopter comprises a drip pan having a peripheral edge for fitting in the opening. The edge is defined in part by a plurality of corners, one of which is developed about a radius of smaller extent than the radii of the other corners in the plurality.
[0034] This configuration is attained despite and contrary to the previously conventional wisdom than an o-ring seal could not be used effectively about and around the relatively small radius of the pan corner. According to conventional wisdom, placing the o-ring seal about such a small radius would result in undue stretch of the o-ring. The belief was that the resulting reduction in diameter of the o-ring would, in turn, result in seal efficiency derogation or other seal failure. Contrary to this belief, embodiments of the pan apparatus do not result in a stretched o-ring and, furthermore, do not require the o-ring to fit into any concave areas extending into the pan to avoid an otherwise interference fit between the o-ring and frame upon pan insertion.
[0035] These and other objectives and advantages will become readily apparent from the following description of embodiments of the invention and from the drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIGS. 1-6 are reproduced herein from the prior U.S. Pat. No. 6,446,907 for clarity of contrast to the present invention and are described in that patent;
[0037] FIG. 7 is an exploded isometric view of components of the new drip pan apparatus according to one embodiment of the invention;
[0038] FIG. 8 is a plan view of the drip pan of FIG. 7 as will be viewed from the cabin section of a helicopter when in use;
[0039] FIG. 9 is an enlarged view of the new corner structure according to one embodiment of the invention in the upper left-hand corner of FIG. 8 but illustrating the prior art access port in phantom for comparison;
[0040] FIG. 9A is a cross-sectional view of the corner structure in FIG. 9 , but illustrating the prior art skirt in phantom for comparison;
[0041] FIG. 9B graphically illustrates the new frame of the apparatus contrasted with the old skirt and old pan corner orientation;
[0042] FIG. 10 is a cross-sectional view taken along lines 10 - 10 of FIG. 8 ;
[0043] FIG. 11 is an exploded cross-sectional view similar to FIG. 10 but showing the port cover removed and illustrating the replacement of a filter through the port; and
[0044] FIG. 12 is an isometric view of the new drip pan (with port covers not shown for clarity) from the perspective of the transmission side of the new drip pan when in use.
PRIOR ART
[0045] Applicant first describes the prior art as in U.S. Pat. No. 6,446,907 for purposes of environment background and contrast with the invention. Item numbers shown in FIGS. 2-6 when used on FIGS. 7-12 designate components in FIGS. 7-12 which are similar or identical to components in FIGS. 2-6 .
[0046] FIG. 1 shows a widely known configuration of a typical helicopter 10 . While the typical helicopter 10 , for example, in this prior description was a BLACK HAWK® helicopter as manufactured for the United States by Sikorsky Aircraft Company, Stratford, Conn., it will be appreciated that the drip pan structure described in the prior patents was useful in numerous aircraft and helicopter configurations of other prior makes and models. In this configuration the helicopter 10 had a cabin 12 (dashed outline) in which passengers, equipment and cargo could ride during operation. Located just above the cabin 12 was at least one engine 14 which supplied power to a rotor transmission 16 . The rotor transmission 16 was connected to a shaft 18 which imparted rotary motion to the main rotor 20 . The rotor transmission 16 was also connected via a drive shaft (not shown) to a tail rotor 22 .
[0047] The rotor transmission 16 required frequent inspection and maintenance to ensure proper operation of the transmission. To facilitate easy and ready access to the rotor transmission, rotor transmission access openings were provided on both the exterior and interior of the helicopter. For example, structural opening 24 was located within the cabin 12 , providing the requisite access to the rotor transmission 16 situated directly above the cabin 12 . Structural opening 24 generally had some type of removable covering to seal the transmission area 16 from the cabin area 12 . To accommodate attachment of a removable covering, a flexible skirt 26 ( FIG. 2 ) was fixedly secured around the periphery of structural opening 24 by rivets 28 . Skirt 26 was many times more flexible than the structural opening 24 to which it attached.
[0048] As can be further appreciated the rotor transmission 16 as well as the engine 14 required various fluids during their respective operations. Generally, these fluids provided the rotor transmission 16 and the engine 14 with lubrication, cooling, and the like. During operation these fluids may leak and drip from either the engine 14 or rotor transmission 16 or both. To prevent leakage of fluid into the cabin 12 via structural opening 24 , a drip pan apparatus 30 , as shown in FIG. 2 , was used to cover and seal the structural opening 24 .
[0049] With specific reference to FIGS. 2-6 , the drip pan apparatus 30 according to one preferred embodiment of the prior structure had a frame member 32 , a drip pan 34 , and a seal member 36 cooperating together to provide a fluid tight sealing arrangement for structural opening 24 . Frame member 32 had a plurality of lugs 38 disposed about the exterior periphery of frame member 32 . Four lugs 38 were disposed on two sides of the frame member 32 and three lugs 38 were disposed on the other two sides of the frame member 32 . Fasteners 40 cooperated with lugs 38 and threaded retention members 42 ( FIG. 4 ) to secure frame member 32 to skirt 26 attached to structural opening 24 . Once installed, frame member 32 typically remained in place and was not routinely removed from structural opening 24 , although it could be readily removed by simply extracting fasteners 40 . Frame member 32 was many times more rigid than the flexible skirt 26 .
[0050] Drip pan 34 had a plurality of resilient members 50 which serve to hold drip pan 34 in sealing engagement with frame member 32 . Each resilient member 50 had elongated arms 52 with curved portions 54 . Resilient members 50 were free to pivot about brackets 58 . Curved portions 54 selectively engaged slots 56 opening toward and located about the interior periphery of frame member 32 . To secure drip pan 34 to frame member 32 , the drip pan 34 was pushed into the interior of frame member 32 until the drip pan 34 contacted lip 60 ( FIG. 4 ) which extended around frame member 32 and acted as a stop for drip pan 34 . Only part of the curved portions 54 were resiliently inserted into slots 56 . The installation and the removal of the drip pan 34 was accomplished rather quickly using the resilient members 50 because no tools such as screwdrivers or wrenches were required. Equally important, resilient members 50 were permanently secured to the drip pan 34 by brackets 58 , so the resilient members 50 could not be lost or misplaced when the drip pan 34 was removed to gain full access to the engine 14 and rotor transmission 16 .
[0051] As shown in FIG. 4 , seal member 36 was disposed in an outwardly-facing groove 62 which extended around the outer periphery of drip pan 34 . In that application, the term “outwardly-facing” represents a direction substantially parallel to the plane of the drip pan 34 and extending away from the drip pan 34 . As illustrated in FIG. 2 , the outer periphery of drip pan 34 , which had four straight edges or sides 35 a , 35 b , 35 c , 35 d connected by curved portions 37 a , 37 b , 37 c , 37 d , conformed to frame member 32 which was comprised of four straight sides or rails 39 a , 39 b , 39 c , 39 d connected by curved portions 41 a , 41 b , 41 c , 41 d (shown in FIG. 3 ). With reference to FIGS. 5 and 6 , when drip pan 34 was installed into frame member 32 , seal member 36 sealingly engaged inwardly-facing surface 64 of frame member 32 to achieve a fluid tight sealing arrangement between drip pan 34 and the frame member 32 . In this application, the term “inwardly-facing” represented a direction substantially parallel to the plane of the frame member 32 and extending toward the interior of the frame member 32 and the pan 34 . Unexpectedly, seal member 36 provided the necessary sealing engagement between outwardly-facing seal member 36 and inwardly-facing surface 64 despite the fact that groove 62 and surface 64 respectively ran along straight sides 35 a , 35 b , 35 c , 35 d and 39 a , 39 b , 39 c , 39 d . Typically, peripheral o-ring seals were used in cooperation with annular or curved sealing surfaces such as those defined by curved portions 37 a , 37 b , 37 c , 37 d and 41 a , 41 b , 41 c , 41 d (shown best in FIGS. 2 and 3 ). It was previously felt that peripheral seals used along straight sealing surfaces would provide unacceptable sealing integrity.
[0052] In one prior drip pan design, a seal was located in a groove opening extending in a direction perpendicular to the plane of the drip pan. The seal would engage a surface which was parallel to the plane of the dip pan. With this arrangement, flexure of the helicopter frame associated with structural opening 24 may breach the seal integrity between the drip pan and the attachment frame causing fluid to leak into the helicopter cabin. Seal member 36 of these FIGS. 2-6 , however, was a peripheral seal located in outwardly-facing groove 62 to form a fluid seal between the periphery of the drip pan 34 and the inwardly-facing surface 64 of frame member 32 . With this arrangement, flexure of the helicopter frame associated with structural opening 24 did not breach the integrity of the sealing arrangement between the drip pan 34 and the frame member 32 . While the sealing member 36 could be any suitable cross-sectional geometry, seal member 36 was preferably an O-ring.
[0053] Routine maintenance and inspection of the rotor transmission 16 , does not ordinarily require removal of the entire drip pan 34 . As shown in FIG. 2 , to accommodate limited access for routine maintenance or inspection, or filter replacement, a plurality of small, removable access port covers 70 were provided in drip pan 34 to allow access through access openings or ports 72 to mechanical linkages in and around the rotor transmission and to allow inspection of the fluid levels associated with the rotor transmission 16 . An access cover 70 for each access opening 72 was removably disposed in sealing engagement covering the access opening 72 . To secure access cover 70 to the access opening 72 in drip pan 34 , each access cover 70 had a resilient member 74 which functioned much like resilient member 54 which secured the drip pan 34 to the frame member 32 .
[0054] With reference particularly to FIGS. 5 and 6 , access opening 72 had an annular groove 76 for resiliently receiving curved portion 78 of resilient member 74 to sealingly secure access cover 70 to access opening 72 . Advantageously, no tools were required to operate the resilient members 74 to install or remove the access covers 70 . In addition, brackets 80 permanently secured resilient member 74 to access covers 70 so resilient members 74 could not be lost or misplaced. Each access cover 70 was attached to the drip pan 32 by a suitable attachment device such as a cable or chain 82 so when an inspection procedure was complete the access cover 70 was readily retrieved and positioned into access opening 72 . Each access cover 70 included a seal member 84 disposed in an annular groove 86 extending around the outer periphery of access cover 70 . When access cover 70 was placed into access opening 72 , seal member 84 sealing engaged surface 88 of drip pan 34 which formed part of access opening 72 . Like seal member 36 , seal member 84 formed a peripheral seal between the access cover 70 and the surface 88 . This arrangement improved on prior sealing arrangements which located the seal member between an access cover surface parallel to but outside of the plane of the access cover 70 and the drip pan 32 , i.e., a face seal. As discussed above, the peripheral seal arrangement provided improved seal integrity even if the drip pan 34 flexed. Preferably, seal member 84 was an O-ring.
[0055] To facilitate the removal of accessing covers 70 from access openings 72 , pull handles 90 were attached to access covers 70 . Fasteners 92 fixedly secured pull handles 90 to access covers 70 . Preferably, pull handles 90 were cable or chain.
[0056] During the preflight procedure of a helicopter, critical filters must be checked and determined operational before the helicopter is allowed to fly. To facilitate this inspection process, at least one of the access or port covers 70 had a transparent cover member 94 ( FIG. 5 ) so that a bypass button or valve associated with a particular filter could be checked visually through the access cover 70 without physically removing the access cover 70 from the access opening or port 72 . A seal member 96 was disposed between the transparent cover member 94 and access cover 70 to prevent fluid leakage therebetween. Preferably, the transparent cover member 94 was made from acrylic such as Plexiglass™.
[0057] With reference to FIGS. 2-4 , drip pan 34 had a drain hole 100 to drain fluid collected by the drip pan 34 . Drain hole 100 included strainer members 102 (shown in FIG. 4 ) to keep foreign objects coming to rest on the drip pan 34 from clogging the drain hole 100 . A drain tube 104 was attached to the drain hole 100 to direct the collected fluid to a catch basin (not shown) or to the exterior of the helicopter. The drain tube 104 was made preferably from metal tubing having a diameter of about 0.625 inches. Alternatively, a removable stopper could have been used with drain hole 100 for selective drainage.
[0058] In at least one application, as depicted in FIGS. 3 and 4 , the drip pan apparatus 30 could have been used on helicopters having carrousel bars added to the interior of the helicopter cabin 12 (shown in FIG. 1 ) to support, for example, litters used for transporting patients in need of medical attention. Typically, at least one carrousel bar passed directly under the drip pan apparatus 34 . To accommodate a carrousel bar 108 (phantom), elongated recesses 110 were provided in frame member 32 so that the frame member 32 did not interfere with the installation and operation of the carrousel bar 108 .
[0059] In still another application, the drip pan apparatus 30 , and more specifically the frame member 32 , could have interfered with access to an oil filter associated with the rotor transmission 16 when the drip pan apparatus 30 is installed. To provide for removal of an oil filter 112 ( FIG. 6 ) from the rotor transmission 16 , a portion of frame member 32 was machined away as shown by numeral 114 so that the oil filter 112 could be removed along a line not perpendicular to the drip pan apparatus 30 . During the removal or installation of oil filter 112 , the drip pan 34 was removed to provide even greater access to the oil filter 112 . Frame member 34 was machined just enough to permit removal of oil filter 112 , and maintain sealing engagement between seal member 36 and surface 64 of frame member 34 .
[0060] To provide further access to the oil filter 112 , the geometry of frame member 32 could be modified. More specifically and with reference to FIG. 3 , frame member 32 was comprised of four straight sides or rails 39 a , 39 b , 39 c , 39 d connected by curved portions 41 a , 41 b , 41 c , 41 d , where each rail 39 a , 39 b , 39 c , 39 d had a respective width indicated by W 1 , W 2 , W 3 , W 4 . To provide improved access to the oil filter 112 (shown in FIG. 6 ), the opening defined by rails 39 a , 39 b , 39 c , 39 d was shifted to the left in FIG. 3 such that the respective widths W 1 , W 2 , W 3 , W 4 of rails 39 a , 39 b , 39 c , 39 d were not all equal to one another. Preferably, the difference between W 2 and W 4 was about one quarter of an inch. This transverse shift of the opening helped to accommodate removal of the oil filter 112 which was generally located in the compartment above the drip pan apparatus 30 near the upper left hand corner of the drip pan apparatus 30 shown in FIG. 3 .
[0061] Accordingly, the prior art disclosed above provided an improved cover and seal for the interior access opening of a helicopter such as the prior BLACK HAWK® helicopter models. As such, that drip pan apparatus sealed against fluid passage from the engine or transmission compartment to the cabin section of a prior model BLACK HAWK® helicopter. In addition, that drip pan apparatus permitted quick access to the engine or transmission compartment of that helicopter, without requiring modification to the existing aircraft structure.
[0062] The new invention described below provides the same features and advantages in a model “M” BLACK HAWK® helicopter, but also accommodates the new relieved skirt version of the new “M” model, providing more direct filter access, while still providing the desirable seal functions noted above.
DETAILED DESCRIPTION OF INVENTION
[0063] Embodiments of the invention described herein differ from that prior art of U.S. Pat. No. 6,446,907 (the '907 patent) in the structure of the elements defining the asymmetric corner components of a drip pan apparatus 200 shown in FIGS. 7-12 . In other aspects, such as in materials of construction and function, in one embodiment, the drip pan apparatus 200 of this invention is like that described in said patent. Accordingly, any item numbers found in FIGS. 7-12 which are the same as those in FIGS. 2-6 designate like components. Moreover, the helicopter 10 of FIG. 1 is similar in outward appearance to the “M” model BLACK HAWK® helicopter and for that reason is used herein to illustrate an overall helicopter environment in which the new drip pan apparatus 200 of FIGS. 7-12 is used.
[0064] Turning to FIG. 1 , there is shown therein a helicopter 10 representing generally for this invention a BLACK HAWK® Model “M” helicopter of the type made by the Sikorsky Aircraft Company of Stratford, Conn., and other helicopter air frames similar thereto. Like the prior BLACK HAWK® helicopter, the BLACK HAWK® “M” model helicopter has a cabin 12 and an engine or turbine 14 which powers a rotor transmission 16 . Shaft 18 transmits rotary motion to a rotor 20 while the transmission 16 is also connected by a drive element (not shown) to tail rotor 22 . Like the BLACK HAWK® helicopter, the BLACK HAWK® Model “M” helicopter has a fixed transmission access opening but designated 205 in FIG. 1 . The “M” model embodies a variety of other differences from the prior BLACK HAWK® helicopter of FIG. 1 of the '907 patent but in ways not relevant to this invention except as further described.
[0065] Turning now to FIG. 7 , the drip pan apparatus 200 has application for use in a “M” model BLACK HAWK® helicopter and other similar airframes having the fixed transmission access opening 205 defined by an air frame member 206 and a depending flexible skirt 207 attached thereto. Skirt 207 , like skirt 26 of FIG. 2 , is many times more flexible than air frame member 206 to which skirt 207 is attached. Skirt 207 of the BLACK HAWK® Model “M” helicopter has two straight portions 208 , 209 and an expanded corner 210 therebetween, as well as a remaining periphery defined by straight sections and corners. Note that skirt 207 , between straight portions 208 , 209 , forms two inwardly-facing convex curves 231 , 232 and an inwardly-facing concave curve 230 . The concave curve 230 is oriented inwardly at the corner 210 so that straight portions 208 , 209 flow into the curves 231 , 232 which are tangent to, or flow into, curve 230 . It will be appreciated that an extension of each straight portion 208 , 209 would intersect an extension of curve 230 at an angle greater than zero degrees. In this manner, the corner 210 of skirt 207 has been expanded outwardly of the location of the same corner of the prior skirt of the '907 patent.
[0066] In one embodiment of this invention, corner 210 is asymmetric to the other corners (not shown) of the skirt 207 , which other corners may remain in the same configuration. In other words, the corner 210 is defined by a shape that is different than the other corners of the skirt 207 . By contrast, in the access opening covered by the prior drip pans of the '907 patent all four corners of the prior skirt were symmetrical. As is described below, the drip pan apparatus 200 sealingly cooperates with the skirt 207 , including the corner 210 , to cover access opening 205 to prevent fluid drippings from entering the cabin 12 of the Model “M” BLACK HAWK® helicopter 10 .
[0067] To that end, and with continued reference to FIG. 7 , the drip pan apparatus 200 includes a frame 215 having a corner structure 216 , a drip pan 220 having a new corner 221 , and an o-ring seal 222 . In use, the frame 215 is secured to air frame member 206 . As shown, rivets 201 or other fasteners may secure the frame 215 to the skirt 207 and air frame 206 through tabs 202 . A flexible sealing media (not shown), such as PROSEAL™ (manufactured by PRC Desoto International, Inc. of Indianapolis, Ind., a PPG Company) or other sealant may be used to seal the frame 215 to skirt 207 when the frame 215 is secured to the air frame 206 .
[0068] Thereafter, drip pan 220 is inserted into the frame 215 in the position illustrated in FIGS. 7 and 8 , where seal member or o-ring 222 creates a peripheral seal between the drip pan 220 and frame 215 and provides continuous sealing during air frame flexure and without the disadvantage of any face seal in this regard. Attachment members 50 releasably secure the drip pan 220 to the frame 215 similarly to the prior pan of the '907 patent where elongated arm 52 with curved portions 54 selectively engage slots 56 . Once the pan 220 is inserted into the frame 215 , a drain line 104 may be connected to pass drainage fluids from drain 100 .
[0069] As set forth above, and with continued reference to FIG. 7 , the frame 215 accommodates the outward expansion of the skirt 207 at corner 210 . In particular, as is described in more detail below, corner structure 216 of frame 215 has been expanded outwardly to match the outward expansion of the skirt 207 , as shown. In addition, the radius of the inwardly-facing frame corner represented at 242 has been significantly reduced to correspond to a relatively small radius of corner 221 of drip pan 220 .
[0070] With reference to FIGS. 7 and 8 , the frame 215 comprises four straight sides or rails 247 a , 247 b , 247 c , 247 d connected by curved portions 249 a and 249 b , the corner structure 216 , and curved portion 249 c , respectively. The rails 247 a , 247 b , 247 c , 247 d ; the curved portions 249 a , 249 b , 249 c ; and the corner structure 216 collectively define the inwardly-facing peripheral surface 235 (shown in FIG. 7 ). Each rail 247 a , 247 b , 247 c , 247 d has a respective width indicated by W 5 , W 6 , W 7 , W 8 (labeled in FIG. 8 ) measured from the inwardly-facing peripheral surface 235 to an outer periphery of the frame 215 .
[0071] In one embodiment and with reference to FIG. 7 , the width of the corner structure 216 varies to accommodate the expansion of the skirt 207 , specifically the curve 230 , at corner 210 . The variation in the width of the corner structure 216 is shown in FIGS. 8 and 9A . As shown, the width of the corner structure 216 transitions from the width W 7 of rail 247 c to width W 8 of rail 247 d . In one embodiment, at least a portion of the corner structure 216 is wider than either adjacent rail 247 c or rail 247 d . Specifically, the width of the corner structure 216 at one location, for example at width W 9 or width W 11 may be greater than either width W 7 or width W 8 . By way of further example, as depicted in FIGS. 8 and 9A , the width of corner structure 216 may transition from width W 7 to width W 9 that is greater than width W 7 . The width of the corner structure 216 then decreases from width W 9 into an inwardly-facing frame corner 242 or width W 10 that is less than the width W 9 . Further, the width of the corner structure 216 then increases to width W 11 before transitioning to a narrower width W 8 of rail 247 d . It will be appreciated that the width of the corner structure 216 may vary smoothly from W 7 to W 8 .
[0072] Furthermore, to provide improved access to the filter F (shown in FIG. 11 ), the opening defined by rails 247 a , 247 b , 247 c , 247 d may be shifted to the left in FIG. 8 such that the respective width W 6 and width W 8 of rails 247 b and 247 d are not equal to one another. This transverse shift of the opening helps to accommodate removal of the filter which is generally located in the compartment above the drip pan apparatus 200 . It will be appreciated that widths W 5 , W 6 , W 7 , W 8 may not be equal to any of the widths W 1 , W 2 , W 3 , W 4 of FIG. 3 .
[0073] With regard to the pan 220 and with further reference to FIG. 7 , the pan 220 has an outwardly-facing peripheral surface 239 , which has four straight sides 250 a , 250 b , 250 c , 250 d connected by corners 211 , 212 , 213 , and corner 221 . The outwardly-facing peripheral surface 239 conforms to the inwardly-facing peripheral surface 235 . As set forth above, the radius of the corner 242 is significantly reduced to correspond to the radius of the corner 221 of the pan 220 . As shown in FIGS. 7 and 8 , the corner 221 is developed about a much smaller radius than its other pan corners 211 - 213 . It will be appreciated that the variation of the radius configuration of the corner 221 from the corners 211 - 213 simplifies installation of the pan 220 by preventing incorrect installation since the pan 220 may be inserted into the frame 215 in only one orientation.
[0074] Additionally, in one embodiment, the drip pan 220 defines a plurality of access ports 223 - 226 and a filter access port 228 , which is provided with a removable port cover 229 having a view window 236 and frame 237 . Once the drip pan 220 is secured to the frame 215 , the status of a filter or other component in or on the transmission may be viewed through the view window 236 . Also, any one or more of the access covers 70 may be removed from its respective access port 223 - 226 such that routine maintenance and inspection of components within access opening 205 may be performed. In one embodiment, the drip pan apparatus 200 differs from that pan apparatus of the prior '907 patent only in the area A as identified in FIG. 8 .
[0075] FIGS. 9, 9A, and 9B illustrate area A of FIG. 8 in greater detail. As shown in FIG. 9 , the extra material provided by expansion of the pan 220 out to the smaller radius corner 221 allows port 228 to be moved out toward the corner 221 and more directly under (when in use) a filter compared to the prior art port 72 (shown in phantom line). Thus positioned, the port 228 provides improved visual access to components on the transmission, such as the filter, and any indicator or “bypass button” thereon, indicating the operational status thereof. In other words, the indicator or button can be more easily viewed through filter access port 228 from more widely varied viewing positions than in the prior drip pan configuration.
[0076] Similarly, with respect to the prior art skirt and the new skirt 207 , the prior skirt is identified in phantom lines at 240 in FIG. 9A . In one embodiment of this invention, as described above, the new skirt 207 is expanded outwardly as shown in the solid lines at this corner to form 242 . The smaller radius corner 242 corresponds to small radius corner 221 of the pan 220 , shown in FIG. 9 . FIG. 9B graphically illustrates the comparison of the new frame 215 and the respective orientations of the old skirt 26 designated 240 and the old prior art pan corner 245 (both shown in phantom line).
[0077] With continued reference to FIG. 9B , in one embodiment, radius R 1 of the prior art pan corner 245 may be of greater length than the radius R 2 of corner 221 in the drip pan apparatus 200 , thereby allowing the filter access port 228 to be moved more directly in line with a filter. However, even though the radius of corner 221 is smaller, as shown in FIG. 7 , the o-ring seal 222 situated between the outwardly-facing peripheral surface 239 and the inwardly-facing peripheral surface 235 unexpectedly seals the drip pan apparatus 200 and prevents egress of fluids from access opening 205 .
[0078] With reference now to FIGS. 9A, 10, and 11 , in order for the frame 215 to cooperate with the skirt 207 and form a small radius at the corner 242 (shown in FIG. 7 ), the frame 215 may include an inner rim 218 and an outer rim 219 forming a trough 234 having a floor at 217 therebetween. Preferably, the rim 218 at corner structure 216 is at least partially expanded outwardly from its position in the prior pan to accommodate skirt 207 and form the corner 242 . Accordingly, trough 234 may vary in width “L” such that the width of corner structure 216 varies, as described above, as required about frame 215 to accommodate the concave curve 230 (shown in FIG. 7 ).
[0079] Furthermore, this corner structure at 216 will be appreciated by contrasting prior art FIGS. 5 and 6 with new FIGS. 10 and 11 . In FIGS. 10 and 11 , the frame 215 has been expanded at 217 to the length “L”. In prior FIGS. 5 and 6 , the frame was not so expanded. Thus, skirt 207 (at concave curve 230 ) has been moved significantly to the left as viewed in FIGS. 10 and 11 as compared to the prior frame. According to embodiments disclosed herein, a filter F ( FIG. 11 ) can advantageously be removed or inserted in a direction along and parallel to an elongated filter axis 204 when the removable port cover 229 is removed from the pan 220 .
[0080] If desired, in one embodiment, a trim ring (not shown) can be applied to aesthetically cover the frame 215 , leaving only drip pan 220 and the ports 223 - 226 , 228 clear for use or for overall removal of the drip pan 220 for access to the transmission 16 .
[0081] Moreover, and if desired, while o-ring 222 is shown in a simple, outwardly facing, parallel sided groove, other groove shapes capturing the o-ring 222 to the drip pan 220 (or alternatively to frame 215 ) may be used. It will also be appreciated that the scale of the figures such as in FIGS. 10 and 11 may be changed, such that o-ring 222 is actually in more of an oval or circular cross-section, or more of a squared configuration than as shown in these figures, and more like, for example, the cross-sectional configuration of peripheral seal 238 in FIGS. 10 and 11 .
[0082] With reference to FIGS. 7 and 12 , while the corners of the frame 215 and the pan 220 are drawn and referenced as being defined by radii, one skilled will appreciate that other shaped corners may be utilized. Even so, the corner 221 and the corner 242 are cooperatively shaped. The remaining corners of the pan 211 - 213 cooperate with their respective other corners (unlabeled) of the frame 215 . The shape at the corner 221 is, however, different than the shape of the corners at 211 - 213 . Thus, the pan 220 may be inserted into the frame 215 in only one orientation.
[0083] The drip pan 220 otherwise performs the same sealing and access functions for the “M” Model as in the prior BLACK HAWK® helicopter without requiring air frame modifications and without utilizing face seals to seal any of the ports 223 - 226 and 228 or to form the seal between the drip pan 220 and the frame 215 .
[0084] While the present invention has been illustrated by the description of embodiments thereof, and while the embodiments have been described in considerable detail, they are not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details and drawings shown and described. Accordingly, departures may be made from such details without departing from the scope of the general inventive concept. | 4y
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BACKGROUND OF THE INVENTION
This invention relates to the field of plastic containers. More specifically, it relates to the field of thin walled plastic containers used for liquids, such as water, milk, juice, detergents and the like. Frequently, such containers are formed by blow molding machinery. Such machinery introduces a tube of hot plastic between the faces of a mold. The mold faces are then closed and air is blown into the tube of plastic forcing it against the walls of the mold. Water cooling provided in the interior of the mold hardens the plastic in the shape of a container.
When the walls of the mold come together, some of the plastic is positioned beneath the mold area. This remains attached to the molded container by virtue of a narrow connective portion pinched between the walls of the mold. This excess material or tail flash is usually trimmed or severed from the container upon completion of the molding process.
Because the flash is not subjected to the same degree of cooling because of its mass, it remains hot after the container is freed from the mold. For the purpose of removing the flash the containers are positioned on their side and sent to an appropriate device for severing the flash. In standard containers of the type presently available the amount of plastic used to form each container is sufficient to insure that the tail flash is stiff enough that it does not flop over and touch the container when the containers are on their side. This is important because the flash is in a near molten state and will bond to the container and prevent the severing equipment from functioning properly.
In order to maintain plastic containers as an effective packaging medium, it is necessary to keep costs as low as possible and, where possible, further reduce costs. Todays plastic materials are sufficiently strong and ductile to be molded with very thin wall thicknesses. Thus, the materials presently available are capable of being formed into containers having wall thicknesses of 0.020 inches or less.
A problem encountered when extra thin walled containers are produced is that the amount of plastic in the tail flash is reduced in proportion to the reduction in wall thickness of the container. As a result, the tail flash is no longer sufficiently rigid to remain spaced away from the container and in the proper position for severing. In fact, it will rapidly flop over as the containers are turned on their side, engage and stick to the container bottom rendering the resulting container useless.
It is accordingly an object of the present invention to provide an improved mold and method whereby extra thin walled containers can be produced without interference from the tail flash sticking to the container bottoms.
It is another object of the invention to provide a mold for making extra thin walled containers having means for producing standoff projections in the tail flash and for cooling the projections so as to prevent sticking of the tail flash to the container prior to severing the flash therefrom.
A further object of the invention is to provide a method for molding extra thin walled containers such that the tail flash is positively maintained spaced from and at a predetermined angular orientation with respect to the bottom of the molded container.
A further object of the invention is to provide a method and apparatus permitting the manufacture of extra thin walled plastic containers having wall thicknesses of 0.020 inches or less.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a composite schematic view illustrating the essential steps in the formation of blow molded plastic containers.
FIG. 2 is an illustration of a portion of a container manufactured according to the prior art.
FIG. 2A is an enlarged view of the container bottom and tail flash showing certain features thereof important to an understanding of the invention.
FIG. 3 is a tail flash formed according to the present invention.
FIG. 4 illustrates the tail flash assembly in its operative position maintained at a specified distance and angular orientation from the container bottom.
FIG. 5 is a perspective view of a portion of a mold suitable for use in the present invention.
FIG. 6 is a bottom plan view of the mold for use in the present invention indicating the means for cooling the projections.
FIG. 7 is a sectional view along the lines 7--7 of FIG. 6.
DETAILED DESCRIPTION
Referring to FIG. 1, the essential steps and apparatus for forming plastic containers are schematically illustrated. A mold half 10 containing four container cavities 12, 14, 16, and 18 is illustrated. The mold half 10 cooperates with a complimentary half (not shown) to form a complete enclosure, the shape of which determines the configuration of the plastic container produced therein. Molten plastic for forming the container is located between the mold halves prior to the halves closing. Air is then injected into the mold forcing the plastic against the walls of the mold to form the container. The plastic is cooled by water flow through the interior walls of the mold.
After the containers have been molded they are released from the mold halves and travel by means of an appropriate conveyor (not shown) onto a shearing conveyor 20. The conveyor 20 may be of the endless belt type or similar and has a plurality of V-shaped container supports 22. Each container support is configured to receive a plastic container 24 thereon with the container positioned on its side relative to the vertical mold cavities 12, 14, 16 and 18. The shearing conveyor moves the containers, one at a time, in the direction indicated by the arrow 26 towards a shearing mechanism 28.
The shearing mechanism consists of a fixed anvil 30 and a reciprocating pinching member 32. The shearing mechanism is provided for the purpose of removing the tail flash from the bottom of the container. As illustrated in FIG. 2, excess plastic provided in each cavity is extruded out the bottom of the mold and forms a tail flash 34. It is this tail flash which must be cut from the bottom of the container to complete manufacture.
With reference to FIG. 2A, the nature of the tail flash can be more clearly discerned. The tail flash 34 is connected to the bottom of a container 36 by means of a pinch off 38. The pinch off is a narrow, necked down portion of material whose thickness is a function of the amount of plastic utilized in producing the container. Thus, where relatively thick walled containers are being formed the pinch off 38 will be of a first thickness t 1 . As the amount of plastic used to form a container is reduced, a thinner walled container will result and, correspondingly, the thickness of the pinch off will be reduced to a value t 2 less than t 1 . FIG. 2 is an example of a prior art container. As the container wall thickness is reduced, the tail flash reaches a point where its weight can no longer be supported by the pinch off 38. Accordingly, it flops from the position indicated in dashed lines to the solid line position where it contacts the container bottom at a plurality of points as indicated, for example, at point 40. This renders the container useless by virtue of preventing of the tail flash from being removed by the severing mechanism.
Referring to FIGS. 1 and 3 to 5, there is illustrated a modification to the mold according to the present invention which results in a tail flash construction which does not suffer from this disadvantage. As best seen in FIG. 5, the bottom portion of the mold halves for each cavity has been modified but, for simplicity of illustration only, a single cavity is shown. The area in which the tail flash is formed is indicated in FIG. 5 at 42. A small spacing, as shown in FIG. 6 at 43, permits the excess plastic to be extruded from the mold cavity into the flash area 42. In the prior art the tail flash emerged from the mold in a molten state attached to the molded container only by the narrow pinch off 38 as illustrated in FIG. 2A.
According to the present invention, the mold is provided with one or more projecting members 44. Thus, the male half of the mold 46 is provided with one or more outwardly projecting members 44 while the female half 48 is provided with complementary recessed portions 50 for receiving the projections 44 therein. The projections 44 are preferably formed with rounded edges to insure easy entry and release of the tail flash from the mold. Their configuration may vary according to the type of container being formed but it is preferred that the projection have a nose-like configuration. The extreme part of the projection contacts the container bottom. Projections may be formed at the time the molds are produced or they may be added to an existing mold using known techniques.
The projections 44 and the complementary receptacles 50 are water cooled in a manner to be described in connection with FIGS. 6 and 7 thus insuring that the portion of the tail flash which is engaged by the projections and receptacles is sufficiently cool and rigid so as to support the tail flash and avoid sticking to the container bottom.
The dimensions of the projection and the number of projections are variable depending upon the size of the container, the amount of tail flash ordinarily resulting from the molding operation and similar variables. As previously indicated, the projections should be nose-like or wedged shaped for easier release and they must extend outwardly far enough so that the tail flash is maintained at a position adequate to permit the shearing mechanism 28 to perform properly.
Referring to FIGS. 2 to 4, the effect of molding one or more projections into the tail flash can be seen. By comparing FIGS. 2 and 3, it will be observed that a pair of standoffs or projections 52 have been provided in the tail flash 54 of bottle 56. These projections are arranged so that they extend towards the side of the bottle which is supported on the shearing conveyor 20 of FIG. 1. When the bottles are removed from the mold the tail flashing 54 remains in its semi-molten condition as with the standard molding operation.
Unlike the FIG. 2 embodiment, however, when the pinch off is insufficiently thick to support the tail flash in the extended position illustrated in FIG. 3, it is prevented from flopping over as illustrated in FIG. 2. Instead, as shown in FIG. 4, the standoffs 52 engage the bottom 53 of the container. This spaces the tail flash from the bottom and maintains it at an acute angle with respect to the container bottom sufficient to permit the shearing mechanism 28 to operate. As indicated previously, since the projections 52 are cooled they do not stick to the container bottom.
Referring now to FIGS. 6 and 7, the construction details of the mold are illustrated. The mold is normally provided with a plurality of water channels 60 through which chilled water flows during the molding operation. This assures rapid cooling of the walls of the container when the molten plastic is blown against the mold. According to the present invention, the projections 44 added to the male half 46 of the mold are similarly cooled by boring additional water channels 62 communicating with an existing channel 64. The cold water flowing through channels 60, 62 and 64 adequately cools the projections 44 to insure that they will not stick to the bottom of the container.
As indicated previously, the point at which it is necessary to start using the present invention is a function of the wall thickness of the container. It has been empirically determined that standoffs formed according to the present invention are required whenever the container wall thickness is at or below 0.020 inches for the usual types of plastics used in blow molding, such as H.D.P.E. When gallon size containers are being molded, if the container weight is over 67 grams, the tail flash will generally be strong enough to hold the tail flash in position. At bottle weights of 65 grams or less for the same size container, the wall thickness is approximately 0.020 inches and the tail flash is no longer adequately supported by the pinch off. Thus, the flop over problem is encountered and requires the use of the present invention to prevent rendering the containers unuseable.
While I have shown and described embodiments of this invention in some detail, it will be understood that this description and illustrations are offered merely by way of example, and that the invention is to be limited in scope only by the appended claims. | 4y
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PRIORITY CLAIM
[0001] This application claims the benefit of previously filed U.S. Provisional Application entitled “SHAPED INTEGRATED PASSIVES,” assigned U.S. Ser. No. 60/932,153, filed May 29, 2007, and which is incorporated herein by reference for all purposes.
FIELD OF THE INVENTION
[0002] The presently disclosed technology relates to shaped integrated passive devices and corresponding methodologies. More particularly, the present technology relates to construction and mounting of shaped passive devices on substrates so as to provide both mechanical and electrical connection.
BACKGROUND OF THE INVENTION
[0003] High density mounting of electronic components on printed circuit boards and other substrates is common in the electronics industry. Miniature ceramic surface mount type capacitors having multiple layers have been used for some time in electronic devices such as cellular telephones, network routers, computers, and the like. The manufacturing techniques of such devices must be precise to provide for the greatly reduced size of these devices, while still affording desirable electrical operating characteristics.
[0004] More recently it has become desirable to provide further types of components and various sub-circuits in on-board mountable form. Several United States patents are directed to various aspects of electronic component manufacture and mounting techniques. For example, U.S. Pat. No. 6,271,598 (Vindasius et al., entitled “Conductive Epoxy Flip-Clip on Chip”) is directed to a chip-on-chip mounting arrangement wherein each of a plurality of stacked chips is provided with a beveled, insulated perimeter where a number of chips may be interconnected via conductive epoxy. U.S. Pat. No. 6,594,135 (Ervasti, entitled “Filter”) is directed to a multi-stage filter produced on a connection base that includes a ground potential area on the back side thereof.
[0005] Additional publication material includes an article entitled “Silicon Micro-Machining as an Enabling Technology for Advanced Device Packaging” as published in Semiconductor Manufacturing Magazine, November 2004. Also, additional patent citations include U.S. Pat. No. 7,112,879 (Fielstad et al., entitled “Microelectronic Assemblies Having Complaint Layers”); U.S. Pat. No. 6,954,130 (Marcoux, et al., entitled “Integrated Passive Components and Package With Posts”); U.S. Pat. No. 6,202,299 (DiStefano et al., entitled “Semiconductor Chip Connection Components With Adhesives and Method of Making Same”); U.S. Pat. No. 5,877,551 (Tostado et al., entitled “Semiconductor Package Having a Ground or Power Ring and a Metal Substrate”); U.S. Pat. No. 4,670,770 (Tai, entitled “Integrated Circuit Chip and Substrate Assembly”); U.S. Pat. No. 4,431,977 (Sokola et al., entitled “Ceramic Bandpass Filter”).
[0006] For some time, the design of various electronic components has been driven by a general industry trend toward miniaturization and ease of incorporation of components into new or existing applications. In such regard, a need exists for smaller electronic components having exceptional operating characteristics. For example, some applications require the use of passive devices exhibiting various characteristics including capacitive, inductive, and/or resistive characteristics or combination assemblies thereof, but are severely limited in the amount of space (known as “real estate”) such devices may occupy on a circuit board. It is important that such devices or combinations be configured for maximum ease of physical and electrical attachment to such circuit boards while occupying the least amount of“real estate” possible.
[0007] While various implementations of surface mount passive devices and assemblies have been developed, no design has emerged that generally encompasses all of the desired characteristics as hereafter presented in accordance with the subject technology.
SUMMARY OF THE INVENTION
[0008] The present subject matter recognizes and addresses several of the foregoing issues, and others concerning certain aspects of integrated passive devices. Thus, broadly speaking, an object of certain embodiments of the presently disclosed technology is to provide an improved design for certain components and component assemblies associated with the implementation of surface mountable devices.
[0009] Aspects of certain exemplary embodiments of the present subject matter relate to the provision of a specially shaped integrated passive device capable of providing simplified mounting on and simultaneous connection to selected electrical pathways on a printed circuit board or other mounting substrate. In other present aspects, present subject matter may more generally be directed to shaped, plated side filter devices wherein the plated sides provide both mounting and grounding/power coupling functions.
[0010] Aspects of other exemplary embodiments of the present subject matter provide improved electrical coupling of certain signal pathways from a surface mount device to circuits or traces on a printed circuit board on which the device may be mounted.
[0011] Still further aspects of yet still other embodiments of the present subject matter provide enhancements to manufacturing methodologies associated with the use of surface mount type devices.
[0012] Still further, it is to be understood that the present technology equally applies to the resulting devices and structures disclosed and/or discussed herewith, as well as the corresponding involved methodologies.
[0013] In other present exemplary aspects, the present subject matter may more particularly relate to thin film filters constructed on silicon wafers. With such exemplary devices constructed as herein, following such filter construction, the silicon wafer may be preferably diced from the top surface with an angular dicing saw to produce a v-groove in the top surface. The v-groove may then preferably be plated with a conductive material and the individual pieces separated by grinding the back surface of the wafer down to where the grooves are intercepted. The plated grooves may then advantageously serve as ground or power connection points for the filter circuit as well as provide mounting functionality as the individual pieces may be secured to a mounting surface, securing (by soldering or using conductive epoxy) the pieces to a support substrate by using the metallized slopes of the plated grooves.
[0014] Further still, it should be strictly understood that while the present description relates primarily to the production of surface mountable shaped passive devices embodied as thin-film filters and their particular configurations allowing improved surface mounting methodologies, the description of such passive components does not constitute a limitation of the present technology. For example, the present technology may be applied to individual resistor, capacitor, or inductor elements or circuits involving plural such elements configured in various combinations. As such, the present subject matter anticipates combinations including, but not limited to, resistive and/or capacitive “ladder” configurations, resistive and/or capacitive matrix configurations and various other combinations of passive elements.
[0015] Yet further still it should be appreciated that certain aspects of the present subject matter may be applied to individual active components or combinations thereof with passive components. For example, active combinations including, but not limited to, amplifiers, oscillators, and other functional block assemblies may benefit from the present technology.
[0016] One exemplary present embodiment relates to an integrated electronic component, comprising a printed circuit board with at least one conductive trace thereon; an electronic device characterized by opposing top and bottom surfaces, first and second side surfaces and first and second end surfaces, such electronic device comprising a circuit and at least one respective first and second connection points for such circuit formed on such top surface of such electronic device; a first portion of plating material extending from such bottom surface of the electronic device, along such first side surface of the electronic device, and onto such top surface of such electronic device, wherein such first portion of plating material forms an electrical connection to the at least one first connection point on such top surface of such electronic device; a second portion of plating material extending from such bottom surface of such electronic device, along such second side surface of the electronic device, and onto such top surface of such electronic device, wherein such second portion of plating material forms an electrical connection to the at least one second connection point on such top surface of such electronic device; and at least one portion of conductive epoxy positioned between such printed circuit board and such electronic device for mounting such electronic device to such printed circuit board and for electrically connecting such first and second portions of plating material to the at least one conductive trace located on such printed circuit board.
[0017] In various alternatives of the foregoing exemplary embodiment, such circuit may comprise an integrated thin-film filter including at least one inductor and at least one capacitor, or may comprise at least one of a capacitor, inductor, resistor, filter, amplifier, and oscillator.
[0018] In other present exemplary alternative arrangements of the foregoing, each of such first and second side surfaces of such electronic device may slope outwardly from such top surface of such electronic device to such bottom surface of such electronic device.
[0019] In yet other present alternatives, such first portion of plating material may substantially cover such first side surface of such electronic device; and such second portion of plating material may substantially cover such second side surface of such electronic device.
[0020] In other present exemplary alternatives of the foregoing, selected ones of the at least one conductive trace on such printed circuit board may provide a ground connection to selected ones of such at least one first and second connection points for the circuit, and/or selected ones of such at least one conductive trace on such printed circuit board provide a power connection to selected ones of such at least one first and second connection points for such circuit.
[0021] In the foregoing exemplary integrated electronic component, in some alternatives thereof such circuit may further comprise respective input and output terminals; and such printed circuit board may include respective terminal pads to which such respective input and output terminals of such circuit are electrically connected. In such alternatives, further optional features may be practiced, for example, including a first wire bond connection for electrically coupling such input terminal of such circuit to one of such terminal pads on such printed circuit board; and a second wire bond connection for electrically coupling such output terminal of such circuit to one of such terminal pads on such printed circuit board.
[0022] In yet another present exemplary embodiment of the present subject matter, a surface mount electronic component may comprise a substrate characterized by opposing top and bottom surfaces, first and second side surfaces, and first and second end surfaces; a circuit, formed on such top surface of such substrate, and including at least one pair of first and second opposing connection points; a first portion of plating material, formed along such top surface of such substrate onto such at least one first connection point, and also extending from such top surface of such substrate along such first side surface of such substrate to such bottom surface of such substrate; and a second portion of plating material, formed along such top surface of such substrate onto such at least one second connection point, and also extending from such top surface of such substrate along such second side surface of such substrate to such bottom surface of such substrate. In the foregoing exemplary embodiment, preferably such first and second portions of plating material are respectively configured to provide both mechanical and electrical connections for such electronic component when such electronic component is mounted in a circuit environment.
[0023] It should be understood that the present subject matter is equally applicable to corresponding methodologies. For example, one present exemplary methodology relates to a method of making electronic components, comprising providing a substrate characterized by respective top and bottom surfaces; forming a plurality of respective circuits on the top surface of the substrate, wherein each circuit comprises at least one connection point; forming at least one groove in the upper surface of the substrate between selected ones of the plurality of respective circuits, wherein the at least one groove is formed only partially through the substrate in a direction towards the bottom surface of the substrate; metallizing respective areas along the top surface of the substrate, wherein each metallized area extends across a given groove, onto one or more portions of the top surface of the substrate adjacent to the given groove and further into contact with at least one connection point associated with a respective circuit; and separating the plurality of respective circuits.
[0024] In alternatives of the foregoing exemplary method, such step of separating the plurality of respective circuits may comprise forming one or more cuts completely through the substrate.
[0025] In other present alternatives, such method may further comprise a step of grinding the bottom surface of the substrate. In such alternative, such step of separating the plurality of respective circuits may comprise such grinding step; and such grinding step may continue until the bottom portions of the at least one groove are reached.
[0026] In other present alternatives of the foregoing, such grinding step may comprise situating the top surface of the substrate face down onto an adhesive coated material; and grinding the exposed bottom surface of the substrate.
[0027] In yet other present alternative methodologies, such step of forming at least one groove may comprise cutting a groove with a dicing saw. Still further, such step of forming at least one groove may alternatively comprise cutting one of a V-shaped groove, a rectangular groove, a multi-stepped groove, and a semi-circular groove.
[0028] In other present exemplary alternative methodologies, such step of metallizing respective areas may comprise plating a conductive metal; or one or more of such respective circuits may comprise a thin-film filter including at least one inductor and at least one capacitor; or selected circuits formed on the substrate may comprise one or more of a capacitor, inductor, resistor, filter, amplifier, and oscillator. In still further present alternatives, the plurality of respective circuits may be formed on the top surface of the substrate in an array of rows of circuits; and a groove may be formed on the top surface of the substrate between each row of circuits.
[0029] Additional objects and advantages of the present subject matter are set forth in, or will be apparent to those of ordinary skill in the art from, the detailed description herein. Also, it should be further appreciated by those of ordinary skill in the art that modifications and variations to the specifically illustrated, referenced, and discussed features and/or steps hereof may be practiced in various embodiments and uses of the disclosed technology without departing from the spirit and scope thereof, by virtue of present reference thereto. Such variations may include, but are not limited to, substitution of equivalent means, steps, features, or materials for those shown, referenced, or discussed, and the functional, operational, or positional reversal of various parts, features, steps, or the like.
[0030] Still further, it is to be understood that different embodiments, as well as different presently preferred embodiments, of this technology may include various combinations or configurations of presently disclosed steps, features or elements, or their equivalents (including combinations of features, configurations, or steps thereof not expressly shown in the figures or stated in the detailed description).
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] A full and enabling description of the present subject matter, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which:
[0032] FIG. 1 illustrates a generally top, side, and end perspective view of an exemplary passive thin-film filter device constructed in accordance with the present technology;
[0033] FIG. 2 is an electrical circuit schematic representation of the exemplary filter structure illustrated in FIG. 1 ;
[0034] FIG. 3 is a generally top, side, and end perspective view of a shaped passive thin-film filter device constructed and mounted on a substrate, in accordance with the present technology;
[0035] FIGS. 4 , 5 a, 6 , and 7 are various generally top, side, and end perspective views respectively representing various stages of construction for the shaped passive thin-film filter device constructed in accordance with the present technology; and
[0036] FIG. 5 b illustrates a partial view of an alternative embodiment of the partially constructed shaped passive thin-film filter device of FIG. 5 a showing an alternative rectangular groove arrangement.
[0037] Repeat use of reference characters throughout the present specification and appended drawings is intended to represent same or analogous features, elements, or steps of the present subject matter.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0038] As discussed in the Summary of the Invention section, the present subject matter is particularly concerned with certain aspects of integrated passive devices and related technology and manufacturing methodology. More particularly, the present subject matter is concerned with improved shaped integrated passive devices designed to provide improvements in mounting and electrical connection technologies for both passive and active devices and combinations thereof, and related construction methodologies.
[0039] Selected combinations of aspects of the disclosed technology correspond to a plurality of different embodiments of the present subject matter. It should be noted that each of the exemplary embodiments presented and discussed herein should not insinuate limitations of the present subject matter. Features or steps illustrated or described as part of one embodiment may be used in combination with aspects of another embodiment to yield yet further embodiments. In additional, certain features may be interchanged with similar devices or features not expressly mentioned which perform the same or similar function.
[0040] Reference will now be made in detail to exemplary presently preferred embodiments involving an exemplary shaped integrated passive thin-film filter device generally 100 . Referring now to the drawings, FIG. 1 illustrates a generally right-side, top, end perspective view of an exemplary passive thin-film filter device generally 100 constructed in accordance with the present technology.
[0041] Exemplary passive thin-film filter device 100 may correspond to a multi-pole filter circuit 200 , as schematically illustrated in FIG. 2 . Multi-pole filter circuit 200 may be constructed on silicon wafer generally 110 or other suitable substrate material including, but not limited to, high-resistivity silicon, glass, quartz, or any other insulating material using techniques for constructing such devices on silicon that are well known to those of ordinary skill in the art. As such construction techniques are well known and form no particular part of the present subject matter; such will not be further described herein.
[0042] As may be observed from a comparison of present FIGS. 1 and 2 , exemplary passive thin-film filter device 100 may include a number of components, only selected individual exemplary ones of which are herein specifically identified, including for example inductors 112 and 114 and capacitors 116 and 118 . It should be appreciated that the exact form of filter provided in association with exemplary shaped passive thin-film filter device 100 is not a limitation of the present technology but rather an example of the type of device and an exact form thereof that may be provided through use of the present technology.
[0043] With further reference to FIGS. 1 and 2 , it will be noticed that an exemplary input terminal 120 and exemplary output terminal 122 are provided for multi-pole filter circuit 200 . Further, a number of ground connection or reference points 130 , 132 , 134 , and 136 are provided. The presence of ground connection or reference points 130 , 132 , 134 , and 136 in association with the components forming multi-pole filter circuit 200 , are significant to the present subject matter in that the specific physical configuration of shaped passive thin-film filter device 100 constructed in accordance with the present technology provides advantageous and previously unknown combined mounting and electrical connection capabilities.
[0044] More particularly, as may be seen from FIG. 1 , respective pairs of ground connection or reference points 130 , 132 , and 134 , 136 may be electrically coupled directly together by way of plating material formed over respective portions 150 and 152 , formed respectively of upper surface 146 and respective sloped sides 142 , 144 of shaped passive thin-film filter device 100 . Such electrical coupling of ground connection or reference points 130 , 132 , 134 , and 136 provides a significant advance over previous connection methodologies involving similar types of devices.
[0045] Prior to the development of the present technology, multiple wire bond connections would have been required to connect the multiple points 130 , 132 , 134 , and 136 . Such multiple connection wire bonding technology not only requires significant costs in both labor and time for production, but results in multiple points where manufacturing problems may occur as well as multiple opportunities for impacting electrical characteristics of the mounted device by way of possible variations in bonding contact resistance as well as variations in lead length of the wire bonds themselves resulting in variations in inductance to ground or other connections.
[0046] Devices constructed in accordance the present technology avoid all such potential problems by providing much improved capabilities and characteristics. More specifically, it will be noticed that side portions 142 , 144 of an exemplary embodiment of shaped passive thin-film filter device 100 are sloped outwardly from a top surface 146 toward a bottom surface 148 . It should be appreciated, however, that alternative shapes for side portions 142 , 144 are possible as will be further addressed hereinbelow with reference to FIG. 5 b. An exemplary methodology for achieving such sloped configuration will be discussed more fully hereinbelow with respect to FIGS. 4-7 .
[0047] The provision of sloped side portions 142 , 144 represents an advantageous aspect of certain embodiments of the present subject matter. More particularly, sloped side portions 142 , 144 may be conductively plated so as to provide not only electrical connection points for selected components of filter 200 but so as to also provide a simplified mounting capability for the finished shaped passive thin-film filter device 100 . Conductive plating material may correspond to gold plating or other appropriate conductive materials, the selection of which materials is known to those of ordinary skill in the art without additional discussion.
[0048] As may be further seen in present FIG. 3 , the exemplary finished shaped passive thin-film filter device 100 of the present subject matter may be mounted to an exemplary printed circuit board 300 or other suitable substrate by way of representative conductive epoxy 310 . Conductive epoxy 310 may extend beneath passive thin-film filter device 100 as illustrated in FIG. 3 at reference area 312 so that both mechanical and electrical connections may be implemented with selected portions of printed circuit board 300 . As illustrated in FIG. 3 , passive thin-film filter device 100 , and particularly also the conductive plating formed on sloped sides 142 , 144 , may be respectively mechanically and electrically coupled to, for example, respective conductive traces 330 , 332 on printed circuit board 300 .
[0049] In an exemplary configuration where conductive epoxy 310 extends beneath device 100 , conductive traces 330 , 332 may be electrically coupled together by portion 312 of conductive epoxy 310 . Alternatively, conductive epoxy 310 may be placed only at the edges of plated sloped sides 142 , 144 so that an electrical connection may not be completed between conductive traces 330 , 332 . If, as in the presently described exemplary embodiment, conductive traces 330 , 332 are designed to provide a ground or reference connection for the thin-film filter device 100 as illustrated, the electrical connection of traces 330 , 332 may be appropriate. In fact, traces 330 , 332 may actually be connected on the substrate or might correspond to a singe trace.
[0050] In alternative embodiments, also in accordance with the present subject matter, where device 100 may correspond to alternative type devices including matrix or ladder type configurations of resistor and/or capacitor combinations (or alternatively yet, active device configurations as previously mentioned hereinabove), traces 330 , 332 may correspond to power rails providing operating power to device 100 and, therefore should not be connected together. In such instances, as will be understood by those of ordinary skill in the art, conductive epoxy 310 may be applied only in the areas adjacent the junctures of sloped sides 142 , 144 and bottom surface 148 .
[0051] With further reference to FIG. 3 , it will be seen that input terminal 120 of thin-film filter device 100 may be connected to terminal pad 320 on printed circuit board 300 such as by way of wire bond connection 220 . Terminal pad 320 may, in turn, be coupled to other components or circuitry (for the sake of clarity, not presently illustrated) on printed circuit board 300 . Likewise, output terminal 122 of thin-film filter device 100 may be connected to output terminal pad 322 such as by way of wire bond connection 222 . In a manner similar to that associated with input terminal pad 320 , output terminal pad 322 may also be connected to additional components or circuitry (not presently illustrated) on printed circuit board 300 .
[0052] As may be seen with still further reference to FIG. 3 , mechanical and electrical connection of thin-film filter device 100 may be accomplished simply and effectively in accordance with the present technology, for example, through the use of conductive epoxy 310 and two wire bonds. Previously, mounting of a similar filter or other devices would have required many additional wire bonds to provide an alternative to the connections supplied by the conductive epoxy and plated slope technology in accordance with the present subject matter.
[0053] As mentioned previously, an important aspect of the present subject matter relates to the improved electrical characteristics obtained through implementation of the present subject matter. More specifically, by elimination of the previously required plurality of wire bonds, variations and reduction in or elimination of connecting line inductance and resistance are provided by application of the present subject matter. In particular the elimination of undesirable inductance produced by previously employed wire bonds translates to significant improvement in the high-frequency behavior of the filter.
[0054] With reference now to FIGS. 4 , 5 a, 6 , and 7 , exemplary methodology for constructing exemplary thin-film filter device 100 in accordance with the present technology will be described. As may be seen in FIG. 4 , several of thin-film filters representatively illustrated at 410 , 420 may be constructed on silicon wafer 400 using techniques well known to those of ordinary skill in the art. It should be appreciated that there may, in fact, be many more than the six devices illustrated constructed simultaneously on wafer 400 .
[0055] Following formation of the multiple thin-film filters 410 , 420 , in accordance with an exemplary embodiment of present subject matter, V-shaped grooves 510 , 512 , 514 , and 516 (see FIG. 5 a ) may be cut or formed along the longer sides of thin-film filters 410 , 420 , for example, such as by using an angular dicing saw. As illustrated in FIG. 5 a, V-shaped grooves 510 , 512 , 514 , and 516 are formed only partially through silicon substrate 400 . A metallization process as represented in FIG. 6 may then be employed to metallize the V-shaped grooves as well as portions 150 , 152 of the upper surface 146 of silicon substrate 400 . Metallization portions 150 , 152 extend sufficiently over upper surface 146 of silicon substrate 400 so as to contact and electrically connect with ground connection or reference points 130 , 132 , 134 , and 136 , as previously discussed with reference to present FIGS. 1 and 2 .
[0056] With brief reference to FIG. 5 b, it should be appreciated that other groove configurations may be employed without departing from the spirit and scope of the present subject matter. In that light, a portion of a second exemplary embodiment of the present subject matter is illustrated in FIG. 5 b wherein rectangular grooves 510 ′, 512 ′ have been provided. It should be farther appreciated that the exact shape of the groove is not a limitation of the present subject matter as appropriate grooves may be provided in many forms. Non-limiting additional examples may include multi-stepped grooves, semi-circular grooves or other configuration. The grooves simply need to be configured so as to penetrate only partially through the substrate and be configured so as to permit plating or metallization as previously described.
[0057] Final steps in the production of individual shaped passive thin-film filter devices 100 may require backgrinding of silicon substrate 400 , and the introduction of one or more straight or other suitable cuts through substrate 400 as, for example, illustrated at cut line 6 - 6 of FIG. 6 . Backgrinding, that is, the removal of a portion of the rear side of silicon substrate 400 by grinding, may be achieved such as by situating substrate 400 face down onto an adhesive coated material and thereafter grinding the exposed rear surface. Such grinding may continue until the bottom portions of V-shaped grooves 510 , 512 , 514 , and 516 are reached, generally as illustrated at about line 600 ( FIG. 6 ). Final cuts along line 6 - 6 of FIG. 6 may then be used to separate the individual shaped passive thin-film filter devices 100 , completion of which is as illustrated in FIG. 7 .
[0058] While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing may readily adapt the present technology for alterations or additions to, variations of, and/or equivalents to such embodiments. Accordingly, the scope of the present disclosure is by way of example rather than by way of limitation, and the subject disclosure does not preclude inclusion of such modifications, variations, and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for the preparation of metal matrix fiber composites. In particular, the present invention relates to a method which produces metal powders uniformly coated on fibers as a result of aerosolization of the powders and then consolidation of the powder on the fibers to form the matrix.
2. Description of Related Art
Fabricating metal matrix composites with fiber tows surrounded by the metal matrix has always presented difficulties to materials producers. Unlike the viscous polymers, liquid metals have a viscosity similar to water. (Mortensen, A., et al, Journal of Metals, 30 (1986)). If the fiber can be wetted by the matrix material, a liquid-infiltration technique could be a first choice because of simplicity and continuity. If the fiber is not wetted by the metal, a suitable fiber coating or matrix alloying addition had to be found to facilitate wetting. In either case, interfacial reaction between the metal and the fiber is hard to control due to overexposure to molten metal. Uneven fiber distribution in the metal matrix is also an unsolved problem. The problems encountered with liquid phase processes are 1) porosity from solidification shrinkage (opening voids between the fibers), 2) low fiber volume fraction, 3) interface reaction degradation, and 4) uneven distribution of fibers. Most of the problems arise from the difficulty in wetting the fiber with the liquid metal.
The problems are reduced with squeeze casting into a mold with a preform of fibers (Bader, M. G., et al., Composites Science and Technology 23 287-301 (1985); and Kohara, S., et al., Composites '86: Recent Advances in Japan and the United States, eds. K. Kawata, S. Umekawa and A. Kobayashi, (Proceedings of Japan-U.S. CCM-III, Tokyo, 491-496 (1986)). However the problems increase as the fiber diameter decreases. Alloy additions can reduce the wetting contact angle with the fibers; however, they also cause more interface reactions, which usually degrades the bond or the integrity of the fiber (Mortensen, A., et al., Journal of Metals, p. 30 (March 1986)). Other methods, such as electroplating, spraying, chemical vapor deposition and physical vapor deposition, could produce high quality composites, but the methods are time consuming and expensive. Plasma spraying coats fibers with a liquid metal, which can later be arranged in a desirable way, can be accomplished but only with large (140 μm) diameter plasma sprayed fibers. Furthermore, these known techniques are generally not suitable for commercial large-scale or continuous processing.
Powdered metal processing with fibers eliminates or reduces the interface wetting/reaction problem with liquid processing. The metal is sintered and forms around the fiber in the solid state. The kinetics for interface reactions are much slower in powder methods. The two major problems of this strategy are 1) fiber damage may occur under the pressure needed for consolidation (Erich, D. L., Int. J. Powder Metallurgy, 23 45-54 (1987), and 2) high fiber volume fractions are not possible, if large or agglomerated powder particles are present, since they cause the fibers to bunch up (Shimizu, J., et al., Metal & Ceramic Matrix Composites: Processing Modeling & Mechanical Behavior, eds. R. B. Bhagat, A. H. Clauer, P. Kumar and A. M. Ritter, (TMS/AIME Warrendale Pa.) 31-38 (1990)).
Fibers can be manually arranged between layers of foil and hot pressed. There are a limited number of foil compositions available and the volume fraction of fibers is often small, and the fiber diameters are large (Mortensen, A., et al., Journal of Metals, p. 30 (March 1986)). These processes often provide dramatically better properties than predicted by continuum models of discontinuous fibers, since dislocations generated near the interface deflect cracks and change matrix properties near the interface, due to strains from thermal expansion mismatch (Erich, D. L., Int. J. Powder Metallurgy, 23 45-54 (1987); and Arsenault, R. J., Mat. Sci. and Eng. 64 171-181 (1984)).
A continuous fiber-reinforced polymer matrix composite method was originally developed by Drzal et al (U.S. Pat. Nos. 5,042,122, 5,042,111, 5,123,373, 5,128,199, and 5,310,582). In the Drzal et al method, an unsized carbon fiber tow goes through different chambers to make a prepreg tape of a polymer matrix composite. A fiber tow is driven by a motor from a fiber spool to pass above a speaker. The sound waves coming off the speaker spread the fibers apart. The spread fibers are held in position by ten stainless steel shafts spaced one inch apart and placed on the top of the speaker. After spreading, the fibers pass through an optional pre-treatment chamber to modify the fiber surface or to apply a thin coating of binder material to improve adhesion with the matrix. Then, the fibers enter an impregnation chamber, called aerosolizer, where small polymer particles (about 10 microns in diameter) are suspended by the effect of a vibrating rubber membrane placed on top of a speaker, which works as a bed of polymer powders. The powders are attached to the fibers by an electrostatic force generated from the static charges held by the fine polymer particles. After coating with polymer particles, the fibers pass through the oven chamber for about 15 seconds. The particles are heated by convection and radiation until sintering occurs between adjacent particles to form a thin film. The impregnated fibers are then cooled and wound on a take up drum. After a run, the resulting prepreg tape is cut into pieces to a desired length and are laid-up in a rectangular stainless steel mold for hot pressing according to a pressure-temperature-time profile. A sheet of continuous fiber-reinforced polymer matrix composite material is thus formed and is evaluated. The problem is to provide a continuous fiber metal matrix composite (CFMMC).
Finely divided metal powders are explosive in an atmosphere containing any oxygen and thus the aerosolization of powders in air has not been considered to be useful as a method for coating fibers. Serious problems are created by the use of aerosolized powders which have not been solved by the prior art.
OBJECTS
It is therefore an object of the present invention to provide a method for producing a continuous fiber reinforced metal matrix composite. It is further an object of the present invention to provide a method wherein the problem of non-wetting of the fibers is eliminated and wherein the destructive interaction between the metal matrix and the fibers is minimized. Further still, it is an object of the present invention to provide a method using metal powders which is safe and economical. These and other objects will become increasingly apparent by reference to the following description and the drawings.
IN THE DRAWINGS
FIG. 1 is a schematic view of a system 10 used to process continuous fibers to produce a continuous fiber metal matrix composite 100 (CFMMC). The system 10 includes a fiber spool 11, speaker spreader 12, optional pretreatment chamber 13, polymer coating chamber or aerosolizer 14, heater 15 and take up drum 16 of the Drzal et al patents. The new metal powder aerosolization apparatus 20, furnace 40, and consolidation rolls 50 are provided for forming the CFMMC 100.
FIG. 2 is a schematic cross-sectional view of the metal powder coating apparatus 20, particularly showing an aerosolization inside tube 24 adapted to prevent explosion of the aerosolized metal powder. FIG. 2A is a partial enlarged section of FIG. 2 showing the mounting of the membrane 25.
FIGS. 3A shows a confinement tube 21 for the aerosolization apparatus 20. FIG. 3B is a side view of the shape of the bottom lid 27. FIG. 3C is a plan view of the top lid 28 showing entry ports 28A and which otherwise is the same as the bottom lid 27.
FIG. 4 is a front view of the inside tube 24, partially showing an o-ring groove 24A, gas inlet 29 and outlet 30 and tungsten pins 24B for electrical connection.
FIG. 5 is a front view of the inside tube 24 showing the mounting of a heater 31 inside the tube 24 and section of prepreg tape 32 mounted inside the heater 31.
FIG. 6 is a schematic view of a vacuum system 60 for the inner tube 24 and the connections 72 to 75 through the cover 28 of outer tube 21.
FIG. 7 is a front view of simple beam subjected to three-point bending for test purposes.
FIGS. 8A to 19B relate to Example 1.
FIGS. 8A is a scanning electron microscope (SEM) micrograph of an Example 1 type A prepreg (250X) and FIG. 8B is a SEM micrograph of a type B prepreg (300x) prior to incorporating the metal matrix.
FIG. 9A is another SEM micrograph of the type A prepreg (350X) and FIG. 9B is another SEM micrograph of the type B prepreg (800X).
FIG. 10A is the SEM micrograph of the type A prepreg (50X) coated with aluminum powders. FIG. 10B is the SEM micrograph of the type B prepreg coated with aluminum particles (50X).
FIG. 11A is another SEM micrograph of the type A prepreg coated with the aluminum particles (150X) and FIG. 11B is another SEM micrograph of the type B prepreg coated with the aluminum powder (250X).
FIG. 12 is a graph showing a load-extension curve for the CFMMC from two samples of the type A prepreg consolidated with the aluminum powder to form the CFMMC.
FIG. 13 is a graph showing a load-extension curve for the CFMMC from a sample of the type B prepreg consolidated with the aluminum powder.
FIG. 14A is a typical SEM micrograph of a cross-section of the CFMMC from the type A prepreg (200X). FIG. 14B is the SEM micrograph from the type B prepreg (200X).
FIG. 15A is another SEM micrograph of the CFMMC from the type A precursor (500X). FIG. 15B is the SEM micrograph from the CFMMC of the type B prepreg.
FIG. 16A is an optical micrograph from a longitudinal section of the CFMMC from the type A prepreg (200X). FIG. 16B is the optical micrograph of a longitudinal section of the CFMMC from the type B prepreg (200X).
FIG. 17A is another optical micrograph of a longitudinal section of the CFMMC from the type A prepreg (500X). FIG. 17B is the optical micrograph of the longitudinal section of the CFMMC from the type B prepreg (500X).
FIG. 18A is SEM fractograph (pulled apart) of the CFMMC from the type A prepreg (170X). FIG. 18B is the fractograph from the CFMMC from the type B prepreg (100X).
FIG. 19A is another SEM fractograph of the CFMMC from the Type A prepreg (1.20kx). FIG. 19B is the SEM fractograph of the CFMMC from the Type B prepreg (1.20 kx).
FIG. 20 is a SEM micrograph of a CFMMC of Example 2 showing uniform dispersion of the aluminum matrix around the fibers.
FIG. 21 is a schematic front view of a continuous processing system 80 for producing CFMMC products 102A to 102C having various cross-sections.
FIGS. 21A to 21C show various constructions for consolidation rolls 50 for producing the products 102A to 102C.
FIG. 22 is a schematic front view of another system 90 for incorporating a metal matrix 103 onto a core 92 for consolidation.
FIGS. 23 to 26 are optical microscopic micrographs of transverse and longitudinal sections of a composite product prepared without the use of a binder as in Example 3.
FIGS. 27 and 28 show scanning electron microscope (SEM) micrographs of sections resulting from fracture of a specimen.
DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention relates to a method for forming a composite product which comprises:
(a) providing fibers coated with particles of an oxidizable metal containing powder; and
(b) pressing the powder coated fibers in a heated press so that the particles of the metal containing powder consolidate with the fibers to form the composite product.
Further the present invention relates to a method for forming a composite product which comprises:
(a) introducing a tow of fibers coated with beads of a polymer into a closed chamber containing particles of an oxidizable metal containing powder to be coated onto the fibers in a controlled atmosphere which prevents uncontrolled oxidation of the metal containing powder;
(b) aerosolizing the powder in the chamber in the controlled atmosphere so as to coat the particles on the polymer and fiber;
(c) removing the particle coated tow of fibers from the chamber; and
(d) consolidating the particle coated tow of fibers in a heated press so that the metal powder sinters and flows together and forms a matrix around the fibers to provide the composite product.
Finally the present invention relates to a method for forming a composite product which comprises:
(a) introducing a tow of fibers into a closed chamber containing particles of an oxidizable metal containing powder to be coated onto the fibers in a controlled atmosphere which prevents uncontrolled oxidation of the metal containing powder;
(b) aerosolizing the powder in the chamber in the non-reactive atmosphere so as to coat the particles on the fibers;
(c) removing the particle coated tow of fibers from the chamber; and
(d) consolidating the particle coated tow of fibers in a heated press so that the metal containing powder sinters together and forms a matrix around the fibers to provide the composite product.
The fibers can be inorganic or organic so long as they can be consolidated with heating to form the metal matrix. Such fibers are composed of for instance carbon, glass, ceramic, such as silicon carbide, aluminum oxide and boron, and metals.
The metal powders are preferably Al, Ti, Cu, Be, Mg and alloys thereof. Preferred is aluminum and alloys thereof because of weight considerations. Metal containing powders with polymer powders or ceramic powders can also be used so long as they aerosolize and consolidate.
The controlled atmosphere for the aerosolization is usually provided by a non-reactive gas such as argon, helium, nitrogen and the like. Argon is preferred since it is readily available.
If a polymer coating is used as a binder for the metal particles it is removed. Usually a vacuum furnace is used. The vacuum and the elevated temperature are first sufficient to remove the polymer coating and then to melt the metal to form the matrix. For aluminum powder and carbon fibers the temperature is between 500°-600° C. All of these variations will be obvious to one skilled in the art.
Aerosolized fine metal powders in a controlled atmosphere was used. One system 10 is shown in FIG. 1. In one method, the fibers are coated with sticky polymer in aerosolization apparatus 14, enter the oven chamber 15 for adhering the polymer to the fibers and then enter a second coating apparatus 20 where they are then coated with fine metal powders (matrix material). This coated prepreg is the precursor of the CFMMC. The precursor is then cut into pieces and laid up for hot pressing into the CFMMC.
The method of the present invention has many advantages compared with the existing CFMMC fabrication techniques:
1) it minimizes undesired interface reactions because the polymer coated precursor is produced at much lower temperatures;
2) fibers are evenly distributed throughout the composite by the spreading operation. This reduces fiber damage usually caused by fiber-to-fiber contact;
3) uniform distribution of the matrix around each fiber is achieved from the use of the aerosolizer and fine metal powder with smaller size (5.5 microns in diameter) than the diameter of the fibers (8.0 microns) as in Examples 1 and 2;
4) high fiber volume fraction can be obtained due to the effective use of the spreader and fine metal powders;
5) high quality composites can be made because of homogeneous fibers and matrix distribution, high fiber volume fraction, reduced interface reactions; and
6) it is far less expensive than most of the existing CFMMC fabrication techniques because of its simplicity, continuity and provision for automation.
The following are illustrative examples. Example 1 uses a polymer coating on the fibers. Example 2 does not use the polymer coating.
EXAMPLE 1
As shown in FIGS. 2 and 2A, the outer tube 21 of apparatus 20 was made of plexi-glas material because the fluidization of the powders requires visual adjustments to determine the appropriate frequency of the speaker 22. The speaker 22 was mounted in a wood box 23. A glass tube 24, was provided with membranes 25 at either end. An aluminum flange 26 at a lower end of tube 24 was connected to the speaker 22 and supports lower membrane 25 on the glass tube 24.
As shown in FIGS. 3A, 3B and 3C, the outer tube 21 had two lids opposed 27 and 28 made of aluminum for the top and the bottom (FIG. 3). The lids 27 and 28 each had an o-ring 27A and 28A (FIG. 2) around the inside to assure sealing. The calculations show that the outer tube 2-1 and the lids 27 and 28 were strong enough to withstand an external pressure of one atmosphere. During experiments, the two lids 27 and 28 were held onto the chamber 21 by three elastic stretch cords between them (not shown) for safety. The stretch cords will give in the event of an explosion.
As shown in detail in FIG. 4, the inside tube 24 was a hollow where the actual coating occurs. Half an inch from the top of tube 24, a small indentation or groove 24A was provided on the outside for an o-ring 34 to hold the top membrane 25. At three inches from the top, six tungsten pins 24B were mounted around the circumference to serve as electrical feedthroughs. Two gas ports 29 and 30 were provided on the inside tube 24 open to the outer tube 21. The inside tube 24 was set on the aluminum flange 26 which was fixed by the wood box 23 above the speaker 22. The lower membrane 25 was held between the glass tube 24 and the aluminum flange 26 by a ring seal 33 in groove 26A of flange 26.
As shown in FIG. 5, a flexible heater 31 was wound around a metal tube 31A, is hung on two of the tungsten pins 24B in the inside tube 24. Prepreg tapes 32 were fixed by spring clips (not shown) inside the metal tube 31A where the temperature was almost uniform.
Tables 1 and 2 show the distribution of the temperature inside the metal tube 31A. Pins 24B were needed to pass a signal from the outside to the inside of the tube 21 without interfering with the vacuum level inside the tube 21. The feedthroughs 72 to 75 (FIG. 6) were made of bulkhead unions that fit through the holes 28A of the top lid 28.
TABLE 1______________________________________The distribution of the temperature inside the metal tube 31A. Temperature Temperature TemperatureTime at Bottom at middle at top(min.) (°C.) (°C.) (°C.)______________________________________5 165 156 1676 177 168 1767 181 178 1868 189 186 1929 197 192 19710 198 198 201______________________________________
TABLE 2______________________________________The temperature as a function of heating time inside metal tube 24 Time Temperature at (min.) middle (°C.)______________________________________ 0 27 1 78 2 120 3 140 4 156 5 160 6 172 7 183 8 187 9 191 10 197______________________________________
The speaker 22 was mounted inside the wood box 23 which had a circular opening (not shown) on top to allow the upward propagation of the sound waves to inside tube 24. The wood box 23 was painted with epoxy glue to avoid the release of volatile compounds that could interfere with the vacuum level. The box 23 was connected to the inside tube 24 through aluminum flange 26 whose circular base covered the opening of the wood box 23. The aluminum flange 26 also had an outside indentation 26A for an o-ring to hold the lower rubber membrane 25 where the inside tube 24 is fitted. The speaker 22 was controlled by a frequency generator and a power amplifier located near the experimental apparatus 20 (not shown).
As shown in FIG. 6, the vacuum system 60 included a vacuum pump 61 connected to the inside tube 24 by thick wall flexible vacuum hoses 62, 63, 64, 65 and 66. Ball valves 67, 68, 69, 70 and 71 were used to control the gas flow in and out of the inside tube 24. Vacuum feedthroughs 72, 73, 74 and 75 were sealed in a similar way to the pins 27. A supply 76 of gas (argon) was provided along with a vacuum gauge 77 and a pressure gauge 78. Filters 79 were provided for vacuum lines 64 and 75.
Safe handling of aluminum powder is essential because of the potential risk of an explosion. Aluminum reacts instantaneously with oxygen to form a thick film of aluminum oxide on the surface of the aluminum when exposed to the atmosphere. The oxide layer is stable in air and prevents further oxidation of underlying aluminum. However, if fine aluminum powder, usually less than 44 microns (325 mesh), is suspended in air and heated to reach the ignition point, the burning extends from one particle to another with such rapidity (rate of pressure rise in excess of 20,000 PSi/Sec) that a violent explosion results (Aluminum Association Handout, "Recommendation for Storage and Handling of Aluminum Powders and Paste", TR-2). It has been reported that the proportion of aluminum powder required for an explosion is very small (45 g/m 3 ). Aluminum dust will ignite with as little as 9% oxygen present (the balance being nitrogen; or 10% oxygen with the balance helium; or 3% oxygen with the remainder carbon dioxide. Very small amounts of energy are required to ignite certain mixtures of aluminum powder and air. In some case energy as low as 25 millijoules can cause ignition.
Some basic safety rules of handling aluminum powder which are recommended by the Aluminum Association are:
Rule 1: Avoid any condition that will suspend or float powder particles in the air creating a dust cloud. The less dust suspended in the air, the better.
1) Keep all containers closed and sealed. When a drum of aluminum powder is opened for loading or inspection, it should be closed and resealed as quickly as possible.
2) In transferring aluminum powder, dust clouds should be kept at an absolute minimum. Powder should be transferred from one container to another using a non-sparking, conductive metal scoop with as little agitation as possible. Handling should be slow and deliberate to hold dusting to a minimum. Both containers should be bonded together and provided with a grounding strap.
3) In mixing aluminum powder with other dry ingredients, frictional heat should be avoided. The best type of mixer for a dry mixing operation is one that contains no moving parts, but rather affects a tumbling action, such as a conical blender. Introduction of an inert atmosphere in the blender is highly recommended since dust clouds are generated. All equipment must be well-grounded.
Rule 2: When possible, avoid actions that generate static electricity, create a spark or otherwise result in reaching the ignition energy or temperature.
1) Locate electric motors and as much electrical equipment as possible outside processing rooms. Only lighting and control circuits should be in operating rooms. All electrical equipment must meet National Electrical Codes for hazardous installations. This includes flash lights, hazardous portable power tools, and other devices.
2) Use only conductive material for handling or containing aluminum powders.
3) No smoking, open flames, fire, or sparks should be allowed at operation and storage areas or dusty areas.
4) No matches, lighters, or any spark-producing equipment can be carried by an employee.
5) During transfer, powder should not be poured or slid on non-conductive surfaces. Such actions build up static electricity.
6) powder should always be handled gently and never allowed to fall any distance because all movement of powder over powder tends to build up static charges.
7) Work clothing should be made of smooth, hard-finished, closely woven fire resistant/fire retardant fabrics which tend not to accumulate static electric charges. Trousers should have no cuffs where dust might accumulate.
8) Bonding and grounding machinery to remove static electricity produced in powder operations are vital for safety.
9) All movable equipment, such as drums, containers, and scoops, must be bonded and grounded during powder transfer by use of clips and flexible ground leads.
Rule 3: Consider the use of an inert gas which can be valuable in minimizing the hazard of handling powder in air.
However, in the three general rules, Rule 3 is the most important safety precaution method for the process of aluminum powder coating on fibers, which is the key step in the fabrication of CFMMC, because the coating operation is preferably performed in aluminum cloud at 170° C. By pumping a vacuum and introducing argon repeatedly, oxygen can be reduced to the safe volume fraction.
The amount of oxygen left inside the inside tube 24 can be determined by the ideal gas law:
PV=nRT (5-1)
First, assume that after pulling a vacuum on the tube 24 of volume V at temperature T to decrease the pressure from one atmosphere to a pressure P o , only n o moles of O 2 and 4n o of N 2 are left in the tube 24. Applying the equation (5-1) gives:
5n.sub.o =P.sub.o (V/RT) (5-2)
Second, assume that n 1 moles of Ar are introduced to the tube 24 to go back to atmospheric pressure. The total number of gas moles n is given by n=5n o +n 1 . Applying the equation (5-1) again to get:
5n.sub.o +n.sub.1 =(1 atm) (V/RT) (5-3)
Combining equation (5-2) and (5-3), and rearranging it gives the Ar/O 2 ratio as:
n.sub.1 /n.sub.o =5((1/P.sub.o)-1) (5-4)
Table 3 gives the Ar/O 2 ratio and oxygen volume percentage for different vacuum levels.
TABLE 3______________________________________Oxygen volume percentage as a function of different vacuum levels.Vacuum Number of Oxygenlevel Ar/O.sub.2 O.sub.2 volume(torr) ratio moles percentage______________________________________76.3* 49 28.02 × 10.sup.-3 2.0%36.5 99 14.55 × 10.sup.-3 0.96%24.0 150 9.76 × 10.sup.-3 0.65%11.5 328 4.54 × 10.sup.-3 0.30%0.76 4995 0.30 × 10.sup.-3 0.02%______________________________________ *If pump twice to reach the vacuum level 76.3 torr again, then: Ar/O.sub.2 ratio: 499 Number of O.sub.2 moles: 3.03 × 10.sup.-3 Oxygen volume percentage: 0.20%
As a conclusion, the oxygen amount present can be controlled by the vacuum level reached in the tube 24 before introducing argon to prevent the explosion of aluminum powder. On the positive side, argon adsorption to surface of aluminum powder is beneficial for a limited time following re-entry to air.
In addition, worker protection must be used for handling aluminum powder. Goggles and mask are strongly recommended.
The matrix material used in this experiment is pure aluminum metallic powder (atomized) manufactured by Valimet Inc. (Stockton, Calif.). The powder had a spherical shape with an average of 5.5 microns in diameter. The reinforced fiber was a continuous high-strength, PAN-based carbon fiber manufactured by Hercules Inc. (Magna, Utah). The filament had a size of 8 microns in diameter with round shape. There were 3000 filaments per tow which had 3587 MPa in terms of tensile strength. The reinforced components used directly were prepreg tapes of nylon-coated carbon fibers produced by the powder prepregging system at the Composite Materials and Structures Center, East Lansing, Michigan (CMSC), rather than the loose tow fibers. Type A prepreg was the regular product of CMSC for the production polymer matrix composites, which was processed at 170° C. to meet the polymer coating. Type B prepreg was a special product for the production of C/Al composite using the method of the present invention, which was processed at 165° C. to meet the polymer coating. The processing temperature of the polymer coated fiber prepreg would range from 150° C. to 250° C. depending on the polymer selected. The properties of the type A and type B prepregs are shown in Table 4.
TABLE 4______________________________________Properties of materials used in the experimentMaterial/Property Value______________________________________Hercules AS-4 Carbon FibersDiameter (microns) 8.0Specific gravity (g/cm.sup.3) 1.80Tensile strength (MPa) 3.587Tensile modulus (GPa) 235PolyamideAverage particle size (μm) 10.0Specific gravity (g/cm.sup.3) 1.02Melting point (°C.) 175Surface tension (mJ/m.sup.2) 30.0Aluminum PowdersAverage particle size (μm) 5.5Density (g/cm.sup.3) 2.69Apparent density (g/cm.sup.3) 0.6Chemical composition:Aluminum 99.7%Iron 0.18%Silicon 0.2%Type A PrepregsProcessing temperature (°C.) 170Type B PrepregsProcessing temperature (°C.) 165______________________________________
The procedures involved in production of aluminum powder coated prepreg precursors were
1) The polymer prepreg tapes were cut into 5 cm pieces.
2) The prepreg tapes were fixed inside the metal tube 31A with spring clips as shown in FIG. 5.
3) The metal tube 31A was hung on the pins 4B inside the glass tube.
4) 3-5 g of aluminum powder was deposited on the bottom membrane 25.
5) The inside tube 24 was fitted on the top of the aluminum flange 26.
6) The top membrane 25 was placed in position with the help of the o-ring.
7) All of the electric wires and vacuum hoses were connected properly.
8) The aluminum lid 28 was placed on the outer tube 21.
b 9) The vacuum pump 61 was operated until the pressure inside the tube 24 was reduced to below 3 in Hg.
10) Argon was introduced slowly to one atmosphere (14.7 psig).
11) Steps 9 and 10 were repeated.
12) The heater 31 was turned on and heated for 6 minutes for type A prepreg 32 and 3 minutes for type B prepreg 32.
13) The frequency generator or speaker 22 and the power amplifier was turned on to fluidize the aluminum powder for 3 minutes for type A prepreg 32 and minutes for type B prepreg 32.
14) The heater 31 was turned off after heating 8 minutes.
15) The prepreg 32 was removed in reverse order of steps 1-8 after the powder settled down and the temperature cooled down.
The aluminum-coated carbon fiber precursors then were consolidated by vacuum hot pressing in a conventional vacuum furnace such as furnace 40 using a MTS-810 Material Test System (Minneapolis, Minn.). The procedures and processing parameters used were:
1) Align dozens of prepreg 32 layers in mats.
2) Cut the aligned prepreg 32 into 2 cm long and 1 cm wide.
3) Wrap the aligned and trimmed prepreg with two pieces of aluminum foils in transverse direction.
4) Put a layer of boron nitride paste evenly on the outside of the aluminum foils.
5) Place the wrapped and pasted precursors between two pieces of thin alumina plates.
6) Place the sample in the fixture.
7) Put the fixture on the bottom platen inside the pressing furnace.
8) Press the top platen on the sample with pressure of a little more than zero.
9) Close the furnace and pump vacuum to less than 2×10 -5 Torr.
10) Ramp the temperature to 420° C. in 15 minutes.
11) Keep the temperature at 420° C. for one hour to evaporate the binder material (nylon).
12) Increase the temperature to 570° C. in 5 minutes.
13) Keep the temperature at 570° C. for 5 minutes.
14) Press the sample under 30 MPa at 570° C. for 30 minutes.
15) Release the pressure and decrease the temperature to 400° C. in 5 minutes.
16) Cool the sample naturally to room temperature.
17) Extract the CFMMC after the furnace cooled.
The mechanical properties of the composite were measured using United Testing System SFM-20. A three-point bending test was performed. The original composite was approximately a 1 mmthick×12 mm wide×21 mm long plate for the sample which was made from type A prepreg, and a 2 mm thick×12 mm wide×21 mm long plate for the sample which was made from the B prepreg. The plates were cut into 1.65 mm wide specimens by a low speed diamond saw after the composite plate was trimmed to eliminate unconsolidated materials at the edges, and cleaned to remove the stop-off materials. Referring to FIG. 7, the flexural strength and modulus of the composite was evaluated by following equations:
S.sub.Fc =3PL/2bd.sup.3 (5-5)
E.sub.Fc =Pl.sup.3 /4δbd.sup.3 (5-6)
Where S Fc =the flexural strength of the composite
P=the loading
L=the span
b=width of the specimen
d=thickness of the specimen
E Fc =the flexural modulus of the composite
δ=deflection increment at midspan
The flexural strength of the composite from the three point bending test can be compared with the theoretical value calculated from equations (3-3) and (5-7) (Weeten, J. W., et al., Engineers' Guide to Composite Materials, Carnes Publication Services, USA (1987)) which is derived from the rule of mixtures and the contribution of the matrix is neglected.
S.sub.Fc =3V.sub.f S.sub.Tf /(1+S.sub.Tf /S.sub.Cf) (5-7)
wherein S Fc =the flexural strength of the composite
STf=the tensile strength of the fiber
S Cf =the compression strength of the fiber
V f =the fiber volume fraction
If S Cf is not known, S Cf =0.9 S Tf is a good approximation for graphite fiber/matrix composites.
The broken specimens from the mechanical test then were mounted, polished and examined by Olympus PME 3 Metallograph. The fracture surfaces of the specimens were examined using Hitachi S-2500C scanning Electron Microscope (SEM) (Japan).
The fiber volume fraction was determined by counting the fibers observed on a composite cross-section and using the relation:
V.sub.f =(N×A.sub.f)/A.sub.t
Where V f =the fiber volume fraction
N=the number of fibers
A f =the average cross-sectional area of a single fiber
A t =the total cross-sectional area
This work was done by Optical Numeric Volume Fraction Analysis Software (Michigan State University, East Lansing, Mich.).
FIGS. 8A and 8B and 9A and 9B show scanning electron microscope (SEM) images of type A prepreg and type B prepreg 32 at different magnifications. The prepregs, which were produced by the Composite Materials and Structures Center at Michigan State University, were used to make the CFMMC. For type A prepreg 32, it is apparent from these micrographs that there is satisfactory coating with nylon on the carbon fibers in the prepreg although there are some droplets formed on the fibers. The fibers were almost spread uniformly while some fibers contacted together and some fibers crossed. For type B prepreg 32, the nylon particles just begin sintering or even sintering had not occurred. So some nylon particles were lost during handling and the fibers were not held together by nylon to form tape.
FIGS. 10A and 10B and 11A and 11B show two types of SEM images of C/Al composite precursors at different magnifications. The precursor has a satisfactory aluminum powder pick-up. The successes include: 1) the amount of aluminum powder is large enough; 2) the adhesion between the fiber and the powder is strong enough to survive handling; 3) the distribution of the aluminum powder is uniform for type A precursors. For type B precursors, fiber coating is uneven because of the existence of some uncoated fibers. The disadvantage is that the fiber contacting and crossing can still be found, which is due to the fabrication of nylon coated fiber prepregs.
The results of the mechanical test for the continuous high strength carbon fiber reinforced aluminum matrix composite materials are shown in Table 5 and FIGS. 12 and 13. The flexural strength of the composite is 335 MPa for sample A (343 MPa for sample Al and 328 MPa sample A2) and 285 MPa for sample B as compared to 82.8 MPa for the unreinforced pure aluminum matrix. The flexural modulus of the composite is 108 GPa for sample A (122 GPa for sample Al and 94 GPa for sample A2) and 74 GPa for sample B as compared to 69 GPa for the unreinforced pure aluminum matrix.
FIGS. 14A and 14B and 15A and 15B show the typical optical micrographs of the cross section of the C/Al composites, which were used to determine the fiber volume fraction. It was found that the fiber volume fraction is 50% for the sample from the type A prepreg and 20% for the sample from the type B prepreg. Using the above value of fiber volume fraction and the tensile strength and modulus value of carbon fibers and aluminum matrix from Table 5, the flexural strength of the rule of mixtures at these fiber volume fractions were calculated to be 2549 MPa for sample A and 1019 MPa for sample B. The flexural strength of the composite is 13% of the rule of mixtures for type A and 28% for type B. The modulus of the rule of mixtures at these fiber volume fractions was determined to be 151 GPa for type A and 112 GPa for sample B. The modulus of the composite is 71% of the rule of mixtures for type A and 66% for type B.
TABLE 5______________________________________Mechanical properties of Example 1 composites at room temperatureSpecimens A1 A2 B1______________________________________Span, mm 18.0 18.0 18.0(in.) (0.71) (0.71) (0.71)Width, mm 1.65 1.65 1.65(in.) (0.065) (0.065) (0.065)Thickness, mm 1.07 1.13 1.93(in.) (0.042) (0.0445) (0.076)Yield load, N 0.08 0.54 0.11(lbs) (0.0183) (0.122) (0.0244)Peak load, N 23.84 25.61 64.90(lbs) (5.359) (5.756) (14.587)Yield STR 1.2 0.7 0.5MPa (Psi) (170.1) (101.1) (69.25)Flexural STR 343 328 285MPa (Psi) (49775) (47622) (41380)Fiber 50 50 20Fraction (%)% ROM 13 13 28StrengthFlexural 122 94 74Modulus, GPa (17625) (13554) (10754)(Ksi)% ROM 80 62 66ModulusStrain at 0.6543 0.5548 1.044failure(%)______________________________________
FIGS. 16A and 16B and 17A and 17B show the optical micrographs of the longitudinal section of type A and type B. From these Figures, it is obvious that the fiber-matrix interface is smooth with no discontinuities observed even at higher magnification. This implied that the fiber-matrix bonding is good with no excessive interface reaction and no fiber damage. However, these micrographs show that some carbon fibers contact together to form the fiber clusters, especially for type A. FIGS. 18A and 18B and 19A and 19B show the SEM fractographs of type A and type B. It can be seen that the dispersed fibers were not pulled out while the clustered fibers were pulled out. The fractographs show that the aluminum powders were sintered well generally while a few of unsintered aluminum powders can be found in type B in FIG. 19B at arrow. This could be due to the fact that these powders were located in a local void where the pressure could not reach them.
The new fabrication process of composite precursors was capable of picking up the desired volume fraction of metal matrix. The distribution of fine metal powder around the reinforcing fibers was uniform. The precursor tapes with the aluminum powder were almost as flexible as the reinforcing fiber tow with good handling properties. The polymer worked well as the binder and hence no significant aluminum powder loss was found during the layup procedure prior to consolidation. This suggested that the adhesion of the aluminum powder to the carbon fibers was strong. For type A prepreg 32, the formation of the fiber clusters played two roles. First, the aluminum precursors were easy to handle during the layup procedure because the fibers do not move relative to one another. Secondly, it made the fibers distribute unevenly.
There are four key factors which resulted in the success of composite precursor production.
1) The spreader 12 which worked on the principle of acoustic energy was able to spread collimated fiber tows into their individual filaments. It worked best at the natural frequency of the reinforcing fibers.
2) The apparatus 20 which utilized acoustics to provide a buoyant force to the powder was a stable entrainment system which provided an aerosol of constant aluminum powder concentration for extended periods of time. It operated best at its natural frequency.
3) The use of fine metal powder roughly of the order of dimensions of the reinforcing fibers made the distribution of the matrix around each fiber uniform.
4) Polyamide polymer worked very well as a binder to adhere the aluminum powder on the carbon fibers at proper temperature.
However, the presence of fiber clusters in the prepreg 32 was a remaining problem for the quality of the precursors. The impregnated fibers show a tendency to cluster in bundles in the heater. The preferred configuration of the prepreg 32 is the array of fiber-matrix cluster, each cluster diameter ranging from that of a single fiber to multiple fibers (most cluster diameters are between 10-50 microns). In the heater, the coalescence of the polymer on the fibers goes through three steps: the heating up of fibers and the particles; interparticle sintering between adjacent particles until a film forms on the fiber surface; and, finally, the formation of a stable configuration of axisymmetric or non-symmetric droplets. In the first step, the temperature of the powder-impregnated fiber tow is raised by convection and radiation to a value greater than the melting or softening point of the polymer particles. Then, interparticle sintering begins with a neck formation between adjacent particles. The neck grows till the particles coalesce into one. Interparticle sintering time (defined to be the time when the interparticle bridge is equal to the particle diameter) is primarily influenced by the temperature, the polymer viscosity and the particle size. The work required for a shape change is equal to a decrease in surface energy. Interparticle sintering leads to the formation of a film which breaks up to form droplets on the fiber. The transition from a polymer film on the fiber surface to droplets is driven by the finite wetting abilities of most thermoplastics. These droplets are of varying shape and symmetry with respect to the fiber axis. The shape of these droplets changes with time to equilibrium configuration which can be axisymmetric or non-symmetric depending on droplet volume and the influence of gravitational forces. If in the case of a spread fiber tow in which the impregnated fibers are in intermittent contact with each other, capillary forces between adjacent fibers may make film formation thermodynamically favorable. The final configuration depends on interfiber distances and droplet sizes in addition to surface tension forces. Therefore, there are three ways to improve the quality of prepregs 32.
1) Improve the spreader 20 operation. Interfiber distances have to be larger to avoid the bonding of adjacent fibers by the droplets. It is advantageous to have good spreading so that individual fibers are exposed thereby reducing the average cluster diameter.
2) Use a particular polymer as the binder for a given fiber. Interparticle sintering and film formation are influenced by viscosity, surface tension and particle size of the polymer. Surface tension of most polymers lies between 20-50 dynes/cm whereas viscosity can vary by orders of magnitude. Hence there is an optimum polymer for a given fiber.
3) Control the temperature of the heater 31 and the speed of the fiber motion. For a given fiber-polymer system and a given speed of the fiber motion, interparticle sintering and the film formation are influenced only by the temperature of the heater. If the temperature is too low, interparticle sintering will not occur and the prepreg tape cannot be formed. On the other hand, if the temperature is too high, the droplets and fiber clusters will form, which is not desired for the production of the aluminum precursors. However, there are proper temperatures at which the interparticle sintering has occurred but the film has not formed completely. In this case, it is possible to get high quality of prepreg 32 because the particle sintering can hold fibers as prepreg tape by periodic fiber-to-fiber contact. In the metal powder coating chamber 20, a greater fraction of the fiber surface is exposed to the cloud of the fine metal powder before the sintering is completely finished.
Type B prepreg was an attempt to produce a better polymer dispersion. It is obvious that 165° C. is too low to be the best processing temperature because the sintering has not occurred for some nylon particles which will be lost during handling and the prepreg 32 cannot be formed. However, the mechanical property has shown the distinct improvement for type B prepreg 32.
Flexural strength and modulus of 335 MPa and 108 GPa for type A, 285 MPa and 74 GPa for type B were obtained when the precursors were vacuum hot pressed at 570° C. for 30 minutes under 30 MPa pressure. It corresponds to a value of 13% and 28% of the rule of mixtures strength, 71% and 66% of the rule of mixtures modulus, respectively. The lower measured strength and modulus may be due to several factors.
1) The distribution of the fibers in the composite was not always uniform, and this affected the maximum fracture load. Some areas had a high density of fibers and others had a low density. There are some fiber clusters (fiber-to-fiber contact) in the composite although type B prepreg 32 is better than type A prepreg 32. Fiber clusters in type B prepreg 32 were smaller than in type A prepreg 32. Thus a larger fraction of the fibers in type B prepreg 32 were completely surrounded by matrix. The micrographs of the fracture surface showed fiber pullout in the fiber cluster areas, which suggested that tow of fibers did not fully work as a reinforcement. The high magnification fractographs (FIGS. 19A and 19B) showed that where fibers were in direct contact with each other, the fracture in fibers started at the fiber-fiber interface. This suggests that fibers in direct contact lead to premature fracture. This can explain why the strength of type A prepreg 32 is less than the strength of type B prepreg 32 in terms of the percentage of the rule of mixtures. So it is the poor distribution of the fibers that mainly cause the lower strength.
2) The fiber coating with aluminum powders is uneven for type B prepreg 32, and this may affect the load transfer efficiency at the interface. As mentioned before, type B prepregs 32 were processed at 165° C. and some nylon powder particles were not as evenly distributed due to inadequate sintering at the lower processing temperature. This resulted in the existence of portions of the fibers without any coating. These uncoated regions resulted in some voids in the fiber-matrix interface, where the powder particles were not completely consolidated due to the fact that the pressure could not reach these regions during consolidation. The bonding in these regions is very poor because some unsintered aluminum powders can be found (Refer to FIG. 19B at arrow). Therefore, since some portions of the fibers cannot transfer elastic loading to the matrix, the stiffness of the composite is reduced. It is the uneven fiber coating that may cause the lower modulus of type B prepreg 32 than that of type A prepreg in terms of the percentage of the rule of mixtures. However, since the modulus values are close, they may also represent experimental variation.
3) The optimal consolidation parameters can be determined. Higher temperatures and longer times give lower strength because of brittle carbide formation at the interface of the aluminum and the carbon fibers. Lower temperatures and shorter times give lower strength due to poor bonding strength at the inter-aluminum matrix. The occurrence of low strength may be due to poor bonding strength of the aluminum matrix under higher pressures or damage of the reinforced fibers under high pressures. Therefore, the optional processing parameters are selected to get the maximum in strength of composite.
4) The matrix metal and the characteristics of the reinforcing component have important influence to the strength of the composite. As mentioned earlier, most aluminum matrix composites are produced by aluminum alloy. So the use of pure aluminum could be a factor because pure aluminum has lower strength and is more reactive than aluminum alloys. Regarding the reinforcing component, high modulus carbon fibers have a high content of crystallized carbon and good chemical stability but high cost because they were carbonized at 2000°-3000° C. In contrast high strength carbon fibers were carbonized at 1000°-1500° C., so these fibers are cheaper but more reactive with aluminum than high modulus carbon fibers. In view of the lower costs, the use of high strength carbon fibers, as described in this investigation, should be significant in the production of these composites although the strength is lower.
5) Increasing fiber volume fraction in the composite is a way to increase the strength of the composite. It is well established that the strength of composite is a function of fiber volume fraction in direct proportion. Hence reducing the time of aluminum powder fluidizing can increase the fiber volume fraction and the strength of composite.
6) Selecting a better polymer as the binder is another way to increase the strength of composite.
The binder plays a very important role in the new fabrication method of CFMMC. A good binder improves the distribution of the fibers and the matrix powder during the production of the precursors. It is more important that the binder not promote interfacial reactions. Therefore, the polymeric binder must fulfill a succession of requirements as it proceeds through the method steps.
1) It must be thermoplastic to be a binder at high temperature.
2) It must provide suitable viscosity and surface tension and flow properties.
3) It must be capable of being removed in vacuum furnace 40 by controlled pyrolysis without disrupting the particle arrangement.
4) It must have a suitable melting point temperature and be stable around the melting point temperature (Woodthorpe, J., et al., J. Mater. Sci. 24 1038 (1989).
5) It must not react with aluminum and carbon fibers at high temperature, so polymers without oxygen may be better.
The mechanisms of the pyrolytic removal of binder must be understood in order to understand the last requirement. There are three mechanisms for the pyrolytic removal of binder, which are evaporation, thermal degradation and oxidative degradation (Wright, J. K., et al., J. Am. Ceram. Soc. 72(10) 1822 (1989); and Edirishinghe, M. J., British Ceramic Proceedings, 45 45 (1990)). Evaporation is the dominant mechanism when low molecular weight waxes are used as the binder. Here the organic species do not undergo chain scission and are independent of the atmosphere used. Thermal degradation of the binder is carried out in an inert atmosphere where oxygen is absent. The decomposition of the polymer takes place entirely by thermal degradation processes by a free-radical reaction. The predominant process is the formation of lower-molecular-weight substances by intramolecular transfer of radicals, resulting in random chain scission and a reduction in molecular weight. Molecular fragments less than a critical size are lost by evaporation. The presence of oxygen during binder removal super impose on thermal degradation an additional reaction with polymer and metal powder. The reaction products may or may not be volatile substances.
Polyamide was used as the preferred binder, and it was believed to be removed completely by thermal degradation in the vacuum furnace. In fact, polyamide is not necessary the best choice as the binder for the C/Al system because it contains oxygen. It was mentioned earlier that the presence of oxygen catalyzes the formation of aluminum carbide at carbon/aluminum interfaces. Thermoplastic polymers such as polystyrene, polyethylene, polypropylene can be more suitable to be the binder because they fill the demand: thermoplastic, proper melting point, are removable, and are without oxygen. Selecting a suitable binder can be an effective method to improve the quality of composite.
The following conclusions were reached.
1) The method works well for the production of CFMMC. The spreading width is limited only by the length of the spreader over which the fiber tow passes and the spreader 12 width under a set of optimum conditions. However, the fibers tend to collapse to a narrow width after passing through the spreader, which needs to be corrected.
2) The fluidization of fine aluminum powder was successful by using the acoustic energy coming off a speaker 22 through rubber membranes 25. The aerosolizer is efficient with the uniform distribution of aluminum powder around the fibers.
3) Heating nylon-coated carbon fiber prepreg 32 to a temperature above the softening point of nylon created a sticky polymer host for fine aluminum powder. The perfect adhesion of aluminum powder to carbon fibers was achieved by making nylon serve as the binder. However, other polymers such as polystyrene, polyethylene, polypropylene can be more suitable binder for C/Al system because these polymers do not contain oxygen and are more easily volatilized.
4) The strength of the C/Al composite was lower than that expected from the rule of mixtures. It may be mainly attributed to the presence of fiber clusters due to imperfect fiber spreading.
EXAMPLE 2
The binder may not play an important role as seen from the micrographs of the prepregs 32 and aluminum precursors. This implies that the binder is not necessary since the electrostatic forces can make the aluminum powder stick to the carbon fibers. Without the binder, the fiber cluster does not form and the quality of composite can be improved.
Continuous processing of CFMMC by not using the polymer binder can also be accomplished. This is possible since metal powders form oxide coatings that can hold a static charge strong enough to attract the metal powder particle to the fiber and hold it in place long enough to be consolidated. This static attraction has been demonstrated in two ways: 1) powder aggregates are observed on the bottom of the aerosolizing chamber, indicating that the fine powder can hold a static charge and 2) as a result of hanging sections of bare carbon fiber tows in the aerosolizing chamber, the fibers were evenly coated with the powder.
Subsequently, sections of bare fiber tows coated in this way were laid up in a stack and consolidated with minimum handling. Some layers that had lesser amounts of powder had additional powder sprinkled on top of the layer. These were consolidated in the conventional way by vacuum hot pressing. This sample had very evenly spaced fibers, with less than 2% of the fibers being in contact with each other in any particular cross section investigated. Some pullout of the fibers on the order of the fiber diameter was observed in the fracture surface of a bend specimen. The CFMMC cross-section is shown in FIG. 20. Since the polymer binder is not required the processing is less complex, since no vacuum burnout of the polymer using furnace 40 is needed.
The procedure involved in the production of aluminum powder coated prepreg precursors was
1) The prepreg tapes (bare carbon tows) were cut into 5 cm long pieces.
2) The prepreg tapes were suspended inside the metal tube 31A with spring clips as shown in FIG. 5.
3) The metal tube 31A was hung on the pins 24B inside the glass tube.
4) 5-8 gm of aluminum powder was deposited on the bottom membrane 25.
5) The inside tube 24 was fitted on the top of the flange 26.
6) The top membrane 25 was placed in position with the help of the o-ring.
7) All the electric wires and vacuum hoses were connected properly.
8) The aluminum lid 28 was placed on the outer tube 21.
9) The vacuum pump 61 was operated until the pressure inside the tube 24 was reduced to below 3 in Hg.
10) Argon was slowly introduced to one atmosphere (14.7 psig).
11) The frequency generator or speaker 22 and the power amplifier was turned on to fluidize the aluminum powder for approximately 5 minutes.
Additional powder was sprinkled on top of some layers that had lesser amounts of powder. The aluminum coated carbon fiber precursors were consolidated by vacuum hot pressing. The steps involved were:
1) Align dozens of prepreg layers in mats.
2) Chop off the aligned prepreg in 2 cm long and 1 cm wide pieces.
3) Wrap the prepreg with aluminum foil.
4) Apply boron nitride paste evenly on the inner surface of the fixture.
5) Place the sample in the fixture.
6) Put the fixture on the bottom platen inside the pressing furnace.
7) Press the top platen on the sample with pressure of a little more than zero.
8) Close the furnace and pump vacuum to less than 2×10 -5 Torr.
9) Increase the temperature to 570° C. in 30 minutes.
10) Press the sample under 30 MPa at 570° C. for 45 minutes.
11) Release the pressure and decrease the temperature to 400° C. in 5 minutes.
12) Extract the specimen after the furnace reaches room temperature.
The density and coefficient of thermal expansion "α" of the composite were measured. "α" was measured using a Dilatometer and Archimedes principle was used to measure the density. Mechanical properties of the Example 2 composite were also measured by using United Testing System. The results are given in Table 6.
TABLE 6______________________________________Physical and Mechanical Properties of Example 2 Composite:2.28 gm/cm.sup.3Coefficient of Linear Thermal Expansion "α" - 1.793 ×10.sup.6 /°C.Mecanical Properties of the Composite at Room TemperatureSpecimen Sample 1* Sample 2*______________________________________Span, mm 18.0 18.0(in) (0.71) (0.71)Width, mm 2.90 3.12(in) (0.114) (0.123)Thickness, mm 0.57 0.025(in) (0.022) (0.635)Yield Load, lb N/A N/APeak Load, lb 4.731 4.598Yield Stress, psi N/A N/AFlexural Strength, 91324 63697psi 629.68 439.19(MPa)Flexural Modulus, psi 14742630 12691180(GPa)* 101.65 87.51% ROM Strength 78.55 67.63Strain Failure (%) 0.6554 N/A______________________________________
For bending tests of composites, the span-to-depth ratio is recommended to be at least 16:1. This ratio shall be chosen such that failures occur in the outer fibers of the specimens, due only to the bending moment. For highly anisotropic composites, shear deflections can seriously reduce the modulus measurements. In this study, a ratio of 32:1 is a standard that should be adequate to obtain valid modulus measurements.
The consolidated sample was approximately 30 mm×12 mm×3 mm plate, that was cut into 2 mm wide specimens by a low speed diamond saw after the composite plate was trimmed off to eliminate unconsolidated materials at the edges.
For Alpha measurements, the original sample was cut into 25.4 mm×12.7 mm×3 mm block. The alpha value determined from the Dilatometer experiment is 1.793×10 -6 /° C. and the density of the material is 2.28 gm/cm 3 . The porosity of the material is found to be less than 1%. Fiber volume fraction was measured by counting the fibers observed on a composite cross section and it was around 40-50%.
FIGS. 23, 24, 25, 26, 27 and 28 show the optical micrographs of the transverse and longitudinal sections of the composite at different magnifications. From the FIG. 25, it was clear that there was no matrix material in one part of the specimen. This may account for the porosity determined from the density measurement.
FIG. 26 shows the even distribution of fibers with very few fibers contacting each other. From these Figures, it is obvious that the fiber--matrix interface is smooth with no apparent discontinuity in the interface, even at higher magnifications. This implied that the fiber-matrix bonding is good with no interface reaction and no fiber damage. However, these micrographs show less than 2% of the fibers being in contact with each other in any particular cross section investigated. In addition, some fiber pull out on the order of the fiber diameter was observed in the fracture surface of a bend specimen. FIGS. 27 and 28 show the SEM fractographs of the composite of FIG. 16
Main features of this new fabrication technique are:
1) It was capable of picking up the desired volume fraction of metal matrix.
2) The distribution of the matrix around the fibers was uniform.
3) Micrographs showed that the fiber--matrix bonding was good.
4) The processing is less complex since the polymer binder is not required and no vacuum burnout of the polymer using furnace 40 is needed.
As shown in FIG. 21 for system 80, the fiber tow is spread in spreader 12, coated in the apparatus 20 with metal powder and then immediately pressed between heated rolls 50, such as rolls 50A, 50B and 50C, at the consolidation temperature in a condition that provides adequate pressure for sintering. The exit side of the rollers 50 provides a consolidated product, such as a foil or a wire or rod, as illustrated in FIGS. 21, 21A to 21C. The system 80 is enclosed in enclosure 81. The prepreg 101 is filled from spools 82, 83 and 84 to provide composites 102A, 102B or 102C. With more complicated roller geometry, more complex beam shapes can be fabricated. Thus the tows of fibers are coated simultaneously and guided to proper position at the consolidation rolls 50, so that larger thicknesses can be built up, or more complex shapes can be fabricated as shown in FIG. 21.
With a scalping operation on aluminum shapes occurring prior to the consolidating rolls, a thin coating of fiber reinforced material can be applied, as shown in FIG. 22. The system 90 is provided in an enclosure 91. The core 92 is scraped by cutters 93 and then the metal coated precursor is compressed onto core 92 by rollers 96. The prepreg 32 is fed from spools 94 and feed rolls 95. The product is composite 103.
The continuous fiber tows coated with polymer and matrix powders could be subsequently chopped for consolidation in desired geometries, and thus provide coated chopped fibers with evenly distributed matrix. In addition consolidated continuous fiber products made using the above procedures could be chopped for subsequent consolidation in desired geometries. In addition, chopped fibers could be coated with polymer and/or matrix powders to provide chopped coated fibers for subsequent consolidation.
It is intended that the foregoing description is only illustrative of the present invention and the present invention is limited only by the hereinafter appended claims. | 4y
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TECHNICAL FIELD
The present disclosure relates to a durable chemical treatment to improve the adsorbency of activated carbon, which may be exposed to liquids such as rain, sweat, water, and the like. The treatment comprises a fluorocarbon that is applied at low add-on levels. The treated activated carbon is useful in a number of applications, including air filters, gas masks, solvent recovery devices, and chemical and biological protective gear.
BACKGROUND
Activated carbon comes in a variety of forms. Initially, it was made in the form of granules or powder. More recently, it has been made in the form of a fabric known as charcoal cloth or carbon cloth. Activated carbon is used to adsorb undesirable components from the atmosphere or from a local environment. However, it is known that the effectiveness of activated carbon can be comprised by other components, not necessarily undesirable per se, that saturate the activated carbon and prevent it from adsorbing the undesirable components. The most common component that leads to such saturation of activated carbon is water.
Activated carbon is used in clothing to provide protection against undesirable components, but when such clothing is wet, the effectiveness of the activated carbon in adsorbing the undesirable component is drastically reduced. Also, the additional weight of such wet clothing presents a further disadvantage. To overcome this problem, carbon cloth is often used as one component in a composite structure that includes a relatively waterproof, outer fabric layer.
There is a problem associated with using such a waterproof barrier fabric as either the outer layer of a carbon cloth composite or the inner layer of such a composite. Because the barrier fabric cannot prevent moisture condensation on the activated carbon, liquids (e.g, sweat or water) can reach the activated carbon and inhibit its adsorption ability. Once the moisture has condensed on the surface of the activated carbon, the barrier fabric actually traps the moisture on the activated carbon, preventing evaporation. The so-called barrier fabrics are especially incapable of performing their intended role—that is, preserving the adsorptive properties of the activated carbon—in the laundering process, where the composite is exposed not only to large amounts of water, but also to detergents, soil, and other contaminants.
U.S. Pat. No. 4,732,805 to Maggs describes treating activated carbon with a fluorocarbon resin at add-on levels of 5% to 10% of the weight of the carbon cloth. The preferred fluorocarbon resin is polytetrafluoroethylene (PTFE) having a primary particle size of 0.1 microns. A major shortcoming with this approach, however, is that the PTFE particles, which are by their nature non-sticking, do not bond well under normal process temperatures, resulting in a treatment with very poor durability. PTFE typically requires temperatures of at least 300° C. for bonding. Indeed, it is unlikely that such treatment would withstand routine laundering procedures.
Accordingly, there is a clear need for a treatment for activated carbon that is durable with respect to multiple launderings and that is capable of maintaining practical levels of adsorption over time.
SUMMARY
The present disclosure relates to a treatment for activated carbon, and particularly carbon cloth, that is wash-durable and that is present at low add-on levels. The treatment comprises the application of a fluorocarbon compound that dries at temperatures below 300° C., and preferably below 200° C., to form a film. A cross-linking agent can also be employed to improve durability.
DETAILED DESCRIPTION
Disclosures relating to the preparation of carbonized and active carbon yarns and fabrics and the utilization thereof in protective clothing of various types to serve as protection against various hazards may be found in U.S. Pat. No. 3,235,323 to Peters; U.S. Pat. No. 3,256,206 to Doying; U.S. Pat. No. 3,556,712 to Dickson et al.; U.S. Pat. No. 3,639,140 to Miyamichi; U.S. Pat. No. 3,744,534 to Henry et al.; U.S. Pat. No. 3,769,144 to Economy et al.; U.S. Pat. No. 3,850,785 to McQuade et al; and others. The above list is intended to be representative and should not be taken as a complete list of patents relating to carbon fabrics or processes by which they may be produced.
In addition to carbon cloth, powders, particles, granules, spheres, extruded pellets, and fibers can all be enhanced in accordance with the present treatment. Further, the activated carbon can originate from sources including, but not limited to, coconut shells, coal, wood, rayon, peat, polyacrylonitrile, phenol formaldehyde resin, and cross-linked polystyrene resin.
The treatment comprises impregnating or coating the activated carbon with fluorocarbon compounds that effectively modify the surface energy of the carbon material. Suitable fluorocarbons include those that dry to form a water- and oil-repellent film at temperatures below about 300° C. and, more preferably, at temperatures below about 200° C. The fluorocarbon compounds are preferably copolymer resins containing a monomer with a C 4 to C 24 perfluoro-alkyl radical and a non-fluorinated monomer. Examples include copolymers containing perfluorinated C 8 acrylate monomer and alkyl acrylates, and polyurethanes containing C 8 perfluoroalkyl radicals.
The fluorocarbon compounds can be applied to the activated carbon as an emulsion or solution by spraying, immersion, or fluidized bed application, each of which is followed by a drying step. The fluorocarbon compounds are present at add-on weights of 5% or less and, more preferably, 3% or less, where percentages are based on the weight of the activated carbon. Even at add-on levels of as low as 0.1% of the weight of the activated carbon, the fluorocarbon treatment has been found effective. Preferably, the add-on weights are in the range between 0.1% and 5% of the weight of the activated carbon and, more preferably, in the range between 0.1% and 3%. A cross-linking agent, such as a polyisocyanate cross-linking agent, can be incorporated into the mixture to improve the durability thereof.
In one preferred embodiment, the treatment process is conducted in several steps. First, activated carbon is impregnated with a solvent such as water, acetone, or alcohol, so that solvent molecules occupy the internal pores responsible for gas adsorption. Next, a solution or emulsion containing the fluorocarbon compound(s) is brought into contact with the activated carbon by immersion, spraying, or fluidized bed application. The fluorocarbon molecules cling to the surface of the activated carbon, since solvent molecules are blocking the internal pores. Finally, the treated carbon is dried at elevated temperatures to evaporate the solvent from the internal pores of the carbon. Typically, temperatures of about 100° C. to about 400° C. are suitable for this purpose, although temperatures of about 100° C. to about 200° C. are sufficient when water is used as the solvent.
Because the fluorocarbon treatment application is limited to the surface of the activated carbon, the adsorption properties of the activated carbon are not adversely affected. Rather, the internal pores of the activated carbon remain available for adsorption of undesirable components and the repellent finish on the surface of the carbon helps to preserve its adsorption ability.
The activated carbon, treated according to this process, has good durability, whether washed using home or industrial procedures. Even more importantly, the treatment prevents the adverse effects with respect to the durability or level of effectiveness of the activated carbon often seen with exposure of the activated carbon to laundry detergents and additives.
EXAMPLE 1
Product OLC™, coconut-based activated carbon granules, sold by Calgon Carbon Corporation of Pittsburgh, Pa., and having particle sizes of 20 to 50 US Mesh, were used in this Example. The carbon granules were dipped into an emulsion containing 4 grams of a non-PTFE fluorocarbon compound sold by Clariant Corporation of Charlotte, N.C., under the tradename NUVA® CPA, Version 5523, and 96 grams of water. (The resulting emulsion contained about 0.5% by weight of fluorocarbon compound.) NUVA ® CPA fluorocarbon emulsion is believed to be an acrylic copolymer containing a monomer with a perfluorinated alkyl chain.
Fine white foam was observed when the activated carbon granules were immersed into the emulsion, indicating the emulsion was displacing gas from the internal pore structure of the activated carbon. The mixture was poured through a filtration funnel, with some vacuum suction being applied through an aspirator pump. The carbon granules were collected on filter paper.
The treated carbon granules were dried in a lab oven at about 150° C. for 30 minutes. The fluorocarbon add-on level on the carbon granules was calculated to be about 1.21% by weight of the granules.
A comparison of untreated and treated carbon granules was conducted. The untreated granules were easily wet with water and some gas was observed as water displaced the gas in the internal pores of the granules. The treated granules, however, could not be wet with water or by an artificial sweat solution, and no gas evacuation was observed, indicating that the water had not penetrated and rendered ineffective much of the internal pore structure that characterizes the carbon granules.
EXAMPLE 2
An activated carbon cloth made from phenol formaldehyde resin fiber and sold by American Kynol of Pleasantville, N.Y., under the tradename ACC-5092-25 was used in this Example. The carbon in the cloth had a surface area of about 2300 m 2 /g, as measured using the Brunauer-Emmett-Teller (BET) model of physical adsorption, where nitrogen is the adsorptive.
A piece of the carbon cloth was immersed in water. The carbon cloth was then removed from the water and immediately immersed in a fluorocarbon mixture. The fluorocarbon mixture contained 4 grams of NUVA® CPA, Version 5523, a non-PTFE fluorocarbon, and 96 grams of water. No foaming was observed. The carbon cloth was squeezed between nip rolls at a pressure of about 20 p.s.i. to remove excess solution. The treated cloth was then dried in a lab oven at 150° C. for 30 minutes.
The fluorocarbon add-on level on the carbon cloth was about 3.8% of the weight of the fabric. The treated carbon cloth exhibited good water-repellent properties, as evidenced by a test in which water droplets that were applied to the surface of the treated carbon cloth rolled off without wetting the cloth.
EXAMPLE 3
A granular activated carbon, having particle sizes of 20 to 50 US Mesh and sold by Japan Enviro Chemical, Ltd. under the tradename “Wh2c20,” was used in this Example. The activated carbon granules were made from coconut shells.
Activated carbon granules were immersed in water and then removed from the water by filtration. The carbon granules were then immediately immersed in a fluorocarbon mixture. The fluorocarbon mixture contained 4 grams of NUVA® CPA, Version 5523, a non-PTFE fluorocarbon, and 96 grams of water. The fluorocarbon add-on level on the carbon granules was about 0.5% of the weight of the granules. No foaming was observed, when the carbon granules were immersed in the fluorocarbon mixture. After being immersed in the fluorocarbon solution, the carbon granules were filtered to remove excess solution. The treated granules were then dried in a lab oven at 150° C. for 30 minutes.
The water repellency of the treated granules was compared with that of the untreated granules by wetting the granules. The untreated granules readily absorbed the water as it was applied. In contrast, water pooled around the treated granules, until the water depth was such that the treated granules floated on the surface of the water.
Gas Adsorption Evaluation
To evaluate the gas adsorptive properties of the products of Examples 1, 2, and 3, the following test was devised.
0.100 grams of treated granules from Example 1 were placed in a first 250-milliliter glass jar fitted with a gas-tight top with rubber septum.
0.08 grams of treated fabric from Example 2 were placed in a second 250-milliliter glass jar fitted with a gas-tight top with rubber septum.
0.100 grams of treated granules from Example 3 were placed in a third 250-milliliter glass jar fitted with a gas-tight top with rubber septum.
At the bottom of each of the three jars were two layers of paper towel that were completely saturated with an artificial sweat solution. The treated carbon was placed directly on the paper towels. The artificial sweat solution contained 0.8% sodium chloride, 0.1% magnesium sulfate, 0.1% lactic acid, 0.05% potassium sulfite, 0.05% urea, 0.015% glucose, 0.01% sodium sulfate, 0.004% butyric acid, 0.004% calcium chloride, and 98.867% water.
3 microliters of toluene was injected into each sealed jar, whereupon the toluene quickly evaporated into the gas phase.
Approximately 10 minutes after the toluene was injected into each jar, a 1-milliliter sample of gas was taken from each jar. The gas samples were injected into a Perkin Elmer Gas Chromatograph (GC) to measure the toluene concentration in the closed atmosphere of each jar. The peak height of each toluene signal in the GC measurement is representative of the toluene concentration in the jar. Lower peak heights indicate lower amounts of toluene in the environment and higher levels of adsorbence by the activated carbon samples.
Using the same amounts of activated carbon that were untreated, the process was repeated. These are shown as the “Control” values in the table below. The values shown are in arbitrary units.
RELATIVE TOLUENE CONCENTRATION
(as indicated by GC Peak Height)
Example
Control
Treated
1
14,402
6,107
2
15,275
4,918
3
19,459
7,191
The data shows that the fluorocarbon treatment, as described herein, improves the adsorbency of the activated carbon where the adsorbent is artificial sweat. Further, it shows that the treatment is effective on both granules and fabric.
Preparation of Composite made with Treated Carbon
Activated carbon cloth made from phenol formaldehyde resin is particularly well suited for use in a composite structure to create biological and chemical protective suits. To evaluate the present treatment in connection with this anticipated use, the following trial was conducted.
The carbon cloth of Example 2 was used in this trial, both as an untreated cloth and as treated according to the process described in Example 2.
The treated and untreated cloths were each laminated between a tricot knit fabric having a weight of 2.3 oz/yd 2 and a needle-punched nonwoven fabric having a weight of 1.2 oz/yd 2 , using about 20 g/yd 2 of dot-printed copolyamide adhesive pre-applied to the two fabrics. Each layered structure (knit fabric with pre-printed adhesive, treated or untreated carbon cloth, nonwoven fabric with pre-printed adhesive) was fed through a belt laminator at 140° C. for about 30 seconds. The resulting composites were then subjected to evaluation.
It was observed that the fluorocarbon treatment on the activated carbon cloth had no adverse effect on the ability to form a composite structure (that is, the bonding between the carbon cloth and the adhesive layers was not compromised). Additionally, since only the core of the composite was treated to be hydrophobic, the outer fabric layers of the composite remained relatively hydrophilic. The dual nature of the composite structure is believed to provide comfort to users thereof, by allowing good air permeability and moisture wicking.
The gas adsorptive properties of the two composites (containing treated and untreated carbon cloths) were tested according to the following procedure. The gas adsorption test was used to measure the adsorbent properties of the composite.
1. A one-inch square of the composite was enclosed in a 22-milliliter glass vial with a rubber septum stopper. 2. 60 microliters of a blend of a 1:1:3:3 ratio of carbon tetrachloride, dimethyl sulfide, methyl salicylate, and dimethyl methyl phosphonate were injected into the vial. 3. The vial was placed in an oven at 50° C. for one hour. 4. The vial was removed from the oven and allowed to cool to room temperature. 5. A solid phase microextraction (SPME) fiber was then inserted into the vial to sample the gas vapor. 6. An Agilent 6890 Gas Chromatograph (GC) with a 5973 mass selective detector was used to measure the relative concentration of each of the four compounds in the vial's headspace. The peak area of each component's gas chromatograph signal was representative of the relative concentration of each component.
This test was performed before the composite samples were washed and again after each of the composites had been washed 6 times in an industrial laundry machine (with drying after each wash). The washing and drying was performed in accordance with the following test procedure.
Washing/Drying Procedure
The textile composite was washed in a 35-pound Milnor front-load washing machine, with a total load of 30 pounds of textile, using type 2 laundry detergent NSN 7930-00-252-6797 available from Cosco Company of Brooklyn, N.Y.
The following wash cycles were used:
WASHING PROCEDURE
Time
Temperature
Water
Detergent Usage/
Operation
(minutes)
(F)
Level
30 lb. load
Break
6
110
High
85 g
Wash
2
110
High
51 g
Rinse
2
90
High
Rinse
2
90
High
Rinse
2
90
High
Extract
5
n/a
n/a
(low speed)
After each wash, the textile composite was dried in a 50-pound gas dryer for 30 minutes at a “Low Delicates” setting (about 120° F.), followed by a 5-minute cool-down period. The drying step (30-minute cycle, 5-minute cool-down) was repeated after the sixth drying cycle to ensure that the composite was completely dry.
Returning again to the gas adsorption test procedure, the results are shown in the table below, where the values represent the peak area on the gas chromatograph, as measured in arbitrary units. Lower peak heights indicate lower amounts of the chemical compound in the environment and higher levels of adsorbence by the activated carbon samples.
ADSORPTIVE CAPACITY COMPARISON TEST
(as measured in arbitrary units by relative GC peak height)
Untreated
Treated
Chemical
Before
After 6
Before
After 6
Compound
washing
Washes
washing
Washes
Dimethyl sulfide
320.13
541.25
213.67
66.89
Carbon tetrachloride
303.22
1490.93
98.51
32.36
Dimethyl methyl
89.3
1191.14
310.89
77.62
phosphonate
Methyl salicylate
3.23
299.15
102.13
44.28
As can be seen from the test data, the adsorptive capacity of the activated carbon is significantly decreased in the untreated sample, that is, without the presence of a fluorocarbon treatment. This is particularly evident after laundering. For each compound, the treated activated carbon showed better adsorption after laundering than it did initially. Accordingly, this test indicates that, when an adsorbent composite as described herein is treated with a fluorocarbon as described herein, laundering actually improves the adsorption effective of the activated carbon. The opposite trend is observed with the untreated carbon samples. | 4y
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method of and apparatus for removing contaminants, such as particles and organic material, from a semiconductor substrate or a liquid crystal display (LCD) substrate.
[0003] 2. Description of the Related Art
[0004] In the process of manufacturing an integrated circuit (IC), such as a memory device or an LCD, the surface of a substrate of the IC may be contaminated. Contaminants on the surface of a substrate may include organic material, dust, residue, and metal contaminants. Such contaminants may be divided into two types: organic materials that can be removed mainly by a chemical reaction and particles that can be removed mainly by physical force. This contamination typically occurs when the substrate is being stored or is in a stand-by state between successive processes. The contaminants may create defects that ultimately cause the integrated circuits to malfunction. For example, organic residue on the surface of a substrate may cause a defect in a subsequently formed thin film or may increase the contact resistance of the device.
[0005] Thus, a step of cleaning the surface of a substrate, such as a wafer, is attendant to each process performed in the manufacturing of an integrated circuit such as memory device or an LCD. The cleaning is performed to remove organic contaminants or contaminant particles from the surface of the substrate. Conventional wet cleaning techniques have been used for cleaning the surface of a substrate. It is well-known that these wet cleaning techniques are very effective in removing contaminant particles from the surface of a substrate. Furthermore, the wet cleaning techniques include the use of a spin brush during cleaning or an ultrasonic or megasonic cleaner to enhance the cleaning effect.
[0006] Despite the significant efforts directed towards cleaning the surface of a substrate, the effectiveness of conventional wet cleaning techniques is quite limited when the circuit patterns of the memory device or LCD are extremely fine. For example, the use of a spin brush or an ultrasonic cleaner may damage the fine patterns of a memory device or an LCD. Furthermore, although a spin brush or an ultrasonic cleaner in a wet cleaning process may be effective in removing large contaminant particles, they are hardly effective in removing particles on the order of submicrons.
[0007] Furthermore, along with the miniaturization of the patterns, there is a trend in which a gate or a bit line includes metal such as tungsten (W). Many conventional wet cleaning processes would be detrimental to the metal. Therefore, wet cleaning a substrate on which such a gate or bit line has been formed is limited to rinsing the substrate with deionized water or a minimal cleaning using a stripper. In these cases, it becomes increasingly difficult with any reliable degree to effectively prevent a defect from occurring during a fabrication process.
[0008] Recently, a number of new cleaning techniques have been developed for removing contaminants such as particles or organic residue. For example, according to one approach, an aerosol including microscopic frozen particles is sprayed over the surface of a substrate to remove contaminants from the surface of the substrate. U.S. Pat. No. 5,967,156 issued on Oct. 19, 1999 to Peter H. Rose et al., and entitled “Processing A Surface,” describes a such a method.
[0009] More specifically, the patent discloses a method of removing foreign material (for example, particulate contaminants such as dust and metals, and organic material such as photoresist and fingerprints, and residue) from the surface of a substrate by reacting a reactant gas with the foreign material. An aerosol including frozen particles is applied along with a flow of the reactant to the surface of the substrate to aid the reaction of the reactant gas with the foreign material. The surface of the substrate is irradiated with infrared (IR) or ultraviolet (UV) light to heat the substrate, and thereby further aid the reaction of the reactant gas with the foreign material.
[0010] However, the effectiveness of the aerosol in cleaning the surface of the substrate is reduced because both the physical and chemical cleaning processes are performed simultaneously in the same place. More specifically, the ultraviolet or infrared light produced during the chemical cleaning process may reduce the effectiveness of the aerosol because ultraviolet and infrared light are radiant forms of energy. Therefore, the ultraviolet or infrared light is absorbed by the walls of the processing chamber and at the surface of the substrate, in particular, by contaminants on the substrate surface or by the reactant fluid. Furthermore, the ultraviolet or infrared light may also be absorbed by the nozzle from which the aerosol issues. Therefore, the temperature inside the processing chamber may rise so much as to preclude frozen particles from issuing from the nozzle. Even if the frozen particles do issue from the nozzle, there is high possibility that the frozen particles will evaporate before reaching the surface of the substrate. Thus, there are hardly any frozen particles to collide with contaminant particles.
[0011] Accordingly, it is highly desirable to provide a method of and apparatus for effectively removing contaminants, such as organic residues or particles, from the surface of a substrate.
SUMMARY OF THE INVENTION
[0012] An object of the present invention is to solve the above-described problems by providing a method of and apparatus for effectively removing contaminants, including particles and organic material, from the surface of a substrate in the process of fabricating an integrated circuit such as a memory or a liquid crystal display (LCD).
[0013] Cleaning apparatuses of the present invention include means by which particles on the surface of a substrate are removed mainly by physical force using an aerosol comprising frozen particles, and means by which organic contaminants are chemically removed in a separate process by a gaseous reactant and radiation providing activation energy for a chemical reaction between the reactant and organic contaminants on the surface of the substrate. That is, in the present invention, a physical cleaning process using frozen particles is performed independently of a chemical cleaning process using a fluid reactant and light so that the activation energy required by the chemical cleaning process does not reduce the effectiveness of the frozen particles used to carry out the physical cleaning process.
[0014] According to one aspect of the present invention, the cleaning apparatus includes: a transfer chamber, a first cleaning chamber connected to the transfer chamber, a reactant supplier associated with the first cleaning chamber so as to expose the surface of a substrate to a reactant within the first cleaning chamber, a light source also associated with the first cleaning chamber to irradiate the substrate and thereby supply the activation energy required to cause a chemical reaction between the reactant and contaminants on the surface of the substrate, a second cleaning chamber connected to the transfer chamber, and an aerosol generator associated with the second cleaning chamber for jetting an aerosol containing frozen particles onto the surface of the substrate within the second cleaning chamber.
[0015] The light source may be an ultraviolet or infrared lamp that irradiates the substrate within the first cleaning chamber.
[0016] In a specific method according to the present invention executed in conjunction with this apparatus, a substrate is transferred from the transfer chamber to one of the cleaning chambers whereupon one of the cleaning processes is performed therein, then the substrate is transferred to the other cleaning chamber via the transfer chamber whereupon the other cleaning process is performed. Accordingly, the infrared or UV light provided by the light source does not affect the efficacy of the frozen gas particles because the light and the frozen gas particles are provided in separate spaces, i.e., the first and second cleaning chambers.
[0017] The aerosol generator may be a nozzle disposed above the inlet of the second cleaning chamber for jetting the aerosol onto the surface of the substrate as the substrate enters the second cleaning chamber.
[0018] According to another aspect of the present invention, the cleaning apparatus includes: a transfer chamber, a cleaning chamber connected to the transfer chamber, an aerosol-generating nozzle disposed in the cleaning chamber for jetting an aerosol containing frozen particles onto the surface of a substrate transferred into the cleaning chamber, a reactant supplier that exposes the surface of the substrate to a reactant within the cleaning chamber for chemically removing contaminants from the surface of the substrate, and a laser beam generator that directs a laser beam onto the surface of the substrate transferred into the cleaning chamber in order to supply the activation energy required to chemically react the reactant with the contaminants.
[0019] The aerosol-generating nozzle and the laser beam generator are oriented so that the aerosol is directed onto a region of the substrate separate from that onto which the laser beam is directed while the substrate is being transferred through (to or from) the cleaning chamber. Accordingly, the laser beam used for chemically cleaning the substrate does not impinge the frozen particles used for physically cleaning the substrate.
[0020] In a specific method according to the present invention executed in conjunction with this apparatus, a substrate is transferred from the transfer chamber into the cleaning chamber. As the substrate enters the cleaning chamber, the aerosol is jetted onto a leading region of the substrate surface and is physically cleaned (first cleaning process). The leading region then advances under the laser beam, whereby the activation energy is provided at the leading region so that the leading region is chemically cleaned second cleaning process). The substrate is then withdrawn from the cleaning chamber into the transfer chamber, whereby the leading region again is exposed to the aerosol jet (third cleaning process). In this way the entire substrate surface is both physically and chemically cleaned in a separate manner within the same cleaning chamber.
[0021] The cleaning methods thus can effectively remove contaminants, both particles and organic material, from the surface of the substrate during the fabricating of an integrated circuit such as a memory device or an LCD.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] The above objectives and advantages of the present invention will become more apparent by describing in detail preferred embodiments thereof with reference to the attached drawings in which:
[0023] [0023]FIG. 1 is a plan view of a first embodiment of a cleaning apparatus according to the present invention;
[0024] [0024]FIG. 2 is a sectional view of a first cleaning chamber of the cleaning apparatus of FIG. 1;
[0025] [0025]FIG. 3 is a sectional view of a second cleaning chamber of the cleaning apparatus of FIG. 1;
[0026] [0026]FIG. 4 is a perspective view of an aerosol-generating nozzle of the cleaning apparatus of FIG. 1;
[0027] [0027]FIG. 5 is a plan view of a second embodiment of a cleaning apparatus according to the present invention;
[0028] [0028]FIG. 6 is a sectional view of a first cleaning chamber of the cleaning apparatus of FIG. 5; and
[0029] [0029]FIG. 7 is a schematic diagram of a substrate being cleaned by the cleaning apparatus of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention will now be described more fully with reference to the accompanying drawings, in which the preferred embodiments of the present invention are shown. In the drawings, the shapes of elements are exaggerated for clarity. In addition, like reference numerals designate like elements throughout the drawings.
[0031] Referring to FIG. 1, the first embodiment of a cleaning apparatus according to the present invention includes one or more sets of cleaning chambers 200 and 300 connected to a central transfer chamber 100 . The transfer chamber 100 sequentially transports and dispenses substrates 400 to be cleaned to the cleaning chambers 200 and 300 . The substrates 400 may be supplied to or withdrawn from a loader (not shown) connected to the transfer chamber 100 . A robot (not shown) may be provided in the transfer chamber 100 . The substrates 400 are sequentially introduced into the transfer chamber 100 . The robot sequentially transports and loads the substrates 400 into the cleaning chambers 200 and 300 and subsequently withdraws them from the cleaning chambers 200 and 300 into the transfer chamber 100 .
[0032] The cleaning chambers 200 and 300 provide a place in which contaminants on the surface of the substrate 400 are removed to clean the substrate surface. Here, the term “contaminants” collectively refers to all kinds of contaminants that may accumulate on the surface of the substrate 400 as the integrated circuits are being manufactured or as the substrate 400 is being transferred, stored or is standing by during the overall manufacturing process. In the context of the present invention, the contaminants can be thought of as being largely divided into two types: particles that are removable by physical force and organic material that is removable by a chemical reaction. The surface of the substrate 400 is cleaned chiefly by a chemical reaction in the first cleaning chamber 200 , whereas the surface of the substrate 400 is cleaned chiefly by physical force in the second cleaning chamber 300 . In this case, the second cleaning chamber 300 is separate and discrete from the first cleaning chamber 200 .
[0033] Accordingly, the cleaning of the surface of the substrate 400 using a chemical reaction is performed independently of the cleaning using physical force. Thus, the first cleaning chamber 200 may include a reactant supplier 510 and an ultraviolet light source. The second cleaning chamber 300 may include an aerosol generating nozzle 610 .
[0034] More specifically, a reactant capable of forming a volatile byproduct with contaminants, in particular, organic contaminants, is directed onto the surface of the substrate 400 to chemically remove the contaminants from the surface of the substrate 400 . The reactant may comprise oxygen gas or ozone. In addition, the reactant may be directed onto the surface of the substrate 400 as a fluid flow.
[0035] Thus, the reactant supplier 510 in the first cleaning chamber 200 may be a nozzle or a gas port disposed above the surface of the substrate 400 . In this case, the nozzle is preferably oriented such that the orifice thereof faces the surface of the substrate 400 , whereby a jet of the reactant gas issuing from the orifice impinges the surface of the substrate 400 .
[0036] Furthermore, the nozzle may be located in the vicinity of the inlet of the first cleaning chamber 200 connected to the transfer chamber 100 . This advantageously causes by-products of the cleaning reaction to be exhausted through an exhaust port 250 because the exhaust port 250 is disposed opposite the inlet of the first cleaning chamber 200 .
[0037] If oxygen gas is used as the reactant directed onto the surface of the substrate 400 , the oxygen does not readily react with contaminants on the surface of the substrate 400 , in particular, with organic contaminants. Therefore, additional activation energy is required to cause the oxygen gas to react with the organic contaminants. The activation energy may be provided by light, such as ultraviolet or infrared light, directed onto the surface of the substrate 400 .
[0038] For example, ultraviolet light may be generated by a light source ( 700 in FIG. 2) such as an Hg discharge lamp disposed above the first cleaning chamber 200 . The generated ultraviolet light passes through a quartz window 210 , which constitutes the upper wall of the first cleaning chamber 200 or a chamber dome, and onto the substrate 400 in the first cleaning chamber 200 . The ultraviolet light generated by the Hg discharge lamp may have a wavelength of 184.9 nm or 253.7 nm.
[0039] If ultraviolet light having a wavelength of 184.9 nm is directed onto the surface of the substrate 400 in the first cleaning chamber 200 , the ultraviolet light actually may not be capable of decomposing organic contaminants on the surface of the substrate 400 , but may be absorbed by the oxygen gas contained in the fluid flow of reactant jetted onto the surface of the substrate 400 . The oxygen gas absorbs the ultraviolet light and is activated to produce oxygen radicals or is transformed into activated ozone (O 3 ). The oxygen radicals or ozone reacts with the organic contaminants to generate volatile by-products (actually decomposes the organic contaminants), and the generated by-products are exhausted through the exhaust port 250 , whereby the surface of the substrate 400 is cleaned. In this way, the ultraviolet light having a wavelength of 184.9 nm chiefly aids the reaction of the reactant with the organic contaminants.
[0040] Ultraviolet light having a wavelength of 253.7 nm may be absorbed directly by organic contaminants on the surface of the substrate 400 to decompose the organic contaminants into CO 2 and H 2 O.
[0041] When the chemical cleaning step performed in the first cleaning chamber 200 involves the use of ultraviolet light, it is desirable to initially have a predetermined soaking time. Because the ultraviolet or infrared radiation may heat the aluminum or stainless steel walls of the first cleaning chamber 200 , a cooling system for preventing an increase in the temperature of the walls of the first cleaning chamber 200 may be installed along the outer circumference of the walls.
[0042] As described above, the surface of the substrate 400 transferred into the first cleaning chamber 200 may be chemically cleaned by a fluid flow including oxygen gas along with ultraviolet radiation.
[0043] However, even after the surface of the substrate 400 has been cleaned in this way, other types of contaminants, namely particulate material, may remain on the surface of the substrate 400 . Contaminants such as particles need to be removed or cleaned by a physical mechanism.
[0044] To accomplish this, the cleaning apparatus according the present invention includes the second cleaning chamber 300 connected to the first cleaning chamber 200 via the transfer chamber 100 . Hence, the substrate 400 , which has been cleaned in the first cleaning chamber 200 , can be successively transferred by the robot to the second cleaning chamber 300 through the transfer chamber 100 . Thus, recontamination of the substrate surface is minimized. Alternatively, the substrate 400 may be cleaned in the first cleaning chamber 200 after having been cleaned in the second cleaning chamber 300 . That is, after having been cleaned by physical force in the second cleaning chamber 300 , the substrate 400 may be chemically cleaned in the first cleaning chamber 200 .
[0045] As mentioned above, substrate 400 is cleaned in the second cleaning chamber 300 using physical force. As shown in FIGS. 1 and 3, the physical force is generated by jetting an aerosol onto the surface of the substrate 400 . In this case, the aerosol includes particles in the form of agglomerations of frozen gas particles. The frozen particles are projected onto the surface of the substrate 400 by the gaseous portion of the aerosol.
[0046] The frozen particles entrained in the gaseous portion of the aerosol collide with contaminant particles remaining on the surface of the substrate 400 , thereby dislodging the contaminant particles from the surface of the substrate 400 . Although the aerosol jet is ineffective in removing organic material, it exhibits an excellent cleaning effect on those contaminant particles that are difficult to remove using a chemical mechanism.
[0047] The frozen particles are produced by a heat exchanger 800 . Preferably, an inert gas such as Ar is used for producing the aerosol. Some of the argon particles are frozen by the heat exchanger 800 and agglomerate. The frozen agglomerations of particles and the non-frozen gas particles flow into the aerosol generating nozzle 610 . This mixture of frozen and gaseous particles is jetted in the form of an aerosol through orifices 615 of the nozzle 610 . Preferably, the aerosol is jetted onto the surface of the substrate 400 as it is being transferred into the second cleaning chamber 300 . Thus, the aerosol generating nozzle 610 is disposed above an inlet of the second cleaning chamber 300 as shown in FIGS. 1 and 3.
[0048] In this case, even if the aerosol jet would only envelop a limited region of the surface of the substrate 400 , the aerosol can nonetheless be jetted over the entire surface of the substrate 400 by moving the substrate 400 from the transfer chamber 100 into the second cleaning chamber 300 . To this end, the width of the aerosol jet, at the location of the substrate surface, is preferably no less than the maximum width of the substrate 400 . Accordingly, as shown in FIG. 4, the aerosol generating nozzle 610 may include a plurality of nozzle orifices 615 defined in and spaced along a rod-like nozzle body 611 . The length of the nozzle body 611 may be at least the diameter or maximum width of the substrate 400 . The nozzle orifices 615 face the surface of the substrate 400 as the substrate passes below the aerosol generating nozzle 610 , whereupon the aerosol emerging from the orifices 615 impinges the surface of the substrate 400 .
[0049] The frozen argon particles of the aerosol physically impact contaminant particles on the substrate surface. The impact causes the contaminant particles to be coercively removed from the surface of the substrate 400 . The substrate 400 may be passed back and forth below the aerosol generating nozzle 610 several times to ensure that the surface of the substrate 400 is sufficiently cleaned by the aerosol. Floating contaminant particles removed in this way are exhausted through an exhaust port 350 disposed at one end of the second cleaning chamber 300 .
[0050] Meanwhile, before this cleaning process takes place, the second cleaning chamber 300 may be purged by nitrogen gas. The purge gas may be continuously supplied while the cleaning process is being performed. The purge gas may be supplied via a gas port (not shown) provided in the second cleaning chamber 300 . Alternatively, the purge gas may be supplied via a gas port (not shown) provided in the transfer chamber 100 , whereby the purge gas enters the second cleaning chamber 300 via the transfer chamber 100 . The purge gas may also be supplied to the first cleaning chamber 200 .
[0051] The cleaning apparatus according to the first embodiment of the present invention, as described above, comprises separate and discrete places in which the substrate surface is physically cleaned by the aerosol jet and is chemically cleaned by a fluid reactant and radiant energy provided by infrared or ultraviolet light. Accordingly, the effectiveness of the aerosol jet in cleaning the substrate surface is maximized.
[0052] Alternatively, in a second embodiment of a cleaning apparatus according to the present invention, as shown in FIGS. 5 - 7 , the first and second cleaning processes may be performed in the same chamber without reducing the effectiveness of the aerosol jet in cleaning the surface of the substrate. This is made possible by using a laser to provide the activation energy required to execute the chemical cleaning process.
[0053] Referring to FIGS. 5 and 6, the second embodiment of the cleaning apparatus according to the present invention includes one or more cleaning chambers 200 ′ disposed around a transfer chamber 100 . The transfer chamber 100 sequentially transfers the substrates to be cleaned to the cleaning chamber 200 ′. A robot (not shown) may be provided in the transfer chamber 100 to sequentially transfer and load the substrates 400 , which have been sequentially supplied to the transfer chamber 100 , into the cleaning chamber 200 ′ and to collect the cleaned substrates 400 from the cleaning chamber 200 ′.
[0054] The cleaning chamber 200 ′ provides a place in which contaminants on the surface of the substrate 400 are removed. As with the case of the first disclosed embodiment, the term “contaminants” collectively refers to all kinds of contaminants that may accumulate on the surface of the substrate 400 as the integrated circuits are being manufactured or as the substrate 400 is being transferred, stored or is standing by during the overall manufacturing process. However, unlike the first embodiment of the cleaning apparatus according to the present invention, the second embodiment of the cleaning apparatus is configured such that physical and chemical cleaning processes are performed in the same cleaning chamber 200 ′. Nevertheless, the activation energy, required for facilitating the chemical cleaning process, does not prevent the frozen particles of the aerosol from being formed or from cleaning the surface of the substrate.
[0055] More specifically, a reactant supplier 510 (e.g., a nozzle or a gas port) and a laser beam generator may be disposed in the cleaning chamber 200 ′ to chemically remove contaminants from the surface of the substrate 400 . The reactant supplier 510 produces a fluid flow comprising a reactant capable of forming volatile by-products through a chemical reaction with contaminants on the surface of the substrate 400 . The reactant may include oxygen or ozone that are effective in removing organic contaminants.
[0056] The reactant supplier 510 is installed in the cleaning chamber 200 ′ in such a way as to direct the reactant onto the surface of the substrate 400 . Preferably, the reactant supplier 510 comprises a nozzle whose orifice is directed toward the surface of the substrate 400 so that a fluid jet of the reactant issuing from the nozzle impinges the surface of the substrate 400 . Furthermore, the nozzle may be located in the vicinity of the inlet of the cleaning chamber 200 ′, i.e., adjacent the location at which the cleaning chamber 200 ′ is connected to the transfer chamber 100 . This advantageously facilitates the exhausting of the by-products of the cleaning reaction through an exhaust port 250 because the exhaust port 250 is disposed opposite the inlet of the cleaning chamber 200 ′.
[0057] Alternatively, the fluid flow comprising the reactant oxygen gas may be provided in the transfer chamber 100 . That is, a reactant supplier such as a gas port is installed in the transfer chamber 100 . The fluid flow comprising the reactant is directed from the transfer chamber 100 towards the cleaning chamber 200 ′, thereby providing the cleaning chamber 200 ′ with the reactant.
[0058] However, reactant gas, such as oxygen may not readily directly react with contaminants on the surface of the substrate 400 , in particular, organic contaminants. Thus, activation energy is required to cause the oxygen to react with the organic contaminants. The activation energy may be provided by a laser beam that irradiates the surface of the substrate 400 .
[0059] The laser beam may be generated by a laser beam generator including a laser 910 , a lens 950 , and a reflector 930 that reflects the laser beam from laser 910 through the lens 950 . The laser beam is emitted into the cleaning chamber 200 ′ through a quartz window 210 ′ disposed on an upper wall of the cleaning chamber 200 ′. The laser beam is focused by the lens 950 onto a predetermined focal plane, that coincides with the surface of the substrate 400 as the substrate is being transferred into the cleaning chamber 200 ′. The cross section of the laser beam at the focal plane, i.e., at the substrate surface, can be controlled by the lens 950 . In this case, the laser beam has an elongate cross section at the surface of the substrate 400 , as shown in FIG. 5. Therefore, although the laser beam irradiates a limited region, substantially the entire surface of the substrate 400 can be irradiated with the laser beam by moving the substrate 400 across the path of the beam. In this case, the cross section of the laser beam at the surface of the substrate 400 has a length greater than the width of the substrate 400 in one or more directions.
[0060] The energy provided by the laser activates the oxygen gas or ozone to produce oxygen radicals or activated ozone (O 3 ). Also, the laser supplies the activation energy required to react the oxygen radicals or activated ozone with organic contaminants on the substrate surface to generate volatile by-products (actually decomposes the organic contaminants), and the generated by-products are exhausted through the exhaust port 250 , whereby the surface of the substrate 400 is cleaned.
[0061] As was mentioned above, the surface of the substrate 400 is also cleaned in the cleaning chamber 200 ′, using physical force. To this end, an aerosol-generating nozzle 610 may be disposed in the cleaning chamber 200 ′. As in the first embodiment, the aerosol includes agglomerations of frozen gas particles, produced using a heat exchanger 800 . Again, the gas is preferably argon. The aerosol of gaseous argon and frozen particles of argon issue from the orifices 615 of nozzle 610 . The frozen argon particles that reach the surface of the substrate 400 collide With contaminant particles remaining on the surface of the substrate 400 , thereby dislodging the contaminant particles from the surface of the substrate 400 . Floating contaminant particles removed in this way are exhausted through the exhaust port 250 at one end of the cleaning chamber 200 ′.
[0062] The aerosol-generating nozzle 610 is disposed above an inlet of the second cleaning chamber 300 , as shown in FIGS. 5 and 6, to spray the surface of the substrate 400 with the aerosol as the substrate 400 is being transferred into the cleaning chamber 200 ′ or is being withdrawn from the cleaning chamber 200 ′ into the transfer chamber. In this case, even if the aerosol jet has a cross-sectional area corresponding to only a limited region on the surface of the substrate 400 , the aerosol can be jetted over the entire surface of the substrate 400 . Preferably, the width of the cross-sectional area of the aerosol jet is no less than that of the substrate 400 . To this end, the aerosol-generating nozzle 610 may be of the type previously described and shown in FIG. 4.
[0063] Meanwhile, before this cleaning process takes place, the cleaning chamber 200 ′ may be purged by nitrogen gas. The purge gas may be continuously supplied while the cleaning process is being performed. The purge gas may be supplied via a gas port (not shown) provided in the cleaning chamber 200 ′. Alternatively, the purge gas may be supplied via a gas port (not shown) provided in the transfer chamber 100 , whereby the purge gas enters the cleaning chamber 200 ′ via the transfer chamber 100 .
[0064] As is clear from the description above, in the second embodiment of the cleaning apparatus according to the present invention, the laser beam and the aerosol are directed at separate locations within the cleaning chamber 200 ′ and hence, impinge discrete areas of the substrate surface at any given moment, as shown in FIGS. 5 and 6. More specifically, as shown in FIG. 7, the laser beam is emitted onto a region on the substrate surface different from that onto which the aerosol jet is directed. The frozen argon particles 655 of the aerosol jet 600 are not exposed to the laser beam before reaching the surface of the substrate 400 because laser beam is a highly directional or near-zero-divergence beam.
[0065] Thus, the frozen argon particles 655 in the aerosol 600 from evaporating into a gas due to heating by laser beam irradiation before colliding with contaminant particles on the substrate surface. Furthermore, since the aerosol generating nozzle 610 is not actually exposed to the emitting laser beam, the aerosol generating nozzle 610 is not heated by laser beam irradiation. Thus, the formation of an aerosol is not disturbed. Furthermore, since the laser beam is highly directional, the heating of the wall of the cleaning chamber 200 ′ due to the laser beam irradiation or a temperature rise in the cleaning chamber 200 ′ can be prevented.
[0066] Accordingly, physical cleaning by the frozen argon particles 655 contained in the aerosol 600 can be effectively performed in the cleaning chamber 200 ′ as described above through chemical cleaning is also performed therein.
[0067] According to a cleaning method using the cleaning apparatus according to the second embodiment of the present invention, after the substrate 400 is transferred to the transfer chamber 100 , the substrate 400 is transferred from the transfer chamber 100 to the cleaning chamber 200 ′. There, the aerosol is jetted onto the surface of the substrate 400 as the substrate 400 is moved under the aerosol-generating nozzle 610 to thereby clean the surface of the substrate 400 (first cleaning process). Subsequently, the surface of the substrate is exposed to a fluid comprising a reactant and then is irradiated with a laser beam (second cleaning process). Next, the substrate 400 is transferred from the cleaning chamber 200 ′ to the transfer chamber 100 to wherein the aerosol is again jetted onto the surface of the substrate 400 (third cleaning process). As a result, contaminants are effectively removed from the surface of the substrate 400 .
