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This application is continuation-in-part of Ser. No. 039,788, filed Apr. 16, 1987, which was a continuation of Ser. No. 893,535, filed Aug. 5, 1986, which was a continuation of Ser. No. 641,739, filed Aug. 17, 1984, all now abandoned.
FIELD OF THE INVENTION
The invention relates to alkaline primary batteries and, in particular, to an improved seal which reduces the leakage of electrolyte and extends the life thereof.
BACKGROUND OF THE INVENTION
Alkaline primary batteries and, in particular, alkaline manganese dioxide/zinc dry cells (MnO 2 /Zn), have been a successful commercial development. When manufactured in a cylindrical configuration, the battery seal is typically made by compressing a plastic member (gasket) within a metal can by crimping the open end of the can as disclosed by Ralston and Ko in U.S. Pat. No. 3,663,301. More particularly, in the typical commercial alkaline primary batteries, the battery seal comprises the nickel plated steel can, i.e., the positive current collector, a plastic seal member, typically of nylon or polypropylene, and a sealant between the metal can and the plastic seal member. However, cells constructed according to the disclosure of Ralston and Ko are susceptible to electrolyte leakage. Such leakage usually occurs at the interface of the gasket and the metal can and is due to the propensity of alkaline electrolytes to wet metal surfaces.
To reduce the leakage of electrolyte from alkaline cells, sealant materials are used between the gasket and the metal surface. Typically asphaltic compounds such as bitumen are used. However, such seals are only marginally satisfactory, and then only when the steel cans are plated with nickel. When the steel can is unplated, such seals are very poor. The poorer seals noticed with unplated steel cans are probably due to differences in the bonding strength of bitumen to steel and bitumen to nickel-plated steel.
Others, attempting to improve upon the seals of alkaline batteries have used sealants consisting of fatty polyamides, e.g., U.S. Pat. No. 3,922,178 to Winger, cured epoxy-polyamine resins, e.g., U.S. Pat. No. 3,713,896 to Feldhake, or both bitumen and fatty polyamide resins, e.g., Japanese patent Application No. J5-4007-536. However, as explained in U.S. Pat. No. 4,282,293 to van Lier, all of these solutions have the same drawback--leakage still occurs since these materials do not always completely seal the interface of the metal surface and the gasket. It is hypothesized that leakage results from the inability of the sealant, or sealants, to adequately bond to the metal surface. Moreover, sealants such as bitumen and fatty polyamides are soft, somewhat tacky materials at and above room temperature and so are subject to damage and contamination during the assembly of electrochemical cells. Even cured epoxy-polyamine resins, though non-tacky, are relatively soft and can cause problems during cell assembly.
The battery seal set forth in U.S. Pat. No. 4,282,293 solves many of the processing problems as described above. However, as with cells incorporating bitumen and polyamides in the seal area, extreme care must be taken to confine the organosilane resin of the van Lier patent to the immediate area of the seal, otherwise the electrical operation of the cell will be adversely affected by the introduction of a non-conductive layer between the electrode and current collector.
It is a primary object of the present invention to provide for a stronger seal for alkaline cylindrical cells.
Another object of the present invention is to provide for strong seals in alkaline cylindrical cells wherein the metal cans, i.e., the positive current collectors, are unplated steel.
Still another object of the present invention is to provide for a strong seal in an alkaline cylindrical cell which is easy to make and is compatible with the alkaline cylindrical cell assembly process.
The foregoing and additional objects will become more fully apparent with the following description.
SUMMARY OF THE INVENTION
An alkaline battery seal comprising a sealant, such as bitumen and/or fatty polyamides, compressed between a plastic seal disk and a steel current collector coated on its inner surface with a hard, non-tacky, conductive, filled plastic film. Such a battery seal allows for simplified construction of alkaline batteries and substantially reduces electrolyte leakage from such cells.
DETAILED DESCRIPTION OF THE INVENTION
The objects of the present invention are achieved by applying a conductive filled polymeric resin to the surface of the metal container (positive current collector) in the area of the battery seal. The resulting thin conductive plastic film, which may extend between container and the cell cathode, forms a bond between the metal container and the sealant conventionally used in battery seals. By practicing the present invention, the positive current collector can be unplated steel, which reduces the cost of manufacturing alkaline cylindrical cells. Since the coating of the present invention is conductive, the problem of previous battery seal methods which require the sealants and any seal area coatings to be confined to the seal area is avoided. And since the coating is non-tacky, alkaline batteries using the present invention are easier to manufacture.
In accordance with the present invention, the interior surface of the metal can of an alkaline dry cell is coated with a conductive polymeric primer. This primer, which may be applied by various techniques, including painting, spraying or dipping, contains an alkaline resistant organic binder dissolved in a compatible solvent. Spraying is the preferred method of applying the organic primer.
After being applied to the metal can, the primer is dried at elevated temperatures, which permits the evaporation of the solvent and allows for the adhesion of a thin, non-tacky conductive resin coating to the metal container. The resulting coating is typically 0.0006 inches to 0.0008 inches in thickness, but may range from 0.0001 inches to 0.002 inches in thickness.
In the present invention, the binder is a film forming polymer which is compatible with alkaline battery components. Film forming binders which dissolve, hydrolyze or oxidize in the presence of the electrolyte cannot be used in practicing the present invention. The present invention can be successfully practiced with a wide range of polymeric binders including ABS (acrylonitrile butadiene styrene), PVC (polyvinyl chloride), epoxies, fluorcarbons, nylons, polypropylene, polybutylene, polystyrenes and neoprenes. The present invention may also be practiced with binders which are rubbers and/or elastomers, such as, isobutylene, isoprene, chloroprene, polysulfide, ethylene propylene, chlorinated and chlorosulfonated polyethylene, fluorosilicone and propylene oxide. However, materials which are soluble in KOH, the usual electrolyte found in alkaline battery systems, such as CMC, should not be used in practicing the present invention.
To practice the present invention, the solvent portion of the resin must be compatible with and wet the surface of the metal container. The solvent must also be compatible with the binder. The present invention can be successfully practiced with solvents such as ethyl acetate, butanol, methyl ethyl ketone, methyl isobutyl ketone and paraffinic hydrocarbon liquids.
The polymeric resins of the present invention contain conductive filler materials such as carbon. When carbon is added as the conductive filler, the weight percent of carbon in the film after the evaporation of the solvent must be less than 40. Increasing the amount of carbon, which reduces the amount of binder in the plastic film, decreases the mechanical integrity of the plastic film and increases the probability that the conductive film will not remain adhered to the surface of the metal container.
The presence of carbon in the film increases the hardness of the film while further decreasing it tackiness, thereby causing the film to be more easily handled during the alkaline battery manufacturing processes. For example, since the conductive film of the present invention has a tack-free surface, it exhibits almost no resistance to the insertion of the cathode, thereby simplifying the assembly of alkaline batteries. Moreover, since the coating of the present invention improves the adhesion of the sealant to the metal container surface, the application of the conventional sealant, such as bitumen, is less critical with respect to the wetting of the metal surface and so it may be applied using techniques compatible with the presence of one or several of the anode, separator and cathode within the metal container. Thus the bitumen may be applied as a thin bead around the inside of the container only partly covering the seal area to avoid contamination of the other battery parts. Insertion of the plastic sealing disk will then smear the bitumen over the seal area an adhere the sealing disk to the coating. This method avoids the problem of having to coat the sealing disk and process it with a tacky bitumen coated surface.
In order to provide the advantages disclosed herein the plastic film must be impervious to the alkaline electrolyte. Therefore, the plastic film must be continuous in the area of the sealant and metal container interface, but it need not be pore-free. In otherwords, while the plastic film may contain pores which allow for alkaline electrolyte to contact the steel container, the pores are sufficiently discontinuous such that there are no channels formed to allow electrolyte to pass from the interior of the battery to the open end of the container.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a drawing of an alkaline cylindrical battery incorporating this invention.
FIG. 2 is an enlarged drawing of the seal area of the alkaline cylindrical battery of FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENT
FIG. 1 is a drawing of an alkaline cylindrical battery constructed according to the present invention. The positive current collector, a drawn steel container (2), open on one end and about 0.010 inches thick, has a conductive coating (14) applied to its interior surfaces. Two cathode annular rings (5) are placed in contact with the positive current collector. A bead (10) is formed into the container near the open end to support the sealing disk. A separator (4) and an anode (3) are placed inside of the cathode rings. A sealing disk (6) to which sealant (15) has been applied and containing a negative current collector (1) is placed into the open end of the container and in contact with the bead. The open end of the container is crimped over the sealing disk thus compressing it between the crimp of the container on to which the coating (14) has been applied and the bead to seal the cell. An insulation washer (7) with a central aperture is placed over the crimped end of the cell such that the end of the negative current collector (1) protrudes through the aperture. A contact spring (8) is affixed to the end of the negative current collector (1). Terminal caps (9) and (13) are placed into contact with the contact spring (8) and the positive current collector (2), respectively, and an insulating tube (12) and steel shell (11) are placed around the cell and crimped on their ends to hold the terminal caps in place.
Examples of the utility of the present invention will now be explained.
EXAMPLE 1
Three sets of adhesion test samples were prepared. The first set used a substrate of nickel-plated steel, the second set used a substrate of unplated steel, and the third set used a substrate of unplated steel coated with P-70 primer (a conductive plastic of PVC and carbon black in methyl ethyl ketone based solvent manufactured by Pervel Industries). 0n to each substrate, a metal washer with a 0.5" diameter opening was placed and a molten bitumen, Pioneer 135 (Witco Chemical Corp.), was poured inside the washer. The 5/8" diameter head of a bolt was then placed on the molten bitumen. These samples were then arranged in a tensile testing machine so that the force required to separate the bitumen from the substrate could be measured. The results in Table I show that the bond strength was improved by use of the P-70 primer. In Table I, the failure mode designation indicates the location of the separation. Cohesive failure is desired as this indicates that the weakest point of the bond is within the bitumen sealant itself, not at the metal/substrate surface, while adhesive failure, which indicates the weakest point of the bond is at the metal/substrate surface, is undesirable.
TABLE I______________________________________0° F. Adhesion Test Using Pioneer 135 BitumenSubstrate Adhesion, lb/.5" dia. Failure Mode______________________________________Nickel plated steel 3.9 CohesiveUnplated steel 2.4 AdhesiveP-70 primed, unplated steel 4.6 Cohesive______________________________________
EXAMPLE 2
Two sets of alkaline manganese D-size cells were constructed using unplated steel cans as the positive current collector. The cans for the first set of batteries were not treated, while the metal containers used for the second set of batteries had their inner surfaces sprayed with P-70 primer. Batteries were then manufactured identically from the two sets of cans according to FIG. 1. The cells were leakage tested by subjecting them to a thermal shock cycle consisting of 8 hours at 130° F. followed by 16 hours at 0° F., for a total of three cycles. The outer wrap of each cell, consisting of the two terminal caps, the paper insulating tube, the insulating washer, the contact spring and the steel shell were then removed, and the number of cells with leakage between the sealing disks and the metal cans were counted. The data shown in Table II indicates that the present invention greatly improves the seal in alkaline cylindrical cells.
TABLE II______________________________________Three 0° F.-130° F. Thermal ShocksCan Primer % Leakage______________________________________Unplated steel None 100%Unplated steel P-70 0%______________________________________
EXAMPLE 3
A coating tack test, a modification of ASTM Standard D 2979, was conducted to compare the tackiness of P-70, a preferred coating material, and Macromelt 6238, a fatty polyamide having a maximum amine value of 2, such as described in Japanese Patent Application No. J5-4007-536. A solution of coating was deposited and dried on a face of two smooth metal blocks. The coated faces were then pressed together under a five pound weight for a set period of time. The coated faces were then placed in a force gauge and the force required to separate them was measured, thereby determining the tack strength. As shown in Table III, a coating of the present invention is virtually tack-free, while coatings comprised of fatty polyamides having a very low amine value exhibit a substantial degree of tack.
TABLE III______________________________________Coating Tack TestCoating Test Contact Contact TackMaterial Area Time Force Strength______________________________________P70 0.25 in.sup.2 1/2 hr. 5 lbs. 0 lbs. 0.25 in.sup.2 24 hr. 5 lbs. 0 lbs.MACROMELT 0.25 in.sup.2 1/2 hr. 5 lbs. 1.4 lbs.6238 0.25 in.sup.2 24 hr. 5 lbs. 2.5 lbs.______________________________________
From the results in the foregoing examples and the referenced drawing, it is evident that the alkaline primary cells of this invention are superior to conventional alkaline primary batteries. While the foregoing examples used the alkaline Mn 2 O/Zn electrochemical system in a commercial cylindrical configuration, the present invention includes other alkaline electrochemical systems which use an electrolyte which is not corrosive to the positive current collector. | 4y
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This is a continuation of application Ser. No. 07/703,640, filed May 21, 1991, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a treatment of ocular hypertension with a synergistic combination comprising (a) a 3,14-dihydro-15-ketoprostaglandin compound and (b) a cholinergic agent.
The compounds used as the component (a) in the present invention are prostaglandin analogues which can be obtained synthetically.
2. Information of Prior Art
Prostaglandins (hereinafter, prostaglandins are referred to as PGs) are members of a class of organic carboxylic acid that are contained in human and most other mammalian tissues or organs and that exhibit a wide range of physiological activities. Naturally occurring PGs possess as a common structural feature the prostanoic acid skeleton: ##STR1## Some synthetic analogues have somewhat modified skeletons. The primary PGs are classified based on the structural feature of the five-membered cycle moiety into PGAs, PGBs, PGCs, PGDs, PGEs, PGFs, PGGs, PGHs, PGIs and PGJs, and also on the presence or absence of unsaturation and oxidation in the chain moiety as:
Subscript 1 - - - 13,14-unsaturated-15-OH
Subscript 2 - - - 5,6- and 13,14-diunsaturated-15-OH
Subscript 3 - - - 5,6- 13,14- and 17,18-triunsaturated-15-OH
Further, PGFs are sub-classified according to the configuration of hydroxy group at position 9 into α-(hydroxy group being in the alpha configuration) and β-(hydroxy group being in the beta configuration).
It has been known that Pilocarpine inhibit the ocular pressure lowering activity of PGF 2 α (Ganka MOOK No. 40, page 227, FIG. 10).
On the other hand, the fact that the above component (a) have ocular hypotensive activity has been known by Japanese Patent Publication No. A-108/1990. The publication discloses, on page 9, column 3, lines 3-2 from bottom, that 13,14-dihydro-15-keto-PGs, including the above component, can be co-used with Pilocarpine or Carbachol, both being examples of the component (b) in the present invention (and these are known as agents for treating glaucoma). The disclosure, however, unfocusingly refers to the possibility of co-use of 13,14-dihydro-15-keto-PGs and Pilocarpine or Carbachol. In contrast, when PGF 2 α (Ganka MOOK) is analogized with the component (a), it is expected that the cholinergic agents such as Pilocarpine inhibit the ocular pressure lowering effect of the component (a) if they are co-administered.
After an extensive study on the possibility that the effect of the component (a) in the present invention is improved by combining it with a variety of compounds, the present inventor has surprisingly discovered that the effect of the component (a) is significantly improved and side-effect is decreased by co-administration with cholinergic agents such as Pilocarpine. Said discovery leads to the present invention.
SUMMARY OF THE INVENTION
In a first aspect, the present invention provides a method for treatment of ocular hypertension which comprises ocularly administering, to a subject in need of such treatment, an oculo-hypotensively synergistic combination of
(a) a 13,14-dihydro-15-ketoprostaglandin compound, and
(b) a cholinergic agent
in an amount effective in treatment of ocular hypertension.
In a second aspect, the present invention provides a use of an oculo-hypotensively synergistic combination of
(a) a 13,14-dihydro-15-ketoprostaglandin compound, and
(b) a cholinergic agent
for the manufacture of a medicament useful in treatment of ocular hypertension.
In a third aspect, the present invention provides a pharmaceutical composition for treatment of ocular hypertension which comprising an oculo-hypotensively synergistic combination of
(a) a 13,14-dihydro-15-ketoprostaglandin compound, and
(b) a cholinergic agent
in association with a pharmaceutically acceptable carrier, diluent or excipient.
DETAILED DESCRIPTION OF THE INVENTION
The "13,14-dihydro-15-ketoprostaglandin compounds", used as the component (a) in the present invention and referred to as the component (a), include any prostaglandin derivatives which have a single bond in place of the double bond between positions 13 and 14 and an oxo group in place of the hydroxy group at position 15 of the prostanoic acid nucleus.
Nomenclature
Nomenclature of the component (a) herein uses the numbering system of prostanoic acid represented in formula (A) shown above.
While formula (A) shows a basic skeleton having twenty carbon atoms, the 13,14-dihydro-15-keto-PG compounds used in the present invention are not limited to those having the same number of carbon atoms. The carbon atoms in Formula (A) are numbered 2 to 7 on the α-chain starting from the α-carbon atom adjacent to the carboxylic carbon atom which is numbered 1 and towards the five-membered ring, 8 to 12 on the said ring starting from the carbon atom on which the α-chain is attached, and 13 to 20 on the ω-chain starting from the carbon atom adjacent to the ring. When the number of carbon atoms is decreased in the α-chain, the number is deleted in order starting from position 2 and when the number of carbon atoms is increased in the α-chain, compounds are named as substituted derivatives having respective substituents at position 1 in place of carboxy group (C-1). Similarly, when the number of carbon atoms is decreased in the ω-chain, the number is deleted in order starting from position 20 and when the number of carbon atoms is increased in the ω-chain, compounds are named as substituted derivatives having respective substituents at position 20. Stereochemistry of the compounds is the same as that of above formula (A) unless otherwise specified. Thus, 13,14-dihydro-15-keto-PG compounds having 10 carbon atoms in the ω-chain is nominated as 13,14-dihydro-15-keto-20-ethyl-PGs.
The above formula expresses a specific configuration which is the most typical one, and in this specification compounds having such a configuration are expressed without any specific reference to it.
In general, PGDs, PGEs and PGFs have a hydroxy group on the carbon atom at position 9 and/or 11 but in the present specification the term "13,14-dihydro-15-keto-PG compounds" includes PGs having a group other than a hydroxyl group at position 9 and/or 11. Such PGs are referred to as 9-dehydroxy-9-substituted-PG compounds or 11-dehydroxy-11-substituted-PG compounds.
As stated above, nomenclature of the component (a) is based upon the prostanoic acid. These compounds, however, can also be named according to the IUPAC naming system. For example, 13,14-dihydro-15-keto-16R,S-fluoro-PGE 2 is (Z)-7-{(1R,2R,3R)-3-hydroxy-2-[(4R,S)-fluoro-3-oxo-1-octyl]-5-oxocyclopentyl}-hept-5-enoic acid. 13,14-dihydro-15-keto-20-ethyl-PGE 2 is (Z)-7-{(1R,2R,3R)-3-hydroxy-2-[3-oxo-1-decyl]-5-oxocyclopentyl}-hept-5-enoic acid. 13,14-dihydro-15-keto-20-ethyl-PGF 2 α isopropyl ester is isopropyl (Z)-7-[(1R,2R,3R,5S)-3,5-dihydroxy-2-{3-oxo-1-decyl)-cyclopentyl]-hept-5-enoate. 13,14-dihydro-15-keto-20-methyl-PGF 2 α methyl ester is methyl (Z)-7-[(1R,2R,3R 5S)-3,5-dihydroxy-2-{3-oxo-1-nonyl}-cyclopentyl]-hept-5-enonate.
Preferred Compounds
The component (a) used in the present invention may be any derivatives of PG insofar as they are saturated between positions 13 and 14 and have an oxo group at position 15 in place of the hydroxy group, and may have no double bond (PG subscript 1 compounds), a double bond between positions 5 and 6 (PG subscript 2 compounds), or two double bonds between positions 5 and 6 as well as positions 17 and 18 (PG subscript 3 compounds).
Typical examples of the compounds used in the present invention are 13,14-dihydro-15-keto-PGA 1 , 13,14-dihydro-15-keto-PGA 2 , 13,14-dihydro-15-keto-PGA 3 , 13,14-dihydro-15-keto-PGB 1 , 13,14-dihydro-15-keto-PGB 2 , 13,14-dihydro-15-keto-PGB 3 , 13,14-dihydro-15-keto-PGC 1 , 13,14-dihydro-15-keto-PGC 2 , 13,14-dihydro-15-keto-PGC 3 , 13,14-dihydro-15-keto-PGD 1 , 13,14-dihydro-15-keto-PGD 2 , 13,14-dihydro-15-keto-PGD 3 , 13,14-dihydro-15-keto-PGE 1 , 13,14-dihydro-15-keto-PGE 2 , 13,14-dihydro-15-keto-PGE 3 , 13,14-dihydro-15-keto-PGF 1 , 13,14-dihydro-15-keto-PGF 2 , 13,14-dihydro-15-keto-PGF 3 , wherein PG is as defined above as well as their substitution products or derivatives.
Examples of substitution products or derivatives include pharmaceutically or physiologically acceptable salts and esters at the carboxy group at the alpha chain, unsaturated derivatives having a double bond or a triple bond between positions 2 and 3 or positions 5 and 6, respectively, substituted derivatives having substituent(s) on carbon atom(s) at position 3, 5, 6, 16, 17, 19 and/or 20 and compounds having lower alkyl or a hydroxy (lower) alkyl group at position 9 and/or 11 in place of the hydroxy group, of the above PGs.
Examples of substituents present in preferred compounds are as follows: Substituents on the carbon atom at position 3, 17 and/or 19 include lower alkyl, for example, C 1-4 alkyl, especially methyl and ethyl. Substituents on the carbon atom at position 16 include lower alkyl e.g. methyl, ethyl etc., hydroxy and halogen atom e.g. chlorine, fluorine, aryloxy e.g. trifluoromethylphenoxy, etc. Substituents on the carbon atom at position 17 include halogen atom e.g. chlorine, fluorine etc. Substituents on the carbon atom at position 20 include saturated and unsaturated lower alkyl e.g. C 1-6 alkyl, lower alkoxy e.g. C 1-4 alkoxy and lower alkoxy (lower) alkyl e.g. C 1-4 alkoxy-C 1-4 alkyl. Substituents on the carbon atom at position 5 include halogen atom e.g. chlorine, fluorine etc. Substituents on the carbon atom at position 6 include oxo group forming carbonyl. Stereochemistry of PGs having hydroxy, lower alkyl or lower (hydroxy) alkyl substituent on the carbon atom at position 9 and/or 11 may be alpha, beta or mixtures thereof.
Especially preferred compounds are those having a lower alkyl e.g. methyl, ethyl, propyl, isopropyl, butyl, hexyl, preferably C 2-4 alkyl and most preferably ethyl at position 20.
A group of preferred compounds used in the present invention has the formula ##STR2## wherein X and Y are hydrogen, hydroxy, halo, lower alkyl, hydroxy(lower)alkyl, or oxo, with the proviso that at least one of X and Y is a group other than hydrogen, and 5-membered ring may have at least one double bond, A is --COOH or its pharmaceutically acceptable salt or ester, R 1 is bivalent saturated or unsaturated, lower or medium aliphatic hydrocarbon residue which is unsubstituted or substituted with halo, oxo or aryl, R 2 is saturated or unsaturated, medium aliphatic hydrocarbon residue having 5 or more carbon atoms in the main or straight chain moiety which is unsubstituted or substituted with halo, hydroxy, oxo, lower alkoxy, lower alkanoyloxy, cyclo(lower)alkyl, aryl or aryloxy.
In the above formula, the term "unsaturated" in the definitions for R 1 and R 2 is intended to include at least one and optionally more than one double bond and/or triple bond isolatedly, separately or serially present between carbon atoms of the main and/or side chains. According to usual nomenclature, an unsaturation between two serial positions is represented by denoting the lower number of said two positions, and an unsaturation between two distal positions is represented by denoting both of the positions. Preferred unsaturation is a double bond at position 2 and a double or triple bond at position 5.
The term "lower or medium aliphatic hydrocarbon residue" or "medium aliphatic hydrocarbon residue" refers to a straight or branched chain hydrocarbyl group having 1 to 14 carbon atoms or 5 to 14 carbon atoms, respectively, (for a side chain, 1 to 3 carbon atoms being preferred) and preferably 2 to 8 carbon atoms for R 1 and 6 to 9 carbon atoms for R 2 .
The term "halo" denotes fluoro, chloro, bromo and iodo.
The term "lower" throughout the specification is intended to include a group having 1 to 6 carbon atoms unless otherwise specified.
The term "lower alkyl" as a group or a moiety in hydroxy(lower)alkyl, monocyclic aryl(lower) alkyl, monocyclic aroyl(lower)alkyl or halo(lower)alkyl includes saturated and straight or branched chain hydrocarbon radicals containing 1 to 6, carbon atoms, e.g. methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl and hexyl.
The term "lower alkoxy" refers to the group lower-alkyl-O-- wherein lower alkyl is as defined above.
The term "hydroxy(lower)alkyl" refers to lower alkyl as defined above which is substituted with at least one hydroxy group, e.g. hydroxymethyl, 1-hydroxyethyl, 2-hydroxyethyl and 1-methyl-1-hydroxyethyl.
The term "lower alkanoyloxy" refers to a group of the formula: RCO--O-- wherein RCO-- is an acyl group formed by oxidation of a lower alkyl group as defined above, e.g. acetyl.
The term "cyclo(lower)alkyl" refers to a cyclic group formed by cyclization of a lower alkyl group as defined above.
The term "aryl" includes unsubstituted or substituted aromatic carbocyclic or heterocyclic (preferably monocyclic) groups, e.g. phenyl, tolyl, xylyl and thienyl. Examples of substituents are halo and halo(lower)alkyl wherein halo and lower alkyl being as defined above.
The term "aryloxy" refers to a group of the formula: ArO-- wherein Ar is aryl as defined above.
Suitable "pharmaceutically acceptable salts" includes conventional non-toxic salts, and may be a salt with an inorganic base, for example an alkali metal salt (e.g. sodium salt, potassium salt, etc.) and an alkaline earth metal salt (e.g. calcium salt, magnesium salt, etc.), ammonium salt, a salt with an organic base, for example, an amine salt (e.g. methylamine salt, dimethylamine salt, cyclohexylamine salt, benzylamine salt, piperidine salt, ethylenediamine salt, ethanolamine salt, diethanolamine salt, triethanolamine salt, tris(hydroxymethylamino)ethane salt, monomethyl-monoethanolamine salt, procaine salt, caffeine salt, etc.), a basic amino acid salt (e.g. arginine salt, lysine salt, etc.), tetraalkyl ammonium salt and the like. These salts can be prepared by the conventional process, for example from the corresponding acid and base or by salt interchange.
Examples of the "pharmaceutically acceptable esters" are aliphatic esters, for example, lower alkyl ester e.g. methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, t-butyl ester, pentyl ester, 1-cyclopropylethyl ester, etc., lower alkenyl ester e.g. vinyl ester, allyl ester, etc., lower alkynyl ester e.g. ethynyl ester, propynyl ester, etc., hydroxy(lower) alkyl ester e.g. hydroxyethyl ester, lower alkoxy(lower)-alkyl ester e.g. methoxymethyl ester, 1-methoxyethyl ester, etc., and aromatic esters, for example, optionally substituted aryl ester e.g. phenyl ester, tosyl ester, t-butylphenyl ester, salicyl ester, 3,4-di-methoxyphenyl ester, benzamidophenyl ester etc., aryl(lower)alkyl ester e.g. benzyl ester, trityl ester, benzhydryl ester, etc. Examples of the amides are mono- or di- lower alkyl amides e.g. methylamide, ethylamide, dimethylamide, etc., arylamide e.g. anilide, toluidide, and lower alkyl- or aryl-sulfonylamide e.g. methylsulfonylamide, ethylsulfonylamide, tolylsulfonylamide etc.
Preferred examples of A include --COOH, --COOCH 3 , --COOCH 2 CH 3 and --COOCH(CH 3 ) 2 .
The configuration of the ring and the α- and/or omega chain in the above formula (I) may be the same as or different from that in the primary PGs. However, the present invention also includes a mixture of a compound having a primary configuration and that of an unprimary configuration.
Examples of the typical compounds of the present invention are 15-keto-PGs, 13,14-dihydro-15-keto-PGAs to Fs and their derivatives e.g. 20-loweralkyl-oxo-derivatives, Δ 2 -derivatives, 3R,S-methyl-derivatives, 6-oxo-derivatives, 5R,S-fluoro-derivatives, 5,5-difluoro-derivatives, 16R,S-methyl-derivatives, 16,16-dimethyl-derivatives, 16R,S-fluoro-derivatives, 16,16-difluoro-derivatives, 17S-methyl-derivatives, 17R,S-fluoro-derivatives, 17,17-difluoro-derivatives and 19-methyl-derivatives.
The component (a) may be in the keto-hemiacetal equilibrium by forming a hemiacetal between hydroxy group at position 11 and ketone at position 15.
The proportion of both tautomeric isomers, when present, varies depending on the structure of the rest of the molecule or kind of any substituent present and, sometimes, one isomer may predominantly be present in comparison with the other. However, in this invention, it is to be appreciated that the compounds used in the invention include both isomers. Further, while the compounds used in the invention may be represented by a structure or name based on keto-form regardless of the presence or absence of the isomers, it is to be noted that such structure or name does not intend elimination of the hemiacetal type of compounds.
In the present invention, any of the individual tautomeric isomers, a mixture thereof, or optical isomers, a mixture thereof, a racemic mixture, and other isomers such as steric isomers can be used in the same purpose.
Some of the compounds used in the present invention may be prepared by the method disclosed in Japanese Patent Publications (unexamined) No. A-52753/1989, A-104040/1989, A-151519/1989 and A-108/1990.
Alternatively, these compounds may be prepared by a process analogous to that described in the above publications in combination with the known synthetic method for the five-membered ring moiety.
In the process for preparing 13,14-dihydro-15-keto- compound:
A commercially available (-)-Corey lactone, which is used as a starting material, is subjected to Collins oxidation to give an aldehyde. The aldehyde is allowed to react with dimethyl (2-oxoalkyl)phosphonate anion to give an α, β-unsaturated ketone, and the resultant is reduced to ketone. The carbonyl group of the ketone is allowed to react with a diol to give a ketal, thereby protected, then a corresponding alcohol is obtained by elimination of the phenylbenzoyl group, and the resulting hydroxy group is protected with dihydropyran to give a tetrapyranyl ether. Thus, precursors of PGs wherein the ω-chain is 13,14-dihydro-15-keto-alkyl can be obtained.
Using the above tetrapyranyl ether as a starting material, 6-keto-PG 1 s of the formula: ##STR3## may be obtained as follows: The tetrapyranyl ether is reduced using diisobutyl aluminium hydride and the like to give a lactol, which is allowed to react with a ylide obtained from (4-carboxybutyl)triphenylphosphonium bromide, and the resultant is subjected to esterification followed by cyclization, combining the 5,6-double bond and the C-9 hydroxyl group with NBS or iodine, providing a halide. The resultant is subjected to dehydrohalogenation with DBU and the like to give a 6-keto compound, which is subjected to Jones oxidation followed by deprotection to give the objective compound.
Further, PG 2 s of the formula: ##STR4## may be obtained as follows: The above tetrapyranyl ether is reduced to the lactol, which is allowed to react with a ylide obtained from (4-carboxybutyl)triphenylphosphonium bromide to give a carboxylic acid. The resultant is subjected to esterification followed by Jones oxidation and deprotection to give the objective compound.
In order to obtain PG 1 s of the formula: ##STR5## using the above tetrapyranyl ether as a starting material, in the same manner as PG 2 of the formula: ##STR6## the 5,6-double bond of the resulting compound is subjected to catalytic reduction followed by deprotection.
To prepare 5,6-dehydro-PG 2 s containing a hydrocarbon chain of the formula: ##STR7## a monoalkyl copper complex or a dialkyl copper complex of the formula: is subjected to 1,4-addition with 4R-t-butyldimethylsilyloxy-2-cyclopenten-1-one, and the resulting copper enolate is seized with 6-carboalkoxy-1-iodo-2-hexyne or a derivative thereof.
PGs containing a methyl group instead of a hydroxy group at the C-11 position may be obtained as follows:
PGA obtained by Jones oxidation of the hydroxy group at the C-9 position of the 11-tosylate is allowed to react with a dimethyl copper complex to give 11-dehydroxy-11-methyl-PGE. Alternatively, an alcohol obtained after elimination of p-phenylbenzoyl group is converted to a tosylate. An unsaturated lactone obtained by DBU treatment of the tosylate is converted to a lactol. After introduction of an α-chain using Wittig reaction, the resulting alcohol (C-9 position) is oxidized to give PGA. PGA is allowed to react with dimethyl copper complex to give 11-dehydroxy-11-methyl-PGE. The resultant is reduced using sodium borohydride and the like to give 11-dehydroxy-11-methyl-PGF.
PGs containing a hydroxymethyl group instead of a hydroxyl group at the C-11 position is obtained as follow:
11-dehydroxy-11-hydroxymethyl-PGE is obtained by a benzophenone-sensitized photoaddition of methanol to PGA. The resultant is, for example, reduced using sodium borohydride to give 11-dehydroxy-11-hydroxymethyl-PGF.
16-Fluoro-PGs may be obtained using dimethyl (3-fluoro-2-oxoalkyl)phosphonate anion in the preparation of an α,β-unsaturated ketone. Similarly, 19-methyl-PGs may be obtained using a dimethyl (6-methyl-2-oxoalkyl)phosphonate anion.
The preparations in the present invention are not construed to be limited to them, and suitable means for protection, oxidation, reduction and the like may be employed.
The cholinergic agents used as the component (b) in the present invention refer to agents capable of causing excitation or inhibition of automic nervous effector cells governed by parasympathetic postganglinoic fiber and are also called parasympathomimetic agents. Representative example thereof include acetylcholine, cholinergic alkaloids and their analogues.
Preferred example are those commercialized as agents for treating glaucoma, ocular hypertension, or diagnostatic miotics, or agent for treating esotropia such as Pilocarpine, acetylcoline, Methacholine and Carbachol.
Since the component (a) has an activity of lowering ocular pressure without accompanying transient ocular hypertension as shown by the primary PGs, the combination of (a) and (b) can be used for the treatment of various disease and conditions in which lowering of ocular pressure is desirous, for example glaucoma, ocular hypertension and other disease which accompanies increase in ocular pressure.
As used herein, the term "treatment" or "treating" refers to any means of control of a disease in a mammal, including preventing the disease, curing the disease, relieving the disease and arresting or relieving the development of the disease.
The combination has an advantage, by containing the component (b) in addition to the component (a), that it has a synergistically increased ocular hypotensive action, thus enabling reduce in dosage, and/or lowering the side-effect.
The ratio (a):(b) in the combination varies, without limitation, ordinarily within the range 1:10 to 1:2000, preferably 1:50 to 1:1000 and most preferably 1:100 to 1:500.
While the dosage of the component (a) varies depending on condition of the component(a) varies depending on condition of the patient, severity of the disease, purpose of the treatment, judgement of the physician and total dosage of the combination, it is ordinarily within the range 0.005 to 2% and preferably 0.01 to 1% by weight.
The dosage of the component (b) varies, for example, depending on the concentration of the component (a) and ordinarily within the range 0.005 to 20% and preferably 0.01 to 10% by weight.
The combination according to the present invention can be administered in the form of a pharmaceutical composition containing the components (a) and (b) and optionally other ingredients conveniently used in the ophthalmic composition, such as carrier, diluent or excipient.
The ophthalmic composition used according to the invention includes liquids such as ophthalmic solution, emulsion, dispersion etc. and semisolids such as ophthalmic gel, ointment etc. Diluents for the aqueous solution or suspension include, for example, distilled water and physiological saline. Diluents for the nonaqueous solution and suspension include, for example, vegetable oils e.g. olive oil, liquid paraggine, mineral oil, and propylene glycol and p-octyldodecanol. The composition may also contain isotonization agents such as sodium chloride, boric acid, sodium citrate, etc. to make isotonic with the lacrimal fluid and buffering agents such as borate buffer, phosphate buffer, etc. to maintain pH about 5.0 to 8.0. Further, stabilizers such as sodium sulfite, propylene glycol, etc., chelating agents such as sodium edetate, etc., thickeners such as glycerol, carboxymethylcellulose, carboxyvinyl polymer, etc. and preservatives such as methyl paraben, propyl paraben, etc. may also be added. these can be sterilized e.g. by passing through a bacterial filter or by heating.
The ophthalmic ointment may contain vaseline, Plastibase, Macrogol, etc. as a base and surfactant for increasing hydrophilicity. It may also contain geling agents such as carboxymethylcellulose, methylcellulose, carboxyvinyl polymer, etc.
In addition, the composition may contain antibiotics such as chloramphenicol, penicilin, etc. in order to prevent or treat bacterial infection.
A more complete understanding of the present invention can be obtained by reference to the following Preparation Examples, Formulation Examples and Test Examples which are provided herein for purpose of illustration only and are not intended to limit the scope of the invention.
PREPARATIONS
Preparations of 13,14-dihydro-15-keto-20-ethyl-PGA 2 isopropyl ester, 13,14-dihydro-15-keto-20-ethyl-PGE 2 isopropyl ester and 13,14-dihydro-15-keto-20-ethyl-PGF 2 α isopropyl ester (cf. Preparation chart I):
1) Preparation of 1S-2-oxa-3-oxo-6R-(3-oxo-1-transdecenyl)-7R-(4-phenylbenzoyloxy)-cis-bicyclo[3.3.0]-octane (3):
Commercially available (-)-Corey lactone (1) (7 g) was subjected to Collins oxidation in dichloromethane to give aldehyde (2). The resultant was allowed to react with dimethyl (2-oxononyl)phosphonate (4.97 g) anion to give 1S-2-oxa-3-oxo-6R-(3,3-ethylendioxy-1-trans-decenyl)-7R-(4-phenylbenzoyloxy)-cis-bicyclo[3.3.0]-octane (3).
2) Preparation of 1S-2-oxa-3-oxo-6R-(3-oxodecyl)-7R-(4-phenylbenzoyloxy)-cis-bicyclo[3.3.0]-octane (4):
Unsaturated ketone (3) (7.80 g) was reduced in ethyl acetate (170 ml) using 5% Pd/C under hydrogen atmosphere. The product obtained after the usual work-up (4) was used in the following reaction.
3) Preparation of 1S-2-oxa-3-oxo-6R-(3,3-ethylenedioxy-decyl)-7R-(4-phenylbenzoyloxy)-cisbicyclo[3.3.0]-octane (5):
Saturated ketone (4) was converted to ketal (5) in dry benzene (150 ml) using ethylene glycol and p-toluenesulfonic acid (catalytic amount).
4) Preparation of 1S-2-oxa-3-oxo-6R-(3,3-ethylenedioxy-decyl)-7R-hydroxy-cis-bicyclo[3.3.0]-octane (6):
To a solution of ketal (5) in absolute methanol (150 ml) was added potassium carbonate (2.73 g). The mixture was stirred overnight at room temperature. After neutralization with acetic acid, the resultant was concentrated under reduced pressure. The resulting crude product was extracted with ethyl acetate. The organic layer was washed with a dilute aqueous solution of sodium bicarbonate and a saline, and dried. The crude product obtained after evapolation was chromatographed to give alcohol (6). Yield; 3.3 g
5) Preparation of lactol (7):
Alcohol (6) (0.80 g) was reduced in dry toluene (8 ml) using DIBAL-H at -78 ° C. to give lactol (7).
6) Preparation of 13,14-dihydro-15,15-ethylenedioxy-20-ethyl-PGF 2 α (8):
A DMSO solution of lactol (7) was added to ylide prepared from (4-carboxybutyl)triphenylphosphonium bromide (3.65 g). The reaction mixture was stirred overnight to give carboxylic acid (8).
7) Preparation of 13,14-dihydro-15,15-ethylenedioxy-20-ethyl-PGF 2 α isopropyl ester (9):
Carboxylic acid (8) was converted to 13,14-dihydro-15,15-ethylenedioxy-20-ethyl-PGF 2 α isopropyl ester (9) using DBU and isopropyl iodide in acetonitrile.
Yield; 0.71 g
8) Preparation of 13,14-dihydro-15-keto-20-ethyl-PGF 2 α isopropyl ester (10):
13,14-Dihydro-15,15-ethylenedioxy-20-ethyl-PGF 2 α isopropyl ester (9) (0.71 g) was kept in acetic acid/THF/water (3/1/1) at 40 ° C. for 3 hours. The crude product obtained after concentration under reduced pressure was chromatographed to give 13,t4-dihydro-15-keto-20-ethyl-PGF 2 α isopropyl ester (10).
Yield; 0.554 g
9) Preparation of 13,14-dihydro-15-keto-20-ethyl-PGA 2 isopropyl ester (12):
A solution of 13,14-dihydro-15-keto-20-ethyl-PGF 2 α isopropyl ester (10) (0.125 g) and p-toluenesulfonyl chloride (0.112 g) in pyridine (5 ml) was maintained at 0° C. for 2 days According to the usual work-up, osylate (11) was obtained.
Tosylate (11 ) was subjected to Jones oxidation in acetone (8 ml) at -25° C. The crude product obtained the usual work-up was chromatographed to give 13,14-dihydro-15-keto-20-ethyl-PGA 2 α isopropyl ester (2)
Yield; 0.060 g
10) Preparation of 13,14-dihydro-15,15-ethylenedioxy-20-ethyl-11-t-butyldimethylsiloxy-PGF.sub.2 α isopropyl ester (13):
13,14-Dihydro-15,15-ethylenedioxy-20-ethyl-PGF 2 α isopropyl ester (9) (3.051 g) was dissolved in dry N,N-dimethylformamide (25 ml), t-butyldimethylsilyl chloride (1.088 g) and imidazole (0.49 g) was added thereto. The resultant was stirred at room temperature overnight. The reaction mixture was concentrated under reduced pressure, and the resulting crude product was chromatographed to give 13,14-dihydro-15,15-ethylenedioxy-20-ethyl-11-t-butyldimethylsiloxy-PGF.sub.2 α isopropyl ester (13).
Yield; 2.641 g
11) Preparation of 13,14-dihydro-15,15-ethylenedioxy-20-ethyl-11-t-butyldimethylsiloxy-PGE.sub.2 α isopropyl ester (14):
13,14-Dihydro-15,15-ethylenedioxy-20-ethyl-11-t-butyldimethylsiloxy-PGF.sub.2 α isopropyl ester (13) (1.257 g) was subjected to Jones oxidation at -40 ° C. After the usual work-up, the resulting crude product was chromatographed to give 13,14-dihydro-15,15-ethylenedioxy-20-ethyl-11-t-butyldimethylsiloxy-PGE.sub.2 α isopropyl ester (14).
Yield; 1.082 g
12) Preparation of 13,14-dihydro-15-keto-20-ethyl-PGE 2 isopropyl ester (15):
To a solution of 13,14-dihydro-15,15-ethylenedioxy-20-ethyl-11-t-butyldimethylsiloxy-PGE.sub.2 isopropyl ester (14) in acetonitrile was added hydrofluoric acid (46% aqueous solution). The mixture was stirred at room temperature for 40 minutes. The crude products obtained after usual work-up was chromatographed to give 13,14-dihydro-15-keto-20-ethyl-PGE 2 isopropyl ester (15).
Yield; 0.063 g (97%) ##STR8##
TEST EXAMPLE 1
Japanese white rabbits (weight: 2.5-3.5 kg, 6 animals/group) were fixed and eyes were anesthetized by dropping 0.4% oxybuprocaine hydrochloride to eyes. The ocular pressure measured at 0.5-1 hour after the fixation was taken as the 0 hour value and values of pressure thereafter were measured in the course of time administering by eye-dropping each 50 μl of the following formulations. An electronic pneumatonometer (Alcon) was used for measurement. Decrease in ocular pressure (mean value) at 5 hours after administration of each of the formulations was compared in the Table 1.
Formulation Example 1 (Comparative)
______________________________________Pilocarpine hydrochoride 2.0 gSterilized water q.s. to 100 ml______________________________________
Formulation Example 2 (Comparative)
______________________________________Isopropyl (Z)-7-[(1R,2R,3R,5S)-3,5- 0.01 gdihydroxy-2-(3-oxodecyl)cyclopentyl]-hept-5-noate [13,14-dihydro-15-keto-20-ethyl-PGF.sub.2 α isopropyl ester,hereinafter referred to as Compound A]Sterilized water q.s. to 100 ml______________________________________
Formulation Example 3
______________________________________Pilocarpine hydrochloride 2.0 gCompound A 0.01 gSterilized water q.s. to 100 ml______________________________________
TABLE 1______________________________________ Decrease in ocular pressure (mmHg)______________________________________Formulation 1 0Formulation 2 -0.3Formulation 3 -2.5______________________________________
The above results show that the combined use of Pilocarpine hydrochloride and Compound A result in a synergistic effect. | 4y
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RELATED APPLICATIONS
This application is a National Phase application of PCT/FR2010/051871, filed on Sep. 8, 2010, which in turn claims the benefit of priority from French Patent Application No. 09 56168 filed on Sep. 9, 2009, the entirety of which are incorporated herein by reference.
BACKGROUND
1. Field of the Invention
The present invention relates to a process for producing a composite for use as a positive electrode, based on iron phosphate and in particular LiFePO 4 , via extrusion in the presence of water or a mixture of water and at least one water-miscible solvent, to the positive electrode obtained by implementing this process and to its applications.
2. Description of Related Art
The invention relates to the field of manufacturing lithium metal polymer (LMP) batteries. This type of battery takes the form of a set of thin films rolled up n times (rolls of the following structure: electrolyte/cathode/collector/cathode/electrolyte/lithium) or of multilayers of n thin films (cut and superposed, or n multilayers of the aforementioned configuration). This unitary stacked/complexed configuration has a thickness of about one hundred microns. It comprises 4 functional sheets: i) a negative electrode (anode) generally consisting of a lithium-metal or lithium-alloy foil, ii) an electrolyte composed of a polymer (generally polyoxyethylene (POE)) and lithium salts, iii) a positive electrode (cathode) composed of an active electrode material based on metal oxide (for example V 2 O 5 , LiV 3 O 8 , LiCoO 2 , LiNiO 2 , LiMn 2 O 4 and LiNi 0.5 Mn 0.5 O 2 etc.) or based on a phosphate of the LiMPO 4 type where M represents a metal cation selected from Fe, Mn, Co, Ni and Ti or combinations of these cations, such as for example LiFePO 4 , on carbon and on a polymer, and finally iv) a current collector generally consisting of a metal foil and enabling electrical connection.
Processes for producing thin cathode films for lithium batteries generally consist in mixing the active electrode material, which is commonly in powder form, with an electrically conductive material, such as carbon or graphite particles or a mixture of the two, and a polymer binder in an organic solvent to form a homogenous paste. This paste is then applied to a current collector to form a thin film and then the organic solvent is evaporated by heating. The electrode film obtained by these processes is generally porous and contains no electrolyte. This thin cathode film is then joined with the other elements of the battery and then the assembly is saturated with an ionically conductive liquid electrolyte comprising a lithium salt. The porous film forming the cathode is then filled with the electrolyte so as to enable ion exchange between the cathode and the anode.
Other processes for producing thin films of positive-electrode material for solid-state lithium (LMP) batteries employ a mixture incorporating an electrolyte consisting of a solvating polymer and a lithium salt. The mixture comprises the active-electrode material in particle form, the electrically conductive material, the solvating polymer and the lithium salt mixed in an organic solvent to form a homogenous electrode paste. This paste is then applied to a current collector to form a film or thin film, and then the organic solvent is evaporated by heating so as to form the electrode. The positive electrode obtained in this way has a low porosity insofar as the electrolyte is initially introduced into the electrode material before evaporation of the solvent and fills the spaces between the particles of active-electrode material. This positive-electrode film is then joined with a solid ionically conductive separator (polymer electrolyte) and a negative counter electrode in order to form the solid lithium battery.
In both cases, organic solvents are used to reduce the viscosity of the mixture used to manufacture the cathode and allow the electrode paste to be applied to the current collector in the form of a thin film. The organic solvents must then be removed, most often by evaporation after heating, before the various components of the battery are joined together. When this type of electrode is manufactured on an industrial scale or by a continuous process, the evaporated organic solvents must be recovered so as not to pollute the environment. Processes for recovering organic solvents require special facilities to prevent solvent vapor from escaping into the environment, and equipment suited to storing and handling these solvents in large amounts during their use.
Replacing the organic solvents used in these processes with a nonpolluting solvent such as water has already been envisioned, especially in international application WO 2004/045007. According to this process, a support is coated with an aqueous solution containing an active positive-electrode material and a binder consisting of a water-soluble synthetic rubber mixed with a thickening agent. It is then necessary to dry the deposited film on the support for a time of at least 12 to 24 hours so as to reduce the water content down to a value lower than 2000 ppm and preferably lower than 50 ppm. It is not possible to incorporate lithium salts into this solution insofar as these salts, due to their hygroscopic properties, would retain water present in the film and further increase the time required by the drying step to remove the water after coating the aqueous solution on the support. In this case, the film obtained is therefore porous so as to allow it to be subsequently impregnated with a lithium salt during assembly with the other components of the battery and enable ion exchange between the cathode and the anode. The process described in international application WO2004/045007 can therefore not be used to produce lithium-based batteries which require the lithium salt to be incorporated into the positive-electrode material before it is joined with the other components of the battery.
It is also possible to produce positive electrodes by dry (solventless) extrusion. In this case, the various components of the composition of the electrode material are introduced into a single-screw or twin-screw extruder and then extruded through a flat die onto a support. The mixture of the various components of the electrode material however has a high viscosity, thereby generally limiting the content of active electrode material that it is possible to incorporate. Thus, in the case where LiFePO 4 is used as active positive-electrode material, the maximum percentage that can be incorporated into the final electrode material is about 65%, more commonly lower than 60% of the total dry weight of the electrode. It is generally not possible, in this respect, to raise the temperature to decrease the viscosity of the system during the extrusion because of the very nature of the polymer used (a polyether), which is sensitive to heat and would be degraded. Moreover, the primary obtained, generally a few hundred microns in thickness, must be rolled or calendered to obtain an electrode film a few tens of microns in thickness, generally ≦65 μm in thickness depending on the applications targeted. This rolling or calendering step cannot generally be carried out directly on the current collector because the compressive and shear stresses related to the viscosity are too great and most often cause the current collector to break (aluminum collector <30 μm in thickness). It is therefore necessary, in a first step, to produce the electrode material and to then continue with an additional step called a complexing step (thermocompression bonding of the cathode to the collector) during which step the material is joined to the current collector. In this context of “stepped” complexing, it is generally more difficult to obtain an optimal quality for the interface between the electrode material and the current collector, whereas in the case of direct rolling or calendering of the electrode material extruded onto the current collector, the rolling or calendering stresses, in addition to their thickness sizing function, strengthen the adhesion of the electrode film to the surface of the collector and thus create a better-quality interface, increasing the homogeneity and quality of electron exchange within the battery.
OBJECTS AND SUMMARY
There is therefore a need for a process for producing a positive-electrode material based on iron phosphate, and in particular based on LeFePO 4 , that makes it possible:
to obtain cathodes having a high active-material content, generally higher than 60%, preferably higher than 70%, while minimizing their porosity; to deposit the cathode material directly on the current collector, without requiring a complexing step; to obtain cathode films having a thickness smaller than 100 μm, preferably smaller than 65 μm; to obtain quality films (homogenous, tow-porosity films, as mentioned above, having a uniform thickness profile over the entire width without thinning at the edges and providing good electrochemical performance); and to allow, when so desired, lithium salts to be incorporated into the mixture of electrode constituents before the electrode is joined to the other components of the battery.
One subject of the present invention is therefore a process for producing a positive electrode consisting of a composite comprising the following ingredients:
at least one active positive-electrode material chosen from iron-phosphate-based materials; at least one water-soluble polymer that conducts ions in the presence of a lithium salt; and optionally at least one material providing electrical conduction properties,
said process comprising at least one step of mixing, by extrusion, the ingredients of the composite so as to obtain an extruded composite, at least one step of forming the composite extruded through a die, at least one step of rolling or calendering the extruded composite into the form of a positive-electrode film on a current collector, and at least one step of drying the positive--electrode film applied to the current collector,
said process being characterized in that the extrusion step is carried out by means of a co-kneader, a twin-screw extruder or a multi-screw extruder (number of screws >2) in the presence of an aqueous solvent consisting of demineralized or distilled water or of a mixture of demineralized or distilled water and at least one water-miscible solvent representing at most 30 wt % of the total weight of the aqueous solvent, said aqueous solvent representing approximately from 3 to 25 wt % of the total weight of the ingredients forming the composite, and at a temperature from 20 to 95° C.
The process according to the invention has the following advantages:
the aqueous solvent is used as an additive to make extrusion easier by acting as a plasticizer that lowers the viscosity of the mixture without requiring a temperature increase, thereby permitting a tow extrusion temperature compatible with the use of heat-sensitive polymers (extrusion temperature of 20 to 95° C.); the modular nature of the screw profile, of the temperature profile and of the supply configurations make it possible to employ various formulations and select/refine the properties of the cathode; reducing the viscosity and the extrusion temperature limits the mechanical and thermal stresses customarily exerted in dry extrusion in order to melt the material and coat the feedstock; consequently, it is not absolutely necessary to add antioxidants to the positive-electrode composite; and it makes it possible to obtain cathodes having a high active-material content, in general higher than 60%, preferably higher than 70%, while limiting their porosity and to obtain cathode films having a thickness smaller than 100 μm, preferably smaller than 65 μm.
Compared to processes for producing electrode materials by dry extrusion, the process according to the invention has the following advantages:
the stresses generated by dry extrusion generally act to degrade the polymer, which may, in addition, generate pollutants that are liable to interfere, in fine, with the electrochemistry; the mixing step, in the extruding equipment, is carried out in line with the step of rolling or calendering the composite extruded on the current collector; direct rolling or calendering of the material extruded on the current collector ensures cohesion and a high-quality interface. The process according to the invention permits the rolling or calendering of a cathode film <65 μm in thickness on a current collector for example consisting of an aluminum substrate about fifteen microns in thickness. By modulating the viscosity, it is possible to roll or calendar a cathode film on aluminum substrates having a thickness of ≦12 μm; and the low viscosity of the mixture of ingredients forming the extruded composite makes clearing of the die at the outlet of the extruder, then rolling or calendering in line, easier and allows a cathode film having a stable width to be directly obtained. Thus, the process according to the invention makes it possible to manufacture cathodes more than 700 mm in width without trimming being necessary to obtain a constant-width film.
Therefore, the wet process according to the invention consumes less power, causes less wear to the equipment and is less “disruptive” regarding the polymer and the electrochemistry.
The extrusion step is preferably carried out at a temperature from 35 to 80° C.
According to one preferred embodiment of the invention, the extrusion step is carried out by means of a twin-screw extruder.
The twin-screw extruder possibly used according to the process of the invention is preferably a corotating twin-screw extruder.
In this case, the twin-screw extruder possibly used in the process preferably comprises a sectional, modular barrel consisting of about ten blocks in succession, each block being individually controlled to a specific selected temperature and in which blocks two parallel screws rotate, a variable-speed gearmotor driving the screws, one or more variable feed rate supply devices (weigh or volume feeders) intended to supply the extruder with the ingredients making up the composition of the electrode composite, a system for introducing the liquid aqueous solvent (gravimetric device or liquid injection pump dedicated to introducing the aqueous solvent into the extruder), and optionally one or more side feeders for supplying the ingredients to the twin-screw chamber. The twin-screw extruder is furthermore equipped with various hoppers (for the aforementioned feeders and supply devices), with one or more specific barrel assemblies dedicated to the optional connection of one or more liquid injection nozzles, and optionally with one or more barrel assemblies intended to receive the one or more connections of a side feeder. These various modular devices can be placed along the twin-screw, depending on the configuration chosen. Because it is possible to dedicate a feeder to each ingredient of the composition of the mixture to be extruded, it is possible to use either granules or powder depending on the type of feeder selected.
The twin-screw extruder ensures that the various ingredients are mixed, with a view to obtaining a homogenous paste, by combining shear stresses, applied to the ingredients, and dispersive and distributive mixing. The quality of the final mixture essentially depends on the elements forming the screw profile, especially the kneaders, on the fill level, and on the shear rates involved. In parallel, reducing the viscosity obtained by adding water makes it possible to limit the mechanical and thermal stresses on the polymer matrix while passing through the various kneader blades, and therefore to prevent self-heating that is likely to degrade the one or more heat-sensitive water-soluble polymers. The shear stress and the dispersive/distributive mixing are modulated by the twin-screw elements and by their nature, number, state and arrangement along the screw. It is mainly the type of kneaders chosen (single lobe, double lobe, triple lobe, etc.), the lobe width (apex of the lobe on which the shear forces act), the angle between the axis of the lobes of 2 successive kneading elements (which is adjustable depending on the dispersive/distributive effect desired), and the distribution of these kneaders along the screw that may be used to adjust the quality of the mixture for a given supply configuration. Special elements such as reverse steps or crenellated lobes can also be employed to optimize the mixture depending on the formulation, on the properties of the polymer, on the type and structure of the fillers, and on the final properties desired.
The invention may be applied to small laboratory-type twin-screw extruders (for example extruders of 18 mm diameter) and to industrial extruders the diameter of which may be greater than 200 mm. These extruders generally have a length (L)-to-diameter (D) ratio (L/D) of between 25 and 55 and comprise about ten zones (generally from 7 to 13 zones).
Among the water-miscible solvents that can optionally be used in the aqueous solvent, mention may be made of glycols and lower alcohols such as methanol, ethanol, propanol and butanol. Among such solvents, ethanol is preferred.
When it is present, the water-miscible solvent preferably represents less than 15 wt % of the total weight of the aqueous solvent.
According to another preferred embodiment of the invention, the amount of aqueous solvent used in the extrusion step varies approximately from 8 to 15 wt % of the total weight of the ingredients forming the composite.
If it is desired to modulate the mixing parameters it is possible to introduce the aqueous solvent into the extruder either at a number of points or in a number of separate zones. A first mixing substep may be carried out on a still relatively viscous paste, so as to intensify the dispersive and distributive mixing; other successive introduction substeps can then be carried out, thereby allowing the viscosity to be gradually lowered so as to continue gently mixing the mixture. Generally, it is possible to modulate the viscosity of the cathode paste depending on the process, the formulation and the desired properties, by varying the percentage amount of aqueous solvent introduced into the twin-screw.
For typical mixtures tested at a temperature of 70° C., viscosities are about 500 to 1000 Pa·s for a shear rate of about 500 s −1 , 100 to 500 Pa·s for a shear rate of about 1000 s −1 generally less than 250 Pa·s for a shear rate >2000 s −1 (which reveals thixotropic behavior, in other words the viscosity decreases with the shear rate). These viscosity measurements were carried out using an RH 2200® twin-bore capillary rheometer, sold by Rosand, which allowed Bagley and Rabinowitch corrections to be incorporated.
Introduction of the aqueous solution in a defined amount may also be carried out gravimetrically in the one or more suitable zones of the extruder.
According to another preferred embodiment of the invention, a device for increasing and stabilizing the pressure is positioned at the outlet of the extruder, in front of the die in order to ensure that the die is cleared and that a uniform primary is obtained. By way of such devices, mention may be made for example of single-screw rework extruders and gear extrusion pumps (melt pumps).
According to another embodiment of the invention, a single-screw rework extruder is used having a temperature profile of 20 to 95° C. The rotation speed will be set depending on the feed rate and the size of the single-screw, according to the general knowledge of a person skilled in the art.
Next, a die, generally cylindrical or flat, placed downstream of the device for increasing and stabilizing the pressure at the end of the extrusion line, presents the extrudate to the input of the rolling or calendering device. According to the present invention, a flat die is preferably used, the shape of which resembles the geometry of the final product (positive electrode) and promotes production of a stable width.
The extrudate exiting the die is then rolled or calendered on the current collector. To solve the possible problem of bonding of the cathode to the rollers, it is possible to use a protective film that runs at the rolling or calendering speed (for example a polypropylene (PP) or polyethylene terephthalate (PET) film or plastic films having nonstick properties). This film is then removed before the drying operation. It is possible to recycle this film a number of times because it is not mechanically and thermally stressed to a great extent during the rolling or calendering step. An alternative solution consists in using a nonstick belt that runs on the roller in contact with the extrudate. It is also possible to use rollers made of a nonstick material or employing nonstick coatings compatible with the surface finish desired for the final product.
In another preferred embodiment of the invention, the die is located near the rolling system. The extrudate or primary a few hundred microns in thickness is rolled or calendered to the thickness required to obtain the target thickness once the composite is dried. It is possible to adjust the temperature, gap and pressing force of the rolling or calendering equipment.
According to another preferred embodiment of the invention, the rolling or calendering step is carried out in rolling or calendering equipment consisting of two rollers that rotate in opposite directions. The temperature of each roller may be individually controlled in a range from 15 to 95° C. The linear speed depends on the feed rate of the input material and on the width and thickness of the targeted product. Optimization of the distance between the die and the rolling or calendering equipment makes it possible to control the introduction of the extrudate between the rollers and to stabilize the final width.
In another preferred embodiment of the invention, the residence time of the water in the composite is minimized, especially so as to prevent degradation of the active iron-phosphate-based material. It is also necessary to minimize the residence time of the water when the undried extruded composite is in contact with the current collector so as to prevent certain corrosion effects likely to occur in the presence of water on certain collectors depending on their coating. This is why the drying step is preferably carried out in line, in order to preserve the integrity of the product and to optimize its quality but also to meet industrial throughput requirements.
According to the process in accordance with the invention, the various ingredients forming the composite are added directly to the extruder (it is not necessary to make particular preparations or to prepare mixtures beforehand).
The ingredients of the composition of the electrode composite may then be introduced into the extruder in the form of a mixture contained in a single weigh or volume feeder or else distributed, singly or in groups, in different weigh or volume feeders placed in series relative to one another. Alternatively to gravimetric supply, it is also possible to connect one or more of these feeders to one or more side feeders secured to the extruder and allowing the one or more desired raw materials to be delivered to the extruder. This type of arrangement is widely used in extrusion to ensure the uniform introduction of products that are possibly difficult to supply gravimetrically.
According to another preferred embodiment of the invention, the active positive-electrode material, the water-soluble polymer and the material providing electrical conduction properties are each contained in different feeders and introduced, in succession and/or simultaneously, into various selected zones of the extruder, downstream or upstream of the zone for introducing the aqueous solvent.
The introduction of the aqueous solvent in a defined amount can be carried out gravimetrically in the one or more suitable zones of the extruder. The aqueous solvent is preferably injected directly into the extruder, by means of a liquid injection pump.
According to another preferred embodiment of the invention, the extrusion is carried out at a feed rate of 2 to 200 kg of the mixture of the ingredients (solid content) of the composition of the electrode material per hour. Thus, and by way of example, for a feed rate of solid ingredients of 100 kg/h to which about 12 wt % of aqueous solvent is added, the total feed rate (solid ingredients+aqueous solvent) is then about 113.6 kg/h.
The active electrode material is preferably LiFePO 4 in the form of uncoated particles or particles comprising a carbonaceous coating. In the latter case, it is not necessary to add a material providing electrical conduction properties to the mixture of ingredients of the composition of the composite, or a smaller amount is required, because of the presence of carbon on the surface of the LiFePO 4 particles.
The active electrode material preferably represents approximately from 60 to 85 wt %, and more preferably approximately from 70 to 80 wt %, of the total weight of the ingredients of the composition of the composite in the solid state.
The water-soluble polymer possibly used according to the invention preferably takes the form of a powder, of granules or of an aqueous dispersion. It is preferably chosen from polyethers such as polyoxyethylene (POE), polyoxypropylene and polyoxybutylene polymers, copolymers and terpolymers.
This polymer preferably represents approximately from 10 to 30 wt %, and more preferably approximately from 15 to 25 wt %, of the total weight of the ingredients of the composition of the composite in the solid state.
The material providing electrical conduction properties is possibly carbon, preferably chosen from carbon blacks, such as acetylene black or high-specific-surface-area carbon blacks, such as the products sold under the name Ketjenblack® EC-600M by AkzoNobel, carbon nanotubes, graphite or mixtures of these materials. It may be an aqueous dispersion of carbon black or of graphite such as the product sold under the trade name Electrodag® EB-012 by Acheson.
According to the invention, the material providing electrical conduction properties preferably represents approximately from 0 to 10 wt % when low-specific-surface-area carbons are used (by way of indication, specific surface areas below 200 m 2 /g) or approximately between 0 and 2.5 wt % when high-specific-surface-area carbons are used (by way of indication, specific surface areas above 1000 m 2 /g), said percentages being expressed relative to the total weight of the ingredients of the composition of the composite in the solid state. The percentage of carbon is modulated as a function of the amount of carbon already optionally incorporated in the LiFePO 4 particles. The use of LiFePO 4 particles sufficiently coated with carbon makes it possible to obviate the need to add a carbonaceous filler. In contrast, the use of bare LiFePO 4 particles generally means that a conductive material must be incorporated.
To function electrochemically, the positive-electrode composite must contain at least one material providing ionic conduction properties. This material may be a lithium salt especially chosen from LiAlCl 4 , Li 2 Al 2 Cl 6 O, LiClO 4 , LiPF 6 , LiAsF 6 , LiBF 4 , LiCF 3 SO 3 , LiSbF 6 , LiSbCl 6 , Li 2 TiCl 6 , Li 2 SeCl 6 , Li 2 B 10 Cl 10 , Li 2 B 12 Cl 12 , LiBOB, LiBETI, LiFSI, and LiTFSI.
The final content of lithium salt preferably varies approximately from 3 to 10 wt %, more preferably approximately from 4 to 8 wt %, of the total weight of the electrode composite after drying of the film.
According to a first variant of the invention, the lithium salt is added to the ingredients of the composition of the electrode composite in the extrusion step. In this case, it is a nonhydrolyzable water-soluble salt (counterion stable in water), such as, LiTFSI, LiClO 4 or LiBETI.
According to one particular preferred embodiment of the process of the invention, the aqueous solvent used. in the extrusion step then contains said lithium salt in solution. Using an aqueous solvent comprising a lithium salt has the advantage of limiting the drawbacks associated with handling powdered salt (risks of contamination and formation of an adhesive/deliquescent product in a non-anhydrous atmosphere).
According to a second variant of the invention, the lithium salt is incorporated into the electrode composite a posteriori, i.e. after the step of drying the film, by diffusing from an electrolyte after the latter has been brought into contact with the surface of the electrode film.
According to the invention, the rolling or calendering step is carried out directly on at least one of the two faces of a current collector, via action on the composite extruded as outlet from the die. This rolling or calendering step is preferably carried out at a temperature from 20 to 95° C., and more preferably from 30 to 70° C.
The composite film applied to the current collector preferably has a thickness of about 100 μm or less, and more preferably of about 65 μm or less.
The current collector for the positive electrode generally consists of an aluminum foil having a thickness ranging from 4 μm to 30 μm, preferably from 5 to 15 μm, furthermore possessing protective anticorrosion layers on each of the faces making contact with the electrode composite, so as to prevent any chemical reaction on contact with its constituents, especially with the lithium salt, whether the latter is one of the ingredients introduced into the twin-screw of the extruder or whether it is added subsequently during assembly of the various components of the battery. This protective anticorrosion layer may for example consist of an electrically conductive lacquer that is chemically inert with respect to the components of the cathode, or else a coating that is chemically inert with respect to the components of the cathode, such as for example a gold layer or a titanium nitride layer.
The step of drying the film applied to the current collector is preferably carried out in line. It has the aim of removing the water used in the extrusion step present in the film. Various film-drying techniques conventionally used in the field and well known to those skilled in the art may be employed, optionally in combination, in the drying step. Among such techniques, mention may especially be made of conductive, convective and radiative heating.
According to one preferred embodiment of the process according to the invention, the drying of the film applied to the current collector (foil) is carried out by convective heating in a (trying oven incorporating the horizontal-float (self-supporting) technique, i.e. in a drying oven equipped with upper and lower air knives placed in series relative to one another ensuring support of the foil also called a drying tunnel.
In this case, the current collector supporting the composite film introduced into the oven is self-supported, i.e. it is held at a given height in the oven by the air knives directed alternately towards the lower surface and the upper surface of the film. These air knives are emitted by blower nozzles placed alternately on either side of the film so as to ensure the support of the sheet without any mechanical contact with the nozzles and/or the other mechanical parts of the oven. Such an oven generally consists of various individually temperature-regulated zones making it possible to give the drying air a temperature profile and to control the air speed by adjusting the blowing pressure/flow rate at the nozzles. The film passes through the oven at the rolling or calendering speed fixed for a given feed rate and a given cathode format. The water is removed from the film by forced convective heating. A dehumidification system may also be incorporated into the oven so as to dry the air entering the dryer in order to optimize the water absorbing capacity of the air. By way of example, it is especially possible to use a drying tunnel comprising a plurality of separate drying zones each a few meters in length, in which the air is heated. Generally, the temperature of the air may vary from 60° C. to 200° C., and the speed of the air blown from the nozzles is about 25 to 50 m/s in each of the zones, In each temperature zone, the airflow speed may be specifically fixed in order to remove a maximum amount of the aqueous-solvent molecules present in the film without causing its deformation and without creating porosity. Each of these zones removes an increasingly large amount of aqueous solvent until a substantially dry film is obtained, i.e. a film containing less than 1000 ppm, and more preferably less than 600 ppm of water, The drying tunnel may of course comprise a greater or lesser number of drying zones depending on its geometry and its useful length, and the temperature levels required to dry the film well.
Another subject of the invention is the positive electrode obtained according to the process described above. It is characterized in that it takes the form of a composite film in which the active electrode material is a material based on iron phosphate, preferably LiFePO 4 , and in that:
the active electrode material content is higher than 60 wt %, preferably higher than 70 wt %, of the total weight of the electrode in the solid state; its thickness is smaller than 100 μm, preferably smaller than 65 μm; its porosity is lower than 3%, preferably lower than 1%; and its water content is lower than 1000 ppm, preferably lower than 600 ppm.
The electrode according to the invention may be provided in a number of widths typically varying from the smallest widths, i.e. about a centimeter, up to values possibly larger than 700 mm. Specifically, implementation of the process according to the present invention makes it possible to obtain large widths, larger than was generally possible using the known processes of the prior art, and without a detrimental alteration of the intrinsic properties of the positive electrode being observed.
Another subject of the invention is the use of a positive electrode as defined above, for manufacturing a lithium battery, in particular an LMP battery.
Finally, another subject of the invention is a lithium battery comprising at least one positive electrode, one negative electrode, an electrolyte and a current collector, characterized in that the positive electrode is an electrode such as defined above.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a twin screw extruder in accordance with one embodiment; and
FIG. 2 is a scanning electron microscope (SEM) miscrograph showing the electrode film of Exhibit 1 in accordance with one embodiment.
DETAILED DESCRIPTION
The present invention is illustrated by the following exemplary embodiment, to which it is however not limited.
EXAMPLES
Example 1
Preparation of a Positive Electrode According to the Process of the Invention
In this example, a positive electrode was produced with the process according to the invention, at a feed rate of 10 kg/h, using a corotating twin-screw extruder equipped with a number of weigh feeders one of which was connected to a side feeder, a liquid injection pump, a rework single-screw extruder coupled to a flat die, a unit for rolling the electrode onto a current collector and a drying tunnel.
The arrangement used is shown in annexed FIG. 1 in which a twin-screw extruder ( 1 ) 1.1 meters in length, comprising 10 zones and having a diameter of 25 mm is supplied with solid ingredients by weigh feeders ( 2 a, 2 b, 2 c ) and with aqueous solvent (demineralized water+LiTFSI) by a liquid, injection pump ( 3 ), the extruder ( 1 ) is coupled to a rework single-screw extruder ( 4 ) having a diameter of 30 mm, itself equipped with a flat die ( 5 ), opening onto a rolling station ( 6 ) and ending in a forced-convection drying oven ( 7 ).
The positive electrode was prepared by introducing a polyethylene oxide)/poly(butylene oxide) copolymer in the form of granules, sold under the trade name HQSEB by Dai-Ichi Kogyo Seiyaku (DKS), into the feeder ( 2 a ), introducing high-specific-surface-area carbon particles sold under the trade name Ketjen Black EC-600 JD by AkzoNobel into the feeder ( 2 b ), and introducing LiFePO 4 particles into the feeder ( 2 c ) connected to the side feeder. The feed rates of the weigh feeders were adjusted so as to obtain, after mixing in the extruder and before drying, an extruded composite containing 16.4 wt % of polymer, 1.3 wt % of carbon particles and 65.1 wt % of LiFePO 4 . The contents of feeders ( 2 a ), ( 2 b ) and ( 2 c ) were introduced in succession into the twin-screw ( 1 a and 1 b ). Demineralized water containing 30 wt % of LiTFSI was also introduced by means of the liquid injection pump ( 3 ) into the twin-screw ( 1 c ), in a sufficient amount to obtain, after all the ingredients had been mixed in the twin-screw of the extruder ( 1 ), an extruded composite containing 10 wt % of water. The total dry feed rate was adjusted to 10 kg/h, i.e. a feed rate of about 11.1 kg/h taking account of the weight of injected water. The extrusion was carried out at a temperature of 80° C. while the twin-screw was rotated at about 220 rpm. The composite resulting from the extrusion was then reworked by the rework single-screw ( 4 ) at a rate of 25 rpm and at a temperature of 80° C. and delivered to the flat die ( 5 ) before the final step of rolling ( 6 ) in which the extruded mixture was rolled onto a current collector consisting of an aluminum foil 15 μm in thickness coated on each face with an electrically conductive protective lacquer having a thickness of 2 μm and made of 30 wt % of acetylene black and 70 wt % of polyvinylidene fluoride/hexafluoropropylene (PVDF-HFP) at a rolling rate of 4.5 m/min. The film of extruded material applied to the current collector was then dried in line, so as to remove the water, by passing it through a forced-convection drying oven ( 7 ) 6 meters in useful length with a flow rate of drying air (dew point −30° C.) of about 120 m 3 /h flowing counter currently at a temperature of 130° C.
Thus a positive electrode was obtained, deposited directly on a current collector, said electrode taking the form of a thin composite film having a thickness of 62±2 μm, a porosity tower than 1.5%, a width of 250±1 mm and a water content lower than 600 ppm.
A scanning electron microscope (SEM) micrograph is shown in annexed FIG. 2 (1000× magnification).
This micrograph shows that the electrode film has high-quality edges and a uniform thickness.
Moreover, and in order to check the absence of degradation of the polymer used in the preparation of the electrode, measurements of viscosity in solution were carried out on the HQSEB polymer before extrusion. The steps of the operating procedure included dissolving the polymer in the presence of lithium salt in water at 1 wt % (18 h at 40° C. with gentle stirring in a water bath), filtering with “Durieux® ash-free rapid-filtration” filter paper and measuring the kinematic viscosity in a Schott® viscometer consisting of a Ubbelohde capillary tube (Ic series, calibrated K˜0.03) placed in a thermostatic bath (model Schott® CT32) at 30° C. on a base equipped with optical sensors connected to a timer (Schott® Geräte-type AVS 310) allowing the descent time of a precise specific volume of the solution through the capillary tube of known specific diameter to be measured with precision. The viscosity was derived from the mixing time using Poiseuille's law. A viscosity of 7±0.1 mm 2 /s was obtained before extrusion. The same analysis was carried out on polymer sampled from the extruded cathode film, after a first step of dissolving the cathode (18 h at 40° C. with gentle stirring in a water bath) to finally obtain a solution of 1 wt % of polymer, a second step of separating the fillers (active material and carbonaceous load) by centrifuge (20 minutes at 350 rpm) and a filtering step (with Durieux® filter paper) being carried out before the solution was introduced into the Ubbelohde tube.
A viscosity of 6.8±0.1 mm 2 /s was obtained after extrusion, thereby demonstrating that the extrusion process according to the invention does not degrade the polymer of the composition of the mixture used to manufacture the electrode.
Example 2
Preparation of a Positive Electrode According to the Process of the Invention
In this example, a positive electrode was produced with the process according to the invention, at a feed rate of 100 kg/h, using a corotating twin-screw extruder equipped with a number of weigh feeders one of which was connected to a side feeder, a liquid injection pump, a rework single-screw extruder coupled to a flat die, a unit for rolling the electrode onto a current collector and a drying tunnel.
The arrangement used is similar to that of example 1.
The positive electrode was prepared by introducing a poly(ethylene oxide)/poly(butylene oxide) copolymer in the form of granules, sold under the trade name HQSEB by Dai-Ichi Kogyo Seiyaku (DKS), into the feeder ( 2 a ), introducing high-specific-surface-area carbon particles sold under the trade name Ketjen Black EC-600 H) by AkzoNobel into the feeder ( 2 b ), and introducing LiFePO 4 particles into the feeder ( 2 c ) connected to the side feeder. The feed rates of the weigh feeders were adjusted so as to obtain, after mixing in the extruder and before drying, an extruded composite containing 16.4 wt % of polymer, 1.3 wt % of carbon particles and 65.1 wt % of LiFePO 4 . The contents of the feeders ( 2 a ), ( 2 b ) were introduced in succession into the twin-screw extruder by gravity ( 1 a and 1 b ), The contents of the feeder 2 c were introduced into the twin-screw via a side feeder. Demineralized water containing 15 to 40 wt % of LiTFSI was also introduced by means of the liquid injection pump ( 3 ) into the twin-screw ( 1 c ), in a sufficient amount to obtain, after all the ingredients had been mixed in the twin-screw of the extruder ( 1 ), an extruded composite containing 8 to 16 wt % of water. The total dry feed rate was adjusted to 100 kg/h, i.e. a feed rate of about 108 to 119 kg/h taking account of the weight of injected water. The extrusion was carried out at a temperature of 65° C. while the twin-screw was rotated at about 180 rpm. The composite resulting from the extrusion was then reworked by the rework single-screw extruder ( 4 ) at a rate of 24 rpm and at a temperature of 65° C. and delivered to the flat die ( 5 ) before the final step of rolling ( 6 ) in which the extruded mixture was rolled onto a current collector consisting of aluminum 12 μm in thickness and coated with a electrically conductive protective lacquer 2 μm in thickness on each face, the lacquer being identical to that described in example 1 above, at a rolling rate of 35 m/min. The film of extruded material applied to the current collector was then dried, so as to remove the water, by passing it through a horizontal-float drying tunnel ( 7 ) having a length of between 30 and 50 m and upper and lower nozzles blowing air at speeds of 30 to 60 m/s and applying temperatures of 60 to 180° C., depending on the position of the zones.
Thus a positive electrode was obtained, deposited directly on a current collector, said electrode taking the form of a thin composite film having a thickness of 52±2 μm (sample measured in a laboratory using a Mitutoyo® profilometer), a porosity tower than 2.5%, a width of 380±1.5 mm and a water content lower than 600 ppm.
An in-line thickness measurement that was zeroed on the current collector system in order to measure the thickness of the first cathode face post drying confirmed the average thickness to be 52 μm±2 μm. The in-line thickness measurement was carried out by a Keyence® LS 7030 travelling optical device (transverse travel in order to analyze the complete width) employing a set of LEDs.
The porosity was measured by the conventional mass/volume technique allowing the true density of the product to be derived—measurements carried out with a Micromeritics AccuPyc 1330 helium pycnometer confirmed the small porosity values. Actual density measurements performed prove the low porosity level of the final product. SEM observations of the surface and edge face (not shown) allowed these properties to be confirmed. Pores were not observed, on the surface, and voids were not seen in the samples examined.
An in-line defect detection system (Aviiva® SM2 4096-pixel, high-definition linear camera with Incore Systems® software) also made it possible, throughout production, to monitor the quality of the film (absence of foreign bodies, scratches, pores, etc.) and to control in line the width of the cathode and the collector edges. The average value 380±1.5 mm was measured by this measurement system.
The second cathode face was extruded and processed with the same parameters on the free face of the above system {current collector/cathode/first face}. A current collector coated with a positive-electrode film on each face was thus obtained, having a total thickness of 120±4 μm (including both cathode faces, the current collector and its protective layers), a porosity lower than 1.5%, a width of 380±1.5 mm and a water content lower than 500 ppm. An in-line thickness measurement that this time zeroed on the first current collector/cathode system in order to measure the specific thickness of the second cathode face post drying returned an average statistical thickness of 52 μm±2 μm.
Example 3
Preparation of a Lithium Battery
In this example a lithium battery was produced containing:
the positive electrode manufactured in example 2 above; an electrolyte consisting of a bilayer film as described in patent application FR-A-2 881 275, i.e. a film consisting of a first 10 μm-thick film in contact with the cathode and containing, by weight, 38% of polyoxyethylene (POE), 53% of PVDF/HFP, 9% of LiTFSI and a second 10 μm-thick film in contact with the lithium and containing 70% of POE, 22% of PVDF/FIFP, 17.8% of LiTFSi and 10% of MgO; a lithium film having a thickness of 70 μm, as a negative electrode; and an aluminum current collector.
Winding was used to join these elements.
The battery was made to operate in a C/2 discharge regime and a C/4 charge regime, by applying a voltage of between 3.6 V and 2.5 V to its terminals.
The voltage=f(capacity) charts obtained. (not shown) were normal and showed no process-related defects.
The lifetime measured was 1308 cycles (end-of-life corresponding to a loss of 20% of the initial capacity of the battery) which is much higher than the target set of 1000 cycles.
It therefore seems that employing the process for preparing a positive-electrode film in accordance with the invention does not cause the performance of batteries using this film to deteriorate. | 4y
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REFERENCE TO PRIOR APPLICATION
This is a continuation of application Ser. No. 568,867, filed Apr. 17, 1975, which application is a continuation-in-part of Ser. No. 196,765, filed Nov. 8, 1971 (now abandoned).
BACKGROUND OF THE INVENTION
The disposal of waste products, such as human and animal digestive waste products, as well as the waste from industries, has always been a major social and economic problem. Such waste products include human and animal digestive waste products, and in addition, liquid waste products from industries, such as pulp and paper, meat slaughtering and packaging, cotton processing, canning, dairy products, sugar refining, frozen foods and vegetable, poultry, hides, leather and wool scouring and the like. Such industries produce waste products characterized by high biochemical oxygen demand levels and a large amount of suspended solids and pathogens. A variety of processes have been employed to render all of these pathogenic waste materials harmless, and to remove them as pollution factors. A great many of these processes employ a system of bacteriological decomposition.
Bacteriological decomposition processes often require enormous storage facilities because of the time required for bacteriological action, such as 30 to 60 days. In a typical process for the treatment of raw sewage, incoming raw sewage containing pathogenic microorganisms is sent through a comminutor where large solid material in the raw sewage is reduced in size, and then the sewage pumped to an aerated grit chamber where grit is removed. Such raw sewage contains less than 1% by weight of solids; for example, less than 2,000 parts per million of solid material. After removal of the grit, the sewage is directed to large settling tanks where the material is held for a period of time to permit settlement of the solids. Oleophilic material, such as grease, is then decantered from the surface of the liquid in the settling tanks, and the supernatant liquid removed from this primary settling tank and sent to a final aeration settling tank for a secondary treatment, and then further, forwarded to a chlorine-contact tank wherein typically about 99.8%, but less than all, of the pathogenic bacteria or microorganisms are killed by chlorine contact. The resulting liquid is then discharged into waterways or further chlorinated and recycled for reuse.
Typically, the raw sewage sludge removed from the primary treatment tank comprises from about 3 to 10% solids, which sludge is removed and sent to a digestion tank wherein the solids are decomposed by the reaction with a seeded bacteria which decomposes the carbohydrate waste material, generating heat and methane gas. The methane gas generated from such digestion tank(s) is often removed and used as fuel for heating the digestion tanks for other fuel purposes. Water is removed from the digestion tank from the decomposed solids, and, thereafter, the aerated or bacteria-digested raw sludge material is then formed into a cake-like material, either by the use of sludge beds or filters to form a moist cake product. The cake product, rich in nitrogen, may then be used for landfill, fertilizer, soil conditioner, or otherwise used or disposed of. Such a treatment process is commonly employed throughout the country to dispose of sewage products.
The decomposed solids or sewage sludge leaving the digestion tank and the supernatant liquid leaving the chlorine-contact tank often fall far short of being pathologically pure, or meeting the minimum standards required for effective pollution control. Numerous chemical methods are available for the further sterilization of these organic waste materials; however, cost and residual toxicity have rendered many of such techniques economically inadvisable.
There are a number of processes for the preparation of nitrogenous fertilizer compositions employing urea-formaldehyde condensates, such as, for example, those techniques described in U.S. Pat. Nos. 2,592,809; 2,644,806; 2,766,283; 2,830,036; 3,076,700; and 3,227,543. In addition, U.S. Pat. Nos. 3,073,693 and 3,226,318 are directed to the employment of polymerizable monomers with sewage solids to produce a synthetic nitrogen-containing fertilizer by-product.
For example, U.S. Pat. No. 3,073,693 prepares a nitrogenous fertilizer material by reacting sewage sludge, peat moss and a urea-formaldehyde solution, and immediately thereafter, condensing the urea-formaldehyde with the use of a strong acid to form a resin product. The reactants are admixed for between 1/2 and 2 minutes in an acid solution, whereby polymerization and condensation of the urea-formaldehyde is effected and the resulting mixture then admixed with an aqueous solution of ammonia to form the ammonium salt of the strong mineral acid. The sewage sludge employed is the type of sludge produced by the activation or digestant method; that is, an activated sterile sewage sludge, which has been removed from the digestion tank and dewatered.
U.S. Pat. No. 3,226,318 is directed to the consolidation by condensation of an aqueous waste sludge wherein a phenol-formaldehyde solution is added to the sludge, and promply thereafter, condensation is accomplished by the further addition of formaldehyde as a curing agent. This sewage treatment process is directed to a sewage sludge containing digested sewage solids and about 60% water in which a phenol-formaldehyde solution under acid conditions is condensed to provide a consolidated sludge product.
SUMMARY OF THE INVENTION
My invention comprises a new and improved process for the treatment of raw sewage, waste activated diluted sewage sludge, sewage sludge, and other solid organic-containing aqueous waste solutions, such as industrial organic waste material, to provide a solid waste. In particular, my invention concerns the process for treating organic waste material, such as raw sewage and sewage sludge, contaminated with a pathogenic microorganism and the sterile waste product produced. The process comprises reacting and sterilizing such solid waste material, and, thereafter, forming the solid waste material into a sterile, easily recoverable and usable waste product.
More particularly, my invention relates to a process for the treatment of raw sewage and waste activated or digested sewage sludge which contains pathogenic microorganisms. The process comprises: prereacting the waste material in the solution under alkaline pH conditions with a water-soluble, monomeric, condensable methylol compound to sterilize pathogenic organisms in the waste material; and, thereafter, condensing the monomeric methylol compound by establishing an acid pH condition in the solution to form a waste product which comprises a solid condensate having methylene bridges and solid sterilized organic waste material.
Even more particularly, my invention concerns the process for the treatment of liquid undecomposed raw sewage-containing organic solid waste material and contaminated with pathological microorganisms, which process comprises: prereacting and sterilizing the solution by adding thereto a urea-formaldehyde solution under alkaline pH conditions, which solution contains a water-soluble N-methylol monomeric material, and maintaining such materials in contact with the organic waste material for a sufficient period of time to sterilize said material; and, thereafter, condensing the urea-formaldehyde monomer by establishing an acidic pH condition to provide a solid pathologically sterile organic waste product.
In the preferred embodiment of my invention, nitrogen-containing monomeric compounds, such as mono and dimethylol urea (that is, the water-soluble reaction products of urea and formaldehyde) are prereacted under alkaline pH conditions with the organic waste material suspended in an aqueous solution. Raw sewage is typically acidic in nature and the solid material therein is hydrophilic. After prereacting and condensing, the solid organic waste product produced by my invention is hydrophobic in nature. I have found that my process permits the organic waste product to be easily dewatered and recovered in high yields from the aqueous solution. In addition, the use of urea-formaldehyde condensate provides for an inexpensive raw material and a linear-type, low molecular weight, short-chain polymer so that the resulting solid product of the process is easily broken up by a metabolic process when employed as an animal feed material, or by soil bacteria when employed as a fertilizer. The resulting waste product comprises a reacted admixture of a polyurea condensate and a pathogenically stable organic waste material, thereby providing a superior product for use as a metabolic process or for soil digestion.
In general, the monomeric methylol compounds in the solution are employed in an amount ranging from about 10 to 100% by weight of the organic waste material; for example, from about 50 to 80% of the organic waste material. However, it should be recognized that the amounts to be used may vary, depending upon the sterilizing or reacting effect desired and the amount of the condensate resin required to provide the proper ultimate end use of the product.
In my process, it is essential that effective sterilization of the pathologically containing organic waste material be achieved by contacting and reacting the waste material under alkaline pH conditions. Such contact and reaction should be with a methylol monomeric compound capable of further polymerization and/or condensation, and, in the preferred embodiment, for a sufficient period of time to effect the desired sterilization. Prior processes in which urea-formaldehyde or phenol-formaldehyde solutions have been incorporated into a sewage material have typically been for activated or digested sewage material and under acidic conditions to promote the rapid and effective condensation of the polymer to solid waste material. The waste material on which such techniques were employed comprised the digested or activated sewage sludge, rather than the raw sewage, or the unactivated sewage sludge from the settling tank.
My process is particularly advantageous in that effective sterilization and reaction of the waste material with a methylol monomer, such as an N-methylol monomer, converts the waste material into a solid product of a hydrophobic nature. The solid product produced by my process exhibits superior dewatering properties and produced by my process exhibits superior dewatering properties and permits recovery of the product at high yields. The condensation reaction with methylol-urea provides a nitrogen-containing waste by-product which may be employed as a slow nitrogen release fertilizer material. I have found that only very small quantities of a methylol-containing compound are sufficient to destroy the majority of the pathogens; for example, in generally less than thirty minutes. Further, in my process, any low solids waste material, such as sewage, may be treated; although in a preferred embodiment, sewage sludge prior to digesting is treated, thereby permitting the omission of the digesting step which requires large storage tanks, high capital investment and long time periods. Such treatment significantly reduces sewage odor in the process. If desired, my process may be effectively used on all types of pathogenic-containing waste materials, even digested sewage sludge, to effect even greater sterilization prior to consolidation and recovery of the solid product.
The solid pathogenically sterile organic waste product from my process, where such sewage material is not subjected to a bacterial decomposition or digesting step, is characterized by superior properties as a fertilizing or digestive material in that any breakdown of the long-chain carbohydrates in the material occurs when applied to the soil as a fertilizer or feed to animals. Thus, a novel, unique and improved fertilizer composition is prepared, which composition comprises an undigested pathogenically sterile solid sewage material containing a condensed or polymerized material having methylene bridges, particularly a condensed urea-formaldehyde, low molecular weight dimer or trimer condensate, which composition is particularly useful as a fertilizer in high-solid form, moist cake, or dry powder. Where desired, after treatment and recovery, the product may be concentrated and partially or fully dried and used in moist cake, powdered, granular, pellet or other form. The solid waste product of the process may also be directly employed as a fertilizer by spraying or otherwise applying the aqueous solution containing the product to a field or as an animal feed product. Other additives may be incorporated prior to condensation or thereafter, as desired, such as filler materials, additives to enhance color or taste, additives to aid in processing, such as flocculents, additives to aid in adjusting the ultimate use as a fertilizer, such as urea, other natural or synthetic fertilizers or compounds used in fertilizers, such as nitrogen-containing or phosphate compounds.
As used herein, the term "organic waste material" is intended to include raw sewage, solid sewage sludge recovered from municipal disposable units, as well as solid carbohydrate and proteinaceous material recovered from industrial waste liquors from the treatment of leather, wool, food, fish, meat products, dairy products, pharmaceutical waste products, such as antibiotics, and the waste products of bio-organic materials and the like, which organic waste materials typically contain pathogenic microorganisms. In a preferred embodiment of my invention, such organic waste materials would include raw sewage and waste activated sewage sludge; that is, prior to digestive techniques. However, where desired, my process may also be usefully employed in reacting varied or digested sewage sludge or other materials which have been treated to remove substantially all or a portion of the pathogenic microorganisms therein.
I have found that effective sterilization of organic waste materials can be accomplished in one embodiment by incorporating and reacting a solution of urea and formaldehyde under alkaline pH conditions into and with said organic waste material. The urea and formaldehyde typically have a urea-formaldehyde mole ratio of greater than 1:1; for example, 1:1 to 2:1, but preferably in a range of 1.3:1 to 1.8:1, whereby the urea is in excess of the formaldehyde to be employed. Under such conditions, urea-formaldehyde reacts to form the mono or dimethylol urea or mixtures thereof. The water-soluble N-methylol-containing monomer, when held in contact and reacted under suitable time and temperature conditions with the waste material, effectively prereacts with and sterilizes the waste material. An excess of urea is preferred, but not necessary if a cross-linked condensate is acceptable in the resulting waste product. The use of excess urea provides for a linear, rather than cross-linked, polymer.
I have found that surprising results in dewatering properties and solids recovery are obtained, as well as economic benefits, if the urea and formaldehyde are prereacted to form the methylol compound under alkaline conditions, and the methylol compound is added to the aqueous solution containing the organic waste material, rather than the separate use or addition of the urea and formaldehyde and an insitu reaction. Further, I have discovered that prereacting the urea and formaldehyde just prior to use, rather than the employment of an aged urea-formaldehyde solution, is desirable. The urea-formaldehyde is reacted under alkaline conditions until a proper degree of methylolization is achieved. Urea in either crystalline, prilled, solution or other form is added to the formaldehyde in the presence of water and a suitable buffering agent to maintain an alkaline pH of, for example, between about 7.0 to about 9.0, thereby forming the water-soluble mono and/or dimethylol-urea monomer.
The concentration of urea and formaldehyde will depend largely upon the physical conditions of the organic waste material being used. In general, the most effective method is to dissolve either crystalline or prilled urea in a 37% aqueous solution of formaldehyde which has been buffered, then diluting this preparation accordingly to meet the requirements of the organic waste material to be sterilized. The waste material to be reacted with the methylol compounds should be in a fluid or semifluid sludge state in order to allow permeation of the methylol solution into reactive contact with the particulate solid material.
My invention will be described in particular concerning the use of urea-formaldehyde concentrates; however, it is recognized that other aldehydic compounds may be employed in place of the formaldehyde solution, such as the use of paraformaldehyde, crotenaldehyde, acetaldehyde, propionaldehyde, furfural, and the like in order to prepare a methylol monomer. Urea-formaldehyde is the preferred alkaline monomeric solution, since such material is a low-cost nitrogen-containing material which provides for N-methylol groupings, and, further, the nitrogen of the urea is effective in providing a slow-nitrogen-releasing fertilizing composition.
In determining the particular concentration of the methylol monomer to be employed, consideration should be given to any side reactions which might react with the methylol compound in the organic waste material, such as ammonia, sodium bisulfide and the like. The concentration to be employed in my process may vary, depending upon the ultimate end use of the solid waste product. For example, if the product is to be employed merely as a sanitary landfill or as fuel where there is little or no recovery of cost of treatment, only minimal concentrations sufficient to obtain the desired sterile levels; e.g., to prevent odors or to improve the dewatering properties, should be employed. However, if the product is to be employed as a fertilizer or as an animal feed supplement, then larger concentrations are often advantageous, since the cost can be recovered and the high nitrogen content resulting from the treatment lowers the transportation cost of the product to its point of distribution. It is theoretically possible to reach a concentration which results in a waste product with a nitrogen content of about 38% by weight. However, the concentration of the organic waste material would be so low as to be relatively ineffective as a useful product.
It is essential that the reaction time and concentration of the methylol-containing monomeric solution with the organic waste material under alkaline pH conditions be sufficient to insure the desired reaction and/or sterilization. The contact time is dependent largely upon the temperature of the resulting organic waste slurry and the presence of other bactericidal catalytic agents, such as soaps, synthetic detergents, alcohol, and the like which may have an affect on the bactericidal and reaction activity of the methylol monomeric materials. Typically, complete sterilization of an organic waste material at a temperature of 5° to 10° C requires a contact time of up to 3 to 4 hours, while, at a temperature of 20° C, only about 5 to 30 minutes is required. At temperatures of 60° C and more, the reaction and sterilization appear to take place very rapidly in a matter of 1 to 10 seconds with methylol-urea. A preferred contact and reaction time employing a urea-formaldehyde-methylol monomeric solution is between about 5 minutes and 2 hours at temperatures of between about 20° C and 60° C.
In the preferred embodiment, a methylol-urea monomer solution is incorporated into an organic solid waste product sludge containing a pathogenic microorganism under alkaline pH conditions. Furthermore, the solution may be incorporated directly into raw sewage; that is, undigested sewage; e.g., having about 5 to 50% by weight of solid material. The methylol monomers employed should be water-soluble monomers or mixtures of water-soluble monomers subject to the further condensation and/or polymerization.
After reaction and sterilization of the organic waste material, the methylol compound is subject to a condensation or polymerization reaction, which converts the highly toxic methylol groups of the mono or dimethylol-urea to nontoxic methylene bridges in the condensate polymer. One method of accomplishing condensation of urea-formaldehyde solution wherein urea is in the excess is to reduce the pH of the alkaline reaction solution to the acid side; for example, to between 2.0 and 5.0, by the addition of a suitable organic or inorganic acid. The time for condensation is effected by the temperature and pH conditions. For example, when employing a urea-formaldehyde solution, a reduction of the pH to about 5.0 and the employment of a temperature of about 15° C, complete methyleneization or condensation often requires about 2 days. However, when the temperature is increased to 80° C, the condensation reaction is often completed in as little as 2 to 10 minutes. I prefer to employ a pH of approximately 3.0 to 4.5 at a temperature of between 60° and 80° C which effects condensation in a period of time between 1 and 20 minutes, such as, for example, 1 to 5 minutes.
Where desired, other monomers or polymerizable monomers or polymers may be incorporated into the organic waste material and condensed or interpolymerized with the methylol compounds. For example, the urea-formaldehyde solution wherein the formaldehyde ratio is from 1 to 5 moles per mole of urea may be employed to effect reaction and sterilization of the organic waste material, and then subsequently urea added separately so that the urea is in excess, and then the resulting urea-formaldehyde solution condensed by reducing the pH by the addition of an acid. Any acid or acid salt may be employed to reduce the pH; for example and preferred are inorganic acids, such as sulfuric acid, sulfonic acid, hydrochloric acid and phosphoric acid.
Depending upon the ultimate use of the waste product, the pathologically sterile treated waste product from my process may be disposed of as a pathologically pure organic waste material. However, if the waste product is to be recycled into the food chain as a fertilizer or animal feed or animal feed supplement, then typically it should be further treated, such as by neutralization, or otherwise properly prepared for acceptance in the marketplace. Where the product is to be useful as a fertilizer and animal feed supplement, the product should contain a low molecular weight linear condensate therein; that is, where the molecular weight, for example, ranges from 120 to 250, such as below 800, or where the urea-formaldehyde condensate is primarily methylene diurea or trimethylene tetraurea, or the like. For such use, the condensate should be generally straight-chain, branch or graft-type condensates which may be easily broken down by the nitrogen-acting bacteria of the soil, or by the metabolic process in the digestive tract of the animal. The resulting condensate or polymer should not be a highly cross-linked complex resin, but rather a low molecular weight dimer, trimer and tetramer.
A neutralization step may be employed in order to stabilize the methylene urea-formaldehyde condensate which might otherwise tend to form highly cross-linked condensates, rather than the straight-chain, branch or graft-type condensates which are sought in my process. The neutralization step may be accomplished by the addition of a suitable organic or inorganic base to the waste product in the solution. For the purposes of economy and availability, I prefer the employment of hydrated lime, ammonia, ammonium salts of calcium carbonate as the neutralizing agent. After neutralization or where the product is not to be neutralized, the waste product may be prepared in a suitably accepted dry or granular form by subjecting the material to a drying step, such as by spray-drying or the like, at which point the material is ready for packaging and distribution or disposal.
The resulting waste product or my process comprises the condensed methylol polymer preferably in low molecular weight linear form, and the reacted sterilized organic waste material which, by the reaction and sterilization under alkaline conditions, is converted from a hydrophilic state to a hydrophobic state. The waste product by such reaction and sterilization is characterized by superior and improved properties of dewatering or filterability so that a high solids content is obtained on filtering or other recovery steps or processes. The suspended waste product may be directly used in slurry form, such as by spraying as a fertilizer onto crops or fields, or directly disposed of as refuse.
In the preferred embodiment, the hydrophobic suspended particles of the sterilized waste product are recovered from the aqueous solution, such as through the employment of filters or other recovery means like centrifuging, gravity filtering, etc. The improved dewatering properties of the waste product permit high solids recovery of the product from the slurry solution.
For the purposes of illustration only, my invention will be described through the employment of a urea-formaldehyde solution with organic waste material.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Example 1
A sample of raw undecomposed; i.e., unactivated, sewage sludge was obtained from the sewage treatment plant located at the City of Woonsocket, R.I. Analysis of the material showed the following:
______________________________________Total solids 6%Total Nitrogen (solids) 2%Bacteriological ReportCulture report indicates the pressureofStreptococcus (alpha) Gr. 0Escherichia coliEnterobacter GroupB. SablilisSmear Report:Gram neg. - gram pos. rods gram positive diplorocci______________________________________
1,000 grams of this raw sewage sludge was treated with 60 grams of a urea-formaldehyde solution prepared in the following manner:
50 grams of commercially available 37% formaldehyde was neutralized with triethanolamine to a pH of 8.0. To this was added 50 grams of a commercially available prilled urea containing 46% nitrogen. The negative heat of solution caused a drop in temperature to 5° C. The solution was gently heated to 30° C at which point the urea was in solution with the formaldehyde. After 10 minutes the temperature of this solution rose to 60° C at which point it was added to the 1,000 grams of sewage sludge.
The resulting mixture (a heavy viscous mass) was kept under constant agitation at a temperature of 20° to 25° C. The temperature was raised to 60° C and maintained at this level for a period of about 30 minutes at which time sufficient dilute hydrochloric acid was added to reduce the pH to 3.0.
The resulting slurry began to thicken quite rapidly at this point and was transferred to a mechanical kneader for further handling. After a period of about 5 minutes, the methyleneization was considered complete because of an absence of any formaldehyde odor.
The compound was further tested by Deniges method and a modified Schiff's reagent and no formaldehyde was found to be present.
At this point a sufficient quantity of calcium carbonate was added to neutralize the mixture and to raise the pH to 6.5 to 7.0.
Without further treatment, the product was subjected to the same analysis as the raw sewage sludge with the following results:
______________________________________Total solids 10%Total Nitrogen (solids) 21%Bacteriological ReportCulture -- no growthSmear -- no bacteria______________________________________
A portion of the above sample was passed through a 10-mesh sieve. The resulting granular product was then subjected to drying at 100° C for a period of 30 minutes. The sample was then analyzed for its agronomic usefullness as a high analysis organic nitrogen fertilizer.
The qualities sought for in an organic material as a fertilizer are:
NITROGEN PLANT FOOD CONTENT
Most nitrogenous organic fertilizers contain about 6% nitrogen, while the average mineral or inorganic fertilizer contains between 10 and 20 percent of this essential plant food element. From the economic standpoint of transportation and application of fertilizer this means that the currently available sources of organic fertilizers are between 100 and 300 percent more expensive than their mineral counterparts. Therefore, an organic compound with competitive nitrogen contents would be highly desirous.
II. INSOLUBLE NITROGEN CONTENT
Organic forms of nitrogen have always commanded a premium price in the fertilizer market because of the relative insolubility of their plant food nitrogen. This insolubility leads to longer lasting nitrogen and considerably less leaching of the nitrogen. From the standpoint of ecology, insoluble forms of nitrogen prevent leaching or washing into surrounding water stratums, rivers, streams, etc.. Insoluble forms of nitrogen usually depend on their release of nitrogen plant food through natural bacterial decomposition in the soil. This results in a more gradual release of the nitrogen plant food, as well as a stimulation of the soil micro flora and fauma.
III. QUALITY OF INSOLUBLE NITROGEN
Many forms of insoluble nitrogen are so tightly bound in complex molecules that for all practical purposes they are available for bacterial breakdown and therefore cannot enter the food chain cycle. Recent work has indicated that the availability of insoluble nitrogen can be obtained by determining the percentage of water insoluble nitrogen which dissolves when a sample of 0.25 grams of the product is heated to 100° C for 30 minutes in 250 milliliters of neutralized water. The percentage figure thus obtained is called the "Activity Index". It is generally accepted that a product with an "Activity Index" of greater than 40 will yield the bulk of its nitrogen within a six-months incubation period in the soil. The analysis of the product obtained from this example was:
______________________________________Total Nitrogen 21%Insoluble Nitrogen 15%Activity Index 55______________________________________
EXAMPLE 2
1,000 grams of a fish meal intended for use as a poultry feed supplement, and containing about 9% nitrogen, and found to be contaminated with pathogenic salmonella was treated with 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 grams respectively of a urea-formaldehyde solution prepared in the same manner as indicated in Example 1.
The urea-formaldehyde solution was added to the dry fish meal as a fine spray, while the meal was being rotated in a cylinder similar in appearance to a small sized cement mixer.
The temperatures of the resulting mixtures were raised to 30° C. The products were held at this temperature for a period of about 2 minutes at which point the methyleneization step was introduced by spraying a dilute solution of hydrochloric acid until a pH of 3.0 was recorded. The products were held under this condition until methyleneization was complete as indicated by the tests performed in Example 1. A sufficient amount of calcium carbonate was added to the mixtures to insure a neutral pH.
Without further treatment, the samples were subjected to bacteriological and chemical analysis with the following results:
______________________________________ Salmonella %Protein______________________________________Check 0 treatment + 56.25 10 gr. treatment - 57.09 20 gr. treatment - 57.93 30 gr. treatment - 58.78 40 gr. treatment - 59.62 50 gr. treatment - 60.46 60 gr. treatment - 61.30 70 gr. treatment - 62.14 80 gr. treatment - 62.98 90 gr. treatment - 63.82 100 gr. treatment - 64.66______________________________________
EXAMPLE 3
A sample of tannery waste sludge containing about 10% solids and composed of such materials as fleshings, hair, entrails, and general nide scrappings (in addition to these organic constituents there was a sufficient amount of sulfide contamination to cause considerable odor problems) was subjected to our treatment by adding 166 grs. of urea-formaldehyde solution, prepared in accordance with Example 1, to 1,000 grams of the tannery waste sludge.
In the same manner as previously disclosed, the resulting slurry was maintained at a pH of 8.0 and a temperature of 30° C for a period of 30 minutes.
The pH was then reduced to 3.0 by the addition of a dilute solution of sulfuric acid and the temperature was raised to 60° C. Sufficient agitation was supplied to maintain a state of equilibrium between solid and liquid phases. Methyleneization was allowed to continue to a point where no free formaldehyde was detected by Deniges method described in Example 1.
The resulting mixture was then neutralized with a sufficient quantity of a dilute sodium hydroxide solution (1% NaOH) to raise the pH level to 7.5, dried by subjecting the mixture to a continuous stream of hot air (110° C) while tumbling in a rotating cylinder for a time sufficient to reduce the moisture content to about 5% and then ground to a uniform particle size (-10-20 mesh).
This product was then analyzed for its agronomic properties and found to contain the following:
______________________________________Total Nitrogen 24.2%Insoluble Nitrogen 19.0%Activity Index 52.0______________________________________
The process of my present invention has many advantages in the treatment of pathogenic waste materials in so far as the investment of capital equipment is minimal. For example, a small jacketed reaction vessel may be used to prepare the methylol solution. This solution may be added batch-wise or continuously to the organic waste material. The methyleneization step of our process can be carried out by an in-line injection of the mineral or organic acid. Neutralization can also be effected in the same manner. Both steps can be greatly accelerated by elevating the temperature of the organic waste material to be treated. In the case of a sludge-like material such as the raw sewage sludge and tannery waste used in our experiments, the material can be passed through a heat exchange. The urea-formaldehyde solution can also be handled in the same manner. In the case of dry materials, such as the fish meal used in our second experiment, they can be passed through a rotating cylinder concurrently or countercurrently to a stream of heated air in order to raise the temperature to around 60° C.
EXAMPLE 4
It has been found that the preparation of a preformed urea-methylol solution and prereaction with an organic waste material provides unexpected and increased efficiency in the dewatering of the waste product from the solution. The addition and prereaction of the methylol solution is superior to the addition separately of urea or formaldehyde and in situ condensation.
Two buckets of sewage sludge were collected from the Merrimack, New Hampshire waste treatment plant, In each run, 1,000 ml of sludge were used. Adjustment of pH in the process was done with 12% KOH for the alkaline step, and 30% H 3 PO 4 for the acid step. Both samples of sludge contained 3.7-4.0% solids as determined by overnight drying at 100° C. The samples were treated with urea, formaldehyde and urea-formaldehyde methylol solutions as set forth in Table I.
TABLE I______________________________________ M1 Reactant- Grams UreaSample Sludge Reactant to-Sludge GramsNo. Taken Added Solids ratio Formaldehyde______________________________________1 1,000 U/F 1/1 20/202 1,000 U/F 1.5/1 30/303 500 Blank -- --4 1,000 U-F 1/1 20/205 1,000 F-U 1/1 20/206 1,000 F-U 1.5/1 30/307 1,000 U-F 1.5/1 30/308 1,000 U/F 1.5/1 30/30______________________________________ *U/F = Normal makeup of urea-formaldehyde solution (methylol solution) U-F = Urea added for 10 minutes followed by formaldehyde for 10 minutes F-U = Formaldehyde added first, followed by urea - same time.
All samples were treated at 60°-65° C at pH 7.2 to 7.5 alkaline conditions, and then subsequently converted to an acid condition pH of 3.0 to 3.5. The samples were placed in one quart plastic containers and filtered.
Filtrations were carried out, of 200 grams of each sample, through two pieces of 12.5 cm Whatman #1 filter paper using a vacuum pump set at 15 inches water vacuum. The amount of filtrate obtained in 10 minutes was determined along with the grams and percent solids of the filter cake.
Sedimentation tests were attempted in 40 ml centrifuge tubes; however, because of the heavy amount of flocculation, sedimentation rates had to be carried out on diluted samples (35 gram sample -- 15 grams water) and thoroughly shaken before sedimentation.
Table II shows the results of the filtration experiment. The processed sludge samples, regardless of the method, filtered well, while the blank sample filtered only slightly in the 10-minute period. In comparing the (F-U) versus the (U-F) method, the (F-U) gave better filtrations. The U/F preparation gave the highest solids filter cake at both reactant levels of 1/1 and 1.5/1.
TABLE II______________________________________ React/ Sludge GMS** % SolidsSample Reactant Ratio ML* Filter FilterNo. Added (GMS) Filtrate Cake Cake______________________________________1 U/F 1/1 157 40.8 21.22 U/F 1.5/1 -- -- --3 Blank -- 35 Too wet to determine4 U/F 1/1 134 58.9 14.75 F-U 1/1 151 45.9 18.56 F-U 1.5/1 151 47.4 23.77 U-F 1.5/1 145 52.0 19.48 U/F 1.5/1 151 47.8 25.5______________________________________ *After 10 minutes filtration at 15" vacuum **Grams wet filter cake after 10 minutes
The sedimentation tests showed only that all the processed samples, regardless of the method, settled out in a uniform rate; that is, no differences in sedimentation rate were seen. After one hour in the centrifuge tubes, samples 1, 6, 7 and 8 showed 6 ml of clearing. The blank showed only 1 ml, indicating that processing did have an affect on the sedimentation.
The use of methylol solution (sample #1) in comparison to the addition of formaldehyde first (sample #5) provided for an additional 2.7% solids collection or an increased dewatering efficiency of 14.5%. Sample #8 compared with sample #7 with urea added first provided for an additional 6.1% solids on increase in efficiency of 31.4%.
My process has also the advantage that it can reduce organic waste materials to pathologically pure materials which can be recycled to the ecology in a matter of minutes, where as concurrently available methods require 30 to 60 days to achieve a similar result.
This process has further advantages in that its products can be recycled to the ecology at a level substantially higher than similarly biologically treated products. Biologically treated products are not pathologically pure and therefore cannot be considered for use as an animal or human feed supplement. The products of my invention are pathologically pure and could be considered for these purposes. | 4y
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TECHNICAL FIELD
[0001] This invention relates to the manufacture of photovoltaic electrodes, and in particular to the manufacture of dye-sensitized solar cells.
BACKGROUND ART
[0002] Dye-sensitized solar cells (DSSCs) show considerable potential as a relatively low cost alternative to silicon based solar cells. These cells were developed by Gratzel and co-workers in 1991 [B. O'Regan, M. Gratzel, Nature, 353 (1991) 737-740] and there is currently a considerable focus on enhancing their light conversion efficiency and stability.
[0003] The principal components of a DSSC electrode are a conducting substrate, which is usually a transparent conductive oxide coated on glass, a highly porous layer of semiconductor material, and a photosensitive dye absorbed into and coating the porous semiconductor.
[0004] In the case of conventional DSSCs, dye sensitization involves solely the semiconductor anode made of n-type TiO 2 nanoparticles. The counter electrode is generally a metallic cathode with no photoelectrochemical activity. To date the highest conversion efficiency obtained of 11% [M. K. Nazeeruddin, F. De Angelis, S. Fantacci, A. Selloni, G. Viscardi, P. Liska, S. Ito, B. Takeru, M. Gratzel, Journal of the American Chemical Society, 127 (2005) 16835-16847], is less than the best silicon based thin-film cells.
[0005] A method of further enhancing the light conversion efficiency as suggested by He et al. [J. He, H. Lindstrom, A. Hagfeldt, S.-E. Lindquist, Solar Energy Materials and Solar Cells, 62 (2000) 265-273] is to substitute the cathode with a dye-sensitized photoactivep-type metal oxide. This tandem dye-sensitized solar cell design utilizes more of the solar spectrum. The efficiency, however of p-type metal oxides is still very low, which limits their effectiveness in tandem DSSCs. Amongst the potential reasons highlighted for the poor conversion efficiency of the cathode within tandem DSSC, the more critical are the inefficient light absorption capability, poor charge injection efficiency and charge transport rate, along with inner resistance.
[0006] The most widely used n-type electrode material is nanostructured titanium dioxide. For p-type electrodes, perhaps the most promising technology employs nickel oxide (NiOx) coatings, which has a considerable potential for use as a cathode in tandem cells. This is due to their p-type nature, excellent chemical stability, in addition to well defined optical and electrical properties. Moreover, NiOx is considered as a model semiconductor substrate due to its wide band-gap energy range from 3.6 to 4.0 eV depending on the amount of Ni(III) sites.
[0007] NiOx films have been fabricated by various techniques which include spin coating, dipping, electrochemical deposition, magnetron sputtering and sol-gel. With the exception of the sputtering and electrochemical techniques, the other methods require a sintering step in order to obtain dense coatings. Thermal sintering also performs the function of removing the binder in the case of sol gel deposited coatings. Typically sintering conditions of 300-450° C. for 30 to 60 minutes are reported.
[0008] A disadvantage with thermal sintering is the processing time. When one adds the heat-up and cool-down times, it can take approximately 4 hours to process a substrate.
[0009] Further disadvantages with conventional thermal sintering include the photovoltaic performance of photocathodes produced according to this method and the probably related physical shortcomings of such photocathodes, such as the adhesion between the substrate and the nanoparticular NiOx layer, the post-sintering average particle size, the pore characteristics, and the dye absorption.
[0010] The present invention aims to address at least some of these shortcomings and to provide improvements in the manufacture of photovoltaic electrodes.
DISCLOSURE OF THE INVENTION
[0011] There is provided a method of manufacturing a photovoltaic electrode, comprising the steps of:
[0012] (a) depositing on a substrate a dispersion comprising powdered semiconductor particles in a dispersion medium;
[0013] (b) removing the majority of the dispersion medium to leave the powdered semiconductor particles in a deposition layer on the substrate;
[0014] (c) creating a plasma using microwave energy excitation;
[0015] (d) exposing the deposition layer to said microwave-excited plasma for a sufficient time to sinter the nanoparticles thereby adhering them to the substrate; and
[0016] (e) absorbing a dye into said sintered deposition layer.
[0017] It has been found that one obtains a significantly better electrode using this method when compared to thermal sintering. Improvements have been found in the physical characteristics of the nanoparticle layer, its adhesion and electrical connectivity with the substrate, and the degree of dye absorption. In particular, it is found that the electrodes produced by this method have a surface exhibiting high porosity without sacrificing the mechanical stability of the resulting coatings. This surface morphology ensures higher light absorption by the monolayer of adsorbed dye, while keeping an intimate contact between the particulate material and the dye molecules. This in turn reduces the inner resistance and hence improves the charge injection efficiency.
[0018] It is hypothesized that the advantages of the invention can be attributed to a number of factors including the rapidity of heating and the bulk homogeneity of heating due to the materials interacting with “cold” microwaves coupled through a plasma instead of radiant heat in a conventional furnace. This avoids the outer surface “cooking”, i.e. a heat-affected outer zone which can hinder dye absorption, and it increases the adhesion between sintered particles and the underlying substrate relative to conventionally sintered electrodes. Details of the results will be given below.
[0019] The net result is that electrical properties of the photovoltaic electrodes prepared according to this method are significantly improved (i.e. in some instances ten-fold or more) relative to the equivalent thermal sintered electrodes.
[0020] Preferably, step (a) of depositing a deposition layer comprises depositing a layer of said powdered semiconductor particles in a dispersion medium, and removing a majority of said dispersion medium to leave the particles weakly bound to the substrate in a deposition layer.
[0021] Preferably, said deposition step is selected from spraying, spin coating and sol gel deposition.
[0022] In a preferred embodiment, the dispersion medium is heated before, during or after the deposition step to evaporate the dispersion medium. Preferably, this is done by heating the substrate.
[0023] Evaporation may also be achieved without heating by choosing a suitable dispersion medium which evaporates at ambient temperatures.
[0024] The method involves removal of the majority of the dispersion medium. More preferable, substantially all of the dispersion medium is removed, so that the deposition layer is a substantially dry layer on the substrate.
[0025] Preferably, said powdered semiconductor particles have a maximum particle size of 20 microns.
[0026] More preferably, said powdered semiconductor particles have a maximum particle size of 500 nm.
[0027] More preferably, said powdered semiconductor particles are nanoparticles with a maximum particle size of 100 nm.
[0028] Preferably, said powdered semiconductor particles are metal oxide particles.
[0029] The invention has particular application in metal oxide particles such as nickel oxide and titanium dioxide. A further application of this technology is the fabrication of CIGS (copper indium gallium selenide) solar cells if the correct ratio of the different powders is homogeneously mixed.
[0030] Particularly advantageous results are found using nickel oxide nanoparticles, and with Erythrosin B dye (2′,4′,5′,7′-tetraiodofluorescein, disodium salt).
[0031] Preferably, in step (c), the deposition layer is exposed to said microwave plasma for between 2 and 20 minutes, more preferably between 4 and 15 minutes.
[0032] Preferably, the method further comprises the step of depositing on the substrate an adhesion enhancing agent to enhance adhesion between the semiconductor particles and the substrate.
[0033] The adhesion enhancing agent is preferably a metal compound which is reactive in the presence of water vapour to form a metal oxide.
[0034] Preferably said semiconductor particles comprise the same metal oxide as is formed by the reaction of said metal compound with water vapour.
[0035] Preferably, the metal oxide is selected from nickel oxide, titanium dioxide, tin oxide, indium tin oxide and zinc oxide.
[0036] Preferably, the metal compound is a metal alkoxide or metal halide of the same metal as is present in said metal oxide with the proviso that the metal alkoxide or metal halide is reactive in the presence of water vapour to form said metal oxide.
[0037] Where the metal oxide is titanium dioxide, the compound is preferably selected from the group of titanium tetrachloride, titanium alkoxides (including in particular titanium isopropoxide and titanium butoxide) and precursors thereof
[0038] Preferably, the adhesion enhancing agent is dispersed in an organic carrier which is substantially free of water. Particularly suitable carriers include isopropanol and tertbutanol.
[0039] When the solvent or carrier evaporates, the metal compound reacts with water vapour in the air to form an amorphous layer of metal oxide.
[0040] The step of depositing an adhesion enhancing agent preferably occurs prior to step (a) of depositing on the substrate a dispersion comprising powdered semiconductor particles in a dispersion medium. In this way, the dispersion of powdered semiconductor particles is deposited on an intermediate layer of the adhesion enhancing agent.
[0041] Alternatively, the adhesion enhancing agent is co-deposited with the semiconductor nanoparticles in the same dispersion medium, such that this step occurs as part of the deposition step (a).
[0042] In a further alternative, the adhesion enhancing agent is deposited on the substrate in a first layer together with the semiconductor nanoparticles, following which a layer of semiconductor nanoparticles is deposited without adhesion enhancing agent. Optionally, a sandwich structure of layers can be created by repeating one or more of these depositions (e.g. a three-layer sandwich, or a multi-layer repeating sandwich structure of layers with and without the adhesion enhancing agent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] The invention will now be further illustrated by the following descriptions of embodiments thereof, given by way of example only with reference to the accompanying drawings, in which:
[0044] FIG. 1 is a schematic illustration of an apparatus used to manufacture a photovoltaic electrode;
[0045] FIG. 2 shows the XRD spectra of various samples of microwave plasma sintered NiOx coatings, sintered for between 1 and 10 minutes from which crystallite size information was calculated using the Scherrer equation;
[0046] FIG. 3 shows the comparative XRD spectra of NiOx coatings sintered for 5 minutes using a furnace and using the microwave plasma technique, from which crystallite size information was calculated using the Scherrer equation;
[0047] FIG. 4 is a plot of the UV-vis absorbance spectroscopy of the microwave plasma sintered samples from FIG. 2 (treated for between 1 and 10 minutes), after having been dye sensitized with Erythrosin B;
[0048] FIG. 5 is a comparative plot of the UV-vis absorbance spectroscopy for dye-sensitized NiOx coatings sintered for 5 minutes using a furnace and using the microwave plasma technique;
[0049] FIG. 6 shows the current density vs. applied potential curves for 5 minute RDS sintered NiOx coatings sensitized with ERY;
[0050] FIG. 7 shows the photovoltaic performance of ERY sensitized NiOx coatings when assembled in a photovoltaic cell and measured under standard conditions using an AM 1.5 solar simulator (I: 870 W m −2 );
[0051] FIG. 8( a ) shows the FIB-SEM cross-section image of the NiOx sample sintered for 5 minutes in a furnace;
[0052] FIG. 8( b ) shows the FIB-SEM cross-section image of the NiOx sample sintered for 5 minutes in the microwave plasma apparatus;
[0053] FIG. 9( a ) shows the FIB-SEM cross-section image of a TiO 2 sample sintered for 30 minutes in a furnace;
[0054] FIG. 9( b ) shows the FIB-SEM cross-section image of a TiO 2 sample sintered for 5 minutes in the microwave plasma apparatus;
[0055] FIG. 10 shows the comparative XRD spectra of TiO2 coatings sintered for 5 minutes using the microwave plasma technique and for 30 minutes using a furnace at 500 degrees C.; and
[0056] FIG. 11 shows a nebulizer used for spraying dispersions onto a substrate;
[0057] FIG. 12 is a photograph of a sample employing a polymeric substrate and TiO 2 coating when held in place with a glass slide on a cooling stage;
[0058] FIG. 13 is a photograph of a sample employing a polymeric substrate and TiO 2 coating following plasma treatment when an intermediate sample holder is employed between the polymer and the cooling stage;
[0059] FIGS. 14 a - 14 e show the results of subjecting samples to Rockwell tests ( FIGS. 14 a and 14 b ) and bending tests ( FIGS. 14 c , 14 d and 14 e );
[0060] FIG. 15 shows a cross-sectional comparative analysis of the adhesion between a TiO2 coating and a substrate when deposited without TIP and when TIP is used as a co-depositing layer;
[0061] FIG. 16 is a pair of SEM micrographs of the top surface of TiO 2 coatings after deposition and after subsequent plasma treatment;
[0062] FIG. 17 shows the IV curves of TiO 2 coatings on ITO-PEN substrates when subjected to different sintering techniques and when compared with TiO 2 coating on an FTO-glass substrate;
[0063] FIG. 18 is a photographic illustration of the flex test method; and
[0064] FIG. 19 shows the IV curves of cells of dyed TiO 2 coatings which had been previously subjected to repeated bending at 20 degrees before assembly of the cells.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
EXAMPLE 1
NiOx Nanoparticles on FTO Glass Substrate
[0065] Sample Preparation
[0066] In order to prepare photovoltaic electrodes, fluorine doped tin oxide (FTO) glass substrates (3 mm thick) supplied by Mansolar. The glass substrates (2×2 cm) were ultrasonically cleaned in propanol followed by acetone, each for 5 minutes. Other typical substrates which may be used include indium doped tin oxide (ITO) glass and polymers e.g. PET.
[0067] A deposition layer medium was made, comprising NiOx nanoparticles (˜50 nm) suspended in methanol (20 mg/ml) as a dispersion medium. This deposition layer medium was deposited by spraying using a nebulizer (Burgener Mira Mist atomizer) which uses an inert gas to break up the suspension into small aerosol droplets. In this case, the inert gas used was nitrogen at a flow rate of about 2 litres/min. The nebulizer was moved over the surface of the substrate in a raster pattern using a computer numeric control (CNC) device with a line speed of 20 mm/s and a step interval of 1 mm. The distance from the tube orifice to the substrate was fixed at 10 mm. During deposition, the glass substrates were mounted over a heating block to maintain the substrate temperature at approximately 50 degrees C. The methanol evaporated once deposited to leave a layer of loosely bound NiOx nanoparticles on the substrate.
[0068] Samples prepared in this way were subjected to microwave plasma processing as will now be described with reference to FIG. 1 . Some comparative tests were done against samples prepared in the same way but subjected to conventional furnace sintering in air using a Carbolite Furnace (RHF 1200).
[0069] Microwave Plasma Processing
[0070] FIG. 1 shows an apparatus used in the manufacture of a photovoltaic electrode, comprising a plasma chamber 10 which is pressure controlled using a gas supply inlet 12 and a vacuum outlet 14 . In the processes described below, the pressure was controlled to form a plasma at a pressure of 20 mbar in an argon and oxygen atmosphere in a ratio 10:1 (argon:oxygen).
[0071] A sample stage 16 is located within the chamber 10 to support one or more substrates (not shown) upon a sample holder 18 for processing. The sample stage is height-adjustable, rotatable, and is water-cooled. In the set-up used to generate the results described herein, three samples were treated at a time upon the sample holder 18 .
[0072] A Muegge microwave power supply 20 operating at 2.4 kW and 2.45 GHz provides microwave energy 22 via a tunable waveguide 24 having a tuner 26 , through a quartz window 28 into the chamber 10 , where it excites a plasma ball 30 located above the sample holder 18 .
[0073] Substrate temperatures were measured using a LASCON QP003 two-colour pyrometer (not shown) from Dr Merganthaler GmbH & Co.
[0074] Cample Characterisation
[0075] The NiOx film thickness was measured by step height measurement using a WYKO NT1100 optical profilometer in vertical scanning interferometry (VSI) mode. For the cross sectional investigations, the coatings were mounted on stubs using double-sided carbon tape, and sputter coated with platinum, using a Emitech K575X sputter coating unit, to prevent surface charging by the electron beam. Samples were then examined using a FEI Quanta 3D FEG DualBeam (FEI Ltd, Hillsboro, USA). X-ray Diffraction (XRD) measurements were carried out using a Siemens D500 diffractometer operating at 40 kV and 30 mA with Cu Kα radiation in normal diffraction mode at 0.2°/min scan rate.
[0076] Dye Sensitization, UV-vis Measurements and IV-Characteristics
[0077] NiOx coatings were sensitized with 0.3 mM Erythrosin B (ERY) dye, in a 99.8% ethanol solution for 24 h. The dye adsorption was investigated in transmission mode using an AnalytikJena Specord 210 UV-vis spectrophotometer in the wavelength range of 350-700 nm. The photovoltaic performance (I-V characteristic) of dye sensitized NiOx coatings were analyzed in two electrode configuration using 870 W m −2 AM 1.5 solar simulator and platinum coated FTO was used as a counter electrode. The p-type behavior of ERY-sensitized NiOx coatings was observed using a custom made photoelectrochemical cell in three-electrode configuration: Working electrode was ERY-NiOx on FTO; counter electrode was platinum, where SCE was utilized as a reference electrode. The Electrolyte was 0.5 M LiI and 0.05 M I 2 in Propylene Carbonate (from Sigma-Aldrich).
[0078] Results and Discussion
[0079] Loosely adherent NiOx particulate layers were prepared from the metal oxide/methanol slurry using the spray technique described above. The layer thickness was maintained between 1-2 μm.
[0080] Referring to FIG. 2 , the effect of sintering time on crystallite size was evaluated for samples sintered from 1 to 10 minutes using the microwave plasma sintering technique described above, prior to addition of the dye. For brevity, this microwave plasma sintering technique is referred to as “rapid discharge sintering” or “RDS”. FIG. 2 shows the X-ray diffraction data in the NiO (200) plane for samples sintered for 1, 3, 5, 7 and 10 minutes.
[0081] Using the Scherrer equation to examine the XRD data, an increase in crystallite size from 6.5 to 19.0 nm was observed on increasing the sintering time from 1 to 10 minutes. The Scherrer formula gave a crystallite size of 6.5 nm for each of the samples sintered for 1 minute, 3 minutes and 5 minutes. For the sample sintered at 7 minutes the crystallite size was calculated at 12 nm, while for 10 minutes the size was 19 nm.
[0082] Referring to FIG. 3 , in order to compare the performance of RDS technique with conventional furnace treatments, the NiOx coatings were also sintered at 450° C. for 5 minutes in a box furnace. The properties of the furnace sintered coatings were then compared with those obtained using the RDS technique. XRD examination of the sintered NiOx coatings demonstrated a significantly smaller crystallite size of 6.5 nm for the microwave plasma sintered samples, as compared to the 14 nm obtained after the furnace treatment. Thus the smaller grain size along with more homogeneous heating/sintering is achieved using the RDS technique thus helping to maintain the mesoporous structure of the NiOx nanoparticles.
[0083] Referring to FIG. 4 , after treatment of the RDS samples with the ERY-B dye, the UV-vis absorption spectra of the samples prepared under different sintering times showed a gradual decrease of the amount of adsorbed dye for the coatings with the smaller crystallite size to those with the largest crystallites. The line with the highest peak in FIG. 4 is the reference of the ERY-B dye in solution.
[0084] Referring to FIG. 5 , comparative data can be seen for the 5 minute RDS sample and the 5 minute furnace sintered sample. Again the reference is shown for ERY-B solution. From this it can be seen that the RDS sample has a far greater degree of dye absorption, probably due to rougher surface morphology.
[0085] FIG. 6 shows the p-type behavior of ERY-sensitized NiOx coatings (RDS5). The curves in dark and under UV illumination demonstrated cathodic photocurrents of ERY-sensitized NiOx coatings with an onset of photocurrent at approximately +120 mV vs. SCE reference.
[0086] Next, the open current photovoltage (V OC ), the short circuit photocurrent density (I SC ) and overall photocurrent efficiency (η), were measured as a function of sintering time. FIG. 7 details the I-V characteristics of the ERY sensitized NiOx coatings sintered at different times (thickness: 1-2 μm). Though dye adsorption levels were higher for the 1 minute sintered coatings, the 5 minutes sintered sample (RDS5) exhibited the highest efficiency. These sintering conditions facilitate a high level of dye diffusion, while maintaining interconnectivity between individual oxide grains. Thus the mesoporous sintered metal oxide structure facilitates efficient charge injection from the ERY dye. A subsequent study with 2.5 μm thick NiOx coatings also demonstrated a similar trend.
[0087] FIG. 8 shows focused ion beam/scanning electron microscope (FIB/SEM) cross section images of NiOx coatings obtained after 5 minute sintering using (a) the furnace and (b) microwave plasma. In each image, one can see the sintered NiOx layer 34 , the FTO layer 36 , and the underlying glass substrate 38 . It is clear from these images that the RDS sintered coating exhibits a higher level of bonding at the interface 40 between the NiOx coating and FTO layer, as seen by the elimination of the dark gap seen a this interface in FIG. 8( b ). A possible explanation for this is that the RDS treatment involves volumetric heating, which provides more effective heating inside the metal oxide coating matrix than obtained with the conductive heating obtained using the furnace. Indeed the latter treatment may give rise to selective heating of the outer surface of a coating to produce a heat affected zone [ 37 ]. From FIG. 8 it is also clear that the RDS sintered oxide yields a much rougher surface morphology, which would also assist dye adsorption ( FIG. 3 b ).
[0088] Finally, the photovoltaic performances (open circuit voltage, short circuit current, fill factor, and percent efficiency of both RDS5 and CS5 (i.e. the notation CS5 denotes the 5 minutes furnace sintered sample) coatings were measured as detailed in Table 1, and comparative values are given for two of the best performing electrodes as reported in the literature, namely He et al. [J. He, H. Lindström, A. Hagfeldt, S.-E. Lindquist, Solar Energy Materials and Solar Cells, 62 (2000) 265-273] and Nattestad et al. [A. Nattestad, M. Ferguson, R. Kerr, Y-B. Cheng, U. Bach, Nanotechnology, 19 (2008) 295-304]. The measurements carried out by He and by Nattestad were also obtained under the same test methodology. The Nattestad results were obtained using the dye Erythrosin-J rather than the Erythrosin-B
[0089] The furnace sintered coatings reported here are broadly similar in efficiency to the values reported in the literature while those obtained with the RDS treatment exhibit significantly higher performance, i.e. a tenfold increase of conversion efficiency was observed for the 5 minute RDS sintered NiOx coatings as compared to the 5 minute furnace sintered sample. Results are given in Table 1 for samples sintered in the furnace for both 5 minutes (CS5) and 30 minutes (CS30).
[0000]
Sintering
Sample
time
V OC
I SC
Efficiency
(NiO thickness)
(min.)
(mV)
(mAcm −2 )
FF
(%)
Rapid Discharge
5
120.00
1.05
36
0.0450
Sintered (RDS5)
(~2.5 μm thick)
Furnace Sintered
5
84.00
0.22
25
0.0050
(CS5)
(~2.5 μm thick)
Furnace Sintered
30
35.29
0.21
26
0.0023
(CS30)
(~2.5 μm thick)
He et al. (~1 μm thick)
60
83.00
0.20
27
0.0070
Nattestad et al.
20
120.00
0.36
26
0.0110
(~1.6 μm thick)
[0090] Preparation of n-type Electrode
[0091] An n-type electrode based on titanium dioxide and ERY-B was made according to the same techniques as described above. Using the same FTO glass substrates, a deposition layer slurry was created using titanium dioxide nanoparticles (“Aerosil® P 25” from Evonik Industries) having an average particle size of 21 nm, and methanol (25 mg/ml). This mixture was again sprayed on the glass substrate using a nebulizer, in this case in a layer 9 microns thick, and samples were subjected to both conventional and microwave plasma sintering.
[0092] FIG. 9 shows comparative FIB-SEM cross-section images for (a) conventionally sintered (at 500 degrees C. for 30 minutes) and (b) microwave plasma sintered samples sintered for 5 minutes.
[0093] The SEM images again show the layers designated with the same reference numerals: sintered TiO2 layer 34 , FTO layer 36 , glass 38 and the interface 40 between the sintered TiO2 and the FTO substrate. As with the NiOx samples described above, one can again see that the RDS sample in FIG. 9( b ) exhibit far less of a gap at interface 40 , which strongly indicates better electrical connectivity and structural integrity relative to the CS sample in FIG. 9( a ).
[0094] Accordingly, the technique of applying to a substrate a deposition layer including semiconductor particles, removing the dispersion medium, and then exposing the weakly bound particle layer to a microwave plasma under conditions leading to sintering of the particles, gives rise to a mesoporous semiconductor layer which is strongly bound with good electrical connectivity to the underlying substrate, and this has been demonstrated both for n-type TiO2 and p-type NiOx.
[0095] In the case of the NiOx photocathodes, using the materials and methods described herein it can be seen that a 5 minute microwave plasma treatment cycle provides optimal conversion efficiency, and improved adhesion to FTO substrates compared with that obtained using furnace treatments. The 44% increase in the quantity of adsorbed dye in the case of the RDS treated coatings significantly contributed to the tenfold increase in light-to-current conversion efficiency, compared with that obtained with the furnace sintered coatings. This enhanced performance of the microwave plasma sintered coatings is associated with their smaller grain size after sintering, higher surface roughness and enhanced level of interconnectivity between grains in the mesoporous metal oxide structure.
[0096] FIG. 10 shows the comparative XRD spectra of the box furnace treated and microwave plasma treated TiO2 coatings, and it can be seen that both exhibit very similar XRD spectra.
EXAMPLE 2
TiO 2 Nanoparticles on Flexible Polymeric Substrate
[0097] Sample Preparation
[0098] Degussa P25 TiO 2 nanoparticles with an average size between 20-25 nm were deposited on ITO-PEN coated substrate (where ITO stands for indium doped tin oxide and PEN for polyethylene naphthalate). The TiO 2 was prepared in a suspension form by grinding the nanoparticles powder in an alumina mortar in order to breakdown the agglomerated particles. The ground paste was then transferred into a recipient using methanol solvent vehicle and diluted to a final concentration of 25-30 mg/ml and further sonicated using a sonication horn probe.
[0099] The TiO 2 suspension was applied to the plastic substrate using a roll-to-roll spraying technique. In this technique the suspension is pumped through a nebulizer, shown in FIG. 11 , and with the assistance of a pressurised gas (nitrogen) is atomised and projected at the surface of the plastic substrate mounted onto a CNC controlled (X-Y-Z) pneumatic table.
[0100] In addition to the TiO 2 suspension, a second suspension consisting of titanium isopropoxide (TIP) (20-25 mmol/l) precursor in propan-2-ol was co-applied using a second nebuliser.
[0101] The titanium isopropoxide (TIP) is used to enhance the adhesion of the TiO 2 coating to the plastic substrate.
[0102] The thickness of the TiO 2 coating (varying between 4 to 10 μm) is controlled by the amount of TiO 2 in the suspension and/or the number of passes of the nebuliser over the substrate.
[0103] In the tests described below and illustrated with reference to FIGS. 12-19 the TiO 2 coatings had a thickness between 4 and 6 microns. This thickness will influence solar to electricity conversion efficiency due to parameters such as the electron transport properties of the coating structure. Also, the quantity of dye adsorbed will be influenced by the TiO 2 coating thickness.
[0104] After the coating deposition the samples were allowed to relax for approx. 20 minutes to thoroughly evaporate the carrying vehicle, leaving the powdered semiconductor particles in a deposition layer on the substrate.
[0105] Microwave Plasma Processing and Morphological Analysis
[0106] Sintering of the dried TiO 2 coatings was then carried out in oxygen plasma generated using a 2.45 GHz microwave generator. The plasma gas pressure was maintained between 4-5 mbar with a sample treatment time of 5 minutes.
[0107] The plasma processing apparatus was as shown and as previously described in relation to FIG. 1 , except that oxygen plasma was employed at 4-5 mbar instead of a 10:1 argon:oxygen mixture at 20 mbar (although argon:oxygen mixtures or other plasmas could equally be employed), and (2) a mask was overlaid on the sample as described below.
[0108] The samples were held on the cooling stage of the microwave system using a mask (in this case a 1 mm thick glass slide) to ensure its flatness and intimate contact with the stage as illustrated in FIG. 12 .
[0109] The presence of the cooling stage ensures the integrity of the polymeric substrate; as shown in FIG. 13 the use of an intermediate sample holder (in this case a glass cover as thin as 0.5 mm in thickness) resulted in melting the polymer. This is an indication that the plasma gas temperature exceeded 270-300° C. (as the melting temperature of PEN is reported to be 270° C.—see E. L. Bedia, S. Murakami, T. Kidate and S. Kohjiya; Polymer 42 (2001) 7299 -7305).
[0110] FIG. 14 shows results of the TiO 2 coatings subjected to Rockwell hardness test and bending tests. The coatings were found to easily flake off after indentation was applied to the substrate without the use of TIP precursor ( FIG. 14 a ) whereas stability was greatly improved in the same test carried out on a sample prepared with TIP precursor ( FIG. 14 b ). As shown in FIGS. 14 c , 14 d and 14 e , the use of TIP in the deposition process significantly improved the stability of the TiO 2 coating on the substrate both in initial condition ( FIG. 14 c ) and when bent through 20 degrees ( FIG. 14 d ) and 40 degrees ( FIG. 14 e ).
[0111] The coatings were also evaluated using both High resolution scanning electron microscopy (HRSEM) and focus ion beam (FIB) cross sectional analysis. These analyses further confirmed the weakened nature of the adhesion of the TiO 2 coating deposited without TIP and its intimate contact with the substrate when TIP is used as a co-depositing layer (see FIG. 15 ).
[0112] The SEM micrograph of the top surface of the TiO 2 coatings indicated micro-crack formation in the coating when deposited on the plastic substrate ( FIG. 16 ). This may be related to the spraying parameters and may be eliminated or significantly reduce by further optimisation of the deposition parameters.
[0113] Electrical Characterization
[0114] Further to the morphological analysis of the TiO 2 coating, the photovoltaic performance was assessed by assembling DSSC's and recording their current-voltage (IV) characteristics.
[0115] FIG. 17 shows the IV curve of TiO 2 coatings on ITO-PEN substrates sintered in microwave plasma for 5 minutes or a conventional furnace for 60 minutes at 150° C. The IV curve of a TiO 2 coating on an FTO-glass substrate sintered at 500° C. for 60 minutes is also shown.
[0116] Table 2 compares the conversion efficiency (η) of the same coatings. It is found that the PEN samples sintered in the microwave plasma exhibit 30-35% higher conversion efficiencies when compared to the one sintered in the furnace while it reaches 60% of the conversion efficiencies obtained on the FTO-glass substrate.
[0000]
Glass
PEN Furnace
PEN Microwave
Conversion
5.68
2.08
3.15
Efficiency η (%)
[0117] Furthermore the overall processing cycle time of the samples in the microwave system is only 10-15 minutes including the time taken for loading/unloading of the samples and pumping down of the system.
[0118] FIG. 18 is a more detailed illustration of the steps involved in the flexing test, showing that a flex involved conforming the substrate and coating to both the interior (concave) surface of an annular cylinder and to the outer (convex) surface.
[0119] FIG. 19 shows the IV curves of cells of dyed TiO 2 coatings subjected to repeated bending at 20° (as illustrated in FIG. 18 ) before assembling the cell. It is found that the bending does not alter the IV characteristics of the coatings. | 4y
|
TECHNICAL FIELD
[0001] The present invention relates to fuel cells; more particularly, to means for recycling a portion of the anode tail gas of a solid oxide fuel cell (SOFC) stack into a hydrocarbon reformer supplying reformate to the stack; and most particularly, to improved means for such recycling of anode tail gas to increase overall fuel and reforming efficiency.
BACKGROUND OF THE INVENTION
[0002] Fuel cells for combining hydrogen and oxygen to produce electricity are well known. A known class of fuel cells includes a solid-oxide electrolyte layer through which oxygen anions migrate to combine with hydrogen atoms to produce electricity and water; such fuel cells are referred to in the art as “solid-oxide” fuel cells (SOFCs).
[0003] In some applications, for example, as an auxiliary power unit (APU) for an automotive vehicle, an SOFC is preferably fueled by “reformate” gas, which is the effluent from a partially oxidizing (CPOx) catalytic hydrocarbon reformer. Reformate typically includes amounts of carbon monoxide (CO) as fuel in addition to molecular hydrogen. The reforming operation and the fuel cell operation may be considered as first and second oxidative steps, respectively, of the hydrocarbon, resulting ultimately in water and carbon dioxide. Both reactions are exothermic, and both are preferably carried out at relatively high temperatures, for example, in the range of 700° C. to 1000° C.
[0004] CPOx of hydrocarbon fuels benefits from simple design, robust behavior over the whole range of system operability, long durability and life, and low cost manufacturing. However, the CPOx fuel reforming process is inherently limited to relatively low reforming efficiencies in the 70-80% range.
[0005] Adiabatic fuel reforming with recycle ingestion, combining exothermic and endothermic reforming sequentially within a single reformer, offers the advantage of recycling unused H 2 and CO within the stack anode tailgas back into the system through the reforming reactor, thus enriching the reformate. It is known in the art to recycle a portion of the tailgas from the stack anodes into the inlet to the reformer, which improves stack power density and system efficiency and reduces carbon precipitation and deposition in the system. A problem with this improvement is that a significant pressure drop occurs from the inlet of the reformer to the outlet of the SOFC stack. Thus, a high-pressure flow source is required in the system to return the anode tailgas to the reformer inlet, which source adds significantly to the cost of the system; and further, control may become unstable under low-flow conditions.
[0006] For example, it is disclosed in co-pending application, US 2006/0263657 A1 (“the '657 application”) to employ an aspirator or a gas pump to meter the recycled anode tailgas at a steady and controllable flow rate. However, the aspirator requires a high flow volume of an aspirating gas, which causes a parasitic system loss.
[0007] The gas pump presents a different problem in that a gas pump which can withstand the exhaust temperatures (ca. 700-850° C.) of the stack tailgas must be formed of very expensive high-temperature materials. Therefore, for a presently-practical system employing a relatively inexpensive gas pump, the tailgas is passed through a heat exchanger wherein the temperature is reduced to about 150° C.
[0008] Given that in most prior art cases fuel and air are at best moderately pre-heated (ca. 150° C.) and the recycle is ingested at a low temperature of about 150° C., the ingestion of cooled tailgas into an adiabatic reactor can have several negative effects:
1. Highest efficiencies cannot be reached because the air flow to the reactor must be increased to prevent the onset of carbon formation and stack deactivation. The amount of air generally dictates the efficiency at the outlet of the reactor because the exothermic reactions of the molecular oxygen in the air with fuel create H 2 O and CO 2 rather than H 2 and CO. Maximum efficiencies are around 100% or just above with high recycle flow rates of 30% to 50%. 2. The necessary increase in air flow increases the amount of molecular nitrogen (N 2 ) flow to the system. Nitrogen is an inert to the system. As part of the fluid, however, it must be heated to reforming temperature without performing any useful work. This represents one of the major loss factors of the fuel cell. Further, large amounts of the nitrogen that was heated to reforming temperature returns with the recycle gas at a low temperature only to be heated again. Nitrogen flows of 50% of the total volumetric reformer flow are not unusual at high rates of recycle. Typical nitrogen flows at CPOx and endothermic reforming are around 35%. 3. The high content of nitrogen in the reformate flow acts as a diluent. This dilution of the reforming gases lowers the rate of diffusion of hydrogen and carbon monoxide to the stack anode. The effect is a decrease in power density of the stack which thus requires either a larger stack or leads to lower stack fuel utilization. 4. Last but not least, the ingestion of large amounts of recycle leads to a breakthrough of parent fuel and C2 or higher hydrocarbons. The increased amount of O 2 to the system together with the large amounts of ingested H 2 O and CO 2 keeps the reactor in thermodynamically stable reforming at reforming temperatures well above the carbon formation margin. However, large amounts of unreacted fuel entering the SOFC stack are acceptable only with methane and to some extent with natural gas. The stack cannot tolerate large amounts (5% or more at high recycle rates) of higher hydrocarbons or fuels such as diesel or JP8.
Thus the recycle percentage is limited in the prior art to about 20-25%.
[0013] What is needed in the art is a simplified method and apparatus for allowing endothermic reaction of high levels of tailgas recycle to increase the reformer efficiency.
[0014] It is a principal object of the present invention to increase the overall fuel efficiency of a CPOx reformer coupled to an SOFC by recycling a relatively high percentage of anode tailgas into the reformer.
SUMMARY OF THE INVENTION
[0015] Briefly described, an SOFC fuel cell stack system in accordance with the invention includes a path for recycling a portion of the SOFC anode tailgas into the inlet of an associated hydrocarbon reformer supplying reformate to the stack. The recycle path includes a controllable pump for varying the flow rate of tailgas. A first heat exchanger is provided ahead of the pump for cooling the tailgas via heat exchange with incoming cathode air, permitting use of an inexpensive gas pump as in the prior art. To facilitate endothermic or steam reforming of hydrocarbons, CO 2 , and water in the later portions of the reformer, heat must be increased in the reformer. Some heat may be added back into the tailgas recycle flow stream by installing a second, reversing heat exchanger or an electric heater downstream of the pump. Preferably, the fresh air and fuel being supplied to the reformer is also substantially preheated; and further, the air flow into the reformer is also increased to cause increased exothermic activity (catalytic oxidation and/or combustion) in the early (exothermic) portions of the reformer, thus increasing the amount of heat fed to the endothermic, latter portions of the reformer. The increase in heat supplied to the latter portions of the reformer permits recycling of much larger percentages of tailgas than is allowed by prior art systems, such that overall reformer efficiencies of 130% or greater may be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention will now be described, by way of example, with reference to the accompanying drawings, in which:
[0017] FIG. 1 is a schematic drawing of a first prior art embodiment of an SOFC stack system;
[0018] FIG. 2 is a schematic drawing of a second prior art embodiment, taken in circle 2 , 3 in FIG. 1 ;
[0019] FIG. 3 is a schematic drawing of a third prior art embodiment, taken in circle 2 , 3 in FIG. 1 ; and
[0020] FIG. 4 is a schematic drawing of a first embodiment in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Referring to FIG. 1 , in a first prior art embodiment 10 a of a solid oxide fuel cell stack assembly, substantially as shown as FIG. 1 of the '657 application, hydrocarbon fuel 13 is supplied from a fuel tank 12 via a control valve 14 to a vaporizing chamber 16 . Air 18 is supplied through a filter 20 and a cooling shroud 22 to a main air blower 24 powered by a motor 26 . Blower 24 supplies pressurized air to plenum 28 . A first air control valve 30 meters air 31 from plenum 28 into vaporizing chamber 16 where the air and fuel are mixed into a vapor mixture which passes into a start-up combustion chamber 32 . Chambers 16 , 32 are structurally part of a catalytic hydrocarbon reformer assembly 36 . During cold start-up of the SOFC system, the vapor mixture is ignited by a spark igniter 34 to provide a flow of hot gas through the reformer and the SOFC stack. During normal operation, the vapor mixture is not ignited but rather is passed into reformer 36 wherein the mixture is converted into reformate fuel containing hydrogen and carbon monoxide gases. Reformate is passed across the anode side 37 of SOFC stack 38 . Air is supplied from plenum 28 via a second air control valve 40 and a third air control valve 42 . Air flowing through third control valve 42 is passed through a cathode air heat exchanger 44 and is tempered as described below. The two air streams are joined 46 and passed to the cathode side 47 of SOFC stack 38 . Within stack 38 , oxygen from the air is combined with hydrogen and with carbon monoxide in an electrochemical reaction producing an electric potential across a stack anode lead 48 and a stack cathode lead 50 . Heated and depleted cathode air 51 is exhausted from stack 38 and passed to a combustor 52 . A first portion 53 of anode tailgas exhausted from stack 38 is also passed to combustor 52 , and the air/fuel mixture may be augmented by the addition of air from plenum 28 via a fourth control valve 54 . The tailgas is ignited by a spark igniter 56 in combustor 52 , and the hot exhaust gas 57 is passed through a heat exchanger side 58 of reformer assembly 36 to raise the temperature within the reformer. Exhaust gas 59 from reformer assembly 36 is passed through cathode air heat exchanger 44 to raise the temperature of incoming air and then is exhausted 60 to atmosphere.
[0022] Referring still to FIG. 1 , a second portion 62 of anode tail gas is provided via a recycle flow leg 63 to an inlet to vaporizing chamber 16 via a check valve 64 and a recycle pump 66 comprising an impeller, shaft, shaft bearing, and sealed impeller housing to physically pump the recycle gas. A controllable electric motor drive 68 powers the impeller via the impeller shaft.
[0023] The anode tailgas at the inlet to the pump is at the stack operating temperature range of about 700° C. to 850° C., which can present a challenge with respect to providing bearings and seals suitable for use at these temperatures. Further, the motor must be thermally isolated from these temperatures within the pump.
[0024] Referring to FIG. 2 , in a second prior art embodiment 10 b, an anode tailgas cooler in the form of a second heat exchanger 70 is provided in flow leg 63 ahead of primary cathode air heat exchanger 44 in the cathode air flow 72 from valve 42 . Anode tailgas portion 62 is passed through one side of exchanger 70 , and cathode air 72 is passed through the opposite side. Exchanger 70 reduces the temperature of tailgas 62 to an inlet temperature (tailgas 63 ) to pump 66 suitable for conventional technology (bearings, seals, motors). Further, this reduction in temperature improves the efficiency of the impeller within the pump by increasing the density of the pumped tailgas.
[0025] The cathode air requirement of the system generally tracks with stack power, as does the flow rate of recycle gas 62 . This allows a single passive heat exchanger 70 to effectively cool the recycle gas under all operating conditions. Further, because of the high ratio of cathode air mass flow to recycle gas mass flow under all operating conditions, the recycle gas temperature at the pump inlet is fairly insensitive to changes in cathode air flow volume. Both of these are desirable characteristics of the invention.
[0026] Under some conditions of off-peak system use, however, tailgas 62 may be cooled to a temperature below what is required for proper pump operations. In fact, because the recycled anode tailgas contains a high water content, it is possible that under such conditions water will be condensed in heat exchanger 70 . Because exchanger 70 is a passive device, no direct temperature control is possible. Referring to FIG. 3 , in a third prior art embodiment 10 c an optional electric heater 74 having a low wattage capability can be installed in or around the line between heat exchanger 70 and check valve 64 and can be controlled to maintain the drybulb temperature of anode tailgas 63 above its dewpoint temperature (typically about 75° C.) when entering pump 66 , thus preventing sensible water from entering pump 66 and reformer 36 .
[0027] Referring now to FIG. 4 , a first improved embodiment 110 a is shown in accordance with the invention. Embodiment 110 a is largely the same as prior art embodiments 10 a, 10 b, 10 c and all identical item numbers are shown as in FIGS. 1-3 . The difference is that reformer 36 is not provided with a heat exchanger 58 ; rather a separate heat exchanger 158 is provided to heat incoming tailgas, having a first side for receiving the hot exhaust 157 from combustor 52 which then continues on as exhaust 59 , albeit at a somewhat lower temperature, to prior art heat exchanger 44 as in the prior art. The cool tailgas 63 ( FIGS. 2-3 ) from pump 66 , cooled by heat exchanger 70 prior to entering pump 66 , is directed through the second side of heat exchanger 158 to provide a heated tailgas stream 171 entering into mixing chamber 16 of reformer assembly 36 .
[0028] It will be seen by those of ordinary skill in the art that embodiment 110 a is only one exemplary embodiment for raising the temperature of the cooled anode tailgas 63 between pump 66 and reformer 36 . Obviously, other means (not shown) for providing such heating can be heat exchange with the waste heat in anode tailgas stream 53 and/or cathode tailgas 51 , or electrical heating in known fashion. The operative concept in accordance with the invention, which anticipates all such embodiments, is that the temperature of cooled anode tailgas flow 63 is raised before the tailgas is entered into the reformer.
[0029] A noted above, increased exothermic activity in the early portions of reformer 36 is also highly desirable. Thus, additional heat exchange or electrical heating (not shown) is preferably provided to either or both of air flow 31 and fuel flow 13 prior to their entry into mixing chamber 16 .
[0030] Further, the volume of air flow 31 preferably is increased. In order to use large amounts of recycle, on the order of 40% to 60%, a substantial amount of air must be added to the mixture of fuel and recycle to raise the endothermic reforming temperature through exothermic reactions inside the reforming catalyst. This decreases somewhat the reforming and system efficiency but allows operation of the reformer in a thermodynamically stable fashion which avoids the formation of large amounts of carbon and the destruction of the stack. However, another side effect can be the breakthrough of fuel and higher hydrocarbons (if present in the parent fuel) into the fuel cell stack, as well as substantial dilution of the reformate due to the increase in N 2 through the increase in air flow. Water and CO 2 are present in the reformate, but the reforming temperatures are so low that the time to convert the residual hydrocarbons to H 2 and CO is not sufficient. Thus, it is necessary to preheat the recycle as described above, or still better, to also preheat all the reactants prior to injection into the reforming reactor (not shown) as known by those skilled in the art. Preheat of the reactants allows a significant decrease in the amount of air otherwise required to maintain the reforming process within thermodynamically stable boundaries. At high pre-heat of the fuel/air/recycle mixture, the amount of air can even be lower than the air requirement without any recycle addition. The pre-heat, which utilizes exhaust heat, together with the decrease in air volume at high recycle rates of 40% to 60% can deliver reforming efficiencies of greater than 130% and therefore very high system efficiencies. Adiabatic reformer 36 can be a replaceable, inexpensive ceramic catalyst in contrast to a purely endothermic reformer which is very expensive and cannot be serviced or replaced and must therefore be designed to last much longer.
[0031] As noted above, breakthrough of fuel and higher hydrocarbons into the SOFC stack can be ruinous to the fuel cell anode. Accordingly, a way to solve the problem of hydrocarbon breakthrough is to add a boost endothermic catalyst 76 in series after adiabatic reactor 36 and ahead of fuel cell stack 38 . The boost endothermic reactor is a simple heat change endothermic reactor, as is known in the art and need not be shown or described here, that adds heat to convert any remaining hydrocarbon fuel into H 2 and CO in the presence of large amounts of water and carbon dioxide. Luckily, the present process is not starved of either H 2 O or CO 2 . The boost catalyst may be a rather small device because the gases do not need to be preheated to reforming temperature (already ca. 800° C. from adiabatic reactor 36 ) and a high space velocity is sufficient to reform the remainder of the fuel and higher hydrocarbons. The required heat addition is small and approximately 0.5 kW for a 5 kW system. Another benefit is based on the fact that the boost catalyst can be optimized for endothermic/steam reforming only because the reactor will never be challenged with start-up combustion, air, and molecular oxygen, or CPOx and exothermic high temperature reactions. The boost catalyst system does not require a secondary fuel injection system and is therefore inexpensive and easy to implement even as a retrofit, and can be optimized for long durability and life. The boost reactor system can operate with any hydrocarbon fuel, gaseous or liquid, of any type, e.g., gasoline, diesel, JP8, and the like.
[0032] While the invention has been described by reference to various specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but will have full scope defined by the language of the following claims. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a method for treating at least one stream of aqueous fluid to a defined free residual level of one or more contaminants or other undesirable substituents by using the portable system and apparatus disclosed herein to control introduction of at least one oxidizing chemical, preferably chlorine dioxide, either alone or in combination with other additives. One preferred embodiment of the invention relates to a method for treating water intended for use in industrial, agricultural, food processing, oil and gas, or other applications. More specific examples of such uses include without limitation for treating industrial cooling water, HVAC cooling water, fruit and vegetable wash water, or poultry wash water, primary and secondary disinfecting of potable water, and treatment of aqueous fluids for subsurface applications such as disinfection, drilling, fracturing, well stimulation, sour well conversion, and well cleanout. One particularly preferred embodiment of the invention relates to a method for analyzing and treating source water and produced water (individually or collectively, “frac water”) used in hydraulic fracturing fluids (“frac fluids”) or aqueous fluids used in other processes for oil and gas wells.
2. Description of Related Art
The use of various oxidizing chemicals and non-oxidizing chemicals for treating water and, more particularly, for treating water used in frac fluids is well known. Because such fluids are routinely injected into well bores and subsurface formations, the possibility always exists that some leakage into the underground water table can occur. Some prior art systems and methods have disclosed introducing chlorine dioxide into fracturing fluids downstream of the fracturing fluid holding tanks (“frac tanks”) or forming it in situ downhole. These methods of addition have many disadvantages including, for example, less ability to control the chemical addition or to verify the additive concentration in the treated fluid, lack of portability, lack of a homogeneous blend, limited effectiveness due to pH of the water going downhole, and insufficient contact time or concentrations to kill bacteria. To applicants' knowledge, no one else presently treats the aqueous component of frac fluids upstream of the frac tanks.
A portable system, method and apparatus are therefore needed for effectively and economically treating source water and produced water to a defined free residual level of chlorine dioxide or other oxidizing chemical that ranges from about 0.25 to not greater than about 25 ppm depending upon application and situation. Other beneficial advantages achievable through use of the invention disclosed herein include, for example, the capability for reliably controlling the chemistry of and additive levels in treated water; for safely generating chlorine dioxide in a controlled environment; for independently recirculating, treating and adjusting the chemistry of and additive levels in fluids maintained in individual frac tanks; and, if a leak or overflow of a frac tank occurs, minimizing the amount of treating chemical that is released to the environment with far less harmful environmental impact than would likely be experienced if using traditional water treatment chemistries and methods.
SUMMARY OF THE INVENTION
A portable system, method and apparatus are disclosed herein that can be used to effectively and efficiently treat aqueous fluids by quickly and reliably adjusting and controlling the free residual level of contaminants through the addition of one or more treating agents such as oxidizing chemicals and/or other special-purpose additives, and that can continuously log and report the related fluid composition data on a real-time basis. The entire system and method can be controlled and operated either from the use site or from a remote location. Such aqueous fluids can be used for a wide range of applications including, for example, treating industrial cooling water, HVAC cooling water, fruit and vegetable wash water, or poultry wash water, primary and secondary disinfecting of potable water, and treatment of aqueous fluids for subsurface applications such as disinfection, drilling, fracturing, well stimulation, sour well conversion, and well cleanout. As used throughout this disclosure and the appended claims, the term “free residual level” means oxidizing material available to react with biological species after background contaminants or demand have been converted.
The subject invention desirably includes a capability for monitoring, adjusting, controlling and recording physical and compositional parameters such as volumetric flow rate, pH, total dissolved solids (“TDS”), chlorine dioxide level, density, salinity, conductivity, oxidation reduction potential (“ORP”), viscosity, temperature and pressure of the aqueous fluid, and concentrations of other detectable cations and anions, and for using the resultant information to determine a preferred treatment rate for each treating agent. Examples of such detectable cations include aluminum, ammonium, barium, calcium, chromium (II, III), copper (I, II), iron (II, III), hydronium, lead (II), lithium, magnesium, manganese (II, III), mercury (I, II), nitronium, potassium, silver, sodium, strontium, and tin (II). Examples of such detectable anions include simple ions such as hydride, fluoride, chloride, bromide, iodide, and oxoanions such as arsenate, arsenite, thiosulfate, sulfite, perchlorate, chlorate, chlorite, hypochlorite, carbonate, and hydrogen carbonate or bicarbonate. Although the safe or permitted concentrations of various available oxidizing chemicals can vary, the concentration range of chlorine dioxide that has been determined to be safe for human ingestion is less than 5 ppm, with less than 0.8 ppm being preferred for potable water. The recently proposed “AWW Standard” (for Angelilli, Wong, Williams) is a more preferred standard, however, because it is defined in terms of the requirements under the relevant U.S. EPA and FDA standards. Under the AWW Standard, chlorine dioxide concentrations ranging from 0.25 up to 5 ppm are preferred for fluids pumped downhole, while the chlorine dioxide concentration for produced water should not exceed 0.8 ppm. For use in the present invention, operational levels of unreacted chlorine dioxide ranging from about 0.25 to about 25 ppm are acceptable, with levels ranging from about 0.25 to about 5 ppm chlorine dioxide, being preferred. A low level, such as 0.25 ppm, of chlorine dioxide in an aqueous fluid indicates, for example, that all bacteria have been removed and the fluid has been disinfected without totally exhausting the supply of the disinfecting oxidizing chemical. The use of additive concentration levels higher than 5 ppm, such as up to 25 ppm for example, is generally preferred where the aqueous fluid is more highly contaminated or where the bacterial or contaminant load is highly variable.
According to one preferred embodiment of the invention, a portable in-line system, method and apparatus are disclosed herein that can be used to blend and treat source water and/or produced water that is utilized in frac fluids pumped into oil or gas wells to reliably control bacterial contaminant levels within a predetermined range. As used herein, the term “source water” includes, for example, surface water from a frac water pond, water drawn from different points within a particular surface water source, trucked-in water, and any other water that may be available from an alternative source such as a pressurized line. The subject frac water management system is intended to operate in-line between the water source and the frac tanks, with the treating chemicals being introduced through an eductor, primarily utilizing the motive force of the frac water supply pumps to provide the energy for chemical mixing. Alternatively, auxiliary pumps can be used if desired for introducing oxidizing chemicals or other additives into the flowing frac water. The system, method and apparatus of the invention can be used to proportionally blend source and produced water, source water from different sources or pick-up points, and source water or produced water in combination with a flow of previously treated frac water as desired.
As used throughout this disclosure and the appended claims, the term “portable” means transportable either by towing or by mounting on or in one or more trailers or motor vehicles so as to provide a self-contained treatment and monitoring system that is rapidly connectable to provide in-line access to other fluid flow lines, devices or equipment. In the context of flow lines, devices or equipment used to implement a hydraulic fracturing operation for an oil or gas well, “portable” includes everything needed to install and operate the system, method and apparatus disclosed herein between frac water supply pumps and frac tanks that are already in place. In this context, it should be appreciated, however, that produced water held in a “flow-back” tank located among or nearby frac tanks should be viewed as part of the aqueous fluid supply system that is disposed upstream of the system, method and apparatus of the invention.
According to another preferred embodiment of the invention, a produced water management system is also provided. Produced water is preferably blended into other source water provided to the system and apparatus of the invention prior to treatment of the frac water in accordance with the method of the invention. A proportional mixing system is disclosed that facilitates such blending in accordance with the objective of treating the resultant mixture to produce treated water having a defined free residual level of contaminants below a predetermined maximum level or within a predetermined range. Using this invention, the water input to a hydraulic fracturing operation can be managed according to parameters and concentrations of detectable cations and anions as identified in paragraph [0005].
The use of sequential treatment points for introducing more than one treatment chemical or additive into a single pressurized flow of aqueous fluid or for introducing a single treatment or additive at sequentially spaced points in a single pressurized flow upstream of the frac tanks is also included within the scope of the present invention. The ability to react in real-time to a changing volume of aqueous fluid or to selectively define the volume of aqueous fluid to be treated using the system, method and apparatus of the invention are both elements of the invention that can be important to achieving operational success and consistently positive outcomes.
According to another preferred embodiment of the invention, an oxidizing chemical agent is used to treat bacterial or other biological contaminants present in frac fluids. A preferred oxidizing chemical agent is chlorine dioxide, although other similarly effective oxidizing agents such as ozone, peroxides and persulfates can be similarly used at varying concentrations with varying results for some applications. Chlorine dioxide is preferably generated in situ within the system and apparatus of the invention from chemical precursors, the preferred method of which includes the use of sodium hypochlorite, hydrochloric acid, and sodium chlorite that are introduced into the reactor in liquid form and that react upon contact with each other in an acidic aqueous environment generally having a pH of less than about 6. The oxidizing chemical is preferably introduced into a zone of turbulent flow of the frac fluid through an eductor disposed upstream of the frac tanks, thereby achieving better mixing and better contact with the particular contaminant(s) then being treated. The treatment rate is preferably regulated automatically by a self-modulating stoichiometric controller that varies the amount of oxidizing chemical delivered to the aqueous fluid stoichiometrically depending upon demand. Use of the system and apparatus of the invention in accordance with the subject method can produce “kill rates” of biological contaminants that typically exceed 99.99%.
By introducing treating chemical or additive into a sidestream drawn from the main flow of pressurized aqueous fluid in accordance with one preferred embodiment of the invention, it is possible to reduce the likelihood or a possible adverse effect or outcome from “overshooting” the target concentration of the chemical or additive. This technique is facilitated by the use of a “PID loop” (process value, interval and derivative) or proportional independent digital control (“fuzzy logic”) system in the design, implementation and use of the present invention.
According to another embodiment of the self-contained apparatus of the invention, integral safety devices are desirably provided that are automatically activated to warn workers of any dangerous level of chlorine dioxide and to isolate the chlorine dioxide generator of the invention, neutralize and purge the apparatus with sodium sulfite without exposure to chlorine, caustic, or otherwise harmful chemicals. Audible and visual alarms, a safety stop and two isolation valves, preferably tritium ball valves, are desirably provided for each reactor. A flow sensor and pressure gauge also provide real-time input to the safety devices used in conjunction with the chlorine dioxide generator. A specially modified PVC cleanout for the chlorine dioxide reactor is also provided.
According to another preferred embodiment of the system and apparatus of the invention, a portable distribution manifold is provided upstream of the frac tanks in a hydraulic fracturing operation, which manifold can be selectively used in accordance with the method of the invention to introduce treated water into one or more frac tanks, or to recirculate frac fluid disposed in one or more tanks for possible further treatment, particularly during periods when hydraulic fracturing operations are shut down or during other quiescent periods when fluid maintained in one or more frac tanks is otherwise at rest. By recirculating frac fluids during such quiescent periods, better homogeneity is maintained within each tank, less precipitation of suspended solids occurs, and the time required to resume hydraulic fracturing operations with a fluid of a known and reliable composition is significantly reduced. According to another preferred embodiment of the invention, a frac tank circulation and monitoring system, method and apparatus are also disclosed that comprise and utilize at least one auxiliary pump, a separate programmable logic controller (“PLC”) and, most preferably, a secondary injection point, to precisely trim or control the residual chlorine dioxide level in each frac tank. This capability for continuously turning the water over and for monitoring and trimming the chlorine dioxide or other additive levels in each frac tank also enables the system operator to control compositional parameters in each frac tank even when the site operator is not performing a hydraulic fracturing operation in the associated well(s). Auxiliary booster pumps are desirably provided within the system and apparatus of the invention to establish fluid circulation through the system and apparatus whenever inlet water supply pumps are not operating during shutdown of the hydraulic fracturing operation. Use of the auxiliary circulation system can also provide freeze protection during otherwise quiescent periods in winter. Because the composition of the frac fluid in each separate frac tank, including the associated contaminant and additive levels, typically varies, use of the subject circulation and monitoring system of the invention facilitates management of the water chemistry in each tank.
According to another embodiment of the invention, a new control, data storage and reporting system is disclosed that has the capability to control operations from either onsite or remote locations and to retrieve and reuse stored data to supplement temporary sensory loss at any point within the system.
BRIEF DESCRIPTION OF THE DRAWINGS
The method of the invention is further described and explained in relation to the following drawings wherein:
FIG. 1 is a simplified schematic of one preferred embodiment of the portable water treatment system of the invention;
FIGS. 2A and 2B together depict a simplified process flow diagram illustrating one preferred embodiment of the method of the invention;
FIG. 3 is a simplified top plan view of one preferred embodiment of a portion of the portable frac water management system of the invention;
FIG. 4 is a simplified front elevation view of the portion of the portable frac water management system shown in FIG. 3 ;
FIG. 5 is a simplified diagrammatic view of one embodiment of a preferred chlorine dioxide generation and handling system of the invention for use in practicing one preferred embodiment of the portable water treatment system and method of the invention using three precursors; and
FIG. 6 is an example of a graphical record and printout generated according to a preferred embodiment of the instrumentation and control system for monitoring chlorine dioxide levels in an aqueous fluid treated in accordance with the system, method and apparatus of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in simplified form in FIG. 1 , portable water treatment system 10 utilizes a plurality of inlet water supply pumps 26 , 28 , 30 and 40 supplying water to a portable carriage device, most preferably a trailer 12 , as defined above. If needed, depending upon factors such as, for example, the number and size of the flow lines, and the size of trailer 12 or such other towable or motorized carriage device as may be used, all or part of the apparatus of FIG. 1 disposed between the water inlet lines exiting the pumps and frac tanks 56 , 58 , 60 , 62 can be installed in two or more companion devices such as two trailers, a truck and a trailer, or the like, or can even be skid-mounted for rapid deployment and installation at a use site. If installed inside a trailer, truck or the like, the subject apparatus can be installed in modules on racks, rails or skids as needed and secured in place by appropriate conventional or commercially available means.
Utilizing crossover 32 , which will contain at least one valve that is not shown, either or both of pumps 26 , 28 can draw source water from a plurality of pick-up points 22 , 24 in frac water pond 16 . It should be appreciated that valving and instrumentation are not shown in FIG. 1 , which is intended to lay out an example of one suitable flow scheme as implemented at a use site. It should also be appreciated that the chemistry and solids content of the frac water drawn from different pick-up points in the same frac water pond 16 can vary. Although flow lines 34 , 31 from pumps 26 , 28 , respectively, are depicted as providing a single combined inlet flow to portable treatment system 10 , it should be appreciated that more than a single flow line from frac pond 16 to portable treatment system 10 can be provided if desired.
Pump 30 can optionally draw produced water from an auxiliary source such as a frac tank dedicated to flow-back service, or can draw water from another source to provide another pressurized inlet to portable treatment system 10 as desired. By providing a crossover line 35 with a control valve between lines 34 and 36 , source water and produced water can be blended together in any desired proportion prior to reaching portable treatment system 10 . If the auxiliary source is already pressurized, a bypass line 37 can be provided to bypass pump 30 . If needed, still another auxiliary aqueous liquid source such as tank truck 42 can be provided. As shown in FIG. 1 , pump 40 can recirculate aqueous liquid through tank truck 42 , or can pump the liquid directly to portable treatment system 10 through another inlet flow line 38 . Although pump 40 is shown as being free-standing, it will be appreciated that pump 40 can also be mounted on tank truck 42 .
As is discussed in greater detail below, a significant advantage of portable treatment system 10 of the invention is that inlet water supply pumps 26 , 28 , 30 are typically already in place at the well site for pumping inlet water to a conventional hydraulic fracturing system. By providing quick-connect couplings to the inlet lines that are already built in to portable treatment system 10 , the hook-up time is minimized. Because the force required to move the frac water through the system and apparatus of the invention is provided by the regular inlet water supply pumps, no additional pumps are required except as described below for other auxiliary portions of the subject system. In a typical installation, the inlet lines to portable treatment system 10 are about 10 inches in nominal diameter and carry up to about 6500 gallons per minute at a pressure of up to about 120 psi. This same motive force is desirably used in a preferred embodiment of the invention to educt treating chemical such as chlorine dioxide, first into a sidestream and then into the primary fluid flow.
The structure, use and operation of apparatus disposed in trailer 12 in portable treatment system 10 of the invention to treat the source and produced water in accordance with the method of the invention are further described below in relation to FIGS. 2-6 . It should be understood that the number of individual flow lines and the number of additive injection points in each flow line can vary within the scope of the invention. Although three separate inlet flow lines 34 , 36 and 38 are shown entering trailer 12 in FIG. 1 , the number can be one or more and, if desired, an inlet manifold can be provided to proportion and distribute flow into any one of a plurality of individual flow lines to serve as the primary fluid flow paths through portable treatment system 10 . One significant advantage of water treatment system 10 is that all the flow sensors, instrumentation and controls are desirably electronically linked to at least one programmable logic controller (“PLC”) and data storage and retrieval unit disposed inside trailer 12 and also to at least one PLC and data storage and retrieval unit located at some remote site. This control system enables users to operate system 10 and to control the method and apparatus of the invention from the well site or, if needed, from a remote location. Also, while system 10 is preferably operated using real-time data, it can also be operated using saved operating data and parameters should needs dictate, especially for short periods of time.
Referring again to FIG. 1 , following treatment of the water directed through the individual flow lines inside trailer 12 , two treated water streams 44 , 46 are shown entering manifold 14 . From manifold 14 , the treated water can be selectively discharged through flow lines 48 , 50 , 52 , 54 into any one or more of frac tanks 56 , 58 , 60 or 62 , respectively. Although four frac tanks are shown, more or fewer frac tanks can be used within the scope of the invention. In conventional practice, the chemistry and contaminant level of the various frac tanks can vary greatly, and one or more frac tanks can be dedicated to flow-back water that is recovered from the wellbore subsequent to hydraulic fracturing.
Depending upon the construction of and the flow control system used for manifold 14 , the water introduced into frac tanks 56 , 58 , 60 and 62 through flow lines 48 , 50 , 52 , 54 can have the same or different chemistries as desired, but according to a preferred embodiment of the method of the invention, all treated water entering any one of the frac tanks will have free residual levels of any treating chemical that do not exceed predetermined maximum values.
On the outlet side of frac tanks 56 , 58 , 60 and 62 , outlet flow lines 64 , 66 , 68 and 70 are provided as a flow path for treated frac water to move to blender 72 , where it can be combined with other conventional additives such as proppants and the like that are used in hydraulic fracturing fluids. One or more booster pumps, not shown, can be provided downstream of frac tanks 56 , 58 , 60 , 62 to move treated frac water to and through blender 72 from the frac tanks, and from blender 72 to the primary injection pump, not shown, for the hydraulic fracturing fluid. Although the flow of fracturing fluid from the frac tanks to the blender and then downhole is conventional technology and is not part of the present invention as narrowly defined, it should be noted that recirculation lines 82 , 84 , 86 and 88 from frac tanks 56 , 58 , 60 , 62 , respectively, back to portable treatment system 10 are part of the invention. The provision and use of system 10 having the capability of selectively recirculating and treating fluid from any one or more of the frac tanks by the use of one or more auxiliary pumps (seen in FIG. 2B ), even when all of primary pumps 26 , 28 , 30 , 40 are shut down, enables an operator to consistently maintain the same or different fluid chemistries in each frac tank as desired. It should be understood and appreciated that individual recirculation lines 82 , 84 , 86 and 88 can be used to carry fluid back to the chemical treating portion of system 10 independently, or can be consolidated into a single return header as desired, providing such pumps as may be required to implement such various flow schemes.
Unlike conventional hydraulic fracturing systems, frac water treatment system 10 of the invention provides the capability for intermittently or continuously recirculating aqueous liquid from each individual frac tank back to the water treatment trailer, where the water chemistry and additive levels in each frac tank can be adjusted as desired. Auxiliary pumps are desirably provided inside portable treatment system 10 to provide motive force for the recirculation. Such recirculation helps prevent settling of solids into the bottom of each frac tank, promotes mixing and homogeneity of the fluid inside each tank, and provides freeze protection at low ambient temperatures. The ability to maintain desirable water chemistry and additive levels in each frac tank as desired during periods of inactivity when hydraulic fracturing operations are not underway reduces the start-up time otherwise required when activities resume and provides a more consistently reliable frac water source than has previously been available to those engaged in drilling and production. Frac water recirculated from the frac tanks to portable treatment system 10 and treated in accordance with the method and apparatus of the invention as are further described below in relation to FIGS. 2-6 is desirably returned to frac tanks 56 , 58 , 60 and 62 through recirculation return lines 74 , 76 , 78 and 80 , respectively. It should be appreciated by those of skill in the art upon reading this disclosure that the system, method and apparatus of the invention will enable an operator to discharge treated aqueous fluid directly into any selected frac tank, or to discharge treated fluid into manifold 14 from which it can also be distributed into any one or more frac tanks as desired.
Where one or more frac tanks are used to hold flow-back or produced water, that water can be recirculated to portable treatment system 10 and proportionally blended into source water as previously described, or can be separately treated and returned to the flow-back tank as described above for the recirculated aqueous liquids. In the former case, the treated produced water flows into manifold 14 with the other treated source water, and in the latter case, the treated produced water flows directly back into the flow-back or produced water tank.
Generally speaking, the method of the invention includes determining the inlet flow rate and an initial set of fluid properties and compositional parameters for the incoming frac water. Such parameters can include, for example, volumetric flow rate, pH, TDS, chlorine dioxide level, density, salinity, conductivity, ORP, viscosity, temperature and pressure of the aqueous fluid, and concentrations of other detectable cations and anions, and for using the resultant information to determine a preferred treatment rate for each treating agent. Examples of such detectable cations include aluminum, ammonium, barium, calcium, chromium (II, III), copper (I, II), iron (II, III), hydronium, lead (II), lithium, magnesium, manganese (II, III), mercury (I, II), nitronium, potassium, silver, sodium, strontium, and tin (II). Examples of such detectable anions include simple ions such as hydride, fluoride, chloride, bromide, iodide, and oxoanions such as arsenate, arsenite, thiosulfate, sulfite, perchlorate, chlorate, chlorite, hypochlorite, carbonate, and hydrogen carbonate or bicarbonate. Except for the flow rate through the large-diameter pipes, most of the fluid properties and compositional parameters are desirably determined in, and treating chemicals and additives are desirably introduced into, sidestreams of reduced flow that are diverted into and out of the primary flow lines through lateral wyes. To the extent possible, the relevant properties and parameters are determined using in-line sensors and gauges, with valves and sample ports provided as needed to facilitate data and sample collection, and quality control.
By managing the chemistry and composition of frac water upstream of the frac tanks in accordance with the method of the invention, several operational benefits are achieved. Once the initial water properties and parameters are determined, set points are chosen and verified for the concentrations of treating chemicals and additives to be introduced into the fluid flow before the frac water reaches the frac tanks. According to one preferred embodiment of the invention, each treating chemical or other additive (and especially where chlorine dioxide is the primary treating chemical) is introduced in two sequential increments in two different sidestreams that are longitudinally spaced apart along the flow path of each primary flow line. Treating chemicals and additives are desirably introduced into the primary flow lines in regions of turbulent flow to facilitate dispersion. One or more PLCs are desirably used to calculate the addition rates needed to produce a desired final concentration of each treating chemical and additive in the treated water that exits the system, and to operate the valves as needed to achieve the desired final concentration. In some cases, treated fluid can be recirculated through the treating apparatus of the invention to incrementally adjust the concentration of treating chemicals or additives to a desired level.
Through use of the method of the invention, which can be implemented in a preferred embodiment with the portable system and apparatus as disclosed herein, users can now exercise control over the composition of aqueous fluids in ways not previously achievable using conventional water treatment methods. For example, the method of the invention enables one to make real-time adjustments to the concentration of treating chemicals and additives in a pressurized flow of aqueous liquid in response to changes in composition of the incoming source water, no matter whether such compositional changes are attributable to different liquid sources or pick-up points, different degrees of contamination with differing treatment demands, different types and sources of contaminants, or the like. Similarly, the subject method enables one practicing the invention to target and maintain a desired concentration of a particular treating chemical or additive in a pressurized aqueous flow by the sequential addition of differing amounts of the chemical or additive coupled with systematic monitoring and comparison to the benchmark level to determine the desired magnitude of the next compensating adjustment. Use of the subject method also enables an operator to maintain control over the composition of an aqueous stream from the use site or from a remote location and, when the flow of aqueous liquid is interrupted for whatever reason, to continue recirculating an aqueous liquid to monitor and/or treat the fluid as necessary in response to a demand, target concentration, or other such parameter.
As applied to fracturing operations for oil and gas wells in particular, the subject method can be implemented to allow an operator to achieve many different objectives. Such objectives include, by way of illustration and not of limitation, to proportionally blend source and produced water, to treat either inlet stream independently of the other, to treat a combined inlet stream, to treat with one or more oxidizing chemicals either alone or in combination with other additives such as scale and corrosion inhibitors, to retreat sequentially with a single chemical or additive, to selectively direct treated water to and through a distribution manifold that is part of the subject system and that is located upstream of the frac tanks, to selectively recirculate a portion of the treated liquid to be reintroduced into the inlet stream to retreat or to help balance the composition and chemical or additive concentration of the incoming stream, to achieve a targeted chlorine dioxide concentration in frac water, and to recirculate through individual frac tanks to maintain, balance or vary the water chemistry and concentrations of chemicals and additives in various frac tanks.
A preferred method for introducing treating chemical such as chlorine dioxide and additives such as scale inhibitor and corrosion inhibitor into the frac water flowing through the apparatus of the invention is by use of at least one eductor installed in fluid communication with each side stream in which treating chemical or additive is to be introduced. Alternatively or supplementally, one or more treating chemicals and/or additives can be introduced into the fluid flow using small volume positive displacement injection pumps. The treating chemicals or additives introduced into the frac water using the method of the invention can be produced in situ or can be provided in usable quantities or amounts from other sources and stored inside the trailer or in another carriage device that is consistent with applicable storage and handling requirements or regulations and also compatible with the objectives of portability, effectiveness and efficiency during transportation and use of the system, method and/or apparatus of the invention. Such storage means can include, for example, drums, totes, tanks or other containers of appropriate volume in combination with such chemical transfer devices and ancillary controls and safety precautions as are known to those of ordinary skill in the art to be desirable or necessary for the particular conditions or circumstances of use.
A preferred treating chemical for use in the method of the invention is chlorine dioxide, and a preferred method for providing chlorine dioxide to the frac water treatment system of the invention is generating it in situ inside a reactor system that further comprises a dedicated PLC, a reaction chamber with a dedicated alarm and safety system, and a purge and cleanout system. The use of two or more treating chemical reactors or generators is preferred in practicing the method of the invention. Chlorine dioxide can be provided or generated using one, two and three precursor systems and appropriate reactors that are commercially available from various manufacturers or suppliers. A preferred reactor for use in practicing the method of the invention can be used to generate chlorine dioxide from three precursors that meet in liquid form and react in the presence of water sprayed into the reactor. Three preferred precursors are sodium hypochlorite, hydrochloric acid and sodium chlorite. A preferred alarm and safety system for use in the invention comprises both audio and visual alarms, pressure gauges, and remote and onsite automatic and manual safety stop valves that isolate the reactor on both the inlet and outlet sides. A preferred purge and cleanout system includes a sensor-activated sodium sulfite purge and a PVC cleanout that is located above the reactor and is resistant to corrosion and degradation (better than stainless steel) when used in this application. Sodium sulfite is particularly preferred for use in purging the reactor system because of its high, virtually infinite, solubility in chlorine dioxide, and sits on top of the reactor.
One preferred method of the invention is further described in relation to FIG. 2 , wherein source water 202 is supplied to primary flow line 220 from a frac pond or another other pressurized line source. It will be appreciated that conventional, commercially available control valves, check valves, back-check valves, flow meters, gauges, indicators, transducers, transmitters, controllers, control lines, tees, wyes, safety stops, alarms, indicator lights, and the like that are well known to those of skill in the art for implementing a method such as that described herein are not shown in FIG. 2 , which is primarily intended to describe the process flow through the system and apparatus of the invention. More particular mechanical descriptions are provided in connection with FIGS. 3-5 below, which are more narrowly directed to implementation of the chlorine dioxide generation aspect of the invention and introduction of the treating chemicals and additives into the primary flow lines by use of an eductor.
Although only one primary flow line is shown in FIG. 2A , it should be appreciated that two or more primary flow lines can be operated in parallel within the scope of the invention. Produced water 204 is similarly introduced through line 209 into primary flow line 220 . Because frac water supply pumps (seen in FIG. 1 ) are already in place at most well locations, the system and apparatus of the invention can be inserted and connected downstream of the supply pumps and upstream of the frac tanks to pretreat the frac water in a way not previously achievable and using the motive force already in place to move the aqueous fluid through the water treating system.
Scale inhibitor 210 can be introduced into the produced water through line 211 because of the relatively high proportion of mineral contaminants likely to be contained in produced water 204 . Scale inhibitor 210 can be introduced into the pressurized flow of produced water using a commercially available injection pump or by the use of an eductor disposed at the inlet into the flow of produced water 204 . Similarly, although not shown in FIG. 2A , it will be appreciated that corrosion inhibitor or other additives or chemicals can likewise be introduced into produced water 204 or directly into primary flow line 220 if needed. Side streams 206 , 212 , 216 having reduced flow can be provided if desired to facilitate the placement and use of sensors 208 , 214 , 218 for determining flow parameters and compositions as needed.
The primary flows as exemplified by primary flow line 220 each pass through control valves having onsite or remote indicators that display the inlet water flow rates and TDS for each flow. All necessary flow monitoring and control systems are desirably capable of being powered by a self-contained power source such as a combination of auxiliary batteries and generators supporting the system and apparatus of the invention, although AC power can also be provided onsite from remote generators or other available electrical power sources in many cases and converted to DC power where required. Sensors 214 can comprise pressure gauges and flow rate and set point indicators that are linked to valves that control the optional flow of scale inhibitor into produced water 204 . Flow rate and set point indicators similarly control the proportion of produced water 204 that is combined with source water 202 into primary flow line 220 . The aqueous fluid supply lines can also be provided with control valves and safety valves having status indicators and alarms as needed.
Sensors 228 in side stream 226 whose inputs are directed to at least one on-site and at least one remotely located PLC 215 linked with flow rate and set point indicators and control valves determine the flow 224 of inlet water to one or more chlorine dioxide generators 230 . Each PLC 215 is also desirably linked to a data storage and retrieval unit 217 that is capable of providing operational inputs to PLC 215 from stored data if needed due to instrument failure or other circumstances. Each chlorine dioxide generator 230 preferably produces chlorine dioxide from precursors 232 , 234 and 236 that preferably include sodium hypochlorite, hydrochloric acid and sodium chlorite. Although a three-precursor system and the generation of chlorine dioxide within the confines of the portable apparatus of the invention are preferred, it will be understood by those of skill in the art upon reading this disclosure that other devices and systems for providing chlorine dioxide or other oxidizing chemicals can also be used to practice the subject method, such as for example, 1- or 2-precursor systems for generating chlorine dioxide. The use of in situ generation of chlorine dioxide in combination with the use of an eductor instead of injection pumps to introduce the treating chemical into a pressurized flow of aqueous liquid such as frac water has proved to be an efficient and effecting method for managing a frac water treatment system.
Chlorine dioxide generator 230 is desirably provided with safety valves and alarms suitable for isolating the generator in case of an operational failure or unsafe condition. A sodium sulfite purge 240 is desirably provided above generator 230 to flood the chlorine dioxide generator in case of emergency, and cleanout 238 is provided for use in cleaning and restarting the reactor, especially following an emergency shutdown. Treated water flow 242 exiting chlorine dioxide generator 230 can be selectively controlled and directed back into primary inlet water flow 220 through line 243 by control valves having status indicators visible at a proximal and/or remote control panel, with the flow parameters and treating chemical concentration being determined and indicated by sensors 246 disposed in side stream 244 .
A further aspect of the method of the invention relates to frac tank monitoring. According to one preferred embodiment of the invention, a separate controller is provided for each frac tank, and each frac tank is provided with a secondary injection point to precisely trim or control the residual level of chlorine dioxide or other treating chemical or additive in that frac tank. Referring to FIG. 2B , treated water flowing through line 242 can also be selectively distributed through any or all of inlet lines 248 , 250 , 252 and 254 to frac tanks 256 , 258 , 260 , 262 , respectively. Treated water entering primary flow line 220 through line 243 flows into the manifold that is also part of the invention, through which the treated water can be selectively distributed to any or all of frac tanks 256 , 258 , 260 , 262 through inlet lines 290 , 292 , 294 and 296 , respectively.
Referring again to FIG. 2A , one or more other treating chemicals or additives 304 can be introduced into primary inlet water flow line 220 using side stream supply line 302 , return line 310 , each of which can be fully instrumented by one or more sensors 308 , 314 . Side stream 298 and sensors 300 affords an opportunity to monitor the affect of additives 304 on the primary water flow. Generally speaking, various commercially available friction reducers are known to have associated chloride concentration ranges within which they are most effective. For example, some friction reducers are effective at chloride concentrations ranging up to 125,000 ppm and beyond, while many others are not effective at such high chloride concentrations in the treated fluid and are preferred for use only within a lower and narrower range of chloride concentrations. Accordingly, by using the method of the invention, one can choose a chloride set point at which a given friction reducer is known to be effective, and then use the system of the invention to blend inlet water from various sources to manage the chloride content of the fluid being treated within the effective range of that friction reducer. If for any reason the average chloride concentration of the source water or produced water changes substantially, it may become necessary to select a different friction reducer and/or a new chloride concentration set point that will accordingly adjust the amount of friction reducer being introduced into the flow through the system of the invention. It should be appreciated that this example is merely illustrative of benefits and advantages that can be achieved through use of the present invention, and that other benefits are likewise available by selectively adjusting either the blend of inlet water and other aqueous fluid being supplied to the chemical treatment section of the invention, or by selectively adjusting the type and amount of chemical treatment that is introduced into the fluid flow line.
Referring to both FIGS. 2A and 2B , frac tank recirculation lines 276 , 278 , 280 and 282 can be controlled to selectively discharge a controlled flow of frac water into tank recirculation line 284 that utilize auxiliary pump 283 to introduce the recirculated fluid into flow line 220 above take-off lines 224 , 302 for injection of chlorine dioxide 230 and the other additives 304 , respectively. Side stream 286 with sensors 288 is again provided to monitor and report to the PLC the flow parameters and chemistry of the recirculated aqueous liquid. This recirculation loop affords the user the opportunity to continuously readjust the chemistry and additive concentration levels of the recirculated fluid.
During hydraulic fracturing operations, frac water is selectively withdrawn from the individual frac tanks through lines 264 , 266 , 268 , 270 using existing technologies and is discharged into blender 274 , where it can be mixed with other fracturing fluid components and then pumped downhole as indicated by arrow 274 .
An illustrative primary flow configuration through trailer 12 as shown in FIG. 1 is depicted in FIGS. 3 and 4 , and an illustrative sidestream flow through a chlorine dioxide introduction loop 450 is depicted in FIG. 5 . Although a substantially linear piping layout is shown in FIGS. 3-4 , it should be appreciated that the primary flow path can also be looped, for example, if needed due to space restrictions in a particular trailer 12 or other carriage device, and that the number of flow lines is not limited other than by space considerations. Referring first to FIGS. 3 and 4 , piping and instrumentation comprising two parallel and substantially identical primary fluid flow paths embodied in lines 404 , 408 for pressurized source water flows 442 , 446 , respectively, are shown for illustrative purposes. Each primary source water flow line is preferably connectable at its inlet end to one of the source water inlets as previously described, and at its outlet end to an outlet line flowing to manifold 14 disposed inside trailer 12 or between trailer 12 and the existing frac tanks as seen in FIG. 1 . Flow line 406 , shown here disposed between lines 404 and 408 , supplies a flow of pressurized produced water as indicated by arrows 444 .
Referring again to the illustrative apparatus of the embodiment of the invention as depicted in FIGS. 3-4 , and particularly with regard to primary flow lines 408 , female inlet coupling 440 is attachable, for example, to a source water supply line. Flow meter 424 , preferably a MagMeter, is supplied at the inlet end, upstream of lateral wye 438 , which redirects a relatively minor portion of the flow through valve 436 into line 434 . The side stream thereby created can be used to introduce any additive such as, for example, a corrosion inhibitor, into the flow of source water. Following introduction of the additive, the side stream is reunited with the primary flow through line 408 through line 430 , valve 428 and lateral wye 426 . The flow scheme and instrumentation for flow line 404 is substantially identical to that of flow line 408 .
Referring next to produced water flow line 406 , after flow 444 passes through the quick-connect female coupling and flow meter, a portion of the flow is similarly redirected through wye 448 and valve 450 into line 454 . In this case, line 454 can be used for the introduction of a scale inhibitor, for example, as previously discussed in relation to the method of the invention. It should be understood and appreciated, however, that other types of additives or treating chemicals could likewise be introduced into flow 444 of produced water through this side stream. Following reintroduction of the side stream flow through line 456 , valve 458 and lateral return wye 460 , flow 444 passes into tee 462 , where the flow is redistributed by control valves 468 , 470 , preferably connected to a PLC, and smaller tees 464 , 466 into source water flow lines 404 , 408 , respectively. Safety valves 472 , 474 are also desirably provided in tee 462 .
Downstream of the point of combination of treated produced water flow 444 with the treated source water flows 442 , 446 , lateral wyes 414 , 422 are again provided in each of flow lines 404 , 408 . Referring again to line 408 , and assuming for illustrative purposes that lateral wye 422 is intended to create a side stream for an injection point for chlorine dioxide, line 420 directs a sidestream that is identified in FIG. 5 by arrow 452 to the inlet side of one of three substantially identical chlorine dioxide manifolds 481 , 483 , 485 that are depicted at the left side of FIG. 5 . The inlet flow of the sidestream passes through inlet valve 454 , flow meter 458 , chlorine dioxide sensor 460 , ORP sensor 462 , pH sensor 464 , temperature and TDS sensor 466 , past flow sensor 470 , back-check valve 472 , scale inhibitor injection point 474 , past chlorine dioxide eductor 492 , through valve 496 , and back to return line 420 of FIG. 3 as indicated by arrow 498 in FIG. 5 .
Referring to the right side of FIG. 5 , chlorine dioxide precursors 476 , 478 and 480 , preferably comprising sodium hypochlorite, hydrochloric acid, and sodium chlorite, respectively, are introduced into chlorine dioxide generator 484 that incorporates each of the subsystems previously discussed. Chlorine dioxide produced in generator 484 exits through an outlet manifold as indicated by arrow 486 and flows through a motor operated control valve 488 into eductor 492 . The flow of frac water containing the chlorine dioxide introduced into the sidestream through eductor 492 flows through outlet valve 496 and out of the treatment loop as indicated by arrow 498 . As previously discussed in relation to FIG. 2 , chlorine dioxide generator 484 is desirably provided with safety valves, alarms (preferably onsite and remote audio and visual alarms), and a purge system 485 and cleanout 487 .
Referring again to FIG. 3 , the returning flow of chemically treated frac water can be reintroduced into primary flow line 408 through a return line, valve and lateral wye (not shown), or can be diverted directly to a frac tank as previously described. Valve 418 is desirably provided to control downstream flow. Where the flow from the treated side stream re-enters primary flow line 408 , turbulence is created that promotes dispersion and mixing of the chlorine dioxide throughout the source water flowing through line 408 . Referring to FIG. 4 , it is seen that lateral return wye 426 is a dual wye provided with two return positions so that the return flow can be further distributed if desired. Similarly, a dual wye can be used on the take-off side where the same or different additives are to be introduced at a single point in the flow stream. A principal purpose for creating another sidestream flow is to provide a secondary point for introduction of chlorine dioxide using a chlorine dioxide manifold as described above in relation to FIG. 5 . Other sidestream flows can be similarly created for use in introducing other treating chemicals or additives into primary flow line 408 , either by means of other sampling and eductor loops, or by sidestream loops utilizing injection pumps. In some situations, particularly where a portion of the primary frac water flow has been recirculated and introduced into primary flow line 408 from one or more individual frac tanks, the inlet flow to a treating chemical or additive introduction sidestream may be obtained from the use of multiple wyes and side streams.
Referring to FIG. 6 , graphical report 500 is merely an illustrative example of the type of data than can be routinely gathered and of a report that can be generated using the system, method and apparatus of the invention. Graph 502 is a plot of chlorine dioxide concentration (ppm) over an indicated time interval, with separate plots 504 for each of four different frac tanks. Table 506 records by tank the treatment chemical (chlorine dioxide) being used, and the minimum, maximum and average chlorine dioxide concentrations (ppm) recorded for each tank. Table 508 records the minimum and maximum chlorine dioxide concentrations overall that were recorded during the reporting period for the four tanks. Use of portable water treatment system 10 as disclosed herein will not only provide operators with greater reliability and tighter control over chemicals and additives injected downhole, but will provide an accurate historical record of the chemistry and composition of the frac water pumped downhole should a need arise to establish such information in a reliable, systematic and trustworthy format.
In conclusion, the present invention allows the trending and correlation of other systems to help advance the chemistry of any subject process and the complete control and automation of the fluid entering into the hydraulic fluid fracturing process. The subject system can react to the ever-changing conditions of the fluid in each of the manifold's pipes since the fluid may be from more than one source and or different pick-up points from each source. The pumps pressures and fluid flow rates can also vary from pump to pump.
According to a preferred embodiment of the invention as disclosed herein, chlorine dioxide manifold 450 as disclosed in relation to FIG. 5 has in each of its three separate inlet lines a MagMeter as flow meter 458 to measure flow rates, a programmable flow switch 470 , a series of valves on the inlet and outlet of each pipe, a special injection plate and/or fittings for chemical additions, and an inlet and outlet for a side stream flow of water that allows for the monitoring of the chemicals that are being introduced through the manifold. The manifold will measure the flow rate of fluid through the piping manifold in GPM, CFS, LPM, and may be converted into any quantifiable measurement and reports this locally and/or remotely. The subject manifold 450 relies on pressurized water flow from existing frac water pumps but auxiliary pumps 456 can be provided for recirculating fluids to the frac tanks. Flow meter 458 detects flow of fluid and sends a signal based on any measurement (such as “show flow when >1 GPM and “no flow” when <1 GPM) that is programmable set point and reports this locally and/or remotely.
With a series of valves and supply line outlets and return line inlets, portable treatment system 10 can divert a sidestream of fluid and flow that fluid to any other type of chemical treatment and monitoring process. In manifold 450 , which will also allow for other chemical treatments to be injected directly into the manifold, each of the lines is independent from the others and therefore there are at least three separate systems and/or processes that all can work at the same time.
Manifold 450 will also allow for chemical treatments that are being injected into each line of the manifold to be injected in at one and/or multiple points so as to evenly distribute the chemistries into the primary flows of frac water through portable treatment system 10 . This allows for a quicker reaction and a homogeneous blend between the chemistry and the ever-changing characteristics of the water.
Manifold 450 allows each 10-inch line to be treated differently and independently from the others. Since the water flowing through the manifold may not be from the same source and/or if from the same source the pick-up points may cause a variation in the water's characteristics.
Through use of the system, method and apparatus disclosed herein, control, adjustment, feed rates, spill detection remote control and calibrations of all chemicals for any and all part of the inlet fluids on a hydraulic fracturing process. The actual flow rate of fluid to be treated and the total quantity of fluid treated during each phase of the process and a total at the end of each process. Chemistries are best added in ppm based on actual fluids being used and no one is believed to be doing this.
Other alterations and modifications of the invention will likewise become apparent to those of ordinary skill in the art upon reading this specification in view of the accompanying drawings, and it is intended that the scope of the invention disclosed herein be limited only by the broadest interpretation of the appended claims to which the inventors are legally entitled. | 4y
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TECHNICAL FIELD
[0001] The present invention relates to polyimide materials. More specifically, the present invention relates to polyimide materials composed of polyamic acid having a specific diamine unit with controlled geometric isomerism, and to processes for producing the same.
BACKGROUND ART
[0002] Polyimides generally have superior heat resistance, mechanical properties and electrical characteristics compared to other general-purpose resins and engineering plastics. And also, wide applications of polyimides are founded such as molding materials, composite materials, electrical and electronics materials, optical materials, etc. Meanwhile, the use of lead-free solder in the manufacture of electrical circuits, including flexible printed boards, has become mainstream due to the increasing trend in environmental issues. Due to the high reflow temperature required for lead-free solder, polyimides that offer higher heat resistance than conventional ones are in increasing demand.
[0003] One effective technique for increasing the glass transition temperature (Tg) of polyimide resin is to optimize the monomer skeleton that constitutes the polyimide. For example, a diamine compound or tetracarboxylic dianhydride having a particular structure is introduced or copolymerized with conventional polyimide structure in an aim to improve the physical properties, such as heat resistance and/or mechanical properties, of the polyimide (see, e.g., Patent Literatures 1 and 2). However, new monomers are sometimes not versatile materials because of possible adverse effects on other physical properties, the difficulty with which they are synthesized, or the use of expensive raw materials.
[0004] Another effective technique for increasing the Tg of the resin is to introduce a functional group that undergoes thermal crosslinking into a terminal of the polyimide (see Patent Literature 3). However, this method involves altering the molar ratio between the added monomers. This inevitably results in a decrease in the molecular weight of the polyimide resin, possibly affecting its physical properties.
[0005] Under the foregoing circumstances, there has been a growing demand for technology that can increase the heat resistance of polyimide to a level higher than that of conventional one without changing its primary structure.
[0006] Bis(aminomethyl)cyclohexane is a diamine having an alicyclic structure. Thus, a polyimide prepared by reaction of this compound with an aromatic tetracarboxylic dianhydride is a semi-aromatic polyimide, a compound that exhibits high transparency (see Patent Literature 4). For this reason, bis(aminomethyl)cyclohexane holds great promise for future applications.
[0007] Bis(aminomethyl)cyclohexane has two structural isomers: 1,3-bis(aminomethyl)cyclohexane and 1,4-bis(aminomethyl)cyclohexane, each of which is known to exist as two geometric isomers: cis-trans isomers.
CITATION LIST
Patent Literature
[0000]
[PTL 1] Japanese Patent Application Laid-Open No. 2003-212995
[PTL 2] Japanese Patent Application Laid-Open No. 2003-212996
[PTL 3] Japanese Patent Application Laid-Open No. 2006-291003
[PTL 4] Japanese Patent Application Laid-Open No. 2003-141936
SUMMARY OF INVENTION
Technical Problem
[0012] In view of the foregoing problems pertinent in the art, it is therefore an object of the present invention to provide a polyimide resin having higher heat resistance than conventional one by controlling the geometric isomerism of a constituent unit without changing the primary structure of the polyimide resin.
Solution to Problem
[0013] The inventors completed the present invention by discovering that the glass transition temperature (Tg) of polyimide having 1,4-bis(aminomethyl)cyclohexane as a diamine unit is correlated with the cis/trans ratio of 1,4-bis(aminomethyl)cyclohexane.
[0014] A first aspect of the present invention thus relates to polyamic acids and the like given below.
[0000] [1] A polyamic acid having a repeating unit represented by general formula (1),
[0015] wherein a 1,4-bismethylenecyclohexane skeleton (X) in general formula (1) consists of a trans isomer represented by formula (X1) and a cis isomer represented by formula (X2), and
[0016] a content of the trans isomer is 60% to 100%, and a content of the cis isomer is 0% to 40%, with respect to the total content of the cis and trans isomers being 100%,
[0000]
[0017] where R is a tetravalent group having 4 to 27 carbon atoms, and denotes an aliphatic group, a monocyclic aliphatic group, a condensed polycyclic aliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, a non-condensed polycyclic aliphatic group in which alicyclic groups are mutually bonded to each other either directly or via a crosslinking member, or a non-condensed polycyclic aromatic group in which aromatic groups are mutually bonded to each other either directly or via a crosslinking member.
[0000]
[0000] [2] The polyamic acid according to [1], wherein the content of the trans isomer is 80% to 100%, and the content of the cis isomer is 0% to 20%, with respect to the total content of the cis and trans isomers being 100%.
[0018] [3] The polyamic acid according to [1] or [2], wherein a logarithmic viscosity of the polyamic acid in N-methyl-2-pyrrolidone is 0.1 to 3.0 g/dl, as measured at 35° C. and at a polyamic acid concentration of 0.5 g/dl.
[0000] [4] A polyamic acid varnish including the polyamic acid according to any one of [1] to [3].
[5] A metal clad laminate obtained by laminating together a polyimide film prepared from the polyamic acid varnish according to [4] and a metal foil.
[0019] A second aspect of the present invention relates to polyimides and the like given below.
[0000] [6] A polyimide having a repeating unit represented by general formula (2),
[0020] wherein a 1,4-bismethylenecyclohexane skeleton (X) in general formula (2) consists of a trans isomer represented by formula (X1) and a cis isomer represented by formula (X2), and
[0021] a content of the trans isomer is 60% to 100%, and a content of the cis isomer is 0% to 40%, with respect to the total content of the cis and trans isomers being 100%,
[0000]
[0022] where R is a tetravalent group having 4 to 27 carbon atoms, and denotes an aliphatic group, a monocyclic aliphatic group, a condensed polycyclic aliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, a non-condensed polycyclic aliphatic group in which alicyclic groups are mutually bonded to each other either directly or via a crosslinking member, or a non-condensed polycyclic aromatic group in which aromatic groups are mutually bonded to each other either directly or via a crosslinking member.
[0000]
[0000] [7] The polyimide according to [6], wherein the content of the trans isomer is 80% to 100%, and the content of the cis isomer is 0% to 20%, with respect to the total content of the cis and trans isomers being 100%.
[8] The polyimide according to [6] or [7], wherein a logarithmic viscosity of the polyimide in a 9:1 (weight ratio) mixture solvent of p-chlorophenol and phenol is 0.1 to 3.0 dl/g, as measured at 35° C. and at a polyimide concentration of 0.5 g/dl.
[9] A polyimide film including the polyimide according to any one of [6] to [8].
[10] The polyimide film according to [9], wherein a glass transition temperature is 250° C. or above.
[11] A metal clad laminate obtained by laminating together the polyimide film according to [9] and a metal foil.
[0023] A third aspect of the present invention relates to processes for producing a polyamic acid and the like given below.
[0000] [12] A process for producing the polyamic acid according to [1], including:
[0024] reacting together a trans isomer of 1,4-bis(aminomethyl)cyclohexane represented by formula (Y1), a cis isomer of 4-bis(aminomethyl)cyclohexane represented by formula (Y2), and a tetracarboxylic dianhydride represented by formula (3),
[0025] wherein a content of the trans isomer represented by formula (Y1) is 60% to 100%, and a content of the cis isomer represented by formula (Y2) is 0% to 40%, with respect to the total content of the cis and trans isomers being 100%,
[0000]
[0026] where R is a tetravalent group having 4 to 27 carbon atoms, and denotes an aliphatic group, a monocyclic aliphatic group, a condensed polycyclic aliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, a non-condensed polycyclic aliphatic group in which alicyclic groups are mutually bonded to each other either directly or via a crosslinking member, or a non-condensed polycyclic aromatic group in which aromatic groups are mutually bonded to each other either directly or via a crosslinking member.
[0000] [13] The process according to [12], wherein the content of the trans isomer represented by formula (Y1) is 80% to 100%, and the content of the cis isomer represented by formula (Y2) is 0% to 20%, with respect to the total content of the cis and trans isomers being 100%.
[14] A process for producing a polyimide including:
[0027] thermally or chemically imidizing a polyamic acid obtained in [12] or [13].
[0028] A fourth aspect of the present invention relates to a display substrate material and the like containing polyimide.
[0000] [15] A polyimide resin composition including:
[0029] the polyimide according to any one of [6] to [8]; and
[0030] a coloring agent.
[0000] [16] The polyimide resin composition according to [15], wherein the coloring agent is a whitening agent.
[17] The polyimide resin composition according to [16], wherein the whitening agent is titanium oxide.
[18] A polyamic acid composition including:
[0031] the polyamic acid according to any one of [1] to [3]; and
[0032] a coloring agent.
[0000] [19] The polyamic acid composition according to [18], wherein the coloring agent is a whitening agent.
[20] The polyamic acid composition according to [19], wherein the whitening agent is titanium oxide.
[21] A display substrate material including the polyimide according to any one of [6] to [8] or the polyimide resin composition according to any one of [15] to [17].
[22] A circuit board material including the polyimide according to any one of [6] to [8] or the polyimide resin composition according to any one of [15] to [17].
[23] A coating material including the polyimide according to any one of [6] to [8] or the polyimide resin composition according to any one of [15] to [17].
[24] A light reflector including the polyimide resin composition according to [16] or [17] as a light reflecting material.
Advantageous Effects of Invention
[0033] The present invention is a technology that may significantly increases the glass transition temperature of polyimide resin without impairing its inherent properties. For example, by controlling the geometric isomerism of a monomeric unit of the polyimide, it is possible to increase the glass transition temperature of the polyimide resin without triggering possible molecular weight reduction caused by introduction of a reactive terminal group to the polyimide. The present invention thus provides a polyimide resin having higher heat resistance than conventional ones. The polyimide resin is suitable for coating materials, display materials for displays, and circuit board materials, for example.
DESCRIPTION OF EMBODIMENTS
[0034] 1. Polyamic Acid
[0035] A polyamic acid of the present invention has a repeating unit represented by the general formula (1) below. Specifically, the polyamic acid has a repeating unit having a diamine unit derived from 1,4-bis(aminomethyl)cyclohexane.
[0000]
[0036] The unit derived from 1,4-bis(aminomethyl)cyclohexane is composed of an aliphatic compound. Accordingly, the polyamic acid of the present invention may exhibit high transparency to UV light and visible light compared to a polyamic acid having an aromatic compound as a diamine unit.
[0037] The unit (X) derived from 1,4-bis(aminomethyl)cyclohexane constituting the polyamic acid of the present invention may exist as one of the two geometric isomers (cis-trans isomers) shown below. The trans isomer unit is represented by formula (X1), and the cis isomer unit is represented by formula (X2).
[0000]
[0038] The cis/trans ratio of the unit derived from 1,4-bis(aminomethyl)cyclohexane is preferably 40/60 to 0/100, more preferably 20/80 to 0/100. The glass transition temperature of the polyimide prepared from the polyamic acid of the present invention can be controlled by changing the cis/trans ratio of the diamine unit derived from 1,4-bis(aminomethyl)cyclohexane. Namely, as the ratio of trans isomer (X1) increases, so too does the glass transition temperature, i.e., heat resistance, of the resultant polyimide.
[0039] The cis/trans ratio of the diamine unit derived from 1,4-bis(aminomethyl)cyclohexane, which is contained in the polyamic acid, can be measured by NMR.
[0040] The above cis/trans ratio can be adjusted by changing the cis/trans ratio of 1,4-bis(aminomethyl)cyclohexane, a raw monomer material of a polyamic acid. Namely, 1,4-bis(aminomethyl)cyclohexane yields a polyamic acid by reaction with an acid dianhydride while retaining its geometric isomerism.
[0041] As a diamine unit of the polyamic acid, a unit derived from a diamine other than 1,4-bis(aminomethyl)cyclohexane may be contained. By way of example, a 1,4-bis(aminomethyl)cyclohexane-derived diamine unit and one or more other diamine units may be randomly distributed in the polyamic acid. It should be noted, however, that the 1,4-bis(aminomethyl)cyclohexane-derived diamine unit preferably accounts for 10 to 100 mol % of the total diamine unit in the polyamic acid.
[0042] There are no particular limitations on diamines other than 1,4-bis(aminomethyl)cyclohexane (other diamines) as long as a polyamic acid or polyimide can be prepared.
[0043] The first examples of other diamines are diamines having benzene ring(s). Examples of diamines having benzene ring(s) include:
[0044] <1> diamines having one benzene ring, such as p-phenylenediamine, m-phenylenediamine, p-xylylenediamine, and m-xylylenediamine;
[0045] <2> diamines having two benzene rings, such as 3,3′-diaminodiphenylether, 3,4′-diaminodiphenylether, 4,4′-diaminodiphenylether, 3,3′-diaminodiphenylsulfide, 3,4′-diaminodiphenylsulfide, 4,4′-di amino diphenyl sulfide, 3,3′-diaminodiphenylsulfone, 3,4′-diaminodiphenylsulfone, 4,4′-diaminodiphenylsulfone, 3,3′-diaminobenzophenone, 4,4′-diaminobenzophenone, 3,4′-diaminobenzophenone, 3,3′-diaminodiphenylmethane, 4,4′-di aminodiphenylmethane, 3,4′-diaminodiphenylmethane, 2,2-di(3-aminophenyl)propane, 2,2-di(4-aminophenyl)propane, 2-(3-aminophenyl)-2-(4-aminophenyl)propane, 2,2-di(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-di(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2-(3-aminophenyl)-2-(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 1,1-di(3-aminophenyl)-1-phenylethane, 1,1-di(4-aminophenyl)-1-phenylethane, and 1-(3-aminophenyl)-1-(4-aminophenyl)-1-phenylethane;
[0046] <3> diamines having three benzene rings, such as 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(3-aminobenzoyl)benzene, 1,3-bis(4-aminobenzoyl)benzene, 1,4-bis(3-aminobenzoyl)benzene, 1,4-bis(4-aminobenzoyl)benzene, 1,3-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(4-amino-α,α-dimethylbenzyl)benzene, 1,4-bis(3-amino-α,α-dimethylbenzyl)benzene, 1,4-bis(4-amino-α,α-dimethylbenzyl)benzene, 1,3-bis(3-amino-α,α-ditrifluoromethylbenzyl)benzene, 1,3-bis(4-amino-α,α-ditrifluoromethylbenzyl)benzene, 1,4-bis(3-amino-α,α-ditrifluoromethylbenzyl)benzene, 1,4-bis(4-amino-α,α-ditrifluoromethylbenzyl)benzene, 2,6-bis(3-aminophenoxy)benzonitrile, and 2,6-bis(3-aminophenoxy)pyridine;
[0047] <4> diamines having four benzene rings, such as 4,4′-bis(3-aminophenoxy)biphenyl, 4,4′-bis(4-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, and 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane;
[0048] <5> diamines having five benzene rings, such as 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(4-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(4-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(3-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene, 1,4-bis[4-(3-aminophenoxy)-α,α-dimethylbenzyl]benzene, and 1,4-bis[4-(4-aminophenoxy)-α,α-dimethylbenzyl]benzene; and
[0049] <6> diamines having six benzene rings, such as 4,4′-bis[4-(4-aminophenoxy)benzoyl]diphenylether, 4,4′-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone, 4,4′-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenylsulfone, and 4,4′-bis[4-(4-aminophenoxy)phenoxy]diphenylsulfone.
[0050] The second examples of other diamines include diamines having aromatic substituent(s), such as 3,3′-diamino-4,4′-diphenoxybenzophenone, 3,3′-diamino-4,4′-dibiphenoxybenzophenone, 3,3′-diamino-4-phenoxybenzophenone, and 3,3′-diamino-4-biphenoxybenzophenone.
[0051] The third examples of other diamines include diamines having a spirobiindan ring, such as 6,6′-bis(3-aminophenoxy)-3,3,3′,3′-tetramethyl-1,1′-spirobiindan, and 6,6′-bis(4-aminophenoxy)-3,3,3′,3′-tetramethyl-1,1′spirobiindan.
[0052] The fourth examples of other diamines include siloxane diamines, such as 1,3-bis(3-aminopropyl)tetramethyldisiloxane, 1,3-bis(4-aminobutyl)tetramethyldisiloxane, α,ω-bis(3-aminopropyl)polydimethylsiloxane, and α,ω-bis(3-aminobutyl)polydimethylsiloxane.
[0053] The fifth examples of other diamines include ethylene glycol diamines, such as bis(aminomethyl)ether, bis(2-aminoethyl)ether, bis(3-aminopropyl)ether, bis[2-(2-aminomethoxy)ethyl]ether, bis[2-(2-aminoethoxy)ethyl]ether, bis[2-(3-aminoprotoxy)ethyl]ether, 1,2-bis(aminomethoxy)ethane, 1,2-bis(2-aminoethoxy)ethane, 1,2-bis[2-(aminomethoxy)ethoxy]ethane, 1,2-bis[2-(2-aminoethoxy)ethoxy]ethane, ethylene glycol bis(3-aminopropyl)ether, diethylene glycol bis(3-aminopropyl)ether, and triethylene glycol bis(3-aminopropyl)ether.
[0054] The sixth examples of other diamines include alkylenediamines, such as ethylenediamine, 1,3-diaminopropane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,7-diaminoheptane, 1,8-diaminooctane, 1,9-diaminononane, 1,10-diaminodecane, 1,11-diaminoundecane, and 1,12-diaminododecane.