[0068] Finally, although the present invention has been particularly shown and described with references to the preferred embodiments thereof, various changes in form and details may be made thereto without departing from the spirit and scope of the invention as defined by the appended claims. | 4y
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This is a continuation of application Ser. No. 07/899,367, filed Jun. 16, 1992.
FIELD OF THE INVENTION
This invention relates to insect repellents, and in particular to insect repellent formulations having enhanced residual activity.
BACKGROUND OF THE INVENTION
Volatile insect repellents disappear relatively rapidly when applied to the skin. They are also quickly washed away by water, whether fresh or salt containing.
The most prominent insect repellent in use today is N,N′-diethyl toluamide, commonly known as DEET. Other volatile insect repellents are known including ethyl hexanediol; 2-(octylthio)ethanol; dimethyl phthalate; di-n-propyl-2,5-pyridine dicarboxylate; 1,5a,6,9,9a, 9b-hexahydro-4a(4b)-dibenzofuran carboxaldehyde; citronellal; citronellol; geraniol; nerol; and linalool. The formulation of such insect repellents is particularly problematic due to the greasy feel of many of the repellents and especially the effect of DEET in staining clothing, crazing plastics and washing away in humid or rainy weather or when the person using the repellent is participating in water sports such as swimming or fishing. In addition, the lack of retention of insect repellents due to the action of water is also affected by the individual wearer's sweating.
The evaporation of the insect repellent is directly related to the ambient temperature and wind velocity. Approximately 50% of a topically applied dose is absorbed in six hours with peak plasma levels being reached in 1 hour (Lurie et al, Pharmacokinetics of insect repellent N,N-diethyl toluamide. Med. Parazitol., 47, 72, 1979).
Mehr et al, (Laboratory Evaluation of Controlled-Release Insect Repellent Formulations, J. Am. Mosq. Control Assoc., 1,143, 1985) evaluated a number of controlled release formulations of microencapsulated DEET and hydrophilic vinyl polymers such as polyvinylpyrrolidone. The polyvinylpyrrolidone formula was no better than unformulated DEET in repelling mosquitoes.
Reifenrath et al, (Evaporation and Skin penetration characteristics of mosquito repellent formulations. J. Am. Mosq. Control Assoc., 5, 45 1989) tested silicone polymers, acrylate polymers, fatty acids and mixtures of repellents and evaluated evaporation and skin penetration. No differences in evaporation and skin penetration was found between formulations containing the polymers and unformulated DEET or with a mixture of dimethyl phthalate and DEET.
Reifenrath et al, (In vitro skin evaporation and penetration characteristics of mosquito repellents. J. Pharm. Sci. 71, 1014, 1982) showed that the duration of repellent efficacy on man correlated with the time that vapor levels at the surface of the skin exceeded the minimum effective evaporation rates in vitro.
U.S. Pat No. 4,474,081 discloses the use of maleic anhydride/alpha olefin polymers and terpolymers to provide slow release of contact insect repellents when applied to the surface of the skin.
U.S. Pat No. and U.S. Pat. No. 4,774,082 discloses the use of maleic anhydride/alpha olefin polymers and terpolymers to provide slow release of volatile insect repellents when applied to the surface of the skin.
Chemical Abstracts 110, 207847s (1989), discloses mosquito repellent compositions which have an active agent and an oil-soluble, water insoluble acrylate polymer comprising acrylic acid, stearyl methacrylate and isooctyl acrylate.
Ideally, an insect repellent formulation for mammalian use should be non-staining, non-greasy, long lasting, and resistant to washing off from rain, humidity, sweat, fresh waters or ocean waters and reduce penetration of the skin.
SUMMARY OF THE INVENTION
The composition of this invention comprises a copolymer of polyvinyl pyrrolidone and an alkyl group of 4-30 carbons formulated with an insect repellent.
The object of this invention is to provide an insect repellent composition having enhanced residual insect repellent activity comprising: (1) an alkylated polyvinylpyrrolidone; and (2) a volatile insect repellent.
Another object of this invention is to provide an insect repellent composition having enhanced resistance to removal by water, salt water or sweat comprising: (1) an alkylated polyvinylpyrrolidone; and (2) a volatile insect repellent.
Yet another object of this invention is to provide an insect repellent composition having enhanced residual insect repellent activity comprising: (1) an alkylated polyvinylpyrrolidone; (2) a volatile insect repellent and (3) a silicone polymer.
Still another object of the invention is to provide a surface application of an odorant with improved residence time.
Another object of this invention is to provide a matrix containing an odorant which is capable of being sprayed or spread evenly.
Although a great deal of investigation into the cosmetic uses of alkylated polyvinylpyrrolidone copolymers has been carried out, their utility to serve as slow release agents for odorants such as perfumes and insect repellents has not been previously observed.
The compositions of the invention are completely unexpected to give residual activity of insect repellency in light of the previous art. This unexpected characteristic, combined with their known cosmetic appeal of non-greasy and water repellent formulations, provide ideal volatile insect repellent formulations.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Volatile insect repellents which are of value in this invention are those which have the combined characteristics of insect repellency and safety and which can be applied to mammalian skin.
The formulation of this invention contains an alkylated polyvinyl pyrrolidone copolymer and a volatile insect repellent. This formulation is characterized by high residual action, low skin penetration, and high resistance to removal by water. Other volatile materials such as fragrances may be formulated in the compositions of this invention. Such compositions are non-greasy and are easily applied to the skin.
By way of example and not by limitation, insect repellents which are valuable in the invention include: N,N′-diethyl toluamide, commonly known as DEET; ethyl hexanediol; 2-(octylthio)ethanol; dimethyl phthalate; di-n-propyl-2,5-pyridine dicarboxylate; 1,5a,6,9,9a, 9b-hexahydro-4a(4b)-dibenzofuran carboxaldehyde; citronellal; citronellol; geraniol; nerol; and linalool. Other insect repellents recognized in the art, may be used in this invention.
The concentrations of the repellent in the compositions of this invention may be varied, and are limited only by their presence in the composition in such quantities that they will provide effective relief from the targeted insect or insects to be repelled and the concentration of the other ingredients of the formulation.
Thus, the concentration of the insect repellent may be from 1 to 90%, however a range of 1 to 25% is preferred.
Alkylated polyvinylpyrrolidones which may be used include copolymers of polyvinylpyrrolidone and an alpha olefin of chain length of 4 to 30 carbons. Preferred embodiments of this invention are the hexadecene copolymer of polyvinylpyrrolidone (PVP), the eicosene copolymer of PVP and the 1-triacontene copolymer of PVP.
The silicone polymers which are useful in the present invention include dimethicone (Dow Corning 200 Fluids), dimethicone and trimethylsiloxysilicate (Dow Corning 593 Fluid), stearoxy dimethicone (SWS 755 Wax), cyclomethicone (Dow Corning 344 or 345 Fluid, Union Carbide 7158 Fluid, GE SF 1173, 1202 or 1204), polysiloxane (Dow Corning 3225C Fluid), cyclomethicone and dimethicone (Dow Corning X2-1401) and dimethicone (GE SE30, 76 gums, ultrahigh molecular weight dimethicone) and mixtures thereof.
Silicone polymers which are preferred in the invention include polysiloxane (Dow Corning 3225C Fluid) and polydimethylcyclosiloxane (Dow 344 or 345 Fluid).
The silicone polymers may be present in the range of 1 to 60%.
Preservatives which are know in the art to be useful in the present invention include: Quaternium 15 (Dowicil 200), methyl paraben, propyl paraben, dihydroxydimethyl hydantoin, benzyl alcohol, methyl chloroisothiazolinone and methyl isothiazolinone, butyl paraben, imidazolidinyl urea, diazolidinyl urea, disodium ethylenediamine tetraacetic acid and tetrasodium ethylenediamine tetraacetic acid and mixtures thereof. The quantities of such agents used may vary depending on the combination and the levels required to prevent microbial growth.
Oils which are useful in the present invention may be present in the range of up to 50% of the composition of the present invention. A preferred range is up to 30%.
Other ingredients which are known in the art to be useful in the preparation of acceptable cosmetic formulations may also be included in the present invention to provide cosmetically acceptable formulations.
The following examples are given by way of illustration and not of limitation.
EXAMPLE 1
A formula containing low quantities of N,N′-diethyl-m-toluamide (DEET).
The following formula was prepared by heating the water in A to 85° C. with agitation and adding carbomer 940 (a trademark of B.F. Goodrich for acrylic acid, homopolymer). After the carbomer 940 was dissolved, the triethanolamine was added. In a separate container, a mixture, B, of dimethicone, glyceryl stearate SE, PVP/eicosene copolymer (Ganex V-220, a trademark of GAF), DEET and myristyl myristate was heated with stirring until the mixture was uniform. Mixtures A and B were added together with stirring and allowed to cool while continuing the stirring. At around 40° C., the mixture C, consisting of diazolidinyl urea, methylparaben and propylparaben in propylene glycol was added. The whole was cooled to room temperature with continued stirring.
parts
Formula
added
A.
Deionized water
87.3
carbomer 940
0.1
triethanolamine, 98%
0.1
B.
dimethicone
1.0
myristyl myristate
1.0
PVP/eicosene copolymer
2.0
glyceryl stearate SE
3.5
DEET
4.0
C.
Contents below
1.0
diazolidinyl urea
30%
methylparaben
11%
propylparaben
3%
propylene glycol
56%
This material was equal in effectiveness of repelling mosquitoes to a 100% DEET solution at 1 hour.
EXAMPLE 2
A formula containing moderately high quantities of N,N′-diethyl-m-toluamide (DEET)
A mixture of cyclomethicone, cyclomethicone and dimethicone copolyol, DEET and PVP/polyeicosene copolymer were heated with stirring until the mixture was a homogeneous solution. At that time the solution was allowed to cool to room temperature.
Contents
weight
% Concentration
DEET
19.8 g
19.8
PVP/eicosene copolymer
39.6 g
39.6
cyclomethicone
26.4 g
26.4
cyclomethicone and dimethicone copolyol
13.2 g
13.2
fragrance
1.0 g
1.0
Tests for effectiveness of mosquito repellant activity were conducted by using freshly pupated adult mosquitos caged such that a human volunteer's arm could be placed into the cage. Each volunteers arm was treated with a standard 90% DEET/10% alcohol solution and a formulation to be tested. Both materials were applied in approximately 2 inch circles, with both standard and formulation on the same arm. The volunteer's arm was covered in all areas not treated. Mosquito bites in each area were recorded for comparison and a percentage of protection was calculated per time of exposure based on bites recorded on a non-treated area of the volunteer's other arm.
This formula was equal in efficacy to that of the 100% DEET solution.
To qualitatively determine skin penetration, a human volunteer, known to be sensitive to DEET, was blindfolded and comparative solutions were placed on the volar forearm. The volunteer was asked to identify the solution containing DEET, compared to a known DEET solution or a non-DEET solution. The burning sensation was found to be clearly indicative of DEET at a level of 2% or above in the formulation.
This formula was superior in lack of skin penetration as indicated by no reaction in the human volunteer.
EXAMPLE 3
A formula containing high quantities of N,N′-diethyl-m-toluamide (DEET)
A mixture of cyclomethicone, cyclomethicone and dimethicone copolyol, DEET, PVP/polyeicosene copolymer and fragrance were heated with stirring until the mixture was a homogeneous solution. At that time the solution was allowed to cool to room temperature.
Contents
weight
% Concentration
DEET
40.0 g
40.0
PVP/eicosene copolymer
20.0 g
20.0
cyclomethicone
26.7 g
26.7
cyclomethicone and dimethicone copolyol
12.3 g
12.3
fragrance
1.0 g
1.0
Tests for effectiveness of mosquito repellant activity were conducted by using freshly pupated adult mosquitos caged such that a human volunteer's arm could be placed into the cage. Each volunteer's arm was treated with a standard 90% DEET/10% alcohol solution and a formulation to be tested. Both materials were applied in approximately 2 inch circles, with both standard and formulation on the same arm. The volunteer's arm was covered in all areas not treated. Mosquito bites in each area were recorded for comparison and a percentage of protection was calculated per time of exposure based on bites recorded on a non-treated area of the volunteer's other arm.
This formula was equal in efficacy to that of the 100% DEET solution.
To qualitatively determine skin penetration, a human volunteer, known to sensitive to DEET, was blindfolded and comparative solutions were placed on the volar forearm. The volunteer was asked to identify the solution containing DEET, compared to a known DEET solution or a non-DEET solution. The burning sensation was found to be clearly indicative of DEET at a level of 2% or above in the formulation.
This formula was superior in lack of skin penetration as indicated by no reaction in the human volunteer.
EXAMPLE 4
A formula containing medium quantities of DEET.
The following ingredients were placed in a container and heated with stirring to 80° C. and then cooled to room temperature while continuing to stir.
Contents
weight
% Concentration
1% hydroxypropyl cellulose in water
12,000 g
73.3
glycerol
857 g
5.2
DEET
429 g
2.6
Pluronic L-64 (a surfactant made by
242 g
1.5
BASF)
PVP/eicosene copolymer (a product of
857 g
5.2
GAF)
cyclomethicone
1114 g
6.8
cyclomethicone and dimethicone
686 g
4.1
copolyol
paraban solution (10% methyl and
171 g
1.0
propylparabans in propylene glycol)
This formula was equal in efficacy to that of the 100% DEET solution in field conditions.
In the test described in Example 2, this formula was superior in lack of skin penetration as indicated by no reaction in the human volunteer.
EXAMPLE 5
A formula based on polyvinylpyrrolidone/1-triacontene copolymer.
The following ingredients were prepared and agitated with a propeller stirrer. Solution A was prepared and heated to 80° C. and then solution (B) was headed to 80° C. and added to Solution A. The mixture was allowed to cool to 40° C. and Solution C was added and the whole was allowed to cool to room temperature with continued agitation.
grams
added
(A)
Diisopropyl adipate
8.5
DEA-cetyl phosphate
2.0
polyvinylpyrrolidone/1-triacontene copolymer
3.0
dimethicone
1.0
DEET
7.5
(B)
Deionized water
70.0
hydroxyethylcellulose
0.3
(C)
methyl paraban/propyl paraban/
1.0
diazolidinyl urea in propylene glycol (1:1:2:6)
This formula was equal in efficacy to that of the 100% DEET solution in field conditions.
In the test described in Example 2, this formula was superior in lack of skin penetration as indicated by no reaction in the human volunteer.
EXAMPLE 6
A formula based on polyvinylpyrrolidone/hexadecene copolymer.
The following ingredients were prepared and agitated with a propeller stirrer. Solution A was prepared and heated to 80° C. and then solution (B) was headed to 80° C. and added to Solution A. The mixture was allowed to cool to 40° C. and Solution C was added and the whole was allowed to cool to room temperature with continued agitation.
grams
added
(A)
sorbitan oleate
0.4
glyceryl stearate
1.0
polyvinylpyrrolidone/hexadecene copolymer
3.0
cetyl octanoate
6.0
DEA cetyl phosphate
2.0
DEET
7.5
(B)
Deionized water
76.0
Carbopol 940
0.1
Sorbitol
5.0
Cheelox BF-78
0.5
after thorough mixing add
triethanolamine
0.1
(C)
methyl paraban/propyl paraban/
1.0
diazolidinyl urea in propylene glycol
(1:1:2:6)
This formula was equal in efficacy to that of the 100% DEET solution in field conditions.
In the test described in Example 2, this formula was superior in lack of skin penetration as indicated by no reaction in the human volunteer.
EXAMPLE 7
Aerosol formulations and ratios of insect repellent to polymer.
A mixture of DEET, PVP/eicosene copolymer and chloroform was prepared as shown in the table below. Absorbent paper sticks were dipped in the solution and placed in an oven at 36° C. with a light flow of air. The weights of material absorbed were determined by weighing the total quantity of solution before and after dipping the paper stick in the solution. The paper sticks were checked periodically for the presence of DEET odor. The results obtained are shown in the table.
PVP/
chloro-
repellent/
quantity of
time to no
DEET
eicosene
form
polymer
DEET applied
detectable
(g)
(g)
(g)
ratio
(g)
odor (hr)
5
0
0
100%
.15
30.5
DEET
5
.5
92
10:1
.005
18
5
5
84
1:1
.005
18
2.5
5
92
.5:1
.0025
18
1.25
5
92
.25:1
.0013
30.5
This shows that the presence of the polymer in the formulation retards the evaporation of the DEET. A formulation containing polymer and 0.0013 g of DEET retained its activity as long as a formulation which contained 0.15 g of DEET but no polymer.
EXAMPLE 8
A formula based on PVP/eicosene.
The following ingredients were prepared and agitated with a propeller stirrer. Solution A was prepared and heated to 80° C. and the mixture was allowed to cool to 40° C. and Solution B was added and the whole was allowed to cool to room temperature with continued agitation.
grams
percent
added
concentration
(A)
DC 345
7.4
6.57
polyvinylpyrrolidone/eicosene copolymer
5.7
5.06
DC 3225C
4.6
4.09
DEET
10.0
8.88
(B)
Deionized water
80.0
71.05
Carbopol 940
0.8
.71
Pluracare L-64
2.9
2.58
after thorough mixing add
triethanolamine
0.1
0.09
(C)
methyl paraban/propyl paraban/
1.1
0.97
diazolidinyl urea in propylene glycol
(1:1:2:6)
EDTA
.088
0.08
This formula was equal in efficacy to that of the 100% DEET solution in field conditions.
In the test described in Example 2, this formula was superior in lack of skin penetration as indicated by no reaction in the human volunteer.
Since the above disclosure is subject to variations, it should be understood that the above examples are merely illustrative and that the invention disclosed herein should be limited only by the claims. | 4y
|
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional application No. 60/099,606, filed Sep. 9, 1998.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the field of material mixing methods and apparatus, and more particularly to a dynamic delivery line mixing method and apparatus for actively agitating a feedstock while the feedstock is being passed to a discharge device through a delivery conduit.
While the present invention is subject to a wide range of mixing applications, it is particularly well suited for suspending solids in liquids within the delivery lines of various spray systems, such as sophisticated spray paint systems and coating systems designed for either manual or robotic operation.
2. Technical Background
The vast majority of spray application, fluid processing, and other feedstock delivery systems incorporate one or more fluid delivery conduits through which a feedstock, in liquid, gaseous, or solid form, to include combinations thereof, travels en route to an applicator or other delivery device, such as a spray nozzle, or burner assembly. A common shortcoming associated with such systems is the formation of blockages, either partial or complete, in the delivery conduit. In the case of feedstocks that include solids suspended in a liquid, a contributing factor to these blockages is the separation of the solids from the liquid suspension.
For spray systems such as spray painting systems and spray coating systems used for applying specialty paints and coatings to machines and devices manufactured for specialized government entities such as, but not limited to, the Department of Defense and NASA, this shortcoming is particularly problematic. Typically, the paints and coatings used in such applications are considered highly loaded, in that heavy solids such as metals are suspended in a liquid feedstock to form the paint or coating prior to entering the delivery conduit. Due to the weight of such metals and other solid materials, separation or settling of the solid from the liquid within standard delivery conduits is a common occurrence. The rate at which such solids settle out of suspension depends upon such factors as the rate of delivery of the feedstock to the application device, the weight of the metals, the amount of time the feedstock remains stationary within the line between applications, the length of the delivery conduit, and the number of bends or turns encountered by the feedstock as it passes through the delivery conduit. The slower the delivery, the heavier the metal, the longer the application process is idle, the longer the length of the conduit, and the greater the number and magnitude of the bends, the greater the rate of settling. Even when the feedstock is moving through the conduit, it is essentially moving in one direction, thus, in standard delivery conduits vertical components of force counteracting the force of gravity on these metals are essentially non-existent. Accordingly, even if the feedstock is rapidly forced through the delivery conduit, a significant quantity of solids will settle to the bottom of the conduit over time.
Such setting, over time, results in significant blockages within the delivery conduit, which in turn reduce the efficiency of the spray system being employed. Additionally, many of today's sophisticated computer controlled spray systems are designed to apply paints or coatings at precise rates. When a partial blockage in the delivery line occurs, the systems typically compensate for the reduced flow rate due to the decreased diameter of the conduit by increasing the flow, typically by increasing pressure. Providing this increased flow requires the drive mechanisms to work in excess of their normal operating parameters which often results in undue wear and tear on the drive mechanism, and in certain instances, unexpected failure of the drive mechanism. Moreover, as portions of any such blockages break away from the walls of the delivery conduit, they often become lodged in the reduced diameter orifices of the spray nozzles or jets of the sprayers themselves. The blockages occurring due to the use of standard delivery conduits thus necessitate frequent cleaning of the spray systems which in turn results in increased system down time and business interruption.
In addition, many of the metals and solids delivered in suspension for Department of Defense projects are highly specialized and proprietary in nature. Accordingly, these solids often cost $500.00 or more per quart. Together, the economic loss resulting from frequent cleaning of the delivery systems and significant loss of the solids resulting from cleaning operations often result in lost profits to the system owners, or increased costs to the customers, or both.
In an attempt to overcome these and other shortcomings, systems users have generally taken one of two approaches. One approach is the incorporation of a recirculation pump with present systems. Typically, the recirculation pump is connected to the standard delivery conduit at one or more low points or turns in the delivery line. As solids collect in these low points or turns in the delivery conduit, the recirculation pump is selectively engaged to drain the solids from the delivery conduit and recirculate them back to the supply vessel or pressure pots used to suspend the solids and the liquids prior to the suspension being delivered into the delivery conduit. Such storage vessels or pressure pots typically incorporate a paddle or other mixing device which continuously moves within the vessel to uniformly mix the feedstock. In theory, the solid material returned to the storage vessel via the recirculation pump should maintain the system at equilibrium. However, equilibrium is rarely obtained as the recirculation pump itself becomes a collection site for solid deposits. In addition, the pump components suffer undue wear and tear due to continuous contact with the heavy solid and thus require frequent repair and replacement parts. Moreover, such recirculation systems are often cost prohibitive for the benefits they provide.
The second way systems users have attempted to mitigate against delivery conduit blockages is through the use of static mixers (also known as motionless mixers to those skilled in the art). Static mixers are typically positioned immediately before the delivery conduit or partially within the end of the delivery conduit remote from the application device. Such mixers are typically rigid structures having a plurality of angled surfaces, and are designed to break up the flow of the feedstock as it enters the delivery conduit. As a result of being static, however, the plurality of surfaces of these static mixers themselves become prime collection points for the heavy solids. As a result, the static mixers themselves often promote blockage of the delivery conduits.
In view of the foregoing, there is a need for an apparatus and method for mixing one or more feedstocks within the delivery conduit of feedstock delivery systems such as sophisticated spray paint and coating systems. In addition, there is a need for an apparatus and method that maintains a majority of heavy solids in suspension within the feedstock while the feedstock is passed through the delivery conduits of spray systems and the like. Such a device should be simple to use, inexpensive to manufacture and maintain, and substantially impervious to the substances to which it will be exposed within the delivery conduit. It is to the provision of such a device and method that the present invention is primarily directed.
SUMMARY OF INVENTION
One aspect of the present invention relates to an apparatus for mixing a feedstock. The apparatus includes an elongated conduit through which the feedstock passes, and an agitator positioned within the conduit to communicate with the feedstock. A drive mechanism communicates with the agitator to move the agitator with respect to the conduit, thereby mixing the feedstock.
The present invention is also directed to a method of mixing a feedstock during delivery of the feedstock from a supply vessel to a discharge device. The method includes the steps of urging the feedstock into a hollow elongated conduit coupled at one of its ends to a discharge device and communicating at the other of its ends with a drive mechanism. An agitator housed within the conduit is attached to the drive mechanism. The feedstock is passed through the conduit and around the agitator and one of the agitator or the conduit is moved with respect to the other to mix the feedstock as the feedstock progresses towards the discharge device.
In another aspect, the present invention relates to a system for in-line mixing of a feedstock during delivery of the feedstock to a target. The system includes a supply vessel constructed an arranged to prepare the feedstock a conduit connected to the supply vessel to receive the feedstock, and an agitator positioned within the conduit. A drive mechanism is coupled to at least one of the conduits or the agitator to move one with respect to the other, thereby imparting motion to the feedstock. A discharge apparatus is coupled to the conduit for delivering the feedstock to the target, and a controller is at least connected to the supply vessel and the drive mechanism for receiving inputs and delivering outputs to control the delivery and mixing of the feedstock.
The system, apparatus, and method of the present invention result in a number of advantages over other systems, apparatus, and methods known in the art. For example, the apparatus of the present invention enables delivery systems to effectively and efficiently deliver highly loaded, high performance coating materials designed for demanding defense and space applications, to include many new experimental coating materials. The metals and solids that would otherwise fall out of suspension during delivery of such coatings through the delivery conduits of the systems can now be maintained in suspension. Because the apparatus of the present invention is dynamic in nature, i.e. it actively agitates or mixes these coating materials within the delivery conduit of the delivery systems, the metals and/or other solids are maintained in suspension. Moreover, because the present invention can be adapted for use with any size conduit, the conduit length of such systems is no longer a limiting factor in system design. In addition, because the apparatus of the present invention can agitate these coating materials within the delivery conduit even while the delivery system is idle, blockages within the delivery conduits due to settling can be significantly reduced.
In addition, the method and apparatus of the present invention can be employed to mix more than one feedstock as the feedstocks enter a common conduit from multiple supply locations. The plurality of feedstocks can be a plurality of liquid feedstocks, a liquid and solid feedstock, a liquid and gaseous feedstock, or combinations thereof. Thus, feedstocks that are suspension so such as specialty coatings and paints that are generally susceptible to settling, can now be delivered separately and combined where continuous agitation occurs. As a result, clogging of the delivery systems upstream of the delivery conduit can also be significantly reduced.
Additionally, the present invention provides for flexibility of application and superior transfer efficiency. Because clogging or blockage of the delivery conduit of the present invention is drastically reduced and often eliminated, the apparatus and method of the present invention provides repeatability without frequent cleaning and maintenance, the least amount of waste, and therefore superior cost efficiency for both the user and the customer.
Additional features and advantages of the invention will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the invention as described herein.
It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the invention, and are intended to provide an overview or framework for understanding the nature and character of the invention as it is claimed. The accompanying drawings are included to provide a further understanding of the invention, illustrate various embodiments of the invention, and together with the description serve to explain the principals and operation of the invention.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a plan view of the apparatus of the present invention depicting details of the coupling assembly in phantom lines.
FIG. 2 is an exploded plan view of the apparatus of the present invention.
FIG. 3 is a side elevational view of a preferred agitator of the present invention.
FIG. 4 is a cross-sectional view of the preferred agitator taken through line 4 — 4 of FIG. 3 .
FIG. 5 is a schematic view of a first preferred embodiment of the system of the present invention.
FIG. 6 is a cross-sectional view of the delivery conduit taken through line 6 — 6 of FIG. 5 depicting the agitator housed therein.
FIG. 7 is a schematic view of a second preferred embodiment of the system of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference will now be made in detail to the present preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawing figures to refer to the same or like parts. An exemplary embodiment of the in-line agitator of the present invention is shown in FIG. 1 and is designated generally throughout by reference numeral 10 .
In accordance with the invention, the present invention for in-line agitation of feedstocks includes a drive assembly 12 , coupling assembly 14 , and agitator 18 . Agitator assembly 10 is generally connected to a delivery conduit 16 , such as, a hollow hose, tube, braided cable, or the like. Agitator 18 is preferably received within delivery conduit 16 and is coupled to drive assembly 12 via coupling assembly 14 . Agitator 18 preferably extends along the length of delivery conduit 16 and is moved by drive assembly 12 to agitate feedstocks being passed through the delivery conduit 16 .
Agitator assembly 10 can be more easily described with reference to the exploded view depicted in FIG. 2 . In a preferred embodiment, drive assembly 12 includes a motor 20 such as, but not limited to, an air motor Model No. 1UP-NRV-11, manufactured by Gast Manufacturing Corp, Benton Harbor, Mich., and a reduction drive or gear assembly 28 , such as but not limited to Model No. GR-11, also manufactured by Gast Manufacturing Corp. It will be understood by those skilled in the art that other motors, such as electric motors and hydraulic motors, to name a few, can be used in lieu of pneumatic motors such as motor 20 , and that a wide variety of gear assemblies are operative with the present invention. An air inlet fitting 22 having an air adjustment valve 24 associated therewith for controlling air flow to motor 20 , and an optional muffler 26 are preferably connected to motor 20 . Motor 20 and gear assembly 28 are typically connected with fasteners such as set screws 50 .
Coupling assembly 14 can be configured in a number of ways and preferably includes a housing or sleeve 34 for receiving a first coupling 36 , a coupling insert 38 , a second coupling 40 , a drive shaft 42 , a crushnut 44 , a bushing 46 , packing rings 48 , a packing spacer 52 , and a T-adapter 54 . Coupling assembly 14 is preferably mated to gear assembly 28 with a spacing plate 30 positioned therebetween using fasteners, such as screws 32 threadably received through sleeve 34 . Drive shaft 42 is coupled to gear assembly 28 at one end, and to agitator 18 within T-adapter 54 with fasteners such as set screws 51 . Those skilled in the art will recognize that the remainder of the above-mentioned components of coupling assembly 14 are connected with fasteners such as set screws 53 and the like. Packing rings 48 slidable received onto drive shaft 42 , together with crushnut 44 , bushing 46 , and packing spacer 52 form a seal within coupling assembly 14 when coupling assembly 14 is assembled as shown in FIG. 1 . As will be described in greater detail below, the seal prevents feedstocks from entering the sleeved portion of coupling assembly 14 during operation of the delivery system.
As shown in FIG. 3, the preferred agitator 18 is preferably an elongated flexible cord or line constructed of nylon or some other material compatible with the chemicals, cleaners, and other feedstocks typically used in spray applications. The preferred agitator 18 is a multi-sided structure as shown clearly in the cross-sectional view of FIG. 4 . The multiple sides provide increased surface area, and thus increased agitation and turbulence when agitator 18 is moved within conduit 16 . It will be understood by those skilled in the art, however, that agitator 18 can be formed to take on any number of shapes, including, but not limited to, a tubular member having either a singular radial dimension or a plurality of radial dimensions. Moreover, agitator 18 can also include a plurality of agitating devices positioned within delivery conduit 16 .
In a more complex embodiment of the present invention, one or more agitators 18 can be positioned within delivery conduit 16 , and delivery conduit 16 can be moved with respect to the one or more agitators 18 positioned therein. In such an embodiment, the one or more agitators 18 can be in a fixed position with respect to delivery conduit 16 , or the one or more agitators can also be moved with respect to delivery conduit 16 as delivery conduit 16 is itself moved. In such an embodiment, the motion of the one or more agitators 18 is preferably in a direction opposite the direction of motion of delivery conduit 16 .
Like agitator 18 , delivery conduit 16 is preferably manufactured from a material that is substantially impervious to the chemicals, compounds, and/or solutions that form the feedstocks carried by delivery conduit 16 . In a preferred embodiment, delivery conduit 16 is a hollow Teflon® tube. Those skilled in the art will recognize, however, that delivery conduit 16 can also be a braided cable made from a non-corrosive metal, a flexible nylon hose, or the like.
A first preferred embodiment of the method of the present invention is shown schematically in FIG. 5 . In-line agitator assembly 10 is connected to a control unit 56 , such as a computer, an air supply system 58 , and a feedstock supply reservoir 60 . In the preferred embodiment of the method of the present invention, feedstock supply reservoir 60 houses a feedstock 62 , and includes a mixing device 64 , such as a paddle, and a riser 66 for delivering feedstock 62 to agitator assembly 10 . Feedstock 62 is transported through riser 66 and into delivery conduit 16 where agitator 18 is rotated by in-line agitator assembly 10 . As feedstock 62 passes through delivery conduit 16 en route to a discharge device 68 , agitator 18 is moved with respect to deliver conduit 16 to mix feedstock 62 passing therethrough. Generally speaking, feedstock 62 is pre-mixed within feedstock supply reservoir 60 by rotation of mixing device 64 as indicated by directional arrow 70 . Accordingly, agitator 18 further mixes feedstock 62 after feedstock 62 leaves feedstock supply reservoir 60 .
In a first preferred system for in-line mixing of a feedstock during delivery of the feedstock to a target, such as specialized spray coating and spray painting systems, control unit 56 is connected to in-line agitator assembly 10 , air supply system 58 , feedstock supply reservoir 60 , and discharge device 68 via cable 72 . Control until 56 sends and receives signals from agitator assembly 10 , air supply system 58 , and feedstock supply reservoir 60 , and discharge device 68 to control the mixing rate, flow rate, composition, and discharge rate of feedstock 62 . Feedstock 62 , such as highly loaded coating materials are continuously mixed within the delivery conduit 16 by agitator 18 so that the required composition of coating material 69 is discharged from discharge device 68 onto the target (not shown).
As shown more clearly in FIG. 6, agitator 18 is moved through feedstock 62 as indicated by directional arrow 74 within conduit 18 . Due, at least in part, to the torque applied to one end of agitator 18 by agitator assembly 10 , agitator 18 generally moves in a helical path within delivery conduit 16 . As a result, agitator 18 typically contacts inner walls 72 of delivery conduit 16 , thereby dislodging any sediment that may otherwise build-up along inner wall 72 of delivery conduit 16 . Solids such as metals are thereby maintained in suspension within feedstock 62 as feedstock 62 enters discharge device 68 .
A second embodiment of a system for in-line mixing of feedstocks during delivery of the feedstock to a target is illustrated in FIG. 7 . In-line agitator assembly 10 is connected to an air supply system 58 , a first supply reservoir 76 , and a second supply reservoir 78 . Interposed between each supply reservoir 76 and 78 is a metering device 80 and regulator 82 . A control unit 56 is preferably connected to each of the above-described components of the system via cables to send and receive data to control such parameters as flow, pressure, rate, and composition.
In the second preferred embodiment of the system of the present invention, first supply reservoir 76 preferably contains a catalyst 84 , and second supply reservoir 78 preferably contains a resin 86 . Catalyst 84 and resin 86 can optionally be mixed within their respective reservoirs by mixing elements 88 , and 90 , respectively.
For specialty coating applications, catalyst 84 and resin 86 are delivered through metering devices 80 and regulators 82 in the desired quantities to an adapter 92 which merges the paths of resin 84 and catalyst 86 into delivery conduit 16 . Catalyst 84 and resin 86 are mixed within delivery conduit 16 by agitator 18 to suspend resin 86 within catalyst 84 so that the desired composition of coating material 94 is delivered from discharge device 68 . This embodiment of the system of the present invention is particularly well suited for feedstocks that are highly unstable in suspension as the system maintains the feedstock (catalyst 84 and resin 86 ) in separate flow paths until the feedstocks reach delivery conduit 16 . In this way, clogging of system components is significantly reduced, as is the loss of materials due to suspension losses.
EXAMPLE
The invention will be further described by the following example which is intended to be exemplary of the invention.
Example 1
Acomparison was made between the first preferred embodiment of the coating system of the present invention as described above with reference to FIG. 5, and a control coating system. The control coating system was an identical coating system absent the operation of the in-line agitator. The comparison included two runs, and in both runs, the discharge end of the 28 foot delivery conduit was elevated to approximately 6 feet above floor level, while the opposite end of the delivery conduit was maintained at about floor level. As a result, the solid material within the feedstock naturally gravitated toward the floor within the delivery conduit, thus making it more difficult to prevent settling in the first run.
A well mixed feedstock suspension was maintained in a constantly agitated supply reservoir or pressure pot. The feedstock contained a solid known to quickly settle out of the suspension prior if to delivery from the spray gun. More specifically, the feedstock contained a specialty Infra-red (I.R.) Coating that included a plurality of heavy metal flakes in a low viscosity polyurethane paint having poor homogeneity. As a first step, a 200 cc sample of feedstock was removed from the pressure pot and found to weigh 250.6 grams. The feedstock was then delivered into a 28 foot Teflon® delivery conduit having a 0.25 inch Inner Diameter (I.D.), and was continuously agitated within the elongated agitator for a period of 15 minutes. After 15 minutes of mixing within the conduit, a 200 cc sample of feedstock was removed from the conduit. The measured weight of this 200 cc sample was approximately 246.4 grams indicating that approximately 4.2 grams of solid material had settled out of the suspension within the delivery conduit during mixing.
The delivery conduit of the coating system was then drained and flushed for the second run of the experiment. Following drainage and flushing, the well mixed feedstock from the pressure pot was delivered into the delivery conduit of the spraying system for the control run. Following 15 minutes without agitation within the delivery conduit, a 200 cc sample of feedstock was removed from the delivery conduit. The weight of this sample was approximately 204.3 grams. Accordingly, approximately 46 grams of solid material was lost from the suspension during the control run.
It will be apparent to those skilled in the art that various modifications and variations can be made to the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents. | 4y
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a process for producing a nano-device by providing potential singular points on a substrate, capturing various molecules in the singular points and controlling the conformation of the various molecules with the singular points and a process for producing a nano-device by controlling a chemical reaction using the sequencing with singular points process method, etc.
[0003] 2. Description of the Related Art
[0004] Molecular devices having functions at nanoscale have been vigorously studied. Such nano-devices are expected not only to be the next generation of silicon devices, but also devices for various functions. The development of new materials and technical developments which have been conventionally considered impractical or impossible can be realized by nano material and its processing technology by controlling an atom and a molecule at nano level and making the most use of the properties of a substance thereby. It is expected that in the future molecular devices having functions at nanoscale will be applied not only to materials and devices, but also to other fields such as optics, electronics, medicine, bio, environment and energy. Trials for controlling molecular sequence have been recently carried out utilizing the self-organization of molecules of porphyrin compounds on a metal surface for procuring the development of a molecular device.
[0005] For example, it is known that 5,10,15,20-tetrakis-(3,5-ditertiary-butylphenyl)porphyrin (H 2 -TBPP) is regularly aggregated on a gold (111) surface (refer to the non-patent literature 1: Barth et. al., Phys. Rev. B42, 9307-9318 (1990)).
[0006] Thus, tetrakis-(3,5-ditertiary-butylphenyl)porphyrin derivatives are actively studied as the initiator of a molecular device (refer to the non-patent literature 2: T. Yokoyama, S. Yokoyama, T. Kamikado and S. Mashiko, J. Chem. Phys. 115 (2001) 3814), and the non-patent literature 3: T. A. Tung, R. R. Schlittler and J. K. Gimzewski, Nature 386 (1997) 696).
[0007] Further, it is known that the four legs of a porphyrin derivative are convertible to various kinds of functional groups for adjusting the strength of interaction with a substrate (refer to the non-patent literature 4: T. Kamikado, S. Yokoyama, T. Yokoyama, Y. Okuno and S. Mashiko, Abstract of the 5 th International Conference on Nano-molecular Electronics (ICNME 2002) 175).
[0008] Furthermore, there is known a method by which the dipole moment of a molecule is controlled by introducing a different functional group to one or two of the four legs of a porphyrin derivative, thereby controlling the reaction direction (refer to the non-patent literature 5: T. Yokoyama, S. Yokoyama, T. Kamikado, Y. Okuno and S. Mashiko, Selective assembly on a surface of supramolecular aggregates with controlled size and shape, Nature, Vol. 413 pp 619-621 (2001)).
[0009] However, with respect to the above technologies, there has been a problem that it is not always clear from what site on a substrate a reaction preceeds.
SUMMARY OF THE INVENTION
[0010] It is one object of the present invention to provide a process for producing a bottom-up type nano-device wherein a reaction is initiated from potential singular points on a substrate.
[0011] It is another object of the present invention to provide a process for producing a nano-device wherein compound molecules are arranged with regularity and a chain reaction is accelerated utilizing the sequence pattern.
[0012] It is another object of the present invention to provide a process for producing a nano-device wherein a plural number of compound molecules are arranged with regularity, the distance between the compound molecules is controlled and a chemical reaction between the compound molecules is controlled.
[0013] It is another object of the present invention to provide a process for producing a nano-device wherein the conformation of a molecular device can be easily controlled.
[0014] In order to solve at least one of the above-mentioned problems, the present invention provides a process for producing a nano-device comprising a step of producing potential singular points that involves placing the potential singular points on a substrate and a contact step of contacting a compound having a functional group which interacts with the fore-mentioned potential singular points on said substrate. Thus, a bottom-up type process for producing a molecular device in a site where molecules can be grown and their positional relation and the like are controlled is achieved by first providing the potential singular points on a substrate.
[0015] The present invention controls the conformation of a molecule which constitutes the nano-device by controlling the position of the potential singular points on a substrate, in the fore-mentioned step of producing potential singular points.
[0016] The present invention controls the conformation of a molecule which constitutes the nano-device by controlling the position of the fore-mentioned potential singular points on a substrate and further controls a reaction between compounds which constitute the nano-device, in the fore-mentioned step of producing potential singular points.
[0017] The present invention may further comprise a compound-bonding step of bonding compounds to each other via the fore-mentioned potential singular points.
[0018] The present invention may further comprise a step of bonding a compound combined with the substrate via the fore-mentioned potential singular points to another compound that is bonded (connected) to said compound, after the fore-mentioned contact step.
[0019] The present invention relates more preferably to the fore-mentioned potential singular points being recesses placed in the substrate wherein the depth of each recess is 1 to 50 angstroms, and is formed by using an electron beam, a convergent atomic beam, a convergent ion beam and nano-lithography.
[0020] The present invention relates more preferably to the compound having a functional group which interacts with the fore-mentioned potential singular points being a porphyrin compound represented by the following General Formula (I).
(wherein M represents either two hydrogen atoms, a divalent metal, a trivalent metal derivative, or a tetravalent metal derivative; R′ represents either a C 2-12 alkenyl group, a C 2-12 alkenyloxy group, a C 3-6 dienyl group, a C 2-12 alkynyl group, a C 2-12 alkynyloxy group, a hydroxyl group, a C 1-12 alkoxy group, a C 1-12 acyl group, a C 1-30 acyloxy group, a carboxyl group, a C 1-12 alkoxycarbonyl group, a carbamoyl group, a C 1-12 alkylcarbamoyl group, an amino group, a C 1-12 alkylamino group, an arylamino group, a cyano group, an isocyano group, a C 1-12 acylamino group, a nitroso group, a nitro group, a mercapto group, a C 1-12 alkylthio group, a sulfo group, a sulfino group, a C 1-12 alkylsulfonyl group, a thiocyanate group, an isothiocyanate group, a thiocarbonyl group, a sulfamoyl group, a C 1-12 alkylsulfamoyl group, a hydroxyiminomethyl group (—CH═NOH), a C 1-12 alkoxyiminomethyl group, a C 1-12 alkenyloxyiminomethyl group, a C 1-12 alkynyloxyiminomethyl group, a C 1-12 alkyliminomethyl group, a C 1-12 alkylsulfamoyliminomethyl group, a thiocarboxyl group, a hydroxyaminocarbonyl group, an alkoxyaminocarbonyl group, or halogen; X represents either a C 1-12 alkyl group, a C 1-12 alkoxy group, a trialkylsilyloxy group, a phenyldialkylsilyloxy group, or a alkyldiphenylsilyloxy group; Y represents either a hydrogen atom, a hydroxy group, a C 1-30 alkoxy group, a C 2-30 alkenyloxy group, a C 2-30 alkynyloxy group, or a C 1-30 acyloxy group; and each of R 5 to R 12 represents independently a hydrogen atom, a halogen atom, an amino group, a hydroxy group, a nitro group, a cyano group, or a C 1-3 alkyl group which may optionally have a substituent.)
[0026] In General Formula (I), X is preferably a tertiary-butyl group.
[0027] In General Formula (I), M is preferably two hydrogen atoms, and R′ is either a C 1-12 alkylthio group, a cyano group, a hydroxyl group, a carboxyl group, an amino group, a formyl group, a carbamoyl group, a nitro group, a hydroxyiminomethyl group (—CH═NOH), an ethynyl group, a hydroxyaminocarbonyl group, or a sulfamoyl group.
[0028] In General Formula (I), R′ is more preferably a methylthio group.
[0029] In the present invention, the compound having a functional group interacting with the fore-mentioned potential singular points is more preferably 5-(4-methylthiophenyl)-10,15,20-tris-(3,5-ditertiary-butylphenyl)porphyrin (“MSTBPP”).
[0030] The present invention can provide a process for producing a bottom-up type nano-device by placing potential singular points at specific points on a substrate and initiating a reaction from the potential singular points.
[0031] The present invention can provide a process for producing a nano-device wherein compound molecules are arranged with regularity by placing potential singular points at specific points on a substrate and initiating a reaction from the potential singular points and a chain reaction is accelerated utilizing the sequence pattern created by the singular points arrangement.
[0032] The present invention can provide a process for producing a nano-device wherein a plural number of compound molecules are arranged with regularity by placing potential singular points at specific points on a substrate and initiating a reaction from the potential singular points, so that the distance between the compound molecules is controlled and hence a chemical reaction between the compound molecules is controlled.
[0033] The present invention can provide a process for producing a nano-device wherein the conformation of a molecular device can be easily controlled by placing potential singular points at specific points on a substrate and initiating a reaction from the potential singular points.
BRIEF DESCRIPTION OF THE DRAWINGS
[0034] FIG. 1 is a figure showing a first embodiment of the present invention. FIG. 1 (A) is a view illustrating a substrate and a compound. FIG. 1 (B) is a view illustrating an aspect in which the substrate is interacted with the compound when the potential singular points are nearly linear. FIG. 1 (C) is a view showing an aspect in which the substrate is interacted with the compound when the potential singular points are provided at points of nearly equal intervals. FIG. 1 (D) is a view showing an aspect in which the substrate is interacted with the compound when the potential singular points are nearly circular. FIG. 1 (E) is a view in which the compound is nearly circularly arranged on the substrate and the reaction between the compounds occurs. FIG. 1 (F) is a view showing an aspect in which the compound 3 bonded with the potential singular points is interacted with another compound 5 . FIG. 1 (G) is a view showing the compounds bonded with potential singular points and interacted with other compounds to control the conformation of the compounds;
[0035] FIG. 2 is a photograph showing the condition of a substrate. FIG. 2 (A) is the STM photograph of the substrate, and FIG. 2 (B) is a graph showing the height of the line drawn in FIG. 2 (A);
[0036] FIG. 3 is a STM photograph of the (111) surface of the gold substrate after deposition of a small amount of MSTBPP. FIG. 3 (A) is a case in which the terrace edge lines are linear. FIG. 3 (B) is a case in which the terrace edge lines are warped;
[0037] FIG. 4 is a magnified image of a section of FIG. 3A ;
[0038] FIG. 5 is an NC-AFM photograph of MSTBPP on the Au (111) substrate;
[0039] FIG. 6 is an NC-AFM photograph of MSTBPP on the Au (111) substrate with a molecular drawing inset of MSTBPP;
[0040] FIG. 7 is an STM photograph of MSTBPP dispersed on the terrace of the Au (111) substrate; and
[0041] FIG. 8 is a three dimensional image of a molecule obtained from FIG. 7 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] The embodiments of the present invention are specifically explained below based on the drawings. FIG. 1 is a view showing a first embodiment of the present invention.
[0043] FIG. 1 (A) is a drawing illustrating a substrate and a compound. As shown in FIG. 1 (A), to produce nano-devices a substrate 1 is used, and potential singular points 2 which have different potential energy from their surroundings are provided on the substrate 1 . Further, when the nano-device is produced in the present invention, a compound 3 is used, and the compound 3 has a functional group 4 (or functional groups) which interact(s) with the potential singular points.
[0044] In this specification, the ‘nano-device’ means a molecular aggregate in which a bonding position and the like are controlled at a molecular level, wherein the molecular aggregate and the substrate are integrated. It is preferably a device having predetermined functions such as a switching function and an ON/OFF function.
[0045] In this specification, the ‘interaction’ means intermolecular forces such as Van der Waals force, hydrogen bonding, dipole-dipole moment interaction, and a series of interactions related to chemical, physical and/or electrical reaction between neighboring molecules.
[0046] In this specification, the ‘potential singular points’ means a site, an area, or points in which potential energy is locally and greatly changed by chemical or physical factors in comparison with a surrounding site, for example, a recess portion on a substrate. The depth of such a recess is preferably 1 to 50 angstroms, more preferably 5 to 40 angstroms and further preferably 10 to 25 angstroms. The “potential singular points” include the pattern which automatically exists on the substance and defect structures. “Patterns which automatically exist on the substance” include a Herring bone structure on a gold surface and so on. The “defect structures” includes defects of oxygen molecule on the surface of oxide, and scratched shape on Alkali-Halide and so on.
[0047] The potential singular points are preferably formed by using an electron beam, a convergent atomic beam, a convergent ion beam or nanolithography.
[0048] FIG. 1 (B) is a view showing an aspect in which the substrate is interacted with the compound when the potential singular points are nearly linear. The above-mentioned compound is brought in contact with the above-mentioned substrate having the potential singular points. Then, as shown in FIG. 1 (B), the potential singular points 2 on the substrate interact with the functional group 4 of the compound, and the compound is arranged on the substrate. FIG. 1 (C) is a view showing the substrate interacted with the compound when the potential singular points are provided at points of nearly equal intervals. Namely, an intermolecular distance and a space position can be controlled by controlling the interval at which the potential singular points are provided. Accordingly, a nano-device with controlled intramolecular intervals is produced.
[0049] The production process of the present invention is preferably carried out in a chamber with an ultra high vacuum, and the pressure in the chamber is preferably 10 −8 Pascal or less, more preferably 10 −9 Pascal or less and further preferably 10 −10 Pascal or less.
[0050] The compound is accumulated on the substrate by known deposition methods such as, for example, a chemical deposition method and a physical deposition method. The deposition method of the compound is preferably a deposition method using a Knudsen cell at 300 to 400K, or a molecule scattering method by introducing mists in the chamber by a syringe and the like.
[0051] FIG. 1 (D) is a view showing an aspect in which the substrate is interacted with the compound when the potential singular points are nearly circular. In this case, the circular potential singular points 2 interacted with the functional groups 4 of the compounds, and the compounds are arranged in a nearly circular shape. For example, when the potential singular points are provided at equal intervals to form the circle of FIG. 1 (D), the arrangement of the compounds is also at equal intervals. When the compounds are circularly arranged, a chemical reaction of the mutually arranged compounds can be accelerated. A view in which the compounds are nearly circularly arranged on the substrate, and the reaction between the compounds proceeds is shown in FIG. 1 (E).
[0052] Further, in the present invention, the compound 3 bonded with the substrate may be bonded with one or more other compounds 5 . FIG. 1 (F) is a view illustrating the compound 3 bonded with the potential singular points 2 and interacted with other compounds 5 . Thus, a nano-device in which a selected position of the substrate was a starting point can be produced.
[0053] FIG. 1 (G) is a view illustrating the compound 3 bonded with the potential singular points 2 and interacted with other compounds 5 when the position of the potential singular points are formed to be the apex points of a near triangle. As shown in FIG. 1 (G), the conformation of the polymerization of the compound formed on the substrate can be controlled by controlling the position of the potential singular points.
[0054] In the present invention, for example, a compound is accumulated on a metal surface as the substrate. The shape of the substrate may be flat, but a substrate having steps (the potential singular points) of a regular cycle and being arranged in parallel is obtainable by shaving a specific index plane using the single crystal of a metal and carrying out an appropriate thermal treatment. Such substrate is called a finely slant substrate. The metal used for the substrate may include a metal formed on a substrate such as mica or glass by deposition and the like, and a metal itself may be used. However, using a substrate such as mica or glass is preferable. The substrate is further preferably mica. The surface roughness of mica is preferably 50 nm or less, more preferably 1 nm or less, and further preferably 0.5 nm or less. When the surface roughness is around the above range, the surface of a metal is made flat, and the circumstance in which a compound enters into the unevenness which was generated on the surface of a metal can be prevented. The surface roughness means a roughness of a square average (Rs).
[0055] The metal constituting the metal surface includes gold, copper, platinum, silver, tungsten and the like. Among these, gold is preferable and the (111) surface of gold is more preferable. Because the (111) surface of gold is inactive a chemical reaction with a sample molecule and the like is prevented.
[0056] Further, when the thin film of a metal is formed on the substrate, the surface roughness is preferably 50 nm or less, more preferably 10 nm or less, further preferably 5 nm or less, furthermore preferably 1 nm or less and most preferably 0.5 nm or less in particular. When the surface roughness of the thin film of a metal thus formed on the substrate is small, the circumstance in which a compound enters into the recess on the film of a metal can be prevented.
[0057] As the compound having a functional group interacting with the potential singular points, the porphyrin compound represented by the under-mentioned General Formula (I) is preferred. Other preferred compounds are phtalocyanine or phtalocyanine derivatives which may contain metal ions.
[0058] The compound represented by the following General Formula (I) is illustrated below.
(wherein M represents either two hydrogen atoms, a divalent metal, a trivalent metal derivative, or a tetravalent metal derivative; R′ represents either a C 2-12 alkenyl group, a C 2-12 alkenyloxy group, a C 3-6 dienyl group, a C 2-12 alkynyl group, a C 2-12 alkynyloxy group, a hydroxyl group, a C 1-12 alkoxy group, a C 1-12 acyl group, a C 1-30 acyloxy group, a carboxyl group, a C 1-12 alkoxycarbonyl group, a carbamoyl group, a C 1-12 alkylcarbamoyl group, an amino group, a C 1-12 alkylamino group, an arylamino group, a cyano group, an isocyano group, a C 1-12 acylamino group, a nitroso group, a nitro group, a mercapto group, a C 1-12 alkylthio group, a sulfo group, a sulfino group, a C 1-12 alkylsulfonyl group, a thiocyanate group, an isothiocyanate group, a thiocarbonyl group, a sulfamoyl group, a C 1-12 alkylsulfamoyl group, a hydroxyiminomethyl group (—CH═NOH), a C 1-12 alkoxyiminomethyl group, a C 1-12 alkenyloxyiminomethyl group, a C 1-12 alkynyloxyiminomethyl group, a C 1-12 alkyliminomethyl group, a C 1-12 alkylsulfamoyliminomethyl group, a thiocarboxyl group, a hydroxyaminocarbonyl group, an alkoxyaminocarbonyl group, or halogen; X represents either a C 1-12 alkyl group, a C 1-12 alkoxy group, a trialkylsilyloxy group, a phenyldialkylsilyloxy group, or a alkyldiphenylsilyloxy group; Y represents either a hydrogen atom, a hydroxy group, a C 1-30 alkoxy group, a C 2-30 alkenyloxy group, a C 2-30 alkynyloxy group, or a C 1-30 acyloxy group; and each of R 1 to R 8 represents independently either a hydrogen atom, a halogen atom, an amino group, a hydroxy group, a nitro group, a cyano group, or a C 1-3 alkyl group which may optionally have a substituent.)
[0060] In General Formula (I), M represents either two hydrogen atoms, a divalent metal, a trivalent metal derivative, or a tetravalent metal derivative, preferably either two hydrogen atoms, Cu, Zn, Fe, Co, Ni, Ru, Pb, Rh, Pd, Pt, Mn, Sn, Au, Mg, Cd, AlCl, InCl, FeCl, MnCl, SiCl 2 , GeCl 2 , Vo, TiO, SnCl 2 , Fe-Ph, SnC≡C-Ph, or Rh—Cl, and more preferably two hydrogen atoms.
[0061] In General Formula (I), for example, each of R 1 to R 8 represents independently a hydrogen atom, a halogen atom, an amino group, a hydroxy group, a nitro group, a cyano group, or a C 1-3 alkyl group which may optionally have a substituent, and more preferably a hydrogen atom.
[0062] In General Formula (I), R′ functions usually as the functional group interacted with the potential singular points. R′ represents either of a C 2-12 alkenyl group, a C 2-12 alkenyloxy group, a C 3-6 dienyl group, a C 2-12 alkynyl group, a C 2-12 alkynyloxy group, a hydroxyl group, a C 1-12 alkoxy group, a C 1-12 acyl group, a C 1-30 acyloxy group, a carboxyl group, a C 1-12 alkoxycarbonyl group, a carbamoyl group, a C 1-12 alkylcarbamoyl group, an amino group, a C 1-12 alkylamino group, an arylamino group, a cyano group, an isocyano group, a C 1-12 acylamino group, a nitroso group, a nitro group, a mercapto group, a C 1-12 alkylthio group, a sulfo group, a sulfino group, a C 1-12 alkylsulfonyl group, a thiocyanate group, an isothiocyanate group, a thiocarbonyl group, a sulfamoyl group, a C 1-12 alkylsulfamoyl group, a hydroxyiminomethyl group (—CH═NOH), a C 1-12 alkoxyiminomethyl group, a C 1-12 alkenyloxyiminomethyl group, a C 1-12 alkynyloxyiminomethyl group, a C 1-12 alkyliminomethyl group, a C 1-12 alkylsulfamoyliminomethyl group, a thiocarboxyl group, a hydroxyaminocarbonyl group, an alkoxyaminocarbonyl group, or halogen.
[0063] Preferable functional groups for R′ in General Formula (I) are as follows. The C 2-12 alkenyl group includes a vinyl group (CH 2 ═CH—), a 1-propenyl group (CH 3 CH 2 ═CH—), an allyl group (CH 2 ═CHCH 2 —), a 3-methyl-2-butenyl group (CH 3 —C(CH 3 )═CHCH 2 —) and the like. As the C 2-12 alkenyl group, a C 2-8 alkenyl group is preferable, a C 2-6 alkenyl group is more preferable and a C 2-4 alkenyl group is preferable in particular.
[0064] The C 2-12 alkenyloxy group includes a 2-propenyloxy group, a 2-butenyloxy group, a 3-butenyloxy group, a 4-pentenyloxy group, a 9-decen-1-yloxy group, a 11-dodecen- 1 -yloxy group, a 9,12-tetradecadien-1-yloxy group, a 9-hexadecen-1-yloxy group, a 9,12-tetradecadien-1-yloxy group, a 10,12-pentadien-1-yloxy group and the like. As the C 2-12 alkenyloxy group, a C 2-10 alkenyloxy group is preferable, a C 2-8 alkenyloxy group is further preferable, a C 2-6 alkenyloxy group is more preferable and a C 2-4 alkenyloxy group is preferable in particular.
[0065] A C 3-6 dienyl group includes a 1,3-butadienyl group (CH 2 ═CHCH═CH—) and the like.
[0066] The C 2-12 alkynyl group includes an ethynyl group (CH≡C—), a 1-propynyl group, a 2-propynyl group, a 1-butynyl group, a 2-butynyl group, a 3-butynyl group, a 1-propynyl group, a 2-propynyl group, a 3-propynyl group, a 4-propynyl group, a 1-methyl-2-propynyl group and the like. As the C 2-12 alkynyl group, a C 2-8 alkynyl group is preferable, a C 2-6 alkynyl group is further preferable and a C 2-4 alkynyl group is preferable in particular.
[0067] The C 2-12 alkynyloxy group includes an ethynyloxy group, a 1-propynyloxy group, a 2-propynyloxy group, a 1-butynyloxy group, a 2-butynyloxy group, a 3-butynyloxy group, a 1-propynyloxy group, a 2-propynyloxy group, a 3-propynyloxy group, a 4-propynyloxy group, a 1-methyl -2-propynyloxy group, a 5-hexyn-1-yloxy group, a 9-decyn-1-yloxy group, a 11-dodecyn-1-yloxy group, a 10,12-pentacosandiyl-1-yloxy group and the like.
[0068] The C 1-12 alkoxy group (C n H 2n+1 O—) includes a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, a sec-butoxy group, an isobutoxy group, a tert-butoxy group, a pentyloxy group, an amyloxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, a hexadecyloxy group, a docosan-1-yl group, a pentacosan-1-yl group, a triacontan-1-yl group and the like. As the C 1-12 alkoxy group, a C 1-10 alkoxy group is more preferable, a C 1-8 alkoxy group is further preferable and a C 1-6 alkoxy group is preferable in particular.
[0069] The C 1-12 acyl group (RCO—) includes a formyl group (CHO—), an acetyl group (CH 3 CO—), a propionyl group (C 2 H 5 CO—), an isobutyryl group, a valeryl group (C 4 H 9 CO—), a pivaloyl group ((CH 3 ) 3 CCO—), an octanonyl group (CH 3 (CH 2 ) 6 CO—), a lauroyl group (CH 3 (CH 2 ) 10 CO—) and the like.
[0070] The C 1-30 acyloxy group (RCHOO—) includes a formyloxy group, a methoxycarbonyl (acetyloxy) group (CH 3 COO—), an ethoxycarbonyl group (C 2 H 5 COO—), a propionyloxy group, a hexanoyloxy group, an octanoyloxy group, a lauroyloxy group, a palmitoyloxy group, a stearoyloxy group, a pentacosanoyloxy group, a triacontanoyloxy group, a methacryloyloxy group, a 9-decenoyloxy group, a 9-octadecenoyloxy group, a 9,12-octadecadienoyloxy group, a 10,12-pentacosadienoyloxy group, a propioyloxy group, a 9-decinoyloxy group, a 2,4-pentadecadiinoyloxy group, a 10,12-pentacosadiinoyloxy group and the like. As the C 1-30 acyloxy group, a C 1-10 acyloxy group is preferable, a C 1-8 acyloxy group is more preferable, a C 1-6 acyloxy group is further preferable and a C 1-4 acyloxy group is preferable in particular.
[0071] As the C 1-12 alkoxycarbonyl group, a C 1-6 alkoxycarbonyl group (ROCO—) is preferable, and as the C 1-6 alkoxycarbonyl group (ROCO—), a methoxycarbonyl group, an ethoxycarbonyl group and the like are mentioned. Further, in the present specification, R means an alkyl group unless otherwise noticed.
[0072] As the C 1-12 alkylcarbamoyl group, a C 1-6 alkylcarbamoyl group (R 2 NCO—) is preferable, and the C 1-6 alkylcarbamoyl group (R 2 NCO—) includes a methylcarbamoyl group (CH 3 NHCO—), a dimethylcarbamoyl group (CH 3 ) 2 NCO—), an ethylcarbamoyl group, a diethylcarbamoyl group, a methylethylcarbamoyl group and the like.
[0073] As the C 1-12 alkylamino group, a C 1-6 alkylamino group is preferable, and the C 1-6 alkylamino group includes secondary C 1-6 alkylamino groups such as a methylamino group and an ethylamino group, tertiary C 1-6 alkylamino groups such as a dimethylamino group, a diethylamino group and a methylethylamino group and the like.
[0074] As the C 1-12 acylamino group, a C 1-6 acylamino group (RCONH—) is preferable, and the C 1-6 acylamino group (RCONH—) includes an acetylamino group (CH 3 CONH—) and the like.
[0075] As the C 1-12 alkylthio group, a C 1-6 alkylthio group is preferable, and as the C 1-6 alkylthio group, a methylthio group (CH 3 S—), an ethylthio group and a propylthio group are preferable, and a methylthio group is preferable in particular.
[0076] As the C 1-12 alkylsulfonyl group, a C 1-6 alkylsulfonyl group is preferable, and the C 1-6 alkylsulfonyl group includes a methylsulfonyl group (CH 3 SO 2 -), an ethylsulfonyl group, a propylsulfonyl group and the like.
[0077] As the C 1-12 alkylsulfamoyl group, a C 1-6 alkylsulfamoyl group is preferable, and the C 1-6 alkylsulfamoyl group includes a methylsulfamoyl group and an ethylsulfamoyl group.
[0078] As the C 1-12 alkoxyiminomethyl group, a C 1-6 alkoxyiminomethyl group is preferable, and a methoxyiminomethyl group and an ethoxyiminomethyl group are more preferable.
[0079] As the C 1-12 alkenyloxyiminomethyl group, a C 1-6 alkenyloxyiminomethyl group is preferable.
[0080] As the C 1-12 alkynyloxyiminomethyl group, a C 1-6 alkynyloxyiminomethyl group is preferable.
[0081] As the C 1-12 alkyliminomethyl group, a C 1-6 alkyliminomethyl group is preferable.
[0082] As the C 1-12 alkylsulfamoyliminomethyl group, a C 1-6 alkylsulfamoyliminomethyl group is preferable.
[0083] As the alkoxyaminocarbonyl group, a C 1-6 alkoxyaminocarbonyl group is preferable.
[0084] Halogen includes fluorine, chlorine, bromine, sulfur and the like.
[0085] In General Formula (I), R′ is preferably a methylthio group in particular.
[0086] In General Formula (I), X includes a C 1-8 alkyl group, a C 1-8 alkoxy group, a trialkylsilyloxy group, and a phenyldialkylsilyloxy group. As the C 1-8 alkyl group, a C 1-6 alkyl group is preferable. As the C 1-8 alkoxy group, a C 1-6 alkoxy group is preferable. X is most preferably a tert-butyl group.
[0087] In General Formula (I), Y represents either of a hydrogen atom, a hydroxy group, a C 1-30 alkoxy group, a C 2-30 alkenyloxy group, a C 2-30 alkynyloxy group, or a C 1-30 acyloxy group. The C 1-30 alkoxy group (C n H 2n+1 O—) includes a methoxy group, an ethoxy group, a n-propoxy group, an isopropoxy group, a n-butoxy group, a sec-butoxy group, an isobutoxy group, a tert-butoxy group, a pentyloxy group, an amyloxy group, an octyloxy group, a decyloxy group, a dodecyloxy group, a hexadecyloxy group, a docosan-1-yl group, a pentacosan-1-yl group, a triacontan-1-yl group and the like. As the C 1-30 alkoxy group, a C 1-10 alkoxy group is preferable, a C 1-8 alkoxy group is further preferable and a C 1-6 alkoxy group is preferable in particular.
[0088] The C 2-30 alkenyloxy group includes a 2-propenyloxy group, a 2-butenyloxy group, a 3-butenyloxy group, a 4-pentenyloxy group, a 9-decen-1-yloxy group, a 11-dodecen-1-yloxy group, a 9,12-tetradecadien-1-yloxy group, a 9-hexadecen-1-yloxy group, a 9,12-tetradecadien-1-yloxy group, a 10,12-pentadien-1-yloxy group and the like. As the C 2-30 alkenyloxy group, a C 2-10 alkenyloxy group is preferable, a C 2-8 alkenyloxy group is further preferable, a C 2-6 alkenyloxy group is more preferable and a C 2-4 alkenyloxy group is preferable in particular.
[0089] The C 2-30 alkynyloxy group includes an ethynyloxy group, a 1-propynyloxy group, a 2-propynyloxy group, a 1-butynyloxy group, a 2-butynyloxy group, a 3-butynyloxy group, a 1-propynyloxy group, a 2-propynyloxy group, a 3-propynyloxy group, a 4-propynyloxy group, a 1-methyl -2-propynyloxy group, a 5-hexyn-1-yloxy group, a 9-decyn-1-yloxy group, a 11-dodecyn-1-yloxy group, a 10,12-pentacosandiyl-1-yloxy group, a 2,9-triacontayn-1-yloxy group and the like.
[0090] The C 1-30 acyloxy group (RCHOO—) includes a formyloxy group, a methoxycarbonyl (acetyloxy) group (CH 3 COO—), an ethoxycarbonyl group (C 2 H 5 COO—), a propionyloxy group, a hexanoyloxy group, an octanoyloxy group, a lauroyloxy group, a palmitoyloxy group, a stearoyloxy group, a pentacosanoyloxy group, a triacontanoyloxy group, a methacryloyloxy group, a 9-decenoyloxy group, a 9-octadecenoyloxy group, a 9,12-octadecadienoyloxy group, a 10,12-pentacosadienoyloxy group, a propioyloxy group, a 9-decinoyloxy group, a 2,4-pentadecadiinoyloxy group, a 10,12-pentacosadiinoyloxy group and the like. As the C 1-30 acyloxy group, a C 1-10 acyloxy group is preferable, a C 1-8 acyloxy group is more preferable, a C 1-6 acyloxy group is further preferable and a C 1-4 acyloxy group is preferable in particular.
[0091] In General Formula (I), M is two hydrogen atoms, and R′ is more preferably either of a C 2-12 alkylthio group, a cyano group, a hydroxy group, a carboxyl group, an amino group, a formyl group, a carbamoyl group, a nitro group, a hydroxyiminomethyl group (—CH═NOH), an ethynyl group, a hydroxyaminocarbonyl group, or a sulfamoyl group, and R′ is further preferably a methylthio group.
[0092] Other compounds include any compound being interacted with the potential singular points utilizing the functional groups fore-mentioned, and having a functional group interact with a functional group other than the group used for bonding with the substrate. It is interacted through a functional group of a compound being interacted with the substrate. Example of the compound includes a compound containing a double bond or a triple bond as the functional group, etc.
EXAMPLE 1
[0093] Specifically detailed below is an experimental example utilizing a methylthiophenyl group as the functional group interacted with potential singular points on a substrate, a porphyrin-base molecular structure is utilized as the objective member to which the functional group is bonded, and the potential singular points are terrace edge lines formed on a single crystal plane (finely slant 111 plane) of gold.
[0094] The experimental example below was analyzed with a temperature-variable type scanning probe microscope system which was installed in an ultra high vacuum chamber that was controlled so as to maintain an inner pressure of 10 −8 Pascal or less. The experiment was further analyzed by a scanning type electron tunneling microscopy mode (STM mode) and a non-contact atomic force microscopy mode (NC-AFM mode). A needle-pointed tungsten material to which electrolytic polishing was carried out, in the STM mode, and an n-doped electroconductive silicon cantilever that had a modulus of elasticity k of about 50 N/m and a resonance frequency f of about 300 kHz, in the NC-AFM mode were respectively used. A sample holder, a sample and an atomic probe portion were cooled to liquid nitrogen temperature with a cooling apparatus which was prepared for ultra high vacuum, in order to suppress the thermal vibration of an observation object at measurement and improve the resolution of acquired data.
[0095] The MSTBPP compound in the experimental example was produced by oxidizing 3,5-di-tert-butylbenzaldehyde and 4-methylthiobenzaldehyde with 2,3-dichloro-5,6-dicyano-1,4-benzoquinoline (DDQ) (T. Akiyama et. al., Chem. Let. (1996) 907, and F. Li et. al., Tetrahedron 53 (1997) 12339).
[0096] With respect to the substrate used for the observation, the impurities and non-adhering articles of its surface were removed by carrying out luster scanning while irradiating an Ar ion beam which was accelerated under an ultra high vacuum environment with a voltage difference of 1 kV against the finely slant (111) plane of the single crystal of gold, and further, the reconstruction of the surface was promoted by keeping the whole substrate at 900 K by heating. The process was repeated depending on the surface condition of the substrate obtained, to finally obtain the substrate on which clean and flat areas at atomic level were arranged with a fixed rule ( FIG. 2 ). FIG. 2 (A) is the STM photograph of the substrate, and FIG. 2 (B) is a graph illustrating the height of the line portion which is shown in FIG. 2 (A). Successively, the objective molecule was deposited on the substrate by irradiating an MSTBPP beam (hereat, the molecular beam was prepared by heating the sample at 300 to 400 K in a Knudsen cell) that was focused to the specific point on the substrate. Then, the whole substrate was further heated at 300 to 400 K for a short time to facilitate even cooling.
[0097] After completion of the deposition process, the sample was moved to another ultra high vacuum chamber without breaking ultra high vacuum conditions, and submitted to an observation experiment with a nanoprobe microscope. Feedback control based on the predetermined condition of usual tunneling electric current value was adopted for STM mode measurement, and the frequency modulating feedback mode (FM-feedback mode) with a frequency shift of 50 Hz to 200 Hz was adopted for NC-AFM mode measurement. The detailed motion principle of the measurement apparatus and experimental condition are described in the literature of Cbunli Bai (Scanning Tunneling Microscopy, Springer 1995) for the STM mode and in the literature of Morita et. al., (Non-contact Atomic Force Microscopy) for the NC-AFM mode.
[0098] The STM image of the (111) surface of the gold substrate after deposition of a small amount of MSTBPP is shown in FIG. 3 . It can be grasped from FIG. 3 (A) that the molecules on the substrate are selectively and predominantly arranged along the edges of terraces which were formed on the substrate. Further, it can be grasped from FIG. 3 (A) that the central positions of clear points corresponding to the molecule are arranged just at the boundary edges of the terraces. Namely, in the system, the centers of the clear points are situated at the sites (the potential singular points) of the boundary edge in which the potential is different from the surroundings. FIG. 3 (B) is the STM image when the terrace edge lines were warped. It can also be grasped in this case that the molecule is always arranged along the edge lines (the potential singular points). Namely, the orientation of the molecule is determined by the geometrical shape of the substrate without depending on the crystal direction of the substrate. This is clear from the magnified image shown in FIG. 4 . It was reported in the primary study of TBPP with a scanning tunneling microscopy (STM) that there are some differences in methods by which the molecule is absorbed and the methods change depending on the material of the substrate. The molecule which was dispersed on the Au (111) substrate remains on the inside of the terraces along the boundary lines. To the contrary, the molecule on Cu (100) is absorbed just on the boundary lines of terraces in a condition in which the central porphyrin ring crosses the boundary lines [Ch. Loppacher et. al., Appl. Phys. A72, (2001) 105]. It is considered that the reason why the difference occurs in the experiments of Cu (100) and Au (111) regarding the TBPP molecule is the difference in the strength of the attraction interaction of the molecule with the substrate. In general, the TBPP molecule is more strongly adsorbed on Cu (100) than Au (111). From this viewpoint, the results shown in FIG. 3 (A), FIG. 3 (B) and FIG. 4 are obtained because the methylthiophenyl group introduced in a porphyrin-base molecule strengthened the attraction interaction with the potential singular points on the substrate. The tendency is not lost even when the total amount of deposition was increased, therefore it is elucidated that it is a universal tendency which is observed in the combination of a Au (111) finely slant substrate with MSTBPP molecules.
[0099] FIG. 5 and FIG. 6 show the NC-AFM image of MSTBPP on the Au (111) substrate with a range of 0.2 ML, and the clear points in the image come from the individual MSTBPP molecule respectively. Most molecules are arranged at the edges of respective terraces by the same method as described for FIG. 3 and FIG. 4 until the edge lines are completely occupied by the molecules. Considering the morphological feature of MTTBPP which is arranged along the edges of the terraces, it can be concluded that a powerful attraction interaction exists between the MSTBPP molecule and the Au (111) substrate in like manner as the case of combining Cu (100) with the TBPP molecule.
[0100] The clear points of FIG. 5 come from the individual MSTBPP molecule which is comprised of three points which are respectively one slightly clear point and two normal clear points. This can be further clearly understood by the STM image shown in FIG. 6 . When these are compared with the STM image (four leaves mode configuration) of TBPP which is reported in the non-patent literature 3: T. A. Jung, H. R. Schlittler and J. K. Gimzewski, Nature 386 (1997) 696, one leaf among the four leaves mode configuration is lost in the case of MSTBPP. The four leaves mode configuration obtained in the STM observation of the TBPP molecule comes from four di-tert-butylphenyl groups which the TBPP molecule has. Collectively judging the structural difference of the MSTBPP molecule and the TBPP molecule and data that was obtained from the NC-AFM image (which mainly reflects the unevenness in the shape of an observation sample) and the STM image (which mainly reflects the space distribution shape of electron tunneling probability), it can be concluded that the deficit sites in the MSTBPP molecule image that were seen in the image in FIG. 5 come from the methylthiophenyl group. The sites of the methylthiophenyl group always face to the terrace edges, and thus are arranged to be directly brought in contact with the edge wall as shown in FIG. 6 . This suggests that the attraction between the MSTBPP molecule and the terrace edges of the substrate is provoked by the methylthiophenyl group. It has been predicted in the study of self-organization film (SAM film) that there is a possibility of exhibiting a powerful attraction on a metal substrate (in particular, a metal plate in many cases), because a portion of a substituent containing a sulfur has a localized non-common electron pair at the site of sulfur. The present confirms this detail at the molecule level and is the first in the world to do so. Further, the primary factor of the attraction interaction which the methylthiophenyl group provided to the host molecule is not diffused over the whole molecule but remains at the sulfur portion of the methylthiophenyl group. This attraction interaction is the support and driving force of the basic mechanism by which the MSTBPP molecule is arranged at the terrace edge lines while keeping regularity at positions relative to the ridges of terrace edges which were formed on the Au substrate as the potential singular points.
[0101] A similar phenomenon is observed for the MSTBPP molecule which was dispersed on the terraces that were formed on the Au (111) plane. Specifically, the phenomenon is seen in the NC-AFM image shown in FIG. 7 . In the case of the TBPP molecule, the two dimensional island configuration, in which a great number of molecules were regularly arranged, is observed. (T. Yokoyama, S Yokoyama, T. Kamikado and S. Mashiko, J. Chem. Phys. 115 (2001) 3814). However, in the case of the MSTBPP molecule, the tendency is not observed at all. This fact can be understood by considering the existence of a powerful attraction which is generated between the methylthiophenyl group of MSTBPP and the substrate. The molecules in the molecular beam which were irradiated on the substrate have a given quantity of thermal motion energy just after their landing on the substrate. Then, the molecules discharge thermal motion energy while freely moving on the substrate for a while, as the thermal motion energy is exhausted, the molecules move to sites which are energetically stable. When the attraction between the molecules and the substrate is not stronger than the intermolecular attraction on the same terraces, it is considered that the molecules are adjacently arranged just before termination of the movement, in like manner as the case of TBPP, to form the above-mentioned island configuration. However, since the attraction between the molecules and the substrate is by far stronger than the intermolecular attraction on the same terraces in the case of the MSTBPP molecule, each of the molecules exhausts adequately the motion energy when some potential singular points exist on the surfaces of terraces, and are adsorbed on the surfaces before forming islands. As a result, each of the molecules cannot move freely after the position is fixed on the surface. In this case, it is elucidated that intermolecular interaction slightly influences the arrangement of relative mode. therefore the formation of the island configuration does not occur.
[0102] The three dimensional image of a MSTBPP molecule which was arranged on the terrace is shown in FIG. 8 . The molecular image is constituted by three large brilliant points and one small brilliant point. Collecting the experimental facts hitherto, it can be concluded that the portion shown with a white circle in the drawing is the methylthiophenyl group. In this case, the brilliant portion that is situated at the counter side of the methylthiophenyl group molecule against molecular center is the leg of di-tert-butylphenyl. The portion is observed slightly dark in comparison with the adjacent two brilliant points. The difference means that the planar shape of the MSTBPP molecule is slightly warped on the terrace. It is elucidated that the methylthiophenyl group is attracted to the substrate plane by the attraction interaction which is generated between the methylthiophenyl group and the Au (111) plane therefore an asymmetric force was generated in the molecule. This illustrates that even if the molecule exists on the terrace, the primary factor of the attraction interaction which the methylthiophenyl group provided to the host molecule is not diffused over the whole molecule but remains at the sulfur portion of the methylthiophenyl group, and it can be applied as the mechanism controlling the potential singular points on the Au substrate and the relative positional relation of the molecule.
[0103] As described above, the configuration and the mode of MSTBPP which was deposited on the Au (111) finely slant substrate were studied using STM and NC-AFM. There was obtained an image having adequate resolution for elucidating the specific arrangement situation and configuration of MSTBPP. It was clarified that the methylthiophenyl group of the molecule expresses the selective attraction interaction against the potential singular points formed on the Au (111) substrate. It was clarified that the site expressing the force is not dispersed over the whole host molecule but remains localized at the sulfur portion of the methylthiophenyl group which was bonded with the molecule and controls the relative mode of the molecule against the substrate. Thus, it was clarified that the methylthio group (methylthiophenyl group) of the porphyrin derivative having a methylthio group (methylthiophenyl group) in the molecule is selectively and strongly interacted with points in which potential is different from the surrounding area such as a rim portion of a metal substrate, and controls the relative positional relation of the molecule against the potential singular points on the substrate.
[0104] According to the present invention, there can be controlled the conformation at a molecular level and chemical reactions at a molecular level that could not heretofore be controlled. Accordingly, the present invention can be applied for a novel chemical reaction in which the reaction is controlled at a molecular level.
[0105] According to the present invention, the molecular device with correct regularity which controlled the reaction position can be produced. Accordingly, the present invention can be applied for a process for producing a bottom-up type nano-device wherein the space position is controlled at a molecular level.
[0106] According to the present invention, since the nano-device wherein the space position is controlled at a molecular level can be provided, it can provide not only a new material and a new device, but also can be applied to various technical fields such as optical information, information technology, electronic and electric technology, medical equipments, bio technology and environmental repairing. | 4y
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is the US National Stage of International Application No. PCT/EP2003/007139, filed Jul. 3, 2003 and claims the benefit thereof. The International Application claims the benefits of European Patent application No. 02015282.3 EP filed Jul. 9, 2002, both of the applications are incorporated by reference herein in their entirety.
FIELD OF THE INVENTION
[0002] This invention relates to a component, especially a blade or vane of a gas turbine, with a high oxidation resistance.
BACKGROUND OF THE INVENTION
[0003] Metallic components, which are exposed to high temperature must be protected against heat and corrosion.
[0004] Especially for gas turbines with its combustion chamber or its turbine blades or vanes it is common to protect the components with an intermediate, protective MCrAlY layer (M=Fe, Co, Ni), which provides oxidation resistance, and a ceramic thermal barrier coating, which protects the substrate of the metallic component against the heat.
[0005] An aluminium oxide layer is formed between the MCrAlY— and the thermal barrier coating due to oxidation.
[0006] For a long life term of a coated component it is required to have a good connection between the MCrAlY layer and the thermal barrier coating, which is provided by the bonding of the thermal barrier coating and the oxide layer onto the MCrAlY layer.
[0007] If a thermal mismatch between the two interconnecting layers prevails or if the ceramic layer has no good bonding to the aluminium oxide layer formed on the MCrAlY layer, spallation of the thermal barrier coating will occur.
[0008] From the U.S. Pat. No. 6,287,644 a continuously graded MCrAlY bond coat is known which has an continuously increasing amount of Chromium, Silicon or Zirconium with increasing distance from the underlying substrate in order to reduce the thermal mismatch between the bond coat and the thermal barrier coating by adjusting the coefficient of thermal expansion.
[0009] The U.S. Pat. No. 5,792,521 shows a multi-layered thermal barrier coating.
[0010] The U.S. Pat. No. 5,514,482 discloses a thermal barrier coating system for superalloy components which eliminates the MCrAlY layer by using an aluminide coating layer such as NiAl, which must have a sufficiently high thickness in order to obtain its desired properties. Similar is known from the U.S. Pat. No. 6,255,001.
[0011] The NiAl layer has the disadvantage, that it is very brittle which leads to early spallation of the onlaying thermal barrier coating.
[0012] The EP 1 082 216 B1 shows an MCrAlY layer having the γ-phase at its outer layer. But the aluminium content is high and this γ-phase of the outer layer is only obtained by re-melting or depositing from a liquid phase in an expensive way, because additional equipment is needed for the process of re-melting or coating with liquid phase.
SUMMARY OF THE INVENTION
[0013] In accordance with the foregoing is an object of the invention to describe a protective layer with a good oxidation resistance and also with a good bonding to the thermal barrier coating.
[0014] The task of the invention is solved by a protective layer which has one underlying conventional MCrAlY layer on which different compositions of MCrAlY and/or other compositions are present as an outer layer.
[0015] One possibility is that the outer layer zone has a composition chosen such that it possesses the β-NiAl-structure.
[0016] Especially the MCrAlY layer, which consists of γ-Ni solid solution, is chosen such, that the material of the MCrAlY-layer can be applied e.g. by plasma-spraying. This has the advantage that the outer layer can be deposited in the same coating equipment directly after the deposition of the inner layer (MCrAlY) without re-melting the surface in another apparatus.
[0017] The protective layer can be a continuously graded, a two layered or a multi-layered coating.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 shows a heat resistant component as known by state of the art,
[0019] FIG. 2, 3 shows examples of an inventive oxidation resistant component.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The invention may be embodied in many different forms and should not be construed as limited to the illustrated embodiments set forth herein. Rather, these illustrated embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.
[0021] FIG. 1 shows a heat resistant component as known by state of the art.
[0022] The highly oxidation resistant component has a substrate 4 , a MCrAlY layer 7 on the substrate, on which a thermally grown oxide layer 10 (TGO) is formed or applied and finally an outer thermal barrier coating 13 .
[0023] FIG. 2 shows an highly oxidation resistant component 1 according the invention.
[0024] The component 1 can be a part of gas turbine, especially a turbine blade or vane or heat shield.
[0025] The substrate 4 is metallic, e.g. a super alloy (Ni—Al-based, e.g.)
[0026] On the substrate 4 the MCrAlY layer zone 16 is a conventional MCrAlY layer 16 of the type e.g. NiCoCrAlY with a typical composition (in wt %) 10%-50% Cobalt (Co), 10%-40% Cromium (Cr), 6%-15% Aluminium (Al), 0.02%-0.5% Yttrium (Y) and Nickel (Ni) as base or balance.
[0027] This MCrAlY layer 16 may contain further elements such as: 0.1%-2% Silicon (Si), 0.2%-8% Tantalum (Ta), 0.2%-5% Rhenium (Re).
[0028] Instead at least a part of Yttrium or in addition this MCrAlY layer zone 16 can also contain Hafnium (Hf) and/or Zirconium (Zr) and/or Lanthanum (La) and/or Cerium (Ce) or other elements of the Lanthanide group.
[0029] The thickness of this conventional layer 16 is in the range from 100 to 500 micrometer and is applied by plasma spraying (VPS, APS) or other conventional coating methods.
[0030] In this example the inventive highly oxidation resistant component 1 reveals a MCrAlY layer 16 with another outer layer zone 19 on top, which forms together with the layer zone 16 the protective layer 17 .
[0031] For example, the outer layer zone 19 consists of the phase β-NiAl. The thickness of this layer 19 is in the range between 1 and 75 micrometer, especially up to 50 micrometer.
[0032] The disadvantage of brittleness of the β-NiAl phase is overcome by the fact that the β-NiAl layer 19 is thin compared to the MCrAlY layer 16 .
[0033] The outer layer 19 can solely consist of the two elements Ni and Al. The concentration of these two elements is given by the binary phase diagram Ni—Al and must be chosen in such a way that the outer layer 19 consists of pure β-NiAl phase at the temperature at which the oxidation of the layer 19 , which forms the TGO 10 , occurs (21-37 wt % Al or 32-50 at % Al).
[0034] Nevertheless this β-NiAl phase can contain further alloying elements as long as these elements do not destroy the phase β-NiAl phase structure. Examples of such alloying elements are chromium and/or cobalt. The maximum concentration of chromium is given by the area of the β-phase in the ternary phase diagram Ni—Al—Cr at the relevant temperatures.
[0035] Cobalt has a high solubility in the β-NiAl phase and can nearly completely replace the nickel in the NiAl-phase.
[0036] Similar further alloying elements can be chosen such as Si (Silicon), Re (Rhenium), Ta (Tantal).
[0037] The main requirement of the concentration of the alloying elements is, that it does not lead to the development of new multi-phase microstructures.
[0038] Also elements (additions) such as Hafnium, Zirconium, Lanthanum, Cerium or other elements of the Lanthanide group, which are frequently added to improve the properties of MCrAlY coatings, can be added to the β-phase layer.
[0039] The NiAl based layer is applied by plasma spraying (VPS, APS) and/or other conventional coating methods.
[0040] The advantage of the β-NiAl phase structure is that a meta-stable aluminium oxide (θ—or a mixture with γ-phase) is formed in the beginning of the oxidation of the layer 19 .
[0041] The TGO (e.g. aluminium oxide layer) 10 which is formed or applied on the outer layer 19 has a desirable needle like structure and leads therefore to a good anchoring between the TGO 10 and the ceramic thermal barrier coating 13 .
[0042] On conventional MCrAlY coatings, usually the stable α-phase of aluminium oxide is formed upon high temperatures exposure of the coating. However during the use of the heat resistant component 1 with its outer layer 19 meta-stable aluminium oxide 10 is allowed to be transformed into the stabile α-phase during high temperature exposure, which leads to a desirable microporosity in the TGO.
[0043] Another possibility of a component 1 according to the invention is given in such a way that the standard MCrAlY layer 16 is of the type NiCoCrAlY and has an amount of aluminium between 8% to 14 wt % with a thickness from 50 to 600 micrometer, especially between 100 and 300 micrometer.
[0044] On this MCrAlY layer 16 a second MCrAlY layer zone 19 of the type NiCoCrAlY is applied. The composition of this second layer is chosen in such a way that the modified MCrAlY layer 19 as outer layer 19 shows at a high application temperature (900°-1100° C.) a pure γ-Ni matrix. A suitable composition of the second layer ( 19 ) can be derived from the known phase diagrams Ni—Al, Ni—Cr, Co—Al, Co—Cr, Ni—Cr—Al, Co—Cr—Al.
[0045] Compared to conventional MCrAlY coatings this modified MCrAlY layer 19 has a lower concentration of aluminium with a concentration of aluminium between 3-6.5 wt %, which can easily be applied by plasma spraying by only changing the powder feed of the plasma spraying apparatus accordingly.
[0046] However, layer 19 can also be applied by other conventional coating methods.
[0047] A typical composition of this modified MCrAlY layer 19 which consists of γ-phase is: 15-40 wt % chromium (Cr), 5-80 wt % Cobalt (Co), 3-6.5 wt % Aluminium (Al) and Ni base, especially 20-30 wt % Cr, 10-30 wt % Co, 5-6 wt % Al and Ni base.
[0048] Instead of Yttrium this MCrAlY layer zone 19 can also contain further additions of so called reactive elements such as Hafnium (Hf) and/or Zirconium (Zr) and/or Lanthanum (La) and/or Cerium (Ce) or other elements of the Lanthanide group, which are commonly used to improve the oxidation properties of MCrAlY coatings.
[0049] The total concentration of these reactive elements may be in the range between 0.01 and 1 wt %, especially between 0.03 and 0.5 wt %.
[0050] The thickness of the modified MCrAlY layer 19 is between 1 and 80 micrometer especially between 3 and 20 micrometer.
[0051] Further alloying elements can be chosen such as Sc (Scandium), Titanium (Ti), Re (Rhenium), Ta (Tantalum), Si (Silicon).
[0052] A heat treatment prior to applying a thermal barrier coating can be carried out in an atmosphere with a low oxygen partial pressure, especially at 10 −7 and 10 −15 bar.
[0053] The formation of the desired meta-stable aluminium oxide on top of the modified γ-phase based MCrAlY layer 19 can be obtained by oxidation of the modified MCrAlY layer 19 at a temperature between 850° C. and 1000° C. prior to opposition of a thermal barrier coating, especially between 875° C. and 925° C. for 2-100 hours, especially between 5 and 15 hours.
[0054] The formation of these meta-stabile aluminium oxide during that mentioned oxidation process can be promoted by addition of water vapour (0.2-50 vol %, especially 20-50 vol %) in the oxidation atmosphere or by the use of an atmosphere with a very low oxygen partial pressure at a temperature between 800° C. and 1100° C., especially between 850° C. and 1050° C.
[0055] In addition to water vapour the atmosphere can also contain non-oxidizing gases such as nitrogen, argon or helium.
[0056] Because the modified MCrAlY layer 19 is thin, aluminium from the inner or standard MCrAlY layer 16 can diffuse through the modified MCrAlY layer 19 in order to support the formation of aluminium oxide on the outer surface of the layer 19 during long term service, which could not be performed by the modified MCrAlY layer 19 alone because of its low concentration of aluminium.
[0057] FIG. 2 shows a two layered protective layer 17 .
[0058] FIG. 3 shows a component with a high oxidation resistance according to the invention.
[0059] The concentration c of the MCrAlY layer 16 is continuously graded in such a way, that near the substrate 4 the composition of the MCrAlY layer 16 is given by a standard MCrAlY layer 16 as described in FIG. 2 or 1 , and that near the thermal barrier coating 13 the composition of the outer layer 19 shows the composition of the layer 19 as described in FIG. 2 .
[0060] On the outer layer zone ( 19 ) a thermal barrier coating (TBC) (13) is applied. Due to the good oxidation resistance of the protective layer ( 17 ) and the good bonding of the TBC to the TGO ( 10 ) due to adjustment of structure, phases and microstructure the life term of the component 1 is prolonged. | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to hydraulic systems generally and more particularly to an improved flow control valve and a hydraulic actuator system employing the valve.
The present invention is an improvement on the valves and systems disclosed in my earlier patents, e.g. U.S. Pat. Nos. 4,696,163 and 4,766,728. Both of those patents relate to flow matching valves and bidirectional actuator systems employing the valves. The particular systems disclosed in those patents employed stepper motors to operate a bidirectional hydraulic gear pump. The pumps were necessarily finished to very close tolerances in order to have low leakage. While these prior art systems provided for very precise control of a hydraulic actuator or piston, cost was relatively high due both to the cost of the stepper motors employed and the electronic driver circuitry necessitated by the use of those motors.
Among the several objects of the present invention may be noted the provision of a hydraulic actuator system which can utilize more common a.c. and d.c. motors; the provision of such a system in which the motor is not loaded when no movement is required of the actuator; the provision of such a system in which the hydraulic operation will act as a brake on the motor; the provision of such a system which does not require exceptionally low leakage pumps to drive the system; the provision of such a system which will provide highly precise control of an actuator; the provision of such a system which will provide for bidirectional operation of an actuator; the provision of such a system which is highly reliable and which is of relatively simple and inexpensive construction. Other objects and features will be in part apparent and in part pointed out hereinafter.
SUMMARY OF THE INVENTION
In a hydraulic actuator system in accordance with the present invention, a bidirectional hydraulic actuator, e.g. a double-ended cylinder and piston, is driven from a bidirectional pump through a hydraulic system which employs a pair of combination poppet/spool valves to control the operation of the actuator. Flow introduced through the source port of one valve lifts the poppet of the other valve on its way to one side of the cylinder and this in turn opens a throttling port to modulate return flow from the other side of the cylinder.
In accordance with one aspect of the present invention, the novel control valve employed utilizes a spool valve housing having a source port opening into one end of the spool valve bore. A poppet check valve element having an operative diameter substantially equal to the bore diameter is provided in alignment with the bore. In the bore, a spool valve element is mechanically connected to the poppet valve element by a stem of a diameter smaller than the bore. The spool valve element includes an interior passage or chamber. The side of the spool valve element opposite the stem is open to the source port and movement of the spool valve element responsive to pressure at the source port is operative to open the poppet valve. The spool valve housing and the spool valve element together form both a throttle port which is opened to the interior chamber by displacement of the poppet valve element. The spool valve element and housing also form a source drain port which is opened to the source port by displacement of the spool valve element beyond that opening the throttle port. A check valve permits flow from the interior chamber to the source port.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view, in section, of a novel flow control valve in accordance with the present invention;
FIG. 2 is a diagrammatic illustration of a double-acting hydraulic cylinder actuator system constructed in accordance with the present invention and employing the control valve of FIG. 1.
Corresponding reference characters indicate corresponding parts throughout the several views of the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a valve housing 11 providing aligned bores 13 and 15 which receive, respectively, a poppet or check valve element 17 and a spool valve element 19. The bores 13 and 15 are of equal diameter forming chambers 14 and 16. The poppet valve element 17 and the spool valve element 19 are connected by a stem 21 which is of smaller diameter than the bores 13 and 15. A source port 23 opens into the portion of the bore 15 below the spool valve element 19 and a load port 24 opens into the space above the poppet valve element 17. The space below the poppet valve element connects to a port 26 through the housing. This port is referred to herein as a load drain port, a somewhat arbitrary designation.
For purposes of illustration, the housing and valve elements are shown as solid or integral pieces. However, as will be understood by those skilled in the art, these elements must be necessarily assembled from component pieces in order to arrive at the completed construction shown. The techniques for building up such components, however, are known in the art and thus are not described in detail herein. Likewise, for ease of description, various elements are described as being "above" or "below" each other in accordance with the orientation shown in the drawing but it should be understood that the valve when in use may be in any orientation.
The housing 11 includes, around the bore 15, a pair of axially spaced annular grooves 27 and 29 which provide valving and throttling functions in connection with the spool valve element 19 as described in greater detail hereinafter. Annular groove 27 is connected to a port 28 through the housing 11. The annular groove 27 on the interior of bore 15 cooperates with an annular groove 31 on the exterior surface of the valving element 19 to provide a throttling action as described in greater detail hereinafter. When the valving elements are in their lowermost positions as shown, the hydraulic connection between grooves 27 and 31 is effectively cut off.
Annular groove 29 communicates with a port 33 through the housing 11 and cooperates with the bottom face of the valving element 19 to open a hydraulic connection between the source port 23 and the port 33 when the valving elements have moved a predetermined distance, upwardly as illustrated. The valving elements are normally biased toward this lowermost or closed position by a spring 35 in the space above the spool valve element 19 in the bore 15. Port 33 is referred to herein as a source drain port, an essentially arbitrary designation.
Within the spool valve element 19, a series of internal passageways or internal chamber 25 connects the groove 31 with a check valve constituted by a seat in the bottom surface of the valving element 19 together with a spherical valving element 37. Valving element 37 is biased into engagement with the seat by a spring 39 whose lower end rests on housing 11. Preferably, the space (16) in the bore 19 above the spool valve element 19 is also vented into the interior chamber 25.
With the ball element 37 resting in its seat, it can be seen that fluid introduced through the source port 23 will cause both the spool valve element 19 and the poppet valve element 17 to be lifted. As such lifting progresses, the poppet valve element 17 essentially immediately opens the connection between the load port 24 and the load drain port 26. Slight additional upward movement of the valve elements opens the hydraulic connections into the annular grooves 27 and 29. While it is preferred that these connections open at approximately the same position, the throttling port (groove 27) should be exposed slightly before the groove 29.
Referring now to FIG. 2, a prime mover or actuator is indicated generally by reference character 121 and comprises piston 123 and cylinder 125. The double rod ended piston provides equal annular areas on both faces of the piston. For providing fail safe operation in certain applications, the piston is heavily biased to the right by a spring 126 so that the volume to the right of the piston can normally be considered to be the higher pressure side.
A bi-directional, positive displacement pump 127 is utilized for providing hydraulic fluid under pressure suitable for operating the actuator 121. A pressurized accumulator 131 provides a reservoir for the hydraulic fluid. This reservoir is connected through respective check valves 132 and 133 to both sides of the pump 127. Pump 127 is preferably of the positive displacement, meshing gear type and is driven in either direction by an electric motor 135 whose speed can be varied from zero to a preselected maximum by means of suitable control electronics. Movement of the piston may be tracked by a suitable transducer; e.g., a slide wire potentiometer so as to provide a suitable feedback voltage or signal for controlling the energization of the motor. The system of FIG. 2 also employs two control valves 139 and 141 of the type shown in FIG. 1.
One side of the pump 127, e.g. the left side as shown in FIG. 2, is connected to one side of the cylinder 121, (e.g. the right side) through a hydraulic circuit which includes the source/source-drain path of control valve 139 and the load drain/load path of the second flow matching valve 141. The other side of the pump 127 is symmetrically connected through a hydraulic circuit which includes the source/source-drain path of the flow matching valve 141 and the load drain/load path of the flow matching valve 139. Both flow matching valves 139 and 141 are identical in construction and size.
The load-drain port of each of the control valves 139 and 141 is also cross connected, for discharge, to the source drain port 33 of the other control valve. While the theory of operation of the overall hydraulic system is subject to differing interpretations and explanations, the following is submitted as useful in understanding its operation. In the description of operation, it is assumed that load is being applied to the piston 123 so that the right side of the cylinder is under greater pressure than the left side.
In order to drive the piston against the load, the pump 127 is driven so as to produce a flow to the left as seen in the drawing of FIG. 2. When the pressure at the outlet of the pump exceeds that on the high pressure side of the actuator 121, the valving elements in the left hand control valve 139 will be raised until the source port 23 is opened to the source drain port 23. The poppet valve 17 and the throttling valve (grooves 27 and 31) will also have been opened. Thus, during operation in this direction, the valve 139 is essentially open and has no control effect, i.e. it is "passive".
Hydraulic fluid flow proceeding from the left hand source drain port into the load drain port 26 of the right hand control valve 141 will lift its valving elements also by virtue of the force exerted on the underside of the poppet element 17. This high pressure flow will then proceed out the load port 24 and into the high pressure (right hand) side of the actuator.
Since the poppet valve portion of the left hand control valve 139 will have been opened as described previously, hydraulic fluid from the low pressure side of the actuator 121 can drain through the upper portion of control valve 139 and into the throttling port 28 of the right hand control valve 141, this port having been opened through to the groove 31 by the lifting of the valve elements by the flow past the poppet element 17. While the source drain port 33 may still be closed, the return flow can exit, past the ball check valve 37, to the source port 23 and then back to the pump on its (current) intake or suction side.
When the pump 127 is operated in the opposite direction, i.e. producing flow to the right as seen in FIG. 2, an essentially similar operation takes place but additional flow matching or throttling effects come into play. Again, the pump output pressure must reach a level at least equal to that on the high pressure side of the cylinder in order to lift the valving elements of the right hand control valve 141 against the pressure exerted on the top of the poppet element 17 since this pressure is transmitted, through the stem 21, to the spool valve element 19. In this direction of operation, the right hand valve is the "passive" one of the two. Once the source drain port 33 has been opened, flow can proceed into the load drain port 26 of the left hand control valve 139 where it will cause the poppet valve element 17 to lift somewhat and then proceed into the low pressure side of the actuator 121.
Since the poppet valve 17 on the right hand control valve 141 will have been raised, high pressure flow can proceed past the poppet valve and out the load drain port 26 of control valve 141.
However, since the flow out of the source drain port 33 from the right hand control valve 141 past the poppet valve element 17 of the left hand control valve will not be sufficient to fully open the respective source drain port 33, venting flow from the high pressure side must take place through the throttling port 28. Further, since the extent of opening between the cooperating grooves 27 and 31 in the valve 139 depends upon the amount of flow past the poppet element 17, it will be understood that a throttling operation will take place which will tend to match the venting flow from the high pressure side of the actuator 121 to the filling flow coming in to its low pressure side. It is an aspect of the present invention that the main pressure drop, i.e. down to pressure at the inlet or suction side of the pump, occurs at the spool valve opening between grooves 27 and 31. As will be understood by those skilled in the art, this pressure drop is developed without exerting force tending to displace the spool valve element along its axis, i.e. vertically as illustrated. The throttling action prevents whatever load may be present on the hydraulic actuator 121 from overrunning the motor driving pump 127. Accordingly, the operation of the system in the two directions tends to be matched. Further, when the motor driving the pump 127 is stopped, the two poppet valve elements will close in rapid succession effective freezing the piston in position. Any residual motor energy will flow back through the gear pump and back to the intake of the pump. Once stopped, the pump and its driving motor are unloaded.
Since the hydraulic circuit is entirely symmetrical, it can be seen that complementary actions are obtained if the load is applied to the piston in the opposite direction. In other words, the high pressure and low pressure sides of the cylinder are only dictated by the direction of the load vector. Conversely, the response or sensitivity of the actuator is identical in both directions regardless of the direction of the load, a highly desirable attribute as will be understood by those skilled in the servo control art.
In view of the foregoing it may be seen that several objects of the present invention are achieved and other advantageous results have been attained.
As various changes could be made in the above constructions without departing from the scope of the invention, it should be understood that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | 4y
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TECHNICAL FIELD
[0001] The present invention relates to the use of an organic matrix material for producing an organic semiconductor material, and also to an organic semiconductor material comprising an organic matrix material and an organic dopant, and also to an electronic component.
BACKGROUND OF THE INVENTION
[0002] It is known that doping can alter organic semiconductors with regard to their electrical properties, in particular their electrical conductivity, as is also the case for inorganic semiconductors such as silicon semiconductors.
[0003] In this case, generation of charge carriers in a matrix material increases the initially quite low conductivity and, depending on the type of the dopant used, achieves a change in the Fermi level of the semiconductor. Doping leads to an increase in the conductivity of the charge transport layer, which reduces resistance losses, and leads to an improved transition of the charge carriers between contacts and organic layer.
[0004] For the doping of such organic semiconductors, strong electron acceptors such as tetracyanoquinonedimethane (TCNQ) or 2,3,5,6-tetrafluorotetracyano-1,4-benzoquinone-dimethane (F4-TCNQ) have become known; see M. Pfeiffer, A. Beyer, T. Fritz, K. Leo, Appl. Phys. Lett., 73 (22), 3202-3204 (1998) and J. Blochwitz, M. Pfeiffer, T. Fritz, K. Leo, Appl. Phys. Lett., 73 (6), 729-732 (1998). As a result of electron transfer processes in electron donor-like base materials (hole transport materials), these generate what are known as holes, the number and mobility of which more or less significantly alter the conductivity of the matrix material.
[0005] Known matrix materials are, for example, starburst compounds such as 4,4′,4″-tris(diphenylamino)triphenylamine (TDATA), 4,4′,4″-tris(3-methylphenylphenylamino)-triphenylamine (m-MTDATA) and N,N,N′,N′-tetrakis(4-methoxyphenyl)benzidine (MeO-TPD).
[0006] The chemical structure of the abovementioned known matrix materials is shown below.
m-MTDATA TDATA MeO-TPD
[0007] However, these compounds are thermally unstable, i.e. they have a low glass transition temperature and tend to crystallization at low temperatures, which leads ultimately to unstable electronic components.
[0008] The glass transition temperature is regarded as being the temperature at which motion of the molecules in the event of rapid cooling of the material from the melt is no longer possible for kinetic reasons, and thermodynamic parameters such as the heat capacity or the coefficient of expansion suddenly change from typical liquid values to typical solid values. The thermal stability of the matrix material is of significance especially for morphological reasons when organic semiconductor materials are used with such matrix materials, in order to prevent the formation of roughness at elevated operating temperatures in the customary layer structure of such semiconductor materials. Furthermore, the thermal stability is of significance, in order to restrict the diffusion of the dopant within the matrix material.
[0009] The prior art also discloses thermally stable matrix materials such as 2,2′,7,7′-tetrakis(N,N-diphenylamino)-9,9′-spirobifluorene (spiro-TAD) which, however, owing to the position of the energy level of their highest occupied molecular orbitals (HOMOs), cannot be doped.
SUMMARY OF THE INVENTION
[0010] It is an object of the invention to provide for use of an organic matrix material for producing an organic semiconductor material, the matrix material being thermally stable and dopable, in order to provide hole transport layers having high hole conductivity for use in organic semiconductor components. Furthermore, it should be possible to apply the organic matrix materials by vapour deposition in order to provide layers having a correspondingly high hole conductivity by coevaporation under reduced pressure with a strong organic electron acceptor.
[0011] This object is achieved by the organic matrix material being comprised at least partly of a spirobifluorene compound of the formula (I)
[0012] where R is at least one substituent on a phenyl radical, but not all of R are simultaneously hydrogens,
[0013] and/or of the formula (II)
[0014] where R is a substituent apart from hydrogen and R′ is a substituent,
[0015] the glass transition temperature of the organic matrix material being at least 120° C. and the highest occupied molecular orbital (HOMO) of the matrix material lying at a maximum energy level of 5.4 eV. In formula (I), a phenyl radical may thus be provided with one or more substituents.
[0016] It is preferred that each R and/or R′ in formula (I) and (II) is independently selected from the group consisting of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, NH 2 , N(CH 4 ) 2 and NPh 2 , where not all R in formula (I) are simultaneously hydrogens.
[0017] It is particularly preferred that the spirobifluorene compound is selected from the group consisting of
[0018] It is likewise preferred that the glass transition temperature of the spirobifluorene compound lies between 120° C. and 250° C., and the highest occupied molecular orbital of the compound lies at an energy level between 4.5 eV and 5.4 eV, preferably between 4.8 eV and 5.2 eV.
[0019] The object is also achieved by an organic semiconductor material comprising an organic matrix material and an organic dopant, the organic matrix material at least partly comprising one or more compounds which are used as matrix materials in accordance with the invention.
[0020] It is likewise preferred that the dopant is 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane or a derivative thereof. However, further dopants having similar acceptor action and equal or larger molecular mass are possible; see, for example, DE10357044.6. It is particularly preferred that the molar doping ratio of dopant to matrix material is between 1:1 and 1:10 000.
[0021] The object is further achieved by an electronic component in which an organic matrix material is used which is comprised at least partly of a spirobifluorene compound which is envisaged as a matrix material in accordance with the invention.
[0022] Finally provided is the electronic component in the form of an organic light-emitting diode (OLED), a photovoltaic cell, an organic solar cell, an organic diode or an organic field-effect transistor.
[0023] The invention is based on the surprising finding that use of the organic matrix material described for producing an organic semiconductor material affords thermally stable and doped hole transport layers for use in organic semiconductor components. The use of the matrix materials provides bole transport materials which can be applied by vapour deposition, so that they lead, by coevaporation under reduced pressure with a strong organic electronic acceptor, to layers having a high hole conductivity.
[0024] When the organic matrix materials described are used, a stable, singly positively charged cationic state of the hole transport material is achieved.
[0025] Further advantages and features of the present invention are evident from the detailed description of exemplary organic matrix materials which follows, and also the appended drawings, in which
BRIEF DESCRIPTION OF DRAWINGS
[0026] FIG. 1 shows the dependence of the lateral current on the layer thickness for a transport layer of the organic matrix material spiro-TTB (doped with F4-TCNQ);
[0027] FIG. 2 shows the dependence of the lateral current on the layer thickness for a transport layer of the organic matrix material spiro-iPr-TAD (doped with F4-TCNQ); and
[0028] FIG. 3 shows the luminance voltage and power efficiency voltage characteristics of an organic light-emitting diode having doped transport layers and spiro-TFB (doped with F4 TCNQ) as a p-dopant.
DETAILED DESCRIPTION OF EMBODIMENTS
EXAMPLES
A. Preparation of 2,2′,7,7′-tetrakis(N,N-di-p-methylphenylamino)-9,9′-spirobifluorene (spiro-TTB)
[0029]
[0030] 2,2′,7,7′-Tetrabromo-9,9′-spirobifluorene (10 g, 15.8 mmol), di-p-tolylamine (14.2 g, 72.1 mmol) and sodium tert-butoxide (9.6 g, 100 mmol) are stirred in 100 ml of anhydrous toluene under nitrogen at 60° C. for 1 h. Subsequently, tri-tert-butylphosphine. (200 mg, 1.0 mmol, 6.3% based on tetrabromospitobifluorene) and palladium(II) acetate (92 mg, 0.4 mmol, 2.6% based on tetrabromospirobifluorene) are added and the reaction mixture is heated to reflux under nitrogen. The progress of the reaction is monitored by thin-layer chromatography (eluent: 50% hexane in dicchloromethane). After 2.5 h, no reactant can any longer be detected in the TLC. The reaction mixture is cooled, admixed with a solution of 100 mg of KCN in 20 ml of water and stirred at 60° C. for another 1 h. After cooling to room temperature, the phases are separated, and the organic phase is dried over sodium sulphate and the solvent is removed. The crude product is recrystallized twice from dioxane and subsequently reprecipitated from a little dichloromethane in hexane and dried under reduced pressure.
[0031] Yield: 15.0 g (13.8 mmol, 87% of theory) of slightly greenish powder.
[0032] 1 H NMR (500 MHz, CDCl 3 +hydrazine hydrate): 7.40 (d, 1H, J=7.8), 7.00 (d, 4H, J=8.3), 6.88 (d, 4H, J=8.3), 6.85 (dd, 1H, J=8.3, J=2.0), 6.67 (d, 1H, J=2.0), 2.30 (s, 6H).
[0033] 13 C NMR (127.5 MHz, CDCl 3 +hydrazine hydrate): 149.8, 146.7, 145.3, 136.1, 131.5, 129.5, 124.0, 123.2, 119.9, 119.3, 65.3, 20.6.
B. Preparation of 2,2′,7,7′-tetrakis(N,N-di-pisupropylphenylamino)-9,9′-spirofluorene (spiro-iPr-TAD)
4-Isopropyliodobenzene
[0034]
[0035] 4-Isopropylaniline (49.5 g, 366 mmol) is suspended in 200 ml of dist. water and admixed gradually under ice cooling with 200 ml of semiconcentrated sulphuric acid. Subsequently, a solution of sodium nitrite (25.5 g, 370 mmol) in 200 ml dist. water is added dropwise at such a rate that the temperature does not rise above 20° C. On completion of the dropwise addition, the mixture is stirred at 2° C. for another 20 min. The resulting clear reddish diazonium salt solution is now added through a filter to a solution of potassium iodide (135.0 g, 813 mmol) in 200 ml of dist. water. The reaction mixture is stirred at 80° C. for 1 h. In the course of this, the solution becomes black with vigorous gas evolution and an oily organic phase separates out. After cooling, the organic phase is removed and the aqueous phase is extracted four times more with 100 ml of ether. The combined organic phases are washed with dilute sodium hydroxide solution and dist. water, and dried over sodium sulphate. After the solvent has been removed, the crude product is distilled in a membrane-pump vacuum. The slightly reddish target product distils over at a temperature of 100-105° C. (15 mbar).
[0036] Yield; 75.3 g (310 mmol, 83% of theory) of slightly reddish liquid.
[0037] 1 H NMR (500 MHz, CDCl 3 ): 7.60 (d, 2H, J=8.3), 6.98 (d, 2H, J=8.3), 2.85 (q, 1H, J=6.8, 1.22 (d, 6H, J=6.8).
[0038] 13 C NMR (127.5 MHz, CDCl 3 ): 148.4, 137.3, 128.6, 90.6, 33.7, 23.8.
N-Acetyl-4-isopropylaniline
[0039]
[0040] Acetic anhydride (26.0 g, 254 mmol) is slowly added dropwise to a solution of 4-isopropylaniline (17.2 g, 127 mmol) in 80 ml of chloroform. In the course of this, intense heating of the reaction mixture occurs. On completion of the dropwise addition, the mixture is stirred at room temperature for another 2 h. The reaction mixture is concentrated to dryness and the resulting, reddish-white solid is recrystallized from hexane.
[0041] Yield: 21.1 g (120 mmol, 94% of theory) of white solid.
[0042] 1 H NMR (500 MHz, CDCl 3 ): 7.88 (s, 1H), 7.40 (d, 2H, J=8.3), 7.14 (d, 2H, J=8.3), 2.86 (q, 1H, J=6.8), 1.21 (d, 6H, J=6.8).
[0043] 13 C NMR (127.5 MHz, CDCl 3 ): 168.6, 144.9, 135.6, 126.7, 120.2, 33.5, 24.3, 23.9.
[0044] Melting point: 107° C. (literature (Dyall, Aus. J. Chem. 17, 1964, 419): 104-105° C.).
N-Acetyl-N,N-di(4-isopropylphenyl)amine
[0045]
[0046] 4-Isopropyliodobenzene (29.2 g, 118 mmol), N-acetyl-4-isopropylaniline (21.0 g, 118 mmol), copper powder (15.0 g, 237 mmol), potassium carbonate (65.4 g, 474 mmol) and 18-crown-6 (2.9 g, 12 mmol) are heated to reflux in 200 ml of 1,2-dichlorobenzene. The reaction is monitored by thin-layer chromatography (eluent: 10% THF in dichloromethane). After 48 h, the still-hot reaction mixture is filtered, the filter residue is washed thoroughly and the solvent is removed on a rotary evaporator. The crude product is chromatographed on silica gel using 10% THF in dichloromethane. The product fractions are concentrated to dryness, recrystallized from hexane and dried under reduced pressure.
[0047] Yield: 14.31 g (48 mmol, 41% of theory) of slightly brovish solid.
[0048] 1 H NMR (500 MHz, CDCl 3 ): 7.21 (m, 8H), 2.90 (s (br.), 2H), 2.04 (s, 3H), 1.23 (s(br.), 12H).
N,N-Di-(4-isopropylphenyl)amine
[0049]
[0050] N-Acetyl-N,N-di(4-isopropylphenyl)amine (5.4 g, 18.4 mmol) are heated to reflux in 100 ml of 20% aqueous ethanol. The reaction is monitored by thin-layer chromatography. After 30 h, no reactant is any longer detectable in the TLC. The ethanolic solution is poured into dist. water, and the brownish precipitate is filtered off with suction, dissolved in dichloromethane and dried with sodium sulphate. The solution is concentrated and chromatographed through a short silica gel column with 50% dichloromethane in hexane. The product fractions are concentrated to dryness and the product is dried under reduced pressure.
[0051] Yield: 4.0 g (16 mmol, 86% of theory) of slightly brownish solid.
[0052] 1 H NMR (500 MHz, CDCl 3 ): 7.12 (d, 4H, J=8.3), 6.99 (d, 4H, J=8.3), 5.55 (s(br.), 1H), 2.86 (q, 2H, J=6.8), 1.24 (d, 12H, J=6.8).
[0053] 13 C NMR (127.5 MHz, CDCl 3 ): 141.3, 127.1, 117.7, 33.4, 24.1.
2,2′,7,7′-Tetrakis(N,N-di-p-isopropylphenylamino)-9,9′-spirobifluorene (spiro-iPr-TAD)
[0054]
[0055] 2,2′,7,7′-Tetrabromo-9,9′-spirobifluorene (1.7 g, 2.6 mmol), N,N-di-4-isopropylphenylamine (3.0 g, 12.0 mmol) and sodium tert-butoxide (1.6 g, 17 mmol) are stirred in 100 ml of anhydrous toluene under nitrogen at 60° C. for 1 h. Subsequently, tri-tert-butylphosphine (4.8 mg, 0.24 mmol, 9.2% based on tetrabromospirobifluorene) and palladium(II) acetate (27 mg, 0.12 mmol, 4.6% based on tetrabromospirobifluoreie) are added and the reaction mixture is heated to reflux under nitrogen. The progress of the reaction is monitored by thin-layer chromatography (eluent: 20% dichloromtethane in hexane). After 3.5 h, no reactants can any longer be detected in the TLC. The reaction mixture is cooled, admixed with a solution of 100 mg of KCN in 20 ml of water, and stirred at 60° C. for another 1 h. After cooling to room temperature, the phases are separated, and the organic phase is dried over sodium sulphate and the solvent is removed. The crude product is recrystallized twice from dioxane and subsequently dried under reduced pressure.
[0056] Yield: 2.8 g (2.1 mmol, 81% of theory) of slightly yellowish, finely crystalline powder.
[0057] 1 H NMR (500 MHz, CDCl 3 ): 7.41 (d, 1H, J=8.3), 7.05 (d, 4H, J=8.3), 6.90 (m, 5H). 6.72 (s (br.) 1H), 2.85 (q, 2H, J=6.8), 1.24 (d, 12H, J=6.8).
[0058] 13 C NMR (127.5 MHz, CDCl 3 ): 150.7, 147.5, 146.3, 143.3, 137.2, 127.6, 125.3, 123.8, 120.8, 120.7, 66.2, 34.1, 24.8.
[0059] Tg: 144° C., Tk: 166° C., Tm: 363° C.
[0060] The two organic materials spiro-TTB and spiro-iPr-TAD were each doped with F4-TCNQ and tested in conductivity measurements. For these measurements, the doped layer was applied by coevaporation under reduced pressure over two approx. 5 mm-wide contacts (made of indium tin oxide, ITO) which, were applied to a glass substrate at a distance of 1 mm from one another. The contacts were connected externally to a current-voltage measuring instrument, which allowed the lateral current to be measured at a fixed applied voltage. From this lateral current, the conductivity of the layer is then calculated by a simple resistance relationship. The conductivity can be determined with the aid of the following equation:
Conductivity=(lateral current*distance)/(width*layer thickness)
[0061] FIGS. 1 and 2 each show the increase in the lateral current with the layer thickness for the two doped matrix materials. The conductivity of a 50 nm-thick layer of spiro-TTB doped with 2.5% F4-TCNQ is approx. 1.6 E-5 S/cm, while the conductivity of a 50 nm-thick layer of spiro-iPr-TAD doped with 5% F4-TCNQ is approx. 8 E-7 S/cm.
[0062] One embodiment of an inventive electronic component in the form of an OLED with an organic matrix material, as is to be used in accordance with the invention, can be produced and comprises, in the case of normal design emitting through the substrate, the following layer arrangement:
1. carrier substrate: glass, 2. bottom electrode (anode A): ITO, 3. p-doped, hole-injecting and -transporting layer: spiro-TTB: F4TCNQ (2.5% molar doping concentration), 4. thin bole-side intermediate layer of a material whose band positions match the band positions of the layers surrounding them: spiro-TAD, 5. light-emitting layer (possibly doped with emitter dye): TCTA (4,4′,4″-tris(N-carbazolyl)triphenylamine): Irppy 3 (fac-tris(2-phenylpyridine)iridium), 6. thin electron-side intermediate layer of a material whose band positions match the band positions of the layers surrounding them: BPhen (4,7-diphenyl-1,10-phenanthroline), 7. n-doped, electron-injecting and -transporting layer BPhen doped with caesium (approx. 1:1 molar concentration), 8. top electrode (cathode K): aluminum, and 9. encapsulation for exclusion of environmental influences: covering glass
[0072] A thus produced organic light-emitting diode was examined with regard to the luminance voltage and current efficiency voltage characteristics, the results of which are shown in FIG. 3 . Due to the doping of the organic hole transport layer, his exhibits a very steep current-voltage characteristics and thus a very steep luminance voltage characteristics (left-hand axis). The luminance of 100 cd/m 2 and 1000 cd/m 2 are attained at voltages of 2.75 V and 3.1 V. Owing to the ideal arrangement of the doped hole and electron transport layers and of the two intermediate layers, the current efficiencies of light generation are likewise very high and constant over a wide brightness range: 46 cd/A and 45 cd/A. Owing to the stable hole transport layer, this OLED can be operated stably at relatively high temperatures (up to above 100° C.) without a reduction in the optoelectronic properties.
[0073] Features of the invention disclosed in the above description, in the claims and in the drawings may be essential either individually or in any combination for the realization of the invention in its different embodiments. | 4y
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CROSS REFERENCES TO RELATED APPLICATIONS
[0001] This application is a U.S. National Stage application of International application PCT/FI03/00090, which was filed on Feb. 5, 2003, and claims priority on Finnish Application No. 20020258, which was filed on Feb. 7, 2002.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] Pre-tensionable bolts are previously known, which can be provided with a strain by means of a pressurized medium chamber arranged at one end of the bolt, after which it is possible to tighten a tightening member at the opposite end of the bolt. Such arrangements, for example, in connection with bolts intended for joining two elements, are presented e.g. in GB patent 1 382 192 and in DE publication 24 58 810. This latter publication also presents a traction means which is screwed around one end of a fixing means and comprises two parts, between which there is a space where pressurized medium is introduced and which traction means is, in the final joint, replaced with an ordinary nut.
[0004] Pre-tensioning arrangements of prior art have required a particular chamber structure which is screwed or joined by a quick coupling at the end of an elongated fixing means, such as a bolt. To perform the pre-tensioning, an axial bore is also needed inside the bolt as well as a power-transmitting rod placed therein, whose end forms a piston of the pressurized medium chamber which is acted upon to provide the pre-tensioning.
[0005] A simpler arrangement for providing the strain required by the pre-tensioning in an elongated fixing means for joining two elements is presented in the publication GB 2267944. This document discloses a tightening member, a “hydraulic nut”, which, on one hand, is fixed at the end of the elongated fixing means, provided with an outer threading, by means of a corresponding inner threading, and, on the other hand, abuts at its front surface on the surface of the first element to be joined. The tightening member is formed of three parts in such a way that the first part is fixed to the fixing means in a way transmitting power in the longitudinal direction, and the second part abuts at its front surface on one of the elements to be joined. The pressure of the pressurized medium can be introduced between the first and the second parts. The pressure is used to make the parts move farther away from each other, wherein the fixing means is stretched. The parts can be locked in this position by means of a third part which is effective therebetween and which is transferred to a locking position, after which the pressure can be removed.
[0006] In the arrangement presented in the publication, the second part which abuts the element to be joined, is locked to be axially immobile in relation to the first part by means of an annular locking part which is screwed by screw threads around the first part and which abuts, by its front surface facing the element to be joined, on the second part. The second part is thus placed underneath the first part and the locking part, joined together. So that the diameter of the tightening member could be reduced from the arrangement of prior art as presented in FIG. 1 of the GB document, the inner wall of the pressurized medium chamber in the first part is made thin and flexible elastically by the effect of the pressure in the chamber against the outer surface of the elongated fixing means.
[0007] Although the outer surface of the fixing means, according to the document, supports the inner wall against any further deflection caused by problems of tightness, this thinner inner wall is, however, the weak point in the structure and a potential cause of problems in the tightness for the pressurized medium.
SUMMARY OF THE INVENTION
[0008] It is an aim of the invention to present a novel arrangement in which the diameter of the hydraulic nut can be reduced without potential weak points in view of the tightness of the pressurized medium chamber. To attain this purpose, the tightening member according to the invention is primarily characterized in what will be presented in the characterizing part of the appended claim 1 .
[0009] In the invention, it is possible to achieve, by the method known from the publication GB 2267944, a strain in the fixing means with the same tightening member by which the joint between the two parts is tightened. There is no need for separate pre-tensioning devices or parts to be removed after pre-tensioning. Because the locking part is placed around the second part and underneath the first part (when the first end of the tightening member is considered to be “up”), the whole diameter of the tightening member can still be kept small, without a need to form the inner wall of the pressurized medium chamber thin, which is the result if the recess forming the pressurized medium chamber were transferred close to the fixing means in the radial direction so that the locking part with a reasonable diameter could be placed around the first part.
[0010] In the following, the invention will be described in more detail with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 shows a first embodiment of the invention in a longitudinal sectional view of the fixing means.
[0012] FIG. 2 shows a second embodiment of the invention in a longitudinal sectional view of the fixing means.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] FIG. 1 shows a fixing means 1 , which is inserted through two elements to be joined together, for example through bores made in the elements. The fixing means can be an ordinary stud bolt equipped with an outer thread, or the like. FIG. 1 shows the first element 6 to be joined and the second element 7 to be joined, and a joint plane 8 therebetween, through which the fixing means 1 is inserted. The elements 6 , 7 can be joined together, for example, at their flange-like protrusions, through which the bores have been made. The elements may be some machine parts. At the opposite end of the fixing means 1 , there is a part which abuts the second element to be joined and which at that point fixes the fixing means to be immobile in its longitudinal direction. This part, which may be an ordinary nut or a protrusion integrated in the fixing means, is not shown in more detail.
[0014] The tensioning means 2 screwed around the fixing means 1 , close to its outermost end, comprises a first part A which is connected around the first end of the fixing means 1 . This part can be connected to the outer thread 15 of the fixing means 1 by means of a suitable inner thread 16 , and it can be moved by screwing in the axial direction. When the first part has been moved to a given position, it is capable of transmitting tensions in the axial direction to the fixing means 1 , being immovable in relation to it in the axial direction, when subjected to a force effective in the longitudinal direction of the fixing means. The position of the first part A in the axial direction of the fixing means 1 can be changed only by rotating it on the outer thread 15 of the fixing means, i.e. by “screwing”.
[0015] In addition, the tightening member 2 comprises a second part B which is separated from the fixing means 1 , in an annular manner around it, between the first part A and the element 6 . In this part B, there is an annular front surface 3 facing towards the second end of the fixing means 1 , this surface abutting the first element 6 to be joined at a pressure determined by the tightening force. The front surface 3 is not necessarily directly laid against the first element 6 to be joined, but a washer or a corresponding piece can be provided between the front surface and the element. The front surface 3 is also in this case against the element 6 in the functional sense, because the washer, or the like, can be considered to be part of the element 6 .
[0016] The first part A and the second part B may move in relation to each other in the axial (longitudinal) direction of the fixing means 1 . The first part A and the second part B are shaped and placed in connection with each other in such a way that a pressurized medium chamber D is formed therebetween, having a volume dependent on said movement. FIG. 1 shows, on the left hand side, a situation in which the tightening member 2 is untightened, that is, the joint is “open”. On the right hand side, the figure shows a situation in which pressure has been introduced into the pressurized medium chamber D via a channel 4 extending through the first part A into the pressurized medium chamber D in the axial direction; and as a result, the first part A is moved farther away from the second part B and, correspondingly, from the element 6 to be joined, on whose surface the second part B abuts at its front surface 3 either directly or indirectly. Because the first part A is screwed to be axially immovable around the end of the fixing means 1 , the fixing means 1 is stretched. The substance to be introduced in the pressurized medium chamber D along the channel 4 may be a liquid, whose pressure can be used to make the first part and the second part move in the axial direction in relation to each other.
[0017] The first part A and the second part B are locked in the position shown on the right hand side in the figure by means of a third part, locking part C, effective therebetween. The locking part is placed axially immovably on the second part B, and it abuts, at its front surface 9 transverse to the axial direction, on the first part A, obstructing the movement of the part A in the axial direction by this front surface. In FIG. 1 , this is implemented in such a way that the outer surface of the second part B is provided with an outer thread 10 , on which the annular locking part C is screwed by its inner thread 11 . Thanks to the matching screw threads 10 , 11 , the locking part can be screwed in the axial direction so that it abuts the front surface 12 of the first part A. After the locking part C has been screwed in contact with the front surface 12 of the first part A, the pressure can be removed from the pressurized medium chamber D, because the locking part C will remain in its position into which it has been transferred by screwing and will prevent the return movement of the first part A. The fixing means 1 will thus remain in a permanently stretched state and the joint will remain permanently tightened.
[0018] In FIG. 1 , the first part A is closer to the outermost end of the fixing means 1 , and the end of the second part B facing this outermost end of the fixing means is placed in an annular recess formed in the first part A, opening in the opposite direction towards the element 6 to be joined and towards the second end of the fixing means 1 . The above-mentioned pressurized medium chamber D is formed between the bottom 14 of this annular recess and the front surface 13 of the end of the second part B. The axially outermost rim face of the collar-like outer wall of the recess forms the front surface 12 to come into abutment with the front surface 9 of the locking part C in the first part A. The locking part C is thus placed, in the axial direction, i.e. in the longitudinal direction of the fixing means 1 , in the area between the first part A and the element 6 to be joined. The outer diameter of the periphery of the second part B, to which the locking part C is fixed, is dimensioned smaller than the outer diameter of the first part A, so that the locking part C, which comes around the second part, would not increase the outer diameter of the tightening member too much. The cylindrical outer surface of the locking part C may form an extension of the cylindrical outer surface of the part A in the direction of the element 6 ; that is, the diameters are equal. Futhermore, FIG. 1 shows that the second part B is narrowed inwards at its butt end, i.e. in the part on the side of the front surface 3 , in which recess the annular locking part C is placed in such a way that the outer periphery of the locking part C will be approximately flush with the outer periphery of the first part A.
[0019] The pressurized medium chamber D can be sealed at its outer periphery and inner periphery (at the outer wall and inner wall of the recess) by means of annularly placed seals indicated with references 5 in FIG. 1 . The seals 5 are placed in the second part B far from the opening of the recess of the first part A and closer to that front surface 13 of the end of the second part B which limits the pressurized medium chamber D. In general, the seals 5 can be placed in such a way that in the minimum volume position of the chamber D they are on the sliding surfaces farther away in the sliding direction from that end surface which would, if the chamber expanded too much, move past the seal, and closer to the end surface of that part to which they are connected. The distance from the seal 5 is greater to the end surface of the part moving in relation to the same than to the end surface of the part comprising the seal. If the seals 5 are fixed to the first part A, to the walls of the recess, they are thus closer to the front surface 12 of the part A.
[0020] As seen from FIG. 1 , in the recess which forms the pressurized medium space D and to which the second part B is fitted in an axially slidable manner, the wall on the side of the fixing means 1 , i.e. the inner wall, is placed against the outer surface of the fixing means 1 ; that is, it cannot bend inwards in the radial direction. The first part A is, on that section which is between the bottom of the recess and the opening of the recess at the level of the front surface 9 , provided with an inner thread in the inner wall, that is, the inner thread 16 of the first part A extends, in the axial direction, also to the area of the recess, in which area the first part is screwed onto the outer thread 15 of the fixing means 1 .
[0021] FIG. 2 shows an embodiment modified from the embodiment of FIG. 1 , wherein the first part A is a part integrated in the fixing means 1 , that is, it cannot be moved in relation to the fixing means in its axial direction. Compared with FIG. 1 , the threaded joint between the fixing means 1 and the first part A is now replaced with a permanent connection, and the part A can be of the same piece as the fixing means 1 , i.e., in a way, it forms the head of the bolt. In other respects, the shape and position of the part A in relation to the parts B and C, the shapes of the parts B and C, and the operating principle of all the three parts in the tightening and locking are quite the same as in FIG. 1 , only with the exception that the position of the first part A before the tightening and locking is determined by the position of the whole fixing means 1 . | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority and herein incorporates by reference U.S. provisional patent application 61/242,057, filed Sep. 14, 2009.
BACKGROUND OF THE INVENTION
[0002] Throughout the world, bicycle production and use still outnumbers automobile production and use almost two to one. Bicycles have the advantage of not requiring fuel or at least very little for the powered versions compared to automobiles. Additionally, maintenance is much more accessible and allows even relatively poor users to keep their bicycle operational.
[0003] Of course some of the advantages of bicycle are also a detriment to their use. They require much more human effort to use and they are less comfortable in general than some other forms of transportation. Additionally, bicycles are inherently unstable unless in motion. Tricycles use three wheels and obviate this problem by stabilizing the tricycle without relying on gyroscopic principles. Tricycles generally provide more space to carry things and for more comfortable seating than most bicycles.
[0004] Tricycles gain stability at the expense of steering control because unlike a bicycle which leans in a turn, tricycles generally rely on turning the front wheel which is less maneuverable.
[0005] There is a need for a stable tricycle that provides maneuverability, ease of use and economy in operating costs that overcomes the shortcomings of the prior art.
SUMMARY OF THE INVENTION
[0006] An energy efficient tricycle has a frame, fork and handlebars connected to hold a front wheel and two rear wheels. A power and transmission assembly means is mounted on the frame to provide power to both rear wheels. A pair of pedals are independently operable and used to provide the torque needed to propel the tricycle. A motorized embodiment is also provided to provide additional power when needed or to completely motorize the tricycle. The pedals are mounted so that they travel in a vertical path. The handlebars, front wheel and both rear wheels are foldable to allow the tricycle to fit within a vehicle. The tricycle has a very low center of gravity. A seat is provided in one embodiment to allow a user to sit and operate using a motor.
[0007] Other features and advantages of the instant invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a side view of an energy efficient tricycle according to an embodiment of the invention.
[0009] FIG. 2 is a front view of the energy efficient tricycle shown in FIG. 1 .
[0010] FIG. 3 is back view of the energy efficient tricycle shown in FIG. 1 .
[0011] FIG. 4 is a top view of the energy efficient tricycle shown in FIG. 1 .
[0012] FIG. 5 is a top view showing the front wheel in a folded position of the of the energy efficient tricycle shown in FIG. 1 .
[0013] FIG. 6 is a side view showing the steering tube in a folded position of the energy efficient tricycle shown in FIG. 1 .
[0014] FIG. 7 is a side view showing the steering tube and front wheel in the folded position.
[0015] FIG. 8 is a side view showing the steering tube, front wheel and both rear wheels in the folded position.
[0016] FIG. 9 is an energy efficient tricycle having a seat according to an embodiment of the invention.
[0017] FIG. 10 is an energy efficient tricycle having a battery.
[0018] FIG. 11 is an energy efficient tricycle having a motor.
[0019] FIG. 12 is a top view of the energy efficient tricycle shown in FIG. 10 .
[0020] FIG. 13 is a detailed cut-away view of a portion of the energy efficient tricycle shown in FIG. 1 .
[0021] FIG. 14 is a cut-away view of the transmission of the energy efficient tricycle shown in FIG. 10 .
DETAILED DESCRIPTION OF THE INVENTION
[0022] In the following detailed description of the invention, reference is made to the drawings in which reference numerals refer to like elements, and which are intended to show by way of illustration specific embodiments in which the invention may be practiced. It is understood that other embodiments may be utilized and that structural changes may be made without departing from the scope and spirit of the invention.
[0023] Referring to FIGS. 1 through 4 , an energy efficient tricycle 100 is shown having a frame 120 . Frame 120 is lightweight and strong. It is made of a high carbon steel such as chromoly, aluminum or even a carbon fiber composite as long as the frame remains strong yet flexible. A handlebar 115 telescopically fits within a steering tube 144 . A clamp 106 selectively secures handlebars within steering tube 144 . A front wheel 114 is secured with fork 148 which is rotatably attached to steering tube 144 .
[0024] A front axle 124 is attached to fork 148 and allows wheel 114 to roll. A front hand brake 154 is provided to control front wheel 114 . Handlebar 115 has two handgrips 102 and hand brakes 104 . Brake cables 110 and 112 are secured using brake ties 108 . In order to allow tricycle 100 to be easily transported and stored, a handlebar folding hinge 116 is provided and will be discussed in detail later. A rotating hinge lock 146 is provided to lock steering tube 144 in place during use and then to easily move into a storage position. A front wheel rotating hinge 118 is provided for folding as well. Two foot pedals 122 are provided to allow a user to apply a locomotive force. Each pedal 122 is independently operable and need not be in any special position to operate.
[0025] A cover 126 is provided to cover and protect the transmission, electronics and battery if so equipped. The downward force from pedals 122 is transmitted to the rear wheels 140 using a main drive chain 128 . Of course, a belt or other force transmitting mechanism could be used as long as the downward force is able to be turned into a torque to turn the wheels 140 . Two rear drive sprockets—one on each side 130 are provided to transmit the torque to the wheels 140 . In operation, energy efficient tricycle 100 is able to operate over varying terrains by adjusting the height of the rear wheels 140 using an adjustment 132 . A series of holes allow a user to select the desired height. A pin, or other detent fits within the hole to maintain the selected height.
[0026] Each rear wheel 140 is supported by a rear wheel support frame 134 is used both for structural purposes as well as providing the axle to support the wheels. This configuration allows the end portion of tricycle to be open and completely accessible. Because of this, a platform 142 is provided to allow easy access. The user can merely step on platform 142 and is ready to go.
[0027] To provide superior braking performance, disc brakes are provided on rear wheels 140 . The disc brakes consist of a rotor 136 and caliper 138 for each rear wheel 140 . Two rear wheel drive chains 150 are provided to transmit the torque from pedals 122 and main drive chain 128 . To further enhance the foldability of tricycle 100 , two rear wheel rotating bushing 152 are provided. During operation, rear wheel support frames 134 are securely held in place by rear wheel clamps 170 . When released, rear wheels 140 may be rotated to a compact position.
[0028] Pedals 122 are rotatably attached to frame 120 using pedal arms 156 using a bearing or bushing 158 . Also provided are two recoil pistons 160 which bias pedals 122 to an operable position and will be discussed in detail below.
[0029] Now referring to FIGS. 5 through 8 , energy efficient tricycle 100 is able to fold for transportation and storage. Handlebar 115 telescopically slides down within steering tube 144 by loosening telescopic clamp 106 ( FIG. 1 ) and then sliding al the way down and then retightening. Next handlebar rotating hinge is release and steering tube 144 folds down until it rests on front tire 114 .
[0030] Now front wheel rotating hinge lock 146 is released and this allows front wheel assembly (wheel 114 , fork 148 , brake 154 and steering tube 144 ) to rotate around 180 degrees so that front wheel 114 is now facing an opposite direction and is alongside cover 126 .
[0031] Next, rear wheel clamps 170 are released and rotated towards the front. In this configuration, tricycle 100 is in a very compact configuration which allows a user to easily carry and transport. It easily fits within a truck of a car, etc. To operate, the procedure is reversed.
[0032] Now referring to FIG. 9 , a seat 174 is provided to allow a user to sit down while operating in a motorized embodiment. Seat 174 is cushioned by riding on a spring shock absorber 176 to absorb bumps and road conditions. Seat 174 may be adjusted forwards and backwards using seat adjustment 178 . Additionally, a height adjustment may be provided (not shown).
[0033] Referring now to FIGS. 10 , 11 and 12 , two direct drive motors 180 are provided to allow a user to have a motorized assist while operating. A battery 168 is used to provide energy to direct drive motors 180 . In this embodiment, the operator may still pedal and have the motors 180 automatically assist during given load situations such as going up hills, speed falls below a selected level or in a completely motorized mode where the pedals are not used or are only used to control the speed. Of course a throttle (not shown) may also be provided which can be mounted on hand grips 102 as is known in the art. In the motorized embodiment or even in a pedal mode if coasting, leg support 172 are provided to allow a user to rest against pedals 122 while standing on platform 142 . Leg supports 172 are made of a resilient material such as foam or rubber to absorb vibration and provide a comfortable support while operating in a standing position.
[0034] Now referring to FIGS. 13 and 14 , half of the transmission is shown. Since there are two pedals 122 , the other half if the transmission is mirrored and not shown in the figures. Pedal arm 156 is rotatably anchored around a pedal arm pivot 190 . Recoil piston 160 is attached to the base of cover 126 and attached to the end of pedal arm. An eccentric gear 186 is rotatably secured to the inside of cover 126 and a recoil cord 192 is attached therein. The other end of recoil cord 192 feeds around a recoil pulley and then a pulley located within pedal arm 156 and secured to cover 126 using a hold down 196 . In this way, as pedal arm 156 rotates down the acceleration is get relatively constant due to the eccentricity of pulley 186 . A main shaft gear 188 is centrally located to mechanically communicate with main drive chain 128 which is connected to main drive gear 166 which transmits torque to rear drive chains 150 .
[0035] Now referring to FIG. 12 , a sensor 184 is provided on main shaft along main drive gear 166 . A sensor disk 182 has magnets or holes or both so that sensor 184 can detect rotational speed and acceleration which can be transmitted to a central processing unit (not shown) as is know in the art. In this embodiment, the CPU can automatically assist the user to add power to help even when pedaling. This option is especially helpful to users who want the benefit of exercise but may not have the stamina to rely solely on muscle power.
[0036] The energy efficient tricycle has a completely open end due the fact that the rear axle is part of the structural support rather than just a axle alone and this allows the user easy access from the back. The instant invention is designed to be operated while standing (except for the seated embodiment) and this is good for exercise, posture and visibility. The center gravity of the instant invention is very low which leads to a very stable ride. Even novice users will feel confident while operating. Unlike standard bicycles and tricycles, each pedal is independent and can be operated using only one pedal if desired. This would allow some disabled users to operate. The height of the tricycle can be adjusted which is extremely useful by allowing a user to adjust for grass, smooth road, etc.
[0037] Although the instant invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. | 4y
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BACKGROUND
[0001] Ailments that affect the respiratory system can occur in people of any age group. These ailments can range anywhere from a temporary condition that requires minor treatment to a permanent disability that requires constant respiratory treatment.
[0002] Treatment of respiratory ailments may involve the use of various components configured in a respiratory circuit. For example, endotracheal intubation tubes are used primarily for the provision of an artificial airway in a patient's respiratory system for the passage of gasses and objects to and from the patient. Endotracheal tubes are typically rigid or semi-rigid cylindrical tubing that may extend from outside of the patient into the patient's lungs. Surgical instruments are then passed through this tubing into the patient's respiratory system in order to perform various medical procedures.
[0003] It may be the case that a patient's respiratory system is so severely impaired that a patient requires some or total assistance in breathing. Ventilators are commonly used to provide artificial respiration to patients in such circumstances. Ventilators are typically connected to a manifold of the breathing circuit to provide for artificial respiration of the patient. Ventilators may be configured so as to completely control the breathing of a patient, or configured such that the ventilator responds only when a patient has labored breathing to a predetermined extent.
[0004] Since a respiratory circuit has components located both on the inside and outside of a patient, the support and stability of a respiratory circuit is important in maintaining an optimal level of performance of the respiratory circuit and related components. It is sometimes the case that the tubing of a ventilator or even the tubing of a respiratory circuit is not rigid and needs to be supported. Also, it is often the case that a patient must be moved during the normal course of treatment, necessitating a change in position of the respiratory circuit. Additionally, even rigid or semi-rigid tubing in a respiratory circuit may need to be supported in order to provide for proper positioning of the tubing in relation to a patient or to provide for optimum patient comfort. In these circumstances, a support arm is sometimes used in order to support components of the respiratory circuit.
[0005] Typically, support arms have been located on a ventilator unit and extended therefrom in order to support tubing of the respiratory circuit. These support arms are typically provided with several joints that allow the support arm to enjoy a full range of motion. The tubing of the respiratory circuit is attached to one end of the support arm. This attachment may be a sliding support or a static connection. A caregiver may then manipulate the support arm such that the tubing is properly positioned. Support arms are typically provided with adjustment screws located at the various points of movement. A caregiver may manually tighten these adjustment screws in order to lock the support arm in the desired location. It is therefore the case that support arms typically require the caregiver to manually tighten and loosen from between two and four adjustment screws in order to properly manipulate and lock the support arm in the desired position. This adjustment requires the use of two hands by a caregiver.
[0006] The present invention is an improvement upon support arms that are used in supporting a respiratory circuit.
SUMMARY
[0007] Objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
[0008] The present invention provides for a support arm for use in a respiratory circuit. The support arm includes a plurality of arm segments that are movably connected with one another such that the arm segments are adjustable with respect to one another. At least one inflatable bladder is provided that is operably disposed at a point of connection between at least two of the arm segments. Inflation of the bladder causes the arm segments to be locked into position with respect to one another. Deflation of the bladder causes the arm segments to be released and therefore positionable with respect to one another. Also included is a respiratory support member that is attached to one of the arm segments. The respiratory support member is configured for engaging and support a component of the respiratory circuit.
[0009] Also provided in the present invention is a support arm as previously discussed where at least one of the arm segments may have a flexible section. Also, a least one of the inflatable bladders is located in the flexible section of the arm segment. The bladder is inflatable to rigidify the flexible section.
[0010] Further provided in the present invention is an embodiment of a support arm as previously discussed where the bladder is configured at a point of connection between all of the arm segments.
[0011] Also provided for in the present invention is an embodiment of a support member as previously discussed where the bladder is within at least one of the arm segments.
[0012] The present invention also includes an embodiment of a support arm for use with a respiratory circuit that has a plurality of arm segments. At least one of the arm segments is a rigid member, and at least one of the arm segments has a flexible section. The arm segments are connected to one another by swivel joints to allow the arm segments to swivel with respect to one another. A bladder is located inside of the arm segments. The bladder may be continuous through the arm segments. The bladder is inflatable in order to effect a locking of the arm segments with respect to one another. A respiratory support member is also provided and may be attached to one of the arm segments and is adjustable with respect to the arm segment. Inflation of the bladder causes a locking of the respiratory support member and prevents adjustment of the respiratory support member with respect to the arm segment. The respiratory support member is configured for engaging a component of the respiratory circuit.
[0013] In one particular embodiment, the present invention further provides for a support arm as immediately discussed where the support arm has three arm segments. Two of the arm segments are rigid and one of the arm segments has a flexible section. The respiratory support member is attached to the arm segment having a flexible section.
[0014] Additionally, the present invention includes a support arm for use with a respiratory circuit as previously discussed where one of the arm segments may have a control member attached thereto. The control member is located proximate to the respiratory support member. Activation of the control member causes deflation of the bladder and unlocking of the arm segments to allow a user to manipulate the arm segments.
[0015] Further provided for under the present invention is a support arm for use with a respiratory circuit as previously discussed where an embodiment of the respiratory support member has a ball and socket connection. This connection is used for effecting adjustment of the respiratory support member in relation to the arm segment.
[0016] In one particular multi-arm embodiment of the invention, the support arm has three segments. Two of the arm segments are a rigid member, and the other has a flexible section. One of the rigid arm segments is adjustably connected on one end to a ventilator. The two rigid arm segments are adjustably connected to one another by a first swivel joint. One of the rigid arm segments and the arm segment having the flexible section are adjustably connected to one another by a second swivel joint. The flexible section is formed by a corrugated member. Further, a respiratory support member is connected to the arm segment that has the flexible section. The respiratory support member has one end configured for engagement with a tube of a respiratory circuit to support the tube. The respiratory support member has a pivot connection to allow for adjustment of the respiratory support member. Also, a flexible bladder is present. The bladder is disposed through the arm segments. Inflation of the bladder effects a locking of the swivel joints and the flexible section to cause a locking of the arm segments and prevent relative motion between the arm segments. Inflation of the bladder effects a locking of the pivot connection of the respiratory support member to prevent adjustment of the respiratory support member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] An embodiment of the present invention is described by way of example with reference to the accompanying drawings, in which:
[0018] [0018]FIG. 1 is a perspective view of an exemplary embodiment of a support arm of the present invention. The support arm is shown supporting a component of a respiratory circuit.
[0019] [0019]FIG. 2 is a perspective view of an exemplary embodiment of a respiratory support member of the present invention. The respiratory support member has a respiratory support adjustment handle attached thereon.
[0020] [0020]FIG. 3 is an exploded perspective view of the respiratory support member shown in FIG. 2.
[0021] [0021]FIG. 4 is a partial cross-sectional view of an exemplary embodiment of a flexible section in accordance with the present invention. The flexible section is free to move, and an uninflated bladder runs therethrough.
[0022] [0022]FIG. 5 is a view of the flexible section shown in FIG. 4 with the bladder inflated. Once inflated, the flexible section is fixed and prevented from moving.
[0023] [0023]FIG. 6 is an exploded assembly view of an exemplary embodiment of a support arm in accordance with the present invention. The drawing shows the swivel joints that connect the support arms.
[0024] [0024]FIG. 7 is an assembled perspective view of the exemplary embodiment shown in FIG. 6.
[0025] [0025]FIG. 8 is a perspective view of an exemplary embodiment of a respiratory support member in accordance with the present invention.
[0026] [0026]FIG. 9 is an exploded assembly view of the embodiment of the respiratory support member shown in FIG. 8.
[0027] [0027]FIG. 10 is a perspective view of an exemplary embodiment of a respiratory support member in accordance with the present invention. The view shows the respiratory support member having a ball and socket connection in a disengaged state.
[0028] [0028]FIG. 11 is a perspective view of the respiratory support member shown in FIG. 10. The drawing shows a bladder acting on sections of the respiratory support member to engage the ball and socket connection and hold the respiratory circuit gripping member.
[0029] [0029]FIG. 12 is an exploded assembly view of an exemplary embodiment of a swivel joint in accordance with the present invention. The drawing shows a bladder disposed within swivel cups and configured to engage a snap ring configuration.
[0030] [0030]FIG. 13 is an exploded assembly view of the swivel joint shown in FIG. 12. The drawing shows the swivel joint at a different angle than that shown in FIG. 12.
[0031] [0031]FIG. 14 is a partial cross-sectional view of an embodiment of a respiratory support member in accordance with the present invention. A bladder is shown in an uninflated state, and two sections of the respiratory support member are not engaged.
[0032] [0032]FIG. 15 is a partial cross-sectional view of the exemplary embodiment of the respiratory support member shown in FIG. 14. The bladder is shown in an inflated state engaging the two sections of the respiratory support member.
DETAILED DESCRIPTION
[0033] Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations.
[0034] An exemplary embodiment of a support arm 10 in accordance with the present invention is shown in FIG. 1. The support arm 10 is designed to be attached to a ventilator (not shown). However, it is to be understood that the support arm 10 may in other exemplary embodiments be attached to objects other than a ventilator. The support arm 10 is configured to hold a respiratory circuit component 28 . In order to properly position the support arm 10 such that it may support the respiratory circuit component 28 , the support arm 10 is constructed of a series of arm segments 12 . Although shown as having three arm segments 12 in FIG. 1, it is to be understood that the support arm 10 may be constructed of any number of arm segments 12 . The arm segments 12 are designed to be movable with respect to one another such that the support arm 10 can be articulated and moved into any desired position. In order to permit relative movement between the arm segments 12 , any manner of suitable swivel joints 24 are provided that connect the arm segments.
[0035] A first arm segment 100 is present and is connected on one end to a ventilator connection adjustment 56 . The ventilator connection adjustment 56 is provided with a ventilator connection adjustment handle 40 . The ventilator connection adjustment handle 40 may be loosened to in order to allow for adjustment of the first arm segment 100 with respect to a ventilator connection member 32 . In one exemplary embodiment of the present invention, the ventilator connection member 32 is connected to a ventilator. The ventilator connection adjustment 56 may therefore allow the first arm segment 100 to move vertically, horizontally, or rotationally with respect to the ventilator connection member 32 . The other end of the first arm segment 100 is connected to a first swivel joint 110 which is also connected to an end of a second arm segment 102 . A point of connection 58 is defined between the first arm segment 100 and the second arm segment 102 . The first swivel joint 110 allows for relative rotational movement between the first arm segment 100 and the second arm segment 102 . In the exemplary embodiment shown in FIG. 1, the first arm segment 100 and second arm segment 102 are both rigid members.
[0036] The second arm segment 102 is likewise connected to a second swivel joint 112 that is also connected to a third arm segment 104 . The second swivel joint 112 allows for relative rotational movement between the second arm segment 102 and the third arm segment 104 . The second arm segment 102 and the third arm segment 104 define a point of connection 58 .
[0037] The third arm segment 104 has a flexible section 18 that runs along a part of the length of the third arm segment 104 . The flexible section 18 allows for the third arm segment 104 to be more precisely adjusted during the adjustment of the support arm 10 . The flexible section 18 is connected on one end thereof to a respiratory support member 16 . The respiratory support member 16 is connected to a respiratory circuit gripping member 50 . The respiratory circuit gripping member 50 engages a tube 46 of the respiratory circuit 28 and positions and supports the tube 46 in the proper location.
[0038] One advantage of a particular embodiment of the present invention resides in having a user adjust the support arm 10 to a desired position using only one hand. Once placed in the proper position for the support of a respiratory circuit 28 , the user may then use a control member 20 to lock the support arm 10 into the desired position. The control member 20 is located on the third arm segment 104 . However, it is to be understood that in other exemplary embodiments of the present invention, the control member 20 may be placed on locations other than the arm segments 12 . However, locating the control member 20 on the third arm segment 104 and proximate to the respiratory support member 16 allows for the user to activate the control member 20 without having to move his or her hand off of the respiratory support member 16 . In other words, the user may position and lock the support arm 10 by the use of only one hand.
[0039] The control member 20 is equipped with an inflation button 34 and a deflation button 36 . The inflation button 34 and deflation button 36 are used to control the inflation and deflation of a bladder 14 that is not shown in FIG. 1, but which runs through the swivel joints 24 , the flexible section 18 , and the arm segments 12 . As will be explained in greater detail below, inflation of the bladder 14 causes the swivel joints 24 and the flexible section 18 to lock in their present position and prevents the support arm 10 from moving. Deflation of the bladder 14 causes these members to again become movable and flexible. Therefore, the support arm 10 of the present invention uses a bladder 14 to control the locking and unlocking of the support arm 10 .
[0040] [0040]FIG. 4 shows an exemplary embodiment of a section of the flexible section 18 in accordance with the present invention. Here, the flexible section 18 is a corrugated member 44 that is composed of corrugated tube 26 which has a series of C-shaped interconnected members 42 . The interconnection of the C-shaped interconnected members 42 allows for the corrugated tube 26 to be flexible and moveable to a desired position. The bladder 14 is shown in an uninflated state running through the interior of the corrugated tube 26 .
[0041] [0041]FIG. 5 shows the flexible section 18 as in FIG. 4, however, the bladder 14 is shown in an inflated state. Once inflated, the bladder 14 pushes against the C-shaped interconnected members 42 and urges them against one another. This urging locks the C-shaped interconnected members 42 against one another and prevents movement of the corrugated tube 26 . Therefore, FIG. 5 shows the flexible section 18 in a locked configuration.
[0042] [0042]FIG. 2 shows an exemplary embodiment of a respiratory support member 16 in accordance with the present invention. The respiratory support member 16 includes two sections 22 movably connected to one another by a screw 52 , as shown in FIG. 3, and a respiratory support adjustment handle 38 . A pivot connection 48 is shown being formed by a ball and socket connection 30 . This connection allows for the adjustment of the respiratory circuit gripping member 50 . The respiratory support adjustment handle 38 may be loosened such that the respiratory circuit gripping member 50 is removable from the respiratory support member 16 . Additionally, the respiratory support adjustment handle 38 may be tightened so that the ball and socket connection 30 is engaged and prevented from allowing the respiratory circuit gripping member 50 to move. Further, as shown in FIG. 3, the bladder 14 may extend into the respiratory support member 16 . When inflated, the bladder 14 is urged against both sections 22 of the respiratory support member 16 . This causes the two sections 22 to pivot and firmly engage the ball and socket connection 30 and prevent the respiratory circuit gripping member 50 from moving. Therefore, the locking of the respiratory circuit gripping member 50 into place may be accomplished through the use of a first adjustment by the respiratory support adjustment handle 38 , and then further securedly locked into place via inflation of the bladder 14 .
[0043] [0043]FIGS. 10 and 11 more particularly demonstrate the locking of the ball and socket connection 30 . FIG. 10 shows an exemplary embodiment of the respiratory support member 16 in accordance with the present invention. Here as shown for clarity, the two sections 22 of the respiratory support member 16 do not engage the ball of the ball and socket connection 30 . In one exemplary embodiment of the present invention, the sections 22 loosedly engage the ball of the ball and socket connection 30 even before inflation of the bladder 14 . The pivot connection 48 is thus loosedly engaged and the respiratory circuit gripping member 50 is free to move. FIG. 11 shows the respiratory support member 16 of FIG. 10 where the pivot connection 48 is engaged and prevented from moving. Here, the arm segment 12 is provided with two apertures 60 . The bladder 14 is present within the arm segment 12 , and inflation thereof forces the bladder 14 to move out of the apertures 60 . The inflated bladder 14 then contacts both of the sections 22 of the respiratory support member 16 and pivots the two sections onto the ball of the ball and socket connection 30 . This creates a locking force on the ball and socket connection 30 and hence results in a locking of the respiratory circuit gripping member 50 .
[0044] Again, this locking action by the bladder 14 is shown in greater detail in FIGS. 14 and 15. FIG. 14 shows the bladder 14 in an uninflated state and the sections 22 of the respiratory support member 16 in an unlocked configuration. FIG. 15 shows the bladder 14 in an inflated state and extending through the apertures 60 to engage the two sections 22 of the respiratory support member 16 . Here, the two sections 22 of the respiratory support member 16 are now in a locked configuration.
[0045] [0045]FIG. 6 shows another exemplary embodiment of a support arm 10 in accordance with the present invention. Here, a third swivel joint 114 is present and is connected to the first arm segment 100 . Also connected to the third swivel joint 114 is a fourth arm segment 106 . The third swivel joint 114 allows for relative movement between the first arm segment 100 and the fourth arm segment 106 . The fourth arm segment 106 is also connected to the ventilator connection member 32 . Therefore, it is to be understood that the present invention includes various exemplary embodiments that consist of any number of swivel joints 24 and arm segments 12 . Also, various exemplary embodiments of the present invention exist where the ventilator connection adjustment 56 and the ventilator connection adjustment handle 40 are not present to allow for the adjustment of the arm segments 12 . Additionally, FIG. 6 discloses an exemplary embodiment of the support arm 10 that does not have a respiratory support adjustment handle 38 that is used to adjust the respiratory support member 16 .
[0046] A respiratory support member 16 that does not have the respiratory support adjustment handle 38 is shown in more detail in FIG. 8. Here, the pivot connection 48 may be formed by simply having a frictional engagement of the ball and socket connection 30 . Additionally, as shown in FIG. 9, the two sections 22 of the respiratory support member 16 do not have to be engaged by a bladder 14 . Here, the two sections 22 are adhered to one another by commonly known techniques such as adhesion or sonic welding. As can be seen, the respiratory support member 16 can be a purely mechanical connection and does not need to have a bladder 14 for its proper operation in other exemplary embodiments of the present invention.
[0047] [0047]FIG. 7 shows this type of respiratory support member 16 being used on a support arm 10 in another exemplary embodiment of the present invention. The support arm 10 shown in FIG. 7 is the assembled support arm 10 of FIG. 6. Here, inflation of the bladder 14 will only effect a locking of the swivel joints 24 and the flexible section 18 , and not the locking of the respiratory support member 16 . It is to be understood that in other exemplary embodiments of the present invention, the third arm segment 104 does not need to have a flexible section 18 included thereon. As such, other exemplary embodiments of the present invention may include a third arm segment 104 that is completely rigid. In addition, the flexible section 18 does not have to be a corrugated tube 26 , but may be made flexible via other means commonly known in the art.
[0048] [0048]FIG. 12 shows an exploded view of the swivel joint 24 in accordance with the present invention. Here, the swivel joint 24 has a snap ring configuration 54 that includes a first snap ring 66 and a second snap ring 68 . The first snap ring 66 is configured to be disposed within a first swivel cup 62 , and the second snap ring 68 is configured to be disposed within a second swivel cup 64 . The bladder 14 is disposed within the first swivel cup 62 and also within the second swivel cup 64 , although this cannot be seen in FIG. 12. While the bladder 14 is in an uninflated state, the first and second snap rings 66 and 68 do not engage one another and are free to rotate with respect to one another. In effect, the swivel joint 24 is free to swivel when the bladder 14 is uninflated.
[0049] The first snap ring 66 is provided with a series of first snap ring projections 70 , and the second snap ring 68 is provided with a series of second snap ring projections 72 . During inflation of the bladder 14 , the first and second snap rings 66 and 68 are urged against one another. The configurations of the first and second snap ring projections 70 and 72 are designed such that they intermesh with one another when the first and second snap rings 66 and 68 are urged against one another. This intermeshing causes a locking force between the first and second snap rings 66 and 68 . This locking force therefore prevents the swivel joint 24 from swiveling and hence locks the arm segments 12 in place.
[0050] [0050]FIG. 13 shows the swivel joint 24 of FIG. 12 from a different angle. Although described as having the bladder disposed within each of the first and second swivel cups 62 and 64 , other exemplary embodiments of the present invention include a swivel joint 24 that has the bladder 14 disposed within only one of the swivel cups 62 or 64 . In addition, other exemplary embodiments of the present invention may include a configuration of the swivel joint 24 where the bladder 14 is continuous through the swivel joint 24 . In such an exemplary embodiment, the bladder 14 may for instance pass through the center of both the first and second snap rings 66 and 68 . Additionally, other configurations of the swivel joint 24 are possible where the swivel joint 24 is locked in place due to the inflation of the bladder 14 . The exemplary embodiment shown in FIGS. 12 and 13 is only one such configuration, and others are conceivable within the present invention.
[0051] Other exemplary embodiments of the present invention may include a configuration where the bladder 14 is continuous throughout all of the arm segments 12 , the swivel joints 24 , the flexible section 18 , and into the respiratory support member 16 . Additionally, other exemplary embodiments may include configurations where the bladder 14 is present within the swivel joints 24 , the flexible section 18 , and the respiratory support member 16 and is connected to all of these sections via tubes through arm segments 12 . In essence, exemplary embodiments of the present invention may include a bladder 14 that is either one or several pieces. Another exemplary embodiment of the present invention exists where the bladder 14 is outside of the arm segments 12 and wraps around the swivel joints 24 to lock them in place. The pressure used to inflate the bladder 14 may be provided by the ventilator through the ventilator connection member 32 . In one particular exemplary embodiment of the present invention, the gas source used to inflate the bladder 14 is provided by the compressor in the ventilator. However, it is to be understood that other gas sources may be utilized in order to inflate the bladder 14 . The bladder 14 allows for the user to manipulate and then lock the support arm 10 into place without having to manually tighten the swivel joints 24 . Such an arrangement is provided when single handed operation of the support arm 10 is desired.
[0052] It should be understood that the present invention includes various modifications that can be made to the exemplary embodiments of the respiratory circuit support arm described herein as come within the scope of the appended claims and their equivalents. | 4y
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This application is a divisional of U.S. Ser. No. 08/684,922 now U.S. Pat. No. 5,830,828 filed on Jul. 22, 1996 which is a continuation of the parent application U.S. Ser. No. 08/304,020 filed on Sep. 9, 1994 (now abandoned).
This invention was made with Government support under DE-AC05-840R21400 awarded by the U.S. Department of Energy to Martin Marietta Energy Systems, Inc., and the Government has certain rights in this invention.
FIELD OF THE INVENTION
The invention relates to the fabrication of superconductors. More particularly, the invention relates to the fabrication of continuous lengths of superconductors having at least one superconducting oxide layer between metallic substrates.
BACKGROUND OF THE INVENTION
The quality of the interface layer between a superconducting material and a metallic substrate is very important in superconducting oxide/metal conductors. The densest and most highly textured superconducting oxide is generally at the interface between the superconducting oxide and the metallic substrate. Consequently, the interface must be smooth, and in tape geometries, planar.
Preparation of long lengths of superconductor is especially difficult. The powder-in-tube method has been previously utilized with some success. Additionally, recent processes include the utilization of multilayered foils coated with superconductor precursor powders that are sealed in a box and unidirectionally rolled. These, and other, methods for preparing long lengths of a super conductor result in interfaces between the superconducting material and the substrate that are less than ideal.
Specifically, fabrication processes such as the powder-in-tube method produce long conductor lengths by starting with large billets containing oxide cores several millimeters or more in diameter. Dimensional uniformity of the core and a smooth interface are difficult to maintain during the large reduction in cross section necessary for fabrication of long thin ribbon conductors.
U.S. Pat. No. 5,034,272 to Matsuno et al. and U.S. Pat. No. 5,002,928 to Fukio et al. describe methods for depositing oxide substances on substrates to form superconductors. Both methods include the deposition of atomized superconductive oxide substances onto a substrate.
Additionally, Shiga et al. (U.S. Pat. No. 5,104,849) describes the manufacture of an oxide superconductor wire. The wire is manufactured by applying oxide powder to cylindrical stabilizing metal materials having differing diameters. The coated metal materials are then concentrically arranged. The wire is rolled, before heating the same to produce the oxide superconducting wire. Other superconductors and methods for manufacturing superconductors are disclosed in U.S. Pat. No. 5,208,215 to Chen et al., U.S. Pat. No. 5,187,149 to Jin et al., U.S. Pat. No. 5,164,360 to Woolf et al., U.S. Pat. No. 5,151,406 to Sawanda et al., and U.S. Pat. No. 5,059,582 to Chung.
The prior art discussed above neither discloses nor suggests the present process or apparatus for manufacturing continuous strips of superconducting materials having a smooth interface between the superconducting material and the substrate. Additionally, the prior art does not disclose or suggest a superconductor manufactured by the present process. The present process reduces the deformation normally resulting from the rolling and drawing utilized by the prior art methods, thus yielding improved texture and less roughness at the interface between the substrate and the superconducting film.
SUMMARY OF THE INVENTION
An object of the invention is to provide long lengths of superconductor and a process for preparing the same.
Another object of the invention is to provide a method for the preparation of long lengths of superconductor having a superior interface between the superconducting material and the metal substrate.
A further object of the invention is to provide a process and apparatus for manufacturing long lengths of superconductor having very good dimensional stability.
These and other objects of the present invention are achieved by the present process for manufacturing a superconductor. The process is accomplished by depositing a superconductor precursor powder on a continuous length of a first substrate ribbon, overlaying a continuous length of a second substrate ribbon on said first substrate ribbon, and applying sufficient pressure to form a bound layered superconductor comprising a layer of said superconducting precursor powder between said first substrate ribbon and said second substrates ribbon. The layered superconductor is then heat treated to establish the superconducting phase of said superconductor precursor powder.
The limited fabrication required by the present invention results in improved homogeneity. Specifically, the present invention only relies upon a two fold reduction in the thickness of the superconductor during the fabrication thereof. The homogeniety produced by the present invention results in a superconductor having better electrical characteristics than those demonstrated by prior art superconductors. Additionally, superconductors made in accordance with the present invention demonstrate an absence of non-superconducting materials at the interface and improved dimensional stability.
Other objects, advantages and salient features of the invention will become apparent from the following detailed description which, taken in conjunction with the annexed drawings, discloses the preferred embodiment of the subject invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of the subject invention.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a process for fabricating continuous lengths of superconductor. The superconductors made in accordance with the subject invention are preferably composed of one or more thin, high-temperature superconducting layers between metallic substrates.
With reference to FIG. 1, an apparatus 1 for the continuous fabrication of long lengths of superconductor is schematically illustrated. A first metallic substrate ribbon 10 is fed through apparatus 1 , while a second separate metallic substrate ribbon 12 is simultaneously fed through the apparatus 1 at the same speed as the first ribbon 10 . The substrate ribbons are long continuous strands. The ribbons are preferably silver or silver alloys (e.g., silver 90-95%/palladium 5-10%), although other materials may be used within the spirit of the invention. The ribbons may be supplied by any conventional mechanism, for example, conveyers 14 , used for continuously feeding long strands of materials.
The first ribbon 10 and the second ribbon 12 are simultaneously fed past a structure 16 for depositing a superconductor precursor powder 18 , preferably the bismuth-based, thallium-based, or yttrium-based families of high temperature oxide superconductor precursor powders, onto the respective ribbons. The precursor powder 18 may be deposited onto the respective ribbons by spray drying or it may be deposited by direct brush application of a powder slurry in a volatile liquid such as butanol. In the preferred embodiment, a suspension of the aerosol precursor powder 18 is stored within a pump assembly 20 . Conventional mechanisms are used to force the precursor powder 18 from the pump assembly 20 .
The superconductor precursor powder 18 is forced through the pump assembly 20 to a pair of spray nozzles 22 , 24 . Preferably, the spray nozzles 22 , 24 operate at 120 kHz to produce 18 um diameter droplets of the superconductor precursor powder 18 . The droplets are deposited on the first and second metallic substrate ribbons 10 , 12 as they pass below the respective spray nozzles 22 , 24 .
The superconductor precursor powder 18 is applied to the substrate ribbons 10 , 12 to permit the formation of a continuous coating of the superconducting material thereon after fabrication of the superconductor is completed. Preferably, the resulting superconductor should have at least a 10 micron layer of the superconducting material after fabrication is completed.
The use of suspensions of aerosol superconductor precursor powder 18 has at least two advantages. First, the high homogeneity and small particle size of aerosol powders permits the preparation of thin coatings which are dimensionally and compositionally uniform. Additionally, high reactivity aerosol powders lead to shorter heat treatment times which permit continuous rather than batch fabrication processing.
After the precursor powder 18 is deposited on the first and second ribbons 10 , 12 , the ribbons move continuously into a low temperature furnace 26 where the precursor powder 18 is dried and surface contaminants are removed from the precursor powder 18 . During this step the precursor powder will bond to respective substrate ribbons.
Once the superconductor precursor powder 18 has been appropriately deposited on the respective first and second metallic substrate ribbons 10 , 12 , and the ribbons have been appropriately heated, the first ribbon 10 and the second ribbon 12 are overlaid to form a mechanical bound layered superconductor 28 composed of a superconducting layer encased within the first and second metallic substrate ribbons. Formation of the layered superconductor 28 is achieved by rolling or pressing the layers with sufficient force to create a bound superconducting layer 28 . The rolling or pressing is done by conventional structures 30 . Preferably, the edges of the first substrate ribbon 10 and the second substrate ribbon 12 are left bare during the deposition step to facilitate the formation of the layered superconductor 28 . As a result, the layers of the layered superconductor 28 are bound together by both substrate to substrate bonding and powder to powder bonding.
If desirable, the edges of the layered superconductor 28 can be folded, or otherwise dressed, to provide a good mechanical bond and to prevent free passage of air borne contaminants.
Finally, the layered superconductor 28 is heat treated to create the desired superconductor. Specifically, the heat treatment converts the superconductor precursor powder to its superconducting phase. The layered superconductor 28 is heat treated by passing the same through an appropriate furnace 32 . After the layered superconductor 28 is heat treated, the process is completed by rolling 34 the layered superconductor 28 to form a highly textured superconducting core.
The preferred embodiment discussed above, permits the continuous fabrication of long lengths superconductor. That is, feeding, depositing, heating, rolling/pressing, heating, and rolling occur without the need to cut the continuous strands of the first and second ribbons 10 , 12 , until the process is completed. Each of these variables is also considered when determining the processing rate for the superconductor.
If, however, the heat treatment step requires too much time to make continuous fabrication of the superconductor feasible, the layered superconductor can be formed in pieces and wound about mandrels. The wound layered superconductor are then heat treated by convention methods to convert the superconductor precursor powder to its superconducting phases. By way of this method 1 kilometer lengths of the superconductor can be manufactured.
In alternate embodiments, the second ribbon can be bare. In such an embodiment, the bare second ribbon is combined with the first coated ribbon in the manner discussed above to form a substrate—superconducting powder—substrate layered superconductor. Whether the second ribbon is coated or bare, the edges of the superconductor can be folded or otherwise dressed to provide a good mechanical bond and to prevent free passage of air borne contaminants. Additionally, multi-layer geometries can be fabricated by co-rolling several coated ribbons and superconductors having a single substrate ribbon are possible.
The process disclosed above results in a smooth interface between the superconducting material and the metal substrate. Metallographic examinations were made of polished cross sections comparing a superconducting oxide/metal superconductor made in accordance with the subject invention and a superconducting oxide/metal superconductor made in accordance with a powder-in-tube method. The superconductor made in accordance with the present invention had a smooth interface between the superconducting material and the substrate when compared to the superconductor made in accordance with the powder-in-tube method. This results in a superconductor having exceptional electrical characteristics, an absence of non-superconducting materials at the interface, and better dimensional stability.
Having described the preferred embodiment of the present invention, it will appear to those of ordinary skill in the art that various modifications may be made to the disclosed embodiment, and that such modifications are intended to be within the scope of the present invention. | 4y
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DEDICATORY CLAUSE
The invention described herein may be manufactured, used, and licensed by or for the Government for governmental purposes without the payment to me of any royalties thereon.
BACKGROUND OF THE INVENTION
In the past, strap assembly latch devices of the over-center type have existed in a variety of shapes and sizes and are generally designed so that the path of the tightening and locking member is at right angles to the plane of the parts being held. Therefore, sufficient operating clearance must exist above the mounting plane of the over-center latch for its locking and unlocking operation. Therefore, these latch devices do not meet the requirement of a latch in which the latching device has a motion plane which is parallel to the surface of the parts to be held and of a low profile type.
Accordingly, it is an object of this invention to provide an over-center latching device that has a low profile and a motion plane which is parallel to and close to the surface of the held parts.
Another object of this invention is to provide a latching device which has rotary motion and over-center clamping action.
Still another object of this invention is to provide a low profile latching device which has a spring action built therein to allow the latching device to give to the over-center latching action and at the same time exert sufficient holding force for tightly clamping the held parts.
Other objects and advantages of this invention will be obvious to those skilled in this art.
SUMMARY OF THE INVENTION
In accordance with this invention, an eccentrically tightened latch device is provided which includes a body strap that has a spring action with one end of the body strap adapted to be connected to a strap or a part to be clamped and the other end of the body strap has an opening therein with an eccentric member mounted through the opening in the body strap and integrally connected to a locking lever for rotation of the eccentric member with the locking lever and relative to the body strap. The eccentric member also has a projecting end that is designed to hold a second strap or body member that is to be clamped relative to the first strap or parts. The locking lever is adapted to be rotated relative to the body strap and move the first and second straps or parts relative to each other and move the eccentric member over-center into a locking position. A dimple detent can also be provided on the body strap and the locking lever for holding these members frictionally in a locking position if desired.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view partially in section of an eccentrically tightened latch device in accordance with this invention,
FIG. 2 is a bottom view of the latching device in accordance with this invention,
FIG. 3 is a sectional view taken along line 3--3 of FIG. 2,
FIG. 4 is a top view of a strap or a member to be held with a portion cut-away and illustrating the opening in this member, and
FIG. 5 is a view illustrating the structure of the eccentric member used in this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawing, the eccentrically tightened latch device includes a body strap 10 that is made of a material such as spring steel and is provided with an opening 12 at one end for being secured, such as by rivet 14, to a strap 16 or other means that is to be clamped. Body strap 10 also has intermediate curved section 18 that is designed to flex and maintain a predetermined force on the parts that are being held together. Also, body strap 10 has an opening 20 through which eccentric member 22 is mounted. Eccentric member 22 includes a first large diameter portion 24 a second stepped diameter portion 26 and an offset holding pin 28 that has a holding tab 30 mounted near one end of pin 28 by being press fitted into a bore within pin 28. A locking lever 32 has a central bore 34 at one end with pin 28 projecting through bore 34 and this end of locking lever 32 is also integrally secured to reduced diameter portion 26 such as by spot welding 36 or other securing means for integrally securing this end of locking lever 32 to reduced diameter portion 26 of eccentric member 22. The other end of locking lever 32 has a stop handle 38 integral therewith for limiting movement of lever 32 toward body strap 10, and locking lever 32 has a dimple portion 40 therein and strap member 10 has a corresponding dimple portion 42 for frictionally holding locking lever 32 and strap 10 in a locking relationship. Pin 28 on eccentric member 22 is secured to locking lever 32 so that pin 28 is at an over-center angle as illustrated in FIG. 2 to positively hold in an over-center relationship. Pin 28 is also designed to be inserted through opening 44 in strap 46 or the other member that is to be clamped relative to strap 16. In this arrangement, lever 32 is actuated approximately 180° from the position illustrated in FIG. 1 so that tab 30 aligns with slot 48 and so that pin 28 and tab 30 can be inserted through opening 44 and slot 48 to connect strap 46 to pin 28. Locking lever 32 can then be rotated to the locking position illustrated in FIG. 1 and tab 30 will prevent strap 46 from being disengaged from pin 28 when in the locking position.
In operation, when it is desired to clamp two straps or members such as members 16 and 46, one end of body strap 10 is connected to the strap to be clamped and pin 28 is inserted through opening 44 and slot 48 to secure strap 46 to the other end of the clamping device. In the position for connection of pin 28 to strap 46, locking lever 32 is rotated to a position approximately 180° from that illustrated in FIG. 1. By rotating lever 32 from the unlocked position to the position illustrated in FIG. 1, lever 32 and eccentric member 22 are rotated relative to body strap 10 and opening 20 within body strap 10 to cause pin 28 to be rotated circumferentially from one side of opening 20 to a position approximately 180° from the open position and in this position cause straps 16 and 46 to be moved toward each other and clamp these straps by the force applied in moving these members together. Pin 28 is moved to an over-center position as illustrated in FIG. 2 in the locking position to insure that the device is held in a clamping position and raised portion 18 of body strap 10 provide elastic deformation of this material and therefore elastic spring holding force of large magnitude to tightly hold straps 16 and 46 together with the device in the locking position. Also, dimples 40 and 42 serve to frictionally hold locking lever 32 and body strap 10 in the locking position. As can be realized, this eccentric latch device has a motion path plane which is parallel to and close to the surface of straps 16 and 46 or the held parts when the device is being placed in the locking position or the unlocked position. This causes a device to be produced which has an advantage that is realized due to the low profile relative to the surface of the parts being held and when being operated to engage or disengage the devices. Clearance above the surface plane of held parts is relatively small and must only be great enough to accommodate the length of eccentric holding pin 28. Consequently, this eccentrically tightened strap device can be used in situtions requiring much less engagement and operating clearance than other present day over-center latching devices. | 4y
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BACKGROUND OF THE INVENTION
This invention relates to a device for picking up sheets from a magazine in a packaging machine. The invention is useful for picking up labels in labelling machines.
Prior art labelling machines are substantially of two types, one with a movable label magazine, and one with a fixed or stationary label magazine. The device intended to pick up the labels from the magazine comprises generally a rotating drum, onto peripheral portions whereof a coating of glue is applied by means of suitable gumming rollers. If the magazine is of the movable type, the withdrawal is effected by imparting to that magazine an oscillatory movement such that each label adhere without slippage on a corresponding area of the drum provided with glue, to remain attached thereto. If, by contrast, the magazine is of the fixed type, then the withdrawal is carried out by means of circular sectors or segments, being controlled by camming means to first contact the gumming rollers and then roll over the labels removing them from the magazine which contains them.
Prior art labelling machines are generally affected by functional drawbacks of importance. Frequently, for example, there occurs a relative movement, i.e. slip, between the label magazine and the drum sector provided with glue, thereby the correct withdrawal of the labels may be precluded. In particular for the fixed drum machines, the arrangement of oscillable circular sectors on the drum poses a whole series of additional problems, among which the presence of high stresses in the overcoming of the dead centers by the camming means, as well as the forcibly limited number of circular sectors, i.e. labels on the drum, due to the large angular size of the latter.
SUMMARY OF THE INVENTION
It is a primary object of this invention to provide a device which obviates such drawbacks, and in particular provided with oscillable circular sectors exhibiting a minimum angular size.
This object is achieved by a device (according to the invention) for picking up sheets from a magazine in a packaging machine, characterized in that it comprises a driving shaft journalled in a base and continuously moving, a pair of plates keyed to said driving shaft, a plurality of oscillating members pivotally supported by said plates through lever means pivoted at locations angularly distributed along a circumference concentrical to said driving shaft, each said oscillating member comprising a cylindrical segment having sheet picking up means and a gear segment of equal radius of curvature, a stationary rack fixed in the proximity of the magazine and in the same plane as the leading sheet, cam control means formed in the base concentrically with said driving shaft for actuating the oscillating members such that the trailing edge of the cylindrical segments come into contact with the leading sheet of the magazine and the gear segments mesh with the rack, thereby the cylindrical segments roll, without slippage, for a fraction of turn of the driving shaft onto the leading sheet to pick it up.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features of this invention will be apparent from the following detailed description of a preferred embodiment thereof, illustrated by way of example in the accompanying drawings, where:
FIG. 1 is a plan view, partly schematic, of the instant device, along section lines at various levels; and
FIG. 2 is a sectional view taken along the plane II--II of FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to such Figures, the instant device comprises a box-like base 1 of rather flattened shape, at the center whereof is a sleeve 2, wherewithin a vertical shaft 4 is journalled through bearings 3.
The shaft 4, below the box 1, is acted upon by driving members not shown in the drawings, which impart to that same shaft a rotation in the direction shown by the arrowhead A. Above the sleeve 2, there are coupled to the shaft 4, through a second sleeve 5, a first plate 6 and second plate 7, being horizontal and parallel to each other. The second plate 7, located above the first closes an opening defined by a cylindrical side 8a which raises from a plate 8, attached to the top portion of the box 1. The edge of the plate 7 is bent downwards externally to the upper edge of the side 8a.
The first plate 6 is provided peripherally with a gear ring 9 meshing with a gear wheel 10 connected to a shaft 11. Said shaft 11 is supported, through bearings 12, in a bushing 13 inserted into and secured to the plate 8, and carries above the latter a gumming roller 14 whereby, as explained hereinafter, glue is applied onto the label picking up members. In the plates 6,7 there are provided a plurality of holes 15 (in the embodiment shown, six in number), which are drilled symmetrically along a respective circumference, substantially intermediate to the radius dimension of the plates themselves, and distributed at equal angles to the center.
In each pair of coaxial holes 15 of the two plates 6 and 7 there are arranged respective pivot pins or shafts 16, carried by bushings 17, which shafts extend parallel to the central shaft 4. Each shaft 16 acts as the fulcrum for a lever arm 18 disposed between the plates 6 and 7 and pivotally engaged at one end in the central portion of said shafts 16. By contrast, at the other end, each lever arm 18 configurates a sleeve 19, with a vertical axis, wherein is in turn pivotally engaged, through bushings 20, a respective shaft 21 also having a vertical axis. The shafts 21 project downwards from the first plate 6 and upwards from the second plate 7, through suitable slotted holes formed in said plates. To the portion thereof which is located above the second plate 7, there is attached a withdrawal sector 22, configurated mushroom-like in a horizontal plane and comprising a certain radial arm 23, locked onto the shaft 21, and a cylindrical segment 24, the center of curvature whereof is located on the axis of the shaft 4 and is equal to the one of the gear ring 9. Said cylindrical segment 24 has a developed length and a height at least equal to the length and respectively height of the labels to be picked up. At the portion located below the first plate 6, the shaft 21 carries a further bushing 25, to the outer surface whereof is coupled a bearing 26. The bearing 26 is engaged in a groove 27 defined between the outer profile of an inner radial cam 28 and the inner profile of an outer radial cam 29 extending in the same plane as the cam 28. The cam 28 is affixed to the base 1 with the interposition of the plate 40, which will be referred to hereinafter, and has a profile which, as may be seen in FIG. 1, is for a greater angle than 180° circular with center on the axis of shaft 4, while the rest of the angle is shaped. The cam 29 circumscribes the cam 28 and is fixed to the same plate 40 with the interposition of blocks 30. The shaft 21 carries, at its lower end underlying the cam 28, a gear segment 31 attached to the shaft through a lug 32, which from the segment 31 projects inwardly.
The withdrawal sector 22 and the gear segment or toothed sector 31 form, together with the shaft 21, whereto they are mounted rigidly, a member which may be oscillated about the axis of the shaft 21 and is pivoted, through the lever arm 18, to the rotating drum constituted by the pair of plates 6 and 7. The gear segment 31 meshes with a stationary rack 33 rigid with a magazine 34 of sheets or labels. In particular, the magazine 34 is disposed such that the leading sheet or label therein is tangent to a circumference with radius equal to the distance between the axis of shaft 4 and the outer surface of the cylindrical segment 24. In FIG. 1, that circumference is indicated at 35 and shown with a dash-and-dot line. That same circumference 35, moreover, represents the pitch line of the gear between the gear segment 31 and rack 33, which is thus aligned in the same plane as said leading label of the magazine 34. By contrast, at the radially inner end, the radial arm 32 of the gear segment 31 bifurcates in a sort of "Y" to originate a pair of short arms 36. Each of such short arms 36 is crossed by a pin 37 carrying a bearing 38 below the short arms themselves. The bearings 38 are inserted inside a groove 39 of a second cam 40. The cam 40 is also a radial one and attached to the base 1 below the first cam 28.
As may be seen in FIG. 1, the profile of the groove 39 of the second cam 40, substantially semicircular over one half of its extension, bifuractes in to branches 41a and 41b at the magazine 34, which branches or legs cross each other shortly after the latter centerline, to then merge together in a single groove. In each of such legs 41a and 41b of groove 39 is inserted, with its respective bearing 38, one of the two pins 37 of each gear segment 31, such as to enable this gear segment 31 and the withdrawal segment 22 connected thereto to rotate about the axis of the shaft 21, thus allowing the cylindrical segment 24 to roll onto the leading one of the labels contained in the magazine 34. Correspondingly, the groove 27 defined between the cams 28,29 which guides the radial movements of the shaft 21, forms sort of an elbow 27a which brings the shaft 21 closer to the magazine 34, thus enabling the gear segment 31 to mesh with the rack 33 along the pitch line 35.
Downstream of the magazine 34, again in the direction of rotation A, there is located an assembly 42 which, in a known manner, is operative to separate the sheets or labels from the cylindrical segments 24. For example, the assembly 42 may comprise a carousel carrying peripherally arranged grippers controlled to grip the labels and release them onto the article to be labelled.
The device described in the foregoing operates as follows. The positions taken by the oscillating members comprising the withdrawal segment 22 and gear segment 31, mounted on the shaft 21, are assumed to be successive working positions taken by one only of such members, during one machine cycle. It is also assumed that movement starts from the position indicated at B, along the direction of rotation A, as shown in FIG. 1. In that position, the outer periphery of the cylindrical segment 24 and gear segment 31 extends along the same circumference concentrical with the rotation axis of shaft 4. While retaining that position, the cylindrical segment 24 moves past the gumming roller 14 which applies on the outer surface of the segment 24 a coating of an adhesive material. During the contact between the gumming roller 14 and cylindrical segment 24, the relative speed is zero, i.e. there occurs no slip, since the roller itself is driven through its gear wheel 10 by the ring gear 9 of the plate 6 which drives the cylindrical segment 24. After applying the film of glue, the oscillating member begins to lean forward, position C, owing to the special shape of the groove 39. In fact, the cam 29 urges the shaft 21 inwardly and forces the first leading one of the pins 37 to deviate inwards. At this point, when the first of such pins 37 is started along the innermost leg 41a of the cam 40, the shaft 21 is guided by the groove 27 such that the second pin 37 is started along the leg 41b, thus contributing to the rotation of the oscillating member about the axis of the shaft 21. As the oscillating member reaches the desired inclination, the shaft 21 moves into the elbow portion 27a, thus controlling the rear edge of the cylindrical segment 24 to approach the edge of the leading label in the magazine. Upon the cylindrical segment 24 contacting the label (position D), the gear segment 31 meshes with the rack 33. It should be noted that, owing to the special configuration of the legs 41a and 41b, the oscillating member is imparted rotation in the opposite direction to the previous one, thereby upon the gear segment 31 meshing with the rack 33, there occurs no relative speed between such two parts. The successive approaching and crossing of the legs 41a and 41b of the groove 39 of the second cam 40 enables the gear segment 31 to roll along the rack 33 wherewith it is in mesh engagement. Simultaneously, the cylindrical segment 24 of the withdrawal segment or sector 22, by rolling over the leading label in the magazine 34, allows the label to separate, which remains attached to the outer surface of the segment 24, to receive glue therefrom. On completion of the label withdrawal from the magazine 34, the successive mutual approaching of the legs 41a and 41b of the groove 39 of the second cam 40 again reverses the direction of rotation of the oscillating member about its shaft 21, position E, until it brings it back to its original radial disposition with respect to the shaft 4. In the foregoing device, the special configuration of the cams 23, 29 and 40, and their split action, one for the radial movement of the oscillating member and one for the rotation thereof about its respective axis of the shaft 21, affords a minimization of the angular size of those elements, as shown in FIG. 1, thereby enabling a larger number of labels to be picked up for a given size of the rotating drum comprising the plates 6 and 7. Furthermore, thanks to the rack 33, the cams 28, 29 and 40 also serve as guides and not as biassing elements for the oscillating members. This reflects in less stresses being imposed, such as would occur, for instance, in overcoming the dead centers. A further advantage connected with the use of the rack 33 resides in the elimination of relative movements or slip between the cylindrical segment 24 of the withdrawal segment 22 and the label, the rolling of one upon the other being rigidly guided by the gear segment 31 meshing with the rack 33 itself.
The invention is susceptible to many variations, according to the type of sheets or labels contained in the magazine; thus, for example, to pick up the sheets, rather than utilizing the adhesive power of the glue coating on the cylindrical segments 24, sucker members connected to a suction pump, or grippers, may be provided. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 60/442,129, filed Jan. 24, 2003.
FIELD OF THE INVENTION
This invention relates to the construction of vessels. More specifically it relates to an apparatus for the construction of vessels having variable sized hulls. Even more specifically, the present invention relates to a vessel having a hull whose size and shape can be modified without refitting the vessel.
BACKGROUND OF THE INVENTION
Waterborne and submersible vessels are typically constructed having a hull of fixed dimensions. This fixes various characteristics of the vessel, such as the capacity, maneuverability, and stability of the vessel. If a vessel owner wishes to modify any of these characteristics, a major overhaul is typically required. This typically involves significant cost in resources and time.
Clearly, then, there is a longfelt need for a vessel having a hull with variable dimensions.
SUMMARY OF THE INVENTION
The present invention broadly comprises a method and apparatus for varying the dimensions of a vessel hull comprising an assembly having a plurality of members pivotally joined. The assembly is operatively arranged to form a portion of the vessel hull. The assembly is operatively arranged to extend and retract to vary the dimensions of the hull when the plurality of members are pivoted with respect to one another.
A general object of the present invention is to provide an apparatus for varying the dimensions of a vessel hull.
Another object of the present invention is to change the carrying capacity, buoyancy, maneuverability, stability, and/or resistance of the vessel.
These and other objects, features and advantages of the present invention will become readily apparent to those having ordinary skill in the art upon a reading of the following detailed description of the invention in view of the drawings and claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing figures, in which:
FIG. 1 is a perspective view of a first embodiment of the present invention installed integral with a vessel hull of a floatable vessel;
FIG. 2 is a side view of the present invention installed integral with a hull of a floatable vessel;
FIG. 3A is a side view of the present invention, mounted on a portion of a hull of a floatable vessel, in a retracted configuration;
FIG. 3B is a side view of the present invention, mounted on a portion of a hull of a floatable vessel, in an extended configuration;
FIG. 4A is a side view of the assembly of the present invention in a retracted configuration;
FIG. 4B is a side view of the assembly of the present invention in an extended configuration, having a membrane attached to an inner portion;
FIG. 4C is a side view of the assembly of the present invention in an extended configuration;
FIG. 4D is a side view of the assembly of the present invention in an extended configuration, covered by a membrane;
FIG. 5A is a top view of a second embodiment of the present invention, in a fully extended configuration;
FIG. 5B is a top view of the second embodiment of the present invention, in a partially extended configuration;
FIG. 5C is a top view of the second embodiment of the present invention, in a fully retracted configuration;
FIG. 6A is a top view of a third embodiment of the present invention covered by a membrane, in a fully extended configuration;
FIG. 6B is a top view of the third embodiment of the present invention covered by a membrane, in a partially extended configuration;
FIG. 6C is a top view of the third embodiment of the present invention covered by a membrane, in a fully retracted configuration;
FIG. 7A is a top view of a fourth embodiment of the present invention covered by a plurality of plates, in a fully extended configuration;
FIG. 7B is a top view of the fourth embodiment of the present invention covered by a plurality of plates, in a partially extended configuration;
FIG. 7C is a top view of the fourth embodiment of the present invention covered by a plurality of plates, in a fully retracted configuration;
FIG. 8A is a side view of the fourth embodiment of the present invention mounted on a portion of a floatable vessel hull and fully extended;
FIG. 8B is a side view of the fourth embodiment of the present invention mounted on a portion of a floatable vessel hull and fully extended;
FIG. 9A is a side view of a fifth embodiment of the present invention mounted on a portion of a floatable vessel hull and fully extended;
FIG. 9B is a side view of the fifth embodiment of the present invention mounted on a portion of a floatable vessel hull and fully extended;
FIG. 10 is a side view of a sixth embodiment of the present invention mounted on a portion of a hull of a submersible vessel;
FIG. 11 is a side view of the sixth embodiment with the assemblies of the present invention fully retracted;
FIG. 12 is a rear view of a seventh embodiment of the present invention mounted on a portion of a hull of a submersible vessel, showing the assemblies fully extended;
FIG. 12A is a side view of the seventh embodiment of the present invention, showing the assemblies fully extended;
FIG. 13 is a rear view of the seventh embodiment of the present invention, showing the assemblies fully retracted;
FIG. 14 is a front view of an eighth embodiment of the present invention mounted on a portion of a hull of a submersible vessel, showing the spherical assembly fully extended; and,
FIG. 15 is a front view of the eighth embodiment of the present invention, showing the spherical assembly fully retracted;
FIG. 16A is a detail of the assembly shown in FIG. 4B , showing a pneumatic or hydraulic extension and retraction means in a retracted configuration;
FIG. 16B is a detail of the assembly shown in FIG. 4A , showing a pneumatic or hydraulic extension and retraction means in an extended configuration;
FIG. 16C is a detail of the assembly shown in FIG. 4B , showing a microelectromechanical extension and retraction means with the assembly extended; and
FIG. 16D is a detail of the assembly shown in FIG. 4A , showing a microelectromechanical extension and retraction means with the assembly retracted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
It should be appreciated that, in the detailed description of the invention which follows, like reference numbers on different drawing views are intended to identify identical structural elements of the invention in the respective views.
A first embodiment of the present invention is shown in FIG. 1 and designated 10 . The invention comprises an assembly for changing the dimensions of a vessel hull. The assembly may be a radial extension/retraction truss structure as disclosed by U.S. Pat. No. 5,024,031 (Hoberman), incorporated by reference herein. As shown in FIG. 1 , the assemblies are mounted on hull sections 12 , 14 , 18 , and 20 of vessel 16 . The assemblies are covered by membrane 40 , and are not visible in FIG. 1 . FIG. 4B shows assembly 38 in an extended configuration with the membrane not shown. FIG. 4D shows extended assembly 38 beneath a cutaway of membrane 40 .
It should be readily apparent to one skilled in the art that the assemblies of the present invention can be extended and retracted by pneumatic, hydraulic, microelectromechanical systems (MEMS), or any other means known in the art. Assemblies actuated by any means known in the art are intended to be within the spirit and scope of the invention as claimed.
FIG. 2 shows portion 22 of a hull of a vessel having hull extension 24 . Apparatus 10 is located on the forward section of hull extension 24 . Membrane 40 is shown covering the assembly of the present invention. The membrane is shown in solid lines for a fully retracted configuration of the assembly and in broken lines for a fully extended configuration of the assembly.
FIGS. 3A and 3B illustrate the buoyancy gain realized by the vessel when the membrane is sealed to the hull with a watertight seal. Membrane 40 is shown covering the assembly in the fully retracted position in FIG. 3A . Membrane 40 is connected to hull portion 34 . The waterline 32 is relatively high with respect to hull 30 . FIG. 3B shows membrane 40 covering the assembly in a fully extended configuration. The expansion of the vessel volume below the waterline 32 increases the buoyancy of the vessel. This leads to the vessel rising in the water. Thus, waterline 32 is relatively lower on hull 30 .
In addition, the expansion and contraction of the assembly will change the magnitude of the wave-making drag created by the hull moving through the water (corresponding to the change in the Froude number). Thus, in some applications, the extent to which the assembly is extended or contracted may be determined by the optimal Froude number (the Froude number resulting in minimum drag for a desired speed) resulting from the assembly size, rather than the buoyancy created by the assembly size.
The watertight embodiment shown in FIGS. 3A and 3B may also be used to compensate for vessel internal (payload) or external environmental moments by extending the different assemblies shown in FIG. 1 to different configurations. If each assembly is extended to a different configuration, each of the assemblies creates a different amount of buoyancy. This allows the operator of the vessel to rebalance the vessel for loading or unloading, passenger crowding, turning, wind, and icing, for example.
FIGS. 3A and 3B show an embodiment that varies the hull geometry while maintaining a watertight seal, thus changing the buoyancy of the hull. However, a watertight seal is not necessary. The apparatuses 10 in FIG. 1 may be mounted on watertight hull portions, which would fix the buoyancy of the vessel. A membrane or plurality of plates would still be necessary to substantially inhibit the free flow of fluid through the apparatus 10 . In this case, the extension and contraction of the assembly would serve only to change the Froude number, changing the magnitude of the drag created. In this case, the configuration of the assembly would be determined solely by the optimal Froude number (the Froude number that minimizes drag at the desired speed). Configurations of the present invention either with a watertight seal or without a watertight seal are both within the spirit and scope of the invention as claimed.
FIGS. 1–3 show a membrane covering the assembly of the present invention. However, the membrane may be connected to an inner portion of the assembly, exposing the assembly to the water. In either case, the membrane may be connected to the hull with a watertight seal. FIG. 4A shows assembly 38 in a retracted position. In one embodiment, membrane 40 is connected to an inner portion of assembly 38 , such that it expands as assembly 38 extends (shown in FIG. 4C ). It should be readily apparent to one skilled in the art that a membrane may be located within the assembly, covering the assembly, or a membrane may be located both inside the assembly and covering the assembly, and these modifications are intended to be within the spirit and scope of the invention as claimed.
A second exemplary embodiment of the present invention is shown in FIGS. 5A–5C and designated 110 . This embodiment is an assembly similar in operation to a diaphragm shutter on a camera. This assembly covers an aperture in the hull when fully extended, and exposes the aperture in the hull when fully retracted. FIG. 5A shows assembly 38 in a fully extended configuration. FIG. 5B shows the assembly in a partially extended configuration. FIG. 5C shows the assembly in a fully retracted configuration.
The assembly may be covered by a flexible membrane, as illustrated in FIGS. 6A–6C . FIG. 6A shows embodiment 210 comprising fully extended assembly 38 covered by membrane 40 . Membrane 40 has an aperture 42 in the center, which is substantially closed when the assembly is fully extended. FIG. 6B shows assembly 38 partially retracted, opening aperture 42 . FIG. 6C shows assembly 38 fully retracted, opening aperture 42 to its widest extent.
In embodiment 310 , a non-circular assembly 74 is covered with plates as shown in FIGS. 7A–7C . FIG. 7A shows embodiment 310 comprising fully extended assembly 74 partially covered by a plurality of plates 44 . When assembly 74 is retracted, plates 44 are also retracted, forming an aperture. FIG. 7B shows assembly 74 partially retracted, with the plurality of plates partially retracted. FIG. 7C shows assembly 74 fully retracted, retracting plates 44 to their greatest extent. As should be readily apparent to one skilled in the art, other means of covering a diaphragm shutter assembly are possible, and these modifications are intended to be within the spirit and scope of the invention as claimed. For example, the plates or membrane may or may not be watertight when the assembly is fully extended. A watertight seal is not required for an aperture such as a bow thruster, as there is a watertight seal within the aperture. The present invention would serve to decrease drag when it is fully extended and the vessel is moving. However, the present invention could serve to both reduce drag and provide a watertight seal for an aperture in a vessel hull.
FIG. 8A shows a diaphragm shutter assembly mounted on hull portion 78 of hull 76 . FIG. 8B shows assembly 74 fully retracted, forming aperture 75 . Aperture 75 faces the forward direction of the hull. This embodiment may be used to cover, for example, a torpedo tube. However, any aperture in a hull may be covered in this manner.
FIGS. 9A and 9B illustrate a fifth exemplary embodiment of the present invention. Hull 76 comprises apparatus 310 . Apparatus 310 is a diaphragm shutter assembly covered by plates 44 . Apparatus 310 covers an aperture in hull 76 containing bow thruster 90 . When bow thruster 90 is needed to maneuver the vessel, apparatus 310 is retracted to reveal aperture 75 . When the bow thruster is no longer needed, apparatus 310 is extended to cover aperture 75 , reducing the drag that would result from exposing aperture 75 during normal travel. An aperture for a water-jet, turbine, or any other aperture in a hull may be covered by apparatus 310 in a similar fashion.
It should be readily apparent to one skilled in the art that the present invention may be used to vary the geometry of hulls of both waterborne and submersible vessels. Variable hulls for both waterborne and submersible vessels are intended to be within the spirit and scope of the invention as claimed. In addition, the invention could be used to vary the geometry of aircraft, including, for example, airships. FIGS. 10–15 illustrate the use of the present invention to vary the dimensions of aircraft.
FIG. 10 shows vessel 412 having passenger compartment 414 . A variable hull section 410 is connected to the front and the back of the vessel. Assembly 438 (shown beneath a cutaway) is covered by flexible membrane 440 . Assembly 438 expands and contracts to change the dimensions of the hull of the vessel. (Both front and rear assemblies are shown fully extended in FIG. 10 .) Fins 416 , 420 , and 418 are constructed to allow assembly 438 to expand and contract while the fins are moved to any position. Vessel 412 can be an airship or a submersible.
FIG. 11 shows the front and rear assemblies fully contracted. This reduces the displacement of fluid by the vessel. As with the previously discussed embodiments, there can be a flexible membrane over the assembly, within the assembly, or both over the assembly and within the assembly. The membrane may be used to contain a fluid less dense than the intended environment, or may simply bound the interior of the vessel. (In the latter case, a less dense internal fluid is held in containers within the hull of the aircraft.) All of the above embodiments are within the spirit and scope of the invention as claimed.
FIGS. 12 , 12 A, and 13 show a vessel 512 having an ellipsoidal assembly 538 that extends and retracts conformally. FIG. 12 is a rear view of vessel 512 with assembly 538 (shown beneath a cutaway of membrane 540 ) in a fully expanded configuration. Passenger compartment 514 is connected to the lower portion of the airship. Horizontal stabilizers 520 and vertical stabilizers 516 are connected to the assembly, and move relative to the passenger compartment when the assembly extends or retracts. Fins 518 may be fixed in size or also composed of assemblies 538 . They are free to move throughout the desired dynamic range regardless of the extent to which the hull assemblies are extended or retracted. As stated above, a flexible membrane covers the assemblies, is within the assemblies, or both. The membranes may be tight, allowing the less dense fluid to be bounded by the membrane(s), or the less dense fluid may be held in containers within the membrane(s). Vessel 512 can be an airship or a submersible.
FIGS. 14 and 15 show vessel 612 comprising a spherical hull 610 . The spherical hull is an assembly 638 (shown beneath a cutaway of membrane 640 ) covered by membrane 640 . Passengers may be carried within compartment 614 . As with previous embodiments, the less dense fluid may be contained within fluid tight membranes covering, within, or both covering and within the assembly. The less dense fluid may instead be held within containers within the hull. Vessel 612 can be an airship or a submersible.
The truss assemblies shown in FIGS. 1–15 form arcuate shapes. In particular, the truss assemblies shown in these figures form a curved shape in two mutually orthogonal planes. Not only is the membrane 40 curved, but the assembly 38 , beneath the membrane 40 , is curved. For example, FIGS. 4A–4D show that assembly 38 forms, in an elevation plane, a curved surface. The profile ranges from elliptical to semi-circular, depending on the extent to which assembly 38 is retracted or extended. FIGS. 5A–5C and 6 A– 6 C show that the assemblies are substantially curved in plan view also. FIGS. 7A–7B show the assemblies curved in a perspective view.
In general, the members forming a present invention truss assembly pivot in respective planes substantially coplanar with the portion of a vessel hull formed by the assembly. For example, in FIGS. 4A–4D , the members forming truss 38 rotate about truss joints 802 . At each joint 802 , the members connected to the joint rotate in a plane that is substantially planar with the surface formed by truss 38 . This coplanar rotation also is shown in FIGS. 7A–7C . In particular, the members are shown rotating “beneath” respective plates 44 , that is, in substantially the same planes as respective plates 44 . Plates 44 , in turn, substantially form the planar surface of embodiment 310 .
FIGS. 16A and 16B show an extension and retraction means 700 for the truss assembly shown in FIGS. 4B and 4A , respectively, connected to a truss segment 702 of assembly 38 . Means 700 includes a cylinder and piston arrangement 704 . Arrangement 704 can be a pneumatic system or a hydraulic system. For the sake of clarity, the ancillary components of arrangement 704 , such as fluid reservoirs, piping, and valves are not shown. In some embodiments, arrangement 704 is connected to truss segment 702 at pins 706 and 708 . In some embodiments (not shown), truss segment 702 is connected to structural elements, such as element 710 . In FIG. 16A , means 700 is retracted, which results in the extended configuration of assembly 38 shown in FIG. 4B . In FIG. 16B , means 700 is extended, which results in the retracted configuration of assembly 38 shown in FIG. 4A .
FIGS. 16C and 16D show an extension and retraction means 800 for the truss assembly shown in FIGS. 4B and 4A , respectively, associated with a truss joint 802 of assembly 38 . FIGS. 16C and 16D show one possible embodiment of a MEMs actuator. However, it should be understood that other types of MEMs actuators, including, but not limited to, linear MEMs actuators, for example, are included within the spirit and scope of the claims. Means 800 is a MEMS actuator. MEMS actuator 800 includes hub 804 and variable pole element 806 . As shown in FIGS. 16C and 16D , hub 804 has a fixed north and south magnetic pole configuration. However, the magnetic configuration of element 806 is defined by the direction of electrical current flow as controlled by a switch (not shown). In FIGS. 16C and 16D , the current directions are reversed, resulting in the “flipping” of the north and south magnetic poles in element 806 . In FIG. 16C , the north and south poles of hub 804 and the south and north poles, respectively, of element 806 are mutually attracted, causing element 806 to assume the position shown. When the switch is flipped to reverse the direction of the electrical current, element 806 assumes the magnetic configuration shown in FIG. 16D . Reversing the magnetic configuration of element 806 in FIG. 16C causes a magnetic torque 808 as shown in FIG. 16D . For example, switching from the magnetic polarity shown in FIG. 16C to the magnetic polarity shown in FIG. 16D causes the north poles of hub 804 and element 806 , which are aligned, to push away from each other, causing element 806 to rotate counterclockwise. At the same time, the mutual attraction of the respective north and south poles of hub 804 and element 806 also causes element 806 to rotate counterclockwise. Thus, element 806 rotates from the position shown in FIG. 16C to the position shown in FIG. 16D . By reversing the direction of the electrical current flow again, element 808 can be made to rotate clockwise from the position shown in FIG. 16D to the position shown in FIG. 16C . By reversing the direction of the electrical current flow again, element 808 can be made to rotate clockwise from the position shown in FIG. 16D to the position shown in FIG. 16C .
Thus, it is seen that the objects of the present invention are efficiently obtained, although modifications and changes to the invention should be readily apparent to those having ordinary skill in the art, and these modifications are intended to be within the spirit and scope of the invention as claimed. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 13/031,374, filed Feb. 21, 2011, which is a continuation of Patent Cooperation Treaty Patent Application Ser. No. PCT/US09/054522, filed Aug. 20, 2009, which claims priority to U.S. Provisional Patent Application Ser. No. 61/090,396 filed Aug. 20, 2008, The entire disclosure of each of the foregoing applications is incorporated herein by reference,
BACKGROUND
Wastewater from municipal sewage systems, large-scale agricultural operations, and industrial waste product systems often includes large amounts of organic and inorganic waste material that, if left untreated, can create severe odors due to anaerobic decay and can generate toxic products. Treating such waste generally involves collecting the organic and inorganic waste material in a stream of liquid or water, and collecting the waste in settling pools, ponds, or lagoons. Thereafter, the waste is allowed to settle in progressive settling ponds, pools, or lagoons, and any floating detritus is allowed to decompose, allowing the effluent to be run off relatively free of the debris for further treatment or clarification, During this process, the addition of oxygen sufficient to meet the basic oxygen demand (BOD) is preferred so that the waste material in the water will undergo biodegradation, that converts the wastewater into a relatively nontoxic, non-offensive effluent, Since anaerobic decomposition is inefficient as compared to aerobic decomposition, and anaerobic decomposition often results in the production of a malodorous sulfur-containing gas, it is preferred to add oxygen to the wastewater to increase decomposition while reducing or eliminating the existence of anaerobic decomposition. Various approaches have been used, typically by surface aeration or by submerged aeration systems wherein air is pumped below the surface of the water, or sometimes by a rotating impeller that mixes the wastewater and entrains air into that water. Examples are to be found in U.S. Pat. Nos. 3,521,864; 3,846,516; 5,874,003; 6,145,815; and 6,241,221.
While each of these previous designs may have application in that have been considered and developed, there is still a need for an improved apparatus for economically mixing a large quantity of wastewater with sufficient air to at least satisfy the BOD of the wastewater to promote biodegradation of the waste materials, and/or to reduce or eliminate offgassing of offensive odors. Further, it will be appreciated that in the collection of sewage from household waste, a great deal of human hair accumulates in settling pools, ponds, or lagoons, causing large mats or strings of hair mixed with other organic matter, which will often cause entanglement of material in wastewater treatment equipment, and can result in equipment failure—an issue that is not addressed in the foregoing prior examples. As such, a design that is not adversely affected by the hair and stringy waste that accumulates in wastewater facilities, while providing oxygenation of a large variety of settling pools, ponds, or lagoons in an energy efficient manner and producible at a cost effective price would be greatly appreciated.
SUMMARY
These needs may be satisfied by a water treatment unit that can be situated in a body of water such as a tank, pool, pond or lake. The water treatment unit includes a riser having an intake that can be situated below the surface of the water. A chamber is coupled to an upper portion of the riser stand that has a base, a sidewall extending upward from the base, and a top that can be located above the water surface in the body of water. The riser has an outlet adjacent the top of the riser into the chamber. The chamber has at least one water outlet in a lower portion of the chamber, and an air inlet in an upper portion of the chamber. The water outlet from the chamber can take the form of one or more outlets through the chamber base. A directionally adjustable pipe can be coupled to the outlet from the chamber so that the outflow from the chamber can be used to develop a desired flow pattern, such as a toroidal flow, within the body of water.
An impeller is connected to the riser to move water upward from the intake and out through the upper opening of the riser into the chamber. The upper opening can take the form of a plurality of openings spaced around an upper portion of the riser. The impeller can take the form of a motor coupled to the chamber upper portion immediately above an upper end of the riser and a shaft coupled to the motor and to at least one propeller situated within the riser below the water level in the body of water. The water flow from the riser into the chamber creates a head within the chamber forcing water out through the water outlet in the lower portion of the chamber.
The water treatment unit riser upper opening can be surrounded by a depending flange. The depending flange can intercept and outward flow of water from the upper opening of the riser. The outward flow of water will also become downwardly directed at least due to the influence of gravity. The outward and downwardly directed flow of water can entrain air coming through the air inlet in the upper portion of the chamber to elevate the level of oxygen dissolved in the water within the chamber, which then flows out through the outlets in the chamber base. The downwardly directed water can also mix with water in the chamber in a turbulent manner to generate a surface foam.
The water treatment unit can be used to move water from the body of water up through the riser, and out through the laterally directed openings into the chamber adjacent to the air inlet. The water moving out the laterally directed openings of the stand pipe, mixes with air drawn in through the air inlet to oxygenate the water, and the oxygenated water exits the chamber into the body of water through one or more water outlets in the lower portion of the chamber due to the head developed by the inflow of water into the chamber. The outward flow of water from the chamber can cause a toroidal or other desired flow of water within the body of water surrounding the water treatment apparatus.
Other features of the present disclosure and the corresponding advantages of those features will become apparent from the following discussion of the preferred embodiments of the present disclosure, exemplifying the best mode of practicing the present disclosure, which is illustrated in the accompanying drawings. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the disclosure. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views, but not all reference numerals are shown in each of the figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a water treatment unit embodying the present disclosure.
FIG. 2 is a perspective view of a water treatment unit according to the present application with a portion broken away to reveal the interior the water treatment unit.
FIG. 3 is a sectional view of the water treatment unit shown in FIG. 1 taken along line 3 - 3 .
FIG. 4 is a view similar to FIG. 3 of a second water treatment unit embodying the present disclosure.
FIG. 5 is a perspective view of a water treatment unit according to the present application, having a portion broken away to reveal the interior the water treatment unit.
DESCRIPTION
Turning now to FIGS. 1 and 2 , according to at least one embodiment of the present application, a water treatment unit 10 includes a riser or pump barrel 12 having a lower end 14 and an upper end 16 that is optionally fabricated from plastic, metal (including, for example, galvanized steel, enamel-coated steel, aluminum, stainless steel, or other malleable metals), or other materials known in the art. Further, according to at least one embodiment, one or more inlets 18 are be provided around lower end 14 of riser 12 . According to at least one optional embodiment, a bottom end 20 is optionally added to lower end 14 of riser 12 , whereby one or more inlets 18 may be fitted to lower end 14 of riser 12 , and may optionally include a ballast member 22 as shown in FIG. 3 to assist in maintaining the water treatment unit 10 upright. It will be appreciated that the weight of ballast member 22 may be adjusted to adjust the height at which the upper end 16 floats above the water level of the lagoon, pond, or tank W.
According to at least one embodiment, riser 12 is sized and shaped to be of any required length and cross-sectional area as required by the necessary water flow, amperage requirements, and viscosity of wastewater. One or more water discharge outlets 24 can be provided around the upper end 16 of the riser 12 , A cap 26 can be coupled to the upper end 16 of the riser 12 by fasteners 28 or other means to substantially close the upper end 16 of the riser 12 . The cap 26 can include a peripheral wall 30 that surrounds the upper end 16 of the riser 12 .
A mixed wastewater chamber 32 optionally surrounds the upper end 16 of the riser 12 and peripheral wall 30 , formed by a housing comprising a chamber floor 34 that is optionally fixed to a selected portion of riser 12 , located between the upper end 16 and the lower end 14 , by fasteners, welding, fusing or other means of connecting the material comprising riser 12 and chamber floor 34 . Mixed wastewater chamber 32 further optionally comprises wall 42 and chamber ceiling 46 , with chamber floor 34 , wall 42 , and chamber ceiling 46 meeting to cause wastewater chamber 32 to attach to, and substantially enclose riser 12 . Chamber floor 34 optionally comprises one or more openings 39 in chamber floor 34 , whereby fluid that has been pumped through riser 12 cascades out through discharge outlets 24 , into mixed water chamber 32 , and building pressure forces the resulting mixed fluid down and out through the one or more openings 39 in chamber floor 34 . Further optionally, chamber ceiling 46 comprises chamber ceiling opening 54 through which air can be drawn into the chamber 32 . An intermediate wall 58 optionally depends from chamber ceiling 46 outside peripheral wall 30 (if present in the embodiment) and inside the outer wall 42 . In operation, turning to FIG. 3 , intermediate wall 58 separates an inner chamber 60 from the remainder of chamber 32 , as intermediate wall 58 is sized to depend from chamber ceiling 46 to reach water level W 1 inside chamber 32 such that no air gap exists between water level W 1 and a bottom portion of inner intermediate wall 58 . While each of the peripheral wall 30 , intermediate wall 58 and chamber wall 42 are illustrated to be portions of right cylinders in shape in FIGS. 1 , 2 , and 3 , other shapes may be adopted for one or more of the walls 30 , 42 and 58 .
According to at least one embodiment, motor 64 , such as a ¾ HP electric motor or any other properly sized and powered motor, engine, or other revolving powerplant, can be fixed to and supported by the cap 26 as shown in FIGS. 2-4 , or motor 64 may be attached to a motor plate 110 that is sized larger than chamber ceiling opening 54 , thereby allowing motor 64 , and motor plate 110 (shown in FIG. 5 ) may be removably attached to chamber ceiling 64 by way of fasteners such as bolts, wing nuts, or other fastener means. Shaft 66 is optionally connected to motor 64 by coupling member 65 extending downward through cap opening 68 in cap 26 in general axial alignment with riser 12 . It will be appreciated that by utilizing a motor plate that fits over the top of chamber ceiling opening as shown in FIG. 5 , removal of the motor 64 , shaft 66 , and propellers 70 are readily pulled from riser 12 to allow for inspection of components, sharpening of blades, and general maintenance or repair of the equipment with minimal disassembly effort.
According to at least one embodiment, at least one propeller 70 is coupled to shaft 66 to cause rotation of shaft 66 by the motor 64 , thereby creating an upward flow of fluid from a body of water outside waste treatment unit 10 into riser 12 . A buoyant member 72 , such as that shown in FIG. 4 , may be attached to waste treatment unit 10 in any manner to cause waste treatment unit to sit at a specified height in a body of water or fluid such that waste treatment unit 10 sits at a predetermined level W as shown in Fig, 3 . It will be appreciated that level W may be determined as a different height for different embodiments of waste treatment unit 10 , and depending on the application for which waste treatment unit 10 is utilized. It will be appreciated that buoyant member 72 can take many forms, including foam filled buoys, air filled bladders that may be adjusted to adjust where water level W sits in relation to waste treatment unit 10 , or any other buoyant material. For example, two buoyant floats such as two 2′×4′ polyethylene coated foam dock floats available from Formex Manufacturing, Inc., Lawrenceville, Ga., can be utilized, along with cross members or other attaching members to hold waste treatment unit 10 in the proper relation to the fluid line, Additionally, two or more torque lines can be connected to the outer wall 42 to prevent rotation of the treatment unit 10 when the motor 64 is running.
As shown in FIG. 3 , according to at least one embodiment, multiple propellers 70 are employed, whereby a first propeller 70 is included along shaft 66 near the lower end of riser 12 , and a second propeller 70 is included along shaft 66 near upper end 16 of riser 12 . In at least one exemplary embodiment, second propeller 70 is positioned such that the propeller is at least partially exposed to air, thereby allowing second propeller to entrain air into the water or fluid flowing past second propeller 70 and into discharge outlets 24 , According to at least one embodiment, second propeller is positioned relative to the height of the discharge outlets such that air is entrained into the water at a size less than 1.0 mm, 0.5 mm, less than 0.25 mm, less than 0.15 mm, or less than 0.1 mm in size for the given motor/propeller combination,
An alternate embodiment is shown in FIG. 4 in which the water treatment unit 10 is shown to include a riser or pump barrel 12 having a lower end 14 and an upper end 16 . One or more inlets 18 can be provided around the lower end 14 of the riser 12 , A bottom end 20 can be provided that may include a ballast member 22 to assist in maintaining the water treatment unit 10 upright. The riser 12 can be of any required length. One or more water discharge outlets 24 can be provided around the upper end 16 of the riser 12 . A cap or lid 26 can be coupled to the upper end 16 of the riser 12 by fasteners 28 or other means to substantially close the upper end 16 of the riser 12 . The cap 26 can include a depending wall peripheral wall 30 that surrounds the upper end 16 of the riser 12 ,
A chamber 32 can surround the upper end 16 of the riser 12 and the peripheral wall 30 . A chamber floor or bottom plate 34 can be fixed to an intermediate portion 36 of the riser 12 , located between the upper end 16 and the lower end 14 , by fasteners 38 or other means. The chamber floor or bottom plate 34 can have one or more openings 39 and an outer edge 40 that can be circular. The chamber 32 can be further defined by a shroud outer wall 42 that can have a lower edge 44 that contacts the chamber floor or bottom plate 34 . A chamber ceiling 46 can have an outer edge 48 that can be fixed to or unitary with an upper edge 50 of the shroud outer wall 42 . The chamber ceiling 46 optionally includes chamber ceiling opening 54 through which air can be drawn into chamber 32 , The top wall 46 can be spaced from the cap 26 by means of spacers 56 , which can be adjustable, The spacers 56 are illustrated to be fixed to the cap 26 and contacting top wall 46 , but the spacers can be fixed to the top wall 46 and contacting cap 26 . An intermediate wall 58 can depend from the top wall 46 outside the peripheral wall 30 and inside the outer wall 42 . The intermediate wall 58 can be seen to separate an inner chamber 60 from an outer chamber 62 . While each of the peripheral wall 30 , intermediate wall 58 and outer wall 42 are illustrated to be portions of right cylinders in shape, other shapes may be adopted for one or more of the walls 30 , 42 and 58 .
A motor 64 , such as a ¾ HP electric motor, can be fixed to and supported by the cap 26 . A shaft 66 can be coupled to the motor 64 by coupling member 65 to extend downward through an opening 68 in cap 26 in general axial alignment with the riser 12 , At least one propeller 70 can be coupled to the shaft 66 so that rotation of the shaft 66 by the motor 64 can cause an upward flow of water within the riser 12 , A buoyant member 72 can be coupled to the chamber floor 34 or to outer wall 42 to maintain the top wall 46 above the surface of the water surrounding the water treatment unit 10 , particularly in high water situations. In low water situations, the water treatment unit 10 may rest on the bottom 21 of the ballast unit 22 , Two or more torque lines 41 can be connected to the outer wall 42 to prevent rotation of waste treatment unit 10 when the motor 64 is running.
The operation of the water treatment unit 10 is illustrated, particularly in FIG. 3 . As shown in at least one exemplary embodiment, waste treatment unit 10 is be placed in a body of water W such that riser 12 extends downward to a desired depth. It will be appreciated that the lower portion 14 of riser 12 may be made of a material that allows the addition of segmented tubes or other structures, such as PVC piping, stainless steel piping with threaded extensions, or other such structures that allows the ultimate depth of riser 12 to be determined by a user such that stratified layers of water in a treatment lagoon can be specifically targeted to be drawn up through riser 12 for oxygenation and displacement, thereby allowing water in the lower, anaerobic areas of a lagoon to be drawn up, oxygenated, and discharged. It will be appreciated that when motor 64 is powered on, water or the fluid in the lagoon, pond, or tank is drawn into the riser 12 through inlets 18 and propelled upward through the riser 12 by one or more propellers 70 , exits the riser 12 through outlets 24 into chamber 32 . The continuous flow of fluid into the chamber 32 generally causes the fluid surface level L within the chamber 32 to be slightly higher than the water surface surrounding the chamber, thus providing a hydraulic pressure forcing the water out the openings 39 in the chamber floor 34 . The size of the riser 12 , motor 64 , and propellers 70 are desirably selected so that between about 600 to 1000 gallons of water per minute can be pumped up though the riser 12 into the chamber 32 . Furthermore, fluid surface level L within chamber 32 may be manipulated by a user such that the pressure therein is increased, thereby allowing greater amounts of oxygen to be transferred. For example, the surface level L may be manipulated to increase sufficient to create a hydraulic pressure equal to approximately at least 1.1 atmospheres, at least 1.2 atmospheres, at least 1.3 atmospheres, or at least 1.4 atmospheres hydraulic pressure, thereby entraining more oxygen therein.
This flow of fluid through riser 12 causes a continuous air inflow into the upper end 16 of riser 12 though chamber ceiling opening 54 , the air being mixed with the fluid within riser 12 at the point of discharge of the fluid from riser 12 through discharge outlets 24 . As fluid cascades out of discharge outlets 24 , into inner chamber 60 , out into chamber, chamber 32 and forcefully exits openings 39 , the direction and depth at which the oxygenated fluid is discharged can be determined the optional use of flow direction pipes 74 and 76 , which may be adjustable with respect to each other to selectively determine the depth and direction of flow direction pipes 74 and 76 . By selective direction of pipes 74 and 76 , the fluid outflow from waste treatment unit 10 can at least partially oppose or offset the rotation of the treatment unit 10 due to the torque provided when the motor 64 is running. The flow of water within the chamber 32 may cause the development of foam on the surface of the water within chamber 32 , depending on the fluid conditions. According to at least one exemplary embodiment, accumulating foam can be vacuum withdrawn through pipe 78 , or in another embodiment, the foam will automatically eject through pipe 78 due pressure build-up. Additionally, it will be appreciated that an activated charcoal filter may be added to pipe 78 to reduce any odor produced from the treated water as gas is offgased.
Turning now to FIG. 5 , according to yet another exemplary embodiment, waste treatment unit 10 optionally includes a movable shearing blade 120 attached to shaft 66 , and a fixed shearing blade 122 . Both fixed shearing blade 122 and movable shearing blade 120 may comprise metal, including steel, stainless steel, hardened steel, hardened stainless steel, or ceramic, carbide, or other suitable material. In practice, movable shearing blade 120 may be urged into close planar contact with fixed shearing blade 122 through the use of a bushing 124 , whereby the bushing comprises a spring, rubber, or other material able to urge shearing blade 120 toward fixed shearing blade 122 . By urging movable shearing blade 120 toward fixed shearing blade 122 , when motor turns shaft 66 , movable shearing blade rotates, and when passing over the top of fixed shearing blade 122 , any material caught between movable shearing blade 120 and fixed shearing blade 122 is sliced, thereby reducing the likelihood of long, stringy waste from becoming entangled with propeller 70 or clogging discharge outlets 24 . Further, bushing 124 allows a slight upward movement of the blade in relation to fixed shearing blade, any hardened or uncuttable objects may pass between the two blades, thereby preventing seizure of the unit and potential damage to motor 64 .
In application, at least one embodiment an oxygen transfer rate of at least 0.50 kg/hr O 2 transfer can be achieved while utilizing approximately 4.5 to 5 amps of electricity at 120 volts. In at least one additional embodiment, an oxygen transfer rate of at least 0.8 kg/hr O 2 transfer can be achieved while utilizing approximately 4.5 to 5 amps of electricity at 120 volts.
Turning now to FIG. 4 , it will be appreciated that additional flow direction pipes 74 and 76 may be added to inlets 18 , thereby allowing a user to further control to the source of water collection, and further allowing selective uptake of water at points in the lagoon where the oxygen level is likely to be the lowest. Likewise, by selectively placing flow direction pipes 74 and 76 to intake at points in a lagoon that are most likely to have low oxygen levels (both in terms of height and position within the lagoon), and by selectively placing flow direction pipes 74 and 76 for dispelling oxygenated water from the waste treatment unit 10 , a more consistently oxygenated lagoon can be developed by developing both inward and outward flow currents that adequately disperse oxygenated water and intake low oxygenated water, thereby allowing permeation of oxygen throughout the lagoon without creating a turbulent flow of water that precludes the settling of organic matter that is required in clarification or settling tanks or lagoons. Further, due to the fact that flow can be directed with relative precision and with relatively low pressure, a reduced amperage is required to operate motor 64 , thereby resulting in increased energy efficiency. Finally, it will be appreciated that the use of such directional flow allowing slower water transfer to occur further allows the use of propeller speeds to entrain air while not dispersing bacterial colonies known as flock.
Additionally, it will be appreciated that utilizing the flow direction pipes 74 and 76 , water may be utilized to direct water brought up from warmer strata in the winter to help eliminate ice build-up on the surface of outdoor lagoons, which further allows for additional oxygenation of the lagoon.
While these features have been disclosed in connection with the illustrated preferred embodiment, other embodiments of the disclosure will be apparent to those skilled in the art that come within the spirit of the disclosure as defined in the following claims. Further, it will be appreciated that in very large ponds or lakes, it may be convenient or necessary to employ two or more water treatment units 10 to ensure a total water flow volume sufficient to provide sufficient oxygen to satisfy the BOD of the body of water. | 4y
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DISCLOSURE
This invention relates generally as indicated to an exothermic welding jig, molds for use with the jig, and a method of exothermic welding.
BACKGROUND OF THE INVENTION
Exothermic welding has been widely employed in the formation of electrical connections or in the welding of steel such as rails and in joining reinforcing bar. The welding process utilizes powdered materials such as copper oxide and aluminum. The powdered material is placed in a crucible and ignited. Typically in electrical connections, the reduction of the copper oxide by aluminum produces molten copper and aluminum slag. Molten aluminum and molten iron can be made in similar fashion. The molten copper flows from the crucible over the parts to be welded contained in a mold, melting them and welding them together, forming a high quality low impedance connection. The slag forms on top and is removed. Such welding metals or powders, and a wide variety of molds and other related accessories are sold under the registered trademark CADWELD® by Erico Inc. of Solon, Ohio.
Most typically the molds are formed by two graphite blocks vertically split which are hollowed out to form the crucible, a receiving mold chamber for the pieces to be welded and interconnecting tap hole. The mold blocks are opened and closed by a toggle action handle frame or clamp which extends out to the side of the molds. Reference may be had to Burke U.S. Pat. Nos. 2,904,862 and 3,004,310 for illustrations of such exothermic cast welding mold assemblies. Where the mold parts are horizontally split, it is usual that the bottom of the block containing the crucible forms the top portion of the mold while the other or lower portion is hinged to separate from the top portion. The two mold blocks are also supported for opening and closing by a toggle clamp, again extending directly from the side of the mold blocks. The handles projecting laterally from the molds make the assemblies difficult to use in cramped quarters such as a narrow ditch where conductors for ground mats or other grounding systems, or cathodic protection connections, are often made.
Chain slings are typically used with mold assemblies for welding reinforcing bar such as shown in U.S. Pat. Nos. 3,234,603 and 3,255,498. In such patents the mold is in the form of a metal sleeve and separate molds are provided for the crucible and the tap hole or tundish, all of which may either be set one on top of the other or be held together by chain slings. The assembly and disassembly is time consuming, and more so in cramped quarters.
The molds are usually graphite or ceramic, and may be cleaned and reused. Properly handled, used and cleaned, molds may make fifty or more connections. However, improperly used or cleaned molds have to be replaced more often. Also, the molds have to be replaced or changed for different types of connections. There are literally dozens of types of connections and within each type of connection classification there are a wide number of conductor size variations. Also, the weld metal or powder is carefully pre-packaged by size. While the mold forming parts which receive the parts to be welded and which form the weld, need to be carefully designed and machined, that is not necessarily true of the crucible, and yet the crucible forms the largest portion of the mold system. Where the mold part and crucible are formed from a common block of graphite, excessive wear or damage to any part of the mold part requires that the whole thing be discarded even though the crucible is still usable. Accordingly it would be advantageous to have a system where the crucible was separate from the mold forming parts and the mold parts could be readily changed or substituted, while at the same time positioning the crucible and mold parts for quick and convenient cleaning for reuse.
If the crucible and mold are separable, it is important that when assembled they be held together with the proper degree of force so that no molten metal leakage occurs, and yet not too much force which might damage the mold parts, particularly if foreign matter is in the interface. It is also important that such force be quickly applicable or released, and readily adjustable.
It is also important that the jig or frame for holding the mold parts be low cost, able to separate and yet lock the mold parts quickly, and to hold the crucible for opening and closing travel with a mold part, and be properly held to such part so that no leakage occurs. It is also desirable that the crucible be easily removed and handled for convenient cleaning or preparation before assembly and clamping to the molds. In some situations, it may be desirable or even required to change crucibles. An example would be a crucible using a filter system for low emissions suitable for welding in confined spaces such as sold under the registered trademark EXOLON® by Erico, Inc.
It would also be important that the frame or clamp operate easily in tight quarters such as a ditch, and be self supporting. It would also be particularly advantageous if the frame or jig would partially open and hold the mold parts for insertion of the cable or parts to be welded, and fully open and hold the parts for cleaning. In cleaning a crucible, it is advantageous if a tool is inserted from the normally downwardly facing tap hole to knock any slag or residue out of the larger upper end of the crucible. In other words the crucible is best held inverted or upside down for cleaning.
Apparatus for making welds where two relatively thick conductors cross forms what is known as a lapped or cross connection. The molds for making this type of connection are complex, usually requiring two people to assemble for welding, and disassemble and clean. The molds comprise a bottom mold part forming part of the weld cavity and two vertically split molds forming both parts of the weld cavity and the crucible. Wear or damage to one part usually requires the whole assembly be replaced and a whole different set is required for each size.
SUMMARY OF THE INVENTION
A welding jig includes supports for two mold parts and a separable crucible. The mold parts may be open and closed with a toggle mechanism while the crucible is held in place by a separate toggle. The jig includes a vertically extending fixed handle about the size of a cane. The lower end includes a platform with barbs or spikes for planting in the earth or other surface so that the jig can be positioned to stand upright. A lower mold part is removably secured at the bottom of the handle with the formed mold surface facing upwardly. An elevator telescopes over and slides up and down on the handle. The lower end of the elevator includes a pivot supporting a crucible guide bar. Telescoped on the crucible guide bar is a crucible tube which includes a projecting handle and a support for a crucible. The crucible guide bar removably supports an upper mold part with the formed mold surfaces normally facing downwardly and in vertical alignment with the lower mold part.
The crucible tube and crucible guide bar are interconnected by a simple toggle pivoted to the guide bar and snapping into a seat in the form of a hook projecting from the crucible tube. The toggle is adjustable and effective to press the crucible against the upper mold part only when the mold part and crucible are mounted on the jig. When the toggle is released, the crucible, crucible tube and handle may be removed as a unit. This enables the crucible to be mounted and removed from the crucible tube when the latter is disassembled from the jig. It also provides the crucible with an assembly and manipulation handle.
The elevator is moved along the handle by a second toggle which includes a built-in friction brake in the form of Belleville washers to hold the elevator in all intermediate positions when released. This enables the operator to open the molds partially for conductor or insertion of other parts, or fully for removal, assembly or mold cleaning, without requiring one hand holding the molds open. When opened, using the handle of the crucible tube, the upper mold part and assembled crucible may be pivoted to an angular inverted position with the hinged cover on the crucible dropping clear of the inverted top of the crucible. In this manner the normally downwardly facing mold surface of the upper mold part is positioned for inspection and cleaning, and the communicating top mold and crucible chamber can readily be cleaned by inserting a tool downwardly through the now convenient and exposed passages. The top of the handle is provided with a grip which enables the jig to be moved and positioned readily and, which may actually act as a cane to facilitate the bending or stooping motion required when inserting the cable or parts to be welded.
Another aspect of the present invention is the two part mold for the welding of relatively thick heavy crossing members such as cable in what is known as a lapped or cross connection. These connections are frequently used to form grids in ditches or cramped or inconvenient locations. With a horizontally split mold with interfitting parts having in effect a parting surface at two different elevations, such lapped or cross or grid connections can much more easily be made. Diagonal sleeving and more uniform mold block size also make the molds easier to make and less costly while increasing their service life.
To the accomplishment of the foregoing and related ends the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, of but a few of the various ways in which the principles of the invention may be employed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation of a jig and mold set prior to assembly in accordance with the present invention;
FIG. 2 is an elevation of the jig alone as seen from the right-hand side of FIG. 1;
FIG. 3 is a perspective view of the jig;
FIG. 4 is an elevation like FIG. 2, but with the molds assembled and closed;
FIG. 5 is a side elevation showing the mold parts partially open;
FIG. 6 is a similar view showing the mold parts fully open;
FIG. 7 is a view similar to FIG. 6 but showing the crucible and upper mold part inverted for cleaning;
FIG. 8 is an exploded view like FIG. 6 but showing the crucible unlocked and disassembled;
FIG. 9 is a somewhat enlarged fragmentary axial elevation of the pivot broken away and in section;
FIG. 10 is an enlarged section through the upper toggle pivot as seen from the line 10--10 of FIG. 6;
FIG. 11 is a corner elevation of a mold and crucible set for welding crossing members;
FIG. 12 is a corner elevation of the mold set as seen from the right-hand side of FIG. 11;
FIG. 13 is a plan view of the bottom mold at the parting surface as seen from the line 13--13 of FIG. 11;
FIG. 14 is a similar plan view of the upper mold as seen from the lines 14--14 of FIG. 11; and
FIGS. 15, 16 and 17 are perspective exploded views of other typical mold sets of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIGS. 1-8, there is illustrated a jig shown generally at 20 in accordance with the present invention which is designed to support and manipulate a refractory mold set shown generally at 21. As illustrated, the mold set comprises a crucible 23 having a hinged lid 24, and upper mold part 25, and a lower mating mold part 26. The mold parts and crucibles are made typically out of ceramic or graphite blocks with the various internal passages and chambers machined. The details of a mold set for forming lapped or cross welds are shown for example in FIGS. 11-14 while other mold configurations are shown in FIGS. 15-17. The actual configuration of such molds will be described subsequently.
The crucible and both mold parts are provided with horizontally extending fairly deep blind holes which receive paired studs projecting from the jig 20. As best seen in FIGS. 2 and 3, the studs 28 and 29 on which the lower mold part 26 is mounted project from plate 30 mounted on base 31. The upper mold part is mounted on studs 33 and 34 projecting from plate 35 mounted on crucible guide bar 36. The crucible 23 is mounted on studs 38 and 39 extending from plate 40 mounted on crucible tube 42 which telescopes over the crucible guide bar 36.
Also, as seen perhaps more clearly in FIGS. 2, 3 and 4, each of the plates 30, 35 and 40 is provided with an angle bracket seen at 44, 45 and 46, respectively, which accommodate thumb screws 47, 48 and 49 which enter relatively shorter holes in the side walls of the respective mold parts and crucible. With the thumb screws retracted, the mold parts and crucible are placed on the studs and properly seated. The thumb screws will not enter the relatively smaller holes unless the mold parts are properly seated. When the thumb screws are tightened, the mold parts are locked to the respective frames of the jig. In order to assure that the mold parts and crucible are assembled as they should be, the spacing of the studs and the receiving holes may vary slightly for each part.
In FIGS. 4-8, the mold parts are shown assembled to the jig. The figures illustrate the various movements and positions the mold parts and crucible may achieve with the present invention.
Referring back to FIGS. 1, 3 and 4, it will be seen that the base 31 includes a rectangular plate 50 which at each corner is provided with triangular barbed legs 51. Secured to the base and projecting upwardly from one edge thereof is an upwardly projecting tubular handle or post 52 which upwardly terminates in hand grip 53. The hand grip is at approximately the height of the top of a tall cane or approximately waist height of the user. The handle 52 and the base 31 are secured together and form an integral fixed unit and it is to the base that the lower mold part 26 is secured.
Telescoped on the handle 52 is a sliding tubular carriage or elevator 55. The tubular slide or carriage is moved vertically along the handle by a toggle mechanism shown generally at 57. This toggle mechanism is perhaps best illustrated in FIG. 3. Secured to and projecting from the handle near the grip 53 is an upper link clevis 60. A similar lower link clevis 61 is secured to the carriage or slide 55. Pivoted to the upper link clevis 60 is a lever handle 62 which includes an outwardly offset portion 63 terminating in hand grip 64. Pivoted to the link clevis 61 is an adjustment screw 66 threaded into the bight portion 67 of clevis 68. The two legs 69 and 70 of the clevis are pivoted to the lever handle 62 as shown at 72. The pivot 72 is shown in more detail in FIG. 10 and will be hereinafter described. In any event, by pulling the handle 62 away from the post 52 as seen, for example, in FIGS. 5 and 6, the slide or carriage 55 may be moved upwardly. When pushed back to the position seen in FIGS. 1 or 3, for example, pivot 72 moves over center between the upper and lower link clevis pivots locking the slide or carriage in the down position.
Referring now additionally to FIG. 9, it will be seen that the slide or elevator 55 at its lower end is provided with a pivot hub 74. The hub is simply welded to the side of the elevator as seen in FIG. 9 and accommodates a pin 75 which projects from bracket 76 which is secured to the crucible guide bar 36. The plate 35 from which the studs supporting the upper mold part 25 project also is secured to the crucible guide bar 36 as illustrated. The crucible guide tube 42 to which the plate 40 and crucible support are secured, telescopes over the upper end 77 of the crucible guide bar as seen more clearly in FIG. 8. The pivot 74-75 has stops limiting the pivot angle to approximately 300° to extend from a full upright position as seen in FIGS. 1-6 to the position seen in FIG. 7. It is noted that the pivot is offset both from the crucible guide 36 and the elevator 55 so that when the crucible guide is in a vertical or upright position, it is aligned with the vertical post or handle 52 and is directly in front of it as seen in FIG. 2. The upright or vertical alignment stop is seen at 78 in FIG. 2.
The crucible tube and guide, and thus the crucible and upper mold part are held together by a quick acting toggle shown generally at 79. The crucible tube 42 includes an angled handle 80 at its top and a hook 81 is secured to the side of the crucible tube. The hook provides a rounded seat for the rounded lower end 82 of toggle handle 83. The toggle handle is pivoted between the legs 84 and 85 of toggle clamp clevis 86. An adjustment screw 87 is threaded through the bight portion of the clevis and a jam nut 88 locks the adjustment in place. The adjustment screw is pivoted at 89 to link clevis 90 projecting from the bracket 76 as seen in FIG. 9. With the crucible supported by the crucible tube, and the upper mold supported by the crucible guide, the crucible tube is telescoped over the crucible guide and the toggle mechanism will lock the crucible to the top of the upper mold simply by pressing the handle 83 toward the crucible tube as seen in FIG. 2. The rounded lower end of the handle acts as a pivot and permits the upper pivot to rock over the point of contact between the lower end of the handle and the inside or seat of the hook. The clamp can be released simply by pulling the handle 83 away from the crucible tube and the handle and clevis will simply drop away.
Referring now to FIG. 10, it will be seen that the pivot 72 is formed about a tubular rivet 91 which extends through the two legs 69 and 70 of the clevis with the handle 62 therebetween. Positioned on each side of the handle within the pivot are Belleville washers shown at 92 and 93 which create pressure at the pivot and which act as a friction or drag brake for the toggle system. Accordingly, if the operator moves the upper toggle 57 anywhere from the closed position seen in FIG. 4 to the full open position seen in FIG. 6, the carriage or elevator 56 including the crucible and upper mold supported thereby will remain exactly where it is released. Manual movement of the handle 63 is required to move the parts both up and down.
Operation
Initially the mold set seen in FIG. 1 will be assembled to the jig. As a matter of convenience, it is easier to assembly the mold components when the jig is opened and when the crucible tube 42 is separated from the crucible guide bar 36 as seen in FIG. 8. In any event, the mold components are properly assembled and seated on the base for the lower mold part, the crucible guide bar for the upper mold part, and the crucible tube for the crucible itself. The crucible tube with the crucible in place as seen in FIG. 8 is then telescoped over the crucible guide bar 36 and the toggle mechanism is employed to lock the crucible to the upper mold part as seen in FIG. 6. With the molds open as seen in FIG. 6, the operator may manipulate the entire jig simply by grasping the top handle 53. The grasping of the handle 53 moves the jig as a whole and not any of the mold parts with respect to each other. The operator using the handle may then place the jig in the bottom of a trench, for example, driving the legs or barbed feet 51 of the base into the soil. Then, using the handle 53 as a cane or aid, the operator then simply bends over to place an object to be welded in the proper sleeving of the bottom mold part. Before this is done, the operator may position the upper mold part and crucible at any elevation with respect to the bottom mold part. Normally simply sufficient clearance is obtained to insert the parts to be welded. Such position would be seen in FIG. 5.
If the mold parts are not quite properly positioned to receive the parts to be welded, the operator may readily reposition the jig simply by elevating it and moving it to another location. When the base barb legs are driven into the ground, the jig will stand in an upright position. If necessary, the operator may use both hands to position the parts to be welded. As the elevator moves downwardly, the lower end of the crucible guide bar 36 telescopes into a guide socket in the base 31 as seen in FIG. 1. With the parts in proper position, the mold parts are then closed simply by moving the toggle handle 63 in a clockwise direction as seen in FIG. 5. This moves the elevator 55 downwardly to close the mold parts on the parts to be welded. When the mold parts are properly closed on the parts to be welded as seen in FIG. 4, the operator charges the crucible with the exothermic material, closes the lid 24, and ignites the material. The igniting material creates the exothermic reaction which moves downwardly through the mixture melting a small steel disk at the bottom of the crucible permitting the molten metal to flow through a tap hole into the weld cavity surrounding the parts to be welded.
After the molten metal has sufficiently cooled, the operator then moves the handle 63 in a counterclockwise direction as in FIG. 5 which then elevates the upper mold part and crucible as a unit. Continued movement of the handle 63 to the position seen in FIG. 6 fully opens the mold parts. When the operator releases the handle, it will remain in any position. In the full open position, the operator may then grasp handle 80 and invert the crucible and the upper mold part to the position seen in FIG. 7. It is noted that the cover 24 is hinged at 94 to the crucible, such hinge being parallel to the axis of the pivot and on the leading top edge of the crucible as it is pivoted to the FIG. 7 position. In this manner, the cover 24 will drop to the vertical position seen clear of the top 95 of the crucible. With the upper mold part and crucible in the inverted position seen, the normally bottom surface of the upper mold part is exposed and the operator may readily clean both the upper mold part and the crucible by inserting a tool downwardly through the tap hole so that the slag or debris cleaned drops through the enlarged top hole of the crucible offset from the upwardly directed mold surface of the bottom mold part 26. When the weld is completed and the mold parts properly cleaned, the jig with the mold parts attached may readily be transported to the next welding site and the process repeated. If for some reason the crucible needs to be detached or serviced otherwise, it can readily be detached from the jig as indicated in FIG. 8 simply by releasing the toggle handle 83.
Molds
Referring initially to FIGS. 11-14, there is illustrated a mold system for producing a lapped or cross connection, which connections are formed where one cable or conductor passes over the top of another, usually at right angles to each other. Such connections are widely employed in the formation of grids used for grounding purposes and are usually formed with each cable or conductor in a ditch.
The crucible 23 includes an interior upwardly opening chamber 96 which funnels into a vertically extending tap hole 97. In accordance with conventional practice, the top of the tap hole is closed with a small steel disk, for example, and the exothermic materials are placed in the chamber 96. When the weld is to be made, the exothermic material is ignited to create the exothermic reaction. The material may be ignited through a starting powder on top of the material by a flint gun, or the top of the crucible may contain a filter and the ignition may be by an electrical spark or fuse.
The exothermic reaction normally proceeds downwardly through the charge of material in the crucible to form the molten metal which melts the steel disk permitting molten metal to flow downwardly through the tap hole and into the weld chamber below, while the slag forms on top.
The weld chamber is shown generally at 99 and is formed by the mating upper and lower mold parts. The upper mold part includes a tap hole 101 slightly larger than and in alignment with the tap hole 97. The vertical hole 101 communicates with a riser chamber 102. The riser chamber 102 communicates with semi-cylindrical chambers 105 and 106 seen in FIG. 14 extending symmetrically on each side thereof. Such chambers 105 and 106 communicate with part receiving semi-circular sleeve recesses 107 and 108 which extend to the diagonal corners 109 and 110 of the upper mold part 25. It is noted that the chambers or recesses 107, 105, 106 and 108 are formed in a surface 112 of the upper mold part which is recessed with respect to the surfaces 113 and 114. The surface 112 is formed in a diagonally extending groove and the side walls of that groove indicated at 116 and 117 are slightly inclined.
Similarly, the upper surface of the bottom mold part seen in FIG. 13 includes a diagonally extending ridge having a surface 120 having an elevation higher than the surfaces 121 and 122. The transition between the two surface elevations is formed by rather steeply inclined surfaces 123 and 124. Aligned with the diagonally extending ridge are semi-circular recesses 128 and 129 which mate with the recesses 107 and 108, respectively, to form the sleeving around a cable or part to be welded.
Somewhat enlarged aligned semi-cylindrical recesses 130 and 131 form the opposite halves of the recesses 105 and 106, respectively. Such enlarged cylindrical recesses intersect with a transverse enlarged cylindrical cavity 134 which cuts through the middle of the ridge and which joins semi-cylindrical cavities 135 and 136 in the lower elevation surfaces 121 and 122, respectively. The recesses 135 and 136 mate with similar recesses 137 and 138 in the surfaces 113 and 114 of the upper mold part.
In order to assure the proper alignment of the complementary parting surfaces of the two mold parts, paired alignment pins or holes may be provided as indicated at 142 and 143. It is noted that the mold parts are generally square in horizontal section and aside from the parting surfaces at different elevations, are generally of the same height. This construction of the molds has a number of advantages. One of the advantages is that the sleeving seen at 128, 135, 129 and 136 in FIG. 13, and the mating surfaces in FIG. 14 are longer than they normally would be if the sleeving extended perpendicular to a side of the mold. Longer sleeving is obtained diagonally. Longer sleeving provides a better seal for the part to be welded, better support, and also less wear on the molds at the sleeving which forms the seal. Another advantage is the generally uniform overall dimension of the mold parts. This makes jigging and fixturing easier in the machines which are used to shape and cut the mold parts, resulting in higher speed production and lower cost.
Referring now to FIG. 15, there is illustrated a mold set which comprises upper and lower molds 150 and 151, respectively, for making a Tee splice or weld. The upper mold includes diagonally positioned axially aligned sleeving indicated at 152 and 153 which communicates with a central enlarged semi-circular cavity 154. Extending normal to the sleeving 152 and 153 is a further semi-circular sleeve 155 which extends from the intermediate corner of the mold to a semi-circular enlargement 156 which is axially normal to the enlargement 154. The top of the Tee cavity thus formed is provided with a riser chamber 157 communicating with the tap hole of the crucible.
The bottom mold part includes axially aligned diagonal sleeving 160 and 161 both of which communicate with somewhat enlarged cylindrical semi-circular chamber 162. Sleeving 164 extends from the intermediate corner to communicate with enlarged semi-cylindrical cavity 165 in communication with the cavity 162 forming the Tee weld chamber. When the parts are assembled, a conductor in the sleeving formed by the two mold parts at 155 and 164 may be welded to a conductor extending through the diagonal aligned sleeving. It will be appreciated that the mold of FIG. 15 may make a Tee splice or weld from either two parts or three parts. If three parts, the ends of all three parts must be positioned properly within the weld chamber.
In FIG. 16, there is illustrated upper and lower mold parts 168 and 169, respectively. The mold parts may be utilized simply to form a cable or like conductor butt splice weld. The upper mold part includes diagonally extending sleeving 172 and 173 communicating with central weld chamber 174 which in turn is in communication with riser chamber 175 communicating with the tap hole of the crucible 23. The top surface of the bottom mold 169 includes mating sleeving 177 and 178 communicating with the enlarged weld chamber 179. When the parts are positioned in and clamped by the sleeving and properly project into the weld chamber, a butt splice electrical connection can readily be made.
Although the embodiments of FIGS. 11-16 illustrate diagonal sleeving, it will be appreciated that the molds may be constructed so that the sleeving runs perpendicular to the sides of the mold rather than through the diagonal corners. One such mold set is illustrated in FIG. 17. The mold set seen in FIG. 17 may be employed to weld two parallel conductors together or may be employed to butt weld conductors together and conjoin such conductors concurrently. The upper mold 182 includes semi-circular sleeving extending perpendicular to the side of the mold communicating with weld chamber 185. On the opposite side of the weld chamber, sleeving sections 186 and 187 are in axial alignment with the opposite respective sections 183 and 184. The weld chamber includes an upwardly projecting riser chamber 188 in communication with the tap hole of the crucible 23.
The bottom mold part 183 includes semi-circular sleeving sections 190 and 191 communicating with enlarged weld chamber 192. Such sleeving sections are in axial alignment with sleeving sections 193 and 194 on the opposite side of the weld chamber. As indicated, the mold set depicted in FIG. 17 may weld together parallel conductors or butt weld concurrently one or two different conductors.
It is noted that FIGS. 15-17 illustrate pilot pins 196 and mating pilot holes 197. Such also illustrate the holes 198 in the mold parts and crucible for receiving the thumb screws 47, 48 and 49. The mold sets illustrated in FIGS. 11-17 are simply examples of molds which may be used with the jig and method of the present invention.
It can now be seen that there is provided welding apparatus which can quickly and conveniently be opened and closed and cleaned. With the simplified toggle mechanism 79, the crucible and upper mold part are mounted together and maintain tight contact. However, the toggle is quickly released to allow the crucible section to be removed independently and rapidly, and without being handled directly. When the jig is open by the toggle 57, the crucible and the upper mold part are pivotable for inversion to hold in proper position the parts for quick cleaning of the slag and other debris which remains after the exothermic reaction. This avoids a slow and uncomfortable holding of the individual parts for cleaning. Moreover, the jig when opened maintains the mold parts in the released position without slippage which is common with conventional handle clamps or toggle frames. The vertical configuration of the jig allows work to be performed down in narrow trenches and there are no horizontally projecting handle clamps which would interfere with this process and require wider trenches. The jig makes the connection more easily and the vertically extending handle may even be used as a cane to enable the installer to position the conductors with one hand while supporting himself with the other. Moreover, the frame or base is such that it can be mounted in soil or other surfaces without movement and will remain erect. While the mold parts may quickly be changed, it is even easier to change out the crucible for a different capacity or type of connection.
The three piece mold sets useful with the jig make the formation of lapped or cross connections much easier and more economical. Such molds also have longer service lives and may be made more economically.
Although the invention has been shown and described with respect to certain preferred embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification. The present invention includes all such equivalent alterations and modifications, and is limited only by the scope of the claims. | 4y
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This is a division of application Ser. No. 08/417,317 filed Apr. 5, 1995, now U.S. Pat. No. 5,614,625.
SUMMARY OF THE INVENTION
The present invention is concerned with hydroxamic acid derivatives with tricyclic substitution.
The hydroxamic acid derivatives provided by the present invention are compounds of the general formula ##STR2## wherein R 1 represents cyclopropyl, cyclobutyl, cyclopentyl or cyclohexyl;
R 2 represents a saturated 5- to 8-membered monocyclic or bridged N-heterocylic ring which is attached via the N atom and which N-heterocylic ring, when it is monocyclic, optionally contains NR 4 , O, S, SO or SO 2 as a ring member and/or is optionally substituted on one or more C atoms by hydroxy, lower alkyl, lower alkoxy, oxo, ketalized oxo, amino, mono(lower alkyl)amino, di(lower alkyl) amino, carboxy, lower alkoxycarbonyl, hydroxymethyl, lower alkoxymethyl, carbamoyl, mono(lower alkyl)-carbamoyl, di(lower alkyl)carbamoyl or hydroxyimino;
R 3 represents a 5- or 6-membered N-heterocyclic ring which (a) is attached via the N atom, (b) optionally contains N, O and/or S, SO or SO 2 as an additional ring member, (c) is substituted by oxo on one or both C atoms adjacent to the linking N atom and (d) is optionally benz-fused or optionally substituted on one or more other C atoms by lower alkyl or oxo and/or on any additional N atom(s) by lower alkyl or aryl;
R 4 represents hydrogen, lower alkyl, aryl, aralkyl or a protecting group;
m stands for 1 or 2; and
n stands for 1-4;
and pharmaceutically acceptable salts thereof.
The compounds of formula I possess valuable pharmacological properties. In particular, they are collagenase inhibitors and can be used in the control or prevention of degenerative joint diseases such as rheumatoid arthritis and osteoarthritis or in the treatment of invasive tumours, atherosclerosis or multiple sclerosis.
Objects of the present invention are the compounds of formula I and their pharmaceutically acceptable salts per se; a process for manufacture of said compounds and salts; intermediates useful in said process; and the use of said compounds and salts in the control or prevention of illnesses or in the improvement of health, especially in the control or prevention of degenerative joint diseases or in the treatment of invasive tumours or atherosclerosis.
DETAILED DESCRIPTION OF THE INVENTION
The hydroxamic acid derivatives provided by the present invention are compounds of the general formula ##STR3## wherein R 1 , R 2 , R 3 m and n are hereinbefore described.
As used in this Specification, the term "lower alkyl", alone or in combination, means a straight-chain or branched-chain alkyl group containing a maximum of six carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec.butyl, isobutyl, tert.butyl, n-pentyl, n-hexyl and the like. The term "lower alkoxy", alone or in combination, means a straight-chain or branched-chain alkoxy group containing a maximum of six carbon atoms, such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, tert.butoxy and the like. The term "aryl" means an unsubstituted or substituted aromatic group, such as phenyl, which is optionally substituted by, for example, lower alkyl, lower alkoxy and/or halogen, i.e. fluorine, chlorine, bromine or iodine. As examples of aryl groups that may be used in accordance with this invention, p-tolyl, p-methoxyphenyl, p-chlorophenyl, and the like can be enumerated. The term "aralkyl" means a lower alkyl group as hereinbefore defined in which one or more hydrogen atoms is/are replaced by an aryl group as hereinbefore defined. Any aralkyl can be used in accordance with this invention, such as benzyl and the like. A ketalized oxo group can be any ketal compound containing a carbon with two oxygen atoms, for example, ethylenedioxy.
A protecting group denoted by R 4 can be any conventional protecting group, e.g. as known in peptide chemistry, such as benzyloxycarbonyl, tert.butoxycarbonyl, acetyl and the like.
As used in this Specification, N-heterocyclic denotes compounds having one or more ring structures, wherein at least one ring structure is represented by an N atom. The term "monocyclic N-heterocyclic" denotes an N-heterocyclic group having one ring structure. As used herein the term "bridged N-heterocyclic ring" denotes a heterocyclic ring structure containing at least one N atom; which is fused or bridged to at least one additional ring structure.
Examples of monocyclic N-heterocyclic rings denoted by R 2 are 1-pyrrolidinyl, piperidino, 1-piperazinyl, 4-aryl-1-piperazinyl, hexahydro-1-pyridazinyl, morpholino, tetrahydro-1,4-thiazin-4-yl, tetrahydro-1,4-thiazin-4-yl 1-oxide, tetrahydro-1,4-thiazin-4-yl 1,1-dioxide, thiazolidin-3-yl, hexahydroazepino and octahydroazocino which can be substituted in the manner given earlier; for example 2-(methylcarbamoyl)-1-pyrrolidinyl, 2-(hydroxymethyl)-1-pyrrolidinyl, 4-hydroxypiperidino, 2-(methylcarbamoyl)piperidino, 4-hydroxyiminopiperidino, 4-methoxypiperidino, 4-methyl-1-piperazinyl, 4-phenyl-1-piperazinyl, 1,4-dioxa-8-azaspiro 4.5!decan-8-yl, hexahydro-3-(methylcarbamoyl)-2-pyridazinyl, hexahydro-1-(benzyloxycarbonyl)-2-pyridazinyl, 5,5-dimethyl-4-methylcarbamoyl-thiazolidin-3-yl and 5,5-dimethyl-4-propylcarbamoyl-thiazolidin-3-yl.
Examples of bridged N-heterocyclic rings denoted by R 2 are 5-azabicyclo 2.1.1!hexane, 3-azabicyclo 3.1.1!heptane, 7-azabicyclo 2.2.1!-heptane, 3-azabicyclo 3.2.1!octane, 2-azabicyclo 3.2.2!nonane and 3-azabicyclo 3.2.2!nonane.
Examples of N-heterocylic rings denoted by R 3 are rings of the formulae: ##STR4## in which R 5 and R 6 each represent hydrogen or together represent an additional bond or the remainder of a fused benzene ring;
R 7 represents hydrogen, lower alkyl or aryl; and.
X represents --CO--, --CH 2 --, --CH(lower alkyl)--, --C(lower alkyl) 2 --, --NH--, --N(lower alkyl)-- or --O--; or, when R 7 represents lower alkyl and X represents --N(lower alkyl)--, the lower alkyl groups can be joined to form a 5-, 6- or 7-membered ring;
R 8 represents hydrogen, lower alkyl or aryl;
R 9 and R 10 each represent hydrogen or lower alkyl;
Y represents --O--, --NH-- or --N(lower alkyl)--; and
Z represents S; SO or SO 2 ;
wherein lower alkyl and aryl is as hereinbefore defined.
Examples of such N-heterocyclic ring denoted by R 3 are 2-oxo-1-pyrrolidinyl, 2,5-dioxo-1-pyrrolidino; phthalimido 1,2-dimethyl-3,5-dioxo-1,2,4-trizolidin-4-yl, 3-methyl-2,5-dioxo-1-imidazolidinyl, 3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl, 2-methyl-3,5-dioxo-1,2,4-oxadiazol-4-yl, 3-methyl-2,4,5-trioxo-1-imidazolidinyl, 2,5-dioxo-3-phenyl-1-imidazolidinyl, 2,6-dioxopiperidino, 5,5-dimethyl-2,4-dioxo-3-oxazolidinyl and hexahydro-1,3-dioxopyrazolo 1,2-a! 1,2,4!triazol-2-yl.
One group of preferred compounds of formula I comprises those in which R 2 represents 1-pyrrolidinyl, piperidino, 4-aryl-1-piperazino, morpholino, tetrahydro-1,4-thiazin-4-yl, tetrahydro-1,4-thazin-4-yl 1,1-dioxide, thiazolidin-3-yl, hexahydroazepino or octahydroazocino optionally substituted on one or more C atoms by hydroxy, lower alkyl, lower alkoxy, ketalized oxo or mono(lower alkyl)-carbamoyl. The preferred R 2 is piperidino which is optionally substituted by hydroxy, particularly 4-hydroxypiperidino. Another preferred R 2 is 3-azabicyclo 3.2.2!nonane. Also preferred are compounds of formula I in which R 3 represents a group of formula (b), (c), or (h). When R 3 represents a group of formula (c), R 7 is preferably lower alkyl and X is preferably --C(lower alkyl) 2 --, particularly 3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl. Preferably, m and n both stand for 1.
The most preferred compounds of formula I are:
1- 3-cyclopropyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!piperidine,
1- 3-cyclopropyl-2-(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-4-piperidinol,
3- 3-cyclopropyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-3-azabicyclo 3.2.2!nonane,
1- 3-cyclobutyl-2(R)- 1 (R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!piperidine,
1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-4-piperidinol,
3- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-3-azabicyclo 3.2.2!nonane,
1- 3-cyclopentyl-2 (R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-4-piperidinol,
3- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2- 3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-3-azabicyclo- 3.2.2!nonane and
1- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!piperidine.
Other preferred compounds of formula I hereinbefore are:
1- 3-cyclohexyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!piperidine,
4- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!tetrahydro-1,4-thiazine,
4- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!tetrahydro-1,4-thiazine S,S-dioxide,
4- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!tetrahydro-1,4-thiazine,
4- 3-cyclohexyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!tetrahydro-1,4-thiazine,
3- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-5,5-dimethyl-N-propyl-4(R)-thiazolidinecarboxamide,
4- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!morpholine,
3- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-N,5,5-trimethyl-4(R)-thiazolidinecarboxamide,
4- 3-cyclobutyl-2(R)- 1(R or S)-hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-4-phenylpiperazine,
4- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!morpholine,
1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!pyrrolidine,
8- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-1,4-dioxa-8-azaspiro 4,5!decane,
1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-4-methoxypiperidine,
1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!octahydroazocine,
1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(5,5-dimethyl-2,4-dioxo-3-oxazolidinyl)ethyl!propionyl!piperidine,
1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-hexahydroazepine,
1- 3-cyclobutyl-2(R)- 2-(hexahydro-1,3-dioxopyrazolo 1,2-a! 1,2,4!triazol-2-yl)-1(R or S)-(hydroxycarbamoyl)ethyl!propionyl!piperidine and
1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-phthalimidoethyl!propionyl!piperidine
The compounds of formula I form pharmaceutically acceptable salts with bases such as alkali metal hydroxides (e.g. sodium hydroxide and potassium hydroxide), alkaline earth metal hydroxides (e.g. calcium hydroxide and magnesium hydroxide), ammonium hydroxide and the like. The compounds of formula I which are basic form pharmaceutically acceptable salts with acids. As such salts there come into consideration not only salts with inorganic acids such as hydrohalic acids (e.g. hydrochloric acid and hydrobromic acid), sulphuric acid, nitric acid, phosphoric acid etc, but also salts with organic acids such as acetic acid, tartaric acid, succinic acid, fumaric acid, maleic acid, malic acid, salicylic acid, citric acid, methanesulphonic acid, p-toluenesulphonic acid etc.
The compounds of formula I contain at least two asymmetric carbon atoms and can accordingly exist as optically active enantiomers, as diastereoisomers or as racemates. The present invention is intended to embrace all of these forms.
According to the proess provided by the present invention, the compounds of formula I and their pharmaceutically acceptable salts are manufactured by
(a) reacting an acid of the general formula ##STR5##
wherein R 1 , R 2 , R 3 , m and n have the significance given earlier, with a compound of the general formula.
H.sub.2 N--OZ (III)
wherein Z represents hydrogen, tri(lower alkyl)silyl or diphenyl(lower alky)silyl,
and, where required, cleaving off any diphenyl(lower alkyl)silyl group present in the reaction product, or
(b) catalytically hydrogenating a compound of the general formula ##STR6##
wherein R 1 , R 2 , R 3 , m and n have the significance given earlier and Bz represents benzyl, and, if desired, converting a compound of formula I obtained into a pharmaceutically acceptable salt.
The reaction of an acid of formula II with a compound of formula III in accordance with embodiment (a) of the process can be carried out in a known manner. For example, an acid of formula II can be reacted with a compound of formula III in an inert organic solvent such as dichloromethane, dimethylformamide or the like using 1-hydroxybenzotriazole in the presence of a condensation agent such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride at about 0° C. to about room temperature. Alternatively, an acid of formula II can be converted into the corresponding acid chloride (e.g. using oxalyl chloride) and the acid chloride can then be reacted with a compound of formula III. Preferred compounds of formula III are those in which Z represents tert.butyldimethylsilyl or tert.butyldiphenylsilyl. When a compound of formula III in which Z represents tri(lower alkyl)silyl is used, this group is cleaved off during the reaction and working-up, and a compound of formula I is obtained directly. On the other hand, when a compound of formula III in which Z represents diphenyl(lower alkyl)silyl is used, this group remains in the reaction product and must subsequently be cleaved off in a known manner, for example by means of fluoride ions.
The catalytic hydrogenation of a compund of formula IV in accordance with embodiment (b) of the process can be carried out in a manner known per se; for example in an inert organic solvent using hydrogen in the presence of a noble metal catalyst. Suitable inert organic solvents are, for example, lower alkanols such as methanol, ethanol, etc. With respect to the catalyst, this can be, for example, a platinum, palladium or rhodium catalyst which can be supported on a suitable carrier material. Palladium-on-charcoal is the preferred catalyst. The temperature and pressure are not critical, although for convenience the catalytic hydrogenation is preferably carried out at room temperature and under atmospheric pressure.
Compounds of formula I can be converted into pharmaceutically acceptable salts by treatment with bases and basic compounds of formula I can be converted into pharmaceutically acceptable salts by treatment with acids. Such treatments can be carried out in a conventional manner.
The acids of formula II which are used as starting materials in embodiment (a) of the process are novel and form a further object of the present invention.
The acids of formula II can be prepared, for example, as illustrated in the following Reaction Scheme in which R 1 , R 2 , R 3 , m and n have the significance given earlier, Bz represents benzyl and tBu represents tert-butyl: ##STR7##
Having regard to the foregoing Reaction Scheme, the individual steps thereof can be carried out according to methods known per se. Thus, in the first step, an amino acid of formula V, which can be obtained according to the procedure described by Chenault H. K, Dahmer J. and Whitesides G. M., J.Am. Chem. Soc. 1989, 111, 6354-6364, is converted by treatment with sodium nitrite in the presence of concentrated sulphuric acid into a hydroxy acid of formula VI which is subsequently reacted with benzyl bromide in the presence of an organic base, e.g. a trialkylamine such as triethylamine, into a corresponding benzyl ester of formula VII. The latter is then activated, e.g. by reaction with trifluoromethanesulphonic anhydride, and treated with benzyl tert-butyl malonate in the presence of a strong base, e.g. an alkali metal hydride such as sodium hydride, to give a compound of formula VIII. Treatment of the latter with a strong base, e.g. an alkali metal hydride such as sodium hydride, and reaction with a compound of formula IX yields a dibenzyl tert-butyl butanetricarboxylate of formula X which is then debenzylated by catalytic hydrogenation, e.g. in the presence of palladium catalyst such as palladium-on-charcoal, to give a tert-butyl dihydrogen butanetricarboxylate of formula XI. Decarboxylation of this compound, e.g. by heating in toluene with triethylamine, which may be carried out in situ, yields a tert-butyl hydrogen succinate of formula XII which is condensed with a cyclic amine of formula XIII, e.g. according to the acid chloride method or using 1-hydroxybentriazole in the presence of a condensation agent such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, to give a compound of formula XIV which is deprotected (e.g. by treatment with trifluoroacetic acid) to give an acid of formula H.
The compounds of formula IV which are used as starting materials in embodiment (b) of the process are novel and form a further object of the present invention.
The compounds of formula IV can be prepared, for example, by reacting an acid of formula II with O-benzylhydroxylamine. This reaction can be carried out in a known manner, for example in an inert organic solvent such as dichloromethane or dimethylformamide using 1-hydroxybenzotriazole in the presence of a condensation agent such as 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride.
The remaining compounds which are used as intermediates or reactants in the manufacture of the compounds of formula I are known compounds or analogues of known compounds which can be prepared in a similar manner to the known compounds.
As mentioned earlier, the compounds of formula I and their pharmaceutically acceptable salts are collagenase inhibitors. The in vitro collagenase inhibiting activity of the present compounds and salts can be demonstrated by known means using collagenase obtained from a culture of human synovial fibroblasts according to the method of Dayer J-M et al., Proc. Natl. Acad. Sci. USA (1976), 73 945, following activation of the pro-collagenase in the conditioned medium by treatment with trypsin. Collagenase activity can be measured using 14 C-acetylated collagen type I from rat tail tendons as the substrate and employing the microtitre plate assay method of Johnson-Wint, B, Anal. Biochem. (1980), 104, 175. The IC 50 measured by this assay is a measure of the collagenase inhibiting activity and is that concentration of a compound or salt of the present invention in the enzyme digestion which reduces substrate cleavage and solubilization to 50% of that achieved by the enzyme alone. An IC 50 measured means by this assay that the compound or salt has collagenase inhibiting activity. This is true regardless of the value of the IC 50 .
The results obtained in the foregoing test with representative compounds and salts of this invention are compiled in Table I hereinafter:
TABLE I______________________________________Product of Example No. IC.sub.50 (nM)______________________________________2 18.04 7.05 2.57 6.59 8.516 4.117 2.3523 34.0______________________________________
The compounds of formula I and their pharmaceutically acceptable salts can be used as medicaments, for example in the form of pharmaceutical preparations. The pharmaceutical preparations can be administered orally, e.g. in the form of tablets, coated tablets, dragees, hard and soft gelatine capsules, solutions, emulsions or suspensions. However, they can also be administered rectally, e.g. in the form of suppositories, or parenterally, e.g. in the form of injection solutions.
For the manufacture of pharmaceutical preparations the compounds of formula I and their pharmaceutically acceptable salts can be formulated with therapeutically inert, inorganic or organic carriers. Lactose, corn starch or derivatives thereof, talc, stearic acid or its salts can be used, for example, as such carriers for tablets, coated tablets, dragees and hard gelatine capsules. Suitable carriers for soft gelatine capsules are, for example, vegetable oils, waxes, fats, semi-solid and liquid polyols and the like. Depending on the nature of the active ingredient no carriers are, however, generally required in the case of soft gelatine capsules. Suitable carriers for the manufacture of solutions and syrups are, for example, water, polyols, saccharose, invert sugar, glucose and the like. Suitable carriers for the manufacture of injection solutions are, for example, water, alcohols, polyols, glycerine, vegetable oils and the like. Natural and hardened oils, waxes, fats, semi-liquid polyols and the like are suitable carriers for the manufacture of suppositories.
The pharmaceutical preparations can also contain preservatives, stabilizers, wetting agents, emulsifiers, sweeteners, colorants, flavorants, salts for adjustment of the osmotic pressure buffers coating agents or antioxidants.
Medicaments containing a compound of formula I or a pharmaceutically acceptable salt thereof and a therapeutically acceptable carrier as well as a process for the manufacture of such medicaments are also objects of the present invention. This process comprises mixing a compound of formula I or a pharmaceutically acceptable salt thereof with a therapeutically inert carrier material and bringing the mixture into a galenical administration form.
As mentioned earlier, the compounds of formula I and their pharmaceutically acceptable salts can be used in the control or prevention of illnesses, especially in the control or prevention of degenerative joint diseases or in the treatment of invasive tumours, atherosclerosis or multiple sclerosis. The dosage can vary within wide limits and will, of course, be adjusted to the individual requirements in each particular case. In general, in the case of administration to adults, a daily dosage of from about 5 mg to about 30 mg, preferably from about 10 mg to about 15 mg, should be appropriate, although the upper limit may be exceeded when this is found to be expedient. The daily dosage can be administered as a single dosage or in divided dosages.
The following Examples illustrate the present invention in more detail. In these Examples all temperatures are given in degrees Celsius.
EXAMPLE 1
A solution of 0.575 g of 1- 2(R)- 1(R or S)-(benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopropylpropionyl!piperidine (diastereoisomer 1) in 10 ml of ethanol was hydrogented in the presence of 0.4 g of 5% palladium-on-charcoal catalyst for 6 hours. The catalyst was removed by filtration and the solution was evaporated. The residue was purified by flash chromatography on silica gel using dichloromethane/methanol (96:4) for the elution to give 0.37 g of 1- 3-cyclopropyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-propionyl!piperidine (diastereoisomer 1) in the form of a white foam.
nmr (MeOD): 3.78-3.64 (m, 3H); 3.62 (dd, 1H, J=15,8); 3.49-3.41 (m, 1H); 3.39 (dd, 1H, J=15,5); 3.33-3.27 (m, 1H); 2.95-2.87 (m, 1H); 2.83 (s, 3H); 174-146 (m, 7H); 1.33 (s, 3H); 1.31 (s, 3H); 1.20-1.13 (m, 1H); 0.61-0.50 (m, 1H); 0.44-0.33 (m, 2H); 0.06--0.05 (m, 2H); MS: 409 (M+H) + .
The starting material was prepared as follows:
(i) A solution of 4.9 g of 2(R)-amino-3-cyclopropylpropionic acid (prepared in a manner analogous to that described by Chenault H. K., Dahmer J. and Whitesides G. M. in J. Am. Chem. Soc. 1989, 111, 6354-6364) in 50 ml of water containing 4.05 ml of concentrated sulphuric acid was warmed to 45°. A solution of 10.5 g of sodium nitrite in 20 ml of water was added dropwise over 30 minutes. The solution was stirred at 45° for 4 hours and then cooled to room temperature. The solution was extracted with three 50 ml portions of ethyl acetate. The combined extracts were washed with water, and dried over anhydrous magnesium sulphate. The solvent was evaporated to leave 3.95 g of a yellow oil containing 3-cyclopropyl-2(R)-hydroxypropionic acid which was used in the next step without further purification.
Rf dichloromethane/methanol (9:1)!=0.65.
(ii) A solution of 3.95 g of the product from (i) in 50 ml of ethyl acetate was treated with 5.32 ml of triethylamine and 3.8 ml of benzyl bromide. The mixture was stirred and heated under reflux for 3 hours, then allowed to cool to room temperature overnight. The suspension was washed with 2M hydrochloric acid, water and saturated sodium chloride solution. After drying over anhydrous magnesium sulphate the solvent was evaporated. The residue was purified by flash chromatography on silica gel using hexane/ethyl acetate (2:1) for the elution to give 3.36 g of benzyl 3-cyclopropyl-2(R)-hydroxypropionate in the form of a yellow oil.
nmr (CDCl 3 ): 7.39-7.28 (m; 5H; 5.19 (d, 1H, J=14); 5.15 (d, 1H, J=14); 4.31-4.24 (m, 1H; 2.81 (br. d, IH); 1.69-1.54 (m, 2H); 0.87-0.74 (m, 1H; 0.45-0.34 (m, 2H); 0.08--0.07 (m, 2H).
(iii) A solution of 3.36 g of the product from (ii) and 1.49 ml of pyridine in 10 ml of dichloromethane was added dropwise to a solution of 3.07 ml of trifluoromethanesulphonic anhydride in 15 ml of dichloromethane at 0° over 30 minutes with stirring. The mixture was stirred at 0° for 2 hours and then washed with water and saturated sodium chloride solution. After drying over anhydrous magnesium sulphate the solvent is evaporated to give 5.37 g benzyl 3-cyclopropyl-2(R)-trifluoromethylsulphonyloxypropionate in the form of an orange oil which was used in the next step without further purification.
R f hexane/ethyl acetate (4:1)!=0.5.
(iv) A solution of 3.8 g of benzyl tert-butyl malonate in 50 ml of 1,2-dimethoxyethane was treated with 0.504 g of an 80% dispersion of sodium hydride in mineral oil. The mixture was stirred at room temperature for 30 minutes and then cooled to 0°. A solution of 5.37 g of the product from (iii) in 20 ml of dichloromethane was added drop-wise at 0°. The mixture was stirred at 0° for 2 hours and then left to warm to room temperature overnight. The solvent was evaporated and the residue was dissolved in ethyl acetate. The solution was washed with water and saturated sodium chloride solution. After drying over anhydrous magnesium sulphate the solvent was evaporated to give 6.54 g of 2,3-dibenzyl 3-tert-butyl 1-cyclopropyl-2(R),3(R,S),3-propanetricarboxylate as a 1:1 mixture of diastereoisomers in the form of an orange oil.
nmr (CDCl 3 ): 7.46-7.36 (m, 20H); 5.19-5.07 (m, 8.H); 3.89 (d, 1H, J=10); 3.85 (d, 1H, J=10) 3.37-3.26 (m, 2H); 1.68-1.52 (m, 2H); 1.52-1.38 (m, 2H); 1.41 (s, 9H); 1.39 (s, 9H); 0.79-0.63 (m, 2H); 0.49-0.38 (m, 4H); 0.12-0.07 (m, 4H).
(v) A solution of 6.4 g of the product from (iv) in 30 ml of 1,2-dimethoxyethane was treated with 0.446 g of an 80% dispersion of sodium hydride in mineral oil. The mixture was stirred at room temperature for 30 minutes. A solution of 3.84 g of 1-(bromomethyl)-3,4,4-trimethyl-2,5-imidazolinedione in 20 ml of 1,2-dimethoxyethane was added dropwise over 15 minute. The mixture was stirred at room temperature for 36 hours, the solvent was evaporated and the residue was dissolved in ethyl acetate and washed with water and saturated sodium chloride solution. After drying over anhydrous magnesium sulphate the solvent was evaporated. The residue was purified by flash chromatography on silica gel using hexane/ethyl acetate (7:3) and subsequently hexane/ethyl acetate (6:4) for the elution to give 6.4 g of 2,3-dibenzyl 3-tert-butyl 1-cyclopropyl-4-(3,4,4-trimethyl-2, 5-dioxo-1-imidazolidinyl)-2(R),3(R,S),3-butanetricarboxylate as a 1:1 mixture of diastereoisomers in the form of a clear oil.
nmr (CDCl 3 ): 7.47-7.28 (m, 20H); 5.31-5.03 (m, 8H); 4.32-4.18 (m, 4H); 3.19-3.15 (m, 1H); 3.16-3.12 (m, 1H); 2.86 (s, 6H); 2.00-1.90 (m, 1H); 1.89-1.79 (m, 1H); 1.64-1.49 (m, 1H) 1.48-1.38 (m, 1H); 1.37 (s, 12H); 1.36 (s, 9H); 1.32 (s, 9H); 0.9-0.8 (m, 2H); 0.41-0.3 (m, 4H); 0.15-0.05 (m, 2H); 0.04- -0.04 (m, 2H).
(vi) A solution of 3.0 g of the product from (v) in 30 ml of 2-propanol was hydrogenated in the presence of 0.3 g of 5% palladium on charcoal catalyst for 2 hours. The catalyst was removed by filtration and the solution was evaporated. The residue was re-evaporated from 20 ml toluene and then dissolved in 50 ml of toluene. The solution was treated with 0.693 ml of triethylamine and the mixture was heated under reflux for 2 hours. The solution was cooled to room temperature and washed with 2M hydrochoric acid, water and saturated sodium chloride solution. After drying over anhydrous magnesium suphate the solvent was evaporated to give 1.85 g of 4-tert-butyl hydrogen 2(R)-(cyclopropylmethyl)-3(R or S)- (3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)methyl!succinate as an approximately 6:1 mixture of diastereoisomers in the form of a yellow oil.
MS: 383 (M+H) + ;
R f dichloromethane/methanol (9:1)!=0.41.
(vii) A solution of 1.0 g of the product from (vi) in 10 ml of dichloromethane was cooled to 0° and treated in succession with 0.665 ml of N-ethylmorpholine, 0.481 g of 1-hydroxybenzotriazole and 0.602 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. The mixture was stirred at 0° for 30 minutes and then treated with 0.517 ml of piperidine. The solution was left to warm to room temperature and was stirred overnight. The solution was washed with 5% aqueous sodium hydrogen carbonate solution, 2M hydrochloric acid and saturated sodium chloride solution. After drying over anhydrous magnesium sulphate the solvent was evaporated to give 1.01 g of of 1- 2(R)- 1(R or S)-(tert-butoxycarbonyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopropylpropionyl!piperidine as an approximately 6:1 mixture of diastereoisomers in the form of a yellow gum.
MS: 450 (M+H) + ;
R f dichloromethane/methanol (95:5)!=0.51.
(viii) A solution of 1.0 g of the product from (vii) in 2 ml of trifluoroacetic acid was stirred at room temperature for 2.5 hours. The solvent was evaporated and the residue was re-evaporated from toluene. The residue was dissolved in diethyl ether and the solution was extracted with two portions of 5% aqueous sodium hydrogen carbonate solution. The combined extracts were acidified to pH 2 with concentrated hydrochloric acid and the product was extracted with two portions of dichloromethane. The combined organic extracts were washed with water and saturated sodium chloride solution and dried over anhydrous magnesium sulphate. The solvent was evaporated to give 0.634 g of a white foam containing 1- 2(R)- 1(R or S)-carboxy-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopropylpropionyl!piperidine as a 6:1 mixture of diastereoisomers which was used in the next step without further purification.
Rf dichloromethane/methanol (9:1)!=0.31.
(ix) A solution of 0.634 g of the product from (viii) in 10 ml of dichloromethane was cooled at 0°. The solution was treated in succession with 0.41 ml of N-ethylmorpholine, 0.296 g of 1-hydroxybenzotriazole and 0.371 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. The mixture was stirred at 0° for 30 minutes. A solution of 0.238 g of O-benzylhydroxylamine in 2 ml of dichloromethane was added. The mixture was left to warm to room temperature and was stirred overnight. The solution was washed with two portions of 5% aqueous sodium hydrogen carbonate solution and subsequently with 21M hydrochloric acid, water and saturated sodium chloride solution. After drying over anhydrous magnesium sulphate the solvent was removed by evaporation. The residue was purified by flash chromatography on silica gel using dichloromethane/methanol (98:2) for the elution to give 0.592 g of 1- 2(R)- 1(R or S)-(benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopropylpropionyl!piperidine (diastereoisomer 1) as a white foam.
nmr (MeOD): 7.45-7.31 (m, 5H); 4.87 (d, 1H, J=13); 4.79 (d, 1H, J=13); 3.78-3.65 (m, 3H); 3.63 (dd, 1H, J=15, 8); 3.53-3.45 (m, 1H); 3.44 (dd, 1H, J=15,5); 3.34-3.27 (m, 1H); 2.87 (s, 3H); 2.84-2.78 (m, 1H); 1.78-1.49 (m, 7H); 1.49-1.40 (m, 1H); 1.36 (s, 3H); 1.32, (s, 3H); 1.12-1.04 (m, IH); 0.61-0.50 (m, 1H); 0.48-0.37(m, 2H); 0.07- -0.06 (m, 2H). MS: 499 (M+H) + .
EXAMPLE 2
In a manner analogous to that described in the first paragraph of Example 1, from 0.391 g of 1- 2(R)- 1(R or S)-(henzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopropylpropionyl!-4-piperidinol (diastereoisomer 1), prepared in a manner analagous to that described in Example 1 (i)-(ix), there was obtained 0.33 g of 1- 3-cyclopropyl-2-(R)- 1 (R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-4-piperidinol (diastereoisomer 1) in the form of a white foam.
nmr (MeOD): 4.22-4.02 (m, 2H); 3.90-3.81 (m, 1H); 3.69-3.56 (m, 1H); 3.49-3.38(m, 2H); 3.37-3.18 (m, 2H); 3.11-3.01 (m, 1H); 2.97-2.86 (m, 1H); 2.83 (d, 3H, J=5); 2.01-1.78 (m, 2H); 1.68-1.36 (m, 3H); 1.33 (s, 3H); 1.31 (d, 3H, J=5); 1.24-1.13 (m, 1H); 0.62-0.50 (m, 1H); 0.49-0.33 (m, 2H); 0.09- -0.05 (m, 2H); MS: 425 (M+H) +
EXAMPLE 3
In a manner analogous to that described in the first paragraph of Example 1, from 0.822 g of 3- 2(R)- 1(R or S)-(benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopropyl!-3-azabicyclo 3.2.2!nonane-(diastereoisomer 1), prepared in a manner analagous to that described in Example 1 (i)-(ix), there was obtained 0.496 g of 3- 3-cyclopropyl-2(R), 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-3-azabicyclo 3.2.2!nonane (diastereoisomer 1) in the form of a white foam.
nmr (MeOD): 4.0-3.1(m, 5H); 3.48-3.31 (m, 2H); 2.96-2.86 (m, 1H); 2.82 (s, 3H); 2.14-2.03 (m,2H); 1.80-1.68 (m, 4H); 1.68-1.53(m, 5H); 1.32 (s, 3H); 1.31 (s, 3H); 1.21-1.12 (m, 1H), 0.64-0.52(m, 1H); 0.45-0.33 (m, 2H); 0.08--0.05 (m, 2H); MS: 449 (M+H) + .
EXAMPLE 4
In a manner analogous to that described in the first paragraph of Example 1, from 0.6 g of 1- 2(R)- 1(R or S)-(benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutylpropionyl!piperidine (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.5 g of 1- 3-cyclobutyl-2(R)- 1 (R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2, 5-dioxo-1-imidazolidinyl)ethyl!-propionyl!piperidine (diastereoisomer 1) in the form of a white foam.
nmr (MeOD): 3.67 (dd, 1H, J=15, 10); 3.64-3.46 (m, 4H); 3.34 (dd, 1H, J=15,8); 3.12 (td, 1H, J=13,3); 2.92-2.84 (m, 1H); 2.82 (s, 3H); 2.22-2.09 (m, 1H); 2.07-1.93 (m, 2H); 1.90-1.42 (m, 12H); 1.33 (s, 3H); 1.32 (s, 3H); MS: 423 (M+H) + .
EXAMPLE 5
In a manner analogous to that described in the first paragraph of Example 1, from 0.4 g of 1- 2(R)- 1(R or S)-(benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutylpropionyl!-4-piperidinol (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.294 g of 1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-4-piperidinol in the form of a white foam.
nmr (MeOD): 4.15-4.05 (m, 1H); 4.04-3.90 (m, 1H); 3.90-3.80 (m, 1H); 3.72-3.57 (m, 1H); 3.45-3.30 (m,2H); 3.18-3.06 (m, 2H) 2.94-2.85 (m,1H); 2.84 (d, 3H, J=5); 2.21-1.36 (m, 13H); 1.33 (d, 3H, J=3); 1.31(d, 3H, J=6); MS: 439 (M+H) + .
EXAMPLE 6
In a manner analogous to that described in the first paragraph of Example 1, from 0.642 g of 3- 2(R)- 1(R or S)-(benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutyl!-3-azabicyclo 3.2.2!nonane (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.348 g of 3- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-3-azabicyclo 3.2.2!nonane (diastereoisomer 1) in the form of a white foam.
nmr (MeOD): 3.92 3.83 (m, 2H); 3.76 (dd, 1H, J=15, 13); 3.67-3.57 (m, 2H); 3.34 (dd, 1H, J=15,5); 3.28-3.21 (m, 1H); 2.96-2.87 (m, 1H); 2.83 (s, 3H); 2.23-2.13 (m,1H); 2.12-1.92 (m, 4H); 1.91-1.48 (m,14H); 1.35(s, 3H); 1.34 (s, 3H). MS: 463 (M+H) + .
EXAMPLE 7
In a manner analogous to that described in the first paragraph of Example 1, from 0.5 g of 1- 2(R)- 1(R or S)-(benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopentylpropionyl!-4-piperidinol (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.4 g of 1- 3-cyclopentyl-2 (R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-4-piperidinol (diastereoisomer 1) in the form of a white foam.
nmr (MeOD): 4.20-4.02 (m, 2H); 3.91-3.83 (m, 1H); 3.76-3.64 (m,1H);3.48-3.32 (m, 2H); 3.26-3.08 (m, 3H), 2.05-1.42 (m, 12H); 1.38-1.25 (m, 7H); 1.18-1.01 (m, 3H); MS: 453 (M+H) + .
EXAMPLE 8
In a manner analogous to that described in the first paragraph of Example 1, from 0.57 g of 3- 2(R)- 1(R or S)-benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopentyl!-3-azabicyclo 3.2.2!nonane (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.48 g of 3- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamyl)-2- 3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-3-azabicyclo 3.2.2!nonane (diastereoisomer 1) in the form of a white foam.
nmr (MeOD): 3.88-3.67 (m, 5H); 3.39-3.31 (m, 2H); 2.92-2.85 (m, 4H); 2.15-2.06 (m, 2H); 1.83-1.45 (m, 16H); 1.36-1.28 (m, 7H; 1.16-1.02 (m, 2H). MS:477 (M+H) + .
EXAMPLE 9
A solution of 0.421 g of an approximately 6:1 mixture of diastereoisomer 1 and diastereoisomer 2 of 1- 2(R)- 1(R or S)-carboxy-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopentylpropionyl!piperidine, prepared in a manner analogous to that described in Example 1(i)-(viii), in 10 ml of dichloromethane was cooled to 0°. The solution was treated with 0.211 g of 1-hydroxybenzotriazole, 0.24 g of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride and 0.22 ml of N-methylmorpholine. The mixture was stirred at 0° for 15 minutes. A solution of 0.295 g of O-(tert-butyldimethylsilyl)hydroxylamine and 0.22 ml of N-methylmorpholine in 5 ml of dichloromethane was added. The mixture was left to warm to room temperature and was stirred overnight. The solution was washed with two portions of 5% aqueous sodium hydrogen carbonate solution and subsequently with 2M hydrochloric acid and saturated sodium chloride solution. After drying over anhydrous magnesium sulphate, the solvent was evaporated. The residue was purified by flash chromatography on silica gel using dichloromethane/methanol (96.4) for the elution to give 0.123 g of 1- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!piperidine (diastereoisomer 1) in the form of a white foam.
nmr (MeOD): 3.74-3.66 (m, 3H); 3.53-3.45 (m, 2H) 3.34 (dd, J=14,7,1H) 3.23 (dt, J=4, 14, 1H); 2.90-2.84 (m, 4H); 1.80-1.44 (m, 14H); 1.38-1.23 (m, 7H); 1.15-1.01 (m, 2H); MS: 437 (M+H) + .
EXAMPLE 10
In a manner analogous to that described in the first paragraph of Example 1, starting from 0.328 g of 1- 2(R)- 1(R or S)-(benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclohexylpropionyl!piperidine (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.269 g of 1- 3-cyclohexyl-2(R)- 1(R or S)-(hydroxycaxbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!piperidine (diastereoisomer 1) in the form of a white foam.
nmr (MeOD): 3.87-3.77 (m, 2H); 3.7 (dd, J=14,9,1H); 3.64-3.56 (m, 2H) 3.38-3.28 (m, 2H); 2.9-2.83 (m, 4H); 1.84-1.44 (m, 12H); 1.35(s, 3H); 1.33 (s, 3H); 1.25-1.05 (m, 5H); 0.98-0.78 (m, 2H). MS: 451 (M+H) + .
EXAMPLE 11
In a manner analogous to that described in Example 9, starting from 0.8 g of 1- 2(R)- 1(R or S)-carboxy-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopentylpropionyl!-tetrahydro-1,4-thiazine (diastereoisomer 1); prepared in a manner analogous to Example 1 (i)-(viii), there was obtained 0.3 g of 4- 3-cyclopentyl-2(R)- 1-(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-tetrahydro-1,4-thiazine (diastereoisomer 1) in the form of a white foam.
nmr (MeOD): 4.02-3.96 (m, 2H); 3.92-3.85 (m, 2H) 3.7 (dd, J=13,9,1H); 3.37 (dd. J=13,6,1H); 3.25-3.18 (m, 1H); 2.9-2.84 (m, 4H); 2.82-2.75 (m,1H); 2.7-2.55 (m, 3H); 1.78-1.45 (m, 8H); 1.35 (s, 3H); 1.34 (s, 3H) 1.18-1.04 (m, 2H). MS: 455 (M+H) + .
EXAMPLE 12
In a manner analogous to that described in Example 1, starting from 0.3 g of 4- 2(R)- 1(R or S)-(benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopentylpropionyl!-tetrahydro-1,4-thiazine S,S-dioxide (diastereoisomer 1), prepared in a manner analogous to that deseribed in Example 1 (i)-(ix), there was obtained 0.2 g of 4- 3-cyclopentyl-2(R)- 1-(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-tetrahydro-1,4-thiazine S,S dioxide (diastereoisomer 1) in the form of a white solid.
nmr (MeOD): 4.45-4.3 (m, 2H); 4.0-3.93 (m, 1H); 3.78-3.65 (m, 2H); 3.55-3.39 (m, 2H); 3.30-3.21 (m, 2H); 3.14-3.03 (m, 2H); 2.9-2.85 (m, 4H) 1.78-1.45 (m, 9H); 1.36 (s, 3H); 1.34 (s, 3H); 1.18-1.0 (m, 2H). MS: 487 (M+H) + .
EXAMPLE 13
In a manner analogous to that described in Example 9, starting from 0.8 g of 1- 2(R)- 1(R or S)-carboxy-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutylpropionyl!-tetrahydro-1,4-thiazine (diastereoisomer 1), prepared in a manner analogous to Example 1 (i)-(viii), there was obtained 0.24 g of 4- 3-cyclobutyl-2(R)- 1-(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-tetrahydro-1,4-thiazine (diastereoismer 1) in the form of a white solid.
nmr (MeOD): 3.98-3.75 (m, 4H); 3.64 (dd, J=13,8,1H); 3.35 (dd, J=15,6,1H); 3.07 (td, J=10,4,1H); 2.9-2.83 (m, 1H); 2.82 (s, 3H); 2.78-2.72 (m, 1H); 2.66-2.52 (m, 3H); 2.18-2.08 (m, 1H); 2.05-1.93 (m, 2H); 1.85-1.45 (m, 6H); 1.13 (s, 3H); 1.11 (s, 3H). MS: 441 (M+H) + .
EXAMPLE 14
In a manner analogous to that described in Example 9, starting from 1.22 g of 1- 2(R)- 1-(R or S)-carxboxy-2-(3,4,4-trimethyl-2,5-dioxo1-imidazolidinyl)ethyl!-3-cyclohexylpropionyl!-tetrahydro-1,4-thiazine(diastereoisomer 1), prepared in a manner analogous to Example 1 (i)-(viii), there was obtained 0.45 g of 4- 3-cyclohexyl-2(R)- 1(R or S)-(hydroxyicarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-tetrahydro-1,4-thiazine(diastereoisomer 1) in the form of a white solid.
nmr (MeOD): 4.12-4.03 (m, 2H); 3.95-3.88 (m, 1H); 3.75-3.65 (m, 2H); 3.38 (dd, J=14,6,1H); 2.88-2.82 (m, 4H); 2.78-2.72 (m, 1H); 2.68-2.55 (m, 3H); 1.82-1.53 (m, 7H); 1.35 (s, 3H); 1.34 (s, 3H); 1.26-0.8 (m, 8H); MS: 469 (M+H) + .
EXAMPLE 15
In a manner analogous to that described in Example 9, from 1.164 g of a mixture of diastereoisomers of 3- 2(R)- 1(RS)-carboxy-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopentylpropionyl!-5,5-dimethyl-N-propyl-4(R) -thiazolidinecarboxamide, prepared in a manner analogous to that described in Example 1 (i)-(viii), there was obtained 0.329 g of 3- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-5,5-dimethyl-N-propyl-4(R)-thiazolidinecarboxamide (diastereoisomer 1) in the form of a white solid.
nmr (MeOD): 5.09-4.72 (m, 2H); 4.51and 4.46 (both s, total 1H); 3.84 and 3.64 (both dd, J=14,8,1H); 3.40-3.05 (m, 4H); 2.90-2.73 (m, 4H); 1.94-1.25 (m, 23H); 1.23-1.01 (m. 2H); 0.99-0.85 (m; 3H); MS: 554 (M+H) + .
EXAMPLE 16
In a manner analogous to that described in the first paragraph of Example 1, from 0.223 g of 4- 2(R)- R or S)-(benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopentylpropionyl!morpholine (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.112 g of 4- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!morpholine (diastereoisomer 1) in the form of a white solid.
nmr (MeOD): 3.83-3.56 (m, 9H); 3.41(dd, J=14,6, 1H); 3.19 (dt, J=4,11,1H); 2.91-2.81 (m, 4H); 1.77-1.42 (m, 8H); 1.38-1.23 (m, 7H); 1.19-0.99 (m, 2H); MS: 439 (M+H) + .
EXAMPLE 17
In a manner analogous to that described in Example 9, from 1.289 g of a mixture of diastereoisomers of 3- 2(R)- 1(RS)-carboxy-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopentylpropionyl!-N,5,5-trimethyl-4(R)-thiazolidinecarboxamide (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(viii), there was obtained 0.629 g of 3- 3-cyclopentyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-N5,5-trimethyl-4(R)-thiazolidinecarboxamide (diastereoisomer 1) in the form of a white solid.
nmr (MeOD): 4.09-4.51 (m, 2H); 4.47 and 4.43 (both s, total 1H); 3.82 and 3.62 (both dd, J=14,10, total 1H); 3.37 and 3.17 (both dd; J=14,5, total 1H) 3.13-2.70 (m, 8H) 1.96-1.25 (m, 21H); 1.23-0.99 (m, 2H); MS: 526 (M+H) + .
EXAMPLE 18
In a manner analogous to that described in the first paragraph of Example 1, from 0.289 g of 1-2(R)- 1(R or S)-(benzyloxycarlbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutylpropionyl!-4-phenylpiperazine (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.121 g of 1- 3-cyclobutyl-2(R)- 1(R or S)- (hydroxycarbamoyl)methyl!-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-4-phenylpiperazine (diastereoisomer 1) in the form of a white solid.
nmr (MeOD): 7.25 (m, 2H; 7.00 (m, 2H); 6.85 (m, 1H); 3.94-3.73 (m, 4H); 3.66 (dd, J=14,7,1H); 3.43 (dd, J=14,6, 1H); 3.23-3.09 (m, 4H); 2.96-2.84 (m, 1H; 2.84 (s, 3H); 2.27-2.13 (m, 1H); 2.09-1.95 (m, 2H); 1.90-1.48 (m, 6H); 1.35 (s, 3H); 1.34 (s, 3H); MS:499 (M) + .
EXAMPLE 19
In a manner analogous to that described in the first paragraph of Example 1, from 0.455 g of 4- 2(R)- 1(R or S)-benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutylpropionyl!morpholine (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.194 g of 4- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!morpholine (diastereoisomer 1) in the form of a white solid.
nmr (MeOD): 3.80-3.51 (m,9H); 3.42(dd, J=14,6,1H); 3.14-3.06 (dt, J=4,11,1H); 3.04-2.86 (m, 1H); 2.85 (s, 3H); 2.23-2.11 (m, 1H); 2.06-1.95 (M, 2H); 1.91-1.73 (m, 2H), 1.71-1.46 (m, 4H); 1.35 (s, 3H); 1.34 (s, 3H); MS:425 (M) + .
EXAMPLE 20
In a manner analogous to that described in the first paragraph of Example 1, from 0.625 g of 1- 2(R)- 1(R or S)-benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3 -cyclobutylpropionyl!pyrrolidine (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.384 g of 1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!morpholine (diastereoisomer 1) in the form of a white solid.
nmr (MeOD): 3.77-3.69 (m, 1H); 3.61(dd, J=14,6,1H); 3.53-3.44 (m, 2H); 3.39-3.31 (m, 2H); 2.93-2.85 (m, 2H); 2.84 (s, 3H); 2.26-2.13 (m, 1H); 2.07-1.71 (m, 8H), 1.69-1.46 (m, 4H); 1.36 (s, 3H); 133 (s, 3H); MS:409 (M+H) + .
EXAMPLE 21
In a manner analogous to that described in the first paragraph of Example 1, from 0.176 g of 8- 2(R)- 1(R or S)-benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutylpropionyl!-1,4-dioxa-8-azaspiro 4,5!decane (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.084 g of 8- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-1,4-dioxa-8-azaspiro 4,5!decane (diastereoisomer 1) in the form of a white solid.
nmr (MeOD): 4.02 (s, 4H); 3.81-3.60 (m, 5H); 3.99 (dd, J=14,6,1H); 3.20-3.10 (m, 1H); 2.93-2.85 (m,1H); 2.84 (s,3H); 2.21-2.09 (m, 1H); 2.06-1.93 (m, 2H), 1.80-1.46 (m, 10H); 1.35 (s, 3H); 133 (s, 3H); MS:481 (M+H) + .
EXAMPLE 22
In a manner analogous to that described in the first paragraph of Example 1, from 0.443 g of 1- 2(R)- 1(R or S)-benzyloxycarbamoyl)-2-cyclobutylpropionyl!-4-methoxypiperidine (diastereoisomer 1) there was obtained 0.319 g of 1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!-4-methoxypiperdine (diastereoismer 1) in the form of a white solid.
nmr (MeOD): 3.96-3.80 (m, 2H); 3.69-3.59 (m, 1H); 3.54-3.23 (m, 7H); 3.18-3.09 (m, 1H); 2.93-2.80 (m, 4H); 2.21-2.09 (m, 1H); 2.07-1.41 (m, 12H), 1.41-1.38 (m, 6H); MS:453 (M+H) + .
The starting material was prepared as follows
(i) A solution of 0.925 g of 1- 2(R)- 1(R or S)-(tert.butoxycarbonyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclopropylpropionyl!-4-hydroxypiperidine in 8 ml of dimethylformamide was treated with 1.08 g of methyl iodide and 1.79 g of silver oxide. The mixture was stirred at room temperature in the dark for 2 days. Additional portions of 0.54 g of methyl iodide and 0.895 g of silver oxide were then added and the mixture was stirred for a further 3 days. The solvent was evaporated and the residue was suspended in ethyl acetate and filtered. The ethyl acetate solution was concentrated and the residue was purified by flash chromatography on silica gel using ethyl acetate for the elution. There was obtained 0.61 g of 1- 2(R)- 1(R or S)-(tert.butoxycarbonyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutylpropionyl!-4-methoxypiperidine in the form of a colorless gum.
(ii) In a manner analogous to that described in Example 1 (viii)-(ix) from 0.61 g of 1- 2(R)- 1(R or S)-(tert.butoxycarbonyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutylpropionyl!-4-methoxypiperidine there was obtained 0.443 g of 1- 2(R)- 1(R or S)-(benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutylpropionyl!-4-methoxypiperidine (diastereoisomer 1) in the form of a colorless gum.
EXAMPLE 23
In a manner analogous to that described in the first paragraph of Example 1, from 0.94 g of 1- 2(R)- 1(RS)-benzyloxycarbonoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutlylpropionyl!-octahydroazocine (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.663 g of 1- 3-cyclobutyl-2(R-)- 1(R or S)-(hydroxycarbamoyl)-2-(3 4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!octahydroazocine (diastereoisomer 1) in the form of a white solid:
nmr (MeOD): 3.77 (dd, J=14,10,1H); 3.66-3.43 (m, 4H); 3.33 (dd, J=14,5,1H); 3.07(dt, J=10,4,1H); 2.91-2.81 (m,4H); 2.29-2.16 (m, 1H); 2.10-1.95 (m, 2H), 1.90-1.46 (m, 16H); 1.34 (s, 6H); MS:451 (M+H) + .
EXAMPLE 24
In a manner analogous to that described in the first paragraph of Example 1, from 0.37 g of 1- 2(R)- 1(R or S)-benzyloxycarbamoyl)-2-(5,5-dimethyl-2,4-dioxo-3-oxazolidinyl)ethyl!-3-cyclobutylpropionyl!piperidine (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (v)-(ix) using 3-(bromomethyl)-5,5-dimethyloxazolidine-2,4-dione in place of 1-(bromomethyl)-3,4,4-trimethyl-2,5-imidazolinedione, there was obtained 0.131 g of 1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl)-2-(5,5-dimethyl-2,4-dioxo-3-oxazolidinyl)ethyl!propionyl!-piperidine (diastereoisomer 1) in the form of a white solid:
nmr (MeOD): 3.72-3.53 (m, 5H); 3.39 (dd, J=14,6,1H); 3.14 (dt, J=10,4,1H); 2.95-2.86 (m, 1H); 2.23-2.11 (m, 1H); 2.08-1.94 (m, 2H); 1.90-1.44 (m, 18H); MS:410 (M+H) + .
EXAMPLE 25
In a manner analogous to that described in the first paragraph of Example 1, from 0.42 g of 1- 2(R)- 1(R or S)-benzyloxycarbamoyl)-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!-3-cyclobutylpropionyl!hexahydroazepine (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), there was obtained 0.197 g of 1- 3-cyclobutyl-2(R)- 1(R or S)-(hydroxycarbamoyl-2-(3,4,4-trimethyl-2,5-dioxo-1-imidazolidinyl)ethyl!propionyl!hexahydroazepine (diastereoisomer 1) in the form of a white solid:
nmr (MeOD): 3.77-3.64 (m, 2H); 3.62-3.45 (m, 3H); 3.33 (dd, J=4,5,1H); 3.07 (dt, J=10,4,1H); 2.91-2.81 (m, 4H); 2.24-2.13 (m, 1H); 2.09-1.95 (m, 2H); 1.90-1.47 (m, 14H); 1.35 (s, 3H); 134 (s, 3H); MS:437(M+H) + .
EXAMPLE 26
In a manner analogous to that described in the first paragraph of Example 1, from 0.37 g of 1- 2(R)- 1(R or S)-benzyloxycarbamoyl)-2-(hexahydro-1,3-dioxopyrazolo 1,2-a! 1,2,4!triazol-2-yl)ethyl!-3-cyclobutylpropionyl!piperidine (diastereoisomer 1), prepared in a manner analogous to that described in Example 1 (i)-(ix), using 2-(bromomethyl)-hexahydro-1,3-dioxopyrazolo 1,2-a! 1,2,4!triazole, there was obtained 0.118 g of 1- 3-cyclobutyl-2(R)- 2-(hexahydro-1,3-dioxopyrazolo 1,2-a! 1,2,4!triazol-2-yl)-1(R or S)-(hydroxycarbamoyl)ethyl!propionyl!piperidine in the form of a white solid.
nmr (MeOD): 3.68-3.56 (m,8H); 3.52-3.39 (m,2H); 3.17-3.09 (m,1H); 2.97-2.90 (m, 1H); 2.35-2.27 (m,2H); 2.21-2.11 (m,1H); 2.07-1.95 (M,2H); 1.88-1.44 (m,12H) MS:422 (M+H) + .
EXAMPLE 27
In a manner analogous to that described in the first paragraph of Example 1, from 0.222 g of 1- 2(R or S)-(benzyloxycarbamoyl)-2-phthalimidoethyl!-3-cyclobutylpropionyl!piperidine prepared in a manner analogous to that described in Example 1(i)-(ix) using N-(bromomethyl)-phthalimide, there was obtained 0.013 g of 1 3-cyclobutyl-(2(R)- 1(R or S)-(hydroxycarbamoyl)-2-phthalimidoethyl!propionyl!piperidine (diastereoisomer 1) in the form of a white solid.
nmr (MeOD): 7.87-7.75 (m.4H); 3.83 (dd,J=14.8,1H); 3.66-3.58 (m,3H); 3.53-3.45 (m,1H); 3.35-3.25 (m,1H); 3.20-3.12 (m,1H); 3.04-2.97 (m,1H); 2.23-2.11 (m,1H); 2.08-1.95 (m,2H); 1.89-1.41 (m,12H); MS:428 (M+H) + .
The following Examples illustrate pharmaceutical preparations containing the hydroxamic acid derivatives provided by the present invention:
EXAMPLE A
Tablets containing the following ingredients may be produced in a conventional manner:
______________________________________Ingredient Per tablet______________________________________Hydroxamic acid derivative 10.0 mgLactose 125.0 mgCorn starch 75.0 mgTalc 4.0 mgMagnesium stearate 1.0 mgTotal weight 215.0 mg______________________________________
______________________________________Ingredient Per capsule______________________________________Hydroxamic acid derivative 10.0 mgLactose 165.0 mgCorn starch 20.0 mgTalc 5.0 mgCapsule fill weight 200.0 mg______________________________________ | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to a silane cross-linked, chlorine-resistant polyolefin tube made by the so-called single-stage silane process.
Plastic tubular conduits are made from a large number of polymer materials.
In the field of materials for thermoplastic tubes particularly polyvinyl chloride, polypropylene, polyethylene, polybutylene or cross-linked polyolefin are utilized.
The cross-linking of polyolefins may be effected chemically or physically. As described, for example, in Kautschuk, Gummi, Kunststoff, 34th year, No. 3/1981, pages 197 ff, in the technically significant cross-linking technologies a distinction is made between radiation cross-linking, peroxide cross-linking and silane cross-linking.
The last-named process distinguishes itself from the other cross-linking methods primarily by the process technique: In a first process step the polymer chain radicals are generated with the aid of the usual radical initiators, to which, in a second process step, the silane molecules with their vinyl function are added. Such silane-grafted polymers may still be thermoplastically processed. The cross-linking proper takes places after shaping by a silane condensation reaction in the presence of heat and moisture. Such a so-called two-stage silane process is described in U.S. Pat. No. 3,646,155.
In contrast, British Patent No. 1,526,398 describes the so-called single-stage silane process. In this process all additives are simultaneously dosed with the polymer in a specially designed extruder for producing online the desired extruded material. Subsequently, cross-linking is effected in the presence of heat and moisture.
An application of a single-stage silane process, particularly for drinking-water tubes in the USA, is described in U.S. Pat. No. 6,284,178. In this process a residual methanol content of less than 12.2 ppm in the tube is obtained by using a maximum of 1.8 weight percent mixture of silane/peroxide/catalyst and by setting the duration of cross-linking at more than 4 hours. No mention is made concerning a chlorine-resistant provision of such a silane cross-linked polyethylene tube with special stabilizers. Rather, the combination of Irganox B215 and Irganox 1010 described in U.S. Pat. No. 6,284,178 has—because of the low melting point of the phenolic constituents—a much too low extraction resistance against chlorine water.
This prevents in practice the use of silane tubes made in accordance with U.S. Pat. No. 6,284,178.
The reason is that drinking water in the USA is provided, for purposes of disinfection, with a larger chlorine dose as compared to European conditions. As known by the specialist, at an appropriate pH-value, chlorine water may produce hypochlorous acid HOCl which is strongly oxidizing and therefore may lead to a premature failure of the tube.
It is the object of the invention to provide a silane cross-linked polyolefin tube which is made in a one-stage process and which is chlorine-resistant at a chlorine content between 0.1 and 5 ppm, which has minimum degree of cross-linking of 60%, and which further satisfies the standard specifications for cross-linked polyethylene tubes, set by the various ASTM and NSF norms.