[0055] The seventh examples of other diamines include alicyclic diamines, such as cyclobutanediamine, cyclohexanediamine, di(aminomethyl)cyclohexane [or bis(aminomethyl)cyclohexanes (except for 1,4-bis(aminomethyl)cyclohexane)], diaminobicycloheptane, diaminomethylbicycloheptane (including norbornanediamines, such as norbornanediamine), diaminooxybicycloheptane, diaminomethyloxybicycloheptane (including oxanorbornanediamine), isophoronediamine, diaminotricyclodecane, diaminomethyltricyclodecane, bis(aminocyclohexyl)methane [or methylenebis(cyclohexylamine)], and bis(aminocyclohexyl)isopropylidene.
[0056] There are no particular limitations on the tetracarboxylic acid unit that constitutes the polyamic acid of the present invention. Namely, substituent R in general formula (1) may be a tetravalent organic group having 4 to 27 carbon atoms. Substituent R may be an aliphatic group, a monocyclic aliphatic group, a condensed polycyclic aliphatic group, a monocyclic aromatic group, or a condensed polycyclic aromatic group. Alternatively, substituent R may be a non-condensed polycyclic aliphatic group in which alicyclic groups are mutually bonded to each other either directly or via a crosslinking member, or a non-condensed polycyclic aromatic group in which aromatic groups are mutually bonded to each other either directly or via a crosslinking member.
[0057] Substituent R in general formula (1) is a group derived from a tetracarboxylic dianhydride, a raw material of the polyamic acid or polyimide of the present invention. There are no particular limitations on the tetracarboxylic dianhydride as long as the polyamic acid or polyimide can be prepared. The tetracarboxylic dianhydride may be an aromatic tetracarboxylic dianhydride or alicyclic tetracarboxylic dianhydride, for example.
[0058] Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride, 3,3′,4,4′-benzophenonetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, bis(3,4-dicarboxyphenyl)sulfide dianhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydrde, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 4,4′-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, 2,2-bis[(3,4-dicarboxyphenoxy)phenyl]propane dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride 2,2′,3,3′-benzophenonetetracarboxylic dianhydride, 2,2′,3,3′-biphenyltetracarboxylic dianhydride, 2,2-bis(2,3-dicarboxyphenyl)propane dianhydride, 2,2-bis(2,3-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, bis(2,3-dicarboxyphenyl)ether dianhydride, bis(2,3-dicarboxyphenyl)sulfide dianhydride, bis(2,3-dicarboxyphenyl)sulfone dianhydride, 1,3-bis(2,3-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(2,3-dicarboxyphenoxy)benzene dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,3-bis(3,4-dicarboxybenzoyl)benzene dianhydride, 1,4-bis(3,4-dicarboxybenzoyl)benzene dianhydride, 1,3-bis(2,3-dicarboxybenzoyl)benzene dianhydride, 1,4-bis(2,3-dicarboxybenzoyl)benzene dianhydride, 4,4′-isophthaloyldiphthalic anhydride, diazodiphenylmethane-3,3′,4,4′-tetracarboxylic dianhydride, diazodiphenylmethane-2,2′,3,3′-tetracarboxylic dianhydride, 2,3,6,7-thioxanthonetetracarboxylic dianhydride, 2,3,6,7-anthraquinonetetracarboxylic dianhydride, 2,3,6,7-xanthonetetracarboxylic dianhydride, and ethylenetetracarboxylic dianhydride.
[0059] Examples of alicyclic tetracarboxylic dianhydrides include cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, bicyclo[2.2.1]heptane-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]octo-7-ene-2,3,5,6-tetracarboxylic dianhydride, bicyclo[2.2.2]octane-2,3,5,6-tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic dianhydride, bicyclo[2.2.1]heptane-2,3,5-tricarboxylic-6-acetic dianhydride, 1-methyl-3-ethylcyclohexa-1-ene-3-(1,2),5,6-tetracarboxylic dianhydride, decahydro-1,4,5,8-dimethanonapthalene-2,3,6,7-tetracarboxylic dianhydride, 4-(2,5-dioxotetrahydrofuran-3-yl)-tetralin-1,2-dicarboxylic dianhydride, and 3,3′,4,4′-dicyclohexyltetracarboxylic dianhydride.
[0060] When the tetracarboxylic dianhydride has an aromatic ring such as benzene ring, some or all of the hydrogen atoms on the aromatic ring may be substituted by a substituent selected from fluoro group, methyl group, methoxy group, trifluoromethyl group, and trifluoromethoxy group. Furthermore, when the tetracarboxylic dianhydride has an aromatic ring such as a benzene ring, depending on the purpose, some or all of the hydrogen atoms on the aromatic ring, may be substituted by a substituent serving as a crosslinking site, selected from ethynyl group, benzocyclobutene-4′-yl group, vinyl group, allyl group, cyano group, isocyanate group, nitrile group, and isopropenyl group. In addition, depending on the purpose, a group serving as a crosslinking site, such as vinylene group, vinylidene group and/or ethynylidene group, may be incorporated into the main chain skeleton of the tetracarboxylic dianhydride, preferably in an amount that does not impair moldability.
[0061] Some of the tetracarboxylic dianhydride units may be derived from hexacarboxylic trianhydrides and/or octacarboxylic tetraanhydrides in order to introduce branches to the polyamic acid or polyimide.
[0062] The above tetracarboxylic dianhydrides may be used alone or in combination.
[0063] Furthermore, substituent R in general formula (1) may be represented by one of the following formulas (R1) to (R4):
[0000]
[0000] where —Y— represents a single bond, —CO—, —O—, —SO 2 —, —S—, —CH 2 —, —C(CH 3 ) 2 —, —CF 2 —, —C(CF 3 ) 2 —, —O-Ph-O—, or —O-Ph-C(CH 3 ) 2 -Ph-O—.
[0064] The structure of substituent R can be determined according to the desired characteristics of a polyimide film to be produced. Appropriate selection of substituent R not only results in increased steric stability in the molded polyimide film, but also may allow for arbitrary control of film characteristics, such as thermal coefficient, dimension stability, mechanical strength, flexibility, and adhesion.
[0065] Thus, it is preferable to select substituent R according to the intended use of the polyamic acid or polyimide. The repeating unit represented by general formula (1) may have one substituent R, or may have two more different substituents R. For example, two or more different Rs may be randomly distributed in the polyamic acid.
[0066] In addition to the repeating unit represented by general formula (1), the polyamic acid of the present invention may have one or more other repeating units as long as the effects of the present invention are not impaired.
[0067] The polyamic acid of the present invention may be a blend of two or more different polyamic acids having different monomeric unit sets. All of the blended polyamic acids may be a polyamic acid having the repeating unit represented by general formula (1); only one of them are a polyamic acid having the repeating unit represented by general formula (1), and the others are a polyamic acid which does not have the repeating unit represented by general formula (1); and so forth.
[0068] The logarithmic viscosity of a solution of the polyamic acid of the present invention in N-methyl-2-pyrrolidone (concentration: 0.5 g/dl) is preferably 0.1 to 3.0 dl/g at 35° C. This is because application of the polyamic acid solution becomes easy.
[0069] The polyamic acid of the present invention can be used in a variety of applications; it can be used as a varnish component. A varnish contains the polyamic acid of the present invention and a solvent. There are no particular limitations on the concentration of the polyamic acid. Solvent removal by means of drying becomes easy at higher concentrations, and therefore, the polyamic acid concentration may be, for example, 15 wt % or higher. Application of a varnish becomes difficult at extreme concentrations, and therefore, the polyamic acid concentration may be, for example, 50 wt % or less.
[0070] A varnish containing the polyamic acid of the present invention can be applied onto a metal foil to manufacture a metal clad laminate. For example, when a coat of a varnish containing the polyamic acid of the present invention is formed on a copper or copper alloy foil, it can be used a metal clad laminate for circuit boards. Since the glass transition temperature of polyimide prepared from the polyamic acid of the present invention is high, the metal clad laminate may exhibit high heat resistance when used as a circuit board.
[0071] 2. Production Process for Polyamic Acid
[0072] The polyamic acid of the present invention is prepared by reaction (polymerization) of a diamine component including 1,4-bis(aminomethyl)cyclohexane with a tetracarboxylic dianhydride.
[0073] 1,4-bis(aminomethyl)cyclohexane contained in a diamine used as a raw material may have trans isomer (Y1) and cis isomer (Y2) represented by the following formulas, respectively. The cis/trans ratio of the raw material 1,4-bis(aminomethyl)cyclohexane is preferably 40/60 to 0/100, more preferably 20/80 to 0/100. The ratio of cis isomer (Y2) to trans isomer (Y1) in the raw material is consistent with the cis isomer (Y2)/trans isomer (Y1) ratio in the repeating unit of the resultant polyamic acid.
[0000]
[0074] A tetracarboxylic dianhydride used as a raw material is represented by the following formula (3):
[0000]
[0075] where R is defined the same as in general formula (1).
[0076] When the number of moles of a diamine contained in the raw material is defined as X and the number of moles of a tetracarboxylic dianhydride contained in the raw material is defined as Y, the ratio Y/X is preferably 0.9 to 1.1, more preferably 0.95 to 1.05, further preferably 0.97 to 1.03, most preferably 0.99 to 1.01.
[0077] The polyamic acid of the present invention can be prepared by, for example, copolymerization of a diamine containing 1,4-bis(aminomethyl)cyclohexane with a tetracarboxylic dianhydride in an aprotic polar solvent or a water-soluble alcohol solvent. Examples of aprotic polar solvents include N-methylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide and hexamethylphosphoramide; and ether compounds such as 2-methoxyethanol, 2-ethoxyethanol, 2-(methoxymethoxy)ethoxyethanol, 2-isopropoxyethanol, 2-butoxyethanol, tetrahydrofurfurylalcohol, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monoethyl ether, tetraethylene glycol, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether, polyethylene glycol, polypropylene glycol, tetrahydrofuran, dioxane, 1,2-dimethoxyethane, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether. Examples of water-soluble alcohol solvents include methanol, ethanol, 1-propanol, 2-propanol, tert-butylalcohol, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 2-butene-1,4-diol, 2-methyl-2,4-pentanediol, 1,2,6-hexanetriol, and diacetonealcohol.
[0078] These solvents can be used alone or in combination. Preferred examples include N,N-dimethylacetamide, N-methylpyrrolidone, and a combination thereof.
[0079] There are no particular limitations on the polymerization procedure. For example, a vessel equipped with a stirrer and a nitrogen inlet is prepared. The vessel is purged with nitrogen and charged with the above solvent. A diamine is then added such that a polyimide solution has a solid content of 30 wt %, followed by temperature adjustment and stirring for dissolution. An equimolar amount of a tetracarboxylic dianhydride with respect to the diamine is added to the solution, followed by temperature adjustment and stirring for 1 to 50 hours to yield a polyamic acid.
[0080] 3. Polyimide
[0081] A polyimide of the present invention has a repeating unit represented by the following general formula (2). Specifically, the polyimide has a repeating unit in which the diamine unit is derived from 1,4-bis(aminomethyl)cyclohexane.
[0000]
[0082] Substituent R in general formula (2) is the same as substituent R in general formula (1).
[0083] As with the polyamic acid described above, unit (X) derived from 1,4-bis(aminomethyl)cyclohexane in the polyimide of the present invention may exist as one of the two geometric isomers (cis-trans isomers) shown below. The trans isomer unit is represented by formula (X1), and the cis isomer unit is represented by formula (X2).
[0000]
[0084] The cis (X2)/trans (X1) ratio of the unit derived from 1,4-bis(aminomethyl)cyclohexane is preferably 40/60 to 0/100, more preferably 20/80 to 0/100, in order to increase the glass transition temperature of the polyimide. For example, the glass transition temperature of the polyimide of the present invention is preferably 250° C. or above. Glass transition temperature may be adjusted by, for example, appropriately changing the cis (X2)/trans (X1) ratio and the structure of substituent R in general formula (2).
[0085] The logarithmic viscosity of a solution of the polyimide of the present invention in a 9:1 (weight ratio) mixture solvent of p-chlorophenol and phenol (concentration: 0.5 g/dl) is preferably 0.1 to 3.0 dl/g at 35° C. Within this range the polyimide has a practical molecular weight, and the solution having a desired solid content can be readily applied. When the logarithmic viscosity is too high, degree of polymerization is generally too high, and moreover, solubility may decrease.
[0086] The polyimide of the present invention can be prepared by imidization (imide ring closure) of the polyamic acid described above. In particular, a coat of the polyamic acid varnish described above can be heated and dried to produce a polyimide film. By way of example, a polyimide film is formed as follows: after applying a polyamic acid varnish to a metal or glass substrate to a dried polyimide film thickness of the order of 0.1 μm to 1 mm, the varnish is heated for 1 second to 10 hours at 20° C. to 400° C., preferably 150° C. to 350° C., further preferably 200° C. to 300° C., and dried to effect condensation. Thereafter, the polyimide film is peeled off from the substrate, or the substrate is dissolved away.
[0087] There are no particular limitations on the method of applying the polyimide varnish of the present invention; any known coater, such as die coater, comma coater, roll coater, gravure coater, curtain coater, spray coater, or lip coater, can be employed.
[0088] 4. Polyimide Resin Composition
[0089] Where necessary, various additives may be added to the polyimide of the present invention to produce a polyimide resin composition. Examples of additives include fillers, wear resistance improvers, flame retardancy improvers, tracking resistance improvers, thermal conductivity improvers, antifoaming agents, levelling agents, surface tension modifiers, and coloring agents. For its high transparency, the polyimide of the present invention can be easily colored by a coloring agent. Moreover, for its high bend resistance, it is less likely to become brittle even when a coloring agent is added abundantly.
[0090] The coloring agent may be organic or inorganic, or may be a fluorescent pigment. There are no particular limitations on the color of the coloring agent; color can be appropriately determined depending on the intended use. For example, when the polyimide of the present invention is used as a light reflecting material, light beam reflectivity can be enhanced by the addition of a whitening agent such as white inorganic filler or fluorescent brightener.
[0091] Examples of white inorganic fillers include metal oxides such as titanium oxide, zinc oxide, magnesium oxide, alumina, and silica; inorganic metal salts such as calcium carbonate, magnesium carbonate, barium sulfate, calcium sulfate, magnesium sulfate, aluminum sulfate, magnesium chloride, and basic magnesium carbonate; metal hydroxides such as magnesium hydroxide, aluminum hydroxide, and calcium hydroxide; and clay-based minerals such as talc, mica, and caoline, with titanium oxide and zinc oxide being preferable.
[0092] There are no particular limitations on the shape of white inorganic filler particles; they may be acicular, plate-like, or spherical. The average particle diameter of the white inorganic filler is preferably 0.05 to 15 μm, more preferably 0.1 to 10 μm.
[0093] The white inorganic filler is preferably added in an amount of 10 to 500 parts by weight, more preferably 20 to 400 parts by weight, per 100 parts by weight of polyimide resin. Within these ranges, sufficient light beam reflectivity can be achieved for the resultant polyimide film and film strength is less likely to drop.
[0094] Such a polyimide resin composition can be suitably prepared by mixing the polyamic acid of the present invention with additives such as white inorganic filler to produce a polyamic acid composition, and imidizing the polyamic acid composition.
[0095] 5. Applications
[0096] Since the polyimide of the present invention has excellent heat resistance and folding endurance as described above, the polyimide may be suitably used as a substrate material for circuit boards (polyimide-metal laminates).
[0097] That is, a polyimide-metal laminate can be prepared by applying on a metal foil a varnish containing the polyamic acid of the present invention, followed by drying and imidization.
[0098] Alternatively, a metal clad laminate can be produced by laminating the polyimide film of the present invention on a metal foil. Lamination may be effected by thermal compression bonding. Thermal compression bonding is preferably performed at a temperature equal to or higher than the glass transition temperature of the polyimide film. Examples of thermal compression bonding devices include hot press machines and heat laminators. There are no particular limitations on the lamination method; however, nip roll lamination is preferable.
[0099] After or during lamination, the metal clad laminate is further retained at 150° C. to 400° C., whereby a metal clad laminate can be obtained in which good adhesion is ensured between the metal foil and polyimide film.
[0100] As a heater, a typical furnace or autoclave may be employed, for example. Heating atmosphere may be air or inert gas (e.g., nitrogen or argon gas) atmosphere. Heating may be effected by, for example, continuous heating or allowing the metal clad laminate to stand in a furnace while being wound around a core. Heating methods include conduction heating, infrared heating, and a combination thereof. Heating period is, for example, around 0.05 to 5,000 minutes.
[0101] Examples of metal foils used for the metal clad laminate include metal foils made of copper, nickel, cobalt, chrome, zinc, aluminum, stainless steel or an alloy thereof. Among them, copper and copper alloy, stainless steel and its alloy, nickel and nickel alloy (including 42 alloy), and aluminum and aluminum alloy are preferable.
[0102] The polyimide film to be bonded to a metal foil by thermal compression bonding may be an insulating base film on which a layer of the polyimide resin of the present invention has been previously formed. The insulating base film is preferably flexible.
[0103] The material of the flexible insulating base film may be polyimide, polybenzimidazole, polybenzoxazole, polyamide (including aramide), polyetherimide, polyamideimide, polyester (including liquid crystal polyester), polysulfone, polyethersulfone, polyetherketone, or polyetheretherketone, with polyimide, polybenzimidazole, polyamide (including aramide), polyetherimide, polyamideimide, and polyethersulfone being preferable, for example. There are no particular limitations on the thickness of the flexible insulating base film; however, it is preferably 3 to 150 μm.
[0104] The metal layer is not limited to a metal foil, and may be a metal layer formed by means of sputtering, vapor deposition or other gas phase method or by electroplating such as electroless plating. The metal layer is formed onto a polyimide film of the present invention or onto a polyimide resin layer formed on an insulating base film.
[0105] Vapor deposition methods include, in addition to general vapor deposition, CVD and ion-plating. When forming a metal layer by vapor deposition, the surface of a polyimide resin layer on which the metal layer is to be formed may be subjected to pre-treatment such as alkaline reagent treatment, plasma treatment, or sand blast treatment.
[0106] In addition to usage as a circuit board material described above, the polyimide of the present invention is used in various applications where heat resistance and transparency, and folding endurance are required, including display substrate material for displays, (transparent) coating material used for coating display screens or well-designed molded articles, and light reflecting or light shielding material colored by an coloring agent (e.g., inorganic pigment or organic dye). Among other applications, the polyimide of the present invention can be used as a light reflecting material for liquid crystal displays, preferably as a light reflecting material for LED backlight units.
[0107] Such light reflecting material is prepared from a polyimide resin composition which contains the polyimide of the present invention and a whitening agent such as white inorganic filler. On a surface of light reflecting material, which is not the light reflecting surface, may be provided with additional layer(s) so as to manufacture a light reflector. Specific examples, particle shape and formulation amount of the white inorganic filler are the same as described above.
[0108] The light reflecting material preferably has light reflectivity of 50% or more at 550 nm wavelength. Light reflectivity can be measured with Hitachi U-3010 spectrophotometer (Hitachi High-Technologies Corporation). Specifically, light reflectivity is measured over the range from 300 nm to 800 nm, and a value of light reflectivity measured at 550 nm is employed as a representative value.
[0109] The thickness of light reflecting material is preferably 5 to 200 μm, more preferably 10 to 100 μm.
EXAMPLES
[0110] Hereinafter, the present invention will be described in detail with reference to Examples, which however shall not be construed as limiting the scope the invention thereto.
[0111] The following describes test methods used to test samples prepared in Examples and Comparative Examples.
1) Intrinsic Logarithmic Viscosity (η) of Polyamic Acid
[0112] A polyamic acid is dissolved in N,N-dimethylacetamide (DMAc) to a solid content of 0.5 g/dl to produce a polyamic acid solution. The viscosity of the polyamic acid solution is measured at 35° C. using a Ubbelohde viscometer.
[0113] 2) Glass Transition Temperature (Tg) and Coefficient of Thermal Linear Expansion (CTE)
[0114] Measurements are made using TMA-50 manufactured by Shimadzu Co. in a nitrogen stream at a heating rate of 10° C./minute and at a load per unit sectional area of 14 g/mm 2 . The coefficient of thermal linear expansion is measured at 100° C. to 200° C.
[0115] 3) Total Light Transmittance
[0116] Measurement is made with HZ-2 (TM double beam system) manufactured by Suga Test Instruments Co., Ltd. at an opening size of Φ20 mm with a D65 light source.
[0117] 4) Evaluation of Folding Endurance
[0118] Using the following tester, samples are evaluated for their folding endurance under the following test condition.
[0119] Tester: MIT folding endurance tester
[0120] Tension: 1.0 kg or 0.5 kg
[0121] Folding angle: 135° (on either side)
[0122] Folding rate: 175 double folds per minute
[0123] Curvature radius: 0.38 mm
[0124] Clamp gap: 0.3 mm
[0125] Test piece dimension: 120 mm length×15 mm width
[0126] 5) Calculation of Cis/Trans Ratio of 14BAC
[0127] 1 H NMR measurements (solvent: CDCl 3 ) are made on various purified or unpurified 14BACs. Based on the signal intensity ratio over a predetermined magnetic field range, the cis/trans ratio is found. Specifically, the cis-trans ratio is calculated based on the ratio of cis isomer-derived NH 2 CH 2 (2.607 ppm, doublet) to trans isomer-derived NH 2 CH 2 (2.533 ppm, doublet).
[0128] 6) Tensile Modulus of Elasticity
[0129] Dumbbell-shaped test pieces punched out with a punching machine are measured for their tensile modulus of elasticity using a tensile tester (EZ-S, Shimadzu Corporation) under the following condition: gauge length=5 mm, tension rate=30 mm/min. An average of 10 measured values for the integrated area under a stress-strain curve from the origin to rupture is employed as tensile modulus of elasticity.
[0130] <Synthesis of Polyamic Acid and Production of Polyimide Film>
Example 1
[0131] 15.7 g (0.110 mol) of 1,4-bis(aminomethyl)cyclohexane (14BAC) and as an organic solvent 192 g of N,N-dimethylacetamide (DMAc) are charged into a 300 mL five-neck separable flask equipped with a thermometer, a stirrer, a nitrogen inlet and a dropping funnel, and stirred. The cis/trans ratio of 1,4-bis(aminomethyl)cyclohexane is 9/91.
[0132] The flask is charged with 32.4 g (0.110 mol) of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and placed in a 120° C. oil bath for 5 minutes. Salting out occurs about 3 minutes after addition of BPDA, immediately after which the salt is observed to be re-dissolved in the solvent. After removing the oil bath, the solution is stirred for a further 18 hours at room temperature to yield a solution containing a polyamic acid (polyimide precursor polymer), i.e., a polyimide precursor polymer varnish. The resultant polyamic acid has an intrinsic logarithmic viscosity of 0.94 dl/g (35° C., 0.5 g/dl).
[0133] The polyamic acid solution is spread over a glass substrate using a doctor blade. The glass substrate is placed in an oven. In a nitrogen gas stream, the glass substrate is heated from 50° C. to 250° C. over 2 hours, and heated at 250° C. for a further 2 hours to produce a colorless, transparent self-supporting polyimide film with 20 μm thickness. The polyimide film has a glass transition temperature (Tg) of 267° C. and a coefficient of thermal linear expansion of 41 ppm/K. The results are shown in Table 1.
Example 2
[0134] 118 g (0.400 mol) of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) and as an organic solvent 290 g of N,N-dimethylacetamide (DMAc) are charged into a 1 L five-neck separable flask equipped with a thermometer, a stirrer, a nitrogen inlet and a dropping funne, and stirred in a 0° C. ice bath to produce a slurry-like liquid. 56.9 g (0.400 mol) of 1,4-bis(aminomethyl)cyclohexane (14BAC) and 117 g of N,N-dimethylacetamide (DMAc) loaded in the dropping funnel are added dropwise to the solution over 2 hours. The cis/trans ratio of 1,4-bis(aminomethyl)cyclohexane is 9/91.
[0135] After addition, the solution is stirred for a further 16 hours at room temperature to yield a polyimide precursor polymer varnish. The resultant polyamic acid has a logarithmic viscosity of 0.73 dL/g (35° C., 0.5 g/dl). A polyimide film is prepared as in Example 1. Test results are shown in Table 1.
Examples 3 to 5 and Comparative Examples 1 and 2
[0136] Polyamic acids of Examples 3 to 5 and Comparative Examples 1 to 2 are prepared as in Example 1 while changing the cis/trans ratio of 1,4-bis(aminomethyl)cyclohexane in accordance with Table 1. Polyimide films are then produced as in Example 1. Test results are also shown in Table 1.
[0000]
TABLE 1
Total
Tensile
MIT folding
light
Modulus
endurance
14BAC
transmit-
of
(Number of
Acid
cis/trans
η
T g
CTE
tance
Elasticity
double folds
dianhydride
ratio
(dL/g)
(° C.)
(ppm/K)
(%)
(GPa)
until failure)
Ex. 1
BPDA
9/91
0.94
267
41
88
2.64
>100,000
@ 1.0 kg tension
Ex. 2
BPDA
9/91
0.73
258
45
88
2.42
>100,000
@ 1.0 kg tension
Ex. 3
BPDA
11/89
0.97
266
44
88
2.56
>100,000
@ 1.0 kg tension
Ex. 4
BPDA
19/81
0.83
262
41
88
2.85
>100,000
@ 1.0 kg tension
Ex. 5
BPDA
37/63
0.76
253
43
88
2.96
>100,000
@ 1.0 kg tension
Comp.
BPDA
60/40
0.99
245
43
88
2.80
>100,000
Ex. 1
@ 1.0 kg tension
Comp.
BPDA
63/37
0.95
241
45
88
2.99
>100,000
Ex. 2
@ 1.0 kg tension
[0137] Examples 1 to 5, where 14BAC having a trans isomer content of greater than 60% is used, all produced a polyimide having a glass transition temperature of greater than 250° C. By contrast, Comparative Examples 1 and 2, where 14BAC having a lower trans isomer content is used, produced a polyimide having a glass transition temperature of less than 250° C.
Example 6
[0138] A polyamic acid is prepared as in Example 1 except that 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) is used instead of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA).
Comparative Example 3
[0139] A polyamic acid is prepared as in Example 6 except that the cis/trans ratio of 1,4-bis(aminomethyl)cyclohexane is changed to 60/40.
Example 7
[0140] A polyamic acid is prepared as in Example 1 except that 3,3′,4,4′-diphenylsulfonetetracarboxylic dianhydride (DSDA) is used instead of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA).
Comparative Example 4
[0141] A polyamic acid is prepared as in Example 7 except that the cis/trans ratio of 1,4-bis(aminomethyl)cyclohexane is changed to 60/40.
Example 8
[0142] A polyamic acid is prepared as in Example 1 except that oxydiphthalic anhydride (ODPA) is used instead of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA).
Comparative Example 5
[0143] A polyamic acid is prepared as in Example 8 except that the cis/trans ratio of 1,4-bis(aminomethyl)cyclohexane is changed to 60/40.
[0144] The above-described tests are conducted with the polyamic acids prepared in Examples 6 to 8 and Comparative Examples 3 and 5 as varnishes. Test results are shown in Table 2.
[0000]
TABLE 2
Total
Tensile
MIT folding
light
Modulus
endurance
14BAC
transmit-
of
(Number of
Acid
cis/trans
η
T g
CTE
tance
Elasticity
double folds
dianhydride
ratio
(dL/g)
(° C.)
(ppm/K)
(%)
(GPa)
until failure)
Ex. 6
BTDA
9/91
1.02
236
52
82
2.95
7,400
@0.5 kg tension
Ex. 7
DSDA
9/91
0.21
273
48
89
2.93
15,300
@0.5 kg tension
Ex. 8
ODPA
9/91
0.87
228
55
89
2.77
>100,000
@0.5 kg tension
Comp.
BTDA
60/40
0.91
227
46
77
2.81
6,600
Ex. 3
@0.5 kg tension
Comp.
DSDA
60/40
0.32
254
47
89
3.04
4,100
Ex. 4
@0.5 kg tension
Comp.
ODPA
60/40
0.81
209
55
89
2.89
51,700
Ex. 5
@0.5 kg tension
[0145] When comparing Example 6 to Comparative Example 3, Example 7 to Comparative Example 4, and Example 8 to Comparative Example 5, values of glass transition temperature in Examples are high compared to those in Comparative Examples in spite of the fact that the same acid dianhydride is used. This is considered to be derived from the difference in the cis/trans ratio of 1,4-bis(aminomethyl)cyclohexane between Example and Comparative Example (Examples 6 to 8 are richer in trans isomer than Comparative Examples 3 to 5, respectively). Moreover, Examples 6 to 8 exhibit superior folding endurance compared to Comparative Examples 3 to 5. It can be thus seen that higher trans isomer content contributes to improved folding endurance.
Examples 9 and 10
[0146] Polyamic acids are prepared as in Example 1 except that a combination of BPDA and PMDA is used as an acid dianhydride. Polyimide films are then produced. Test results are shown in Table 3.
Examples 11 and 12
[0147] Polyamic acids are prepared as in Example 1 except that a combination of 14BAC (cis/trans ratio: 9/91) and NBDA is used as a diamine and that PMDA is used as an acid dianhydride. Polyimide films are then produced. Test results are shown in Table 3.
Example 13
[0148] A polyamic acid (polyamic acid of Synthesis 1) is prepared as in Example 1 except that norbornanediamine (NBDA) is used instead of 1,4-bis(aminomethyl)cyclohexane (14BAC). The resultant polyamic acid has an intrinsic logarithmic viscosity of 0.51 dL/g (35° C., 0.5 g/dl). The polyamic acid of Synthesis 1 and the polyamic acid of Example 1 are mixed in a molar ratio of 1:3. From the mixture varnish, a polyimide film is produced as in Example 1. Test results are shown in Table 4.
Example 14
[0149] A polyamic acid (polyamic acid of Synthetic 2) is prepared as in Example 1 except that pyromellitic dianhydride (PMDA) is used instead of 3,3′,4,4′-diphenyltetracarboxylic dianhydride (BPDA). The resultant polyamic acid has an intrinsic logarithmic viscosity of 0.69 dL/g (35° C., 0.5 g/dl). The polyamic acid of Synthesis 2 and the polyamic acid of Example 1 are mixed in a molar ratio of 1:1. From the mixture varnish, a polyimide film is produced as in Example 1. Test results are shown in Table 4.
Example 15
[0150] The polyamic acid of Synthesis 2 and the polyamic acid of Example 1 are mixed in a molar ratio of 1:3. From the mixture varnish, a polyimide film is produced as in Example 1. Test results are shown in Table 4.
Example 16
[0151] A polyamic acid is prepared as in Example 1 except that as a diamine compound norbornanediamine (NBDA) is used instead of 1,4-bis(aminomethyl)cyclohexane (14BAC) and that as a tetracarboxylic dianhydride pyromellitic dianhydride (PMDA) is used instead of 3,3′,4,4′-biphenyltetracarboxylic dianhydride (BPDA) (polyamic acid of Synthesis 3). The resultant polyamic acid has an intrinsic logarithmic viscosity of 0.58 dL/g (35° C., 0.5 g/dl). The polyamic acid of Synthesis 3 and the polyamic acid of Example 1 are mixed in a molar ratio of 1:1. From the mixture varnish, a polyimidc film is produced as in Example 1. Test results are shown in Table 4.
[0000]
TABLE 3
Total
Tensile
MIT folding
light
Modulus
endurance
transmit-
of
(Number of
Acid dianhydride
Diamine
η
T g
CTE
tance
Elasticity
double folds
BPDA
PMDA
14BAC
NBDA
(dL/g)
(° C.)
(ppm/K)
(%)
(GPa)
until failure)
Ex. 9
0.5
0.5
1
0
0.85
302
42
89
2.28
>100,000
@1.0 kg tension
Ex. 10
0.75
0.25
1
0
0.76
278
46
88
2.21
>100,000
@1.0 kg tension
Ex. 11
0
1
0.25
0.75
0.5
296
44
89
2.05
23,000
@0.5 kg tension
Ex. 12
0
4
0.5
0.5
0.68
365
44
90
1.95
36,000
@0.5 kg tension
Values in [Acid dianhydride] or [Diamine] represent the copolymerization ratio of the monomeric unit in polyamic acid.
[0000]
TABLE 4
Total
Tensile
MIT folding
light
Modulus
endurance
transmit-
of
(Number of
Acid dianhydride
Diamine
η
T g
CTE
tance
Elasticity
double folds
BPDA
PMDA
14BAC
NBDA
(dL/g)
(° C.)
(ppm/K)
(%)
(GPa)
until failure)
Ex. 13
1.00
0.00
0.75
0.25
0.72
252
48
88
2.82
>100,000
@1.0 kg tension
Ex. 14
0.50
0.50
1.00
0.00
0.87
289
45
89
2.22
>100,000
@1.0 kg tension
Ex. 15
0.75
0.25
1.00
0.00
0.85
264
47
88
2.46
>100,000
@1.0 kg tension
Ex, 16
0.50
0.50
0.50
0.50
0.69
275
49
88
2.30
22,000
@0.5 kg tension
Values in [Acid dianhydride] or [Diamine] represent the total content of the momoneric unit in mixture polyamic acid.
[0152] As seen from Table 3, even when a combination of 1,4-bis(aminomethyl)cyclohexane and other diamine is used as a diamine unit of polyimide, the use of 1,4-bis(aminomethyl)cyclohexane that is rich in trans isomer provides a polyimide film that offers high Tg as well as excellent folding endurance.
[0153] Moreover, as seen from Table 4, even when a mixture polyimide is used that consists of a polyimide having 1,4-bis(aminomethyl)cyclohexane as a diamine unit and a polyimide having other diamine as a diamine unit, the use of 1,4-bis(aminomethyl)cyclohexane that is rich in trans isomer provides a polyimide film that offers high Tg as well as excellent folding endurance.
Example 17
[0154] Acicular titanium oxide (FTL-300, Ishihara Sangyo Kaisha Ltd.; fiber length: 5.15 μm, fiber diameter: 0.27 μm) is added in the polyamic acid solution of Example 1 in N,N-dimethylacetamide in an amount of 55 parts by weight per 100 parts by weight of the polyamic acid of Example 1, to produce a white polyamic acid solution. The polyamic acid solution is applied over a glass substrate with a bar coater with a 0.6 mm gap, heated from room temperature to 250° C. over 2 hours in a nitrogen gas stream, and heated at 250° C. for a further 2 hours to complete imidization of the applied film. In this way a white polyimide film is produced.
Example 18
[0155] A white polyimide film is produced as in Example 17 except that acicular titanium oxide (FTL-300, Ishihara Sangyo Kaisha Ltd.) is added in an amount of 20 parts by weight per 100 parts of the polyamic acid.
Example 19
[0156] A white polyimide film is produced as in Example 17 except that the bar coater gap is set to 0.25 mm.
Example 20
[0157] A white polyimide film is produced as in Example 17 except that acicular titanium oxide (FTL-200, Ishihara Sangyo Kaisha Ltd.; fiber length: 2.86 μm, fiber diameter: 0.21 μm) is used instead of acicular titanium oxide (FTL-300, Ishihara Sangyo Kaisha Ltd.).
Examples 21 and 22
[0158] White polyimide films are produced as in Example 17 except that the added amount of acicular titanium oxide (FTL-200, Ishihara Sangyo Kaisha Ltd.) or the bar coater gap is changed in accordance with Table 5.
Example 23
[0159] A white polyimide film is produced as in Example 17 except that acicular titanium oxide (FTL-110, Ishihara Sangyo Kaisha Ltd.; fiber length: 1.68 μm, fiber diameter: 0.13 μm) is used instead of acicular titanium oxide (FTL-300, Ishihara Sangyo Kaisha Ltd.).
Examples 24 and 25
[0160] White polyimide films are produced as in Example 23 except that the added amount of acicular titanium oxide (FTL-110, Ishihara Sangyo Kaisha Ltd.) or the bar coater gap is changed in accordance with Table 5.
Example 26
[0161] A white polyimide film is produced as in Example 17 except that acicular titanium oxide (FTL-100, Ishihara Sangyo Kaisha Ltd.; fiber length: 1.68 μm, fiber diameter: 0.13 μm) is used instead of acicular titanium oxide (FTL-300, Ishihara Sangyo Kaisha Ltd.).
Examples 27 and 28
[0162] White polyimide films are produced as in Example 26 except that the added amount of acicular titanium oxide (FTL-100, Ishihara Sangyo Kaisha Ltd.) or the bar coater gap is changed in accordance with Table 5.
Example 29
[0163] A white polyimide film is produced as in Example 17 except that spherical titanium oxide (R-980, Ishihara Sangyo Kaisha Ltd.; average particle size: 0.24 μm) is used instead of acicular titanium oxide (FTL-300, Ishihara Sangyo Kaisha Ltd.).
Examples 30 and 31
[0164] White polyimide films are produced as in Example 29 except that the added amount of spherical titanium oxide (R-980, Ishihara Sangyo Kaisha Ltd.) or the bar coater gap is changed in accordance with Table 5.
Example 32
[0165] A white polyimide film is produced as in Example 17 except that zinc oxide (average particle size: 5 μm) is used instead of acicular titanium oxide (FTL-300, Ishihara Sangyo Kaisha Ltd.).
Examples 33 and 34
[0166] White polyimide films are produced as in Example 32 except that the added amount of zinc oxide or the bar coater gap is changed in accordance with Table 5.
[0167] The white polyimide films prepared in Examples 17 to 34 are measured for reflectivity for light at 550 nm wavelength in accordance with the procedure described below. Measurement results are shown in Table 5.
[0000]
TABLE 5
Added
amount
Bar coater
Film
Light
(parts by
gap
thickness
reflectivity
White inorganic filler
weight)
(mm)
(μm)
(%)
Ex. 17
Acicular titanium oxide: FTL-300
55
0.6
65
84
Ex. 18
Acicular titanium oxide: FTL-300
20
0.6
48
76
Ex. 19
Acicular titanium oxide: FTL-300
55
0.25
20
57
Ex. 20
Acicular titanium oxide: FTL-200
55
0.6
76
85
Ex. 21
Acicular titanium oxide: FTL-200
20
0.6
58
77
Ex. 22
Acicular titanium oxide: FTL-200
55
0.25
24
61
Ex. 23
Acicular titanium oxide: FTL-110
55
0.6
97
83
Ex. 24
Acicular titanium oxide: FTL-110
20
0.6
60
75
Ex. 25
Acicular titanium oxide: FTL-110
55
0.25
29
60
Ex. 26
Acicular titanium oxide: FTL-100
55
0.6
77
86
Ex. 27
Acicular titanium oxide: FTL-100
20
0.6
55
78
Ex. 28
Acicular titanium oxide: FTL-100
55
0.25
25
58
Ex. 29
Spherical titanium oxide: R-980
55
0.6
75
89
Ex. 30
Spherical titanium oxide: R-980
20
0.6
50
83
Ex. 31
Spherical titanium oxide: R-980
55
0.25
20
64
Ex. 32
Zinc oxide
55
0.6
64
67
Ex. 33
Zinc oxide
20
0.6
48
51
Ex. 34
Zinc oxide
55
0.25
23
50
[0168] Measurement of Light Reflectivity
[0169] With Hitachi U-3010 spectrophotometer (Hitachi High-Technologies Corporation), the light reflectivity of the polyimide film is measured over the range from 300 nm to 800 nm, and a value of light reflectivity measured at 550 nm is employed as light reflectivity.
[0170] All of the polyimide films prepared in Examples 17 to 34 are evenly colored in pure white. As seen from the results of Examples 17 to 34, white polyimide films containing zinc oxide or titanium oxide exhibit at least a certain level of light reflectivity. In particular, it can be seen that titanium oxide provides high light reflectivity compared to zinc oxide even when they are added in equal amounts. Moreover, it can be seen that spherical titanium oxide provides high light reflectivity compared to acicular titanium oxide.
[0171] This application is entitled and claims the priority of Japanese Patent Application No. 2009-51102 filed on Mar. 4, 2009, the disclosure of which including the specification, drawing and abstract is herein incorporated by reference in its entirety.
INDUSTRIAL APPLICABILITY
[0172] The present invention provides a polyimide resin with high heat resistance without impairing its inherent properties. The polyimide resin of the present invention is suitable for coating materials, display materials for displays, and circuit board materials. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to bubble ink jet printing systems and, more particularly, to an improved integrated circuit chip for use in a thermal ink jet printhead which contains active driver, logic and resistive heater elements and a method for making the chip.
2. Description of Related References
Drop-on-demand thermal ink jet printers are generally well known, and in such systems a thermal printhead comprises one or more ink filled channels communicating with a relatively small ink supply chamber and a linear array of orifices, generally referred to as nozzles. A plurality of thermal transducers, usually resistors, are located in the channels at a predetermined location relative to the nozzles. The resistors are individually addressed with a current pulse to momentarily vaporize the ink in contact therewith and form a bubble which expels an ink droplet. As the bubble grows, the ink bulges from the nozzle and is contained by the surface tension of the ink as a meniscus. As the bubble begins to collapse, the ink between the nozzle and bubble starts to move towards the collapsing bubble, causing a volumetric contraction of the ink at the nozzle and resulting in the separation of the bulging ink as a droplet. The acceleration of the ink out of the nozzle while the bubble is growing provides the momentum and velocity required for the droplet to proceed in a substantially straight line direction towards a recording medium, such as paper.
In order to generate the resistor current pulses, some type of active driver device must be employed. Preferably, the driver circuitry should be formed on the same chip as the resistive elements. It is generally known to utilize bipolar or less expensive MOS type circuitry as the active driver devices. A typical device which utilizes bipolar type circuitry is disclosed in U.S. Pat. No. 4,429,321 to Matsumoto. In the Matsumoto patent, a liquid jet recording device is disclosed, wherein a method of fabricating the device is shown which incorporates a control unit and a transducer on a single substrate. The control unit in this recorder is a bipolar type of transistor. A method of doping using various implants to create a resistor is shown (see Table 1). A base region of the bipolar transistor is fabricated using boron doping. Unfortunately, bipolar transistors exhibit destructive thermal run away when switching high currents. Therefore, it is desirable and generally more cost effective to have a resistor structure which is immediately and simply integrated on the same wafer with an accompanying MOS driver.
For example, U.S. Pat. No. 4,947,192 to Hawkins et al. discloses a monolithic silicon integrated circuit chip for a thermal ink jet printer wherein a MOS transistor and a resistor are formed on the same substrate. A lightly doped source and drain layer is shown. The relevant portions of the disclosure of U.S. Pat. No. 4,947,192 issued to Hawkins et al., are hereby incorporated by reference into this specification.
The Hawkins et al. reference describes the importance of combining driver and transducer elements on a single chip. Moreover, the reference indicates the potential for adding logic circuitry capable of addressing an arbitrarily large number of ink jets with minimal electrical connections. Such a monolithic device, having logic elements, drivers, and transducers incorporated therein, would generally require added photoresist masking and implant steps to produce enhancement and depletion mode logic devices. While such a structure is desirable, the added processing steps result in potentially higher yield losses and manufacturing costs. A device of this type may be achieved using a single polysilicon layer, as indicated by Hawkins et al. Specifically, The source-drain n+ contacts are doped with arsenic, while polysilicon is doped with phosphorous to create low resistivity (25 Ω/□) material at the ends of the transducers. Unfortunately, such a structure would require at least two additional processing steps to implant the arsenic and phosphorous in their respective locations. This would result in an eleven mask step process to create the structure previously disclosed in the Hawkins et al. reference.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention, to provide a more reliable monolithic silicon semiconductor integrated chip incorporating MOS transistor control logic, drivers, and resistive heater elements.
It is another object of the present invention to provide an improved NMOS fabrication technique so as to provide an ink jet printing head that requires less processing steps in its manufacture, and is, therefore, more cost effective to manufacture than prior art devices.
It is yet another object of the present invention to produce, using a self aligned p+ implant, a thermal ink jet printhead having a suppressed power MOS driver parasitic bipolar effect.
It is an additional object of the present invention to provide a monolithic thermal ink jet printhead having phosphorous doped sourcedrain regions and resistor ends to achieve lightly doped drain structures in the logic and driver sections, while simultaneously reducing the resistance of the resistor ends, thereby reducing the parasitic resistance of the resistors.
It is still another object of the present invention to produce, by utilizing a borophosphosilicate reflow glass, a monolithic thermal ink jet circuit chip having phosphorous doped source-drain regions and resistor ends, thereby reducing the parasitic resistance of the resistors.
The present invention is therefore directed to an improved monolithic silicon integrated circuit chip, and process for producing the aforementioned monolithic device, for use in an ink jet printing system. More particularly, the invention relates to methods by which mask and implant steps can be combined to reduce the number of critical processing steps, thereby reducing the overall cost of such a device. Specifically, the present invention is directed at replacing the separate arsenic (As) source-drain and phosphorous polysilicon masking and implant steps with a single phosphorous masked implant step. Previously, such a combination was undesirable, as the phosphorous doping of the source-drain contacts caused lateral diffusion under the 5 micron (μm) gates during glass reflow. The lateral diffusion of the phosphorous was sufficient to cause serious degradation, or even shorting, of the logic devices. However, this invention includes techniques for reducing the lateral diffusion problems.
The present invention utilizes methods of achieving a single phosphorous masked implant, which are directed towards reducing the lateral encroachment of the phosphorous doped source-drain contact regions. In one method, a n-drift layer implant is employed to compensate for the lateral diffusion of the phosphorous. A second method utilizes a borophosphosilicate glass as the reflow glass to reduce the amount of lateral diffusion of the phosphorous during the reflow cycle. Moreover, the combination of the two slightly different methods produces no deleterious effects in the resulting monolithic device.
The present invention further eliminates a second mask level by self-aligning the boron substrate contact to the etched vias in the reflow glass layer. The self-aligned boron substrate contact makes use of boron diffusivity suppression in n+ silicon. Areas which are desired for substrate contact are shielded from the phosphorous n+ implant, leaving the substrate doped with the n- drift region. Upon etching vias through the reflow glass and oxide layers, vias to be made into substrate contacts have n- drift regions, and sources, drains, and gates are n+ doped. Subsequently, the selfaligned boron implant is introduced through the vias, where the high diffusivity of boron in n- regions causes compensation and conversion to p+ regions, as well as, penetration of the n- layer. In the n+ regions, boron is totally contained within the region due to suppression of its diffusivity within the region.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the invention, detailed example embodiments thereof will now be described with reference to the accompanying drawings, in which:
FIG. 1 is a schematic perspective view of a carriage type bubble jet ink printing system having a printhead which incorporates the present invention.
FIG. 2 is an enlarged schematic perspective view of the bubble jet ink printing head of FIG. 1.
FIG. 3 is an enlarged, cross-sectional view of a prior art silicon logic integrated circuit, as disclosed by Hawkins et al. in U.S. Pat. No. 4,947,192.
FIG. 4 is an enlarged, cross-sectional view of an embodiment of the integrated circuit chip of the present invention.
FIGS. 5a-5e are enlarged, cross-sectional views of the process steps for fabricating the integrated circuit chip of the present invention.
FIGS. 6a-6c are enlarged, cross-sectional views of alternate process steps for fabricating the integrated circuit chip of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The printers which make use of thermal ink jet transducers can contain either stationary paper and a moving print head or a stationary pagewidth printhead with moving paper. A carriage type bubble jet ink printing device 10 is shown in FIG. 1. A linear array of droplet producing ink jet channels is housed in the printing head 11 of reciprocating carriage assembly 29. Droplets 12 are propelled to the recording medium 13 which is stepped by stepper motor 16 a preselected distance in the direction of arrow 14 each time the printing head traverses in one direction across the recording medium in the direction of arrow 15. The recording medium, such as paper, is stored on supply roll 17 and stepped onto roll 18 by stepper motor 16 by means well known in the art.
The printing head 11 is fixedly mounted on support base 19 which is adapted for reciprocal movement by any well known means such as by two parallel guide rails 20. The printing head base comprise the reciprocating carriage assembly 29 which is moved back and forth across the recording medium in a direction parallel thereto and perpendicular to the direction in which the recording medium is stepped. The reciprocal movement of the head is achieved by a cable 21 and a pair of rotatable pulleys 22, one of which is powered by a reversible motor 23.
The current pulses are applied to the individual bubble generating resistors in each ink channel forming the array housed in the printing head 11 by connections 24 from a controller 25. The current pulses which produce the ink droplets are generated in response to digital data signals received by the controller through electrode 26. The ink channels are maintained full during operation via hose 27 from ink supply 28.
FIG. 2 is an enlarged, partially sectioned, perspective schematic of the carriage assembly 29 shown in FIG. 1. The printing head 11 is shown in three parts. One part is the substrate 41 containing the electrical leads and monolithic silicon semi-conductor integrated circuit chip 110 therein in the region 110A shown in dashed line. The next two parts comprise the channel plate 49 having ink channels 49a and manifold 49b. Although the channel plate 49 is shown in two separate pieces 31 and 32, the channel plate could be an integral structure. The ink channels 49a and ink manifold 49b are formed in the channel plate piece 31 having nozzles 33 at the end of each ink channel opposite the end connecting the manifold 49b. The ink supply hose 27 is connected to the manifold 49b via a passageway 34 in channel plate piece 31 shown in dashed line. Channel plate piece 32 is a flat member to cover channel 49a and ink manifold 49b as they are appropriately aligned and fixedly mounted on the silicon substrate. In an alternate printhead configuration (not shown), the nozzles are located from channel plate piece 31 to the flat channel plate piece 32 and at a position directly over the thermal transducer or resistors to form a printhead which ejects droplets in a direction normal to the resistors.
The prior art integrated circuit chip 48, shown in FIG. 3, is formed, to some extent, according to standard NMOS process steps but modified in certain respects, as described in full detail in U.S. Pat. No. 4,947,192 to Hawkins et al. In order to appreciate the process steps required to produce the prior art chip of FIG. 3, one is referred to this Hawkins et al. patent which has been incorporated by reference. FIG. 3 shows an active address chip 48 having an MOS transistor switch monolithically integrated on the same substrate with the resistor by a fabrication process requiring eleven masks. The chip is constructed by techniques disclosed by Hawkins et al. in U.S. Pat. No. 4,947,192, the techniques resulting in improved performance as described therein.
With respect to the present invention, integrated circuit chip 110, illustrated in FIG. 4, is formed using a modified NMOS process. The modifications, discussed in detail below, yield a less complex masking process, thereby resulting in a lower cost monolithic integrated circuit chip having control logic, drivers, and transducers integrated thereon. The chip also has higher breakdown voltages for the logic devices than other prior art devices. Referring now to FIG. 4, integrated circuit chip 110 is divided into 4 types of electrical elements; viz., logic enhancement element 112, logic depletion element 114, driver 116 and thermal transducer 118. The chip is constructed by modifying the techniques used to make the structure of FIG. 3, thereby resulting in a lower cost, higher yield process for producing chips with improved performance.
As disclosed in U.S. Pat. No. 4,947,192 but not shown in the accompanying drawings, a P type silicon wafer 146, having front and back surfaces, is processed to form a thin SiO 2 layer on both surfaces, followed by deposition of a silicon nitride masking layer over the SiO 2 layers. A first photoresist mask (not shown) is applied and patterned over the areas which will form the active enhancement and depletion mode device areas 112, 114, and 116. The first photoresist layer is used to pattern the silicon nitride layer (not shown) and then to block channel stop boron implant regions 124 from the active device areas. The patterned first photoresist layer is stripped and the SiO 2 layer is etched off using the patterned silicon nitride layer as a mask.
Referring now to FIGS. 5a-5e in conjunction with FIG. 4, a field oxide layer 125 is grown at high temperature after the boron channel stop implant 124 is set and the SiO 2 layer thereover is removed. According to a first aspect of the invention, the field oxide layer is at least 1 micron (μm) thick and preferably 1.5 μm thick. The patterned silicon nitride layer and underlying SiO 2 layer are stripped. Subsequently, a 1000 Å sacrificial oxide layer (not shown) is grown and a second photoresist depletion mask (not shown) is patterned on the surface of the wafer. The sacrificial oxide layer in depletion area 114 is etched off. The depletion mask enables the exposure of only the logic depletion gate areas in the depletion areas 114 to the As+ ions for the depletion implant 226. Next, the depletion mask is stripped, the remaining sacrificial oxide layer is etched off and gate oxide layer 126 is grown over the channel areas. Gate oxide layer 126 is preferably about 900 Å in thickness. A boron implant is conducted through the gate oxide layer and is blocked by the field oxide layer 125. The wafer 146 is presently in the condition illustrated by FIG. 5a, having depletion implant 226 in depletion area 114, and enhancement boron implants 230 in enhancement and driver areas 112 and 116, respectively. Subsequently, a single polysilicon layer 228 of greater than 4000 Å, preferably about 4500 Å, in thickness is deposited and then implanted with n-type ions, preferably phosphorous (P+) ions, to produce n+ polysilicon with a sheet resistance between 5 Ω/□ and 5 kΩ/□, preferably about 47 Ω/□, as shown in FIG. 5a.
The next step in the process is illustrated in FIG. 5b, and involves the patterning and etching of the polysilicon layer 228 shown in FIG. 5a to form the transistor gates 128 and resistor 129 by the deposition and patterning of a third photoresist layer (not shown). Subsequently, the photoresist layer is stripped and n- drift layers 229 are produced by a light, self-aligned P+ drift implant (2×10 16 /cm 3 ) to produce a layer having a sheet resistance between 500 Ω/□ and 20 kΩ/□ but, preferably, about 5 kΩ/□. When subjected to the drift implant, the polysilicon remains as n+ polysilicon suitable for the gate and resistor regions, indicated by reference numerals 128 and 129, respectively. By self-aligning the n- drift layer 229 to the polysilicon gate 128, breakdown voltage can be extended to values in the range of 80-90 volts. After the drift implant, a masked phosphorous (P+) implant is completed as illustrated in FIG. 5c. Specifically, the wafer is patterned with a fourth photoresist layer 232 to shield not only portions of the gate and resistor polysilicon, but also portions of the underlying source and drain contact regions 229. In addition, some of the driver source contacts, preferably one in every six, are masked to shield them from the phosphorous implant. These contacts are dispersed about the wafer surface to enable p+ substrate contacts for grounding through the top surface of the wafer, thereby eliminating the parasitic bipolar effect generally associated with grounding through the bottom surface of the wafer. Having photoresist layer 232 applied, the wafer is again exposed to a phosphorous implant, this one for the source-drain contacts. The unmasked regions of polysilicon thereby becoming more highly doped with phosphorous ions. Referring to FIG. 5d, the unmasked regions of the underlying wafer forming highly doped source-drain regions 130, having a sheet resistance of between 15 Ω/□ and 30 Ω/□, while those regions of the wafer covered by the fourth masking layer 232 remain as lightly doped source-drain regions, 132. In addition, the unmasked portions of the transducer element polysilicon region also become more highly doped with P+ ions, thereby making the ends, 234 and 236, of the resistor polysilicon layer 129 more conductive than the inner portion of the layer 238. This eventually results in a more efficient resistor configuration as the "hot" portion of the resistor, area 238, is concentrated where the heat will be most efficiently dissipated to the ink. Moreover, the contact regions 234 and 236 on the end of the resistor will remain cooler, thereby prolonging the life of the contacts.
After the phosphorous source-drain implant, shown in FIG. 5c, the fourth photoresist layer 232 is stripped and the wafer is cleaned. Following the growth of a protective oxide layer (not shown) over the polysilicon and source-drain regions, a glass layer 244 is deposited and reflowed across the entire surface of the wafer. The glass is preferably a 7.5% phosphosilicate glass (PSG) that is deposited in a 90 minute reflow cycle at a temperature of about 1000° C.
Alternatively, the glass may be a borophosphosilicate glass (BPSG), because it can be reflowed at a lower temperature and shorter time, thereby eliminating the problem of lateral diffusion of the phosphorous in contacts 130 into the channel regions beneath the gates. Moreover, PSG tends to loose phosphorous by evaporation during reflow, resulting in a lower phosphorous content along the upper surface of the reflow layer 244. During etching, the lower phosphorous content areas etch much more slowly, causing etched vias 242 to have sharp corners. BPSG however, does not suffer from this phosphorous loss problem and, therefore, produces smoother more gradually sloped vias which are more desirable.
Subsequent to the glass reflow cycle, the wafer is again patterned with a fifth photoresist layer (not shown) to enable wet etching of the contact vias 242. Wet etching is used to reduce deleterious effects to polysilicon layer 129, in transducer region 118, which is also re-exposed by the etch process. After wet etching the glass and source-drain oxide layers, the fifth photoresist layer is stripped, resulting in the structure illustrated in FIG. 5d, having vias 242 present in glass layer 244, to provide access to the source-drain contacts and/or polysilicon regions.
Once vias 242 are etched through glass 244 and the oxide layers exposing wafer 146, they form the patterning mechanism for the subsequent self-aligned boron implant as illustrated in step 5e. After the boron (B+) implant, the wafer is cleaned and the implant is activated by heating the wafer to about 1000° C. for a 30 minute period, during which some reflow of the glass within the vias will occur. The following processing steps directed towards completion of the transducer structure, contact circuitry, and protection layers are shown in FIG. 4, where a Si 3 N 4 layer 138 is deposited over the wafer surface, followed by a Ta layer 136. The Tantalum layer is then patterned using a sixth photoresist layer (not shown) and etch procedure, leaving the tantalum layer 136 only over the operative resistor region of transducer 118. Subsequently, the sixth photoresist layer is stripped and the Si 3 N 4 layer is etched, using the Tantalum layer as a mask for the underlying Si 3 N 4 layer 138. Following a cleaning operation, aluminum metallization is applied and patterned with a seventh photoresist layer (not shown) to form interconnections 140, 142, and 144 to the logic, driver and transducer elements on the wafer, respectively. The wafer is then cleaned and protective layers of SiO 2 , and optionally Si 3 N 4 , are deposited and subsequently patterned with an eighth photoresist layer prior to etching to expose the thermal transducer 118 and integrated circuit contact pads (not shown). Subsequently, a thick film polyimide layer (not shown) is deposited over all regions of the wafer and patterned with a ninth photoresist layer, and subsequent etch, to delineate the central portions of the Ta layer 136 over the transducer, thus placing them in pits (not shown), and integrated circuit contact pads.
The use of a set-back source-drain photoresist pattern 232 enables the elimination of one photoresist patterning and etch process, by eliminating the need for an additional arsenic implant. Furthermore, the use of the self aligned boron implant, illustrated in FIG. 5e, eliminates the need for a boron implant patterning operation. The above process eliminates two patterning operations from the previously required eleven mask process disclosed in U.S. Pat. No. 4,947,192. These patterning operations are extremely cost intensive and the elimination of two mask levels results in cost savings of approximately twenty percent over the process previously used for thermal ink jet printhead chips.
In an alternate embodiment, the aforedescribed arsenic and phosphorous masking and implant steps which were combined into a single phosphorous masked implant step utilizes the lower temperature processing enabled by the borophosphosilicate glass (BPSG), thereby allowing the use of self-aligned phosphorous contacts in the logic sections of the chip.
FIGS. 6a-6c illustrate the process modifications to the process steps delineated in FIGS. 5a-5e which are enabled by use of the BPSG reflow in place of the PSG reflow illustrated in FIG. 5d. This alternate fabrication process is identical with the above described invention through the process step of FIG. 5b. Referring now to FIG. 6a, the photoresist mask 332 has been modified from mask 232 in FIG. 5c to expose the lightly doped source-drain regions 132 of FIG. 5D to the phosphorous source-drain implant. Subsequent to the phosphorous implant, the borophosphosilicate glass 344 is reflowed over the surface of the wafer for a period of about 30 minutes, and at a temperature of about 950° C. The lower temperature and shorter time period substantially limits the lateral diffusion of the phosphorous in the channel regions 226 and 230. Next, patterning and etch procedures are applied to BPSG layer 344 to produce vias 342 therein, exposing the wafer surface through thermal oxide layer 340 as illustrated in FIG. 6b. The resulting vias 342 provide access to the source-drain contact regions 130. More importantly, use of BPSG, and the reduced time of the reflow cycle further reduces or eliminates the requirement for the set-back of the source-drain contacts 130, and n- drift layer 132, as illustrated in FIG. 5c-5e. Accordingly, use of BPSG alone enables the production of electrical contacts having junction depths comparable to those achieved with the prior art.
As in the previously discussed process in FIGS. 5a to 5e, some of the driver source contacts, preferably one in every six, are masked to shield them from the phosphorous implant. These contacts are dispersed about the wafer surface to enable p+ substrate contacts for grounding through the top surface of the wafer, thereby eliminating the parasitic bipolar effect generally associated with grounding through the bottom surface of the wafer. The ground contacts, including every sixth source contact in the driver section, are completed by doping contacts with a self-aligned boron implant as shown in FIG. 6c using the patterned BPSG as a mask. In this step, the BPSG acts as the patterning mechanism for the boron substrate contact implant. Subsequently, the wafer is cleaned and the implants are activated by an additional heating cycle of approximately 30 minutes at about 900° C. Following the implant activation step, the wafer would be completed as previously described in FIG. 4, by producing the silicon nitride transducer insulator and tantalum surface layers, depositing and patterning the aluminum contact layer, and subsequently coating the remainder of the wafer with patterned layers of SiO 2 , Si 3 N 4 , and polyimide. The use of BPSG as the reflow glass also enables the elimination of one photoresist patterning and etch process, by eliminating the need for the separate arsenic implant. Furthermore, the use of the self aligned boron implant, illustrated in FIG. 6c, eliminates the need for a boron implant patterning operation. Ultimately, modification of the process in the manner described will also eliminate 2 patterning operation from the prior art eleven mask process.
In addition, the use of phosphorous, well know for its ability to suppress aluminum-silicon reactions at contacts, would result in a significant reduction in junction spiking in the contact regions.
The two methods which have just been discussed demonstrate that logic and driver elements can be simultaneously fabricated with the resistive transducer elements using a reduced mask/implant step process. Addition of the logic circuitry enables the further reduction in interconnections which becomes important for interfacing to large arrays. The NMOS logic circuits are added by including depletion mode photoresist masking and implant process steps in the fabrication sequence so that normally on and normally off devices are available to form logic gates. The polysilicon which is used to form the resistor elements and gates of drivers is simultaneously used to form the gates of the logic circuit elements.
Generally, reduction in the mask steps required to produce the monolithic integrated circuit for the thermal ink jet printing module would serve to reduce the cost of the module. More specifically, by eliminating two of the eleven mask steps, cost savings in the range of twenty percent can be achieved in the integrated circuit. Therefore, the present invention replaces the separate arsenic (As) source-drain and phosphorous polysilicon masking and implant steps with a single phosphorous masked implant step. In addition, by using a self-aligned boron source-drain implant, an additional mask step is eliminated, resulting in a more efficient nine mask step process.
Many modifications and variations are apparent from the foregoing description of the invention and all such modifications and variations are intended to be within the scope of the present invention. | 4y
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This is a division of 508,370, filed Apr. 11, 1990, now U.S. Pat. No. 5,034,526 which is a continuation-in-part of U.S. Ser. No. 07/241,319, filed Sep. 7, 1988, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of Invention
The present invention relates to photosensitive compounds that generate free radicals upon exposure to light. More particularly, it relates to derivatives of halomethyl-1,3,5-triazines.
2. Discussion of the Prior Art
Compounds that decompose to generate free radicals (free radical generating agents) upon exposure to light are well known in the graphic arts. Organic halogen compounds, which are capable of generating free radicals such as a chlorine free radical or a bromine free radical upon exposure to light, have been widely used as photoinitiators in photopolymerizable compositions, as photoactivators in free radical photographic compositions, and as photoinitiators for reactions catalyzed by acids formed by light. The spectral sensitivity of these compositions may be broadened by the addition of sensitizers which, in essence, transfer their absorbed energy to the organic halogen compound. The use of such halogen compounds in photopolymerization processes and free radical photographic processes have been described in Kosar, Light-Sensitive Systems, J. Wiley & Sons (New York, 1965) pp. 180-181, 361-370.
Halomethyl-1,3,5-triazines are known to be initiators for a number of photochemical reactions. They are employed to produce free radicals for initiating polymerization or color changes and for initiating secondary reactions upon liberation of acid by the interaction of the free-radicals when hydrogen donors are present.
Examples of the use of halomethyl-1,3,5-triazines in the free radical polymerization of acrylate monomers are described in U S. Pat. No. 3,905,815; U.S. Pat. No. 3,617,288; U.S. Pat. No. 4,181,752; U.S. Pat. No. 4,391,687; U.S. Pat. No. 4,476,215; and DE 3,517,440. U.S. Pat. No. 3,779,778 discloses the photoinitiated acid catalyzed decomposition of pyranyl ether derivatives to produce photosolubilizable compositions useful as positive printing plates. Chromophore substituted styryl-1,3,5-triazines and their uses are disclosed in U.S. Pat. No. 3,987,037 and U.S. Pat. No. 3,954,475. Radiation sensitive compositions containing bi- and polyaromatic substituted triazines are disclosed in U.S. Pat. No. 4,189,323.
In compositions, the sensitivity of halomethyl-1,3,5-triazines to actinic radiation of a particular range of wavelengths can be increased by the incorporation of known ultraviolet and visible light sensitizers including cyanine, carbocyanine, merocyanine, styryl, acridine, polycyclic aromatic hydrocarbons, polyarylamines and amino-substituted chalcones. Cyanine dyes are described in U.S. Pat. No. 3,495,987. Styryl dyes and polyarylamines are described in Kosar, Light Sensitive Systems, J. Wiley and Sons (New York, 1965), pages 361-369. Polycyclic aromatic hydrocarbons useful as sensitizers, an example of which is 2-ethyl-9,10-dimethoxyanthracene, are described in U.S. Pat. No. 3,640,718. Amino substituted chalcones useful as sensitizers are described in U.S. Pat. No. 3,617,288. Halomethyl-1,3,5-triazines are used in conjunction with dialkylamino aromatic carbonyl compounds disclosed in U.S. Pat. No. 4,259,432; 2-(benzoylmethylene)-5-benzothiazolidene thiazole -4-1 compounds disclosed in E application 0109291, May 23, 1984; 3-keto-substituted coumarin compounds disclosed in U.S. Pat. No. 4,505,793; U.S. Pat. No. 4,239,850; Jpn. Kokai Tokkyo Koho JP 60 60,104 (85 60104); an Ger/ Offen 2,851,641.
SUMMARY OF THE INVENTION
This invention provides radiation-sensitive organo-halogen compounds that have good sensitivity in the ultraviolet and visible range of the spectrum, and are thus suitable for use in radiation-sensitive compositions. These compounds have a photo-labile halomethyl-1,3,5-triazine moiety and a sensitizer moiety within one molecule, thereby eliminating the need for a combination of compounds. In this fashion, the efficiency of transfer of energy between the sensitizer moiety and the triazine moiety is increased on account of the decreased physical distance between the two moieties. The compounds of this invention are good photoinitiators. Photopolymerizable and photocrosslinkable compositions containing them can be used in printing, duplicating, copying, and other imaging systems.
This invention provides compounds having a 1,3,5-triazine moiety having at least one halomethyl substituent on one carbon atom of the triazine nucleus, preferably a trihalomethyl group, and at least one sensitizer moiety on another carbon atom of the triazine nucleus, said sensitizer moiety not being part of the triazine chromophore, said sensitizer moiety being capable of absorbing actinic radiation, said sensitizer moiety having a λmax (i.e., absorption maximum) of at least 330 nm, preferably 350 nm up to 900 nm. The presence of the sensitizer moiety gives the compounds of this invention greater spectral sensitivity than halomethyl-1,3,5-triazine compounds not having such a sensitizer moiety. Representative examples of sensitizer groups include cyanine group, carbocyanine group, merocyanine group, aromatic carbonyl group, styryl group, acridine group, polycyclic aromatic hydrocarbyl group, polyarylamine group, amino-substituted chalcone group, etc.
The compound is capable of stimulation by actinic radiation at a wavelength of about 250 to 900 nanometers to generate free radicals or acids or both. These compounds are useful as photoreaction initiators for photosensitive compositions. They can be incorporated in photopolymerizable compositions and printing compositions useful for producing printing plates, such as lithographic plates, relief plates, or gravure plates, photoresists and photographic elements, and photosensitive resist forming compositions with which visible images are obtained upon exposure to light.
DETAILED DESCRIPTION OF THE INVENTION
As used herein, the term "sensitizer moiety" means a moiety containing at least one group that is not a part of the triazine chromophore and is capable of absorbing actinic radiation and enhancing spectral sensitivity.
Halomethyl substituted, 1,3,5-triazine compounds of this invention can be represented by the general formula I: ##STR1## wherein
A represent a member selected from the group consisting of mono-, di- and trihalo methyl groups,
Y represent a member selected from the group consisting of A, L-S, NH 2 , NHR, NR 2 , OR, and R', where R independently represents a substituted or unsubstituted alkyl group, preferably having 1 to 6 carbon atoms, or a substituted or unsubstituted aryl group, and R' represents a substituted or unsubstituted alkyl group, preferably having 1 to 6 carbon atoms, a substituted or unsubstituted aryl group, a substituted or unsubstituted alkenyl group, preferably having 2 to 6 carbon atoms, or a substituted or unsubstituted heterocyclic aromatic group,
S represents a sensitizer moiety that is not part of the triazine chromophore and is capable of absorbing actinic radiation, S having a λmax of at least 330 nm, and
L represents a group linking the sensitizer moiety to the triazine nucleus.
Halomethyl groups that are suitable for the present invention include chloro-, bromo-, and iodomethyl groups, with chloro- and bromomethyl groups being preferred. Trihalomethyl groups are preferred; most preferred are trichloromethyl and tribromomethyl groups.
Y represents any of a variety of substituents that are useful in modifying the physical, e.g., solubility, or chemical properties of the molecule, and preferably represents A, L-S, or R'. When Y represents A, the maximum number of halomethyl groups per triazine nucleus can be made available for radical generation. When Y represents L-S, the chemical composition for both L-S groups can be the same, or it can be different, depending on the composition of linking group L, sensitizer group S, or both. When Y represents R', and in particular when R' represents an aryl, aralkenyl, or heteroaromatic group, the spectral sensitivity of the triazine chromophore portion of the molecule can be varied, based on the photochemical response of R, to actinic radiation.
When R or R' represents an aryl group it is preferred that the group have a maximum of five rings, more preferably three rings, and most preferably one ring.
When R or R' represents a substituted group, the particular identity of the substituent is not critical. However, the substituents should not adversely affect the photoinitiation characteristics of the compounds of this invention.
S represents a sensitizer-containing group which, by itself, would not initiate photopolymerization upon exposure to actinic energy, but is nevertheless capable of absorbing actinic radiation, and transferring energy to the halomethyl-1,3,5-triazine moiety, thereby effectively increasing the spectral sensitivity of the halomethyl-1,3,5-triazine moiety. The sensitizer moiety has a λmax (i.e., absorption maximum) of at least 330 nm, preferably 350 nm up to 900 nm. S preferably comprises at least one member selected from the group consisting of cyanine group, carbocyanine group, merocyanine group, aromatic hydrocarbon group, polyarylamine group, and amino-substituted chalcone group. There is no upper limit on the number of sensitizer moieties per triazine nucleus; there is no upper limit on the number of triazine nuclei per sensitizer moiety; however, there must be at least one sensitizer moiety and at least one triazine nucleus. Preferably, the number of sensitizer moieties per triazine nucleus ranges from one to two or two to one; more preferably, there is one sensitizer moiety per triazine nucleus. If more than one sensitizer moiety is present per triazine nucleus, they can be from different generic classes or can be different species from the same generic class. If there is more than one triazine nucleus per sensitizer moiety, they can be of the same or of different species.
L represents a group that links the sensitizer moiety or moieties to the triazine nucleus. The precise identity of L is not critical, but it should be selected so that it does not interfere with or adversely affect the light sensitivity of the compound. Furthermore, L should be chosen so that it does not connect the chromophore of the halomethyl-1,3,5-triazine nucleus and the chromophore of the sensitizer moiety either directly by a covalent bond or by a conjugated linkage. However, any through space intramolecular complexation between the chromophores is not precluded. L can be a single group or can be formed from a combination of groups. Groups that are suitable for linking groups include carbamator (--NHCO 2 --), urea (--NHCONH--), amino (--NH--), amido (--CONH 2 --), aliphatic e.g., having up to 10 carbon atoms, alkyl, e.g., having up to 10 carbon atoms, alkenyl, e.g., having up to 10 carbon atoms, aryl, e.g., having one ring, styryl, ester (--CO 2 --), ether (--O--), and combinations thereof. Based on ease of synthesis, the most preferred groups for attachment directly to the triazine nucleus are carbamato, urea, amino, alkenyl, aryl, and ether. Whenever the group directly attached to the triazine nucleus is either alkenyl group or aryl group, another group must be interposed between the alkenyl group or aryl group and the sensitizer moiety to prevent the sensitizer moiety from forming a conjugate bond with the triazine nucleus.
The following structures exemplify typical --L--S combinations: ##STR2##
One method of preparing the compounds of this invention is by the addition reaction of isocyanato-substituted halomethyl-1,3,5-triazines with sensitizers having groups reactive with the isocyanate group. The isocyanato substituted triazines may be prepared from the corresponding amino derivative according to the procedure of U. Von Gizycki, Angew, Chem. Int. Ed. Eng., 1971, 10, 403. Isocyanato-1,3,5-triazines suitable for this reaction include:
2,4-bis(trichloromethyl)-6-isocyanato-1,3,5-triazine
2-isocyanato-4-methyl-6-trichloromethyl-1,3,5-triazine
2-isocyanato-4-phenyl-6-trichloromethyl-1-3,5-triazine
2-isocyanato-4-methoxy-6-trichloromethyl-1,3,5-triazine
2-isocyanato-4-(p-methoxyphenyl)-6-trichloromethyl-1,3,5-triazine
2-isocyanato-4-(p-methoxystyryl)-6-trichloromethyl-1,3,5-triazine
2-isocyanato-4-(m,p,-dimethoxyphenyl)-6-trichloromethyl-1,3,5-triazine
2,4,6-tris(isocyanato)-1-3,5-triazine
Examples of sensitizers that will combine with the isocyanto group include 4-(2'-hydroxyethyl)amino-N-2"-hydroxyethyl)-1,8-naphthalimide, 3,5-bis(dimethylaminobenzal)-4-piperidone, hydroxyethylrhodanine-N"-methylbenzothiazole, 1-aminopyrene, and 6-aminochrysene.
The isocyanate addition reaction can be carried out in the presence of solvents, such as, for example, toluene, pyridine, benzene, xylene, dioxane, tetrahydrofuran, etc., and mixtures of solvents. The duration and temperature of the reaction is dependent on the particular compounds and the catalyst employed. Generally, temperatures of about 25° to 150° for from one to seventy-two hours are sufficient to provide for the reaction. Preferably, the reaction is carried out at room temperature from three to seventy-two hours. The preferred catalyst is di-n-butyltin dilaurate.
Another method of preparing the compounds of this invention is the cotrimerization of organic nitriles having a sensitizer substituent with haloacetonitriles in accordance with the teachings of Wakabayashi et al, Bulletin of the Chemical Society of Japan, 1969, 42, 2924-30; still another method of preparing the compounds of this invention is the condensation reaction of an aldehyde compound having a photoinitiator functionality in accordance with the teachings of U.S Pat. No. 3,987,037; still another method of preparing the compound of this invention is the nucleophilic displacement reactions on halomethyl-1,3,5-triazines using sensitizers having free hydroxy or amino groups.
The natural sensitivity of halomethyl-1,3,5-triazines to actinic radiation is well known. Simple derivatives, such as 2-methyl-4,6-bistrichloromethyl-1,3,5-triazine, absorb actinic radiation in the lower ultraviolet region, e.g. below 300 nm.
Photosensitizers have been added to compositions containing halomethyl-1,3,5-triazines as separate materials to, in effect, broaden their natural range of sensitivity. This phenomenon is complex, and is believed to involve various types of energy transfer mechanisms from the excited states of the sensitizer. Moreover, the efficiency of physical combinations of sensitizing dye and photoinitiator is limited due to concentration, solubility, and light filtration factors. The compounds of this invention in which the sensitizer moiety and the halomethyl-1,3,5-triazine moiety are in the same molecule are more efficient for several reasons. They eliminate the need to add each material separately. They assure that the sensitizer moiety is very close to the triazine nucleus, thereby allowing lower concentrations and increased energy transfer efficiency.
A halomethyl-1,3,5-triazine compound having a chromophore substituted directly to the triazine nucleus has a broader sensitivity range than the unsubstituted halomethyl-1,3,5-triazine compound. See, for example, U.S. Pat. No. 3,954,475, U.S. Pat. No. 4,189,323, U.S. Pat. No. 4,391,687, and DE 3517440. However, the nature of the compounds in these patents is limited in that preparation thereof requires formation of a covalent bond or a conjugated linkage between the triazine nucleus and the chromophore substituent, typically by either an aryl group or a vinyl group. Because the triazine nucleus is not insulated from the chromophore substituent, it is difficult to predict, a priori, the absorption characteristics, i.e., absorption maxima, of the resulting chromophore-triazine combination because they will differ from those of both the chromophore and the triazine.
The compounds of this invention provide a wide variety of structures in that dye and triazine precursors can be prepared independently and then synthetically combined by simple reactions and without having to form a conjugated linkage. Also, the spectral sensitivity can be predicted, a priori, to correspond to the spectral sensitivity of the sensitizer moiety. By utilizing a sensitizer moiety having a λmax (i.e., absorption maximum) of at least 330 nm, the range of sensitivity of a halomethyl-1,3,5-triazine compound can be broadened.
Photopolymerizable compositions wherein the compounds of this invention can be used typically comprise (1) an unsaturated, free radical initiated, chain propagating addition polymerizable compound, (2) a compound of this invention, and (3) optionally, one or more fillers, binders, dyes, polymerization inhibitors, color precursors, oxygen scavengers, etc. The compounds of this invention should be present in an amount sufficient to initiate polymerization of said polymerizable compound. Suitable ratios of ingredients are as follows: for every 100 parts of polymerizable compound there can be from 0.005 to 10 parts of photoinitiator, from 0 to 200 parts of filler, from 0 to 200 parts of binder, and from 0 to 10 or more parts of dyes, polymerization inhibitors, color precursors, oxygen scavengers, etc, as may be needed for a particular use of the photopolymerizable compositions. Preferably, from 1 to 7.5 parts of the compound of this invention and from 25 to 150 parts of binder are used per 100 parts of polymerizable compound.
Unsaturated, free-radical initiated, chain-propagating addition polymerizable compounds suitable for the compositions of this invention include alkylene or polyalkylene glycol diacrylates, e.g., ethylene glycol diacrylate, diethylene glycol diacrylate, glycerol diacrylate, glycerol triacrylate, ethylene glycol dimethacrylate, 1,3-propanediol dimethacrylate, 1,2,4-butanetriol trimethacrylate, 1,4-cyclohexanediol diacrylate, pentaerythritol tetramethacrylate, pentaerythritol triacrylate, sorbitol hexacrylate; bis[1-(3-acryloxy-2-hydroxy)]-p-propoxyphenyl dimethylmethane, bis[1-(2-acryloxy)]-p-ethoxyphenyldimethylmethane, tris hydroxyethyl-isocyanurate trimethacrylate, the bis-acrylate and the bis-methacrylates of polyethylene glycols of molecular weight 200-500 and the like; unsaturated amides, e.g., methylene bis-acrylamide, methylene bis-methacrylamide, 1,6-hexamethylene bis-acrylamide, diethylene triamine trisacrylamide, beta-metha-crylaminoethyl methacrylate; vinyl esters such as divinyl succinate, divinyl adipate, divinyl phthalate, the preferred unsaturated compounds being pentaerythritol tetracrylate, bis[p-(3-acryloxy-2-hydroxypropoxy)phenyl]dimethylmethane, and bis[p-(2-acryloxyethoxy)phenyl]dimethylmethane. Mixtures of these esters can also be used as can mixtures of these esters with alkyl esters of acrylic acid and methacrylic acid, including such esters as methyl acrylate, methyl methacrylate, ethyl acrylate, isopropyl methacrylate, n-hexyl acrylate, stearyl acrylate, allyl acrylate, diallyl phthalate, and the like.
To prepare the photosensitive compositions of this invention, the components can be admixed in any order and stirred or milled to form a solution or uniform dispersion. Photosensitive elements can be made by coating a photosensitive composition on a suitable base or support and drying the coating. The dry thickness typically ranges from about 0.00005 to about 0.075 inch.
Suitable bases or supports for the photosensitive compositions include metals, e.g., steel and aluminum plates, sheets and foils, and films or plates composed of various film-forming synthetic or high polymers including addition polymers, e.g. vinylidene chloride, vinyl chloride, vinyl acetate, styrene, isobutylene polymers and copolymers and linear condensation polymers e.g., polyethylene terephthalate, polyhexamethylene adipate, polyhexamethylene adipamide/adipate.
The invention will be more specifically illustrated by the following examples. The value of λmax was measured in methanol, unless otherwise indicated.
EXAMPLE 1
This example illustrates preparation of 4-amino-[2'-ethyl-N'-(4,6-bistrichloromethyl)-1,3,5-triazin-2-yl)-carbamate]-N-[2'-ethyl-N"-(4,6-bis(trichloromethyl)-1,3,5-triazin-2-yl)-carbamate]-1,8-naphthalimide. To a solution containing 345 mg (1.1 mmol)-4-(2'-hydroxyethyl)amino-N-(2"-hydroxyethyl)-1,8-napthalimide in 50 ml dry toluene was added a solution of 1.17 g (3.4 mmol) 2,4-bis(trichloromethyl)-6-isocyanato1,3,5-triazine in 8 ml dry toluene. The reaction mixture was stirred under N 2 at 25° C. for six days. The solvent was removed by means of a rotary evaporator under reduced pressure and the residue was loaded upon a silica gel column (100 g packed in dichloromethane) and eluted with dichloromethane. The fractions containing the bright yellow compound were collected and the solvent was removed to yield 320 mg product (29% yield). The product had a melting point in excess of 260° C. and a λmax of 433 nm. The structure of this product is shown below. ##STR3##
EXAMPLE 2
This example illustrates preparation of N-[3,5-bis(dimethylaminobenzal)-4-piperidone]-[4,6-bis)trichloromethyl)-1,3,5-triazin-2-yl]carbamate. To a solution containing 2.20 g (5.6 mmol) 3,5-bis(dimethylaminobenzal)-4-piperidone and 20 drops di-n-butyltin dilaurate in 200 ml dry dichloromethane was added 2.0 g (5.6 mmol) 2,4-bis(trichloromethyl)-6-isocyanato-1,3,5-triazine. The reaction mixture was stirred at room temperature under a nitrogen atmosphere for 24 hours. The solvent was removed by means of a rotary evaporator under reduced pressure at room temperature. The residue was treated with 20 ml dichloromethane and the precipitate was filtered and dried to yield a 3.38 g product (84% yield). The product had a melting point in excess of 260° C. and a λmax of 460 nm. The structure of this product is shown below. ##STR4##
EXAMPLE 3
This example illustrates preparation of 2-[3',5'-bis(dimethylaminobenzal)-4'-piperidone]-4,6-bis(trichloromethyl)-1,3,5-triazine. A solution containing 414 mg (1.2 mmol) 3,5-bis(dimethylaminobenzal)-4-piperidone and 500 mg (1.2 mmol) 2,4,5-tris(trichloromethyl)-1,3,5-triazine in 150 ml methanol was heated to reflux for 62 hours. The reaction mixture was cooled to room temperature, and the precipitate was filtered and dried to yield 385.4 mg product (53% yield). The product had a melting point in excess of 260° C. and λmax of 455 nm. The structure of this product is shown below. ##STR5##
EXAMPLE 4
This example illustrates preparation of 2-(hydroxyethylrodanine-N"-methylbenzothiazole)-N'[4,6-bis(trichloromethyl)-1,3,5-triazin-2-yl]-carbamate. To a solution containing 90.8 mg (2.8 mmol) hydroxyethylrhodanine-N"-methylbenzothiazole in 50 ml dry toluene was added 158.3 mg (5.0 mmol) 2,4-bis(trichloromethyl)-6-isocyanato-1,3,5-triazine. The reaction mixture was stirred at room temperature under a nitrogen atmosphere for 45 hours. The solvent was removed by means of a rotary evaporator under reduced pressure at room temperature. The residue was treated with a small amount of dichloromethane and the resulting precipitate was filtered to yield 118.8 mg product (62% yield). The product had a melting point of 185°-189° C. and a λmax of 428 nm. The structure of this product is shown below. ##STR6##
EXAMPLE 5
This example illustrates preparation of N-[1'-pyrene]-N'-[4,6-bis(trichloromethyl)-1,3,5-triazin-2-yl]-urea. To a solution containing 500 mg (2.3 mmol) 1-aminopyrene and 20 drops di-n-butyltin dilaurate in 50 ml dry toluene was added 815 mg (2.3 mmol) 2,4-bis(trichloromethyl)-6-isocyanato-1,3,5-triazine. The reaction mixture was stirred at room temperature under a nitrogen atmosphere for 17.5 hours. The precipitate was filtered and dried to yield 1.11 gm product (84% yield). The product had a melting point of 244°-246° C. and a λmax of 340 nm. The structure of this product is shown below. ##STR7##
EXAMPLE 6
This example illustrates preparation of N-[6'-chrysene]-N'-[4,6-bis(trichloromethyl)-1,3,5-triazin-2-yl]-urea. To a solution containing 250 mg (1.0 mmol) 6-aminochrysene and 20 drops of di n-butyltin dilaurate in 50 ml dry toluene was added 365 mg (1.0 mmol) 2,4-bis(trichloromethyl)-6-isocyanto-1,3,5-triazine. The reaction mixture was stirred at room temperature under a nitrogen atmosphere for 17.5 hours. The precipitate was filtered and dried to yield 354 mg product (60% yield). The product had a melting point of 238°-241° C. and a λmax of 330 nm. The structure of this product is shown below. ##STR8##
EXAMPLE 7
This example illustrates the preparation of photosensitive elements using the halomethyl-1,3,5-triazines of this invention and the spectral response of the compounds in such elements.
A solution was prepared from 74.24 g azeotrope of 1-propanol and water (71.8% 1-propanol/28.2% water), 4.32 g pentaerythritol tetraacrylate ("SARTOMER" monomer SR-295, Arco Chemical Company), 5.64 g oligomer (prepared according to U.S. Pat. No. 4,228,232 and 60.9% in methyl ethyl ketone), 0.30 g triethylamine, and 14.88 g a 1:1 mixture of polyvinyl acetate-methylal resin ("FORMVAR" 12/85T, Union Carbide Corp.) and red pigment (Pigment Red 48, C.I. 15865) (9.4% by weight solution of the azeotrope). To 2.5 g of this solution was added 10-15 mg initiator, and the resulting solution shaken in the dark for 15 minutes. The solution was filtered through glass wool and coated onto a grained, anodized aluminum plate with a #12 Mayer bar. The plate was dried at 66° C. for 2 min and cooled to room temperature. To this coating was applied a topcoat formulation (prepared from 5.00 g carboxymethyl cellulose ether (CMC-7L), 0.26 g surfactant ("TRITON" X-100 (10% in water)), and 95.00 g water) with a #14 Mayer bar, and the topcoat carefully dried with a heat gun. The plates were exposed for 5 sec in air on top of a draw-down glass in a 3M Seventy unit equipped with a 2 kw photopolymer bulb through a √2, 21 step Stouffer step tablet. The plates were soaked in a developer solution prepared from 784.4 g deionized water, 16.7 g sodium metasilicate pentahydrate, 33.4 g 1-propanol, and 0.5 surfactant ("DOWFAX-2Al", Dow Chemical Company (45% solution in water)) for 15 sec and rubbed 10 times with a 4 in.×4 in. cotton pad. The relative sensitivities for triazines are shown in Table 2.
TABLE 2______________________________________Initiator Solid Step______________________________________Example 1 5Example 2 9Example 3 5Example 4 3Example 5 3Example 6 3______________________________________
Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention, and it should be understood that this invention is not to be unduly limited to the illustrated embodiments set forth herein. | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This is a divisional of application Ser. No. 10/357,128 filed on Feb. 3, 2003.
BACKGROUND OF INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to the field of post tension systems for strengthening concrete. More particularly, the invention relates to an improved anchor and method for reducing corrosion on the wire strands of a post-tension tendon.
[0004] 2. Background Art
[0005] Mono-strand tendons typically comprise a seven wire strand cable or tendon placed within a plastic or elastomeric sheath. A seven wire tendon is formed with six wires helically wrapped around a central core wire.
[0006] Wire cable corrosion is a significant concern in post tension systems. Such corrosion occurs when water, salt and other corrosive agents contact the metallic tendon materials. Tendon failure typically occurs due to water intrusion into the interstices between the tendon and is typically concentrated at tendon ends or anchors.
[0007] Such failure also occurs at portions of the tendon damaged segments caused during installation. The installation of tendons typically occurs in a rugged construction environment where the tendons can be damaged by equipment, careless handling and contact with various site hazards. When the elastomeric sheath is punctured, a water leak path contacting the wire tendon is established. The puncture must be patched to resist water intrusion between the sheath and tendon. The puncture and patch can create a discontinuity between the tendon and the sheath, and this discontinuity can impede proper installation and performance of the tendon.
[0008] One conventional technique for providing extra protection in the corrosive environments is to increase the thickness of the plastic sheath covering the tendon. A plastic sheath at least forty mils thick can be formed around the tendon resist abrasion and puncture damage. Although this approach provides incremental protection against leakage, a thicker sheath does not provide redundant protection to the tendon steel.
[0009] Another technique for providing extra protection in corrosive environments uses seals and grease-filled pockets for blocking water intrusion into the central tendon core. Oil or grease is pumped into the exposed tendon end to fill the interstices at the tendon ends, however this procedure does not protect the internal wire strands forming the tendon.
[0010] Another technique for resisting high corrosion environments is to specially coat or otherwise treat the individual wire strand with an electrostatic fusion-bonded epoxy to a thickness between one and five mils thick. Similar wire coating techniques use galvanized wire and other corrosion resistant wires within the multiple wire cables to form a corrosion resistant tendon. Significant effort has been made to create improved corrosion resistant materials compatible with the exterior sheaths and resistant to corrosion. Corrosion resistant materials typically have an affinity to metal and are capable of displacing air and water. Additionally, such materials are relatively free from tendon attacking contaminants such as chlorides, sulfides and nitrates. However, such tendons are expensive and the effectiveness of such corrosion resistant materials may not resist corrosion after the tendon is damaged.
[0011] Tendon corrosion typically occurs near the post-tension anchors because the outer sheath is removed from the wire tendon at such locations. To protect the bare wire from corrosion, protective tubes are connected to the anchor and are filled with the grease or other corrosion preventative material. This conventional practice is demonstrated by different post-tension systems. For example, U.S. Pat. No. 5,271,199 to Northern (1993) disclosed tubular members and connecting caps for attachment to an anchor. U.S. Pat. No. 5,749,185 to Sorkin (1998) disclosed split tubular members for attachment to and anchor and for installation over the tendon. U.S. Pat. No. 5,897,102 to Sorkin (1999) disclosed a tubular member having a locking surface for improving the connection to an anchor, and a cup member and extension for engagement on the other side of the anchor. U.S. Pat. No. 6,027,278 to Sorkin (2000) and U.S. Pat. No. 6,023,894 to Sorkin (2000) also disclosed a tubular member having a locking surface to improve the connection to an anchor. U.S. Pat. No. 6,098,356 to Sorkin (2000) disclosed attachable tubular members filled with corrosion resistant grease.
[0012] A need exists for an improved post-tension seal for preventing fluid intrusion into the inner part of a post-tension anchor. The system should be compatible with existing installation procedures and should resist the risk of water intrusion into contact with internal tendon wires.
SUMMARY OF THE INVENTION
[0013] The invention provides an anchor for engagement with a post-tension tendon. The anchor comprises an anchor base having an aperture oriented along a centerline for permitting insertion of the tendon therethrough, wherein the aperture has first and second surfaces each having different shape relative to said aperture centerline, and wherein the first and second surfaces continuously enlarge the size of the aperture from one side of the anchor base to another side of said anchor base. A sheath is engaged with the anchor base and includes a cylindrical extension having a contact end distal from the anchor base for contacting the tendon as the tendon is inserted through the cylindrical extension and the anchor base aperture.
[0014] In other embodiments of the invention, the cap includes a cap extension having a hollow interior for permitting passage of the tendon therethrough, and the exterior surface of the cap extension can be engagable with a pocketformer. A lock can retain the pocketformer in detachable engagement with the cap extension.
[0015] In another embodiment of the invention, a post-tension anchor system comprises a post-tension tendon having a sheath and inner wire strands, an anchor base having a shaped aperture for permitting insertion of the tendon therethrough, a sheath engaged 3 ′ with the anchor base wherein said sheath includes a cylindrical extension having a contact end distal from the anchor base for contacting the tendon as the tendon is inserted through the cylindrical extension and the anchor base aperture, and a cap for sealing the tendon within the anchor base aperture.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 illustrates a mono-strand cable enclosed with a first sheath.
[0017] FIG. 2 illustrates a second sheath around the first sheath.
[0018] FIG. 3 illustrates a first sheath closely formed to the cable exterior surface.
[0019] FIG. 4 illustrates a sectional view of an anchor base.
[0020] FIG. 5 illustrates detail of a cap having different thread combinations
[0021] FIG. 6 illustrates a ring cap for sealing the interior of an anchor base.
[0022] FIG. 7 illustrates a cap extension attached to a cap.
[0023] FIG. 8 illustrates a cap extension engaged with an anchor base.
[0024] FIG. 9 illustrates one embodiment of a cap extension.
[0025] FIG. 10 shows one embodiment of a cap having a removably engaged cap extension.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] The invention provides a unique system for providing a post tension system resistant to corrosion. Each tendon typically comprises an exterior sheath surrounding at least two strands formed with a material such as carbon steel.
[0027] FIG. 1 illustrates a sectional view wherein a mono-strand wire tendon 10 , formed with individual wire strands 12 about center wire 14 , is positioned within first sheath 16 . One or more wire strands 12 are helically wrapped about center wire strand 14 and form helical grooves on the exterior surface of cable 10 . Such helical grooves are cumulatively identified as shaped annulus 18 defining the space between tendon 10 and the interior cylindrical surface of first sheath 16 .
[0028] Because wire strands 12 are circular in cross-section, spaces between adjacent wire strands 12 and center wire 14 are cumulatively identified as cable interior interstices 20 . As shown in FIG. 1 , annulus 18 and interstices 20 are filled with corrosion resistant material 22 . Grease or another suitable material can be used for corrosion resistant material 22 to eliminate air pockets and to resist water intrusion into contact with wire strands 22 . By filling annulus 18 with a lubricant or corrosion resistant material 22 , the interior surface of first sheath 16 can be substantially cylindrical in one embodiment of the invention.
[0029] FIGS. 2 and 3 illustrate second sheath 26 formed about first sheath 16 . Annulus 28 is formed between second sheath 26 and first sheath 16 and is filled with a lubricant 30 to facilitate sliding movement therebetween. Lubricant 30 can comprise a corrosion resistant material similar to material 22 . Grease or another lubricant is place on the outer surface of the seven strand wire tendon adjacent to the elastromeric sheath to resist corrosion created by air and water infiltration between the tendon and the sheath. In FIG. 2 annulus 28 is substantially cylindrical. In FIG. 3 first sheath 16 is tightly formed about the exterior surface of tendon 10 and helical grooves, filled with corrosion resistant material, are formed in the exterior surface of the first sheath 16 . This feature preferably uses a material for first sheath 16 having a thickness less than then ten mils. Conventional membranes are typically twenty-five mils thick for regular systems and forty mils thick for high corrosion resistant, encapsulated systems. By providing a slim first sheath 16 about tendon 10 to create grooves in the exterior surface of first sheath 16 , corrosion resistant material 30 can be stored in annulus 28 to resist intrusion by water of other contamination into contact with first sheath 16 or tendon 10 .
[0030] FIG. 4 illustrates post-tension anchor comprising base 30 having shaped aperture 32 . Base 30 is formed with a cast metal material suitable for handling large compressive loads. Sheath 34 can be attached to base 30 in one embodiment of the invention and includes cylindrical extension 36 having a contact end 38 distal from base 30 . Contact end 38 is preferably at least four inches distal from base 32 , however shorter or longer lengths are possible within the usable scope of the invention. The inner surface of contact end 38 is preferably circular in cross-section for contacting the exterior surface of tendon 10 as tendon 10 is inserted through cylindrical extension 36 and base aperture 32 . Seal 40 can be positioned between contact end 38 and tendon 10 to restrict liquid intrusion into the inside of the cylindrical extension 36 .
[0031] Cap 42 has threads 44 engaged with threadform 46 on sheath 34 . Cap 42 includes shaped end 48 configured to facilitate rotatable engagement and disengagement of cap 42 relative to sheath 34 . As illustrated, shaped end 48 can be a polygonal configuration such as a hexagonal or other shaped form suitable for engagement with a socket wrench. In other embodiments of the invention shaped end can be configured to be engagable with different drive mechanisms such as screwdrivers, wrenches, pliers and other devices. Grease 50 can be positioned within cap 42 to seal the end of tendon 10 placed therein.
[0032] In one embodiment of the invention threads 44 can include a double start lead to facilitate attachment of cap 42 to sheath 34 . The double start lead can comprise threads having different sizes and pitches to provide different make-up characteristics. FIG. 5 illustrates cap 42 and base 30 in expanded position and displays cap 42 having different threadforms 52 and 54 for selective engagement with correlating threadforms on sheath 34 . As shown in FIG. 6 , cap 42 can also have indicator tab 56 which flares upwardly when cap 42 is fully engaged with base 30 . Such feature provides a visual indication of full engagement and an effective watertight seal between cap 42 and base 30 . As also can be seen in FIG. 5 , the extension 36 , having seal 40 therein at the distal end 38 is formed integrally with the sheath 34 .
[0033] FIG. 4 illustrates the installation of wedges 58 in contact with tendon 10 and base 30 . Wedges 58 are installed into such position after cap 42 has been removed from engagement with sheath 34 and base 30 . The invention permits wedges 58 to be installed directly against first sheath 16 or second sheath 26 of cable 10 so that wedges 58 contact wire strands 12 with minimal disruption to sheaths 16 or 26 . This feature of the invention reduces the amount of wire strands 12 requiring field repair and sealant and significantly reduces installation time and possibility of corrosion base upon failure of such field repairs. Because cap 42 is reusable, cap 42 can be reinstalled with base 30 to seal the interior of base 30 . Alternatively, another structure such as ring cap 60 can be positioned over tendon 10 to seal the interior of base 30 as shown in FIG. 6 .
[0034] FIG. 7 illustrates in exploded detail cap extension 62 integrated within cap 42 . Cap extension 62 can also comprise a separate component attached to cap 42 with snap connections, tape, threadforms, or other techniques. Cap extension 62 provides the function of extending the useful length of cap 42 , thereby permitting a longer length of tendon (not shown) to extend beyond wedges 58 within base 30 as illustrated in FIG. 8 . Extension end 64 can be open as illustrated to permit the passage of tendon 10 therethrough or can be closed. Lock nut 66 having threadform 68 can be engaged with threadform 70 on cap extension 62 to retail a pocketformer or other apparatus or to provide a closure for the open end of extension end 64 .
[0035] An example of a cap extension 62 is shown in FIG. 10 as a separate element coupled to the cap by means of threads 73 such that the extension may be selectively engaged with the cap 42 .
[0036] FIG. 9 illustrates another embodiment of cap extension 72 wherein extension tube 74 has threadform 76 and seal 78 . Lock ring 80 has threadform 82 for engagement with base 30 and for retaining extension tube 74 in a fixed position relative to base 30 . The combination of lock ring 80 and extension tube 74 significantly facilitates manufacture of extension 72 .
[0037] The invention provides superior anti-corrosion protection through the entire tendon length and especially near the point of engagement with post-tension anchors. The sheath materials for tendon 10 can be selected from material classes such as nylon, polymers, metals, or other organic or inorganic or mineral or synthetic materials. An outer second sheath can be formed with a tough material resistant to punctures and stretching damage, while an interior first sheath can be formed with another material for retaining the corrosion resistant material.
[0038] The configuration of base 30 permits installation and tensioning of tendon 10 without removal of sheath 16 from tendon 10 at the location of base 30 . By avoiding the disturbance of the manufactured sheath 16 , the most sensitive point of corrosion is completely eliminated. The configuration of the caps and pocket formers described in cooperation with base 30 significantly reduces labor time and cost and provides superior reliability during installation. Such reliability reduces field damage to post tension components and the possibility of corrosion resulting from such damage, and eliminates the need for costly and unreliable field repairs.
[0039] Although the invention has been described in terms of certain preferred embodiments, it will become apparent to those of ordinary skill in the art that modifications and improvements can be made to the inventive concepts herein without departing from the scope of the invention. The embodiments shown herein are merely illustrative of the inventive concepts and should not be interpreted as limiting the scope of the invention | 4y
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The present invention concerns a fixing device for wire cable trays.
BACKGROUND OF THE INVENTION
In the manner known in the art, wire cable trays take the form of a channel consisting of wire mesh. This mesh includes longitudinal wires, usually called warp wires, and transverse wires called weft wires. The warp wires are rectilinear, or substantially rectilinear, and are welded to the weft wires. The latter generally have an overall U-shape and are disposed with a regular pitch along the warp wires. Thus, overall, a cable tray includes three panels, namely a bottom panel and two lateral panels.
Such cable trays are commonly used to accommodate, support and protect flexible conduits of diverse kinds: electrical cables (low-voltage or high-voltage), data transmission cables (telephone, optical fiber, etc.), fluid pipes, etc.
It is sometimes required to group cables together in a cable tray to form a bundle of cables in the cable tray and to fix this bundle into the cable tray. A cable tie is then used, for example, which surrounds the cables concerned and a warp wire of the cable tray.
It can also be required to fix an accessory in the cable tray. The classic solution is then to bolt it into the bottom of the cable tray or to a lateral flange.
SUMMARY OF THE INVENTION
The present invention has the object of providing a device for fixing elements—cable bundle, accessory, sundry objects, etc.—into a cable tray. This device can preferably on the one hand be fitted to numerous types of cable tray and on the other hand be mounted quickly, without ancillary parts (bolts, etc.) and without tools. This device can advantageously also be fitted on site as required.
To this end, the invention proposes a fixing device for wire cable trays including on the one hand longitudinal warp wires and on the other hand transverse weft wires, having a base with a mounting face by which it is mounted on the cable tray and fixing means.
According to the invention, this fixing device includes:
at least one trough-shaped longitudinal housing intended to receive a first wire of the cable tray (warp wire or weft wire) and produced in the mounting face, at least one bearing surface undercut relative to the mounting face, said surface extending perpendicularly to the longitudinal housing and being disposed parallel to the back of the longitudinal housing at an intermediate level between the back of that housing and the mounting face, and at least one transverse cut-out corresponding to each intersection between a longitudinal housing and a bearing surface, this cut-out extending from one edge of the mounting face to a longitudinal housing.
This device can easily be fitted, without tools, to a cable tray. A first wire of the cable tray (warp wire or weft wire) bears on the bottom of the trough-shaped housing while a second wire of the cable tray (weft wire or warp wire) bears on the bearing surface, thereby retaining the device with a clamping force depending on the distance between the bottom of the trough and the bearing surface. Here mounting is effected by bearing on two faces (edges) of wires of the cable tray that are welded together. Thus the diameter of the wires used is of no consequence.
In a first embodiment, a fixing device of the invention has a plurality of similar longitudinal housings disposed parallel to each other at a regular pitch.
In a second embodiment, a fixing device of the invention includes a plurality of similar transverse cut-outs disposed parallel to each other at a regular pitch.
By adapting to the shapes in which cable trays are produced, these two embodiments offer improved retention to enable the fixing of an accessory on which a greater or lesser load is exerted.
When there are both a number of longitudinal housings and a number of transverse cut-outs, the pitch between the longitudinal housings is preferably the same as that between the transverse cut-outs. The fixing device can then be mounted in two different mutually perpendicular orientations on the cable tray.
For improved retention on the cable tray on which the device of the invention is mounted, a boss can be produced on the bearing surface. Fitting is then effected by clipping.
In one embodiment of the device of the invention the base is produced in a molded synthetic material. In this case, this fixing device is associated for example with a cable retaining device. One such cable retaining device is described in U.S. Pat. No. 7,107,653, for example.
In another embodiment the base of the device of the invention is produced in sheet metal cut and bent to shape. The fixing means of this device then take the form of circular bores and/or oblong holes produced in the sheet.
The present invention also concerns an embodiment of a fixing device including a single trough-shaped longitudinal housing, a single transverse cut-out and two bearing surfaces disposed on opposite sides of the longitudinal housing. This particularly advantageous embodiment places the device at the intersection of a warp wire and a weft wire.
Finally, the present invention also concerns an assembly including on the one hand a section of cable tray having longitudinal warp wires and U-shaped transverse weft wires and on the other hand a fixing device as described above, this assembly being characterized in that the base of the fixing device is inside the section of cable tray, that is to say between the branches of the U-shape of the weft wires, and in that each longitudinal housing receives a warp wire. In this advantageous embodiment, the fixing device is mounted by positioning said device in the cable tray and sliding it along a warp wire. This is advantageous because if cables have already been placed in the section of cable tray, the movement to fix the fixing device is parallel to the cables already in place and can therefore be performed easily. Movements when fixing a cable tray to a support or the like generally entail sliding along a weft wire and thus in a direction perpendicular to any cables in the cable tray.
BRIEF DESCRIPTION OF THE DRAWINGS
Details and advantages of the present invention will emerge more clearly from the following description, given with reference to the appended diagrammatic drawings, in which:
FIG. 1 represents diagrammatically a fixing device of the invention mounted in a wire cable tray,
FIG. 2 is a view of the fixing device from FIG. 1 in cross section,
FIG. 3 is a view in longitudinal section on the section plane III-III in FIG. 2 during mounting of the fixing device on the cable tray,
FIG. 4 is a view from below corresponding to the mounting step from FIG. 3 ,
FIG. 5 is a perspective view of a different embodiment of a fixing device mounted in a wire cable tray,
FIG. 6 is a view in section taken along the line VI-VI in FIG. 5 ,
FIG. 7 is a perspective view showing two fixing devices of another embodiment mounted in a cable tray, and
FIG. 8 is a perspective view from below of another embodiment of a fixing device of the invention mounted in a wire cable tray.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 to 4 represent a first embodiment of a fixing device of the invention. This device includes on the one hand a base 2 and a cable retaining device 4 . It is produced in one piece, for example by molding a synthetic material.
The base 2 is intended to enable fixing of the fixing device of the invention to a section of wire cable tray 6 . In the conventional way, and as represented in the drawings, this cable tray is gutter-shaped and includes longitudinal wires 8 called warp wires and transverse wires 10 called weft wires. The warp wires 8 are rectilinear (except for the edge wires in the embodiment represented, which are nevertheless substantially rectilinear). The weft wires 10 are U-shaped. The section of cable tray 6 therefore has a bottom panel 12 and two lateral panels 14 . It is assumed here that the bottom panel 12 is at the bottom of the lateral panels. This bottom panel 12 is disposed in a substantially horizontal plane whereas the lateral panels 14 extend substantially vertically. Such an orientation is usual for a section of cable tray. Other orientations can nevertheless be envisaged, for example with the bottom panel 12 disposed vertically or inclined.
The base 2 has a mounting face 16 which, in a preferred embodiment, is a substantially plane face. A trough-shaped housing 18 is produced in the mounting face 16 . This housing 18 forms a groove extending the entire length of the mounting face 16 intended to receive a wire of the section of cable tray, a warp wire 8 in the orientation chosen for FIGS. 1 to 4 . Here this housing 18 is considered to extend longitudinally. There is thus defined an orientation that corresponds to the orientation of the section of cable tray 6 represented, but as will emerge hereinafter, the fixing device of the invention can equally be fixed to the section of cable tray 6 oriented so that the housing 18 extends transversely relative to said section.
FIGS. 1 and 2 show the trough shape of the housing 18 . The back of this housing, which in the chosen orientation is at the top of the housing 18 , preferably has a radius of curvature adapted to the diameters of the wires intended to be placed in the housing 18 . If warp or weft wires with different diameters are to be housed in the housing 18 , the latter will preferably have a radius of curvature corresponding to the larger wire radius. The housing 18 having another shape can nevertheless be envisaged: it could be V-shaped, for example, or some other shape.
The base 2 also has a bearing surface 20 set back relative to the mounting face 16 . This bearing surface 20 extends perpendicularly to the housing 18 . It is parallel to the back line 22 of the housing 18 . In the embodiment shown here, which is a preferred embodiment, it is also parallel to the mounting face 16 .
The bearing surface 20 is between the mounting face 16 and the back line 22 of the housing 18 . The distance between the bearing surface 20 and the back line 22 (which is parallel to it) is a few tenths of a millimeter.
A transverse cut-out 24 provides access from the mounting face 16 to the bearing surface 20 . This cut-out is seen in FIG. 3 in particular. The bearing surface 20 being intended to serve as a support for a wire of the cable tray on which the fixing device is mounted, the transverse cut-out 24 enables that wire to pass from the mounting face 16 to the bearing surface 20 . Thus this transverse cut-out 24 opens into the mounting face 16 . In the embodiment represented in FIGS. 1 to 4 , the transverse cut-out 24 forms with the housing 18 a cross. This transverse cut-out 24 extends either side of the longitudinal housing 18 to the corresponding edge of the mounting face 16 of the base.
As FIG. 3 shows, this transverse cut-out 24 is L-shaped. One branch of this L-shape is perpendicular to the mounting face 16 while the other branch of this L-shape is parallel to the bearing surface 20 . Accordingly, in order to bear on the surface 20 , a wire of the cable tray, a weft wire 10 in FIGS. 1 to 4 , is first placed parallel to the mounting face 16 and perpendicular to the longitudinal housing 18 . This weft wire 10 then penetrates through the transverse cut-out 24 in the base 2 , after which it is slid parallel to the mounting face 16 , parallel to the bearing surface 20 , to take up a position on this undercut bearing surface 20 .
Arrows in FIG. 3 show the mounting of the fixing device on the section of cable tray 6 . Thus the base 2 is first positioned at an intersection between a warp wire 8 and a weft wire 10 so that the cross formed by the housing 18 and the transverse cut-out 24 coincides with the intersection of the wires of the cable tray where the fixing device is to be placed ( FIG. 4 ). In the situation represented, the longitudinal housing 18 faces a warp wire 8 while the transverse cut-out 24 faces a weft wire 10 .
The base 2 is then moved vertically downward (in the chosen orientation, see above) indicated by the first arrow 26 in FIG. 3 . The warp wire 8 then comes to rest on the back of the longitudinal housing 18 ( FIG. 3 position). The base 2 is finally pushed in the longitudinal direction, as indicated by the second arrow in FIG. 3 . The weft wire 10 then slides on the bearing surface 20 , for example until it abuts on the back of the cut-out, as shown in FIG. 1 . This movement is guided by the warp wire 8 sliding in its housing 18 .
The fixing device of the invention, once mounted, is retained on the one hand by the back of the housing 18 bearing on the warp wire 8 and on the other hand by the weft wire 10 bearing on the bearing surfaces 20 . There can be a slight clamping effect here to retain the device of the invention on the section of cable tray 6 by adapting the distance between the back line 22 of the housing 18 and the bearing surfaces 20 . This device is then retained thanks to this clamping effect without having to use any tools. Moreover, if cables (not shown) are present in the section of cable tray 6 , mounting can be effected anyway because, during mounting, fixing is effected by a longitudinal movement, which is parallel to the cables. Because of this, the cables do not greatly impede the fixing of the device.
In the embodiment of FIGS. 1 to 4 , the base 2 is produced in a synthetic material having relatively high elasticity (compared to sheet metal). A boss 30 is then provided for improved retention of the fixing device (or its base 2 ) to the section of cable tray 6 . This boss 30 is produced near the edge of the bearing surface 20 on the same side as the transverse cut-out 24 . It is positioned to leave sufficient room between it and the back of the transverse cut-out 24 to accommodate the wires of greater diameter intended to bear on the bearing surfaces 20 .
The cable retaining device 4 is shown diagrammatically in FIGS. 1 to 4 as a ring. This ring is preferably covered, but this opening enabling introduction of cables is not represented in the drawings. This is a retaining device like that described in U.S. Pat. No. 7,107,653, for example. Such a device enables rapid placement of cables to retain them. This retention is furthermore reversible. The device can thus be opened and closed at will to add or remove a cable.
FIGS. 5 and 6 show another embodiment of a fixing device of the invention. This embodiment is in sheet metal. For this and subsequent embodiments, elements similar to those of the first embodiment of FIGS. 1 to 4 have the same references as in those figures.
On the device of FIGS. 5 and 6 , there is a mounting face 16 with two longitudinal housings 18 and a transverse cut-out 24 for each of the housings 18 . The mounting face 16 is the lower face of the fixing device and is not visible in FIG. 5 . The device is produced from sheet metal by cutting and pressing. Thus the formation of the housings 18 in the mounting face 16 produces a rib on the face of the sheet opposite the housings 18 .
The two transverse cut-outs 24 extend in each case from a longitudinal housing 18 to an edge of the mounting face 16 . They are aligned and thus correspond to the same weft wire 10 (or warp wire 8 ). Each transverse cut-out 24 here defines a tongue 32 one face of which, that opposite the mounting face 16 , is part of the bearing surface 20 .
To enable the fixing of any accessory, the fixing device includes fixing means which, in the embodiment shown (see FIG. 5 ), are two bores 34 of circular shape.
To mount this fixing device on the section of cable tray 6 as shown in FIG. 5 , the mounting face 16 is placed on the bottom panel 12 of the section of cable tray 6 so that the longitudinal housings 18 face two warp wires 8 . The fixing device is introduced via the interior of the section of cable tray (the interior corresponding to the space between the branches of the U-shape of the cable tray) and the concave face of the housings 18 is oriented toward the exterior of the section of cable tray. A weft wire 10 is level with the transverse cut-outs 24 , more particularly where the transverse cut-outs open into the mounting face 16 . The warp wires 8 then take their place in the housings 18 . The fixing device is then slid longitudinally so that the weft wire 10 passes over the tongues 32 and thus comes to bear on the corresponding bearing surface 20 . This latter movement is guided by the warp wires 8 sliding in the longitudinal housings 18 .
In this sheet metal embodiment, having only one longitudinal housing 18 and only one transverse cut-out 24 can be envisaged. There are then two bearing surfaces 20 disposed on opposite sides of the longitudinal housing 18 . Thus the device can be mounted at the crossover of a warp wire and a weft wire of the section of cable tray.
FIG. 7 shows another embodiment of a fixing device of the invention. Two identical fixing devices are represented in this figure. This figure shows how the same fixing device of the invention can be fixed with two different orientations, either inside a section of cable tray 6 or outside it.
The fixing device represented here is also produced in sheet metal. It includes a base 2 having a mounting face 16 and a fixing plate 36 . This fixing device is also produced by pressing and bending sheet metal. The fixing plate 36 is provided with bores 38 of circular shape and oblong holes 38 ′.
The mounting face 16 of this fixing device includes a longitudinal housing 18 and six transverse cut-outs 24 . The transverse cut-outs 24 are regularly spaced with a regular pitch, for example a pitch of 50 mm. This pitch corresponds to the pitch between two adjacent warp wires. The pitch between two weft wires is twice that between the warp wires, i.e. 100 mm. These numerical values are given by way of nonlimiting example, but correspond to values currently found on some cable trays. The fact of having warp wires and weft wires with separation pitches of which one is a multiple of the other enables mounting of the fixing device in the two positions shown in FIG. 7 . In one mounting position, the longitudinal housing 18 receives a weft wire 10 , whereas in the other mounting position it receives a warp wire 8 . In the first mounting the fixing device is mounted on a weft wire and six warp wires whereas in the second mounting position the fixing device is mounted on one warp wire and three weft wires.
This mounting in two different directions is illustrated by the embodiment represented in FIG. 7 , but it is clear that the other embodiments described above, and many other embodiments of the invention, also enable such mountings on the same cable tray.
FIG. 8 shows by way of illustration another embodiment in sheet metal. The fixing device of this embodiment includes three longitudinal housings 18 and is intended to be mounted on two weft wires and six warp wires or three warp wires and three weft wires.
Of course, embodiments with a plurality of longitudinal housings 18 and/or a plurality of transverse cut-outs 24 can be produced for bases of synthetic material fixing devices of the type shown in FIGS. 1 to 4 .
The fixing devices described above can be considered as universal fixing devices because each can be used on cable trays produced with wires of different diameters: they can be used on a cable tray using wires of different diameters, but they can also be used on two different cable trays produced with wires of different diameters. Furthermore, fixing devices whose mounting face includes a longitudinal housing and a transverse cut-out can adapt to any intersection of two wires of a cable tray and can be mounted at will essentially inside the cable tray or outside it. A device of the invention thus enables fixing of an accessory intended to be located inside a cable tray or outside it.
Note further that the mounting of these devices is easy and can be effected without tools. These sections can be mounted on demand on site when fitting a cable tray with no auxiliary parts, such as bolts or the like.
Even if a device of the invention can be produced in bent and cut sheet metal, it is a device offering good accuracy and high stiffness. A molded synthetic material embodiment also provides good accuracy. It has the advantage of not being aggressive to cables intended to be placed in the cable tray.
The devices described are essentially intended to be mounted in a section of cable tray but mounting versions with a plurality of longitudinal housings and/or a plurality of transverse cut-outs between two sections of cable tray can also be envisaged.
The present invention is not limited to the embodiments described above by way of nonlimiting example and to the variants referred to. It concerns equally all variants evident to the person skilled in the art within the scope of the following claims. | 4y
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BACKGROUND OF THE INVENTION
This invention relates to a variable displacement compressor of a piston type.
Such a variable displacement compressor comprises a piston reciprocally driven in a cylinder bore. The piston has suction and compression strokes which are alternatively repeated to compress a gaseous fluid such as a refrigerant gas. During the suction stroke, the gaseous fluid is sucked into the cylinder bore through a suction port and a suction chamber of the compressor. During the compression stroke, the gaseous fluid id compressed in the cylinder bore into a compressed fluid. The compressed fluid is discharged from the cylinder bore to a discharge chamber of the compressor. In this type of a variable displacement compressor, it is assumed that the compressed fluid has pressure pulsation when the compressed fluid has a flow rate which is relatively low.
For example, a variable displacement compressor is revealed in U.S. Pat. No. 6,257,848, filed on Aug. 20, 1999, by Kiyoshi Terauchi, for assignment to the present assignee, based on Japanese Patent Application No. 153,853 of 1999 filed on Jun. 1, 1999. The variable displacement compressor is provided with an opening control valve disposed in a main channel between the suction port and the suction chamber for variably controlling an opening area of the main channel.
Referring to FIG. 1, description will be made as regards the opening control valve included in a variable displacement compressor in an earlier technology. The opening control valve has a valve body 4 for opening and closing a main channel 3 between a suction port 1 and a suction chamber 2 , a cavity 5 for slidably receiving the valve body 4 , a return spring 6 arranged within the cavity 5 , a communication path 7 for establishing communication between the cavity 5 and the suction chamber 2 , and a communication path 8 formed in the valve body 4 . The suction port 1 has a downstream end provided with a valve seat 1 a for receiving the valve body 4 to be brought into contact therewith.
The above-mentioned variable displacement compressor is operable at a variable flow rate. At a high flow rate, a pressure difference between the suction port 1 and the suction chamber 2 is great. Therefore, a pressure difference between the suction port 1 and the cavity 5 communicating with the suction chamber 2 through the communication path 7 is great also. Thus, a difference between a primary pressure and a secondary pressure on primary and secondary sides of the valve body 4 is great. As a consequence, the valve body 4 is separated from the valve seat 1 a to be retreated within the cavity 5 with the spring 6 compressed to a large extent. In this event, the opening area of the main channel 3 is increased. A refrigerant gas introduced from the suction port 1 passes through the main channel 3 increased in opening area to flow into the suction chamber 2 . Then, the refrigerant gas presses and opens a suction valve 9 to flow into a cylinder bore 10 .
At a low flow rate, the pressure difference between the suction port 1 and the suction chamber 2 is small. Therefore, the pressure difference between the suction port 1 and the cavity 5 communicating with the suction chamber 2 through the communication path 7 is small also. Thus, the difference between the primary pressure and the secondary pressure on the primary and the secondary sides of the valve body 4 is small. As a consequence, the valve body 4 compresses the spring 6 to a less extent so that the valve body 4 approaches the valve seat 1 a . In this event, the opening area of the main channel 3 is reduced. A part of the refrigerant gas introduced from the suction port 1 flows into the suction chamber 2 through the main channel 3 reduced in opening area. On the other hand, the other part of the refrigerant gas flows through the communication path 8 formed in the valve body 4 , the cavity 5 , and the communication path 7 into the suction chamber 2 . The refrigerant gas flowing into the suction chamber 2 presses and opens the suction valve 9 to flow into the cylinder bore 10 .
At a very low flow rate, the pressure difference between the suction port 1 and the suction chamber 2 is very small. Thus, the primary pressure and the secondary pressure on the primary and the secondary sides of the valve body 4 are substantially balanced with each other, i.e., substantially equal to each other. Under a weak urging force of the spring 6 restored into a substantially unloaded condition, the valve body 4 is very close to the valve seat 1 a to substantially close the main channel 3 . The refrigerant gas introduced from the suction port 1 passes through the communication path 8 formed in the valve body 4 , the cavity 5 , and the communication path 7 to flow into the suction chamber 2 .
At the low flow rate, pressure pulsation of the refrigerant gas caused by self-induced vibration of the suction valve 9 is attenuated during passage through the main channel 3 reduced in opening area or through the communication path 7 and the communication path 8 of the valve body 4 . This suppresses a vibration noise of an evaporator produced by the pressure pulsation propagating from the suction port 1 through an external cooling circuit to the evaporator.
The opening control valve disclosed in the above-mentioned publication is disadvantageous in the following respect. At the very low flow rate, the substantial balance between the primary pressure and the secondary pressure on the primary and the secondary sides of the valve body 4 is lost in a suction stroke as a result of pressure loss during passage of the refrigerant gas through the communication path 8 of the valve body 4 . On the other hand, in a compression stroke, the refrigerant gas does not flow through the communication path 8 of the valve body 4 so that the substantial balance between the primary pressure and the secondary pressure on the primary and the secondary sides of the valve body 4 is recovered. Under the circumstances, every time when the suction stroke and the compression stroke are alternately repeated, the valve body 4 repeatedly performs very fine movement alternately towards the cavity 5 and towards the valve seat 1 a . Such repetition of fine movement of the valve body 4 induces the pressure pulsation of the refrigerant gas, which in turn causes a noise to be produced.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a variable displacement compressor of a piston type, which is capable of reducing generation of a noise resulting from repetition of fine movement of a valve body of the opening control valve at a very low flow rate.
Other objects of the present invention will become clear as the description proceeds.
According to an aspect of the present invention, there is provided a variable displacement compressor of a piston type, which comprises a suction port, a suction chamber, a main channel communicating the suction port with the suction chamber, a valve body movably placed adjacent to the main channel for variably controlling an opening area of the main channel, a fluid damper coupled to the valve body for damping vibration of the valve body, and a bypass channel formed outside of the fluid damper to communicate the suction port with the suction chamber.
According to another aspect of the present invention, there is provided a variable displacement compressor of a piston type, which comprises a suction port, a suction chamber, a main channel communicating the suction port with the suction chamber, a valve body movably placed adjacent to the main channel for variably controlling an opening area of the main channel, a fluid damper coupled to the valve body for damping vibration of the valve body, a bypass channel formed outside of the fluid damper to communicate the suction port with the suction chamber, a compressor housing defining the suction port and the suction chamber, and a valve case fixed to the compressor housing and defining the main channel, the valve body being movably held by the valve case, the fluid damper being formed between the valve case and the valve body.
According to still another aspect of the present invention, there is provided a variable displacement compressor of a piston type, which comprises a suction port, a suction chamber, a main channel communicating the suction port with the suction chamber, a valve body movably placed adjacent to the main channel for variably controlling an opening area of the main channel, a fluid damper coupled to the valve body for damping vibration of the valve body, a bypass channel formed outside of the fluid damper to communicate the suction port with the suction chamber, a compressor housing defining the suction port and the suction chamber, and a valve case fixed to the compressor housing and defining the main channel, the valve body being movably held by the valve case. In the variable displacement compressor, the suction port is cylindrical and extends in a predetermined direction, the valve case being placed in the suction port and having a cylindrical wall extending in the predetermined direction and a bottom wall connected to a suction chamber side of the cylindrical wall, the main channel being formed to the cylindrical wall, the valve body being fitted inside the cylindrical wall to be movable in the predetermined direction, the return spring being interposed between the valve body and the bottom wall to urge the valve body towards an open end of the cylindrical wall, the valve case having a stopping portion for stopping the valve body against the return spring, the fluid damper being formed between the valve body and the bottom wall to serve in the predetermined direction.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a sectional view of a variable displacement compressor in an earlier technology;
FIG. 2 is a sectional view of a variable displacement compressor according to an embodiment of this invention;
FIG. 3A is an enlarged sectional view of a main portion of the variable displacement compressor illustrated in FIG. 2;
FIG. 3B is a sectional view taken along a line IIIB—IIIB in FIG. 3A;
FIG. 4A is a sectional view of a modification of the main portion illustrated in FIGS. 3A and 3B;
FIG. 4B is a sectional view taken along a line IVB—IVB in FIG. 4A;
FIG. 5A is a sectional view of another modification of the main portion illustrated in FIGS. 3A and 3B;
FIG. 5B is a sectional view taken along a line VB—VB in FIG. 5A; and
FIGS. 6A through 6D are sectional views for describing various structures of fixing an opening control valve to a cylinder head of the variable displacement compressor.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 2, description will be made as regards a variable displacement compressor according to an embodiment of the present invention.
The shown variable displacement compressor is for compressing a refrigerant gas and comprises a casing 11 , a main shaft or spindle 12 accommodated in the casing 11 , and a front housing 13 fixed to one end of the casing 11 . The spindle 12 has one end extending outward through the front housing 13 to be connected through an electromagnetic clutch 14 to an external driving source (not shown).
Within the casing 11 , a plurality of cylinder bores 15 are arranged with a space left from one another in a circumferential direction. Each cylinder bore 15 receives a piston 16 slidably inserted therein. The piston 16 is connected to the spindle 12 through a crank mechanism 17 and, following the rotation of the spindle 12 , performs reciprocal movement within the cylinder bore 15 . The piston 16 has a stroke variably controlled via the crank mechanism 17 .
The casing 11 has the other end to which a cylinder head 19 is fixed through a valve mechanism 18 . The valve mechanism 18 has a suction hole 20 , a discharge hole 21 , a suction valve 22 , and a discharge valve 23 which are faced to each cylinder bore. A combination of the casing 11 , the front housing 13 , and the cylinder head 19 will be referred to as a compressor housing.
The cylinder head 19 is provided with a suction chamber 24 communicating with the suction hole 20 and a discharge chamber 25 communicating with the discharge hole 21 . The suction chamber 24 communicates with a suction port 26 extending vertically in a predetermined direction or a vertical direction. The suction port 26 is connected to a low-pressure side of a refrigerating circuit known in the art. The discharge chamber 25 communicates with a discharge port 27 . The discharge port 27 is connected to a high-pressure side of the refrigerating circuit. At a downstream end of the suction port 26 , an opening control valve 30 is disposed.
Referring to FIGS. 3A and 3B, the opening control valve 30 comprises a cylindrical valve case 31 having a closed end at the bottom and an open end at the top. The valve case 31 has a cylindrical wall 311 extending in the vertical direction between the bottom and the top. The cylindrical wall 311 has a small-inner-diameter portion 311 a near to the open end and a large-inner-diameter portion 311 b near to the closed end. The valve case 31 further has a bottom wall 312 connected to the cylindrical wall 311 and forming the closed end. The large-inner-diameter portion 311 b has a peripheral wall provided with an opening adjacent to the small-inner-diameter portion 311 a . The opening defines a main channel 32 extending between the suction port 26 and the suction chamber 24 . The bottom wall 312 of the valve case 31 is provided with a small hole 33 penetrating therethrough.
A valve body 34 in the form of a cylinder having one end as a closed end is fitted inside the large-inner-diameter portion 311 b of the valve case 31 to be movable in the vertical direction. The valve body 34 has a bottom wall 34 a faced to the open end of the valve case 31 . The small-inner-diameter portion 311 a has an end face confronting the bottom wall 34 a and defining a valve seat 35 . Irrespective of an axial position of the valve body 34 within the large-inner-diameter portion 311 b , the valve body 34 is always brought into sliding contact with a lower part of the large-inner-diameter portion 31 b which is nearer to the bottom wall 31 c than the main channel 32 . A combination of the valve body 34 and the above-mentioned lower part defines a chamber 36 . Within the chamber 36 , a return spring 37 is arranged to urge the valve body 34 towards the valve seat 35 .
A combination of the valve body 34 , the above-mentioned lower part of the large-inner-diameter portion 311 b , the return spring 37 , and the small hole 33 formed in the bottom wall 31 forms a fluid damper 38 . The valve body 34 forms a piston of the fluid damper 38 . The fluid damper 38 follows long-cycle variation in external force but does not follow short-cycle variation in external force. Therefore, if an external force varying in a long cycle is applied to the valve body 34 , the valve body 34 is moved following the variation in external force. On the other hand, if an external force varying in a short cycle is applied to the valve body 34 , the valve body 34 does not move following the variation in external force.
Outside of the fluid damper 38 , more specifically, in a peripheral wall of the small-inner-diameter 311 a of the valve case 31 , a plurality of bypass holes 39 are formed adjacent to the main channel 32 .
The valve case 31 has a flange 313 formed at the open end thereof. The flange 313 is provided with a protrusion 40 extending throughout an entire circumference thereof. On the other hand, the suction port 26 has a surrounding wall provided with a recess 41 extending throughout the entire circumference. The opening control valve 30 is disposed at the downstream end of the suction port 26 with the open end of the valve case 31 faced to an upstream side of the suction port 26 . The opening control valve 30 is fixed to the cylinder head 19 by press-fitting the protrusion 40 formed on the flange 31 d into the recess 41 formed in the surrounding wall of the suction port 26 .
In the variable displacement compressor, the piston 16 performs reciprocal movement within the cylinder bore 15 following the rotation of the spindle 12 . A refrigerant gas circulating from the low-pressure side of the external refrigerating circuit passes through the suction port 26 , the main channel 32 , the suction chamber 24 , the suction hole 20 , and the suction valve 22 to be sucked into the cylinder bore 15 . Then, the refrigerant gas is compressed in the cylinder bore 15 and passes through the discharge hole 21 , the discharge valve 23 , the discharge chamber 25 , and the discharge port 27 to be delivered to the high-pressure side of the external refrigerating circuit.
In the manner known in the art, the crank mechanism 17 variably controls the stroke of the piston 16 . The variable displacement compressor has a discharge flow rate variably controlled in response to the stroke of the piston 16 .
At a high flow rate, a pressure difference between the suction port 26 and the suction chamber 24 is great. Therefore, a pressure difference between the suction port 26 and the chamber 36 communicating with the suction chamber 24 through the small hole 33 is great also. Thus, a difference between a primary pressure and a secondary pressure on primary and secondary sides of the valve body 34 is great. As a consequence, the valve body 34 is separated from the valve seat 35 and moves towards the bottom wall 31 c with the return spring 37 compressed to a large extent. In this event, an opening area of the main channel 32 is increased. As a result, the refrigerant gas of a high flow rate flows from the suction port 26 through the main channel 32 into the suction chamber 24 .
At a low flow rate, the pressure difference between the suction port 26 and the suction chamber 24 is small. Therefore, the pressure difference between the suction port 26 and the chamber 36 communicating with the suction chamber 24 through the small hole 33 is small also. Thus, the difference between the primary pressure and the secondary pressure on the primary and the secondary sides of the valve body 34 is small. As a consequence, the valve body 34 compresses the return spring 37 to a less extent so that the valve body 34 approaches the valve seat 35 . In this event, the opening area of the main channel 32 is reduced. At the low flow rate, pressure pulsation of the refrigerant gas caused by self-induced vibration of the suction valve 22 is attenuated during passage through the main channel 32 reduced in opening area. This suppresses a vibration noise of an evaporator resulting from the pressure pulsation propagating from the suction port 26 through the external refrigerating circuit to the evaporator.
At a very low flow rate, the pressure difference between the suction port 26 and the suction chamber 24 is very small. Thus, the primary pressure and the secondary pressure on the primary and the secondary sides of the valve body 34 are substantially balanced with each other, i.e., substantially equal to each other. Under a weak urging force of the return spring 37 restored into a substantially unloaded condition, the valve body 34 is brought into contact with the valve seat 35 so that the main channel 32 is closed. The refrigerant gas introduced from the suction port 26 passes through the bypass holes 39 and flows through the suction port 26 into the suction chamber 24 and then into the cylinder bore 15 . Each of the bypass holes 39 is referred to as a bypass channel.
At the very low flow rate, the substantial balance between the primary pressure and the secondary pressure on the primary and the secondary sides of the valve body 34 is lost in a suction stroke as a result of pressure loss while the refrigerant gas introduced from the suction port 26 passes through the bypass holes 39 . On the other hand, in a compression stroke, the refrigerant gas does not flow through the bypass holes 39 so that the substantial balance between the primary pressure and the secondary pressure on the primary and the secondary sides of the valve body 34 is recovered. Therefore, the valve body 34 is applied with the external force varying in a short cycle. However, since the valve body 34 forms the piston of the fluid damper 38 , the valve body 34 does not follow the short-cycle variation in external force and does not repeatedly perform fine movement. Therefore, neither the pressure pulsation of the refrigerant gas nor the noise is induced.
In the foregoing, one embodiment of this invention has been described. However, this invention is not restricted to the above-mentioned embodiment.
As illustrated in FIGS. 4A and 4B, the flange 31 d of the opening control valve 30 may be provided with a plurality of bypass holes 42 . Alternatively, as illustrated in FIGS. 5A and 5B, the surrounding wall of the suction port 26 may be provided with a plurality of bypass grooves 43 . In this event, each of the bypass grooves 43 serves as the bypass channel.
The opening control valve 30 may be fixed to the cylinder head 19 in various other manners different from that described in conjunction with the above-mentioned embodiment. For example, a number of keys are formed in a peripheral edge of the flange 313 in a radial fashion while a number of key grooves are formed in the surrounding wall of the suction port 26 in a radial fashion. Then, the keys are press-fitted into the key grooves. Alternatively, a number of keys are formed in the surrounding wall of the suction port 26 in a radial fashion while a number of key grooves are formed in the peripheral edge of the flange 313 in a radial fashion. Then, the keys are press-fitted into the key grooves. Further alternatively, as illustrated in FIG. 6A, a step portion is formed on the surrounding wall of the suction port 26 and is provided with a protrusion 44 . The protrusion 44 is press-fitted into a hole 45 formed in the flange 313 . As illustrated in FIG. 6B, the bottom wall 312 is provided with a protrusion 46 to be press-fitted or inserted into a recess 47 formed in the surrounding wall of the suction chamber 24 . As illustrated in FIG. 6C, the bottom wall 31 c is provided with a hole 48 to which a protrusion 49 formed on the surrounding wall of the suction chamber 24 is press-fitted or inserted. As illustrated in FIG. 6D, the flange 313 may be fixed to the surrounding wall of the suction port 26 by screw engagement. In either way, the opening control valve 30 can readily be fixed to the cylinder head 19 .
In the variable displacement compressor, the valve body of the opening control valve does not repeatedly perform fine movement so that the pressure pulsation of the refrigerant gas is not caused to occur. As a consequence, the noise resulting from the pressure pulsation of the refrigerant gas is not produced. | 4y
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefits of and priority to U.S. Provisional Patent Application Ser. No. 60/722,073 entitled “MODIFIED ACME SCREW/NUT SET” which was filed on Sep. 29, 2005, the entire contents of which are hereby incorporated by reference herein.
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] The present disclosure relates to an Acme screw/nut set, and more particularly to an Acme screw/nut set having a modified thread design.
[0004] 2. Background of the Art
[0005] Drive mechanisms for different applications utilizing a lead screw as a driver usually use a standard Acme screw class G or C. A standard centralizing Acme screw/nut set class C has defined tolerances per ANSI B1.8 specification. Those tolerances provide very low clearances between the thread of the nut and the thread of the screw. For example: a 1½- 5 ACME thread class 2C has the following clearances:
[0006] for a major diameter a radial clearance is R min =0.0012″ to 0.0098″ and
[0007] for a pitch diameter an axial clearance is A min =0.0025″ to 0.14″.
[0008] The clearances are extremely low for the lower tolerance range. Therefore, a problem arises when using dissimilar materials with significantly different thermal expansion coefficients (e.g. steel and nylon). That is, the clearances will close quickly when the temperature of the joint increases due to the heat generated by friction between the components in the drive mechanism. The problem is especially prevalent in a design where the nut is confined in a rigid housing, thereby restricting radial expansion and allowing expansion of the nut material mainly in the inward direction. The lack of clearance between the screw and the nut may initially result in a grinding noise and finally in seizing the motion of the joint.
[0009] The following example is illustrative:
[0010] Assume the following materials and dimensions:
Acme screw D= 1½ major diameter and P= 0.200″ made of carbon steel Acme Nut (modified) of same basic thread with O.D.=1.125″ and 2.5″ long made of nylon 6 with a thread engagement L=2.312″ Nut housing made of aluminum with bore B=2.125″ dia. Carbon steel has a coefficient of thermal expansion
CTE s 8.1*10 E−6 in./in. ° F.
Nylon 6 has a coefficient of thermal expansion
CTE n 0.45*10 E−4 in./in. ° F.
Aluminum housing has a coefficient of thermal expansion
CTE h 13.1*10 E−6 in./in. ° F.
[0017] For the screw/nut pair in this example, it would take a temperature increase (ΔT) of 17° F. from the ambient temperature to close the gap of 0.0012″.
[0018] The relevant calculations for determining the effect of a temperature rise on the gap are as follows:
[0019] The nut material would expand radially inward (Rn) (assuming zero outward expansion allowed by the housing)
Rn=Δt*CTE n *D =17*0.45*10 *E −4*1.5=0.0011475″
[0020] The screw material would expand radially outward (Rs)
Rs=ΔT*CTE s *D =17*8.1*10* E −6*1.5=0.00020655″
[0021] The housing material would expand radially outward (Rh) (allowing the nut to expand outward the same amount). However, the expansion of the housing material is to a lesser degree than the expansion of the screw and the nut, due at least in part to the fact that the temperature of the housing material rises only approximately 30% of the temperature rise of the two other components (based on taken measurements).
Rh= 0.3 *ΔT*CTEh (aluminum)* B =0.3*17*13.1*10 *E− 6*2.125=0.00014187″
[0022] The total expansion (R) of the joint in a radial direction may be calculated as follows:
R=Rn+Rs−Rh =0.0011475+0.00020655=0.00014197=0.001212″
[0023] The temperature of the Acme screw/nut surface may be subjected to temperatures up to 200° F. based on the material specification of nylon 6, for example, for a high load condition. Accordingly, undue friction and potential binding of machine parts may occur. The screw/nut design of the present disclosure may ameliorate such occurrences.
SUMMARY
[0024] The present disclosure relates to a nut and screw set which reduce the amount of hindered motion therebetween caused by thermal expansion of the screw and the nut. The nut and screw set includes a screw (e.g., made of steel) and a nut (e.g., made of plastic). The screw (e.g., a 1½- 5 Acme screw) includes a plurality of screw threads and the nut includes a plurality of nut threads, such that the screw and the nut and threadably engagable with each other. The nut threads are sized to reduce hindered motion between the screw and the nut as a result of thermal expansion of the screw and the nut. The temperature change which causes the thermal expansion is disclosed to be between about 100° F. to about 160° F.
[0025] In a disclosed embodiment, the screw has a first coefficient of thermal expansion and the nut has a second coefficient of thermal expansion. The two coefficients of thermal expansion are not equal in an embodiment.
[0026] In an embodiment, the nut and screw set also includes a housing which is dimensioned to at least partially cover the nut. Additionally, a disclosed nut includes a nut groove which is defined between two adjacent nut threads. The width of the nut groove is disclosed to be in the range of about 0.079 inches to about 0.082 inches.
[0027] The present disclosure also relates to a method of modifying a nut in a nut and screw set to reduce hindered motion between the screw and the nut as a result of thermal expansion of the screw and the nut. A disclosed method includes providing a nut and a screw, calculating the amount of thermal expansion for the nut and the screw for a predetermined change in temperature, and increasing the width of the nut groove if the calculated amount of thermal expansion is greater than the existing width of the nut groove.
[0028] The present disclosure also relates to a method of determining the width of grooves of a nut in a nut and screw set to optimize operation therebetween and while considering thermal expansion of the nut and the screw.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosure and, together with a general description of the disclosure given above, and the detailed description of the embodiments given below, serve to explain the principles of the disclosure.
[0030] FIG. 1 is a side view in partial cross-section of a screw/nut set in accordance with an embodiment of the present disclosure;
[0031] FIG. 2 is an enlarged side view in cross-section of a modified Acme thread configuration on major diameter in accordance with an embodiment the present disclosure;
[0032] FIG. 3 is a side view in cross-section of a modified Acme thread configuration on a major diameter in accordance with an embodiment of the present disclosure with the details showing the relation between radial and axial clearances in the thread; and
[0033] FIG. 4 is an enlarged side view in cross-section of a modified Acme thread configuration on a major diameter in accordance with an embodiment of the present disclosure.
DETAILED DESCRIPTION
[0034] Various embodiments of the presently disclosed Acme screw/nut set are described in detail with reference to the figures, in which like reference numerals identify corresponding elements throughout the several views. The abbreviation “e.g.” in the figures stands for “for example” indicating that the dimensions and angles shown in the figures are exemplary dimensions and angles.
[0035] In the context of drive mechanisms and other mechanical devices, a high load application commonly creates a high amount of friction and, consequently, a high temperature condition. The modification of an Acme nut in accordance with the present disclosure minimizes noise generation, excessive friction and motion seizure in a high load condition for Acme screws. A method of calculating the radial clearance required on the major thread diameter, in an effort to minimize loss of performance and motion is also disclosed.
[0036] Referring now to FIG. 1 , a screw/nut set 10 in accordance with the present disclosure is shown. Screw/nut set 10 includes an Acme screw 15 and a nut 20 . Nut 20 is illustrated mounted within nut housing 25 . Screw 15 may be an Acme Screw class C, and Acme nut 20 shown in FIG. 1 may include a modified internal thread in accordance with the present disclosure. Screw/nut set 10 illustrated in FIG. 1 is representative of a 1½- 5 screw having a diameter (x) equal to 1.50 inches. The diameter (y) of nut 20 is equal to 2.125 inches. These dimensions are provided as examples only and not provided to, nor intended to, limit the scope of this disclosure. It is contemplated that this disclosure is not directed to any one particular size screw and/or nut. Rather, the present disclosure may be applied to a plurality of screws and nuts having a plurality of different dimensions.
[0037] The following formula is applied to determine the minimum required clearance as a function of a predetermined temperature rise (ΔT) above the ambient temperature. The minimum required clearance is defined as the clearance necessary to essentially prevent seizure of the motion of the mechanical components at the elevated temperatures encountered during normal working conditions.
[0038] Since nut 20 is restrained on its outer periphery by housing 25 , as the temperature of nut 20 increases, nut 20 will expand radially inward. An assumption is being made that there will be no outward expansion of nut 20 due to the restraining force exerted by nut housing 25 . The amount of thermal expansion of nut 20 is calculated by the following equation where Rn is representative of the amount of thermal expansion. CTEn represents the coefficient of thermal expansion of the nut material, ΔT represents the raise in temperature from the ambient temperature, and D represents the major diameter of nut 20 .
Rn=ΔT*CTEn*D
[0039] Similarly, screw 15 is a solid mass and, therefore, will expand radially outward as its temperature increases. The amount of thermal expansion of screw 15 is calculated by the following equation where Rs is representative of the amount of thermal expansion of screw 15 . CTEs represents the coefficient of thermal expansion of the screw material, ΔT represents the raise in temperature from the ambient temperature, and D represents the major diameter of Acme screw 15 .
Rs=ΔT*CTEs*D
[0040] The material of nut housing 25 will also expand radially outward as its temperature increases. The amount of thermal expansion of the housing 25 is calculated by the following equation where Rh is representative of the amount of thermal expansion of nut housing 25 . Nut 20 is able to expand radially outward in an amount which is proportional to the amount of expansion of nut housing 25 . CTEh represents the coefficient of thermal expansion of the housing material, ΔT represents the raise in temperature from the ambient temperature, and the variable B represents the diameter of the bore of nut housing 25 .
Rh= 0.3 *ΔT*CTEh*B
[0041] The required clearance on the major diameter due to the thermal expansion may be calculated by the following equation:
R=Rn+Rs−Rh=ΔT*CTEn*D+=ΔT*CTEs*D −0.3 *ΔT*CTEh*B
R=ΔT{D ( CTEn+CTEs )−0.3 *CTEh*B}
[0042] Utilizing the values in the example described above, the following results are obtained:
R =17{1.5(0.45*10 *E −4+8.1*10 *E− 6)−0.3*13.1*10 *E− 6*2.125}=0.001212″
[0043] Thus, the total radial clearance required on the major diameter of the thread including a factor of safety (g) is calculated as follows:
Rt=Rn+Rs−Rh+g=ΔT*CTEn*D+=ΔT*CTEs*D −3*Δ T*CTEh*B+g
Rt=ΔT{D ( CTEn+CTEs )−0.3 *CTEh*B}+g
The factor of safety contemplates, for example, extra radial clearance on the major diameter of the thread for grease retention and a misalignment accommodation.
[0044] Applying the values of the example given above with a temperature rising from 70° F. to 200° F. (ΔT=130° F.) and factor of safety of g=0.004″ the total clearance will be as follows:
Rt= 130{1.5(0.45*10 *E −4+8.1*10 *E −6)−0.3*13.1*10 *E −6*2.125+0.004=0.0133″
The clearance value may be rounded up to 0.014″+0.003″.
[0045] Since there will be an axial backlash increase due to the radial clearance increase, the width of the internal thread of nut 20 is adjusted to achieve a minimum axial clearance, in the design of the modified centralized AcmesScrew/nut set 10 in accordance with the present disclosure.
[0046] Referring now to FIG. 2 , a modified Acme thread configuration on major diameter in accordance with the present disclosure is illustrated. Width X 1 of screw thread 30 on major diameter and width X 2 of thread groove 35 of nut 20 also on the major diameter are shown as per ANSI B1.8 standard without any modification. Thread 30 of screw 15 remains unchanged. Screw 15 is shown crowded to the one side of the thread 35 of nut 20 .
[0047] The axial clearance expanded from Amin.=0.0025″ to 0.0058″ based on the relationship between radial and axial clearances shown in FIG. 3 . Referring to FIG. 3 , an Acme thread modified on major diameter in accordance with the above-described example is illustrated. The detail views in FIG. 3 illustrate the relationship between radial and axial clearances in the thread.
[0048] The increase in axial clearance (backlash) is governed by the following equations:
Δ A/ΔR=tg 14.5°where Δ R=Rt−Rmin . (from previous calculations)
Δ A =( Rt=Rmin )* tg 14.5°
[0049] Therefore, the total backlash ΔAr due to an increase in radial clearance and an initial minimum axial backlash is a sum of ΔA and Amin.
Δ Ar−ΔA+Amin .=( Rt−Rmin .)* tg 14.5 °+Admin.
[0050] In the example described herein:
Δ Ar =.(0.14−0.0012)* tg 14.5°+0025=0.0128*0.2586+0025=0.0058″
[0051] In accordance with an embodiment of the present disclosure, groove 35 of nut 20 is widened to accommodate an axial thermal expansion difference between the material of screw 15 and the material of nut 20 . The expansion of nut 20 in the axial direction is calculated in accordance with the following equation:
Δ An=ΔT*CTEn*L L—length of the nut
[0052] Next, the expansion of screw 15 in the axial direction for the length of nut 20 is calculated in accordance with the following equation:
ΔAs=ΔT*CTEs*L
[0053] Thus, the total required axial backlash due to the thermal expansion may be calculated in accordance with the following equation:
At=ΔAn−ΔAs=ΔT*CTEn*L−ΔT*CTEs*L=ΔT*L *( CTEn−CTEs ) where ΔAn>ΔAs
[0054] The value derived from this calculation represents the minimum backlash at the pitch diameter. Groove 35 of nut 20 may be physically enlarged to provide this backlash. As determined above, the backlash is equal to ΔAr and is due to the increase of clearance in the radial direction. Consequently, groove 35 of nut 20 may be widened based on the difference between total thermal expansion requirement At and an existing backlash ΔAr as shown in the following equation to determine Afin:
Afin=At−ΔAr=ΔT*L *( CTEn−CTEs )−( Rt−Rmin )* tg 14.5 °−Amin
Afin=ΔT*L *( CTEn−CTEs )−[(Δ T{D ( CTEn+CTEs )−0.3 *CTEh*B}+g−Rmin]*tg 14.5 °−Amin
[0055] After applying the values from the example described above, the following value Afin can be derived from the above formula:
Afin =130*2.312*(0.45*10 *E −4−8.1*10 *E 6)−[130{1.5(0.45*10 *E −4+8.1*10 *E −6)−0.3*13.1*10 *E −6*2.125}+0.004−0.0012 ]*tg 14.5°−0.0025.
Afin=0.00546″
[0056] This Afin value is the dimension value which has to be added to the existing width of groove 35 of nut 20 . In the example described herein, the minimum width for the top of groove 35 is 0.0738″ based on ANSI B 1.8 (see FIG. 2 ). After adding 0.00546 (Afin) to that dimension the final groove width Wg is:
Wg= 0 . 079 ″
[0057] The additional axial clearance may be added to the Wg dimension if necessary. In this case, due to the flexibility of the plastic nut material with an unobstructed expansion flow in the axial direction, no additional clearance was implemented other than the positive tolerance.
[0058] As illustrated in FIG. 4 , nut 20 of the drawing calls for 0.079″+0.003/−0.000. FIG. 4 shows the Acme nut drawing in cross-section detail with the circled dimension 0.079+0.003/−0.000.
[0059] While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the present disclosure, but merely as illustrations of various embodiments thereof. For example, although the above embodiments are described with reference to one particular configuration of a screw/nut set, the present disclosure may find application in conjunction with screw/nut sets having many different configurations and dimensions. Accordingly, it is contemplated that the disclosure is not limited to such an application and may be applied to various screw/nut sets. Those skilled in the art will envision many other possible variations that are within the scope and spirit of the present disclosure. | 4y
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FIELD OF THE INVENTION
The present invention relates to a lock assembly. In particular, the invention relates to an apparatus for retaining a retractor mechanism used to extend and retract a latch of the lock assembly.
BACKGROUND OF THE INVENTION
Lock assemblies generally include a retractor mechanism attached to a latch or bolt and supported by a chassis mounted in a door. The retractor mechanism extends and retracts the latch to secure access through the door.
SUMMARY OF THE INVENTION
Typically, the retractor mechanism must be assembled and installed while building-up a chassis to support the lock assembly in the door. Likewise, removal of the retractor mechanism requires the disassembly of the chassis as well. The present invention provides an innovative design of a retainer apparatus for the retractor mechanism. The retainer apparatus of the invention allows the retractor mechanism to be pre-assembled before or after the chassis has been assembled. Manufacturers and installers of lock assemblies will find this innovative design less cumbersome when assembling and/or dissembling a lock assembly.
In one embodiment, the invention provides a retractor retainer apparatus for a retractor mechanism that extends and retracts a latch. One embodiment of the retainer apparatus is a clip that is operable to hold the retractor mechanism and the latch. The clip includes a back component having a first and second end, the back component having at least one post for mounting a spring to bias the retractor mechanism, a first side component having a first end connected to one end of the back component, and a second side component having a first end connected to the other end of the back component, wherein the first and second side components provide a bearing surface to slide the latch retractor mechanism, and a first front component connected to the second end of the first side component, and a second front component connected to the second end of the second side component, the first and second front components angled inward to form a narrowed gap that retains the latch retractor mechanism and allows extension and retraction of the latch to secure access through the door.
In another embodiment, the invention provides a door lock assembly for securing a door, the lock assembly including a retractor mechanism to linearly extend the latch to a locked position and to retract the latch to an unlocked position, a chassis to support the lock assembly in the door, and a retainer apparatus to hold the retractor mechanism, the retainer apparatus having a back component having at least one post for mounting at least one spring to bias the retractor mechanism, a first and a second side component each having one end connected to each end of the back component, said first and second side components providing a bearing surface for moving the retractor mechanism, a first and a second front component connected to the other ends of the first and the second side components, the front components angled inward to form a narrowed gap, wherein the retainer apparatus retains the retractor mechanism in the chassis.
Briefly summarized, the retractor retainer apparatus is a clip having a back component, a pair of side plate components, and a pair of front plate components that retains a retractor mechanism for extending and retracting a latch. The retainer apparatus allows the retractor mechanism to be pre-assembled, where this sub-assembly is ready for installation or connection to a partially or completely pre-assembled chassis of a lock assembly. One embodiment of the clip is a single formed piece that includes a back component having at least one post for mounting a spring to bias the retractor, side components to provide a bearing surface to slide the retractor for the latch, and front components angled inward to retain the retractor and engage the latch. A plurality of prongs extend from the clip to hold the clip to the chassis of the lock assembly. Manufacturers will find the sub-assembly of the retractor mechanism less cumbersome and time consuming when assembling and/or disassembling the lock assembly.
As is apparent from the above, it is an aspect of the invention to provide a retainer apparatus for a latch retractor mechanism that secures access through a door. Other features and aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a lock assembly with a retractor mechanism and a retractor retainer apparatus.
FIG. 2 is a perspective view of the retainer apparatus.
FIG. 3 is a perspective view of the retractor mechanism and retainer apparatus.
FIG. 4 is a perspective view of the retainer apparatus and retractor mechanism connected to a chassis.
DETAILED DESCRIPTION
Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items.
FIG. 1 illustrates a perspective view of a lock assembly 4 that includes a latch apparatus or retractor assembly 6 . One embodiment of the retractor assembly 6 includes a retractor or retractor mechanism 8 retained in a retainer apparatus 10 .
FIG. 2 illustrates one embodiment of the retainer apparatus 10 for retaining the retractor mechanism 8 . As illustrated in FIG. 2 , the retainer apparatus 10 includes a retainer clip having a back component 15 , a first 20 and a second 25 side component, and a first 30 and a second 35 front component. In one embodiment, the back component 15 , first 20 and second 25 side components, and first 30 and second 35 front components are machined-formed from a single metal plate (e.g., steel plate). In an alternative embodiment, the components of the retainer apparatus 10 can be created separately and inter-connected using any suitable means (e.g., spot-welded, soldered, etc.) known to those in the art.
As shown in FIG. 2 , one embodiment of the back component 15 is a curvilinear-shaped metal plate. The curvilinear shape is designed to conform to the overall shape of the lock assembly 4 . In alternative embodiments, the back component 15 can include other shapes (e.g., bends, flat sides, etc.) suitable for the lock assembly 4 . Another embodiment of the back component 15 includes a pair of posts 40 and 45 . As shown in FIGS. 2 and 3 , the posts 40 and 45 support the retractor mechanism springs 50 and 55 . One embodiment of the posts 40 and 45 are machined stamped or cut out from the back component 15 and angled in a direction inwardly with respect to or from the back component 15 . In another embodiment, the posts 40 and 45 can be separate components attached to the back component 15 using other suitable means (e.g., spot-welded) known to those in the art. In yet another embodiment, the posts 40 and 45 can be stamped or cut out from a portion of the back component 15 and each side component 20 and 25 . The back component 15 also includes a catch spring base 60 . The catch spring base 60 supports a catch spring biased against a catch of the retractor mechanism 8 (discussed later).
The first 20 and second 25 sides form the bearing surfaces for sliding the retractor mechanism 8 in a linear direction between an extended and a retracted position. As shown in FIG. 2 , the first 20 and second 25 side components have one end connected to each end of the back component 15 . One embodiment of side components 20 and 25 are flat plates to support the linear sliding of the retained retractor mechanism 8 . Of course, the shape of the side components 20 and 25 can vary. The first 20 and the second 25 side components are designed to have some elasticity to enable installation of the retractor mechanism 8 .
As shown in FIGS. 2 and 3 , the first 30 and second 35 front components constrain the retractor mechanism 8 against the back component 15 and the bias of the springs 50 and 55 . FIGS. 2 shows one embodiment of the first 30 and the second 35 front components angled inward with respect to the ends of the first 20 and second 25 side components. The inward-angled front components 30 and 35 form a narrowed gap 65 . The width of the gap 65 is designed to constrain the retractor mechanism 8 , yet allow the extension and retraction of a latch or bolt 70 ( FIG. 1 ) of the retractor mechanism 8 . The first 30 and second 35 front components are also designed with some flexibility for installing the retractor mechanism 8 .
FIG. 3 shows a perspective view of the retractor mechanism 8 installed in the retainer apparatus 10 . The retractor mechanism 8 slides along the side components 20 and 25 to extend and retract the bolt 70 ( FIG. 1 ). As shown in FIG. 3 , one embodiment of the retractor-mechanism 8 includes a first 105 and a second carrier 110 , a pair of retractor bars 115 and 120 , and the pair of springs 50 and 55 . The retractor bars 115 and 120 include a pair of lips 125 and 130 that engage the bolt 70 . Drive shafts 135 and 140 ( FIG. 1 ) include cams (not shown) designed to engage the first 105 and second 110 carriers. When rotating drive shaft 135 to retract the bolt 70 , the cams of the drive shaft 135 engages the first carrier 105 . The rotational force of the drive shaft 135 against the carrier 105 causes the retractor mechanism 8 to slide along the side components 20 and 25 against the bias of the springs 50 and 55 . Under the force of the drive shafts 135 and 140 , the retractor mechanism 8 retracts the bolt 70 . Upon release of the rotational force on the drive shaft 135 and 140 , the springs 50 and 55 bias the retractor mechanism 8 forward toward its original position. Thereby, the retractor mechanism 8 slides to extend the bolt 70 . The drive shaft 140 engages the carrier 110 in a similar manner as the drive shaft 135 .
As shown in FIG. 3 , another embodiment of the retractor mechanism 8 further includes a catch 141 . The catch 141 engages a spring 145 compressed against the catch spring base 60 of the back component 15 , thereby biasing the catch 141 toward an extended position. The catch 141 is operable in holding a plunger bar (not shown) in a locked position.
FIG. 4 illustrates a perspective view of a chassis 200 in support of the retractor mechanism 8 and retainer apparatus 10 . In one embodiment, the chassis 200 includes a first 205 and a second 210 side support for the retainer apparatus 10 . As shown in FIGS. 2 and 4 , the retainer apparatus 10 includes a plurality of prongs 240 for receiving the first 205 and second 210 side supports of the chassis 200 . The prongs 240 can be one or more extensions at each end of a component and is not limiting on the invention. In one embodiment, the back component 15 includes two pairs of back prongs 240 b and 240 d that extend past the first 20 and second 25 side components ( FIG. 3 ). Each pair of back prongs 240 b and 240 d extends parallel with the ends of the back component 15 . In addition, one embodiment of the front components 30 and 35 include front prongs 240 a ( FIG. 1) and 240 c that extend outward in a similar fashion past the first 20 and second 25 side plates. Similar to prongs 240 b and 240 d in relation to the back 15 , the front prongs 240 a and 240 c extend parallel with each end of the first 30 and the second 35 front plates. The back prongs 240 b and 240 d and the front prongs 240 a and 240 d are located at opposite ends of the first 20 and second 25 side components and angled inward to receive the first 205 and second 210 side supports of the chassis 200 . One embodiment of the prongs 240 a–d are machine stamped or cutout from the first 20 and second 25 side components. Of course, the prongs 240 a–d can be separate components attached using other suitable means (e.g., spot-welded, soldered, etc.) known to those in the art.
As shown in FIG. 4 , the first 205 and second 210 side supports of the chassis 200 include reliefs 250 to receive the prongs 240 a–d of the retainer apparatus 10 . One embodiment of a relief 250 is a beveled edge at an angle compatible with the angle of the prongs 240 a–d. Of course, other shapes (e.g., channels) for a relief 250 in the side supports 205 and 210 of the chassis 200 can be used.
As shown in FIGS. 2–4 , the retainer apparatus 10 allows the retractor mechanism 8 to be assembled individually from the build-up of the chassis 200 that supports the lock assembly 4 . FIG. 2 illustrates one embodiment of the retainer apparatus 10 that is formed from machine pressing a metal plate. An operator pre-assembles the retractor assembly 6 by flexing the side components 20 and 25 , then inserting the retractor mechanism 8 inside the retainer apparatus 10 . Upon unflexing the side components 20 and 25 , the retractor mechanism is constrained.
Once the retractor assembly 6 is pre-assembled, the retractor assembly 6 can be inserted or connected to the chassis 200 as shown in FIGS. 1 and 4 . In one embodiment, the chassis 200 is pre-assembled individually from the retractor assembly 6 . Upon individual assembly of the retractor assembly 6 and the chassis 200 , an operator can insert or slide the assembled retractor apparatus 6 , as shown by arrow 255 in FIG. 4 , into an aperture 258 formed by the assembled chassis 200 . As described above, the prongs 240 a–d secure the retractor assembly 6 to the chassis 200 . To disassemble the lock assembly 4 , the retractor assembly 6 can be removed from the chassis 200 without disassembling the retractor mechanism 8 and/or chassis 200 similar to the method for assembly described above. In one embodiment, an operator can slidingly remove the retractor assembly 6 from the reliefs 250 of the chassis 200 without disassembling the chassis 200 . Thereby, the design of the retractor mechanism 8 and retainer apparatus 10 of the invention is more versatile and less cumbersome to assemble and/or disassemble. In another embodiment, the retractor assembly 6 can be slid along the reliefs 250 when assembling the chassis 200 of the lock assembly 4 .
FIG. 1 illustrates an exemplary embodiment of a lock assembly 4 with the retractor assembly 6 interconnected through an aperture 258 with an assembled chassis 200 . The chassis 200 includes a first 260 and a second 265 hub having openings for receiving the drive shafts 135 and 140 . The exemplary first hub 260 and second 265 hubs are mounted using screws 270 . Of course, other suitable connection means (e.g., spot-weld, cast, etc.) known in the art can be used. One embodiment of the chassis 200 is comprised of cast metal. Of course, the chassis 200 can be comprised of cast metal and/or one or more other suitable materials (e.g., forged metal, plastic) known in the art of lock assemblies.
Thus, the invention provides, among other things, a retractor assembly having a retractor mechanism retained in a retainer apparatus for connection to a chassis of a lock assembly. Various features and advantages of the invention are set forth in the following claims. | 4y
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The present application claims priority under 35 U.S.C. § 119 to Patent Application Ser. No. 0402666-2 filed on Nov. 3, 2004 and Patent Application Ser. No. 0401734-9 filed on Jul. 2, 2004 in Sweden, respectively.
TECHNICAL BACKGROUND OF THE INVENTION
The present invention relates to an air distribution assembly for a rotary cutting apparatus having a shaft and a mantle, the mantle having at least one cutting member.
The invention also relates to a rotary cutting apparatus provided with such an air distribution assembly.
Air distribution in a rotary cutting apparatus is previously known and is performed by radial bores formed in the circumferential surface of a solid rotary cutter. Axial bores connect the radial bores with sources of vacuum and/or atmospheric pressure or over-pressure. Drilling of such axial and radial bores is time consuming and expensive, in particular since they have to be made with high accuracy.
U.S. Pat. No. 4,770,078 discloses in a discussion of the prior art ( FIGS. 1-3 ) a one piece rotary cutter, which has to be removed from the frame when maintenance is needed. In order to allow the machine to be used during maintenance, a further rotary cutter including its static shaft must always be accessible.
In order to overcome that problem, U.S. Pat. No. 4,770,078 suggests to divide the rotary cutter into a rotatable shaft and a mantle. The mantle is connected to the rotatable shaft by means of pneumatic pressure. A drawback with this kind of rotary cutter is that it is difficult to index the rotary cutter relative to the anvil. Another drawback is the lack of support of the rotary cutter on the side opposite to the driven side.
SUMMARY OF THE INVENTION
An object of the invention is to provide the known rotary cutter with a simplified connection to sources of vacuum and/or atmospheric pressure or over-pressure.
This has been achieved by the air distribution assembly of the initially defined kind, which comprises a first air distribution part adapted to rotate together with said mantle and a second air distribution part adapted to be connected to the center shaft.
Preferably, said first air distribution part is provided with openings adapted to correspond to through holes of said mantle and wherein said second air distribution part is provided with openings adapted to at least intermittently correspond to the openings of said first air distribution part. Hereby is achieved a simplified distribution of air to the exterior of the surface of the rotary cutter.
More particularly, said first air distribution part is provided with at least one first opening adapted to correspond to through holes of the mantle intended to influence a region of the mantle relating to the residues of a cut sheet or the sheet to be cut, and at least one second opening adapted to correspond to through holes of the mantle intended to influence a region of the mantle regarding the cut article or the article to be cut.
Alternatively, only the region comprising the first or the second opening is influenced.
In addition, said second air distribution part is provided with at least one third opening adapted to at least intermittently correspond to said first opening, said third opening being associated with a source of vacuum.
Suitably, said second air distribution part is provided with at least one fourth opening adapted to at least intermittently correspond to said second opening, said fourth opening being associated with a source of vacuum.
Alternatively, said second air distribution part is provided with at least one third opening adapted to at least intermittently correspond to said first opening and/or to said second opening, said third opening being associated with a source of vacuum;
Suitably the radial peripheral surface of the second air distribution part is provided with a groove.
Hereby are achieved different possibilities of controlling the air flow from different through-hole on the surface of the rotary cutter.
Preferably, said second air distribution part is provided with at least one fifth opening for influencing a region of the mantle regarding the region of the mantle regarding the cut article and/or the residue of the cut sheet, said fifth opening being associated with atmospheric pressure or a source of over-pressure.
Suitably, the radial peripheral surface of the second air distribution part is provided with a groove for performing the influence to the region of the mantle regarding the cut article and the residue of the cut sheet.
Hereby are achieved different possibilities of controlling the air flow to different through-hole on the surface of the rotary cutter.
Advantageously, said first air distribution part is adapted to be arranged radially peripheral to that of said second air distribution part.
In particular, said first air distribution part is substantially circular cylindrical and said second air distribution part is substantially circular cylindrical, and wherein said first and second air distribution parts are coaxially arranged in a rotatable interrelationship.
Hereby, a suitable shape of the air distributor parts is achieved.
Preferably, at least one of said shafts is hollow and is associated with a source of vacuum, said second air distribution part being associated with said hollow shaft.
Hereby is achieved a simple and efficient air distribution to the exterior of the rotary cutter.
This has been achieved by a rotary cutter and a rotary cutting apparatus of the initially defined kind, wherein the shaft is adapted to be rigidly mounted in a frame part, and wherein the mantle is rotatably arranged relative to the shaft. Hereby, indexing of the mantle relative to the shaft is made easier, since the mantle can be rotated relative to the static shaft. Furthermore, it is only necessary to perform maintenance of the mantle, i.e. the shaft can be used together with another mantle such that the production can be continued while maintenance is performed on the worn mantle.
Preferably, the mantle is adapted to be connected to a power source for creating a rotational movement of the mantle.
Preferably bearings are provided between the mantle and the shaft. Hereby, a controlled positional and rotational relationship between the static shaft and the mantle is achieved.
Suitably, a power transmission means is provided for transmitting the rotational movement to said mantle.
Advantageously, the mantle has an axial extension and opposite axial ends, wherein said mantle is adapted to be supported by the shaft and connected to the power source in the region of one of the ends of said mantle, and wherein said mantle is adapted to be supported by the shaft in the region of the opposite end.
Alternatively, said shaft is divided into a first and a second shaft member, the mantle having an axial extension and opposite axial ends, wherein said mantle is adapted to be supported by the first shaft member and connected to the power source in the region of one of the ends of said mantle, and wherein said mantle is adapted to be supported by the second shaft member in the region of the opposite end.
Advantageously, the frame part of the rotary cutting apparatus further comprises a fastening means for said shaft and a power transmission connection means for said mantle.
DRAWING SUMMARY
In the following, the invention will be described in greater detail by reference to the accompanying drawings, in which
FIG. 1 illustrates a rotary cutting apparatus comprising an anvil and a cross-section of a rotary cutter according to a first embodiment of the invention;
FIG. 2 is a cross-section of a second embodiment of the rotary cutter;
FIG. 3 is a cross-section of a third embodiment of the rotary cutter;
FIGS. 4A and 4B is an exploded view and an axial cross-section of the first embodiment, provided with an air distribution assembly;
FIGS. 5A and 5B are cross-sections in part of the air distribution assembly shown in FIG. 4B provided with first and a second air distribution parts;
FIG. 5C is a perspective view of the second air distribution part;
FIGS. 6A and 6B are cross-sections in part of alternative air distribution assemblies; and
FIGS. 7A and 7C illustrate the air distribution parts and the mantle in different angular positions.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a rotary cutting apparatus 2 , comprising a rotary cutter 4 and an anvil roll 6 . The rotary cutter 4 comprises a divided static (stationary) shaft 8 , comprising axially spaced shaft members 8 a , 8 b , each member being rigidly connected to a respective frame part 10 a , 10 b by means of screws 12 . A drive axle 14 is associated with a not-shown power source for transmitting a rotational movement to a tool in the form of a mantle 16 via an intermediate transmission member 18 a . The rotational movement is further transmitted to a rotational support 18 b . Cylindrical bearings 19 are provided between the shaft members 8 a , 8 b and the intermediate transmission members 18 a , 18 b , respectively, for centering the mantle 16 relative to the shaft members 8 a , 8 b . The frame parts 10 a , 10 b are secured to the rest of the frame by means of suitable, not-shown fastening means. The mantle 16 is provided with at least one cutting member 17 (See FIG. 4A ) which is endless so as to be able to cut an article from a sheet.
During disassembly, the frame parts 10 a , 10 b are unsecured from the rest of the frame such that the static shaft members 8 a , 8 b including the transmission members 18 a , 18 b can be pulled out from the mantle 16 . The mantle 16 is taken away and maintenance can thus be performed. Another mantle. 16 is mounted in place of the other one, and the rotary cutting device can be utilised without long stoppage.
Of course, it may be enough to take away either of the static shaft members 8 a and 8 b , respectively, rather than both.
FIG. 2 shows a second embodiment of a rotary cutting apparatus 2 ′ and rotary cutter 4 ′. The cross-section is such that the cutting member 17 ′ has been omitted, but is of course present (see FIG. 4 ). The static shaft 8 ′ is in this case a single part and is connected to the frame parts 10 a ′, 10 b ′ on either side of the mantle 16 ′ by screws 12 ′. The rotational movement of the drive axle 14 ′ is transmitted to the mantle 16 ′ via a gear train 20 a ′, 20 b ′, 20 c ′, 20 d ′. It should be noted that the parts 20 b ′, 20 c ′, 20 d ′ could be produced as two pieces or even one single piece. Centering is performed by means of cylindrical bearings 19 ′.
FIG. 3 shows a third embodiment of a rotary cutting apparatus 2 ″ and a rotary cutter 4 ″. Also in this case, the cross-section is such that the cutting member has been omitted. The drive axle 14 ″ transmits rotational movement directly to the mantle 16 ″ via a coupling member 22 ″. The static shaft is divided into two shaft members 8 a ″, 8 b ″ connected to the frame parts 10 a ″, 10 b ″ on either sides of the mantle 16 ″. The mantle 16 ″ is centered relative to the shaft members 8 a ″, 8 b ″ and the driving axle 14 ″ by means of conical bearings 24 ″.
For maintenance purposes, the shaft member 8 b ″ is unsecured from the frame parts 10 a ″, 10 b ″, and then the mantle 16 ″ is released from the shaft member 8 a ″.
The mantle 16 , 16 ′, 16 ″ may be made of a multiphase material, such as steel, cemented carbide or cermet (hard phase bonded by a metal).
FIG. 4A shows a rotary cutting apparatus 2 ′″ and a rotary cutter 4 ′″ similar to the first embodiment (see FIG. 1 ), so the same reference numerals designating the same elements as in FIG. 1 will be used in FIG. 4A . A major difference between the embodiments of FIGS. 1 and 4A is that in FIG. 4A the rotary cutter 4 ′″ is provided with an air distribution assembly 30 which comprises a first air distribution part 32 , a second air distribution part 34 , an air connection piece 36 and said shaft member 8 b ′″, now hollow, for interconnecting the second air distribution part 34 and said air connection piece 36 . The air connection piece 36 is connected to a section of an air source 35 , namely to a source of vacuum pressure 35 a (see FIG. 4A ).
The first and second air distribution parts 32 , 34 may be made of a polymer, a metal, a hard metal or ceramics. It is however not necessary that the parts 32 and 34 be made of the same material.
As already stated above, cylindrical bearings 19 are provided between the shaft members 8 a , 8 b ′″ and the intermediate transmission members 18 a , 18 b , respectively, for centering the mantle 16 relative to the shaft members 8 a , 8 b′″.
The mantle 16 is connected to the first air distribution part 32 by press-fit, fastening means or gluing, whereas the second air distribution part 34 is connected to the connection piece 36 via shaft member 8 b ′″, preferably by a fastening means. Thus, during operation the first air distribution piece 32 rotates together with the mantle 16 , whereas the second air distribution piece 34 is static.
The mantle 16 is provided with first through-holes 40 outside the cutting member 17 and second through-holes 42 inside the cutting member 17 . The reason for this will be explained further below.
FIG. 4B shows the assembled rotary cutter 4 ′″, the mantle 16 and the first and second distribution parts 32 , 34 being coaxially arranged. First and second openings 44 and 46 in the first distribution part are provided for connection to respective through-holes 40 , 42 (see FIG. 4A ) of the mantle 16 . The first and second distribution parts 32 , 34 are hollow and substantially circular cylindrical in shape. During operation, the second distribution part 34 defines a coaxial lumen 47 which connects to the interior of the air connection piece 36 , which in turn is connected to the source of vacuum pressure 35 a.
A connector 49 a is connected to another section of the air source 35 , namely a source of pressure 35 b which is at least at atmospheric pressure 35 b , i.e., atmospheric pressure or an over-pressure. A bore 49 b connects the connector 49 a with a substantially radial bore 49 c of the second air distribution part.
In FIG. 5A , a portion of the first distribution part 32 has been cut away and shows in that relative position of the first and second air distribution parts 32 , 34 , how the first openings 44 connect to a third opening 48 of the second distribution part 34 . The third opening 48 connects in turn to the lumen 47 .
In FIG. 5B , a further portion of the first distribution part 32 has been cut away and shows how the second openings 46 connect to a fourth opening 50 of the second distribution part 34 . The fourth opening 50 connects in turn to the lumen 47 .
Furthermore, in the rotational direction after the fourth opening 50 , a groove 52 is provided in the second distribution part 34 . A longitudinal portion 52 a thereof connects to the second openings 46 , whereas a circumferential portion 52 b continues in the circumferential direction of the second air distribution part 34 .
As can be seen in FIG. 5C , the circumferential portion 52 b of the groove 52 continues with a further longitudinal portion 52 c and continues with a substantially radial bore 49 c , which in turn is connected to the connector 49 a via the bore 49 b (see FIG. 4B ).
The size of the second opening 46 is substantially constant in order to fit the size of the fourth opening 50 . However, in order to fit the form of the article to be cut, i.e. the shape of the knife member 17 , an axial groove 54 is arranged in the surface of first distribution part 32 .
In the same manner, the size of the second opening 44 is substantially constant in order to fit the size of the third openings 48 , and in order to fit the form of the residue of the sheet, i.e. also in this case the shape of the knife member 17 , an axial groove 56 is arranged in the surface of first distribution part 32 .
In FIG. 6A , an alternative embodiment of a second distribution part 34 a is presented, according to which the third and fourth openings 48 , 50 have been interconnected by a longitudinal groove 60 .
In FIG. 6B , the groove 60 is a radial opening, i.e. it projects radially through the part 34 a , whereby the openings 48 , 50 , 60 form a single opening.
FIGS. 7A-7C illustrate how the openings of the air distribution parts 32 , 34 correspond to the through-holes of the mantle 16 in different relative positions.
Consequently, in FIG. 7A broken lines A and B indicate different circumferential positions of the first and second air distribution parts 32 , 34 and the mantle 16 of a pre-determined angular position of the first and second air distribution parts.
The through-holes 40 outside the knife member 17 are connected to the third openings 48 via the first openings 44 along the line A. Similarly, the through-holes 42 along line B and inside the knife member 17 are connected to the fourth opening 50 via the second openings 46 .
Consequently, the through-holes 40 as well as the through-holes 42 will be subjected to a vacuum.
In FIG. 7B is shown that the through-holes 42 along the line C are connected to the groove 52 , whereas the through-holes 40 along the lines D are connected to third openings 48 .
Thus, the through-holes 40 will remain subjected to a vacuum, whereas the through-holes 42 will be subjected to atmospheric pressure or an over-pressure.
However, at line E, also the through-holes 40 along the line E will also be subjected to atmospheric pressure or an over-pressure.
It should be noted that along lines F, the openings 46 are closed, i.e they do not face an opening or a groove in the second air distribution member 34 .
In FIG. 7C is shown that along lines G, the openings 44 as well as the openings 46 are closed.
Thus, during cutting of a sheet, e.g. a web, a cardboard or a metallic foil, and due to vacuum distributed to predetermined through-holes 40 and 42 (see the lines A and B in FIG. 7A ), the whole sheet will stick to the surfaces both outside and inside the knife member 17 , while the knife-member cuts against the anvil roll 6 (see FIG. 1 ).
After cutting the article, the mantle 16 and the first air distribution part 32 has rotated away from the contact with the anvil roll 6 , and to another position of the second air distribution part 34 (see the lines C in FIG. 7B ). The article will come loose from the mantle 16 , due to atmospheric pressure or over-pressure distributed to the same predetermined through-holes 42 , whereas the rest of the sheet will stick to the mantle 16 , due to the vacuum distributed to the same predetermined through-holes 40 . A slight further rotation will cause the openings 46 to close (see the lines F in FIG. 7B ).
Further rotation of the mantle 16 and the first air distribution part 32 relative to the anvil roll 6 and to the second air distribution part 34 will cause also the rest of the sheet to come loose from the mantle 16 , since the same predetermined through-holes 40 will then be subjected to atmospheric pressure or an over-pressure (see line E in FIG. 7B ).
A slight further rotation will cause the openings 46 and then the openings 44 to close (see line G in FIG. 7C ).
With minor modifications of the rotary cutter shown in FIG. 2 , it would also be possible to use the air distribution parts 32 , 34 in that embodiment.
Although the present invention has been described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions not specifically described may be made without departing from the spirit and scope of the invention as defined in the appended claims. | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
Not Applicable.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to housings or containers for automotive oil filters, particularly to such housings designed for permanent or long-term installation on an engine, and having a removable end cap to facilitate replacement of an oil filter element.
2. Description of the Related Art
Most automotive oil filters currently on the market include a paper filter element enclosed within an integral metal container; the container includes a metal base for attaching the assembly to an engine. When such a filter is replaced, disposal and recycling are complicated by the metal parts, which require special equipment for crushing, etc. Disposal, including reclamation of oil contained within the used filter, is much simplified when only the paper filter element requires recycling.
Previous efforts to provide a housing for a replaceable filter include those described by Brown et al. in U.S. Pat. No. 5,738,785; by Ernst et al. in U.S. Pat. No. 5,695,633; and by Brieden et al. in U.S. Pat. No. 5,516,425. Each of the patents referred to discloses a housing having a screw-on cap or cover. What is needed, therefore, is an oil filter housing with a cap that does not require a threaded assembly, and which may be quickly and easily removed and replaced during oil changes.
SUMMARY OF THE INVENTION
The present invention solves the problems outlined in the preceding section by providing a filter housing which replaces a standard oil filter unit. Installed on an engine and left in place, the housing allows only the paper filter element to be replaced. Because filters currently in use have an integral metal housing, the new housing simplifies recycling; i.e., only the paper filter element requires disposal when the engine oil and filter are replaced.
Mounted to an engine in the same way as a standard disposable oil filter, the invention includes a cylindrical housing or container for a paper filter element. The housing's base is threaded onto an engine in the same way as a disposable can-type oil filter, and a removable end cap allows easy replacement of the filter element. Costs are reduced because only the paper element is replaced, while the metal housing remains in place on the engine.
The invention includes a filter housing with a base at one end; the base has a threaded orifice for mounting the housing on an engine. A cap or cover with an attached spring clamp closes the end of the housing through which the filter element is inserted. Arms on the spring clamp extend alongside the housing wall, and engage locking lugs on the perimeter of the wall to hold the cover in place. A band with a ramped surface surrounds the housing adjacent the locking lugs; when the spring arms are pushed against the ramp, the clamp arms are forced outward, disengaging the locking lugs so the cover can be easily removed. An effective seal is provided between cover and housing by a gasket having two sealing surfaces.
In view of the above, it is an object of this invention to provide an oil filter housing which eliminates can-type filters and allows replacement of the filter element only.
A further object is to provide a housing for standard internal oil filter elements now used in the automotive filter industry.
Another object is to provide a filter housing which facilitates replacement of an oil filter and eliminates recycling of can-type filters.
Another object is to provide a filter housing which reduces costs by allowing replacement of the paper filter element only.
Further objects are to achieve the above with a device that is compact, durable, simple, efficient, and reliable, yet inexpensive and easy to install.
The specific nature of the invention, as well as other objects, uses, and advantages thereof, will clearly appear from the following description and from the accompanying drawings, the different views of which are not necessarily scale drawings.
BRIEF DESCRIPTION OF THE DRAWINGS:
FIG. 1 is a front perspective view of the filter housing and cover.
FIG. 2 is a cross section of the housing and cover, on view 1 — 1 of FIG. 3 .
FIG. 3 is a bottom plan view of the housing base.
FIG. 4 is a cross section detail of a spring clamp arm.
FIG. 5 is a cross section detail of a spring clamp arm showing the clamp arm locked in place over a locking lug.
FIG. 6 is a cross section detail of the filter housing wall showing a locking lug and the ramped band.
FIG. 7 is a cross section detail of the filter housing wall showing a locking lug and ramped band, with a spring clamp arm in place over the locking lug.
FIG. 8 is a cross section detail of the housing cover perimeter, showing the gasket groove and gasket spreader.
FIG. 9 is a cross section of a circular gasket having two sealing surfaces.
FIG. 10 is a cross section detail of the housing base perimeter, showing the gasket groove and gasket spreader.
CATALOG OF THE ELEMENTS
To aid in the correlation of the elements of the invention to the exemplary drawings, the following catalog of the elements is provided:
10 oil filter housing
12 base
14 rubber skirt
16 O-ring
18 end cap
20 end cap flange
22 end cap gasket
24 spring clamp
26 spring clamp arm
28 spring clamp shoulder
30 locking lug
32 gasket spreader
34 ramped band
36 finger grip
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings, FIG. 1 illustrates a housing 10 for an oil filter element; FIG. 2 is a cross section of the housing on view 1 — 1 of FIG. 3 . In the preferred embodiment housing 10 is cylindrical, but may be octagonal or some other shape. Housing 10 has internal dimensions to receive and enclose a standard oil filter element; such filter elements are made primarily of paper products, and include a lightweight central stiffener of thin sheet metal. The housing is produced in a variety of sizes to accommodate different sizes of filter elements. Preferably cast of metal such as aluminum, zinc, or magnesium, the housing may also be cast of high-impact, heat-resistant plastic.
Base 12 closes one end of the cylindrical housing. In the center of base 12 is a threaded orifice which mates to a threaded lubricating-oil connector on an engine. Surrounding the engine's threaded connector, through which oil returns to the engine from the filter, are a series of concentric orifices. Around the concentric orifices is a flat surface; when the housing base is screwed onto the engine oil connector, a gasket on the housing base is compressed against the flat surface to form a seal. An oil pump in the engine forces oil through the concentric orifices into housing 10 .
Inside the housing, oil is diverted into the filter element by a resilient rubber skirt 14 , as shown in FIG. 2 . Rubber skirt 14 surrounds the central oil connector and extends outward therefrom; an inner opening in skirt 14 fits tightly about the central threaded orifice, while an outer perimeter of the resilient skirt contacts an inner surface of base 12 . The configuration of skirt 14 prevents oil from passing directly from the concentric orifices back into the oil return passage. A space between the housing wall and the filter element forms a passage through which oil may travel to any part of the paper filter element. Oil is filtered as it flows through the element to a central opening in the element, and from there flows back into the engine through the central threaded connector.
A cylindrical wall of housing 10 is integral with and extends from base 12 . End cap 18 closes and seals an outer end of housing 10 . A flange 20 of end cap 18 extends over and around the outer end of housing 10 . Gasket 22 fits into a groove formed within flange 20 , and is compressed against the end of housing 10 , forming a seal. Gasket 22 includes two sealing surfaces; the surfaces are formed by a notch in gasket 22 , so that one gasket surface bears against the rim of housing 10 , and another gasket surface bears against the inner circumference of housing 10 , adjacent the rim. “Rim,” as used herein, means the extremity or terminal edge of the housing wall. The function of the gasket is further described below.
End cap 18 is held in position against housing 10 by a spring clamp 24 . As shown in FIG. 2, the central portion, or central member, of spring clamp 24 is riveted or otherwise attached to end cap 18 . Two arms 26 of spring clamp 24 extend outward from the central member to the outer perimeter of the end cap, where they curve to fit closely around the perimeter of the end cap. The spring clamp arms 26 then curve back slightly toward the wall of housing 10 and are biased toward the housing wall so that the clamp arms 26 bear against the outer surface of the housing wall. Portions of the spring clamp adjacent the right-angle curve (around the end-cap perimeter) are referred to herein as shoulders 28 . Extensions on the terminal portion of each arm 26 of the spring clamp are recurved to extend outward from the wall of housing 10 to form finger grips 36 used in removing the end cap from the housing.
A series of ramped locking lugs 30 are spaced around the perimeter of housing 10 , as shown in FIG. 1 . As seen in the detailed FIGS. 4, 5 , 6 , and 7 , the locking lugs 30 engage orifices in each arm 26 of the spring clamp to hold the clamp securely in place. Each lug 30 has a matching lug on an opposite side of the housing, so that each lug engages an arm of the spring clamp. An angled surface on the distal portion of each locking lug, in cooperation with an outer wall surface of the housing, forms a V-shaped notch which is engaged by a side of the clamp-arm orifice.
To engage the locking lugs, i.e., to lock the end cap in place, the end cap is placed in position on the housing, and thumb pressure is applied to each shoulder 28 of spring clamp 24 . Sufficient force is applied to the shoulders 28 to bend the spring clamp, moving clamp arms 26 along the housing wall. Each spring clamp arm rides up a lug ramp until the orifice in the clamp arm allows the clamp arm to drop over the lug. Pressure on the clamp shoulders is then released, and as the resilient spring clamp relaxes back toward its original position a side of the orifice in the clamp arm engages the notch formed by the angled surface on the lug, latching the clamp in place. The result is that the end cap 18 is firmly held by tension on the spring clamp against an end of housing 10 , and gasket 22 is compressed between the end cap and the rim of the housing, forming a seal.
A more effective seal is provided by the geometry of gasket 22 . As mentioned above, the gasket has two sealing surfaces. A detail of the gasket's cross section is shown in FIG. 10 . One gasket surface is pressed directly against the rim of housing 10 , while a flange portion of the gasket is pressed against the inner surface of the housing, adjacent the housing end. As seen in FIG. 2, end cap 18 has a generally convex shape, with its central portion raised relative to its perimeter. When the spring clamp is pushed into engagement with the locking lugs, force is exerted by the spring clamp against the center of the end cap, toward the housing. This force tends to flatten the end cap, pushing the perimeter of the end cap outward against the gasket and compressing the flange portion of gasket 22 against the inner surface of the housing wall. A redundant seal is provided by O-ring 16 , disposed in a separate groove in the housing wall as shown in FIG. 2 .
Another feature ensuring a superior seal between end cap and housing is gasket spreader 32 , shown in FIG. 8 . Gasket 22 seats in a groove which is defined by the perimeter flange 20 around the end cap. Gasket spreader 32 is an integral ridge, triangular or semi-circular in cross section, extending around the bottom surface of the end cap groove. An apex of the ridge faces toward the gasket and is pressed into the gasket when end cap 18 is installed. The sloping sides of gasket spreader 32 press against and distend the resilient material of the gasket, compressing it against the groove walls to form a tighter seal. A similar spreader, shown in FIG. 9, is located in the gasket groove in the housing base.
To remove the end cap from the housing, force is applied by a user's thumbs to the shoulders 28 of spring clamp 24 . Sufficient force is applied to the clamp arm shoulders to bend the spring clamp, causing the clamp arms to move along the side of housing wall 10 . As shown in FIG. 2 and FIG. 7, an outward-curving portion of each clamp arm encounters a ramped band 34 extending around the perimeter of the housing wall. Ramped band 34 includes an inclined ramp surface on a side adjacent the series of locking lugs. Riding up the ramp surface causes each end of the spring clamp to be forced away from the housing wall and out of engagement with the locking lugs 30 . Recurved finger grips 36 on each end of the clamp arms are then grasped by a user's finger to hold the clamp arms away from the housing wall, allowing the end cap 18 to be lifted from the housing and removed.
A filter element in housing 10 is centered within the housing and held in position by two retainers, which are stamped from thin sheets of resilient metal. As shown in FIG. 2, one retainer is affixed to the interior of base 12 , and is shaped to engage the central opening in a filter element. The second retainer is attached to end cap 18 , and fits into the other end of the filter's central opening; together the retainers hold the filter element in position inside the housing.
With the filter housing installed, changing an oil filter element is accomplished by first pushing on the spring clamp shoulders to disengage the clamp, allowing the cap to be lifted off the housing. The old filter element is removed for recycling, a new filter inserted in its place, and the end cap is replaced by positioning it on the open end of the housing and pressing on the spring clamp shoulders until the clamp arms engage the locking lugs, securing the end cap in place.
The restrictive description and drawings of the specific examples above do not point out what an infringement of this patent would be, but are to enable one skilled in the art to make and use the invention. Various modifications can be made in the construction, material, arrangement, and operation, and still be within the scope of my invention. The limits of the invention and the bounds of the patent protection are measured by and defined in the following claims. | 4y
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CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority of European Patent Application No. 99307104.2, which was filed on Sep. 7, 1999.
FIELD OF THE INVENTION
The invention relates to multiframe alignment in general and especially to a multiframe alignment for tandem connection trails at Non Intrusive Monitoring (NIM) Trail Termination (TT) sink functions and for TT sink functions in a Synchronous Digital Hierarchy (SDH) and Synchronous Optical Network (SONET) system.
BACKGROUND
The problem addressed with this invention typically arises in Synchronous Digital Hierarchy (SDH) and Synchronous Optical Network (SONET) systems in cases of protection switches within a Tandem Connection Trail. For a better understanding of SDH and SONET systems, reference is made to “Understanding of SONET/SDH”, ISBN 0-9650448-2-3, Andan Publisher, New Jersey.
In the before-mentioned network system a tandem connection is intended to provide an administrative monitoring domain which is operating independent of the end to end path. Rules for the establishment of a tandem connection trail are defined in ETSI EN 300 417-4-1 and ITU-T G.783.
The operation and also the establishment of a tandem connection trail shall influence the rest of the network system as less as possible. Under certain circumstances (i.e. if switching actions are performed within a tandem connection trail), current Tandem Connection Monitoring (TCM) implementations according to the current versions of the standards unnecessarily enlarge signal disturbances.
Accordingly, there is a need to reduce the influence of protection switches within a tandem connection trail in a Synchronous Digital Hierarchy (SDH) or in a Synchronous Optical Network (SONET) System by avoiding enlargements of signal disturbances caused by protection switches.
SUMMARY OF THE INVENTION
Detecting an aligned signal reception or an in multiframe signal transmission state subsequent to an interruption, distortion or switching operation of the signal transmission path on the basis of any received frame alignment signal (FAS) value avoids any undue interruption of the signal transmission caused by the insertion of all one's while searching for the received frame alignment signal (FAS) only at a predetermined position.
If consequently a “FAS found at presumed position” signal is replaced by a “FAS found” signal and generated regardless of the position of a detected multiframe alignment signal and every detected multiframe alignment signal (FAS) is accepted as a valid frame alignment signal (FAS) then the shortest realignment time periods are realized.
BRIEF DESCRIPTION THE DRAWINGS
The invention is explained in more detail below and reference is made to the attached drawings in which it is shown in
FIG. 1 a network comprising a tandem connection trail with a protection mechanism called “sublayer monitored sub-network connection protection” (SNC/S),
FIG. 2 phase relations of two subnetwork connections at the switching point,
FIG. 3 state diagram ‘Multiframe Alignment Process’ as currently implemented,
FIG. 4 dependencies between state transitions,
FIG. 5 state diagram of an adapted multiframe alignment process according to a first inventive embodiment,
FIG. 6 protection switch operation while a frame alignment signal (FAS) overlaps during switching,
FIG. 7 N 1 /N 2 byte bit 7 bit 8 tandem connection multiframe structure,
FIG. 8 structure of frames # 73 - 76 of the bit 7 -bit 8 of a tandem connection multiframe,
FIG. 9 block Diagram ‘out of multiframe (OOM) Filtering’.
DETAILED DESCRIPTION
The invention is explained below in more detail based on preferred embodiments. However, for a better understanding, a standard configuration of a network containing a tandem connection trail with possible switching is depicted in FIG. 1 .
A unidirectional tandem connection trail is established between network element A (NE A) and network element F (NE F), with NE A holding the Tandem Connection source function and NE F holding the Tandem Connection sink function. The sub-network connection between NE A and NE F is protected.
The worker sub-network connection is via NE B-NE C-NE D (signal a), the protection one via NE E (signal b). The protection mechanism is “sublayer monitored sub-network connection protection” (SNC/S) which is based on the result of Tandem Connection Non-Intrusive Monitoring Trail Termination Sink functions for each of the two sub-network connections (SNCs).
In case of a protection switch operation the Tandem Connection Sink function will receive signal b instead of signal a as before.
Data signals which are routed through the network using different routes will experience different run times caused by the transfer delay on the optical fibre or the cable on the one hand and by the processing time in the different network elements on the other. Therefore the two signals will arrive with different phases at a common point (here: input of the protection switch selector at NE F).
It should be noted that 1 km of cable or optical fibre gives about 5 us of transfer delay. In a protected ring architecture, the short route can be between two adjacent nodes, whereas the long route may include all other nodes in the ring. In typical applications the phase difference may be in the range of several SDH/SONET frame lengths. In the following text, only the SDH notation (VC) is used.
FIG. 2 shows the signals a and b with a phase difference T of more than one frame length between the two signals. The signals contain the VC frames ( . . . , x−2, x−1, x, x+1, x+2, . . . ). Switching from a short route to a longer route very likely results in the reception of a number of frames for a 2nd time, whereas switching from a long to a shorter route often causes a loss of a number of frames. This has certain consequences at the tandem connection sink function.
The operation of a tandem connection trail at the tandem connection sink is based on a standardized protocol. This protocol requires to check a frame alignment signal (FAS) contained in the N 1 /N 2 bytes. The frame alignment signal (FAS) is defined as a “1111 1111 1111 1110” bit pattern in frame 1 to 8 of the 76 frames tandem connection multiframe.
The process of checking a multiframe alignment is shown in FIG. 3 . The multiframe alignment is found based on searching for the frame alignment signal (FAS) pattern within the bits 7 to 8 of the byte N 1 /N 2 . In the In Multiframe (IM) state, i.e. the state of a correct signal transmission, the signal is checked continuously at the presumed multiframe start position for the alignment.
However, the frame alignment is deemed to have been lost (entering Out Of Multiframe (OOM) state) when two consecutive frame alignment signals (FAS) are detected in error. Frame alignment is deemed to be recovered, i.e. entering the In Multiframe (IM) state, when one non-errored frame alignment signal (FAS) is found at any position.
A protection switch operation in front of the tandem connection sink function will likely cause a loss or duplication of N 1 /N 2 bytes at the tandem connection sink due to the different signal delays explained above. This causes the alignment process to leave the In Multiframe state, i.e. to enter an Out Of Multiframe OOM state, as the correct length of the tandem connection multiframe structure is disturbed and the frame alignment signal (FAS) will no longer be found at the presumed multiframe start position. The out of multiframe (OOM) state then is interpreted as Loss of Tandem Connection defect (dLTC), which causes consequent actions like an all-ones insertion. As a consequence the egressing signal is overwritten with all-ones until the IM state is entered again.
FIG. 4 shows the dependencies and time sequences of the generated defect caused by the protection switch. The sequence IM (T IM =max. 19 ms/76 ms)→OOM (T OOM =max. 9.5 ms/38 ms)→IM needs about T ALL =max. 28.5 ms for tandem connection signals based on a 125 microsecond VC frame (VC- 4 , VC- 4 -Xc and VC- 3 ) and about T ALL =max. 114 ms for tandem connection signals based on a 500 microseconds VC frame (VC- 2 , VC- 12 and VC- 11 ).
This means that the outgoing signal is disturbed again about T IM (max. 19/76 ms) after a protection switch activity that restored traffic for about T OOM (max. 9.5/38 ms). This disturbance would not exist if there would be no tandem connection trail established.
To avoid extended signal disturbances e.g. as the above described ones, it is necessary according to the invention to change the tandem connection sink processes such that data delay differences caused by protection switches will not create or extend traffic interruptions due to a Loss of Tandem Connection defect (dLTC).
With this approach, the inventive improvement is effective mainly in cases of manual or forced protection switches. In those cases the signal interruption caused by the switching action is very short (less than 10 ms) and the multiframe itself was not disturbed before the switching process. In cases in which the multiframe is lost before the switching action is initiated (e.g. SSF, TC-UNEQ) the advantage of the described solutions is smaller.
Improved Multiframe Alignment Processing
In a first embodiment, the multiframe alignment process is changed such that data delay differences caused by switching actions do no longer result in IM→OOM→IM sequences at the multiframe alignment state machine. To achieve this, the state transition B is changed from “FAS found at presumed position” to simply “FAS found”. Regardless of its position, every detected frame alignment signal (FAS) is accepted as a valid one, i.e. as a “FAS found” signal according to this inventive embodiment and undue delay of the acceptance of a newly aligned or resynchronized signal transmission is avoided.
Further, an “In Multiframe 2 (IM 2 )” state is added. This new “In Multiframe” state is necessary to handle a specific switching situation: If the protection switch action happens at a moment when both the old frame alignment signal (FAS) and the new frame alignment signal are received and the new frame alignment signal (FAS) is received later than the old one, the state machine (see FIG. 3) would also enter an out of multiframe (OOM) state without this IM 2 state. This situation is shown in FIG. 6 . The new processing state diagram is shown in FIG. 5 .
The acceptance of every received frame alignment signal (FAS) independent of the multiframe alignment state and the relative position will avoid state transitions like IM→OOM→IM caused by protection switches within the tandem connection. Such disturbances are compelling in the current implementations.
With the improved multiframe alignment processing the new multiframe position after the switching action is accepted immediately. Therefore the out of multiframe (OOM) state is not entered and no associated subsequent actions as e.g. an all-ones insertion are initiated.
According to the invention the signal disturbance caused by the switching action is kept as short as possible.
However, with this implementation, the possibility of a falsely detected frame alignment signal (FAS) is slightly increased but is still acceptable. The N 1 /N 2 byte protocol as defined in the standards is shown in FIGS. 7 and 8. It requests a ‘0’ in the most significant bit of every Tandem Connection Trail Trace Identifier (TC-TTI) byte. Also the last received Tandem Connection multiframe byte contains 6 bits with the reserved value ‘0’.
To falsely detect a FAS, bit errors must be present in the data signal. There are two conditions under which a false frame alignment signal (FAS) would be detected:
First condition: A CRC- 7 checksum of ‘1111111’ in combination with a bit error in the most significant bit of the first TC-TTI byte and a value of ‘1111110’ contained in the other 7 bits of the first TC-TTI byte occurs.
Second condition: Two bit errors in the most significant bits of two consecutive TC-TTI bytes combined with the TC-TTI values of ‘1111111’ and ‘1111110’ contained in bits 2 to 8 , of these bytes are received.
However, even if a false frame alignment signal (FAS) would be accepted, the mismatch is corrected immediately after the receipt of the next (correct) frame alignment signal (FAS). No additional error would be detected as the trace identifier would be declared false anyway (due to the necessary bit error for the false FAS).
Out of Multiframe (OOM) Filtering
In another preferred embodiment of the invention the insertion of all ones caused by the out of multiframe (OOM) state is suppressed for a certain time. In this solution the Loss of Tandem Connection (dLTC) defect, which causes the all ones insertion, is not directly derived from the-out of multiframe (OOM) state, as it is state of the art. The out of multiframe (OOM) state is detected as currently defined, (see FIG. 3 ), but dLTC is only set if out of multiframe (OOM) is active for a certain time interval.
The interval length is configurable from 0 to 3 tandem connection multiframes. If a period of zero multiframes is chosen, the whole algorithm will behave as the current implementations. Any other value bigger than one will suppress the all ones insertion until the out of multiframe (OOM) state was active for the selected interval length.
In case of protection switches there will be transitions like IM→OOM→IM, but the out of multiframe (OOM) state is shorter than 2 TCM multiframes and the consequent action ‘all-ones insertion’ will therefore be suppressed, because a Loss of Tandem Connection (dLTC) signal won't be set. A block diagram for this solution is shown in FIG. 9 .
An advantage of this process versus the first solution is that the bit error immunity is as high as for the currently used process. A disadvantage is that the detection time for Loss of Tandem Connection (dLTC) is increased.
A further inventive improvement is the suspension of the dTIM defect in case of an OOM state. This will prevent that a dTIM defect is detected due to the protection switch action. Therefore there is no extension of the signal interruption caused by the all-ones insertion which is a consequent action to a detected dTIM defect. | 4y
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CROSS REFERENCE TO RELATED APPLICATION
This application claims benefit of US Provisional Patent Application Ser. No. 61/577,949 filed 20 Dec. 2011, entitled, “Stabilization of Porous Morphologies for high Performance Carbon Molecular Sieves (CMS) Hollow Fiber Membranes and Sorbents Derived from Chemically Modified Polymers,” which application is hereby incorporated fully by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to carbon molecular sieve (CMS) membranes, and more particularly to CMS membranes formed by stabilizing the precursors before they experience pyrolysis to provide improved permeance and selectivity equivalent to or higher than the precursor.
2. Description of the Related Art
Carbon molecular sieve membranes have shown great potential for carbon dioxide (CO 2 ) removal from natural gas streams. In gas separation or membrane applications, a carbon molecular sieve can include a sieve that is comprised of at least ninety percent (90%) atomic weight carbon, with the remainder as various other components. CMS membranes can be formed from the thermal pyrolysis of polymer precursors.
The performance of polymer membranes can be tailored somewhat; however, the separation performance of these polymeric membrane materials has stagnated at a so-called “polymer upper bound trade-off line” related to CO 2 permeability and CO 2 /CH 4 selectivity. This trade-off can result in undesirably high methane loss along with the CO 2 in the permeate stream.
CO 2 permeability is a convenient measure of productivity equal to the flux of CO 2 , which has been normalized by the thickness of the dense selective layer and the CO 2 partial pressure difference acting across this layer. The units of permeability are usually reported in “Barrers”, where 1 Barrer=10 −10 [cc(STP)cm]/[cm 2 ·sec·cmHg]. The membrane selectivity is ideally independent of the thickness of the dense layer, and equals the ratio of the permeability of CO 2 to CH 4 for desirable cases where the ratio of upstream to downstream total pressure is much greater than the permeability ratio of CO 2 to CH 4 .
CMS membranes possess the ability to cross over the upper bound for dense film configurations. It is possible, using conventional CMS dense film membranes, to have CO 2 permeabilities vs methane permeabilities as high as ˜75 for pure gas at 50 psia upstream and at 35° C. Some CMS membranes in hollow fiber configuration can separate CO 2 from 50% CO 2 mixed gas methane stream with selectivities of ˜90 for upstream pressures up to 1168 psia and at 35° C.
Though CMS hollow fiber membranes show encouraging selectivities, they show lower productivity after pyrolysis than would be expected based on the productivity increase in corresponding dense films before and after pyrolysis of the same precursor polymer. The unit of productivity for an asymmetric membrane does not contain a thickness normalizing factor, so the flux is only normalized by dividing by the partial pressure difference acting between the upstream and downstream across the membrane: 1 GPU=10 −6 cc(STP)/[cm 2 ·sec·cmHg].
There are several parameters that can influence the performance of CMS membranes, including, but not limited to: (i) the polymer precursor used; (ii) precursor pre-treatment before pyrolysis; (iii) the pyrolysis process, e.g. final heating temperature or pyrolysis atmosphere; and (iv) post-treatment of CMS membranes after pyrolysis.
Detailed investigations have been performed on CMS dense film membranes using conventional polyimide precursors such as, by way of example and not limitation, Matrimid® 5218 and 6FDA:BPDA-DAM. The chemical structures for both the polyimide precursors are illustrated in FIG. 1 a for thermoplastic polyimide based on a specialty diamine, 5(6)-amino-1-(4′ aminophenyl)-1,3,-trimethylindane (Matrimid®) and 1 b for 2,4,6-Trimethyl-1,3-phenylene diamine (DAM), 3,3,4,4-biphenyl tetracarboxylic dianhydride (BPDA), and 5,5-[2,2,2-trifluoro-1-(trifluoromethyl)ethylidene]bis-1,3-isobenzofurandione (6FDA) commonly referred as 6FDA:BPDA-DAM. Matrimid® 5218 is a soluble thermoplastic polyimide fully imidized during manufacturing, eliminating the need for high temperature processing, and is soluble in a variety of common solvents.
It has been shown that by tuning the pyrolysis process parameters, e.g., final heating temperature, it is possible to modify the resulting CMS membrane performance and achieve greater performance than both these precursors. Other studies have looked at the effect of pyrolysis environments on CMS dense film membranes and related membrane separation performance with different atmospheres containing varied levels of oxygen. The studies introduced the concept of “oxygen doping” on CMS membranes during the pyrolysis, as shown by way of example in US Patent Publication No. 2011/0100211 A1, the contents of which are hereby incorporated by reference.
U.S. Pat. No. 6,565,631 to Koros et al. (Koros), the contents of which are hereby incorporated by reference, extended the CMS dense film to industrially relevant hollow fiber configurations. Koros showed the synthesis of these membranes and evaluated their performance under high feed pressures and impurities. The membranes as taught by Koros are shown to be resistant under extreme conditions without significant degradation in performance. The membranes of Koros, CMS hollow fibers using 6FDA:BPDA-DAM precursors, showed CO 2 permeance of ˜30 Gas Permeation Unit (GPU) with selectivities of 55 for CO 2 /CH 4 upstream pressures up to 1000 psia and at 35° C. from mixed gas methane stream containing 10% CO 2 . Under the same testing conditions for Matrimid® precursor based CMS membranes, the membranes of Koros saw higher selectivities ˜85 for upstream pressures up to 200 psia and at 35° C. but with some decreased permeance of ˜12 GPU.
Low permeances are concerns for the industrial use of CMS hollow fiber membranes. Researchers in this area have tried to address this problem by relating it to the substructure morphology collapse, as shown in FIGS. 2 a and 2 b for a Matrimid®-based precursor. For the purposes of the present invention, we define substructure collapse as shown in the Equation
( thickness ( CMS fiber wall ) thickness ( precursor fiber wall ) ) < 0.8 * ( thickness ( CMS dense film ) thickness ( precursor dense film ) ) ,
to be the situation in which the thickness ratio for the fiber wall after and before pyrolysis is less than 0.8 of the ratio of the thickness for a dense film after and before pyrolysis. Even for robust higher glass transition temperatures (T g ) polymer precursors such as 6FDA:BPDA-DAM, the sub-structure collapse is observed upon pyrolysis but to a lesser extent in comparison to Matrimid® precursors, shown in FIGS. 3 a and 3 b.
The intensive heat-treatment during pyrolysis (above T g ) relaxes the polymer chains, causing their segments to move closer to each other, increasing the actual membrane separation thickness in asymmetric CMS hollow fibers. This increased separation thickness is believed to be the primary cause for the major permeance drop, which is defined as permeability/actual separation thickness. Although CMS dense film membrane permeability is high, due to the morphology collapse during pyrolysis, a conventional CMS hollow fiber membrane experiences a permeance drop because of increased effective membrane thickness.
Asymmetric hollow fiber membranes comprise an ultra-thin dense skin layer supported by a porous substructure. Asymmetric hollow fiber membranes can be formed via a dry-jet/wet quench spinning process illustrated in FIG. 4 a . The polymer solution used for spinning is referred to as “dope”. Dope composition can be described in terms of a ternary phase diagram as shown in FIG. 4 b.
Polymer molecular weight and concentration are closely correlated to viscosity and the mass transfer coefficient of the dope which affects the overall morphology of hollow fibers. The ratio of solvents to that of non-solvents should be adjusted in order to keep the dope in the 1-phase region close to the binodal. The amount of volatile component in the dope is a key factor for successful skin layer formation.
The dense skin layer is formed by evaporation of volatile solvents which drives the dope composition toward the vitrified region (indicated by dashed line indicated by the “Skin Layer Formation” arrow in FIG. 4 b ). The porous substructure is formed when the dope phase separates in the quench bath and enters into a 2-phase region (indicated by dashed line indicated by the “Substructure Formation” arrow in FIG. 4 b ).
In this way, a desirable asymmetric morphology comprising a dense selective skin layer with a porous support structure is formed. In the process of FIG. 4 a , the dope and bore fluid are coextruded through a spinneret into an air gap (“dry-jet”), where a dense skin layer is formed and then immersed into an aqueous quench bath (“wet-quench”), where the dope phase separates to form a porous substructure and can support the dense skin layer. After phase separation in the quench bath, vitrified fibers are collected by a take-up drum and kept for solvent exchange. The solvent exchange technique can play a critical role in maintaining the pores formed in the asymmetric hollow fiber
Thus, during the process of fiber spinning, as shown in FIG. 4 a , sub-structure pores are formed by the exchange of solvent molecules in a dope solution with non-solvent water molecules in a quench bath during a phase separation process of the polymer from the dope solution. The pores formed do not allow a uniform well-packed distribution of polymer chains for the asymmetric hollow fiber morphology. Hence, this expanded distribution of polymer chains in the precursor fiber can be considered as a thermodynamically unstable state, promoting the tendency for the sub-structure morphology collapse in CMS hollow fibers when sufficient segmental mobility exists before pyrolysis is complete. In this case, during pyrolysis, the porous morphology of the precursor fiber turns into a thick dense collapsed layer. This change in the membrane morphology is seen to start at the glass transition temperature (T g ) of the polymer precursor. Under heat treatment above T g , the un-oriented polymer chains enter into a soft and viscous zone which increases the chains mobility enabling them to move closer to each other. This heat treatment increases the chain packing density, resulting in the sub-structure collapse. The relaxation of the polymer precursor chains under the strong heat treatment is a primary cause for pore collapse.
Studies on the mechanism of sub-structure collapse at T g for CMS fibers, such as Matrimid® CMS hollow fibers, and some methods to try to compensate for the membrane collapse issue have been performed in the past. For example, in order to test the hypothesis of sub-structure collapse at T g , permeance and SEM characterization were performed shown in FIGS. 5 a and 5 b . The asymmetric Matrimid® precursor fiber was heated up to 320° C. (T g of Matrimid ˜315° C.) with 10 minutes of thermal soak time under vacuum atmosphere (˜1 mtorr). The same fiber after heat-treatment at T g is pyrolyzed using the standard pyrolysis temperature protocol, FIG. 5 a , under the same vacuum atmosphere.
FIG. 5 b illustrates the permeance drop experienced in CMS asymmetric hollow fiber membranes due to the sub-structure collapse occurring at T g , tested at 100 psia and 35° C. As shown in FIG. 5 b , the CO 2 permeance of Matrimid® fiber heat-treated at T g (solid square) suffers a significant permeance drop when compared to the precursor (solid diamond) and CMS hollow fiber permeance (solid triangle). Even a short soak time of ˜10 minutes at T g is sufficient for the permeance to drop down to the maximum possible extent (0.13 GPU), which is essentially equivalent to the thickness normalized precursor dense film productivity (0.2 GPU—solid point). Because of the permeance drop, the advantage of having a high transport flux in an asymmetric precursor fiber is lost significantly or completely and the fiber can be treated as a precursor dense film with similar thickness.
The significant permeance drop of the precursor fiber at T g indicates that the morphology of CMS fiber is essentially completely collapsed at T g . The increase in CMS permeance (solid triangle) over the collapsed fiber is due to decomposition of volatile compounds during pyrolysis. For the collapse of CMS fibers, an important temperature zone is between the glass transition T g and decomposition T d . Once the temperature crosses T g and enters the rubbery region the amorphous rubbery polymer can flow, but the sieving structure does not form until the polymer begins to decompose. Therefore, minimizing the time the CMS fibers experience temperatures between these zones without introducing defects usually provides the best way to prevent or reduce permeance loss while maintaining good separation ability. But, in practice it is observed that heating at extremely fast rates leads to the creation of defects, which reduces the separation ability. Therefore, an optimum heating rate must be determined experimentally.
FIG. 6 a is a SEM image of Matrimid® fiber after heat treatment at T g , depicting the collapse morphology observed in the final CMS fibers obtained from the same precursor fiber morphology as shown in FIG. 6 b.
Conventional techniques that have been attempted to reduce or eliminate substructure collapse for polymer precursors, such as Matrimid® precursor, include, but are not limited to: puffing the porous support of polymer precursor with “puffing agents”; thermally stabilizing the fiber below the glass transition temperature T g ; and crosslinking the polymer chain in order to avoid densification.
Possible “puffing agents” are species which can decompose into large volatile byproducts upon heating and leave void volume in the carbon after decomposition. One such puffing technique includes the use of polyethylene glycol (PEG). PEG can have an “unzipping effect” upon heating at higher temperatures. Essentially all of the PEG molecules can be seen to unzip at ceiling temperatures of ˜350° C. By puffing PEG in the pores before pyrolysis, it was attempted to prevent the collapse near the Matrimid® T g (˜315° C.). The comparison of both the TGA curves for Matrimid® and PEG (Mol wt: 3400) is shown in FIG. 7 .
An advantage of using PEG is that it is soluble in water and is readily absorbed in the pores in an economical post fiber spinning step. Nevertheless, substructure collapse was seen to still occur even after PEG puffing upon pyrolysis. Without being held to any particular theory of operation, it is believed that the reason why PEG puffing does not appreciably impact sub-structure collapse is due to the wide temperature range of collapse, e.g. from T g ˜315° C. to decomposition point ˜425° C. PEG puffing is presumably not successful in stabilizing the pores, as collapse starts before the unzipping temperature of the PEG.
Pre-pyrolysis thermal stabilization of polymer precursors has also been attempted using conventional methods in both oxidative and non-oxidative atmospheres. In preliminary work, fibers were pre-heated in a furnace at 270° C., which is below the T g , for time duration of 48 hours for pre-stabilization. After heat treatment, pyrolysis was performed using a standard protocol. Testing showed that the temperature stabilization of the pores did not make any significant impact on collapse for Matrimid®.
Another conventional method attempted is to crosslink the polymer precursor prior to pyrolysis. For example, researchers attempting to solve other issues have in the past attempted to crosslink precursors such as Matrimid® using UV radiation and diamine cross linkers. Such conventional crosslinking techniques using diamine linkers for Matrimid® based precursors have proven to be unsuccessful. As shown in the SEM images FIGS. 8 a and 8 b , the collapse is still observed in resultant CMS from diamine-crosslinked Matrimid® precursor fiber. Studies have indicated the diamine crosslinking to be reversible when heated at higher temperatures.
In addition to substructure collapse problems, a second challenge to CMS scale up for commercial viability is producing a large amount of CMS in a single pyrolysis run. One option in overcoming scale up problems is to pyrolyze the polymer precursor fibers in bundles but still obtain individual CMS fibers with the same or similar separation performance as non-bundled. Using conventional techniques, when pyrolyzed in bundles, polymer precursor flow can not only cause substructure collapse, but can also cause the fibers to “stick” together. When using unmodified precursor fibers according to conventional techniques, it is often necessary to separate the fibers from touching (or sticking) to each other during pyrolysis.
Thus, there is an unmet need in the art for thermally stabilized polymer precursors and asymmetric CMS hollow fiber membranes.
BRIEF SUMMARY OF THE INVENTION
Briefly described, in an exemplary form, the present invention limits or prevents the sub-structure collapse that conventionally occurs during the thermal transition of a polymer at the glass transition temperature (T g ) by stabilizing the polymer precursor before it experiences the thermal transition. The resulting polymers provide superior CMS membranes that show enhanced gas separation capability. In an exemplary embodiment, the CMS fibers are hollow fibers having exceptional separation efficiency while avoiding product adherence and reducing or eliminating the conventional drop in transport flux caused by sub-structure collapse and densification of the porous morphology when the polymer precursor is not stabilized prior to pyrolysis.
An exemplary polymer permits passage of the desired gases to be separated, for example carbon dioxide and methane. Preferably, the polymer permits one or more of the desired gases to permeate through the polymer at different diffusion rates than other components, such that one of the individual gases, for example carbon dioxide, diffuses at a faster rate than methane through the polymer.
For use in making carbon molecular sieve membranes for separating CO 2 and CH 4 , the most preferred polymers include the polyimides Ultem® 1000, Matrimid® 5218, 6FDA/BPDA-DAM, 6FDA-6FpDA, and 6FDA-IPDA.
Examples of other exemplary polymers include substituted or unsubstituted polymers and may be selected from polysulfones; poly(styrenes), including styrene-containing copolymers such as acrylonitrilestyrene copolymers, styrene-butadiene copolymers and styrene-vinylbenzylhalide copolymers; polycarbonates; cellulosic polymers, such as cellulose acetate-butyrate, cellulose propionate, ethyl cellulose, methyl cellulose, nitrocellulose, etc.; polyamides and polyimides, including aryl polyamides and aryl polyimides; polyethers; polyetherimides; polyetherketones; poly(arylene oxides) such as poly(phenylene oxide) and poly(xylene oxide); poly(esteramide-diisocyanate); polyurethanes; polyesters (including polyarylates), such as poly(ethylene terephthalate), poly(alkyl methacrylates), poly(acrylates), poly(phenylene terephthalate), etc.; polypyrrolones; polysulfides; polymers from monomers having alpha-olefinic unsaturation other than mentioned above such as poly (ethylene), poly(propylene), poly(butene-1), poly(4-methyl pentene-1), polyvinyls, e.g., polyvinyl chloride), poly(vinyl fluoride), poly(vinylidene chloride), poly(vinylidene fluoride), poly(vinyl alcohol), poly(vinyl esters) such as poly(vinyl acetate) and poly(vinyl propionate), poly(vinyl pyridines), poly(vinyl pyrrolidones), poly(vinyl ethers), poly(vinyl ketones), poly(vinyl aldehydes) such as poly(vinyl formal) and poly(vinyl butyral), poly(vinyl amides), poly(vinyl amines), poly(vinyl urethanes), poly(vinyl ureas), poly(vinyl phosphates), and poly(vinyl sulfates); polyallyls; poly(benzobenzimidazole); polyhydrazides; polyoxadiazoles; polytriazoles; poly(benzimidazole); polycarbodiimides; polyphosphazines; etc., and interpolymers, including block interpolymers containing repeating units from the above such as terpolymers of acrylonitrile-vinyl bromide-sodium salt of para-sulfophenylmethallyl ethers; and grafts and blends containing any of the foregoing. Typical substituents providing substituted polymers include halogens such as fluorine, chlorine and bromine; hydroxyl groups; lower alkyl groups; lower alkoxy groups; monocyclic aryl; lower acyl groups and the like. It is preferred that the membranes exhibit a carbon dioxide/methane selectivity of at least about 10, more preferably at least about 20, and most preferably at least about 30.
Preferably, the polymer is a rigid, glassy polymer as opposed to a rubbery polymer or a flexible glassy polymer. Glassy polymers are differentiated from rubbery polymers by the rate of segmental movement of polymer chains. Polymers in the glassy state do not have the rapid molecular motions that permit rubbery polymers their liquid-like nature and their ability to adjust segmental configurations rapidly over large distances (>0.5 nm). Glassy polymers exist in a non-equilibrium state with entangled molecular chains with immobile molecular backbones in frozen conformations. As discussed, the glass transition temperature (T g ) is the dividing point between the rubbery or glassy state. Above the T g , the polymer exists in the rubbery state; below the T g , the polymer exists in the glassy state. Generally, glassy polymers provide a selective environment for gas diffusion and are favored for gas separation applications. Rigid, glassy polymers describe polymers with rigid polymer chain backbones that have limited intramolecular rotational mobility and are often characterized by having high glass transition temperatures (T g >150° C.).
In rigid, glassy polymers, the diffusion coefficient tends to control selectivity, and glassy membranes tend to be selective in favor of small, low-boiling molecules. The preferred membranes are made from rigid, glassy polymer materials that will pass carbon dioxide, hydrogen sulfide and nitrogen preferentially over methane and other light hydrocarbons. Such polymers are well known in the art and include polyimides, polysulfones and cellulosic polymers.
The present invention can comprise a modified polymer precursor for use in the production of asymmetric hollow fiber CMS membranes for gas separation. Embodiments of the current invention are directed at the production of CMS membranes for the separation of CO 2 and H 2 S from hydrocarbon containing streams. In other embodiments, CMS membranes could be used for the separation of nitrogen from natural gas, the separation of oxygen from air, the separation of hydrogen from hydrocarbons, and the separation of olefins from paraffins of similar carbon number. Embodiments of the present invention are directed to stabilizing polymer precursors, preferably to maintain or improve CMS membrane performance after pyrolysis. The present invention, in various embodiments, is an asymmetric carbon molecular sieve membrane formed from a polymer precursor modified using a modifying agent. In some embodiments, the modifying agent can be a silane optionally substituted with a vinyl and/or an alkoxy group. In an embodiment, the modifying agent can be a vinyl alkoxy silane, or a vinyl trialkoxy silane. In an embodiment, vinyl triethoxy silane or vinyl trimethoxy silane (VTMS), particularly VTMS, can be used as the modifying agents for chemical precursor treatment. In some further embodiments, a precursor is at least partially thermally and/or physically stabilized by exposing VTMS to the precursor.
In one exemplary embodiment, the invention is a process for modifying a polymer precursor for use as a substantially non-collapsed, asymmetrical carbon membrane comprising the steps of providing the polymer precursor in a contacting vessel, providing a modifying agent in the contacting vessel, and allowing at least a portion of the polymer precursor to contact at least a portion of the modifying agent in the contacting vessel to provide for the modification of at least a portion of the polymer precursor to create a modified polymer precursor that when pyrolyzed creates a substantially non-collapsed, asymmetrical carbon membrane. In some embodiments, the polymer precursor includes a polymer selected from the group consisting of Matrimid® and 6FDA:BPDA-DAM and the modifying agent is vinyl trimethoxy silane.
In further embodiments, the step of modifying the polymer precursor with modifying agent in the contacting vessel comprises heating the contacting vessel to raise the temperature of contents in the contacting vessel within a reaction temperature range for a period of time. In some additional embodiments, the reaction temperature range wherein the reaction temperature range is selected from the group consisting of: from approximately 25° C. to approximately the polymer precursor glass transition temperature; from approximately 100° C. to approximately the polymer precursor glass transition temperature; and from approximately 100° C. to approximately 250° C.
In some embodiments, the period of time is from approximately 30 minutes to approximately 24 hours.
In some embodiments, the polymer precursor is an asymmetric hollow polymer fiber, wherein, in still further embodiments, the polymer precursor is an aromatic imide polymer precursor fiber.
In additional embodiments, the process further comprises pyrolyzing the modified polymer precursor by heating the polymer precursor in a pyrolysis chamber to at least a temperature at which pyrolysis byproducts are evolved. In further embodiments, the process further comprises flowing an inert gas through the pyrolysis chamber during said heating step. In additional embodiments, the pyrolysis chamber and the contacting vessel are the same.
In further embodiments, the modified polymer precursor is a composite structure comprising a first polymer supported on a porous second polymer support. In still further embodiments, the polymer precursor is a material that can be pyrolyzed to form CMS membrane, but whose asymmetric structure does not collapse during pyrolysis.
In another embodiment, the present invention is a modified polymer precursor for a substantially non-collapsed, asymmetrical carbon membrane created by the steps of providing the polymer precursor in a contacting vessel, providing a modifying agent in the contacting vessel, and allowing at least a portion of the polymer precursor to contact at least a portion of the modifying agent in the contacting vessel to provide for the modification of at least a portion of the polymer precursor to create a modified polymer precursor that when pyrolyzed creates an asymmetrical carbon membrane.
In a still further embodiment, the present invention is a process for reducing adhesion between a plurality of modified polymer precursors for as a substantially non-collapsed, asymmetrical carbon membrane, comprising the steps of providing the plurality of polymer precursors in a contacting vessel, providing a modifying agent in the contacting vessel, allowing at least a portion of the plurality of polymer precursors to contact at least a portion of the modifying agent in the contacting vessel to provide for the modification of at least a portion of the plurality of polymer precursors to create the plurality of modified polymer precursors that when pyrolyzed create a plurality of substantially non-collapsed, asymmetrical carbon membranes, and wherein at least a portion of the plurality of modified polymer precursors do not adhere to each other.
In another exemplary embodiment, the present invention is a process for forming a carbon membrane using precursor pre-treatment comprising providing a polymer precursor, pre-treating at least a portion of the polymer precursor, and subjecting the pre-treated polymer precursor to pyrolysis, wherein the step of pre-treating at least a portion of the polymer precursor provides at least a 300% increase in the gas permeance of the asymmetric carbon membrane in contrast to the carbon membrane without precursor pre-treatment.
The step of pre-treating at least a portion of the polymer precursor can provide at least a 400% increase in the gas permeance of the asymmetric carbon membrane in contrast to the carbon membrane without precursor pre-treatment.
The step of pre-treating at least a portion of the polymer precursor can provide an increase in the gas separation selectivity of the carbon membrane in contrast to the carbon membrane without precursor pre-treatment.
The polymer precursor can comprise a soluble thermoplastic polyimide. The polymer precursor can comprise an asymmetric hollow polymer fiber. The polymer precursor can comprises an aromatic imide polymer precursor.
The step of pre-treating at least a portion of the polymer precursor can comprise chemically modifying the polymer precursor.
In another exemplary embodiment, in a process of forming a carbon membrane from a polymer precursor including the steps of providing a polymer precursor and subjecting the polymer precursor to pyrolysis, wherein the carbon membrane has a first gas permeance and a first gas separation selectivity, the present invention comprises the improvement of the step of pre-treating at least a portion of the polymer precursor prior to pyrolysis such that after pre-treatment and pyrolysis, the improved carbon membrane has a second gas permeance and a second gas separation selectivity, wherein at least one of the second gas permeance or second gas separation selectivity is greater than the respective first gas permeance or first gas separation selectivity.
In another exemplary embodiment, the present invention is a process for modifying a polymer precursor for use as a carbon membrane comprising providing a polymer precursor in a vessel, providing a modifying agent in the vessel, contacting at least a portion of the modifying agent with the polymer precursor in the vessel to provide for the modification of at least a portion of the polymer precursor, and subjecting the modified polymer precursor to pyrolysis forming the carbon membrane.
The carbon membrane can comprise a hollow fiber membrane, a hollow fiber membrane comprising an asymmetric membrane, and/or a substantially non-collapsed, asymmetric hollow fiber membrane.
The modifying agent can be vinyl trimethoxy silane or vinyl triethoxy silane, preferably vinyl trimethoxy silane.
The process can further comprise providing an initiator in the vessel, and/or flowing an inert gas during pyrolysis.
The polymer precursor can be a composite structure comprising a first polymer supported on a porous second polymer. An asymmetric hollow fiber membrane can comprise a group of membrane fibers that are in contact with one another during the pyrolysis process and do not adhere to one another after pyrolysis.
In another exemplary embodiment, the present invention is a process for making a carbon membrane comprising providing a polymer precursor comprising a soluble thermoplastic polyimide, chemically modifying the polymer precursor with a modifying agent, and heating the chemically modified precursor in a chamber to at least a temperature at which pyrolysis byproducts are evolved, wherein the carbon membrane has a CO 2 permeance (GPU) of greater than 10 and a CO 2 /CH 4 selectivity greater than 88 when tested in pure CO 2 and CH 4 gas streams at 100 psia at 35° C. The modifying agent can comprise vinyl trimethoxy silane.
In another exemplary embodiment, the present invention is a process for making a carbon membrane comprising providing a polymer precursor comprising a soluble thermoplastic polyimide, chemically modifying the polymer precursor with a modifying agent, and heating the chemically modified precursor in a chamber to at least a temperature at which pyrolysis byproducts are evolved, wherein the carbon membrane has a CO 2 permeance (GPU) of greater than 53 and a CO 2 /CH 4 selectivity greater than 48 when tested in pure CO 2 and CH 4 gas streams at 100 psia at 35° C.
In another exemplary embodiment, the present invention is a carbon molecular sieve membrane formed by one of the processes disclosed above
These and other objects, features, and advantages of the present invention will become more apparent upon reading the following specification in conjunction with the accompanying drawing figures.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 a is an illustration of the chemical structure for Matrimid®.
FIG. 1 b is an illustration of the chemical structure for 6FDA:BPDA-DAM.
FIG. 2 a is a scanning electron microscopy (SEM) image of a Matrimid® based precursor membrane.
FIG. 2 b is an SEM image of CMS membrane skin with morphology collapse from a Matrimid® precursor.
FIG. 3 a is an SEM image of a 6FDA/BPDA-DAM based precursor membrane.
FIG. 3 b is an SEM image of CMS membrane skin with morphology collapse from a 6FDA/BPDA-DAM precursor.
FIG. 4 a is an illustration of a conventional dry-jet/wet-quench spinning process for producing asymmetric hollow fiber membranes.
FIG. 4 b is a ternary phase diagram showing the asymmetric membrane formation process of FIG. 4 a.
FIG. 5 a illustrates the pyrolysis temperature protocol used for the formation of conventional CMS hollow fibers.
FIG. 5 b illustrates the permeance drop experienced in CMS hollow fiber membranes from Matrimid® precursor due to the substructure collapse occurring at T g .
FIGS. 6 a and 6 b are SEM images of fiber after the heat treatment at T g depicting the collapse morphology ( 6 a ) and skin morphology of a precursor fiber before the heat treatment ( 6 b ).
FIG. 7 illustrates a comparison of both the TGA curves for Matrimid® and PEG (Mol wt: 3400).
FIGS. 8 a and 8 b are SEM images of the diamine-crosslinked Matrimid® precursor fiber membrane ( 8 a ) and resultant CMS fiber membrane still indicating the collapse ( 8 b ).
FIG. 9 is an illustration of an exemplary CMS precursor fiber thermal stabilization process according to various embodiments of the present invention.
FIG. 10 is an illustration of an exemplary pyrolysis process than can be used with various embodiments of the present invention.
FIGS. 11 a and 11 b are SEM images showing improved substructure morphology for Matrimid®.
FIGS. 12 a and 12 b are SEM images showing improved substructure morphology for 6FDA:BPDA-DAM.
FIGS. 13 a and 13 b show test results for CMS fibers made according to various embodiments of the present invention compared to CMS fibers made according to conventional techniques.
FIG. 14 a shows conventional CMS fibers adhered to one another.
FIG. 14 b shows CMS fibers made according to various embodiments of the present invention not adhering appreciably to each other.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Although preferred embodiments of the invention are explained in detail, it is to be understood that other embodiments are contemplated. Accordingly, it is not intended that the invention is limited in its scope to the details of construction and arrangement of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or carried out in various ways. Also, in describing the preferred embodiments, specific terminology will be resorted to for the sake of clarity.
It must also be noted that, as used in the specification and the appended claims, the singular forms “a,” “an” and “the” include plural referents unless the context clearly dictates otherwise.
Also, in describing the preferred embodiments, terminology will be resorted to for the sake of clarity. It is intended that each term contemplates its broadest meaning as understood by those skilled in the art and includes all technical equivalents which operate in a similar manner to accomplish a similar purpose.
Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value.
By “comprising” or “containing” or “including” is meant that at least the named compound, element, particle, or method step is present in the composition or article or method, but does not exclude the presence of other compounds, materials, particles, method steps, even if the other such compounds, material, particles, method steps have the same function as what is named.
It is also to be understood that the mention of one or more method steps does not preclude the presence of additional method steps or intervening method steps between those steps expressly identified. Similarly, it is also to be understood that the mention of one or more components in a device or system does not preclude the presence of additional components or intervening components between those components expressly identified.
Various embodiments of the present invention are directed to stabilizing polymer precursors, preferably to maintain or improve CMS membrane performance after pyrolysis. The present invention described hereinafter is described in terms of “carbon” for purposes of clarification. It should be noted, however, that the scope of the present invention is not limited to “carbon” molecular sieve membrane, as other “non-carbon” membranes may be produced using various embodiments of the present invention. Various embodiments of the present invention use an improved technique of modifying CMS membranes and polymer precursors to CMS membranes.
As discussed above, various aspects of this disclosure are directed to modification of a polymer precursor to produce a modified polymer precursor. The modified polymer precursor can then be pyrolyzed to produce the CMS fiber. As used herein, “polymer precursor” is intended to encompass the asymmetric hollow fiber prepared using one of the exemplary polymers discussed previously. The polymer precursor can be prepared according to the dry-jet/wet quench spinning process described previously. However, other processes that might produce an asymmetric hollow fiber can also be used. “Polymer precursor” as used herein might also be described as a fiber precursor, or simply precursor, or the generic or trade name polymer precursor. For example, Matrimid® precursor, Matrimid® precursor fiber, and asymmetric Matrimid® precursor fiber are all intended to describe a polymer precursor based on the Matrimid® polymer 5(6)-amino-1-4′-aminophenyl-1,3-trimethylindane. Similarly, a modified polymer precursor can be a polymer precursor that has been modified with a modifying agent, and may be similarly designated modified precursor, modified fiber precursor, modified Matrimid® precursor, and so forth.
The disclosure, in various embodiments, is an asymmetric carbon molecular sieve membrane formed from a polymer precursor modified using a modifying agent. The modifying agent can also be referred to herein as a chemical modifying agent, and the process of modifying can also be referred to as chemically modifying. In some embodiments, vinyl trimethoxy silane is used as the modifying agent for chemical precursor treatment, but other silanes can also be employed as a modifying agent. In general, the silane for use in this disclosure can be described by a formula R 1 R 2 R 3 R 4 Si, where each of R 1 , R 2 , R 3 , and R 4 are independently vinyl, C 1 -C 6 alkyl, —O-alkyl, or halide, with the proviso that the silane contain at least one vinyl group and at least one —O-alkyl or halide. The O-alkyl can be any C 1 to C 6 alkyloxy (or alkoxy) group, including, for example, methoxyl, ethoxy, propoxy, butoxy and so forth, preferably methoxy or ethoxy. Without wishing to be bound by theory, the modifying agent is thought to be a compound that can generate an Si—O—Si linkage during modification of the polymer precursor. Therefore, the modifying agent can be a monosilane, such as for example, vinyl trimethoxysilane, vinyl triethoxysilane, vinyl dimethoxychlorosilane, vinyl diethoxychlorosilane, vinyl methoxydichlorosilane, vinyl ethoxydichlorosilane, or vinyl trichlorosilane. The modifying agent could also be a short chain oligosiloxane, where one or more of the R 1 R 2 R 3 R 4 is an —O-silyl having similar substitution to the monosilane, for example, a disiloxane or trisiloxane having at least one vinyl and at least one alkoxy or halide on the oligosilane such as vinyl pentamethoxydisiloxane or divinyl tetramethoxydisiloxane. Preferably the modifying agent can be a vinyl trimethoxysilane or a vinyl triethoxy silane.
In some further embodiments, a precursor polymer is at least partially thermally and/or physically stabilized by exposing vinyl trimethoxysilane (VTMS) to the precursor. It should be understood that, although various embodiments of the present invention are discussed using vinyl trimethoxy silane and various precursors, the present invention is not limited to the use of vinyl trimethoxy silane or the precursors discussed. Other pretreatment chemicals and other precursors suitable for the purposes of various embodiments of the present invention having similar chemical and mechanical characteristics are considered to be within the scope of the present invention.
In some embodiments, the modification of the precursor with VTMS is performed by adding VTMS and precursor fibers in a contacting device for different time durations. Further, in some embodiments, the precursor and modification agent are heated in a reaction vessel under auto thermal pressure prior to the actual pyrolysis step.
FIG. 9 is an illustration of an exemplary process according to various embodiments of the present invention. Precursor fiber 300 is added to a modifying agent 302 , such as VTMS, in contacting device 320 . Precursor fiber 300 can be various conventional asymmetric hollow fibers suitable for use, including, but not limited to, Matrimid® and 6FDA:BPDA-DAM. For VTMS modification on Matrimid® precursor, precursor fibers 300 can be simply immersed in excess of VTMS liquid 302 in a sealed contacting device 320 without any additional chemical. Contacting device 320 can be maintained at room temperature or can be heated in a heated convection oven (˜200° C.) for about 30 minutes to allow for the modification process. If heated, after the reaction, reaction tube 320 is cooled down and fibers 304 are removed from the liquid 302 . Fibers 304 are then placed at 150° C. under vacuum for 6 hours to remove excess modification agent 302 .
Without being bound to any specific theory of operation, it is believed that the VTMS modifies the precursor prior to thermal decomposition of the main polymer precursor to form carbon. It should be noted that the present invention is not limited to precursor fibers having aromatic rings. It should be noted that various other precursor fibers having aromatic rings may also be suitable, and are thus, considered to be within the scope of the present invention.
For example, and not by way of limitation, various embodiments of the present invention can use polyimide precursor molecule 6FDA:BPDA-DAM. As discussed prior, a purpose of modifying silane molecules on precursors is to give the stability to the polymer chains during the heat treatment above T g . When using unmodified 6FDA:BPDA-DAM, the membrane collapse can be smaller than other fibers, such as unmodified Matrimid®, because of various differences between the structures. For example, 6FDA:BPDA-DAM has a higher glass transition temperature of than Matrimid®. Also, bulkier-CF 3 groups of 6FDA:BPDA-DAM leaves the molecule during pyrolysis. Other polyimides made from the 6FDA dianhydride monomer are expected to act similar to 6FDA:BPDA-DAM when used as precursors and treated with a modifying agent such as VTMS.
EXPERIMENTAL METHOD
Materials
The glassy polymers used in the study were Matrimid® 5218 and 6FDA:BPDA-DAM. The polymers were obtained from the sources, Matrimid® 5218 from Huntsman International LLC and 6FDA:BPDA-DAM was lab-custom synthesized from Akron Polymer Systems (APS). The vinyl trimethoxy silane was obtained from Sigma-Aldrich. To obtain the above mentioned polymers one can also use other available sources or synthesize them. For example, such a polymer is described in U.S. Pat. No. 5,234,471, the contents of which are hereby incorporated by reference.
Formation of Polymer Precursor Hollow Fiber Membranes
Asymmetric hollow fiber membranes comprise an ultra-thin dense skin layer supported by a porous substructure. In the examples used for illustration purposes, asymmetric hollow fiber membranes are formed via a conventional dry-jet/wet quench spinning process, illustrated by way of example in FIG. 4 a . The present invention is not limited to any particular method or process for forming the polymer precursor. The polymer solution used for spinning is referred to as “dope”. Dope composition can be described in terms of a ternary phase diagram as shown in FIG. 4 b . The formation of defect-free asymmetric hollow fibers was followed from the process described in U.S. Pat. No. 4,902,422 the contents of which are hereby incorporated by reference.
Pre-Treatment of Polymer Precursor Fibers
For VTMS modification on a Matrimid® precursor, the fibers are immersed in excess of VTMS liquid in a closed contacting vessel, as illustrated by way of example in FIG. 9 . The modification was performed by soaking the fibers in VTMS for 24 hours at room temperature (25° C.) which gave similar observations as shown in the examples discussed later.
In a second embodiment, the VTMS was contacted with Matrimid® precursor in a closed cell and heated in a convection oven to 200° C. for 30 minutes. After the heating, the cell was cooled down to room temperature (˜25° C.) and the fibers removed from the liquid. The fibers were then placed at 150° C. under vacuum for 6 hours to remove the excess VTMS (boiling point of VTMS—135° C.).
Pyrolysis
The polymer fibers were placed on a stainless steel wire mesh and held in place by wrapping a length of wire around the mesh and fibers. The mesh support was loaded to a pyrolysis setup, as illustrated in FIG. 10 . For each polyimide precursor, a different pyrolysis temperature and atmosphere were used.
Matrimid®:
Final pyrolysis temperature-650° C., temperature profile:
1. 50° C. to 250° C. at a ramp rate of 13.3° C./min 2. 250° C. to 635° C. at a ramp rate of 3.85° C./min 3. 635° C. to 650° C. at a ramp rate of 0.25° C./min 4. Soak for 2 hours at 650° C.
Pyrolysis atmosphere: Ultra High purity Argon (˜99.9%)
6FDA:BPDA/DAM:
Final pyrolysis temperature-550° C., temperature profile:
a. 50° C. to 250° C. at a ramp rate of 13.3° C./min b. 250° C. to 535° C. at a ramp rate of 3.85° C./min c. 535° C. to 550° C. at a ramp rate of 0.25° C./min d. Soak for 2 hours at 550° C.
Pyrolysis atmosphere: Argon with 26.3 ppm of oxygen
The pyrolysis system used in this study is depicted in FIG. 10 . A temperature controller (Omega Engineering, Inc.,) was used to heat a furnace Thermocraft®, Inc. and fiber support kept in the quartz tube (National Scientific Co.). An assembly of a metal flange with silicon O-rings (MTI Corporation) was used on both ends of a quartz tube. An oxygen analyzer (Cambridge Sensotec Ltd., Rapidox 2100 series, Cambridge, England with ±1% accuracy between 10 −20 ppm and 100%) was integrated to monitor an oxygen concentration during the pyrolysis process.
CMS Membrane Testing Modules
CMS fibers were tested in a single fiber module and constructed as described in US Patent Publication No. 2002/0033096 A1 by Koros et al., the contents of which are hereby incorporated by reference. CMS fiber module were tested in a constant-volume variable pressure permeation system for both pure and mixed gas feeds similar to the one described in US Patent Publication No. 2002/0033096 A1 by Koros et al.
Experimental Results Review
Example 1
CMS membranes from Matrimid® precursor where prepared as described in the experimental section above. The validation for the example is shown below:
SEM Images of the CMS Fiber Membranes from the VTMS Modified Precursor
CMS membranes from Matrimid® modified precursors shows an improved morphology under SEM. FIGS. 11 a and 11 b are SEM images showing improved substructure morphology for Matrimid®.
Transport Properties for CMS from Modified Precursors
CMS—VTMS Modified Matrimid®:
The CMS module was tested using pure CO 2 and pure CH 4 at 100 psig with an evacuated permeate. The permeance of the pretreated CMS increased by ˜4× over the untreated CMS with almost no change in selectivity, as shown in TABLE 1.
TABLE 1
Comparison of the CMS from modified and unmodified
Matrimid ® precursors pyrolyzed at
650° C. for pure gas feed.
CO 2 PERMEANCE
SELECTIVITY
(GPU)
(CO 2 /CH 4 )
CMS With VTMS Modified
38
92
Precursor
CMS With Unmodified Precursor
10
88
Example 2
CMS membranes from 6FDA:BPDA-DAM precursor where prepared as described in the experimental section above. The validation for the example is shown below:
SEM Images of the CMS Fiber Membranes from the VTMS Modified Precursor
CMS membrane from 6FDA:BPDA-DAM modified precursors show an improved morphology under SEM. FIGS. 12 a and 12 b are SEM images showing improved substructure morphology for 6FDA:BPDA-DAM.
Transport Properties for CMS from Modified Precursors
CMS VTMS Modified 6FDA:BPDA-DAM:
The CMS VTMS modified 6FDA module is tested for both pure gas and mixed gas (50% CO 2 -50% CH 4 ) streams. Comparison of separation performance for pure gas feed with the unmodified CMS performance values are shown in TABLE 2.
TABLE 2
Comparison of the CMS from modified and unmodified 6FDA:BPDA-
DAM precursors pyrolyzed at 550° C. for pure gas feed.
CO 2 PERMEANCE
SELECTIVITY
(GPU)
(CO 2 /CH 4 )
CMS With VTMS Modified
245
51
Precursor
CMS With Unmodified Precursor
53
48
In the case of 6FDA:BPDA-DAM, the permeance enhancement is similar to what was shown for Matrimid® (˜5×).
In order to test the stability of the CMS VTMS modified 6FDA fibers, the CMS module was tested for mixed gas up to 800 psia and compared with the performance of CMS 6FDA:BPDA-DAM fibers made according to various methods as taught by Koros et al. in U.S. Pat. No. 6,565,631. FIGS. 13 a and 13 b show comparisons of the performance of the VTMS treated CMS of this embodiment and the fibers produced by the method taught in U.S. Pat. No. 6,565,631. The CMS fibers of this embodiment have ˜ 2 × the permeance of the fibers from U.S. Pat. No. 6,565,631 while maintaining a similar selectivity.
Example 3
Anti-Stick Property for VTMS Modified Precursor Fibers
By using various embodiments of the present invention, the amount of sticking between fibers can be reduced or eliminated while maintaining the good separation performance. A control run with the unmodified Matrimid® precursor fibers was performed where multiple fibers were bundled close to one another during the pyrolysis, shown in FIG. 14 a . After the pyrolysis the CMS unmodified fibers were stuck to one another and impossible to separate the fibers without causing serious damage or breakage. The same experiment was performed on Matrimid® precursors modified according to various embodiments of the present invention, as shown in FIG. 14 b . After pyrolysis these CMS VTMS modified fibers do not stick together and achieve an “anti-stick” property.
In addition to the “anti-stick” property, it can also be desirable that CMS fibers have good separation performance. The permeance of bundled fibers was compared to both non-bundled untreated fibers, and bundled non-treated fibers shown in TABLE 3. The untreated fibers were not testable because they were stuck together.
TABLE 3
Comparison of the permeance of bundled fibers with both
non-bundled, treated fibers and bundled, non-treated fibers.
(Testing conditions: 35° C. and 100 psia pure gas).
CO 2 PERMEANCE
CO 2 /CH 4
STATE DURING PYROLYSIS
(GPU)
SELECTIVITY
CMS With VTMS Modified
33
106
Precursor (Non-Bundled)
CMS With VTMS Modified
25
117
Precursor (Bundled) - FIG. 14(b)
CMS With Unmodified
Not Possible To Test Due To
Precursor (Bundled) - FIG. 14(a)
Damage In Fibers
Numerous characteristics and advantages have been set forth in the foregoing description, together with details of structure and function. While the invention has been disclosed in several forms, it will be apparent to those skilled in the art that many modifications, additions, and deletions, especially in matters of shape, size, and arrangement of parts, can be made therein without departing from the spirit and scope of the invention and its equivalents as set forth in the following claims. Therefore, other modifications or embodiments as may be suggested by the teachings herein are particularly reserved as they fall within the breadth and scope of the claims here appended. | 4y
|
This application is a division, of application Ser. No. 10/225,317, filed Aug. 21, 2002, (status, abandoned, pending, etc.).
FIELD OF THE INVENTION
This invention relates to a mounting system and, more specifically, to a display mounting system that can coactively isolate a display from shock and vibration forces.
CROSS REFERENCE TO RELATED APPLICATIONS
None
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
None
REFERENCE TO A MICROFICHE APPENDIX
None
BACKGROUND OF THE INVENTION
In order to protect equipment from shock and vibration forces shock isolators are employed that attenuate shock and vibration to a support structure to protect the equipment carried by the support structure. Typically, equipment such as consoles have integral visual displays which are isolated from shock and vibration as a whole console unit. The present invention provides a shock isolation system that can separately isolate the display from shock and vibration, forces, yet can be made to appear as if the display is an integral part of the console. A further feature of the invention is that the mounting system permits one to replace the display without having to remove or replace a portion of the console since the display is removably mounted on the console.
The present invention can provide shock and vibration attenuation through the coaction of two separate shock isolators, a first shock isolator that supports the display on the console and a second shock isolator that peripherally surrounds the display and coacts with the first shock isolator to provide enhanced shock and vibration attenuation.
Elastomeric isolators employed in the prior art are commonly formed into geometric 3D shapes, such as spheres, squares, right circular cylinders, cones, rectangles and the like as illustrated in U.S. Pat. No. 5,776,720. These elastomeric isolators are typically attached to a housing to protect equipment within the housing from the effects of shock and vibration.
Various elastomeric materials have been used, or suggested for use, to provide shock and/or vibration damping as stated in U.S. Pat. No. 5,766,720, which issued on Jun. 16, 1998 to Yamagisht, et al. These materials include natural rubbers and synthetic resins such as polyvinyl chlorides, polyurethane, polyamides polystyrenes, copolymerized polyvinyl chlorides, and poloyolefine synthetic rubbers as well as synthetic materials such as urethane, EPDM, styrene-butadiene rubbers, nitrites, isoprene, chloroprenes, propylene, and silicones. The particular type of elastomeric material is not critical but urethane material sold under the trademark Sorbothane® is currently employed. Suitable material is also sold by Aero E.A.R. Specialty Composites, as Isoloss VL. The registrant of the mark Sorbothane® for urethane material is the Hamiltion Kent Manufacturing Company (Registration No. 1,208,333), Kent, Ohio 44240.
Generally, the shape and configuration of elastomeric isolators have a significant effect on the shock and vibration attenuation characteristics of the elastomeric isolators.
The prior art elastomeric isolators are generally positioned to rely on an axial compression of the elastomeric material or on tension or shear of the elastomeric material. Generally, if the elastomeric isolator is positioned in the axial compressive mode the ability of the elastomeric isolator to attenuate shock and vibration is limited by the compressive characteristics of the material. On the other hand, in the axial compressive mode the elastomeric isolators can be used to provide static support to a housing, which allows a single elastomeric isolator to be placed beneath the housing to support the static weight of the housing. It is the shear type of elastomeric isolators which are preferred for use in the present invention.
SUMMARY OF THE INVENTION
A shock mount to statically and dynamically support the weight of a housing while at the same time effectively attenuating shock or vibration forces imparted to the system with the shock mount having a first shock isolator for supporting the weight of the display and an elastomer bezel extends onto a portion of the display with the bezel functioning as a second shock and vibration isolator that coacts with the first shock isolator to further attenuate shock and vibrations force to the system
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a console supported by two types of shock isolators;
FIG. 2 is a cross sectional view taken along lines 2 — 2 of FIG. 1 showing the elastomer shock isolators and an elastomer bezel carried the support structure;
FIG. 3 is a partial cross sectional view of the bezel in a tension condition to provide shock and vibration attenuation to the display;
FIG. 4 shows the support structure in cross sectional view with a removable base about to be secured to the support structure; and
FIG. 5 is a perspective view of a double triad elastomer shock isolator.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a front view of a console 10 having a display 13 supported by the shock mount of the present invention. Console 10 includes a support structure 12 and an extension 11 for holding a keyboard or the like. “Mounted to support structure 12 is display 13 which has an opaque elastomer bezel 14 having a front peripheral lip 14 a secured to a front face of a visual information displaying surface portion of the display 13 to provide an esthetically pleasing appearance over 360 degrees.” (Emphasis added.) Typically, display 13 can be any type of device that presents visual information to a user.
FIG. 2 shows a cross sectional view of the console 10 showing the support structure 12 supporting a removable base 20 . Removable base 20 include a mounting edge comprising a stepped a peripheral edge 20 a to allow one to position the removable base 20 in a mating peripheral engagement with peripheral extension 12 a on support structure 12 .
The sheet elastomer bezel 14 , which extends around the peripheral region of display 13 , has a first peripheral end or display attaching lip 14 a secured to display 13 and a second peripheral end or base attachment lip 14 b secured to removable base 20 through a set of fasteners 23 . Supporting display 13 is a first and second elastomer mount 21 and 22 . The shock isolators 21 and 22 each have a first end support surface and a second end support surface with the first end support surface and the second end support surface laterally offset other so that a force on the first end support is cantileverly supported to place the elastomer in a shear condition rather than a compression condition and a force on the second end support is cantileverly supported to place the elastomer in a shear condition rather than a compression condition. Elastomer mounts 21 , 22 are preferably of the type shown in my copending patent application Ser. No. 09/779,423 filed Feb. 28, 2001, titled DOUBLE TRIAD ELASTOMER MOUNT which is hereby incorporated by reference. The application discloses an elastomer shock isolator that is positioned in the shear or tension mode as opposed to an axial compression mode. Such elastomeric isolators provide enhanced shock and vibration attenuating characteristics in response to dynamic forces due to shock and vibration. FIG. 5 is a perspective view of the double triad one-piece shock isolator 30 disclosed in the Ser. No. 09/779,423 for providing shock and vibration attenuation while providing axially offset support to an object. Isolator 30 is a one-piece two-tetrahedron elastomer shock isolator 30 that simultaneously isolates shocks and supports a static load. Shock isolator 30 has a set of integral elastomer side walls forming a first tetrahedron elastomer shell 31 with a tetrahedron shaped cavity 31 c therein and a second tetrahedron elastomer shell 32 having a set of integral elastomer side walls forming a second tetrahedron elastomer shell with a tetrahedron shaped cavity 32 c therein.
A central axis 33 is shown extending through an apex end 32 a of elastomer shell 32 and an apex end 31 a of elastomer shell 31 . FIG. 2 shows apex end 31 a and apex end 32 a are smoothly joined to each other at junction surface 39 to form the one-piece two-tetrahedron elastomer shock isolator.
FIG. 1 shows the top tetrahedron elastomer shell 32 has a triangular shaped base end that forms a first support surface 32 b . Similarly, the bottom tetrahedron elastomer shell 31 has a triangular shaped base end that forms a second support surface 31 b . The conjunction of the apex ends of the two-tetrahedron elastomer shells provides an integral force transfer region between the triangular shaped base ends 31 b and 32 b of the two-tetrahedron elastomer shells 31 and 32 .
In order to provide shear resistance the base ends 31 b and 32 b are laterally offset with respect to the conjoined area 35 ( FIG. 3 ) which occurs at the conjunction of the apex ends of tetrahedron elastomer shells 31 and 32 . That is, a line parallel to axis 33 that extends through base end or first support surface 32 b does not extend through the conjoined area 35 between the apex of the two-tetrahedron elastomers 31 and 32 . Similarly, a line parallel to axis 33 that extends through the second base end or support surface 31 b does not extend through the conjoined area between the two apex ends 31 a and 32 a of the two-tetrahedron elastomers 31 and 32 . Consequently, forces applied to base ends produce shear within the elastomer. These type of elastomer shock isolator which functions in the shear mode is more fully shown and described in my copending application Ser. No. 09/779,423 is hereby incorporated herein by reference.
FIG. 2 shows the elastomer bezel 14 in a slack condition wherein a curvature of the elastomer bezel is visible. That is, bezel 14 is sufficiently long so as to be positioned in a curved condition which is referred to as mounting the bezel 14 in a slack condition. This condition normally occurs around the entire periphery of the display 13 when the elastomer bezel 14 is in the relaxed condition, i.e. a condition where the static forces are supported by the elastomer shock isolators 21 and 22 .
FIG. 3 shows a portion of the removable base and elastomer bezel 14 illustrating the condition when shock and vibration forces have displaced display 13 . In this condition, due to downward displacement of display 13 relative to removable base 20 , the elastomer bezel 14 is now in a taut or tension condition. When the elastomer bezel is in a tension condition as illustrated in FIG. 3 further elongation of elastomer bezel is resisted resulting in the bezel 14 coacting with the elastomer shock mount 21 to further inhibit shock and vibration forces. That is, the elastomer bezel is sufficient flexible so as to offer little resistance to flexing when in the slack mode but has sufficient internal integrity to offer substantial resistance to elongation of bezel 14 when the bezel is in the taut condition as shown in FIG. 3 . At the same time the bezel 14 provides an aesthetically pleasing appearance around the peripheral region of display 13 .
FIG. 4 shows a partial cross section of the support structure 12 and a side view of the shock isolated unit 30 with removable base 20 and bezel 14 . The peripheral lip edge 20 a of removable base forms mating engagement with the peripheral lip 12 a in support structure 12 a so a user can insert and mount the shock isolated unit 30 into the support structure 12 . This greatly facilitates replacing a display that may malfunction including any shock isolators since the shock isolated unit 30 carries the shock isolator 21 and elastomer bezel 14 as a unitary component. An operator need only secure the removable base 20 to the support structure with fasteners (not shown) and attach the display power cable 28 to the console.
While the display 13 is shown in a vertical mount the display 13 can be mounted in horizontal or any other orientation with the present invention.
The present invention also includes a method of shock isolating a display from a support housing by supporting a display 13 with an elastomer shock isolator 21 positioned on an interior region of a display 13 . One can then secure first peripheral lip 14 a of elastomer bezel to the display 13 . One can secure a second peripheral lip 14 b of the elastomer bezel 14 to the base 20 to thereby provide coactive shock and vibration protection to the display unit.
In order to produce coactive shock isolation one mounts the bezel 14 in a slack condition as shown in FIG. 2 so that the elastomer shock isolators 21 and 22 provide primary shock and vibration attenuation and the bezel 14 provides secondary shock and vibration attenuation as the bezel is brought into a taut condition.
In addition, the invention can include the step of mounting of the elastomer bezel 14 and elastomer isolators 21 , 22 to a removable base 20 to permit the unitary removable and replacement of the display 13 as a shock isolated unit as well as the step of securing the base 20 to a support structure 12 . | 4y
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CLAIM OF PRIORITY
[0001] This application claims priority from Provisional Patent Application No. 61/493,014, filed on Jun. 3, 2011 which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE DISCLOSURE
[0002] The present disclosure relates generally to storage cabinets or bins and the like, and more particularly to a bin retainer panel for use with a storage cabinet with shelves which is shipped and packed in shipping containers.
[0003] It is generally known to provide a cabinet structure into which one or more shelves are mounted. In certain applications, the shelves are compartmentalized or otherwise configured to hold screws, nuts, bolts, and other articles. The shelves are intended to be normally used in a horizontal position.
[0004] The metal storage bins or cabinets are often used in military facilities or operations. The metal storage cabinets or bins with shelves are often shipped with articles such as bolts, nuts, etc. stored within the bin with the bin on its side and with the shelves in a vertical position. As such, the bolts, nuts, screws or other parts can fall or move around during shipment. The bin or cabinet is also often shipped on its side, i.e. when the shelves are positioned vertically instead of horizontally or upright during normal use.
[0005] The cabinet or bin also has a pair of doors which are closed and locked during shipment. During use, the doors are removed from the bin which is tilted to its upright position with the shelves in the normal horizontal position.
[0006] Thus, there is a need for a retaining panel which is used for retaining articles within compartments formed by shelves of a bin during shipment which overcomes the above-mentioned deficiencies while providing better overall results.
SUMMARY OF THE DISCLOSURE
[0007] In accordance with a first aspect of the present disclosure, a cabinet structure includes shelves which form storage compartments within the cabinet. A bin retaining panel is inserted onto the storage bin and has tabs or protrusions which are received by slots or openings formed by the shelves. The bin retaining panel is preferably made of a thin sheet of metal and is bendable or flexible. The panel can be made of various suitable thicknesses. Furthermore, other suitable materials are contemplated.
[0008] The bin retaining panel also has a cut-out or opening configured to receive a lock assembly for one of the shipment container doors.
[0009] Edges of the bin retaining panel are bent up at about 90 degrees to engage with an edge of the container door. The edges on the panel also put pressure on the panel to stay in position.
[0010] A bottom end of the panel mates with the bottom of the bin. The door frame is positioned on and places pressure on the bottom of the panel.
[0011] In accordance with one aspect of the disclosure, a bin retainer panel has a planar wall having a first end having a bent edge extending along a length of the first end; and first and second side ends each having edges bent at an acute angle with respect to the planar wall; wherein the first and second side edges have a plurality of protrusions formed thereon.
[0012] In accordance with another aspect of the disclosure, a bin retainer panel has a planar wall having a first end having a bent edge and a second, opposite end comprising a bent edge; and first and second side ends wherein the first side end has an edge bent at an acute angle with respect to the planar wall, wherein at least the first side end edge has a plurality of protrusions formed thereon.
[0013] In accordance with another aspect of the disclosure, a method of using a bin retainer panel includes the steps of tilting a storage bin on its side; unlocking doors of the bin by unlocking and removing a locking member from the doors; lowering a bin retainer panel onto the bin and flexing and bending the panel to seat onto the bin; engaging protrusions on the panel with gaps formed between shelves of the bin; seating the panel on outer edges of the shelves; closing the doors of the bin; and locking the doors using the locking member which extends through an opening of the panel.
[0014] One advantage of the present disclosure is that it provides a bin retaining panel that is installed onto a shelved bin for retaining articles within the bin.
[0015] Another advantage of the present disclosure is that it is easily installed and removed and is cost-effective.
[0016] Still another advantage of the present disclosure is that panel allows for easy installation of the panel on the bin by flexing or bending the panel.
[0017] A further advantage of the present disclosure is that it facilitates accurate horizontal placement of the panel by easy installation of the tabs on the panel into slots formed by the shelves.
[0018] Another advantage of the disclosure is bent ends which mate with door frames to retain the panel in position on the bin.
[0019] Another aspect of the disclosure is an opening which has a profile of a lock to accommodate a lock of the door.
[0020] Still other aspects of the disclosure will become apparent to those skilled in the art upon reading and understanding the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The disclosure may take physical form in certain components and arrangements of components, preferred embodiments of which will be described in detail in this specification and illustrated in the accompanying drawings which form a part hereof and wherein;
[0022] FIG. 1 is a top plan view of a bin retaining panel in accordance with one aspect of the disclosure;
[0023] FIG. 2 is a right side elevational view of the panel of FIG. 1 ;
[0024] FIG. 3 is a front elevational view of the panel of FIG. 1 ;
[0025] FIG. 4 is a perspective view of the panel of FIG. 1 ;
[0026] FIG. 5 is a top plan view of a bin retaining panel in accordance with another aspect of the disclosure;
[0027] FIG. 6 is a right side elevational view of the panel of FIG. 5 ;
[0028] FIG. 7 is a front elevational view of the panel of FIG. 5 ;
[0029] FIG. 8 is a perspective view of the panel of FIG. 5 ;
[0030] FIG. 9 is a perspective view of a two-piece bin retaining panel in accordance with another aspect of the disclosure;
[0031] FIG. 10 is a perspective view of a two-piece retaining panel assembly in accordance with still another aspect of the disclosure;
[0032] FIG. 11 is a perspective view of a bin retaining panel of FIG. 5 being lowered onto a storage bin in accordance with one aspect of the disclosure; and
[0033] FIG. 12 is a perspective view of the bin retaining panel of FIG. 5 in an installed position on a storage bin.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] Referring now to FIGS. 1-4 , a preferred embodiment of the present disclosure is shown. Bin retaining panel A has a generally flat planar wall 10 which has ends 12 , 14 , 16 , 18 forming a generally rectangular configuration. The bin retaining panel is fabricated from preferably a thin sheet of metal. Upper or first end 12 has a bent edge 20 which is bent at about 90 degrees with respect to the planar wall 10 . Edge 20 has two half sections 21 , 23 to accommodate and retain the ends of the doors in a closed configuration. Edge 20 also helps put pressure on the panel with the door resting on the panel and retain the panel in position. Edge 18 also helps apply pressure to the panel from the door resting on top of the panel. Sections 21 , 23 each have rounded edges but straight edges are also contemplated by the disclosure. A notch or gap 19 can be formed between walls 21 , 23 to accommodate ends or edges of two doors. Edge 20 extends upwardly (i.e., out of the page) as shown in FIG. 1 . Side ends 14 , 16 have a bent edge 22 , 24 which are bent downwardly or into the page as shown in FIGS. 2 and 3 . Edges 22 , 24 are bent at an acute angle with respect to wall 10 of about 45 degrees or so. Edges 22 , 24 have a series of tabs or protrusions 26 , 28 which are sized and configured to engage mating slots 138 formed in shelves of a bin. For example, notches 26 , 28 can have a rectangular or square shape but other configurations such as angled or rounded shapes are also contemplated by the disclosure. Protrusions 26 , 28 can have a substantially C-shaped or rounded or curved notch 29 formed therein for accommodating a shelf wall. Other shapes and configurations of notches or cut-outs are also contemplated by the disclosure. Protrusions 26 , 28 engage slots or openings 138 in the shelf wall and help align and maintain the protrusion of the panel.
[0035] Bottom end 18 has a straight edge portion 30 which is not bent with respect to planar wall 20 . Edge 30 is shown to have rounded or radiused corners 31 , 33 , but straight corners could be used as well. Positioned on the planar wall is a slot or opening 32 which is sized and configured to receive a correspondingly locking member for a door of the shipping container. Opening 32 can be placed centrally on panel in various positions on the planar wall as discussed. A plurality of holes 34 can also be formed on the panel for hanging the panel when not in use.
[0036] Referring now to FIGS. 5-8 , an alternate embodiment of the bin retaining panel B is shown. Panel 40 also has a generally flat planar wall 42 which is generally rectangular in configuration.
[0037] Planar wall 42 has ends 44 , 46 , 48 , 50 which form the rectangular conformation. Upper and lower ends 44 , 46 each has a bent edge or wall 52 , 54 which is bent upwardly (extending out of the page in FIG. 6 ) about 90 degrees with respect to wall 42 as shown in FIG. 6 . Walls 52 , 54 help retain and position doors on the cabinet in a closed configuration. The walls 52 , 54 also help retain the panel in position and apply pressure to the panel via the door resting on the panel.
[0038] Wall 52 includes two half sections 56 , 58 to accommodate the ends of the doors. A notch or gap 59 can be formed between wall sections 56 , 58 to accommodate the ends of the two doors. As shown in FIG. 8 , wall section 56 , 58 each has curved or rounded edges. However, straight or angled edges are also contemplated.
[0039] Side ends 48 , 50 each has a bent edge 60 , 62 which is bent downwardly or into the page as seen in FIGS. 6 and 7 . Edges 60 , 62 are bent at an acute angle with respect to wall 42 at about 45 degrees or so. Other angles are also contemplated by the disclosure. Edges 60 , 62 have a series of tabs or protrusions 64 , 66 (such as rectangular or square shape or any suitable shape) which are sized and configured to engage mating slots 138 formed by shelves in the bin. Protrusions 64 , 66 can have a C-shaped or rounded or curved slot 69 to accommodate a portion of the shelf. Positioned on the planar wall is a slot or opening 72 which is sized and configured to receive a correspondingly locking member for a door of the shipping container. A plurality of holes 73 on planar wall 42 can be used for hanging the panel when not in use.
[0040] Referring now to FIG. 9 , another alternate embodiment of the bin retaining panel assembly is shown. This embodiment has two half panels 80 , 82 each of which has planar walls 84 , 86 and upper and lower ends 88 , 90 , 92 , 94 which have bent edges 96 , 98 , 100 , 102 bent at about 90 degrees with respect to planar walls 84 , 86 . These bent edges help align the doors on the panel and apply pressure to the panel via the doors. A gap is formed between panels 80 , 82 to accommodate the two doors. Side ends 104 , 106 each has a bent edge 108 , 110 bent downwardly at about 45 degrees with respect to planar walls 84 , 86 . Edges 108 , 110 have a plurality of tabs or protrusions 112 which engage slots 138 formed by shelves of the storage bin for aligning the panel and retaining it in position. Tabs 112 can have a substantially rectangular or square shape and can have a round or curved slot or notch 115 formed therein. Inner ends 107 , 109 do not have bent edges.
[0041] Each of the planar walls can also have a cut-out or opening 111 , 113 to accommodate a lock member of the bin door. Also, the panels 80 , 82 can be configured to be used in a first orientation or a second orientation rotated 180 degrees with respect to the first orientation.
[0042] Referring to FIG. 10 , another alternate embodiment is shown. This embodiment is essentially the same as described for FIG. 9 , but additional bent edges 114 , 116 are formed on ends 118 , 120 of the panels 80 , 82 .
[0043] Each of the bent edges accommodate the door frames of the bin and puts additional pressure on the panel to stay in position by contacting the door frame. A gap is formed between the panels 80 , 82 to accommodate the two doors' edges.
[0044] Referring now to FIGS. 11 and 12 , installation of a bin retaining panel B (shown in FIGS. 5-8 ) onto a storage bin C is shown. Bin C has a plurality of side walls 122 , 124 , 126 , 128 and two hinged doors 130 , 132 which have a locking member assembly 134 . A plurality of shelves 136 are positioned within the bin. Bin panel B is lowered onto the end of the bin when the bin is tilted on its side. That is, shelves 136 are positioned vertically in this orientation or at about 90 degrees with respect to the panel B. Shelves 136 form a series of slots or openings 138 which matingly receive and engage bent tabs 64 , 66 formed on edges 60 , 62 of the panel. This helps align the panel and retain it in position on the bin.
[0045] Referring to FIG. 12 , the panel B can be flexed or bent sufficiently to engage the tabs 64 , 66 with slots 138 of the shelves. The panel then rests horizontally on or is positioned on outer edges 140 of the shelves 136 . The doors 130 , 132 are then closed wherein the bent edges 54 , 56 , 58 of the panel contact the edges of the doors to help retain the panel in position and allow the doors apply pressure to the panel. The doors are then locked and the locking member is received within opening 72 . The bin is then placed in a storage or shipping container and is shipped. The steps described for FIGS. 11 and 12 also apply to the panels shown in FIGS. 1-4 and FIGS. 9 and 10 .
[0046] When the bin arrives at the user destination, the doors are unlocked and removed, and the panel is removed by pulling on the cut-out or opening 72 on the panel. Alternatively, rings or cable retaining members 150 can be formed on each of the planar walls to accommodate cable ties, straps, zip ties, etc. to pull the panel out of engagement with the bin.
[0047] The exemplary embodiment has been described with reference to a preferred embodiment. Obviously, modifications and alterations will occur to others upon the reading and understanding of this specification. The specification is intended to include all such modifications and alterations insofar as they come within the scope of the appended claims or the equivalents thereof. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a resin-molded stator, a method of manufacturing the same, and a rotary machine using the same.
2. Description of the Prior Art
Conventional resin-molded stators and rotary machines using the same employ the structure where, as disclosed in Japanese Application Patent Laid-Open Publication No. 08-223866, Japanese Application Patent Laid-Open Publication No. 09-157440, and Japanese Application Patent Laid-Open Publication No. 10-51989, the stator coil wound around the plurality of slots or bumps in the stator core, and the stator coil at the end of the stator core are molded with resin and the molding resin and the end of the stator core that faces in the axial direction of the rotary machine are bonded. Also, an alternating-current (AC) power generator using brushes to supply power to the rotor is disclosed in Japanese Application Patent Laid-Open Publication No. 2000-125513.
The present inventors have found that the prior art practice poses the problem that when a stringent acceleration test simulating the operation mode in which the output of the rotary machine is to be increased from the level under its stopped status to the maximum achievable level within a short time is repeated several times, insulation breakdown occurs between the stator coils and the ground or between the different phases of the stator coils. It is considered that the insulation breakdown occurs as follows:
It has been examined why and how the insulation breakdown occurs between the stator coils and the ground or between the different phases of the stator coils when the operation mode in which the output of the rotary machine is to be increased from the level under its stopped status to the maximum achievable level within a short time is repeated several times. As a result, it has been found that when the output level is increased to its maximum within a short time, the stator coils are heated by the electrical resistance of the coil conductor and, depending on the particular conditions, the coil temperature increases to a maximum of about 250° C. At the same time, it has also been found that since the heat capacity of the stator core is high, increases in the temperature thereof retard with respect to the stator coils. Accordingly, the difference in temperature between the stator coils and the stator core often reaches 200° C. or more.
The thermal expansion coefficient of the copper used for the stator coils is 1.7×10 −5 1/° C., and the thermal expansion coefficient of the stator core in the direction that electromagnetic steel plates were laminated in the direction of the rotational axis of the stator core to form the core is about 1.3×10 −5 1/° C. In this way, the stator coils and the stator core differ in thermal expansion coefficient, and when a temperature difference exists between the stator coils and the stator core, the amount of thermal elongation also differs between both. The resin-molded stator may have the structure where one side of its coil end is constrained by being positioned between the stator core and the end face of the housing in the direction of its rotational axis in the rotary machine. The relative displacement Δ occurring between the stator coils and the stator core, at the coil end of a resin-molded stator having such structure, is represented by formula (1) below.
Δ={α c ×( Tc−Tr )−α f ×( Tf−Tr )}× L (1)
where: “αc” and “αf” are the thermal expansion coefficients of the stator coils and the stator core, respectively; “Tc” and “Tf” are the temperatures of the stator coils and stator core when the output of the rotary machine is increased to the maximum output level within a short time; “Tr” is the temperature at which the difference between the stator coils and the stator core in terms of thermal elongation is zero, and; “L” is the laminating thickness of the stator core.
For example, if the laminating diameter of the stator core in a resin-molded stator having the structure where one side of its coil end is constrained by being positioned between the end face of the housing and the stator core is 100 mm, when the temperature of the stator coils increases from 20° C. to 230° C. and the temperature of the stator core increases from 20° C. to 50° C., the relative displacement Δ occurring between the stator coils and stator core at the coil end can be calculated by assigning, to formula (1) shown above, an “αc” value of 1.7×10 −5 1/° C. as the thermal expansion coefficient of the stator coils, an “αf” value of 1.3×10 −5 1/° C. as the thermal expansion coefficient of the stator core, a “Tc” value of 230° C. as the temperature of the stator coils, a “Tf” value of 50° C. as the temperature of the stator core, a “Tr” value of 20° C. as the temperature at which the difference between the stator coils and the stator core in terms of thermal elongation is zero, and an “L” value of 100 mm as the laminating thickness of the stator core. As a result, it follows from the difference in thermal elongation that the relative displacement Δ occurring between the stator coils and stator core at the coil end is 0.35 mm.
The stress “σc” applied to the stator coil section when the space between the stator core and the stator coils is constrained so as not to cause relative displacement between both can be represented using the following formula (2) which assumes that all thermal strain is imposed on the stator coils:
σ c=Δ×Ec/L (2)
where “Δ” is the relative displacement between the stator coils and stator core at the coil end, “Ec” is the longitudinal elastic modulus of the stator coils, and “L” is the laminating thickness of the stator core.
If “Δ”, “Ec”, and “L” are 0.35 mm, 100 GPa, and 100 mm, respectively, the stress “σc” applied to the stator coils reaches 0.35 GPa.
The stator coils running through the stator slots and emerging at the coil end are split into sections wound clockwise and counterclockwise around the stator core according to phase and engage with other stator slots. Accordingly, the coils wound from a plurality of stator slots towards other stator slots are accommodated under a mutual contact status at the coil end section of the stator. In this case, if the stator core and the resin-molded section at the coil end are bonded, a thermal elongation difference reaching 0.35 mm occurs between the stator core and stator coils at the coil end, and at the same time, since the stator coils emerging at the coil end are wound in different directions for each phase, a phase shift occurs between the coils of different phases and is likely to damage the insulation around the conductors, resulting in insulation breakdown. The same also applies to concentrated-winding structure having coils wound at the protrusions of the stator core. That is to say, if the stator core and the resin-molded section at the coil end are bonded, the difference in thermal elongation between the conductors and the core due to abrupt increases in the temperature of the conductors causes the buckling thereof and is likely to damage the insulation, and resulting in insulation breakdown.
SUMMARY OF THE INVENTION
The object of the present invention is to provide
a resin-molded stator in which the stator coils wound around a plurality of slots and the stator coils at the end of the stator core are molded with resin in order for insulation breakdown between the stator coils and the ground or between the different phases of the stator coils to be prevented by repeating several times the operation mode in which the output level of a rotary machine employing the aforementioned resin-molded stator is to be increased from the level under a stopped status to the maximum level within a short time, a method of manufacturing the resin-molded stator outlined above, and a rotary machine using the same.
The present invention applies to a resin-molded stator comprising
a stator core,
stator coils wound around said stator core and provided with insulation, and
molding resin with which the stator core and said stator coils are molded,
wherein said resin-molded stator is characterized in that said molding resin has non-adhesive structure against at least one of the end faces of the stator core. The particles of aluminum oxide, magnesium oxide, silicon oxide, boron nitride, calcium carbonate, talc, or the like are added as an inorganic filler to the molding resin.
The resin-molded stator pertaining to the present invention is further characterized in that a non-adhesive film or separator for obtaining non-adhesion against said resin is formed as non-adhesive structure between said molding resin and at least one of said end faces of the stator core. Polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, and the like are used in bridged form as the non-adhesive film, and this film is not fusible with respect to the aforementioned mold. Or silicon is used as the separator.
In other words, in the present invention, the resin-molded stator where the stator coils provided with insulation are wound around the plurality of slots or protrusions provided in the axial direction of the stator core and the stator core, the stator coils around the slots or protrusions, and the stator coils at the stator core end, is characterized in that non-adhesive structure is provided between the molding resin and said end face of the stator core.
A rotary machine may need to be operated at its maximum output level at the same time the machine is started. When the rotary machine is actually placed in such operation, the temperature of its stator coils will increase to about 250° C. by the action of Joule heat. However, since the stator core has a large heat capacity, increases in the temperature of the stator core are retarded with respect to the stator coils by the thermal resistance of the electric insulating material located between the stator coils and the stator core, and for this reason, the temperature of the stator core often reaches only about 50° C., even when the temperature of the stator coils reaches 250° C. In the present invention, the differences in the amount of thermal elongation that result, at that time, from the thermal expansion coefficient of the stator core in the laminating direction of electromagnetic steel plates in the direction of the rotational axis of the stator core, from the difference in temperature between and the stator coils and the stator core, and from the difference in thermal expansion coefficient between both, are absorbed by providing non-adhesive structure between the molding resin and the end face of the stator core so as to prevent coil damage.
It is preferable that the above-mentioned molding resin should be made of the polyester-based resin containing an inorganic filler, that the inorganic filler should contain calcium carbonate and aluminum oxide, and that the above-mentioned non-adhesive film should be polytetrafluoroethylene resin.
The present invention also applies to a resin-molded stator manufacturing method characterized in that
it sequentially comprises a process in which stator coils provided with insulation are to be wound around a plurality of slots or protrusions formed in the axial direction of a stator core consisting of laminated electromagnetic steel plates, and a process in which the end face of said stator core is to be axially provided with a resin film or separator having the same shape as that of the vertical section of the stator core,
and further characterized in that said manufacturing method sequentially comprises a process in which, after the above-described process, the stator core around which said stator coils are wound is to be built into a housing, a process in which the aforementioned housing with the stator core built thereinto is to be preheated and then set in a preheated mold, and a molding process in which the stator core and the stator coils located at the above-mentioned slots or protrusions and at the end of the stator core are to be molded with resin by injecting the resin into the mold having the housing set therein.
In addition, in the present invention, by providing, between the housing of the rotary machine and the molding resin at the coil end where the stator coils were molded, insert structure in which the housing and the molding resin can be moved in the respective axial directions and cannot be moved about the respective axes, it is possible to suppress the vibrational displacement associated with operation that occurs between the stator coil at the stator slot portion and the stator coil at the resin-molded coil end portion, and hereby to prevent stator coil damage.
If the size (W) of a space formed in the axial direction of the rotary machine, between the coil end portion provided with resin molding by providing non-adhesive structure with respect to the end face of the stator core, is smaller than the value derived from the product of (A×T×Lc) [A is the thermal expansion coefficient of the stator coil conductor, T is the maximum temperature that the conductor reaches during the operation of the rotary machine, and Lc is the total axial length of the conductor that includes said coil end], when the temperature of the conductor increases, the coil end portion provided with non-adhesive structure with respect to the end face of the stator core will come into contact with the components mounted at the end plate and consequently the effect that should originally be obtainable by providing the non-adhesive structure will not be created. This problem, however, can be solved by setting the size (W) of the above-mentioned space to a value equal to, or greater than, the value derived from the above-mentioned value of (A×T×Lc).
The rotary machine pertaining to the present invention is characterized in that the rotary machine comprises a rear plate for covering the other side of said rotor, a brush assembly for supplying electric power via slip rings provided on the rotor, a rear bracket connected to said rear plate and intended for covering the brush assembly, a bearing which supports one end of the rotor and is provided in the housing, and a bearing which supports the other end of said rotor and is provided in the rear plate.
The rotary machine pertaining to the present invention is further characterized in that the rotary machine comprises an end plate for covering the other side of said rotor, a bearing which supports one end of said rotor and is provided in said housing, and a bearing which supports the other end of said rotor and is provided in said end plate.
It is preferable that the sections of the above-mentioned housing that are to accommodate the resin-molded stator and one side of the rotor built into the stator should be formed into a single unit, that a space for absorbing the thermal expansion of the stator coils in their axial direction should be provided at the side having the non-adhesive structure described above, that the above-mentioned should be provided between the molding resin of the stator coils and the rear plate or between the molding resin of the stator coils and the end plate, and that there should be insert structure in which the axial length of the housing at its inner circumferential side should be greater than the axial length of the resin-molded stator and the housing and the molding resin separated from the stator core by the non-adhesive structure provided at the core end of the stator can be moved in the respective axial directions and cannot be moved about the respective axes.
According to the present invention, it is possible not only to provide a highly reliable resin-molded stator not suffering insulation breakdown between the different phases of the stator coils even when the operation mode for increasing the output of a rotary machine from the level under its stopped status to the maximum achievable level within a short time is repeated, but also to provide a rotary machine that uses such a stator.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of the resin-molded stator pertaining to the present invention;
FIG. 2 is a cross-sectional view of the section A–A′ in FIG. 1 ;
FIG. 3 is a partial cross-sectional view of the rotary machine pertaining to the present invention;
FIG. 4 is a partial side view of a conventional rotary machine;
FIG. 5 is a partial cross-sectional view of the rotary machine which employs concentrated winding in the resin-molded stator pertaining to the present invention.
FIG. 6 is a partial cross-sectional view of a brushless rotary machine using the resin-molded stator which employs concentrated winding of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiment 1
FIG. 1 is a cross-sectional view of the resin-molded stator showing an embodiment of the present invention. FIG. 2 is a cross-sectional view of the section A–A′ in FIG. 1 , and FIG. 3 is a cross-sectional view of the section B–B′ in FIG. 2 . The steps taken to manufacture this resin-molded stator are described below. A slot provided in a stator core 1 consisting of laminated electromagnetic steel plates is covered with a liner 8 which is made of a polyamideimides non-woven fabric, and then stator coils 2 each consisting of a conductor provided with insulation are wound around the stator core 1 . After this, the stator core 1 around which the stator coils 2 have been wound is built into a housing 4 which has a bearing installation recess 3 at the end of the housing. Of the two surfaces vertical to the axis of the stator core 2 , only the surface located at the opposite side to the bearing installation recess 3 in the housing 4 when the stator core 1 is to be built into the housing is coated with a polytetrafluoroethylene resin film which has been pre-processed into the same shape as that of the electromagnetic steel plates of the stator core 1 , and the coated surface mentioned above functions as a non-adhesive treatment section 5 to prevent bonding between the stator core 1 and the molding resin 7 to be later added.
The polytetrafluoroethylene resin film is bridged, does not fuse during molding, and functions as non-adhesive structure. Although, in the present embodiment, the resin film is formed as a non-adhesive treatment section 5 between molding resin and stator core at one side, this film can also be provided at both sides. In the present embodiment, as shown in FIG. 1 , since the resin film also functions as a mold for resin-molding the housing 4 located at one side, this film gives non-adhesiveness to one side. In the housing 4 , a plurality of injection-molding gate positions 10 functioning as resin injection ports for resin-molding the housing 4 are provided circumferentially on the side thereof so as to ensure equal injection of the resin, and these gates are filled with the molding resin. Molds are provided at the opposite side to the resin injection ports and at the inner circumferential side.
The housing 4 is also provided with an agency 6 through which the coolant for cooling the rotary machine is to be passed. Next, the housing 4 into which the stator core 1 with the stator coils 2 wound around it, is preheated to 100° C. and then set in a mold which has been heated to 150° C. beforehand. After this, the polyester-based molding resin that has been filled with the powder of calcium carbonate and aluminum oxide is injection-molded at a pressure of 4 MPa, and hereby, the stator coil 2 inside the slot of the stator core 1 and the stator coil 2 at the coil end emerging from the stator core 1 are molded. As shown in FIG. 2 , a recess 9 for preventing the rotational vibration of the coil end portion is provided in the housing 4 .
Two types of resin are available as examples of the polyester-based molding resin mentioned above: (1) molding resin created by mixing resin, calcium carbonate powder, and alumina powder at the weight rate of 1:1:1, with the resin consisting of 100 weight parts of maleic acid-containing unsaturated polyester and 40 weight parts of styrene monomer, and (2) molding resin created by mixing resin, calcium carbonate powder, and alumina powder at the weight rate of 1:1:1, with the resin consisting of 100 weight parts of isophthalic acid-containing unsaturated polyester and 40 weight parts of styrene monomer.
FIG. 4 is a cross-sectional view of the rotary machine pertaining to the present invention. A rotor 19 and a shaft 21 having slip rings 20 built thereinto are attached to the resin-molded stator shown in FIG. 1 . After this, rear plates 23 which have a diode 22 and the like, are attached, then a brush assembly 24 and a regulator 25 are installed, and a rear bracket 26 is installed. The axial length (W) of a coil end space 28 provided between the resin-molded section at the coil end portion and the rear plate 23 is set to a value equal to, or greater than, the value derived from the product of (A×T×Lc), where A is the thermal expansion coefficient of the stator coil conductor, T is the maximum temperature that the conductor reaches during the operation of the rotary machine, and Lc is the total axial length of the conductor that includes said coil end.
A stringent acceleration test for increasing the output of the thus-manufactured rotary machine from the level under its stopped status to the maximum achievable level within a short time has been repeated five times, with the result that no abnormality has been observed. Although an example of a rotary machine with slip rings, a brush assembly, and a diode, has been shown in the present embodiment, it is obvious that the embodiment can be similarly applied to a rotary machine not equipped with these components.
COMPARATIVE EXAMPLE 1
FIG. 5 is a cross-sectional view of the resin-molded stator shown as a comparative example against the present invention. The steps taken to manufacture this resin-molded stator are described below. A slot provided in a stator core 1 consisting of laminated electromagnetic steel plates is covered with a liner which is made of a polyamideimides non-woven fabric, and then stator coils 2 each consisting of a conductor provided with insulation are wound around the stator core 1 . After this, the stator core 1 around which the stator coils 2 have been wound is built into a housing 4 which has a bearing installation recess 3 at the end of the housing. Or the housing 4 is provided with an agency 6 through which the coolant for cooling the rotary machine. Next, the housing 4 into which the stator core 1 with the stator coils 2 wound around it, is preheated to 100° C. and then set in a mold which has been heated to 150° C. beforehand. After this, the polyester-based molding resin that has been filled with the powder of calcium carbonate and aluminum oxide is injection-molded at a pressure of 4 MPa, and hereby, the stator coil 2 inside the slot of the stator core 1 and the stator coil 2 at the coil end emerging from the stator core 1 are molded.
A rotor 19 and a shaft 21 having slip rings 20 built thereinto are attached to the resin-molded stator. After this, rear plates 23 which have a diode 22 and the like, are attached, then a brush assembly 24 and a regulator 25 are installed, and a rear bracket 26 is installed.
A stringent acceleration test for increasing the output of the thus-manufactured rotary machine from the level under its stopped status to the maximum achievable level within a short time has been repeated five times, with the result that insulation breakdown has occurred between phases.
Embodiment 2
FIG. 6 is a partial cross-sectional view of a brushless rotary machine using the resin-molded stator which employs concentrated winding in the present invention. The steps taken to manufacture this rotary machine are described below. A protrusion provided on a stator core 1 consisting of laminated electromagnetic steel plates is covered with a liner which is made of a polyamideimides non-woven fabric, and then stator coils 2 each consisting of a conductor provided with insulation are wound around the stator core 1 . After this, the stator core 1 around which the stator coils 2 have been wound is built into a housing 4 . Of the two surfaces vertical to the axis of the stator core 2 , only the surface located at the opposite side to the bearing installation recess in the housing 4 when the stator core 1 is to be built into the housing is coated with a polytetrafluoroethylene resin film which has been pre-processed into the same shape as that of the electromagnetic steel plates of the stator core 1 , and the coated surface mentioned above functions as a non-adhesive treatment section 5 to prevent bonding between the stator core 1 and the molding resin 7 to be later added. The housing 4 is also provided with an agency 6 through which the coolant for cooling the rotary machine is to be passed.
Next, the housing 4 into which the stator core 1 with the stator coils 2 wound around it, is preheated to 100° C. and then set in a mold which has been heated to 150° C. beforehand. After this, a pressure of 4 MPa is applied to the polyester-based molding resin that has been filled with the powder of calcium carbonate and aluminum oxide. Thereby, similarly to embodiment 1 described above, in the housing 4 , a plurality of injection-molding gate positions 10 functioning as resin injection ports for resin-molding the housing 4 are provided circumferentially on the side thereof so as to ensure equal injection of the resin, and these gates are filled with the molding resin to provide injection-molding, with the result that the stator coil 2 inside the slot of the stator core 1 and the stator coil 2 at the coil end emerging from the stator core 1 are molded. A recess 9 for preventing the rotational vibration of the coil end portion is also provided in the housing 4 .
As shown in FIG. 6 , a shaft 21 into which a rotor 19 has been built is attached to the resin-molded stator. After this, an end plate 27 having a bearing mounted therein is installed. The axial length (W) of a coil end space 28 provided between the resin-molded section at the coil end portion and the rear plate 27 is set to a value equal to, or greater than, the value derived from the product of (A×T×Lc), where A is the thermal expansion coefficient of the stator coil conductor, T is the maximum temperature that the conductor reaches during the operation of the rotary machine, and Lc is the total axial length of the conductor that includes said coil end.
A stringent acceleration test for increasing the output of the thus-manufactured rotary machine from the level under its stopped status to the maximum achievable level within a short time has been repeated five times, with the result that no abnormality has been observed. | 4y
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BACKGROUND OF THE INVENTION
This invention relates generally to an apparatus for guiding and holding rechargeable batteries in a battery charger and more particularly to a battery charger apparatus having a battery pocket configuration and guides such that batteries of different charge capacities and sizes may be properly positioned and supported while being charged.
It is a statement of the obvious to state that rechargeable batteries are intended to be recharged. Devices which perform this recharging function are quite well known.
Portable electronic equipment traditionally employs rechargeable batteries and many varied designs of battery chargers have been developed to recharge the batteries. In many instances, the electrochemical cells which comprise the battery are housed or contained in an enclosure which provides protection and support for the electrochemical cells. For example, a detachable battery housing containing several electrochemical cells is employed in a portable cellular radiotelephone (model number F09HGD8453AA) manufactured by Motorola, Inc. and having an appearance similar to that shown in U.S. patent application Ser. No. 255,696, "Portable Telephone, Telephone Handset, or Similar Article", filed on Oct. 11, 1988 on behalf of Soren et al. and assigned to the assignee of the present invention. The appearance of the battery housing is similar to that shown in U.S. patent application Ser. No. 179,006, "Battery Housing For A Portable Telephone Or Similar Article", filed on Apr. 8, 1988 on behalf of Soren et al. and assigned to the assignee of the present invention.
Conventionally, battery chargers utilize a charging pocket or pockets to generally hold batteries. In some instances, spacer ribs are located within the charging pocket to prevent binding between the battery housing and the housing of the charger. These chargers, however, are designed to accommodate a single size battery housing. Batteries are likely to have different sizes and charge capacities. Such variations can cause the battery charger associated with the batteries to become overly complex to accommodate the batteries.
SUMMARY OF THE INVENTION
Accordingly, the present invention solves the problem of accommodating different battery sizes without undue complexity.
It is one object of the present invention to position a battery housing within a battery charger.
It is another object of the present invention to employ a locating channel and a sloped battery charger housing to correctly position batteries of varying sizes within the battery charger.
It is a further object of the present invention to utilize the housing of the battery charger to position batteries of varying sizes and maintain such position with the force of gravity.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an isometric view of the battery charger of the present invention and illustrating a battery to be charged;
FIG. 2 is a single point perspective view of a small size battery housing which may be advantageously used by the present invention;
FIG. 3 is a single point perspective view of a large size battery housing which may be advantageously used by the present invention.
FIG. 4 is a cross-sectional view of a battery charger housing which employs the present invention.
FIG. 5 is a cross-sectional detail view of the housing of a battery charger employing the present invention and showing a battery positioned against the battery charger housing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention disclosed herein is of a battery charger with a housing having the capability of guiding and holding the housing of rechargeable batteries such that the battery housing may be properly positioned and supported while the batteries are being charged. Such an apparatus is shown in the isometric view of FIG. 1. Here, a battery charger (101) has two recesses (103 and 105) into either of which a battery (107) may be placed. Although two recesses are shown, the present invention may be employed in battery housings having one or more such recesses. A battery charger having a similar appearance has been disclosed in U.S. patent application Ser. No. 264,304, "Battery Charger or Similar Article", filed on Oct. 27, 1988 on behalf of Soren et al. and assigned to the assignee of the present invention. The operation of the electrical portion of a similar battery charger has been disclosed in U.S. patent application Ser. No. 361,534, "Multiple Battery, Multiple Rate Battery Charger", filed on June 5, 1989 on behalf of Johnson et al. and assigned to the assignee of the present invention.
User operation of the battery charger of FIG. 1 is accomplished by placing a battery (107) in one of the recesses (103 or 105) by elevating the battery (107) over the top surface and somewhat to the rear of the battery charger housing (101) and sliding the battery down and toward the front of the battery charger housing (101) such that the battery (107) slides against the interior side surfaces (visible as side surface (109)). Once the battery (107) enters a recess, for example recess 103, it will engage rib members disposed on opposite side surfaces of the battery housing (101). One such rib member (111) is visible in the view of FIG. 1. Another rib member is located on the interior side wall surface directly opposite the side wall surface (109). This rib member is not visible in the view of FIG. 1. Rib member (111) engages a slot (113) in the battery housing (107) to direct the battery toward charging contacts (115) and enable the proper charging of the electrochemical cells of the battery. It is an important feature of the present invention that the side surfaces of the battery charger housing (101) and the rib members (for example, rib member (111) of the battery charger housing (101) cooperate in directing the battery against the battery charging contacts. The battery is held in the proper orientation against the charging contacts (115) by the rib members and the unique battery charger shape directing the weight of the battery with a minimum of complexity of battery charger design.
Referring now to FIGS. 2 and 3, which are single point perspective views of a small and large size battery housing respectively, it can be observed that the shape of the battery housings are essentially trapezoidal prisms. The bottom surfaces (201) of the battery housings shown in FIGS. 2 and 3 are surfaces which mate against the housing of the aforementioned cellular portable radio telephone during operation. A sloping surface (202) as shown in FIGS. 2 and 3 have electrical contacts (203) mounted thereon which are oriented so that the contacts (203) make electrical connection with charging contacts (115) of the battery charger (101) when the battery is placed in the battery charger. The charging contacts (115) of the battery charger housing (101) are located on the interior bottom surface (117) of the housing. The interior bottom surface (117) is an essentially flat surface parallel with the bottom of the battery charger housing.
The sides (205, 207) of the battery housing of FIGS. 2 and 3 slope inward at an angle 0 relative to a line perpendicular to surface (201). In the preferred embodiment, the angle 0 equals an angle of 10°. The difference in size between the small size battery of FIG. 2 and the large size battery of FIG. 3 is primarily a difference in thickness from the surface (201) to the top surface (209) in FIGS. 2 and 3. In the preferred embodiment, the battery housing thickness, t 1 , of FIG. 2 is approximately 10 millimeters while the thickness, t 2 , of the large size battery of FIG. 3 is approximately 20 millimeters. The battery charger of the present invention is so arranged that the contacts (203) of both the large size and the small size batteries are positioned in electrical contact with the charging contacts (115) of the battery charger when either battery is placed in the battery charger housing.
A vertical plane cross-sectional view of the battery charger of the present invention is shown in FIG. 4. In this view the battery rib member (111) of recess (103) and the battery rib member (401) of recess (105) may be seen. Rib members (111 and 401) are oriented at an angle φ relative to the plane of the bottom surface (117) of battery charger (101). In the preferred embodiment, φ=30° and the rib member is approximately 29 millimeters long and 1.35 millimeters thick. The rib members, when engaged with the slots (113) of the battery housing (107), produce an alignment in the surface of the battery housing (107) carrying the contacts (203) parallel to the base of the battery charger (101) such that the battery charger contacts (115) make contact with the battery electrical contacts 203 regardless of whether the battery is the small or large size battery. The circuit board containing electronics of the battery charger is disposed beneath the battery charger base surface (403). This circuit board (405) is contained within the battery charger housing (101) and supports the electric contact members of the battery charger contacts (115 and 407). Power is supplied to the electronic circuitry on circuit board (405) by way of power jack (409).
A cross-sectional detail view of the side wall having interior surface (109) and exterior surface (505) is shown in FIG. 5. Although the cross-section illustrates a solid wall for ease of understanding, it is within the scope of the present invention to utilize a hollow wall construction. A cross-section of the small size battery (107) is shown contacting the interior side wall (109). Likewise, a cross-section of the large size battery is shown in dotted line and illustrates the position of the large size battery housing when contacting the interior side wall (109). It is to be noted that the surface (201) of both batteries is positioned on the same plane. The side wall itself is configured having a tapered cross-sectional shape with the largest area to the rear of the battery charger housing (101) and narrowing toward the front of battery charger (101). Thus an acute angle 0 is formed by the interior wall surface (109) of the battery charger pocket or recess (103, 105) and the exterior surface (505) of the battery charger housing (101). In the preferred embodiment, the interior wall surface (109) and the exterior surface (505) of the battery charger housing (101) are essentially planar wall surfaces and the imaginary planes formed by the walls, when extended, intersect in the angle 0 with the vertex of angle 0 toward the front of the battery charger housing (101). Since both the battery charger housing (101) interior walls and the sides of the battery housing (107) have the same value of angle 0, the battery is guided by the interior side walls as it is inserted into the charging pocket of the battery charger. As the battery is slid further down in the charging pocket, the slots (113) in the battery housing (107) engage the rib members (111) of the battery charger housing (101) to accurately position the battery and its charging contacts (203) relative to the charging contacts (115) of the battery charger.
The side wall of the battery charger housing extends to the front of the battery charger. At the front, the side wall curves inward to begin enclosing the charging pocket (103). The side wall terminates in a protrusion (507) which is used to captivate one of the surfaces of a portable cellular radiotelephone such as that previously mentioned (F09HGD8453AA) and similar to that shown in U.S. patent application Ser. No. 255,696, "Portable Telephone, Telephone Handset, or Similar Article" filed on behalf of Soren et al. on Oct. 11, 1988 and assigned to the assignee of the present invention. The use of protrusion (507) and a similar protrusion on the opposite side wall will hold the aforementioned cellular portable in the correct position so that an attached battery (having a conformal shape) will be charged while attached to the cellular portable. | 4y
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TECHNICAL FIELD
This disclosure relates to isolation detection circuitry for battery packs used in automotive vehicles.
BACKGROUND
High voltage may be required to increase the output of a power supply for driving an electric or hybrid-electric vehicle: output is proportional to the product of voltage and current. The output voltage of a power supply for driving an electric or hybrid-electric vehicle, for example, may be 200 V or more. These power supplies may not be grounded. Hence, leakage currents associated with these power supplies may be undesirable. A leakage current may exist when a resistance between a power supply and chassis is present.
SUMMARY
A vehicle may include first and second battery packs spaced away from each other within the vehicle, and a leakage detection circuit. The leakage detection circuit may include a first precision resistor disposed within the first battery pack and electrically connected with chassis ground, and a switching element and first series limiting resistor disposed within the second battery pack and electrically connected in series with the first precision resistor. The leakage detection circuit responds to leakage currents within the second battery pack.
A vehicle may include a plurality of battery packs positioned at different locations within the vehicle. One of the packs may include a plurality of resistors each being electrically connected with chassis ground and a different one of the packs, and sense circuitry configured to detect voltage across each of the resistors. The vehicle may further include at least one controller configured to determine presence of leakage currents associated with other of the packs based on the detected voltages.
A power system for a vehicle may include a first battery pack including a plurality of battery cells and a switching element electrically connected with the battery cells. The power system may also include a second battery pack spaced away from the first battery pack and including a resistor electrically connected in series with the switching element, and sense circuitry configured to detect voltage across the resistor indicative of leakage current associated with the first battery pack.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a battery pack and associated isolation detection circuitry for an automotive vehicle.
FIG. 2 is a block diagram of an alternatively powered vehicle having a distributed set of battery packs.
FIG. 3 is a schematic diagram of the distributed set of battery packs of FIG. 2 and associated isolation detection circuitry.
DETAILED DESCRIPTION
As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.
Referring to FIG. 1 , a battery pack 10 for an automotive vehicle (not shown) may include a plurality of battery cells 12 a - 12 n (electrically connected in series), switches 14 , 16 (e.g., contactors, etc.), isolation detection circuitry 18 , and sense circuitry 19 disposed within a housing 20 . The switches 14 , 16 may be closed to electrically connect the battery cells 12 a - 12 n to terminals 22 , 24 associated with a high voltage bus. As known in the art, an electric machine configured to generate motive power for the vehicle may be electrically connected with such a high voltage bus. Hence, the battery cells 12 a - 12 n may provide electrical current for consumption by the electric machine.
The isolation detection circuitry 18 includes a switch 26 , a (series limiting) resistor 28 , and a (precision) resistor 30 electrically connected in series between chassis ground and a node defined by the electrical connection between the battery cell 12 a and the switch 14 (referred to herein as node A). The isolation detection circuitry 18 also includes a switch 32 , a (series limiting) resistor 34 , and a (precision) resistor 36 electrically connected in series between chassis ground and a node defined by the electrical connection between the battery cell 12 n and the switch 16 (referred to herein as node B). The voltage across each of the resistors 30 , 36 is proportional to the current flowing through them.
A current leak at node A may be detected by opening the switch 26 , closing the switches 14 , 16 , 32 , and measuring the voltage across the resistor 36 . (That is, an Ohmic leak is intentionally created between node B and the chassis, and the resulting voltage across the resistor 36 is measured via the sense circuitry 19 . Ohm's law may then be used to determine the current flowing through the resistor 36 , which is equal to the leakage current associate with node A.) Similarly, a current leak at node B may be detected by opening the switch 32 , closing the switches 14 , 15 , 26 and measuring the voltage across the resistor 30 . Other techniques and architectures may also be used to detect current leaks in a single battery pack.
Referring to FIG. 2 , an alternatively powered vehicle 38 (e.g., a battery electric vehicle, a hybrid-electric vehicle, a plug-in hybrid-electric vehicle, etc.) may include an electric machine 40 (e.g., motor, motor/generator, etc.), a transmission 42 (e.g., power-split, mechanical, etc.), and wheels 44 . The electric machine 40 is arranged to mechanically drive the transmission 42 (as indicated by thick line), and the transmission 42 is arranged to mechanically drive the wheels 44 (as indicated by thick line). If the vehicle 38 is a hybrid-type vehicle, it may of course include an engine (not shown) arranged to also selectively mechanically drive the transmission 42 . Other arrangements are also possible.
The vehicle 38 may also include battery packs 46 , 48 (or more battery packs in certain arrangements) and controllers 50 , 51 disposed within the battery packs 46 , 48 respectively. The battery packs 46 , 48 are electrically connected together (as indicated by thin line) in series, and the battery pack 46 is electrically connected with the electric machine 40 (as indicated by thin line). Hence, the battery packs 46 , 48 may provide electrical current for consumption by the electric machine 40 . In the example of FIG. 2 , the battery packs 46 , 48 are distributed throughout the vehicle 38 . That is, the battery pack 46 is positioned in a certain location within the vehicle 38 (e.g., inside the vehicle's cabin) and the battery pack 48 is positioned in a different location within the vehicle 38 (e.g., underneath the vehicle's cabin). Such battery pack arrangements may be used to better package battery cells within the vehicle 38 . In other examples, the controllers 50 , 51 may be separate from the battery packs 46 , 48 ; the battery packs 46 , 48 may be electrically connected together in parallel; and/or the battery packs 46 , 48 may each be electrically connected with the electric machine 40 . Other arrangements are also contemplated.
The battery pack 46 is in communication with/under the control of the controller 50 . The battery pack 48 is in communication with/under the control of the controller 51 . The controllers 50 , 51 are in communication with each other (as indicated dashed line).
Current leaks may occur within either or both of the battery packs 46 , 48 . Hence, it may be desirable to detect the presence of such leaks. Merely providing isolation detection circuitry similar to that described with respect to FIG. 1 in each of the battery packs 46 , 48 , however, may not be practical. It may be cost prohibitive, for example, to provide sense circuitry similar to that described with respect to FIG. 1 in each of the battery packs 46 , 48 . Moreover, it may be difficult to coordinate isolation checks of battery packs so arranged. As discussed in more detail below, the battery packs 46 , 48 may include isolation detection circuitry that enables the detection of current leaks with centrally located sense circuitry.
Referring to FIG. 3 , the battery pack 46 may include the controller 50 , a plurality of battery cells 52 a - 52 n (electrically connected in series), switch 54 (e.g., a contactor, etc.), isolation detection circuitry 56 , and sense circuitry 58 disposed within a housing 60 . The switch 54 may be closed to electrically connect the battery cells to a terminal 61 , which is electrically connected with a high voltage bus (not shown). The electric machine 40 ( FIG. 2 ) is also electrically connected with this high voltage bus.
The isolation detection circuitry 56 may include a switch 62 , a (series limiting) resistor 64 , and a (precision) resistor 66 electrically connected in series between chassis ground and a node defined by the electrical connection between the battery cell 52 a and the switch 54 (referred to herein as node X). The isolation detection circuitry 56 may also include a switch 68 , a (series limiting) resistor 70 , and a (precision) resistor 72 electrically connected in series between chassis ground and a node defined by the electrical connection between the battery cell 52 n and a battery cell 74 a (referred to herein as node Y). The voltage across each of the resistors 66 , 72 is proportional to the current flowing through them.
The battery pack 48 may include the controller 51 , a plurality of battery cells 74 a - 74 n (electrically connected in series) and switch 76 disposed within a housing 78 . The switch 76 may be closed to electrically connect the battery cells to a terminal 80 , which is electrically connected with the high voltage bus described above and the electric machine 40 ( FIG. 2 ).
Isolation detection circuitry 82 is distributed between the battery packs 46 , 48 . That is in the example of FIG. 3 , the isolation detection circuitry 82 may include a switch 84 and a (series limiting) resistor 86 disposed within the housing 78 , and a (series limiting) resistor 88 and a (precision) resistor 90 disposed within the housing 60 . Hence, the centrally located sense circuitry 58 , which in this example happens to be associated with the battery pack 46 , may be used to detect the voltage across any of the resistors 66 , 72 , 90 by way of an analog to digital converter whose reference node is connected with chassis ground. A multiplexer circuit as commonly found in such converters may then be used to select among the voltages associated with the resistors 66 , 72 , 90 .
The switch 84 and resistor 86 are electrically connected in series between the resistor 88 and a node defined by the electrical connection between the battery cell 74 n and the switch 76 (referred to herein as node Z). The resistors 88 , 90 are electrically connected in series between chassis ground and the resistor 86 . The resistors 86 , 88 prevent excessive current from flowing through them when their associated wires are shorted. Either of the resistors 86 , 88 , in other examples, may be omitted. Such omission, however, may result in thermal or other issues.
The controller 50 may include, inter alia, the isolation detection circuitry 56 , the sense circuitry 58 , and the resistors 88 , 90 . The controller 51 may include, inter alia, the switch 84 and the resistor 86 . Other configurations are also contemplated.
This architecture may be used with any number of battery packs. That is, a central battery pack may include centrally located sense circuitry and (precision) resistors electrically connected with chassis ground for each of a set of satellite battery packs. Each of the (precision) resistors may then be electrically connected with a switch located within a corresponding satellite battery pack via one or more (series limiting) resistors located within the satellite battery pack and/or the central battery pack similar to that described with reference to FIG. 3 . Other arrangements are also possible.
The controllers 50 , 51 may operate to determine whether the isolation detection circuits 56 , 82 and sense circuitry 58 are in proper working order: (a) the switch 68 may be opened, the switches 62 , 84 may be closed, and the voltages across the resistors 66 , 90 and the voltage from node X to node Z may be measured. This information may then be evaluated according to (1) and (2):
V pack-est=(( V 66/ R 66)*( R 66+ R 64))+(( V 90/ R 90)*( R 90+( R 88+ R 86))) (1)
| V pack-est− VXZ|≦α (2)
where VXZ is the voltage difference between the nodes X and Z, V 66 is the voltage across the resistor 66 , V 90 is the voltage across the resistor 90 , R 64 , R 66 , R 86 and R 88 are the resistances of the resistors 64 , 66 , 86 and 88 respectively, and α is a predetermined value; (b) the switch 84 may be opened, the switches 62 , 68 may be closed, and the voltages across the resistors 66 , 72 and the voltage from node X to node Y may be measured. This information may then be evaluated according to (3) and (4):
V 2pack-est=(( V 66/ R 66)*( R 66+ R 64))+(( V 72/ R 72)*( R 72+ R 70)) (3)
| V 2pack-est− VXY|≦β (4)
where VXY is the voltage difference between the nodes X and Y, V 66 is the voltage across the resistor 66 , V 72 is the voltage across the resistor 72 , R 64 , R 66 , R 70 and R 72 are the resistances of the resistors 64 , 66 , 70 and 72 respectively, and β is a predetermined value; and (c) the switch 62 may be opened, the switches 68 , 84 may be closed, and the voltages across the resistors 72 , 90 and the voltage from node Y to node Z may be measured. This information may then be evaluated according to (5) and (6):
V 3pack-est=(( V 90/ R 90)*( R 90+ R 88))+(( V 72/ R 72)*( R 72+ R 70)) (5)
| V 3pack-est− VYZ|≦γ (6)
where VYZ is the voltage difference between the nodes Y and Z, V 90 is the voltage across the resistor 90 , V 72 is the voltage across the resistor 72 , R 70 , R 72 , R 88 and R 90 are the resistances of the resistors 70 , 72 , 88 and 90 respectively, and γ is a predetermined value.
If (2), (4) and (6) are true, the isolation detection circuits 56 , 82 and sense circuitry 58 are in proper working order. If any of (2), (4) and (6) is not true, the isolation detection circuits 56 , 82 or sense circuitry 58 may not be in proper working order.
The controllers 50 , 51 may perform a leakage check from node X to chassis: the switch 84 may be closed, the switches 62 , 68 may be opened, and the voltage across the resistor 90 , V 90 , and the voltage from node X to node Z, VXZ, may be measured. The system leakage resistance, Rleakx, may then be expressed as a function of VXZ and V 90 :
VXZ *( R 90/( R 90+ R 88+ R 86+ R leak x ))= V 90 (7)
where R 86 , R 88 and R 90 are the known resistances of the resistors 86 , 88 , 90 respectively. (7) may be rearranged to solve for Rleakx using known techniques.
The controllers 50 , 51 may perform a leakage check from node Z to chassis: the switch 62 may be closed, the switches 68 , 84 may be opened, and the voltage across the resistor 66 , V 66 , and the voltage from node X to node Z, VXZ, may be measured. The system leakage resistance, Rleakz, may then be expressed as a function of VXZ and V 66 :
VXZ*[R 66/( R 66+ R 64+ R leak z )]= V 66 (8)
where R 64 and R 66 are the known resistances of the resistors 64 , 66 respectively. (8) may be rearranged to solve for Rleakz using known techniques.
While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention. | 4y
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BACKGROUND OF INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to integrated power conversion systems and methods for use in a variety of applications, such as battery-powered (electric) vehicle applications, fuel cell vehicle applications, and hybrid electric vehicle applications.
[0003] 2. Description of the Related Art
[0004] Traditionally, the power conversion system of a battery-powered electric vehicle (EV), a fuel cell vehicle, and a hybrid electric vehicle (HEV) has included a plurality of separate, discrete components and assemblies. Among these components and assemblies are a traction inverter module (TIM) and a DC/DC converter.
[0005] The TIM, also called the electric power inverter, is operable for converting the raw DC current generated by a high-voltage fuel cell or high-voltage storage device (e.g., battery, flywheel, or ultracapacitor) into an AC current capable of powering an electric motor, such as a traction motor or a field-oriented induction motor. This power is converted for driving and controlling the motor, i.e., for generating torque. The motor, in combination with a transaxle, converts the electrical energy into mechanical energy which turns the wheels of the vehicle.
[0006] The DC/DC converter utilizes pulse-width modulation (PWM) to step the voltage associated with the vehicle's high-voltage battery or fuel cell down to that which the alternator of an internal combustion engine (ICE)-powered vehicle would typically generate (13.5-14V). The DC/DC converter, which may be unidirectional or bi-directional, may be used, for example, to charge a 12V auxiliary battery, which is typically separated from the high-voltage battery or fuel cell.
[0007] The DC/DC converter may also be used to transfer power from the auxiliary battery to the high-voltage battery or fuel cell to, for example, start the vehicle. In general, the DC/DC converter is operable for matching a plurality of voltages.
[0008] Traditionally, the TIM and the DC/DC converter are separate, discrete assemblies, including a 3-phase assembly for the TIM and an H-bridge assembly for the DC/DC converter. The TIM and the DC/DC converter have typically utilized separate, discrete high-voltage DC bus capacitors, DC bus bars, and high-voltage transistors. This configuration has several important limitations. High-voltage cables must be utilized to connect the TIM and the DC/DC converter. Separate, discrete thermal management systems must be utilized to cool the TIM and the DC/DC converter. The result is a complex, bulky, costly configuration. Thus, what is needed are systems and methods for integrating the TIM and the DC/DC converter.
BRIEF SUMMARY OF INVENTION
[0009] The present invention provides systems and methods for integrating the TIM and the DC/DC converter. Specifically, the present invention provides systems and methods for integrating the high-voltage DC bus capacitors, DC bus bars, and high-voltage transistors of the TIM and the DC/DC converter. Advantageously, the systems and methods of the present invention result in a simple, compact, and inexpensive TIM DC/DC converter assembly, utilizing common high-voltage cables and a common thermal management system.
[0010] In one embodiment, an integrated power conversion system for use in an electric vehicle including an electric motor, a primary high-voltage energy source, and an auxiliary energy source includes a traction inverter module operable to convert a DC current generated by the primary high-voltage energy source into an AC current capable of powering the electric motor, and a DC/DC converter operable to step-down a voltage of the high-voltage energy source and/or step-up a voltage of the auxiliary energy source, wherein the traction inverter module and the DC/DC converter share one or more common components, such as a high-voltage DC bus capacitor, a common DC bus bar, and a common high-voltage transistor.
[0011] In another embodiment, an integrated power conversion method for use in an electric vehicle including an electric motor, a high-voltage energy source, and an auxiliary energy source includes providing a traction inverter module operable for converting a DC current generated by the high-voltage energy source into an AC current capable of powering the electric motor, providing a DC/DC converter operable for stepping-down a voltage of the high-voltage energy source or stepping-up a voltage of the auxiliary energy source, and disposing a plurality of common components within the traction inverter module and the DC/DC converter. The plurality of common components may include a common high-voltage DC bus capacitor, a common DC bus bar, and a common high-voltage transistor.
[0012] In a further embodiment, an integrated power conversion system for use in a power generating system including an electric motor, a high-voltage energy source, and an auxiliary energy source includes a traction inverter module operable to convert a DC current generated by the high-voltage energy source into an AC current capable of powering the electric motor, wherein the traction inverter module comprises a first circuit, and a DC/DC converter operable to step-down a voltage of the high-voltage energy source or step-up a voltage of the auxiliary energy source, wherein the traction inverter module and the DC/DC converter share a common high-voltage DC bus capacitor, a common DC bus bar, and a common high-voltage transistor.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0013] [0013]FIG. 1 is a circuit diagram of a system including separate, discrete TIM and DC/DC converter assemblies.
[0014] [0014]FIG. 2 is a circuit diagram of one embodiment of a system including integrated TIM and DC/DC converter assemblies.
[0015] [0015]FIG. 3 is a circuit diagram of another embodiment of a system including integrated TIM and DC/DC converter assemblies, specifically including a 55 kW TIM inverter and a 3 kW boost 2 kW buck bi-directional DC/DC converter.
[0016] [0016]FIG. 4 is a circuit diagram of a further embodiment of a system including integrated TIM and DC/DC converter assemblies, specifically including a 55 kW TIM inverter and a 2 kW buck converter for 12V loads.
[0017] [0017]FIG. 5 is a circuit diagram of a further embodiment of a system including integrated TIM and DC/DC converter assemblies, specifically including a 55 kW TIM inverter and a 45-55 kW bi-directional DC/DC converter.
DETAILED DESCRIPTION OF THE INVENTION
[0018] Referring to FIG. 1, as described above, the power conversion system 10 of EVs, fuel cell vehicles, and HEVs typically includes a separate, discrete TIM assembly 12 and DC/DC converter assembly 14 . The TIM 12 inverts the high-voltage DC bus voltage to an AC voltage suitable for powering the motor 16 , such as a 3-phase AC voltage. This power is inverted for driving and controlling the motor 16 , i.e., for generating torque. The motor 16 , in combination with the transaxle, converts the electrical energy into mechanical energy which turns the wheels of the vehicle. The DC/DC converter 14 uses PWM to step the voltage associated with the vehicle's high-voltage energy source 18 , such as a battery, fuel cell, ultracapacitor, flywheel, or superconducting energy storage device down to that which the alternator of an ICE-powered vehicle would typically generate (13.5-14V). The DC/DC converter 14 , which may be unidirectional or bi-directional, may be used to charge an auxiliary energy source 20 such as a 12V auxiliary battery, which is typically separated from the high-voltage energy source 18 . The DC/DC converter 14 may also be used to transfer power from the auxiliary energy source 20 to the high-voltage energy source 18 to, for example, start the vehicle. In general, the DC/DC converter 14 is operable for matching a plurality of voltages.
[0019] The TIM 12 and the DC/DC converter 14 typically comprise separate, discrete assemblies, including a 3-phase assembly for the TIM 12 and an H-bridge assembly for the DC/DC converter 14 . The TIM 12 and the DC/DC converter 14 may also utilize separate, discrete high-voltage DC bus capacitors 22 and DC bus bars 24 . In this configuration, high-voltage cables must be utilized to connect the TIM 12 and the DC/DC converter 14 . Separate, discrete thermal management systems must be utilized to cool the TIM 12 and the DC/DC 14 converter. The result is a complex, bulky, costly configuration.
[0020] Referring to FIG. 2, in one embodiment, a system 30 including an integrated TIM 12 (FIG. 1) and DC/DC converter 14 (FIG. 1) includes two integrated assemblies: a high-voltage assembly 32 , including the TIM 12 and the high-voltage stage of the DC/DC converter 14 , and a low-voltage assembly 34 , including the low-voltage stage of the DC/DC converter 14 and a filter. The high-voltage assembly 32 is operatively connected to the low-voltage assembly 34 by a high-frequency transformer 36 . Specifically, the method may include removing the high-voltage power transistors from the DC/DC converter 14 and integrating them with the TIM's transistor module. This configuration allows the TIM 12 and the DC/DC converter 14 to share a high-voltage DC bus capacitor 38 and to utilize a simplified DC bus bar 40 . The integrated system 30 also includes the motor 16 , the high-voltage energy source 18 , and the auxiliary energy source 20 , while the high-voltage energy source 18 will typically take the form of a battery or fuel cell stack and the auxiliary energy source 20 will typically take the form of a battery, these energy sources may take the form of any or a combination of batteries, fuel cell stacks, ultracapacitors, flywheels, and/or superconducting magnetic storage devices.
[0021] In this configuration, high-voltage cables utilized to connect the TIM 12 and the DC/DC converter 14 may be eliminated and a common thermal management system may be utilized to cool the high-voltage power stage of the TIM 12 and the DC/DC converter 14 . The result is a simple, compact, inexpensive configuration.
[0022] Referring to FIG. 3, in another embodiment, a TIM 12 , such as a 55 kW TIM inverter, may be integrated with a DC/DC converter 14 , such as a 3 kW boost 2 kW buck bi-directional DC/DC converter. The integrated system 50 includes a high-voltage bridge module 52 for the TIM 12 and the DC/DC converter 14 and a low-voltage bridge module 54 for the DC/DC converter 14 . The high-voltage bridge module 52 is operatively connected to the low-voltage bridge module 54 by a high-frequency transformer 36 . The integrated system 50 may also include the motor 16 , a 250-420V high-voltage energy source 18 , and the auxiliary energy source 20 . The integrated system 50 may further include a plurality of switches 56 , such as insulated gate bipolar transistors (IGBTs) 58 or MOSFETs. In this configuration, high-voltage cables utilized to connect the TIM 12 and the DC/DC converter 14 may be eliminated and a common thermal management system may be utilized to cool the high-voltage power stage of the TIM 12 and the DC/DC converter 14 . Again, the result is a simple, compact, inexpensive configuration.
[0023] Referring to FIG. 4, in a further embodiment, a TIM 12 , such as a 55 kW TIM inverter, may be integrated with a DC/DC converter 14 , such as a 2 kW buck converter for 12V loads. The integrated system 60 includes a high-voltage bridge module 52 for the TIM 12 and the DC/DC converter 14 and a low-voltage rectifier 62 for the DC/DC converter 14 . The high-voltage bridge module 52 is operatively connected to the low-voltage rectifier 62 by a high-frequency transformer 36 . The integrated system 60 may also include the motor 16 , the 250-420V high-voltage energy source 18 , and the 12V auxiliary energy source 20 . The integrated system 60 may further include a plurality of switches 56 such as IGBTs 58 or MOSFETs. In this configuration, high-voltage cables utilized to connect the TIM 12 and the DC/DC converter 14 may be eliminated and a common thermal management system may be utilized to cool the TIM 12 and the DC/DC converter 14 . Again, the result is a simple, compact, inexpensive configuration.
[0024] Referring to FIG. 5, in a further embodiment, a TIM 12 , such as a 55 kW TIM inverter, may be integrated with a DC/DC converter 14 , such as a 45-55 kW bi-directional DC/DC converter. The integrated system 70 includes a high-voltage bridge module 52 for the TIM 12 and the DC/DC converter 14 . The integrated system 70 may also include the motor 16 , the 250-420V high-voltage energy source 18 , and a 150-190V auxiliary energy source 20 . The integrated system 70 may further include a plurality of IGBTs 58 or MOSFETs. In this configuration, high-voltage cables utilized to connect the TIM 12 and the DC/DC converter 14 may be eliminated and a common thermal management system may be utilized to cool the TIM 12 and the DC/DC converter 14 . Again, the result is a simple, compact, inexpensive configuration.
[0025] All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, including, but not limited to U.S. Serial No. 60/319,116 filed Feb. 20, 2002, are incorporated herein by reference, in their entirety.
[0026] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims. | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority from, and is a continuation application of, U.S. patent application Ser. No. 14/826,128, filed on Aug. 13, 2015, which claims the benefit of U.S. Provisional Application Ser. No. 62/037,607, filed on Aug. 15, 2014. The applications are hereby incorporated by reference herein in their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention is related to measuring the distance between two objects based on a time of flight of a probe signal sent between the objects. In particular, the present invention is related to measuring the distance between two objects using a positioning system, such as the Global Positioning System (GPS).
[0004] 2. Discussion of the Related Art
[0005] The “time of flight” of a signal is often used to determine the position or the time of the objects. The “time of flight” is a time-offset measured between the time a probe signal is sent and the time the probe signal is received. The distance between the objects is the product of the time of flight and the propagation speed of the probe signal (e.g., the speed of light, in the case of a GPS signal). In the GPS system, the time of flight is referred to as a “pseudo-range measurement.” In many systems, the time of flight may be used in additional calculations. For example, in the GPS system, multiple pseudo-range measurements are used to determine a 3-dimensional position of an object relative to the earth. The clock offset may also be calculated to further refine the accuracy in the calculated location. Detailed descriptions of various aspects of the GPS system may be found, for example, in “Global Position System: Signals, Measurement and Performance” (“Enge”) by Pratap Misra and Per Enge, and its cited references.
SUMMARY
[0006] According to one embodiment of the present invention, a position-determining apparatus, such as a GPS receiver, determines the position of the mobile device based on the time of flight of a transmitted probe signal using a method in which sections of the received signal is classified into two or more categories and accumulated according to categories before being used to compute the convolutions familiar in the context of a matched filter.
[0007] Using the method of the present invention to compute the convolutions, and optionally applying additional time-saving techniques described herein, the present invention allows a position determination to be achieved using a number of arithmetic operations that is significantly reduced from that required in prior art methods to compute the convolutions. The reduced number of arithmetic operations can reduce significantly the power consumption required of a device carrying out a method of the present invention, and thereby realizing a significant advantage.
[0008] The present invention is better understood upon consideration of the detailed description below in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a block diagram of GPS receiver 100 , in accordance with one embodiment of the present invention.
[0010] FIG. 2 is a block diagram showing an implementation of offset calculation channel 200 , which is representative of any of channels 103 - 1 , 103 - 2 , . . . 103 - c of FIG. 1 , according to one embodiment of the present invention.
[0011] FIG. 3 is a flow chart that illustrates a method of operation for an offset calculation channel (e.g., offset calculation channel 200 of FIG. 2 ), in accordance with one embodiment of the present invention.
[0012] FIG. 4 is a flow chart that illustrates the operations in fine offset estimation step 302 of FIG. 3 , in accordance with one embodiment of the present invention.
[0013] FIG. 5 shows a binary probe signal (i.e., having values expressed by either the +1 level or −1 level), in accordance with one embodiment of the present invention.
[0014] FIG. 6 illustrates dividing demodulated signal 604 into sections, in accordance with one embodiment of the present invention.
[0015] FIG. 7 shows the waveforms of probe signals 702 , 703 , 705 , and 706 , and center probe signal 704 , before, between and after section boundaries 701 , in accordance of the present invention.
[0016] FIG. 8 illustrates masked probe signal s m (n), according to one embodiment of the present invention.
[0017] FIG. 9 illustrates a categorization scheme for center probe signal 903 , in which the 2-bit value representing the category of each section is assigned based on whether or not transitions exist in the previous and the following chips, in accordance with one embodiment of the present invention.
[0018] FIG. 10 illustrates a categorization scheme in which the category of a section is encoded by a 3-bit value representing, respectively, whether or not the previous, current and next section includes a signal transition, according to one embodiment of the present invention.
[0019] FIG. 11 shows how, using the probability threshold scheme, the probability distribution of relative offset x evolves in time for category 1 sections under single-T categorization and masking (i.e., sections in which a transition occurs in the corresponding probe signal), in accordance with the present invention.
[0020] FIG. 12 is a flow chart illustrating method 1200 for operating an accumulator, according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] In the following detailed description, a probe signal transmitted between two objects may refer to a probe signal sent from one object and received by the other object or, alternatively, a signal sent by one object, reflected from the second object and then received by the first object. The present invention is applicable to the GPS or, more generally, the Global Navigation Satellite System (GNSS), which includes GPS, GLONASS, Galileo, Beidou, and other similar systems. In fact, the present invention is applicable not only to GNSS/GPS systems, but also in any time-offset measurement systems. For example, the present invention is applicable to measuring a time of fight of a radar probe signal that is sent from a radar antenna, reflected by the target object and then received by the radar antenna. As another example, the present invention is also applicable to determining a time of flight of a signal that is transmitted from a local sender to a local receiver to make a local position measurement. The time-of-flight technique can be applied to signal synchronization in communication systems. In this detailed description, a GPS receiver is used to illustrate the present invention. However, the present invention is not limited to application in a GPS receiver, but also in the applications mentioned above, as well as other applications.
[0022] FIG. 1 is a block diagram of GPS receiver 100 , in accordance with one embodiment of the present invention. As shown in FIG. 1 , signals of multiple GPS satellites are received by antenna 101 . These signals are typically amplified, demodulated and down-converted to an intermediate frequency (IF). Each signal may also be digitized by the RF front end 102 for processing in the digital domain. The resulting signal is then processed by one or more offset calculation channels, 103 - 1 , 103 - 2 , . . . 103 - c, each of which determines if the received signal includes a signal transmitted from a corresponding GPS satellite. For each GPS satellite signal identified, an offset or time of flight between that GPS satellite and GPS receiver 100 is calculated. CPU 104 further processes the offsets determined from the offset calculation channels 103 - 1 , 103 - 2 , . . . 103 - c to calculate receiver 100 's position and time. CPU 104 also controls offset calculation channels, 103 - 1 , 103 - 2 , . . . 103 - c. Details of offset calculation channels, 103 - 1 , 103 - 2 , . . . 103 - c and their control are provided below. In FIG. 1 , CPU 104 generally refers to both the CPU circuit itself and any memory, storage (e.g., RAM, ROM, FLASH memory, and hard disk drives) or other components necessary for supporting CPU operations.
[0023] FIG. 2 is a block diagram showing an implementation of offset calculation channel 200 , which is representative of any of channels 103 - 1 , 103 - 2 , . . . 103 - c of FIG. 1 , according o one embodiment of the present invention. As shown in FIG. 2 , block 201 represents providing digitalized in-phase and quadrature signals (i.e., I and Q signals) generated from RF front end 102 . The I and Q digitized quadrature signals are fed into channel-specific demodulator 202 . Channel-specific demodulator 202 , which receives a variable frequency signal from numerical oscillator (NCO) 203 , removes any remaining frequency modulation effects caused by, for example, the Doppler effect, receiver movement, local clock drift and any other effects. Each channel includes a channel-specific NCO and a channel-specific demodulator, represented by NCO 203 and channel-specific demodulator 202 described above. The demodulated I and Q signals are then processed in offset estimator 204 . CPU 205 controls NCO 203 , channel-specific demodulator 202 and offset estimator 204 . CPU 205 may be a stand-alone computational circuit, or may be implemented by CPU 104 , which is the overall system control circuit shown in FIG. 1 .
[0024] FIG. 3 is a flow chart that illustrates a method of operation for an offset calculation channel (e.g., offset calculation channel 200 of FIG. 2 ), in accordance with one embodiment of the present invention. As shown in FIG. 3 , step 301 performs a coarse estimation, also commonly known as “signal acquisition” in many GPS/GNSS systems. Coarse estimation reduces the search ranges of the offset and the frequency modulation in preparation for a fine estimation, which is represented in FIG. 2 by step 302 . For example, a coarse estimation or signal acquisition in a GPS system may provide a position accuracy of about 0.5 chip (each chip is a time unit that is about 1 μs long) and a Doppler frequency estimation accuracy of between 100 Hz to 500 Hz. Coarse offset estimation can be assisted by reference to other information, such as a location estimate from a cell phone tower. A system that uses such assistance information is called an Assisted GPS (AGPS) system. Structures and operations of AGPS are discussed, for example, in Enge. Coarse estimation step 301 may also provide an estimate of the signal-to-noise ratio (SNR) in the received signal, an offset accuracy (or “offset error”) and frequency accuracy (or “frequency error”).
[0025] Step 302 provides a fine estimation, which estimates the offset and the frequency modulation each to a higher resolution. For example, in one embodiment of the present invention, a fine estimation searches over an offset between −0.5 chip to 0.5 chip, and a frequency modulation between −250 Hz to 250 Hz. Due to various reasons, either one or both of coarse estimation step 301 and fine estimation step 302 may not always succeed. At step 303 , if an estimation step is not successful, coarse estimation step 301 is repeated. After a successful fine estimation step, the offset calculation channel may enter into a wait or idle step for a predetermined time (i.e., step 304 ), before repeating fine estimation step 302 . The wait time reduces power consumption in GPS receiver 100 .
[0026] FIG. 4 is a flow chart that illustrates the operations in fine estimation step 302 of FIG. 3 , in accordance with one embodiment of the present invention. Generally, the fine estimation step keeps and updates a set of statistical states based on data samples of the received signal collected and the time passed. In one embodiment, these statistical states are related to the probability distribution of the offset. (Conversely, the probability distribution of the offset may be derived from these statistical states). In some embodiments, the probability distribution of the offset can be used as the statistical states directly. For example, in one embodiment, the statistical states are represented by quantities that are proportional to the logarithms of the probability distribution. (Such a representation allows multiplications of probabilities to be performed as additions of the logarithms of the probabilities).
[0027] As shown in FIG. 4 , at step 401 , a prior estimation of probability distribution P 0 (x) of offset x is obtained. In one embodiment, probability distribution P 0 (x) may be obtained from coarse estimation step 301 . For example, in one embodiment, a distribution P(x) of offset x is obtained from a signal acquisition in a GPS receiver, with P(x) spanning the search range
[0000]
x
∈
[
-
t
c
2
,
t
c
2
]
,
[0000] where t c is the chip time. The probability that offset x is outside this search range in this embodiment is believed small. Initial distribution estimation P 0 (x) may be obtained from side information, such as assistance data from a cell tower. The initial search range can be the range covered by the communication range of the cell tower. In some embodiments, initial distribution P 0 (x) may be a rough estimate, while in other embodiments, a simple uniform distribution can be used, when only the range of offset x is estimated during signal acquisition. In other embodiments, when a standard deviation is estimated for offset x during signal acquisition, a Gaussian distribution may be used.
[0028] In step 402 , data samples of the received probe signal are taken, which are used to update the probability distribution P(x) at step 402 . As probability distribution P(x) corresponds to the statistical states in this embodiment, an update to probability distribution P(x) at step 403 updates the statistical states. At step 404 , an updated estimation for offset x is then performed based on the updated probability distribution P(x). A successfully update for offset x is output at step 405 . Alternatively, if the calculate value for offset x requires refinement to meet a predetermined accuracy requirement, additional data samples of the received probe signals are taken by returning to step 402 . Otherwise, i.e., if offset x cannot be estimated within the current search range, a failure signal is output at step 408 . In that case, a new coarse estimate is performed by returning to coarse estimation step 301 , for example, as illustrated above in conjunction with FIG. 3 . At step 406 , upon a successful estimate of offset x, the estimator may wait or idle at step 406 for a predetermined time period to save power. The predetermined time period may be specified by the user. Probability distribution P(x)—and therefore correspondingly, the statistical states also—is updated at step 407 , after a specified elapsed time at step 406 . The offset can be estimated by calculating the expected value of offset x from probability distribution P(x). The variance of the estimation for offset x can also be obtained from the probability distribution. The operations for updating probability distributions and for performing data sampling may depend on the characteristics of the probe signal, its transmission, propagation, reception and processing.
[0029] In one embodiment, a binary probe signal alternates between a +1 level and a −1 level, as illustrated in FIG. 5 . As shown in FIG. 5 , the probe signal may transition or “jump” from the +1 level to the −1 level, or from the −1 level to the +1 level. GPS C/A signal and GNSS BOC signals are examples of binary signals. The probe signal remains at each state for at least a chip before the next transition. In GPS/GNSS, each satellite is assigned a special code sequence, which is encoded in the transmitted signal by the +1 and −1 signal levels and periodically repeated. The code sequence spans 1023 chips in GPS C/A. The transmitted probe signal may be further modulated, such as by a predetermined carrier signal of a predetermined frequency (e.g., a carrier frequency at about 1.575 GHz for GPS C/A).
[0030] In one embodiment, the received signal is sampled at intervals each having a duration t s which is a fraction of chip time t c :
[0000]
t
s
=
t
c
M
(
1
)
[0000] where M is an integer. In some embodiments, one can also choose M to be close to an integer, or a fraction, and achieve the same or similar advantages of the present invention. The signal may distort along the way of processing and transmission. Typically, the signal passes through a transmission filter, a modulator, a transmission antenna, the communication channel (e.g., free space), a reception antenna, a receiver filter, and a demodulator. The distortion may exhibit itself as an actual longer transition time than its nominal time, resulting in a slope or other artifacts. In one embodiment, M is chosen so that, even in the distorted signal, each transition completes in in less than duration t s . In one embodiment, samples of the demodulated signal (at IF) from only I or Q (i.e., in-phase or quadrature, respectively) channels are used. When the demodulated signal has close to zero phase, only I channel is required. In some embodiments, both in-phase and quadrature samples are taken. When only one of the I and Q channels is used, the samples are taken at relative time 0, t s , 2t s , 3t s , . . . , nt s , . . . and are denoted y(0), y(1), y(2), . . . , y(n), . . . . Alternatively, when both I and Q channels are sampled, the output signal y(n) is complex-valued:
[0000] y ( n )= yI ( n )+ j yQ ( n ) (2)
[0000] where j=√{square root over (−1)}, and yI(n) and yQ(n) represent, respectively, the in-phase and quadrature samples of the demodulated signal at time n.
[0031] Let signal s(n) represent a replica of the probe signal with a time offset at the center of the estimated search range (“center probe signal”). Signal s(n) can be interpreted as the expected undistorted form of the received signal based on prior knowledge (e.g., knowledge from the coarse estimation step 301 , described above). Further, let x denote the estimated offset between the noise-less demodulated signal and center probe signal s(n) (“relative offset”). The pseudo-range and the location of the receiver may be derived based on relative offset x. Choosing signal s(n) to have a relative offset at the center of the search range is merely for mathematical convenience. The offset of signal s(n) may be set at any other position within the search range (e.g., at the beginning of the search range).
[0032] The probability distribution may be updated according to Bayes' Rule:
[0000]
P
(
x
y
)
=
P
(
x
)
P
(
y
x
)
P
(
y
)
(
3
)
[0000] where P(x|y) is an estimation of the probability distribution of offset x after samples y of the demodulated signal are observed. Since P(y) is independent of x, P(v) is a normalization factor that need not be explicitly calculated. Taking the logarithm on both sides of equation (3), one obtains the log likelihood equation.
[0000] L ( x|y )= L ( x )+ L ( y|x )− L ( y ) (4)
[0000] where L denotes the log likelihood operation, or in general,
[0000] L ( P )=log( P ) (5)
[0000] Let y(n) be modeled as the sum of a noise-less received signal z(n) and an additive noise ε(n):
[0000] y ( n )= γz ( n )+ε( n ) (6)
[0000] where γ is the gain of the communication channel and ε(n) is assumed to have a Gaussian distribution. Signal z(n) may be assumed to be a shifted version of signal s(n) discussed above. (Empirically, based on analysis of the transitions of the received signal, this assumption is good for most cases.) That is:
[0000] z ( n )= s ( n−x ) (7)
[0000] where x denotes the relative offset. Thus, z(n) is also referred to in this detailed description as “the shifted signal.”
[0033] Without loss of generality, one may set an expect magnitude of the signal to be 1 (i.e. E[|s(n)|]=1). The signal-to-noise ratio (SNR) of signal y(n) is provided by:
[0000]
SNR
=
γ
2
σ
2
(
8
)
[0000] where σ is the standard deviation of the Gaussian distribution of additive noise ε(n). Thus,
[0000]
L
(
y
x
)
=
∑
n
=
0
N
-
1
L
(
y
(
n
)
s
(
n
-
x
)
)
(
9
)
[0034] As additive noise ε(n) is presumed Gaussian:
[0000]
L
(
y
(
n
)
s
(
n
-
x
)
=
β
0
-
1
2
σ
2
(
y
(
n
)
-
γ
s
(
n
-
x
)
)
2
(
10
)
[0000] where β 0 is a constant. Accordingly,
[0000]
∑
n
=
0
N
-
1
L
(
y
(
n
)
s
(
n
-
x
)
=
N
β
0
-
1
2
σ
2
(
∑
n
=
0
N
-
1
y
2
(
n
)
-
γ
2
∑
n
=
0
N
-
1
s
2
(
n
-
x
)
+
2
γ
∑
n
=
0
N
-
1
y
(
n
)
s
(
n
-
x
)
(
11
)
[0000] Assuming that the y 2 (n) and the s 2 (n) terms are constant, equation (11) can be rewritten as:
[0000]
∑
n
=
0
N
-
1
L
(
y
(
n
)
s
(
n
-
x
)
=
β
1
+
γ
σ
2
∑
n
=
0
N
-
1
y
(
n
)
s
(
n
-
x
)
(
12
)
[0000] where β 1 is a normalization factor. Define the quantity L′(y|x) (“un-normalized log likelihood of signal y(n) given offset x”) as:
[0000]
L
′
(
y
x
)
=
∑
n
=
0
N
-
1
L
′
(
y
(
n
)
s
(
n
-
x
)
=
γ
σ
2
∑
n
=
0
N
-
1
y
(
n
)
s
(
n
-
x
)
(
13
)
[0035] Since the convolution operation over two signals v(n) and s(n s given by:
[0000]
conv
(
u
,
v
,
x
)
=
∑
n
=
0
N
-
1
v
(
n
)
u
(
n
-
x
)
(
14
)
[0000] Equation (13) can be rewritten as:
[0000]
L
′
(
y
x
)
=
∑
n
=
0
N
-
1
L
′
(
y
(
n
)
s
(
n
-
x
)
=
γ
σ
2
Conv
(
y
,
s
,
x
)
(
15
)
[0000] Recalling from equation (8) above, the factor
[0000]
γ
σ
2
[0000] can be obtained from the SNR and σ:
[0000]
γ
σ
2
=
SNR
σ
(
16
)
[0000] Normalizing the probability distribution ensures that the sum of all probabilities equals 1. Define the un-normalized probability distribution:
[0000] P ′( x|y )= P ( x ) e L′(y|x) (17)
[0000] Therefore, P(x|y) is given by:
[0000]
P
(
x
y
)
=
P
′
(
x
y
)
∑
x
P
′
(
x
y
)
(
18
)
[0036] Here, signal y(n) is a sequence of real numbers. Therefore, this result is directly applicable to the I or Q samples. In one embodiment, when the signal can be reliably demodulated, one need only use one of the two channels (e.g., the I channel alone). However, if signal y(n) is a sequence of complex numbers, i.e., when both I and Q channels are sampled (e.g., the signal of equation 2), the magnitudes of the convolution conv(y, s, x) and the gain γ are used:
[0000]
L
′
(
y
x
)
=
∑
n
=
0
N
-
1
L
′
(
y
(
n
)
s
(
n
-
x
)
=
γ
σ
2
Conv
(
y
,
s
,
x
)
and
(
19
)
γ
σ
2
=
SNR
σ
(
20
)
[0037] If M samples are taken of each of N c chips, the total number N of samples is N c M. Using a straight-forward implementation of the convolution, with the search range of offset x given as N cx chips, the total number C t of accumulate-multiply steps required to calculate conv(y,s,x) is:
[0000] C t =M 2 N c N cx (21)
[0038] In one embodiment, the number of accumulate-multiply steps required may be reduced significantly by dividing the probe signal into multiple sections and categorizing each section into one of a set of categories, and processing each section according to the assigned category. The categorization step may be performed in a pre-processing of the probe signal.
[0039] At run time, the samples of the demodulated signal are assigned to sections, guided by the center probe signal (i.e., signal s(n) described above). Each section is categorized to the same category as the corresponding section of center prone signal s(n). The samples of the demodulated signal are then accumulated in a set of accumulators A(k,m) based on category (k) and the sample index offset (m). The values in the accumulators are then used to calculate a convolution for each offset x in the search range.
[0040] Under the categorization scheme, each section of a given category in any shifted probe signal of relative offset x within search range R x is indistinguishable from any other section of the same probe signal assigned to the same category. Search range R x is referred to as the “allowed range”, or the “allowed offset range.” A signal that can be categorized to a finite number of categories is referred to as a “section-categorizable” signal. Binary signals are always section-categorizable.
[0041] FIG. 6 illustrates dividing samples of demodulated signal 604 into sections, in accordance with one embodiment of the present invention. FIG. 6 also shows center probe signal 603 . Section boundaries 601 are each set at the mid-point of a corresponding chip in probe signal 603 . Each section lasts one chip time (t c ). As shown in FIG. 6 , each section is categorized according to the waveform of probe signal 603 within the section. For example, the neighboring sections 602 are categorized to categories ‘0’ and ‘1’. The categories of the remainder sections are similarly labeled. In the example of FIG. 6 , category k of each section may be any one of four categories: (a) k=0, when all signal values within the section equal to the +1 level; (b) k=1, when the signal values within the section transition once from the +1 level to the −1 level; (c) k=2, when all signal values within the section equal the −1 level; and (d) k=3, when the signal values within the section transitions from the +1 level to the −1 level.
[0042] In FIG. 6 , samples in a section of demodulated signal 604 are accumulated in an accumulator corresponding to the category of the assigned section and each sample's sample offset value. Note that the GPS C/A code is a periodic signal that repeats itself after every ms, and modulated on another signal (“information bits”). The information bits each have a period of about 20 ms.
[0043] FIG. 7 shows the waveforms of shifted probe signals 702 , 703 , 705 and 706 , and center probe signal 704 , before, between and after section boundaries 701 , in accordance of the present invention. Shifted probe signals 702 , 703 , 705 and 706 are obtained by offsetting the center probe signal 704 by relative offsets −½, −¼, ¼, and ½ chips, respectively (i.e., within the offset range of [−t c /2, t c /2]). In FIG. 7 , shifted probe signals 702 , 703 , 705 and 706 are also labeled S(n+2), S(n+1), S(n−1) and S(n−2), respectively. Center probe signal 704 is labeled S(n). As the signal values of center probe signal 704 transition only once from the +1 level to the −1 level between section boundaries 701 , the section is assigned category k=1, according to the categorization scheme described above. In FIG. 7 , a sampling rate of 4 samples per chip time may be used (i.e., ¼ chip between samples). Since center probe signal s(n) does not have a transition within a half-chip time outside of section boundaries 701 , in each shifted probe signal, all sections that are categorized to the same category k=1 have the same waveform within their respective section boundaries. That is, all sections of shifted probe signals 702 , 702 , 703 and 705 that are categorized to k=1 have their respective waveforms between section boundaries the same as those shown within section boundaries 701 . FIG. 7 thus illustrate “single-T categorization,” as the offset range is about one chip-time long.
[0044] Categorization may be used to reduce the number of arithmetic operations needed for calculating the convolution of each relative offset x. Formally, the convolution between the received signal and a shifted probe signal of relative offset x is given by:
[0000] Conv( y,s,x )=Σ n=0 N−1 y ( n ) s ( n−x )=Σ c C−1 Σ m=0 m−1 y ( cM+m ) s ( c,m−x ) (22)
[0000] where c denotes a section index, C denotes the number of sections within the convolution period, m denotes a sample index for the m-th sample within a section, s(c, m−x) denotes the signal value for the m-th sample in section c of shifted probe signal s(n−x), x being the relative offset, and y(cM+m) denotes the m-th sample in section c of the demodulated signal.
[0045] Let K be the total number of categories to which a section can be categorized. As discussed above, within each category k, the signal value s(c, m−x) is the same for all c<C, relative offset x being within allowed range R x . Thus, signal value s(c, m−x) in a section categorized to category k may be denoted s(k, m−x). Accordingly:
[0000]
Conv
(
y
,
s
,
x
)
=
∑
c
C
-
1
∑
m
=
0
M
-
1
y
(
cM
+
m
)
s
(
c
,
m
-
x
)
=
∑
k
=
0
K
-
1
∑
m
=
0
M
-
1
s
(
k
,
m
-
x
)
∑
c
∈
k
y
(
cM
+
m
)
(
23
)
[0000] where c∈k denotes section c that is categorized to category k. The accumulation of the samples of the demodulated signal in section c, i.e., Σ c∈k y(cM+in), may be performed using a set of accumulators. Let:
[0000] A ( k,m )=Σ c∈k y ( cM+m ) (24)
[0000] denote the accumulated value in the accumulator for accumulating samples of sections categorized to category k with section sample index m. Then, K×M accumulators are needed, one for each k and each sample offset index. FIG. 12 is a flow chart illustrating method 1200 for operating an accumulator at run time, according to one embodiment of the resent invention. As shown in FIG. 12 , at step 1201 , the beginning of a section is identified. At step 1202 , the section category k is determined or looked-up from a previously calculated table. Then, the M accumulators for category k are identified. By iteratively performing steps 1204 - 1208 , the sample values y(cM), y(cM+1), . . . y(c(2M−1)) are each added to a corresponding accumulator. When all sample values in the section are accumulated, at step 1208 , the process is repeated for the next section, until the sample values of all sections of the demodulated signal needed for the current set of convolutions have been accumulated (step 1209 ). Thus, if each convolution involves N samples of the demodulated signal, the total number of accumulate operations equal N−MN c (note that there is no multiplication performed for the portion of Equation 23):
[0000] C a =MN c (25)
[0000] At step 1210 , for each relative offset x, the convolution Conv(y, s, x) is calculated using the values in the accumulators:
[0000] Conv( y,s,x )=Σ k=0 K−1 Σ m=0 m−1 s ( k,m−x ) A ( k,m )=Σ k=0 K−1 conv( s ( k ), A ( k ), x ) (26)
[0000] Equation 26 shows that each convolution of length N is transformed into the sum of K convolutions, each of M samples and MN cx offsets. In general, Equation 26 requires:
[0000] C sum =KM 2 N cx (27)
[0000] accumulate-multiply operations and
[0000] C sa =KMN cx (28)
[0000] additions. Accordingly, under the method of FIG. 12 , the total number of arithmetic operations required for all relative offsets is much reduced:
[0000] C total =C a +C sam +C sa ≅MN c +KM 2 N cx (29)
[0046] There are numerous ways to implement the accumulators. In one embodiment, the accumulator operations are performed by a general purpose processor (e.g., a central processing unit, or CPU), or shared accumulator hardware. In that embodiment, the accumulated results (and states) of the accumulators are stored in different memory locations in the memory system. In another embodiment, the accumulators are implemented as hardware accumulators and the values to be accumulated by such accumulators are sent to them by the system. In other embodiments, one can use a combination of any of these approaches.
[0047] The above method can be applied to any signal that is section-categorizable. In the example of FIG. 6 , the section length is selected to be the chip time. However, one may select another section length, which likely leads to a greater total number of categories (K). For a binary signal, such as a GPS/GNSS signal, there are additional ways to further reduce the required arithmetic operations. Even with the section length selected to be the chip time, one can reduce the required arithmetic operations by applying a mask signal to both the samples and the center probe signal. The mask signal, denoted m s (n), may have a uniform signal value (+1 level or −1 level) for each section. In other words,
[0000] m s ( n )= m s ( cM+m )= s ( cM ) for all m<M and c<C (30)
[0000] Note that m s (n)m s (n)=1. One may also use other mask signals. For example, one may select the uniform signal value for each section of the mask signal to be the signal value of the center probe signal at the late boundary of the section. Since m s (n)m s (n)=1,
[0000]
Conv
(
y
,
s
,
x
)
=
∑
n
=
0
N
-
1
(
y
(
n
)
m
s
(
n
)
)
(
m
s
(
n
)
S
(
n
-
x
)
)
=
∑
n
=
0
N
-
1
y
m
(
n
)
s
m
(
n
-
x
)
(
31
)
[0000] where y m (n)=y(n)m s (n) is the masked sample signal and s m (n−x)=m s (n)s(n−x) is the masked shifted probe signal.
[0048] FIG. 8 illustrates masked probe signal s m (n), according to one embodiment of the present invention. As shown in FIG. 8 , probe signal 801 (i.e., probe signal s(n)) is used to construct mask signal 804 which, in turn, provides masked probe signal 804 (i.e., masked probe signal s m (n)) shows the masked probe signal s m . Each section of the masked signal 805 may be assigned to one of two categories: k=1, which has a transition within the section, or k=0, which does not have a transition within the section. Mask signal 804 transforms both a −1 level to +1 level transition and a +1 level to −1 level transition in probe signal 801 to a +1 level to −1 level transition in masked probe signal 805 . Mask signal 804 also transforms a section with a uniform +1 level signal value or a uniform −1 level signal value to a uniform +1 signal level. The value of the masked sample signal y m (n)=y(n)m s (n) may be calculated before the resulting sample is accumulated in the corresponding accumulator, while masked probe signal s m (n) may be pre-computed. The technique of masking is referred to in this detailed description as the “masking technology.” Since the number of categories is reduced by one-half in this example, the resulting circuit has a lesser footprint. In a software implementation, the number of arithmetic operations required in computing the convolutions is also correspondingly reduced.
[0049] Other ways to categorize sections of a probe signal are described next, which allow convolutions of larger offset ranges to be more efficiently calculated. For example, in one embodiment, the chip boundaries are used as section boundaries. The masking technology illustrated by Equations 30 and 31 may be applied to both the probe signal and the sample signal (i.e., the demodulated received signal). The sections of the masked center probe signal may be categorized by whether or not there is a signal value transition within the previous and the following chips. As there are 4 possible categories, the categories are denoted using 2-bit values. When there is a transition in the previous chip, the first bit of the 2-bit category is assigned a 1’; otherwise, it is assigned a ‘0’. Similarly, when there is a transition in the following chip, the second bit of the 2-bit category is assigned a ‘1’; otherwise it is assigned a ‘0’. FIG. 9 illustrates this categorization scheme for center probe signal 903 , in accordance with one embodiment of the present invention. As shown in FIG. 9 , the section boundaries are labeled 901 . The categories of the sections are provided, as indicated by reference numeral 902 . This categorization scheme provides an allowed offset range of [t c , t c ], which is twice as large as that of the single-T categorization scheme illustrated by FIG. 6 .
[0050] Similar techniques allow even greater offset ranges. In general, one may:
1. use chip boundaries as section boundaries; 2. mask both the probe signal and the sample in the manner illustrated by Equations 30 and 31; and 3. categorize the sections using values in C n previous chips and C n following chips.
[0054] Under this method, the category may be encoded by a 2C n -bit binary number, with each bit corresponding to whether or not the signal value in the current section is equal to the signal value in the corresponding one of chips at relative offsets −C n , . . . −1, 1 . . . , C n . If a signal value within a chip is the same as the signal value in the current section, the corresponding bit in the category value is ‘0’; otherwise, the corresponding bit in the category value is assigned ‘1’. As a result, the category value can be any of 2 2C n values, and the allowed offset range is [−C n t c , C n t c ].
[0055] One can also extend the allowed offset range for calculating convolution, if one sets the section boundaries at the mid-points of chips, such as shown in FIG. 6 :
1. use mid-points of the chips as section boundaries: 2. mask both the probe signal and the sample in the manner illustrated by Equations 30 and 31; and 3. categorize each section using a category value that encodes whether or not there is a transition in the current section and each of C n previous sections and C n following sections.
[0059] Under this method, the category value is a 2C n +1-bit binary number. The value of each bit corresponds to a section having one of the relative offsets: −C n , . . . −1,0,1 . . . , C n . If there is transition within the corresponding section, the corresponding bit is assigned a ‘1’; otherwise, the corresponding bit is assigned a ‘0’. The allowed offset range under this method is [−(C n +½)t c , (C n +½)t c ], and the category value may be any of 2 2Cn+1 values. FIG. 10 illustrates this method for the case C n =1. according to one embodiment of the present invention. In FIG. 10 , section boundaries 1001 are selected to be mid-points of the chips in probe signal 1003 . As category 1002 value encodes whether or not the previous, current or following chip includes a signal transition, there are 8 categories.
[0060] For binary probe signals, the number of arithmetic operations in a convolution calculation for a given relative offset x may be further reduced. For example, consider two functions v and u, where u have binary values (i.e. the value of u(i) is either 1 or −1), similar to the probe signals discussed above. Then the convolution of signals u, v for a relative offset of x is given by:
[0000]
Conv
(
u
,
v
,
x
)
=
∑
i
=
0
I
-
1
u
(
i
-
x
)
v
(
i
)
(
32
)
Conv
(
u
,
v
,
x
+
1
)
=
∑
i
=
0
I
-
1
(
u
(
i
-
x
-
1
)
-
u
(
i
-
x
)
)
v
(
i
)
+
u
(
i
-
x
)
v
(
i
)
=
Conv
(
u
,
v
,
x
)
+
∑
i
=
0
I
-
1
(
u
(
i
-
x
-
1
)
-
u
(
i
-
x
)
)
v
(
i
)
(
33
)
[0000] Because a probe signal of the type we discussed above are binary-valued, and multiple samples are taken at every chip, the value of the term u(i−x−1)−u(i−x) is often zero. Hence, Conv(u,v,x) may be calculated recursively in the following manner:
Step 1: calculate Conv(u,v,0); Step 2: initialize x=0: Step 3: calculate
[0000]
∑
i
=
0
I
-
1
(
u
(
i
-
x
-
1
)
-
u
(
i
-
x
)
)
v
(
i
)
Step 4: calculate Conv(u,v,x) using Equation (33) and the result of step 3: and
Step 5: increment x by 1 and repeat Steps 3-5 until all values of x have been computed.
[0066] For example, when v(n) if a +1 level to −1 level transition function in a section of center probe signal s(n):
[0000]
v
(
n
)
=
1
,
for
n
<
0
-
1
,
for
n
≥
0
(
34
)
Then,
[0067]
∑
i
=
0
I
-
1
(
u
(
i
-
x
-
1
)
-
u
(
i
-
x
)
)
v
(
i
)
=
2
v
(
n
)
(
35
)
[0068] Consequently, the convolution may be calculated by order M steps, using order M additions, order M subtractions and order M multiple-by-2 operations, rather than the order M 2 multiplications and additions required for a conventional calculation.
[0069] The powers of the signal and the noise of the received signal may be estimated using the convolution results. For a general digital signal h(n), its power of the signal is defined as |h(n)| 2 . Therefore, the power of signal y(n), represented by N samples, is given by:
[0000]
P
y
=
1
N
∑
n
=
0
N
-
1
y
(
n
)
2
(
36
)
[0000] Let x max to denote the relative offset that yields the maximum correlation magnitude C max , i.e.,
[0000] C max =Conv( y, s, x max ) (37)
[0000] The expected value of the gain, E[γ], is given by:
[0000]
E
[
γ
]
=
C
max
N
(
38
)
[0000] The power of the signal, P s , can be obtained using the maximum correlation value:
[0000]
P
s
=
E
[
γ
]
2
=
C
max
2
N
2
(
39
)
[0000] The signal-to-noise ratio can be calculated using:
[0000]
SNR
=
P
s
P
y
-
P
s
(
40
)
[0000] In a GPS/GNSS system, P y >>P S , so that:
[0000]
SNR
≅
P
s
P
y
(
41
)
[0000] The standard deviation σ of additive noise ε (approximated by a Gaussian distribution) can be estimated using:
[0000] σ=√{square root over (P y )} (42)
[0000] When both the signal-to-noise ratio SNR and signal power P y (or standard deviation σ) are known, the expected magnitude of the maximum convolution value C max is given by:
[0000] E[|C max |]≅N|E[γ]|=Nσ√{square root over (SNR)}=N √{square root over (( SNR ) P y 2 )} (43)
[0000] where N is the number of the samples in the convolution calculation. The expected magnitude of maximum convolution value E[|C max |] can be used to detect if the offset x is within the search range (i.e., the estimate of offset x is successful). If the measured maximum convolution value C max is too small:
[0000] |C max |<α cmax E[|C max |] (44)
[0000] where α cmax is a design parameter, then the relative offset x is likely out of range. In some embodiments, one may choose α cmax =10.
[0070] In some embodiments, one or more samples may be skipped (i.e., not accumulated in the accumulators). In one embodiment, for an offset search range of [t c /2, t c /2], using single-T categorization and masking as discussed above, the contribution of a sample in a non-transition section (i.e., category 0) to each convolution is the same, regardless of the relative offset. Hence, contributions by “category 0” sections do not change the relative likelihood for any relative offset x. Thus, such sections do not affect the end result after normalization. Thus, accumulation of samples in category 0 sections may be skipped.
[0071] In each section, the relative offset x of the samples in the section is defined with respective of center probe signal s(n). The original sample's index is represented by n=cM+m, where c is the section number and m is sample section index. Within a given section, if center probe signal s(n) has a transition just between sample index
[0000]
m
=
M
2
-
1
[0000] and sample index
[0000]
m
=
M
2
,
[0000] sample index
[0000]
m
=
M
2
-
1
[0000] is the time point defined to have a relative offset x =0. Therefore, s(cM+m) has a relative offset
[0000]
x
=
m
-
M
2
+
1.
[0000] In one embodiment, M is chosen to be an even number. In other embodiments, where M is an odd number, one can use floor(M/2) instead of M/2 to be the time point with zero relative offset.
[0072] The total number of arithmetic operations may be further reduced, taking advantage of the probability distribution of offset x. For example, taking into account samples that have been taken and processed, offset x is more likely to be within a smaller range of relative offsets. In one embodiment, calculations involving samples that are unlikely to correspond to a rapidly changing portion of the probe signal can be skipped. The rapidly changing part of a binary probe signal is the part that is close in time to where a transition from +1 level to −1 level, or from level −1 to level +1, occurs. The samples that are unlikely to correspond to a rapidly changing part of the probe signal are likely to correspond to an unchanging part of the probe signal. Thus, these samples are unlikely to contribute to a measure that distinguishes between the likelihood of different offsets, and thus may be skipped (i.e., need not be accumulated in the corresponding accumulators).
[0073] In category 1 sections (i.e., sections in which a transition occurs in the corresponding probe signal) under single-T categorization and masking, the probability that a transition happens just after the sample at relative offset x equals the probability that the received signal has relative offset x. Hence, one can use the probability of the relative offset to determine which samples may be skipped. If the probability of relative offset x is smaller than a certain threshold, the calculations corresponding to relative offset x may be skipped.
[0074] Other probabilities may also be used to determine which samples in sections that are not likely to have a transition may be skipped. For example, in one embodiment, an average of probabilities P(n−1) and P(n) can be used to determine if the sample at relative offset n may be skipped:
[0000] P 2 ( n )=½[ P ( n )+ P ( n− 1)] (45)
[0000] This is because, when n is out of the search range for relative offset x, P(n)=0. Average probability P 2 (n) should be normalized, if needed. Another way to determine to skip is to use a cumulative probability:
[0000]
P
c
(
n
)
=
∑
i
=
0
n
P
(
i
)
(
46
)
[0000] Under this scheme (“probability threshold scheme”), one may select a value P c0 , and skip the samples at certain relative offsets c when P c <P c0 or 1−P c <P c0 . In some embodiments, P c0 may be chosen to have a value between 0.1 and 0.3, for example. Alternatively, P c0 may be adjusted empirically or determined by a simulation.
[0075] FIG. 11 shows how, using the probability threshold scheme, the probability distribution of relative offset x evolves in time for category 1 sections under single-T categorization and masking (i.e., sections in which a transition occurs in the corresponding probe signal), in accordance with the present invention. In FIG. 11 , accumulations of samples in unchanging sections have been skipped. Initially, illustrated by probability distribution 1101 , the probability distribution for relative offset x is assumed to be uniform. The probability distribution for relative offset x evolves in time as illustrated in order by probability distributions 1101 , 1102 , 1103 . 1104 , 1105 , 1106 , 1107 , and 1108 . Each bar (e.g., bar 1110 ) provides the probability value corresponding to a relative offset value (e.g., relative offset value 1112 ). Line 1111 represents the threshold probability value. If the probability for relative offset x is less than the threshold probability value, samples corresponding to that relative offset are skipped.
[0076] New samples are taken and added to accumulators A(k,m) continuously. The accumulators are not reset between iterations. A convolution is calculated in between two iterations (e.g., iterations of steps 1201 to 1209 , for the method illustrated in in FIG. 12 ) in order to calculate a probability distribution. In some embodiments, the accumulators may be adjusted for the time passed before a convolution is calculated (the probability distribution is thereby adjusted as well).
[0077] Probability distribution 1102 results after some samples of the demodulated received signal have been taken and processed. The probabilities of relative offsets −3 and 4 are found less than threshold 1111 . Hence, samples of the demodulated signal at relative offsets −3 and 4 are skipped in the next iteration, leading to probability distribution 1103 . At this point, the probabilities of relative offsets −3, −2, 3, and 4 fail below probability threshold value 1111 and thus samples at these relative offsets are skipped in the next iteration. Additionally, samples at relative offsets −1 and 2 are skipped in the following iterations based on probability distribution 1104 and 1105 .
[0078] During this process, although samples at certain relative offsets are skipped, the convolutions of all relative offsets inside the search range are still calculated. The skipped samples are not accumulated, which is equivalent to having a zero signal value). Thus, the probability of any relative offset may still change (and may sometimes even become larger). For example, even though samples corresponding to relative offset −1 are not accumulated immediately after probability distribution 1104 is presented, the probability of relative offset −1 in a subsequent probability distribution (i.e., probability distribution 1106 ), the probability for relative offset −1 actually increased. In the iteration after probability distribution 1106 is presented, accumulation of samples at relative offset −1 resumes. By keeping track of the probabilities for all (or at least some) relative offsets in the search range whether or not samples are accumulated for some of the relative offsets within the range, the resulting method is robust to statistical fluctuations.
[0079] Often, a single relative offset remains that exceeds threshold 1111 , such as shown for relative offset 0 in probability distribution 1107 . In one embodiment of the invention, the sampling and the probability updates are kept running after that event, such as illustrated by probability distribution 1108 , which results after one or more iterations following probability distribution 1107 .
[0080] The number of samples that is accumulated before each probability distribution (or other statistical states) is computed need not be fixed. Selecting an appropriate value at any given time is a trade-off between avoiding accumulating samples that should be skipped and avoiding computing probability updates too often. The optimal value minimizes the overall amount of computation, which results in reduced power consumption.
[0081] Sample-skipping may be implemented in any of a number of different stages in the system. For example, in one embodiment, the signal samples that are skipped are received into the analog-digital converter (ADC). In another embodiment, the signal samples are received into the ADC, but the converted digital samples are not saved into memory. In another embodiment, the samples are saved in memory but are not provided to the accumulators.
[0082] Signal samples maybe buffered by the system. In one embodiment, each sample is processed directly after it is received into the ADC. In another embodiment, after digitization in the ADC, the samples may be buffered in memory for processing at a later time.
[0083] Sample-skipping is based on the principle that one can avoid taking or using samples that have such a low probability of contributing to a probability distribution as to affect differentiating among the high-probability possible offsets of the signal. This result can be achieved in many in different ways. In some embodiments, one can achieve the same or similar results by adjusting the sampling frequency:
[0084] 1. taking samples at a lower initial sampling rate;
[0085] 2. calculating a probability distribution of the possible offsets;
[0086] 3. when a range of offsets have probabilities that are significantly less than the others, those low-probability offsets are marked to be skipped;
[0087] 4. when the remaining offset range (i.e., the range of offsets corresponding to samples that are not skipped) is small enough (e.g., less than a half of the previous range), increasing the sample frequency (e.g., by a factor of 2); and
[0088] 5. repeating steps 2-5 until the desired offset resolution is archived.
[0089] The value in the accumulator for the samples at the corresponding relative offset may be used to provide a finer estimate for the relative offset, e.g., an estimate with a resolution finer than the sampling time.
[0090] In one embodiment, the system keeps track of the number of samples N s (k, x) that are added into the accumulator, where k is the category and x is the relative offset. The relative offset translates into the sample index by the relation M=x+M/2−1. (The accumulator value can also be looked up A (k, x), using this relation.)
[0091] Denote a sub-sample portion of the relative offset to be x s . When a transition occurs just after the sample at relative offset x, i.e. x s =0, the expected value of the accumulator (denoted as A(1, x), where 1 denotes the category that has a signal transition)
[0000] Ā=N s (1, x )√{square root over (( SNR ) p y )} (47)
[0000] where, p y is the average power of the demodulated signal and where SNR is the signal-to-noise ratio of the demodulated signal. When the transition occurs just before the sample, i.e. x s ≈−1, the expected accumulated value in the accumulator is −Ā. The fractional relative offset x s of the sample can be calculated by interpolating between the cases.
[0000]
x
s
=
A
(
1
,
x
)
2
A
_
-
1
2
(
48
)
[0092] Note that A(1, x) in equation 48 represents accumulation of the samples of the demodulated received signal. Thus, A(1, x) is presumably a real number. Any imaginary part can be disregarded in equation 48. The overall estimate of the relative offset x a is given by:
[0000] x a ( x )= x+x s ( x ) (49)
[0000] When there are more than one estimated relative offset, the overall offset x may be estimated by a weighted sum of the x a (x):
[0000]
x
_
=
∑
x
P
(
x
)
x
a
(
x
)
(
50
)
[0000] where P(x) is the probability of relative offset x. In some embodiment the summation is over all x in the search range. In other embodiments, the summation can be over only the relative offsets that has probability larger than the probability threshold. Equation 50 provides a better estimation of the offset than the expected value of the probability distribution. However, when the probability is widely distributed over the search range, Equation 50 may not be effective. Hence, a simple expected value method may be more appropriate in some embodiments.
[0093] The system may change over the time samples are taken and processed. For example, the user's location may change, the local clock may drift, or other conditions may change. In some embodiments, such changes may be significant. One way to handle such changes is to update the probability distributions over time, such as to let the convolution values (or, equivalently, the log likelihood) fade away over time:
[0000]
conv
t
(
y
,
s
,
x
)
=
-
t
τ
conv
0
(
y
,
s
,
x
)
(
51
)
[0000] where conv 0 (y,s,x) is the convolution value at an initial time point and conv t (y,s,x) is the convolution value after a time interval τ (i.e., the fading time). Variable τ may be seen as a design parameter that depends on the dynamics of the object being measured. Roughly, a sample that is taken more than a predetermined time r prior to the current time should not contribute significantly to the current convolution value. For example, in one embodiment, for an object moving at a speed of about 30 meters per second, variable τ may be set to one second. Variable τ may also be adjusted empirically or determined by simulation.
[0094] As new samples are taken, the convolution calculated using the new samples may be added to the then existing convolution values. Therefore, the accumulator values can also be faded:
[0000]
A
t
(
k
,
x
)
=
-
t
τ
A
0
(
k
,
x
)
(
52
)
[0095] The un-normalized log likelihood may also be similarly faded:
[0000]
L
t
=
-
t
τ
L
0
(
53
)
[0096] Many of the specific embodiments discussed in this detailed description are selected for notation convenience. Many variations may be used to achieve the same results, For example, in one embodiment, one may use the following procedure:
[0097] 1. take samples around the transitions of the signal;
[0098] 2. adjust the sign of the samples taken according the direction of signal transition (i.e., from level +1 to level −1 or from level −1 to level +1);
[0099] 3. calculate the convolutions by first grouping the samples.
[0100] This procedure is equivalent to the masking-categorization (with k=1) procedure described above in conjunction with FIG. 8 .
[0101] Note that different components of this invention can be selected to use or not use in different embodiments of this invention. For example, in one embodiment, one can chose to only use the skipping method to reduce the total amount of calculation. One can take samples that are expected to be close to the jumps of the signal and skip the samples that are expected to be far away from the jumps. Then, one can use the traditional method of calculate convolution based on those signals. In that embodiment, the categorization component is not used, however, total mount of calculation/power is still reduced comparing to the methods without skipping.
[0102] Numerical oscillator 203 of FIG. 2 may operate based on estimations of the phase φ and the frequency f of the IF carrier signal from RF front end 201 . One implementation of NCO 203 may provide both in-phase and quadrature signals:
[0000] N I ( n )=cos(φ+2 nπf t s )
[0000] N Q ( n )=sin(φ+2 nπf t s ) (54)
[0000] In some embodiments, one can simply use binary signals rather than sin and cos signals:
[0000] N I ( n )=sign(cos(φ+2 nπf t s ))
[0000] N Q ( n )=sign(sin(φ+2 πf t s )) (55)
[0000] Where sign(·) is the sign function:
[0000] sign(x)=1 f or x<0
[0000] −1, f or x≧0 (56)
[0103] To avoid costly floating-point calculations, angular rate ω=2πf t s and phase φ may both be represented as integers. The sign(cos(x)) and the sign(sin(x)) can be calculated using the total phase at sample n, which is given by: φ n =φ+ωn.
[0104] The RF front end (e.g., RF Front end 102 of FIG. 1 ) removes most of the frequency modulation from the received signal. Any remaining frequency modulation may be removed by a channel-specific demodulator, which is achieved using:
[0000] I O ( n )= I i ( n ) N I ( n )− Q i ( n )N Q ( n )
[0000] Q O ( n )= I i ( n ) N Q ( n )+ Q i ( n ) N I ( n ) (57)
[0000] where I O (n) and Q O (n) are the output data samples, and I i (n) and Q i (n) are the data samples.
[0105] In some embodiments, frequency and phase estimations can be done using conventional frequency and phase tracking loops. To reduce the amount of calculations and the power consumption, the following or a similar method may be used.
[0106] Coarse estimation (or signal acquisition) provides an initial estimation of the frequency modulation. Initially, the phase and the frequency of NCO 203 may be set to zero or any other convenient initial value. Then, samples may be taken for the signal acquisition calculations. After signal acquisition, the frequency and phase of NCO 203 may be set to initial values:
[0000] f=f 0 ; φ=0 (58)
[0000] where f 0 is the frequency estimation from the signal acquisition. Next, one way to estimate the phase is to take some samples during a time interval T c and calculate a number of convolutions over the search range determined by the signal acquisition step. The phase φ m of the convolution with the maximum absolute value, C max , provides an estimation of the average remaining phase during the time interval T c .
[0000] φ m =phase( C max ) (59)
[0000] In a preferred embodiment of the invention, T c is chosen using the following criteria:
1. T c should be short enough so that phase change δφ during the time period is small. For example, one criterion for T c may be:
[0000]
T
c
<
δ
φ
1
2
π
δ
f
(
60
)
[0000] where δf is the frequency resolution and δφ 1 is a selected phase error. The phase change δφ of the received signal over selected interval T c will be less than δφ 1 . In some embodiments δφ 1 can be chosen between π/6 and π/2.
2. T c should be chosen large enough so that enough samples may be taken for making a reliable phase measurement. For example, one criterion for T c may be:
[0000]
T
c
>
(
δ
φ
2
)
2
t
s
SNR
(
61
)
[0000] In some embodiment the phase error δφ 2 may be a value selected between π/6 and π/4.
[0109] The frequency can be estimated by performing two phase estimations separated by time interval T m . T m may be selected to be as long as possible, but is kept short enough so that the phase change during the period should be less than 2π, so as to avoid phase skipping. That is,
[0000] T m δf2π<2π (62)
[0000] where δf is the accuracy of the frequency estimation before the phase measurements. This implies:
[0000]
T
m
<
1
δ
f
(
63
)
[0000] In some embodiment, a safety margin may be applied (e.g., T m =0.3/δf).
[0110] Denote the results of a first and second phase measurements φ m1 and φ m2 and their accuracies (i.e., resolutions) δφ 1 and δφ 2 , respectively. The measured frequency may be obtained by:
[0000]
f
m
=
φ
m
2
-
φ
m
1
T
m
(
64
)
[0000] The accuracy of frequency, δf after the two measurements is given by:
[0000]
δ
f
=
δφ
1
2
-
δφ
2
2
T
m
(
65
)
[0000] After the measurements, the phase and the frequency of the numerical oscillator may be updated using the following relations:
[0000] φ + =φ − −φ m2
[0000] f + =f − −f m (66, 67)
[0000] where φ − and f − are the phase and frequency of the NCO before the update and φ + and f + are the phase and frequency of the NCO after the update, respectively.
[0111] In one embodiment, this two-step phase-frequency update is run each time prior to performing a fine offset estimation. In some other embodiment, this two-step phase-frequency update is run multiple times recursively until a certain frequency accuracy level is achieved. For example, recursive updates may run until δf<10 Hz.
[0112] In one embodiment of the invention, a Kalman filter can be used to estimate the phase and frequency. This is a more robust and accurate method than the two-step phase-frequency method, at the expense of greater computation (i.e., greater power).
[0113] The state variables for the Kalman filter may be phase and frequency:
[0000]
X
=
[
φ
f
]
(
68
)
[0114] The state update matrix A may be modeled as:
[0000]
A
=
[
1
2
π
t
m
0
1
]
(
69
)
[0115] The process noise may be modeled by:
[0000]
w
=
[
w
φ
w
f
]
(
70
)
[0000] where w φ and w f denote the process phase noise and frequency noise, respectively. These noises are introduced by the local clock oscillator and user movement. The state update function is thus:
[0000] X n+1 =AX n +w (71)
[0000] The variance of w may be determined by the specification of the oscillator and the dynamics of the application. In one embodiment, the variances of the process error may be modeled as being proportional to the time passed:
[0000] σ φ 2 =P φ t m
[0000] σ f 2 =P f t m (72)
[0000] where P φ and P f are the power of the phase random-walk noise and the power of the frequency random-walk noise, respectively. Both the phase random-walk noise and the frequency random-walk noise may be a combination of a clock phase or frequency random-walk noise and a phase or frequency random-walk noise due to the receiver's random motion. In practice, P φ and P f can be estimated from the clock specification and the dynamics of the receiver. These parameters may also be adjusted empirically or by simulation until acceptable performance is reached. In another embodiment, the variances, as functions of time t m , may be estimated by measuring the Allan Variance of the local clock, and considering the receiver's dynamics. The process error covariance matrix is
[0000]
∑
w
=
[
σ
φ
2
0
0
σ
f
2
]
(
73
)
[0000] Denote the measurement of the remaining phase as φ m , which can be obtained using Equation 59 above. Alternatively, if the remaining phase is small and the noise level is high, φ m may be obtained using:
[0000]
φ
m
=
phase
(
imag
(
C
max
)
E
[
C
max
]
)
(
74
)
[0000] where imag(·) is the function that extracts the imaginary part of a complex number. E[|C max |] denotes the expected value of the magnitude of C max . The measurement Y is given by:
[0000] Y=CX+u (75)
[0000] where u denotes the measurement noise and C denotes the output matrix:
[0000] C=[1 0] (76)
[0000] The variance σ u 2 of u, which is a design parameter, is given by:
[0000]
σ
u
2
=
t
c
SNR
t
s
(
77
)
[0000] The measurement y(n) is calculated using:
[0000] y ( n )=φ m +φ( n ) (78)
[0000] The covariance of the measurement is:
[0000] Σ u =[σ u 2 ] (79)
[0000] The Kalman filter maintains an estimation of X and its covariance matrix Σ u base on parameters A, C, Σ w , Σ u , measurements y and the time of the measurements. The Kalman filter's time update and measurement update can be performed using the conventional Kalman filter constructs:
[0116] 1. Time update:
[0000] X n+1 =AX n
[0000] Σ X n+1 =AΣ X n A T +Σ w (80, 81)
[0117] 2. Measurement update:
[0000] X n + =X n − +Σ X n − C T ( CΣ X n − C T +Σ u ) −1 ( y n −CX )
[0000] Σ X n + =Σ X n − +Σ X n − C T ( CΣ X n − C T +Σ u ) −1 CΣ X n − (82, 83)
where X n − and X n + denote the state variable before and after the measurement update, Σ X n − and Σ X n + denote the state covariance matrices before and after the update. Also note that y n −CX=φ m in equation 83.
The Kalman filter's covariance matrix Σ X offers a good estimate of the frequency error or accuracy δf, which may be used to determine the time interval T m between measurements:
[0000]
T
m
>
1
δ
f
(
84
)
[0000] or with a safety factor α s <1.
[0000]
T
m
<
α
s
δ
f
(
85
)
[0000] In one embodiment α s =0.3, so as to avoid phase wrapping or skipping and phase accuracy may be maintained. The duration of convolution time t c can be similarly determine, using the two-step phase-frequency method described above.
[0119] In one embodiment of the invention, the behavior of the phase-frequency Kalman filter is coupled with status of the offset measurement:
1. choose the number of samples needed for convolution at the current SNR, such that the signal-to-noise ratio SNR of the convolution result satisfies the following equation with design parameter α c ≅1.
[0000]
N
=
α
c
1
SNR
(
86
)
Design parameter ac may be chosen empirically or by simulation. For example, in one embodiment, α c =0.5.
2. determine the convolution time t c , taking into consideration the number of skipped samples, so that N samples are expected to be taken during t c :
[0000]
t
c
=
2
t
s
N
M
M
-
M
s
(
87
)
where M s is the number of samples that are skipped in each section that contains a signal transition (i.e., in each category 1 section). The factor 2 results from the fact that about half of the sections are non-changing sections (i.e., category 0 sections).
3. adjust the convolution time.
Calculate the phase error during next convolution time t c , using
[0000] δφ=2πδf t c (88)
If the phase error δφ is larger than a predetermined threshold φ α , the convolution time is reduced to reduce the phase error:
[0000]
t
c
0
=
φ
α
2
πδ
f
(
89
)
t c0 is the “phase stable” time. In one embodiment one can select φ α to be π/4. If t c <t c0 , one may use t c0 as t c . If t c0 is longer than a certain threshold, one may skip a phase-frequency update. For example, the predetermined threshold may be α tc t c , where α tc is a design parameter, with a typical value greater than 2.
4. determine if samples should be skipped based on a previous estimate of the probability distribution, and whether or not a phase-frequency update is necessary. If the phase-update is necessary, the samples are not skipped.
5. calculate the convolutions, and update the SNR, the offset measurement, and the phase-frequency Kalman filter.
6. If the accuracy of the offset does not reach the predetermined value, repeat from step 1; otherwise, output the offset and keep the system in sleep or idle mode until next time when the next offset estimate is required. For example, when the system is required to have an offset output rate of 1 Hz, the system may go into sleep mode for a timer period equal to 1 second minus the time required to obtain an offset estimate with the required accuracy. That time required may be estimated based the time taken for the last offset estimate.
7. After “waking up” from the sleep mode, update the offset probability distribution and the Kalman filter according to the time passed. Then, repeat from step 1.
[0132] Putting a system into a sleep mode—in which minimal energy is used—reduces the overall energy cost.
[0133] Sample skipping may be realized not just at the accumulators described above. For example, if a sample need not participate in any of the computation, the sample can be skipped at the RF front end (e.g., not even selected for analog-to-digital conversion). Alternatively, a sample may be skipped in an offset estimator.
[0134] Multi-path is a major source of error in a GPS receiver and other time-of-flight measurement systems. The multi-path error can be detected using the accumulator results of the sections that have a transition (i.e., category 1 sections, when single-T categorization and masking are used). In one embodiment, a difference in accumulated values between adjacent samples A δ (x) may be used to find the signal that arrived the earliest, which is more likely to be a line-of-sight path:
[0000] A δ ( x )= A (1, x )− A (1, x− 1) (90)
[0000] In this regard, the total number of samples N s2 (x) accumulated in the two accumulators is a useful parameter, given by:
[0000] N s2 ( x )= N s (1, x )+ N s (1, x− 1) (91)
[0000] When the following inequality is satisfied for any relative offset x, one may consider a signal detected:
[0000] | A δ ( x )|>α A √{square root over ( N s2 p y )} (92)
[0135] Among the detected signal, the one with the earliest relative offset may be considered a line-of-sight signal. α A is a design parameter, which is a given value between 2 and 3, in one embodiment. To avoid a multi-path error, skipping samples that contribute to measuring an early signal should be avoided. In one embodiment, a sample is skipped when:
1. all samples with a greater relative offset (i.e., samples of later arrival) are skipped: or 2. the sample has a greater offset (i.e., samples of arrival) than the offset of a signal detected based on equation 92.
[0138] The phase measurement may be obtained using any carrier-phase method that can be used to estimate an object's position. Carrier-phase methods are described, for example, in the GPS/GNSS literature (e.g., “Global Position System: Signals, Measurement and Performance” (“Enge”), by Pratap Misra and Per Enge, and its cited references).
[0139] In a multipath environment, different components of the signal arriving at different times to the receiver have different phases. The accumulator values and the convolution results can be used to improve the phase estimation of the line-of-sight signal. In one embodiment, one can use the phase of the convolution value of the earliest arriving signal as the carrier phase, since it is a good estimate of the carrier phase of the signal of the shortest path (i.e., the line-of-sight signal). In another embodiment, one can detect the second earliest arriving signal using a method that is similar to that used to detect the earliest arriving signal discussed above). If the second earliest arrived signal is detected, one can use the accumulator values that are associated with offsets earlier or equal to the offset of the second earliest arrived signal to calculate the carrier phase of the line-of-sight signal. In another embodiment, for simplicity, one can use the accumulator values that are associated with offsets earlier or equal to the offset of the earliest arrived signal to calculate the carrier phase of the line of sight signal.
[0140] In applying any of the methods described above, one may trade-off between performance, power consumption and complexity. In some embodiments, some of the techniques described are not be used, or may be adjusted for a given application. For example, while the probability distribution is used in some embodiments for offset measurement, other methods exist that do not probability distribution directly. For example, in one embodiment a set of statistical states S(x) is kept by the system. In that embodiment, offset measurement is achieved by:
1. initialize S(x) by the log likelihood of the prior probability distribution of relative offset
[0000] S ( x )= L ( x ) (93)
2. accumulate samples and calculate convolutions using these samples. Denote the result of the convolution for relative offset x as C b (x): 3. construct function C b ′(x) such that the sum of C b ′(x) over all relative offset x in the search space for relative offsets is zero; that is:
[0000]
C
b
′
(
x
)
=
C
b
(
x
)
-
1
N
x
∑
x
C
b
(
x
)
(
94
)
where N x is the number of estimated offsets over the search space.
4. update S(x) using:
[0000] S + ( x )= S − ( x )+α sc C b ′( x ) (95)
where S − (x) and S + (x) are the states before and after the update, and where α sc is a design parameter, having the value, for example, 0.3 in one embodiment. 5. keep only the positive terms in S(x)
[0000]
S
(
x
)
=
{
S
+
(
x
)
,
S
+
(
x
)
>
0
0
,
otherwise
(
96
)
6. skip samples with relative offset x, if S(x)=0
7. Repeat 2-6 until only one relative offset x remains; at which point, report relative offset x as the offset estimation.
[0150] In this method, statistical state S(x) provides an indicator of the probability distribution. When S(x) is small (e.g., S(x)=0), the corresponding probability P(x) of relative offset x is small, and thus the corresponding samples may be skipped.
[0151] The above detailed description is provided to illustrate specific embodiments of the present invention and is not intended to be limiting. Numerous variations and modifications within the scope of the present invention are possible. The present invention is set forth in the accompanying claims. | 4y
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RELATED APPLICATION DATA
The benefit of U.S. Provisional Patent Application No. 60/736,721, filed 15 Nov. 2005, entitled THERMALLY CONTAINED/INSULATED PHASE CHANGE MEMORY DEVICE AND METHOD, is hereby claimed.
PARTIES TO A JOINT RESEARCH AGREEMENT
International Business Machines Corporation, a New York corporation; Macronix International Corporation, Ltd., a Taiwan corporation, and Infineon Technologies A.G., a German corporation, are parties to a Joint Research Agreement.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to high density memory devices based on programmable resistive memory materials, including phase change materials and other materials, and to methods for manufacturing such devices.
2. Description of Related Art
Phase change based memory materials are widely used in read-write optical disks. These materials have at least two solid phases, including for example a generally amorphous solid phase and a generally crystalline solid phase. Laser pulses are used in read-write optical disks to switch between phases and to read the optical properties of the material after the phase change.
Phase change based memory materials, like chalcogenide based materials and similar materials, also can be caused to change phase by application of electrical current at levels suitable for implementation in integrated circuits. The generally amorphous state is characterized by higher resistivity than the generally crystalline state; this difference in resistance can be readily sensed to indicate data. These properties have generated interest in using programmable resistive material to form nonvolatile memory circuits, which can be read and written with random access.
The change from the amorphous to the crystalline state is generally a lower current operation. The change from crystalline to amorphous, referred to as reset herein, is generally a higher current operation, which includes a short high current density pulse to melt or breakdown the crystalline structure, after which the phase change material cools quickly, quenching the phase change process, allowing at least a portion of the phase change structure to stabilize in the amorphous state. It is desirable to minimize the magnitude of the reset current used to cause transition of phase change material from crystalline state to amorphous state. The magnitude of the reset current needed for reset can be reduced by reducing the size of the phase change material element in the cell and by reducing the size of the contact area between electrodes and the phase change material, so that higher current densities are achieved with small absolute current values through the phase change material element.
One direction of development has been toward forming small pores in an integrated circuit structure, and using small quantities of programmable resistive material to fill the small pores. Patents illustrating development toward small pores include: Ovshinsky, “Multibit Single Cell Memory Element Having Tapered Contact,” U.S. Pat. No. 5,687,112, issued Nov. 11, 1997; Zahorik et al., “Method of Making Chalogenide [sic] Memory Device,” U.S. Pat. No. 5,789,277, issued Aug. 4, 1998; Doan et al., “Controllable Ovonic Phase-Change Semiconductor Memory Device and Methods of Fabricating the Same,” U.S. Pat. No. 6,150,253, issued Nov. 21, 2000; Chen, “Phase Change Memory Device Employing Thermally Insulating Voids,” U.S. Pat. No. 6,815,704 B1, issued Nov. 9, 2004.
Problems have arisen in manufacturing such devices with very small dimensions, and with variations in process that meet tight specifications needed for large-scale memory devices. It is desirable therefore to provide a memory cell structure having small dimensions and low reset currents, and a method for manufacturing such structure.
SUMMARY OF THE INVENTION
A first aspect of the invention is directed to a thermally insulated memory device comprising a memory cell access layer and a memory cell layer, operably coupled to the memory cell access layer. The memory cell layer comprises a memory cell, the memory cell comprising: first and second electrodes having opposed, spaced apart electrode surfaces; a via extending between the electrode surfaces; a thermal insulator within the via, the thermal insulator comprising a sidewall structure in the via defining a void extending between the electrode surfaces; and a memory material such as a phase change material, within the void electrically coupling the electrode surfaces. The thermal insulator helps to reduce the power required to operate the memory material. In some embodiments the memory cell layer comprises an inter-electrode insulator made using a separation material through which the via extends, and the thermal insulator has a thermal insulation value greater than a thermal insulation value of the separation material. The thermal insulator may define a sidewall structure having an inside surface tapering inwardly from the electrode surface of the second electrode towards the electrode surface of the first electrode so that a cross-sectional area of the insulated via is smaller at the first electrode than at the second electrode, forming a void having a constricted region near the first electrode member, the memory material element being at the constricted region. The memory cell access layer may comprise an outer surface and an electrically conductive plug extending to the outer surface form underlying terminals formed for example by doped regions in a semiconductor substrate, the plug having a plug surface, the plug surface constituting a portion of the outer surface; and the first electrode overlying at least a substantial portion of the plug surface; whereby at least some imperfections at the plug surface are accommodated by the first electrode. In embodiments described herein, the electrode surface first electrode is substantially planar, in the region of the via, where substantially planar surface can be formed for example by chemical mechanical polishing or other planarizing procedures that intend to improve the planarity of the electrode surface relative to the electrode material as deposited and prior to planarization.
A second aspect of the invention is directed to a method for making a thermally insulated memory device. A memory cell access layer is formed on a substrate, the memory cell access layer comprising an upper surface. A first electrode layer is deposited and planarized on the upper surface. A inter-electrode layer is deposited on the first electrode layer. A via is created within the inter-electrode layer. A thermal insulator having an open region is formed within the via, by for example forming sidewall structures on sidewalls of the via. A memory material is deposited within the open region. A second electrode layer is deposited over and in contact with the memory material. According to some embodiments the material of the thermal insulator has a thermal insulation value greater than the thermal insulation value of the separation material used for the inter-electrode layer.
A third aspect of the invention is directed to plug-surface void-filling memory device comprising a memory cell access layer comprising an outer surface and an electrically conductive plug extending to the outer surface, the plug having a plug surface, the plug surface constituting a portion of the outer surface, the plug surface having an imperfection; and a memory cell layer contacting the memory cell access layer, the memory cell layer comprising a memory cell. The memory cell comprises first and second electrodes having opposed, spaced apart electrode surfaces, the first electrode contacting at least a substantial portion of the plug surface; and a memory material electrically coupling the electrode surfaces to create a memory material element; whereby the imperfection at the plug surface is accommodated by the first electrode. In some embodiments a void-type imperfection at the plug surface is filled by depositing and planarizing the material used to form the first electrode.
A fourth aspect of the invention is directed to a method for accommodating an imperfection in an outer surface of an electrically conductive plug of a semiconductor device. The method comprises depositing an electrode on the outer service of the plug.
The method described herein for formation of the phase change element for use in a memory cell in a phase change random access memory (PCRAM) device, can be used to make small phase change elements, bridges or similar structures for other devices.
Various features and advantages of the invention will appear from the following description in which the preferred embodiments have been set forth in detail in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a simplified cross-sectional view of a phase change memory device made according to the invention;
FIGS. 2-11 illustrate a method for making phase change memory devices, such as the device of FIG. 1 ;
FIG. 2 illustrates the final stages for making the memory cell access layer of FIG. 1 ;
FIG. 3 illustrates the deposition of a first electrode layer on top of the memory cell access layer of FIG. 2 ;
FIG. 4 illustrates the result of depositing an oxide layer onto the first electrode layer of FIG. 3 ;
FIG. 5 shows vias formed in the oxide layer of FIG. 4 ;
FIG. 6 illustrates thermal insulators deposited within the vias of FIG. 5 ;
FIG. 7 shows phase change material deposited within the central open regions of the thermal insulators of FIG. 6 ;
FIG. 8 illustrates a second electrode layer deposited onto the structure of FIG. 7 ;
FIG. 9 illustrates the formation of a lithographic mask overlying certain areas on the second electrode layer;
FIG. 10 illustrates the result of etching the structure of FIG. 9 ; and
FIG. 11 shows the structure of FIG. 10 after deposition of an oxide within the etched regions.
FIG. 12 illustrates an alternative embodiment of a phase change memory device.
DETAILED DESCRIPTION
The following description of the invention will typically be with reference to specific structural embodiments and methods. It is to be understood that there is no intention to limit the invention to the specifically disclosed embodiments and methods but that the invention may be practiced using other features, elements, methods and embodiments. Like elements in various embodiments are commonly referred to with like reference numerals.
FIG. 1 is a simplified cross-sectional view of a phase change memory device 10 made according to one embodiment of the invention. Device 10 comprises broadly a memory cell access layer 12 formed on a substrate, not shown, and a memory cell layer 14 formed on top of access layer 12 . Access layer 12 typically comprises access transistors; other types of access devices may also be used. Access layer 12 comprises first and second polysilicon word lines acting as first and second elements 16 , 18 , first and second plugs 20 , 22 and a common source line 24 all within a dielectric film layer 26 .
Phase change memory device 10 and its method of manufacturer will be described with reference to FIGS. 2-11 . Referring now to FIG. 2 , memory cell access layer 12 is seen to have a generally flat upper surface 28 , the upper surface being interrupted by voids 30 formed in plugs 20 , 22 and by void 32 formed in common source line 24 . Voids 30 , 32 , or other surface imperfections, are formed as an artifact of the deposition process used for formation of tungsten plugs within small dimension vias. Deposition of, for example, a phase change material directly onto the upper surfaces 33 of plugs 20 , 22 can create a distribution problem, that is create an increased variance in the operational characteristics of the devices, due to the existence of voids 30 .
FIG. 3 illustrates the results of TiN deposition to create a first electrode layer 34 and chemical mechanical polishing CMP of layer 34 to create a planarized surface 36 . Layer 34 is preferably about 100 to 800 nm thick, typically about 500 nm thick after planarization. First electrode layer 34 fills voids 30 , 32 to effectively eliminate the distribution problem that could be created by the voids or other surface imperfections. Planarization removes artifacts of the voids that result from deposition of the electrode material layer 34 . An inter-electrode layer 38 , see FIG. 4 , is deposited on layer 34 . Layer 38 may comprise one or more layer of an electrical insulator such as silicon dioxide, or variants thereof, is preferably about 40 to 80 nm thick, typically about 60 nm thick for the illustrated example. Vias 40 , see FIG. 5 , are formed in inter-electrode ayer 38 , typically using an appropriate lithographic mask, not shown, generally centered, within alignment tolerances of the manufacturing processes, above plugs 20 , 22 . Vias 40 have a diameter of about the technology node, that is about 90 to 150 nm, typically about 130 nm for a technology node having a minimum lithographic feature size of 0.13 microns.
A thermal insulator 42 is formed within each via 40 , using a conformal deposition process such as chemical vapor deposition (CVD). Thermal insulator 42 is a better thermal insulator than the material of inter-electrode layer 38 , preferably at least 10% better. Therefore, thermal insulator 42 has a thermal conductivity value kappa of less than 0.014 J/cm/K/sec. Representative materials for thermal insulator 42 include materials that are a combination of the elements silicon Si, carbon C, oxygen O, fluorine F, and hydrogen H. Examples of thermally insulating materials which have a thermal insulation value kappa of greater than 0.014 J/cm/° K/sec. and are candidates for use as thermal insulator 42 include SiCOH, polyimide, polyamide, and fluorocarbon polymers. Other examples of materials which are candidates for use for thermal insulator 42 include fluorinated SiO 2 , silsesquioxane, polyarylene ethers, parylene, fluoro-polymers, fluorinated amorphous carbon, diamond like carbon, porous silica, mesoporous silica, porous silsesquioxane, porous polyimide, and porous polyarylene ethers. In other embodiments, the thermally insulating structure comprises a gas-filled void lining the walls of via 40 . A single layer or combination of layers can provide thermal insulation.
Thermal insulator 42 is preferably formed as sidewall stucture to create the generally conical, downwardly and inwardly tapering central open region 44 shown in FIG. 6 . Open region 44 could have other constricting shapes, such as an hourglass shape, a reverse conical shape or a staircase or otherwise stepped shape. It may also be possible to make open region with a constant, appropriately small cross-sectional size and thus without a constricted area. The shape of open region 44 may be the result of the deposition process chosen for the deposition of thermal insulator 42 ; the deposition of thermal insulator 42 may also be controlled to result in the desired, typically constricting, shape for open region 44 . Processing steps may be also undertaken after deposition of thermal insulator 42 to create the desired shape for open region 44 . FIG. 7 illustrates a result of depositing a phase change material 46 within central open region 44 , followed by chemical mechanical polishing to create a surface 47 . Phase change material 46 is thermally insulated from layer 38 by thermal insulator 42 . The downwardly and inwardly tapering shape of thermal insulator 42 creates a narrow transition region 48 of change material 46 to create a phase change element 49 at region 48 . Phase change material 46 is typically about 130 nm wide at surface 47 and about 30 to 70 nm, typically about 50 nm, at transition region 48 .
Both the smaller size of phase change element 49 at transition region 48 and the use of thermal insulator 42 reduce the current needed to cause a change between a lower resistivity, generally crystalline state and a higher resistivity, generally amorphous state for phase change element 49 .
FIG. 8 illustrates the results of TiN deposition and chemical mechanical polishing to create a second electrode layer 50 having a planarized surface 52 . Lithographic mask 54 is shown in FIG. 9 positioned overlying first and second plugs 20 , 22 and their associated thermal insulators 42 and phase change materials 46 . FIG. 10 illustrates the results of etching steps in which portions of second electrode layer 50 , silicon dioxide layer 38 and first electrode layer 34 not covered by mask 54 are removed using appropriate etching recipes according to the composition of the layers to create etched regions 56 and first and second electrodes 57 , 59 . Lithographic mask 54 is sized so that portions 61 of inter-electrode layer 38 are left surrounding thermal insulators 42 after the etching steps of FIG. 10 to prevent etching of thermal insulator 42 , which could be caused by conventional tolerances associated with conventional manufacturing steps.
FIG. 11 illustrates the results of an oxide fill-in step in which an fill 58 , such as silicon dioxide, is deposited within etched regions 56 , reconstituting the inter-electrode layer 48 and filling between the memory cells, and followed by CMP to create planarized surface 60 . Thereafter, an electrically conductive material 62 is deposited on surface 60 to create phase change memory device 10 , including memory cells 64 , shown in FIG. 1 . Electrically conductive material 62 is typically copper or aluminum, but it also may be tungsten, titanium nitride or other materials and combinations of materials.
Electrodes 57 , 59 in the illustrated embodiments are preferably TiN. Although other materials, such as TaN, TiAlN or TaAlN, may be used for electrodes 57 , 59 , TiN is presently preferred because it makes good contact with GST (discussed below) as phase change material 46 , it is a common material used in semiconductor manufacturing, and it provides a good diffusion barrier at the higher temperatures at which phase change material 46 transitions, typically in the 600-700° C. range. Plugs 20 , 22 and common source line 24 are typically made of tungsten.
Embodiments of the memory cell include phase change based memory materials, including chalcogenide based materials and other materials, for phase change material 46 . Chalcogens include any of the four elements oxygen (O), sulfur (S), selenium (Se), and tellurium (Te), forming part of group VI of the periodic table. Chalcogenides comprise compounds of a chalcogen with a more electropositive element or radical. Chalcogenide alloys comprise combinations of chalcogenides with other materials such as transition metals. A chalcogenide alloy usually contains one or more elements from column six of the periodic table of elements, such as germanium (Ge) and tin (Sn). Often, chalcogenide alloys include combinations including one or more of antimony (Sb), gallium (Ga), indium (In), and silver (Ag). Many phase change based memory materials have been described in technical literature, including alloys of: Ga/Sb, In/Sb, In/Se, Sb/Te, Ge/Te, Ge/Sb/Te, In/Sb/Te, Ga/Se/Te, Sn/Sb/Te, In/Sb/Ge, Ag/In/Sb/Te, Ge/Sn/Sb/Te, Ge/Sb/Se/Te and Te/Ge/Sb/S. In the family of Ge/Sb/Te alloys, a wide range of alloy compositions may be workable. The compositions can be characterized as TeaGebSb100-(a+b).
One researcher has described the most useful alloys as having an average concentration of Te in the deposited materials well below 70%, typically below about 60% and ranged in general from as low as about 23% up to about 58% Te and most preferably about 48% to 58% Te. Concentrations of Ge were above about 5% and ranged from a low of about 8% to about 30% average in the material, remaining generally below 50%. Most preferably, concentrations of Ge ranged from about 8% to about 40%. The remainder of the principal constituent elements in this composition was Sb. These percentages are atomic percentages that total 100% of the atoms of the constituent elements. (Ovshinsky '112 patent, columns 10-11.) Particular alloys evaluated by another researcher include Ge 2 Sb 2 Te 5 , GeSb 2 Te 4 and GeSb 4 Te 7 . (Noboru Yamada, “Potential of Ge—Sb—Te Phase-Change Optical Disks for High-Data-Rate Recording” , SPIE v. 3109, pp. 28-37 (1997).) More generally, a transition metal such as chromium (Cr), iron (Fe), nickel (Ni), niobium (Nb), palladium (Pd), platinum (Pt) and mixtures or alloys thereof may be combined with Ge/Sb/Te to form a phase change alloy that has programmable resistive properties. Specific examples of memory materials that may be useful are given in Ovshinsky '112 at columns 11-13, which examples are hereby incorporated by reference.
Phase change alloys are capable of being switched between a first structural state in which the material is in a generally amorphous solid phase, and a second structural state in which the material is in a generally crystalline solid phase in its local order in the active channel region of the cell. These alloys are at least bistable. The term amorphous is used to refer to a relatively less ordered structure, more disordered than a single crystal, which has the detectable characteristics such as higher electrical resistivity than the crystalline phase. The term crystalline is used to refer to a relatively more ordered structure, more ordered than in an amorphous structure, which has detectable characteristics such as lower electrical resistivity than the amorphous phase. Typically, phase change materials may be electrically switched between different detectable states of local order across the spectrum between completely amorphous and completely crystalline states. Other material characteristics affected by the change between amorphous and crystalline phases include atomic order, free electron density and activation energy. The material may be switched either into different solid phases or into mixtures of two or more solid phases, providing a gray scale between completely amorphous and completely crystalline states. The electrical properties in the material may vary accordingly.
Phase change alloys can be changed from one phase state to another by application of electrical pulses. It has been observed that a shorter, higher amplitude pulse tends to change the phase change material to a generally amorphous state. A longer, lower amplitude pulse tends to change the phase change material to a generally crystalline state. The energy in a shorter, higher amplitude pulse is high enough to allow for bonds of the crystalline structure to be broken and short enough to prevent the atoms from realigning into a crystalline state. Appropriate profiles for pulses can be determined, without undue experimentation, specifically adapted to a particular phase change alloy. A material useful for implementation of a PCRAM described herein is Ge 2 Sb 2 Te 5 , commonly referred to as GST. Other types of phase change materials can also be used.
Other programmable resistive materials may be used in other embodiments of the invention, including N 2 doped GST, Ge x Sb y , or other material that uses different crystal phase changes to determine resistance; Pr x Ca y MnO 3 , PrSrMnO, ZrOx, or other material that uses an electrical pulse to change the resistance state; 7,7,8,8-tetracyanoquinodimethane (TCNQ), methanofullerene 6,6-phenyl C61-butyric acid methyl ester (PCBM), TCNQ-PCBM, Cu-TCNQ, Ag-TCNQ, C60-TCNQ, TCNQ doped with other metal, or any other polymer material that has bistable or multi-stable resistance state controlled by an electrical pulse. For example, another type of memory material that in some situations may be appropriate is a variable resistance ultra thin oxide layer.
For additional information on the manufacture, component materials, use and operation of phase change random access memory devices, see U.S. patent application Ser. No. 11/155,067, filed 17 Jun. 2005, entitled Thin Film Fuse Phase Change Ram And Manufacturing Method.
The invention has been described with reference to phase change materials. However, other memory materials, also sometimes referred to as programmable materials, can also be used. As used in this application, memory materials are those materials having electrical properties that can be changed by the application of energy; the change can be a stepwise change or a continuous change or a combination thereof.
The above descriptions may have used terms such as above, below, top, bottom, over, under, et cetera. These terms are used to aid understanding of the invention are not used in a limiting sense.
While the present invention is disclosed by reference to the preferred embodiments and examples detailed above, it is to be understood that these examples are intended in an illustrative rather than in a limiting sense. It is contemplated that modifications and combinations will occur to those skilled in the art, which modifications and combinations will be within the spirit of the invention and the scope of the following claims.
Any and all patents, patent applications and printed publications referred to above are hereby incorporated by reference. | 4y
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[0001] The present application claims priority from U.S. provisional patent application 61/376,845 filed Aug. 25, 2010 and non-provisional patent application Ser. No. 12/971,505 filed Dec. 17, 2010.
BACKGROUND
Field
[0002] The present invention relates to a melt-extrudable thermoplastic composition and to the preparation of nonwoven webs. The composition described is a non-woven fiber web made of a mono-component, mono-constituent polylactic acid (PLA) and more particularly made of PLA of a plurality of layers and having fibers with cross-sections in various structural configurations.
[0003] As beverage fabrics presented in Noda (2002/0143116), Rose (203/0113411), Jordan (2005/0136155) as well as Ser. No. 12/971,505 have been produced there is still a need for improvement.
[0004] In the United States, a cup of coffee is generally produced under atmospheric pressure with hot water flowing through the coffee grounds and through a filter. The resultant coffee is coloring the water from light grey to black, but still maintains a clarity. In Europe as well as most of the rest of the world, coffee is generally produced under a pressure greater than 1 atmosphere and the coffee is generally ground to finer particles. As a result, coffee is cloudy, stronger and has a “crema” or foam on the surface. Such coffee is sipped slowly to enjoy the enhanced flavor.
[0005] In all cases, there is a need for a tortuous path for the water to flow through a filter that will allow a fast flow, but preventing any particles from flowing into the cup. It is believed that a tortuous path will allow more complete transfer of the coffee essence from the grounds to the liquid, while at the same time increasing the “crema”.
[0006] Cellulosic “paper” products have an inverse relationship of weight with porosity. As cellulosic papers get higher than 30 gsm in weight, there porosity goes to zero and become impermeable. Further cellulose fibers swell on contact with water, further closing the pores of the paper.
[0007] Therefore a need exists for improvement to the Ser. No. 12/971,505 invention.
[0008] There is also a need for an infusion substrate, particularly for tea and coffee, which provides rapid infusion of hot water into the tea or coffee particles, while being strong enough to keep the particles within a bag or pouch made up in substantial part or wholly of such substrate. There is also a need for heat-sealable pouch for tobacco and tobacco products (i.e. snuff and chewing tobacco).
[0009] Further, it is highly desirable that the substrate media be 100% bio-degradable and not contain any inert or non-biodegradable components.
[0010] Further, it is highly desirable that the media, including all of the production scrap, be recyclable into itself.
[0011] Significant development of Polylactic Acid (PLA) fiber was conducted by Cargill Inc. to make fibers from natural raw materials and resultant process and products are described in U.S. Pat. No. 6,506,873.
[0012] Kimberly Clark mentions PLA in its U.S. Pat. No. 7,700,500, “Durable hydrophilic treatment for biodegradable polymer substrate.”
[0013] U.S. Pat. No. 6,510,949 by Grauer et al teaches that hydrophilic substances may be impregnated, into filter paper to improve the water-wet ability and water absorption.
[0014] Tea bags and coffee pouches traditionally have been made of paper and teabags suffer from slow infusion times and tend to float on the liquid surface.
[0015] A new tea bag fabric from Japan has been made using a nylon knitted mesh, which provides rapid infusion, but requires a non-traditional sealing method, are expensive and are not biodegradable.
[0016] Attempts have been made to produce a spun melt nonwoven from PL A, but it suffers from poor sealability and performance in automated packing machines.
SUMMARY
[0017] The present invention provides a highly porous media of web form, divisible and fabricated into end product components (e.g. bags, pouches) or portions of the same that is produced from PLA, alone or with Co-PLA fibers, using a thermo bonded nonwoven manufacturing method. The media exhibits high efficiency for infusion of hot water into the coffee or tea (or other liquid as more broadly indicated above). The use of Synthetic Cellulosic fibers blended with proprietary PLA formula is disclosed.
[0018] The fibers self bond at many cross over points through web heating and/or pressure applications in initial web production and/or subsequent steps. Disclosed is a melt-extruded thermoplastic non-woven web composition consisting of: a plurality of fiber layers made from a plurality of fibers that are blends of mono-component, mono-constituent polylactic acid (PLA) fibers.
[0019] The polylactic acid (PLA) fiber have different deniers and blend percentages of high and low fibers having a melt flow temperature in a range of 145-175° C. and 105-165° C., respectively. Various layer combinations and sequences are also provided for within the purview of the invention.
[0020] The present invention also provides a highly porous media of web form, divisible and fabricatable into end product components (e.g. bags, pouches) or portions of the same that is produced from PLA, alone or with Co-PLA fibers, using a thermo bonded nonwoven manufacturing method. The media exhibits high efficiency for infusion of hot water into the coffee or tea (or other liquid as more broadly indicated above). The fibers self bond at many cross over points through web heating and/or pressure applications in initial web production and/or subsequent steps.
[0021] The web material of the invention is produced in a continual process that provides for controllable machine processing direction and cross machine direction properties that enhance the performance of the media. By controlling the % of the lower melt Co-PLA in an intimate blend of PLA and Co-PLA fibers, the thermo bonding strength can be controlled during web manufacture by fiber orientation, temperature setting, and time of exposure to heat. During bag or pouch manufacture, the strength of the sealing bond can be controlled by temperature, dwell time, and knife pressure.
[0022] PLA and Co-PLA have specific gravity of 1.25, i.e. greater than water, which causes the bag or pouch to sink and to be submerged and be totally engulfed in the hot water. Further, PLA is naturally hydrophilic, without special treatment, which allows the water to flow quickly into the tea or coffee.
[0023] The Co-PLA can be chosen with a melt point from 125° C. to 160° C. by varying the isomer content of the polymer. Thus it is possible to address the sealing requirements of various automated packaging machines.
[0024] Not only is the media made from a renewable raw material, but the scrap fiber, nonwoven trim scrap, and the bag making scrap can be remelted, extruded into a pellet, and blended into the extrusion operation to make more fiber. It is from 100% renewable source and it is 100% recyclable. During the fiber manufacturing process, any “waste” fiber may be re-extruded into pellets and put back into the fiber process. During the nonwoven web production process, any startup or trim “waste” may be re-extruded into pellets and put back into the fiber process. During the infusion package manufacturing process, any trim, start-up, or other web “waste” may be re-extruded and put back into the fiber manufacture process.
[0025] Unlike PET, nylon, and most papers, which contain latexes and synthetic fillers, the media of the present invention is 100% compostable. After hydrolysis at 98% humidity and 60 C or higher, PLA is readily consumed by microbes and its component atoms are converted for possible re-use in growing more corn, beets, rice or etc. for future conversion to PLA.
[0026] The invention was produced in three weights: 16, 18 and 20 gsm (grams per square meter, but could be produced in a lighter or heavier weight).
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] FIGS. 1A-1I illustrate embodiments of fiber shapes that utilize the teachings of the present invention;
[0028] FIGS. 2A-2I illustrate one embodiments of layers;
[0029] FIG. 3 illustrates three different fibers. Large diameter, smaller diameter and low melt forming fused bond points at 4× magnification;
[0030] FIG. 4 illustrates another view of FIG. 3 at 10× magnification showing low melt bond points and that the low melt fiber ceases to be a fiber;
[0031] FIG. 5 is photomicroscope slide ( 1 ) at 40× magnification power showing an 18 gsm web with 30% (by weight) co-PLA/70% PLA which exhibited excellent strength and superb sealing characteristics. It should perform equally well at lighter weights from 12 to 20 gram per square meter (gsm);
[0032] FIG. 6 is photomicroscope slide ( 2 ) showing an 16 gsm web with 10% co-PLA/90% PLA blend, which exhibited adequate strength but did not have enough low melt fiber to seal effectively;
[0033] FIG. 7 is a drawing of a bi-component fiber with a high melt core (PLA @ 175° CM) and a low-melt sheath (Co-PLA @ 135° C.);
[0034] FIG. 8 is a Microscope slide of 85/15% blend at 18 gsm-40 power;
[0035] FIG. 9 is a Microscope slide of 80/20% blend at 18 gsm-40 power;
[0036] FIG. 10 is a microscope slide of 80/20% blend at 18 gsm-100 power;
[0037] FIG. 11 is a microscope slide of standard paper; and;
[0038] FIG. 12 is a microscope slide of a Japanese made nylon fabric, and FIG. 13 is Table I showing a comparison of paper airflow with PLA airflow and Graph A showing the relationship of breathability properties to GSM.
DETAILED DESCRIPTION
[0039] Nonwoven webs are porous, textile-like materials which are composed primarily or entirely of fibers assembled in flat sheet form. The tensile properties of such webs may depend on frictional forces or on a film-forming polymeric additive functioning as a binder. All or some of the fibers may be welded to adjacent fibers by a solvent or by the application of heat and pressure.
[0040] Nonwoven webs currently are employed in a variety of products such as diapers, napkins, sterilization wraps; medical drapes, such as surgical drapes and related items; medical garments, such as hospital gowns, shoe covers, and the like to name but a few. The nonwoven webs can be utilized as a single layer or as a component of a multilayered laminate or composite. When a multilayered laminate or composite is present, often each layer is a nonwoven web. Such multilayered structures are particularly useful for providing improved performance in strength properties.
[0041] In order to improve the performance of a nonwoven-containing product, it sometimes is necessary to modify certain characteristics of the fibers of which the web is composed. A classic example is the modification of the hydrophobicity of fibers by a topical treatment of the web with a surfactant or through the use of a melt additive.
[0042] The use of a topical treatment or melt additive has the draw back when the non-woven is used in the food industry or related to contact with human skin or human digestion. The present invention avoids the use of such surfactants and topical treatments and provides additional unexpected results.
[0043] The diameter of fibers will affect the nesting or stacking of the fibers during web formation. Further, the percentage of low melt fibers will affect the density and porosity of the web.
[0044] The ability to produce a web with multiple layers presents the ability to create webs of different porosity, thickness, and stiffness. Webs were produced with three layers A B A. All fibers were mono-component, mono-constituent PLA.
[0045] It is within the purview of this invention that different layers, depending on the embodiment, contain different diameters, different ratios of high & low melt, and different shapes as well as the weight of each layer.
[0046] The A layers were produced with 50% 1.5 d×2″ High Melt (170° C.) PLA (PS 2650) and 50% 2.5 d×2″ Low Melt (130° C.) co-PLA (PS1801).
[0047] The B layer (in the center) was produced with 75% 2.5 d×2″ High melt (170° C.) PLA (PS2650) and 25% 2.5 d×2″ Low melt (130° C.) Co-PLA (PS1801). Note that B has 2.5 d vs. 1.5 d high melt fibers which are about 2.5× greater in diameter and only 25% vs. 50% of the low melt.
[0048] The fibers were blended separately and then fed into the card feeders. All cards were Hergerth 3 m wide roller cards with randomizing rolls. The first two cards produced the A layer and fed the layer onto a collecting apron. The next two cards produced the B layer and it onto the apron on top of the A layer. The final 2 cards produced the A layer and fed it onto the same apron on top of the B layer, creating a single web of A B A layers.
[0049] The collective web was then delivered to a heated two roll calendar machine with the rolls heated by Hot Oil to a temperature of 150° C.
[0050] The fabric weight was adjusted between 80 to 120 grams per square meter and a weight of 90 grams per square meter was chosen as having the best properties.
[0051] The stiffness improved to fit the Senseo® brewing machines and produce an excellent cup of coffee without leaking around the edges.
[0052] The porosity of the 90 gsm ABA web was tested against other weights of mono-component, mono-constituent PLA webs ranging from 16 to 90 gsm. The porosity was measured with a Frazer® air-permeometer and measured in liters/m 2 /second. Industry standard webs made from cellulose with either a Polyethylene or PLA bi-component fiber at 30% were compared by weight in the following table and graph:
[0053] The net effect is that a 90 gsm web was obtained with excellent airflow or permeability, but the cellulosic web had virtually no airflow.
[0054] Up to this point, only round, solid fibers of mono-component, mono-constituent PLA fibers were used.
[0055] Fibers made in other shapes were investigated. The shapes included a triangle, mock hollow or “C” shaped, and ribbon or flat. (See FIGS. 2A-2I ).
[0056] These fibers were produced in the same manner as round. The molten polymer (PLA) was pumped by a metering pump through a metal spinneret. (Note: The low melt Co-PLA was not produced (but could be in the future) as they would melt, flow, and lose their shape). The fibers were air quenched and then drawn at their Tg of 60° C. at a ratio of 3.5:1 to obtain desired crystallinity. The fibers were crimped, heat set and cut to length.
[0057] It was found that these shaped fibers do not affect the air flow, but improve the “crema” or foam in the finished cup of coffee.
[0058] It was also learned that blending in synthetic cellulosic fibers, such as rayon, acetate, or Lyocell (Tencel®) solved a problem of heat effect on coffee and tea bag formation. Tencel® (generic name Lyocell) is a sustainable fabric regenerated from wood cellulose. Lyocell regenerated cellulose fiber is made from dissolving pulp (bleached wood pulp). It was developed and first manufactured for market development as Tencel® in the 1980s by Courtaulds Fibres. Standard forming machines (such as IMA or Cloud) do not have adequate heat controls to maintain a precise temperature over a wide range of running speeds. Hence, there were times when the mono-component, mono-constituent PLA fibers would melt, creating flaws in the pouch or pad.
[0059] By blending in from 5 to 60% of the synthetic cellulosic fibers with the high and low melt PLA, there was a greater temperature range for pad formation available. Tencel® was found to be the easiest to blend with the PLA fibers. The net result was a fabric with higher strength at the melting point of the high melt PLA. While blending in the synthetic cellulose fibers negated the recyclability attribute, the end product was still suitable for tea and coffee pads, bags, or pouches. The fabric was still biodegradable and since Tencel® has a specific gravity compared to 1.24 for PLA, the blended fabric had equal or better ability to sink in the cup rather than float.
[0060] Finally, hydrophilic finishes or lubricants were applied to the fibers during fiber production. These finishes were provided by Goulston Technologies, Inc. of Monroe N.C. These finishes were designed to meet FDA and German BfR requirements for food quality. Goulston finishes such as PS-11473, PS-10832, and PS 12062 were tried. All were heat set at 130° C. during the fiber production process to thoroughly bond them to the fibers. The heat-setting bonded the finishes so that they were not released into the boiling water (100-110° C.) used for Tea Bags, coffee pads, or other pouches.
[0061] The water flow appeared to improve as the color of the water darkened at a much faster rate than PLA fibers made only with an anti-stat such as Goulston AS-23. These finishes were totally compatible to provide excellent carding and fabric formation. The hydrophilic properties and the 1.24 specific gravity of PLA, resulted in bags that would sink and wet out easily, resulting in a faster brew cycle.
[0062] Another advantage of the invention is that since the pouch or bag is hydrophilic it sinks. This advantage is seen in a tea or coffee bag where most paper or other bags float on the top and give minimal diffusion of the coffee or tea contents. By having the bag sink diffusion of the contents is further given. Another advantage is as the non-woven web is exposed to water, it becomes clearer showing the contents of the bag or pouch. The bag or pouch has the benefits of using less contents such as coffee or tea leafs to accomplish the same strength of beverage. In addition diffusion time is decreased since the pore size is relatively maintained using the mono-component fiber. This invention is not limited to beverage pouches and can be utilized in any application that requires diffusion of contents through a pouch or bag. The advantages of biodegradation, recyclability, decreased amount of contents needed, decreased diffusion time, and clarity of the pouch is all realized in the present invention.
[0063] In view of the disclosed description, it will now be apparent to those skilled in the art that other embodiments, improvements, details, and uses can be made consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent, which is limited only by the following claims, construed in accordance with the patent law, including the doctrine of equivalents.
[0064] A preferred embodiment of the invention was made, and is explained as follows, including all or most of its fibers in bi-component form and its production of mono-component PLA fiber made from Fiber Innovation Technologies (Type T811) was blended with core/sheath bi-component (BiCo) fibers with PLA in the Core and Co-PLA in the sheath. The core/sheath area ratio was 50/50%. Fibers were produced with a ratio between 80/20% and 20/80%. Other fiber producers such as Palmetto Synthetics and Foss Manufacturing Company can make these fibers. PLA fibers typically are made using lactic acid as the starting material for polymer manufacture. The lactic acid comes from fermenting various sources of natural sugars. These sugars can come from annually renewable agricultural crops such as corn or sugar beets. The polymer must be completely dried prior to extrusion to avoid hydrolysis. PLA is an aliphatic polyester and the helical nature of the PLA molecule makes it easier to crystallize than PET. The PLA can be extruded into a fiber using standard PET fiber equipment.
[0065] In the case of the mono-component PLA fiber, the high temperature variant with a melt temperature of 175° C. is extruded into a fiber. The initial fiber is then drawn 3.5 times its length to get to the required 1.5 denier. It is then crimped and heat set to 140° C. to improve the crystallinity and stabilize the crimp. It is then cut to 1.5″ (38 mm). In the case of the Bi-CO fiber, a melt spinning line using the co-extrusion spinerettes made by Hills Inc, of Melbourne Fla. was used. The spinerettes of the line produced a fiber similar to FIG. 3 . The higher melting (175° C.) PLA is in the core, while the lower melting Co-PLA (135° C.) is in the sheath. Generally, the low melt Co-PLA is fully amorphous, which makes it easier to melt and flow around the crystalline mono-component PLA fibers. The core PLA fiber remains and combines with (bonds to) the mono-PLA fiber at many cross-over points in the web for strength. A web comprising PLA fibers has two different melting points, 145 C-175 C and 105 C-165 C, respectively. The PLA fibers have a melting (softening) point of 145 C to 175 C and the Co-PLA fiber, mono-component is CoPLA with a melt temperature from 105 C to 165 C.
[0066] The blend percentages were varied from 90% PLA/10% BiCo to 60% PLA/40% BiCo. The 70/30% produced the best fabric for strength and sealability. It is also possible to make a blend of crystalline PLA (175° C. melt point) and a mono-component fiber made from 100% Co-PLA (melt point between 135° and 165° C.) Blending is performed by weighing out the desired percentages of PLA and BiCo fibers either manually or with automated weigh feeders. The two fibers are layered on top of each other and fed into an opener which has feed rolls, feeding the fibers into a cylinder with teeth that pulls the clumps into individual fibers. The fibers are then blown into a blending bin to create a homogeneous mixture by first layering the fibers uniformly in the bin and then cross-cutting the layers with a spiked apron which feeds the fibers to a carding system.
[0067] The carding system consists of two feeding hoppers. The first acts as a reserve holding bin to ensure continuous supply. The second feeding hopper has a continuous scale with a load cell that provides a set weight feed to the card. The card is a series of interacting cylinders covered with toothed wire that tears and combs the fibers into a parallel web.
[0068] The fabric weights were varied from 12 to 20 gsm, with the 18 gsm chosen for testing. It is believed that the 16 gsm (not run) will provide the best characteristics.
[0069] The production line was a Asselin-Thibeau line with 3 carding machines, each 2.3 meters wide. The web was run in a straight line and fed into a calendar with 460 mm diameter rolls heat with thermal oil at a temperature of 130° C. to 152° C. Line speeds were 40 meters per minute at a finished width of 2.0 meters.
[0070] If a parallel web is desired, the fibers coming straight out of the carding system are combined with the other two cards and thermo-bonded. This generally results in a Machine Direction (MD)/Cross Machine Direction (CMD) strength ratio of 4:1. If a more balanced strength ratio is desired then a “randomizer” roll system may be added to one or more cards. The result can be MD/CMD strength ratio up to 1.5:1.
[0071] By controlling the carding system and fiber orientation, the fibers can be aligned in a manner to control the apertures or openings in the web to enhance rapid infusion of the hot water.
[0072] The rolls were slit to a width of 156 mm (6.14″) for the Tea Bag machine.
[0073] The tea bag machine was a model ASK020 made by Miflex Masz. Two rolls were placed on the machine and centered on the mold. The correct amount of tea was deposited and the top and bottom sheet sealed automatically at a temperature of 135 C with a dwell time between 0.5 and 0.8 seconds,
[0074] The present invention cuts easily on standard tea/coffee packaging machines with a simple knife device and creates minimal amount of lint or loose fibers.
[0075] The web maintains its pore size during the infusion with hot liquids because the fibers do not swell. This enhances to flow of water into the tea or coffee, reducing the brewing time.
[0076] Because the web fibers do not swell, the risk of gas pressure build up is eliminated and thus the risk of bag breakage and particle dispersion is eliminated.
[0077] Using boiling water, the infusion time is reduced to one (1) minute
[0078] When pressed, the infusion liquid completely leaves the container (bag or pouch), leaving a silky, translucent surface.
[0079] Recycling of PLA is very easy, a depend on the place in the process. During fiber manufacture, all of the fibers from both spinning and drawing can be re-extruded to pellets by densifying the fiber scrap using an “Erema” or “Mechanic Moderne” recycling line (There are many others that will also work). The equipment will density the fibers and partially melt them to pre-dry to drive off any moisture. The dense particles are forced into a vented extruded to remove all of the moisture. The PLA is then fully melted and extruded and filtered to form pure amorphous pellets. The pellets can then be blended with virgin pellets to make new fiber. During the Thermo-Bond process, scrap fiber, edge trim, and defective fabric can be baled and shipped back to the recycling system described above. During the Tea-Bag process, the trimming scrap and “skeleton” scrap, especially from making round pouches, can be baled and reprocessed as described above. Finally, the tea bags can be composted after use and the PLA will turn back into sugars which can be used to make more PLA.
[0080] The present invention may also be used as pouches for: lemonade, herbal sachets, soap powder, chemicals and chlorine for pools and spas, decontaminating liquids, coloring of liquids, dehumidifying chemicals, carriers for phase-change materials for heating or cooling, tobacco pouches, and all materials that can be placed in a heat/ultra sound activated scalable container,
[0081] A further preferred embodiment comprises a tea bag material and end product made in whole or in part of a mono-component fiber with self bonding property to similar fibers or other to produce effective web material and effective end product.
[0082] A preferred mono-component is co-PLA with a melt temperature of 135° C. Such a fiber was produced in a 1.3 denier×38 mm fiber. This produced a fiber which is 100% binder as opposed to a bi-component fiber, generally consisting of 50/50 PLA/Co-PLA. The Mono-component fiber was blended with standard PLA fiber in a ratio of 85% PLA/15% CoPLA. The blend was processed on a carded web line at 18 and 20 gsm. The result was a significantly stronger web than that produced with the bi-component fiber. The web was clearer and less opaque than the one with the Bi-co fiber. This is a very desirable attribute.
[0083] In a second trial, the mono-component Co-PLA fiber was blended with the type 811 PLA fibers in a ratio of 80/20%. The web was produced in a weight of 18 and 20 gsm. The strength increased and the fabric was less opaque or more translucent. Rolls of both of the types were then slit to appropriate widths and processed on tea bag machines. A further advantage was that the PLA/CoPLA blend absorbed less water that the standard paper. While both the PLA and Standard paper weighed 18 gsm dry, the PLA reached 90 gsm when fully saturated with water, while the standard paper reached 200 gsm.
[0084] A first trial was on a Fuso machine replacing an expensive nylon fabric. The tea bags formed well and the seams were stronger than those made with the nylon fabric. The 18 gsm with the 80/20 blend provided the best results.
[0085] To improve strength, uniformity, and fiber distribution, one of the carding machines (out of 5) was modified by placing a randomizing unit on the doffer or take off rolls. On a standard card machine, the fiber orientation is generally 5:1 in the machine versus cross machine direction and can be optimized to 3.5:1. With the randomizing rolls, the orientation is about 1.5:1 for the card with the randomizer. The resultant composite web had an orientation of between 2:1 and 3:1. This was a significant improvement. The resultant webs showed no degradation of strength during wet conditions that standard tea bag paper exhibits.
[0086] It will now be apparent to those skilled in the art that other embodiments, improvements, details, and uses can be made consistent with the letter and spirit of the foregoing disclosure and within the scope of this patent, which is limited only by the following claims, construed in accordance with the patent law, including the doctrine of equivalents. | 4y
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FIELD OF THE INVENTION
The present invention is related generally to power conversion arrangement and method and, more particularly, to thermal dissipation improvement in an arrangement for power conversion.
BACKGROUND OF THE INVENTION
FIG. 1 shows a low dropout (LDO) regulator 10 , which is a linear regulator and is capable of converting an input voltage VIN to be a supply voltage VOUT if it is enabled by an enable signal ENABLE. FIG. 2 shows a circuit diagram of a typical LDO regulator 10 , which comprises a transistor 14 connected between an input voltage VIN and the regulator output VOUT, two resistors R 1 and R 2 connected between the regulator output VOUT and ground GND to serve as a voltage divider to divide the supply voltage VOUT to generate a feedback voltage VFB, and an amplifier 12 to control the transistor 14 in response to the difference between the feedback voltage VFB and a reference voltage Vref, so as to maintain the supply voltage VOUT at a desired value. However, when the LDO regulator 10 operates in high current condition, due to its poor thermal dissipation, the LDO regulator 10 is usually operated with degraded performance, and even damaged.
To improve the over thermal condition, FIG. 3 shows an ideal solution, which uses two common-output LDO regulators 20 and 22 to equally share the loading current I. Since each of the LDO regulators 20 and 22 operates with only half of the loading current I, the power dissipation is shared to them, and the thermal dissipation in each of them is reduced. In practice, however, even if the LDO regulators 20 and 22 are produced by the same manufacturing process or produced in the same batch, they may generate different output voltages. For example, 3V is the supply voltage VOUT the designer desires each of the LDO regulators 20 and 22 to generate, while actually, the LDO regulator 20 may generate a deviated one, for example 3V+1% or 3.03V, and the LDO regulator 22 may generate another one, for example 3V−1% or 2.97V. In this case, because the regulated voltage provided by the LDO regulator 22 is lower than that by the LDO regulator 20 , the LDO regulator 22 will not work when the power supply arrangement of FIG. 3 operates, and as a result, the loading current I will be supplied by the LDO regulator 20 alone. Therefore, this approach will not really improve the thermal dissipation and the performance.
Therefore, it is desired a power supply arrangement and a control method thereof which really share the thermal dissipation by multiple linear regulators.
SUMMARY OF THE INVENTION
An object of the present invention is directed to the thermal dissipation improvement of a power supply arrangement having multiple linear regulators.
According to the present invention, time-sharing technique is used for power conversion to improve the thermal dissipation thereof. Preferably, a power supply arrangement comprises a plurality of common-output linear regulators, and a time-sharing control scheme is employed in serial or parallel manner to enable the linear regulators in turn to convert an input voltage to a supply voltage. Preferably, a clock is used for the time-sharing control to enable the linear regulators. Since each time only one of the linear regulators is enabled for generate the regulated output voltage, the whole thermal dissipation for the power conversion is shared to the linear regulators, and each of the linear regulators suffers only a less thermal dissipation.
BRIEF DESCRIPTION OF DRAWINGS
These and other objects, features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings, in which:
FIG. 1 shows a LDO regulator;
FIG. 2 shows a circuit diagram of a typical LDO regulator;
FIG. 3 shows an ideal solution for thermal dissipation issue by using multiple LDO regulators;
FIG. 4 shows a first embodiment according to the present invention;
FIG. 5 shows a second embodiment according to the present invention; and
FIG. 6 shows a third embodiment according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
As shown in FIG. 4 , a power supply arrangement 30 comprises two common-output LDO regulators 32 and 34 , each of which can individually convert the input voltage VIN to a supply voltage VOUT. However, a switch circuit 36 is further provided to enable the LDO regulators 32 and 34 with a clock CLK. The clock CLK is connected to the enable input EN of the LDO regulator 32 directly, and to the enable input EN of the LDO regulator 34 through an inverter 38 . When the clock CLK is logical high, the LDO regulator 32 is enabled by the clock CLK, and thus it converts the input voltage VIN to the supply voltage VOUT. In this phase, the LDO regulator 34 is disabled because of the inverter 38 . When the clock CLK changes to logical low, the low LDO regulator 32 is disenabled, and the LDO regulator 34 is enabled instead, to convert the input voltage VIN to the supply voltage VOUT. As such, each time only one of the LDO regulators 32 and 34 is enabled, and the LDO regulators 32 and 34 are switched by turns, the heat generated in the power supply arrangement 30 is shared by the LDO regulators 32 and 34 . Further, at any time only one of the LDO regulators 32 and 34 operates to supply the regulated voltage VOUT, so that there is no need to worry about the voltage generated by one of the LDO regulators 32 and 34 will be higher than that by the other one.
FIG. 5 shows a second embodiment according to the present invention. In a power supply arrangement 40 , a plurality of common-output LDO regulators 42 are alternatively switched by a switch circuit 44 . All the enable pins EN of the LDO regulators 42 are parallel connected to the switch circuit 44 , and the switch circuit 44 uses a time-sharing multiplexer 46 to switch between the LDO regulators 42 by turns. Each time only one of the LDO regulators 42 will be enabled to convert the input voltage VIN to the supply voltage VOUT, and therefore the heat generated in the power supply arrangement 40 is shared by the LDO regulators 42 , without causing any output deviation issue.
In a power supply arrangement 50 shown in FIG. 6 , common-output LDO regulators 52 , 54 , 56 and 58 are connected in a ring, in such a manner that each of the LDO regulator 52 , 54 , 56 and 58 provides the enable signal for the next stage. When the first LDO regulator 52 is enabled, it converts the input voltage VIN to the supply voltage VOUT, and the other LDO regulators 54 , 56 and 58 are disabled. After operating for a time period, the first LDO regulator 52 disables itself and provides an enable signal EN 1 to enable the second LDO regulator 54 . Similarly, after operating for a time period, the second LDO regulator 54 disables itself and provides an enable signal EN 2 to enable the third LDO regulator 56 , and then after operating for a time period, the third LDO regulator 56 disables itself and provides an enable signal EN 3 to enable the fourth LDO regulator 58 , and then after operating for a time period, the fourth LDO regulator 58 disables itself and provides an enable signal EN 4 to enable the first LDO regulator 52 . As such, each time only one of the LDO regulators 52 , 54 , 56 and 58 is enabled to convert the input voltage VIN to the supply voltage VOUT. In other embodiments, the switching between the LDO regulators 52 , 54 , 56 and 58 may be triggered by other parameters, such as temperature. For example, any of the LDO regulators 52 , 54 , 56 or 58 operates until it detects its temperature reaches a certain value, even though its operating time not so long to reach the threshold, it will disable itself and provide the enable signal to enable the next LDO regulator.
While the present invention has been described in conjunction with preferred embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and scope thereof as set forth in the appended claims. | 4y
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BACKGROUND OF THE INVENTION
1. Field of Invention
This invention relates to the field of switching-type battery chargers and specifically to a high power factor battery charger which is suitable for use in charging systems wherein a high output power and relatively small size is necessary.
2. Description of the Prior Art
Switching-type power supplies are noted for their high-efficiency, light weight, and probable long term cost advantages as copper and steel rise in price. Switching-type power supplies are especially useful in applications where heat dissipation and size are important.
Typically, a switching power supply achieves voltage regulation through the use of a solid state switch, such as a transistor, which is gated on or off according to the power requirement of the load. This technique known as duty cycle regulation is quite efficient as power is delivered to the load in proportion to power requirement of the load. The power delivered to the load will then be the average power of the pulse train at the output of the switching device. This technique eliminates the need for bulky and expensive power transformers and large heatsinks required by series pass transistors in an analog charging circuit.