SUMMARY OF THE INVENTION
The above object has been successfully achieved according to the invention by a tube having a polyolefin composition, comprising:
(A) a polyolefin,
(B) a mixture of an organic silane of the general formula RSiX 3 with a radical-generating constituent and a catalyst, and with
(C) a stabilizer mixture of a high-molecular phenolic constituent with a sulfur-containing constituent, a phosphorus-containing processing stabilizer and a metal deactivator.
It has been a main difficulty in solving the object of the invention that the added stabilizers and the radical-generating constituents mutually affect one another in the reactive extrusion process, and thus, after processing, negatively alter the terminal cross-linking degree and the residual stabilization in the tube. The level of residual stabilization, however, is decisive for a good chlorine resistance and is achieved only by a deliberate choice of the type and quantity of the individual constituents.
Furthermore, the possible extraction of the stabilizer package in chlorine water is critical. A suitable resistance to extraction may be achieved only if the phenolic constituent combines a large molecular weight with a high melting point and the sulfur-containing constituent, the phosphorus-containing processing stabilizer and the metal deactivator have large non-polar partial chains.
The degree of chrystallinity of the cross-linked tube is, not in the least, also an important magnitude; it is essential for the durability of its service life. This is so, because, as a rule, the degree of chrystallinity of the utilized polyethylene (PE) is reduced, for example, from 70% to, for example, 65% by the graft reaction and cross-linking, so that measures have to be taken to raise the degree of chrystallinity to the value appropriate for its application in question. This is achieved according to the invention by a tempering step at temperatures between 70-95° C. The duration required therefor depends from the PE utilized, how the reaction is run, and the specification to be obtained.
DETAILED DESCRIPTION
In the description that follows, the invention will be set forth in more detail.
The constituent (A) of the silane cross-linked polyolefin tube according to the invention is contained at 100 weight parts in the recipe and is either a low-pressure polyethylene (HDPE) made according to the Ziegler process or the Phillips process and having a degree of chrystallinity between 60 and 80% and a density of from 0.942 to 0.965 g/cm 3 or a polyethylene of medium density (MDPE; 0.930 to 0.942 g/cm 3 ).
The constituent (B) is a mixture of an organic silane of the general formula RSiX 3 (B1), a radical-generating constituent (B2) and a catalyst (B3). The organic silane RSiX 3 (B1) may be a vinyltrimethoxysilane, vinyltriethoxysilane or 3-(methacryloxy)propyltrimethoxysilane. The radical-generating constituent (B2) may be an alkylperoxide, acylperoxide, ketoneperoxide, hydroperoxide, peroxocarbonate, perester, peroxoketal, peroxooligomer or an azo compound. Particularly preferred are organic alkylperoxides having half-value times of 0.1 hour at temperatures>80° C., such as 2,5-dimethyl-2,5-di(tertiary-butylperoxy)hexane and/or 2,5-dimethyl-2,5-di(tertiary-butylperoxy)3-hexine and/or di(tertiarybutyl)peroxide and/or 1,3-di(tertiary-butyl-peroxyiso-propyl)benzol and/or dicumylperoxide and/or tertiary-butylcumylperoxide. The catalyst (B3) may be dibutyltindilaurate, dibutyltinoxide, tinoctoate, dibutyltinmaleate or titanylacetonate. The weight part of the constituent (B), related to constituent (A), may be between 0.1 and 5 parts; particularly preferred are weight parts between 1 and 3.
Constituent (C) is a stabilizer mixture of a high-molecular phenolic constituent (C1) having a high melting point, a sulfur-containing constituent (C2), a phosphorus-containing processing stabilizer (C3) and a metal deactivator (C4).
The high-molecular phenolic stabilizer (C1) having a high melting point is selected from the group of 2,2′-methylene-bis(6-tertiary-butyl-4-methylphenol), 1,3,5-trimethyl-2,4,6-tris(3,5-di-tertiary-butyl-4-hydroxybenzyl)benzol, octadecyl 3-(3,5-di-tertiary-butyl-4-hydroxyphenyl)propionate, 1,1,3-tris(2-methyl-4-hydroxy-5-tertiary-butylphenyl)butane, tris(3,5-di-tertiary-butyl-4-hydroxybenzyl)isocyanurate, tris(4-tertiary-butyl-3-hdroxy-2,6-dimethylbenzyl)isocyanurate, pentaerythritol tetrakis(3,5-di-tertiary-butyl-4-hydroxyhydrocinnamate) or 1,3,5-tris(3,5-di-tertiary-butyl-4-hydroxybenzyl)triazine.
The sulfur-containing constituent (C2) may be a 5-tertiary-butyl-4-hydroxy-2-methylphenyl sulfide, 3-tertiary-butyl-2-hydroxy-5-methylphenyl sulfide, dioctadecyl-3,3′-thiodipropionate, dilauryl 3,3′-thiodipropionate or ditetradecyl-3,3′-thiodipropionate.
The phosphorus-containing processing stabilizer (C3) may be a tris(nonylphenyl)phosphite, tris(2,4-di-tertiary-butylphenyl)phosphite, tetrakis(2,4-di-tertiary-butylphenyl)-4,4′-biphenyldiphosphonite, 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecan or 3,9-bis(2,4-dicumylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecan.
The metal deactivator (C4) is selected from the group of 1,2-bis(3,5-di-tertiary-butyl-4-hydroxyhydrocinnamoyl)hydrazide or 2,2′-oxalyldiamidobis-(ethyl-3-(3,5-di-tertiary-butyl-4-hydroxyphenyl)propinate) or oxalic bis(benzylidenehydrazide).
Very particularly preferred constituents (C) are 1,3,5-trimethyl-2,4,6-tris(3,5-di-tertiary-butyl-4-hydroxybenzyl)benzol (C1), dioctadecyl-3,3′-thiodipropionate (C2), tris(2,4-di-tertiary-butylphenyl)phosphite (C3) and 1,2-bis(3,5-di-tertiary-butyl-4-hydroxyhydrocinnamoyl)hydrazide (C4).
The weight part of the constituent (C) related to the constituent (A) may be between 0.1 and 5 parts.
To the chlorine-resistant tubes according to the invention there may be added up to 20 weight parts additives, related to constituent (A), in the form of up to 5 weight parts lubricant or processing agents, up to 5 weight parts nucleation agents, up to 5 weight parts antistatic agents, up to 10 weight parts process oils, up to 10 weight parts pigments, up to 5 weight parts expanding agents or up to 5 weight parts ultraviolet stabilizers.
By virtue of these particularities, the making of silane cross-linked, chlorine-resistant tubes according to the single-stage process is not obvious. Only the deliberate selection of the type and quantity of special stabilizers and the recipe adapted thereto as well as the process technique permit not only the manufacture of tubes having the usual property image, but also lead in a surprising manner to an advantageous property image, as set forth in the formulation of the object of the invention, particularly as concerns the resistance against a chlorine content between 0.1 and 5 ppm.
The chlorine-resistant, silane cross-linked polyolefin tubes are made according to the single-stage silane process, that is, the graft reaction of the silane of the constituent (B1) on the polyolefin of the constituent (A) and the shaping proceed simultaneously in one process step. Additionally to the monosil process described in the state of the art, a barrier screw is utilized for an effective distribution of the liquid constituents prior to the grafting step and for avoiding a preliminary cross-linking. A fusion pump may additionally also be utilized.
After processing, the tubes are cross-linked in a cross-linking chamber in a water vapor atmosphere at temperatures between 80 and 100° C. until a cross-linking degree of more than 60% is obtained. Thereafter occasionally a tempering step at 70-95° C. follows, until the desired, application-dependent degree of chrystallinity is obtained.
Tests on service life durability after a tempering step show, because of the increased degree of chrystallinity, an increased service life of the chlorine-resistant tubes according to the invention.
The application of the cross-linked tubes according to the invention is preferably in the field of tubes for drinking water and/or water for industrial use with and without a diffusion blocking layer.
The invention will be further explained by way of exemplary embodiments whose description follows.
The compositions are given in weight parts related to 100 weight parts of constituent (A) and are present in the Examples as follows:
Examples
Example 1
Example 2
Example 3
Example 4
polyethylene
100 [1]
100 [2]
100 [2]
100 [1]
constituent (A)
constituent (B)
2.30 [3]
2.05 [3]
2.10 [3]
2.30 [3]
constituent (C)
0.41 (C1) [4]
0.49 (C1) [4]
0.53 (C1) [4]
0.41 (C1) [4]
0.10 (C2) [6]
0.15 (C2) [6]
0.16 (C2) [6]
0.10 (C1) [5]
0.16 (C3) [8]
0.19 (C3) [8]
0.21 (C3) [8]
0.10 (C2) [6]
0.10 (C4) [9]
0.12 (C4) [9]
0.13 (C4) [9]
0.16 (C3) [8]
0.10 (C4) [9]
comparison
Example 5
Example 6
example
polyethylene
100 [1]
100 [1]
100 [2]
constituent (A)
constituent (B)
2.30 [3]
2.30 [3]
1.95 [3]
constituent (C)
0.41 (C1) [4]
0.41 (C1) [4]
[10]
0.10 (C2) [7[
0.10 (C2) [6]
0.16 (C3) [8]
0.10 (C4) [9]
0.10 (C4) [9]
Explanations [1] to [10] for constituents (A), (B), (C1) to (C4) for the Examples:
[1] polyethylene having a density [g/cm 3 ] of 0.952 and MFI [g/10 min] of 5-7 (190° C./2.16 kg) [2] polyethylene having a density [g/cm 3 ] of 0.944 and MFI [g/10 min] of 4 (190° C./2.16 kg) [3] silane/peroxide/catalyst mixture: viscosity [mPasec]=2.5 (at 23° C.); density [g/cm 3 ]=0.969, colorless liquid [4] 1,3,5-trimethyl-2,4,6-tris(3,5-di-tertiary-butyl-4-hydroxybenzyl)benzol; molecular weight [g/mol]=775 [5] pentaerythritol tetrakis(3,5-di-tertiary-butyl-4-hydroxyhydrocinnamat); molecular weight [g/mol]=1178 [6] dioctadecyl-3,3′-thiodipropionate; molecular weight [g/mol]=683 [7] 3-tertiary-butyl-2-hydroxy-5-methylphenyl sulfide; molecular weight [g/mol]=358.5 [8] tris(2,4-di-tertiary-butylphenyl)phosphite; molecular weight [g/mol]=647 [9] 1,2-bis(3,5-di-tertiary-butyl-4-hydroxyhydrocinnamoyl)hydrazide; molecular weight [g/mol]=552 [10] stabilizer-MB: Vibatan PEX Antiox 02012, added quantity 5 parts.
EXAMPLES 1-6
In a single-screw extruder which is provided with a barrier screw and a metering device and which is intended for the liquid silane/peroxide/catalyst mixture, the polyolefin (A) and the stabilizer mixture (C) are dosed by means of a metering scale. The mixture is melted and the liquid silane/peroxide/catalyst mixture (B) is dosed in and shaped to form a tube.
The requirements concerning a chlorine-resistant drinking-water tube in the USA are listed in the NSF Protocol P171 (1999 edition). A combination of a “Differential Scanning Calometry” (DSC) experiment with a modified test for service life durability has been found suitable for a practical determination of the chlorine resistance.
With the DSC experiment, oxidation reactions of synthetic materials may be generally determined. The OIT (oxidizing induction time) represents a process with which information may be obtained concerning the stability of polyolefin tubes against oxidizing attacks. In the static process (ASTM norm D3895) utilized here, the specimen is heated to a temperature of 210° C. in an inert atmosphere. The temperature is maintained. After equilibrium sets in, the scavenging gas is switched from an inert atmosphere to an oxidizing atmosphere. The exothermal oxidizing reaction then starts after a certain delay. By means of the DSC experiments fine nuances in the critical residual stabilizer content may be detected in the chlorine-resistant, silane cross-linked polyolefin tubes of the invention.
Further, a modified test for service life durability has been performed as a pre-test. In this test the tube sections having a length greater than 30 cm are exposed under pressure to chlorinated tap water at a PH-value of 7 and submitted to a test of service life durability at temperatures of 20° C., 95° C. and 110° C. and subjected to different pressures p [Nmm-2]. Every 8 days the tube sections are taken out and examined concerning the chlorine concentration and PH-value.
The table below shows the properties of the tubes according to the invention.
Example 1
Example 2
Example 3
Example 4
mean cross-
71.2
72.6
74.6
70.6
linking degree in
[%] according to
ASTM F876-01
OIT 210° C. [min]
73.3
105.7
119.3
91.0
service life at
>1660
>1660
>1660
>1660
95° C. in hours
p = 4.65-4.71*)
with chlorine
water
service life at
>380
>380
>380
>380
110° C. in hours
p = 2.75-2.81*)
with chlorine
water
service life at
>290
17.5
12.95
>290
20° C. in hours
p = 12.0-12.5*)
with chlorine
water
comparative
Example 5
Example 6
example
mean cross-
66.7
68.8
65.5
linking degree in
[%] according to
ASTM F876-01
OIT 210° C. [min]
80.0
74.4
41.9
service life at
>1660
>1660
0.52
95° C. in hours
p = 4.65-4.77*)
with chlorine
water
service life at
>380
>380
>380
110° C. in hours
p = 2.75-2.84*)
with chlorine
water
service life at
>290
290.3
5.33
20° C. in hours
p = 12.0-12.5*)
with chlorine
water
*p means the pressure range in Nmm −2 | 4y
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FIELD OF THE INVENTION
This invention relates to an automatic player piano and, more particularly, to an estimation of a strength of touch used for formation of a musical information in a recording mode of operation.
BACKGROUND OF THE INVENTION
In general, an automatic player piano is shifted between a recording mode of operation and a playback mode of operation. In the recording mode of operation, the keys are successively depressed by the fingers of a human player for specifying notes, and the pedals may be occasionally operated by the feet for prolonging the sounds, lessening the volumes or sustaining the notes. Since a lot of sensors are provided in association with the keys and the pedals, those key movements and pedal operations are detected to form pieces of the musical information which are memorized in a suitable storage. After formation of the pieces of the musical information, the automatic player piano is capable of shifting into the playback mode of operation. In the playback mode of operation, the pieces of the musical information are retrieved in succession from the storage for driving the keys and the pedals, if necessary, thereby allowing the automatic player piano to perform the music without the human player.
In an actual performance, each tone is loud or soft according to the strength of the key touch for an expressiveness, and, for this reason, the automatic player piano is provided with touch sensors for detecting the hammer velocities used for an estimation of the key touch. FIG. 1 shows a typical example of the automatic player piano provided with the touch sensors. In FIG. 1, reference numeral 1 designates a mechanical piano of the upright type which largely comprises a keyboard provided with a plurality of typically 88 keys, a key action mechanism provided in association with the keys for transmission of the key motions, a plurality of hammer assemblies respectively driven for rotations by the key action mechanism, a plurality of music wires struck with the hammer assemblies, respectively, and a plurality of damper assemblies respectively engageable with the music wires. Thus, the keys to the damper assemblies are incorporated in multiple, however, only one line of members, i.e., the key, the key action mechanism, the hammer assembly, the music wire and the damper assembly are illustrated in FIG. 1 and designated by reference numerals 2, 3, 4, 5 and 6, respectively. Though not shown in the drawings the mechanical piano 1 is further provided with a set of pedals. However, the mechanical piano of this type is well known in the art, so that no further description is incorporated.
The automatic player piano shown in FIG. 1 is accompanied with a controller 7 coupled at the input ports thereof to plural pairs of photo couplers and at the output ports thereof to a plurality of solenoid-operated actuators, and each pair of the photo couplers are spaced apart from each other along a traveling path of each hammer assembly, and optical paths of the photo couplers extend across the travel path, respectively. For the hammer assembly 4, the photo couplers 8 and 9 are located along the travel path thereof as will be seen from FIG. 1. By virtue of the multiple arrangement of the photo couplers 8 and 9, the motion of the hammer assembly 4 is detectable with the photo couplers, and the strength of the key touch is estimated on the basis of a time interval consumed between the interruptions of the optical paths of the photo couplers 8 and 9. In detail, if the human player depresses the key 2 with a large force, the large force is transmitted from the key 2 through the key action mechanism 3 to the hammer assembly 4, then allowing the hammer assembly 4 to rotate toward the music wire 5 at a large velocity. When the hammer assembly 4 is driven for rotation at the large velocity, the time interval is decreased in value, however, if the hammer rotates at a small velocity with a relatively small force, the time interval is prolonged. In general, the larger force the key 2 is subjected to, the shorter time interval the hammer assembly 4 consumes. Then, an inverse relationship is established between the force, or the key touch, and the velocity of the hammer assembly 4. In accordance with the inverse relationship, a piece of the key touch information is produced on the basis of the time interval calculated by the controller 7 and memorized therein.
The solenoid-operated actuators are provided in association with the keys and the pedals, respectively, and these solenoid-operated actuators are selectively energized by the controller 7 for actuations, thereby causing the keys and the pedals to be driven for selective movements, respectively. Then, if the piece of the key touch information is retrieved for the key 2 in the playback mode of operation, the solenoid-operated actuator 10 is energized with an electric power by the controller 7 to provide a power tantamount to that transmitted from the key 2 upon the original key depression. In this manner, the solenoid-operated actuators are selectively energized by the controller 7 to perform the music which was originally performed by the human player.
However, a problem is encountered in the prior-art automatic player piano in trammel of each photo coupler. As described hereinbefore, each hammer assembly is accompanied with a pair of photo couplers, so that the total number of the photo couplers is calculated as 88 multiplied by 2 or 176. These photo couplers should be precisely located at the respective positions, otherwise, the music produced in the playback mode of operation would be different from the original music. However, the precise trammel is not easy, because the hammers are different in size and in location depending upon the piano type, the model and the manufacturer and so on. In other words, the mechanical pianos have not been standardized yet. If each photo coupler is installed during the manufacturing process of the mechanical piano 1, the photo couplers may, make the manufacturing process to be a little bit complicated. However, the user occasionally requests the manufacturer to remodel the mechanical piano into an automatic player piano. This request provides a serious difficulty to the piano manufacturer, because the manufacturer hardly designs the photo couplers and the solenoid-operated actuators until the user's mechanical piano is checked by the manufacturer. After the user's mechanical piano is checked, the manufacturer can tailor the photo couplers and the actuators, so that a relatively long time period is consumed from the order for the remodeling to the completion of the work. This results in increasing of remodeling cost.
Moreover, the prior-art automatic player piano has another problem in stability of the production of the key touch information. This problem results from deformations of the component members which are usually made of wood, and a secular change in humidity due to heat attacks is causative of such a deformation. A large number of solenoid-operated actuators and the photo couplers are serious heat sources for the component members of wood. When the component members are deformed, the hammer velocity tends to be shifted, and, for this reason, the pieces of the key touch information do not indicate the original key touches during the service life of the automatic player piano.
SUMMARY OF THE INVENTION
It is therefore an important object of the present invention to provide an automatic player piano which is easy for remodeling.
It is also another important object of the present invention to provide an automatic player piano which is fit for use for a prolonged period of time with a credible stability.
To accomplish these objects, the present invention proposes to estimate the strength of a key touch on the basis of the key motion.
In accordance with one aspect of the present invention, there is provided an automatic player piano operable in a recording mode of operation and a playback mode of operation, comprising: (a) a mechanical piano having (a-1) a keyboard mounted on a key bed and provided with a plurality of keys respectively depressed with forces by a player, (a-2) a key action mechanism coupled to the keyboard for transmitting the forces exerted on the keys, (a-3) a hammer mechanism provided with a plurality of hammer assemblies, the hammer assemblies being coupled to the key action mechanism and driven for rotations with the forces transmitted by the key action mechanism, and (a-4) a plurality of music wires respectively struck with the hammer assemblies for producing sounds; and (b) an automatic player system having (b-1) a controller operative to memorize pieces of a key touch information respectively representative of grades of intensity assigned to the sounds in the recording mode of operation and retrieve the pieces of the key touch information in the playback mode of operation, (b-2) a plurality of actuators provided in association with the keyboard and responsive to the pieces of the key touch information for causing the keys to move, and (b-3) a sensor unit provided between the key bed and the keyboard and operative to detect key motions of the keys for producing the pieces of the key touch information in the recording mode of operation, in which each of the pieces of the key touch information is estimated on the basis of each of the key motions.
In accordance with another aspect of the present invention, there is provided a key touch estimation system provided in association with a mechanical piano having a keyboard provided with a plurality of keys respectively depressed with forces by a player, a key action mechanism coupled to the keyboard for transmitting the forces exerted on the keys, a hammer mechanism provided with a plurality of hammer assemblies, the hammer assemblies being coupled to the key action mechanism and driven for rotations with the forces transmitted by the key action mechanism, and a plurality of music wires respectively struck with the hammer assemblies for producing sounds, the key touch estimation system comprising (a) a controller operative to memorize pieces of key touch information respectively representative of grades of intensity assigned to the sounds in the recording mode of operation and retrieve the pieces of the key touch information in the playback mode of operation, (b) a plurality of actuators provided in association with the keyboard and responsive to the pieces of the key touch information for causing the keys to move, (c) a sensor unit provided in association with the keyboard and operative to detect key motions of the keys for producing the pieces of the key touch information in the recording mode of operation, (d) tracing means operative to produce loci of the key motions, (e) sampling means operative to extract sections for uniform motions from the loci, respectively, f) key velocity calculating means operative to decide key velocities in the sections, respectively, (g) final hammer velocity deciding means operative to estimate final velocities of the hammer assemblies on the basis of the key velocities, respectively, and (h) key touch information producing means operative to produce the pieces of the key touch information on the basis of the final velocities, respectively.
PRINCIPLE ON WHICH THE PRESENT INVENTION IS BASED
In the prior-art automatic player piano, the key touch is estimated on the basis of the hammer action or the time interval from the interruption detected by the photo coupler 8 and to interruption detected by the photo coupler 9. This is because of the fact that the grades of tone intensity are directly related to the hammer velocity. In other words, the key motion was considered not to be representative of the tone intensity, because the key is not fully depressed at all times. The human player sometimes repeats the partial depression from the nondepressed state to an intermediate state, which is sometimes referred to as "shallow touch", and, on the contrary, the key may be repeatedly depressed from the intermediate state to the fully depressed state. In this situation, the key touch can not be estimated from a time interval between fixed detecting points, because the maximum velocity is not always achieved between the fixed detecting points.
Efforts are made by the inventors for establishment of a relationship between the key touch and the key motion. Loci are plotted for various key operations as illustrated in FIGS. 2 to 5.
Plots A and B in FIG. 2 respectively represent the loci of the key produced upon the full key depressions in forte and in piano, and plots C and D are indicative of loci of the hammer corresponding to the key motions represented by the plots A and B, respectively. As will be understood from the plots A and B, the key is rapidly accelerated in a section a1 and, then, achieves a uniform motion in a section a2 after the forte keying-in operation, however, when the key is depressed in the piano touch, the key is gradually accelerated to achieve a uniform motion in a section b.
Plots E, F and G in FIG. 4 are indicative of the loci of the key produced upon a repetition, an extremely shallow touch and an usual shallow touch, respectively. Plots H, I and J are representative of loci of the hammer which are produced in the linkage of the key tracing the plots E to G, respectively. When the key is repeatedly depressed along the plots E, the key moves with the force of inertia in a section e1 and is, then, accelerated in a section e2, then achieving a uniform motion in a section e3. However, if the key is depressed in the extremely shallow manner, the key is rapidly accelerated in a section f1 and immediately achieves a uniform motion in a section f2. On the other hand, upon the usual shallow touch, the key is rapidly accelerated in a section g1 and, then, achieves a uniform motion in a section g2 followed by a section g3 for an inertia motion.
Thus, the key motions are different from one another depending upon the key touch, however, the inventors discover that key velocity in the uniform motion is related to the final hammer velocity as illustrated in FIG. 6. In FIG. 6, plots except for these encircled stand for the uniform motions in FIG. 2, respectively, and the encircled plots are indicative of the uniform motions in FIG. 4, respectively. As will be understood from FIG. 6, the plots are placed on a line K or in the vicinity of the line K, so that the final hammer velocity is related to the key velocity in the uniform motion regardless of the key touch. The final hammer velocity is directly proportional to the grade of intensity or loudness, and, for this reason, the key touch is capable of being estimated from the key velocity in the uniform motion.
BRIEF DESCRIPTION OF THE DRAWINGS
The features and advantages of an automatic player piano according to the present invention will be more clearly understood from the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is side view showing the structure of a typical automatic player piano;
FIG. 2 is a graph showing loci of a key produced in the full depressions;
FIG. 3 is a graphic showing loci of a hammer linked with the key tracing the loci indicated in FIG. 2;
FIG. 4 is a graph showing loci of the key produced in repeated key depressions and shallow touches;
FIG. 5 is a graph showing loci of the hammer linked with the key tracing the loci indicated in FIG. 4;
FIG. 6 is a graph showing the relationship between the key velocity in the uniform motion and the final hammer velocity;
FIG. 7 is a block diagram showing, in a modeled form, the arrangement of a automatic player piano embodying the present invention;
FIG. 8 is a side view showing the mechanical arrangement of the automatic player piano shown in FIG. 7;
FIG. 9 is a block diagram showing the circuit arrangement of the controller incorporated in the automatic player piano shown in FIG. 7;
FIG. 10 is a flowchart showing the sequence of a mainroutine program executed by the controller shown in FIG. 9;
FIGS. 11A and 11B are flowcharts showing the sequence of a recording subroutine program executed by a micro-computer unit incorporated in the controller;
FIG. 12 is a side view showing the arrangement of a part of another automatic player piano embodying the present invention;
FIG. 13 is a perspective view showing, in a disassembled state, the arrangement of a sensor unit incorporated in the automatic player piano partially shown in FIG. 12;
FIG. 14 is a plan view showing an encoder plate incorporated in the sensor unit shown in FIG. 13;
FIG. 15 is a plan view showing another encoder plate incorporated in still another automatic player piano embodying the present invention;
FIG. 16 is a block diagram showing the circuit arrangement of a signal processing circuit associated with the sensor unit with the encoder plate shown in FIG. 15;
FIG. 17 is a plan view showing still another encoder plate used in still another automatic player piano embodying the present invention;
FIG. 18 is a block diagram showing the circuit arrangement of a signal processing circuit incorporated in the automatic player piano with the encoder plate shown in FIG. 17; and
FIG. 19 is a diagram showing waveforms of essential signals produced in the signal processing circuit shown in FIG. 18.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
First embodiment
Speculative Description of Production of Key Touch Information
Referring to FIG. 7 of the drawings, there is shown a general arrangement of an automatic player piano embodying the present invention. FIG. 7 is provided for focusing upon production of key touch information, and, for this reason, the other components omitted therefrom. The automatic player piano largely comprises a mechanical piano 21 and an automatic player system 22, and the mechanical piano 21 has a keyboard with a plurality of typically 88 keys, a key action mechanism 23 coupled to the keys, a plurality of hammer assemblies linked with the key action mechanism 23, a plurality of music wires capable of being struck with the hammer assemblies, respectively, and a damper mechanism 24 accompanied with a set of pedals 25. The mechanical piano 21 is thus provided with multiple mechanical lines, however, FIG. 7 shows only one mechanical line including the key 26, the hammer assembly 27 and the music wire 28 in a modeled form.
The automatic player system largely comprises a controller coupled at the input port thereof to a sensor unit 29 and at the output port thereof to a plurality of solenoid-operated actuators 30, and the controller achieves functions as tracing means, sampling means, key velocity calculating means, final hammer velocity deciding means and key touch information producing means.
The automatic player piano thus arranged is shifted between a recording mode of operation and a playback mode of operation. When a human player shifts the automatic player piano into the recording mode of operation and, then, begins to perform a music by successive keying-in operations, the keys are moved from undepressed states toward depressed states along respective traveling paths depending upon key touches, respectively. The forces exerted on the keys are transmitted through the key action mechanism 23 to the hammer assemblies, respectively. Then, the hammer assemblies are driven for rotations toward the music wires, and sounds are mechanically produced upon respective strikes. The key motions from the undepressed states toward the depressed states are respectively detected by the sensor unit 29 and the tracing means produce pieces of a locis information representative of loci of the key motions. After formation of the pieces of the locus information, the sampling means access the pieces of the locus information to extract sections for uniform motions from the loci, respectively. In the sections, the keys respectively travel in uniform motions. When the sections are respectively extracted from the loci of the key motions, the key velocity calculating means decide respective key velocities in the sections, and the final hammer velocity deciding means estimate respective final velocities of the hammer assemblies on the basis of the key velocities. The final hammer velocities are thus estimated from the key velocities, respectively, then the key touch information producing means produce the pieces of the key touch information each representative of the the intensity of the sound produced upon striking the music wires with the hammer assemblies. These pieces of the key touch information are memorized in the controller for a latter usage.
After memorizing the pieces of the key touch information into the controller, the automatic player piano is shifted into the playback mode of operation, then the controller retrieves the pieces of the key touch information in succession. The pieces of the key touch information are used for driving the solenoid-operated actuators 30, and, accordingly, the keys are moved with respective powers tantamount to those transmitted to the key action mechanism 23. Then, the hammer assemblies are driven for rotations toward the music wires, and the sounds are reproduced with the intensities equivalent to those of the original sounds.
Mechanical Arrangement of the Automatic Player Piano
Turning to FIG. 8 of the drawings, there is shown the mechanical arrangement of the automatic player piano illustrated in FIG. 7. The mechanical piano 21 is of the upright type, and the keyboard 31 including the key 26 is mounted on a key bed 32. Each of the keys is swingable with respect to a balance pin 33, however, the key motion is restricted by a back rail cloth member 34 and a front rail member 35. In this instance, the sensor unit 29 is provided on the key bed 32 between the front rail member 35 and the balance pin 33, and the solenoid-operated actuators 30 are mounted on the key bed 32 between the balance pin 33 and the back rail cloth member 34. Though not clearly shown in FIG. 8, the sensor unit 29 is provided with a plurality of photo couplers which are grouped by four and provided in association with the keys, respectively. Each of the keys are accompanied with a shutter plate 36 projecting from the lower surface of the key, and the shutter plate 36 is downwardly moved with the key, so that optical paths of the photo couplers are successively interrupted by the shutter plate 36, thereby detecting the locus of the key motion. Every four photo couplers are provided in association with every key, and the photo couplers grouped by four are referred to as "photo coupler group" in the following description. In each of the photo coupler groups, the four photo couplers are called as first, second, third and fourth photo couplers from the key side to the key bed side. The other mechanical components are well known in the art, and, for this reason, no further description is incorporated in the sake of simplicity.
Arrangement of Controller
On the upper front board of the mechanical piano is exposed the front panel of the controller 37 previously described with reference to FIG. 7.
Turning to FIG. 9 of the drawings, the circuit arrangement of the controller 37 is illustrated and contains three micro-computer units 41, 42 and 43 which are of the single chip type. The micro-computer unit 41 is provided for scanning the sensor unit 29 and periodically checks the sensor unit 29a to see whether or not any photo coupler detects the key motion. When the sensor unit 29a detects the key motion, the micro-computer unit 41 produces a piece of the key touch information as well as a piece of a note information representative of a note assigned to the key depressed by the human player. On the other hand, the micro-computer unit 43 is dedicated to a manipulating panel 44, a MIDI unit 45 and a floppy disk driver unit 46. On the manipulating panel 44 are provided various kinds of switches such as, for example, a power switch, a volume switch, a mode selecting switch and so on, then the micro-computer unit 43 periodically checks the manipulating panel 44 to see whether or not any switch is operated. The manipulating panel 44 is accompanied with a remote controller 47, so that anyone can change the operation mode and the volume from a long distance. The floppy disk driver unit 46 is used for writing and reading out the pieces of the key touch information as well as the pieces of note information into and from a floppy disk 48. If the pedals 25 are operated by the human player, pieces of a pedal actuating information is also memorized into the floppy disk 48. The MIDI unit 45 is provided for a communication with another electronic musical instrument such as, for example, an autorhythmic system. However, the micro-computer unit 42 serves as a supervisor for the other computer units 41 and 43 and, accordingly, transfers the key touch information and the note information from the micro-computer unit 41 to the micro-computer unit 43. The micro-computer unit 42 is further operative to check into the sensor unit 29b associated with the pedals 25 for producing the pieces of the pedal actuating information which is also transferred to the micro-computer unit 43 for the storage. When the pieces of the information are retrieved from the floppy disk 48, the micro-computer unit 43 transfers the pieces of the information to the micro-computer unit 42 which in turn transfers them to a solenoid driver unit 49. The solenoid driver unit 49 is responsive to the pieces of the information and selectively distributes electric power supplied from the power unit 50, thereby causing the solenoid operated actuators 30a and 30b to be actuated. In order to produce the force tantamount to that originally transferred to the key action mechanism 23, the solenoid driver unit 49 changes the duty ratio of the electric power depending upon the piece of the key touch information.
Program Sequence
Turning to FIG. 10, description is made for a program sequence executed by the micro-computer units 41 to 43 of the controller 37. When the power switch turns on, the controller 37 immediately executes an initialized subroutine program P1. Upon completion of the initialized subroutine program, the controller 37 proceeds to step P2 and checks to see whether or not the mode selecting switch is shifted to the recording mode of operation. If the answer to the step P2 is given in the positive, the controller 37 is branched to a recording subroutine program P3 which will be described hereinafter in detail. However, if the answer to the step P2 is given in the negative, the controller 37 further checks to see whether or not the automatic player piano is shifted into the playback mode of operation as by step P4. If the controller 37 acknowledges the playback mode of operation, the answer to the step P4 is given in the positive, then the controller 37 is branched to a playback subroutine program P5 which is also described hereinafter in detail. However, when no operation mode is specified, the answer to the step P4 is given in the negative, then the controller 37 proceeds to step P6. In the step P6, the controller 37 checks to see whether or not any switches except for the mode selecting switch is operated. If the answer to the step P6 is given in the negative, the controller 37 returns to the step P2 and reiterates the loop consisting of the steps P2, P4 and P6 until the answer to any one of the steps P2, P4 and P6 is given in the positive.
When any one of the switches except for the mode selecting switch is operated, the answer to the step P6 is given in the positive, then the controller 37 is branched to a subroutine program for the other switches P7. Whenever any one of the subroutine programs P3, P5 and P7 are completed, the controller 37 proceeds to step P8 to see whether or not the power switch turns off. The answer to the step P8 is given in the negative in so far as the electric power is supplied from the source 50, then the controller 37 returns to the step P2 and reiterates the loop consisting of the step P2 to P8 until the power switch turns off.
As described above, when the mode selecting switch is shifted to the recording mode of operation, the answer to the step P2 is given in the positive, then the controller 37 is branched to the recording subroutine program P3. The program sequence of the recording mode of operation is illustrated in FIGS. 11A and 11B and starts with step P30 where an internal timer of the micro-computer unit 41 begins to count clock pulses. Then, the micro-computer unit 41 writes value "1" into an index register i as by step P31 and, thereafter, checks to see whether or not the photo coupler group associated with the first key detects the key motion as by step P32. Prior to a first keying-in operation, no photo coupler group detects any key motion, so that the answer to the step P32 is given in the negative, then allowing the microcomputer unit 41 to proceed to step P33. In the step P33, the micro-computer unit 41 checks to see whether or not the index register i has been increased to value "88". The index register i is provided for specifying the position of the key currently checked, so that the answer to the step P33 is given in the negative before all of the eighty-eight keys are checked. In this situation, the micro-computer unit 41 proceeds to step P34 to increment the index register i. Upon completion of the step P34, the micro-computer unit 41 returns to the step P32 to check to whether or not the photo coupler group specified by the index register i detects the key motion. The micro-computer unit 41 thus reiterates the loop consisting of the steps P31 to P34 until the answer to the decision step P32 is given in the positive. However, when all of the photo coupler groups are checked by the micro-computer unit 41, the index register i maintains value "88", then the answer to the decision step P33 is given in the positive. With the positive answer for the decision step P33, the micro-computer unit 41 returns to the step P31 to rewrite value "1" into the index register i again and, then, reiterates the loop consisting of the steps P32 to P34 to find the key depressed by the player.
When a performance of a music starts with a first keying-in operation followed by a series of keying-in operations, the answer to the decision step P32 is given in the positive under the index register i matched with the key position subjected to the first keying-in operation. Then, the micro-computer unit 41 proceeds to step P35 and checks to see whether or not the key motion is detected by the first photo coupler. Any key motion is firstly detected by the first photo coupler, so that the answer to the decision step P35 is given in the positive immediately after a fresh keying-in operation. If it is found that the key motion is detected by the first photo coupler, the micro-computer unit 41 proceeds to step P36 and checks to see whether or not a first register assigned the first photo coupler keeps value "0". When the key is moved from the undepressed state toward the depressed state, the first register stores value "0". Then, it is found that the first register keeps value "0", the answer to the decision step P36 is given in the positive, and the microcomputer unit 41 proceeds to step 37 and transfer the counting value of the internal timer to the first register. After the step P37, the micro-computer unit 41 returns to the step P33 to continue the detecting operation.
When the shutter plate 36 interrupts the optical path of the second photo coupler, the answer to the decision step P32 is given in the positive, however, the answer to the decision step P35 is given in the negative. Then, the micro-computer unit 41 proceeds to step P38 and checks to see whether or not the key motion is detected by the second photo coupler. After the detection by the first photo coupler, the key motion is usually detected by the second photo coupler. Then, it is found that the answer to the decision step P 38 is given in the positive. With the positive answer to the decision step P38, the micro-computer proceeds to step P39 to see whether or not a second register assigned the second photo coupler keeps value "0". On the way to the depressed state, the second register also keeps value "0". Then, it is found that the second register keeps value "0", and the answer to the decision step P39 is given in the positive, then the micro-computer unit 41 transfers the counting value of the internal timer to the second register as by step P40. After the completion of the step P40, the micro-computer unit 41 returns to the step P33 so as to continue the detecting operation.
With a lapse of time, the shutter plate 36 interrupts the optical path of the photo coupler again, so that the answer to the decision step P32 is given in the positive, however, the answers to the decision steps P35 and P38 are given in the negative. Then, the micro-computer unit 41 proceeds to step P41 to see whether or not the key motion is detected by the third photo coupler. After the interruption of the optical path of the second photo coupler, the shutter plate 36 usually interrupts the third photo coupler. Then, it is found that the answer to the decision step P41 is given in the positive, and the micro-computer unit 41 checks into a third register assigned to the third photo coupler to see whether or not value "0" is stored in the third register as by step P42. Since the third register keeps value "0" upon the depression of the key, it is found that the third register keeps value "0", and the micro-computer unit 41 transfers the counting value of the internal timer to the third register as by step P43, then returning to the step P33.
After a while, the shutter plate 36 interrupts the optical path of the photo coupler again, so that the answer to the decision step P32 is given in the positive, however, the answers to the decision steps P35, P38 and P41 are given in the negative. Then, the micro-computer unit 41 proceeds to step P44 to see whether or not the key motion is detected by the fourth photo coupler. After the interruption of the optical path of the third photo coupler, the shutter plate 36 usually interrupts the fourth photo coupler. Then, it is found that the answer to the decision step P44 is given in the positive, and the micro-computer unit 41 checks into a fourth register assigned to the fourth photo coupler to see whether or not value "0" is stored in the fourth register as by step P45. The fourth register has been reset to value "0", so that it is found that the fourth register keeps value "0", and the micro-computer unit 41 transfers the counting value of the internal timer to the fourth register as by step P46, then returning to the step P33.
In this manner, the counting values are successively stored in the first to fourth registers when the key is fully depressed, however, if the key is partially depressed in the shallow touch, the key motion may not be detected by the fourth photo coupler. In any case, the registers store the respective counting values which are indicative of the locus of the key motion. For this reason, the tracing means are achieved by the steps P30 to P46.
When the key is released, the key is moved toward the undepressed state, and the shutter plate 36 interrupts the optical path of the photo coupler again. Then, the answer to the decision step 32 is given in the positive, and any one of the decision steps P35, P38, P41 and P44 is given in the positive. Then, the micro-computer unit 41 proceeds to step P47 and calculates time intervals T1, T2 and T3 between the first and second photo couplers, between the second and third photo couplers and between the third and fourth photo couplers, respectively. After the calculation, the micro-computer 41 proceeds to step P48 and resets the first and second registers for the subsequent keying-in operation. The micro-computer unit 41 compares the time intervals T1 to T3 with an internal table (not shown ) to decide the kind of the keying-in operation as by step P49 and, then, selects one of the time intervals depending upon the kind of the keying-in operation decided on the basis of the time intervals as by step P50. The selected time interval stands for the section where the key moves in the uniform motion. Then, the steps P47 to P50 as a whole achieve the function of the sampling means.
When the time interval is selected, the micro-computer unit 41 decides the key velocity on the basis of the selected time interval as by step P51. Then, the key velocity calculating means are achieved by the step P51. When the key velocity is decided, the micro-computer unit 41 estimates the final hammer velocity and, then, produces a piece of the key touch information as by step P52. Then, the final hammer velocity deciding means as well as the key touch information producing means are achieved by the step P52. Thus, the piece of the key touch information is produced by the micro-computer unit 41, then the piece of the key touch information is transferred to the micro-computer unit 43 which in turn transfers the piece of the key touch information to the floppy disk driver unit 46 for storing into the floppy disk 48 as by step P53. If the piece of the key touch information is thus memorized into the floppy disk 48, the micro-computer unit 41 returns to the step P33 for the subsequent keying-in operation. In this way, the micro-computer unit 41 repeats the loop consisting of the steps P30 to P53 until the automatic player piano is escaped from the recording mode of operation. Additionally, the detecting operation will be masked from the completion of the step P48 to the return to the undepressed state.
In the program sequence described above, all of the time intervals are calculated in the step P47, however, some kinds of the keying-in operation tends to be characterized by only one time interval. For this reason, the micro-computer unit 41 may calculate the time interval T1 after the step P40 and check to see if or not the time interval T1 features the keying-in operation. If the kind of the keying-in operation is decided from the time interval only, no calculation is carried out for the time intervals T2 and T3. If not, the subsequent time interval is calculated. Thus, the time intervals are sequentially calculated from one to another, the micro-computer unit 41 will be certainly decreased in the amount of job.
As described in connection with the problem of the prior-art, some users request the piano manufacturer to remodel the mechanical piano into an automatic player piano. The component members are not standardized, however, the space between the keyboard and the key bed are substantially identical with one another. Then, it is preferable to accommodate the sensor units and the actuators in the space in view of the standardization.
Second embodiment
Turning to FIG. 12 of the drawings, there is shown the arrangement of a part of an automatic player piano embodying the present invention. The automatic player piano partially illustrated in FIG. 12 is similar in arrangement to the automatic player piano illustrated in FIG. 8 except for a sensor unit 61 and solenoid-operated actuators 62, so that description is focused upon the sensor unit 61 and the solenoid-operated actuators 62, and the other component members are denoted by like reference numerals designating the corresponding component members of the automatic player piano illustrated in FIG. 8.
As illustrated in detail in FIG. 13, the sensor unit 61 largely comprises an encoder plate 63 and two photo couplers 64 and 65 supported by a bracket member 66. Two small windows 67 and 68 are formed in the encoder plate 63 in such a manner that optical paths of the photo couplers 64 and 65 intermittingly pass the windows 67 and 68, respectively, while the key 26 is moved toward the depressed state. In this instance, each of the windows is about 0.5 millimeter in height. Since the windows 67 and 68 are slightly deviated from each other as seen from FIG. 14, the optical path of the photo coupler 65 firstly extends through the window 68 on the way to the depressed state, and, then, both of the optical paths are established through the windows 68 and 67 for the photo couplers 65 and 64. If the key 26 is further moved, the optical path of the photo coupler 65 is blocked by the encoder plate 63, but the optical path of the photo coupler 64 still extends through the window 67. However, if the key 26 is further advanced, both of the optical paths are blocked by the encoder plate 63. Thus, the sensor unit 61 is capable of producing four bit patterns or a two bits of an encoded signal, which is summarized in the following table, with only two photo couplers. This results in reduction in the production cost. In the sensor unit 61 shown in FIG. 13, the photo couplers 64 and 65 are arranged in juxtaposition, but the windows are slightly deviated from each other. However, the photo couplers may be arranged in a deviated manner with the juxtaposed windows in another implementation.
TABLE______________________________________ Optical path of Optical path of Photo Coupler 64 Photo Coupler 65______________________________________First Position Blocked EstablishedSecond Position Established EstablishedThird Position Established BlockedFourth Position Blocked Blocked______________________________________
If the two bits of the encoded signal is supplied to the controller, the controller can trace the locus of the key motion on the basis of the four bit patterns. For this reason, the micro-computer unit 41 periodically checks to see whether or not the bit patter is varied for making decisions instead of the steps p35, P38, P41 and P44.
The solenoid-operated actuators 62 are supported by a bracket member and accompanied with lever members 69, respectively. Each of the lever members 69 is rotatably supported at an intermediate portion thereof by the bracket member and engaged at the rear end portion thereof with a plunger 70. The plunger 70 passes through a solenoid, so that the plunger 70 is projectable from the bracket member. The lever member 69 is engaged at the front end portion thereof with the shutter plate 36, and, for this reason, the key 26 is pulled down upon the projection of the plunger 70.
Third embodiment
Turning to FIG. 15 of the drawings, there is shown an encoder plate 71 incorporated in a sensor unit which in turn is provided in an automatic player piano embodying the present invention. The encoder plate 71 cooperates with three photo couplers 72, 73 and 74 which are accompanied with a signal processing circuit illustrated in FIG. 16. However, the other components are similar to those of the automatic player piano shown in FIG. 8, so that the corresponding components are referred to with like reference numerals, however, no detailed description is made.
The encoder plate 71 has a plurality of windows 75 to 81 arranged in three lines, All of the windows 75 to 81 are equal in width to one another. However, the windows in each line are different in height from the windows in another line. Namely, the windows 75 to 78 are equal in height to one another but different from the other windows 79 to 81. Similarly, the window 79 is equal in height to the window 80 but different from another window. The windows in the respective lines intermittingly pass the optical paths of the photo couplers 72, 73 and 74, respectively, and the three photo couplers 72 to 74 are arranged in a juxtaposed manner, so that three bits of an encoder signal is produced by the photo couplers 72 to 74 when the key 26 is moved from the undepressed state toward the depressed state. This results in that the controller 37 can discriminate eight positions on the locus of the key motion from one another.
The three bit encoder signal is supplied from the photo couplers 72, 73 and 74 to the signal processing circuit, and the signal processing circuit largely comprises eight flip flop circuits 82 to 89 (each of which is abbreviated as "FF" in FIG. 16 ) and eight AND gates 90 to 97 which are of the three input node type. The three input nodes of each AND gate are selectively accompanied with an inverter circuit or inverter circuits (which are indicated by small bubbles ), and, for this reason, the AND gates 90 to 97 sequentially produces output signals. The output signals of the AND gates 90 to 97 are respectively supplied to the set nodes of the flip flop circuits 82 to 89, however, the reset nodes of the flip flop circuits 2 to 89 are supplied with the output signals of the adjacent AND gates 91 to 90, respectively. The flip flop circuits 82 to 89 thus arranged are sequentially shifted to the set states and, accordingly, produces an eight bit position signal. The bit string of the position signal is varied by advancement of the key 26, so that the micro-computer unit 41 can trace the locus of the key motion with the variation of the bit string.
Fourth embodiment
Turning to FIG. 17 of the drawings, still another encoder plate 100 is illustrated. The encoder plate 100 is provided in association with two photo couplers 101 and 102 and, accordingly, formed with two lines of windows 103 to 110. All of the windows 103 to 110 are identical in shape with one another and spaced at a regular interval, however, these windows are arranged in a staggered manner. The photo couplers 101 and 102 are respectively coupled to both pulse generators 111 and 112 as shown in FIG. 18, and the count pulses produced by the generators 111 and 112 are supplied to the count-up node and the count-down node of a counter circuit 113, respectively. The signal processing circuit thus arranged is operative to increment or decrement the counting value which is indicative of discrete positions on the locus of the key motion. Since the windows 103 to 106 are arranged in the staggered manner with respect to the windows 107 to 110, the pulse generator 111 produces the clock pulses on the way to the depressed state, however, the pulse generator 112 keeps silent, so that the counter circuit 113 increments the counting value with time. On the other hand, when the key is released, the pulse generator 112 produces the clock pulses, however, the no clock pulse is supplied to the count-up node of the counter circuit 113, then the counter circuit 113 decrements the value. Thus, the counting value is incremented or decremented depending upon the direction of the key motion. Then, the micro-computer unit 41 can trace the locus of the key motion with the output signal of the counter circuit 113 as will be understood from the waveforms in FIG. 19.
Although particular embodiment of the present invention have been shown and described, it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present invention. For example, the actomatic player system according to the present invention is applicable to a mechanical piano of the grand type. | 4y
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FIELD OF THE INVENTION
This invention relates to an apparatus and method for reducing particulates and certain gasses in gas streams, particularly in exhaust streams from combustion devices.
BACKGROUND OF THE INVENTION
In the prior-art there are devices, using steam or water scrubbing, which are used to remove particulates from exhaust gasses. While these devices are effective to some degree in removing particulates and gasses from exhaust gas streams, stricter standards for exhaust emissions have created a need for more efficient pollution removal.
Furthermore, many devices of the prior art include moving parts, e.g., dispersing wheels, fans, and the like, which contributes to the building and maintaining costs of the device. In addition, many have a specialized structure and can only be applied to certain exhaust or waste-gas systems and not to existing installations without extensive rebuilding.
In Chemical Engineers' Handbook (5th Edition) by R. H. Perry, and Cecil H. Chilton, on pages 20-94 to 20-103 are disclosed various gas scrubbers which use water sprays for removing particulates from gas streams. Adding steam to the aerosol created by the water spray is also disclosed. (See page 20-96.)
U.S. Pat. No. 3,139,331 to Boudreau discloses a smoke cleansing apparatus in which the smoke is wetted with water or steam while being directed through a coiled duct. Centriftigal force causes the smoke particles to be carried away by the condensed steam to a discharge port.
U.S. Pat. No. 3,582,051 to Klein discloses a smoke cleaning apparatus wherein smoke is first directed through conical baffle of closely spaced overlapping rings, which holds back larger particles, and then through helical baffles where an apertured spray pipe sprays water to cool the smoke and fumes and entrap further particles in the smoke.
U.S. Pat. No. 3,605,386 to Erwin discloses a pollution eliminator comprising a section with steam injectors followed by a section with water injecters. In the steam injector section, baffles confine the exhaust to ensure saturation of exhaust solids.
U.S. Pat. No. 3,920,423 to Ross discloses a steam scrubber comprising steam injecters, which inject steam from a conduit in the center of a tank through which smoke is directed.
U.S. Pat. No. 3,888,642 to Toyama discloses an exhaust-stack scrubber attachment comprising a steam jet for mingling the exhaust stream with steam upstream from off-set filter baffles.
U.S. Pat. No. 4,017,277 to VanDyke, Sr. et al. discloses a direct contact water heating system that comprises transferring heat to water from flue gasses and stripping the water of dissolved gasses with steam.
U.S. Pat. No. 4,113,453 to Rector discloses an anti-pollution device comprising a nozzle directing steam upwardly into stack, with a series of cooling chambers to condense pollutant containing steam above the nozzle.
U.S. Pat. No. 4,624,190 to Cappi discloses an apparatus for disposal of flue gas that scrubs the flue gas with water from nozzles.
In some prior art devices, the water or steam is mechanically dispersed in the path of smoke. For example, U.S. Pat. No. 750,351 to Doyle discloses a device for removing smoke, which comprises water jets directed upwardly with sprayer or spreader plates above the jets to deflect the water spray downward.
U.S. Pat. No. 4,257,792 to Cremo discloses a stream-pressured smoke eliminator that comprises a steam supply fed to a steam-jet-operated star wheel. The star wheel dispenses a sheet-like layer of steam to intercept smoke rising through the eliminator. The eliminator can be assembled as a unit, which is inserted into a smoke-stack by means of a helicopter.
U.S. Pat. No. 3,760,567 to Stalker discloses a smoke cleaner that uses extractor fans to draw the smoke upward. Water is directed to the underside of the fan, which sprays the water outwardly in a spray. Steam or hot water may also be directed against the fan to remove heavy pollution constituents such as oils and tars (col. 3, lines 53 to 68).
Another device for mechanically dispersing a water stream is disclosed in U.S. Pat. No. 1,537,065 to Burdin, which describes a humidifier comprising a water nozzle and an angularly disposed adjustable target plate. In operation, water under pressure impinges against the deflecting plate and breaks the water into a spray. The outer line of the spray, after striking the bottom of the chamber, may rebound and break up further. (See page 2, lines 52 to 59).
OBJECTS OF THE INVENTION
It is, therefore, an object of the invention to provide a device that efficiently removes particulate materials from gas streams.
It is also an object of the invention to provide a device that is relatively simple to maintain and includes a minimum of moving parts for its operation.
Further objects of the invention will become evident in the description below.
SUMMARY OF THE INVENTION
An embodiment of the invention is an apparatus for removing pollutants from a gas stream comprising;
(a) a means for generating saturated steam,
(b) a primary deflector plate,
(c) a secondary deflector plate,
(d) a steam jet means communicating with the steam generating means for directing a spray of steam against the primary deflector plate to disperse a portion of the spray and rebound the spray off of the primary deflector plate against the secondary deflector plate to disperse at least a portion of the spray directed to the secondary deflector plate, the placement of the primary deflector plate and secondary deflector plate adapted such that the dispersed spray from the primary and secondary deflector plates forms an aerosol in the path of the gas stream,
(e) a means for recovering water which condenses from the aerosol, the water containing pollutants from the gas stream absorbed by the aerosol.
Another embodiment of the invention is a method for removing pollutants from a gas stream comprising directing a spray of steam against a primary deflector plate to disperse a portion of the spray and repel the spray off of the primary deflector plate against a secondary deflector plate to disperse at least a portion of the spray rebounded against the secondary deflector plate, the placement of the primary deflector plate and secondary deflector plate adapted such that the dispersed spray from the primary and secondary deflector plates forms an aerosol in the path of the gas stream, allowing the aerosol to condense into water, and recovering the condensed water.
The mean for generating saturated steam may be any suitable means for generating saturated steam known in the art. Preferably, the steam generation means uses heat from the exhaust gasses as an energy source, as more fully described below.
The steam jet means communicates with the source of steam to provide a spray which is directed against the primary deflector plate. The force of the spray against the primary deflector plate fractures or disperses a portion of the spray into a fine mist or aerosol with undispersed portions of the spray being rebounded, repelled, bounced, or ricochetted off of the primary deflector plate and upon the secondary deflector plate. Directing the rebounded spray against the secondary deflector plate further disperses the spray, generating more dispersed mist or aerosol. Further surfaces may be provided, upon which steam rebounded from the deflector plates or other surfaces can be directed and dispersed. It has been found that the multiple bouncing of the steam stream between surfaces disperses the stream more effectively than a mere sprayer alone or even a sprayer with a single deflecting surface. It has also been found that directing water (as opposed to steam) sprays against multiple surfaces is not as effective in creating an aerosol for removing pollutants from the gas stream. The multiple deflector plates combined with steam as the stream being dispersed is materially more effective in creating a mist or aerosol for removing pollutants from gas streams.
The impact of the spray against the primary and secondary deflector plates creates a steam mist or aerosol in the path of the gas stream. Preferably, the spray rebounded from the primary deflector plate toward the secondary deflector plate is directed across the path of the gas stream, which places the gas stream between primary and secondary deflector plates and insures that aerosol created by impact of the steam streams will be in the path of the gas stream. The small droplets created in the aerosol by the rebounded and dispersed steam absorbs pollutants from the gas stream. The pollutants are accordingly retained in the steam as it condenses and are recovered with the water condensed from the steam. Preferably the pollutants are removed from the condensed water and the water recycled as a feed water source to the means for generating saturated steam.
By "pollutants" is meant particulate materials to be removed from the gas stream, as well as gasses that are sufficiently soluble in the steam aerosol to be removed. The gas stream may be from any chemical or industrial process, which produces gas streams with undesirable pollutants, preferably gas streams of sufficient temperature to provide at least a portion of the energy for generating steam for the stream sprays. In the preferred application, the present invention is used in conjunction with combustion processes, more particularly incinerators, where the pollutants are combustion products, such as soot, ash, and the like. The present invention may also be applied to other combustion processes, such as exhaust streams from boilers and internal combustion engines.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified elevational cross-section of an apparatus of the invention.
FIG. 2 is an elevational cross-section of another embodiment of the invention.
FIG. 3 is a detail cross-section of the preheater assembly of FIG. 2.
FIG. 4 is a detail cross-section of the inner core assembly of FIG. 2.
FIG. 4a is a detail view of an inner core assembly that can be used as an alternate to that of FIG. 4.
FIG. 5 is an exploded view of the outer assembly of FIG. 2.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, an apparatus of the present invention 101 is placed over a source of exhaust gas (not shown), such as an incinerator, or the like, with the exhaust gas stream (shown by the solid stream arrows 102) entering gas inlet 103 from below and passing upwardly through the apparatus 101. Multiple sets of plates 104, each comprising a primary deflector plate 105 and a secondary deflector plate 107, are placed such that the gas stream passes between the primary deflector plates 105 and secondary deflector plates 107.
A source of steam (not shown) communicates with steam jets 109, each of which direct a steam spray against a primary deflector plate 105. A portion of the spray is scattered or dispersed upon impingement on the primary deflector plate and is bounced, rebounded, ricochetted, or repelled toward the secondary deflector plate 107. The rebounded stream impinges upon the secondary deflector plate 107, which disperses steam from the rebounded spray.
In the illustrated embodiment, the primary deflector plates 105 and the steam jets are mounted on a central pedestal 111, which also functions as a manifold and feed conduit for the steam jets 109. While any orientation can be used, preferably the central pedestal 111 is vertical with the primary deflector plates 105 mounted horizontally at their center. The secondary deflector plates 107 are mounted in horizontal planes essentially parallel to the primary deflector plates 105 and in a staggered relationship to the primary deflector plates 105, i.e., the positions along a vertical axis of the secondary plates 107 being between the positions of the primary plates 105. Preferably the staggered secondary deflector plates 107 are also equidistant along a vertical axis from the two adjoining primary deflector plates 105, which provides alignment for the proper rebounding of the steam spray 113 and provides a path for the gas stream between the deflector plates 105, 107.
The steam jets 109 are mounted such that the axis of the steam spray 113 is directed against a primary deflector plate 105, preferably at an acute angle. A suitable angle is between about 20° and about 45°, preferably between about 25° and about 35°, more preferably about 30°, to the plane of the primary deflector plate 105. An acute angle is preferred as this permits the stream to be more easily rebounded off of the primary deflector plate 105 and towards the secondary deflector plate 107. Shown in FIG. 1 is the axis (shown as dotted line) of each spray 113 from each jet 109, as it is rebounded from the primary and secondary deflector plates 105, 107.
It is contemplated that only one set 104 of plates comprising a primary deflector plate 105 and a secondary deflector plate 107 be provided in an apparatus of the invention, but it is preferred to have multiple sets 104 arranged in series as illustrated. The preferred number of sets depends on the concentration of the pollutants in the entering gas stream and the desired level of purity desired for outgoing purified gas stream. In a garbage incinerator application, four sets have been found suitable.
For each primary deflector plate 105, one or more steam jets 109 are provided. In a preferred embodiment as illustrated, multiple jets 109 are mounted radially on the central pedestal 111 and directed outward and onto the primary deflector plate 105.
The shape of the primary and secondary deflector plates 105,107 may be any suitable shape. Preferably the primary deflector plates 105 are flat plates of a circular shape. The secondary deflector plates 107 are preferably flat plates annular in shape with a central circular aperture slightly larger in diameter than the primary deflector plate, i.e., the difference in diameter is just large enough so that the primary deflector plate can be moved through the aperture without interference. As further described below, this permits a modular construction, which is advantageous for assembly and maintenance. Other configurations are contemplated, such as primary and secondary deflector plates of other shapes, e.g., ovoid, quadratic, or polyhedral, or deflector plates or with curved surfaces. In addition, the positions of the primary deflector plate and secondary deflector plate may be reversed, i.e., the primary plates as outer annular plates the secondary plates as inner circular plates with the steam jets moved to the outside as appropriate.
The steam is provided at a pressure sufficient to repel or rebound the steam from the steam jet 109 of the primary deflector plate 105 and then the secondary deflector plate 107. Preferably the pressure is between about 50 psig (350 ×10 3 Pa) and about 1500 psig (10×10 6 Pa). An essential element of the invention is that the stream comprise high-pressure saturated steam, i.e., a stream of gaseous water containing liquid droplets. It has been found that high-pressure steam is significantly more effective for removing polluting materials than high-pressure water when used in conjunction with primary and secondary deflector plates.
The impingement of the spray of steam upon the primary and secondary deflector plates 105, 107 creates an aerosol in the path of the exhaust stream. The gas stream passes through aerosol and the droplets of water in the aerosol absorb polluting materials from the gas stream. The steam of the aerosol condenses and the polluting materials that have been absorbed are contained in the condensed water, which can then be recovered. The means of recovery may be by any suitable means for collecting and recovering condensate. In FIG. 1, the secondary deflector plates 107 have holes 114 through which condensed water can flow and drain from the secondary deflector plates 107. The condensed water flows through the holes 114 into an outer reservoir 115, which can be emptied through a drain 117.
FIGS. 2 to 6 shows an embodiment of the invention as applied commercially to a garbage incinerator, or the like, and illustrates means for recycling the water for steam generation, and means for recovering the pollutants from the gas stream.
Referring to FIG. 2, apparatus of the invention 201 is placed over the outlet of a smoke stack 203 of an incinerator 204. Exhaust gas passes up the smoke stack 203 and into a bottom inlet 205 of the apparatus 201. Water is pumped from pump feed chamber 207 by pump 209 through feed chamber outlet lines 211 and through water inlet line 213 into preheater assembly 215. The pump 209, is preferably a high-pressure type to pump against the high steam pressures generated in the apparatus as previously recited.
Referring to FIG. 3, which is a detail of the preheater assembly 215, water passes through preheater assembly 215 and out through preheater outlet 217. The water then passes into inner core assembly 219 (FIG. 2) where the water is heated by heat from the exhaust gas. Heat is also provided to the inner core assembly 219 for steam generation by the preheater assembly 215. The preheater assembly 215 assists in maintaining the inner core at a sufficiently high operating temperature during fluctuations of exhaust gas temperature, which may by produced by operation of the incinerator. Preheater assembly comprises a bumer 221, with a combustion chamber 223 and air inlet 225. The exhaust from the combustion chamber 223 passes up through ports 227 in the chamber into the exhaust gas stream. The combustion chamber 223 is preferably placed centrally and directly under the inner core 219 in FIG. 2, to minimize restriction to flow of the exhaust gasses.
The water outlet 217 of the preheater assembly 215 passed through a machined cone 229 of solid metal with the outlet 217 passing upwards into and through the apex of the cone 229. The machined cone 229 provides a mating surface and also a support for the inner core assembly 219.
Referring again to FIG. 2, the inner core assembly 219 is placed centrally in an exhaust chamber 241. The inner core assembly 219 comprises a heat exchange section 233 and the spray section 235. The heat exchange section 233 transfers heat from the gas stream, which now includes exhaust gasses from the incinerator and exhaust from the preheater assembly 215, to the water passing through the inner core.
Referring to FIG. 4, which is a detail of the inner core assembly 219, cone inlet 231 is machined to join with the machined cone 229 of the preheater assembly 215 and provide a seal to the pressurized steam passing from the preheater assembly 215 to the inner core assembly 219. Water coming into the inner core assembly 219 enters first a pressure chamber 237 in the heat exchange section 233, where the water is heated to steam. The pressure chamber 237 is tube surrounded by an oil jacket 239 filled with a heat exchange liquid, preferably an oil. The hot gasses in the gas stream pass up along the outer wall of the oil jacket 239 and heat is transferred from the gas stream into the heat exchange medium, which 40 in turn passes to the water in the pressure chamber 237. In the pressure chamber 237, the water is thereby heated sufficiently to boil to steam, so the pressure chamber 237 contains two regions, a lower containing liquid water, and an upper of steam. The steam generated in the pressure chamber 237 passes out through the top of the heat exchange section 233 through a reducer 244 into the spray section 235.
The steam entering the spray section 235 passes into a central manifold tube 243 in the form of a vertically aligned central pedestal to which is connected to steam jets, atomizers, or injectors 245 for spraying the steam upwards at an acute angle to primary deflector plates 247. In the illustrated embodiment there are four primary deflector plates 247, each associated with fourjets 245 mounted horizontally on the manifold tube 243 below each primary deflector plate 247. The deflector plates 247 are circular flat plates mounted at the center at the manifold tube 243 and extending perpendicularly from the manifold tube 243. The jets 245 are spaced radially at equal 90° increments and directed to spray outward and upward from the manifold tube 243 and onto the primary deflector plates 247. The angle of the axis of the spray from the jet 245 to the surface of the primary deflector plate is about 30°. To prevent the steam pressure from rising beyond safe limit, a pressure valve 249 is mounted on the top of the manifold tube 243. The primary deflector plates 247 are flat plates of a circular shape. The secondary deflector plates 263 are flat plates annular in shape with a central circular aperture slightly larger in diameter than the primary deflector plate 247.
A splash plate 251 is mounted below the primary deflector plates and is the same shape and diameter as the deflector plates. Attached to the splash plates are support brackets 253 for mounting the inner core. (Mounting of the inner core is described in more detail below.) The splash plate also keeps moisture from entering the exhaust chamber.
FIG. 4a shows an alternate inner core assembly, which can be used in place of the inner core assembly shown in FIG. 4. In FIG. 4a the inner core assembly 419 comprises cone inlet 431, beat exchange section 433, spray section 435, pressure chamber 437, manifold tube 443, reducer 444, steam jets 445, primary deflector plates 447, pressure valve 449, splash plate 451, and mounting brackets 453, constructed the same as in FIG. 4. Referring to FIG. 4a, the heat exchange section 433 is constructed with one or more helical tubes 455 extended from the bottom of the pressure chamber 437, up through the exhaust chamber 241 (FIG. 2), and into the top of the pressure chamber 437. In this embodiment, heat from the gas stream is transferred to the water in the pressure chamber 437 by means of the helical tube 455. Liquid water enters a helical tube 455 at the bottom, is heated and turns into steam as it passes up though the helical tube 455 and enters the upper steam section of the pressure chamber 437. Preferably the coil diameter of the helical tube 455 varies to cover the width of the exhaust chamber 241. As illustrated, the coil diameter of the helical tube 455 at the bottom is small, slightly larger than the outer diameter of the pressure chamber 437. As it coils upwards the coil diameter enlarges to near the inside diameter of the exhaust chamber 241, decreases, and then enlarges and decreases again before it enters into the pressure chamber 437.
Referring to FIG. 2 and also FIG. 5, which is an exploded view of the outer assembly, the outer assembly comprises a center section 254, a head assembly 255, a top cap 257, and water treatment assembly 258. The center section 254 comprises the exhaust gas chamber 241 for the passage of the exhaust gasses and provide a space in which the inner core 219 fits. The base of the center section 254 mounts on the top of the pre-heater assembly 215, such that the mixed exhaust from the preheater assembly 215 and the incinerator 204 flows into the exhaust chamber 241 of the center section 254. At the top of the exhaust chamber 241 are exhaust ports 259 through which the rising gas stream passes after passing the heat exchange section 233 of the inner core 219. The gas stream then passes into the spray chamber 261, which is within the head assembly 255 and contains the spray section 235 of the inner core 219. The exhaust ports 259 are dimensioned to have at least the same area for the passage of the gas stream as that of the exhaust chamber 214, so that there is minimal impediment to the flow of the gas stream.
At top of the center section 254 is mounted the head assembly 255. The head assembly 255 has the same outer diameter as that of the center section 254. The head assembly 255 comprises secondary deflector plates 263, which in the assembled apparatus (FIG. 2) are in a staggered position relative to the primary deflector plates 247, such that there is a secondary deflector plate 263 mounted below and outside of each primary deflector plate 247 to permit the steam spray rebounded from the primary deflector plate 247 to impinge upon the secondary deflector plate 263 and provide a path for the gas stream.
The secondary deflector plates have holes 265, which permits condensed steam containing pollutants removed from the gas stream to flow downward through the head assembly 255 and collect as liquid water 273 in an outer reservoir 267 in the center section 254. The outer reservoir 267 is defined by an outer annular wall 269 and the outer wall of the exhaust chamber 271.
The top cap 257 is placed on the top or exit of the head assembly 255 by means of suitable brackets, and comprises an exit flue 291 for release of the cleansed exhaust gas stream and also the vapor that was not condensed and collected in the outer reservoir 267, as described above.
From the outer reservoir 267 water is removed through a discharge conduit 275, and the water can then be disposed of or processed as desired. Preferably the discharge conduit 275 directs the water to a means for separating out the pollutants removed from the gas stream and also a means for recycling the water as a source for steam generation. In this preferred embodiment, most of the outer reservoir 267 is maintained frill of the liquid water 273 with the outer reservoir 267 surrounding at least a portion of the exhaust chamber 214, as illustrated. This allows the water 273 in the outer reservoir 267 to capture some heat that would normally be lost from the exhaust chamber 214, which can be used to warm the water source for steam generation.
The water treatment assembly 258 comprises a float or pump feed chamber 207, high-pressure pump 209, and purification unit 281 (shown only as a block in FIG. 2). The pump feed chamber 207 provides the water feed source for the high pressure pump 209, which in turn supplies the pressurized water to the inner core 219. The pump feed chamber 207 also communicates with the outer reservoir 267 through cross-over conduits 283. The cross-over conduits 283 allow the water level of the outer reservoir 267 to be controlled by the level of water in the pump feed chamber 207. In the top of the pump feed chamber 207 is a float valve 285 which controls the level of water by controlling water flow through the water input conduit 287 into the pump feed chamber 207. The cross-over conduits 283 also allow heated water from the outer reservoir 267 to mix with the water in the pump feed chamber 207, and thereby heat the water feed for the inner core assembly 219, thus recycling some of the heat for heat generation. Where the cross-over conduits 283 enter the pump feed chamber 207, annular filters 293 are provided to prevent the particular pollutants in the outer reservoir 267 from entering the pump feed chamber 207 and possibly fouling the high pressure pump 209, steam jets 245, or the like.
Water from the pump feed chamber 207 is directed to high pressure pump 209 via feed chamber outlet lines 21 1. The high pressure pump 209 forces the water, at the desired pressure, tip through the preheater assembly 215 and into the inner core assembly 219, as previously described.
The water from the discharge conduit 275 of the outer reservoir 267 is recycled into the pump feed chamber 207 by passing the water through the purification unit 281, which removes a substantial portion of the pollutants from the water, particularly the particulates, rendering the water a suitable source for steam generation. The purification unit may use any suitable process for treating water. Preferably, the purification unit comprises a series of settling tanks or basins (three or more in series have been found suitable) followed by a filtration unit. In each of the settling tanks the water cools, which accelerates settlement of particulates. The filtration unit may be any suitable filtration means for removing the fine residual particulates not removed in the settling tanks. The purified water is then fed by appropriate means, e.g., a pump, or gravity feed, through the water input conduit 287 into the pump feed chamber 207. The pollutants collected in the settling tanks can be recovered and dried, and used as a fuel, if appropriate, or otherwise processed to recover any fuel or mineral values.
The constriction illustrated in FIGS. 2 to 5 is a modular construction, which permits easy assembly and disassembly for maintenance. The primary deflector plates 247 are dimensioned slightly less in diameter than the aperture for the annular secondary deflector plates 263. This allows the head assembly 255 to be easily removed by first removing the top cap 257 and lifting the head assembly 255 vertically from the inner core assembly 219 and the center section. This provides easy access to the secondary deflector plates 263, primary deflector plates 247, and spray section 235, and the steam jets 245. The inner core assembly 219 is maintained in position by dimensioning the splash plate 251 to closely fit into the top of the exhaust chamber 214 of the center section 254, just above the exhaust ports 259. The inner core is held in place by its weight. At the bottom of the splash plate 251 there is a short sleeve bracket or brackets 253 that slide over the top of the exhaust chamber 241 to prevent the inner core 219 from sliding off center.
The cone inlet 231 of the inner core assembly 219 and machined cone 229 of the preheater assembly 215 are machined to fit together and provide a sealed fitting to the pressurized water from the weight of the inner core 219 on the fitting. Therefore, to remove the inner core 219, it is merely lifted up through the exhaust chamber after removing any brackets 253 holding the splash plate 251 to the center section 254. The center section 254 can then be removed providing access to the components of the preheater 215. The components of the water treatment assembly 258, are connected by conduits and appropriate shut off valves that permit the component to be easily removed and maintained as required.
Referring to FIG. 2, the apparatus of the invention preferably includes a gas separator or extractor 295. Gasses that collect in the outer reservoir are drawn through line 297, and separated into heavy gasses, through line 298, and light gasses through 299.
The dimensions of the apparatus of the invention are chosen for the particular application, considering among other things, the level of pollutants, the gas flow, size of the exhaust stack. In a particular embodiment similar to that illustrated in FIGS. 2 to 5, the primary deflector plates 247 were spaced about 8 inches (20 cm) from each other. The secondary deflector plates 263 were also spaced about 8 inches (20 cm) from each and placed in staggered relationship with the primary deflector plates 247, i.e, the vertical position of a secondary deflector plate 263 about 4 inches (10 cm) from adjacent primary deflector plates 247. The outer diameter of the center section 254 was about 20 inches (50 cm), and the aperture in the secondary deflector plates 263 was about 10 inches (25 cm). The steam jets 245 were oriented to direct the steam near the outer edge of the primary deflector plate 247 at an angle of 30° to the horizontal, such that substantial portion of the steam jet was rebounded and directed to the secondary deflector plate 263.
The apparatus of the invention may be constructed of any suitable material, such as steel, stainless steel, non-ferrous metals, high-performance polymers, and the like. Preferably, a non-corrosive material is used in the high-temperature regions exposed to a corrosive gas stream.
To accommodate large volumes of gas or exhaust gas stacks of a large diameter, a plurality of units of the apparatus of the invention may be ganged or mounted in parallel. For example, a suitable gang includes from 2 to 7 units.
While this invention has been described with reference to certain specific embodiments and examples, it will be recognized by those skilled in the art that many variations are possible without departing from the scope and spirit of this invention, and that the invention, as described by the claims, is intended to cover all changes and modifications of the invention that do not depart from the spirit of the invention. | 4y
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FIELD OF THE INVENTION
The present invention relates to a gas supplying apparatus and a gas substitution method, more particularly to a gas supplying apparatus and a gas substitution method capable of carrying out gas substitution efficiently when plural kinds of high-purity gases are switched and supplied.
DESCRIPTION OF THE PRIOR ART
In the field of semiconductor industry, many gas-phase processes have been used in a device manufacturing process. It has been understood that if a very small amount of gas impurities exists in a high-purity bulk gas used in the gas-phase processes, the gas impurities have bad effects on the device performance. Therefore, a gas system for supplying high-purity gases is needed to avoid the situation where the gas system becomes a contaminating source of the impurities. Furthermore, the gas system must be capable of carrying out rapid substitution of a high-purity gas and of decreasing impurity concentration in a short time when a different high-purity gas commences to be supplied.
In the field of observing and analyzing impurity concentration in a high-purity gas, a high-sensitivity gas analyzing system using an analyzer such as an atmosphere pressure ionization mass spectrometer (AIPMS) if often employed. In the high-sensitivity gas analyzing system, there is a necessity that various kinds of gases be sequentially analyzed in a short time by using same analyzer. For this, since a prior gas having flowed becomes an impurity when gases are switched, rapid substitution in the gas system by a sample gas is required for a sampling system.
Generally, there exists, in a gas system, coupling parts or branching parts of pipes with a gas staying portion which has a bad effect on purge efficiency, an analyzer having an ion source with a complex structure and/or an analyzing column and detection unit, and a shutoff valve or a switching valve having many resin parts which hinder rapid purge by absorbing a gas, or the like. Therefore, when gas substitution in. a gas system is carried out, these parts determine rate control of the substitution of the entire gas system. As effecting purge methods in gas systems, a batch purge which fluctuates pressure from high pressure (˜10 Mpa) to vacuum state (below 1 torr) to create a state of stopping the gas flow, or a flow purge with a high flow rate (litter/min) have been known.
However, these purge methods using high pressure or the load of a high volume of gasoline to flow rate when applied to the machinery or parts constitution a gas system become a cause of breakage or failure of parts and the like, such that there are many cases where the purge methods cannot be utilized. Therefore, since sometimes a measure to increase the flow rate to about several litters is necessarily taken, it takes a very long time in the gas substitution. In particular, when a high-purity gas whose impurity concentration is below parts per billion (hereinafter ppb) level is supplied, there is a need to carry out gas substitution sufficiently.
SUMMARY OF THE INVENTION
Therefore, the object of the present invention is to provide a gas supplying apparatus and a gas substitution method which does not damage the machinery and parts constituting the gas system, and which is capable of carrying out gas substitution in the gas system in a short time with good efficiency.
To achieve the above-mentioned object of the present invention, there is provided a gas supplying apparatus for switching and supplying plural kinds of gas, the apparatus comprising: a gas supplying passage; a gas exhaust passage connected to the gas supplying passage; a back pressure regulator provided in the gas supplying passage or the gas exhaust passage; a flow rate regulator provided in the gas supplying passage or the gas exhaust passage; and a control means for operating the back pressure regulator and the flow rate regulator with a predetermined sequence.
Furthermore, according to the present invention, there is provided a gas substitution method for substituting a gas after switching into a gas supplying passage by switching the kind of gases to be supplied, the method comprising the steps of: carrying out an operation for fluctuating pressure in the gas supplying passage within a range of pressure limitation of component parts thereof until a concentration of a gas before switching remaining in the gas supplying passage becomes ppb level when the gas after switching is made to flow in the gas supplying passage; setting the pressure to a predetermined pressure; and carrying out an operation for increasing flow rate of the gas after switching in the gas supplying passage under a flow rate limitation of the component parts thereof until the concentration of the gas before switching remaining in the gas supplying passage becomes sub-ppb level.
Furthermore, the method further comprises the steps of: providing a gas exhaust passage connected to the gas supplying passage; providing a back pressure regulator in the gas supplying passage or the gas exhaust passage; and providing a flow rate regulator in the gas supplying passage or the gas exhaust passage connected to the gas supplying passage; wherein the operation for fluctuating the pressure in the gas supplying passage is carried out by the back pressure regulator; and the operation for increasing the flow rate of a gas is carried out by the flow rate regulator.
BRIEF DESCRIPTION OF THE INVENTION
FIG. 1 is a systematic view showing an embodiment of a gas supplying apparatus according to the present invention;
FIG. 2 is a graph showing a concentration change of nitrogen for a conventional flowing purge and a pressure fluctuating purge;
FIG. 3 is a graph showing a concentration change of nitrogen for a conventional flowing purge and a flow rate increasing purge; and
FIG. 4 is a graph showing a concentration change of nitrogen for a conventional flowing purge and a pressure fluctuating purge+a flow rate increasing purge.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 is a systematic view showing an embodiment of gas supplying apparatus according to the present invention. The gas supplying apparatus is for switching and supplying two kinds of gases, particularly gases having a high degree of purity whose impurity concentration is below ppb level, to an analyzer 10 . The gas supplying apparatus is provided with a switching value 15 (4-way valve) for switching a passage for the gases supplied from two gas sources 11 , 12 into an analyzing passage 13 directed to the analyzer 10 and into a purge passage 14 , a flow rate regulator 16 for regulating gas amount flowing along the analyzing passage 13 , a flow rate regulator 18 for exhaust gas for regulating the amount of the exhaust gas flowing along an exhaust passage 17 of the analyzer 10 , a back pressure regulator 20 provided in a discharge passage 19 branched from the analyzing passage 13 for regulating a pressure in the gas system, and a control means 21 for controlling the machinery or regulators 15 , 16 , 18 , 20 .
In the present invention, either the flow rate regulator 16 or the flow rate regulator 18 may be provided alone. The flow rate regulators are preferably provided only in the exhaust passage 17 in a microanalysis analyzer like APIMS, considering that the flow rate regulators become contaminating sources. Furthermore, when the flow rate regulator 16 is provided in the analyzing passage 13 , it is preferred to select a flow rate regulator having an excellent purge performance, Moreover, when the flow regulator 15 is provided in the analyzing passage 13 , the back pressure regulator 20 can be provided in the exhaust passage 17 without providing the discharge passage
In the gas supplying apparatus, thus formed, the gas substitution after switching the switching valve 15 is carried out as follows. In this regard, the present invention will be explained by assuming a pressure of the gases supplied from the gas sources 11 , 12 commonly of 0.3 Mpa (absolute pressure, same hereinafter), a set value of the back, pressure regulator 19 during common analysis of 0.13 Mpa, a set value of the flow rate regulator 16 of 2 litter/min, a set value of the flow rate regulator 15 of 1.5 litter/min.
By switching the switching valve 15 , a gas(e.g., nitrogen) from the gas source 11 is switched to a gas(e.g., hydrogen) from the gas source 12 . Then, an operation for fluctuating the set value of the back pressure regulator 20 between a low pressure and a high pressure respectively is carried out. For example, the operation for fluctuating the pressure of 0.1 Mpa and 0.3 Mpa is carried out keeping a state where gas flows through the flow rate regulators 16 , 18 fixed to the above respective set values. In the pressure fluctuating operation, the machinery or parts are not damaged since pressure is set to values of maximum pressure and minimum pressure within a range of pressure limitation.
Furthermore, the set value of pressure may be switched right after pressure in the gas system reaches the set pressure, however, the set value of pressure may also be switched after appropriate time passes, for example, after respectively maintaining pressure at 0.1 Mpa for 5 seconds and at 0.3 Mpa for 3 seconds. The number of times for repeating the pressure fluctuating operation is preferably set according to the conditions, such as volume or length of the entire gas system, range of pressure fluctuation, or the like, however, it is sufficient to carry out about 5˜6 times for about 1˜2 minutes for a gas system during common analysis. It is possible to decrease the residual concentration of nitrogen supplied in advance down to ppb level swiftly by carrying out the above pressure fluctuating operation.
After a predetermined pressure fluctuating operation comes to an end, the set value of the back pressure regulator 20 is restored to 0.13 MPa which is the standard value. Then, an operation for increasing the set values of flow rates of the flow rate regulators 16 , 18 , is carried out. For example, the operation for increasing the set value of the flow rate regulator 16 to 4 litter/min and the set value of the flow regulator 18 to 3.5 litter/min and maintaining the values for a predetermined time is carried out. In this flow rate increasing operation, there is no case where machinery or parts receive damage due to a large volume of gas flowing at a gas flow rate set at a value of the gas flow rate below its flow rate limitation. A time for the flow rate increasing operation is, similar to the above, preferably set according to the conditions, such as a volume or a length of the entire gas system, the set value of the flow rate, or the like, however, it is sufficient to carry out about 3˜6 minutes for a gas system doing common analysis.
As described above, it is possible to decrease a nitrogen concentration which has been decreased to ppb level in the pressure fluctuating operation, to sub-ppb level in the flow rate increasing operation, by carrying out the pressure fluctuating operation flowed by the flow rate increasing operation. The above purge operations may be carried out by hand-operating the flow regulators 16 , 18 or the back pressure regulator 20 , including operation of the switching valve 15 , however, a series of operations are automatically carried out by the control means 21 , having a predetermined purge sequence.
That is to day, it is possible to carry out an operation of switching the gas to be supplied up by substituting the gas in the gas system completely automatically, by inputting the set values of the high pressure and the low pressure of the back pressure regulator 20 , the maintaining time after reaching the set pressures, the continuation time of the pressure fluctuating operation, the set values of flow rate increase of the flow rate regulators 16 , 18 , the continuation time of the flow rate increasing operation, or the like, to the control means 21 provided with a sequencer and a programmer with the optimum conditions according to the apparatus constitution in advance.
Furthermore, it is also possible to decrease the nitrogen concentration using only either with the above pressure fluctuating operation(the pressure fluctuating purge) or with the flow rate increasing operation(the flow rate increasing purge), however, it takes a long time to decrease down to the sub-ppb level. Furthermore, it may be considered to carry out the flow rate increasing operation in advance, however, in view of the both purge characteristics, the more effective purge (the gas substitution) may be carried out by first carrying out the pressure fluctuating operation capable of purging effectively a gas containing impurities of high concentration above ppb level staying in a dead space in the gas system and then, carrying out the flow rate increasing operation capable of purging effectively the impurities adsorbed in the gas system. That is to say, if the pressure fluctuating operation is carried out after the flow rate increasing operation, there occurs a case where impurities purged from the dead space by the pressure fluctuating operation flow in the gas system purged by the flow rate increasing operation and impurities are adsorbed therein so that it is impossible to make the most of the both purge characteristics sufficiently.
Furthermore, the present embodiment shows a basic construction of the gas supplying apparatus, however, the machinery for supplying a gas is not limited to the analyzer and the present invention may be also applied to the apparatus for supplying a gas to various types of semiconductor manufacturing apparatuses. Furthermore, more than three kinds of gases may be switched and supplied by appropriately arranging valves or passages and in this case, it is still possible to carry out the gas substitution effectively.
Embodiment
In a gas supplying apparatus having a construction as shown in FIG. 1, concentration of nitrogen in hydrogen was sequentially measured by an analyzer after a gas to be supplied was switched from nitrogen to hydrogen. First, the concentration change of nitrogen, when hydrogen was supplied with the standard setting where the flow rate is 2 litter/min(the flow rate regulator 16 , same hereinafter) and 1.5 litter/min(the flow rate regulator 18 , same hereinafter) was measured (conventional flowing purge) and the pressure is 0.13 MPa,. Next, it was carried out that the operation for fluctuating the pressure in the gas system between 0.1 MPa(for 5 seconds) and 0.3 MPa (for 3 seconds) with the flow-rate set as indicated. Then, concentration change of nitrogen, when the supply of hydrogen was continued by restoring the pressure to 0.13 MPa, was measured(the pressure fluctuating purge). The measurement results during the conventional flowing purge and during the pressure fluctuating purge are shown in FIG. 2 .
Continuously, the operation for increasing the set value of flow rate to 4 litter/min and 3/5 litter/min was carried out for 4 minutes while maintaining the pressure 0.13 Mpa of the standard setting as indicated. Then, the concentration change of nitrogen, when the supply of hydrogen was continued by restoring the flow rate to 2 littler/min and 1/5 litter/min, was measured(the flow rate increasing purge). The measurement results during the flow rate increasing purge and during the above conventional flowing purge as shown in FIG. 3 .
Furthermore, after the operation for fluctuating the pressure in the gas system between 0.1 MPa(for 5 seconds) and 0.3 MPa(for 3 seconds) was carried out for 1 minute, the operation for increasing the set value of flow rate to 4 litter/min and 3.5 litter/min was carried out for 3 minutes. Then, the concentration change of nitrogen, when the supply of hydrogen was continued by restoring the flow rate to 2 littler/min and 1.5 litter/min, was measured (the pressure fluctuating purge+the flow rate increasing purge). The measurement results during the above pressure fluctuating purge+the flow rate increasing purge and the measurement result during the above conventional flowing purge are shown in FIG. 4 . Moreover, the measurement result after the nitrogen concentration reached 1 ppb, is shown in FIG. 4 .
In the respective measurement results, the time until nitrogen concentration reached 1 ppb was 440 seconds for the conventional flowing purge, 400 seconds for the pressure fluctuating purge, 410 seconds for the flow increasing purge, and 330 seconds for the pressure fluctuating purge+the flow rate increasing purge. Furthermore, as shown in FIG. 4, it was understood that the purge performance(the gas substitution performance) was excellent in the region below 1 ppb(sub-ppb level).
As described above, according to the present invention, it is possible to carry out the gas substitution in the gas system in a short time with a good efficiency and there is no, case where damage occurs to the machinery and parts. | 4y
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This is a continuation of application Ser. No. 509,078, filed June 29, 1983 abandoned.
FIELD OF THE INVENTION
The present invention relates to a retouchable mat film and, more particularly, to a retouchable mat film which has a mat layer on either or both surfaces of a hydrophobic support and wherein letters can be written into or erased from the mat layer(s) or a wash-off relief image formed on said layer(s).
BACKGROUND OF THE INVENTION
Mat films consisting of an inflexible hydrophobic support and an overlying mat layer containing a matting agent such as silicon dioxide, titanium oxide or glass powder are directly used for drawing purposes or coated with a photosensitive emulsion layer to form a wash-off photographic material which is exposed in a selected image area, developed and has the non-image area subsequently washed off.
In order to be used for these purposes, mat films are especially required to have the following features:
(1) They have high tensile strength, tear strength and bending strength, no tendency of curling and are dimensionally stable against changes in temperature and humidity;
(2) letters can be easily written into the mat films in drawing ink or with a pencil and they can be easily erased from the mats;
(3) letters can be rewritten in the retouched area in drawing ink or with a pencil a number of times.
Various approaches to improve erasability of letters from mat films have been considered. For example, Japanese Patent Application (OPI) No. 53067/81 (corresponding to U.S. Pat. No. 4,366,239) (the term "OPI" as used herein refers to a "published unexamined Japanese patent application") discloses that such an improvement is achieved by incorporating poly(methyl methacrylate) and nitrocellulose in the mat layer as binders. Other conventional binders for the mat layer include vinylidene chloride copolymers (see, for example, British Pat. No. 1,047,697 (U.S. Pat. No. 3,370,951)); poly(methyl methacrylate) (see, for example, U.S. Pat. No. 3,353,958); polyesters or polyester amides (see, for example, U.S. Pat. No. 3,627,563); acetyl cellulose (see, for example, Japanese Patent Publication No. 48844/74 (U.S. Pat. No. 3,615,554)); and cellulose esters and polyesters (see, for example, Japanese Patent Publication No. 39414/74). After letters written in drawing ink on the mat layer containing these binders were erased with a rubber eraser, frequently, it was not possible to write lines of the desired fineness in the erased area because it repelled the drawing ink.
SUMMARY OF THE INVENTION
Therefore, the primary object of the present invention is to provide a mat layer that can be retouched in ink at least 10 times.
This object of the present invention can be achieved by a retouchable mat film that incorporates in the mat layer a binder made of a mixture of poly(methyl methacrylate) or a copolymer containing at least 80 wt % of methyl methacrylate and a hydrophilic polymer.
DETAILED DESCRIPTION OF THE INVENTION
Suitable methyl methacrylate copolymers are those copolymerized with vinyl compounds such as methyl acrylate, ethyl acrylate, butyl acrylate, styrene, methyl styrene, chlorostyrene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylic acid, acrylonitrile, glycidyl acrylate, glycidyl methacrylate and hydroxyethyl acrylate.
Illustrative hydrophilic polymers are polymers and copolymers containing at least 5 mol %, preferably at least 10 mol %, of a vinyl compound having a carboxyl group such as acrylic acid or methacrylic acid; cellulose derivatives having a carboxyl group such as cellulose acetyl phthalate and cellulose acetyl hexahydrophthalate; cellulose ether; polymers and copolymers containing at least 10 mol % of a vinyl compound having a hydroxyl group such as vinyl alcohol, hydroxyalkyl (meth)acrylate (e.g., hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate or diethylene glycol mono(meth)acrylate); as well as water-soluble natural polymers such as gelatin and starch. Polymers and copolymers of carboxyl group having vinyl compounds that are miscible with poly(methyl) methacrylate) and derivatives thereof are preferred. (Meth)acrylate means acrylate and methacrylate. Accordingly, for example, hydroxyalkyl (meth)acrylate means hydroxyalkyl acrylate and hydroxyalkyl methacrylate.
More specifically, preferred hydrophilic polymers include, but are by no means limited to, the following:
1. Methyl methacrylate-acrylic acid copolymer (83:17 mol %)
2. Methyl methacrylate-acrylic acid copolymer (88:12 mol %)
3. Methyl methacrylate-itaconic acid copolymer (90:10 mol %)
4. Methyl methacrylate-maleic acid copolymer (92:8 mol %)
5. Styrene-acrylic acid copolymer (85:15 mol %)
6. Methyl methacrylate-methacrylic acid copolymer (88:12 mol %)
7. Methyl methacrylate-methacrylic acid copolymer (85:15 mol %)
8. Ethyl methacrylate-methacrylic acid copolymer (86:14 mol %)
9. Ethyl methacrylate-methacrylic acid copolymer (83:17 mol %)
10. Butyl methacrylate-methacrylic acid copolymer (80:20 mol %)
11. Tert-butyl methacrylate-acrylic acid copolymer (84:16 mol %)
12. Propylmethacrylate-methacrylic acid copolymer (82:18 mol %)
13. Styrene-butyl acrylate-methacrylic acid copolymer (45:40:15 mol %)
14. Styrene-vinyl acetate-methacrylic acid copolymer (40:45:15 mol %)
15. Butyl methacrylate-2-hydroxyethyl methacrylate copolymer (30:70 mol %)
16. Butyl methacrylate-2-hydroxyethyl acrylate copolymer (40:60 mol %)
17. Butyl methacrylate-2-hydroxypropyl methacrylate copolymer (35:65 mol %)
18. Butyl methacrylate-diethylene glycol monomethacrylate copolymer (45:55 mol %)
19. Methyl methacrylate-2-hydroxyethyl methacrylate copolymer (42:58 mol %)
20. Methyl methacrylate-methacrylic acid-acrylic acid copolymer (84:8:8 mol %)
21. Methyl methacrylate-methacrylic acid-2-hydroxyethyl methacrylate copolymer (60:10:30 mol %)
22. Cellulose acetyl phthalate
23. Cellulose acetylhexahydrophthalate
24. Methyl cellulose
25. Ethyl cellulose
26. Hydroxyethyl cellulose
27. Hydroxypropyl cellulose
28. Methyl methacrylate-vinyl alcohol copolymer (75:25 mol %)
29. Ethylene-vinyl alcohol copolymer (70:30 mol %)
30. Vinyl acetate-vinyl alcohol copolymer (30:70 mol %)
31. Cyanoethyl cellulose
The mixing ratio of polymethyl methacrylate or methyl methacrylate copolymer to the hydrophilic polymer is preferably such that the hydrophilic polymer content is 80 to 20 wt %, more preferably 70 to 30 wt %, of the total binder.
Preferred binder mixtures for use in the present invention include a mixture of poly(methyl methacrylate) and a hydrophilic polymer, more specifically, a mixture of poly(methyl methacrylate) and a methacrylic acid copolymer.
A suitable matting agent for use in the present invention is silicon dioxide which may be used in combination with titanium oxide, zinc oxide, starch or barium sulfate. Preferred silicon dioxide is "crystalline silica" and is commercially available from Tatsumori K.K., Japan under the trade name of Crystalite-FM-1 or -VXR. There is no particular limitation to the particle size of the matting agent, but the preferred average size is from 0.5 to 10μ, and a 1 to 5μ range is particularly preferred.
Suitable hydrophobic supports for use in the present invention include polyester films such as polyethylene terephthalate and polyethylene naphthalate films; cellulose ester films such as cellulose acetate and cellulose acetate butyrate films; and polycarbonate films. Dimensionally stable polyester films, especially polyethylene terephthalate films, are used with particular advantage.
The hydrophobic support is coated with a mat layer formed from a dispersion of the binder and the matting agent in a suitable solvent that is prepared by agitation with an attritor, sand grinder, homomixer or a ball mill. Suitable solvents include ketones such as acetone, methyl ethyl ketone and cyclohexanone; esters such as ethyl acetate, propyl acetate and butyl acetate; ethers such as dioxane and tetrahydrofuran; alcohols such as methanol, ethanol, propanol, butanol and diacetone alcohol; chlorides such as methylene chloride, ethylene chloride and propylene chloride; phenols such as phenol, cresol and resorcin; methyl cellosolve, ethyl cellosolve, methyl cellosolve acetate and dimethylformamide. These solvents may be used either alone or in combination.
The mat layer may contain a coating aid, a cross-linking agent or a whitening agent without any resulting disadvantage. A preferred whitening agent is titanium oxide having a particle size of 0.1 to 0.5μ. The coating weight of titanium oxide is preferably from 0.03 to 3 g/m 2 , more preferably from 0.05 to 2 g/m 2 .
The mat layer may be formed on the support either directly or through a subbing layer. The subbing layer may be formed from a coating solution of a binder or binders in an organic solvent such as methanol, acetone or methyl ethyl ketone. Suitable binders are cellulose esters such as nitrocellulose and cellulose diacetate; polyesters; or styrene-butadiene copolymers or vinylidene chloride copolymers. The subbing layer may optionally contain a swelling agent for a polyester film such as cresol, p-chlorophenol or resorcin.
The mat layer may be applied directly to the hydrophobic support or to a subbing layer which is coated on the hydrophobic support by any conventional technique such as gravure coating, extrusion coating, dip coating, bar coating or roller-bead coating. The drying temperature preferably ranges from 50° to 140° C., and the drying period preferably ranges from 30 seconds to 10 minutes. The coating weight of the matting agent preferably ranges from 1 to 20 g, more preferably from 3 to 10 g, per square meter. The coating weight of poly(methyl methacrylate) preferably ranges from 1 to 10 g, more preferably from 2 to 5 g, per square meter. The coating weight of the hydrophilic polymer preferably ranges from 0.1 to 8 g, more preferably from 1 to 5 g, per square meter.
The mat film of the present invention can also be used as the support of a wash-off photographic material. The image area (i.e., exposed area) of the photosensitive emulsion layer of the wash-off material hardens upon development whereas the non-image area (unexposed area) remains unhardened. After the development, the non-image area is washed off under flowing water to provide the image area in relief. Therefore, the greatest feature of the wash-off photographic material is that it is developed with a tanning developing agent that hardens only the exposed area. The tanning developing agent may be incorporated either in the photographic material or in the processing solution.
Illustrative tanning developing agents are catechol, 4-phenyl catechol, hydroquinone, pyrogallol, dihydroxybiphenyl and polyhydroxyspirobisindane. For more examples, see U.S. Pat. Nos. 2,592,368, 2,685,510, 3,143,414, 2,751,295 and 3,440,049. If these tanning developing agents are incorporated within the photographic material, their amount preferably ranges from 0.005 to 1 mol, more preferably from 0.01 to 0.3 mol, per mol of the silver halide in the emulsion layer. The developing agents may be added not only to the emulsion layer but also to the adjacent layer.
The tanning developing agents may be incorporated in the photographic material by various methods. One example is to neutralize alkali solutions of these agents as taught in U.S. Pat. No. 3,440,049. Another example is to disperse the agents in water-soluble organic solvents such as cyclohexanone, acetone, methoxyethanol, ethoxyethanol, ethylene glycol, dioxane and dimethylformamide. In still another method, the agents are dispersed in high-boiling point organic solvents for coupler dispersion such as butyl phthalate, dinonyl phthalate, butyl benzoate, diethylhexyl sebacate, butyl stearate, dinonyl maleate, tributyl citrate, tricresyl phosphate, dioctylbutyl phosphate, trihexyl phosphate and trioctadecyl phosphate (see U.S. Pat. No. 3,676,137) or diethyl succinate, dioctyl adipate or 3-ethylbiphenyl. A surfactant may be used to help disperse the solutions of the tanning developing agents in these solvents in hydrophilic protective colloidal solutions, and suitable surfactants are saponin, sodium alkylsulfosuccinate and sodium alkylbenzenesulfonate.
The wash-off photographic material according to the present invention comprises the mat film of the present invention that is coated with a silver halide emulsion layer as the photosensitive emulsion layer. If necessary, the material may also contain an antihalation layer or a surface protective layer. Suitable silver halides are silver chloride, silver chlorobromide, silver bromide, silver iodobromide and silver iodochlorobromide.
Suitable hydrophilic protective colloids are gelatin, carboxymethyl cellulose, polyvinyl alcohol and polyvinyl pyrrolidone. Gelatin is particularly preferred, and suitable gelatins are lime-treated gelatin, acid-treated gelatin and enzyme-treated gelatin, as well as gelatin derivatives.
The silver halide emulsion layer may also contain an anti-foggant, a polymer latex, a surfactant, a chemical sensitizer, a spectral sensitizing dye, etc. For details of these additives, see Research Disclosure, 176, pp. 22-29, December, 1978.
The surface protective layer may contain not only the hydrophilic protective colloid but also a mating agent, a surfactant, a polymer latex, colloidal silica, etc.
The wash-off photographic material according to the present invention preferably has an antihalation layer between the support (i.e., mat film) and the photosensitive emulsion layer. The antihalation layer may contain not only the hydrophilic protective colloid but also a light-absorbing material such as carbon black, colloidal silver, or any of the dyes that are listed in Research Disclosure, supra. Carbon black or colloidal silver are particularly preferred. For facilitating coating with a hydrophilic colloidal layer such as the silver halide emulsion layer or antihalation layer, the mat layer may be subbed with a layer that is primarily made of gelatin.
The wash-off material according to the present invention may be developed with any known technique. If the tanning developing agent is incorporated in the wash-off material, it may be processed in an activator bath. The basic composition of the activator bath is the same as the conventional black-and-white developing solution except for no developing agent; it may optionally contain a pH buffer, an anti-foggant, a development accelerator and a water softener.
The present invention is described in greater detail by reference to the following examples which are given here for illustrative purposes only and are by no means intended to limit the scope of the invention.
EXAMPLE 1
A biaxially oriented crystalline polyethylene terephthalate film was coated with a solution of the following formulation in an amount of 15 g/m 2 , and dried at 120° C. for 10 minutes:
______________________________________ ContentComponents (wt %)______________________________________Nitrocellulose 0.5Metacresol 8.0Acetone 42.0Methanol 49.5______________________________________
Three samples of the so treated film were coated with the following dispersions of matting agent (a), (b) and (c) in an amount of 40 g/m 2 , and dried at 120° C. for 5 minutes to provide three mat films (A), (B) and (C).
______________________________________ ContentComponents (wt %)______________________________________Dispersions of Matting Agent (a)Poly(methyl methacrylate), 10"Sumipex B-LG" (product ofSumitomo Chemical Co., Ltd.)Methyl ethyl ketone 47Acetone 25Diacetone alcohol 10Silicon oxide (av. size = 1.5μ) 7Titanium oxide (av. size = 0.3μ) 1Dispersion of Matting Agent (b)Poly(methyl methacrylate), 8"Sumipex B-LG" (product ofSumitomo Chemical Co., Ltd.)Nitrocellulose, RS 1/2 of 3Daicel Chemical Industries, Ltd.Methyl ethyl ketone 46Acetone 25Diacetone alcohol 10Silicon oxide (av. size = 1.5μ) 7Titanium oxide (av. size = 0.3μ) 1Dispersion of Matting Agent (c)Poly(methyl methacrylate), 6"Sumipex B-LG" of SumitomoChemical Co., Ltd.Nitrocellulose, RS 1/2 of 2.5Daicel Chemical Industries, Ltd.Methacrylic acid-methyl 3.0methacrylate copolymer (MAA toMMA molar ratio = 2:8,m. wt. = ca. 10,000-30,000)Methyl ethyl ketone 45.5Acetone 25.0Diacetone alcohol 10.0Silicon oxide (av. size = 1.5μ) 7.0Titanium oxide (av. size = 0.3μ) 1.0______________________________________
Letters were written into the mat surface of each sample in drawing ink, erased with a rubber eraser and the same letters were written on the erased area. On the second trail of retouching, Samples (A) and (B) repelled the applied ink and gave only very thin lines. Sample (C) withstood 10 retouching operations and produced lines of the desired fineness.
EXAMPLE 2
(1) Preparation of a Support
A biaxially oriented crystalline polyethylene terephthalate film 100μ thick was coated with a solution of the following formulation in an amount of 10 g/m 2 and dried at 120° C. for 5 minutes.
______________________________________ ContentComponents (wt %)______________________________________Cellulose acetate 0.4Nitrocellulose 0.4Acetone 50.0Resorcin 6.2Methanol 43.0______________________________________
The so treated film was coated with the following dispersion of matting agent in an amount of 50 g/m 2 and dried at 120° C. for 10 minutes.
______________________________________ ContentComponents (wt %)______________________________________Poly(methyl methacrylate), 7"Sumipex B-LG" of SumitomoChemical Co., Ltd.Nitrocellulose, RS 1/2 of 3Daicel Chemical Industries, Ltd.Methyl methacrylate-methacrylic 4acid (85:15 mol %) copolymerDiacetone alcohol 15Acetone 47.5Methanol 11Silicon oxide (av. size = 1.5μ) 12Titanium oxide (av. size = 0.3μ) 0.5______________________________________
The resulting mat layer was further coated with the following solution in an amount of 10 g/m 2 and dried at 120° C. for 10 minutes.
______________________________________ ContentComponents (wt %)______________________________________Gelatin 1.0Polyamide epichlorohydrin 0.02resin described in JapanesePatent Publication No. 26580/74Nitrocellulose 0.5Water 2.0Acetic acid 2.0Methanol 63.48Acetone 30.0______________________________________
(2) Preparation of a Wash-Off Photographic Material
An emulsion containing 60 g of gelatin and 1.1 mols of silver chlorobromide (silver bromide content: 30 mol %) in 760 g of water was prepared. The silver chlorobromide grains had an average size of 0.4 micron. After removing soluble salts by a conventional method, the emulsion was chemically sensitized with sodium thiosulfate. To the so sensitized emulsion, the following composition was added.
______________________________________ ContentComponents (g)______________________________________6% Aqueous saponin 20Dispersion (a) 500______________________________________
Dispersion (a) was prepared by vigorously agitating a mixture of the following compositions (a-1) and (a-2).
______________________________________ ContentComponents of (a-1) (g)______________________________________ ##STR1## 17 ##STR2## 3 ##STR3## 7Tricresyl Phosphate 18Ethyl Acetate 25______________________________________ ContentComponents of (a-2) (g)______________________________________Gelatin 25Water 3806% Aqueous saponin 25______________________________________
A composition for antihalation layer was prepared from the following formulation.
______________________________________Components Content______________________________________Gelatin 40 gCarbon black 15 gWater 1,000 ml______________________________________
The photographic support prepared in (1) was coated with the composition for antihalation layer to give a carbon black coating weight of 0.1 g/m 2 . The resulting antihalation layer was overlaid with the silver halide emulsion, thereby forming a wash-off material. The material was exposed through an optical wedge for 5 seconds and developed in an activator bath of the following composition at 20° C. for 10 seconds. The developed material was then immersed in warm water (40° C.) wherein the unhardened area was wiped off with a sponge and thereafter the material was dried.
______________________________________Components of the Activator Bath Content______________________________________Potassium carbonate 25 gPotassium hydroxide 7 gPotassium sulfite 1 gPotassium bromide 0.1 gWater to make 1,000 ml______________________________________
The mat surface of the non-image area in relief was subjected to 10 retouching operations with drawing ink; no ink repellency occurred and lines of the desired thickness were produced.
While the invention has been described in detail and with reference to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a portable electronic display unit for receiving and storing data from any selected computer, and for displaying stored data on command but without the user's possibility of changing the stored data in any way.
The present display unit is a retrieval and display-only device for electronic image data that has already been stored elsewhere, such as in any of central database, single computer or another unit that might be present in an office or school. As such, it answers the need for a simplified, portable, display only device capable of accessing data from multiple sources without the complexities attendant to a personal computer designed for many functions besides reading data from other computers. Multiple units in one environment increase the ease of information dissemination.
2. Prior Art
Electronic books are disclosed in the following U.S. patents: Rubincam U.S. Pat. No. 4,159,417 and Gaston U.S. Pat. No. 5,956,048. In Rubincam the digitally encoded contents of a book are stored in a memory which is removably insertable into the housing of the electronic book. In Gaston the electronic book is plugged into a mated downloading stand from which the encoded contents of a book are downloaded into the electronic book.
Yianilos U.S. Pat. No. 5,153,831 discloses a device having a display screen, an electronic memory with compressed text, and a keyboard for formulating words that are to be searched in that text for display on the screen along with adjoining words as they occur in the text. Borssuk U.S. Pat. No. 5,475,399 discloses a relatively thick, box-like device with a display screen, various keys for controlling the screen display, including keys to change the font size, and an insert port for receiving a memory, such as an EPROM, microfloppy or CD ROM.
BRIEF SUMMARY OF THE INVENTION
The present display unit is designed for the input of data stored in any computer, whether the user's or anyone else's to which the user has authorized access, for read-only display by the user at his or her convenience. In a large office it reduces paperwork by providing a convenient, paper-less way for a worker to access and read the contents of files from a central data base or network.
Preferably, the present display unit is a thin, flat device of substantially the same size as a standard letter-size sheet of paper, so the user's experience with this device approaches the familiar “look-and-feel” of actually reading paper documents.
A principal object of the present invention is to provide a novel and simplified display unit for enabling the user to conveniently read data stored in its internal memory but with no possibility of altering that data in any way. The user has mobile access to files, and information without carrying “paper files.”
Further objects and advantages of this invention will be apparent from the following detailed description of a presently preferred embodiment thereof, shown in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the present display unit, taken from in front of the screen;
FIG. 2 is an exploded perspective view of the display unit, taken from in front of the screen, with the base and cover of its housing separated to show internal components;
FIG. 3 is a view similar to FIG. 2, but taken from behind the screen; and
FIG. 4 is a flow diagram showing the operation of the present display device
FIG. 5 is a perspective view of a unit as the screen for a laptop computer.
DETAILED DESCRIPTION OF THE INVENTION
Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the particular arrangement shown since the invention is capable of other embodiments.
Referring first to FIG. 1, viewed from the outside the present display unit has a thin, flat, letter-size housing or casing made up of a rectangular base 10 and a similar front or top cover 11 detachably connected to the base in any suitable fashion and covering it when the display unit is in use.
The cover 11 presents a flat LCD (liquid crystal display) panel or screen 14 of substantially rectangular outline. For supporting the screen 14 the cover has a rectangular frame with opposite, narrow, flat side walls 15 and 16 , a narrow, flat top wall 17 , and a narrow, flat bottom wall 18 , and a border for the screen 14 with narrow, flat front segments 15 b , 16 b , 17 b , and 18 b which extend in from the correspondingly numbered side, bottom and top walls of the frame. Preferably, the frame is substantially the same size as a standard letter-size sheet of paper, i.e., 8.5 inches wide by 11 inches long, so that the user handling or viewing it receives a mental impression similar to what he or she would get while reading from a standard letter-sized sheet of paper.
The base 10 of the housing has opposite side walls 115 and 116 , a top wall 117 , and a bottom wall 118 which merge smoothly with the correspondingly numbered (minus 100) walls of the cover when it is closed, as shown in FIG. 1 .
On the left front segment 15 of the cover near the top are LED's 20 , 21 , 22 and 23 for indicating various functions associated with the display unit, such as “power,” “battery,” “memory,” and “test.” On the right front segment 16 b of the cover are manually operable push-buttons 24 , 25 , 26 , 27 and 28 for initiating various commands to the electronic circuitry that determine what appears on the screen 14 , such as “file,” “document,” “next,” “back,” and “system.” Also on the right front segment 16 b near the top is located a mouse-like scroll bar 29 which the user may slide up and down to quickly locate a document, file or particular line of text displayed on the screen 14 .
Referring to FIGS. 2 and 3, the base 10 supports on the inside of the housing the following electronic components of the present display unit: a microprocessor 30 , memory chips, 31 , a battery pack 32 , and a microprocessor 34 . A data input port 35 of known design (FIG. 2) is located in the bottom wall 118 of the base. A flexible multi-conductor cable 37 connects the output of microprocessor 30 to the LCD screen 14 . The microprocessors 30 and 34 , memory chips 31 , and various other components of the display unit's electronic circuitry are on a circuit board 38 located on the inside of base 10 .
On the back or inner side of the cover 11 a circuit board 40 carries a backup battery 41 for the RAM, a co-processor 42 , chips 43 for sound and infra-red functions, and various other electronic components. A backup power input terminal 44 (FIG. 3) is located in the top wall 17 of the cover.
In the use of this device, the user can take it to the location of any computer whose data the user wants to access at his or her convenience. This can be the user's own desktop computer or portable computer, or a computer to which the user has authorized access, or a central network or another electronic image display unit. The user by a well known technique downloads data from that computer into the user's portable display unit via the input port 35 . That data now is available for display on the screen 14 any time the user chooses to do so. Thus, an abundance of information is readily and conveniently available to the user without the exchange of any paper documents. Since the present display unit is limited to read-only operation, there is no possibility for the user to alter or corrupt the downloaded data in any way.
The flow chart of FIG. 4 is self-explanatory and does not require extensive reiteration. Depressing FILES displays all files loaded into memory; depressing DOC. displays all documents in a selected file; depressing NEXT advances to next document in file; depressing BACK returns to previous document in file.
FIG. 5 shows the unit as a removable screen for a laptop computer. The unit functions as normal after removal. | 4y
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FIELD OF THE INVENTION
The present invention relates generally to the field of wireless Local Area Network (LAN) communications, and in particular to establishment and coordination of mobile terminal sleep phases within the LAN.
BACKGROUND OF THE INVENTION
A new forthcoming standard for wireless LAN services having high throughput, ETSI HIPERLAN Type 2, promises to open new opportunities for both existing applications and new applications. Current versions and approved portions of the proposed ETSI HIPERLAN Type 2 standard are hereby incorporated by reference. HIPERLAN Type 2 LAN networks use a Time Division Duplex (TDD) airlink, meaning that an Access Point (AP) and a Mobile Terminal (MT) in the LAN network both use the same radio frequency to communicate with each other. The AP is connected to a Network (NW) such as an operator's intranet, and the MT will in most cases be a wireless Network Interface Card (NIC) to a personal computer (PC).
FIG. 1 shows an example configuration for an exemplary HIPERLAN Type 2 system, including an AP 104 within a cell 102 . MTs 106 , 108 and 110 are also located within the cell 102 . As shown in FIG. 1, the AP 104 can communicate via a wireless TDD airlink 112 with, for example, the MT 110 . Within each cell, an AP for that cell selects the best frequency with which to communicate with one or more MTs within the cell. The AP's frequency selection can be based on, for example, the AP's measurements of interference at other frequencies, as well on measurements made by MTs within the cell.
In accordance with the proposed HIPERLAN Type 2 wireless LAN standard, a wireless LAN system includes a Medium Access Control (MAC) layer, which is implemented as a reservation-based MAC layer. FIG. 2 shows an exemplary MAC data frame 200 having an exemplary MAC frame structure, including a Broadcast Control Channel (BCCH) 202 , a Frame Control Channel (FCCH) 204 , a Downlink Channel (DLCHAN) 206 , an Uplink Channel (ULCHAN) 208 , and a Random Access Channel (RACH) 210 . As shown in FIG. 2, the boundary between the DLCHAN 206 and the ULCHAN 208 , as well as the boundary between the ULCHAN 208 and the RACH 210 , can be changed in accordance with traffic requirements. Assuming that the MT 110 has been authenticated and a connection has been established between the MT 110 and the AP 104 , then in order to send Uplink (UL) data via the AP 104 , the MT 110 monitors the BCCH 202 and the FCCH 204 for the occurrence of random access opportunities. The MT 110 can then request uplink resources via the RACH 210 , and the AP 104 will acknowledge the request for uplink resources and start scheduling UL resources in the TDD airlink 112 for use by the MT 110 . In other words, when the MT 110 places a request for uplink resources, a reservation-based access starts.
When the AP 104 receives Downlink (DL) data from the network (NW) for the MT 110 , the AP 104 either buffers the data and defers transmission of the data to the MT 110 if the MT 110 is sleeping, or transmits the DL data to the MT 110 at the next possible occasion. The AP 104 announces that it has data for the MT 110 (and/or other MT's within the cell 102 ) by broadcasting a frame having the format of the frame 200 , with a MAC-ID and a Data Link Control Channel ID (DLCC-ID) of the MT 110 in the FCCH 204 following the BCCH 202 . In this situation, the FCCH 204 also contains the exact location of the data for the MT 110 , in the DLCHAN 206 of the frame 200 . An MT having a MAC-ID can have several DLCC-IDs.
Since MTs are often powered by finite sources such as batteries, the HIPERLAN Type 2 standard provides for a sleep mode for the MTs to conserve energy usage by the MTs. This sleep mode is outlined in FIG. 3 . As shown in FIG. 3, at a first step 302 , an MT sends a sleep request signal, which can include a suggestion by the MT as to how long the sleep interval should be, or in other words, the sleep duration, to an AP. The AP accepts the sleep request signal, decides the starting time and the sleep duration, and then in step 304 sends a sleep reservation signal to the MT indicating the starting time at which the MT should enter the sleep mode, and the sleep duration or time the MT should remain asleep before “waking” to monitor the BCCH of a MAC frame from AP for the occurrence of DL data pending for the MT. The sleep duration can be, for example, an arbitrary number of MAC frames. At step 306 the MT enters the sleep mode, and then when the sleep duration expires at step 308 , the MT awakens and monitors the BCCH for indications of DL data pending for the MT. If DL data is pending, the AP will notify the MT via the BCCH and schedule downloading of the DL data to the MT.
In particular, if the MT discerns that the BCCH contains a signal such as a pending data indicator, indicating that downlink data is pending at the AP for an as-yet undetermined MT, then the MT will analyze the content of a Slow Broadcast Channel (SBCH) in the MAC frame for a dedicated wakeup PDU directed to the MT. The SBCH location in the MAC frame is given by an Information Element (IE) in the FCCH. In other words, the MT will check further to determine whether it is the MT (or one of the MTs) for which data is pending. If no downlink data is pending for any MT, then the MT returns to the sleep mode for another sleep duration time period, at the end of which it will awaken and repeat the cycle by monitoring the BCCH for a pending data indicator, etc. If no pending data indicator is present, or if the indicator indicates that no downlink data is pending, then the MT will go back to sleep.
FIG. 4 shows the case where an MT analyzes the SBCH in the MAC frame for a dedicated wakeup PDU. As shown in FIG. 4, when an MT sleep time expires at time 420 , the MT first examines the BCCH 410 to determine whether the BCCH 410 contains a pending data indicator indicating that the MAC frame 406 contains data for an MT. The pending data indicator does not indicate which MT that the data, if present, is intended for. If a pending data indicator in the BCCH 410 does indicate that the MAC frame 406 contains data for an as yet unspecified MT, then the MT seeks to determine whether the MAC frame 406 contains data for it. It does so by analyzing the FCCH 412 for an indication as to where the SBCH 418 begins in the MAC frame. For example, the FCCH 412 can contain a predefined Information Element (IE) 414 that indicates where the SBCH 418 begins. For example, the predefined IE 414 can be defined to include a MAC-Identification (MAC-ID)=0 and a Downlink Control Channel Identification (DLCC-ID)=0.
The SBCH is located in the DLCHAN of the MAC frame 406 . A DLCHAN can contain, or host, several logical channels, including the SBCH. These channels can include, for example, a User Data Channel (UDC), a DLC Control Channel (DLCH), where DLC stands for “Data Link Control”, a Dedicated Control Channel (DCCH), an In-Band Channel (IBCH), and the Slow Broadcast Channel (SBCH) mentioned above.
The MT then analyzes the SBCH 418 to determine if the SBCH 418 contains any wake-up PDUs that include the MT's MAC-ID. If yes, then the MT knows that downlink data is pending for it, and the MT will stay active to receive the downlink data. If no, then the MT knows that no downlink data is pending for it, and it returns to the sleep mode automatically without announcement to the AP.
In a case where the MT has pending uplink data for transfer to the AP, then the MT can cut short its sleep duration timer or time period and request uplink resources from the AP by, for example, sending an uplink resource request signal on the RACH 210 of a MAC frame 200 .
In Mobitex and pACT (Personal Air Communications System) systems, mobiles must know the concept of different sleep phases, which is not the case for HIPERLAN Type 2.
However, the methods described above suffer several drawbacks. For example, when the MT fails to properly decode the BCCH, FCCH and SBCH upon scheduled wakeup, the behavior of the MT and the AP is unknown. If the MT is presumed to go back to sleep when it fails to decode the BCCH, FCCH or SBCH, then the AP cannot discern whether the MT successfully decoded the wakeup information (for example a wakeup announcement) sent from the AP to wakeup the MT, or whether the AP failed to properly decode or perceive an acknowledgment from the MT (in situations where, for example, the wakeup information instructs the MT to send an acknowledgment signal such as a predetermined signal back to the AP on a reserved uplink channel in the MAC frame that is identified in the wakeup information, or via the next available RACH). The wakeup information can be, for example, in a first case, a wakeup Information Element (IE) located in the FCCH, or in a second case, a wakeup Packet Data Unit (PDU) located in the SBCH.
The AP also cannot discern a situation where the MT failed to properly decode the BCCH, FCCH, or SBCH. In other words, the AP cannot definitively discern the status of the MT. Furthermore, since in the situation where the MT fails to properly decode the BCCH, FCCH or SBCH, the MT is presumed to go back to sleep, the AP must wait until the MT again wakes up before again attempting to establish communication with the MT.
In particular, if the AP sent a wakeup announcement to an MT and the MT failed to properly decode the BCCH, FCCH or SBCH and thus missed a wakeup IE or PDU intended for the MT, (where a MAC-ID in the wakeup IE or PDU that matches the MAC-ID of the MT indicates that the wakeup IE or PDU is intended for the MT), the AP may presume that the MT successfully received the wakeup announcement and is prepared to receive downlink data. Then, the AP will start transmitting downlink data that is pending for the MT. If the MT is not active but instead went back to sleep after missing the wakeup announcement, the retransmission timers in the AP may time out before the MT again awakens to check for pending downlink data, which can cause the AP to remove the MT from a list of MTs that it knows are present in its cell.
Furthermore, if an MT is required to send a new sleep request signal to the AP upon a failure to decode the BCCH, FCCH, or SBCH, the sleep request signal can collide with other data traffic in the MAC frame and lead to unpredicted delays and cumbersome situations for the AP to untangle and resolve. If transmission for all of the MTs to whom a wakeup announcement was transmitted is deferred until the AP can determine that all MTs intending to transmit sleep request signals have done so, then data transmission between the AP and one or more of the MTs can be undesirably delayed.
SUMMARY OF THE INVENTION
In accordance with an exemplary embodiment of the invention, where a type of a wakeup announcement to an MT can indicate whether the MT is required to acknowledge the wakeup announcement, when the MT fails to decode a BCCH, FCCH or SBCH that may contain a wakeup announcement for the MT, the MT decodes subsequent MAC frames to look for the presence of a new wakeup announcement for the MT from the AP.
In accordance with another embodiment of the invention, depending on an amount of traffic present and on algorithms implemented in a scheduler and a sleep announcement entity in the AP, a second wakeup announcement directed to an MT can be included in a next MAC frame following a MAC frame that contained a first wakeup announcement for the MT. As traffic increases, a probability that the second wakeup announcement will be included in a MAC frame subsequent to the next MAC frame following the MAC frame that contained the first wakeup announcement, also increases.
In accordance with another embodiment of the invention, after unsuccessfully decoding a BCCH, FCCH or SBCH that may contain a wakeup announcement for the MT, the MT shall continue to monitor subsequent MAC frames for the occurrence of a wakeup announcement for the MT, until either a predetermined number (N frames ) of MAC frames have transpired, or the MT successfully receives a wakeup announcement. When the MT successfully receives a wakeup announcement, it will remain awake.
In accordance with another embodiment of the invention, when the AP sends a wakeup announcement to an MT indicating that downlink data is pending for the MT, the AP shall proceed as if the MT were active, or in other words, awake. Depending on whether the AP is polling the MT prior to sending data (by, for example, sending a wakeup announcement indicating that the MT should send an acknowledge signal back to the MT), the AP shall retransmit the polling request a configurable number of times, for example until a predetermined number of MAC frames have transpired.
If no polling is used, then the AP shall continue to transmit or retransmit data a configurable number of times until, for example, a predetermined number (N frames ) of MAC frames have transpired. The configurable number can be based on or limited by a maximum allowed number of retransmissions.
In accordance with embodiments of the invention, these features can also variously combined.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of preferred embodiments, when read in conjunction with the accompanying drawings. Like elements in the drawings have been designated by like reference numerals.
FIG. 1 shows an exemplary cell structure in accordance with the HIPERLAN Type 2 standard.
FIG. 2 shows an exemplary MAC frame in accordance with the HIPERLAN Type 2 standard.
FIG. 3 shows an exemplary sleep negotiation dialog between an MT and an AP in accordance with the HIPERLAN Type 2 standard.
FIG. 4 shows an exemplary MAC frame that can contain wakeup PDUs located in an SBCH of the MAC frame.
FIG. 5 shows an exemplary MAC frame in accordance with an exemplary embodiment of the invention.
FIG. 6 shows a flow chart of a process in accordance with exemplary embodiments of the invention.
FIG. 7 shows a flow chart of a process in accordance with exemplary embodiments of the invention.
FIG. 8 shows internal details of an exemplary AP in accordance with exemplary embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Various embodiments of the invention can also be used in situations where the wakeup information includes wakeup IEs that are located in the FCCH, rather than wakeup PDUs that are located in the SBCH. In particular, if the MT discerns that the BCCH contains an indication that DL data is pending at the AP for the MT, then the MT will analyze the content of the FCCH in the MAC frame for an Information Element (IE) or wakeup PDU indicating downlink data is scheduled or pending for the MT.
FIG. 5 shows the case where an MT analyzes the content of the FCCH in the MAC frame for an Information Element (IE) having the MAC-ID of the MT, thus indicating that downlink data is pending for the MT. As shown in FIG. 5, when an MT sleep time expires at time 520 , the MT first examines the BCCH 510 to determine whether the BCCH 510 contains a pending data indicator such as that described with respect to FIG. 4, indicating that the MAC frame 506 contains data for an MT. If a pending data indicator in the BCCH 510 does indicate that the MAC frame 506 contains data for an as yet unspecified MT, then the MT seeks to determine whether the MAC frame 506 contains data for it. It does so by analyzing the FCCH 512 to determine if the FCCH 512 contains a wake-up announcement IE, such as the wakeup IE 514 , that includes the MAC-ID of the MT. If yes, then the MT knows that there is pending downlink data for it, and it will stay active (or in other words, awake) in order to receive the pending downlink data. If no, then the MT knows that there is no pending downlink data for it, and it will re-enter the sleep mode automatically without announcement to the AP.
Since the FCCH will always be present in the MAC frame when data is scheduled in the frame, there is no extra cost incurred when the AP divides sleeping MTs into different groups. For example, to awaken one sleeping MT, one IE in the FCCH bearing the MAC-ID of the MT is necessary, and if two sleeping MTs are to be awakened, then two IEs are required in the FCCH, and so forth. Thus, overhead such as that associated with a preamble of an SBCH is avoided.
Furthermore, the IE or wakeup PDU for a particular sleeping MT can simply be the same IE that would be used to signal the MT if it were awake, or in other words active, since the IE for an active MT will contain both the MAC-ID for the MT and will indicate which downlink channel in the MAC frame the MT can find the downlink data that is scheduled for it to receive.
The IE or wakeup PDU can also be of a type that indicates to the MT that the MT should send a predetermined acknowledge signal back to the AP in an allocated uplink channel within the MAC frame, where the IE identifies the allocated uplink channel that the AP has set aside for the MT. Thus, the IE can be used as a polling request from the AP to the MT. Alternatively, the IE can instruct the MT to send the predetermined acknowledge signal back to the AP via the RACH in the same MAC frame, or in a subsequent MAC frame when the RACH first becomes available. Since the FCCH is located earlier in the MAC frame than the SBCH, locating the IE in the FCCH instead of the SBCH provides the MT with more time to awaken and prepare and send the predetermined acknowledge signal.
The IE or wakeup PDU can also include a null pointer, or in other words a pointer in the IE that is set to a null value, where the null value indicates to the MT that the MAC frame does not contain downlink data for the MT, and the MT should simply remain awake until further notice and decode each BCCH and FCCH that comes along, in order to receive downlink data that will be provided to it in the future. For example, this can provide a scheduler in the AP with a graceful way to handle a new MT in the same MAC frame that the MT wakes up in.
In accordance with a first exemplary embodiment of the invention, where a type of a wakeup announcement to an MT can indicate whether the MT is required to acknowledge the wakeup announcment, when the MT fails to decode a BCCH, FCCH or SBCH that may contain a wakeup announcement for the MT, the MT decodes subsequent MAC frames to look for the presence of a new wakeup announcement for the MT from the AP.
In accordance with a second exemplary embodiment of the invention, depending on an amount of traffic present and on algorithms implemented in a scheduler and a sleep announcement entity in the AP, a second wakeup announcement directed to an MT can be included in a next MAC frame following a MAC frame that contained a first wakeup announcement for the MT. As traffic increases, a probability that the second wakeup announcement will be included in a MAC frame subsequent to the next MAC frame following the MAC frame that contained the first wakeup announcement, also increases.
In accordance with a third exemplary embodiment of the invention, after unsuccessfully decoding a BCCH, FCCH or SBCH that may contain a wakeup announcement for the MT, the MT shall continue to monitor subsequent MAC frames for the occurrence of a wakeup announcement for the MT, until either a predetermined number (N frames ) of MAC frames have transpired, or the MT successfully receives a wakeup announcement. When the MT successfully receives a wakeup announcement, it will remain awake.
In accordance with a fourth exemplary embodiment of the invention, when the AP sends a wakeup announcement to an MT indicating that downlink data is pending for the MT, the AP shall proceed as if the MT were active, or in other words, awake. Depending on whether the AP is polling the MT prior to sending data (by, for example, sending a wakeup announcement indicating that the MT should send an acknowledge signal back to the MT), the AP shall retransmit the polling request a configurable number of times, for example until a predetermined number of MAC frames have transpired.
If no polling is used, then the AP shall continue to transmit or retransmit data a configurable number of times until, for example, a predetermined number (N frames ) of MAC frames have transpired. The configurable number can be based on or limited by a maximum allowed number of retransmissions.
FIG. 6 generally illustrates the principles described above for exemplary embodiments of the invention, from the perspective of an MT. As shown in FIG. 6, after beginning at step 602 , control proceeds to step 604 where an MT that has awakened to monitor a MAC frame, determines that it has failed to properly decode a BCCH, FCCH or SBCH in the MAC frame that could have contained a wakeup announcement for the MT. From step 604 control proceeds to step 606 , where a counter N is set to zero. From step 606 , control proceeds to step 608 where the MT decodes a BCCH and an FCCH in a next MAC frame. From step 608 , control proceeds to step 610 , where the counter N is incremented, and from step 610 control proceeds to step 612 . In step 612 , the MT determines whether the most recent MAC frame contained a wakeup announcement directed to it. If yes, then control proceeds from step 612 to step 614 , where the MT processes the wakeup announcement appropriately, and then control proceeds from step 614 to step 620 where the process ends. If at step 612 the MT determines that the most recent MAC frame did not include a wakeup announcement for the MT, then control flows from step 612 to step 616 , where N is compared with a predetermined value N frames . If N is greater than or equal to the predetermined value N frames , then control proceeds to step 618 , where the MT goes back to sleep. From step 618 control proceeds to step 620 . If at step 616 N is found to be less than the predetermined value N frames , then control returns to step 608 and the cycle repeats.
FIG. 7 generally illustrates the principles described above for exemplary embodiments of the invention, from the perspective of an AP. As shown in FIG. 7, the process begins at step 702 , and then proceeds to step 704 where the AP sends a wakeup announcement to an MT in a MAC frame. From step 704 control proceeds to step 706 , where a counter M is set to zero. From step 706 control proceeds to step 708 , where it is determined whether the wakeup announcement was a polling request to the MT. If yes, then control flows to step 710 , where the AP determines whether it has received a polling acknowledgment signal from the MT. If yes, then control proceeds from step 710 to step 718 , and the process ends. If no, then control proceeds from step 710 to step 712 , where the AP retransmits the polling request to the MT in a subsequent MAC frame at a next available opportunity. From step 712 , control proceeds to step 714 where the counter M is incremented. From step 714 , control proceeds to step 716 , where M is compared with a predetermined value M retransmissions . If M is greater than or equal to the predetermined value M retransmissions , then control proceeds from step 716 to step 718 and the process ends. If M is less than the predetermined value M retransmission , then control returns from step 716 to step 710 .
If in step 708 it is determined that the wakeup announcement was not a polling request, then control proceeds from step 708 to step 724 where the value of M is incremented. From step 724 , control proceeds step 726 , where the value of M is compared with a predetermined value R retransmssions . If the value of M is greater than or equal to the predetermined value R retransmissions , then control proceeds from step 726 to step 718 and the process ends. If the value of M is less than the predetermined value R retransmissions , then control proceeds from step 726 to step 720 , where the AP determines whether the MT has successfully received the wakeup announcement. The AP can generally determine whether the MT has successfully received the wakeup announcement, for example, using Automatic Repeat Request (ARQ) principles well known in the art. When the MAC layer operates in an unacknowledged mode, or when data is time sensitive and obsolete if not received when originally sent, the predetermined value R retransmissions can be set equal to 1 (one). If in step 720 the AP determines that the MT has successfully received the wakeup announcement, then control proceeds from step 720 to step 718 , and the process ends. If the MT did not successfully receive the wakeup announcement, then control proceeds from step 720 to step 722 , where the AP retransmits the wakeup announcement and any associated pending downlink data for the MT in a subsequent MAC frame at a next available opportunity. From step 722 , control proceeds to step 718 , and the process ends.
FIG. 8 shows internal details of an exemplary AP in accordance with exemplary embodiments of the invention. In particular, an AP 800 can include a scheduler entity 802 and a sleep announcement entity 804 .
Those skilled in the art will appreciate that the features described above can be variously combined.
Copending and commonly owned application, entitled “Mobile Terminal Sleep Phase Assignment and Announcement in a Wireless Local Area Network” and identified with Attorney Docket No. 040000-528 and filed on the same day as the present application, is hereby incorporated by reference.
Those skilled in the art will recognize that the features and embodiments described in the copending and commonly owned application referenced above can be advantageously combined with the features and embodiments described in the present application.
Ericsson documents no. ERVS-99013, ERVS-99021 and ERVS-99022 are hereby incorporated by reference, and are also filed herewith as Appendices A, B, and C, respectively.
An approved portion of the proposed ETSI HIPERLAN Type 2 standard that was published on Apr. 7, 1999, is incorporated herein by reference, and is also filed herewith as Appendix D.
It will be appreciated by those skilled in the art that the present invention can be embodied in other specific forms without departing from the spirit or essential characteristics thereof, and that the invention is not limited to the specific embodiments described herein. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the appended claims rather than the foregoing description, and all changes that come within the meaning and range and equivalents thereof are intended to be embraced therein. | 4y
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This is a division of application Ser. No. 133,028, filed Mar. 24, 1980, now abandoned.
FIELD OF THE INVENTION
This invention relates in general to electrodes on solar cells, and in particular to a solar cell with wrap-around electrodes and to a method for making such a cell.
BACKGROUND OF THE INVENTION
It is known in the art to prepare silicon solar cells having electrodes and electrode contacts on one side, ane preferably the back surface, of the solar cell. In this regard see, for example, U.S. Pat. No. 3,261,074, U.S. Pat. No. 3,990,100, U.S. Pat. No. 4,157,926 and U.S. Pat. No. 3,502,507 for a description of such cells, their advantages and method of preparation.
From the foregoing, it should be apparent that there are many approaches to preparing solar cells having all the electrical contacts on the back surface of the solar cell.
The present invention is concerned with an improved processing technique for making a solar cell with a wrap-around electrode such that all the electrical contacts shall be on the back surface of the solar cell.
SUMMARY OF THE INVENTION
Broadly stated, the present invention comprises a solar cell having a plurality of current collectors on the top solar sensitive surface of the cell in electrical contact with a first electrode extending in a strip around at least a portion of the top surface of the cell, the edge thereof, and in a strip around the bottom surface of the cell. A second electrode is provided on the bottom surface of the cell separated from said first electrode by a nonmetallized area having at the surface thereof a junction of semiconductor material of opposite conductivity types.
In general, the solar cell is made by the steps of providing a semiconductor body of one conductivity type with a surface layer of opposite conductivity type to form a junction with the bulk portion of the semiconductor body. The surface layer provided extends over the entire top solar sensitive surface of the semiconductor body, around the end edges thereof and onto a strip around the perimeter of the back surface of the semiconductor body. A grid and electrode pattern is provided on the light sensitive top surface of the semiconductor body and to a strip around at least a portion of the top surface of the semiconductor, the edge thereof and a strip around the perimeter back surface of the semiconductor. A second electrode pattern is provided on the back surface of the semiconductor which is separated from the perimeter by a non-metallized P-N junction region. A solar cell is thereby provided having a top electrode which wraps around the cell to the back surface thereof so that all electrical contacts with the solar cell may be made on the back surface of the cell.
In a particularly preferred embodiment of the present invention, the semiconductor body of one conductivity type is provided with a surface layer of opposite conductivity type which extends around the edge of the semiconductor body into a narrow band on the perimeter of the semiconductor by first providing an assembly of two semiconductor bodies which are in contact with and separated by an inert separator which has the same geometry but with dimensions smaller than the dimensions of the semiconductor body, and thereafter placing the assembly in an atmosphere of predetermined temperature and composition sufficient to diffuse a material onto the surface of the semiconductor body, thereby forming the surface layer of opposite conductivity type.
The invention will be better understood when read in light of the detailed description and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view partly in section of a solar cell with wrap-around electrodes.
FIG. 2 is an isometric drawing partly in perspective showing one step of the preferred technique for forming a solar cell in accordance with the invention.
FIG. 3 is a side elevation illustrating another step in the method of the present invention.
FIG. 4 is a cross-sectional view illustrating another aspect of the present invention.
FIG. 5 is a top plan view showing the metal pattern for electrical contacts applied to the top surface of a solar cell prepared in accordance with the present invention.
FIG. 6 is a top plan view of the bottom surface of a metallized solar cell prepared in accordance with the process of the present invention.
FIG. 7 is a perspective view of an alternate embodiment of the solar cell of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Turning now to the drawings, and more particularly to FIG. 1, a particularly preferred solar cell 10 of this invention has a wrap-around electrode 11 extending completely around the top perimeter of the semiconductor body over the edge thereof and completely around the perimeter of the bottom portion of the semiconductor body. The cell has a plurality of finger-like metallic current collectors 12 on the top surface of the solar cell which are in electrical contact with electrode 11. Optionally and preferably the cell is also provided on the top surface with a bus bar 14 also in electrical contact with wrap-around electrode 11 and current collectors 12. A second electrode 15 covers a substantial portion of the back surface of the solar cell 10. Interposed between the electrode 15 and electrode 11 on the back surface is a non-metallized area 16 having a semiconductor junction exposed at the surface of area 16. The semiconductor body 9 is of one conductivity type and has a surface layer 8 of opposite conductivity type which covers the top surface of the semiconductor and extends around the edge of the semiconductor to and over the perimeter of the back surface of the semiconductor body.
As will be appreciated, the semiconductor body may be any material suitable for forming a solar cell; however, in the description which follows reference will be made specifically to silicon. Indeed, for convenience, the semiconductor body 9 will be referred to generally as a P-type silicon and the surface layer 8 as an N-type silicon.
In the preparation of solar cell 10, two P-type silicon discs 17, for example, are placed in an appropriate caddy for diffusion of an N-type layer onto the surface of the silicon by convential diffusion techniques. The silicon discs 17 are arranged in sandwich fashion as shown in FIGS. 2 and 3 with a chemically inert spacer 18 between the cells. This spacer has the same shape as the silicon solar cell but is of a smaller diameter so that a rim 19 in the range of, for example, .05 to .10 inches is provided around the perimeter of the surface of the silicon wafers facing each other in the sandwich construction so that the N-type material diffuses in the rim region 19 as well as on the major top surface 20 of the silicon wafers 17. Preferably, the spacer 18 is made of quartz. Optionally spacer 18 also is provided with cut-out portions 21 which will serve to define tab regions 22 on the back surface of the silicon solar cell which ultimately will define a contact region on the wrap-around electrode as is described in greater detail hereinafter. The sandwich of silicon wafers 17 and spacer 18 are placed in an appropriate atmosphere, for example, a phosphorus containing atmosphere, at temperatures, for example of about 850° C. to about 900° C. for about one-half hour thereby providing a surface layer 23 of N-type conductivity to a depth of a fraction of a micron not only on the top surface 20 of the silicon wafer 17 but also extending around the edge of the wafer and into the rim region 19 on the back surface of the wafer 17 (see FIG. 4).
Next, the surface of the silicon wafer 17 is masked, for example with a rubber mask, to cover a substantial area of diffused rim region 19 on the back surface of the wafer 17. After masking, the remaining exposed portion of the wafer 17 is sandblasted in the conventional manner to remove any phosphorus diffused region in the exposed area. After removal of the mask, this abrasive treatment leaves a well-defined junction between N-type diffused silicon around the back surface of the wafer 17 and a central P-type region, the junction being shown as dotted line 31 of FIG. 6.
Subsequently, the entire wafer is cleaned by conventional cleaning agents, such as hydrofluoric acid to remove the phosphorus glass and the abrasive residues. For example, the wafer is washed in a bath composed of aqueous HF and then rinsed with deionized water and dried.
Thereafter a resist pattern is applied to the front surface of the diffused and cleaned wafer 17 by a suitable patterning technique, such as photolithography or silk screening. In FIG. 5 the shaded areas 27 are the areas covered by the appropriate screening ink. Thus, the unmasked portion 26, which will be metallized, defines the metallization pattern on the top surface of the wafer. As can be seen, the unmasked area has a portion which extends around the perimeter of the silicon wafer and over the edge thereof. Additionally, on the back surface of the wafer, similar resist pattern is formed so as to provide a region 16 on the back surface of silicon wafer 17 which will not be metallized. This region covers the boundary (shown by dotted line 31) between the N- and P-type semiconductor materials. Thus, the area within line 31 on the back surface of wafer 17 is a P-type semiconductor material and region 39 encompassing the area from line 31 to the edge of the wafer is an N-type semiconductor material. Also, as can be seen as a result of the patterning, the portion 29 around the perimeter of wafer 17, the tab regions 22 and the central area 30 of the wafer 17 remain available for metallization.
After applying the appropriate screening ink in the pattern outlined above, the entire wafer is metallized with a conventional electroless nickel plating solution. The nickel plated portion on the front surface 26 extends, of course, around the rim of the wafer onto the back surface 29 and 30 including the tab regions 22. Other plating solutions, of course, could be used such as cobalt or copper.
After metallizing the wafer the resist is removed, typically by washing with an appropriate solvent. In general, solvents such as acetone, hydrocarbons and chlorohydrocarbons are appropriate solvents. The choice of solvent depends upon the choice of resist used. Since these are commercially available materials, it is best to follow the manufacturer's prescribed techinque for removal of the resist.
Next the plated portions 26, 29 and 30 are tinned or coated with solder to permit ohmic connection to the nickel plated portions. Moveover, since the nickel plate is thin and of relatively high restivity, the solder increases the efficiency of the cell as well as improving the electrical conductivity of contacts made to the cell. Also, it should be noted that during the electroless nickel metallization and solder coating procedures a continuous ring of solder forms around the rim for a small distance in from the rim on both sides of the silicon solar cell. In this manner a wrap-around contact is formed automatically during the metallization procedure.
Finally, the wafer is etched in hot caustic to remove work-damaged silicon from the P-N junction region in area 16 on the back of the wafer. During this step, the front surface may be protected by a coating of a suitable resist material such as black wax or an asphalt-based screen-printed ink. Following the etching step, the resist layer is removed with a suitable solvent, such as chlorinated hydrocarbons. If desired, the wafer may then be treated with a room temperature solution of hydrogen peroxide, rinsed in water and dried. These treatments are typical treatments employed in the conventional techniques of forming silicon power devices. As desired, an antireflection coating may be applied to the front surface of the cell by any of the techniques well known in the art, such as the evaporation or sputtering of tantalum oxide, or the spray coating of silicon-titanium oxide.
The resultant solar cell of FIG. 1 is seen to have an electrode 11 which wraps around from the front surface of the silicon solar cell to the perimeter of the rear surface of the solar cell. Thus, in this manner, electrical contacts can be made on the back surface of the wafer to the electrodes 11 and 15 thereby providing numerous advantages, particularly in the packaging of the solar cells in modules.
In the embodiment described above, the wrap-around electrode extended completely around the perimeter, both top and bottom of the circular solar cell. It should be readily apparent that the electrode need only to cover a portion of the perimeter of the cell. For example, in the embodiment shown in FIG. 7 the solar cell 70 is a rectangular cell having wrap-around electrode 71 extending along only a portion of the top perimeter of the cell around the edge and on a strip on a portion of the back surface of the cell. As shown, solar cell 70 is provided with a plurality of current collectors or fingers 72 on the top light incident surface of cell 70. Also provided is a second electrode 75, located on the bottom of the cell 70. Interposed between electrodes 71 and 75 on the back of cell 70 is a nonmetallized area 76 having a semiconductor junction exposed at the surface of the area 76.
As should be readily apparent, while the foregoing process is described in connection with specifically shaped solar cells, the process is equally adaptable to other shapes such as semicircular and ribbon shaped solar cells.
Finally, although this invention has been described with respect to its preferred embodiments, it should be understood that many variations, modifications will now be obvious to those skilled in the art, and it is intended, therefore, that the scope of the invention be limited not by the specific disclosure herein but only by the appended claims. | 4y
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FIELD OF INVENTION
[0001] The present invention relates to the field of gas turbines. It refers to a gas turbine rotor with a cooling air slot according to the preamble of claim 1 , and also refers to a method for producing such a gas turbine rotor.
BACKGROUND
[0002] A gas turbine rotor, as is used for example in the case of types GT11 and GT13 gas turbines of the assignee of the present application, is known from publication EP-A2-1 705 339 (see FIG. 1 there). Such a gas turbine rotor is also shown in FIGS. 1 and 2 of the present application. The gas turbine rotor 10 which is shown in FIG. 1 is constructed from rotor disks which are welded together in a known manner in the direction of the axis 18 and has a compressor section 11 and a turbine section 12 , between which the combustion chamber is arranged in the assembled state of the gas turbine. FIG. 3 corresponds to FIG. 5 from EP-A1-1 862 638 and shows an enlarged detail of the turbine section 11 which adjoins the combustion chamber.
[0003] In the two sections 11 and 12 , a plurality of rows of rotor blades, which are not shown in FIG. 1 , are fastened one behind the other in the axial direction. The rotor blades are inserted by correspondingly designed blade roots into encompassing rotor blade slots ( 37 in FIG. 3 ). A heat accumulation segment carrier 35 is formed upstream of the first rotor blade slot 37 of the turbine section 11 in the flow direction and has a multiplicity of axial heat accumulation segment slots 15 which are distributed over the circumference. Beneath the heat accumulation segment carrier 35 an encompassing cooling air slot 13 is arranged, which by means of axial cooling air holes 14 ( FIG. 2 ) which are distributed over the circumference is exposed to admission of compressed cooling air from the compressor section of the gas turbine. The cooling air slot 13 is partially covered by bridges 36 which are spaced apart by means of gaps 38 and limit access to the cooling air slot 13 to the gaps 38 .
[0004] In such gas turbine rotors, encompassing incipient cracks, or cracks 17 ( FIG. 2 ), can occur in the slot base 16 of the cooling air slot 13 depending upon the operating mode and operating time. The incipient cracks grow further with each start-up and after reaching a specific crack depth lead to unstable crack propagation as a result of rotating bending stress and fundamentally impair the component operational safety. Therefore, incipient cracks, especially in the slot base 16 of turbine shafts, must be reliably avoided.
[0005] Corresponding strength calculations, which are conducted according to the findings with crack development, prove that the intense operationally induced heat yield during start-up of the plant, in conjunction with the high notch effect of the slot geometry according to the previous design according to FIG. 2 , leads to significant alternating plastifications which cause the crack formation.
[0006] A slot geometry for newly manufactured rotors therefore takes into consideration the two criteria (heat yield as load shock and notch effect of the old slot geometry) with a wider slot for reducing the air velocity and less sharp transition radii of the slot base to the slot flanks. The previous repair methods are based on constructing the new slot geometry by means of machining out the slot, i.e. by increasing the old slot geometry. In this case, the bridges 36 of the heat accumulation segment carriers 35 are removed over the slot width, which reduces the supporting stability of the remaining bridge sections as a guide for the slot-covering cover segments, or requires the subsequent arrangement of the bridges 36 by means of welded connections and post-heat treatment of the latter.
SUMMARY
[0007] The disclosure is directed to a method for machining a gas turbine rotor having a cooling air slot, which concentrically extends around an axis of the gas turbine rotor and is supplied with compressed cooling air via axial cooling air holes, which at the side lead into the slot base of the cooling air slot, and the opening of which is covered by bridges which are arranged in a distributed manner over the circumference and spaced apart from each other by gaps. The method includes lowering a material-removing tool in the gaps between the bridges one after the other into the cooling air slot. The method also includes machining the slot base of the cooling air slot over the entire circumference, and widening, in width the slot base of the cooling air slot as a result of the material removal in such a way that it has a tear-shaped cross-sectional contour with a constriction which lies at the level of the bridges.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The invention is to be subsequently explained in more detail based on exemplary embodiments in conjunction with the drawings. In the drawings:
[0009] FIG. 1 shows in a perspective, partially sectioned view an as known per se gas turbine rotor with a cooling air slot in the turbine section;
[0010] FIG. 2 shows an enlarged detail from FIG. 1 with the cooling air slot and an associated cooling air hole;
[0011] FIG. 3 shows a perspective view of the heat accumulation segment slot of the gas turbine rotor from FIG. 1 with the cooling air slot lying beneath it;
[0012] FIG. 4 shows the principle of machining the cooling air slot according to the invention, and
[0013] FIG. 5 shows a flow diagram according to an exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0014] Introduction to the Embodiments
[0015] It is therefore an object of the invention to provide a method for machining a gas turbine rotor, with which in the case of crack-prone cooling air slots with partially overlapped bridges the slot base and the slot flanks of the cooling air slots are made free of cracks by forming a new slot contour without welds with subsequent heat treatment in conjunction with the bridge renewal being necessary.
[0016] A further object of the invention is based on using a slot shape with which operationally induced component reaction cracks are avoided.
[0017] The object is achieved by the entirety of the features of claim 1 . It is an essential feature for the solution that a material-removing tool, particularly a milling tool, is lowered in the gaps between the bridges one after the other into the cooling air slot, and in this way the slot base of the cooling air slot is machined over the entire circumference, and that the slot base of the cooling air slot is widened in width as a result of the material removal in such a way that it has a tear-shaped cross-sectional contour with a constriction which lies at the level of the bridges.
[0018] According to one development of the invention a specific section of the cooling air slot is machined through each of the gaps, wherein the machining sections which are associated with adjacent gaps overlap.
[0019] A further development of the method is that the material-removing tool is moved in a programmed controllable manner in the cooling air slot in a plurality of planes, in that the gas turbine rotor is rotatably supported around its axis, and that once the associated section of the cooling air slot is machined through a gap the material-removing tool is withdrawn from the cooling air slot, the gas turbine rotor is rotated around its axis by a predetermined angle, and the material-removing tool is lowered in a new gap into the cooling air slot for machining.
[0020] Another development is that the machining of the slot base is conducted in such a way that the cooling air slot in the slot base has a crack-resistant slot shape with a notch factor of <1.5.
[0021] The material-removing tool for machining the slot base is preferably controlled according to a numerical control program (NC-program). In particular, a component-specific cross-sectional final profile of the slot base is determined in this case from the individual operating data of the gas turbine rotor, wherein the cross-sectional final profile can be produced from one or more cross-sectional master profiles by the use of distortion parameters which are determined, a corresponding NC-program for controlling the material-removing tool is associated with each cross-sectional master profile, and the determined distortion parameters are used for adapting the NC-program for the creation of the cross-sectional final profile. The adapting of the NC-program is preferably undertaken by the distortion parameters offline with a postprocessor, or online in the machine control system.
[0022] If the gas turbine rotor, before the machining in the cooling air slot, has cracks of a specific crack depth, the cross-sectional final profile which is to be achieved as a result of the machining is preferably influenced by the type and state of the cracks.
[0023] Detailed Description
[0024] In FIG. 4 , a cooling air slot 13 , as it is also shown in FIG. 2 and as it is before the machining, is drawn in with broken lines. The cooling air slot 13 has a very narrow slot base 16 which leads to the compressed air which flows in through the cooling air holes 14 locally heating the opposing slot flanks in specific operating states and causing thermal stresses in the cooling air slot. It is the aim of the machining method, without intervention into the structure of the bridges 36 ( FIG. 3 ), to widen the cooling air slot which lies beneath them, starting from the cross-sectional contour of the cooling air slot 13 in FIG. 4 , so that the harmful effects of the cooling air which flows into the slot can be substantially alleviated.
[0025] For this purpose, according to FIG. 4 a material-removing tool, especially with a longish milling body 22 , which rotates around an axis 23 , is lowered in the gaps 38 between the bridges 36 one after the other into the cooling air slot, and the slot base 16 of the cooling air slot is widened over the entire circumference so that a cross-sectional profile according to the slots which are shown in FIG. 4 as a cooling air slot 19 or cooling air slot 19 ′ results. The milling tool 22 in this case must not only be rotated the axial direction but also in the circumferential direction. As a result of this type of machining, the slot base of the cooling air slot is widened in width (b 1 , b 2 ) by material removal in such a way that it has the tear-shaped cross-sectional contour which is shown in FIG. 4 with a constriction 20 which lies at the level of the bridges 36 . Furthermore, as a result of the rotation in the circumferential direction, a specific circumferential section of the cooling air slot is machined through each of the gaps 38 , wherein the machining sections which are associated with adjacent gaps overlap. A uniformly widened slot base cross section over the circumference, as is to be seen in FIG. 4 , altogether results in this way despite the geometric limitation during the individual machining steps. The rounded transition between slot flanks and slot base in this case preferably has the shape of an elliptical section (ellipse 24 ).
[0026] The slot shape in this case is determined by a slot width (b 1 , b 2 ) as a flow path length which alleviates the effect of the air from the compressor, which flows in through the cooling air holes, in such a way that this does not bring about impermissible heat yield into the slot flanks. For this purpose the slot base has a tear-shaped formation with a constriction 20 and a transition 21 between a widened section and a section of constant width with the aim of a notch factor of <1.5 as a design feature of the crack-resistant slot shape. From the individual operating data of each gas turbine rotor the component-specific shape of the slot base is determined by known mathematical methods.
[0027] The new slot shape is defined according to FIG. 5 by a flow diagram 40 by the current damage state first being determined. Taking into consideration the manner of use of the generator (from operating data 26 ), a new final profile 29 , 31 is generated. For describing the final profile 29 , 31 , a master profile 28 , 30 is used which is distorted with specific distortion parameters 27 . A plurality of master profiles 28 , 30 can be given from which a profile which is specific for this rotor is selected. An NC-program, which was previously manually generated, is associated with each master profile. The determined distortion parameters 27 are used in order to also adapt the NC-program in an NC-control system 32 . Re-programming is therefore dispensed with. The necessary coordinate transformations are converted either offline in a postprocessor or online directly in the machine control system. The NC-control system 32 then controls a milling machine 25 with the milling body 22 which is introduced through the gaps 38 into the cooling air slot 13 of the gas turbine rotor 10 which is to be machined. A rotary drive 33 , which can measure the rotational angle at the same time, is connected to the NC-control system 32 .
[0028] The tool 22 is guided through the gaps 38 between the bridges/support elements 36 which cover the slot opening so that these are not affected by the cutting process. The tool 22 , as described above, by a suitable drive unit which is fastened outside the slot, is moved in a programmed controllable manner in the slot in a plurality of planes. By variable equipping of the tool with different cutting bodies or different tool shapes the surface roughness of the machining zones and the surface milled profile can be varied. The drive unit can be an externally seated (above the slot) speed-controllable motor.
[0029] The component surface, which is milled in a defined manner in contour and depth, is the aim of the milling process, wherein the surface depth which is to be milled is predetermined by the crack depth which is determined before or during the milling process, or by a new slot shape configuration. The tool in this case machines a slot surface which is delimited as a result of the movement space of the window between the bridges over the slot. In order to free the entire slot circumference of cracks by milling by metal cutting, a stepwise repositioning of the construction of rotor and tool is carried out until the slot surfaces which are freed of cracks or are to be newly contoured are covered.