A major problem with conventional switching-type charging circuits arises when circuits are used in high power applications. Switching type charging circuits typically have low-power factors. The power factor of a device describes the relationship of the relative phase of the input current and voltage when excited by an AC voltage and quantifies electrical losses which occur in a capacitive or inductive circuit. The power factor can be thought of as the ratio of the effective series resistance of a device to the complex impedance of the device and is expressed as a percent. A purely resistive device would have a unity power factor. Conventional switching-type charging circuits may have a power factor of 65% due to a widely varying input current demand and the constantly changing input voltage of an AC signal.
The relatively low-power factor of a switching-type battery charger becomes a problem when large amounts of power are required by a load.
As an example, suppose 1,000 watts DC were required from a supply to be operated from a 115 V AC, 15 A service. A typical switching-type charging circuit would run with a conversion efficiency of approximately 85 percent. Therefore, the power demand of this device would be 1,176 W. With a power factor of 65% the volt-ampere input to the device would be 1,809 VA. This translates to an input current of 15.73 amperes or 0.73 amps above the capacity of the supply service. If the power factor of switching device was near unity, the device would draw approximately 10.5 amperes and, therefore, be operable from the intended service.
For the foregoing and other shortcomings and problems, there has been a long-felt need to optimize the power factor of a switching-type charging circuit while maintaining the high efficiency, cool operation and relatively small size of the device.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a switching-type battery charging circuit which can provide a charging current while operating efficiently and maintain a high-power factor.
It is a further object of this invention to provide a switching-type charging circuit which will efficiently accomodate fluctuations in the AC power source line, as well as changing current demands of a load.
It is yet a further object of the present invention to increase the reliability of switching-type charging circuits by eliminating the need for large, expensive electrolytic capacitors.
Briefly described, the invention contemplates a switching-type charging supply which incorporates a dual loop feedback system to optimize the power factor of the circuit. The first feedback loop is responsive to an electronically variable full wave rectified AC voltage reference and a signal related to the level of the current output of the charging circuit for controlling the pulse width modulation circuit. The second feedback loop is responsive to a signal related to the level of the current output of the charging supply, as well as the battery voltage and temperature for controlling the amplitude of the electronically variable voltage reference.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the high power factor switching-type battery charger supply.
FIG. 2 is a graph demonstrating the relationship between the input AC waveform and the waveform used to control the switching transistor used in the charging circuit.
FIG. 3 is a detailed electrical schematic of the circuit of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a block diagram of the preferred embodiment of the present invention. The high-power factor switching-type battery charger supply consists of a conventional pulse width modulation circuit 16 which operates in conjunction with several novel circuits. The circuit is designed to operate from a standard 120 V 60-cycle AC input. The 120 V input signal is connected to a full wave rectifier circuit 10 and a transformer 32. The full wave rectifier circuit 10 provides power for the switching transistor output device 14, and the transformer 32 provides stepped down voltage to generate the sinusoidal voltage reference and power to the remainder of the devices used in this circuit. The output of the full wave bridge circuit 10 is connected to a capacitor 11, an inductor 12 and a capacitor 13 which provide filtering to the output of the full wave bridge circuit 10 which prevents radio frequency signals generated by the switching circuit from entering the AC source line.
The filtered output of the full wave bridge circuit 10 is then connected to the collector of a switching transistor 14. The base of transistor 14 is controlled by the pulse width modulation circuit 16 which will be discussed in more detail later. The pulse width modulated output of transistor 14 is then connected to a resistor 15 and an inductor 18. Inductor 18 acts as an energy storage device which provides a continuous charging current flow to the battery 20 during the "off" cycles of transistor 14. Resistor 15 provides a means of generating a signal related to output current flow for controlling a feedback amplifier 21 responsive to the level of the output charging current. A freewheeling diode 17 is connected between the negative terminal of battery 20 and the junction of resistor 15 and inductor 18. The diode 17 provides protection from inductive impulses created by the overall switching circuit and the load.
Resistor 15 is connected to an amplifier 21 as illustrated which amplifier generates a voltage related to the current level at the output of the charging supply.
The output of amplifier 21 is connected to an input of amplifiers 24 and 23, as shown. Amplifier 24 has a second input which is connected to a variable resistor 31 which provides a rectified sinusoidal voltage reference for the amplifier 24.
The transformer 32 has an output terminal connected to a diode 33. The transformer 32 has a center tap on the output side which is connected to chassis ground. The transformer 32 also has another output terminal connected to a diode 36. Transformer 32 is designed to convert the 120 V input waveform to a 12 V level. Diodes 33 and 36 provide a full wave rectified sinusoidal waveform which is then applied to a photosensitive resistor 28. The photosensitive resistor 28 is then applied through variable resistor 31 to chassis ground.
The output of amplifier 21 is also connected to an input of amplifier 23. A second input of amplifier 23 is connected to a variable resistor 22. Resistor 22 is connected to a circuit 19 which generates a reference voltage related to battery cell voltage and temperature, and this will be discussed in more detail later. The output of amplifier 23 is connected to a resistor 29 and capacitor 30. The capacitor 30 and resistor 29 form a low pass filter which removes high frequency information from the output of amplifier 23 and have the effect of slowing the response time of this feedback loop. Resistor 29 and capacitor 30 are connected to a light emitting diode 27 which has its remote terminal connected to ground.
The photosensitive resistor 28 is responsive to the output of the light emitting diode 27 and has the effect of controlling the amplitude of the positive-going sinusoidal voltage reference developed across resistor 31. The light emitting diode 27 and resistor 28 comprise a device known as an opto-isolator 26 (shown in dotted line) and may be of the type VPH101 available from Vactrol.
The pulse width modulation circuit 16 creates a variable pulse-width signal which is responsive to the voltage output of amplifier 24. A rising voltage at the output of the amplifier 24 has effect of increasing the pulse width at the base of transistor 14.
In operation, the transistor 14 is switched on or off by the pulse-width modulation circuit 16. The pulse-width modulation circuit 16 generates a pulse width in response to the constantly changing AC voltage reference, as well as the current demands of the load. The operating frequency of the pulse-width modulation circuit is approximately 10 kHz and is many times the frequency of the AC input to the circuit. Therefore, at the beginning of the AC cycle, the pulse-width modulation circuit 16 will generate a relatively long duty cycle, and as the AC voltage increases, the duty cycle is shortened. This characteristic has the effect of keeping the current and voltage at the input to the circuit nearly in phase. As the AC input voltage to the circuit rises, more current is available to the switching transistor and, therefore, less "on" time is required by the switching transistor to keep the power to the load constant.
The rectified sinusoidal voltage reference is responsive to the amount of current being delivered by charging circuit to the load. As the battery voltage increases, the current to the light emitting diode 27 is decreased, and the decreased light output causes the resistance of the photosensitive resistor 28 to increase which, in turn, lowers the amplitude of the voltage reference across resistance 31. The lower amplitude of this voltage reference results in a shorter "on" time for the switching transistor 14, thereby reducing the power delivered to the load.
FIG. 2 is a graph depicting the relationship between one-half cycle of the 120 volt AC input waveform and the output of the pulse-width modulation circuit 16. This graph demonstrates a possible waveform which would be generated if the switching-type charging circuit 16 was configured to charge a 48 volt battery. During the initial phase of the AC input waveform, the input voltage of the charging circuit 16 starts at OV and begins to rise. The switching transistor 14 remains on until the input voltage reaches approximately 48 V and then switches off for a short time. The transistor then switches on and off with the "on" time of the transistor becoming shorter until the AC waveform reaches its maximum voltage. As the AC voltage begins decreasing, the "on" time of the transistor 14 becomes increasingly long until the AC voltage again reaches 48 volts. The switching transistor 14 will then remain on until the AC voltage again rises above 48 volts. The pulse-width modulation circuit 16 operates at approximately 10 kHz, and this provides a minimum "on" or "off" time of approximately 10 microseconds. The actual combination of "on" or "off" cycles will depend on the output current of the charging circuit and the temperature of the battery. Fluctuations in the peak voltage of the AC input line will also be compensated by the pulse-width modulation circuit 16.
FIG. 3 shows an electrical schematic of the high-power factor switching-type charging circuit supply. In addition to the components previously described in FIG. 1, the low voltage power supply, the pulse-width modulation circuit 16 and the DC voltage reference circuit 19 are shown in greater detail.
The low voltage power supply comprises a diode 34 which is connected to diodes 33 and 36. The second terminal of diode 34 is connected to a terminal A and to a capacitor 38. The second terminal of capacitor 38 is connected to chassis ground. Terminal A provides a positive voltage of approximately 10 volts and is used to provide the positive voltage to the various amplifiers and circuits used in the dual feedback loop system. Some of these circuits also require a negative voltage which is provided by a diode 37 and capacitor 39. The negative voltage is developed at terminal B which is then connected to the amplifiers which require a negative voltage.
The pulse-width modulation circuit 16 comprises a ramp generator formed by unijunction transistors 41 and 42, a comparator 43 and a drive circuit formed by transistors 46, 47, 50 and 51.
In operation, the capacitor 40 begins to charge at a constant rate with a current supplied by the current source formed by the unijunction transistor 41 and resistor 60. The capacitor voltage rises linearly until the capacitor voltage reaches the turn-on threshold of unijunction transistor 42. When transistor 42 switches to a conducting state, current flows through the base of transistor 42 until capacitor 40 is completely discharged. The cycle then repeats continuously, thereby creating a ramp or saw-tooth waveform. The output of the ramp generator circuit is then connected to comparator 43. The comparator is a standard operational amplifier circuit which operates without feedback. The capacitor 44 provides compensation for the operational amplifier circuit.
The amplifier 24 is connected to a second input terminal of comparator 43. The comparator 43 will have an output which is either high or lower depending on the relative output voltage of the ramp generator and the output voltage of amplifier 24. The output signal created by comparator will then be a square wave of variable duty cycle responsive to the sinusoidal voltage reference and the output current requirement of the charging circuit.
The output of comparator 43 is then coupled to transistors 46 and 47 through a resistor 45. The emitters of transistors 46 and 47 are coupled to the bases of transistors 50 and 51 through resistor 48. The emitters of transistors 50 and 51 are coupled to the switching transistor 14 through resistor 52. The transistors 46, 47, 50 and 51 are of the general switching class of transistors and are designed to increase the output current of comparator 43 to a level required by switching transistor 14. The terminals A and B provide power to the comparator and the associated output transistors.
The comparator 43 can be of the type LM318 available from several manufacturers and the output transistors can be of the general class of switching transistors.
The amplifier 23 generates a signal which is related to the output current of the regulator, as well as the temperature and voltage of the battery under charge. The amplifier 23 is connected to the output of amplifier 21 which is a signal related to the output current of the charging circuit. The amplifier 23 also has an input connected to a variable resistor 22 which in turn is connected to a DC voltage reference circuit 19.
The DC voltage reference circuit 19 generates a reference voltage which is related to the battery voltage and temperature. The battery under charge is coupled to a temperature sensitive resistor 55 which is in physical contact with the battery. The battery is also connected to a resistor 64. The temperature sensitive resistor 55 is coupled to a resistor 56 which in turn is coupled to a resistor 57. The second terminal of resistor 57 is coupled to the negative terminal of the battery 20. The resistors 55, 56 and 57 comprise a resistive divider network and provide a reduced voltage which is compatible with the input of amplifier 62. The junction of resistors 56 and 57 provide an input to amplifier 62. This junction is also connected to a resistor 63. The resistor 63 is also connected to the output of amplifier 62 which provides a feedback path to control the gain of amplifier 62. The second input terminal of amplifier 62 is connected to a resistor 58 and a zener diode 60. The resistor 58 also has a terminal connected to the low voltage power supply A. Resistor 58 and diode 60 provide a fixed voltage reference for amplifier 62.
The amplifier 62 is connected to a zener diode 65 and a resistor 64. The zener diode also has a connection to the negative terminal of the battery 20. These components provide a power source for amplifier 62 which is independent of the actual battery voltage.
The output of amplifier 62 is coupled to a resistor 66. The resistor 66 is then coupled to an opto-isolator 69. The opto-isolator 69 is identical to opto-isolator 26. The output of amplifier 62 controls the intensity of light-emitting diode 67 which in turn controls the resistance of the photo-sensitive resistor 68. The photo-sensitive resistor is coupled to the positive low voltage power source A. The opto-isolator is required to isolate the operating potential of the DC voltage reference circuit from the lower operating potential of amplifier 23.
Thus the charging voltage of battery 20 is converted to a level compatible with the voltage regulator loop. Through this loop, the temperature and voltage of battery 20 control the amplitude of the sinusoidal voltage reference, which in turn, scales the output current of the charging circuit.
The foregoing embodiment has been intended as an illustration of the principles of the present invention. Accordingly, other modifications, uses and embodiments will be apparent to one skilled in the art without departing from the spirit and scope of the principles of the present invention. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is a reinforced molding, for example a connector, such as a quick connector, suitable for use in a fuel-line system, particularly for use in an automobile. The reinforced molding of the present invention may be an injection-molded connector between plastic pipes (in particular those of fuel lines) as well as a molding used in other assemblies (e.g. injection rail, metal pipes, fuel filter, other plastic pipes or the like). Specifications for quick connectors are provided by SAE J2044.
2. Discussion of the Background
Generally, the flow of a substance over a plastic surface can cause a build-up of a static electrical charge on the plastic surface. Such plastic surfaces may include, for example, fuel lines in automobiles, and other types of plastic piping used to convey liquids and solids, and/or plastic components of piping used to convey liquids or solids. If the static electrical charge build-up is sufficiently great, sudden electrical discharges can result, which can cause various problems, such as degradation of the plastic surface, and/or ignition of the solids or liquids conveyed therein. For example, in internal combustion engine powered motor vehicles, high levels of static electrical charge arise in fuel-line systems as a result of the flow of fuel. This can lead to sudden electrical discharges resulting in the formation of perforations in the fuel-line wall, through which the fuel can escape. The fuel can then ignite if it contacts hot components within the engine compartment or the exhaust system, thereby causing a fire in the motor vehicle.
In order to avoid this problem, all of the components of the system, and therefore also the connectors, should be conductive. This requirement means that a conducting connection must first be provided between the individual components of the system, and second, a conducting connection must be provided between the system and an electrical “ground.” In the case of an automotive fuel line, for example, an electrical connection should be maintained between the motor vehicle chassis and the components of the fuel-line system. In this way, the motor vehicle chassis and the components of the pipeline system are maintained at the same electrical potential, which prevents the build-up of electrical charge in the fuel-line system.
JP-A 207154/95 proposes producing connectors for fuel-line systems from a molding composition based on nylon-11 or nylon-12, in each case comprising from 5 to 20% by weight of carbon fibers and from 5 to 25% by weight of glass fibers. However, these molding compositions have poor flowability because of their high fiber content, which makes it considerably more difficult to produce small volume injection-molded items. These molding difficulties are further exacerbated if the mold has two or more cavities (i.e., molds used in producing fuel-line quick connectors). The longer flow paths in such molds make it even more important for the molding composition to have good flowability.
However, replacing the carbon fibers in the molding compositions of JP-A 207154/95 with a conductive black filler to improve the electrical conductivity of the molding eliminates some of the reinforcement in the composition, thereby weakening the molding. Furthermore, the amount of carbon black required generally increases the melt viscosity of the composition, which in turn adversely affects the filling of the cavity during injection molding. In addition, such compositions also exhibit lower impact strength.
A multi-layer structure is described in U.S. Pat. No. 5,798,048 for a plastic fuel filter housing. However, that publication does not relate to reinforced molding compositions, or with the problem of precisely reproducing finely structured surfaces from a mold.
The object of the present invention is therefore to provide plastic moldings such as connectors which are conductive and easily injection molded, and in which surface details, e.g. protrusions, recesses, grooves for O-rings, etc. can be reproduced with precision from the mold. At the same time, the molding should have sufficient fiber reinforcement to achieve the desired stiffness.
SUMMARY OF THE INVENTION
This object of the present invention may be achieved by a connector having a continuous conductive path from the inner to the outer surface and comprising:
A) a skin layer on the inner and outer surface of said molding, comprising an electrically conductive molding composition A; and
B) a core disposed between the skin layer on the inner and outer layer of said molding comprising a plastic molding composition B which differs from A.
BRIEF DESCRIPTION OF DRAWING
FIG. 1 shows a side view and cross section views of an example of a reinforced molding according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a side view of an example of an embodiment of a novel reinforced molding ( 1 ) of the present invention. The section ( 2 ) of the wall cross section has been enlarged above ( 3 ). As shown in the enlarged cross-section view ( 3 ), the core ( 5 ) comprising reinforced molding composition B is substantially enclosed by the skin layer ( 4 ) comprising molding composition A.
It is preferable for the molding composition A comprising the skin layer to be essentially free from reinforcing materials such as glass fibers. Specifically, it should not comprise more than about 15% by weight, preferably not more than 10% by weight and particularly preferably not more than 5% by weight of reinforcing material. It is particularly preferred that molding composition A contain no reinforcing material at all.
Molding compositions A and B may be composed of the same or different base polymers. By base polymers, we mean the polymer or polymers which comprise the polymeric matrix which provides the structure of the molding. For example, the base polymer of molding composition A forms the skin layers of the molding. Likewise, the base polymer of molding composition B forms the core layer of the molding. In addition to the base polymer, the molding composition A may also contain an electrically conductive additive, and molding composition B may also contain a reinforcing material. It is preferable that the polymer combinations of the present invention be mutually compatible molding compositions or molding compositions modified with compatibilizers. The base polymers used in molding compositions A and B may be selected based on the general objectives pursued:
a) Reducing the cost of the polymer base. In this case, component B may be composed of a molding composition which is less expensive than that of component A;
b) Increasing the barrier properties of the ultimate molding with respect to the chemicals (i.e., fuel or individual components of fuel) with which the molding is expected to come in contact. By barrier properties, we mean the properties of a material whereby the rate of permeation of a penetrant chemical (i.e., fuel) through the material is slowed, for example by virtue of the low solubility and/or diffusivity of the penetrant chemical in the barrier material. For example, the material combinations used in molding compositions A and B may be the same as that used for multilayer pipes having two or more layers, as is described in the following patents and patent applications, incorporated herein by reference:
DE-A or DE-C 40 01 125, 40 06 870, 41 12 662, 41 12 668, 41 37 430, 41 37 431, 41 37 434, 42 07 125, 42 14 383, 42 15 608, 42 15 609, 42 40 658, 43 02 628, 43 10 884, 43 26 130, 43 36 289, 43 36 290, 43 36 291, 44 10 148 and 195 07 025, and also WO-A-93/21466, WO-A-94/18 485, EP-A-0 198 728 and EP-A-0 558 373;
c) Stiffening the molding by using a highly fiber-filled molding composition as material for component B.
Component A may be a molding composition comprising any thermoplastic resin, for example polyamides, polyesters, polyolefins, polysulfones, polyethersulfones, polyarylene oxides, polyimides, polyacrylates, polymethacrylates, polyurethanes, polycarbonates, etc. Polyamides, polyesters, and polyolefins are preferred thermoplastic resins, and polyamides are an especially preferred thermoplastic resin.
Component B may be, for example molding compositions based on polyamides, polyolefins, thermoplastic polyesters, fluoropolymers, polyoxymethylene, polysulfones, polyethersulfones, polyarylene oxides, polyimides, polyacrylates, polymethacrylates, polyurethanes, polycarbonates, or EVOH. Polyamides, polyolefins, thermoplastic polyesters, fluoropolymers, polyoxymethylenes and EVOH resins are preferred thermoplastic resins, and polyamides are an especially preferred thermoplastic resin. An example of a polyamide p-xylylenediamine (e.g. nylon-MXD6).
Other polyamides which may be used are mainly aliphatic homo- or copolyamides, for example nylon-4,6, -6,6, -6,12, -8,10, or -10,10, or the like, preferably nylon-6, -10,12, -11, -12, and also -12,12. (The terms for the polyamides follow the International standard in which the first number is the number of carbon atoms in the starting diamine and the last number is the number of carbon atoms in the dicarboxylic acid. If only one figure is mentioned, this means that the starting material for the polyamide is an α,ω-aminocarboxylic acid or its derivative lactam, as described in H. Domininghaus, Die Kunststoffe und ihre Eigenschaften (Plastics and Their Properties), p. 272, VDI-Verlag, (1976).)
The polyamides of the present invention may also be copolyamides, containing, for example, adipic acid, sebacic acid, suberic acid, isophthalic acid or terephthalic acid as coacids and, respectively, bis(4-aminocyclohexyl)methane, trimethylhexamethylenediamine, hexamethylenediamine or the like as codiamines.
The preparation of such polyamides is known (e.g.: D. B. Jacobs, J. Zimmermann, Polymerization Processes, pp. 424-467: Interscience Publishers, New York (1977); DE-B21 52 194).
The polyamides may be used alone or in mixtures.
Other suitable polyamides are mixed aliphatic/aromatic polycondensates, e.g. as described in U.S. Pat. Nos. 2,071,250, 2,071,251, 2,130,523, 2,130,948, 2,241,322, 2,312,966, 2,512,606, 3,393,210 or in Kirk-Othmer, Encyclopedia of Chemical Technology, 3rd ed., Vol. 18, Wiley & Sons (1982), pp. 328 and 435. Other polycondensates which may be used are poly(etheresteramides) and poly(etheramides). Products of this type, for example, are described in DE-A 27 12 987, 25 23 991 and 30 06 961.
The number-average molecular weight of the polyamides may be above 4000, preferably above 10,000, and preferably have a relative viscosity (η rel ) in the range of from 1.65 to 2.4.
The polyamide molding compositions may also comprise up to 40% by weight of other thermoplastics as long as these other thermoplastics do not impair the properties of the moldings of the present invention. In particular, such thermoplastics may include polycarbonate polymers (H. Schnell, Chemistry and Physics of Polycarbonates, Interscience Publishers, New York (1981)), acrylonitrile-styrene-butadiene polymers (Houben-Weyl, Methoden der organischen Chemie (Methods of organic chemistry), Vol. 14/1, Georg Thieme Verlag Stuttgart, pp. 393-406; Ullmanns Encyclopadie der technischen Chemie (Ullmann's Encyclopedia of Industrial Chemistry), 4th edition, Vol. 19, Verlag Chemie Weinheim (1981), pp. 279-284), acrylonitrile-styrene-acrylate polymers (Ullmanns Encyclopadie der technischen Chemie, 4th edition, Vol. 19, Verlag Chemie Weinheim (1981), pp. 277-295), acrylonitrile-styrene copolymers (Ullmanns Encyclopadie der technischen Chemie, 4th edition, Vol. 19, Verlag Chemie Weinheim (1981), pp. 273 et seq.) or polyphenylene ethers polymers (DE-A 32 24 691 and 32 24 692, U.S. Pat. Nos. 3,306,874, 3,306,875 and 4,028,341).
The polyamides may be impact-modified if desired. Examples of suitable impact modifiers are ethylene-propylene copolymers and ethylene-propylene-diene copolymers (EP-A-0 295 076), polypentenylene, polyoctenylene and random- or block-structured copolymers made from alkenylaromatic compounds with aliphatic olefins or with aliphatic dienes (EP-A-0 261 748). Other impact-modifying rubbers which may be used are core-shell rubbers with an elastomeric core made from (meth)acrylate rubber, from butadiene rubber or from styrene-butadiene rubber with, in each case, a glass transition temperature T g <−10° C. The core may be crosslinked. The shell may be composed of styrene and/or methyl methacrylate and/or other unsaturated monomers (i.e., those described in DE-A 21 44 528, 37 28 685). The amount of the impact-modifying component used in the molding composition should be selected so that the desired properties are not impaired.
Polyolefins which may be used in the molding compositions of the present invention are homopolymers or copolymers of α-olefins having from 2 to 12 carbon atoms, for example ethylene, propene, 1-butene, 1-hexene or 1-octene.
Other suitable materials are copolymers or terpolymers which, in addition to the above monomers, may also contain other monomers, in particular dienes, such as ethylidenenorbornene, cyclopentadiene or butadiene.
Preferred polyolefins are polyethylene and polypropylene. Any commercially available grade of these polyolefins may be used in principle. For example, high-, medium- or low-density linear polyethylene, LDPE, copolymers of ethylene with relatively small amounts (up to a maximum of about 40% by weight) of comonomers, such as n-butyl acrylate, methyl methacrylate, maleic anhydride, styrene, vinyl alcohol, acrylic acid, glycidyl methacrylate or the like, isotactic or atactic homopolypropylene, random copolymers of propene with ethene and/or butene, ethylene-propylene block copolymers and the like may be used. Polyolefins of this type may also contain an impact-modifying component, e.g. EPM rubber or EPDM rubber or SEBS. They may also contain functional monomers, such as maleic anhydride, acrylic acid or vinyltrimethoxysilane grafts.
The thermoplastic polyesters have the following basic structure
where R is a bivalent branched or unbranched aliphatic and/or cycloaliphatic radical having from 2 to 12, preferably from 2 to 8, carbon atoms in the carbon chain, and R′ is a bivalent aromatic radical having from 6 to 20, preferably from 8 to 12, carbon atoms in the carbon skeleton.
Examples of the diols which may be used to prepare thermoplastic polyesters may include, for example, ethylene glycol, trimethylene glycol, tetramethylene glycol, hexamethylene glycol, neopentyl glycol, cyclohexanedimethanol and the like.
Up to 25 mol % of these diols may be replaced by a diol of the following general formula
where R″ is a bivalent radical having from 2 to 4 carbon atoms and x can be from 2 to 50. Preferred diols include ethylene glycol and tetramethylene glycol.
Examples of aromatic dicarboxylic acids which may be used to prepare the thermoplastic polyesters include, for example, terephthalic acid, isophthalic acid, 1,4-, 1,5-, 2,6- or 2,7-naphthalenedicarboxylic acid, diphenic acid, diphenyl ether 4,4′-dicarboxylic acid or polyester-forming derivatives thereof, e.g. dimethyl esters. Up to 20 mol % of these dicarboxylic acids may be replaced by aliphatic dicarboxylic acids, e.g. succinic acid, maleic acid, fumaric acid, sebacic acid, dodecanedioic acid, etc.
Methods for preparing thermoplastic polyesters are well known. See, for example, DE-A 24 07 155, 24 07 156; Ullmanns Encyclopadie der technischen Chemie, 4th edition, Vol. 19, pp. 65 et seq., Verlag Chemie GmbH, Weinheim 1980.
The polyesters of the present invention have a viscosity number (J value) in the range from 80 to 240 cm 3 /g.
Preferred thermoplastic polyesters may include, for example, polyethylene terephthalate, polybutylene terephthalate, polyethylene 2,6-naphthalate and polybutylene 2,6-naphthalate. The polyesters may also be impact-modified.
Examples of suitable fluoropolymers which may be used in the molding compositions of the present invention include ethylene-tetrafluoroethylene copolymers (ETFE, e.g. Tefzel 200 from DuPont or Hostaflon ET 6235 from Hoechst), tetrafluoroethylene-hexafluoropropene-vinylidene fluoride terpolymers (THV; e.g. THV 500 from Dyneon), ethylenechlorotrifluoroethylene copolymers (ECTFE; e.g. Halar from Ausimont) and polyvinylidene fluoride (PVDF).
ETFE, THV and ECTFE are described, for example, in H. Domininghaus, Die Kunststoffe und ihre Eigenschaften, 4th edition, Section 2.1.7 (Fluorinated Plastics). The preparation and structure of polyvinylidene fluoride is likewise known (Hans R. Kricheldorf, Handbook of Polymer Synthesis, Part A, Verlag Marcel Dekker Inc., New York—Basle—Hong Kong, p. 191-192: Kunststoff-Handbuch (Plastics Handbook), 1st edition, Vol. XI, Carl Hanser Verlag Munich (1971), p. 403 et seq.).
It is also possible to use polymers based on polyvinylidene fluoride and having up to 40% by weight of other monomers. Such additional monomers may be, for example, trifluoroethylene, ethylene, propene and hexafluoropropene.
The polyvinylidene fluoride of the present invention generally has a melt flow index of less than 17 g/10 min., preferably from 2 to 13 g/10 min (DIN 53 735), measured at 230° C. with a load of 5 kg.
Examples of material combinations which may be used in the present invention are:
A=molding composition based on polyamide, in particular nylon-6, nylon-6,6, nylon-6,12, nylon-11 or nylon-12
B=PVDF, other fluoropolymer, polybutylene terephthalate or polybutylene naphthalate, EVOH or a polyamide compatible with A, for example a grade based on m- or p-xylylenediamine and adipic acid.
These polymers may be used either alone or in mixtures. Besides the impact modifiers described above, the molding compositions of the present invention may also contain conventional additives, such as processing aids, mold-release agents, stabilizers, flame retardants or mineral fillers, e.g. mica or kaolin.
The molding composition A is rendered conductive by compounding the base polymer with an electrically conductive additive. This may be done by any conventional method. For example, the base polymer may be compounded with the electrically conductive additive using a conventional single screw extruder, twin screw extruder, or other conventional polymer compounding equipment Examples of electrically conductive additives which may be used are conductive carbon black, metal flakes, metal powders, metallized glass beads, metal fibers, (e.g., stainless steel fibers), metallized whiskers, carbon fibers (which may be metallized), intrinsically conductive polymers and, in particular, graphite fibrils. Mixtures of different conductive additives may also be used. The surface resistance of the molding comprising the molding compositions of the present invention should be low enough that electrical charges can be reliably dissipated.
Graphite fibrils are described, for example, in Plastics World, November 1993, pp. 1011. Graphite fibrils are tiny fibers made from crystalline graphite with average diameters of not more than about 700 nm. The average diameter of graphite fibrils currently available commercially is on the order of 0.01 micron, with an L/D ratio of the order of 500:1-1000:1. Graphite fibrils as described in the WO applications Nos. 8603455, 8707559, 8907163, 9007023 and 9014221, and also in JP-A-03287821, are also suitable in principle for the purposes of the present invention.
The content of graphite fibrils in the molding composition may generally be from 1 to 30% by weight, preferably from 1.5 to 10% by weight and particularly preferably from 2 to 7% by weight.
In another preferred embodiment, the molding composition A comprises from 3 to 30% by weight, preferably from 10 to 25% by weight and particularly preferably from 16 to 20% by weight, of a conductive carbon black which has the following properties:
a) dibutyl phthalate (DBP) absorption of from 100 to 300 ml/100 g, preferably from 140 to 270 ml/100 g (ASTM D2414);
b) specific surface area of from 30 to 180 m 2 /g, preferably from 40 to 140 m 2 /g (measured by nitrogen absorption according to ASTM D3037);
c) ash content below 0.1% by weight, preferably below 0.06% by weight, particularly preferably below 0.04% by weight (ASTM D1506);
d) grit content of not more than 25 ppm, preferably not more than 15 ppm and particularly preferably not more than 10 ppm.
For the purposes of the present invention, grit is hard, coke-like particles which are produced by cracking reactions during the preparation of the conductive carbon black.
This conductive carbon black is a specific grade whose properties differ from those of conventional conductive carbon blacks. For example, a typical commercially available EC carbon black (extra conductive carbon black) has a DBP absorption of 350 ml/100 g, a specific N 2 surface area of 1000 m 2 /g and an ash content of 0.7% by weight. The molding compositions which contain this specific grade of conductive carbon black have improved heat-aging resistance, and also higher resistance to peroxide-containing fuels, compared to compositions containing other grades of conductive carbon black. Although the precise reason for this difference is not well known, it is likely that the difference in performance is connected with the differences in the surface structure of the carbon particles, resulting in different catalytic activity, and also that the ash content of the carbon black likewise has catalytic activity.
The carbon blacks used in the molding compositions of the present invention may be obtained, for example, by the MMM process. The MMM process is based on the partial combustion of oil (N. Probst, H. Smet, Kautschuk Gummi Kunststoffe (Rubber and Plastics), 7-8/95, pp. 509-511; N. Probst, H. Smet, GAK 11/96 (Volume 49), pp. 900-905). Such carbon black products are available commercially.
In another preferred embodiment, the molding composition A comprises, in addition to the conductive carbon black, from 0.1 to 20% by weight of carbon fibers, based on the total weight, a content of not more than 16% by weight, in particular not more than 12% by weight, being generally sufficient. Since the carbon fibers themselves contribute to the electrical conductivity, if carbon fibers are used, an amount of preferably from 5 to 18% by weight of carbon black may be used.
Carbon fibers are available commercially and are described in Römpp Chemie Lexikon (Römpp's Chemical Encyclopedia), 9th edition, pp. 228990, Thieme, Stuttgart, 1993, for example, and also in the references cited there.
The reinforcing materials of molding composition B may include conventional fillers such as glass microspheres, kaolin, wollastonite, talc, mica or calcium carbonate, or reinforcing materials in the form of fibers such as glass, carbon, mineral, metal, or polymer fibers. Reinforcing fibers are the preferred reinforcing material. Suitable reinforcing fibers are known, for example glass fibers, carbon fibers, aramid fibers, mineral fibers or whiskers, as are molding compositions containing such fibers. The upper limit of fiber content is set only by the need for the fiber-reinforced molding composition to retain sufficient flowability during the molding process.
If necessary, components A and B may be bonded with the aid of an intervening adhesion promoter. Such adhesion promoters are known.
The thickness of the skin layer and of the core layer is highly dependent on the rheology of the molding compositions, on the shape of the molding, and, of course, on the molding process parameters. The thickness of the skin layer should be at least sufficient for it to encapsulate at least the majority of the core, preferably a very large part of the core, and most preferably all of the core.
The novel reinforced moldings of the present invention may be produced by multi-component injection molding or by the mono-sandwich process.
The production of plastic items by multi-component injection molding is known (see, for example, Th. Zipp, Flieβverhalten beim 2-Komponenten-Spritzgieβen (Flow Behavior in 2-Component Injection Molding), Dissertation, RWTH Aachen, 1992). When using two components A and B, the conductive component A is first put in place and the nonconductive component B is then injected. A procedure of this type produces the layer sequence A/B/A, viewing a section through the wall, but at the beginning and end of the flow path the conductive layer A has no interruption, since component B fills only the core region. This ensures continuous transfer of electrical charges from the inside of the moding to the outside of the molding.
The mono-sandwich process is also known (see, for example C. Jaroschke, Neue Wege beim Sandwich-Spritzgieβen (New Paths in Sandwich Injection Molding), Kunststoffe 83 (1993) 7, pp. 519-521).
The reinforced molding of the present invention may be very stiff, e.g., when the core is a highly filled molding composition, but nevertheless any surface details and profiling, such as protrusions, etc may be easily formed because the skin layers have good flowability during the molding process. In addition, because the core layer need not contain a conductivity additive, considerable material and cost savings may also achieved.
The priority document of the present application, German patent application 10025707.0 filed May 26, 2000, is incorporated herein by reference.
Obviously, numerous modifications and variations on 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 herein. | 4y
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BACKGROUND OF INVENTION
1. Field of Invention
This invention relates generally to maintenance and repair devices used to test, service, and replace switched electrical lighting, and other electrical devices, that are controlled by modular photoelectric control switches.
2. Description of Prior Art
Modular photoelectric control switches, commonly called photoelectric cells, are used to control a wide variety of electrical devices. The most commom devices are lights, which are sometimes referred to as dusk-til-dawn lights, such as street lights and advertising sign lights. Most any other electrical device which is desired to be switched on, or off, at the advent of night or day may utilize modular photoelectric control switches. For examples, security sensors and heating and airconditioning units may also be switched. Modular photoelectric control switches will automatically switch in correlation to a design threshold of the switch and the amount of light striking its photoelectric sensor.
Most modular photoelectric control switches are located overhead, above human reach. This reduces interference with the amount of light striking the sensor. When it is known or suspected that modular photoelectric control switch has malfunctioned, a repairman must elevate to the switch location to identify the problem and take corrective action. Currently the module is serviced by elevating the repairman by means of manual climbing, the use of hydraulic lifts, and climbing with the assistance of ladders, or other climbing equipment. The use of such elevating means, to access the module by hand, is either costly or timely inefficient, or both, and is often unsafe. A means for repairmen to safely and efficiently test and repair overhead modular photoelectric control switches, from ground level, is needed.
That need is met by this invention, herein called, the modular photoelectric control installation device. By attaching this device to a standard telescopic pole, alternatively referred to as a long pole, a repairman can perform all normally required test and maintenance of modular photoelectric control switches, from ground level. Telescopic poles are associated with a variety of overhead electrical maintenance tasks, by use of various attached devices. Such specialized attachments may provide a means to replace fuses, cut cables, replace cotter keys, install electrical insulators, disconnect hot lines, and dispense from aerosol cans. Another attachment removes the bases of broken bulbs. Some of the most common long pole attachments are especially made to replace defective overhead lightbulbs. There are several types of bulb changers available commercially. One is commonly called the McGill lamp changer. It should be noted here, that one embodiment of the current invention can also change bulbs.
But, there has not been available a reliable, efficient, and safe means of testing and replacing the modular photoelectric switches. Yet, most switches are connected to, and usually located close to, a lightbulb. Usually, the bulb is a high intensity sodium, or mercury vapor bulb, when used in conjunction with a modular photoelectric control switch. Most commonly the switch and bulb are co-located in the same fixture, such as in a street light. Unless there is physical damage to either the bulb or the module, it is not normally possible to visually determine which component has malfunctioned. Basically, the same is true when the module is used with nonlight emitting components, because most repairs are made during the daylight hours. Therefore, electric current in the module would normally be switched off. Simply put, the appearence of both components will often be the same, even if both the bulb and the module were otherwise known to be defective.
In unknown situations, most repairmen simply proceed with a trial-and-error solution by replacing the bulb by means of a long pole attachment. If the problem subsequently proves, by deduction, to be located in the module the repairman will return and somehow gain hand access to the module. There exist a long pole attachment which will test the module. It is basically an opaque bonnet, which is lowered over the sensor of the module. Thereby, the light level is lowered and causes the module to switch. However, this attachment is not widely used. Unless both components function when the bonnet is used, it has no further utility in identifying and correcting the malfunction.
The modular photoelectric control installation device, however, performs the same test functions as the bonnet device. Furthermore, as necessary, it can subsequently remove and replace the module. Most new modular photoelectric control devices are designed to briefly self-test, regardless of light levels, by switching when initially installed. At this point in the test and repair process, by using the current invention, the repairman can deductively conclude which, if any, components are still defective. Yet, the repairmam has not been forced to use an extended trial-and-error repair method. Nor has it been necessary to expend the time, expense, and risk of working above ground level.
An assortment of hand tools have been adapted for use with the telescopic poles and are interchanged via a universal head. Such tools include hammers, screwdrivers, socket wrenches, and saws. These tools are used, within practical limitations, to make overhead electrical repairs. They are manipulated with the telescopic poles, basically as an extension of the hand and arm. Specialized interchaneable devices have also been adapted for overhead work with the telescopic pole. Some examples include insulator clamps and fuse pullers. These function mechanically when the repairman twist the pole with wrist action. Both hand tools and specialized devices have also been devised, that are activated by cables running the length of the telescopic pole.
Pulling the cable might depress a lever to activate an aerosol can button, or activate the release lever on vice grip pliers. Cable activatation, however, increases demands on manual dexterity and complicate the device. Even given the vast variety of tools and specialized devices adapted to pole use, none can safely, reliably, and efficiently complete the tasks testing and replacing modular photoelectric control switches. None prior to the current invention. The major reasons for the prior situation are largely related to both the design and construction of the photoelectric control switches.
Modular photoelectric control switches can vary somewhat in size and shape. However, most are approximately the size of a small apple. Most have either a basically cylindrical or truncated conical shape. The current invention adjusts to all known shapes and sizes. Nearly all control switches are encased with hard plastic, and similar materials, with smooth surfaces. The surfaces tend to create slippage of gripping members. If additional pressure is applied to the relatively small surface area, to overcome slippage, the case might become damaged. The sensor portion of the case is the most susceptible to damage by either excessive pressure or slippage. Slight damage to the case may merely reduce the effectiveness of control switch. More severe damage can produce an electrical shock hazard to a repairman.
Near all modular photoelectric control switches are slightly flared around the circumference of the base. The flare serves as a weather collar, when seated into the standardized power recepticle. As a module, photoelectrical switches must be plugged into the standardized power recepticle and twisted to lock them in position. This is accomplished by inserting the standardized three-pronged electrical contacts, located in the base of the control switch, into recepticle and twisting it approximately thirty degrees. Often the contacts become corroded, fused, or bent. These situations increase the amount of force needed to remove and install the module. Since the required force is exerted on the case of the photoelectric switch, it is critical that applied force not damage the case. The current invention dissipates pressure over a large portion of the case surface and, therefore, negates slippage between itself and the case.
Another difficulty overcome by the current invention is that of keeping the control switch case gripped, when it is lowered to groung level, or raised up. At times the distance exceeds thirty feet. But, inherent in the mechanical functioning of the current invention is its ability to maintain a constant pressure with a gripping member. Maintaining positive control during removal, will greatly assist positioning a control switch during installation. Additionally, embodiment of many pole adapted devices restrict the locations from which a repairman may perform an associated task. Some rejected embodiments, as related to the current invention, had similar disadvantages. However, the final embodiment of the current invention has no such restriction. The current invention is omnidirectional, imposing no location restrictions on the repairman. In arriving at a final, and functional, embodiment of the current invention, many existing gripping-type devices and principles were discarded as unusable. Included were devices incorporating box end ratchets, stud extractors, basin wrenches, slip and locknut wrenches, screw-type flare tools, pipe and other types of adjustable wrenches. As well as, screw-type clamps, including pipe cutters and gear pullers. Piston ring compression sleeves were also rejected as unsuitable. A suitable device has a near equal capability to act upon the control switch in opposing directions, without slippage. That is, to push and pull, to lift and to lower, and to twist right and left. Hence, the embodiment of the current invention.
Finally, the current invention can be remotely disconnected from the the telescopic long pole whenever desired, or when required by emergency situations. This capability is not found in other specialized devices associated with telescopic long poles. Rather, it is a unique safety feature of the current invention.
SUMMARY OF THE INVENTION
It is an objective of this invention to provide a product which is capable of both removing and installing, from ground level, modular photoelectric control switches that are located overhead.
It is an objective of this invention to provide a product to test the functioning of overhead photoelectric control switches, and indirectly, their associated electrical devices, without the necessity of elevating a repairman.
It is an objective of this invention to provide a product which reduces time, effort, and risk of hands-on testing and replacing overhead modular photoelectric control switches by integrating a test and replacement capability into an entity.
It is an objective of this invention to provide a product, which when conjuncted with a telescopic long pole, provides a cableless remote capability to test and replace overhead photoelectric control switches and bulbs with one entity.
It is an objective of this invention to provide a product which allows a repairman omnidirectional remote access to overhead photoelectric control switches, unless access is otherwise obstructed.
It is an objective of this invention to provide a product which will adjust to variously existing shapes and sizes of modular photoelectric control switches, yet maintain its effectiveness as a tester and installer.
It is an objective of this invention to provide a product which can maintain near equal effectiveness while imparting directional force in one direction and in a reciprocal direction.
This is a necessary objective related to efficiency when installation is the reverse of removal.
It is an objective of this invention to provide a product which, in one anticipated embodiment, incorporates a limited integral capability to replace light bulbs, yet retains all capabilities to test and service modular photoelectric control switches.
It is an objective of this invention to eliminate, to practical extents, above ground level test and repair of photoelectic control switches. Put another way, this is a safety objective to reduce injury primarily from falls and from electric shock from contact with known, or unknown, electrically energized objects. Nevertheless, it is logical to anticipate that this invention will also be used by repairman working from elevated worksites, as work conditions and tasks may require.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side perspective view of a ratchet wrench, showing that the base of said wrench handle is attached to the tip of a telescopic long pole, via a universal attaching head, wherein the telescopic pole, the universal head, and the ratchet form the drive member of the current invention, and showing the point of attachment of the drive member to the gripping member. Said attachment thereby forming the extended integral device of the current invention.
FIG. 2 is a side view showing details of the drive socket.
FIG. 3 is a top plan view the gripping member of FIG. 1, wherein the overlapping plates are schematically illustrated in relation to the barcam, and shows relocated contractors.
FIG. 4 is a side raised view of a modular photoelectric control switch, showing its functional relationship to the gripping member of FIG. 1.
LIST OF REFERENCE NUMERALS
1 telescopic pole
2 universal attaching head
2A left half
2B right half
3 bolt
4 wingnut
5 handle
6 flex-pivot pin
7 reverse lever
8 quick-release button
9 ratchet wrench
10 locking ball
11 ratchet drive
12 socket cavity
13 socket drive
14 barcam
15 shaft
16 flatwasher
17 locknut
18 openings
19 overlapping plates
20 slot
21 rivet
22 hole
23 contractor
24 stud
25 grips
25A front grip
25B rear grip
26 lining
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 shows in detail one embodiment of the photoelectric control module installation device. Extending linearly from the tip end of a telescopic pole 1 is a universal attaching head 2. Universal attaching head 2 comprises two similar opposing halves which are joined rigidly by means of a recessed bolt 3. Bolt 3 is passed through the center of both the right half 2A and left half 2B. A wingnut 4 secures the joining of the right half 2A and left half 2B, by attaching to bolt 3 on the outer surface of right half 2B. The inner surfaces of halves 2A and 2B have a series of mated splines around their circumference. When wingnut 4 is tightened, the mated splines of halves 2A and 2B are meshed and will not slip.
Although forming a single entity, when joined, the left half 2A of the universal attaching head 2 is directly affixed to telescopic long pole 1. The right half 2B is permanently affixed to whatever device is being attached to the telescopic pole 1, via the universal attaching head 2. In respect to the current device, the attached device is a ratchet wrench 9, having a handle 5. The base end of handle 5 comprises the right half 2B of universal attaching head 2. The opposite end of handle 5 is attached to a ratchet wrench 9, via a flex-pivot pin 6. Flex-pivot pin 6 provides that ratchet wrench 9 can be moved, by hand, changing the angular relation to handle 5. The degree of said change is plus, or minus, ninety degrees from a horizontal plane formed by the handle 5 and wrench 9. Angular changes in flex-pivot pin 6, as conjuncted with that in universal attaching head 2, will be operationally detailed later.
Ratchet wrench 9 comprises a reverse lever 7, whereby the radial movement of a ratchet drive 11 is selectable from clockwise to counterclockwise rotation. Ratchet drive 11 therefore will drive any member attached thereon in a radial direction in response to a corresponding position of the reverse lever 7. Attachment to the ratchet drive 11 is effected by inserting and locking ratchet drive 11 into a reciprocally shaped socket cavity 12. Insertion and locking into a socket cavity is effected by means of a quick-release button 8, located on the top of ratchet wrench 9 and in front of reverse lever 7.
A quick-release button 8 is connnected internally through ratchet drive 11 to a locking ball 10. Said locking ball 10 is normally raised above the surface of ratchet drive 11. However, pressing quick-release button 8 will withdraw locking ball 10 below the surface of ratchet drive 11. Thereby ratchet drive 11 may be inserted, with resistance, into socket cavity 12. Following said insertion, quick-release button 8 is released and locking ball 10 again rises above the surface of ratchet drive 11. Indentations in the interior walls of socket cavity 12 receive locking ball 10. Thereby members are attached and locked to ratchet drive 11. And, so remain until quick-release button 8 is pressed again, thereby unlocking for purposes of detaching a member from ratchet drive 11.
Although the preceding discussion on attaching member might appear more operational than appropriate here, it later avoids repetition of a conventional item, like ratchet wrench 9. Hereto discussed has been the perferred embodiment of the drive member, and its attachment to the gripping member. That is, the union of ratchet drive 11 and socket cavity 12. As a matter of specification, it is not intended that other embodiments of the drive member are not anticipated to be conjuncted with the gripping member, discussed hereafter. Given that right half 2B could be a feature of a nonflexible ratchet wrench, or a pullhandle socket wrench, is envisioned within the scope of the current device.
Further envisioned is that any socket wrench having a drive, similar to ratchet drive 11 can cause the gripping member to operate. Likewise, it is not intended to limit embodiment by use of a telescopic long pole 1. Though not preferred, alternatively a noninsulated pole, of fixed length, is included within the scope of the current device. Similarily, the permanent, or temporary, attachment of the drive member by means other than a universal attaching head 2 is envisioned. What is stated, herein, as the perferred embodiment should not be taken as meaning either the exclusive, the minimum, or the optimal embodiment.
From this point, the perferred embodiment is referenced to both FIGS. 1-3. The union of ratchet drive 11 and a socket drive 13, at socket cavity 12, comprises a completed assembly of the photoelectric control module installation device. Socket drive 13 is one piece, having three distinctively shaped portions. A top portion, shaped as an upright cylinder, and having a square socket cavity 12 centered in its top surface. Extending from the center bottom surface of sprocket drive 13, a center portion is a rectangular shaped barcam 14. Said barcam 14 having a rounded end, at each end of its long axis. A bottom portion of sprocket drive 13, extending downward from the center of the bottom surface of barcam 14 is a round shaft 15. Shaft 15, having a threaded end, is passed through the center of a flatwasher 16. Having passed through the flatwasher 16, the threaded end of shaft 15 is secured with a locknut 17. Thus, retaining flatwasher 16 onto shaft 15.
Socket drive 13 is inserted into identical openings 18 within two identical overlapping plates 19. Openings 18 are rectangular, but have a contour at one end. Both the overlapping plates 19 and the openings 18, although identical are symmetrically opposed, in opposite directions, one atop the other. The bottom surfaces of the cylindrical portion of sprocket drive 13, having a plane perpendicular to the sides of barcam 14, rest on the top surface of overlapping plates 19. The diameter of the cylindrical portion is greater than width of openings 18. Nearly all of the mass of the cylindrical portion of sprocket drive 13 is, therefore, centered over openings 18. The barcam 14 portion of sprocket drive 13, having a side height equal to the combined thickness of overlapping plates 19, rest within the cavity formed by openings 18. The top surface of flatwasher 16 is opposite the bottom surface of the lower overlapping plate 19, and has a larger diameter than the width of openings 18. Thereby, when locknut 17 is attached to shaft 15, the barcam 14 portion of sprocket drive 13 is secured loosly within the combined openings 18, of overlapping plates 19.
Since overlapping plates 19 are intended to move, in and out, in opposite directions a means of directing must be provided. Therefore, overlapping plates 19 have identical elongated slots 20, parallel to their axis of intended movement. Said slots 20 are equal to the distance of intended movement of overlapping plates 19. For purposes of this illustration, slots 20 are located on the centerline of the long axis of overlapping plates 19, and perpendicular to the straight end of openings 18. However, slots 20 will function equally well when located on opposing sides of the long axis of openings 18. A rivet 21 is placed through slots 20. Rivet 21 is secured in a hole 22 in the opposing overlapping plates 19. Said hole 22 is aligned with slot 20 in the opposing overlapping plates 19. The rivet 21 head is wider than the width of slot 20, and is rivited so as to allow a slight clearence between the bottom surface of the head and overlapping plates 19. Clearence should only be sufficient to secure together overlapping plates 19, yet allow rivet 21 to freely travel the length of slot 20.
Affixed to one, or more, sides of overlapping plates 19 is an elongated elastic contractor 23. Contractor 23 is attacheted at both free ends by a stud 24. Stud 24 is extended outwardly from the side outermost edges, the opposing overlapping plates 19. Contractor 23, is stretched parallel to the long axis of the overlapping plates 19, and being attached thereon, provides constant inward tension. Preferably contractor 23 is a spring. Alternatively, a flexible strap of latex rubber, or a material having similar properties, will suffice. In a static mode the tension of contractor 23 retains overlapping plates 19, and anything affixed thereon, in a closed position. The operationl aspects of contractor 23 will be detailed later. For the purposes of the perferred embodiment, an opposing pair of grips 25 are attached to the outer ends of overlapping plates 19.
Grips 25 form a vertically divided hollow cylinder, having equal halves rigidly affixed to overlapping plates 19. Thus, grips 25 extend downwardly, at opposing right angles, from the outermost edges of overlapping plates 19. Though nearly symmetrical, front grip 25A is slightly shorter than rear grip 25B. Purely as a matter of alternative construction, grips 25 could be affixed to overlapping plates 19 using a variety of techniques. Such techniques include bolts, screws, adhesives, and welding. Herein, the term affixed is also intended to delineate a difference in function and position of grips 25 from overlapping plates 19. It is preferred that in construction, grips 25 and overlapping plates 19 be correspondingly cast, molded, or stamped as one entity. The walls of grips 25 are shaped as semicircles and are preferred to grip rounded objects, similar to FIG. 4, objects of other various shapes can also be suitable gripped. Bonded to the entire interior surface of the walls of grips 25 is a ductile lining 26. A material such as latex rubber is preferred for lining 26 material. Alternatively most any durable material, having a slip-resistant surface under pressure, would likely be usable for lining 26. On a temporary basis, and as a possible repair material, ordinary duct tape will suffice as material for lining 26. In respect to construction materials all portions of the current device are preferred to be either low or nonelectrically conductive materials, for safety purposes.
For operation of the photoelectric control module installer, the drive member of FIG. 1 is attached to the telescopic long pole 1. A visual estimate is made of the angle from the ground level working location to the overhead modular photoelelectric control switch. To approximate that angle, and attach the drive member to the telescopic long pole 1, bolt 3 and wingnut 4 located in left half 2A of the universal attaching head 2 is loosened. Right half 2B is placed onto bolt 3 and opposes left half 2A. The two halves of universal attaching head 2 are moved radially, until the angle between telescopic long pole 1 and handle 5 approximates the visually estimated angle. When a corresponding angle is achieved, allowing for any physical obstructions, the two halves of the universal attaching head 2 are bolted together. The tightening of bolt 3 and wingnut 4 mates the splined inner surfaces of left half 2A and right half 2B. Thus the drive member is rigidly attached to telescopic long pole 1, at an appropriate angle service of an overhead modular photoelectric control switch.
To compelete assembly for operations, the gripping member is attached to the drive member. Quick-release button 8 is pushed to retract locking ball 10 in ratchet drive 11. Simultaneously, ratchet drive 11 is pushed into the socket cavity 12 located in the top of socket drive 13. When ratchet drive 11 is seated, quick-release button 8 is released. Thus the drive member and gripping are locked together, when locking ball 10 is released into the socket cavity 12. Although the term locked is used, it should be noted that if it is required, this union can be broken without pressing quick-release button 8. Separating the drive and gripping members while pressing quick-release button 8, though preferred, can be accomplished by simply pulling the two members in opposite directions. When the pulling force is sufficient, locking ball 10 is overridden and release effected. With minimal effort, sufficient pulling force can be applied by using the telescopic long pole 1, should the gripping member become entangled. This is an important safety aspect when using any device in close proximity to electricity. Nontheless, when locked together the drive and gripping members are prepared for routine opeartions.
Prior to operations reversing lever 7, located on ratchet wrench 9, is positioned for applying drive force counterclockwise. That is, the direction required for removal of a modular photoelectric control switch of FIG. 4. Simultaneously, that position allows handle 5 to be moved in free clockwise rotation by manulipation of the telescopic long pole 1. As a final check, the grips 25 are pulled manually to the fully open position and allowed to return to the normally fully closed position. Thus, ensuring that the assembled device is operational. Controlled manually from the far end of the telescopic long pole 1, the tip end with the assembled device, of FIG. 1, is raised into position.
The rear grip 25B, being slightly longer than front grip 25A, is placed in contact with the upper side of the modular photoelectric control switch case. The bottom edge of front grip 25A will normally be in contact with the top edge of the case, on the opposing side. Using the longer portion of grip 25B, and the upper side of the case, as a point of resistance a slight forward and downward pushing motion is initiated with telescopic long pole 1. The forward inertia is transmitted by the drive member, to sprocket drive 13, and thence to flatwasher 16. Flatwasher 16 is pushed into contact with the head of rivet 21, protruding from slot 20 on the lower surface of overlapping plates 19. Being connected to the upper overlapping plate 19, through slot 20, front grip 25A is caused to extend forward. The forward pushing motion simultaneously overcomes the inward tension of contractor 23. Thereby front grip 25A is moved away from grip 25B to a distance, along the path of inertia, exceeding the diameter of the top of modular photoelectric control switch case. The downward motion of the telescopic long pole 1, thereby causes the current device to seat onto the control switch case. In many control switch cases, having a smaller top than bottom diameter, only a slight downward inertia is required to seat the current device.
When the pushing motion is discontinued, the elastic tension of the contractor 23 will pull overlapping plates 19 inward. Hence affixed grips 25are pulled snug against the outer walls of switch case. Once seated, grips 25 will lower the amount of light striking the photoelectric sensor to a level below the designed threshold. Even when the space between front grips 25A and 25B are incident to the sensor, the light level is sufficiently beneath the threshold to cause switching. If the modular photoelectric Control does not switch according to visual and audible indications, it has failed to test operationally and is removed. If the modular photoelectric control functions normally, the current device is removed with a simple upward motion of telescopic long pole 1.
If removal of the modular photoelectric contol switch is indicated by testing, it is unlocked from its receptacle by short alternating left and right motions of the telescopic long pole 1. Since the reverse lever 7 was placed in a position to drive counterclockwise, before beginning testing, the ratchet drive 11 rotates counterclockwise. Movement of the drive member counterclockwise causes sprocket drive 13, and therefore, barcam 14 to rotate in the same direction. When grips 25 and overlapping plates 19 and openings 12 moved outwardly, in seating, their symmetrical opposites moved in opposite directions. The effect of that movement on openings 18 was to bring the straight opposing ends closer together. Barcam 14 cannot rotate freely now, because the relative size of openings has decreased.
Now, when barcam 14 moves counterclockwise, responding to movement of the drive member on sprocket drive 13, its ends contact the contracted and opposite ends of openings 18. Contact with the ends of barcam 14, as it attempts to rotate, forces the edges of openings 18 inwardly. Correspondingly, both overlapping plates 19 and grips 25 are forced inwardly. The inward direction creates increased force, or gripping pressure, on any object larger than the normally closed diameter of grips 25. When securely gripped that object will tend to rotate in the counterclockwise with the gripping member. That is, unless slippage prevents an effective gripping action. The combined effects of contractor 23 and the traction of lining 26 combine to provide a means of preventing torque from being lost by slippage, until grip becomes an effective force. Without the initial resistance provided by contractor 23, and lining 26, the grips 25 will merely rotate freely and counterclockwise.
When securely gripped, the case of the modular photoelectric control is rotated approximately thirty degrees, by ratchet action. When the modular photoelectric control cannot be further rotated counterclockwise, it is unlocked and free to move from its receptacle. Removal is effected by an upward motion of telescopic long pole 1. While the modular photoelectric control is lowered to ground level, it remains securely gripped. Contractor 23 and lining 26 provide sufficient inward force to maintain grips 25 in a constant position. Additionally, the sprocket drive 13 tends to be mechanically resistant to movement unless initiated by the drive member.
Prior to pulling a faulty modular photoelectric control switch from grips 25, the relative position is noted. A replacement control is pushed into grips 25 in the same position, to assist in positioning electrical contacts into the receptacle. Unless the workstation has changed, it should not be necessary to readjust the angle of universal attaching head 2. Minor changes in angle can be made by manually moving rachet wrench 9, up or down, at the flex-pivot pin 6. Reverse lever 7, however, must be switched to the opposite position. Switching reverse lever 7 will effect clockwise rotation for installation, in the reverse manner of counterclockwise rotation for removal.
Should a change in workstation be required, the current device is omnidirectional. Given that the current device can be used with equal effectiviness in any location, from which the overhead control module is not blocked by obstruction in the line of sight. The current device has no features which limits its access. Given the combined flexibility of the universal attaching head 2, the flex-pivot pin 6, and the human arm, the current device can be adjusted to assimilate a complete circular flexibility along any radiant from universal attaching head 2. In theory, the current device can even compensate for the existance of telescopic long pole 1. In most all operations, no more than arms length movement is ever required.
While it might appear difficult to install a modular photoelectric control into its receptacle, the task is assisted by the receptacle. A standard receptacle has a slightly raised circle around its electrical contact slots. The raised circle is designed to fit beneath the weather collar around the base of a standard modular photoelectrical control switch. While the receptacle and the three-pronged plug under the control switch are often obstructed from view, the raised circle assist the installer in locating the receptacle by feel and available visual references. Remember that the replacement control was placed into grips 25 in the same position as the removed control switch. Once the raised circle of the receptacle is located only minor adjustments, by arm movement, should be required to mate the plug prongs and the receptacle slots. Actually, the plug prongs and the slots are mostly self-seating, requiring only a slight downward movement of the telescopic pole 1. Twist locking of the modular photoelectric control switch, is operationally and mechanically the exact reverse of removal. As to the degree of manual skills required to utilize the current device, remember that electrical repairmen are routinely expected to extract and install cotter keys by use of another device attached to a telescopic long pole 1.
To remove a light bulb with the current invention, the previously described method of adjusting universal attaching head 2 until a straight is formed between handle 5 and telescopic long pole 1. Ratchet wrench 9 is manually adjusted to be perpendicular to handle 5 via flex-pivot pin 6. Reverse lever 7 is a set counterclockwise drive for removal of a bulb. The current invention is raised directly below, and contacting the bulb. The end shapes of most high intensity lights associated with overhead lighting, will,spread grips 25 allowing them to seat onto the bulb. Any resistance of lining 26 and the bulb surface is normally overcome by a wiggling and pushing motion of telescopic long pole 1. Extraction is accomplished by a twisting motion of telescopic long pole 1. Manually the insertion of a bulb is the exact reverse of the removal. Mechanical operation of the current device is exactly the same as the aforementioned operation for modular photoelectric control switches. While the current device cannot remove broken bulb bases, it is envisioned that a device similar to the one currently used as an attachment could be adapted to use with the current device. All that would be required is fitting the device with base suitable for inserting into grips 25.
In summary, the innovation of the photoelectric control module install device provides a safe, reliable, and economical method of performing test, removal, and installation of overhead photoelectric control switches into a single integral device. While the above description contains specifics, these should not be construed as limiting the scope of the device. Rather, the above description is but one preferred embodiment of having other utilities. For example, possible modification to adapt a variety of associated devices having basically round bases and being attached via the grips of the current device. Accordingly, the scope of the preferred device cannot be determined by a single embodiment, but rather in conjunction with the appended claims and their equivalents. | 4y
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BACKGROUND OF THE INVENTION
The present invention generally relates to fabrication of semiconductor devices and more particularly to an epitaxial growth of a compound semiconductor layer such as gallium arsenide on a silicon wafer.
Gallium arsenide (GaAs) is a typical compound semiconductor material used for laser diodes and various fast speed semiconductor devices such as metal-semiconductor field effect transistor (MESFET), high electron mobility transistor (HEMT), heterojunction bipolar transistor (HBT) and the like because of its characteristic band structure and high electron mobility. Such a semiconductor device is constructed on a gallium arsenide wafer sliced from a gallium arsenide ingot grown as a single crystal or on a gallium arsenide substrate grown epitaxially on a surface of a silicon wafer. In the latter construction, one can avoid the difficulty of handling heavy and brittle gallium arsenide wafer during the fabrication process of the device by using a light and strong silicon wafer fabricated by a well established process for the base of the substrate. Further, one can easily obtain a large diameter wafer in such a construction. As a result, one can handle the wafer easily and reduce the manufacturing cost of the device. Further, such a wafer is suited for fabrication of a so called optoelectronic integrated circuit (OEIC) devices wherein gallium arsenide laser diode and the like are assembled together with silicon transistors on a common semiconductor chip.
When growing gallium arsenide on silicon wafer epitaxially, however, one encounters various difficulties. Such difficulties are caused mainly due to large difference in the lattice constant and thermal expansion between silicon and gallium arsenide. For example, the lattice constant of silicon is smaller than that of gallium arsenide by about 4% and the thermal expansion coefficient of silicon is smaller than that of gallium arsenide by about 230%. From simple calculation based on the difference in the lattice constant, it is predicted that the gallium arsenide substrate constructed as such contains dislocations with a density in the order of 10 12 /cm 2 . Thus epitaxial growth of gallium arsenide layer made directly on silicon substrate is usually unsuccessful. Even if successful, such a layer involves significant defects such that they cannot be used as the substrate for a semiconductor device.
In order to eliminate these problems and obtain a gallium arsenide substrate layer having a quality satisfactory for a substrate of semiconductor device, it is proposed to interpose a buffer layer between the silicon wafer and the gallium arsenide substrate so as to absorb any stress caused as a result of mismatch in the lattice constant and thermal expansion between the wafer and the substrate. In one example, a super lattice layer is used for the buffer layer wherein a plurality of crystal layers each containing a few layers of atoms and having its own lattice constant which is different from each other are stacked on the surface of the silicon wafer before the deposition of the gallium arsenide substrate. By doing so, propagation of defects into the gallium arsenide substrate layer is prevented. Unfortunately, the formation of such a super lattice structure requires an extremely precise control of the crystal growth which is difficult to achieve with reliability in the presently available technique.
Alternatively, it is proposed to interpose a polycrystalline gallium arsenide buffer layer between the silicon substrate and the gallium arsenide layer to absorb the mismatching of the lattice constant and thermal expansion. In this approach, a thin gallium arsenide polycrystalline buffer layer having a thickness of typically 10 nm is deposited on the silicon substrate at a temperature of about 400°-450° C. prior to deposition of the single crystal gallium arsenide substrate layer. Then, the temperature is raised to about 600°-750° C. and the gallium arsenide substrate layer is deposited for a thickness of about a few microns. When the temperature is raised from the first temperature to the second temperature, the polycrystalline gallium arsenide buffer layer is recrystalized into single crystal and the gallium arsenide substrate layer deposited thereon grows while maintaining epitaxial relation with the gallium arsenide buffer layer underneath.
In this technique, however, it is difficult to obtain a satisfactorily flat surface for the single crystal gallium arsenide layer. This is because the polycrystalline gallium arsenide buffer layer takes an island structure on the surface of the silicon wafer and the non-flat morphology of the surface of the polycrystalline gallium arsenide buffer layer is transferred to the gallium arsenide substrate layer provided thereon. In other words, the the surface of the gallium arsenide substrate layer becomes waved in correspondence to the island structure of the buffer layer. In spite of the use of reduced temperature at the time of formation of the buffer layer so as to suppress the formation of the island structure by reducing the growth rate, the island structure cannot be eliminated satisfactorily. Further, such a waved surface of the gallium arsenide substrate cannot be eliminated even if the thickness of the gallium arsenide layer is increased to a few microns or more.
Further, it is proposed to use other material such as silicon-germanium solid solution Si y Ge l-y for the buffer layer while changing the composition y continuously from the surface of the silicon substrate to the bottom of the gallium arsenide substrate layer as is described in the Japanese Laid-open Patent Application No. 62-87490. Alternatively, it is proposed to use a gallium arsenide based mixed crystal such as In x Ga l-x As or Al x Ga l-x As with a composition x of about 4.5×10 -3 for the buffer layer (Japanese Laid-open Patent Application No. 62-291909). In both of these alternatives, there is a problem in the surface morphology as already described.
On the other hand, the applicants made a discovery during a series of experiments to deposit a group III-V compound such as aluminium arsenide (AlAs) on a gallium arsenide substrate by atomic layer epitaxy (ALE) that aluminium deposited on an arsenic plane of the gallium arsenide substrate rapidly covers the surface of the substrate with a surface density corresponding to two or three molecular layers of the group III-V compound (U.S. Pat. application Ser. No. 172,671; Ozeki et al., J.Vac.Sci.Tech.B5(4), Jul/Aug. 1987 pp. 1184-1186). Further, it was found that there is a saturation or self-limiting effect in the deposition of aluminium arsenide. More specifically, there occurs substantially no additional deposition of aluminium after it is deposited on the surface of gallium arsenide for a surface density corresponding to two or three molecular layers of aluminium arsenide. In this study, however, it was not clear if such a self-limiting effect appears also when aluminium arsenide is deposited on the surface of silicon having diamond structure instead of the arsenic plane of gallium arsenide having zinc blende structure.
In the present invention, the applicants studied the hetero-epitaxial growth of group III-V compounds on silicon and discovered that epitaxial growth of a group III-V compound comprising at least one element having a strong affinity with silicon can successfully eliminate the formation of the island structure when the compound is grown on silicon in a form of alternating atomic layers of the component elements.
SUMMARY OF THE INVENTION
Accordingly, it is a general object of the present invention to provide a novel and useful method of growing a compound semiconductor layer on a wafer made of a single element and a semiconductor structure manufactured by such a method, wherein the problems aforementioned are eliminated.
Another and more specific object of the present invention is to provide a method of growing a substrate layer of a group III-V compound on a silicon wafer via a buffer layer of another group III-V compound for adjusting mismatch in the lattice between the substrate and the wafer, wherein formation of island structure in the buffer layer is effectively suppressed.
Another object of the present invention is to provide a method of growing a substrate layer of a compound semiconductor on a silicon wafer, comprising steps of depositing a buffer layer including a first element having strong affinity with silicon and a second element different from the first element such that the first element and the second element are stacked on the wafer in a form of alternating monoatomic layers, and growing the substrate layer including a component element having a less stronger affinity with silicon on the buffer layer. According to the present invention, the first element having the strong affinity with silicon covers the surface of the silicon wafer rapidly. Such a rapid coverage of the surface of the silicon wafer by the first element is particularly facilitated as a result of self-limiting effect when aluminium is chosen as the first element. As a result of the rapid coverage of the surface of the wafer, the formation of the island structure in the buffer layer is effectively suppressed and the formation of the waved surface of the substrate layer in correspondence to the island structure is effectively prevented.
Other objects and further features of the present invention will become apparent from the following detailed description when read in conjuction with attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematical view showing an apparatus used in the present invention for growing a gallium arsenide substrate on a silicon wafer via a buffer layer;
FIG. 2 is a graph showing a heat treatment employed in the present invention for growing the buffer layer and the gallium arsenide substrate layer on the silicon wafer;
FIG. 3 is a time chart showing a gas control sequence used for growing the buffer layer and the gallium arsenide substrate layer on the silicon wafer;
FIG. 4 is a graph showing a result of Auger electron spectroscopy conducted for evaluating the degree of coverage of surface of the silicon wafer by the buffer layer formed by the process of FIG. 3 in comparison with prior art corresponding structures;
FIG. 5 is a graph showing a result of Raman spectroscopy conducted for evaluating the quality of the surface of the gallium arsenide substrate layer obtained by the process of FIG. 3 in comparison with a prior art structure; and
FIGS. 6(A)-(D) are drawings showing steps for growing the buffer layer and the gallium arsenide substrate layer on the silicon (100) plane by atomic layer epitaxy as shown in FIG. 3.
DETAILED DESCRIPTION
FIG. 1 shows an apparatus used in the present invention for growing a group III-V compound substrate layer on a surface of a silicon wafer via an intervening buffer layer using ALE based on a metal-organic chemical vapor deposition (MOCVD) technique. In the embodiment described below, gallium arsenide is chosen as the group III-V compound and aluminium arsenide is used as the material for the buffer layer, as this material has a lattice constant and thermal expansion close to those of gallium arsenide to be grown thereon. Further, both of the compounds are polar compounds having ionic nature in the chemical bond. Because of these reasons, it is known that there is an excellent conformity when these two compound semiconductor materials are grown each other epitaxially.
Referring to the drawing, the apparatus has a chimney type reaction chamber 20 evacuated through a port 20a at its top, a susceptor 21 for heating a silicon wafer 22 held therein responsive to radio frequency excitation, a support pipe 23 for supporting the susceptor 21, an excitation coil 25 for generating the radio frequency excitation, a gas mixer 26 for introducing a gas or a gas mixture into the reaction chamber 20, gas supply valves 27a-27d for introducing various source and purge gases selectively into the reaction chamber 20, and a controller 28 for controlling the supply of the gases through the valves 27a-27d.
At the beginning of the process, the silicon wafer 22 is baked at a temperature of about 1000° C. as illustrated in FIG. 2 by "PHASE I" under a reduced pressure so as to remove oxide film or any contamination from its surface. The pressure of the reaction chamber 20 is maintained at about 20 Torr and hydrogen in total of 2 SLM is flowed through the chamber 20 throughout the entire process. After about 20 minutes of baking, the temperature of the wafer 22 is reduced to about 500° C. in a "PHASE II" of FIG. 2 and an aluminium arsenide buffer layer is grown on the surface of the wafer 22 by ALE.
FIG. 3 shows the sequence of gases introduced into the reaction chamber 20 during the PHASE II process. Referring to FIG. 3, a trimethylaluminium gas ((CH 3 ) 3 Al) referred to hereinafter as TMA is introduced first through the valve 27a with a flow rate of about 20 SCCM for 7.5 seconds using a bubbler temperature of 22° C. The TMA thus introduced is decomposed in the reaction chamber 20 and produces aluminium which covers the surface of the silicon wafer 22 as monoatomic layer as will be described later. Next, the TMA gas or any residual component species remaining after the deposition is purged from the reactor 20 by introducing hydrogen from the valve 27d for about three seconds. Next, an arsine (AsH 3 ) gas diluted by hydrogen to 10% concentration is introduced into the reaction chamber 20 from the valve 27b with a flow rate of about 480 SCCM for ten seconds. Arsine thus introduced is decomposed in the reaction chamber 20 to form arsenic to be deposited on the monoatomic aluminium layer on the surface of the silicon wafer 22. After the introduction of arsine, the arsine gas or any residual component species remaining after the deposition is purged from the reactor 20 by introducing hydrogen from the valve 27d. With this, one cycle of the gas sequence for the growth of the aluminium arsenide buffer layer is completed. It is estimated that arsenic produced as a result of decomposition of arsine is deposited on the monoatomic layer aluminium already deposited on the surface of the wafer and causes rearrangement of aluminium. Thereby, two or three molecular layers of aluminium arsenide is formed depending on the nature of the surface of the silicon wafer.
After this, the gas sequence is repeated until a desired thickness of the aluminium arsenide layer is grown on the surface of the silicon wafer 22. The thickness of the aluminium arsenide layer is chosen to be sufficient to relax the stress caused as a result of the mismatching in the lattice constant and thermal expansion between the silicon wafer and the gallium arsenide substrate. In one example, one hundred molecular layers of aluminium arsenide are grown by repeating the gas sequence. In this case, the gas sequence is repeated for fifty times.
Next, the temperature of the wafer 22 is raised to about 600° C. and a "PHASE III" of the process shown in FIG. 2 is commenced. In this phase, a gallium arsenide substrate layer is grown on the aluminium arsenide buffer layer on the silicon wafer by a suitable epitaxial growth technique such as the conventional MOCVD. In this process, it is not necessary to introduce source and purge gases selectively but the source gas for gallium and arsenic may be introduced simultaneously. In one example, a gallium arsenide layer of about 2-3μm is grown by supplying trimethylgallium ((CH 3 ) 3 Ga) referred to hereinafter as TMG and the arsine gas with a flow rate of 2 SCCM and 40 SCCM, respectively for about 2 hours.
FIG. 4 shows the result of Auger electron spectroscopy conducted on the surface of the silicon wafer 22 in the various steps for covering the surface by the aluminium arsenide buffer layer. In the drawing, the ordinate represents a relative intensity of Auger electron emitted from silicon atoms in the surface of the wafer which is covered totally or partially by the buffer layer with reference to a silicon wafer which is free from coverage by the buffer layer. In other words, the relative intensity of the Auger electron in the ordinate represents the degree of coverage of the surface of the silicon wafer by the buffer layer. When the value of the ordinate is one, it means that the surface of the silicon wafer is entirely exposed without coverage while when the value is zero, it means that the surface of the silicon wafer is completely covered by the buffer layer.
The abscissa of FIG. 4 represents the number of molecular layers of aluminium arsenide deposited on the surface of the silicon wafer 22. Thus, the continuous line designated as "ALE AlAs" in FIG. 4 shows that the surface of the silicon wafer 22 is covered almost entirely with the aluminium arsenide buffer layer after it is deposited for about 20 molecular layers. After the deposition of about 30 molecular layers of aluminium arsenide, it can be seen that the surface of the silicon wafer is totally covered by the buffer layer. This means that the surface of the silicon wafer is rapidly covered by the buffer layer without substantial formation of the island structure. The ideal coverage calculated based on perfect layer-by-layer growth of the buffer layer is represented in FIG. 4 by a dotted line designated as "LAYER GROWTH". It should be noted that the coverage of the surface represented by the line ALE AlAs is quite close to the case of the ideal coverage represented by the dotted line. In FIG. 4, the result obtained by a similar measurement for the case in which a conventional gallium arsenide buffer layer is deposited by a usual molecular beam epitaxy (MBE GaAs) is also presented by a broken line for comparison. It can be seen that, in this case, the coverage of the surface of the silicon wafer is still incomplete after the deposition of more than one hundred molecular layers. From this result, it is quite clear that there is a substantial formation of the island structure or clustering of gallium and arsenic at the surface of the wafer.
In FIG. 4, the result of the process described above is further compared with the case in which a gallium arsenide buffer layer is grown on the surface of the silicon substrate by the ALE (a continuous line designated as "ALE GaAs"). Even in comparison with this case, it is clear that the surface of the wafer is covered more rapidly when aluminium arsenide is used for the buffer layer.
FIG. 5 shows a result of evaluation of the surface of the gallium arsenide substrate grown on the aluminium arsenide buffer layer in comparison with a gallium arsenide substrate grown on a gallium arsenide buffer layer which in turn is grown on the surface of the silicon wafer by ALE. The evaluation is made by irradiating an argon-ion laser beam on the surface of the gallium arsenide substrate layer and observing a Raman scattering. In FIG. 5, the strong peak designated by "LO" corresponds to the Raman scattering attributed to the (100) plane of gallium arsenide while the more diffused peak indicated as "TO" corresponds to the presence of other planes of gallium arsenide and/or defects. It can be seen that only the (100) plane is observed in the case of the gallium arsenide substrate grown on the aluminium arsenide buffer layer indicating that the crystalline quality of the gallium arsenide substrate is sufficient, while distortion of crystal plane is observed when the gallium substrate is grown on the gallium arsenide buffer layer grown on the silicon substrate.
Next, the growth of the buffer layer and the substrate layer on the silicon wafer will be described with reference to schematical crystal structure diagrams of FIGS. 6(A)-(D).
Referring to FIG. 6(A), aluminium atoms formed as a result of pyrolysis of TMA in the phase II of FIG. 2 settle on the (100) plane of a silicon wafer I in a form of a monoatomic layer m as a result of its strong affinity to silicon. In the following description, the term affinity is used as a qualitative measure representing the degree of chemical bond or magnitude of heat of formation of a compound formed when two different elements are combined each other. Although the sites occupied by the aluminium atoms is still hypothetical, aluminium atoms are deposited with a surface density corresponding to two molecular layers of aluminium arsenide uniformly over the entire surface of the wafer I without causing clustering. Qualitatively speaking, this phenomenon means that aluminium is more stable when it is combined with silicon than it is clustered on the surface of the silicon wafer because of its strong affinity to silicon. Further, it was observed that there appears a self-limiting effect similarly to the case of deposition of aluminium on gallium arsenide as is reported previously by the applicants (U.S. Pat. application Ser. No. 172,671 by the present applicants), when aluminium is supplied beyond the surface density corresponding to the two molecular layers of aluminium arsenide, although such a self-limiting effect of aluminium on silicon having diamond structure is first discovered in the study which forms the basis of the present invention. Further, it was found that the density of aluminium is saturated at a value corresponding to three layers of aluminium arsenide molecules when it is deposited on the (110) plane of silicon similarly to the case of the ALE on the gallium arsenide (110) plane.
Next, arsenic atoms formed as a result of the pyrolysis of arsine is deposited on the aluminium monoatomic layer m. When the arsenic atoms reach the aluminium monoatomic layer m, the aluminium atoms are rearranged and there is formed the two molecular layers of aluminium arsenide as shown in FIG. 6(B) by a layer II. As the initial distribution of aluminium is uniform throughout the entire surface of the wafer I, there is no formation of the island structure in the layer II even if arsenic is deposited thereon. By repeating the supply of TMA and arsine with intervening purging by hydrogen as already described, the layer II is grown to a desired thickness and forms the buffer layer. In this layer II, the aluminium atom and the arsenic atoms are stacked alternately. After the formation of the buffer layer II, a gallium arsenide layer III is formed by an ordinary MOCVD as already described or by molecular beam epitaxy (MBE) as shown in FIG. 6(C). As the gallium arsenide has a lattice constant and thermal expansion which are almost identical to those of aluminium arsenide, there is no difficulty in the deposition of gallium arsenide on aluminium arsenide thus covering the surface of the silicon wafer. The overall structure of the gallium arsenide substrate thus obtained comprises the silicon wafer I, the aluminium arsenide buffer layer II and the gallium arsenide substrate layer III as shown in FIG. 6(D). As already described, the buffer layer II absorbs the stress caused as a result of mismatching in the lattice constant and thermal expansion between the wafer I and the substrate layer III. As the aluminium arsenide has a similar lattice constant and thermal expansion to those of the gallium arsenide, the gallium arsenide substrate layer III thus grown is almost free from defects and can be used for a substrate of the compound semiconductor device without problem.
Further, it was found that the growth of the buffer layer II may be made by depositing arsenic first on the silicon wafer and then depositing aluminium. In this case, the sequence of TMA and arsine is simply reversed from those of FIG. 3 without changing the duration or other conditions for the ALE. In this case, too, the formation of the island structure in the buffer layer is effectively suppressed and the obtained gallium arsenide substrate shows a flat surface. Although the mechanism of suppressing of the island structure in this case is not certain, one may suppose that arsenic in the first monoatomic layer on the silicon wafer distributes uniformly over the silicon wafer, and then aluminium is distributed uniformly over the arsenic monoatomic layer.
Further, the group V elements to be deposited on silicon as the component element of the buffer layer II is not limited to arsenic but nitrogen (N) and phosphorus (P) both having stronger affinity to silicon than gallium or arsenic constituting the substrate layer may be used as well. When such a group V elements are deposited, they are distributed uniformly over the surface of the silicon wafer by rapidly combining with silicon and the island growth of the buffer layer is suppressed. It should be noted that the order of deposition of aluminium and such group V elements in the buffer layer V during the ALE may be reversed similarly to the case of the ALE growth of the aluminium arsenide buffer layer. When using nitrogen or phosphorus as the group V element, ammonia (NH 3 ) or phosphine (PH 3 ) may be used as the source gas for these elements.
When the compound substrate layer to be grown on the silicon wafer is indium phosphide (InP) instead of gallium arsenide, it was found that compounds comprising elements such as aluminium, gallium and nitrogen having stronger affinity to silicon than indium or phosphorus constituting the substrate layer is suitable for the buffer layer II.
Further, the ALE of the buffer layer is not limited to those described which are based on MOCVD but molecular beam epitaxy may be used as long as the supply of the element can be made alternately. Furthermore, the growth of the substrate layer is not limited to MOCVD but conventional molecular beam epitaxy may be used as well.
Further, the present invention is not limited to these embodiments but various variations and modifications may be made without departing from the scope of the invention. | 4y
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FIELD OF THE INVENTION
[0001] The invention relates to the utilisation of fatty materials with substantial free fatty acid content in the production of biodiesel.
BACKGROUND OF THE INVENTION
[0002] As a result of the increasing interest in renewable resources in general and biofuels in particular, a number of processes has been developed for the production of esters of fatty acids and lower alkyl alcohols, which esters are also referred to as ‘biodiesel’. Early ‘biodiesel’ processes prescribed the use of neutral raw materials and thereby competed with food applications. Accordingly, there is an incentive to exploit cheaper alternative sources of fatty acid moieties as raw material for biodiesel production. This often means that such materials may contain free fatty acids and that their FFA contents can vary over a wide range.
[0003] Accordingly, U.S. Pat. No. 4,164,506 discloses a process comprising the esterification of free fatty acids of unrefined fats with a lower alcohol in an amount larger than its solubility in the fats in the presence of an acid catalyst. However, several lower alcohols have a boiling point that is lower than the boiling point of water which implies that it is impossible to remove the water formed by the esterification while retaining the lower alcohol in the reaction mixture. Shifting the esterification equilibrium to the ester side therefore requires the use of a large excess of lower alcohol.
[0004] This disadvantage can be overcome by using a high boiling alcohol such as glycerol as disclosed in U.S. Pat. No. 2,588,435. Using such high boiling alcohols has the additional advantage that the reaction can be carried out at a higher temperature, which increases the rate constant of the esterification reaction, without having to operate under superatmospheric pressure. In fact, as disclosed in U.S. Pat. No. 6,822,105, the esterification can now be carried out under vacuum, which promotes the evaporation of the water formed by the esterification reaction which is thereby shifted towards the ester side. The use of nitrogen during a vacuum stripping operation further facilitates the water evaporation.
[0005] However, as demonstrated by the examples in U.S. Pat. Nos. 6,822,105 and 7,087,771, the esterification reaction is quite slow and it can take some 7 to 11 hours before the acid value of the reaction mixture, which is indicative of the residual free fatty acid content, has decreased to a value below 0.4 (mg KOH per g oil), which in industrial practice is the maximum value for a starting material for a transesterification process leading to biodiesel. The example in US Patent Application Publication 2004/0186307 employing a solid esterification catalyst, which is present in a packed bed inside the esterification reactor, also mentions a reaction time of 5 hours at a temperature of 200° C. Holding fatty materials at such a high temperature for long periods of time can lead to the formation of unwanted side-products.
[0006] Accordingly, there is a strong preference for an esterification reaction at lower temperatures and for a catalyst that does not cause side-products to be formed. Operating a lower temperature can also lead to energy savings. In this context, the use of enzymes in general and of lipases in particular merits consideration. However, the use of enzymes is far from straightforward. Their activity depends on the water concentration but water also affects the position of the esterification equilibrium. Moreover, the reagents should be well mixed, which is why the literature often mentions the use of solvents, e.g. ref. Pastor, E.; Otero, C.; Ballesteros, A. 1994 Applied Biochemistry and Biotechnology Vol 50, p: 251-263: Synthesis of Mono-and Dioleylglycerols Using an Immobilized Lipase. For industrial processes the use of solvents raises the cost of operation and is therefore preferably avoided.
[0007] Accordingly, there is a clear need for an enzymatic process that allows fatty raw materials with variable free fatty acid contents to be utilised as raw material for biodiesel production.
OBJECTS OF THE INVENTION
[0008] Accordingly, it is an object of the invention to overcome the various disadvantages of the prior art processes for utilising fatty raw materials with a high free fatty acid content for the production of fatty acid esters of lower alkyl alcohols by the use of lipase enzymes.
[0009] It is another object of the invention to avoid the use of solvents.
[0010] It is also an object of the invention to use the lipase enzyme in such a way that its productivity is maximised.
[0011] It is a further object of the invention to enable the maximisation of the yield of lower alkyl esters of fatty acids based on the fatty acid moiety content of the raw material.
[0012] It is yet another object of the invention to provide a process that can accommodate a wide range of raw materials with varying free fatty acid contents.
[0013] These and further objects of the invention will become apparent from the description and the examples hereinafter.
SUMMARY OF THE INVENTION
[0014] It has surprisingly been found that there exist microbial enzymes that are effective in a solvent-free process for the production of esters of fatty acids and C 1 -C 3 alkyl alcohols from a fatty material containing free fatty acids, comprising the steps of:
(a) providing a reaction mixture that comprises free fatty acids, a lipase and one or more polyhydric alcohols; (b) allowing said reaction mixture to react under formation of esters of fatty acids and polyhydric alcohols until the free fatty acid content has decreased by more than a factor of 2; (c) separating the reaction mixture into a fatty phase and an alcoholic phase; (d) reducing the free fatty acid content of said fatty phase to an acid value below 2 (mg KOH per g) by subjecting it to a process of vacuum stripping or by blending it with a glyceride oil having an acid value below 2 (mg KOH per g), or by a combination of both; (e) transesterifying the fatty material resulting from step (d) with a C 1 -C 3 alkyl alcohol.
[0020] The process of the invention saves time in comparison with the prior art by no longer aiming for an almost complete esterification of the free fatty acids with the polyhydric alcohol but instead, makes use of the productive, first part of the esterification and after partial esterification, and reduces the residual free fatty acid content by a vacuum stripping process which is preferably combined with an existing physical refining operation or by a blending process.
BRIEF DESCRIPTION OF THE DRAWING
[0021] FIG. 1 is a flow diagram illustrating several different embodiments of the invention.
DEFINITION OF TERMS
[0022] The terms to be defined below are shown in capitals and have been listed alphabetically; if a definition contains a listed term, this term has been italicised.
ACID OILS is the fatty product that results from the acidulation of soapstock. Its composition varies but it is likely to contain more than 50% by weight of free fatty acids, the remainder comprising triglyceride oil, partial glycerides and unsaponifiables. ACIDULATION is the process used to recover the fatty matter contained in product streams comprising soaps such as soapstock. It involves adding an acid as for instance sulphuric acid, to this product stream and separating the fatty phase as acid oils from the aqueous phase. ALCOHOLYSIS is the reaction between an alcohol and a glyceride such as an oil or fat. If the alcohol concerned is methanol, the alcoholysis can also be referred to as ‘methanolysis’. BIODIESEL is defined as esters of long chain fatty acids derived from renewable feed stocks and C 1 -C 3 monohydric alcohols. Examples of such renewable feed stocks are vegetable oils and animal fats. In the context of the present invention long chain fatty acids may be defined as fatty acid chains with a length of between 10 and 22 carbon atoms. ESTERIFICATION is the reaction between a fatty acid and an alcohol leading to an ester and water. HYDROLYSIS is the reaction between an ester and water and is the reversible reaction of esterification. FATTY ACID DISTILLATE is the condensate resulting from a vapour scrubbing process during the vacuum stripping of triglyceride oils which latter process is used for the physical removal of free fatty acids and for the deodorisation of triglyceride oils. In addition to FFA, the fatty acid distillate contains unsaponifiables such as but not limited to tocopherols and sterols. FATTY FEED is a general name for raw materials containing fatty acid moieties. These can be glycerides such as monoacylglyceride, also referred to as monoglyceride, diglycerides, triglycerides and phosphatides but free fatty acids and even soaps can form part of the fatty feed. FFA is the standard abbreviation of Free Fatty Acids. SOAPSTOCK is the by-product of the chemical neutralisation of crude triglyceride oils. It comprises soaps, phosphatides and neutral oil besides many colouring compounds, particulate matter and other impurities as well as water containing various salts. STRIPPING, also referred to as vacuum stripping when carried out at subatmospheric pressure, is a process that causes the most volatile constituents of a mixture to vaporise when a gas is blown through the mixture. TRANSESTERIFICATION is another name for alcoholysis.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The process of the invention provides an economic and environmentally friendly alternative to the use of the acid catalysed esterification processes that are currently used; it also causes less corrosion and produces less salt by-products. Moreover, it can accommodate raw materials with widely different FFA contents. These can be crude or degummed oils and fats of vegetable or animal origin and preferably those that have such a high FFA content that their neutralisation by conventional means is uneconomic. High acidity rice bran oil is a prime example of such oils, but palm oil may occasionally also exhibit high FFA contents. In general, oils and fats that are used for the production of soap because their FFA content is too high for economic use as food, are suitable.
[0036] Suitable raw materials for the process of the invention also comprise inedible fatty feeds such as but not limited to inedible tallow, and by-products originating from edible oil processing such as acid oils, fatty acid distillate, greases and grease trap skimmings, etc. The FFA contents of the raw materials mentioned above can vary widely. Crude rice bran oil for example can have an FFA content of more than 10% or even more than 20% or even 30%. Fatty acid distillates originating from the physical refining process can contain in excess of 90% FFA; it is an advantage of the process of the invention that it can effectively handle all these raw materials. Although the term fatty acid distillate (terms used in FIG. 1 will be written in italics from hereafter) is too narrow a description of this wide range of raw materials, this is what the term is intended to cover in FIG. 1 .
[0037] FIG. 1 also shows that a non-neutral oil can be subjected to a vacuum stripping process to yield a neutral oil that has such a low FFA content that it is amenable to being transesterified with a C 1 -C 3 alcohol without excessive catalyst usage, and a fatty acid distillate that is a suitable raw material for the process of the invention. Such a non-neutral oil can refer to an oil that has been degummed to a low residual phosphorus level and that is then physically refined in the process that has been indicated as vacuum stripping.
[0038] According to the process of the invention the so-called fatty acid distillate is esterified with a polyhydric alcohol which FIG. 1 refers to as glycerol. This glycerol can originate from a number of different sources. During the alcoholysis or transesterification process shown in FIG. 1 , glycerol is formed as by-product of the biodiesel production. This glycerol will contain the most of the soaps formed during the alcoholysis by reaction of the alkaline catalyst with any FFA and/or water present in the feedstocks. Acidulation of this ‘soapy glycerol’ will convert the soaps into free fatty acids and sodium salts, the latter of which can be removed by filtration as indicated in FIG. 1 . Consequently, the use of the acidulated glycerol by-product stream from the transesterification in the esterification process of the invention recuperates the fatty acid moieties converted into soaps during said transesterification and ensures they are ultimately converted into biodiesel.
[0039] Another glycerol source for the process of the invention is the alcoholic phase resulting from the process of the invention. Utilising this source is especially advantageous since it contains the lipase enzyme and thus permits this enzyme to be recycled. Consequently, it is also advantageous to wash the fatty phase resulting from the process of the invention with a polyhydric alcohol such as but not limited to glycerol, and thereby recuperate residual amounts of enzyme. The washing step has been indicated in FIG. 1 , but the fact that the glycerol+FFA filtrate can be used for said washing purpose has not been shown.
[0040] In the esterification reactor, the molar ratio of hydroxyl groups in the polyhydric alcohol and the free fatty acids has to be controlled, but according to the process of the invention this ratio can vary between fairly wide limits. When glycerol is used as polyhydric alcohol, the molar ratio of glycerol to free fatty acids in the reaction mixture provided in step (a) of the process of the invention is preferably from 1:2 to 2:1. More preferably the molar ratio of glycerol to free fatty acids of the substrate feeding the enzymatic reaction is from 2:3 to 3:2. More preferably the molar ratio of glycerol to free fatty acids of the substrate feeding the enzymatic reaction is from 3:4 to 4:3. Most preferably the molar ratio of glycerol to free fatty acids of the substrate feeding the enzymatic reaction is approximately 1:1.
[0041] The biodiesel production process is a net producer of glycerol. Accordingly, the process of the invention requires a glycerol purge. In a preferred embodiment of the invention, this purge comprises a membrane filtration of the alcoholic phase that ensures that the lipase is retained, followed by the recycling of the retentate to the esterification step. The glycerol emerging as filtrate can then act as partially purified purge. The enzyme recovery and concomitant glycerol purification may be performed by any recovery method know to those skilled in the art e.g. centrifugation or membrane filtration.
[0042] The process of the invention employs a lipase enzyme as catalyst. Amongst the many microbial lipases that are now available, especially promising results have been obtained when using a carboxylic ester hydrolase (EC no 3.1.1), such as Candida Antarctica lipase B as the catalytic enzyme according to the invention. Normally, immobilised enzymes are preferably used in enzymatic processes, because of the reduced enzyme usage and thereby reduced costs. It has surprisingly been shown that the enzyme used in the esterification process according to the invention is effective without being immobilised and that it can be effectively isolated from the reaction mixture and recycled. By using enzymes free in solution an increased efficiency as well as increased yield may be maintained at low cost. Another benefit of not using immobilized enzyme is that the reaction media will consist of one phase less by only having a liquid fatty acid phase and a liquid glycerol phase, which need to be efficiently mixed. Consequently, in a preferred embodiment, the enzymes are liquid enzymes (i.e. enzymes that are free in solution), meaning that they are not actively immobilised on any solid support.
[0043] The amount of enzyme used is dependent upon the enzyme source and activity of the enzyme. The activity of lipases can be expressed in Lipase Units (LU) which is analyzed by measuring the amount of μmol titratable butyric acid per minute formed from tributyrin at 30° C. at pH 7. Typically, the enzyme is used in a concentration corresponding to 1 LU/g FFA to 1000 LU/g FFA. Preferably the enzyme is used in a concentration of between 5 LU/g FFA to 500 LU/g FFA, more preferably between 10 LU/g FFA to 100 LU/g FFA.
[0044] The optimum parameters for enzymatic activity will vary depending upon the enzyme used. The rate of enzyme degradation depends upon factors known in the art, including the enzyme concentration, substrate concentration, temperature, the presence or absence of inhibitors and presence of water. These parameters may be adjusted to optimise the esterification reaction.
[0045] During the enzymatic treatment step, the temperature of the suspension should be adjusted to provide effective enzyme activity. In general, a temperature of about 40° C. to about 90° C. is used, particularly from about 60° C. to about 80° C. In one embodiment the preferred temperature of the esterification reaction mixture is approx. 75° C.
[0046] During the enzymatic esterification according to the process of the invention, water is formed as a reaction product. In a preferred embodiment, this water is removed from the reaction mixture by applying a vacuum to the esterification reactor and/or by stripping its contents with an inert gas such as nitrogen or carbon dioxide. To save on the consumption of this inert gas, it can be circulated in a closed loop comprising a dryer. Superior results are obtained when a rotary jet head (EP1324818) is used to mix the stripping medium into the reaction mixture. The rotary jet head system is also providing efficient mixing of the fatty acid and the glycerol phase. To improve further the mixing of the two phases the reaction mixture can be added emulsifiers, e.g. mono-acyl glycerol and/or di-acyl glycerol. The emulsifier can be part of esterified FFA/glycerol from one batch being added to the next batch for esterification.
[0047] During the early stages of the esterification process, the rate of esterification is limited by the enzyme concentration and its activity. As and when the reaction proceeds and the concentrations of the free hydroxyl and carboxyl groups decrease, these concentrations start to become the rate limiting factors. Another factor decreasing the rate of formation of new ester bonds is the fact that the esterification reaction is reversible and leads to an equilibrium. Accordingly, in a preferred embodiment of the process of the invention, the esterification process is terminated when the productivity of the esterification (defined as the net number of ester bonds that is formed per unit of time) has fallen below a certain level, whereby the optimum of this level depends on local circumstances.
[0048] So instead of continuing the esterification process of the invention until the residual FFA content is so low that the reaction product can be transesterified without inactivating unduly high amounts of interesterification catalyst, a preferred embodiment of the invention halts the interesterification step (b) of the process of the invention when the FFA content of the reaction mixture has decreased by a factor of more than 2. If the FFA content of the reaction mixture provided in step (a) of the process of the invention is high and for instance more than 50%, the esterification can be profitably continued until the FFA content of the reaction mixture has decrease by a factor of more than 4 or even more than 8.
[0049] Consequently, the FFA content of the reaction mixture is likely to be too high for profitable transesterification leading to biodiesel, when the esterification process of the invention is halted. Instead and as illustrated in FIG. 1 , a fatty phase is isolated from the esterification reaction mixture and this fatty phase is then either subjected to a vacuum stripping treatment to reduce its FFA content or mixed with neutral oil to provide a blend with an FFA content below 1%, which is amenable to profitable transesterification and biodiesel production. These operations: vacuum stripping and blending, are additional treatments and thereby add to the cost of the process as a whole but if a vacuum stripping process is being operated on site anyway, processing a bit more involves only marginal costs, and blending is one of the cheapest if not the cheapest process being operated in the sector concerned.
[0050] Given the low price of blending, a preferred embodiment of the process of the invention comprises lowering the FFA content of the esterification reaction mixture to a value of 2 to 10% by vacuum stripping and subsequently lowering it further to 1% or lower by blending with neutralised oil. This has the advantage that only a small amount of monoglycerides will be lost during vacuum stripping and thus improves the biodiesel yield of the process of the invention. When the esterification mixture is mixed with high FFA oil to be vacuum stripped, no separate subsequent blending step is required.
Example 1
[0051] In this example, a palm oil fatty acid distillate with an FFA content of 90% was mixed with pure glycerol in a molar ratio of 1:1. The mixture was introduced into a stirred reactor held at a pressure of 5 mbar absolute, and kept at 68° C. CALB L lipase (liquid enzyme from Candida Antartica lipase B supplied by Novozymes A/S Denmark) was added in a concentration of 175 LU per g FFA. After 8 hours reaction, the FFA content had been reduced to 7% due to the formation of mono-, di- and triacylglycerides.
[0052] This example shows that the liquid enzyme from Candida Antartica is capable of reducing high levels of FFA within a reasonable period of time.
Example 2
[0053] In this example, the effect of the esterification temperature was investigated. The same palm oil fatty distillate and the same enzyme preparation were used as in example 1 and the FFA to glycerol ratio was again 1:1, but the enzyme dosage was only 100 LU per g FFA. After 8 hours reaction, the FFA content of the reaction carried out at 75° C. had dropped to 9% whereas when the reaction was carried out at the lower temperature of 58° c., the residual FFA content was higher at 15%. The experiment shows that operating at the higher of the two temperatures led to a larger extent of FFA esterification but the example does not indicate whether this difference is due to differences in enzyme activity or in water volatility.
Example 3
[0054] In this example, another lipase was tested. The same palm oil fatty distillate as used in example 1 was used and the FFA to glycerol ratio was again 1:1. The enzyme tested was Lipozyme TL IM, an immobilised enzyme from Thermomyces lanuginosus supplied by Novozyme A/S, Denmark; it was used in an amount of 4% by weight on oil. The reaction temperature was 68° C. and the reactor was kept at 5 mbar absolute. After 6 hours the FFA content of the reaction mixture had fallen to 79%.
[0055] This experiment shows that Lipozyme TL IM is not a suitable enzyme for the process of the invention.
Example 4
[0056] In this example, the effect of reaction time on conversion will be shown. A rapeseed oil fatty distillate with an FA content of 46% was mixed with glycerol in a molar ratio of glycerol to FFA of 1:1 and an amount of CALB L that was also used in example 1 was added in an amount of 175 LU per g oil FFA. The reaction temperature was 68° C. and the pressure inside the reactor was 5 mbar absolute. A sample take after 4 hours of reaction had an FFA content of 13% and after 8 hours of reaction it still contained 5% FFA.
[0057] This example shows that the esterification is quite rapid at the beginning, when the FFA content is still high but slows down considerably when the FFA content has dropped. This means that it can be advantageous to terminate the reaction well before such a low FFA content has been reached that blending with neutralised oil will bring this FFA content below a value that permits profitable transesterification. In general, the most profitable embodiment of the process of the invention comprises an esterification of the FFA in the fatty acid distillate to a residual FFA content of for instance about 10%, mixing with high FFA oil and vacuum stripping of the resulting mixture to yield a neutral oil that can be profitably interesterified. This embodiment combines: the high productivity first stage of the esterification step with vacuum stripping conditions that avoid the loss of monoglycerides.
Example 5
[0058] This example illustrates the beneficial effect of stripping the reaction mixture in step (b). The reaction mixture consiting of glycerol and oleic acid in ratio 33:77 w/w % was flushed with nitrogen during reaction at atmospheric pressure. C. antartica B liquid was used in dosage of 50 LU/g FFA and temperature 70° C. Sampling after 2 hours, 4 hours and 21 hours showed following conversions: 6%, 32%, and 89%, respectively.
Example 6
[0059] From 1000 Kg Palm oil with 5% FFA is obtained approximately 945 Kg FFA-low oil with low FFA content and approximately 55 Kg with high FFA (approx. 90%) content. After the reaction the FFA content of is reduced to e.g. 8% (as shown in example 1). Adding this directly back to the FFA-low oil will result in 1000 Kg of oil containing 4 Kg FFA equals 0.4% FFA in the product going to methanolysis, which fulfil the specifications for oil raw material for the methanolysis process, i.e. below 0.5%. | 4y
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FIELD OF THE INVENTION
[0001] This invention relates generally to a lanyard connector, more particularly to easy detachable three-part buckle with a system of elements for winding a string (cord) to eliminate the swinging effect.
BACKGROUND OF THE INVENTION
[0002] The connectors and buckles are commonly used to join the ends of belts, straps, bands and other such linear elements together. The buckles come in a variety of designs and have diverse characteristics such as being adjustable, quick-closing, and quick-opening. From among quick-opening or quick-release buckles, hook and loop fasteners are quite popular because they contain no metal, are generally immune to harsh treatment, and are resistant to most elements such as wind, rain, snow and the like. The buckles comprising two interlocking parts are well known (see U.S. Pat. Nos. 4,945,614; 5,311,649; 5,791,026; 5,832,573). The patents describe buckles having insert (male) and receptacle (female) parts.
[0003] U.S. Pat. No. 6,615,460 discloses a male/female-type buckle for belts and lanyards, wherein the insert member can be releasably inserted into the receptacle member and is locked in place be means of two resilient opposed lateral arms extending away from the center of the insert. The arms compress upon insertion, thereby providing a spring loading potential energy for their outward expansion. The arms move into locking slots on the body of the receptacle upon full insertion of the insert and spring out into the locked position within the slot.
[0004] The female part of such type of a buckle can be adopted to attach an accessory's string (eg. cell phone, USB flash, digital camera, ID cards etc.).
[0005] As a disadvantage, this type of buckle does not allow for adopting the length of the accessory's string, which results in undesirable swinging effect of the hung accessory.
[0006] U.S. Pat. No. 5,938,137 discloses a leash attached to the cell phone case and including a spring retractable leash cord in a housing pivotally attached to the belt that will prevent dropping and damage to a cell phone in a case clipped to the belt. The leash housing is pivotally attached to a locking belt hook that cannot easily be accidentally removed.
[0007] Though this type of clipping the cell phone partly eliminates the swinging effect of the hung cell phone, it makes a free manipulation with the cell phone more difficult. Further, the leash housing is exposed to a mechanical strain and thus also to detrition. This detrition dramatically increases when using inadequate pulling force, the real limit of which can very hardly be determined and is different for each user, but it causes an irreversible damage of the leash housing.
[0008] Further, it is known that the cords that are used for attaching the accessory to the buckle often have a metal ending, or also a small metal ring, by means of which they are attached to female members of buckles, thus increasing the material demands for their manufacturing.
SUMMARY OF THE INVENTION
[0009] This invention describes a detachable lanyard male/female-type buckle with a system of elements for winding a cord (string). It is an insert type of buckle and alike the other inventions, the inserting (male) member can be detachably inserted into the casing (female) member and fixed/locked by the protrusions of arms. Along with an inserting (male) member, the buckle according to this invention comprises a casing (female member) having a system of elements for winding a cord and a cover of casing.
[0010] The male member of the buckle consists of a central part—body—having flexible arms disposed on both its sides, which extend from the bottom end of the body upwards. The body of the insert member with arms is intended to be attached to the casing (female part) of the buckle.
[0011] The female member of buckle (casing) is designed as a shaped hollow housing having a circular section, and having one (upper) end open and the other (bottom) end closed.
[0012] The object of the invention is that the female member (casing) is in the upper end of the outer surface of the rear part equipped with a system of elements for winding a cord (string), which comprises a hanging element for attaching the cord of the accessory (e.g. cell phone, MP3 player, USB flash, digital camera, etc.), a peg ended with extended part and preferably a centring element for central fixing of the hung cord, which is situated in the bottom end, under the peg. Further, in the rear part of the casing there are two openings for inserting the shaped protrusions of flexible arms, and shaped fixing protrusions, which are situated next to the outer sides of the openings and serve for attaching the casing to the cover.
[0013] In another aspect of the invention, the casing is equipped with a cover with openings for inserting the shaped fixing protrusions of the rear part of the casing, which fixes the position of the cord (string). Also, on its bottom part the casing has a groove for guiding the cord and preferably the lateral grooves to facilitate opening of the cover in case of need for handling the cord.
[0014] In yet further aspect of the invention, the shaped hanging element with openings for lanyard, situated in the upper end of the male member (insert part) of the buckle, is preferably equipped with a flat element for opening the casing cover (a small lever).
[0015] As stated above, the male member of buckle consists of the central part—body—having flexible arms disposed on both its sides, which extend from the bottom end of the body upwards. The body of the insert member with arms is intended to be attached to the casing (female part) of the buckle.
[0016] On the upper part of the body of the insert member there is a shaped hanging element with an opening, serving for hanging the buckle on the lanyard, which can be together with the buckle preferably worn on the neck or wrist, as well as on the arm.
[0017] On its rear part the body is equipped with a longitudinal guide protrusion, which serves for providing a continual movement of the insert member and should prevent an incorrect inserting of the body with arms into the casing of the buckle. The flexible arms of the insert member are equipped with shaped “locking” protrusions, which are situated opposite to each other in the rear part of flexible arms.
[0018] The female member of buckle is designed as a shaped hollow housing having a circular section, and having one (upper) end open and the other (bottom) end closed. On the inner side of the front part there is a shaped guiding groove for inserting the body of the insert member, and on the inner side of the rear part there is a guiding groove for inserting the longitudinal protrusion of the body of the insert member.
[0019] In the rear part of the casing there are two openings for inserting the shaped protrusions of flexible arms. The surface between these openings and the guiding groove is shaped so as to facilitate guiding of the shaped protrusions of flexible arms and for their fixing.
[0020] After putting the insert (male) member into the grooves of the casing and its pressing inwards the casing, the arms move towards the body. When inserting the arms into the casing, the lateral surfaces of the shaped protrusions get into contact with lateral surfaces of the shaped surface of casing and when the inserting continues, the flexible arms are pressed further towards the body. When the insert part reaches the necessary depth, the pressed flexible arms return to their original position, the shaped protrusions snap in the relevant openings in the rear part of the casing, and by their upper surfaces they get into contact with the bottom surfaces of the shaped surfaces, thus providing attachment of the insert member to the casing.
[0021] After a standard attachment of the cord, which is part of the buckle, to the cell phone (or other type of accessory), the loop of the opposite end is hung on the hanging member of the casing. Preferably, the cord can be shortened to the desired length by its multiple winding on the peg, which is ended by an extended part, preventing the sliding of the cord from the peg. Further, under the peg there is preferably situated a centring member, serving for central positioning and fixing of the hung cord, thus eliminating a possibility of penetrating the cord (string) between the casing and the cover after closing the casing, as well as preventing an undesireable opening of the cover and subsequent slipping of the cord from the peg and hanging element by an uncareful handling.
[0022] After hanging and winding the cord to the system of elements for winding, a cover is attached to the casing, wherein the cord is put in the groove in the bottom part of the cover, thereby fixing the position of the cord. The cord can be shortened to a minimal length, thus maximally eliminating the swinging effect, and in order to conveniently handle the “accessory” it is sufficient to detach the female member from the male member. Moreover, the cord does not contain any further elements (e.g. metal or plastic end-pieces), thereby the manufacturing is simplified and material demands of the whole buckle are decreased.
[0023] By pressing the casing cover the shaped fixing protrusions move towards the central axis and subsequently reach the openings, thereby fixing the cover. When the cover reaches the desired site, the shaped protrusions return to the original position and fix the cover.
[0024] After opening the casing cover it is possible to freely handle the cord. The cover is opened simply—the male member is pulled out of the casing, the flat element is inserted in one of the grooves on the side of the cover and the cover is detached from the casing by soft levering.
[0025] The buckle is typically molded from a polyoxymethylene (POM), but it can also be made from other thermoplastic material. The aesthetic value of the buckle is increased also by the fact that the male member and female member will be available in various two-colour combinations and in graphical harmony with the impress on individual lanyards.
[0026] The advantage of the buckle according to the present invention is that it allows for winding the excessive length of the cord on the peg of the casing, thus eliminating the swinging effect when hanging the accessory on the cord. Even if a minimal length of the cord disturbes the overall impression, the solution according to the invention allows for enclosing the whole length of the cord in the casing. In such a case the function of the solution is increased by an aesthetic design of the buckle.
[0027] Moreover, after hanging the buckle on the lanyard the flat element for opening the cover is overlapped.
DESCRIPTION OF THE DRAWINGS
[0028] In the drawings which illustrate preferred embodiments of the invention
[0029] FIG. 1 is a prospective view on the insert (male) member of the buckle,
[0030] FIG. 2 is a prospective view on the casing (female member) of the buckle,
[0031] FIG. 3 is a prospective view on the cover of casing of the buckle,
[0032] FIG. 4 is a side view on the casing,
[0033] FIG. 4A is a front view on the inner side of the rear part of the casing shown in FIG. 2 ,
[0034] FIG. 4B is a front view on the inner side of the front part of the casing shown in FIG. 2 ,
[0035] FIG. 5 is a rear prospective view on the rear part of the casing shown in FIG. 2 with winded string (cord),
[0036] FIG. 6 is a rear prospective view on the assembled buckle with cover,
[0037] FIG. 7 is a front view on the front side of the insert (male) member shown in FIG. 1 ,
[0038] FIG. 8 is a front view on the front side of the casing of the buckle,
[0039] FIG. 9 is a front prospective view on the assembled buckle.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0040] The embodiment of the buckle according to the present invention will further be described with reference to the attached drawings.
[0041] The buckle according to the present invention, showed in the unassembled state in the prospective view in FIGS. 1 , 2 and 3 , is an insert type buckle and it consists of the insert member (male member) A, casing (female member) B and cover C of casing. The insert (male) member A ( FIG. 1 ) is intended to be inserted to the casing (female member) B ( FIG. 2 ) with cover ( FIG. 3 ). It is made from the polyoxymethylene (POM), but it can also be made from other thermoplastic material, in various colours, including combinations of colours.
[0042] The insert member A (male member) of the buckle consists of body 2 having flexible arms 3 disposed on both its sides, which extend from the bottom end of the body 2 upwards. The body 2 of the insert member A equipped with arms 3 is intended to be attached to the casing B of the buckle after its inserting in guiding grooves of the casing—in guiding groove 6 of the front part and guiding groove 7 of the rear part. On the upper part of the body 2 of the insert member A there is a shaped hanging element 1 with opening 1 . 1 , which (opening) serves for passing the lanyard and hanging the buckle. On body 2 of the casing, approximately in the middle, there is preferably a shaped couple of protrusions 2 . 2 , which define movement of shaped arms 3 towards body 2 when inserting in the casing and pulling from it, as well as one longitudinal guiding protrusion 2 . 1 on the rear part of the body 2 , which provides for a continuous movement of the insert member and prevents from an incorrect inserting of body 2 with arms 3 in casing B of the buckle. In the longitudinal guiding protrusion 2 . 1 there can be a shaped longitudinal recess 2 . 1 . 1 for decreasing friction during inserting.
[0043] The flexible arms 3 of insert member A are equipped with shaped “locking” protrusions 4 , which are situated opposite each other in one level on the rear part of flexible arms 3 .
[0044] When inserting the arms 3 into the casing 2 the lateral surfaces 4 . 1 of the shaped protrusions 4 get into contact with lateral surfaces 9 . 1 of the shaped surfaces 9 of casing 2 and when the inserting continues, the flexible arms 3 are pressed further towards the body 2 . When the insert part A reaches the necessary depth, the pressed flexible arms 3 return to their original position, the shaped protrusions 4 snap in the relevant openings 8 in the rear part of the casing 2 , and by their upper surfaces 4 . 2 they get into contact with the bottom surfaces 9 . 2 of the shaped surfaces 9 , thus providing attachment of the insert member A to the casing B. A correct position of the insert member in the casing can also be identified according to the position of embossed protrusions 17 ( FIG. 7 ) in the front part of arms 3 , which are in case of a correct insertion visible as “eyes” in the openings 18 ( FIG. 8 ) in the front part of the casing B ( FIG. 9 ).
[0045] The parts are detached by pressing the flexible arms 3 towards body 2 and pulling the insert part A from casing B.
[0046] The casing B is designed as a shaped hollow housing having a circular section. On the inner side of the front part there is a shaped guiding groove 6 for inserting the body 2 of the insert member, and on the inner side of the rear part there is a guiding groove 7 for inserting the longitudinal protrusion 2 . 1 of the body 2 of the insert member. Further, in the rear part of the casing there are two openings 8 for inserting the shaped protrusions 4 of flexible arms 3 , and between openings 8 and guiding groove 7 there is a shaped surface 9 for guiding and fixing the shaped protrusions 4 of arms 3 .
[0047] On the outer part of the rear part the casing B is equipped with shaped fixing protrusions 13 , which are situated next to the outer sides of the openings 8 and serve for attaching the casing B to the cover C ( FIG. 2 ). The front part of the casing is preferably equipped with openings 18 ( FIG. 8 ), which can not only control a correct position of arms 3 of insert member together with a shaped beak-like element 19 and protruding ends of arms 3 , but they also have an aestehetic function: after attaching the insert member to the casing they form a buckle in the shape of “duck”.
[0048] Moreover, the casing B (female member) is in the upper end of the outer surface of the rear part equipped with a system of elements for winding a cord, which comprises a hanging element 10 for attaching the cord 20 with the accessory (e.g. a cell phone), a peg 11 ended with extended part 11 . 1 and preferably a centring element 12 for central fixing of the hung cord 20 . This centring element 12 is situated in the bottom end, under the peg 11 . Further, in the rear part of the casing there are two openings 8 for inserting the shaped protrusions 4 of flexible arms 3 , and shaped fixing protrusions 13 , which are situated next to the outer sides of the openings 8 and serve for attaching the casing B to the cover C.
[0049] The casing B comprises cover C with openings 14 for inserting the shaped fixing protrusions 13 of the rear part of the casing. By pressing the cover C the shaped fixing protrusions 13 are inclined towards the central axis and they are directed to pass through the openings 14 . When the cover gets into its position and the protruding elements as well as the cord 20 are overlapped, the shaped protrusions 13 get into their original positions and fix the cover C.
[0050] Also, on its bottom part the casing has a groove 16 for guiding the cord 20 and preferably the lateral grooves 15 to facilitate opening of the cover in case of need for handling the cord. The cover is opened simply—the male member is pulled out of the casing, the flat element 5 of male member is inserted in one of the grooves 15 and the cover is detached from the casing by soft levering.
Buckle
LIST OF REFERENCE CHARACTERS/SIGNS
[0000]
A insert (male) member of buckle
1 hanging element of insert member
1 . 1 opening of hanging element
2 body of insert (male) part (of buckle)
2 . 1 longitudinal guiding protrusion of rear body part
2 . 1 . 1 recess of guiding protrusion
2 . 2 lateral protrusions of body
2 . 3 bottom protrusion
3 flexible (shaped) arms
4 shaped protrusions of arms
4 . 1 lateral surface (of shaped protrusions 4 )
4 . 2 upper surface (of shaped protrusions 4 )
5 flat element (for cover opening)
17 flat embossed protrusions of front part of arms
B casing (female part) of buckle
6 guiding groove of front part
7 guiding groove of rear part
8 openings of rear part of casing (for protrusions 4 )
9 (inner) shaped surface of casing
9 . 1 lateral surface of shaped surface 9
9 . 2 bottom surface of shaped surface 9
10 hanging element (of casing)
11 peg (for string)
11 . 1 extended part of peg
12 centring element
13 shaped/fixing protrusions
18 openings of front part of casing
19 beak shaped element of front part of casing
cord (string)
C cover of casing
14 openings of cover
15 lateral grooves (of cover)
16 groove (for cord/string) | 4y
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This is a division of application Ser. No. 95,171 filed on Dec. 4, 1970, and now abandoned.
BACKGROUND OF THE INVENTION
The invention relates to apparatus for manufacturing power transmission belts, but more particularly, the invention relates to apparatus for curing or vulcanizing of such belts.
It is normal practice to build a belt sleeve by plying together superimposed layers of various materials. The belt sleeve includes a first layer of uncured rubber over which is placed a tensile reinforcement of spirally wound cord. A second uncured rubber layer is superimposed over the cord. The belt sleeve is then cured under heat and pressure.
Various methods and apparatus have been devised which devote special attention to the tension section during curing or vulcanization. One such method is taught by U.S. Pat. No. 2,573,642 as issued to Hurry. Another method and apparatus that gives attention to the tension section, is taught by U.S. Pat. No. 3,398,218 as issued to Richmond. Both Hurry and Richmond teach methods for curing belts which have a tensile reinforcement that is variable in length. Under the Hurry method, the tensile reinforcement is stretched as the rubber layers are pressured into the mold. Under the Richmond method, a radially inward differential pressure is first applied to a belt body which somewhat compresses the tension section. Then an outward radial pressure is applied against the belt body as a blowing agent disposed within a rubber material expands.
It has been found that these and similar methods are satisfactory for manufacturing power transmission belts having customary tensile reinforcement which may be either stretched or shrunk tolerable amounts. Tensile reinforcements falling within this category include cotton, rayon, nylon and polyester. But in recent years, industry has created a demand for power transmission belts or higher power transmission capability. The demand established the need for a stronger or higher modulus tensile reinforcement. However, known tensile reinforcements of higher modulus, such as fiber glass and steel, are relatively inextensible and unshrinkable. Another high modulus reinforcement is an aromatic-polyamide sold under the trademark Nomex by DuPont. The unextensible properties of such reinforcements prevents proper curing pressure to be applied to both rubber layers of the belt sleeve during curing or vulcanizing by known methods. For manufacturing reasons, fiber glass cord is preferred over steel cord. However, fiber glass must be carefully handled because it is severely damaged if compressed. Compression loading of the tensile reinforcement is inherent in some known belt sleeve curing methods such as Richmond.
SUMMARY OF THE INVENTION
In accordance with the invention, it has been found that high modulus tensile reinforcements may be successfully used when special consideration is given when applying pressure to the belt sleeve or belt body during curing. Pressure must be individually applied to both rubber layers of the belt sleeve or body while simultaneously keeping the tensile reinforcement under tension. When a fiber glass tensile reinforcement is used, it is extremely important that the reinforcement never be subjected to a compressive load. To accomplish the desired pressure control, a mold having inner and outer plyable walls is used. An outward radial pressure is applied to the belt body or belt sleeve by a first plyable wall of the curing chamber. Afterwards, a lessor inward radial pressure is applied to the belt body or belt sleeve by means of a second plyable wall member while simultaneously applying heat in sufficient quantity to cure the rubber layers of the belt sleeve.
It is therefore a principle object of the invention to provide an apparatus for manufacturing power transmission belts which have a substantially inextensible tensile reinforcements.
It is another object of the invention to provide an apparatus for curing power transmission belt sleeves by controlling differential pressure as applied to the first and second rubber layers of the belt sleeve.
Another object of the invention is to provide an apparatus for curing power transmission belts having fiber glass tensile reinforcements whereby the possibility of compressing and damaging the fiber glass is avoided.
Yet another object of the invention is to provide an apparatus for making an improved power transmission belt having a fiber glass tensile reinforcement.
Still another object of the invention is to provide an apparatus for curing power transmisstion belts to attain good adhesion between the rubber layers of the belt and an essentially inextensible tensile reinforcement sandwiched therebetween.
It is another object of the invention to provide a means for applying sequenced inward and outward radial pressure to a belt sleeve during curing thereof.
A further object of the invention is to provide an apparatus to accomplish the above objects.
These and further objects and advantages of the invention will become apparent upon review of the drawings and description thereof wherein:
FIG. 1 is a sectional side view of the apparatus.
FIG. 2 is a partial view of FIG. 1 illustrating the relationship between pressure regulating members of the apparatus and a belt sleeve.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring to the drawings, a curing mold 10 of preferably cylindrical shape is provided. The mold 10 includes inner 12 and outer 14 cylindrical assemblies that are essentially concentric. The outer assembly 14 includes a supporting outer cylinder 16. Upper 18 and lower 20 end rings are attached to each end of the outer cylindar 16. The lower end ring forms a base for the mold. Each end ring is made of two separate concentric rings, 22-24, 26-28 that are held together by fasteners 30. The rings define upper 32 and lower 34 annular grooves. The upper ring 18 is coaxial with the lower ring 20. Together, the rings 18 and 20 define a guide which concentrically aligns and receives the inner assembly 12. A heavy rubber type diaphragm 36 or bladder of cylindrical shape is mounted between the upper 18 and lower 20 end rings. The bladder 36 extends into the upper 32 and lower 34 annular grooves and seals with the end rings. The bladder 36, end rings 18 and 20 and outer cylinder 16 define a sealed low-pressure heat chamber 38 of variable volume. A conduit 40 is attached to the outer cylinder 16 over an aperture 42. The conduit 40 directs heat and pressure to the low-pressure chamber 38 from an external source. Preferably, a second conduit 44 is attached to the outer cylinder 16 over a second aperture 46, the purpose of which will be later explained.
The inner assembly 12 is similar to the outer assembly in many respects. The inner assembly 12 includes a supporting inner cylinder 48. Upper 50 and lower 52 coaxial end rings are attached to each end of the inner cylinder 48. Each inner ring includes two separate concentric rings, 54-56, 58-60, that are held together by fasteners 62. The concentric rings define upper and lower annular grooves 64 and 66. A heavy rubber type inner diaphragm 68 or bladder of cylindrical shape is mounted between the upper 50 and lower 52 end rings. The bladder 68 extends into the annular grooves 64 and 66 and is held in place by the fasteners 62. The inner bladder 68, end rings 50 and 52 and inner cylinder 48 define a sealed high-pressure heat chamber 70 of variable volume. Upper 72 and lower 74 end caps slip over the upper 50 and lower 52 end rings respectively. The end caps are secured to the assembly by means of a bar 76 which attaches to the lower end cap 74 and extends through the upper end cap 72. The bar 76 has a hole or slot 78 near the upper end cap, through which is fitted a wedge or drift pin 80. The wedging action of the drift pin tensions the bar 76 and holds the end caps 72 and 74 firmly in place. The outside diameters of the end caps 72 and 74 are slightly less than the inside diameter of outer concentric rings 18 and 20. The close diameters of the end caps 72 and 74 and outer end rings 18 and 20 facilitate concentric alignment between the inner 12 and outer 14 assemblies. The inner cylinder 48 is provided with a hole 82 for receiving one end of a conduit 84. The conduit 84 directs heat and pressure to the high-pressure chamber from an external supply source. Preferably, a second hole 86 is located in the inner cylinder 48 for receiving an end of a second conduit 88.
Power transmission belts to be cured with apparatus of the invention are first built up in the usual manner as a belt sleeve. The belt sleeve typically includes a first rubber layer, a spirally wound tensile cord, and a second rubber layer. The axial length of the belt sleeve should be slightly less than the axial distance between the upper and lower end caps. The inside diameter of the belt sleeve should be slightly larger than the outside diameter of the upper ring 54 of the inner assembly 12. The pitch diameter of the tensile cord varies approximately five percent in an uncured belt sleeve because of normal manufacturing tolerances. The variation results from allowable tolerances for a belt building drum, mold and the thickness of the rubber layers. Prior art methods of curing belt sleeves accommodate the tolerance build-up by shrinking or stretching the tensile cord to either a larger or smaller pitch diameter. This invention is primarily directed toward curing belts having essentially non-extensible tensile cords such as metal, Nomex and especially fiber glass. Fiber glass is essentially non-extensible and it is severely weakened if subjected to compressive forces.
To cure a belt sleeve in accordance with the invention, the inner assembly 12 is first removed from the mold. The drift pin 78 is removed which permits dismantling of the upper end cap 72. A belt sleeve or body 90 may then be positioned over the inner diaphragm or bladder 68. The upper end cap 72 and drift pin 78 are replaced and the inner assembly 12 is repositioned in the mold. Heat and pressure are directed to the high pressure chamber by means of the inner conduit 84. Preferably, the heat and pressure source is steam. Normally, steam at 170 psig and 375° Fahrenheit is supplied for average size belt sleeves. Steam condensate is removed from the high pressure chamber 38 by means of the second conduit 88. The pressure expands the inner diaphragm 68 and exerts outward radial pressure against the belt sleeve 90. The belt sleeve or body inward 92 of the tensile reinforcement 94 is compressed which tensions the tensile reinforcement or cords 94. Further expansion of the inner-bladder 68 is restrained by the tensile reinforcement 94. Here, it should be noted that inner-diaphragm 68 adjusts to the free pitch circumference of the tensile renforcement 94 to accommodate dimensional variations as induced in manufacturing the uncured belt sleeve 90.
Outward radial pressure on the belt sleeve 90 compresses the inner rubber layer 92 and tensions the reinforcement 94. Compressive forces are not transmitted to the outside rubber layer 96 at this time because of the non-extensibility of the tensile or cord reinforcement 94. The portion of the belt sleeve outward 96 of the tensile reinforcement 94 must be compressed to insure proper adhesion with the tensile reinforcement 94. After a time delay of approximately one-half minute, steam at 140 psig and 360° Fahrenheit is directed through the outer conduit 40 to the low pressure chamber 38. The time delay insures a positive pressure differential between the inner 70 and outer 38 chambers during the pressure transients. The pressure contracts the outer diaphragm 36 radially inward which in turn compresses the outer rubber layer 96 radially inward against tensile reinforcement 94. Steam condensate is removed from the low-pressure chamber by means of the second conduit 46. Thus, a differential pressure of approximately 30 pounds per square inch is maintained radially outward across the belt sleeve to insure positive tensioning of the cord reinforcement 94 during curing of the rubber layers. When the curing cycle is completed, heat and pressure to the low-pressure chamber 38 is terminated. After a time delay, heat and pressure to the high-pressure chamber 70 is terminated. The pressure delay sequence is desirable when manufacturing belts with fiber glass tensile cords because it insures a positive pressure differential for tensioning the cords during the pressure decay transient. The cured belt sleeve is then removed from the mold for cutting into separate power transmission belts of desired cross section.
The time required to cure a belt sleeve is dependent upon the type of rubber material being cured, the mass of the rubber material and the curing temperature. In general, the curing cycle is completed when the mass of material has been heated between 15 and 90 minutes. When considering the time required to cure the belt sleeve, the heat transfer characteristics of the bladders 36 and 68 must be considered. Heat must be transferred across the bladders 36 and 68 to the belt sleeve. Characteristically, the elastomeric bladders cannot conduct heat as rapidly as a metal. A time delay factor to transfer heat across the bladders must be added to the cure cycle. It has been found that it takes approximately 10 minutes to transfer the necessary heat across an elastomeric bladder 0.28 inch thick.
The upper 72 and lower 74 end caps being of metal have a higher heat capacity than the bladders. Under some plant manufacturing conditions, for example, low surrounding temperatures, the end caps may drain heat near the belt sleeve ends faster than heat can be supplied across the bladders. In such a situation, the ends of the belt sleeve would not be usable as they would be under-cured. Optionally, the entire mold may be placed in an autoclave and the autoclave may then be heated. The pressure within the autoclave must be maintained at a level lower than the pressure of the high 70 and low 38 pressure chambers. Otherwise, a proper pressure differential could not be maintained across the belt sleeve.
For comparative purposes, belts having generally non-extensible reinforcements were constructed and cured by standard methods and by the method in accordance with the invention. Belts made by the older method of shell mold curing displayed different failure patterns. Belts made with only the portion of the rubber layer radially inward of the tensile reinforcement under pressure during the curing cycle failed early. Belts having a fiber glass reinforcement which were subjected to even slight compressive forces also failed early.
Care was taken to construct an uncured belt sleeve to exacting tolerances for curing in a typical shell mold. In shell mold curing, one side of the belt sleeve is in contact with a metallic cylindrical surface and the other side is in contact with an elastomeric bladder. The belt sleeve was built for a "glove" fit into the shell mold in effort to insure that some compression would be maintained on the belt sleeve on either side of the reinforcement. In an accelerated test, belts of the shell mold cure technique displayed a mean operating life of 173 hours. Belts of the same type were built and cured in accordance with the method of the invention. Under the same accelerated test, belts of the invention displayed a mean operating life of 308 hours or in other words, an improvement of 78 percent. It is readily seen that belts made by the method of the invention are superior to those belts of the same construction, but which were cured by other methods. The superior belt is a product of the method of the invention and not due to the physical details of belt construction.
The above method and apparatus may also be used for curing power transmission belts having an extensible reinforcement although the invention has been primarily described in relation to belts having non-extensible tensile cords.
The foregoing detailed description was made for purpose of illustration only and is not intended to limit the scope of the invention which is to be determined from the appended claims. | 4y
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to mobile devices that are equipped with positing unit (for example GPS) and capable of data communications. This invention is in particular related to delivering alerts to vehicle drivers via their mobile devices, such as smart phone and tablet, in order to notify them about traffic ahead.
[0003] 2. Description of the Prior Art
[0004] In today's world, many people own and carry GPS-enabled mobile phones. Due to the e911 mandate, wireless carriers must be able to locate a 911 mobile-phone caller to within 50 to 300 meters of accuracy. Various technologies have been used to satisfy this mandate including embedded GPS hardware in mobile phones. The implementation of such positioning technologies has led to the creation of a class of software application known as Location-Based Services (LBS) that use the device's location in coordination with other data to create location-aware applications.
[0005] In-vehicle technologies and safety related systems are a growing area of research and product development. The use of in-vehicle safety technologies has been developing and growing for decades. Over the years, there have been numerous evaluations of ITS (Intelligent Transportation Systems) technologies for safety applications. For example, there have been a number of evaluations of the speed limiting and alerting technology known as Intelligent Speed Adaptation (ISA).
[0006] Slow traffic ahead alert systems falls under the category of Active Safety Systems. An active safety system is an in-vehicle system that provides warnings or other forms of assistance to drivers based on information about the motion of self vehicle and other vehicles, obtained from object detection sensors mounted on the vehicles. Active safety systems are divided into two classes: Hard and Soft. A hard active safety system is for fast reaction in the order of a few seconds (2-3 seconds or so) like safety system deployed on high-end cars such as Cadillac, BMW, Lexus, etc that warn drivers about lane departure, lane change blind spot, rear-end collision, etc. Soft active safety systems are situational-awareness functions that provide alerts to drivers on driving conditions within a relatively short-latency time horizon, in the range of 10-60 seconds. An example of these systems is a mobile-phone based slow traffic ahead alert system. Such a system enables drivers to take tactical actions to avoid crashes, or in essence, increase their safety alert time horizon to beyond the just several seconds provided by hard safety systems. In these situations, by offering a timely “slow or stopped traffic ahead” message, the system can effectively inform drivers of roadway hazards or give speed advisories to reduce the chance of collisions. This safety application is similar to a successful implementation of vehicle-infrastructure concept in Tokyo, Japan in recent years.
[0007] To enable a Mobile-phone based traffic ahead alert system, phone communicates with a server to exchange information. These data include but not limited to time, vehicle location, speed, moving direction, and similar information for downstream traffic.
SUMMARY OF THE INVENTION
[0008] Object of the present invention is to provide a data exchange protocol to enable mobile device based traffic ahead alert systems. In this kind of alert system, a software application, Client, runs on the phone that exchanges data with one or more Servers. Data that are uploaded to the server(s) include but not limited to time, vehicle location, speed, and moving direction which are updated normally every second. Server sends to the Client location and speed of downstream traffic. Vehicle location changes rapidly at high speed, for example at 40 m/s (˜90 mph) vehicle travels 40 meters in just one second. Thus if motion of the vehicle is not modeled, Client should send to the server raw data sampled as fast as every second. The present invention presents a scheme that reduces the sampling rate significantly, at least 80%.
[0009] In one aspect, a method is provided of exchanging vehicle location information. At intervals, at one or more vehicles, sensor information is input including at least vehicle location information. An estimation process is performed for estimating at sub-intervals at least vehicle location to obtain estimated vehicle data. A subset of the vehicle data is selected and sent to a remote server. A client-side modeling process is performed for modeling at least vehicle location using the subset of vehicle data to obtain modeled vehicle data. The estimated vehicle data and the modeled vehicle data are compared to obtain comparison results. The comparison results are used to select the subset of vehicle data to be sent to the remote server. The vehicle may receive from the remote server other vehicle data for multiple other vehicles. At the vehicle, the other vehicle data may be used to model at least vehicle location for each of the multiple other vehicles. The vehicle may also receive from the remote server local traffic alert information. A server-side modeling process may be performed for modeling at least vehicle location using the subset of vehicle data to obtain modeled vehicle data, with the same model being used by both the client-side modeling process and the server-side modeling process. The foregoing steps may be performed at many different vehicles.
[0010] In another aspect, a system is provided for exchanging vehicle location information, including one or more servers; a communication network; and a plurality of in-vehicle systems carried by a plurality of vehicles. Each in-vehicle system includes one or more navigation sensors or receivers configured to, at intervals, output sensor information including at least vehicle location information. A processor is provided for performing an estimation process for estimating at sub-intervals at least vehicle location to obtain estimated vehicle data. The processor selects a subset of the vehicle data and sends the subset of vehicle data to a remote server. It also performs a client-side modeling process for modeling at least vehicle location using the subset of vehicle data to obtain modeled vehicle data, and compares the estimated vehicle data and the modeled vehicle data to obtain comparison results. Using the comparison results, the processor selects the subset of vehicle data to be sent to the remote server. The one or more servers may be configured to send to respective ones of each of the vehicles other vehicle data for vehicles in a vicinity of that vehicle. The processor at each of the plurality of vehicles may be configured to use the other vehicle data to model at least vehicle location for each of the other vehicles in the vicinity of that vehicle. The one or more servers may be configured to send to respective ones of each of the vehicles local traffic alert information for that vehicle. The system one or more servers may be configured to perform a server-side modeling process for modeling at least vehicle location using the subset of vehicle data to obtain modeled vehicle data, with the client-side modeling process being the same modeling process as the server-side modeling process.
[0011] In another aspect, an in-vehicle system is carried by a vehicle for exchanging vehicle location information. One or more navigation sensors or receivers are provided and configured to, at intervals, output sensor information including at least vehicle location information. A processor is provided and configured for performing an estimation process for estimating at sub-intervals at least vehicle location to obtain estimated vehicle data, and for selecting a subset of the vehicle data and sending the subset of vehicle data to a remote server. The processor is configured for performing a client-side modeling process for modeling at least vehicle location using the subset of vehicle data to obtain modeled vehicle data, and for comparing the estimated vehicle data and the modeled vehicle data to obtain comparison results. The processor is configured to use the comparison results to select the subset of vehicle data to be sent to the remote server. A receiver may be provided for receiving from one or more servers other vehicle data for multiple other vehicles. The processor may be configured to use the other vehicle data to model at least vehicle location for each of the other vehicles. The receiver may be configured to receive from the one or more servers local traffic alert information. The one or more servers may be configured to perform a server-side modeling process for modeling at least vehicle location using the subset of vehicle data to obtain modeled vehicle data, with the client-side modeling process using the same model as the server-side modeling process.
IN THE DRAWINGS
[0012] FIG. 1 is block diagram showing the system with one client and one server;
[0013] FIG. 2 is block diagram showing server component of the system;
[0014] FIG. 3 is block diagram showing the overall system with multiple clients and one server;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] FIG. 1 represents a block diagram embodiment of the present invention, and is referred to herein by the general reference numeral 100 . Major components of the system are the Navigation sensors 101 , the Client software running on the phone 102 , data cellular network 103 , and the Server 104 .
[0016] The Client 102 gets time and location data from the navigation sensors 101 periodically, normally every second. The Navigation sensors include a GPS receiver or equivalent positioning unit; other sensors such as accelerometer, compass, gyro, etc may also be used. Measurements of the Navigation sensors 101 are processed by the Self Estimator 111 to calculate states of self vehicle (SV) at time k and k+1, which k is index of time. Self Estimator 111 estimates position, speed, and heading of the vehicle using an estimation method, like Kalman filtering estimation (wikipedia.org/wiki/Kalman_filter); these quantities collectively constitute the vector {right arrow over ({circumflex over (X)} (k), which is the best available estimate of the state of the vehicle at time k. Time difference between k and k+1 is fixed and equal to the time interval between GPS measurements. For the rest of the discussion, we refer to {right arrow over ({circumflex over (X)} (k) of the Self Estimator 111 as the state of the vehicle at time k.
[0017] The Remote Estimator 112 keeps a copy of the most recent information the Client 102 has stored in the Data Storage 116 regarding its own motion. The Remote Estimator 112 operates first order kinematics model to provide the Scheduler 113 with estimates of SV states at time k+1 given in fact only the information that SV broadcasts to the Server 104 via the Cellular Network 103 . The equations for the kinematics model are as follows:
[0000] {tilde over (X)} ( k +1)= {tilde over (X)} ( k )+ {tilde over (V)} ( k )×cos({tilde over (Φ)} ( k ))×Δ T;
[0000] {tilde over (Y)} ( k +1)= {tilde over (Y)} ( k )+ {tilde over (V)} ( k )×sin({tilde over (Φ)} ( k ))×Δ T;
[0000] {tilde over (V)} ( k +1)= {tilde over (V)} ( k );
[0000] {tilde over (Φ)}( k +1)={tilde over (Φ)}( k )+{dot over ({tilde over (Φ)}( k )×Δ T;
[0000] {dot over ({tilde over (Φ)}( k +1)={dot over ({tilde over (Φ)}( k );
[0018] The state vectors {right arrow over ({circumflex over (X)}(.), {right arrow over ({tilde over (X)}(.) consist of positions X, Y (in the universal GPS coordinate frame with a local origin), speed V, and heading angle Φ. Symbols with (̂ ) on top refer to the Self Estimator's 113 estimates and symbols with (˜) on top refer to the Remote Estimator's 112 estimates.
[0019] The Neighbor Estimators 114 receive messages from the Server 104 via the Cellular Network 103 . These messages contain the states of the neighborhood traffic, including downstream traffic and/or vehicles that are in the neighborhood of SV. The Neighbor Estimators 114 comprises of several Neighbor Estimators 115 , each operating first order kinematics model to provide SV with estimates of states of Neighborhood traffic for times in-between message receptions from the Server 104 . We keep the model simple because each vehicle may need to operate many Neighbor Estimators, depending on traffic flow conditions.
[0020] Let the Remote Estimator 112 of vehicle i be denoted by RE i . Let the Neighbor Estimator 115 run by neighbor j for vehicle i be denoted NE ji . The purpose of RE i is to estimate the output of all the NE ji 's.
[0021] Whenever SV receives a message, it updates the relevant parameters in the Neighbor Estimators 114 to reflect the values provided in the transmitted message. The outputs of the vehicle Self Estimator 111 and the Neighbor Estimators 114 drive the traffic alert applications.
[0022] A vehicle's decision to store the states in the Data Storage 116 at any time instance is made by the Scheduler 113 . The Scheduler 113 receives inputs from both the Self Estimator 111 and the Remote Estimator 112 . It uses equation below to calculate the longitudinal and lateral position errors. These errors are defined below.
[0000] ε long. ( k )=|( {tilde over (X)} ( k )− {circumflex over (X)} ( k ))×cos({circumflex over (Φ)}( k ))−( {tilde over (Y)} ( k )− Ŷ ( k ))×sin({circumflex over (Φ)}( k ))|
[0000] ε lat. ( k )=|( {tilde over (X)} ( k )− {circumflex over (X)} ( k ))×sin({circumflex over (Φ)}( k ))+( {tilde over (Y)} ( k )− Ŷ ( k ))×cos({circumflex over (Φ)}( k ))|;
[0023] At time k, if ε long. (k+1) or ε lat. (k+1) exceed their respective thresholds, SV broadcasts {right arrow over ({circumflex over (X)}(k) as specified by the following policy:
[0000] u ( k )=1
[0000] if
[0000] (ε long. ( k +1)> Tr. long. ε lat. ( k +1)> Tr. lat. )
[0000] u ( k )=0 Otherwise
[0000] where,
k, is the time index, u(k), is the scheduler's decision on communication at time k (1 means communication and 0 means no communication) ε long. (.) is longitudinal tracking position error, ε Lat. (.) is lateral tracking position error, Tr. long. , is the threshold on the longitudinal error, Tr. lat. , is the threshold on the lateral error.
[0030] The two lateral and longitudinal position errors are configured depending on type of the application, for example for Slow Traffic Ahead alert application, values these thresholds may be 10 meters and 100 meters, respectively.
[0031] Client 102 periodically or at random times transmits data in the Data Storage 116 to the Server 104 . After each data transmission, the Data Storage 116 is cleared, i.e. stored data are erased.
[0032] FIG. 2 represents a block diagram embodiment of the present invention for Server component of the system, and is referred to herein by the general reference numeral 200 . Major components of the Server 201 are the Clients' Estimators 211 , External Traffic Data 212 , and Neighborhood Traffic Data 213 . The Server 201 receives data from Clients regarding their location, speed, etc data. As explained in first part of this section, these data are selected samples of outputs of the Self Estimators 111 . The Clients' Estimator 211 operates the same kinematics model equations that the Remote Estimator 112 does to provide the Neighborhood Traffic Data 213 with estimates of Clients' states at all times. The Neighborhood Traffic Data 213 also receives traffic data from external sources, for example Google Traffic. When a Client transmits data to the Server 201 , the Neighborhood Traffic Data 213 sends back to it local traffic information; such as speed of downstream traffic for the next ˜5 kilometers, incident information along route, etc.
[0033] FIG. 3 represents a block diagram embodiment of the overall system, and is referred to herein by the general reference numeral 300 . As shown in this diagram, at any time “n” number of Clients 301 , 302 , . . . may exchange data with the Server 305 via the Cellular Network 304 . | 4y
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a divisional of U.S. application Ser. No. 11/105,801 filed on Apr. 14, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates generally to the field of puzzles, and more particularly to the manufacture of customized jigsaw puzzles.
[0004] 2. Description of Related Art
[0005] Public photographic vending machines are well known in the prior art. These machines typically include cameras which can take photographs of individuals sitting in the machine or booth. These photographs are developed by the machine and dispensed to the individual. More modern photographic vending machines include systems that are able to produce a photographic montage using an image of the user in combination with a stored image selected by the user.
[0006] There is consumer interest in personalized jigsaw puzzles which include an image or a modified image chosen by the consumer. For example, French patent application FR 2,653,350 (published Apr. 26, 1991) describes a process for creating a jigsaw puzzle from a photograph. The photograph is glued to a cardboard sheet, and then the photograph and the cardboard sheet are pressed together and then are cut into pieces to form a jigsaw puzzle. Unfortunately, the production of individual cardboard jigsaw puzzles is generally not economically feasible, primarily due to equipment costs, as such puzzles are mass-produced and cut using giant industrial presses. A flourishing business still exists for hand-cut personal and custom puzzles, as is evidenced by various web sites that offer this service. These mainly use photographs glued to plywood that is then cut with either scroll saws or water jets.
[0007] WO 98/42420 (Japanese published Oct. 1, 1998) describes a jigsaw puzzle constructing vending machine. The machine captures a picture of an individual and permits the picture to be combined with a selected background. It may be overlaid with text, and morphing and retouching are suggested. The modified picture is then printed onto cardboard. The central portion of the cardboard is then cut out, leaving a surrounding cardboard frame, and the central portion is cut into puzzle pieces having curved but non-interlocking borders. The puzzle pieces are then dispensed. The surrounding cardboard frame is mounted on a backing and is dispensed separately, so that the cardboard pieces may be assembled within the frame by a child. Examples of materials to be used for the jigsaw puzzle sheet are listed and include paper (cardboard), wood (stain sheets), synthetic resins (soft and hard material), synthetic material, stone materials, woven fabrics, non-woven fabrics, cork, metals, leather and glass.
SUMMARY OF THE INVENTION
[0008] In at least one of the described embodiments, the invention relates to a method and apparatus for producing a customized jigsaw puzzle. The apparatus comprises an image capturing mechanism, such as a camera, that captures one or more images of one or more individuals, animals, or objects or combinations of these posed against a background. A computer that is linked to the mechanism and to a printer is programmed to print an image on flexible sheets having a printable surface. Then a press, having a platen carrying a jigsaw puzzle cutting die, when activated uses pressure to laminate together the flexible sheet bearing the printed image and a foam sheet thicker and more rigid than he flexible sheet, setting pressure responsive adhesive material used as a binder to form a laminated product, and substantially simultaneously to cut the laminated product into jigsaw puzzle pieces. Additionally, the apparatus may be provided for producing a custom puzzle using selecting means for selecting a first digital image containing at least two layers of images, within a bank of digital images and digital image capturing means for capturing a second digital image of subject individuals, animals, or objects. Further image processing means provide for integrating the second digital image between the at least two layers of the first digital image to obtain a composite image and puzzle production means for producing the custom puzzle with the digital composite image.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a plan view of a site showing a jigsaw puzzle machine designed in accordance with an embodiment of the invention in relation to a person or other subject that is to be photographed.
[0010] FIG. 2 shows a schematic view of a screen shot of a computer screen, according to an embodiment of the invention, illustrating the selection of a background scene for use in the design of a jigsaw puzzle.
[0011] FIG. 3 presents a perspective view of a child being photographed in front of a blue background, according to an embodiment of the invention.
[0012] FIG. 4 shows a schematic view of a screen shot of a computer screen, in accordance with an embodiment of the invention, illustrating the construction of a composite image having three layers.
[0013] FIG. 5 is a schematic view of a layout of a hard copy printout, according to an embodiment of the invention, printed on flexible paper and including both a puzzle picture and also a smaller picture, a bar code, and licensing information that is to be attached to the box which will contain the puzzle.
[0014] FIG. 6 presents a perspective view of a first flexible sheet bearing a puzzle picture being placed upon the pre-glued surface of a second sheet made of foam, in accordance with an embodiment of the invention.
[0015] FIG. 7 is a perspective view of a jigsaw puzzle resulting after pressure is applied to set the adhesive and to force a puzzle die against the laminated sheets to cut them into puzzle pieces.
[0016] FIG. 8 is a perspective view of custom packaging prepared in accordance with an embodiment of the invention.
[0017] FIG. 9 is a perspective view of a part of a jigsaw puzzle machine designed according to an alternate embodiment of the invention different from that shown in FIG. 1 .
[0018] FIG. 10 shows a flow chart illustrating the steps of a method for producing a custom jigsaw puzzle in accordance with one embodiment of the invention.
[0019] FIG. 11 shows a flow chart illustrating the steps of a method for producing a custom jigsaw puzzle, in accordance with another embodiment of the invention.
[0020] FIG. 12 shows a flow chart illustrating the steps of a method for producing a custom made package in accordance with another aspect of the invention.
[0021] FIG. 13 presents a schematic flow diagram of the entire process of producing customized puzzles, with many elements represented by block diagrams.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0022] Referring to FIGS. 1 , 2 , 3 , 4 , 6 , 7 , and 13 , a jigsaw puzzle machine 20 ( FIG. 13 ) is disclosed. The jigsaw puzzle machine 20 can produce a custom jigsaw puzzle 30 ( FIG. 7 ) for a user from a composite image 22 ( FIGS. 4 and 13 ) that is a combination of an image of a subject person 24 (FIGS. 1 and 3 —the subject may also be a pet or a toy or some other object) with at least one stored image 34 ( FIG. 2 ), the composite image 22 being shown in FIG. 4 .
[0023] More particularly, the present invention is embodied in a jigsaw puzzle machine 20 which includes a programmed computer 43 that permits one to select a first digital stored image 34 containing at least two layers of images 36 , including background scenes 23 and foreground objects 25 (as shown in FIGS. 2 and 13 ), within a bank of digital images 38 . The machine 20 further includes digital image capturing means 40 (such as a camera or scanner or data port) for capturing a second digital image 42 of a person or other subject 24 . The machine 20 also includes image processing means 44 implemented using a computer 43 programmed with a layered image creation and printing program 41 for integrating the second digital image 42 between the at least two layers 36 of the first digital stored image 34 to obtain a composite image 22 (as shown in FIG. 4 ). The machine 20 also includes puzzle production means 46 ( FIG. 1 ) for producing the custom jigsaw puzzle 30 bearing the digital composite image 22 . Included in the puzzle production means 46 , and with reference to FIG. 13 , are a printer 53 which prints the composite image 22 onto a flexible sheet 48 , a puzzle cutting die 80 resting on a surface 78 , and either a platen 78 or a roller 82 arranged to apply pressure to laminate the printed flexible sheet 48 on to a foam backing sheet 50 that is pre-coated with adhesive 59 and to cut the laminated sheets into a jigsaw puzzle. The puzzle production means 46 also includes a stack of the foam sheets 51 and a supply of the flexible sheets 55 that feeds the printer 53 , as is shown in FIG. 13 .
[0024] A programmed computer 43 and a program 41 to assist one in selecting a first digital stored image 34 within a bank of digital images 38 cooperate with digital image capturing means 40 (such as a camera or photograph scanner or computer port for receiving digital image data from a camera or portable storage device or camera) which captures a second digital image 42 of a person or other subject 24 . Image processing means 44 in the form of a layered image creation and printing program 41 (such as Adobe's® Photoshop®) enable an operator to integrate the second digital image 42 into the first digital stored image 34 to produce a composite image 22 that may be printed on a flexible sheet 48 . Jigsaw puzzle production means 46 (see FIGS. 1 and 13 ) including the printer 53 and an apparatus for producing pressure (either platens 76 and 78 or the platen 78 and a roller 82 shown in FIG. 13 ) that laminates the sheet 48 onto a sheet 50 made of foam and that causes a puzzle die 80 to cut the laminated sheets 48 and 50 into puzzle pieces to produce the puzzle 30 ( FIG. 7 ).
[0025] The first sheet 48 , when pressure is applied, becomes attached to an adhesive coated 59 surface of the second sheet 50 which is made of foam (as is shown in FIG. 6 ). The foam sheets are pre-coated with the adhesive and are heated to set the adhesive, since the adhesive is thermally activated. The pre-coated sheets of foam are then stacked at 51 for convenient storage before use.
[0026] The image processing means 44 may include a memory 45 in which are stored pre-established parameters upon which the integrating of the images is based. It also includes a computer 43 provided with a keyboard and mouse 57 and a display 49 and programs 41 that can display the layered images and permit the operator to manipulate the composite image 22 and its layered elements 36 and 42 .
[0027] Referring to FIG. 9 , the jigsaw puzzle machine 20 in one embodiment (different from that shown in FIG. 1 ) may have an external housing 52 that covers the jigsaw puzzle production means 46 , the external housing 52 including movable parts 54 (to entertain any children) and an exit 56 . The jigsaw puzzle machine may also include a motor for moving the movable parts 54 , a sound generator for generating interesting machine sounds, a conveyer that conveys the finished custom jigsaw puzzle 30 from inside of the housing 52 to the waiting child or adult through the exit 56 , and a button 58 for activating the motor, the sound generator and the conveyer from outside of the housing 52 . In an embodiment of the invention, the housing 52 is modular and takes only 3 hours to assemble. A child goes to the housing 52 and presses a button 58 that triggers the production process during which some parts 54 at the base of the housing 52 move about while making machine sounds. In an embodiment of the invention, a small door 64 opens on one side of the jigsaw puzzle production means 46 , and a sound can be heard as packaging containing the custom jigsaw puzzle 30 is dropped through the opening 56 . The whole jigsaw puzzle production process can be accomplished within a relatively short period of time, in the order of minutes.
[0028] Referring to FIG. 6 , the foam sheet 50 may be made of a polyethylene foam having a thickness of at least 3 mm (non-toxic polyethylene foam or foam for a Perfalock™ System). The foam may be LD60, weighing 2.5 pounds per square meter when the sheets are 3 millimeters thick. The puzzle is cut out of an 11 inch by 17 inch sheets. In the case of the thin, flexible sheets 48 , the grain is parallel to the long dimension, and this is why the sheets are 11 by 17, rather than 17 by 11. This paper has a semi-gloss finish, suitable for ink jet color printing. During the puzzle manufacturing process, these sheets are cut down to 14 by 11 for adult puzzles, which can have 200 to 300 pieces. The 3 inch portion of the sheet not cut up into puzzle pieces can be used for generating box labelling, as will be explained. In the case of children's puzzles, the puzzles may be cut to considerably smaller sizes and the puzzle pieces may be cut larger, so that only 30 pieces are cut out. Different puzzle dies are provided which give these different results. The pre-glued surface 59 may be provided with a glue of a type which remains flexible after setting, thereby permitting the puzzles to bend without pieces falling out. The adhesive is preferably pressure sensitive hot melt adhesive.
[0029] Referring now to FIGS. 4 , 5 , 6 , the printing means can be a printer 53 that prints at least one additional, reduced size, copy 60 of the composite image 22 onto the first sheet 48 for use as a customized box label.
[0030] In one embodiment, and referring now to FIGS. 1 , 2 , and 3 , the digital image capturing means 40 comprises a digital camera arranged to capture the second digital image 42 of the person or other subject 24 in front of a uniformly coloured screen 62 . A child or person can select the specific image in which the child or person wants to be positioned, as if the child or person or pet or other object (a teddy bear, for example) is part of a scene with a cartoon character or in a movie scene or in any other scenery or image, using a multi-layer digital compositing technique. The machine 20 may include the selecting means 32 that aids the customer in selecting from storage the first digital image 34 which normally contains foreground objects 25 and background scenes 23 and also the image processing means 44 which combines a selected background scene 23 and a foreground object 25 with the second digital image 42 of a person or other object 24 , these means being implemented by the programmed computer 43 shown in FIG. 1 as a “Laptop” and also shown in FIG. 13 . The display 49 and keyboard and mouse 57 of the computer 43 may be used to grant user approval of the generated composite image 22 for use in designing the custom jigsaw puzzle 30 .
[0031] The person or other subject 24 may be placed in front of a uniformly coloured screen 62 (usually blue or green) with a defined pre-positioning of the person or other subject 24 so that the subject person 24 seems to interact with the stored image 34 or forms an integral part of the stored image 34 . In an embodiment of the invention, a child or a person is photographed in a pre-selected position matching a situation in the stored image 34 . A preset process allows a quick and effective photo shoot on the blue screen background 62 . Every scene has its own very simple process for capture of the photo. The photo will be taken in a store or shopping mall location or in any other location with public traffic.
[0032] In an embodiment of the invention, the selecting means 32 and the image processing means 44 that generate the composite image 22 are implemented by means of a programmed computer 43 (see FIG. 13 ) which generates the composite image 22 , typically a 3-layered digital composite image 22 . The computer 43 uses computer programs 41 , such as Photoshop™, AdvantEdge™, any other similar program, to sandwich the image 42 of the person or other object 24 in between the components (typically a background scene 23 and one or more foreground objects 25 ) or layers of the stored image 34 (the first image) to form the layered composite image 22 which is printed on one of the flexible sheets 55 that forms the upper surface 59 of the custom puzzle 30 .
[0033] In an embodiment of the invention, a photographer/technician transfers the composite image 22 from the computer 43 to a high resolution printer 53 located within the jigsaw puzzle production means 46 . The high resolution printer 53 or a colour photocopier produces a print containing different sections (shown in FIG. 5 ). These include one bigger size image 22 for use as the face of the puzzle. Also included is a smaller image of the child in the puzzle setting for use as a label for the puzzle box. Additional box label information may be printed out. Thus, if the background scene 23 or any foreground objects 25 are licensed images, the copyright notice and the terms of the license may need to be printed out on the puzzle box. Ant to facilitate the gathering of accounting information to track royalty payments, a UPC bar code 74 may have to be printed out and studied. Note that all image sizes and die-cut jigsaw puzzle sizes are subject to vary and change, depending on the die line of the jigsaw puzzle.
[0034] In one embodiment of the invention, the jigsaw puzzle production means 46 provides means for transferring the larger hardcopy version of the composite image 22 and pre-glued foam sheet 50 (shown in FIG. 6 ) to a press or roller machine. The press's platens 78 and 76 ( FIG. 12 ) may squeeze the puzzle die against the foam sheet 50 and the printed image sheet 48 . The puzzle die has a Masonite™ base one-half inch thick into which puzzle grooves are cut, and then metal strips are pushed in to the grooves to do the cutting. A hard rubber pad is then squeezed into the die and cut so that it fills the spaces between the metal strips and enables great force to be applied to the laminated layers. As an alternative to a press, and requiring considerably less force to develop high pressure, a roller 82 may be mounted over the lower platen 78 and die 80 . In one arrangement, the platen 78 is mounted on rollers and rolls under the roller 82 which compresses the two sheets together in a manner similar to an old fashioned clothes ringer. Since pressure is applied along a thin line, rather than over a large area all at once, considerably less downward force is needed when the roller 82 is used than when two platens 76 and 78 and a press (not shown) are used.
[0035] In one embodiment of the invention, the jigsaw puzzle production means 46 also includes means for affixing on generic packaging for each custom jigsaw puzzle one of the at least one smaller hardcopy version 60 of the composite image 22 on a predetermined location on the packaging, as well as means for inserting the fully die cut jigsaw puzzle pieces into the packaging and means for closing the packaging containing the custom jigsaw puzzle. The technician affixes on generic packaging for each personalized jigsaw puzzle a small copy 60 of the composite image 22 on a predetermined location on the packaging. Other smaller images can also be generated as backups for the packaging, or alternately they may be inserted into the box to serve as a colour reference to facilitate jigsaw puzzle assembly. Any legal information 72 , including licence information and copyright notices, any logos and trade-marks 72 related to the use of licensed images in the jigsaw puzzle can also be affixed on a predetermined location on the packaging, as well as a UPC code 74 related to the custom jigsaw puzzle. The technician then inserts the fully die cut jigsaw puzzle pieces into the package which is closed and ready to come out of the jigsaw puzzle production means 46 to be taken home. And as noted above, the bar code allows full automation of the count of each puzzle sold to serve as a basis for royalty payments.
[0036] According to the invention, as shown in FIG. 10 , there is provided a method for producing a custom jigsaw puzzle, comprising steps of:
[0037] a) selecting 102 a first digital stored image containing at least two layers of images, within a bank of digital images;
[0038] b) capturing 104 a second digital image of a person or other subject;
[0039] c) integrating 106 the second digital image between the at least two layers of the first digital stored image to obtain a composite image 22 ; and
[0040] d) producing 108 the custom jigsaw puzzle with the digital composite image 22 .
[0041] Step d) can include the steps of:
[0042] printing a first copy of the composite image 22 onto a first sheet;
[0043] securing the first sheet onto a pre-glued surface 59 of a second sheet made of foam, to obtain a double sheeted member; and
[0044] die cutting the double sheeted member to obtain the custom jigsaw puzzle.
[0045] Step c) can include the step of storing pre-established parameters upon which the integrating is based.
[0046] Step c) can further include the steps of displaying the composite image 22 on the display 49 and manipulating the composite image 22 .
[0047] In step d), the second sheet can be made of a polyethylene foam having a thickness of at least 3 mm.
[0048] In step d), the pre-glued surface 59 may be provided with a glue of a type which remains flexible after setting thereof.
[0049] In step d), the glue may be pressure sensitive hot melt adhesive.
[0050] Step d) can include the step of printing at least one additional copy 60 of the composite image 22 onto the first sheet, the at least one additional copy 60 being smaller than the first copy 22 .
[0051] In step b), the person or other subject 24 may be positioned in a predetermined position in the second digital image 42 to match a situation determined by the at least two layers of the first digital stored image 34 .
[0052] Step b) involves capturing a third digital image of another person or other subject, and step c) involves integrating the third digital image between the at least two layers of the first digital stored image within the composite image 22 .
[0053] According to the invention, as shown in FIG. 11 , there is also provided a method for producing a custom jigsaw puzzle, comprising steps of:
[0054] a) selecting 112 a first digital stored image, within a bank of digital images;
[0055] b) capturing 114 a second digital image of a person or other subject;
[0056] c) integrating 116 the second digital image into the first digital stored image to obtain a composite image 22 ; and
[0057] d) producing 118 the custom jigsaw puzzle on a sheet made of foam with the composite image 22 .
[0058] Step d) comprises the steps of:
[0059] printing a first copy of the composite image 22 onto a first sheet;
[0060] securing the first sheet onto a pre-glued surface 59 of a second sheet made of foam, to obtain a double sheeted member; and
[0061] die cutting the double sheeted member to obtain the custom jigsaw puzzle.
[0062] Step c) may include storing pre-established parameters upon which the integrating is based.
[0063] Step c) can involve displaying the composite image 22 on the display 49 and using the keyboard and mouse 57 to manipulate the composite image 22 .
[0064] In step d), the second sheet is preferably made of a polyethylene foam having a thickness of at least 3 mm., but it may be as thick as ¼ inch or more, particularly for children's puzzles.
[0065] In step d), the pre-glued surface 59 is preferably provided with a glue of a type which remains flexible after setting thereof.
[0066] In step d), the glue is a pressure sensitive hot melt adhesive.
[0067] The step d) can include printing at least one additional copy 60 of the composite image 22 onto the first sheet, the at least one additional copy 60 being smaller than the first copy 22 .
[0068] In step b), the person or other subject 24 may be placed into a predetermined position in the second digital image 42 to match a situation or scene established by the first digital stored image 34 .
[0069] Step b) may involve capturing a third digital image of another person or other subject 24 , and step c) may then involve integrating this third digital image in with the first two digital images 34 and 42 within the composite image 22 .
[0070] The production of a custom jigsaw puzzle 30 for a user from a composite image 22 montage combining an image of a person or other subject with at least one stored image (from a variety of stored images offered to a user) may be carried out using the following more detailed sequence of steps:
[0071] a) selecting, from a variety of stored images offered to a user, at least one stored image in which the person or other subject is to be positioned;
[0072] b) taking a photographic image of the person or other subject in front of a blue screen with a defined pre-positioning of the person or other subject so that such subject person seems to interact with the stored image or forms an integral part of the stored image;
[0073] c) generating the image montage including the photographic image of the person or other subject positioned within the at least one stored image;
[0074] d) approving the generated image montage for use on the jigsaw puzzle;
[0075] e) transferring the image montage to the jigsaw puzzle production means;
[0076] f) triggering a start of the production of the jigsaw puzzle;
[0077] g) initiating movement of movable parts 54 of external housing of the jigsaw puzzle production unit during production of the jigsaw puzzle;
[0078] h) producing at least one larger hardcopy version of the image montage and at least one smaller hardcopy version of the same image montage;
[0079] i) applying the larger hardcopy version of the image montage to a pre-glued foam sheet;
[0080] j) transferring the larger hardcopy version of the image montage and pre-glued foam sheet to pressing means;
[0081] k) gluing the larger hardcopy version of the image montage to the pre-glued foam sheet;
[0082] l) die cutting the glued image montage and foam sheet received from the pressing means into jigsaw puzzle pieces;
[0083] m) affixing on generic packaging for each custom jigsaw puzzle one of the smaller hardcopy versions of the image montage on a predetermined location on the packaging, as well as a custom UPC code and any appropriate legal data;
[0084] n) inserting the fully die cut jigsaw puzzle pieces into the packaging;
[0085] o) closing the packaging; and
[0086] p) providing the custom jigsaw puzzle to the user through an opening in the jigsaw puzzle production unit.
[0087] Referring now to FIG. 8 , another aspect of the custom made packaging 70 is the need to provide a memory, such as the memory 45 of the computer 43 shown in FIG. 12 for storing data. Programming is needed that can select the correct legal data 72 from a first bank of data stored in the memory 45 , in relation to a specific product, and also select the proper UPC bar code 74 from those stored within a second bank of data stored in the memory 45 . This ties in with the means for selecting visual data 60 which determines which royalty information is applicable and which bar code corresponds to the selected background scene and foreground objects, and a reduced size version of the visual data is included on the label. Thus, a third bank of data stored in the memory 45 is needed. And of course means are required for applying the legal data 72 , the UPC bar code 74 and the visual data 60 onto a generic package to produce the custom made packaging 70 .
[0088] The means for selecting can be the computer 43 provided with a display 49 and with a keyboard and mouse 57 , as is shown in FIG. 13 .
[0089] The first bank of data is data chosen within the group including license data, copyright data, logo data and trademark data.
[0090] The third bank of data includes the composite images 22 including a person or other subject 24 .
[0091] The applying means may include the printer 53 which prints the legal data 72 , the UPC bar code 74 and the visual data 60 on stickers that can be applied on the generic packaging. As illustrated in FIG. 5 , these may be printed on a portion of the same first flexible sheet 48 on which the puzzle's composite image 22 is printed and cut off to form labels by the puzzle cutting die 80 , as is illustrated schematically in FIG. 13 .
[0092] In one embodiment of the invention, the apparatus for producing a custom made packaging can be used in conjunction with the jigsaw puzzle machine described above, in order to produce a custom made packaging wherein the visual data 60 on the packaging corresponds to the composite image 22 shown on the custom jigsaw puzzle. The legal data in this case will be any legal information (copyright, licenses, logo, trade-mark or others) related to licensed images used in the composite image 22 . The UPC code is related to the type of custom jigsaw puzzle produced and to the imagery used in the composite image 22 , to ensure proper tracking of inventory and sales of products.
[0093] Referring now to FIG. 12 a method for producing the custom made packaging is described in that figure and below, involving a number of basic steps to which may a plurality of optional steps may be added, as is explained below. According to the invention, there is provided a method for producing a custom made packaging, comprising steps of:
[0094] a) selecting 122 legal data within a first bank of data stored in a memory, in relation to a product;
[0095] b) selecting 124 a UPC bar code within a second bank of data stored in the memory, in relation to the product;
[0096] c) selecting 126 visual data 60 within a third bank of data stored in the memory, in relation to the product; and
[0097] d) applying 128 the legal data, the UPC bar code and the visual data 60 on a packaging to obtain the custom made packaging.
[0098] The steps a), b) and c) are performed by means of the computer 43 which is provided with a display 49 and with a keyboard and a mouse 57 .
[0099] In step a), the first bank of data can be data chosen within the group including license data, copyright data, logo data and trademark data.
[0100] In step c), the third bank of data is the composite image 22 including a person or other subject.
[0101] The step d) includes printing the legal data 72 , the UPC bar code 74 , and the visual data 60 on stickers to be applied on the generic packaging. Alternatively, this step can include printing the legal data 72 , the UPC bar code 74 and the visual data 60 on the generic packaging.
[0102] Although just a few embodiments of the invention have been described, it should be understood that the invention is not limited to these precise embodiments, and that various changes and modifications may be made without departing from the scope or spirit of the invention as set forth in the claims annexed to and forming a part of this specification. | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
This invention is related to commonly assigned and co-pending U.S. Ser. No. 10/094,128.
TECHNICAL FIELD
The present invention relates to a method and apparatus for clinching metal sheets together for assembling automotive vehicle structures.
BACKGROUND OF THE INVENTION
It is known that the manufacture of automotive vehicles often requires that metal sheets be attached to each other to form automotive vehicle structures. Clinching is one potential method of attaching such sheets. Clinching typically requires steps of stamping or otherwise cold forming corresponding indentations in at least two stacked metal sheets for frictionally or otherwise mechanically interlocking the sheets to each other. During conventional clinching processes, the metal sheets may require fairly substantial deformation of the sheets to form proper indentations. Such deformation can be particularly difficult to achieve in high strength metal sheets, which tend to be more brittle than certain lower strength metals, or require expensive heat treatment for relieving internal stresses. Therefore, there is a need for improved clinching techniques, apparatuses or both, for achieving high integrity attachment of metal sheets, particularly, sheets formed of advanced or high strength metals such as aluminum, magnesium, high strength steel and the like.
SUMMARY OF THE INVENTION
The present invention meets these needs by providing an improved method of clinching a first metal sheet to a second metal sheet, with particular utility in the formation of components for an automotive vehicle. The method involves clinching at least two sheets of metal with a punch and die assembly during or after contacting electrodes with the metal sheet for locally heating the metal sheet at the clinching locations. More specifically, the method includes a step of stacking a first metal sheet on a second metal sheet. Each of the sheets includes a first side and a second side and at least a portion of the second side of the first sheet is in overlapping contact with at least a portion of the first side of the second sheet for forming an overlapped region. Once the sheets are stacked, the first and second metal sheets are placed between a punch assembly and a die assembly. The punch assembly includes a punch surrounded by a first electrode, wherein the first electrode is adapted for contacting the first sheet. The die assembly includes a die surrounded by a second electrode, wherein the second electrode is adapted for contacting the second sheet. The first and second electrodes are each connected to an electrical energy source. Upon contacting the first and second electrodes with the metal sheets, the electrical energy source is capable of inducing an electrical current that flows between the first and second electrodes and the first and second metal sheets to elevate the temperature of the overlapped region of the first sheet and the second sheet. Mating indentations are punched within the overlapped region for additionally securing the first sheet to the second sheet. During formation of the indentations, an outer periphery of one of the indentations at least partially bonded to an inner periphery of another of the indentations. Additionally, the clinching die provides force to clinch the inner periphery onto the outer periphery.
The present invention also provides an apparatus for clinching a first metal sheet to a second metal sheet. The apparatus includes a punch assembly for stamping mating indentations in the first and second metal sheet while the first sheet is stacked upon the second sheet. The punch assembly includes a cylindrical punch moveable between at least a first position and a second position for forming the indentations. The punch assembly further includes a first electrode associated with the punch. A die assembly is also included in the apparatus for at least partially supporting the first and second sheets as the punch assembly stamps the indentations into the sheets. The die assembly includes a central cylindrical die defining a cup-shaped cavity for assisting in forming the indentations. The die assembly also includes an associated second electrode. The apparatus further includes an electrical energy source electrically connected to the first electrode and the second electrode for inducing a current between the first and second electrode and through the first and second sheets for elevating the temperature of portions of the first and second sheets prior to or during punching of the indentations into the portions.
The present invention thus provides an improved clinching apparatus and clinching technique for providing structurally improved indentations in stacked sheets thereby more securely fastening the sheets together. The ability to locally control the temperature of the sheets makes this invention particularly advantageous for the joining of high strength metals.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects and advantages of the present invention will become apparent upon reading the following detailed description in combination with the accompanying drawings, in which:
FIG. 1 is a sectional view of a clinching apparatus prior to clinching a pair of stacked metal sheets to each other;
FIG. 2 is a sectional view of the clinching apparatus of FIG. 1 during clinching of the pair of stacked metal sheets to each other;
FIG. 3 illustrates the clinching apparatus of FIGS. 1 and 2 with a robot arm and an energy source.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, a first metal sheet 10 is clinched to a second metal sheet 12 by a clinching apparatus 14 . The clinching apparatus 14 includes a punch assembly 16 for stamping generally cup-shaped or generally cylindrical mating indentations 18 , 20 into the metal sheets 10 , 12 and a die assembly 22 for supporting the metal sheets 10 , 12 and for assisting in the stamping or forming of the indentations 18 , 20 .
The punch assembly 16 includes a generally elongated metal stripper 24 having an opening 26 extending down a length of the stripper 24 . An elongated cylindrical steel punch 28 of the assembly 16 is received in the opening 26 and the punch 28 is moveable along a length of the opening 26 between at least a first position, as shown in FIG. 1, and a second position, as shown in FIG. 2 . The punch 28 may be moved hydraulically, mechanically, electrically, pneumatically or otherwise. Preferably, the punch assembly 16 also includes a spring 30 attached to the stripper 24 , the punch 28 or both that is biased against the motion of the punch 28 from its first to its second position for assisting in retracting the punch 28 after clinching as further described below.
A copper electrode 34 of the punch assembly 16 is generally annular and surrounds at least a portion of the stripper 24 and the hole 26 through which the punch 28 moves. A generally annular insulator 36 of the punch assembly 16 is disposed between the stripper 24 and the electrode 34 to electrically separate the electrode 34 from the stripper 24 and the punch 28 . The insulator 36 may be formed of an insulative material such as a plastic, polymer, ceramic, or the like. In one preferred embodiment, the insulator 36 is a laminate formed with a fabric or paper molded with a synthetic resin.
In FIGS. 1 and 2, the punch 28 , the hole 26 , the spring 30 , the insulator 36 and the electrode 34 are generally cylindrical, coaxial or both about an axis (not shown) extending centrally along their lengths. Preferably, a housing (not shown) can be used to fasten the electrode 34 , the insulator 36 , and the stripper 24 together. Alternatively, other conventional fasteners or fastening techniques may be used.
The die assembly 22 includes a generally cylindrical die 44 having a central cylindrical opening or cavity 46 . Preferably, the cylindrical die 44 includes three clinching blades 48 that are positioned in an annular arrangement to substantially surround a central cylindrical member 50 . Also preferable, an elastic band 52 surrounds the clinching blades 48 to maintain the blades 48 around the central member 50 . As seen, the blades 48 form a generally annular and cylindrical wall 54 for defining the cavity 46 . Alternatively, however, other dies may replace the die 44 shown. For example, the die 44 may be formed as a single part providing a cavity defined by a sloping annular wall for forming the cavity in a frusto-conical shape.
The die assembly 22 further includes a generally cup shaped electrode 60 with an annular portion 62 and a base portion 64 that cooperatively define a cavity for receiving the die 44 . Preferably, the die assembly 22 also includes a generally cup-shaped insulator 68 with an annular portion 70 and a base portion 74 defining a cavity wherein the insulator 68 is formed of a material similar to the material of the insulator 36 of the punch assembly 16 . As shown, the insulator 68 fits flush within the cavity of the electrode 60 and the die 44 is received in the cavity of the insulator 68 for electrically separating the die 44 from the electrode 60 . By changing the dimensions of the insulator 68 , the die 44 or both, a variety of different dies having a variety of different sized or shaped cavities may be interchanged within the cavity of the electrode 60 if desired. The components of the punch assembly 16 and the die assembly 22 may be fastened together as desired by conventional fasteners, adhesives, a housing and the like.
The punch assembly 16 , the die assembly 22 or both may be mounted to various apparatus for moving the punch assembly 16 or the die assembly 22 relative to each other, such as robots, C-frames and hard tooling such as a die set. In the exemplary embodiment shown in FIG. 3, the punch assembly 16 is attached to a robot arm 84 that can move the punch assembly 16 as needed or desired. The die assembly 22 is stably positioned adjacent the robot arm 84 .
An energy source 86 such as a transformer or other energy source is electrically coupled to the electrodes 34 , 60 of the punch assembly 16 and the die assembly 22 for providing electrical current to those electrodes 34 , 60 .
Referring to FIGS. 1 and 2, the first metal sheet 10 and second metal sheet 12 each include a first side 90 and a second side 92 . The first sheet 10 is stacked upon the second sheet 12 such that at least a portion of the second side 92 of the first sheet 10 is in substantially continuous contact with at least a portion of the first side 90 of the second sheet 12 at a location for forming the indentations 18 , 20 . The sheets 10 , 12 may be formed of several metals. Preferably, the sheets 10 , 12 are formed of a high strength or advanced metal such as aluminum, magnesium, high strength steel or the like with thicknesses ranging between 0.6 mm and 3.0 mm although thicker of thinner sheets may also be used.
The stacked sheets 10 , 12 are placed between the punch assembly 16 and the die assembly 22 of the clinching apparatus 14 . Preferably, the sheets 10 , 12 are placed upon the die assembly 22 such that the second side 92 of the second sheet 12 contacts the die assembly 22 . Thereafter, the punch assembly 16 is contacted with first side 90 of the first sheet 10 (e.g., using the robot arm 84 or another apparatus) to clamp the sheets 10 , 12 between the punch assembly 16 and the die assembly 22 .
When the sheets 10 , 12 are clamped between the assemblies 16 , 22 , the electrode 34 of the punch assembly 16 is in contact with the first side 90 of the first sheet 10 and the electrode 60 of the die assembly 22 is in contact with the second side 92 of the second sheet 12 . The energy source 86 induces an electric current that flows between the two electrodes 34 , 60 through each of the sheets 10 , 12 . Advantageously, the current may be applied for as short as about {fraction (1/30)} of a second using about 20 kiloamps of electricity for aluminum, however, different levels of energy may be used for different amounts of time depending on the application. The current provides energy to the sheets 10 , 12 thereby elevating the temperature of (i.e., resistive heating) at least a portion of each of the sheets 10 , 12 (i.e., the overlapped region) to a desired temperature. Preferably, the heated portions are the portions in which the indentations 18 , 20 are to be formed.
Thereafter, the punch 28 is moved from its first position to its second position as shown in FIG. 2 to form the indentations 18 , 20 in mating relation to each other (i.e., the indentation 18 in the first sheet 10 is securely fit within the indentation 20 in the second sheet 12 ) in the heated portions. As the indentations 18 , 20 are stamped into the sheets 10 , 12 , the wall 54 of the clinching die 44 provides force against the outer periphery of the indentation 20 in the second sheet 12 to clinch the inner periphery of the indentation 20 in the second sheet 12 about the outer periphery of the indentation 18 in the first sheet 10 thereby forming a joint. In the embodiment wherein a plurality of clinching blades 48 are surrounded by the elastic band 52 , the blades 48 may flex slightly outward to assist in forming and clinching the indentions 18 , 20 . After formation of the indentations 18 , 20 , the spring 30 retracts the punch 28 from the indentations 18 , 20 such that the sheets 10 , 12 may be removed from the die assembly 22 together.
Advantageously, clinching the sheets 10 , 12 after heating the portions of the sheets 10 , 12 to be clinched allows the indentations 18 , 20 to be more easily formed without causing the structural defects that can be caused by cold forming techniques. Additionally, the heated inner periphery of the indentation 20 in the second sheet 12 tends to bond or weld to the heated outer periphery of the indentation 18 in the first sheet 10 thereby further securing the first sheet 10 to the second sheet 12 .
Although, the assemblies shown use electrodes coupled to an electrical energy source, it is contemplated that other energy sources suitable for locally treating the indented sheets, such as lasers (e.g., carbon dioxide or N:Yag lasers) may be attached to or form part of the punch assembly 16 , the die assembly 22 or both. It is further contemplated that the electrodes 34 , 60 may not surround the punch 28 or die 44 , but may be otherwise associated with or adjacent the punch 28 or die 44 or that the electrodes 34 , 60 may be integrally formed as the punch 28 or die 44 .
The method and apparatus described above may be used for attaching several different automotive components that have sheet metal or sheet metal portions. Examples include peel joints, lap joints, various vehicle panels such as door panels, decklids, hoods, sunroof applications and the like. Furthermore, the overlapped regions of the sheets may be continuously bonded or intermittently bonded over some or all of its area.
Advantageously, clinching according to the present invention is inexpensive, can improve joint consistency, and can extend the life of tooling used to make the clinched joints.
It should be understood that the invention is not limited to the exact embodiment or construction which has been illustrated and described but that various changes may be made without departing from the spirit and the scope of the invention. | 4y
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RELATED APPLICATIONS
This application claims the priority of European Patent Application No. EP 10 172 632.1, filed Aug. 12, 2010, the entirety of which is hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
Field of the Invention
The invention relates to an actuator and to an exhaust gas recirculation valve, a wastegate or a variable turbine geometry device of a turbocharger comprising an actuator of this kind.
In the field of internal combustion engines, it is known to recirculate exhaust gas to the fresh air side as a function of the operating state in order to reduce fuel consumption and pollutant emissions. The associated valve may be provided in this connection with a tappet displaceable in translation or with a flap actuated by means of a lever, while it may be advantageous for the actuator to have a rotary drive. This applies in the same manner to wastegates and/or variable turbine geometry devices of exhaust gas turbochargers, adjustable by means of a tappet displaceable in translation.
Description of the Related Art
An exhaust gas recirculation valve is known from EP 1 111 227 A2, in which the rotary motion of a drive is converted into a translational motion of the valve element. A rotary motion is imparted to the valve element at least at the start of the opening operation.
EP 1 526 271 A1 relates to an exhaust gas recirculation valve in which the rotary motion of a drive is converted into a reciprocating motion of the valve element, wherein the valve element may rotate with the drive element during the opening operation, but is not forcibly rotated therewith. The rotary motion is converted into a reciprocating motion essentially by means of a driven “screw” comprising a thread in engagement with a fixed, but rotatable wheel.
SUMMARY OF THE INVENTION
An object of the invention is to provide an improved actuator, particularly with respect to its operating characteristics.
This problem is solved by the actuator described in claim 1 .
The latter comprises a drive, at least one rotatable threaded element and at least one output element driven in translation. The drive of the actuator is preferably designed as a rotary drive, but is not limited thereto. The rotatable threaded element may be, e.g. a screw comprising a thread or part of a thread or another threaded element. The screw could also be referred to as a “worm”. The output element driven in translation is in engagement with the screw in such a manner that rotation of the screw leads to a translational motion of the output element. The output element may be, e.g. a portion projecting from the valve tappet, a wheel or roller projecting therefrom and in engagement with the screw, or an element comprising a mating thread.
According to the invention, the threaded element has at least two regions of differing pitch. In other words, the thread may be finer or coarser in some regions than in others. A fine pitch allows a greater opening force to be transmitted, accompanied by greater rotational travel. A comparatively large force of this kind can be used, e.g. at the start of the opening movement of a valve to apply a particularly high force, e.g. in order to release bonded joints. As soon as these are released, the force can be reduced, as a result of which the thread can be coarser in this region. It should be mentioned by way of example that, e.g. a force of between 400 N and 250 N to 300 N can be generated over the first millimeters of a valve stroke, while this force moves between 200 N and 300 N in the remaining region of the valve stroke. The finer region may correspond, e.g. to rotation of 40° to 70°. The transition to a coarser region furthermore does not necessarily have to be in the form of a bend, but may be in the form of a gentle curve, e.g. extending over an angle of 90° to 100°. In other words, a region is provided in which the pitch increases continuously from that of a fine region to that of a coarser region or decreases in the opposite direction. The entire range of rotation of the threaded element may be, e.g. 300° to 500° or more.
A rotational axis of the threaded element is inclined relative to a translational axis of the output element. In geometric terms, the two axes are skewed relative to one another. This essentially means that forces are transmitted between the threaded element and the output element in a direction that is not inclined relative to the contact surface of the threaded element, or at least not to such a great extent as hitherto. If the rotational axis of the threaded element and the translational axis of the output element are parallel to one another, forces are conventionally transmitted from the screw to the output element via a surface inclined relative to the translational axis of the output element. This means that a rectilinear force applied by the output element, e.g. as a result of the gas pressure, may lead to rotation of the threaded element, thereby resulting in unintentional displacement of a valve element. In the actuator according to the invention, inclination of this kind between the translational axis of the output element and the rotational axis of the threaded element is reduced so that higher forces are required for the rotation of the threaded element. In practice, this can substantially prevent a valve from being displaced unintentionally by gas forces.
Preferred developments are described in the further claims.
As mentioned, the basic concept according to the invention can be used in a particularly advantageous manner if the thread has a finer pitch at the start than in other regions. The start of the thread may advantageously correspond to the start of an opening operation, so that a particularly high force can be generated here.
In particular, the threaded element preferably has a surface with which at least one portion of the output element, e.g. the aforementioned projection or the small wheel described, is in contact, and which surface is substantially perpendicular to the translational axis of the output element, at least at the start of the thread. By virtue of this arrangement, any force applied by the output element acts on the threaded element in a direction substantially perpendicular to the surface and consequently cannot cause any unintentional rotation thereof. This therefore advantageously ensures that there is no unintentional opening of an exhaust gas recirculation valve even in the event of corresponding exhaust gas back pressure, particularly when combined with the fact that the thread is comparatively fine at its start.
The actuator according to the invention is furthermore preferably combined with a valve element movable only in translation and not rotatable. Response delays and obstructions to the opening movement can thus be reduced in an advantageous manner.
It is furthermore preferred that a point at which a portion of the output element is in contact with the threaded element is aligned at least substantially with an axis of a valve element moved in translation. No transverse or lateral forces are thus applied to the output element and its guide in the arrangement consisting of the valve element moved in translation and the output element operatively connected thereto. This offers advantages from the point of view of continuous operation of the valve. It should be mentioned in connection with the measure described hereinbefore that it still displays its advantages even without the inclination of the rotational axis relative to the translational axis described hereinabove and that it should consequently be regarded as subject matter of the application irrespective of this. However, the orientation of a contact point on the threaded element relative to the translational axis of the valve element described can advantageously be combined with the feature described hereinabove and with all of the features specified hereinafter.
It is furthermore preferred that the valve element opens in a direction extending against the exhaust gas pressure. The exhaust gas back pressure can thus advantageously be used to assist with the closure of the valve and therefore to minimize the amount of leakage in the closed state.
Single-stage gearing is preferably provided between the drive and the threaded element. Single-reduction gearing of this kind improves the response characteristics of the valve, in particular as a result of reduced friction and lower mass inertia. Alternatively, the gearing may also be two-stage or multi-stage gearing, thereby allowing for the generation of higher forces.
The threaded element is preferably furthermore connected at least indirectly to a spring element, e.g. a spiral spring, which is only rotated. A spring element of this kind advantageously acts as a “failsafe” device ensuring that the valve closes even in the event of malfunction of or interruption to the electrical system.
It has furthermore proven to be advantageous for a valve housing in which the valve element is arranged to be designed in one piece, e.g. as a cast housing. The number of parts used can thus advantageously be reduced.
Finally, the valve housing is preferably provided with at least one cooling duct. The valve housing can thus be cooled, in particular in the vicinity of a valve tappet, as a result of which it is possible to improve the durability of the valve tappet and the tappet seal and guide and therefore of the exhaust gas recirculation valve as a whole.
In addition to an exhaust gas recirculation valve, the combination of at least one actuator according to the invention with a wastegate and/or a variable turbine geometry device of a turbocharger is also disclosed. Reference should be made in this connection with respect to the combination both with an exhaust gas recirculation valve and with the said components of a turbocharger to EP 2 172 682 A1, the disclosure of which with respect to details of the actuator, the exhaust gas recirculation valve and/or the threaded element referred to there as a threaded element is hereby incorporated by reference into the subject matter of this application. This publication is related to U.S. Publication No. 2010/0176325 (application Ser. No. 12/574,575), the entirety of which is also incorporated by reference herein and portions of which are included herein in connection with the description of FIGS. 3 and 4 . With respect to a wastegate and/or a variable turbine geometry device of a turbocharger, this applies in particular to the application entitled “ACTUATOR FOR A WASTEGATE OR A VARIABLE TURBINE GEOMETRY DEVICE AND METHOD OF ACTUATION” U.S. application Ser. No. 13/208,266) filed in the name of the Applicant on the same date as the present application, the entirety of which is hereby incorporated by reference herein. In other words, all of the details disclosed therein relating to a wastegate, a variable turbine geometry device and/or the actuator disclosed therein can be used in the actuator according to this application, even when used with a valve, in particular an exhaust gas recirculation valve.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in more detail by way of an embodiment illustrated by way of example in the accompanying drawings, in which:
FIG. 1 is a side view of the threaded element of an actuator according to the invention, and
FIG. 2 is a developed view of the thread of the threaded element shown in FIG. 1 .
FIG. 3 shows a side view of the exhaust gas recirculation valve according to the invention; and
FIG. 4 shows a partially cut-away view of the exhaust gas recirculation valve according to the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 is a side view showing the threaded element 18 of an actuator according to the invention rotatable about an axis 100 . In the case shown, the threaded element 18 has an almost complete (that is, almost 360 degree) thread 120 in which, e.g. a roller is situated in the mounted state, the roller being provided at the upper end of a valve tappet. If the valve tappet is guided axially and in this respect cannot rotate about the axis 100 , while the threaded element 18 rotates about the axis 100 , a rotary motion of the threaded element 18 is converted into a translational (reciprocating) motion of a tappet.
FIG. 2 shows how the pitch of the thread of the threaded element 18 differs in some regions. At the start (region 200 ), it is comparatively fine so that a particularly large force can be generated here, e.g. at the start of an opening movement. This is followed by a region 220 with a continuously increasing pitch, which leads to a region 240 which is in general coarser than the region 200 . Although this means that less force can be transmitted, the reciprocating motion takes place more rapidly in this region. It should be mentioned that the threaded element 18 may also have more or less than the almost complete thread shown in FIG. 1 . The dimensions of the regions 200 to 240 may furthermore vary from those shown in FIG. 2 .
As can be seen from FIG. 3 , the exhaust gas recirculation valve 10 according to the invention comprises a drive 12 in the form of an inclined motor. In the illustrated embodiment, a pinion 14 is arranged on the motor shaft and drives a gear 16 . The drive element 18 in the form of a worm gear (or worm) is attached to the gear 16 and drives the valve tappet 20 as described in more detail below. In the illustrated embodiment, as can be seen in more detail from FIG. 4 , the worm comprises an axis A that is supported both at its upper end and at its lower end. In the illustrated embodiment, the arrangement of gear 16 and worm 18 is connected to a coil spring 22 which is solely twisted upon opening and closing of the valve. In the illustrated embodiment, the combination of pinion 14 and gear 16 corresponds to a single-stage transmission having the above-described advantages.
The conversion of the rotary motion of the worm 18 into a translational motion of the valve tappet 20 is effected by means of the driven element 24 which, in the illustrated embodiment, is configured as a small wheel and is in engagement with the thread of the worm 18 . The small wheel 24 is rotatably attached to a bracket 26 fixed to the valve tappet 20 . The valve tappet 20 is supported in a suitable bushing 28 which, in the illustrated embodiment, is provided in a valve housing 30 configured as a one-piece cast part. Moreover, as can be seen from FIG. 4 , the valve housing 30 may be configured so as to additionally receive the drive 12 and the arrangement of drive element 18 and driven element 24 . Only the transmission in the form of the pinion 14 , the gear 16 and the coil spring 22 are located in the area of a lid 40 . This lid may further comprise a connector (socket) 42 for electric terminals. For example, a connection to a controller connected to an engine control unit may be performed by means of this socket in order to electronically control the operation of the valve. With the coolant parts 32 one may discern that the valve housing 30 may advantageously be cooled in order to cool the valve tappet 20 and its bearing and seal, too.
A valve head (plate) 34 engaging a valve seat 36 , which advantageously is provided with rather sharp edges is attached to the valve tappet 20 . Advantageously, the valve element in the form of the valve head 34 is always, that is both in the open and the closed state, situated within the valve housing 30 . In the illustrated embodiment, the opening of the valve head 36 is effected against the exhaust gas pressure, that is, it opens downward according to the orientation of FIG. 3 , so that the valve head 36 assists in closing the valve in response to exhaust gas pressure. At the same time, there is no danger that the exhaust gas pressure inadvertently displaces the valve, due to the following reasons.
As can be seen from FIG. 3 , the rotational axis A of the worm 18 serving as drive element is inclined with respect to the translational axis of the driven element 24 , in other words, with respect to the axis of the valve tappet 20 . Thus, in the illustrated embodiment, the surface in the region of the thread of the worm 18 engaging the small wheel 24 may be disposed largely perpendicular to the axis of the valve tappet 20 . Thus, if a force acts upon the valve tappet 20 , for example due to the exhaust gas pressure, this force will largely act perpendicular to the surface in the area of the thread of the worm 18 , and consequently cannot twist it. Thus, an inadvertent displacement of the valve may advantageously be avoided, a circumstance particularly relevant for small openings.
The preferred embodiment illustrated in the figures provides a further advantage, which will be explained by means of FIG. 4 . To begin with, in FIG. 4 the gear 16 and the coil spring 22 are shown in section for better understanding. From FIG. 4 one may further take that the worm 18 comprises a nearly complete turn of a thread. Further, from the illustration of FIG. 4 one may take the additional advantage that the location at which the small wheel 24 engages the thread of the worm 18 is largely aligned with the axis of the valve tappet 20 . In this way, no transverse or lateral forces are generated, offering advantages for the durability of the valve. As mentioned, this arrangement is achieved by means of the largely U-shaped bracket attached at the upper end of the valve tappet 20 and rotatably supporting the small wheel 24 at its other end.
As can additionally be taken from FIG. 3 , a stationary guide 38 may be provided, which comprises a protrusion (not discernable in FIG. 1 ) extending into a slit of the bracket 26 , for example, so that the bracket 26 , which translates together with the valve tappet 20 upon actuating the valve, is guided in the direction of motion. FIG. 3 also shows that the guide 38 may be arranged on a plate 44 to which the drive 12 may additionally be attached and/or in which the axis of the worm 18 may be supported. | 4y
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TECHNICAL FIELD
[0001] The present invention relates to the field of micromechanics. It more particularly relates to a method for manufacturing a micromechanical part. It is particularly applicable in the field of machining parts by deep etching, in particular fragile parts, made from silicon, glass or metal alloys. It also applies to other machining processes such as: laser machining, water jet machining, electro-erosion machining, LIGA machining, chemical machining of glass, etc.
[0002] The invention also relates to a part that may be obtained using this method.
BACKGROUND OF THE INVENTION
[0003] Currently, as shown in FIG. 0 , during machining of a part b from a substrate c of the wafer type, the part is made while preserving small bridges a of material that connect the part b to the substrate c. These bridges a form weak points that are next broken with a tool d that biases them in flexion or shearing. This method causes significant stresses in the part during breaking of the bridges. Furthermore, the energy required to break the bridges is substantial, and its sudden release at the time of the break sometimes causes damage on the fragile zones of the part, sometimes even at a significant distance from the bridge itself (transmission of the shock wave through the part or wafer). Yet some parts may sometimes include flexible pivots that are as weak as the bridges and that can be broken by the energy released during the breaking of the bridges.
[0004] To avoid these problems, the parts have sometimes been broken using laser cutting of the bridges. This approach is complex and expensive and leaves bridge stubs, the appearance of which is generally not well received.
[0005] Furthermore, the deformations undergone by the substrate or the part being manufactured or assembled also generate stresses on the part, which sometimes cause damage or breakage.
[0006] The present invention aims to resolve these problems simply, effectively and economically.
BRIEF DESCRIPTION OF THE INVENTION
[0007] More specifically, the invention relates to a method for manufacturing a micromechanical part from a substrate in which the part is manufactured by forming a plurality of fasteners between the part and the substrate, said fasteners being sacrificial. The fasteners comprise at least one hinge at the end of each fastener situated on the part side. The method comprises a step for breaking the sacrificial fasteners.
[0008] The invention also pertains to a part comprising a frame and a portion that is hinged relative to the frame, at least one guiding between the portion and the frame with at least one degree of freedom and at least one sacrificial connection between the hinged portion and the frame in the form of a released bolt capable of occupying two states, a singular state that makes it possible to block at least one degree of freedom of the articulated portion and a second state that makes it possible to set said portion in motion according to the degree of freedom of the guiding blocked in the singular state, until sacrificial connection is broken, the movement caused by the unlocking being tolerated by the guiding.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Other details of the invention will appear more clearly upon reading the following description, done in reference to the appended drawing, in which:
[0010] FIG. 0 , already mentioned, relates to the state of the art,
[0011] FIGS. 1 to 17 propose different illustrations of fastener types that can be used to connect a part to its wafer,
[0012] FIGS. 18 to 41 show example applications of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0013] One of the basic principles of the invention is to connect a part machined from a substrate using sacrificial fasteners which, particularly advantageously, comprise at least one hinge at one of their ends situated between the fastener and the part. It is advantageously possible to provide a second hinge at the end situated between the fastener and the substrate. By suitably combining the different types of connection that will be described below, it is possible to control the degrees of freedom of the part relative to the substrate, and thus to allow the movements of the part in certain directions, so as to limit the stresses experienced by the part, while maintaining it rigidly in other directions.
Neck Profiles
[0014] The hinges of the fasteners are made by thin areas formed in beams or blades that form the fasteners. Typically, the thin area is approximately 10 times weaker than the fastener. It has a sectional size approximately 10 times smaller than that of the fastener, and a longitudinal size smaller than 1/10 th the length of the fastener. If the thin area only pertains to one dimension of the section of the beam, the neck is said to be 2D ( FIG. 1 ), since it can be manufactured using a two-dimensional machining process. If the thin area pertains to both dimensions of the section of the beam, the neck is said to be 3D ( FIG. 1 b ), since it requires machining in three dimensions.
[0015] Different neck profiles can be used ( FIG. 16 ) to form the hinges. The most common are the prismatic neck (a), the circular neck (b) and the notched neck (c). Here we have shown 2D necks, but these illustrations may be transposed to 3D necks. The notched neck shown enlarged in FIG. 17 is particularly suitable for the present invention, since it makes it possible to concentrate the stresses in a very reduced material volume when the neck is biased in simple flexion. Thus, if one wishes to obtain a break, that break occurs with a reduced release of elastic energy. The stress concentration effect can be accentuated by reducing the radius r at the bottom of the notch to make it substantially smaller than the thickness h of the residual bridge.
Different Connection Types
[0016] Eleven different connection chains can be used in the context of this invention.
[0017] 1. The “simple connecting rod” ( FIG. 2 ) is made up of two flexible necks ( 1 ) and ( 3 ) and a rigid segment ( 2 ). In a planar analysis, its kinematic function is identical to a simple connecting rod hinged by two pivots ( FIG. 3 ).
[0018] 2. The “connecting rod with an intermediate hinge” ( FIG. 4 ) is identical to the simple connecting rod, but further includes a third flexible neck ( 3 ) situated approximately at the middle of the rigid segment. In a planar analysis, its kinematic function is identical to a simple knee joint ( FIG. 5 ).
[0019] 3. The “L shaped simple connecting rod” ( FIG. 6 ) is made up of three flexible necks ( 1 , 2 and 3 ) connecting two approximately perpendicular rigid segments. In a planar analysis, its kinematic function is identical to the chain ( FIG. 7 ).
[0020] 4. The “L shaped simple rod with an intermediate hinge” ( FIG. 8 ) is identical to the symbol L, but further includes an additional neck ( 2 ) forming a knee joint. In a planar analysis, its kinematic function is identical to a chain ( FIG. 9 ).
[0021] 5. It is also possible to use connections of the spatial rod type ( FIG. 2 b ), i.e., a rod equipped with a ball joint at each of the ends, which frees the part in all of its degrees of freedom, except traction-compression.
[0022] 6. The spatial connecting rod with intermediate hinge, like the spatial rod, includes a ball joint at each of its ends. It also includes an intermediate hinge, which may be a spatial intermediate hinge ( FIG. 4 b ), defined by a 3D neck, i.e., movable in all three dimensions, or a planar intermediate hinge (not shown), defined by a 2D neck, i.e., movable in two dimensions.
[0000] a. FIGS. 10 a and 10 b illustrate two alternatives of spatial connecting rod with intermediate hinge. In FIG. 10 a , the ball joints are defined by the combination of two crossed 2D necks, i.e., oriented orthogonally. Between the two ball joints, a 2D neck forms the intermediate hinge. In FIG. 10 b , there is an equivalent spatial rod, in which the ball joints are made by 3D necks and the intermediate hinge is shown with a different orientation. In both cases, a spatial rod is obtained only restricting one degree of freedom, i.e., the traction-compression direction.
[0023] It will be noted that the necks may be adapted by creating, as shown by FIG. 12 , fragile zones making it possible to concentrate the stresses precisely and, if applicable, to obtain breaks of those necks, in clearly determined locations, as will be understood below. These fragile zones may be obtained by arranging one or more aligned openings in the flexion zones.
[0024] 7. As the seventh type of connecting chain, FIG. 14 proposes a torsion bar including a torsion hinge combining at least two torsion-flexible structures. It is possible to obtain this type of structure using zones having a particular torsion profile, as illustrated in FIG. 15 (references 1 - 4 ), while having sections with thin walls that are not closed, therefore partially flexible in torsion. It is thus possible to have T-, Z-, L-, cross-shaped profiles that make it possible to obtain hinges blocking 5 degrees of freedom (only torsion is free). A V-shaped profile also works in this way.
[0025] It is also possible to have torsion bars using simple connecting rods (references 5 , 6 ), horizontal or vertical, which block 3 degrees of freedom. Two of these rods may be placed in series so as, based on their respective arrangements, to obtain hinges blocking 3, 4 or 5 degrees of freedom. Thus, it is for example possible to implement two simple connecting rods arranged perpendicular to one another, so as to form an L, T or V.
[0026] This type of fastener is particularly suitable for applications in which little surface area of the substrate is available, for which a break of the fastener by torsion is ideal. It is also possible to position two links in series, the axes of which coincide. This makes it possible to obtain a hinge blocking 3 degrees of freedom. By combining these two alternatives, a hinge blocking 4 degrees of freedom is obtained.
[0027] The part may be provided with an actuating portion, off-centered relative to the axis of the hinge and making it possible to bias it more easily in torsion. This portion may be a beam, provided with a hole with which a tool can cooperate.
[0028] 8 and 9. It is also possible to connect the part to the substrate directly using a 2D neck ( FIGS. 11 a and 11 b ) or a 3D neck ( FIG. 11 c ), as defined above.
[0029] 10. It is possible to produce a 2D blade with 3 necks as proposed in FIG. 13 b , which makes it possible to block or release out-of-plane degrees of freedom. In this example, we have three 2D necks, which makes it possible to obtain a hinge blocking three degrees of freedom, like a simple blade.
[0030] 11. It is also possible to produce a 3D blade with 3 necks as proposed in FIG. 13 a . In this example, there are two 2D necks and one 3D neck, positioned between the two 2D necks. A fastener is thus obtained blocking two degrees of freedom, like a simple blade provided with a notch in the middle thereof.
[0031] The fasteners of type 10 and 11 may include means for pushing the central hinged zone along the axis Z, until it breaks, in particular for applications described later. Fragile zones as proposed in FIG. 12 can also be added in the central neck of the fastener.
[0032] Thus, by having fasteners chosen from among the different possible connections proposed above, one skilled in the art can release or restrain a given degree of freedom, based on the mobility that one wishes to impart to the part in reference to its substrate, during its manufacture and relative to its application. The part may be blocked rigidly on the substrate, or it is for example possible to release flexion in either direction.
Simplified Illustration
[0033] For simplification reasons, FIGS. 20 to 37 use a conventional illustration. As an example, the structure of FIG. 18 is shown in a simplified manner in FIG. 19 : the substrate is symbolized by Earth connections (crosshatching a, b and c) at the base of the necks.
Principle of the Basic Connection
[0034] As will be described below, a first aspect of the invention lies in the use of the connections described above to connect a part to the substrate in which it has been machined. The connections formed between the part and its substrate must be broken so as to release the part to allow it to be used. Thus, the connections are used in a sacrificial manner. Advantageously, the connections are used in order to control the energy produced during the release of the part and avoid, or at least limit, the risks of breaking of the part.
[0035] FIG. 20 shows a typical example of a connection by a rod between a part (d) and a wafer (e) in which the part has been machined. The part (d) is rigidly fastened to its wafer (e) by two simple connecting rods (b) and (c) and a connecting rod with an intermediate hinge (a). In this arrangement, with only these, the two simple connecting rods give the part a single degree of freedom that corresponds to translation along the axis x (for movements of infinitesimal amplitude). The connecting rod with an intermediate hinge blocks that single degree of freedom, which limits the possibility of any relative movement of the part with respect to the wafer.
[0036] To release the part ( FIG. 20 ), a tool (e) is used to bend the intermediate hinge according to its natural degree of freedom until the three necks ( 1 , 2 and 3 ) break. During bending of the intermediate hinge, a second order movement (shortening of the link) causes a translational movement of the part along the axis x (d). This degree of freedom being natural for the simple connecting rods (b) and (c), it does not cause forces or significant stresses in the part itself. This kinematic phenomenon is also illustrated in FIG. 21 .
[0037] Once the connecting rod with an intermediate hinge has been removed, a tool (f) ( FIG. 20 ) is used to bend one of the two simple connecting rods according to its natural movement until its next break (it is also possible to act directly on the part with the tool and to move it according to its natural degree of freedom). Lastly, the necks of the last link can be broken (if they were not broken at the same time as those of the second). The break caused by the movement according to the natural degree of freedom occurs without excessive dissipation of energy in the part.
Kinematic Conditions for Proper Operation
[0038] For the connection principle to work ( FIG. 22 ), it suffices for the axis (a) of the connecting rod with an intermediate hinge not to pass through the cooperation point (A) of the two axes of the other two rods. FIGS. 23 and 24 show two typical examples.
[0039] As an example, FIGS. 25 and 26 propose two arrangements that do not respect this condition and lead to two problems.
The connection of the part to the wafer is not rigid, because for small amplitude movements, one degree of freedom remains: this involves pivoting of the part around the cooperation point (A) between the three axes of the three links. During the release operation, the bending of the connecting rod with an intermediate hinge produces a second order movement (shortening of the link) that is blocked by the other two rods. This causes significant forces to pass through the part itself (and by reaction, through the wafer). Thus, breaking risks of the part or wafer occur.
[0042] The arrangements that produce the greatest rigidity in the plane, two advantageous examples of which are proposed in FIGS. 27 and 28 , are those where the axis (a) of the connecting rod with an intermediate hinge is perpendicular to the line (f) connecting the cooperation point (A) of the axes of the two simple connecting rods to the first neck (e) of the connecting rod with an intermediate hinge.
[0043] In the cases where the two simple connecting rods are parallel, the arrangements that produce the greatest rigidity in the plane are those where the connecting rod with an intermediate hinge is perpendicular to the other two rods. FIGS. 19 and 29 show two examples of this.
Kinematic Analysis
[0044] In a planar kinematic analysis, the connection principle is based on the structure of FIG. 30 . This kinematic structure includes 6 pivots and 2 closed kinematic loops. According to the Grübler method for calculating mobility, this corresponds to a connection with zero mobility 6−2×3=0. This corresponds to a blocked, isostatic connection. Thus, this connection has the interesting property that small dimensional variations of the part, links or wafer (under the effect of heat expansion or internal or external stresses, for example) do not cause strong forces or stresses in the part, reducing the risks of untimely break.
[0045] The insertion of a neck designed to form a unlocking mechanism on one of the links ( FIG. 31 ) adds mobility to the structure: 7−2×3=1. “Unlocking mechanism” refers to a fastener that could occupy a singular state in which one degree of freedom is blocked, which results in locking of the part, and a second state in which that degree of freedom is unblocked, which makes it possible to restore movement to the part, i.e., to unlock it. An excitation in this degree of freedom will allow various fasteners to break. Thus, in its generic configuration, this kinematic arrangement does not constitute a blocked connection between the part and the wafer. Nevertheless, the particular configuration used in the context of the present invention is a singular configuration of this kinematic structure where the 3 necks of the rod with intermediate hinge are aligned. In such a configuration, a rod with intermediate hinge is equivalent to a simple connecting rod. Thus, this singularity of the kinematics causes the degree of mobility of the rod with intermediate hinge to disappear, and the connection between the part and the wafer behaves in the same way as the arrangement of FIG. 30 : the part is rigidly fastened to the substrate.
[0046] In its physical implementation (for example, a monolithic cutout in a wafer), the stability of the rod with intermediate hinge around its alignment singularity is guaranteed by the elastic return torques of the three necks making it up. In fact, these three necks are machined in their neutral state (i.e., without elastic bias), in the aligned positioning. The minimum elastic energy therefore corresponds to the alignment configuration. Thus, below a certain critical compression load of the knee joint, the latter remains axially rigid. If a compression load exceeding that critical load occurs, then the elastic equilibrium of the knee joint initially aligned breaks and the structure buckles. It is preferable to avoid buckling of the rod with intermediate hinge throughout the entire manufacturing process. If it is provided that strong forces bias the part during certain production steps (for example, during polishing phases), then the rigidity of the necks of the rod with intermediate hinge must be chosen to be high enough to guarantee that the critical buckling load is greater than the maximum compression loads expected on the knee joint.
Supernumerary Fasteners
[0047] In the case of parts that are strongly mechanically biased in the out-of-plane direction during machining (for example, during polishing, drilling or milling steps), it may prove necessary to use more than three connecting chains to fasten the part to the wafer. The present invention proposes the use of “L shaped simple connecting rod” connecting chains. The latter provide a connection that is only rigid in the out-of-plane direction and therefore does not interfere with the planar kinematic functions of the 3 base links. These chains, called supernumerary (i.e., not essential to the definition of the position of the part relative to the substrate and imparting the hyperstatic nature), increase the rigidity and mechanical strength in the out-of-plane direction. FIG. 32 for example shows how 3 “L shaped simple connecting rods” can be used in addition to the 3 base rods (see FIG. 24 ). To release such a fastening system, it is necessary to start by breaking the unlocking mechanism (a), then the rods (b and c). Lastly, the part itself is moved into the plane until the “L shaped simple connecting rods” next break. FIG. 33 shows how the “L shaped simple connecting rods” deform when the part (a) is moved, for example along the axis x (any other direction of movement in the plane is also valid).
[0048] The “L shaped simple connecting rods” can be replaced by “L shaped simple rods with an intermediate hinge” ( FIG. 34 ). As in the case of connecting rods with an intermediate hinge, the alignment singularity allows them to play the same kinematic role as the “L shaped simple connecting rods”. These “L shaped simple rods with an intermediate hinge” further have the advantage ( FIG. 35 ) that they can be broken individually (manually or in an automated manner) without requiring movement of the part (a) itself. Thus, the strict sequence described, required when “L shaped simple connecting rods” are used (see paragraph above), no longer needs to be respected. It is possible to release the Ls or the rods first, indifferently. This reduces the risks of handling errors.
Embedded Necks
[0049] Irrespective of the type of connecting chain used, there is always a neck that is fastened to the part itself. After release, half of that neck remains on the part. The presence of that small protuberance may, in some cases, hinder the proper operation of the part. One solution to partially offset this drawback consists of embedding that neck, i.e., placing it withdrawn from the surface of the part ( FIG. 36 ). Thus, after release, there is no protuberance protruding from the surface.
[0050] Use of Connecting Rods with an Intermediate Hinge to Block Flexible Guides
[0051] Sometimes, the machined part includes, monolithically, a portion designed to be hinged on a frame using a guide, for example a flexible guide, and the frame. The fasteners as proposed in the present invention, in particular the connecting rods with an intermediate hinge, can also be used to block the movement of the hinged portion relative to the frame, typically for manufacturing or assembly. Thus, there is at least one sacrificial connection between the hinged portion and the frame in the form of an unlocking mechanism capable of occupying two states: a singular state that makes it possible to block at least one degree of freedom of the guide, and a second state that makes it possible to set said portion in motion according to one degree of freedom of the guide blocked in the singular state, until the sacrificial connection breaks, the movement induced by the unlocking corresponding to one of the degrees of freedom of the guide. The latter thus tolerates that movement, without significant forces or stresses appearing in the part, i.e., capable of damaging it.
[0052] FIG. 37 shows the typical example of a table with 4 flexible necks. This type of part must be immobilized during machining phases to avoid any untimely movement of the moving platform (b). This can advantageously be done using a connecting rod with an intermediate hinge (c) connecting the platform to the base (a). This base (a) will in turn be fastened to the wafer using three links (not shown in this figure). FIG. 38 shows the typical example of a pivot with a remote compliance center (RCC), the rotation of which is blocked by a connecting rod with an intermediate hinge.
EXAMPLES
[0053] FIG. 39 shows the plane of an RCC pivot to scale (which does not make it possible to clearly distinguish the necks), the rotation of which is blocked by a connecting rod with an intermediate hinge T 1 and the base of which is fastened to the wafer by two simple connecting rods T 2 and one second connecting rod with an intermediate hinge T 3 . These parts have been sized to be machined in a monocrystalline silicon wafer (typically 350 microns thick) by deep etching (DRIE). The first connecting rod with an intermediate hinge T 1 makes it possible to keep the lever pivoted by the RCC pivot during the assembly of the part. Once the part is assembled in its mechanism, the connecting rod with an intermediate hinge T 1 can be broken according to its natural degree of freedom to release the RCC pivot.
[0054] FIG. 40 shows a disc that must go through polishing steps during its manufacturing process. This disc is attached to the wafer (500 microns thick) by two simple connecting rods T 2 , one connecting rod with an intermediate hinge T 3 and nine “L shaped simple rods with an intermediate hinge” TL. All of the necks are embedded withdrawn from the surface, at the periphery of the disc. The release of the disc first goes through the break of the nine L shaped simple rods with an intermediate hinge, according to the natural degree of freedom to reduce the stresses undergone by the part. Then, the case of FIG. 24 occurs, the connecting rod with an intermediate hinge is released, and lastly the two simple connecting rods T 2 are released.
[0055] Lastly, whether for the connection of a part to its substrate or the maintenance of a portion that is hinged relative to its frame, a sacrificial fastener hinged at least at its end situated on the side of the micromechanical part is used to immobilize a micromechanical part temporarily. The sacrificial fastener is arranged so as to immobilize the micromechanical part, and it can be broken by actuation around the hinge.
[0056] The hinged sacrificial fastener can be an unlocking mechanism capable of occupying two states: a singular state that corresponds to a limited kinematic state of the part, and a second state in which the part has at least one additional degree of freedom relative to the singular state, the movement of the part according to that additional degree of freedom being able to cause a break of the hinged sacrificial fastener. In the event the part is made up of a frame and a portion hinged on the frame, the sacrificial fastener can also be a 2D neck or a 3D neck located precisely on one of the axes of rotation of the hinged portion. The movement of the part according to that degree of freedom can cause the sacrificial fastener to break. For example, in FIG. 41 , there is a hinged portion 6 that is hinged relative to a frame 2 by two links 5 . The frame is connected to the substrate 1 by two sacrificial links 4 and by one sacrificial connecting rod with an intermediate hinge 3 . The hinged portion 6 is also connected to the substrate by a sacrificial 2D neck 7 in order to immobilize the hinged portion during its assembly. The 2D neck can be broken by imparting a rotational movement around the axis of the neck, following arrow 8 .
[0057] The present invention is particularly advantageously applicable to produce micromechanical parts by deep etching, with a base of silicon from a wafer, but it can also be implemented for parts made with a base of glass or metal alloys, from a substrate. Depending on the considered material, it is possible to machine the part by laser machining, water jet machining, electro-erosion machining, LIGA machining, chemical machining of glass, etc. Relative to simple fasteners, formed from simple beams, the hinged fasteners according to the invention make it possible to functionalize the connection between the part and its substrate to give it a rigidity or freedom in the desired degrees of freedom based on a given application, and further making it possible to control the release of energy in the substrate and the part during breaking of the fasteners. A considerable decrease has been observed in the number of parts damaged or broken during manufacturing or during release from their substrate.
[0058] It will also be noted that the various examples proposed above may be oriented indifferently relative to the substrate, including by rotation of the fasteners around themselves, around their axes, in reference to the substrate. | 4y
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This application is a continuation of application Ser. No. 08/221,311, filed Apr. 1, 1994, now abandoned.
The present invention relates to a test kit for use in the rapid diagnosis of gastric disease by the detection of Helicobacter pylori bacteria in a gastric biopsy specimen. The test kit includes means for handling a biopsy specimen and a test composition containing urea and a combination of dye indicators as described in my U.S. Pat. No. 5,439,801 granted Aug. 8, 1995; the entire disclosure of said application being incorporated herein by reference.
It has become well-established that (1) the bacteria Helicobacter pylori causes chronic active gastritis (see the annexed Bibliography for the numbered references), and that (2) virtually all patients suffering from duodenal ulcer and perhaps 80% of patients having gastric ulcers are infected by H. pylori. There is also epidemiological evidence that (3) correlates the presence of H. pylori with gastric cancer. In view of these facts, a test for the presence of H. pylori in a gastric biopsy specimen has become the preferred method for the diagnosis of gastric disease.
The purpose of the present invention is to provide an improved test kit for the rapid, convenient, reliable and accurate detection of H. pylori in gastric biopsy tissue.
BACKGROUND AND PRIOR ART
An extensive description of the background and prior art for the diagnosis of gastric disease by the detection of H. pylori in gastric tissue is set forth in my U.S. Pat. No. 5,439,801 granted Aug. 8, 1995 and is incorporated herein above by reference.
Briefly, it having been seen that the bacteria H. pylori is present in endoscopically obtained gastric biopsy specimens from both gastric and duodenal ulcer patients and it being known that the enzyme urease is always associated with that bacteria, the concept of diagnosing the presence of such ulcers by testing biopsy specimens for urease suggested itself. Chemical tests for urease were already known in the art. In one such test a urea-containing broth provides a positive urease reaction (hydrolysis of urea) as below: ##STR1## as indicated by a change in color of the indicator Bacto phenol red from yellow (pH 6.8) to red to cerise at pH 8.1 or more alkaline due to the production of ammonia and/or ammonium carbonate by the urea-urease reaction. See the Difco Manual, 9th edition, Difco Laboratories, Detroit, Mich., (1953). The urea broth described in the Difco Manual was apparently used by B. J. Marshall in the work described in the Rapid Diagnosis of Campylobacteria associated with Gastritis, The Lancet, Jun. 22, 1985.
This type of urease test has come into commercial clinical use. In the United States a commercial test product is marketed under the trademark "CLOtest®". This product is described in U.S. Pat. No. 4,748,113 issued to Barry J. Marshall on May 31, 1988. The test of the Marshall patent commercially employs urea, a buffer, a bactericide, and phenol red as the dye indicator. This test is carried out in an alkaline pH range showing a positive result on a change of the indicator from yellow to red at a pH in the range from about 6.8 to 9.
In the Marshall test, a gastric mucosal biopsy specimen containing H. pylori is placed in solution or an aqueous agar gel containing urea, and indictor, phenol red, and buffers. The urease in H. pylori converts to urea to ammonia which raises the pH and turns the agar color from a yellow to red, indicating a positive test. According to the package insert in the Marshall commercial phenol red test (CLOtest®)it is recommended that the test be incubated at 30°-40° C. for three hours and it is indicated that it may take up to 24 hours to develop a positive test. This test relies on the passive diffusion of urease from the cell wall of the bacterium into the agar gel testing solution. Moreover, operating as it does at a pH above 6.5, the test may give a positive result with bacteria other than H. pylori and thus is not entirely specific for Helicobacter pylori. Specifically, Proteus, Pseudomonas, and E. Coli. species may cause a color change at this level and give a false positive test.
Another test kit for H. pylori is available commercially from Serim Research Corporation, 1000 Randolph St., Bldg. 17, c/o Miles Inc., Elkhart, Ind. 56515 under the trademark "PyloriTek". This kit includes test strips having a substrate pad containing 3.3% urea and, in a separate matrix, a reaction pad containing 0.1% bromophenol blue dye indicator and 0.2% sulfamic acid. The test kit also contains, in a separate container, a hydration solution consisting of 1.8% Tris buffer. This kit makes use of the same urease-urea reaction as the Marshall test to produce gaseous ammonia which changes the bromophenol blue from its original yellow color to make a blue test spot over a biopsy specimen on a yellow field to indicate a positive test. This test is said to be readable in 120 minutes and should not be read after that time to avoid false positives. While the two-hour usual test time is an improvement, it is apparent that an even more rapid and less complicated test would be desirable.
SUMMARY OF THE INVENTION
The present invention resides in the provision of a compact test kit for detecting H. pylori in a gastric biopsy specimen which comprises a closed well or reaction vessel containing a gelled test composition, means for exposing the well, and means for introducing the biopsy specimen to the gelled test composition in the well. The kit may also be provided with means to record pertinent data as to the patient's identity and the time and date of the test. The kit may also include means to seal the well after use. The kit may also be provided with a color spectrum for determining the results of the test by comparison with the color change of a combination of dye indicators in the test composition. The test composition is disclosed in detail in my U.S. Pat. No. 5,439,801 issued Aug. 8, 1995 referred to above.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described in greater detail in conjunction with the accompanying drawings, in which:
FIG. 1 is a top plan view of a preferred test kit;
FIG. 2 is a bottom plan view of the test kit of FIG. 1;
FIG. 3 is another bottom plan view of the test kit of FIGS. 1 and 2, showing a peelable label partially stripped away to uncover a gel-containing well in the test kit, and also showing the operation of means for removal of a biopsy pick from the test kit;
FIGS. 4 and 5 are detail drawings on an enlarged scale showing the means for removal of the biopsy pick from the test kit of FIGS. 1, 2 and 3;
FIG. 6 is a bottom plan view of the test kit of FIGS. 1-5 showing the use of the biopsy pick in placing a biopsy specimen in the gel in the test well;
FIG. 7 shows the use of the forked end of the biopsy pick in manipulating the biopsy specimen in the test well; and
FIG. 8 shows the peelable label resealing the well in the test kit after insertion of the biopsy specimen.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the accompanying drawings, a preferred test kit of the invention 10 has a body member 12 including an upwardly open tray divided into two compartments 14 and 16 by a longitudinally extending upright partition wall 18. Two outer edges of the larger open compartment 14 are closed by upstanding walls 20 and 22. Upstanding partition 18 closes a third inner side of compartment 14, the fourth side of compartment 14 being open at 24. The larger compartment 14 of the tray in the test kit contains a well 26 integral with the base 30 of the compartment 14. The well 26 is open at 28 through base 30 of compartment 14 but is closed on its four sides and the bottom 32 which is upward in FIG. 1 and downward in FIG. 2. The well 26 is preferably transparent although it is only necessary that it be open at 28 to make its contents visible.
The well 26 is filled with a test composition 32 containing urea and a dye indictor which changes color when a gastric biopsy specimen containing Helicobacter pylori is placed in the well. The well 26 containing the test composition 32 is closed at its open side 28 by a peelable sealing means 34 which extends over an indentation 62 in the open end 24 of compartment 14. The peelable sealing means 34 is peelably adhered to the back of lower surface 30 of the compartment 14.
A means for handling a biopsy specimen is removably mounted in the second longitudinal compartment 16 which is upwardly and downwardly open as shown in FIGS. 1, 2 and 3. The means for handling the biopsy specimen is preferably a pick 36 having an elongated shaft 38 having a tapered bifurcated point 40 at one end and a forked 42 device at the other end including a sharp point 44 and a blunt prong or spatula 46.
The means for handling a biopsy specimen such as the pick 36 is removably mounted in the compartment 16 by any suitable means such as by an adhesive or by a frangible integral molded joint. In the preferred embodiment shown in FIGS. 1, 2 and 3, the pick 36 is integrally but frangibly molded with a boss 48 which is firmly molded with or mounted on the wall 18 and extending into the compartment 16. The longitudinal compartment 16 containing the pick 36 has a deformable outer wall 50 which may optionally have a boss 52 extending into compartment 16 adjacent to or in contact with the pick 36. The pick 36 preferably has an enlargement 54 at the center of its shaft 38 intermediate the boss 48 and boss 52. The pick 36 is broken away from its frangible connection with boss 48 by deformation of the wall 50, by thumb pressure of the user or otherwise, to press the wall 50 inwardly to force the boss 52 into contact with the enlarged portion 54 of the pick to break it away from its frangible mounting on the boss 48.
An especially preferred embodiment of the means for mounting and demounting the pick is shown in FIGS. 4 and 5 in which the preferred configuration of the boss 48 extends outwardly from the inner wall 18 of the compartment 16 and has an upper planar side 56 and a lower slanting side 58 and a generally triangular cross section. The central enlarged portion 54 of the pick is frangibly connected to the under side of the lower slanting edge 58 of the flange 48. As the wall 50 is deformed inwardly by thumb pressure as shown in FIG. 3, the enlarged portion 54 of the pick is forced against the slanted surface 58 of the boss 48 until the connection is broken between the pick and flange and the pick is freed from its mounting.
Having freed the pick 36, it may be used as shown in FIGS. 7 and 6 to pick up the biopsy specimen by the point 44 as in FIG. 7 and to force it into the test composition 32 in the well 26 with the bifurcated point 40 as seen in FIG. 6. As shown in FIG. 7, the spatula 46 of forked end 42 of the pick 36 may alternatively be used to place the biopsy specimen in the test composition, as seen in phantom. In other words, the specimen is placed in the well 26 with either spatula 46 or point 44 of the pick 36, and then submerged in composition 32 with bifurcated point 40. Point 40 does not pierce the specimen so there is no tendency to pull the specimen out of the composition upon withdrawal of the pick.
FIG. 8 shows the use of the peelable sealing means 34 to re-seal the well 26 after insertion of the biopsy specimen. This peelable sealing means may also serve as a label to record the identity of the patient, the time and date of the test as shown in FIG. 8.
As shown in FIG. 1, the other side of the peelable sealing means 34 preferably carries a spectrum of colors and designations of the pH and negative (e.g. light green), slightly positive (e.g. medium green), moderately positive (e.g. dark green), and markedly positive responses (e.g. very dark green or blue), to this test. Other information and instructions may also be shown on this peelable label which can be read through the preferably transparent surface of the bottom wall 30 of compartment 14.
Other embodiments of the invention will be apparent from the preferred embodiments described above. | 4y
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BACKGROUND OF THE INVENTION
This invention relates to a device for shutting of the flow of fluid, such as gaseous fuel, in case of emergency such as an earthquake or accidental leakage of explosive gas.
In the case of an earthquake or accidental leakage of explosive gaseous fuel, it is required to shut off the flow of the gaseous fuel from a supply pipe or tank without fail to avoid secondary accidents caused by explosion of the gaseous fuel. It is desired that fluid shut-off device provided for such purpose not consume any electric power in the normal inoperative position and, once operated, maintain the operative shut-off position in spite of interruption of the electric current. A more important requirement is that such a fluid shut-off device have a very high reliability. To this end, it is desired that the device becomes operative by a very small amount of electric current and almost instantaneously after supply of the current. Also, the force for shutting off the flow of the fluid has to be sufficiently high.
The fluid shut-off devices hitherto provided could not satisfy the above requirements simultaneously. Also, the conventional devices of this kind have been relatively complex and expensive.
Accordingly, an object of the present invention is to provide a fluid shut-off device which is operable with high reliability by a small amount of electric current immediately after supply thereof.
Another object of the present invention is to provide a fluid shut-off device which can provide sufficient power to interrupt the flow of the fluid material when operated and which maintains the operated position until manually reset to an inoperative position.
A further object of the present invention is to provide a fluid shut-off device which is operated in connection with a detector of gas leakage or an earthquake.
Still another object of the present invention is to provide a fluid shut-off device which, once operated, holds the operated position without any supply of electric current.
Another object of the present invention is to provide a fluid shut-off device which is simple in structure and relatively inexpensive.
SUMMARY OF THE INVENTION
A fluid shut-off device of the present invention comprises a casing made of non-magnetic material and having a passage therethrough which is adapted to be connected to a fluid supply line, a metallic valve body movably disposed in a valve chamber formed inside the casing, and a slide member provided outside the casing. One of the valve body and the slide member is formed of permanent magnet material to magnetically attract with the other the slide member and the valve body. The slide member is urged to an operative position where the valve body closes the passage. The slide member normally takes another inoperative position against an elastic force of urging means by locking means. The locking means is released by deformation of a bimetallic strap when an electric current is supplied thereto.
Preferably, the locking means comprises a leaf spring supported in a cantilever manner and having an elasticity tending to flex inwardly. The leaf spring crosses over the bimetallic strap, which has a bridge-shape to hold the metal strap in a locking position in the inoperative position, but which is deformed by application of the electric current to displace the metal strap to an unlocking position.
Other objects and features of the present invention will become apparent from the following detailed description of preferred embodiments thereof when taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(a)-1(d) show a fluid shut-off device of the present invention in an inoperative position, in which FIG. 1(a) is a top plan view, FIG. 1(b) is a side view, FIG. 1(c) is a longitudinal sectional view, and FIG. 1(d) is a cross sectional view taken along line A--A in FIG. 1(a),
FIGS. 2(a)-2(d) show the fluid shut-off device of the present invention in an operated position, in which FIG. 2(a) is a top plan view, FIG. 2(b) is a side view, FIG. 2(c) is a longitudinal sectional view, and FIG. 2(d) is a cross sectional view taken along line B--B in FIG. 2(a),
FIG. 3 is a diagram showing an electric circuit for operating the fluid shut-off device by an electric signal from a detector for gas leakage,
FIG. 4 is a perspective view showing the operation of the fluid shut-off device, and
FIG. 5 is a longitudinal sectional view showing the fluid shut-off device made to be operable by detecting an earthquake.
DETAILED DESCRIPTION OF THE INVENTION
Referring to a fluid shut-off device of the present invention with reference to FIGS. 1(a)-1(d) showing the device in an inoperative position, an elongated casing 1 is formed by threadedly engaging two sections 1a and 1b, both of which are made of non-magnetic material such as aluminum or plastics. The casing 1 is adapted to be connected to a fluid supply line and has a central axial passage therethrough. The axial passage in the casing 1 is partially enlarged to form a valve chamber 2, in which a valve body 3 made of magnetic material is movably disposed. Provided externally around the casing 1 is an annular magnetic member 4 which is urged toward an annular flange 1c on the casing 1 by an extensible coil spring 5. In the position shown in FIG. 1, the magnetic member 4 is shifted against the spring force and set to this inoperative position by a locking means 7, described hereinafter in detail. One of the valve body 3 and the annular magnetic member 4 is made of a permanent magnet. In this embodiment, the annular magnetic member is made of a permanent magnet, so that the magnetic attractive force is developed between the annular magnetic member 4 and the valve body 3. Due to such magnetic attractive force, in the inoperative position shown in FIGS. 1(a)-1(d), the valve body 3 is separated from a valve seat 6 and bears on a stopper 6a to allow the fluid material such as gaseous fuel to flow through the central axial passage.
The locking means 7 for holding the annular magnetic member or permanent magnet 4 to the inoperative position against the spring 5 comprises a ring 7a mounted to the annular magnet 4 and a pair of metal straps 8 each having a hook 8a at the free end thereof engagable with the ring 7a. The metal strap 8 is made of a leaf spring and connected at the other end thereof to an electrically insulative member 9 in a cantilever manner. The member 9 is attached to the outer peripheral surface of the casing 1. The hook 8a at the free end of the metal strap has a semi-circular recess in which the ring 7a is snugly received. The metal strap 8 retains an elasticity tending to flex inwardly in a direction to separate from the ring. Such inward flexion or movement of each metal strap 8 is prevented by a bridge-shaped bimetallic strap 10 mounted on the insulative member 9 as best shown in FIG. 1(d). The bridge-shaped bimetallic strap 10 upholds the metal strap in such a manner that the metal strap 8 crossing over the bimetallic strap 10 is slightly bent outwardly at the cross point 10a and that the hook 8a at the free end of the metal strap is resiliently engaged with the ring 7a.
Each bimetallic strap 10 has lead wires (not shown) connected to both of the ends thereof. An electric current is supplied to the lead wires through movable contacts 11a mounted on the annular magnetic member 4, i.e. permanent magnet, and fixed contacts 11b provided on the insulative member 9, both contacts being connected with each other in the inoperative position shown in FIGS. 1(a)-1(d). The lead wire from the bimetallic strap 10 as well as a lead wire from the movable contact is connected to an electric power source through a relay operated by a detector for leaked gas, earthquake or the like, as shown in FIG. 4.
Although not shown in the drawings, the metal strap 8 is coated with an electrical insulative material at the underside intersecting with the bimetallic strap so as to electrically insulate the bimetallic strap from other metallic parts of the device.
In such an inoperative position of the present device, when an electric current is supplied to the bimetallic straps 10 by the action of the detector for leaked gas, earthquake or the like, each bimetallic strap 10 generates heat in itself by the supplied electric current and starts bending inwardly. Therefore, as shown in FIGS. 2(a)-2(d), the bridge shape of the bimetallic strap 10 is immediately collapsed by the stress inwardly applied to the top of the bridge by the metal strap 8, which tends to bend inwardly due to its own elasticity. Thus, the bimetallic straps 10 are flattened and the metal straps 8 are moved inwardly, with the result that the hooks 8a at the free ends of the metal straps are disengaged from the ring 7a on the annular magnet 4. By this disengagement of the hooks 8a from the ring 7a, the annular magnet 4 is shifted toward the annular flange 1c by the action of the spring 5. Accordingly, the valve body 3 in the valve chamber 2 is also shifted by the magnetic attractive force of the magnet 4 and rests upon the valve seat 6 to interrupt the flow of the fluid material through the axial center passage of the casing 1. At this time, the movable contacts 11a are separated from the fixed contacts 11b, so that the supply of the electric current to the bimetallic straps is also interrupted.
It is preferable to use the present device in connection with a gas alarm 12 as shown in FIG. 3. The gas alarm 12 is composed of a detector 12a for leaked gas and a buzzer 12c actuated by means of a normally open contact P associated with the detector 12a. The detector is a known one made of a semiconductor. When the detector 12a detects the leakage of gas, due to the change of conductivity of the semi-conductor thereof, the contact P associated with the detector is closed, whereby the alarm sound is generated by an electric current supplied from the electric source 12b. Simultaneously, the electric current is supplied also to the bimetallic straps of the present device, so that the present device is operated to interrupt the flow of the gaseous fuel therethrough. Once the present device is operated, it keeps taking the operated position even after the gas detector 12a returns to the normal inoperative or non-detecting conditions. Then, after completely resolving the problems of gas leakage, the annular magnet 4 is pushed back against the spring 5 and set to the locking position by engaging the hooks 8a of the metal straps 8 with the ring 7a on the magnet 4.
FIG. 4 shows a practical manner how to connect the present device 13 with the gas alarm 12 and the electric power source 12b. Thus, in the present invention, no electric current is required to maintain the inoperative position of the present device. When used in connection with the known gas alarm, only a small amount of electric current is supplied continuously to the alarm but not to the present device. Also, no electric current is required to maintain the operative position of the present device, so that the consumption of the electric power is negligible in the present device. Although it is shown in FIGS. 3 and 4 to use alternating current as the electric power source of the present device, the power source may be dry batteries in case the bimetallic strap is formed into a narrow lead shape.
In another embodiment of the present invention shown in FIG. 5, the present device is made to be operated by detecting an earthquake. To this end, a mercury switch 14 is provided in connection with the present device. The mercury switch 14 is provided in series between the electric power source and the bimetallic strap 10, whereby when the switch 14 is closed by inclination thereof due to an earthquake, the electric current is supplied to the bimetallic strap 10 to operate the device in the same way as set forth above.
Although the present invention has been described with reference to the preferred embodiments thereof, many modifications and alterations may be made within the spirit of the present invention. For example, the movable valve body 3 in the valve chamber 2 may be any shape other than ball shape. Also, the present device can be used to shut off not only gaseous fuel but also other gases and liquids. | 4y
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BACKGROUND OF THE INVENTION
The reproduction of continuous tone images is, and has been for a considerable number of years, a major concern in the photographic arts.
A continuous tone image is a positive or negative image, e.g., an opaque print or transparency which is composed of a range of densities from black through gray to white, wherein the grays are formed by forming varying amounts of colorant, e.g., silver compounds, dye or pigment. A continuous tone reproduction contrasts with a line reproduction which is composed of only two tones, black (or a color) and a background color, e.g., white. The same applies to multi-color line images; although there are several colors, each is present only in one depth. The instant invention is directed to a method of half-tone reproduction which simulates a continuous tone image. The term "simulates" is used herein inasmuch as a half-tone image, when viewed at the correct distance, appears to be the result of varying densities. Upon closer examination, however, it becomes obvious that the densities are in fact integrated areas of black and white.
Of the various ways of creating half-tone images, one of the most well known is by screening. A half-tone screen is a line or dot pattern used to convert the continuous tones of varying darkness in a photograph, etc., into a discontinuous pattern of constant density but varying area. In a half-tone image lighter or darker tones are reproduced by smaller or larger dots or lines --which, through being uniformly spaced, occupy a greater or lesser proportion of a given unit area.
Half-tone images can be produced in many ways; the most usual is to convert the continuous tone into a regular dot pattern. In the past, several different structures have been used to produce this pattern, e.g., cross-line screens, gauze, linen and wire. When a cylindrical lenticular lens as proposed herein is used to create a soft line pattern on an imaging member, a "zipper-toned" image is created which is closely related to the well-known soft dot pattern.
The instant invention calls for the use of a lens system for producing the screening effects set forth above. A perfect lens is one which most nearly shows an image of a point as a point and a straight line as a straight line, subject to the faults, or aberrations, inherent in any lens which tend to reproduce a point as a patch, and a straight line as a more or less curved band.
Aberrations which affect an image point on the axis of the lens are classified as axial aberrations. The principal axial aberrations are chromatic and spherical.
Chromatic aberrations merely reflect the fact that a single lens made from a single type of an optical glass will refract blue rays more strongly than green rays, which in turn are refracted more strongly than red rays. Thus, a three-dimensional special positioning of the colored rays results and is referred to as chromatic aberration. Spherical aberration involves the phenomenon that rays coming from an object on the axis of a lens and going through the center of the lens come to a focus at a certain point on the axis of the lens. Rays from an axial object going through the lens near the edges should come to a focus at the same point, but in practice, because of spherical aberration, they tend to come toward a different point of focus. The difference between these focal points is the spherical aberration of the lens. Spherical aberration inceases with the lens aperture. In a simple converging lens, spherical aberration causes the rays farthest from the lens axis to convert more strongly, and to come to a focus nearer the lens than the central rays close to the lens axis. The image is never fully sharp. Spherical aberration does not vary with image size, but with the square of the aperture.
One additional known method used to screen images is the employment of a lenticular lens array. Such an array is one which uses a lenticular screen to break up an image into linear and area components which are subsequently recombined. The purpose of splitting is usually to accommodate two or more images interspersed in each other on the same area. Uses of a lenticular screen or lenticular array are usually for lenticular color photography, stero photography, image disection and multiple image storage. For example, see U.S. Pat. No. 3,413,117, which, in FIG. 7, discloses the use of a lenticular screen in an image deformation system. This patent is specifically concerned with the formation of color images in a thermoplastic deformation system, and requires the creation of relatively perfect images on the surface of the imaging member. The perfection of the image is indicated by the statement therein that " . . . light incident upon each area under each lens-like embossing 36 reacts with the recording layer to provide a stress pattern having a point-to-point correspondence with the image pattern . . . ." Furthermore, it is noted that this patent specifically calls for contact between the lenticular element and the image receiving surface, and that the read-out system is illumination through the film and lens with, or without, Schlieren optics. Also see U.S. Pat. Nos. 1,746,584, 992,151 and 1,749,278.
Generally, the main component of a lenticular system is the lenticular screen itself, consisting of a transparent support embossed with a regular pattern of lens surfaces. Usually these are cylindrical running across the screen in one direction as strips. While several obvious materials are suitable for construction of such a lens, usually they are made of plastic. By embossing a second set of linear elements that run at angles to the first, a lenticular screen consisting of individual lens elements is obtained. Additionally, it should be noted that lenses of this type can be made by any of a number of processes including embossing, extrusion and casting.
When a lenticular screen is placed in front of, and in contact with, the surface on which the camera lens projects an image, the individual lenticular elements break up the image into lines or points. They concentrate the image components into a smaller area, leaving spaces between them. Additional images can be recorded in the spaces by slightly displacing the lens laterally or by moving the object in front of the lens. The record or recorded image then contains a series of interlaced images which can be reconstituted by observation through a similar lenticular screen. The lenticular screen breaks up the image into line elements with spaces in between. If the screen is moved, a new set of line elements is formed in the spaces between the first set.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially schematic, partially cross-sectional view of a cylindrical-type lenticular lens element.
FIG. 2 is a schematic diagram of an imaging system employing the method of the instant invention.
FIG. 3 is a graph showing the idealized variation in light intensity across the imaging member when processed according to the instant invention.
FIG. 4 is a schematic, partially cross-sectional view of an imaging system employing a lenticular element in reverse position to that shown in FIG. 2.
FIG. 5 is a graph showing the relationship between the original density and the reproduction density of an exemplary imaging system undergoing different exposures corresponding to different density ranges.
BRIEF DESCRIPTION OF THE INVENTION
It is an object of this invention to provide a method of extending the dynamic range of imagewise exposure systems.
It is a further object of this invention to provide a method of screening continuous tone images.
It is a further object of this invention to provide a method of screening continuous tone images using lenticular elements either out of, or in, contact with the imaging member.
It is a still further object of this invention to provide a method of screening continuous tone images wherein the loss of light due to reflection or absorption of light by the screen is, for all practical purposes, eliminated.
It is an even still further object of this invention to provide a method of screening which requires the creation of imperfect images of the imaging lens on the photosensitive surface of the imaging member.
These, and other, objects are obtained by providing a method for extending the dynamic range of imagewise exposure systems by transmitting the electromagnetic radiation image through a lenticulr lens array and then to a photosensitive surface so that the image at the photosensitive surface is imperfect.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As stated above, lenticular elements are not new in photographic screening systems. Lenticular elements themselves are very old in the art and can take many various structural configurations. For example, FIG. 1 shows a cylindrical lenticular lens. Another well known lenticular lens is similar to FIG. 1; however, an additional cylindrical system is imposed thereon with the elements running at angles to those shown in FIG. 1. The resulting structure approaches what is called a spherical lenticular lens if the relative angle between the arrays is 90° and is, from a plain view, made up of relatively spherical-like projections. Relative angles greater than, or less than 90° produce different shaped projections. It can be seen, therefore, that when the term "lenticular" is used, it is meant to include a number of different structures.
Most of the methods that increase the tonal information in a given photographic system are inefficient. This inefficiency is caused by the opaque optical screen or optical filter which must absorb or reflect some of the light so that the highlights are not "burned out" by the longer exposure time required. The lens of the instant invention does not exhibit these characteristics inasmuch as it transmits substantially all radiation presented to it to the imaging member.
The half-tone image reproduction system herein proposed is of much higher efficiency than the prior art system described above. Attention is directed to FIG. 2 wherein one embodiment of the system of the instant invention is shown. An imaging lens 2, which images electromagnetic radiation e.g., light rays 3, through aperture 4, is positioned adjacent the lenticular element 1. The lenticular element 1 is interposed between lens 2 and the light image receiving surface 5 which is photosensitive to radiation 3. Note that the lenticular element 1 is not in contact with the image receiving surface 5, but rather is spaced some distance therefrom. This distance is determined by the various structural parameters of the element 1 and can take any practical value so long as the image remains imperfect.
Since the invention is concerned with half-toned reproduction, it is necessary that the screening structure produce a soft line or the well-known soft dot pattern, i.e., a dot of varying intensity from the center to the edge. A lenticular element which produces perfect images provides a system with high sensitivity (see copending U.S. Patent applications: Ser. Nos. 429,446 and 429,445, both filed on Dec. 28, 1973 IMAGING SYSTEM, filed concurrently herewith), while a lenticular element which produces imperfect images (see copending U.S. Pat. application Ser. No. 429,243, filed Dec. 28, 1973 provides s system with greater acceptance, i.e., extended range. A lenticular element which produces an imperfect image does not focus the impinging light into a sharp dot, but rather creates one which is of varying intensity as explained below in regard to FIG. 3.
The two preferred ways to create the above-described "imperfect image" are set forth below. One is to use an optically imperfect lens in relative focus with the photosensitive surface. The other is to use an optically good lens out of focus with the surface. An optically poor lens is one of such quality that the resolution of a given lenticule, in line pairs per millimeter, is less than or equal to the lens frequency in line pairs per millimeter. An optically good lens out of focus would be one in such a condition that its resolution limit is less than or equal to the number of lenticules per inch.
The Intensity vs. Distance graph of FIG. 3 exemplifies the ideal characteristics of a cylindrical lens. The image outside the lenticule is such that in one quarter (Y) of the distance under the lens (X), the intensity is approximately 4 times greater than the intensity of the remaining three-fourths of the distance, and that the intensity of the three-fourths of the area is reduced from about 1.75 units (J) to about 1.0 units (I). In other words the distance I is 0.75 density units smaller than the intensity without the lens J.
Further by way of example, let us look at the exposure of an amorphous selenium photoconductive layer of the type used in conventional commerical xerography using an array of cylindrical lenticulated lenses. Amorphous selenium xerography has a density input range of approximately 0.6 density units which, when used with the concepts of the instant invention, will be increased to about 1.2 density units. The three-fourths of the area under the lenticule which received one-fourth of the density will be used to record the shadow information and the remaining one-fourth of the area will be used to record the highlight information.
For a better understanding of the concepts and value of the instant invention, attention is directed to the graph of FIG. 5 which shows the relationship between the density of the original, D O , and the density of the reproduction, D R , in an unscreened system. It is helpful to compare this graph with the one of FIG. 3 and consider the imaging members to be the same. Using the same exposures as used in FIG. 3 produces a density relationship according to curve a, which reaches a maximum value corresponding to the dotted line J in FIG. 3. The copy content represented by curve a is useful in reproduction systems; however, it does not have the capability of reproducing the highlight information of the original. Now, if a higher level of exposure is used, a density relationship according to curve b is produced which also reaches a maximum value and corresponds to value Z in FIG. 3. Note that the curve b represents a higher density of the original, and, obviously contains more highlight information. In other words, curve b contains highlight information which curve a does not, but does not contain the same amount of shadow information.
Therefore, it can be seen that exposure through the inventive screen will give density information covering an extended range greater than any exposure level taken alone.
The lens can be designed to give any type of quasi-step function or continuous curve to give the desired half-toned image.
The quality of the image presented to the photosensitive surface of the imaging member is important to the instant invention. The prior art systems are all directed to the transmission of an image which is as near perfect as possible, while the instant invention intentionally does contrary. The desired imperfect image is obtained by either using an optically good lenticular lens array out of focus, or an optically poor lenticular lens array substantially in focus. In the former situation, it is also possible to vary the size of the dot or line by moving the lens element with respect to the recording medium.
Lenticular element 1 is illustrated in the figures as being out of contact with the imaging member; however, it is important to note that embodiments can be made which have contact between the two elements and in which they form an integral member. It is important only that an imperfect image be created.
The developed image is normally viewed otherwise than through the lenticular lens array. This is especially true in the embodiments wherein there is no contact between the array and the imaging member. However, in those embodiments which have contact, it is possible to view the developed image through the lens.
Generally, there is no limitation on the number of lenticules per millimeter; however, a preferred mode would require the number of lenticules per inch to have about 21/2 times the frequency of the image to be resolved.
The system of the instant invention produces, at the expense of resolution, an increase in density input which is equal to the density difference between light and dark areas. Or, more specifically, the increase equals log 10 of the ratio of the maximum intensity and minimum intensity of the lens.
As noted herein, lenticular lenses are not new in the art and can be purchased to order from numerous sources, for example, Photosystems Corporation of Hauppauge, N.Y.
The advantageous invention of the instant application can be applied to any photosensitive imaging system. Photosensitive imaging members include all such members which attribute their functionability to a sensitivity to activating radiation.
Although specific apparatus and process steps have been described, other elements and steps may be used where suitable.
It will be understood that various changes in details, materials, steps and arrangement of parts, which have herein been described and illustrated in order to explain the nature of the invention, will occur to and, may be made by those skilled in the art upon a reading of the disclosure within the principles and scope of the invention.
For example, by selection of lenses with differing optical parameters, it is possible to position the lens other than shown in FIG. 2, as, for instance, shown in FIG. 4. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a hinge for a refrigerated display case, and, more particularly, to a hinge for a refrigerated display case which is adapted to pivot a door, such as a glass door, about a horizontal axis and hold the door in an upward open position.
2. Description of the Related Art
A refrigerated storage cabinet, such as a chest freezer, includes a top door which pivots about a horizontal axis at the rear of the chest freezer. When loading items into or removing items from the chest freezer, it is necessary that the door remain in an upward open position. To maintain the door in the open position, it is known to utilize a tension spring in conjunction with the hinge, whereby the door is held in the open position.
Refrigerated display cases typically include a glass front wall so that a customer may view the items stored therein. To improve the thermal efficiency of such a display case, the glass door may be formed from thermopane glass, i.e., double pane glass. The thermopane glass door may be hinged at a top edge thereof, and pivot about a horizontal axis. Such thermopane glass is quite heavy when compared with single pane glass, and therefore may be difficult to hold in an open position when loading items into or removing items from the display case, or when cleaning the interior of the display case.
One solution for maintaining a thermopane glass door of a refrigerated display case in an open position is to utilize a hinge equipped with a gas cylinder for biasing the thermopane glass door to the open position. Such a device is disclosed by U.S. Pat. No. 5,116,274 (Artwohl et al). To attach the hinge to the glass, a clamp assembly having two pieces is utilized. The first piece is rigidly attached to the hinge, and a second piece is adjustably connected to the first piece, and coacts with the first piece to sandwich an upper edge of the glass door therebetween.
A problem with a hinge which biases a thermopane glass door to an open position utilizing a gas cylinder is that the gas cylinder has a relatively limited life span. Typically, after a few thousand cycles of opening and closing, the gas cylinder may fail and need to be replaced. Such replacement of the gas cylinder increases the maintenance costs associated with the refrigerated display case. Moreover, upon failure of the gas cylinder, the glass door may no longer be biased to an open position and cause an inconvenience to customers because of the necessity to manually hold the glass door open. Additionally, failure of the gas cylinder may pose a possible safety hazard if the door should fall to the closed position via gravitational force.
What is needed in the art is a hinge assembly for a refrigerated display case which effectively engages the glass door, and biases the glass door to an open position with increased reliability.
SUMMARY OF THE INVENTION
The present invention provides a hinge assembly including a spring biased hinge and a clamp for frictionally engaging a glass door, and having increased reliability over known structures.
The invention includes, in one form thereof, a hinge assembly for interconnecting a frame and a glass door of a refrigerated display case. The hinge assembly is pivotable about a horizontal axis and includes a hinge movable between a first position and a second position. The hinge includes a spring biasing device for biasing the hinge into the first position or second position. A clamp is connected to the hinge and holds the glass door using only frictional force.
An advantage of the present invention is that a horizontally pivoting glass door of a refrigerated display case can be maintained in an open position with increased reliability.
Another advantage is that the hinge assembly is capable of maintaining the door in an upright position for a greater number of operational cycles, and thereby reduces maintenance costs associated with the refrigerated display case.
BRIEF DESCRIPTION OF THE DRAWINGS
The above-mentioned and other features and advantages of this invention, and the manner of attaining them, will become more apparent and the invention will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein:
FIG. 1 is a perspective view of an embodiment of the hinge assembly of the present invention;
FIG. 2 is a side sectional view of the embodiment of FIG. 1, shown attached to an upper frame member and glass door of a display case; and
FIG. 3 is a top view of the embodiment shown in FIG. 1, shown attached to a glass door.
Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate one preferred embodiment of the invention, in one form, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and more particularly to FIGS. 1-3, there is shown a hinge assembly 10 of the present invention which is adapted for use in a refrigeration display cabinet including a top frame member 12 of a frame 14, and a glass door 16. In the embodiment shown, glass door 16 is a thermopane glass door, i.e., double pane glass door, and is pivoted about a horizontal axis at an upper edge 18 thereof.
Hinge assembly 10 generally includes a hinge 20 and a clamp 22. Hinge 20 includes a generally U-shaped mounting bracket 24 secured to an underside of top frame member 12 by suitable means, such as a plurality of threaded bolts 26, one of which is shown in FIG. 2. Clamp 22 includes a first part 28 and a second part 30 which are of extruded metal and extend along the entire length of upper edge 18 of glass door 16. In the embodiment shown, a hinge 20 is disposed approximately every two feet along the length of, and attached to, clamp 22. However, it is to be appreciated that the relative spacing between each respective hinge 20 may vary. For purposes of discussion, a single hinge 20, as shown in FIGS. 1-3, is described herein.
Mounting bracket 24 includes a bottom plate 31 with a pair of depending legs 32, 34 extending upwardly therefrom. Disposed at the top of each respective leg 32, 34, and extending outwardly therefrom, are respective depending flanges 36, 38. Flanges 36, 38 include internally threaded bosses 40 for threadedly receiving threaded bolts 26. Extending downwardly from each flange 36, 38 is a respective shoulder 42, 44 adapted for connection to a top shelf trim piece 46 by suitable means, such as threaded bolts 48, one of which is shown in FIG. 2.
A pivot plate 50 is pivotally connected to uprights 51 of mounting bracket 24 via a rod 52. More particularly, pivot plate 50 includes a first vertically extending member 54 and a second vertically extending member 56 with respective openings (not numbered) therein for receiving rod 52. Extending between and interconnecting first vertically extending member 54 and second vertically extending member 56 is a transverse plate 58 having a plurality of openings 60 formed therein.
Clamp 22 is attached to pivot plate 50 of hinge 20. To wit, first part 28 includes a plurality of internally threaded openings 62 which are disposed in coaxial alignment with openings 60 of transverse plate 58. Respective bolts 64 pass through openings 60 and are threadedly received within openings 62.
Second part 30 of clamp 22 is adjustably connected to first part 30, whereby an adjustable clamping force may be exerted upon upper edge 18 of glass door 16. In particular, first part 28 includes a female concave portion 66 which extends parallel with and is spaced apart from upper edge 18 of glass door 16. Moreover, second part 30 includes a male convex portion 68 which extends parallel with and is spaced from upper edge 18 and mates with female concave portion 66. Female concave portion 66 and male convex portion 68 define a pivot point about which first part 28 and second part 30 may pivotally move relative to each other. Disposed between female concave portion 66, male convex portion 68 and upper edge 18 are a plurality of bolts 70 which extend through respective openings 72, 74 of first part 28 and second part 30. Bolts 70 threadably receive a nut 76; however, it is to be understood that one or the other of openings 72, 74 could be threaded and nut 76 eliminated.
As is apparent upon an examination of FIG. 2, tightening nuts 76 on bolts 70 causes first part 28 and second part 30 to pivot relative to each other about the pivot point defined by female concave portion 66 and male convex portion 68, whereby an adjustable clamping pressure may be exerted upon upper edge 18 of glass door 16. Preferably, an elastomeric seal 78 is disposed between upper edge 18 and each of first part 28 and second part 30 to act as a seal and to provide a cushion therebetween.
Second part 30 of clamp 22 includes a recess 80 at an edge thereof which is disposed adjacent to top shelf trim piece 46. A seal 82 is disposed in recess 80 and forms an effective seal between clamp 22 and top shelf trim piece 46.
Referring now to FIGS. 1 and 3, a spring biasing assembly 82 biases pivot plate 50 to maintain glass door 16 in an open position for loading items into or removing items from the refrigerated display case. Pivot plate 50 of hinge 20 is movable to a first, e.g., closed position (such as shown in FIG. 2), and a second, e.g., open position (not shown) wherein glass door 16 is pivoted upwardly for loading or removal of items from the refrigerated display case. Spring biasing assembly 82 includes a curved plate member 84 which is pivotally attached at one end thereof to first vertically extending member 54 and second vertically extending member 56 via rod 86. More particularly, curved plate member 84 includes a bore formed therein (not shown) through which rod 86 extends.
At an edge of curved plate 84 disposed opposite from the edge having the bore for receiving rod 86 is a generally planar face 88 (FIG. 3) having three internally threaded openings (not shown) for threadably receiving elongated threaded members 90, 92 and 94. Threaded members 90, 92 and 94 extend through end plates 96, 98 and carry respective compression springs 100, 102 and 104 radially thereabout. Referring to FIG. 1, end plate 96 includes outwardly extending tabs 106 which extend through rectangular openings 108 formed in depending legs 32, 34. Each of elongated threaded members 90, 92 and 94 is threadably engaged at one end thereof with the threaded openings formed in planar face 88, as shown in FIG. 3. Elongated threaded members 90 and 94 include a slotted head for rotating threaded members 90 and 94 into threaded engagement with curved plate member 84. Similarly, threaded member 92 includes a hex head for rotation thereof. Each of threaded members 90 and 94 slidably pass through an opening formed in end plates 96, 98. In contrast, threaded member 92 threadably engages an internally threaded boss 110 of end plate 98, whereby upon rotation of threaded member 92 end plates 96 and 98 may be moved relative to each other along a longitudinal direction of threaded members 90, 92 and 94. By moving end plates 96, 98 relative to each other, a desired preset can be placed upon compression springs 100, 102 and 104, whereby a desired lifting force can be exerted upon glass door 16 when in the upright position.
In operation, with door 16 of the display case in a downwardly closed position, as shown in FIG. 2, seals 78 and 82 of hinge assembly 10 effectively maintain a thermal seal to prevent excessive heat transfer. In the closed position, compression springs 100, 102 and 104 are in a compressed state. When door 16 is raised to an upwardly, open position, pivot plate 50 pivots about rod 52 and relative to mounting bracket 24, whereby glass door 16 is in a vertically upward position. During rotation of pivot plate 50, rod 86 likewise rotates downwardly about rod 52 into a lowered position and causes planar face 88 of curved plate member 84 to move in a generally longitudinal direction along threaded members 90, 92 and 94 and away from end plate 96. As curved plate member 84 moves in a generally axial direction along threaded members 90, 92 and 94, end plate 98 and springs 100, 102 and 104 pivot slightly at tabs 106 of end plate 96 within rectangular openings 108. Each of threaded members 90, 92 and 94 are slidably disposed within end plate 96 and thus end plate 98 moves away from end plate 96 and allows expansion of springs 100, 102 and 104. The force exerted on curved plate member 84, and in turn pivot plate 50, by the expanded compression springs 100, 102 and 104 is sufficient to maintain glass door 16 in the upright, open position. To close the door, a user simply pulls in a downwardly direction on glass door 16, which pivots rod 86 upwardly about rod 52 to force end plate 98 towards plate 96 to compress compression springs 100, 102 and 104, thereby allowing glass door 16 to move to the downwardly closed position.
While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims. | 4y
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FIELD OF THE INVENTION
[0001] This invention relates to a steering column locking device. More specifically, this invention relates to a steering column locking device for golf carts, and the like.
BACKGROUND OF THE INVENTION
[0002] Steering column locking devices are used to prevent vehicle theft. While many such devices have been created for automobiles, relatively few theft protection devices for golf carts exist. One such example of a golf cart anti-theft device is described in U.S. Pat. No. 5,460,021 and is hereby incorporated by reference. Multiple examples of steering column lock devices for automobiles are described in U.S. Pat. No. 7,234,328 B2, U.S. Pat. No. 7,364,198 B2, and U.S. Pat. No. 7,316,138 B2, which are hereby incorporated by reference.
[0003] Unless securely locked inside a building, golf carts remain substantially unprotected against theft. Further, steering column locking devices for automobiles cannot simply be transferred to a golf cart. Differences in the size and shape of the respective vehicles' steering columns create just one of the difficulties presented in attempting to use an automobile steering column locking device on a golf cart.
[0004] Accordingly, there remains a need for a steering column locking device that may be used on golf carts to effectively prevent theft.
SUMMARY OF THE INVENTION
[0005] The embodiments of the invention and the method described herein address the shortcomings of the prior art.
[0006] In general terms, the invention may be described as including the following:
[0007] A steering column comprising: (a) a sleeve portion having an open bore or space extending the length of said sleeve portion; (b) a steering shaft portion disposed within the sleeve portion, and adapted to rotate within said sleeve portion, and having at least one terminal end portion extending beyond the sleeve portion; (c) a main body portion fixed about the sleeve portion having (i) a central aperture extending through the main body adapted to receive the sleeve portion; (ii) a groove about the central aperture extending partially through the main body; (iii) a locking aperture extending through the main body and extending into the groove; (iv) a locking mechanism extending through the locking aperture so as to allow all or some portion of the locking mechanism to extend through the groove, which locking mechanism is adapted to be reversibly removed; (d) a second body portion having (i) a perimeter wall, (ii) a bottom end, and (iii) a top end; (iv) at least one side opening extending partially or completely through the perimeter wall and positioned so as to allow the locking mechanism of the main body portion to extend into the at least one side opening; the bottom end having a portion extending into the groove of the main body portion, the bottom end being adapted to rotate with respect to the main body portion between an unlocked position wherein the locking aperture and the at least one side opening are not aligned and a locked position wherein the locking aperture and the at least one side opening are aligned; and the top end having an opening.
[0008] The sleeve portion may be any material such as a metal or a high strength plastic of sufficient strength for use in a security device of the type of the present invention. A number of different types of materials may be used for making the sleeve portion of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape. The sleeve portion may be cylindrical in shape or alternatively may have multiple faces. Similarly, the steering shaft may be any material such as a metal or a high strength plastic. A number of different types of materials may also be used for making the steering shaft of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape. The shaft may be cylindrical in shape or alternatively may have multiple faces.
[0009] In addition, the main body portion may be any stable material such as a metal or a high strength plastic. A number of different types of materials may be used for making the sleeve portion of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape. It may be fixed about the sleeve portion by means which may include, but are not limited to, an adhesive, soldering, shim piece, or through the use of a fastener, such as a screw, preferably one that is designed for relatively secure attachment, such as one-way or counter-sunk screw, that are relatively difficult to remove.
[0010] The central aperture extending through the main body may be any shape to receive the sleeve portion, preferably such that the two pieces fit snugly and securely together, in accordance with the security function of the invention.
[0011] The groove about the central aperture may be circular, so as to allow rotational movement of the bottom end portion of the second body portion within the groove. Preferably, the groove should not extend through the main body portion such as would compromise the security function of the system of the present invention. However, there may be one or more optional openings in the groove, such that water and other materials that may enter the groove, and escape through the openings.
[0012] The locking aperture extends through the main body and into the groove. The aperture may also extend through the groove. The aperture may be any shape so as to receive the locking mechanism.
[0013] The locking mechanism may shaped so as to fit into the locking aperture and may be secured within the locking aperture by adhesion, soldering, use of an interferant member, such as a pin, or other means appropriate to the security function of the device. It may be secured within the locking aperture by a pin inserted into the main body, extending through the locking aperture and through a groove on the locking mechanism. The locking mechanism operates so as to extend through the locking aperture and into the groove, thus engaging the lock. The mechanism may have a safety feature, which allows the mechanism to lock in its engaged position, so as to require an additional action to remove the locking mechanism from the groove, thereby disengaging or unlocking the device.
[0014] The second body portion may be any material such as a metal or a high strength plastic. A number of different types of materials may be used for making the second body portion of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape.
[0015] The second body portion may have at least one side opening extending partially or completely through the perimeter wall. The opening may be any shape such as to receive the locking member or mechanism when engaged and inhibit rotation of the bottom portion within the groove. The opening may be an aperture or may be an opening extending the length of the perimeter wall, or any combination thereof that will inhibit the rotational movement of the second body portion within the groove, when the locking mechanism is engaged.
[0016] The portion of the bottom end extending into the groove of the main body portion is circular in shape so as to allow it to rotate within the groove.
[0017] The present invention also includes an embodiment in which the opening in the top of the second body portion is shaped to receive the terminal end portion of the steering shaft portion and is fixed to the terminal end portion so as to cause the second body portion to rotate along with the rotation of the steering shaft portion. For example, the top may be triangular in shape or rectangular in shape. Accordingly, the terminal end portion will be a corresponding shape so as to fit into the top of the second body portion and cause the second body portion to rotate with the steering shaft portion.
[0018] In another embodiment, the terminal end portion of the steering shaft has one or more splines and the opening of the top end of the second body portion is shaped so as to receive the splined terminal end portion so as to cause the second body portion to rotate along with the rotation of the steering shaft portion. In other words, the engagement between the opening of the top end of the second body portion and the splined terminal end portion integrally rotates the second body portion with respect to the steering shaft.
[0019] The present invention also includes an embodiment wherein the top end of the second body portion comprises a removable portion that includes the opening of the top end. The removable portion and the portion of the second body portion from which the removable portion is removed may be threaded. Alternatively, the removable portion may be fixed in the second body portion by means which may include, but not limited to, adhesion or soldering.
[0020] In another embodiment, the central aperture is defined by at least one removable portion wherein the main body portion is shaped so as to hold removable portion(s) within the main body portion.
[0021] In yet another embodiment, the severable main body portion comprises a first portion and a second portion wherein the first portion is fixed to the second portion. The first and second portions may be fixed to one another by means including, but not limited to, one or more set screws, adhesion or soldering.
[0022] In another embodiment of the present invention, the terminal end portion of the steering shaft has one or more splines and second body portion is fixed to an adaptor having an aperture shaped so as to receive the splined terminal end portion so as to cause said second body portion to rotate along with the rotation of said steering shaft portion. In other words, the engagement between the aperture and the splined terminal end portion integrally rotates the second body portion with respect to the aperture.
[0023] The present invention also includes a locking system comprising: (a) a severable main body portion having (i) a central aperture extending through the main body; (ii) a groove about the central aperture extending partially through the main body; (iii) a locking aperture extending through the main body and extending into the groove; (iv) a locking mechanism extending through the locking aperture so as to allow all or some portion of the locking mechanism to extend through the groove, with such locking mechanism adapted to be reversibly removed; (b) a second body portion having (i) a perimeter wall, (ii) a bottom end, and (iii) a top end; (iv) at least one side opening extending partially or completely through the perimeter wall and positioned so as to allow the locking mechanism of the main body portion to extend into the at least one side opening; the bottom end having a portion extending into the groove of the main body portion, the bottom end being adapted to rotate with respect to the main body portion between an unlocked position wherein the locking aperture and the at least one side opening are not aligned and a locked position wherein the locking aperture and the at least one side opening are aligned; and the top end having an opening.
[0024] The severable main body portion may be any material such as a metal or a high strength plastic suitable to the security function of the device. A number of different types of materials may be used for making the sleeve portion of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape.
[0025] The central aperture extending through the main body may be any shape to receive the sleeve portion. Further, the groove about the central aperture may be circular, so as to allow rotational movement of the bottom end portion of the second body portion within the groove. The groove normally should not extend through the main body portion; although, there may be one or more openings in the groove, such that water and other materials that may enter the groove, and escape through the openings.
[0026] The locking aperture extends through the main body and into the groove. The aperture may also extend through to the interior side of the groove. The aperture may be any shape so as to receive the locking mechanism.
[0027] The locking mechanism may shaped so as to fit into the locking aperture and may be secured within the locking aperture by adhesion, soldering, use of an interferant member, such as a pin, or other means appropriate to the security function of the device. It may be secured within the locking aperture by a pin inserted into the main body, extending through the locking aperture and through a groove on the locking mechanism. The locking mechanism operates so as to extend through the locking aperture and into the groove, thus engaging the lock. The mechanism may have a safety feature, which allows the mechanism to [lock] in its engaged position, so as to require an additional action to remove the locking mechanism from the groove, thereby un-engaging or unlocking the device.
[0028] The second body portion may be any stable material such as a metal or a high strength plastic. A number of different types of materials may be used for making the second body portion of the present invention. Preferably, the material is aluminum that can be cast or machined into the desired shape.
[0029] The second body portion may have at least one side opening extending partially or completely through the perimeter wall. The opening may be any shape such as to receive the locking mechanism when engaged and inhibit rotation of the bottom portion within the groove. The opening may be an aperture or may be an opening extending the length of the perimeter wall, or any [combination] thereof that will inhibit the rotational movement of the second body portion within the groove, when the locking mechanism is engaged.
[0030] The portion of the bottom end extending into the groove of the main body portion is circular in shape so as to allow it to rotate within the groove.
[0031] The locking system may also be such that the opening of the top end is shaped to receive a terminal end portion of a rotatable steering shaft and is fixed to the terminal end portion so as to cause the second body portion to rotate along with the rotation of the terminal end portion.
[0032] The present invention also includes an embodiment in which the opening of the top end of the second body portion is shaped to receive a terminal end portion of a rotatable steering shaft and is fixed to the terminal end portion so as to cause the second body portion to rotate along with the rotation of the terminal end portion. For example, the top may be triangular in shape or rectangular in shape. Accordingly, the terminal end portion will be a corresponding shape so as to fit into the top of the second body portion and the engagement between the two causes the second body portion to rotate with the terminal end portion.
[0033] The present invention also includes an embodiment wherein the terminal bore is shaped so as to receive a splined terminal end portion of a rotatable column so as to cause the second body portion to rotate along with the rotation of the terminal end portion. In other words, the engagement between the terminal bore and the splined terminal end portion integrally rotates the second body portion along with the rotation of the column.
[0034] The present invention also includes an embodiment wherein the top end of the second body portion comprises a removable portion that includes the opening of the top end. The removable portion and the portion of the second body portion from which the removable portion is removed may be threaded. Alternatively, the removable portion may be fixed in the second body portion by means which may include, but are not limited to, adhesion or soldering.
[0035] In another embodiment, the central aperture is defined by at least one removable portion wherein the main body portion is shaped so as to hold the at least one removable portion within the main body portion.
[0036] In yet another embodiment, the severable main body portion comprises a first portion and a second portion wherein the first portion is fixed to the second portion. The first portion may be fixed to the second portion by means which may include, but are not limited to, an adhesive, soldering, shim piece, or through the use of a fastener, such as a screw, preferably one that is designed for relatively secure attachment, such as one-way or counter-sunk screw, that are relatively difficult to remove.
BRIEF DESCRIPTION OF THE DRAWINGS
[0037] FIG. 1 shows the steering column locking device on a golf cart, in accordance with one embodiment of the present invention.
[0038] FIG. 2 is a side view of the steering column locking device, in accordance with one embodiment of the present invention.
[0039] FIG. 2A is a detailed side view of the steering column locking device, in accordance with one embodiment of the present invention.
[0040] FIG. 3 is an perspective view of the steering column locking device.
[0041] FIG. 4 is an upper side exploded perspective view of the steering column locking device, in accordance with one embodiment of the present invention.
[0042] FIG. 5 is an exploded perspective exploded view of the main body portion and locking mechanism in accordance with one embodiment of the present invention.
[0043] FIG. 6 is a side perspective view of the steering shaft and at least one removable portion in accordance with one embodiment of the present invention.
[0044] FIG. 7 is a bottom side perspective view of the second main body portion in accordance with one embodiment of the present invention.
[0045] FIG. 8 is a cross sectional view of one embodiment of the present invention.
[0046] FIG. 9 is a cross sectional view of one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] In accordance with the foregoing summary, the following describes a preferred embodiment of the present invention which is considered to be the best mode thereof. With reference to the drawings, the invention will now be described in detail with regard for the best mode and preferred embodiment.
[0048] FIG. 1 shows steering column 1 on a golf cart.
[0049] FIG. 2 shows steering column 1 showing the position of main body portion 3 of a locking mechanism of the present invention.
[0050] FIG. 2A shows a larger view of steering column 1 having a steering shaft portion 2 and main body portion 3 fixed about steering shaft portion 2 . In the preferred embodiment, the main body portion will be fixed about the steering shaft portion by screws (not shown, but residing in counter sink aperture 4 ). The main body portion may be any stable material such as a metal or a high strength plastic. Preferably, the main body portion is 6061-T6 aluminum, machined into the desired shape. However, the present invention could also be constructed of a plastic that can be molded or machined into the desired shape.
[0051] FIG. 2A further shows main body portion 3 having portions 3 a and 3 b . In the preferred embodiment, main body portion 3 is machined into its desired shape, then divided into portions 3 a and 3 b by a machine. Preferably, portions 3 a and 3 b and fixed about steering shaft 2 and fixed to one another by screws (not shown, but residing in counter sink aperture 4 ). In the preferred embodiment, portions 3 a and 3 b are fixed to one another by tamper proof screws.
[0052] FIG. 3 is an upper plan view of the present invention, showing steering column 1 having a steering shaft portion 2 and main body portion 3 , having portions 3 a and 3 b , fixed about steering shaft portion 2 . FIG. 3 also shows counter sink aperture 4 .
[0053] FIG. 3 further shows locking mechanism 5 inserted into locking aperture 6 . Finally, FIG. 3 shows locking pin 7 . In the preferred embodiment, locking pin 7 is inserted into the main body portion 3 , and passes through a groove on the outside of locking mechanism 5 , thereby restricting movement of locking mechanism 5 with respect to the locking aperture 6 , and preventing removal of the locking mechanism.
[0054] FIG. 4 is an exploded view of the present invention and shows steering column 1 , steering shaft portion 2 , and main body portion 3 having a central aperture 8 , defined when main body portions 3 a and 3 b are fixed to one another. FIG. 4 shows tamper proof screws 4 a and 4 b , which, in the preferred embodiment, are threaded so as to engage with correspondingly threaded counter sink aperture 4 . FIG. 4 also shows locking mechanism 5 , locking aperture 6 , and locking pin 7
[0055] FIG. 4 also shows second body portion 9 having perimeter wall 9 a , at least one side opening 9 b , bottom end portion 9 c , and top end opening 9 d.
[0056] In the preferred embodiment, the present invention has shim pieces 10 , as shown in FIG. 4 . Shim pieces 10 are placed inside central aperture of the main body portion, and provide a closer fit with the steering shaft. Preferably, the shim pieces are also made of machined aluminum, however, other materials such as metal or a high strength plastic may also be used. In the preferred embodiment, the central aperture will have a bottom lip, with the bottom lip having a slightly smaller diameter, such that shim pieces may fit inside the aperture without sliding through the aperture. The resulting diameter of the shim pieces will preferably have a diameter that corresponds to the out diameter of the steering shaft about which the main body portion is fixed
[0057] FIG. 5 shows main body portion 3 having a central aperture 8 . Preferably, the central aperture is machined out of the main body portion prior to the division of the main body portion into two portions. The aperture typically will have a diameter that corresponds to the outer diameter of the steering shaft about which it is fixed.
[0058] FIG. 5 also shows main body 3 portion having a groove 11 . The groove 11 has a width 11 a that is preferably large enough to accommodate the bottom end portion of the second body potion. Typically, the groove may be machined out of the main body portion. Further, in the preferred embodiment, the groove should not extend through the main body portion, as that would sever the main body portion. Instead, it should only extend into the main body portion, but not through. Additionally, in the preferred embodiment, there may be one or more openings in the groove, such that water and other materials that may enter the groove can escape through the openings.
[0059] FIG. 5 also shows locking aperture 6 and locking mechanism 5 . In the preferred embodiment, the locking aperture opening is circular and the locking mechanism is cylindrical, with a circumference that corresponds to the locking aperture. In the preferred embodiment, the locking mechanism has a cylinder 5 b which may extend and retract by the insertion and rotation of a key 5 a into locking mechanism 5 .
[0060] FIG. 5 also shows a locking pin 7 that is inserted into pin hole 7 a . The locking pin passes through a groove in the locking mechanism, inserted into locking aperture, and inhibits the removal of the locking mechanism from the locking aperture. The pin may be inserted into the pin hole such that the top of the pin is flush with the main body portion, thus inhibiting easy removal of the locking mechanism.
[0061] FIG. 6 shows steering shaft 2 having a splined section 2 a and a threaded section 2 b . In the preferred embodiment, splined section 2 a inserts into an aperture with corresponding splines, thus causing steering shaft 2 to rotate with the steering wheel. A nut threads onto threaded section 2 b to prevent the steering wheel from lifting off the splined section.
[0062] FIG. 6 also shows shim pieces 10 a and 10 b . The approximate circumference of the arcuate shim pieces corresponds to the shaft circumference. In the preferred embodiment, the shim pieces are held to the shaft by pressure from the main body portion.
[0063] FIG. 7 shows second body portion 9 attached to and steering wheel 12 . Second body portion 9 has side openings 9 b 9 ba 9 bb and 9 bc . In the preferred embodiment, the side openings are slightly larger than the locking pin, so as to allow the locking pin to insert into the opening and thus inhibit the rotation of the steering shaft. In other embodiments, the openings may be larger, although that will allow greater rotational movement of the steering shaft when the locking mechanism is engaged. In addition, the openings may be larger longitudinally, which would allow leeway in mounting of the main body portion.
[0064] FIG. 8 shows a cross section view of the steering column 1 . FIG. 8 shows locking mechanism 5 in the unlocked, unengaged position, as locking pin 5 b is shown withdrawn from side opening 9 b of the second body portion 9 . Thus the second body portion is free to rotate within groove 11 of main body portion 3 .
[0065] FIG. 8 also shows a third body portion 13 having a shaft opening 13 a . FIG. 8 shows steering shaft 2 inserted through the top aperture 9 d of the second body portion, into shaft opening 13 a of the third body portion 13 , where the splined portion 2 a of steering shaft 2 is inserted into corresponding splined shaft opening 13 a of third body portion 13 .
[0066] FIG. 9 shows a cross section view of steering column 1 , but with locking mechanism 5 in the engaging. In the preferred embodiment, the locking mechanism operates to insert the locking rod into an opening in the second body portion, as a key is turned. The locking rod is reversibly removed when the key is turned in the opposite direction. In the preferred embodiment, the locking rod passes through the side opening of the second body portion, inhibiting rotational movement of the steering shaft. In another embodiment, the locking rod may enter the second body portion, but not pass all the way through. It is also possible for the locking rod to pass through the second body portion, through an opening on the main body portion and touch the steering shaft. | 4y
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a signal evaluation method for detecting QRS complexes in electrocardiogram (ECG) signals.
2. Background Art
Regarding the background of the invention, it can be stated that the automatic analysis of ECG signals is playing an increasingly larger role in perfecting the functionality of cardiac pacemakers and defibrillators. Newer models of implantable cardiac devices of this type accordingly also offer the capability to perform an ECG analysis. The detection of QRS complexes and R spikes in ECG signals plays an extremely important role in this context. This significance results from the many and diverse applications for the information concerning the time of occurrence of the QRS complex, for example when examining the heart rate variability, in the classification and data compression, and as the base signal for secondary applications. QRS complexes and R spikes that are not detected at all or detected incorrectly pose problems with respect to the efficiency of the processing and analysis phases following the detection.
A wide overview of known signal evaluation methods for detecting QRS complexes in ECG signals can be found in the technical essay by Friesen et al. “A Comparison of the Noise Sensitivity on Nine QRS Detection Algorithms” in IEEE Transaction on Biomedical Engineering, Vol. 37, No. 1, January 1990, pages 85-98. The signal evaluation algorithms presented there are based throughout on an evaluation of the amplitude, the first derivation of the signal, as well as its second derivation. For the presented algorithms, the essay distinguishes between those that perform an analysis of the amplitude and the first derivation, those that analyze only the first derivation, and those that take into consideration the first and second derivation. To summarize briefly, all algorithms check whether the given signal parameter exceeds or falls short of any predetermined thresholds, after which, if such an event occurs, the occurrence of additional defined events is checked based on a predefined pattern, and if certain criteria are fulfilled, the conclusion is drawn that an QRS complex is present.
Another aspect in the signal evaluation for detecting QRS complexes needs to be taken into account when methods of this type are implemented in implanted cardiac devices. In view of the natural limitations of these devices regarding their energy supply and computing capacity, it is important that the detection of QRS complexes can be performed with the simplest possible algorithms with the fewest possible mathematical operations on the basis of whole numbers instead of real numbers.
Signal processing methods from the fields of linear and non-linear filtering, wavelet transformation, artificial neural networks, and genetic algorithms have also been applied in the QRS detection. With large signal-noise distances and non-pathological signals, i.e., when good signal conditions are present, these evaluation methods produce reliable results. When no such conditions were present, the efficiency of the evaluation processes could drop drastically, which, of course, is not acceptable with regard to the reliable operation of a pacemaker.
SUMMARY OF THE INVENTION
Based on the described problems, the invention has as its object to present a signal evaluation method for detecting QRS complexes in ECG signals that can be used with a comparatively low computing capacity and also with problematic signal conditions while producing reliable detection results.
This object is met with the process steps according to the invention as follows:
sampling of the signal and conversion to discrete signal values in chronological order,
determining the sign of each signal value,
continuous checking of the signs of consecutive signal values for the presence of a zero crossing between two consecutive signal values,
determining the number of zero crossings in a defined segment of the consecutive signal values, and
comparing the determined number of zero crossings to a defined threshold value, wherein an undershoot of the threshold value is significant for the presence of a QRS complex in the defined segment of the signal curve.
The core element of the inventive method is the application of a zero crossing count that is based on utilizing the morphology of the QRS complex. The QRS complex in the ECG signal is characterized by a relatively high-amplitude oscillation that markedly guides the signal curve away from the zero line of the electrocardiogram.
The frequency of this short oscillation lies within a range in which other signal components, such as the P and T waves, exert only minor influence and can be removed preferably by pre-filtering, e.g., high-pass or band-pass filtering. After suppression of these low-frequency signal components, signal fluctuations result around the zero line, due to higher-frequency noise, that dominate in the region where no QRS complex occurs. The QRS complex then appears in this signal context as a slow, high-amplitude oscillation of only short duration. The differentiation between a QRS complex and the other signal segments can thus be detected with a frequency measurement that can be described representatively, based on the discussed signal characteristics, by the number of zero crossings per defined evaluated segment. The zero crossing count produces a number that is nearly proportional to the given dominant frequency of the signal.
In lieu of pre-filtering the signal values to eliminate the P and T waves, the QRS complex may, in the inventive method, also be distinguished from the P and T waves by determining the duration or the moment of the significant absence of zero crossings within the ECG signal.
The method of detecting the QRS complex by counting zero crossings has proven robust with regard to noise interference and easy to implement with respect to the computing technology. In this respect it is particularly suitable for implementation in the real time analysis of ECG signal morphologies in cardiac pacemakers.
The previously mentioned high-pass filtering is performed preferably with a lower pass frequency of 18 Hz. In this manner the low-frequency components, such as the P and T waves, as well as a base line drift can be suppressed. Furthermore, the QRS complex thus becomes the signal component with the lowest frequency that dominates the signal during its occurrence.
To increase the signal-noise distance, provision may furthermore be made to square the signal values prior to checking them for zero crossings and prior to determining the number of zero crossings, while maintaining their signs. As a result, smaller signal values are weakened relative to larger signal values, which further improves the detectability of the QRS complex.
The same purpose is served by the preferred method characteristic of the addition of a high-frequency overlay signal b(n) to the high-pass filtered ECG signal that has been squared while maintaining its sign. With this measure the ECG signal is manipulated in such a way that a number of zero crossings is attained outside the QRS complex that is significantly easier to predict. With a properly chosen amplitude, in particular, the ECG signal may be processed such that the number of zero crossings outside the QRS complex is identical to the number of signal values in the respective evaluated segment. This means that a zero crossing takes place between each sampled value, unless a QRS signal complex is detected at that time. This effect is increased if the high pass is additionally replaced by a band pass, preferably with lower and upper pass frequencies of 18 Hz and 27 Hz, respectively. The value of the amplitude of the high-frequency overlay signal is preferably determined adaptively from a flowing determination of the average of the band-pass filtered and squared signal values over a defined averaging period.
In accordance with a further preferred embodiment of the inventive signal evaluation process, the threshold value of the number of zero crossings signifying a QRS complex is variably adjusted as an adaptive threshold of so-called quantiles of the frequency distribution of the number of zero crossings itself. More about this can be found in the description of the embodiment.
Lastly, in the detection of the QRS complex, the time of the occurrence of its R spike, too, is interesting from a cardiological point of view. This instant may be determined by determining the maximum of the band-pass filtered and squared signal values in a search interval around the instant at which the zero crossing count D(n) falls below the threshold value. The group delay of the band-pass filter must be subtracted from the time of the occurrence of the signal maximum to obtain the time of the occurrence of the R spike.
Lastly, an estimated useful signal strength and interfering signal strength is determined from the signal values as a further criterion for the presence of an interfering signal or useful signal, and a detection strength signifying the presence of an interfering signal or useful signal is determined therefrom.
The inventive method will be explained in greater detail below based on an embodiment, with the aid of the appended drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a highly schematic presentation of the signal curve of a QRS complex in an ECG signal,
FIG. 2 shows a structural diagram of the inventive signal evaluation method for detecting QRS complexes in ECG signals, and
FIG. 3 shows typical signal curves as they occur with the application of the inventive signal evaluation method according to FIG. 2 .
DESCRIPTION OF THE PREFERRED EMBODIMENT
As is apparent from FIG. 1, an idealized QRS complex consists of a relatively high-amplitude oscillation that initially guides the ECG signal, in the Q spike, away from the zero line 1 in a negative direction. Afterwards the ECG signal is guided, in the R spike, into the positive range with a steep rise and with a subsequent steep drop back into the negative range while forming the S spike.
In reality the ECG signal is accompanied by a certain level of noisiness, as indicated in FIG. 1 by the dashed signal curve. If this noisy signal is now sampled and converted into discrete signal values in chronological order, the sign of each signal value can be determined and a check can be performed as to whether a zero crossing of the ECG signal though the zero line 1 has taken place between these signal values. Outside the QRS complex a high number of zero crossings occurs in a defined segment N 1 , whereas a much lower number of zero crossings is detected during sampling of a segment N 2 in the QRS complex. The count of the number of zero crossings may thus be used to detect a QRS complex.
The ECG signal is sampled and converted into discrete signal values x(n) in chronological order. The sampling rate may be f=360 Hz, for example, i.e., the ECG signal is converted into a sequence of 360 measuring values per second.
The detailed sequence of the inventive evaluation method will now be explained in more detail based on FIG. 2 . According to that structural diagram, the sampled ECG signal x(n) is subjected, on the input side, to a band-pass filtering that serves to remove all signal components that do not belong to the QRS complex. This includes the P and T waves, as well as high-frequency noise that may originate, for example, from the bioelectrical muscle activity. This furthermore suppresses the base line drift and moves the ECG to the zero line 1 . The applied filter BP is non-recursive, linear-phase and has a band-pass characteristic with the pass frequencies f g1 =18 Hz and F g2 =27 Hz, as well as the limiting cutoff frequencies f g1 =2 Hz and f g2 =50 Hz. The filter order is N=200. The group delay of the band-pass filter BP accordingly corresponds to 100 sampling values and must be taken into consideration when determining the time of the occurrence of the QRS complex. The blocking attenuation of the filter is approximately 80 dB.
The signal values x f (n) attained in this manner are subsequently squared in a squaring step QS according to the following relation while maintaining the signs of the given signal values:
x fq ( n )=sign[ x f ( n )]| x f ( n )| 2
In an adding phase 2 , a high-frequency sequence b(n) with a low amplitude that may be described as follows is subsequently overlaid to the band-pass filtered and squared ECG signal:
b ( n )=(−1)″ K ( n )
wherein K(n)>0. Adding is sequence b(n) changes the number of zero crossings per segment. The upper limit of the number of zero crossings is the number N of the sampling values of the segment. With this sequence b(n) the number of zero crossings is increased to this maximum number in the non-QRS segments, whereas the (lower) number of zero crossings is maintained in the QRS complex. To attain this goal, a suitable value for the coefficients K(n) is adaptively estimated from the signal values X fq (n). The band-pass filtered and squared signals are determined flowingly for this purpose over a defined averaging interval of P sampling values according to the following equation: 〈 | x j q | 〉 ( n ) = 1 / P · ∑ i · 0 P - 1 | x f q ( n - i ) |
wherein P=4·(number of sampling values per second).
Empirically, the following relation results for K(n):
K ( n )=9<| x fq |>( n )
The averaging time essentially determines the adaptation speed of this estimate and both, averaging segments that are too short, as well as averaging segments that are too long may impact the effectiveness of the signal evaluation method. During the occurrence of QRS complexes the adaptation is paused since the sequence b(n) is intended to only influence the zero crossings during the non-QRS segments.
In FIG. 2, the process complex that pertains to the determination of the coefficients K(n) has been marked as AS. The multiplication of the basic function—indicated in FIG. 2 as a kind of “flip flop function” with “+1, −1, +1, −1, . . . ”—with the amplitude K(n) has been indicated in the form of the multiplication step 3 .
The above discussed signal values are now subjected to the actual zero crossing count NDZ. Counting the zero crossings is principally performed per segment according to the following relation: D ( n ) = ∑ i = 0 N - 1 d ( n - i )
with N indicating the segment length. Furthermore, the following applies:
d ( n )=½|sign[ x b ( n )]−sign[ x b ( n −1]|.
If d(n)=1, this means “zero crossing detected”, d(n)=0 means “no zero crossing detected.” In this manner a high number of zero crossings per segment results for high frequencies and accordingly fewer for low frequencies.
From a signal technology point of view, counting the zero crossings essentially corresponds to a low-pass filtering; in practice counting the zero crossings may be implemented with a filter having a square-pulse response, i.e., the filter pulse response a i =1 with i=0 . . . N−1 produces the number of zero crossings D(n). The advantage of this filter results from the implementation with N−1 shift operations, which is favorable from a computing point of view, and feedback without multiplication. The filter function is, in fact, defined as follows: H ( z ) = ∑ i - 0 N - 1 z - 1 = ( 1 - z - ( N - 1 ) ) / ( 1 - z - 1 )
A further advantage of this implementation lies in the fact that the number of zero crossings takes exclusively whole-number values, the range of which is determined by the segment length N. This feature can be advantageously utilized in the subsequent decision phase ES. The filter order N furthermore significantly influences the robustness of the sign evaluation method with respect to noise. Larger filter orders increase the robustness, however, filters that are too long, on the other hand, due to the prolonged averaging interval, may lead to false-negative detection errors (“false negative” means that even though a QRS complex is present in the ECG signal, it was not detected.) In the present embodiment, the filter order N=10 is used.
The threshold value of the number of zero crossings that is significant for the detection of a QRS complex is determined by comparison with an adaptive threshold. The latter is determined from the average of the 0.1 and 0.5 quantiles of the frequency distribution f(m) of D(n). The statistical size “quantile” is used because it has a greater robustness, compared to average and variance, with respect to statistic freak values. In the present case it is very easy to calculate, as the signal values can take only whole-number values between 0≦D(n)≦N. The frequency distribution f(m) with 0≦m≦N is determined adaptively in two steps, namely:
ƒ n • ( m )=(1−λ)ƒ n−1 ( m )
and
ƒ n [D ( n )]=ƒ n • [D ( n )]+λ
wherein a memory factor 0<λ<1 is used. For the numerical example briefly shown at the end of this description, this memory factor was selected as λ=0.01. It is now easy to determine from the frequency distribution the quantiles and from them, in the manner described above, the adaptive threshold. If D(n) is below the threshold, a QRS complex has been detected, otherwise not. In FIG. 2 the process segment of the threshold estimation has been marked with SWS.
In other respects, the band-pass filtered and squared signal x fq (t) is used to determine the exact time of the occurrence of the R spike of a QRS complex. For this purpose the maximum in this signal is searched in a search interval around the starting point of a QRS complex, the occurrence of which is set as the time of the occurrence of the R spike.
Simultaneous with the actual detection of QRS complexes and to determine the time of the occurrence of the R spike, two additional variables are estimated in the evaluation process for the purpose of evaluating the signal, namely the useful signal strength P QRS and the noise signal strength P Noise . One of the two variables is updated with each detected result. When a QRS complex is detected, the estimated useful signal strength is updated, otherwise the estimated interfering signal strength is updated. For this purpose the value |x fq (t)| max is used in a suitable interval around the instant at which the number of zero crossings D(n) falls below the threshold value, with one exponential windows used in each case in the present implementation. This means the following derivation applies for the estimated useful and interfering signal strengths:
P QRS ( i+ 1)=(1−λ QRS )· P QRS ( i )+λ QRS ·|x fq ( t )| max
in case of a QRS complex
P Noise ( i +1)=(1−λ Noise )· P Noise ( i )+λ Noise ·|x fq ( t )| max
in case of noise.
The memory factors λ in the above two equations were selected as follows:
λ QRS =0.5
and
λ Noise =0.01.
Lastly, a detection strength is calculated from the estimated signal strengths according to the following relation, the value of which provides information as to whether an event that would normally be qualified as a QRS complex is indeed a useful signal that should be attributed to a QRS complex for the signal evaluation method. The detection strength is calculated as follows:
DS= (| x fq ( t )| max −P Noise )/( P QRS −P Noise )
In the present example a detected peak is classified as an interfering signal if the detection strength is less than 0.01. In that case the interfering signal strength is updated. Otherwise it is a QRS complex, after which the useful signal strength is updated accordingly.
Lastly, a time window of 75 ms is used in the signal evaluation. If multiple QRS complexes are detected within this time window, only the first complex is evaluated and the other complexes are extracted. This relatively short refractory time was selected to ensure a swift resumption of the normal detection in case of false-positive detections of a QRS complex, and to thus reduce false-negative recognition errors.
The inventive signal evaluation method as described in detail above was tested and validated with the aid of a database with the designation “MIT/BIH Arrhythmia Data Base” that is sold commercially for test purposes. This database contains 48 two-channel ECG signals with a length of approximately 30 minutes each. These ECG signals are ranged into classes, so that the location of the QRS complexes is known.
The signal evaluation method was performed on a personal computer, with a frequency f used as the sampling rate. To evaluate the efficiency of the present method, the so-called sensitivity Se and specificity +P were determined according to the following condition:
Se=TP/ ( TP+FN ) sensitivity
+P=TP/ ( TP+FP ) specificity
wherein the number of correctly detected QRS complexes is included as TP, the number of false-negative detections is included as FN, and that of the false-positive detections is included as FP. A QRS complex was assumed detected correctly if it was detected within a time window of +/−75 ms around the actual location of the time of its occurrence. The results of this simulation example are listed in the appended Table 1. From this table it can be seen that the sensitivity Se and specificity +P were significantly higher than 99% for the large majority of data sets—the so-called “tapes”—and in some instances exactly 100%. Only in very few cases of very noisy signals, such as in tapes No. 105 and 108 were these values lower, however, still high enough for good results to be obtained there as well.
The simulation example is also shown graphically in FIG. 3 by way of example. The signal curve 4 , for example, reflects the actual ECG signal. It clearly shows the R spike 5 , the immediately adjacent Q and S spikes 6 , 7 are only implied.
Also entered is the adaptive threshold 8 for distinguishing between QRS and non-QRS segments. Based thereon, the curve 9 reflects the course of the number of zero crossings of the ECG signal values. It is apparent how, after the occurrence of a QRS complex, the number of zero crossings breaks in with a delay t G that corresponds to the group delay time in the sampling and filtering of the ECG signal. This is reflected in the downward pointing spikes in the curve 9 . Synchronously, the threshold value 8 is adapted after the occurrence of a QRS complex, as is apparent from the saw-tooth shaped curve of the threshold value 8 in FIG. 3 .
TABLE 1
Results of the QRS detection with count of zero crossings on the MIT/BIH
Arrhythmia Data Base
Tape No.
Channel
TP
FN
FP
Se (%)
+P (%)
100
MLII
1901
1
0
99.95
100.00
101
MLII
1522
1
8
99.93
99.48
102
V5
1808
13
13
99.29
99.29
103
MLII
1728
1
0
99.94
100.00
104
V5
1839
18
18
99.03
99.03
105
MLII
2151
4
37
99.81
98.31
106
MLII
1691
5
9
99.71
99.47
107
MLII
1776
8
7
99.55
99.61
108
MLII
1448
32
30
97.84
97.97
109
MLII
2077
22
3
98.95
99.86
111
MLII
1773
3
12
99.83
99.33
112
MLII
2110
1
9
99.95
99.58
113
MLII
1505
1
5
99.93
99.67
114
V5
1604
0
6
100.00
99.63
115
MLII
1636
1
0
99.94
100.00
116
MLII
1997
20
4
99.01
99.80
117
MLII
1283
1
2
99.92
99.84
118
MLII
1916
0
2
100.00
99.90
119
MLII
1661
0
0
100.00
100.00
121
MLII
1538
22
33
98.59
97.90
122
MLII
2053
1
0
99.95
100.00
123
MLII
1269
0
5
100.00
99.61
124
MLII
1365
2
4
99.85
99.71
200
MLII
2165
3
27
99.86
98.77
201
MLII
1520
1
84
99.93
94.76
202
MLII
1870
1
13
99.95
99.31
203
MLII
2437
44
38
98.23
98.46
205
MLII
2195
6
0
99.73
100.00
207
MLII
1586
6
113
99.62
93.35
208
MLII
2419
18
8
99.26
99.67
209
MLII
2518
0
6
100.00
99.76
210
MLII
2200
4
6
99.82
99.73
212
MLII
2284
1
7
99.96
99.69
213
MLII
2672
28
26
98.96
99.04
214
MLII
1876
2
12
99.89
99.36
215
MLII
2794
1
0
99.96
100.00
217
MLII
1843
2
8
99.89
99.57
219
MLII
1773
0
1
100.00
99.94
220
MLII
1693
1
0
99.94
100.00
221
MLII
2004
16
17
99.21
99.16
222
MLII
2116
0
6
100.00
99.72
223
MLII
2199
0
2
100.00
99.91
228
MLII
1701
2
55
99.88
96.87
230
MLII
1859
0
15
100.00
99.20
231
MLII
1278
0
0
100.00
100.00
232
MLII
1485
0
22
100.00
98.54
233
MLII
2550
11
0
99.57
100.00
234
MLII
2289
2
0
99.91
100.00
Total:
90977
306
673
99.66
99.27 | 4y
|
FIELD OF INVENTION
This invention pertains to the field of semiconductors and more particularly, to adhesion of silica to diamond.
BACKGROUND OF INVENTION
Electronic devices based on storage of electrons at an interface are well known. Devices containing interfaces formed by a silica (SiO 2 ) layer disposed on a silicon (Si) substrate are presently in predominant use where the silica layer is provided by controlled oxidation of the silicon substrate. Examples of other substrates in addition to silicon include gallium arsenide (GaAs) and indium phosphide (InP). The charge carrier, i.e., electrons or holes, in such devices are stored at the interfaces and it is desirable to keep leakage current in such devices to a minimum in order to minimize loss of the charge. The electronic devices of silica disposed over a silicon substrate have low leakage current. Unfortunately, the present electronic devices of silica disposed over a diamond substrate have an undesirably high leakage current which drains the charge in such devices over a period of time.
Energy band gap is important especially in optical applications for the electronic devices. The width of the band gap is the lowest energy to which the device is responsive. This means that a device with a large or a wide band gap will be responsive to a limited energy range. Since band gap of diamond is about five times that of silicon, electronic devices with diamond substrates are responsive to a more limited energy range than electronic devices with silicon substrates. Specifically, electronic devices with diamond substrates don't respond to visible light whereas electronic devices with silicon substrate are responsive to visible light.
Diamond has many desirable properties which make it especially suitable for electronic, optical and medical applications. Diamond has an energy band gap of 5.5 ev and it generates a limited number of electrons when bombarded with alpha particles, which is indicative of high radiation resistance. Attempts have been made in the past to make semiconductor electronic devices with a diamond substrate and a thin layer of silica on the diamond substrate. Electronic devices having a diamond substrate with a layer of silica thereon have many desirable attributes including reduced leakage current and reduced response to visible light. However, electronic devices of a diamond substrate with a silica coating thereon have not proven to be feasible because of poor adhesion of the silica coating to the diamond substrate and the weak or fragile coating itself, as evidenced by the fact that the silica coating on the diamond substrate can be easily scratched with a tungsten probe.
OBJECTS OF INVENTION
An object of this invention is an electronic device having a low dark current and a low response to visible light;
Another object of this invention is an electronic device comprising a diamond substrate with a robust silica coating and having a low dark current and low responsiveness to visible light; and
Another object of this invention is to provide a robust coating of silica tenaciously adhering to the diamond surface.
SUMMARY OF INVENTION
These and other objects of this invention are accomplished by removing the non-diamond layer inherently formed on diamond substrates in an article comprising a diamond and a silicon dioxide layer bonded thereto. The non-diamond carbon is removed by electrochemical cleaning. This as-deposited silicon dioxide layer, which is fragile, is annealed at an elevated temperature to strengthen the silica layer and to obtain a tenacious bond between the diamond surface and the silica layer.
DETAILED DESCRIPTION OF INVENTION
The diamond substrate contemplated herein can be polycrystalline or single crystal. Preferably, however, the diamond substrate is single crystal diamond. The dimensions of the diamond substrate can vary in response to what is required. It is contemplated that surface area of the diamond substrate will generally vary from about 1 to about 10,000 mm 2 , but is typically in the approximate range of about 5 to about 1,000 mm 2 . Its thickness is generally in the approximate range of about 5 to about 500 microns and preferably 10 to 100 microns.
As grown diamond substrates inherently have a surface layer of non-diamond carbon. The non-diamond carbon layer typically has a thickness of about 100 to about 10,000 angstroms, and more often in the approximate range of about 200-5000 angstroms. This non-diamond carbon layer is removed during the cleaning operation described hereinafter. The non-diamond carbon layer results from the methods, such as ion implantation, CVD, etc., used to grow and stabilize diamond substrates to graphitization.
The term non-diamond carbon includes amorphous carbon. A layer of non-diamond carbon may contain, in addition to metal carbides, small amounts of other atoms such as nitrogen, argon, helium, iron, and the like.
Silicon oxides (silica) with various impurities can be used as the layer on the diamond substrate. Impurities such as nitrogen, hydroxyl ions, phosphorus and boron, can be present in the oxide of silicon. Silicon dioxide is the preferred layer on the diamond substrate. Silicon dioxide is preferred because it is a familiar material in the silicon device field and because it has a number of beneficial properties such as a large band gap, facile deposition in thin layers on the order of a few hundred angstroms, and a good dielectric strength of about 4×10 6 v/cm. It is also easily made, has good performance, is easy to pattern, and has the largest energy gap (8.8 ev) of any known stable material.
In the device of this invention, the planar dimensions of the silicon dioxide layer may or may not be coextensive with the diamond substrate. The thickness of the layer on the diamond substrate should be in the range of about 0.001-1 micron, preferably 0.04-0.1 micron. If the silica layer is too thick, it will crack and if it is too thin, it will be ineffective for purposes herein.
The cleaning step is the electrochemical removal of non-diamond carbon from the diamond surface on which silica is deposited. Electrochemical removal of the non-diamond carbon from the diamond surface results in a stable, terminated surface.
Electrochemical removal of non-diamond carbon from a diamond surface can be accomplished by immersing the diamond surface covered by the non-diamond carbon in a suitable electrolyte solution between electrodes, impressing a voltage between the electrodes to provide a sufficient electric field in the electrolyte solution to remove the non-diamond carbon, keeping the diamond surface submerged in the electrolyte solution for a sufficient duration to remove the non-diamond carbon, and removing from the electrolyte solution the diamond surface devoid of the non-diamond carbon. The electrodes may be immersed in the electrolyte solution, or positioned outside of it, provided that the diamond surface is subjected to an electric field of sufficient strength to remove the non-diamond carbon. The non-diamond carbon may be completely removed in a single electrochemical step, or over a series of electrochemical steps, each of which removes a portion of the non-diamond carbon.
Although the electric field strength required to obtain the electrochemical removal of non-diamond carbon depends on the particular electrolyte employed, electrode spacing, electrode material and its shape, thickness of the non-diamond carbon to be removed, and other considerations, the electric field in the electrolyte is typically above 1 v\cm, preferably 10 to 100 v/cm. To produce the necessary electric field in the electrolyte for a small separation of the electrodes, the impressed voltage is typically in the approximate range of 5-5000 volts, preferably 10-1000 volts.
The distance between the electrodes should be sufficient to at least accommodate the substrate(s) and obtain the required electric field strength. Electrochemical removal rates or etching rates for the non-diamond carbon are controlled by the electric field between the electrodes, increasing with either applied voltage or a decrease in electrode spacing. Spacing between electrodes is typically in the approximate range of 0.1 cm to 50 cm, preferably 0.5 cm to 20 cm.
When a portion of the diamond surface has been cleaned, i.e., the non-diamond carbon layer has been removed, the cathode can be moved to another location closer to another, uncleaned or lightly cleaned portion. Also, the diamond surface can be moved relative to the electrodes in order to obtain the desired or a more uniform electrochemical cleaning. If the diamond surface is larger than the width of electric field, the entire surface can be treated by moving one or both of the electrodes or moving the surface.
A suitable electrolyte solution has current density of about 1 to 100 ma/cm 2 and an impressed voltage of about 50 to 300 volts. Preferably, the electrolyte solution is a protic high resistivity liquid containing no ions that encourage graphitization of the diamond surface. For example, metal ions such as nickel, encourage graphitization and should not be included in the electrolyte solution. The resistivity of the electrolyte solution should be between about 100 ohm-centimeters and about 10 megaohm-centimeters, preferably in the approximate range of 20 ohm-cm to 5 megaohm-cm.
Especially suitable electrolyte solutions for removal of the non-diamond carbon from a diamond substrate include commercially available distilled water, which contains a small but sufficient concentration of electrolyte impurities; aqueous solutions of acids, such as chromic acid and boric acid; aqueous surfactant solutions; aqueous ammonia; and strong acids, such as sulfuric acid.
The container for the electrolyte should be sufficiently large and deep to allow the submersion of the surface to be etched in the electrolyte. Of course, the material of the container should be inert under operating conditions.
After a diamond is electrochemically cleaned and stabilized, as described above, a layer of silica or silicon dioxide is deposited on the clean diamond surface.
The method of depositing the silica layer is not critical. Typically, the silica layer may be deposited on the diamond substrate as a gas from decomposition of silane in a suitable reactor. The decomposition or reaction of silane with oxygen to produce silica occurs in accordance with the following reaction:
SiH.sub.4 +O.sub.2 →SiO.sub.2 +2H.sub.2
The gaseous silica is deposited on a cleaned diamond substrate which is typically at about 100 to 600° C., preferably 300 to 500° C. When gaseous silica contacts the diamond surface, it accumulates on the diamond surface and converts from a gaseous to a solid state. The thickness of the silica layer can be controlled by controlling the duration of deposition.
The deposition of a silica layer onto a cleaned diamond surface can also be accomplished by other means known to those skilled in the art. For instance, silica can also be deposited on a cleaned diamond surface by sputtering.
The as-deposited silica layer is amorphous, fragile or weak, and does not adhere tenaciously to the cleaned diamond surface. The character of the silica layer and its adhesion to the cleaned diamond surface was determined by scratching it with tungsten probe, which confirmed the fragile nature of the silica layer and its poor adhesion to the cleaned diamond surface.
In order to improve adhesion of the silica layer to the diamond and in order to render the silica layer tough or robust, the fragile silica layer deposited on the cleaned diamond surface is annealed or heat treated in a non-reactive or inert atmosphere at an elevated temperature. Annealing can be carried out in a furnace which has a nitrogen atmosphere or an atmosphere of another non-reactive gas such as argon and helium, by flowing the non-reactive gas through the furnace. Nitrogen is preferred, although any other non-reactive gas would suffice. Nitrogen is capable of forming strong bonds with both silicon and carbon, allowing it to apparently fill oxygen vacancies in the dielectric, terminate dangling carbon bonds at the interface and bridge silicon to carbon. The annealing or heat treating temperature should be high enough and the annealing duration should be long enough to render the silica layer tough and to attain a tenacious bond between the silica layer and the diamond surface on which it is deposited. Typically, the annealing temperature is in the range of about 500-1400° C., more often about 900-1200° C., and the annealing duration is in the range of about 0.1-4 hours, more often about 0.2-2 hours. In the annealing operation, care must be taken to avoid graphitization of the diamond. In an inert atmosphere, the graphitization of diamond commences at about 1200° C. The duration during which diamond is exposed to such elevated temperatures should be minimized to avoid graphitization.
The annealing operation is typically carried out by placing the unannealed electronic device in a furnace and flowing a non-reactive gas through the furnace while gradually ramping the temperature to the final anneal temperature to avoid cracking and/or other thermal dislocation in the diamond or in the silica layer. Cooling to the ambient temperature should also be gradual to avoid cracking.
After annealing, the silica layer is tough and tenaciously adheres to the diamond surface. The scratch hardness of the annealed silica layer is greater than that of tungsten. This scratch hardness may be expressed on any convenient scale, e.g., the Mohs hardness scale or an extension thereof. The toughness or hardness of the silica layer and its adhesion to the diamond substrate can be determined by scratching with a tungsten probe. Annealed silica layer cannnot be manually scratched with a tungsten probe. This test confirms the tenacious bond between the diamond surface and the silica layer and the toughness of the silica layer.
Also, gold wires of about 25 to about 150 microns in outside diameter can be secured to the silica layer and a wire pull test can be conducted to determine the silica's layer toughness and adhesion to the diamond surface. When the pull test is conducted, the gold wires break, indicating the toughness of the silica layer and its strong adhesion to the diamond surface. Annealing improves the interface quality, apparently by irreversibly passivating dangling carbon bonds. Annealing also improves the quality of the silica layer by removing oxygen vacancies and various other traps, and by removing any compensating donors in the diamond.
The final product must not only have strong adhesion between diamond and silica layer thereon and a tough silica layer, it must also have excellent electrical properties. In addition to a low dark current, low current leakage and relative unresponsiveness to visible light, the final product also has better capacity for charge storage than a comparable Si-SiO 2 product. The capacity for charge storage in the electronic devices disclosed herein is reflected in a low leakage current, which is about 10 -9 A/cm 2 .
The low dark current of a diamond-SiO 2 device disclosed herein is equal to or less than about 0.5 pA/cm 2 at room temperature, its leakage current is on the order of 2 nA/cm 2 and its responsiveness to visible light is at least 100 times less than its responsiveness to ultraviolet light. The responsiveness to visible light of a metal insulator semiconductor (MIS) device with a diamond substrate is about 10 -3 times that of an MIS device with a silicon substrate.
For the prior art devices containing diamond/silica interfaces, the leakage current is about 10 -6 A/cm 2 .
The invention having been generally described, the following examples are given as particular embodiments of the invention to demonstrate the practice and advantages thereof. It is understood that the examples are given by way of illustration and are not intended to limit the specification or the claims that follow, in any manner.
EXAMPLE 1
Preparation of Silica Layer on Diamond
This example demonstrates preparation of an electronic device sample composed of a diamond substrate with a coating of silicon dioxide having reduced leakage current and reduced responsiveness to visible light.
The diamond substrate had a surface orientation of (100), was IIb or p-type, was 4 mm by 4 mm in surface area, was 250 microns thick, and had a layer of non-diamond carbon thereon which was a few monolayers thick.
The diamond substrate was electrochemically cleaned by placing the substrate in water for 20 minutes between a pair of spaced platinum electrodes biased at 200 volts. The spacing between the electrodes was 2 cm. This cleaning procedure removed the non-diamond carbon and possibly various other contaminants from the surface of the diamond substrate.
The silicon dioxide layer was then deposited by chemical vapor deposition on the cleaned diamond substrate surface from decomposition of silane in a Pyrox™ reactor in accordance with the following reaction:
SiH.sub.4 +O.sub.2 →SiO.sub.2 +2H.sub.2
The diamond surface apparently catalyzes the reaction of silane with oxygen in the formation of silicon dioxide. The duration of the silicon dioxide deposition was 20 minutes. The diamond substrate during deposition was maintained at 400° C. The layer of silica deposited on the diamond was fragile and adhered weakly to the diamond surface, as observed by scratching the deposited layer with a tungsten probe.
The silica layer deposited on the diamond substrate was annealed in an annealing chamber under an atmosphere of flowing nitrogen. The flow of nitrogen through the annealing chamber was at 10 ft 3 /hr. The temperature in the annealing chamber was ramped from ambient to 1100° C. over a period of 45 minutes, then reduced to 900° C. and held there for 2 hours. The silica layer on the diamond substrate was cooled to about room temperature in about 1 hour by turning off energy to the chamber.
The thickness of the annealed silica layer on the diamond substrate was 400 angstroms. The annealed silica layer disposed on the diamond substrate did not show any evidence of damage when it was scratched with a tungsten probe, indicating a tough, robust layer and a tenacious bond to the diamond substrate.
EXAMPLE 2
Adhesiveness and Toughness of Silica Layer on Diamond
The sample made in Example 1 was then sequentially rinsed in water, acetone, and isopropyl alcohol and patterned with a dot arrangement of 10 dots by 10 dots. Each dot was 150 microns and the spacing between dots was also 150 microns. Gold wires of 25.4 microns (1 mil) in outside diameter were brazed to some of the dots and then were pulled to test the character of the silica layer and the adherence of the silica layer to the diamond surface. In every instance, the wire pulled apart, indicating a robust silica layer and a tenacious bond between the silica layer and the diamond surface.
The leakage current of the sample was about 1.5×10 -14 amp at 10 volts for a 150 micron aluminum dot. This leakage current is much better, i.e., lower, by a factor of greater than 200, compared to leakage current of a comparable prior art diamond-SiO 2 structure. The dark current and the leakage current were comparable to an analogous prior art Si--SiO 2 structure.
It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein. | 4y
|
FIELD OF THE INVENTION
The present invention relates to multimedia database systems and, more particularly, to the operation of similarity search for multimedia objects with several feature attributes. It details algorithms which perform on-the-fly optimizations based on cost predictions whereby reducing overall response time.
BACKGROUND OF THE INVENTION AND DESCRIPTION OF THE PRIOR ART
Objects stored in multimedia databases can be described by a number of feature attributes such as color, texture, or shape. Instead of retrieving exact matching objects, multimedia database queries are targeted at retrieving the k best matching objects along with their “similarity distance”. The best match is to be returned first, the second-best match second, and so on with the similarity distance increasing. For example, when searching for a red image, the image which contains the highest amount of red color should be returned first, followed by an image with the next-highest amount of red. In this example, only one feature attribute is utilized, namely the image color. In typical multimedia applications, several attributes have to be considered simultaneously. For example, when searching for images similar to a given query image, that image's color, texture, and shape attributes might be extracted and used during the search process to improve the quality of the result.
Other application areas of multi-feature queries are (Wolf-Tilo Balke, Ulrich Güntzer, and Werner Kieβling, “Applications of Quick-Combine for Ranked Query Models,” Proceedings of the First DELOS Workshop on Information Seeking, Searching and Querying in Digital Libraries, Zurich, Switzerland, 2000, pp. 41-46):
Feature lists within the SQL/MM standard, Content management in digital libraries, Enterprise information portals, Knowledge management systems, and Multi-classifier combination.
Different attributes are often stored at different locations or indexed by different indexing schemes due to the use of legacy systems or performance considerations. Therefore, an additional layer may be required to combine the search results for each single attribute into an overall search result. For example, query support for color similarity and shape similarity is provided but the user wants to find images that are red AND round. The similarity distance might be defined as the maximum of the similarity distances for color and for shape. An image which is very red but not round will then get a higher distance and consequently a lower rank than a very red and round image. Such a function that combines distances in order to yield a new overall distance, is also called aggregation function.
Since many multimedia applications are highly interactive, it is desirable to allow for an incremental retrieval. For example, if the user requests the best matches for a given image, the first 10-best matches should be returned within seconds. While the user inspects these matches, the system can continue to retrieve the 10 second-best matches in the background and present them to the user on request. It is important to note that a response “within seconds” prohibits an exhaustive search over the whole data repository. Instead of modeling the ranked feature attributes and the ranked results as tables, they are therefore often modeled as “ranked streams” where only the front part of each stream is known.
Similarly, previous work in this area can be categorized into two classes: table-based and incremental (or stream-based). Table-based approaches assume that a complete ranking is given for the feature attributes to be combined. Incremental approaches assume that only the first few rankings are known but more can be requested later.
If the complete rankings of the feature attributes are given as tables, common cost-based optimization techniques (Surajit Chaudhuri, “An Overview of Query Optimization in Relational Systems,” Proceedings of the 17th ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems, 1998, Seattle, Wash., pp. 34-43) can be applied to compute the join of the tables followed by a sorting operation on the combined similarity distances. Even though this approach takes the cost into account, it is not feasible in an interactive setting because the response time is too long.
For that reason, much previous work focused on incremental solutions. Most solutions are based on Fagin's Algorithm (FA) (Ronald Fagin, “Combining Fuzzy Information from Multiple Systems,” Proceedings of the 15th ACM SIGACT-SIGMOD-SIGART Symposium on Principles of Database Systems, 1996, Montreal, Canada, pp. 216-226). In FA, each ranked feature attribute can be seen as an incoming stream. The goal is to generate an outgoing stream of objects whose ranks are computed using a monotonic aggregation function. Accesses to the head of the stream (next best match for this feature) pay a sequential read cost, whereas accesses to any object in the stream (via object ID) pay a random read cost. FA tries to minimize the overall number of object reads as follows: since the aggregation function is assumed to be monotonic, it is enough to read k objects sequentially from each stream (where k is the number of results desired). The monotonicity guarantees that the overall top-k objects are among those read objects. In order to compute the rank of each read object, random accesses are performed to the streams where that object was not yet seen. Note that FA assumes that the sequential and random access costs are constant for all streams and can therefore not adapt to different access costs.
Several improvements of this algorithm were suggested in order to reduce the number of objects to read sequentially from each incoming stream during query processing. Examples include the Threshold Algorithm (TA) (Ronald Fagin, Amnon Lotem, and Moni Naor, “Optimal Aggregation Algorithms for Middleware,” Proceedings of the ACM Symposium on Principles of Database Systems, 2001, pp.102-113), and the Quick-Combine Algorithm (QA) (Ulrich Güntzer, Wolf-Tilo Balke, and Werner Kieβling, “Optimizing Multi-Feature Queries for Image Databases,” Proceedings of the 26th VLDB (Very Large Database) Conference, Cairo, Egypt, 2000, pp. 419-428). Instead of reading k objects from each stream, TA stops reading as soon as k objects were found whose aggregated distance is less than a certain threshold. This threshold is computed by combining the distances of the last sequentially read object of each stream. Note that the threshold increases with each sequential read access since the distances are monotonically increasing and the combination function is monotonic. QA uses a similar idea as TA but tries to reach the termination condition faster. Since the stream whose distance increases most will cause the highest increase in the threshold value, QA tries to read more objects from this stream. It is therefore adaptive with respect to the distance distribution but not with respect to the cost: a stream that can be expected to increase the distance most, may still need to be avoided if its read cost is too high.
Other approaches try to minimize the number of object reads by combining the index structures of each feature attribute into a common indexing scheme (Paolo Ciaccia, Marco Patella, and Pavel Zezula, “Processing Complex Similarity Queries with Distance-based Access Methods,” Proceedings of the 6th International Conference on Extending Database Technology, Valencia, Spain, 1998, pp. 9-23) which is prohibitive in distributed settings.
It is important to note that reducing the overall number of ranked object reads is not necessarily the best way of reducing the overall query response time. As an example, ranking objects according to shape might be much more expensive than color-based ranking. It is therefore preferable to read more color-ranked objects than shape-ranked objects in order to answer the query. A different query plan may access fewer overall objects but result in a higher response time because it causes more shape-ranked object reads.
The only work that takes the access cost for ranked multi-feature queries into account (Surajit Chaudhuri and Luis Gravano, “Optimizing Queries over Multimedia Repositories,” Proceedings of the International Conference on Management of Data, Montreal, Quebec, Canada, 1996, pp. 91-102) is a hybrid between the table-based and the incremental approaches. There, the optimization is performed before query execution and may not lead to a query plan with minimal cost since it is based on Fagin's first algorithm. Furthermore, the work is restricted to a small number of aggregation functions and does not easily extend to incremental query processing. Worse, for certain data distributions, the algorithm does not read enough objects for each feature attribute and can therefore not yield any result. This problem occurs because the query plan is computed statically before the query execution.
The present invention proposes a dynamic query optimization scheme that takes different access costs into account while at the same time allowing for incremental and distributed query processing. “Dynamic” means that the optimization decisions are made while the query is executed rather than in advance. This leads to better educated cost predictions and thereby more efficient query plans.
SUMMARY OF THE INVENTION
The present invention provides an elegant solution for processing multi-feature queries, which considers the differing access costs associated with each feature. Access cost is a critical factor in determining how individual features should be processed in terms of retrieving through sorted or random access, and, hence, in minimizing overall query response time. The present invention operates dynamically during query processing and seeks to minimize the total query cost in terms of number of features retrieved and cost for access. It works by evaluating different combinations of feature access plans (sorted and random access) according to the number of retrieved features and forward access costs, and it selects the lowest cost plan.
According to a first aspect of the invention, there is provided a method for optimally performing a similarity search for a query object. The similarity search use a data stream for each feature attribute, and the steams are sorted in distance order. The method includes the step of determining a query plan using a cost-aware model. The query plan is executed to obtain at least one object using at least one of the data streams. Information related to the similarity search is returned once the distance of the first object obtained is at most equal to an aggregate distance of the highest distances of objects so far obtained from each of the data steams. According to a second aspect of the invention, determining the query plan includes identifying an access sequence. According to a third aspect of the invention, this step of identifying an access sequence includes determining a location on an equi-threshold line with the lowest accumulated estimated cost, and generating the query plan to reach the location on the equi-threshold line.
According to a fourth aspect of the invention, each of data streams has a cost estimator. These cost estimators are used by the cost-aware model. According to a fifth aspect of the invention, each cost estimator used by the cost-aware model includes a sequential cost function and a random cost function. According to a sixth aspect of the invention, some of cost estimators are based on correlation samples. According to a seventh aspect of the invention, some of the cost estimators are based on extrapolation from past costs.
These and other aspects, features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments, which is to be read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graphical illustration of a multi-feature query example involving a color feature and a shape feature as discussed in the present invention;
FIG. 2 is a high level block diagram of an applicable hardware system according to an embodiment of the present invention;
FIG. 3 is a flow diagram of an incremental version of Threshold Algorithm as discussed in the present invention;
FIG. 4 is a graphical interpretation of the Threshold Algorithm as discussed in the present invention;
FIG. 5 is flow diagram for a dynamic optimization algorithm according to an embodiment of the present invention;
FIGS. 6 ( a ) and ( b ) is a flow diagram of the initialization step 500 of FIG. 5 according to an embodiment of the present invention;
FIG. 7 is a flow diagram of a direction estimator according to an embodiment of the present invention;
FIG. 8 is a flow diagram depicting in more detail the procedure in step 702 of FIG. 7 according to an embodiment of the present invention;
FIG. 9 is a flow diagram depicting in more detail the procedure in step 704 of FIG. 7 according to an embodiment of the present invention;
FIG. 10 is a flow diagram of an implementation of steps 504 and 506 of FIG. 5 according to an embodiment of the present invention; and
FIG. 11 is a flow diagram of another implementation of steps 504 and 506 of FIG. 5 according to an embodiment of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
1. Problem Definition
The problem at hand can be formally described as follows.
Given
d lists ds 1 , . . . , ds d of (ID, value)-pairs sorted by increasing value where each list contains the same set of IDs,
an operation inspectNext(i) that returns the pair with the next smallest value in list ds i , and also returns the values of the same ID in all other lists,
a cost function costNext(i) that assigns a cost to inspectNext(i) in the current state of the algorithm, and
a monotonic aggregation function s that maps d values to a new value,
find
the top k pairs (ID 1 , s(v 11 , . . . , v 1d )), . . . , (ID k , s(v k1 , . . . , v kd )) according to their value, where (ID i , v i1 ), . . . , (ID i , v id ) is an element of ds 1 , . . . , ds d , respectively, for all i, by issuing a sequence of operations (inspectNext(i 1 ), . . . , inspectNext(i n )) to the lists
such that
costNext(i 1 )+. . . +costNext(i n ) is minimized.
FIG. 1 illustrates an example for a multi-feature query having different access costs. Given an object ( 100 ) with a certain color and shape, the goal is to retrieve the best matching objects with respect to color and shape from some database. However, in this example, there is no service that allows to query for both color and shape. Instead, there is one service that delivers the objects in the database ranked by shape ( 102 ), and one service that delivers the objects ranked by color ( 104 ). One reason for having two separate mechanisms might be that shape-support was added later and had to be stored using a different index structure.
Note that the ranking is done relative to the query object and therefore is different for each query. A green object ( 110 ) is, for example, ranked third according to shape for this particular query ( 100 ) but it may have a different ranking for a different query. The similarity of an object to the query object is assumed to be returned together with the object as a real value ( 112 ). The smaller the value, the closer the match according to the criterion.
In order to retrieve a stream ( 108 ) of best matches according to color and shape, the values of the objects in both incoming streams ( 102 and 104 ) have to be combined by some monotonic function ( 106 ). In this example, the combining function ( 106 ) is simply the sum of the color and shape values. When combining all the values of identical objects in both streams, the outgoing stream ( 108 ) results, with objects now ranked by the sum of color and shape similarity. Note that this example comprises only five objects. In reality, thousands or millions of objects might occur in each stream and inspecting all of them would not be feasible. It is therefore a goal to obtain the first k objects in the outgoing stream ( 108 ) merely by reading a few objects at the beginning of each incoming stream ( 102 and 104 ). As described in the formal problem definition, each such “sequential access” is coupled with random accesses to each other incoming stream to obtain the values of the identical object in these other streams.
For a more concrete example, assume that the first two objects are requested for the given example. There is a large variety of ways to answer this query. Among them are the following (using the notation from the formal definition):
1. perform 4 “inspectNext(1)”, followed by 2 “inspectNext(2)”, and
2. perform 1 “inspectNext(1)”, followed by 4 “inspectNext(2)”.
The cost for the two query, strategies is therefore
1. 4*costNext(1)+2*costNext(2), and
2. 1*costNext(1)+4*costNext(2), respectively.
Recall that “costNext(i)” has to include the sequential read cost for stream i as well as the random access cost to all other streams. The overall cost for the two query strategies is therefore
1. 4*(sequential(1)+random(2))+2*(sequential(2)+random(1)), and
2. 1*(sequential(1)+random(2))+4*(sequential(2)+random(1)), respectively,
where “sequential(i)” and “random(i)” denotes the sequential and random read cost, respectively. This is a simplification for the ease of readability since in reality, the sequential read cost can also depend on the rank of the next object to retrieve. The present invention will handle these cases as well.
Clearly, the best query strategy depends on the contributing costs. Assume, random(1)=10, random(2)=1, sequential(1)=100, and sequential(2)=5. These numbers could occur in reality since searching by shape is typically more expensive than searching by color. The overall cost for the two strategies then becomes
1. 4*(100+1)+2*(5+10)=434, and
2. 1 * (100+1)+4 * (5+10)=161, respectively.
The second strategy is therefore clearly the more cost efficient one of the two.
This example teaches the importance of taking access costs into account when making decisions about query evaluation plans. Matters become even more severe when the different data sources are distributed over a network or require very long retrieval times. A good query plan can then reduce the execution time from tens of minutes to just seconds. It is also important to note that this decision cannot be made before query execution since the actual costs depend on the query at hand and may not be constant. The present invention therefore discloses the use of a dynamic query optimizer for combining ranked streams. In this invention, the query plan is updated dynamically while objects are read from incoming streams in order to keep the overall cost at a minimum. The invention bases its decision for the future read strategy on past knowledge and future cost predictors. Section 6 describes the dynamic optimization algorithm in detail.
2. Interface
This section describes a general interface for querying and acquiring information about data streams. Since the present invention can be seen as a data stream itself (namely one generated by combining multiple other data streams), the interface described in this section is also a preferred interface of the present invention.
It is assumed that each data stream supplies ways to initialize the stream, query for the next best matches, and estimate the cost of an operation. In the following, each function of the interface is described with its syntax and semantics.
initialize( . . . )
Initializes a data stream. This may include opening files, initializing index structures, and—in the case of a stream comprising multiple other streams—initializing all incoming streams.
initGetNext(q 1 : object, . . . , q d : object [, s: monotonic fct ])
Starts a ranked retrieval from the stream. Since the ranking is computed relative to a query object, as described in section 1, this query object has to be provided as a parameter. If the data source consists of a single stream, only one query object is required (d=1). If the source is the combination of d streams, one query object per stream has to be provided. For example, there may be one object that describes the desired color and one object that describes the desired shape. Note that some or all of the provided d query objects may be identical. In the example in FIG. 1 , one query object ( 100 ) defines both the color and shape of the desired object to retrieve. Additionally, if multiple streams are used, a monotonic combining function s, such as the sum ( 106 ) in FIG. 1 , has to be provided. No assumptions are made about the concrete implementation of the objects or how they are referenced since these decisions depend on the underlying database system.
In order to start a ranked retrieval, this function may for example sort all objects according to their closeness to the query object. In case an index structure is present, this function may initialize the traversal of the index structure. If this stream is combined of multiple streams, this function may call initGetNext(q 1 ), . . . , and initGetNext(q d ) in stream 1, . . . , and stream d, respectively.
hasNext( ): boolean
This function returns true if there are more objects to be retrieved from the stream. If the length of the stream is known, this function simply has to check whether the number of retrieved objects is less than the length of the stream. The same holds for multiple streams since each incoming stream has to have the same number of objects.
getNextK(k: integer): (o 1 : object, . . . , o k : object)
This is the core function of the data stream retrieval interface. The purpose of this function is to return the next k best-matching objects from the stream where o 1 is the best match and o k is the worst match. For example, if 12 objects were already retrieved from the stream, a call of getNextK(3) would retrieve the 13th, 14th, and 15th best-matching objects. The ranking of the objects depends on the query object(s) q 1 , . . . , q d , and the aggregation function s (if multiple streams are used). As can be seen from this example, the retrieval is incremental. Until initGetNext is called again, subsequent getNextK-calls retrieve the next matches based on what was already retrieved. This is desirable for search engines where the user can look through the first few query results on a page and then click on a button to get the next best results presented, and so on until the desired result is found. Note also that the retrieval follows a “pull model”. This means that the next results are delivered only on request. In a multi-stream setting such a request typically triggers requests to the incoming streams.
getDistance(o: object): float
While the last function was a way of accessing a stream sequentially (beginning from the best match, towards the worst match), this function provides random access to a stream. For a given object o, it returns the value, or distance, according to the query object(s) q 1 , . . . , q d , and the aggregation function s (if multiple streams are used).
getMaxDistance( ): float
This function returns an upper bound on the largest possible distance to be returned by getDistance.
seqCostEstimator(from: integer, to: integer, steps: integer): (cost 1 : float, . . . , cost steps : float)
This function returns the estimated costs for performing sequential stream accesses. These costs are defined as the predicted response times (in seconds) for a call of getNextK(k) after initGetNext was called. The value of k varies between from and to at steps equi-distant steps. The costs should include at least disk access and network transfer times (if applicable). The stream may use past performance measurements to estimate these costs. This function is optional.
randCostEstimator( ): float
This function returns the estimated average cost for performing a random stream access. This cost is defined as the predicted response time (in seconds) for a call of getDistance and should include at least disk access and network transfer times (if applicable). This function is optional.
distEstimator(from: integer, to: integer, steps: integer):(dist 1 : float, . . . , dist steps : float)
This function returns the estimated distances encountered during sequential stream accesses. The values returned are the distances that are predicted to be returned by calls of getNextK(k) after initGetNext was called. The value of k varies between from and to at steps equi-distant steps. The stream may use information about past getNextK-calls to estimate these distances. This function is optional.
The next section details a preferred architecture to be used by this invention in order to solve the problem defined in section 1 while being in compliance with the interface defined in section 2.
3. System Architecture
It is to be appreciated that the term “processor” as used herein is intended to include any processing device, such as, for example, one that includes a CPU (central processing unit). The term “memory” as used herein is intended to include memory associated with a processor or CPU, such as, for example, RAM, ROM, a fixed memory device (e.g., hard drive), a removable memory device (e.g., diskette), etc. In addition, the term “input/output devices” or “I/O devices” as used herein is intended to include, for example, one or more input devices, e.g., keyboard, for making queries and/or inputting data to the processing unit, and/or one or more output devices, e.g., CRT display and/or printer, for presenting query results and/or other results associated with the processing unit. It is also to be understood that various elements associated with a processor may be shared by other processors. Accordingly, software components including instructions or code for performing the methodologies of the invention, as described herein, may be stored in one or more of the associated memory devices (e.g., ROM, fixed or removable memory) and, when ready to be utilized, loaded in part or in whole (e.g., into RAM) and executed by a CPU.
In the context of FIG. 2 , an exemplary hardware architecture for processing multi-feature queries formed in accordance with the invention is described. FIG. 2 illustrates an apparatus according to the invention which may be used for performing multi-feature queries with dynamic cost-conscious optimizations and which complies with the interface described in section 2. The apparatus includes a processor ( 202 ) coupled to a memory ( 200 ), and one or more data sources ( 204 ). It is to be appreciated that the processor ( 202 ) controls and/or performs the methodologies (e.g. dynamic query plan computation) associated with the invention. The memory ( 200 ) is used by the processor ( 202 ) in performing such operations, e.g., storing a list of objects returned by the processor in response to a particular query, or storing a data sample for cost estimation. Each data source ( 204 ) is an apparatus capable of delivering multimedia objects ranked by their similarity to a given criterion (e.g. color similarity). No assumptions are made about the inner workings of a data source ( 204 ); it may be implemented using a stand-alone index structure, a full-fledged database system, or it may itself be realized by an apparatus as in FIG. 1 . The only assumption made is that each data source ( 204 ) complies with the interface described in section 2. It should furthermore be noted that the data sources ( 204 ) may originate from the same database or from two or more different databases. The only assumption made is that the set of objects stored in each database is identical (but may be ranked by different feature attributes). Additionally, the data sources ( 204 ) may be located on the same computer or distributed among two or more different computers in a network. In the latter case, additional network communication costs may arise when the processor ( 202 ) exchanges data with a data source ( 204 ). The present invention is especially suited for the latter case since it can adjust dynamically to changes in the access cost.
For an incoming “getNextK”-request, the processor ( 202 ) can access any of the one or more sources ( 204 ) in any order by issuing any of the requests described in section 2. The processor ( 202 ) can furthermore use the memory ( 200 ) to store intermediate and/or final results and auxiliary information, such as data samples or histograms. Once the processor ( 202 ) detects that the top-k results are found, they can be delivered to the requester.
In various exemplary embodiments, software used to implement the methods outlined in the present invention, and the instructions derived therefrom, are all comprised of instructions which, when read and executed by a computer system, causes the computer system to perform the necessary steps to implement and/or use the present invention. Under control of an operating system, the software and the instructions derived therefrom, may be loaded from an appropriate data storage device and into memory of a computer system for use during actual operations.
Those skilled in the art will recognize that the exemplary architecture illustrated in FIG. 2 is not intended to limit the present invention. Those skilled in the art will appreciate that other alternative architectures may be used without departing from the spirit and scope of the present invention.
In the following sections, the methods implemented by the processor ( 202 ) are discussed.
4. Basic Algorithm
Fagin's Threshold Algorithm (TA) (Ronald Fagin, Amnon Lotem, and Moni Naor, “Optimal Aggregation Algorithms for Middleware,” Proceedings of the ACM Symposium on Principles of Database Systems, 2001, pp. 102-113) is one possible algorithm to implement “getNextK”. Even though it is not cost-concious, it is discussed in this section since it will help understand the present invention.
FIG. 3 provides a flow diagram of an incremental version of TA. Before the first “getNextK”-call can be answered, the algorithm is initialized in step 300 . In this step, the incoming streams are initialized by calling “initGetNext” for each of them and a list is initialized that stores the best candidates found so far sorted by their distance value. In the next step ( 302 ), an object o is read from any of the streams using “getNextK(1)” on the selected stream. Let i be the number of the selected stream. In order to obtain the aggregated distance of the read object, the distance of this object in all streams except i is requested via “getDistance(o)”-calls. Now that all distances for o are known, the aggregate distance can be calculated in step 304 . If the distances for o are v 1 , . . . , v d , the aggregate distance is given by s(v 1 , . . . , v d ). Object o is then inserted in the top-list according to its aggregate distance. In step 306 , a threshold value t is computed as follows. Assume, the highest distance read via “getNextK(1)”-calls in stream 1 is h 1 , and the highest distance read in stream 2 is h 2 , and so on. Then t is defined to be s(h 1 , . . . , h d ). This threshold value is used in step 308 in a termination condition: if the aggregate distance of the best object p in the top-list is less than or equal to t, this object p can be removed from the top-list and returned to the caller as the next best match in step 310 . Otherwise, more objects need to be fetched and the algorithm continues with step 302 .
The correctness of the termination condition stems from the fact that the aggregation function is monotonic. The monotonicity of a function is defined as follows:
The function ƒ: d → is monotonic if ∀ν {right arrow over (1)} , ν {right arrow over (2)} ∈ d , and ν {right arrow over (1)} ≧ν {right arrow over (2)} elementwise, then ƒ(ν {right arrow over (1)} )≧ƒ(ν {right arrow over (2)} ).
The present invention makes the same assumption and can therefore employ the same termination condition. Note that this basic algorithm leaves a lot of leeway in step 302 . The best choice of i (the next stream to read) required to minimize the overall execution cost and response time is far from obvious. The present invention teaches a novel and nonobvious way of making this choice based on cost predictions.
Note that in a concrete implementation, only step 300 would be executed for a call of “initGetNext”. A call of “getNextK(1)” would start directly with a check of condition 308 since there may be already objects in the top-list that can be removed and returned. Calls of “getNextK(k)” are assumed to be translated into k calls of “getNextK(1)”. The concrete implementation for each interface function of the present invention can be found in section 6.
5. A Geometrical View of the Basic Algorithm
The execution of the algorithm presented in section 4 can be viewed as a sequence of location changes in a d-dimensional space. FIG. 4 illustrates an example where d=2. The x-axis ( 400 ) represents the distance values ( 402 ) of data stream 1 and the y-axis ( 404 ) represents the distance values ( 406 ) of data stream 2. A location (x,y) in this 2-dimensional space represents the state of the algorithm where the highest value read from stream 1 is x and the highest value read from stream 2 is y. Each sequential read access to data stream 1 therefore causes an update of the x-coordinate and a movement to the right, whereas a sequential read access to stream 2 causes an update of the y-coordinate and an upward movement. The overall read sequence of the algorithm can therefore be viewed as a query execution path ( 416 ) in this 2-dimensional space.
Pairs of values from stream 1 and stream 2 that belong to the same object, are marked as dots ( 408 , 410 , 412 ) in FIG. 4 . Such a pair could be for example the color and shape similarity of an object. Once the x-coordinate (or y-coordinate) of such a pair is read via sequential access in step 302 of TA (shown in FIG. 3 ), the corresponding y-coordinate (or x-coordinate) is also read due to the additional random access in step 302 . Therefore, the values of all red dots to the left of and/or below the current location are known and their aggregate values are kept in the top-list.
By computing the aggregate value of the current location (which is the aggregate score obtained from the current x and y-coordinate), the current threshold value can be obtained. This corresponds to step 306 in FIG. 3 . Thereby, a threshold value can be assigned to each possible location on the x-y-plane. Note that this mapping of (x,y)-locations to threshold values is defined by the monotonic aggregation function s. The values of this function increase with increasing x and/or y-coordinate. The line 414 in FIG. 4 represents an equi-threshold line for the threshold value at the current location of the algorithm. The shape of the equi-threshold lines depends on s.
TA terminates as soon as the first object in the top-list has an aggregate score less than the threshold. This check is performed in step 308 . In the example in FIG. 4 , object 410 fulfills this property since it is to the lower left of the equi-threshold line ( 414 ). It can therefore be returned. Note however that any query execution path ( 416 ) that terminates on a location along the equi-threshold line ( 414 ) will return the same object. Clearly, there are many such paths. And each possible path results in a different query cost. The goal of the present invention is therefore to dynamically generate a query execution path that minimizes this cost.
Similar to the aggregate function, the cost can also be viewed as a function mapping the state of the TA (or the location in the d-dimensional space) onto an accumulated cost value. Also similar to TA, this cost function is monotonic: the more is read from the streams, the higher the accumulated cost. In the example in FIG. 4 , the equi-cost lines ( 418 ) of an examplary cost function are shown. The location on the equi-threshold line ( 414 ) with the lowest accumulated cost is 420 . An objective of the present invention is to estimate this location and to generate a query plan to reach it by using cost predictions.
6. Framework for Dynamic Optimization
A flow diagram for the dynamic optimization algorithm, which is the core of the present invention, is given in FIG. 5 . In step 500 , the same initialization steps as for TA (step 300 ) are performed. Additionally, the cost and distance estimators are initialized. The present invention allows for a variety of estimators. They will be described in section 6.4 in more detail. In step 502 , the algorithm estimates the direction from the current location (or state) of the algorithm to the location (or state) on the equi-threshold line with the lowest accumulated cost. The present invention allows for a variety of heuristics to be used. These heuristics can be based on the cost and/or density estimators and are discussed in section 6.2. In step 504 , the query execution path is computed based on the density estimators. This path describes the sequence of sequential read accesses to each of the streams. Step 504 is described in greater detail in section 6.3. Step 506 executes the query path computed in step 504 . This is accomplished by executing steps 302 through 308 of TA with minor modifications: the value of i in step 302 is now determined by the query path and the condition in step 308 may become true earlier, in case the query path ends before the threshold line is reached. The query path execution is also detailed in section 6.3. Finally, steps 508 and 510 are identical to steps 308 and 310 of TA.
6.1. Initialization
FIGS. 6A and 6B show a flow diagram of the initialization step 500 in FIG. 5 . It can be understood as a refinement of step 500 and therefore as another preferred embodiment of this step. During initialization, each incoming stream i is initialized via an “initGetNext(q i )”-call ( 600 ) where q i denotes the ith query object as defined in section 2.
This is followed by the initialization of the cost and distance estimators. Each stream needs to have a cost estimator. In case a stream does not support the “seqCostEstimator” and “randCostEstimator” functions, corresponding estimators have to be managed by the present invention. This is checked in steps 602 and 606 for each stream. If a sequential cost estimator is required for a stream i, a local estimator is created and initialized in step 604 . Similarly, if a random cost estimator is required for a stream i, a local estimator is created and initialized ( 608 ). In case stream i does not support the “distEstimator”-function ( 610 ), a local estimator is created and initialized ( 612 ). The estimators are discussed in more detail in section 6.4.
If desired by the user and the size of the main memory ( 200 ) is sufficient, a correlation sample can be created ( 614 ). This sample improves the accuracy of the threshold estimation required in step 502 (the details are discussed in section 6.2.1) at the cost of additional random accesses to all streams. If the sample needs to be created, an array “sample” of size h*d is allocated and h (a user-provided value) object IDs are created randomly ( 616 ). Then, h “getDistance”-calls are issued to each stream to obtain the corresponding distances which are stored in the array “sample” ( 618 ). Here, d denotes again the number of streams.
6.2. Direction Estimation
Assume the algorithm is currently in a state where the highest value read from stream 1 is x 1 , the highest value read from stream 2 is x 2 , and so on. As discussed in section 5, this state can be viewed as a location (x 1 , . . . , X d ) in a d-dimensional space. The goal of step 502 is now to estimate the direction from the current location in which the cost function c reaches a minimum ( 420 ) on the threshold boundary B. By “threshold boundary” it is meant the set of points for which the aggregation function s is at least t:
B:={x∈ d :s ( x )≧ t}
where t denotes an estimate on the threshold value for which condition 308 becomes true.
There are different ways of estimating this direction. Each can be seen as a refinement of step 502 and will be discussed in the following. FIG. 7 shows the basic steps of the direction estimator. First, a set of direction vectors is generated and stored in a variable dirCandidates ( 700 ). These vectors can be generated in different ways. Among the preferred embodiments are:
1. generate the d unit vectors,
2. generate g d−1 vectors by representing them in polar coordinates (r, φ 1 , . . . , φ d−1 ) where r is set to 1 and each φ i is chosen between 0 and π/2 in g steps (g is user-defined).
For special cases of c and s, the optimal direction can be computed directly via linear or non-linear optimization. In this case, step 502 is replaced by the corresponding optimization algorithm. The details are however beyond the scope of this invention.
Once the direction vectors are generated, for each vector v, the point q in B closest to x lying on a straight line starting at x and going in direction v is computed ( 702 ). In other words,
q :=arg min{| x−p|:p∈B∩{x +λν:λ≧0}}.
In step 704 , the accumulated cost for reaching q from x is estimated. When the costs for all directions in dirCandidates are computed, the vector with the smallest cost is stored in variable direction ( 706 ). The preferred embodiments of steps 702 and 704 are given next.
6.2.1. Threshold Intersection Estimation
FIG. 8 illustrates a refinement of step 702 and is to be understood as a preferred embodiment of step 702 . Step 800 checks whether a sample was created during initialization ( 500 ). If no sample is available, the variable boundary' is set to infinity ( 802 ). Otherwise, boundary' is set to s(q') ( 806 ) where q' is the location closest to the origin on a line starting from x in direction v such that a rectangle with corners at q' and the origin covers at least ┌kσ┐ points ( 804 ). Or, more formally:
q 1 :=arg min{| p|:p∈{x +λν:λ≧0}Λ|inrect (0, p )|≧┌ k σ┐}
where “inrect(x,y)” denotes a function that returns the set of sample points that fall within the rectangle with corners at x and y. The variable k stores the rank of the next object to be returned by the combining algorithm. Finally, σ stands for the sampling rate used. One way of computing q' efficiently is by using a bisection algorithm since |inrect(0,p)| is monotonically increasing with |p|.
Once boundary' is obtained, the minimum of the smallest distance of the objects in the top-list and boundary' is calculated and stored in the variable boundary ( 808 ). In case the top-list is empty, the smallest distance is assumed to be the maximum possible distance which is s(getMaxDistance 1 , . . . , getMaxDistance d ), or in other words the aggregate distance of the maximum distances of all streams.
With the value of boundary determined, step 810 computes the location q along a line starting from x in direction v where s has this value. Or, more precisely:
q :=arg min{| p|:p∈{x +λν:λ≧0 }Λs ( p )≧boundary}.
One way of computing q efficiently is by using a bisection algorithm since s(p) is monotonically increasing with |p|.
6.2.2. Cost Estimation
The cost for reaching q from the current location x is determined by using the distance and cost estimators. The refinement of step 704 is illustrated in FIG. 9 . First, the required number of sequential reads is determined for each stream in step 900 . This number is obtained by the inverse of the distance estimator. Since the highest value read from stream i needs to change from x i to q i , the overall number of sequential reads issued to stream i needs to change from dist −1 (x i ) to dist −1 (q i ), where dist −1 denotes the inverse of the distance estimator, i.e. it maps a distance to a number of read steps. One way of obtaining the inverse is via bisection since the distance function is monotonic.
Step 900 stores the values of dist −1 (x i ) and dist −1 (q i ) in variables from i and to i , respectively. In step 902 , the cost estimators are used to calculate the difference in cost between reading from, and to i objects. This difference is given as
seq i :=seqCost i (to i )− seqCost i (from i )
and is stored in a variable seq i ( 902 ). Note that this encompasses only the sequential read cost so far. In step 904 , the overall random cost is calculated by summing up the costs for the random accesses to all streams except i. This cost is given as
rand i := ∑ j ≠ i ( to i - from i ) * randCost j ( )
and is stored in a variable rand i ( 904 ). In step 906 , all sequential and random access costs of all streams are summed up and stored in a variable cost(v).
6.3. Query Plan Computation & Execution
This section explains two preferred embodiments of steps 504 and 506 . Common to both embodiments is that they assume that a value radius is given which determines how far the execution algorithm should “walk” along vector v. As soon as |x−p|>radius (where x denotes the last location and p denotes the current location of the algorithm), the query execution stops. It is preferable to choose smaller values for radius at the beginning and larger ones later since the algorithm will become more stable the more past knowledge it has. The present invention does not restrict the heuristics used however.
The first embodiment of steps 504 and 506 is illustrated in FIG. 10 . In step 1001 , the target location q is modified such that it is in distance radius from the current location x. The algorithm then estimates the number of sequential read accesses required to reach q and stores them in a variable reads 1 for each stream i ( 1000 ). This estimate is obtained by using the inverse distance estimator and rounding to the next closest integer ( 1000 ). Step 1002 checks if all variables reads i are 0. If that is the case, the reads, of the stream for which the inverse distance estimator returned the largest value, is set to 1 ( 1004 ). In step 1006 1 the reads are issued to the streams similar to step 302 of TA. However, step 1006 is modified such that i is not picked arbitrarily but from the sequence 1, . . . , 1, 2, . . . , 2, . . . , d, . . . , d, where the number of 1s is given by reads 1 , and the number of 2s by reads 2 , and so on. In addition, step 1006 updates the local density and/or cost estimators after each sequential and random read access. Step 1008 is identical to steps 304 and 306 of TA. Step 1010 is a modified version of step 308 of TA in that it additionally checks whether there are no more reads left in the sequence. If that is true, the query path execution stops; otherwise, it continues with step 1006 .
The second embodiment of steps 504 and 506 is illustrated in FIG. 11 . It interleaves both steps by constantly reevaluating the deviation from the desired path. The desired path is given by the line starting at x and continuing in direction v. In step 1100 , the next expected distance is determined and stored in a variable dist i for each stream i using the distance estimators. Then, the next possible location p(i) is calculated for each direction i ( 1102 ). The next possible location in direction i is defined as the point whose components are identical to the current location p except for the ith component which is set to p+dist i . Step 1104 picks the direction with the smallest expected distance between p(i) and the desired path as the next read direction i. Step 1106 is similar to step 302 of TA. However, step 1106 additionally updates the local density and/or cost estimators after each sequential and random read access. Step 1108 is identical to steps 304 and 306 of TA. Step 1110 is a modified version of step 308 of TA in that it additionally checks whether the new location p has a distance of at least radius from the old location x. If that is true, the query path execution stops; otherwise, it continues with step 1100 .
The first embodiment can be modified in the following way: instead of issuing reads i “getNextK(1)”-requests to stream i, one request “getNextK(reads i )” can be issued to that stream. This modification might be preferable in a networked setting because the number of requests is reduced. However, the algorithm may now “overshoot” the target q leading to unnecessarily transmitted objects.
6.4. Cost and Distance Estimators
This section summarizes the requirements for the cost and distance estimators.
A local estimator for sequential cost maps the sequence number n to the cost for performing the first n sequential read accesses to a stream. When initialized, this estimator should return 0. Furthermore, the mapping from sequence number to cost has to form a monotonically increasing function. Updates are handed to this estimator as (sequence number, cost)-pairs. A preferred embodiment for this estimator is an array of a certain fixed size that keeps track of the last sequential access costs. The prediction can then be performed using some extrapolation method. This is however beyond the scope of this invention.
A local estimator for random cost returns the expected cost for performing a random access to a stream. When initialized, this estimator should return 0. Updates are handed to this estimator as a single cost-value. A preferred embodiment for this estimator is a variable that keeps track of the average random access cost.
A local distance estimator returns the expected distance read from a stream. When initialized, this estimator should return the value “getMaxDistance( )” for its stream. Furthermore, the mapping from sequence number to distance has to form a monotonically increasing function. Updates are handed to this estimator as (sequence number, distance)-pairs. A preferred embodiment for this estimator is an array of a certain fixed size that keeps track of the last distances read. The prediction can then be performed using some extrapolation method. This is however beyond the scope of this invention.
When a sample is available, the local distance estimator should be based on the sample for higher accuracy. In that case, the sample obtained from each stream (step 618 ) is used as control points for an interpolation function. Again, the details of this interpolation are beyond the scope of this invention.
The external estimators provided by the streams can be created by a variety of ways. In the literature, uniformity-based, fractal dimensionality-based, histogram-based, and sampling-based predictors can be found. The present invention does not make any assumptions about their implementation other than the ones listed for the local estimators. Concrete implementations are therefore beyond the scope of this invention.
6.5. Interface Functions
The non-optional interface functions of section 2 are to be realized as follows:
initialize( . . . ) Call “initialize” in all incoming streams.
initGetNext(q 1 :object, . . . , q d : object, s: monotonic fct) Call “initGetNext(q 1 )” in stream 1. Call “initGetNext(q 2 )” in stream 2. . . . Call “initGetNext(q d )” in stream d. Execute step 500 .
hasNext( ) boolean Call “hasNext( )” in stream 1, . . . , d. If at least one returned TRUE or top-list is not empty, return TRUE else return FALSE.
getNextK(k: integer):(o 1 : object, . . . , o k : object) Execute from step 508 until 1st object is returned. Execute from step 508 until 2nd object is returned. Execute from step 508 until kth object is returned. Return these k objects in order.
getDistance(o:object): float Call “getDistance(o)” in stream 1, . . . , d. This yields d distances dist 1 , . . . , dist d . Return s(dist 1 , . . . , dist d ).
getMaxDistance( ): float Call “getMaxDistance( )” in stream 1, . . . , d. This yields d distances dist 1 , . . . , dist d . Return s(dist 1 , . . . , dist d ). | 4y
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BACKGROUND OF THE INVENTION
The invention relates to a device for profiling an electrode roller, with
a tool slide which can be moved approximately radially backwards and forwards in relation to the electrode roller by means of a feed drive, and
at least one profiling tool which is mounted on the tool slide.
SUMMARY OF THE INVENTION
The object of the invention is to create a device of this type which adapts in a particularly simple way to the diameter of the electrode roller, which diameter gradually decreases during the lifetime of the electrode roller.
This object is achieved according to the invention by means of
a feeler slide which carries a feeler which can move parallel to the tool and is biassed towards the electrode roller,
an adjustable limit stop which limits the relative movement of the tool slide in relation to the feeler slide, and which thus limits the depth of feed of the profiling tool into the electrode roller, and
a clamping device with which the tool slide can be stopped as soon as the preset depth of feed of the profiling tool has been reached.
Advantageous further forms of the invention result from the subsidiary claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail below by means of schematic drawings, where:
FIG. 1 is a device for profiling an electrode roller, as seen in a section normal to the axis of the electrode roller,
FIG. 2 is the Section II--II from FIG. 1,
FIG. 3 is an enlarged section from FIG. 1 and
FIG. 4 is the Section IV--IV from FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The device illustrated is associated with an electrode roller 10 of an electrical resistance welding machine which operates with two such electrode rollers, and has the function of cleaning and re-shaping the outer surface of the electrode roller 10 from time to time, which surface becomes worn and soiled with the welding. The second electrode roller, which is not shown in the drawing, may be associated with a device which corresponds exactly to that shown in FIGS. 1 to 4.
The device illustrated has a post 12 which is fastened in the usual way onto or near a bearing and drive housing for the electrode roller 10, not shown in the drawing. Guides 14, which are shown in the drawing as V-guides, are provided on the post 12, and extend parallel to and at a short distance from an axial plane A which contains the axis of the electrode roller 10. A tool slide 16 is guided along the guides 14; a profiling tool 18, which in the example shown is a profile milling cutter, is located on the tool slide 16.
The profile tool 18 is surrounded as far as possible by a housing 20, which has a suction connection 22 for the removal by suction of pieces of chips which are produced during the profiling of the electrode roller 10.
The profiling tool 18 can be driven by a motor 26 via a toothed belt drive 24. The motor 26 is fastened to the tool slide 16 and is preferably a continuously variable speed electric motor.
The tool slide 16 is fed by a feed drive 28; in the example illustrated this is a pneumatic or hydraulic piston-cylinder unit, the stroke of which is long enough to adapt the operating position of the tool slide to the diameter of the electrode roller, which diameter decreases during the life of the electrode roller, without additional mechanical adjustment.
A clamping device 30 is provided, to stop the tool slide 16 in any possible operating position. This is associated with a pneumatic or hydraulic piston-cylinder unit 32 fastened to the post 12, which acts, via a lever 34 mounted on the post 12, on a shaft 36 which is guided in the pillar 12 and can move normal to the direction of movement of the tool slide 16. The shaft 36 has a frictional lining 38, which can be pressed against a clamping plate 40 which is made of hardened steel and fastened to the tool slide 16.
The tool slide 16 has a guide bore 42 parallel to its guides 14, in which a feeler slide 44 is guided and can move. A feeler 46 in the shape of a roller is located at the end of the feeler slide 44 adjacent to the electrode roller. The diameter of the feeler 46 corresponds to the diameter of the milling cutter which forms the profiling tool 18. The feeler slide 44 is in the form of a cylindrical sleeve with an oblong hole 48, in which a peg 50 fastened to the tool slide engages so that the feeler slide 44 cannot rotate around its axis. By this means it is ensured that the axis of rotation of the roller forming the feeler 46 always remains parallel to the axis of the electrode roller 10.
A hydraulic braking device 52, in the form of a cylinder of the usual commercially available type, is incorporated in the feeler slide 44; a connecting-rod 54 projects from the upper end of this braking device remote from the electrode roller 10, as shown in FIG. 1. The end of the connecting-rod is in contact with the head of a bolt 56, which extends through a spacer sleeve 58 and is fastened together with the latter to a adjustment piece 60. The adjustment piece 60 is bell-shaped at its lower region, as shown in FIG. 1, and has a fine external thread 62 which is screwed into a cap 64 fastened to the tool slide 16.
A similarly bell-shaped connecting member 66, which can move axially, is guided in the bell-shaped lower region of the adjustment piece 60. As shown in FIG. 2, this connecting member 66 has a collar 68 projecting inwards at its upper end and a basal flange 70 projecting radially outwards at its lower end. The spacer sleeve 58 likewise has a basal flange 72 which projects radially outwards, which flange is disposed under the collar 68 of the connecting member 66, as shown in FIG. 1, and thus limits the path along which the connecting member 66 can move downwards in relation to the adjustment piece 60.
A spring arrangement 74 is mounted between the adjustment piece 60 and the connecting member 66; in the example illustrated this is formed as a spring washer assembly. The pre-load of the spring arrangement 74 is transmitted to the feeler slide 44 via the basal flange 70 of the connecting member 66.
The highest possible setting of the feeler slide 44 in relation to the tool slide 16 is determined by the setting of the adjustment piece 60, which is screwed into the cap 64 to a greater or lesser extent, and the lower edge of which forms a limit stop 76 for the basal flange 70 of the connecting member 66.
A helical compression spring 78 is disposed inside the bell-shaped end of the connecting member 66, and presses on the feeler slide 44 via the cylinder of the braking device 52, so that the feeler slide 44 always attempts to take up its deepest possible position, as determined by the length and location of the oblong hole 48.
The position which the tool slide 16 takes up in relation to the feeler slide 44 for a given setting of the adjustment piece 60 is monitored by a sensor 80, which is fastened to the feeler slide 44 by means of a rod 82, and which sends out a signal as soon as a shoulder 84 incorporated in the adjustment piece 60 takes up a position corresponding to the desired depth of penetration of the shaping tool 18 into the electrode roller 10. The clamping device 30 is activated by this signal.
In order that the adjustment piece 60 cannot move unintentionally, it has a collar of locking grooves 86 arranged parallel to its axis and arranged at equal angular distances from each other, in which a springloaded ball 88, which is radially guided in the pillar, can seat.
The profiling tool 18 and the feeler 46 are arranged symmetrically with respect to the axial plane A so that each point on the circumference of the electrode roller, which rotates in the direction of the arrow in FIG. 1, is sensed by the feeler 46 before it reaches the profiling tool 18. So that the setting of the feeler 46 is not subject to error due to welding beads or other impurities which can adhere to the outer surface of the electrode roller 10, a scraping tool 90 is disposed in front of the feeler 46, which extends radially to the electrode roller 10 and has a cutting edge formed of a hard metal tip, as in lathe tools of conventional type. The scraping tool 90 is guided radially in the post 12 to be movable towards the electrode roller 10, and can be pressed with a predetermined force against the outer surface of the electrode roller by means of a pneumatic or hydraulic piston-cylinder unit 94.
When the device illustrated is in the off-position, none of its components can touch the electrode roller 10. If the latter has to be re-shaped from time to time, for example after a predetermined number of welding operations, the feed drive 28 is pressurized so that it moves the tool slide 16 radially towards the electrode roller 10, i.e. downwards according to FIG. 1. The rest position of the feeler slide 44 in relation to the tool slide 16 is selected so that the feeler 46 abuts the outer surface of the electrode roller when the tool slide 16 moves, whilst the profiling tool 18 is still at a distance of preferably several millimetres from the electrode roller 10.
The feeler 46 then prevents further movement of the feeler slide 44, so that only the tool slide 16 now moves towards the axis of the electrode roller 10. At the same time the spring 78 is compressed until the basal flange 70 of the connecting member is seated on the feeler slide 44. Up to that point the tool slide 16 moves at high speed. Then the bell-shaped lower end of the adjustment piece 60 moves progressively over the connecting member 66, whereupon the spring arrangement 74 is compressed. The connecting-rod 54 is simultaneously pressed into the braking device 52, and the latter slows down the further movement of the tool slide 16 so that the profiling tool 18, which is driven by the motor 26, is gently pressed into the electrode roller 10. The remaining path which the tool slide 16 can now travel against the resistance of the spring arrangement 74 and the braking device 52 is determined by the distance originally set between the limit stop 76 and the basal flange 70 of the connecting member 66.
The scraping tool 90 is preferably activated by the piston-cylinder unit 94 in such a way that it reaches the outer surface of the electrode roller before the feeler 46, and cleans the surface before the feeler becomes effective. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to lock mechanisms for doors. More particularly, this invention relates to lock mechanisms which utilize cylindrical bored lock sets.
2. Description of the Prior Art
In a typical cylindrical or bored lock system (shown in drawing FIG. 1) the lock cylinder is generally enclosed and protected by the outer grip knob of the lock set. The outer and inner grip knobs are coaxially mounted to spindles which are connected to a mechanism that resists knob rotation when the lock controls are set in the locked position. The spindles interact with a latch retractor, and rotation of the spindles when the lock is unlocked will impart transverse motion to the lock retractor, which in turn retracts the latch bolt of the assembly.
The conventional cylindrical lock mechanism has several disadvantages which limit its usefulness in areas having high security requirements. Initially, since the lock cylinder is contained within the outer doorknob, it is subject to easy manipulation. A vandal simply has to remove the doorknob in order to expose the latch retracting mechanism. This mechanism may then be easily manipulated with a common tool such as a screwdriver. Manipulation of the latch retracting mechanism enables the latch bolt to be retracted. In addition, removal of the lock cylinder and cylinder spindle permits direct manipulation of the latch retractor and withdrawal of the latch bolt.
An additional problem with lock mechanisms of the above described type is that it is usually possible to apply sufficient torque through the outside grip knob to cause failure of a lock tab which prevents rotation of the outside knob when the lock controls are set in the locked position. Upon failure of the lock tab, the outside grip knob may be rotated until retraction of the latch bolt has been accomplished.
Because of the above described security problems with cylindrical bored locks, most high security installations utilize lock mechanisms which incorporate some type of deadbolt arrangement in addition to the normal latch bolt. Although these types of locks provide high security, they are also complex and therefore usually relatively expensive.
One deadbolt arrangement is disclosed in U.S. Pat. No. 3,990,277 assigned to the same assignee as the present invention. This mechanism incorporates an exterior knob which is offset from the interior knob. Such an arrangement permits a mechanism to be used which decouples the exterior knob from the interior knob when the lock is engaged.
In a cylindrical bored lock, a deadbolt is often not employed and it becomes very important to protect the lock cylinder from tampering. It is therefore a primary object of the present invention to provide a cylindrical bored lock assembly which guards the lock cylinder and resists tampering.
It is another object of the present invention to achieve a cylindrical bored lockset which approaches deadbolt systems in terms of security but is much simpler and less expensive than such systems.
SUMMARY OF THE INVENTION
The present invention is directed to the modification of a conventional cylindrical lock mechanism which results in a high security lock. The lock cylinder and interior knob are mounted coaxially, and an outer escutcheon covers the lock cylinder so as to protect it against tampering. The outer doorknob is mounted on the outer escutcheon and is offset from the axis of the lock cylinder and inner doorknob. A first cam is included on the cylinder spindle and a second cam is attached to the mounting spindle of the outer doorknob. A pair of pushrods couple the cams to one another so that when the outer doorknob is rotated, the second cam will also rotate, causing the pushrods to move longitudinally. The pushrods will contact the first cam and cause it to rotate which in turn causes rotation of the cylinder spindle and retraction of the latch bolt. By utilizing such an arrangement, removal of the outer doorknob will not expose the lock cylinder or latch retracting mechanism thus preventing unauthorized entry.
In order to prevent the use of excessive torque from breaking the lock mechanism and allowing retraction of the latch bolt, the pushrods may be designed so that they will fail before the lock mechanism. Thus, security problems associated with both removal of the outside doorknob and the application of excessive torque to the outside doorknob are eliminated.
In an alternate embodiment, instead of designing the pushrods to fail before the lock mechanism, the excessive torque problem may be eliminated by designing the lock mechanism so that when it is locked, the first cam will be longitudinally moved so that it will not be contacted by the pushrods upon turning of the outer knob. By decoupling the pushrods from the first cam, rotation of the outer knob will not result in any movement of the first cam and the latch bolt will therefore remain locked.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is an exploded perspective view of a typical prior art cylindrical bored lock mechanism;
FIG. 2 is a side plan view of the lock mechanism of the present invention shown mounted in a door;
FIG. 3 is a side plan view in section of the lock mechanism of the present invention;
FIG. 4 is a plan view of a portion of the lock mechanism of the present invention taken along line 4--4 of FIG. 3; and
FIG. 5 is a side plan view of an alternate embodiment of the lock mechanism of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a typical prior art cylindrical bored lock and latch mechanism is shown. The mechanism includes an outer knob 10 and an outer escutcheon 12. A lock cylinder 14 is carried within the outer knob 10. A key 16 is insertable into the lock cylinder 14 through an opening in the front of the outer knob 10. Operation of the key 16 will cause rotation of a tail piece 18 of the lock cylinder 14. The tail piece 18 interconnects with a cylinder spindle 19 which interacts with a latch retraction assembly 20. Rotation of the tail piece 18 by means of the key 16 will cause the latch retractor assembly 20 to retract a latch bolt 22. An outer spindle 24 is connected to the outer knob 10 and surrounds the cylinder spindle 19. The outer spindle 24 is interconnected with the latch retractor assembly 20 so that rotation of the outer spindle 24 will also cause the latch bolt 22 to be retracted. A lock control 26 prevents rotation of the outer spindle 24 when it is in a locked position. A cover 28 fits over the latch retractor assembly 20, outer spindle 24 and the lock control 26. An inner knob 30 is supported by an inner escutcheon 32 and is connected to the outer spindle 24. The outer knob 10 is also connected to the outer spindle 24.
In normal operation, when the lock control 26 of FIG. 1 is in an unlocked position, rotation of either the outer knob 10 or inner knob 30 will cause rotation of the outer spindle 24 or inner spindle 27 and therefore retraction of the latch bolt 22. When the lock control 26 is in its locked position, however, rotation of the outer spindle 24 by means of the outer knob 10 is prevented. In this case, the mechanism may be operated only be means of the key 16 or by rotation of inner knob 30. It should be recognized that the mechanism described in FIG. 1 is but one of several variations which may be used. For example, the mechanism may be designed so that when a lock control is in a locked position, the latch bolt 22 may be retracted only by operating the key 16 (i.e., rotation of the inner knob 30 is prevented as well as rotation of the outer knob 10). A detailed description of the precise operation of the lock mechanism of FIG. 1 need not be given here, since it is but one of several different arrangements which are used with conventional cylindrical lock mechanisms. The present invention is directed to a modification of a standard cylindrical lock mechanism, and the mechanism of FIG. 1 is described for illustrative purposes only.
Since the lock cylinder 14 in the mechanism of FIG. 1 is carried within the outer knob 10, removal of the outer knob 10 by the application of external force will expose the cylinder spindle 19. The cylinder spindle 19 may then be manipulated to cause retraction of the latch bolt 22. In addition, the application of excessive torque to the outer knob 10 can result in failure of the lock control 26, which would then permit rotation of the outer spindle 24 and withdrawal of the latch bolt 22. The present invention eliminates these potential hazards.
As shown in FIG. 2, the present invention includes an outer escutcheon 40 which has an integral outer protrusion 42 and supports an outer knob 10' below the protrusion 42. For purposes of clarity, elements shown in FIGS. 2-5 which correspond to elements of FIG. 1 are labeled with a prime. The outer escutcheon 40 is secured to a door 38. A key 16' fits in an opening (not shown) in the front of the outer protrusion 42. Mounted on the opposite side of the door 38 is an inner escutcheon 48 through which passes an inner knob 30'. A lock control button 52 extends from the inner knob 30'. A latch bolt 22' extends outwardly from the edge of the door 38 and is surrounded by a latch face 54. The inner knob 30', latch bolt 22' and key 16' all lie on a common axis 36. The outer knob 10' lies on an axis 39 which is offset with respect to the axis 36.
Referring now to FIG. 3, a lock cylinder assembly 14' is carried within the outer protrusion 42 of the escutcheon 40 in order to resist tampering. The lock cylinder assembly 14' includes a cylinder key core 60 which is exposed though the opening in the outer protrusion 42 and into which the key 16' is inserted. Rotation of the key 16' will cause rotation of a tail piece portion 18' of the lock cylinder assembly 14'. The tail piece 18' is coupled to a cylinder spindle 19', and rotation of the tail piece 18' will cause rotation of the cylinder spindle 19' which in turn causes retraction of a latch retractor 20a' or release of a lock mechanism 26', depending upon the particular design utilized.
Located within the inner escutcheon 48 is a support plate 70 to which is secured a housing 72 by means of screws 74. The housing 72 supports an outer spindle 24'. The cylinder spindle 19' is carried within the outer spindle 24'. An upper cam 78 is secured to the outer spindle 24' by welding or otherwise and rotation of the cam 78 will cause rotation of the outer spindle 24', which in turn will cause retraction of the latch retractor 20a'. When the lock mechanism 26' is locked, rotation of the outer spindle 24' is prevented. The upper cam 78 is actuated by means of a pair of pushrods 80 which extend vertically downward from the cam 78. The pushrods 80 cooperate with a lower cam 82 which is attached to a spindle 84 of the outer grip knob 10'. The cam 82 and knob 10' are held in position by a spindle retainer 86 which fits around the spindle 84.
Referring now to FIG. 4, the operation of the inventive portion of the locking mechanism will be described. A positioning bracket 88 serves to accurately position the pushrods 80 within the outer escutcheon 40, permitting them to move only in the vertical direction. When the outer grip knob 10' is rotated, the lower cam 82 will in turn rotate and will raise one of the pushrods 80. The raised pushrod 80 will contact the upper cam 78, causing it to rotate and in turn rotate the outer spindle 24'. The rotation of the outer spindle 24' will cause retraction of the latch retractor 20a' and the latch bolt 22'. A pair of springs 76 are biased between an extension 40a of the outer escutcheon 40 and an end of the pushrods 80, and serve to return the pushrods 80 to their original position. When the locking mechanism 26' is in a locked position, the outer spindle 24' will be prevented from rotating. This in turn restricts rotation of the outer grip knob 10'.
By modifying the design of a conventional cylindrical lock mechanism in the manner described above so that the lock cylinder and inner knob are located on an axis which is offset from the axis of the outer knob 10', the security of the lock mechanism is greatly increased. Since the lock cylinder 14' is not carried within the outer knob 10', removal of the knob 10' will not expose the lock cylinder 14' to tampering. In addition, the protruding portion 42 of the escutcheon 40 can be reinforced in order to make it more difficult to gain access to the lock cylinder 14'.
Although the above described design is still subject to the potential problem of breaking the lock mechanism 26' by the application of excess torque to the outer knob 10', a feature which also eliminates this problem may be easily incorporated. Simply by designing the pushrods 80 so that they will will fail before the lock mechanism 26' (i.e., by making them structurally weaker than the lock mechanism 26'), the application of excess torque to the outer knob 10' will cause failure of the pushrods 80 and the lock mechanism 26' will remain intact. This may be accomplished, for example, by making the pushrods 80 of plastic or zinc. Although the pushrods 80 will have to be replaced, the latch bolt 22' will remain extended and the door 38 will thus remain locked.
The locking mechanism of the present invention may be further strengthened by the addition of a pair of screws 89 and 90 (FIG. 3) which are used to secure the support plate 70 to the outer escutcheon 40. The only change over a normal lock mounting is that the requirement that two additional holes 92 and 94 be drilled in the door 38. As well as securing the outer escutcheon 40 to the support plate 70, the lower screw 90 also functions to position the bracket 88 within the escutcheon 40.
Referring now to FIG. 5, an alternate means of solving the problem of the application of excess torque to the outer knob 10' is shown. In this embodiment, the locking mechanism 68 is designed so that when it is locked, the outer spindle 24', and therefore the upper cam 78, will be longitudinally moved as shown by arrow 90 so that it will be out of the path of the pushrods 80. When this is done, the rotation of the outer knob 10' will have no effect upon the locking mechanism 26' since it will not contact any portion of it. When the locking mechanism 26' is returned to its unlocked position, the upper cam 78 will be moved back into a position where it will be contacted by the pushrods 80 when the knob 10' is rotated. Also, as shown in FIG. 5, the key core 60 may be covered with a hardened steel cap 61 to resist drilling of pins within the key core 60.
Although it is most convenient to mount the cam and pushrod mechanism between the outer escutcheon 40 and the door 38, the mechanism could be mounted within the door 38 itself. Although this might provide marginally increased security, it would require an additional opening to be formed in the door beyond the standard opening which the preferred embodiment utilizes.
In summary, the present invention is directed to an improved cylindrical lock mechanism which has increased security compared to a normal common axis cylindrical lock and yet is simple enough so that its cost will be significantly less than typical high security deadbolt lock mechanisms. The invention can be easily adapted to operate with various types of cylindrical lock mechanisms as long as they depend upon the rotation of a spindle for their operation. The basic design of the lock provides protection against tampering with the lock cylinder by positioning the lock cylinder away from the outer knob. With slight modifications, the mechanism will also prevent the application of excess torque to the outer knob from releasing the lock mechanism. | 4y
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to apparatus for determining the speed of an endless torque-transmitting member of a continuously variable transmission.
[0003] 2. Description of the Related Art
[0004] Conical pulley transmissions having an endless torque-transmitting means and for providing a continuous change of the transmission ratio are increasingly utilized as automatic transmissions in motor vehicles. FIG. 1 of the drawings is a schematic representation showing the basic structure of such a transmission.
[0005] A continuously variable transmission of the type shown in FIG. 1 includes two conical pulley pairs 4 and 6 . One conical pulley disc 4 1 of conical pulley pair 4 is rigidly connected with a drive shaft 8 that is driven by, for example, an internal combustion engine. The other conical pulley disc 4 2 of conical pulley pair 4 is non-rotatably connected with but is axially moveable relative to drive shaft 8 . One conical pulley disc 6 1 of conical pulley pair 6 is rigidly connected with an output shaft 10 that drives the vehicle. The other conical pulley disc 6 2 of conical pulley pair 6 is non-rotatably connected with but is axially moveable relative to output shaft 10 . An endless torque-transmitting means 12 passes around the two conical pulley pairs 4 and 6 and is in frictional engagement with the opposed two conical surfaces of the respective conical pulley pairs. By means of opposite adjustment of the axial spacing between the two conical pulleys of each conical pulley pair, the rotational speed relationship between the two conical pulley pairs, and therefore the transmission ratio of the transmission, can be changed.
[0006] Pressure chambers 14 and 16 that are connected by way of hydraulic conduits 18 and 20 with a control valve 22 serve, for example, for the adjustment of the transmission ratio by the application to pressure chambers 14 and 16 of pressurized hydraulic fluid pressure, by which the transmission ratio can be controlled. A control unit 23 serves for the actuation of the control valve 22 and includes a microprocessor with associated storage means. Inputs for the control unit are connected, for example, with a selection lever unit that serves for operating the transmission, an accelerator pedal, rotational speed sensors, and the like. The outputs of the control unit are connected, for example, with a clutch, a power output stage of the engine (not shown) and control valve 22 . The construction and function of a continuously variable transmission are known and are therefore not further explained.
[0007] For many applications it is advantageous to know the speed of endless torque-transmitting means 12 , for example in order to precisely establish the contact pressure applied by the conical surfaces of the conical pulleys with which the endless torque-transmitting means is in contact, and which is controllable by the pressure in pressure chambers 14 and 16 . That contact pressure should only be as large as necessary for acceptable frictional engagement or power flow between the endless torque-transmitting means and the conical pulleys, so that the transmission is not unnecessarily stressed and so that no unnecessary hydraulic pumping capacity is utilized.
SUMMARY OF THE INVENTION
[0008] An object of the invention is to provide apparatus having a simple structure and that works reliably to determine the speed of the endless torque-transmitting means of a continuously variable transmission.
[0009] That object is achieved with apparatus for the determination of the speed of the endless torque-transmitting means of a continuously variable transmission, which continuously variable transmission includes two conical pulley pairs rotatably situated on separate axes that are parallel to each other and having two spaced conical discs. The axial spacing of the conical discs can be changed in opposite directions for the purpose of changing the rotational speed relationship of the conical pulley pairs, so that an endless torque-transmitting means that passes around the conical pulley pairs moves independently of the respective transmission ratio and in frictional engagement with the conical surfaces of the conical pulleys. The apparatus includes a sensor that detects the speed of the endless torque-transmitting means in a position whose location relative to the movement path of the endless torque-transmitting means is independent of the rotational speed relationship of the conical pulley pairs.
[0010] The sensor is advantageously guided and brought into contact with a slack strand of the endless torque-transmitting means by a guide bar that is tiltable about an axis that is parallel to the axes of the conical pulley pairs.
[0011] The guide bar is advantageously located on an oil pipe that extends between the conical pulley pairs so that it is displaceable in a direction that is substantially perpendicular to the direction of movement of the endless torque-transmitting means and is stationary in the direction of movement of that element.
[0012] If the endless torque-transmitting means is a plate-link chain, the sensor advantageously detects the moving pins that interconnect individual links, the end faces of which pins are in frictional engagement with the conical surfaces. Preferably, the sensor is a proximity sensor that detects the end faces of the pins.
[0013] In a preferred embodiment of the apparatus in accordance with the invention the sensor is connected to an control unit in which data relative to the plate-link chain are stored, and which determines the speed of the plate-link chain by the number of the detected pins and by the time intervals between successive pins. Advantageously, the number of plate links of the plate-link chain and their lengths are stored in the control unit.
[0014] If the plate-link chain has different spacings between the pins, the control unit stores at least one of the different spacing between the pins and at least a number of equal, successive spacings, and the control unit determines the speed of the plate-link chain after detecting a number of equal, successive spacings.
[0015] The invention can be installed in all types of continuously variable transmissions having continuously variable transmission ratios.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The structure, operation, and advantages of the present invention will become further apparent upon consideration of the following description, taken in conjunction with the accompanying drawings in which:
[0017] [0017]FIG. 1 is a schematic representation of a previously-described, known continuously variable transmission with an associated control unit.
[0018] [0018]FIG. 2 is a cross-sectional view through the middle of a continuously variable transmission, perpendicular to the axes of the shafts;
[0019] [0019]FIG. 3 is a side view of a portion of a plate-link chain; and
[0020] [0020]FIG. 4 is an enlarged, cross-sectional view taken along the line IV-IV of FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] [0021]FIG. 2 shows a cross-sectional view through the middle of a continuously variable transmission, perpendicular to the axes of the shafts 8 and 10 . The slack strand of endless torque-transmitting means 12 is guided by a guide bar 24 which prevents undulations of the slack strand. In the illustrated embodiment, the rotational direction of the pulley pairs 4 and 6 is counterclockwise, and shaft 8 is the drive shaft that is driven by the motor. The continuously variable transmission or its endless torque-transmitting means 12 , which are completely represented by dashed lines, are shown in two different positions. In position A, the spacing between the conical pulleys of conical pulley pair 4 is at a minimum and that between the conical pulleys of conical pulley pair 6 is at a maximum, so that the transmission operates at the highest possible gear ratio. In the other position B, the transmission operates at the smallest possible gear ratio, which means that the radius at which the endless torque-transmitting means travels on the conical pulley pair 6 is at a maximum.
[0022] As is apparent, the movement path of endless torque-transmitting means 12 changes continuously with the transmission ratio change, whereby the straight parts of the movement paths generally do not intersect at an intersection point S as shown, the position of which is fixed and independent of the rotational speed relationship or the transmission ratio (in FIG. 2 only the lower intersection point S is identified).
[0023] Guide bar 24 that guides endless torque-transmitting means 12 between an outer guideway 28 and an inner guideway 26 is carried on a fixed pivot in the form of a pin that is fastened to the transmission housing (not shown) or on an oil pipe 30 . Guide rail 24 includes a U-shaped recess 32 whose opposite sidewalls are approximately perpendicular to the movement direction of the endless torque-transmitting means, or to the longitudinal direction of the guide bar, and is supported in such a way that it follows a change of the movement path of the endless torque-transmitting means 12 by pivoting on the outer surface of oil pipe 30 and by the shifting of the opposed walls of recess 32 relative to the oil pipe outer surface, so that its slack strand is continuously securely guided and is secured against any undulations. Oil pipe 30 has radial openings through which, and through corresponding openings at the bottom of recess 32 , guide bar 24 is supplied with lubricant so that the endless torque-transmitting means is lubricated and is moveable along guide bar 24 with reduced friction.
[0024] Endless torque-transmitting means 12 is advantageously shown in the illustrated embodiment as a known plate-link chain, of which a portion is shown in FIG. 3. Such a plate-link chain is composed of several side-by-side rows of plate links 34 arranged in the movement direction of the plate-link chain, in which links 34 are arranged one behind another in the movement direction of the plate-link chain. The connection of the plate links is effected by pins 36 that pass laterally through the plate-link chain or through inner openings of the plate links, wherein the pins are composed of two rocker members the facing surfaces of which roll against each other when the chain assumes a curved form, and whose oppositely-facing surfaces serve as bearing surfaces for neighboring rows of the links and serve for longitudinally connecting the rows. Outer end faces 38 of pins 36 , or the rocker member pairs, form the surfaces with which the plate-link chain is in a frictional engagement with the conical surfaces of the conical disk pairs.
[0025] A sensor 40 is securely fastened on guide bar 24 so that it detects end faces 38 of pins 36 , or the rocker member pairs, that pass by, for detecting the linear speed of plate-link chain 12 . Because guide bar 24 moves in correspondence with the change of the movement path of the plate-link chain, without moving along the movement direction of the chain, the position of the sensor remains constant relative to the movement path of the plate-link chain and is independent of the transmission ratio, so that the linear speed of the plate-link chain is reliably detected.
[0026] Advantageously, sensor 40 is mounted in the middle region of the guide bar, from which a connection conduit can be passed between the conical pulleys to the outside.
[0027] In FIG. 4, which shows a cross-section taken along line IV-IV of FIG. 2, sensor 40 is mounted on the side of guide bar 24 and extends into the interior thereof, where end faces 38 move along a sensor surface of sensor 40 . Sensor 40 is, for example, an inductively functioning distance sensor, the inductance of which changes from time to time when the end faces move by, so that the time lapse or the number of the passing pins 36 can be detected. It is sufficient for resolution accuracy if the two end faces of a pair of rocker members are not detected individually, but are detected together as end faces of a single pin. If the distance between pins 36 and the time duration of the passing movement of two pins passing sensor 40 are known, the speed of the plate-link chain can be determined.
[0028] In order to determine the speed of a so-called “random pitch” chain whose links have different lengths, so that the spacing between pins 36 varies, an algorithm for the detection of the pattern at which the spacing between pins 36 changes can be stored in an control unit connected with sensor 40 , for example in control unit 23 . For example, the pattern in which long and short links follow one another, or the quantity, is stored in control unit 23 , so that by counting the number of successively following same pin spacings can be determined, whether it is a matter of short or long spacings. It should be understood that at least one more additional pin spacing must be evaluated than actually present equal pin spacings. After identifying whether it is a short or a long pin spacing, the speed of the plate-link chain can in turn be determined by forming a simple ratio from the pin spacing and the time interval in which the pins follow one another.
[0029] According to another evaluation type, as many pins can be counted as are contained in the chain, so that the speed can be determined from the length of the time needed and the chain length.
[0030] It should be understood that the algorithm can be changed in various ways.
[0031] The described structural arrangement can be changed in various ways. Sensor 40 can be cast in an opening in the guide bar, or can be glued. Sensor 40 can work in any suitable physical fashion. Sensor 40 can be fastened on a transmission housing of belt-driven transmissions whose conical surfaces have a form by which the junction S is stationary and independent of the transmission ratio, and the movement of the plate-link chain at point S can be determined through an opening in the guide bar. The data transmission from the sensor to an control unit can occur without contact.
[0032] Guide bar 24 does not necessarily have to guide the endless torque-transmitting means along its inner or outer side, but can, for example, guide it only along its inner side, and it can be urged outward elastically at its bearing.
[0033] In a further changed design, a touching wheel, for example a gear wheel or a friction wheel, can be arranged in such a way that it detects the movement of the endless torque-transmitting means about at the junction S, so that a direct mechanical sensing of the endless torque-transmitting means can take place at the stationary location of its movement path. This is especially advantageous if the endless torque-transmitting means is not formed as a plate-link chain, but is in the form of a band with a substantially level front- or backside. It should be understood that a plate-link chain can also be sensed from the outer or inner side.
[0034] In an advantageous way it is common to all embodiments of the invention that the endless torque-transmitting means is detected by the sensor at one position, the location of which is approximately constant relative to the endless torque-transmitting means and independent of the respective transmission ratio. | 4y
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This is a continuation-in-part application of Ser. No. 467,117 filed Feb. 16, 1983, now U.S. Pat. No. 4,469,679, issued Sept. 4, 1984.
This invention relates to cyclic octapeptides which are vasopressin antagonists. The compounds of this invention are 9-desGly-vasopressin (VSP) antagonists or 9-desGly-1-Pmp-vasopressins. More specifically, the structures of these octapeptides have a β-mercapto-β,β-cycloalkylenepropionic acid and five amino acid units cyclized into a 6-unit ring by means of a sulfur derived from a cysteine unit and a sulfur from the propionic acid unit. The ring also has a distinguishing dipeptide tail, which lacks a glycine unit, attached by means of an amido linkage to the 6-cysteine unit.
BACKGROUND OF THE INVENTION
M. Manning, W. H. Sawyer and coworkers have published a series of publications describing various [1-(β-mercapto-β,β-cyclopentamethylenepropionic acid)-4-valine]-arginine-vasopressin congeners which have antivasopressin activity. Representative of these are EPA No. 61,356, U.S. Pat. No. 4,367,225 and U.S. Pat. No. 4,399,125.
All of the Manning compounds have a tripeptide chain attached at unit 6 and are, or course, nonapeptides. The present compounds are distinguished over these by being octapeptides, by having a des-Gly dipeptide tail attached at unit 6 and by having potent vasopressin antagonist activity.
The potent biological activity of the compounds of the present invention is unexpected in view of the fact that des-glycinamide 9 -vasopressin and des-lysine 8 -desglycinamide 9 -vasopressin [T. Barth et al., Collection Czechoslov. Chem. Commun. 39, 506 (1974)] as well as desglycine 9 -oxytocin [B. Berde et al., Handb. Exp. Pharm 23 860 (1968)] retain little of the activity of their respective parent compounds. In fact, Barth reports that desglycinamide 9 -AVP has CNS activity but practically no antidiuretic or uterotonic activity, Belgian Patent No. 896,509.
Certain of the peptide art designations used in the specification and claims are the following: Cap, β-mercapto-β,β-cycloalkylenepropionic acid; Pmp, β-mercapto-β,β-cyclopentamethylenepropionic acid; Chg, cyclohexylglycine; Abu, α-amino-n-butyric acid; Cha, cyclohexylalanine; Pba, aminophenylbutyric acid, Gln, glutamine; Gly, glycine; Tyr, tyrosine; Phe, phenylalanine; Phe(4'-Alk), lower alkylphenylalanine; Val, valine; Nva, norvaline; Ile, isoleucine; Nle, norleucine; D-aIle, D-allo-isoleucine; Leu, leucine; Ala, alanine; Lys, lysine; Arg, arginine; Asn, asparagine; Met, methionine; Tos, tosylate; HF, hydrogen fluoride; BHA, benzhydrylamine; DIEA, diisopropylethylamine; 4-MeBzl, 4-methylbenzyl; TFA, trifluoroacetic acid; DCC, dicyclohexylcarbodiimide; HBT, 1-hydroxybenzotriazole; ADH, antidiuretic hormone; ACM, acetamidomethyl; DMAP, dimethylaminopyridine.
When the term "vasopressin" is used, in the specification only, it means L-arginine vasopressin (AVP) unless otherwise modified. The AVP derivatives of this invention are preferred. "Alk" represents a lower alkyl of 1-4 carbons which is optionally attached to the nitrogen at Y, to the oxygen substituent of the tyrosine unit when such is present at position 2 or to the phenyl ring of a phenylalanine unit at ring position 3. Such alkyl substituents include methyl, ethyl, n-propyl, isopropyl or butyl.
Therefore, in the description herein and in the claims, the nomenclature common in the art of peptide and vasopressin chemistry is used. When no configuration is noted, the amino acid unit is in the L, or naturally occurring, form.
DESCRIPTION OF THE INVENTION
The desGly 9 compounds of the invention are illustrated by the following structural formula: ##STR1## in which: P is Phe or Phe(4'-Alk);
X is D-Phe, D-Val, D-Nva, D-Leu, D-Ile, D-aIle, D-Pba, D-Nle, D-Cha, D-Abu, D-Met D-Chg, D or L-Tyr or D or L-Tyr(alk);
Y is NH 2 , NHAlk, NHBzl or OH;
W is D-Pro, L-Pro or ΔPro (dehydro-Pro);
A is Val, Ile, Abu, Ala, Gly, Lys, Cha, Nle, Phe, Leu, Chg or Nva;
Z is D-Arg, L-Arg, D-Lys or L-Lys;
n is 0, 1 or 2, or a pharmaceutically acceptable salt, ester prodrug or complex thereof.
A subgeneric group of compounds of this invention comprises compounds of formula I in which X is D-Tyr, D-Cha, D-Phe, D-Ile, D-Leu, D-Val or D-Tyr(Et); P is Phe or Phe(4'-Et), A is as defined above, Y is NH 2 ; W is Pro, Z is Arg and n is 1.
The compounds of formula I in which X is D-Tyr(Et) are particularly active ADH antagonists as are the amide 8 congeners.
Individual compounds of interest are [1-(β-mercapto-β,β-cyclopentamethylenepropionic acid)-2-D-tyrosine-4-valine-8-arginine-9-desglycine]vasopressin, [1-(β-mercapto-β,β-cyclopentamethylenepropionic acid)-2-D-tyrosine-4-valine-8-arginine-9-desglycinamide]vasopressin and, especially, [1-(β-mercapto-β,β-cyclopentamethylenepropionic acid)-2-(O-ethyl-D-tyrosine)-4-valine-8-arginine-9-desglycine]vasopressin.
Also included in this invention are various derivatives of the compounds of formula I such as addition salts, prodrugs in ester or amide form and complexes. The addition salts may be either salts with pharmaceutically acceptable cations such as NH 4 .sup.⊕, Ca.sup.⊕⊕, K.sup.⊕ or Na.sup.⊕ at the terminal acid group (Y=OH) or with a pharmaceutically acceptable salt at a basic center of the peptide (as in the Arg units). The acetate salt forms are especially useful although hydrochloride, hydrobromide and salts with other strong acids are useful. The compounds, also, form inner salts or zwitter ions as when Y is OH. The ester prodrug forms are, for example, lower alkyl esters of the acids of formula I which have from 1-8 carbons in the alkyl radical or aralkyl esters such as various benzyl esters. Other latentiated derivatives of the compounds of formula I will be obvious to those skilled in the art "Complexes" include various solvates such as hydrates or alcoholates or those with supporting resins, such as a Merrifield resin.
The compounds of formula I are prepared by cyclizing a linear octapeptide by means of the two mercapto groups, at the cysteine unit (Cys) at position 6 and at the β-mercapto-β,β-cycloalkylenepropionic acid unit (Cap) at position 1. The cyclization reaction occurs readily in the presence of a mild oxidizing agent capable of oxidizing a mercaptan to a disulfide. The reaction is represented as follows: ##STR2## in which: X, P, A and Y are as defined for formula I, above;
Z is as defined for formula I above or also may be a single bond whenever Y is OH;
W is as defined for formula I above or also may be OH whenever Z and Y are absent; and
Q 1 and Q 2 are, each, hydrogen or a displaceable group.
The intermediates of formula II are new compounds and are a part of this invention. The compounds of formula III in which either or both W and Z are absent are also new compounds useful as intermediates as described below. The latter have VSP antagonist activity at a lower level than that of the octapeptides.
The cyclization reaction of this reaction sequence is most usefully carried out by oxidation. Any oxidizing agent known to the art to be capable of converting a dimercaptan to a disulfide may be used. Exemplary of such agents are an alkali metal ferricyanide, especially potassium or sodium ferricyanide, oxygen, gas, diiodomethane or iodine.
As an example, potassium ferricyanide is added to the dimercaptan of formula II dissolved in a suitable inert solvent, for example, water or aqueous methanol at temperatures of from 0°-40°. Often, oxidation is at a pH of 7-7.5 at ambient temperature in dilute solution gives good yields, 40-50%, of the cyclic compound.
The compounds of formula III which are the Cys(OH) 6 or Pro(OH) 7 compounds are reacted with a dipeptide, a protected (NH 2 )-WZY, or an amino acid, (NH 2 )-Z-Y, respectively, as described hereafter.
The linear mercaptan starting material may or may not have displaceable or protective groups common to the art (Q 1 and Q 2 ) present at the various amino acid units. Such protective groups include benzyl, p-methoxybenzyl, 1-adamantyl, t-butyl, p-nitrobenzyl, trityl, benzylthiomethyl, ethylcarbamoyl or acetamidomethyl. Benzyl, adamantyl or t-butyl are removed by mercuric (halo) acetate salts in aqueous methanol at 0°-80°. The protective group is usually removed before cyclization such as during the hydrogen fluoride splitting of the peptide from the supporting resin. It may, however, be removed either during the cyclization or, in situ, before cyclization.
The S-acetamidomethyl groups are especially useful. For example, S-ACM-Pmp-D-Tyr(Et)-Phe-Val-Asn-S-ACM-Cys-Pro-OBzl was treated with potassium carbonate in aqueous methanol to give the Pro acid linear peptide in 78-84% yield. This was, then, oxidatively cyclized using iodine in aqueous methanol to give the desired Pro(OH) 7 product in 65-70% yield. Alternatively, the protected product was cyclized under the same conditions with initial iodine treatment followed by potassium carbonate removal of the protective ester radical. The Pro 7 acid was, then, condensed with Arg(NH 2 ), using DCC and DMAP in DMF at 0°-20° to give the ##STR3## in 45% yield.
Iodine, therefore, removes the S-protective group, especially the ACM group, and cyclizes the intermediate. Mercuric acetate or lead acetate also remove the ACM group to yield a metal mercaptide. This is converted to the thiol in situ by treatment with hydrogen sulfide and, then, oxidized in a separate step.
The desired cyclic octapeptide of formula I can be conveniently isolated by acidifying the aqueous oxidation mixture, such as using glacial acetic acid, and passing the reaction mixture over an ion-exchange chromatographic column, for example, over a weakly acid, acrylic resin column with acid elution, or by gel filtration over a bead-formed gel prepared by cross-linking dextran with epichlorohydrin.
As an alternative to the cyclization of the linear intermediates of formula II suggested above, the cyclized 6-Cys acids or 7-Pro acids (those of formula I in which either both tail units, W and Z, or only one tail unit, Z, are absent) are condensed with a protected dipeptide, W-Z-Y, or with an amino acid, Z-Y, respectively. The reaction of the Cys acid or the Pro acid with a suitably protected dipeptide or amino acid is carried out using any amide forming reaction common to the peptide art. Usually, substantially equimolar quantities of the starting materials are reacted in the presence of a carbodiimide, such as dicyclohexylcarbodiimide, plus 1-hydroxybenzotriazole or dimethylaminopyridine in an organic solvent at from 0°-35°, preferably, from ice to room temperature. The protective groups are removed by a reaction which will not split the disulfide bond of the hexapeptide ring, for example, mild alkali.
The important intermediates of formula II are conveniently prepared using solid-phase methods of peptide synthesis as discussed in M. Manning et al., J. Med. Chem. 25 46 (1982). A commercial benzhydrylamine support resin (BHR) is used to prepare the end products of formula I in which Y is NH 2 (the des-glycines) and a chloromethyl support resin (CMR) is used to prepare the compounds of formula I in which Y is OH (the des-glycinamides).
The peptide chain of the linear peptides of formula II is built up, stepwise, proceeding from unit 8 working toward unit 1. Each unit is properly protected as known in the peptide art and as described below. Alternatively, various oligopeptides may be built up using liquid or support reactions, then condensed as a last step in the reaction sequence for preparing the dimercapto intermediates.
The preferred sequence of resin supported step reactions is conveniently carried out in a Beckman 990B peptide synthesizer without isolation of each intermediate peptide. The details of the procedure are in the working examples presented hereinafter. Solution or enzyme reaction conditions are applicable here as known to the art.
The various amino acids, which are consecutively added to the resin supported chain are protected as known to the art. For example, the Boc protecting group is used for an amino group especially at the α-position; an optionally substituted benzyl, for the mercapto groups at the Pmp and Cys units; tosyl, for the Arg unit; and an optionally substituted carbobenzoxy(Z) for the Tyr or Lys units. The protective groups should, most conveniently, be those which are easily removed, that is, using acid treatment for the tert.-butyloxycarbonyl group, sodium-liquid ammonia or catalytic hydrogenation for the benzyl or carbobenzoxy groups where the removal reaction conditions are not conducive to reaction at other portions of the peptide such as the disulfide bond.
As other examples of protecting groups, the amino group of an amino acid or oligopeptide is protected conventionally by an acyl group such as formyl, trifluoroacetyl, phthaloyl, p-toluenesulfonyl or o-nitrophenylsulfonyl group; a benzyloxycarbonyl group such as benzyloxycarbonyl, o-bromobenzyloxycarbonyl, p-bromobenzyloxycarbonyl, o- or p-chlorobenzyloxycarbonyl, p-nitrobenzyloxycarbonyl or p-methoxybenzyloxycarbonyl, an aliphatic oxycarbonyl group such as trichloroethyloxycarbonyl, t-amyloxycarbonyl, t-butoxycarbonyl or diisopropylmethoxycarbonyl, or an aralkyloxycarbonyl group such as 2-phenylisopropoxycarbonyl, 2-tolylisopropoxycarbonyl or 2-p-diphenylisopropoxycarbonyl. Amino groups are also protected by forming enamines by reaction with a 1,3-diketone such as benzoylacetone or acetylacetone.
The carboxyl groups can be protected by amide formation, hydrazide formation or esterification. The amide group is substituted, if necessary, with a 3,4-dimethoxybenzyl or bis-(p-methoxyphenyl)-methyl group. The hydrazide group is substituted with a benzyloxycarbonyl, trichloroethyloxycarbonyl, trifluoroacetyl, t-butoxycarbonyl, trityl or 2-p-diphenyl-isopropoxycarbonyl group. The ester group is substituted with an alkanol such as methanol, ethanol, t-butanol or cyanomethylalcohol; an aralkanol such as benzylalcohol, p-bromobenzylalcohol, p-chlorobenzylalcohol, p-methoxybenzylalcohol, p-nitrobenzylalcohol, 2,6-dichlorobenzylalcohol, benzhydrylalcohol, benzoylmethylalcohol, p-bromobenzoylmethylalcohol or p-chlorobenzoylmethylalcohol; a phenol such a 2,4,6-trichlorophenol, 2,4,5-trichlorophenol, pentachlorophenol, p-nitrophenol or 2,4-dinitrophenol; or a thiophenol such as thiophenol or p-nitrothiophenol. The hydroxy group in tyrosine is optionally protected by esterification or etherification. A group protected by esterification is, for example an O-acetyl group; a O-benzoyl group, O-benzyloxycarbonyl or O-ethyloxycarbonyl. A group protected by etherification is, for example, an O-benzyl, O-tetrahydropyranyl or O-t-butyl group.
The amino group in the guanidino group in arginine can be protected by a salt forming, nitro, tosyl, benzyloxycarbonyl or mesitylene-2-sulfonyl group. However, it is not always necessary to protect the guanidino group.
The protected linear peptide intermediate is split from the carrying resin matrix, for example, by using ammonia in an alcoholic solvent, and, then, is treated to remove the protective groups, such as by using sodium-liquid ammonia. This procedure gives the amide derivative of the linear octapeptide.
More conveniently, the two steps are combined by treating the resin supported peptide with anhydrous hydrogen fluoride in the presence of a suitable cation scavenger as known to the art, such as anisole, to give the octapeptide intermediate of formula II, in dimercaptan form, and in good yield.
The compounds of this invention have potent vasopressin antagonist activity. Vasopressin is known to contribute to the anti-diuretic mechanism of action within the kidney. When the action of these compounds antagonizes that of the natural anti-diuretic hormone (ADH), the body excretes water due to an increased permeability of the terminal portions of the renal tubule. We believe the mechanism of action is at the vasopressin receptors (V 2 -receptors) located on the plasma membrane of certain renal epithelial cells. The most notable pharmocodynamic effect of the ADH antagonists of the invention is that of a water diuretic rather than of a natriuretic such as a thiazide.
Any patient suffering from the syndrome of inappropriate antidiuretic hormone secretion (SIADH) or from an undesirable edematous condition is a target for the claimed compounds. Examples of clinical conditions indicated for the compounds of this invention include hypertension, hepatic cirrhosis, congestive heart failure or a component of any traumatic condition resulting from serious injury or disease in which the agonism of naturally occurring vasopressin at the VSP-mediated receptor sites is a contributing factor.
The second group of vasopressin receptor sites are the vascular pressor sites (V 1 -receptors) located within the cardiovascular system itself. For example, Compound 5 of Table I below was tested in the Dyckes protocol (U.S. Pat. No. 4,367,255) for inhibition of vasopressin-induced vasoconstriction in the rat; in vitro (pA 2 8.40) and in vivo (pA 2 7.71). Antagonism at the V 2 receptor sites results in vasodilation with an end result of anti-hypertensive activity. Treatment of dysmenorrhea is another utility for the compounds of this invention when administered intravenously or intranasally.
The compounds of this invention, therefore, are used to treat edema or to expell water in patients in need of such treatment by administering parenterally or by insufflation a nontoxic but effective quantity of the chosen compound, preferably combined with a pharmaceutical carrier. Dosage units of the active ingredient are selected from the range 0.01 to 10 mg/kg, preferably 0.01 to 5 mg/kg, based on a 70 kg patient. The dosage units are applied from 1 to 5 times daily.
The pharmaceutical composition for inducing vasopressin antagonism contains an active ingredient of formula I in the form of a dosage unit as described above dissolved or suspended in a standard liquid carrier. A standard carrier is isotonic saline, contained in an ampoule or a multiple dose vial which is suitable for parenteral injection such as for intravenous, subcutaneous or intramuscular administration. A composition for insufflation is similar but is usually administered in a metered dose applicator or inhaler. Pulverized powder compositions may, also, be used, along with oily preparations, gels, buffers for isotonic preparations, emulsions or aerosols, as standard composition forms.
The compounds of this invention have been demonstrated to have unique antagonistic activity toward the natural antidiuretic hormone (anti-ADH activity), in vitro, in the medullary tissue of hog or human kidney and, in vivo, in the hydropenic rat or the hydropenic monkey. Details of the in vitro protocols are in F. L. Stassen et al., J. of Pharm. Exp. Ther. 233, 50-54 (1982) but the calculations of cyclase activity and binding potential at the receptor site are as follows:
Test Procedure for Assay of Adenylate Cyclase Activity:
In each experiment the amount of 32 P/cAMP formed in the absence of medullary membrane is determined (blank). The blank value is subtracted from all experimental data. The compound is tested for its effect on basal adenylate cyclase activity and/or on vasopressin stimulated activity. Each determination is carried out in triplicate. The Ka value is derived from a Lineweaver-Burke plot. Rel. V max =(V max drug/V max vasopressin)×100. K i =I/[(Ka'/Ka)-1] where I is the concentration of the antagonist, and Ka' and Ka are the concentrations of vasopressin required to give half-maximal activity of adenylate cyclase in the presence and absence of antagonist, respectively. Test Procedure for Binding Assay:
In each experiment, the amount of 3 H-vasopressin bound in the absence and in the presence of an excess of vasopressin (7.5×10 -6 M) is measured in triplicate. These values represent total and non-specific binding, respectively. The K B of a compound is derived from the equation for competitive inhibition: K B =IC 50 /(1+L/K D ), where IC 50 is the concentration required for 50% inhibition of specific 3 H-vasopressin binding, L is the concentration of the ligand, and K D is the dissociation constant of 3 H-vasopressin (K D =3.6×10 -9 M; 1SD=0.4×10 -9 M). This is the average K D value determined on 3 preparations of hog kidney membranes.
Hydropenic Rat Protocol
Food and water are removed from male rats approximately 18 hours prior to testing. Animals are housed 4 per metabolism cage. At 0 hour, the test compound is administered intraperitoneally to the test group and an equivalent volume of vehicle is administered to both control groups (fasted and non-fasted). Urine volume and osmolality are measured every hour for 4 hours. Test values are recorded as ml of urine excreted (cumulative), mEq/rat electrolyte excreted, mg/rat urea excreted, and osmolality in milli-Osmoles/kg H 2 O. A tolerance test is used to determine significance. ED 300 is defined as the dose of compound (μg/kg) required to lower urine osmolality to 300 m-Osmoles/kg. ED 500 is defined as the dose of compound (μg/kg) required to lower urine osmolality to 500 m-Osmoles/kg. The hydropenic monkey protocol is similar.
TABLE I______________________________________ ##STR4## anti-ADH activity in vivo (Rat) in vitro (Pig) ED.sub.300 Ki K.sub.BX Y A (μg/kg)* (nM) (μM)______________________________________1. --D-Tyr GlyNH.sub.2 Val 32 30 0.0822. --D-Tyr NH.sub.2 Val 63 27 0.0653. --D-Tyr OH Val 156 160 0.354. --D-Tyr(Et) GlyNH.sub.2 Val 9.9 5.9 0.0115. --D-Tyr(Et) NH.sub.2 Val 5.8 3.0 0.00786. --D-Tyr(Et) NH.sub.2 Abu 13 7.6 0.018______________________________________ *Estimated dose of peptide delivered ip stat (μg/kg) which results in reduction of U.sub.osm from hydropenic levels to 300 mOsmoles/kg H.sub.2 O.
Table I demonstrates, in the described protocols, the anti-vasopressin activity of selected representative compounds whose octapeptide structures have the desGly dipeptide tail which is characteristic of the compounds of this invention. Presence of substantial antagonistic activity is unexpected because, in the agonist series, the des-Gly-oxytocin has an opposite effect on blood pressure compared with oxytocin itself (See B. Berde at al., loc. cit.) and shortening the linear tail of oxytocin and vasopressin result is known in the art to cause "a striking decrease of the typical biological activities of the substances" (see T. Barth et al., loc. cit.).
Compound 5 of Table I, furthermore, has proven to be a compound of exceptional antagonist activity across the various testing protocols in hog or human tissue in vitro tests as well as in hydropenic rat and monkey tests. Its anti-ADH activity, manifested as the dose required to decrease urine osmolality to 300M Osm/kg water in the conscious hydropenic squirrel monkey test, is ED 300 =8.6 Nmoles/kg (i.p.). That of Compound 4 of Table I is 33.1 Nmoles/kg. The 2-D-Phe analog of the latter compound is 319.0 Nmoles/kg.
The following examples are intended solely to teach the preparation of the compounds of this invention. All temperatures are in degrees Centigrade.
EXAMPLE 1
Solid-Phase Synthesis of Pmp(Bzl)-D-Tyr(Br-Z)-Phe-Val-Asn-Cys(OMe-Bzl)-Pro-Arg(Tos) resin
For the solid-phase synthesis of the titled resin supported peptide, Boc-Arg(Tos) resin (3 mmol/5.4 grams of resin) was used as starting material. The appropriately protected amino acids were coupled sequentially onto the Boc-Arg(Tos) resin, prepared by reacting Boc-Arg(Tos) as the cesium salt with commercial Merrifield resin (Cl-CH 2 resin) as known to the art, by using a manual program as described in the following steps:
1. washed with methylene chloride (3 times, 1 minute).
2. prewashed with 33% trifluoroacetic acid in methylene chloride with 1% indole (1 time, 1 minute).
3. deprotection with 33% trifluoroacetic acid in methylene chloride with 1% indole (20 minutes).
4. washed with methylene chloride (3 times, 1 minute).
5. prewashed with 10% triethylamine in methylene chloride (1 time, 1 minute).
6. neutralization with 10% triethylamine in methylene chloride (10 minutes).
7. washed with methylene chloride (3 times, 1 minute).
8. protected amino acid (10 mmol) in triethylamine in methylene chloride and 0.5M N,N'-dicyclohexylcarbodiimide in methylene chloride (20 ml) were added.
The reaction time was up to two hours.
In the case of the coupling of the Asn moiety, 1-hydroxybenzotriazole (HBT, 10 mmol) was added with Boc-Asn in dry dimethylformamide. Dry dimethylformamide (DMF) was also used as solvent when Pmp(Bzl) was coupled onto the peptide resin, using 4-dimethylaminopyridine (10 mM). Completion of each coupling reaction was monitored by the ninhydrin test. The 4-methoxybenzyl group was used to protect the thiol group of Cys and the 2-bromo-carbobenzoxy group was employed to block the phenolic hydroxyl of D-Tyr.
The resulting protected Pmp(Bzl)-D-Tyr(Br-Z)-Phe-Val-Asn-Cys(OMe-Bzl)-Pro-Arg(Tos)-resin was washed well with methylene chloride and methanol, respectively. After drying in vacuo overnight, 8.4 grams of the titled protected resin intermediate was collected.
Preparation of ##STR5##
Pmp(Bzl)-D-Tyr-(p-bromocarbobenzoxy)-Phe-Val-Asn-Cys(OMe-Bzl)-Pro-Arg(Tos) resin (4 g, ca. 1.5 mmol) was subjected to ammonolysis using saturated ammonia/methanol solution (200 ml) in dry dimethylformamide (50 ml) at room temperature for 48 hours. After evaporation to dryness, the residue was precipitated by ethyl acetate/n-hexane and filtered to give the protected octapeptide amide (1.54 g).
This crude peptide was dissolved in liquid ammonia (250 ml) and treated with sodium/liquid ammonia solution to give Pmp-D-Tyr-Phe-Val-Asn-Cys-Pro-Arg-NH 2 which was, then, oxidized using 0.01M potassium ferricyanide solution in 4 l. of aqueous solution at pH 7-7.5. After the completion of oxidation reaction, the pH of aqueous solution was adjusted to pH 4.5 by adding glacial acetic acid. This solution was passed through a weakly acid acrylic resin (Bio-Rex 70) column (11×2.5 cm, H + form) slowly. The column was eluted with 5% and 50% acetic acid solution, respectively. Crude cyclized ##STR6## was collected from 50% acetic acid solution fractions (860 mg).
______________________________________Purification of ##STR7##______________________________________1. Counter-current distribution: Sample: 860 mg crude, n-BuOH/HOAc/H.sub.2 O (4:1:5) 250 transfers(a) fr. 186-204, 436 mg(b) fr. 182-185 & 205-218, 219 mg2. Partition chromatography: Sample: 250 mg (from 1-a), G-25 fine (2.5 × 55 cm), n-BuOH/HOAc/H.sub.2 O (4:1:5)(a) fr. 32-46 222 mg3. Preparative HPLC: Sample: 40 mg (from 2-a); Alltech C18, 3000 psig. Flow rate: 3.0 ml/min. Buffer A: 0.1% TFA Buffer B: 0.25% TFA/CH.sub.3 CN (4:6) 60% B; isocratic; 235 nm (2.0 AUFS) Injection: 10 mg/0.5 ml. buffer A 17 mg of pure titled compound.4. Ion-exchange Chromatography: Sample: 365 mg (from 1-a & 2-a); CMC; 0.01M NH.sub.4 OAc to 0.1M NH.sub.4 OAc Linear gradient(a) fr. 51-70 93.3 mg(b) fr. 71-89 86.5 mg(c) fr. 91-110 65 mg(d) fr. 111- 121 24.5 mg______________________________________
EXAMPLE 2
Preparation of ##STR8##
Pmp(Bzl)-D-Tyr(Br-Z)-Phe-Val-Asn-Cys(OMe-Bzl)-Pro-Arg(Tos)-Resin (4.2 g, 1.5 mmol) from Example 1, in 4.5 ml distilled anisole, was reacted with anhydrous hydrogen fluoride (40 ml) at 0° for one hour. After treatment as described above and evaporation in vacuo to dryness, the residue was treated with anhydrous ether and filtered off to give 1.33 g crude peptide. The completion of removal of the Bzl group from the Pmp moiety was carried out using the sodium in liquid ammonia reaction as described in Example 1. The resulting unprotected octapeptide was cyclized using 0.01M potassium ferricyanide solution at pH 7-7.5 until color persisted for 30 minutes again as described above in the preparation of the amide.
Desglycinamide octapeptide (600 mg) was collected after acidifying the oxidation solution with acetic acid to pH 4.5 and passing the reaction mixture over a Bio-Rex-70 column with 1 l. of 5% acetic acid as eluent.
______________________________________Purification of ##STR9##______________________________________1. Counter-current distribution: Sample: 600 mg from Bio-rex 70. n-BuOH/HOAc/H.sub.2 O (4:1:5); 200 transfers(a) fr. 150-161 169 mg(b) fr. 133-149 & 162-1632. Preparative HPLC: Sample: 52 mg (from 1-a); Alltech C18 (25 cms 10 mm, 10 micron); Buffer A: 0.1% TFA Buffer B: 0.25% TFA/CH.sub.3 CN (4:6) 60% B, isocratic; 3000 psig; 3.0 ml/min. Injection: 10 mg/0.6 ml in buffer A 235 nm (2.0 AUFS).(a) 24 mg(b) 7.3 mgCombine 2-a and 2-b, repurified on HPLC to give 15 mgpure peptide.3. Partition Chromatography: Sample: 117 mg (from 1-A), G-25 fine (2.5 × 55 cm) n-BuOH/HOAc/H.sub.2 O 4:1:5(a) fr. 32-36 83 mg of pure product______________________________________
EXAMPLE 3
Preparation of ##STR10##
The titled compound was prepared by the solid phase method on benzhydrylamine resin (BHA). Thus, 1.0 g BHA resin (1.13 mmol NH 2 /g resin) was reacted with 1.5 equivalents of Boc-Arg(Tos), 1.5 equivalents of DCC and 3.0 equivalents of HBT which were made up in dimethylformamide to be 0.1M in Boc-Arg(Tos). Deblocking was performed with 50% TFA/methylene chloride and neutralization with 5% DIEA/methylene chloride. The peptide was elongated, stepwise, by coupling, using preformed Boc aminoacyl symmetrical anhydrides in DMF (0.1M). Boc-Asn, Boc-D-Tyr(Et) and Pmp(MBz) were successively coupled using DCC and HBT in DMF. Completeness of coupling was monitored by the qualitative ninhydrin test and recoupling was performed as necessary. The completed Pmp(MBz)-D-Tyr-(Et)-Phe-Val-Asn-Cys(MBz)-Pro-Arg(Tos)-BHA resin was washed with methylene chloride and dried to constant weight, 2.34 g.
The peptide was deblocked and cleaved from the resin by treatment with anhydrous liquid hydrogen fluoride (30 ml) in the presence of anisole (4 ml) at 0° for one hour. After evaporation to dryness under vacuum, the resin was washed with ethyl ether, air dried and, then, extracted with degassed dimethylformamide (3×20 ml) and 20% acetic acid (4×20 ml). The DMF and acid extracts were added to 4 l of water (pH 4.5 with acetic acid). The pH was adjusted to 7.2 with ammonium hydroxide and the solution was titrated with 0.01M potassium ferricyanide under argon with stirring until a yellow color persisted (85 ml). The pH was brought to 4.8 with glacial acetic acid. The mixture was filtered and the filtrate passed over a Bio-Rex 70 column (H.sup.⊕). After washing the column with water (200 ml) the crude peptide was eluted with 300 ml of pyridine/acetic acid/water (30:4:66 v/v). The eluant was evaporated under vacuum at 30°. The residue was dissolved in 100 ml of 0.2N acetic acid, then, lyophilized, yielding 507 mg of the crude titled octapeptide.
______________________________________Purification of ##STR11##______________________________________1. Counter-current distribution: Sample: 607 mg crude, n-BuOH:HOAc:H.sub.2 O, 4:1:5, 240 transfers(a) fr. 154-170 & 190-192 71 mg(b) fr. 171-189 230 mg2. Gel filtration Sample: 123 mg of Sample (b), G-15 (2.5 × 55 cm) using 0.2 N HOAc, 25 ml/hr(a) fr. 46-50 ˜20 mg(b) fr. 51-77 60 mg pure peptide______________________________________
EXAMPLE 4
Preparation of ##STR12##
A mixture of 0.1 mmole of (Pmp 1 -D-Leu 2 -Val 4 -desGlyNH 2 )AVP, prepared as described above but using Boc-D-Leu at position 2, and 0.1 mmole of n-propylamine in 20 ml of DMF was reacted with 23 mg (0.11 mmol) of DCC and 14 mg (0.11 mmol) of HBT at room temperature for 2 hours. The volatiles were evaporated to give an oily product residue. The product was purified as described above using: (1) gel filtration over G-10-Sephadex eluted with 0.2N acetic acid; (2) high pressure liquid chromatography using 0.05% TFA in 39% acetonitrile in water; and, again, (3) gel filtration to give 20 mg of the pure octapeptide of the title.
Amino acid analysis: Asp 0.88, Pro 0.93, Val 1.00, Leu 1.09, Phe 0.88, Arg 1.07. HPLC=95% major peak at 11.33 with 40% aqueous acetonitrile with 0.05M KH 2 PO 4 as buffer. K bind =12.1% inhibition at 10 -5 M.
Using (Pmp 1 -D-Tyr(Et) 2 -Val 4 -desGlyNH 2 )-AVP prepared as in Example 2 above and benzylamine gives ##STR13## Other N-alkylated derivatives are prepared similarly.
EXAMPLE 5
Solid Phase Peptide Synthesis of Pmp(4-MeBzl)-D-Tyr(Et)-Phe-Abu-Asn-Cys(4-MeBzl)-Pro-Arg(Tos)-BHA resin
For the solid phase synthesis of the title resin-supported peptide, Boc-Arg(Tos)BHA resin (1.19 mmol/g of resin) was used as a starting material. It was prepared by reaching Boc-Arg(Tos), 3 mmol, with the benzhydrylamine resin, 1.0 mmol, in dimethylformamide for two hours. The benzhydrylamine resin as the hydrochloride salt was covered with methylene chloride overnight. It was, then, washed with methylene chloride (4×1 min), neutralized with 7% diisopropylethylamine in methylene chloride (2×2 min), then, 6×1 min with methylene chloride alone and, finally, 2×1 min with predried dimethylformamide. The loading of Boc-Arg(Tos) on the resin was carried out twice on the shaker using 1-hydroxybenzotriazole (HBT, 6 mmol) and dicyclohexylcarbodiimide (DCC, 3 mmol). A quantitative ninhydrin test and amino acid analysis were performed routinely after loading to determine the percentage loading on the resin. Loading in this particular run was 62.66%, i.e. 0.74 mmol/g of resin was available. The subsequent amino acid, Boc-Pro, was coupled on the shaker using the following protocol.
(1) Washed with methylene chloride (6 times, 1 min).
(2) Prewashed with 50% TFA in methylene chloride (1 time, 1 min).
(3) Deprotected with 50% TFA in methylene chloride (20 min).
(4) Washed with methylene chloride (6 times, 1 min).
(5) Prewashed with 7% DIEA in methylene chloride (1 time, 1 min).
(6) Neutralized with 7% DIEA in methylene chloride (8 min).
(7) Washed with methylene chloride (6 times, 1 min).
(8) Washed with dimethylformamide (2 times, 1 min).
(9) Added protected amino acid (3 mmol) and HBT, 6 mmol, in DMF, followed by the addition of DCC in methylene chloride, 3 mmol, and coupling for 2 hours.
(10) Washed with dimethylformamide (2 times, 1 min).
(11) Washed with methylene chloride (4 times, 1 min).
(12) Washed with ethanol/methylene chloride 1:1 (2 times, 1 min).
(13) Washed with methylene chloride (4 times, 1 min).
The subsequent amino acids were coupled sequentially using Beckman peptide synthesizer 990-B. The program used for each coupling except BocAsn and Pmp(4-MeBzl) was as follows.
(1) Washed with methylene chloride (3 times, 1 min).
(2) Prewashed with 50% TFA in methylene chloride (1 time, 1 min).
(3) Deprotection with 50% TFA in methylene chloride (30 min).
(4) Washed with methylene chloride (3 times, 1 min).
(5) Prewashed with 7% DIEA in methylene chloride (1 time, 1 min).
(6) Neutralized with 7% DIEA in methylene chloride (1 time, 10 min).
(7) Washed with methylene chloride (3 times, 1 min).
(8) Protected amino acids (3 mmol) in methylene chloride, followed by addition of DCC, 3 mmol, 10 ml of 0.3M in methylene chloride, and coupling for two hours.
(9) Washed with methylene chloride (3 times, 1 min).
(10) Washed with ethanol/methylene chloride, 1:1, (3 times, 1 min).
(11) Washed with methylene chloride (3 times, 1 min).
In case of coupling of Asn moiety, 1-hydroxybenzotriazole (HBT, 6 mmol) was used, 10 ml of 0.6M dimethylformamide. Dry dimethylformamide was also used as solvent when Pmp(4-MeBzl) was coupled onto the peptide resin, using 4-dimethylaminopyridine (3 mmol). Completion of each coupling reaction was monitored by the ninhydrin test. The 4-methylbenzyl (4-MeBzl) group was used to protect the thiol groups of the Cys and pentamethylene mercaptopropionic acid (Pmp) moieties.
Preparation of Pmp-D-Tyr(Et)-Phe-Abu-Asn-Cys-Pro-ArgNH 2
Pmp(4-MeBzl)-D-Tyr(Et)-Phe-Abu-Asn-Cys-(4-MeBzl)-Pro-Arg(Tos)BHA-resin, 1.25 g, (0.37 mmol) in 2 ml of anisole, was reacted with anhydrous hydrogen fluoride (20 ml at 0° for 50 min). After evaporation of HF in vacuo, the residue was washed with anhydrous ether, 4×20 ml, and the crude peptide was extracted with dimethylformamide (50 ml) and 33% acetic acid (50 ml) into 2 liter of degassed water previously adjusted to pH 4.5. The aqueous diluted disulfhydryl octapeptide was cyclized using 0.01M potassium ferricyanide solution at pH 7.2 until the yellow color persisted for 30 minutes (50 ml). The pH was adjusted to 4.5 using glacial acetic acid and the solution was passed through a weakly acid acrylic resin (Bio-Rex-70) column (2.5×12, R.sup.⊕ form), slowly. The column was eluted with pyridine-acetate buffer (30:4:66; pyridine/glacial acetic acid/water). The pyridine acetate solution was removed by distillation in vacuo. The residue was lyophilized from 10% acetic acid to give 300 mg (76%) of crude titled peptide.
______________________________________Purification of ##STR14##______________________________________1. Counter-current distribution:Sample: 300 mg, n-BuOH/HOAc/H.sub.2 O, 4:1:5, 240 transfers.(a) fr. 176-186, 99.6 mg of pure peptide(b) fr. 170-175 and 187-210, 117.24 mgYield of purified material, 216.84 mg (55%)2. Molecular Formula: C.sub.50 H.sub.72 N.sub.12 O.sub.10 S.sub.2 Molecular Weight: 1064.53 Amino Acid Analysis: Asp (1.00), Abu + Cys (1.70), Tyr (0.64), Phe (0.98), Arg (0.91) Peptide Content: 68.06-91.52% from amino acid analysis 87.33% from nitrogen analysis3. Chromatography Data: Solvent R.sub.fTLC n-BuOH/HOAc/H.sub.2 O/EtOAc 0.56 (1:1:1:1) n-BuOH/HOAc/H.sub.2 O/ 0.42 (4:1:5) UpperHPLC C.sub.18 -column k'Isocratic H.sub.2 O/CH.sub.3 CN/TFA, 3 (60:40:0.25) 0.05 MKH.sub.2 PO.sub.4 : 7.33 acetonitrile (60:40)Gradient H.sub.2 O/CH.sub.3 CN/TFA, 8.82 80:20:0.25 to 50:50:0.25Fast Atom Bombardment (FAB): m/z 1065 (M + H).sup.+ ; 1063 (M - H).sup.-______________________________________
EXAMPLE 6
Solid Phase Peptide Synthesis of Pmp-(4-MeBzl)-D-Tyr(Et)-Phe-Ala-Asn-Cys-4-MeBzl)-Pro-Arg(Tos)-BHA resin
The tetrapeptide supported resin, Boc-Asn-Cys(4-MeBzl)-Pro-Arg(Tos)-BHA, 0.72 g (0.36 mmol), was synthesized on Beckman 990-B peptide synthesizer, starting from the Boc-Arg(Tos) benzhydrylamine resin (0.72 mmol/g) using a protocol like that of Example 5. The subsequent amino acids were coupled sequentially on the shaker using HBT and DCC for 2 hours in a similar fashion. After coupling of the last residue, i.e, Pmp(4-MeBzl), the resin containing peptide was washed as usual, dried to give 0.88 g of the titled intermediate.
Preparation of ##STR15##
Pmp(4-MeBzl)-D-Tyr(Et)-Phe-Ala-Asn-Cys(4-MeBzl)-Pro-Arg(Tos)-BHA-resin, in 2 ml of anisole, was reacted with anhydrous HF, 20 ml, at 0° for 50 minutes. The work up was done as usual and the uptake of K 3 Fe(CN) 6 was 45 ml to give 230 mg (60.8%) of crude titled peptide.
______________________________________Purification of ##STR16##______________________________________1. Counter-current distribution:Sample: 230 mg, n-BuOH/HOAc/H.sub.2 O, 4:1:5, 240 transfers(a) fr. 160-178, 105.2 mg pure product(b) fr. 179-190 and 150-159, 49.5 mgYield of purified material, 154.7 mg (41%).2. Molecular Formula: C.sub.49 H.sub.70 N.sub.70 O.sub.10 S.sub.2 Molecular Weight: 1050.449 Amino Acid Analysis: Asp (1.00), Pro (1.03), Ala (0.94), Cys (0.46), Tyr (0.65), Phe (0.91), Arg (0.92). Peptide Content: 59.18-81.77% from two analyses.3. Chromatography Data: Solvent R.sub.fTLC mBuOH/HOAc/H.sub.2 O/EtOAc 0.64 (1:1:1:1)HPLC C.sub.18 -column k'Isocratic H.sub.2 O/CH.sub.3 CN/TFA, 2.18 60:40:0.1Gradient H.sub.2 O/CH.sub.3 CN/TFA, 6.47 60:40:0.1 to 50:50:0.1Fast Atom Bombardment (FAB): m/z 1051 (M + H).sup.+ ; 1049 (M - H).sup.-______________________________________
EXAMPLE 7
Solid Phase Peptide Synthesis of Pmp(4-MeBzl)-D-Tyr(Et)-Phe(4'-Et)-Val-Asn-Cys-(4-MeBzl)-Pro-Arg(Tos)-BHA-resin
The titled resin-supported peptide was prepared from BOC-Arg(Tos) BHA resin (0.4 mmol/g) on a shaker using a protocol used before i.e. deprotection-coupling using HBT and DCC for 2 hours, up to Boc-Val-Asn-Cys-(4-MeBzl)-Pro-Arg(Tos)-BHA resin. The next two amino acid residues were coupled using the Beckman peptide synthesizer 990-B. The Pmp(4-MeBzl) was coupled manually using DMAP-DCC overnight. The resin-containing peptide was washed and dried as usual to give 2.00 g of the titled intermediate.
Preparation of ##STR17##
Pmp-(4-MeBzl)-D-Tyr(Et)-Phe(4-Et)-Val-Asn-Cys-4-MeBzl)-Pro-Arg(Tos)-BHA resin, in 3 ml of anisole was reacted with 30 ml of anhydrous hydrogen fluoride at 0° for an hour. The work up was done as described above, with 38 ml of K 3 Fe(CN) 6 taken up. About 50 mg of crude peptide was obtained from the Bio-Rex column and 139 mg was precipitated out of solution, total yield 189 mg (42.7%) of titled peptide.
______________________________________Purification:______________________________________1. Partition column chromatography, Sephadex, G-25:Sample: 50 mg, n-BuOH/HOAc/H.sub.2 O, 4:1:5,(a) fr. A, 23.86 mg(b) fr. B, 18.5 mgPreparative HPLC Sample: 43 mg (From 1, Fr. a + Fr. b), Altex ODS, 10 mm × 25 cm, 5μ, flow rate 4 ml/min., water/acetonitrile/TFA (50:50:0.25), isocratic, 229 nm (2.0 AUFS), injection 2.0 mg/300 μl and 4.0 mg/420 ml to give 30.0 mg of pure peptide.2. Physical Data: Molecular Formula: C.sub.53 H.sub.78 N.sub.12 O.sub.10 S.sub.2 Molecular Weight: 1106.47 Amino Acid Analysis: Asp (1.00), Pro (0.78-0.84), Cys (0.45), Val (1.02), Tyr (0.63), Phe(p-Et) (1.50), Arg (1.00-0.96) Peptide Content: 73.3-89.6%3. Chromatography Data: Solvent R.sub.fTLC nBuOH/HOAc/H.sub.2 O/EtOAc, 0.70 1:1:1:1 nBuOH/HOAc/H.sub.2 O, 0.299 4:1:5 UpperHPLC C.sub.18 Column k'Isocratic H.sub.2 O/CH.sub.3 CH/TFA, 4.43 55:45:0.1Gradient H.sub.2 O/CH.sub.3 CN/TFA, 8.7 60:40:0.1 to 50:50:0.1FAB m/z 1107 (M + H).sup.+ ; 1105 (M - H).sup.-______________________________________
EXAMPLE 8
Synthesis of Boc-Asn-Cys(4-MeBzl)-Pro-Arg(Tos)MBHA resin
One millimole of Boc-Asn-Cys(4-MeBzl)-Pro-Arg-(Tos)-BHA resin was prepared using 1 mmole of Boc-Arg(Tos)-4-methylbenzhydrylamine (MBHA) resin as starting material by coupling sequentially with the appropriate t-Boc-protected amino acids in a Beckman 990-B peptide synthesizer, 990-B.
1.83 Grams of the protected peptide resin was obtained and was divided into two equal parts of 0.915 g each.
Synthesis of ##STR18##
One part of the protected peptide resin from above was further sequentially coupled with 1.5 mmoles of the appropriate Boc amino acids and β-(S-MeBzl)-Pmp-OH to give 1.16 g of the final protected peptide resin. Pmp(S-MeBzl)-D-Tyr(Et)-Phe-Gly-Asn-Cys(4MeBzl)-Pro-Arg-(Tos)MBHA resin was obtained and dried in vacuo. This protected resin was treated with 1.5 ml of anisole and 25 ml of anhydrous hydrogen fluoride at 0° for 1 hour. The deprotected peptide was treated with 0.01 mole of potassium ferricyanide solution at pH 7.2 in 2 liters of water. 53 Ml of the oxidizing agent was used.
The resulting solution was passed through a C 18 flash column. The column was eluted with 50% of acetonitrile with 0.25% trifluoroacetic acid in 20 ml per fraction. 325 Mg crude product was isolated from the fractions. Further purification of the product by CCD (B/A/W, 4:1:5) to obtain 188 mg of 99% pure titled product.
______________________________________Amino acid analysis:______________________________________Peptide content 82%Asp 1.04 Tyr 0.92Pro 1.15 Phe 1.01Gly 1.00 Arg 0.91Cys 0.54FAB/MS = m/z (M + H).sup.+ 1037______________________________________
EXAMPLE 9
Synthesis of ##STR19##
One part of the protected peptide resin from Example 8 was further sequentially coupled with 1.5 mmoles of the appropriate Boc amino acids and β-(S-4-MeBzl)-Pmp-OH to give 1.06 g of the final protected peptide resin, Pmp(S-4-MeBzl)-D-Tyr(Et)-Phe-Chg-Asn-Cys(S-4-MeBzl)-Pro-Arg-(Tos)MBHA resin, obtained after drying in vacuo.
This protected peptide resin was treated with 1.5 ml of anisole and 25 ml of anhydrous hydrogen fluoride.
Following the usual oxidation by potassium ferricyanide and isolation over a C 18 column, 165 mg crude titled product was obtained. Further purification by CCD G-15 and P-2 gel filtration as described above gave 55 mg HPLC pure titled product.
Peptide content: 88%
FAB/MS: m/z 1119 (M+H) +
EXAMPLE 10
Preparation of ##STR20## and its use for preparing the compound of Example 3
4.87 g (15 mmol) of the BocCys(4MeBzl) was dissolved in 30 ml of ethanol and 10 ml of water added. The pH was then adjusted to 7.1 with an aqueous solution of cesium bicarbonate.
The mixture was concentrated and the residue evaporated three times from 50 ml of toluene. This residue was, then, placed under high vacuum at ambient temperature overnight.
The salt was dissolved in 35 ml of dimethylformamide and 5 g of commercial chloromethylphenyl resin added. The mixture was stirred at 53° under argon overnight.
The mixture was filtered and the resin washed with dimethylformamide (5×60 ml), DMF/Water, 9:1, (5×60 ml), DMF (5×60 ml) and ethanol (6×60 ml). It was, then, dried under high vacuum at ambient temperature over the weekend.
The peptide chain was built up in a Beckman synthesizer as described above using the Boc derivatives of Asn, Val, Phe, D-Tyr(Et) and the S-(4-MeBzl) Pmp derivative. The resin was removed and placed in a manual shaker.
0.86 G of the peptide resin was treated with 1.5 ml of anisole and stirred for 60 min at 0° in 15 ml of hydrogen fluoride. The hydrogen fluoride was, then, removed under aspirator pressure at 0°.
The residue was then washed with 3×25 ml of ether (discarded) and the peptide eluted with dimethylformamide and 30% acetic acid (4×10 ml). This solution was added to 21 of degassed water and the pH adjusted to 7.0 with ammonium hydroxide. A 0.01M potassium ferricyanide solution was added slowly (35 ml).
The pH was then adjusted to 4.5 with acetic acid and the mixture stirred for 30 minutes with 25 g (WET) of a weakly basic ion exchange resin (AG-3×4 1R-4S). The suspension was filtered and the resin washed with 2×400 ml of 30% acetic acid.
The filtrate was, then, passed thru a C 18 flash column (7×16 mm). The column was then washed with water (3×400 ml) and the peptide eluted with acetonitrile/water/TFA, 50:50:0.25). Fractions 30→36 were combined, concentrated and lyophillized to yield 25 mg of the titled free Cys(OH)cyclic intermediate.
FAB mass spectrum in glycerol: 827 (M+H) + , 825 (M-H) - .
The Cys acid (20 mg) is reacted with one equivalent of Pro-Arg(NH 2 )HCl (prepared from the commercial dihydrochloride by treatment with 1 equivalent of triethylamine) in the presence of DCC and HBT in dimethylformamide to produce the compound of Example 3. Similarly, Pro(OMe) is attached to the Cys acid, hydrolyzed with mild sodium hydroxide to give the Pro acid which is, then, reacted with Arg(HCl)(OMe) to give the acid parent of the compound of Example 3 after mild hydrolysis of the ester. This compound is isolated as the potassium salt if desired. See Example 12 below. Alternatively, the Pro-Arg(NH 2 ) is used in the condensation directly.
A mixture of 4.5 mg of Pmp-D-Tyr(Et)-Phe-Val-Asn-Cys-OH prepared as above and 1 ml of methanol was treated with ethereal diazomethane and purified by preparing HPLC (50% CH 3 CN/50% H 2 O/0.1% TFA) to yield 4.3 mg of the methyl ester (94%), FABMS m/z 841 (M+H) + , homogeneous by HPLC and TLC.