LIST OF DESIGNATIONS
[0000]
10 Gas turbine rotor
11 Compressor section
12 Turbine section
13 Cooling air slot
14 Cooling air hole
15 Heat accumulation segment slot
16 Slot base
17 Crack
18 Axis (gas turbine rotor)
19 , 19 ′Cooling air slot (machined)
20 Constriction
21 Transition
22 Milling body
23 Axis (milling spindle)
24 Ellipse
25 Milling machine
26 Operating data
27 Distortion parameter
28 , 30 Master profile
29 , 31 Final profile
32 NC-control system
33 Rotary drive (with rotational angle measurement)
35 Heat accumulation segment carrier
36 Bridge
37 Rotor blade slot
38 Gap
40 Flow diagram
b 1 , b 2 Width | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2008-66067 filed on Mar. 14, 2008, the entire contents of which are incorporated herein by reference.
BACKGROUND
[0002] 1. Field
[0003] The present invention relates to a cache memory system, a data processing apparatus, and a storage apparatus, and method thereof.
[0004] 2. Description of the Related Art
[0005] In a data processing apparatus, since an access latency from a processor to a main storage apparatus includes many stall cycles, a cache memory which can be accessed speedily by the processor is often provided in order to reduce the penalty associated with access from the processor to the main storage apparatus. However, when a command associated with access to a storage area where no copy of data of the main storage apparatus exists in the cache memory is executed by the processor, a cache miss hit occurs. At that time, when a load command is executed or a store command is executed in the cache memory having a write-allocating system, since an operation (move-in operation) for preparing a copy of data of the main storage apparatus in the cache memory is required, a penalty for executing a command of the processor will be caused to a certain degree.
[0006] Although occurrence frequency of the cache miss hit can be reduced by increasing capacity of the cache memory, it is not easy to increase capacity of a memory which can be accessed speedily by the processor due to trade-off between operating frequency and cost. Therefore, a method is often used for reducing the penalty associated with occurrence of the cache miss hit by providing a primary cache memory which can be accessed in the same operating speed as that of the processor and a high-capacity secondary cache memory which cannot be accessed in the same operating speed as that of the processor but can be accessed more speedily than the main storage apparatus (that is, by providing a hierarchical structure in the cache memory). In the case where a hierarchical cache memory is used in a data processing apparatus having a multi-processor structure, a storage hierarchy which is closer to the main storage apparatus is often shared among a plurality of processors. In this case, a cache control apparatus for assuring coherency of data among the plurality of processors may be provided.
[0007] Further, when data of the corresponding entry of the cache memory is rewritten by a store command (writing store data), data transferred to the cache memory by the move-in operation is never referred to by the processor. Therefore, the move-in operation has been performed uselessly and it may cause problems in processing performance and power consumption of the data processing apparatus.
[0008] In addition, techniques related to the cache memory are disclosed in, for example, Japanese Patent No. 2552704, Japanese Patent No. 3055908, and Japanese Patent No. 2637320.
SUMMARY
[0009] According to an aspect of an embodiment of the invention, a method, apparatus, and computer readable recording media thereof is provided in which a computer processor implements a no-move-in store command as a store command that does not require a move-in and the no-move-in store command, when executed by the processor, controls not to request a move-in even if the cache miss hit occurs.
[0010] According to an aspect of an embodiment, there is provided a cache memory system including: a plurality of first storage hierarchical units provided individually to a plurality of processors; a second storage hierarchical unit provided commonly to the plurality of processors; and a control unit for controlling data transfer between the plurality of first storage hierarchical units and the second storage hierarchical unit, wherein each of the plurality of processors is capable of executing a no-data transfer store command as a store command that does not require data transfer from the second storage hierarchical unit to the corresponding first storage hierarchical unit, each of the plurality of first storage hierarchical units outputs a transfer-control signal in response to occurrence of a cache miss hit when executing the no-data transfer store command by the corresponding processor, and the control unit updates state information of a first storage hierarchical unit corresponding to a first processor included in the plurality of processors without performing data transfer at least from the second storage hierarchical unit to the first storage hierarchical unit corresponding to the first processor with respect to a storage area designated by the first storage hierarchical unit corresponding to the first processor in the case where the transfer-control signal is output by the first storage hierarchical unit corresponding to the first processor.
[0011] Other aspects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a diagram representing an embodiment of the present invention;
[0013] FIGS. 2A and 2B are diagrams representing an operation of a conventional data processing apparatus;
[0014] FIGS. 3A and 3B are diagrams representing an operation of the data processing apparatus represented in FIG. 1 ;
[0015] FIGS. 4A and 4B are diagrams representing another operation of the conventional data processing apparatus; and
[0016] FIGS. 5A and 5B are diagrams representing another operation of the data processing apparatus represented in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Hereinbelow, a preferred embodiment will be described in accordance with the accompanying drawings wherein like numerals refer to like parts throughout. FIG. 1 represents an embodiment. A data processing apparatus 10 according to the embodiment has Central Processing Units (CPU) 20 a , 20 b and 20 c (having a CPU core 21 and a primary cache 22 ), and a secondary cache 30 (having a cache control apparatus 31 ) shared by the CPUs 20 a , 20 b and 20 c . The secondary cache 30 is connected to a main storage apparatus, though it is not represented in the drawing.
[0018] The CPU core 21 has a command decoder 211 and can execute a no-move-in store command as a store command which does not require move-in (transferring data from the secondary cache 30 to the primary cache 22 ) in addition to various known commands. When the CPU core 21 executes the no-move-in store command, the CPU core 21 outputs a move-in prohibition signal S 1 (signal representing that move-in is not required) to the primary cache 22 .
[0019] The primary cache 22 has cache Random Access Memories (RAM) 221 a and 221 b , selectors 222 , 223 and 224 , tag RAMs 225 a and 225 b , an address comparator 226 , a cache state information storing circuit 227 , and a control circuit 228 . For example, in the primary cache 22 , a write-allocating system is used. In addition, in the primary cache 22 , the MOSI cache coherency protocol/system is used for assuring a cache coherency.
[0020] The cache RAMs 221 a and 221 b write output data of the selector 222 into an entry depending on an output address of the CPU core 21 according to writing instructions of the control circuit 228 . Further, the cache RAMs 221 a and 221 b read data from the entry depending on the output address of the CPU core 21 according to reading instructions of the control circuit 228 and output the read data to the selector 223 . The selector 222 selects output data of the CPU core 21 or output data of the secondary cache 30 according to selecting instructions of the control circuit 228 and outputs the selected output data to the cache RAMs 221 a and 221 b . The selector 223 selects output data of the cache RAM 221 a or output data of the cache RAM 221 b according to selecting instructions of the control circuit 228 and outputs the selected output data to the selector 224 and the secondary cache 30 . The selector 224 selects output data of the selector 223 or output data of the secondary cache 30 according to selecting instructions of the control circuit 228 and outputs the selected output data to the CPU core 21 .
[0021] The tag RAMs 225 a and 225 b write a part of an address into the entry depending on the output address of the CPU core 21 according to writing instructions of the control circuit 228 . The tag RAMs 225 a and 225 b read the address from the entry depending on the output address of the CPU core 21 according to reading instructions of the control circuit 228 and output the read address to the address comparator 226 . The address comparator 226 compares a part of the output address of the CPU core 21 with the output address of the tag RAMs 225 a and 225 b and outputs an address comparing result signal S 2 (signal representing whether the addresses match or not) to the control circuit 228 . The cache state information storing circuit 227 stores state information of each entry which is embodied by a register or the like and is used for controlling cache coherency. The state information is set to any one of a modified (M) state, an owned (O) state, a shared (S) state and an invalid (I) state by the control circuit 228 .
[0022] The control circuit 228 performs various operations for controlling the entire primary cache 22 . The control circuit 228 determines a cache hit/cache miss hit based on the address comparing result signal S 2 . When the control circuit 228 recognizes occurrence of the cache miss hit, upon output of the move-in prohibition signal S 1 by the CPU core 21 , a no-move-in store request signal S 3 (signal representing that a cache miss hit occurs when executing a no-move-in store command) is output to the secondary cache 30 (cache control apparatus 31 ). The cache control apparatus 31 performs an operation for controlling data transfer between the primary cache 22 (control circuit 228 ) of the CPUs 20 a , 20 b and 20 c and the secondary cache 30 , an operation for assuring the cache coherency or the like.
[0023] Various control signals such as a move-in request signal (signal for requesting data transfer from the secondary cache 30 to the primary cache 22 ) are output from the primary cache 22 (control circuit 228 ) of the CPUs 20 a , 20 b and 20 c to the secondary cache 30 (cache control apparatus 31 ) when necessary, though it is not represented in the drawing. Further, various control signals such as a flush request signal (signal for requesting to write back dirty data) or an invalidate request signal (signal for requesting to set the state information to the invalid state) are output from the secondary cache 30 (cache control apparatus 31 ) to the primary cache 22 (control circuit 228 ) of the CPUs 20 a , 20 b and 20 c when necessary.
[0024] FIGS. 2A and 2B represent an operation of a conventional data processing apparatus. The conventional data processing apparatus 10 ′ has CPUs 20 a ′, 20 b ′ and 20 c ′ and a secondary cache 30 ′. The CPUs 20 a ′, 20 b ′ and 20 c ′ are the same as the CPUs 20 a , 20 b and 20 c represented in FIG. 1 except that the CPUs 20 a ′, 20 b ′ and 20 c ′ do not have a mechanism related to the no-move-in store command. The secondary cache 30 ′ is the same as the secondary cache 30 represented in FIG. 1 except that the secondary cache 30 ′ does not have a mechanism related to the no-move-in store request signal.
[0025] The operations represented in FIGS. 2A and 2B are performed when a cache miss hit occurs upon executing a store command for designating an address A as a store destination address at the CPU 20 a ′ (primary cache) in the case where line data corresponding to the address A does not exist in the modified cache state in the CPUs 20 b ′ or 20 c ′ (primary cache). In addition, it is previously known that the line data corresponding to the address A is never referred to at the CPU 20 a′.
[0026] When the cache miss hit occurs, upon executing the store command for designating the address A as a store destination address at the CPU 20 a ′, as represented in FIG. 2A , a move-in request signal is output from the CPU 20 a ′ to the secondary cache 30 ′ (cache control apparatus 31 ′) (O 1 ). With this operation, as represented in FIG. 2B , data of the corresponding line (line corresponding to the address A designated by the CPU 20 a ′) is transferred from the secondary cache 30 ′ to the CPU 20 a ′ by the move-in operation (O 2 ). At the CPU 20 a ′ (primary cache), after the data transferred from the secondary cache 30 ′ is written in the corresponding entry, the execution of the store command is completed by writing the store data into the corresponding entry. Thereafter, the state information of the corresponding entry of the cache state information storing circuit 227 ′ is updated from “I” to “M” (O 3 ). Since there is the circumstance when data transferred from the secondary cache 30 ′ to the CPU 20 a ′ by the move-in operation is never referred to at the CPU 20 a ′, data transfer (move-in) from the secondary cache 30 ′ to the CPU 20 a ′ is uselessly performed.
[0027] FIGS. 3A and 3B represent operations of the data processing apparatus represented in FIG. 1 . The operations represented in FIGS. 3A and 3B are performed when a cache miss hit occurs and executing a no-move-in store command for designating an address A as a store destination address at the CPU 20 a (primary cache) in the case where line data corresponding to the address A does not exist in the modified cache state in the CPUs 20 b or 20 c (primary cache). In addition, it is previously known that the line data corresponding to the address A is never referred to at the CPU 20 a.
[0028] When the cache miss hit occurs, upon executing the no-move-in store command for designating the address A as a store destination address at the CPU 20 a , as represented in FIG. 3A , not a move-in request signal but a no-move-in store request signal is output from the CPU 20 a to the secondary cache 30 (cache control apparatus 31 ) (O 1 ). With this operation, as represented in FIG. 3B , the move-in operation is not performed (O 2 ), but only an operation related to assuring cache coherency is performed in the cache control apparatus 31 of the secondary cache 30 . At the CPU 20 a , upon outputting the no-move-in store request signal, the CPU 20 a completes execution of the store command by writing (i.e., directly writing) the store data into the corresponding primary cache 22 entry. Thereafter, the state information of the corresponding entry of the cache state information storing circuit 227 is updated from “I” to “M” (O 3 ). As described above, the data processing apparatus 10 represented in FIG. 1 differs from the conventional data processing apparatus 10 ′ (represented in FIGS. 2A and 2B ), so that useless data transfer from the secondary cache 30 to the CPU 20 a associated with the move-in operation is avoided and data coherency among the CPUs 20 a , 20 b and 20 c is assured.
[0029] FIGS. 4A and 4B represent another operation of the conventional data processing apparatus. The operations represented in FIGS. 4A and 4B are performed when a cache miss hit occurs and executing a store command for designating an address A as a store destination address at the CPU 20 a ′ (primary cache) in the case where line data corresponding to the address A exists in the modified cache state in the CPU 20 c ′ (primary cache). In addition, it is previously known that the line data corresponding to the address A is never referred to at the CPU 20 a′.
[0030] When the cache miss hit occurs, upon executing the store command for designating the address A as a store destination address at the CPU 20 a ′, as represented in FIG. 4A , a move-in request signal is output from the CPU 20 a ′ to the secondary cache 30 ′ (cache control apparatus 31 ′) (O 1 ). With this operation, as represented in FIG. 4B , a flush request signal is output from the secondary cache 30 ′ (cache control apparatus 31 ′) to the CPU 20 c ′ (O 2 ). Therefore, dirty data of the corresponding line is transferred from the CPU 20 c ′ to the secondary cache 30 ′ by the flush operation (O 3 ), and at the CPU 20 c ′, the state information of the corresponding entry of the cache state information storing circuit 227 ′ is updated from “M” to “I” (O 4 ). Thereafter, data transferred from the CPU 20 c ′ to the secondary cache 30 ′ is transferred from the secondary cache 30 ′ to the CPU 20 a ′ by a move-in operation (O 5 ). At the CPU 20 a ′ (primary cache), after data transferred from the secondary cache 30 ′ is written into the corresponding entry, the execution of the store command is completed by writing store data into the corresponding entry and the state information of the corresponding entry of the cache state information storing circuit 227 ′ is updated from “I” to “M” (O 6 ). Since data transferred from the secondary cache 30 ′ to the CPU 20 a ′ by the move-in operation is never referred to at the CPU 20 a ′, data transfer (flush) from the CPU 20 c ′ to the secondary cache 30 ′ and data transfer (move-in) from the secondary cache 30 ′ to the CPU 20 a ′ are uselessly performed.
[0031] FIGS. 5A and 5B represent another operation of the data processing apparatus represented in FIG. 1 . The operations represented in FIGS. 5A and 5B are performed when a cache miss hit occurs and executing a no-move-in store command for designating an address A as a store destination address at the CPU 20 a (primary cache) in the case where line data corresponding to the address A exists in the modified cache state in the CPU 20 c (primary cache). In addition, it is previously known that the line data corresponding to the address A is never referred to at the CPU 20 a.
[0032] When the cache miss hit occurs, upon executing the no-move-in store command for designating the address A as a store destination address at the CPU 20 a , as represented in FIG. 5A , not a move-in request signal but a no-move-in store request signal is output from the CPU 20 a to the secondary cache 30 (cache control apparatus 31 ) (O 1 ). With this operation, as represented in FIG. 5B , not a flush request signal but an invalidate request signal is output from the secondary cache 30 (cache control apparatus 31 ) to the CPU 20 c (O 2 ). Therefore, the flush operation is not performed (O 3 ), and at the CPU 20 c , the state information of the corresponding entry of the cache state storing circuit 227 is updated from “M” to “I” (O 4 ). Further, a move-in operation is not performed (O 5 ), and at the CPU 20 a , upon outputting the no-move-in store request signal, the CPU 20 a completes execution of the store command by writing (i.e., directly writing) the store data into the corresponding primary cache 22 entry. Thereafter, the state information of the corresponding entry of the cache state information storing circuit 227 is updated from “I” to “M” (O 6 ). As described above, the data processing apparatus 10 represented in FIG. 1 differs from the conventional data processing apparatus 10 ′ (represented in FIGS. 4A and 4B ), so that useless data transfer from the CPU 20 c to the secondary cache 30 associated with the flush operation and useless data transfer from the secondary cache 30 to the CPU 20 a associated with the move-in operation are avoided and data coherency among the CPUs 20 a , 20 b and 20 c is assured.
[0033] As described above, the data processing apparatus 10 according to the embodiment can reduce useless data transfer (memory access) between the primary cache 22 of the CPUs 20 a , 20 b and 20 c and the secondary cache 30 with/while assuring cache coherency. This will substantially contribute to improvement of the processing performance and reduction of the power consumption in the data processing apparatus 10 .
[0034] According to an aspect of the embodiments of the invention, any combinations of the described features, functions, operations, and/or benefits can be provided. The embodiments can be implemented as an apparatus (machine) that includes computing hardware (i.e., computing apparatus), such as (in a non-limiting example) any computer that can store, retrieve, process and/or output data and/or communicate (network) with other computers. According to an aspect of an embodiment, the described features, functions, operations, and/or benefits can be implemented by and/or use computing hardware and/or software. The apparatus (e.g., the data processing apparatus 10 ) comprises a controller (CPU) (e.g., a hardware logic circuitry based computer processor that processes or executes instructions, namely software/program), computer readable recording media (e.g., primary/secondary caches 30 , 22 , main storage apparatus, etc.), transmission communication media interface (network interface), and/or a display device, all in communication through a data communication bus. The results produced can be displayed on a display of the computing apparatus. A program/software implementing the embodiments may be recorded on computer readable media comprising computer-readable recording media, such as in non-limiting examples, a semiconductor memory (for example, RAM, ROM, etc.).
[0035] While the present invention has been described in detail, it is to be understood that the foregoing embodiment is only an exemplary embodiment. The present invention is not limited to the above embodiment and various changes/modifications and equivalents can be made within the spirit and scope of the present invention. | 4y
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This application is a continuation of U.S. application Ser. No. 08/088,033, filed Jul. 2, 1993, now abandoned.
BACKGROUND OF THE INVENTION
Stroke remains the third most common cause of death in the industrial world, ranking behind ischemic heart disease and cancer. Strokes are responsible for about 300,000 deaths annually in the United States and about 11,000 deaths annually in Austria. Strokes are also a leading cause of hospital admissions and long-term disabilities. Accordingly, the socioeconomic impact of stroke and its attendant burden on society is practically immeasurable.
"Stroke" is defined by the World Health Organization as a rapidly developing clinical sign of focal or global disturbance of cerebral function with symptoms lasting at least 24 hours. Strokes are also implicated in deaths where there is no apparent cause other than an effect of vascular origin.
Strokes are typically caused by blockages or occlusions of the blood vessels to the brain or within the brain. With complete occlusion, arrest of cerebral circulation causes cessation of neuronal electrical activity within seconds. Within a few minutes after the deterioration of the energy state and ion homeostasis, depletion of high energy phosphates, membrane ion pump failure, efflux of cellular potassium, influx of sodium chloride and water, and membrane depolarization occur. If the occlusion persists for more than five to ten minutes, irreversible damage results. With incomplete ischemia, however, the outcome is difficult to evaluate and depends largely on residual perfusion and the availability of oxygen. After a thrombotic occlusion of a cerebral vessel, ischemia is rarely total. Some residual perfusion usually persists in the ischemic area, depending on collateral blood flow and local perfusion pressure.
Cerebral blood flow can compensate for drops in mean arterial blood pressure from 90 to 60 mm Hg by autoregulation. This phenomenon involves dilatation of downstream resistant vessels. Below the lower level of autoregulation (about 60 mm Hg), vasodilatation is inadequate and the cerebral blood flow falls. The brain, however, has perfusion reserves that can compensate for the fall in cerebral blood fall. This reserve exists because under normal conditions only about 35% of the oxygen delivered by the blood is extracted. Therefore, increased oxygen extraction can take place, provided that normoxia and normocapnea exist. When distal blood pressure falls below approximately 30 mm Hg, the two compensatory mechanisms (autoregulation and perfusion reserve) are inadequate to prevent failure of oxygen delivery.
As flow drops below the ischemic threshold of 23 ml/100 g/minute, symptoms of tissue hypoxia develop. Severe ischemia may be lethal. When the ischemia is moderate, it will result in "penumbra." In the neurological context, penumbra refers to a zone of brain tissue with moderate ischemia and paralyzed neuronal function, which is reversible with restoration of adequate perfusion. The penumbra forms a zone of collaterally perfused tissue surrounding a core of severe ischemia in which an infarct has developed. In other words, the penumbra is the tissue area that can be saved, and is essentially in a state between life and death.
When a clot is degraded and the blood flow to the penumbra is restored, a phenomenon known as reperfusion injury can occur. Portions of the injured tissue in the penumbra can be killed or further injured by the re-entry of oxygen or other substances into the area affected by the ischemia. In view of this phenomenon, the extent of tissue damage resulting from ischemia is determined both by the time required to achieve opening of an occluded vessel and by the series of reactions that follow as a result of reperfusion and the re-entry of oxygen to the affected tissue.
Although an ischemic event can occur anywhere in the vascular system, the carotid artery bifurcation and the origin of the internal carotid artery are the most frequent sites for thrombotic occlusions of cerebral blood vessels, which result in cerebral ischemia. The symptoms of reduced blood flow due to stenosis or thrombosis are similar to those caused by middle cerebral artery disease. Flow through the ophthalmic artery is often affected sufficiently to produce amaurosis fugax or transient monocular blindness. Severe bilateral internal carotid artery stenosis may result in cerebral hemispheric hypoperfusion. This manifests with acute headache ipsilateral to the acutely ischemic hemisphere. Occlusions or decrease of the blood flow with resulting ischemia of one anterior cerebral artery distal to the anterior communicating artery produces motor and cortical sensory symptoms in the contralateral leg and, less often, proximal arm. Other manifestations of occlusions or underperfusion of the anterior cerebral artery include gait ataxia and sometimes urinary incontinence due to damage to the parasagittal frontal lobe. Language disturbances manifested as decrease spontaneous speech may accompany generalized depression of psychomotor activity.
Most ischemic strokes involve portions or all of the territory of the middle cerebral artery with emboli from the heart or extracranial carotid arteries accounting for most cases. Emboli may occlude the main stem of the middle cerebral artery, but more frequently produce distal occlusion of either the superior or the inferior branch. Occlusions of the superior branch cause weakness and sensory loss that are greatest in the face and arm. Occlusions of the posterior cerebral artery distal to its penetrating branches cause complete contralateral loss of vision. Difficulty in reading (dyslexia) and in performing calculations (dyscalculia) may follow ischemia of the dominant posterior cerebral artery. Proximal occlusion of the posterior cerebral artery causes ischemia of the branches penetrating to calamic and limbic structures. The clinical results are hemisensory disturbances that may chronically change to intractable pain of the defective site (thalamic pain).
A significant event in cerebral ischemia is known as the transient ischemic attack ("TIA"). A TIA is defined as a neurologic deficit with a duration of less than 24 hours. The TIA is an important sign of a ischemic development that may lead to cerebral infarction. Presently, no ideal treatment for TIA exists, and there are no generally accepted guidelines as to whether medical or surgical procedures should be carried out in order to reduce the incidence of stroke in subjects with TIA.
The etiology of TIA involves hemodynamic events and thromboembolic mechanisms. Because most TIAs resolve within one hour, a deficit that lasts longer is often classified as presumptive stroke and is, accordingly, associated with permanent brain injury. Therefore, computed tomographic brain scans are used to search for cerebral infarction in areas affected by TIAs lasting longer than several hours. In sum, the relevant clinical distinction between a TIA and a stroke is whether the ischemia has caused brain damage, which is typically classified as infarction or ischemic necrosis. Subjects with deteriorating clinical signs might have stroke in evolution or are classified as having progressive stroke. In this clinical setting, clot propagation is possibly an important factor in disease progression.
There are a myriad of other diseases caused by or associated with ischemia. Vertebrobasilar ischemia is the result of the occlusion of the vertebral artery. Occlusion of the vertebral artery and interference with flow through the ipsilateral posterior inferior cerebellar artery causes lateral medullary syndrome, which has a symptomology including vertigo, nausea, vomiting nystagmus, ipsilateral ataxia and ipsilateral Herner's syndrome. Vertebrobasilar ischemia often produces multifocal lesions scattered on both sides of the brain stem along a considerable length. Except for cerebellar infarction and the lateral medullary syndrome, the clinical syndromes of discrete lesions are thus seldom seen in pure form. Vertebrobasilar ischemia manifests with various combinations of symptoms such as dizziness, usually vertigo, diplopia, facial weakness, ataxia and long tract signs.
A basilar artery occlusion produces massive deficits. One of these deficits is known as the "locked in state." In this condition, paralysis of the limbs and most of the bulbar muscle leaves the subject only able to communicate by moving the eyes or eyelids in a type of code. Occlusion of the basilar apex or top of the basilar is usually caused by emboli that lodge at the junction between the basilar artery and the two posterior cerebral arteries. The condition produces an initial reduction in arousal followed by blindness and amnesia due to an interruption of flow into the posterior cerebral arteries as well as abnormalities of vertical gaze and pupillary reactivity due to tegmental damage.
Venous occlusion can cause massive damage and death. This disease is less common than arterial cerebral vascular disease. As with ischemic stroke from arterial disease, the primary mechanism of brain damage is the reduction in capillary blood flow, in this instance because of increased outflow resistance from the blocked veins. Back transmission of high pressure into the capillary bed usually results in early brain swelling from edema and hemorrhagic infarction in subcortical white matter. The most dangerous form of venous disease arises when the superior sagittal sinus is occluded. Venous occlusion occurs in association with coagulation disorders, often in the purpural period, or in subjects with disseminated cancers or contagious diseases. If anticoagulant therapy is not initiated, superior sagittal sinus occlusion has a mortality rate of 25-40%.
Brief diffuse cerebral ischemia can cause syncope without any permanent sequelae. Prolonged diffuse ischemia in other organs has devastating consequences. The most common cause is a cardiac asystole or other cardiopulmonary failures, including infarction. Aortic dissection and global hypoxia or carbon monoxide poisoning can cause similar pictures. Diffuse hypoxia/ischemia typically kills neurons in the hippocampus, cerebellar Purkinje cells, striatum or cortical layers. Clinically, such a diffuse hypoxia/ischemia results in unconsciousness and in coma, followed in many instances by a chronic vegetative state. If the subject does not regain consciousness within a few days, the prognosis for the return of independent brain functions becomes very poor.
Hyperviscosity syndrome is another disease related to blood flow and ischemia. Cerebral blood flow is inversely related to blood viscosity. The latter is directly proportional to the number of circulating red and white cells, the aggregation state, the number of platelets and the plasma protein concentration. Blood flow is inversely proportional to the deformability of erythrocytes and blood velocity (shear rate). Subjects with hyperviscosity syndrome can present either with focal neurologic dysfunction or with diffuse or multifocus signs or symptoms including headache, visual disturbances, cognitive impairments or seizures.
There are a number of substances involved in clot formation and lysis. Plasminogen, also known as gluplasminogen, and plasmin are two of the primary substances involved in lysis.
Plasminogen is a protein, composed of 791 amino acids, that circulates in human plasma at a concentration of about 200 μg/ml. Plasminogen is the zymogen form of the fibrinolytic enzyme, plasmin, which has broad substrate specificity and is ultimately responsible for degrading blood clots. For the most part, fibrin proteolysis is mediated by the generation of plasmin within a fibrin clot from the plasminogen trapped within the clot. Fredenburgh & Nesheim, J. Biol. Chem. 267: 26150-56 (1992).
Plasminogen has five kringle domains within its amino-terminal heavy chain region that exhibit lysine-binding sites for recognition of lysine residues in fibrin. Plasminogen-plasmin conversion, both within a clot and at its surface, is facilitated by the affinity of tissue plasminogen activator ("t-PA") for fibrin, which results in a fibrin-dependent t-PA-induced plasminogen activation. Fredenburgh, loc. cit.
Once initiated, fibrinolysis results in several positive feedback reactions. For instance, plasmin-catalyzed cleavage of fibrin generates carboxy-terminal lysine residues, which in turn provide additional binding sites for both t-PA and plasminogen. This also facilitates plasmin-catalyzed conversion of glu-plasminogen to lys-plasminogen by a specific cleavage, which is a pre-activation step. Shih & Hajjar, P.S.E.B.M. 202: 258-64 (1993). In the literature, the term "lys-plasminogen" refers to forms of plasminogen where the N-terminal amino acid is lysine, valine or methionine. Nieuwenhuizen et al., Eur. J. Biochem. 174: 163-69 (1988). The conversion activity reflects a positive feedback reaction, because lys-plasminogen is a considerably better substrate than glu-plasminogen for both t-PA and urokinase, which may be caused by the enhanced affinity of lys-plasminogen for fibrin. The ratio of the Kcat/Km for t-PA-catalyzed activation of lys-plasminogen exceeds that of glu-plasminogen by about a factor of ten. Fredenburgh, loc. cit.
Fibrinolysis has been previously shown to be accelerated by the addition of lys-plasminogen in vivo and in vitro. In addition, when the use of exogenous lys-plasminogen was compared to the use of exogenous glu-plasminogen in similar experiments, 0.08 μmol lys-plasminogen produced the same degree of enhanced fibrinolysis as 0.67 μmol glu-plasminogen. Therefore, while both forms of plasminogen shorten the time for fibrinolysis, lys-plasminogen is about eight times more potent in this regard than glu-plasminogen. See Fredenburgh, supra.
Previous studies of lys-plasminogen have not implicated this protein for use in treatment of reperfusion injury. The conventional treatment for reperfusion injury is Flunarizine, which is only effective when administered prophylactically.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a method for treating reperfusion injury to tissue.
It is also an object of the present invention to provide a method for treating ischemia, infarction or brain edema.
It is also another object of the present invention to provide a method for improving the microcirculation.
It is yet another object of the present invention to provide a method for treating the reperfusion injury that follows ischemic events.
It is yet another object of the present invention to provide a method for treating the reperfusion injury that follows ischemic events by administering a pharmaceutical composition comprising plasmin or a plasmin-forming protein, including zymogens and pre-activated zymogens of plasmin.
It is still another object of the present invention to provide a method for treating ischemia and the attendant reperfusion injury resulting from events following ischemia by administering a pharmaceutical composition comprising a plasminogen activator and plasmin or a plasmin-forming protein, as described above.
In accordance with one aspect of the present invention, a method is provided for treating reperfusion injury that comprises administering to a subject a pharmaceutical preparation comprising plasmin or a plasmin-forming protein and a pharmaceutically acceptable carrier. In a preferred embodiment, lys-plasminogen or related compounds are employed. The composition for use in this method may further comprise plasminogen activators such as tissue-type plasminogen activator, urokinase-type activators, pro-urokinase, streptokinase-type activators and plasmin.
Other objects, features and advantages of the present invention will become apparent from the following description and figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 sets forth the scoring system used for evaluation of neurologic defects.
FIG. 2 is a summary of experimental data employing a rat model for evaluating the therapeutic benefits of lys-plasminogen as compared to a control.
FIG. 3 is a graphic representation of the data from a controlled experiment evaluating the effect lys-plasminogen on the brain moisture content (edema) of rats with induced ischemia.
"A" is rats with surgically-induced ischemia receiving 500 U/kg lys-plasminogen i.v. with blood reperfusion; "B" is rats with surgically-induced ischemia receiving 1.0 ml/kg isotonic saline i.v. with blood reperfusion; and "C" is rats having undergone a sham operation receiving 1.0 ml/kg isotonic saline i.v. (ΔAB p<0.001; ΔBC: p<0.001; ΔAC: p<0.05).
FIG. 4 is a graphic representation of the data from an experiment evaluating the effect of buffer on the brain moisture content (edema) of rats with induced ischemia, which serves as an additional control of the experiment of FIG. 3.
"A" is rats with surgically-induced ischemia receiving 1.0 ml/kg buffer i.v. with blood reperfusion (n=7); "B" is rats with surgically-induced ischemia receiving 1.0 ml/kg isotonic saline i.v. with blood reperfusion (n=7); and "C" is rats having undergone a sham operation receiving 1.0 ml/kg isotonic saline i.v. (n=8). (ΔAB n.s.; ΔBC: p<0.01; ΔAC: p<0.01).
FIG. 5 is a graphic representation of the data from a controlled experiment evaluating the effect lys-plasminogen on the neurologic deficits of rats with induced ischemia.
The total score is based on individual ratings for state of consciousness, gait, muscle tone and performance (mean of 3 days per animal). The maximum score is 54 (n=10 per group). "A" is rats with surgically-induced ischemia receiving 500 U/kg/1.0 ml lys-plasminogen i.v. with blood reperfusion; "B" is rats with surgically-induced ischemia receiving 1.0 ml/kg isotonic saline i.v. with blood reperfusion; and "C" is rats having undergone a sham operation receiving 1.0 ml/kg isotonic saline i.v. (ΔAB: p<0.001; ΔBC: p<0.001; ΔAC: p=0.05).
FIG. 6 is a graphic representation of the data from an experiment evaluating the effect of buffer on the neurologic deficits of rats with induced ischemia, which serves as an additional control of the experiment of FIG. 5.
The total score is based on individual ratings for state of consciousness, gait, muscle tone and performance (mean off 3 days per animal). The maximum score is 54 (n=6 per group). "A" is rats with surgically-induced ischemia receiving 1.0 ml/kg1.0 ml buffer i.v. with blood reperfusion; "B" is rats with surgically-induced ischemia receiving 1.0 ml/kg isotonic saline i.v. with blood reperfusion; and "C" is rats having undergone a sham operation receiving 1.0 ml/kg isotonic saline i.v. (ΔAB: n.s; ΔBC: p<0.01; ΔAC: p<0.01).
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The present invention enables treatment of ischemic events, including cerebral ischemia, and reperfusion injury associated with ischemic events. Additionally, the present invention permits the treatment of ischemic events in a manner that avoids or minimizes the adverse effects associated with conventional treatments, such as reperfusion injury. The term "treatment" in its various grammatical forms refers to preventing, alleviating, minimizing or curing maladies or other adverse conditions.
It has been discovered that plasmin and plasmin-forming proteins, a category that includes lys-plasminogen, a pre-activated zymogen of plasmin, can be used, in accordance with the present invention, to attenuate or avoid reperfusion injury following an ischemic event. This beneficial effect can be obtained even when reperfusion already has started.
Lys-plasminogen itself can be employed as a treatment. All forms of lys-plasminogen are considered suitable for use with this invention as long as they retain the ability to affect the benefits described above. Also suitable for use pursuant to the present invention are fragments of lys-plasminogen and variants of lys-plasminogen, such as analogs, derivatives, muteins and mimetics of the natural molecule, that retain the ability to affect the benefits described above.
Fragments of lys-plasminogen refers to portions of the amino acid sequence of the lys-plasminogen polypeptide. These fragments can be generated directly from lys-plasminogen itself by chemical cleavage, by proteolytic enzyme digestion, or by combinations thereof. Additionally, such fragments can be created by recombinant techniques employing genomic or cDNA cloning methods. Furthermore, methods of synthesizing polypeptides directly from amino acid residues also exist. The variants of lys-plasminogen can be produced by these and other methods. Site-specific and region-directed mutagenesis techniques can be employed. See CURRENT PROTOCOLS IN MOLECULAR BIOLOGY vol. 1, ch. 8 (Ausubel et al. eds., J. Wiley & Sons 1989 & Supp. 1990-93); PROTEIN ENGINEERING (Oxender & Fox eds., A. Liss, Inc. 1987). In addition, linker-scanning and PCR-mediated techniques can be employed for mutagenesis. See PCR TECHNOLOGY (Erlich ed., Stockton Press 1989); CURRENT PROTOCOLS IN MOLECULAR BIOLOGY, vols. 1 & 2, supra. Non-peptide compounds that mimic the binding and function of a peptide ("mimetics") can be produced by the approach outlined in Saragovi et al., Science 253:792-95 (1991). Protein sequencing, structure and modeling approaches for use with any of the above techniques are disclosed in PROTEIN ENGINEERING, loc. cit. and CURRENT PROTOCOLS IN MOLECULAR BIOLOGY, vols. 1 & 2, supra.
Once a desired fragment or variant of lys-plasminogen is obtained, techniques described herein can be employed for determining whether the fragment or variant is effective for the above therapies, such as treatment of reperfusion injury and, if so, identifying an appropriate dosage range. The rat stroke model described in the example below is a simple and cost-efficient way of performing this testing in vivo.
The present invention also contemplates the use of progenitors of lys-plasminogen, that is, precursors of lys-plasminogen as well as substances that act on a lys-plasminogen precursor to generate lys-plasminogen. Illustrative of lys-plasminogen progenitors is glu-plasminogen, which is cleaved by an appropriate protease to generate lys-plasminogen. A substance effecting such a proteolytic cleavage is plasmin, the use of which falls within the scope of this invention as stated above. These rat stroke model described below is also useful for evaluating the effectiveness of lys-plasminogen progenitors.
Lys-plasminogen can be obtained by proteolytic cleavage of glu-plasminogen to remove amino acid sequences from glu-plasminogen. Methods of producing lys-plasminogen are described in greater detail in European Application 0 353 218. See also Neuwenhuizen, supra.
An example presented below demonstrates a previously unknown effect of lys-plasminogen which implicates its efficacy, and that of the lys-plasminogen variants and progenitors as well as plasmin and plasmin-forming proteins, in the treatment of reperfusion injury. Until now, lys-plasminogen was only known to function in fibrinolysis. It was not expected that plasmin or any plasmin-forming protein, such as lys-plasminogen, would be able to overcome the blood-brain barrier, which has been presumed to be necessary to be effective at the site of a cerebral ischemic event.
Other uses for lys-plasminogen exist as well. Lys-plasminogen is helpful in treating subjects after cardiac arrest. Lys-plasminogen administration may prevent the ischemic damage to neural cells. Lys-plasminogen can also be used in the treatment of total body ischemia (shock), ischemia of the bowels and lower extremities and for the preservation of organs for transplant by preventing ischemia.
Administration methods include those used for clotlysis treatments, typically intravenous routes. The dosage of Lys-plasminogen to be employed with this invention should be based on the weight of the subject and administered at a dosage of about 10 to 1000 caseinolytic units ("CU")/kg. Preferably, the dosage should be about 100 to 600 CU/kg, and more preferably the dosage should be about 500 CU/kg. The lys-plasminogen can be administered during blood reperfusion, which would occur when lys-plasminogen is administered along with conventional clot lysis treatments such as t-pa. Additionally, the beneficial effect of the lys-plasminogen can still be obtained when it is administered after reperfusion has already begun. Preferably, the lys-plasminogen should be administered before or within about 30 minutes after reperfusion has begun. Lys-plasminogen variants and progenitors should be administered in dosages that yield the same effect as the dosage ranges discussed above.
A treatment in accordance with the present invention can be effected advantageously via administration of the above-described substances in the form of injectable compositions. A typical composition for such purpose comprises a pharmaceutically acceptable carrier. An exemplary composition in this context is a lys-plasminogen buffer vehicle (9 g/L NaCl, 1 g/l Na 3 citrate •2H 2 O, 3 g/l L-lysine, 6 g/l NaH 2 PO 4 •2H 2 O and 40,000 KIU/l aprotonin). Pharmaceutically acceptable carriers in this context include other aqueous solutions, non-toxic excipients, including salts, preservatives, buffers and the like, as described in REMINGTON'S PHARMACEUTICAL SCIENCES, 15th Ed. Easton: Mack Publishing Co. pp 1405-1412 and 1461-1487 (1975) and in THE NATIONAL FORMULARY XIV., 14th Ed. Washington: American Pharmaceutical Association (1975), the contents of which are hereby incorporated by reference. Examples of non-aqueous solvents are propylene glycol, polyethylene glycol, vegetable oil and injectable organic esters such as ethyloleate. Aqueous carriers include water, alcoholic/aqueous solutions, saline solutions, parenteral vehicles such as sodium chloride, Ringer's dextrose, etc. Intravenous vehicles include fluid and nutrient replenishers. Preservatives include antimicrobials, anti-oxidants, chelating agents and inert gases. The pH and exact concentration of the various components of the binding composition are adjusted according to routine skills in the art. See GOODMAN AND GILMAN'S THE PHARMACOLOGICAL BASIS FOR THERAPEUTICS (7th ed.).
EXAMPLE
Effect of Lys-Plasminogen on the Sequelae of Cerebral Ischemia in Rats
In this experimental series,-the effects of lys-plasminogen on the sequelae of experimentally induced ischemia in rats was evaluated. Two different approaches were employed to assess the neurologic consequences of ischemia. Ischemia was induced in rats as described below.
First, male Sprague-Dawley rats (weight 300-400 g) are anesthetized with 350 mg/kg choral hydrate i.p., and a catheter was then inserted into the jugular vein. Five milliliters of blood was withdrawn through the jugular catheter (100 IU heparin in the syringe) in order to reduce mean arterial blood pressure to 50 mm Hg. The prepared carotid arteries are exposed and clamped simultaneously with the blood withdrawal. The clamps are removed after a period of 30 minutes, and the withdrawn blood is reinfused (reperfusion). Fibrin sealant (Tisseel®) is applied to the wounds. The animals remain under anesthesia for a total of 24 hours (23.5 hours after reperfusion). After regaining consciousness, each animal undergoes one of the following procedures:
Assessment of brain edema:
Animals are maintained at constant body temperatures for a total of 24 hours, sacrificed with ether and the brains removed. Assessment of brain edema was performed using modifications of methods published for other species. Oh & Betz, Stroke 22: 915-21 (1991).
Moisture content, which is an excellent parameter for assessing ischemia/reperfusion-induced edema of the brain, is determined as follows: Both hemispheres are weighed, dried for 17 hours at 200° C., and reweighed. Moisture content is was calculated in percent of total moist weight according to the following formula: ##EQU1## Assessment of neurologic deficits:
Animals were assessed for neurologic deficits on the first, second and third post-operative days. Wauquier et al., Neuropharmacology 28: 837-46 (1989). State of consciousness, gait, muscle tone, performance on an overhead ladder tilted at 45°, and performance on a vertically mounted rotating disk were evaluated on the basis of the scoring system shown in FIG. 1. A cumulative score for the three days is calculated (maximum score=54).
Lys-plasminogen (IMMUNO AG) was administered intravenously by means of catheter into either the jugular or tail vein. These administrations were performed in increasing concentrations at various time points. Ischemic animals treated with isotonic saline served as positive controls, while animals subjected to a sham operation and treated with isotonic saline served as negative controls.
The above-described lys-plasminogen buffer was tested using each of these procedures in separate experiments. A summary of dosage, administration schedule, experimental procedures and results is set forth in FIG. 2.
The results for 500 CU/kg lys-plasminogen (and the buffer employed as a control) are shown in FIGS. 3 and 4 for edema and FIGS. 5 and 6 for neurologic deficits. Significance values were based on t-tests for edema and the Kruskal-Wallis test assuming a chi-square distribution for neurologic deficits.
A dose of 500 CU/kg of lys-plasminogen showed a significant protective effect on the sequence of experimentally induced cerebral ischemia in rats. The schedule of administration did not play an essential role. Notably, the lys-plasminogen still exerted a protective effect even when it was administered 30 minutes after the beginning of reperfusion. This contrasts with results obtained for the standard therapeutic measure flunarizine, which is a calcium antagonist used in clinical practice. Flunarizine (0.63 mg/kg given intravenously) was effective when administered in the reperfused blood, but had no effect when administered 30 minutes after reperfusion (data not shown).
Lys-plasminogen (500 CU/kg) was capable of reversing the effects of cerebral ischemia as assessed on the basis of brain edema and neurologic deficits in a rat model of experimental ischemia. The buffer used in the lys-plasminogen preparation had no effect. In contrast to a standard therapeutic measure (flunarizine), lys-plasminogen was effective even when administered 30 minutes after reperfusion.
It is to be understood that the description, figures and specific examples, while indicating preferred embodiments of the invention are given by way of illustration and are not intended to limit the present invention. Various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from the discussion and disclosure contained herein. | 4y
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REFERENCE TO RELATED APPLICATION
The present application claims priority from U.S. Provisional Application No. 61/216,385, filed May 18, 2009.
BACKGROUND OF THE INVENTION
The present invention relates generally to bicycle shifters, and more particularly, is directed to a shift lever arrangement for a bicycle using a single lever movable along two orthogonal axes for shifting in different directions.
Conventionally, shifters for bicycles have been mounted on the handlebar, separate and apart from the brake levers. Generally, there is single lever that is rotatable in one direction for upshifting and rotatable in the opposite direction for downshifting.
It is, however, to provide different tactile sensations when shifting in the different directions. In this regard, U.S. Pat. No. 5,921,138 to Kojima et al discloses a first lever that is linearly movable for shifting in a first direction and a separate second lever that is pivotally movable in a second different direction for shifting in an opposite direction. However, this requires two different levers, even though the tactile sensations are different.
U.S. Pat. No. 7,527,137 issued May 5, 2009 to the same inventor herein, discloses a single lever that effects a braking operation and a gear shifting operation. A rod moves inside the shift lever in the linear direction, but also requires pivoting movement thereafter of the shift lever, in order to effect a shifting operation. Specifically, to provide a reverse shifting operation, a push button is depressed. As a result, a caroming surface in the shift lever engages a roller wheel to push a plunger rod in the shift lever up against the force of a linear coil spring associated therewith. The flat upper surface of the plunger rod engages the free engagement end of a cable carrier pawl 100 . Then, with the push button still depressed, the shift/brake lever is again pivoted about its pivot pin to effect the reverse shifting operation. Thus, this patent requires linear movement of a rod inside of the pivot lever, and also, pivoting movement of the lever thereafter. Further, this arrangement is greatly complicated because it also requires that the single lever be used for a braking operation as well.
The inventor herein has also invented an arrangement which is the subject matter of copending U.S. patent application Ser. No. 11/434,324, filed May 15, 2006 in which a single lever is used for a braking operation as well as gear shifting in both directions. In this invention, the single lever is pivoted in a first direction for performing a braking operation, pivoted in a second direction for performing a first gear shifting operation, and movable only in a linear direction in the longitudinal direction of the shift lever for performing a second opposite gear shifting operation without pivoting of the single lever.
This latter arrangement, however, becomes relatively complicated because of the inclusion of the braking arrangement with the single lever.
It is therefore desirable to provide a single lever that is used for shifting in opposite directions with different tactile sensations, but which is not used for braking.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a shift lever arrangement for a bicycle that overcomes the problems with the aforementioned prior art.
It is another object of the present invention to provide a shift lever arrangement for a bicycle that uses a single lever for shifting in both directions, without providing any braking operation.
It is still another object of the present invention to provide a shift lever arrangement for a bicycle in which the lever moves in pivoting motion for gear switching in one direction, and a linear motion for, gear switching in the opposite direction.
It is yet another object of the present invention to provide a shift lever arrangement for a bicycle that includes a shift control arrangement that uses common elements therein that interact with the shift lever during shifting in both directions.
It is a further object of the present invention to provide a shift lever arrangement for a bicycle that is compact, economical and easy to use.
In accordance with an aspect of the present invention, a gear shift arrangement is provided for a bicycle that is separate and distinct from a brake lever of the bicycle, the bicycle having a derailleur and a derailleur cable associated therewith. The gear shift arrangement includes a single lever adapted to only perform a shifting operation of gears of the bicycle, a housing, a mounting arrangement in the housing for mounting the single lever for movement in a first pivoting direction and for movement in a second substantially linear direction, and a shift control mechanism in the housing for controlling shifting of the gears of the bicycle in a first shifting direction upon movement of the single lever in the first pivoting direction and for controlling shifting of gears of the bicycle in a second, opposite shifting direction upon movement of the single lever in the second substantially linear direction.
The shift control mechanism includes a pulley rotatably mounted in the housing and around which the cable extends, and an actuating arrangement connected between the mounting arrangement and the pulley for controlling rotation of the pulley to either pull or release the cable in dependence upon movement of the shift lever. The pulley includes a plurality of sets of gear teeth therearound, and the actuating arrangement includes a plurality of pawls for engaging the gear teeth in dependence upon movement of the shift lever.
For pulling the cable, the actuating arrangement includes a rotatable element rotatably mounted in the housing and adapted to be rotated from an initial position to a first rotated position by the mounting arrangement upon movement of the single lever in the first pivoting direction. An advance pawl as one of the pawls is pivotally mounted on the rotatable element, and an advance pawl spring biases the advance pawl into engagement with a first the set of gear teeth on the pulley to rotate the pulley to the first rotated position to pull the cable, wherein the advance pawl is configured so that the advance pawl is adapted to engage and rotate the pulley only in a direction to pull the cable.
The actuating arrangement also includes a rotatable element spring for rotationally biasing the rotatable element to the initial position. A main pawl as one of the pawls is pivotally mounted to the housing for holding the pulley in the first rotated position when the shift lever is released and when the rotatable element and the advance pawl are rotated back to the initial position by the rotatable element spring, and a main pawl spring biases the main pawl into engagement with a second the set of gear teeth on the pulley.
The mounting arrangement includes a slide mounted in the housing and connected with the shift lever for substantially linear sliding movement and rotatable movement with the shift lever. There is also a limiting arrangement for preventing the substantially linear sliding movement of the slide upon movement of the single lever in the first pivoting direction.
The slide is adapted to be moved in the housing for substantially linear sliding movement from the initial position to a first linear slid position, upon movement of the single lever in the substantially linear direction. The actuating arrangement further includes a substantially linear biasing arrangement for biasing the slide to the initial position. A hold pawl as one of the pawls is pivotally mounted to the housing for permitting an incremental rotational movement of the pulley, and a pawl biasing arrangement on the slide biases the hold pawl into engagement with a third the set of gear teeth on the pulley upon movement of the single lever in the substantially linear direction to the first linear slid position in order to effect the incremental rotational movement of the pulley.
The pawl biasing arrangement includes a raised abutment that engages an end of the hold pawl upon movement of the single lever and slide in the substantially linear direction to the first linear slid position to bias the hold pawl into engagement with the third the set of gear teeth and to bias the main pawl out of engagement with the second set of gear teeth. The third set of gear teeth have a pitch greater than a width of the hold pawl to permit an incremental rotation of the pulley when the hold pawl is initially engaged therein, in a direction to release the cable. Upon return of the shift lever and slide to the initial position, the hold pawl is no longer biased into engagement with the third set of gear teeth by the pawl biasing arrangement, and the main pawl is biased into engagement by the main pawl spring with the second set of gear teeth to hold the pulley in an incrementally rotated cable release position.
The actuating arrangement also includes a holding arrangement for holding the advance pawl out of engagement with the first gear teeth during movement of the single lever in the substantially linear direction.
There is also a limiting arrangement for preventing rotational movement of the rotatable element upon movement of the single lever in the substantially linear direction.
The above and other objects, features and advantages of the invention will become readily apparent from the following detailed description thereof which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one side of the shifter according to the present invention mounted on a handlebar;
FIG. 2 is a perspective view of the other one side of the shifter according to the present invention mounted on a handlebar;
FIG. 3 is a perspective view of FIG. 1 with the second half housing shell removed;
FIG. 4 is a perspective view of FIG. 1 with the second half housing shell, triple gear pulley and post sleeve removed;
FIG. 5 is an exploded view of the shifter according to the present invention;
FIG. 6 is an outer perspective view of the first half housing shell;
FIG. 7 is an inner perspective view of the first half housing shell;
FIG. 8 is an inner plan view of the first half housing shell;
FIG. 9 is a top outer perspective view of the second half housing shell;
FIG. 10 is a bottom outer perspective view of the second half housing shell;
FIG. 11 is a left side outer perspective view of the second half housing shell;
FIG. 12 is a left side inner perspective view of the second half housing shell;
FIG. 13 is a right side inner perspective view of the second half housing shell;
FIG. 14 is a plan view of the inner facing side of the second half housing shell;
FIG. 15 is an outside perspective view of the slide;
FIG. 16 is an inside perspective view of the slide;
FIG. 17 is an outside plan view of FIG. 13 ;
FIG. 18 is an inside plan view of FIG. 14 ;
FIG. 19 is a perspective view of the shift lever;
FIG. 20 is a perspective view of the inner facing side of the post sleeve;
FIG. 21 is a perspective view of the outer facing side of the post sleeve;
FIG. 22 is a perspective view of the shift lever return spring;
FIG. 23 is a perspective view of the inner facing side of the triple gear pulley;
FIG. 24 is a perspective view of the outer facing side of the triple gear pulley;
FIG. 25 is an elevational view of the inner facing side of the triple gear pulley;
FIG. 26 is an elevational view of the outer facing side of the triple gear pulley;
FIG. 27 is an elevational view of the right side of the triple gear pulley;
FIG. 28 is an elevational view of the left side of the triple gear pulley;
FIG. 29 is a perspective view of the gear return spring;
FIG. 30 is a perspective view of the inner facing side of the pawl flange;
FIG. 31 is a perspective view of the outer facing side of the pawl flange;
FIG. 32 is a perspective view of the inner facing side of the hold pawl;
FIG. 33 is a perspective view of the outer facing side of the hold pawl;
FIG. 34 is a perspective view of the main pawl;
FIG. 35 is a perspective view of the main pawl spring;
FIG. 36 is a perspective view of the inner facing side of the advance pawl;
FIG. 37 is a perspective view of the outer facing side of the advance pawl;
FIG. 38 is a perspective view of the advance pawl spring;
FIG. 39 is a perspective view of the advance pawl retaining ring;
FIG. 40 is a perspective view of the return spring spacer;
FIG. 41 is a perspective view of the shifter according to the present invention during a gear shifting operation in a first direction; and
FIG. 42 is a perspective view of the shifter according to the present invention during a gear shifting operation in a first direction.
DETAILED DESCRIPTION
Referring to the drawings in detail, and initially to FIGS. 1-5 , a shift arrangement 10 for a bicycle according to the present invention, includes a housing 16 to be secured to a handlebar 12 of a bicycle by a clamp 14 .
For discussion hereafter, reference to an inner facing side or inner facing surface will refer to the side or surface facing the rider, and reference to an outer facing side or outer facing surface will refer to the side or surface facing away from the rider.
Specifically, housing 16 includes a first half housing shell 18 and a second half housing shell 20 secured to first half housing shell 18 so as to encase the assembly for effecting gear shifting.
As shown best in FIGS. 5-8 , first half housing shell 18 includes a planar circular outer wall 22 having an annular inturned flange 24 at the periphery thereof. Three equiangularly spaced ears 26 extend outwardly from annular inturned flange 24 , each ear 26 having a threaded opening 28 therein facing second half housing shell 20 . A central opening 30 is provided in planar outer wall 22 , with central opening 30 having a slightly oval or oblong configuration. Two raised stops 32 and 34 extend inwardly from planar outer wall 22 at the edge of central opening 30 , with stops 32 and 34 being about 100 degrees apart around central opening 30 . An arcuate guide wall 36 is also provided on the inside surface of planar outer wall 22 between stops 32 and 34 and spaced away from central opening 30 . A gap 35 is provided between the end of arcuate guide wall 36 and stop 34 , the purpose for which will become apparent from the discussion hereafter.
As best shown in FIGS. 5 and 9 - 14 , second half housing shell 20 also includes a planar substantially circular outer wall 40 having an annular inturned flange 42 at the periphery thereof. An annular wall 44 extends outwardly from the periphery of annular inturned flange 42 , with three equiangularly spaced ears 46 extending outwardly from annular wall 44 . Each ear 46 has a through bore 48 therein. In this regard, bolts 50 ( FIG. 1 ) extend into through bores 48 and are threadedly received in threaded openings 28 to secure second half housing shell 20 to first half housing shell 18 , with annular wall 44 seating on inturned flange 24 .
Annular inturned flange 42 includes an outwardly extending nose 52 of a generally frusto-conical configuration with a slight taper extending therefrom, and with a central bore 54 extending therethrough in communication with the interior of housing 16 . As shown in FIG. 1 , nose 52 cooperates with cable adjust collar 56 , with the derailleur cable 57 extending through cable adjust collar 56 and nose 52 into the interior of housing 16 , as will be explained in greater detail hereafter.
A cylindrical boss 58 extends inwardly from the center of the inner facing surface of circular outer wall 40 and has a substantially trapezoidal shaped upper end 60 with the longer side of substantially trapezoidal shaped upper end 60 being rounded, although the present invention is not limited to this shape. A central opening 61 is provided through cylindrical boss 58 and substantially trapezoidal shaped upper end 60 , and smaller offset openings 63 and 65 are provided in substantially trapezoidal shaped upper end 60 . A slight depression 62 is formed near the periphery of circular outer wall 40 at the inner facing surface thereof at a position approximately 70 degrees offset from nose 52 in the counterclockwise direction of FIG. 14 , with a through opening 64 formed in the center of slight depression 62 . A raised projection 66 is formed to one side of depression 62 in the counterclockwise direction of FIG. 14 , at the inner facing surface of circular outer wall 40 and at the inner facing surface of annular inturned flange 42 , and includes a threaded opening 68 therein. Raised projection 66 includes a triangular shaped projection 70 extending inwardly from annular inturned flange 42 . A substantially triangular recess 72 is formed in the inner facing surface of annular inturned flange 42 directly behind slight depression 62 , and extends upwardly to annular wall 44 . A circular opening 74 extends into the bottom wall of recess 72 . A U-shaped recess 76 is formed in the inner facing surface of annular inturned flange 42 to the opposite side of slight depression in the clockwise direction of FIG. 14 , and extends the entire height thereof. Lastly, a through opening 78 extends through annular inturned flange 42 , substantially diametrically opposite U-shaped recess 76 .
Referring now to FIGS. 4 , 5 and 15 - 18 , a slide or mounting element 80 as part of a mounting arrangement 79 for the shift lever to be discussed hereafter, is slidably mounted to planar circular outer wall 22 of first half housing shell 18 . Specifically, slide 80 includes a circular disc 82 having a circular boss 84 extending from the center of the outer facing surface of circular disc 82 . Boss 84 is cut away to define a slightly raised pedestal 86 and raised walls 87 a and 87 b extending upwardly therefrom with a generally outer circular footprint. Raised walls 87 a and 87 b define a large rectangular open area 88 between raised walls 87 a and 87 b , which is in communication with a small rectangular open area 90 between raised walls 87 a and 87 b through an intermediary curved open area 92 between raised walls 87 a and 87 b , all above slightly raised pedestal 86 . A central threaded opening 94 is provided on the outer facing surface of circular disc 82 at the center thereof. A cylindrical projection 96 is provided on the outer facing surface of circular disc 82 , adjacent to small rectangular open area 90 and at a lower height than slightly raised pedestal 86 . An annular advance roller 97 ( FIG. 17 ) is rotatably mounted on cylindrical projection 96 , and is adapted to fit through gap 35 .
The opposite inner facing surface of slide 80 includes an elongated recess 98 having a flat end 100 at one end thereof and extends in the same lengthwise direction as large rectangular open area 88 and centered therewith. A triangular recess 102 is provided to one side of elongated recess 98 and includes a guide wall 103 as will be discussed in greater detail hereafter. A further recess 104 is provided on the opposite side of elongated recess 98 for the purpose of reducing material. In addition, a slightly arcuate raised wall 106 extends upwardly from the inner facing surface of slide 80 at a position generally inline with elongated recess 98 but near the opposite periphery of circular disc 82 . A further slightly arcuate raised wall 108 of lesser dimensions than slightly arcuate raised wall 106 extends upwardly from one outer circumferential corner of slightly arcuate raised wall 106 .
Slide 80 is slidably mounted to planar circular outer wall 22 of first half housing shell 18 such that the outer facing surface of slide 80 rests against the inner facing surface of first half housing shell 18 and such that raised walls 87 a and 87 b extend through central opening 30 .
A shift lever 110 , as shown in FIGS. 5 and 19 , is attached to the outer facing surface of slide 80 , to the outside of first half housing shell 18 . Specifically, lever 110 has a generally human leg shaped appearance, with an upper leg section 112 connected to a lower leg section 114 at an angle of about 140 degrees through a knee section 116 , with the free end of lower leg section 114 including a foot 118 extending approximately at a right angle from lower leg section 114 . Upper leg section 112 includes a main body 120 having dimensions corresponding to the dimensions of large rectangular open area 88 of slide 80 and fits therein. The free end of upper leg section 112 tapers down through an arcuate reducing section 122 to a reduced dimension rectangular parallelepiped section 124 . Arcuate reducing section 122 has dimensions corresponding to the dimensions of intermediary curved open area 92 of slide 80 and fits therein, and rectangular parallelepiped section 124 has dimensions corresponding to small rectangular open area 90 and fits thereon. In this position, a through bore 126 in main body 120 is in coaxial alignment with central opening 94 of slide 80 . A rivet, bolt or the like (not shown) extends through bore 126 and central opening 94 to fixedly secure shift lever 110 to slide 80 .
It will therefore be appreciated that rotation of shift lever 110 around the axis of through bore 126 results in corresponding rotation of slide 80 relative to first half housing shell 18 . In addition, since raised walls 87 a and 87 b have a generally outer circular footprint, and since central opening 30 of first half housing shell 18 has a slightly oval or oblong configuration, raised walls 87 a and 87 b can slide within central opening 30 . Thus, when shift lever 110 is pushed by the user in an axial direction thereof, from the outer surface of foot 118 , as shown in FIG. 42 , raised walls 87 a and 87 b slide within central opening 30 .
Referring now to FIGS. 5 , 20 and 21 , a post sleeve 130 as a rotatable element of an actuating arrangement is provided in the housing 16 against the inner facing surface of slide 80 . Specifically, post sleeve 130 includes a thin generally circular plate 132 having two ears 134 and 136 extending outwardly in the plane of plate 132 and separated by an angle of about 100 degrees. A boss 138 is provided at the outer end of one ear 134 and has a post 140 extending therefrom at right angles to the plane of plate 132 , while a post 142 extends from the other ear 136 on the opposite side of plate 132 . An annular groove 141 is provided around post 140 near the free end thereof. A small opening 143 is provided on the opposite surface of ear 136 . In addition, plate 132 includes a central through bore 144 .
A center shaft 146 as part of the mounting arrangement 79 is fixed in central opening 61 of cylindrical boss 58 and extends through bore 144 . The free end of center shaft 146 has a post sleeve roller 145 ( FIG. 4 ) thereon which slidably fits within elongated recess 98 and which permits center shaft 146 to rotate therein. A compression spring 147 ( FIGS. 4 and 16 ) or other suitable spring member is fit within elongated recess 98 between flat end 100 thereof and post sleeve roller 145 to normally bias post sleeve roller 145 away from flat end 100 .
Post sleeve 130 is rotatably mounted on center shaft 146 such that post 142 extends within triangular recess 102 of slide 80 . An annular advance roller 148 is rotatably mounted on post 142 and is adapted to be guided along guide wall 103 of slide 80 , as will be discussed hereafter, during sliding movement of raised walls 87 a and 87 b within central opening 30 . Advance roller 148 is shown disengaged from post 142 in FIG. 3 merely for better illustration purposes.
As shown in FIGS. 5 and 22 , a coiled torsion shift lever return spring 131 is mounted against the inner facing surface of post sleeve 130 . The inner end of shift lever return spring 131 is bent to form a bent spring projection 133 that is fixed in offset opening 63 , while the outer end of shift lever return spring 131 is bent to form a bent spring projection 135 that is fixed in small opening 143 provided in ear 136 of post sleeve 130 . In this manner, shift lever return spring 131 functions to normally bias post sleeve 130 in the clockwise direction of FIG. 3 . As a result, annular roller 148 mounted on post 142 functions to rotate slide 80 and shift lever 110 therewith.
As shown best in FIGS. 3 , 5 and 23 - 28 , a triple gear pulley 150 is rotatably mounted on cylindrical boss 58 of second half housing shell 20 at the inner facing surface of shift lever return spring 131 . Triple gear pulley 150 includes a generally cylindrical body 152 having a central through bore 153 through which cylindrical boss 58 extends. Cylindrical body 152 has a centrally located annular cable guiding groove 154 around the outer circumference thereof around which derailleur cable 57 extends. A pointed triangular nose 156 extends outwardly from the outer periphery of cylindrical body 152 and intersects with cable guiding groove 154 . Triangular nose 156 includes a cylindrical recess 158 at one side which extends partly therethrough, and an elongated slot 160 at the opposite side which extends into open communication with cylindrical recess 158 . Triangular nose 156 , as shown in FIG. 4 , is normally oriented in a lower position to the right side thereof. In this manner, cable 57 enters housing 16 and extends within cable guiding groove 154 from a position slightly to the left of triangular nose 156 , and through elongated slot 160 and cylindrical recess 158 . A cylindrical plug 162 ( FIG. 4 ) is fixed to the free end of cable 57 that extends through cylindrical recess 158 , and is fit within cylindrical recess 158 so as to secure the free end of cable 57 to triple gear pulley 150 at pointed triangular nose 156 . A small opening 157 is provided in the inner facing surface adjacent triangular nose 156 .
It will be appreciated that cable guiding groove 154 divides the outer circumference of triple gear pulley 150 into an inner circumferential section and an outer circumferential section. A first set of inner gear teeth 164 extend from the inner circumferential section and a second set of outer gear teeth 166 extend from the outer circumferential section, respectively, both starting from a position immediately above triangular nose 156 and extending upwardly and around triple gear pulley 150 to a position approximately diametrically opposite to triangular nose 156 . It will be appreciated that inner gear teeth 164 have a generally symmetrical trapezoidal appearance, while outer gear teeth 166 each have the same inclination in a direction toward triangular nose 156 and have a greater pitch than gear teeth 164 . As a result, and as will be appreciated from the discussion hereafter, gear teeth 166 are slightly offset from gear teeth 164 . A third set of outer gear teeth 168 extend around the outer circumferential section from a position slightly spaced from the end of the second set of outer gear teeth 166 to a position adjacent to the opposite side of triangular nose 156 . Gear teeth 168 have a generally symmetrical trapezoidal appearance.
As shown in FIGS. 5 and 29 , a coiled torsion gear return spring 165 is mounted between second half housing shell 20 and triple gear pulley 150 . The inner end of gear return spring 165 is bent to form a bent spring projection 167 that is fixed in offset opening 65 of second half housing shell 20 , while the outer end of gear return spring 165 is bent to form a bent spring projection 169 that is fixed in small opening 157 adjacent triangular nose 156 of triple gear pulley 150 . In this manner, gear return spring 165 functions to normally bias gear return spring 165 in the counterclockwise direction of FIG. 4 .
As shown best in FIGS. 3-5 , 30 and 31 , a pawl flange 170 is fixed to the outer facing surface of second half housing shell 20 . Pawl flange 170 includes a plate 171 having a main section 172 and a finger section 174 extending therefrom. Finger section 174 includes a through bore 176 through which a bolt 178 ( FIGS. 3 and 4 ) extends from the outer facing side thereof into threaded engagement with threaded opening 68 to fixedly secure pawl flange 170 to second half housing shell 20 . Pawl flange 170 further includes a short post 180 extending from the inner facing surface thereof at a left end position of main section 172 of plate 171 and a tall post 182 extending from the inner facing surface thereof at a lower position on main section 172 of plate 171 .
As shown in FIGS. 3-5 , 32 and 33 , a hold pawl 184 as part of an actuating arrangement is rotatably mounted on tall post 182 of pawl flange 170 . Hold pawl 184 includes a pawl lever 186 having a substantially central through bore 188 which is mounted on tall post 182 . A downwardly inclined pawl catch 190 is provided at one end of pawl lever 186 for engaging with gear teeth 166 of triple gear pulley 150 , to be described hereafter. Further, a post 192 extends from the outer facing surface of pawl lever 186 at the end thereof opposite pawl catch 190 for engagement with the upper arcuate surface of further slightly arcuate raised wall 108 .
As shown in FIGS. 3-5 and 34 , a main pawl 194 as part of an actuating arrangement is then rotatably mounted on long post 182 of pawl flange 170 on top of hold pawl 184 . Main pawl 194 includes a pawl lever 196 having an upper engagement surface 197 and a through bore 198 at one end by which main pawl 194 is mounted on tall post 182 . A downwardly inclined pawl catch 200 is provided at an opposite end of pawl lever 196 for engaging with gear teeth 164 of triple gear pulley 150 , to be described hereafter. Further, a post 202 extends from the outer facing surface of pawl lever 196 at the end thereof adjacent pawl catch 200 for engagement with the upper arcuate surface of slightly arcuate raised wall 106 .
A main pawl spring 204 normally biases pawl catch 200 into engagement with gear teeth 164 , as shown in FIGS. 3 and 4 . Specifically, main pawl spring 204 includes a cylindrical base 206 with a central through bore 208 through which tall post 182 extends. A first spring arm 210 extends from cylindrical base 206 at the inner facing end thereof and engages with the inner surface of annular inturned flange 42 . A second L-shaped spring arm 212 extends from cylindrical base 206 at the outer facing end thereof and engages with upper engagement surface 197 of pawl lever 196 . As a result, when an external force is applied to remove pawl catch 200 from gear teeth 164 , spring arms 210 and 212 are tensioned, so that when the external force is removed, spring arms 210 and 212 force main pawl 194 in the counterclockwise direction of FIG. 13 to force pawl catch 200 into engagement with gear teeth 164 .
As shown in FIGS. 3-5 , 36 and 37 , an advance pawl 214 as part of an actuating arrangement is rotatably mounted on post 140 of post sleeve 130 . Advance pawl 214 includes a pawl lever 216 having a lower engagement surface 217 and a through bore 218 at one end by which advance pawl 214 is mounted on post 140 of post sleeve 130 . An upwardly inclined pawl catch 220 is provided at an opposite end of pawl lever 216 for engaging with gear teeth 168 of triple gear pulley 150 , to be described hereafter.
An advance pawl spring 222 normally biases pawl catch 220 into engagement with gear teeth 168 , as shown in FIGS. 3 , 4 and 38 . Specifically, advance pawl spring 222 includes a cylindrical base 224 with a central through bore 226 mounted on boss 138 of post sleeve 130 below advance pawl 214 . A first L-shaped spring arm 228 extends from cylindrical base 224 at the outer facing end thereof and engages with the side edge of thin generally circular plate 132 of post sleeve 130 . A second L-shaped spring arm 230 extends from cylindrical base 224 at the inner facing end thereof and engages with lower engagement surface 217 of advance pawl 214 . As a result, when an external force is applied to remove pawl catch 220 from gear teeth 168 , spring arms 228 and 230 are tensioned, so that when the external force is removed, spring arms 228 and 230 force advance pawl 214 in the counterclockwise direction of FIG. 3 to force pawl catch 220 into engagement with gear teeth 168 .
As shown in FIGS. 3-5 and 39 , an advance pawl retaining ring 232 is snap fit onto post 140 of post sleeve 130 , and is held in annular groove 141 thereof, in order to retain advance pawl 214 and advance pawl spring 222 in position.
Further, as shown in FIGS. 5 and 40 , a return spring spacer 234 is mounted on substantially trapezoidal shaped upper end 60 of cylindrical boss 58 between post sleeve 130 and triple gear pulley 150 . Specifically, return spring spacer 234 includes a substantially circular plate 236 with a center substantially trapezoidal shaped through bore 238 of the same shape and dimensions as substantially trapezoidal shaped upper end 60 so as to fit therearound. As a result, return spring spacer 234 is not rotatable. An arcuate flange 240 extends in a coplanar manner from the edge of circular plate 236 for an angle of approximately 90 degrees, and has opposite inclined 242 and 244 .
In operation, in the neutral or rest position in which no gear change occurs, pawl catch 220 of advance pawl 214 sits on arcuate flange 240 of return spring spacer 234 and is thereby out of engagement with gear teeth 168 . At this time, also, pawl catch 200 of main pawl 194 is biased by main pawl spring 204 into engagement with gear teeth 164 so that the particular gear of the derailleur stays in position. Hold pawl 184 is not biased into engagement with gear teeth 166 , but may fall into one of these teeth by means of gravity.
For shifting in a direction to pull cable 57 in a first shifting direction denoted by arrow 101 , the person rotates shift lever 110 in a first pivoting direction of arrow 246 in FIG. 41 , that is, in the counterclockwise direction thereof. Because slide 80 is fixed to shift lever 110 , slide 80 also rotates in the same counterclockwise direction of FIG. 3 . In this position, compression spring 147 maintains the centered position of slide 80 . The amount of rotation of slide 80 is limited by advance roller 97 between stops 32 and 34 of first half housing shell 18 . In addition, advance of first roller 97 , during the initial rotation, is rotated to a position away from gap 35 , and in front of arcuate guide wall 36 , which prevents linear movement of shift lever 110 , that is, which only allows rotational movement thereof. Arcuate guide wall 36 and advance roller 97 form a limiting arrangement 99 for preventing the substantially linear sliding movement of slide 80 upon movement of the single lever 110 in the first pivoting direction, that is, these elements form arrangement 99 for limiting movement of the single lever only in a rotational direction. Further, because advance roller 148 abuts against guide wall 103 of slide 80 , post sleeve 130 also rotates in this counterclockwise direction. During this movement, advance pawl 214 rotates with post sleeve 130 and thereby moves past arcuate flange 240 of return spring spacer 234 . As a result, advance pawl 214 is no longer restrained by arcuate flange 240 and is biased by advance pawl spring 222 into engagement with gear teeth 168 . Continued rotation causes advance pawl 214 to thereby rotate triple gear pulley 150 in the counterclockwise direction of FIG. 3 in order to pull cable 57 . During this movement, main pawl 194 is caused to move out of a gear tooth 164 by the force of this rotation and against the force of main pawl spring 204 , and then be forced into engagement of the next gear tooth 164 by spring 204 . Since shift lever 110 can be rotated a distance to effect up to four gear shiftings in a single movement, main pawl 194 would repeat this operation, that is, be moved out of one gear tooth 164 and into the next gear tooth 164 , and so on, during this gear shifting operation. In like manner hold pawl 184 would perform a similar operation since it is not restrained at all.
When the rotational force on shift lever 110 is released, post sleeve 130 is biased in the clockwise direction by shift lever return spring 131 . Because advance roller 148 abuts against guide wall 103 of slide 80 , slide 80 and shift lever 110 also rotate in this clockwise direction. Because of the configuration of pawl catch 220 of advance pawl 214 , pawl catch 220 is caused to move in and out of gear teeth 168 during this return movement. In other words, advance pawl 214 is configured to move triple gear pulley 150 only in the counterclockwise direction. It is note that the tension on cable 57 would normally force triple gear pulley 150 back in the clockwise direction. However, to retain triple gear pulley 150 is this changed gear position, main pawl 194 engages gear teeth 164 and holds triple gear pulley 150 in position, because there is no rotational force of advance pawl 214 on triple gear pulley 150 . In this regard, cable 57 is pulled to effect a shifting operation in first direction denoted by arrow 101 .
For shifting in the opposite direction, the person linearly moves shift lever 110 in the direction of arrow 248 in FIG. 42 in a second substantially linear direction. Preferably, there is no rotational movement of shift lever 110 , that is, movement is purely linear. Since slide 80 is fixed to shift lever 110 , slide 80 also moves in this linear direction. As such, advance roller 97 on slide 80 moves through gap 35 on first half housing shell 18 .
Specifically, post sleeve or second roller 145 around the free end of center shaft 146 slidably moves within elongated recess 98 of slide 80 against the force of compression spring 147 . In addition, advance roller 148 rides along guide wall 103 of slide 80 . This arrangement of post sleeve roller 145 within elongated recess 98 of slide 80 and advance roller 148 riding along guide wall 103 of slide 80 together form an arrangement 199 for limiting movement of the single lever in a linear direction. It will be appreciated, however, that post sleeve 130 does not slide and is therefore stationary at this time. As a result, advance pawl 214 is restrained by arcuate flange 240 of return spring spacer 234 , and is thereby out engagement with gear teeth 168 during this entire shifting operation.
During this sliding movement, slightly arcuate raised wall 106 of slide 80 engages post 202 of main pawl 194 to move downwardly inclined pawl catch 200 out of engagement with gear teeth 164 of triple gear pulley 150 . At the same time, slightly arcuate raised wall 108 abuts post 192 of hold pawl 184 to move downwardly inclined pawl catch 190 into engagement with gear teeth 166 of triple gear pulley 150 . Therefore, at this time, triple gear pulley 150 is held in position only by hold pawl 184 . The spacing or pitch of gear teeth 166 is greater than the width of pawl catch 190 so that, during this initial engagement, triple gear pulley 150 is caused, by the pull force from cable 57 , to rotate slightly in the clockwise direction of FIG. 3 by a slight distance equal to the difference between the spacing or pitch of gear teeth 166 and the width of pawl catch 190 , until pawl catch 190 abuts against the edge of the respective gear tooth 166 to hold triple gear pulley 150 in position.
When the linear force applied to shift lever 110 is released, compression spring 147 forces slide 80 to move linearly to its original position. As a result, slightly arcuate raised wall 108 no longer abuts post 192 of hold pawl 184 , whereby downwardly inclined pawl catch 190 can be moved out of engagement with gear teeth 166 of triple gear pulley 150 . This occurs by reason of the tension on cable 57 moving triple gear pulley 150 in the clockwise direction of FIG. 3 , whereby hold pawl 184 is forced by this rotation out of engagement with gear teeth 166 . At the same time, slightly arcuate raised wall 106 of slide 80 no longer engages post 202 of main pawl 194 , whereby main pawl spring 204 forces main pawl 194 to move in the counterclockwise direction of FIG. 3 . However, triple gear pulley 150 already rotated slightly in the clockwise direction of FIG. 3 , as described above. As a result, there is no gear tooth 164 for main pawl 194 to engage. Therefore, triple gear pulley 150 starts to rotate in the clockwise direction of FIG. 3 by reason of the tension on cable 57 , until downwardly inclined pawl catch 200 of main pawl 194 engages the next tooth 166 and is forced into this next tooth 166 by main pawl spring 204 in order to hold triple gear pulley 150 in this position. As a result, cable 57 is released to effect a shifting operation in a second opposite direction denoted by arrow 103 in FIG. 42 .
It will be appreciated that various modifications can be made to the invention within the scope of the claims. For example, rather than shift lever 110 moving only in a linear direction during the reverse shifting operation, it can move in a slightly arcuate path in which it also rotates slightly while moving linearly. Further, it is possible to effect the linear movement of shift lever 110 after shift lever 110 is first rotated a small distance. In this regard, reference in the claims to substantially linear covers all of these arrangements.
Having described specific preferred embodiments of the invention with reference to the accompanying drawings, it will be appreciated that the present invention is not limited to those precise embodiments and that various changes and modifications can be effected therein by one of ordinary skill in the art without departing from the scope or spirit of the invention as defined by the appended claims. | 4y
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BACKGROUND
The invention lies in the field of the infusion pumps for dispensing fluid from syringes. I particular it relates to the control of the syringe holding and syringe plunger drive mechanisms of an infusion pump.
Infusion pumps are frequently employed in the medical field for administering medications of various types. Such pumps are often designed to accommodate a pre-filled syringe. The syringe is usually held in place by a clamping mechanism. The medication is expelled from the syringe by means of a motor driven pusher which pushes the plunger of the syringe.
In general an infusion pump for pumping fluid from a syringe therefore typically comprises the following elements: means to hold the syringe in place for pumping; pusher means for pushing the plunger of the syringe during pumping; and drive means such as a motor for driving the pusher means.
Typical syringe pumps of the prior art have separate controls for securing the syringe for pumping and for engaging the drive mechanism. Thus placing or removing the syringe and starting or stopping the infusion process required the use of both of the hands of the operator and made these operations somewhat cumbersome.
Placing the syringe and making the typical prior art pump ready for infusion also required at least the following operations: (1) opening the syringe holder; (2) placing the syringe; (3) positioning the pusher; (4) closing the syringe holder; (5) engaging the drive mechanism; and (6) turning on the drive mechanism. In the prior art, steps (1), (5), and (6) were all performed by separate mechanisms having separate controls often inconveniently spaced apart from each other at various positions on the syringe pump. The present invention enables steps (4), (5) and (6) to be performed by adjusting a single control or controls which are conveniently close to each other.
SUMMARY
The present syringe pump comprises a control system which permits several important operations to be performed single handed using a single control or controls conveniently located near each other on a control panel. The syringe pump has a lockable clamp for holding the syringe in place for pumping. It also has a pusher for pushing the plunger of the syringe to expel fluid from the syringe and a drive mechanism for driving the pusher. A single control knob engages and disengages the drive mechanism and locks and unlocks the syringe clamp.
The control may be in one of at least two positions. When the control is in a first position the syringe holder is unlocked and the pusher can move freely. Thus the drive mechanism is disengaged and the syringe can be placed in the pump and the pusher can be moved into position to abut the plunger. This allows the pusher to be correctly positioned relative to the syringe and the holder. When the control is moved into a second position, the syringe holder tightly closes on the syringe, holding it in place and the drive mechanism is engaged. The pusher cannot readily be moved independently of the drive mechanism and the pump is ready for use.
The control can then be moved into a third position in which the motor is activated and the pusher depresses the syringe plunger.
The control knob can be moved back to the first position for removal of the syringe, adjustment of the pusher or administration of a bolus dose. This can be done by means of a single control on the pump housing.
The invention will be further understood by reference to the following drawings and detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top perspective view of the preferred embodiment of an infusion pump according to the invention;
FIG. 2 is a top perspective view of the infusion pump as viewed from the right hand side of the pump of FIG. 1;
FIG. 3 is a top perspective view of the infusion pump viewed from the same point as in FIG. 2 but with the upper housing elements removed;
FIG. 4 is a top plan view of the infusion pump with the upper housing elements removed;
FIG. 5A is a close up perspective view of the syringe holder and drive assembly engagement mechanism in a disengaged state with part of the mechanism cut away for clarity;
FIG. 5B is a close up perspective view of the syringe holder and drive assembly engagement mechanism in an engaged state with part of the mechanism cut away for clarity;
FIG. 6 is a top perspective view of the syringe holder and drive assembly engagement mechanism with part of the mechanism cut away for clarity;
FIG. 7 is a top perspective view of the control knob shaft of the preferred embodiment;
FIG. 8 is a top perspective view of the disengage link of the preferred embodiment;
FIG. 9A is a perspective view of the cradle used in the drive assembly engagement mechanism of the preferred embodiment;
FIG. 9B is a top perspective view of the cradle taken from a different angle;
FIG. 10A is a top plan view of the syringe pusher;
FIG 10B is a top plan view of the syringe pusher showing the pusher swing arm in a different position from that shown in FIG. 10A;
FIG. 11 is a bottom perspective view the syringe pusher;
FIG. 12 is a top perspective view of the pole clamp assembly;
FIG. 13 is a rear perspective view of the clamp part of the pole clamp assembly;
FIG. 14A is a top plan view of the pole clamp assembly in the open position;
FIG. 14B is a top plan view of the pole clamp in the closed position;
FIG 15A is a bottom plan view of the eccentric of the pole clamp assembly; and
FIG. 15B is a bottom perspective view of the eccentric.
DETAILED DESCRIPTION
A preferred embodiment of the invention is shown in the drawings and will herein be described in detail. Referring to FIGS. 1 and 2, an infusion pump 10 is provided for causing fluid to be pumped from a syringe. A pump of this general type is disclosed in U.S. Pat. No. 4,838,857, which is incorporated by reference herein. Such pumps are frequently employed for administering drugs such as antibiotics over a time. They are preferably capable of accepting several sizes of syringes.
Pump 10 includes a housing 12 which is made from a durable, light weight material. Housing 12 comprises a base 12A, a mid housing 12B, a battery compartment cover 12C and a drive mechanism compartment cover 12D. An integral handle 14, which may also function as a battery compartment, is defined by one portion of the housing. A recess 16 is defined by handle 14, drive mechanism compartment 18, and a portion of base 12A. Recess 16 includes an elongate opening 20 which facilitates use of handle 14. A syringe pusher 22 is also positioned within recess 16. Syringe pusher 22 is adapted for engaging the flanged end of a syringe plunger and moving the plunger within the barrel of a syringe. The operation of the pusher is described in greater detail below. The recess has an elongated configuration of suitable length and width for accommodating a variety of syringe sizes.
A pair of control knobs is provided on the front face of the housing. A first knob 26 is used for controlling the pump driving mechanism and a syringe clamp to hold the syringe in place during pumping, both of which are discussed below. A second knob 28 is used to lock and unlock a pole clamp 30, as shown in FIG. 2. Pole clamp 30 is used for securing the pump to an I.V. pole or a rail (not shown).
Referring to FIGS. 3 and 4, a belt/pulley drive mechanism 23 is employed for driving syringe pusher 22. The drive mechanism 23 includes gear assembly 40 and a d.c. motor 34 including an integral reduction assembly. While a stepper motor could alternatively be employed, a d.c. motor is preferred as it requires less power and is controllable in a less expensive and complex manner than a stepper motor. Motor 34 is powered by an appropriate power source such as the four batteries 36 shown in FIGS. 3 and 4. The motor may have an integral reduction gear assembly which drives pinion 38. The output shaft of the motor includes pinion 38 which is engageable with a gear reduction assembly 40 which provides a substantial overall gear reduction. A reduction on the order of about 5,000:1 is provided by the combined operations of the integral reduction assembly of motor 34 and gear reduction assembly 40.
Gear 42 nearest to pinion 38 is mounted to a cradle 44, as shown in FIGS. 5A, 5B, 6, 9A and 9B. Cradle 44 is pivotably secured to a disengage link 46, which is shown in detail in FIG. 8. A peg 48 extending from cradle 44 is positioned within a slotted opening 50 within disengage link 46. A first set of opposing openings 52A, 52B within cradle 44 receives shaft 54 about which gear 42 rotates. A second set of openings 56A, 56B allows cradle 44 to be pivotably secured by pin 47 to a projection 58 extending from base 12A. Longitudinal movement of disengage link 46 accordingly causes cradle 44 to pivot about an axis extending through pin 47. Cradle 44 and disengage link 46 and their associated shafts, pins, springs and accessories are collectively referred to as "engagement means."
Disengage link 46 is positioned between projection 58 and a wall 60 which extends from base 12A. The end of disengage link 46 opposite from slotted opening 50 includes a laterally extending wall 62 having a rounded projection 64 extending from an edge portion thereof (See FIG. 6 which shows wall 60 and part of disengage link 46 cut away for clarity). Camming projection 64 is engageable with either of two notches formed in a wall 66 extending radially from shaft 68 of the control knob 26, depending upon the rotational position of control knob 26.
As shown in FIG. 4, disengage link 46 is urged in the direction of pinion 38 by a coil spring 70. When projection 64 is not positioned within one of the notches of wall 66, cradle 44 is in a generally upright position and gear 42 is disengaged from pinion 38. (See FIG. 5A which shows wall 60 removed and part of disengage link 46 cut away for clarity). Rotation of control knob 26 to a position where projection 64 moves into the notches of wall 66 causes the movement of disengage link 46 away from pinion 38. Cradle 44 accordingly rotates about pin 47, causing gear 42 to engage pinion 38. (See FIG. 5B which shows wall 60 removed and part of disengage link 46 cut away for clarity). A person of ordinary skill in the art will recognize that the means for engaging the motor and drive mechanism may be implemented in several equivalent ways, including by a clutch mechanism.
The drive mechanism for the pump includes an endless belt 72 which is supported by a drive pulley 74 and an idler pulley 76. Both pulleys are supported by the walls of base 12A. Drive pulley 74 is engaged with gear reduction assembly 40 and driven thereby. Syringe pusher 22 is secured to belt 72. As discussed above, first knob 26 controls the engagement and disengagement of pinion 38 and gear 42. When engaged, syringe pusher 22 can only be moved upon rotation of pinion 38. Neither syringe pusher 22 nor belt 72 can be moved manually at this time. When disengaged, syringe pusher 22 can be moved manually to a selected position as gear reduction assembly 40 provides little frictional resistance to rotation of belt 72. This allows pusher 22 to be moved within recess 20 with little resistance. A syringe can thus be easily positioned within recess 16 without obstruction.
Referring again to FIGS. 3 and 4, a clamp assembly 128 for clamping a syringe barrel is shown. In the prior art, such assemblies have generally included heavy springs to maintain a syringe in place. Because the user must open the clamp assembly to insert or remove a syringe, the force exerted by the spring must be limited to permit ease of use. Lower spring forces do not, however, provide effective holding capability. An alternative syringe clamp of the prior art includes a clamp operated by a screw. Such a device is cumbersome and it takes a long time to open and close such a clamp. Existing assemblies accordingly involve compromises due to these contradictory objectives.
The clamp assembly 128 in accordance with the invention provides both security and ease of use without compromising either feature. It includes a locking mechanism comprising a toothed member 130 which is pivotably secured to base 12A, a spring 132 for resiliently urging toothed member 130 about an axis of rotation, a clamping slide 134 for engaging a syringe barrel, and a spring 136 for resiliently urging the slide in a selected direction.
Toothed member 130 preferably includes a toothed surface 138, as best shown in FIG. 4. This surface is located in opposing relation to a toothed surface 140 of clamping slide 134. Toothed member 130 is pivotable about a pin 142 such that the toothed surface of toothed member 130 is movable into and out of engagement with the toothed surface of the slide. Spring 132 urges the toothed member out of engagement with clamping slide 134.
Referring to FIG. 7, shaft 68 of control knob 26 includes a flat longitudinal surface 144 at the bottom thereof, the remainder of shaft 68 being a substantially cylindrical camming surface 145. Toothed member 13 0 includes an arm 146 which adjoins the bottom portion of shaft 68. The rotational position of flat surface 144 determines whether arm 146 engages the flat or cylindrical surface of shaft 68. If flat surface 144 is moved into opposing relation with arm 146, spring 132 causes toothed member 130 to move out of engagement with slide 134. Rotation of shaft 68 causes the cylindrical surface to engage arm 146, thereby rotating toothed member 130 about pin 142 and into engagement with slide 134.
Slide 134 houses spring 136 which causes it to move into engagement with a syringe barrel. Spring 136 extends between a projection 148 extending from base 12A and an inner wall of slide 134. Slide 134 includes a face portion 150 having an arcuate surface for accommodating a syringe barrel. Face portion 150 extends vertically with respect to base 12A and is positioned within recess 16.
While a linear slide 134 is disclosed, a person of ordinary skill in the art would be able to implement this aspect of the invention in several equivalent ways, for example by substituting a rotatable clamping member for slide 134.
The orientation of wall 66, flat portion 144 and camming surface 145 of shaft 68 determine the order of the engagement of gear 42 with pinion 38 and toothed member 130 with toothed surface 140. Wall 66, flat portion 144 and camming surface 145 can be oriented such that (1) gear 42 and pinion 38 mesh simultaneously with each other when flat portion 144 causes toothed member 130 to engage with toothed surface 140; (2) gear 42 and pinion 38 mesh only once toothed member 130 and toothed surface 140 engage or (3) gear 42 and pinion 38 mesh before toothed member 130 and toothed surface 140 engage. Wall 66, flat portion 144 and camming surface 145 can also be oriented so that gear 42 and pinion 38 can be engaged and disengaged while toothed member 130 and toothed surface 140 remain engaged. The preferred embodiment option (1) is described herein with the understanding that a person of ordinary skill in the art would easily be able to modify the device to accomplish options (2) and (3).
The same result could also be achieved by a person or ordinary skill in the art by substituting an equivalent electrical or electromagnetic system for the mechanical system disclosed herein to engage and disengage the drive mechanism and to lock and unlock slide 134.
Before or after securing the pump 10 to the pole, control knob 26 is turned to a "release" position if not already in such a position. A filled syringe is positioned in recess 16 of the pump housing such that the flange of the syringe barrel extends within slot 152. Syringe pusher 22 is then manually engaged and moved into position against the flanged end of the syringe plunger. The flange of the syringe plunger is clamped between lip 82 of the swing arm 80 and one of the projections 94, 96 extending from bottom wall 98 of the pusher housing.
When in the "release" position, notched wall 66 extending from shaft 68 of control knob 26 exerts no pressure upon the disengage link 46. Coil spring 70 accordingly positions disengage link 46 such that cradle 44 is substantially upright and gear 42 of gear reduction assembly 40 is disengaged from pinion 38 extending from d.c. motor 34. In addition, toothed member 130 rides upon flat surface 144 of the shaft of control knob 26, allowing spring 132 to maintain toothed member 130 out of engagement with slide 134 of syringe clamp assembly 128. The on-off switch for the motor is, of course, in the "off" mode at this time due to the position of motor on/or switch 214 with respect to a switch actuating peg 216 which extends radially from the shaft of control knob 26. On-off switch 214 is shown as actuated by control knob 26, but can of course be actuated by a separate control.
Two additional settings are provided in accordance with the preferred embodiment of the invention, "motor off" and "motor run". When control knob 26 is turned from "release" to "motor off", the curved portion of the bottom of shaft 68 engages toothed member 130, thereby urging it into engagement with slide 134 of syringe clamp assembly 128. Radially extending wall 66 of shaft 68 simultaneously engages laterally extending wall 62 of disengage link 46, urging disengage link 46 away from gear assembly 40. These two actions cause syringe clamp assembly 128 to be locked in position and gear reduction assembly 40 to engage pinion 38 via gear 42 mounted to the cradle 44. Control knob 26 is maintained in the "motor off" position as one of the two notches within wall 66 receives rounded projection 64 of disengage link 46.
Control knob 26 may be turned to a second detent (run) position wherein rounded projection 64 moves within the second notch of wall 66 extending radially from control knob shaft 68. The positions of disengage link 46 and toothed member 130 are the same whether control knob 6 is in the "motor off" or "motor run" position. When moved to the "run" position, however, peg 216 extending from the shaft 68 of control knob 26 engages motor on/off switch 214, thereby causing motor 34 to operate.
It is important to insure that a syringe is properly positioned prior to operating the pump. Both the plunger flange and the syringe barrel flange must be properly engaged to insure proper positioning. The system for detecting whether the plunger flange is properly engaged is described below with respect to syringe pusher 22. Means are also provided for insuring that the syringe barrel flange is properly positioned before the motor 34 is allowed to operate.
Syringe pusher 22 is shown in greatest detail in FIGS. 10A, 10B and 11. FIG. 10B shows pusher 22 as positioned when engaging the flanged end of a syringe plunger while FIG. 10A shows it in the fully closed position where no plunger would be engaged.
Syringe pusher 22 includes a housing 78 to which a swing arm 80 is pivotably mounted. Swing arm 80 includes a lip 82 suitable for engaging the flange of a syringe plunger. A spring 84 is secured to a peg 86 extending from the opposite end of swing arm 80, and urges it towards the position shown in FIG. 10A. A first switch 88 is mounted to housing 78 for detecting the position of swing arm 80. Different signals are accordingly provided depending upon whether arm 80 is in the position shown in FIG. 10A or FIG. 10B. The presence or absence of a syringe may accordingly be detected. In addition, the user will be alerted as to whether the syringe plunger flange is properly engaged. The latter feature is important in that swing arm 80 provides anti siphon protection. In other words, the syringe plunger cannot be moved on its own while clamped to syringe pusher 22 and while motor pinion 38 is engaged as described above.
A lever 90 is also pivotably mounted to syringe pusher housing 78. Lever 90 is positioned adjacent to a second switch 92 which provides a signal when an occlusion is detected or when the syringe plunger has reached the end of the bottom of the syringe barrel. A cover 93 is secured to housing 78 for protecting lever 90 and switches 88, 92.
A pair of projections 94, 96 is secured to lever 90 and extends through a pair of openings in bottom wall 98 of housing 78. First projection 94 is longer than second projection 96 and is positioned closer to pivot 100 about which lever 90 rotates. A spring 102 resiliently urges lever 90 towards bottom wall 98 of housing 78. It will be appreciated that a greater force is required to move lever 90 when first projection 94 is used to apply a force to it than when the second projection 96 is so employed. The projections are accordingly positioned such that the flanged end of a relatively large syringe mounted to the pump will engage first projection 94 while the flanged end of a relatively small syringe will engage second projection 96. A greater force is accordingly required to actuate switch 92 when a large syringe is in place than when a small syringe is employed. This is desirable as a greater force is required to drive the plunger of a large syringe than a small syringe under normal operating conditions. A correspondingly larger force should be necessary to generate an occlusion signal when a large syringe is being emptied than when a small syringe is emptied.
As discussed above, syringe pusher 22 is secured to belt 72. A connecting member 104, as best shown in FIG. 9, extends from housing 78. Connecting member 104 includes three projections 106, 108, 110. Belt 72 is positioned between projections 106, 108, 110 such that the toothed surface thereof engages a toothed surface 112 of lower projection 110. Connecting member 104 extends through an elongate slot 112 (FIG. 1) in housing 12 which adjoins recess 16 in which a syringe may be positioned. A channel 114 is defined by the connecting member. The channel receives the upper edge of a wall of the mid housing 12B. The opposite end of the syringe pusher 22 includes a projection 116 which rides upon another upper edge of the mid housing 12B. A relatively narrow, elongate slot 118 is defined within handle 14 for receiving projection 116. Syringe pusher 22 is accordingly supported at both ends by mid-housing 12B.
A resilient, semi rigid, elongate band 120, as best shown in FIG. 3, is provided for covering slot 112. Band 120 is preferably opaque, and includes a plurality of openings 122 extending through at least a portion thereof. Band 120 is sufficient in length and width to cover the entire slot regardless of the position of syringe pusher 22. A rectangular notch 124 is provided within the band for receiving connecting member 104 of syringe pusher 22. Band 120 is accordingly movable with the syringe pusher about a generally oval path. Mid-housing 12B may include a slotted wall (not shown) for guiding band 120 about the path shown in FIGS. 3 and 4.
Band 120 is preferably employed for several purposes in addition to serving as a liquid barrier. It accordingly includes openings 122 which are equidistantly spaced. Lines may be printed upon band 120 in lieu of the openings. A detector 126 as shown in FIGS. 3 and 4 is positioned adjacent to band 120 and detects each opening as the band moves with the syringe pusher. Detector 126 and band openings 122 function in combination to insure that the syringe pusher has not become detached from the belt and that the syringe pusher is, in fact, moving as motor 34 is operating. They also allow the injection rate to be determined as the rate at which the openings 122 pass by detector 126 is detected. Portions of band 120 which do not pass by detector 126 need not be provided with openings.
Referring to FIG. 1, a slot 152 is formed within the drive mechanism compartment cover 12D and the mid housing 12B. A generally curved wall 157 is provided in mid-housing 12B such that a syringe barrel may be placed and clamped against curved wall 157. First and second walls 154, 156 bound slot 152. First wall 154 extends away from the plane of curved wall 157 approximately equal to the thickness of the barrel wall of a syringe. Referring now to FIGS. 3 and 4, a pivotably mounted sensor link 158 is positioned in curved wall 157 just below second wall 156 in opposing relation to the face portion 150 of the slide. Sensor link 158 extends through a slot 159 adjoining the second wall 156, and is engageable by a syringe only if the flange thereof is positioned within slot 152 between walls 154, 156. First wall 154 thus prevents sensor link 158 from being engaged by the barrel of a syringe unless the flange thereof is within slot 152 and the syringe barrel lies flush against curved wall 157. If not so positioned, wall 154 engages the syringe barrel so that it is spaced from the sensor link 158. A detector 160 is positioned adjacent to the sensor link. Detector 160 is closed when the flange of a syringe barrel is properly positioned with slot 152 and barrel wall engages sensor link 158.
Lever 90 and associated switch 92 of the syringe pusher function in conjunction with a second switch 162. This switch 162 is positioned at or slightly above a point corresponding to the position of the plunger of the largest size syringe to be employed within the pump when it reaches the end of the syringe barrel. Switch 162 is closed by connecting member 104 of the syringe pusher 22 as it nears the end of its travel within the recess 16.
The signal provided by switch 162 does not, by itself, cause the pump to stop operating or cause any alarms to be sounded. This is because the signal is generally provided while there is still fluid within the syringe barrel. It is only when switch 92 within the syringe pusher also provides a signal that the motor 34 is shut off and an end of infusion alarm is generated.
Unlike an occlusion, which requires prompt attention, the end of infusion does not ordinarily require immediate action on the part of a medical staff. It is accordingly desirable to distinguish between the alarms to be provided for these respective conditions. Pump 10 accordingly includes the necessary hardware for allowing a more urgent alarm to be generated in the event of occlusions than is generated at the end of infusion. If signals are generated by both switches 92, 162, a non-urgent alarm can be provided. If a signal is received only from the switch 92 within the syringe pusher, a different and more urgent alarm can be generated.
As discussed above, a syringe is positioned within recess 16 such that the flange of the syringe plunger is engaged by lip 82 of swing arm 80 of syringe pusher 22 and the flange of the syringe barrel is positioned within notch 152. Actuation of motor 34 causes rotation of pinion 38, the gears comprising gear reduction assembly 40, and, in turn, drive pulley 74 to which drive belt 72 is mounted. Movement of drive belt 72 causes syringe pusher 22 to move the syringe plunger into the syringe barrel, thereby causing fluid to be displaced outwardly from the barrel. The syringe pusher moves at a steady speed until the syringe barrel has been emptied completely, unless an occlusion occurs beforehand. As it moves, band 120 moves with it, thereby preventing contaminants from entering the pump housing through slot 112. Openings 122 of band 120 are detected by detector 126 in order to insure that syringe pusher 22 is, in fact, moving with belt 72. A typical syringe pusher speed may be about five to six inches per hour, though the pump may be designed to operate at different or variable speeds chosen by the operator, depending upon its intended use.
Assuming normal operation, syringe pusher 22 moves downwardly through recess 16 and closes end of infusion switch 162 when it approaches the end of its travel. Switch 162 is maintained in the closed position while the syringe pusher 22 urges the syringe plunger into engagement with the end of the syringe barrel. Further movement of syringe pusher 22 from this point causes lever 90 to be displaced until it closes "occlusion" switch 92. The closure of "occlusion" switch 92 causes motor 34 to be disconnected from the power supply. Such disconnection may be effected through the use of a microprocessor or mechanical means, the former being preferred.
The use of microprocessors, alarms and displays in connection with medical infusion devices is well known to the art, and need not be discussed in detail with respect to the present invention. U.S. Pat. No. 4,838,857, for example, discloses one such microprocessor-controlled pump having alarms for indicating problems, such as occlusions, and displays for alerting the operator to various pump conditions.
If lever 90 is caused to close "occlusion" switch 92 before end of infusion switch 162 is closed, a signal is generated indicating the occurrence of an occlusion. Such a signal causes a different alarm and/or display to be generated than when "occlusion" switch 92 is closed after the end of infusion switch.
The syringe may be removed once emptied by turning control knob 26 to the "release" position. This action releases both toothed member 130 from slide 134 of the syringe clamp assembly 128 and reduction gear assembly 40 from pinion 38 extending from motor 34. Pusher 22 and swing arm 80 thereof may then be displaced with respect to the syringe plunger, and slide 134 displaced with respect to the pump housing. The syringe is easily removed once these retaining elements have been moved.
FIGS. 12-15B show the pole clamp 30 and the mechanism for moving the pole clamp between a storage position where it is substantially flush with pump housing 12, as shown in FIG. 14B, and a deployed position as shown in FIG. 14A. As discussed above, the pole clamp is operated by turning knob 28 shown in FIGS. 1 and 2.
The pole clamp 30 has a generally L-shaped construction, the longer section thereof being slidably mounted within a recess 164 within base 12A. A generally rectangular opening 166 extends through the longer section of pole clamp 30. A rectangular protrusion 168 extends within opening 166 at a corner thereof.
A wall 170 having a surface 172 including ratchet teeth extends from a surface of pole clamp 30 towards the drive mechanism compartment cover 12D. Wall 170 adjoins the lower edge of the pole clamp 30 and extends below a recessed area 174 therein.
The clamping surface 32 of pole clamp 30 facing the drive mechanism compartment cover 12D includes centrally located recessed area 174 which is bounded by a peripheral wall 176. Opening 166 extends through recessed area 174 while toothed wall 170 extends from peripheral wall 176. A carriage 178 is slidably positioned within recessed area 174. Carriage 178 includes an oval opening 180 which is aligned with a portion of opening 166 extending through pole clamp 30. An arcuate recess 182 is formed within carriage 178 near the inner end thereof. An integral peg 184 extends from carriage, and is located adjacent to the arcuate recess.
A pawl 186 is pivotably mounted to peg 184. Pawl 186 includes a set of ratchet teeth 188 which are engageable with toothed surface 172 of wall 170 extending from pole clamp 30. A peg 190 extends from pawl 186 and into arcuate recess 182. A spring 192 positioned within arcuate recess 182 engages peg 190, thereby urging pawl 186 towards engagement with toothed surface 172 of wall 170. Clamp 30 is thereby releasably locked to carriage 178.
Referring to FIG. 13, the side of pole clamp 30 opposite to wall 170 includes an elongate slot 194 extending along an edge thereof. A peg 196 extends from the inner end of slot 194. As shown in FIGS. 10, 12A and 12B, a slot 198 is provided within base 12A which at least partially overlaps slot 194 in pole clamp 30. A peg 200 extends from one end of slot 198. An extension spring 202 is secured to pegs 196, 200 and resiliently urges pole clamp 30 towards the open position shown in FIG. 14A.
Referring to FIGS. 15A and 15B, knob 28 for controlling the pole clamp 30 is shown without the cap portion thereof. Knob 28 includes a cylindrical shaft 204 having a notch 206 defined in the lower end thereof. The shaft is secured to an eccentric cam 208. The axis of eccentric cam 208 is offset from that of shaft 204 by about an eighth of an inch. Shaft 204 is rotatably fixed to housing 12. Eccentric cam 208 is positioned within oval opening 180 of carriage 178 while the notched end portion extends within elongate opening 166 within pole clamp 30. The purpose of oval open 180 is simply to provide clearance for eccentric cam 208. Lateral movement of carriage 178 is restricted by the degree to which eccentric is offset from the axis of shaft 204. A peg 209 extends radially from eccentric cam 208.
In operation, pump 10 is placed in adjoining relation to an I.V. pole 210 (shown cut in two for clarity) or the like in the manner shown in FIG. 14A. Pole clamp 30 is manually pushed inwardly until the I.V. pole abuts against both the shorter section of pole clamp 30 and recessed side 212 of the pump. The teeth on upper surface 172 of wall 170 are oriented such that they slide along pawl 186 as pole clamp 30 is moved with respect to carriage 178. The engagement of pawl 186 and surface 172 prevents pole clamp 30 from moving open again under the force of spring 202. Knob 28 is then turned about ninety degrees, causing eccentric cam 208 to move carriage 178 and pole clamp 30 by an additional fraction of an inch (i.e. The offset of the axis of eccentric cam 208 from that of shaft 204) towards pole 210 Clamp 30 is thus tightened against pole 210 which tightly clamped between clamping surface 32 of pole clamp 30 and recessed side 212 of the pump. When knob 28 is rotated by 90° the axes of eccentric cam 208 and shaft 204 are horizontally in line with each other. Since pawl 184 is pivoted at peg 184, at a point above upper surface 172 of wall 172, teeth 188 of pawl 186 will tend to prevent disengagement of pawl 186 from the teeth of upper surface 172.
Pole clamp 30 is constructed such that knob 28 cannot be turned until pole clamp 30 is pushed in towards the I.V. pole from its fully extended position. As shown in FIG. 12A, the protrusion 168 is positioned within notch 206 when pole clamp 30 is fully extended. Knob 28 can only be turned when protrusion 168 is moved out of the notch.
The pump may be removed from the I.V. pole by turning knob 28 in the opposite direction from that used to tighten the clamp. The initial rotation of knob 28 causes pole clamp 30 to move outwardly a fraction of an inch due to the movement of eccentric cam 208. Further rotation causes peg 209 extending from eccentric 208 to engage pawl 186 and rotate it about peg 184 extending from carriage 178. The teeth of pawl 186 are thereby disengaged from those of upper surface 172. Upon such disengagement, spring 202 causes pole clamp 30 to move to the fully extended position where the pump can easily be removed from the pole.
Although illustrative embodiments of the present invention have been described herein with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various other changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention. | 4y
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FIELD OF THE INVENTION
Computer carrying cases, more particularly a computer carrying case with a fold down shelf that provides support for the computer carrying case when open and standing on a flat surface.
BACKGROUND
The revolution in computers has resulted in the miniaturization of components. Now, computers such as notebook-sized computers with fold-out monitors are able to be carried in a small briefcase. This reduction in size has opened up a new market. For example, salesmen can now go into the field with a huge inventory of samples and order forms capable of being called up from the memory of a notebook-sized computer or auxiliary storage device like CD ROM and displayed on the monitor. For a second example, carpet or tile salesmen may go to a job and be able to calculate square footage, and prices for a number of different items, right in the consumer's work place or home with the use of the appropriate program and storage data. Insurance adjusters may now take computers out to the scene of the property or automobile damage, call up the appropriate electronic forms, and input data directly into stored form, without creating a hard copy. In addition, much programmed information can be provided in the form of additional related documents that heretofore would fill a large filing cabinet.
Notwithstanding the sometimes remarkable evolution of the electronic components towards miniaturization, there has been a singular lack of related development in the field of carrying containers for the small, often delicate, electronic units and related peripherals such as CD ROMS, printers, modems and the like. This is especially true in the view of the new and vast market created by such miniaturization. For example, the typical carrying case for the notebook computers and related peripherals is a soft-sided (often leather) container. While one can appreciate the aesthetic qualities of such cases, the environment in which they are carried or transported, often by salesmen or insurance adjusters,--the equipment bouncing around the back seat or the trunk of a car or out on a field site,--leaves much to be desired in protection of the delicate electrical components. Further, the components are not interconnected.
Even such hard cases that are presently available are no more than glorified camera cases. They will typically have blocks of foam inside a hard shell. The foam may be cut out to fit a computer and its peripheral components. While such hard-sided cases afford protection not available with the soft-sided cases, they still leave much to be desired. Specifically, such cases fall short in that they do not allow the user the capability of organizing and interconnecting the various computer components such as the computer notebook and a printer. That is, the presently available hard cases typically require the user to connect up the various computer components after opening up the case, removal and before use.
A need presently exists for a hard case for carrying computer related components which also allows some organization of the components. Essentially, a need exists for what amounts to a "portable desk" within a hard-sided carrying case. Typically a worker sitting at his desk would have his computer hooked up to peripherals such as printers, modems, CD ROMS and the like. What is needed is a hard-sided carrying case that will provide compartments and shelves onto which the components could be placed such that upon opening the case, a very minimum amount of work is required before the user can begin operating his work station. Quite simply, a portable desk.
Thus, it is the object of the present invention to provide for a hard-sided computer carrying case which provides support for and storage compartments for a small computer, such as notebook-size computer and related, interconnected peripherals.
It is an additional object of the present invention to provide for a hard-sided computer carrying case which has options allowing the case to be either carried or rolled along.
It is an additional object of the present invention to provide for a hard-sided computer carrying case for carrying computers and related components which will provide support surfaces for the computer and related components which are retractable or foldable within the case, while additionally providing support surfaces, allowing the user to operate a computer keyboard while it is attached to the case.
It is an additional object of the present invention to provide for a carrying case for a computer and related components that can be used on a desk or at a table as a work station, may be stood up vertically to be used by persons sitting as a desk, or can be used by a person standing, wherein all three positions provide convenient access to the computer keyboard and interconnect with related peripherals.
This and other of objects are provided for in a carrying case for electronic components such as lap top computer, printer, CD ROM and the like, the case having a first shell half and a second shell half connected along hinged edges. One shell half has contained within it one or more shelves foldable from a stored position laying parallel to the plane of the shells to a use position perpendicular thereto, the shelf lockable in the use position and assisting in maintaining the balance of the carrying case when the two shell halves are open with respect one to the other.
The carrying case may also have wheels and an extendable handle for pulling the closed case along the floor. Further, the carrying case extendable handle is provided with a removable support shelf on which to place a keyboard or pen pad for pen based computing applications, allowing the user to sit or stand at the support shelf while computing.
SUMMARY OF THE INVENTION
The invention provides a carrying case having a first shell, being generally rectangular and having a bottom surface, and a second shell, similarly shaped. The shells are pivotally connected one to the other, and either one of the two shells has attached a first shelf which is foldable between a closed position, the closed position in which the first shelf is generally parallel to the bottom wall, and an open position in which the first shelf is generally perpendicular to the open wall and lays in such a position as to provide support for the carrying case when the shelves are open and the shelf is folded down.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of the exterior of applicant's carrying case.
FIG. 2 is an isometric view of applicant's carrying case in an open position with the handle extended therefrom and the shelves in a folded-up position, and with the divider door open.
FIG. 3 is an isometric view of the carrying case of applicant's invention, in an open position, with the shelves folded down and the handle extended and supporting a removable member thereon.
FIG. 4A is a cross-sectional view in elevation of details of the first shelf and the locking bar as they engage near edge 34a of the first shelf.
FIG. 4B is a cut-away view in side elevation showing details of the manner in which removable member 82 engages the handle.
FIG. 4C is a cut-away view in perspective of details of the second shelf as it engages the first shell.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Applicant's case (10) is comprised of container (12) having a first shell (14) and a second shell (16), both shells being generally rectangular. FIG. 1 illustrates first shell (14) and second shell (16) attached by hinge means (18) along adjacent sides thereof. The interior of case (10) is comprised of a first shelf (20) and a second shelf (22) rotatably attached to the interior of first shell (14) such that shelves (20) and (22) can rotate between a closed position with the shelves lying substantially in the plane of the bottom surface of first shell (14) to an open position substantially perpendicular thereto (see FIG. 3). On the interior of second shell (16) is rotatably attached a divider door (24) providing access to a compartment for locating computer accessory items. First shelf (20) and second shelf (22) provide support for a notebook computer with its built-in monitor and an accessory device such as a printer, fax machine, modem or the like, when case (10) is in an open position and shelves (20) and (22) are folded down. Components are releasably attached to shelves (20) and (22) such that the shelves may be rotated to their closed positions without having the components fall off.
Turning now in more detail and with reference to FIGS. 1, 2 and 3, shells (14) and (16), are generally rectangular with a bottom surface (26a) of first shell (14) and (26b) of second shell (16) opposite the shell opening. Perpendicular to bottom surfaces (26a) and (26b) are near side walls (28a) and (28b), far side walls (30a) and (30b), top end walls (32a) and (32b), bottom end walls (34a) and (34b). Thus, the bottom surface with its perpendicular walls forms a typical shell such as is found in many suitcases.
Shells (14) and (16) are typically made of hard plastic or aluminum or other sturdy, durable and shock resistant material. The walls of shells (14) and (16) terminate at a perimeter defined by near edge (36a) and (36b) (see FIG. 1), far edge (38a) and (38b), top edge (40a) and (40b) and bottom edge (42a) and (42b).
It is seen then, how shells (14) and (16) are attached by hinge means (18) along edges (38a) and (38b). Latch means (44) on first shell (14) is designed to engage a typical hook located on edge (36b) of second shell (16) in a manner well known in the art. It is also noted that stationery-handles (48) such as those found along edge (40a) and edge (36a) of first shell (14) provide the user a means of carrying case (10) from one of two positions. In addition, case (10) may be rolled along on wheels (49) (see FIG. 1) by extending extensible handle (50) and grasping grip portion (51) thereof.
Turning now to an examination of the interior of container (12) and with reference to FIGS. 2 and 3, it is noted that container (12) may be opened or closed in typical suitcase fashion by pivoting shells (14) and (16) along hinge means (18). It is further seen that first shelf (20) may be positionally engaged from an open to a closed position by use of a locking bar (52) slidably mounted along the outer surface of shelf (20) in guide means (53). First shelf (20) articulates from a closed or folded position in which it lies substantially in the plane of bottom surface (26a) to an open or use position which is perpendicular to the closed position, by pivoting along hinge (54). The open position provides the worker with a handy support member on upper surface of shelf (20) on which to place a computer or the like. Further, first shelf (20) acts as "third leg" to support the open case when first shelf (20) is locked in the down or use position and case (10) is placed vertically as illustrated in FIG. 3. It is seen that locking bar (52) movable along guide means (53) is slidable through support bar (56) at a notch (57) (see also FIG. 4C). This allows support bar (56) to maintain first shelf (20) in a closed position. User may slide locking bar (52) out of notch (57) which holds locking bar (52) in a disengaged or up position (see FIG. 2), and rotate first shelf (20) to a down or use position along hinge (54). Referring now to FIGS. 2, 3, 4A and 4C, it is seen that hinge (54) is integral with base bar (59) and has a slot (61) therethrough (see FIG. 4A). Slot (61) is centrally located and aligned with locking bar (52) such that the removed end of locking bar (52) may slide through base bar (59) at slot (61). When removed end of locking bar (52) is urged through slot (61), it engages a wedge (63). Locking bar (52) is typically made of metal which has some resiliency and when locking bar (52) rides up on wedge (63), its surface is pressed tightly against the surface of base bar (59). The action of urging locking bar (52) through slot (61) and against wedge (63) then serves to maintain first shelf (20) in its open or use position perpendicular to bottom surface (26a). Another way of viewing it is that the action of locking bar (52) against wedge (63) maintains first shelf (20) in a position parallel to and extending from bottom end wall (34a).
Additional details, appreciated from FIGS. 1 through 4C, are feet (58), of which there are typically two, located at the removed corners of the underside of rectangular first shelf (20). Tabular shaped base bar (59) is provided vertically adjacent to bottom end wall (34a) near bottom edge (42a) thereof. Pivotally attached to the removed edge of base bar (59) is supporting hinge (54) which allows for shelf (20) to pivot freely between the folded or closed position and the open or use position.
Second shelf (22) pivots along a hinge (62), hinge (62) being mounted to support bar (56). Slidable latch (60) is provided along the top surface of second shelf (22) to maintain the second shelf in a closed position.
Turning now to the details of second shell (16), it is seen that second shell (16) is dimensioned generally rectangular and similar to that of first shell (14). It is noted that both first shell (14) and second shell (16) are provided with foam (66) for lining the interior thereof to protect the sometimes delicate, electronic and computer related components which are designed to be carried in case (10) (FIGS. 2 and 3 show the foam removed except for the upper compartment of shell (14) in FIG. 3, for the purposes of illustrating details which may otherwise be covered by foam (66)). Divider door (24) is provided with a closure means such as a hook and pile strap system (69) illustrated in FIGS. 2 and 3.
Other useful items provided with case (10) include: Power cords, connector cables (68) and junction boxes (70). The latter may sometimes provide electronic communication between devices within container (12) and those outside of the container. Hold down straps (74) are also provided within the auxiliary component compartment defined by divider door (24) of second shell (16).
Note also in FIG. Z how second shell (16) has molded therein extensible handle compartment (78) for housing retractable, extensible handle (50). Extensible handle (50), when in the removed position as indicated in FIG. 3, can be seen to be have extensible handle grip (51) at the removed end thereof, the grip capable of providing support to removable member (82). In this fashion, removable member (82) may be stored within the auxiliary compartment and removed for engagement with extensible handle (50) in a manner illustrated in FIGS. 3 and 4B. This will provide a suitable base for a worker in the field to place a computer for use while seated or standing, the computer hooked up by connector cable (68) through junction box (70) to components within container (12). FIG. 1 illustrates a junction box (70) which is capable of connecting electrical components by a power cord connected through the walls of case (10).
FIG. 4B illustrates how removable member (82) having lips (82a) and (82b) engage handle (50) and grip (51) to allow member (82) to stay suspended from handle (50).
The use of the portable carrying case described herein allows computers and accessories (printer, CD ROM, fax machine, etc.) to be assembled and "ready to go." Moreover, using the two-wheeled version with the extendable handles increases the carrying load capability, thereby allowing more components such as digitizing camera, laser quality printer, cellular phone, paper, manuals, tools and the like to be carried. The storage compartment of the carrying case may be used to house AC/DC convertors, machine cord, AC power cord, tools and some accessories.
Typically, though not necessarily, the lower hinged shelf is designed to carry the computer or other components. Also, the computer shelf acts as a "third leg" to help stabilize the open carrying case as it rests in a vertical position on a flat surface. The upper hinged shelf is typically used for accessories such as a printer, fax machine, cellular phone, CD ROM or other device. The frame is constructed of cold rolled steel. The components attach to the shelves with releasable hook and loop fasteners. Convoluted foam backing protects the fragile electronic components. An optional paper storage compartment may be mounted on the divider door. Both, the hinged computer compartment and the hinged accessory compartments dimensions are approximately 91/2"×111/2"×21/2". This will allow most notebook class computers to fit in it. In addition, the hinged accessory compartment dimensions are suitable for most cut sheet printers, CD ROMs, cellular phones, fax machines, scanners, etc.
Thus, applicant provides unique, free-standing computer and accessory portable desk for use on a flat surface while sitting at a chair or standing up. Used as a portable desk, the unique carrying case of applicant's present invention provides a work place for use in warehouses, machine shops or the like with an optional handle mount for holding test equipment or computers. For example, the present system is particularly adaptable for use with pen-based computer operations, like taking inventory, etc.
Terms such as "left", "right", "Up", "down", "bottom", "top", "front", "back", "in", "out" and the like are applicable to the embodiment shown and described in conjunction with the drawings. These terms are merely for the purposes of description and do not necessarily apply to the position or manner in which the invention may be constructed or used.
Although the invention has been described with reference to a specific embodiment, this description is not meant to be construed in a limiting sense. On the contrary, various modifications of the disclosed embodiments will become apparent to those skilled in the art upon reference to the description of the invention. It is therefore contemplated that the appended claims will cover such modifications, alternatives, and equivalents that fall within the true spirit and scope of the invention. | 4y
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention is related to methods for increasing the productivity of aquatic farms and more particularly to a method for improving the health of a population of crustaceans by dosing a carotenoid concentrate obtained from a natural source, to the feed of a population of crustaceans, that results in a noticeable weight increase, as well as in an increase of the survival rate.
[0003] 2. Description of the Related Art
[0004] Carotenoids are widely distributed in nature. Total annual production in nature is estimated at over 100 million tons. This vast quantity of carotenoids is mainly stored in leaves, algae, bacteria, phytoplankton and zooplankton. However, despite their wide distribution, de novo synthesis has so far been limited to certain microorganisms, fungii, algae and higher plants. Animals, by contrast, depend totally on a dietary intake for their supply of carotenoids since they are only capable to modify the different carotenoids by processing them by digestion.
[0005] Carotenoids are terpenoid compounds that besides their typical pigmenting characteristics (yellow, orange or red pigments), function as precursors of molecules with biological activity intervening in different vital biological and physiological processes.
[0006] Over 800 different carotenoids have been recognized in nature. Carotenoids are classified in two major groups: carotenes, that are hydrocarbon molecules comprising atoms of carbon and hydrogen only. Representative examples of carotenes include β-carotene and lycopene. And xanthophylls, which are oxygenated derivatives of the carotenes. Representative examples of xanthophylls include lutein, zeaxanthin, astaxanthin, capsanthin and cantaxanthin.
[0007] In plants and animals, carotenoids are subject—after synthesis or ingestion—to diverse processes and structural modifications. The carotenoid distribution, as well as the metabolic pathways have been widely studied by previous investigators (Goodwin, 1984; Davies, 1985)
[0008] It has been recognized that many aquatic species require an optimum level of carotenoids in their diet in order to properly carry out vital biological, metabolic and reproductive functions (Olson 1993; Weiser and Korman 1993; Bendich 1994; Krinsky 1994).
[0009] The biological properties of carotenoids have been studied by different investigators (Torrisen et al.. 1989; Meyers and Latscha 1997) as source of Vitamin A, for its antioxidant properties, for its capacity of enhancing the immunological response and stabilization of the cellular membranes and for its capacity of functioning as oxygen reservoirs in some intracellular reactions, and generally in the oxygenation of cells and tissues (Torrisen 1989; Craik 1985; Grung et al. 1993; Watson and Earnest, 1993). Other research studies demonstrate the critical role played by Astaxanthin in marine tropic processes, regarding the conversion of β-Carotene into Astaxanthin through crustacean zooplankton feeding (Ringelberg 1980; Kleppel 1988).
[0010] Besides the many functions that provitamin A has in the metabolism of animals, carotenoids are also involved in a number of further physiological functions. Of particular interest in this regard is the beneficial effect of carotenoids on the endocrine system with respect to gonadal development and maturation of fertilization, of hatching, viability and growth, particularly in fish and crustaceans (Deufel, 1965, 1975; Hartmann et al., 1947,; Meyers, 1997) and on the reproductive processes in a variety of many animal classes and species, e.g. birds, cattle, horses and pigs (Bauernfeind, 1981). Although the specific role of carotenoids has not been established in detail during embryogenesis and vitelogenesis, some authors suggest that a good level of carotenoids help protect the embryos nutrient reserves from oxidation and sunlight damage (UV radiation) (Nelis et al., 1989).
[0011] The major pigment in most aquatic animals is Astaxanthin, but they differ fundamentally in their ability to synthesize this highly oxidized carotenoid from precursors. The crustaceans (omnivorous, lower order animals with a highly developed biosynthetic capability) are able to convert various algal carotenoids (e.g. lutein and zeaxanthin) and Beta-carotene into the major pigment, Astaxanthin. This carotenoid primarily occurs as protein complexes of free, mono- and diesters in the exoskeleton of most crustaceans (Meyers, 1986).
[0012] Astaxanthin is found as a major pigment in certain plankton forms, and numerous fishes (e.g. salmonids) and crustaceans. Besides its role as a pigment, Astaxanthin also has a number of metabolic functions, of which the most significant are probably its effects on reproduction and its provitamin A (Schiedt et al., 1985).
[0013] It has been established that Astaxanthin plays an important physiological function by acting as a chelating agent, or free radical quencher, of toxic metabolites produced at the intracellular level, and its potency is described as many times more efficient than Vitamin E (Miki, 1991). Several research studies report that the formation of carotenoproteins and carotenolipoproteins positively affects the cell membrane wall (Bendich, 1989; Prabahla et al., 1989; Menasveta, 1993).
[0014] The immunological system of crustaceans is very primitive, and basically it functions by means of hemocytes that function either as fagocytes, encapsulators, aglutinators or lysing invasive exogenous agents.
[0015] Crustaceans are omnivores and feed on phytoplankton and zooplankton. From the evolutionary point of view it is not surprising that these animals show a broader metabolic diversity than do fish and birds to modify their dietary carotenoids to suit their tissue-specific molecules (Schiedt, 1998)
[0016] In the natural environment phytoplankton and zooplankton are the source of Astaxanthin and Astaxanthin precursors for those organisms that follow in the feeding chain, such is the case of fishes and crustaceans. However, nature cannot provide the required amounts for aquaculture operations, and even less in intensive operations; it is therefore recommended the use of Astaxanthin in artificial diets as a supplement (Meyers and Latscha, 1997).
[0017] Today's intensive production methods which have developed to keep pace with requirements and quality standards result in a situation in which natural pigment sources can no longer provide an adequate carotenoid supply. Nowadays, the appropiate pigmentation of products demanded by consumers usually requires pigment additives.
[0018] Although carotenoid effects in crustaceans have been widely studied and documented, and there is ample evidence of their presence in many microalgae, fungii and bacteria in most marine waters, all previous efforts to supplement Astaxanthin in crustaceans have been devoted to incorporate in the feeds Astaxanthin from various sources, either obtained synthetically—Carophyll Pink (Roche, BASF)—or from natural sources ( Haematoccocus pluvialis, Phaffia rhodozyma , shrimp meal, etc), but no known effort has been made to administer an optimum level of Astaxanthin precursors such as Zeaxanthin, and even more specifically a Zeaxanthin derivative.
[0019] The method of the present invention comprises the dosing of Zeaxanthin and Lutein concentrates, marigold oleoresin, marigold meal and Zeaxanthin and Lutein Short Chain Diesters like diacetates or dipropionates, derived from Tagetes erecta, to crustacean feeds that noticeably increase the survival rate and the growth rate of populations raised in captivity.
SUMMARY OF THE INVENTION
[0020] It is therefore a main object of the present invention to provide a method for increasing the survival rates of crustaceans by dosing a Carotenoid extract derived from marigold with a content of Zeaxanthin or Zeaxanthin Short Chain Diesters that comprise from 10 % to 90 % of the total xanthophylls, to the feed of a population of crustaceans.
[0021] It is also a main object of the present invention to provide a method of the above disclosed nature in which the carotenoid concentrate is readily and efficiently converted into Astaxanthin by crustaceans.
[0022] It is an additional purpose of the present invention to provide a method of the above disclosed nature in which the carotenoid concentrate noticeably improves the health condition of a crustacean population in such a way that the growth rate is increased.
[0023] It is yet a main object of the present invention to provide a method of the above disclosed nature in which the carotenoid concentrate acts as a precursor of Vitamin A .
[0024] It is a further object of the present invention to provide a method of the above disclosed nature in which the carotenoid concentrate stimulates the immunological system of a crustacean population.
[0025] It is another main purpose of the present invention to provide a method of the above disclosed nature in which the carotenoid concentrate increases the survival rate of a crustacean population.
[0026] It is yet a main object of the present invention to provide a method of the above disclosed nature in which the carotenoid concentrate is readily converted into Astaxanthin by crustaceans and consequently improves the color of such population.
[0027] It is a further object of the present invention to provide a method of the above disclosed nature in which the Astaxanthin precursor is readily and efficiently converted by crustaceans into Astaxanthin by which there are obtained similar benefits than dosing more expensive sources of Astaxanthin to the crustacean feeds.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1 is a graph showing Post-larvae survival of L. vanname under various feeding treatments including Hi-Zea.
[0029] FIG. 2 is a graph showing Astaxanthin concentration in micrograms per gram of body mass on different body parts of juveniles of L. vannamei.
[0030] FIG. 3 is a graph showing Astaxanthin concentration on different body parts of pre-adults of L. vannamei.
[0031] FIG. 4 is a graph showing the effect of carotenoid level on survival of shrimp in the presence of WSSV, IHHNV, and TSV infections.
DETAILED DESCRIPTION OF THE INVENTION
[0032] The following examples illustrate the benefits obtained by dosing a carotenoid concentrate rich in Zeaxanthin or in Zeaxanthin Short Chain Diesters (Hi-Zea) to crustacean feeds. Such results were obtained in a series of experiments and evaluations carried on at aquaculture laboratories, experimental farms, and commercial operations.
[0033] Zeaxanthin concentrates and Zeaxanthin Short Chain Diesters concentrates were prepared according to the processes described in U.S. Pat. No. 5,523,494 and U.S. Pat. No. 5,959,138.
[0034] The Zeaxanthin concentrate, or the Zeaxanthin Short Chain Diester concentrate, were incorporated in all instances as a powder carried in a premix, or in beadlets form, or microencapsulated with gelatin or carbohydrates or starches, or as an oil dispersion that readily mixes with the other feed ingredients; and were fed as crumbles, or pellets of different sizes, according to the crustacean requirements. The Zeaxanthin or the Zeaxanthin Short Chain Diesters concentrates are very stable and losses due to heat treatment during the feed preparation were minimal.
[0035] The content of Zeaxanthin or Zeaxanthin or Zeaxanthin Short Chain Diesters in the feeds, were analyzed for total xanthophylls at each experiment, and every time that a new feed lot was prepared, following the AOAC Spectrophotometric Method of Analysis (A.O.A.C., 1984, 14 th Edition).
[0036] The concentration of total pigment in crustacean specimens extract was carried out by UV/VIS spectrophotometric methods measurement absorbance at 470 nm (A 1%=2100 in Hexane).
[0037] The analysis of free, mono and diester-Astaxanthin, β-carotene, lutein, and zeaxanthin were quantified by HPLC on a H 3 PO 4 modified silica gel column.
[0038] The Astaxanthin enantiometers deposited by the crustaceans specimens, or from its different organs, were quantified by HPLC after derivatization into the corresponding dicamphanates (Vecchi and Muller 1979).
[0039] The Zeaxanthin and the Zeaxanthin Short Chain Diesters have the following chiral composition: 3R, 3′R Zeaxanthin min. 20% and 3R,3′S Meso Zeaxanthin max 80%.
[0040] The Astaxanthin deposited by shrimp which received feed enriched with synthetic Astaxanthin (Carophyll Pink) have the following chiral composition in the deposited Astaxanthin:
[0000]
3R,3′R Astaxanthin (Cis + Trans):
15.1%
3R,3′S Meso-Astaxanthin (Cis + Trans):
37.6%
3S,3′S Astaxanthin (Cis + Trans):
47.3%
[0041] The Astaxanthin deposited by shrimp which received feed enriched with the Zeaxanthin and the Zeaxanthin Short Chain Diesters have the following chiral composition in the deposited Astaxanthin
[0000]
3R,3′R Astaxanthin (Cis + Trans):
15.8%
3R,3′S Meso-Astaxanthin (Cis + Trans):
38.2%
3S,3′S Astaxanthin (Cis + Trans):
45.9%
EXAMPLES
[0042] The following examples illustrate the beneficial effect of the inclusion of a Zeaxanthin Concentrate or Zeaxanthin Diester Concentrate obtained from a natural source, and from now on called Hi-Zea, in the feed of shrimp at different stages of their life cycle. These examples are presented for illustrative purposes only and for a better understanding of the invention. However, they are not intended to limit the scope of the present invention.
Example 1
[0043] 1.—Dietary effect of the inclusion of Hi-Zea in the feed of a white shrimp Litopenaeus vannamei postlarvae (pl 7) cultivation.
[0044] An experiment was carried out with 6 treatments and three repetitions where white shrimp L. vannamei postlarvae (pl 7) were fed during 11 days with six different feed strategies. Treatments I to III included artemia nauplii. Besides artemia, Treatment TI was provided with commercial feed (40% protein). Treatment TII was supplemented with a commercial feed containing 138 ppm of xanthophylls, by including Hi-Zea in the formulation. Treatment TIII was provided with a microencapsulated commercial brand feed. Treatments IV to VI were provided with the same feed, but without artemia nauplii.
[0045] It can be observed in the graph of FIG. 1 that the Treatments including artemia nauplii (I to III), as well as those that did not include artemia (IV to VI), the experimental populations that were fed with Hi-Zea had a noticeable improvement in their survival (ANOVA 0.05%)
Example 2
[0046] 2.—Effect of dosing (Hi-Zea) in the feed of pre-juvenile (0.115 g) white shrimp Litopenaeus vannamei , grown under high density conditions.
[0047] An experiment was carried out comprising two treatments and three repetitions where pre-juvenile white shrimp L. vannamei were grown during 7 weeks, seeded at a high density (330 specimens/m 2 ) in order to create a stress condition. In Treatment I a commercial feed was provided (40% protein). In Treatment II the commercial feed (40% protein) contained 138 ppm of xanthophylls from Hi-Zea.
[0048] As can be observed in Table I, the average weight as well as the average survival rate was significantly larger (ANOVA 0.05%) when Hi-Zea was used, as compared against those individuals that did not receive the carotenoid dose.
[0000]
TABLE I
Final individual average weight and percentage of survival on Pre-
juveniles of L. vannamei .
Final average weight (g)
Survival %
Treatment I (Control)
2.02
66.6
Treatment II (Hi-Zea)
2.63
73.1
Example 3
[0049] 3.—Dietary effect of dosing different concentrations of Hi-Zea in the feed of juvenile (2.5 g) white shrimp L. vannamei . Survival rate, growth, and pigmentation (astaxanthin deposition).
[0050] An experiment was carried out by triplicate, on an experimental stock of L. vannamei juveniles, being treated under different feeding strategies. On treatment I (Control) commercial feed with 35% protein was used, according to DICTUS formulation. On treatment II, Hi Zea was added to obtain a xanthophyll concentration of 58.7 ppm. On treatment III Hi Zea was added to obtain a xanthophyll concentration of 104.7 ppm.
[0051] After 30 days in the experimental ponds, the specimens were collected. Survival rate was determined to be significantly higher (ANOVA 0.05%) on experimental ponds treated with Hi Zea (Table II).
[0000]
TABLE II
Juvenile survival of L. vannamei .
TIII (105 ppm Hi-
TI
TII (60 ppm Hi-Zea)
Zea)
Survival %
88
95
97
[0052] According to HPLC analysis, the Astaxanthin deposit on different body parts increased with relation to the Hi Zea level contained in the diet. Concentrations achieved on experimental Treatment III were significantly higher (ANOVA 0.05%) than those achieved on Treatments I and II (Graph of FIG. 2 ).
Example 4
[0053] 4.—Dietary effect of dosing of Hi Zea to feeds, at different dosages and over different feeding periods, on the survival rate and pigmentation of white pre-adult (17.0 g) shrimp L. vannamei.
[0054] An experiment was carried out by duplicate of three treatments, consisting of a two-way design, to analyze the combined effect of different xanthophyll levels on feeds and feeding periods on the survival rate and pigmentation of Pre-adult white shrimp.
[0055] Treatment I considered as a feeding control was based on a diet having a protein content of 35%, according to DICTUS formulation. Experimental Treatment II feed had a protein content of 35% and Hi Zea for increasing xanthophyll concentration to 58.7 ppm; and treatment III also had a protein content of 35% with the addition of Hi Zea for increasing xanthophyll concentration to 104.7 ppm
[0056] On Treatments I, II and III, experimental feeds were provided for 30 days. Afterwards the shrimp were collected.
[0057] Diets provided on treatments IV, V and VI are equivalent to those diets provided on treatments I, II and III accordingly, but were fed for a period of 60 days, after which the shrimp were collected.
[0058] Survival rate on shrimps treated with Hi Zea was significantly higher (ANOVA 0.05%) than control treatments, for both feeding periods of 30 and 60 days. Results are shown on Table III.
[0000]
TABLE III
Pre-adult Survival of L. vannamei .
TI (Control)
TII (60 ppm Hi-Zea)
TIII (105 ppm Hi-Zea)
% S/Day 30
93.3
96.7
100
% S/Day 60
80.0
93.3
100
[0059] According to HPLC analysis, the concentration of Astaxanthin on different body parts, after 30 days feeding period, were not significantly different (ANOVA 0.05%) between the three treatments. Although, after 60 days feeding period, concentrations of Astaxanthin on Cephalothorax and Abdomen on treatments II and III were significantly higher (ANOVA 0.05%) than those of treatment I. The Carapace Astaxanthin concentration on treatment III, was significantly higher (ANOVA 0.05%) than those of treatments I and II.
[0060] Astaxanthin concentrations recorded after the 60 days feeding period were higher than those obtained after the 30 days feeding period.
[0061] The results obtained, surprisingly show that there was a noticeable improvement in the survival rate by incorporating the Zeaxanthin Concentrate HiZea in the feed of shrimp as shown in the graph of FIG. 3 .
Example 5
[0062] 5.—Dietary Supplementation with Hi-Zea to determine Survival Rate of Litopenaeus vannamei in a shrimp farm in the presence of WSSV
[0063] Although white spot syndrome virus (WSSV) has had a devastating economic effect on shrimp farming, variability in the severity of outbreaks that can be correlated to seasonal and environmental factors suggests an interaction between the disease and stress factors. In some cases, shrimp can survive exposure to WSSV, but the presence of stress factors can cause an acute outbreak of the disease. Treatments or management strategies that can improve the condition of shrimp can potentially increase resistance to disease, and maintain chronically infected shrimp without massive mortalities. Treatments that improve the condition of shrimp populations may increase resistance to disease and enable commercial operations to maintain chronically infected populations without massive mortalities.
[0064] The effect of dosing a Zeaxanthin Short Chain Diester Concentrate (Hi-Zea) to the feed of Litopenaeus vannamei on its growth and survival rates was evaluated in a grow out trial at Biocultivos Manabitas in Bahia de Caraquez, Manabi, Ecuador under conditions where the shrimp were exposed to WSSV, TSV, and IHHNV. High mortality during the trial was anticipated. To eliminate the effects of inter pond variability, the grow out trial was conducted in 100, 1 m 2 bottomless cages in a single 0.32 hectare pond. In each cage, a 5 cm diameter directional airlift provided aeration and vertical water movement within the cage, and horizontal movement between the inside and outside of the cage. Shrimp (5.5 g at stocking) were stocked in the cages at densities of either 20 or 40 shrimp m −2 . Shrimp (3.7 g at stocking) were stocked outside the cages at a density of 8.2 shrimp m −2 . Prior to stocking, shrimp had been reared from PL in lined ponds, and had survived exposure to WSSV. Water treatment during filling and the eight week growth trial were similar to that used for surrounding commercial culture ponds.
[0065] Shrimp were fed 0.20 g feed shrimp −1 day −1 inside the cages and 0.14 g feed shrimp −1 day −1 outside the cages. For shrimp inside the cages, feeds with three different content levels of Hi-Zea were compared to a feed without any content of Hi-Zea. For shrimp outside the cages, the feed without Hi-Zea was used. Proximate and carotenoid analyses of the feeds are shown in table 1. The Feed was provided in the form of pellets and were provided to the cages 5 times a day. Hi-Zea was mixed with fish oil and sprayed on the pellets after drying. Shrimp were fed with the experimental feeds for the first 23 days of the growth trial. After analyzing the feeds, it was found that carotenoid levels were below target levels in the feeds having 150 and 225 ppm, the content levels were corrected by spraying additional Hi-Zea on the pellets. The feed having the correct amount of 150 ppm was provided for the remaining of the trial days (days 24-56). The feed having the correct amount of 225 ppm feed, which was used for days 24-35, was still below the target level. The carotenoid level was corrected again and used for the remainder of the trial days (days 36-56).
[0000]
TABLE 1
Proximate Analysis and Carotenoid Content of Feeds
Feed (ppm carotenoid)
0
75
150
225
Proximate analysis (%)*
Protein
30
34
36
36
Lipid
5
9
9
8
Fiber
3
2
2
2
Ash
9
8
8
8
Carotenoid (ppm)**
June 1–23
13
67
108
96
June 24–July 5
18
68
142
186
July 6–27
18
68
142
232
*Laboratorio de Alimentos, Medicamentos y Toxicologia, Universidad Autonoma de Nuevo Leon, San Nicolas de Los Garza, N. L., Mexico
**Research and Development Department, Industrial Organica, S. A., Monterrey, N. L., Mexico
Growth and Survival
[0066] Growth and survival at harvest was analyzed by a two-way variance analysis. Interactions between stocking density and diet were not significant for either growth or survival (P=0.5147 and 0.4515, respectively).
[0067] Survival ( FIG. 1 ) was greater at the stocking density of 20 shrimp/m 2 than at 40 shrimp/m 2 (P=0.0001). At 20 shrimp/m 2 , survival ranged from 21 to 70%, and at 40 shrimp/m 2 , ranged from 7 to 39%. At both stocking densities, survival was greater for the fed shrimps than for the unfed shrimp (P=0.0001). At both stocking densities, survival was greater with the feed containing Hi-Zea than with the feed without Hi-Zea (P=0.0005). Differences in survival between feeds containing Hi-Zea were not significant (P=0.2458).
Pathological Analysis
[0068] At harvest, there was sampled hemolymph from the shrimp fed containing from 0 to 150 ppm of carotenoid at the stocking density of 20 shrimp/m 2 for pathological analysis. PCR tests for IHHNV and WSSV, and immune-blot dot tests for IHHNV, WSSV, and TSV indicated high levels of infection by all three viruses in both groups of shrimp.
[0069] The growth trial demonstrated that the dosing of Zeaxanthin Short Chain Diester Concentrate (Hi-Zea) surprisingly increased the survival of shrimp in the presence of WSSV, IHHNV, and TSV infections as shown in the graph of FIG. 4 .
Example 6
[0070] 6.—Effects of different sources and doses of carotenoids in the balanced feed, growout, survival, and deposition of pigments in white shrimp L. vannamei.
[0071] The following is a review of the results obtained regarding the dosing of Hi Zea in the feed, as compared to feed that contained synthetic Astaxanthin (Carophyll Pink). The average survival and final weight results of the experimental work with shrimp L. vannamei results, obtained after a 60 day treatment, are shown in the following table:
[0000]
FINAL WEIGHT
ASTAX. IN
ASTAX. IN
ASTAX. IN
TREATMENT
grs
SURVIVAL %
HEAD*
MUSCLE*
SHELL*
Control
7.55
61.11
27.4
9.3
50.4
ROCHE
7.77
63.33
29.3
11.6
80.8
Astaxanthin
75 ppm
Hi Zea
7.94
65.55
40.3
16.3
71.6
75 ppm
Hi Zea
7.82
81.11
37.7
14.3
72.3
100 ppm
Hi Zea
7.81
78.89
45.7
11.9
76.0
200 ppm
*micrograms of astaxanthin per gram of tissue in the head (hepatopancreas), muscle and shell (carapace)
[0072] Differences observed on the final weights were not statistically significant. On the other hand, survival rates were statistically significant, and their value increased in direct ratio to the increment of Hi Zea dosage.
[0073] Astaxanthin deposition using 75 ppm of Hi Zea was similar to that obtained with 75 ppm of synthetic Astaxanthin, differences observed were not statistically significant in any of the three body parts analyzed by HPLC.
[0074] This indicates that Hi Zea is efficiently incorporated on the different tissues and body parts, and the energetic cost of this metabolic change is definitely despicable, as it is not reflected statistically on the growth performance.
Example 7
[0075] 7.—Comparison of the different Astaxanthin enantiomers deposited by P. monodon that were given the following three different diets: commercial feed as control; commercial feed containing 120 ppm of Zeaxanthin Short Chain Diester Concentrate (Hi-Zea); and commercial feed that contained 60 ppm of synthetic Astaxanthin (Carophyll Pink).
[0076] An evaluation was carried on a commercial operation to determine the effect of feeding P. monodon shrimp with the same commercial feed that contained:
a) no extra carotenoid, b) 120 ppm of Hi-Zea, and c) 60 ppm of synthetic Astaxanthin (Carophyll Pink)
[0080] The specimens were seeded at 30/m 2 , pl 7, in aerated and lined ponds. The ponds sizes were 0.25 Ha each.
[0081] Five ponds selected at random were fed with the feed containing no added carotenoid.
[0082] Five additional ponds, randomly selected were given feed containing 120 ppm of Hi-Zea, and
[0083] Another five ponds located at random, were given feed containing 60 ppm of synthetic Astaxanthin (Carophyll Pink)
[0084] All ponds were seeded the same date with pl of the same origin. Water quality was uniform, as well as the fertilization and management of the ponds. Natural production of phytoplankton and zooplankton was abundant in all the ponds.
[0085] At three grams weight, the ponds were sampled, the specimens were lyophillized and the dehydrated samples were ground and analyzed.
[0086] The concentration of total pigment in the crustacean specimens extract was carried out by UV/Vis spectrophotometric methods measurement absorbance at 470 nm (A 1%=2100 in hexane).
[0000] The results obtained were as follows:
[0000]
Ponds with Hi-Zea treatment:
179.4 ppm
Ponds with Carophyll Pink:
153.6 ppm
Control ponds:
153.1 ppm
[0087] The analysis of Astaxanthin R/S enantiomers deposited by the crustacean specimens, were quantified by HPLC after derivatization into the corresponding dicamphanates (Vecchi and Muller 1979), in order to differentiate the Astaxanthin enantiomers. The results were as follows:
[0000]
Control Ponds:
3R,3′R Astaxanthin (Cis + Trans):
14.2%
3R,3′S Meso-Astaxanthin (Cis + Trans):
37.2%
3S,3′S Astaxanthin (Cis + Trans):
48.5%
Ponds with Hi-Zea treatment:
3R,3′R Astaxanthin (Cis + Trans)
15.8%
3R,3′S Meso-Astaxanthin (Cis + Trans):
38.2%
3S,3′S Astaxanthin (Cis + Trans):
45.9%
Ponds with Carophyll Pink treatment:
3R,3′R Astaxanthin (Cis + Trans):
15.1%
3R,3′S Meso-Astaxanthin (Cis + Trans):
37.6%
3S,3′S Astaxanthin (Cis + Trans):
47.3%
[0088] As it can be observed, there is no statistical difference in the proportion of the different Astaxanthin enantiomers deposited by P. monodon in any of the three different treatments.
[0089] The above suggests that P. monodon shrimp have the capability to convert and deposit the Zeaxanthin precursor contained in the Hi-Zea; as well as the precursors found in the phytoplankton and zooplankton of the control ponds; as well as the Astaxanthin contained in the Carophyll Pink. In all three instances, the crustacean showed the capability to provide identical depositions, starting from different sources and following a unique metabolic pathway. To our knowledge, there is no report of such discovery. | 4y
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to bioerodible polymers containing a biologically active substance which is released when the polymer is brought into contact with a body fluid, thus releasing the biologically active material gradually and over a period of time. More particularly, this invention relates to such products in which the bioerodible polymer is sensitive to acidic media whereby control of the rate of erosion, and hence the rate of release of the biologically active substance can be controlled.
2. Description of the Prior Art
In U.S. Pat. No. 4,093,709 there are described bioerodible polymers intended to contain drugs for release as the polymer is eroded by contact with body fluids, such polymers being poly(ortho esters) or polycarbonates. A typical such polymer has the formula ##STR1## See also U.S. Pat. Nos. 4,131,648; 4,138,344 and 4,180,646.
Another class of bioerodible polymers suitable for the same purpose is described in U.S. Pat. No. 4,304,767 (the '767 Patent). These polymers are formed by a condensation reaction of a ketene acetal with a polyol and they have certain advantages over those of the U.S. Pat. No. 4,093,709, such as the fact that their production is not accompanied by the formation of low molecular weight by-products such as alcohol and the reaction proceeds rapidly and at ambient temperature. The absence of formation of small molecular weight by-products enables one to produce dense crosslinked materials incorporating a drug.
It has been proposed to employ bioerodible polymers for the gradual release of drugs, such polymers being sensitive to the pH of the ambient medium. See, for example, a paper by Heller et al. in the Journal of Applied Polymer Science, Vol. 22, pp. 1991-2009 (1978). These polymers are partial esters of methyl vinyl ether-maleic anhydride copolymers which have been reacted with alcohols to form polymers that contain both carboxylic acid and carboxylic ester functionalities.
In these polymers, the size of the alkyl group in the ester functionality determines the rate at which the polymer erodes at a constant external pH. Most importantly, any particular polymer exhibits a very pronounced dependence of erosion on the external pH and even very small changes in this external pH have a very large effect on rate of polymer erosion.
An approach to utilizing this methodology is described in a paper by Heller and Trescony in Journal of Pharmaceutical Sciences, Vol. 68, pp. 919-921 (1979). A polymer similar to those of the cited Heller and Trescony paper containing a drug is coated with a hydrogel containing urease. When exposed to a solution containing urea, the urease in the hydrogel acts on the urea, which infuses into the hydrogel, thus releasing ammonium bicarbonate and ammonium hydroxide. This accelerates erosion of the bioerodible polymer and hence accelerates release of the drug, e.g., hydrocortisone.
SUMMARY OF THE INVENTION
It is an object of the invention to provide superior bioerodible polymers which are pH sensitive and respond to media having an acidic pH.
It is a further object of the invention to provide products incorporating a bioerodible polymer containing a biologically active ingredient which is released as the polymer undergoes erosion, such product being sensitive to acid pH, whereby under acid conditions the rate of erosion of the polymer and release of the biologically active material is controlled by the pH.
The above and other objects will be apparent from the ensuing description and the appended claims.
We have discovered that bioerodible polymers such as those described and claimed in U.S. Pat. No. 4,304,767 can be modified to render them highly pH sensitive in a desired acid range whereby the rate of erosion, hence the rate of drug release, can be controlled by the pH of the surrounding medium. Such modification is brought about by including in the polymer an amine functionality. This method is applicable also to other bioerodible polymers such as those of U.S. Pat. Nos. 4,093,709; 4,131,648; 4,138,344 and 4,180,646. The preferred polymers are those of U.S. Pat. No. 4,304,767 (the '767 Patent).
DETAILED DESCRIPTION OF THE INVENTION
The Preferred Bioerodible Polymers
The preferred bioerodible polymers are those described in U.S. Pat. No. 4,304,767, such description being incorporated herein by reference in its entirety. Briefly stated, two types of ketene acetal monomers are described as follows: ##STR2##
The Type I monomers are condensed with polyols to afford Type I polymers which, when the polyol is a diol R(OH) 2 have the linear structure ##STR3## If the polyol is a triol or polyol of higher functionality, or if a ketene acetal having a functionality of three or more is used, then the Type I polymer is a cross-linked polymer.
The Type II monomers, when reacted with diols R(OH) 2 , afford Type II linear polymers, having the structure ##STR4## As in the case of the Type I polymers if the polyol or the ketene acetal has a higher functionality than two, crosslinking occurs.
As starting materials for the preferred embodiment of the invention, any of the ketone acetals of Type I or Type II and any of the polyols described in the '767 Patent may be employed. For example, any of the diketene acetals described in the literature which is cited at column 4, line 33 to column 5, line 3 of the '767 Patent may be used and any of the polyols described in column 6, line 52 to column 7, line 66, may be used provided they are compatible with the purpose of the present invention, namely the introduction of an amine functionality into the polymer and the endowment of pH sensitivity in the acid range to the polymer. Type I diketene acetals are preferred.
We have found that by incorporating in the poly(ortho esters) of the '767 Patent an amine group, the pH sensitivity of the polymers in the acid range is altered. That is, the rate of erosion of the polymer, hence the release of a biologically active substance in the polymer, can be modified and controlled.
An amine group can be introduced into the polymer in various ways such as the following:
As stated above and as described in the 767 Patent, the Type I and Type II polymers are prepared by condensing a Type I or a Type II diketene acetal (or a ketene acetal of higher functionality) with a polyol. The amine functionality of the present invention may be incorporated in the ketene acetal or in the polyol or in both, such that when the ketene acetal and the polyol are reacted a polymer results which contains one or more types of amine groups.
If the amine group is incorporated in the ketene acetal, it may be incorporated, for example, in the ○R group of Type I or in the R" group of Type II monomer. Preferably, however, the amine group is incorporated in a prepolymer which is prepared by reacting a ketene acetal with a diol R(OH) 2 in which R contains an amine group. The prepolymer has the general formula 3 set forth in the reaction scheme below. ##STR5##
This prepolymer is then reacted with a polyol R x (OH) n to produce a polymer which, if n=3 or more, is cross linked ##STR6## If (as is preferred) the polyol in reaction I is a triol or a polyol of higher functionality, the polymer 4 is crosslinked. Polymer 4 is written for a triol R 6 (OH) 3 . The formula will be apparent for higher polyols and for diols.
The preparation of such a prepolymer is preferred because a biologically active agent can be conveniently incorporated in the prepolymer and will, therefore, be incorporated in the polymer 4. This is especially advantageous where the polymer is crosslinked because the biologically active agent may be uniformly mixed with or dissolved in the prepolymer, hence will be uniformly incorporated in the polymer.
If the ketene acetal is of Type II, the same procedure (forming a prepolymer containing an amine group in the linking group which links two ketene acetal moieties) may be used. The prepolymer will have the structure ##STR7## The polymer will have the structure ##STR8## and will be crosslinked if the polyol R x (OH) n used in the polymerization reaction is a tri- or higher polyol.
Alternatively a Type I or Type II di- (or higher) ketene acetal may be polymerized with a polyol which contains an amine group. The polymer will be of Type I or Type II as shown above but with an amine group incorporated in the R x group derived from the polyol.
In the formulae above the R's may be the same or different, and they may be hydrogen or essentially hydrocarbon groups (with amine functionality if desired). The group ○R is a quadrivalent group which is essentially hydrocarbon. R, R x and R y are bivalent essentially hydrocarbon groups, preferably having an amine functionality in the case of R. R x also preferably contains an amine functionality. The groups R, ○R , R x and R y may contain hetero atoms (e.g. nitrogen in the form of an amine group) provided the hetero atom or group does not interfere with polymerization, does not interfere with erosion and does not interfere with the intended pH sensitivity of the polymer. R - - - R signifies that the R's may be separate groups or may together form parts of a cyclic group.
The following specific examples will serve further to illustrate the practice of the present invention.
EXAMPLE 1
The diketene acetal 3,9-bis (ethylidene 2,4,8,10-tetraoxaspiro [5,5] undecane (7) was reacted with the linker N-butyldiethanolamine (8) to form a prepolymer 9 which was then reacted with the polyol 10 to form a crosslinked polymer 11. The reaction scheme was as follows: ##STR9##
The reactions were carried out as follows: in a 120 ml round bottom flask equipped with a paddle stirrer and argon inlet and outlet was placed 15 g (0.0703 mole) of 7 and 5.67 g (0.0352 mole) of 8. The reaction was initiated by addition of 0.1 ml of iodine in pyridine solution (0.1 g/100 ml). After one hour the reaction is complete.