EXAMPLE 11
Preparation of ##STR21##
BocPro-Merrifield resin was made by coupling BocPro to Merrifield resin using the cesium salt method to give Boc-Pro-OCH 2 -C 6 H 4 -resin which was used as the starting material for the synthesis. The synthesis was carried out on the Beckman 990-B peptide synthesizer using the following protocol. Three equivalents of the amino acids were dissolved in their appropriate solvents [the Boc derivatives of 4MeBzl-Cys, Val, Phe in methylene chloride, Asn in dimethylformamide, X such as D-Tyr(Et) or BrBz-D-Tyr in 1:1 methylene chloride/dimethylformamide and 4MeBzl-Pmp in methylene chloride] and were coupled using an equimolar amount of dicyclohexylcarbodiimide (DCC) and 1-hydroxybenzotriazole (HOBT) except for the coupling of 4MeBzl Pmp where 1.0 equivalent of dimethylaminopyridine was used as catalyst. The extent of coupling was determined by qualitative ninhydrin analyses and couplings were repeated when necessary. The Boc groups were removed using 1:1 trifluoroacetic acid/methylene chloride and after washing the free amine was generated using 5% diisopropylethylamine/methylene chloride. The sequence of the peptide was checked using solid phase sequencing before the coupling of the 4MeBzl-Pmp and its homogeneity confirmed. After the final coupling, the resin was dried to give 2.24 g of peptide resin in the case of the D-Tyr(Et) 2 -Pro 7 compound.
1.1 G (0.5 mmole) of the D-Tyr(Et) 2 peptide resin with 3 ml of anisole was stirred 60 min. at 0° (ice bath) in 25 ml of hydrogen fluoride (HF). The HF was, then, removed under reduced pressure at 0°. The residue was washed with ethyl ether (4×20 ml, discarded) and the peptide eluted with dimethylformamide 3×10 ml, 20% acetic acid 3×10 ml and 0.3N ammonium hydroxide 3×10 ml.
The filtrate was added to 2 l of degassed water and the pH adjusted to 7.1 with conc. ammonium hydroxide. A 0.01M solution of potassium ferricyanide was then added dropwise with stirring until a faint yellow color persisted (41 ml). This solution was adjusted to pH=4.7 with acetic acid and stored in the cold overnight.
The solution was adjusted to pH=7 with ammonia and stirred for 15 min with 30 g of AG-3×4 Bio-Rad ion exchange resin (wet, Cl form). This solution was then filtered slowly through an additional 30 g of resin. The resin was then washed with 4×200 ml of 20% acetic acid and the filtrate stored in the cold overnight.
The filtrate was then passed through a flash column (5 cm×10 cm) of a packing of silica gel coated with a C-18 silane. The column was then, washed with 350 ml of water and the peptide eluted with 500 ml of 1:1 acetonitrile/water (0.25% trifluoroacetic acid) in 20 ml fractions.
Fractions 11-17 were combined and concentrated. The residue was dissolved in conc. acetic acid, diluted with water and lyophillized to yield 189 mg of the D-Tyr(Et) 2 , proline peptide, which was used without further purification for the synthesis of the tail modified peptides.
______________________________________Identification of:______________________________________ ##STR22##Amino Acid Analysis: Peptide Content 55% Asp, 1.00; Pro, 1.23; Cys, 0.35; Val; 1.04, Tyr(Et), 1.43; Phe, 1.51.HPLC: Satisfactory. ##STR23##Amino Acid Analysis: Peptide Content 82% Asp, 0.97; Pro, 1.10; Cys, 0.39; Val, 1.05; Tyr, 0.99; Phe, 0.99HPLC: Satisfactory, 30% CH.sub.3 CN/70% 0.05 m KH.sub.2 PO.sub.4,2 ml/min, 5 uC-18, k' = 6.14.______________________________________
A mixture of 10 mg of the D-Tyr(Et)-Pro(OH) 7 prepared as above, and 1 ml of methanol was treated with ethereal diazomethane and, then, purified by preparing HPLC (50% CH 3 CN/50% H 2 O/0.1% TFA) to yield 7.5 mg of the methyl ester (74%), FABMS m/z 938 (M+H + ), homogeneous by HPLC and TLC.
To a solution of the D-Tyr(Et) 2 -proline heptapeptide, prepared as described above, (29.7 mg, 0.0331 mmol), and Arg(NH 2 ) (0.0996 mmol) in dimethylformamide (400 μl), dicyclohexylcarbodiimide (10.3 mg, 0.05 mmol) and dimethylaminopyridine (0.05 mmol) were added and the reaction mixture was stirred at 0°-20° for 4 hours. The dimethylformamide was, then, removed under vacuum. The residue was treated as above in Example 3 in 45% yield to give the desired D-Tyr(Et) 2 -Val 4 amide.
EXAMPLE 12
Synthesis and Characterization of ##STR24##
The linear peptidyl resin, Pmp(S-MeBzl)-D-Tyr(Et)-Phe-Val-Asn-Cys(S-MeBzl)-Pro-D-Arg(Tos)-BHA resin, was prepared by the solid phase method using the standard protocol described above. Thus, 1.5 g benzhydrylamine resin corresponding to 1.0 mmol amine was coupled successively with the Boc amino acid derivatives in threefold excess using DCC/HOBt in methylene chloride/DMF, 1:1. Pmp(S-MeBzl) was coupled with DCC/DMAP. Completeness of coupling was checked with the Kaiser test or a quantitative ninhydrin test. Recoupling was performed until the test was negative.
The protected peptidyl resin was washed with successive portions of methylene chloride, methanol, ethyl acetate and methylene chloride, and, then, air dried. The peptide was cleaved from the resin with 15 ml of liquid hydrogen fluoride in the presence of 1.0 ml of anisole at 0° for one hour. After evaporation of the hydrogen fluoride and drying under high vacuum, the resin was washed with 3×20 ml of ether and, then, extracted with 2×50 ml of 50% acetic acid, 50 ml of 10% acetic acid, and 50 ml of water. The combined extracts were diluted to 4 l with water and the pH adjusted to 7.2 with 50% sodium hydroxide solution. The solution was titrated with 0.01M K 3 Fe(CN) 6 solution until a yellow color persisted (30 ml). The pH was adjusted to 4.5 with glacial acetic acid and filtered. The filtrate was applied to a cation exchange (BioRex-70) column (H+ form), washed with water and then eluted with 100 ml of pyridine acetate buffer (30 ml of pyridine, 4 ml of acetic acid, 66 ml of water). The eluant was evaporated to dryness. The residue was dissolved in a small amount of 10% acetic acid and diluted with water to 1% acetic acid, then lyophilized, yielding 650 mg of the crude titled peptide.
The crude peptide was purified by counter current distribution in n-butanol/acetic acid/water (B/A/W) (4:1:5) yielding 33 mg partially purified peptide. This was further purified by gel filtration on a Sephadex G-15 column in 1% acetic acid, yielding 24.5 mg pure peptide. Amino acid analysis (hydrolysis in HCl/TFA 2:1, 0.005% phenol for 1 hr.) Asp 1.00, Pro 0.72, Cys 0.62, Val 0.99, Tyr 1.04, Phe 1.04, Arg 0.95, 71% peptide. HPLC: (40% acetonitrile/60% water/0.01% TFA), one peak, k'=5.2; (45% acetonitrile/55% water/0.1% TFA) k'=3.6; (gradient 20% acetonitrile, 5'; 20-50% acetonitrile, 20'; 50% acetonitrile, 5') k'=8.7, 97% pure. Tlc: rf 0.32 (B/A/W 1:1:1); 0.12 (B/A/W 4:1:1); 0.50 (n-butanol/pyridine/acetic acid/water), 15:10:3:12).
The extracted peptidyl resin still contained peptide by amino acid analysis, so it was extracted with 3×50 ml of DMF. The DMF was evaporated to dryness and the residue dissolved in 10% HOAc, diluted to 1% acetic acid and lyophilized, yielding an additional 260 mg of peptide. FAB mass spectrometry of this material gave a m/z 1079 which corresponds to M+H for the desired cyclic peptide.
EXAMPLE 13
Substituting a stoichiometric quantity of Boc-D-Phe for Boc-D-Try(Br-Z) at the 2 unit of the peptide synthesis of Example 1 gives ##STR25##
Substituting Boc-D-Val at the same position using the splitting-oxidation reactions of Example 2 gives ##STR26##
Substituting Boc-D-Leu in Example 1 gives ##STR27##
Substituting β-mercapto-β,β-cyclotetramethylenepropionic acid (Tmp) for Pmp in Example 5 gives ##STR28## β-Mercapto-β,β-cyclohexamethylenepropionic acid gives the Hmp 1 derivative.
Substituting in Example 1 Boc-D-Nle at the 2 unit and D-Arg(Tos) at the 8 unit gives ##STR29##
Substituting in Example 2 Boc-D-Cha at the 2 unit gives ##STR30##
Substituting in Example 1 Boc-α-aminophenylbutyric acid (Pba) at the 2 unit gives ##STR31##
Substituting Boc-Lys(ClZ) in Example 3 for the protected Arg gives ##STR32##
Other representative compounds which are prepared in like manner are: ##STR33##
EXAMPLE 14
Parenteral Dosage Unit Compositions
A preparation which contains 0.5 mg of the cyclic octapeptide of Examples 1 or 3 as a sterile dry powder for parenteral injection is prepared as follows: 0.5 mg of peptide amide is dissolved in 1 ml of an aqueous solution of 20 mg of mannitol. The solution is filtered under sterile conditions into a 2 ml ampoule and lyophylized. The powder is reconstituted before either intramuscular or intravenous injection to a subject suffering from edema susceptible to anti-ADH mechanism of action. The injection is repeated as necessary, from 1-5 times daily or in continuous i.v. drug injection. Other octapeptides of this invention are made up and used in like manner.
Nasal Dosage Unit Compositions
30 Mg of finely ground octapeptide of this invention such as the product of Example 2 is suspended in a mixture of 75 mg of benzyl alcohol and 1.395 g of a suspending agent such as a commercial mixture of semisynthetic glycerides of higher fatty acids. The suspension is placed in an aerosol 10 ml container which is closed with a metering valve and charged with aerosol propellants. The contents comprise 100 unit doses which are administered intranasally to an edematous subject from 1-6 times a day. | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of U.S. application Ser. No. 10/387,759, filed Mar. 13, 2003, now U.S. Pat. No. 6,727,360, which in turn is a divisional of U.S. application Ser. No. 09/610,819, filed Jul. 6, 2000, now U.S. Pat. No. 6,562,965, which in turn is a divisional of U.S. application Ser. No. 09/282,508, filed Mar. 31, 1999, now U.S. Pat. No. 6,107,508, which in turn claims benefit of U.S. provisional application No. 60/080,680, filed Apr. 3, 1998. The entirety of these foregoing applications is incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
This invention relates to a general and convergent synthesis of α-aryl-β-ketonitriles. Base-promoted isomerization of 3-unsubstituted-4-arylisoxazoles, followed by acidification of the resulting enolates provides the title α-aryl-β-ketonitriles. The corresponding 3-unsubstituted-4-arylisoxazoles were prepared from cross coupling reaction between 4-iodo-5-substituted isoxazole or 4-bromo-5-substituted isoxazole and arylboronic acids under the influence of a suitable catalyst. The α-aryl-β-ketonitriles of the present invention serve as synthetic intermediates in the preparation of a series of biologically important molecules such as corticotropin releasing factor (CRF) receptor antagonists.
BACKGROUND
α-Aryl-β-ketonitriles are important building blocks in the construction of complicated molecular system including natural products and biologically important molecules. They are generally prepared from condensation of α-aryl acetonitriles with the corresponding alkyl carboxylates in the presence of a base, such as sodium ethoxide (Scheme 1)(J. Am. Chem. Soc. 1951, 73, 3763; J. Med. Chem. 1991, 34, 1721). However, α-arylacetonitriles, which are usually prepared from cyanation of the corresponding benzyl halides, sometimes are not readily accessible due to the substitution pattern on the corresponding aromatic ring.
3-Unsubstituted isoxazoles may be cleaved by bases (Advances in Heterocyclic Chemistry, 1979, 25, 147; Tandem Organic Reactions, 1992, 288; Tetrahedron Lett. 1986, 27, 2027; J. Org. Chem. 1996, 61, 5435). Claisen showed that treatment of 5-phenylisoxazole with sodium ethoxide in absolute ethanol or with aqueous sodium hydroxide at room temperature yields, after acidification, ω-cyano-acetophenone (Ber. 1891, 24, 130). Isoxazole itself is cleaved to the sodium salt of cyanoacetaldehyde (Ber. 1903, 36, 3664). The isomerization of 3-unsubstituted isoxazoles to α-cyano carbonyl compounds under the influence of bases takes place readily at room temperature (Scheme 2).
Kinetic studies on the isomerization of 3-unsubstituted isoxazoles have established that the reaction is second order (first order in base and in substrate) and that the mechanism of the reaction belongs to a concerted one-stage E2 type rather than to a two-step E1cB type (Scheme 3) (Gazz. Chim. Ital. 1960, 90, 356; Chim. Ind. (Milan), 1966, 48, 491; Gazz. Chim. Ital. 1967, 97, 185). The effective isolation of the α-cyanoketone, however, depends on the stability of the latter compound, which is often unstable and readily dimerizes and/or polymerizes (Helv. Chim. Acta, 1963, 46, 543; Ger. Offen. 2,623,170; Chem. Abstr. 1978, 88, 62159).
The α-aryl-β-ketonitriles of the present invention serve as synthetic intermediates in the preparation of a series of biologically important molecules such as corticotropin releasing factor (CRF) receptor antagonists. The present invention describes a process for preparing 3-unsubstituted 4-aryl-isoxazoles and their use in preparing α-aryl-β-ketonitriles. Although methods are available for the preparation of some substituted isoxazoles, selective, high-yielding methods which produce pure crude intermediates for the preparation of 3-unsubstituted 4-arylisoxazoles are unknown in the art.
The present invention describes a convergent preparation of substituted α-aryl-β-ketonitriles (I).
The process includes reacting a substituted isoxazole with a halogenating agent to give a haloisoxazole (Scheme 4).
The literature teaches the synthesis of 4-iodo-5-methylisoxazole by iodination of 5-methylisoxazole with I 2 in the presence of a oxidizing agent such as concentrated nitric acid but gives poor conversion under the reported optimized conditions. The present invention discloses an efficient synthesis of 4-iodo-5-methylisoxazole by treating commercially available 5-methylisoxazole with NIS in strong organic acidic medium, such as trifluroacetic acid, which results in an unexpected yield and purity which is critical for commercial drug preparation.
The present invention also discloses an efficient and regioselective aromatic bromination method for the effective production of the brominated aromatic compound.
A phenyl group containing an electron donating functionality in the aromatic ring, is reacted with N-bromosuccinimide followed by reacting the lithium salt of the product with a alkylborate in situ to produce a phenyl boronic after acidic hydrolysis (Scheme 5). This intermediate is coupled directly with the haloisoxale to give the isomerization precursor (Scheme 6).
Finally, a very efficient protocol for the isomerization of 4-aryl substituted isoxazoles to the corresponding α-aryl-β-ketonitriles under the influence
of a base, such as sodium methoxide is described. (Scheme 7). Due to the efficiency of the preceeding reaction, a crude cross coupling product can be used to conduct this base-promoted isomerization reaction, providing the corresponding α-aryl-β-ketonitriles directly, with exceptional purity which is beneficial for large-scale preparation of the drug substance.
Commonly-assigned U.S. provisional application No. 08/899,242, filed Jul. 23, 1997, disclosed 2,4,7,8-tetra-substituted pyrazolo[1,5-a]-1,3,5-triazines derivatives and their use in treating CRF-related abnormalities. By improving the core structure synthesis, a convergent, and therefore more efficient synthesis has been developed. This general synthetic method has been successfully used in the large-scale synthesis of this important class of corticotropin releasing factor (CRF) receptor antagnists.
SUMMARY OF THE INVENTION
The present invention relates generally to processes for the conversion of α-aryl-β-ketonitriles to pyrazolo [1,5-a]-1,3,5-triazine derivatives for the purpose of producing compounds, and intermediates therefore, which are useful antagonists of the corticotropin releasing factor (CRF) receptor. These compounds may be used for the treatment of (CRF) related abnormalities such as depression and anxiety. There is provided by this invention a process for the preparation of compounds of formula (I), (III), (IV), (V) and (VI):
wherein:
r is an integer from 0 to 4; R 1 is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, —NR 1c R 1d , —OR 1e , and —SR 1e ;
R 1c and R 1d are independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl and C 4 –C 12 cycloalkylalkyl;
alternatively, R 1c and R 1d are taken together to form a heterocyclic ring selected from the group consisting of:
piperidine, pyrrolidine, piperazine, N-methylpiperazine, morpholine and thiomorpholine, each heterocyclic ring optionally substituted with 1–3 C 1 –C 4 alkyl groups;
R 1e is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl;
R 2 is selected from the group consisting of:
H, C 2 –C 4 alkenyl, C 2 –C 4 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 10 cycloalkylalkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 haloalkyl, and C 1 –C 4 alkyl substituted with 0–5 R 2a ,
R 2a is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, halo, CN, C 1 -C 4 haloalkyl, —OR 2e , and —SR 2e ; and
R 2e is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl;
said process comprising the steps of:
(1) contacting a compound of formula (II):
with a suitable halogenating agent to form a compound of formula (III);
(2) contacting the compound of formula (III) with alkylborate in the presence of a strong base to give a compound of formula (IV) after acidic hydrolysis;
(3) contacting the compound of formula (IV) with a compound of formula (V) in the presence of a catalyst and a suitable weak base to give a compound of formula (VI); and
(4) contacting the compound of formula (VI) with an isomerization base to give a compound of formula (I), or a pharmaceutically acceptable salt form thereof.
DETAILED DESCRIPTION OF THE INVENTION
In a first embodiment, the present invention provides a process for the preparation of compounds of formula (I):
or a pharmaceutically acceptable salt form thereof;
wherein:
r is an integer from 0 to 4;
R 1 is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, —NR 1c R 1d , —OR 1e , and —SR 1e ;
R 1c and R 1d are independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl and C 4 –C 12 cycloalkylalkyl;
alternatively, R 1c and R 1d are taken together to form a heterocyclic ring selected from the group consisting of:
piperidine, pyrrolidine, piperazine, N-methylpiperazine, morpholine and thiomorpholine, each heterocyclic ring optionally substituted with 1–3 C 1 –C 4 alkyl groups;
R 1e is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl;
R 2 is selected from the group consisting of:
H, C 2 –C 4 alkenyl, C 2 –C 4 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 10 cycloalkylalkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 haloalkyl, and C 1 –C 4 alkyl substituted with 0–5 R 2a ;
R 2a is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, halo, CN, C 1 –C 4 haloalkyl, —OR 2e , and —SR 2e ; and
R 2e is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl;
the process comprising the steps of:
(1) contacting a compound of formula (II):
with a halogenating agent to form a compound of formula (III):
wherein X is a halogen derived from the halogenating agent;
(2) contacting the compound of formula (III) with a strong base followed by addition of an alkylborate to form a compound of formula (IV):
(3) contacting the compound of formula (IV) with a compound of formula (V):
wherein Y is a second halogen;
in the presence of a catalyst and a weak base to form a compound of formula (VI):
(4) contacting the compound of formula (VI) with an isomerization base to form a compound of formula (I), or a pharmaceutically acceptable salt form thereof.
In a preferred embodiment, r is an integer from 0–3; X is bromine; Y is iodine; R 1 is independently selected at each occurrence from the group consisting of hydrogen, methyl and methoxy; and R 2 is methyl.
In another preferred embodiment, in step 1, the halogenating agent is N-bromosuccinimide and X is bromine;
in step 2, the alkylborate is selected from the group consisting of:
trimethylborate, triethylborate, tripropylborate, triisopropylborate, tributylborate, triisobutylborate, tri-sec-butylborate, and tri-t-butylborate;
the strong base is selected from the group consisting of:
isobutyllithium, n-hexyllithium, n-octyllithium, n-butyllithium, s-butyllithium, t-butyllithium, phenyllithium and triphenylmethyllithium;
in step 3, the weak base is a phosphate buffer having a pH of about 7 to about 10 or sodium bicarbonate; Y is iodine; the catalyst is tetrakis(triphenylphosphine) palladium(0) or [1,1′-Bis(diphenylphosphino)ferrocene] palladium (II) chloride; and in step 4, the isomerization base is selected from the group consisting of:
lithium methoxide, sodium methoxide, potassium methoxide, lithium ethoxide, sodium ethoxide, potassium ethoxide, lithium tert-butoxide, sodium tert-butoxide, and potassium tert-butoxide.
In a more preferred embodiment, the halogenating agent is N-bromosuccinimide, the alkylborate is triisopropyl-borate, the strong base is n-butyllithium, the catalyst is [1,1′-Bis(diphenylphosphino) ferrocene]palladium(II) chloride, the weak base is sodium bicarbonate, the isomerization base is sodium methoxide, and the compound of formula (I) is:
or a pharmaceutically acceptable salt form thereof.
In another preferred embodiment, the compound of formula (V) is prepared by contacting a compound of formula (VII):
with a second halogenating agent to give a compound of formula (V).
In a second embodiment, the present invention describes a process for the preparation of a compound of formula (V):
wherein:
Y is a halogen R 2 is selected from the group consisting of:
H, C 2 –C 4 alkenyl, C 2 –C 4 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 10 cycloalkylalkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 haloalkyl, and C 1 –C 4 alkyl substituted with 0–5 R 2a ;
R 2a is independently selected from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, halo, CN, C 1 –C 4 haloalkyl, —OR 2e and —SR 2e ;
R 2e is selected from the group consisting of: H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl;
the process comprising contacting a compound of formula (VII):
with a halogenating agent in an organic acid to form a compound of formula (V).
In a preferred embodiment, R 2 is methyl, the halogenating agent is N-iodosuccinimide, and the organic acid is triflouroacetic acid.
In a third embodiment, the present invention provides a process for the preparation of a compound of formula (I):
or a pharmaceutically acceptable salt form thereof;
wherein:
r is an integer from 0 to 4; R 1 is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, —NR 1c R 1d , —OR 1e , and —SR 1e ;
R 1c and R 1d are independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl and C 4 –C 12 cycloalkylalkyl;
alternatively, R 1c and R 1d are taken together to form a heterocyclic ring selected from the group consisting of:
piperidine, pyrrolidine, piperazine, N-methylpiperazine, morpholine and thiomorpholine, each heterocyclic ring optionally substituted with 1–3 C 1 –C 4 alkyl groups;
R 1e is selected from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl;
R 2 is selected from the group consisting of:
H, C 2 –C 4 alkenyl, C 2 –C 4 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 10 cycloalkylalkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 haloalkyl, and C 1 –C 4 alkyl substituted with 0–5 R 2a ;
R 2a is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, halo, CN, C 1 –C 4 haloalkyl, —OR 2e , and —SR 2e ; and
R 2e is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl;
the process comprising the steps of:
(1) contacting a compound of formula (IV):
with a compound of formula (V):
wherein Y is a halogen;
in the presence of a catalyst and a weak base to give a compound of formula (VI):
(2) contacting the compound of formula (VI) with an isomerization base to give a compound of formula (I), or a pharmaceutically acceptable salt form thereof.
In a preferred embodiment, r is an integer from 0–3,
Y is iodine, R 1 is independently selected at each occurrence from the group consisting of hydrogen, methyl and methoxy, and R 2 is methyl.
In another preferred embodiment, in step 1, the weak base is sodium bicarbonate or a phosphate buffer with pH of about 7 to about 10;
the catalyst is tetrakis(triphenylphosphine)palladium(0) or [1,1′-Bis(diphenylphosphino)ferrocene]palladium(II) chloride; and in step 2, the isomerization base is selected from the group consisting of:
lithium methoxide, sodium methoxide, potassium methoxide, lithium ethoxide, sodium ethoxide, potassium ethoxide, lithium tert-butoxide, sodium tert-butoxide, and potassium tert-butoxide.
In a more preferred embodiment, the weak base is sodium bicarbonate, the catalyst is [1,1′-Bis(diphenyl-phosphino)ferrocene]palladium(II) chloride, and the isomerization base is sodium methoxide.
In a fourth embodiment, the present invention provides a process for the preparation of a compound of formula (VI):
or a pharmaceutically acceptable salt form thereof;
wherein:
r is an integer from 0 to 4; R 1 is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, —NR 1c R 1d , —OR 1e , and —SR 1e ;
R 1c and R 1d are independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl and C 4 –C 12 cycloalkylalkyl;
alternatively, R 1c and R 1d are taken together to form a heterocyclic ring selected from the group consisting of:
piperidine, pyrrolidine, piperazine, N-methylpiperazine, morpholine and thiomorpholine, each heterocyclic ring optionally substituted with 1–3 C 1 –C 4 alkyl groups;
R 1e is selected from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl;
R 2 is selected from the group consisting of:
H, C 2 –C 4 alkenyl, C 2 –C 4 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 10 cycloalkylalkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 haloalkyl, and C 1 –C 4 alkyl substituted with 0–5 R 2a ;
R 2a is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, halo, CN, C 1 –C 4 haloalkyl, —OR 2e , and —SR 2e ; and
R 2e is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl;
the process comprising contacting a compound of formula (IV):
with a compound of formula (V):
in the presence of [1,1′-Bis(diphenylphosphino)ferrocene]palladium(II) chloride, sodium bicarbonate and a suitable solvent to give a compound of formula (VI).
In a preferred embodiment, R 2 is methyl, the suitable solvent is tert-butyl methyl ether, and the compound of formula (IV) is:
In a fifth embodiment, the present invention describes a compound of formula (VI):
wherein:
r is an integer from 0 to 4; R 1 is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, —NR 1c R 1d , —OR 1e , and —SR 1e ;
R 1c and R 1d are independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl and C 4 –C 12 cycloalkylalkyl;
alternatively, R 1c and R 1d are taken together to form a heterocyclic ring selected from the group consisting of:
piperidine, pyrrolidine, piperazine, N-methylpiperazine, morpholine and thiomorpholine, each heterocyclic ring optionally substituted with 1–3 C 1 –C 4 alkyl groups;
R 1e is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl;
R 2 is selected from the group consisting of:
H, C 2 –C 4 alkenyl, C 2 –C 4 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 10 cycloalkylalkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 haloalkyl, and C 1 –C 4 alkyl substituted with 0–5 R 2a ;
R 2a is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, halo, CN, C 1 –C 4 haloalkyl, —OR 2e , and —SR 2e ; and
R 2e is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl.
In a sixth embodiment, the present invention describes a compound of formula (I):
wherein:
r is an integer from 0 to 4; R 1 is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, —NR 1c R 1d , —OR 1e , and —SR 1e ;
R 1c and R 1d are independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl and C 4 –C 12 cycloalkylalkyl;
alternatively, R 1c and R 1d are taken together to form a heterocyclic ring selected from the group consisting of:
piperidine, pyrrolidine, piperazine, N-methylpiperazine, morpholine and thiomorpholine, each heterocyclic ring optionally substituted with 1–3 C 1 –C 4 alkyl groups;
R 1e is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl;
R 2 is selected from the group consisting of:
H, C 2 –C 4 alkenyl, C 2 –C 4 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 10 cycloalkylalkyl, C 1 –C 4 hydroxyalkyl, C 1 –C 4 haloalkyl, and C 1 –C 4 alkyl substituted with 0–5 R 2a ;
R 2a is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 2 –C 10 alkenyl, C 2 –C 10 alkynyl, C 3 –C 6 cycloalkyl, C 4 –C 12 cycloalkylalkyl, halo, CN, C 1 –C 4 haloalkyl, —OR 2e , and —SR 2e ; and
R 2e is independently selected at each occurrence from the group consisting of:
H, C 1 –C 10 alkyl, C 3 –C 6 cycloalkyl, and C 4 –C 6 cycloalkylalkyl.
DEFINITIONS
The reactions of the synthetic methods claimed herein are carried out in suitable solvents which may be readily selected by one of skill in the art of organic synthesis, said suitable solvents generally being any solvent which is substantially nonreactive with the starting materials (reactants), the intermediates, or products at the temperatures at which the reactions are carried out, i.e., temperatures which may range from the solvent's freezing temperature to the solvent's boiling temperature. A given reaction may be carried out in one solvent or a mixture of more than one solvent. Depending on the particular reaction step, suitable solvents for a particular reaction step may be selected.
The following terms and abbreviations are used herein and defined as follows. The abbreviation: “THF” as used herein means tetrahydrofuran, “DMF” as used herein means N,N-dimethylformamide, “TBME” as used herein means tert-butyl methyl ether, “HPLC” as used herein means high performance liquid chromatograpy.
Suitable halogenated solvents include: carbon tetrachloride, bromodichloromethane, dibromochloromethane, bromoform, chloroform, bromochloromethane, dibromomethane, butyl chloride, dichloromethane, tetrachloroethylene, trichloroethylene, 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,1-dichloroethane, 2-chloropropane, hexafluorobenzene, 1,2,4-trichlorobenzene, o-dichlorobenzene, chlorobenzene, fluorobenzene, fluorotrichloromethane, chlorotrifluoromethane, bromotrifluoromethane, carbon tetrafluoride, dichlorofluoromethane, chlorodifluoromethane, trifluoromethane, 1,2-dichlorotetrafluorethane and hexafluoroethane.
Suitable ether solvents include: dimethoxymethane, tetrahydrofuran, 1,3-dioxane, 1,4-dioxane, furan, diethyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol dimethyl ether, anisole, or t-butyl methyl ether.
Suitable protic solvents may include, by way of example and without limitation, water, methanol, ethanol, 2-nitroethanol, 2-fluoroethanol, 2,2,2-trifluoroethanol, ethylene glycol, 1-propanol, 2-propanol, 2-methoxyethanol, 1-butanol, 2-butanol, i-butyl alcohol, t-butyl alcohol, 2-ethoxyethanol, diethylene glycol, 1-, 2-, or 3-pentanol, neo-pentyl alcohol, t-pentyl alcohol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, cyclohexanol, benzyl alcohol, phenol, or glycerol.
Suitable aprotic solvents may include, by way of example and without limitation, tetrahydrofuran (THF), dimethylformamide (DMF), dimethylacetamide (DMAC), 1,3-dimethyl-3,4,5,6-tetrahydro-2(1H)-pyrimidinone (DMPU), 1,3-dimethyl-2-imidazolidinone (DMI), N-methylpyrrolidinone (NMP), formamide, N-methylacetamide, N-methylformamide, acetonitrile, dimethyl sulfoxide, propionitrile, ethyl formate, methyl acetate, hexachloroacetone, acetone, ethyl methyl ketone, ethyl acetate, sulfolane, N,N-dimethylpropionamide, tetramethylurea, nitromethane, nitrobenzene, or hexamethylphosphoramide.
Suitable hydrocarbon solvents include: benzene, cyclohexane, pentane, hexane, toluene, cycloheptane, methylcyclohexane, heptane, ethylbenzene, m-, o-, or p-xylene, octane, indane, nonane, or naphthalene.
As used herein, “water immiscible organic solvents” are any of those solvents known in the art of organic synthesis to be suitable for aqueous work-up which are immiscible with water and capable of dissolving organic constituents. Examples include, but are not limited to chlorinated, hydrocarbon, ether, and hydrocarbon solvents.
As used herein, “aqueous acids” include, but are not limited to hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid, lithium, potassium, and sodium bisulfate, and ammonium chloride.
As used herein, “organic acid” includes, but is not limited to formic acid, acetic acid, propionic acid, butanoic acid, methanesulfonic acid, p-toluene sulfonic acid, trifluorosulfonic acid, benzenesulfonic acid, trifluoroacetic acid, propiolic acid, butyric acid, 2-butynoic acid, vinyl acetic acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid and decanoic acid.
As used herein, “weak base” includes, but is not limited to lithium, sodium, potassium bicarbonates, and buffers capable of buffering the solution to pH 6–10, by way of example, but without limitation, phosphate buffers, and borate buffers.
As used herein, “isomerization base” means any base capable of opening of a 3-unsubstituted isoxazoline ring to afford a beta-ketonitrile. Examples of such bases include, but are not limited to: lithium, sodium and potassium salts of methyl, ethyl and t-butyl oxides and lithium, sodium, and potassium hydrides.
As used herein, the term “strong base” refers to any agent which effects a halogen metal exchange in a halophenyl group. Examples of such strong bases include, but are not limited to, alkyllithiums, metal amides, metal hydrides, metal dialkylamides and arylamines, wherein; alkoxides include lithium, sodium and potassium salts of methyl, ethyl and t-butyl oxides; alkyllithiums include, isobutyllithium, n-hexyllithium, n-octyllithium, n-butyllithium, s-butyllithium, t-butyllithium, phenyllithium and triphenylmethyllithium; metal amides include sodium amide, potassium amide and lithium amide; metal hydrides include sodium hydride, potassium hydride and lithium hydride; and metal dialkylamides include sodium and potassium salts of methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, trimethylsilyl and cyclohexyl substituted amides.
As used herein, “halogenating agents” are those known in the art of organic synthesis capable of donating a halogen to an aromatic system such as isoxazole or phenyl. Such agents include but are not limited to chlorine, bromine, iodine, N-iodosuccinimide, N-chlorosuccinimide and N-bromosuccinimide.
As used herein, “catalyst” includes those which are known in the art of organic synthesis to facilitate a coupling reaction between a haloaryl group and a phenylboronic acid. Examples of such catalysts include but are not limited to, palladium catalysts such as tetrakis(triphenylphosphine)palladium(0) (Pd(PPh 3 ) 4 ), [1,1′-Bis(diphenylphosphino)ferrocene]palladium(II) chloride (Pd(dppf) 2 Cl 2 ), [1,2′-Bis(diphenylphosphino)ethane]palladium (II) chloride (Pd(dppe) 2 Cl 2 ), [1,3′-Bis(diphenylphosphino)propane]palladium(II) chloride (Pd(dppp) 2 Cl2), [1,4′-Bis(diphenylphosphino)butane]palladium (II) chloride (Pd(dppp) 2 Cl 2 ).
As used herein, “alkylborate” means any compound containing C 1-10 alkyl groups bonded through an oxygen to boron to give a formula (alkyl-O—) 3 B (a boronate ester) where the alkyl group is branched or a straight chain. Examples include, but are not limited to trimethyl, triethyl, tripropyl, triisopropyl, tributyl, triisobutyl, tri-sec-butyl, and tri-t-butylborate.
The compounds described herein may have asymmetric centers. Unless otherwise indicated, all chiral, diastereomeric and racemic forms are included in the present invention. Many geometric isomers of olefins, C═N double bonds, and the like can also be present in the compounds described herein, and all such stable isomers are contemplated in the present invention. It will be appreciated that compounds of the present invention that contain asymmetrically substituted carbon atoms may be isolated in optically active or racemic forms. Methods on how to prepare optically active forms from optically active starting materials are known in the art, such as by resolution of racemic forms or by synthesis. All chiral, diastereomeric, racemic forms and all geometric isomeric forms of a structure are intended.
The present invention includes all isotopes of atoms occurring in the intermediates or final compounds. Isotopes include those atoms having the same atomic number but different mass numbers. By way of general example and without limitation isotopes of hydrogen include tritium and deuterium.
When any variable (for example but not limited to R 1 , —OR 1e , etc.) occurs more than one time in any constituent or in any formula, its definition on each occurrence is independent of its definition at every other occurrence. Thus, for example, if a group is shown to be substituted with 0–3 R 1 , then said group may optionally be substituted with up to three R 1 , and R 1 at each occurrence is selected independently from the defined list of possible R 1 .
Combinations of substituents and/or variables are permissible only if such combinations result in stable compounds. By stable compound or stable structure it is meant herein a compound that is sufficiently robust to survive isolation to a useful degree of purity from a reaction mixture, and formulation into an efficacious therapeutic agent.
The term “substituted”, as used herein, means that any one or more hydrogen on the designated atom is replaced with a selection from the indicated group, provided that the designated atom's normal valency is not exceeded, and that the substitution results in a stable compound. When a substituent or substituents appears in a structure to be connected to the inside of a phenyl ring, those substituents may take any position which is chemically feasible, as a point of attachment on the phenyl ring.
As used herein, “alkyl” is intended to include both branched and straight-chain saturated aliphatic hydrocarbon groups having the specified number of carbon atoms; for example, C 1 –C 4 alkyl includes methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, s-butyl, and t-butyl; for example C 1 –C 10 alkyl includes C 1 –C 4 alkyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, and isomer thereof.
As used herein, any carbon range such as “C x –C y ” is intended to mean a minimum of “x” carbons and a maximum of “y” carbons representing the total number of carbons in the substituent to which it refers. For example, “C 4 –C 10 cycloalkylalkyl” could contain one carbon for “alkyl”, and three for the cycloalkyl group, giving a total of four carbons; or a larger number of carbons for each alkyl group, or larger ring, not to exceed a total of ten carbons.
“Alkenyl” is intended to include hydrocarbon chains of either a straight or branched configuration and one or more unsaturated carbon-carbon bonds which may occur in any stable point along the chain, such as ethenyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butadienyl and the like. “Alkynyl” is intended to include hydrocarbon chains of either a straight or branched configuration and one or more triple carbon-carbon bonds which may occur in any stable point along the chain, such as ethynyl, propynyl, butynyl and the like.
As used herein, “cycloalkyl” is intended to include saturated ring groups, including mono-, bi-, or poly-cyclic ring systems, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, and adamantyl. As used herein, “cycloalkylalkyl” represents a cycloalkyl group attached through an alkyl bridge.
As used herein, “halo” or “halogen” refers to fluoro, chloro, bromo and iodo. “Haloalkyl” as used herein refers to an alkyl group containing a specified number of carbon atoms optionally substituted with halogens.
As used herein, “pharmaceutically acceptable salts” refer to derivatives of the disclosed compounds wherein the intermediates or final compound are modified by making acid or base salts of the intermediates or final compounds. Examples of pharmaceutically acceptable salts include, but are not limited to, mineral or organic acid salts of basic residues such as amines; alkali or organic salts of acidic residues such as carboxylic acids; and the like.
The pharmaceutically acceptable salts of the intermediates or final compounds include the conventional non-toxic salts or the quaternary ammonium salts from non-toxic inorganic or organic acids. For example, such conventional non-toxic salts include those derived from inorganic acids such as hydrochloric, hydrobromic, sulfuric, sulfamic, phosphoric, nitric and the like; and the salts prepared from organic acids such as acetic, propionic, succinic, glycolic, stearic, lactic, malic, tartaric, citric, ascorbic, pamoic, maleic, hydroxymaleic, phenylacetic, glutamic, benzoic, salicylic, sulfanilic, 2-acetoxybenzoic, fumaric, toluenesulfonic, methanesulfonic, ethane disulfonic, oxalic, isethionic, and the like.
The pharmaceutically acceptable salts are generally prepared by reacting the free base or acid with stoichiometric amounts or with an excess of the desired salt-forming inorganic or organic acid or base in a suitable solvent or various combinations of solvents.
The pharmaceutically acceptable salts of the acids of the intermediates or final compounds are prepared by combination with an appropriate amount of a base, such as an alkali or alkaline earth metal hydroxide e.g. sodium, potassium, lithium, calcium, or magnesium, or an organic base such as an amine, e.g., dibenzylethylenediamine, trimethylamine, piperidine, pyrrolidine, benzylamine and the like, or a quaternary ammonium hydroxide such as tetramethylammoinum hydroxide and the like.
As discussed above, pharmaceutically acceptable salts of the compounds of the invention can be prepared by reacting the free acid or base forms of these compounds with a stoichiometric amount of the appropriate base or acid, respectively, in water or in an organic solvent, or in a mixture of the two; generally, nonaqueous media like ether, ethyl acetate, ethanol, isopropanol, or acetonitrile are preferred. Lists of suitable salts are found in Remington's Pharmaceutical Sciences , 17th ed., Mack Publishing Company, Easton, Pa., 1985, p. 1418, the disclosure of which is hereby incorporated by reference. The present invention is contemplated to be practiced on at least a multigram scale, kilogram scale, multikilogram scale, or industrial scale. Multigram scale, as used herein, is preferably the scale wherein at least one starting material is present in 10 grams or more, more preferably at least 50 grams or more, even more preferably at least 100 grams or more. Multikilogram scale, as used herein, is intended to mean the scale wherein more than one kilogram of at least one starting material is used. Industrial scale as used herein is intended to mean a scale which is other than a laboratory scale and which is sufficient to supply product sufficient for either clinical tests or distribution to consumers.
The methods of the present invention, by way of example and without limitation, may be further understood by reference to Scheme 8. Scheme 8 provides the general synthetic scheme for the synthesis of compounds of formula (I).
In Step 1, a phenyl derivative undergoes a regioselective bromination. The halogenating agent is preferably dissolved in a suitable solvent. The amount of halogenating agent is preferably about 1.0 to about 1.2 equivalents. Preferred solvents include polar aprotic solvents, such as N,N-dimethylformamide, dimethylsulfoxide, and dimethylacetamide. N,N-Dimethylformamide is most preferred. The amount of solvent is preferably about 3 mLs to about 7 mLs per gram of starting material. The phenyl derivative is preferably added to this solution dropwise at
a temperature of about −25° C. to about 40° C. Most preferred is about 20° C. to about 30° C. The reaction temperature is preferably maintained under about 20° C. to about 70° C. during the addition of the substrate. The resulting reaction mixture is preferably stirred at the preferred temperature for about 30 minutes to about 2 hours. More preferred is about 45 minutes to about 90 minutes. The reaction is considered complete preferably when the starting material is consumed, as evident by HPLC. A chromatograph of all reactions in the present invention may be obtained by performing an analysis on an aliquot of the reaction, preferably dissolved in one of the eluents. The reaction is preferably quenched by the addition of water and a suitable water immiscible organic solvent. Preferred solvents include hydrocarbons and ethers. Most preferred is heptane. The aqueous layer is preferably extracted with the organic solvent of choice and the organic layers are preferably combined. The organic layer is preferably washed with water to remove
any residual polar aprotic solvent. The organic layer is preferably washed with an aqueous salt solution such as aqueous sodium chloride. The organic solution is preferably dried and concentrated. Numerous methods of drying are suitable, including the addition of drying agents such as sodium or magnesium sulfate and azeotropic distillation. The addition of a drying agent is preferred followed by filtration. The solvent may be removed under vacuum and the product may be purified by recrystallization or distillation, the choice of which will be readily understood by one skilled in the art.
In Step 2, the product of Step 1 undergoes a halogen exchange. The salt of the anion generated is reacted with an alkylborate species to give a boronate ester, which yields the boronic acid derivative when hydrolyzed. The product from Step 1, is preferably dissolved in a suitable aprotic solvent. While numerous solvents are possible, ethers and hydrocarbons are preferred. Tetrahydrofuran is most preferred. The preferred amount of solvent is about 3
mLs to about 10 mLs per gram of starting material. The solution is preferably cooled and treated dropwise with
a solution of a strong base in a suitable solvent. Preferred bases include alkyl lithium bases. Butyllithium is most preferred. The preferred amount of base is about 1.0 equivalents to about 1.2 equivalents. The concentration of the base in the solvent is about 1.0 molar to about 2.6 molar. More preferred is about 2.4 molar to about 2.6 molar Preferable addition temperatures include about −78° C. to about −50° C. More preferred is about −70° C. to about −60° C. The resulting reaction mixture is preferably stirred at the preferred reduced temperature for a time sufficient to generate the phenyl anion, which is about 10 minutes to about 60 minutes. More preferred is about 15 minutes to about 40 minutes. The reaction is preferably treated dropwise with an alkylborate species. Most preferred is tri-isopropylborate. The preferred amount of alkylborate is about 1.0 equivalents to about 1.5 equivalents. Most preferred is about 1.1 equivalents to about 1.3 equivalents. The reaction mixture is preferably stirred at the reduced temperature for an additional period of time. Preferred is about 30 minutes to about 90 minutes. The reaction is preferably quenched at the reduced temperature with an aqueous acid. The preferred acid is saturated aqueous ammonium chloride solution. The resulting mixture is preferably gradually warmed to about −10° C. to about 10° C. for about 30 minutes to about 90 minutes and then preferably warmed to about 25° C. The layers are preferably separated, and the aqueous layer preferably extracted with a suitable, water immiscible organic solvent. The preferred solvent is ethyl acetate. More preferred is a mixture of ethyl acetate and tetrahydrofuran. The organic layers are preferably combined and washed with an aqueous salt solution such as aqueous sodium chloride. The organic solution is preferably dried and concentrated. Numerous methods of drying are suitable, including the addition of drying agents such as sodium or magnesium sulfate and azeotropic distillation. The addition of a drying agent is preferred followed by filtration. The solvent may be removed under vacuum and the product may be purified by recrystallization or distillation, the choice of which will be readily understood by one skilled in the art.
In Step 3, an isoxazole is selectively halogenated. While several halogenating agents may be used, iodine in the presence of a silver catalyst, N-iodosuccinimide (NIS), and N-bromosuccinimide (NBS) are preferred. When N-bromo-succinimide is used, the agent is preferably dissolved in
a suitable solvent, of which polar aprotic are preferred. N,N-dimethylformamide and dimethyl sulfoxide are more preferred. N,N-dimethylformamide is most preferred. If N-iodosuccinimide is used, the agent is preferably dissolved in a suitable organic acid solvent, of which trifluoro acetic and trifluorosulfonic acid are preferred. Most preferred is trifluoroacetic acid. If iodine is used, halogenated solvents, of which chloroform is preferred. The amount of solvent used is preferably about 3 to about 10 mls of solvent per gram of halogenating agent. The solution is preferably treated with the substrate isoxazole at room temperature or at an elevated temperature up to the boiling point of the solvent employed. More preferred is performing the addition at a reaction temperature from about 25° C. to about 30° C. Reaction temperature will affect the reaction rate, which will be readily understood by one skilled in the art. The reaction is considered complete preferably when the starting material is consumed, as evident by HPLC. By way of example, however, the bromination of 5-methylisoxazole using NBS reaches completion in about 20 hours to about 25 hours at the preferred temperature. The iodination using NIS in triflouroacetic acid reaches completion in about 2 hours to about 3 hours at the preferred temperature. The iodination
using iodine and trifluorosilver acetate reaches completion in about 4 to about 5 hours at the preferred temperature. The halogenation occurs regioselectively at the C-4 position of isoxazole derivatives. Furthermore, 5-methylisoxazole gave no side chain brominated products under the present conditions.
The crude halogenated product is preferably recovered by aqueous work-up. The reaction is preferably quenched with a suitable amount of water and a suitable water immiscible organic solvent. Numerous organic solvent are possible, of which chlorinated, ether, and hydrocarbon solvents are preferred. Heptane is most preferred. The reaction may generate succinimide which is preferably dissolved in the aqueous layer. If a polar aprotic solvent, or an organic acid is used in the reaction, it is preferably removed from the organic layer with repeated aqueous washing. The aqueous layer is preferably extracted with the organic solvent of choice and the organic layers are preferably combined. The organic layer may be washed with an aqueous salt solution such as aqueous sodium chloride. The organic solution
is preferably dried and concentrated. Numerous methods of drying are suitable, including the addition of drying agents such as sodium or magnesium sulfate and azeotropic distillation. The addition of magnesium sulfate is preferred followed by fitration. The solvent may be removed under vacuum and the product may be purified, preferably by recrystallization in a suitable solvent, the choice of which will be readily understood by one skilled in the art.
In Step 4, the product from Step 2 and Step 3 are coupled in the presence of a catalyst to give a phenyl-isoxazole system. A mixture of the isoxazole derivative produced in Step 3, and the boronic acid derivative produced in Step 2 are preferably mixed with a suitable aqueous base in a suitable solvent. Preferably, the amount of the boronic acid derivative is about 1.0 equivalents
to about 1.2 equivalents. While numerous solvents may be used, hydrocarbons and ethers are preferred with water mixtures of these solvents being preferred. More preferred is water mixtures with toluene, dimethoxyethane (DME), acetonitrile, and tetrahydrofuran. Dimethoxyethane and water is most preferred. Preferably, mixtures of solvents contain about equal amounts of each component, with the total amount preferably about 5 to about 20 mL per gram of each starting material. A phosphate buffer with a pH of about 7 to about 10 or sodium bicarbonate is preferred as the base. The amount of base may vary in range with about 1.0 equivalents to about 5.0 equivalents being preferred. About 2.0 to about 4.0 is more preferred. Even more preferred is sodium bicarbonate buffered to a pH of about 8 to about 9 with a phosphate buffer. Additional water may be added. The vessel may be degassed by purging with an inert gas. The solution is then preferably treated with a suitable catalyst at about 20° C. to about 30° C. Preferred catalysts include those known in the art to facilitate a Suzuki coupling, such as palladium (0) catalysts. More preferred is Pd(dppf) 2 Cl 2 or Pd(PPh 3 ) 4 . Most preferred is Pd(dppf) 2 Cl 2 . The reaction rate will be affected by the amount of catalyst used, which will be readily understood by one skilled in the art. The amount of catalyst may be from about 0.1% to about 10% by weight. More preferred is about 0.1% to about 3% by weight. Most preferred is about 0.5% to about 1.0% by weight. The resulting reaction mixture may be degassed. The solution is preferably warmed to about 60° C. to about 100° C. More preferred is about 75° C. to about 90° C. The reaction is considered complete preferably when the starting material is consumed, as evident by HPLC. The reaction temperature is then preferably cooled down to room temperature, before preferably being treated with an equal volume of water and a suitable water immiscible organic solvent. While many solvents may be used, ethers such as diethyl ether, t-butyl methyl ether or hydrocarbons such as heptane, hexane, pentane and toluene are preferred. Most preferred is t-butyl methyl ether. The two layers are preferably separated, and the aqueous layer was extracted with a water immiscible organic solvent. The aqueous layer is preferably extracted with the organic solvent and the organic layers are preferably combined. The organic layer may be washed with an aqueous salt solution such as aqueous sodium chloride. The organic solution is preferably dried and concentrated. Numerous methods of drying are suitable, including the addition of drying agents such as sodium or magnesium sulfate and azeotropic distillation. The addition of magnesium sulfate is preferred followed by fitration. The solvent may be removed under vacuum and the product may be purified, preferably by recrystallization in a suitable solvent, the choice of which will be readily understood by one skilled in the art.
In Step 5, the isoxazole system is opened with an isomerization base to give an α-aryl-β-ketonitrile. The crude material may be used directly in the following base-promoted isomerization reaction. The product of Step 4 is preferably dissolved in a protic solvent. Preferred are methanol, ethanol and isopropanal. Most preferred is methanol. The solution is preferably treated dropwise with a solution of a base. Alkoxide bases are preferred with sodium methoxide being most preferred. The amount of base is preferably about 1.0 to about 1.5 equivalents. More preferred is about 1.2 to about 1.4 equivalents. The base is preferably dissolved in a complimentary solvent to give a weight percent concentration of about 10% to about 50%. More preferred is about 20% to about 30%. Most preferred is a solution of about 25% sodium methoxide in methanol. The solution is preferably stirred at about 20° C. to about 30° C. The resulting reaction mixture is preferably stirred at this temperature for about 1 hour to about 8 hours. More preferred is about 2 to about 5 hours. The reaction is considered complete preferably when the starting material is consumed, as evident by HPLC. The reaction is preferably quenched by the addition of an equal volume of water and a suitable organic solvent. While numerous solvents may be used, ethers are preferred. Most preferred is t-butylmethyl ether. The two layers are preferably separated, and the aqueous layer may be extracted with a water immiscible organic solvent. The aqueous layer may be cooled, and is preferably treated dropwise with an aqueous acid. While numerous acids may be used, hydrochloric acid with a concentration of about 1 normal to about 6 normal is preferred. The addition of acid is preferably accompanied by monitoring the pH of the solution. The addition is complete when the pH is preferably about 5 to about 6. The solution is preferably extracted with the organic solvent and the combined organic extracts combined. The organic layer may be washed with an aqueous salt solution such as aqueous sodium chloride. The organic solution is preferably dried and concentrated. Numerous methods of drying are suitable, including the addition of drying agents such as sodium or magnesium sulfate and azeotropic distillation. The addition of magnesium sulfate is preferred followed by fitration. The solvent may be removed under vacuum and the product may be purified, preferably by recrystallization in a suitable solvent, the choice of which will be readily understood by one skilled in the art.
The present invention may be further exemplified without limitation by reference to Scheme 9.
EXAMPLE 1
4-Iodo-5-methylisoxazole (2)
A solution of NIS (200 g, 0.888 mol, 1.0 equiv) in CF 3 CO 2 H (340 mL) was treated dropwise with 5-methyl-isoxazole (1, 70.26 g, 0.846 mol) at 25° C. under N 2 . The reaction temperature was maintained under 55° C. during the addition of 5-methylisoxazole. The resulting reaction mixture was stirred at room temperature for an additional 30 min before being treated with H 2 O (1000 mL) and heptane (1000 mL). The two layers were separated, and the aqueous layer was extracted with heptane (200 mL), the combined organic extracts were washed with H 2 O (3×500 mL), saturated NaHCO 3 (500 mL), and saturated NaCl (500 mL), dried over MgSO 4 , and concentrated in vacuo. The crude product (2, 164.2 g, 176.8 g theoretical, 92.9%) was obtained as yellow to brown oil, which solidified at room temperature.
EXAMPLE 2
4-Iodo-5-methylisoxazole (2)
A solution of CF 3 CO 2 Ag (11.0 g, 50 mmol, 1.0 equiv) in CHCl 3 (100 mL) was treated with 5-methylisoxazole (1, 45.15 g, 50 mmol), and the resulting reaction mixture was treated with a solution of I 2 (12.7 g, 50 mmol, 1.0 equiv) in CHCl 3 (100 mL) at 25° C. under N 2 . The reaction mixture was then warmed to 40–45° C. for 4 h. Filtration of the cooled reaction mixture and the solids were washed with CH 2 Cl 2 (2×50 mL). The filtrates were then washed with water (2×50 mL) and saturated NaCl aqueous solution (50 mL), dried over MgSO 4 , and concentrated in vacuo. The crude product (2, 10.04 g, 10.45 g theoretical, 96%) was obtained as a thick oil.
EXAMPLE 3
4-Bromo-5-methylisoxazole (3).
A solution of NBS (97.9 g, 0.55 mol, 1.1 equiv) in DMF (500 mL) was treated dropwise with 5-methylisoxazole (1, 41.5 g, 0.5 mol) at 25° C. under N 2 . The resulting reaction mixture was stirred for an additional 24 h at room temperature before being treated with H 2 O (1000 mL) and heptane (1000 mL). The aqueous layer was extracted with heptane (500 mL), and the combined organic extractswere washed with H 2 O (4×400 mL), and saturated NaCl solution (400 mL), dried over MgSO 4 , and concentrated in vacuo. The crude product (3, 71.4 g, 81.0 g theoretical, 88.1%) was obtained as a pale-yellow oil.
EXAMPLE 4
4-Bromo-2,5-dimethylanisole (5)
A solution of NBS (306.9 g, 1.724 mol, 1.1 equiv) in DMF (850 mL) was treated dropwise with 2,5-dimethylanisole (4, 213.2 g, 220.9 mL, 1.567 mol) at 25° C. under N 2 . The reaction temperature was maintained under 60° C. during the addition of 2,5-dimethylanisole. The resulting reaction mixture was stirred at room temperature for an additional 1 h before being treated with H 2 O (2000 mL) and heptane (1000 mL). The two layers were separated and the aqueous layer was extracted with heptane (500 mL). The combined organic extracts were washed with H 2 O (4×800 mL), and saturated NaCl solution (500 mL), dried over MgSO 4 , and concentrated in vacuo. The crude product (5, 329.8 g, 336.9 g theoretical, 97.9%) was obtained as pale-yellow oil.
EXAMPLE 5
2,5-Dimethyl-4-methoxybenzeneboronic acid (6)
A solution of 4-bromo-2,5-dimethylanisole (5, 172 g, 0.8 mol) in anhydrous THF (800 ml) was treated dropwise with a solution of n-butyl lithium (2.5 M solution in hexane, 352 mL, 0.88 mol, 1.1 equiv) in hexane at −60–−65° C. under N 2 . The resulting reaction mixture was stired at −60–65° C. for an additional 30 min before being treated dropwise with B(OiPr) 3 (165.44 g, 203.2 mL, 0.88 mol, 1.1 equiv) at −60 to −65° C. The reaction mixture was stirred at −60 to −65° C. for an additional 1 h. The reaction was then quenched with saturated NH 4 Cl aqueous solution (750 mL) at −60 to −65° C., and the resulting mixture was gradually warmed to 0° C. for 1 h and subsequently to room temperature. The two layers were separated, and the aqueous layer was extracted with EtOAc/THF (1:1, 400 mL). The combined organic extracts were then washed with H 2 O (400 mL), and saturated NaCl solution (400 mL), dried over MgSO 4 , and concentrated in vacuo. The residual white solids were then suspended in heptane (500 mL), and the resulting suspension was stirred at room temperature for 30 min. The solids were collected by filtration and washed with heptane (2×200 mL), dried in vacuo at 40–45° C. for overnight. The crude product (6, 116.7 g, 144.0 g theoretical, 81%) was obtained as a white powder.
EXAMPLE 6
4-Methoxy-2-methylbenzeneboronic acid (8)
A solution of 4-bromo-3-methylanisole (7, 92 g, 0.457 mol) in anhydrous THF (400 ml) was treated dropwise with a solution of n-butyl lithium (2.5 M solution in hexane, 201 mL, 0.503 mol, 1.1 equiv) in hexane at −60–−65° C. under N 2 . The resulting reaction mixture was stired at −60–65° C. for an additional 30 min before being treated dropwise with B(OiPr) 3 (94.56 g, 116 mL, 0.503 mol, 1.1 equiv) at −60–−65° C. The reaction mixture was stirred at −60–−65° C. for an additional 1 h. The reaction was then quenched with saturated NH 4 Cl aqueous solution (400 mL) at −60–−65° C., and the resulting mixture was gradually warmed to 0° C. for 1 h and subsequently to room temperature. The two layers were separated, and the aqueous layer was extracted with EtOAc/THF (1:1, 200 mL). The combined organic extracts were then washed with H 2 O (200 mL), and saturated NaCl aqueous solution (200 mL), dried over MgSO 4 , and concentrated in vacuo. The residual white solids were then suspended in heptane (400 mL), and the resulting suspension was stirred at room temperature for 30 min. The solids were collected by filtration and washed with heptane (2×100 mL), dried in vacuo at 40–45° C. for overnight. The crude product (8, 57.9 g, 75.86 g theoretical, 76.3%) was obtained as a white powder.
EXAMPLE 7
(2,5-Dimethyl-4-methoxy)phenyl-5-methylisoxazole (9)
A mixture of 4-iodo-5-methylisoxazole (2, 4.18 g, 20 mmol), 2,5-dimethyl-4-methoxybenzeneboronic acid (6, 3.96 g, 22 mmol, 1.1 equiv), and NaHCO 3 (5.04 g, 60 mmol, 3.0 equiv) in DME (15 mL) and H 2 O (15 mL) was treated with Pd(dppf) 2 Cl 2 (163.2 mg, 0.2 mmol, 1% equiv) at 25° C. under N 2 , and the resulting reaction mixture was degassed for three times. The resulting reaction mixture was warmed to 80–85° C. for 4 h, which was then cooled down to room temperature before being treated with TBME (40 mL) and H 2 O (40 mL). The two layers were separated, and the aqueous layer was extracted with TBME (2×30 mL). The combined organic extracts were then washed with H 2 O (2×20 ml), and saturated aqueous NaCl (20 mL), dried over MgSO 4 , and concentrated in vacuo. The residue was then purified by flash chromatography (SiO 2 , 5–15% EtOAc-hexane gradient elution) to afford the desired Suzuki coupling product (9, 3.52 g, 4.34 g theoretical, 81.1%) as a colorless oil.
EXAMPLE 8
(4-Methoxy-2-methyl)phenyl-5-methylisoxazole (11)
A mixture of 4-iodo-5-methylisoxazole (2, 2.09 g, 10 mmol), 4-methoxy-2-methylbenzeneboronic acid (8, 1.826 g, 11 mmol, 1.1 equiv), and NaHCO 3 (2.52 g, 30 mmol, 3.0 equiv) in DME (8 mL) and H 2 O (8 mL) was treated with Pd(dppf) 2 Cl 2 (82 mg, 0.1 mmol, 1% equiv) at 25° C. under N 2 , and the resulting reaction mixture was degassed for three times. The resulting reaction mixture was warmed to 80–85° C. for 4 h, which was then cooled down to room temperature before being treated with TBME (40 mL) and H 2 O (40 mL).
The two layers were separated, and the aqueous layer was extracted with TBME (2×20 mL). The combined organic extracts were then washed with H 2 O (2×20 ml), and saturated aqueous NaCl (20 mL), dried over MgSO 4 , and concentrated in vacuo. The residue was then purified by flash chromatography (SiO 2 , 5–15% EtOAc-hexane gradient elution) to afford the desired Suzuki coupling product (11, 1.71 g, 2.03 g theoretical, 84.2%) as a colorless oil.
EXAMPLE 9
α-Acetyl-α-(2,5-dimethyl-4-methoxy)phenyl-acetonitrile (13)
A solution of pure 4-(2,5-dimethyl-4-methoxy)phenyl-5-methylisoxazole (9, 1.085 g, 5 mmol) in MeOH (10 mL) was treated dropwise with a solution of MeONa (25% w/w solution in methanol, 1.62 g, 1.7 mL, 7.5 mmol, 1.5 equiv) at room temperature under N 2 . The resulting reaction mixture was stirred at room temperature for 4 h before being treated with H 2 O (20 mL) and TBME (20 mL). The resulting mixture was then stirred at room temperature for 10 min. The two layers were separated, and the aqueous layer was extracted with TBME (10 mL). The aqueous layer was then cooled down to 10–15° C. and treated dropwise with 4 N HCl aqueous solution to pH 5–6 at 10–15° C. before being extracted with TBME (2×30 mL). The combined organicextracts were then washed with H 2 O (20 mL), saturated NaHCO 3 aqueous solution (10 mL), and saturated NaCl aqueous solution (10 mL), dried over MgSO 4 , and concentrated in vacuo. The crude desired product (13, 1.0 g, 1.085 g theoretical, 92%) was obtained as a yellow to brown oil, which was found to be a mixture of keto and enol form (about 4 to 7 in CDCl 3 ) in solution.
EXAMPLE 10
α-Acetyl-α-(2,5-dimethyl-4-methoxy)phenyl-acetonitrile (13)
A mixture of 4-iodo-5-methylisoxazole (2, 52.25 g, 0.25 mol), 2,5-dimethyl-4-methoxybenzeneboronic acid (6, 49.5 g, 0.275 mmol, 1.1 equiv), and NaHCO 3 (63 g, 0.75 mol, 3.0 equiv) in DME (175 mL) and H 2 O (175 mL) was treated with Pd(dppf) 2 Cl 2 (2.04 g, 2.5 mmol, 1% equiv) at 25° C. under N 2 , and the resulting reaction mixture was degassed for three times before being warmed to 80–85° C. for 4 h. The reaction mixture was cooled down to room temperature before being treated with TBME (300 mL) and H 2 O (300 mL). The two layers were separated, and the aqueous layer was extracted with TBME (200 mL). The combined organic extracts were then washed with H 2 O (2×150 mL), and saturated aqueous NaCl (150 mL), dried over MgSO 4 , and concentrated in vacuo. The crude brown oil was directly used in the following base-promoted isomerization reaction. The crude brown oil obtained from Suzuki coupling reaction was dissolved in MeOH (300 mL) and treated dropwise with a solution of MeONa (25% w/w solution in methanol, 70.2 g, 74 mL, 0.325 mol, 1.3 equiv) at room temperature under N 2 . The resulting reaction mixture was stirred at room temperature for 4 h before being treated with H 2 O (300 mL) and TBME (300 mL). The resulting mixture was then stirred at room temperature for 10 min. The two layers were separated, and the aqueous layer was extracted with TBME (100 mL). The aqueous layer was then cooled down to 10–15° C. and treated dropwise with 4 N HCl aqueous solution (88 mL, 0.35 mol, 1.4 equiv) to pH 5–6 at 10–15° C. before being extracted with TBME (2×300 mL). The combined organic extracts were then washed with H 2 O (2×150 mL), saturated NaHCO 3 aqueous solution (100 mL), and saturated NaCl aqueous solution (100 mL), dried over MgSO 4 , and concentrated in vacuo. The crude desired product (13, 44.6 g, 54.25 g theoretical, 82.2% for two steps) was obtained as a yellow to brown oil.
EXAMPLE 11
α-Acetyl-α-(4-methoxy-2-methyl)phenylacetonitrile (14)
A solution of pure 4-(4-methoxy-2-methyl)phenyl-5-methylisoxazole (11, 2.03 g, 10 mmol) in MeOH (20 mL) was treated dropwise with a solution of MeONa (25% w/w solution in methanol, 3.24 g, 3.4 mL, 15 mmol, 1.5 equiv) at room temperature under N 2 . The resulting reaction mixture was stirred at room temperature for 4 h before being treated with H 2 O (40 mL) and TBME (40 mL). The resulting mixture was then stirred at room temperature for 10 min. The two layers were separated, and the aqueous layer was extracted with TBME (20 mL). The aqueous layer was then cooled down to 10–15° C. and treated dropwise with 4 N HCl aqueous solution to pH 5–6 at 10–15° C. before being extracted with TBME (2×50 mL). The combined organic extracts were then washed with H 2 O (30 mL), saturated NaHCO 3 aqueous solution (20 mL), and saturated NaCl aqueous solution (20 mL), dried over MgSO 4 , and concentrated in vacuo. The crude desired product (14, 1.91 g, 2.03 g theoretical, 94.1%) was obtained as a yellow to brown oil, which was found to be a mixture of keto and enol form (about 5 to 1 in CDCl 3 ) in solution.
EXAMPLE 12
α-Acetyl-α-(4-methoxy-2-methyl)phenylacetonitrile (14)
A mixture of 4-iodo-5-methylisoxazole (2, 41.8 g, 0.2 mol), 4-methoxy-2-methylbenzeneboronic acid (8, 36.52 g, 0.22 mmol, 1.1 equiv), and NaHCO 3 (50.4 g, 0.6 mol, 3.0 equiv) in DME (140 mL) and H 2 O (140 mL) was treated with Pd(dppf) 2 Cl 2 (1.633 g, 2.0 mmol, 1% equiv) at 25° C. under N 2 , and the resulting reaction mixture was degassed for three times before being warmed to 80–85° C. for 4 h. The reaction mixture was cooled down to room temperature before being treated with TBME (250 mL) and H 2 O (250 mL). The two layers were separated, and the aqueous layer was extracted with TBME (200 mL). The combined organic extracts were then washed with H 2 O (2×100 mL), and saturated aqueous NaCl (100 mL), dried over MgSO 4 , and concentrated in vacuo. The crude brown oil was directly used in the following base-promoted isomerization reaction. The crude brown oil obtained from Suzuki coupling reaction was dissolved in MeOH (250 mL) and treated dropwise with a solution of MeONa (25% w/w solution in methanol, 56.16 g, 59 mL, 0.26 mol, 1.3 equiv) at room temperature under N 2 . The resulting reaction mixture was stirred at room temperature for 4 h before being treated with H 2 O (250 mL) and TBME (250 mL). The resulting mixture was then stirred at room temperature for 10 min. The two layers were separated, and the aqueous layer was extracted with TBME (100 mL). The aqueous layer was then cooled down to 10–15° C. and treated dropwise with 4 N HCl aqueous solution (70 mL, 0.28 mol, 1.4 equiv) to pH 5–6 at 10–15° C. before being extracted with TBME (2×250 mL). The combined organic extracts were then washed with H 2 O (150 mL), saturated NaHCO 3 aqueous solution (100 mL), and saturated NaCl aqueous solution (100 mL), dried over MgSO 4 , and concentrated in vacuo. The crude desired product (14, 33.3 g, 40.6 g theoretical, 82% for two steps) was obtained as a yellow to brown oil, which was found to be pure enough to do the next reaction.
HPLC Conditions (MF002DE):
Column: 25 cm × 4.6 mm id. Ultracarb 5 C8 (Phenomenex) Mobile Phase: A: 0.1% trifluoroacetic acid in HPLC grade water B: 0.1% trifluoroacetic acid in HPLC grade acetonitrile Gradient: t = 0 min 60% A 40% B t = 5 min 60% A 40% B t = 10 min 60% A 40% B t = 15 min 55% A 45% B t = 20 min 50% A 50% B t = 25 min 0% A 100% B t = 30 min 0% A 100% B Flow Rate: 1.0 mL/min Injection Volume: 5 microliters Stop Time: 30 minutes Post Time: 5 minutes Oven Temp.: ambient Detector: UV (220 nm)
Sample Prep.: Dissolve 25 mg of sample (dry solids weight) in to a sutable solvent adjust concentration to approximately 1 mg/ml. The sample concentration may be adjusted to ensure the proper quantitation. | 4y
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This is a division of application Ser. No. 07/539,064, filed June 15, 1990, now U.S. Pat. No. 5,061,560.
BACKGROUND OF THE INVENTION
I. Field of the Invention
The present invention relates to spherical grains of rare earth oxides useful in the manufacture of sintered products of rare earth oxides, and also to a method of manufacturing the spherical grains of rare earth oxides.
II. Description of the Prior Art
Conventionally, spherical grains of rare earth oxides are manufactured by adding water and then an organic or inorganic binder to a powder of the rare earth oxides to form a slurry. The slurry is molded and simultaneously dehydrated by known methods, such as, the slip cast method or the rubber press method. The mold is then dried and baked. Methods of casting reactive metals into ceramic molds are disclosed by Feagin U.S. Pat. Nos. 4,740,246 and 4,787,439. However, the green density (pre-sintering density) of the material is much less than the after-sintering density of the resulting sintered body because the coefficient of contraction is high. This seriously deforms the mold as it is dehydrated. It is thus difficult to obtain high dimensional precision in the resulting sintered body. Furthermore, the deformed sintered body acquires so much residual stress that its impact strength is poor and it has a high tendency to crack and break. As a result, the yield of the sintered body is lowered.
In an attempt to solve these problems, a rare earth oxide powder was granulated to form spherical grains having a relatively large mean grain diameter. A fine powder was added to the granulate to fill in the voids among the spherical grains and thereby attain the closest packing of the green powder, which was then molded and sintered. However, the spherical grains obtained by spray-drying a commercially available rare earth oxide powder having a mean grain diameter of from 3 to 6 μm are generally cavernous, and the thus obtained green powder has a relatively low density.
SUMMARY OF THE INVENTION
We have discovered a method to increase the density of the green powder, i.e., the pre-sintering density, and obtain spherical grains which are packed as closely as possible.
More particularly, we have found that it is possible to obtain "most-closely-packed" (referred to herein as voidless) spherical grains by first preparing a slurry of a rare earth oxide powder having a mean grain diameter of 1 μm or smaller in water, adding an organic acid salt as a binder to the slurry, and then spray-drying the slurry.
The inventive rare earth oxide grains are voidless, spherical and have a mean grain diameter of about 20-300 μm.
DETAILED DESCRIPTION OF THE INVENTION
According to the invention, the mean grain diameter of the rare earth oxide powder must not exceed 1 μm because, if it does, the resulting spherical grains will be cavernous, i.e., have large and/or many voids. Preferably, the mean grain diameter is from 0.8 to 1.0 μm. The rare earth oxide employed in the invention may be an oxide of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Y, or Sc, or a mixture thereof. The oxides of Y, Gd, and Er are preferred.
When the rare earth oxide powder having a mean grain diameter of 1 μm or smaller is mixed with an appropriate amount of water and the thus-prepared slurry is admixed with an organic acid salt, the slurry will have an increased density and a reduced viscosity. Also, its stability is improved so that the separation of the powder does not take place for a long time.
According to the invention, the salt of the organic acid may be sodium alginate, ammonium alginate, sodium carboxymethyl cellulose, ammonium carboxymethyl cellulose, or a mixture thereof. A preferred dosage of the organic acid salt is from about 0.01 to 1.00 weight part per 100 weight parts of rare earth oxides. A preferred concentration of the rare earth oxides solid in the slurry is from about 30 to 75 weight %. Through the addition of the organic acid salt, it is possible to control the slurry concentration, when the acid salt is added in an amount of from about 0.05 to 1.00 weight part per 100 weight parts of rare earth oxides. Specifically, the slurry concentration can be controlled in the range of from about 70 to 75 weight %, whereas when acid salt is not added, the slurry concentration can only be controlled within the range of less than about 66 weight %.
The slurry is thereafter spray-dried to form voidless spherical grains with a standard spray dryer. The conditions for carrying out the spray drying are conventional. However, if a particular range of mean grain diameter is desired for the resulting grains, the rotational speed of the disk of the spray drier, the feed rate of the slurry, the hot air flow rate, and the hot air temperature should be appropriately adjusted.
The following examples illustrate the invention. In the examples, all of the unit "part(s)" hereinafter employed are weight part(s), respectively.
EXAMPLE 1
As the starting rare earth oxide powder, Y 2 O 3 -SU [the suffix SU indicates a commercial product of Shin-Etsu Chemical Co., Ltd. of Japan], having a mean grain diameter (D 50 ) of ≦1 μm, was employed. Water was added to the powder and a slurry having a solid concentration of 55% was obtained. To this slurry was added ammonium carboxymethyl cellulose in an amount of 0.24 parts per 100 parts of Y 2 O 3 -SU. The slurry was then put through a spray drier and was thus granulated. The spray drying conditions were as follows:
slurry feed rate: 2 kg/hr
disk diameter: 55 mm φ
disk speed: 12,000 rpm
hot air temperature: 72° C.
hot air flow rate: 4 m 3 /min
The thus granulated spherical grains had a mean grain diameter of 49.5 μm, and the grain diameter distribution was between 20 and 80 μm. The bulk density of the grains was 1.8 g/cc. The spherical grains were admixed with one part of polyvinyl alcohol [C-17, a commercial product of Shin-Etsu Chemical Co., Ltd.], and the mixture was stirred well and formed into a disk plate of 100 mm diameter, which was then baked at a temperature of 1,700° C. The resulting sintered body had an after-sintering density of 4.9 g/cc, and the coefficient of contraction was 80%.
EXAMPLE 2
With the exception that Gd 2 O 3 -SU was employed as the starting rare earth oxide powder, the same procedure was carried out as in Example 1. The resulting spherical grains had a mean diameter of 44.2 μm and the grain diameter distribution was between 20 and 80 μm. The bulk density was 2.2 g/cc. The spherical grains were sintered in the same manner as in Example 1. The resulting sintered body had an after-sintering density of 7.43 g/cc, and the coefficient of contraction was 78%.
EXAMPLE 3
With the exception that Er 2 O 3 -SU was employed as the starting rare earth oxide powder, the same procedure was used as in Example 1. The resulting spherical grains had a mean diameter of 44.1 μm and the grain diameter distribution was between 20 and 80 μm. The bulk density was 2.2 g/cc. The spherical grains were sintered in the same manner as in Example 1. The resulting sintered body had an after-sintering density of 8.53 g/cc, and the coefficient of contraction was 76%.
COMPARATIVE EXAMPLE
With the exception that a commercial Y 2 O 3 having a mean diameter of 3.5 μm was used as the starting rare earth oxide powder, and that two parts of polyvinyl alcohol [C-17] per 100 parts of Y 2 O 3 were mixed in the slurry as the binder, the same granulation method was used as in Example 1. The resulting sintered body was similarly analyzed. The resulting grains had a mean diameter of 41 μm and the grain diameter distribution was between was between 20 and 80 μm. The bulk density was 0.9 g/cc. The grains were not spherical. The grains were admixed with one part of polyvinyl alcohol C-17 and the mixture was stirred well and formed into a disk plate of 100 mm diameter, which was then baked at a temperature of 1,700° C. The resulting sintered body had an after-sintering density of 4.2 g/cc, and the coefficient of contraction was 89%.
According to the results of the above comparison, the resulting grains of the present invention had a more spherical shape and a higher bulk density, namely 1.2 to about 2 g/cc, so that it is presumed they were far less cavernous and more closely packed. A sintered body formed of a mixture of these inventive spherical grains and the conventional rare earth oxides powder will have improved properties, such as, high after-sintering density and higher impact strength. | 4y
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BACKGROUND OF THE INVENTION
A. Field of the Invention
It is sometimes important, particularly for apartment dwellers, but also homeowners to prevent entry of an individual into the home. Most doors leading into a house or apartment have both the standard door lock as well as a deadbolt. This device would be inserted in the space between the deadbolt lock and the deadbolt plate from the inside of the door. A series of indentations or channels encircle the deadbolt handle. When the key is inserted into the deadbolt and turned this device would prevent the deadbolt from turning and unlocking the door.
B. Prior Art
There are many other examples of prior art, which are related to deadbolt security systems. Representative examples of these include Murphy, U.S. Pat. No. 5,052,202, Katsaros U.S. Pat. No. 4,715,200, and Runt U.S. Pat. No. 5,193,373.
The closest relevant prior art to the current idea is Murphy. In the Murphy application the top surface of the device fits over the deadbolt lock. A securement device is employed to prevent the deadbolt lock from moving in the event that a key is turned. Additionally, a set of forks surrounds the door handle. In Murphy the grooves are limited to two possible positions—vertical and horizontal—and are flush with the side of the deadbolt lock.
Unlike Murphy, the current device does not surround but is indented so that the device will be inserted behind the deadbolt. A series of indentations or channels, which are provided at different angles prevents the deadbolt from turning if entry is attempted. This series of indentations or channels are necessary in the event that the deadbolt is locked in other than a vertical or horizontal position. This device completely surrounds the door handle to insure that the device remains on the door when not in use.
Unlike the other referenced prior art this device does not required modification of the existing deadbolt door lock and has no moving parts.
BRIEF SUMMARY OF THE INVENTION
This is a device, which will prevent an unnecessary or unwanted intruder from entering a home, business or apartment when it is occupied. Most doors used a deadbolt locking system and this device prevents the deadbolt from turning when the key is being used to attempt to unlock the deadbolt.
This device is particularly helpful in situations such as apartment complexes when various individuals, i.e. maintenance personnel, apartment managers etc. must access the apartment for needed repairs. This could also be used by women as an added security measure in their homes or apartments.
Most standard apartments do not have a lock on the door knob and are only equipped with a deadbolt to secure the door. The door allows ingress and egress to the home, business or apartment while the deadbolt is the only means of providing securement of the door and is secured more firmly to the doorjamb. The deadbolt is comprised of the lock itself, an entry point for the key, plates for the interior and exterior of the door and a deadbolt handle, which is located in the interior of the building. The deadbolt handle moves when the door is locked and unlocked. The deadbolt handle allows the homeowner to securely lock the door after entry into the apartment or home.
This device will be inserted between the inside deadbolt plate surface and the surface of the deadbolt handle, which is closest to the door. A series of indentations or channels in the device, which are angled would surround the deadbolt when the device is installed. A hollow portion would be positioned between the placement behind the deadbolt and the door handle. The bottom portion would surround the door handle.
In operation as someone begins to turn the deadbolt from the exterior with a key the indentation or channel would prevent the deadbolt from turning the necessary number of degrees to allow the door to be unlocked. The device would use the door handle to further insure that the device would not slip off the deadbolt or door handle and prevents the deadbolt from turning.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of the device.
FIG. 2 is a back view of the device.
FIG. 3 is a side view of the device.
FIG. 4 is a view of the device installed on a door.
DETAILED DESCRIPTION OF THE EMBODIMENTS
This device is comprised of a top section 8 that surrounds the deadbolt of a standard deadbolt and a bottom section 9 that surrounds a door handle 10 . FIG. 4 The top portion 8 and bottom portion 9 are essentially circular and are connected to each other by two parallel connecting members 12 , which join the two circular portions of this device. FIG. 1 The space between the two connecting members is hollow to allow the device to slip over the door handle 10 and dead bolt handle 15 .
The top section 8 having an outer perimeter, is flat and circular with a hole in the center of the top section, wherein the hole defines an inner perimeter of the top section, which has an outer perimeter and an inner perimeter. FIG. 1 The deadbolt handle 15 fits within this portion of the device 5 . A series of indentations or channels 25 are provided on the top section with the bottom of the indentations or channels formed by a back surface of the top section and the indentations or channels having an opening extending through the outer and inner perimeter. Between the series of indentations or channels 25 are raised surfaces 30 . Although the device is flat with a series of indentations 25 , it allows the deadbolt handle 15 to fit within the indentations or channels 25 when it is installed. FIGS. 1 , 4
The indentations or channels 25 , which are provided, are large enough to allow the deadbolt handle 15 to be inserted within the indentation or channel and allow the deadbolt handle 15 to be surrounded by enough of the surface of the raised surfaces 30 to prevent the deadbolt handle 15 from turning the required amount of degrees to open the door when a key in inserted into the key entry on the outside.
The top portion would be installed such that it would fit between the faceplate 20 of the deadbolt and the back surface of the deadbolt handle 15 . FIG. 1 This would allow easy installation of this device and simplicity. No modification to the door assembly or to the deadbolt or lock of the door would be required.
Two connecting members 12 connect the top portion 8 of this device 5 to a bottom section 9 of this device 5 and form one integrated piece. These connecting members 12 are essentially parallel to each other. The bottom portion 9 when the device 5 is installed surrounds the door handle 10 on the bottom. The advantage to completely surrounding the door handle 10 is to ensure that the device stays on the door and also gives an added measure of protection to the deadbolt being turned when a key is placed in the deadbolt key entry access. Additionally when it is not in use the device can simply hang from the door and always be available and easily found.
This device 5 is designed to be lightweight and the choice of material may include plastic, rubber, or a variety of other materials. | 4y
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CROSS REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of U.S. patent application Ser. No. 09/608,244 entitled “Capillary Proximity Heads for Single Wafer Cleaning and Drying” filed on Jun. 30, 2000 now U.S. Pat. No. 6,488,040. The aforementioned patent application is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to semiconductor wafer cleaning and drying and, more particularly, to apparatuses and techniques for more efficiently removing fluids from wafer surfaces while reducing contamination and decreasing wafer cleaning cost.
2. Description of the Related Art
In the semiconductor chip fabrication process, it is well-known that there is a need to clean and dry a wafer where a fabrication operation has been performed that leaves unwanted residues on the surfaces of wafers. Examples of such a fabrication operation include plasma etching (e.g., tungsten etch back (WEB)) and chemical mechanical polishing (CMP). In CMP, a wafer is placed in a holder which pushes a wafer surface against a rolling conveyor belt. This conveyor belt uses a slurry which consists of chemicals and abrasive materials to cause the polishing. Unfortunately, this process tends to leave an accumulation of slurry particles and residues at the wafer surface. If left on the wafer, the unwanted residual material and particles may cause, among other things, defects such as scratches on the wafer surface and inappropriate interactions between metallization features. In some cases, such defects may cause devices on the wafer to become inoperable. In order to avoid the undue costs of discarding wafers having inoperable devices, it is therefore necessary to clean the wafer adequately yet efficiently after fabrication operations that leave unwanted residues.
After a wafer has been wet cleaned, the wafer must be dried effectively to prevent water or cleaning fluid remnants from leaving residues on the wafer. If the cleaning fluid on the wafer surface is allowed to evaporate, as usually happens when droplets form, residues or contaminants previously dissolved in the cleaning fluid will remain on the wafer surface after evaporation (e.g., and form spots). To prevent evaporation from taking place, the cleaning fluid must be removed as quickly as possible without the formation of droplets on the wafer surface. In an attempt to accomplish this, one of several different drying techniques are employed such as spin drying, IPA, or Marangoni drying. All of these drying techniques utilize some form of a moving liquid/gas interface on a wafer surface which, if properly maintained, results in drying of a wafer surface without the formation of droplets. Unfortunately, if the moving liquid/gas interface breaks down, as often happens with all of the aforementioned drying methods, droplets form and evaporation occurs resulting in contaminants being left on the wafer surface.
The most prevalent drying technique used today is spin rinse drying (SRD). FIG. 1 illustrates movement of cleaning fluids on a wafer 10 during an SRD drying process. In this drying process, a wet wafer is rotated at a high rate by rotation 14 . In SRD, by use of centrifugal force, the water or cleaning fluid used to clean the wafer is pulled from the center of the wafer to the outside of the wafer and finally off of the wafer as shown by fluid directional arrows 16 . As the cleaning fluid is being pulled off of the wafer, a moving liquid/gas interface 12 is created at the center of the wafer and moves to the outside of the wafer (i.e., the circle produced by the moving liquid/gas interface 12 gets larger) as the drying process progresses. In the example of FIG. 1 , the inside area of the circle formed by the moving liquid/gas interface 12 is free from the fluid and the outside area of the circle formed by the moving liquid/gas interface 12 is the cleaning fluid. Therefore, as the drying process continues, the section inside (the dry area) of the moving liquid/gas interface 12 increases while the area (the wet area) outside of the moving liquid/gas interface 12 decreases. As stated previously, if the moving liquid/gas interface 12 breaks down, droplets of the cleaning fluid form on the wafer and contamination may occur due to evaporation of the droplets. As such, it is imperative that droplet formation and the subsequent evaporation be limited to keep contaminants off of the wafer surface. Unfortunately, the present drying methods are only partially successful at the prevention of moving liquid interface breakdown.
In addition, the SRD process has difficulties with drying wafer surfaces that are hydrophobic. Hydrophobic wafer surfaces can be difficult to dry because such surfaces repel water and water based (aqueous) cleaning solutions. Therefore, as the drying process continues and the cleaning fluid is pulled away from the wafer surface, the remaining cleaning fluid (if aqueous based) will be repelled by the wafer surface. As a result, the aqueous cleaning fluid will want the least amount of area to be in contact with the hydrophobic wafer surface. Additionally, the aqueous cleaning solution tends cling to itself as a result of surface tension (i.e., as a result of molecular hydrogen bonding). Therefore, because of the hydrophobic interactions and the surface tension, balls (or droplets) of aqueous cleaning fluid forms in an uncontrolled manner on the hydrophobic wafer surface. This formation of droplets results in the harmful evaporation and the contamination discussed previously. The limitations of the SRD are particularly severe at the center of the wafer, where centrifugal force acting on the droplets is the smallest. Consequently, although the SRD process is presently the most common way of wafer drying, this method can have difficulties reducing formation of cleaning fluid droplets on the wafer surface especially when used on hydrophobic wafer surfaces.
Therefore, there is a need for a method and an apparatus that avoids the prior art by allowing quick and efficient cleaning and drying of a semiconductor wafer, but at the same time reducing the formation of numerous water or cleaning fluid droplets which may cause contamination to deposit on the wafer surface. Such deposits as often occurs today reduce the yield of acceptable wafers and increase the cost of manufacturing semiconductor wafers.
SUMMARY OF THE INVENTION
Broadly speaking, the present invention fills these needs by providing a cleaning and drying apparatus that is capable of removing fluids from wafer surfaces quickly while at the same time reducing wafer contamination. It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, a device or a method. Several inventive embodiments of the present invention are described below.
In one embodiment, a substrate preparation system is provided which includes a head having a head surface where the head surface is proximate to a surface of the substrate when in operation. The system also includes a first conduit for delivering a first fluid to the surface of the substrate through the head, and a second conduit for delivering a second fluid to the surface of the substrate through the head, where the second fluid is different than the first fluid. The system also includes a third conduit for removing each of the first fluid and the second fluid from the surface of the substrate where the first conduit, the second conduit and the third conduit act substantially simultaneously when in operation.
In another embodiment, a method for processing substrate is provided which includes applying a first fluid onto a surface of a substrate, and applying a second fluid onto the surface of the substrate where the second fluid is applied in close proximity to the application of the first fluid. The method also includes removing the first fluid and the second fluid from the surface of the substrate where the removing is processed just as the first fluid and the second fluid are applied to the surface of the substrate. The applying and the removing forms a controlled meniscus.
In yet another embodiment, a substrate preparation apparatus to be used in substrate processing operations is provided. The apparatus includes a proximity head being configured to move toward a substrate surface. The proximity head includes at least one of a first source inlet where the first source inlet applies a first fluid towards the substrate surface when the proximity head is in a position that is close to the substrate surface. The apparatus also includes at least one of a second source inlet where the second source inlet is configured to apply a second fluid towards the substrate surface when the proximity head is in the position that is close to the substrate surface. The apparatus further includes at least one of a source outlet where the source outlet is configured to apply a vacuum pressure to remove the first fluid and the second fluid from the substrate surface when the proximity head is in the position that is close to the substrate surface.
In another embodiment, a wafer cleaner and dryer to be used in wafer manufacturing operations is provided which includes a proximity head carrier assembly that travels in a linear movement along a radius of a wafer. The proximity head carrier assembly includes a first proximity head capable of being disposed over a wafer and a second proximity head capable of being disposed under the wafer. The proximity head carrier assembly also includes an upper arm connected with the first proximity head where the upper arm is configured so the first proximity head is movable into close proximity over the wafer to initiate one of a wafer cleaning and a wafer drying. The proximity head carrier assembly also includes a lower arm connected with the second proximity head where the lower arm is configured so the second proximity head is movable into close proximity under the wafer to initiate one of the wafer cleaning and the wafer drying.
In yet another embodiment, a method for cleaning and drying a semiconductor wafer is provided. In this embodiment, the method provides a proximity head which includes at least one of a first source inlet, at least one of a second source inlet, and at least one of a source outlet. The method also includes moving the proximity head toward a wafer surface, and generating a first pressure on a fluid film present on the wafer surface when the proximity head is in a first position that is close to the wafer surface. The method further includes generating a second pressure on the fluid film present on the wafer surface when the proximity head is in a first position that is close to the wafer surface, and introducing a third pressure on the fluid film present on the wafer surface when the proximity head is in the first position. The method also includes generating a pressure difference wherein the first pressure and the second pressure is greater than the third pressure, and the pressure difference causes the removal of the fluid film from the wafer surface.
In another embodiment, a substrate preparation apparatus to be used in substrate processing operations is provided. The apparatus includes a proximity head carrier assembly configured to travel in a linear movement along a radius of a substrate. The proximity head carrier assembly includes a first proximity head being disposed over a substrate and a second proximity head being disposed under the substrate. The assembly also includes an upper arm connected with the first proximity head where the upper arm is configured so the first proximity head is movable into close proximity over the substrate to initiate substrate preparation. The assembly further includes a lower arm connected with the second proximity head where the lower arm is configured so the second proximity head is movable into close proximity under the substrate to initiate substrate preparation.
The advantages of the present invention are numerous. Most notably, the apparatuses and methods described herein efficiently dry and clean a semiconductor wafer while reducing fluids and contaminants remaining on a wafer surface. Consequently, wafer processing and production may be increased and higher wafer yields may be achieved due to efficient wafer drying with lower levels of contamination. The present invention enables the improved drying and cleaning through the use of vacuum fluid removal in conjunction with fluid input. The pressures generated on a fluid film at the wafer surface by the aforementioned forces enable optimal removal of fluid at the wafer surface with a significant reduction in remaining contamination as compared with other cleaning and drying techniques. In addition, the present invention may utilize application of an isopropyl alcohol (IPA) vapor and deionized water towards a wafer surface along with generation of a vacuum near the wafer surface at substantially the same time. This enables both the generation and intelligent control of a meniscus and the reduction of water surface tension along a deionized water interface and therefore enables optimal removal of fluids from the wafer surface without leaving contaminants. The meniscus generated by input of IPA, DIW and output of fluids may be moved along the surface of the wafer to clean and dry the wafer. Therefore, the present invention evacuates fluid from wafer surfaces with extreme effectiveness while substantially reducing contaminant formation due to ineffective drying such as for example, spin drying.
Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the present invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings. To facilitate this description, like reference numerals designate like structural elements.
FIG. 1 illustrates movement of cleaning fluids on a wafer during an SRD drying process.
FIG. 2A shows a wafer cleaning and drying system in accordance with one embodiment of the present invention.
FIG. 2B shows an alternate view of the wafer cleaning and drying system in accordance with one embodiment of present invention.
FIG. 2C illustrates a side close-up view of the wafer cleaning and drying system holding a wafer in accordance with one embodiment of the present invention.
FIG. 2D shows another side close-up view of the wafer cleaning and drying system in accordance with one embodiment of the present invention.
FIG. 3A shows a top view illustrating the wafer cleaning and drying system with dual proximity heads in accordance with one embodiment of the present invention.
FIG. 3B illustrates a side view of the wafer cleaning and drying system with dual proximity heads in accordance with one embodiment of the present invention.
FIG. 4A shows a top view of a wafer cleaning and drying system which includes multiple proximity heads for a particular surface of the wafer in accordance with one embodiment of the present invention.
FIG. 4B shows a side view of the wafer cleaning and drying system which includes multiple proximity heads for a particular surface of the wafer in accordance with one embodiment of the present invention.
FIG. 5A shows a top view of a wafer cleaning and drying system with a proximity head in a horizontal configuration which extends across a diameter of the wafer 108 in accordance with one embodiment of the present invention.
FIG. 5B shows a side view of a wafer cleaning and drying system with the proximity heads in a horizontal configuration which extends across a diameter of the wafer in accordance with one embodiment of the present invention.
FIG. 5C shows a top view of a wafer cleaning and drying system with the proximity heads in a horizontal configuration which is configured to clean and/or dry the wafer that is stationary in accordance with one embodiment of the present invention.
FIG. 5D shows a side view of a wafer cleaning and drying system with the proximity heads in a horizontal configuration which is configured to clean and/or dry the wafer that is stationary in accordance with one embodiment of the present invention.
FIG. 5E shows a side view of a wafer cleaning and drying system with the proximity heads in a vertical configuration enabled to clean and/or dry the wafer that is stationary in accordance with one embodiment of the present invention.
FIG. 5F shows an alternate side view of a wafer cleaning and drying system that is shifted 90 degrees from the side view shown in FIG. 5E in accordance with one embodiment of the present invention.
FIG. 6A shows a proximity head inlet/outlet orientation that may be utilized to clean and dry the wafer in accordance with one embodiment of the present invention.
FIG. 6B shows another proximity head inlet/outlet orientation that may be utilized to clean and dry the wafer in accordance with one embodiment of the present invention.
FIG. 6C shows a further proximity head inlet/outlet orientation that may be utilized to clean and dry the wafer in accordance with one embodiment of the present invention.
FIG. 6D illustrates a preferable embodiment of a wafer drying process that may be conducted by a proximity head in accordance with one embodiment of the present invention.
FIG. 6E shows another wafer drying process using another source inlet/outlet orientation that may be conducted by a proximity head in accordance with one embodiment of the present invention.
FIG. 6F shows another source inlet and outlet orientation where an additional source outlet may be utilized to input an additional fluid in accordance with one embodiment of the present invention.
FIG. 7A illustrates a proximity head performing a drying operation in accordance with one embodiment of the present invention.
FIG. 7B shows a top view of a portion of a proximity head in accordance with one embodiment of the present invention.
FIG. 7C illustrates a proximity head with angled source inlets performing a drying operation in accordance with one embodiment of the present invention.
FIG. 8A illustrates a side view of the proximity heads for use in a dual wafer surface cleaning and drying system in accordance with one embodiment of the present invention.
FIG. 8B shows the proximity heads in a dual wafer surface cleaning and drying system in accordance with one embodiment of the present invention.
FIG. 9A shows a top view of a proximity head with a circular shape in accordance with one embodiment of the present invention.
FIG. 9B shows a side view of the proximity head with a circular shape in accordance with one embodiment of the present invention.
FIG. 9C illustrates a bottom view of the proximity head 106 - 1 with a circular shape in accordance with one embodiment of the present invention.
FIG. 10A shows a proximity head with an elongated ellipse shape in accordance with one embodiment of the present invention.
FIG. 10B shows a top view of the proximity head with an elongated ellipse shape in accordance with one embodiment of the present invention.
FIG. 10C shows a side view of the proximity head with an elongated ellipse shape in accordance with one embodiment of the present invention.
FIG. 11A shows a top view of a proximity head with a rectangular shape in accordance with one embodiment of the present invention.
FIG. 11B shows a side view of the proximity head with a rectangular shape in accordance with one embodiment of the present invention.
FIG. 11C illustrates a bottom portion of the proximity head in a rectangular shape in accordance with one embodiment of the present invention.
FIG. 12A shows a proximity head with a partial rectangular and partial circular shape in accordance with one embodiment of the present invention.
FIG. 12B shows a rear view of the proximity head with a partial rectangular and partial circular shape in accordance with one embodiment of the present invention.
FIG. 12C shows a top view of the proximity head with a partial rectangular and partial circular shape in accordance with one embodiment of the present invention.
FIG. 13A illustrates a top view of a proximity head with a circular shape similar to the proximity head shown in FIG. 9A in accordance with one embodiment of the present invention.
FIG. 13B shows the proximity head from a bottom view in accordance with one embodiment of the present invention.
FIG. 13C illustrates the proximity head from a side view in accordance with one embodiment of the present invention.
FIG. 14A shows a proximity head similar in shape to the proximity head shown in FIG. 12A in accordance with one embodiment of the present invention.
FIG. 14B illustrates a top view of the proximity head where one end is squared off while the other end is rounded in accordance with one embodiment of the present invention.
FIG. 14C shows a side view of a square end of the proximity head in accordance with one embodiment of the present invention.
FIG. 15A shows a bottom view of a 25 holes proximity head in accordance with one embodiment of the present invention.
FIG. 15B shows a top view of the 25 holes proximity head in accordance with one embodiment of the present invention.
FIG. 15C shows a side view of the 25 holes proximity head in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
An invention for methods and apparatuses for cleaning and/or drying a wafer is disclosed. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be understood, however, by one of ordinary skill in the art, that the present invention may be practiced without some or all of these specific details. In other instances, well known process operations have not been described in detail in order not to unnecessarily obscure the present invention.
While this invention has been described in terms of several preferred embodiments, it will be appreciated that those skilled in the art upon reading the preceding specifications and studying the drawings will realize various alterations, additions, permutations and equivalents thereof. It is therefore intended that the present invention includes all such alterations, additions, permutations, and equivalents as fall within the true spirit and scope of the invention.
FIGS. 2A through 2D below illustrate embodiments of an exemplary wafer processing system. It should be appreciated that the system is exemplary, and that any other suitable type of configuration that would enable movement of the proximity head(s) into close proximity to the wafer may be utilized. In the embodiments shown, the proximity head(s) may move in a linear fashion from a center portion of the wafer to the edge of the wafer. It should be appreciated that other embodiments may be utilized where the proximity head(s) move in a linear fashion from one edge of the wafer to another diametrically opposite edge of the wafer, or other non-linear movements may be utilized such as, for example, in a circular motion, in a spiral motion, in a zig-zag motion, etc. In addition, in one embodiment, the wafer may be rotated and the proximity head moved in a linear fashion so the proximity head may process all portions of the wafer. It should also be understood that other embodiments may be utilized where the wafer is not rotated but the proximity head is configured to move over the wafer in a fashion that enables processing of all portions of the wafer. In addition, the proximity head and the wafer cleaning and drying system described herein may be utilized to clean and dry any shape and size of substrates such as for example, 200 mm wafers, 300 mm wafers, flat panels, etc. The wafer cleaning and drying system may be utilized for either or both cleaning and drying the wafer depending on the configuration of the system.
FIG. 2A shows a wafer cleaning and drying system 100 in accordance with one embodiment of the present invention. The system 100 includes rollers 102 a, 102 b, and 102 c which may hold and rotate a wafer to enable wafer surfaces to be dried. The system 100 also includes proximity heads 106 a and 106 b that, in one embodiment, are attached to an upper arm 104 a and to a lower arm 104 b respectively. The upper arm 104 a and the lower arm 104 b are part of a proximity head carrier assembly 104 which enables substantially linear movement of the proximity heads 106 a and 106 b along a radius of the wafer.
In one embodiment the proximity head carrier assembly 104 is configured to hold the proximity head 106 a above the wafer and the proximity head 106 b below the wafer in close proximity to the wafer. This may be accomplished by having the upper arm 104 a and the lower arm 104 b be movable in a vertical manner so once the proximity heads are moved horizontally into a location to start wafer processing, the proximity heads 106 a and 106 b can be moved vertically to a position in close proximity to the wafer. The upper arm 104 a and the lower arm 104 b may be configured in any suitable way so the proximity heads 106 a and 106 b can be moved to enable wafer processing as described herein. It should be appreciated that the system 100 may be configured in any suitable manner as long as the proximity head(s) may be moved in close proximity to the wafer to generate and control a meniscus as discussed below in reference to FIGS. 6D through 8B . It should also be understood that close proximity may be any suitable distance from the wafer as long as a meniscus as discussed in further reference to FIGS. 6D through 8B may be maintained. In one embodiment, the proximity heads 106 a and 106 b (as well as any other proximity head described herein) may each be moved to between about 0.1 mm to about 10 mm from the wafer to initiate wafer processing operations. In a preferable embodiment, the proximity heads 106 a and 106 b (as well as any other proximity head described herein) may each be moved to between about 0.5 mm to about 4.5 mm from the wafer to initiate wafer processing operations, and in more preferable embodiment, the proximity heads 106 a and 106 b (as well as any other proximity head described herein) may be moved to about 2 mm from the wafer to initiate wafer processing operations.
FIG. 2B shows an alternate view of the wafer cleaning and drying system 100 in accordance with one embodiment of present invention. The system 100 , in one embodiment, has the proximity head carrier assembly 104 that is configured to enable the proximity heads 106 a and 106 b to be moved from the center of the wafer towards the edge of the wafer. It should be appreciated that the proximity head carrier assembly 104 may be movable in any suitable manner that would enable movement of the proximity heads 106 a and 106 b to clean and/or dry the wafer as desired. In one embodiment, the proximity head carrier assembly 104 can be motorized to move the proximity head 106 a and 106 b from the center of the wafer to the edge of the wafer. It should be understood that although the wafer cleaning and drying system 100 is shown with the proximity heads 106 a and 106 b, that any suitable number of proximity heads may be utilized such as, for example, 1, 2, 3, 4, 5, 6, etc. The proximity heads 106 a and/or 106 b of the wafer cleaning and drying system 100 may also be any suitable size or shape as shown by, for example, the proximity heads 106 , 106 - 1 , 106 - 2 , 106 - 3 , 106 - 4 , 106 - 5 , 106 - 6 , 106 - 7 which are discussed in reference to FIGS. 6 through 15 . The different configurations described herein generate a fluid meniscus between the proximity head and the wafer. The fluid meniscus may be moved across the wafer to clean and dry the wafer by applying fluid to the wafer surface and removing the fluids from the surface. Therefore, the proximity heads 106 a and 106 b can have any numerous types of configurations as shown herein or other configurations that enable the processes described herein. It should also be appreciated that the system 100 may clean and dry one surface of the wafer or both the top surface and the bottom surface of the wafer.
In addition, besides cleaning or drying both the top and bottom surfaces and of the wafer, the system 100 may also be configured to clean one side of the wafer and dry another side of the wafer if desired by inputting and outputting different types of fluids. It should be appreciated that the system 100 may utilize the application of different chemicals top and bottom in the proximity heads 106 a and 106 b respectively depending on the operation desired. The proximity heads can be configured to clean and dry the bevel edge of the wafer in addition to cleaning and/or drying the top and/or bottom of the wafer. This can be accomplished by moving the meniscus off the edge the wafer which cleans the bevel edge. It should also be understood that the proximity heads 106 a and 106 b may be the same type of head or different types of heads.
FIG. 2C illustrates a side close-up view of the wafer cleaning and drying system 100 holding a wafer 108 in accordance with one embodiment of the present invention. The wafer 108 may be held and rotated by the rollers 102 a, 102 b, and 102 c in any suitable orientation as long as the orientation enables a desired proximity head to be in close proximity to a portion of the wafer 108 that is to be cleaned or dried. In one embodiment, the roller 102 b may be rotated by using a spindle 111 , and the roller 102 c may held and rotated by a roller arm 109 . The roller 102 a may also be rotated by its own spindle (as shown in FIG. 3B . In one embodiment, the rollers 102 a , 102 b, and 102 c can rotate in a clockwise direction to rotate the wafer 108 in a counterclockwise direction. It should be understood that the rollers may be rotated in either a clockwise or a counterclockwise direction depending on the wafer rotation desired. In one embodiment, the rotation imparted on the wafer 108 by the rollers 102 a , 102 b, and 102 c serves to move a wafer area that has not been processed into close proximity to the proximity heads 106 a and 106 b. However, the rotation itself does not dry the wafer or move fluid on the wafer surfaces towards the edge of the wafer. Therefore, in an exemplary drying operation, the wet areas of the wafer would be presented to the proximity heads 106 a and 106 b through both the linear motion of the proximity heads 106 a and 106 b and through the rotation of the wafer 108 . The drying or cleaning operation itself is conducted by at least one of the proximity heads. Consequently, in one embodiment, a dry area of the wafer 108 would expand from a center region to the edge region of the wafer 108 in a spiral movement as a drying operation progresses. By changing the configuration of the system 100 and the orientation of and movement of the proximity head 106 a and/or the proximity head 106 b, the drying movement may be changed to accommodate nearly any suitable type of drying path.
It should be understood that the proximity heads 106 a and 106 b may be configured to have at least one of first source inlet configured to input deionized water (DIW) (also known as a DIW inlet), at least one of a second source inlet configured to input isopropyl alcohol (IPA) in vapor form (also known as IPA inlet), and at least one source outlet configured to output fluids from a region between the wafer and a particular proximity head by applying vacuum (also known as vacuum outlet). It should be appreciated that the vacuum utilized herein may also be suction. In addition, other types of solutions may be inputted into the first source inlet and the second source inlet such as, for example, cleaning solutions, ammonia, HF, etc. It should be appreciated that although IPA vapor is used in some of the exemplary embodiments, any other type of vapor may be utilized such as for example, nitrogen, any suitable alcohol vapor, organic compounds, etc. that may be miscible with water.
In one embodiment, the at least one IPA vapor inlet is adjacent to the at least one vacuum outlet which is in turn adjacent to the at least one DIW inlet to form an IPA-vacuum-DIW orientation. It should be appreciated that other types of orientations such as IPA-DIW-vacuum, DIW-vacuum-IPA, vacuum-IPA-DIW, etc. may be utilized depending on the wafer processes desired and what type of wafer cleaning and drying mechanism is sought to be enhanced. In a preferable embodiment, the IPA-vacuum-DIW orientation may be utilized to intelligently and powerfully generate, control, and move the meniscus located between a proximity head and a wafer to clean and dry wafers. The DIW inlets, the IPA vapor inlets, and the vacuum outlets may be arranged in any suitable manner if the above orientation is maintained. For example, in addition to the IPA vapor inlet, the vacuum outlet, and the DIW inlet, in an additional embodiment, there may be additional sets of IPA vapor outlets, DIW inlets and/or vacuum outlets depending on the configuration of the proximity head desired. Therefore, another embodiment may utilize an IPA-vacuum-DIW-DIW-vacuum-IPA or other exemplary embodiments with an IPA source inlet, vacuum source outlet, and DIW source inlet configurations are described in reference to FIGS. 7 to 15 with a preferable embodiment being described in reference to FIG. 6D .
FIG. 2D shows another side close-up view of the wafer cleaning and drying system 100 in accordance with one embodiment of the present invention. In this embodiment, the proximity heads 106 a and 106 b have been positioned in close proximity to a top surface 108 a and a bottom surface 108 b of the wafer 108 respectively by utilization of the proximity head carrier assembly 104 . Once in this position, the proximity heads 106 a and 106 b may utilize the IPA and DIW source inlets and a vacuum source outlet(s) to generate wafer processing meniscuses in contact with the wafer 108 which are capable of removing fluids from a top surface 108 a and a bottom surface 108 b . The wafer processing meniscus may be generated in accordance with the descriptions in reference to FIGS. 6 through 9B where IPA vapor and DIW are inputted into the region between the wafer 108 and the proximity heads 106 a and 106 b . At substantially the same time the IPA and DIW is inputted, a vacuum may be applied in close proximity to the wafer surface to output the IPA vapor, the DIW, and the fluids that may be on a wafer surface. It should be appreciated that although IPA is utilized in the exemplary embodiment, any other suitable type of vapor may be utilized such as for example, nitrogen, any suitable alcohol vapor, organic compounds, hexanol, ethylglycol, etc. that may be miscible with water. The portion of the DIW that is in the region between the proximity head and the wafer is the meniscus. It should be appreciated that as used herein, the term “output” can refer to the removal of fluid from a region between the wafer 108 and a particular proximity head, and the term “input” can be the introduction of fluid to the region between the wafer 108 and the particular proximity head.
In another exemplary embodiment, the proximity heads 106 a and 106 b may be moved in a manner so all parts of the wafer 108 are cleaned, dried, or both without the wafer 108 being rotated. In such an embodiment, the proximity head carrier assembly 104 may be configured to enable movement of the either one or both of the proximity heads 106 a and 106 b to close proximity of any suitable region of the wafer 108 . In one embodiment, the proximity heads may be configured to move in a spiral manner from the center to the edge of the wafer 108 or vice versa. In another embodiment, the proximity heads 104 a and 104 b may be configured to move in a linear fashion back and forth across the wafer 108 so all parts of the wafer surfaces 108 a and/or 108 b may be processed. In yet another embodiment, a configuration as discussed below in reference to FIGS. 5C through 5F may be utilized. Consequently, countless different configurations of the system 100 may be utilized in order to obtain an optimization of the wafer processing operation.
FIG. 3A shows a top view illustrating the wafer cleaning and drying system 100 with dual proximity heads in accordance with one embodiment of the present invention. As described above in reference to FIGS. 2A to 2D , the upper arm 104 a may be configured to move and hold the proximity head 106 a in a position in close proximity over the wafer 108 . The upper arm 104 a may also be configured to move the proximity head 106 a from a center portion of the wafer 108 towards the edge of the wafer 108 in a substantially linear fashion 113 . Consequently, in one embodiment, as the wafer 108 moves as shown by rotation 112 , the proximity head 106 a is capable of removing a fluid film from the top surface 108 a of the wafer 108 using a process described in further detail in reference to FIGS. 6 through 8 . Therefore, the proximity head 106 a may dry the wafer 108 in a substantially spiral path over the wafer 108 . In another embodiment as shown in reference to FIG. 3B , there may be a second proximity head located below the wafer 108 to remove a fluid film from the bottom surface 108 b of the wafer 108 .
FIG. 3B illustrates a side view of the wafer cleaning and drying system 100 with dual proximity heads in accordance with one embodiment of the present invention. In this embodiment, the system 100 includes both the proximity head 106 a capable of processing a top surface of the wafer 108 and the proximity head 106 b capable of processing a bottom surface of the wafer 108 . In one embodiment, spindles 111 a and 111 b along with a roller arm 109 may rotate the rollers 102 a , 102 b, and 102 c respectively. This rotation of the rollers 102 a , 102 b, and 102 c may rotate the wafer 108 so substantially all surfaces of the wafer 108 may be presented to the proximity heads 106 a and 106 b for drying and/or cleaning. In one embodiment, while the wafer 108 is being rotated, the proximity heads 106 a and 106 b are brought to close proximity of the wafer surfaces 108 a and 108 b by the arms 104 a and 104 b respectively. Once the proximity heads 106 a and 106 b are brought into close proximity to the wafer 108 , the wafer drying or cleaning may be begun. In operation, the proximity heads 106 a and 106 b may each remove fluids from the wafer 108 by applying IPA, deionized water and vacuum to the top surface and the bottom surface of the wafer 108 as described in reference to FIG. 6 .
In one embodiment, by using the proximity heads 106 a and 106 b , the system 100 may dry a 200 mm wafer in less than 3 minutes. It should be understood that drying or cleaning time may be decreased by increasing the speed at which the proximity heads 106 a and 106 b travels from the center of the wafer 108 to the edge of the wafer 108 . In another embodiment, the proximity heads 106 a and 106 b may be utilized with a faster wafer rotation to dry the wafer 108 in less time. In yet another embodiment, the rotation of the wafer 108 and the movement of the proximity heads 106 a and 106 b may be adjusted in conjunction to obtain an optimal drying/cleaning speed. In one embodiment, the proximity heads 106 a and 106 b may move linearly from a center region of the wafer 108 to the edge of the wafer 108 at between about 5 mm per minute to about 500 mm per minute.
FIG. 4A shows a top view of a wafer cleaning and drying system 100 ′ which includes multiple proximity heads for a particular surface of the wafer 108 in accordance with one embodiment of the present invention. In this embodiment, the system 100 ′ includes an upper arm 104 a - 1 and an upper arm 104 a - 2 . As shown in FIG. 4B , the system 100 ′ also may include lower arm 104 b - 1 and lower arm 104 b - 2 connected to proximity heads 106 b - 1 and 106 b - 2 respectively. In the system 100 ′, the proximity heads 106 a - 1 and 106 a - 2 (as well as 106 b - 1 and 106 b - 2 if top and bottom surface processing is being conducted) work in conjunction so, by having two proximity heads processing a particular surface of the wafer 108 , drying time or cleaning time may be cut to about half of the time. Therefore, in operation, while the wafer 108 is rotated, the proximity heads 106 a - 1 , 106 a - 2 , 106 b - 1 , and 106 b - 2 start processing the wafer 108 near the center of the wafer 108 and move outward toward the edge of the wafer 108 in a substantially linear fashion. In this way, as the rotation 112 of the wafer 108 brings all regions of the wafer 108 in proximity with the proximity heads so as to process all parts of the wafer 108 . Therefore, with the linear movement of the proximity heads 106 a - 1 , 106 a - 2 , 106 b - 1 , and 106 b - 2 and the rotational movement of the wafer 108 , the wafer surface being dried moves in a spiral fashion from the center of the wafer 108 to the edge of the wafer 108 .
In another embodiment, the proximity heads 106 a - 1 and 106 b - 1 may start processing the wafer 108 and after they have moved away from the center region of the wafer 108 , the proximity heads 106 a - 2 and 106 b - 2 may be moved into place in the center region of the wafer 108 to augment in wafer processing operations. Therefore, the wafer processing time may be decreased significantly by using multiple proximity heads to process a particular wafer surface.
FIG. 4B shows a side view of the wafer cleaning and drying system 100 ′ which includes multiple proximity heads for a particular surface of the wafer 108 in accordance with one embodiment of the present invention. In this embodiment, the system 100 ′ includes both the proximity heads 106 a - 1 and 106 a - 2 that are capable of processing the top surface 108 a of the wafer 108 , and proximity heads 106 b - 1 and 106 b - 2 capable of processing the bottom surface 108 b of the wafer 108 . As in the system 100 , the spindles 111 a and 111 b along with a roller arm 109 may rotate the rollers 102 a , 102 b, and 102 c respectively. This rotation of the rollers 102 a , 102 b, and 102 c may rotate the wafer 108 so substantially all surfaces of the wafer 108 may brought in close proximity to the proximity heads 106 a - 1 , 106 a - 2 , 106 b - 1 , and 106 b - 2 for wafer processing operations.
In operation, each of the proximity heads 106 a - 1 , 106 a - 2 , 106 b - 1 , and 106 b - 2 may remove fluids from the wafer 108 by applying IPA, deionized water and vacuum to the top surface and the bottom surface of the wafer 108 as shown, for example, in FIGS. 6 through 8 . By having two proximity heads per wafer side, the wafer processing operation (i.e., cleaning and/or drying) may be accomplished in substantially less time. It should be appreciated that as with the wafer processing system described in reference to FIGS. 3A and 3B , the speed of the wafer rotation may be varied to any suitable speed as long as the configuration enables proper wafer processing. In one embodiment, the wafer processing time may be decreased when half a rotation of the wafer 108 is used to dry the entire wafer. In such an embodiment, the wafer processing speed may be about half of the processing speed when only one proximity head is utilized per wafer side.
FIG. 5A shows a top view of a wafer cleaning and drying system 100 ″ with a proximity head 106 a - 3 in a horizontal configuration which extends across a diameter of the wafer 108 in accordance with one embodiment of the present invention. In this embodiment, the proximity head 106 a - 3 is held by an upper arm 104 a - 3 that extends across a diameter of the wafer 108 . In this embodiment, the proximity head 106 a - 3 may be moved into a cleaning/drying position by a vertical movement of the upper arm 104 a - 3 so the proximity head 106 a - 3 can be in a position that is in close proximity to the wafer 108 . Once the proximity head 106 a - 3 is in close proximity to the wafer 108 , the wafer processing operation of a top surface of the wafer 108 can take place.
FIG. 5B shows a side view of a wafer cleaning and drying system 100 ″ with the proximity heads 106 a - 3 and 106 b - 3 in a horizontal configuration which extends across a diameter of the wafer 108 in accordance with one embodiment of the present invention. In this embodiment, the proximity head 106 a - 3 and the proximity head 106 b - 3 both are elongated to be able to span the diameter of the wafer 108 . In one embodiment, while the wafer 108 is being rotated, the proximity heads 106 a - 3 and 106 b - 3 are brought to close proximity of the wafer surfaces 108 a and 108 b by the top arm 104 a and a bottom arm 106 b - 3 respectively. Because the proximity heads 106 a - 3 and 106 b - 3 extend across the wafer 108 , only half of a full rotation may be needed to clean/dry the wafer 108 .
FIG. 5C shows a top view of a wafer cleaning and drying system 100 ′″ with the proximity heads 106 a - 3 and 106 b - 3 in a horizontal configuration which is configured to clean and/or dry the wafer 108 that is stationary in accordance with one embodiment of the present invention. In this embodiment, the wafer 108 may be held stationary by any suitable type of wafer holding device such as, for example, an edge grip, fingers with edge attachments, etc. The proximity head carrier assembly 104 ′″ is configured to be movable from one edge of the wafer 108 across the diameter of the wafer 108 to an edge on the other side of the wafer 108 after crossing the entire wafer diameter. In this fashion, the proximity head 106 a - 3 and/or the proximity head 106 b - 3 (as shown below in reference to FIG. 5D ) may move across the wafer following a path along a diameter of the wafer 108 from one edge to an opposite edge. It should be appreciated that the proximity heads 106 a - 3 and/or 106 b - 3 may be move from any suitable manner that would enable moving from one edge of the wafer 108 to another diametrically opposite edge. In one embodiment, the proximity head 106 a - 3 and/or the proximity head 106 b - 3 may move in directions 121 (e.g., top to bottom or bottom to top of FIG. 5C ). Therefore, the wafer 108 may stay stationary without any rotation or movement and the proximity heads 106 a - 3 and/or the proximity head 106 b - 3 may move into close proximity of the wafer and, through one pass over the wafer 108 , clean/dry the top and/or bottom surface of the wafer 108 .
FIG. 5D shows a side view of a wafer cleaning and drying system 100 ′″ with the proximity heads 106 a - 3 and 106 b - 3 in a horizontal configuration which is configured to clean and/or dry the wafer 108 that is stationary in accordance with one embodiment of the present invention. In this embodiment, the proximity head 106 a - 3 is in a horizontal position with the wafer 108 also in a horizontal position. By use of the proximity head 106 a - 3 and the proximity head 106 b - 3 that spans at least the diameter of the wafer 108 , the wafer 108 may be cleaned and/or dried in one pass by moving proximity heads 106 a - 3 and 106 b - 3 in the direction 121 as discussed in reference to FIG. 5C .
FIG. 5E shows a side view of a wafer cleaning and drying system 100 ″″ with the proximity heads 106 a - 3 and 106 b - 3 in a vertical configuration enabled to clean and/or dry the wafer 108 that is stationary in accordance with one embodiment of the present invention. In this embodiment, the proximity heads 106 a - 3 and 106 b - 3 are in a vertical configuration, and the proximity heads 106 a - 3 and 106 b - 3 are configured to move either from left to right, or from right to left, beginning from a first edge of the wafer 108 to a second edge of the wafer 108 that is diametrically opposite to the first edge. Therefore, in such as embodiment, the proximity head carrier assembly 104 ′″ may move the proximity heads 104 a - 3 and 104 b - 3 in close proximity with the wafer 108 and also enable the movement of the proximity heads 104 a - 3 and 104 b - 3 across the wafer from one edge to another so the wafer 108 may be processed in one pass thereby decreasing the time to clean and/or dry the wafer 108 .
FIG. 5F shows an alternate side view of a wafer cleaning and drying system 100 ″″ that is shifted 90 degrees from the side view shown in FIG. 5E in accordance with one embodiment of the present invention. It should be appreciated that the proximity head carrier assembly 104 ′″ may be oriented in any suitable manner such as for example, having the proximity head carrier assembly 104 ′″ rotated 180 degrees as compared with what is shown in FIG. 5F .
FIG. 6A shows a proximity head inlet/outlet orientation 117 that may be utilized to clean and dry the wafer 108 in accordance with one embodiment of the present invention. In one embodiment, the orientation 117 is a portion of a proximity head 106 where other source inlets 302 and 306 in addition to other source outlets 304 may be utilized in addition to the orientation 117 shown. The orientation 117 may include a source inlet 306 on a leading edge 109 with a source outlet 304 in between the source inlet 306 and the source outlet 302 .
FIG. 6B shows another proximity head inlet/outlet orientation 119 that may be utilized to clean and dry the wafer 108 in accordance with one embodiment of the present invention. In one embodiment, the orientation 119 is a portion of a proximity head 106 where other source inlets 302 and 306 in addition to other source outlets 304 may be utilized in addition to the orientation 119 shown. The orientation 119 may include a source outlet 304 on a leading edge 109 with a source inlet 302 in between the source outlet 304 and the source inlet 306 .
FIG. 6C shows a further proximity head inlet/outlet orientation 121 that may be utilized to clean and dry the wafer 108 in accordance with one embodiment of the present invention. In one embodiment, the orientation 121 is a portion of a proximity head 106 where other source inlets 302 and 306 in addition to other source outlets 304 may be utilized in addition to the orientation 119 shown. The orientation 119 may include a source inlet 306 on a leading edge 109 with a source inlet 302 in between the source outlet 304 and the source outlet 306 .
FIG. 6D illustrates a preferable embodiment of a wafer drying process that may be conducted by a proximity head 106 in accordance with one embodiment of the present invention. Although FIG. 6 shows a top surface 108 a being dried, it should be appreciated that the wafer drying process may be accomplished in substantially the same way for the bottom surface 108 b of the wafer 108 . In one embodiment, a source inlet 302 may be utilized to apply isopropyl alcohol (IPA) vapor toward a top surface 108 a of the wafer 108 , and a source inlet 306 may be utilized to apply deionized water (DIW) toward the top surface 108 a of the wafer 108 . In addition, a source outlet 304 may be utilized to apply vacuum to a region in close proximity to the wafer surface to remove fluid or vapor that may located on or near the top surface 108 a . It should be appreciated that any suitable combination of source inlets and source outlets may be utilized as long as at least one combination exists where at least one of the source inlet 302 is adjacent to at least one of the source outlet 304 which is in turn adjacent to at least one of the source inlet 306 . The IPA may be in any suitable form such as, for example, IPA vapor where IPA in vapor form is inputted through use of a N 2 gas. Moreover, although DIW is utilized herein, any other suitable fluid may be utilized that may enable or enhance the wafer processing such as, for example, water purified in other ways, cleaning fluids, etc. In one embodiment, an IPA inflow 310 is provided through the source inlet 302 , a vacuum 312 may be applied through the source outlet 304 and DIW inflow 314 may be provided through the source inlet 306 . Therefore, an embodiment of the IPA-vacuum-DIW orientation as described above in reference to FIG. 2 is utilized. Consequently, if a fluid film resides on the wafer 108 , a first fluid pressure may be applied to the wafer surface by the IPA inflow 310 , a second fluid pressure may be applied to the wafer surface by the DIW inflow 314 , and a third fluid pressure may be applied by the vacuum 312 to remove the DIW, IPA and the fluid film on the wafer surface.
Therefore, in one embodiment, as the DIW inflow 314 and the IPA inflow 310 is applied toward a wafer surface, any fluid on the wafer surface is intermixed with the DIW inflow 314 . At this time, the DIW inflow 314 that is applied toward the wafer surface encounters the IPA inflow 310 . The IPA forms an interface 118 (also known as an IPA/DIW interface 118 ) with the DIW inflow 314 and along with the vacuum 312 assists in the removal of the DIW inflow 314 along with any other fluid from the surface of the wafer 108 . In one embodiment, the IPA/DIW interface 118 reduces the surface of tension of the DIW. In operation, the DIW is applied toward the wafer surface and almost immediately removed along with fluid on the wafer surface by the vacuum applied by the source outlet 304 . The DIW that is applied toward the wafer surface and for a moment resides in the region between a proximity head and the wafer surface along with any fluid on the wafer surface forms a meniscus 116 where the borders of the meniscus 116 are the IPA/DIW interfaces 118 . Therefore, the meniscus 116 is a constant flow of fluid being applied toward the surface and being removed at substantially the same time with any fluid on the wafer surface. The nearly immediate removal of the DIW from the wafer surface prevents the formation of fluid droplets on the region of the wafer surface being dried thereby reducing the possibility of contamination drying on the wafer 108 . The pressure (which is caused by the flow rate of the IPA) of the downward injection of IPA also helps contain the meniscus 116 .
The flow rate of the IPA assists in causing a shift or a push of water flow out of the region between the proximity head and the wafer surface and into the source outlets 304 through which the fluids may be outputted from the proximity head. Therefore, as the IPA and the DIW is pulled into the source outlets 304 , the boundary making up the IPA/DIW interface 118 is not a continuous boundary because gas (e.g., air) is being pulled into the source outlets 304 along with the fluids. In one embodiment, as the vacuum from the source outlet 304 pulls the DIW, IPA, and the fluid on the wafer surface, the flow into the source outlet 304 is discontinuous. This flow discontinuity is analogous to fluid and gas being pulled up through a straw when a vacuum is exerted on combination of fluid and gas. Consequently, as the proximity head 106 moves, the meniscus moves along with the proximity head, and the region previously occupied by the meniscus has been dried due to the movement of the IPA/DIW interface 118 . It should also be understood that the any suitable number of source inlets 302 , source outlets 304 and source inlets 306 may be utilized depending on the configuration of the apparatus and the meniscus size and shape desired. In another embodiment, the liquid flow rates and the vacuum flow rates are such that the total liquid flow into the vacuum outlet is continuous, so no gas flows into the vacuum outlet.
It should be appreciated any suitable flow rate may be utilized for the IPA, DIW, and vacuum as long as the meniscus 116 can be maintained. In one embodiment, the flow rate of the DIW through a set of the source inlets 306 is between about 25 ml per minute to about 3,000 ml per minute. In a preferable embodiment, the flow rate of the DIW through the set of the source inlets 306 is about 400 ml per minute. It should be understood that the flow rate of fluids may vary depending on the size of the proximity head. In one embodiment a larger head may have a greater rate of fluid flow than smaller proximity heads. This may occur because larger proximity heads, in one embodiment, have more source inlets 302 and 306 and source outlets 304 More flow for larger head.
In one embodiment, the flow rate of the IPA vapor through a set of the source inlets 302 is between about 1 standard cubic feet per minute (SCFM) to about 100 SCFM. In a preferable embodiment, the IPA flow rate is between about 10 and 40 SCFM.
In one embodiment, the flow rate for the vacuum through a set of the source outlets 304 is between about 10 standard cubic feet per hour (SCFH) to about 1250 SCFH. In a preferable embodiment, the flow rate for a vacuum though the set of the source outlets 304 is about 350 SCFH. In an exemplary embodiment, a flow meter may be utilized to measure the flow rate of the IPA, DIW, and the vacuum.
FIG. 6E shows another wafer drying process using another source inlet/outlet orientation that may be conducted by a proximity head 106 in accordance with one embodiment of the present invention. In this embodiment, the proximity head 106 may be moved over the top surface 108 a of the wafer 108 so the meniscus may be moved along the wafer surface 108 a . The meniscus applies fluid to the wafer surface and removes fluid from the wafer surface thereby cleaning and drying the wafer simultaneously. In this embodiment, the source inlet 306 applies a DIW flow 314 toward the wafer surface 108 a , the source inlet 302 applies IPA flow 310 toward the wafer surface 108 a , and the source outlet 312 removes fluid from the wafer surface 108 a . It should be appreciated that in this embodiment as well as other embodiments of the proximity head 106 described herein, additional numbers and types of source inlets and source outlets may be used in conjunction with the orientation of the source inlets 302 and 306 and the source outlets 304 shown in FIG. 6E . In addition, in this embodiment as well as other proximity head embodiments, by controlling the amount of flow of fluids onto the wafer surface 108 a and by controlling the vacuum applied, the meniscus may be managed and controlled in any suitable manner. For example, in one embodiment, by increasing the DIW flow 314 and/or decreasing the vacuum 312 , the outflow through the source outlet 304 may be nearly all DIW and the fluids being removed from the wafer surface 108 a . In another embodiment, by decreasing the DIW flow 314 and/or increasing the vacuum 312 , the outflow through the source outlet 304 may be substantially a combination of DIW and air as well as fluids being removed from the wafer surface 108 a.
FIG. 6F shows another source inlet and outlet orientation where an additional source outlet 307 may be utilized to input an additional fluid in accordance with one embodiment of the present invention. The orientation of inlets and outlets as shown in FIG. 6E is the orientation described in further detail in reference to FIG. 6D except the additional source outlet 307 is included adjacent to the source inlet 306 on a side opposite that of the source outlet 304 . In such an embodiment, DIW may be inputted through the source inlet 306 while a different solution such as, for example, a cleaning solution may be inputted through the source inlet 307 . Therefore, a cleaning solution flow 315 may be utilized to enhance cleaning of the wafer 108 while at substantially the same time drying the top surface 108 a of the wafer 108 .
FIG. 7A illustrates a proximity head 106 performing a drying operation in accordance with one embodiment of the present invention. The proximity head 106 , in one embodiment, moves while in close proximity to the top surface 108 a of the wafer 108 to conduct a cleaning and/or drying operation. It should be appreciated that the proximity head 106 may also be utilized to process (e.g., clean, dry, etc.) the bottom surface 108 b of the wafer 108 . In one embodiment, the wafer 108 is rotating so the proximity head 106 may be moved in a linear fashion along the head motion while fluid is removed from the top surface 108 a . By applying the IPA 310 through the source inlet 302 , the vacuum 312 through source outlet 304 , and the deionized water 314 through the source inlet 306 , the meniscus 116 as discussed in reference to FIG. 6 may be generated.
FIG. 7B shows a top view of a portion of a proximity head 106 in accordance with one embodiment of the present invention. In the top view of one embodiment, from left to right are a set of the source inlet 302 , a set of the source outlet 304 , a set of the source inlet 306 , a set of the source outlet 304 , and a set of the source inlet 302 . Therefore, as IPA and DIW are inputted into the region between the proximity head 106 and the wafer 108 , the vacuum removes the IPA and the DIW along with any fluid film that may reside on the wafer 108 . The source inlets 302 , the source inlets 306 , and the source outlets 304 described herein may also be any suitable type of geometry such as for example, circular opening, square opening, etc. In one embodiment, the source inlets 302 and 306 and the source outlets 304 have circular openings.
FIG. 7C illustrates a proximity head 106 with angled source inlets 302 ′ performing a drying operation in accordance with one embodiment of the present invention. It should be appreciated that the source inlets 302 ′ and 306 and the source outlet(s) 304 described herein may be angled in any suitable way to optimize the wafer cleaning and/or drying process. In one embodiment, the angled source inlets 302 ′ that input IPA vapor onto the wafer 108 is angled toward the source inlets 306 such that the IPA vapor flow is directed to contain the meniscus 116 .
FIG. 8A illustrates a side view of the proximity heads 106 a and 106 b for use in a dual wafer surface cleaning and drying system in accordance with one embodiment of the present invention. In this embodiment, by usage of source inlets 302 and 306 to input IPA and DIW respectively along with the source outlet 304 to provide a vacuum, the meniscus 116 may be generated. In addition, on the side of the source inlet 306 opposite that of the source inlet 302 , there may be a source outlet 304 to remove DIW and to keep the meniscus 116 intact. As discussed above, in one embodiment, the source inlets 302 and 306 may be utilized for IPA inflow 310 and DIW inflow 314 respectively while the source outlet 304 may be utilized to apply vacuum 312 . It should be appreciated that any suitable configuration of source inlets 302 , source outlets 304 and source inlets 306 may be utilized. For example, the proximity heads 106 a and 106 b may have a configuration of source inlets and source outlets like the configuration described above in reference to FIGS. 7A and 7B . In addition, in yet more embodiments, the proximity heads 106 a and 106 b may be of a configuration as shown below in reference to FIGS. 9 through 15 . Any suitable surface coming into contact with the meniscus 116 may be dried by the movement of the meniscus 116 into and away from the surface.
FIG. 8B shows the proximity heads 106 a and 106 b in a dual wafer surface cleaning and drying system in accordance with one embodiment of the present invention. In this embodiment, the proximity head 106 a processes the top surface 108 a of the wafer 108 , and the proximity head 106 b processes the bottom surface of 108 b of the wafer 108 . By the inputting of the IPA and the DIW by the source inlets 302 and 306 respectively, and by use of the vacuum from the source outlet 304 , the meniscus 116 may be formed between the proximity head 106 a and the wafer 108 and between the proximity head 106 b and the wafer 108 . The proximity heads 106 a and 106 b , and therefore the meniscus 116 , may be moved over the wet areas of the wafer surface in an manner so the entire wafer 108 can be dried.
FIGS. 9 through 15 illustrate exemplary embodiments of the proximity head 106 . As shown by the exemplary figures that follow, the proximity head may be any suitable configuration or size that may enable the fluid removal process as described in FIGS. 6 to 8 . Therefore, any, some, or all of the proximity heads described herein may be utilized in any suitable wafer cleaning and drying system such as, for example, the system 100 or a variant thereof as described in reference to FIGS. 2A to 2D . In addition, the proximity head may also have any suitable numbers or shapes of source outlets 304 and source inlets 302 and 306 . It should be appreciated that the side of the proximity heads shown from a top view is the side that comes into close proximity with the wafer to conduct wafer processing. All of the proximity heads described in FIGS. 9 through 15 enable usage of the IPA-vacuum-DIW orientation or a variant thereof as described above in reference to FIGS. 2 and 6 . In addition, the proximity heads described herein may be utilized for either cleaning or drying operations depending on the fluid that is inputted and outputted from the source inlets 302 and 306 , and the source outlets 304 . In addition, the proximity heads described herein may have multiple inlet lines and multiple outlet lines with the ability to control the relative flow rates of liquid and/or vapor and/or gas through the outlets and inlets. It should be appreciated that every group of source inlets and source outlets can have independent control of the flows.
It should be appreciated that the size as well as the locations of the source inlets and outlets may be varied as long as the meniscus produced is stable. In one embodiment, the size of the openings to source inlets 302 , source outlets 304 , and source inlets 306 are between about 0.02 inch and about 0.25 inch in diameter. In a preferable embodiment, the size of the openings of the source inlets 302 and the source outlets 304 is about 0.03 inch, and the size of the openings of the source inlets 306 is about 0.06 inch.
In one embodiment the source inlets 302 and 306 in addition to the source outlets 304 are spaced about 0.03 inch and about 0.5 inch apart. In a preferable embodiment, the source inlets 306 are spaced 0.125 inch apart from each other and the source outlets 304 are spaced 0.03 inch apart and the source inlets 302 are spaced about 0.03 inch apart.
FIG. 9A shows a top view of a proximity head 106 - 1 with a circular shape in accordance with one embodiment of the present invention. In this embodiment, the proximity head 106 - 1 includes three of the source inlets 302 which, in one embodiment, applies IPA to a surface of the wafer 108 . The proximity head 106 - 1 also includes three of the source outlets 304 in a center portion of the head 106 - 1 . In one embodiment, one of the source inlets 306 is located adjacent to the source inlets 302 and the source outlets 304 . In this embodiment, another one the source inlets 306 is located on the other side of the source outlets 304 .
In this embodiment, the proximity head 106 - 1 shows that the three source outlets 304 are located in the center portion and is located within an indentation in the top surface of the proximity head 106 - 1 . In addition, the source inlets 302 are located on a different level than the source inlets 306 . The side of the proximity head 106 - 1 is the side that comes into close proximity with the wafer 108 for cleaning and/or drying operations.
FIG. 9B shows a side view of the proximity head 106 - 1 with a circular shape in accordance with one embodiment of the present invention. The proximity head 106 - 1 has inputs at a bottom portion 343 which lead to the source inlets 302 and 306 and the source outlets 304 as discussed in further detail in reference to FIG. 9C . In one embodiment, a top portion 341 of the proximity head 106 - 1 is smaller in circumference than the bottom portion 343 . As indicated previously, it should be appreciated that the proximity head 106 - 1 as well as the other proximity heads described herein may have any suitable shape and/or configuration.
FIG. 9C illustrates a bottom view of the proximity head 106 - 1 with a circular shape in accordance with one embodiment of the present invention. The proximity head 106 - 1 also includes ports 342 a , 342 b, and 342 c that, in one embodiment, correspond to the source inlet 302 , source outlet 304 , and source inlet 306 respectively. By inputting or removing fluid through the ports 342 a, 342 b, and 342 c, fluids may be inputted or outputted through the source inlet 302 , the source outlet 304 , and the source inlet 306 as discussed in reference to FIG. 9A .
It should be appreciated that the ports 342 a, 342 b, and 342 c for any of the proximity heads described herein may be any suitable orientation and dimension as long as a stable meniscus can be generated and maintained by the source inlets 302 , source outlets 304 , and source inlets 306 . The embodiments of the ports 342 a, 342 b, and 342 c described herein may be applicable to any of the proximity heads described herein. In one embodiment, the port size of the ports 342 a, 342 b, and 342 c may be between about 0.03 inch and about 0.25 inch in diameter. In a preferable embodiment, the port size is about 0.06 inch to 0.18 inch in diameter. In one embodiment, the distance between the ports is between about 0.125 inch and about 1 inch apart. In a preferable embodiment, the distance between the ports is between about 0.25 inch and about 0.37 inch apart.
FIG. 10A shows a proximity head 106 - 2 with an elongated ellipse shape in accordance with one embodiment of the present invention. The proximity head 106 - 2 includes the source inlets 302 , source outlets 304 , and source inlets 306 . In this embodiment, the source inlets 302 are capable of applying IPA toward a wafer surface region, the source inlets 306 are capable of applying DIW toward the wafer surface region, and the source outlets 304 are capable of applying vacuum to a region in close proximity of a surface of the wafer 108 . By the application of the vacuum, the IPA, DIW, and any other type of fluids that may reside on a wafer surface may be removed.
The proximity head 106 - 2 also includes ports 342 a, 342 b, and 342 c that, in one embodiment, correspond to the source inlet 302 , source outlet 304 , and source inlet 306 respectively. By inputting or removing fluid through the ports 342 a, 342 b, and 342 c, fluids may be inputted or outputted through the source inlet 302 , the source outlet 304 , and the source inlet 306 . Although the ports 342 a, 342 b, and 342 c correspond with the source inlet 302 , the source outlet 304 , and the source inlet 306 in this exemplary embodiment, it should be appreciated that the ports 342 a, 342 b, and 342 c may supply or remove fluid from any suitable source inlet or source outlet depending on the configuration desired. Because of the configuration of the source inlets 302 and 306 with the source outlets 304 , the meniscus 116 may be formed between the proximity head 106 - 2 and the wafer 108 . The shape of the meniscus 116 may vary depending on the configuration and dimensions of the proximity head 106 - 2 .
FIG. 10B shows a top view of the proximity head 106 - 2 with an elongated ellipse shape in accordance with one embodiment of the present invention. In FIG. 10B , the pattern of the source outlets 304 and the source inlets 302 and 306 is indicated. Therefore, in one embodiment, the proximity head 106 - 2 includes the source inlets 302 located outside of the source outlets 304 which are in turn located outside of the source inlets 306 . Therefore, the source inlets 302 substantially surround the source outlets 304 which in turn substantially surround the source inlets 306 to enable the IPA-vacuum-DIW orientation. In one embodiment, the source inlets 306 are located down the middle of the long axis of the of the proximity head 106 - 2 . In such an embodiment, the source inlets 302 and 306 input IPA and DIW respectively to a region of the wafer 108 that is being dried and/or cleaned. The source outlets 304 in this embodiment exert vacuum in close proximity of the region of the wafer 108 being dried thereby outputting the IPA and the DIW from the source inlets 302 and 306 as well as other fluids from the region of the wafer 108 that is being dried. Therefore, in one embodiment, a drying/cleaning action as discussed in reference to FIG. 6 may occur to clean/dry the wafer 108 in an extremely effective manner.
FIG. 10C shows a side view of the proximity head 106 - 2 with an elongated ellipse shape in accordance with one embodiment of the present invention. It should be appreciated that the proximity head 106 - 2 is exemplary in nature and may be any suitable dimension as long as the source inlets 302 and 306 as well as the source outlet 304 are configured in a manner to enable cleaning and/or drying of the wafer 108 in the manner described herein.
FIG. 11A shows a top view of a proximity head 106 - 3 with a rectangular shape in accordance with one embodiment of the present invention. In this embodiment, as shown in FIG. 1A , the proximity head 106 - 3 includes two rows of the source inlets 302 at the top of the figure, the source outlets 304 in a row below the source inlets 302 , a row of source inlets 306 below the source outlets 304 , and a row of the source outlets 304 below the source inlets 306 . In one embodiment, IPA and DIW may be inputted to the region of the wafer 108 that is being dried through the source inlets 302 and 306 respectively. The source outlets 304 may be utilized to pull away fluids from the surface of the wafer 108 such as the IPA and the DIW in addition to other fluids on the surface of the wafer 108 .
FIG. 11B shows a side view of the proximity head 106 - 3 with a rectangular 106 - 3 includes ports 342 a, 342 b, and 342 c which, in one embodiment, may be utilized to input and/or output fluids through the source inlets 302 and 306 as well as the source outlets 304 . It should be appreciated that any suitable number of ports 342 a, 342 b, and 342 c may be utilized in any of the proximity heads described herein depending on the configuration and the source inlets and outlets desired.
FIG. 11C illustrates a bottom portion of the proximity head 106 - 3 in a rectangular shape in accordance with one embodiment of the present invention. The proximity head 106 - 3 includes ports 342 a, 342 b, and 342 c on a back portion while connecting holes 340 on the bottom portion may be utilized to attach the proximity head 106 - 3 to the top arm 104 a as discussed above in reference to FIGS. 2A through 2D .
FIG. 12A shows a proximity head 106 - 4 with a partial rectangular and partial circular shape in accordance with one embodiment of the present invention. In this embodiment, the proximity head 106 - 4 includes one row of source inlets 306 that is adjacent on both sides to rows of source outlets 304 . One of the rows of source outlets 304 is adjacent to two rows of source inlets 302 . Perpendicular to and at the ends of the rows described above are rows of source outlets 304 .
FIG. 12B shows a rear view of the proximity head 106 - 4 with a partial rectangular and partial circular shape in accordance with one embodiment of the present invention. In one embodiment, the proximity head 106 - 4 includes ports 342 a, 342 b, and 342 c on a back side as shown by the rear view where the back side is the square end of the proximity head 106 - 4 . The ports 342 a, 342 b, and 342 c may be utilized to input and/or output fluids through the source inlets 302 and 306 and the source outlets 304 . In one embodiment, the ports 342 a, 342 b, and 342 c correspond to the source inlets 302 , the source outlets 304 , and the source inlets 306 respectively.
FIG. 12C shows a top view of the proximity head 106 - 4 with a partial rectangular and partial circular shape in accordance with one embodiment of the present invention. As shown this view, the proximity head 106 - 4 includes a configuration of source inlets 302 and 306 , and source outlets 304 which enable the usage of the IPA-vacuum-DIW orientation.
FIG. 13A illustrates a top view of a proximity head 106 - 5 with a circular shape similar to the proximity head 106 - 1 shown in FIG. 9A in accordance with one embodiment of the present invention. In this embodiment, the pattern of source inlets and source outlets is the same as the proximity head 106 - 1 , but as shown in FIG. 13B , the proximity head 106 - 5 includes connecting holes 340 where the proximity head 106 - 5 can be connected with an apparatus which can move the proximity head close to the wafer.
FIG. 13B shows the proximity head 106 - 5 from a bottom view in accordance with one embodiment of the present invention. From the bottom view, the proximity head 106 - 5 has the connecting holes 340 in various locations on a bottom end. The bottom end may be connected to either the upper arm 106 a or the bottom arm 106 b if the proximity head 106 - 5 is utilized in the system 100 as shown above in reference to FIGS. 2A through 2D . It should be appreciated that the proximity head 106 - 5 may have any suitable number or type of connecting holes as long as the proximity head 106 - 5 may be secured to any suitable apparatus that can move the proximity head 106 - 5 as discussed above in reference to FIGS. 2A through 2D .
FIG. 13C illustrates the proximity head 106 - 5 from a side view in accordance with one embodiment of the present invention. The proximity head 106 - 5 has a side that is a larger circumference than the side that moves into close proximity with the wafer 108 . It should be appreciated although the circumference of the proximity head 106 - 5 (as well as the other embodiments of the proximity head 106 that is described herein) may be any suitable size and may be varied depending on how much surface of the wafer 108 is desired to be processed at any given time.
FIG. 14A shows a proximity head 106 - 6 where one end is squared off while the other end is rounded in accordance with one embodiment of the present invention. In this embodiment, the proximity head 106 - 6 has a pattern of the source inlets 302 and 306 as well as the source outlets 304 similar to the pattern as shown in the proximity head 106 - 4 described in reference to FIG. 12A except there are additional rows of source inlets 302 as can be seen from the top view of FIG. 14B .
FIG. 14B illustrates a top view of the proximity head 106 - 6 where one end is squared off while the other end is rounded in accordance with one embodiment of the present invention. In one embodiment, the proximity head 106 - 6 includes a dual tiered surface with the configuration of source inlets 302 and 306 and source outlets 304 that enables the ability to apply the IPA-vacuum-DIW orientation during wafer processing.
FIG. 14C shows a side view of a square end of the proximity head 106 - 6 in accordance with one embodiment of the present invention. In this embodiment, the proximity head 106 - 6 includes the ports 342 a, 342 b, and 342 c which enables input and output of fluid both to and from the source inlets 302 and 306 as well as the source outlets 304 .
FIG. 15A shows a bottom view of a 25 holes proximity head 106 - 7 in accordance with one embodiment of the present invention. In this embodiment, the proximity head 106 - 7 includes 25 openings any of which may be utilized as ports 342 a, 342 b, and 342 c depending on the configuration desired. In one embodiment, seven openings are the ports 342 a, six openings are the source outlets 342 b, and three openings are ports 342 c . In this embodiment, the other nine openings are left unused. It should be appreciated that the other holes may be used as ports 342 a, 342 b, and/or 342 c depending on the configuration and type of function desired of the proximity head 106 - 7 .
FIG. 15B shows a top view of the 25 holes proximity head 106 - 7 in accordance with one embodiment of the present invention. The side of the proximity head 106 - 7 shown by FIG. 15B is the side that comes into close proximity with the wafer 108 to conduct drying and/or cleaning operations on the wafer 108 . The proximity head 106 - 7 includes an IPA input region 382 , a vacuum outlet regions 384 , and a DIW input region 386 in a center portion of the proximity head 106 - 7 . In one embodiment, the IPA input region 382 includes a set of the source inlets 302 , the vacuum outlet regions 384 each include a set of the source outlets 304 , and the DIW input region 386 includes a set of the source inlets 306 .
Therefore, in one embodiment when the proximity head 106 - 7 is in operation, a plurality of the source inlet 302 inputs IPA into the IPA input region, a plurality of the source outlet 304 generates a negative pressure (e.g., vacuum) in the vacuum outlet regions 384 , and a plurality of the source inlet 306 inputs DIW into the DIW input region 386 . In this way, the IPA-vacuum-DIW orientation may be utilized to intelligently dry a wafer.
FIG. 15C shows a side view of the 25 holes proximity head 106 - 7 in accordance with one embodiment of the present invention. As shown in this view, a top surface of the proximity head 106 - 7 has a dual level surface. In one embodiment, the level with the plurality of the source inlet 302 is below the level with the plurality of the source outlet 304 and the plurality of the source inlet 306 .
While this invention has been described in terms of several preferred embodiments, it will be appreciated that those skilled in the art upon reading the preceding specifications and studying the drawings will realize various alterations, additions, permutations and equivalents thereof. It is therefore intended that the present invention includes all such alterations, additions, permutations, and equivalents as fall within the true spirit and scope of the invention. | 4y
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DESCRIPTION
The present invention relates to a new synthesis of vincaminic acid derivatives, in particular of vincamine, apovincamine and deoxyvincamine and of the ethyl esters of vincaminic acid, apovincaminic acid and deoxyvincaminic acid, in the form of racemates and enantiomers.
Several syntheses of vincamine have already been described in the literature; these are either partial syntheses starting from natural alkaloids (for example from tabersonine, French Pat. No. 71/47,731), or total syntheses (French Pat. No. 70/11,406 and U.S. Pat. No. 3,454,583).
Vincamine is known for its valuable pharmacological properties as a cerebral oxygenating agent and cerebral vasoregulator and for its therapeutic activity for the treatment of cerebral insufficiencies.
The synthesis of the invention is carried out starting from 1-ethyl-2,3,4,6,7,12-hexahydroindolo[2,3-a]quinolizine, ##STR2## this product being described by WENKERT and WICKBERG (J.Am.Chem.Soc. 87, 1,580 (1965)).
Scheme (1) for the synthesis of vincamine and scheme (2) for the synthesis of deoxyvincamine and apovincamine are shown on the following pages. ##STR3##
To prepare vincamine according to the invention, the enamine (1) is reacted with the (2,4-dinitrophenyl)-hydrazone of methyl or ethyl bromopyruvate (2), and then either the protective group is removed from the compound (3) in order to obtain the cyclised compound (4), which is reduced in order to obtain the cyclised compound (6), or the compound (3) is reduced in order to obtain the compound (5), from which the protective group is removed in order to obtain the cyclised compound (6), and, if appropriate, the compound (6) is transesterified (if it is the ethyl ester) to give (±)-vincamine (7).
The first step can be carried out in a solvent, such as ethyl acetate, at ambient temperature. The removal of the protective group from the compound (3) to give the compound (4) can be carried out in a solvent such as a mixture of acetonitrile and water, adjusted to a suitable pH, e.g. about pH 8, using preferably sodium borate and hydrochloric acid. Ambient temperature can be used in this step also.
The reduction of the compound (4) can be carried out by any suitable means, such as zinc in the presence of 50% strength acetic acid or Raney nickel in 50% strength acetic acid.
The reduction of the compound (3) to give the compound (5) can be carried out, for example, by means of an alkali metal hydride in an acid medium in a solvent, such as methanol or acetronitrile, or a mixture thereof.
The removal of the protective group from the compound (5) is carried out by means of titanium (III) chloride in a solvent, such as methanol or acetonitrile, containing formaldehyde and an acid, such as hydrochloric acid or acetic acid, in a temperature range of 20° to 140° C.
If appropriate, the transesterification of the compound (6) to give (±)-vincamine (7) is carried out by heating in methanol at the reflux temperature, in the presence of sodium methylate.
The cis-vincamine obtained according to the synthesis of the invention is in the (±) racemic form. The compound (5) is obtained directly in the cis form, starting from the compound (3), in a proportion of at least 80%.
The compound (6) is a mixture of the two epimers on the carbon in the 14-position, the H-atom in the 3-position and the ethyl in the 16-position being in the cis position, relative to each other.
To prepare apovincamine and deoxyvincamine according to the invention, the enamine (1) is reacted with the (2,4-dinitrophenyl)-hydrazone of ethyl or methyl bromopyruvate (2), and the compound (3) is then reduced to give the compound (5), which is reacted, in formic acid, either with an approx. 15% aqueous solution of titanium (III) chloride in order to obtain ethyl apovincaminate (8,R═C 2 H 5 ) or apovincamine (8,R═CH 3 ), or with an approx. 30% aqueous solution of titanium (III) chloride in order to obtain ethyl deoxyvincaminate (9, R═C 2 H 5 ) or deoxyvincamine (9, R═CH 3 ). The strengths of the solutions are weight/volume.
The vincamine obtained in accordance with reaction scheme 1 is cis-vincamine in the (±) racemic form. Now, the Applicant Company has succeeded in resolving the compound (5) (itself also in the racemic form) in order to obtain the dextrorotatory and laevorotatory enantiomers and to lead directly, starting from this compound, to optically active vincaminic acid derivatives, especially cis-(+)-vincamine and cis-(-)-vincamine.
According to the invention, the resolution of the compound (5) is carried out using an optically active acid, such as dibenzoyl-L-tartaric acid, in a solvent, such as acetonitrile.
The following examples illustrate the invention.
The analyses and the IR and NMR spectra confirmed the structure of the compounds.
The starting compound (2) is new. If R is C 2 H 5 , it is obtained in the following manner:
39 g (0.2 mol) of ethyl bromopyruvate are added to 41 g (0.2 mol) of (2,4-dinitrophenyl)-hydrazine in an acid, such as hydrochloric or acetic acid. The temperature is allowed to return to 20° C. and the precipitate formed is filtered off, washed copiously with water and then dried in vacuo at 60° C.
60 g of ethyl [2-(2,4-dinitrophenyl)-hydrazono-3-bromopyruvate] are obtained.
Melting point=150.5° C.
Methyl [2-(2,4-dinitrophenyl)-hydrazono-3bromopyruvate] is prepared in the same manner.
Melting point=158° C.
EXAMPLE 1
(±)-Vincamine (Scheme 1. R═C 2 H 5 ).
1. 1-[2-(2,4-Dinitrophenyl)-hydrazono-2-ethoxycarbonylethyl]-1-ethyl-1,2,3,4,6,7-hexahydro-(12H)-indolo[2,3-a]-quinolizin-5-ium bromide (compound 3)
29 g (77.35 mmols) of the starting compound (2) are dissolved in 1.7 liters of ethyl acetate. 8.95 g (88.6 mmols) of triethylamine, dried over KOH, are added to the solution, whilst stirring, and a solution of 15.7 g (62.4 mmols) of the enamine (1) in 500 ml of ethyl acetate is then added. The reaction mixture is stirred at ambient temperature overnight. The precipitate formed is filtered off and washed with ethyl acetate. The resulting product is dried in vacuo at 40° C. This yields 39 g (yield 99.6%) of an orange powder which melts at 200° C. with decomposition.
2. Ethyl dehydrovincaminate chloride (compound 4)
1.56 g (2.48 mmols) of the compound (3) obtained above are dissolved in 50 ml of acetonitrile. 150 ml of water are added and 50 ml of a buffer at pH 8, consisting of a concentrated solution of sodium borate and hydrochloric acid, are then added. The reaction mixture is stirred overnight. The small amount of precipitate formed is filtered off. The aqueous phase is washed three times with 50 ml of toluene and extracted with methylene chloride. The organic phase is dried over sodium sulphate and filtered and the filtrate is concentrated. This yields 1 g (yield 100%) of the compound (4), which is used as such for the following step.
3. (±)-Vincamine
1 g (2.48 mmols) of the compound (4) obtained above is dissolved in 65 ml of 50% strength acetic acid. The solution is heated to 88° C. in the course of 4 minutes and 5 g of zinc are then added in small amounts. Heating is maintained for 5 minutes. The reaction mixture is poured onto 65 g of ice and treated with 50 ml of 28% strength ammonia solution. The precipitate is filtered off and dried in vacuo at 60° C. This yields 0.55 g of the compound (6), which is taken up in 3 ml of methanol. The mixture is heated at the reflux temperature, in the presence of sodium methylate (0.1 ml of a 30% strength solution in methanol), for 5 hours. This yields 0.33 g (yield 38%) of (±)-vincamine.
EXAMPLE 2
(±)-Vincamine (Scheme 1. R═C 2 H 5 ).
1. The compound (3) is prepared as in Example 1
2. 1-[2-(2,4-Dinitrophenyl)-hydrazono-2-ethoxycarbonylethyl]-1-ethyl-1,2,3,4,6,7,12,12b-octahydroindolo[2,3a]-quinolizine
10.5 g (167 mmols) of NaBH 3 CN are added, whilst stirring, to a solution of 35 g of the compound (3) in 40 ml of acetic acid, 200 ml of methanol, 200 ml of acetonitrile and 200 ml of water. After one hour at ambient temperature, the solution is treated with 80 ml of 28% strength ammonia solution and 200 ml of water. The aqueous phase is extracted with methylene chloride. The organic phases are concentrated and the residue is taken up in 150 ml of methanol. The mixture is heated at the reflux temperature for 15 minutes, left to cool and filtered.
This yields 24.57 g (yield 80%) of compound (5) melting at 214° C.
3. Ethyl (±)-vincaminate
1 g (1.82 mmols) of the compound (5) obtained above is dissolved in 20 ml of acetone and 10 ml of acetic acid. The solution is degassed with argon and added, in the course of 2 minutes, to a solution, kept at 67° C., containing 30 ml of a 15% strength solution of titanium chloride in water, 30 ml of a 37% strength solution of formaldehyde in degassed water, and 10 ml of degassed acetic acid.
After a reaction time of 20 minutes at 67° C., 200 ml of iced water are added to the reaction mixture and the resulting mixture is extracted with methylene chloride. The combined organic phases are concentrated. The residue is taken up in 30 ml of iced water. The resulting solution is treated with 28% strength ammonia solution. The mixture is filtered and the precipitate is dried at 60° C. in vacuo. This yields 0.460 g (68%) of a mixture of epimers (in the 14-position) of the compound (6).
4. (±)-Vincamine
A solution of the compound (6) in methanol is heated at the reflux temperature for 5 hours in the presence of sodium methylate. This yields 0.326 g of (±)-vincamine.
Spectrographic analysis
NMR: (CDCl 3 , DMSO): 0.95 (t,3H), 1.40 (m,6H), 2.60 (m,3H), 3.30 (m,2H), 3.78 (s,3H), 3.86 (broad s, 1H), 7.07 (m,3H), 7.36 (m,1H).
IR: (KBr,cm -1 ): 3,440 (OH, broad), 2.920 (m), 2,840 (sh), 1,730 (COOMe).
EXAMPLE 3
(±)-Vincamine (Scheme 1. R═CH 3 )
1. A solution containing 6.88 g (27 mM) of enamine and 2.9 g (29 mM) of triethylamine in 60 ml of ethyl acetate is added to a suspension of 10 g (29 mM) of the (2,4-dinitrophenyl)-hydrazone of methyl bromopyruvate in 140 ml of ethyl acetate. The mixture is stirred for 16 hours and filtered and the product is washed with ethyl acetate. It is dried in vacuo at 70° C. This yields 15.2 g of 1-[2-(2,4-dinitrophenyl)-hydrazono-2-methoxycarbonylethyl]-1-ethyl-1,2,3,4,6,7-hexahydro-(12H)-indolo[2,3-a]quinolizin-5-ium bromide. (Yield: 92%).
Melting point=205° C. (decomposition).
2. 4.9 g (7.98 mM) of the latter compound are reduced with 1.29 g (24 mM) of potassium borohydride in order to obtain 1-[2-(2,4-dinitrophenyl)-hydrazono-2-methoxycarbonylethyl]-1-ethyl-1,2,3,4,6,7,12,12b-octahydroindolo[2,3-a]quinolizine (3.6 g; yield: 74%).
Melting point=205°-206° C.
3. 2 g (2.74 mM) of the product obtained above, in 28 ml of acetone, are added to a solution, at 55°-60° C., containing 60 ml of acetone, 10 ml of a 37% strength aqueous solution of formaldehyde, 20 ml of acetic acid and 60 ml of titanium (III) chloride solution (15% strength). The reaction is kept at 60° C. for 15 minutes and ice is then added. 5 g (72 mM) of NaNO 2 are added and nitrogen is bubbled for 15 minutes. Extraction is carried out with methylene chloride, the organic phase is concentrated and the residue is taken up in 10 ml of water. The solution is rendered basic with ammonia and filtered and the (±)-vincamine is dried (0.974 g; yield: 74%).
Melting point=242° C. (MeOH).
EXAMPLE 4
Ethyl (±)-apovincaminate
1. 1-[2-(2,4-Dinitrophenyl)-hydrazono-2-ethoxycarbonylethyl]-1-ethyl-1,2,3,4,6,7-hexahydro-(12H)-indolo]2,3-a]-quinolizin-5-ium bromide (compound 3)
29 g (77.35 mmols) of the starting compound (2) are dissolved in 1.7 liters of ethyl acetate. 8.95 g (88.6 mmols) of triethylamine, dried over KOH, are added to the solution, whilst stirring, and a solution of 15.7 g (62.4 mmols) of the enamine (1) in 500 ml of ethyl acetate is then added. The reaction mixture is stirred at ambient temperature overnight. The precipitate formed is filtered off and washed with ethyl acetate. The resulting product is dried in vacuo at 40° C. This yields 39 g (yield 99.6%) of an orange powder which melts at 200° C. with decomposition.
2. (±)-1-[2-(2,4-Dinitrophenyl)-hydrazono-2-ethoxycarbonylethyl]-1-ethyl-1,2,3,4,6,7,12,12b-octahydroindolo]2,3-a]quinolizine
10.5 g (167 mmols) of NaBH 3 CN are added, whilst stirring, to a solution of 35 g of compound (3) in 40 ml of acetic acid, 200 ml of methanol, 200 ml of acetonitrile and 200 ml of water. After one hour at ambient temperature, the solution is treated with 80 ml of 28% strength ammonia solution and 200 ml of water. The aqueous phase is extracted with methylene chloride. The organic phases are concentrated and the residue is then taken up in 150 ml of methanol. The mixture is heated at the reflux temperature for 15 minutes, left to cool and filtered.
This yields 24.57 g (yield 80%) of compound (5) melting at 214° C.
3. Ethyl (±)-apovincaminate
2.5 g (4.5 mmols) of the compound obtained above, in 75 ml of formic acid, are heated to the reflux temperature and 60 ml of 15% strength solution of titanium (III) chloride are added. The reaction mixture is heated for 20 minutes under reflux and ice is then added. The titanium dioxide is removed by filtration and the product is extracted with methylene chloride. The organic phases are washed with ammonia solution and then with water and are then dried over sodium sulphate. The solvent is removed and the solid residue is recrystallised from petroleum ether. This yields 1.24 g of ethyl apovincaminate in the form of a pale yellow solid.
Melting point=122° C.
(±)-Apovincamine can be prepared in the same manner starting from the compound (3) obtained from methyl bromopyruvate and the enamine (1).
EXAMPLE 5
Ethyl (±)-deoxyvincaminate
A solution of 5 g (9 mmols) of the compound obtained in Example 4, paragraph 1, in 150 ml of formic acid is heated to the reflux temperature and 125 ml of a 30% strength solution of titanium (III) chloride are added. Reflux is maintained for 20 minutes. Ice is added to the reaction mixture and the precipitate of titanium dioxide is removed by filtration. The product is extracted from the filtrate with methylene chloride and the organic phase is washed with ammonia solution and water. After drying over sodium sulphate and removing the solvent, a viscous oil (3.2 g) is obtained, which consists solely of a mixture of the two C 14 epimers of ethyl deoxyvincaminate (spectral and chromatographic data are in agreement) (yield: 100%).
(±)-Deoxyvincamine can be prepared in the same manner starting from methyl bromopyruvate and the enamine (1).
EXAMPLE 6
(+)-Vincamine and (-)-Vincamine
1. (+)-1β-[2-(2,4-Dinitrophenyl)-hydrazono-2-methoxycarbonylethyl]-1.alpha.-ethyl-1,2,3,4,6,7,12,12bα-octahydroindolo[2,3-a]quinolizine and (-)-1α-[2-(2,4-dinitrophenyl)-hydrazono-2-methoxycarbonylethyl]-1.beta.-ethyl-1,2,3,4,6,7,12,12bβ-octahydroindolo[2,3-a]quinolizine
100 ml (0.0187 mM) of the compound (5) and 70 mg of dibenzoyl-L-tartaric acid in 3 ml of CH 3 CN are heated to the reflux temperature. After cooling, the crystals formed are filtered off and washed with acetonitrile (1 ml). The filtrate is concentrated, the residue is treated with dilute ammonia solution and the mixture is extracted with methylene chloride. The organic phases are washed with water, dried over Na 2 SO 4 and concentrated. The residue is taken up in 2 ml of acetonitrile. The solution is left to crystallise for 24 hours and the crystals formed are filtered off. These crystals consist of 46 mg of the laevorotatory enantiomer of the compound (5), of optical rotation [α] D 20 =-77.9° (c=0.1; AcOH).
Melting point=196°-197° C.
The filtrate is concentrated and the residue is crystallised from 3 ml of MeOH. This yields 36 mg of the dextrorotatory enantiomer of the compound (5), of optical rotation [α] D 20 =+77.9° (c=0.1; AcOH).
Melting point=195°-197° C.
2. (+)-Vincamine
6 ml of 37% strength formaldehyde solution and 5 ml of titanium (III) chloride solution (15% strength) are introduced into a round-bottomed flask. The mixture is heated to 60° C. A solution of 310 mg of the (+)-enantiomer of the compound (5) in 2 ml of acetone and 2 ml of acetic acid is added. The mixture is left to react for 30 minutes at 55°-60° C. It is treated with NaNO 2 . A stream of argon is passed through for 3 minutes. Extraction is carried out several times with methylene chloride. The extracts are concentrated and the residue is taken up in ice and an ammoniacal solution. The mixture is filtered and the product is recrystallised from methanol in the presence of sodium methylate. This yields (+)-vincamine which melts at 227°-230° C.
[α] D 20 =-41° (c=1; pyridine).
3. (-)-Vincamine
The laevorotatory enantiomer of the compound (5) is reacted under the same conditions as in paragraph 2 and this yields (-)-vincamine.
Melting point=228°-230° C.
[α] D 20 =-41.4° (c=1; pyridine). | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional of Serial Number 634,478, filed Nov. 24, 1975, now U.S. Pat. No. 4045597 which in turn is a C-i-p of Serial Number 230,867 filed Mar. 1, 1972, now abandoned.
BACKGROUND OF THE INVENTION
The present invention relates to filamentary reinforced composites, used in applications requiring high strength and/or high modulus of elasticity materials, particularly for high temperature service, and more particularly to boron reinforced composites.
For some 20 years, there has been intensive development of composites with reinforcements utilizing the high strength and high modulus of elemental boron and to a lesser extent the compound system boron carbide, in the form of filaments made by chemical vapor deposition of the reinforcing material on a substrate. The substrate has been primarily selected from refractory metals, and more particularly tungsten. However, cost and weight penalties of tungsten have compelled considerable effort towards provision of a feasible substitute of lesser density and cost, consistent with the necessary conductivity and strength properties. Carbon monofilaments have been found particularly suitable for this purpose but have not afforded sufficient reliability in production to displace tungsten yet.
One approach is substantially given in U.S. Pat. No. 3,679,475 and references therein cited and in my above cited co-pending application and references therein cited.
It is an important object of the invention to provide filamentary reinforcements comprising boron or boron carbide coating on the carbon substrate which is reliably produceable in long lengths.
It is a further object of the invention to enable coating of such carbon substrates without breakage, particularly with boron layers of at least one mil thick and preferably thicker.
SUMMARY OF THE INVENTION
In the preferred embodiment, a carbon filament of about one mil diameter is treated by flash coating a very thin layer-- no greater than 2.5 microns thick and preferably substantially less--of boron thereon and subsequently heat treating the flash coated carbon product at 2,200°-2,800° C., preferably 2,500° C. for about two seconds or less, preferably about one second to produce an oriented graphite skin coating by catalytic means. The procedure for producing the flash coating and skin layer may be repeated one or more times. Subsequently, a deposit of boron is applied on the so-treated substrate in conventional fashion, or in accordance with the state of the art advances described in my said co-pending application.
It has been discovered that the resultant filaments are less vulnerable to breakage when being coated and can be coated more reliably in longer lengths than in prior art products. The reasons for this advance are not entirely understood, but are believed to comprise, possibly among others, the observable elimination of debris and tars from the substrate which could adversely effect the quality of high strength, high modulus coating material deposited thereon and the development of a skin layer of the carbon substrate which is catalytically converted by the presence of a suitably thin layer of boron to a highly oriented graphitic layer.
This procedure also makes possible a more rapid formation of the oriented graphite skin layer, resulting in a more economic product.
Other objects, features and advantages of the invention will be apparent from the following detail description of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Often filament substrates are provided as a product of coal tar pitch produced in accordance with U.S. Pat. No. 3,595,946, granted July 27, 1971 to Joo et al and the improvements thereof described in my co-pending application, entitled "A Carbon Filament Coated with Boron and Method of Making Same", Ser. No. 230,867, filed Mar. 1, 1972, the disclosure and references cited in said patent and application, the disclosures of all of which are incorporated herein by reference as though set out at length herein.
The substrate is passed through a tubular reactor and heated either by passage of electrical current therethrough, or indirectly, to a temperature of 1,100°-1,400° C., and preferably 1,300° C., and an atmosphere of boron trichloride vapor and hydrogen is maintained therein, flowing either co-current or counter current to the direction of movement of the substrate filament which rapidly passes through the reactor with the result that the hot substrate is exposed to the gaseous environment of the reactor for a short period of time to produce a layer of boron essentially uniformly on the substrate in a thickness of about 0.1-2.5 microns. This process is called chemical vapor deposition, and, at times, pyrolitic deposition.
With or without an intermediate step of cooling to room temperature, the flash-coated carbon filament is brought up to a temperature of about 2,500° C. and passed through a reactor containing an inert environment provided by argon or other inert gas flushing, for a period of about a second. The latter step results in a conductivity rise of at least two times for the flash-coated carbon filament. A skin layer of oriented graphite is produced.
Subsequently, the so-treated carbon filament is passed through a further reactor for chemical vapor deposition of boron in some conventional way, for example, as described in my said application Ser. No. 230,867, first cited above, or U.S. Pat. No. 3,679,475.
The resultant product contains three separate and distinct zones--the amorphous carbon core, the intermediate graphite skin layer, produced by catalytic conversion, and the outer boron coating.
It was found in actual practice of the above described embodiment, and variations of such practice, that the boron catalyst was essential for forming the oriented graphite layer under the time and temperature conditions described above and that the layer would not form without the boron. With the boron catalyst, repeated deposition runs were enabled in which final boron coat layers more than one mil thick could be coated without catastrophic breakage of the carbon substrate. This breakage normally would occur without the boron flash coating and heat treatment as a result of growth strains imposed on the substrate by the final boron coat growth phenomenon. It was also observed that there was lesser tendency with the boron catalyst than without for carbonaceous debris to occur at the entrance of the boron coating reactor. Such debris when it would occur would tend to cause serious flaws in short run lengths in the product.
The following characteristics of treated and non-treated carbon monofilament have been observed. When a carbon monofilament, produced from coal tar pitch, is heated in the range of 1,100°-2,500° C., its resistance will drop. However, following the boron flash and graphite skin treatments, the treated monofilament has a resistance per unit of length less than one half as great as the lowest resistance per unit length of the above-mentioned untreated carbon monofilament.
More significantly, when a boron coating is deposited on an untreated carbon monofilament, which has been heated above 1,100° C., such as, to 2,500° C., the problem, which the addition of a boron flash cures, persists.
A carbon monofilament that has undergone boron flash and graphite skin treatments contains a visually observable skin layer. The skin layer is definitely not B 4 C. As B 4 C is a semiconductor, it would cause a rise in resistance at room temperature.
There have been indications that small quantities of boron in combination with carbon acts as a catalyst to convert amorphous carbon catalytically to graphite when the amorphous carbon containing a boron is raised to elevated temperatures. The demonstrable drop in resistance noted above is consistent with the development of a highly oriented graphitic skin coating.
The most widely used boron filament has a nominal diameter of 4.0 mils. A nominal 1.3 mil carbon core is used. In practice, the core may vary from 1.0-1.4 mils in diameter.
The graphite skin layer appears to contain some elemental boron and boron in combination with carbon. These inclusions appear in very small amounts and do not materially affect the performance of the graphite skin layer.
Untreated, the 1.3 mil carbon monofilament core has a resistance of about 700 ohms/inch when made. This can be reduced by heating the carbon monofilament above 2,100° C to about 550 ohms/inch.
Typically, a 0.1-2.5 microns flash coating of boron is applied, with 0.1-1 micron being preferred. When the carbon monofilament with boron flash is heated as prescribed, a 0.02-0.05 mil skin layer of oriented graphite is produced. Preferably, the skin layer of graphite should not exceed 0.2 mil.
The aforementioned 0.1-2.5 micron boron flash coating appears to be a narrow window. The procedure deteriorates with heavier boron flash coatings. The preferred procedure is successive flash coatings of 0.1-2.5 microns followed by heat treating to produce thick graphite skin layers, in the order of 0.1-0.2 mil.
The resistance of the 1.3 mil carbon monofilament with a graphitic skin layer is typically in the order of, but generally less than 200 ohms/inch.
It is evident that those skilled in the art, once given the benefit of the foregoing disclosure, may now make numerous other uses and modifications of, and departures from the specific embodiments described herein without departure from the inventive concepts. Consequently, the invention is to be construed as embracing each and every novel feature and novel combination of features present in, or possessed by, the apparatus and techniques herein disclosed and limited solely by the scope and spirit of the appended claims. | 4y
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[0001] This application claims priority of Application No. 094211846 filed in Taiwan, R.O.C. on Jul. 12, 2005 under 35 U.S.C. § 119, the entire contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The invention relates to a wheel control mechanism for a baby stroller and, in particular, to a remote control mechanism for switching the wheel seat between a fixed-direction mode and a free steering mode.
[0004] 2. Description of the Prior Art
[0005] If a user is pushing a baby stroller and the front wheel is then set into a fixed-direction mode, the user must press the handle bar of the baby stroller downward in order to tilt the front wheel upwards, in order to change the direction of the baby stroller. This is both laborious to the user and dangerous to the baby sitting in the baby stroller. To reduce labor involved in directional changes and more smoothly push the baby stroller, some strollers have a front wheels with both a fixed-direction mode and free steering mode. When the front wheels are switched into the fixed-direction mode, the stroller will move in a straight direction, and when the front wheels are switched into the free steering mode, the direction of the stroller can be more easily changed. An example of this type of front wheel can be seen, for example, in U.S. Pat. No. 6,671,926. However, the operation of a stroller with this type of front wheel is inconvenient, as the user must bend their body down to reach the wheels, in order to switch the wheels into another mode.
SUMMARY OF THE INVENTION
[0006] In order to avoid the problems found in the prior art, the present invention provides a remote control mechanism for switching the modes of the stroller wheels. This allows a user to have a far-end controller, to switch the wheels between a fixed-direction mode and a free steering mode. The mechanism includes a far-end controller, a connecting member, and a positioning member. The far-end controller drives the positioning member through the connecting member. The positioning member is used to catch the wheel of stroller and fix it into a fixed-direction mode, and is capable of releasing the wheel back into a free steering mode. The far-end controller of the present invention can be installed on any portion of the frame of a stroller, to enable a user to shift the steering mode without bending down. The far-end controller of the present invention also removes the need to suspend the front wheel in order to change the steering direction of the baby stroller.
[0007] Further scope of the applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] 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:
[0009] FIG. 1 is a schematic side view of a fixed-direction wheel control mechanism for a baby stroller, installed in the frame of the baby stroller;
[0010] FIG. 2 is a schematic, exploded view of the members of the fixed-direction wheel control mechanism for a baby stroller of the present invention;
[0011] FIG. 3 is a schematic, exploded view of the wheel assembly of the present invention;
[0012] FIG. 4 is a schematic, cross-sectional view showing the positioning member moved into the positioning portion of the wheel seat of the present invention;
[0013] FIG. 5 is a schematic, cross-sectional view showing the positioning member moved out from the positioning portion of the wheel seat of the present invention;
[0014] FIG. 6 is a schematic, isometric, exploded view of the far-end controller members of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0015] FIG. 1 is an embodiment of the fixed-direction wheel control mechanism ( 1 ) equipped on the frame of a stroller to facilitate switching wheels between a fixed-direction mode and a free steering mode. In this embodiment, the fixed-direction wheel control mechanism ( 1 ) is installed between the handle tube ( 12 ) of a baby stroller ( 10 ) and a wheel assembly ( 2 ), and includes a far-end controller ( 5 ), a connecting member ( 6 ), and a positioning member ( 3 ).
[0016] In this embodiment, the frame of the baby stroller ( 10 ) includes a front foot tube ( 11 ) having an end extended towards the center section thereof, and a handle tube ( 12 ) for a user to hold in order to push the baby stroller around.
[0017] As shown in FIGS. 2 and 3 , the wheel assembly ( 2 ) is equipped at the lower end of the front foot tube ( 11 ) and includes a base seat ( 21 ) and a wheel seat ( 22 ). The base seat ( 21 ) is connected to the lower end of the front foot tube ( 11 ) and includes a fastener ( 23 ) to keep the base seat ( 21 ) connected with the wheel seat ( 22 ).
[0018] The wheel seat ( 22 ) for a carrying wheel ( 20 ) has a pivot shaft ( 24 ) extending upwardly from the top portion thereof, for pivotally connecting the wheel seat ( 22 ) with the base seat ( 21 ). A limiting ring ( 241 ) is provided at the distal end of the pivot shaft ( 24 ). The wheel seat ( 22 ) is capable of rotating freely with the pivot shaft ( 24 ), and is detachable from the base seat ( 21 ) before the fastener ( 23 ) is secured into the limiting ring ( 241 ). To catch the wheel seat ( 22 ) and fix the wheel seat ( 22 ) to prevent it from freely rotating, the top of the wheel seat ( 22 ) is provided with a recess to form a positioning portion ( 25 ). Preferably, a spring ( 26 ) can be provided at the wheel seat ( 22 ) to absorb any shocks from a bumpy road, to provide a smoother ride for the baby sitting on the stroller.
[0019] As shown in FIGS. 2 and 4 , a positioning member ( 3 ) pivotally connected to the base seat ( 21 ) includes a connecting end ( 31 ) and a salient block ( 32 ). The salient block ( 32 ) is installed between the base seat ( 21 ) and the positioning member ( 3 ). In this embodiment, the salient block ( 32 ) can be a compression spring for biasing the positioning member ( 3 ) to move into the positioning portion ( 25 ), in order to catch and fix the wheel seat ( 22 ). In this way, the baby stroller is kept in a fixed-direction mode.
[0020] As shown in FIGS. 2 and 5 , the resilient element ( 4 ) is compressed and the positioning member ( 3 ) is pulled by connecting member ( 6 ) and removed from the positioning portion ( 25 ). In this way, the baby stroller is switched into a free steering mode.
[0021] In the present embodiment, the fixed-direction wheel control mechanism ( 1 ) includes a far-end controller ( 5 ), a connecting member ( 6 ) and a positioning member ( 3 ). The connecting member ( 6 ) is connected between the far-end controller ( 5 ) and the connecting end ( 31 ) of the positioning member ( 3 ). The far-end controller ( 5 ) is capable of being installed on any portion of the frame of baby stroller ( 10 ), to allow a user to more conveniently switch the wheel modes without bending their body in front of the stroller. In the present embodiment, as shown in FIGS. 1, 4 and 5 , the far-end controller ( 5 ) is equipped on the side of handle tube ( 12 ), in order to facilitate the switching operation.
[0022] As shown in FIG. 4 , the connecting member ( 6 ) can be made of any flexible material, such as a wire, as is illustrated in the present embodiment. When switching the stroller into free steering mode, a user draws the connecting member ( 6 ) by forcing the far-end controller ( 5 ) to move on the handle tube ( 12 ). In this way, the salient block ( 32 ) leaves the positioning portion ( 25 ) and releases the wheel seat ( 22 ).
[0023] As shown in FIG. 5 , when the connecting member ( 6 ) is released, the resilient element ( 4 ) pushes the salient block ( 32 ) back into the positioning portion ( 25 ). Inthis way, the stroller is kept in a fixed-direction mode.
[0024] As shown in FIGS. 1 and 6 , the far-end controller ( 5 ) includes a securing seat ( 51 ), a pulling member ( 52 ), a push button ( 53 ), and a restoring spring ( 54 ). The securing seat ( 51 ) is equipped at the handle tube ( 12 ) of the frame of baby stroller ( 10 ). The pulling member ( 52 ) is pivotally connected to the securing seat ( 51 ) and is connected to an end of the connecting member ( 6 ). The pulling member ( 52 ) includes a handle ( 521 ) and a positioning slot ( 522 ). The push button ( 53 ) includes a press portion ( 531 ) and a positioning tooth ( 532 ). The restoring spring ( 54 ) is installed between the push button ( 53 ) and the pulling member ( 52 ), and maintains the positioning tooth ( 532 ) of the push button ( 53 ) locating at the positioning slot ( 522 ) of the pulling member ( 52 ), in order to fix the pulling member ( 52 ). This makes the pulled member ( 52 ) unable to turn under normal conditions. When the user presses the push button ( 53 ), the positioning tooth ( 532 ) of the push button ( 53 ) is capable of separating from the positioning slot ( 522 ), in order to make the pulling member ( 52 ) turn freely to pull the connecting member ( 6 ).
[0025] By using the above-mentioned members, as shown in FIG. 4 , the resilient element ( 4 ) biases the salient block ( 32 ) and maintains the salient block ( 32 ) in the positioning portion ( 25 ). Meanwhile, the wheel seat ( 22 ) is caught and fixed, and the stroller is switched into a fixed-direction mode. As shown in FIGS. 4 and 6 , once a user wishes for the wheel seat ( 22 ) to turn freely, he or she can manipulate the push button ( 53 ) of the far-end controller ( 5 ) to release the limitation with respect to the pulling member ( 52 ). At this moment, the user can turn the pulling member ( 52 ) to pull the connecting member ( 6 ) through the handle ( 521 ). Since the connecting member ( 6 ) is connected between the pulling member ( 52 ) and the positioning member ( 3 ), once the pulling member ( 52 ) is turned, the positioning member ( 3 ) will be driven to turn, thereby compressing the resilient element ( 4 ). In this way, the salient block ( 32 ) of the positioning member ( 3 ) will be separated from the positioning portion ( 25 ) of the wheel seat ( 22 ), in order to release the limitations with respect to the wheel seat ( 22 ). This allows the wheel seat ( 22 ) to turn freely. At this moment, the user releases the push button ( 53 ) of the far-end controller ( 5 ) to allow the positioning tooth ( 532 ) of the push button ( 53 ) to engage with the positioning slot ( 522 ) of the pulling member ( 52 ), by using the resilience of the restoring spring ( 54 ). In this way, the positioning member ( 3 ) is able to maintain a released position, for releasing the limitations with respect to the wheel seat ( 22 ), as shown in FIG. 4 .
[0026] 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 as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to a routing cutter. More particularly, it relates to such a routing cutter which has an upper housing part accommodating a drive motor and provided with a cutting tool at its lower side, and a base plate which is displaceable and fixable relative to the upper housing part through a column guide.
Routing tools of the above mentioned general type are known in the art. One of such routing tools is disclosed in the German document DE-PS No. 3,347,764. In this routing tool the height adjusting device is formed as a spindle which curves a swinging projection for turning the cutting tool introduced in the workpiece under the head of an adjusting screw arranged in a revolving abutment on the supporting table. During the cutting, the supporting table is fixed relative to the upper housing part by means of an arresting screw additionally on the column guide arranged between the supporting plate and the upper housing part.
A return spring is arranged between the supporting plate and the upper housing part and serves for automatically pressing back the supporting plate acting as a supporting ring, after release of the arresting devices. Therefore a contact of the cutting tool in the final position is prevented. The depth limitation of this known routing cutter can also be released by a handle for performing respective accident preventing measures. Thereby a second handle is required for spring biasing the supporting plate back after the release of the arresting screw.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a routing cutter in which the respective accident preventing steps can be performed better, and every time the tool can be lowered onto the workpiece only with a single handle and can be moved back behind the protective ring.
This is very important since the routing cutters because of the high rotary speed and their sharp-edges tools pause extraordinarily high dangers. Since these manual machines are used in free time by non-experienced people, a considerable simplification is required for their handling.
In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a routing tool of the above mentioned general type in which the column guide includes a sleeve arranged in the upper housing part and displaceable in the displacement direction of the column guide relative to the upper housing part, and a rod fixable to and adapted to be guided in the sleeve and connected with the base plate.
When the routing cutter is designed in accordance with the present invention, the cutting tool every time can be moved back behind the protective ring with a single handle. This results in a previously unknown advantage in the safety of the operation of such cutting machines. At the same time, a fine adjustment of different cutting depths preadjusted by means of revolving abutments in modern routing cutters can be obtained to the full extent, and also the possibility of a post-adjustment is maintained. In accordance with the present invention with the coarsely adjusted cutting depth, a well-accessible rotary knob provides an adjustment in correspondence with the scale without releasing the clamping device.
It is especially advantageous when the rotary knob is provided with a scale ring adjustable relative to the rotary knob. In this manner the zero point of the scale can be set at any arbitrary position to improve the operational comfort. Furthermore, the fine adjustment can be obtained by a thread-containing sleeve against the force of a pressure spring. Thereby inaccuracies are prevented, which can result from expected thread play.
The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a routing cutter in accordance with the present invention in position placed on a workpiece;
FIG. 2 is a partial side view of the routing cutter in a working position;
FIG. 3 is a plan view of the routing cutter in accordance with the present invention;
FIG. 4 is a section of a routing cutter in accordance with the second embodiment of the present invention; and
FIG. 5 is a view showing a routing cutter in accordance with the third embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A routing cutter shown in FIG. 1 has a housing with an upper housing part 10 which is connected through a column guide 12 of FIG. 2 with a base plate 14. A bellows 16 protects the column guide from dirtying. A handle 18 is mounted on the upper housing part 10 and has a switching handle 20 which controls a drive motor arranged in the upper housing part 10. The drive motor drives a milling or cutting tool 24 which is inserted in a collet 22 and illustrated in broken lines. The tool 24 has a vertical axis. The routing cutter is placed with its base plate 14 on an upper surface of the workpiece 26. In a known manner, a cutting depth coarse adjusting device 28 is provided outside of the upper housing part.
The adjusting device 28 includes a bar 30 which is arranged displaceably in the vertical direction in a guide 29 and arrestable by a clamping screw 32. The bar 30 is provided at its upper end with an indicating mark 34 associated with a scale 36 provided on the upper housing part 10 for obtaining respective readings. The above mentioned cutting depth coarse adjusting device 28 also includes a revolving abutment 38 arranged rotatably on the outer side of the base plate 14. Abutment screws 40 are inserted in a known manner in the revolving abutment 38. The lower end 31 of the bar 30 abuts against the heads of the abutment screws 40.
In FIG. 2 the adjusting device 28 of FIG. 1 is not shown for the sake of clarity of the drawing. The right column in the drawing of the column guide is designed in a known manner. It has a hollow rod 41 which is fixedly connected with the base plate 14. A pressure spring 43 is located in the hollow rod 41 and abuts against the base plate 14 and the upper housing part 10. The rod 41 is displaceably guided in the upper housing part 10.
A rod 42 is also fixedly connected with the base plate as can be seen in FIG. 2. A sleeve 44 which is closed at its upper end is guided on the rod 42. The sleeve 44 is guided in an axially displaceable manner in the upper housing part 10 and has an opening 46 which extends radially to the sleeve axis in the lower region. A clamping ring 48 is mounted at the height of the opening 46 outside of the sleeve 44.
The clamping ring 48 has a radial thickening with an inwardly threaded opening in alignment with the opening 46. A clamping screw 50 is screwed in this inwardly threaded opening. A pressing member 52 is arranged between the clamping screw 50 and the rod 42. The upper end surface of the clamping ring 48 forms a lower abutment shoulder 56 for a pressure spring 58 arranged around the sleeve 44.
The pressure spring 58 acts within the position of a disc 60 on an abutment shoulder 62 formed on the upper housing part 10. The abutment shoulder 62 is arranged around an opening 64 in the upper housing part 10. The upper region of the sleeve 44 provided with outer thread 66 extends through the opening 64 outwardly of the upper housing part 10.
A rotary know 68 which is sleeve-shaped in its lower region has there an inner thread 70 that cooperates with the outer thread 66 formed in the upper sleeve 44, to displace the sleeve 44 vertically whereby a fine adjustment is effected. The rotary knob 68 is centered in its lower end in the opening 64. A collar 72 of the rotary knob 68 abuts outside of the upper housing part 10 and positions the rotary knob 68 in the axial direction.
A scale ring 74 sits on the outer side of the collar 72. The fit between the scale ring 74 and the rotary knob 68 is dimensioned so that the scale ring 74 can be rotated easily by hand relative to the rotary knob 68. An adjusting mark 76 is formed on the upper housing part 10 and corresponds with the scale ring 74.
During the operation with the routing cutter, first the required cutting depth is coarsely adjustment on the abutment screws 40 in FIG. 1. When several abutment depths are to be adjusted, this can be achieved by respective rotation of the abutment screws 40. The number of revolutions in connection with the thread pitch of the abutment screws 40 determine a stabbing point. In this manner the basic adjustment is performed.
When it is determined during subsequent testing cutting or during operation with the inventive routing cutter that the cutting depth previously adjusted on the abutment screws 40 requires a correction, this is performed without releasing the clamping screw 50 on the rotary knob 68. When bar 30 of the cutting depth coarse adjusting device 28 eventually abuts against the head of an abutment screw 40, the clamping screw 32 of FIG. 1 is temporarily released.
In this manner the fine adjustment can be performed by rotation of the rotary knob 68 in FIG. 2. The repeatability of the depth adjustment by the cutting depth coarse adjusting device 28 is guaranteed in connection with the abutment screw 40. The scale ring 74 which is adjustable each time to its zero point provides for an additional facilitation.
During the cutting process the base plate 14 is arrested against the upper housing part 10 only by the clamping screw 50. For permitting a risk free stopping of the routing cutter after the end of the cutting process, the base plate in the manual routing cutter machines serves as an automatically back springing protecting ring which surrounds the cutting tool and thereby reduces the danger. For this purpose it is required that the arresting of the base plate 14 relative to the upper housing part 10 is released with a movement of the handle.
In the inventive routing cutter this requirement is fulfilled when a short rotation of the clamping screw 50 releases the arresting and the cutting tool 24 is pulled because of the pressure spring 43 acting as a return spring, behind the outer contour of the base plate 14 back and can be stopped without danger.
A different embodiment shown in FIG. 4 differs from the above described embodiment in that the disc 60 is formed directly on the rotary knob 68b. The mounting of such a rotary knob 68b is easily possible when the upper housing part 10 is formed of shells with a separating plane extending parallel to the cutter axis. This mounting can be performed before the connection of the housing shells.
Further modifications of the above described invention are also possible. It is for example possible to form the left rod of the column guide which surrounds the sleeve 44 also has a whole rod 41. This embodiment is shown in FIG. 5. Here also the design of the rotary knob 68b and the scale ring 74a is varied. The clamping screw 50 which acts on this rod is turned in this Figure from the plane of the drawing and therefore not seen in FIG. 5.
This clamping screw can be formed for example as a wing screw which can be operated from a handle 78 formed on the upper housing part 10.
In the embodiment of FIG. 5 a disc 80 with a friction reducing coating is provided between the contact surfaces on the collar 72 and the upper housing part 10. This facilitates the fine adjusting process. Instead of the above mentioned disc 80 also an axial roller bearing can be utilized.
It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.
While the invention has been illustrated and described as embodied in a routing cutter, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.
Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No. 11/430,260, filed May 8, 2006 which is a continuation-in-part application of U.S. Ser. No. 11/326,255, filed Jan. 5, 2006, the disclosures of which are hereby incorporated by reference herein.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to ceiling fans. More particularly, this invention relates to ceiling fan blades having a high-efficiency design.
[0004] 2. Description of the Background Art
[0005] Presently, there exist numerous types of ceiling fans designed to be suspended from a ceiling for circulating air flow within the room. Typically, ceiling fans comprise a plurality of ceiling fan blades which are operatively connected to an electric motor for rotating the fan blades to produce the desired air flow. The components of the ceiling fan, particularly the ceiling fan blades, are designed to optimize the amount of air flow being circulated per watt of energy consumed to thereby achieve high efficiencies.
[0006] The fan blades constitute one aspect of a ceiling fan which is an important factor in achieving high efficiencies. Ceiling fan blades commonly include an elongated planar or curvilinear structure having a proximal or root end which is coupled to a fan blade bracket which is, in turn, coupled to the rotor of the electric motor. The elongated planar fan blade is positioned by the fan blade bracket at an optimal angle (e.g., 11 to 17 degrees) to circulate air flow at high efficiencies.
[0007] Elongated planar ceiling fan blades are commonly manufactured of a medium-density fiber (“MDF”), laminated plywood, carved wood or plastic. More particularly, MDF fan blades are manufactured from large sheets of MDF wood that are pressed together to the desired thickness, typically 5.5 millimeters. The surface of the MDF sheets are protected by vinyl sheeting which are overlaid onto the MDF sheets and glued to the surface thereof (upper and lower) to form a watertight seal therewith. The MDF sheets are then positioned within a cutting machine which cuts out the individual ceiling fan blades from the MDF sheet in the desired pattern. The leading and trailing edges of the fresh-cut ceiling fan blade, as well as the tip and root ends of the fan blade, are then routed and sanded to produce a round edge with the vinyl extending thereto. Since the vinyl only extends up to the rounded edge, the rounded edge of the ceiling fan blade is then painted with a waterproof paint to seal the rounded edge so that moisture cannot penetrate into the rounded edge and seep underneath the vinyl sheet. Warpage of the fan blade, which would otherwise deteriorate the fan blade causing it to wobble, is therefore minimized.
[0008] Similar to MDF blades, plywood blades have been used for many years. Unlike MDF blades, plywood blades are typically lighter in weight, stronger and less likely to warp due to their cross grain construction and multiple plies. More particularly, conventional plywood commonly includes three plies of cross grain planar sheets of wood. During the manufacture of plywood fan blades, two sheets of the three ply plywood are glued to form a plywood sheet having six plies. The sheet of plywood is often covered with a vinyl material (upper and lower) that may include a solid color or a wood grain appearance. Alternatively, one or both sides of the plywood may be covered by a light colored paper. As in the case of manufacturing the MDF fan blades, the plywood sheets are then cut to the desired blade shape and their edges are routed and sanded to have a rounded edge. Similar to MDF fan blades, since the vinyl only extends to the rounded edges, the rounded edges are then painted with a waterproof sealant to preclude any ingress of moisture that might otherwise cause de-lamination of the plywood.
[0009] Plastic fan blades are most commonly used for outdoor fans and decorative fans, and may include a simulated wicker or rattan appearance. Plastic fan blades offer the advantage of being formed into curvilinear configurations, such as those shown in U.S. Pat. Nos. 6,659,721 and 6,039,541, the disclosures of which are hereby incorporated by reference herein. Unfortunately, however, since plastic is typically heavier than plywood or MDF, plastic fan blades result in higher resistance to the electric motor thereby necessitating increased torque. Moreover, due to gravity acting on the blades, the plastic blades must be thick enough to preclude them from warping or drooping over time. Consequently, plastic blades are often significantly thicker than their plywood or MDF counterparts. To reduce the likelihood of drooping, plastic blades may include a slightly raised center rib to add longitudinal strength.
[0010] The rounded edges of MDF blades, plywood blades and plastic blades present a thick edge. Consumers view the thick edge with appreciation because the thick rounded edge gives the ceiling fan an appearance of better quality. Unfortunately, however, the thick rounded leading edges of conventional fan blades produce a significant air resistance and turbulence as the ceiling fan blades are rotated through the air to cause the desired air flow. The increased resistance and turbulence along the leading edge of the thick rounded leading edge of the fan blade appreciably reduces the efficiency of the ceiling fan. In the case of the thicker plastic blades, even greater inefficiencies are often experienced.
[0011] Efforts to produce thinner blades that would correspondingly have thinner rounded edges, have met with little success since thinner blades do not have the necessary strength to function properly during continued use without droopage. Moreover, prior art techniques for “beveling” the leading edge of a ceiling fan blade, such as taught by Taiwan Patent Application 79200819, filed Jan. 22, 1990, the disclosure of which is hereby incorporated by reference herein, have not met with any commercial success. More particularly, beveling the leading edge of a ceiling fan blade such as taught by the Taiwanese patent application produces a relatively sharp knife edge that creates a hazardous condition in the event a person's hand or other object is moved into the path of the spinning fan blades. Indeed, industry safety regulations applicable to ceiling fans mandate that the leading edge of the fan blade must be greater than 3.30 millimeters thick so as to reduce the likelihood of injury should a person's hand or other object move into the path of the rotating fan blades. Similar to the Taiwanese patent, U.S. Pat. No. 5,554,006, the disclosure of which is hereby incorporated by reference herein, teaches a ceiling fan blade configuration having a concave blade periphery. However, this patent does not address the safety issues. See also design Pats. D507,644; D505,724; D503,795; D516,207; D516,208; D503,475; D503,476; D503,473; D503,472 and D503,474, the disclosures of each of which are hereby incorporated by reference herein.
[0012] As noted above, recent improvements to ceiling fan blade designs have been achieved by manufacturing the ceiling fan blades in a longitudinal curvilinear configuration as opposed to a longitudinal planar configuration. The curvilinear blade commonly includes a substantial angle (e.g. 30 degrees) at its root or proximal end connected to the ceiling fan blade bracket which gradually tapers to the more traditional angle of 11 to 17 degrees toward the distal end or tip of the fan blade. The airfoil configuration imitates the airfoil wing of an airplane for increased “lift” correspondingly to increase air flow when the airfoil configuration is employed as a ceiling fan blade. This curvilinear configuration increases air flow at the center portion of the fan more than what can be achieved by using planar fan blades. Unfortunately, like planar fan blades, curvilinear fan blades still produce appreciable resistance and turbulence along their leading edges.
[0013] There presently exists a need in the ceiling fan industry for improved ceiling fan blades that operate safely to achieve high efficiencies. Therefore, it is an object of this invention to provide an improvement which overcomes the aforementioned inadequacies of the prior art devices and provides an improvement which is a significant contribution to the advancement of the ceiling fan blade art.
[0014] Another object of this invention is to provide a ceiling fan having a high efficiency fan blade that meets industry-wide safety standards.
[0015] Another object of this invention is to provide a ceiling fan having a high efficiency fan blade that is protected from moisture by a vinyl or other coasting applied to its surfaces and to at least a portion of its edges.
[0016] Another object of this invention is to provide a ceiling fan having upper and/or lower surfaces of the ceiling fan blades covered by suitable decorative and/or protective sheeting, such as vinyl or paper sheeting that extends all the way out to cover at least a portion of the thin leading edge with the exposed uncovered portion of the thin leading edge coated with a sealant to prevent moisture intrusion.
[0017] Another object of this invention is to provide a ceiling fan having upper and/or lower surfaces of the ceiling fan blades covered by suitable decorative and/or protective sheeting, such as vinyl or paper sheeting that extends all the way out and around the thin leading edge, thereby precluding the necessity for a sealant coating since there are no exposed uncovered portion that may otherwise absorb moisture.
[0018] Another object of this invention is to provide a ceiling fan having upper and/or lower surfaces of the ceiling fan blades covered by suitable decorative and/or protective sheeting, such as vinyl or paper sheeting that presents an extremely aesthetically clean appearance to the consumer over what would otherwise be observed by the consumer if the thin leading edge was not at all covered by the sheeting.
[0019] The foregoing has outlined some of the pertinent objects of the invention. These objects should be construed to be merely illustrative of some of the more prominent features and applications of the intended invention. Many other beneficial results can be attained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to the summary of the invention and the detailed description of the preferred embodiment in addition to the scope of the invention defined by the claims taken in conjunction with the accompanying drawings.
SUMMARY OF THE INVENTION
[0020] For the purpose of summarizing this invention, this invention comprises a ceiling fan having high efficiency fan blades. More particularly, several embodiments of the high efficiency fan blades of the invention each comprise a thin-edge configuration that effectively reduces thickness of the leading edge of prior art ceiling fan blades such that the thinner leading edge of the invention presents less resistance and produces less turbulence than thicker prior art fan blade edges. The thin-edge fan blades of the invention therefore result in high efficiencies.
[0021] More particularly, one embodiment of the high efficiency ceiling fan blades of the invention comprises a generally planar or curvilinear elongated configuration (MDF, plywood, carved wood or plastic) with a reduced-thickness or thin leading edge. In one variation, the thin leading edge achieves a leading edge thickness equal to or appreciably greater than the industry standard minimum thickness. The thin leading edge then gradually tapers or steps into the thickness of a conventional MDF, plywood or plastic blade. The thin leading edge is preferably centered relative to the usual thickness of the blade. Alternatively, however, the reduced-thickness edge may be positioned at one surface of the fan blade, preferably the lower surface.
[0022] Importantly, the thin leading edge of the invention is easily adapted to all types of ceiling fan blades that are currently being manufactured. For example, in the case of plastic fan blades, the thin edge design of the invention may be easily injection molded. In the case of plywood fan blades and MDF fan blades, the edge of the fan blade may be easily routed to the desired thin edge design and then sealed with a waterproof sealer painted onto the exposed edges.
[0023] In another embodiment of the high efficiency ceiling fan blades of the invention, the upper surface of the ceiling fan blades may comprise a generally apex configuration defined by two planar surfaces formed at an angle leading from the opposing thin leading edges across the width of the fan blade to form an apex along a center line of the fan blade. Importantly, the thickness of the fan blade at the thin leading edges comprises a reduced thickness which is equal to or appreciably greater than the minimum thickness mandated by applicable ceiling fan safety regulations. It is noted that the thin leading edge of this embodiment of the invention is contemplated to be principally formed by plastic injection molding or through carved fan blades due to the angles involved that could not typically be achieved through the use of laminated plywood or MDF. Indeed, this second embodiment is particularly desirable for implementation with decorative plywood or carved wood fan blades that would normally require significant sanding or carving to achieve the desired decorative designs. Moreover, the apex configuration provides strength along the longitudinal length of the fan blade thereby reducing the likelihood of drooping due to gravity over extended periods of non-use.
[0024] In still another embodiment of the high efficiency ceiling fan blades of the invention, the upper and/or lower surfaces of the ceiling fan blades may be covered by suitable decorative and/or protective sheeting, such as vinyl or paper sheeting. According to the invention, the sheeting is adhesively applied to one or both of the surfaces (i.e., upper and/or lower) of the fan blade by an adhesive or the like. The sheeting extends, in one embodiment, all the way out to cover at least a portion of the thin leading edge. The exposed uncovered portion of the thin leading edge is then coated with a sealant to prevent moisture intrusion. Whereas, in another embodiment, the sheeting extends all the way out and around the thin leading edge, thereby precluding the necessity for a sealant coating since there are no exposed uncovered portion that may otherwise absorb moisture. If similar sheeting is also applied to the other surface of the ban blade, the last-applied sheeting may extend all the way out and around the thin leading edge as to overlap the corresponding sheeting previously applied to the other surface.
[0025] In both of these embodiments, the sheeting protects all or substantially all of the thin leading edge of the fan blade from moisture intrusion along the thin leading edge that would otherwise potentially result in swelling or warping of the fan blade. It is noted that in the embodiment in which the sheeting does not wrap around the thin leading edge to overlap similar sheeting on the other side, the exposed rounded leading edge of the fan blade is nevertheless coated with moisture-barrier paint or the like, thereby precluding moisture instruction along the thin edge of the blade. In both embodiments, the fact that the sheeting extends over all, or at least a significant portion of the edge, presents an extremely aesthetically clean appearance to the consumer over what would otherwise be observed by the consumer if the thin leading edge was not at all covered by the sheeting.
[0026] The foregoing has outlined rather broadly the more pertinent and important features of the present invention in order that the detailed description of the invention that follows may be better understood so that the present contribution to the art can be more fully appreciated. Additional features of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] For a fuller understanding of the nature and objects of the invention, reference should be had to the following detailed description taken in connection with the accompanying drawings in which:
[0028] FIG. 1 is a side elevational view of the ceiling fan of the invention with its thin edge ceiling fan blades;
[0029] FIG. 2 is a transverse cross-sectional view of a conventional MDF ceiling fan blade showing the planar construction thereof, the laminated vinyl material to the opposing surfaces thereof and the waterproof sealant painted onto the leading and trailing edges thereof;
[0030] FIG. 3 is a transverse cross-sectional view of FIG. 1 of the thin edge ceiling fan blade of the first embodiment of the invention along lines 30 - 30 thereof as viewed toward the root of the fan blade;
[0031] FIG. 4 is a is a transverse cross-sectional view of the second embodiment of the invention;
[0032] FIG. 5 is a transverse cross-sectional view of the third embodiment of the invention;
[0033] FIG. 6 is a transverse cross-sectional view of the fourth embodiment of the invention;
[0034] FIG. 7 is a transverse cross-sectional view of the fifth embodiment of the invention;
[0035] FIG. 8 is a transverse cross-sectional view of the sixth embodiment of the invention as viewed toward the tip of the fan blade;
[0036] FIG. 9 is a transverse cross-sectional view of the seventh embodiment of the invention;
[0037] FIG. 10 is a is a transverse cross-sectional view of the eighth embodiment of the invention;
[0038] FIG. 11 is a transverse cross-sectional view of the ninth embodiment of the invention;
[0039] FIG. 12 is a transverse cross-sectional view of the tenth embodiment of the invention;
[0040] FIG. 13 is a transverse cross-sectional view of the eleventh embodiment of the invention;
[0041] FIG. 14 is a transverse cross-sectional view of the twelfth embodiment of the invention as viewed toward the tip of the fan blade;
[0042] FIG. 15 is a transverse cross-sectional view of the thirteenth embodiment of the invention;
[0043] FIG. 16 is a is a transverse cross-sectional view of the fourteenth embodiment of the invention;
[0044] FIG. 17 is a transverse cross-sectional view of the fifteenth embodiment of the invention;
[0045] FIG. 18 is a transverse cross-sectional view of the sixteenth embodiment of the invention;
[0046] FIG. 19 is a transverse cross-sectional view of the seventeenth embodiment of the invention;
[0047] FIG. 20 is a transverse cross-sectional view of the eighteenth embodiment of the invention as viewed toward the tip of the fan blade;
[0048] FIG. 21 illustrates the method of the invention for manufacturing one or more of the embodiments of the invention disclosed in FIGS. 3-20 , showing the manner in which the sheeting is applied to at one surface of the fan blade;
[0049] FIG. 22 illustrates the method of the invention for manufacturing one or more of the embodiments of the invention disclosed in FIGS. 3-20 , showing the manner in which the applied sheeting is pressed onto the surface of the fan blade to assure adequate adherence to the surface thereof and to at least a portion of the thin edge thereof;
[0050] FIG. 23 illustrates the method of the invention for manufacturing one or more of the embodiments of the invention disclosed in FIGS. 3-20 , showing the use of automatic or hand side rollers for further assuring that the sheeting is fully adhered to the thin edge of the fan blade;
[0051] FIG. 24 illustrates the method of the invention for manufacturing one or more of the embodiments of the invention disclosed in FIGS. 3-20 , showing the manner in which the excess sheeting is sanded from edge of the ceiling fan; and
[0052] FIG. 25 illustrates the method of the invention for manufacturing one or more of the embodiments of the invention disclosed in FIGS. 3-20 , showing the manner in which the excess sheeting is cut from edge of the ceiling fan.
[0053] Similar reference characters refer to similar parts throughout the several views of the drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0054] FIG. 1 is a side elevational view of a conventional ceiling fan 10 comprising an electric motor assembly 12 and a plurality of ceiling fan blades 14 connected to the rotor of the motor assembly 12 by means of ceiling blade brackets 16 . The ceiling fan 10 is intended to be connected by means of a hanger and down rod assembly 18 to the ceiling 20 of a room. During operation in one direction, the rotating ceiling fan blades 14 circulate air downwardly from the ceiling 20 (typically during summer months). During operation in the reverse direction, the rotating ceiling fan blades 14 circulate air upwardly toward the ceiling 20 (typically during winter months). In either direction, the objective is to create a circulatory flow of air throughout the room to thereby reduce energy costs.
[0055] FIG. 2 is a cross sectional view of a conventional ceiling fan blade 16 manufactured from an MDF material. More particularly, an MDF fan blade 16 comprises a generally planar elongated configuration having a width “W” and a thickness “T 1 ” composed of an MDF laminate 18 . Commonly, a sheet of a vinyl material 20 is adhered to the upper and lower surfaces of the MDF material 18 . The sheeting material 20 may comprise many different colors and/or decorative appearances such as wood grains. The longitudinal edges 22 are routed to a bull nose configuration and sanded smooth. Since the sheeting 20 thus extends up to but not over the bull nose rounded longitudinal edges 22 , the bull nose rounded longitudinal edges 22 are then sealed by painting them with a waterproof sealant 24 . It is noted that when employing plywood instead of MDF, a similar procedure is used to route the bull nose rounded edges 22 that are then sealed with the sealant 24 painted thereon. In the case of plastic fan blades that are injection molded, the vinyl sheeting 20 may alternatively comprise a sheeting of paper material which too may comprise a variety of colors or decorative designs such as a wood grain.
[0056] The first of the many embodiments of the invention are now described in relation to FIGS. 3-8 . More particularly, each of these embodiments of the invention of FIGS. 3-8 comprises a ceiling fan blade 30 manufactured by any available manufacturing technique such as methods for producing MDF blades, plywood blades, plastic blades or carved blades, to create a generally planar or curvilinear fan blade 30 having a thickness T 1 . At least the thin leading edge 32 and alternatively also the trailing edge 34 comprise a reduced thickness T 2 which is appreciably thinner than the thickness T 1 of the fan blade 30 . The thin leading edge 32 of thickness T 2 more preferably equals or exceeds the applicable safety standard that defines the minimum thickness for ceiling fan blades.
[0057] As shown in FIGS. 3 and 4 , the thin leading edge 32 of the fan blade 30 of the invention is positioned in the middle of the thickness T 1 of the blade 30 . As shown in FIG. 3 , the angled edge portion comprising the transition between the thin leading edge 32 and the opposing surfaces 30 U and 30 L of the fan blade 30 comprises a concave step 36 which blends into a rounded edge portion 32 whereas in FIG. 4 , the angled edge portion comprising the transition comprises a generally planar transition 38 which blends into a rounded edge portion 32 . In both embodiments of FIGS. 3 and 4 , the rounded edge portion 32 may be sanded or chamfered to eliminate any sharp corners between the transitions 36 and 38 and the thin leading edge portion 32 .
[0058] As shown in FIGS. 5 and 6 , the rounded edge portion 32 is positioned closer to the bottom surface 30 L of the fan blade 30 rather than being positioned midway as shown in the previous embodiments of FIGS. 3 and 4 . More particularly, as shown in FIG. 5 , the angled edge portion comprising the transition between the rounded edge portion 32 and the upper surface comprises a stepped configuration 40 whereas the angled edge portion comprising the transition in FIG. 6 comprises a generally planar transition 42 . As in the case of embodiments of FIGS. 3 and 4 , the rounded edge portion 32 may be sanded or chamfered to break any sharp edges that might otherwise occur with the respective transitions 40 and 42 .
[0059] As noted above, the trailing edge 34 of the ceiling fan blade 30 of the invention may likewise comprise a thin edge 32 of one of the embodiments described above. The double thin edge embodiments are particularly useful in the event the ceiling fan 10 will be operated in a reverse direction whereupon the blades rotate in reverse thus the former trailing edge becomes a leading edge, and vice versa. Furthermore, without departing from the spirit and scope of the invention, it should be appreciated that one embodiment of the rounded edge portion 32 may be used with any of the other embodiments. Finally, it is noted that the embodiments of FIGS. 3 and 4 are the same whether or not the blades are installed upside down in reverse whereas the embodiments of FIGS. 5 , 6 and 7 are not contemplated to be reversible.
[0060] As shown in FIG. 7 , still another embodiment of the thin edge ceiling fan blade 30 of the invention comprises a generally apex configuration wherein the upper surface 30 U of the fan blade comprises two angled surfaces 30 AU extending from opposing thin leading edges 32 and 34 to a longitudinal apex 30 A, preferably positioned at or proximate to the longitudinal center of the fan blade 30 .
[0061] The longitudinal apex 30 A of the fan blade 30 according to this embodiment produces increased structural integrity along the longitudinal length of the fan blade 30 to further reduce wobbling or drooping over time.
[0062] The foregoing embodiments of FIGS. 1-6 were shown as generally planar ceiling fan blades 14 with its opposing surfaces being generally parallel to each other. However, as shown in FIG. 8 , any of the thin edge embodiments of FIGS. 1-6 may be incorporated into the leading edge 32 of curvilinear ceiling fan blades 14 such as those of U.S. Pat. Nos. 6,039,541 and 6,659,721, previously incorporated by reference herein.
[0063] More particularly, as shown in FIG. 8 , a curvilinear ceiling fan blade 14 comprises an airfoil 50 composed of an upper surface 50 U and a lower surface 50 L that produces a lifting force when rotated. Furthermore, a curvilinear fan blade 14 often comprises an increasing “twist” formed along its elongated configuration from its tip to its root, such that, preferably, the same volume of airflow is achieved along its entire length even though the tip of the blade 14 is moving faster than its root. The incorporation of the thin leading edge 32 of the invention into curvilinear fan blades 14 increases the efficiency by reducing resistance and turbulence.
[0064] FIG. 9 illustrates the seventh embodiment of the ceiling fan 30 of the invention in which a sheeting 20 is applied to one surface 30 U or 30 L of the ceiling fan blade 30 to extend onto the angled edge portions 36 and 38 of that surface to leave exposed the rounded edge portions 32 , 34 . FIG. 10 illustrates the eighth embodiment of the ceiling fan 30 of the invention in which a sheeting 20 is applied to one surface 30 U or 30 L of the ceiling fan blade 30 to extend onto the angled edge portions 36 and 38 of that surface and around the rounded edge portions 32 , 34 .
[0065] As shown in FIGS. 9 and 10 with the sheeting 20 applied to only to one surface 30 U or 30 L, the exposed rounded edge portions 32 , 34 ( FIG. 9 ) and the exposed edge portions 36 and 38 of the other surface 30 L or 30 U ( FIGS. 9 and 10 ) are then coated with a sealant to prevent any moisture ingress into the ceiling fan blade 30 . More specifically, as shown in FIG. 10 with the sheeting applied to only one surface (e.g., 30 U), but not the other surface (e.g., 30 L), the exposed rounded edge portion 32 , 34 as well as the exposed angled edge portion 38 of the other surface 30 L, are coated with the sealant to prevent any moisture ingress along the thin edge of the fan blade 30 . It is noted that the exposed surface (e.g. 30 U) of the fan blade 30 that is not covered with the sheeting 20 may likewise be coated with a sealant to prevent moisture ingress into the ceiling fan 30 .
[0066] Similarly, with respect to FIG. 11 in which the rounded edge portion 32 , 34 extends along one side (e.g. 30 L) to define only one angled edge portion 40 , the sheeting 20 is applied to the other surface (e.g. 30 U) to extend across the entire surface thereof and onto the angled edge portion 40 . The rounded edge portion 32 , 34 left exposed may be coated with a moisture sealant to prevent any moisture from being absorbed by the ceiling fan blade 30 . In FIG. 12 , the sheeting 20 extends over the angled edge portion 42 and around the rounded edge portion 32 , 34 thereby obviating the need for a sealant.
[0067] With regard to FIG. 13 , the sheeting 20 may be applied over the apex surface 30 UA to extend across the entire surface thereof up to the rounded edge portion 32 , 34 .
[0068] For curvilinear ceiling fan blades as shown in FIG. 14 which may be configured with any of the edge embodiments of FIGS. 3-6 , the sheeting 20 may be applied across the upper surface 50 U to extend onto at the angled edge portion 36 .
[0069] Still other embodiments of the ceiling fan 30 of the invention are shown in FIGS. 15-20 . Corresponding to FIGS. 9-14 , respectively, the embodiments of FIGS. 15-20 include sheeting 20 which is applied to both surfaces 30 U and 30 L of the ceiling fan blade 30 . In regard to the symmetrical embodiment of FIG. 15 , the sheeting 20 may extend over the respective angled edge portions 36 leaving the rounded edge portion 32 , 34 exposed, to then be sealed as described above. Alternatively, as shown in the other symmetrical embodiment of FIG. 16 , the sheeting 20 applied to both surfaces 30 U and 30 L of the ceiling fan blade 30 may extend beyond the angled edge portions 38 around onto the rounded edge portions 32 , 34 in either an overlapping manner (see right edge portion 32 ) or an abutting relationship (see left edge portion 34 ).
[0070] With regard to the non-symmetrical embodiment of FIG. 17 , the sheeting 20 may be applied to one surface 30 U or 30 L to extend over the angled edge portion 40 and around the rounded portion 32 , 34 whereas the other sheeting 20 applied to the other surface 30 L or 30 U may be simply applied to that surface to extend in an overlapping relationship (see right edge portion 32 ) or an abutting relationship (see left edge portion 34 ) with respect to the sheeting 30 from the first surface 30 U or 30 L. Likewise, in the non-symmetrical embodiment of FIG. 18 , the sheeting 20 may be applied to both surfaces 30 U and 30 L to extend over the angled edge portion 42 and overlap each other along the rounded edge portion 32 , 34 .
[0071] The apex embodiment of FIG. 19 may include similarly-applied sheeting 20 to the upper and lower surfaces 30 U and 30 L and the rounded edge portion 32 , 24 , to either overlap (see right rounded edge portion 32 ) or abut (see left rounded edge portion 34 ) each other.
[0072] Finally, in the curvilinear ceiling fan blade 14 , the sheeting 20 may be applied to both surfaces 50 L and 50 U to extend over their respective angled side portions 36 and the rounded edge portion 32 , 34 to either overlap (see left rounded edge portion 32 ) or abuts (see right rounded edge portion 34 ) each other.
[0073] Without departing from the spirit and scope of this invention, as noted previously, the ceiling fan blades 30 may be manufactured from any available technique, with or without the sheeting 20 (e.g., vinyl or paper) on one or both of the surfaces 30 U and 30 L thereof and with or without sealing of the exposed longitudinal edges 32 and 36 - 42 thereof. However, preferred manufacturing methods are illustrated in FIGS. 21-28 .
[0074] As shown in FIG. 21 , an over-sized sheet of sheeting 20 is adhesively applied to one of the surfaces 30 U or 30 L of the ceiling fan blade 30 . The adhesive application may comprise an adhesive that is applied to the mating surfaces 30 U or 30 L of the ceiling fan blade 30 and/or the sheeting 20 , or the sheeting 20 may comprise a self-adhesive surface for adherence to the fan blade surfaces 30 U or 30 L.
[0075] As shown in FIG. 22 , pressure is applied to the sheeting to forcibly apply the sheeting 20 to the respective surface 30 U or 30 L of the ceiling fan blade 30 . Preferably, the pressure is applied by passing the ceiling fan blade 30 with the applied sheeting 20 under a compression roller 52 that is composed of a resilient material such that the sheeting 20 is firmly pressed onto the surface 30 U or 30 L of the ceiling fan blade 30 without any trapped air that might otherwise create air bubbles. Moreover, the resiliency of the roller 52 is such that the sheeting 20 is pressed along the angled edge portions 36 - 42 as the ceiling fan blade 30 passes under the roller 52 .