Crosslinked polymers were prepared by taking 4 grams of the liquid prepolymer 11 and adding 1.5 g (0.0054 mole) of 10. After the viscous mixture is shaped to the desired form, it is cured at 70° C. for 18 hours.
EXAMPLE 2
Using the procedure described in Example 1, 15 g (0.0703 mole) of 7 was reacted with 4.19 g (0.0352 mole) methyldiethanolamine. The resulting prepolymer was crosslinked with triethanolamine.
EXAMPLE 3
Using the procedure described in Example 1, 15 g (0.0703 mole) of 7 was reacted with 5.17 g (0.0352 mole) of 3-diethylamino-1,2-propanediol. The resulting prepolymer was crosslinked with tri-isopropanolamine.
EXAMPLE 4
Using the procedure described in Example 1, 15 g (0.0703 mole) of 7 was reacted with 6.58 g (0.0352 mole) of cyclohexyl diethanolamine. The resulting prepolymer was crosslinked with 1,2,6-hexanetriol.
EXAMPLE 5
Using the procedure described in Example 1 15 g (0.0703 mole) of 7 are reacted with 4 g (0.0352) mole) of 1,6-hexanediol to form a prepolymer which is crosslinked with triethanolamine.
EXAMPLE 5a
Using the procedure described in Example 1, 15 g (0.0703 mole) of 7 are reacted with 8.33 g (0.0703 mole) of methyl diethanolamine. In this case, a high molecular weight, linear polymer is obtained.
EXAMPLE 6
In vitro testing of erosion and drug release
A marker drug, p-nitroacetanilide was mixed into the prepolymer to give a concentration of 2 wt%. After adding the crosslinker, the viscous mixture was extruded into a polyethylene tube having an inside diameter of 0.25 in. and cured at 70° C. for 18 hours. (However, if a sensitive therapeutic agent is used, lower cure temperatures and longer reaction times can be used.)
After the polymer has cured, the tube is sliced to produce disks having an approximate thickness of 0.030 in. and the outer shell from the polyethylene tube is removed. The disks are put into stainless steel mesh bags which are attached to stainless steel wires and vertically agitated at the rate of one stroke per second in 30 mls. of the appropriate buffer solutions in 40 ml. test tubes. The buffer solutions are made from citric acid and sodium dibasic phosphate for all ranges of pH. The test tubes are thermostatically controlled at 37° C.
The buffer solutions are changed and analyzed at the appropriate time intervals commensurate with the rate of release of the p-nitroacetanilide marker. The analyses are performed on a Model 554 Perkin Elmer spectrophotometer by reading the lambda max absorption at 318 nm and concentrations are calculated from a standard absorption curve.
EXAMPLE 7
Preparation of Hydrogel Device of FIG. 4
A disk containing insulin dispersed in the amine-containing poly(ortho ester) is prepared and a small locking forceps is affixed to the edge of each polymer disk so that it can be manipulated without touching the surfaces during the immobilized enzyme-coating procedure. A 30% aqueous solution of bovine serum albumin is prepared, and 1 g of glucose oxidase is added to 10 ml of this solution. After quick stirring to dissolve the glucose oxidase, the solution is chilled in an ice bath. Each disk is held horizontally by the attached forceps, and 1 drop of glucose oxidase solution is added to the upper disk face. The disk is quickly rotated, and a drop is added to the opposite face. Similarly, 1 drop of 25% aqueous glutaraldehyde is added to each face. One minute after the glutaraldehyde addition, the coating has gelled sufficiently to allow the disks to be hung vertically. This procedure immobilizes the glucose oxidase in the hydrogel.
After standing in air for 15 min., the coated disks are immersed in cold, deionized water for 15 min. in 0.1M glycine for 15 min, and in pH 5.75 phosphate buffer for 2 hr. Finally, they are immersed in fresh pH 5.75 phosphate buffer for 4 hr.
Referring now to FIGS. 1, 2 and 3 of the drawings, the test results of the procedure of Example 6 as applied to the polymers of Examples 1, 2 and 3 respectively are shown. The degree of erosion (as measured by the p-nitroacetanilide concentration) is plotted against time. The polymer of Examples 1, 2 and 3 were used with p-nitroacetanilide and the results are plotted in FIGS. 1, 2 and 3, respectively. It will be seen that with polymer 11 (Example 1) the rate of erosion was least at pH 4.5; it was greater at pH 4.0; and it was still greater at pH 3.5.
With the polymer of Example 2 the rate of erosion was low at pH 5.0 and 4.8, much greater at pH 4.2 and very much greater at pH 4.4 and 4.2. This is believed to be due to the fact that the polymer contained two amine functionalities, one in the linking group of the prepolymer and the other in the crosslinking moieties.
Similar results are shown in FIG. 3 (Example 3).
Referring now to FIG. 4, a device is shown which is generally designated by the reference numeral 10. It comprises a polymer 11 encased in a hydrogel layer 12. The polymer 11 is that of the present invention and it contains a drug or other biologically active substance, for example, insulin. The hydrogel layer 12 contains a substance which reacts with or upon a substance in the surrounding environment. For example, the hydrogel 12 may contain glucose oxidase fixed to the hydrogel as in Example 7. If the device is in contact with the blood of a diabetic person and if the glucose level rises, as after a meal, more glucose will diffuse into the hydrogel layer 12 and will be acted upon by the glucose oxidase to produce gluconic acid which will in turn diffuse into the polymer 11 thereby reducing its pH and accelerating erosion of the polymer and release of insulin, which will counteract the effect of rising glucose level in the blood.
Referring now to FIG. 5, the entire device 13 consists of a body 14 of polymer of the invention containing a drug or other biologically active substance. Using insulin as an example of a drug, the polymer 14 will contain insulin and glucose oxidase. The surface layer 15 illustrates the initial zone of reaction. As the glucose level in the surrounding medium, e.g., circulating blood, glucose is converted to gluconic acid which by decreasing the pH increases the rate of erosion of the polymer and the rate of release of insulin.
GENERAL DISCUSSION
It will be apparent that considerable variation in the reactants and resulting polymers and in other aspects of the invention may be practiced. An amine group may be incorporated in the polymer in various ways. The amine groups may be primary, secondary or tertiary. Examples of amines are as follows:
Diethanol Amine
N,N-Dihydroxyethyl aniline
Methyl diethanol amine
Diethanol propanol amine
Butyldiethanol amine
Propyl diethanol amine
Isopropyl diethanol amine
Cyclohexyl diethanol amine
N-Benzyl-N,N-diethanol amine
3-Dimethylamino-1,2-propanediol
3-Diethyl amino-1,2-propanediol
1,3-Bis[tris(hydroxymethyl)methylamino]propane
2,2-Bis(hydroxymethyl)-2,2',2"-nitriloethanol
3-(tert-Butylamino)-1,2-propanediol
N-phenyl diethanol amine
Triethanol amine
Tris(hydroxymethyl)aminomethane
Dihydroxyethyl piparizine
Tri-isopropanol amine
7-(2,3-Dihydroxypropyl)theophylline
3,6-Dihydroxy pyridazine
2,3-Dihydroxy pyridine
2,4-Dihydroxy pyridine
2,6-Dihydroxy pyridine
4,6-Pyrimidinediol
N-Ethyl diethanol amine
This list includes dihydroxy amines, trihydroxy amines, primary amines, secondary amines, and tertiary amines. The dihydroxy amines are preferably used as linking groups between the ketone acetal moieties, but they may be used to copolymerize with di- (or higher) ketene acetals, in the former case (diketene acetals) to form linear polymers. Preferably a dihydroxy amine is used to link the ketene acetal moieties and a tri- (or higher) hydroxy amine is used to cross link the resulting prepolymers.
In choosing an amine group, one may consider its basicity, the possible effects of substituents forming part of the amine group and the effect of other atoms and groups in the polymer such as steric effects.
In the formation of a prepolymer such as those of Examples 1, 2 and 3, a certain amount of the diol reactant (e.g. N-butyldiethanol amine of Example 1) may form small oligomers with the diketene acetal. However the amount of such small oligomers is not significant and the product, although it contains a small proportion of small oligomers, may be used without purification.
It will therefore be apparent that new and useful polymers, prepolymers, methods and fabricated products are provided. | 4y
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BACKGROUND OF THE INVENTION
Food storage refrigerators of conventional design present two major problems. The first arises because home refrigerators use energy at the times when the utility company that supplies that energy experiences its peak load. Most, if not all, utility power companies are called upon to supply energy at a much higher rate during some periods of the day than at other periods. Thus, for example, the mid-afternoon demand on a weekday may be several times the demand at night and on weekends. Suppliers of energy must provide facilities at major capital cost which are capable of meeting the peak demands for energy. The result is that costly energy conversion and distribution facilities operate at far below capacity much of the time. The cost of energy at the point of use is necessarily much greater than it could be if those facilities were used more efficiently. Further, under present and proposed time-of-day rates for electrical energy, the cost to the refrigerator owner of energy used during peak periods is several times greater than at other times.
For many energy suppliers, the energy used in home refrigerators represents a very significant part of the total load. Very substantial and important savings could be realized if the load represented by home refrigerators were to be shifted to periods of low demand. That can be, and has been, done by powering refrigerators from circuits that are simply de-energized during the supplying utilities' peak demand periods. However, that solution can result in spoiling of food and a health hazard with present refrigerator designs.
Inefficiency per se is the second of the two major problems presented by conventional refrigerator designs. In the conventional system, the entire refrigeration system, both refrigerant circuit and air flow circuit, is governed by sensing ambient air temperature within the refrigerator box. Each time the door is opened, the ambient temperature increases. Unless the period of door opening is very short, the temperature sensor will demand cooling, the compressor motor, which accounts for over 80% of the electrical energy required for refrigerators, will be turned on, and the in-rush current to the motor will be high. In that cycle, which may be repeated many times, there is energy waste in frequent start-up followed by a short interval running time. The result for the refrigerator owner is excessive use of energy resulting in higher cost. The national result is waste of a limited resource. Moisture control of condensation on the exterior of the refrigerator enclosure and of frost on the surface of the evaporator usually accounts for over ten percent of the electrical energy used in refrigerators. The conventional defrost control consists of a timer which, on a set time cycle, energizes an electric heater which removes frost by convective and radiant heating of the entire evaporator body to a temperature sufficient to melt the frost. Timing intervals and on periods of these systems are pre-set and must be based on defrosting under worst case conditions without regard to the actual presence or absence of frost, wasting energy. Similarly, heaters used to eliminate the moisture of condensation on the exterior of the enclosure operate on a set basis without regard for actual conditions, wasting energy. Past efforts to solve the efficiency problem in refrigerators have been directed primarily to providing better insulation, and to providing more efficient compressors and evaporators.
This invention reduces the total energy required for residential refrigeration and shifts the demand for the energy occurring during high-cost peak periods to other times of lesser demand and cost, and it provides that contribution in new dimensions.
The residential refrigerator requires sixteen percent of all of the oil imported into the United States from the Middle East. Test results demonstrate that this invention provides the potential to remove as much as twenty-five percent of that requirement.
SUMMARY OF THE INVENTION
The object of the invention is to increase the efficiency of refrigerator operation and to require the majority of energy used for refrigeration to be used at other than high-cost peak load periods. It is an object to provide significant increased efficiency both for the supplier of refrigeration energy and for the user of that energy. A related object is to provide a refrigeration system and a refrigeration method in which users, refrigerator manufacturers, utility companies and governmental agencies will all obtain clear advantages, and which all will be motivated to support and to adopt.
These objects and advantages, and others which will become apparent in what follows, are realized , in part, by the combination of the steps of producing and storing cold during the energy suppliers' non-peak load times with the step of releasing of that cold to accomplish refrigeration as required, but without use of the compressor during peak load high energy cost periods. To enable the practicing of that method, the conventional evaporator is replaced with an evaporator which provides for storage of cold and the conventional control method is replaced with a control system which manages separately the refrigerant circuit from the air flow circuit.
The air flow circuit in one preferred form includes a fan and ducting for causing air flow over the cold storage unit at selected times. The invention permits the employment of a conventional refrigerant circuit including a compressor, condenser and evaporator in a closed circuit in which the refrigerant circulates. To utilize that conventional circuit is one of the objects and advantages of the invention.
One of the major advantages, and one of the major objectives, of the invention is to recognize and accommodate the difference in the highly efficient, rapidly accomplished refrigerant circuit heat transfer, on one hand, and the much less efficient and more slowly accomplished airflow circuit heat transfer.
The method of the invention presents opportunity for a number of variations that contribute to optimization of energy saving. Thus, in a preferred form of the invention, cold is stored in a unit that is not a "good" thermal energy transfer unit until cold is required. Cold is extracted from cold storage by a positive action even during peak periods when compressor operation is not permitted. A new heat exchanger design in the preferred embodiment assures a high rate of heat transfer from the air to the evaporator contributing to the efficiency of the air flow circuit heat transfer portion of the system.
It is a feature of the invention to provide a means for anticipating the high energy cost peak load periods and to operate the compressor during the preceding low energy cost periods to assure adequate cold storage just prior to a high cost period.
In another refinement, a means is provided for preventing the simultaneous, or near simultaneous, turn on of many refrigerators at the end of the high cost peak load period of the energy supplier.
The invention further embodies a highly efficient method of defrosting the evaporator in which the energy required for the defrost function is a fraction of that required in conventional systems.
It is a feature of the design of the invention that the improved system may be installed in refrigerator enclosures now in production without major modification, assuring adoption and contribution of the system to the national energy conservation goal within a short time period at minimal cost.
Up to this point, only the compressed refrigerant type of refrigeration system has been mentioned. That type is almost always powered by electricity and, to the extent that the purpose of the invention is to satisfy the need for peak load relief, the invention is directed to that kind of refrigerator. However, there is another kind of refrigeration cycle in which input power is supplied as heat which causes a liquid to vaporize. In both kinds of refrigeration, refrigeration derives from the fact that evaporating liquids absorb heat and condensing gasses absorb cold. In the compression system, gasses are forcibly compressed, and in the heat input system, liquid is forcibly turned to gas. To the extent that the invention relates to increasing the efficiency of the refrigeration unit per se it is applicable to both kinds of refrigeration and local usage notwithstanding, "refrigerant" means the material that flows through either system and alternates between gaseous and liquid state.
While heat input refrigerators are much less popular for home refrigeration, they are widely used in recreational vehicles and boats. It is usually not preferred to operate a gas powered refrigerator while in motion, so a system is needed which can store cold and which can control cold production and cold untilization separately.
These and other advantages and summaries of the invention will become apparent in the specification which follows and from an examination of the drawings.
DRAWINGS
In the drawings:
FIG. 1 is a partly schematic, partly diagrammatic representation showing a preferred embodiment of the invention;
FIG. 2 is a schematic diagram, in expanded form, of the electrical elements of FIG. 1;
FIG. 3 is a diagram of an alternative form of control unit;
FIGS. 4, 5, 6 and 7 are graphs illustrating some of the possible modes of operation of the embodiment of FIG. 1;
FIG. 8 is an enlarged view, partly in cross-section, of elements of FIG. 1; and
FIG. 9 is an exploded view, partly in section, of fragments of the elements shown in FIG. 6.
DESCRIPTION OF PREFERRED EMBODIMENTS
The system arrangement of one preferred form of the invention is depicted in FIG. 1. That system includes a compressor 10, a condenser 12, and a combined evaporator and cold storage unit 14. The compressor is driven by a compressor motor 16 the power for which is supplied from an external power source represented by the block 18 through a power controller 20. The compressor 10, condenser 12, and the evaporator portion of the unit 14 are connected in series in a fluid circuit. The compressor delivers high-pressure gas refrigerant to the condenser 12 through a line 24. The function of the condenser is to dissipate the heat in the compressed gas refrigerant and to deliver cool liquid refrigerant by capillary line 26 to the evaporator conduit 28. The liquid is permitted to escape through an orifice or a metering valve. It expands and becomes a gas in the flow conduits 28 within the unit 14. Those conduits are represented by dashed lines. As the liquid expands to a gas in the evaporator conduits it draws heat from its surroundings, cooling them.
In this invention, the conduit 28 is surrounded by a medium whose particular property is the ability to store cold. That medium may be any one of a number of well known substances and is called the "core" material. One example is salt water; another is ethylene glycol solution. That cold storage medium is housed in an enclosure which, because of its design or its material, transfers heat into the storage medium, i.e. releases cold to the refrigerator space, at a relatively low rate until some special means is provided for increasing the rate of the heat input or cold output. Thus it is that the cold storage portion of unit 14 has a special character and function. On the other hand, the compressor 10, the condenser 12, and the compressor motor 16, and the evaporator element may have conventional design and, in this embodiment, do have conventional design.
A means is employed by which to increase the rate of cold output from the cold storage portion of the unit 14. In this embodiment, that means comprises a fan, or blower, 30 which, when operated, forces air to pass through an encompassing shroud 32. The shroud surrounds the unit 14. The shroud is fitted with a number of internal vanes, two of which have been numbered 34 for identification. Those vanes are a preferred form of a means for causing the motion of air over the unit 14 to be turbulent so that there is a greater degree of contact between that air and the surface of the unit 14. In this case, the vanes 34, or at least most of them, do not actually engage the surface of unit 14. They are not heat conduction fins. They are removed from significant heat conducting contact with unit 14 to avoid formation of ice at the junction between the fins and heat storage unit. The use of heat conduction fins is not foreclosed in the invention, but in this preferred embodiment they are not used.
In this embodiment a resistance wire is applied to the outer surface of the unit 14. It is arranged so that when energized it will melt quickly any frost which is in direct contact with its outer surface. The resistance wire is identified by the numeral 36. The energization path for the heater extends through a transformer 37 to the power controller 20.
A means is provided for measuring the quantity of cold that is stored in the cold storage portion of unit 14. Since the storage material has a fixed volume and mass, the quantity of cold stored within it can be determined simply by measuring its temperature, and that is what is done in this preferred embodiment. The temperature sensor 40 is disposed in temperature sensing relation to the cold storage medium and supplies a signal which is indicative of temperature to the power controller 20 by sensor lines 42.
The fan, or blower, 30 is powered through power controller 20 and supply lines which include, in series, a switch 46 and a switch 44 whose operation is controlled by a temperature sensor 47. That sensor senses the ambient air temperature within the refrigerator of which this system is a part, and it closes switch 44 when the ambient temperature rises above some preset level. The shroud 32, the evaporator and cold storage unit 14, the fan 30, the temperature sensor and a door switch 46 are all enclosed in a cold box or enclosure which is represented in FIG. 1 by the dashed line 50. The enclosure includes a door 52 which affords access to the interior of the enclosure from its exterior. Operation of that door operates the switch 46.
The exterior surface of a refrigerator may become sufficiently cold to condense moisture from the air in humid weather. It is common practice to include a heater element in the enclosure whose function is to heat the enclosure walls. Operation of the heater is controlled by a moisture sensor. The unit of FIG. 1 includes such a heater, case heater 38, and a moisture sensor 94. The power controller 20 of FIG. 1 is shown in expanded form in FIG. 2 together with some of the sensors, switches and other elements of FIG. 1. More particularly, the heater 36 and transformer 37 of FIG. 1 is represented by the block labelled "EVAPORATOR HEATER" and numbered 36. Also shown in FIG. 2 are the fan 30, the door 52, the door switch 46, the compressor motor 16, the ambient sensor 47, and its switch 44, the moisture sensor 97, the case heater 38, and the core temperature sensor which has an upper and lower limit. The remainder of the elements in FIG. 2 form the power controller 20. Power is applied to lines P-1 and P-2. That power is employed to operate clock 60. The clock is connected to a source of battery power 62 which supplies power automatically in the event that no power is available at lines P-1 and P-2. That source of battery power is effective to keep the clock running during periods of power outage and when the apparatus is being moved from one place to another or when, for any other reason, power is disconnected from the line. In preferred form, that battery is capable of running the clock for at least two years and has a shelf life approaching the expected useful life of the refrigerator.
The function of the clock is to make power available for operating the compressor, motor, and any other element of the system whose operation is to be prevented at selected times. In the embodiment shown, only the compressor motor must be prevented as a function of time. To perform its function, the clock rotates cams. The cams actuate switches which control application of power to relay coils 72 and 74. The cam set 64 in this embodiment is arranged to apply power to relay coil 72 at all times except during time interval beginning at time X and ending at time Y. Power is applied to relay coil 74 at all times except during inervals beginning at time W and ending at time X.
In practice, the power controller might be a micro-processor as illustrated in FIG. 3, but micro-processors do not lend themselves to diagrammatic representation in readily understandable form. For the sake of clarity, and to meet the obligation to describe the best embodiment and form, the functional operation of the micro-processor has been depicted in FIG. 2 using symbols taken from the electro-magnetic controller art. Given the diagram of FIG. 2, it is well within the skill of workers in the computer arts to reproduce the functional equivalent in a micro-processor using the instruction sets published by the manufacturers of the selected micro-processor devices.
In FIG. 2, a relay coil 72 is included in the output line X-Y. The relay coil 74 is included in the output line W-X. Coil 74 operates normally open relay contact 78. Coil 72 operates normally open relay contact 80. Contact 80 is connected in a line that extends from line P-1 to line P-2 and which includes the compressor motor 16, a relay coil 76, and a normally open switch 82 which is operated at high limit temperature by the core temperature sensor 40. Switch 78 is connected in a line that extends between power lines P-1 and P-2 and which includes the compressor motor 16 and a normally closed switch 86 which is operated at the low limit temperature by temperature sensor 40. Finally, the compressor circuit includes a manual over-ride switch 110 which is connected in parallel with the switch 78.
The high limit section of the temperature sensor 40 also operates switch 111 which is connected in a line that extends from power line P-1 to power line P-2 and includes the blower or fan 30 and the door switch 46. The fan or blower 30 and the door switch 46 are also connected in a second line that extends from power line P-1 and P02. That second line includes switch contacts 93 which are controlled by relay coil 92, and it includes the switch 44 which, as previously described, is operated by an ambient temperature sensor 47. A third line extends from power line P-1 to power line P-2 and includes a switch 95 operated by moisture sensor 97 and case (enclosure) heater 38. The relay 92 is in series with a fourth line that extends from power line P-1 to power line P-2. That line includes, in series, a switch 94 which is under the control of a frost sensor 96 and the evaporator heater 36. The frost sensor includes a timer and is powered from lines P-1 and P-2. It closes switch 94 when frost is sensed and keeps it closed for a fixed time.
Summarizing, the contro-ler controls five separate electrical control circuits. One of them includes the compressor motor 16. That motor can be energized through the combination of time control switch 80 and core temperature sensor switch 82 and it can be energized through a time controlled switch 78. A second circuit controls operation of the fan or blower 30. It can be energized through either of two sub-circuits both of which include the make-break door switch 46. One of those circuits includes ambient temperature switch 44 and a switch 90 by which fan operation is coordinated with heater operation. The other energizing circuit includes a switch 111 by which operation of the fan is coordinated with the core temperature sensor 40. The third circuit includes the moisture sensor and case heater. The fourth circuit includes the frost sensor and evaporator heater, and the fifth controls the on time of the evaporator heater.
The moisture sensor continuously senses the presence of moisture so that the case heater is energized only until the moisture is removed and is not energized if moisture is not present. The sensor is set to a predetermined level so that it will not energize the case heater until a certain level of moisture is present. It is desired to operate the evaporator heater only when the frost accumulation exceeds a prescribed amount so that frost sensor 96 is arranged to determine whether that amount of frost exists and to close switch 94 when it does.
The circuit is arranged so that the blower will not operate while the heater is operating, and that is accomplished by an interlock between the two circuits. More specifically, when the heater is energized, the relay coil 92 will be energized, it opens switch 93 so that the ambient temperature switch 44 is ineffective to control fan operation.
Further, the circuit is arranged so that the evaporator heater will not operate when the compressor motor is energized, which is accomplished by an interlock between the two circuits. When the compressor is energized, the relay coil 76 is energized, opening switch 112 so that the frost sensor switch 94 is ineffective to control evaporator heater operation.
The clock and cam set combination make it possible to prevent operation of the compressor motor during periods that represent high energy cost peak load periods of the public utility which supplies energy to the refrigeration system. That is done by using the clock to open switches 78 and 80. The time when the compressor is prevented from operating by the opening of those switches is conveniently identified as the "peak load period," and is the period from X to Y.
It is a feature of this embodiment to provide assurance that the cold stored in the evaporator will be at its maximum immediately preceding a high cost peak load period when the compressor will normally be restricted from use. The relay 74 is arranged so that within the time period shown as W-X in FIG. 2 (typically one-half hour) immediately prior to the beginning of a peak load period it will close switch 78 and permit energization of the compressor motor through switch 86. The core temperature sensor 40 is arranged so that it will close switch 86 if the core temperature is higher (warmer) than minus 15 degrees.
It is a further feature of this embodiment that the cold storage level of the evaporator be maintained separately from the requirement for cooling the air within the refrigerator compartment and that the storage level be maintained at a temperature range consistent with the most efficient operation intervals of the compressor and within prescribed limits during hours other than the peak load period. The core temperature sensor 40 is arranged so that at the high limit (warmer) core temperatures above zero degrees Fahrenheit it will close switch 82 and open when the core temperature reaches the lower (colder) limit of minus 15 degrees.
It is a further feature that the structural material of the evaporator provide for efficient low cost manufacture while at the same time providing for maximum retention of cold stored in the evaporator core material. In a preferred embodiment the structural evaporator material is plastic of a sanitary formulation readily formed by continuous extrusion, assuring manufacture at low cost. The plastic formulation selected has the further characteristic of high thermal conductivity at low temperatures. The family of polystyrenes are among the preferred formulations.
In its arrangement of the evaporator in relation to its shroud and the internal vanes of the shroud, as shown in FIG. 1, the preferred embodiment provides for restriction of air flow when the fan is off. This arrangement also restricts convection and assures the retention of cold through capturing and minimizing air flow when the door to the refrigerator compartment is opened.
The greater heat transfer efficiency of the refrigerant circuit (compressor to condenser to evaporator) is captured and stored, thereby enabling the compressor to be restricted from operation during high energy cost periods, resulting in reduced cost of operation for refrigeration. A further advantage of the storage feature is that the compressor runs for a longer time per start, resulting in a total reduction in energy required for refrigeration due to the initial high energy use required to start electric motors.
The less efficient heat transfer from the evaporator to the load through use of the air circuit is the subject of separate control. Air, having low conductivity and poor thermal transfer, requires that its efficient use in refrigeration provide for the greatest cold saturation of the air as possible. Cold saturation of the air medium through the turbulation of the air is achieved by means of vanes provided in the shroud and by an extended path of exposure provided by the maze created by the juxtapositioning of the vanes in the shroud.
To maintain an efficient operation, frost must be removed from the cold storage unit. To perform that task efficiently requires the input of heat, and that is done by installing a full contact electric heater on the several working surfaces of the cold storage unit. The heater is arranged to melt frost rapidly while introducing a minimum amount of heat into the ambient air and the cold storage unit. This is accomplished with a limited use of energy as the frost accumulates directly on the heater surface, permitting direct melting through contact application of heat. A preferred method is to sense the presence of frost and turn the heater on only in those periods when the frost exceeds some predetermined amount and for a limited time for each on period. Ordinarily, it is preferred that the heat exchange between the air and the cold storage unit be suspended at times when the heater is on. The logic scheme depicted in FIG. 2 prevents the fan from operating when the heater is energized. To aid the understanding of the timing of the several events that make up system operation, reference is made to FIGS. 4, 5, and 6. FIG. 4 is a graph showing the time when it is permissible to use energy to operate the compressor motor in a representative situation. The graph assumes that the public utility which supplies energy for the refrigerator experiences its peak load in the period between time X and time Y, and that occurs on regular working days but does not occur on holidays or weekends. Accordingly, a combination of the clock 60 and programming element 64 is arranged so that it is possible to energize the compressor motor at any time on a holiday, at any time except during the high energy cost period during a working day, and at any time during a weekend day. FIG. 5 assumes the use of a core temperature sensor with a high and low limit so that it is possible to measure a high core temperature, such, for example, as zero degrees; and a low temperature, such, for example, as minus 15 degrees. It also assumes that the timer is capable of energizing line W-X in the period from time W to time X. FIG. 5 shows that the compressor can be turned on in the time preceding time W when the core temperature is high. In the anticipatory interval, which is defined as the time between time W and time X, the compressor motor is energized if the core temperature is above the lower limit. Finally, no use of the compressor motor is permissible in the interval from time X to time Y. FIG. 6 shows that fan operation is permissible if the ambient temperature is high. FIG. 7 shows that the fan may be operated only when the heater is off.
A wide variety of mechanical arrangements for the evaporator and the cold storage unit is possible. Nonetheless, there are some preferred forms, and the best form thus far devised is depicted in FIGS. 8 and 9. FIG. 8 is an enlarged cross-sectional view of the shroud structure 32 and the combined evaporator and cold storage unit 14 that is depicted in FIG. 1. In a representative home refrigerator installation the shroud might measure 12 inches wide, four inches high and about 28 inches long. The shroud comprises an elongated tube, rectangular in cross-section and formed of metal or plastic. The upper and lower surfaces of the tube are fitted with a series of vanes that extend from the interior wall inwardly toward the unit 14. They are placed only in that portion of the length of the rectangular tube over which the unit 14 extends. Again, several of them have been marked with reference numeral 34 for identification. A fragment of that shroud is shown in FIG. 9. It comprises a side wall 150 and a lower wall 151. The vanes 34 are arranged in rows that extend transversely across the width of the shroud. The vanes in this embodiment are formed by cutting away portions of a series of barrier walls each of which extends continuously across the shroud. Openings in the barriers are spaced apart a distance of approximately equal to their width. Alternate rows along the length of the shroud are arranged so that their openings are disposed at a position opposite the closed area of the vanes in the row ahead and the row behind. The effect is to create a longer path for air flow through the shroud and to render air flow very turbulent whereby the degree in which that air makes contact with the surface of the cold storage unit 14 is increased. As a consequence, the absorption of heat from the air to storage unit is accomplished more efficiently. In the absence of air being forced through the shroud, very little movement of air occurs within the shroud, and heat transfer is minimized and retained cold storage maximized. The unit 14 comprises a central elongated section 152, an end connector section 154 at each end, and a covering plate 156 at each end. The central section is arranged as best depicted in FIG. 9. This unit is formed of plastic or metal, and it is arranged so that a number of through passages for the flow of refrigerant is formed. The space around those passages is filled with a cold storage medium. That space and the cold storage medium are called the "core." The material of the medium has been omitted from the drawing for the sake of clarity. The end members 154 are attached to the respectively associated ends of the member 152, and they serve to complete a connection from one channel to another so that all of the channels of the member 152 are connected in the series. Thus, for example, the passageways 160 and 162 of member 152 are interconnected when the member 154 of FIG. 9 is placed into engagement with end of member 152. The connection from conduit 160 to conduit 162 is completed in element 164. That element has an entrance opening 166 which mates with conduit 160, and it has an exit opening 168 which mates with conduit 162. Those two openings are interconnected with the element 164. When the end plate 156 is applied over the end of member 154, that interconnecting channel is sealed. In like fashion, the end members 154 and the end plates 156 operate to complete the series connection of the several conduits.
In this application, the members 152, 154 and 156 are formed of a plastic material possessing the property of improved conductivity at lower temperatures. The efficiency with which heat is removed from the core, or, conversely, the efficiency with which cold is stored in the core, can be improved by forming the several conductors within member 152 of metal or other material that is a good conductor of heat. However, the efficiency of the cold storage process is sufficiently high to make it unnecessary to increase cost or to complicate construction of the unit by use of multiple materials.
Returning to the clock, for some applications it is preferred to use a digital clock including an oscillator, counters, comparitors and a ROM in which are stored the times and dates for comparison with the count in the counters. The times and dates referred to define the times and dates when the compressor may be used and is not to be used. That is conveniently accomplished, as in business computer clocks, by using a Julian Calendar clock and defining days by Julian day number and hours and minutes as conventional hours and minutes. There are many micro-processors capable of performing not only the clock functions but all of the control functions. The Intel 8080A family of microcomputer devices is preferred now for several reasons. It is fully documented, there are several sources, it is familiar to many computer technicians and engineers, and it employs separate timer and clock devices. The latter is advantageous because they can be powered separately from a battery during shipping and moving and during utility power outages. The clock functions can be continued without need to supply power to the entire of the micro-processor whereby less battery power is required.
The frost sensor function may be performed by a comparison of the actual operating rate of heat transfer achieved over a stated time interval of evaporator fan operation as measured by the ambient temperature sensor and counted by the clock, against a standard of performance representing heat transfer effect during a similar time period on the ambient sensor when the evaporator is defrosted. An unfavorable comparison of actual performance to standard will in that practice initiate a command to energize the defrost heater.
To form the micro-processor, an 8080A central computing unit, an 8224 System Clock Generator and Drive and an 8228 System Controller are combined with an 8253 Programmable Timer and an 8255 Parallel I/O and an 8259 Priority Interrupt Control. These are connected as described in the Intel Corporation documentation to drive switches either electromechanically as shown in FIG. 2 or equivalent solid state switches in the arrangement depicted in FIG. 3.
Whether it be the Intel 8080A family or another, it is a feature of the invention to put the time-on/time-off data in a memory device that is attachable to the unit. Similarly, the minimum-run-time-per-start-feature will be incorporated in the memory device. The programmable memory device feature, whether in a ROM or in an electromechanical cam set, makes it possible to manufacture the unit complete except for loading of the memory device without regard to its ultimate destination. The data that is loaded into memory is to be defined by the utility which serves the area in which the refrigerator is installed. The memory unit can be loaded by the retail seller or by the utility company or the utility company may elect to furnish pre-loaded memory units. That feature makes the invention very practical, and it makes it possible for the advantages offered by the invention to be made available to users and to energy suppliers without any major change in selling or business procedures.
In FIG. 2, it is the cam unit 64 that is the memory device that contains the compressor off-time program specified by the utility company. Like the read-only memory unit or ROM described above, it may be different for each utility company service area. In this embodiment, like the ROM, it is replaceable. Cams 200 and 201 are seven-day cams, one to interrupt power in the X-Y period on week days and the other 201 to interrupt power in the W-X period on week days. Cam 203 is a daylight savings time cam driven through a gear box 204 and cam 205 is a holiday gear driven through a gear box 206 which includes both a speed reducer and a leap year Geneva gear. Gear 203 controls the flow of energy in series with gears 201 and 200 to relay coils 74 and 72, respectively. Gear 205 supplies energy directly to the relay coils on holidays.
Although we have shown and described certain specific embodiments of our invention, we are fully aware that many modifications thereof are possible. Our invention, therefore, is not to be restricted except insofar as is necessitated by the prior art. | 4y
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STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT.
This invention was made with Government support under Contract Number DAAK 20-84-C-0147 awarded by the Department of Defense (DOD). The Government has certain rights in this invention.
CROSS REFERENCE TO RELATED APPLICATION
This is a divisional of co-pending application Ser. No. 07/355,711 filed on May 22, 1989, now U.S. Pat. No. 4,929,405, which is a continuation-in-part of application Ser. No. 07/339,903 filed on Apr. 17, 1989, now issued as U.S. Pat. No. 4,880,699 on Nov. 14, 1989, which is a continuation of application Ser. No. 07/267,712. Filed on Nov. 4, 1988, now abandoned, which is a continuation of application Ser. No. 07/149,824 which was filed on Jan. 29, 1988, now abandoned, which is a divisional of application Ser. No. 06/917,731 filed on Oct. 10, 1986, now issued as U.S. Pat. No. 4,746,474.
BACKGROUND OF INVENTION
1. Field of Invention
This invention relates to polymer films. More particularly, this invention relates to ultrathin, polyimide polymer films and their production.
2. Prior Art
In U.S. Pat. No. 3,673,145, a process for preparing polyimide solutions that can be cast as films is disclosed. However, the disclosed films have thicknesses between 15 microns (i.e. 150,000 angstroms) and 80 microns (i.e. 800,000 angstroms) and cannot, therefore, be classified as ultrathin polyimide films.
In U.S. Pat. No. 2,867,609 void-free films allegedly prepared from polypyromellitimides are disclosed. However, no film thicknesses are disclosed.
In U.S. Pat. No. 2,710,853, polypyromellitimide films having thicknesses of three to seven mils are disclosed. However, the films are not ultrathin.
In U.S. Pat. No. 3,179,614, polyamide-acid films having thicknesses of 0.1 to 1.0 mils are converted to polyimide films by either heating the films or by treating them with acetic anhydride and pyridine. Such films, however, are not ultrathin.
Similarly, in U.S. Pat. Nos. 3,179,633 and 3,179,634, polyamide-acid films having thicknesses between 0.1 and 7 mils are thermally or chemically converted to polyimide films.
In U.S. Pat. No. 2,760,233, a process is disclosed for preparing curved polymer sheets from polyimide polymers. However, polyimide films are not disclosed nor are specific solvent mixtures and ratios suitable for casting ultrathin, pinhole-free, polyimide films disclosed.
U.S. Pat. No. 3,551,244 discloses a process for preparing on a water surface films having thicknesses between 0.05 and 5.0 microns (i.e. between 500 and 50,000 angstroms). The patent discloses that certain halogenated solvents, such as chlorobenzene, are suitable casting solvents and states that polyamide films can be prepared. However, polyimide polymers are not disclosed as being suitable and no specific solvent mixtures and ratios suitable for casting pinhole-free polyimide films having thicknesses less than 400 angstroms are disclosed.
In U.S. Pat. No. 3,933,561, a process for preparing polymeric films on water is disclosed. The film thicknesses are usually less than about 2.5 microns (i.e. 25,000 angstroms) and thicknesses of less than 0.1 micron (i.e. 1000 angstroms) are allegedly achieved. While polyamides are allegedly suitable for the patent's process, polyimide films are not disclosed nor are specific solvent mixtures and ratios suitable for casting ultrathin polyimide films.
U.S. Pat. No. 3,767,737 discloses a method for producing nonporous polymer membranes having thicknesses between 0.005 and 0.05 mils on a support liquid. Any polymer capable of being cast as a film from solvents is asserted to be suitable for use in the patent's process. However, polyimides are not specifically listed as suitable polymers and specific mixtures of solvents and appropriate solvent ratios for preparing pinhole-free polyimide films having thicknesses of 400 angstroms or less are not disclosed.
U.S. Pat. Nos. 4,155,793, 4,279,855 and 4,374,891 disclose processes for preparing substantially void-free, ultrathin, permeable, polymeric membranes having a thickness of 500 angstroms or less. Organic and inorganic polymers are allegedly suitable for use in the patent's process. However, only films prepared from organopolysiloxane-polycarbonate interpolymers mixed with polyphenylene oxide are disclosed in the examples. Polyimide films are not disclosed nor are suitable solvent mixtures and ratios for casting polyimide films having thicknesses of 400 angstroms or less.
Other patents, such as U.S. Pat. Nos. 2,631,334, 2,689,187, and 4,393,113, also disclose ultrathin, polymeric films. However, polyimide films are not disclosed.
U.S. Pat. Nos. 3,356,648 and 3,959,350 disclose fluorinated polyimide films. However, no film thicknesses are disclosed, and a process for preparing ultrathin, pinhole-free, polyimide films is not disclosed.
U.S. Pat. No. 4,592,925 discloses fluorinated polyimide films having thicknesses of about 0.1 mil to about 0.5 mil (i.e., about 25,400 to about 127,000 angstroms). U.S. Pat. No. 4,645,824 discloses fluorinated polyimide films having thicknesses of about 0.1 mil to about 2.0 mils (i.e., about 25,400 to about 508,000 angstroms). Thus, these patents do not disclose ultrathin polyimide films.
Commonly-asigned U.S. patent application Ser. No. 07/217,928 discloses films having a thickness in the range of about 2 to about 3 mils prepared from copolyimides derived from 2,2-bis(aminophenyl) hexafluoropropane. Commonly-assigned U.S. patent application Ser. No. 07/217,929 now abandoned discloses that films having thicknesses of several mils can be prepared by high molecular weight polyimides containing hexafluoropropylidene linkages. Neither patent however, discloses the preparation of ultrathin films nor a means for preparing such films.
In the prior art, the preparation of ultrathin, pinhole-free, polyimide, free-standing films having thicknesses of less than 400 angstroms generally has not been disclosed. Usually, prior art polymer films having thicknesses of less than 400 angstroms contain voids and other macroscopic defects.
Therefore, it is an object of this invention to prepare ultrathin, polyimide polymer films.
It is a further object of this invention to prepare pinhole-free, polyimide polymeric films.
It is also an object of this invention to prepare free-standing, polyimide films having thicknesses of 400 angstroms or less.
These and other objects are obtained by the products and process of the present invention.
SUMMARY OF INVENTION
The instant invention provides a process for preparing macroscopically pinhole-free, ultrathin, free-standing polyimide films having thicknesses of about 400 angstroms or less. The films are prepared by dissolving a polyimide polymer in a suitable solvent or mixture of solvents, such as a mixture of 1,2,3-trichloropropane and ortho-dichlorobenzene, to form a polymeric solution, casting the solution on water to form a free-standing film, and removing the film from the water. The ultrathin films of the present invention can be used in separatory applications and as drug release membranes for the controlled release of drugs.
DETAILED DESCRIPTION OF INVENTION
The preparation of polyimides is well known in the prior art. Polyimides are generally prepared in a two-step process in which a dianhydride and a diamine are first reacted to prepare a polyamic acid which is subsequently converted to a polyimide in a second step.
A wide variety of dianhydrides and diamines can be reacted to prepare polyimides that are suitable for use in the present invention. Dianhydrides and diamines that can be reacted to yield suitable polyimides as well as processes for preparing such polyimides are disclosed in "Polyimides," by C. E. Sroog, J. Polymer Science: Macromolecular Reviews, volume 11, 161-208 (1976), and U.S. Pat. Nos. 2,710,853, 3,179,631, 3,179,634, 3,356,648, 3,959,350, 4,592,925 and 4,645,824 which are incorporated herein by reference. The preferred dianhydrides are 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride and pyromellitic dianhydride. The preferred diamines are bis-(4-aminophenyl) ether, 5(6)-amino-1-(4'-aminophenyl)-1,3,3-tri-methylindane (referred to as DAPI), 2,2-bis(3-aminophenyl) hexafluoropropane (referred to as 3,3'-6F diamine), 2,2-bis(4-aminophenyl)hexafluoropropane (referred to as 4,4'-6F diamine), 2-(3-aminophenyl)-2-(4-aminophenyl) hexafluoropropane, 2,2-bis(3-aminophenyl)-1,1,1-trifluoro-2-phenyl-ethane, 2,2-bis(4-aminophenyl)-1,1,1-trifluoro-2-phenyl-ethane and 2-(3-aminophenyl)-2-(4-aminophenyl)-1,1,1-trifluoro-2-phenyl-ethane.
A variety of solvents can be used for the reaction of the dianhydride with the diamine. Suitable solvents are disclosed in U.S. Pat. No. 3,179,634. Preferably, the solvent is dimethyl formamide, dimethyl sulfoxide, N-methyl pyrrolidone or dimethylacetamide, and most preferably is dimethylacetamide.
After a polyamic acid is prepared by the reaction of a diamine and a dianhydride, the polyamic acid is converted to a polyimide using thermal or chemical conversion processes. Preferably, the polyamic acid is chemically converted employing acetic anhydride in the presence of pyridine. If a fluorinated polyamic acid is involved, it is preferred to employ acetic acid in the presence of beta picoline. The resulting polyimide can be precipitated by water and then filtered and dried.
Some of the preferred polyimides have repeating units of the formula: ##STR1## wherein R is a tetravalent organic radical and R' is a divalent organic radical selected from the group consisting of aromatic, aliphatic, cycloaliphatic, heterocyclic, combinations of aromatic and aliphatic, and substituted groups thereof (e.g. with halogen and methyl substituents and/or other substituents known to those skilled in the art). In one preferred embodiment, R or R' or both contain fluorine substituents. Preferably R is a tetravalent aromatic radical containing at least one ring of six carbon atoms, said ring being characterized by benzenoid unsaturation and the four carbonyl groups being attached directly to separate carbon atoms in a ring of the R radical and each pair of carbonyl groups being attached to adjacent carbon atoms in a ring of the R radical, and preferably R' is a divalent benzenoid radical, or substituted groups thereof, selected from the group consisting of: ##STR2## wherein R" is selected from the group consisting of a substituted or unsubstituted alkyl or alkylene chain having one to three carbon atoms, ##STR3## wherein R"' and R"" are selected from the group consisting of substituted or unsubstituted alkyl and aryl.
R may also preferably be a tetravalent aromatic radical, or substituted groups thereof, selected from the group consisting of ##STR4## wherein R" is defined as above.
Most preferably, R" above is selected from the group consisting of ##STR5##
In a most preferred polyimide polymer, R is ##STR6## and R' is ##STR7## and it can be represented by the general formula: ##STR8## It is prepared by the reaction of DAPI with 3,3',4,4'-benzophenone tetracarboxylic dianhydride to produce a polyamic acid. The polyamic acid can be chemically imidized using acetic anhydride and pyridine according to the teachings of U.S. Pat. No. 3,179,634. The preferred polyimide polymer is sold under the tradename Araldite XU 218 and is available from the Ciba-Geigy Corporation.
In another most preferred polyimide, R is ##STR9## and R' is ##STR10## and preferably R' is ##STR11## and most preferably R' is ##STR12##
The polyimide wherein R' is ##STR13## can be represented by the general formula ##STR14## and may be prepared by reacting 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride and a diamine selected from the group consisting of 2,2-bis(3-aminophenyl)-1,1,1-trifluoro-2-phenyl-ethane, 2,2-bis(4-aminophenyl)-1,1,1-trifluoro-2-phenyl-ethane, and 2-(3-aminophenyl)-2-(4-aminophenyl)-1,1,1-trifluoro-2-phenyl-ethane in accordance with the teachings in U.S. Pat. Nos. 3,356,648 and 4,645,824.
The preferred fluorinated polyimide above wherein R' is ##STR15## can be represented by the general formula ##STR16## and may be prepared by reacting 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (referred to as 6F-DA) and a diamine selected from the group consisting of 2,2-bis(3-aminophenyl) hexafluoropropane, 2,2-bis(4-aminophenyl) hexafluoropropane and 2-(3-aminophenyl)-2-(4-aminophenyl) hexafluoropropane. Preferably, equimolar amounts are reacted and a low-temperature, substantially isothermal polymerization process followed by cyclization is employed. Most preferably, substantially analytically pure reactants are utilized. The preparation of this preferred polyimide is described in U.S. Pat. Nos. 3,356,648 and 4,645,824 and in commonly assigned U.S. patent application Ser. No. 07/217,929, which are incorporated herein by reference. The 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6F-DA) is available from Hoechst-Celanese Corporation in Somerville, NJ.
It is also possible to prepare the films of the present invention from fluorinated polyimides prepared by reacting 2,2-bis(3-aminophenyl) hexafluoropropane or 2,2-bis(4-aminophenyl) hexafluoropropane with pyromellitic dianhydride and one or more additional aromatic dianhydrides, preferably a dianhydride having a diaryl nucleus. Preferred aromatic dianhydrides include bis(3,4-dicarboxyphenyl) ether dianhydride (ODPA), 3,3',4,4'-benzophenone tetracarboxylic dianhydride (BTDA), 3,3',4,4'-diphenyl tetracarboxylic acid dianhydride (BPDA) and 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6F-DA), with 6F-DA being the most preferred dianhydride. Such polyimides are soluble in common organic solvents such as methyl ethyl ketone or N-methyl pyrrolidone. The preparation of suitable mixed dianhydride fluorinated polyimides is disclosed in U.S. patent application Ser. No. 07/217,928, which is incorporated herein by reference. Suitable conditions for reacting the diamine and the dianhydrides are disclosed in U.S. Pat. Nos. 3,356,648 and 3,959,350, which were previously incorporated by reference.
In a preferred process for preparing such fluorinated polyimides, the diamine and the mixed dianhydrides are reacted in a suitable solvent such as N-methyl pyrrolidone, gamma-butyrolactone (BLO), or a mixture of BLO and another solvent such as diglyme. The resulting product is a polyamide-acid which is then converted to the desired polyimide by one of several methods: by heating the polyamide-acid solution until imidization is substantially complete, or by combining the polyamide-acid solution and a dehydrating agent, with or without a catalyst, and optionally heating the resulting mixture until imidization is substantially complete.
The mixed dianhydrides and the diamine are reacted in approximately equimolar proportions. The relative proportion of the dianhydrides with respect to one another ranges from about 35 to about 75 mole percent pyromellitic dianhydride and correspondingly from about 25 to about 65 mole percent of the co-dianhydride (e.g. ODPA, BTDA, BPDA or 6F-DA). The preferred ratio of the dianhydrides is about 50 mole percent of each of the co-dianhydrides.
The 3,3'-6F diamine and 4,4'-6F diamine reactants may also be used in admixture with other non-6F-aromatic diamines in preparing suitable copolyimides. The limit of addition of the additional non-6F-diamine is determined by solubility factors in that the resulting copolyimide must contain sufficient fluoro substituent groups to remain soluble in the organic solvent. Suitable diamines are materials responding to the general formula H 2 N--R--NH 2 wherein R is a divalent organic radical. Preferably R comprises an aromatic moiety. Most preferably, R has a diaryl nucleus, e.g. a phenylene or naphthalene group.
Generally, the preferred polyimide polymers have molecular weights, M w , greater than about 25,000. In addition, the most preferred fluorinated polyimide polymers have molecular weights, M w , of at least about 75,000.
Although 1,2,3-trichloropropane alone can be employed to cast ultrathin polyimide films, it is preferred to employ a mixture of 1,2,3-trichloropropane and ortho-dichlorobenzene. The presence of ortho-dichlorobenzene in the solution used for casting the film tends to make the film more uniform in thickness. Suitable solvent ratios are about a 1:1 to about a 10:1 by volume ratio of 1,2,3-trichloropropane: ortho-dichlorobenzene and preferably about a 20:7 ratio. The solvent ratios described above should not be altered substantially because if too much ortho-dichlorobenzene is employed, the film may be too thin and fragile to lift from the casting surface.
When fluorinated polyimides are employed, propyl acetate or butyl acetate may also be utilized as the casting solvent to prepare ultrathin, pinhole-free films. However 1,2,3-trichloropropane and butyl acetate are preferred, with 1,2,3-trichloropropane (and mixtures of 1,2,3-trichloropropane and ortho-dichlorobenzene) being most preferred.
The polyimide polymer is first dissolved in a suitable solvent or solvent mixture to prepare a casting solution by stirring the polymers and solvents at a temperature less than 100° C. (e.g. 60° C.) for several hours (e.g. three to seven hours). The casting solution will contain about two to about twelve percent by weight of the polymer, preferably about four to about ten percent and most preferably about six to about eight percent based upon the total weight of the casting solution. Generally, the greater the amount of polymer in the casting solution; the thicker the films will be that are prepared. Conversely, the lower the amount of polymer, the thinner the films will be. However, if the percent by weight is too low, such as below one percent by weight, the film will be too fragile to lift from the casting surface and will contain defects, such as holes. The polymer solution can be employed immediately after preparation or stored in appropriate containers, such as teflon bottles, at room temperature.
Although the films are generally prepared from a single polyimide, the polyimide films may be cast from a casting solution containing two or more polyimide polymers which are compatible in film form and which can be dissolved in the casting solution. For example, a casting solution wherein the solvent is butyl acetate and wherein the casting solution contains a polyimide having the general formula ##STR17## and a polyimide having the general formula ##STR18## yields excellent, ultrathin, pinhole-free polyimide films. The ratio of the polyimides is not critical when such blended films are prepared.
The polyimide films may also be cast from a mixed polymer solution containing a polyimide polymer and a minor amount of other non-polyimide polymers which are compatible in film form with the polyimide polymer and which can be dissolved in the casting solution. When other polymers are added, the amount of polyimide employed should be about 80 percent or more by weight based upon the total weight of polymers dissolved in the polymeric solution.
Before the polymeric solution is cast into films, it is preferred to filter the solution using membranes. Filtration of the polymer solution before casting substantially reduces imperfections in the cast films. The solution can be passed through a Millipore microfiltration membrane having pores with a diameter of about 0.45 micron and available from the Millipore Corporation. In order to pass the solution through the membrane, it is usually necessary to apply pressure. For example, a Millipore stainless 47 mm pressure holder operated at a pressure up to 100 psi argon can be used. The amount of pressure applied will depend upon the viscosity of the solution and the pore size of the membrane.
After filtration, the solution is cast on water at or near room temperature. As used herein, the term "water" includes aqueous solutions containing minor amounts (e.g. one percent or less by weight based upon the total weight of the solution) of organic solvents (e.g. lower weight alcohols) the presence of which does not adversely affect the properties of the film cast on the solution. The addition of such organic solvents may facilitate the removal of the film from the water's surface. The water is contained in any suitable walled container. For example, an appropriate container is an aluminum container having the dimensions 12"×12"×3". Preferably, the walls of the container are sloped outwardly at about a 20 degree incline to reduce reflected surface waves which can damage the film. Such waves are produced when the polymeric solution is placed on the water's surface or by air currents and external vibrations. Most preferably, the inside walls of the container are teflon coated so that films are less likely to stick to the sides of the container.
The polymeric solution is cast by depositing a drop of the polymer solution upon the water's surface. The solution usually spreads over the surface of the water in three seconds or less. The solution is allowed to stand until a sufficient amount of the solvent has evaporated to form a free-standing film. As used herein the term "free-standing film" refers to a film which has a physically stable shape and is dimensionally stable on its casting surface and can be removed from the casting surface without having to be supported over most (e.g. 30 percent or more) of its surface area. The time of evaporation generally is between 20 and 30 seconds and rarely more than about 60 seconds.
After the solvent has evaporated, the film is lifted from the liquid surface using any suitable means, such as a 2"×3", thin, aluminum plate having a 30 millimeter inner diameter hole in it and a handle on one end of the plate. When the aluminum plate touches the surface of the film, the film adheres to the aluminum plate and may be readily removed from the surface of the water.
The films of the instant invention can be rendered insoluble in their casting solvents and made more durable and chemically resistant by any suitable treatment, such as by radiation, photochemical, chemical, or thermal treatment. Preferably a thermal treatment is employed. For example, the films can be heated at temperatures in the range of about 250° C. to about 350° C., preferably about 290° C., for several hours.
When using a thermal treatment, it is preferred to heat and cool the films very gradually in order to avoid film breakage. For example, the films can be heated from room temperature to the desired temperature at a rate of 2° C. per minute, held at the desired temperature for about two hours, and then gradually allowed to cool to room temperature. Any oven that permits such increments in temperature can be employed.
The films of the instant invention are generally round, ultrathin, pinhole-free, uniform films having a diameter of about four to about six inches and a thickness of about 400 angstroms or less, preferably less than about 300 angstroms and most preferably about 150 to about 300 angstroms. As used herein, the term "ultrathin film" refers to a film having a thickness of 400 angstroms or less, and the term "pinhole-free film" refers to a film having no macroscopic holes.
The films of this invention can be used in end uses where a controlled release of drugs is needed and can be placed on supports and used as gas separation membranes.
The invention is illustrated by the following examples in which all percentages are by weight unless otherwise specified.
EXAMPLE 1
A polymer solution containing 7.4 percent by weight polyimide in a mixture of 20:7 by volume 1,2,3-trichloropropane:ortho-dichlorobenzene was prepared by dissolving the polymer in the solvent mixture. The polyimide was Araldite XU 218, had a density of 1.20 g/cm 3 , was obtained from the Ciba-Geigy Corporation, Inc., and had repeating units of the formula: ##STR19## The solution was prepared by magnetically stirring the solvents and the polymer at 60° C. for about five hours.
After the polymer was dissolved in the solvent it was passed through a Durapore polyvinylidene fluoride membrane having pores with a diameter of 0.45 micron obtained from the Millipore Corporation. A Millipore stainless 47 millimeter pressure holder operated at a pressure sufficient to force the solution through the membrane was employed.
After filtration, a drop of the polymer solution was deposited on water contained in a square aluminum container measuring 12"×12"×3" and having teflon coated walls which were sloped away from the center at a 20 degree incline. The drop spread rapidly over the surface of the water to form a film having a diameter of about five inches. After 20 seconds, the film was lifted from the surface of the water using a 2" by 3" aluminum plate with a 30 mm diameter hole in the middle and a handle at one end. The film was uniform, had a thickness of about 230 angstroms and contained no macroscopic voids.
The film was thermally treated by placing the film in a Fisher Isotemp Programmable Ashing Furnace, Model 495, at room temperature and then increasing the temperature at a rate of 2° C. per minute to 290° C. The oven was held at 290° C. for two hours and then the temperature was reduced gradually back to room temperature to cool the film. The resulting film was not soluble in 1,2,3-trichloropropane.
EXAMPLE 2
Example 1 was repeated except that the film was not thermally treated. When a drop of trichloropropane was placed on the film, the film dissolved instantly.
EXAMPLE 3
Example 1 was repeated except that a ten percent by weight solution of the polyimide in 1,2,3-trichloropropane was prepared and the film was not thermally treated. The resulting film contained no macroscopic holes and had a thickness of about 350 angstroms.
EXAMPLE 4
Example 1 was repeated except that an eight percent by weight solution of the polyimide polymer in a 4:1 by volume mixture of 1,2,3-trichloropropane:ortho-dichlorobenzene was prepared. The resulting film had a thickness of about 250 angstroms and contained no macroscopic holes.
EXAMPLE 5
Example 1 was repeated except that a polymer solution containing about 6.0 percent by weight of a fluorinated polyimide in a 3:1 by volume ratio of 1,2,3-trichloropropane:ortho-dichlorobenzene was employed and the film was not thermally treated. The fluorinated polyimide was prepared by reacting 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane dianhydride and 2,2-bis(4-aminophenyl) hexafluoropropane in accordance with the teachings of U.S. patent application No. 07/217,929, which was previously incorporated by reference, and had repeating units of the formula: ##STR20## The polyimide had a density of about 1.47 g/cc and a molecular weight, M w , of about 200,000. The resulting film contained no macroscopic holes and had a thickness of about 230 angstroms.
EXAMPLE 6
Example 5 was repeated except that the fluorinated polyimide was prepared by reacting 2,2-bis(3,4-dicarboxyphenyl) hexafluoropropane and 2,2-bis(3-aminophenyl) hexafluoropropane in accordance with the teachings of U.S. patent application Ser. No. 07/217,929, which was previously incorporated by reference, and had repeating units of formula: ##STR21## The polyimide had a density of about 1.49 g/cc and a molecular weight, M w , of about 174,000. The resulting film contained no macroscopic holes and had a thickness of less than 400 angstroms.
EXAMPLE 7
Example 5 was repeated except that the polymer solution contained about 6.0 percent by weight of the polyimides used in Examples 5 and 6 in butyl acetate. Equal amounts by weight of the two polyimides were present. The resulting film had a thickness of about 250 angstroms and contained no macroscopic holes.
EXAMPLE 8
Example 7 was repeated except that the polyimide used in Example 6 was present at about the 80 percent by weight level and the polyimide used in Example 5 was present at about the 20 percent by weight level based upon the total weight of polyimides in the casting solution. The resulting film had a thickness of less than about 200 angstroms and contained no macroscopic holes.
As can be seen, thermally treating the films can make them insoluble in their casting solvent and chemically more resistant, and 1,2,3-trichloropropane alone or mixtures of 1,2,3-trichloropropane and ortho-dichlorobenzene may be employed to cast ultrathin, pinhole-free films. | 4y
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FIELD OF THE INVENTION
[0001] This invention relates to multilayer laminates. More particularly, the invention relates to reflective metal multilayer laminates which can be bonded to various substrates, including exterior automotive panels, as a protective and/or decorative covering.
BACKGROUND OF THE INVENTION
[0002] Metallized films can be produced by various techniques such as the vacuum metallizing process. The principal of the vacuum metallizing process lies in heating a metal such as aluminum, nickel, chromium or alloys thereof, etc. in high vacuum equipment at temperatures higher than its melting point to cause the metal to vaporize, radiating and condensing the metal on a cooled substrate to be metallized such as onto plastic films, thereby forming thin layers of the metal. The metallized films thus produced find application in decorative materials, the electrical industry, agriculture, packaging systems, etc.
[0003] In the past, highly reflective metal surfaces have been used on many decorative articles. A typical use is in metal bumpers and trim parts for automobiles. Chrome plating is generally used because of its high reflectivity, corrosion resistance, and abrasion resistance.
[0004] The reflective metal trim parts on automobiles are typically made from metal castings which are chrome-plated and commonly attached to the automobile body by metal clips or fasteners. The disadvantages of such trim parts include the additional weight added to the automobile, time-consuming and relatively expensive attachment techniques, and corrosion problems resulting because the trim parts are made from a metal which is different from that of the automotive body and thereby causes corrosion from electroylsis of the disimilar metals. Despite these problems, chrome-plated metal trim parts continue in use today, at least in part because of the relative ease in which differently shaped surface configurations can be plated with highly reflective, abrasion resistant and corrosion-resistant metal such as chromium.
SUMMARY OF THE INVENTION
[0005] Metallized multilayer laminates are described which provide a bright reflective finish on deformable articles, such as impact absorbing bumpers of automobiles and also provide bright reflective surfaces on molded parts or three-dimensional shapes as an alternative to chrome plating. In one embodiment, the multilayer laminates of the present invention comprise:
[0006] (A) a base layer having a first-surface and a second surface, and comprising a metallizable polymer,
[0007] (B) a metal layer having a first-surface and a second surface wherein the first surface of the metal layer is in contact with and adhered to the second surface of the base layer,
[0008] (C) a clear polymer topcoat layer having a first-surface and a second surface wherein the second surface is in contact with and adhered to the first surface of the base layer, and
[0009] (D) an adhesive layer having a first surface and a second surface wherein the first surface of the adhesive layer is in contact with and adhered to the second surface of the metal layer.
[0010] In another embodiment, the metallized multilayer laminate of the present invention has an exterior distinctness of image (DOI) value of at least 80 and comprises:
[0011] (A) a base layer having a first-surface and a second surface, and comprising a metallizable polymer,
[0012] (B) a metal layer having a first-surface and a second surface wherein the first surface of the metal layer is in contact with and adhered to the second surface of the base layer,
[0013] (C) a polymer tie layer having a first surface and a second surface wherein the second surface of the tie layer is in contact with and adhered to the first surface of the base layer,
[0014] (D) a clear polymer topcoat layer having a first surface and a second surface wherein the second surface of the clear topcoat layer is in contact with and adhered to the first surface of the tie coat layer,
[0015] (E) an adhesive layer having a first surface and a second surface wherein the first surface of the adhesive layer is in contact with and adhered to the second surface of the metal layer.
[0016] In yet another embodiment, the metallized multilayer laminates of the present invention comprise:
[0017] (A) a base layer having a first-surface and a second surface, and comprising a metallizable polymer,
[0018] (B) a metal layer having a first-surface and a second surface wherein the first surface of the metal layer is in contact with and adhered to the second surface of the base layer,
[0019] (C) a first adhesive layer having a first surface and a second surface wherein the first surface of the first adhesive layer is in contact with and adhered to the second surface of the metal layer,
[0020] (D) a second pressure sensitive adhesive layer having a first surface and a second surface wherein the second surface of the second pressure sensitive adhesive layer is in contact with and adhered to the first surface of the base layer,
[0021] (E) a clear polymer layer having a first surface and a second surface wherein the second surface of the clear polymer layer is in contact with and adhered to the first surface of the second pressure sensitive adhesive layer,
[0022] (F) a polymer tie coat layer having a first surface and a second surface wherein the second surface of the tie coat layer is in contact with and adhered to the first surface of the clear polymer layer, and
[0023] (G) a clear polymer topcoat layer having a first surface and a second surface wherein the second surface of the clear topcoat layer is in contact with and adhered to the first surface of the tie coat layer.
[0024] These and other embodiments of the invention are more fully described below and can be fully understood by referring to said description and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] [0025]FIG. 1 is a schematic cross-sectional view illustrating one embodiment of the multilayer laminates according to the present invention. Film thicknesses are exaggerated for simplicity.
[0026] FIGS. 2 - 9 are further schematic cross-sectional views illustrating various embodiments of the multilayer laminates of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] Various embodiments of the invention are illustrated in FIGS. 1 - 9 . These figures illustrate the various layers that may comprise the multilayer laminates of the present invention. Referring to FIG. 1, a multilayer laminate 10 according to this embodiment, includes a base layer 11 having a first surface and a second surface, a metal layer 12 having a first surface and a second surface wherein the first surface of the metal layer 12 is in contact with and adhered to the second surface of the base layer, an adhesive layer 13 having a first surface and a second surface wherein the first surface of the adhesive layer 13 is in contact with an adhered to the second surface of the metal layer 12 , and a clear topcoat layer 14 having a first surface and a second surface wherein the second surface of the topcoat layer 14 is in contact with and adhered to the first surface of the base layer 11 . The compositions of the various layers of the construction 10 of FIG. 1, as well as the layers of the constructions of FIGS. 2 - 9 will be discussed in more detail below following this brief discussion of the figures.
[0028] Referring to FIG. 2, a multilayer laminate 20 is illustrated which comprises a base layer 21 having a first surface and a second surface, a metal layer 22 having a first surface and a second surface wherein the first surface of the metal layer 22 is in contact with and adhered to the second surface of the base layer 21 , an adhesive layer 23 having a first surface and a second surface wherein the first surface of the adhesive layer 23 is in contact with and adhered to the second surface of the metal layer 22 , a tie coat layer 25 having a first surface and a second surface wherein the second surface of the tie coat layer 25 is in contact with and adhered to the first surface of the base layer 21 , and a topcoat layer 24 having a first surface and a second surface wherein the second surface of the topcoat layer 24 is in contact with and adhered to the first surface of the tie coat layer 25 .
[0029] [0029]FIG. 3 illustrates another embodiment of the multilayer laminates of the present invention which comprises a base layer 31 having a first surface and a second surface, a metal layer 32 having a first surface and a second surface wherein the first surface of the metal layer 32 is in contact with and adhered to the second surface of the base layer, an adhesive layer 33 having a first surface and a second surface, wherein the first surface of the adhesive layer is in contact with and adhered to the second surface of the metal layer, a barrier layer 36 having a first surface and a second surface wherein the second surface of the barrier layer 36 is in contact with the first surface of the base layer 31 , and a topcoat layer 34 having a first surface and a second surface, wherein the second surface of the topcoat layer 34 is in contact with and adhered to the first surface of the barrier layer 36 .
[0030] [0030]FIG. 4 illustrates another embodiment of the multilayer laminates of the present invention. The multilayer laminate 40 comprises a base layer 41 having a first surface and a second surface, a metal layer 42 having a first surface and a second surface wherein the first surface of the metal layer 42 is in contact with and adhered to the second surface of the base layer 41 , a first adhesive layer 43 having a first surface and a second surface wherein the first surface of the first adhesive layer 43 is in contact with and adhered to the second surface of the metal layer 42 , a second PSA layer 47 having a first surface and a second surface wherein the second surface of the second PSA layer 47 is in contact with and adhered to the first surface of the base layer 41 , and a topcoat layer 44 having a first surface and a second surface wherein the second surface of the topcoat layer 44 is in contact with and adhered to the first surface of the second PSA layer 47 . This embodiment provides a method of improving the adhesion of the topcoat layer 44 to the base layer 41 when desired or necessary.
[0031] The multilayer laminate 50 of the embodiment illustrated in FIG. 5 includes a base layer 51 having a first surface and a second surface, a metal layer 52 having a first surface and a second surface, wherein the first surface of the metal layer 52 is in contact with and adhered to the second surface of the base layer 51 , an adhesive layer 53 having a first surface and a second surface wherein the first surface of the adhesive layer 53 is in contact with and adhered to the second surface of the metal layer 52 , a tie coat layer 55 having a first surface and a second surface wherein the second surface of the tie coat layer 55 is in contact with and adhered to the first surface of the base layer 51 , a barrier layer 56 having a first surface and a second surface wherein the second surface of the barrier layer 56 is in contact with and adhered to the first surface of the tie coat layer 55 , and a topcoat layer 54 having a first surface and a second surface wherein the second surface of the topcoat layer 54 is in contact with and adhered to the first surface of the barrier layer 56 . This embodiment provides a method for improving the adhesion of a barrier layer to the base layer and provides a barrier layer to prevent migration of, for example, plasticizers which may be present in the topcoat layer, particularly when the topcoat layer comprises polyvinyl chloride (PVC).
[0032] [0032]FIG. 6 illustrates another embodiment of the multilayer composites of the present invention wherein one of the layers is an ink layer. In particular, the multilayer laminate 60 illustrated in FIG. 6 includes a base layer 61 having a first surface and a second surface, a metal layer 62 having a first surface and a second surface wherein the first surface of the metal layer 62 is in contact with the second surface of the base layer 61 , an adhesive layer 63 having a first surface and a second surface wherein the first surface of the adhesive layer 63 is in contact with and adhered to the second surface of the metal layer 62 , a tie coat layer 65 having a first surface and a second surface, wherein the second surface of the tie coat layer 65 is in contact with and adhered to the first surface of the base layer 61 , an ink layer 68 having a first surface and a second surface, wherein the second surface of the ink layer 68 is in contact with and adhered to the first surface of the tie coat layer 65 , and a topcoat layer 64 having a first surface and a second surface wherein the second surface of the topcoat layer 64 is in contact with and adhered to the first surface of the ink layer 68 .
[0033] The embodiment illustrated in FIG. 7 illustrates a multilayer laminate 70 which includes a base layer 71 having a first surface and a second surface, a metal layer 72 having a first surface and a second surface wherein the first surface of the metal layer 72 is in contact with and adhered to the second surface of the base layer 71 , an adhesive layer 73 having a first surface and a second surface wherein the first surface of the adhesive layer 73 is in contact with and adhered to the second surface of the metal layer 72 , a polyvinyl halide layer 79 having a first surface and a second surface wherein the first surface of the polyvinyl halide layer 79 is in contact with and adhered to the second surface of the PSA layer 73 , a tie coat layer 75 having a first surface and a second surface wherein the second surface of the tie coat layer is in contact with and adhered to the first surface of the base layer 71 , and a topcoat layer 74 having a first surface and a second surface wherein the second surface of the topcoat layer 74 is in contact with and adhered to the first surface of the tie coat layer 75 .
[0034] The multilayer composite illustrated in FIG. 8 differs from the embodiments illustrated above in that the adhesive layer is replaced by polyvinyl halide layer. In particular, the embodiment illustrated in FIG. 8 illustrate a multilayer laminate 80 which includes a base layer 81 having a first surface and a second surface, a metal layer 82 having a first surface and a second surface wherein the first surface of the metal layer 82 is in contact with and adhered to the second surface of the base layer 81 , a polyvinyl halide layer 89 having a first surface and a second surface wherein the first surface of the polyvinyl halide layer 89 is in contact with and adhered to the second surface of the metal layer, a tie coat layer 85 having a first surface and a second surface wherein the second surface of the tie coat layer 85 is in contact with and adhered to the first surface of the base layer 81 , and a topcoat layer 84 having a first surface and a second surface wherein the second surface of the topcoat layer 84 is in contact with and adhered to the first surface of the tie coat layer 85 .
[0035] [0035]FIG. 9 illustrates another embodiment wherein the multilayer laminate 90 includes a base layer 91 having a first surface and a second surface, a metal layer 92 having a first surface and a second surface wherein the first surface of the metal layer 92 is in contact with and adhered to the second surface of the base layer 91 , a first adhesive layer 93 having a first surface and a second surface wherein the first surface of the first adhesive layer 93 is in contact with and adhered to the second surface of the metal layer 92 , a second PSA layer 93 a having a first surface and a second surface wherein the second surface of the second PSA layer 93 a is in contact with and adhered to the first surface of the base layer 91 , a clear coat layer 99 having a first surface and a second surface wherein the second surface of the clear coat layer 99 is in contact with and adhered to the first surface of the second PSA layer 93 a , a tie coat layer 95 having a first surface and a second surface wherein the second surface of the tie coat layer 95 is in contact with and adhered to the first surface of the clear coat layer 99 , and a topcoat layer 94 having a first surface and a second surface wherein the second surface of the topcoat layer 94 is in contact with and adhered to the first surface of the tie coat layer 95 . This embodiment illustrates a multilayer laminate having an internal clear coat layer in addition to the clear topcoat layer to provide added protection to the metal layer.
[0036] Base Layer
[0037] A wide variety of polymer film materials are useful in the base layer of the laminates of the present invention provided that the films are metallizable. As used herein, metallizable means a layer of metal can be applied to a surface of the base layer by techniques known in the industry, and the metal layer adheres to the base layer. For example, the polymer film material may include polymers and copolymers such as polyolefins, polystyrenes, polyamides, polyesters, polycarbonates, polyvinyl alcohol, poly(ethylene vinyl alcohol), polyurethanes, polyacrylates, and fluoropolymers. In one embodiment, the polymer film material is a polyolefin, a polyester or an acrylic polymer which can be metallized.
[0038] The polyolefins which can be utilized as the base film material include polymers and copolymers of ethylene, propylene, 1-butene, etc., or blends of mixtures of such polymers and copolymers. In one embodiment the polyolefins comprise polymers and copolymers of ethylene and propylene. In another embodiment, the polyolefins comprise propylene homopolymers, and copolymers such as propylene-ethylene and propylene- 1 -butene copolymers. Blends of polypropylene and polyethylene with each other, or blends of either or both of them with polypropylene-polyethylene copolymer also are useful. In another embodiment, the polyolefin film materials are those with a very high propylenic content, either polypropylene homopolymer or propylene-ethylene copolymers or blends of polypropylene and polyethylene with low ethylene content, or propylene-1-butene copolymers or blend of polypropylene and poly-1-butene with low butene content.
[0039] Various polyethylenes which may be utilized as the base film material including low, medium, and high density polyethylenes, and mixtures thereof. An example of a low density polyethylene (LDPE) is Rexene 1017 available from Huntsman. An example of a high density polyethylene (HDPE) is Formoline LH5206 available from Formosa Plastics.
[0040] The propylene homopolymers which may be utilized as the base film material in the multilayer composites useful in the invention, either alone, or in combination with a propylene copolymer as described herein, include a variety of propylene homopolymers such as those having melt flow rates (MFR) from about 0.5 to about 20 as determined by ASTM Test D 1238. In one embodiment, propylene homopolymers having MFR's of less than 10, and more often from about 4 to about 10 are particularly useful. Useful propylene homopolymers also may be characterized as having densities in the range of from about 0.88 to about 0.92 μg cm 3 . A number of propylene homopolymers are available commercially from a variety of sources, and some useful polymers include: 5A97, available from Union Carbide and having a melt flow of 12.0 g/10 min and a density of 0.90 g/cm 3 ; DX5E66, also available from Union Carbide and having an MFI of 8.8 g/10 min and a density of 0.90 g/cm 3 ; and WRD5-1057 from Union Carbide having an MFI of 3.9 9/10 min and a density of 0.90 g/cm 3 . Useful commercial propylene homopolymers are also available from Fina and Montel.
[0041] Polystyrenes can also be utilized as the polymer facestock material and these include homopolymers as well as copolymers of styrene and substituted styrene such as alpha-methyl styrene. Examples of styrene copolymers and terpolymers include: acrylonitrile-butene-styrene (ABS); styrene-acrylonitrile copolymers (SAN); styrene butadiene (SB); styrene-maleic anhydride (SMA); and styrene-methyl methacrylate (SMMA); etc. An example of a useful styrene copolymer is KR-10 from Phillips Petroleum Co. KR-10 is believed to be a copolymer of styrene with 1,3-butadiene.
[0042] Polyurethanes also can be utilized as the polymer film material, and the polyurethanes may include aliphatic as well as aromatic polyurethanes.
[0043] The polyurethanes are typically the reaction products of (A) a polyisocyanate having at least two isocyanate (—NCO) functionalities per molecule with (B) at least one isocyanate reactive group such as a polyol having at least two hydroxy groups or an amine. Suitable polyisocyanates include diisocyanate monomers, and oligomers.
[0044] Useful polyurethanes include aromatic polyether polyurethanes, aliphatic polyether polyurethanes, aromatic polyester polyurethanes, aliphatic polyester polyurethanes, aromatic polycaprolactam polyurethanes, and aliphatic polycaprolactam polyurethanes. Particularly useful polyurethanes include aromatic polyether polyurethanes, aliphatic polyether polyurethanes, aromatic polyester polyurethanes, and aliphatic polyester polyurethanes.
[0045] Examples of aliphatic polyether polyurethanes include Sancure 2710® and/or Avalure UR 445®, Sancure 878®, NeoRez R-600, NeoRez R-966, NeoRez R-967, and Witcobond W-320.
[0046] In one embodiment, the base layer may comprise at least one polyester polyurethane. Examples of these urethanes include those sold under the names “Sancure 2060” (polyester-polyurethane), “Sancure 2255” (polyester-polyurethane), “Sancure 815” (polyester-polyurethane), “Sancure 878” (polyether-polyurethane) and “Sancure 861 ” (polyether-polyurethane) by the company Sanncor, under the names “Neorez R-974” (polyester-polyurethane), “Neorez R-981” (polyester-polyurethane) and “Neorez R-970” (polyether-polyurethane) by the company ICI, and the acrylic copolymer dispersion sold under the name “Neocryl XK-90” by the company Avecia.
[0047] Polyesters prepared from various glycols or polyols and one or more aliphatic or aromatic carboxylic acids also are useful film materials. Polyethylene terephthalate (PET) and PETG (PET modified with cyclohexanedimethanol) are useful film forming materials which are available from a variety of commercial sources including Eastman. For example, Kodar 6763 is a PETG available from Eastman Chemical. Another useful polyester from duPont is Selar PT-8307 which is polyethylene terephthalate.
[0048] Acrylate polymers and copolymers and alkylene vinyl acetate resins (e.g., EVA polymers) also are useful as the film forming materials in the preparation of the base layer. Commercial examples of available polymers include Escorene UL-7520 (Exxon), a copolymer of ethylene with 19.3% vinyl acetate; Nucrell 699 (duPont), an ethylene copolymer containing 11% of methacrylic acid, etc.
[0049] Polycarbonates also are useful, and these are available from the Dow Chemical Co. (Calibre) G. E. Plastics (Lexan) and Bayer (Makrolon). Most commercial polycarbonates are obtained by the reaction of bisphenol A and carbonyl chloride in an interfacial process. Molecular weights of the typical commercial polycarbonates vary from about 22,000 to about 35,000, and the melt flow rates generally are in the range of from 4 to 22 g/10 min.
[0050] The base layer is free of filler particles in order to provide a base layer which is clear and transparent. Small amounts of filler particles (organic or inorganic) may be included in some embodiments provided the base layer remains transparent or substantially transparent.
[0051] The thickness of the base layer may be varied over a wide range. In one embodiment, the thickness of the base layer is from about 20 to 125 microns, and in another embodiment from about 40 to 100 microns.
[0052] In some embodiments of this invention the base layer is further characterized as having smooth surfaces. Smooth surfaces are desirable for providing a mirror like finish to the laminate. In one embodiment, the surfaces of the base layer have an average surface roughness (Ra) of less than about 0.4 microns as determined by DIN (German Institute for Standardization) 4768. In other embodiments the Ra is less than about 0.1 micron.
[0053] Metal Layer
[0054] The metal layer comprises a highly reflective metal. The metal also is desirably corrosion resistant and abrasion-resistant. As used herein, the term metal layer refers to a layer that contains metal free of binders such as polymers and resins. The layer is substantially all reflective metal. The metal layer may be applied to the surface of the base layer by any of the techniques known in the art. In one embodiment, the metal layer is applied to the second surface of the base layer by vacuum deposition techniques which bond the metal to the polymeric base layer. In one embodiment, the reflective metal layer has a thickness of from about 1 to about 8 microns and in another embodiment from about 2 to 6 microns. The metal layer may be vacuum-deposited to provide a continuous metal layer although it is possible, in some instances, that the metal can be vacuum-deposited in separate planar reflective segments which are discontinuous, such as dots, but which are deposited so close together that they give the optical visual effect of a continuous, highly reflective metallized surface. Any metal which can be deposited on the second surface of the base layer and which is highly reflective can be utilized in the multilayer laminates of the present invention. Examples of reflective metals include aluminum; nickel; chromium; alloys of chromium and nickel or iron; alloys of aluminum; antimony; tin; platinum; silver; rhodium; platinum; indium and alloys of indium with nickel or tin, etc. It has been observed that aluminum provides a highly reflective surface which simulates a chrome-like product.
[0055] The Adhesive Layer(s)
[0056] The adhesive layer(s) utilized in the present invention may comprise any of a variety of adhesives known in the art and used in label applications. Typically, the adhesive layer has a thickness of from about 0.4 to about 1.6 mils (10 to about 40 microns). The adhesive may comprise any of a number of known heat-activatable or heat-seal adhesive materials. These are polymer materials which are activated and become tacky on heating. Thus, the heat-activatable adhesive layer may comprise any heat-activatable adhesive or thermoplastic film material. Such materials include but are not limited to the following film-forming materials used alone or in combination such as polyolefins, (linear or branched), metallocene catalyzed polyolefins, syndiotactic polystyrenes, syndiotactic polypropylenes, cyclic polyolefins, polyacrylates, polyethylene ethyl acrylate, polyethylene methyl acrylate, acrylonitrile butadiene styrene polymer, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate copolymers, polyamides such as nylon, polystyrenes, polyurethanes, polysulfones, polyvinylidene chlorides, polycarbonates, styrene maleic anhydride polymers, styrene acrylonitrile polymers, ionomers based on sodium or zinc salts of ethylene/methacrylic acid, cellulosics, fluoroplastics, polyacrylonitriles, and thermoplastic polyesters. More specific examples are the acrylates such as ethylene methacrylic acid, ethylene methyl acrylate, ethylene acrylic acid and ethylene ethyl acrylate. Also, included are polymers and copolymers of olefin monomers having, for example, 2 to about 12 carbon atoms, and in one embodiment 2 to about 8 carbon atoms. These include the polymers of a-olefins having from 2 to about 4 carbon atoms per molecule. These include polyethylene, polypropylene, poly-1-butene, etc. An example of a copolymer within the above definition is a copolymer of ethylene with 1 -butene having from about 1 to about 10 weight percent of the 1-butene comonomer incorporated into the copolymer molecule. The polyolefins include amorphous polyolefins. The polyethylenes that are useful in the heat seal layer include those with various densities including low, medium and high density ranges. The ethylene/methyl acrylate copolymers available from Chevron under the tradename EMAC can be used. These include EMAC 2260, which has a methyl acrylate content of 24% by weight and a melt index of 2.0 grams/10 minutes @ 190° C., 2.16 Kg; and EMAC SP 2268T, which also has a methyl acrylate content of 24% by weight and a melt index of 10 grams/10 minutes @ 190° C., 2.16 Kg. Polymer film materials prepared from blends of copolymers or blends of copolymers with homopolymers are also useful.
[0057] Also, the heat activatable first adhesive layer may contain antiblock additives (such as silica, diatomaceous earth, synthetic silica, glass spheres, ceramic partides, etc.) This layer also may contain an antistatic additive (such as an amine or an amide or a derivative of a fatty acid).
[0058] The first and second adhesive layers may be in one embodiment pressure-sensitive adhesives (PSA). PSAs suitable for use in the multilayer laminates of the present invention are commonly available in the art. PSAs include silicone-based PSA adhesives and acrylic based PSAs as well as other elastomers such as natural rubber or synthetic rubber-containing polymers or copolymers of styrene, butadiene, acrylonitrile, isoprene and isobutylene. PSAs are also well known in the art, and any of the known adhesives can be used in the multilayer laminates of the present invention. In one embodiment, the PSAs are based on copolymers of acrylic acid esters, such as, for example, 2-ethyl hexyl acrylate, with polar comonomers such as acrylic acid.
[0059] In the embodiments wherein a pressure sensitive adhesive layer is in contact with and adhered to the second surface of the metal layer, the adhesive layer generally is first coated on a carrier sheet such as a release liner and dried on the release liner. Thereafter, the dried adhesive layer and liner are brought into contact with the second surface of the metal layer. The adhesive layer bonds to the second surface of the metal layer, and the release liner may be left on the PSA until just prior to application of the multilayer laminates of the present invention. The release liner provides protection to the PSA until the laminate is to be applied to a substrate.
[0060] In those embodiments containing two adhesive layers (e.g., FIGS. 4 and 9), the second PSA layer also may be applied by first casting the pressure sensitive adhesive on a smooth surfaced polyester casting sheet in a separate operation. The adhesive coat is dried to produce a smooth surface, and the adhesive coat is then laminated to the first surface of the base layer. The adhesive layer is transferred to the first surface of the base layer, and upon removal of the casting sheet, the adhesive remains adhered to the first surface of the base layer. Casting the adhesive in a separate step on a smooth polyester carrier produces a sufficiently smooth surface for the PSA layer that the DOI of the finished product is not significantly effected by the presence of the second PSA layer. In those embodiments containing a second PSA layer above and in contact with the first surface of the base layer, the PSA does not contain any, or only a small amount of filler (organic or inorganic) particles since it is desirable that the second adhesive layer is clear and transparent. Small amounts, e.g., 0.1 to 5% by weight of filler particles may be included provided the PSA layer remains transparent.
[0061] Clear Polymer Topcoat Layer
[0062] The topcoat layer, sometimes referred to as an overcoat layer, provides desirable properties to the multilayer laminate of the present invention. The presence of the clear and transparent topcoat layer protects the laminate from, for example, weather, sun, abrasion, moisture, water, etc. In addition, the transparent topcoat layer can enhance the optical properties of the multilayer laminate and can provide a glossier and richer image. The polymer topcoat layer can be applied to the multilayer laminates by techniques known to those skilled in the art. Thus, the polymer film may be deposited (direct coating) from a solution, applied as a preformed film (laminated to the structure), such as by transfer lamination, etc. In one embodiment, the thickness of the topcoat layer is in the range of from about 5 to about 50 microns (0.2 to about 2 mils). In another embodiment, the thickness of the topcoat layer is from about 15 to about 40 microns.
[0063] In one embodiment, the clear topcoat layer is a transparent thermoplastic synthetic resinous composition directly coated in thin film form in a liquid state onto the surface of another layer (e.g., base layer, tie coat layer, etc.). Heat is later applied to the clear coat to dry it. The clear topcoat produces a multilayer laminate useful as an exterior film, which, in combination with the underlying layers and, particularly the metal layer, produces a multilayer laminate having highly reflective characteristics, and these laminates are useful in exterior paint applications.
[0064] A variety of clear polymer films can be utilized as the clear topcoat layer in the multilayer laminates of the present invention. Thus, the topcoat layer may comprise polyolefins, thermoplastic polymers of ethylene and propylene, polyesters, polyurethanes, polyacrylates, polymethacrylates, polyvinyl chlorides, fluoropolymers and mixtures thereof. The polymers described as useful in the base layer can be utilized in formation of the topcoat layer provided they have the above properties described as useful in the topcoat.
[0065] In one embodiment, the clear topcoat layer comprises a mixture or an alloy of a thermoplastic fluorinated polymer and an acrylic polymer or copolymer. The clear topcoat layer may contain the fluorinated polymer and the acrylic polymer as the principal components. In one embodiment, the composition of the mixture comprises from 30 to 70% by weight of the fluorinated polymer and from 30 to 70% by weight of the acrylic polymer. In one embodiment, the fluorinated polymer component is a thermoplastic fluorocarbon resin such as polyvinylidene difluoride (PVDF). The fluorinated polymers also may include copolymers and terpolymers of vinylidene fluoride or polyvinyl fluoride, or mixtures thereof. A group of thermoplastic fluorocarbons which are useful as the topcoat layer in the multilayer laminates of the present invention are the PVDF's available from Elf Atochem under the trademark KYNAR. Generally, high molecular weight PVDF resins, with a weight average molecular weight of about 200,000 to about 600,000 can be utilized in the present invention. Specific examples of such PVDFs available from Elf Atochem include KYNAR 301 F (believed to have a weight average molecular weight (Mw) of about 465,000); KYNAR 500 (Mw=465,000); KYNAR 711 (Mw=200,000); KYNAR 741 (Mw=282,000); KYNAR 761 (Mw=444,000); KYNAR 2800 (Mw=414,000); and KYNAR 2801 (Mw=414,000).
[0066] The acrylic polymer component of the topcoat layer may be any of a variety of acrylic polymers and copolymers. Various acrylic monomers (acrylic acids and esters) can be polymerized and copolymerized with other monomers such as methacrylic acid, ethacrylic acid, methyl methacrylate, methyl ethacrylate, ethyl methacrylate, etc. In one embodiment, the acrylic polymer component of the topcoat layer can be a polymethyl methacrylate (PMMA) or a polyethyl methacrylate (PEMA) resin, or mixtures thereof, including methacrylate copolymer resins and minor amounts of other comonomers. The topcoat can also include minor amounts of block copolymers and compatibilizers to stabilize the blended PVDF and acrylic resin system, and to provide compatibility with the underlying layer.
[0067] Inhibitors, antioxidants and ultraviolet absorbers or light stabilizers also may be included in the clear topcoat formulations. Particularly useful ultraviolet absorbers, inhibitors and antioxidants include benzotriazole derivatives, hydroxy benzophenones, esters of benzoic acids, oxalic acid, diamides, etc. Various benzotriazole derivatives useful as ultraviolet absorbers and stabilizers are described in U.S. Pat. Nos. 3,004,896; 4,315,848; 4,511,596; and 4,524,165. Those portions of these patents which describe the various benzotriazole derivatives are incorporated herein by reference. Useful ultraviolet light stabilizers, inhibitors and antioxidants are available from Ciba-Geigy Corporation under the general trade designation “Tinuvin.” For example, Tinuvin 328 is described as an ultraviolet absorber which is identified as 2-(2′-hydroxy-3′,5′-di-tert-amylphenyl)benzotriazole, and Tinuvin 292 is a hindered amine light stabilizer identified as bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate. Tinuvin 234 is another benzotriazole UV absorber.
[0068] Antioxidants are available from Ciba-Geigy under the general trade designation “Irganox”. For example, Irganox 1010 is tetrakis [methylene (3,5-di-tert-4 hydroxycinnamate] methane. Thermolite 31 is a heat stabilizer from Elf Atochem and is believed to be dioctyl tin bis(isooctylmercaptoacetate). Cyasorb-5411 is a UV absorber available from Cytec and is believed to be 2-(2′-hydroxy-5′-octyl phenyl-)benzotriazole. The amount of antioxidant, UV stabilizer, and/or UV absorber-including in the film-forming mixtures is an amount which is effective for the intended result but does not significantly reduce the clarity of the topcoat layer. Generally, these additives may be present in film-forming mixtures in amounts of from 0 to about 10 pphr or from about 0.1 to about 5 pphr.
[0069] In one embodiment, a component of the acrylic resin contained in the topcoat layer is a medium molecular weight (MW 300,000) PEMA resin such as Elvacite 2042 (duPont). Other useful acrylic resins available under the trade designation Elvacite include Elvacite 2008 (a PMMA); Elvacite 2010, a medium molecular weight PMMA resin; Elvacite 2021, a medium-to-high molecular weight PMMA resin; Elvacite 2043 a low molecular weight PEMA resin; and mixtures of two or more such Elvacite resins. In general, the acrylic resin component has a weight average molecular weight of from about 50,000 to about 400,000.
[0070] The acrylic resin component of the clear topcoat layer is desirable because of its compatibility with PVDF in dry film form. The acrylic resin also is added in an amount that yields a transparent clear coat in dry film form. Generally speaking, transparency and DOI of the topcoat formulation increases in proportion to the amount of acrylic resin added to the PVDF-acrylic system. It has been observed that a pure PVDF clear coat has reasonably good properties, but such a coating is not normally transparent. When sufficient acrylic resin is added to the PVDF component, the resulting clear coat becomes reasonably transparent. Increased transparency of the clear topcoat layer improves the gloss level and DOI of the finished laminates of the invention. The acrylic resin is also combined with the PVDF in amounts that maintain sufficient elongation to allow the clear topcoat (and the remainder of the multilayer laminate) to be applied to complex three dimensional shapes while retaining the exterior automotive durability properties and appearance properties, including gloss and DOI. In one embodiment, the acrylic component comprises from about 30% to about 60% by weight of the total solids contained in the topcoat formulation.
[0071] The PVDF and acrylic based topcoat formulation can be prepared as a dispersion of the PVDF in a solution of the acrylic resin. In one embodiment, the topcoat formulation is prepared by mixing the acrylic resin with a suitable organic solvent and applying heat to dissolve the resin. This mixture is then cooled sufficiently before adding the PVDF component so that the PVDF will not dissolve but will be maintained as a dispersion in the acrylic-solvent based mixture. By maintaining the PVDF component as a dispersion in the topcoat, solvent evaporation during drying of the topcoat can be improved. Suitable solvents which can be used are solvents which are inert to the mixture.
[0072] The film-forming mixtures used to form the binder layer generally will contain one or more solvents which are inert to the mixture. The solvents should selected so that they will vaporize after being coated onto a surface in a thin film. Examples of solvents include esters such as ethyl acetate, butyl acetate, amyl acetate, 2-ethoxyethyl acetate, 2-(2-ethoxy)ethoxyethylacetate, 2-butoxyethyl acetate, heptyl acetate and other similar esters, hydrocarbons such as toluene and xylene, ketones, such as acetone, methyl ethyl ketone, butyrolactone, and cyclohexanone, chlorinated solvents, nitro aliphatic solvents, dioxane, etc. The amount of solvent in the film-forming mixture may be varied over a wide range such as from about 3% to about 75% by weight, more often, from about 40-75% of the solid components.
[0073] The PVDF and acrylic-based clear topcoat formulation also can be prepared as a solution of PVDF and acrylic resin in a solvent such as those listed above. In some embodiments multilayer laminates in which the topcoat layer has been prepared from a solution of PVDF in acrylic resin have demonstrated high levels of gloss and DOI.
[0074] Polymer Tie Coat
[0075] In some embodiments of the present invention, an adhesion-promoting polymer tie-coat layer may be introduced between various layers of the multilayer laminates of the present invention. The tie coat layer provides improved bonding strength and reduces the risk of delamination when the adherence of one layer to another may be insufficient. Suitable polymer tie-coat layers can be formed from compositions comprising an adhesion promoting material and, optionally, a suitable solvent. The thickness of the tie coat may be varied, and in one embodiment, the thickness is from about 0.01 to about 0.4 mil. In another embodiment the thickness of the tie coat is from about 0.04 to about 0.1 mil. The tie coat is essentially transparent so that the reflective metal layer is visible through the tie coat layer. Tie coat layers are especially useful for enhancing interlayer bonding between layers in the multilayer laminates of the present invention where the adjacent layers are comprised of different polymers. In one embodiment, useful polymer tie coat layer materials include polyolefins, polyacrylates, polyvinyl acetals such as the Butvar resins from Solutia, polyurethanes, polyesters or polyvinyl carboxylates. In one embodiment, the polymers and copolymers are derived from acrylic acid, alkyl acrylic acid, alkyl acrylic acid esters and acrylic acid esters. A variety of commercially available adhesion promoting species are available, and these are useful in the present invention. In one embodiment, the tie coat layer material may be an acrylic resin which is available from duPont under the general trade designation Elvacite. One example of such a material is Elvacite 2042 which comprises a polyethyl methacrylate (PEMA) resin with a weight average molecular weight of 300,000. Useful polyacrylates are also available from Rohm & Haas under the designation Acrylic M1-7 and from ICI under the designation Acrylic H1-7. Other commercially available adhesion promoting species useful in forming the tie-coat layer of the present invention include, for example, those known under the trade designations Formvar 7/95, Formvar 15/95, Butvar B-98 and Butvar B-72 sold by Monsanto, Mobay M-50 sold by Solutia, Vinac B-15 sold by Air Products and Lexan sold by General Electric. Other useful adhesion promoting materials useful in forming the tie-coat layers include copolymers derived from: acrylonitrile, vinylidene chloride, and acrylic acid; and polymers derived from methyl methacrylate, vinylidene chloride and itaconic acid. Suitable solvents which may be used in conjunction with the adhesion promoting species include methylethyl ketone, methylene chloride, tetrahydrofuran, toluene, methyl cellosolve, methanol, ethanol, propanol, butyanol, mixtures thereof, etc.
[0076] More than one adjacent tie coat layer may be utilized to improve the adhesion of adjacent layers in the multilayer laminates of the present invention. When more than one tie coat layer is provided, the first tie coat is dried before the second tie coat layer is applied.
[0077] In the embodiments of the present invention which are illustrated in FIGS. 2, 7 and 8 , a tie coat layer is adhered to the first surface of the base layer. In those embodiments, the tie coat layer improves the adhesion between the topcoat layer and the base layer. In the embodiment illustrated in FIG. 5, the tie coat layer 55 improves the adhesion of the first surface of the base layer 51 to the second surface of the barrier layer 56 . In the embodiment illustrated in FIG. 6, the tie coat layer 65 improves the adhesion between the first surface of the base layer 61 and the second surface of the ink layer 68 . In the embodiment illustrated in FIG. 9, tie coat layer 95 is utilized to improve the adhesion of the first surface of the clear coat layer 99 to the second surface of the topcoat layer 94 .
[0078] Some of the base layers as utilized in the present invention are available commercially with a preapplied tie coat layer. For example, a polyethylene terephthalate (PET) clear 2 mil film is available from ICI Corporation containing an acrylic tie layer on one surface of the PET film. This product is available from ICI under product number ICI 453. Another 2 mil PET film commercially with an acrylic tie layer on one surface is available from SKC Corporation under the product number SH 81.
[0079] As noted above, the tie coat layers utilized in the present invention are clear and transparent layers. Thus, the tie coat layer does not contain filler particles such as organic or inorganic fillers, or if fillers are present in the tie coat layer, they will be present in such small quantities as to not deliteriously effect the transparency of the tie coat layer.
[0080] Barrier Layer
[0081] In certain embodiments of the present invention, the multilayer laminates may contain one or more barrier layers. A barrier layer when used herein should be substantially impermeable to the migration of any migratory components in the layers on either side of the barrier layer. The term “substantially impervious” is used herein to refer to a barrier layer with at least about 90% barrier properties. In one embodiment, the barrier layer has at least about 95% barrier properties, and in a further embodiment, at least about 98%. Examples of migratory components include monomeric and polymeric plasticizers, coloring agents and other deleterious agents. Examples of plasticizers which may be included in layers comprising polyvinyl chloride include plasticizers such as monomeric plasticizers such as dioctyl phthalate and dioctyl terephthalate.
[0082] The barrier layer is essentially a continuous layer. The thickness of the barrier layer may vary over a wide range. In one embodiment, the thickness of the barrier layer is from about 2 to 10 microns. In another embodiment, the thickness is from 4 to about 8 microns.
[0083] Illustrative examples of useful barrier materials include, but are not limited to, the following: polyesters, epoxy resins, phenolic resins, polyurethanes, amino resins, acrylic resins, nylon, polyvinylidene dichloride (e.g., Saran from Dow Chemical Company), ethylene vinyl alcohol, polyvinyl fluoride, and mixtures thereof. In one embodiment, the barrier layer may be a biaxially-oriented, heat-set polyester which typically exhibits high strength, durability, weather resistance and impermeability to plasticizers, and is typically substantially dimensionally stable.
[0084] Thermosetting epoxy resins also are useful in the barrier layer and they include any of a number of well-known organic resins which are characterized by the presence therein of the epoxide group
[0085] A wide variety of such resins are available commercially. Such resins have either a mixed aliphatic-aromatic or an exclusively non-benzeneoid (i.e., aliphatic or cycloaliphatic) molecular structure.
[0086] The mixed aliphatic-aromatic epoxy resins which are useful with the present invention are prepared by the well-known reaction of a bis(hydroxy-aromatic) alkane or a tetralds-(hydroxyaromatic)-alkane with a halogen-substituted aliphatic epoxide in the presence of a base such as, e.g., sodium hydroxide or potassium hydroxide. Under these conditions, hydrogen halide is first eliminated and the aliphatic epoxide group is coupled to the aromatic nucleus via an ether linkage. Then the epoxide groups condense with the hydroxyl groups to form polymeric molecules which vary in size according to the relative proportions of reactants and the reaction time.
[0087] In lieu of the epichlorohydrin, one can use halogen-substituted aliphatic epoxides containing about 4 or more carbon atoms, generally about 4 to about 20 carbon atoms. In general, it is preferred to use a chlorine-substituted terminal alkylene oxide (terminal denoting that the epoxide group is on the end of the alkyl chain) and a particular preference is expressed for epichlorohydrin by reason of its commercial availability and excellence in forming epoxy resins useful for the purpose of this invention.
[0088] If desired, the halogen-substituted aliphatic epoxide may also contain substituents such as, e.g., hydroxy keto, nitro, nitroso, ether, sulfide, carboalkoxy, etc.
[0089] Similarly, in lieu of the 2,2-bis-(p-hydroxyphenyl)-propane, one can use bis-(hydroxyaromatic) alkanes containing about 16 or more carbon atoms, generally about 16 to about 30 carbon atoms such as, e.g., 2,2-bis-(1-hydroxy-4-naphthyl)-propane; 2,2-bis(o-hydroxyphenyl)propane; 2,2-bis-(p-hydroxyphenyl) butane, 3,3-bis-(p-hydroxyphenyl)hexane; 2-(p-hydroxyphenyl)-4-(1-hydroxy-4-naphthyl)octane, 5-5-bis-(p-hydroxy-o-methylphenyl)-decane, bis-(p-hydroxyphenyl) methane,2,2-bis-(p-hydroxy-o-isopropylphenyl)propane,2,2-bis-(o,p-dihydrox yphenyl)propane, 2-(p-hydroxyphenyl)-5-(o-hydroxyphenyl)hexadecane, and the like. If desired, the bis-(hydroxyaromatic)alkane may contain substituents such as, e.g., halogen, nitro, nitroso, ether, sulfide, carboalkoxy, etc. In general, it is preferred to use a bis-(p-hydroxyphenyl)alkane since compounds of this type are readily available from the well-known condensation of phenols with aliphatic ketones or aldehydes in the presence of a dehydrating agent such as sulfuric acid. Particularly preferred is 2,2-bis-(p-hydroxyphenyl)propane, which is available commercially as “Bisphenol A”.
[0090] Epoxy resins of the type described above are available from a wide variety of commercial sources. One group is known by the general trade designation “Epon” resins and are available from Shell Chemical Co. For example, “Epon 820” is an epoxy resin having an average molecular weight of about 380 and is prepared from 2,2-bis-(p-hydroxyphenyl)propane and epichlorohydrin. Similarly, “Epon 1031” is an epoxy resin having an average molecular weight of about 616 and is prepared from epichlorohydrin and symmetrical tetrakis-(p-hydroxyphenyl)ethane. “Epon 828” has a molecular weight of 350-400 and an epoxide equivalent of about 175-210.
[0091] Another group of commercially available epoxy resins are identified under the general trade designation EPI-REZ (Celanese Resins, a Division of Celanese Coatings Company). For example, EPI-REZ 510 and EPI-REZ 509 are commercial grades of the diglycidyl ether of Bisphenol A differing slightly in viscosity and epoxide equivalent.
[0092] Another group of epoxy resins are available from Fume Plastics Inc., Los Angeles, Calif. under the general trade designations EPIBOND and EPOCAST. For example, EPIBOND 100A is a one component epoxy resin powder available from Furane which is curable to a hard resin in the absence of any hardener.
[0093] Liquid forms of epoxy resin are also useful. These liquid forms normally comprise very viscous liquids requiting some degree of heating to permit withdrawal from storage containers. Certain “D.E.R.” resins obtainable from Dow Chemical Company and “Epotuf” liquid epoxy resins obtainable from Reichhold Chemicals Inc. are examples of such resins preferred for employment in accordance with the invention. An example of an “Epotuf” liquid epoxy resin in the undiluted medium high viscosity #37-140 having an epoxide equivalent weight of 180-195, a viscosity (ASTM D445) of 11,000-14,000 cps at 25° C., and a Gardner Color Maximum of 3. This is a standard general purpose epoxy resin.
[0094] Epoxy resins such as Araldite 6010, manufactured by Ciba-Geigy or epoxy resins identified as Shell Product No. 828 can be utilized. These epoxy resins are of the glycidyl-type epoxide, and are preferably diglycidyl ethers of bis-phenol A which are derived from bis-phenol and epichlorohydrin.
[0095] In another embodiment, the barrier layer may be a radiation cured cross linked cycloaliphatic epoxide derived from at least one cycloaliphatic epoxy compound, at least one polyol and at least one photoinitiator. The barrier layer is sufficiently flexible so as to not crack, split or separate when the inventive laminate construction is bent or flexed during its normal use.
[0096] The cycloaliphatic epoxy compounds or polyepoxides that can be used are known and are described in U.S. Pat. No. 3,027,357. The portion of U.S. Pat. No. 3,027,357 beginning at column 4, line 11, to column 7, line 38, is specifically incorporated herein by reference for its disclosure of cycloaliphatic epoxy compounds that are useful. In one embodiment, diepoxides are especially useful. Examples include 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, bis(3,4-epoxy-6-methylcyclohexylmethyl)adipate, bis(3,4-epoxycyclohexylmethyl)adipate, bis(2,3-epoxycyclopentyl)ether, vinyl cyclohexane diepoxide, 2-(3,4-epoxycyclohexyl)-5,5-spiro(2,3-epoxycyclohexane)-m-dioxane, and the like. A commercially available cycloaliphatic epoxy resin that is useful is available under the name Cyracure UVR-6105 or Cyracure UVR-6110, both of which are products of Union Carbide identified as 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate.
[0097] The polyols which may be used include glycols, alkane diols, triols, tetraols, aliphatic ether containing diols, triols, tetraols, cycloaliphatic containing diols, triols, and tetraols, and aromatic containing diols, triols, and tetraols, and the like. Examples of useful polyols include the following: ethylene glycol, diethylene glycol, 2,2,4-trimethyl-1,3-pentanediol, dipropylene glycol, propylene glycol, 2,2-dimethyl-1,3-propanediol, polypropylene glycol having an average molecular weight of about 150 to about 600 and having 2 to 4 terminal hydroxyl groups, triethylene glycol, 1,4-cyclohexanedimethanol, 2,2-dimethyl-3-hydroxypropyl 2,2-dimethyl-3-hydroxy-propionate, 1,3-butanediol, tetraethylene glycol, 2,2-bis(4-hydroxphenyl)propane, and the ethylene and propylene oxide adducts of 2,2-bis(4-hydroxypheny)propane, pentaerythritol, erythritol, glycerine, trimethylolpropane, 1 ,4-butanediol, 1,6-hexanediol, tripropylene glycol, 2,2-bis(4-hydroxycyclohexyl)propane, 1,2,6-hexanetriol, and 1,3-propanediol. The polycaprolactone esters of polyols that can be used include those in which from about 1 to about 5 , and in one embodiment from about 1.5 to about 4 moles of caprolactone are esterified with a polyol such as trimethylol propane or diethylene glycol. The polycaprolactone ester of a polyol can be the polycaprolactone ester of trimethylol propane in which about 1.5 moles of caprolactone are reacted with trimethylol propane. The polycaprolactone ester of trimethylol propane where about 3.6 moles of caprolactone are esterified with trimethylol propane can be used. Also, ester diols and ester diol alkoxylates produced by the reaction of an ester diol and an alkylene oxide can be used. A commercially available polyol that is useful is available under the name Tone 0305, which is a product of Union Carbide identified as e-caprolactone triol.
[0098] The photoinitiator can be any of the aryl sulfonium salts, iodonium salts or iron hexafluorophosphate salts known in the art as being useful as photoinitiators. Commercially available aryl sulfonium salts that are useful include Cyracure UVI-6974 and Cyracure UVI-6990, both of which are products of Union Carbide, and those available from Sartomer under the names SarCat CD 1010, SarCat CD 1011 and SarCat CD 1012. The iodonium salt available from GE Silicones under the name UV 9380C is useful. Irgacure 261, which is an iron hexafluorophosphate salt available from Ciba Geigy can be used. Oxidizing agents such as cumene hydroperoxide and sensitizers such as isopropyl thioxanthone can be used to enhance cure. The amount of photoinitiator that is used is generally about 2% to about 10% by weight based on the total weight of the barrier layer composition, and in one embodiment about 6% to about 9% by weight.
[0099] Other ingredients can be added to the cycloaliphatic epoxy composition to meet specific application requirements. A variety of other epoxides can be blended with cycloaliphatic epoxides to modify viscosity, hardness, flexibility, cure rate, adhesion, and other properties. Surfactants and waxes can be used to improve substrate wetting and surface slip. Polyol additions increase flexibility and increase depth of cure of thick coatings.
[0100] The ratio of epoxide equivalents to hydroxyl equivalents (the R value) is a factor affecting properties of the barrier layer. Compositions with low R value (more hydroxyl equivalents) are typically more flexible and softer. The R value should generally be kept above about 2 to obtain hard, tack-free coatings. Increasing reactant equivalent weight makes compositions more flexible, extensible, and softer; decreasing reactant equivalent weight increases hardness and cure rate. In one embodiment, the value of R is in the range of about 2 to about 100. In another embodiment the value of R is about 2 to about 50, or from about 2 to about 10.
[0101] The cycloaliphatic epoxy composition is in the form of a liquid. It is applied to the surface of a layer of the laminate as a coating by an conventional technique known in the coating art such as roller coating, curtain coating, brushing, spraying, reverse roll coating, doctor knife, dipping, die coating, offset gravure techniques, etc. This liquid may be heated or cooled to facilitate the coating process. The applied coating can be cured by exposure to known forms of ionizing or actinic non-ionizing radiation. Useful types of radiation include ultraviolent light, electron beam, x-ray, gamma-ray, beta-ray, etc. Ultraviolet light is especially useful. The equipment for generating these forms of radiation are well known to those skilled in the art.
[0102] Polyurethane resins also are useful as films in the multilayer laminates of the present invention. Aliphatic or aromatic polyurethanes can be utilized. For example, aliphatic polyurethane resins such as Desmolac 4125, available from Mobay Chemical Company can be utilized. Desmolae 4125 is a reaction product of a cycloaliphatic isocyanate with a polyester resin and is applied in a 20% by weight solid solution in isopropanol and toluene.
[0103] The barrier layer of the present invention may comprise isoeyanate-terminated polyurethane coatings and films which may be applied as comprising an inert organic solvent and an isocyanate-terminated polyurethane and thereafter removing the solvent from the applied solution leaving the desired backcoating or film. The isocyanate-terminated polyurethane polymers are also referred to in the art as “prepolymers,” and these polymers may be formed by the reaction of selected polyols having an average molecular weight of from about 200 to about 2000 with a stoichiometric excess of an organic polyisocyanate. Such prepolymers are capable of chain extension and crosslinking (commonly called curing) with water or other chain-extending agents.
[0104] Any organic compound containing at least two active hydrogen atoms may be reacted with the stoichiometric excess of organic polyisocyanate to form an isocyanate-terminated prepolymer which is then capable of molecular weight increase by curing as described above. The prepolymers may have a free isocyanate content of from about 5% to about 20% by weight based on the prepolymer content.
[0105] Any of a wide variety of organic polyisocyanates can be employed in the formation of the polyurethane prepolymers useful in the invention. Diisocyanates are preferred, but minor amounts of other polyisocyanates can be included. The isocyanates may be aliphatic, aromatic or mixed aliphatic-aromatic isocyanates. The aliphatic and cycloaliphatic diisocyanates are preferred especially when it is preferred to have a non-yellowing urethane backcoating or film. The diisocyanates generally have from about 6 to about 40 carbon atoms, and more often from about 8 to about 20 carbon atoms in the hydrocarbon group. Suitable diisocyanates include the di(isocyanato cyclohexyl)methane, 1-isocyanato-3-isocyanatomethyl-3,3,5-trimethyl cyclohexane, hexamethylene diisocyanate, methylcyclohexyl diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, 2,6-tolylene diisocyanate, 2,4-tolylene diisocyanate, p-phenylene diisocyanate, p,p′-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, etc. The aromatic diisocyanates usually have a lower resistance to the effects of ultra violet light.
[0106] As noted, polyols are preferred as the co-reactant in forming the prepolymers useful as coatings and films in the composites of the present invention. The polyols may be aliphatic, cycloaliphatic, aromatic or mixed structures. The polyols preferred contain a major mount of an aliphatic polyol having a molecular weight of at least about 300. These polyols are diols, including ether diols, triols including ether triols or mixtures thereof. Other polyols having greater than three hydroxy groups may also be used in conjunction with the diols and/or triols. The structure of the polyol is usually hydrocarbon in nature, but other substituents may be incorporated in the hydrocarbon moiety to effect changes in the properties of the resulting prepolymer. The molecular weights of these polyols average up to about 2000 or more but those of 300 to about 1000 average molecular weight are preferred. Examples of polyols useful in the present invention include polyoxyethylene glycols, polyoxypropylene glycols, polyoxybutylene glycols, etc. Useful monomeric glycols include ethylene glycol, propylene glycol, butene diols, 1,6-hexamethylene glycol, etc. Examples of triols include trimethylol propane, trimethylol ethane, glycerol, 1,2,6-hexane triol, etc.
[0107] Hydroxy-terminated polyester materials also are useful hydroxy reactants. Such hydroxy-terminated polyester materials can be prepared by the reaction of one or more of the polyhydroxy materials described above with one or more aliphatic, including cycloaliphatic, or aromatic polycarboxylic acids or esters, and such polyesters can often have hydroxyl values in the range of from about 25 to about 150. Examples of such acids include phthalic acid, adipic acid, sebacic acid, etc.
[0108] The isocyanate-terminated polyurethanes can be prepared by the simultaneous reaction of an excess organic polyisocyanate and polyol, or by reacting part or all of a polyol prior to reaction of the remaining amount of the material with the isoeyanate. Generally, it is preferred to add the polyisocyanate to an essentially inert organic solvent solution of polyol from which all moisture has been removed. The reaction between the polyol and the organic polyisocyanate generally is completed in about 1 to 3 hours in the absence of a catalyst. When a catalyst is used, a reaction period of about 10 minutes to about 3 hours is sufficient. When catalysts are used, they are typically organo tin compounds such as dibutyl tin dilaurate and stannous octoate. Other useful catalysts include tertiary aliphatic and alicyclic amines such as triethylamine, triethanolamine, tri-n-butylamine, etc. Mixtures of catalysts can also be employed.
[0109] The amino resins (sometimes referred to as aminoplast resins or polyalkylene amides) useful as barrier layers are nitrogen-rich polymers containing nitrogen in the amino form,—NH 2 . The starting amino-bearing material is usually reacted with an aldehyde (e.g., formaldehyde) to form a reactive monomer, which is then polymerized to a thermosetting resin. Examples of amino-bearing materials include urea, melamine, copolymers of both with formaldehyde, thiourea, aniline, dicyanodiamide, toluene sulfonamide, benzoguanamine, ethylene urea and acrylamide. Preferred amino resins are the melamine-formaldehyde, melamine alkyd, and urea-formaldehyde resins.
[0110] Condensation products of other amines and amides can also be employed, for example, aldehyde condensates of triazines, diazines, triazoles, guanadines, guanamines and alkyl- and aryl-substituted derivatives of such compounds including alkyl- and aryl-substituted ureas and alkyl- and aryl-substituted melamines. Some examples of such compounds are N,N′-dimethylurea, benzourea, dicyandiamide, 2-chloro-4,6-diamino-1,3,5-triazine and 3,5-diaminotriazole. Other examples of melamine and urea-based cross-linking resins include alkylated melamine resins including methylated melamine-formaldehyde resins such as hexamethoxymethyl melamine, alkoxymethyl melamines and ureas in which the alkoxy groups have 1-4 carbon atoms such as methoxy, ethoxy, propoxy, or butoxymethyl melamines and dialkoxymethyl ureas; alkylol melamines and ureas such as hexamethylol melamine and dimethylol urea. The aminoplast cross-linking resins are particularly useful when another thermosetting resin in the aqueous composition is an alkyd resin, a polyester resin, an epoxy resin or an acrylic resin.
[0111] Melamine resins, and more particularly, melamine-formaldehyde resins may be utilized as the polymer backcoating or removable polymer film of the composite constructions of the present invention. Melamine resins which can be used include those which have been described as highly or partially methylated melamine-formaldehyde resins, high amino melamine-formaldehyde resins, mixed ether and butylated melamine-formaldehyde resins, etc.
[0112] The partially methylated melamine-formaldehyde resins generally contain a methoxymethhyl-methylol functionality such as represented by the following formula I.
[0113] A series of such partially methylated melamine formaldehyde resins is available from American Cyanamid Company under the trade designations CYMEL 370, 373, 380 and 385 resins.
[0114] A series of highly methylated melamine resins containing a methoxymethyl functionality as represented by the following formula II.
[0115] also is available from Cyanamid under the general trade designations Cymel 300, 301, 303 and 350 resins. The various resins in this series differ in their degree of 75%; alkylation and in monomer content. The monomer content in Cymel 300 is about in Cymel 301, about 70%; and Cymel 303, about 58%; and in Cymel 350, 68%.
[0116] High imino melamine resins contain methoxymethyl-imino functionalities such as may be represented by the following Formula III.
[0117] A series of melamine-formaldehyde resins known as high imino resins are available from Cyanamid under the wade designations Cymel 323, 325 and 327.
[0118] Mixed ether and butylated melamine resins are available from Cyanamid under the general trade designations Cymel 1100 resins, and these contain an alkoxy methyl functionality as illustrated by Formula IV.
[0119] wherein R 1 and R 2 may be different alkyl groups such as methyl, ethyl, butyl or isobutyl groups, or both R 1 and R 2 may be butyl groups.
[0120] Cymel 1158 resin is a melamine formaldehyde resin available from Cyanamid which contains butoxy-imino functionality as represented by the following Formula V.
[0121] Other useful amino resins available from Cyanamid under the CYMEL® designation include benzoguanamine-formaldehyde resins (CYMEL 1123 resin), glycoluril-formaldehyde resins (CYMEL 1170, 1171 and 1172) and carboxyl-modified amino resins (CYMEL 1141 and 1125).
[0122] The acrylic resins which may be used in a barrier layer in the invention are obtained by polymerizing a suitable combination of a functional group-containing monomer and another copolymerizable monomer in an ordinary manner. The polymerization temperature is ordinarily between about 60° C. and about 100° C., and polymerization time is usually within a range of about 3 to about 10 hours. Examples of the functional group-containing monomers include hydroxyl group-containing monomers such as beta-hydroxyethyethyl acrylate, beta-hydroxypropyl acrylate, beta-hydroxyethyl methacrylate, beta-hydroxypropyl methacrylate, N-methylol acrylamide and N-methylol methacrylamide; carboxyl group-containing monomers such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, as well as monoesters of maleic acid and fumaric acid with monoalcohols; alkoxyl group-containing monomers such as N-butoxy-methylmethacrylamide and N-butoxymethylacrylamide; and epoxy group-containing monomers such as glycidyl methacrylate, glycidyl acrylate and allyl glycidyl ether. These monomers may be used either alone or in the form of a combination of two or more of them. The functional group-containing monomer is used in an amount of about 5 to about 40% by weight of total monomers. Examples of the monomers copolymerize with these functional group-containing monomers include olefinically unsaturated monomers such as ethylene propylene and isobutylene; aromatic monomers such as styreric, vinyl toluene and alpha-methyl styrene; ester of methacrylic acid and alcohols of 1 to about 18 carbon atoms such as methylmethacrylate, ethylmethacrylate, propylmethacrylate, n-butylmethacrylate, isobutylmethacrylate, cyclohexylmethacrylate, 2-ethylhexylmethacrylate and laurylmethacrylate; vinyl esters of carboxylic acid of about 1 to about 11 carbon atoms such as vinyl acetate, vinyl propionate and vinyl 2-ethylhexylic acid; as well as vinyl chloride, acrylonitrile and methacrylonitrile. They may be used either alone or in the form of a mixture of two or more of them.
[0123] The phenolic resins are any of the several types of synthetic thermosetting resins made by reacting a phenol, cresols, xylenols, p-t-butyl phenol p-phenyl phenol, bis-phenols and resorcinol. Examples of the aldehydes include formaldehyde, acetaldehyde and furfural. Phenol-formaldehyde resins are a preferred class of such phenolic resins.
[0124] The use of barrier layers in the multilayer laminates of the present invention is illustrated in the embodiments shown in FIGS. 3 and 5. In FIG. 3, the barrier layer 36 is positioned between the first surface of the base layer 31 and the second surface of the topcoat layer 34 . Thus, for example, if the topcoat layer 34 comprises a polyvinyl chloride layer containing plasticizers, the barrier layer 36 is effective in preventing the migration of the plasticizers from the polyvinyl chloride layer 34 to the base layer 31 . In FIG. 5, the barrier layer 56 is located between the first surface of the tie coat layer 55 and the second surface of the topcoat layer 54 . The barrier layer 56 prevents or hinders the migration of undesirable components from the topcoat layer to the tie coat layer, and, conversely, the migration of any undesirable components from the tie coat layer 55 to the topcoat layer 54 .
[0125] Clear Coat Layer
[0126] In addition to the above-described layers, the multilayer laminates of the present invention may also contain additional layers between the metal layer and the topcoat layer which are referred to herein as clear layers. The introduction of additional clear layers into the laminates of the present invention may be desirable for one or more reasons such as to obtain a thicker laminate where it is undesirable to merely increase the thickness of one or more of the other layers. As inferred from the name, the clear layer must be a clear and transparent layer and may comprise any of the polymers and copolymers identified above for use in any of the layers. Although the clear layer may contain desirable additives such as stabilizers, compatibilizers, and UV inhibitors, the layer should not contain filler particles, or if filler particles are present, they should not be present in an amount which will significantly effect the transparency of the clear layer.
[0127] Ink Layer
[0128] In one embodiment, such as the embodiment illustrated in FIG. 6, one of the layers of the multilayer laminate of the present invention may be an ink or print layer. It may be desired, in some embodiments, to form a multilayer laminate containing one or more ink layers to provide a multilayer laminate containing a desired partial coloration or words such as, for example, a trade name that will be superimposed over the reflective metal layer. In the embodiment illustrated in FIG. 6 , an ink layer 68 is positioned between the topcoat layer 64 and the tie coat layer 65 .
[0129] The ink layer may be a mono-colored or multi-colored ink layer. The thickness of the ink layer is typically in the range of about 0.5 to about 5 microns, and in one embodiment about 1 to about 4 microns, and in another embodiment about 3 microns. The inks used in the ink layer include commercially available water-based, solvent-based or radiation-curable, especially UV curable, inks. Examples of these inks include Sun Sheen (a product of Sun Chemical identified as an alcohol dilutable polyamide ink), Suntex MP (a product of Sun Chemical identified as a solvent-based ink formulated for surface printing acrylic coated substrates, PVDC coated substrates and polyolefin films), X-Cel (a product of Water Ink Technologies identified as a water-based film ink for printing film substrates), Uvilith AR-109 Rubine Red (a product of Daw Ink identified as a UV ink) and CLA91598F (a product of Sun Chemical identified as a multibond black solvent-based ink).
[0130] In one embodiment, the ink layer comprises a polyester/vinyl ink, a polyamide ink, an acrylic ink and/or a polyester ink. The ink layer is formed in the conventional manner by depositing, by gravure printing or the like, an ink composition comprising a resin of the type described above, a suitable pigment or dye and one or more suitable volatile solvents onto one or more desired areas of lacquer layer. After application of the ink composition, the volatile solvent component(s) of the ink composition evaporate(s), leaving only the non-volatile ink components to form the ink layer. An example of a suitable resin for use in forming a polyester ink is ViTEL® 2700 (Shell Chemical Company, Akron, Ohio)—a copolyester resin having a high tensile strength (7000 psi) and a low elongation (4% elongation). A ViTEL® 2700-based polyester ink composition may comprise 18% ViTEL® 2700, 6% pigment, 30.4% n-propyl acetate (NP Ac) and 45.6% toluene. As can readily be appreciated, ViTEL® 2700 is, by no means, the only polyester resin that may be used to formulate a polyester ink, and solvent systems, other than an NP Ac/toluene system, may be suitable for use with ViTEL® 2700, as well as with other polyester resins. An example of a polyester adhesive composition comprises 10.70%, by weight, ViTEL® 2300 polyester resin; 10.70%, by weight, ViTEL® 2700 polyester resin; 1.1%, by weight, BENZO FLEX S404 plasticizer; 1.1%, by weight, HULS 512 adhesion promoter; 19.20%, by weight, toluene; and 57.10%, by weight, methyl ethyl ketone.
[0131] The adhesion of the ink to a surface of a layer of the multilayer laminate can be improved, if necessary, by techniques well known to those skilled in the art. For example, the surface of the layer to be printed can be corona discharge treated, or a primer can be applied to the surface to be printed.
[0132] Thermoplastic Halogenated Polymer Layer
[0133] In one embodiment of the present invention, such as illustrated in FIG. 7, the multilayer laminates of the present invention may contain a polyvinyl halide layer having a first surface and a second surface wherein the first surface of the polyvinyl halide layer is in contact with the second surface of the PSA layer. In another embodiment of the invention which is illustrated in FIG. 8, the PSA layer in contact with the second surface of the metal layer such as illustrated in FIG. 1 is replaced by a polyvinyl halide layer. The thermoplastic halogenated polymer layer can be adhered to the second surface of the PSA layer in FIG. 7, and to the second surface of the metal layer such as illustrated in FIG. 8, by techniques well known to those skilled in the art such as by extrusion, lamination, etc. The thickness of this layer in one embodiment, is from about 3000 to 8000 microns (120 to 320 mils).
[0134] Various thermoplastic halogenated polymers can be utilized in the present invention, and in one embodiment, thermoplastic chlorinated polymers are utilized. An example of a useful thermoplastic chlorinated polymer is polyvinyl chloride (PVC).
[0135] Release Liner
[0136] The multilayer laminates of the invention may also comprise a release-coated liner having one surface (the release-coated surface) in contact with the otherwise exposed second surface of the adhesive layer. For example, the release coated surface of a release liner may be in contact with the second surface of the adhesive layer in FIGS. 1 - 6 and 9 . The release liner protects the second surface of the PSA layer until the laminate is to be applied to a substrate. The use of a release liner having a smooth surface also ensures that the second surface of the outer layer (i.e., topcoat layer) of the multilayer laminate will have a smooth surface. The presence of a smooth second surface on the outer surface of the laminate enhances the DOI and gloss features of the laminates of the invention. Thus, in one embodiment, polymer films such as polyester films are particularly useful as the liner since such films (e.g., PET films) are available commercially with smooth surfaces. The surfaces of paper liners generally are not as smooth as polymer film liners.
[0137] The release-coated liner may comprise a substrate sheet of paper, polymer film or combinations thereof coated with a release composition. The typical release coating used in the industry is a silicone-based molecule which can be cured either thermally or with irradiation energy such as ultraviolet light or electron beam. Paper substrates are useful because of the wide variety of applications in which they can be employed. Paper is also relatively inexpensive and has desirable properties such as antiblocking, antistatic, dimensional stability, and can potentially be recycled. Any type of paper having sufficient tensile strength to be handled in conventional paper coating and treating apparatus can be employed as the substrate layer. Thus, any type of paper can be used depending upon the end use and particular personal preferences. Included among the types of paper which can be used is paper, clay coated paper, glassine, polymer coated paper, paperboard from straw, bark, wood, cotton, flax, cornstalks, sugarcane, bagasse, bamboo, hemp, and similar cellulose materials prepared by such processes as the soda, sulfite or sulfate processes, the neutral sulfide cooking process, alkali-chlorine processes, nitric acid processes, semi-chemical processes, etc. Although paper of any weight can be employed as a substrate material, paper having weights in the range of from about 30 to about 120 pounds per ream are useful, and papers having weights in the range of from about 60 to about 100 pounds per ream are presently preferred. The term “ream” as used herein equals 3000 square feet. Examples of specific papers which can be utilized as substrates in preparing the deposit laminates of the present invention include 41-pound offset grade bleached Kraft; 78-pound bleached Kraft paper, etc.
[0138] Alternatively, the substrate of the release-coated liner may be a polymer film, and examples of polymer films include polyolefin, polyester, polyvinyl chloride, polyvinyl fluoride (PVF), polyvinylidene difluoride (PVDF), etc., and combinations thereof. The polyolefin films may comprise polymer and copolymers of monoolefins having from 2 to 12 carbon atoms or from 2 to about 4 or 8 carbon atoms per molecule. Examples of such homopolymers include polyethylene, polypropylene, poly-1-butene, etc. The examples of copolymers within the above definition include copolymers of ethylene with from about 1% to about 10% by weight of propylene, copolymers of propylene with about 1% to about 10% by weight of ethylene or 1-butene, etc. Films prepared from blends of copolymers or blends of copolymers with homopolymers also are useful. In addition films may be extruded in mono or multilayers.
[0139] A third type of material used as a substrate for the release liner is a polycoated kraft liner which is basically comprised of a kraft liner that is coated on either one or both sides with a polymer coating. The polymer coating, which can be comprised of high, medium, or low density polyethylene, propylene, polyester, and other similar polymer films, is coated onto the substrate surface to add strength and/or dimensional stability to the liner. The weight of these types of liners ranges from 30 to 100 pounds per ream, with 40 to 94 pounds per ream representing a typical range. In total, the final liner is comprised of between 10% and 40% polymer and from 60% to 90% paper. For two sided coatings, the quantity of polymer is approximately evenly divided between the top and bottom surface of the paper.
[0140] The release coating which is contained on the substrate to form the release-coated liner may be any release coating known in the art. Silicone release coatings are particularly useful, and any of the silicone release coating compositions which are known in the art can be used. In one embodiment, it is desired to have a release coating having a smooth surface.
[0141] Properties/Performance of Laminates
[0142] The multilayer laminates of the present invention are characterized, in one embodiment, as having an exterior distinctness-of-image (DOI) value of at least about 80. In another embodiment, the multilayer laminates of the present invention have an exterior DOI value of at least about 90, and even, in some embodiments, of at least about 95. DOI is a measurement of the clarity of an image reflected by the finished surface of the multilayer laminates. DOI can be measured from the angle or reflection of a light beam from a spherical surface. The maximum DOI reading is 100 units. DOI is measured utilizing a Hunterlab Model No. D47R-6F Dorigon Gloss Meter. A test panel is placed on the instrument sensor and the sharpness of the reflected image is measured. Details of the DOI test procedure used herein are described in ASTM Test D5767-95, which is hereby incorporated by reference.
[0143] The multilayer laminates of the present invention also are characterized as having a high gloss level. In one embodiment, the multilayer laminates are characterized as having an exterior gloss level of at least about 80 gloss units measured with a 60 degree gloss meter by the procedure of ASTM Test E-340. In other embodiments, the gloss level is at least about 100 or at least about 150 gloss units. In yet another embodiment the gloss level is at least about 200 gloss units as measured with a 60 degree gloss meter. In yet another embodiment the gloss level may be up to about 500 gloss units.
[0144] In one embodiment of the present invention, the multilayer laminates may be characterized as having an optical density within the range of from about 1.8 to about 2.2. Optical densities are measured utilizing a MacBeth TR 927 densitometer, using the white filter as set forth in ASTM D-2066, method B.
[0145] In one embodiment, the multilayer laminates of the present invention also may be characterized as having one or more desirable properties such as tensile strength, elongation, adhesion to substrates, abrasion resistance and durability under various moisture and weather conditions. When the multilayer laminates of the present invention are to be utilized in automotive applications, these properties of the multilayer laminates should be sufficient to pass the various tests set forth in the GM 6073M specification. For example, according to Section 5.4 of GM 6073M, multilayer laminates prepared for automotive applications should not show any surface deterioration, objectionable shrinkage, objectionable color or gloss change, delamination, edge lifting, cracking, pitting, blistering or other degradation after exposure to the following tests: Heat aging (paragraph 6.1) thermocycling (paragraph 6.2), humidity (paragraph 6.3), Arizona and Florida exposure (paragraph 6.4), Xenon Arc apparatus (paragraph 6.5), high temperature resistance (paragraph 6.6), and ultraviolet condensation (paragraph 6.7). The test procedure set forth in these paragraphs are hereby incorporated by reference.
[0146] The following examples illustrate the preparation of multilayer laminates in accordance with the present invention. Unless otherwise indicated in the following examples, in the written description, and the appended claims, all parts and percentages are by weight, temperatures are in degrees centigrade and pressure is at or near atmospheric pressure.
EXAMPLE 1
[0147] A high gloss, high DOI chrome-look product is prepared in the following manner. A 2 mil clear polyester (PET) film is purchased from ICI Corporation under the product number 453. In this product, the PET film is coated on one side (first surface) with an acrylic adhesion-promoting tie coat layer. The second surface of the PET film is then vacuum metallized with aluminum. The thickness of the aluminum layer is approximately 2 microns. The exposed surface of the tie coat layer is then coated with the following solvent-based mixture to deposit a clear topcoat layer. The formulation of the solvent-based mixture is as follows:
[0148] Component % By Weight
Component % By Weight PVDF (Kynar 500 +) 20.80 PEMA (Elvacite 2042) 11.20 Cyclohexanone 20.21 Heptyl Acetate 20.21 Butyrolactone 26.86 Tinuvin 900 0.64 Solsperse 17000 0.08
[0149] Solsperse 17000 is available from Zeneca Corp. and is a polymeric fatty acid ester dispersing agent.
[0150] The above solvent-based mixture is applied to the exposed surface of the tie coat layer using a reverse roll coating process. The coating thickness is about 1 mil. The coating is dried in an air circulation oven for 2 minutes at about 177° C. (350° F.).
[0151] Separately, a PSA is coated on a commercially available release-coated 2 mil PET film. The adhesive is Gelva 2837, available from the Solutia Corporation. After drying in an air circulating oven for 90 seconds, the PSA layer has a coating thickness of 30 microns (1.2 mils). As the adhesive coated, release coated PET is removed from the oven, the dried adhesive side is pressure laminated to the exposed surface of the metal layer. This results in the multilayer laminate as illustrated in FIG. 2 with the addition of the release liner in contact with the second surface of the PSA layer 23 . Removal of the release liner results in a multilayer laminate shown as in FIG. 2.
[0152] The initial exterior DOI of the laminate of this Example is 99 and the 60 gloss of over 200 gloss units. When the laminate of this example is subjected to the Florida and Arizona outdoor exposure test for 12 months, there is no significant change in the gloss or the DOI of the sample. The laminate retains its mirror-like reflectance. When the laminate of this example is exposed to a XENON Weather O meter for 2500 hours, there is no significant change in the gloss or DOI of the sample.
[0153] The product of this example also is subjected to moisture resistance tests. The sample passes 240 hours at 95% plus relative humidity at 38° C. The sample also passes a deionized water immersion test at 70° C. for 72 hours. After these tests, the sample is found to have maintained its gloss and DOI. There is no noticeable corrosion of the metallized layer in the moisture resistance test.
[0154] The product of this example also passes a cross hatch adhesion test utilizing 3M 898 tape per GM test number GM9071P. When the adhesion test is performed after the water emersion test, the product passes the cross hatch adhesion test.
EXAMPLE 2
[0155] The general procedure Example 1 is repeated except that the formulation of the polymer solution utilized to form the topcoat layer contains the following components in the amounts indicated.
Component % w Polylite 2 45.00 PVDF 26.00 Solsperse 17000 0.08 Heptyl Acetate 8.68 Cyclohexanone 8.68 Butyrolactone 11.56
[0156] Polylite 2 is a mixture of PEMA and a UV absorber in n-butyl acetate, and this material is available from Avery Dennison Corporation.
[0157] The above solvent based mixture is applied to the exposed surface of the tie coat layer using a reverse roll coating process. In this example, the coating thickness, after drying in an air circulating oven for 2 minutes at 177° C., is about 0.4 mil. The construction which results in this example is the same as in Example 1 except that the topcoat layer is thinner in this Example. The multilayer product has an initial DOI of 99+ and a 60° gloss value of over 200 gloss units.
[0158] The product of this example is subjected to the same weathering and moisture resistance test as listed in Example 1. There is no significant change in the gloss or DOI, nor is there any corrosion of the metallized layer of the multilayer laminate upon completion of the tests.
EXAMPLE 3
[0159] A high gloss, high DOI laminate is prepared in accordance with the procedure Example 1 except that the 2 mil PET layer containing an acrylic tie-coat layer on one side is one that is purchased from SKC Corporation under the general trade designation SH 81.
[0160] While the invention has been explained in relation to its various embodiments, it is to be understood that other modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims. | 4y
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This is a continuation-in-part of application Ser. No. 07/152,012, filed Feb. 3, 1988, now patent No. 5,034,194, which is incorporated herein by this reference.
This invention was made with the government support under Grant Nos. CHE 7616711 and CHE 7921247 awarded by the National Science Foundation. The government has certain rights in this invention.
BACKGROUND OF THE INVENTION
This invention relates to devices for the detection and to devices for rapid mixing of liquid substances in small volumes.
In certain analytical procedures, it is necessary or advantageous to measure properties of liquids present in small volumes. Devices for such purposes are shown in U.S. Pat. Nos. 4,643,570 (Machler, et al) and 4,643,580 (Gross, et al).
Some sample flow cells in the past have had problems with light from an excitation source. See, for example, U.S. Pat. No. 4,037,974, which provides for an opaque mask and/or specially designed sample flow cell with coating material to reduce the problem of light from an excitation source. Furthermore, sampling of small flow volume has presented some difficulties with unwanted introduction of air bubbles. See, for example, U.S. Pat. No. 4,074,940. Another problem arises in having sufficient fluorescence quantum yield for adequate detection which can be solved by a method and apparatus using a stationary phase for sampling as shown in U.S. Pat. No. 4,181,853.
Windowless flow cells by design minimize scattered light. Two previous designs for windowless spectroscopic flow cells have been reported. One design is based upon the suspension of the flowing stream between an outlet capillary tube and a small diameter rod placed directly below the outlet tube. A stationary, but constantly replenished four microliter droplet is formed in the gap between the tube and the rod. The second design is based on directing the flowing stream from a capillary tube across the gap to another capillary tube. The effluent stream is confined by sheathing with a flowing solvent to provide a windowless optical volume of 0.006 to 0.15 microliters.
SUMMARY OF THE INVENTION
It is an object of this invention to provide a liquid film observation apparatus which avoids the interaction of a probing or probed light beam with optical materials which cause undesirable effects such as reflection, scattering, absorption, and background fluorescence.
It is a further object to eliminate sorption of substances in the film onto container walls or desorption of substances from the container walls into the film.
It is another object to provide very small optical dead volumes to achieve resolution of two or more substances contained in two or more small volume elements separated in time in a flowing film.
Another object is to provide an optically thin media useful for the detection of highly absorbing substances and for minimization of undesired absorption effects in luminescence measurements.
An additional object is to provide the ability to study time resolved behavior by probing different regions of a flowing film.
These objectives are achieved by the present invention in which at least two film supports are separated by a small gap. One or more applicators are positioned along the gap. The term film support is defined for this invention as the solid-to-liquid interface that serves as the attachment point for the liquid film. An interconnecting structural member or frame holds the film supports such that there is a gap between the film supports.
Examples of suitable film supports include metallic wires, polymer filaments, and knife edges. The supports may be uncoated, e.g. consist of native metallic oxide, or may have ceramic, organic, or other coatings. The shape and composition of the supports and their spacing is selected such that a continuous liquid film can be sustained in the gap between the supports.
In a preferred embodiment, the supports are wires and each wire has a cross-sectional perimeter that is circular or rectangular. A film is established by initiating fluid flow through at least one applicator abutted near the gap between the wires. Additional applicators are properly spaced and angled alongside the gap to provide liquid that mixes with the liquid film in the gap.
The properly adjusted spacing of the abutted applicator to the gap is determined by the necking length of the liquid that exits the applicator. A spacing near the necking length is required for optimal mixing of the fluids. A spacing of near zero is desired for an alternative configuration that assures minimal mixing for observing streamline flow on the film. The applicator typically consists of a Teflon tube or a pipette tip having an inside diameter not exceeding the width of the gap between the film supports. The angle outlined by line segments representing the intersecting liquid in the applicator with the liquid film in the gap is typically 45° and 90°.
Apparatus is provided for forming a continuous film in the gap, for adjusting the spacing and angle of the supports relative to each other so as to adjust the width and shape of the gap, and for adjusting the spacing and angle between each applicator and the gap. The geometric shape and dimensions of the liquid film suspended or flowing in the gap is determined by the size of the film supports, the width of the gap and the flow rate of the liquid film.
Since the static or flowing-liquid film formed in the gap need not have exterior surfaces, no optical materials are required in the optical path of a probing or probed light beam.
In one embodiment, a flowing-liquid film moves from an applicator tube to a receiving or collection tube.
The gap width can not exceed a critical width above which a continuous liquid film does not form between the film supports.
The film supports can be selected or pre-treated to obtain desired wetting properties or chemical reactivities. The term chemically reactive is defined as a measurable enhancement or inhibition of a measured response by a detector; film supports having this behavior are termed active film supports. For example, a support which contains a detectable or reactive substance that leaches into the film is considered an active film support. Similarly, a support that bears a catalyst is an active support if it effects some detectable property of the film. Film supports without detectable effects on a measured response are termed passive film supports.
The flow cell is suitable for the detection of species directly by chemiluminescence, fluorescence or absorption based measurements such as in a flow injection analysis scheme or stopped flow technique. Versatility also allows direct interfacing to a liquid chromatograph or to the effluent from a gas chromatograph. Furthermore, the mixing characteristics of the properly designed invention suggest its use as a micro-volume mixing or reaction chamber for a variety of experiments.
In one embodiment, a Plexiglas mainframe would contain viewing windows that may or may not contain an optical material above, below and on the side of the examining chamber. Liquids exiting a plurality of reagent applicators, with properly adjusted applicator to film spacings, form a pulsing film.
Another embodiment uses two supports twisted in a helical form with nodes where the two supports are physically joined. A capillary tube is used to transfer the mixed fluid from the cell wire film supports to another location. The enclosed examining chamber also comprises an inlet and outlet for control of the pressure and other environmental conditions in the chamber.
In a preferred embodiment of the windowless flow cell and micro-volume mixing chamber, flowing film returns to a tube confined plug flow (i.e. first in, first out). The tube confined plug flow is accomplished by abutting a wettable reagent applicator tube directly against the flowing film supports. A return to plug flow is desirable when the windowless flow cell or micro-volume mixing chamber is located up-stream from any subsequent detecting or fraction collecting instrumentation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective view of a flow cell according to the present invention.
FIG. 2 is a top view of the upper spacer.
FIG. 3 is a top view of the lower spacer.
FIG. 4a is a top sectional view of the film with drop detector probes.
FIG. 4b is a top cross sectional view of a drop in contact with the drop detector probes.
FIG. 5a is a front cross sectional view of the overflow detector probes.
FIG. 5b is a front cross sectional view with liquid in contact with the overflow detector probes.
FIG. 6 is a detailed cross sectional view of the film.
FIG. 7 is a block circuit diagram of the drop detector probe.
FIG. 8 is a block circuit diagram of the overflow detector probe.
FIG. 9 is a top view of the micro-volume mixing chamber.
FIG. 10 is a front cross sectional view of the mixing chamber along lines 10--10 of FIG. 9.
FIG. 11 is a cross sectional side view of the mixing chamber along lines 11--11 of FIG. 9.
FIG. 12 is a top enlarged view of the upper spacer.
FIG. 13 is a perspective view of helical cell wires.
FIG. 14 is a partial, sectional view showing the transfer of liquid from an applicator to a film.
DETAILED DESCRIPTION
FIG. 1 shows an exploded view of a flow cell in a preferred embodiment which is physically constructed with an upper body plate 1, a mid-body plate 9 into which slides a mirror block 8, a lower body spacer plate 14, and a lower body plate 23. Anchor bolts 4 attach the upper body plate 1, the mid-body plate 9, the lower body spacer plate 14, and the lower body plate 23 together through anchor bolt holes 25.
Film supports 5 consisting of wire are firmly positioned in the upper body plate 1 by upper body film support set screws 3b (not shown) in the upper body set screw holes 3a. The film supports 5 are further positioned in the upper support spacer 6 before passing through the mid-body plate 9 within the Teflon insert 7. The film supports 5 continue through the examining chamber 49, the drop detector probe 19, and the overflow detector probe 20. Within the lower body spacer plate 14 is the lower support spacer 16 through which the film supports 5 pass. The film supports 5 then pass through hole 80 of the drain cavity cover 21 and the drain cavity 28 until fixed by lower body film support set screws (not shown) operating through lower body set screw holes 53a in lower body plate 23.
Fluid flow along the film supports 5 is initiated through the primary reagent port 2a by a primary reagent applicator (not shown). The applicators in the illustrated embodiment are Teflon tubes, but other materials such as glass pipettes would be suitable for some applications. Secondary reagent port 10a is located through mid-body plate 9 and through insert 7. Secondary reagent applicator 10b is positioned within secondary reagent port 10a until "near the film supports" 5. Where "near the film supports" refer to a carefully adjusted film support to applicator spacing. The distance corresponds to approximately 90% of the necking length of the emerging jet stream. When properly adjusted, the falling film will rapidly pulsate. Tertiary reagent port 11a is located within the mid-body plate 9 and directly below secondary reagent port 10a. Tertiary reagent port 11a runs through the mid-body plate 9 also penetrating Teflon insert 7. Tertiary reagent applicator 11b is positioned within tertiary reagent port 11a until "near film supports" 5. Analyte reagent port 54 is located in mirror block 8. Auxiliary port 55a is located in the center of mirror block 8 which corresponds to the geometric center of the examining chamber 49. Similarly analyte reagent applicator (not shown) and auxiliary applicator 55b (see FIG. 14) are appropriately positioned "near film supports" 5. When utilizing any port other than the primary, flow must be initiated in each of these ports prior to the introduction of a flow from the primary port. Air inlet port 12 is cut within mid-body plate 9 through the lower body spacer plate 14 with the accompanying o-rings 15 and through drain cavity cover 21 to the air inlet cavity 27. Fluid flow originating from the primary reagent applicator (not shown), the secondary reagent applicator 10b, and the tertiary reagent applicator 11b flow to the drain cavity 28 located in the lower body plate 23. Drain cavity 28 and air inlet cavity 27 join at drain port 27 to exit from the flow cell. Drain port 26 is attached to a low vacuum source (not shown).
Drain cavity cover 21 is attached to lower body plate 23 by drain cavity cover screws 22. Mounting brackets 50 are attached to mid-body plate 9 by means of bracket attachment screw holes 51.
Mounting brackets 50 can also be attached to other instruments by means of flow cell attachment screw holes 52. Cell probe block 17 is mounted to the lower body spacer plate 14 by means of mounting screw 18. Drop detector probe 19 and overflow detector probe 20 and probe wires 32 are configured around film supports 5 and lead to four wire connectors 24 for appropriate electronic attachments.
FIG. 2 is an enlargement of upper spacer 6 with spacer screw holes 56. The film supports 5 are held in place by upper spacer prongs 29. The upper body plate 1 is machined to receive upper spacer 6. Primary reagent tube 2a rests on film supports 5 close to upper spacer 6.
FIG. 3 is an enlarged view of lower spacer 16 showing two clearance holes 30 through which the film supports 5 pass.
FIG. 4a shows the film 31 held by grounded film supports 5 and encircled by drop detector probe 19.
In FIG. 4b, a drop 33 has formed so that the drop detector probe 19 will activate the circuitry shown in FIG. 7. In general, the drop 33 flows down one of the film supports 5.
FIG. 5a shows the film 31 held by grounded conductive film supports running through the lower spacer 16 located in the lower body spacer plate 14 containing the overflow detector probe 20.
In FIG. 5b, an overflow 77 has occurred resulting in the detection of an overflow condition by the overflow detector probe 20 which in turn activates the circuitry shown in FIG. 8.
FIG. 6 shows a cross section view of the film 31 between the film supports 5. The minimum film thickness 35 is shown, along with the distance between film supports 37 and one half the distance between film supports 36. The circular film support diameter 34 is shown. One half of the additional maximum film thickness 38 is shown.
FIG. 7 shows a block circuit diagram for the drop detector probe 40. A liquid detection chip 39 consisting of a LM 1830 fluid detecting IC chip, provides output to an LED 44 and a trigger chip 43 when the drop detector probe 40 to film support capacitance is shorted by a drop 33. The trigger 43 connects to a timer chip 42 and a decade counter chip 41 which in turn is connected to a microcomputer (not shown). The timer chip 42 is also connected to the decade counter chip 41.
FIG. 8 uses another similar liquid detection chip 39 with the overflow detector probe 45 which operates a time-delay circuit 48, trigger chip 43, timer chip 42, and LED 44. Automatic reset 46 is activated with the timer chip 42. The timer chip 42 is connected to a microcomputer (not shown). Also provided is a manual reset button 47.
FIG. 9 is a top view of the proposed micro-volume mixing chamber 58. The mixing chamber top 60 shows a top viewing window 62 through which the top spacer 66 can be seen. The main frame 59 is under the mixing chamber top 60. The top spacer 66 is mounted on the mixing chamber top 60.
FIG. 10 is a front cut-away view of the proposed micro-volume mixing chamber 58. The main frame 59 would have a hollow cylinder 76 through the center portion. The top 60 will attach to the main frame 59. Similarly, the bottom 61 and bottom spacer 67 will attach to the main frame 59. Top viewing window 62 and bottom viewing window 63 would allow viewing throughout the length of the hollow cylinder 76. Side viewing window 64 would allow viewing through the side viewing chamber 74. Proposed pressure regulating inlet/outlet 71 is shown within top 60. The film supports illustrated as wires 5 are shown within the hollow cylinder 76. A capillary exit port 70 is shown between film supports 5 and above bottom spacer 67. Reagent ports 73 are shown.
FIG. 11 is a side view of the proposed micro-volume mixing chamber 58. The front viewing chamber 75 with front viewing window 65 is shown cut into the main frame 59. The full length of the capillary exit port 70 is shown from the film supports 5 through the bottom 61. The pressure regulating gas inlet/outlet 71 is shown with the primary reagent port 72 within the top 60. Additional reagent ports 73 are proposed as shown. Another pressure regulating gas inlet/outlet 71 could be positioned near the bottom 61. The use as an inlet or outlet is determined by whether the gas is heavier or lighter than air. Additionally, pressure can be reduced or increased.
FIG. 12 is a detailed view of the top spacer 66. Film supports 5 would be spaced as illustrated.
FIG. 13 is another embodiment of the film supports 5 where the film supports 5 cross and are joined together at geometrically-shaped nodes 84. The geometrically-shaped nodes 84 act as an aid in mixing the reagents by a process similar to an aerodynamically-shaped wing.
FIG. 14 shows the spacing from a reagent applicator tube to the film 31. The jet stream necking and the spacing from the end of the reagent applicator to the film 31 is about 90% of the necking distance of the emerging jet stream.
In operating the preferred embodiment as a flow cell, a reagent is provided to the primary reagent port 2a by inserting primary reagent applicator which forms a film 31 between the film supports 5. The preferred distance 37 between the film supports 5 is 1.82 millimeters. The examining chamber 49 is 2.5 cm long and the film supports are 30 gauge wires of nichrome. The film 31 will begin flowing between the two film supports 5 and through the Teflon insert 7. If a secondary reagent and/or a tertiary reagent are used, the reagents flow through the secondary reagent tube 10b and the tertiary reagent applicator 11b inserted, respectively, in the secondary reagent port 10a and the tertiary reagent port 11a through the Teflon insert 7 and finally onto the film supports 5 prior to the initiation of flow from the primary applicator through the primary reagent port 2a which form the film 31.
When operating in a flowing film mode, such as the fixed-applicator downflow mode illustrated, flow is first initiated through the downstream-most applicator. Then, each successive applicator is activated. The last applicator activated is the primary applicator which is the most upstream source of liquid for the flowing film. As an alternative, applicator flow can be started in any order if the applicators are first spaced an inoperative distance away from the gap and then moved closer until liquid from the applicators starts to enter the gap.
The film 31 flows through the examining chamber 49 and through the drop detector probe 19. The lower spacer 16 causes the film 31 to divide and flow down each film support 5 to the drain cavity 28.
Air is provided to air inlet port 12 which flows through the mid-body plate 9, o-ring 15, lower body spacer plate 14, o-ring 15, and the drain cavity cover 21 into the air inlet cavity 27. Drain port 26 is connected to a low vacuum source which then removes the air and reagent from the air inlet cavity 27 and the drain cavity 28, respectively, through the drain port 26.
The mounting brackets 50 are attached to a photomultiplier tube housing for continuous flow chemiluminescence measurements.
Referring to FIG. 4b a condition is shown where the film 31 has not formed and a drop 33 is passing through the drop detector probe 19. Referring now to FIG. 7, the liquid detection chip 39 provides an AC signal to the drop detector probe 19. When a drop 33 passes through the drop detector probes 19, the LED 44 will light. The output of the liquid detection chip 39 is debounced by a Schmidt trigger chip 34 and connected to the input of a decade counter chip 41. The drop 33 passing the drop detector probe 19 will increment the decade counter chip 41. If the count reaches 10 prior to the decade counter reset signal derived from the timer chip 42, a signal will become available at the microcomputer output. The timer chip 42 will automatically reset the decade counter chip 41 after a set time delay.
Referring to FIG. 8 and 5b, the overflow conditions are detected by the liquid detection chip 39 through the overflow detector probe 20. A zero to 15 second time delay is initiated by the time delay circuit 48. At the end of the time delay a pulse triggers the timer chip 42. The timer chip 42 will light the LED 44 and deliver an interrupt pulse to the microcomputer interface. The Schmidt trigger chip 43 is used for signal modifications because debouncing is not required for this circuit.
The illustrated flow cell can have many uses. The film established in the cell can be viewed spectroscopically and in other ways. It is possible to probe the film, take samples from the film, and add substances to the film. By placement and control of the applicators, it is possible to establish pulsations and standing waves in the film as a result of drops contacting the film. When an impinging drop contacts a flowing film, it can cause the film to oscillate for several cycles. These methods of use are helpful in certain specific analytical procedures.
For example, devices according to the present invention are useful in reaction rate studies. Droplets of liquid added from secondary applicators will give different measurement results, depending on the rate of liquid application, if they contain a rate-limiting reactant. Thus, if two runs are made to apply liquid at different rates, e.g. by using different diameter applicator tubes, it is possible to detect responses of different intensities if a rate limiting reactant is present in the applied liquid. A comparison of the intensity of the responses and the volumes of applied liquid would also provide information on the rate of reaction.
In the illustrated embodiment, the falling film that is formed is a classic example of a laminar flow region. The diffusion-controlled mixing in a laminar flow region can be enhanced by additional mass transfer processes, establishing a temperature gradient, initiating a rapid chemical reaction, or by mechanical agitation. For the falling-film flow cell, mixing occurs by inducing a mechanical agitation of the falling-liquid film with an intersecting reagent stream from an applicator. This film agitation is the result of rapid pulsations that are produced by the periodic necking of a reagent solution in a gap between the reagent applicator and falling film. This gap or tube-to-film spacing is the critical parameter for obtaining good mixing characteristics.
At the two air-to-liquid interfaces of the film, the film pulsations resulting from the necking appear as periodic swells with a frequency and an amplitude minimum and maximum that define the envelop encompassing both interfaces. Once formed, the amplitude of each pulse is dampened downstream by the loss of energy to the falling film. Thus, the agitation of the film decreases downstream to a degree that the mixing of reagents probably becomes negligible by the third or fourth oscillation.
The frequency of the film pulsations is empirically adjusted by first butting the reagent applicator tube against a previously established falling film. Next, the reagent tube is withdrawn slowly to a position corresponding to a visible turbulence on the film that is discerned by a loss of transparency. The film turbulence and presumably the mixing efficiency increase as the tube is withdrawn slowly to a position corresponding to a visible turbulence on the film that is discerned by a loss of transparency. The film turbulence and presumably the mixing efficiency increase as the tube is withdrawn still further until a gap size is reached where the fluid first breaks contact with the falling film. This withdraw of the reagent tube causes the solution exiting the tube to project beyond the boundaries of the tube leading to a low velocity jet flow. Fluid flow with free boundaries from an orifice, or in this case a reagent applicator tube, is defined as a jet flow. The jet breaks up at a point that is dependent on turbulence in the jet, interfacial tension, density, and viscosity of the fluids. The optimal spacing or gap distance is proportional to the critical length of necking. The critical length for necking of a low velocity jet is believed to be equivalent to a dimension described by the circumference of the tube.