[0076] It is noted that the foregoing is most applicable to the embodiments of FIGS. 9 , 11 , 13 , 14 and 15 in which the sheeting 20 extends only onto the angled edge portions 36 - 42 but not onto the rounded edge portions 32 , 34 . With regard to the embodiments of FIGS. 10 , 12 , 16 , 17 , 18 , 19 and 20 , in which the sheeting 20 extends also around onto the rounded edge portions 32 , 34 , a further manufacturing step comprises, as shown in FIG. 23 , the additional application of an edge rollers 54 to assure that the sheeting 20 is firmly affixed to the rounded edge portions 32 , 34 . While the edge roller 54 may comprise a simple hand-operated edge 54 roller operated by a factory worker, preferably, the edge roller 54 comprises fixed side rollers 54 between which the ceiling fan blade 30 is passed to press the sheeting 20 onto the rounded edge portions 32 , 34 .
[0077] Due to the over-sized configuration of a sheeting 20 , it is noted that the sheeting 20 , once applied, will have excess edges that extend beyond the edge of the ceiling fan blade (see FIGS. 22 and 23 ). As shown in FIG. 24 , the excess sheeting 20 may be trimmed by a sanding operation against a rotary sander 56 or, as shown in FIG. 25 , by an edge cutter instrument 58 .
[0078] With respect to the embodiments of FIG. 15 in which the sheeting 20 is applied to both of the surfaces 30 U and 30 L of the fan blade 30 and onto the edge portions 36 - 42 but not around the rounded edge portions 32 , 34 , the application step of FIG. 21 would include application of the sheeting to both surfaces 30 U and 30 L followed by the pressing step of FIG. 22 and the trimming step of 24 and 25 . With respect to the embodiments of FIGS. 16-20 in which the sheeting 20 is applied to both of the surfaces 30 U and 30 L of the fan blade 30 and onto the edge portions 36 - 42 and then around the rounded edge portions 32 , 34 to an overlapping or abutting relationship, the pressing step of FIG. 22 and the trimming step of FIGS. 24 and 25 may be performed with respect to one surface 30 U or 30 L and then repeated for the other surface 30 L or 30 U.
[0079] 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 scope of the invention.
[0080] Now that the invention has been described, | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to an alternating actuation device for a needling machine.
The present invention also relates to such a needling machine provided therewith, used for mechanically consolidating a fibre fleece coming, for example, from a crosslapper.
The known needling machines comprise a support called a board on which needles are fixed. Alternating actuation devices, having rods and cranks, impart an alternating motion to the board in order that the needles traverse the fibre fleece at a rate which can vary between 1000 and 2000 strokes per minute during production.
Additional devices also make it possible to regulate the flow of fibres entering and leaving the machine with or without drawing and at speeds chosen according to the striking rate and the number of strokes per minute, equivalent to the number of alternating movements of the needles per minute.
DE-A-1 660 778 describes an actuation device in which a crankshaft supported by four bearings drives the needle board with an alternating motion by the intermediary of two connecting rods. A bearing is shown on each side of each connecting rod in a diagrammatic way and without any corresponding description.
DE-A-2 111 496 describes successive crankshafts disposed along an upper beam of the needling machine. Each crankshaft end is supported by a bearing. In another arrangement, the crankshafts, parallel instead of being aligned, are disposed transversely with respect to the beam. Considering the limited width of the beam, the bearings are brought towards the centre and are thus positioned between a central equilibration means and each actuating eccentric for actuating the connecting rods.
These known devices operate in free air and are lubricated with grease.
Actuation devices are also known which are mounted in a sealed crankcase and which are lubricated with oil. In this case the crankshaft, oriented in the direction of the width of the fleece to be needled, is supported in rotation by two bearings mounted in openings provided in two opposite end walls of the crankcase. Between the two bearings, the crankshaft comprises two eccentrics forming cranks, each one of them connected to an actuating connecting rod, and supports equilibration means of the inertia and/or counterweight type. The crankshaft emerges from the crankcase through each of the bearings in order to be connected to a driving source and/or to another coaxial crankshaft, belonging to another actuation device.
The known actuation devices are subjected to high alternating loads which generate dangerous vibrations and noise. The force necessary to make the needles penetrate into the fleece is high. This results in generous dimensioning of the moving parts of the alternating actuation devices. The result of this is that large inertial forces are added to the intermittent force of penetration and extraction of the needles, and that the reciprocating actuation devices are subjected to substantial mechanical stresses and deformations. Finally, it is necessary to limit the striking rate.
The purpose of the invention is to increase the striking rate permitted to needling machines and/or to reduce the harmful effects of the alternating loads at a given rate.
SUMMARY OF THE INVENTION
According to a first aspect of the invention, the needling machine actuation device comprising a crankcase in which at least one crankshaft is supported in rotation by at least two bearings, the crankshaft comprising two eccentrics with each of which is articulated one of the ends of a connecting rod intended to be connected at its other end, at least indirectly, to a needle board, equilibration means furthermore being attached to the crankshaft, is characterized in that the two bearings are supported inside the crankcase at a position situated axially between the two eccentrics, in that the equilibration means are situated axially between the two bearings, and in that each eccentric is situated between the respective one of the two bearings and a peripheral wall of the crankcase.
Thus, the distance between the two bearings is small, and this considerably reduces the deformation in flexion of the crankshaft.
Furthermore, the bearings are supported closer to each other inside the crankcase, which increases the rigidity of their mutual positioning, and consequently further reduces the deformations which the crankshaft can undergo. The bearing supports which, according to the invention, it is necessary to provide inside the crankcase, can be designed as internal reinforcements for the crankcase.
In particular, these supports can be produced in the form of internal walls or partitions which brace the outer walls of the crankcase.
Because of the invention, the deformations generated by the striking forces and the inertia in the actuation device are considerably lessened, the mechanical reliability is increased, the vibrations are small, and consequently the striking rate can be increased.
According to a second aspect of the invention, the needling machine for mechanically consolidating a fibre fleece, comprising:
means of causing the fibre fleece to move in a plane of motion,
a needle board support,
actuation means for mechanically actuating the needle board support in a reciprocating manner in a transverse direction with respect to the plane of motion,
is characterized in that the actuation means comprise at least one device according to the first aspect of the invention.
Other features and advantages of the invention will emerge from the following description, relating to non-limitative example embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
FIG. 1 is a diagrammatic partial cross-sectional front view of a needling machine according to the invention, the right hand half of the figure corresponding to a variant;
FIG. 2 is a view along II--II of FIG. 1;
FIG. 3 is a detail view of a bearing, showing two variants simultaneously;
FIG. 4 is a view of a detail of the crankshaft; and
FIGS. 5 and 6 are views similar to FIGS. 3 and 4 respectively, but relating to another family of variants.
DETAILED DESCRIPTION
The needling machine shown in FIGS. 1 and 2 comprises a generally horizontal perforated table 2, also called a "stripper", placed in an approximately parallel manner a certain distance above the table 1. The table 1 and the stripper 2 defining between them a path in a substantially horizontal plane for a fibre fleece 3. The stripper 2 comprises perforations aligned with those of the table 1. At the entrance to the path are placed insertion means 4 (FIG. 2) represented in the form of a pair of drive rollers between which the fleece 3 passes. At the exit of the path, the fleece 3, which has been consolidated and compacted by needling, is driven by extractor means 6 which are also represented by two drive rollers between which the fleece passes.
The stripper 2 is placed between the path of the fleece 3 and a series of needle boards 7. The needle boards 7 are disposed in two rows which succeed one another in the direction of motion of the fleece 3 (FIG. 2). In each row, the needle boards 7 are aligned with the width of the path of the fleece 3 (FIG. 1).
Each board 7 carries, on the stripper 2 side, a large number of needles 8 oriented perpendicularly with respect to the plane of the path of the fleece 3, with their points directed towards the fleece 3. Each needle is positioned opposite a perforation of the stripper 2 and a corresponding perforation in the table 1. Each needle board 7 is fixed, on the side opposite to the needles 8, to a support 9 which itself fixed to the ends of two rods 11 each mounted such that it slides along an axis 12 parallel to the needles 8 and perpendicular to the plane of the path of the fleece 3. The rods 11 associated with the boards of a same row are situated in a same plane perpendicular to the direction of progress of the fibres. For its sliding guidance, each sliding rod 11 is guided in two axially spaced coaxial slide bearings 13 and 14. The bearings 13 and 14 are rendered integral with a sealed crankcase 16 which will be described later. The bearings 13 and 14 comprise, for example, anti-friction rings 17 for the contact with the rod 11. The bearings 14 are followed in the direction of the support 9, by means, which are not shown, ensuring the sealing of the crankcase around each rod 11.
Each mobile mechanism constituted by the association of two sliding rods 11, the support 9 and the board 7 is driven, in service, with an alternating reciprocating motion in the direction 12 between a position 7a (FIG. 2) in which the ends of the needles, in this case denoted by 8a, traverses the stripper 2, the fleece 3 and the table 1 and a withdrawn position 7b in which the needles 8 are totally withdrawn at least from the table 1 and the fleece 3 and possibly from the stripper 2.
In order to impart this reciprocating motion to the mobile mechanism, the rod 11 is articulated by an articulation 18 with one end of a connecting rod 19 whose other end is connected by an articulation 21 to an eccentric 22 which is part of a crankshaft 23 driven in rotation by driving means which are not shown.
As shown in FIG. 1 there is one crankshaft 23 for each support 9. The crankshafts 23 associated with the supports 9 of the same row are coaxial and coupled in rotation about their common axis 24 by coupling devices 26. The devices 26 are of a known type capable of transmitting a strong rotational torque, substantially without angular play about the axis 24, while still accepting that the crankshafts 23, instead of being strictly coaxial, form a slight angle with respect to each other. Thus, each crankshaft 23 can work in flexion independently from the two crankshafts 23 with which is coupled by the coupling devices 26.
At one of the ends of each row of needle boards, the corresponding crankshaft 23 is coupled at least indirectly to a drive motor (not shown), and at the other end of the row, the corresponding crankshaft 23 has a free end.
There are therefore two rows of crankshafts 23, one for each row of needle boards, as illustrated in FIG. 2.
Simultaneous observation of FIGS. 1 and 2 shows that the machine comprises as many crankcases 16 as there are needle boards 7 in one of the rows. Each crankcase 16 supports in rotation two crankshafts 23 whose axes 24 are parallel and which are associated with two needle boards 7 located side by side and each one belonging to one of the rows. Each crankshaft 23 (FIG. 1) carries inertia equilibration means for stabilizing the rotational motion and possibly having a counterweight for counterbalancing the equivalent off-centred mass which is in rotation about the axis 24 of each crankshaft. The equilibration means 27 are of known type.
The crankcases 16 are fixed to a frame 28 of the needling machine, shown diagrammatically and partially in FIG. 2 and also able to support, in a fixed or adjustable manner, the table 1, the stripper 2 and the insertion 4 and extraction 6 devices. Each crankcase 16 is composed of two partial crankcases 29 and 31 forming body and cover respectively. The partial crankcases 29 and 31 are fixed to each other in a jointing plane 32 containing the geometric axes 24 of the two crankshafts 23.
The slide guide 13 and 14 for the sliding rods 11 are supported by the body 29. The cover 31 closes the body 29 on the side opDosite the sliding rods 11. Each crankshaft 23 comprises two cylindrical bearing surfaces 32 each one situated between the respective one of the eccentrics 22 and a central zone 33 on which are mounted the equilibration means 27. Each cylindrical bearing surface 33 cooperates with a respective roller bearing 34 supported by the crankcase 16. Each eccentric is situated axially between one of the bearings 34 on the side nearest the inside of the crankcase 16 and a sealing device 36 which ensures sealing between the crankshaft 23 and an orifice 37 in the peripheral wall of the crankcase 16, through which the crankshaft 23 extends towards the outside of the crankcase 16, as far as the adjacent coupling device 26. Each orifice 37 is jointly defined by the two partial crankcases 29 and 31, each of which comprises a corresponding half-bore. The orifices 37 are not provided with bearings. The crankcase 16 thus encloses, in a sealed manner, for each of the two associated crankshafts 23, the two eccentrics, the two bearings, the equilibration means 27 the two connecting rods 19 and the two articulations 18. The assembly is lubricated with oil retained inside the crankcase because of the sealing of the latter.
The crankcase 16 comprises support means 38 in order to support the bearings 34. In the example shown in the left-hand side of the crankcase 16 shown in FIG. 1, which corresponds to the example shown in FIG. 2, the support means 38 comprise, for each pair of coplanar bearings 34, a partition 39 formed in one piece with the body 29 of the crankcase 16. The partition 39 is connected to the front and rear walls 41 of the body 29 and to the bottom wall 42 of the latter, thus forming a rigidifying brace between these walls 41 and 42.
As shown in more detail in FIG. 3, the wall 39 comprises in its free edge 43 located in the jointing plane 32, for each of the two coplanar bearings 34, a semi-circular recess 44 whose diameter corresponds to the outer diameter of the bearing 34. According to a first embodiment shown in the left-hand half of FIG. 3, the bearing 34 is retained in the recess 44 by a cap 46 having a semi-circular internal face 47 of the same diameter and which is applied over the rest of the periphery of the bearing 34. The cap 46 is fixed by two opposite lugs 48 against the free edge 43 of the partition 39 by means of screws 49.
In a variant embodiment shown in dotted and dashed line in the left-hand part of FIG. 3, the recess 44, instead of being borne by the partition 39 can be borne by a cradle 51 fitting into a larger recess 52 formed in the free edge 43 of the partition 39. The cradle 51 comprises two opposite lugs 53 (only one of which can be seen in FIG. 3). Each screw 49 traverses a lug 48 of the cap 46 and a corresponding lug 53 of the cradle 51, and tightens these two lugs stacked against the upper recessed edge of the partition 39.
According to the third embodiment shown in the right-hand part of FIGS. 1 and 3, and which will be described only where it differs from the first embodiment, there is a second partition 54 which belongs to the cover 31 of the crankcase 16. A free edge 56 of the partition 54 is situated in the jointing plane 32 such that it is adjacent to the free edge 43 of the partition 39 when the two partial crankcases 29, 31 are assembled with each other.
The edge 56 of the partition 54 has for each of the two coplanar bearings 34 a semi-circular recess 57 of the same diameter as the recess 44 of the partition 39. When the two partial crankcases 29, 31 are assembled with each other, the recess 57 is brought into correspondence with the recess 44 in order to form a circular opening strictly positioning the bearing 34.
In the diagrammatic representations shown in FIGS. 1 and 2, the eccentrics 22 are shown with a relatively large off-centring in order to make the drawings clearer.
In practice, as the forward and backward travel necessary for the needle boards 7 is only a few centimetes, a much lower off-centering suffices and an embodiment of the type shown in FIG. 4 is therefore advantageous. The diameter D 1 of the bearing surface 32 is greater than the diameter D 2 of the eccentric 22 so that the bearing 34 can, in a first step in its assembly, reach the position 34a by slipping over, starting from the corresponding end of the crankshaft 23, that is to say the end situated on the same side of the equilibrations means 27 as the bearing 34 in the process of being installed. In order to allow the bearing 34 to reach the position 34a, it is provided for example, as shown, that the diameter D 3 of the end of the crankshaft 23 is sufficiently small for the peripheral surface of the eccentric 22 to be radially projecting everywhere with respect to this end.
If the eccentric 22 were directly adjacent to the bearing surface 32, the passage of the bearing 34 from the position 34a to the service position on the bearing surface would necessitate the diameter D 1 being at least equal to the diameter D 2 of the eccentric 22 increased by two times the off-centring E of the eccentric 22. In order that the minimum diameter D 1 required for the bearing surface 32 may be less than that value, there is provided between the eccentric 22 and the bearing surface 32 a transition zone 58 which, in an angular region 58a, is radially recessed with respect to the region 22a where the periphery of the eccentric 22 is furthest from the axis 24 of the crankshaft 23. The maximum radial dimension M of the eccentric 22 and of the transition region 38 taken together is less than the diameter D 1 of the bearing surface 32. This allows the bearing 34 to pass from the position 34a to a position 34b around the transition region 58, whose axial dimension L is greater than that of the bearing 34. The transition region 58 is for example produced in the form of a cylinder having, with respect to the axis 24, an off-centering (e) less than the off-centering "E" of the eccentric 22, The off-centering "e" and "E" are oriented in the same radial direction from the axis 24. The periphery of the transition region 58 is everywhere radially recessed with respect to the bearing surface 32, such that the bearing 34 can without difficulty be fitted over the bearing surface 32 starting from the position 34b. In order to avoid the useless creation of regions of weakness on the crankshaft 23, the transition region 58 has a diameter which is as large as possible. The result of this is that the transition region 58 has an angular region 58b which radially protrudes with respect to the region 22b where the periphery of the eccentric 22 is closest to the axis 24 of the crankshaft.
The central zone 33 of the crankshaft 23 has a diameter D 4 , greater than the maximum radial dimension N of the eccentric 22 and of the bearing surface 32 considered together, which allows, before the fitting of the bearing 34, the fitting without difficulty of the equilibration means 27 starting from the end of the crankshaft 23 even if, as shown, the axial dimension of the equilibration means 27 is greater than the axial dimension L of the transition region 58. The bearing 34 is retained axially between a shoulder 59, separating the bearing surface 32 and the central zone 33, and an elastic stop ring 61.
In the example shown in FIGS. 5 and 6, which will be described only where it differs with respect to that shown in FIGS. 3 and 4, the roller bearing 34 is replaced by a plain bearing 34 comprising two semi-cylindrical bushes 64 which can be fixed such that one of them is in the recess 44 of the wall 39 or of the cradle 91 and the other is in the recess 57 of the cap 46 or of the wall 54. The assembly resembles that of the connecting rod bearing bushes of a thermal engine with cylinders and pistons for the connection between the connecting rods and the crankshaft of the engine. In particular, the fitting of the bearing does not necessitate any fitting over from the ends of the crankshaft. Thus, the bearing surface 32 can, as shown, be radially recessed with respect to the other regions of the crankshaft, situated axially on both sides of the bearing surface 32, without this resulting in an impossibility of fitting. Axial stops, which are not shown, can ensure the axial positioning of the crankshaft 23, but this is not essential since in theory the crankshaft is not subjected to any axial load. As in the preceding example, the diameter D 4 of the central region 33 of the crankshaft 23 is at least equal to the maximum radial dimension N which the equilibration device 27 must clear by slipping over starting from the end of the shaft.
The invention is of course not limited to the examples described and shown.
In the examples where there is only one single internal partition such as 39 for supporting each bearing, this partition could be integral with the cover of the crankcase instead of being integral with the body of the crankcase as has been described.
In order to allow the fitting of the bearings and of the equilibration means without having recourse to the advantageous solution described with reference to FIG. 4, it would be possible to produce the crankshaft in the form of two half-crankshafts attached to one another in the region of the central zone 33 after the fitting of the bearings and of the equilibration means starting from the central zone 33, which would havea diameter at most equal to that of the bearing surface 32.
It would also be possible, starting from an embodiment according to FIG. 4 or FIG. 6, to produce each equilibration device 57 in two parts attached to one another in a substantially axial jointing plane, in order to avoid the necessity of assembly by slipping over.
In this case, the diameter of the central region 33 of the crankshaft can be chosen freely with respect to the other diameters of the crankshaft. | 4y
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation application of U.S. patent application Ser. No. 10/951,454 filed Sep. 27, 2004, issuing as U.S. Pat. No. 7,000,515,which is a continuation of U.S. patent application Ser. No. 09/253,110 filed Feb. 19, 1999, and are incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to a movable, protective, sawdust collection hood for use with a table saw equipped with a rotary saw blade and, more particularly, to such a hood that provides a directed air stream for removal of sawdust generated by a saw blade rotating on a shaft located below a work table.
[0004] 2. Background Art
[0005] Protective hoods have become widely used to remove sawdust generated by the cutting of a work piece on a rotary table saw, and to conduct the dust toward a sawdust collection receptacle. The hoods have additionally served to protect the user thereof from injury due to inadvertent contact with a rotating saw blade. Such hoods have generally taken the form of a longitudinally elongated enclosure, open at the bottom, having a pair of spaced-apart. vertical walls joined at their upper edges by a top wall, and adapted for placement over an exposed, upper peripheral portion of a saw blade, the saw blade being mounted for rotation on a shaft located below the work table of the table saw. Protective hoods of this kind have been configured such that air was drawn into the hood through an air intake opening (due to an air current created by rotation of the saw blade and/or by an attached vacuum or blower system), from whence air streamed across the blade and out a discharge opening toward a sawdust collection receptacle, carrying the sawdust away with it. Retractable apparatus was provided to support the hood in position over the saw blade--for example, by a link arm having one end attached to the hood and an opposite end attached to a splitter mounted to the table saw behind the saw blade. Attached to a front portion of the vertical walls was a forwardly inclined nose having horizontal leading and trailing edges, such that rearward advancement of a work piece toward and against the nose panel caused the hood to rise, and with further such movement of the work piece the trailing edge of the nose rested on and made sliding contact with an upper surface of the work piece. An example of protective hoods of this kind is disclosed in U.S. Pat. No. 4,576,072 to Terpstra et al. An alternative retractable support for such a protective hood, i.e., a parallelogram linkage and counterbalance mechanism, was disclosed in U.S. Pat. No. 4,875,398 to Taylor et al.
[0006] Such heretofore known protective hoods, however, failed to adequately remove sawdust and chips generated at the final stage of a cutting operation. Initially, during a cutting operation, so long as a work piece progressed rearwardly under the hood, across the upper surface of the work table and past the saw blade, sawdust and chips generated within the hood remained confined within the hood to be carried away by the air stream within the hood. But, after the cutting of a work piece had progressed to the stage at which the forwardmost portion of the work piece had moved underneath and rearward of a front portion of the hood, a gap was created between the hood and the work piece, thereby permitting sawdust and chips to be thrown forward through the gap and to escape from the hood. My invention overcomes this problem by eliminating the gap at the final stage of cutting a work piece.
SUMMARY OF THE INVENTION
[0007] According to the present invention there is provided a protective, sawdust collection hood for a table saw. The table saw is equipped in conventional fashion with a saw blade mounted for rotation on a shaft located below a horizontal work table, and having an exposed, peripheral portion thereof extending above the worktable and rotating toward the front side of the work table. The table saw is also equipped with a splitter mounted directly behind the saw blade. In a first embodiment, the hood is adapted for pivotal attachment to the splitter, whereby the hood can be moved between a retracted, storage position and a working position directly over and straddling the exposed portion of the saw blade. The hood includes a pair of spaced-apart, vertical side panels, each side panel having a front, central and rear portion. A forwardly inclined nose panel is mounted between front portions of the side panels, and has horizontal leading and trailing edges. An upper cowl is mounted between the side panels, and has a substantially vertical, front portion terminating at a forward edge that engages an upper surface of the nose panel, and has a rearwardly extending, upwardly inclined portion terminating at a rear edge. A lower cowl is mounted between the side panels below the upper cowl and has a substantially vertical, front portion and rearwardly extending, substantially horizontal, central and rear portions. The front portion of the lower cowl terminates in a horizontal forward edge disposed above the trailing edge of the nose panel. A pair of vertical side skirts are provided, each of the skirts being movable between a first, lowered position and a second, raised position, and means are attached to the side panels for suspending a side skirt from each of the side panels. In this first embodiment, each of the side skirts has a substantially vertical slot, and the means for suspending the side skirts include a slot pin attached to and extending laterally outward from a central portion of the adjacent side panel, retainer means attached to each slot pin for retaining the pin within the slot, and stop means attached to the side skirts for limiting the downward movement of the side skirts when the hood is raised away from the work table. The side panels, upper cowl, lower cowl, and side skirts are made of a rigid transparent material so that an operator of the table saw can see through the hood to monitor cutting operations.
[0008] During the initial stages of cutting a work piece, the side skirts are in the lowered position, the lower edge of each skirt being just even with the trailing edge of the nose panel. As the work piece is then moved rearwardly across the work table toward and against the nose panel, the hood rises until the trailing edge of the nose panel rests upon an upper surface of the work piece, thereby completing the initial stage. There then follows an intermediate cutting stage, wherein the work piece progresses rearwardly toward and past the saw blade with the trailing edge continuing to rest on, and make sliding contact with an upper surface of the work piece. During the intermediate stage, the side skirts remain in the lowered position. The final cutting stage occurs when the forwardmost portion of the work piece has been moved rearward underneath the side skirts and has fully cleared the nose panel; at that time the nose panel drops down to the work table, thereby closing the gap that would otherwise exist between the upper surface of the work table and the hood, and the side skirts move up into the raised position. Thereafter, once the work piece has fully cleared the saw blade and the side skirts, the side skirts also drop down from the raised position to the lowered position and come to rest on the work table. The cut having been completed, the cut portions of the work piece can then be removed from the work table.
[0009] Throughout each of the stages of cutting a work piece, sawdust is carried by a directed stream of air away from the situs of cutting within the hood and toward a sawdust collection receptacle. Air enters the hood through an intake opening defined by rear portions of the side skirts and a rear portion of the lower cowl, thence streams forward over the work piece and saw blade and through an orifice defined by the forward edge of the lower cowl, the trailing edge of the nose panel and the front portions of the side panels, and thereafter is conducted rearwardly between an upper surface of the lower cowl and a lower surface of the upper cowl to exit the hood. In this manner, sawdust and chips generated by cutting a work piece, including that generated in the final stage of cutting, remains confined within the hood while being conducted toward a collection receptacle.
[0010] Although rotation of the saw blade is sufficient to create the above-described air stream, the air stream flow rate can be increased by attaching a vacuum source to the hood. Therefore, in a preferred embodiment, the hood further includes a rear discharge wall mounted between an upper surface of a central portion of the lower cowl and the rear edge of the upper cowl. The rear discharge wall has an air discharge hole. A vacuum hose adapter is attached to a rear surface of the rear discharge wall and is aligned with the air discharge hole. A vacuum hose having one end connected to the adapter, and an opposite end attached to a shop vacuum or other vacuum source, provides vacuum suction to the hood for increased air flow through the hood.
[0011] In a second embodiment of the hood, the hood is pivotally attached to the splitter by two pairs of parallel, equal-length links, forming a parallelogram linkage. In this embodiment, each of the slots in the side skirts is arcuate and the above-described means for suspending the side skirts further includes a first pair of parallel, equal-length, skirt support arms disposed on opposite sides of the hood, each of said support arms having a first end pivotally attached to a side panel and a second, opposite end pivotally attached to a front portion of a side skirt; and said means further includes a second pair of parallel, equal-length, skirt support arms disposed on opposite sides of the hood, each of said support arms having a first end pivotally attached to a side panel and a second, opposite end pivotally attached to an upper rear portion of a side skirt.
[0012] In a third embodiment, the hood further includes a vacuum conduit assembly for drawing sawdust and wood chips away from the saw blade and through the hood to a collection receptacle. A collar joint is provided for pivotally attaching a rear portion of the hood to the vacuum conduit assembly, which permits rotation of the hood about a horizontal axis between a raised, storage position and a lowered, working position. The vacuum conduit assembly comprises a vacuum source connected to an electric power source; a laterally disposed, elongated, cylindrical, hollow boom having an intake end and an opposite discharge end; a hollow, cylindrical head stock mounted to the intake end of the boom and coaxial therewith, said head stock having an intake duct extension in communication with the interior of the head stock, and said intake duct being attached to, and in communication with, the collar joint; a movable vacuum hose within the boom, having a first, intake end storable within the head stock, and an opposite, discharge end with an attached hose end ring seal that is slidable within the boom; and a stationary vacuum hose having one end attached to the discharge end of the boom and an opposite end attached to the vacuum source. In this manner, a vacuum created by the vacuum source is communicated through the stationary and movable hoses to the head stock and thence to the hood.
[0013] The collar joint comprises a first, semicylindrical, partial collar attached to an intake end of the vacuum conduit assembly, said partial collar being axially-aligned on a lateral axis A′-A′ and extending between rear portions of the side panels, and said collar having longitudinally-aligned, front and rear openings. The collar joint further comprises a second, semicylindrical, partial collar that partially surrounds and engages the first partial collar. The second partial collar is rotatable about the lateral axis A′-A′ and about a front, exterior surface of the first partial collar. The second partial collar is mounted between a rear edge of the lower cowl and a rear edge of the upper cowl, and is laterally disposed between rear portions of the side panels. The second partial collar has an air discharge hole that is in register with the front opening of the first partial collar when the hood is in a working position directly over and straddling the saw blade. A collar pin is laterally inserted along axis A′-A′ through the rear portions of the side panels, through tab projections from the intake end of the vacuum conduit assembly, and through the first and second partial collars. Preferably, the boom comprises a stationary portion and, in telescoping relation thereto, a laterally movable portion. The laterally movable portion of the boom is attached to the head stock. A rack and pinion assembly couples the laterally movable portion to the stationary portion of the boom, thereby permitting lateral adjustments of the position of the hood with respect to the saw blade and fence. A normally-closed, momentary switch, wired in series with the vacuum electric power source, is mounted on the head stock, such that, whenever the hood is moved to the raised, storage position adjacent the head stock, the momentary switch is opened, thereby de-energizing the vacuum source. For locking the hood in the raised, storage position, the nose panel has a retainer aperture engagable by a spring catch mounted on the head stock. The head stock is provided with a removable cap, whereby, with the cap removed, the intake end of the movable vacuum hose may be withdrawn from the head stock and used to vacuum clean the table saw and its immediate environs, and thereafter replaced inside the head stock.
[0014] Important objectives of the present invention therefore include the following:
[0015] It is an object of the invention to provide a protective hood for a rotary table saw that carries sawdust and chips away from the situs of cutting and toward a sawdust receptacle, even during the final stage of cutting a work piece.
[0016] It is a further object of the invention to provide such a protective hood that is movable between a retracted and a working position directly over and straddling the saw blade.
[0017] The above and other aspects and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a perspective view of a rotary table saw as viewed from a position at the front, left of the saw, and showing a first embodiment of the movable, protective hood, mounted by a single pivot to a splitter, and in a working position resting upon the work table;
[0019] FIG. 2A is an enlarged, left side view thereof;
[0020] FIG. 2B is an enlarged top plan view thereof;
[0021] FIG. 2C is an enlarged, rear elevational view thereof;
[0022] FIG. 3A is a left side view thereof showing the hood in a raised, working position after a work piece has been moved rearwardly under the nose panel and partially underneath the side skirts, preparatory to entering upon cutting by a rotating saw blade, and further showing the side skirts in a lowered position relative to the nose panel;
[0023] FIG. 3B is a left side view thereof, after the work piece has moved rearwardly under the nose panel and underneath the side skirts, showing the side skirts in a raised position;
[0024] FIG. 3C is a left side view thereof, showing the hood dropped down onto the work table with the side skirts still in a raised position, the forwardmost portion of the work piece having moved past the saw blade but not yet having cleared the side skirts; and
[0025] FIG. 3D is a left side view of the hood after the forwardmost portion of the work piece has cleared the side skirts, showing the side skirts returned to a lowered position.
[0026] FIG. 4 is a cross sectional view of the hood of FIG. 2A taken along the line 4 - 4 .
[0027] FIG. 5 is a left side elevational view of one side panel of the hood removed from the first embodiment of the hood.
[0028] FIG. 6 is a left side elevational view of one side skirt of the hood removed from the first embodiment of the hood.
[0029] FIG. 7 is a left side elevational view of a second, alternative embodiment of the hood, pivotally connected by parallelogram linkage to the splitter, and shown in a lowered, working position, resting on the work table;
[0030] FIG. 8 is a left side elevational view thereof in a raised, retracted position.
[0031] FIG. 9 is a perspective view of a rotary table saw as viewed from a position at the front, left of the saw, and showing the third embodiment of the movable, protective hood in a lowered, working position, and mounted by a collar joint to an overhead vacuum conduit assembly;
[0032] FIG. 10 is an enlarged, partial, left side perspective view, thereof, but with the hood in a raised, storage position;
[0033] FIG. 11 is a further enlarged, left side perspective view of the hood, showing the collar joint in phantom outline; and
[0034] FIG. 12 is an enlarged, perspective view of a rear portion of the same hood, after removal of the collar pin and disassembly of the collar joint;
[0035] FIG. 13A is an enlarged, partial, left side elevational view thereof, showing the hood in a lowered, working position;
[0036] FIG. 13B is an enlarged, partial, left side elevational view thereof, showing the hood partially raised by a work piece advancing toward, but not yet in contact with, a rotating saw blade;
[0037] FIG. 13C is an enlarged, partial, left side elevational view thereof, after the work piece has moved rearwardly under the nose panel and underneath the side skirts, showing the side skirts in a raised position;
[0038] FIG. 13D is an enlarged, partial, left side elevational view thereof, showing the hood dropped down onto the work table just after the forwardmost portion of the work piece has cleared the nose panel, and further showing the side skirts still in a raised position relative to the nose panel; and
[0039] FIG. 13E is an enlarged, partial, left side elevational view thereof, showing the work piece having advanced further rearward, entirely clearing the hood, and the side skirts having dropped back down onto the work table.
[0040] FIG. 14 is an exploded view of the collar joint and attached vacuum conduit assembly.
[0041] FIG. 15 is a left side view of the third embodiment of the hood, showing the head stock rotated up to a retracted position.
[0042] FIG. 16 is a left side view of the second embodiment of the hood attached by a parallelogram linkage and counterbalance to an overhead boom.
[0043] The terms “front” and “forward” will be understood to refer to portions of the hood and the table saw that are depicted on the right of FIG. 2A , and the terms “rear” and “rearward” refer to portions that are depicted on the left therein.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0044] Referring now to FIGS. 1, 2A , 2 B and 2 C, a movable, protective hood 10 , denoted generally by the numeral 10 , is shown in a working position directly over and straddling a rotary saw blade 12 mounted on a drive shaft 14 located below a flat, horizontal work table 16 of a rotary table saw 18 . An exposed, upper, peripheral portion 12 P of the saw blade 12 protrudes through a slot (not shown) in the work table 16 and, as denoted by arrow 22 , rotates forwardly toward a front edge 16 F of the work table 16 . The table saw 18 is equipped with a splitter 24 , shown in dashed outline, mounted to a rear portion 16 R of the work table 16 . The splitter 24 is aligned with, and disposed directly behind, the saw blade 12 . In this first embodiment of the hood, the hood 10 is pivotally mounted to the splitter 24 , as described below.
[0045] The hood 10 comprises a pair of spaced-apart vertical side panels 30 of identical size and shape, each side panel being longitudinally elongated from front to rear and having front and rear portions joined by an intermediate central portion, denoted as 30 F, 30 R, 30 C, respectively, as may best be seen in left side elevational view in FIG. 5 , wherein, for ease of reference, the defined portions are depicted as being divided one from the next by vertical dashed lines V. Each of the side panels 30 are relatively thin, flat, and of uniform thickness, as may be seen in FIGS. 2B and 2C . In this first embodiment, the rear portion 30 R is rectangular, being defined by a relatively long, lower edge 30 L and a relatively short, upper horizontal edge 32 , and by a relatively short, rear vertical edge 34 extending between terminuses 36 ′, 36 ″ of lower edge 30 L and upper edge 32 , respectively. The upper edge 32 extends forward about one-third the length of the lower edge 30 L from rear terminus 36 ″ to a front terminus 38 . In addition to lower edge 30 L, the central portion is defined by a substantially straight, upper edge 40 that is upwardly and rearwardly canted from the front portion 30 F, and defined further by a concave, forwardly and upwardly canted, rear edge 42 that extends from terminus 38 and intersects upper edge 40 at terminus 46 . The front portion 30 F extends generally forwardly of, and below, the lower edge 30 L. The front portion 30 F is defined by a straight, substantially vertical, rear edge 50 that extends downward from a forward terminus 52 of the lower edge 30 L to a lower terminus 54 ; a forwardly and upwardly canted nose edge 56 that extends from terminus 54 to a terminus 58 ; and a concavely curved upper edge 60 that extends rearwardly from terminus 58 to terminus 44 .
[0046] The hood 10 further comprises a forwardly and upwardly inclined nose panel 70 mounted between the front portions 3 OF of the side panels 30 adjacent the nose edges 56 and extending from terminuses 54 to 58 thereof. The nose panel 70 has a horizontal leading edge 72 extending laterally between terminuses 58 and a horizontal trailing edge 74 extending laterally between terminuses 54 . The trailing edge 74 is horizontally chamfered, as are the nose edges 56 adjacent terminuses 54 , to facilitate smooth, sliding contact with an upper surface of a work piece 15 when moved underneath the hood 10 in the direction of arrow 23 during a cutting operation; see FIG. 3A .
[0047] An upper cowl 80 is mounted between the side panels 30 , and extends rearwardly and upwardly from the front portion 30 F and over the central portion 30 C thereof. A front portion 80 F of the upper cowl 80 has a forward edge 82 that engages an upper surface of the nose panel 70 at a location intermediate between the leading and trailing edges 72 , 74 . The front portion 80 F extends upwardly from forward edge 82 and thence rearwardly to terminuses 44 . From terminuses 44 the central portion 80 C extends upwardly and rearwardly, adjacent upper edges 40 , to terminuses 46 .
[0048] A lower cowl 90 is mounted between the side panels 30 below the upper cowl 80 . The lower cowl 90 has a substantially vertical, front portion 90 F and a rearwardly extending, substantially horizontal, central and rear portion 90 C, 90 R, the front portion 90 F terminating in a horizontal, forward edge 92 disposed above the trailing edge 74 of the nose panel 70 . The combination of the side panel front portions 30 F, the nose panel 70 and the forward edge 92 of the lower cowl 90 define an orifice 110 to permit air and sawdust to stream away from the saw blade 12 and the situs of cutting S; see, for example, FIGS. 3A and 4 .
[0049] One each of a pair of vertical side skirts 120 of identical size and shape is suspended from an exterior surface of each of the side panels 30 , and is movable between a first, lowered position, as depicted, for example, in FIGS. 2A, 2C , 3 A, and 3 C, and a second, raised position, as depicted in FIG. 3B . Referring particularly to FIG. 6 , each side skirt 120 is a thin, flat panel of uniform thickness, elongated from front to rear, and defined by a substantially vertical rear edge 122 , a convex leading edge 128 , a straight, horizontal lower edge 120 L extending rearward from a lower end of the leading edge 128 to a lower end of the vertical rear edge 122 , and a substantially horizontal upper edge 126 extending rearward from an upper end of the leading edge 128 to an upper end of the rear edge 122 .
[0050] In this first embodiment, a parallel pair of horizontal, elongated, reinforcement struts 169 are attached to, and extend longitudinally along, opposite sides of an upper portion 24 U of the splitter 24 . Each of the struts 169 is made of metal, preferably aluminum. A parallel pair of equal-length, pivot arms 127 , are disposed on opposite sides of the pair of struts 169 . The arms 127 are also preferably aluminum. Each of the arms 127 has a first end pivotally attached to the splitter 24 by a first pivot pin 171 that extends laterally along an axis A-A through aligned apertures in said first ends, the splitter 24 and the struts 169 . Each of the arms 127 has an opposite, second end rigidly attached to a side panel 30 . Accordingly, the hood 10 may be rotated about lateral axis A-A between a raised, storage position and a lowered, working position.
[0051] For this first embodiment, each of the side skirts 120 has a slot 99 , which preferably is canted forwardly and upwardly at about 30 degrees declination from vertical. A preferred means for suspending each side skirt 120 from an adjacent side panel 30 includes a slot pin 101 attached to, and extending laterally outward from, a central portion of said side panel 30 and through said slot 99 . Each slot pin 101 has a retainer means for retaining the pin 101 within the slot 99 and for retaining a side skirt 120 adjacent to the nearest side panel 30 ; for this purpose, preferably each slot pin 101 has an internally threaded recess for receiving a round head bolt in threaded engagement therewithin, a retaining washer being interposed between the head of the bolt and an exterior surface of the side skirt 120 . The means 140 further includes stop means 103 attached to the side skirts 120 for limiting the extent of downward movement of the side skirts 120 when the hood 10 is raised away from the work table 16 . The stop means 103 preferably comprises a longitudinally-elongated barrier attached to an upper, rear edge 126 of each of the side skirts 120 and cantilevered laterally inward over the adjacent upper rear edges of the side panels 30 for abutting engagement therewith when the skirts 120 are in a lowered position.
[0052] The first embodiment of the hood 10 further includes a rear discharge wall 150 mounted between an upper surface of a central portion 90 C of the lower cowl 90 and the rear edge 159 of the upper cowl 80 , and between central portions 30 C of the side panels 30 . The rear discharge wall 150 has a centrally disposed hole 153 to permit air and sawdust to exit the hood 10 . A vacuum hose adapter 152 is attached to a rear surface of the rear discharge wall 150 and is aligned with the hole 153 therein. As shown in FIG. 1 , one end of a vacuum hose 200 attaches to the adapter 152 and an opposite end thereof attaches to a vacuum source, such as a shop vac 202 .
[0053] In a second, alternative embodiment of the hood 10 , as depicted in FIGS. 7 and 8 , the hood 10 is pivotally attached to the splitter 24 by a parallelogram linkage for movement between a raised, storage position ( FIG. 8 ) and a lowered, working position ( FIG. 7 ). The second embodiment includes a first parallel pair of equal-length, link arms 127 , disposed on opposite sides of the splitter 24 and the hood 10 . Each of the arms 127 has a first end pivotally attached to the splitter 24 by a first pivot pin 171 that extends laterally through aligned apertures in said first ends and the splitter 24 , and each of the arms 127 has an opposite, second end pivotally attached to a side panel 30 by a second pivot pin 173 . The second embodiment, however, further includes a second, parallel pair of equal-length link arms 170 disposed on opposite sides of the hood 10 and the splitter 24 ; each of the link arms 170 has a first end that is pivotally attached to a front portion 24 F of the splitter 24 by a third pivot pin 175 , and a second end pivotally attached to an inside surface of a side panel 30 below the lower cowl 90 by a fourth pivot pin 177 . Thus, the second pair of link arms 170 cooperate with the first pair of link arms 127 to form a parallelogram linkage of the hood 10 to the splitter 24 . A Optionally, a coil spring 61 is longitudinally mounted between the splitter 24 and a rear portion of the lower cowl 90 , to assist in raising the hood 10 away from the work table 16 . In the second embodiment, the means for suspending the side skirts 120 from the side panels 30 is modified from that of the first embodiment in two ways: first, each of the slots 99 A is made arcuate; second, said suspension means further includes a parallelogram linkage of each side skirt 120 to the adjacent side panel 30 . The parallelogram linkage of the side panels 30 to the adjacent side skirts 120 includes a first pair 151 and, longitudinally spaced-apart therefrom, a second pair 149 of parallel, equal-length, skirt support arms, the arms 151 , 149 of each pair being disposed on opposite sides of the hood 10 and pivotally attached to the side panels 30 and to the adjacent side skirts 120 . Preferably, each of the arms 151 , 149 is apertured, as are the side panels 30 , at each point of pivotal attachment, and each pivotal attachment is made by a fifth pivot pin 60 inserted therethrough.
[0054] In a third embodiment of the hood 10 , depicted in FIGS. 9-15 , the hood 10 is pivotally attached by a collar joint 201 to an overhead vacuum conduit assembly 199 . The conduit assembly 199 includes a vacuum source 202 connected to an electric power source (not shown), a laterally disposed, elongated, cylindrical, hollow boom 203 , and a hollow head stock 205 attached to one end of the boom 203 . A movable vacuum hose 200 within the boom 203 has a discharge end that terminates in a ring seal 197 and an opposite, intake end that is normally stored within the head stock 205 . The ring seal 197 has an outer diameter slightly less than the inner diameter of the boom 203 in order to maintain a vacuum throughout the interior of the boom 203 . The ring seal 197 is slidable within the boom 203 , its extent of travel being limited by a lock plate 153 P within the head stock 205 . A vacuum source 202 is attached to the discharge end of the boom 203 by a stationary hose 200 ′ that inserts into an annular seal 39 at said discharge end. An intake duct 206 extends from the head stock 205 part way toward the work table 16 . The interior of the intake duct 206 communicates with the interior of the head stock 205 and with the movable hose 200 therein. The intake duct 206 has a front wall 207 and a rear wall 208 joined by side walls 209 and terminates distally in an intake opening defined by the side walls 209 , a rear wall 208 , and a partially cutout, front wall 207 , such that distal portions of the side walls 209 form tab extensions 206 T of the intake duct 206 . A first, semicylindrical, partial collar 236 is mounted between the tab extensions 206 T of the intake duct 206 and is axially aligned on lateral axis A′-A′. The first partial collar 236 has front and rear openings 236 F, 236 R. The rear opening 236 R of the partial collar 236 is defined by the distal margins of the front and rear walls 207 , 208 of the intake duct 206 ; the front opening 236 F of the collar 236 is diametrically opposite to the rear opening 236 R. The collar joint 201 further includes a second, semicylindrical, partial collar 234 , coaxial with the first partial collar 236 , that partially surrounds and engages a forward portion of the first partial collar 236 . The second partial collar 234 is vertically disposed between a rear edge 157 of the lower cowl 90 and a rear edge 159 of the upper cowl 80 , and is laterally disposed between rear portions of the side panels 30 . A collar pin 237 , aligned on axis A′-A′, is inserted through apertures in the side panels 230 and through apertures 233 in the tab extensions 206 T of the intake duct 206 for rotatably mounting the second partial collar 234 to the first partial collar 236 and the intake duct 206 . The second partial collar 234 has an air discharge hole 235 that is in register with the front opening 236 F of the first partial collar 236 whenever the hood 10 is moved to a lowered, working position; whereas, whenever the hood 10 is moved to a raised, storage position, the second partial collar 234 covers over and closes off the front opening 236 F of the first partial collar 236 . Accordingly, when the hood 10 is in a lowered, working position, saw dust and wood chips are conducted from the situs of cutting S by an air stream (denoted by arrows 21 ) through the orifice 110 , rearwardly between the lower cowl 90 and the upper cowl 80 , thence through the discharge opening 235 of the second partial collar 234 , through the front and rear openings of the first partial collar 236 F, 236 R, through the intake duct 206 and vacuum hose 200 to a collection receptacle 202 . For directional control of larger particulates generated at the cutting situs S, preferably one or more forwardly and downwardly inclined deflector panels 223 are placed above the entrance to the orifice 110 , each of the deflector panels 223 being laterally disposed between the side panels 30 .
[0055] The boom 203 of the vacuum conduit assembly 199 includes a stationary portion 203 S and, in telescoping relation thereto, a laterally movable portion 203 M that carries, and communicates with, the head stock 205 . A rack and pinion assembly 238 , equipped with an adjusting knob 238 K, is attached to the stationary and movable portions of the boom 203 S, 203 M, respectively, to permit lateral adjustments of the position of the hood 10 with respect to the saw blade 12 and fence 161 . A lock knob 238 L inserted into threaded hole 238 H reversibly locks portion 203 M to portion 203 S. For storing the hood 10 in a raised position adjacent the head stock 205 , a spring catch 217 is mounted on the head stock 205 for insertion into a retainer aperture 219 in the nose panel 70 . A normally closed, momentary switch 221 , wired in series with the electric power source for the vacuum source, is attached to the head stock 205 adjacent to the spring catch 217 , such that, whenever the hood 10 is raised to the storage position adjacent the head stock 205 , the nose panel 70 depresses and opens the momentary switch 221 , thereby de-energizing the vacuum source. The head stock 205 is provided with a removable cap 205 C, whereby, with the cap removed, the intake end of the movable vacuum hose 200 may be withdrawn from the head stock 205 and used to vacuum clean the table saw 18 and its immediate environs, and thereafter replaced inside the head stock 205 .
[0056] The head stock 205 and the attached intake duct 206 may also be rotated about a horizontal axis between a lowered position, shown in FIGS. 9-15 , and a raised position, as shown in FIG. 16 . For this purpose, the head stock 205 has a circumferential slot 205 S and a lock mechanism 153 comprising a lock plate 153 P with an upstanding threaded shank that extends through the clot 205 S, and a locking handle 153 K with a threaded recess to receive the threaded shank.
[0057] The side panels 30 , side skirts 120 , upper cowl 80 , lower cowl 90 , and deflector panels 223 , may be made out of any suitably rigid, durable material, but a transparent material, such as polycarbonate or LEXAN® plastic, is preferred. It will be appreciated that various modifications can be made to the exact form of the present invention without departing from the scope thereof. As a first example, the stop means 103 could be attached to the side panels 30 or elsewhere on the hood 10 instead of attached to the side skirts 120 . As a second example, the hood 10 might be pivotally attached by a parallelogram linkage to an overhead boom equipped with a counterbalance mechanism in a manner well known to those having skill in the art, such as is depicted in FIG. 16 . Accordingly, it is intended that the disclosure be taken as illustrative only and not limiting in scope, and that the scope of the invention be defined by the following claims. | 4y
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CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 13/927,820, filed Jun. 26, 2013, now U.S. Pat. No. 8,652,584, which is a continuation of U.S. patent application Ser. No. 11/496,933, filed Jul. 31, 2006, now U.S. Pat. No. 8,475,886, and claims the benefit of U.S. Provisional Patent Application No. 60/705,908, filed Aug. 5, 2005, the entire contents of which are incorporated by reference herein.
FIELD OF THE INVENTION
[0002] The present invention relates to methods of treating plastic surfaces which resist non-specific protein binding or cell attachment, and surfaces prepared by same.
BACKGROUND OF THE INVENTION
[0003] Bare plastic surfaces, such as polystyrene surfaces, typically do not resist non-specific protein binding or cell attachment. Surfaces modified with a dense and stable layer of polymers such as polyethylene glycol or hydrogels, such as dextran, are known to resist non-specific protein binding and cell attachment. In the prior art, in order to create a dense and stable layer of protective polymers or hydrogels on a plastic surface, the plastic surface was typically treated with a photochemical reaction to activate the surface or with prior art specially designed chemicals that have a high affinity to the relevant surface.
SUMMARY OF THE INVENTION
[0004] A method is disclosed herein for treating a polymeric surface to resist non-specific binding of biomolecules and attachment of cells. The method includes the steps of: imparting a charge to the polymeric surface to produce a charged surface; exposing the charged surface to a nitrogen-rich polymer to form a polymerized surface; exposing the polymerized surface to an oxidized polysaccharide to form an aldehyde surface; and exposing the aldehyde surface to a reducing agent. Advantageously, a method is provided which produces surfaces that resist non-specific protein binding and cell attachment and that avoids the use of photochemical reactions or prior art specially designed compounds.
[0005] These and other features of the invention will be better understood through a study of the following detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
[0006] FIG. 1 is a flowchart representing a method in accordance with the subject invention.
[0007] FIG. 2 is a chart comparing the non-specific binding of Immunoglobin G (IgG) on two different surfaces: one surface is untreated and the other surface was treated by the subject invention. The amount of IgG bound on the surface was detected by the amount of IgG-HRP (horseradish peroxide) conjugate it could bind, and the amount of IgG-HRP conjugate was quantified by the HRP catalyzed oxidation of TMB (3,3′, 5,5′ tetramethylbenzidine), which changes color upon oxidation.
DETAILED DESCRIPTION OF THE INVENTION
[0008] With reference to FIG. 1 , a method 10 is depicted of treating a polymeric surface 12 to resist non-specific binding of biomolecules and attachment of cells.
[0009] In an initial step 30 , a charge is provided to the polymeric surface 12 of a vessel or receptacle to produce a charged surface 14 . The vessel may be of any known configuration, such as a test tube, vial, flask, etc. Preferably, the polymeric surface 12 is the surface of a multiwell plate. More preferably, the polymeric surface 12 is a surface of a well of a multiwell plate. It is further preferred that the multiwell plate conform to conventional multiwell plate standards (e.g., the Standards of the Society of Biomolecular Screening) so as to be usable in drug assay handling equipment (e.g., high throughput screening (HTS) equipment).
[0010] The term “polymeric surface” as used herein refers to any suitable such polymeric surface known to those skilled in the art. Suitable examples of polymeric surfaces include those obtained from polymeric hydrocarbons. As used herein, the term “polymeric hydrocarbon” is intended to refer to those polymers and copolymers obtained from repeating monomer units which are composed of carbon and hydrogen. The polymeric hydrocarbons may be saturated or unsaturated, and substituted or unsubstituted. Substituents may include atoms other than hydrogen and carbon, as long as they are present in an amount that does not detract from the substantially hydrocarbon nature of the polymer. Such substituents include acetal, halo, hydroxy, cyano, alkoxy, amino, amido, carbamoyl, and carbamido groups. Typical examples of a polymeric hydrocarbon surface include those made from substituted and unsubstituted polyethylene, polypropylene, polystyrene, ABS, PVC, polytetrafluoroethylene, polyvinylidene, and mixtures thereof. In a preferred embodiment, the polymeric hydrocarbon surface is polystyrene.
[0011] The term “polymeric surface” is also intended to include surfaces obtained from those polymers containing one or more heteroatoms such as oxygen, nitrogen, or sulfur, in addition to carbon and hydrogen. Typical examples of such polymeric surfaces include surfaces obtained from substituted and unsubstituted polyethers, polyesters, polyamides, polyamines, polyimines, polyurethanes, polyrureas, polyacetals, polycarbonates, polyacrylates, polysulfides, polysulfones, and polysulfides.
[0012] Also contemplated as being within the scope of the present invention are surfaces obtained from polymers with backbones composed significantly of heteroatoms, such as silicones.
[0013] Any known technique can be used to impart the charge to the polymeric surface 12 to produce the charged surface 14 . Preferably, plasma treatment or corona discharge treatment may be utilized. With this process, a charge is imparted to the polymeric surface 12 by disposing the polymeric surface 12 into a substantially gas-free chamber, introducing a gas into the chamber, and exciting the gas. As a result, plasma is formed and applied to the polymeric surface 12 to produce the charged surface 14 . A high-frequency generator may be used to ionize the gas into a plasma. In addition, the plasma may be generated using conventional plasma conditions such AC or DC power levels up to about 200 watts, radiofrequency (RF) excitation of about 0.1 to about 50 megahertz, for a durations of about 0.1 to about 30 minutes, with a gas pressure of about 0.1 to about 3.0 Ton. A conventional plasma chamber may be used, although it is preferred that the chamber be evacuated during use.
[0014] Although an RF excited plasma is preferred, any other method of generating a gas plasma may be used, for example a glow discharge or a corona discharge. For example, microwave frequencies may be employed instead of, or in addition to, RF excitation.
[0015] Gases typically used with plasma treatment and introduced into the plasma chamber include Ar, He, Ne, He, He/H 2 , O 2 , N 2 , NH 3 , and CF 4 . In one embodiment of the invention, the charged surface 14 may be negatively charged. A negatively charged surface is specifically designated with reference numeral 14 ( a ) in FIG. 1 . Preferably, oxygen gas is used in the plasma treatment process to produce the negatively charged surface 14 ( a ).
[0016] Alternatively, in another embodiment, the charged surface 14 may be positively charged. A positively charged surface is specifically designated with reference numeral 14 ( b ) in FIG. 1 . Preferably, ammonia gas is used in the plasma treatment process to produce the positively charged surface 14 ( b ). Specifically, subjecting the polymeric surface 12 to ammonia gas plasma treatment creates a number of nitrogen containing, positively charged functional groups on the surface, providing the positively charged surface 14 ( b ).
[0017] In a next step 32 of the method 10 , the charged surface 14 is exposed to a nitrogen-rich polymer to form a polymerized surface 16 . The negatively charged surface 14 ( a ) may be exposed to the nitrogen-rich polymer without any intervening steps. However, before the positively charged surface 14 ( b ) may be exposed to the nitrogen-rich polymer, the positively charged surface 14 ( b ) is preferably first exposed to one or more suitable linkers. A variety of linkers, commonly referred to as “cross-linkers” may be used. Suitable linkers include: dialdehydes, diesters, diimidoesters, NHS-esters, hydrazides, carbodiimides, and aryl azides. Also contemplated as being within the scope of the invention are heterobifunctional linkers, i.e. those which have different functional groups on each end. For example, a suitable heterobifunctional linker would be one having an ester on one end and an aldehyde on the other end. In a preferred embodiment, the linker is a dialdehyde having the structure:
[0000]
[0018] wherein R 1 is a C 2 to C 30 alkylenyl. In a more preferred embodiment, the dialdehyde is glutaraldehyde.
[0019] Preferably, the positively-charged surface 14 ( b ) is exposed to a solution of the linkers. Any suitable solvent or suitable mixture of solvents known to those skilled in the art may be used with the linkers. Suitable solvents include water, buffers, methanol, ethanol, isopropanol, and dimethylsulfoxide (DMSO).
[0020] Once readied, the charged surface 14 is exposed to a nitrogen-rich polymer to form the polymerized surface 16 . The term “nitrogen-rich” is intended to refer to polymers bearing pendant amino groups such as N(R 2 ) 2 and ═NR 2 , wherein each R 2 is independently H or C 1 to C 10 alkyl. As used herein, the term “alkyl” intended to refer to branched and straight-chained saturated aliphatic hydrocarbon radicals having the indicated number of carbon atoms. Alkyl groups may be unsubstituted, or substituted. Suitable substituents include C 1-5 alkyl, amino, amido, cyano, carbamoyl, phenyl, heteroaryl, halogen, C 1-5 alkoxy, C 1-5 alkyl-C(O)H, CO 2 H, and CO 2 -C 1-5 alkyl. The term “alkylenyl” is intended to encompass diradical variations of alkyl groups.
[0021] Preferably, the nitrogen-rich polymer is a polyalkylenimine such as polyethylenimine. Another class of nitrogen-rich polymers suitable for the present invention is polymeric amino acids. The term “polymeric amino acid” is intended to refer to a string of repeating amino acids. Accordingly, any suitable peptide may be used as a nitrogen-rich polymer. The string of amino acids may contain a string of identical amino acids or a string of different amino acids, and in either case may be natural or man-made. Nitrogen-rich polymers based on amino acids such as lysine and arginine possess sufficient nitrogen character so as to be good examples of suitable nitrogen-rich polymers. A synthetic polymeric amino acid particularly useful in the present invention as a polymeric amino acid is poly-lysine. In a more preferred embodiment, the synthetic polymeric amino acid is poly-d-lysine.
[0022] Typically, the charged surface 14 will be exposed to a solution of the nitrogen-rich polymer, forming the polymerized surface 16 . Any suitable solvent or suitable mixture of solvents known to those skilled in the art may be used. Suitable solvents include water, buffers, methanol, ethanol, isopropanol, and dimethylsulfoxide (DMSO).
[0023] In the next step 34 , the polymerized surface 16 is exposed to an aldehyde-bearing polymer, thereby providing aldehyde surface 18 . Any polymer bearing pendant hydroxyalkyl groups can serve as the aldehyde-bearing polymer. Preferably, the alcohols on such a polymer are oxidized to aldehydes, with the aldehydes being receptive to coupling with both the nitrogens of the polymerized surface 16 and the nitrogens of an outer layer discussed below. However, because the aldehyde surface 18 must be biologically benign, it is preferred that the alcohol-bearing polymer not be toxic to biological or cell cultures. Preferably, the aldehyde-bearing polymer is an oxidized polysaccharide in which the pendant alcohol groups have been converted to aldehyde groups. Suitable oxidized polysaccharides include oxidized polysaccharides such as oxidized amylose, oxidized amylopectin, oxidized cellulose, oxidized chitin, oxidized guaran, oxidized glucomannan, and oxidized dextran. Among these, oxidized dextran is particularly preferred. In a preferred method, the polysaccharides are oxidized by adding sodium m-periodate (NaIO 4 ) to the polysaccharide solution, with the resulting solution being incubated at room temperature in the dark for 4 hours, followed by removal of the sodium m-periodate (e.g., by dialysis).
[0024] Typically, the polymerized surface 16 will be exposed to a solution of the aldehyde-bearing polymer to form the aldehyde surface 18 . Any suitable solvent or suitable mixture of solvents known to those skilled in the art may be used. Suitable solvents include water, buffers, methanol, ethanol and isopropanol.
[0025] The aldehyde surface 18 is further treated, as shown in step 36 , which may involve one step or two sub-steps, in forming a stabilized surface 20 .
[0026] In one embodiment, the polymerized surface 18 may be exposed to a reducing agent, thereby producing the stabilized surface 20 , specifically designated for this embodiment as stabilized surface 20 ( a ) in FIG. 1 . Preferably, the reducing agent is a boron-based reducing agent such as NaBH 4 or NaCNBH 3 .
[0027] Alternatively, in another embodiment, the polymerized surface 18 is first exposed to an amine-terminated polymer. Preferably the amine-terminated polymer is an amine-terminated hydrocarbyl polymer or an amine-terminated polyether. The term “hydrocarbyl polymer” is intended to be synonymous with the term “polymeric hydrocarbon” as discussed hereinabove. In a more preferred embodiment, the amine-terminated polyether is amine-terminated polyethylene glycol. Typically, the amine-terminated polymer will be dissolved in suitable solvent when exposed to polymerized surface 18 . Any suitable solvent or suitable mixture of solvents known to those skilled in the art may be used. Suitable solvents include water, buffers, methanol, ethanol and isopropanol.
[0028] Reaction of the aldehyde surface 18 and the amine groups of the amine-terminated polymer forms a reversible Schiff base linkage which can then be stabilized with a suitable reducing agent, thereby producing stabilized surface 20 , specifically designated for this embodiment as stabilized surface 20 ( b ) in FIG. 1 . The suitable reducing agent is as described above with respect to the stabilized surface 20 ( a ).
EXAMPLES
Example A
[0029] A polystyrene surface is exposed to oxygen gas plasma treatment, creating a negatively charged surface. The negatively charged surface is exposed to a solution of 1% polyethylenimine for 2 hours. The polyethylenimine coated surface is exposed to a solution of 10 mg/mL oxidized dextran for two hours. The dextran coated surface is exposed to a solution of amine-terminate polyethylene glycol for 1 hour. The polyethylene glycol surface is exposed to a solution of 1 mg/mL sodium borohydride for 1 hour.
Example B
[0030] A polystyrene surface is exposed to ammonia gas to create a positively charged surface. The positively charged surface is exposed to a solution of 10% glutaraldehyde for 1 hour. The glutaraldehyde activated surface is exposed to a solution of 1% polyethylenimine for 2 hours. The polyethylenimine coated surface is exposed to a solution of 10 mg/mL oxidized dextran for 2 hours. The dextran coated surface is exposed to a solution of 1 mg/mL amine-terminated polyethylene glycol for 1 hour. The polyethylene glycol coated surface is exposed to a solution of 1 mg/mL sodium borohydride for 1 hour.
[0031] As will be appreciated by those skilled in the art, the subject invention provides polymeric surfaces which will resist non-specific binding of biomolecules and attachment of cells. The stabilized surface 20 provides such resistance. With reference to FIG. 2 , data is presented relating to the non-specific binding of IgG on two different surfaces: surfaces not treated by the method of the subject invention and surfaces which have been treated by the subject invention. In this demonstration, a 96-well polystyrene plate was treated using the method of Example A. Another 96-well polystyrene plate was not treated and was used as a reference. The surfaces in the wells of both of the plates were brought into contact with 5 μg/mL of anti-mouse IgG for 2 hours followed by washing with PBS (phosphate buffered saline). Then the surfaces were brought into contact with mouse IgG-HRP (horseradish peroxide) conjugate (concentration ranges from 0.01 μg/mL to 0.33 μg/mL) for 1 hour followed by washing with PBS. Thereafter, the surfaces were brought into contact with TMB (3,3′, 5,5′ tetramethylbenzidne) solution for 8 minutes followed by adding 2N HCl to stop the reaction. The amount of anti-mouse IgG and the associated mouse IgG-HRP conjugate bound on the surfaces was quantified by the intensity of the color (detected at 450 nm) produced by the oxidized TMB. As can been seen in FIG. 2 , negligible amounts of Immunoglobin G were absorbed by the treated surfaces.
[0032] Experiments have been conducted relating to the attachment of various types of adherent cells on two different surfaces: surfaces not treated by the method of the subject invention and surfaces which have been treated by the subject invention. In the following described experiments, a 6-well polystyrene plate was treated using the method of Example A. Another 6-well polystyrene plate was untreated and used as a reference.
[0033] In a first experiment, HT-1080 (human fibrosarcoma cell line) cells were cultured on both untreated and treated surfaces of 6-well plates under the same culture condition (incubation at 37° C. in growth media). Cell attachment and spreading on the surfaces were analyzed and microscopic images were taken following several days of cell culture. The HT-1080 cells attached to the untreated surface and spread on the surface as expected. However, the HT-1080 cells remained un-attached to the treated surface and formed cell aggregates floating in the media. The treated surface remained free of cells after removing the media, demonstrating the ability of the treated surface for resisting HT-1080 cell attachment.
[0034] In a second experiment, mouse embryo fibroblasts (NIH/3T3) were cultured on both untreated and treated surfaces of 6-well plates under the same culture condition (incubation at 37° C. in growth media). Cell attachment and spreading on the surfaces were analyzed and microscopic images were taken following several days of cell culture. The fibroblasts attached to the untreated surface and formed a monolayer on the surface as expected. However, the fibroblasts remained un-attached to the treated surface and formed cell aggregates floating in the media. The treated surface remained free of cells after removing the media, demonstrating the ability of the treated surface for resisting fibroblast attachment.
[0035] In a third experiment, canine chondrocytes were cultured on both untreated and treated surfaces of 6-well plates under the same culture condition (incubation at 37° C. in growth media). Cell attachment and spreading on the surfaces were analyzed and microscopic images were taken following several days of cell culture. The chondrocytes attached to the untreated surface and spread on the surface as expected. However, the chondrocytes remained un-attached to the treated surface and formed cell aggregates floating in the media. The treated surface remained free of cells after removing the media, demonstrating the ability of the treated surface for resisting chondrocyte attachment.
[0036] Experiments have been conducted relating to the formation of embryoid bodies from embryonic stem cells. The formation of embryoid bodies was successfully achieved using the 6-well polystyrene plates treated by the method of the subject invention. Untreated 6-well polystyrene plates were used as controls and embryoid bodies did not form due to the attachment of embryonic stem cells to the untreated surfaces during the long incubation time (up to 7 days). With the treated surfaces, attachment of the embryonic stem cells was generally avoided, and the embryonic stem cells remained in suspension during incubation. As such, without attachment, the embryonic stem cells generally avoided attachment-mediated differentiation, thereby permitting later enhanced embryoid body formation.
[0037] The subject invention may have applicability in various contexts. By way of non-limiting examples, the subject invention can be used to prepare polymeric surfaces to obtain the following advantages: maintaining cells in solution in suspended, unattached states; preventing stem cells from attachment-mediated differentiation; permitting enhanced formation of embryoid bodies from embryonic stem cells; preventing anchorage-dependent cells from dividing; reducing binding of serum proteins; and, enhancing signal-to-noise ratios in homogenous assays, such as Scintillation Proximity Assays. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to improvements to heat insulating means for piping subjected to stresses, whether they are thermal, hydrostatic and/or mechanical and the positioning of these insulating means on said piping; it further relates to processes for forming these new insulating means.
2. Description of the Prior Art
In offshore oil fields, the production wells are connected to a production platform or to a subsea collector by underwater ducts disposed on the sea bed. It is usual for a production platform (which provides a first treatment of the crude oil) to be connected to several wells, the number thereof depending on a great number of parameters such as the size and yield of the field, depth of water, etc. . . .
The oil leaves these production wells at a variable temperature (70° to 95° C.) sufficient, in any case, for it to flow into the drilling tube.
When it is a question of light oil, it is then brought to the platform by a conventional metal undersea duct and arrives at the production platform at a temperature, which is variable depending on the length of the pipe, between that of the well head and that of the water in the immediate neighborhood of the duct.
Furthermore, in so far as transporting heavy high viscosity oils or paraffin oils by a metal duct is concerned, the oil conveyed by this duct will be progressively brought to the temperature of the sea water. At a certain distance from the well it will become too viscous or solid deposits will appear causing clogging of the duct. It is obvious that the critical distance for the appearance of this phenomen will be all the smaller the lower the temperature of the sea water and, consequently, the greater the depth at which the duct is located.
The problem also arises for gas pipe lines between the wells and the platform where a considerable lowering of the temperature of the gas causes the formation of hydrates and progressive clogging of the duct.
The need for heat insulating the piping so as to protect it as much as possible from the adverse effects of the low temperatures of the sea environment has therefore become imperative for the operators of "offshore" platforms, so as to reduce as much as possible the temperature gradient of the crude oil between its ouput from the drilling well and its arrival at the production platform, so that it remains low, of the order of 5° to 30° C.
The solution proposed in the prior art for providing insulation of underwater piping of this type, is shown by the arrangement of an outer metal sheath which surrounds the remote crude oil collecting pipe line, the gap between the inner collecting piping and the outer metal sheath being filled with a heat insulating material formed from polyurethane foam. However, this solution has considerable drawbacks both in the economical and in the technological spheres. In fact, whereas the inner collecting piping must withstand the internal pressures developed by the flow of crude oil at a relatively high temperature, the outer sheath must withstand hydrostatic crushing pressures to which the sea environment on the sea bed subjects it, so that it must be made from steel and have a relatively high thickness, adapted for withstanding the high pressures to which it is subjected, so that it is very expensive.
The polyurethane foam injected in situ is relatively unresistant to the high hydrostatic pressures which prevail at the bottom of the sea, so that should the outer metal sheath be accidently perforated, the insulating polyurethane foam is destroyed both by the hydrostatic pressure which it must then withstand directly and without protection and by the sea environment which hydrolyses it; injection takes place without the possibility of checking the quality of the insulation formed, so that it may have uncontrolled and uncontrollable insulating defects.
Furthermore, the outer sheath may comprise solutions of continuity or gaps for welding the successive adjacent tubes on the barge, so as to form the heat insulated collecting pipe line desired; it is then neccessary to leave, in the vicinity of the adjacent junction ends of two successive tubes, a non insulated gap of about 40 cm so as to allow welding; after welding the ends of the tubes to each other, the gap between two sheath sections is made up by positioning a sleeve which is welded to the ends of two adjacent sheath sections, so as to obtain a continuous outer sheath, while leaving however an orifice for the in situ injection of the heat insulating polyurethane foam, which orifice is then closed by a welded plug. So as to prevent any alteration of the insulating material by the temperatures used for welding, during the plug welding operation, it is necessary to protect the insulating material by interpositioning asbestos rings.
The operations for positioning the sheath sections about the inner tubes, welding the adjacent ends of the successive inner tubes together, positioning and welding sleeves in the gaps between the adjacent sheath sections, injecting the insulating polyurethane foam in situ and welding so as to close the injection orifices formed in the welded joins between the sleeves and the sheath sections, with interpositioning of asbestos rings, must furthermore necessarily be carried out on the barge before lowering the piping with its insulating device, to the sea beds on which it is to be laid. The time during which the barge is immobilized on the site is therefore relatively long before the insulated piping effectively connects a drilling well to a production platform, and greatly increases the cost price for laying such heat insulated piping.
It has also been proposed in the prior art to provide piping for transferring the crude oil from the wells to the offshore production platform with an outersheath formed by a tube made from a rigid plastic material such as PVC or polyethylene, the gap between such an outer sheath and the piping being filled with a heat insulating material such as polyurethene foam.
However, this solution is not satisfactory either for the resistance of the outer rigid PVC or polyethylene sheath is insufficient with respect to the hydrostatic crushing pressures which reign in the sea at great depths, more especially greater than 50 meters; in addition, the jointing operations are just as complicated as in the case where the outer sheath is made from steel; furthermore, for laying, repairing and facing up to the consequences of possible damage, problems are met with similar to those which have been set forth above in connection with the heat insulating system formed by polyurethane foam interposed between the piping and the outer rigid plastic material sheath.
SUMMARY OF THE INVENTION
The present invention therefore provides means for heat insulating piping subjected to considerable thermal, hydrostatic and mechanical stresses which answer better the requirements of practice than the heat insulating means proposed by the prior art for the same purpose, more especially in that they allow very rapid joining, on the barge, not only of successive tubes for forming a pipe line, but also insulating means associated with the tubes for filling the gaps between the adjacent tubes to be joined together, in that the heat insulating means have not only excellent insulating properties, but also an excellent resistance to the hydrostatic crushing pressures to which they are subjected on the sea bed, in that, because of the speed of the jointing operations, the barge is immobilized on the laying site for a shorter time, thus considerably reducing the costs involved in positioning piping on the sea bed, in that the heat insulation of the invention is sealed and resistant to the sea environment, so that it is not likely to cause an accidental inrush of sea water and practically does away with the risks of damage related to such an accidental inrush and in that local repairs which the heat insulation may possibly require are relatively easy to carry out because the risk of said insulation being swamped by sea water has been eliminated.
The present invention relates to a heat insulating means for piping subjected to high thermal, hydrostatic and mechanical stresses, comprising a plurality of sectors made from a foam insulating material enclosing air, which sectors or layers are bonded together by foils or layers of elastomer, which have been cured at a temperature less than or equal to 120° C.
In an advantageous embodiment of the insulating means of the invention, the insulating material is formed by rigid PVC foam having closed cells. In another advantageous embodiment of the insulating means of the present invention, the insulating material is a syntactic material formed by spheres of PVC foam having closed cells coated with an epoxy resin based matrix whose thermal conductivity is lowered by the addition of glass microballs.
In yet another advantageous embodiment of the insulating means of the present invention, the insulating material is formed by a syntactic material comprising glass microballs and plastic material balls embedded in an epoxy resin matrix.
In yet another advantageous embodiment of the insulating means of the present invention, the elastomer used as shock absorbing material and at the same time as bonding material for the layers or sectors of insulating material is rubber lightened by glass microballs which are embedded in a rubber matrix.
In yet another advantageous embodiment of the thermal insulating means of the present invention, they are formed by an insulating laminated material which is formed from a plurality of layers of a foam insulating material enclosing air and rubber layers, which laminate is homogeneous, unpeelable, sealed, resistant to high hydrostatic pressures, resistant to corrosion, to abrasion and to shocks.
In an advantageous arrangement of this embodiment, the foam insulating material from which the insulating material layers are formed is rigid PVC foam with closed cells.
In another advantageous arrangement of this embodiment, the foam insulating material from which the insulating material layers are formed comprises balls of PVC foam with closed cells incorporated in an epoxy resin based matrix, or is formed from an epoxy resin matrix in which the glass microballs and balls made from an appropriate plastic material are embedded.
In yet another advantageous arrangement of this embodiment, the external layers of the laminate are rubber or lightened rubber layers.
According to another advantageous embodiment of the thermal or heat insulating means of the present invention they are formed by sectors made from an insulating material bonded together by elastomer foils.
The present invention also relates to a device for the heat insulation of undersea ducts subjected to high thermal, hydrostatic and mechanical stresses which comprises, in combination: a first elastomer layer which surrounds the duct to be insulated and thus ensures the anti corrosion protection thereof; the heat insulating means such as defined above, superimposed continuously on said first layer; a second elastomer layer, sea water tight and abrasion resistant, which surrounds the heat insulating means, said insulating layers and means protect each tube of a duct to the exclusion of the ends thereof, which are left without protection so as to allow the adjacent tubes to be welded together end to end; a rapid and sealing jointing means for the insulating devices of two adjacent tubes, formed by a ring or shells prefabricated from elastomer which may incorporate elements of a material which is thermally insulating and resistant to the hydrostatic pressure, after welding of the metal tubes, in the corresponding end zones of said tubes, not comprising any insulating devices, and fixed to the adjacent insulating devices of said tubes by means of a sealing elastomer or similar more especially a self curing elastomer, so as to reconstitute the continuity of the insulation of the ducts, or of a heat retractable sheath.
In an advantageous embodiment of the jointing means of the invention, they are formed by a longitudinal split elastomer ring or by two elastomer half shells, the ring or the half shells being reinforced by means of a foam material strip for limiting the heat flow in said jointing device.
In another advantageous embodiment of the jointing means of the present invention, they comprise metal inserts for hooking or fastening said jointing means.
In an advantageous arrangement of this embodiment, the metal inserts are fitted into said elastomer ring so as to be solid on the one hand with the first elastomer anticorrosion layer and on the other with said elastomer ring.
In yet another advantageous embodiment of the jointing means of the invention, the sealing elastomer which interconnects the jointing means with the adjacent heat insulating devices mounted on successive tubes welded axially one to another, is provided at least in the welded zone, without insulating devices, of the ducts, and a sheath made from a material adapted for exerting on the sealing elastomer a compression force for further improving the bonding and plugging properties of said elastomer on the adjacent ends of the successive welded tubes, initially deprived of any insulating device.
In yet another advantageous embodiment of the jointing means of the invention, the external zone where the elastomer jointing ring is secured to the adjacent heat insulating devices is protected by a sealed protecting sheath adhering to said zone.
In a further advantageous embodiment of the heat insulating device of the present invention, the first anti corrosion elastomer layer and the second sealed protecting elastomer layer form an integral assembly with the heat insulating means.
The present invention further provides a process for positioning such a heat insulating and sealed jointing device for adjacent heat insulation devices, on ducts or piping formed by metal tubes welded end to end, wherein an elastomer layer, intended to protect the surface of the metal tubes which are to form the undersea ducts to be insulated from corrosion, is positioned on the outer surface of said tubes, by any appropriate means and more especially by winding or "taping" so as to leave the ends of said tubes free over a short distance; -then a heat insulating means comprising a plurality of sectors or layers made from a foam insulating material enclosing air, bonded together by means of elastomer foils or layers, which heat insulating means has, prior to its positioning, been subjected to low temperature curing, lower than or equal to 120° C., for curing the elastomer bonding foils or layers, is positioned by any appropriate means on the elastomer layer protecting against corrosion; a second insulating elastomer layer is positioned, by any appropriate means, and more especially by winding or "taping" on the above mentioned heat insulating means--and, after the successive metal tubes have been welded end to end, the welding zone, deprived of heat insulating devices, of said tubes is filled so as to ensure the continuity of the heat insulation over the whole of the length of the duct, by using a jointing means formed preferably by a prefabricated ring or sectors made from elastomer in which strips of a foam insulating material enclosing air are incorporated, whose purpose is to limit the heat flow, which jointing means is sealingly fixed, on the one hand, to said welding zone and to the ends of the anticorrosion elastomer layer of the insulating means carried by two adjacent welded tubes, by means of a self curing elastomer, or mastic, and on the other hand to the bonded elastomer walls which encapsulate the heat insulating material of the heat insulation means.
In a preferred embodiment of this process, the self curing elastomer which provides sealed bonding of the jointing means in said welding zone, is associated with a sheath made from a material capable, under certain conditions, of exerting compression forces on said elastomer, which improve its bonding and sealing properties.
In another preferred embodiment of this process, the outer jointing zone of the means for jointing adjacent heat insulating devices together is protected by a sheath made from a material capable, under some conditions, of exerting compression forces of said zone so as to improve the bonding and sealing properties of the self curing elastomer which fixes the ends of the jointing means to the corresponding ends of the adjacent heat insulation devices.
In yet another preferred embodiment of this process, the jointing ring is provided with metal hooping inserts.
In yet another preferred embodiment of this process, the jointing ring is provided with metal inserts for fixing said ring to the heat insulating device, which meal inserts are fixed, by stapling, clipping or similar, to the anti corrosion elastomer layer of the heat insulating device.
In yet another preferred embodiment of this process, the anti corrosion elastomer layer and the insulating elastomer layer which cover the heat insulating means form an integral part of said means, that is to say that they form one therewith.
In a preferred embodiment of the process of the invention, the heat insulating means is formed by a laminate which is formed from a plurality of layers of a foam insulating material enclosing air, bonded together by elastomer foils which are curable at a temperature less than or equal to 120° C., which laminate may comprise outer elastomer layers bonded to the insulating material layers and which play respectively the role of anti corrosion layer and external sealing and protection layer during positioning of said laminate on a tube to be insulated, and said laminate is wound on the tube to be insulated with an appropriate pitch.
In an advantageous arrangement of this embodiment, a plurality of strips of a foam insulating material enclosing air is formed by winding with a pitch such that there is provided between two successive strips a free space in which the bonding elastomer is inserted, such a laminate having very great flexibility which depends on the width of the gap which separates the two consecutive turns.
In another preferred embodiment of the process of the invention, the heat insulating means are formed by a plurality of sectors made from a foam insulating material enclosing air bonded together radially or laterally by means of an elastomer layer.
Whether in the form of a laminate or sectors bonded together by elastomer, the heat insulating means are advantageous prefabricated for fitting onto each of the tubes to be insulated, while leaving the ends thereof free of any heat insulating means, for welding them to adjacent tubes.
In yet another preferred embodiment of the process of the present invention, the jointing means are formed by a prefabricated elastomer ring obtained by molding.
In another preferred embodiment of the process of the present invention, the elastomer ring which forms the jointing means is obtained by successively winding, on a mandrel, strips of a foam insulating material enclosing air and elastomer strips, then curing the assembly at a temperature less than or equal to 120° C.
In yet another preferred embodiment of the process of the present invention, the jointing means are fixed to the welded zones of the tubes, with out heat insulating devices, by a self curing elastomer which is provided with a retractable material sheath, made more especially from heat retractable polyethylene, which in the retracted state, exerts compression forces on the self curing elastomer which are such that this latter adheres strongly on the one hand to the underlying welding zone and on the other to the anti corrosion elastomer layers which surround said welding zone, so as to anchor the jointing means.
The present invention relates more particularly to the means and devices for thermally insulating piping, in accordance with the preceding arrangements, the devices for jointing said heat insulating means, as well as the processes for producing same, the processes for positioning same and the piping thermally insulated by using the heat insulating and jointing devices and means of said insulating devices.
Besides the above arrangements, the invention further provides other arrangements which will be clear from the following description.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from the following complement of description which refers to the acompanying drawings in which:
FIG. 1 shows schematically a heat insulating device according to the invention, seen in partial longitudinal section, mount on a tube to be insulated;
FIGS. 2, 3, 5 and 7 show the embodiments of heat insulating devices in accordance with the present invention in partial schematical cross sectional views;
FIG. 4 is a partial longitudinal sectional view of a jointing means positioned in the welding zone of two tubes welded end to end and fixed to the adjacent insulating devices carried by the two tubes;
FIG. 6 shows a partial longitudinal sectional view of a means for securing the jointing means of the invention with an adjacent insulating device, and
FIG. 8 is a partial longitudinal sectional view of a heat insulating device in accordance with the invention.
It should however be understood that these drawings and the corresponding descriptive parts are given solely by way of illustration of the subject of the invention, of which they in no wise form a limitation.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The heat insulating device in accordance with the invention comprises an elastomer layer 2 whose purpose is to protect the metal tube 1 to be insulated from corrosion, a layer 3 made from a foam insulating material enclosing air and a second elastomer layer 4 which protects the insulating material layer 3.
Preferably, the elastomer used for forming layers 2 and 4 is, for example, polychloroprene which, is applied in layers of five to seven millimeters and seven to ten millimeters in thickness, respectively, on the one hand on tube 1 and on the other on the insulating layer 3. The insulating device designated generally by the reference 10 in FIG. 1 may be formed in different ways: it may be formed by insulating material sectors 5 bonded together by rubber 6 (see FIGS. 2, 5 and 7), or by a laminate comprising sheets 7 of an insulating material bonded together by thin rubber sheets 8 (see FIGS. 3 and 8). In particular, the insulating device is formed by winding insulating material sheets whose thickness is of the order of 5 to 8 mm, bonded together by rubber sheets from one to two millimeters in thickness.
The heat insulating means are preferably formed by sectors 5 or sheets 7 of rigid polyvinyl chloride foam with closed cells or from syntactic material comprising polyvinyl chloride foam spheres encased in an epoxy resin based matrix or comprising glass microballs associated with plastic material balls embedded in the epoxy resin.
The insulating material formed by sectors 5 or sheets 7 bonded together by rubber of a similar elastomer is cured, before positioning about tubes 1, at a temperature less than or equal to 120° C., preferably between 80° and 100° C., which the insulating material withstands well (and particularly "KLEGECELL"), and provides a homogeneous cured product, withstanding high pressures, which does not peel and which has excellent heat insulating properties while withstanding well the hydrostatic pressures of the surrounding sea environment, which are themselves transmitted to the metal tube to be insulated.
The elastomer for bonding together elements 5 or 7 which form the heat insulating means is preferably rubber of any composition, appropriate for the desired purpose. However, a bonding rubber may be used formed from a lightened rubber in which glass microballs are embedded in rubber.
In the variant shown in FIG. 5, a layer 9 of rubber lightened by glass microballs is inserted between the anti corrosion elastomer layer 2 and the insulating material layer 5 or 7, the purpose of this layer 9 being to improve the resistance of the heat insulating means of the invention to temperatures greater than 80° C. of the fluids which flow in the ducts.
As shown in FIG. 1, the heat insulating device 10 is placed about a metal tube 1 to be insulated so that the anti corrosion elastomer layer 2 leaves the ends 11 of said tube 1 free over a length of about 30 cm (with respect to a length, for example of 12 m for the tube) so as to allow subsequent welding together of the metal tubes placed end to end.
After end to end welding of two adjacent tubes 1, the welding zone 12 without heat insulating device defines, with the corresponding ends 13 of the heat insulating means of the invention, an empty space 14 intended to receive a jointing means which comprises an elastomer ring 15 in which is included at least one strip 16 of the above mentioned insulating material such as "KLEGECELL" more particularly, whose role is to limit the thermal flow.
Ring 15 is advantageously prefabricated and may be formed by molding or successively and alternatively winding insulating material 16 and rubber strips (of FIG. 8). Ring 15 is advantageously split longitudinally.
Fixing thereof in space 14 is preferably achieved by using a layer 17 of butyl mastic or a similar self curing rubber, which provides adherence and sealing of ring 15 at the corresponding ends 13 of the adjacent heat insulating devices which define space 14 with the welding zone 12. Fixing of the internal face of ring 15 in the welding zone 12 and on the ends of the elastomer layer 2 is preferably achieved by means of a butyl mastic layer 18 having a retractable polyethylene sheath 19 which retracts under heating and creates compression forces which are exerted on the butyl mastic 18 for reinforcing its adherence and sealing properties.
In addition, a sealing and protecting sheath 20, preferably made from retractable polyethylene or from another material capable of exerting a compression effort in the jointing zones 21-22, is applied to the zones 21-22.
In the embodiment shown in FIG. 4, metal inserts 23 ensure hooping of ring 15.
In the embodiment shown in FIG. 6, the metal inserts comprise a hook shaped part 24 which is integral with the anti corrosion elastomer layer 2 and a part 25 integral with ring 15, parts 24 and 25 each comprising a groove which face each other, the two grooves where joined together forming the channel 26 which is filled with butyl mastic 27 so as to firmly secure together the metal insert parts 24 and 25 and to fix ring 15 in position in space 14.
The heat insulating device according to the present invention may be fitted, either in the factory or on the barge, onto the tubes to be insulated and the prefabricated jointing means may be mounted and fixed very rapidly, after end to end welding of adjacent tubes on the barge, for example within five to seven minutes, because of the design of these devices and means.
The heat insulating device according to the present invention, besides withstanding high hydrostatic pressures, as was mentioned above, because of its outer elastomer sheath, provides perfect sealing with respect to sea water, excellent abrasion resistance, and a reliability such that its lifespan may be reckoned at 25 years on average. In addition, the heat insulating device of the present invention withstands the hydrostatic pressures which are exerted at undersea depths greater than 200m and reaching 400m and more; it further provides perfect heat insulation of the fluid which flows in the ducts, since this fluid, whose input temperature may be of the order of 95° C., arrives on the platform at a temperature substantially equal to the input temperature, since the maximum temperature drop observed does not exceed 5° C.
Thus, as is clear from the foregoing, the invention is in no wise limited to those of its modes of implementation, application and embodiments which have just been described more explicitly; it embraces on the contrary all the variants thereof which may occur to a technician skilled in the matter, without departing from the scope or spirit of the present invention. | 4y
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BACKGROUND OF THE INVENTION
The invention concerns a linear connector of plastic material for joining hollow of metal consisting spacing profiles of multiple insulating glasses, comprising a flat, longitudinal body, which is insertable into the hollow space of the one spacing profile and the hollow space of the other spacing profile of the two spacing profiles which are to be connected to one another. The surface of that body is provided with abutment elements in form of elastic braking blades inclined to the surface and abutting during the insertion of the linear connector into the spacing profiles against the profile front faces opposite to one another. Moreover, the body is provided with blade-like springs extending from their small lateral sides which should increase the frictional force between the surface of the body and the inner wall surface of the spacing profiles. The longitudinal body comprises a completely or almost completely U-configured cross-section for the passage of a hygroscopic drying substance powder within this cross-section as well as in the center of its length on both small lateral sides protuberance-like reinforcing elements extending outwardly and in order to reinforce the body radially. These reinforcing elements are opposed by braking blades which will be pressed down by the front faces of the spacing profiles upon the insertion of the body into the hollow space of the spacing profiles. Moreover, these braking blades form an abutment for the spacing profile front faces upon insertion so that the insertion is stopped by them.
Linear connectors of the above mentioned kind are known from German Utility Model Registrations 8,816,799 and 9,216,955. These known linear connectors, however, are provided in mounted condition with certain drawbacks according to which they do not keep the spacing profiles together in an extent requested. Thus, it happens that the gap between the spacing profiles connected to one another opens so that hygroscopic drying substance powder enclosed in the hollow space of the profiles runs through this gap into the space between the two insulating glass panes polluting the same.
The above mentioned drawbacks are also not avoided by linear connectors for joining two parallel hollow spacing profile tracks according to U.S. Pat. No. 5,603,582, although they are provided with two pairs of two distantly separated, parallel legs extending in longitudinal direction of the spacing profile tracks and joined by an abutment rib extending across the longitudinal legs, which abutment rib is provided with front faces being engaged by the front faces of the hollow profile spacing tracks, if the linear connector is in mounted condition. Because this linear connector is not provided on its surface with pressure spring elements, however, the forces keeping the spacing profiles connected at the joining gap are rather weak.
A further linear connector known from German Patent 19,522,505 intended to be used especially for joining spacing profiles of steel comprises doubtlessly the requested strong seat as well as the required stiffness and resistance against abrashion and is also provided with abutments avoiding pushing too far on the insertion of the linear connector body into the hollow space of the spacing profiles. Nevertheless it has certain drawbacks concerning the requested sealing of the space between the glass panes in the area of the joining gap of the spacing profiles. The problems concerning that seal are especially due in case the hygroscopic powder substance as used is characterized by a grain analysis having a particularly high portion of fine grains. These fine grains possibly enter through the mentioned joining gap into the space between the glass panes and thus pollute the panes in an extent not tolerable. Moreover, it has been found out that under the above mentioned conditions the multiple insulating glass cannot fullfill its insulating purpose over long time.
In order to avoid the above mentioned drawbacks blade-like springs are used on the surface of such linear connectors increasing the frictional effect between the linear connector and the spacing profiles in order to keep the joining gap closed. These springs should be constructed such, however, that they keep their tension after mounting in an extent required for maintaining their pressure onto the inner wall surface of the spacing profiles.
The above mentioned requirements, however, are not completely fullfilled by the known linear connectors of the above mentioned kind.
SUMMARY OF THE INVENTION
It is therefore an object of the invention to develop the linear connector of the above mentioned kind further in order to improve the sealing effect between the body of the linear connector at the joining gap and the bodies of the spacing profiles which are to be joined.
In this connection it is a further object of the invention to manufacture the linear connector by using a lesser quantity of plastic material without effecting negatively its function, i.e. especially its stability and its resistance against bending forces.
According to a still further object of the invention it is intended to configure the springs such that their tension after the mounting of the linear connector in the hollow space of the spacing profiles is retained to an extent required in order to keep the joining gap between the spacing profiles as close as possible and in this connection to avoid any decrease of the tension of the springs after mounting and thus any decrease of the friction between the plastic material of the linear connector and the surrounding metal of the spacing profiles.
These and other objects of the invention are solved by a construction characterized in that essentially all blade-like extending springs are configured as double springs, comprising two spring blades arranged behind one another and forming together in general a V-configuration and supporting themselves after the linear connector having been mounted in the spacing profile in a mutual manner, and further characterized in that the protuberance-like reinforcing elements at the bottom of the longitudinal body are configured and arranged such that they form a bar against passing of the hygroscopic drying substance powder outwardly of the U-configured cross-section of the linear connector body.
Because of the supporting effect of that spring blade of each double spring being located in longitudinal direction behind after mounting of the connector body which has a greater angle of inclination to the longitudinal axis of the body as the front spring blade, the latter one develops an additional resistance against deformation without deminishing its spring suspension. This resistance is caused by the fact that the two spring blades are provided at the small lateral sides of the body having a common root and form, respectively. Thus, at the tip of the V an accumulation of material is provided introducing to the front spring blade a repulsion force without changing negatively its flexibility and the spring blade behind is functioning as a support to the front spring blade.
Concerning the protuberance-like reinforcing elements which are known per from the prior art and which are opposed by at least one abutment element in form of elastic brake blades inclined to the center of the body it ist true that during the insertion of the connector body into the hollow space of the spacing profiles these brake blades are pressed downwardly and are thereby plastically deformed. Thus, the reinforcing elements are configured and arranged such that they additionally perform a sealing function in the abutment area of the spacing profile body with respect to the hygroscopic drying substance powder passing through the hollow space of that body.
DESCRIPTION OF THE DRAWINGS
A better understanding of the invention will be reached by reference to the following detailed description when read in conjunction with the accompanying drawings in which
FIG. 1 is a schematical plan view of a first embodiment of the linear connector,
FIG. 2 is a schematical front view of the linear connector of FIG. 1,
FIG. 3 is a schematical bottom view of the linear connector of FIG. 1,
FIG. 4 is a longitudinal sectional lateral view of the linear connector of FIG. 1,
FIG. 5 is a schematical bottom view of a second embodiment of the linear connector,
FIG. 6 is an enlarged detail view of the center area of the bottom of the linear connector according FIG. 3,
FIG. 7 is an enlarged detail view of the center area of the bottom of the linear connector according to FIG. 5,
FIG. 8 is a schematical plan view of a third embodiment of the linear connector,
FIG. 9 is a schematical front view of the linear connector of FIG. 8,
FIG. 10 is a schematical bottom view of the linear connector of FIG. 8,
FIG. 11 is a lateral view of a detail of the double springs located at the small lateral sides of the body of the linear connector, and
FIG. 12 is a detail view of the double springs according to FIG. 11 as a plan view.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Each of the linear connectors as shown in the drawings is comprised of plastic material and is especially suited for joining hollow spacing profiles of steel for multiple insulating glasses. Each linear connector is provided with a flat, longitudinal body, one longitudinal piece 9 of which is insertable into the hollow space of the one spacing profile not shown in the drawings and the other longitudinal piece 10 is insertable into the hollow space of the other spacing profile, also not shown in the drawings, in order to join both spacing profile bodies immovably and tightly.
As shown in FIG. 2 the connector body 1 comprises an U-configured cross-section for the passage or throughput of a hygroscopic drying substance powder and is radially reinforced in the center C of the body on both smaller lateral sides 3 , 4 by protuberance-like reinforcing elements. According to the embodiment as shown in FIGS. 1 and 3 these reinforcing elements are provided with the reference numerals 5 and 6 , respectively, whereas according to the embodiment as shown in FIG. 5 they are provided with the reference numerals 15 and 16 , respectively. Each of these reinforcing elements are opposed by one abutment element in form of an elastic brake blade 7 , 8 or 17 , 18 , respectively, inclined to the center C of the body. These brake blades are according to the embodiment as shown in FIGS. 1 and 3 not joined with the respective reinforcing element 5 , 6 and will be pressed down and plastically deformed by the front face of the spacing profile against the respective reinforcing element 5 , 6 upon the insertion of the linear connector body 1 into the hollow space of the spacing profiles, if this brake blade is located in the direction of insertion in front of the center C of the body, and in case in the direction of insertion the brake blade is located behind the center C of the body it forms an abutment for the spacing profile front face. By the term an abutment against insertion should be understood in this connection that the linear connector cannot be shifted beyond this abutment during insertion. Thus the linear connector cannot be inserted too far into the hollow space of the spacing profiles.
As can be gathered from the embodiment as shown in FIG. 5, the protuberance-like reinforcing elements 15 , 16 are connected to the brake blades 17 , 18 so that these brake blades are not so elastic as they are in the embodiment as shown in FIGS. 1 and 3. Nevertheless, they can be plastically deformed sufficiently during the insertion of the linear connector. On the other hand, the embodiment according to FIG. 5 guarantees that the grains of the hygroscopic powder which possibly enter into the space between the inner wall of the hollow spacing profile and the small lateral sides 3 , 4 of the connector body 1 provided with the blades 2 do not enter from the area of the gap between the joined spacing profiles into the space between the glass panes, because this gap is absolutely sealed by means of the protuberance-like reinforcing elements 15 , 16 . Although such a seal can doubtlessly be gained by the embodiment according to FIGS. 1 and 3, it is required, however, that in this case the brake blades 7 , 8 are tightly engaged by the reinforcing elements 5 , 6 , and such an engagement is only reached during the insertion of the connector body into the hollow space of the spacing profiles, whereas according to the embodiment of the connector body 1 of FIG. 5 such an engangement is present from the first of the beginning.
Configuration and arrangement of the reinforce elements 5 , 6 and 15 , 16 as far as they are in cooperation with the related brake blades 7 , 8 and 17 , 18 , respectively, can be gathered from the enlarged detail view of the center C of the body as shown in FIGS. 6 and 7. According to the embodiment of FIG. 6 one reinforcing element 5 , 6 is configured as a protuberance extending from the small lateral sides 3 and 4 , respectively, so far outwardly that it contacts the inner wall of the hollow spacing profile body which is to be shifted onto the linear connector on mounting. This protuberance is supported in the direction of insertion of the spacing profile, i.e. on its side opposite to the side of the brake blade 7 , 8 , by a wedge 19 , 21 forming with the bottom 20 of the connector body 1 an entirety. The surface of the protuberance is located in the level of the bottom 20 . That lateral surface 22 , 23 of the reinforcing element 5 , 6 located opposite to the front edge of the brake blades 7 , 8 is positioned on the center axis M so that the two reinforcing elements 5 , 6 are offset from one another with respect to this center axis, as can be seen from FIG. 6 .
Concerning the embodiment according to FIG. 7 of the drawing the reinforcing elements 15 , 16 are connected to the opposing brake blades 17 , 18 , so that they are not supported in the direction of insertion by the wedges 19 and 21 as shown in FIG. 6 . The reinforcing elements 15 and 16 are, however, also part of the bottom 20 of the connector body 1 , what means that they pass into the bottom and thus also close the gap of the two space keeping profile bodies to be joined against the space of the glass panes of the multiple insulating glass so that the particles of the hygroscopic powder cannot enter this space.
The above mentioned two embodiments of the linear connector are as shown in the Figures of the drawings and well known in the prior art provided at their parallel small lateral sides 3 , 4 with projections in order to increase the friction between the surface of the linear connector 1 and the inner wall surface of the spacing profiles. These projections are comprised of inclined blades 2 distantly arranged in the longitudinal direction of the body under an angle of 35° to the longitudinal axis B of the body and projecting from the small lateral sides. The angle of adjustment of these blades at the one longitudinal piece 9 differs from that one of the other longitudinal piece 10 insofar as the blades 2 are directed against one another with respect to the center C of the body. These blades are elastic so that they can be elastically deformed if they contact the inner wall of the spacing profile upon insertion of the connector into the hollow space of the profile in order to develop frictional effects. In addition thereto, the brake blades 7 , 8 ; 17 , 18 also develop frictional effects or frictional forces at the inner wall of the spacing profile body ensuring the strong seat of the linear connector within the hollow space. The main function thereof, however, is to form an abutment on the insertion of the linear connector into the hollow space of the spacing profile body in order to stop the insertion from both sides at the center axis M. Therefore, the front faces 11 , 12 , 13 , 14 of the inclined brake blades are positioned in the area of the center axis M at both sides thereof and in a very small distance thereto, as shown in FIGS. 6 and 7.
As can be seen from FIGS. 8 and 9 the body 1 of the linear connector of that embodiment is also provided with an U-cross-section and it is thus suited for the passage of the hygroscopic powder within that cross-section. It comprises as already shown in connection with the linear connector according to the embodiments of FIGS. 1-7, at its two small lateral sides 3 , 4 protuberance-like reinforcing elements 5 and 6 directed outwardly, which are radially reinforcing the body. Each of which is opposed by an abutment element in form of an elastic brake blade 7 , 8 inclined to the center C of the body, which brake blades, however, are not joined with the corresponding reinforcing elements 5 , 6 and are also plastically deformed on the insertion of the body 1 into the hollow space of the spacing profile as shown in connection with the above mentioned described embodiments of the linear connector.
The small lateral sides 3 , 4 of the body 1 are as especially shown in FIGS. 8 and 10 provided with double springs 2 arranged one behind the other and extending blade-like outwardly from the small lateral sides. Each double spring is comprised of two spring blades 2 a , 2 b arranged behind one another and forming together in general a V-configuration and supporting one another, if the body 1 is mounted in the spacing profile. Details of this double spring arrangement and configuration are shown in FIGS. 11 and 12. As can be gathered therefrom the one spring blade 2 a of the double spring 2 which is at the front with respect to the direction of insertion of the linear connector and thus the body 1 provided with a smaller angle of inclination with respect to the longitudinal axis B of the body as the other spring blade 2 b behind. Moreover, the width of the two spring blades measured over the small lateral sides 3 , 4 is different insofar as the width of the spring blade 2 a at front is greater than that one of the spring blade 2 b behind. The height of the spring blades, measured from the surface of the small lateral sides 3 , 4 of the body, is in that embodiment equal. Because of that position and arrangement of the spring blades a supporting effect is raised on inserting the linear connector into the profile bodies to be joined and thus an approved frictional force between the tips of the spring blades and the inner wall of the profile bodies is gained. This supporting effect avoids an early fatigue of the material of the spring blades by bending strengths, because those bending strengths are at least partly balanced by the supporting forces caused by the common basis of the two spring blades forming the double springs 2 .
As can be gathered from FIG. 10, the front spring blade 2 a of each double spring 2 is inclined by an angle of 35° to the longitudinal axis B of the body. The angle of adjustment of that double spring at the one longitudinal piece 9 differs from the angle of adjustment of the other longitudinal piece 10 in such a way, that the double springs 2 are directed against one another with respect to the center C of the body. Not only the double springs 2 , however, are elastically deformable so that they cause a frictional effect if they contact the inner wall of the spacing profile, but also the brake blades 7 , 8 are elastically deformable in a certain extent if they come in contact with the inner wall of the hollow space of the profile upon insertion thereof The main object, however, of these brake blades is to effect as an abutment on the insertion into the spacing profile body in order to stop the insertion procedure on both sides at the center axis M. Therefore, the front faces of the brake blades are inclined by an angle of 45° to the longitudinal axis B of the body adjacent to the center axis M at both sides of that axis and in a relatively small distant from it so that the abutment effect can be realized.
Each protuberance-like reinforcing element 5 , 6 ; 15 , 16 may be an entirety either with a wedge 19 , 21 extending from one of the small lateral sides 3 , 4 of the body 1 , or with one of the brake blades 7 , 8 extending from the small lateral sides. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to clamp assemblies for connecting one member to a support member. In a particularly preferred aspect, the invention relates to an ultra high strength clamp assembly to attach a pipe or line, such as an umbilical line, to another pipe. In a specific embodiment, the invention is particularly adapted for use as a subsea clamp assembly to attach an umbilical line to a choke or kill line of a subsea riser. In the specific embodiment the invention is particularly adapted for use as a variable height stand-off assembly to attach an umbilical line to a choke or kill line in a marine riser assembly.
2. Background of the Invention
The need often arises for a clamp assembly to attach a cable, hose or pipe to a support member or pipe. The situation often occurs where an umbilical line is required to be secured to a support member or pipe at a certain distance away from the support member, for example, to accommodate insulation, floatation and mechanical barriers.
In the offshore drilling and production industry, it is frequently necessary to run umbilical lines hundreds and even thousands of feet below the support vessel or drilling or production platform down to the sea floor and beyond. Typically, the umbilical lines, which may include electric, MUX (fiber optics), and hydraulics, are required to be attached to a support member, such as a choke or kill line, or mud line on a subsea riser system. Due to the high cost of working in such environments, it is critical that the clamp assembly be reliable and dependable to firmly secure the clamped members to prevent costly consequences, such as loss of signal in a fiber optic cable due to slack in an umbilical line which can create a sharp radius in the line preventing signal transmission. Various types of clamp assemblies and stand-off assemblies have been used in these situations. The prior art clamp assemblies and stand-off assemblies have been very costly and time consuming to make, use and install, and many do not clamp the umbilical lines with enough force.
SUMMARY OF THE INVENTION
In one embodiment of the invention, there is provided a base clamp for a tubular member which forms a mounting base for another clamp or an extension leg. The clamp comprises a saddle structure and at least one U-bolt. The saddle structure has a first end, a second end, an upper surface and a lower surface. The lower surface defines a trough extending from the first end to the second end for mounting the saddle structure to a tubular member. The saddle structure further defines at least one pair of parallel apertures positioned one on each side of the trough for receiving a first U-bolt for fastening the saddle structure to the tubular member. A U-bolt having a first end and a second end is received by the apertures and extends over the trough. The upper surface of the saddle structure defines a track configured to receive a shoe.
The track can connect the base clamp via a support leg to a line clamp according to another embodiment of the invention for a tubular hose or cable. The line clamp comprises an upper clamp half, a lower clamp half, a hinge pin connecting the halves, a fastener latching the halves, and a support leg having a shoe. The upper clamp half has a downwardly facing parting line face. The lower clamp half has an upwardly facing parting line face and is positioned in a face to face relationship with the upper clamp half so that the parting line faces are side by side. The hinge pin pivotally connects the clamp halves along a hinge edge. A fastener connects the clamp halves along a latch edge. The support leg extends from the lower clamp half and has an upper end attached to the lower clamp half and a lower end. The shoe is positioned on the lower end of the support leg.
Alternatively, the track can connect the base element to an extension leg according to another embodiment of the invention which can be used to connect the base clamp to the line clamp, or, if desired, to another extension leg. The extension leg has a first end and a second end and a longitudinal axis extending between the first end and the second end. A shoe is positioned on the first end of the extension leg. A track is positioned on the second end of the extension leg which is configured to receive the shoe.
Preferably, the line clamp employs an elastomeric liner according to another embodiment of the invention to reliably position the clamped line. The elastomeric liner is provided in two halves. Each liner half is formed from an elastomeric material and has an outside wall and an inside wall which defines at least one semi-cylindrical trough. The trough has a longitudinal axis, a first end, and a second end and is sized for closely receiving a hose or cable to be clamped. The outside wall is configured to be to be closely received by an inside surface of a clamp half.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an end view, partly in cross section, of a clamp assembly according to one embodiment of the invention.
FIG. 2 is an end view, partly in cross section, of a clamp assembly according to another embodiment of the invention.
FIG. 3 is a partially exploded view of the assembly shown in FIG. 1 .
FIG. 4 is a partially exploded view of the assembly shown in FIG. 2 .
FIG. 5 is a side view of the invention shown in FIG. 1 .
FIGS. 6-18 are pictorial representations of certain components of the devices shown in FIGS. 1 and 2.
FIG. 19 is a cross sectional view of the component shown in FIG. 18 taken along lines 19 — 19 .
FIG. 20 is a bottom view of the device shown in FIG. 18 .
DETAILED DESCRIPTION OF THE INVENTION
with reference to FIGS. 3-7 there is shown a base clamp 30 for a tubular member 32 which forms a mounting base for another clamp or an extension leg. The base clamp comprises a saddle structure 34 and at least one U-bolt 36 . The saddle structure has a first end, a second end, an upper surface and a lower surface. The lower surface defines a trough 38 extending from the first end to the second end for mounting the saddle structure to tubular member 32 . The saddle structure further defines at least one pair of parallel apertures 40 , 41 positioned one on each side of the trough for receiving a first U-bolt for fastening the saddle structure to the tubular member. A U-bolt having a first end and a second end is received by the apertures and extends over the trough See FIGS. 3 and 4. The upper surface of the saddle structure defines a track 42 configured to receive a shoe
The track forms a panel-shaped chamber 44 which is transversely positioned with respect to a radius drawn from a central section of the trough. The track has a track bottom surface 46 facing away from the trough and a roof structure 48 over the track bottom surface which defines a track top surface 50 which faces the track bottom surface and is spaced from the track bottom surface to accommodate the shoe. The roof structure having a slot 52 sized to accept a leg extending from the shoe. The panel shaped chamber and the slot together form an opening transverse to the longitudinal axis of the leg for transverse receipt of a shoe with attached leg. In use, a safety pin 54 (see also FIG. 9) is positioned across the opening to prevent a shoe with attached leg from becoming accidently dislodged. Preferably, the saddle structure defines a first pair and a second pair of parallel apertures. The first pair is positioned one on each side of the trough adjacent the first end of the saddle shaped structure for receiving the first U-bolt for fastening the saddle structure to the tubular member. The second pair is positioned one on each side of the trough adjacent the second end of the saddle shaped structure for receiving a second U-bolt 37 for fastening the saddle structure to the tubular member. See FIG. 5 . The first U-bolt has a first end and a second end which are received by the first pair of apertures. The second U-bolt likewise has a first end, a second end, is received by the second pair of apertures, and extends over the trough. The saddle structure also preferably further defines a port 56 to permit unobstructed passage of a fastener bolt 58 (see FIG. 4) therethrough positioned between an aperture of the first pair and an aperture of the second pair.
The track 42 can connect the base clamp 30 via a support leg to a line clamp according to another embodiment of the invention for a tubular hose or cable. The line clamps illustrated in the Figures are variations of each other and will be described with different reference numerals. The line clamp shown in FIG. 1 will be described with 100 series numerals, while the line clamp shown in FIG. 2 will be described with 200 series numerals.
With reference to FIGS. 1 and 2, the line clamp 102 , 202 comprises an upper clamp half 104 , 204 , a lower clamp half 106 , 206 , a hinge pin 108 , 208 connecting the halves, a fastener 110 , 210 latching the halves, and a support leg 112 , 212 having a shoe 114 , 214 (See FIGS. 10 - 13 ). The upper clamp half has a downwardly facing parting line face. The lower clamp half has an upwardly facing parting line face and is positioned in a face to face relationship with the upper clamp half so that the parting line faces are side by side. The hinge pin pivotally connects the clamp halves along a hinge edge. The fastener connects the clamp halves along a latch edge. The support leg extends from the lower clamp half and has an upper end attached to the lower clamp half and a lower end. The shoe is positioned on the lower end of the support leg.
The clamp halves, when positioned in a face to face relationship, form a clamp assembly which defines at least one passage 116 , 216 therethrough for clamping a cylindrical object, such as line 60 shown in FIG. 5 . The passage has a longitudinal axis and the clamp assembly parts along a parting plane which encompasses the longitudinal axis. The support leg has a longitudinal axis which extends normally to the parting plane. See FIGS. 1 and 2.
In a preferred embodiment, the clamp assembly defines a pair of passages extending therethrough in side-by-side relationship. Even more preferred, an elastomeric liner 120 , 220 lines each of the passages which extend though the clamp assembly 102 , 202 .
Preferably, each elastomeric liner comprises a pair of liner halves 60 (see FIGS. 18-20) positioned in face to face relationship. Each liner half defining at least one trough 62 . One liner half is positioned in each clamp half. Each passage through the clamp assembly is defined by a pair of facing troughs from facing liner halves. In a preferred embodiment, each trough is semicylindrically shaped. A layer 64 of an anti-skid material positioned in each of the semi-cylindrical troughs. Most preferably, the layer of anti-skid material comprises a screen 66 which is coated with abrasive particles.
In order that the liner resist dislodging during handling and use, it is preferably provided with a flange 68 on each end. Each of the flanges preferably has a lip 70 which extends toward the opposite flange and retains the liner half in position on the clamp half.
Where a low profile is not needed, the preferred assembly employs a fastener as shown in FIG. 1 . The fastener comprises a bolt 158 which extends upwardly and has a wing-nut 160 attached. The head of the bolt is attached to a portion of the lower clamp half and the shaft of the bolt extends through a portion of the upper clamp half and protrudes upwardly.
Where a low (or lower) profile is desired, an assembly employing a profile as shown in FIG. 2 can be used. The fastener comprises a bolt 258 having a head which contacts a portion of the upper clamp half and a shaft attached to the head which extends through a portion of the lower clamp half and protrudes downwardly. A port is preferably provided in the base as previously discussed to permit passage of the bolt.
As shown in FIGS. 1, 3 and 10 , a flange 170 can be positioned on the support leg between the upper end and the lower end of the support leg which is of the same shape as the shoe. This permits the length of the leg to be easily modified, in the field if necessary. If a longer leg is necessary, the track on the base clamp can connect the base element to an extension leg 172 . See FIG. 8 . The extension leg has a first end and a second end and a longitudinal axis extending between the first end and the second end. A shoe 174 is positioned on the first end of the extension leg. A track 176 is positioned on the second end of the extension leg which is configured to receive the shoe.
The shoe is panel-shaped and extends transversely to the longitudinal axis of the leg. The track forms a panel-shaped chamber, preferably identical in configuration to the chamber in the saddle structure, which is transversely positioned with respect to the longitudinal axis of the leg. The shoe has an upper shoe surface facing the leg and a lower shoe surface which faces away from the leg. The track has a track bottom surface facing away from the leg and is configured to fully support the lower shoe surface of the shoe. The track has a roof structure over the track bottom surface which defines a track top surface which faces the track bottom surface and is spaced from the track bottom surface so to contact the upper shoe surface and closely position the lower shoe surface of the shoe against the track bottom surface. The roof structure has a slot sized to accept the leg. The panel shaped chamber and the slot together form an opening transverse to the longitudinal axis of the leg for receipt of a shoe and leg. A safety pin, which can be the same as the pin 54 , is preferably positioned across the opening to prevent the shoe and leg from becoming accidently dislodged.
Certain aspects of the liner have been previously discussed. The lips on the liner end flanges combined with its elastomeric construction permit the liner to be snapped onto a clamp half to facilitate handling and reduce the likelihood of accidental dislodging. The anti-skid material can be positioned with a layer of adhesive material positioned between the elastomeric liner half and the layer of anti-skid material, preferably a water-proof adhesive. Suitable anti-skid material is commercially available as sanding screen and can be purchased in rolls. A coarse plastic pipe sanding screen has been used with good results. Such screen is waterproof washable, has an open mesh backing, and is coated with abrasive on both sides. The coated abrasive comprises sharp silicon carbide particles.
The elastomer generally has a durometer of between about 70 and 130, preferably a durometer of between about 85 and about 105. Nitrile rubber having a durometer of about 95 has been used with good results. In the illustrated embodiment, the outside wall of the liner half defines half of a side-by-side tubular surface. The inside wall of the liner half defines flats for abutting corresponding flats on an inside wall of an opposed liner half The illustrated and described clamps have consistently provided a clamping force of over 2500 pounds.
While certain preferred embodiments of the invention have been described herein, the invention is not to be construed as being so limited, except to the extent that such limitations are found in the claims. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to spring assemblies for mattresses, cushions and the like and, more particularly, to new and improved methods and apparatus for forming strings of springs enclosed within pockets having flat overlapping side seams and which do not exhibit the disadvantageous condition encountered in prior art assemblies known as false loft.
2. Description of the Prior Art
Numerous techniques have evolved for constructing mattresses, cushions and the like. One such technique which has gained wide acceptance is known as Marshall construction. In this construction, an innerspring assembly comprises the core of the mattress or cushion and is manufactured from a plurality of springs, each individually encapsulated in a pocket of suitable fabric. The pockets of springs are preferably joined together in a string of predetermined length and are arranged in a closely packed array all with their longitudinal axes parallel one to another and with their ends defining a plane. In mattress construction, this array of pocketed springs is typically covered with a quilted foam and fabric pad thereby providing a sleeping surface.
Strings of pocketed coil springs have been manufactured in different ways. In an early method of manufacture, a suitable fabric was folded in half lengthwise and stitched transversely at regular intervals to define pockets into which springs were inserted. This method has largely been replaced in more recent times by a method which uses heat sensitive fabric and ultrasonic welding techniques instead of stitching. An example of strings of pocketed coil springs manufactured by this latter method is disclosed in U.S. Pat. No. 4,234,983, issued to Stumpf and assigned to the common assignee herein. As disclosed in U.S. Pat. No. 4,234,983, a string of pocketed coils is formed by ultrasonically welding the coils into discrete pockets by first folding a heat sensitive fabric in half lengthwise and applying welds transversely to the longitudinal axis of the fabric. Once the coil springs are inserted into the pockets, the pockets are welded closed along a seam running lengthwise of the coil string adjacent one end of the springs. Apparatus for manufacturing the foregoing strings of coils is disclosed, for example, in U.S. Pat. No. 4,439,977, also issued to Stumpf and assigned to the common assignee herein.
A disadvantage of strings of coil springs of the foregoing construction is that the seam running lengthwise of the coil string creates two flaps of excess fabric material at one end of the pocketed springs. Some excess material is necessary along the seam to provide for proper alignment of the string in manufacture and assure adequate strength of the associated welds. However, when the string of coils is arranged to define an innerspring mattress or cushion core, the excess material projecting outwardly of the springs creates a false firmness which is known in the art as "false loft" beneath the outer surface pad of the mattress or cushion. This false loft condition can cause undesirable and objectionable body depressions to form when a user lays on a mattress or cushion.
Attempts have been made to eliminate false loft by constructing a string of coil springs having a flat overlap side seam instead of a top seam. A machine for constructing such coil strings is disclosed, for example, in U.S. Pat. No. 4,986,518, also issued to Stumpf and assigned to the common assignee herein. However, such a machine has a complicated elevator mechanism for spring insertion which has proven to be unreliable under manufacturing conditions.
Accordingly, it has been found to be desirable to provide mattress or cushion constructions in which the innerspring assembly is enclosed within pockets having flat overlap side seams. In particular, it has been found to be desirable to provide such mattress or cushion constructions which do not exhibit false loft by virtue of excess pocketing material adjacent the ends of the coils. Furthermore, it has been found to be desirable to provide coil string assemblies for innerspring constructions which use less pocketing fabric material than has been required in previously known constructions.
Still further, it has been found to be desirable to provide apparatus for constructing pocketed coil strings which are housed within pockets having flat overlap side seams. Such apparatus has been found to be effective, efficient and reliable in use and is structured to be readily retrofitted with existing prior art equipment at an economical cost.
SUMMARY OF THE INVENTION
The present invention improves over the prior art by providing a new method and apparatus for constructing strings of fabric pocketed coils with the pockets having flat overlap side seams. The apparatus includes a fabric in-feed station wherein a fabric web is twice folded to define a tube having a first flap which overlaps a second flap on one side of the tube. In the apparatus, this tube is advanced to a next station at which a deflector separates the overlapped flaps. A coil inserter is then disposed between the separated flaps and a vertically compressed coil spring is inserted horizontally into an open side of the tube. The fabric tube with the compressed coil therein is next advanced to a second deflector which realigns the flaps in overlapping relation. At a next station an anvil supports the overlapping flaps whereupon the flaps are spot welded together. At the next station, transverse seams are welded between the coil springs creating a discrete, individual pocket for each coil. At a final station, a beater assembly strikes the pocketed compressed coils to rotate them in their pockets and allow them to expand longitudinally.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other novel features of the invention will become apparent upon a reading of the following detailed description taken in conjunction with the accompanying drawings wherein:
FIG. 1 is a perspective view of a prior art mattress partially broken away to show a conventional innerspring construction;
FIG. 2 is a fragmentary side view of the prior art innerspring shown in FIG. 1;
FIG. 3 is a partial perspective view of a fabric in-feed station of an apparatus in accordance with the present invention;
FIG. 4 is another partial perspective view of the in-feed station of FIG. 3 showing fabric being folded therein;
FIG. 5 is a schematic end view of a fabric tube constructed in accordance with the present invention;
FIG. 6 is a schematic end view of a first deflector station of an apparatus in accordance with the present invention illustrating a stage in the inventive process wherein the flaps on a fabric tube are separated to expedite subsequent insertion of coil springs therein;
FIG. 7 is a schematic view of a spring insertion station in accordance with the present invention illustrating a stage in the inventive process wherein a spring, in an uncompressed state, is positioned prior to insertion into a fabric tube;
FIG. 8 is a schematic view of the spring insertion station of FIG. 7 showing the spring in a fully compressed state for insertion into a fabric flap;
FIG. 9 is a further schematic view of the spring insertion station of FIG. 7 with the apparatus aligned for insertion of the fully compressed spring into the fabric tube;
FIG. 10 is a schematic view of the spring insertion station of FIG. 7 showing the spring inserted into the fabric tube;
FIG. 11 is a schematic view of a second deflector station of an apparatus in accordance with the present invention illustrating a stage in the inventive process wherein the flaps on the fabric tube are returned to their original overlapped condition after spring insertion;
FIG. 12 is a schematic view illustrating apparatus for performing the next processing stage in accordance with the present invention wherein the flaps on the fabric tube are positioned for processing after insertion of a spring therein;
FIG. 13 is a schematic view of a first welding station of an apparatus in accordance with the present invention illustrating a stage in the inventive process wherein the flaps on the fabric tube are lap sealed;
FIG. 14 is a schematic view of a second welding station of an apparatus in accordance with the present invention illustrating a stage in the inventive process wherein discrete fabric pockets with coil springs encapsulated therein;
FIG. 15 is a schematic view of a drive station of an apparatus in accordance with the present invention illustrating a mechanism for drawing the fabric tube through the apparatus for processing;
FIG. 16 is a schematic view of a final forming sattion of an apparatus in accordance with the present invention illustrating a mechanism for properly orienting the spring within a fabric pocket; and
FIG. 17 is a fragmentary side view of a string of pocketed coils constructed in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, and initially to FIG. 1, a mattress assembly of a type well-known in the art is designated generally by reference numeral 10 and includes an innerspring core assembly 12 of the so-called Marshall construction. The core 12 includes a string 14 of coils 16 within fabric pockets 18 arranged in a closely packed array having a generally rectangular shape in plan. For purposes of the present disclosure, the term coils may be used interchangeably with springs or coil springs. The coils 16 are all oriented with their longitudinal axes parallel to each other and with their ends all lying in a common plane. A suitable cover 19 is provided for the innerspring core 12 and is typically made of a quilted foam and/or fabric material defining a sleeping surface.
Referring now to FIG. 2, a portion of the prior art string 14 of coils 16 enclosed within fabric pockets 18 is illustrated in side view and comprises a web of fabric 20 which is essentially folded in half lengthwise. The fabric is preferably heat sensitive and is formed into a series of spaced pockets by transverse welds 22. The welds 22 define webs 24 connecting the pockets to form a string 14 which can be of any preselected length. Because the fabric 20 is folded in half, a seam 26 is welded across the upper edge of the string 14, as viewed in FIG. 2, in order to close the pocket. This forms a pair of flaps 28, only one of which can be seen, running lengthwise of the string 14 above the plane defined by the upper ends of the coils 16. The flaps 28 are necessary to space the welds of the seam 26 inwardly of the edges of the fabric 20 and thereby assure adequate strength of the seam 26, as well as to provide for proper alignment of the string 14 in manufacture.
Turning now to FIGS. 3 and 4, a portion of an apparatus for constructing strings of pocketed coil springs 16 in accordance with the invention is designated generally by the reference numeral 30. As described hereinafter, the apparatus will be discussed in terms of its progressive sequences of operation, in the so-called apparatus direction, beginning with the portion 30 which is a pocket material in-feed station.
At the in-feed station 30, a web of heat sensitive fabric 32 is fed into the apparatus across a diamond-shaped folding plate 34. Preferably, the fabric 32 is of a non-woven polypropylene composition, for example, of a type sold under the trade name DUON. A guide bar 35 extends over the top of the fabric 32 in spaced relation to the folding plate 34 to assure that the fabric 32 will lay flat on the plate 34. Adjustable guide bars 36 are positioned along opposite edges of the fabric web 32 to properly align the fabric 32 for folding. The fabric 32 travels over edges 38 of the folding plate 34 which converge to a point 40. Beneath the plate 34 and extending from a frame member 42 are a pair of closely spaced parallel guide bars 44. The guide bars 44 are aligned with the point 40 of the folding plate and have a mounting structure which includes spring tensioning means (not shown) to urge them into closely spaced relation. The fabric 32 passes between the guide bars 44 and a first fold 46 in the fabric 32 is created defining a first flap which will be consistently designated hereinafter as flap A.
The web of fabric 32 next passes around an idler roller 48 which extends from and is journalled for rotation on the frame 42. As best seen in FIG. 4, the fabric 32 then passes around a second roller 50. This roller 50 is journalled on a frame member (not shown) which is disposed opposite to and spaced from frame 42. The roller 50 extends only a portion of the width of the folded fabric 32 creating a loose edge 52 of fabric 32 which passes around free end 54 of the second roller 50. A smoothly rounded hook member 56 extends from the frame 42 in proximity with the end 54 of the roller 50 and engages the loose edge 52 of fabric 32 causing the edge 52 to reversely turn over the web 32 and form a second fold 58. The second fold 58 creates a second flap which will be designated consistently hereinafter as flap B. The web 32 which has now been twice folded then passes over a third roller 60 which is journalled for rotation on the frame 42 and the web 32 exits the fabric in-feed station 30 in an essentially horizontal orientation.
The configuration of the fabric 32 after it leaves the in-feed station 30 is shown schematically in FIG. 5. The fabric 32 is formed into a fabric tube 33, preferably having an essentially flat tubular shape with flap A folded over a back portion 62 at first fold 46 and flap B folded over back portion 62 at second fold 58. In a preferred form, flap A is approximately six inches in width while flap B is approximately three inches in width. Also, flap B preferably overlaps flap A by approximately one-half inch. It can be appreciated that the width of flap A can be predetermined by the adjustable lateral alignment of the fabric Web 32 with respect to the point 40 of the folding plate 34. Moreover, the width of flap B can be predetermined by the suitable positioning of the second roller 50 and associated hook member 56.
The fabric tube 33 advances next to a first deflector station shown schematically in FIG. 6 and designated generally by the reference numeral 64. A deflector arm 66 has a free end portion 68 which is configured for insertion beneath flap B and separates flap B from its overlapped relation with flap A. It will be understood by those skilled in the art that while not shown in FIG. 6 or subsequent figures, the apparatus of the present invention includes a suitable elongated table or plate for supporting the back side 62 of the fabric tube 33 throughout successive steps in the assembly process.
Next, the fabric tube 33 advances to a coil insertion station shown in FIG. 7 and designated generally by the reference numeral 70. A coil inserter assembly is designated as 72 and includes an upper plate 74 and a lower plate 76 arranged parallel to one another and spaced from one another by approximately three-eighths of an inch. Upper plate 74 has a circular opening 78 which is dimensioned to permit a coil spring 16 to pass through it and be supported on the lower plate 76 with the longitudinal axis of the spring 16 oriented vertically. It is to be noted that the spring 16 is transported to the inserter 72 in a fully extended state by any suitable transport means (not shown) and is positioned under a compressor 80 which is in vertical alignment with the opening 78 in the upper plate 74. The condition of the fabric tube 33 at this point is such that flap B is positioned to pass underneath the lower plate 76 of the inserter 72 while flap A passes under a support plate 82 and has edge portion 84 supported on the upper plate 74 of the inserter 72. The edge portion 84 of flap A is pressed firmly to the plate 74 by a tensioned roller 86.
In FIG. 8, the spring 16 is shown in a compressed state upon activation of the compressor 80. FIG. 9 shows the next step of the coil insertion process wherein the fabric tube 33 is advanced in a manner such that edge portion 84 of flap A moves into registry with an air cylinder 88. Coil insertion is completed in the schematic view of FIG. 10 which shows ram 90 of the air cylinder 88 activated to hold the edge portion 84 of flap A firmly to the upper inserter plate 74 while a reciprocating air operated inserter bar 92 moves the compressed coil 16 horizontally from the compressor 80 to a position beneath flap A.
Once coil insertion is completed, the fabric tube 33 advances with the compressed coil 16 under support plate 82 to a second deflector station designated generally as 94 in FIG. 11. At this station 94, a second deflector arm 96 has a free end portion 98 which engages and lifts flap B to its original overlapped condition with respect to flap A.
FIG. 12 illustrates apparatus 100 for performing the next step in the process of this invention wherein the fabric tube 33 is received by an anvil 102. The anvil 102 may be supported by plate 82 and includes a first upper arm 104 over which flap B passes. Flap B is pressed firmly into contact with arm 104 by a second tensioned roller 106. In this step of the process, flap A passes under the first anvil arm 104 and over the top of a second lower arm 108 which is suspended in a cantilevered manner from first arm 104. The anvil 102 is designed so that lower arm 108 also projects horizontally in the apparatus direction from beneath upper arm 104.
Turning now to FIG. 13, a first welding station is designated generally by the reference numeral 110 and includes an ultrasonic spot welding horn 112. At this station 110, the fabric tube 33 has passed the upper arm 104 of the anvil 102 whereupon flap B returns to overlapped engagement with flap A, the two flaps being supported by lower arm 108 of the anvil 102. The welding horn 112 is next activated to place a spot weld on the lap between flap A and flap B, whereby a lap seal is formed.
In FIG. 14, a second welding station is designated by the reference numeral 114 and includes a second welding horn 116 which is oriented transversely to the fabric tube 33. In a manner well-known in the art, this second welding horn 116 is designed to form a linear series of spaced welds between the upper and lower sides of the fabric tube 33 intermediate successive coils 16 thereby forming a string 14 of discrete fabric pockets 18 with individual spring coils 16 encapsulated within each pocket.
FIG. 15 illustrates schematically a drive station 120 of the apparatus which comprises a pair of parallel closely spaced rollers 122 and 124. The rollers 122 and 124 are so tensioned together that they serve to draw the fabric tube 33 through the apparatus from the in-feed station 30 through all subsequent processing stations of the apparatus. A suitable recess 126 is formed in one of the rollers 122 or 124 so that the coil springs 16 can pass freely between the rollers 122 and 124.
A final forming station is shown schematically in FIG. 16 and designated generally by the reference numeral 130. At this station 130 a rotating beater assembly 132 is provided with resilient arms 134 for striking the fabric tube 33 in the area of the pocketed coil springs 16. This striking action of the beater 132 causes the coil springs 16 to rotate ninety degrees within their pockets and to expand from their compressed state to an extended state, thereby filling the pocket 18.
It can now be appreciated that the apparatus of the present invention is highly efficient and effective for constructing strings of pocketed coil springs which have the a seal formed along a side thereof instead of having a seal adjacent to the ends of the springs. A string of fabric pocketed coils 136 constructed with the present apparatus is illustrated in side view in FIG. 17. As seen therein, a flat overlap side seam 138 eliminates the two upper flaps 28 of the prior art string 14 shown in FIG. 2. Thus, the coil string 136 is highly desirable for use in a mattress innerspring assembly in that it eliminates objectionable false loft. It can also be appreciated that because the side seam 138 may overlap by only about one-half inch or so, savings in fabric 32 can be achieved over the prior art constructions which have two excess flaps 28. Further, the apparatus of the present invention may be readily configured from existing known equipment with the addition and/or replacement of a few parts and subassemblies. Accordingly, the invention lends itself to highly economical retrofitting of equipment currently in use.
While the present invention has been described in connection with a preferred embodiment thereof, it will be understood by those skilled in the art that many changes and modifications may be made without departing from the true spirit and scope of the invention. Accordingly, it is intended by the appended claims to cover all such changes and modifications which come within the true spirit and scope of the invention. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of U.S. application Ser. No. 11/906,325, filed on Oct. 1, 2007, which is a continuation-in-part of U.S. application Ser. No. 11/359,667, filed on Feb. 22, 2006, which is a continuation-in-part of U.S. application Ser. No. 10/662,043, filed on Sep. 12, 2003, which is a continuation of U.S. application Ser. No. 10/428,708 filed on May 2, 2003, the complete disclosures of which are hererin incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to analyzing blood for carrying out coagulation studies and other chemistry procedures, including monitoring oral anticoagulant therapy to take into account the platelet count in determining prothrombin times (PT), and providing new Anticoagulant Therapy Factors that are useful in diagnosing and treating individuals in relation to blood conditions.
[0004] 2. Description of the Prior Art
[0005] Testing of blood and other body fluids is commonly done in hospitals, labs, clinics and other medical facilities. For example, to prevent excessive bleeding or deleterious blood clots, a patient may receive oral anticoagulant therapy before, during and after surgery. Oral anticoagulant therapy generally involves the use of oral anticoagulants—a class of drugs which inhibit blood clotting. To assure that the oral anticoagulant therapy is properly administered, strict monitoring is accomplished and is more fully described in various medical technical literature, such as the articles entitled “PTs, PR, ISIs and INRs: A Primer on Prothrombin Time Reporting Parts I and II” respectively published November, 1993 and December, 1993 issues of Clinical Hemostasis Review , and herein incorporated by reference.
[0006] These technical articles disclose anticoagulant therapy monitoring that takes into account three parameters which are: International Normalized Ratio (INR), International Sensitivity Index (ISI) and prothrombin time (PT), reported in seconds. The prothrombin time (PT) indicates the level of prothrombin and blood factors V, VII, and X in a plasma sample and is a measure of the coagulation response of a patient. Also affecting this response may be plasma coagulation inhibitors, such as, for example, protein C and protein S. Some individuals have deficiencies of protein C and protein S. The INR and ISI parameters are needed so as to take into account various differences in instrumentation, methodologies and in thromboplastins' (Tps) sensitivities used in anticoagulant therapy. In general, thromboplastins (Tps) used in North America are derived from rabbit brain, those previously used in Great Britain from human brain, and those used in Europe from either rabbit brain or bovine brain. The INR and ISI parameters take into account all of these various factors, such as the differences in thromboplastins (Tps), to provide a standardized system for monitoring oral anticoagulant therapy to reduce serious problems related to prior, during and after surgery, such as excessive bleeding or the formation of blood clots.
[0007] The ISI itself according to the WHO 1999 guidelines, Publication no. 889-1999, have coefficients of variation ranging from 1.7% to 8.1%. Therefore, if the ISI is used exponentially to determine the INR of a patient, then the coefficients of variation for the INR's must be even greater than those for the ISI range.
[0008] As reported in Part I (Calibration of Thromboplastin Reagents and Principles of Prothrombin Time Report) of the above technical article of the Clinical Hemostasis Review , the determination of the INR and ISI parameters are quite involved, and as reported in Part II (Limitation of INR Reporting) of the above technical article of the Clinical Hemostasis Review , the error yielded by the INR and ISI parameters is quite high, such as about up to 10%. The complexity of the interrelationship between the International Normalized Ratio (INR), the International Sensitivity Index (ISI) and the patient's prothrombin time (PT) may be given by the below expression (A),
[0000] wherein the quantity
[0000]
[
Patient
'
s
PT
Mean
of
PT
Normal
Range
]
(
A
)
[0000] is commonly referred to as prothrombin ratio (PR):
[0000]
INR
=
[
Patients
'
s
PT
Mean
of
PT
Normal
Range
]
ISI
(
B
)
[0009] The possible error involved with the use of International Normalized Ratio (INR) is also discussed in the technical article entitled “Reliability and Clinical Impact of the Normalization of the Prothrombin Times in Oral Anticoagulant Control” of E. A. Loeliger et al., published in Thrombosis and Hemostasis 1985; 53: 148-154, and herein incorporated by reference. As can be seen in the above expression (B), ISI is an exponent of INR which leads to the possible error involved in the use of INR to be about 10% or possibly even more. A procedure related to the calibration of the ISI is described in a technical article entitled “Failure of the International Normalized Ratio to Generate Consistent Results within a Local Medical Community” of V. L. Ng et al., published in Am. J. Clin. Pathol. 1993; 99: 689-694, and herein incorporated by reference.
[0010] The unwanted INR deviations are further discussed in the technical article entitled “Minimum Lyophilized Plasma Requirement for ISI Calibration” of L. Poller et al. published in Am. J. Clin. Pathol . February 1998, Vol. 109, No. 2, 196-204, and herein incorporated by reference. As discussed in this article, the INR deviations became prominent when the number of abnormal samples being tested therein was reduced to fewer than 20 which leads to keeping the population of the samples to at least 20. The paper of L. Poller et al. also discusses the usage of 20 high lyophilized INR plasmas and 7 normal lyophilized plasmas to calibrate the INR. Further, in this article, a deviation of +/−10% from means was discussed as being an acceptable limit of INR deviation. Further still, this article discusses the evaluation techniques of taking into account the prothrombin ratio (PR) and the mean normal prothrombin time (MNPT), i.e., the geometric mean of normal plasma samples.
[0011] The discrepancies related to the use of the INR are further studied and described in the technical article of V. L. NG et al. entitled, “Highly Sensitive Thromboplastins Do Not Improve INR Precision,” published in Am. J. Clin. Pathol., 1998; 109, No. 3, 338-346 and herein incorporated by reference. In this article, the clinical significance of INR discordance is examined with the results being tabulated in Table 4 therein and which are analyzed to conclude that the level of discordance for paired values of individual specimens tested with different thromboplastins disadvantageously range from 17% to 29%.
[0012] U.S. Pat. No. 5,981,285 issued on Nov. 9, 1999 to Wallace E. Carroll et al., which discloses a “Method and Apparatus for Determining Anticoagulant Therapy Factors” provides an accurate method for taking into account varying prothrombin times (PT) caused by different sensitivities of various thromboplastin formed from rabbit brain, bovine brain or other sources used for anticoagulant therapy. This method does not suffer from the relatively high (10%) error sometimes occurring because of the use of the INR and ISI parameters with the exponents used in their determination.
[0013] The lack of existing methods to provide reliable results for physicians to utilize in treatment of patients has been discussed, including in a paper by Davis, Kent D., Danielson, Constance F. M., May, Lawrence S., and Han, Zi-Qin, “Use of Different Thromboplastin Reagents Causes Greater Variability in International Normalized Ratio Results Than Prolonged Room Temperature Storage of Specimens,” Archives of Pathol. and Lab. Medicine , November 1998. The authors observed that a change in the thromboplastin reagent can result in statistically and clinically significant differences in the INR.
[0000] Considering the current methods for determining anticoagulant therapy factors, there are numerous opportunities for error. For example, it has been reported that patient deaths have occurred at St. Agnes Hospital in Philadelphia, Pa. There the problem did not appear to be the thromboplastin reagent, but rather, was apparently due to a failure to enter the correct ISI in the instrument used to carry out the prothrombin times when the reagent was changed. This resulted in the incorrect INR's being reported. Doses of coumadin were given to already overanticoagulated patients based on the faulty INR error, and it is apparent that patient deaths were caused by excessive bleeding due to coumadin overdoses. In the St. Agnes Hospital, Philadelphia 2001 INR disaster, an incorrect ISI of 1.01 was used instead of 2.028. As has been recommended by Poller, INR studies should be performed at the INR 2.0 and 3.0 levels. 2.0 to 3.0 is the Therapeutic INR Range recommended for most clotting/thrombotic conditions. These two levels will be used in the following calculations:
[0014] The PRs at INR 2.0 calculation are:
[0000] INR=PR ISI ; log INR=(ISI)(log PR);
[0000] log PR=log INR/ISI;
[0000] log PR=log 2.0=0.301; log PR/ISI=0.301/1.01=0.298
[0000] PR=1.986
[0000] INR=PR ISI =1.986 1.01 =2.00
[0000] INR=PR ISI =1.986 2.028 =4.02
[0000] An INR of 2.00 would have been reported, not the actual 4.02. Warfarin at a reported INR 2.0 level would likely have been administered to an already overanticoagulated patient, but serious consequences may not necessarily have occurred here. Using the erroneous 1.01 ISI with an INR of 3.0 for calculations is drastically different:
[0000] log PR=log INR/ISI=0.477/1.01=0.472
[0000] PR=2.968
[0000] INR=PR ISI =2.968 1.01 =3.00
[0000] INR ISI =2.968 2.028 =9.08
[0015] This incorrectly reported INR of 3.0 would actually have been 9.08. 9.08 is well above INR=6.0 where excessive bleeding is considered to occur. In addition, the five fatal St. Agnes cases, even at INR=9.08, could have even been administered a routine warfarin dose, since it would have been believed it was intended for patients with an INR of 3.0, not 9.08.
[0016] But even in addition to errors where a value is not input correctly, the known methods for determining anticoagulant therapy factors still may be prone to errors, even when the procedure is carried out in accordance with the reagent manufacturer's ISI data. One can see this in that current methods have reported that reagents used to calculate prothrombin times, may, for healthy (i.e., presumed normal) subjects, give rise to results ranging from 9.7 to 12.3 seconds at the 95th % reference interval for a particular reagent, and 10.6 to 12.4 for another. The wide ranges for normal patients illustrates the mean normal prothrombin time differences. When the manufacturer reference data ranges are considered, if indeed 20 presumed normal patients' data may be reported within a broad range, then there is the potential for introduction of this range into the current anticoagulation therapy factor determinations, since they rely on the data for 20 presumed normal patients. Considering the reagent manufacturer expected ranges for expected normal prothrombin times, INR units may vary up to 30%. This error is apparently what physicians must work with when treating patients. A way to remove the potential for this type of error is needed.
[0017] This invention relates to the inventions disclosed in U.S. Pat. Nos. 3,905,769 ('769) of Sep. 16, 1975; 5,197,017 ('017) dated Mar. 23, 1993; and 5,502,651 ('651) dated Mar. 26, 1996, all issued to Wallace E. Carroll and R. David Jackson, and all of which are incorporated herein by reference. The present invention provides apparatus and methods for monitoring anticoagulant therapy.
SUMMARY OF THE INVENTION
[0018] Methods and apparatus useful for processing coagulation studies, and other chemistry procedures involving blood and blood components. The apparatus and methods may be used to determine anticoagulant therapy factors which are designated herein, in particular, to determine new Anticoagulant Therapy Factors (nATF's) which preferably may replace International Normalized Ratio (INR) in anticoagulation therapy management. Previously, anticoagulation therapy involved the use of International Normalized Ratios (INR's). The International Normalized Ratio (INR) was utilized in order to arrive at an anticoagulant therapy factor (ATF). The INR based ATF was dependent on the prothrombin time (PT), the prothrombin ratio (PR), a fibrinogen transformation rate (FTR), and a maximum acceleration point (MAP) having an associated time to maximum acceleration (TMA).
[0019] Methods and apparatus are disclosed for determining a new anticoagulant therapy factor (nATF) for monitoring oral anticoagulant therapy to help prevent excessive bleeding or deleterious blood clots that might otherwise occur before, during or after surgery. In one embodiment, a new anticoagulant therapy factor (nATF) is based upon a determination of the fibrinogen transformation rate (FTR) which, in turn, is dependent on a maximum acceleration point (MAP) for fibrinogen (FBG) conversion. The nATF quantity is also based upon the time to maximum acceleration from the time of reagent injection (TX) into a plasma sample, but does not require the difficulty of obtaining prior art International Normalized Ratio (INR) and International Sensitivity Index (ISI) parameters. The International Normalized Ratio (INR) was created to relate all species' clotting material to human clotting material, and nATF can replace INR in anticoagulant therapy management.
[0020] In accordance with other embodiments, methods and apparatus are provided for determining an anticoagulation therapy factor, which do not require the use of a mean normal prothrombin time (MNPT) and ISI data. In other words, the need to obtain and calculate the prothrombin time of 20 presumed normal patients, is not required to determine an anticoagulant therapy factor.
[0021] In accordance with the present invention, there is provided apparatus and methods for carrying out coagulation studies and other chemical procedures and analyses.
[0022] Another embodiment provides methods and apparatus for determining an anticoagulant therapy factor or INR, such as INRn, from the derivation of clotting curve values in connection with a designated area defined by clotting curve data. One preferred embodiment relates to an area defined by clotting curve data that corresponds with the area of a trapezoid formed along the clotting curve.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a diagram of potentiophotometric apparatus constructed in accordance with one embodiment of the present invention for determining blood chemistry analyses such as coagulation studies, including determination of the new anticoagulant therapy factor (nATF), where the output of the analog/digital (A/D) converter is applied to a computer.
[0024] FIG. 2 is a plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process.
[0025] FIG. 3 is another plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process.
[0026] FIG. 4 is another plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process.
[0027] FIG. 5 is another plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process illustrating the fibrinogen lag phase.
[0028] FIG. 6 is another plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process involves a trapezoidal configuration formed by points along the clotting curve.
[0029] FIG. 7 is an illustration showing a preferred embodiment of a trapezoidal representation formed based on data from the clotting curve reaction, as shown in FIG. 6 .
[0030] FIGS. 8 , 9 , 10 and 11 are Bland-Altman plots representing data from Table 16.
DETAILED DESCRIPTION
[0031] Referring to the drawings, wherein the same reference numbers indicate the same elements throughout, there is shown in FIG. 1 a light source 4 which may be a low power gas laser, or other light producing device, producing a beam of light 6 which passes through a sample test tube, such as the container 8 , and is received by detection means which is preferably a silicon or selenium generating photocell 10 (photovoltaic cell). Battery 12 acts as a constant voltage DC source. Its negative terminal is connected through switch 14 to one end of variable resistor 16 and its positive terminal is connected directly to the opposite end of variable resistor 16 . The combination of battery 12 and variable resistor 16 provides a variable DC voltage source, the variable voltage being derivable between line 18 at the upper terminal of resistor 16 and wiper 20 . This variable DC voltage source is connected in series with detection means photocell 10 , the positive output of detection means photocell 10 being connected to the wiper 20 of variable resistor 16 so that the voltage produced by the variable voltage DC source opposes the voltage produced by the detection means photocell 10 . The negative output of detection means photocell 10 is connected through variable resistor 22 to line 18 . Thus, the voltage across variable resistor 22 is the difference between the voltage produced by the variable voltage DC source and the voltage produced by the photovoltaic cell 10 . The output of the electrical network is taken between line 18 and wiper 24 of variable resistor 22 . Thus, variable resistor 22 acts as a multiplier, multiplying the voltage produced as a result of the aforesaid subtraction by a selective variable depending on the setting of variable resistor 22 . The potentiophotometer just described embodies the electrical-analog solution to Beer's Law and its output is expressed directly in the concentration of the substance being measured.
[0032] Wiper 24 is illustrated placed at a position to give a suitable output and is not varied during the running of the test. The output between line 18 and wiper 24 is delivered to an A/D converter 26 and digital recorder 28 . As is known, the A/D converter 26 and the digital recorder 28 may be combined into one piece of equipment and may, for example, be a device sold commercially by National Instrument of Austin, Tex. as their type Lab-PC+. The signal across variable resistor 22 is an analog signal and hence the portion of the signal between leads 18 and wiper 24 , which is applied to the A/D converter 26 and digital recorder 28 , is also analog. A computer 30 is connected to the output of the A/D converter 26 , is preferably IBM compatible, and is programmed in a manner described hereinafter.
[0033] For example, preferably, the detector cell 10 is positioned adjacent an opposite wall of the sample container 8 , and the emitter light source 4 positioned adjacent on opposite wall, so the light 6 emitted from the light source 4 passes through the container 8 . The light source 4 is preferably selected to produce light 6 which can be absorbed by one or more components which are to be measured.
[0034] The apparatus can be used to carry out coagulation studies in accordance with the invention. In accordance with a preferred embodiment of the present invention, the light source 4 may, for example, comprise a light emitting diode (LED) emitting a predetermined wavelength, such as for example, a wavelength of 660 nm, and the detector cell 10 may, for example, comprise a silicon photovoltaic cell detector. Optionally, though not shown, a bar code reader may also be provided to read bar code labels placed on the sample container 8 . The bar code reader may produce a signal which can be read by the computer 30 to associate a set of data with a particular sample container 8 .
[0035] To carry out a coagulation study on blood plasma, the citrated blood is separated from the red blood cell component of the blood. Conventional methods of separation, which include centrifugation, may be employed. Also, the use of a container device such as that disclosed in our issued U.S. Pat. No. 6,706,536, may also be used, and the method disclosed therein for reading the plasma volume relative to the sample volume may also be employed.
[0036] Illustrative of an apparatus and method according to one embodiment is a coagulation study which can be carried out therewith. A reagent, such as, for example, Thromboplastin-Calcium (Tp-Ca), is added to the plasma sample which is maintained at about 37° C. by any suitable temperature control device, such as a heated sleeve or compartment (not shown). The reagent addition is done by dispensing an appropriate amount of the reagent into the plasma portion of the blood. The plasma portion may be obtained by any suitable separation technique, such as for example, centrifugation. In one embodiment illustrated herein, the container 8 is vented when reagent is added. The reagent for example, may comprise thromboplastin, which is added in an amount equal to twice the volume of the plasma. The reagent is mixed with the plasma. It is preferable to minimize air bubbles so as not to interfere with the results. The plasma sample to which the reagent has been added is heated to maintain a 37° C. temperature, which, for example, may be done by placing the container holding the plasma and reagent in a heating chamber (not shown).
[0037] Readings are taken of the optical activity of the components in the sample container 8 .
[0038] Reaction kinematics may be studied by observing changes in the optical density of the plasma layer. For example, an amount of reagent, such as Thromboplastin-Calcium (Tp-Ca), may be added to the plasma sample in the container. The plasma sample in the container may comprise a known amount of volume. Alternately, the plasma volume may be ascertained through the method and apparatus described in our U.S. Pat. No. 6,706,536. A controlled amount of Tp-Ca reagent is added to the plasma sample. The amount of reagent added corresponds to the amount of plasma volume. The detector cell 10 and emitter light source 4 are preferably positioned so the absorbance of the plasma sample may be read, including when the reagent is added and the sample volume is thereby increased.
[0039] With the detection elements, such as the cell 10 and emitter 4 , positioned to read the plasma sample and the reagents added thereto, the reaction analysis of the extended prothrombin time curve can be followed. FIG. 2 shows a graph of a plot of the various phases of the fibrinogen concentration occurring in a typical plasma clotting process. The change in optical density of the plasma level occurs after reagents have been added. The optical density of the plasma sample is monitored, as optically clear fibrinogen converts to turbid fibrin.
[0040] The coagulation study of the type described above is used to ascertain the results shown in the graph plotted on FIG. 2 . The description of the analysis makes reference to terms, and symbols thereof, having a general description as used herein, all to be further described and all of which are given in Table 1.
[0000]
TABLE 1
SYMBOL
TERM
GENERAL DESCRIPTION
PT
Prothrombin Time
A period of time calculated from the addition of the
reagent (e.g., thromboplastin-calcium) to a point where
the conversion of fibrinogen to fibrin begins (i.e. the
formation of the first clot).
TMA
Time to Maximum
The time from PT to a point where the rate of conversion
Acceleration
of fibrinogen to fibrin has reached maximum and begins
to slow.
MAP
Maximum Acceleration Point
A point where the fibrinogen conversion achieves
maximum acceleration and begins to decelerate.
EOT
End of Test
Point where there is no appreciable change in the
polymerization of fibrin.
TEOT
Theoretical End Of Test
The time to convert all fibrinogen based on the time to
convert the fibrinogen during the simulated Zero Order
Kinetic rate.
TX (or T 2 )
Time to Map
Time to reach the Maximum Acceleration Point (MAP)
from point of injection.
MNTX
Mean Normal Time to Map
The mean of the times of at least 20 normal people to
reach then Maximum Acceleration Point (MAP).
FTR
Fibrinogen Transformation
The amount of fibrinogen converted during a particular
Ratio
time period. This is a percentage of the total Fibrinogen.
ATF
Anticoagulation Therapy
The calculated value used to monitor the uses of an
Factor
anticoagulant without a need for an International
Sensitivity Index (ISI) of a thromboplastin.
nATF
new Anticoagulation Therapy
A replacement for the INR to provide a standardized
Factor
system for monitoring oral anticoagulant therapy. (Also
expressed as ATFt and ATFz)
PR
Prothrombin Ratio
A value computed by dividing a sample PT by the
geometric mean of at least 20 normal people (MNPT).
INR
International Normalized
A parameter which takes into account the various factors
Ratio
involved in anticoagulation therapy monitoring to provide
a standardized system for monitoring oral anticoagulant
therapy.
ATFt
Anticoagulation Therapy
Utilizing a calculated Theoretical End Of Test value and
Factor Theoretical
the Natural Log “e” to removed the need for an MNPT.
XR
Time to MAP Ratio
The value computed by dividing a sample “TX” by the
geometric mean of at least 20 normal people “MNTX”.
[0041] Prior patents for obtaining an anticoagulant therapy factor (ATF) relied on the International Normalized Ratio (INR) system which was derived in order to improve the consistency of results from one laboratory to another. The INR system utilized the calculation of INR from the equation:
[0000] INR=(PT patient /PT geometric mean ) ISI
[0000] wherein the PT patient is the prothrombin time (PT) as an absolute value in seconds for a patient, PT geometric mean is the mean, a presumed number of normal patients. The International Sensitivity Index (ISI) is an equalizing number which a reagent manufacturer of thromboplastin specifies. The ISI is a value which is obtained through calibration against a World Health Organization primary reference thromboplastin standard. Local ISI (LSI) values have also been used to provide a further refinement of the manufacturer-assigned ISI of the referenced thromboplastin in order to provide local calibration of the ISI value.
[0042] For illustration, the present invention can be employed for accurate determination of a new Anticoagulant Therapy Factor (nATF) from a human blood sample, for use during the monitoring of oral anticoagulant therapy, without the need for an ISI or LSI value, and without the need for an INR value as traditionally determined from the above equation (using a patient's prothrombin time and the prothrombin time from a geometric mean of individuals). As is known in the art, blood clotting Factors I, II, V, VII, VIII, IX and X are associated with platelets (Bounameaux, 1957); and, among these, Factors II, VII, IX and X are less firmly attached, since they are readily removed from the platelets by washing (Betterle, Fabris et al, 1977). The role of these platelet-involved clotting factors in blood coagulation is not, however, defined. The present invention provides a method and apparatus for a new Anticoagulant Therapy Factor (nATF) which may be used for anticoagulant therapy monitoring without the need for INR.
[0043] The International Normalized Ratio (INR) is previously discussed in already incorporated reference technical articles entitled “PTs, PRs, ISIs and INRs: A Primer on Prothrombin Time Reporting Part I and II respectively,” published in November, 1993 and December, 1993 issues of Clinical Hemostasis Review . The illustrative example of an analysis which is carried out employing the present invention relies upon the maximum acceleration point (MAP) at which fibrinogen conversion achieves a maximum and from there decelerates, the time to reach the MAP (TX), and the mean normal time to MAP (MNTX), and a fibrinogen transformation rate (FTR), that is, the thrombin activity in which fibrinogen (FBG) is converted to fibrin to cause clotting in blood plasma.
[0044] More particularly, during the clotting steps used to determine the clotting process of a plasma specimen of a patient under observation, a thromboplastin (Tp) activates factor VII which, activates factor X, which, in turn, under catalytic action of factor V, activates factor II (sometimes referred to as prothrombin) to cause factor IIa (sometimes referred to as thrombin) that converts fibrinogen (FBG) to fibrin with resultant turbidity activity which is measured, in a manner as to be described hereinafter, when the reaction is undergoing simulated zero-order kinetics.
[0045] From the above, it should be noted that the thromboplastin (Tp) does not take part in the reaction where factor Ia (thrombin) converts fibrinogen (FBG) to fibrin which is deterministic of the clotting of the plasma of the patient under consideration. The thromboplastin (Tp) only acts to activate factor VII to start the whole cascade rolling. Note also that differing thromboplastins (Tps) have differing rates of effect on factor VII, so the rates of enzyme factor reactions up to II-IIa (the PT) will vary.
[0046] Therefore, the prothrombin times (PTs) vary with the different thromboplastins (Tps) which may have been a factor that mislead authorities to the need of taking into account the International Normalized Ratio (INR) and the International Sensitivity Index (ISI) to compensate for the use of different types of thromboplastins (Tps) during the monitoring of oral anticoagulant therapy. It is further noted, that thromboplastins (Tps) have nothing directly to do with factor Ia converting fibrinogen (FBG) to fibrin, so it does not matter which thromboplastin is used when the fibrinogen transformation is a primary factor.
[0047] The thromboplastin (Tp) is needed therefore only to start the reactions that give factor Ia. Once the factor Ia is obtained, fibrinogen (FBG) to fibrin conversion goes on its own independent of the thromboplastin (Tp) used.
[0048] In one embodiment, the present method and apparatus has use, for example, in coagulation studies where fibrinogen (FBG) standard solutions and a control solution are employed, wherein the fibrinogen standard solutions act as dormant references to which solutions analyzed with the present invention are compared, whereas the control solution acts as a reagent that is used to control a reaction. The fibrinogen standards include both high and low solutions, whereas the control solution is particularly used to control clotting times and fibrinogens of blood samples. It is only necessary to use fibrinogen standards when PT-derived fibrinogens (FBG's) are determined. In connection with other embodiments of the invention, fibrinogen (FBG) standards are not necessary for the INR determination (such as for example INRz described herein).
[0049] Another embodiment provides a method and apparatus for determining an anticoagulation therapy factor which does not require the use of fibrinogen standard solutions. In this embodiment, the apparatus and method may be carried out without the need to ascertain the mean normal prothrombin time (MNPT) of 20 presumed normal patients.
[0050] Where a fibrinogen standard solution is utilized, a fibrinogen (FBG) solution of about 10 g/l may be prepared from a cryoprecipitate. The cryoprecipitate may be prepared by freezing plasma, letting the plasma thaw in a refrigerator and then, as known in the art, expressing off the plasma so as to leave behind the residue cryoprecipitate. The gathered cryoprecipitate should contain a substantial amount of both desired fibrinogen (FBG) and factor VIII (antihemophilic globulin), along with other elements that are not of particular concern to the present invention. The 10 g/l fibrinogen (FBG) solution, after further treatment, serves as the source for the high fibrinogen (FBG) standard. A 0.5 g/l fibrinogen (FBG) solution may then be prepared by a 1:20 (10 g/l/20=0.5 g/l) dilution of some of the gathered cryoprecipitate to which may be added an Owren's Veronal Buffer (pH 7.35) (known in the art) or normal saline solution and which, after further treatment, may serve as a source of the low fibrinogen (FBG) standard.
[0051] The fibrinogen standard can be created by adding fibrinogen to normal plasma in an empty container. Preferably, the fibrinogen standard is formed from a 1:1 fibrinogen to normal plasma solution. For example, 0.5 ml of fibrinogen and 0.5 ml of plasma can be added together in an empty container. Thromboplastin calcium is then added to the fibrinogen standard. Preferably, twice the amount by volume of thromboplastin is added into the container per volume amount of fibrinogen standard which is present in the container. The reaction is watched with the apparatus 10 .
[0052] Then, 1 ml of each of the high (10 g/l) and low (0.5 g/l) sources of the fibrinogen standards may be added to 1 ml of normal human plasma (so the cryoprecipitate plasma solution can clot). Through analysis, high and low fibrinogen (FBG) standards are obtained. Preferably, a chemical method to determine fibrinogen (FBG) is used, such as, the Ware method to clot, collect and wash the fibrin clot and the Ratnoff method to dissolve the clot and measure the fibrinogen (FBG) by its tyrosine content. The Ware method is used to obtain the clot and generally involves collecting blood using citrate, oxalate or disodium ethylenediaminetetraacetate as anticoagulant, typically adding 1.0 ml to about 30 ml 0.85% or 0.90% sodium chloride (NaCl) in a flask containing 1 ml M/5 phosphate buffer and 0.5 ml 1% calcium chloride CaCl 2 , and then adding 0.2 ml (100 units) of a thrombin solution. Preferably, the solution is mixed and allowed to stand at room temperature for fifteen minutes, the fibrin forming in less than one minute forming a solid gel if the fibrinogen concentration is normal. A glass rod may be introduced into the solution and the clot wound around the rod. See Richard J. Henry, M.D., et al., Clinical Chemistry: Principals and Techniques (2 nd Edition) 1974, Harper and Row, pp. 458-459, the disclosure of which is incorporated herein by reference. Once the clot is obtained, preferably the Ratnoff method may be utilized to dissolve the clot and measure the fibrinogen (FBG) by its tyrosine content. See “A New Method for the Determination of Fibrinogen in Small Samples of Plasma”, Oscar D. Ratnoff, M.D. et al., J. Lab. Clin. Med., 1951: V.37 pp. 316-320, the complete disclosure of which is incorporated herein by reference. The Ratnoff method relies on the optical density of the developed color being proportional to the concentration of fibrinogen or tyrosine and sets forth a calibration curve for determining the relationship between optical density and concentration of fibrinogen. The addition of a fibrinogen standard preferably is added to the plasma sample based on the volume of the plasma.
[0053] As is known, the addition of the reagent Thromboplastin C serves as a coagulant to cause clotting to occur within a sample of citrated blood under test which may be contained in a container 8 . As clotting occurs, the A/D converter 26 of FIG. 1 will count and produce a digital value of voltage at a predetermined period, such as once every 0.05 or 0.01 seconds. As more fully described in the previously incorporated by reference U.S. Pat. No. 5,197,017 ('017), these voltage values are stored and then printed by the recorder as an array of numbers, the printing being from left to right and line by line, top to bottom. There are typically one hundred numbers in the five groups representing voltage values every second and hence, one line represents one-fifth of a second in time (20×0.01 seconds). Individual numbers in the same column are twenty sequential numbers apart. Hence, the time difference between two adjacent numbers in a column is one-fifth of a second. The significance of these recorded values may be more readily appreciated after a general review of the operating principles illustrated in FIG. 2 having a Y axis identified as Fibrinogen Concentration (Optical Density) and an X axis identified in time (seconds).
[0054] FIG. 2 illustrates the data point locations of a clotting curve related to a coagulation study which illustrates the activation and conversion of fibrinogen to fibrin. In general, FIG. 2 illustrates a “clot slope” method that may be used in a blood coagulation study carried out for determining a new anticoagulant therapy factor (nATFa). The ATFa represents an anticoagulation therapy factor represented by the expression ATFa=XR (2-nFTR) wherein a maximum acceleration point is obtained, and nFTR=IUX/IUT, where IUX is the change in optical density from a time prior to the MAP time (t <MAP which is t MAP minus some time from MAP) to the optical density at a time after the MAP time (t >MAP which is t MAP plus some time from MAP); and wherein IUT=the change in optical density at the time t 1 to the optical density measured at time t EOT , where time t EOT is the end of the test (EOT). The first delta (IUX) represents the fibrinogen (FBG) for MAP (−a number of seconds) to MAP (+a number of seconds) (that is the fibrinogen (FBG) converted from t <MAP to t >MAP on FIG. 2 ). The (IUT) represents fibrinogen converted from c 1 to c EOT (that is the fibrinogen converted from t 1 to t EOT , see FIG. 2 ). The XR for the ATFa expression is XR=TX/MNTX, which is the ratio of time to map (TX) by the mean normal time to map of 20 presumed “normal” patients.
[0055] The study which measures the concentration of the fibrinogen (FBG) in the plasma that contributes to the clotting of the plasma and uses an instrument, such as, for example, the potentiophotometer apparatus illustrated in FIG. 1 , to provide an output voltage signal that is directly indicative of the fibrinogen (FBG) concentration in the plasma sample under test, is more fully discussed in the previously incorporated by reference U.S. Pat. No. 5,502,651. The quantities given along the Y-axis of FIG. 2 are values (+ and −) that may be displayed by the digital recorder 28 . The “clot slope” method comprises detection of the rate or the slope of the curve associated with the formation of fibrin from fibrinogen. The “clot slope” method takes into account the time to maximum acceleration (TX) which is the point at which fibrinogen conversion achieves a maximum and from there decelerates.
[0056] As seen in FIG. 2 , at time to, corresponding to a concentration c 0 , the thromboplastin/calcium ion reagent is introduced into the blood plasma which causes a disturbance to the composition of the plasma sample which, in turn, causes the optical density of the plasma sample to increase momentarily. After the injection of the reagent (the time of which is known, as to be described, by the computer 30 ), the digital quantity of the recorder 28 of FIG. 1 rapidly increases and then levels off in a relatively smooth manner and then continues along until the quantity c 1 is reached at a time t 0 . The time which elapses between the injection of thromboplastin at to and the instant time t 1 of the quantity c 1 is the prothrombin time (PT) and is indicated in FIG. 2 by the symbol PT. As shown in FIG. 2 , the baseline that develops after the thromboplastin (TP) is introduced or injected into the sample generally is thought to represent the “lag phase” of all of the enzymes preceding prothrombin converting to fibrin. The enzymes types and amounts may vary from person to person, and thus, this would demonstrate the potential for prothrombin times to vary between individuals.
[0057] An anticoagulant therapy factor (nATF) is determined. The optical density of a quantity c 1 directly corresponds to a specified minimum amount of fibrinogen (FBG) that must be present for a measuring system, such as the circuit arrangement of FIG. 1 , to detect in the plasma sample that a clot is being formed, i.e., through the transformation of fibrinogen to fibrin. The quantities shown in FIG. 2 are of optical densities, which may be measured in instrument units, that are directly correlatable to fibrinogen concentration values. The quantity c 1 , may vary from one clot detection system to another, but for the potentiophotometer system of FIG. 1 , this minimum is defined by units of mass having a value of about 0.05 grams/liter (g/l).
[0058] Considering the clotting curve of FIG. 2 , detection of a first predetermined quantity c 1 is illustrated occurring at a corresponding time t 1 , which is the start of the clotting process. In accordance with one or more embodiments, this process may be monitored with the apparatus of FIG. 1 for determining a new anticoagulant therapy factor (nATF). The time t 1 is the beginning point of the fibrinogen formation, that is, it is the point that corresponds to the beginning of the acceleration of the fibrinogen conversion that lasts for a predetermined time, The acceleration of the fibrinogen conversion proceeds from time (t 1 ) and continues until a time t MAP , having a corresponding quantity c MAP . The time t MAP , as well as the quantity CMAP, is of primary importance because it is the point of maximum acceleration of the fibrinogen (FBG) to fibrin conversion and is also the point where deceleration of fibrinogen (FBG) to fibrin conversion begins. Further, the elapsed time from t 0 to t MAP is a time to maximum acceleration from reagent injection (TX), shown in FIG. 2 . Preferably, the conversion of fibrinogen to fibrin is quantified every 0.1 seconds. The time to maximum acceleration from reagent injection (TX) is defined as the point on the clotting curve time line where this conversion has reached its maximum value for the last time, simulating a zero-order kinetic rate. To facilitate ascertainment of the location point of the last maximum value, the delta value of two points at a fixed interval may be measured until this value begins to decrease. This value is tracked for a period of time, such as for example five seconds, after the first decreasing value has been determined. This facilitates ascertainment of the last point of what may be referred to as a simulated zero-order kinetic rate. Referring to FIG. 3 , a zero order kinetic rate is illustrated by the line (L).
[0059] As shown in FIG. 2 , a quantity c MAP and a corresponding time t MAP define a maximum acceleration point (MAP). Fibrin formation, after a short lag phase before the MAP, occurs for a period of time, in a linear manner. Fibrinogen (FBG) is in excess during this lag phase, and fibrin formation appears linear up to the MAP.
[0060] The deceleration of fibrinogen (FBG) to fibrin conversion continues until a quantity c EOT is reached at a time t EOT . The time t EOT is the point where the deceleration of the fibrinogen (FBG) to fibrin conversion corresponds to a value which is less than the required amount of fibrinogen (FBG) that was present in order to start the fibrinogen (FBG) to fibrin conversion process. Thus, because the desired fibrinogen (FBG) to fibrin conversion is no longer in existence, the time t EOT represents the ending point of the fibrinogen (FBG) to fibrin conversion in accordance with the coagulation study exemplified herein, which may be referred to as the end of the test (EOT). The fibrinogen (FBG) to fibrin conversion has a starting point of t 1 and an ending point of t EOT . The differential of these times, t 1 and t EOT , define a second delta (IUT).
[0061] The “clot slope” method that gathers typical data as shown in FIG. 2 has four critical parameters. The first is that the initial delta optical density of substance being analyzed should be greater than about 0.05 g/l in order for the circuit arrangement of FIG. 1 to operate effectively. Second, the acceleration fibrinogen (FBG) to fibrin conversion should be increasing for a minimum period of about 1.5 seconds so as to overcome any false reactions created by bubbles. Third, the total delta optical density (defined by the difference in quantities c 1 and c EOT ) should be at least three (3) times the instrument value in order to perform a valid test, i.e., (3)*(0.05 g/l)=0.15 g/l. Fourth, the fibrinogen (FBG) to fibrin conversion is defined, in part, by the point (t EOT ) where the deceleration of conversion becomes less than the instrument value of about 0.05 g/l that is used to detect the clot point (t 1 ). As with most clot detection systems, a specific amount of fibrinogen needs to be present in order to detect a clot forming. Adhering to the four given critical parameters is an example of how the present apparatus and method may be used to carry out a coagulation study to determine a specific quantity of fibrinogen. In order for that specific amount of fibrinogen to be determined, it is first necessary to detect a clot point (t 1 ). After that clot point (t 1 ) is detected, it logically follows that when the fibrinogen conversion becomes less than the specific amount (about 0.05 g/l for the circuit arrangement of FIG. 1 ), the end point (t EOT ) of the fibrinogen conversion has been reached.
[0062] One embodiment of the method and apparatus is illustrated in accordance with the clotting curve shown in FIG. 3 . The clotting curve of FIG. 3 illustrates the values ascertained in arriving at a new anticoagulation therapy factor (nATFz). The embodiment illustrates the determination of a new anticoagulation therapy factor (nATFz), expressed by the following formula:
[0000] nATFz=XR (2-nFTR) (1)
[0063] This embodiment utilizes a zero order line (L) to obtain a first delta, in particular IUXz, which is a first differential taken along the simulated zero order kinetic line (L), and preferably along the segment between the start of the simulated zero order kinetic (T 2 S) to the last highest absorbance value (T 2 ) (i.e., preferably, the last highest absorbance value of a simulated zero order kinetic). As previously discussed, the acceleration of the fibrinogen conversion proceeds from a first time, here time (T 1 ) and continues, eventually reaching a time where the last highest delta absorbance value or maximum acceleration point (T 2 ) having a corresponding quantity c T2 is reached. The values for “T” correspond with times, and the values for “c” correspond with quantity, which may be measured in instrument units based on optical density readings (also referred to as optical density or o.d.). The time T 2 , as well as the quantity c T2 , is the point of maximum acceleration of the fibrinogen (FBG) to fibrin conversion and is also the point where deceleration of fibrinogen (FBG) to fibrin conversion begins. In this embodiment, IUXz is the change in optical density preferably from the beginning of the at the time T 2 S at which the simulated zero order kinetic begins to the optical density at time T 2 which is the maximum acceleration point or the last highest delta absorbance value of a simulated zero order kinetic. FIG. 3 shows the differential IUXz taken between a preferred segment of the zero order line. The second delta in particular (IUTz) is the change in optical density at the time T 2 S to the optical density measured at time T 3 , where time T 3 is the end of the test (EOT).
[0064] The (IUXz) represents the fibrinogen (FBG) converted between time T 2 S and T 2 . The (IUTz) represents fibrinogen converted from the time T 2 S to the end of the test or T 3 .
[0065] The maximum acceleration ratio (XR) for this embodiment is calculated to arrive at the new alternate anticoagulation therapy factor (nATFz). The maximum acceleration ratio (XR) is defined as the time to maximum acceleration from reagent injection (TX) divided by the mean normal TX value of a number of presumed normal specimens (MNTX). For example, the mean normal TX value may be derived based on the value of 20 or more presumed normal specimens. The maximum acceleration ratio (XR) may be expressed through the following formula:
[0000] XR=TX/MNTX (2)
[0066] The clotting curve of FIG. 3 illustrates the values ascertained in arriving at the new alternate anticoagulation therapy factor (nATFz). The new alternate anticoagulation therapy factor (nATFz) is preferably expressed by the following formula:
[0000] nATFz=XR (2-nFTR) (3)
[0067] with FTR being IUXz/IUTz.
[0068] The preferred IBM-compatible computer 30 of FIG. 1 stores and manipulates these digital values corresponding to related data of FIG. 3 and is preferably programmed as follows:
(a) a sample of blood where the plasma is available, such as, for example, a sample of citrated blood, is obtained and placed in an appropriate container, the computer 30 , as well as the recorder 28 , sequentially records voltage values for a few seconds before injection of theromboplastin. As previously discussed, thromboplastin (tissue factor) is one of the factors in the human body that causes blood to clot. Prothrombin is another. Fibrinogen is yet another. Before injection of the thromboplastin, the output from the A/D converter 26 is relatively constant. When thromboplastin is injected into the plasma sample in the container, a significant and abrupt change occurs in the recorded voltage values of both the computer 30 and the recorder 28 . This abrupt change is recognized by both the recorder 28 and, more importantly, by the computer 30 which uses such recognition to establish T o . The computer 30 may be programmed so as to correlate the digital quantities of the A/D converter 26 to the analog output of the detector means photocell 10 which, in turn, is directly correlatable to the fibrinogen (FBG) concentration g/l of the sample of blood discussed with reference to FIG. 3 ; (b) the computer 30 may be programmed to look for a digital quantity representative of a critical quantity c 1 , and when such occurs, record its instant time T 1 . (The time span between T o and T 1 is the prothrombin time (PT), and has an normal duration of about 12 seconds, but may be greater than 30 seconds); (c) following the detection of the quantity c 1 , the computer 30 may be programmed to detect for the acceleration of fibrinogen (FBG) to fibrin conversion. The computer 30 is programmed to detect the maximum acceleration quantity c MAP or c T2 as illustrated in FIG. 3 , and its corresponding time of occurrence t MAP , which is T 2 in FIG. 3 . (d) the computer detects a quantity c EOT occurring at time t EOT . Typically, it is important that the rate of fibrin formation increase for at least 1.5 seconds following the occurrence of (T 1 ); (e) The computer 30 is programmed to ascertain the value for the time to start (T 2 S) which corresponds with the time at which the simulated zero order kinetic rate begins. (f) following the detection of the acceleration of fibrinogen conversion to detect the start time T 2 S, the computer 30 is programmed to detect for a deceleration of the fibrinogen conversion, wherein the fibrinogen concentration decreases from a predetermined quantity c MAP to a predetermined quantity c EOT having a value which is about equal but less than the first quantity c 1 . The computer is programmed to ascertain a first delta (IUTz), by determining the difference between the quantity c T2S and the quantity c EOT ; and a second delta (IUXz) by determining the difference between the quantity c T2S and the quantity c 2 (or c MAP ). (g) the computer 30 manipulates the collected data of (a); (b); (c); (d); (e) and (f) above, to determine the new fibrinogen transfer rate (nFTR). The nFTR may be arrived at based on the principle that if a required amount (e.g., 0.05 g/l) of fibrinogen concentration c 1 is first necessary to detect a clot point (T 1 ); then when the fibrinogen concentration (c EOT ) becomes less than the required amount c 1 , which occurs at time (T EOT ), the fibrinogen end point has been reached. More particularly, the required fibrinogen concentration c 1 is the starting point of fibrinogen conversion of the clotting process and the less than required fibrinogen concentration c EOT is the end point of the fibrinogen conversion of the clotting process. (h) The computer now has the information needed to determine the new fibrinogen transfer rate (nFTRz) which is expressed by the following formula:
[0000] nFTRz=IUXz/IUTz (4) (i) data collected is manipulated by the computer 30 to calculate the maximum acceleration ratio (XR), which is expressed as TX divided by the mean normal TX value of at least 20 presumed normal specimens (MNTX):
[0000] XR=TX/MNTX (2)
[0000] The MNTX value may be ascertained and stored in the computer for reference.
(j) the computer 30 now has the information needed to determine the nATFz, (also referred to as INRz) which typically is expressed as:
[0000] nATFz or INRz=XR (2-nFTR) (3)
[0079] where, in the exponent, the value 2 is the logarithm of the total fibrinogen, which, as expressed in terms of the optical density, is 100% transmittance, the log of 100 being 2.
[0080] The new anticoagulation therapy factor (nATFz) does not require an ISI value, as was previously used to determine anticoagulation therapy factors. The new anticoagulation therapy factor (nATFz) uses for its ascertainment the values extracted from the clotting curve (see FIG. 3 ), in particular (nFTRz) (determined based on IUXz and IUTz), and (TX). In carrying out coagulation studies, the new anticoagulant therapy factor (nATFz) may replace INR in anticoagulant therapy management.
[0081] The apparatus and method for obtaining a new anticoagulant therapy factor, (nATFz), may be accomplished without encountering the complications involved with obtaining the prior art quantities International Normalized Ratio (INR) and International Sensitivity Index (ISI).
[0082] The new anticoagulant therapy factor (nATFz or ATF) preferably is a replacement for the International Normalized Ratio (INR), hence it may be referred to as INRz. Existing medical literature, instrumentation, and methodologies are closely linked to the International Normalized Ratio (INR). The nATFz was compared for correlation with the INR by comparative testing, to INR quantities, even with the understanding that the INR determination may have an error of about ten (10) % which needs to be taken into account to explain certain inconsistencies.
[0083] Table 2, below, includes anticoagulant therapy factors obtained from patients at two different hospitals. The ATFz values were obtained, with GATFz representing one geographic location where patients were located and MATFz being another location. The ATFz was obtained as the new anticoagulant therapy factor, and as illustrated in Tables 4 and 5, below, compares favorably to results obtained for INR determinations.
[0084] Another alternate embodiment for determining a new anticoagulant therapy factor (ATFt) is provided. The alternate embodiment for determining ATFt eliminates the need for determining a mean normal prothrombin time (MNPT) (or MNXT) and ISI, saving considerable time and costs, and removing potential sources of error, as the MNPT (the expected value of MNPT's depending on the varying 20 presumed normals population) and ISI (generally provided by the manufacturer of the reagent—such as, for example, the thromboplastin, etc.) are not required for the determination of the ATFt. An alternate embodiment for determining ATFt is illustrated in accordance with the clotting curve shown in FIG. 4 . The clotting curve of FIG. 4 illustrates values ascertained in arriving at the alternate new anticoagulation therapy factor (nATFt). The alternate new anticoagulation therapy factor (nATFt) is preferably expressed by the following formula:
[0000] nATFt=Value 1*Value 2 (4)
[0085] The alternate embodiment utilizes the zero order line (L) to obtain a first delta, in particular IUXz, which is a first differential taken along the simulated zero order kinetic line (L), and preferably along the segment between the start of the simulated zero order kinetic (T 2 S) to the last highest absorbance value (T 2 ) (i.e., preferably, the last highest absorbance value of a simulated zero order kinetic). As previously discussed, the acceleration of the fibrinogen conversion proceeds from a first time, here time (T 1 ) and continues, eventually reaching a time where the last highest delta absorbance value or maximum acceleration point (T 2 ) having a corresponding quantity c T2 is reached. The time T 2 , as well as the quantity c T2 , is the point of maximum acceleration of the fibrinogen (FBG) to fibrin conversion and also is the point where deceleration of fibrinogen (FBG) to fibrin conversion begins. As illustrated on the clotting chart in FIG. 4 , IUXz represents a change in optical density (o.d.) preferably from the beginning of the at the time T 2 S at which the simulated zero order kinetic begins to the optical density at time T 2 which is the maximum acceleration point or the last highest delta absorbance value of a simulated zero order kinetic. The value IUXz is generally expressed in instrument units (corresponding to absorbance or percent transmittance) and may generally be referred to as optical density or o.d. FIG. 4 shows the differential IUXz taken between a preferred segment of the zero order line. The second delta in particular (IUTz) represents a change in optical density at a time T 2 S to the optical density measured at a time T 3 , where time T 3 is the end of the test (EOT).
[0086] The (IUXz) represents the fibrinogen (FBG) converted between time T 2 S and T 2 . The (IUTz) represents fibrinogen converted from the time T 2 S to the end of the test or T 3 .
[0087] The first value V1 corresponds to the value determined for the theoretical end of test (TEOT), which, as illustrated in the clotting curve representation in FIG. 4 , is where the zero order kinetic line (L) crosses the line y=T 3 . The value TEOT is the elapsed time to convert the total instrument units (TIU) at the zero order kinetic rate, which is representative of the fibrinogen in the sample undergoing the conversion to fibrin. In other words, the expression for the first value (V1), or TEOT, is:
[0000] V 1=TEOT=ZTM/IUXz*IUTz (5)
[0000] where ZTM is the time between Tmap (i.e., T 2 shown on FIG. 4 ) and T2S. ZTM may be generally represented by the following expression:
[0000] ZTM= T 2 −T 2 S (6)
[0088] A second value, V2, also referred to as a multiplier, is determined based on the value T 2 S. In the expression for the ATFt, the second value, V2, may be obtained by taking the value of the time (T 2 S) corresponding to a second time (t2) or the maximum acceleration point (Tmap), and scaling this value. It is illustrated in this embodiment that the multiplier is derived from the natural log base “e”, which is 2.71828, scaled to provide an appropriately decimaled value. The scaling number used in the example set forth for this embodiment is 100. The second value (V2) may be expressed by the following relationship:
[0000] V 2 =T 2 S/ 100 e (7)
[0000] where T 2 S is the maximum acceleration point for the sample, and 100e is the value 100 multiplied by the natural log base “e” (2.71828) or 271.828. The new anticoagulation therapy factor according to the alternate embodiment may be expressed as follows:
[0000] nATFt=[( T 2 −T 2 S )/IUXz*IUTz]*[ T 2 S/M] (8)
[0000] where M represents a multiplier. In the present example, the multiplier M, corresponds to the value 271.828 (which is 100 times the natural log base “e”).
[0089] An alternate embodiment of an anticoagulant therapy factor, ATFt2, which does not require the ascertainment of a mean normal prothrombin time (MNPT) or use of an ISI value, is derived using the expression (5), wherein the IUTz is replaced by the expression (IUTz+IULz). In this alternate expression the method is carried out to ascertain the values for Value1 and Value2, in the manner described herein, with Value 1 being obtained through expression (5.1):
[0000] V 1=TEOT=ZTM/IUXz*(IUTz+IULz) (5.1)
[0000] where IULz is time to convert the lag phase fibrinogen (FBG) measured along the ordinate between T1 and T2S. In expression 5.1, the theoretical end of test (TEOT) is set to include the time to convert the fibrinogen (FBG) in the lag phase of the clotting curve. FIG. 5 illustrates the fibrinogen lag phase and the TEOT obtained from the line L2, and shows the IULz. ATFt2 is expressed by the following:
[0000] nATFt2=[( T 2 −T 2 S )/IUXz*(IUTz+IULz)]*[ T 2 S/M] (8.1)
[0090] The apparatus may comprise a computer which is programmed to record, store and process data. The zero order rate may be determined by ascertaining data from analyzing the sample, and optical density properties. One example of how this may be accomplished is using two arrays, a data array and a sub array. A data array may be ascertained by collecting data over a time interval. In one embodiment, for example, the data array may comprise a sequential list of optical densities, taken of a sample by an optical analytical instrument, such as, for example, a spectrophotometer, for a frequency of time. In the example, the frequency of sample data is taken every 100 th of a second. In this embodiment, a computer is programmed to record the optical density of the sample, every 100 th of a second. Two values, NOW and THEN, for the data array are provided for ascertaining the Prothrombin Time (PT) (which is the time point T 1 ), maximum acceleration point (MAP), and end of test point (EOT). Two time definitions may be specified, one being the interval between NOW and THEN on the clotting curve, which may be 2.72 seconds (272/100 th of a second), the second being the size of the filter used for signal averaging. NOW is the sum of the last 20 optical densities and THEN is the sum of the 10 prior data points 2.72 seconds prior to NOW. A graphical illustration is provided in FIG. 5 . As illustrated in FIG. 5 , four values are defined: SUM(NOW), SUM(THEN), AVERAGE(NOW) and AVERAGE(THEN). The average is the sum divided by the filter value.
[0091] The sub array may be defined as a sequential list of delta absorbance units. This may begin at T 1 , the prothrombin time (PT), and continue until the last highest delta absorbance (delta A) has been detected, then continues an additional five (5) seconds to insure the last delta A has been found. A determination of T 2 S may be accomplished by locating within the sub array, the first occurrence of when the sub array delta value is greater than or equal to 80% of the highest delta absorbance units. The first derivative is ascertained by computing the difference between (NOW) and (THEN). The PT is ascertained by determining the point prior to the positive difference between AVERAGE(THEN) and AVERAGE(NOW) for a period of 2.72 seconds or 272 ticks. The MAP is the point where the last highest difference between SUM(THEN) and SUM(NOW) has occurred. The computer may be programmed to store this delta A value in the sub array. The EOT may be ascertained by determining the point prior to where the difference between SUM(THEN) and SUM(NOW) is less than one.
[0092] Table 2 illustrates examples of samples, identified by ID numbers, along with corresponding data which compares the ATF values obtained for an ATF determined through the prior method, using ISI and INR values (represented as ATFa), an ATF determined through the use of a zero order kinetic reaction using the MNTX (nATFz), and an ATF determined without using the MNXT or ISI (nATFt). The data in table 2 represents universal laboratory data from combined locations for the patients listed. The data is based on analysis of absorbance data, storage of the data by the computer, such as, for example, with a storage device, like a hard drive, and retrieving the data and processing the data. The data, in the example represented in Table 2 was processed using the definitions and NOW and THEN intervals.
[0000]
TABLE 2
ID
AINR
GINR
GatfA
GatfZ
GatfT
MINR
MatfA
MatfZ
MatfT
U0047
2.10
1.70
1.76
1.74
1.62
2.00
2.08
1.78
1.68
U0048
1.80
1.80
1.84
1.83
1.72
1.90
1.96
1.85
1.82
U0050
1.80
1.70
1.77
1.80
1.68
1.90
2.00
1.80
1.70
U0056
1.60
1.50
1.54
1.54
1.40
1.80
1.83
1.61
1.48
U0058
3.20
2.80
2.93
2.92
2.93
3.30
3.38
3.10
3.29
U0060
2.20
2.10
2.15
2.17
2.11
2.20
2.21
2.26
2.27
U0062
2.80
2.60
2.69
2.72
2.69
3.00
3.19
2.86
2.91
U0415
0.90
0.90
0.88
0.94
0.74
0.90
0.95
0.97
0.83
U0432
1.80
1.50
1.53
1.42
1.24
1.40
1.39
1.46
1.33
U0436
2.40
2.40
2.57
2.24
1.99
2.40
2.41
2.28
2.17
U0438
3.90
3.70
4.25
3.26
3.21
3.80
4.22
3.40
3.55
U0439
2.30
2.20
2.27
1.94
1.75
2.30
2.32
2.07
2.02
U0440
5.80
4.80
5.41
4.33
4.50
4.60
4.84
4.55
5.18
U0441
4.50
4.90
5.58
5.01
4.86
4.40
4.71
4.64
5.35
U0442
1.80
1.70
1.79
1.65
1.48
1.80
1.84
1.64
1.52
U0800
2.00
2.00
2.02
1.78
1.64
2.10
2.11
2.12
2.09
U0843
1.40
1.40
1.43
1.42
1.22
1.40
1.47
1.44
1.31
U0848
1.30
1.40
1.41
1.31
1.13
1.30
1.37
1.34
1.23
U0849
2.40
2.30
2.44
1.94
1.77
2.30
2.38
1.98
1.93
U0855
1.30
1.30
1.29
1.35
1.17
1.20
1.24
1.36
1.22
U0860
1.00
1.00
0.99
1.00
0.77
1.00
0.97
1.00
0.85
U0861
2.80
2.90
2.98
2.70
2.58
3.00
2.99
2.88
3.00
U0863
1.70
1.70
1.70
1.76
1.65
1.70
1.77
1.83
1.79
U0867
3.20
2.90
3.19
2.64
2.38
3.00
3.10
2.85
2.83
U0875
2.20
2.00
2.16
1.80
1.60
2.00
2.02
1.81
1.71
U1198
2.20
2.10
2.17
2.07
1.91
2.00
1.98
2.22
2.22
U1199
2.80
3.30
3.57
2.79
2.76
3.20
3.21
2.99
3.28
U1201
1.90
1.90
1.95
1.76
1.62
1.80
1.84
1.82
1.80
U1202
1.30
1.30
1.35
1.31
1.16
1.40
1.39
1.35
1.20
U1205
1.60
1.80
1.90
1.71
1.53
1.90
1.90
1.80
1.67
U1207
1.90
1.90
1.96
1.68
1.49
1.90
1.87
1.78
1.61
U1218
3.00
2.60
2.86
2.57
2.56
2.80
3.07
2.90
3.08
U1225
2.20
2.30
2.34
2.01
1.83
2.60
2.40
2.21
2.16
U1230
1.30
1.40
1.45
1.47
1.32
1.40
1.45
1.50
1.45
U1575
1.40
1.30
1.30
1.53
1.41
1.40
1.44
1.49
1.35
U1576
2.20
2.10
2.11
2.10
2.02
2.30
2.32
2.19
2.17
U1579
1.50
1.70
1.72
1.64
1.49
1.80
1.81
1.61
1.44
U1581
1.70
1.70
1.74
1.85
1.81
1.70
1.77
1.74
1.73
U1599
2.00
1.70
1.78
2.01
1.96
2.00
2.14
2.04
1.93
U1600
3.50
3.30
3.39
3.58
3.63
3.90
4.21
3.37
3.64
U1649
0.90
0.80
0.80
0.94
0.76
0.90
0.89
0.89
0.74
U3050
2.70
2.80
3.08
2.34
2.17
2.30
2.34
2.05
2.02
U3077
1.30
1.40
1.44
1.34
1.17
1.30
1.28
1.31
1.16
U3083
1.60
1.60
1.58
1.47
1.31
1.60
1.68
1.48
1.37
U3395
2.70
3.20
3.51
2.80
2.70
2.80
2.90
2.38
2.32
U3398
1.50
1.70
1.77
1.60
1.47
1.60
1.65
1.61
1.47
U3408
1.10
1.20
1.18
1.13
0.92
1.10
1.03
1.09
0.94
U3453
1.10
1.20
1.24
1.19
0.97
1.20
1.18
1.11
1.00
U3456
1.10
1.00
0.96
0.99
0.81
1.00
0.98
1.04
0.90
U3457
2.20
2.30
2.38
2.03
1.94
2.10
2.28
1.94
1.86
U3459
2.90
2.60
2.81
2.40
2.22
2.40
2.53
2.11
2.04
U3724
2.70
2.40
2.47
2.16
1.95
2.60
2.72
2.31
2.25
U4471
1.50
1.60
1.67
1.63
1.43
1.70
1.71
1.71
1.62
U4737
2.90
2.60
2.79
2.42
2.26
2.70
2.87
2.51
2.42
U4752
1.40
1.50
1.55
1.47
1.26
1.50
1.48
1.46
1.33
U4757
2.00
2.10
2.09
1.95
1.77
2.00
2.02
2.00
1.92
U4767
2.60
2.40
2.52
2.16
1.95
2.60
2.56
2.33
2.27
U4772
2.50
2.70
2.78
2.59
2.58
2.80
2.84
2.55
2.56
U4801
1.30
1.40
1.41
1.33
1.13
1.50
1.49
1.41
1.22
U5133
0.90
0.90
0.91
0.92
0.74
1.00
0.97
0.97
0.78
U5158
5.50
5.10
5.90
5.34
5.64
6.00
6.57
6.50
7.00
U5169
2.60
2.90
3.16
3.14
3.09
3.20
3.35
3.35
3.67
U5173
1.10
1.20
1.17
1.19
1.02
1.20
1.21
1.16
1.03
U5175
1.70
1.80
1.86
1.85
1.67
1.90
1.92
1.82
1.70
U5178
2.30
2.20
2.28
2.02
1.79
2.60
2.85
2.03
2.01
U5183
2.90
2.60
2.83
2.43
2.23
3.60
3.86
2.88
3.01
U5190
2.80
2.70
2.82
2.85
2.70
3.20
3.36
3.00
3.15
U5193
3.10
3.00
3.13
2.93
2.81
3.60
3.73
3.33
3.30
U5565
2.70
3.20
3.34
3.16
3.04
3.50
3.48
3.31
3.50
U5589
1.60
1.80
1.86
1.69
1.52
1.90
1.96
1.64
1.44
U5591
2.00
2.20
2.33
2.16
1.98
2.30
2.28
2.19
2.24
U5592
1.10
1.20
1.23
1.26
1.09
1.40
1.35
1.49
1.37
U5593
1.70
1.80
1.89
1.76
1.55
1.80
1.85
1.76
1.70
U5594
2.30
2.60
2.79
2.84
2.81
2.80
2.84
2.85
2.96
U5597
3.30
3.30
3.64
3.25
2.96
4.10
4.03
3.85
4.08
U5992
1.40
1.40
1.42
1.45
1.29
1.30
1.37
1.37
1.30
U5993
1.00
0.90
0.94
1.03
0.84
1.00
0.98
1.03
0.84
U6017
1.00
0.90
0.95
0.99
0.77
0.90
0.89
0.97
0.79
U6047
2.30
2.30
2.36
2.17
1.97
2.20
2.28
2.23
2.22
U6056
1.00
1.00
1.01
1.03
0.87
1.00
1.01
1.02
0.85
U6060
1.90
2.10
2.17
2.10
1.94
2.30
2.00
2.16
2.12
U6065
3.10
2.80
2.93
2.77
2.60
3.00
3.13
2.74
2.76
U6928
1.20
1.20
1.17
1.34
1.17
1.20
1.24
1.22
1.05
U6929
1.20
1.20
1.20
1.23
1.06
1.20
1.19
1.15
0.98
U6936
2.40
2.50
2.45
3.02
3.15
2.60
2.61
2.51
2.60
U6938
2.10
2.10
2.12
2.30
2.22
2.30
2.26
2.25
2.21
U6951
1.50
1.50
1.51
1.59
1.42
1.60
1.66
1.49
1.36
U6972
2.40
2.40
2.47
2.57
2.49
2.80
2.84
2.54
2.51
U6977
1.30
1.30
1.34
1.35
1.19
1.30
1.37
1.23
1.08
U6987
5.10
4.50
4.43
5.29
5.42
5.70
5.44
6.16
6.82
U7316
1.20
1.10
1.15
1.28
1.14
1.30
1.28
1.26
1.11
U7317
2.00
1.60
1.68
1.66
1.56
1.90
1.90
1.68
1.56
U7318
2.80
2.70
2.86
2.71
2.57
3.30
3.40
2.70
2.72
U7320
2.00
1.90
1.92
2.17
2.13
2.00
2.06
2.12
2.13
U7321
1.50
1.40
1.38
1.59
1.50
1.60
1.60
1.61
1.51
U7322
1.80
1.70
1.72
1.63
1.46
1.70
1.76
1.55
1.42
U7324
1.30
1.20
1.25
1.33
1.17
1.40
1.40
1.30
1.13
U7440
2.60
3.00
2.98
2.90
2.89
3.00
3.01
3.05
3.37
U7443
2.00
2.00
2.03
1.87
1.73
2.10
2.17
1.90
1.79
U7458
1.40
1.40
1.43
1.38
1.20
1.40
1.40
1.40
1.26
U7465
9.70
7.40
8.12
6.47
7.80
7.10
7.54
7.06
7.63
U7469
1.10
1.10
1.11
1.11
0.86
1.20
1.14
1.10
0.90
U7470
3.20
3.40
3.65
3.27
3.12
3.60
3.67
3.62
3.70
U7707
2.20
2.20
2.27
2.34
2.28
2.30
2.29
2.23
2.22
U7708
1.60
1.60
1.60
1.73
1.61
1.70
1.73
1.71
1.62
U7710
2.30
2.50
2.64
2.71
2.73
2.70
2.85
2.75
2.96
U7713
1.40
1.60
1.59
1.57
1.50
1.60
1.64
1.58
1.48
U7724
2.40
2.40
2.47
2.62
2.65
2.70
2.73
2.75
2.84
U7727
1.70
1.70
1.73
1.78
1.68
1.90
1.90
1.91
1.86
U7738
2.40
2.30
2.45
2.27
2.21
2.40
2.54
2.29
2.32
U7794
1.90
1.80
1.91
1.72
1.58
1.70
1.78
1.71
1.55
U8080
3.10
3.60
3.63
3.41
3.54
3.30
3.33
3.18
3.34
U8087
1.90
1.90
1.95
1.80
1.62
1.90
1.91
1.79
1.74
U8092
1.70
1.70
1.76
1.67
1.49
1.90
1.93
1.67
1.57
U8210
2.60
2.90
3.04
2.72
2.63
2.70
2.77
2.54
2.56
U8221
3.20
3.70
3.99
3.42
3.35
3.50
3.47
3.24
3.46
U8555
2.60
2.40
2.54
2.56
2.52
2.90
3.09
2.57
2.56
U8558
2.30
2.20
2.26
2.16
2.15
2.30
2.33
2.31
2.35
U8559
1.60
1.40
1.45
1.42
1.24
1.60
1.65
1.45
1.28
U8563
2.20
2.30
2.30
2.32
2.30
2.40
2.43
2.34
2.42
U8570
1.20
1.20
1.20
1.34
1.23
1.20
1.21
1.35
1.25
U8575
0.90
0.80
0.84
0.96
0.80
0.90
0.89
0.95
0.78
U9031
2.10
2.40
2.33
2.42
2.42
2.60
2.38
2.34
2.35
U9032
1.70
1.70
1.75
1.78
1.58
1.90
1.93
1.68
1.53
U9034
3.00
2.90
2.82
3.79
3.97
3.40
3.37
3.49
3.80
U9039
2.70
3.00
3.17
2.99
3.03
3.20
3.20
3.12
3.27
U9040
1.40
1.40
1.44
1.36
1.20
1.40
1.39
1.33
1.15
U9049
3.50
3.30
3.46
3.33
3.45
3.60
3.77
3.33
3.72
U9055
2.40
2.10
2.14
2.15
2.04
2.40
2.39
2.15
2.13
[0093] A statistical comparison of the above data from Table 2 is presented below in Tables 4 and 5. The value AINR in Table 2 represents the INR value obtained pursuant to the World Health Organization (WHO), using expressions (A) and (B) above. GINR and MINR correspond to INR values used to determine the comparison data set forth in Tables 4 and 5.
[0094] The determination of the new anticoagulant therapy factor (ATFt) may be carried out with a computer. According to one example, the gathering, storing, and manipulation of the data generally illustrated in FIG. 4 , may be accomplished by computer 30 of FIG. 1 that receives digital voltage values converted, by the A/D converter 26 , from analog voltage quantities of the photocell 10 detection means.
[0095] In accordance with one embodiment, the IBM-compatible computer 30 of FIG. 1 stores and manipulates these digital values corresponding to related data of FIG. 4 and may be programmed as follows:
(a) a sample of blood where the plasma is available, such as, for example, a sample of citrated blood, is obtained and placed in an appropriate container, the computer 30 , as well as the recorder 28 , sequentially records voltage values for a few seconds before injection of thromboplastin. As previously discussed, thromboplastin (tissue factor) is one of the factors in the human body that causes blood to clot. Prothrombin is another. Fibrinogen is yet another. Before injection of the thromboplastin, the output from the A/D converter 26 is relatively constant. When thromboplastin is injected into the plasma sample in the container, a significant and abrupt change occurs in the recorded voltage values of both the computer 30 and the recorder 28 . This abrupt change is recognized by both the recorder 28 and, more importantly, by the computer 30 which uses such recognition to establish T o . The computer 30 may be programmed so as to correlate the digital quantities of the A/D converter 26 to the analog output of the detector means photocell 10 which, in turn, is directly correlatable to the fibrinogen (FBG) concentration g/l of the sample of blood discussed with reference to FIG. 3 ; (b) the computer 30 may be programmed to look for a digital quantity representative of a critical quantity c 1 , and when such occurs, record its instant time T 1 . (The time span between T o and T 1 is the prothrombin time (PT), and has an normal duration of about 12 seconds, but may be greater than 30 seconds); (c) following the detection of the quantity c 1 , the computer 30 may be programmed to detect for the acceleration of fibrinogen (FBG) to fibrin conversion. The computer 30 is programmed to detect the maximum acceleration quantity c MAP or c T2 as illustrated in FIG. 3 , and its corresponding time of occurrence t MAP , which is T 2 in FIG. 3 . (d) the computer detects a quantity c EOT occurring at time t EOT . Typically, it is important that the rate of fibrin formation increase for at least 1.5 seconds following the occurrence of (T 1 ); the computer determines a theoretical end of test (TEOT) based on the determination of the zero order kinetic rate. The computer may be programmed to determine the zero order rate, which is expressed as a Line (L) in FIG. 4 . The TEOT may be determined by the corresponding time value (TEOT) along the line L which corresponds with the quantity c EOT (i.e., that quantity corresponding to the time, T 3 ). (e) following the detection of the maximum acceleration quantity c T2 (also representing c MAP ) and the time T 2 (also representing t MAP ) both of which define the maximum acceleration point (MAP), and the TEOT, the computer is programmed to determine a new fibrinogen transformation rate (nFTR) covering a predetermined range starting prior to the maximum acceleration point (MAP) and ending after the maximum acceleration point (MAP). The elapsed time from T 0 to T 2 (which is t MAP ) is the time to maximum acceleration (TMA), shown in FIG. 4 , and is represented by TX (i.e., time to MAP); The new fibrinogen transformation rate (nFTR) has an upwardly rising (increasing quantities) slope prior to the maximum acceleration point (MAP) and, conversely, has a downwardly falling (decreasing quantities) slope after the maximum acceleration point (MAP). The computer 30 is programmed to ascertain the value for the time to start (T 2 S) which corresponds with the time at which the simulated zero order kinetic rate begins. (f) following the detection of the acceleration of fibrinogen conversion to detect the start time T 2 S, the computer 30 is programmed to detect for a deceleration of the fibrinogen conversion, wherein the fibrinogen concentration decreases from a predetermined quantity c MAP to a predetermined quantity c EOT having a value which is about equal but less than the first quantity c 1 . The computer is programmed to ascertain a first delta (IUTz), by determining the difference between the quantity c T2S and the quantity c EOT ; and a second delta (IUXz) by determining the difference between the quantity c T2S and the quantity c 2(or CMAP). ; the computer also determines the value ZTM by determining the difference between the time T 2 (which is Tmap) and the time T 2 S; (g) the computer 30 manipulates the collected data of (a); (b); (c); (d), (e) and (f) above, to determine the new fibrinogen transfer rate (nFTR). The nFTR may be arrived at based on the principle that if a required amount (e.g., 0.05 g/l) of fibrinogen concentration c 1 is first necessary to detect a clot point (t 1 ); then when the fibrinogen concentration (c EOT ) becomes less than the required amount c 1 , which occurs at time (t EOT ), the fibrinogen end point has been reached. More particularly, the required fibrinogen concentration c 1 is the starting point of fibrinogen conversion of the clotting process and the less than required fibrinogen concentration c EOT is the end point of the fibrinogen conversion of the clotting process. (h) the duration of the fibrinogen conversion of the clotting process of the present invention is defined by the zero order time period between T EOT and T 2 S and is generally indicated in FIG. 3 as IUTz. The difference between the corresponding concentrations c T2S and cT2 is used to define a delta IUXz. The computer now has the information needed to determine the TEOT, which is expressed by the following formula:
[0000] TEOT=ZTM/IUXz*IUTz (5) The value TEOT may be assigned VALUE 1; (i) data collected is manipulated by the computer 30 to calculate a second value, VALUE 2, using T 2 S and a multiplier M (which in this example, in expression 7 below, is a fraction). The computer may be programmed to use as a multiplier a value based on the natural log base “e” (which is 2.71828), scaled by a scaling value. Here, the scaling value is 100, and the multiplier may be expressed as follows:
[0000] M=100e (9) VALUE 2 is determined using the information which the computer has ascertained and stored, by the following expression:
[0000] VALUE 2 =T 2 S/ 100 e (7)
[0000] The data may be ascertained and stored in the computer for reference.
(j) the computer 30 now has the information needed to determine the nATFt, which typically is expressed as:
[0000] nATFt=VALUE 1*VALUE 2 (4)
[0110] The computer 30 may be used to manipulate and derive the quantities of expression (4) to determine a new anticoagulant therapy factor nATFt utilizing known programming routines and techniques. The data collected by a computer 30 may be used to manipulate and derive the new anticoagulant therapy factor (nATFt) of expression (4). Similarly, one skilled in the art, using known mathematical techniques may derive the theoretical end of test TEOT of expression (5) and the second value VALUE 2 of expression (7) which, in turn, are used to determine the new anticoagulant therapy (nATFt) of expression (4). In the nATFt determination, the determination is based on the patient's own sample, and does not rely on the determination of normal prothrombin times for the reagent used (e.g., thromboplastin, innovin or the like). With the nATFt, no longer does the accuracy of the quantities determined depend, in whole or part, on the number of specimens used, that is, the number of stable (or presumed stable) patients.
[0111] The new anticoagulation therapy factor (nATFt) does not require an ISI value, as was previously used to determine anticoagulation therapy factors. The new anticoagulation therapy factor (nATFt) uses for its ascertainment the values extracted from the clotting curve (see FIG. 4 ), in particular T 2 S, Tmap, TEOT, c T2S , cmap and ceot. In determining the new anticoagulant therapy factor (nATFt), the ISI is not required, nor is the MNPT, or the need to obtain and calculate the prothrombin times (PT's) for 20 presumed normal patients. In carrying out coagulation studies, the new anticoagulant therapy factor (nATFt) may replace INR in anticoagulant therapy management. In addition, using the sample from the patient, the computer 30 has knowledge of the values obtained for the fibrinogen reaction, to ascertain the (nATFt).
[0112] It should now be appreciated that the present invention provides an apparatus and method for obtaining a new anticoagulant therapy factor (nATF) without encountering the complications involved with obtaining the prior art quantities International Normalized Ratio (INR) and International Sensitivity Index (ISI).
[0113] The new anticoagulant therapy factor (nATFt) preferably is a replacement for the International Normalized Ratio (INR). Existing medical literature, instrumentation, and methodologies are closely linked to the International Normalized Ratio (INR). The nATFt was compared for correlation with the INR by comparative testing, to INR quantities, even with the understanding that the INR determination may have an error of about +/−15%, at a 95% confidence interval, which needs to be taken into account to explain certain inconsistencies.
[0114] The hereinbefore description of the new anticoagulant therapy factor (nATFt) does correlate at least as well as, and preferably better than, studies carried out using the International Normalized Ratio (INR). For some comparisons, see the tables below, and in particular Table 4 and Table 5.