A hypothesis on the cycle that leads to necking is graphically illustrated by the sequence of events that is depicted as stages a through e in FIG. 14. In this example, the applicator 55b is a Teflon tube with a 0.70-mm i.d. Secondary injector fluid 80 is delivered to the film 31. Prior to making contact with the film 31, fluid 80 projected from the applicator 55b occupies a spherical volume 82 of about 4.1 μL. The B-factor for stages a-e is 0.9. For stage f the B-factor is 1.1. Dead time for stages a-b is 0.14 s. The cycle begins and ends at stage a where the meniscus in the reagent tube has returned to its equilibrium position where there are no pressure imbalances at the liquid-to-air interface and the previous droplet has merged downstream with the falling film Stage b shows the cross-section of a spherical droplet that has formed in the gap between the tube and falling film. Since the reagent stream from the tube is isolated from the film, the flow rate and linear velocity are at a minimum. Stages c-e illustrate that portion of the cycle that leads to the mixing of two reagents. If the two intersecting reagents initiate a fast CL reaction, then a CL signal may be detected during this time. The meniscus depicted in stage 3 is in a retracted position due to a snap back of the thread of fluid following droplet break-off. Also, the flow rate and linear velocity are at a maximum since the droplet and film have merged. The meniscus is envisioned to oscillate between this retracted position and a projected position for a very short time prior to returning to the normal or equilibrated position shown in stage a. Stage f illustrates the formulation of a droplet that will eventually fall from the tube without making contact with the film. This condition is caused by a tube-to-film gap that is too large.
The proper spacing that leads to efficient mixing can be estimated by first determining the critical period or pulse length to achieve necking. The pulse length, I p , for the initialization of necking in a flowing reagent stream can be estimated from equation (1).
I.sub.p ≈2πr(1)
where r is equal to the internal radius of the reagent applicator tube. For non-wetting materials, the inside diameter is used. For materials that wet the outside diameter is used. The cutting of the Teflon tube tip is typically done at a right angle; however, some solutions required a conical tip to assure the limiting diameter is the inside diameter.
The tube-to-film spacing distance, I s , is equivalent to the product of the spacing factor, B, and I p as shown by equation (2).
I.sub.s ≈B×I.sub.p (2)
The spacing factor has no units, can be empirically derived, and is always less than or equal to one to prevent the formation of droplets. An optimal spacing distance is influenced by the surface tension of the solution in the secondary reagent port and the diameter of the secondary port tube when low flow rates are used. Ideally, the spacing factor should be as small as possible to minimize the resulting dead volume and dead time of the flow cell. The B-factor range that results in good mixing properties is 0.7 to 1.0.
The minimal dead volume and dead time associated with a flow cell are both important parameters if the flow cell is to be coupled to a separation scheme. The dead volume for the illustrated cell is defined as the fluid volume difference between the volume of a sphere that could just occupy the gap and a cylinder that extends across the gap with the same radius as the tube. The dead time is the time required to fill the gap between the tube and film by a flowing stream. The dead volume V d , and dead time, t d , can be estimated from equations (3) and (4), respectively, where F is the flow rate of the solution in the reagent tube.
V.sub.d ≈V.sub.8 -(2 πr.sup.2 I.sub.s) (3)
t.sub.d ≈V.sub.g /F (4)
Therefore, the calculated dead volume and the dead time are 2.6 μL and 0.14 s, respectively, when the experimental conditions are as discussed above regarding FIG. 14. This is near the upper limit for maintaining resolution with microbore HPLC columns.
A new flow cell designed to use an HPLC effluent tube with a 130-μm bore diameter, a flow rate of 0.01 mL/min and a B factor of 0.8 would have a calculated dead volume of 10 nL and a dead time of 0.11 s. Although the design constraints of adjusting a 0.3-mm tube-to-film spacing for such a cell could probably be met, the problems associated with designing a micro-flow cell that could operate with these low flow rates are unknown.
If one desires to avoid or reduce the oscilations which result from the addition of liquid from a secondary applicator, two applicators can be positioned to face one another on opposite sides of the film. A number of different measurement effects can be achieved by adjusting the flow rates of such opposed applicators relative to each other.
When operating in a static film mode, a film is established by initial flow from an applicator, but liquid is not drained or otherwise removed from the film. Static films are typically short lived. But, a static film can be preserved for a substantial period by maintaining the film in a chamber that contains an atmosphere that is substantialy saturated with the liquid which comprises the film.
Referring now to FIGS. 9, 10, 11 and 12, a micro-volume mixing chamber is shown. A plurality of reagents are transported to the film supports to form a film by means of a plurality of reagent ports 72 and 73. Downstream from said ports the homogenous mixture of reagents may then be transferred to other locations by pump or gravity flow. The hollow cylinder 76 could be enclosed by top window 62, bottom window 63, side window 64, and front window 65. Through the use of pressure regulating gas inlet/outlet 71, the environment of the hollow cylinder 76 may be controlled with respect to pressure and type. Additionally, the type of environment may be reactive or passive similar to the film supports 5.
Referring to FIG. 13, it is readily apparent the film will flow down the film supports 5 and be directed to the geometrically-shaped nodes 84 at which point additional mixing of the reagents should occur prior to the formation of film below the geometrically-shaped node 84 or mixing aid. The design of the nodes and the number of nodes placed in line would affect the mixing efficiency.
There are other methods for withdrawing a flowing film from a flow cell or micro-volume mixing chamber. Use of a drain cavity may not be suitable, particularly if liquid in the film must be collected for subsequent analysis at detecting or fraction collecting instrumentation. A collection tube, similar to the illustrated wettable reagent tubes, can be butted against the falling film 31 and the film support 5 at an angle through a reagent port, for example, 55a. Similarly, in the micro-volume mixing chamber, a wettable collection tube can be placed through a reagent port, for example, port 73. Plug flow through the collection tube can be obtained by gravity, if the collection tube is located at the bottom of a downwardly flowing film, or by applying suction to the collection tube.
The illustrated film supports are parallel wires, but the supports could be any bodies that provide opposed, extended edges between which a film can be formed. Knife blades could be used in place of the illustrated wires, the taper of the blades being selected to provide edges which favor film formation. Portions of the blades, other than the edges, can be coated with or made of a nonwetting substance so that liquid is not wicked away from the edges. In particular, a Teflon coating can be provided on portions of the blades away from the edges.
The film support edges need not extend parallel to each other, although a parallel arrangement will be necessary for certain procedures. Nor is it necessary that the edges be static. The edges could comprise films of mercury flowing down along the surfaces of underlying support bodies.
While the particular invention herein shown and described in detail in two preferred embodiments, it is to be understood that they are merely illustrative of the presently preferred embodiments of the invention and that no limitations are intended to the details of construction or design shown other than as defined in the appended claims, which form a part of this disclosure. | 4y
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This application is a division of application Ser. No. 07/830,981, filed Jan. 28, 1992, which is a continuation of prior application Ser. No. 07/152,013, filed on Feb. 3, 1988, now U.S. Pat. No. 5,241,935, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to fuel injectors for internal combustion engines, and particularly to improvements in accumulator-type fuel injectors, including both unintensified and intensified accumulator injectors, which produce improved fuel economy, noise reduction, and reduction of undesirable exhaust emissions, including smoke, oxides of nitrogen, and hydrocarbons.
2. Description of the Prior Art
Accumulator-type fuel injectors have been known in the art for many years, but never have achieved widespread use. It is believed this is because they have heretofore not solved problems present in conventional injectors, and have even introduced additional problems which have been inherent in prior art forms of accumulator injectors.
One serious problem with both conventional fuel injectors and prior art accumulator-type fuel injectors has been premixed burning of the fuel. Typically, about 25-50 percent of the total quantity of fuel injected will be atomized and mixed with air prior to the start of combustion. The sudden combustion of this premixed fuel causes a rapid rate of heat release at the beginning of ignition, with a resulting excessively high noise level, and undesirable exhaust emissions including smoke, oxides of nitrogen, and hydrocarbon emissions. One answer to this problem is to provide a two-stage injection, with a small pilot charge of fuel first injected and ignited, and then the main charge of fuel injected and immediately ignited by the already ignited pilot charge. A system of this type is taught in Loyd U.S. Pat. No. 4,414,940. Although the Loyd system does solve the problem, it requires two separate injectors, one for the pilot charge and another for the main charge, making the system undesirably complicated and expensive.
Another problem with both conventional fuel injectors and prior art accumulator-type fuel injectors is that they produce a fixed spray pattern regardless of engine power demands, and this necessarily compromises engine efficiency at some power settings. For optimum overall engine efficiency, it would be desirable to tailor the spray configuration variably according to the power demands of the engine by having a relatively wide, flat conical spray configuration at relatively low fuel delivery, such as during engine idle, and to have the cone of the spray narrow progressively as the power setting is progessively increased.
The injector needle closure event has been characteristically unsatisfactory in,prior art accumulator-type injectors. Typically, atomization of the fuel has been poor as the needle approaches the seat. Rapid needle closure is required to keep atomization good during the closing event, but the required high speed needle movement has caused needle bounce off of the seat, resulting in secondary and sometimes tertiary injection events, with essentially unatomized fuel dribble being the further result. Both poor atomization and fuel dribble associated with needle closing results in undesirable smoke and high hydrocarbon levels in the exhaust. Prior art accumulator needles have been characteristically long and massive, and if closed at high speed, considerable elastic compressional energy builds up along their lengths upon striking the valve seat, and when this energy is released it causes the needle to bounce off the seat. Examples of accumulator injector needles which are thus undesirably long and massive are found in Falberg U.S. Pat. No. 2,985,378, Berchtold U.S. Pat. No. 4,566,416, Loyd U.S. Pat. No. 4,414,940, Beck et al. U.S. Pat. No. 4,628,881, Vincent et al. U.S. Pat. No. 4,080,942, and in a 1957 publication by Hooker in the Volume 65, 1957 issue of "SAE Transactions," illustrated at page 317. The typical accumulator injector needle mass is on the order of about six grams or more, and with this much mass the energy of momentum of a fast-closing needle is generally too much to avoid needle bounce.
While a short, very lightweight needle is desirable to minimize needle bounce, needle closure damping associated with such short, lightweight needle is also desirable to positively preclude needle bounce in a high speed needle closing event. Applicants are not aware of such closure damping having been addressed in the prior art. It is believed that this is because the prior art has not sought to cure the problem of poor atomization proximate needle closure by means of a high speed needle closing event.
In order to maintain good atomization right up to needle closure, it is also necessary to have a high closing accumulator pressure, and this in turn requires high peak pressure and high average pressure in the accumulator cavity to get the required injection quantity at high power settings. A relatively small accumulator cavity is required for high accumulator pressures. Conventional accumulator injector practice has been to have the accumulator cavity coaxially disposed around the needle, with the needle closure spring disposed within the accumulator cavity. In general, this results in accumulator cavities which are too large for a high pressure accumulator, particularly with the very high pressure in an intensified-type accumulator injector such as that disclosed in the aforesaid Beck et al. U.S. Pat. No. 4,628,881. With the spring located in the accumulator cavity, the only way to reduce the volume of the cavity would be to reduce the size of the spring, and this is just the opposite of what is required for high speed needle closure, namely, a large, strong closure spring. This conventional arrangement with the needle spring concentrically located within the accumulator cavity is seen in Falberg No. 2,985,378, Berchtold No. 4,566,416, Loyd No. 4,414,940, Beck et al. No. 4,628,881, and the aforesaid Hooker publication. Vincent et al. No. 4,080,942 has the needle spring located in a control chamber which receives pressurized fluid for holding the needle down, but this has resulted in the main accumulator chamber being spaced coaxially above the control chamber, a cumbersome arrangement which could not possibly be used in an intensified form of accumulator injector such as that disclosed in the Beck et al. U.S. Pat. No. 4,628,881. For a practical and compact accumulator fuel injector, the accumulator cavity should be arranged closely proximate the spring cavity within a lower portion of the injector, and generally concentrically and thereby compactly-oriented about the spring cavity. This is the only feasible location for the accumulator cavity in an intensified form of accumulator injector.
Pintle spray nozzles having frustoconical deflecting surfaces are known in the fuel injector art, and are common in garden hose nozzles. In hose nozzles, the angle of the spray is manually adjustable by axial movement of the pintle head relative to the orifice. However, no such adjustability has heretofore been known in the fuel injector art, even though automatic adjustment of the spray cone angle to tailor the spray to engine power demands could produce substantial increases in efficiency over the engine power spectrum.
SUMMARY OF THE INVENTION
In view of these and other problems in the art, it is a general object of the present invention to provide a fuel injector for internal combustion engines which produces reduced noise levels and reduction of undesirable exhaust emissions, including smoke, oxides of nitrogen and hydrocarbons.
Another object of the invention is to provide an improved fuel injector for internal combustion engines which substantially eliminates premixed burning and its adverse effects of noise, and undesirable exhaust emissions.
Another object of the invention is to provide a simplified two-stage injection system for first injecting a small pilot or initial charge of fuel which is ignited before injection of the main charge, and then injecting the main charge of fuel which is immediately ignited by the already ignited pilot charge, for elimination of the usual large amount of premixed burning and its adverse effects, the system requiring only a single injector.
Another object of the invention is to provide a fuel injector system which tailors the injection spray configuration variably according to the power demands of the engine for improved efficiency over the full range of power settings, delivering the injected fuel in a relatively wide, flat conical spray configuration at relatively low engine power settings, such as during engine idle, with the cone of the spray narrowing progressively as the power setting is progressively increased.
Another object of the invention is to provide a fuel injector which has a high pressure, high speed needle closing event without material needle bounce and associated secondary and possibly tertiary injections proximate closure, resulting in good atomization right up to closure and substantial elimination of fuel dribble.
Another object of the invention is to provide, in an accumulator-type fuel injector, a needle which is particularly short and light in weight so that it can be moved rapidly in the needle closing event for sharp fuel cutoff, while at the same time it will store only minimal elastic compressional energy when it impacts the valve seat, with resulting minimization of needle closure bounce.
Another object of the invention is to provide, in an accumulator-type fuel injector, a needle closure damper for effectively damping the end of the needle closing event, for positively precluding needle closure bounce.
A further object of the invention is to provide, in an accumulator-type injector, a needle closure damper which is remote from the needle tip and valveseat, thereby permitting efficient shaping of the fiddle tip and valve seat for a high flow coefficient as the needle approaches the seat during closure, maintaining high pressure proximate the seat with resulting good atomization up to closure.
A further object of the invention is to provide, in an accumulator-type injector, an accumulator cavity which is separate and isolated from the needle spring cavity yet is compactly arranged closely proximate the spring cavity within a lower portion of the injector, enabling a large, high speed needle spring to be employed, while at the same time enabling the accumulator cavity to be as small as desired for high pressure accumulator operation, both of which are important factors in achieving fast, crisp needle closure with good fuel atomization and minimum fuel dribble proximate closure.
A further object of the invention is to provide, in an accumulator-type injector, a two-part needle comprising a lower part which engages the valve seat and an upper plunger part which engages the needle during the needle opening event to slow down the opening as a damping factor, but separates from the needle during the needle closing event to minimize needle length and mass for high speed needle closure with minimum bounce from stored elastic compressional energy.
A further object of the invention is to provide, in an accumulator-type injector, novel needle opening stop devices which stop the needle at a small initial "prelift" or "low-lift" increment of lift for a small pilot or initial injection, and then release the needle to its full lift for injection of the main charge.
A further object of the invention is to provide methods for controlling the time interval during which the needle remains in the small prelift or low-lift position for injection of the pilot charge, including adjustably orificing the needle opening vent passage, and adjusting the vent pressure level.
A still further object of the invention is to provide hydraulic circuitry for producing and controlling the time duration of the needle prelift, including a positive stop arrangement associated with such hydraulic circuitry for defining the amount of needle prelift.
Yet a further object of the invention is to provide a novel pintle nozzle arrangement which makes use of the fact that in an accumulator-type injector needle lift is generally proportional to the difference between the accumulator pressures and closing pressures, and hence also to fuel delivery volume, to automatically tailor the cone angle of the spray according to engine power demands, thereby substantially increasing efficiency over the engine power. spectrum.
An additional object of the invention is to improve the flow coefficient proximate the needle tip and seat in an accumulator-type injector by axially guiding the needle closer to the seat for improved repeatability of centering of the needle on the seat upon needle closure, thereby enabling higher closure pressures and consequent better fuel atomization proximate closure.
The present invention provides a series of both method and apparatus advances in the accumulator-type fuel injector art, each of which produces improved engine performance, and when some or all are combined, synergistically produce surprisingly large improvements in engine fuel economy, reduction of noise, and reduction of undesirable exhaust emissions, including smoke, oxides of nitrogen and hydrocarbons. The invention is applicable to both intensified accumulator injectors of the general type disclosed in the aforesaid Beck et al. patent, and unintensified accumulators of the general type disclosed in the aforesaid Beck et al., Falberg, Berchtold and Vincent et al. patents, and Hooker publication.
According to the invention,e injector needle closure speed is increased for sharper fuel cutoff and hence better atomization proximate closure, while at the same time needle bounce off of the valve seat is reduced, to minimize secondary and sometimes tertiary injection events and consequent fuel dribble, by reducing both the mass and the length of the needle. In a preferred form of the invention, reduction of both the closing mass and closing length of the needle is accomplished by dividing the needle longitudinally into a pair of longitudinal sections, a lower needle section and an upper plunger section, which act as a unit during the needle opening stroke, but separate during the closing stroke so that a lower needle section of greatly reduced mass and length operates independently during needle closure.
Needle bounce is also reduced according to the invention by means of hydraulic damping which cushions the end of the needle closure stroke. This is accomplished by providing a damper member that is coupled to the upper end of the needle, or to the upper end of the lower needle portion in the case of the divided needle, located in a fluid-filled cavity, with close-tolerance spacing both peripherally between the damper member and the wall of the cavity and axially under the damper member. The resulting constriction against passage of fluid from under the damper member past the periphery of the damper member produces a hydraulic "squish damping" effect proximate needle closure. The low mass of the needle cooperates with this hydraulic damping in minimization of needle bounce. Preferably, this closure damping cavity is remote from the needle tip and seat, permitting efficient shaping of the needle tip and valve seat for a high flow coefficient and resulting good atomization proximate closure In preferred forms of the invention, this closure damping cavity is also the needle spring cavity which is separate and isolated from the accumulator cavity.
The end of the opening stroke of the needle is also preferably damped according to the invention. This is accomplished by providing a damper cavity just above the upper end of the needle, or in the case of the divided needle, just above the upper end of the upper plunger section. A needle stop and damping plate is located in the damper cavity, having close-tolerance peripheral spacing relative to the wall of the cavity. The cavity has a downwardly facing shoulder against which the upper end of the needle or plunger moves the stop/damping plate to define the fully open needle position, and hydraulic squish damping occurs by constricted flow of fluid around the periphery of the plate and between the plate and this stop shoulder. The opening stroke of the needle may be further slowed down or damped by adding mass to the needle during the opening stroke. This is accomplished by employing the divided needle arrangement referred to above which adds the mass of the plunger to the mass of the needle during the opening stroke, while leaving the plunger behind and removing its mass for the closing stroke.
The accumulator cavity is separated from the needle spring cavity according to the present invention. This enables the accumulator cavity to be made as small as desired for high pressure accumulator operation, while at the same time enabling use of a strong, fast-acting spring for rapid needle closure. Both high accumulator pressure, which enables high closing pressure, and a strong spring for causing fast needle closure are factors which cumulatively contribute to good closure atomization The spring cavity is coaxial of the needle, while the accumulator cavity is spaced radially outwardly from the spring cavity in a lower portion of the injector, which is an optimal location for the accumulator cavity in the intensified form of the invention. The higher the accumulator cavity pressure, the smaller the accumulator cavity must be for the same quantity of fuel injected To accommodate very high accumulator cavity pressures in the intensified form of the invention, the accumulator cavity comprises a plurality of generally parallel accumulator bores peripherally spaced about the spring cavity.
Preferred forms of the present invention embody a two-stage needle lift for first injecting a small pilot charge of fuel which is ignited before injection of the main charge, and then injecting the main charge of fuel which is immediately ignited by the already ignited pilot charge. This eliminates the usual amount of premixed burning and its adverse effects of large noise levels and large levels of undesirable exhaust emissions. The initial needle prelift or low-lift stage may be from about 1 to about 20 percent of maximum needle lift, and the pilot charge is preferably on the order of about 2-20 percent of the full charge.
In some forms of the invention, this two-stage needle lift is accomplished by utilizing a two-stage venting of pressure from above the opening stop/damping plate referred to above to first stop the needle at the prelift position, and then after a sufficient interval of time for injection of the pilot charge, release the needle to move further upwardly for full injection of the main charge.
In other forms of the invention, the two-stage needle lift is accomplished by hydraulic circuits which provide two-stage venting of pressurized fuel from above the needle so as to cause a first low-lift increment of movement of the injector needle, and then in sequence the full lift movement of the needle.
The various two-stage lift forms of the invention are shown and described in connection with intensified forms of the invention, applying the two-stage venting to the low pressure intensifier cylinder so as to control the pressure in the high pressure cylinder. However, such two-stage venting to control the two-stage lift is equally applicable to unintensified forms of the invention, with the venting being from directly above the needle.
The injection spray pattern or configuration may be automatically varied for improved engine efficiency over the engine power spectrum by utilizing a pintle nozzle which is variably controlled according to the quantity of fuel delivered. Use is made of the fact that in an accumulator injector the needle lift is momentarily generally proportional to the difference between opening and closing pressures, and hence also to fuel delivery volume. The pintle nozzle is arranged to deliver a relatively wide, flat cone of spray for low engine power settings, such as at idle, and a narrowing cone of spray for increasing power settings.
A further feature of both the intensified and unintensified forms of the invention is that the needle is axially guided very close to the valve seat, which provides reliable repeatability of needle centering on the seat over a long operational life of the injectors. This enables the needle tip and seat combination to have a high flow coefficient for high pressure closure and consequent good atomization proximate closure.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other objects and advantages of the invention will become more apparent from the following Detailed Description and the accompanying drawings, wherein:
FIG. 1 is an enlarged longitudinal, axial sectional view of an intensified form of the present invention, with the needle shown in the closed position;
FIG. 2 is a transverse section taken on line 2--2 of FIG. 1, looking upwardly;
FIG. 3 is a transverse section taken on line 3--3 of FIG. 1, looking downwardly;
FIG. 4 is a fragmentary longitudinal section, partly in elevation, taken on line 4--4 of FIG. 3;
FIG. 5 is a transverse section taken on line 5--5 of FIG. 4, looking upwardly;
FIG. 6 is a transverse section taken on line 6--6 of FIG. 5, looking downwardly;
FIG. 7 is a transverse section taken on line 7 of FIG. 1;
FIG. 8 is a further enlarged fragmentary longitudinal, axial section of a portion of FIG. 1, showing a first form of the opening stop plate or wafer of the invention which is employed to provide two-stage needle lift;
FIG. 9 is a view similar to a portion of FIG. 8 showing a second form of the stop plate or wafer;
FIG. 10 is a view similar to FIG. 9 showing a third form of the stop plate or wafer;
FIG. 11 is a graph or chart illustrating the two-stage needle lift of the invention;
FIG. 12 shows a lower portion of FIG. 1, but with the needle in its fully lifted position;
FIG. 13 is a view similar to FIG. 12, illustrating closure of the needle separated from the needle plunger;
FIG. 14 is an enlarged longitudinal, axial sectional view, partly in elevation, showing an unintensified form of the invention which has a variable pintle nozzle;
FIG. 15 is a greatly enlarged fragmentary sectional view of the encircled portion of FIG. 14 designated "15", with the needle valve shown in its fully closed position;
FIG. 16 is a view similar to FIG. 15, with the needle valve in a partially opened position;
FIG. 17 is a view similar to FIGS. 15 and 16, with the needle valve in its fully opened position;
FIG. 18 is a diagrammatic illustration of a hydraulic circuit-controlled two-stage needle lift system, shown with its solenoid valve energized and control piston fully extended preparatory to the commencement of an injection event;
FIG. 19 is a view similar to FIG. 18, but with the solenoid valve deenergized to commence the injection event, and with the control piston partially retracted in a first stage needle prelift position;
FIG. 20 is a view similar to FIGS. 18 and 19 with the control piston fully retracted in a second stage full needle lift position;
FIG. 21 is an axial, vertical section of an intensified injector embodying a positive stop piston for defining the needle prelift increment;
FIG. 22 is a diagrammatic illustration of a hydraulic circuit similar to that of FIGS. 18-20 but modified to control the positive stop piston in the injection of FIG. 21; and
FIG. 23 is a view similar to FIGS. 9 and 10, in which the damping plate or member has an axial passage with a slideable pin therein.
DETAILED DESCRIPTION
Intensified Form of the Invention
Referring to the drawings, and at first particularly to FIGS. 1-8 thereof, these figures illustrate an "intensified" or pressure multiplication form of the present invention. The longitudinal axial sectional view of FIG. 1 best illustrates the overall assembly of this form of the invention, while the fragmentary longitudial axial section of FIG. 4 best illustrates the high pressure fuel input to the accumulator cavity.
The intensified form of the invention has particular utility for diesel engines where high overall accumulator pressures and consequent high closing pressure enabled thereby can be beneficial as described hereinafter. Nevertheless, it is to be understood that the intensified form of the invention may also be beneficially employed for engines powered with gasoline or other liquid fuels.
The intensifier-type accumulator injector of the invention is generally designated 10. A control block 12 is disposed at the upper end of injector 10, control block 12 being in communication with a high speed solenoid actuated control valve (not shown). Such control valve may be like the valve 30 shown and described in detail in the Beck et al. U.S. Pat. No. 4,628,881, which is best illustrated in FIGS. 5a, 9 and 10 of that patent. Features which it is desirable to incorporate in the high speed solenoid actuated control valve are covered in jointly owned applications, Ser. No. 823,807 of Robert L. Barkhimer, filed Jan. 29, 1986 for High Cycle Solenoid Valve (now U.S. Pat. No. 4,997,004), and Ser. No. 830,000 of Niels J. Beck, filed Feb. 18, 1986 for Ball Poppet Valve Seat Construction.
Control block 12 is hydraulically connected to such solenoid actuated control valve in a manner similar to the hydraulic connections of the block 110 to the valve 30 in said Beck et al. '881 patent, for an overall mode of operation of the present intensified accumulator injector 10 which is essentially the same as that of the injector of FIGS. 5a, 5b, 9 and 10 of the Beck et al. '881 patent. It is to be noted that in the Beck et al. '881 patent the block 110 serves not only as the upper part of the injector but also as the main body of the valve, whereas control block 12 in the present invention may be attached to an independent valve body or otherwise hydraulically connected to the solenoid actuated valve, remotely if desired.
The flat, transverse lower end surface 14 of control block 12 is lapped to a mating flat, transverse upper end surface 16 of an intensifier body 18, control block 12 and intensifier body 18 being keyed together for correct relative orientation by a pair of locator dowels 20 which are seen in FIGS. 2 and 3. The flat, transverse lower end surface 22 of intensifier body 18 is, in turn, lapped to a flat, transverse upper end surface 24 of an accumulator body 26, intensifier body 18 and accumulator body 26 being keyed together in correct relative orientation by a pair of locator dowels 28 seen in FIGS. 5 and 6. The flat, transverse lower end surface 30 of accumulator body 26 is lapped to a flat, transverse upper end surface 32 of a nozzle body 34 which extends from upper end surface 32 to a lower end generally designated 35. Located in lower end 35 of nozzle body 34 are the injector valve seat 36, sac 38 and injection holes 40.
The control block 12 and intensifier body 18 are clamped together within an upper housing 42, intensifier body 18 being stepped so as to seat within upper housing 42, and control block 12 being threadedly coupled to upper housing 42. The accumulator body 26 and nozzle body 34 are clamped together with a lower housing 44 which is threadedly coupled to intensifier body 18.
A low pressure hydraulic cylinder 46 having a relatively large diameter bore is axially defined within control block 12, and a relatively large diameter, down-cupped low pressure piston 48 is axially slideable within cylinder 46. A coaxial high pressure hydraulic cylinder 50 having a relatively small bore is axially defined within intensifier body 18, extending down through the lower end surface 22 of intensifier body 18. A high pressure piston or plunger 52 having a relatively small diameter is axially slideable within-high pressure cylinder 50. High pressure piston 52 has an upper end cap 54, shown as a flange, which seats inside the low pressure piston 48 against the top wall of the latter. High pressure piston 52 extends downwardly to a flat, transverse lower end 56, and has a reduced diameter lower end portion 57. A cylindrical spring cavity 58 is defined within intensifier body 18, opening through the upper end surface 16 of body 18 into communication with low pressure cylinder 46. Spring cavity 58 is coaxial with cylinder 46 but of smaller diameter so as to provide an upwardly facing shoulder 60 which acts as a stop for downward movement of low pressure piston 48, and consequently also high pressure piston 52 which moves axially down and up as a unit with low pressure piston 48. A piston return spring 62 is disposed within both low pressure cylinder 46 and spring cavity 58, having its lower end seated against the bottom of cavity 58 and its upper end seated against high pressure piston flange 54, biasing flange 54 against the top of low pressure piston 48 so as to effectively couple the pistons 48 and 52 together at all times.
An actuating fluid inlet and vent passage 64 extends axially through the upper portion of control block 12 into communication with low pressure cylinder 46, and provides liquid fuel into low pressure cylinder 46 to drive low pressure piston 48, and hence also high pressure piston 52, downwardly in an intensification stroke from the uppermost position of the two pistons as illustrated in FIG. 1 downwardly to an extent determined by the momentary power demand of the engine, the lowermost positions of the pistons being determined by engagement of the lower lip of low pressure piston 48 against stop shoulder 60. The lowermost position of high pressure piston 52 is the position illustrated in FIG. 4.
Inlet/vent passage 64 also serves as a vent passage through which fluid is vented from low pressure cylinder 46 for initiating and controlling the timing of a small incremental prelift of the needle for injection of a small initial pilot charge, and then full lift of the needle for the main injection. Inlet/vent passage 64 preferably has variable orificing (not shown) for controlling the rate of decay of pressure in low pressure cylinder 46, and hence of the intensified pressure in high pressure cylinder 50, for adjustment of the timing of the prelift and full lift events, as described in detail hereinafter in the description of the operation of the intensified injector 10. The time duration of the prelift phase of the injection event will control the quantity of the pilot charge. Such variable venting by variable orificing or valving of passage 64 affords the opportunity to adjust the prelift portion of the injection while the engine is running by dynamic adjustment of the vent fluid flow. The rate of decay of pressure in low pressure cylinder 46, and hence of the intensified pressure in high pressure cylinder 50, may also be controlled by adjusting the pressure level in the vent line to passage 64, and this may also be done while the engine is running.
To accomplish a downward intensification stroke of pistons 48 and 52, pressurized liquid fuel is passed through inlet/vent passage 64 from the solenoid control valve referred to above at common rail pressure (i.e., regulated pump pressure). For time interval (or time duration or pulse width) fuel metering of the amount of the fuel charge to be introduced into the accumulator, this rail pressure will be the same for each piston stroke, typically on the order of about 1,500 psig, but the length of the time interval during which pressurized fuel is supplied to low pressure cylinder 46 through inlet/vent passage 64 will vary from a relatively short time interval for flow engine power to a relatively long time interval for high engine power. For pressure compressibility fuel metering of the fuel charge to be introduced into the accumulator, the pressure of fuel introduced into low pressure cylinder 46 through inlet/vent passage 64 will be vary according to engine power demands, as for example from about 500 psig at idle to about 1,500 psig at full power.
For either such time duration fuel metering or pressure. compressability fuel metering, or a combination of both, the length of the downward intensification stroke of pistons 48 and 52 will vary according to power demand, the stroke being a relatively short stroke for a relatively low power demand, and a relatively long stroke for a relatively high power demand, with the full power, maximum stroke length being to the high pressure piston 52 position shown in dotted lines in FIG. 1 and shown in FIG. 4. The hydraulic pressure which builds up in low pressure cylinder 46 will be generally proportional to the length of the downward stroke, and the intensified pressure in high pressure cylinder 50 will be higher than the low pressure cylinder pressure in proportion to the cross-sectional area of high pressure piston 48 divided by the cross-sectional area of low pressure piston 52. A satisfactory intensification factor is on the order of about 15:1, produced by a 15:1 area ratio of low pressure piston 48 to high pressure piston 52. For example, with such a 15:1 intensification, a relatively low rail pressure of 500 psig would produce a relatively low engine power intensified pressure of 7,500 psig, while a relatively high rail pressure of 1,500 psig would produce a relatively high engine power intensified pressure of 22,500 psig.
At the engine-timed instant for initiation of an injection event, the solenoid valve shifts to a vent position in which it vents passage 64, and hence low pressure cylinder 46, to a lowered pressure, which may be essentially atmospheric pressure, which enables piston return spring 62 to move both of the pistons 48 and 52 back up to their positions of repose as illustrated in FIG. 1. The manner in-which this causes the injection event to occur will be described in detail hereinbelow.
Pressure relief from within cylinder 46 and spring cavity 58 during the intensification downstroke of the pistons is accomplished through a vent cavity 66 in the upper end of intensifier body 18 and a pair of communicating vent passages 68, seen in FIG. 2, which extend longitudinally upwardly through control block 12 and are vented to essentially atmospheric pressure.
A stepped counterbore is provided in the lower end of high pressure cylinder 50. The relatively large diameter lower portion of this stepped counterbore defines a damper cavity 70 in which a needle stop plate member 71 is disposed. The relatively small upper portion of this stepped counterbore provides a guide for a plate spring 72 which engages the top of plate 71 and biases plate 71 to a normally seated position as shown in FIGS. 1 and 8 with its lower surface peripherally seated flush against the upper end surface 24 of accumulator body 26. The lower surface of plate 71 has a lapped (Sealingly seated) fit against a shoulder formed by upper body surface 24 so as to provide a fluid-tight seal in the normally seated position of plate 71. As a result, the net fluid pressure on the plate 71 is the product of 1) the interface area and 2) the difference between the ambient pressure in cavity 70 and the fluid vapor pressure. Plate 71 is sometimes referred to herein as a needle stop because it serves the function of stopping the opening stroke of the injector needle by abutting against the step or shoulder 73 between the two sections of the stepped counterbore to define the fully open position of the needle. Plate 71 performs two other important functions which will be described in more detail hereinafter. First, while still in its seated position as shown in FIG. 1, at the beginning of the opening stroke, the seated plate 71 enables the needle to open slightly to a prelift or low-lift position but stops the needle in this slightly open position for injection of a small pilot charge; and then after a brief interval of time allows the needle to proceed to its fully open position for injection of the main fuel charge. Plate 71 has a central hole 74 therethrough for admitting intensified pressurized fuel to the region below plate 71 during the intensification stroke and until initiation of injection, for holding the needle column down against the intensified pressure within the accumulator cavity. Second, plate 71 serves as a hydraulic damper for damping the end of the opening stroke of the needle to prevent needle bounce for a more uniform fuel spray in the early part of the injection event. The opening damping effect can be adjusted by adjusting the radial clearance between the periphery of stop plate 71 and the annular surface of damper cavity 70.
A fluid supply conduit 76 continuously supplies fuel to the injector 10 at rail pressure, extending longitudinally down through both control block 12 and intensifier body 18, opening downwardly through the lower end surface 22 of intensifier body 18. Fuel supply conduit 76 supplies fuel to high pressure cylinder 50 for intensification and valving on into the accumulator cavity. A cross-conduit 78 provides communication from fuel supply conduit 76 to high pressure cylinder 50, the other end of cross-conduit 78 being blocked by a high pressure plug 80, such as a "Lee Plug," disposed in a counterbore of the cross-conduit 78.
After the end of each intensification stroke during which high pressure piston 52 has delivered highly pressurized and compressed fuel from high pressure cylinder 50 into the accumulator cavity, when high pressure piston 52 moves back upwardly to its uppermost, rest position as shown in FIG. 1, it draws a vacuum in high pressure cylinder 50 below fuel inlet cross-conduit 78. When the lower end portion 57 of high pressure piston 52 uncovers cross-conduit 78 into communication with high pressure cylinder 50, fuel under rail pressure from supply conduit 76 flows through cross-conduit 78 to fill the void in the lower portion of high pressure cylinder 50.
High pressure cylinder 50 is thus loaded with fuel at rail pressure and is ready for another intensification stroke during which it greatly increases the fuel pressure above rail pressure, compressing the fuel and delivering it to the accumulator cavity. For time interval fuel metering, the amount of increase of pressurization within high pressure cylinder 50 over rail pressure will be determined by the duration of the time interval, and the corresponding length of the stroke of high pressure piston 52 downwardly from its rest position as shown in FIG. 1. For pressure compression metering, the pressure produced by the intensification stroke in high pressure cylinder 50 will be an increase above rail pressure in proportion to the ratio of the transverse area of low pressure piston 48 to the transverse area of high pressure piston 52, since the intensification stroke is timed to enable a substantial equilibrium to be achieved between the downward rail pressure force against the top of low pressure piston 48 and upward intensified fluid pressure force against the lower end.56 of high pressure piston 52, before the injection event is commenced by venting fluid pressure from above low pressure piston 48 through inlet/vent passage 64.
Reference will now be made to FIG. 4 which illustrates the fluid communication from high pressure cylinder 50 into the accumulator cavity. The axial sectional view of FIG. 4 is rotationally offset 135° from the axial section of FIG. 1, this 135° offset being clockwise looking downwardly as in FIGS. 3 and 6. A second radially oriented cross-conduit 82 is located below the upper end of the reduced diameter lower end portion 57 of high pressure piston 52 at the lowermost stroke position of high pressure piston 52 as illustrated in FIG. 4. Cross-conduit 82 defines an outlet port 83 from high pressure cylinder 50 leading to the accumulator cavity. High pressure plug 84, such as a Lee Plug, seals the drilling end of cross-conduit 82, being located in a counterbore thereof.
Cross-conduit 82 leads from outlet port 83 to a longitudinally oriented passage 86 which provides communication from high pressure cylinder 50 through a check valve 88 leading to an accumulator bore 90 which defines one portion of the overall accumulator cavity. Accumulator bore 90 is located generally in the peripheral region of accumulator body 26, and is oriented parallel to the longitudinal axis of accumulator body 26 Accumulator bore 90 extends downwardly to a location proximate the bottom of accumulator body 26 where it communicates with an annular cavity or ring passage seen in FIG. 1, in the same manner as accumulator bore 96 shown in FIG. 1. There are five of these longitudinally arranged accumulator bores spaced about the peripheral region of accumulator body 26 in the form of the invention illustrated in FIGS. 1-10 which cumulatively make up the primary accumulator cavity, all of which communicate with annular cavity 92. These are seen in section in FIG. 7, and in the transverse sectional view of FIG. 6 the accumulator bore 90 is seen from its upper end and the four other accumulator bores 94, 96, 98 and 100 are shown in dotted lines.
While five of these accumulator bores make up the primary accumulator cavity in the illustrated form of the invention, it is to be understood that any desired number of such accumulator bores having any desired diameter may be provided according to the selected volume for the primary accumulator cavity of injector 10. Not only can the number and diameters of these accumulator bores be varied, but also the lengths of all of these accumulator bores except inlet bore 90 can be varied to provide the desired primary accumulator cavity volume.
A feature of the present invention is the fact that the entire accumulator cavity including the primary cavity represented by accumulator bores 90, 94, 96, 98 and 100, and annular cavity 92 are completely isolated from and independent of the injector needle spring cavity, while nevertheless being compactly arranged closely proximate-the spring cavity within a lower portion of the injector, namely within accumulator body 26, and thus structurally completely separated from and independent of the upper intensifier portion of the injector. In a high pressure injector such as in the intensified injector 10, the spring cavity must be relatively large to accommodate a relatively large fast-acting needle closure spring. Separation of the accumulator cavity from the spring cavity enables the overall accumulator cavity to be much smaller than conventional accumulator cavities which include the spring cavity, for very high pressure operation of the injector 10.
As seen in FIG. 1, annular cavity or ring passage 92 communicates through a plurality of small diameter passages 102 in nozzle body 34, preferably three or four in number, to a small kidney cavity 104 in nozzle body 34 which in turn communicates with needle cavity 106 that leads to valve seat 36. The small kidney cavity 104 and needle cavity 106 together provide a small secondary accumulator cavity from which the aforesaid small pilot or initial charge is initially injected into the engine cylinder at the onset of the injection event prior to injection of the main fuel charge from the primary accumulator cavity defined in accumulator bores 90, 94, 96, 98 and 100, and annular cavity or ring passage 92. Such pilot charge is preferably about 2-20 percent of the total injected fuel charge, and most preferably about 5-10 percent of the total charge.
A cylindrical needle guide passage 108 is axially defined within nozzle body 34 between its upper end surface 32 and kidney cavity 104. Injector valve needle 110 has an upper guide position 112 which axially slideably and sealingly fits within guide passage 108. The upper guide portion 112 of needle 110 is of relatively large diameter, and below it needle 110 tapers down in the region of kidney cavity 104 to a relatively small diameter lower shank portion 114 which terminates at conical needle tip 116. The sliding fit of upper needle guide portion 112 within guide passage 108 is substantially fluid-tight and is sufficiently close to valve seat 36 for repeatably accurate centering of the needle tip 116 in valve seat 36 to provide sharper fuel cutoff and better atomization proximate the end of each injection event, as well as increased component life, relative to conventional accumulator-type injectors in which the needle was either unguided or was guided at a location axially remote from the tip.
Injector needle 110 has a flat, transverse top surface 118 at the upper end of its guide portion 112, top surface 118 being located slightly above upper end surface 32 of nozzle body 34. A small locator pin 120 extends axially upwardly from the top surface 118 of the needle to locate a spring guide and needle damper member 122 coaxially relative to needle 110. The guide/damper member 122 fits over locator pin 120 and has a flat annular damping base 124 which seats against the top surface 118 of needle 110. The damping base 124 provides damping flange means for hydraulic damping of needle closure events as described below. A reduced diameter, upwardly projecting spring locator portion 126 of guide/damper 122 provides radial centering for the needle spring. It is to be noted that the top surface 118 of needle 110, and hence also the flat annular base portion 124 of guide/damper 122, is displaced above the upper end surface 32 of nozzle body 34 in the fully closed position of needle 110, which assures complete closure of needle 110 by the needle spring.
An elongated, cylindrical spring cavity 128 extends axially upwardly from upper end surface 32 of nozzle body 34 through a major portion of the length of accumulator body 26, terminating at an upper end surface 130. The needle spring is a helical compression spring 132 which is axially arranged within spring cavity 128 with its lower end seared,against the flat annular base 124 of guide/damper 122 and its upper end seated against the upper end 130 of cavity 128.
Extending axially upwardly from the upper end 130 of spring cavity 128 through the upper end surface 24 of accumulator body 26 is a plunger guide and sealing passage 134 within which the cylindrical upper sealing portion 138 of a needle plunger 136 is slideably and sealingly fitted. Needle plunger 136 has an upper end 140 which is exposed to damper cavity 70 but recessed slightly down into passage 134 below the upper body surface 24, and hence below the bottom surface of stop plate 71, in the normally seated position of plate 71. The amount of clearance between plunger end 140 and plate 71 determines the height of the small preliminary increment of needle lift for the premix pilot charge. Plunger 136 extends axially downwardly from its upper end 140 as an integral member which includes the cylindrical upper sealing portion 138 and an elongated, cylindrical lower portion 142 which extends through the spring 132 to a lower end 144 which faces and is proximate the upward projection 126 of needle guide/damper 122. Spring cavity 128 communicates through a vent passage 146 to fuel supply conduit 76 at the interface between accumulator body 26 and intensifier body 18.
Needle plunger 136 serves a series of functions in its independent capacity from needle 110 during operation of the intensified accumulator injector 10. First, during the intensification stroke of high pressure piston 52, the intensified fluid pressure in damper cavity 70 operates through stop plate hole 74 against the upper end 140 of plunger 136 to hold plunger 136 down against guide/damper 122 so as to hold needle 110 down against needle valve seat 36 with the aid of spring 132 against the upward force of the intensified pressure in the accumulator cavity against the lower part of needle 110.
Second, the length of needle plunger 136 defines the amount of clearance between plunger end 140 and the seated stop plate 71 At the onset of the needle opening event, intensified fluid pressure acts downwardly on a larger surface of plate 71 than upwardly on plate 71 because a portion of the lower surface of plate 71 is masked by its lapped fit against upper body surface 24 and thus is subject to only fluid vapor pressure. Thus, shortly after the onset of the needle opening event, plate 71 positively stops plunger 136, and hence needle 112, at a small percentage of full needle lift, and time for injection of the pilot charge is provided until the intensified pressure above plate 71 is vented sufficiently to allow needle 112 and plunger 136 to unseat plate 71 and to move plate 71 upwardly from body surface 24.
Third, the mass of plunger 136 is added to the mass of needle 110 to damp and slow down the beginning of the needle opening event, which is an added factor in allowing time for the pilot charge in cavities 104 and 106 to be injected into the engine cylinder before it can be overtaken by the main charge from the larger primary accumulator cavity.
Fourth, with needle 110 and its plunger 136 joined as an effectively unitary structure during the opening stroke of needle 110, the upper end 140 of plunger 136 is enabled to be utilized in cooperation with plate 71 to damp the end of the needle opening event. When plate 71 is moved upwardly by plunger 136 in its damper cavity 70, displacement of fluid by plate 71 is limited by the constriction between the periphery of plate 71 and the annular wall of damper cavity 70, and by the narrowing constriction between the top of plate 71 and shoulder 73, thereby damping the upper end of the needle opening event by a hydraulic damping action which may referred to as "squish damping." This prevents needle bounce at the end of the opening event.
Fifth, and of great importance in enabling a very rapid needle closing event to be achieved,.the separation of needle plunger 136 from needle 110 enables needle 110 to be relatively short and of very low mass as compared to conventional accumulator injector needles, so that needle 110 can be accelerated very rapidly by spring 132 to achieve a very rapid needle closing event. The low mass and short length of separated needle 110 also minimize the amount of compression energy that can be stored in the needle upon impacting the seat, and correspondingly minimizes needle closing bounce. The mass of separated needle 110 may be as little as one-third or less than the mass of conventional accumulator injector needles, and the closing acceleration of the low mass, separated needle 110 is estimated to be in the range of from about 10,000-20,000 Gs.
With such a high speed needle closing event, it is desirable to damp the end of closure to assure against needle bounce, even with the short, light-weight needle, and this function is performed by guide/damper 122. As guide/damper 122 and needle 110 move downwardly during the needle closing event, fluid at rail pressure must be displaced from below guide/damper 122 through the constriction between the periphery of its flat annular base 124 or damping flange means and the wall of spring cavity 128 to above base 124. The guide/damper thus serves as a shock absorber to hydraulically damp the needle closure in a squish damping action, cushioning the end of the injection event. This is a further factor in preventing the needle from dynamically or mechanically bouncing from compression energy that might otherwise be stored along the length of the needle upon impacting the seat. This closing damper effect can be adjusted by adjusting the radial clearance between the periphery of guide/damper base 124 and the surface of spring cavity 128, or by adjusting the axial clearance between the bottom of guide/damper base 124 and upper surface 32 of nozzle body 34, or by making both adjustments.
If desired, a slight annular relief cavity (not shown) may be provided in the wall of spring cavity 128 offset above the lower end of cavity 128 so as to allow fluid to bypass the periphery of guide/damper base 124 more freely during the early part of the needle closing stroke, while still presenting the full constriction between the periphery of base 124 and the wall of spring cavity 128 during the final phase of the closure stroke. However, experiments have shown that the shock absorbing effect of the fluid constriction between the periphery of guide/damper base 124 and the unrelieved cylindrical wall of spring cavity 128 effectively eliminates secondary injections from needle bounce without detrimentally slowing down the high rate of needle closure enabled by the short, very low mass needle 110. Cooperating in such elimination of needle bounce is the very fact that the needle is short. This causes minimization of the amount of longitudinal elastic compression energy that can be stored in the needle upon impact with the seat.
Spring cavity 128, in addition to serving the functions of housing needle return spring 132 and cooperating with guide/damper 122 to damp the closure stroke of needle 110, also serves as a collector for any intensified pressure fuel which may seep between the upper sealing portion 138 of needle plunger 136 and its passage 134, or between the upper guide portion 112 of needle 110 and its guide passage 108, or from annular cavity 92 radially inwardly past the inner interface between lower accumulator body surface 30 and upper nozzle body surface 32.
Operation of the Intensified Form of the Invention
Overall and specific systems for operating an intensifier-type accumulator injector of the general type of the present invention are illustrated and described in detail in the Beck et al. U.S. Pat. No. 4,628,881, including the aforesaid high speed solenoid actuated control valve, and such systems are fully applicable for operating the intensifier-type accumulator of the present invention. Accordingly, the Beck et al. U.S. Pat. No. 4,628,881 is hereby incorporated by reference for its disclosures of apparatus and methods for operating the intensifier-type accumulator injectors 10 of the present invention.
Operation of the present invention is best understood with reference to FIGS. 1, 4, 8 and 11-13 of the drawings. FIG. 1 illustrates injector 10 in a position of repose prior to a sequence of intensification and injection events. Inlet/vent passage 64 is vented to a sufficiently reduced pressure, which may be essentially atmospheric pressure, to enable spring 62 to bias low pressure piston 48 and high pressure piston 52 to their uppermost positions, with the lower end 56 of high pressure piston 52 above fuel inlet cross-conduit 78. Fuel supply conduit 76 is constantly supplied with fuel at rail pressure, and high pressure cylinder 50 below piston 52 has been filled with fuel at rail pressure from fuel supply conduit 76 through inlet conduit 78 and fuel port 79. Injector needle 110 is closed against needle valve seat 36, and accumulator inlet check valve 88 is also closed, with the fuel pressure within the accumulator cavity static at the needle closure pressure, which is preferably relatively high for a crisp needle closing event with good fuel atomization right up to closure and minimal, if any, fuel dribble proximate closure. Typically, this static, residual pressure within the accumulator cavity will be in the range of from about 3,000 psig to about 6,000 psig, and preferably it will be in the high pressure part of this range for best fuel cutoff characteristics. Needle stop plate 71 is biased by spring 72 to its sealed position against the upper surface 24 of accumulator body 26. Needle plunger 136 may, in this rest condition of injector 10, be in any position from where its lower end 144 is in contact with guide/damper 122 to where its upper end 140 is in contact with stop plate 71.
An intensification stroke is caused by introduction of fuel at rail pressure through actuating fluid inlet passage 64 into low pressure cylinder 46 to drive low pressure piston 48 downwardly, piston 48 carrying high pressure piston 52 downwardly with it for the intensifying stroke, the extent of this stroke being determined either by the time duration of application of rail pressure through passage 64 for time metering or by the pressure of the fuel introduced through passage 64 for pressure metering. The maximum travel of this intensification stroke is to the position of high pressure piston 52 shown in FIG. 4, with the upper end of reduced portion 57 still being located above the high pressure cylinder outlet port 83 so that port 83 remains clear. During this downward intensification stroke of the pistons, fuel is pressurized and compressed within high pressure cylinder 50, and such pressurization and compression is transmitted into the entire accumulator cavity through high pressure cylinder outlet port 83, cross-conduit 82, longitudinal passage 86, check valve 88, and accumulator bore 90, the pressurized, compressed fuel passing from bore 90 into annular cavity 92 and thence into accumulator bores 94, 96, 98 and 100, and also downwardly through nozzle passages 102 into kidney cavity 104 and needle cavity 106. The quantity of fuel thus poised in the accumulator cavity for injection depends upon the amount of compression of the fuel within the accumulator cavity, which depends upon the amount of pressure provided by the intensifier stroke, and this may range from about 6,000-7,000 psig for minimum engine power at idle up to about 22,000 psig or even higher for maximum engine power.
During the intensification stroke, the increasingly high intensified pressure within high pressure cylinder 50 is applied through damper cavity 70 to the upper end surface 140 of needle plunger 136. Plunger 136 seats against guide/damper 122 and transmits the resulting force of the intensified pressure to guide/damper 122 and thence to top surface 118 of needle 110, and this force, together with the force of needle spring 132, securely holds needle 110 down on its seat 36. This downward force on needle 110 is greater than the upward force as determined by the intensified pressure within kidney cavity 104 and needle cavity 106 operating upwardly on the differential area between the cross-section of upper guide portion 112 of the needle and the area of the needle seat.
At the end of the intensification stroke, injector 10 is ready for an injection event, which is initiated by venting the actuating fluid inlet/vent passage 64, and hence low pressure cylinder 46, to a reduced pressure. This allows piston spring 62 to move both of the pistons 48 and 52 upwardly at a rate which may be controlled by orificing of passage 64, which now serves as a vent conduit. The mode of operation of the two-stage needle lift is best understood with reference to the graph or chart in FIG. 11.
The solid line curve 149 in FIG. 11 represents a plot of intensifier pressure (the pressure within intensifier cylinder 50) versus time. This curve shows the rate of decay of pressure in intensifier cylinder 50 as it may be controlled by orificing of vent passage 64. Adjustment of the orificing of vent passage 64 will cause a corresponding adjustment of the rate of decay or slope of the pressure/time curve. Thus, a greater constriction of the orificing in passage 64, with a reduced vent flow rate, will result in a flatter pressure/time curve; while a lesser constriction in passage 64, with corresponding increased vent fluid flow through passage 64, will result in a steeper slope for pressure/time curve.
The dotted line curve represents needle position versus time, and shows how the needle lift timing relates to the intensifier pressure decay curve.
At time T 0 the injection event is set into motion by commencement of venting of low pressure cylinder 46 through vent passage 64. At this time the needle is closed, or has zero lift. As the pressure decays from T 0 to T 1 , the needle remains closed because
A.sub.pl (P.sub.int)>P.sub.acc (A.sub.stem -A.sub.seat)-F.sub.s
where
A pl is the cross-sectional area of upper portion 138 of plunger 136
P int is pressure in intensifier cylinder 50
P acc is pressure in the accumulator cavity
A stem is the area of the upper guide portion 112 of needle 110
A seat is the area of the needle valve seat
F s is the force of needle spring 132.
The needle lifts initially to its prelift increment at time T 1 when A pl (P int )=P acc (A stem -A seat )-F s . This initial prelift increment is preferably in the range of from about 1-20 percent of maximum needle lift. It is shown on the needle lift curve as being approximately 5 micrometers, or 0.005 millimeters. This low-lift or prelift increment of the needle lift is defined when the upper end 140 of plunger 136 is stopped against the bottom surface of stop plate 71 which is seated and sealed against upper surface 24 of accumulator body 26. The upward blip of the pressure/time curve at T 1 represents a momentary pressure surge in intensifier cylinder 50 caused by the.upward shift of plunger 136. Between T 1 and T 2 , stop plate 71 remains seated against body surface 24 to hold the needle at the fixed prelift increment because
A.sub.p2 (P.sub.int)+F.sub.sl >P.sub.acc (A.sub.stem -A.sub.seat)-F.sub.s
where
A p2 is the cross-sectional area of stop plate 71 which is sealed against upper body surface 24
F sl is the force of plate spring 72.
The needle lifts completely starting at time T 2 when
A.sub.p2 (P.sub.int)+F.sub.sl =P.sub.acc (A.sub.stem -A.sub.seat)-F.sub.s
In the example of FIG. 11, full needle lift is approximately 0.2 millimeters. At time T 2 , stop plate 71 becomes unseated from upper body surface 24 so that the seal between the plate 71 and the shoulder 24 is broken and the vapor pressure acting on the bottom of plate 71 increases to the ambient pressure in cavity 70. Plate 71 thus shifts upwardly to become seated on stop shoulder 73. The pressure blip proximate T 2 is caused by a transitory pressure surge in intensifier cylinder 50 when plunger 136 and stop plate 71 shift upwardly.
The volume of the pilot charge will vary generally proportionally to both the time duration between T 1 and T 2 and the height of the needle prelift increment, both indicated by the dotted line curve. It is preferably about 2-20 percent of the total fuel charge, and most preferably about 5-10 percent of the total charge.
In FIG. 12, needle 110 is shown in its fully open position, with needle 110, guide/damper 122, plunger 136 and stop plate 71 all closed together in a solid column, and stop plate 71 seated against shoulder 73. .
The two phases of needle opening movement proximate T 1 and T 2 are slowed down and controlled by addition of the mass of plunger 136 to the mass of needle 110. The very short distance needle 110 and plunger 136 travel during the prelift phase does not allow enough momentum to build up in the needle/plunger combination to jar plate 71 off of its seated, sealed position. Then, when needle 110, plunger 136 and plate 71 move on upwardly in the second opening phase for the main injection, plate 71 damps the end of the opening event by hydraulic squish damping. This is caused both by the closely constricted peripheral zone between the outer annular surface of plate 71 which restricts fluid flow from above to below plate 71, and by the narrowing gap as the upper surface of plate 71 approaches its mating shoulder 73. The result is substantial elimination of needle bounce at the end of the opening event, with better spray uniformity at the beginning of the main part of the injection.
The needle remains open during the second phase or main part of the injection event as long as
P.sub.acc (A.sub.stem -A.sub.seat)>F.sub.s
Then the needle closing event commences when
P.sub.acc (A.sub.stem -A.sub.seat)=F.sub.s
Needle closure then occurs rapidly until complete closure occurs at time T 3 . Separation of needle 110 from plunger 136 during needle closure greatly reduces the effective mass and hence the inertia of the needle so that needle 110 can be accelerated very rapidly by spring 132 to achieve a rapid, crisp closing event; while at the same time, the low mass and short length of the separated needle 110 minimize needle bounce by minimizing the amount of compression energy that can be stored in the needle upon closing impact with the seat.
FIG. 13 illustrates the separation of needle 110 and its guide/damper 122 from needle plunger 136 during the closing event. Since needle 110 and guide/damper 122 are completely separate parts from needle plunger 136, they are enabled to be driven entirely independently of plunger 136 from the open position of FIG. 12 through the closing event to the closed position of FIG. 13.
Needle bounce is also minimized by the squish damping effect resulting from the small clearance between the flanged periphery of guide/damper 124 and the cylindrical surface of spring cavity 128, and also by the limited clearance between the bottom of guide/damper 124 and the upper surface 32 of nozzle body 34. The very light-weight, short needle 110 cooperates in such squish damping by minimizing the amount of needle inertia which must be controlled by the damping. With these factors cooperating, needle bounce is substantially eliminated in the present invention. With relatively high closing accumulator pressure, the rapid, crisp closing event, coupled with the substantial elimination of closing needle bounce, enable full fuel atomization to be maintained right up to needle closure, for optimum ignition. The sharp closure cutoff and elimination of fuel dribble at closure are important in the elimination of smoke and hydrocarbon emissions.
It is to be noted that the needle closure damper, represented by the guide/damper and its small clearances relative to the surface of spring cavuty 128 and surface 32 of nozzle nody 34, is remote from needle tip 116 and valve seat 36. This permits efficient-shaping of the needle tip and valve seat for a high flow coefficient as the needle approaches the seat during closure. Such high flow coefficient enables high pressure to be maintained proximate the seat for good atomization up to closure.
Another factor which assures sharp fuel cutoff at needle closure is the close proximity of needle guide portion 112 in guide passage 108 to the needle seat 36. By this means, the needle is continuously guided for consistent concentric seat contact. This is a factor in making the end of the injection event stronger than for conventional accumulator injector needles, with resulting better atomization at the end of injection. Consistent concentric closure contact of the needle in the seat assures a high flow coefficient and consequent high closing pressure and good atomization.
Referring again to FIG. 11, although the invention is not limited to any particular time intervals, typically the time from T 0 to T 1 will be on the order of about 0.1-0.3 milliseconds, and the time from T 2 to T 3 will be on the order of about 4-8 milliseconds. By way of comparison, with a conventional accumulator-type injector, the needle will be fully opened in on the order of about 0.2 milliseconds.
As-an alternative to, or in addition to, controlling the rate of decay of the intensifier pressure as represented by curve 149 in FIG. 11 by means of orificing of vent passage 64 to slow down the vent rate from low pressure cylinder 46, the vent rate from low pressure cylinder 46 can also be controlled by adjusting the pressure level in the vent line. Thus, by raising the vent pressure in passage 64, the differential pressure between low pressure cylinder 46 and vent passage 64 will be lowered, correspondingly lowering the rate of fluid venting from low pressure cylinder 46, and accordingly flattening the intensifier pressure/time curve 149 in FIG. 11. Conversely, lowering of the vent pressure level in vent passage 64 will increase the pressure differential between low pressure cylinder 46 and vent passage 64, steepening the intensifier pressure/time curve 149 in FIG. 11. Such adjustments will, therefore, vary the time intervals between T 0 and T 1 and between T 1 and T 2 .
The two-stage opening of the needle in the present invention to provide a small initial pilot charge followed by the main charge has important benefits. The small amount of fuel in the pilot charge will ignite before the needle opens fully, so that the fire has started when the main charge is injected. This causes the main charge to ignite immediately upon injection, without the usual large percentage of the main charge being injected before it ignites. This provides a great reduction in noise, improvement of fuel economy, and elimination of smoke. It also greatly reduces undesirable exhaust emissions, principally oxides of nitrogen and hydrocarbon emissions.
In the foregoing description of the intensified form 10 of the invention, full needle lift has been indicated as being determined by engagement of stop plate 71 against stop shoulder 73. This will always be true for high power engine settings. However, the amount of needle lift off of its seat will actually vary generally in proportion to the difference between the opening and closing pressures of the accumulator as discussed in detail hereinafter in connection with the unintensified form of the invention shown in FIGS. 14-17. Accordingly, it is to be understood that for low and intermediate engine power settings, typically the needle will not lift off of the seat during the second, main phase of the injection sufficiently for stop plate 71 to fully seat against shoulder 73.
FIG. 9 illustrates a modified stop plate 71a which defines the prelift increment by the depth of a downwardly facing annular, axial recess 147 in plate 71a. Here, in the lowermost position of plunger 136a which is shown, its top surface 140a registers with the upper surface 24 of accumulator-body 26. This modification enables stop plate 71a to be thicker than stop plate 71 of FIGS. 1, 4 and 8, thereby minimizing the possibility of flexure of plate 71a when it is impacted by plunger 136a, so as to assure maintenance of the seal between the bottom surface of plate 71a and the upper body surface 24. Damper cavity 70a in intensifier body 18a is made correspondingly deeper to accommodate the thicker plate 71a.
FIG. 10 illustrates a further modified stop plate arrangement which would eliminate any possibility of the prelift seal between the stop plate and the body being disrupted by the impact of the plunger against the plate. In this case, two annular seals are employed in place of the flat seal of each of the stop plates 71 and 71a against the respective bodies. In the form of FIG. 10, plate 71b is made still thicker to accommodate a deeper annular, axial recess 147b in the bottom of plate 71b, and the upper end of plunger 136b extends up into recess 147b in the lowermost position of plunger 136b which is shown. The prelift increment of movement is defined by the spacing between upper end surface 140b of plunger 136b and the end of plate recess 147b. A first lapped seal is provided between the cylindrical outer periphery of plate 71b and the cylindrical surface of damper cavity 70b, and a second lapped seal is provided between the cylindrical surface of plunger 136b and the opposed cylindrical surface of plate recess 147b. These two annular seals serve the same sealing function as the single flat seal in the other two forms, but they cannot be disrupted by impacting of plunger 136b against plate 71b. Damper cavity 70b is given still further depth to accommodate the thicker stop plate 71b.
In the embodiment of FIG. 10, hydraulic damping of full-lift needle opening events is caused by the constriction between the top surface of plate 71b and shoulder 73b as plate 71b approaches shoulder 73b.
Unintensified Form of the Invention
An unintensified form of the invention is illustrated in FIGS. 14-17 of the drawings. The unintensified accumulator injector of the invention has particular utility for gasoline engines, for which the injection pressures will typically be considerably less than for diesel engines. Nevertheless, it is to be understood that the unintensified form of the invention shown in FIGS. 14-17 may be beneficially employed with both diesel and gasoline engines, or with engines powered by other liquid fuels. In the unintensified form of the invention, the pressure of the fuel in the accumulator immediately preceding the injection event is substantially rail pressure, and this can be adjusted to accommodate the requirements of any type engine.
The unintensified accumulator injector shown in FIGS. 14-17 is generally designated 152, and has an elongated body 153 with a relatively large diameter upper portion 154 and a relatively small diameter lower portion 156. The lower body portion 156 forms an inner core structure within the accumulator cavity, and defines the needle spring cavity separately from the accumulator cavity. Body 152 has a flat, transverse lower end surface 158 which is lapped to the complementary flat, transverse upper surface 160 of nozzle body 162. Nozzle body 162 carries a pintle-type nozzle generally designated 164, the structure and operation of which will be described in detail hereinafter in connection with FIGS. 15-17.
Elongated body 153 and nozzle body 162 are both carried in a housing generally designated 166. Housing 166 has an internally threaded upper coupling section 168 within which the upper body portion 154 is threadedly coupled, with an O-ring seal 170 engaged between body portion 154 and housing 166 to provide a fluid-tight seal for the accumulator cavity within housing 166. Housing 166 has an intermediate barrel section 172, and a reduced diameter lower end section 174 which provides a seat for nozzle body 162, with a seal ring 175 providing a fluid-tight seal between nozzle body 162 and the inwardly flanged lower end of housing 166.
Fuel is supplied to injector 152 from a high speed solenoid actuated valve (not shown) at common rail (regulated pump) pressure through a fuel supply conduit 176 in body 152 for pressurizing the accumulator cavity. The rail pressure fuel passes from supply conduit 176 through a short communicating transverse conduit 178, past a check valve 180, and thence through a generally longitudinally arranged conduit 182 into the primary accumulator cavity which-includes an upper portion 184 defined between the inner surface 186 of housing barrel section 172 and the stepped outer surfaces 188 and 190 of lower body portion 156; and a lower portion 192 defined between a reduced diameter inner housing surface 194 and both the elongated body surface 190 and the outer surface 196 of nozzle body 162. A plurality of passages 198, preferably three or four in number, extends downwardly and radially inwardly from lower accumulator cavity section 192 to kidney cavity 200 which surrounds the lower end portion of the valve needle and communicates with the valve seat 202 through a cavity extension 203. Kidney cavity 200 and its extension 203 together form a small secondary accumulator cavity for providing a small initial injection charge before the primary injection charge comes from the main accumulator cavity consisting of respective upper and lower primary cavity sections 184 and 192.
The injector needle is generally designated 204, and includes a cylindrical upper guide portion 206, the needle tapering down to a relatively smaller diameter lower shank portion 208 leading to the needle tip. Upper guide portion 206 of needle 204 is axially slideably and sealingly mounted in a needle guide passage 209 which extends from kidney cavity 200 axially through nozzle body 162.
Injector needle 204 has a flat, transverse top surface 210 located slightly above upper end surface 160 of the nozzle body 162 in the closed position of needle 204 as shown in FIG. 14. A needle damper and lower spring guide 212 seats flush against the top surface 210 of the needle. Damper/guide 212 has a flat annular damping base or flange 214 and an axially upwardly projecting spring locator portion 216 of reduced diameter. Damper/guide member 212 is located in the lower end portion of an elongated, cylindrical spring cavity 218 which is axially disposed within the lower portion 156 of central body 152. Spring cavity 218 extends from a lower end defined by the upper surface 160 of nozzle body 162 axially upwardly to an upper end 220 against which an elongated, tubular upper spring guide 222 seats. Needle spring 224, which is a helical compression spring, is engaged between damper/guide 212 and guide 222. A downward extension 226 of fuel supply conduit 176 communicates through tubular upper guide 222 to spring cavity 218 so as to apply fuel at rail pressure within spring cavity 218 when the accumulator cavity is pressurized. Spring cavity 218 is solidly filled with fuel at all times during operation of injector 150, pressurized fuel within cavity 218 operating downwardly against the needle top surface 210 together with the force of spring 224 holding needle 204 down when the accumulator cavity is pressurized, and the presence of fuel in cavity 218 enabling damper/guide 212 to perform its hydraulic needle damping function at the end of each injection event.
As with the intensified form of the invention, an advantage of the unintensified form shown in FIGS. 14-17 is the fact that the entire accumulator cavity is completely isolated from and independent of the injector needle spring cavity, while nevertheless being arranged closely proximate the spring cavity within a lower portion of the injector, and being concentrically and thereby compactly oriented about the spring cavity. This enables the spring cavity to be made relatively large to accommodate a relatively large, fast-acting needle closure spring, while at the same time placing no limit on how small the accumulator cavity may be made for high pressure operation of the injector 152.
As with the intensified form, the unintensified form of FIGS. 14-17 has the advantages of a short, light-weight needle and remote location of the needle closure damper relative to the needle and its seat, with the same advantages as set forth hereinabove for the intensified form. FIGS. 15, 16 and 17 illustrate the structure and operation of pintle nozzle 164, FIG. 15 showing nozzle 164 in its fully closed position, FIG. 16 showing nozzle 164 in a partially opened position, and FIG. 17 showing nozzle 164 in its fully opened position. Pintle nozzle 164 has a cylindrical orifice 228 which extends axially from frustoconical valve seat 202 downwardly through the lower end 230 of injector 150, which is the flat lower end surface of nozzle body 162. A reduced diameter pintle shank 232 extends axially downwardly from the lower end 234 of needle 204 which is located just below the frustoconical needle seating surface 236. A flared pintle head 238 on the lower end of pintle shank 232 has a frustoconical downwardly and radially outwardly deflecting spray surface or flare portion 240, pintel head 238 ending in a lower cylindrical tip portion 242 which has a flat, transverse end surface 244. Pintle nozzle 164 produces a generally conical injection spray, the cone angle of which varies generally in inverse proportion to the volume of fuel injected into an engine cylinder during each injection event, the cone angle varying from a relatively widespread cone angle at minimum or idle engine power down to a relatively narrow cone angle at high or maximum engine power.
Operation of the Unintensified Form of the Invention
The overall and specific systems shown and described in the Beck et al. U.S. Pat. No. 4,628,881 for operating an unintensified accumulator injector, such as that in FIGS. 16-18 of that patent, including the aforesaid high speed solenoid actuated control valve, are fully applicable for operating the unintensified accumulator injector of the present invention. Accordingly, the Beck et al. U.S. Pat. No. 4,628,881 is hereby incorporated by reference for its disclosures of apparatus and methods for operating the unintensified accumulator injectors 152 of the present invention.
As with the intensified form of the invention, an overall system for operating an unintensified-type accumulator injector of the general type of the present invention is illustrated and described in detail in the Beck et al. U.S. Pat. No. 4,628,881, and everything disclosed in that patent relative to systems for operating unintensified injectors and modes of operation of unintensified injectors is applicable for operation of the unintensified-type accumulator injectors 152 of the present invention. Accordingly, the Beck et al. U.S. Pat. No. 4,628,881 is hereby incorporated by reference for its disclosures of apparatus and methods for operating the unintensified-type accumulator injectors 152 of the present invention. The unintensified version of the invention disclosed in the Beck et al. '881 patent is illustrated in FIGS. 16-18 of that patent and described in detail in connecting therewith.
Fuel at rail pressure is valved to fuel supply conduit 176, preferably by actuation of a high speed solenoid actuated valve which may be like the valve 30 shown and described in detail in the Beck et al. '881 patent, which is best illustrated in FIGS. 5a, 9 and 10 of that patent, and is illustrated in connection with the unintensified form of injector in FIGS. 16-18 of that patent. As with the intensified form of the present invention, it is desirable to incorporate in the unintensified form of the present invention features which are covered in the previously referred to co-pending applications Ser. Nos. 823,807 and 830,000.
The incremental volume of fuel injected during each injection event of injector 152 will be determined by the pressure of the fuel that is built up in the accumulator cavity by fuel introduced through fuel supply conduit 176. Such accumulator pressure may be determined by time interval or pulse width fuel metering from a source with a fixed rail pressure, or by pressure compressability metering from a variable rail pressure source, or a combination of both types of fuel metering. The injection pressure may be varied according to the needs of any engine, typically from about 500 psig to about 2,000 psig for direct injection gasoline engines, and typically from about 500 psig to about 22,000 psig for diesel engines.
During the accumulator cavity pressurizing phase of the injector operating cycle, pressurized fuel entering fuel supply conduit 176 will be introduced into the accumulator cavity through transverse conduit 178, check valve 180, and conduit 182 until the pressure required for any particular power setting of the engine is achieved in the accumulator cavity. Before the actual injection event occurs, the pressure will be substantially uniform in all portions of the accumulator cavity, including the primary accumulator cavity consisting principally of upper portion 184 and lower portion 192, and also including the small volume within entry conduit 182 and the small volume within nozzle passages 198, and the secondary accumulator cavity consisting of kidney cavity 200 and its extension 203. For time interval or pulse width fuel metering, the pressure in the accumulator cavity will be raised to substantially the fixed rail pressure for maximum power, and will be proportionately less for lower power settings. For pressure compressibility metering, the pressure will be raised in the accumulator cavity to substantially the rail pressure which will vary from a maximum pressure for a full power setting of the engine and a proportionately lesser pressure for lower power settings of the engine.
When the programmed pressure for an injection event has been achieved within the accumulator cavity, either at the end of the pressure input pulse through supply conduit 176 for time interval or pulse width metering, or upon substantially reaching a fluid pressure balance of the pressure in supply conduit 176 and the pressure in the accumulator cavity for pressure compressibility metering, check valve 180 will close to seal off the accumulator cavity from supply conduit 176. During pressurization of the accumulator cavity and after such pressurization but before commencement of the injection event, injector needle 204 will be positively held down against valve seat 202 by the combined forces of compression spring 224 and fluid pressure applied from within spring cavity 218 against the top surface 210 of needle 204. These combined downward forces on needle 204 overpower the upward force on needle 204 which is the force of fluid pressure in the accumulator cavity operating upwardly against the differential area of the cross-section of-upper needle portion 206 minus the seating area of the needle seating surface 236 against valve seat 202.
After the accumulator cavity has been pressurized to the programmed extent, the injection event is initiated by movement of the control valve to a vent position which relieves the pressure from supply conduit 176. This relieves the fluid pressure from within spring cavity 218, and hence from top surface 210 of needle 204 through tubular upper spring guide 222 and supply conduit extension 226, and the fluid pressure in the accumulator cavity operating upwardly on the aforesaid differential cross-sectional area of the needle overcomes the force of spring 224 and lifts needle 204 up off of valve seat 202 to commence the injection event. The injection will continue, with needle seating surface 236 separated from seat 202, until the accumulator pressure drops to a level at which spring 224 overcomes the upward force of the reduced accumulator pressure on the aforesaid needle differential area, at which time the needle surface 236 will again seat on valve seat 202 to complete the injection event.
The incremental volume of fuel injected during the injection event will be approximately proportional to the difference between the opening and closing pressures within the accumulator cavity, the closing pressure being determined by the axial compression force of the needle spring 224 that is selected. Thus, the volume of fuel injected is based upon the compressibility of the fuel within the accumulator cavity. The needle closing force of spring 224 is preferably selected to maintain a relatively high accumulator cavity pressure at the end of injection so as to provide a crisp closing event without any material fuel dribble, and with the injected fuel still being properly atomized at the end of injection. Such closing pressure may be on the order of about 3,000-4,000 psig.
Although not shown, if desired, the unintensified form of the invention may be arranged to have a two-part needle with a needle plunger like plunger 136 of the intensified form, for slowing down the opening movement of the needle, while nevertheless enabling the needle to be short and light-weight for fast closure with minimum possible closure bounce. Also, if desired, although not shown, the unintensified form of the invention may embody a damper cavity like cavity 70 of the intensified form in the fuel supply (and vent) conduit extension 26, with an opening stop plate or wafer like stop plate 71 of the intensified form biased against a lapped seat, for providing a two-step opening event as in the intensified form. In such case, the upper spring guide 222 would be omitted.
Needle closure damping is effected in the same way in the unintensified form of the invention shown in FIGS. 14-17 as in the intensified form shown in FIGS. 1-13, damper/guide 212 in the unintensified form operating in the same manner as damper/guide 122 in the intensified form. Thus, during the closing event, fuel must be displaced from below annular base 214 of guide/damper 212 between the flanged periphery of base 214 and the wall of spring cavity 218 to above the base 214. This provides hydraulic squish damping of needle 204, preventing needle bounce and consequent fuel dribble often associated with high speed needle closure. Needle 204 of unintensified injector 150 is very short, and consequently may be very light in weight so as to cooperate in such squish damping by minimizing the amount of needle inertia which must be controlled. The needle closure damping effect can be adjusted by adjusting the radial clearance around and under damper/guide 212.
A unique operational feature of an accumulator-type injector is that the amount of lift of the needle off of its valve seat varies generally in proportion to the difference between the accumulator opening and closing pressures. Since the incremental volume of fuel injected during an injection event is also generally proportional to the difference between the opening and closing pressures, the amount of needle lift during an injection event will be generally proportional to the incremental fuel volume delivered during the injection event. Advantage is taken of this characteristic of the accumulator injector in the form of the invention shown in FIGS. 14-17 to tailor the spray configuration variably according to the power demands of the engine so as to optimize combustion at varying power settings. This is accomplished with the pintle-type nozzle 164 in injector 152. The manner in which pintle nozzle 164 thus tailors the spray is illustrated in FIGS. 15, 16 and 17.
At relatively low fuel delivery, as for example during engine idle, best combustion is achieved with a relatively wide, flat conical spray configuration. At higher and higher power settings, it is desirable to have the cone of the spray become narrower and narrower, and a relatively narrow spray cone is most efficient for a full power setting to get the spray through the whole cylinder combustion cavity.
FIG. 15 illustrates needle 204 in its fully closed position, with its seating surface 236 fully seated against valve seat 202. In this position of needle 204, the flared pintle head 238 is substantially entirely outside of the cylindrical valve output orifice 228. As the needle lifts slightly above seat 202 in a minimum power setting of the engine, pintle head 238 is still mostly outside of orifice 228, enabling the frustoconical deflecting surface 240 of pintle head 238 to deflect the injected fuel at a maximum cone angle of relatively flat configuration.
FIG. 16 shows needle 204 at an intermediate fuel delivery position for intermediate engine power, the needle being shown in FIG. 12 approximately half-way between its fully closed and fully opened positions. In the intermediate needle position of FIG. 12, pintle head deflecting surface 240 is substantially completely within cylindrical orifice 228, but it is still in a position to cause a considerable amount of deflection of the fuel into a substantial cone angle of the injected spray.
In the fully opened position of the needle illustrated in FIG. 17, the cylindrical tip portion 242 of pintle head 238 has moved part-way into cylindrical orifice 228 to provide a narrow cylindrical fuel ejection annulus which greatly reduces the deflecting effect of the frustoconical surface 240 to produce a relatively narrow conical fuel spray configuration which optimizes combustion at high fuel delivery for high engine power.
Selection of the deflecting surface 240 of pintle head 238 to be substantially frustoconical assures that the spray configuration will be generally conical.
While the straight cylindrical orifice 228 and pintle head 238 with a frustoconical deflecting surface 240 and a straight cylindrical tip portion 242 provide good tailoring of the spray configuration to match varying fuel deliveries, it is to be understood that the contours of orifice 228 and pintle head 238 may be varied as desired to meet particular engine requirements within the scope of the invention. It is also to be understood that a pintle-type nozzle such as nozzle 164 shown in FIGS. 14-17 may optionally be employed in an intensified form of the present invention such as that shown in FIGS. 1-13.
The hydraulic damping of needle closure events provided by damping flange 214 within spring cavity 218 cooperates with the spray tailoring of pintle nozzle 164 to preserve the tailored configuration of the spray right up to needle closure, without altered spray characteristics as would be otherwise caused by needle bounce. By having the damper in the spring cavity and thus remote from the needle tip, the damper cannot alter the flow characteristics of the pintle nozzle.
FIGS. 18, 19 and 20 diagrammatically illustrate another two-stage needle lift control system, generally designated 250 which is shown applied to an intensified accumulator injector. The needle lift control system 250 is in t-he form of a hydraulic circuit which produces two-stage venting from low pressure cylinder 252 above low pressure intensifier piston 254 through inlet/vent passage 256. This, in turn, produces a two-stage upward movement of high pressure intensifier piston 258 and consequent two-stage pressure relief in high pressure intensifier cylinder 260 causing a first, low-lift increment of movement of injector needle 262, and then in sequence the full lift movement of needle 262. Needle 262 is illustrated diagrammatically in FIG. 18 as a unitary needle structure axially slideable in guide bore 263. It is to be understood, however, that a divided needle may be employed as in the form of the invention illustrated in FIGS. 1-13. The intensified form of the invention employed in conjunction with the two-stage hydraulic lift control system 250 of FIGS. 18, 19 and 20 may be structurally and functionally like the intensified injector system of FIGS. 1-13, although it does not employ a needle stop and damping plate like plate 71 to produce the two-stage needle lift control.
FIG. 18 illustrates the needle lift control system 250 in an actuated condition for producing the intensification stroke, with rail pressure applied through inlet/vent passage 256 to low pressure cylinder 252, with both low pressure piston 254 and high pressure piston 258 at their lowermost positions and needle 262 closed. FIG. 19 illustrates the hydraulic circuit 250 in an unactuated, preliminary slow vent condition in which fluid pressure is slowly vented out of low pressure cylinder 254 through inlet/vent passage 256, with respective low and high pressure pistons 252 and 258 slightly raised to partially relieve pressure in high pressure cylinder 260 and thereby allow a preliminary low-lift increment of needle movement. FIG. 20 illustrates the hydraulic circuit 250 in an unactuated full vent condition in which fluid pressure is fully vented from low pressure cylinder 254 through inlet/vent passage 256, allowing full upward movement of the respective low and high pressure pistons 252 and 258, reducing the fluid pressure in high pressure intensification cylinder 260 sufficiently for full needle lift.
Referring to FIG. 18, the needle control system 250 has as its primary basis a tandem valve arrangement consisting of a high speed solenoid valve generally designated 264 and a control valve generally designated 266 which is actuated in response to actuation of solenoid valve 264. Solenoid valve 264 has a valve chamber 268 inside the body of the valve, with a valve seat cartridge 270 in chamber 268. A supply ball poppet 272 is located in supply chamber 274 defined in one end of the valve chamber 268, supply chamber 274 receiving fuel at rail pressure through a supply passage 276. A vent ball poppet 278 is located in vent chamber 280 defined in the other end of valve chamber 268, and is in communication with a vent passage 282 which communicates to a vent pressure which may be somewhat above atmospheric pressure, as for example about 30 psig, or may if desired be atmospheric pressure.
Valve seat cartridge 270 has an axial passage 284 therethrough which communicates with the seats for both balls 272 and 278. A ball separator pin 286 extends through passage 284 and holds balls 272 and 278 spaced apart greater than the spacing between the two valve seats, so that when either ball is seated it causes the other ball to become unseated. A control conduit 288 communicates with the cartridge passage 284, and hence with both of the valve seats. Solenoid 290 is axially aligned with balls 272 and 278 and the ball seats, and has an armature pin 292 which, in the energized condition of solenoid 290 illustrated in FIG. 18, closes vent ball 278 against its seat, which causes supply ball 272 to be unseated. In the deenergized condition of solenoid 290 as illustrated in both of FIGS. 19 and 20, vent ball 278 is released, enabling rail pressure fuel in supply chamber 274 to close supply ball 272 against it seat, which in turn causes vent ball 278 to be lifted off of its seat.
Control valve 266 has a cylinder 294 in its valve body, with a control piston 296 slideable in cylinder 294. A fuel supply conduit 298 communicates from solenoid valve control conduit 288 through a check valve 300 to cylinder 294 at the rear of piston 296. A variable bleed orifice 302 provides outlet communication from cylinder 294 behind piston 296 through an increment vent conduit 304 to the solenoid valve control conduit 288. Bleed orifice 302 may have manual adjustment means such as an adjustment needle 306 for adjusting the rate of bleed through orifice 302, or may have automatic adjustment means controlled according to the condition of engine operation. Bleed orifice 302 is adapted to allow pressurized liquid to slowly bleed from cylinder 294 behind piston 296 so as to allow slow retraction of piston 296.
A primary vent conduit 308 communicates with cylinder 294 but is completely blocked by piston 296 in the fully advanced, actuated position of piston 296 as seen in FIG. 18. Piston 296 has an annular relief or reduction 310 proximate the head of the piston, which is offset from the primary vent conduit 308 in the fully advanced position of piston 296 as shown in FIG. 18, but which shifts into registry with vent conduit 308 when piston 296 shifts to a retracted position as shown in FIG. 20. Piston head relief 310 may, if desired, be in the form of an annular array of axially directed bleed grooves. Inlet/vent passage 256 for low pressure intensifier cylinder 254 communicates with cylinder 294 forward of the head of piston 296 in all positions of piston 296, and is placed in fluid communication with primary vent conduit 308 when piston 296 retracts to a full vent position like that illustrated in FIG. 20.
A poppet valve is carried in the body of control valve 266 in axial alignment with cylinder 294 and piston 296, spaced forward of the head of piston 296. This poppet valve includes an annular valve seat member 312 and a ball poppet 314 carried in a high pressure ball chamber 316. Chamber 316 is provided with liquid fuel at rail pressure from supply passage 276 through a supply conduit 318. Ball 314 is normally held in a closed, seated position as shown in FIGS. 19 and 20 by rail pressure of fuel in ball chamber 316. A ball actuator pin 320 extending from the head of piston 296 is adapted to unseat ball 314 in the fully actuated, advanced position of piston 296 as shown in FIG. 18 to supply fuel at rail pressure through seat member 312, cylinder 294 and inlet/vent passage 256 to low pressure intensifier cylinder 252 to provide the intensification stroke.
In operation, the two-stage needle lift control system 250 of FIGS. 18-20 first produces an intensification stroke during which the accumulator is charged with fuel under intensified pressure, and the high fluid pressure in the high pressure intensification cylinder holds the needle down. Then, at the engine-programmed time for injection, the prelift or low-lift needle movement is caused to occur for injection of a pilot charge, and then in sequence full needle lift is effected for the main fuel charge.
This operational sequence of the control system 250 starts with the system in its fully relaxed condition illustrated in FIG. 20. In the condition of FIG. 20, solenoid 290 is unenergized, its armature pin 292 retracted to the right, supply ball 272 seated under the influence of fuel at rail pressure, and vent ball 278 unseated. Fuel pressure has been vented from cylinder 294 of control valve 266 through bleed orifice 302, increment vent conduit 304, control conduit 288, axial passage 284 of seat cartridge 270, and out past vent ball 278, its vent chamber 280 and vent passage 282. Such venting has caused control valve piston 296 to shift to the right to its full vent position in which pressurized fluid has been vented from low pressure intensifier cylinder 254 through inlet/vent passage 256, cylinder 296 and primary vent conduit 308, thus causing respective low and high pressure intensifier pistons 252 and 258 to be in their fully retracted or full lift positions, with injector needle 262 closed. Ball 314 of control valve 266 is seated, blocking rail pressure fuel from entering low pressure intensifier cylinder 254.
Energization of solenoid 290 shifts the control system 250 to its condition illustrated in FIG. 18. When solenoid 290 is energized, its armature pin 292 is extended, to the left as illustrated, seating vent ball 278 and unseating supply ball 272. Fuel at rail pressure passes into the system from supply passage 276 through supply ball chamber 274, past supply ball 272 through axial passage 284 of cartridge 270, and thence through control conduit 288, supply conduit 298 and past open check valve 300 into control valve cylinder 294, moving piston 296 to its fully advanced position, to the left as viewed. In this position, piston 296 closes off primary vent conduit 308 and unseats ball 314, allowing rail pressure fuel to pass from supply passage 276 through conduit 318, ball chamber 316, ball seat member 312, cylinder 294, and inlet/vent passage 256 into low pressure intensifier cylinder 252, producing the downward intensification stroke of intensifier pistons 254 and 258 and thereby charging the accumulator. The control System 250 has thus prepared the injector for an injection event, and as long as solenoid 290 is energized, the system will remain ready to effect the two-stage needle lift sequence.
The two-stage injection event is initiated by deenergization of solenoid 290, which instantaneously shifts solenoid valve 264 to its condition illustrated in FIG. 19, with supply ball 272 seated and vent ball 278 unseated. Check Valve 300 is now seated, and the only escape path for fuel from control valve cylinder 294 behind piston 296 is through bleed orifice 302. At the instant solenoid 290 is deenergized, full rail pressure is present in cylinder 294 in front of piston 296, such pressure biasing piston 296 in the direction of retraction, to the right as viewed. Piston 296 now retracts to the right at a rate controlled by the variable bleed orifice 302, first allowing ball 314 to seat, and then enlarging the volume in cylinder 294 on the head side of piston 296, which reduces the fluid pressure in low pressure intensifier cylinder 254 and allows incremental upward movement of intensifier pistons 252 and 258, reducing the intensified pressure above the needle and causing the low-lift or prelift increment of needle lift for the pilot charge to be injected.
FIG. 19 illustrates the control system 250 in this low-lift or prelift condition, the space between the vertical arrows to the left of FIG. 19 illustrating the low-lift increment of movement of the intensifier pistons. The low-lift condition remains in effect as long as piston 296 blanks off primary vent conduit 308 as seen in FIG. 19, the time interval of the low-lift condition being determined by the rate at which fuel bleeds from behind piston 296 through variable bleed orifice. 302. The main injection event commences when the reduced head portion 310 of piston 296 comes into registry with primary vent conduit 308 as piston 296 retracts from its position shown in FIG. 19 to its position shown in FIG. 20. The space between the vertical arrows to the left of the diagram of FIG. 20 illustrates the full lift increment of movement of the intensifier pistons.
While the two-stage needle lift hydraulic control system 250 of FIGS. 18-20 has been shown and described above applied to an intensified type accumulator injector, it is to be understood that it is equally applicable to an unintensified type accumulator injector, as for example the injector shown in FIGS. 14-17. Applying the system 250 of FIGS. 18-20 to injector 152 as seen in FIG. 14, inlet/vent passage 256 for the actuating fluid would be connected to inlet/vent passage 176 of unintensified injector 152. Then the hydraulic system 250 will apply the two-stage venting directly to spring cavity 218 and hence directly to the top of needle 204 so as to produce the two-stage needle lift.
Another form of two-stage needle lift control system is shown in FIGS. 21 and 22, which has a hydraulic control circuit that is very similar to the hydraulic circuit of the form shown in FIGS. 18-20, but which incorporates a positive stop to accurately define the first increment of needle lift. The system of FIGS. 21 and 22 is also shown applied to an intensified form of accumulator injector. The control system of FIGS. 21 and 22 embodies a stop piston in axial alignment with the needle and its plunger, and has the intensifier offset to the side. This structural arrangement of the injector is illustrated in FIG. 21, which will first be described, while the implementing hydraulic circuit is diagrammatically illustrated in FIG. 22.
Referring to FIG. 21, the injector is generally designated 330, and has an upper body 332 with an intensifier portion 334 off to one side, and a stop piston portion 336 generally axially aligned with the injector needle. Axially aligned with and below stop piston body portion 336 is accumulator body 338, with a lapped seal therebetween. Nozzle body 340 defines the lower end portion of injector 330, and has a lapped seal fit against the lower end of accumulator body 338. The three bodies 332,338 and 340 are clamped together by injector housing 342, with accumulator body 338 and nozzle body 340 seated within housing 342, and the stop piston portion 336 of upper body 332 threadedly coupled in the upper end of housing 342. An O-ring seal 344 is engaged between the top of housing 342 and upper body 332.
The intensifier portion 334 of injector 330 is only diagrammatically illustrated, and it is to be understood that it has components similar to those of the intensifier portion of injector 10 illustrated in FIGS. 1-13, and functions in essentially the same way. The intensifier portion 834 of injector 330 includes low pressure intensifier piston 346 slideable in low pressure cylinder 348, with inlet/vent passage 350 in communication with low pressure cylinder 348. High pressure intensifier piston 352 is slideable in high pressure cylinder 354.
An intensified pressure conduit 356 leads from the inner, lower end of high pressure cylinder 354 downwardly through stop piston body portion 336 to a check valve 358 which serves as the inlet to the primary accumulator cavity. Thus, intensified pressure conduit 356 delivers high pressure fuel through check valve 358 into a longitudinally arranged accumulator bore 360 in the same manner that intensified pressurized fuel in the first form of the invention is-delivered through check valve 88 into accumulator bore 90 as seen in FIG. 4.
Below the interface 361 between the bottom of stop piston body portion 336 and the top of accumulator body 338, the structure and operation of injector 330 of FIG. 21 are essentially the same as they are in injector 10 of FIGS. 1-8 below the top surface 24 of its accumulator body 26. Minor variations will be noted below. Thus, the primary accumulator cavity of injector 330 consists of a series of accumulator bores like bore 360 peripherally spaced about accumulator body 338 which are in communication with each other through annular cavity 362 in the bottom of accumulator body 338. The primary accumulator cavity communicates from annular cavity 362 through passages 364 in nozzle body 340 to kidney cavity 366, and thence to needle cavity 368. Needle 370 is normally biased to its closed position by needle spring 372 and guide/damper 374 which are located in spring cavity 375.
Needle plunger 376 extends upwardly from guide/damper 374 through spring 372 and plunger guide bore 378 in the upper end portion of accumulator body 342. Needle plunger 376 has a sliding fluid-tight seal in its guide bore 378, and its upper end is exposed to a small annual intensifier cavity 380. Intensifier cavity 380 communicates through a passage 382 and high pressure conduit 356 to the high pressure intensifier cylinder 354.
A minor variation in injector 330 of FIG. 21 from injector 10 of FIGS. 1-13 is that a generally cylindrical annular clearance 384 is provided between the outer surface of accumulator body 338 and the inner surface of housing 342. This clearance 384 has an outward frustoconical flare at its upper end from which a vent passage 386 extends upwardly through stop piston body portion 336. Vent passage 386 is vented to a fuel supply source at relatively low pressure, as for example about 30 psig. Annular clearance 384 and vent passage 386 serve two functions. First, spring cavity 375 is filled with liquid fuel through a radial passage 387 from clearance 384 to cavity 375. Second, any leakage between the lapped interfaces between the stacked bodies will accumulate in the annular clearance 384 and be vented through vent passage 386.
A stop piston 388 is provided in injector 330 to positively define both the small incremental prelift of the needle and the extent of the full lift of the needle. Stop piston 388 is axially slideable a short distance in a cylinder 390 which is axially aligned with needle 370 and its plunger 376. Stop piston 388 has a downwardly extending coaxial rod or plunger portion 392 which is slideable with a fluid-tight seal in a bore 394. Although stop piston 388 and its plunger 392 are illustrated as an integral unit, they may, if desired, be separate parts and will function as a unit. A generally radially oriented vent passage 396 provides pressure relief from the bottom of cylinder 390 to the annular clearance 384, and hence to vent passage 386.
Upward travel of stop piston 388 is limited by piston stop member 396 which is located by means of a threaded positioning plug 400. Positioning plug 400 may, if desired, be threadedly axially adjustable to adjust the axial position of piston stop member 398. Stop member 398 determines the uppermost limit of travel of stop piston 388, and consequently of needle 370 and its plunger 376, as will be discussed below. An inlet/vent passage 402 provides alternate rail pressure and vent communication through positioning plug 400 and stop member 398 to stop piston cylinder 390.
The small increment 404 of needle prelift for the pilot charge is defined by the space between the upper end of needle plunger 376 and the lower end of stop piston plunger 392 with needle 370 in its closed position and stop piston 388 in its lowermost position as these parts are illustrated in FIG. 21. This is the position of the parts after completion of an intensification stroke with injector 330 prepared for an injection event. At such time rail pressure is being applied both to low pressure intensifier piston 346 through inlet/vent passage 350 and to stop piston cylinder 390 through inlet/vent passage 402. At such time high intensified pressure is being applied from high pressure intensifier cylinder 354 through high pressure conduit 356 and passage 382 to the small intensifier cavity 380. The accumulator cavity is at intensified pressure, applied through check valve 358. Full intensification pressure within intensifier cavity 380 holds the needle down, the downward force of high intensification pressure in intensifier cavity 380 against needle plunger 376 plus the downward force of spring 372 on needle 370 being greater than the upward force of accumulator pressure on the needle.
An injection event is initiated by partial venting of pressure from low pressure intensifier cylinder 348 out through inlet/vent passage 350, as will be explained in connection with FIG. 22. Such initial partial venting of low pressure intensifier cylinder 348 is not accompanied by any venting from stop piston cylinder 390, which is maintained at rail pressure. Lowering of the intensifier pressure by partial retraction or backing off of the two intensifier pistons 346 and 352 will cause the intensified pressure within intensifier cavity 380 to be lowered sufficiently for the upward force of accumulator pressure on needle 370 to overcome the downward force of intensifier cavity pressure on piston plunger 376 and the downward force of spring 372, at which time needle 370 will shift upwardly in its small initial increment 404 of lift which is stopped when the upper end of needle plunger 376 engages the lower end of stop piston plunger 392. At this time the full rail pressure against stop piston 388 blocks further upward movement of the needle. The time interval during which the needle is at this small prelift increment is adjustable by the hydraulic circuit of FIG. 22, and at the end of this time interval rail pressure is vented from stop piston cylinder 390 through inlet/vent conduit 402, allowing the needle to move upwardly a further increment 406 to its fully opened position which is determined by engagement of the upper end of stop piston 388 against stop member 398. The main injection event then occurs, and ends when accumulator pressure drops sufficiently for needle spring 372 to close needle 370.
FIG. 22 illustrates a hydraulic circuit 410 for operating the positive stop injector of FIG. 21. The hydraulic circuit 410 of FIG. 22 is the same as the hydraulic circuit of FIGS. 18-20 except for the addition of circuit components associated with stop piston 388 and its cylinder 390 which provide the positive incremental prelift stop for the needle. These additional components include a stop cylinder feed passage 412 which connects to control conduit 288 and communicates through a check valve 414 to stop cylinder inlet/vent passage 402. Also added in the hydraulic circuit of FIG. 22 is a stop cylinder vent passage 416 which connects stop cylinder inlet/vent passage 402 to control valve cylinder 294 at the same axial position as primary vent conduit 308.
Energization of solenoid 290 produces the intensification stroke of intensifier pistons 346 and 352 by lifting supply ball 272 off of its seat, providing rail pressure fuel through passages 284, 288 and 298 past check valve 300 into control valve cylinder 294 to extend control piston 296 to its fullest extent to the left as viewed in FIG. 22. In this position of piston 296, its ball actuator pin 320 lifts ball 314 off of its seat, admitting rail pressure fuel through-conduits 276 and 318, chamber 316, valve seat 312, cylinder 294, and inlet/vent passage 350 to low pressure intensifier cylinder 348.
Simultaneously with pressurization of the intensifier cavity 380, rail pressure fuel is provided to stop piston cylinder 390 to place stop piston 388 in its positive stop position illustrated in FIG. 21. Such rail pressure fuel is provided from supply conduit 276 through chamber 274, conduits 284, 288 and 412, check valve 414, and stop cylinder inlet/vent passage 402.
Initiation of the two-stage injection event is caused by deenergization of solenoid 290, which causes solenoid valve supply ball 272 to seat and vent ball 278 to become unseated. The first, small increment stage of needle lift is produced by the hydraulic circuit 410 of FIG. 22 in the same way as it was produced in the hydraulic circuit 250 of FIGS. 18-20, except for the positive limitation placed on the first-stage needle lift by stop piston 388. Thus, upon deenergization of solenoid 290, control valve piston 296 slowly retracts to the right in FIG. 22 as fuel in cylinder 294 behind piston 296 bleeds out through bleed orifice 302, passages 304,288 and 284, vent chamber 280, and vent passage 282. Such retracting movement of piston 296 lowers the pressure on its head side which lowers the pressure in low pressure intensifier cylinder 348 via inlet/vent passage 350, allowing intensifier pistons 346 and 352 to partially retract. When such partial retraction is sufficient, lowered pressure in intensifier cavity 380 of FIG. 21 will allow the needle to lift in its small first-stage increment which is positively defined by abutment of the needle plunger 376 against stop piston plunger 392. At this time the full rail pressure is maintained in stop piston cylinder 390 because stop cylinder vent passage 416 is closed off by control valve piston 296 and stop cylinder feed passage check valve 414 is closed.
As control piston 296 continues 2to retract to the right in FIG. 22 because of fuel bleeding through orifice 302, the piston's reduced head portion 310 comes into registry with both primary vent conduit 308 and stop cylinder vent passage 416 at the same time, whereby low pressure intensifier cylinder 348 and stop piston cylinder 390 are simultaneously vented through control cylinder 294 and primary vent conduit 308. This simultaneously removes the two barriers of high intensification pressure and stop piston 388 from above needle plunger 376, allowing full lift of the needle.
FIG. 23 illustrates a further modified intensified form of the invention generally designated 10c which utilizes a needle stop and damping plate or member to accomplish the two-stage needle lift in a manner similar to the forms of the invention shown in FIGS. 8, 9 and 10. However, in the form shown in FIG. 23, stop plate member 71c has a lap-fitted pin 410 axially 32 slideable with a fluid-tight seal in an axial bore 412 through stop member 71c. As with the stop plates in the forms shown in FIGS. 8, 9 and 10, stop member 71c has its bottom surface sealingly lap-fitted to a shoulder formed by the top surface 24 of accumulator body 26. With this construction, intensified pressure from damper cavity 70c is not directly transmitted through a hole in the stop plate or member as in the other forms, and the needle hold-down force prior to the injection event is provided by intensified fluid pressure against the top of pin 410. This arrangement minimizes the possibility of intensified pressurized fluid getting underneath stop member 71c during the first, prelift stage of needle movement to assure against premature ending of the first stage needle lift event.
As with the form of the invention shown in FIG. 8, the upper end 140 of needle plunger 136 is offset below the upper surface 24 of accumulator body 26 in the closed position of the needle. The amount of this offset clearance determines the extent of the small initial needle lift to provide the pilot charge.
When high pressure intensifier piston 52 starts to retract at the beginning of an injection event, lowered fluid pressure within damper cavity 70c enables the upward force of accumulator fluid pressure on the needle to overcome the downward forces of the needle spring and fluid pressure on pin 410 to allow the prelift increment of needle movement to occur. Such first-stage needle movement is stopped by abutment of the upper end 140 of needle plunger 136 against the bottom surface of stop member or plate 71c. At this time, the downward force of fluid pressure in damper cavity 70c against stop member 71c and its pin 410 plus the downward force of the needle spring are still greater than the upward force of accumulator fluid pressure on the needle, to effect the positive stop of needle plunger 136 against seated stop member 71c. As intensifier piston 52 further retracts upwardly to further reduce the fluid pressure in damper cavity 70c, the upward force of accumulator fluid pressure against the needle will, in sequence, overcome the downward forces of fluid pressure against stop member 71c and its pin 410 and of the needle spring, to enable needle plunger 136 to unseat stop member 71c and allow the needle to move to its fully opened position which is defined by engagement of the upper surface of stop member 71c against stop shoulder 73c at the top of damper cavity 70c.
While the present invention has been described with regard to particular embodiments, it is to be understood that modifications may readily be made by those skilled in the art, and it is intended that the claims cover any such modifications which fall within the scope and spirit of the invention as set forth in the appended claims. | 4y
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FIELD OF THE INVENTION
[0001] This invention relates to transition metal compounds and their use in imageable coatings.
BACKGROUND OF THE INVENTION
[0002] For many years, heat-sensitive imaging sheets have been used for copying, thermal printing, thermal recording and thermal labelling. More recently, the development of scribing lasers has enabled the use of thermally-sensitive imaging materials for the coding and marking of both sheet materials and shaped objects that may or may not be self-supporting.
[0003] Two classes of colour-forming reactants have commonly been used for thermographic materials, i.e. leuco lactone or spiropyran compounds normally developed by phenolic compounds, e.g. as described in U.S. Pat. No. 3,846,153, and heavy metal salts of organic acids that can react with ligands to give coloured complexes, e.g. as described in U.S. Pat. No. 2,663,654. The use of both these types of compounds depends on effecting a physical separation of the solid components, through dispersing them in a polymer binder, coating them on a suitable support, and melting at least one of them to cause colour formation. When coated and dried, dispersions of solid materials, by their nature, result in layers of some opacity. This is normally acceptable on opaque substrates such as paper, but limits applications on transparent substrates such as clear Mylar (polyester) film and transparent packaging films. Examples of such applications are where a film transmission original is required or, in transparent film packaging applications, where film opacity would obscure sight of the packaging contents or container surface.
[0004] There is therefore a need for transparent, thermally-sensitive imaging layers for coating on transparent or semi-transparent film supports and reflective supports such as can-metal. Further, there is a need for transparent laser-sensitive imaging materials that may be coated or printed on shaped or formed objects such as bottles and other containers for labelling or coding applications. Naturally, for these applications, the coatings should adhere to the substrate firmly and be robust, i.e. have good resistance to the types of chemical and physical treatment encountered in the end use environment. In general, organic solvent-based compositions containing solvent-soluble binders give, on drying, tougher, better adhering layers of greater transparency and water-resistance than like water-based compositions.
[0005] The use of organic amine molybdates in thermal imaging layers is described in U.S. Pat. No. 2,910,377 (see Example 10) and U.S. Pat. No. 3,028,255 (where the exemplified amines are primary amines). This use is confined to copy paper sheets, and the molybdate is dispersed by prolonged ball-milling in a resinous binder to give a suspension, used for coating. Such a suspension, when coated and dried on a transparent film support, would cause loss of transparency.
[0006] U.S. Pat. No. 4,217,409 (see Examples 10 and 12) describes the use of isopropylammonium molybdate in an acidic aqueous solution of polyvinyl alcohol as a coating that, when applied to a substrate, gives a laminar material sensitive to electromagnetic radiation including IR, visible and UV radiation. Polyvinyl alcohol solutions often have poor coating properties towards polyester film and the hazy dried films detach readily. The dried and imaged coating would also be susceptible to physical and chemical damage, most notably chemical damage from water. Isopropylamine is volatile and would cause odour should the material be contacted with aqueous alkali.
[0007] U.S. Pat. No. 4,406,839 describes the synthesis of organic solvent-soluble amine molybdates useful as smoke retardants and made from a variety of amines. Examples employ high molecular weight amines such as tridodecylamine.
[0008] Amine molybdates, their synthesis and uses, are also described in U.S. Pat. No. 2,910,377, U.S. Pat. No. 3,028,255, U.S. Pat. No. 3,290,245, U.S. Pat. No. 4,053,455, U.S. Pat. No. 4,153,792, U.S. Pat. No. 4,217,292, U.S. Pat. No. 4,217,409, U.S. Pat. No. 4,226,987, U.S. Pat. No. 4,266,051, U.S. Pat. No. 4,406,837, U.S. Pat. No. 4,406,838, U.S. Pat. No. 4,406,839, U.S. Pat. No. 4,406,840, U.S. Pat. No. 4,410,462, U.S. Pat. No. 4,410,463, U.S. Pat. No. 4,424,164, U.S. Pat. No. 4,425,279, U.S. Pat. No. 6,217,797 and U.S. Pat. No. 6,355,277.
SUMMARY OF THE INVENTION
[0009] The present invention is based at least in part on the finding that amine molybdates and analogous compounds, some of which may be new, have properties that render them suitable for imaging. In particular, they are soluble in at least some organic solvents, are compatible with film-forming solvent-soluble organic binders, and give solutions that, when coated on an inert substrate such as clear polyester film and dried, form a continuous substantially visible light-transparent layer on the support. Such layers are thermally sensitive and find utility in thermographic materials for imaging by scanning laser or thermal printer, to provide effective marking, without opacification in the non-image areas.
[0010] According to one aspect of this invention, a process for forming an image on a substrate, comprises coating the substrate with a solution, in an organic solvent, of an amine compound of molybdenum, tungsten or vanadium, wherein the compound changes colour on heating or irradiation, and heating or irradiating the coating.
[0011] A further aspect of the invention is a coated substrate, wherein the amine is a secondary or tertiary alkylamine in which each alkyl group has up to 12 carbon atoms and the amine has up to 24 carbon atoms. Other aspects are solutions of the amine compound and a photopolymerisable monomer or a thermoplast.
[0012] The organic solvent solubility properties of the amine molybdates of the invention permit the avoidance of the time-consuming, wasteful and costly milling processes normally involved in the preparation of coating mixtures for known thermally sensitive imaging materials. They also allow thermally sensitive layers of good transparency and gloss to be made on transparent substrates such as Mylar and commercially available packaging films such as polypropylene.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0013] Preferred compounds for use in the invention are amine molybdates. The term “amine molybdate” (of which an example is ethylamine molybdate) is used herein to describe compounds whose structure may be ill-defined, and which are also sometimes called the corresponding ammonium molybdates (e.g. ethylammonium molybdate), which implies that the compounds are salts. The generic term “amine molybdate” refers to complexes or salts formed on reacting an amine to give an amine molybdate or amine isopolymolybdate. For reference, see Cotton & Wilkinson; Advanced Inorganic Chemistry 2 nd Edition 1967 Chapter 30 Section 30-C-2&3.
[0014] Amine molybdates will be described herein, for the purpose of illustration. Such compounds for use in the invention may be formed from amines and molybdate and polymolybdate (VI) acids and their salts and can be can be thermally activated in a coating, to give an image. Other compounds suitable for use in the invention, including those based on tungsten or vanadium, can be made in similar manner.
[0015] More specifically, such compounds are made, for example, using known saturated secondary or tertiary aliphatic dialkyl or trialkyl monoamines having boiling points (at 1 atmosphere pressure) equal to or above 150° C. and melting points below about 80° C., and with individual alkyl groups which are different or, preferably, the same, e.g. having from 3 to 12, preferably 5 to 12, more preferably 5 to 10, and most preferably 6 or 7 to 10 carbon atoms. Typically, the compound has a total of 7 to 24 C atoms. Salts of the compounds may also be used, such as amine acetates or chlorides. Representative amines are dipentylamine, tripentylamine, di-n-hexylamine, tri-n-hexylamine, bis(2-ethylhexyl)amine, di-n-octylamine and tri-n-octylamine. It will be understood that one or more amine compounds may be used.
[0016] The amine molybdates are made by reacting the amine with a molybdenum compound, e.g. in oxidation state VI, such as molybdenum trioxide, molybdic acid, ammonium dimolybdate, ammonium heptamolybdate, ammonium octamolybdate, sodium molybdate or commercial “molybdic acid” (which comprises primarily one or more ammonium molybdates). A representative and preferred amine molybdate for use in the invention is bis(2-ethylhexyl)amine octamolybdate.
[0017] Amine molybdates suitable for use in the invention have one or more of the following properties:
(i) Individually soluble in at least one organic solvent (ii) Transparent or near transparent film-forming properties on specified commercial polymer substrates when applied by coating or printing an organic solvent solution (iii) Thermal sensitivity manifested as a colour change of good visual discrimination when a layer comprising the amine molybdate is exposed thermally imagewise by a scanning laser and/or heat block imaged by a thermal printer (iv) Compatibility with at least one solvent-soluble binder polymer as indicated by the formation of a near transparent film of a blend (v) Preparation using an amine precursor of low volatility, so that there is low risk of a hazard if the amine molybdate layer is exposed to aqueous alkali and the amine is released
[0023] The amine molybdates are soluble in organic solvents, are compatible with film-forming solvent soluble organic binders, and give solutions that, when coated or printed on an inert substrate such as clear Mylar polyester film and dried, form a continuous layer of the amine molybdate that is substantially transparent to visible light. Such layers are thermally sensitive and find utility in thermographic materials and on 3D objects for imaging by scanning laser or thermal printer. Clear layers formed by means of the invention may also be useful on opaque substrates because they can impart desirable gloss, as distinct from compositions containing suspended insoluble molybdates that give matt surfaces.
[0024] Imaging elements comprising these amine molybdates may be supported on a flexible sheet substrate, preferably a flexible transparent sheet substrate such as polyester. Alternatively a rigid 3D object substrate may be used such as the external surface of a container. There should be a good adhesive bond between imaging element and substrate. The substrate should be able to withstand laser imaging of the element (comprising the amine molybdate) without unacceptable degradation or deformation upon laser or thermal imaging. Preferred substrates are transparent or translucent materials that absorb the IR radiation output of the laser to some extent: otherwise the substrate may act as a heat sink to the laser-exposed areas of the imaging element, reducing layer sensitivity. In this respect Mylar polyester film is better than unfilled polypropylene or polyethylene.
[0025] The solvent-soluble molybdates used in the invention can be applied from solution and dried to give a near-transparent layer. Film-forming compositions containing these amine molybdates give layers having good adhesion transparency and imagewise thermal sensitivity. Such layers can have filmogenic and transparency properties, e.g. on commercial transparent polymer film supports such as clear polypropylene, providing near-transparent, thermally sensitive sheet or web materials. The solvent-soluble amine molybdates also show good compatibility when blended with specified organic solvent-soluble polymeric binders; these blends can also form useful substantially transparent thermally sensitive layers, to provide thermographic materials.
[0026] The invention also provides amine molybdate compositions that, when applied as a solvent coating to commercially available transparent film or supports or otherwise incorporated on or within transparent or semi transparent polymer layers, give direct thermally sensitive imaging media having excellent stability transparency and sensitivity properties for thermal laser imaging or, if appropriate, thermal printing. The coating weight of the dry coating is normally in the range 0.5 to 20 g/m 2 , preferably 1 to 10 g/m 2 .
[0027] The invention also provides thermally sensitive imaging materials comprising a layer comprising the amine molybdate, adhering to a substrate or within a substrate which is preferably an optically near transparent or translucent polymeric material. Suitable substrates include paper, laminates and films of the type described above. Another aspect of this invention is thermally imageable materials comprising the amine molybdate and incorporated on a substrate.
[0028] Amine molybdates may also be useful in dispersed form in a thermographic layer. Some are readily dispersed in water, and may be used, say, on an opaque substrate like paper to give a matt layer. Thus, depending on the conditions, the amine molybdates may be used for both transparent/glossy materials and also opaque/matt materials.
[0029] Thermally imageable materials comprising an amine molybdate in solid solution or dispersion in a molten material comprising a thermoplastic polymer, may be made by cooling the material whilst rolling it flat or forming it into a shape, such as the shape of a container.
[0030] Thermally imageable materials comprising an amine molybdate in solution or dispersion in a liquid photopolymerisable composition may be made by photopolymerising the composition.
[0031] It will be appreciated by one of ordinary skill in the art that it is possible to incorporate additives of various sorts in the imaging layers, and which might be beneficial in certain circumstances. Such additives include, for example, polymer binders, mild reducing agents to promote thermal printer performance, colorants such as dyes or pigments, antioxidants and other known stabilisers, antiblocking materials such as talc or selected silicas, and materials adsorbent to or reactive with any thermolysis products of laser imaging.
[0032] An additive of particular utility, in solution or suspension or in a separate layer, is an electron-donating dye precursor often known as a colour-former. When amine molybdates are incorporated in a layer with such colour-formers and thermally imaged, e.g. using a CO 2 laser, coloured images may be obtained. The colour may correspond to that obtained by the use of common colour developers such as certain phenols. Weak block images may also be obtained, e.g. using a heat sealer at 100-120 C and contact times of 1-10 seconds. Thus the amine molybdate acts as an electron acceptor and colour developer for at least some of these colour-formers. The low melting point of amine molybdates means that they can be fused with colour-formers, if desired.
[0033] Protective polymer or other layers on the imaging layer may be useful in some circumstances. For example, such layers may prevent or reduce mechanical or chemical damage to the unexposed or exposed thermally sensitive layers of the invention. Layers comprising mild reducing agents may also be added to promote thermal printer performance. Such layers may also act to reduce emanation of any thermolysis products of laser imaging. Such layers can be applied by known means such as lamination or coating.
[0034] As indicated above, an image can be formed by the application of heat. Preferably, heat is applied locally, on irradiation with a laser. Suitable lasers include those emitting at high energy, including Nd-YAG lasers and CO 2 lasers, the latter typically at a wavelength of 10,600 nm. In many cases, it may be desirable to use a low-energy laser, such as a diode laser, typically emitting light at a wavelength in the range of 800-1500 nm. In certain circumstances, this energy input may be insufficient to cause the desired reaction, and the composition to be irradiated then preferably comprises a suitable absorbent material.
[0035] IR-absorbent materials are known. In general terms, any suitable such material may be incorporated, for the purposes of this invention, and can be chosen by one of ordinary skill in the art. A particularly preferred IR absorber for use in the invention is a conducting polymer, by which is meant a material that, in the polymerised state, comprises linked monomers (typically rings) that are conjugated and which can therefore allow delocalisation/conduction of positive or negative charge. The conjugation allows an absorption shift that can be controlled such that it applies to the wavelength of irradiation, and which may also depend on the concentration of the polymer.
[0036] Examples of monomers that can be conjugated to give suitable conducting polymers are aniline, thiophene, pyrrole, furan and substituted derivatives thereof. Such polymers, in addition to providing the desired means of transferring heat from a low-power laser, have the advantage that they do not readily diffuse out of the coating material. They can also act as the polymer binder. Yet another advantage of such materials is that they can be colourless, even at high loading (up to 5% by weight); this is by contrast to monomeric species that have been used, such as phthylocyanine, which absorb at about 800 nm but give the composition a greenish tinge, even at a loading of 0.1% by weight.
[0037] Depending on the components to be irradiated, a black or coloured image may be obtained. The colour may be dependent on the irradiation power; thus, for example, a blue colour may be overpowered to black.
[0038] Multi-colour printing may also be achieved, e.g. using different colour-formers (and, if necessary, absorbers) responsive to different irradiation wavelengths. For example, UV, diode and CO 2 lasers may be used to give three-colour printing, by providing appropriate, different colour formers at different/overlapping locations on the substrate.
[0039] The initial colour of coating and image achieved on activation is not limited. Theoretically, any initial or final colour (red, blue, green, etc) is achievable and the energy required to develop the image (e.g. 100-140° C./2-4 Watts) can be controlled within a range. Additionally, a step-change of the image colour produced can be controlled with activation (e.g. 150-200° C./3-5 Watts), and so more than one distinct colour is possible from the same coating.
[0040] In general, the colour developer can be one or more of a range of water-compatible transition metal complex materials as an amine molybdate.
[0041] The colour former can be one or more of a range of established basic dyes such as fluorans, phthalides etc.
[0042] The binder can be one or more of a range of water-soluble or amine-stabilised emulsion polymers, for a water-borne dispersion ink, or a solvent-soluble polymer for a solvent-borne dispersion or solution ink. Acrylic polymers can be used in each case.
[0043] Pigments can be water-dispersible inorganic or organic additives such as calcium carbonate etc.
[0044] One or more of a range of additives can be utilised, including surfactants or lubricants such as zinc stearate etc.
[0045] The IR-sensitive coating can be applied by a range of methods such as flood coating, flexo/gravure etc.
[0046] The IR-sensitive coating can be applied to a range of substrates such as self-adhesive label etc.
[0047] A protective layer of a film-forming water-borne top-coat ink can be applied onto the IR-sensitive coating.
[0048] The IR-absorber can be one or more of a range of water-compatible organic or inorganic materials, for a water-borne dispersion ink, or a solvent-compatible, organic or inorganic material for a solvent-borne dispersion or solution ink (in the latter case, the material is preferably solvent-soluble).
[0049] The following Examples illustrate the invention.
EXAMPLE 1
Bis(2-ethylhexyl)amine octamolybdate
[0050] The following synthesis is adapted from the method given in U.S. Pat. No. 4,217,292 (Example 3) for dodecylammonium octamolybdate.
[0051] In a 500 ml flange flask vessel were weighed molybdenum trioxide (15.53 g; Aldrich 99%; 10-20 μm particle size by Fisher sub-sieve sizer), deionised water (300 g) and ammonium chloride (8.6 g) (Aldrich reagent). The mixture was stirred vigorously while bis(2-ethylhexyl) amine (13.03 g; Aldrich) was added dropwise over 10 minutes. The vessel contents were then heated to reflux with stirring and refluxed for 4 hrs. A pale green-blue tarry material formed that part adhered to the vessel walls. On cooling, the reaction mixture to room temperature, the tarry product formed a glass-like solid. The solid was collected by filtration with some manipulative loss, ground and washed successively with deionised water and finally with isopropanol. Finally the pale green-blue product was dried in an oven for 24 hrs at 65° C. Yield was 26.2 g. It was readily soluble in 2-butanone to give a pale-green solution. A trace of white material (perhaps unreacted MoO 3 ) remained undissolved.
EXAMPLE 2
Coating Composition without Polymer Binder
[0052] Bis(2-ethylhexyl)amine octamolybdate (10 g) was dissolved in 2-butanone (30 g). The solution was separated from a trace of insoluble white solid impurity to give a solution that can be used as a coating composition of the invention.
EXAMPLE 3
Thermally Imageable Material
[0053] The solution prepared in Example 2 was coated on each of four supports, i.e. opaque white (titanium dioxide-filled) Mylar film, clear Mylar (polyethylene terephthalate) film, domestic aluminium foil, and polypropylene packaging film (UCB). This was done using a wire coating bar, giving a 12 μm on wet film, and dried using warm air to give a thermally imageable material.
[0054] Continuous glossy well-bonded films were obtained in each case. The coatings on clear Mylar and polypropylene were transparent and all were non-tacky when cool. The dry coating weights were found to be about 3 g/m 2 . The resulting coated materials were exposed imagewise using a CO 2 scribing laser beam of 0.3 mm diameter at a scan speed of 1000 mm/sec. A distinct grey-black image of alphanumeric characters was obtained when the power was set at 3-4 Watts for Mylar and aluminium foil substrates. The images were less legible at 2 Watts, indicating sub-optimum exposure. With the polypropylene substrate, images were obtained at about 6 W.
EXAMPLE 4
Coating Composition Containing Polymer Binder
[0055] A solution of bis(2-ethylhexyl)amine octamolybdate (10 g) was dissolved in 2-butanone (30 g). The solution was separated from a trace of insoluble white solid impurity. 4 g of this solution was mixed with 4 g of a 15% by weight solution of Elvacite 2041 (a methyl methacrylate homopolymer resin grade manufactured by INEOS) binder in 2-butanone to give a coating solution.
EXAMPLE 5
Thermally Imageable Film
[0056] The solution of Example 4 was coated on packaging grade polypropylene film using a wire-wound bar (giving a nominal 12 μm wet film thickness) and dried using warm air to give a transparent coated film. The transparency observed indicates good compatibility of the amine molybdate and the acrylic binder. The dry coating weight was found to be 2.8 g/m 2 . The resulting coated film of the invention had high transparency. It was exposed imagewise using a CO 2 scribing laser beam of 0.3 mm diameter at a scan speed of 1000 mm/sec. A distinct grey-black image of alphanumeric characters was obtained when the power was set at 3-4 Watts. Some lifting of the image was observed at 4 Watts. The image was less legible at 2 Watts, indicating inadequate exposure.
EXAMPLE 6
Red Thermographic Film
[0057] To 0.4 g of a 25% by weight solution of bis(2-ethylhexylamine) octamolybdate in 2-butanone was added with thorough mixing 1.0 g of a 33.3% by weight solution of Elvacite 2044 also in 2-butanone (Elvacite 2044 is a n-butyl methacrylate-based acrylic resin manufactured by INEOS Acrylics). In this composition was dissolved by agitation 0.1 g of a commercial electron-donating colour-former (Pergascript Red I-6B manufactured by Ciba Specialty Chemicals and described as a bisindolyl phthalide compound). The resulting pale yellowish-pink solution was coated on clear Mylar film using a 25 wire bar and dried using warm air. A transparent film resulted.
[0058] A pale red image resulted on block imaging the film at 100° C. using a heat sealer and a contact time of 10 seconds. A distinct red image resulted from imaging the film using a CO 2 scribing laser beam of 0.3 mm diameter at a scan speed of 1000 mm/second and set at 3 Watts power.
EXAMPLE 7
Water-Borne Dispersion Inks
[0059] The effect of the presence of an IR absorber in an ink formulation of the invention was determined. Blue and red water-based acrylic-emulsion inks of PVOH-stabilised dispersion (comprising PBI2RN or PRI6B colour former) were assessed.
[0060] A “standard” formulation of the invention was used, comprising the following proportions of components (% w/w):
Binder 16.0 Active Pigment 7.0 Colour Former 7.0 Fluid 70.0
[0061] Various “active” formulations were used, each containing the IR absorber Baytron P (HC Starck), a conducting polymer. The proportions of IR absorber used were 1.0, 2.5 and 5.0% (w/w). In, for example, formulations comprising 5.0% Baytron P, the composition was:
Binder 15.2 Active Pigment 6.7 Colour Former 6.7 Fluid 64.4 IR Absorber 5.0
[0062] The components were selected from:
Binder Gohsenol GH-17 polyvinyl alcohol and Texicryl acrylic emulsion; Active Pigment Bis(2-ethylhexylamine)octamolybdate and di(cyclohexylamine)octamolybdate Colour Former Pergascript blue I-2RN crystal violet lactone and red I-6B; Fluid water, dilute ammonium hydroxide etc; and IR Absorber Baytron P
[0063] A 940 nm Rofin Dilas DF060 Diode Laser and K-bar 2.5-coated substrates were used for image forming.
[0064] The results are shown in Table 1. A good image was obtained when Baytron P was present.
TABLE 1 IR Level Imaged Ink Type Absorber (% w/w) Unimaged (940 nm) Standard, blue — n/a Off-white (slight) No image ″ — n/a ″ ″ Active, blue Baytron P 1.0 ″ ″ ″ ″ 1.0 ″ Blue Image ″ ″ 2.5 ″ ″ ″ ″ 2.5 ″ ″ ″ ″ 5.0 ″ ″ ″ ″ 5.0 ″ ″ Standard, red — n/a White No image ″ — n/a ″ ″ Active, red Baytron P 1.0 Off-white (slight) Red Image ″ ″ 1.0 ″ ″ ″ ″ 2.5 ″ ″ ″ ″ 2.5 ″ ″ ″ ″ 5.0 ″ ″ ″ ″ 5.0 ″ ″
[0065] Samples of the blue ink formulations were coated with K-bar 2.5 onto Rafaltac Raflacoat (RC) and Hi-Fi polyester (PE) substrates. The coated substrates were then used for Nd:YAG (1064 nm) laser text imaging. Two formulations comprised Baytron P, two did not. The results are shown in Table 2.
TABLE 2 IR Absorber at 5.0% Imaged Ink Type (w/w) Substrate Unimaged (1064 nm) Standard, blue — RC White No Image Active, blue Baytron P RC Off-White (grey) Blue Text Standard, blue — PE White No Image Active, blue Baytron P PE Off-White (grey) Blue Text
[0066] The coatings in which Baytron P was absent gave no image or very faint text. PE-based samples gave better results than RC-based ones. Where images were obtained (i.e. when Baytron P was present), they were sharp and well-defined.
EXAMPLE 8
Solvent-Borne Dispersion Inks
[0067] Experiments similar to those of Example 7 were performed except that solvent-based inks were used.
[0068] The “standard” formulation was composed of (% w/w):
Binder 21.7 Active Pigment 9.6 Colour Former 9.6 Fluid 59.1
[0069] The “active” formulations contained the IR absorber Iriodin LS820 (Merck). The composition of the 5% (w/w) “active” formulation was:
Binder 19.5 Active Pigment 8.6 Colour Former 8.6 Fluid 53.3 IR Absorber 10.0
[0070] The results are shown in Table 3. Again, the presence of an IR absorber allowed image formation to occur.
TABLE 3 Addi- Level tive % Imaged Ink Type Type w/w Unimaged (940 nm) Standard, blue — n/a Off-white (slight green) No image ″ — n/a ″ ″ ″ — n/a ″ ″ Active, blue Iriodin 5.0 Off-white (grey/green) Blue Image LS820 ″ Iriodin 5.0 ″ ″ LS820 ″ Iriodin 5.0 ″ ″ LS820 ″ Iriodin 10.0 ″ ″ LS820 ″ Iriodin 10.0 ″ ″ LS820 ″ Iriodin 10.0 ″ ″ LS820 Standard, red — n/a Off-white (pink) No image ″ — n/a ″ ″ ″ — n/a ″ ″ Active, red Iriodin 5.0 Off-white (grey/pink) Red Image LS820 ″ Iriodin 5.0 ″ ″ LS820 ″ Iriodin 10.0 ″ ″ LS820 ″ Iriodin 10.0 ″ ″ LS820 ″ Iriodin 10.0 ″ ″ LS820 ″ Iriodin 10.0 ″ ″ LS820
EXAMPLE 9
Solvent-Borne Solution Inks
[0071] Experiments similar to those of Examples 7 and 8 were performed except that solvent-based inks in acrylic methyl ethyl ketone (MEK) solution were assessed.
[0072] The ink formulations comprised 0.1% (w/w) Pro-Jet 900NP (Avecia), an IR absorber. Some formulations additionally comprised a UV absorber. In some cases, colour former (CF) was present at a ratio of 1:1 or 1:2 with the active pigment (CD). A typical formulation was composed of (% w/w):
Binder 23.7 Active Pigment 4.6 Colour Former 4.6 UV Absorber 6.7 Fluid 60.3 IR Absorber 0.1
[0073] The results are shown in Table 4. Generally, good images was obtained.
TABLE 4 Ink Type Unimaged Imaged (940 nm) no CF Clear (green) Dark Image ″ ″ ″ ″ ″ Incomplete Blue, CD:CF = 1:1 Clear (grey/green) Dark Image ″ ″ ″ ″ ″ Incomplete Blue, CD:CF = 1:2 ″ Dark Image ″ ″ ″ ″ ″ Incomplete Red, CD:CF = 1:1 Clear (grey/brown) Dark Image ″ Clear (green/grey) ″ ″ ″ Incomplete Red, CD:CF = 1:1 Clear (pink/brown) Dark Image ″ Clear (brown/grey) ″ ″ ″ Incomplete | 4y
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GOVERNMENT CONTRACT CLAUSE
The present invention was made or conceived during the performance of work under Contract No. EY-76-C-14-2170 with the U.S. Department of Energy.
CROSS-REFERENCE TO RELATED APPLICATION
Maraging superalloys and their method of heat treatment are described in U.S. patent application Ser. No. 370,439 filed on Apr. 21, 1982 as a continuation in part of U.S. patent application Ser. No. 305,411 filed on Sept. 24, 1981 and now abandoned. These alloys are ferritic in nature.
BACKGROUND OF THE INVENTION
The present invention pertains to precipitation hardening austenitic superalloys for use in neutron radiation environments. It especially relates to gamma prime hardening austenitic superalloys.
In fast breeder nuclear reactors of the liquid metal type, as well as in other, the fuel is encapsulated in cladding, typically of cylindrical form. A capsule containing the fuel is usually referred to as a fuel element or fuel rod. In accordance with the teachings of the prior art, the cladding is composed of stainless steel, typically AISI 316 stainless steel. The ducts through which the liquid metal (typically sodium) flows are also composed of this 316 steel. In practice, difficulty has been experienced both with the cladding and the ducts. The stainless steel on being bombarded by neutrons, particularly where the neutron flux is epithermal (E>0.1 MeV), swells. In addition, the stainless steel does not have the necessary strength at the elevated temperatures, 500° C. and higher, at which the reactors of the type involved operate. The problem is particularly serious in the case of the cladding. On being heated by the fission reaction, the fuel in tne capsules expands and in addition gas is generated and exerts high pressure at the high temperatures within the capsules. The cladding is highly stressed. The stress exerted in the ducts is at a lower level both because the temperature of the ducts is lower than that of the cladding and also because the mechanical pressure to which the ducts are subjected is lower. The stainless steel of the cladding and of the ducts is subject to substantial creep which is accentuated by the neutron irradiation.
Various alloys have been considered in efforts to provide improved cladding and duct materials. Among the alloys studied have been gamma prime hardened austenitic superalloys such as those described in U.S. Pat. Nos., 3,199,978; 4,129,462; 4,172,742; 4,231,795; and 4,236,943. In addition to the metallurgical conditions described in the listed patents, some of these alloys have also been studied in a solution treated and cold worked condition, as described in copending application Ser. No. 248,121 filed on Mar. 27, 1981 which issued as U.S. Pat. No. 4,359,350 on Nov. 16, 1982. These gamma prime austenitics can generally be designed to have good swelling resistance, high strength and high stress rupture strength relative to austenitic alloy 316.
The post irradiation ductility of these alloys as a class has been found to be at, or near, zero depending on alloy composition, heat treatment, irradiation temperature and fluence. Exposing gamma prime austenitics to a high energy neutron (E>0.1 MeV) flux in the as cold worked condition, as described in U.S. Pat. No. 4,359,350, has provided some improvement in the post irradiation ductility. However, the post irradiation ductility still is a concern, and there exists a need for further improvement in this area.
BRIEF SUMMARY OF THE INVENTION
It has been found that the addition of about 0.05 to 0.5 weight percent of yttrium, hafnium, or scandium to precipitation hardening austenitics provides a significant improvement in the post irradiation ductility of these alloys. It has further been found that the swelling resistance of these alloys is also improved when yttrium or hafnium is added. It has also been found that the improvement in post irradiation ductility appears to be dependent upon the presence of silicon in the alloy, preferably in the range of about 0.5 to 1.5 weight percent. It is believed that lanthanum may be substituted for all or part of the yttrium, hafnium and scandium additions, in that it is also beleved to provide improvement in the swelling resistance and post irradiation ductility of these alloys.
Preferred alloys in accordance with the present invention fall within the following composition ranges:
about 7-17 weight percent chromium;
about 24-45 weight percent nickel;
about 2-3.8 weight percent titanium;
about 0.5-2.2 weight percent aluminum;
about 0.8-3.5 weight percent molybdenum;
about 0.5-1.5 weight percent silicon;
about 0.03-0.06 weight percent carbon;
and about 0.05-0.5 weight percent of an element selected from the group of yttrium, hafnium and scandium, alone or in combination with each other.
Preferably the balance of the alloy is essentially iron except for impurities. However, other elements such as boron and zirconium may also be added in small amounts. Manganese may be present at a level of up to about 2 weight percent.
While the observed improvements in post irradiation ductility have been observed in alloys in a solution treated and aged condition, it is believed that these improvements will also be produced in alloys exposed to irradiation in a cold worked condition, and in a cold worked and aged condition.
These and other aspects of the present invention will become more apparent upon review of the following detailed description of the present invention.
TABLE I______________________________________NOMINAL COMPOSITIONSAlloy Ni Cr Mo Si Mn Zr Ti Al C B Other*______________________________________Base 25 7.5 1.0 1.0 0.2 .05 3.3 1.7 .05 .005 --2 25 7.5 1.0 -- 0.2 .05 3.3 1.7 .05 .005 0.2 Sc6 25 7.5 1.0 1.0 0.2 .05 3.3 1.7 .05 .005 0.2 Sc3 25 7.5 1.0 -- 0.2 .05 3.3 1.7 .05 .005 0.2 Y7 25 7.5 1.0 1.0 0.2 .05 3.3 1.7 .05 .005 0.2 Y4 25 7.5 1.0 -- 0.2 .05 3.3 1.7 .05 .005 0.2 Hf8 25 7.5 1.0 1.0 0.2 .05 3.3 1.7 .05 .005 0.2______________________________________ Hf *Balance of all alloys is essentially iron, except for impurities
TABLE II______________________________________CHEMICAL ANALYSES AlloyElement Base 7 8______________________________________Ni 24.54 25.14 25.04Cr 7.72 7.58 7.57Mo 1.04 1.03 1.02Si .98 1.06 .96Mn .23 .21 .21Zr .054 .051 .056Ti 3.16 3.21 3.20Al 1.62 1.70 1.59C .050 .053 .056B .0047 .0063 .0054P* <.005 .005 <.005S* .003 .001 .003Cb* <.01 <.01 <.01Hf -- -- .35Y -- .091 --______________________________________ *incidental impurity
DETAILED DESCRIPTION OF THE INVENTION
In order to demonstrate the advantages of the present invention, alloys having the nominal compositions shown in Table I were melted. It will be noted upon review of Table I that a gamma prime hardening austenitic base composition was selected and then additions of about 0.2 weight percent scandium, yttrium or hafnium were made to the base composition while varying the silicon content of the base composition between about 1.0 weight percent and about zero (i.e., impurity levels). In this manner seven alloys having the nominal compositions shown in Table I were melted into ingots. While it is desired to hold the levels of the other alloying elements constant from ingot to ingot, normal ingot to ingot variability in chemistry did occur. Examples of the variability observed are indicated by the chemical analyses shown in Table II. This variability is not believed to have had a significant affect on the determination of the effect of additions of scandium, yttrium and hafnium, with and without silicon, on the swelling resistance and post irradiation ductility of the alloys studied.
The ingots representing the alloys shown in Table I were first hot worked to an intermediate size to improve the chemical homogeneity within the ingot and substantially remove the as cast microstructure of each ingot. After hot working, the intermediate size products were cold worked to final size in a series of steps having intermediate solution anneals between each cold working step.
For example, the Base, #7 and #8 alloy ingots were intially soaked for about 1 to 11/2 hours at about 1150° C. They were then press forged at about 1150° C. to a flat bar having a nominal thickness of about 5/8 inch. Subsequently, each ingot received a homogenization treatment which entailed soaking the ingot at about 1225° C. for about one hour followed by about a 2 hour soak at about 1275° C. and then furnace cooling. Intermediate product from each of these three ingots was then cold worked in steps to substantially final size. The reductions utilized in each step typically varied from about 25 to 45 percent. Intermediate solution anneals at about 1150° C. for about 3/4 hour followed by furnace cooling were performed between each cold working step. The last cold working step comprised about a 25% reduction.
After the last cold working step, material from each of the heats shown in Table I were solution treated and aged as follows:
1. Solution treating was performed by soaking at about 1050° C. for about 1/2 hour and was followed by air cooling.
2. Aging was then performed by soaking at about 800° C. for about 11 hours followed by air cooling. A secondary aging treatment was then performed by soaking at about 700° C. for about 8 hours followed by air cooling.
Samples of the fully fabricated and heat treated alloys were then irradiated in fast neutron fluxes to various fluences and at various temperatures. The addition of hafnium and yttrium to the base alloy were found to significantly improve swelling resistance as demonstrated in Table III. Scandium, however, had no significant affect on swelling resistance.
TABLE III______________________________________SWELLING CHARACTERISTICSIrrad-iation Neutron Fluence Percent Volume Expansion*Temp. × 10.sup.22 n (E >0.1 Base°C. MeV)/cm.sup.2 Alloy Alloy #7 Alloy #8______________________________________400 5.9 0.72 -0.49 -0.47427 6.8 1.29 -0.32 -0.33454 5.7 0.73 -- --482 6.7 0.86 -- --510 7.4 1.36 -- --538 7.4 2.23 0.91 --593 7.8 0.61 -0.20 -0.06650 7.7 0.41 -0.37 -0.44______________________________________ *Negative values indicate a volume contraction
Additional samples irradiated at selected temperatures and fluences indicated in Table III were characterized as to their post irradiation ductility. These ductility results are shown in Table IV.
TABLE IV__________________________________________________________________________POST IRRADIATION DUCTILITY AS MEASURED BY DISC BEND TESTING Percent Strain,Irradiation Test Base Alloy #2 Alloy #6 Alloy #3 Alloy #7 Alloy #4 Alloy #8Temp. °C. Temp. °C. Alloy (Sc no si) (Sc) (Y no si) (Y) (Hf no si) (Hf)__________________________________________________________________________454 564 0.7 0.2 -- -- -- 0.7 --482 592 -- 1.0* V.D.** 0.1 V.D.** -- V.D.**510 620 0.4 0.5 2.1 0.9 5.0 0.3 2.2538 648 0.3 0.5 1.2 0.3 1.1 0.5 0.8593 703 0.6 -- -- 0.3 -- -- --__________________________________________________________________________ *tested at 564° C. rather than 592° C. **V.D. = very ductile, i.e., ductility greater than 5%
The disc bend ductility test used to test these alloys is a specially designed microductility test in which an indentor is pushed through a thin disc-shaped sample of the test material. The strain, ε, or measure of ductility provided by this test has been correlated with tensile test results. The correlation between these two tests is accurate for low ductility materials. The discs are typically about 1/8 inch or 3 mm. in diameter and approximately 0.009-0.014 inch thick.
The ductility test results shown in Table IV indicate that a significant improvement in the gamma prime hardened base alloy post irradiation ductility is obtained by the addition of scandium, yttrium or hafnium to the base alloy composition. However, it is also indicated that where the alloy contains no significant quantity of silicon, these additions did not enhance ductility.
It is therefore believed that when about 0.05 to 0.5 weight percent of scandium, yttrium and/or hafnium is added to a gamma prime hardening austenitic alloy containing an effective amount of silicon the post irradiation ductility of the alloy should be enhanced. It is preferred that silicon be present at a level of about 0.5 to 1.5 weight percent. In addition it is believed that lanthanum may be substituted for all or part of the scandium, yttrium and hafnium.
It is also believed that the benefits of the present invention are also applicable to gamma prime hardening austenitics which are placed in pile in a cold worked and aged condition or a cold worked condition. Typical of the treatments that may be utilized are as follows:
TREATMENT I
1. Solution treat at about 950° to 1150° C.
2. Cold work 20-80%, preferably 30 to 60%
3. Age at one or more temperatures.
TREATMENT II
1. Solution treat at about 950° to 1150° C.
2. Cold work 10-60%, preferably 15 to 30%.
The present invention provides an improved precipitation strengthening austenitic superalloy for liquid metal fast breeder reactor ducts and fuel pin cladding.
While the invention has been described in connection with specific embodiments, it will be readily apparent to those skilled in the art that various changes in compositional limits and heat treatments can be made to suit arrangements without departing from the spirit and scope of the invention. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of purification by extraction of at least one substance to be isolated from a liquid medium.
2. The Prior Art
Many of the industrial methods of purification now practised are included in the following list, with their disadvantages in parentheses: salting-out (distillation of the agent modifying the solubility), precipitation (acid or base from displacement of the precipitating agent and distillation sometimes azeotropic), liquid/liquid extraction (sometimes with two expensive solvents, with regeneration and progressive loss of efficiency of the solvents), ionic flotation (long and costly), ion-exchange resins (difficult to apply in acid media) and electrolysis (not very efficient, high energy consumption).
In the special case of the production of pure or extra-pure phosphoric acid, if synthesis is excluded, this is now made principally by two methods: either by the "dry" method, with high energy consumption, using "ore-coke-silica" furnaces at more than 1000° C. followed by bubbling through H 2 O of the P 2 O 5 extracted from it; or by the "wet" method using attack by an acid, mainly sulphuric acid (whose evolution of heat is quite considerable), but also nitric acid (corrosive with release of noxious NOx), hydrochloric acid (very corrosive), or perchloric acid (danger of explosion), on phosphate ores given prior treatment (by calcination, crushing, screening) yielding a crude phosphoric acid solution. The Ca salts formed following the acid attack are removed by crystallisation of the sulphates (from 80° C. to 110° C.) or the nitrates (at a temperature <-5° C. and with a low filterability) or again by carrying out a liquid/liquid extraction of the phosphoric acid, leaving the calcium chlorides untouched. The crude acid solutions are then concentrated by evaporation (noxious vapours) up to a 40% or 50% P 2 O 5 content (crude solution, sometimes called "green" or "black" acid in the case of attack using sulphuric acid).
The wet method using sulphuric acid, which covers the majority of the world tonnage of economically valuable phosphates, then directs the green acid either to the production of phosphate salts (for example, of superphosphates and nitrogenous phosphates for fertilisers) or to purification leading to pure or extra-pure phosphoric acid.
The aim of the method according to the invention is to overcome the disadvantages, indicated in parentheses, of the aforesaid present industrial methods of purification.
Methods are also known for the purification of aqueous acid solutions, such as crude phosphoric acid solutions, in which a substance is introduced which, with the acid, forms a precipitate in the form of a phosphate. Known examples are the addition of urea to obtain urea phosphate crystals (Chemical Abstracts 84:152820 of DE-A-2511345), that of melamine to form melamine phosphate (Chemical Abstracts 10: 138052) and that of 1,4-dioxan to form an addition product (salt) of this substance and H 3 PO 4 (Chemical Abstracts of the Japanese patent application Kokai JP 51143597).
These methods turn out to be relatively complicated when it comes to separating the phosphoric acid from the salt or from the adduct formed. Use is generally made of nitric acid to displace the phosphoric acid and to form a nitrate of the precipitating substance. In other cases, through elution using an aqueous ammonia solution, ammonium phosphate is produced, isolating the substance used for the precipitation and thus enabling it to be recycled.
A Moroccan patent no 23439 is also known, in which the phosphoric acid is subjected to the action of an MSA compound of unspecified composition which puts the phosphoric acid into a form which can be purified by simple filtration. The phosphoric acid and the MSA compound are then recovered separately in regeneration reactors. The regeneration step is not indicated in this document either.
In Cellulose, Lignin and Paper-23, 1957, column 18606, a description is given of the precipitation, using aniline, of aniline-H 3 PO 4 from a solution containing dissolved phosphates. Once again this adduct is treated by NH 3 in order to produce ammonium phosphate and the aniline can be extracted and purified from the reaction medium only after several operations, including a purification with Ca(OH) 2 and an extraction with benzene.
In Chemical Abstracts, vol 60, column 6515, a description is given of a method for recovering phosphoric acid from a solution containing phosphoric acid or phosphates by treatment with an aromatic amine, particularly aniline or p-toluidine, by heating to 102° C. This gives an amine phosphate of high purity. However, this reference does not explain how to recover pure phosphoric acid from the amine phosphate.
All these methods describe an operation which is generally well known, that of a joint precipitation of the substance added to the liquid medium to be treated and of a substance which occurs in the treated liquid medium. These methods are then used to produce a derivative (a salt, for example) of the acid contained in the liquid medium or of the precipitating agent, without managing to produce this substance (the acid) in the pure state, and simultaneously to recover the precipitating agent in a recyclable manner. The formation of new salts necessitates the introduction of new substances, such as HNO 3 or NH 3 , into the liquid medium.
The aim of the present invention is to solve the problems of cost, pollution and energy consumption associated with most of the methods for separating substances from a liquid medium.
SUMMARY OF THE INVENTION
These problems are solved by a method of purification by extraction of at least one substance to be isolated from a liquid medium, comprising
an addition to the liquid medium of an organic compound, which can be entrained by a vapour and which has a molecule of acidic-basic character in the Lewis sense due to at least one atom of N, O and/or S forming one or more active sites provided with a free electron pair, the free electron pair or pairs being in resonance with at least one other pair carried by the molecule, this compound possibly carrying as well at least one hydrogen atom subjected to an electronegativity coming from one of the said active sites, this addition being carried out in a quantity sufficient to give rise to an equilibrium reaction product between the organic compound and the said at least one substance to be isolated, a reaction in which the difference in pKa between the compound and substance lies between 0.1 and 5, and sufficient to cause a precipitation of this equilibrium reaction product in the form of a precipitate,
an isolation by filtration of the precipitate and removal of a filtrate,
an entrainment by the aforesaid vapour of the above-mentioned organic compound from the precipitate, and
a yield in purified and isolated form of the said at least one substance to be isolated.
According to the invention, therefore, a substance of acidic-basic character in the Lewis sense is used, a substance which is capable with acids of forming an equilibrium reaction product using its electron pair or pairs and which, possibly in addition, can react in a basic medium. In effect, this compound may with advantage have labile hydrogen atoms, which are subjected to an electronegativity coming from one of the said active sites, enabling protons to be released. The pKa difference between the reagents giving rise to the above-mentioned precipitate characterises an equilibrium reaction. Outside the range pKa =0.1 to 5, the reaction between the organic compound and the substance to be isolated either does not take place or it takes place to the point where a complete reaction is achieved.
In order to allow good entrainment by a vapour, in conformity with the invention, the organic compound is with advantage not miscible with this vapour, or is only partially so. With this condition, during the entrainment, an increasingly vigorous volatilisation of the organic compound takes place, which tries to respect the equilibrium between the partial pressures of the vapour and of the entrained molecule. This lack of equilibrium has the effect, firstly, of fixing all that remains of the organic compound according to the invention which has not reacted with the substance to be isolated so as to re-establish equilibrium between the product subjected to entrainment by the vapour and the substance to be isolated, and secondly of completely isolating the required substance, while all the organic compound has been entrained. Entrainment by vapour is a well-known technique (see for example, Encyclopedia Britannica, 1970 edition, vol. 7, p. 497, Steam Distillation).
With advantage, the organic compound according to the invention is an aromatic amine, such as aniline, p-toluidine or 3-methyl-2-naphthylamine. It is of course also possible to use derivatives or isomers of these substances. Amongst these, for example, may be quoted their salts, such as the phosphate, sulphate or chloride of aniline, or lower alkyl derivatives, for example methylaniline, or nitrogenous derivatives, for example nitroaniline. Other substances could also satisfy the criteria set out in the method. These are, for example, pyrrole, thiophen, o-cresol, C 7 H 8 O (particularly m-cresol), C 6 H 10 ClNH 2 (particularly monochloro-2-methyl-2-pentene), C 5 H 10 S (particularly ethiothiol-l-propene) or C 4 H 6 Cl 2 O 2 (particularly ethyl dichloroacetate), as well as their derivatives or isomers.
It should be pointed out that it has long been known that aniline easily becomes volatile in the presence of steam (The Merck Index, 10th edition, 1983, no 681).
According to an advantageous form of the method according to the invention, the steam distillation stage comprises an injection of steam over the precipitate in the state of a filter cake, and an entrainment by the injected steam of the organic compound. The filter cake, which occurs in a form which is very stable and perfectly capable of being stored under ambient conditions, may thus be subjected either directly, or subsequently and/or elsewhere, to steam distillation without prior treatment. In the field of H 3 PO 4 purification, this makes it possible to avoid the great problems of storage and transport of the unstable "green" acid of the current technique.
Depending on the nature of the organic compound to be entrained, a vapour of a predetermined substance will be chosen. For example, steam in the case of aniline, benzene vapour in the case of
pyrrole or thiophen, or ether vapour for ##STR1##
It is possible to provide for modes of entrainment by vapour other than that by injection, particularly, in the case of steam distillation, by using a mixture of the precipitate and liquid water. The water is then heated to boiling point and this entrains with it the organic compound to be entrained.
A preferred form of the method according to the invention comprises the addition of the organic compound in a crude state and also, following the stage of entrainment by vapour, a separation of the organic compound in the pure state from the liquefied entrainment vapour, and possibly a recycling of this pure organic compound or of the organic compound with the liquefied entrainment vapour in the addition stage. In this way, it is therefore possible to carry out a simultaneous purification of the agent used to extract in the purified state a substance contained in a liquid medium. The impurities both in the aforesaid crude organic compound and in the liquid medium to be treated are recovered in the filtrate obtained during the filtration of the precipitate.
According to an improved form of the method according to the invention, it comprises:
a first addition of the said organic compound to the liquid medium in a quantity appropriate for obtaining a modification of the solubility in the medium of one or more impurities present by causing a precipitation or coprecipitation of the said impurities,
a separation of the precipitated or coprecipitated impurity or impurities,
a second addition to the remaining liquid medium of the said organic compound which, added to the first addition, reaches the said sufficient quantity to cause a precipitation of the said equilibrium reaction product. In such a case, the organic compound acting as a modifier of solubility is capable of inducing, before the precipitation in which it participates itself, a precipitation of one or more impurities. In the case of the purification of phosphoric acid, a first addition of aniline can in this way modify the solubility by modification of the pH and can produce a precipitation of calcium sulphate in the pure state.
A stage of solubility modification must be understood in the present invention to cover not only a modification of the pH but also, for example, a change of solvent or any other technique of a similar type known to one skilled in the art.
Other characteristics of the invention are indicated in the claims which follow.
Other details and special features of the invention will also emerge from the description given below, as a non-limiting example, with reference to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 represents an embodiment of a unit for modifying the solubility of the liquid to be treated, which may be used in the method according to the invention.
FIG. 2 represents an embodiment of the precipitation unit which may be used in the method according to the invention.
FIG. 3 represents an embodiment of the regeneration unit which may be used in the method according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In the various drawings, identical or similar elements are denoted by the same reference numbers.
In the embodiments illustrated, the method according to the invention is explained by basing it on a particular mode of execution, that of the production and purification of phosphoric acid. An equivalent method could be applied to other acids, such as sulphuric acid, or again to mother liquors arising from their production.
It is also possible, given the acidic-basic character of the organic compound introduced in the method, to use a similar method for the purification of media with a less pronounced acidic or basic character, particularly for the softening of tap water or the desalination of seawater. Another area of application consists of the treatment of discharges from industries such as paper-making and sugar refining or from factories making or treating dyestuffs; the substances capable of being extracted from their effluents by the method described are, for example, benzoic, carboxylic or acetic acids, their salts, and compounds rich in metallic ions (Cr 3 for example) or other organic compounds resistant to oxidation processes, such as benzene, fatty acids and organic dyestuffs.
In the unit for changing solubility 1 illustrated in FIG. 1, a crude solution of phosphoric acid 3 resulting for example from attacking the ore with sulphuric acid (the wet method) is introduced into a receptacle 4 through the duct 2. This solution is diluted to a concentration of approximately 20 to 25% H 3 PO 4 , for example by adding, through 8, mother liquors 7 resulting from the method. An organic compound 5 according to the invention, inexpensive crude aniline for example, is introduced through 6 into the receptacle 4. With advantage, the aniline is dispersed in the form of an emulsion/aqueous solution. The aniline introduced, as a weak base, induces in the acid medium a change in pH to bring it within a range lying between 1.3 and 5, preferably between 2.0 and 3.5, which, in the present example, produces, without any input of energy, a precipitation of calcium sulphate in a form which can be filtered much more easily than in current methods. Unlike the methods according to the current state of the art, where carbonates are added to the "green acid", non-hydrated sulphates are obtained here with very low concentrations of elements such as U, Cs, Cd, As, F, etc . . . which remain in the filtrate. The acid solution treated in the receptacle 4 is filtered in the filter 9. The calcium sulphate precipitate is recovered in 10 to be exploited for example in the plaster of Paris industry. The filtrate 11 contains a solution of H 3 PO 4 , aniline and impurities other than those already filtered, and it is discharged through 12 from the filter 9.
The liquid 11' (the filtrate 11 of unit 1) is then passed into the precipitation unit 13 represented in FIG. 2, and it is introduced into the receptacle 14 at a phosphoric acid concentration advantageously lying between 12% and 40%. Also introduced through 16, preferably in dispersed form, is a complementary quantity of crude aniline 15 so that the ratio of the weights of aniline and acid lies between 0.5 and 1.5, preferably 1.2. This operation is with advantage carried out between 10° C. and 80° C. Preferably, agitation is provided for in the receptacle 14 by an ordinary agitator, not represented. With advantage, the turbulent state obtained will have a coefficient N 3 D 2 lying between 2 and 4, N being the speed in revolutions per second and D the diameter in metres of the agitator. This agitation is provided in order to allow adequate dispersion of the aniline in the liquid medium and to avoid an accumulation of precipitates at the point where addition takes place.
It is obvious that these data are valid for the case of the addition of aniline to a phosphoric acid solution and that they may be modified depending on the substance to be purified and the organic compound used for this purpose.
Within a period of 5 to 30 minutes, a precipitate of very easily filterable aniline phosphate C 6 H 5 NH 2 .H 3 PO 4 is formed in the receptacle 14. The mixture formed is transferred to the filter 17, which may be any type of filter suitable for this operation, for example a filter press. The precipitate formed is removed through 18 from the filter 17 in the form of a filter cake 19 consisting in the present example of crystals of aniline phosphate. This precipitate might possibly at this stage be washed by a saturated solution of aniline phosphate.
Unlike the unstable intermediate solutions obtained in the methods of the prior art, which give rise to considerable costs and the trouble of cleaning the storage tanks and cargo holds or difficulties in titration because of suspensions and precipitations subsequent to the filtration, the aniline phosphate filter cake is stable at room temperature. It can easily be stored in order to extract the phosphoric acid from it, later or elsewhere, simply by using steam, as will be described later.
A filtrate, known as the mother liquor, is obtained through 20. It may be partly recycled in the receptacle 14, through the intermediary of the duct 21', in order to adjust the P 2 O 5 . concentration of the acid to be treated, and in the receptacle 4 through the intermediary of the duct 8 and the reservoir 7, already represented in FIG. 1 (reservoir 7' in FIG. 2). These multiple recyclings also make it possible to minimise the losses of P 2 O 5 between the crude solution and the filter cake 19. The non-recycled mother liquors 38 contain only quantities of P 2 O 5 not exceeding 20% and small quantities of sulphuric acid and aniline, and they also contain water and impurities such as F, Cd, As, etc . . . The non-recycled mother liquors 38 are discharged from unit 13 through 21, from where they may possibly be treated as described below. The removal of all the undesirable elements by the filtrate 38, so as to keep only the purified phosphoric acid and the purified aniline in the filter cake, makes it possible to consider exploiting phosphate deposits hitherto not exploited because of too high a concentration of polluting elements, while at the same time obtaining pure gypsum.
FIG. 3 illustrates a unit 22 for entrainment by vapour according to the invention, in the present case a steam distillation unit.
This unit comprises a receptacle 24 into which, via 23, the filter cake 19' (cake 19 of the precipitation unit 13) is introduced. Simultaneously, water 39 is introduced in the form of steam through 25 into the receptacle 24. In the example illustrated, hydrolysis of the filtrate is envisaged by injection into the filter cake of approximately 1 to 2 kg of steam per kg of cake. The latter will advantageously have a temperature lying between 40° C. and 200° C., preferably between 40° C. and 110° C. The steam distillation will therefore preferably be carried out under vacuum. The acid, obtained through 33, is filtered in the receptacle 34, from which pure phosphoric acid is extracted through 35. The said acid no longer requires concentrating, since the concentration can be adjusted directly through the ratio used between the weights of the steam and the P 2 O 5 , of the cake. The cake 36, consisting of the possibly non-hydrolysed fraction in 24, is recycled to be subjected once again to the action of the steam.
From the receptacle 24, the H 2 O and aniline vapour is removed through 26 and transferred for example to a decanting device 29, where the two components, which are almost non-miscible in the liquid state, are easily separated. During this transfer, it is possible to envisage passage through a heat recuperator 30, enabling heat to be recovered for the water 39 entering the unit 22. The main input of heat to the water entering the unit 22, or the only input as the case may be, is provided elsewhere by means of a heating device 32.
Through the duct 40, the water from the decanter 29 may be recycled in steam distillation while, through 31, pure aniline may be recycled in 5 (FIG. 1) and/or in 15 (FIG. 2), or may be used in other industrial areas. The method thus involves a simultaneous double purification, that of the phosphoric acid and that of the aniline.
In a variant, between the recovery of the filter cake 19 through 18 (see FIG. 2) and its introduction through 23 into the receptacle 24 (cake 19' in FIG. 3), it is also possible to envisage the introduction of the cake 19 into a reactor not represented, in which the cake is mixed with an alkaline or nitrogenous compound, for example KOH, NH 3 or urea. The aniline is then displaced from its precipitate in favour of a phosphate of an alkali metal, of ammonium or of urea, for example. This product is introduced into the receptacle 24, the aniline is entrained in the steam as described above and the required phosphate solution is recovered through 27 in the receptacle 28.
The pure phosphoric acid obtained in 37 may also be increased in quality by a standard treatment of crystallisation and decolourising, for example with hydrogen peroxide and activated carbon, which removes organic matter from it, particularly any remaining traces of aniline if these are undesirable in the applications of the phosphoric acid.
It should be noted that the passage into a unit for changing solubility 1, such as that illustrated in FIG. 1, is not necessarily essential in every case. It is possible, for example, to imagine having to treat a "green acid", i.e. a crude acid already partially purified, particularly from sulphates, by standard methods, and having a P 2 O 5 content from 40 to 50%. In this case, the solution to be treated 11', i.e. the green acid in this case, is introduced directly into the receptacle 14 of the precipitation unit illustrated in FIG. 2.
As was said above, the method illustrated is given as an example with aniline and phosphoric acid. It is possible to provide for the purification and separation of other substances and, for example, to take advantage of this in order to exploit certain substances contained in a liquid medium.
We could take, once again as a non-limiting example, the mother liquors 38 recovered through 21 at the output from the unit in FIG. 2.
It is possible to envisage making this liquid medium pass through a new stage corresponding to those described previously. In the unit illustrated in FIG. 1, the solution 3 therefore consists of these mother liquors containing impurities such as F, Cd, As, etc. . . . and other exploitable components. This solution is introduced into the receptacle 4 and its pH is modified by an input of aniline 5, possibly crude, in such a way as to achieve, in the present case, a range from 2.4 to 6.5, preferably from 3.6 to 6.5. At this pH the filtrate is cleared of impurities in the form of a precipitate which is removed to 10 by filtration in the filter 9. The filtrate 11 is then introduced into the precipitation unit illustrated in FIG. 2 (medium 11'). The precipitate is filtered in 17 in the form of a filter cake 19, and it is then subjected to treatment in a steam distillation unit as illustrated in FIG. 3. There, the steam entrains purified aniline, which is separated for example by decanting in 29, while a concentrate of impurities is recovered in 28 having a volume considerably smaller, for the same initial filtrate, than the concentrates obtained by current methods.
In a variant, this same technique may be used to extract, this time in successive stages, different groups of impurities from the mother liquors 38 recovered through 21 at the output from the unit in FIG. 2. For that purpose, the method operates over the ranges of pH and temperature, making it possible, for example, to isolate first fluorine, cadmium and arsenic, then iron, magnesium and aluminium and finally radioactive heavy metals and rare earths.
The present invention will now be explained in a more detailed manner using non-limiting examples of its execution.
EXAMPLE 1
Into an agitated reactor, 500 ml of previously obtained phosphoric acid are introduced, the said acid containing 10% of P 2 O 5 , and 30 g of ore (33% P 2 O 5 ) are added to it. The reaction occurs between 35° C. and 40° C. for 1/2 hour; 7 g of the non-attacked dry residue are separated using a filter; 480 ml of filtrate are reintroduced into another agitated reactor, where 25 g of H 2 SO 4 with a concentration higher than 99% are added. The reaction takes place at a temperature between 35° C. and 40° C. for 1/2 hour, the hydrated calcium sulphate formed is separated by a simple filtration; the weight of the wet cake is 92 g and has a purity higher than 96%; the volume of filtrate is 320.5 ml and the cake is washed with 180 ml of H 2 O.
In another reactor, 67.83 ml of the filtrate and 25 g of the washing water are mixed with 20 g of aniline; the reaction takes place in 15 minutes at a temperature of 20° C.; the pulp formed is passed through a filter where 35 g of wet aniline phosphate cake with a purity of 99% and 71.75 g of filtrate are recovered.
The phosphoric acid obtained after separation of the aniline by entrainment is 10.78 g with 54% P 2 O 5 .
The analysis is as follows:
______________________________________ P.sub.2 O.sub.5 54% Ca <0.05 F <0.05 SO.sub.4 1.5% Cd <1 ppm As <1.5 ppm Fe <10 ppm Al 41.3 ppm Mg 80 ppm K 7 ppm Na <10 ppm______________________________________
The cake and the filtrate are then respectively subjected to operations like those described in Example 2 and in Example 5 below.
EXAMPLE 2
Use is made of 100 g of crude phosphoric acid solution obtained by an ordinary wet method and having a P 2 O 5 , content of 47.7% (green acid). This solution corresponds to the following analysis:
______________________________________Concentrations in μg/ml (ppm):______________________________________As: 23 Mg: 3050 K: 728Cu: 132 Na: 803 Si: 239Al: 491 Pb: 1 U: 92Ca: 96 Cd: 2 F.sup.- : 1260Fe: 2750 Ni: 12 SO.sub.4.sup.= : 33400Concentration in μg/ml (ppb):Hg: 5______________________________________
It is diluted in the receptacle 14 of unit 13 (FIG. 2) with 238 g water, to take its P 2 O 5 concentration to 14.1%. To this is then added 74 g of aniline. After precipitation, filtering and washing the precipitate (cake) of "aniline.H 3 PO 4 ", 76 g (dry weight) of the cake are removed to 19 and 162.4 g of filtrate are removed to 38, the latter intended particularly to follow subsequent operations leading to exploitation. The cake is then introduced into the receptacle 24 of the unit 22 (FIG. 3) where the action of the steam on the cake with a weight ratio of 2:1 releases phosphoric acid (into 28), and this corresponds to the following analysis, characteristic of a purified solution with a P 2 O 5 content of 41.5%:
Concentrations in μg/ml:
______________________________________Concentrations in μg/ml:______________________________________As: <0.5 Mg: 59.6 K: <3Cu: 1.4 Na: 6.3 Si: 5.2Al: 4.6 Pb: <1 U: <2Ca: 36 Cd: 1.6 F.sup.- : 13.2Fe: 32 Ni: 1.3 SO.sub.4.sup.= : (32)Concentration in ng/ml (ppb):Hg: <5______________________________________
EXAMPLE 3
Into an agitated reactor, 0.5 liter of phosphoric acid obtained by a wet method with sulphuric acid is introduced, containing 55% of P 2 O 5 , 67 ppm of Cd and 133 ppm of U. After dilution, 520 g of aniline are added to this. The precipitate formed is filtered and washed. After hydrolysis of the precipitate by steam and entrainment of the aniline by this steam, the recovered phosphoric acid displays a 98.5% rate of removal of impurities: it contains less than 1 ppm of Cd and less than 2 ppm of U.
EXAMPLE 4
Into an agitated reactor, 0.35 liter of phosphoric acid obtained by a wet sulphuric method is introduced, containing 32.4% of P 2 O 5 , 40 ppm of Cd and 78 ppm of U. 260 g of aniline are added to this. A precipitate is formed and is washed and filtered. After entrainment by aniline vapour, the remaining phosphoric acid contains less than 0.5 ppm of Cd and less than 1 ppm of U.
EXAMPLE 5
Into an agitated reactor, 500 g of aqueous filtrate obtained in 38 of unit 13 in FIG. 2 are introduced. It corresponds to the following analysis: 7% of P 2 O 5 , 0.1% of Fe 2 O 3 and 0.12% of Al 2 O 3 , together with 0.03% of CaO. This is mixed with 85 g of aniline at a pH >5 at 102° C. A precipitate of impurities with a weight of 7.5 g is formed and is separated for filtration, the filtrate then being cooled to 10° C. to crystallise 130 g of aniline phosphate with a purity higher than 99%. The cake is treated according to FIG. 3.
It should be understood that the present invention is in no way limited to the modes of execution described above and that many modifications could be made to it without going outside the scope of the claims.
It would be possible, for example, to imagine that the method could also use, during its various successive stages, not just the same organic compound in every case, but different organic compounds as long as they all conform to the invention. | 4y
|
BACKGROUND OF THE INVENTION
This invention relates generally to MIS (Metal-Insulator-Semiconductor) type integrated circuit devices, and more particularly to an improved MIS type integrated circuit device in which a semiconductor substrate is supplied with a bias voltage which increases the threshhold voltage of MIS type transistors included in the integrated circuit (hereinbelow referred to as a back-gate bias).
Since positive charges tend to be accumulated in a silicon oxide film used as a gate insulating film in MIS type integrated circuit devices, the semiconductor surface just beneath the gate insulating film of an N-channel MIS type transistor is easily converted to N type. Therefore, an N-channel MIS type transistor inevitably becomes the depletion type, even if the gate voltage is maintained at zero volts. MIS type transistors of the enhancement type needed for digital IC applications can be obtained by the application of a back-gate bias to the semiconductor substrate. With the back-gate bias applied to the semiconductor substrate in an integrated circuit device incorporating MIS type transistors, both the threshhold voltage (hereinafter abbreviated as VT1) of the MIS type transistor in the circuit and the threshhold voltage (hereinafter abbreviated as VT2) of a parasitic transistor to be formed between adjacent diffused regions in the semiconductor substrate can be made higher than that which can be obtained with the semiconductor substrate grounded, thereby widening the operating range of the circuit.
Suppose now that such an MIS type integrated circuit device incorporating N-channel MIS type transistors is operated with the back-gate bias applied to the P type semiconductor substrate and used with the substrate in an unbiased condition as a result of a delay in the application of the back-gate bias voltage at the moment the power supply is applied to the circuit of the device. This causes positive charges to leak from P-N junctions and channel portions in the circuit to the substrate. Since the charges flow toward grounded N type regions through the P-N junctions formed between the substrate and the grounded N type regions, the polarity of the potential of the substrate will become that of the circuit power supply potential for the presence of the voltage vs. current characteristics of the P-N junctions to reach a value of the order of for example, +0.5 volts. Because of this phenomenon, VT 2 is lowered further than expected in a case in which the substrate and the grounded region are equipotential, thus resulting in degradation in electrical isolation between transistors. Consequently, current flows in portions of the integrated circuit which should be essentially isolated electrically, and the circuit current abnormally increases, which may affect the life span of the integrated circuit.
Power supply devices conventionally used are so contrived that the back-gate bias can be applied to the substrate prior to the application of a voltage to the circuit. Such devices are invariably expensive as compared to ordinary devices. The same problem mentioned above has also arisen in cases in which an MIS type integrated circuit device is used under a condition of power supply application with the substrate kept released from the back-gate bias.
It is consequently an object of this invention to provide an MIS type integrated circuit device, in which the substrate potential does not increase toward the potential of the circuit power supply when the semiconductor substrate is in an electrically floating state and the possibility of an excessive increase in current flowing in the circuit is eliminated.
SUMMARY OF THE INVENTION
An MIS type integrated circuit device according to this invention comprises a semiconductor substrate of a first conductivity type connected through switching means to a first power supply for a back-gate bias, a grounded first region of a second opposite conductivity type extending inwardly from a major surface of the substrate, a clamp means connected between the first region and the substrate for clamping the substrate potential at a predetermined value, and a second region of the opposite conductivity type also extending inwardly from the major surface of the substrate and connected to an additional second power supply opposite in polarity to said first power supply, whereby the clamp means clamps the potential of the semiconductor substrate at a potential between +0.1 volts and -0.1 volts when the switching means is open.
While either an MIS type transistor of the depletion mode or a resistance element may be employed as the clamp means, as will be explained later by reference to specific embodiments of this invention, the use of a depletion type transistor is advantageous compared to the resistance means in that current flowing in the clamp element becomes extremely small and hence power consumption is minimized, under normal operation -- that is, when the back-gate bias, the ground potential and a voltage opposite in polarity to the back-gate bias are applied to the substrate, the first region, and the second region respectively.
According to the MIS type integrated circuit device of this invention, even when the substrate is in the unbiased condition, the differential potential between the substrate and the grounded first region is maintained below 0.1 volts by the clamp means and hence the potential of the substrate is substantially equal to the ground potential.
Therefore, VT2 for electrical isolation between adjacent transistors can be maintained sufficiently high and the possibility of an excessive current flowing into the integrated circuit or the life of the circuit being adversely affected can be eliminated.
Furthermore, it is not necessary to use the expensive power supply device mentioned above so contrived as to apply a backgate bias to the substrate prior to application of a voltage of the circuit power supply.
BRIEF DESCRIPTION OF THE DRAWINGS
For a better understanding of the principles of this invention, a detailed description of various embodiments will be given in conjunction with the accompanying drawings, in which:
FIG. 1 is a schematic cross-sectional view of an MIS type integrated circuit device according to a first embodiment of this invention;
FIG. 2 is an equivalent circuit diagram of the device shown in FIG. 1;
FIG. 3 shows the threshhold voltages of the MIS type transistors as a function of semiconductor substrate voltage;
FIGS. 4 (A), (B) and (C) show diagrams illustrating the current vs. voltage characteristic curves of a P-N junction, a MIS type transistor of depletion mode and a resistance element, respectively.
FIG. 5 is a schematic cross-sectional view of an MIS type integrated circuit device according to another embodiment of this invention; and
FIG. 6 is an equivalent circuit diagram of the device shown in FIG. 5.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a highly doped semiconductor regions 2 to 8 of N type and electrically isolated from one another are formed on a major surface of a P type semiconductor substrate 1 by a conventional technique such as selective impurity diffusion.
Silicon oxide films 9, 10, 11, and 12 that serve as the gate insulating films of MIS type transistors are respectively formed on the major surface of the substrate 1 between regions 2 and 3, 4 and 5, 5 and 6, and between 7 and 8. On these silicon oxide films the gate electrodes 13 through 16 are formed respectively. A MIS type transistor Q1 is composed of the N-type regions 2 and 3 and the gate electrode 13. In the same manner, transistors Q3, Q4, and Q5 are formed respectively by the regions 4, 5 and the gate electrode 14; by the regions 5, 6 and the gate electrode 15; and by the regions 7, 8 and the gate electrode 16. Further, thick silicon layers 18 and 19 are formed respectively between the regions 3 and 4 -- that is, between the transistors Q1 and Q3, and between the regions 6 and 7 -- that is, between the transistors Q4 and Q5, to achieve isolation between transistors. The thick silicon oxide layer 17 is formed as a protective film on the remaining part of the semiconductor surface. A metallic layer 21 is provided on the silicon oxide layer 18. A parasitic transistor Q2 is formed by the metallic layer 21, the regions 3 and 4, and the oxide film 18. A metallic layer 20 is also provided on the protective film 17.
The structure shown in FIG. 1 may be represented by an equivalent circuit shown in FIG. 2. As illustrated, the PN junctions formed by the P-type substrate 1 and the N-type regions 2 through 8 are represented by the diodes D1 through D6, respectively. The drain region 4 of the transistor Q3 is connected to a positive power supply 25 and at the same time, to the metallic layer 21, thereby forming the parasitic transistor Q2 as mentioned previously. The source regions 3 and 6 of the transistors Q1 and Q4 are both connected to the ground terminal 26 to become the grounded regions, and the substrate 1 is connected via a switch 28 to a power supply 27 for a negative back-gate bias.
In this embodiment, the depletion mode N-channel transistor Q5 is connected as a clamp means between the grounded regions, 3 and 6, and the substrate. Thus, the drain region 7 of the transistor Q5 is connected to the ground terminal 26 and both the source region 8 and the gate electrode 16 are connected to the substrate 1. It is noted that the transistor Q5 is fabricated simultaneously with the other transistors Q1, Q3, and Q4. In this case, the transistor Q5 will operate in the depletion made, since the gate insulating film 12 thereof is a silicon oxide film and the source region 8 is connected to the substrate 1.
All of the transistors Q1, Q3, and Q4 will be operated in the enhancement mode by a back-gate bias voltage via the switch 28. Each of the transistors Q1, Q3, Q4, and Q5 has a thin gate oxide film and the threshhold voltage VT1. While, the oxide film of the part corresponding to the gate of the parasitic transistor Q2 is thick and its threshhold voltage is expressed as VT2.
Now operation of the circuit of FIG. 2 will be analyzed with further reference to FIGS. 3 and 4. FIG. 3 illustrates variation of the threshhold voltage VT as a function of the substrate voltage VS. The relationship between VT and VS is given by
VT = K1 √ -VS + 2 φ F + K2 (1)
in equation (1), φ F denotes the Fermi-level of the substrate, and K1 and K2 are the constants mainly determined by the gate oxide film conditions. Therefore, the linear characteristics depicted in FIG. 3 can be obtained for VT and VS by taking VT and √ -VS + 2 φ F as the ordinate and the abscissa, respectively. Under normal operation, the switch 28 is closed so that the device is operated with a back-gate bias applied to the semiconductor substrate 1. Under this condition, which corresponds to the point D in FIG. 3, VT1 takes a low positive voltage and VT2 takes a positive voltage higher than the power supply voltage and hence no current flows in the parasitic MIS type transistor Q2. Assume now that the semiconductor substrate 1 is held at ground potential. This causes both VT1 and VT2 to decrease so that VT1 takes a negative voltage value as shown at point C in FIG. 3. In cases where the switch 28 is open and the transistor Q5 (the clamp means according to this invention) is not connected between the ground terminal 26 and the semiconductor substrate 1, a positive charge that has leaked to the substrate 1 from the high potential part within the semiconductor circuit via the P-N junctions. (D1, D3, and D4) and the MIS transistors (Q1, Q3, and Q4) will flow through the P-N junctions D2 and D5 to the ground terminal 26 which is the lowest potential. The potential of the substrate 1 in this case takes a value between +0.4 and +0.6 volts as shown by the voltage vs. current characteristic of the P-N junction shown at FIG. 4A, VT1 and VT2 taking values in the vicinity of point A on the abscissa of FIG. 3. It shows a further decrease in the values of VT1 and VT2. In this case, VT2 is lowered considerably as compared to the power supply voltage and the electrical resistance of the isolated part Q2 decreases, with the result that an excessive current flows into the integrated circuit.
The transistor Q5 of the depletion type is used as the clamp means according to this invention. Therefore, as shown in the voltage vs. current characteristic of the element Q5 of FIG. 4B, the drain current flows in spite of a slight increase in potential of the substrate 1 and an increase in the substrate potential is suppressed at a sufficiently low value on the order of less than +0.1 volt. In this case, the ground terminal 26 and the substrate 1 become almost equipotential, VT1 and VT2 take values in the vicinity of point B which is close to point C on the abscissa in FIG. 3, with the result that an abnormal current flowing into the integrated circuit is restricted to a value close to that which would be obtained if the substrate 1 were connected to the ground terminal. Accordingly, even when the substrate 1 is freed from the back-gate bias by the switch 28, the electrical resistance of the electrically isolating region Q2 is maintained at a considerably higher value. Therefore, the possibility of an excessive current flowing into the integrated circuit is eliminated.
It has been assumed in the foregoing embodiment that the element forming the clamp means is a depletion type transistor, but a resistance element may be substituted of the transistor. An embodiment for this type is shown in FIG. 5 using the reference numerals as in FIG. 1 to identify like components. In this embodiment, it can be seen that a resistance element 29 consisting of an N-type region is formed on the surface of the substrate 1 with one end connected to the ground terminal 26 and the other end connected to the substrate. The reference numeral 30 denotes an insulating protective film formed on the resistance element 29. An equivalent circuit of this device is shown in FIG. 6 which is similar to that shown in FIG. 2, wherein the resistance element 29 is represented by R1. The voltage vs. current characteristic of the resistance element 29 is shown at FIG. 4C. Since the previously mentioned leakage current with the substrate released is extremely small and current flows even in the case of a nominal potential difference on account of the resistance element, the substrate potential can be suppressed below about +0.1 volt in the same manner as mentioned previously.
In the device of FIG. 1 or FIG. 5, when the power supply 25 is +12 volts, the power supply 27 for the back-gate bias is -5 volts and the switch 28 is opened, the current flowing into the integrated circuit is 45 mA when the clamp means Q5 or 29 is not present. In contrast, it is 33 mA under the same conditions when the clamp transistor Q5 is employed according to this invention, the channel being 1,500 μ in width and 10 μ in length. The current is 34 mA in the case of employment of the resistance element 29 having a resistive value of 1 KΩ, under the same conditions.
In cases where the depletion type transistor Q5 is used with a negative potential applied to the substrate under normal operation, the backward current barely flows in the transistor Q5 as shown at FIG. 4B and power dissipation of this portion is only nominal, but current proportional to the back-gate bias applied to the substrate flows as indicated at FIG. 4C when the resistance element 29 is employed. Therefore, use of the resistance element 29 slightly increases the power dissipation, as compared to the use of the depletion type transistor Q5.
While the foregoing descriptions are concerned with integrated circuit devices of the structure including N-channel MIS type transistors, this invention can be applied to an integrated circuit device comprising P-channel MIS type transistors. In the latter case, a depletion type transistor must be also used as the clamp means. It has been publicly known that, in order to make a P-channel MIS type transistor used as a clamp means operate as a depletion type transistor, boron is injected into a channel region just beneath a gate insulating film by the ion implantation process so as to form a P-type region with a low impurity concentration. As a matter of course, the application of a positive voltage as a back-gate bias and a negative voltage as a circuit power supply voltage is needed in this case. Therefore, the substrate potential is suppressed below about -0.1 volt when the substrate is free from the back-gate bias.
Although both embodiments described above are concerned with the formation of the clamp means within the semiconductor substrate of an integrated circuit device, the structural modification of connecting an independently prepared clamp element across the ground terminal 26 and the semiconductor substrate could be made without departing from the essential scope of the present invention.
It will thus be appreciated that variations and modifications of the embodiments of the invention herein specifically described may be made by those skilled in the art to which the present invention pertains, all without departing from the spirit and scope of the invention. | 4y
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This is a continuation of U.S. patent application Ser. No. 07/584,771, filed Sep. 19, 1990, now abandoned which is a continuation-in-part of Ser. No. 07/409,364 filed Sep. 19, 1989, now abandoned all having the same title "CORROSION RESISTANT COATED ARTICLES AND PROCESS FOR MAKING SAME. "
BACKGROUND OF THE INVENTION
This invention relates to articles having integral chemically-formed surface coatings that provide an improved combination of adherence and corrosion resistant properties to such products and to a process for making same. More particularly, the articles of this invention have on their surfaces an integral, chemically-formed coating that is strongly adherent and resistant to chipping or flaking at elevated temperatures and provides to the product a unique combination of corrosion properties including commercially satisfactory resistance to oxidation during use in gases at elevated temperatures such as encountered in the engine compartments of vehicle engines, resistance to corrosion from humidity, from organic solvents such as ethylene glycol, oils and gasoline, from acidic or alkaline solutions such as salt spray to the extent that is required of a base for paint or other protective organic or water-based protective coating on parts used within the engine compartments of vehicles.
Chemical coatings on aluminum for various purposes including oxides, chromate-phosphates, chromates, and phosphates have long been known and have been commercially employed since the 1930's when the original Bauer-Vogel process of German patent 423,758 for chemically forming oxide coatings on aluminum was improved in 1937 by reducing the time required from hours to minutes but still produced only gray coatings at near boiling temperatures, see Aluminum, 1937, 19, 608-11 (hereby expressly incorporated by reference). Colorless oxide coatings suitable for a wider range of aluminum alloys were later developed but were less desirable as a base for paint than the Bauer-Vogel products and could not be successfully dyed, see Aluminum, 1938, 20, 536-8 (hereby expressly incorporated by reference). Chromate-phosphates were developed in the 1940's as paint base coatings and disclosed in U.S. Pat. No. 2,438,877 and later modified as disclosed in British Patent 1,114,645 and French Patent 1,477,179 (all of which are hereby expressly incorporated by reference). Chromate processes developed during the 1960's and 1970's have been asserted to provide improved paint bases relative to the chromate-phosphate coatings and are disclosed in a number of United States patents, including U.S. Pat. Nos., 3,009,482, 3,391,031, 3,404,043, 3,410,707, 3,447,972, 3,446,717, 3,982,951, 4,036,667, 4,146,410 and British Patent 1,409,413, all of which are hereby expressly incorporated by reference. A number of additional patents discuss various types of chemical coatings, protective layers or processes, and include U.S. Pat. Nos. Re. 28,015, Re. 29,827, 1,811,298, 1,840,562, 1,946,151, 1,995,225, 2,035,380, 2,059,801, 2,060,192, 2,106,227, 2,106,904, 2,134,830, 2,440,969, 2,680,081, 2,694,020, 2,825,697, 3,175,931, 3,214,287, 3,400,021, 3,950,575, 3,967,984, 3,982,951, 4,070,193, 4,141,758, 4,200,475, 4,341,878, 4,569,699, and 4,657,599, all of which are hereby expressly incorporated by reference.
Even though extensive development of chemical coatings for aluminum and its alloys has resulted from worldwide research efforts each heretofore known process and product present some problem or lack a particular set of properties needed for use in specific applications. Thus, there is a continuing need for other efficient, low cost processes for providing corrosion resistant coatings on aluminum and its alloys to satisfy specific commercial needs. For example, there are needs for uses other than bases for paints or other organic finishes, other needs for coating aluminum alloy substrates which contain alloy constituents known to hinder coating formation on alloys such as magnesium, silicon, copper, chromium and manganese. There remains a need for coating aluminum alloy sand castings which contain silicon, copper and magnesium and may contain other heavy metals such as nickel, chromium, titanium or silver to provide coatings that resist thermal and gaseous engine fume degradation and development of localized white corrosion products during long periods of use such as in commercial truck and automobile engine compartments. There also remains a need for improved coatings for zinc-based, cadmium-based, and magnesium-based materials.
The present invention provides articles that are coated with a new integral coating that results in good corrosion resistance and resistance to dislodgment during use in environments, such as vehicle environments. This invention also provides an economic, continuous process for producing the new coated articles of this invention, as will be described hereinafter.
SUMMARY OF THE INVENTION
In accordance with the present invention, articles are coated with a new, thin colorless coating, which preserves the appearance of the uncoated articles. In a first preferred embodiment, the coating contains as its essential component a chemical complex of alkali metal-chromium-silicates as defined in the claims. In an alternative second preferred embodiment, the coating contains as its essential components a "water glass" complex of alkali metal-silicates and water; a metallic oxide; and a lithium-containing compound. The amount of the essential components in the coating in each preferred embodiment is that which is sufficient to provide the coated articles with an unexpectedly unique combination of properties of appearance, adherence, resistance to chipping and flaking, corrosion resistance to acidic and alkaline gases and aqueous solutions and oils, solvents and fuels, and is sufficient to make it suitable as a surface treatment, such as a base for paint and the equivalent of paint on parts within the engine compartment of vehicles. The preferred coatings are colorless and so thin as to be virtually invisible to the naked eye. The coating thickness varies from about 50 angstroms, or 0.0005 micron, to about 2 microns.
This invention also provides a process for the continuous, efficient production of the improved coated articles of this invention. The continuous process makes use of known production line dip or spray apparatus in which the articles or parts to be coated are mounted on racks or in rotating barrels supported on conveyor means capable of sequentially contacting the articles with aqueous solutions positioned in a plurality of in-line tanks, each tank containing an aqueous solution of selected coating-producing ingredients with intervening rinse solution-containing tanks, the in-line apparatus terminating in conventional means for drying the coated parts. The process of this invention has the advantages of using dilute aqueous solutions of inexpensive, commercially available chemicals that are maintained at low treatment bath temperatures ranging from ambient room temperatures up to about 160° F., or 71° C., and for short times of contact of the solution with the article being coated, for example, by immersion contact in the range of about 20-180 seconds, preferably about 30 seconds, or spray contact for about 10 to 60 seconds and preferably 5-20 seconds. Longer contact times are also possible. The end result is that the continuous production process provides a resultant product that is less expensive than most heretofore available corrosion resistant products.
The process of this invention is useful to form coatings on non-ferrous metals such as aluminum, zinc, cadmium, magnesium and many of their alloys that are commercially available as sand castings, plate, sheet, forgings or extrusions. Particularly good results have been obtained by using the process for coating vehicle engine manifolds made from sand cast aluminum alloys as described in Example I. Also, good results are obtained using the process for coating zinc plated steels such as described in Example V.
DETAILED DESCRIPTION OF THE INVENTION
In a first embodiment the new articles of this invention include articles fabricated from aluminum or an aluminum alloy which have on their surfaces a thin, adherent coating having a thickness up to about 2 microns comprising as its essential component a chemical complex of an alkali metal-chromium-silicate having proportions of each in the range, expressed as oxides in weight percent of:
Na 2 O-9.9%-12.1%;
Cr 2 O 3 -4.1%-4.3%; and
SiO 2 -76.8%-91.2%.
In an alternative second preferred embodiment, the new articles of this invention include articles fabricated from aluminum, zinc, cadmium, magnesium or their alloys which have on their surfaces a thin adherent coating having a thickness up to about 2 microns, and comprising as its essential components a water glass complex, a metallic oxide, and a lithium-containing compound. Water glass complexes are known in the art and typically include an alkali metal-silicate (such as including Na 2 O and SiO 2 ) and water. Preferably the constituents of the water glass (e.g. H 2 O, Na 2 O and SiO 2 ) are present at or near their art-disclosed levels, and more preferably are present such that the proportions of each, expressed in percent, by weight of the final bath composition (wherein "the final bath composition" refers to an aqueous solution in which the coating has been dissolved or dispersed) are:
Na 2 O in an amount of about 0.44 to about 0.82%, and more preferably about 0.63%;
SiO 2 in an amount of about 1.27 to about 2.37%, and more preferably about 1.82%; and
H 2 O in an amount of about 2.29 to about 4.25%, and more preferably about 3.27%.
Accordingly, preferably the water glass complex is present in the coating composition in an amount of about 4 to about 7.44 percent, by weight of the final bath composition, and more preferably is present in an amount of about 5.72 percent by weight of the final bath composition.
The coating of the alternative second preferred embodiment further comprises a metallic oxide-containing compound, and preferably a molybdenum oxide compound such as that having the chemical formula MoO 3 . In a highly preferred embodiment, the metallic oxide-containing compound, preferably MoO 3 , is present in an amount of about 0.1 to about 1.0%, more preferably from about 0.5 to about 1.0% and still more preferably at about 0.50%, by weight of the final bath composition.
Preferably the coating of the present alternative second preferred embodiment further comprises a lithium-containing compound, and more preferably a lithium hydroxide monohydrate (LiOH.H 2 O) compound. The lithium-containing compound, preferably LiOH.H 2 O, is present in an amount of about 0.1 to about 1.0 percent, by weight of the final bath composition, more preferably about 0 5 to about 1.0 percent, by weight of the final bath composition, and still more preferably about 0.50 percent by weight of the final bath composition.
Of course, the skilled artisan will appreciate that different concentrations than those set forth above are possible, particularly where concentrates containing the coating are involved.
The coating of the present alternative second embodiment, as well as the first embodiment described herein, is useful for coating articles made from aluminum or its alloys. The coating of the present alternative second embodiment also unexpectedly improves corrosion resistance of articles made from non-ferrous materials such as zinc, cadmium, magnesium and their respective alloys. The coating is especially useful as applied over steel articles plated (using conventional techniques) with zinc, cadmium or their respective alloys.
The process for making the coated new articles of this invention using the composition of the first preferred embodiment comprises the following sequential steps, omitting intervening water rinsing steps:
1) cleaning with an acidic cleaner to remove foreign matter, oils, greases or surface remnants from the forming of the article;
2) contacting the cleaned article from step 1 with an aqueous, strongly acidic solution capable of removing surface aluminum oxides;
3) contacting the clean, rinsed, substantially oxide-free article of step 2 with an aqueous acidic solution for forming a chromium-silicate-containing adherent surface coating;
4) elevated temperature water rinsing of the step 3 coated article;
5) contacting the rinsed coated article of step 4 with an aqueous, strongly alkaline solution capable of forming an alkali metal-chromium silicate coating containing a chemical complex having the composition, expressed as oxides in percent by weight of:
Na 2 O-9.9%-12.1%;
Cr 2 O 3 -4.1%-4.3%; and
SiO 2 -76.8%-91.2%.
A preferred method for coating articles using the composition of the alternative second preferred embodiment comprises the steps of:
1) cleaning with an acidic cleaner to remove foreign matter, oils, greases or surface remnants from the forming of the article;
2) contacting the cleaned article from step 1 with an aqueous, strongly acidic solution capable of removing surface metallic oxides from the surface of the cleaned article;
3) contacting the clean, rinsed, substantially oxide-free article of step 2 with an aqueous acidic solution for forming an adherent surface coating;
4) elevated temperature water rinsing of the step 3 coated article;
5) contacting the rinsed coated article of step 4 with a solution (i.e bath) capable of forming a coating, wherein the coating is made by adding to water an admixture containing the following composition, expressed in percent, by weight of the final bath composition:
Na 2 O in an amount of about 0.44% to about 0.82%, and more preferably about 0.63%;
SiO 2 in an amount of about 1.27% to about 2.37%, and more preferably about 1.82%;
H 2 O in an amount of about 2.29% to about 4.25%, and more preferably about 3.27%;
MoO 3 in an amount of about 0.1% to about 1.0%, more preferably about 0.5% to about 1.0%, and still more preferably about 0.5%; and
LiOH.H 2 O in an amount of about 0.1% to about 1.0%, more preferably about 0.5% to about 1.0%, and still more preferably about 0.5%.
The following provides specific preferred details concerning the above methods of coating with the compositions of the first preferred embodiment and the alternative second preferred embodiment. The description that follows is of a process which is particularly preferred for use to coat articles of aluminum or aluminum alloy Nonetheless, the skilled artisan will appreciate that the methods are also useful for coating articles made from many other nonferrous materials such as zinc, cadmium, magnesium or their alloys In this regard, steps ordinarily taken to treat aluminum or aluminum alloys may be deleted or substituted with like steps known in the art for treating zinc, cadmium, magnesium or their alloys. Further, the skilled artisan will appreciate that techniques such as rinsing, oxide removal techniques and techniques for forming an adherent surface coating (e.g. chromating) are generally known in the art, and even though the following discussion constitutes a description of preferred techniques, such techniques can be substituted with any suitable known techniques, or the sequence of steps may be modified, for achieving the purpose stated.
Cleaning solutions suitable for use in the first step of the process include a wide variety of commercially available inhibited acidic cleaners. Good results are obtained by using an aqueous phosphoric acid solution containing phosphoric acid in an amount sufficient to give a pH in the range of about 5 to 6, and which may contain organic solvents such as tri- or diethylene glycol monobutyl ether in an amount of about 2% to 10% and may also contain any of a number of commercially available organic surfactants, for example, about 2% to 10% of a fluorocarbon surfactant such as PC 95 available under the tradename Fluorad from Minnesota Mining & Manufacturing Co. The parts to be cleaned are immersed in such a cleaning solution at a temperature of about 130° to 180° F. for 2 to 5 minutes, preferably about 3 minutes, followed by rinsing in water at a temperature of about 120° to 140° F., preferably about 130° F., for 30 to 90 seconds.
The cleaned articles from step 1 are then contacted with a stronger aqueous acidic solution capable of removing oxides from the surfaces of the article. Good results are obtained by using a chromic acid-based solution containing 70% to 80% chromic acid, 20% to 30% potassium dichromate and 2% to 4% ammonium silicofluoride in a concentration of 3 to 6 oz./gal., preferably about 4 oz./gal. to form a solution having a pH in the range of about 0.5 to 1 and contacting the article with such solution for a time period in the range of about 1/2 to about 3 minutes. The oxide free cleaned articles are then water rinsed in one to three water tanks at ambient temperatures, for about 30 seconds in each rinse solution.
The deoxidized, rinsed article is then subjected in step 3 to a coating forming step by contacting the article by dip or spray with a suitable aqueous solution to form a chromate coating, and preferably a silicon-chromate coating on the surface. Good results are obtained in forming such coatings by using an aqueous solution made up by adding to water, preferably deionized water, about 0.5-2.0 oz./gallon of a composition containing in weight percent about 50% to 60% chromic acid, about 20% to 30% barium nitrate and about 15-20% sodium silicofluoride and preferably containing a catalyst in an amount of up to about 5% such as an alkali metal ferricyanide, i.e., potassium or sodium ferricyanide to form a solution having a pH in the range of about 1.2-1.9 and preferably about 1.5. Other formulations which are also satisfactory for use may omit the barium nitrate component, and may include additional coating catalysts of the molybdic acid type in the event color is desired, such as the formulations disclosed in U.S. Pat. No. 3,009,842 (hereby incorporated by reference) and in the other patents identified therein. Other useful, but less desirable compositions that are suitable for coated articles having less stringent requirements for salt spray resistance include those set forth in U.S. Pat. Nos. 3,410,707 and 3,404,043, which are hereby incorporated by reference. Compositions that are satisfactory are commercially available from a wide variety of suppliers in the United States and especially good results are obtained by using the material commercially designated Iridit 14-2 which is available from Witco Chemical Company.
It is to be further understood that the proportions of the components in the preferred composition described above are not critical to the formation of the base coating that is formed directly on the oxide free surface of the metallic article being coated in accordance with this invention. Useful coated articles are formed when the formulation given above is varied to employ proportions within the ranges set forth in U.S. Pat. No. 3,982,951 (hereby incorporated by reference). When the article is dipped, an immersion time of about 30 seconds is adequate when the temperature is maintained at less than 120° F., or 49° C. When the article is sprayed at a similar temperature, about 5 to 20 seconds is adequate.
It is important to insure a thorough water rinsing of the coating formed in step number three. This is best done using deionized water at ambient temperature, i.e., about 60° F.-90° F., in 1 to 3 immersions, preferably three, for about 30 seconds each, or a single power spray for about 30 seconds. Following the thorough ambient temperature rinsing of the coated article from step 3, the fourth step is a final water rinse at a temperature that is higher than the ambient temperature employed in step 3. This higher temperature rinse serves to remove unwanted chromate colors, if present, and also to prepare the coating from step three to enhance its reactivity with the components in the strong alkaline solution to be next applied to form the coating of this invention. Preferred conditions for step 4 include using deionized water at a temperature in the range of about ambient to about 160°, and more preferably about 110° F. to 160° F., or about 43° C. to 71° C., and preferably about 130° F. or 54°-55° C. The coated article from step 3 should be rinsed at the selected temperature for a time sufficient to raise the temperature of the article to about the elevated temperature of the rinse solution. Thus, the optimum time required varies for specific articles depending on the selected composition used in step 3 and also depends on the size or bulk of the article. The optimum time may be affected by the particular alloy composition of the article being coated. For example, the time required may vary from about 30 seconds up to about 5 minutes, and the needed, or optimum, time is easily determinable by a few trials Where the article is formed by sand casting a metallic material, the article may include pits or surface imperfections. When such imperfections are present it has been found that potential, undesirable white corrosion products may develop in such pit or imperfection areas during salt spray testing or use and this undesirable corrosion can be avoided by exercising care in selecting a sufficiently high temperature toward the 160° F. limit and a sufficiently long time for the selected elevated temperature rinse step.
The elevated temperature rinsed coated article from step 4 is then subjected in step 5 to a second coating step by contacting the coated article with the coating composition of the first preferred embodiment, the coating composition of the alternative second preferred embodiment, or mixtures thereof.
When coated with the coating composition of the first preferred embodiment the coated article from step 4 is contacted with a highly alkaline aqueous solution having a pH in the range of about 10 to about 12, and more preferably about 11 to 12, and containing disodium oxide and silicon dioxide components having a weight ratio of SiO 2 /Na 2 O in the range of about 2.4 to 3.25 and a range of densities between about 40 and 52 degrees Baume' at 20° C. Otherwise expressed the silicate solutions may contain in weight percent, about 26.5% to about 33.2% SiO 2 and about 8.6% to about 13.9% Na 2 O, at a similar range of densities. Preferred solutions are those which contain disodium oxide and silicon dioxide in a weight ratio of SiO 2 /Na 2 O of about 2.5 to 2.9 and a density in the range of about 42 to about 47 degrees Baume' at 20° C. The best results have been obtained from a solution formulated by adding to water an amount of about 2% to 6% by volume, and more preferably about 4.5%, of a sticky, heavy silicate having a weight ratio of SiO 2 /Na 2 O of 2.9 and a density of 47° F. Baume' at 20° C. to thereby produce a coating solution having a pH of about 11.5.
When coated with a highly preferred coating composition of the alternative second preferred embodiment the coated article from step 4 is contacted with an aqueous solution or bath having a pH in the range of about 10.5 to about 12 being prepared from a water glass complex including disodium oxide, silicon dioxide, and water, having a weight ratio of SiO 2 /Na 2 O/H 2 O in the range of about 0.44 to 0.82 parts Na 2 O: about 1.27 to about 2.37 parts SiO 2 : about 2.29 to about 4.25 parts H 2 O and still more preferably about 0.63 parts Na 2 O to about 1.82 parts SiO 2 to about 3.27 parts H 2 O, and a range of densities between about 40 and about 52 degrees Baume' at 20° C. The solution further comprises MoO 3 and LiOH.H 2 O present such that the weight ratio of MoO 3 to LiOH.H 2 O is about 1:1, and further wherein each of MoO 3 and LiOH.H 2 O are present in an amount of about 0.5 parts by weight to about 1.82 parts SiO 2 , about 0.63 parts Na 2 O, and about 3.27 parts H 2 O.
Otherwise expressed (as percent, by weight of the final bath composition), a highly preferred final bath composition preferably includes the water glass complex having constituents present in an amount of about 0.63 percent Na 2 O, about 1.82 percent SiO 2 , and about 3 27 percent H 2 O. The final bath composition further includes MoO 3 in an amount of about 0.5 percent, and LiOH.H 2 O in an amount of about 0.5 percent.
In a highly preferred embodiment the coated article from step 4 is contacted with an aqueous solution formed by adding to water an amount of about 2 to about 6 percent by volume of the final bath composition of a compound containing about 5.72 parts by weight water glass (i.e., about 0.63 parts by weight Na 2 O; about 1.82 parts by weight SiO 2 ; and about 3.27 parts by weight water); about 0.5 parts by weight MoO 3 ; and about 0.5 parts by weight LiOH.H 2 O.
The articles from step 4 are immersed for about 30 seconds to 2 minutes in the solution of step 5 at a temperature of ambient to about 130° F., with the solution having a preferred pH between about 11.2 and 11.5 when using the composition of the first embodiment, and a pH between about 10.5 and 12, when using the composition of the alternative second preferred embodiment. The thus coated articles are finally dried either in ambient air, by using clean forced air, or by placing them in a low temperature furnace at 150° to 200° F. for 1 to 2 minutes.
The dried, coated articles are the new articles of this invention. In their preferred form, the articles have a thin, adherent coating that is substantially invisible to the naked eye but has a thickness in the range of about 50 angstroms to about 20,000 angstroms, or about 0.0005 micron to about 2 microns. The coated article has the same overall appearance as the uncoated article unless a tint is intentionally produced by varying the composition of step 3 or the temperature of step 4 as will be readily apparent to those skilled in the art of forming chromate coatings.
Tests conducted on the articles coated with the composition of the first preferred embodiment have established that the coating is sufficiently adherent and hard to resist chipping or flaking when used at elevated temperatures up to about 400° F. such as may be attained in the engine compartments of automobiles and trucks, and even as high as about 1200° F. When the articles from step 5 using the composition of the first preferred embodiment were vehicle intake manifolds and were tested for salt spray resistance under the conditions of ASTM B-117 test method no corrosion products were visible for 250 hours.
Articles coated with the composition of the alternative second preferred composition exhibit no visible corrosion products for at least about 250 hours. For some applications (such as applied to panels of forged aluminum alloy 1100 treated with trivalent chromate) no corrosion products are visible for about 720 hours.
EXAMPLE I
Automobile intake manifolds were sand cast from a Ford Motor material designated 319 Aluminum having a specification of 5.5-6.5 Si, 0.4-0.6 Mn., 3.0-4.0 Cu, 0.1-0.6 Mg., 0.7-1.0 Zn and 1.0 Max Fe. The articles were mounted on racks carried by a dip-type conveyor adapted to dip the racks into tanks to form coated manifold articles of this invention in the following sequence of steps:
1) A tank of aqueous acidic cleaning solution was prepared to contain, in percent by weight, 5% of the commercial product Niklad Alprep 230 a . The intake manifolds were dipped in the solution having a pH of 5-6 at approximately 130° F., for about 2 minutes;
2) water rinse at 130° F.±5° F., for about 30 seconds;
3) repeat step 2;
4) A tank of aqueous acidic coating solution was prepared by mixing about 1 oz. per gallon of Iridit 14-2 b with water to form a solution having a pH of 1.4-1.5. The rinsed manifolds from step 3 were immersed in the solution for 30 seconds;
5) Water rinse at ambient room temperature of about 60° F.-90° F. for 30 seconds;
6) repeat step 5;
7) A tank of deoxidizing strongly acidic cleaner was prepared by mixing 4 oz./gallon of Deoxidizer No. 2 c with water to form a solution having a pH of 0.5-1.0. The rinsed manifolds of step 6 were immersed in the solution for 90 seconds;
8) water rinse at ambient temperature;
9) repeat step 8;
10) repeat step 8;
11) repeat immersion for 3 minutes in the same solution as in step 4;
12) water rinse at ambient temperature;
13) repeat step 12;
14) repeat step 12;
15) water rinse, deionized water, at approximately 140° F.-150° F. for about 30-50 seconds.
16) A tank of strongly alkaline coating solution was prepared by mixing 4% by volume of Ultraseal d to form a solution having a pH of about 11.5. The manifolds from step 15 were immersed at a temperature of about 130° F. for about 30 seconds.
17) The coated manifolds from step 16 were drained and dried at ambient temperature.
Coated articles from step 17 were analyzed using Electron Spectroscopy for Chemical Analysis (ESCA) to establish coating thickness and the elemental composition of the surface coating. The coating thickness of the dried articles from step 17 was greater than 50 angstroms and less than 2 microns.
An ARL SEMQ electron microprobe analysis using 10 KeV accelerating voltage and wave length dispersive spectrometry (WDX) established that the elemental surface coating on the rinsed article from step 6 contained 4.2% silicon, 0.6% chromium and 2.0% oxygen, and it was concluded to be majorly a silicon-chromate coating. The rinsed coating from step 14, which resulted from the second application of the same solution which produced the article from step 6, included increased quantities of silicon and chromium in the coating to 7.4% silicon, 1.1% chromium and 2.0% oxygen. After the rinsed and elevated temperature silicon-chromate coating of step 15 was contacted with the strongly alkaline solution in step 16 the final, dried coating was analyzed. The above identified electron microprobe and accelerating voltage was used. The coating composition, in weight percent, expressed as oxides of the detected elements and taking into account the applicable accuracy level of the use conditions of the analyzing equipment, contained:
9.9-12.1% Na 2 O;
4.1-4.3% Cr 2 O 3 ; and
76.8-91.2% SiO 2 .
Articles were tested for salt spray resistance using ASTM B-117 test conditions and no corrosion products were visible after 250 hours. Other articles were tested under Engineering material Specification Number ESE-M2P128-A of Ford Motor Co. which is the specification of a superior quality of paint required on the engine, engine accessories and/or parts within the engine compartments of automobiles and trucks. Coated articles from step 17 of the above described process qualified as passing all of the requirements of a superior quality paint including adhesion, hardness, water resistance, gasoline resistance, hot oil resistance, glycol resistance, heat resistance and 96 hours salt spray resistance using the conditions of ASTM B-117.
The process was also used to coat other manifolds sand cast from the materials designated alloy 355.0 - T6, UNS Number A03550, and a die Cast aluminum alloy designated BS 1490-LM20 having a specification of 13.0 Si, 1.0 Iron, 0.5 Mn, 0.4 Cu, 0.2 Mg, 0.2 Zn, 0.1 Ti, 0.1 Ni, 0.1 Pb and 0.1 Sn.
Substantially similar results are obtained when the above process is used to coat articles made from zinc, cadmium, magnesium or their alloys.
While not intending to be bound by theory, it is believed that the steps above are unique in opening the "pores" on the surface of the metal, allowing the beneficial coating to impregnate these pores for more efficacious treatment and sealing of the metallic surface.
EXAMPLE II
Diode plates for automobile alternators that were stamped into the desired configuration using extruded aluminum alloy 6061-T6, AMS 4150G were coated using the process of this invention. The diode plates were approximately 5" long, 5/8" wide and 1/8" thick and in the shape of an arcuate segment of a circle having a radius of about 5 inches, and provided with a plurality of openings for receiving and supporting diodes.
A quantity of the stamped diode plates were positioned in rotatable barrels, as opposed to the racks described in Example I, and the barrels were sequentially processed through the same coating solutions used in Example I except that steps 4-6 were omitted and certain of the times of immersion in some of the other solutions were changed. In step 1 the immersion was for 3 minutes. In step 7, the immersion was for 2-3 minutes. In step 11, the silicon-chromate coating forming tank, the immersion time was 12 minutes and immersion time in the rinses in steps 12-15 was for a total of 5 minutes.
The coated diode plates retained the aluminum appearance of the stamped parts and were coated with an adherent, scratch and chip resistance coating having a thickness of approximately 2 microns.
The coated diode plates from step 17 were tested for their ability to continue to pass current when assembled into an automobile alternator that was positioned in a salt spray cabinet using the salt spray test conditions of ASTM B-117. The diode plates were found to resist salt spray corrosion and to continue to pass the test current without failure for 1000 hours.
EXAMPLE III
Manifolds of aluminum alloy SAE-331 (AA333)-F Temper are cast, coated with hexavalent chromate (bleached to colorless). The manifolds are then coated to a thickness of about 1-2 microns, by contacting the manifolds with an aqueous bath having therein a coating composition set forth in Table I (expressed as parts by weight of the final bath composition).
TABLE I______________________________________Component Parts by Weight______________________________________Water glass: 5.72Na.sub.2 O (0.63 parts by weight)SiO.sub.2 (1.82 parts by weight)H.sub.2 O (3.27 parts by weight)MoO.sub.3 0.50LiOH.H.sub.2 O 0.50______________________________________
Using salt spray test conditions of ASTM B117, 264 hours pass before the first sign of corrosion.
EXAMPLE IV
Forged panels of aluminum alloy 1100 having a composition of about 99.0%, by weight, aluminum are coated with trivalent chromate, and are coated to a thickness of about 1-2 microns with the composition of Table I in Example III. Using salt spray test conditions of ASTM B117, 720 hours pass before the first sign of corrosion. Substantially similar results are obtained with a hexavalent chromate coating.
EXAMPLE V
Three specimens (A,B,C) of a low carbon (e.g. AISI types 1018-1020 steel) steel are plated with zinc to a thickness of about 0.0003" to about 0.0005". Specimen A is yellow chromate coated. Specimen B is black chromate coated. Specimen C is clear chromate coated.
Specimens A, B and C are each coated to a thickness of about 1-2 microns with the composition of Table I in Example III. Using salt spray test conditions of ASTM B117, 384 hours pass before the first sign of corrosion in specimens A and B; and 336 hours pass before the first sign of corrosion in specimen C.
Substantially similar results are obtained with cadmium plated materials. While the above description constitutes the preferred embodiments of the present invention, it will be appreciated that the invention is susceptible of modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims. | 4y
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BACKGROUND OF THE INVENTION
The need for keyed right-angle locks for doors and windows is well established. The size of such locks must be kept small to fit the dimensions of mounting surfaces. These constraints determine to a great degree the applicable mechanism.
The use of rack and pinion gears to change rotary motion to linear motion, and vice versa, is well known. The use of two such systems to produce reciprocating motion at right angles is also well known and has been described for example in U.S. Pat. Nos. 1,195,881; 1,251,467; 2,431,105; 3,561,805; and 4,163,375. Except for U.S. Pat. No. 4,163,375, the patent disclosures are not suitable for patio door locks, due primarily to their bulk.
In U.S. Pat. No. 4,163,375, two rack and pinion systems, mounted at right angles to one another are used to extend and to retract the bolt. And although a rack and pinion system is ideally suited to provide reciprocating motion of a cylindrical bolt in order to provide a bolt that is free to rotate to inhibit sawing in a forced entry attempt, such a system is unnecessarily complex for the barrel lock assembly drive mechanism. Thus, there exists a need for a small, sturdy, key-operated right-angle lock that provides for maximum security, is easily made, and can be used in essentially every conceivable position while at the same time concealing the means for holding the lock assembly together, and in which the bolt can be locked when extended in either direction, and the barrel lock easily replaced, when necessary or desirable.
SUMMARY OF THE INVENTION
In a push-pull right angle lock according to the present invention, a barrel lock assembly has a keyed barrel lock contained in a longitudinal bore in a cylindrical housing, from which an extension arm depends and which is retained in a two-part longitudinally split case so as to be free to be moved in and out of the case between extended and retracted positions so as to cause a cylindrical bolt within the case to extend outwardly from one side of the case or the other. The bolt, which is mounted at right angles to the barrel lock assembly, can be locked in either of the extended positions by means of a cam at the end of the barrel lock which engages a cam-lug within the housing to extend the lug into appropriate recesses in the case thereby preventing movement of the barrel lock housing and bolt. The ability to extend and lock the bolt in both directions provides for complete flexibility of mounting positions, while at the same time concealing the means for holding the two case sections together. Transfer of the linear motion of the barrel lock assembly to the rectilinear motion of the bolt is accomplished by a rotatable disk with an arcuate segment of a pinion gear which engages circular rack teeth on the bolt. A crank pin on the disk face, displaced approximately 90° from the pinion gear, engages a slot in the extension arm of the barrel lock housing so as to rotate the disk in response to linear movement of the housing.
Two small apertures are provided in the lock case, one of which is aligned with a passageway in the barrel lock housing when the housing is in the extended position and the other when in the retracted position to permit disengagement of a spring-biased retainer leaf on the barrel lock which holds the barrel lock in the cylindrical housing only when the barrel lock is in the unlocked position so that the barrel lock may be removed from the housing and replaced.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention may more readily be understood by referring to the accompanying drawing in which:
FIG. 1 is an isometric view of the rotary lock of the present invention as installed on a sliding glass door;
FIG. 2 is an exploded view of the lock shown in FIG. 1;
FIG. 3 is a right side elevational view of the lock shown in FIG. 1;
FIG. 4 is a plan view of the lock shown in FIG. 1;
FIG. 5 is a sectional view taken along lines 5--5 of FIG. 4;
FIG. 6 is a partial plan view of the lock, similar to FIG. 4, but showing the lock bolt in the opposite disposition from that shown in FIG. 4; and
FIG. 7 is an isometric view of the lock housing for the barrel lock of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, a rotary patio door lock 10, according to the present invention, is mounted on a sliding patio door assembly 12 which consists of an inner door 14 and an outer door 16. Typically, one of the doors 14, 16 is fixed and the other of the doors 14, 16 slides. The door 14 has a frame 18 to which the lock 10 is mounted by three mounting screws 20. The lock 10 has a first body shell member 22 and a second body shell member 24 which are fixed to one another to form a case 25 by expanding a small diameter end-extension 54 of a shaft 26, so as to enclose a barrel lock assembly 28, disk 64 and bolt 30 (see FIG. 2). A locking bolt 30 extends out of the lock 10 on both sides thereof. The door 16 has a plurality of apertures 32 drilled therein into which the bolt 30 may be extended so as to lock the sliding door assembly 12 in the desired position, which may be either completely closed or partially opened to provide ventilation if desired.
FIG. 2 is an exploded view of the rotary lock 10 showing the first and second body shell members 22, 24 separated from one another. The barrel lock assembly 28 is seen to have a barrel lock 34 which is disposed in a barrel lock housing 36 and is locked into the housing 36 by a spring-biased retainer leaf 90. The locking cam lug 38 has an aperture 40 formed thereon into which a cam 42 depending from the barrel lock 34 is disposed. A key 44 is used to rotate the barrel lock 34 within the housing 36 so as to selectively extend or retract the locking cam lug 38 into or out of retaining slots 46, 48 of shell 22 and 46A and 48A of shell 24 when assembled as showin in FIG. 1 to form the case 25.
The body shell members 22, 24 each have three mounting apertures 50 formed therein to receive the three mounting screws 20 which extend through the case 25 to mount the lock 10 to the door frame. The shaft 26 has a shoulder 52 and a smaller diameter tip 54. The first body shell member 22 has a face 56, with a passage 58 formed therein to receive the tip 54 of the shaft 26, so that the shaft shoulder 52 abuts the face 56. The second body shell member 24 has an alignment pin 60 which mates with a cylindrical recess 62 in the first body shell member 22 so as to properly align the body shell members 22, 24 when they are placed together. After being positioned together, the tip 54 is expanded against a shoulder (not shown, see FIG. 3) in the passage 58 to thereby hold the body shell members 22, 24 together to form the unitary case 25 which can not be separated into the shell members 22, 24 without drilling out the expanded tip 54.
A disk 64 is mounted on the shaft 26 so as to be rotatable thereabout. The disk 64 has an arcuate pinion gear section 66 formed thereon so as to be offset approximately 90 degrees from a crank pin 68 extending outwardly from the disk 64 parallel to a bearing aperture 70, through which the shaft 26 extends so as to rotatably mount the disk 64 on the shaft 26.
The bolt 30 has a rack portion 72 formed thereon of circular teeth in the central portion thereof, the bolt 30 being selected to be of a length so as to extend out both sides of the lock 10. As seen in FIG. 2, the bolt 30 is disposed within pairs of semi-circular recesses 74, 76 formed in the first body shell member 22 and complementary recesses 74A, 76A formed in the second body shell member 24.
Referring now to FIG. 3, the rotary patio door lock 10 is shown in left side elevational view, partially broken away, so as to illustrate the attachment of the two body shell members 22, 24 together. The shaft 26 is seen to abut the face 56 and the tip 54 to extend through the passage 58 which opens onto a face--78 of the first body shell member 22 so as to form an enlarged aperture 80. The end of tip 54 has been expanded, shown by 54A, into the enlarged aperture 80, thereby locking the two body shell members 22, 24 together to form the case 25. As shown in FIG. 3, the barrel lock assembly 28 is in its extended position, in which it extends the greatest length beyond the body shell members 22, 24. The barrel lock assembly may be fixed in this disposition by rotating the lock 34 by the key 44, so as to cause the locking cam lug 38 to extend into the first retaining slots--46, 46A.
Referring now to FIG. 4, there is shown a plan view, partially broken away, of the lock 10. In FIG. 4, the lock 10 is locked in its extended barrel lock assembly disposition, thereby locking the bolt 30 in a disposition so as to extend principally out of the right hand side of the lock 10. The bolt 30 is held in this locked disposition by the engagement of the rack portion 72 with the arcuate pinion gear portion 66 of the disk 64, which is fixed against rotation by the combined engagement of the crank pin 68 with an elongated lateral recess 82 formed in a laterally offset extension arm 84 of the barrel housing 36 (see FIG. 7). As will be apparent from FIGS. 3 and 4, the extension arm 84 is laterally offset with respect to the plane of disk 64, the plane of the disk 64 being coplanar with the bolt 30.
In FIG. 6, the lock 10 is shown in its barrel lock assembly retracted disposition. The disk 64 has been rotated clockwise from the disposition shown in FIG. 4, thereby causing the pinion gear portion 66, which engages the rack portion 72 of the bolt 30, to move the bolt 30 to the left, thereby causing the bolt 30 to extend principally out of the left hand side of the lock 10. The clockwise rotation of the disk 64 is caused by forward movement of the barrel housing 36 into the lock case 25 which rotates the crank pin 68 disposed in the elongated lateral recess 82 of the extension arm 84. In FIG. 6, the barrel lock assembly 28 is shown as unlocked in the retracted position, as the locking cam lug 38 does not extend into the second retaining slot 48A. Rotation of the key 44 in a counter-clockwise direction will cause the locking cam lug 38 to be extended out into the slot 48A.
In order to initiate the movement of the barrel lock assembly 28 from the disposition shown in FIG. 4 to the disposition shown in FIG. 6, the key 44 is inserted into the lock and rotated, thereby retracting the locking cam lug 38 into the barrel housing 36, so as to permit the movement of the barrel lock assembly 28 in response to manual pressure by the user.
FIG. 7 is an isometric view of the barrel lock housing 36 which illustrates a slot 86 in which the locking cam lug 38 is disposed (see FIG. 2) so as to be selectively extendable therefrom and retractable therewithin. FIG. 7 also illustrates the depending extension arm 84 and elongated lateral recess 82 which, in cooperation with the crank pin 68, translates the linear longitudinal movement of the barrel lock assembly 28 into linear longitudinal movement of the bolt 30 in a direction normal to the barrel lock assembly movement by means of the bolt rack 72 and arcuate pinion gear 66 of the disk 64.
As will be seen in FIG. 3, the axis of symmetry of the barrel lock assembly 28 lies in the plane of rotation of the arcuate pinion gear 66, but the extension arm 84 is laterally offset therefrom. The arcuate pinion gear 66 and bolt 30 are coplanar with respect to one another, so that the longitudional axis of movement of the barrel lock assembly 28 intersects the longitudional axis of movement of the bolt 30 and is normal thereto.
A particular advantage of the rotary patio door lock of the present invention is that the door lock 10 is either a right hand or a left hand lock. That is, the bolt 30 can be locked in an extended position either extending from the right hand side of the lock 10 or the left hand side of the lock 10 as desired. Thus, the lock 10 can be mounted in either the lower portion of the door, and the key 44 inserted downwardly into the lock 10, or the lock 10 can be mounted "upside-down" in the upper portion of the door, and the key 44 inserted upwardly into the lock 10. In either such mounting, the body shell member 22, through which the expanded tip end 54A is exposed, is placed against the door frame so as to cover the tip 54. In such usage, the screws 20 have unidirectional heads, which prevent unscrewing the screws, so as to remove the lock 10 from the door 12 at the installation. Conventional locks of this type, such as the lock shown in U.S. Pat. No. 4,163,375, are not designed for such use.
A further advantage of the lock 10 with respect to conventional locks is that the barrel lock 34 may be removed from the lock 10 and a new barrel lock substituted therefor. Such a feature is of particular advantage when it is desired to install a plurality of locks 10 in a residence, for example, without the necessity of the user having multiple different keys in order to operate the various locks. In order to provide for such a feature, the barrel lock 34 has a spring biased retainer leaf 90 (see FIG. 2) which is normally biased outwardly to retain the barrel lock 34 in the housing 36 by engaging an inner circumferential groove formed in the housing 36 and which opens into the slot 86, so that both the retainer leaf 90 and locking cam 38 (when retracted) may rotate within the housing 36 upon rotation of the barrel lock 34. The housing 36 has a small passageway 92 (FIG. 6) extending therethrough so as to open onto the retainer leaf 90 when the barrel lock 34 is in its unlocked position. The lock case 25 has a pair of holes 94, 96 formed at the junction of the shells 22, 24 so as to be in alignment with the passageway 92 when the barrel lock 34 is either unlocked or extended. When the lock 34 is in its extended position as shown in FIG. 4, the passageway 92 in the housing 36 is aligned with the case hole 96. When the lock assembly 28 is in the retracted position as shown in FIG. 6, the case hole 94 is in alignment with the passageway 92. In either such alignment, a small rod 98 may be inserted through the respective one of the case holes 94, 96 and the passageway 92 so as to depress the retainer leaf 90 into the barrel lock 34 when and only when the barrel lock 34 is in its unlocked position with cam lug 38 retracted in the barrel lock housing 36, thereby permitting the lock 34 to be withdrawn from the housing 36 by pulling on the key 44. Identically keyed new barrel locks 34 may then be inserted into the desired number of locks 10, so as to provide the identically keyed feature for the user without the necessity of taking the lock 10 apart, which would destroy the lock 10 in view of the expanded end of the tip 54A which holds the two shell members 22, 24 of the case 25 together. | 4y
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TECHNICAL FIELD
This application relates to a mechanism and method for precisely arranging the optical axes of two or more optical elements, such as those incorporated into photoelastic modulators, in a selected angular orientation.
BACKGROUND
A photoelastic modulator (PEM) is an instrument that is used for modulating the polarization of a beam of light. A PEM employs the photoelastic effect as a principle of operation. The term “photoelastic effect” means that an optical element that is mechanically stressed and strained (deformed) exhibits birefringence that is proportional to the amount of deformation induced into the element. Birefringence means that the refractive index of the optical element is different for different components of a beam of polarized light.
A PEM includes an optical element, such as fused silica, that has attached to it a transducer for vibrating the optical element. The transducer vibrates at a fixed frequency within, for example, the low-frequency, ultrasound range of about 20 kHz to 100 kHz. The mass of the element is compressed and extended along the axis of the optical element as a result of the vibration. The combination of the optical element and the attached transducer may be referred to as an optical assembly. The axis about which the optical element vibrates is referred to as the optical axis of the PEM.
The optical assembly is mounted within a housing or enclosure that normally includes an aperture through which the light under study is directed through the optical element in a direction generally perpendicular to the optical axis of the PEM. The enclosure supports the optical assembly in a manner that permits the optical element to be driven (vibrated) within it to achieve the above-noted photoelastic effect.
PEMs are commonly used in measuring polarization properties of either a light beam or a sample. Many instruments use two or more PEMs to provide measurements of certain polarization properties. When two PEMs are used in a single instrument, they are typically arranged so that their optical axes are oriented to be precisely 45 degrees apart (as considered in a direction perpendicular to those two optical axes).
Examples of typical, two-PEM instruments include complete Stokes polarimeters, Tokomak polarimeters, and a number of other polarimeters and ellipsometers. When four PEMs are used in one instrument, the PEMs are typically grouped in separate pairs.
The speed and precision with which a pair of PEMs can be oriented so that their optical axes are fixed at a particular, selected angle depends greatly on the precision with which the housing or enclosure to which the PEMs are mounted can be positioned and secured to place the PEMs in that proper orientation.
SUMMARY OF THE INVENTION
The present invention is directed to a mechanism and method for precisely arranging two or more optical elements, such as those incorporated into PEMs, at a specific angular orientation.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top plan view of a mechanism formed in accordance with the present invention, with a cover removed and with an actuator connected thereto for adjusting the mechanism.
FIG. 2 is a cross sectional view of the mechanism taken along line 2 - 2 of FIG. 1 .
FIG. 3 is a perspective view of the mechanism of FIG. 1 with the cover replaced and the actuator removed.
FIG. 4 is a top plan view of FIG. 3 .
DETAILED DESCRIPTION
One embodiment of a mechanism 20 formed in accordance with the present invention is depicted in the figures. The mechanism 20 includes two generally annular mounting members, hereafter referred to as a lower mounting member 22 and upper mounting member 24 . The designation of “lower” and “upper” is for reference purposes only. The mounting members 22 , 24 are nearly identical in construction and are interchangeable. The following description focuses on the upper mounting member 24 with the understanding that the lower mounting member 22 is similarly constructed except where otherwise specified.
The upper mounting member 24 is metal and is generally annular with a depth (measured vertically in FIG. 2 ) that is about one-half of its radius (as measured in a plan view). A notch 26 ( FIG. 1 ) is cut through the mounting member 24 . An open end of a somewhat elongated enclosure 28 is attached to the mounting member at the notch 26 to protrude radially outwardly therefrom. (The corresponding enclosure of the lower mounting member 22 is shown at 128 .) It is noteworthy that the mounting member may also be formed of rigid plastic, such as Delrin®. This would be a useful configuration when the mechanism is used in a magnetic field as occurs, for example, in Tokomak polarimeter applications.
A primary function of each mounting member 22 , 24 is to support the optical assembly of a photoelastic modulator (PEM) 30 . The primary components of the PEM's optical assembly include an optical element 32 formed of fused silica. Other material, such as fused quartz, calcium fluoride, zinc selenide, silicon and others may be used to form the optical element. (The corresponding optical element supported in the lower mounting member 22 is shown at 132 .)
The optical element 32 is a generally square-shaped member but having beveled corners that define flat support surfaces 34 , the function of which is described below. The optical element also has an entry surface 36 against which an incident light beam is directed while the PEM is operating. A quartz piezoelectric transducer 38 ( FIG. 1 ) is bonded to one of the four sides of the optical element 32 . Electrical leads (not shown) from the transducer are connected to a driver circuit for vibrating the optical element 32 .
The optical element 32 is supported so that its entry surface 36 extends across the central aperture 40 of the upper mounting member 24 . Preferably, the center of the entry surface is aligned with the central axis 41 of that aperture 40 ( FIGS. 2 and 3 ). The optical element 32 is free to vibrate when driven as described above. In this regard, the optical element 32 is mounted to the upper mounting member 24 by somewhat flexible supports 42 ( FIG. 1 ) that secure the optical element 32 at each support surface 34 so that the optical element is substantially suspended within the central aperture 40 of the upper mounting member 24 .
Each one of the supports 42 includes an elastomeric rod 44 that may be formed, for example, from extruded silicone (polysiloxane) cords that are cut to a specified length to define the rod 44 . One of the two, flat ends of the rod 44 is attached, as by an adhesive, to one of the support surfaces 34 on the optical element 32 .
The other, free end of the rod 44 fits within a sleeve 46 that is carried inside of a cylindrical slider 48 . The sleeve 46 has a cylindrical axial bore formed through one end to receive the elastomeric rod 44 . The sleeve 46 is a rigid, externally threaded member that is threaded into an internally threaded bore 50 ( FIG. 3 ) of the slider 48 .
Each on of the four sliders 48 fits inside of a radial hole 52 ( FIG. 3 ) formed through the curved side 56 of the upper mounting member 24 . The slider 48 , with the sleeve 46 threaded into its bore 50 , is slid with the radial hole 52 until the rod 44 is received in the bore of the sleeve 46 . The slider 48 is secured in place via a setscrew 54 that is threaded vertically ( FIG. 1 ) through the upper mounting member 24 to bear against the slider.
With the slider secured in place, the sleeve 46 is advanced until the free end of the rod 44 (that is, the end not bonded to the optical element support surface 34 ) is completely received within the bore of the sleeve. The sleeve 46 may be advanced by hand or with a tool. In this regard, the outer end of the sleeve 46 may be shaped to define a socket for an Allen-type wrench or the like that can be extended into the bore 50 of the slider to reach the socket in the sleeve 46 .
The foregoing description of an exemplary support 42 applies to all four supports 42 on both mounting members 22 , 24 . As depicted in FIG. 1 , four supports are employed to secure the optical element 32 in place relative to the upper mounting member 24 . The supports are thus arranged in diametrically opposed pairs. Alternative configurations of such supports 42 are contemplated, such as those described in U.S. Pat. No. 7,800,845 owned by the assignee of this application. As another alternative, the rod 44 could be replaced with a glass or plastic conical member with the base of the cone bonded to the support surface 34 and the pointed end seated in the central opening of an annular elastomeric grommet that is mounted on the end of a cylindrical barrel that is secured in the hole 52 . In the figures, the grommet and barrel would appear as the sleeve 46 and slider 48 respectively. The setscrew 54 would hold the barrel and grommet combination in place.
The transducer 38 is attached to the optical element 32 , and not otherwise supported by the upper mounting member 24 . The transducer 38 is an elongated, bar-like member that extends from the optical element 32 and into the enclosure 28 that protrudes radially outwardly from the outer, curved surface 56 of the upper mounting member 24 . The longitudinal axis 58 of the transducer 38 is aligned with the center of the optical element 32 and, as such, this axis 58 coincides with the optical axis of that optical element.
For purposes of this description, the projection of the optical axis of the optical element 32 of the PEM 30 onto the structure of the upper mounting member 24 is illustrated by axis line 58 , which will hereafter be referred to as the optics axis 58 of the upper mounting member 24 . The lower mounting member 22 has a similarly defined optic axis 158 , as shown in FIGS. 1 , 3 and 4 .
The angle between these two optics axes 58 , 158 (as viewed along the central axis 41 (see FIGS. 1 and 4 ) is referred to as the optics angle 60 . It will be appreciated that the optics angle 60 (and the associated adjustments to that angle discussed below) corresponds directly to the angle between the optical axis of the optical element 32 in the upper mounting member 24 and the optical axis of the optical element 132 in the lower mounting member 22 . Any minor variations between those two axes (which may be attributable to, for example, a slight misalignment of the supports 42 that secure the optical elements 32 , 132 in place) can be accounted for as will be discussed below.
As best shown in FIGS. 1 and 2 , each mounting member 22 , 24 , includes three, spaced-apart, elongated guide slots 62 , 162 that, in plan view, are curved about the central axis 41 . The guide slots 62 , 162 are counterbored into the opposite flat surfaces of the upper and lower mounting members 22 , 24 . The counterbored portions 64 , 164 of the guide slots thus provide recesses within which the opposite ends of shoulder bolts 66 are received.
As shown in the figures, the upper mounting member 24 and lower mounting member 22 are stacked together, concentric with the central axis 41 . The guide slots 62 , 162 are precisely, concentrically aligned so that the smooth, shoulder portion 68 of each shoulder bolt 66 fits vertically through the stacked mounting members (See FIG. 2 ) to serve as guide pins so that one mounting member can be precisely rotated relative to the other about the central axis 41 . The head of each shoulder bolt 66 fits inside a counterbored portion 64 . The threaded end of the bolt, to which a flanged nut 70 is fastened, also fits inside of a counterbored portion 164 of the guide slots. The nuts 70 are sized so that they will not rotate with the bolt 66 . When the precise, desired optics angle 60 is established, the shoulder bolts 66 are tightened (as by an Allen wrench applied to the hex socket in the bolt head) to lock the upper mounting member 24 to the lower mounting member 22 , thereby fixing the optics angle.
In a preferred embodiment, the upper and lower flat surfaces of the stacked upper mounting member 24 and lower mounting member 22 are provided with thin cover plates 72 , the uppermost plate being added after the bolts 66 are all tightened. The underside of the radially protruding portion of the enclosure 28 of the upper mounting member 24 has a cover plate 73 , and the upper side of the radially protruding portion of the enclosure 128 of the lower mounting member 22 has a cover plate 75 ( FIG. 3 ).
It is contemplated that once the upper and lower mounting members 24 , 22 are stacked but not rotatably fixed together by bolts 66 , any one of a variety of actuators may be employed for precisely rotating one mounting member relative to the other until the desired optics angle 60 is established. The actuator may be applied to any part of one mounting member to force rotation of that mounting member relative to the other. The actuator can be connected to a work surface adjacent to the rotated mounting member. Alternatively, the actuator can be connected to one mounting member (which member is secured to be stationary) and operable to apply force to the other mounting member. The actuator may be a permanent component of the overall mechanism, or be configured for removal once the precise optics angle is established, and the mounting members locked together. The actuator can be manually operated or mechanically driven under computer control.
In a preferred embodiment, an actuator 74 ( FIG. 1 ) for providing precise rotation of one mounting member relative to the other comprises a fine adjustment screw assembly 76 . That assembly includes and elongated screw 78 , one end of which 80 is rounded and engages an exterior surface of the enclosure 28 that protrudes radially from the upper mounting member 24 ( FIG. 1 ). The screw 78 is threaded through a bushing 82 that is mounted within a base 84 of the assembly. The base 84 (hence the assembly) is connected to the cover plate 75 of the lower mounting member enclosure 128 via fasteners that are threaded into mounting holes 86 ( FIG. 4 ). Rotation of the ultra fine pitched screw is transferred via the contact of end 80 with the enclosure 28 into rotation of the upper mounting member 24 relative to the lower mounting member 22 , which member 22 may or may not be secured in place while this adjustment is made.
As noted above, the angle between the two optics axes 58 , 158 (namely; the optics angle 60 ) that is adjusted as just described corresponds directly to the angle between the optical axes of the optical elements 32 , 132 in the respective upper mounting member 24 and lower mounting member 22 . Any minor variations between one optic axis 58 , 158 and the corresponding optical axis of the associated optical elements 32 , 132 (which variations may be attributable to, for example, a slight misalignment of the supports 42 securing the optical elements 32 , 132 in place) can be addressed while the mechanism 20 is located in an optical setup with light passing though the optical elements of both PEMs and detected. This approach can be referred to as the PEMs optical angle calibration.
One approach to this calibration is schematically depicted in FIG. 2 , where the mechanism 20 is part of a setup that includes a light source 86 , adjustable polarizer 88 , an adjustable analyzer 90 , photodetector 92 and an associated lock-in amplifier 94 . The procedure discussed next is for precisely establishing the angle between the optical axes of the two PEMs to be 45°, although other angles may be selected.
The polarizer 88 is set at 0° and the analyzer 90 is set at 45°. The upper mounting member 24 is rotated as described above until the optics axis 60 is at 45°. This angle can be measured in any of a number of ways, including the use of angular graduations on the exposed, adjacent surfaces of the mounting members. Next, the PEM 30 in the upper mounting member 24 is operated at a peak retardation of one-half wave while the PEM in the lower mounting member 22 remains off. The 2F signal on the detector 92 is monitored using the lock-in amplifier 94 . The mechanism 20 is then employed to precisely rotate the upper mounting member 24 relative to the lower mounting member 22 until the 2F signal reads “0,” at which point the upper mounting member 24 and lower mounting member 22 are locked together using the shoulder bolts 66 as described above.
While the foregoing description was made in the context of a preferred embodiment, it is contemplated that modifications to the embodiment may be made without departure from the invention as claimed. For example, it is contemplated that the preferred embodiment of the actuator 74 may include the application of a spring or latch member extending between the adjustment screw and enclosure 28 so that the enclosure will move with both the extension and retraction of the adjustment screw 78 . Further, the actuator may be configured to act on any portion of the mounting members to impart the relative rotation, such portions can be considered protrusions but need not be the radially protruding enclosures discussed above. | 4y
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RELATED APPLICATIONS
[0001] This application filing is a very particular extension of studies carried out over the last three years for the use of the chemistry and elastic deformation effects of materials that are also stabilized by an electronic information loop. Priority is claimed in PCT publication PCT/FR2009/000259 titled Electronic Organization For Dynamic, Chemical And Mechanical Performance.
[0002] This publication provides the generality of the functions of an electronic component referred to as an eCRT probe. The eCRT probe operates based on three simultaneous activities having novel applications.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0003] The medium of the application is a pertinent, but non-exhaustive, exemplary embodiment that shows perfectly the circumstances in which the present application is useful.
[0004] In FIG. 3 , a wheel with a tire 5 rolls over a road 4 having an uneven or irregular profile. The wheel supports the mass 6 to be transported and the driving force is the force 2 that is exerted on the axle of the wheel in order to obtain the reaction 3 of the force advancing the tire on the road. The shock absorber 1 undergoes all the rebound reactions of the tire which acts as a balloon on the road, maintained by the mass to be transported plus the torque of the power to be transmitted by the elasticity of the tire which transfers the force from the axle of the wheel to the roadway, i.e., the driving force of the mass 6 to be transported. In short, the rolling tire transfers all the mass and power forces and accepts the deformations in the ground.
[0005] In addition, the tire must be balanced with respect to its own distribution of the masses, thereby excluding the dynamic reality as a real function which is much more complex than simple balancing. Balancing does not take account of the deformation of the tire and of its internal tensile forces between the tread and the sidewalls that transpose the power forces, the braking forces, the deformations in the road and the mass to be transported. The forces for translating the driving stability of the masses during acceleration and braking are very high tensile forces and compressive forces, which are born by the structures and the structure of the rubber compounds employed.
[0006] These tensile and compressive forces result in movements of intense magnetic charges, as does any friction of the rubber compounds on the roadway. All these forces are identified by electron fluctuations which are managed by the eCRT technology which captures, absorbs the electrons or immobilizes them or else reflects them as an inverse phase. This tends to immobilize the electrons at the source of the elastic deformations.
[0007] The electronic component undertakes the absorption of the magnetic charges by the metallic material included in the piezoelectric component, which transforms them into an electrical current and eliminates them in the form of mechanical vibrations. This is one of the features of the eCRT that we know, but which is applied differently in the specific context of the present application because of an additional stress.
[0008] The function is identical in a particular usage of the tire in action, the apparatus cleans the magnetic charge which is captured by the metal filler contained in the piezoelectric material. By introducing copper, gold, iron or metal powder into the piezo, it is possible to convert the magnetic charge into an electrical charge which is immediately transformed into mechanical movements. The metal may be in the form of small coils of a few turns in order to pick up the radial magnetic field and transform it into an electrical current.
[0009] Through experimentation, we have operated with metal powder or aluminum powder and, depending on the concentration, we raise the relatively intense piezoelectric activity by the electrical charge acquired in the powders or the loops or in both. A mini-coil with the powder allows the effects to be optimized. However, a winding operation necessitates a specific amplitude and frequency. The powder with a certain density and concentration in the mixture of the paste of the piezo makes it possible to receive much more current in terms of frequency and of amplitude, without being specially tuned. This is the case of vibration resolution and complex dynamic balancing of wheels and tires.
[0010] The powder makes it possible to have an overall holistic effect, sensitive to all the magnetic charges operating around the electronic component in the tire, less specific but generally more sensitive depending on the fields of application. The two technologies make reference to low bond energies and to van der Waals dipoles, and Laplace, Hertz, Lorentz, Gauss, Maxwell and Faraday laws. The eCRT (electron converter real time) applications show a product with multiple applications that are generated by the eCRT component, three general functions of which are indicated.
[0011] This balancing is that of naturally cleaning the excess magnetic charges appearing around and in the wheels and by the tires or in the products having undergone excess mechanical deformation stresses which are then absorbed, attracted, captured by the trap of the metal powder components contained in the piezo structure. Nanotechnology makes it possible to see the migration of electrons and associated magnetic fields, which are converted into electrical current which the piezo uses to vibrate.
[0012] These functions are all natural but, combined together, they create novel functions specific to this method. This nanotechnology vision makes it possible to solve on a large scale hitherto difficult problems by means other than conventional ones which give us complete results by novel diagnostic, identification and available energy management approaches. The complex balancing within the material, such as the rubber compounds of tires, becomes possible by the use of three functions and three actions of the added piezoelectricity of metal powder:
1. Magnetic field captured by a metal loop and/or metal powder; 2. Magnetic field transformed into electrical current; and 3. Electrical current transformed by the piezoelectric into mechanical vibration.
[0016] These three phases characterize the eCRT electronic component. The functions are instantaneous, simultaneous, and natural.
[0017] This electronic component is a novel generation of the possible treatment of the generation of self-induced currents of a mechanical nature and of an electromagnetic nature, bearing in mind that a wheel, when rolling by its aluminum or metal rim and by its radii is considered as a Barlow or Telma wheel. These electronic vibration management functions are possible as they are all based on the electronic edifice which is stressed and shaken by the mechanical stresses, and all the structures are involved, and by chemical, mechanical, fluid and gaseous stresses. In a wheel and a tire, all these electromagnetic applications are concerned. All the technical fields are in dynamic phase because the unique edifice of the material composed of electrons is involved in the functions of the mechanics, and of the gases, are concerned.
[0018] These functions stem from the use of servocontrol of the mechanical vibratory and electronic undulatory performance and relate to the use of mechanics, solids, fluids and gases. It involves the active actors, like mechanical ones, and equally the transported or transformed objects being reservoirs of passive electron charges. All industrialization is concerned by the circulation of electrons agitated by mechanical actions under multiple stresses, which tires or vehicle suspensions represent, for example.
[0019] In the eCRT automatic servocontrol, one function is to combat any electron accumulation generated by all the mechanical stresses. The eCRT tendency is to stop this electromagnetic fluctuation resulting from the deformation of the rubber compounds by the mechanical stresses and the friction of the road. This is done by stabilizing the fluctuating electronic state. The eCRT thereby stabilizes the constant, fluid-rendered movement states of the material and the dynamic conditions that the moving mechanical parts, such as the tires and wheels undergo, and become harmonious without any vibration.
[0020] The build-up of a certain electrical potential, which varies depending on the driving, the mass of the vehicle and the road, is discharged, and absorbed by the eCRT. This tends toward a stabilized potential, which constitutes the essential point of automatic servocontrol of the balancing of the wheels by this eCRT apparatus having three instantaneous functions. The balancing potential is, in this application, complex, instantaneous, and is performed on all the interacting forces.
[0021] Finally, this stabilization is an excellent approach to the various stopped and regulated agitations. The highly reactive eCRT blocks the natural activities of the electrons as soon as they arise, thereby definitively stopping any vibratory movement and of associated electrons fleeing the movements. Lenz's law keeps the structure of the tires stable. This overall stabilization effect of the forces, and not only that of the balancing of the mass of the tire, is obtained by including the free eCRT apparatus in the inside of the tire when mounted on the rim, without thereafter performing conventional balancing of external mass.
[0022] This natural reactivity of absorbing the electromagnetic charges and also this eCRT counter-reactivity action to each of the forces generated on the tire can be exerted only if there is a reference memory of a known state which serves as reference for the stable condition. Without memory, there would be no reactivity exactly proportional, in an inverse phase, to the intensities and amplitudes of the imposed mechanical forces which finally, for the same reasons, are automatically stabilized.
[0023] This is because the initial aim of the electrons was to oppose the movements of mechanical stresses, which by means of the eCRT becomes effective and is a mechanical self-management of the calmed deleterious effects of all the attacks by the mechanical stresses. The result is an absence of rolling noise and absolute comfort, which erases all the tensile forces and agitation forces while the vehicle is running.
[0024] This first mode of regulating the balancing which is solved with the eCRT is that of the elastic deformation of the materials where the migration of the electrons is greatly attenuated, making the tires stable, and here a purely mechanical second stress occurs, which is to be resolved which is the modification of the radius of the tread ( FIG. 2 ). This second mechanical stress is the periodic deformation of the tire 5 in contact with the road 4 . A wheel 7 with a tire 10 rotates about a radius 20 that becomes a smaller radius 40 , thereby causing at each revolution of the wheel a shock on the eCRT apparatus 50 , and which jumps at each passage.
[0025] An attenuation of the shock wave, upon reduction in the radius as the eCRT passes over the ground, is obtained using an encapsulation made of silicone gel that accepts the deformation and the passage of the modified eCRT 50 without damage. The silicone gel encapsulation absorbs the difference in radius. This problem also solves the passage over bumps on uneven roads. The wheel, moved by the rim 7 , rotates in a desired direction 60 .
[0026] There are two mechanical stresses to respond. On the one hand there is the overall forces due to the traction, braking and mass of the vehicle and to the profile of the road. On the other hand, there is the partial predictable periodic deformation of the tire on the road. The eCRT is mounted in a very elastic encapsulant, contained in a pouch or envelope made of a very soft rubber polymer or even an impermeable fabric, so as to absorb the elastic deformation of the tire along the radius 40 . The radius 40 represents overall the contact sector of the wheel via which the road-holding and accelerating or braking forces are transferred.
[0027] Sachets or envelpoes of silicas are placed in truck tires for balancing, but this remains very insufficient because of absence of management of the electromagnetic and mechanical stresses of the periodic effects which endlessly reject the sachets. This is even when being inert because of their structuring in sand, with no rebound effect.
[0028] Our arrangement of the present method takes the example of an egg which, when it is not cooked, absorbs any type of vibration by a density-differentiated double structure, represented by the yolk and the white of the egg. FIG. 1 shows a non-exhaustive embodiment of the method for the complex balancing of a wheel that includes many notions of actual mechanical stresses, which are never addressed. The shell keeping the two structures together, like the very flexible envelope 45 , which encapsulates the silicone 35 , or the envelope where the silicone is molded, which itself molds the two illustrated eCRTs 12 , 14 . There are two eCRTs in order to distribute the shock deformation forces.
[0029] It would have been possible to fit five eCRT balls. This arrangement makes it possible to dissipate the regular shock waves, which increase with speed, that the rolling of the tire on the road causes. The shocks break the solid structures of the piezoelectricity, structures of which are all crystalline, and therefore are brittle and would break.
[0030] The apparatus thus consists of two components, one rigid—the piezoelectric structure eCRT—and the other a very soft, or amorphous, paste structure, made of any type of polymer, which makes it possible for complex balancing problems to be fully solved. The balancing problems are mechanical force interactions that generate electron fluctuations according to stable and known relationships, elastic deformations of the materials and piezoelectric effects.
[0031] In the field of traditional mechanics, which in reality focuses on the same structure and a measurement, wherein the other functions of the same structure that serve for several simultaneous functions are forgotten. In regards to the apparatus, the envelope must, while still being flexible in this case, be able to be housed where the vibrations are strongest. This is because the apparatus is free in the tire. The results in terms of comfort are surprising.
[0032] Tests show that the driver of the vehicle is no longer subjected to the tire vibrations and experiences silent, fluid and almost effortless driving. Indeed, all the opposing mechanical stresses are greatly reduced, thereby freeing the steering wheel therefrom, reducing noise and providing unexpected comfort. The elastic balloon that forms the jumping tire is no longer subject to alternations of uncontrolled movements and really grips the road. It is quite clear that driving in the rain is excellent and that braking and safety are greatly improved.
[0033] The fatigue threshold is greatly delayed. Different applications involving complex problems in mechanics or hydraulics on industrial machines or engines may find, thanks to this method, reliable solutions and more stable operation. This method is one for self-stabilizing complex stresses, of a kinetic mechanical order or for management of gases and liquids in the industrial world. This novel self-regulating technique demonstrated by nanotechnology is a great step forward in addressing known problems that have remained without a true solution, or problems that were seen only from a static standpoint, in which only one factor was taken into account.
[0034] The apparatus has a weight of 50 grams for a piezo value with 30 grams of active components. The values are lower for a motorcycle, a small car or a bicycle. Applications on helicopters may be solved with sensitive stations or be diagnosed by the measurement of the roaming electrons following large mechanical stresses which agitate them, by specific elastic deformations. | 4y
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This application is a continuation of U.S. application Ser. No. 11/765,538, filed on Jun. 20, 2007, now U.S. Pat. No. 7,731,102, which claims priority to U.S. Provisional Patent Application No. 60/815,822, filed on Jun. 22, 2006 each of which is incorporated herein by reference in their entirety. This application is also related to U.S. application Ser. No. 11/333,499 filed on Jan. 17, 2006, titled “Porous Composite Materials Comprising a Plurality of Bonded Fiber Component Structures,” which is also incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
The present invention is generally directed to wicks. In particular, it is directed at wicks where the capillary is formed by fibrous materials. More particularly, the present invention is directed to composite bonded fiber wick structures that displace a specific amount of fluid relative to an amount that is initially absorbed.
It is known in the art to manufacture isotropic wicks for a variety of applications. Such isotropic wicks are generally three-dimensional, porous, bonded fiber elements that may serve to wick a fluid from a first location to a second location. These wicks may be used in diverse applications, such as in air freshener devices, lighters, writing instruments, and for a variety of biological fluids, such as urine and/or blood. Such wicks are disclosed in U.S. patent application Ser. No. 11/333,499, which is herein incorporated by reference in its entirety.
When such bonded fiber wicks are used in air freshener devices, the wick is often immersed in a fluid (typically containing a fragrance), and by capillary force the fluid is drawn into the bulk of the wick. Generally, the end of the wick opposite of the end immersed in the fluid is exposed to air, and the fluid may evaporate from the surface of the wick broadcasting the fragrance into the space around the air freshener device.
However, isotropic wicks used in such air freshener devices and similar applications have several drawbacks. One of the more significant drawbacks is that when an isotropic wick is used to dispense volatile air freshener solutions, the wick generally absorbs an amount of air freshener solution when it is placed in the container. When the wick has a large volume relative to the volume of the container, this may cause the level of liquid in the container to drop as it is absorbed into the wick. In transparent devices sold into the consumer market, such as an air freshener container made of glass or clear plastic, this often creates the negative perception that the consumer is buying a less than full container of air freshener.
Although a smaller diameter wick may at least partially resolve this problem, the surface area of the wick is reduced due to the smaller diameter, and the dissemination of fragrance may be impaired as a result of less surface area of the wick for evaporation.
Accordingly, there is a need for a wick that initially provides a desired amount of fluid displacement while providing sufficient wick surface area for fragrance dissemination. There is also a need for a wick that displaces an amount of fluid approximately equal to the amount of fluid it initially wicks, resulting in a neutral displacement.
SUMMARY OF THE INVENTION
Aspects of the invention include an air freshener device that emits fragrance through the evaporation of a fragrance-containing fluid comprising: a container, comprising a particular volume of the fragrance-containing fluid; a wick disposed partially in, and partially out of the fragrance-containing fluid, the wick having an immersion section immersed in the fluid and an non-immersion section extending outward from a surface of the fluid, the immersion and non-immersion section being disposed on opposite lateral ends of the wick; the wick further comprising a displacement portion and a wicking portion, the displacement portion being configured to displace a desired first volume of fluid, the wicking portion being configured to wick a second volume of fluid; the displacement portion and the wicking portion designed to achieve a desired ratio between the displaced first volume of fluid and the wicked second volume of fluid.
It is to be understood that both the foregoing and the following description are exemplary and explanatory only, and are not restrictive of the invention. The accompanying drawings, which are incorporated herein by reference, and which constitute a part of the specification, illustrate certain embodiments of the invention and, together with the detailed description, serve to explain the principles of the invention.
DESCRIPTION OF THE DRAWINGS
In order to assist in the understanding of the invention, reference will now be made to the appended drawings, in which like reference characters refer to like elements. The drawings are exemplary only, and should not be construed as limiting the invention.
FIG. 1 depicts an isometric view of a multi-component three dimensional bonded fiber wick in accordance with some embodiments of the present invention.
FIGS. 2-5 each depict a cross-sectional view of a multi-component three dimensional bonded fiber wick in accordance with some embodiments of the invention.
FIG. 6 illustrates an isotropic wick as known in the prior art before introduction to the fluid reservoir.
FIG. 7 illustrates an isotropic wick as known in the prior art directly after introduction to the inside of a fluid reservoir.
FIG. 8 illustrates a neutral displacement wick before introduction to the fluid reservoir, in accordance with some embodiments of the present invention.
FIG. 9 illustrates a neutral displacement wick directly after introduction inside of the fluid reservoir, in accordance with some embodiments of the present invention.
FIG. 10 illustrates an improperly configured wick directly after introduction inside of a fluid reservoir.
FIG. 11 illustrates a manufacturing process of producing neutral displacement wicks in accordance with some embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
A neutral displacement wick (NDW) in accordance with some embodiments of the present invention will now be discussed. The advantage of a NDW wick when used in air freshener devices or similar applications is that when the wick is first introduced into the fluid reservoir, it may absorb a desired amount of liquid into the wick relative to the amount it displaces, resulting in the liquid level in the fluid reservoir remaining at or near the level present before the wick was introduced, or at some other desired level. If the wick is capped off or otherwise enclosed to prevent evaporation, the device may be shipped to the consumer who may then have the perception that he or she is buying a full container. When the cap is removed, the large surface area of the wick sheath may allow dissemination of fragrance.
With reference to FIG. 1 , a multi-component NDW wick 10 may comprise at least four (4) non-discrete (i.e., overlapping) portions: an immersion section 110 , an non-immersion section 120 , a displacement portion 130 , and a wicking portion 140 . The immersion section 110 and the non-immersion section 120 divide the wick laterally, while the displacement portion 130 and wicking portion 140 provide radial divisions in the wick 10 . The immersion section 110 is the section of the multi-component wick that is initially in the fluid. The non-immersion section 120 is the section of the multi-component wick that is initially outside of the fluid. The displacement portion 130 may run the entire length of the wick, or may be primarily disposed in the immersion section 110 . While the displacement portion 130 may possess some wicking characteristics, its primary purpose is to initially displace a specified amount of fluid. The wicking portion 140 may also run the entire length of the wick, although it is also contemplated to have the majority of the wicking portion 140 in the non-immersion section 120 of the wick. The surface area of the wicking portion 140 in the non-immersion section 120 will determine the dissemination rate of the evaporated fluid.
With reference to FIGS. 2-5 , various cross-sections of a NDW will now be discussed. In FIG. 2 , a NDW 20 may be configured in a cylindrical shape, and may comprise a displacement portion 210 and a wicking portion 220 . The displacement portion 210 is shown as being radially-internal to the wicking portion 220 . In this manner, the displacement portion 210 may not only be generally hidden, but the wicking portion 220 may be fully exposed to the ambient environment, thereby allowing for optimal evaporation, and thus, fragrance dissemination.
In FIG. 3 , a NDW 30 may again be comprised in a cylindrical shape and may comprise a first wicking portion 310 , and a second wicking portion 320 . The NDW 30 may also comprise an impervious membrane 340 and a void area 350 . It is contemplated that the void area 350 may be used similar to the displacement portion in FIGS. 1 and 2 to displace a desired amount of fluid. The first wicking portion 310 may be designed to wick a specific material (e.g., it may be hydrophilic) while the second wicking portion 320 may be designed to wick a different specific material (e.g., it may be oleophilic), providing for multiple scents emitting from the NDW 30 . Additionally, the first and second wicking portions 310 , 320 may wick the same materials at different rates, or either the first or the second wicking portion 310 , 320 may have aromas embedded therein.
In FIG. 4 , a NDW 40 may be rectangular in cross-section, and may comprise a displacement portion 410 and a wicking portion 420 . Similarly, in FIG. 5 , a NDW 50 may comprise at least three (3) portions: a first wicking portion 510 , a second wicking portion 520 , and a displacement portion 530 . Alternatively, the NDW 50 may comprise a wicking portion and a displacement portion separated by an impervious membrane.
Other example cross sections may be a wicking core and a non-wicking sheath, or any other configurations that would be obvious to one skilled in the art.
Many materials may be used in the wicking portion of the NDW wick. Such materials may be self-sustaining porous bonded fiber elements that are well known to be able to be engineered to wick a variety of liquids and act as air freshener wick materials. Examples of such materials may include bonded bicomponent polyolefin sheath fibers, bonded bicomponent polyester sheath fibers, bonded bicomponent nylon sheath fibers and bonded pneumatic nylon and pneumatic cellulose acetate.
Other examples of materials that may be suitable for use in the wicking portion of the NDW wick may include porous, non-bonded, wicking fiber elements, which may be stiffened by adhesives or otherwise made structurally sound to enable consistent wicking behavior. Woven, knitted or non-woven fabrics may be used, as well as natural fibrous or non-fibrous products (such as cotton or wool). In addition, open cell foams may be used (as long as they are of sufficient surface energy to allow wetting and wicking of the target fluid). Additionally, porous plastics, such as self-sustaining porous sintered plastic elements, may be used. Various other materials that provide adequate wicking and evaporation will be readily apparent to one skilled in the art.
In general, the non-wicking portion may be any material as long as it is so configured so that the target fluid will substantially not penetrate this portion and thus be displaced by the non-wicking portion. The non-wicking portion of the NDW wick may be impervious, and may be a closed cell foam material, such as a rod-shaped chemically resistant polyethylene or polyurethane foam, a solid rod, such as a variety of plastic or elastomeric rods, or even rods of wood or metal. The non-wicking portion may also be bonded or non-bonded fiber structures, or natural product structures, with the surface energy being such that the material would not wet out or wick the target fluid, even under elevated pressure conditions that may be experienced in a container.
The wicking portion may be tight up against the non-wicking displacement portion to prevent voids from forming. Unsealed voids are unwanted because upon filling with the fragrant liquid, the volume of the container may appear to be less. The wicking portion and the non-wicking displacement portion may be arranged so as to prevent unwanted delamination or separation of the two portions. For example, the wicking portion and the non-wicking displacement portion may be combined into a single unit by interference fit, or may be adhered together. Such adherence may be the result of fibers of the wicking portion bonding to the non-wicking displacement portion, or may result from the use of adhesives applied to the components.
In general, the wick may be sized to achieve the following objectives:
1. The proper surface area (as determined by the circumference of the wick, the amount of wick exposed in the non-immersion section, and the vapor pressure of the target fluid). A proper surface area may allow a vapor release rate appropriate to the application in question. 2. Appropriate volume of liquid wicked up into the wick by capillary action (determined by the cross sectional area of the wicking portion, plus the capillary draw and porosity of the porous element). 3. The amount of liquid displaced (determined by (2) above plus the displacement of the displacement portion). 4. A desired relationship between the immersion section and the non-immersion section. For example, in some circumstances, it may be desirable to maintain a fluid level at the same height once a wick is inserted. In this situation, the initial volume of the immersion section (comprising the volume of both the displacement portion and the fiber volume of the wicking portion) should be approximately equal to the initial volume of fluid wicked by the wicking portion located in the non-immersion section. In other circumstances, it may be desirable to cause the fluid level to rise or drop once a wick is inserted. In such circumstances, the volume of the immersion section may initially be more or less, respectively, than the volume of fluid initially wicked by the wicking portion in the non-immersion section.
The need for proper sizing of the NDW wick may be apparent from FIGS. 6-10 . In accordance with some embodiments of the present invention, FIGS. 6-10 illustrate the proper sizing for a NDW where the immersion section displaces an amount of fluid approximately equal to the amount fluid wicked into the wicking portion of the non-immersion section (note that the fluid level remains the same throughout). FIGS. 6 and 7 illustrate the undesirable effect of initial liquid drop in a fluid reservoir when a standard, non-NDW wick is used. It is desirable to properly size or configure an NDW wick to prevent similar fluid drops. FIGS. 8-9 illustrate a properly sized NDW wick that displaces an equal amount of liquid as it initially absorbs, maintaining the initial fluid level at approximately the top of the bottle. FIG. 10 illustrates an improperly sized wick that displaces more fluid than it absorbs, resulting in fluid overflow upon insertion.
The ratio of the volume of liquid displaced by the immersion section (including the displacement portion) to the volume of liquid initially wicked into the wicking portion in the non-immersion section must be designed for each particular application, and must take into account the volume of the container, the size of the NDW and the desired liquid height inside the container before and after the insertion of the NDW. Ratios may range from 0.2 to 4.0. When a particular fluid level prior to NDW insertion is desired to be maintained after NDW insertion, ratios may range from 0.95 to 1.05. Design considerations include, but are not limited to, the desired evaporation rate of the liquid, the surface tension of the liquid that is to be wicked, the density of the wicking portion, the overall dimensions of the wicking portion, and the overall dimensions of the container.
NDW may also be made in many different ways, including bonded fiber processes of many types, non-woven wrapping technologies, textile technologies, and a variety of forming technologies. NDW may be produced by separately manufacturing the porous, wicking portion and the non-wicking portion, and combining the portions into a final unit. As noted above, this combination may utilize an interference fit, may be thermally bonded together as part of the forming process or may utilize additional adhesives.
Alternatively, the wicking portion may be formed integral to the displacement portion. For example, in arrangements such as those depicted in FIGS. 2 , and 3 wherein the wicking portion surrounds the displacement portion the wicking portion may be formed around and integral to, the displacement portion, or, in the case of FIG. 3 , around a sealed void that provides the desired displacement.
With reference to FIG. 11 , one manner of producing NDW in accordance with some embodiments of the present invention will now be discussed. The displacement portion 1110 may be already formed. The displacement portion 1110 may comprise any material that does not wick or wet out with the intended liquid. For example, the displacement portion 1110 may be a solid, a closed cell foam such as a chemically resistant polyethylene or polyurethane foam. Although the geographic arrangement of the displacement portion 1110 is illustrated in FIG. 11 as being cylindrical, it may take any desired cross-section. The wicking portion 1120 may be formed from a fibrous sheet into a three dimensional, self-sustaining structure around the displacement portion 1110 . Sheets or webs of fibrous material 1120 may be fed around the displacement portion 1110 to wrap or encase it. The encased combination of the fibrous material 1120 and the displacement portion 1110 may be fed into a heated die 1130 . The die 1130 may be heated by any variety of means (e.g., steam, induction, convection, etc.) and may maintain a temperature above the softening temperature of the fibers of the wicking portion 1120 . If the wicking portion 1120 is comprised of bicomponent fibers (e.g., sheath-core or side-by-side bicomponent fibers) the die 1130 may be maintained at a temperature above the softening temperature of the lowest softening (or melting) temperature component. If sheath-core bicomponent fibers are used, the softening temperature of the sheath will be exceeded by the temperature of the die 1130 . The heat from the die 1130 may cause the fibers to bond to each other at various points of contact. Upon cooling, the wicking portion may be formed into the desired three dimensional, self-sustaining, porous fiber structure.
The inner dimensions of the die may form the combined wicking portion 1120 and displacement portion 1110 into a desired cross section. Optionally, a cooling die 1140 may be used to quicken the cooling of the heated fibers. Additionally, the cooling die 1140 may provide additional shaping of the cross section of the final product. Upon exit from the heating die 1130 and optionally the cooling die 1140 , the NDW 1170 is formed. The combined NDW 1170 may be pulled through the process by element 1160 , and may be cut to desired length by element 1150 . Although FIG. 11 depicts an NDW 1170 in a cylindrical shape with a circular cross section of both the wicking portion and the displacement portion, it is anticipated that any desired cross section may be obtained.
As noted above, FIG. 11 illustrates a single method for the manufacture of a NDW. Multiple other manufacturing methods may be used to produce, either separately or integrally, the wicking portion and displacement portion of the NDW.
It will be apparent to those skilled in the art that various modifications and variations can be made in the method, manufacture, configuration, and/or use of the present invention without departing from the scope or spirit of the invention. | 4y
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CROSS REFERENCE OF RELATED APPLICATIONS
[0001] The present application claims the benefit of the Chinese Patent Applications No. 200610029971.4, filed on Aug. 11, 2006; and 200610117864.7, filed on Nov. 2, 2006, which are incorporated herein by reference in their entirety and for all purposes.
FIELD OF THE INVENTION
[0002] The present invention relates to an energy-effective process for the co-production of ethylene and dimethyl ether.
BACKGROUND OF THE INVENTION
[0003] Ethylene is a very important basic organic chemical raw material. In recent years, as the demand to derivatives of ethylene such as polyethylene quickly increases, the demand to ethylene also increases year by year. At present, ethylene is mainly prepared by steam cracking processes of light petroleum cuts, but other processes for preparing ethylene are paid more and more regard as the prices of petroleum and light petroleum cuts have been rising.
[0004] A promising approach is to prepare ethylene by dehydrating ethanol. In particular, with the quick development of biotechnology, techniques for producing ethanol through biological processes go ahead ceaselessly so that the source of ethanol is ceaselessly extended and the cost of ethanol becomes more acceptable. Many researches on the preparation of ethylene by dehydrating ethanol have been disclosed in literatures. For example, Zhongqing Zhou, Speciality Petrochemicals, No. 1, 35-37, 1993 reports a research on the preparation of ethylene by dehydrating a feed comprising lower concentration ethanol over a 4 Å molecular sieve catalyst. The results show that, when reaction temperature is in a range of from 250 to 280° C., WHSV of the liquid feed is in a range of from 0.5 to 0.8 h −1 , and mass concentration of ethanol in the feed is about 10%, conversion of ethanol may be as high as 99% and selectivity to ethylene may reach 97 to 99%.
[0005] Yunxia Yu, Journal of Chemical Industry & Engineering, Vol. 16, No. 2, 8-10, 1995 reports the preparation of NC1301 Catalyst used for preparing ethylene by dehydrating ethanol. Main active component of this catalyst is γ-Al 2 O 3 . By using this catalyst and under the following conditions: reaction temperature=350 to 440° C., reaction pressure≦0.3 MPaa, and WHSV of ethanol as feedstock=0.3 to 0.6 h −1 , a reaction effluent may contain 97.5 to 98.8% of ethylene.
[0006] U.S. Pat. No. 4,234,752 discloses a process for preparing ethylene by dehydrating ethanol. Said process utilizes an oxide catalyst and achieves a higher conversion of ethanol at a reaction temperature of from 320 to 450° C. and at a WHSV of from 0.4 to 0.6h −1 .
[0007] U.S. Pat. No. 4,396,789 discloses a process for preparing ethylene by dehydrating ethanol over an oxide catalyst, wherein a temperature at a reactor inlet is 470° C., and a temperature at a reactor outlet is 360° C.
[0008] Chinese Patent Application CN 86101615A discloses a catalyst useful in the preparation of ethylene by dehydrating ethanol. The catalyst comprises ZSM-5 molecular sieve, and gives a higher conversion of ethanol and a higher ethylene yield at a reaction temperature of from 250° C. to 390° C., but exhibits a shorter service lifetime.
[0009] Since the reaction of dehydrating ethanol to ethylene is a strongly endothermal reaction, the processes of the prior art for preparing ethylene by dehydrating ethanol suffer generally from lower space velocity of feedstock, higher energy consumption, difficulties associated with reactor enlargement, etc.
[0010] Dimethyl ether is a jumped-up basic chemical raw material and finds specific uses in applications such as pharmacy, fuel, pesticide, and the like. Dimethyl ether has a great application prospect as a clean fuel. Furthermore, dimethyl ether may be converted to light olefins through oxygenate-to-olefin processes.
[0011] Dimethyl ether is typically produced by the reaction of dehydrating methanol. This reaction is an exothermal reaction so that a large amount of heat has to be removed during the reaction.
SUMMARY OF THE INVENTION
[0012] The inventors have found that the reaction of dehydrating ethanol to prepare ethylene and the reaction of dehydrating methanol to prepare dimethyl ether may be well coupled, and thus an energy-effective process for the co-production of ethylene and dimethyl ether may be provided. This process has the following advantages: reaction temperature is lower, energy consumption is lower, the enlargement of reactor is easy, and operation is simple.
[0013] Thus, an object of the invention is to provide a process for the co-production of ethylene and dimethyl ether, comprising the steps of
[0014] (i) providing a feedstock comprising ethanol and methanol, with a weight ratio of methanol to ethanol being in a range of from 1:10 to 10:1;
[0015] (ii) feeding the feedstock into a reaction zone containing a solid catalyst to give an effluent, wherein a reaction temperature is in a range of from 200 to 480° C., a reaction pressure is in a range of from 0 to 2 MPa (gauge), and a weight hourly space velocity of the feedstock is in a range of from 0.1 to 10 h −1 , and wherein the solid catalyst is selected from the group consisting of alumina catalysts and crystalline aluminosilicate catalysts, and
[0016] (iii) isolating ethylene and dimethyl ether from the effluent from step (ii).
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] In the process according to the invention, ethanol is dehydrated under the action of the solid catalyst to form ethylene:
[0000] CH 3 CH 2 OH→CH 2 =CH 2 +H 2 O,
[0000] and methanol is dehydrated under the action of the solid catalyst to form dimethyl ether:
[0000] 2CH 3 OH→(CH 3 ) 2 O+H 2 O.
[0018] It is well known that the dehydration of ethanol is a strongly endothermal reaction. In the case where pure ethanol is fed, a temperature drop in an adiabatic reactor is about 400° C. Therefore, in fixed bed processes for preparing ethylene by dehydrating ethanol, a shell and tube fixed bed reactor or a multistage fixed bed reactor is generally employed. If a shell and tube fixed bed reactor is employed, for a large scale process for preparing ethylene by dehydrating ethanol, there are problems relating to engineering enlargement and equipment manufacture. Although a multistage fixed bed reactor may maintain the used catalyst in a suitable operation temperature range by supplying heat at a position or positions between the stages, the presence of a larger temperature gradient in the catalyst bed results in that the catalyst cannot function best and that the perfect selectivity to ethylene is hardly achieved. Furthermore, the two kinds of reactor suffer from a common problem that energy consumption is high.
[0019] The inventors have noted that the reaction of dehydrating methanol to dimethyl ether is a strongly exothermal reaction and is substantially the same as the reaction of dehydrating ethanol to ethylene in reaction condition, the catalyst used, and the sequent isolation system. Thus, the present invention couples the dehydration reaction of methanol and the dehydration reaction of ethanol, and thereby provides a process for the co-production of ethylene and dimethyl ether. Because the two reactions are coupled in situ in heat, there does not need further supplying or removing a large amount of heat. Hence, the process is energy-effective, resulting in that the process flow is simplified, equipment investment is reduced, and the reactor can be easily enlarged.
[0020] There is not a specific limitation to the source of ethanol and methanol used as feedstock in the process of the invention. From the view point of matching reaction heat, the weight ratio of methanol to ethanol in the feedstock may be in a range of from 1:10 to 10:1, preferably from 1:5 to 8:1, more preferably from 1:2 to 6:1, and most preferably from 1:1 to 5:1.
[0021] The catalyst useful in the process of the invention may be selected from the group consisting of alumina catalysts and crystalline aluminosilicate catalysts, which are known by those skilled in the art. The alumina catalysts comprise preferably γ-Al 2 O 3 . Crystalline aluminosilicate catalysts comprise preferably at least one selected from the group consisting of ZSM molecular sieves, β-zeolites and mordenite. In a preferred embodiment, the solid catalyst comprises a ZSM molecular sieve, especially a ZSM-5 molecular sieve, having a molar ratio of SiO 2 to Al 2 O 3 of from 20 to 500, and preferably from 30 to 200. In addition to the alumina or the crystalline aluminosilicate, the catalyst may further comprise a conventional binder.
[0022] The process according to the invention may be carried out under the following reaction conditions: a reaction temperature in a range of from 200 to 480° C., a reaction pressure in a range of from 0 to 2 MPa (gauge), and a WHSV of the feedstock in a range of from 0.1 to 10 h −1 . The reaction conditions may be further optimized according to the selected catalyst. When the solid catalyst is an alumina catalyst, the reaction temperature is preferably in a range of from 300 to 480° C., and more preferably from 350 to 430° C.; the WHSV of the feedstock is preferably in a range of from 0.5 to 5 h −1 ; and the reaction pressure is preferably in a range of from 0.1 to 1 MPa (gauge). When the solid catalyst is a crystalline aluminosilicate catalyst, the reaction temperature is preferably in a range of from 200 to 400° C., and more preferably from 230 to 350° C.; the WHSV of the feedstock is preferably in a range of from 0.5 to 5 h −1 ; and the reaction pressure is preferably in a range of from 0.01 to 1.0 MPa (gauge).
[0023] In an embodiment, at least a part of the obtained dimethyl ether is further converted to olefins, especially light olefins, mainly ethylene and propylene, through an oxygenate-to-olefin process. The oxygenate-to-olefin processes are well known by those skilled in the art. See, for example, CN96115333.4, CN00802040.X, CN01144188.7, CN 200410024734.X, and CN92109905.3.
[0024] The process of the invention allows the reaction to proceed at a lower temperature, for example about 250° C., under a higher space velocity of the feedstock, for example more than 5 h −1 . The reduction of the reaction temperature may markedly lower energy consumption in the operation, aid to reduce side reactions, and lower the rate of catalyst coking to thereby effectively prolong the service lifetime of the catalyst. The enhancement of the space velocity of the feedstock may enhance throughput per unit volume of the reactor. Furthermore, the heat released by the reaction of dehydrating methanol compensates the heat taken up by the reaction of dehydrating ethanol so that a non-shell and tube type monostage adiabatic fixed bed reactor may be employed to carry out the reaction of dehydrating ethanol to ethylene. As a result, the difficulty relating to reactor enlargement is greatly reduced and energy consumption in the operation is further reduced.
[0025] By the process according to the invention, higher conversion of ethanol, for example approximately 100%, higher selectivity to ethylene, for example more than 96%, and higher selectivity to dimethyl ether, for example more than 90%, are achieved.
EXAMPLES
[0026] The following examples are given for further illustrating the invention, but do not make limitation to the invention in any way.
Example 1
[0027] Ten grams of γ-Al 2 O 3 catalyst having a specific surface area of 200 m 2 /g and an alumina content of 99.7 wt. % were charged into a fixed bed reactor having an inner diameter of 22 mm, and then activated in a nitrogen flow at 550° C. for 2 h. After allowing the temperature inside the reactor to lower to reaction temperature, a feedstock consisting of methanol and ethanol (mass ratio of methanol to ethanol=2:1) was continuously fed into the reactor and allowed to react under the following conditions: reaction temperature=360° C., WHSV of the feedstock=1.5 h −1 , and reaction pressure=0.02 MPa (gauge). Effluent of the reactor was analyzed, and it was found that conversion of ethanol was approximatively 100%, selectivity to ethylene was 99.6%, conversion of methanol was 78.1%, and selectivity to dimethyl ether was 98.1%.
Examples 2 to 12
[0028] Experiments were carried out following the procedure as described in the Example 1 under the conditions as set forth in the Table 1 below. The results are shown in the Table 1.
[0000]
TABLE 1
Results
Weight Ratio
Reactor
WHSV of
Reaction
Conversion
Selectivity
Conversion
Selectivity
of Methanol
Temperature
Feedstock
Pressure
of Ethanol
to Ethylene
of Methanol
to Dimethyl Ether
Ex. No.
to Ethanol
° C.
h −1
MPa(gauge)
%
%
%
%
1
2
360
1.5
0.02
100
99.6
78.1
98.1
2
1
380
0.8
0.2
100
96.8
74.3
92.0
3
2
330
4.0
0.05
80.7
90.2
80.8
95.4
4
1/6
400
3.5
0.2
99.8
94.3
53.4
94.7
5
6
450
0.5
1.5
100
88.4
77.2
91.6
6
1/3
370
10.0
0.03
92.4
93.9
60.9
94.1
7
1/2
360
3.0
1.7
100
89.2
69.9
94.6
8
4
380
2.0
0.3
99.5
92.4
72.1
91.0
9
6
360
2.0
0.4
98.7
93.8
76.7
92.3
10
8
400
6.0
0.2
100
88.7
52.5
90.7
11
10
400
4.0
0.15
100
89.6
54.8
91.9
12
1/2
480
8.0
0.5
100
86.1
62.1
88.3
Example 13
[0029] Ten grams of γ-Al 2 O 3 catalyst having a specific surface area of 200 m 2 /g and an alumina content of 99.7 wt. % were charged into an adiabatic fixed bed reactor having an inner diameter of 22 mm, and then activated in a nitrogen flow at 550° C. for 2 h. After allowing the temperature inside the reactor to lower to reaction temperature, a feedstock consisting of methanol and ethanol (mass ratio of methanol to ethanol=1:2) was continuously fed into the reactor and allowed to react under the following conditions: temperature at reactor inlet=400° C., WHSV of the feedstock=3.6 h −1 , and reaction pressure=0.2 MPa (gauge). The temperature at reactor outlet was 328° C. Effluent of the reactor was analyzed, and it was found that conversion of ethanol was approximatively 100%, selectivity to ethylene was 95.7%, conversion of methanol was 80.7%, and selectivity to dimethyl ether was 93.2%.
Example 14
[0030] 10 g of γ-Al 2 O 3 catalyst having a specific surface area of 200 m 2 /g and an alumina content of 99.7 wt. % was charged into an adiabatic fixed bed reactor having an inner diameter of 22 mm, and then activated in a nitrogen flow at 550° C. for 2 h. After allowing the temperature inside the reactor to lower to reaction temperature, a feedstock consisting of methanol and ethanol (mass ratio of methanol to ethanol=4:1) was continuously fed into the reactor and allowed to react under the following conditions: temperature at reactor inlet=360° C., WHSV of the feedstock=4 h −1 , and reaction pressure=0.06 MPa (gauge). The temperature at reactor outlet was 362° C. Effluent of the reactor was analyzed, and it was found that conversion of ethanol was approximatively 100%, selectivity to ethylene was 97.7%, conversion of methanol was 81.2%, and selectivity to dimethyl ether was approximatively 100%.
Example 15
[0031] 100 g of ZSM-5 molecular sieve having a SiO 2 /Al 2 O 3 molar ratio of 40 was mixed with 60 g of a silica sol (having a silica content of 30 wt. %), and then the mixture was extruded. The extrudates were dried at 180° C. for 6 h, and then calcined at 500° C. for 4 h, to give a ZSM-5 molecular sieve catalyst.
[0032] 3 g of the prepared ZSM-5 molecular sieve catalyst was charged into a fixed bed reactor having an inner diameter of 18 mm, and then activated in a nitrogen flow at 550° C. for 2 h. After allowing the temperature inside the reactor to lower to reaction temperature, a feedstock consisting of methanol and ethanol (mass ratio of methanol to ethanol=2:1) was continuously fed into the reactor and allowed to react under the following conditions: reaction temperature=250° C., WHSV of the feedstock=3 h −1 , and reaction pressure=0.02 MPa (gauge). Effluent of the reactor was analyzed, and it was found that conversion of ethanol was 99.2%, selectivity to ethylene was 95.4%, conversion of methanol was 78.1%, and selectivity to dimethyl ether was 90.4%.
Examples 16 to 26
[0033] Experiments were carried out following the procedure as described in the Example 15 under the conditions as set forth in the Table 2 below. The results are shown in the Table 2.
[0000]
TABLE 2
Results
Weight Ratio
Reactor
WHSV of
Reaction
Conversion
Selectivity
Conversion
Selectivity
of Methanol
Temperature
Feedstock
Pressure
of Ethanol
to Ethylene
of Methanol
to Dimethyl Ether
Ex.
Catalyst
to Ethanol
° C.
h −1
MPa(gauge)
%
%
%
%
16
ZSM-5 (molar ratio of
1
280
1.0
0.2
99.8
96.2
80.1
91.3
SiO 2 /Al 2 O 3 = 40)
17
ZSM-5 (molar ratio of
1/2
300
2.2
0.05
99.7
96.7
82.4
90.9
SiO 2 /Al 2 O 3 = 60)
18
ZSM-5 (molar ratio of
6
380
10
0.8
94.1
79.1
81.4
83.6
SiO 2 /Al 2 O 3 = 180)
19
ZSM-5 (molar ratio of
1/10
260
4.5
0.5
98.7
90.6
60.4
87.7
SiO 2 /Al 2 O 3 = 120)
20
ZSM-5 (molar ratio of
1/3
320
10
0.03
96.8
87.8
68.4
89.1
SiO 2 /Al 2 O 3 = 20)
21
ZSM-5 (molar ratio of
1/2
260
3.5
0.7
100
95.6
76.0
90.2
SiO 2 /Al 2 O 3 = 52)
22
β-zeolite (molar ratio of
1/2
280
1.5
2.0
99.5
80.5
76.3
89.3
SiO 2 /Al 2 O 3 = 300)
23
Mordenite (molar ratio of
3
352
0.5
1.0
100
87.0
81.1
90.2
SiO 2 /Al 2 O 3 = 450)
24
ZSM-48 (molar ratio of
5
300
9
0
100
87.4
84.7
91.5
SiO 2 /Al 2 O 3 = 150)
25
ZSM-11 (molar ratio of
1.25
290
2.25
0.5
98.2
88.3
81.3
87.7
SiO 2 /Al 2 O 3 = 80)
26
SAPO-34
2
300
2.4
0.1
99.5
90.6
82.4
81.4
Example 27
[0034] 100 g of ZSM-5 molecular sieve having a SiO 2 /Al 2 O 3 molar ratio of 50 was mixed with 60 g of a silica sol (having a silica content of 30 wt. %), and then the mixture was extruded. The extrudates were dried at 180° C. for 6 h, and then calcined at 500° C. for 4 h, to give a ZSM-5 molecular sieve catalyst.
[0035] 3 g of the prepared ZSM-5 molecular sieve catalyst was charged into an adiabatic fixed bed reactor having an inner diameter of 18 mm, and then activated in a nitrogen flow at 550° C. for 2 h. After allowing the temperature inside the reactor to lower to reaction temperature, a feedstock consisting of methanol and ethanol (mass ratio of methanol to ethanol=2:1) was continuously fed into the reactor and allowed to react under the following conditions: temperature at reactor inlet=360° C., WHSV of the feedstock=3 h −1 , and reaction pressure=0.2 MPa (gauge). The temperature at reactor outlet was 280° C. Effluent of the reactor was analyzed, and it was found that conversion of ethanol was approximatively 100%, selectivity to ethylene was 91.3%, conversion of methanol was 83.7%, and selectivity to dimethyl ether was 90.8%.
Example 28
[0036] 100 g of ZSM-5 molecular sieve having a SiO 2 /Al 2 O 3 molar ratio of 80 was mixed with 60 g of a silica sol (having a silica content of 30 wt. %), and then the mixture was extruded. The extrudates were dried at 180° C. for 6 h, and then calcined at 500° C. for 4 h, to give a ZSM-5 molecular sieve catalyst.
[0037] 3 g of the prepared ZSM-5 molecular sieve catalyst was charged into an adiabatic fixed bed reactor having an inner diameter of 18 mm, and then activated in a nitrogen flow at 550° C. for 2h. After allowing the temperature inside the reactor to lower to reaction temperature, a feedstock consisting of methanol and ethanol (mass ratio of methanol to ethanol=4:1) was continuously fed into the reactor and allowed to react under the following conditions: temperature at reactor inlet=300° C., WHSV of the feedstock=0.8 h −1 , and reaction pressure=0.06 MPa (gauge). The temperature at reactor outlet was 300° C. Effluent of the reactor was analyzed, and it was found that conversion of ethanol was approximatively 100%, selectivity to ethylene was 92.3%, conversion of methanol was 84.2%, and selectivity to dimethyl ether was 91.3%.
[0038] The patents, patent applications, non-patent literatures and testing methods cited in the specification are incorporated herein by reference.
[0039] While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. Therefore, the invention is not limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but the invention will include all embodiments falling within the scope of the appended claims. | 4y
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BACKGROUND
[0001] A superlattice is a periodic structure of layers of at least two materials. In some examples, a layer is several nanometers thick. In some examples, a layer is a semiconductor material. In one particular example, a layer is a group III-V semiconductor material.
SUMMARY
[0002] In one aspect, an avalanche photodiode, includes an absorber, a first superlattice structure directly connected to the absorber and configured to multiply holes and a second superlattice structure directly connected to the first superlattice structure and configured to multiply electrons. The first and second superlattice structures include III-V semiconductor material. The avalanche photodiode is a dual mode device configured to operate in either a linear mode or a Geiger mode.
[0003] In another aspect, a method includes performing k·p simulations to establish bandgap and electronic band structure on a proposed configuration of the avalanche photodiode; performing Monte-Carlo simulations on the proposed configuration of the avalanche photodiode if the band-offsets are conducive for carrier transport; and determining layer thicknesses and doping levels of the avalanche photodiode. The avalanche photodiode includes an absorber; a first superlattice structure directly connected to the absorber and configured to multiply holes and a second superlattice structure directly connected to the first superlattice structure and configured to multiply electrons. The first and second superlattice structures include III-V semiconductor material. The avalanche photodiode is a dual mode device configured to operate in either a linear mode or a Geiger mode.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is a diagram of an example of a dual mode superlattice avalanche photodiode.
[0005] FIG. 2 is a graph of an example of a gain versus bias curve of the dual mode superlattice avalanche photodiode of FIG. 1 .
[0006] FIG. 3 is a graph of an example of an electron multiplication superlattice structure bandstructure.
[0007] FIG. 4 is a graph of an example of a hole multiplication superlattice structure bandstructure.
[0008] FIG. 5 is a flowchart of an example of a process to fabricate a dual mode III-V superlattice avalanche photodiode.
[0009] FIG. 6 is a computer on which any portion of the process of FIG. 5 may be implemented.
DETAILED DESCRIPTION
[0010] Described herein are techniques to fabricate an avalanche photodiode using superlattice structures that enable the avalanche photodiode to be a dual mode device (i.e., the avalanche photodiode may be operated in either a linear mode or a Geiger mode).
[0011] Referring to FIG. 1 , a circuit 100 includes an avalanche photodiode 102 . The avalanche photodiode (APD) 102 includes an absorber 104 , a first superlattice structure 108 and a second superlattice structure 112 . In some examples, the first and second superlattice structures 108 , 112 are each a type II strain layer superlattice (SLS). In one particular example, the absorber 104 is a p-type absorber graded for efficient carrier injection. The absorber 104 is configured to absorb photons at a desired wavelength (e.g., a laser wavelength used in an active imaging or ranging system).
[0012] When biased by a source 120 (e.g., a DC power source), the absorber 104 receives a photon to generate electron hole pairs (e.g., electron hole pair 114 ). The first superlattice structure 108 is configured to multiply holes and the second superlattice structure 112 is configured to multiply electrons. For example, when an electron from the electron hole pair 114 is received in the second superlattice structure 112 , the electron is multiplied (see stage I) to form two electrons in total. At second stage II, the two electrons are multiplied to become four electrons and at stage III the four electrons are multiplied to become eight electrons. When a hole is received by the first superlattice structure 108 from the second superlattice structure 112 , the hole is multiplied to become two holes in stage IV.
[0013] In one particular example, the first superlattice structure 108 and the second superlattice structure 112 are each noiseless. That is, the first superlattice structure 108 only multiplies holes (not electrons) and the second superlattice structure 112 only multiplies electrons (not holes).
[0014] The first superlattice structure 108 comprises III-V semiconductor material. In one example, the first superlattice structure 108 includes a layer of indium arsenide (InAs), a layer of indium gallium antimonide (InGaSb), a layer of aluminium antimonide (AlSb) and a layer of gallium antimonide (GaSb), which are repeated through the first superlattice structure 108 . Each layer of indium arsenide (InAs) is about 0.8 nanometers thick, each layer of indium gallium antimonide (InGaSb) is about 1.9 nanometers thick, each layer of aluminium antimonide (AlSb) is about 0.3 nanometers thick and each layer of gallium antimonide (GaSb) is about 0.1 nanometers thick. The first superlattice structure 108 is about two thousand Angstroms thick.
[0015] The second superlattice structure 108 comprises III-V semiconductor material. In one example, the second superlattice structure 112 includes a layer of indium arsenide (InAs), a layer of aluminum gallium antimonide (AlGaSb), and a layer of gallium antimonide (GaSb), which are repeated through the second superlattice structure 112 . Each layer of indium arsenide (InAs) is about 1.5 nanometers thick, each layer of aluminum gallium antimonide (AlGaSb) is about 3.8 nanometers thick and each layer of gallium antimonide (GaSb) is about 0.9 nanometers thick. The second superlattice structure 112 is about 1500 Angstroms thick.
[0016] Referring to FIG. 2 , a graph 200 depicts a curve 202 of the gain versus bias relationship of the avalanche photodiode 102 . Separate minibands within the conduction and valence bands in the avalanche photodiode allow for decreased impact ionization rates in certain energy bands as depicted in the curve 102 . Thus, the avalanche photodiode 102 can operate in either a linear mode 208 or a Geiger mode 212 . In the linear mode 208 , as the bias over the avalanche photodiode 112 is increased from zero, the avalanche photodiode 112 reaches a gain saturation region 218 , where the gain is relatively constant. With continued increased bias, the avalanche photodiode 112 reaches avalanche breakdown 206 , which starts the Geiger mode 212 . In the Geiger mode 212 there is a sharp rise in the gain with increased gain.
[0017] FIGS. 3 and 4 are examples of bandstructures for electron multiplication and hole multiplication, respectively that are configured to enable the avalanche photodiode 102 to be able to function in either the Geiger mode or the linear mode depending on bias. In FIGS. 3 and 4 , the black circles represent electrons while the white circles represent holes.
[0018] FIG. 3 is a graph of an example of an electron multiplication superlattice structure bandstructure of the second superlattice structure 112 . The second superlattice structure 112 is configured to generate a Eg<Delta resonance in the conduction band. As the reverse bias across the avalanche photodiode 102 is increased, photoelectrons, generated in the absorber 104 via photon absorption, get injected into the second superlattice structure 112 and gain energy in conduction band 1 (CC 1 ) and after gaining the threshold energy (Eth), the electrons (with finite momentum, k) start impact ionizing and generate electron-hole pairs. In the process, the electron loses energy and comes back to conduction band edge at the zone center (i.e., momentum (k)=0) (see arrows 302 a , 302 b ). The impact ionization generated electrons and holes move in opposite directions and undergo impact ionization in their respective multiplication regions (electrons impact ionize only in the electron multiplication region (e.g., second superlattice structure 112 ) while holes only multiply in the hole multiplication region (e.g., first superlattice structure 108 )). This process generates a positive feedback between the hole and electron multiplication regions. The gain in the avalanche photodiode 102 increases rapidly. If the gain is not stabilized, the avalanche photodiode 102 will exhibit runaway behavior. The electron initiated impact ionization becomes less and less efficient as the electron energy is increased beyond Eth. This is due to the strict energy and momentum conservation conditions required for impact ionization. The gain in the avalanche photodiode 102 increases but starts to saturate due to the inefficient impact ionization of electrons. This is the linear mode operation in the avalanche photodiode 102 and gain stabilization is implemented utilizing the gain saturation behavior. With proper electronic bandstructure configuration, the Eg<Delta resonance in the conduction band can be configured to occur at zone center. This configuration allows for carriers in CC 1 (at or above Eth) to scatter to the zone center in conduction band 2 (CC 2 ) as depicted by (see arrow 312 ). The scattered electrons at the zone center (k=0) in CC 2 can very efficiently impact ionize due to relaxed momentum conservation conditions. The transition matrix elements at zone center are very strong and the impact ionization process at k=0 (see arrows 308 a , 308 b is very efficient. This leads to a rapid increase in the impact ionization rate for electrons and the gain in the avalanche photodiode 102 starts to increase rapidly again, which is the Geiger mode like behavior (depicted in FIG. 2 ) in the avalanche photodiode 102 implemented using electrons in CC 2 zone center for impact ionization.
[0019] FIG. 4 is a graph of an example of a hole multiplication superlattice structure bandstructure.
[0020] Referring to FIG. 5 , a process 500 is an example of a process to fabricate a dual mode III-V superlattice avalanche photodiode (e.g., APD 102 ). The process 500 includes choosing an operating wavelength ( 502 ) and performing 14-band k·p simulations to establish a bandgap and electronic bandstructure on a particular superlattice structure (SLS) avalanche photodiode (APD) ( 508 ).
[0021] Process 500 determines whether the band-offsets are conducive for carrier transport ( 512 ). If the band-offsets are not conducive for carrier support, process 500 iterates the SLS configuration ( 514 )
[0022] If the band-offsets are conducive for carrier support, Monte-Carlo simulations are performed ( 516 ). Process 500 determines if the electron-to-hole ionization coefficient ratio is different than 1 ( 530 ). If the electron-to-hole ionization coefficient ratio is 1, process 500 iterates the SLD configuration ( 514 ). If the electron-to-hole ionization coefficient ratio is different than 1, process 500 determines whether the avalanche initiating carrier ionization rate is saturating at the desired bias ( 524 ). If the avalanche initiating carrier ionization rate is not saturating at the desired bias, process 500 iterates the SLD configuration ( 514 ).
[0023] If the avalanche initiating carrier ionization rate is saturating at the desired bias, Process 500 determines separate adsorption and multiplication (SAM) APD layer thickness and doping levels ( 528 ) and simulates gain versus bias for SLS SAM APD with dead-space multiplication theory (DSMT) code ( 534 ).
[0024] Referring to FIG. 6 , in one example, a computer 600 includes a processor 602 , a volatile memory 604 , a non-volatile memory 606 (e.g., hard disk) and the user interface (UI) 608 (e.g., a graphical user interface, a mouse, a keyboard, a display, touch screen and so forth). The non-volatile memory 606 stores computer instructions 612 , an operating system 616 and data 618 . In one example, the computer instructions 612 are executed by the processor 602 out of volatile memory 604 to perform all or part of the processes described herein (e.g., process 500 ).
[0025] The processes described herein (e.g., process 500 ) are not limited to use with the hardware and software of FIG. 6 ; they may find applicability in any computing or processing environment and with any type of machine or set of machines that is capable of running a computer program. The processes described herein may be implemented in hardware, software, or a combination of the two. The processes described herein may be implemented in computer programs executed on programmable computers/machines that each includes a processor, a non-transitory machine-readable medium or other article of manufacture that is readable by the processor (including volatile and non-volatile memory and/or storage elements), at least one input device, and one or more output devices. Program code may be applied to data entered using an input device to perform any of the processes described herein and to generate output information.
[0026] The system may be implemented, at least in part, via a computer program product, (e.g., in a non-transitory machine-readable storage medium such as, for example, a non-transitory computer-readable medium), for execution by, or to control the operation of, data processing apparatus (e.g., a programmable processor, a computer, or multiple computers)). Each such program may be implemented in a high level procedural or object-oriented programming language to communicate with a computer system. However, the programs may be implemented in assembly or machine language. The language may be a compiled or an interpreted language and it may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program may be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network. A computer program may be stored on a non-transitory machine-readable medium that is readable by a general or special purpose programmable computer for configuring and operating the computer when the non-transitory machine-readable medium is read by the computer to perform the processes described herein. For example, the processes described herein may also be implemented as a non-transitory machine-readable storage medium, configured with a computer program, where upon execution, instructions in the computer program cause the computer to operate in accordance with the processes. A non-transitory machine-readable medium may include but is not limited to a hard drive, compact disc, flash memory, non-volatile memory, volatile memory, magnetic diskette and so forth but does not include a transitory signal per se.
[0027] The processes described herein are not limited to the specific examples described. For example, the process 500 is not limited to the specific processing order of FIG. 5 . Rather, any of the processing blocks of FIG. 5 may be re-ordered, combined or removed, performed in parallel or in serial, as necessary, to achieve the results set forth above.
[0028] The processing blocks (for example, in the process 500 ) associated with implementing the system may be performed by one or more programmable processors executing one or more computer programs to perform the functions of the system. All or part of the system may be implemented as, special purpose logic circuitry (e.g., an FPGA (field-programmable gate array) and/or an ASIC (application-specific integrated circuit)). All or part of the system may be implemented using electronic hardware circuitry that include electronic devices such as, for example, at least one of a processor, a memory, a programmable logic device or a logic gate.
[0029] Elements of different embodiments described herein may be combined to form other embodiments not specifically set forth above. Various elements, which are described in the context of a single embodiment, may also be provided separately or in any suitable subcombination. Other embodiments not specifically described herein are also within the scope of the following claims. | 4y
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FIELD OF THE INVENTION
[0001] This invention relates to the field of decorative building paneling, and more particularly to decorative ceiling panels, wall panels and exterior wall sheathing panels.
BACKGROUND OF THE INVENTION
[0002] In the field of building panels, encompassing ceiling tiles or panels, interior wall panels, and exterior wall sheathing or siding, there have been many attempts to provide low cost, decorative simulated wood, marble, granite, and the like. Conventional exterior sheathing has generally been limited to relatively heavy panels in which genuine brick, stone or the like is cut into thin slabs which are either adhered directly to a wall, such as a concrete wall, or mounted on a substrate that is attached to the wall; or more lightweight materials, such as vinyl and aluminum siding, which have only provided a relatively limited variety of simulated decorative styles, typically simulated wood planks. Simulated wood, marble and granite panels for interior wall applications have generally been limited to laminates comprising a plywood, particleboard, or other composite wood backing on which is laminated a decorative facing layer. Such interior wall paneling has generally been relatively heavy, making transportation and insulation of the paneling difficult. Ceiling tiles or panels have generally included an acoustically absorbent inner core, a backing material for enhancing panel strength, and a front facing for enhancing the aesthetic appearance of the panel. Typically, the inner core may comprise fiberglass batts formed from resin impregnated fiberglass, wet-laid mineral, slag mineral, cellulose fibers, or combinations thereof, and may include a variety of inorganic fillers such as perlite, clays and/or gypsum. These panels are often relatively heavy, and are sometimes subject to deformation.
SUMMARY OF THE INVENTION
[0003] The invention provides a lightweight panel structure that is adaptable for use as interior ceiling panels, interior wall panels, and exterior sheathing or siding. The panel structures of this invention also exhibit excellent rigidity, and can be made to exhibit a combination of good sound attenuation properties, excellent aesthetic appearance, uniformity of aesthetic quality, outstanding weatherability, and/or a low manufacturing cost.
[0004] The decorative composites of this invention, which in certain embodiments may be suitable for use as ceiling panels, interior wall panels, and exterior sheathing, include a non-woven fibrous batt comprised of thermoplastic fibers; a scrim layer bonded to each of two opposite sides of the non-woven fibrous batt; and a decorative film layer having a surface indicia on an exterior side and an opposite interior side bonded to one of the scrim layers.
[0005] In accordance with another aspect of the invention, the decorative composite panel of this invention are made by providing a core layer configured from non-woven fibers, in which at least some of the fibers comprise a heat-activated resin; providing first and second scrim layers; positioning the first and second scrim layers overlying opposite faces of the core layer in a stacked relationship to define a composite assembly; heating the composite assembly to a temperature which causes the heat activatable resin in the core layer to bond with the first and second scrim layers; providing a decorative film layer having indicia applied to the exterior face thereof; and adhering an interior face of the decorative film to an exterior face of one of the first and second scrim layers to define the decorative panel.
[0006] These and other features, advantages and objects of the present invention will be further understood and appreciated by those skilled in the art by reference to the following specification, claims and appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a bottom view of a ceiling panel in accordance with the inventions.
[0008] FIG. 2 is a cross-sectional view of an edge of the ceiling panel shown in FIG. 1 .
[0009] FIG. 3 is a perspective view of a corner of the ceiling panel shown in FIGS. 1 and 2 .
[0010] FIG. 4 is a bottom plan view of a corner of the ceiling panel shown in FIGS. 1-3 .
[0011] FIG. 5 is an enlarged cross-sectional view of an edge of a ceiling panel according to the invention supported on a ceiling grid railing.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0012] A decorative composite panel 20 ( FIG. 1 ) includes a decorative film layer 21 having surface indicia on its exterior side. In the illustrated embodiment, the surface indicia is a simulated wood grain. However, simulated marble, granite and other surface indicia are contemplated. The decorative film 21 is bonded to a substrate comprising a non-woven fibrous batt 22 comprised of thermoplastic fibers. Bonded to each of the two opposite sides of non-woven fibrous batt 22 are scrim layers 24 and 25 .
[0013] The decorative film layer 21 typically consists of a vinyl polymer or copolymer such as polyvinylchloride, polyester, polyurethane, polyolefin or other polymeric film on which a desired decorative indicia is printed. If desired, other layers of material may be applied over the printed film layer for various reasons that may include scratch resistance, abrasion resistance, graffiti resistance, added depth to the top layer appearance, a carrier for anti-microbial agents, weather resistance, stain resistance and sound deadening. The printed indicia may simulate various building materials, including, but not limited to, wood grain patterns of all species of wood, stone, rock, leather, any type of painted surface, gold leaf, plated surfaces, graphite, dyed surfaces, plated silver, powder coated surfaces, and minerals. Any type of material that can be simulated on a printed material may be used. The printed material is typically produced in various ways to add significant realism to the appearance of the laminate material to promote flexibility of the surface without degradation of the appearance. Manufacturing techniques used to produce the printed material include folding, bellowing, and pre-saturating to allow the material to be formed and shaped without separation of the printing that might result in a degradation appearance of the material. Typically, the decorative film layer is from about 6 mils to about 40 mils thick, and more typically from about 6 mils to about 20 mils thick.
[0014] One way to add significant realism to the appearance of the surface indicia on the decorative film layer is to photograph a pattern from more than one position. These images are then recorded on a computer and used to etch a series of chrome cylinders which emboss the grain or texture into the printed material. After embossing, a coloring agent may optionally be added to the grain, adding realism and depth. This printing process is useful for any type of decorative pattern, including the multitude of wood grain patterns of different species of wood. This printing process, and any other known to one of ordinary skill in the art, can be performed on any suitable decorative layer, including printed polyvinylchloride, polyester, polyurethane, etc.
[0015] Non-woven batt 22 may be comprised of generally any combination of synthetic, natural and/or mineral fibers, provided that the non-woven fibrous layer 22 includes a sufficient quantity of heat activatable thermoplastic fibrous that will provide desirable shape retention properties to the non-woven layer 22 and resulting composite panel 20 upon heating to a temperature at or above the activation temperature of the heat activatable fibers and subsequent cooling in a thermoforming shaping process. Suitable heat activatable thermoplastic fibers include various fibers that can be softened and/or partially melted upon application of heat during a thermoforming process to form a multiplicity of bonds at fiber-fiber intersections to impart shape retention properties. Examples of suitable heat activatable thermoplastic fibers include those comprised of homopolymers and copolymers of polyester, nylon, polyethylene, polypropylene and blends of fibers formed from these polymers and copolymers. Particularly suitable are composite or bi-component fibers having a relatively low melting binder component and a higher melting strength component. Bi-component fibers of this type are advantageous since the strength component imparts and maintains adequate strength to the fiber while the bonding characteristics are imparted by the low temperature component. A variety of bi-component fibers of this type are commercially available from various sources. One suitable fiber for use in the present invention is a sheath-core bi-component structure wherein the core is formed of a relatively high melting polyethylene terephthalate (PET) polymer and the sheath comprises a PET copolymer having a lower melting temperature which exhibits thermoplastic adhesive and thermoformability properties when heated to a temperature of about 185° F. to 210° F. The amount of heat activatable fiber in non-woven fibrous batt 22 is selected to provide the desired shape retention properties for a particular panel structure used in a particular application. Typically, non-woven fibrous batt 22 comprises at least about 10 % heat activatable thermoplastic fibers by weight. There is no upper limit to the amount of heat activatable fibers that may be utilized in the non-woven fibrous batt. However, because heat activatable fibers are typically more expensive than other synthetic, natural and/or mineral fibers, it is typically desirable to use only the amount of heat activatable thermoplastic fiber that is needed to achieve the desired shape retention properties and rigidity required for the finished decorative composite panel. Typically, the amount of heat activatable fiber in non-woven fibrous batt 22 is from about 10% to about 50% by weight of the fibrous batt 22 .
[0016] In order to reduce cost, non-heat activatable synthetic fibers, natural fibers, and/or mineral fibers may be utilized in non-woven fibrous batt 22 in amounts typically ranging from about 50% to about 95% of the weight of fibrous batt 22 . As with the heat-activatable fibers, the non-heat activatable synthetic fibers may be comprised of homopolymers and copolymers or polyester, nylon, polyethylene, propylene, etc., and blends of fibers formed from these polymers and copolymers. Natural fibers that may be employed include kenaf, grasses, rice hulls, bagasse, cotton, jute, hemp, flax, bamboo, sisal, abaca and wood fibers. Examples of mineral fibers include glass, ceramic and metal fibers. However, mineral fibers are generally not preferred, especially in relatively high qualities, as they may tend to undesirably add weight to the decorative composite panels.
[0017] The scrim layers 24 , 25 are lightweight fabrics that are not lofted or have a very low loft. In general, unlike the non-woven fibrous batt 22 , which is a lofted fabric having relatively randomly oriented fibers, scrim layers 24 , 25 have essentially no vertically oriented fibers (i.e., fibers that extend perpendicular to the plane of the scrim fabric sheet). Instead, substantially all of the fibers in scrim layers 24 , 25 are oriented within the plane of the fabric sheet. Scrim layers 24 , 25 may be comprised of generally any combination of synthetic, natural and mineral fibers, and may be either woven or non-woven. Scrim layers 24 , 25 may also be distinguished from non-woven fibrous batt 22 by their thicknesses and/or basis weights. More specifically, the scrim layers 24 , 25 typically have a thickness in the range of from 0.5 to 1.5 millimeters and a basis weight (weight per unit area of fabric) in the range of 20 to 40 grams per square foot, whereas the non-woven fibrous batt or core layer 22 typically has a basis weight in the range of 60 to 120 grams per square foot, and typically has a thickness in the range of 8 to 12 millimeters prior to thermoforming, and a thickness in the range of from 4 to 6 millimeters in the finished decorative composite panel after thermoforming.
[0018] During the thermoforming process, scrim layers 24 , 25 are bonded to core layer 22 . This bonding can be achieved by fiber-fiber bonding of fibers at the interfaces between the core layer 22 and scrim layers 24 , 25 . In some cases, fusion of heat-activated fibers of core layer 22 with fibers of scrim layers 24 , 25 at the interfaces of the layers will provide sufficient adhesion. In other cases, it may be desirable to utilize an adhesive for bonding scrim layers 24 , 25 to core layer 22 . Adhesives for bonding scrim layers 24 , 25 to core layer 22 may comprise a thin heat-activatable thermoplastic film that is disposed between each of the scrim layers 24 , 25 and the opposite sides of core layer 22 , and which melts and subsequently fuses the layers together during a thermoforming process. A preferred adhesive is a low temperature reactive polyurethane resin (PUR). Alternatively, various thermosetting resin compositions may be sprayed, brushed, roll-coated or otherwise deposited between scrim layers 24 and the opposite sides of core layer 22 . Examples include polyamides, polyepoxides, reactive polyurethane resins, etc., which desirably cure upon application of heat during a thermoforming process in which the heat-activatable fibers in core layer 22 are simultaneously or contemporaneously activated and subsequently fused to provide shape retention of the composite.
[0019] The resulting three-layer composite is a relatively thin (about 5 to 10 millimeters), lightweight (about 100 to 200 grams per square foot) composite that exhibits exceptional rigidity. The scrim layers 24 , 25 bonded on opposite sides of core layer 22 very dramatically increase the bending strength of the composite without adding significant thickness or weight to the composite.
[0020] While it is conceivable that decorative film layer 21 could be bonded to one of the scrim layers 24 , 25 during the thermoforming process, it is generally more desirable to adhesively bond film layer 21 to a pre-formed composite comprising scrim layers 24 , 25 bonded to core layer 22 . More specifically, it has been determined that it is desirable to pre-form a composite assembly comprising scrim layers 24 , 25 bonded to core layer 22 using a relatively higher temperature thermoforming process (e.g., 185-210° F.) with heat activatable fibers that are activated at these relatively higher temperatures, and to bond the decorative film layer 21 to the pre-formed composite using an adhesive layer 23 comprising a heat activatable resin that melts, becomes tacky or cures at a relatively low temperature (e.g., 150-180° F.).
[0021] This two-step process provides an extremely smooth decorative surface, without impressions from the underlying fibers that may occur when all of the layers of the composite are bonded and formed together in a single operation.
[0022] As shown in FIGS. 3 and 4 , the decorative composite panels of this invention can be shaped to have contours (i.e., non-planar surfaces), such as beveled edges 26 , and variable thickness and density. For examples, in the illustrated embodiment, the beveled edges are more compressed, and therefore are denser and more rigid to provide added strength to prevent sag in ceiling applications.
[0023] For indoor applications such as for ceiling tiles and/or wall panels, decorative film layer 21 may be provided with microperforations to impart improved sound absorption characteristics. Preferably, the micrperforations are made prior to attachment of film layer 21 to the composite structure. Techniques for making microperforations in a polymer film are well known. Preferably, the microperforations are substantially invisible, and do not detract from the aesthetic effect of the decorative printed indicia.
[0024] The decorative panels of this invention may be made by providing a core layer configured from non-woven fibers, preferably in which at least some of the fibers comprise a heat activatable resin, providing first and second scrim layers, positioning the scrim layers overlying opposite faces of the core layer in a stacked relationship to define a composite assembly, optionally disposing an adhesive between each of the scrim layers and the core layer, heating the composite assembly to a temperature which causes the heat activatable resin in the core layer to bond with adjacent fibers in the core layer and/or which causes the core layer to bond with the first and second scrim layers, providing a decorative film layer having indicia applied to the exterior face thereof, and adhering an interior face of the decorative film to an exterior face of one of the first and second scrim layers to define a decorative panel.
[0025] As a particular example, a cover panel for building construction and the like can be prepared using the method generally outlined above, wherein the core layer is configured from non-woven synthetic fibers having a heat activated resin, a thickness in the range of 4-12 millimeters, and a surface density (basis weight) in the range of 60-120 grams per square foot; and scrims layers configured from woven or non-woven synthetic fibers, having or not having a heat-activated resin, each of the scrim layers having a thickness in the range of 0.5-1.5 millimeters and a surface density (basis weight) in the range of 20-40 grams per square foot. In certain embodiments, such as for ceiling tiles, the composite assembly may be selectively compressed while being heated so that the first and second scrim layers adhere to the opposite faces of the core layer and define a lightweight, rigid, substrate having a lofted central portion with a thickness in the range of 8-12 millimeters and an inelastically compressed marginal portion with a thickness in the range of 4-6 millimeters to define a rigid support edge.
[0026] In accordance with another specific embodiment, ceiling tiles in accordance with the invention may be prepared generally as outlined above, using a core layer configured from non-woven PET synthetic fibers with a heat-activated resin, and wherein the core layer has thickness in the range of 4-12 millimeters and a surface density (basis weight) in the range of 60-120 grams per square foot, and wherein the first and second scrim layers are configured from non-woven PET synthetic fibers with a heat-activated resin, and wherein each of the scrim layers has a thickness in the range of 0.5-1.5 millimeters and a surface density (basis weight) in range of 20-40 grams per square foot. As with the previously described example, the scrim layers are overlying opposite faces of the core layer in a vertically stacked relationship to define a composite assembly, heated to a temperature which causes the heat activatable resin in the core layer to become tacky and/or melt and subsequently bond with adjacent fibers in the core layer and, optionally in the scrim layers, and selectively compressed while heated to adhere the first and second scrim layers to the opposite faces of the core layer and define a lightweight, rigid, tile substrate having a lofted central portion with a thickness in the range of 8-12 millimeters to attenuate sound transmission, and an inelastically compressed marginal portion with a thickness in the range of 4-6 millimeters to define a rigid hanger edge from which the tile is supported. The resulting hanger edge 30 (shown in FIG. 5 ) allows ceiling tile 20 to be supported on an upper surface of a support flange 32 of a ceiling grid support rail 34 . In the illustrated embodiment, support edge 30 has a bottom downwardly facing surface 36 bearing upon an upwardly facing surface 38 of flange 32 , with downwardly facing surface 36 being offset from and substantially parallel with exterior face 40 of the central lofted portion of panel 20 . Ceiling panel 20 shown in FIG. 5 also includes an angled leg 42 that extends from the central lofted portion 28 of panel 20 to the rigid support edge 30 of panel 20 . Angled leg 42 transitions between the higher density, lower loft, more rigid hanger edge portion 30 to the higher loft, lower density, sound attenuating central portion 28 , and therefore has a variable thickness, density, and loft. Thus, in accordance with another aspect of the invention, there is provided a suspended ceiling for a building comprising a hanger grid and ceiling panels as illustrated in FIG. 5 supported on the grid.
[0027] The above description is considered that of the preferred embodiments only. Modifications of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiments shown in the drawings and described above are merely for illustrative purposes and not intended to limit the scope of the invention, which is defined by the following claims as interpreted according to the principles of patent law, including the doctrine of equivalents. | 4y
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