[0115] Table 3 (Part A) and Table 3 (Part B) provide corresponding data for a coagulation study. In Table 3 (Part A and B), the following references are used:
[0000]
Column
Label
Definition
A
ID
Sample ID
B
OD@T 2 S
OD at the start of Zero Order Kinetic
C
OD@Map
OD at the Maximum Acceleration Point
(MAP)
D
OD@Eot
OD at the END OF TEST (Eot)
E
ΔT 2 SMap
Delta of Column B and C creating the IUXz
F
ΔT 2 SEot
Delta of Column B and D creating the IUTz
G
FTR od
Ratio of Column E divided by F
The FTR od is subtracted from 2 creating the
Exponent that replaces the ISI
H
Time@T 2 S
Time at the start of Zero Order Kinetics
I
Time@Map
Time at the Maximum Acceleration Point
(MAP)
J
Time@TEot
Time at the Theoretical End of Test (TEOT)
K
ΔT 2 SMap
Delta of Column H and I creating the IUXz
(and ZTM)
L
ΔT 2 STEot
Delta of Column H and J creating the IUTz
M
FTR Time
Ration of Column K divided by L
[0000]
TABLE 3
(Part A)
ID
OD@T2S
OD@Map
OD@Eot
ΔT2SMap
ΔT2SEot
A001
3719
3707
3664
12
55
A002
3713
3704
3686
9
27
A003
3729
3720
3705
9
24
A004
3708
3696
3663
12
45
A005
3727
3715
3700
12
27
A007
3725
3718
3698
7
27
A008
3714
3693
3646
21
68
A009
3727
3716
3697
11
30
A010
3727
3714
3701
13
26
A011
3690
3676
3647
14
43
A012
3728
3716
3695
12
33
A013
3715
3690
3641
25
74
A014
3717
3708
3694
9
23
A015
3726
3718
3706
8
20
A016
3722
3715
3678
7
44
A017
3720
3707
3681
13
39
A018
3723
3709
3697
14
26
A019
3716
3695
3653
21
63
A020
3727
3716
3698
11
29
A021
3727
3720
3694
7
33
A022
3717
3700
3667
17
50
A023
3719
3706
3663
13
56
A024
3717
3702
3661
15
56
A025
3731
3727
3716
4
15
A026
3717
3705
3673
12
44
A027
3714
3698
3667
16
47
A028
3713
3696
3651
17
62
A029
3712
3691
3647
21
65
A030
3716
3695
3635
21
81
A031
3715
3704
3687
11
28
A032
3716
3710
3675
6
41
A033
3718
3704
3671
14
47
A034
3721
3705
3674
16
47
A035
3723
3715
3699
8
24
A036
3722
3710
3681
12
41
A037
3715
3700
3669
15
46
A038
3722
3707
3686
15
36
A039
3721
3712
3698
9
23
A040
3720
3706
3664
14
56
A041
3711
3695
3638
16
73
A042
3722
3709
3687
13
35
A044
3723
3709
3683
14
40
A045
3712
3697
3647
15
65
A047
3716
3697
3668
19
48
A048
3720
3708
3682
12
38
A049
3725
3711
3690
14
35
A050
3724
3712
3685
12
39
A051
3705
3688
3634
17
71
A052
3725
3714
3687
11
38
A053
3724
3717
3696
7
28
A054
3715
3701
3679
14
36
A055
3718
3684
3627
34
91
A056
3710
3689
3624
21
86
A057
3709
3701
3683
8
26
A058
3725
3710
3669
15
56
A059
3722
3712
3696
10
26
A060
3719
3712
3698
7
21
A061
3720
3708
3680
12
40
A062
3719
3701
3651
18
68
A063
3728
3715
3697
13
31
A064
3718
3707
3685
11
33
A065
3721
3704
3680
17
41
A066
3727
3717
3707
10
20
A067
3708
3689
3641
19
67
A068
3726
3712
3686
14
40
A069
3719
3715
3695
4
24
A070
3716
3705
3671
11
45
A071
3714
3696
3660
18
54
A072
3713
3693
3646
20
67
A073
3707
3686
3639
21
68
A074
3699
3684
3665
15
34
A075
3734
3730
3726
4
8
A076
3719
3704
3665
15
54
A077
3718
3694
3634
24
84
A078
3723
3707
3684
16
39
A080
3729
3712
3637
17
92
A081
3710
3694
3626
16
84
A082
3716
3703
3654
13
62
A083
3720
3710
3686
10
34
A084
3731
3721
3667
10
64
A085
3727
3704
3675
23
52
A086
3717
3699
3650
18
67
A087
3715
3694
3654
21
61
A088
3704
3681
3630
23
74
A089
3723
3714
3687
9
36
A090
3714
3685
3588
29
126
A091
3724
3710
3659
14
65
A092
3696
3657
3582
39
114
A093
3730
3716
3693
14
37
A094
3720
3708
3676
12
44
A095
3710
3689
3638
21
72
A096
3725
3717
3700
8
25
A097
3721
3713
3692
8
29
A098
3716
3696
3659
20
57
A099
3720
3712
3685
8
35
A100
3709
3685
3625
24
84
A101
3727
3715
3690
12
37
A102
3722
3708
3661
14
61
A103
3714
3693
3640
21
74
A104
3719
3705
3682
14
37
A105
3725
3706
3660
19
65
A107
3720
3707
3660
13
60
A108
3731
3723
3709
8
22
A109
3727
3711
3689
16
38
A110
3719
3693
3635
26
84
A111
3723
3701
3667
22
56
A112
3714
3695
3614
19
100
A113
3717
3702
3664
15
53
A114
3711
3687
3655
24
56
A115
3716
3697
3652
19
64
A116
3726
3717
3698
9
28
A117
3710
3688
3630
22
80
A118
3729
3721
3699
8
30
A119
3729
3716
3679
13
50
A120
3722
3713
3688
9
34
A121
3730
3722
3704
8
26
A122
3713
3688
3650
25
63
A123
3729
3721
3704
8
25
A124
3721
3712
3696
9
25
A125
3683
3668
3600
15
83
A126
3736
3723
3714
13
22
A127
3715
3703
3640
12
75
A128
3723
3714
3682
9
41
A129
3728
3715
3677
13
51
A130
3715
3700
3656
15
59
A131
3723
3711
3690
12
33
A132
3720
3700
3665
20
55
A133
3728
3706
3673
22
55
A134
3725
3696
3667
29
58
A135
3717
3703
3676
14
41
A136
3725
3712
3659
13
66
A137
3712
3691
3662
21
50
A138
3714
3691
3641
23
73
A139
3717
3700
3642
17
75
A140
3710
3690
3642
20
68
A141
3715
3698
3661
17
54
A142
3729
3719
3706
10
23
A143
3726
3709
3693
17
33
A144
3709
3693
3641
16
68
A145
3704
3688
3639
16
65
A146
3718
3706
3664
12
54
A147
3713
3698
3661
15
52
A148
3714
3701
3646
13
68
A149
3711
3692
3653
19
58
A150
3701
3678
3608
23
93
A151
3701
3668
3587
33
114
A152
3717
3706
3683
11
34
A153
3691
3669
3596
22
95
A154
3706
3690
3645
16
61
A155
3724
3703
3667
21
57
A156
3717
3711
3688
6
29
A157
3717
3702
3678
15
39
A158
3723
3715
3689
8
34
A159
3714
3696
3652
18
62
A160
3717
3690
3655
27
62
A161
3720
3713
3676
7
44
A162
3722
3706
3653
16
69
A163
3725
3715
3683
10
42
A164
3721
3712
3685
9
36
A165
3707
3693
3636
14
71
A166
3704
3683
3631
21
73
A167
3718
3712
3690
6
28
A168
3722
3700
3669
22
53
A169
3705
3694
3624
11
81
A170
3717
3704
3680
13
37
A171
3721
3699
3666
22
55
A172
3726
3719
3691
7
35
A173
3718
3708
3680
10
38
A174
3707
3692
3648
15
59
A175
3689
3671
3642
18
47
A176
3724
3711
3671
13
53
A177
3721
3710
3689
11
32
A178
3716
3700
3655
16
61
A179
3717
3707
3672
10
45
A180
3718
3706
3686
12
32
A181
3722
3703
3676
19
46
A182
3716
3706
3667
10
49
A183
3711
3703
3689
8
22
A184
3717
3705
3661
12
56
A185
3711
3694
3639
17
72
A186
3721
3675
3620
46
101
A187
3715
3704
3668
11
47
A188
3717
3703
3672
14
45
A189
3709
3689
3658
20
51
A190
3718
3709
3688
9
30
A191
3725
3717
3696
8
29
A192
3722
3714
3691
8
31
A193
3727
3718
3685
9
42
A194
3720
3710
3688
10
32
A195
3691
3667
3589
24
102
A196
3718
3707
3673
11
45
A197
3706
3692
3637
14
69
A198
3717
3707
3692
10
25
A199
3720
3705
3684
15
36
A200
3718
3709
3686
9
32
A201
3725
3713
3681
12
44
A202
3723
3713
3694
10
29
A203
3715
3704
3670
11
45
A204
3723
3713
3697
10
26
A205
3717
3706
3674
11
43
A207
3710
3702
3668
8
42
A208
3722
3708
3680
14
42
A209
3725
3709
3682
16
43
A210
3724
3714
3688
10
36
A211
3712
3694
3637
18
75
A212
3727
3711
3689
16
38
A213
3724
3705
3652
19
72
A214
3727
3715
3687
12
40
A215
3715
3703
3668
12
47
A216
3722
3707
3667
15
55
A217
3716
3695
3630
21
86
A218
3699
3665
3583
34
116
A219
3727
3716
3699
11
28
A220
3717
3704
3674
13
43
A222
3713
3704
3684
9
29
A223
3724
3715
3695
9
29
A224
3718
3703
3676
15
42
A225
3721
3707
3683
14
38
[0000]
TABLE 3
(Part B)
ID
FTR od
Time@T2S
Time@Map
Time@TEot
ΔT2SMap
ΔT2STEot
FTR time
FTR od
A001
0.218
2211
2366
2921
155
710
0.218
0.218
A002
0.333
2279
2464
2834
185
555
0.333
0.333
A003
0.375
2329
2523
2846
194
517
0.375
0.375
A004
0.267
1975
2107
2470
132
495
0.267
0.267
A005
0.444
2166
2387
2663
221
497
0.444
0.444
A007
0.259
1838
1931
2197
93
359
0.259
0.259
A008
0.309
2160
2369
2837
209
677
0.309
0.309
A009
0.367
2391
2598
2956
207
565
0.367
0.367
A010
0.500
1716
1925
2134
209
418
0.500
0.500
A011
0.326
1788
1935
2240
147
452
0.326
0.326
A012
0.364
2233
2428
2769
195
536
0.364
0.364
A013
0.338
2409
2667
3173
258
764
0.338
0.338
A014
0.391
1701
1836
2046
135
345
0.391
0.391
A015
0.400
1715
1877
2120
162
405
0.400
0.400
A016
0.159
2233
2336
2880
103
647
0.159
0.159
A017
0.333
1728
1882
2190
154
462
0.333
0.333
A018
0.538
1862
2175
2443
313
581
0.538
0.538
A019
0.333
1756
1927
2269
171
513
0.333
0.333
A020
0.379
2535
2761
3131
226
596
0.379
0.379
A021
0.212
2151
2283
2773
132
622
0.212
0.212
A022
0.340
1900
2089
2456
189
556
0.340
0.340
A023
0.232
2251
2384
2824
133
573
0.232
0.232
A024
0.268
2522
2676
3097
154
575
0.268
0.268
A025
0.267
1708
1775
1959
67
251
0.267
0.267
A026
0.273
1611
1730
2047
119
436
0.273
0.273
A027
0.340
1537
1689
1984
152
447
0.340
0.340
A028
0.274
1780
1927
2316
147
536
0.274
0.274
A029
0.323
1839
2023
2409
184
570
0.323
0.323
A030
0.259
2051
2245
2799
194
748
0.259
0.259
A031
0.393
2107
2321
2652
214
545
0.393
0.393
A032
0.146
2584
2678
3226
94
642
0.146
0.146
A033
0.298
2251
2426
2839
175
588
0.298
0.298
A034
0.340
1909
2107
2491
198
582
0.340
0.340
A035
0.333
3037
3305
3841
268
804
0.333
0.333
A036
0.293
2211
2417
2915
206
704
0.293
0.293
A037
0.326
2173
2335
2670
162
497
0.326
0.326
A038
0.417
1543
1713
1951
170
408
0.417
0.417
A039
0.391
1572
1721
1953
149
381
0.391
0.391
A040
0.250
1959
2119
2599
160
640
0.250
0.250
A041
0.219
1993
2144
2682
151
689
0.219
0.219
A042
0.371
2660
2929
3384
269
724
0.371
0.371
A044
0.350
2657
2858
3231
201
574
0.350
0.350
A045
0.231
2175
2325
2825
150
650
0.231
0.231
A047
0.396
2197
2458
2856
261
659
0.396
0.396
A048
0.316
2535
2783
3320
248
785
0.316
0.316
A049
0.400
2004
2256
2634
252
630
0.400
0.400
A050
0.308
2193
2403
2876
210
683
0.308
0.308
A051
0.239
1745
1867
2255
122
510
0.239
0.239
A052
0.289
2073
2247
2674
174
601
0.289
0.289
A053
0.250
2239
2353
2695
114
456
0.250
0.250
A054
0.389
1816
2005
2302
189
486
0.389
0.389
A055
0.374
3127
3668
4575
541
1448
0.374
0.374
A056
0.244
2538
2728
3316
190
778
0.244
0.244
A057
0.308
2125
2263
2574
138
449
0.308
0.308
A058
0.268
4120
4529
5647
409
1527
0.268
0.268
A059
0.385
2164
2358
2668
194
504
0.385
0.385
A060
0.333
2325
2494
2832
169
507
0.333
0.333
A061
0.300
2006
2205
2669
199
663
0.300
0.300
A062
0.265
3718
4058
5002
340
1284
0.265
0.265
A063
0.419
2231
2584
3073
353
842
0.419
0.419
A064
0.333
1926
2076
2376
150
450
0.333
0.333
A065
0.415
2225
2494
2874
269
649
0.415
0.415
A066
0.500
1761
1968
2175
207
414
0.500
0.500
A067
0.284
1701
1852
2233
151
532
0.284
0.284
A068
0.350
1979
2215
2653
236
674
0.350
0.350
A069
0.167
1935
1998
2313
63
378
0.167
0.167
A070
0.244
1939
2063
2446
124
507
0.244
0.244
A071
0.333
1762
1950
2326
188
564
0.333
0.333
A072
0.299
1723
1912
2356
189
633
0.299
0.299
A073
0.309
1614
1774
2132
160
518
0.309
0.309
A074
0.441
1698
1884
2120
186
422
0.441
0.441
A075
0.500
1489
1620
1751
131
262
0.500
0.500
A076
0.278
1529
1684
2087
155
558
0.278
0.278
A077
0.286
2845
3154
3927
309
1082
0.286
0.286
A078
0.410
1867
2081
2389
214
522
0.410
0.410
A080
0.185
3548
3924
5583
376
2035
0.185
0.185
A081
0.190
2698
2853
3512
155
814
0.190
0.190
A082
0.210
1625
1744
2193
119
568
0.210
0.210
A083
0.294
1583
1692
1954
109
371
0.294
0.294
A084
0.156
3394
3647
5013
253
1619
0.156
0.156
A085
0.442
2416
2867
3436
451
1020
0.442
0.442
A086
0.269
2111
2293
2788
182
677
0.269
0.269
A087
0.344
1740
1924
2274
184
534
0.344
0.344
A088
0.311
1715
1881
2249
166
534
0.311
0.311
A089
0.250
1876
1981
2296
105
420
0.250
0.250
A090
0.230
3411
3775
4993
364
1582
0.230
0.230
A091
0.215
3897
4201
5308
304
1411
0.215
0.215
A092
0.342
1906
2151
2622
245
716
0.342
0.342
A093
0.378
2821
3197
3815
376
994
0.378
0.378
A094
0.273
2447
2600
3008
153
561
0.273
0.273
A095
0.292
1573
1726
2098
153
525
0.292
0.292
A096
0.320
1784
1913
2187
129
403
0.320
0.320
A097
0.276
1374
1479
1755
105
381
0.276
0.276
A098
0.351
1480
1655
1979
175
499
0.351
0.351
A099
0.229
1679
1770
2077
91
398
0.229
0.229
A100
0.286
1538
1705
2123
167
585
0.286
0.286
A101
0.324
2137
2344
2775
207
638
0.324
0.324
A102
0.230
2473
2657
3275
184
802
0.230
0.230
A103
0.284
1868
2069
2576
201
708
0.284
0.284
A104
0.378
2344
2732
3369
388
1025
0.378
0.378
A105
0.292
2427
2750
3532
323
1105
0.292
0.292
A107
0.217
2140
2305
2902
165
762
0.217
0.217
A108
0.364
1876
2034
2311
158
435
0.364
0.364
A109
0.421
1900
2206
2627
306
727
0.421
0.421
A110
0.310
2621
3048
4001
427
1380
0.310
0.310
A111
0.393
2064
2409
2942
345
878
0.393
0.393
A112
0.190
2000
2165
2868
165
868
0.190
0.190
A113
0.283
1699
1872
2310
173
611
0.283
0.283
A114
0.429
1838
2101
2452
263
614
0.429
0.429
A115
0.297
2091
2281
2731
190
640
0.297
0.297
A116
0.321
1571
1707
1994
136
423
0.321
0.321
A117
0.275
1691
1874
2356
183
665
0.275
0.275
A118
0.267
1835
1969
2338
134
503
0.267
0.267
A119
0.260
2118
2320
2895
202
777
0.260
0.260
A120
0.265
1833
1960
2313
127
480
0.265
0.265
A121
0.308
1825
1992
2368
167
543
0.308
0.308
A122
0.397
1674
1931
2322
257
648
0.397
0.397
A123
0.320
1669
1824
2153
155
484
0.320
0.320
A124
0.360
1627
1766
2013
139
386
0.360
0.360
A125
0.181
1485
1591
2072
106
587
0.181
0.181
A126
0.591
2476
2969
3310
493
834
0.591
0.591
A127
0.160
1935
2040
2591
105
656
0.160
0.160
A128
0.220
2485
2627
3132
142
647
0.220
0.220
A129
0.255
3083
3385
4268
302
1185
0.255
0.255
A130
0.254
3137
3330
3896
193
759
0.254
0.254
A131
0.364
1729
1930
2282
201
553
0.364
0.364
A132
0.364
2288
2601
3149
313
861
0.364
0.364
A133
0.400
2132
2531
3130
399
998
0.400
0.400
A134
0.500
3654
4285
4916
631
1262
0.500
0.500
A135
0.341
1511
1652
1924
141
413
0.341
0.341
A136
0.197
2697
2874
3596
177
899
0.197
0.197
A137
0.420
1797
1980
2233
183
436
0.420
0.420
A138
0.315
1931
2137
2585
206
654
0.315
0.315
A139
0.227
1905
2069
2629
164
724
0.227
0.227
A140
0.294
1483
1623
1959
140
476
0.294
0.294
A141
0.315
1872
2044
2418
172
546
0.315
0.315
A142
0.435
2390
2573
2811
183
421
0.435
0.435
A143
0.515
2047
2421
2773
374
726
0.515
0.515
A144
0.235
2017
2143
2553
126
536
0.235
0.235
A145
0.246
1492
1602
1939
110
447
0.246
0.246
A146
0.222
1899
2068
2660
169
761
0.222
0.222
A147
0.288
1608
1738
2059
130
451
0.288
0.288
A148
0.191
1967
2090
2610
123
643
0.191
0.191
A149
0.328
1581
1718
1999
137
418
0.328
0.328
A150
0.247
1558
1690
2092
132
534
0.247
0.247
A151
0.289
2177
2402
2954
225
777
0.289
0.289
A152
0.324
1876
2006
2278
130
402
0.324
0.324
A153
0.232
1713
1859
2343
146
630
0.232
0.232
A154
0.262
1887
2053
2520
166
633
0.262
0.262
A155
0.368
2906
3327
4049
421
1143
0.368
0.368
A156
0.207
2191
2291
2674
100
483
0.207
0.207
A157
0.385
1886
2065
2351
179
465
0.385
0.385
A158
0.235
2424
2551
2964
127
540
0.235
0.235
A159
0.290
2678
2973
3694
295
1016
0.290
0.290
A160
0.435
2160
2489
2915
329
755
0.435
0.435
A161
0.159
1674
1762
2227
88
553
0.159
0.159
A162
0.232
3480
3835
5011
355
1531
0.232
0.232
A163
0.238
2505
2697
3311
192
806
0.238
0.238
A164
0.250
2535
2718
3267
183
732
0.250
0.250
A165
0.197
2072
2189
2665
117
593
0.197
0.197
A166
0.288
1883
2051
2467
168
584
0.288
0.288
A167
0.214
2228
2321
2662
93
434
0.214
0.214
A168
0.415
2366
2847
3525
481
1159
0.415
0.415
A169
0.136
2543
2661
3412
118
869
0.136
0.136
A170
0.351
1456
1589
1835
133
379
0.351
0.351
A171
0.400
2463
2761
3208
298
745
0.400
0.400
A172
0.200
1944
2070
2574
126
630
0.200
0.200
A173
0.263
1505
1600
1866
95
361
0.263
0.263
A174
0.254
1687
1816
2194
129
507
0.254
0.254
A175
0.383
1681
1821
2047
140
366
0.383
0.383
A176
0.245
2344
2544
3159
200
815
0.245
0.245
A177
0.344
1596
1733
1995
137
399
0.344
0.344
A178
0.262
2019
2183
2644
164
625
0.262
0.262
A179
0.222
2056
2181
2619
125
563
0.222
0.222
A180
0.375
1891
2096
2438
205
547
0.375
0.375
A181
0.413
2575
2959
3505
384
930
0.413
0.413
A182
0.204
1828
1930
2328
102
500
0.204
0.204
A183
0.364
1523
1644
1856
121
333
0.364
0.364
A184
0.214
2049
2187
2693
138
644
0.214
0.214
A185
0.236
2417
2606
3217
189
800
0.236
0.236
A186
0.455
2223
2909
3729
686
1506
0.455
0.455
A187
0.234
1654
1755
2086
101
432
0.234
0.234
A188
0.311
2229
2460
2972
231
743
0.311
0.311
A189
0.392
2320
2588
3003
268
683
0.392
0.392
A190
0.300
2473
2670
3130
197
657
0.300
0.300
A191
0.276
1782
1907
2235
125
453
0.276
0.276
A192
0.258
2127
2255
2623
128
496
0.258
0.258
A193
0.214
1788
1920
2404
132
616
0.214
0.214
A194
0.313
1930
2107
2496
177
566
0.313
0.313
A195
0.235
1581
1710
2129
129
548
0.235
0.235
A196
0.244
1821
1958
2381
137
560
0.244
0.244
A197
0.203
1743
1835
2196
92
453
0.203
0.203
A198
0.400
1696
1912
2236
216
540
0.400
0.400
A199
0.417
1498
1665
1899
167
401
0.417
0.417
A200
0.281
1441
1554
1843
113
402
0.281
0.281
A201
0.273
2036
2205
2656
169
620
0.273
0.273
A202
0.345
1898
2080
2426
182
528
0.345
0.345
A203
0.244
1768
1880
2226
112
458
0.244
0.244
A204
0.385
1642
1820
2105
178
463
0.385
0.385
A205
0.256
1851
1983
2367
132
516
0.256
0.256
A207
0.190
2173
2299
2835
126
662
0.190
0.190
A208
0.333
2277
2531
3039
254
762
0.333
0.333
A209
0.372
1721
1937
2302
216
581
0.372
0.372
A210
0.278
1907
2066
2479
159
572
0.278
0.278
A211
0.240
2153
2306
2791
153
638
0.240
0.240
A212
0.421
2143
2458
2891
315
748
0.421
0.421
A213
0.264
2057
2332
3099
275
1042
0.264
0.264
A214
0.300
2116
2363
2939
247
823
0.300
0.300
A215
0.255
1982
2118
2515
136
533
0.255
0.255
A216
0.273
2799
3061
3760
262
961
0.273
0.273
A217
0.244
2021
2237
2906
216
885
0.244
0.244
A218
0.293
2319
2571
3179
252
860
0.293
0.293
A219
0.393
2098
2309
2635
211
537
0.393
0.393
A220
0.302
1803
1943
2266
140
463
0.302
0.302
A222
0.310
1705
1876
2256
171
551
0.310
0.310
A223
0.310
1593
1732
2041
139
448
0.310
0.310
A224
0.357
1649
1811
2103
162
454
0.357
0.357
A225
0.368
1655
1824
2114
169
459
0.368
0.368
[0116] Comparative Results of nATFt's and nATFz's
[0117] Results between patients in two different geographic locations (i.e., two different hospitals) were compared for correlation with each other. This comparison is expressed in Table 4 below, and includes a comparison of INR values calculated by the WHO method for each respective location, with GInr representing one location for these traditionally WHO determined values, and MInr representing values based on data obtained at the other location. The values identified as ATFz and ATFt, such as, GATFt and MATFt, and GATFz and MATFz, represent anticoagulant therapy factors derived from the expressions (1) through (9) above.
[0118] The ATFa represents an anticoagulation therapy factor derived from our method and apparatus for the expression ATFa=XR (2-nFTR) wherein a maximum acceleration point is obtained, and nFTR=IUX/IUT, where IUX is the change in optical density from a time prior to the MAP time (t <MAP which is t MAP minus some time from MAP) to the optical density at a time after the MAP time (t >MAP which is t MAP plus some time from MAP); and wherein IUT=the change in optical density at the time t 1 to the optical density measured at time t EOT , where time t EOT is the end of the test (EOT). The (IUX) represents the fibrinogen (FBG) for MAP (−a number of seconds) to MAP (+a number of seconds) (that is the fibrinogen (FBG) converted from t <MAP to t >MAP on FIG. 2 ) The (IUT) represents fibrinogen converted from c 1 to c EOT (that is the fibrinogen converted from t 1 to t EOT , see FIG. 2 ). The XR for the ATFa expression is XR=TX/MNTX, which is the ratio of time to map (TX) by the mean normal time to map of 20 presumed “normal” patients.
[0000]
TABLE 4
COMPARATIVE RESULTS FOR ATFt and ATFz
Std.
Comparison
n
r
m
b
Error
Ng
Lassen
GInr vs.
129
0.996
0.891
0.148
0.082
6/129 =
delta <= 0.4 5@96.1%
GATFa
4.7%
delta <= 0.7 2@98.4%
mismatches
GInr vs.
129
0.975
1.014
−0.016
0.215
15/129 =
delta <= 0.4 9@93%
GATFz
11.6%
delta <= 0.7 3@97.7%
mismatches
GInr vs.
129
0.971
0.895
0.332
0.232
26/129 =
delta <= 0.4 18@86.0%
GATFt
20.2%
delta <= 0.7 2@98.4%
mismatches
MInr vs.
129
0.996
0.943
0.082
0.094
18/129 =
delta <= 0.4 15@88.4%
MATFa
14.0%
delta <= 0.7 5@96.1%
mismatches
MInr vs.
129
0.985
0.993
−0.058
0.177
2/129 =
delta <= 0.4 0@100%
MATFz
1.6%
delta <= 0.7 0@100%
mismatches
MInr vs.
129
0.981
0.851
0.420
0.200
8/129 =
delta <= 0.4 6@95.3
MATFt
6.2%
delta <= 0.7 2@98.4%
mismatches
[0119] A comparison of combined location data is shown in Table 5, below. The sample size was 217.
[0000]
TABLE 5
STATISTICAL SUMMARY OF MHTL DATA
Com-
Std.
parison
n
r
m
b
Error
Ng
Lassen
Inr vs
217
0.984
1.006
0.011
0.215
30/217 =
delta <= 0.4
ATFa
13.8%
16@92.6%
mismatches
delta <= 0.7
1@99.5%
Inr vs.
217
0.984
1.002
0.120
0.214
26/217 =
delta <= 0.4
ATFz
12.0%
18@91.7%
mismatched
delta <= 0.7
3@98.6%
Inr vs.
217
0.984
0.900
0.482
1.218
45/217 =
delta <= 0.4
ATFt
20.7%
43@80.2%
mismatches
delta <= 0.7
6@97.2%
[0120] Comparative results were also calculated for the ATFt which includes the lag phase fibrinogen, in accordance with the IULz, using the expression (5.1) for the TEOT value. Table 6 below provides the values for the ATFz, ATFt, and the ATFt2 (which is obtained from expression 5.1 using the IULz).
[0000]
TABLE 6
ID
INR
INRz
ATFt
ATFt2
A001
3.1
2.9
2.4
2.6
A002
3.3
2.9
2.4
2.6
A003
3.3
2.9
2.4
2.6
A004
2.1
2.3
1.8
2.0
A005
2.9
2.6
2.1
2.3
A007
2.1
2.0
1.5
1.6
A008
2.8
2.8
2.3
2.5
A009
3.4
3.1
2.6
2.8
A010
1.9
1.8
1.3
1.5
A011
2.1
1.9
1.5
1.6
A012
3.2
2.8
2.3
2.5
A013
3.5
3.3
2.8
3.0
A014
1.8
1.7
1.3
1.4
A015
1.9
1.8
1.3
1.5
A016
3.2
2.9
2.4
2.6
A017
1.8
1.9
1.4
1.6
A018
2.2
2.1
1.7
1.8
A019
1.8
1.9
1.5
1.6
A020
3.5
3.4
2.9
3.2
A021
2.8
2.7
2.2
2.4
A022
2.2
2.2
1.7
1.9
A023
3.2
2.9
2.3
2.5
A024
3.7
3.5
2.9
3.1
A025
1.8
1.7
1.2
1.4
A026
1.6
1.6
1.2
1.4
A027
1.5
1.5
1.1
1.3
A028
1.9
2.0
1.5
1.7
A029
2.1
2.1
1.6
1.8
A030
2.6
2.6
2.1
2.3
A031
2.7
2.5
2.1
2.3
A032
4.1
3.8
3.1
3.3
A033
2.9
2.9
2.4
2.6
A034
2.2
2.2
1.7
1.9
A035
4.9
4.7
4.3
4.7
A036
3.2
2.9
2.4
2.6
A037
2.5
2.7
2.1
2.4
A038
1.6
1.6
1.1
1.2
A039
1.4
1.6
1.1
1.3
A040
2.4
2.4
1.9
2.1
A041
2.3
2.4
2.0
2.2
A042
4.1
3.8
3.3
3.6
A044
4.2
3.7
3.2
3.4
A045
2.7
2.8
2.3
2.5
A047
2.8
2.8
2.3
2.5
A048
3.9
3.6
3.1
3.3
A049
2.6
2.4
1.9
2.1
A050
2.8
2.8
2.3
2.5
A051
1.9
1.9
1.4
1.6
A052
2.8
2.6
2.0
2.2
A053
3.0
2.8
2.2
2.4
A054
2.1
2.0
1.5
1.7
A055
5.6
5.4
5.3
5.6
A056
3.6
3.7
3.1
3.4
A057
2.8
2.6
2.0
2.2
A058
8.5
8.7
8.6
9.1
A059
2.9
2.6
2.1
2.3
A060
3.5
3.0
2.4
2.6
A061
2.4
2.5
2.0
2.1
A062
7.0
7.2
6.8
7.3
A063
3.0
3.0
2.5
2.7
A064
2.2
2.2
1.7
1.9
A065
2.6
2.8
2.4
2.6
A066
2.0
1.9
1.4
1.6
A067
1.8
1.8
1.4
1.6
A068
2.6
2.4
1.9
2.1
A069
2.4
2.2
1.6
1.8
A070
2.4
2.3
1.7
1.9
A071
1.9
2.0
1.5
1.7
A072
1.8
1.9
1.5
1.6
A073
1.5
1.7
1.3
1.4
A074
1.7
1.8
1.3
1.5
A075
1.6
1.4
1.0
1.1
A076
1.4
1.6
1.2
1.3
A077
4.5
4.6
4.1
4.4
A078
2.2
2.1
1.6
1.8
A080
7.3
7.4
7.3
7.6
A081
3.8
4.2
3.5
3.8
A082
1.6
1.7
1.3
1.5
A083
1.6
1.6
1.1
1.3
A084
6.7
6.7
6.3
6.6
A085
3.3
3.4
3.1
3.3
A086
2.8
2.7
2.2
2.4
A087
1.8
1.9
1.5
1.6
A088
1.7
1.9
1.4
1.6
A089
2.3
2.1
1.6
1.7
A090
6.3
6.6
6.3
6.7
A091
7.6
8.1
7.6
8.1
A092
1.9
2.3
1.8
2.0
A093
4.9
4.3
4.0
4.2
A094
3.2
3.3
2.7
2.9
A095
1.5
1.6
1.2
1.4
A096
2.3
1.9
1.4
1.6
A097
1.3
1.3
0.9
1.0
A098
1.4
1.5
1.1
1.2
A099
1.8
1.7
1.3
1.4
A100
1.4
1.6
1.2
1.3
A101
2.7
2.7
2.2
2.4
A102
3.8
3.6
3.0
3.2
A103
2.0
2.2
1.8
1.9
A104
3.2
3.3
2.9
3.2
A105
3.7
3.6
3.2
3.4
A107
2.9
2.8
2.3
2.5
A108
2.1
2.1
1.6
1.8
A109
2.2
2.3
1.8
2.0
A110
3.9
4.2
3.9
4.1
A111
2.5
2.7
2.2
2.4
A112
2.5
2.5
2.1
2.3
A113
1.9
1.9
1.4
1.6
A114
2.1
2.1
1.7
1.8
A115
2.4
2.6
2.1
2.3
A116
1.7
1.6
1.2
1.3
A117
1.6
1.9
1.5
1.6
A118
2.1
2.1
1.6
1.7
A119
3.0
2.7
2.3
2.4
A120
2.1
2.0
1.6
1.7
A121
2.2
2.1
1.6
1.7
A122
1.7
1.9
1.4
1.6
A123
1.8
1.8
1.3
1.5
A124
1.8
1.7
1.2
1.3
A125
1.4
1.4
1.1
1.3
A126
3.7
3.2
3.0
3.3
A127
2.4
2.3
1.8
2.0
A128
3.8
3.5
2.9
3.1
A129
5.3
5.3
4.8
5.3
A130
4.7
5.2
4.5
4.9
A131
1.7
1.9
1.5
1.6
A132
2.8
3.1
2.7
2.9
A133
2.6
2.9
2.5
2.7
A134
6.6
6.0
6.6
7.1
A135
1.5
1.5
1.1
1.2
A136
4.3
4.2
3.6
3.8
A137
1.9
1.9
1.5
1.6
A138
2.0
2.3
1.8
2.0
A139
2.1
2.3
1.8
2.0
A140
1.3
1.5
1.1
1.2
A141
2.2
2.1
1.7
1.8
A142
3.4
2.9
2.5
2.7
A143
2.5
2.5
2.1
2.3
A144
2.5
2.4
1.9
2.1
A145
1.4
1.4
1.1
1.2
A146
2.3
2.3
1.9
2.0
A147
1.7
1.6
1.2
1.4
A148
2.3
2.4
1.9
2.1
A149
1.6
1.6
1.2
1.3
A150
1.6
1.6
1.2
1.3
A151
2.8
2.9
2.4
2.6
A152
2.2
2.1
1.6
1.7
A153
1.8
1.9
1.5
1.6
A154
2.2
2.2
1.7
1.9
A155
4.8
4.6
4.3
4.7
A156
2.9
2.8
2.2
2.4
A157
2.1
2.1
1.6
1.8
A158
3.6
3.3
2.6
2.8
A159
3.9
4.1
3.6
3.9
A160
2.7
2.8
2.3
2.5
A161
1.7
1.8
1.4
1.5
A162
6.6
6.8
6.4
6.9
A163
3.9
3.6
3.1
3.3
A164
4.0
3.6
3.0
3.3
A165
2.7
2.6
2.0
2.2
A166
2.2
2.2
1.7
1.9
A167
2.9
2.8
2.2
2.4
A168
3.6
3.5
3.1
3.3
A169
4.1
3.8
3.2
3.4
A170
1.4
1.4
1.0
1.1
A171
3.4
3.3
2.9
3.1
A172
2.5
2.3
1.8
2.0
A173
1.6
1.4
1.0
1.1
A174
1.8
1.8
1.4
1.5
A175
1.8
1.7
1.3
1.4
A176
3.4
3.3
2.7
2.9
A177
1.7
1.6
1.2
1.3
A178
2.3
2.5
2.0
2.1
A179
2.6
2.5
2.0
2.2
A180
2.3
2.2
1.7
1.9
A181
3.5
3.7
3.3
3.6
A182
2.1
2.0
1.6
1.7
A183
1.5
1.5
1.0
1.2
A184
2.6
2.5
2.0
2.2
A185
3.3
3.4
2.9
3.1
A186
3.1
3.5
3.1
3.3
A187
1.8
1.7
1.3
1.4
A188
3.1
2.9
2.4
2.6
A189
3.0
3.0
2.6
2.8
A190
3.6
3.4
2.8
3.1
A191
2.0
1.9
1.5
1.6
A192
2.7
2.6
2.1
2.3
A193
2.1
2.0
1.6
1.7
A194
2.2
2.3
1.8
2.0
A195
1.4
1.6
1.2
1.4
A196
2.0
2.1
1.6
1.8
A197
1.8
1.9
1.4
1.5
A198
2.0
1.9
1.4
1.5
A199
1.5
1.5
1.0
1.2
A200
1.4
1.4
1.0
1.1
A201
2.6
2.5
2.0
2.2
A202
2.5
2.2
1.7
1.9
A203
2.0
1.9
1.4
1.6
A204
1.8
1.7
1.3
1.4
A205
1.9
2.1
1.6
1.8
A207
2.7
2.8
2.3
2.5
A208
3.0
3.0
2.5
2.8
A209
1.9
1.9
1.5
1.6
A210
2.4
2.2
1.7
1.9
A211
2.9
2.7
2.2
2.4
A212
2.8
2.7
2.3
2.5
A213
2.7
2.8
2.3
2.5
A214
2.8
2.8
2.3
2.5
A215
2.5
2.3
1.8
2.0
A216
4.1
4.4
3.9
4.2
A217
2.3
2.6
2.2
2.3
A218
2.9
3.2
2.7
3.0
A219
2.7
2.5
2.0
2.2
A220
2.0
2.0
1.5
1.7
A222
2.0
1.9
1.4
1.6
A223
1.7
1.6
1.2
1.4
A224
1.6
1.7
1.3
1.4
A225
1.8
1.7
1.3
1.4
[0121] Table 7 represents a comparison of the data from Table 6.
[0000]
TABLE 7
“r”
“m”
“b”
StdErr
StdDev
INR
INRz
0.988
0.988
0.059
0.190
1.201
vs
ATFt
0.984
0.966
0.568
0.215
1.238
ATFt2
0.983
0.913
0.504
0.219
1.257
ATFt
ATFt2
1.000
0.946
−0.068
0.022
1.264
vs
[0122] Table 8 provides comparative data for the anticoagulant therapy factors, similar to Table 2, but using the ATFt2 method from expressions (4) and (5.1) for corresponding GINRt2 and MINRt2 values.
[0000]
TABLE 8
ID
AINR
GINR
GINRa
GINRz
GINRt2
MINR
MINRa
MINRz
MINRt2
U0800
2.0
2.0
2.0
2.0
1.7
2.1
2.1
2.2
2.1
U7440
2.6
3.0
3.0
2.9
2.9
3.0
3.0
2.8
3.4
U7443
2.0
2.0
2.0
2.0
1.8
2.1
2.2
2.1
1.8
U7458
1.4
1.4
1.4
1.4
1.2
1.4
1.4
1.3
1.3
U7465
9.7
7.4
8.1
6.6
7.9
7.1
7.5
8.1
7.8
U7469
1.1
1.1
1.1
1.1
0.9
1.2
1.1
1.1
1.0
U7470
3.2
3.4
3.6
3.4
3.2
3.6
3.7
3.8
3.8
U8080
3.1
3.6
3.6
3.3
3.6
3.3
3.3
3.5
3.4
U8087
1.9
1.9
1.9
1.8
1.6
1.9
1.9
1.9
1.7
U8092
1.7
1.7
1.8
1.7
1.6
1.9
1.9
1.9
1.6
U3050
2.7
2.8
3.1
2.6
2.2
2.3
2.3
2.3
2.0
U3077
1.3
1.4
1.4
1.4
1.1
1.3
1.3
1.3
1.2
U3083
1.6
1.6
1.6
1.6
1.3
1.6
1.7
1.6
1.4
U8210
2.6
2.9
3.0
2.8
2.7
2.7
2.8
2.8
2.6
U8221
3.2
3.7
4.0
3.7
3.4
3.5
3.5
3.3
3.6
U3408
1.1
1.2
1.2
1.2
0.9
1.1
1.0
1.0
0.9
U3453
1.1
1.2
1.2
1.2
1.0
1.2
1.2
1.2
1.0
U3457
2.2
2.3
2.4
2.2
1.9
2.1
2.3
2.2
1.8
U3395
2.7
3.2
3.5
3.2
2.7
2.8
2.9
2.5
2.3
U3398
1.5
1.7
1.8
1.8
1.5
1.6
1.6
1.6
1.5
U3456
1.1
1.0
1.0
1.0
0.8
1.0
1.0
1.0
0.9
U3459
2.9
2.6
2.8
2.6
2.2
2.4
2.5
2.5
2.0
U0415
0.9
0.9
0.9
0.9
0.8
0.9
1.0
1.0
0.8
U0432
1.8
1.5
1.5
1.5
1.3
1.4
1.4
1.4
1.3
U0436
2.4
2.4
2.6
2.3
2.1
2.4
2.4
2.4
2.2
U0438
3.9
3.7
4.2
3.7
3.2
3.8
4.2
3.9
3.6
U0439
2.3
2.2
2.3
2.1
1.8
2.3
2.3
2.2
2.0
U0440
5.8
4.8
5.4
5.2
4.4
4.6
4.8
4.3
5.2
U0441
4.5
4.9
5.6
6.0
5.0
4.4
4.7
4.7
5.4
U0442
1.8
1.7
1.8
1.7
1.5
1.8
1.8
1.8
1.6
U3724
2.7
2.4
2.5
2.4
2.0
2.6
2.7
2.6
2.3
U0849
2.4
2.3
2.4
2.1
1.8
2.3
2.4
2.2
2.0
U0860
1.0
1.0
1.0
1.0
0.8
1.0
1.0
1.0
0.9
U0861
2.8
2.9
3.0
2.8
2.6
3.0
3.0
2.9
3.0
U0863
1.7
1.7
1.7
1.7
1.7
1.7
1.8
1.8
1.8
U0875
2.2
2.0
2.2
2.1
1.6
2.0
2.0
2.0
1.7
U0843
1.4
1.4
1.4
1.4
1.2
1.4
1.5
1.5
1.3
U0848
1.3
1.4
1.4
1.4
1.2
1.3
1.4
1.4
1.2
U0855
1.3
1.3
1.3
1.3
1.2
1.2
1.2
1.2
1.3
U0867
3.2
2.9
3.2
2.8
2.5
3.0
3.1
3.0
2.9
U1201
1.9
1.9
2.0
1.9
1.7
1.8
1.8
1.9
1.8
U1202
1.3
1.3
1.3
1.3
1.2
1.4
1.4
1.4
1.2
U1205
1.6
1.8
1.9
1.8
1.6
1.9
1.9
1.8
1.7
U1207
1.9
1.9
2.0
1.8
1.5
1.9
1.9
1.7
1.7
U1230
1.3
1.4
1.5
1.4
1.3
1.4
1.5
1.5
1.5
U1198
2.2
2.1
2.2
2.1
1.9
2.0
2.0
2.0
2.3
U1199
2.8
3.3
3.6
3.1
2.8
3.2
3.2
2.8
3.3
U1218
3.0
2.6
2.9
2.9
2.7
2.8
3.1
3.1
3.2
U1225
2.2
2.3
2.3
2.1
1.9
2.6
2.4
2.2
2.2
U1575
1.4
1.3
1.3
1.3
1.4
1.4
1.4
1.4
1.4
U1579
1.5
1.7
1.7
1.7
1.5
1.8
1.8
1.7
1.5
U1649
0.9
0.8
0.8
0.8
0.8
0.9
0.9
0.9
0.8
U1576
2.2
2.1
2.1
2.1
2.1
2.3
2.3
2.3
2.2
U1581
1.7
1.7
1.7
1.8
1.9
1.7
1.8
1.8
1.7
U1599
2.0
1.7
1.8
1.8
2.0
2.0
2.1
2.1
2.0
U1600
3.5
3.2
3.4
3.4
3.7
3.9
4.2
3.5
3.7
U4471
1.5
1.6
1.7
1.6
1.5
1.7
1.7
1.7
1.7
U4757
2.0
2.1
2.1
2.0
1.8
2.0
2.0
2.1
2.0
U4767
2.6
2.4
2.5
2.6
2.0
2.6
2.6
2.5
2.3
U4772
2.5
2.7
2.8
2.5
2.6
2.8
2.8
2.9
2.5
U4801
1.3
1.4
1.4
1.4
1.2
1.5
1.5
1.4
1.2
U4737
2.9
2.6
2.8
2.7
2.3
2.7
2.9
2.8
2.5
U4752
1.4
1.5
1.6
1.5
1.3
1.5
1.5
1.5
1.4
U5133
0.9
0.9
0.9
0.9
0.7
1.0
1.0
1.0
0.8
U5173
1.1
1.2
1.2
1.2
1.1
1.2
1.2
1.2
1.0
U5175
1.7
1.8
1.9
1.8
1.7
1.9
1.9
1.9
1.7
U5178
2.3
2.2
2.3
2.1
1.9
2.6
2.9
2.8
2.0
U5183
2.9
2.6
2.8
2.6
2.3
3.6
3.9
3.7
3.0
U5158
5.5
5.1
5.9
5.7
5.8
6.0
6.6
7.1
7.0
U5169
2.6
2.9
3.2
3.2
3.2
3.2
3.4
3.6
3.7
U5190
2.8
2.7
2.8
2.9
2.8
3.2
3.4
3.5
3.2
U5193
3.1
3.0
3.1
3.0
2.9
3.6
3.7
3.7
3.4
U5589
1.6
1.8
1.9
1.8
1.6
1.9
2.0
1.8
1.5
U5592
1.1
1.2
1.2
1.2
1.1
1.4
1.3
1.3
1.4
U5593
1.7
1.8
1.9
1.8
1.6
1.8
1.9
1.8
1.7
U5565
2.7
3.2
3.3
3.3
3.1
3.5
3.5
3.6
3.5
U5591
2.0
2.2
2.3
2.3
2.1
2.3
2.3
2.1
2.3
U5594
2.3
2.6
2.8
2.8
2.8
2.8
2.8
3.0
3.0
U5597
3.3
3.3
3.6
3.6
3.1
4.1
4.0
4.3
4.0
U5993
1.0
0.9
0.9
0.9
0.8
1.0
1.0
1.0
0.8
U6017
1.0
0.9
1.0
1.0
0.8
0.9
0.9
0.9
0.8
U6056
1.0
1.0
1.0
1.0
0.9
1.0
1.0
1.0
0.9
U5992
1.4
1.4
1.4
1.4
1.3
1.3
1.4
1.4
1.3
U6047
2.3
2.3
2.4
2.3
2.0
2.2
2.3
2.3
2.2
U6060
1.9
2.1
2.2
2.2
2.0
2.3
2.0
2.0
2.1
U6065
3.1
2.8
2.9
2.8
2.7
3.0
3.1
2.9
2.8
U6928
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.2
1.1
U6929
1.2
1.2
1.2
1.2
1.1
1.2
1.2
1.2
1.0
U6951
1.5
1.5
1.5
1.5
1.5
1.6
1.7
1.6
1.4
U6977
1.3
1.3
1.3
1.3
1.2
1.3
1.4
1.4
1.1
U6936
2.4
2.5
2.4
2.6
3.2
2.6
2.6
2.7
2.6
U6938
2.1
2.1
2.1
2.2
2.3
2.3
2.3
2.3
2.3
U6972
2.4
2.4
2.5
2.4
2.5
2.8
2.8
2.8
2.5
U6987
5.1
4.5
4.4
5.0
5.5
5.7
5.4
5.7
7.0
U7316
1.2
1.1
1.1
1.1
1.1
1.3
1.3
1.3
1.1
U7321
1.5
1.4
1.4
1.4
1.5
1.6
1.6
1.6
1.5
U7324
1.3
1.2
1.3
1.2
1.2
1.4
1.4
1.4
1.2
U7317
2.0
1.6
1.7
1.7
1.6
1.9
1.9
1.8
1.6
U7318
2.8
2.7
2.9
2.9
2.6
3.3
3.4
3.3
2.7
U7320
2.0
1.9
1.9
1.9
2.2
2.0
2.1
2.1
2.2
U7322
1.8
1.7
1.7
1.7
1.5
1.7
1.8
1.7
1.4
U7708
1.6
1.6
1.6
1.6
1.6
1.7
1.7
1.7
1.7
U7713
1.4
1.6
1.6
1.6
1.5
1.6
1.6
1.6
1.5
U7727
1.7
1.7
1.7
1.8
1.7
1.9
1.9
1.9
1.9
U7794
1.9
1.8
1.9
1.8
1.6
1.7
1.8
1.7
1.6
U7707
2.2
2.2
2.3
2.3
2.3
2.3
2.3
2.3
2.2
U7710
2.3
2.5
2.6
2.7
2.8
2.7
2.9
3.0
3.0
U7724
2.4
2.4
2.5
2.6
2.7
2.7
2.7
2.8
2.9
U7738
2.4
2.3
2.4
2.5
2.2
2.4
2.5
2.6
2.3
U8559
1.6
1.4
1.4
1.4
1.3
1.6
1.7
1.6
1.3
U8570
1.2
1.2
1.2
1.2
1.3
1.2
1.2
1.2
1.3
U8575
0.9
0.8
0.8
0.8
0.8
0.9
0.9
0.9
0.8
U8555
2.6
2.4
2.5
2.6
2.6
2.9
3.1
3.0
2.6
U8558
2.3
2.2
2.3
2.3
2.2
2.3
2.3
2.4
2.4
U8563
2.2
2.3
2.3
2.4
2.3
2.4
2.4
2.5
2.5
U9031
2.1
2.4
2.3
2.3
2.5
2.6
2.4
2.3
2.4
U9032
1.7
1.7
1.7
1.7
1.6
1.9
1.9
1.7
1.5
U9040
1.4
1.4
1.4
1.4
1.2
1.4
1.4
1.3
1.1
U9034
3.0
2.9
2.8
3.0
4.0
3.4
3.4
3.5
3.8
U9039
2.7
3.0
3.2
3.1
3.1
3.2
3.2
3.2
3.3
U9049
3.5
3.3
3.5
3.5
3.5
3.6
3.8
3.6
3.7
U9055
2.4
2.1
2.1
2.2
2.1
2.4
2.4
2.4
2.1
U0048
1.8
1.8
1.8
1.8
1.7
1.9
2.0
2.0
1.8
U0050
1.8
1.7
1.8
1.8
1.7
1.9
2.0
2.0
1.7
U0056
1.6
1.5
1.5
1.5
1.4
1.8
1.8
1.7
1.5
U0047
2.1
1.7
1.8
1.8
1.6
2.0
2.1
2.0
1.7
U0058
3.2
2.8
2.9
3.0
3.0
3.3
3.4
3.2
3.3
U0060
2.2
2.1
2.1
2.2
2.1
2.2
2.2
2.2
2.3
U0062
2.8
2.6
2.7
2.8
2.7
3.0
3.2
3.2
2.9
[0000]
TABLE 9
COMPARATIVE RESULTS
Comparison
on
n
r
m
b
Std. Error
Ng
Lassen
GInr vs
129
0.997
0.879
0.163
0.079
7/129 =
Delta <= 0.4|5 @ 96.1%
GATFa
5.4%
Delta <= 0.7|2 @ 98.4%
GInr vs
129
0.986
0.948
0.078
0.162
3/129 =
Delta <= 0.4|4 @ 96.9%
GATFz
2.3%
Delta <= 0.7|2 @ 98.4%
GInr vs
129
0.974
0.935
0.413
0.221
20/129 =
Delta <= 0.4|16 @ 87.6%
GATFt2
15.5%
Delta <= 0.7|4 @ 96.9%
MInr vs
129
0.996
0.921
0.122
0.092
9/129 =
Delta <= 0.4|2 @ 98.4%
MATFa
7.0%
Delta <= 0.7|0 @ 100.0%
MInr vs
129
0.989
0.908
0.190
0.155
7/129 =
Delta <= 0.4|4 @ 96.9%
MATFz
5.4%
Delta <= 0.7|2 @ 98.4%
MInr vs
129
0.983
0.893
0.491
0.193
8/129 =
Delta <= 0.4|13 @ 89.9%
MATFt2
6.2%
Delta <= 0.7|4 @ 96.9%
[0123] Table 9 provides comparative data for the ATFa, ATFz and ATFt2 and INR values calculated by the WHO method for each respective location, with GInr representing one location for these traditionally WHO determined values, and MInr representing values based on data obtained at the other location. The values identified as ATFz and ATFt2, such as, GATFt2 and MATFt2, and GATFz and MATFz, represent anticoagulant therapy factors derived from the expressions (1) through (9) above, inclusive of expressions (5.1) and (8.1).
[0124] Further comparative results are provided in Table 10 to illustrate the effect of prothrombin time (PT) on INR values. Table 10 provides a comparison based on data from Table 3, and provides INR values for PT's of PT=PT (under the heading “INR”), PT=PT+0.5 (under the heading “+0.5”), PT=PT+1.0 (under the heading “+1.0”), PT=PT+1.5 (under the heading “+1.5”), and PT=+2.0 (under the heading “+2.0”). The new anticoagulation therapy factor (ATFt2) was compared with the WHO method for determining ATF. The WHO method utilizes the mean prothrombin time of 20 presumed normal patients. The thromboplastin reagents list MNPT “expected ranges” listed in the accompanying thromboplastin-reagent (Tp) brochures. These brochures acknowledge that MNPT differences are inevitable because of variations in the 20 “normal donor” populations. Geometric, rather than arithmetic mean calculation limits MNPT variation somewhat, but simulated 0.5 second incremented increases over a total 2.5 second range, show ever-increasing INR differences notably at higher INR levels. To exemplify this, Table 10 shows these changes with Thromboplastin C Plus (which has a manufacturer's reported ISI=1.74 and MNPT=9.89 seconds) in POTENS+.
[0000]
TABLE 10
ID
PT
INR
+0.5
+1.0
+1.5
+2.0
WEC
9.8
1.0
0.9
0.8
0.8
0.7
A095
12.5
1.5
1.4
1.3
1.2
1.1
A191
14.8
2.0
1.9
1.7
1.6
1.5
A112
16.9
2.5
2.3
2.2
2.0
1.8
A208
18.6
3.0
2.8
2.5
2.3
2.2
A020
20.3
3.5
3.2
3.0
2.7
2.5
A164
21.9
4.0
3.7
3.4
3.1
2.9
A093
24.5
4.9
4.5
4.1
3.8
3.5
A055
26.5
5.6
5.1
4.7
4.4
4.0
A090
28.5
6.3
5.8
5.3
4.9
4.6
R091
32.2
7.8
7.2
6.6
6.1
5.7
A058
33.8
8.5
7.8
7.2
6.6
6.2
[0125] Since the in-house determined MNPT would continue with that Tp lot, intralaboratory results would be relatively unaffected. However, between laboratory INR agreements, or interlab results, are compromised. As a denominator, considering the expression used to derive the MNPT, such as expression (B), above, MNPT is, of course, less problematic for INRs than the exponent, ISI. Comparative results, showing interlab results, are provided in Table 11. ATFt is seen to be numerically equal to WHO/INRs determined in both analytical instruments, namely, the MDA-Electra 9000C and the POTENS+. Identical computer bits derived in POTENS+ from the absorbances creating the thrombin-fibrinogen-fibrin clotting curve are used for the POTENS+WHO/INR and ATFt (NO ISI, NO MNPT) determinations. MNPT is, of course, still necessary for the WHO method. For ATFt, Zero Order Kinetics Line's slope is extended in both directions to intersect with the Tp-plasma baseline and the absorbance at total fibrin formation. The sum of this interval and the time from the Tp injection to the beginning of Zero Order Kinetics (T 2 S) is Value 1. Value 2 is T 2 S/100e. “e” is the Natural Logarithm, base 2.71828. ATFt=(Value 1)*(Value 2), in accordance with expression (4) herein (and the expression (8.1) for ATFt2).
[0126] Table 11 provides statistical comparisons for results obtained using two POTENS+coagulometers (one designated as GINR and another designated as MINR), and using a Bio Merieux MDA-180 coagulometer (designated as AINR). The POTENS+, WHO/INRs, INR z s, and ATFts and the MDA-180 (AINR) WHO/INRs are compared. Statistical data and Bland-Altman plot data demonstrate that the new anticoagulant therapy factor ATFt may replace WHO/INR and provide results which are within the parameters of traditional therapeutic or reference ranges.
[0000]
TABLE 11
“r”
“m”
“b”
StdErr
StdDev
mY
mX
My/mX
AINR
GINR
0.937
0.872
0.290
0.388
1.148
2.169
2.155
1.007
vs
GATFz
0.941
1.119
−0.208
0.378
1.022
2.169
2.124
1.021
GATFt2
0.951
1.003
0.146
0.343
1.081
2.169
2.016
1.076
MINR
0.950
1.018
−0.126
0.349
1.070
2.169
2.253
0.963
MATFz
0.943
1.020
−0.040
0.371
1.065
2.169
2.167
1.001
MATFt2
0.937
0.872
0.290
0.388
1.148
2.169
2.155
1.007
MINR
GINR
0.971
1.036
0.039
0.247
1.001
2.253
2.136
1.055
vs
MINRz
GINRz
0.984
1.082
−0.132
0.186
0.978
2.167
2.124
1.020
vs
MINRt2
GINRt2
0.979
1.110
−0.083
0.242
1.123
2.155
2.016
1.069
vs
[0127] The linear regression analysis expression y=mx+b, when solved for the slope, m, is expressed as (y−b)/x. This is biased, so the expression is y/x is when b is equal to zero. The comparison in Table 11, above, provides comparative data for mean y (mY) and mean x (mX) values, including the slope mY/mX. The use of mY/mX is used to provide comparative results.
[0128] In another embodiment, an article may be provided to derive an anticoagulant therapy factor (ATF). The article may comprise stored instructions on a storage media which can be read and processed with a processor. For example, the computer may be provided with a stored set of instructions, or chip, which is programmed to determine a new ATF for the spectral data obtained from the coagulation activity of a sample. For example, the computer chip may be preprogrammed with a set of instructions for cooperating with the output of a photodetection device, such as, the device shown and described in FIG. 1 , which provides electrical data to said computer processor and/or storage device as a function of the optical density for a sample being analyzed. The chip may be employed in, or used with, an apparatus having input means and storage means for storing data. The set of instructions on the chip includes instructions for carrying out the steps of determining one or more anticoagulant therapy factors based on the expressions (1) through (9), inclusive of expressions (5.1) and (8.1).
[0129] According to alternate embodiments, methods for determining an anticoagulant therapy factor are provided to derive an INR. The customary classical INR (also referred to herein as INR m ) has been the laboratory standard of care for monitoring oral anticoagulant therapies, such as, for example, coumarin therapy, for 25 years. However, the classical INR (INRm) which is discussed in the background, above, is cumbersome, and suffers from exponential inaccuracies. According to an alternate embodiment, the exponent-derived INR m (that is, the manufacturer's INR) may be supplantable by carrying out a clotting reaction and recording absorbance values over time intervals. The alternate INR (INRn) may be determined by computing the representative area of a trapezoid formed within the clotting curve absorbance, as determined by the absorbance values for the clotting reaction of a patient sample. According to preferred embodiments, the trapezoidal area is provided to approximate area under the clotting curve. According to this embodiment, the ISI and MNPT are eliminated. The sample of a person's blood or blood component is obtained and reacted with the coagulant, such as thromboplastin C, and the corresponding time and absorbance values for the clotting reaction of the sample are recorded.
[0130] The INRn may be used to determine and regulate treatment for a patient, including administration of anticoagulant therapy, and other blood therapy applications. According to one embodiment of the method, obtaining values for an area in connection with a blood clotting analysis is used to derive a corresponding INR value (INRn) (e.g., a value that may be used as the INR value is used). For example, according to a preferred embodiment, an Area T, which may be made up of two sides S1 and S2, an upper base S3 and a lower base S4, may be derived to generate an INR value, INRn. An INRn value may be derived from clotting curve data, wherein one or more locations along the clotting curve may be used to determine values corresponding to a designated area, as in accordance with preferred embodiments, may be represented by a trapezoidal area, such as that area represented by Area T. According to a preferred embodiment, the area is a two dimensional planar location, and, for example, may comprise a designated area located in a quadrant of an ordinate and abscissa corresponding with clotting curve time and absorbance values. The clotting curve and absorbance values, preferably, may be obtained with the use of a photodetection apparatus, and a computer that records the electrical output of the detection components. For example, a linear-output photo-optical coagulometer may be used to obtain optically responsive signal data from the sample, as the clotting reaction takes place. This reaction and absorbance data collection may be conducted as described herein in conjunction with the use of a coagulometer, such as the instrument illustrated in FIG. 1 , or other suitable absorbance measuring device. Preferred devices are described herein and may be configured with the instructions to provide the INRn.
[0131] As illustrated in connection with FIG. 6 , a clotting curve is shown. An Area T is identified in the first quadrant where the clotting curve of a coagulation reaction is illustrated. The Area T derivation may be used to derive a corresponding INRn value for the patient sample that generated the information represented by the clotting curve. The INRn values obtained by the method and apparatus are useful in determining the treatment course for an individual, based on the INRn value.
[0132] According to a preferred embodiment, the INRn may be expressed with the following formulae:
[0000] INRn=(Area T )*MUL (10)
[0133] The MUL is a multiplier that is based on two relationships that are addressed by the multiplier. MUL relates the sampling rate of the instrument and the pixel parity of the x-y axis. The instrument used to measure the optical changes in the sample generates values, and preferably, the values, or signals are taken at a particular frequency. For example, a preferred sampling rate for the clotting curve reaction of a patient blood or blood component sample may be a number of optical absorbance values in a particular time interval. A preferred rate, for example, may be 100 optical absorbance values (or samples) per second, expressed 100/second. The sample rate preferably is used to derive a multiplier component, MUL. Also used to derive the multiplier component is the parity value, which is a multiplier utilized to create x-y pixel parity for the clotting curve information (that is shown expressed on the clotting curve graph, see FIG. 6 ). According to the example illustrated, the sampling rate used was 100 values per second. The pixel parity multiplier was 0.535. The multiplier, according to this example, is 0.535 (pixel parity value)/100 (the number of samples reflected in a second). The multiplier, or MUL, according to a preferred embodiment, was 0.00535.
[0134] In order to derive the INRn, the clotting curve is considered, and the theoretical or hypothetical zero order kinetic line, or line L as it is referred to and appears on the Figures, provides an (x,y) coordinate of (TEOT, 0), where the time value at which the clotting reaction, if theorized from the slope or line taken between the point where the maximum acceleration of the conversion rate of fibrinogen transformation begins (T2S) and the end of the maximum conversion (which is the last highest delta value of conversion rate), which is T2 or Tmap. The value, TEOT, is a time value, and generally, for example, may be expressed in seconds. As illustrated, the right side S2, may be designated to correspond with the line formed between the point (t1, c1) and TEOT. According to an alternate embodiment, the slope of the line L may corresponds with the slope of the side S2 of trapezoidal Area T. For example, according to some embodiments, the line L may form the side S2 of the trapezoid whose area is illustrated as Area T.
[0135] As shown in the preferred embodiments illustrated in FIGS. 6 and 7 , a segment of the line from TEOT and the point on the clotting curve T1, forms the trapezoid side S2.
[0136] With the multiplier MUL, the INRn may be derived according to the following expression:
[0000] INRn=(( T 1+TEOT)/2)*0.00535 *T 2 (11)
[0137] As illustrated in FIG. 7 , the lower base, S4, of the trapezoid TP, is the time value of the theoretical or hypothetical end of the coagulation test, TEOT. The time value component TEOT includes the time value of T2 plus the time value (Tiut) to convert the remainder of the fibrinogen in the sample that is considered to provide active optical activity (by the theoretical time value of the end of the test, TEOT). Both the Teot and TSot are values that are determined from the absorbance readings for a sample in a coagulation reaction. Dividing the difference in Instrument Units (RU)@ T2S to IU@ T2 (which is IUX) by the time it takes this conversion T2S to T2 (which may be represented by the time interval, Tiux) gives the maximum transformation rate for a specific sample. Using this specific test rate (UX/Tiux), it is determined how long it would take to convert the fibrinogen from T2S to T3 (end of test) and add this value to T2S. This gives the TEot. Another value listed in the data Table 14 is the TSot which is the hypothetical start of test. The TSot is similar to the TEot, the hypothetical end of test. (The TEot, according to some embodiments, also may be referred to herein as a theoretical end of test.) The time that it takes to convert the IU@T1 to IU@T2S (which may be expressed as the difference between T1 and T2S (the value Tcon)) may be determined using the same rate of change. The TSot is determined by subtracting the time (Tcon) from T2S to give the TSot. The TSot may come before or after T1 and the TEot will always come before T3.
[0138] Referring again to FIG. 7 , an upper base, S3, is indicated to correspond with the time of the start of the clot formation when the coagulation reaction is carried out. The start time of the clotting is represented by the time, T1, as shown in FIG. 6 . With the upper and lower bases, S3 and S4, respectively, being ascertained through the clotting reaction times, they may be averaged (e.g., divided by 2). The S3, S4 average may be used to derive a trapezoidal area, such as, for example, Area T, represented by the clotting absorbance signal data. The altitude S1 (or height) of the trapezoidal area, Area T, is derived by the value of the point of time (T1) where the beginning of the conversion of fibrinogen to fibrin for the patient sample is determined. That point is represented as time value T1 on FIGS. 6 and 7 . The height component of the trapezoid represented by Area T is designated to correspond with the side S1. The height component is assigned the value T1*MUL (T1 multiplied by the multiplier).
[0139] The INRn may be determined for a patient sample by determining (i) when the clot formation begins, which is represented by the time value T1, (ii) when the clotting commences a maximum conversion rate (of conversion of fibrinogen to fibrin in the patient sample), which is represented by the time value T2, and (iii) the end of the maximum conversion rate, represented by the time value T3 (the end of the maximum conversion rate). Therefore, according to embodiments of the present method and apparatus, a new INR determination that, through the transformation of information (e.g., signals corresponding to optical activity of a clotting reaction), may be derived by (i) determining the start of the clotting when a reagent (such as, for example, thromboplastin C) is reacted with a blood or blood component sample of a person (by determining the length of time from the introduction of the reagent and sample to the time clotting begins, which is T1), (ii) determining the start of the maximum acceleration rate of conversion for the clotting reaction that began at time T1) which is represented by the time T2, and (ii) determining the value of the end of the maximum conversion rate for the clotting reaction, which is represented by the value T3.
[0140] The present method and apparatus may be used to derive an INR, IRn, which does not utilize exponential components, and therefore, is not subject to exponential inaccuracies that have previously been experienced in connection with traditional INR determinations. The INRn value may be used to monitor a patient's blood or blood components for administration of oral anticoagulant therapy, such as, for example, coumarin, and other treatment agents, including those discussed herein. The present method and apparatus preferably, according to a preferred embodiment, where INRn is derived (and may be used for treatment administration of anticoagulant therapy).
[0141] The clotting curve illustrates a representation of absorbance values for a clotting reaction where substantially optically clear fibrinogen converts to turbid fibrin, hence reducing the absorbance unit values, as indicated on the abscissa. The point of intersection of the line L with the x-axis, or the time axis, preferably, may be derived using the value T2S and adding to that time value, the time required to convert additional fibrinogen in the sample, which is the time value corresponding with the absorbance value IUT (in instrument units). The TEOT value may be derived from the intercept that the slope of the line L defined by T2S and T2 makes with the x-axis. However, as described herein, the x axis would, in theory, be where y=0, and accordingly, since some signal may be detected (and hence not zero), the trapezoidal lower base S4 ( FIGS. 6 and 7 ) may be represented along y=Ceot, between times T0 and TEot. According to a preferred embodiment, the TEOT value may be derived by the following determination:
[0000] TEOT=T2S+(ZTM/IUX*IUT) (12)
[0000] where ZTM is the time (in seconds) to convert the fibrinogen corresponding to the time interval between T2S and T2, or in other words, the time to convert the IUX absorbance value (the IUX being the difference between instrument units (or IU) at T2S (IU@T2S) and instrument units at T2 (IU@T2)). The IUT value is the difference between instrument units (or IU) at T2S (IU@T2S) and instrument units at T3 (IU@T3).
[0142] A method was carried out using the Dade Behring Thromboplastin C Plus (Dade TPC+) as the reagent. The number of patient samples that were reacted and used to obtain the following data was 218. The WHO INR (the World Health Organization INR is the average of INR values from five different thromboplastins. The INRm is the manufacturer's INR. INRz is the INR that is derived using the exponent (2-FTR) instead of the ISI (as described herein (see formulae (1), (2), (3), (3.1), above). INRn (uses no ISI and no MNPT values for its determination) and is the calculation for the INR in accordance with the alternate embodiment described herein and represented by the formula INRn=((T1+TEOT)/2)*0.00535*T2, which is formula (II), above.
[0143] Coagulation reactions were carried out for a number of individuals, using the blood samples from the individuals, prepared as indicated herein in connection with clotting reactions, where a clotting reagent is added to the blood sample, and preferably a blood plasma sample. The absorbance values (measured in instrument units) were obtained for the sample throughout the coagulation reaction using a linear-output photo-optical coagulometer, POTENS+. The clotting agent used was thromboplastin reagent (Tp) which was injected into citrated human blood plasma. The clotting curve absorbance values were tracked as optically-clear fibrinogen (Fg) (also referred to as FBG herein) converts into turbid fibrin. The table below provides the values of the absorbance and time data that was obtained. By extending the slope L derived by the slope of the curve where the maximum conversion rate of fibrinogen occurs, a trapezoid is formed whose area may be derived and used to provide a value, INRn, which is essentially equal to the traditionally obtained INR values.
[0000]
TABLE 12
Comparative Summary
INR WHO
(INRw)
NG
LASSEN Agreement
Poller
Highest
Versus
Discordant
<=0.4
<=0.7
Diff >10%
Percent
vs. INR M
13.8%
85.3%
95.9%
9/218
4.1%
18.3%
vs. INR Z
10.1%
89.4%
96.3%
7/218
3.2%
15.2%
vs. INR N
9.2%
88.5%
96.3%
12/218
5.5%
14.8%
[0144] Table 12 provides comparative data for INRn, INRz and INRn values compared with INR values calculated by the INR WHO method (which is also represented as INRw). The INR obtained using the WHO method (INRw) was compared with each of the alternate INR determinations, including INRm (using the manufacturer's INR), INRz, using the expressions of the above formulae (1), (2), (3), (3.1), as discussed herein, and INRn, using the expressions of the above formulae (10), (11), (12).
[0145] Further details of the comparative data are provided in Table 13 to illustrate values for each of the INR WHO comparisons.
[0000] TABLE 13 COMPARATIVE SUMMARY DETAILS using DADE TPC+ Thromboplastin WHO INR vs INRm Specimens Using NG algorithm Number of mismatches 30/218 = 13.8% Range <2.0 13(13, 0)/79 16.5% Range 2.0 to 3.0 12(10, 2)/91 13.2% Range >3.0 to 4.5 5(4, 1)/37 13.5% Range >4.5 0(0, 0)/11 0.0% Lassen values Samples: 218 delta <= 0.4 32@85.3% delta <= 0.7 9@95.9% WHO INR vs INRz Specimens Using NG algorithm Number of mismatches 22/218 = 10.1% Range <2.0 11(11, 0)/79 13.9% Range 2.0 to 3.0 5(4, 1)/91 5.5% Range >3.0 to 4.5 5(2, 3)/37 13.5% Range >4.5 1(0, 1)/11 9.1% LASSEN values Samples: 218 delta <= 0.4 23@89.4% delta <= 0.7 8@96.3% INRw vs. INRn Specimens Using NG algorithm Number of mismatches 20/218 = 9.2% Range <2.0 1(1, 0)/79 1.3% Range 2.0 to 3.0 13(4, 9)/91 14.3% Range >3.0 to 4.5 6(4, 2)/37 16.2% Range >4.5 0(0, 0)/11 0.0% LASSEN values Samples: 218 delta <= 0.4 25@88.5% delta <= 0.7 8@96.3%
The sample data upon which the above data summaries were based, is provided in Table 14. Table 14 provides corresponding data for a coagulation study. In Tables 14 and 15, the following references are used, and may be further identified by reference to FIG. 8 :
ID—Sample ID T0—Time of thromboplastin reagent injection T1—Start of the clot formation T2S—Start of maximum conversion rate T2—End of maximum conversion rate. (Last highest delta value of conversion rate.) T3—(T 4 −T 2s ) T4—Hypothetical End Of Test (HEOT) IU—Instrument unit IUT—Delta IU between IU@T2S and IU@T3 IUX—Delta IU between IU@T2S and IU@T2 IUA—Altitude component value of the trapezoidal area (in instrument units) (c1—ceot) IUL—Length component value of the trapezoidal area (in instrument units) ZTM—Time in seconds to convert the IUX (T2−T2S) TEOT—Hypothetical End Of Test. (Time at T2S plus the time to convert IUT.) TSot—Hypothetical Start Of Test Fg—Fibrinogen concentration of the blood sample (in g/l) c1—Absorbance value (in instrument units) at time of the start of the clot formation (T1) cT2S —Absorbance value (in instrument units) at the time of the start of maximum conversion rate (T2S) c2—Absorbance value (in instrument units) at time of the end of maximum conversion rate (T2). (Last highest delta value of conversion rate.) ceot—Absorbance value (in instrument units) at time TEOT
[0000]
TABLE 14
ID
WHO
INRm
INRz
INRn
T1
T2S
T2
T3
TSot
TEot
A001
3.00
3.08
2.55
2.38
18.89
22.04
23.89
49.55
19.66
29.44
A002
2.88
3.32
2.56
2.19
19.71
23.00
24.42
37.75
20.87
27.61
A003
2.78
3.33
2.55
2.41
19.75
23.10
25.48
37.55
20.94
28.51
A004
2.08
2.03
2.03
1.66
14.85
19.66
21.62
37.55
16.89
24.96
A005
2.30
2.87
2.31
2.04
18.11
21.69
23.83
37.55
19.36
26.75
A007
1.85
2.03
1.78
1.45
14.86
18.19
20.18
33.95
15.87
22.83
A008
2.83
2.62
2.42
2.17
17.22
21.59
23.63
41.95
18.97
28.20
A009
2.70
3.38
2.65
2.47
19.91
23.91
26.43
37.87
21.39
29.31
A010
1.65
1.88
1.61
1.24
14.22
17.16
19.27
30.15
14.73
21.38
A011
1.83
2.09
1.71
1.34
15.10
17.90
19.32
33.75
15.57
22.26
A012
2.68
3.17
2.47
2.03
19.21
22.40
23.94
36.95
19.78
27.33
A013
3.30
3.44
2.92
2.86
20.13
24.09
26.68
50.15
21.60
31.76
A014
1.60
1.78
1.55
1.12
13.76
17.01
18.35
30.15
14.78
20.43
A015
1.70
1.88
1.60
1.20
14.23
17.15
18.96
28.30
14.74
21.17
A016
2.73
3.02
2.53
2.14
18.68
22.33
23.35
45.75
19.91
27.94
A017
1.70
1.78
1.63
1.24
13.76
17.29
18.86
31.35
14.82
21.66
A018
2.18
2.17
1.91
1.60
15.44
18.77
21.23
34.55
16.09
24.36
A019
1.85
1.82
1.71
1.41
13.97
17.58
19.30
36.75
15.29
22.74
A020
3.80
3.52
2.93
2.75
20.40
25.35
28.02
42.75
22.47
31.31
A021
2.63
2.83
2.39
2.08
17.98
21.51
23.37
37.35
18.91
27.65
A022
2.08
2.18
1.92
1.59
15.46
19.01
20.55
36.75
16.65
24.14
A023
3.20
3.11
2.55
2.20
18.98
22.51
23.92
43.35
20.09
28.15
A024
3.03
3.39
3.05
2.81
19.94
25.22
27.22
45.28
22.66
31.44
A025
1.73
1.84
1.51
1.06
14.03
16.98
18.01
27.40
15.09
19.73
A026
1.45
1.60
1.45
1.11
12.94
15.96
17.58
31.69
13.53
20.52
A027
1.45
1.48
1.36
1.05
12.41
15.34
16.91
33.35
13.12
19.77
A028
1.90
1.93
1.73
1.41
14.41
17.80
19.22
39.15
15.38
22.98
A029
2.20
2.06
1.85
1.59
14.99
18.36
20.31
40.55
16.07
23.96
A030
2.50
2.61
2.25
2.05
17.17
20.52
22.08
48.75
18.18
27.54
A031
2.43
2.75
2.25
1.95
17.69
21.07
23.20
35.84
18.55
26.49
A032
3.63
3.83
3.33
2.88
21.40
25.84
26.78
48.15
23.33
32.26
A033
2.65
2.94
2.52
2.22
18.39
22.44
24.46
41.95
19.79
28.37
A034
2.08
2.24
1.96
1.69
15.71
19.14
20.89
38.95
16.92
24.62
A035
4.00
4.87
3.71
4.36
24.58
29.96
34.33
47.75
27.15
38.08
A036
2.98
3.19
2.51
2.47
19.26
21.94
24.50
43.55
19.89
29.11
A037
2.20
2.50
2.32
1.97
16.73
21.61
23.71
36.95
18.96
26.80
A038
1.45
1.57
1.35
0.99
12.82
15.48
16.81
29.69
13.15
19.36
A039
1.50
1.46
1.39
0.99
12.27
15.70
17.37
28.67
13.27
19.34
A040
2.28
2.39
2.06
1.79
16.33
19.59
21.24
39.75
17.17
25.75
A041
2.18
2.30
2.14
1.88
15.95
19.93
21.44
45.15
17.29
26.82
A042
3.40
4.07
3.36
3.15
22.16
26.65
29.21
49.35
23.45
33.90
A044
3.38
4.31
3.31
2.90
22.90
26.85
28.41
41.15
24.38
31.92
A045
2.60
2.70
2.44
2.26
17.52
21.56
24.20
45.75
18.92
28.64
A047
2.45
2.81
2.46
2.24
17.90
21.99
24.21
41.55
19.51
28.26
A048
3.38
3.82
3.13
3.15
21.35
25.34
28.49
46.15
22.61
33.32
A049
2.28
2.68
2.15
1.99
17.42
20.04
22.56
39.55
17.88
26.34
A050
2.70
2.80
2.49
2.17
17.86
22.06
24.08
40.75
19.20
28.46
A051
1.88
1.91
1.64
1.32
14.35
17.45
18.41
35.55
15.19
22.32
A052
2.55
2.82
2.31
2.05
17.94
20.98
22.93
40.35
18.50
27.36
A053
2.88
3.06
2.48
2.09
18.82
22.39
24.07
38.75
19.78
27.62
A054
1.90
2.07
1.78
1.48
15.04
18.09
20.21
33.15
15.84
22.99
A055
6.58
5.56
4.81
5.66
26.51
31.27
36.08
70.15
28.32
45.39
A056
3.48
3.58
3.19
3.09
20.60
25.34
27.68
53.15
22.73
33.17
A057
2.58
2.85
2.23
1.87
18.05
21.05
22.66
35.15
18.72
25.88
A058
7.40
8.47
7.73
8.65
33.76
41.78
45.33
79.97
37.98
55.47
A059
2.25
2.93
2.27
1.99
18.34
21.38
23.74
34.15
18.82
26.69
A060
2.43
3.15
2.54
2.21
19.12
23.19
25.32
36.55
20.59
28.16
A061
2.25
2.49
2.17
1.97
16.70
20.05
22.25
38.35
17.68
26.82
A062
6.35
6.20
6.43
6.80
28.21
37.32
40.28
78.95
33.62
49.72
A063
2.65
3.04
2.63
2.61
18.75
22.31
25.84
42.15
19.59
30.73
A064
2.05
2.21
1.92
1.55
15.59
19.19
21.08
32.55
16.76
23.78
A065
2.28
2.65
2.47
2.22
17.32
22.25
24.96
39.75
19.39
28.42
A066
1.83
1.99
1.67
1.24
14.69
17.83
19.19
30.15
15.50
21.52
A067
1.78
1.75
1.62
1.30
13.63
17.02
18.52
36.75
14.49
22.31
A068
2.68
2.65
2.13
1.90
17.30
19.97
21.86
37.35
17.76
26.11
A069
2.10
2.41
1.92
1.41
16.41
19.35
20.15
31.95
16.95
23.19
A070
1.65
2.38
1.97
1.58
16.29
19.40
20.80
37.55
16.92
24.25
A071
1.73
1.89
1.73
1.44
14.25
17.63
19.53
39.50
15.23
23.03
A072
1.60
1.82
1.69
1.45
13.97
17.27
18.98
43.55
14.80
23.54
A073
1.48
1.49
1.50
1.21
12.46
16.14
17.82
37.75
13.77
21.33
A074
1.65
1.71
1.59
1.26
13.44
16.86
19.03
33.35
14.56
21.33
A075
1.58
1.57
1.21
0.75
12.80
14.89
15.87
23.28
13.18
16.85
A076
1.45
1.44
1.37
1.11
12.18
15.39
16.78
37.55
13.01
20.65
A077
4.63
4.64
4.03
4.26
23.88
28.45
31.55
64.71
25.61
39.30
A078
2.05
2.16
1.88
1.64
15.41
18.55
20.89
35.71
16.35
24.06
A080
6.13
7.35
6.42
8.00
31.12
35.48
40.50
86.95
32.86
55.56
A081
3.55
3.76
3.63
3.30
21.18
26.98
28.55
57.95
23.84
35.22
A082
1.53
1.54
1.55
1.29
12.69
16.24
18.15
43.55
13.76
22.16
A083
1.60
1.60
1.38
0.98
12.97
15.82
16.98
28.23
13.50
19.41
A084
6.98
6.67
5.72
6.91
29.43
33.64
38.19
76.55
30.96
51.04
A085
3.10
3.27
3.01
3.29
19.55
24.14
29.21
48.15
21.22
34.28
A086
2.45
2.85
2.35
2.11
18.07
21.11
22.84
46.95
18.57
27.93
A087
1.93
1.84
1.69
1.40
14.06
17.40
19.24
37.00
15.03
22.74
A088
1.78
1.71
1.64
1.35
13.44
17.15
18.79
37.95
14.80
22.43
A089
2.18
2.28
1.83
1.44
15.90
18.76
20.00
33.95
16.62
22.82
A090
5.93
6.31
5.59
6.68
28.51
33.63
38.36
84.35
30.64
49.81
A091
8.23
7.68
6.96
7.83
31.91
38.95
42.75
74.75
35.15
53.48
A092
2.00
1.91
2.03
1.81
14.36
19.10
21.48
50.15
16.41
26.06
A093
4.30
4.86
3.81
4.26
24.53
28.21
31.94
53.15
25.81
38.07
A094
2.53
3.17
2.94
2.41
19.18
24.61
25.77
42.95
22.06
29.60
A095
1.43
1.50
1.43
1.15
12.48
15.73
17.24
37.76
13.36
20.91
A096
1.80
2.12
1.69
1.29
15.22
17.85
19.14
30.95
15.59
21.88
A097
1.40
1.32
1.11
0.76
11.59
13.74
14.88
27.05
11.21
17.41
A098
1.45
1.40
1.32
1.04
11.98
14.78
16.59
34.95
12.54
19.69
A099
1.53
1.81
1.52
1.17
13.93
16.63
18.24
30.15
14.48
20.60
A100
1.40
1.41
1.40
1.18
12.06
15.39
17.01
39.15
13.23
21.06
A101
2.45
2.76
2.39
2.26
17.71
21.22
24.16
42.97
18.67
28.47
A102
3.83
3.79
3.13
2.90
21.28
24.77
25.93
56.17
22.32
32.50
A103
2.15
2.03
1.94
1.74
14.84
18.67
20.63
45.75
16.35
25.35
A104
3.10
3.21
2.96
3.01
19.32
23.44
27.32
50.53
20.39
33.69
A105
3.85
3.69
3.15
3.34
20.93
24.28
26.92
63.15
22.14
35.01
A107
2.53
2.84
2.42
2.36
18.01
21.27
23.85
50.16
19.06
28.89
A108
1.95
2.08
1.85
1.55
15.06
18.37
20.98
32.12
15.76
23.83
A109
2.28
2.27
2.06
1.85
15.86
19.19
22.04
38.31
16.53
26.22
A110
3.83
3.91
3.72
4.05
21.65
26.20
29.96
67.75
23.26
39.93
A111
2.90
2.52
2.39
2.35
16.84
20.64
24.09
45.11
18.13
29.42
A112
2.30
2.39
2.22
2.13
16.33
20.00
22.03
56.41
17.63
28.46
A113
1.80
1.87
1.65
1.41
14.17
16.98
18.78
38.35
14.73
22.94
A114
1.90
2.10
1.87
1.65
15.13
18.38
20.51
43.35
16.14
24.34
A115
2.10
2.38
2.30
2.03
16.26
20.91
22.84
47.35
18.27
27.41
A116
1.78
1.73
1.40
1.07
13.53
15.66
17.28
29.70
13.64
19.58
A117
1.65
1.62
1.65
1.45
13.04
16.91
18.76
49.15
14.58
23.34
A118
1.98
2.18
1.80
1.46
15.46
18.36
19.65
35.35
16.10
23.20
A119
2.65
2.98
2.43
2.32
18.53
21.29
23.20
48.14
19.06
29.09
A120
1.85
2.11
1.79
1.48
15.18
18.33
19.61
34.35
16.20
23.17
A121
2.05
2.21
1.82
1.58
15.60
18.24
20.28
36.04
16.20
23.54
A122
1.55
1.76
1.64
1.42
13.70
16.76
18.82
42.35
14.50
22.94
A123
1.70
1.81
1.55
1.25
13.91
16.51
18.38
31.51
14.27
21.37
A124
1.63
1.80
1.46
1.08
13.85
16.27
17.67
29.01
13.94
20.16
A125
1.50
1.39
1.26
1.04
11.93
14.86
15.88
37.95
12.41
20.50
A126
3.25
3.70
2.97
3.02
20.99
25.08
28.61
41.35
22.26
32.49
A127
2.20
2.38
2.05
1.83
16.28
19.39
20.92
51.15
16.81
26.47
A128
3.38
3.89
3.06
2.64
21.58
24.88
26.01
47.86
22.48
30.67
A129
4.35
5.25
4.67
4.77
25.65
30.83
33.84
60.80
27.13
42.64
A130
4.05
4.66
4.55
4.16
23.94
31.39
33.06
58.52
28.41
38.43
A131
1.63
1.72
1.68
1.42
13.49
17.05
19.42
34.86
14.68
22.81
A132
2.43
2.65
2.75
2.62
17.33
22.89
26.55
47.95
19.39
31.64
A133
2.65
2.64
2.56
2.63
17.27
21.32
25.37
48.11
18.85
31.00
A134
6.33
6.48
6.27
6.27
28.95
36.89
39.54
62.23
32.81
48.31
A135
1.40
1.49
1.32
0.97
12.42
15.07
16.62
30.63
12.59
19.31
A136
4.38
4.33
3.63
3.63
22.96
26.93
29.17
62.05
24.27
36.17
A137
1.58
1.96
1.73
1.33
14.56
18.09
19.56
35.32
15.80
22.09
A138
2.18
1.99
2.04
1.74
14.69
19.49
21.15
46.15
16.78
25.69
A139
2.05
2.12
1.97
1.78
15.24
19.05
20.42
48.75
16.77
25.90
A140
1.35
1.34
1.28
1.01
11.72
14.83
16.21
38.35
12.55
19.52
A141
2.05
2.22
1.87
1.52
15.65
18.77
20.00
34.32
16.40
23.78
A142
3.10
3.36
2.60
2.24
19.86
23.90
25.80
37.58
21.43
28.27
A143
2.08
2.56
2.23
2.08
16.97
20.55
23.80
37.75
17.91
27.25
A144
2.20
2.44
2.12
1.76
16.53
20.17
21.49
41.68
17.76
25.45
A145
1.28
1.38
1.28
0.99
11.91
14.81
16.17
36.48
12.38
19.53
A146
2.48
2.26
1.98
1.80
15.81
18.99
20.67
49.55
16.66
25.97
A147
1.48
1.64
1.45
1.10
13.14
16.08
17.38
34.14
13.57
20.59
A148
2.18
2.38
2.07
1.79
16.28
19.67
21.10
46.95
17.00
26.15
A149
1.33
1.52
1.41
1.05
12.57
15.82
17.19
34.20
13.23
20.16
A150
1.45
1.55
1.40
1.14
12.72
15.57
16.97
39.21
13.27
20.78
A151
2.83
2.80
2.52
2.42
17.89
21.77
24.31
56.93
19.30
29.60
A152
1.85
2.19
1.82
1.34
15.50
18.79
20.08
33.19
16.21
22.66
A153
1.73
1.77
1.64
1.41
13.75
17.14
18.49
46.91
14.70
23.25
A154
2.30
2.29
1.97
1.75
15.94
18.86
20.90
41.84
16.50
25.41
A155
4.98
4.80
3.87
4.77
24.37
29.06
35.08
53.55
26.05
40.50
A156
2.80
2.77
2.40
1.89
17.76
21.91
23.03
40.00
19.35
26.55
A157
2.03
2.22
1.87
1.52
15.64
18.86
20.65
36.62
16.47
23.51
A158
3.43
3.64
2.84
2.55
20.79
24.24
25.84
44.53
22.00
29.68
A159
3.78
3.94
3.60
3.72
21.74
26.43
29.76
61.35
23.28
37.47
A160
2.58
2.74
2.47
2.40
17.64
21.60
24.95
44.35
18.99
29.29
A161
1.68
1.66
1.60
1.31
13.24
16.74
18.54
35.95
14.17
22.40
A162
7.33
6.56
5.90
6.52
29.16
34.82
38.19
74.78
31.45
49.35
A163
3.90
3.90
3.15
3.04
21.62
25.10
27.09
49.55
22.75
32.70
A164
3.45
3.79
3.19
2.83
21.28
25.53
26.93
47.44
23.08
31.66
A165
2.63
2.60
2.25
1.96
17.13
20.69
22.34
43.75
18.17
26.86
A166
2.05
2.19
1.91
1.62
15.52
18.84
20.12
42.98
16.44
24.60
A167
2.65
3.00
2.45
1.91
18.61
22.28
23.38
36.00
19.77
26.68
A168
3.60
3.61
3.03
3.20
20.68
23.69
25.98
51.55
21.61
34.72
A169
3.78
4.13
3.34
3.14
22.35
25.61
26.64
60.89
23.24
33.75
A170
1.30
1.37
1.24
0.88
11.84
14.56
16.01
30.00
12.18
18.39
A171
3.18
3.41
2.94
3.02
20.01
24.48
27.83
47.95
21.97
32.30
A172
2.58
2.58
1.99
1.71
17.06
19.43
20.73
39.75
17.41
24.63
A173
1.48
1.51
1.30
0.95
12.55
15.03
16.46
28.97
12.78
18.91
A174
1.88
1.84
1.60
1.31
14.04
16.86
18.51
36.75
14.60
21.98
A175
1.60
1.84
1.52
1.13
14.02
16.78
18.20
29.70
14.61
20.37
A176
3.08
3.33
2.82
2.72
19.75
23.45
25.14
50.35
21.34
30.91
A177
1.58
1.73
1.42
1.05
13.56
15.96
17.33
31.35
13.59
19.95
A178
2.53
2.34
2.16
1.89
16.13
20.20
21.83
43.07
17.75
26.41
A179
2.33
2.51
2.18
1.86
16.78
20.38
22.02
39.95
17.86
26.18
A180
2.18
2.26
1.88
1.59
15.79
18.80
20.33
36.32
16.66
23.85
A181
3.68
3.49
3.21
3.44
20.29
25.17
29.85
51.67
21.98
35.38
A182
2.05
2.10
1.78
1.44
15.15
18.28
19.30
39.14
15.93
23.28
A183
1.53
1.55
1.30
0.91
12.70
15.24
16.46
28.49
12.95
18.59
A184
2.48
2.58
2.22
1.96
17.06
20.49
21.89
47.65
18.04
27.02
A185
3.05
3.28
2.96
2.87
19.59
24.06
26.64
54.15
21.37
32.25
A186
3.10
3.12
3.09
3.58
19.01
22.19
29.51
65.55
19.65
37.28
A187
1.75
1.83
1.51
1.18
13.99
16.52
17.86
34.85
14.22
21.02
A188
2.93
3.12
2.56
2.46
19.01
22.29
24.63
36.67
20.11
29.31
A189
2.93
2.98
2.68
2.47
18.52
23.20
25.87
44.13
20.26
30.01
A190
3.25
3.59
3.00
2.75
20.62
24.60
26.72
44.63
21.77
31.67
A191
2.05
2.04
1.71
1.39
14.91
17.82
19.08
34.18
15.77
22.39
A192
2.28
2.49
2.25
1.81
16.69
21.28
22.69
39.02
18.88
25.65
A193
1.95
2.11
1.84
1.64
15.20
17.86
20.52
39.35
15.51
24.43
A194
2.18
2.27
1.98
1.72
15.83
19.27
21.44
36.83
16.93
24.78
A195
1.45
1.37
1.46
1.17
11.86
15.76
17.48
34.90
13.23
21.30
A196
1.95
1.99
1.82
1.56
14.68
18.04
20.23
42.94
15.59
23.97
A197
1.63
1.78
1.62
1.28
13.76
17.46
18.33
41.41
15.35
21.69
A198
1.85
1.92
1.66
1.43
14.39
16.92
19.77
31.95
14.88
22.21
A199
1.40
1.49
1.32
0.94
12.42
15.08
16.68
28.38
12.57
19.08
A200
1.35
1.38
1.21
0.88
11.92
14.39
15.64
30.32
12.02
18.39
A201
2.40
2.56
2.19
1.96
16.97
20.37
22.05
42.55
18.13
26.53
A202
2.20
2.39
1.93
1.59
16.31
18.99
20.82
37.23
16.43
24.30
A203
1.80
2.07
1.67
1.28
15.04
17.69
18.76
36.37
15.26
22.07
A204
1.73
1.80
1.50
1.14
13.85
16.41
17.97
30.75
14.07
20.62
A205
1.85
1.87
1.84
1.46
14.19
18.51
20.05
39.13
15.79
23.60
A207
2.65
2.75
2.42
2.11
17.69
21.70
23.07
45.74
19.37
27.59
A208
3.05
3.04
2.63
2.62
18.75
22.27
25.50
45.50
19.80
30.63
A209
1.70
1.84
1.69
1.44
14.06
17.22
19.31
37.35
15.00
22.84
A210
2.35
2.37
1.95
1.58
16.23
19.23
20.54
39.33
16.76
24.32
A211
2.50
2.68
2.40
2.12
17.44
21.54
23.03
47.55
19.14
27.75
A212
2.88
2.77
2.44
2.18
17.78
21.82
23.45
43.47
19.54
27.85
A213
2.53
2.74
2.40
2.41
17.65
20.57
23.19
56.75
18.23
30.50
A214
2.60
2.80
2.44
2.38
17.86
21.07
24.24
44.75
18.53
29.52
A215
2.40
2.47
2.06
1.70
16.63
19.82
21.16
41.43
17.36
25.07
A216
4.48
4.13
3.86
3.78
22.33
27.99
30.59
58.40
24.70
37.52
A217
2.23
2.33
2.26
2.19
16.10
20.21
22.30
63.13
17.82
28.77
A218
2.95
2.94
2.82
2.70
18.38
23.22
25.69
59.95
20.39
31.65
A219
2.38
2.71
2.17
2.01
17.55
20.69
23.43
36.97
18.50
26.17
A220
1.90
2.05
1.74
1.34
14.92
18.06
19.41
34.75
15.57
22.53
A222
1.83
1.89
1.63
1.36
14.27
17.07
18.81
33.95
14.98
22.12
A223
1.73
1.74
1.41
1.05
13.60
16.00
17.00
31.79
13.57
20.14
A224
1.73
1.62
1.52
1.15
13.03
16.52
18.07
31.77
14.04
20.86
A225
1.68
1.81
1.52
1.18
13.93
16.59
17.97
32.58
14.29
20.96
[0000] TABLE 15 Table 15 provides additional data for the coagulation study of the samples in Table 14. ID Fg c1 ct2s C2 Ceot IUL IUX IUT IUA Ztm A001 388 3738 3720 3706 3664 18 14 56 74 1.85 A002 226 3724 3712 3704 3686 12 8 26 38 1.42 A003 213 3740 3730 3719 3705 10 11 25 35 2.38 A004 370 3733 3709 3692 3663 24 17 46 70 1.96 A005 226 3738 3726 3715 3700 12 11 26 38 2.14 A007 244 3740 3726 3714 3698 14 12 28 42 1.99 A008 482 3741 3714 3693 3646 27 21 68 95 2.04 A009 253 3741 3727 3713 3697 14 14 30 44 2.52 A010 240 3742 3727 3714 3701 15 13 26 41 2.11 A011 352 3713 3690 3676 3647 23 14 43 66 1.42 A012 276 3744 3727 3717 3695 17 10 32 49 1.54 A013 496 3739 3715 3690 3641 24 25 74 98 2.59 A014 226 3732 3717 3708 3694 15 9 23 38 1.34 A015 199 3738 3726 3717 3706 12 9 20 32 1.81 A016 340 3741 3722 3714 3678 19 8 44 63 1.02 A017 331 3742 3720 3706 3681 22 14 39 61 1.57 A018 218 3734 3722 3711 3697 12 11 25 37 2.46 A019 472 3744 3716 3695 3653 28 21 63 91 1.72 A020 246 3741 3727 3714 3698 14 13 29 43 2.67 A021 265 3741 3727 3717 3694 14 10 33 47 1.86 A022 387 3740 3717 3702 3667 23 15 50 73 1.54 A023 420 3743 3719 3705 3663 24 14 56 80 1.41 A024 415 3740 3717 3699 3661 23 18 56 79 2.00 A025 171 3743 3732 3726 3716 11 6 16 27 1.03 A026 363 3742 3718 3702 3673 24 16 45 69 1.62 A027 377 3739 3715 3698 3667 24 17 48 72 1.57 A028 463 3742 3713 3696 3651 29 17 62 91 1.42 A029 472 3740 3713 3690 3647 27 23 66 93 1.95 A030 540 3743 3716 3698 3635 27 18 81 108 1.56 A031 236 3728 3715 3704 3687 13 11 28 41 2.13 A032 309 3732 3716 3710 3675 16 6 41 57 0.94 A033 358 3739 3718 3702 3671 21 16 47 68 2.02 A034 349 3740 3721 3706 3674 19 15 47 66 1.75 A035 209 3734 3725 3711 3699 9 14 26 35 4.37 A036 295 3735 3723 3708 3681 12 15 42 54 2.56 A037 372 3740 3716 3697 3669 24 19 47 71 2.10 A038 304 3742 3721 3709 3686 21 12 35 56 1.33 A039 232 3738 3722 3711 3698 16 11 24 40 1.67 A040 404 3742 3720 3705 3664 22 15 56 78 1.65 A041 493 3739 3711 3695 3638 28 16 73 101 1.51 A042 261 3736 3721 3709 3687 15 12 34 49 2.56 A044 301 3741 3722 3710 3683 19 12 39 58 1.56 A045 453 3739 3714 3689 3647 25 25 67 92 2.64 A047 341 3735 3716 3699 3668 19 17 48 67 2.22 A048 270 3733 3720 3705 3682 13 15 38 51 3.15 A049 252 3737 3725 3711 3690 12 14 35 47 2.52 A050 288 3740 3723 3711 3685 17 12 38 55 2.02 A051 514 3738 3705 3691 3634 33 14 71 104 0.96 A052 276 3737 3723 3712 3687 14 11 36 50 1.95 A053 241 3738 3724 3715 3696 14 9 28 42 1.68 A054 294 3733 3716 3700 3679 17 16 37 54 2.12 A055 540 3737 3718 3687 3627 19 31 91 110 4.81 A056 566 3740 3711 3685 3624 29 26 87 116 2.34 A057 232 3723 3710 3701 3683 13 9 27 40 1.61 A058 360 3738 3723 3709 3669 15 14 54 69 3.55 A059 232 3736 3723 3711 3696 13 12 27 40 2.36 A060 197 3730 3719 3710 3698 11 9 21 32 2.13 A061 294 3734 3720 3707 3680 14 13 40 54 2.20 A062 439 3738 3718 3702 3651 20 16 67 87 2.96 A063 237 3738 3728 3715 3697 10 13 31 41 3.53 A064 285 3737 3719 3705 3685 18 14 34 52 1.89 A065 320 3740 3721 3703 3680 19 18 41 60 2.71 A066 186 3738 3726 3719 3707 12 7 19 31 1.36 A067 494 3740 3708 3689 3641 32 19 67 99 1.50 A068 286 3739 3725 3713 3686 14 12 39 53 1.89 A069 223 3734 3719 3714 3695 15 5 24 39 0.80 A070 354 3739 3716 3703 3671 23 13 45 68 1.40 A071 399 3738 3714 3695 3660 24 19 54 78 1.90 A072 463 3738 3712 3694 3646 26 18 66 92 1.71 A073 494 3738 3707 3685 3639 31 22 68 99 1.68 A074 286 3718 3700 3683 3665 18 17 35 53 2.17 A075 114 3741 3734 3730 3726 7 4 8 15 0.98 A076 385 3742 3718 3704 3665 24 14 53 77 1.39 A077 508 3740 3718 3694 3634 22 24 84 106 3.10 A078 296 3740 3724 3707 3684 16 17 40 56 2.34 A080 499 3741 3729 3706 3637 12 23 92 104 5.02 A081 550 3742 3710 3694 3626 32 16 84 116 1.57 A082 431 3742 3716 3696 3654 26 20 62 88 1.91 A083 296 3742 3720 3709 3686 22 11 34 56 1.16 A084 376 3742 3732 3715 3667 10 17 65 75 4.55 A085 342 3742 3727 3701 3675 15 26 52 67 5.07 A086 448 3742 3717 3700 3650 25 17 67 92 1.73 A087 431 3742 3715 3694 3654 27 21 61 88 1.84 A088 512 3737 3704 3681 3630 33 23 74 107 1.64 A089 292 3742 3723 3712 3687 19 11 36 55 1.24 A090 711 3742 3718 3680 3588 24 38 130 154 4.73 A091 393 3741 3724 3707 3659 17 17 65 82 3.80 A092 711 3740 3696 3657 3582 44 39 114 158 2.38 A093 243 3739 3730 3716 3693 9 14 37 46 3.73 A094 322 3741 3719 3709 3676 22 10 43 65 1.16 A095 490 3743 3710 3689 3638 33 21 72 105 1.51 A096 214 3739 3725 3717 3700 14 8 25 39 1.29 A097 256 3741 3721 3712 3692 20 9 29 49 1.14 A098 398 3742 3716 3695 3659 26 21 57 83 1.81 A099 289 3742 3722 3707 3685 20 15 37 57 1.61 A100 536 3741 3709 3685 3625 32 24 84 116 1.62 A101 269 3740 3727 3712 3690 13 15 37 50 2.94 A102 397 3740 3721 3712 3661 19 9 60 79 1.16 A103 495 3741 3715 3693 3640 26 22 75 101 1.96 A104 260 3730 3719 3705 3682 11 14 37 48 3.88 A105 393 3738 3725 3709 3660 13 16 65 78 2.64 A107 402 3740 3722 3701 3660 18 21 62 80 2.58 A108 198 3743 3732 3721 3709 11 11 23 34 2.61 A109 273 3740 3726 3711 3689 14 15 37 51 2.85 A110 499 3737 3719 3696 3635 18 23 84 102 3.76 A111 366 3739 3723 3701 3667 16 22 56 72 3.45 A112 614 3742 3714 3690 3614 28 24 100 128 2.03 A113 371 3737 3717 3701 3664 20 16 53 73 1.80 A114 388 3732 3711 3691 3655 21 20 56 77 2.13 A115 446 3742 3716 3697 3652 26 19 64 90 1.93 A116 230 3742 3727 3715 3698 15 12 29 44 1.62 A117 499 3739 3710 3687 3630 29 23 80 109 1.85 A118 230 3743 3729 3721 3699 14 8 30 44 1.29 A119 308 3742 3728 3716 3679 14 12 49 63 1.91 A120 250 3737 3722 3713 3688 15 9 34 49 1.28 A121 196 3740 3730 3720 3704 10 10 26 36 2.04 A122 404 3736 3713 3692 3650 23 21 63 86 2.06 A123 205 3742 3730 3720 3704 12 10 26 38 1.87 A124 213 3736 3721 3712 3696 15 9 25 40 1.40 A125 541 3719 3683 3668 3600 36 15 83 119 1.02 A126 177 3743 3735 3725 3714 8 10 21 29 3.53 A127 482 3741 3714 3698 3640 27 16 74 101 1.53 A128 300 3740 3723 3715 3682 17 8 41 58 1.13 A129 338 3744 3728 3715 3677 16 13 51 67 3.01 A130 410 3740 3715 3701 3656 25 14 59 84 1.67 A131 258 3738 3724 3710 3690 14 14 34 48 2.37 A132 381 3742 3720 3697 3665 22 23 55 77 3.66 A133 347 3742 3728 3705 3673 14 23 55 69 4.05 A134 376 3743 3723 3710 3667 20 13 56 76 2.65 A135 330 3741 3717 3702 3676 24 15 41 65 1.55 A136 414 3744 3725 3709 3659 19 16 66 85 2.24 A137 381 3739 3711 3693 3662 28 18 49 77 1.47 A138 487 3743 3712 3693 3641 31 19 71 102 1.66 A139 478 3742 3717 3702 3642 25 15 75 100 1.37 A140 482 3743 3710 3690 3642 33 20 68 101 1.38 A141 373 3739 3714 3701 3661 25 13 53 78 1.23 A142 197 3742 3729 3719 3706 13 10 23 36 1.90 A143 239 3739 3726 3710 3693 13 16 33 46 3.25 A144 460 3740 3709 3692 3641 31 17 68 99 1.32 A145 465 3739 3705 3686 3639 34 19 66 100 1.36 A146 347 3736 3718 3705 3664 18 13 54 72 1.68 A147 385 3742 3713 3698 3661 29 15 52 81 1.30 A148 448 3742 3714 3699 3646 28 15 68 96 1.43 A149 427 3744 3710 3692 3653 34 18 57 91 1.37 A150 607 3742 3701 3676 3608 41 25 93 134 1.40 A151 698 3737 3701 3664 3587 36 37 114 150 2.54 A152 293 3738 3716 3705 3683 22 11 33 55 1.29 A153 626 3729 3691 3670 3596 38 21 95 133 1.35 A154 412 3728 3706 3687 3645 22 19 61 83 2.04 A155 365 3739 3724 3694 3667 15 30 57 72 6.02 A156 250 3733 3717 3710 3688 16 7 29 45 1.12 A157 310 3737 3717 3702 3678 20 15 39 59 1.79 A158 263 3737 3723 3713 3689 14 10 34 48 1.60 A159 404 3733 3715 3696 3652 18 19 63 81 3.33 A160 412 3738 3717 3690 3655 21 27 62 83 3.35 A161 331 3740 3720 3706 3676 20 14 44 64 1.80 A162 421 3738 3722 3706 3653 16 16 69 85 3.37 A163 293 3738 3725 3714 3683 13 11 42 55 1.99 A164 267 3734 3720 3712 3685 14 8 35 49 1.40 A165 485 3736 3707 3688 3636 29 19 71 100 1.65 A166 486 3733 3703 3687 3631 30 16 72 102 1.28 A167 235 3734 3718 3711 3690 16 7 28 44 1.10 A168 317 3732 3722 3711 3669 10 11 53 63 2.29 A169 486 3726 3703 3693 3624 23 10 79 102 1.03 A170 304 3740 3717 3703 3680 23 14 37 60 1.45 A171 365 3740 3722 3698 3666 18 24 56 74 3.35 A172 261 3741 3727 3718 3691 14 9 36 50 1.30 A173 304 3740 3718 3704 3680 22 14 38 60 1.43 A174 412 3733 3707 3688 3648 26 19 59 85 1.65 A175 378 3719 3690 3671 3642 29 19 48 77 1.42 A176 337 3739 3724 3712 3671 15 12 53 68 1.69 A177 267 3740 3721 3710 3689 19 11 32 51 1.37 A178 408 3740 3716 3700 3655 24 16 61 85 1.63 A179 329 3738 3718 3705 3672 20 13 46 66 1.64 A180 250 3733 3719 3709 3686 14 10 33 47 1.53 A181 317 3739 3724 3702 3676 15 22 48 63 4.68 A182 354 3739 3716 3706 3667 23 10 49 72 1.02 A183 209 3726 3711 3703 3689 15 8 22 37 1.22 A184 375 3738 3717 3705 3661 21 12 56 77 1.40 A185 458 3736 3712 3689 3639 24 23 73 97 2.58 A186 545 3738 3721 3672 3620 17 49 101 118 7.32 A187 350 3739 3715 3701 3668 24 14 47 71 1.34 A188 300 3731 3717 3702 3672 14 15 45 59 2.34 A189 358 3731 3709 3689 3658 22 20 51 73 2.67 A190 230 3730 3718 3709 3688 12 9 30 42 2.12 A191 234 3738 3725 3717 3696 13 8 29 42 1.26 A192 261 3739 3722 3712 3691 17 10 31 48 1.41 A193 301 3742 3727 3710 3685 15 17 42 57 2.66 A194 257 3735 3721 3708 3688 14 13 33 47 2.17 A195 716 3739 3692 3660 3589 47 32 103 150 1.72 A196 337 3738 3719 3702 3673 19 17 46 65 2.19 A197 502 3739 3705 3691 3637 34 14 68 102 0.87 A198 208 3728 3718 3704 3692 10 14 26 36 2.85 A199 301 3741 3719 3705 3684 22 14 35 57 1.60 A200 274 3737 3718 3708 3686 19 10 32 51 1.25 A201 319 3741 3725 3713 3681 16 12 44 60 1.68 A202 243 3737 3723 3713 3694 14 10 29 43 1.83 A203 364 3740 3715 3704 3670 25 11 45 70 1.07 A204 239 3739 3724 3714 3697 15 10 27 42 1.56 A205 346 3740 3717 3704 3674 23 13 43 66 1.54 A207 319 3728 3711 3701 3668 17 10 43 60 1.37 A208 306 3737 3724 3707 3680 13 17 44 57 3.23 A209 319 3742 3725 3709 3682 17 16 43 60 2.09 A210 283 3740 3723 3714 3688 17 9 35 52 1.31 A211 515 3741 3712 3694 3637 29 18 75 104 1.49 A212 279 3740 3726 3716 3689 14 10 37 51 1.63 A213 448 3741 3724 3705 3652 17 19 72 89 2.62 A214 283 3739 3727 3712 3687 12 15 40 52 3.17 A215 359 3737 3715 3703 3668 22 12 47 69 1.34 A216 389 3741 3722 3707 3667 19 15 55 74 2.60 A217 560 3740 3716 3695 3630 24 21 86 110 2.09 A218 773 3738 3699 3665 3583 39 34 116 155 2.47 A219 238 3741 3729 3714 3699 12 15 30 42 2.74 A220 356 3741 3717 3704 3674 24 13 43 67 1.35 A222 233 3725 3713 3703 3684 12 10 29 41 1.74 A223 257 3741 3724 3717 3695 17 7 29 46 1.00 A224 351 3742 3718 3703 3676 24 15 42 66 1.55 A225 314 3741 3721 3709 3683 20 12 38 58 1.38
Though the sample ID's in Tables 14 and 15 range from A0001 to A225, gaps in sample numbers indicate occurrences where a sample was not able to be tested because they were beyond three standard deviations.
[0000] TABLE 16 R 2 mY INRw vs TPC INRm 0.9482 1.0506x TPC INRz 0.9482 1.0389x TPC INRn 0.9401 1.048x INRw vs INRm −0.0908 −0.0186x INRz −0.0966 −0.0144x INRn 0.0327 −0.0065x
The linear regression analysis expression y=m×+b, when solved for the slope, m, is expressed as (y−b)/x. This is biased, so the expression is y/x is when b is equal to zero. The comparison in Table 16, above, provides comparative data for mean y (mY) and mean x (mX) values, including the slope mY/mX. The use of the mY/mX is used to provide comparative results. The data in Table 16 is also represented on the Bland-Altman plots shown in FIGS. 8 , 9 , 10 and 11 . The statistical data and plots demonstrate that the INRn may replace prior WHO INR and provide results which are within the parameters of traditional therapeutic or reference ranges.
[0167] In accordance with one embodiment, the IBM-compatible computer 30 of FIG. 1 stores and manipulates these digital values corresponding to the clotting curve represented in FIG. 6 and the related data provided in Tables 14 and 15. According to a preferred embodiment, the computer may be programmed as follows:
(k) a sample of blood where the plasma is available, such as, for example, a sample of citrated blood, is obtained and placed in an appropriate container, the computer 30 , as well as the recorder 28 , sequentially records voltage values for a few seconds before injection of the reagent (thromboplastin calcium combined). As previously discussed, thromboplastin (tissue factor) is one of the factors in the human body that causes blood to clot. Prothrombin is another. Fibrinogen is yet another. Before injection of the thromboplastin, the output from the A/D converter 26 is relatively constant. When thromboplastin is injected into the plasma sample in the container, a significant and abrupt change occurs in the recorded voltage values of both the computer 30 and the recorder 28 . This abrupt change is recognized by both the recorder 28 and, more importantly, by the computer 30 which uses such recognition to establish T o . The computer 30 may be programmed so as to correlate the digital quantities of the A/D converter 26 to the analog output of the detector means photocell 10 which, in turn, is directly correlatable to the fibrinogen (FBG) concentration g/l of the sample of blood discussed herein and represented by the clotting curve shown in FIG. 6 ; (l) the computer 30 may be programmed to look for a digital quantity representative of a critical quantity F1, and when such occurs, record its instant time T 1 . (The time span between T o and T 1 is the prothromibin time (PT), and has an normal duration of about 12 seconds, but may be greater than 30 seconds); (m) following the detection of the quantity c 1 , the computer 30 may be programmed to detect for the acceleration of fibrinogen (FBG) to fibrin conversion. The computer 30 is programmed to detect the maximum acceleration quantity c MAP or c T2 as illustrated in FIG. 6 , and its corresponding time of occurrence t MAP , which is T2 in FIG. 6 . (d) The computer detects a quantity c EOT occurring at time t EOT . Typically, it is important that the rate of fibrin formation increase for at least 1.5 seconds following the occurrence of (T 1 ); the computer determines a theoretical end of test (TEOT) based on the determination of the zero order kinetic rate. The computer may be programmed to determine the zero order rate, which is expressed as a Line (L) in FIG. 6 . The TEOT may be determined by the corresponding time value (TEOT) along the line L which corresponds with the quantity CEOT (i.e., that corresponds with the value for T3); (e) The computer 30 is programmed to ascertain the value for the time to start (T 2 S) which corresponds with the time at which the simulated zero order kinetic rate begins. (f) Following the detection of the acceleration of fibrinogen conversion to detect the start time T 2 S, the computer 30 is programmed to detect for a deceleration of the fibrinogen conversion, wherein the fibrinogen concentration decreases from a predetermined quantity c MAP to a predetermined quantity c EOT having a value which is about equal but less than the first quantity c 1 . The computer is programmed to ascertain a first delta (IUTz), by determining the difference between the quantity c T2S and the quantity c EOT ; and a second delta (IUXz) by determining the difference between the quantity c T2S and the quantity c 2 (or c MAP). ; the computer also determines the value ZTM by determining the difference between the time T 2 (which is Tmap) and the time T 2 S; (g) the computer 30 manipulates the collected data of (a); (b); (c); (d), (e) and (f) above, to determine the new fibrinogen transfer rate (nFTR). The nFTR may be arrived at based on the principle that if a required amount (e.g., 0.05 g/l) of fibrinogen concentration c 1 is first necessary to detect a clot point (t 1 ); then when the fibrinogen concentration (c EOT ) becomes less than the required amount c 1 , which occurs at time (t EOT ), the fibrinogen end point has been reached. More particularly, the required fibrinogen concentration c 1 is the starting point of fibrinogen conversion of the clotting process and the less than required fibrinogen concentration c EOT is the end point of the fibrinogen conversion of the clotting process. (h) the duration of the fibrinogen conversion of the clotting process of the present invention is defined by the zero order time period between TEOT and T 2 S and is generally indicated in FIG. 6 as IUTz. The difference between the corresponding concentrations c T2S and cT2 is used to define a delta IUXz.
[0176] The computer now has the information needed to determine the TEOT, which is expressed by the following formula:
[0000] TEOT= T 2S+(ZTM/IUX*IUT) (12) The TEOT is determined and the data collected is manipulated by the computer 30 to determine a new INR, referred to as INRn:
[0000] INRn=(( T 1 +TEot)/2)*0.00535 *T 2 S (11) Using the multiplier MUL (which in this example, as discussed herein and according to expression 10 above, preferably is 0.00535).
[0179] The computer 30 may be used to manipulate and derive the quantities of expression (11) to determine a new INR (INRn) utilizing known programming routines and techniques. The data collected by a computer 30 may be used to manipulate and derive INRn of expression (11). Similarly, one skilled in the art, using known mathematical techniques may derive the theoretical end of test TEOT of expression (5), and using the TEOT value in expression (11), in turn, may determine the new INR, INRn of expression (12). In the INRn determination, the determination is based on the patient's own sample, and does not rely on the determination of normal prothrombin times for the reagent used (e.g., thromboplastin, innovin or the like). With the INRn determination method, no longer does the accuracy of the quantities determined depend, in whole or part, on the number of specimens used, that is, the number of stable (or presumed stable) patients.
[0180] The new anticoagulation therapy value (INRn) does not require an ISI value, as was previously used to determine anticoagulation therapy factors. The new anticoagulation therapy value INRn uses for its ascertainment the values extracted from the clotting curve (see FIG. 6 ), in particular T 2 S, Tmap, TEOT, c1, c T2S , ct2 and ceot. In determining the new INRn, the ISI is not required, nor is the MNPT, or the need to obtain and calculate the prothrombin times (PT's) for 20 presumed normal patients. In carrying out coagulation studies, the new anticoagulant therapy factor INRn may replace the INR traditionally used in anticoagulant therapy management (such as INR WHO and INRm). In addition, using the sample from the patient, the computer 30 has knowledge of the values obtained for the fibrinogen reaction, to ascertain the INRn.
[0181] It should now be appreciated that the present invention provides an apparatus and method for obtaining an new anticoagulant therapy value INRn without encountering the complications involved with obtaining the prior art quantities International Normalized Ratio (INR) and International Sensitivity Index (ISI).
[0182] The new International Normalized Ratio (INRn) preferably is a replacement for the International Normalized Ratio (INR) such as that of the WHO or the manufacturers of the clotting reagent that may provide an ISI for use with their particular clotting reagent. Existing medical literature, instrumentation, and methodologies are closely linked to the International Normalized Ratio (INR). The new INRn was compared for correlation with the INR by comparative testing, to INR quantities of INRw and INRm, even with the understanding that the INR determination may have an error of about +/−15%, at a 95% confidence interval, which needs to be taken into account to explain certain inconsistencies. The hereinbefore description of the new INRn does correlate at least as well as, and preferably better than, studies carried out using the traditional methods and determinations involving International Normalized Ratio (INR). For some comparisons, see the table above, and, in particular, Tables 11, 12 and 13.
[0183] While the invention has been described with reference to specific embodiments, the description is illustrative and is not to be construed as limiting the scope of the invention. The sample container used to contain the sample may comprise a vial, or cuvette, including, for example, the sample container disclosed in our U.S. Pat. No. 6,706,536. For example, although described in connection with body fluids of a human, the present invention has applicability to veterinary procedures, as well, where fluids are to be measured or analyzed. Various modifications and changes may occur to those skilled in the art without departing from the spirit and scope of the invention described herein and as defined by the appended claims. | 4y
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority of European Patent Application No. EP 13 004 629.5, filed Sep. 24, 2013, the content of which is incorporated herein in its entirety.
FIELD OF THE INVENTION
[0002] The invention relates to an aircraft boarding bridge or aircraft boarding stairs with a bellows attached to a head frame of the aircraft boarding bridge or stairs by way of a fastening device.
BACKGROUND OF THE INVENTION
[0003] Aircraft boarding stairs or aircraft boarding bridges are sufficiently known from the prior art. Aircraft boarding stairs and aircraft boarding bridges both have, at their front end facing the aircraft, a bellows, which is configured in such a manner that it covers the gap between the head side end of the aircraft boarding bridge or stairs and the outer hull of the aircraft in the area of the aircraft entrance.
[0004] The aircraft boarding bridge or stairs features a so-called head frame on its front side end. The folding bellows has a bellows frame at its end facing the aircraft boarding bridge or stairs, the head frame being connected to the bellows frame. This is usually done by attaching the bellows frame with the bellows to the head frame, e.g. by way of a screw clamp, driving corresponding bores through the head frame and bellows frame and subsequently connecting the bellows frame of the bellows with the head frame by means of rivets. This is very complicated, more specifically since the entire bellows is already hinged to the bellows frame. This means that the bellows is always behind a workman when drilling the holes and inserting the rivets.
SUMMARY OF THE INVENTION
[0005] Therefore, the problem underlying the invention is to solve this issue. More specifically, the problem is to provide a connection between the bellows and the aircraft boarding bridge or aircraft boarding stairs that is easily producible at low cost.
[0006] In order to solve the problem, the invention proposes that the fastening device should comprise means for providing a positive connection acting in at least two spatial directions, wherein the positive connection is fixable by way of an at least non-positive connecting member. A combination of a non-positive connection with a means for providing a positive connection makes it possible not only to provide a simple and cost-effective fastening device but also one that is quickly mountable and detachable without a destruction of the individual connection elements. In this regard, using such a fastening device has other advantages; these are more specifically that in order to transport an aircraft boarding bridge or stairs, the bellows and the aircraft boarding bridge or aircraft boarding stairs can be transported separately. This considerably facilitates the transport, since a fastening of the bellows to the aircraft boarding bridge or stairs can occur on site by way of the fastening device according to the invention. In addition, if a replacement part is needed, a replacement of the bellows is possible without difficulty. This means that the connection is detachable.
[0007] In detail, it is provided that the means comprise first and second connection elements that may be brought into a positive engagement with each other, wherein the first connection element is more specifically configured as a profile with an approximately C-shaped cross-section and the other second connection element is configured as a hook member. A hook member is a member that is able to at least partially engage behind the C-shaped connecting member along the better part of its length, or at least behind a part of the C-shaped profile serving as a connecting member. The hook member, configured in this regard as a strip, more specifically engages with the C-shaped profile with a clearance. A strip made of an elastomer, which presses the hook member onto the C-shaped profile, is provided as a non-positive connecting element for fixing the hook member to the C-shaped profile. This means that the hook member engaging with a clearance with the C-shaped profile is held in place by the elastic strip. In this regard, the strip, which is configured more specifically as a keder profile, can be characterized by a tapered end, in order to be able to drive this keder profile into the space between the hook member on the one hand and the C-shaped profile on the other hand.
[0008] In order to prevent the strip made of an elastomer from unintentionally disengaging itself from its fixing position, it is provided that the strip has a groove at least on one longitudinal side, which serves for a partial positive engagement around or behind the hook member and/or a protrusion of the C-shaped profile. In this regard, if the strip has at least one groove running along the strip, which is engaged either with the hook member or with the protrusion of the C-shaped profile, the strip made of an elastomer is no longer only an element that is able to provide a non-positive connection but the connection between the strip and the hook member and the C-shaped profile is also characterized by a positive-fit component. Such a strip is also referred to as a keder profile. The strip is made of an elastomer and which holds the hook member in an engagement with the C-shaped profile by means of a positive connection but also, if applicable, by means of a non-positive component.
[0009] Alternately to the previously described embodiment, an embodiment is also conceivable in which a C-shaped profile is also provided as a first connection element, wherein the C-shaped profile receives a strip-like hook member made of an elastomer. Here, the strip-like hook member has two grooves, with which the protrusions of the C-shaped profile, which respectively point toward each other, engage. In order to be able to drive the hook member made of an elastomer into the C-shaped profile, the hook member has a recess, which serves to receive the keder strip, in the area of the two protrusions of the C-shaped profile pointing toward each other. This means that the hook strip, which also consists of an elastomer, is held in position by the keder strip consisting of an elastomer.
[0010] Another embodiment is characterized in that the C-shaped profile has in particular two legs, which are connected to each other by a web, wherein the hook member is grasped by the legs. The C-shaped profile has a leg shaped as a shoe at one of its ends, wherein the hook member has a foot in the area of the shoe, which is mounted in the leg configured as a shoe. The leg has a protrusion, which extends approximately parallel to the foot of the hook member. Between the foot of the hook member and the protrusion, there is a gap, which serves to receive the strip made of an elastomer. In order to prevent the strip made of an elastomer from getting out of the shoe, the hook member has a projection in the area of the foot.
[0011] In addition, it is more specifically provided that the first connection element, more specifically the C-shaped profile, is fixed, e.g. screwed, to the head frame of the aircraft boarding bridge or aircraft boarding stairs. In order to prevent humidity from entering between the first connection element on the one hand and the head frame on the other hand into the inside of the aircraft boarding bridge or stairs, the first connection element is advantageously sealed against the head frame, for example by means of silicone.
[0012] Any number of connection types, e.g. clamping, gluing, screwing, etc. are known for connecting the hook member to the bellows.
[0013] In order to save weight, the C-shaped profile is advantageously made of aluminium. In different variants, this also applies to the hook member.
[0014] In the following, the invention is exemplarily described in more detail based on the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows a first embodiment of a fastening device in accordance with the present invention;
[0016] FIG. 2 shows a second embodiment of a fastening device in accordance with the present invention;
[0017] FIG. 3 shows a third embodiment of a fastening device, wherein the hook member is made of an elastomer in accordance with the present invention; and
[0018] FIG. 4 shows a fourth embodiment of a fastening device in accordance with the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] The aircraft boarding bridge or stairs is schematically hinted at and labelled 1 . The aircraft boarding bridge or stairs 1 has a head frame 3 , which is disposed at the front of the aircraft boarding bridge or stairs 1 in a U-shaped circumferential manner. The C-shaped profile 7 , 70 , which is more specifically screwed to the head frame 3 , is also disposed in a U-shaped circumferential manner on the head frame 3 . A sealing compound, for example made of silicone, is located between the C-shaped profile 7 , 70 and the head frame 3 , in order to prevent humidity from getting into the inside of the aircraft boarding bridge or stairs.
[0020] The C-shaped profile 7 , 70 has a web 8 ; 80 , which serves to implement a screw connection with the head frame 3 . The web 8 ; 80 features two legs 9 ; 90 , 91 disposed at both ends in a U-shaped manner, wherein the two legs have first and second protrusions 10 , 11 ; 100 , 111 pointing toward each other. This results in a profile with a C-shaped cross-section.
[0021] In order to be received by the C-shaped profile 7 , the hook member labelled 20 in FIG. 1 has a U-shaped claw 22 , wherein the claw 22 serves to hook the strip-shaped hook member 20 into the first protrusion 10 of the C-shaped profile 7 . The strip 30 made of an elastomer, which may also be referred to as a keder, is provided in order to fix this hook member 20 with the claw 22 in the position shown in the figure. At one side of its longitudinal edge, the keder or strip 30 has a groove 33 , which captures the second protrusion 11 of the C-shaped profile 7 . The nose 35 , which engages behind the hook member 20 , is provided in order to reliably prevent the strip 30 from unintentionally slipping out.
[0022] Here, it can be seen that the hook member 20 is positively received by the C-shaped profile 7 in two spatial directions X and Y. The hook member 20 first rests with a clearance in the C-shaped profile 7 , wherein the clearance is defined by a free space 40 between the hook member 20 and the free end of the second protrusion 11 . The strip 30 is driven into this free space 40 , so that the hook member 20 is ultimately held in the position shown in FIG. 1 .
[0023] The embodiment according to FIG. 2 differs from that in FIG. 1 in that the strip-shaped hook member 120 is merely L-shaped and does not have a U-shaped claw like the hook member 20 . In the embodiment according to FIG. 2 , the hook member 120 is also held in position by the strip 30 . The strip 30 here also features a groove 33 to be received by the second protrusion 11 of the C-shaped profile 7 .
[0024] The embodiment according to FIG. 3 features a C-shaped profile 7 , which is configured in the same manner as in FIG. 2 . Here however, the C-shaped profile 7 receives a strip-shaped hook member 200 , wherein the hook member 200 is made of an elastomer. In order to receive the two protrusions 10 and 11 of the C-shaped profile 7 pointing toward each other, the hook member 200 has two grooves 240 , in which the protrusions 10 and 11 of the C-shaped profile engage, as can be gathered from FIG. 3 . In the area of the two grooves 240 , there is a recess 210 , which serves to receive the strip 230 made of an elastomer material. This means that, in principle, the strip 230 forms a keder strip.
[0025] In the embodiment according to FIG. 4 , the C-shaped profile 70 features two legs 90 , 91 connected by the web 80 , which, at their ends, respectively have protrusions 100 , 111 pointing toward each other. The leg 91 is here configured in the manner of a shoe 95 . In the area of the shoe 95 , the strip-like hook member labelled 300 has a foot 310 , which is spaced apart from the protrusion 111 of the shoe 95 . The strip 330 made of an elastomer is introduced into the space formed by the gap, wherein, in order to prevent the strip 330 from getting out the shoe 95 under a load, the hook member 300 has a projection 315 in the area of the foot 310 .
[0026] The hook member 20 , 120 , 200 , 300 additionally features the bellows 50 at one free end.
LIST OF REFERENCE NUMBERS
[0000]
1 aircraft boarding bridge or stairs
3 head frame
7 C-shaped profile
8 web
9 leg
10 first protrusion
11 second protrusion
20 hook member
22 claw
30 strip (made of an elastomer)
33 groove
35 nose
40 free space between the second protrusion and the hook member
50 bellows
70 C-shaped profile
80 web
90 leg
91 leg
95 shoe
100 first protrusion
111 second protrusion
120 hook member
200 hook member (made of an elastomer)
210 recess in the hook member
230 strip (made of an elastomer)
240 grooves
300 hook member
310 foot
315 projection
330 strip (made of an elastomer) | 4y
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RELATED APPLICATIONS
[0001] This application is a continuation application of U.S. patent application Ser. No. 10/320,345 filed 16 Dec. 2002, now U.S. Pat. No. 6,735,948 issued 18 May 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a process and system for converting thermal energy from moderately low temperature sources, especially from geothermal fluids, into mechanical and/or electrical energy.
[0004] More particularly, the present invention relates to a process and system for converting thermal energy from moderately low temperature sources, especially from geothermal fluids, into mechanical and/or electrical energy including high pressure and low pressure circuits, where all partially condensed liquid from the high pressure circuit is combined with the stream coming from the low pressure circuit forming a lean stream which can be condensed at a pressure lower than a pressure required to condense the stream had its composition not been made lean or its concentration lowered.
[0005] 2. Description of the Related Art
[0006] Prior art methods and systems for converting heat into useful energy at well documented in the art. In fact, many such methods and systems have been invented and patented by the inventor. These prior art systems include U.S. Pat. Nos. 4,346,561, 4,489,563, 4,548,043, 4,586,340, 4,604,867,4,674,285,4,732,005,4,763,480,4,899,545,4,982,568,5,029,444,5,095,708,5,440,882, 5,450,821, 5,572,871, 5,588,298, 5,603,218, 5,649,426, 5,822,990, 5,950,433 and 5,593,918; Foreign References:7-9481 JP and Journal References: NEDO Brochure, “ECO-Energy City Project”, 1994 and NEDO Report published 1996,pp.4-6,4-7,4-43,4-63,4-53, incorporated herein by reference.
[0007] Although all of these prior art systems and methods relate to the conversion of thermal energy into other more useful forms of energy from moderately low temperature sources, all suffer from certain inefficiencies. Thus, there is a need in the art for an improved system and method for converting thermal energy from moderately low temperature sources to more useful forms of energy, especially for converting geothermal energy from moderately low temperature geothermal streams into more useful forms of energy.
SUMMARY OF THE INVENTION
[0008] The present invention also provides a method and a systems for implementing a thermodynamic cycle including a higher pressure and a lower pressure circuit, where one novel feature of the system or method involves combining a separated spent liquid stream from the higher pressure circuit with a spent stream from the lower pressure circuit prior to the condensing steps. Because the separated spent liquid stream has a leaner composition than the initial fully condensed working fluid, the stream can be condensed at a lower pressure and then combined with the separated vapor from the higher pressure circuit to form the fully condensed initial working fluid liquid stream.
[0009] The present invention provides a method for implementing a thermodynamic cycle to convert a greater amount of thermal energy from an external heat source into useful electric and/or mechanical energy, where the method includes the steps of transforming thermal energy from a fully vaporized higher pressure stream into a usable energy form to product a spent higher pressure stream and transforming thermal energy from a vaporized lower pressure stream into a usable energy form to product a spent lower pressure stream. The method further includes the steps of heating a higher pressure liquid stream with a portion of a spent higher pressure stream to form a heated higher pressure stream and a first partially condensed spent higher pressure stream and heating a lower pressure stream with a remaining portion of the spent higher pressure stream to form a heated lower pressure stream and a second partially condensed spent higher pressure stream. The method also includes the steps of heating the heated higher pressure liquid stream with a portion of an external heat source stream to form a hotter higher pressure stream and a first spent external heat source stream and heating the heated lower pressure stream with a remaining portion of the external hear source stream to form a vaporized lower pressure stream and a second spent external heat source stream. The method also includes the steps of heating the hotter higher pressure stream with the external heat source stream to form the fully vaporized higher pressure stream, separating the partially condensed spent higher pressure streams into a spent higher pressure liquid stream and a spent higher pressure vapor stream, mixing the spent higher pressure liquid stream with the spent lower pressure stream at the pressure of the spent lower pressure stream to form a combined spent lower pressure stream and condensing the combined spent lower pressure stream with an external cooling stream to form a condensed spent lower pressure stream. The method further includes the steps of mixing the condensed spent lower pressure stream with the spent higher pressure vapor stream to form a combined partially condensed spent higher pressure stream at the pressure of the spent higher pressure vapor stream, condensing the combined partially condensed spent high pressure stream to form a fully condensed liquid stream; and forming the higher pressure stream and the lower pressure stream from a fully condensed liquid stream.
[0010] The present invention also provides a method for improved energy conversion of heat from external heat sources including the steps of forming a higher pressure working fluid stream and a lower pressure working fluid stream from a fully condensed working fluid stream. After the two streams are formed, the higher pressure working fluid stream is heated with a portion of a spent higher pressure working fluid stream to form a heated higher pressure working fluid stream and a first partially condensed spent higher pressure working fluid stream, the heated higher pressure working fluid stream is heated with a portion of a partially cooled external source stream to form a hotter higher pressure working fluid stream and a first spent external source stream and finally the hotter higher pressure working fluid stream is vaporized with an external source stream to form a fully vaporized higher pressure working fluid stream and the partially cooled external source stream. Once fully vaporized, the thermal energy from the fully vaporized higher pressure working fluid stream is transformed into a usable energy form to product a spent higher pressure working fluid stream. While the higher pressure stream is being processed, the lower pressure working fluid stream is heated with a remaining portion of the spent higher pressure working fluid stream to form a heated lower pressure working fluid stream and a second partially condensed spent higher pressure working fluid stream, and the heated lower pressure working fluid stream is heated with a remaining portion of the partially cooled external source stream to form a vaporized lower pressure working fluid stream and a second spent external source stream. Once vaporized, the thermal energy from the vaporized lower pressure working fluid stream is transformed into a usable energy form to product a spent lower pressure working fluid stream. The first and second partially condensed, spent higher pressure working fluid streams are separated into a spent higher pressure liquid working fluid stream and a higher pressure vapor working fluid stream and the spent lower pressure working fluid stream is mixed with the spent higher pressure liquid working fluid stream at the lower pressure to form a combined spent lower pressure working fluid stream. The combined spent lower pressure working fluid stream is cooled with an external cooling stream to form a condensed lower pressure working fluid stream, while the condensed lower pressure working fluid stream and the spent higher pressure vapor working fluid stream at a pressure of the spent higher pressure vapor working fluid stream is cooled with another external cooling stream to form the fully condensed working fluid stream.
[0011] The present invention also provides an apparatus for improved conversion of thermal energy into mechanical and/or electrical energy including a first means for expanding a fully vaporized higher pressure stream, transferring its energy into usable form and producing a higher pressure spent stream and a second means for expanding a fully vaporized lower pressure stream, transferring its energy into usable form and producing a lower pressure spent stream. The apparatus also includes a first heat exchanger adapted to condense a combined lower pressure spent stream with an external coolant stream to form a condensed combined lower pressure spent stream, a first pump adapted to increase a pressure of the condensed combined lower pressure spent stream to form an increased pressure, condensed combined lower pressure spent stream, and a first stream mixer adapted to combine the increased pressure, condensed combined lower pressure spent stream and a vapor higher pressures spent stream to form a partially condensed stream. The apparatus also includes a second heat exchanger adapted to condense the partially condensed stream with an external coolant stream to form a fully condensed liquid stream and a first stream splitter adapted to form first and second portions of the fully condensed liquid stream. The apparatus also includes a second pump adapted to increase a pressure the first portion of the fully condensed liquid stream to form a higher pressure liquid stream and a third pump adapted to increase a pressure the second portion of the fully condensed liquid stream to form a lower pressure liquid stream. The apparatus also includes a third heat exchanger adapted to heat the higher pressure liquid stream with a first portion of a higher pressure spent stream to form a heated higher pressure liquid stream and a first partially condensed higher pressure spent stream and a fourth heat exchanger adapted to heat the lower pressure liquid stream with a remaining portion of the higher pressure spent stream to form a heated lower pressure liquid stream and a second partially condensed higher pressure spent stream. The apparatus also includes a fifth heat exchanger adapted to heat the heated higher pressure liquid stream with a first portion of a partially cooled external heat source stream to form a hotter higher pressure liquid stream and a first spent external heat source stream and a sixth heat exchanger adapted to heat the heated lower pressure liquid stream with a remaining portion of the partially cooled external heat source stream to form a vaporized lower pressure stream and a second spent external heat source stream. The apparatus also includes a seventh heat exchanger adapted to vaporize the hotter higher pressure liquid stream with an external heat source stream mixer to form the fully vaporized higher pressure stream and the partially cooled external heat source stream. The apparatus also includes a second stream splitter adapted to form the first and second portions of the higher pressure spent stream, a third stream splitter adapted to form the first and second portions of the cooled external heat source stream, a second stream mixer adapted to combine the first and second partially condensed higher pressure spent stream to form a combined partially condensed higher pressure spent stream, a gravity separator adapted to separate combined partially condensed higher pressure spent stream into a lean liquid stream and a rich vapor stream, a throttle valve adapted to change the pressure of the lean liquid stream to a pressure of the lower pressure spent stream and a third stream mixer adapted to combine the pressure adjusted lean liquid stream with the lower pressure spent stream. The apparatus is capable of achieving improved efficiency due to the mixing of the lean liquid stream with the spent lower pressure stream so that the combined stream can be condensed at a lower pressure than a non-lean stream.
DESCRIPTION OF THE DRAWINGS
[0012] The invention can be better understood with reference to the following detailed description together with the appended illustrative drawings in which like elements are numbered the same:
[0013] FIG. 1A depicts a preferred embodiment of an apparatus for implementing the novel thermodynamic method and system of this invention; and
[0014] FIG. 1B depicts another preferred embodiment of an apparatus for implementing the novel thermodynamic method and system of this invention.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The inventors have found a novel thermodynamical cycle (system and process) can be implements using a working fluid including a mixture of at least two components. The preferred working fluid being a water-ammonia mixture, though other mixtures, such as mixtures of hydrocarbons and/or freons can be used with practically the same results. The systems and methods of this invention are more efficient for converting heat from relatively low temperature fluid such as geothermal source fluids into a more useful form of energy. The systems use a multi-component basic working fluid to extract energy from one or more (at least one) geothermal source streams in one or more (at least one) heat exchangers or heat exchanges zones. The heat exchanged basic working fluid then transfers its gained thermal energy to one or more (at least one) turbines (or other system for extracting thermal energy from a vapor stream and converting the thermal energy into mechanical and/or electrical energy) and the turbines convert the gained thermal energy into mechanical energy and/or electrical energy. The systems also include pumps to increase the pressure of the basic working fluid at certain points in the systems and one or more (at least one) heat exchangers which bring the basic working fluid in heat exchange relationships with one or more (at least one) cool streams. One novel feature of the systems and methods of this invention, and one of the features that increases the efficiency of the systems, is the result of using a two circuit design having a higher pressure circuit and a lower pressure circuit and where a stream comprising spent liquid separated for spent vapor from the higher pressure circuit is combined with a stream comprising the spent lower pressure stream at the pressure of the spent lower pressure stream prior to condensation to from the initial fully condensed liquid stream and where the combined stream is leaner than the initial fully condensed liquid stream.
[0016] The working fluid used in the systems of this inventions preferably is a multi-component fluid that comprises a lower boiling point component fluid—the low-boiling component—and a higher boiling point component—the high-boiling component. Preferred working fluids include an ammonia-water mixture, a mixture of two or more hydrocarbons, a mixture of two or more freon, a mixture of hydrocarbons and freon, or the like. In general, the fluid can comprise mixtures of any number of compounds with favorable thermodynamic characteristics and solubility. In a particularly preferred embodiment, the fluid comprises a mixture of water and ammonia.
[0017] Referring now to FIG. 1A , a flow diagram, generally 100 , is shown that illustrates a preferred embodiment a system and method of energy conversion of this invention and will be described in terms of its components and its operation.
[0018] A condensed working fluid having parameters as at a point 1 is divided into two sub streams having parameters as at points 2 and 27 , respectively. The stream having the parameters of the point 2 enters pump P 1 , where the stream is pumped to a desired high pressure and obtains parameters as at a point 3 . Thereafter, the stream having the parameters of the point 3 passes through a first heat exchanger HE 3 , where it is heated in counter flow with a returning, condensing stream in a condensing step defined by points 9 - 12 (described below), and obtains parameters as at a point 4 . The state of the working fluid at the point 4 corresponds to a sub cooled liquid. Thereafter, the stream having the parameters of the point 4 passes through a second heat exchanger HE2 where it is further heated by an external heat source stream (e.g., a geothermal brine stream) and obtains parameters as at a point 5 , where the parameters at the point 5 correspond to a saturated liquid.
[0019] Next, the stream having the parameters of the point 5 passes through a third heat exchanger HE 1 in counter flow with the external heat source stream (the geothermal brine stream), where the stream of working liquid is fully evaporated and slightly superheated to obtain parameters as at a point 6 . The vapor stream having the parameters of the point 6 passes through a first high pressure turbine T 1 where the vapor stream expands, producing mechanical work, and obtains parameters as at a point 7 . The stream having the parameters of the point 7 is then divided into two sub streams having parameters as at points 8 and 9 , respectively. The stream having the parameters of the point 9 passes through the first heat exchanger HE 3 where it is cooled and condensed providing heat for the 3 - 4 heating step (described above) and obtains parameters as at a point 12 .
[0020] The stream having the parameters of the point 8 is then mixed with a stream having parameters as at a point 20 (described below) and obtains parameters as at a point 10 . Thereafter, the stream having the parameters of the point 10 passes through a fourth heat exchanger HE 6 , where it is cooled and condensed, releasing heat for a heating step 28 - 19 (described below), and obtains parameters as at a point 11 . Thereafter, streams having the parameters of the points 11 and 12 , respectively, are combined forming a stream the parameters of the point 13 enters a gravity separator S 1 , where it is separated into a rich vapor having parameters as at a point 14 and into a lean liquid having parameters as at a point 15 . The term a rich vapor stream means that the vapor has a higher concentration of the light boiling component than the original basic working fluid as at the point 1 , while the lean liquid stream means that the liquid has a lower concentration of the light boiling component than the original basic working fluid as at the point 1 .
[0021] The sub-stream of fully condensed working fluid having the parameters of the point 27 (as described above) enters into a second pump P 2 , where it is pumped to a desired elevated pressure and obtains parameters as at a point 28 . The pressure at point 28 is substantially lower than the pressure at the point 3 . The stream having the parameters of the point 28 then passes through the fourth heat exchanger HE 6 where it is heated by heat released in the process step 10 - 11 (described above) and obtains parameters as at a point 19 . Thereafter, the stream having the parameters as at the point 19 passes through a fifth heat exchanger HE 5 , where it is further heated and evaporated by the external heat source sub-stream (e.g., the geothermal brine stream) and obtains parameters as at point a 18 . Usually working fluid having the parameters as at the point 18 is not fully vaporized. A pressure of the working fluid in the process step 19 - 18 is substantially lower than the pressure of the working fluid in the process step 5 - 6 (described above). Therefore, the stream in the process step 19 - 18 starts to boil at a substantially lower temperature than the stream in the process step 5 - 6 . This allows the use of geothermal brine stream to heat the working fluid in the process step 5 - 6 and thereafter to use a portion of the same brine stream having a lower temperature, to provide heat for the process step 19 - 18 .
[0022] The geothermal brine stream, which is the heat source for a preferred use of the system of this invention, has initial parameters as at a point 30 . The brine stream having the parameters of the point 30 initially passes though the third heat exchanger HE 1 , providing heat for the process step 5 - 6 and obtains parameters as at a point 31 . Thereafter, the brine stream having the parameters of the point 31 is divided into two brine sub streams having parameters as at points 32 and 34 , respectively. The stream having the parameters of the point 32 passes through the second heat exchanger HE 2 providing heat for the process step 4 - 5 , and obtains parameters as at a point 33 . Meanwhile, the stream having the parameters of the point 34 passes through the fifth heat exchanger HE 5 , providing heat for the process step 19 - 18 , and obtains parameters as at a point 35 (described above). Thereafter, the cooled brine sub streams having the parameters of the points 33 and 35 are combined, forming a spent brine stream having parameters as at a point 36 , at which point the brine stream is removed from the system.
[0023] The stream of working fluid having the parameters of the point 18 (described above) enters a second gravity separator S 2 , where it is separated into a rich vapor stream having parameters as at a point 21 (i.e., rich means a higher concentration of the low boiling component—ammonia in water-ammonia fluids) and a relatively lean liquid stream having parameters as at a point 16 (i.e., rich means a lower concentration of the low boiling component—ammonia in water-ammonia fluids). The liquid stream having the parameters of the point 16 passes through a second throttle valve TV 2 , where its pressure is reduced to a pressure equal to the pressure of the stream having the parameters of the point 8 , and obtains parameters as at a point 20 . The stream having the parameters of the point 20 is combined with the stream having the parameters of the point 8 forming a combined stream having parameters of the point 10 (described above). The stream having the parameters of the point 20 is substantially leaner (i.e., lower concentration of low boiling component) than the stream having the parameters of the point 8 , and therefore, the combined stream having the parameters of the points 10 and 11 is leaner than the stream having the parameters of the point 8 . The stream having the parameters of the point 11 , is then combined with the stream having the parameters of the point 12 , forming a stream having parameters as at a point 13 , which is likewise leaner than the streams having the parameters of the points 8 and 9 .
[0024] The vapor stream having the parameters of the point 21 passes though a low pressure turbine T 2 , where the vapor stream having the parameters of the point 21 expands producing mechanical work and obtains parameters as at a point 22 . Meanwhile, the liquid stream having the parameters of the point 15 (described above) passes through a second throttle value TV 1 , where its pressure is reduced to a pressure equal to the pressure of the stream having the parameters of the point 22 , and obtains parameters as at a point 17 . Thereafter, the stream having the parameters of the point 17 is combined with the stream having the parameters of the point 22 forming a stream with parameters as at a point 23 . The stream having the parameters of the point 23 is formed by combining the lean liquid stream having the parameters of the point 15 coming from the separator S 1 with the turbine exhaust stream having the parameters of the point 22 coming from the turbine T 2 . As a result, the concentration of the low boiling component in the stream having the parameters of the point 23 is substantially lower than the concentration of the low boiling component in the working fluid stream having the parameters of the point 1 . This allows the stream having the parameters of the point 23 to be condensed at a lower pressure than the pressure of the stream having the parameters of the point 1 , increasing the power output from the turbine T 2 .
[0025] The stream having the parameters of the point 23 passes through an air (or water cooled) condenser or sixth heat exchanger HE 7 , where the stream having the parameters of the point 23 is fully condensed and obtains parameters as at a point 24 . The stream having the parameters of the point 24 , where the parameters correspond to a saturated liquid, enters pump P 3 where its pressure is increased to a pressure equal to the pressure of the stream having parameter of the point 14 , and obtains parameters as at a point 25 . Thereafter the streams having the parameters of the points 14 and 25 are combined forming a stream having parameters as at a point 26 . The composition of working fluid at the point 26 is the same as the composition of the working fluid at the point 1 . The stream having the parameters of the point 26 then passes though an air or water cooled condenser or a seventh heat exchanger HE 4 where it is fully condensed, obtaining the stream having the parameters of the point 1 . This preferred embodiment is, therefore, a closed cycle.
[0026] The parameters of all points of the proposed system are presented in Table 1.
TABLE 1 Parameter of Points in the Embodiment of FIG. 1A Point Concentration Temperature Pressure Enthalpy Weight No. X T (° F.) P (psia) h (btu/lb) (g/g6) Parameters of Working Fluid Streams 1 0.95 80.0 145.2535 36.7479 1.4169 2 0.95 80.0 145.2535 36.7479 1.0 3 0.95 82.6617 855.0 40.8130 1.0 4 0.95 145.0 845.0 113.7445 1.0 5 0.95 211.1676 835.0 200.6857 1.0 6 0.95 296.0 820.0 653.1787 1.0 7 0.95 152.8503 150.0 561.9714 1.0 8 0.95 152.8503 150.0 561.9714 0.175 9 0.95 152.8503 150.0 561.9714 0.825 10 0.8847 147.3266 150.0 476.1683 0.2154 11 0:8847 113.2951− 148.0 392.8725 0.2154 12 0.95 102.6927 148.0 473.5696 0.825 13 0.9365 105.6343 148.0 456.8624 1.0404 14 0.9989 105.6343 148.0 572.4092 0.83274 15 0.68629 105.6343 148.0 −6.4813 0.20766 16 0.60227 211.1676 465.0 104.7724 0.04043 17 0.68629 105.5611 132.2 −6.4813 0.20766 18 0.95 211.1676 465.0 559.5074 0.4169 19 0.95 118.4247 475.0 81.7763 0.4169 20 0.60227 139.2362 150.0 104.7727 0.04043 21 0.98735 211.1676 465.0 608.3474 0.37647 22 0.98735 96.1707 132.2 545.6323 0.37647 23 0.88030 98.6711 132.2 349.3722 0.5841 24 0.88030 78.0 130.1772 11.9150 0.5841 25 0.88030 78.1332 148.0 12.0976 0.5841 26 0.95 85.9850 148.0 341.4032 1.4169 27 0.95 80.0 145.2535 36.7479 0.4169 28 0.95 81.3188 485.0 38.7398 0.4169 29 0.95 161.1303 470.0 133.9673 0.4169 Parameters of Geothermal Source Stream 30 brine 305.0 273.0 5.0938 31 brine 216.168 184.168 5.0938 32 brine 216.168 184.168 1.5479 33 brine 160.0 128.0 1.5479 34 brine 216.168 184.168 3.5459 35 brine 160.0 128.0 3.5459 36 brine 160.0 128.0 5.0938 37 brine 166.1303 134.1303 3.5459 Parameters of Air Cooling Stream 40 air 60.0 6.7330 40.9713 41 air 80.0 11.5439 40.9713 42 air 60.0 6.7330 119.6414 43 air 75.0 10.3410 119.6414
[0027] Term concentration is defined as the ratio of the number of pounds of the low boiling component are each pound of working fluid. Thus, for an ammonia-water working fluid, a concentration of 0 . 95 means that working fluid comprises 0.95 lbs of ammonia and 0.5 lbs of water. The term weight represents that number of pounds of material passing through a given point relative to the number of pounds of material passing through the point 6 or the first part of the high temperature circuit defined by points 2 - 7 .
[0028] The system of this invention comprises two circuits; one circuit is a high pressure circuit and the other circuit is a lower pressure circuit. The use of two circuits having different pressures makes it possible to utilize heat from the geothermal brine stream for heating the stream of the working fluid in the high pressure circuit, and heat from a portion of a cooled or lower temperature geothermal brine stream for heating the stream of the working fluid in the lower pressure circuit. Unlike known two-pressure circuit systems, in the systems of this invention, the liquid produced after the partial condensation of the spent returning stream from the high pressure circuit (i.e., the stream having the parameters of the point 15 ) is added to the returning stream from the low pressure circuit. Thus the concentration of the returning stream from the low pressure circuit is substantially lowered which in its turn allows this returning stream to be condensed at a pressure lower than the pressure at which it would be condensed if its composition had not been lowered. This results in an increased power output And efficiency of the whole system. The summary of the performance of the entire system is presented in Table 2.
TABLE 2 Performance Summary Heat Input btu 738.6010 Heat Rejection btu 628.7749 Σ Turbine enthalpy drops btu 114.8177 Turbines work btu 111.9511 Feed pumps work btu 5.0022 Air fans work btu 9.10667 Network btu 97.8422 Net thermal efficiency % 13.25 Second Law efficiency % 57.24 Specific brine consumption lb/btu 0.0521 Specific Power output btu/lb 19.2081
[0029] The most efficient system previously developed for the same application is described in U.S. Pat. No. 4,982,568. A comparison of the performance of that system and the system of this invention is presented in table 3. As shown in table 3, the system of this invention out performs the prior art by about 18.83%.
TABLE 3 Comparison of System Performance System of U.S. Current Pat. No. System Characteristics System 4982568 Ratio Net Thermal Efficiency (%) 13.25 11.15 1.1883 Specific Power Output (btu/lb. of brine) 19.2081 16.1716 1.1878 Heat Rejection per btu of Net Output (btu/ 6.4264 7.8257 0.8212 btu)
[0030] Referring now to FIG. 1B , a modified system of this invention is shown to include a fourth pump P 4 which is used to increase the pressure of a portion of the stream having the parameters of the point 25 which is combined with the lower pressure liquid stream having the parameter of the point 28 .
[0031] It should be recognized by persons of ordinary skill in the art that the apparatus of this inventions also includes stream mixer valves and stream splitter valves which are designed to combine stream and split streams, respectively. In the system of FIG. 1A , the separator S 2 may not be need if the composition of the working fluid is adjusted so that the heated lower pressure stream is fully vaporized in the heat exchanger HE 5 , which requires a fluid having a concentration of about 0.965 or higher.
[0032] All references cited herein are incorporated by reference. While this invention has been described fully and completely, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. Although the invention has been disclosed with reference to its preferred embodiments, from reading this description those of skill in the art may appreciate changes and modification that may be made which do not depart from the scope and spirit of the invention as described above and claimed hereafter. | 4y
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FIELD OF THE INVENTION
This invention relates to a filtered ventilating system for a cooking unit and more particularly to such a system providing for cleaning of ventilating system parts.
BACKGROUND OF THE INVENTION
It is conventional practice in restaurants, and the like to employ ventilating hoods above cook tops, deep fat fryers, and other cooking units and by use of fans to draw heated cooking vapors, often including volatilized grease, out of the cooking area through the hood and a communicating exhaust stack. In the absence of grease filters in the hood, a portion of the grease particles and the like entrained in the air captured by the hood pass through the exhaust stack to form undesirable environmental contamination. A remaining portion of the volatilized grease entrained in the airstream contacts and tends to condense on the cooler surfaces inside the hood and exhaust stack, eventually forming an inflammable material which, being close to the heat of the cooking unit, may create a potential fire hazard. To reduce the quantity of volatilized grease available passing to the outside atmosphere and condensing on the inner stack and hood surfaces, cooktop hoods are frequently provided with grease filters. Effective grease filters eliminate much of the environmental contamination and greatly slow grease buildup, by entrapment of substantial portions of the entrained volatilized greases and the like in the grease filter.
Condensed grease and the like will relatively quickly build up on the surfaces of the grease filter, and to a lesser extent may gradually build up on the interior surfaces of the hood and stack beyond the filter. If this buildup is allowed to continue, the filter will gradually clog and loose filtering efficiency and the grease buildup in stack and filter may eventually be a fire hazard. Unfortunately, it is messy and time consuming to attempt to clean the interoir surfaces of the hood and exhaust stack, where access thereto is obtainable, and for that matter even to clean the grease filter.
Prior attempts of which I am aware, to deal with this problem, have been fragmentary at best.
For example, U.S. Pat. No. 3,805,685 (Carnes) provides fixed wash liquid pipes within the hood, disposed on opposite sides of a filter shielded from the cooking unit by a series of intervening baffles, wherein nozzles on the fixed pipes spray a wash liquid onto opposite sides of the filter simultaneously for cleansing purposes. However, it is not permissible to use this approach where one side of the filter unit is directly (i.e. visibly) exposed to the cooking unit since wash liquid from the spray nozzles, or bouncing off the exposed side of the filter unit, would fall on and contaminate the exposed cooking surfaces of the cooking unit. Further, with such fixed spray nozzles, it is difficult to obtain uniform application of the washing liquid to the filter unit faces. Also in such prior apparatus, no provision is made for cleaning the interior surfaces of the hood and exhaust stack beyond the filter.
Accordingly, the objects of this invention include provision of:
(1) A filtered ventilating system for a cooking unit, providing for rotating application of wash liquid sprays to interior contaminant and grease collecting surfaces of the hood and exhaust stack, and simultaneously to the back (stack facing) surfaces of a filter unit supported by the hood.
(2) A system, as aforesaid capable of cleaning with such wash liquid, both the inlet and outlet sides of the filter unit despite mounting of the filter unit to expose one of its sides directly to the cooking area and despite absence of wash down pipe spray nozzles between the filter unit and cooking unit.
(3) A system, as aforesaid, in which the filter unit shields the cooking area from wash down spray liquid and which is particularly adapted to use filter units generally of labyrinth type, e.g. employing opposed troughlike baffles which impart a sinuous flow pattern to cooking fumes traveling therethrough.
(4) A system, as aforesaid, in which the filter unit is readily reversed, side-for-side, in the hood, while yet remaining connected positively to the hood for ease in controlling and supporting the filter units during such reversal.
(5) A system, as aforesaid, which permits rotative driving, from a common motor, of wash down pipes extending transverse to one another in said hood and exhaust stack as well as providing for independent supply of wash liquid thereto from a common wash liquid source.
Other objects and purposes of this invention will be apparent to persons acquainted with apparatus of this general type upon reading the following specification and inspecting the accompanying drawings.
SUMMARY OF THE INVENTION
The objects and purposes of the invention are met by providing a filtered ventilating system for a cooking unit incorporating a hood emplaceable above a cooking unit and an exhaust stack extending from the hood for removing cooking fumes captured by the hood. A barrier wall divides the interior of the hood into inlet and outlet zones open to the cooking unit and exhuast stack, respectively, and is provided with a fume opening normally covered by a filter for grease and the like. Wash down pipes respectively extend along the exhaust zone of the hood adjacent the filter and along an exhaust stack. A motor rotates the wash down pipes and a suitable supply provides wash liquid to the pipes, which are thus energizable to simultaneously rotate and spray the wash liquid onto adjacent hood, filter and exhaust stack surfaces for cleaning same. Pivot and latch apparatus supports the filter for reversal on the barrier wall, to permit both sides of the filter to be cleaned by liquid from the wash down pipes.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary pictorial view of a ventilating hood, embodying the invention, shown in a position of use with respect to a cooking unit.
FIG. 2 is a fragmentary central cross-sectional view substantially taken on the line II--II in FIG. 1.
FIG. 2A is an enlarged fragment of FIG. 2.
FIG. 3 is a top view of the ventilating hood of FIG. 1.
FIG. 4 is a sectional view substantially taken on the line IV--IV of FIG. 3.
FIG. 5 is an enlarged fragment of FIG. 4.
FIG. 6 is a diagrammatic pictorial view of the wash down assembly for the apparatus of FIGS. 1-5.
FIG. 7 is an enlarged fragmentary view, taken substantially along the line VII--VII in FIG. 2 and showing a filter panel disposed in a filter opening within the ventilating hood.
FIG. 8 is an enlarged fragmentary sectional view substantially taken on the line VIII--VIII of FIG. 7.
FIG. 9 is a fragmentary sectional view substantially taken on the line IX--IX of FIG. 7.
FIG. 10 is an enlarged sectional view substantially taken on the line X--X of FIG. 7 and showing a fragment of FIG. 2 to illustrate the mounting and reversability of the filter panel.
FIG. 11 is an enlarged sectional view substantially as taken along line XI--XI in FIG. 7 and with one of the latches in its released position.
FIG. 12 is a view similar to FIG. 6 but showing a modified interrelation of wash down pipes.
DETAILED DESCRIPTION
FIG. 1 discloses a typical operating environment for the apparatus of the present invention, in which a ventilating hood 11 is fixed with respect to and opens downward over a fume-producing device 12 such as a cooking unit or units, here exemplified by a three-bay deep fat fryer. Cooking fumes, particularly heated air laden with volatilized grease or the like (hereafter simply referred to grease laden air), rise from the upward facing surface of the cooking unit 12 and collect within the downward opening hood 11 to be drawn therefrom up a communicating exhaust stack 14 by conventional means such as an exhaust blower schematically indicated at E, conventionally, the exhaust blower vents the fumes outside the building containing the hood 11 and cooking unit 12. The hood 11 and exhaust stack 14 may be fixed with respect to the ceiling, wall, or floor of the building in any convenient manner. In the particular embodiment shown, the hood is double-walled to define an inlet air chamber 16 (FIG. 2) between inner and outer hood shells 17 and 18. The chamber 16 receives fresh air through an inlet air stack 19, surrounding and extending along the exhaust stack 14 preferably from outside the building, by a conventional inlet air mover schematically indicated at I, such as a conventional motor driven blower. A fresh air outlet 21 may be conventionally provided from the lower front edge of the inlet air chamber 16.
The hood 11 here shown has an interior defined by the top, front, rear and sidewalls of the inner shell 18 and which opens downward (as seen in FIG. 2) toward the cooking unit 12. The interior of the hood is divided by a barrier wall 23 (FIGS. 2 and 10) into an inlet zone 25 open toward the cooking unit 12, and an outlet zone 26 open toward the exhaust stack 14. The barrier wall 23 extends the full width of the hood interior and incorporates an opening 28, preferably extending over a large part of the height and width of such barrier wall, for communication from inlet zone 25 to the outlet zone 26. The barrier wall 23 is preferably sloped so as to face forward and downward toward the cooking unit 12 and such barrier wall extends from the back wall 31 to the top wall 32 of the inner shell, connecting with such top wall forward (to the right in FIG. 10) of the exhaust stack 14. In use, the opening 28 is normally occupied by a filter panel 35 which fully occupies the opening 28, such that air swept into the inlet zone 25 of the hood 11, from above the cooking unit, can proceed to the outlet zone 26 and exhaust stack 14 only by passing through the filter panel 35. The filter panel 35 is to remove at least most of the grease and other contaminants in the air received from the cooking unit, before such air passes through stack 14.
Turning now in more detail to the present invention, a wash down assembly 41 (FIGS. 2-6) includes an elongate hood wash down pipe 43 which effectively spans the width of the outlet chamber 26 of the hood. A stack wash down pipe 44 extends upward into the exhaust stack 14, preferably substantially along the central axis thereof and to a point near the top of such exhaust stack. Spray nozzles 46 distributed along the wash down pipes 43 and 44 face radially therefrom for spraying a suitable wash liquid onto the opposed surfaces of the hood inner shell, filter and exhaust stack.
In the preferred embodiment shown, the hood wash down pipe 43 is offset rearwardly (leftwardly in FIG. 2A) and downwardly from the stack wash down pipe 44 in exhaust stack 14, such that the pipe 43 is spaced behind and substantially centered on the filter opening 28 and a filter panel 35 located therein. When so placed, the pipe 43 lies at least near the geometric center of the triangular cross section hood outlet zone 26. The ends of pipe 43 are closed against leakage and supported for rotation by suitable bearings 47 and 48 (e.g. simple sleeve bearings or bushings) fixed on the end walls 49 (FIG. 4) of the hood 11. A conventional liquid supply swivel 51 (FIGS. 2A and 5 interposed intermediate the ends of the pipe 43 serves to supply wash liquid to the pipe 43 while assisting in supporting it for rotation. As a practical matter, it will be understood that the pipe is open within the swivel such that the swivel joins and supplies liquid to the two visible end segments of the pipe 43. The swivel 51 is formed as a tee which connects to a wash liquid supply pipe 53 (FIGS. 2A and 6) which extends into the outlet zone 26 within the hood 11 along any convenient path. In the embodiment shown, the supply pipe 53 enters the top of the hood behind the stacks 14 and 19 and communicates with the swivel 51 through an elbow 54 and tee 56 interconnected by suitable nipples.
The stack wash down pipe 44 is supported for rotation within the stack. Preferably, a rigid strap member 59 (FIGS. 4 and 6) extends across the exhaust stack 14 near the upper end thereof. The opposite ends of the strap member 59 are bent upward at 61 (FIG. 6) for securement to the sidewalls of the stack 14 as by screws or the like. The upper end of the stack pipe 44 is supported for rotation on the strap 59 in any convenient manner. In FIG. 5 for example, the upper end of pipe 44 is capped against leakage at 62, which cap 62 rides rotatably on a bushing 63 fixed to and extending through the strap 59. If desired, a collar 64 fixed to the pipe 44 beneath the strap 59 limits upward movement of the pipe.
A swivel connector 66 (FIGS. 5 and 6) here serves to connect the lower end of stack pipe 44 not only with the liquid supply, but also with a rotary drive assembly generally indicated at 67 (FIGS. 2A, 5 and 6). The swivel connector 66, like swivel 51 above-mentioned, is of tee configuration, having a central liquid inlet leg 68 connected, here through elbows 70 and 71, to the wash liquid supply at elbow 56, through suitable interposed nipples or pipe lengths.
The rotary drive assembly 67 includes a rotatable motor 73, (preferably electric) which conveniently mounts atop the inner shell 18, within the inlet air chamber 16 of the hood 11, as seen in FIGS. 3-5. The rotating output shaft 74 of motor 73 extends through a suitable opening in the wall of exhaust stack 14. Secured to the end of motor shaft 74, within the exhaust stack 14 are rotational drive connections to the rotary hood pipe 43 and rotary stack pipe 44, which drive connectors here take the form of a chain drive 76 to the hood pipe 43 and a flexible drive 77 to the lower end of the stack pipe 46 within the swivel 66. The chain drive 76 comprises a coplanar pair of sprockets respectively fixed on the pipe 43 and motor shaft 74 and interconnected by an endless chain loop. The flexible drive 77 may be of conventional type and here comprises an L-shaped conduit 80 fixed at one end to the exterior of swivel 66 and at its other end supported by an internally bushed collar 81 with respect to the end of motor shaft 74. A flexible drive member 79 extends rotatably through the conduit and is fixed to the end of the pipe 44 within the swivel 66 to rotatably drive same. The input end of flexible drive member 79, within the collar 81, is fixed to the free end of the motor shaft 74 for rotation therewith.
Thus, both the substantially horizontal hood wash down pipe 43 and the substantially vertical exhaust stack wash down pipe 44 are simultaneously rotatable by the common drive motor 73. The spray nozzles 46 distributed along the pipes are thus rotated to apply wash liquid to the entire circumferential extent of the surrounding hood and stack surfaces.
Wash liquid is supplied to supply pipe 53 from a supply generally indicated in 81 in FIG. 6. The wash liquid supply 81 here includes a drum 82 for a suitable cleaning agent, such as a detergent and a pump 83 actuable to supply such detergent to a mixture control valve 85. Hot water, for example at a minimum of 140° F., is applied from a conventional hot water source schematically indicated at H, preferably through a conventional vacuum breaker 87 to the mixture control valve 85. The valve 85 is actuable to apply a mixture of hot water and detergent through the supply pipe 53 to the wash down pipes 43 and 44. The valve 85 may be of any convenient type presetable to a desired detergent-hot water ratio and actuable to turn on and off the hot water-detergent mixture input to supply pipe 53. The hot water source H may be for example a conventional water heating tank supplied at city, or higher, water pressure.
A master control panel 88 includes suitable manual and/or automatic means for demand or periodic supply of wash liquid to the wash down pipes 43 and 44, by simultaneous actuation of pump 83 and motor 73 and opening of mixture supply valve 85 as schematically indicated in broken lines at 90, 91 and 92 in FIG. 6. If desired, the valve 85 may be incorporated in the control panel 88 which may in turn be mounted at 85. If desired, the control 88 may be arranged to supply hot water alone, by shutting off detergent pump 83, after a quantity of detergent-water mix has been sprayed from the wash down pipes 43 and 44, for rinsing the hood, filter and exhaust stack surfaces surrounding the wash down pipes. Instead of a central control 88 of manual and/or automatic type, the liquid supply valve 85, detergent pump 83 and rotate motor 73 may be individually manually controlled to perform the wash down operation. If desired, the master control panel 88 may be located other than adjacent the detergent tank. On the other hand, it is contemplated that suitable electrical wash down controls may be mounted adjacent the hood in a readily accessible position, as on the front face of the hood, as at 94 (FIG. 1) for remote actuation of the master wash down control 88.
To collect wash liquid sprayed on and draining from the surfaces of the exhaust stack 14, hood outlet zone 26 and a filter panel 35 at opening 28, the barrier wall 23 forms a substantially V-shaped collection trough 96 (FIG. 10) with the back wall 31 of the hood. A drain conduit 97 connects the bottom edge of the trough 96 to a suitable drain for removal of used cleaning liquid from the hood.
When installed in the opening 28 in barrier wall 23, the filter panel 35 faces directly toward and is directly exposed to the top of the cooking unit 12 and thus its forward (inlet) side tends to collect heavy deposits of grease from the grease laden air swept into the hood from above the cooking unit. While some grease may penetrate through the filter to its rear (exhaust) side, the exhaust side of the filter can be cleaned of accumulated grease and the like by wash liquid sprayed from the rotating pipes 43 and 44. However, washing down the exhaust side of the filter panel does not, and it not intended to, result in cleaning of the intake side of the panel. Particularly, wash liquid expelled from the nozzles on pipe 43 is desirably blocked by the filter 35 and barrier wall 23 from entering the inlet zone 25, to avoid contaminating the space above and surfaces of the cooking unit 12 with used wash liquid carrying grease and other contaminants.
The filter panel 35 preferably comprises a rectangular perimeter frame 103 (FIGS. 7 and 11) of substantially U-shaped, or channel, cross section, which forms a rigid frame work. The actual filtering agent is held by perimeter frame 103 and in the preferred embodiment shown takes the form of two opposed sets of side-by-side trough members 104, here of substantially V-shaped configuration. As seen in FIG. 11, the trough members 104 have their convex faces, or vertices, 106 facing outwardly to form the corresponding side of the filter panel. The free edges of adjacent trough members 104 are spaced apart though substantially less than the width of a given trough member 104, to form an air passage 107 therebetween. As seen in FIG. 11, the free edges of two adjacent troughs 104 are spaced by an air passage 107 and intrude slightly into the opposed mouth 108 of a trough 104 of the opposite set. Accordingly, air passing through the filter panel 35 must travel the substantially S-shaped path 109 and thus tends to deposit entrained grease and other contaminants upon the surfaces of the troughs 104. The ends of the troughs 104 are fixed in the top and bottom channels 103 of the filter panel. To further rigidify the panel, a horizontal strap 111 extends sinuously between the two sets of troughs and is secured by any convenient means not shown, such as welding, to the central portions of each of the troughs 104. Drain holes 112 (FIGS. 7 and 8) are spaced along the top and bottom members of the perimeter frame, at the corners of the channel-shaped cross section, to permit the filter panel 35 to drain free of wash liquid applied thereto. While filter panels of different construction may be used in connection with the present invention, filter panels of the type shown at 35, with the interfingered troughs 104, have proved advantageous, not only for effectively filtering grease from air passing therethrough, but also for blocking travel of wash liquid from the sprays within the exhaust zone 26 of the hood, out into the inlet zone 25 and onto the cooking unit 12.
To support the filter panel 35 in its normal use position of FIGS. 7-9, the barrier wall 23 includes a rectangular perimeter flange 114 which extends rearward (leftward in FIG. 10) therefrom to a depth preferably somewhat exceeding the depth of the filter panel 35. The top and opposed sides of the perimeter flange 114 frame the fume opening 28 in the barrier wall 23. The bottom length 116 of perimeter flange 114 is spaced somewhat below the lower edge 117 of the fume opening 28 leaving an upward extending lip 119 along the bottom of fume opening 28. Plural drain openings 121 (FIG. 8), spaced along the forward edge of the bottom length 116 where it joins the lip 117, permit wash liquid draining from the filter panel 35 to drain downward along the inner surface of the barrier wall 23 to the drain conduit 97. The lower edge portion of the filter panel 35 rests on the flange bottom length 116 and lip 117. The bottom length 116 prevents the filter panel from sliding down along the inside of the barrier wall 23 and the lip 117 prevents the lower filter edge from falling forward out of the opening 28.
To block rearward movement of the filter panel 35 from its position of use into the exhaust zone 26 of the hood, further lips 122 and 123 on the rear edges of the top and side parts of perimeter flange 114 overlap the opening 28.
Latches 126, preferably fixed on opposite sides of the opening 28 to the barrier wall 23, prevent the filter panel 35 from falling forwardly from its normal operating position of FIGS. 7-9 and 11. In such operating position, the latches 126 urge the back face of the filter panel 35 against the top and side lips 122 and 123, while the bottom edge of the filter panel 35 rests atop the flange bottom length 116 at lip 119. Preferably the filter panel 35 has small risers 125 along its upper and lower edges to space the filter perimeter frame 103 a bit above the flange bottom length 116.
In the embodiment shown, the latches 126 shown in FIG. 11 are conventional over-center latch units each having a base 131 fixed, as by rivets to the barrier wall 23 and pivotally supporting an operating lever 132 and a clamping lever 133, which are pivotally interconnected by an over-center link 134. A resilient block 136 adjustably supported on the free end of clamping lever 133 forceably engages the forward face of the filter panel 35 in the latched, over-center position of operating lever 132 (to the right in FIG. 11) and, alternatively, swings forwardly and laterally away from the filter panel 35 in response to unlatching movement of the operating lever 132 to its position to the left in FIG. 11, to permit the filter panel 35 to move forwardly out of opening 28. When closed, the latches 126 snugly urge the filter panel against the lips 122 and 123.
A pivoting lost motion connection 141 (FIGS. 7, 9 and 10) permits cleaning of both sides of the filter panel 35 while it is attached to the hood 11. Connection 141 comprises an elongate link 142 on each side of the filter panel 35. The upper end of each link 142 is pivoted at 143 on the corresponding side of the perimeter flange 114 at the edge of opening 28. The location of pivot 143 preferably is somewhat above the center of the opening 28. A headed pin 144 fixed centrally to and extending sidewardly from the perimeter frame 103 of filter 35 is captive in pivoting and sliding relation in a slot 146 extending the major, lower length of the link 142. When installed in opening 28 as in FIG. 9, the link 142 extends from its pivot 143 along the adjacent side of the filter panel 35 with the filter supporting pin 144 near but not at the top of the slot 146 in link 142.
Upon release of the latches 126, the filter 35, in response to gravity, pivots forwardly as generally indicated by arrow R (FIG. 10) raising the lower end of the filter 35 over the lip 119. At the same time, the link 132 pivots forward along arrow S and the filter panel, riding on its sidewardly extending pins 144, slides downward along the slots 146 of links 142 to the bottom thereof, as indicated by arrow T. Thereafter, the filter panel 35 can be manually rotated, as indicated by arrows U, through 180°. The above-mentioned removal steps, indicated by arrows T, S and R, can then be reversed to restore the panel 35 to its installed position in opening 28 but with the sides reversed.
In a typical wash down operation, the wash down pipes 43 and 44 are operated briefly to clean one side of the filter panel 35 installed in the opening 28, the liquid supply to the rotating pipes 43 and 44 is shut off, and the filter panel 35 is reversed as indicated by arrows R, S, T and U above-discussed with respect to FIG. 10. With the filter panel 35 installed once again in opening 28, but reversed side-for-side, the wash down pipes are once again actuated, and wash the other side of the filter panel 35. After a period of use of the hood 11 this washing cycle can be repeated, either by manual actuation or automatically as desired. In addition to cleaning both sides of the filter, this wash down cycle also results in cleaning of the remaining interior surfaces of the outlet zone 26 of the hood 11 and of the exhaust stack 14, as a result of the wash liquid sprayed by the rotating pipes 43 and 44 on these surfaces.
As seen above, the filter unit 35 during its 180° reversal described with respect to FIG. 10, remains pivotally and slidably joined to the links 142 by reason of the engagement of its headed pins 144 and the corresponding slots 146. If desired, the filter unit 35 can readily be disconnected from the links 142 while in its FIG. 10 position, simply by raising filter unit 35 upward along the slots 146 until pins 144 reach the top of the slots. The tops of the slots are enlarged as indicated at 147, sufficient to pass axially therethrough the large head of the corresponding pin 144, as by slight laterally outward flexing of the links 142. Reinstallation of a filter unit on its links 142 is accomplished by reversal of such steps.
The enlarged upper end 147 of the slot 146 lies somewhat above the corresponding pin 144 with the filter unit 35 in the filter opening 28, as can be seen in FIG. 9. Moreover, the filter unit 35 is free to pivot forwardly and downwardly (via arrow R in FIG. 10) without advancing the pin 144 upward into the enlarged upper end 147 of slot 146. Accordingly, the pins 144 are normally laterally retained by their enlarged heads within the corresponding slots 146, either in the FIG. 9 position of use or the FIG. 10 reversing manipulation, such that the filter unit 35 is removable from the links 142 only by a purposeful raising of its pins 144 above their normal range of movement within the slots 146 so that they can reach and exit from the enlarged upper slot ends 147.
MODIFICATION
FIG. 12 schematically discloses a modified wash down pipe arrangement. Parts of the FIG. 12 apparatus, similar to parts in FIGS. 1-11, carry the same reference numerals with the suffix "A" added. In FIG. 12 the horizontal hood wash down pipe 43A is moved forward in the hood 11A so as to be coplanar with the upstanding stack wash down pipe 44A. This permits rotative joining of pipes 43A and 44A through a conventional right-angle gear drive, or transmission, 161. Also in FIG. 12, the rotative drive motor 71A is conveniently mounted on one side of the hood 11A with its drive shaft fixed to the adjacent end of the hood pipe 43A to rotatably drive same, and through the transmission 161, to simultaneously rotatably drive the stack pipe 44A. To assist in locating the rotating pipes 43A and 44A, the lower portion of 44A, just above transmission 161, passes through a suitable bushing 162 carried by a strap member 163. The strap member 163 may be similar to aforementioned strap member 59 of of FIG. 6, spans the lower end portion of the exhaust stack 14A and is suitably anchored to the sidewalls thereof. Wash liquid is brought into the hood 11A by a fixed supply pipe 53A which connects to the upstanding stack pipe 44A through a conventional water transfer swivel 166 and additionally connects to the horizontal hood pipe 43A. The latter connection is conveniently through a conventional right-angle swivel 167 which is also provided with mounting flanges 168 for rotatably supporting the rightward end of the horizontal pipe 43A on the rightward wall of the hood 11A. Additional supporting bearing may be provided along the rotatable wash down pipes, as at the upper end of the pipe 44A generally in the manner of FIG. 6 at 59,61.
The FIG. 12 embodiment operates substantially in the manner above-described with respect to the embodiment of FIGS. 1-11. The FIG. 12 embodiment reduces somewhat the number of piping and drive components in the central area of the hood 11A, by use of the right angle drive transmission 161 to join the pipes 33A and 44A in substantially coplanar relation. However, the FIG. 12 arrangement requires the hood pipe 43A to be shifted forward somewhat from its generally centered location of FIGS. 1-11, bringing it closer to the filter panel, which, unless particular care is taken in distributing spray nozzles along the horizontal wash down pipe, may produce a less uniform washing action than in the FIGS. 1-11 embodiment.
The pipes and pipe fittings disposed within the hood 11 or 11A, as above-discussed with respect to FIGS. 1-12, are preferably of stainless steel for maximum durablity. However, use of other materials, such as galvanized steel, is also contemplated. The aforementioned swivels of FIGS. 1-12 are preferably commercially available, nickle-plated swivel connectors with impregnated teflon bearings for reducing rotating friction. In one embodiment, standard 1/2 inch size pipe was used for the rotating pipes and liquid supply pipe assembly. Typically, in the embodiment of FIGS. 1-11, nozzles are distributed on 8 inch centers along the hood wash down pipe 43 and deliver about 0.7 gallon per minute of wash down liquid at about 40 pounds per square inch pressure, while nozzles on the stack pipe 10 are disposed on 10 inch centers with each delivering about 0.4 gallons per minute at about 40 pounds per square inch pressure. Consideration has been given to use of a higher pressure wash liquid supply and in one embodiment, according to the modified FIG. 12 embodiment for example, nozzles on the pipes 43A and 44A are distributed on about 6 inch centers with each delivering about 0.5 gallon per minute at about 150 pounds per square inch pressure.
Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modification of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention. | 4y
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TECHNICAL FIELD
The present invention relates to a tool changing device for a cutting head of a machine for cutting flat glass sheets.
BRIEF DISCUSSION OF RELATED ART
Currently known machines for cutting flat glass sheets generally have a resting surface for a glass sheet to be worked, and associated with such resting surface is a bridge, which is motorized in order to travel its length, and which carries a cutting head, which in its turn is motorized for translational motion on such bridge.
The cutting head has a wheel tool at its end, such tool comprising a body, to which the cutting wheel, which in the sector jargon is called “clip” is hinged, such body being shaped so as to reversibly engage in a corresponding seat on the end of the cutting head.
Depending on the type and thickness of the glass sheet, the use of a dedicated and specific cutting wheel is in fact necessary, so that for each type of sheet the most correct cutting of the glass will be performed.
Since, on the work surface, sheets of different thicknesses and types can follow each other, it is necessary that the substitution of the cutting wheels can be rapid, and indeed the clip tool is easy to remove and apply, even if it is done manually.
Some of the current glass cutting machines known today are provided with tool changing devices, which however limit the tool changing position to a specific region of the cutting area, thus forcing the dimensions of the machine and the paths of the working axes to be increased, as well as lengthy tool changing operations, even if these are automatic, and which in the end are not very functional, given that the tool changing position is arrived at electronically with the interpolation of two axes without mechanical alignment.
Moreover, these machines with tool changing devices have been shown to be difficult to maintain and economically disadvantageous, while limiting the productivity of the machine itself owing to a cycle time that is too long.
BRIEF SUMMARY
The aim of the present invention is to provide a tool changing device for a cutting head of a machine for cutting flat glass sheets, which is capable of overcoming the drawbacks in known types of tool changing devices.
Within this aim, the invention provides a tool changing device that makes it possible to eliminate fruitless idle excursions to arrive at the tool changing region, so improving the production rates of the cutting machine of which it is a part.
The invention further provides a tool changing device with which clip tools of a per se known type can be associated.
The invention also is intended to devise a tool changing device that is rapid, exact and has a low cost.
The invention further provides a tool changing device for a cutting head of a machine for cutting flat glass sheets, which can be produced using known technologies and equipment.
This is achieved by a tool changing device for a cutting head of a machine for cutting flat glass sheets, characterized in that it comprises, so that they can slide in a parallel arrangement with means for sliding on a bridge that supports the cutting head,
a carriage for supporting a cutting head, with motorization means for translational motion on said bridge, a tool supporting slider, which is normally coupled, by way of reversible fixing means, to said head supporting carriage during the work of said cutting head and which can be uncoupled, for tool changing operations, in order to allow the movement of said carriage with respect to said slider, which is stationary, to select a tool to be used.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages of the invention will become better apparent from the following detailed description of a preferred, but not exclusive, embodiment of the tool changing device according to the invention, illustrated, by way of non-limiting example, in the accompanying drawings, wherein:
FIG. 1 is a partially sectional side view of the device according to the invention;
FIG. 2 is an exploded perspective view of the device according to the invention;
FIG. 3 is a top view of a detail of the device according to the invention;
FIG. 4 is a partially sectional front elevation view of a part of the tool supporting slider.
FIGS. 5 to 14 each schematically show a step in the tool changing operation.
DETAILED DESCRIPTION
With reference to the figures, a tool changing device for a cutting head of a machine for cutting flat glass sheets is generally designated by the reference numeral 10 .
The device 10 comprises, so that they can slide in a parallel arrangement with sliding means on a bridge 11 that supports a cutting head 12 ,
a carriage 13 for supporting the cutting head 12 , provided with motorization means 14 for translational motion on the bridge 11 , and a tool supporting slider 15 , which is normally coupled, by way of reversible fixing means 16 for detachably fixing the tool supporting slider 15 to the carriage 13 , to the carriage 13 during the work of the cutting head 12 and which can be uncoupled, for tool changing operations, in order to allow the movement of the carriage with respect to the slider, which is stationary, to select a tool to be used.
The bridge 11 is understood to be laterally supported by abutments 17 which are associated with a worktable 18 .
The means for the sliding of the carriage 13 on the bridge 11 are constituted by an electric motor 19 , which is supported by a bracket 23 that is jointly connected to the carriage 13 , with a pinion 20 engaged with a rack 21 which is fixed to the bridge 11 .
The carriage 13 for supporting the head 12 is constituted by a supporting plate 22 , which is substantially perpendicular with respect to the worktable 18 , which is normally horizontal, the cutting head 12 with the respective means for moving the tool being fixed to the plate 22 at one end, i.e. an actuator 24 for the vertical translational movement of the end 30 a to which the tool is fixed, and a motor 25 for the rotation of such end, and at the opposite side, on the bridge side, at least four sliders 26 for sliding on corresponding rails 27 and 28 associated with the bridge 11 , as well as stroke limiting means 29 for the vertical actuator 24 , which are designed to measure the lowering of the end 30 a of the stem 30 of the cutting head for tool changing operations, described in more detail hereinbelow.
The tool supporting slider 15 is constituted by a bracket 31 which is L-shaped, the vertical section of which has two second sliders 32 , which are arranged so as to slide on the rails 27 and 28 , each interposed between two first sliders 26 of the carriage 13 which can slide on the same rail.
The horizontal portion 33 of the L-shaped bracket 31 carries a rack 34 for supporting tools 35 , which is moved in a sliding fashion by means of an actuator 36 which is fixed below the horizontal portion 33 .
The tool supporting rack 34 is moved by a stem 36 a of the actuator 36 , and is supported by means of a frame 37 to which it is fixed, the frame 37 being provided with sliding wheels 38 which are associated with corresponding guides 39 which are fixed to the actuator 36 and are therefore jointly connected to the bracket 31 .
The reversible fixing means 16 for detachably fixing the tool supporting slider 15 to the carriage 13 , are constituted by an actuator which is fixed to the vertical portion of the bracket 31 , with a tip 40 which can be extracted and retracted for engagement or disengagement with respect to a hole 41 chosen among a series of holes formed in the face of the supporting plate 22 that is directed toward the bridge 11 .
There are at least as many holes 41 as the number of tools carried by the tool supporting rack 34 .
The tools 35 , which are understood to be known per se, with clip bodies for quick and reversible engagement in a corresponding seat formed in the end 30 a of the cutting head 12 , and since they are known they are not shown for simplicity, have two lateral symmetric hollows 44 , which are extended at right angles with respect to the vertical direction of movement of the stem 30 of the cutting head and are designed to slide on complementary shaped protrusions 45 which protrude laterally from teeth 47 in compartments 46 of the rack 34 .
The stroke limit means 29 for the vertical actuator 24 , which are designed to measure the lowering of the end 30 a of the stem 30 of the cutting head for tool changing operations, are constituted by a fluid-operated actuator designed to produce the translational motion of a piston 19 a.
When the stem 30 needs to be lowered for the tool to be changed, the fluid-operated actuator is commanded to extract the piston 19 a to protrude from the plate 22 until it affects the downward stroke of the motor 25 , to which the stem 30 is fixed.
When the stem 30 needs to be lowered until the tool is brought to the worktable 18 , then the fluid-operated actuator is actuated to retract, so freeing the vertical motion of the motor 25 to which the stem 30 is fixed.
The operation of the tool changing device 10 according to the invention is as follows, and is illustrated in the Figures from 5 to 14 .
A first step of the tool changing operations is shown in FIGS. 5 and 6 .
In this first, illustrative, step, the slider 15 is jointly connected to the carriage 13 , and therefore the tip 40 , which is jointly connected to the slider 15 , is inserted into a first hole 41 a formed in the plate 22 of the carriage 13 .
The slider 15 is fixed in a first relative position with respect to the carriage 13 .
It is assumed that the cutting head 12 has a first tool 35 a in use and that it needs to uncouple it.
In FIG. 7 the piston 29 a can be seen extracted so as to interfere with the downward stroke of the motor 25 . The position of the piston 29 a on the plate 22 determines a stroke of the motor 25 which is such as to lower the tool 35 a to the height of the tool supporting rack 34 .
FIG. 8 shows the sliding movement of the tool supporting rack 34 , and this sliding movement ensures that the corresponding prearranged compartment, which is designated by the reference numeral 46 a in order to identify it by way of example with respect to the other similar compartments 46 of the rack 34 shifts until the protrusions 45 protruding on it couple with the corresponding hollows 44 of the tool 35 a , the compartment 46 a , the protrusions 45 and the hollows 44 being shown in FIGS. 3 and 4 .
The subsequent operation of lifting the stem 30 determines the rapid detachment of the first tool 35 a from the end 30 a , as in FIG. 9 .
Also in FIG. 9 the tip 40 is shown retracted from the hole 41 . This configuration of the tip frees the slider 15 from the carriage 13 , allowing the latter to move with respect to the slider itself as shown in FIG. 10 .
With the slider 15 stationary, the carriage 13 , now freed from the slider, moves to a second position, for example to load the second tool 35 b , which is arranged at the other end of the rack 34 with respect to the first tool 35 a , as shown in FIG. 10 , the first tool 35 a and the rack 34 being shown for example in FIGS. 7 and 8 , and the second tool 35 b being shown by way of example in FIGS. 11 to 14 .
The end 30 a remains lifted and the piston 29 a remains extracted, as shown in FIG. 11 .
FIG. 12 shows the end 30 a lowered to engage the second tool 35 b , with the motor 25 , shown for example in FIG. 7 , which is in abutment at its stroke limit against the piston 29 a , already shown in FIG. 11 .
FIG. 13 shows the rack 34 which retracts, the stem 30 with the new tool 35 b which raises and the piston 29 a which retracts in order to permit the lowering to the level of the worktable 18 , such situation being shown in FIG. 14 .
In practice it has been found that the invention fully achieves the intended aim and objects.
In particular, with the invention a tool changing device has been developed which makes it possible to eliminate fruitless idle excursions to arrive at the tool changing region, since the slider 15 with the tool supporting rack 34 travels with the carriage 13 that carries the cutting head 12 , and long excursions are not necessary for the cutting head to reach magazines which are fixed at the edges of the worktable. This improves the production rates of the cutting machine of which the device is a part.
Moreover, with the invention a tool changing device has been developed in which the translational movement of the slider with the tool supporting rack with respect to the cutting head supporting carriage to change the tool is executed by the same motor that moves the cutting head with respect to the bridge, without the addition of other motors.
Further, the tip 40 of the reversible fixing means 16 is controlled by position sensors which enable a correct mechanical alignment between the tool supporting rack and the cutting head before and during every tool change.
The device according to the invention makes it possible to resolve all the above-mentioned problems concerning current, fixed-position tool changing systems.
The tool change is thus extremely simple, precise, i.e. always mechanically aligned, and extremely rapid.
The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.
In practice the materials employed, as well as the dimensions and the contingent shapes, may be any according to requirements and to the state of the art.
The disclosures in Italian Patent Application No. PD2009A000315 from which this application claims priority are incorporated herein by reference. | 4y
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This invention relates to a novelty writing instrument and more particularly to an inexpensive writing instrument having at least a two part construction, with the two parts being movable relative to one another to create an illusion.
DESCRIPTION OF THE PRIOR ART
In the prior art there have been various means for creating an illusion, and in particular to create an illusion on a writing instrument. One of the more successful prior art devices is the novelty writing instrument shown in my earlier U.S. Pat. No. 4,037,343. While this prior art device works well and creates a superb illusion, it has the disadvantage of being relatively complicated in structure, expensive to manufacture, and consequently must be sold at a higher price than a similar pen without the illusion producing feature.
BRIEF DESCRIPTION OF THE INVENTION
The novelty writing instrument of the present invention comprises at least two relatively movable members, preferably in the form of a body member carrying writing means and a cover or cap member for said body member for covering said writing means. Said body is one color and has at least a portion thereof of a different color forming part of the illusion producing means. The cap has an opening therein which also contains another portion of an illusion producing means. The illusion producing means on the cap includes a film carrying the image which is altered so as to create the illusion. The illusion is created by manually changing the relative position of the cap on the body so as to position the film over or away from the different color portion on the body.
It is one object of the present invention to provide a writing instrument with an illusion producing feature which is uncomplicated and inexpensive to manufacture.
Another object of the present invention is to provide a novelty writing instrument with an illusion feature that can be competitively marketed with other inexpensive writing instruments.
Still another object of the present invention is to provide a two part writing instrument with an illusion means which operates when the relative position of the two parts are manually changed.
These and other objects of the present invention will become apparent from the following written description and the accompanying figures of the drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of one embodiment of a novelty writing instrument of the present invention with a portion thereof shown in exploded view;
FIG. 2 is a perspective view of the novelty writing instrument of FIG. 1 shown in one relative position;
FIG. 3 is a perspective view of the novelty writing instrument of FIG. 1 shown in a second relative position;
FIG. 4 is a perspective view of a second embodiment of novelty writing instrument of the present invention;
FIG. 5 is a perspective view of the novelty writing instrument of FIG. 4 shown in one relative position; and
FIG. 6 is a perspective view of the novelty writing instrument of FIG. 4 shown in a second relative position.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 to 3, the first embodiment 10 of the novelty writing instrument of the present invention is illustrated. As shown in FIG. 1, embodiment 10 has a plastic body member 12 which has an upper tapered end 14 and a lower, generally cylindrical end 16. A conventional writing mechanism 18 (only the top of which is shown), e.g., pencil, ballpoint, felt-tip or ink pen mechanism, is housed within the body member 12. If desired the juncture between the upper and lower ends 14 and 16 may be discontinuous or stepped (as indicated by the line 20), instead of smooth, for purposes of locating the cap member 24, hereinafter described, on the body member.
The embodiment 10, as mentioned includes a plastic cap member 24, which can alternatively fit on either the ends 14 or 16 of the pen. The placement on or removal of the cap member 24 covers or exposes the writing mechanism 18, as in conventional. The cap 24 may also be fitted with a pocket clip 26.
The illusion means or mechanism 30 has portions on both the body member 12 and cap member 24. In more detail, the cap member 24 has an opening 32 formed in it, the opening being of a shape complimentary to the shape of the cap and of the illusion to be provided. Illusion means 30 included a film element 34 and a background 36 which are secured in place to the cap member as by gluing or snap fit in an appropriate groove (not shown) formed about the margin of the opening 32. The film 34 carries an image, in this instance that of an attractive nude woman (indicated by member 24), which is otherwise transparent. The background 36 is opaque or non-transparent (indicated by the numeral 38) except for portions thereof which are to be made to appear and disappear, in this instance the woman's bathing suit (indicated by the numeral 40). The portion that is to appear and disappear (e.g. the bathing suit 40) is clear and/or translucent. The background's opaque portions may be formed by directly painting onto the inner surface of the film. By painting it on the inner surface, the film serves as protection for the applied coating. Otherwise, the background is placed behind the film.
The body member 12 at its upper end 14 carries a different color, preferably black, area or portion 42 (as indicated by the cross-hatching) which can be made to align with the transparent area 40 of the background 36, when the cap is installed in the body. The different color portion 42 does not extend completely around the entire circumference of the pen, but is of a size to cover only the clear area 40 of the background 36. A convenient manner in which to form the different color area is to apply or paint it onto the body 12, as by silk screening.
In this instance, the opaque portion 38 of the background 36 can be a desired color, and the color of the pen member 12 (other than for that of portion 42), is such as to permit the features of film 34 to be seen.
As can be seen in FIG. 2, when the cap member 24 is relatively positioned on the body member 12 so that the different color portion 42 is not behind the clear portion 40, all the features of the film are visible, i.e., the woman appears to be nude. As seen in FIG. 3, simply rotating the body member 12 and cap member 24 relative to one another, as indicated by the arrow 39, so that the different color portion 42 is behind the clear portions 40 changes the illusion. In such position the dominant dark different color area 42 is seen through the clear portions 40 and causes the features on the film 34 directly in front to be obliterated giving the appearance of the woman being clothed in a dark bathing suit.
Referring now to FIGS. 4 through 6, a second embodiment 50 of novelty writing instrument of the present invention is shown. In embodiment 60 there is a body member 52 and cap member 54. The cap member 54 is generally similar in construction to cap 24 of the first embodiment. As FIG. 4 shows, the different color portion 56 (indicated by the cross-hatching) is formed by the entire upper end of the body member 52. In embodiment 50 the change of the image or illusion occurs when the cap 54 is transferred from one end to the other end of the body member, instead of by relative rotation. As shown in FIG. 5 when the cap 54 is over the different color portion 56, the woman appears to be clothed in a bathing suit. When the cap is on the other end, as shown in FIG. 6, she appears to be nude.
While only the preferred embodiments on novelty writing instrument of the present invention has been illustrated and described, from the foregoing it should be understood that variations, modifications and equivalent structures thereof fall within the scope of the following claims: | 4y
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This application is a continuation application of international application No. PCT/GB97/01721 filed Jun. 24, 1997, of which the entire disclosure of the prior application is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the use of chelating agents and their metal chelates and to the use of certain manganese containing compounds, in particular manganese chelates, in medicine. In particular, the invention relates to the use of such compounds in anti-tumour therapy.
2. Description of the Related Art
A number of anti-tumor agents are associated with adverse side-effects which severely limit their widespread use. Paclitaxel or taxol is one such agent which has shown anti-neoplastic action against a variety of malignant tissues, including those of the breast, colon, lung and ovary as well as in malignant melonoma. However, at the high dosages required to have an anti-neoplastic effect, paclitaxel has a number of adverse side-effects which can include cardiovascular irregularities as well as hematological and gastrointestinal toxicity.
Anthracycline antibiotics, such as doxorubicin (adriamycin), are amongst the most important of the anti-tumour agents. However, their clinical value is limited by their cardiotoxicity, which manifests itself as congestive heart failure in 15-40% of patients undergoing therapy. The most likely mechanism for their toxicity is believed to be the production of oxygen-derived free radicals in the heart, which cause membrane damage and mitochondrial damage in metabolically active tissues such as heart muscle and intestinal mucosa.
There is evidence to suggest that cardiac damage during anthracycline therapy can be reduced by simultaneous administration of the iron chelator, dexrazoxane (Goodman & Gilman, 9th ed. 1233-1287 (1996)). However, dexrazoxane and its analogues have been found to be toxic and as a result can only be used in relatively low dosages.
It will be appreciated that there thus exists a continuing need for compounds which are able to act as chemoprotectants during anti-cancer therapy.
In particular, there exists the need for an effective chemoprotectant which in reducing the toxic side effects of the anti-tumour agent, will permit higher, more effective doses of the anti-tumour agent to be administered.
The medical use of chelating agents and their metal chelates is well established, for example in diagnostic techniques such as X-ray, magnetic resonance imaging (MRI) ultrasound imaging or scintigraphy. A wide variety of chelating agents and metal chelates are known or have been described.
Aminopoly (carboxylic acid or carboxylic acid derivative) chelating agents and their metal chelates are well known and are described for example in EP-A-299795, EP-A-71564, DE-A-3401052, EP-A-203962 and EP-A-436579.
Dipyridoxyl based chelating agents and their chelates with trivalent metals have been described by Taliaferro (Inorg. Chem. 23: 1183-1192 (1984)). The compound N,N'-dipyridoxyl ethylenediamine-N,N'-diacetic acid (PLED) has been evaluated as a chelating agent for the preparation of gallium or indium containing radiopharmaceuticals (see Green et al. Int. J. Nucl. Med. Biol, 12(5): 381-386 (1985)).
A number of PLED derivatives and analogues have also been described for use in MRI contrast media, in particular the chelating agent N,N'-bis-(pyridoxal-5-phosphate)-ethylenediamine-N,N'-diacetic acid (DPDP) and its manganese (II) chelate, Mn DPDP (see EP-A-290047 and EP-A-292761).
BRIEF SUMMARY OF THE INVENTION
We have now found that certain chelating agents, in particular dipyridoxyl and aminopolycarboxylic acid based chelating agents, and their metal chelates are particularly effective in reducing the toxicity of anti-tumour agents, in particular anthracyclines and paclitaxel.
We have also found that certain manganese containing compounds are effective in reducing the toxicity of anti-tumor agents.
In one aspect the invention provides the use of a physiologically tolerable manganese compound or salt thereof, preferably having a molecular weight of less than 5000, more preferably less than 1000, e.g. less than 800, in the manufacture of a therapeutic agent for use in reducing the cardiotoxicity of an anti-tumour agent, e.g. an anthracycline drug and/or paclitaxel.
In another aspect the invention provides a method of reducing the cardiotoxicity of an anti-tumor agent administered to the human or non-human animal body, said method comprising administering to said body an anti-tumor agent and simultaneously, separately or sequentially a physiologically tolerable manganese compound or salt thereof, preferably having a molecular weight of less than 5000, more preferably less than 1000, e.g. less than 800.
Conveniently, the manganese compound may be present as a chelate, preferably having a K a in the range of from 10 9 to 10 25 , more preferably 10 10 to 10 24 , yet more preferably 10 11 to 10 23 , e.g. 10 12 to 10 22 . Particularly preferred chelates are those having a K a value smaller by a factor of at least 10 3 than the K a value of the corresponding iron (Fe 3+ ) chelate.
In a second aspect the invention provides the use of a compound of formula I ##STR1## or a metal chelate or salt thereof in the manufacture of a therapeutic agent for use in reducing the cardiotoxicity of an anti-tumor agent, e.g. an anthracycline and/or paclitaxel (wherein in formula I
each R 1 independently represents hydrogen or --CH 2 COR 5 ;
R 5 represents hydroxy, optionally hydroxylated alkoxy, amino or alkylamido;
each R 2 independently represents a group XYR 6 ; X represents a bond, or a C 1-3 alkylene or oxoalkylene group optionally substituted by a group R 7 ;
Y represents a bond, an oxygen atom or a group NR 6 ;
R 6 is a hydrogen atom, a group COOR 8 , an alkyl, alkenyl, cycloalkyl, aryl or aralkyl group optionally substituted by one or more groups selected from COOR 8 , CONR 8 2 , NR 8 2 , OR 8 , =NR 8 , =O, OP(O) (OR 8 )R 7 and OSO 3 M;
R 7 is hydroxy, an optionally hydroxylated, optionally alkoxylated alkyl or aminoalkyl group;
R 8 is a hydrogen atom or an optionally hydroxylated, optionally alkoxylated alkyl group;
M is a hydrogen atom or one equivalent of a physiologically tolerable cation, e.g. an alkali or alkaline earth cation, an ammonium ion or an organic amine cation, such as a meglumine ion;
R 3 represents a C 1-8 alkylene group, preferably a C 1-6 , e.g. a C 2-4 alkylene group, a 1,2-cycloalkylene group, or a 1,2-arylene group; and
each R 4 independently represents hydrogen or C 1-3 alkyl).
Other chelators suitable for use in the method of the invention include the macrocyclic and more preferably linear or branched aminopolycarboxylic acid chelants of EP-A-299795, EP-A-71564, DE-A-3401052, EP-A-203962, EP-A-436579 and the phosphorus oxyacid analogs. Preferred chelating agents include DTPA and EDTA and amides thereof in which the nitrogens of the amide groups may be substituted by one or more C 1-18 alkyl groups, e.g. DTPA.BMA and EDTA.BMA.
As used herein the terms "alkyl" and "alkylene" include both straight-chained and branched, saturated and unsaturated hydrocarbons. The term "1,2-cycloalkylene" includes both cis and trans cycloalkylene groups and alkyl substituted cycloalkylene groups having from 5-8 carbon atoms. The term "1,2-arylene" includes phenyl and napthyl groups and alkyl substituted derivatives thereof having from 6 to 10 carbon atoms.
Unless otherwise specified, any alkyl, alkylene or alkenyl moiety may conveniently contain from 1 to 20, preferably 1-8, more preferably 1-6 and especially preferably 1-4 carbon atoms.
Cycloalkyl, aryl and aralkyl moieties may conveniently contain 3-18, preferably 5-12 and especially preferably 5-8 ring atoms. Aryl moieties comprising phenyl or naphthyl groups are preferred. As aralkyl groups, phenyl C 1-3 alkyl, especially benzyl, are preferred.
Where groups may optionally be substituted by hydroxy groups, this may be monosubstitution or polysubstitution and, in the case of polysubstitution, alkoxy and/or hydroxy substituents may be carried by alkoxy substituents.
In formula I, R 5 is preferably hydroxy, C 1-8 alkoxy, ethylene glycol, glycerol, amino or C 1-8 alkylamido. Preferably each group R 1 represents --CH 2 COR 5 in which R 5 is hydroxy.
In the compounds of formula I, X is preferably a bond or a group selected from CH 2 , (CH 2 ) 2 , CO, CH 2 CO, CH 2 CH 2 CO or CH 2 COCH 2 . Preferably, Y represents a bond.
The compounds of formula I may have the same or different R 2 groups on the two pyridyl rings and these may be attached at the same or different ring positions. However, it is especially preferred that substitution be at the 5- and 6-positions, most especially the 6-position, i.e. para to the hydroxy group. Compounds in which the R 2 groups are identical and identically located, e.g. 6,6', are especially preferred.
Preferred as groups R 6 are mono- or poly(hydroxy or alkoxylated) alkyl groups or a group of the formula OP(O) (OR 8 )R 7 .
R 7 is preferably hydroxy or an unsubstituted alkyl or aminoalkyl group.
Particularly preferred identities for group R 2 include CHR 7 OCO(CH 2 ) x Ph and CHR 7 OCO(CH 2 CO) x Ph (wherein x is 1 to 3), CHR 7 OCOBu t , CH 2 N (H)R 6 ', CH 2 N(R 6 ') 2 , N(H)R 6 , N(R 6 ') 2 , CH 2 OH, CH 2 OR 6 ', COOR 6 ', CON(H)R 6 ', CON(R 6 ') 2 or OR 6 ' (where R 6 ' is a mono- or polyhydroxylated, preferably C 1-4 , especially preferably C 1-3 , alkyl group), (CH 2 ) n COOR 7 (wherein n is 1 to 6), COOR 7 ' (where R 7 ' is a C 1-4 alkyl, preferably C 1-3 , especially preferably a methyl group), CH 2 OSO 3 -- M, CH 2 CH 2 COOH, CH 2 OP(O) (OH) (CH 2 ) 3 NH 2 , CH 2 OP(O) (OH)CH 3 or CH 2 OP(O) (OH) 2 group. Yet more preferably, R 2 represents a group of the formula CH 2 OP(O) (OH) 2 .
Compounds of formula I in which R 3 is ethylene and R 2 has any of the identities listed above are particularly preferred.
Preferred metal chelates of the compounds for use in the method of the invention are those in which the metal ions are selected from the alkali and alkaline earth metals and from those metals having an atomic number from 22-31, 42, 44 and 58-70 and more particularly chelates having a K a in the range from 10 9 to 10 25 , preferably 10 10 to 10 24 , more preferably 10 11 to 10 23 , e.g. 10 12 to 10 22 . Particularly preferred chelates are those with metals other than iron which have a K a value smaller, preferably by a factor of at least 10 3 , than the K a value of the corresponding iron (Fe 3+ ) chelate. Suitable ions include Na + , Mn 2+ , Cu + , Cu 2+ , Mg 2+ , Gd 3+ , Ca 2+ and Zn 2+ . Mn 2+ is especially preferred.
As chelates of aminopolycarboxylic acids, MnDTPA, MnEDTA, Mn DTPA.BMA and Mn EDTA.BMA are particularly preferred for use in accordance with the invention.
More particularly preferred for use in accordance with the invention is the compound N,N'-bis-(pyridoxal-5-phosphate)-ethylenediamine-N,N'-diacetic acid or N,N'-bis(3-hydroxy-2-methyl-5-phosphonomethyl-4-pyridyl-methyl)-ethylenediamine-N,N'-diacetic acid (hereinafter referred to as DPDP) and the manganese (II) chelate, Mn(DPDP).
If not all of the labile hydrogens of the chelates are substituted by the complexed metal ion, biotolerability and/or solubility of the chelate may be increased by substituting the remaining labile hydrogen atoms with physiologically biocompatible cations of inorganic and/or organic bases or amino acids. Examples of suitable inorganic cations include Li + , K + , Na + and especially Ca 2+ . Suitable organic cations include ammonium, substituted ammonium, ethanolamine, diethanolamine, morpholine, glucamine, N,N,-dimethyl glucamine, lysine, arginine or ornithine.
A particularly preferred use of the compounds herein described, in particular the chelating agents and their metal chelates, is as cardio-protective agents and such use extends not only to use in conjunction with drugs having cardiotoxic side effects, but also to the treatment or prevention of pathological conditions in which the heart is at risk. Thus, for example, the compounds in accordance with the invention may be used in the prevention or treatment of the cardiotoxic side effects of anti-tumour drugs, in particular the toxicity of anthracyclines, such as doxorubicin, and the toxicity of paclitaxel. In this regard, the compounds of the invention may be administered as a combined preparation with the anti-tumour drug. Alternatively, they may be administered separately, prior to, during or subsequent to administration of the anti-tumour drug.
As used herein the term "anthracyclines" includes natural and semi-synthetic anthracyclines, e.g. epirubicin, idarubicin, daunorubicin and, in particular, doxorubicin and salts thereof, as well as synthetic anthracyclines, e.g. mitoxantrone, and salts thereof.
Viewed from a further aspect the invention thus provides a pharmaceutical composition comprising a chelating agent according to the invention or a metal chelate or salt thereof, together with one or more anthracyclines, e.g. doxorubicin, and/or paclitaxel, and at least one pharmaceutically acceptable carrier or excipient.
Viewed from a yet still further aspect the invention provides a pack containing a chelating agent according to the invention or a metal chelate or salt thereof and separately an anthracycline and/or paclitaxel for simultaneous, separate or sequential use in anti-tumour therapy.
In another aspect the invention provides the use of a chelating agent according to the invention or a metal chelate or salt thereof together with one or more anthracyclines and/or paclitaxel in the manufacture of medicaments for simultaneous, separate or sequential administration in anti-tumour therapy.
In relation to the use of paclitaxel as the anti-tumor agent, it is preferable that patients are premedicated with steroids, antihistamines and/or H 2 -antagonists to avoid hypersensitivity reactions, in particular anaphylactic reactions. Furthermore, myelotoxicity associated with paclitaxel administration, particularly with high doses of paclitaxel, can be substantially reduced by co-administration of granulocyte-colony stimulating factor (G-CSF), preferably given as a daily injection up to 24 hours after paclitaxel administration.
The compounds of the invention may be prepared by methods known in the art. Suitable methods for preparing the amino polycarboxylic acid based chelating agents are described in EP-A-299795, EP-A-71564, DE-A-3401052, EP-A-203962 and EP-A-436579.
In preparing the dipyridoxyl compounds, the compound PLED may e used as a starting material and may be appropriately derivatised using conventional procedures to obtain the compounds of formula I.
Suitable methods for preparing the compounds of formula I are described for example in EP-A-290047.
Alternatively the compounds of formula I may be prepared by reacting the corresponding pyridoxal compound with an alkylene diamine according to the procedure for making PLED described by Taliaferro (supra).
Alternatively, the compounds in accordance with the invention may be prepared by a process comprising one or more of the following steps:
(a) reacting a compound of formula II ##STR2## with a diamine of formula (III)
H.sub.2 N--R.sup.3 --NH.sub.2 (III)
(wherein R 3 and R 4 are as hereinbefore defined and R 2 ' is an optionally protected group R 2 as hereinbefore defined)
(b) hydrogenating a compound of formula (IV) obtained in step (a) ##STR3## (wherein R 3 .sub., R 4 and R 2 ' are as hereinbefore defined) (c) reacting a compound of formula (V) ##STR4## (wherein R 3 .sub., R 4 and R 2 are as hereinbefore defined) with a haloacetic, preferably bromoacetic, acid, and if necessary removing any protecting groups used; and
(d) converting a compound of formula I into a chelate complex or salt thereof.
Pyridoxyl phosphate, pyridoxal and the other compounds of formula II and the alkylene diamine, cycloalkylene diamine and arylene compounds of formula III are well-known compounds readily available or can be readily synthesised by procedures well known in the art.
The reaction of step (a) may conveniently be performed in a suitable solvent, such as an alcohol (e.g. methanol) at a temperature in the range of from 0 to 60° C.
To obtain compounds of formula I where the R 2 groups are the same, a diamine of formula III may be reacted with two molar equivalents of a compound of formula II. For the preparation of compounds of formula I where the R 2 groups are different, the diamine of formula III is first reacted with a first compound of a formula II having a desired R 2 ' group, and the reaction product thereby obtained is then reacted with a second compound of formula II bearing a different R 2 ' group.
The hydrogenation of step (b) may be performed using conventional procedures, e.g. using a palladium or platinum catalyst.
The metal chelates for use in accordance with the invention may be formed by conventional procedures known in the art. In general, such processes involve disssolving or suspending a metal oxide or metal salt (e.g. nitrate, chloride or sulfate) in water or a lower alcohol such as methanol, ethanol, or isopropanol. To this solution or suspension is added an equimolar amount of the chelating agent in water or a lower alcohol and the mixture is stirred, if necessary with heating moderately or to the boiling point, until the reaction is completed. If the chelate salt formed is insoluble in the solvent used, the reaction product is isolated by filtering. If it is soluble, the reaction product is isolated by evaporating to dryness, e.g. by spray drying or lyophilising.
If acid groups such as the phosphoric acid groups are still present in the resulting chelate, it is advantageous to convert the acidic chelate salt into a neutral chelate salt by reaction with inorganic and/or organic bases or amino acids, which form physiologically acceptable cations, and to isolate them.
The carboxylic and phosphoric acid groups of the chelating agents can also be neutralised by esterification to prepare carboxylate and phosphate esters. Such esters can be prepared from the corresponding alcohols by conventional procedures known in the art. Suitable esters include, for example, esters of straight-chained or branched alcohols having from 1 to 18 carbon atoms, mono and polyhydric alkyl amino alcohols having from 1 to 18 carbon atoms, preferably having from 1 to 6 carbons, such as serinol or diethanolamine, and polyhydric alcohols having from 1 to 18 carbon atoms, such as ethylene glycol or glycerol.
Where the metal chelate carries an overall charge it will conveniently be used in the form of a salt with a physiologically acceptable counterion, for example an ammonium, substituted ammonium, alkali metal or alkaline earth metal (e.g. calcium) cation or an anion deriving from an inorganic or organic acid. In this regard, meglumine salts are particularly preferred.
The therapeutic agents of the present invention may be formulated with conventional pharmaceutical or veterinary formulation aids, for example stabilizers, antioxidants, osmolality adjusting agents, buffers, pH adjusting agents, etc. and may be in a form suitable for parenteral or enteral administration, for example injection or infusion or administration directly into a body cavity having an external escape duct, for example the gastrointestinal tract, the bladder or the uterus. Thus the agent of the present invention may be in a conventional pharmaceutical administration form such as a tablet, capsule, powder, solution, suspension, dispersion, syrup, suppository, etc. However, solutions, suspensions and dispersions in physiologically acceptable carrier media, for example water for injections, will generally be preferred.
The compounds according to the invention may therefore be formulated for administration using physiologically acceptable carriers or excipients in a manner well-known to those skilled in the art. For example, the compounds, optionally with the addition of pharmaceutically acceptable excipients, may be suspended or dissolved in an aqueous medium, with the resulting solution or suspension then being sterilized. Suitable additives include, for example, physiologically biocompatible buffers (e.g. tromethamine hydrochloride), additions (e.g. 0.01 to 10 mole percent) of chelants (such as, for example, DTPA, DTPA-bisamide or non-complexed chelants of formula I) or calcium chelate complexes (e.g. calcium DTPA, CaNaDTPA-bisamide, calcium salts or chelates of chelants of formula I), or, optionally, additions (e.g. 1 to 50 mole percent) of calcium or sodium salts (e.g. calcium chloride, calcium ascorbate, calcium gluconate or calcium lactate combined with metal chelate complexes of chelating agents according to the invention and the like).
If the compounds are to be formulated in suspension form, e.g., in water or physiological saline for oral administration, a small amount of soluble chelate may be mixed with one or more of the inactive ingredients traditionally present in oral solutions and/or surfactants and/or aromatics for flavouring.
The preferred mode for administering the metal chelates in accordance with the invention is parenteral, e.g. intravenous administration. Parenterally administrable forms, e.g. intravenous solutions, should be sterile and free from physiologically unacceptable agents, and should have low osmolality to minimize irritation or other adverse effects upon administration, and thus the compositions should preferably be isotonic or slightly hypertonic. Suitable vehicles include aqueous vehicles customarily used for administering parenteral solutions such as Sodium Chloride Injection, Ringer's Injection, Dextrose Injection, Dextrose and Sodium Chloride Injection, Lactated Ringer's Injection and other solutions such as are described in Remington's Pharmaceutical Sciences, 15th ed., Easton: Mack Publishing Co., pp. 1405-1412 and 1461-1487 (1975) and The National Formulary XIV, 14th ed. Washington: American Pharmaceutical Association (1975). The solutions may contain preservatives, antimicrobial agents, buffers and antioxidants conventionally used for parenteral solutions, excipients and other additives which are compatible with the chelates and which will not interfere with the manufacture, storage or use of the products.
The therapeutic agent in accordance with the invention, if in solution, suspension or dispersion form, will generally contain the chelant or metal chelate at a concentration in the range of from 0.0001 to 5.0 moles per liter, preferably 0.01 to 0.1 moles per liter. If convenient, the therapeutic agent may however be supplied in a more concentrated form for dilution prior to administration.
The therapeutic agent in accordance with the invention may conveniently be administered in amounts of from 10 -2 to 100 μmol of the compounds per kilogram of body weight, e.g. about 10 μmol per kg bodyweight.
The present invention will now be illustrated further by the following non-limiting Examples and with reference to the attached figures.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1-4 illustrate the effect of Doxorubicin on the contractile force of the mouse heart muscle following pre-treatment with MnDPDP.
FIG. 5 illustrates the effect of Doxorubicin on the contractile force of the mouse heart muscle following pre-treatment with MnPLED.
FIG. 6 illustrates the effect of Daunomycin on the contractile force of the mouse heart muscle following pre-treatment with MnDPDP.
DETAILED DESCRIPTION OF THE INVENTION
EXAMPLE 1
The protective effects of dexrazoxane, manganese chloride, DPDP, MnDPDP and ZnDPDP against doxorubicin were tested in the mouse left atrium model.
Method
Male mice were killed, the left atrium carefully dissected out, and hung in an organ bath filled with 37° C. Krebs Henseleit solution. Contractility was measured with a force transducer as described by van Acker et al. (Phlebology Suppl. 1: 31-32 (1993)). After equilibration, the atrium was preincubated with saline or various concentrations of MnDPDP for 30 minutes. Saline or 120 μM doxorubicin was subsequently added and the contractility measured for 60 minutes. Thereafter isoprenaline was added to test the capacity for positive inotropic action.
In another series of experiments male mice were injected intravenously with various doses of saline, dexrazoxane, manganese chloride, MnDPDP, ZnDPDP and DPDP. Fifteen or 30 minutes later the mice were killed and the in vitro part of the experiments was conducted as described above.
Results
Typical results are shown in FIGS. 1-4 attached hereto, and tabulated in Tables 1 and 2 below.
It can be seen that untreated controls (saline addition) contract to almost 100% of original force during the 60 minute measurement period, whereas the atria treated with doxorubicin display a marked negative inotropic effect, presumably due to the damage to isolated atrial muscle, leading to approx. 60% reduction in contractile force within 60 minutes.
It is clear from FIGS. 1-3 that the manganese compound MnDPDP, when added directly into the organ bath, does not protect the heart muscle from deleterious effects of doxorubicin. However, it is clear from FIG. 4 that MnDPDP, when injected into the animal before the heart muscle is removed and placed in the organ bath, unexpectedly protects the heart muscle from the deleterious effects of doxorubicin. From Tables 1 and 2 it can be seen that either 15 or 30 minute pretreatment of the animal produces a 40-48% protection of the contractility. Equimolar doses of either manganese (as the chloride) or DPDP alone, although less effective still provide a degree of protection of the atrial muscle. The Zinc complex ZnDPDP also produced protective effects.
The reference compound dexrazoxane also protected against doxorubicin-induced cardiotoxicity in this test, although the quantities required were much larger (25-50 mg/kg·dexrazoxane=93-186 μmole/kg) compared to the effective doses of MnDPDP (1-10 μmole/kg).
TABLE 1______________________________________Protective effects of compounds againstDoxorubicin-induced CardiotoxicityCompound injected 15 minutes before removal of cardiactissueCompound Tested % protection*______________________________________Saline control 0 1 μmole/kg MnDPDP 16 10 μmole/kg MnDPDP 40 30 μmole/kg MnDPDP 4100 μmole/kg MnDPDP 0______________________________________ *% protection is defined as % evaluation of contractile force when compared to doxorubicin + saline control.
TABLE 2______________________________________Protective effects of compounds againstDoxorubicin-induced CardiotoxicityCompounds injected 30 minutes before removal of cardiac tissueCompounds Tested % protection*______________________________________Saline control 0 1 μmole/kg MnDPDP 35 10 μmole/kg MnDPDP 48 30 μmole/kg MnDPDP 2 1 μmole/kg DPDP 6 10 μmole/kg DPDP 15 30 μmole/kg DPDP 10 1 μmole/kg ZnDPDP 23 10 μmole/kg ZnDPDP 33 30 μmole/kg ZnDPDP 6 1 μmole/kg MnCl.sub.2 17 10 μmole/kg MnCl.sub.2 21 30 μmole/kg MnCl.sub.2 28 25 mg/kg dexrazoxane 43 50 mg/kg dexrazoxane 47100 mg/kg dexrazoxane 0______________________________________ *% protection is defined as % evaluation of contractile force when compared to doxorubicin + saline control.
EXAMPLE 2
The protective effects of saline, MnPLED, MnEDTA, MnDTPA.BMA, MnDTPA, EDTA and DTPA against doxorubicin were tested in another set of experiments.
Method
Male mice were injected intravenously with saline, 0.1 μmol/kg MnPLED, 10 μmol/kg MnEDTA, 10 μmol/kg MnDTPA.BMA, 10 μmol/kg MnDTPA, 10 μmol/kg EDTA or 10 μmol/kg DTPA.
Thirty minutes later the mice were killed, the left atrium carefully dissected out, and hung in an organ bath filled with 37° C. Krebs Henseleit solution. Contractility was measured as described in Example 1. After equilibration, saline or 60 μM doxorubicin was added and the contractility measured for 60 minutes.
Results
Typical results are shown in FIG. 5 attached hereto, and tabulated in Table 3 below.
It can be seen that atria treated with doxorubicin display a marked negative inotropic effect, presumably due to the damage to isolated atrial muscle, leading to approx. 60% reduction in contractile force within 60 minutes.
It is clear from FIG. 5 that 0.1 μmol/kg MnPLED, when injected into the animal before the heart muscle is removed and placed in the organ bath, protects the heart muscle from the deleterious effects of doxorubicin. From Table 3 it can be seen that 30 minute pretreatment with 0.1 μmol/kg MnPLED produces 56% protection of the atrial muscle, i.e. MnPLED is a ca. 100-fold more potent protector than MnDPDP (see Example 1). Pre-treatment with MnEDTA, MnDTPA, MnDTPA.BMA, EDTA and DTPA provide 42, 100, 12, 9 and 0% protection respectively. Whereas most of the tested manganese compounds gave effective protection, it is clear that equimolar doses of either EDTA or DTPA alone gave little or no protection.
TABLE 3______________________________________Protective effects of compounds againstDoxorubicin-induced CardiotoxicityCompounds injected 30 minutes before removal of cardiac tissueCompounds Tested % protection*______________________________________Saline control 0 (n = 7) 0.1 μmol/kg MnPLED 56 (n = 3)10 μmol/kg MnEDTA 43 (n = 6)10 μmol/kg MnDTPA 100 (n = 3)10 μmol/kg MnDTPA.BMA 12 (n = 3)10 μmol/kg EDTA 9 (n = 5)10 μmol/kg DTPA 0 (n = 3)______________________________________ *% protection is defined as % evaluation of contractile force when compared to doxorubicin + saline control.
EXAMPLE 3
The protective effect of MnDPDP against daunomycin was tested in the mouse left atrium model.
Method
Male mice were injected intravenously with saline or 10 μmol/kg MnDPDP.
Thirty minutes later the mice were killed, the left atrium carefully dissected out, and hung in an organ bath filled with 37° C. Krebs Henseleit solution. Contractility was measured as described in Example 1. After equilibration, saline or 60 μmol/kg daunomycin was added to the organ bath and the contractility was measured for 60 minutes. Isoprenalin was added subsequently to test the tissue capacity for positive inotropic action.
Results
The results are shown in FIG. 6 attached hereto.
It can be seen that the untreated control (saline addition) contracted to almost 100% of original force during the 60 minute measurement period, whereas the muscles treated with daunomycin showed negative inotropic effects, leading to approx. 40% reduction of contractile force within 60 minutes. Pretreatment with 10 μmol/kg MnDPDP resulted in approx. 100% protection. | 4y
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FIELD OF THE INVENTION
This invention relates to the fabrication of semiconductor devices. More particularly, this invention relates to selective deposition of silicon oxide onto silicon substrates.
BACKGROUND OF THE INVENTION
Optimization of semiconductor fabrication sometimes requires a thicker nonconducting film on some components than on other components. For example, a thick oxide layer or spacer on a P-type silicon wordline may be desired because the boron implants diffuse readily to an adjacent layer. In contrast, an N-type polysilicon component may optimally require a thinner oxide layer or spacer since N-type dopants do not diffuse as readily. A simple process that provides different thickness nonconducting films and spacers is desired in semiconductor fabrication.
Forming oxide layers and spacers of different thicknesses over varying silicon substrates using current methods requires the application of a first mask over select parts of the semiconductor device and then depositing a layer of silicon oxide over the unmasked parts of the semiconductor device. The first mask is then removed and a second mask is applied over the parts that have been coated with the first silicon oxide layer leaving other parts unmasked. Subsequently, a second silicon oxide layer is deposited on the unmasked parts. Finally, an etch is used to remove silicon oxide from select surfaces, leaving behind an oxide layer or spacers where desired. This process adds a number of steps to the manufacturing procedures thereby increasing the complexity of the fabrication. As such, semiconductors are typically manufactured oxide with oxide layers or spacers of an intermediate thickness that will work acceptably, although not optimally, for either P-type or N-type polysilicons substrate.
A hallmark of the current invention is the provision of a process that selectively deposits silicon oxide based on the conductivity type of the underlying silicon substrate.
SUMMARY OF THE INVENTION
The current invention is a method for selectively depositing silicon oxide onto a silicon-comprising surface wherein the selectivity is based on the conductivity type of the silicon. In one embodiment, the invention is a semiconductor processing method for selectively depositing silicon oxide onto silicon, the method comprising the steps of: (i) providing a silicon-comprising substrate having exposed regions of different type conductivity; (ii) contacting the substrate with ozone and tetraethylorthosilicate (TEOS) gases; and, (iii) reacting the ozone and TEOS in contact with the substrate to selectively deposit silicon oxide onto the substrate, such that, compared to the deposition rate on exposed regions of non-doped silicon, the silicon oxide deposits at a faster rate on exposed regions of P-type silicon and at a slower rate on exposed regions of N-type silicon.
Another embodiment of the invention is a method for forming an oxide layer of varying thickness on a silicon-comprising substrate, the method comprising the steps of: (i) providing the silicon-comprising substrate having a surface and comprising at least a first and second region of different type conductivity; and (ii) depositing silicon oxide onto the substrate in a single process step, to form an oxide layer over the first and second conductivity regions; whereby oxide layer overlying the first conductivity region has a first thickness and the oxide layer overlying the second conductivity region has a second thickness that is greater than the first thickness.
Another embodiment of the invention is a semiconductor processing method of forming spacers of variable thickness, the method comprising providing a silicon-comprising substrate having a surface comprising at least one first P-type silicon structure or protrusion and at least one second structure or protrusion, provided that: (1) when the first protrusion comprises P-type or non-doped silicon, then the second structure or protrusion comprises either non-doped silicon or N-type silicon; and (2) when the first protrusion comprises non-doped silicon, then the second structure or protrusion comprises N-type silicon. Next, TEOS is decomposed with ozone to selectively deposit silicon oxide over the silicon surface and both the first protrusion and the second protrusion, such that a greater thickness of silicon oxide is deposited on the first protrusion than on the second protrusion. Finally, the deposited silicon oxide is etched to remove the oxide from select areas and leave silicon oxide as a layer or as formed spacers of variable thickness around the first protrusion and the second protrusion.
Another embodiment of the invention is a semiconductor processing method of forming wordlines with an oxide layer or formed spacers of variable thickness. The method of this embodiment comprises providing a silicon-comprising substrate having a surface comprising at least one first wordline comprising P-type silicon and at least one second wordline comprising N-type silicon. Next, TEOS is decomposed with ozone to selectively deposit silicon oxide over the substrate surface and over both the first wordline and the second wordline, such that a greater thickness of silicon oxide is deposited on the first wordline than on the second wordline. Then, the silicon oxide deposited on the substrate during the reaction step is etched to provide a silicon oxide layer or formed spacers of variable thickness around the first wordline and the second wordline.
Another embodiment of the invention is a semiconductor processing method of forming gates with spacers of variable thickness. The method of this embodiment comprises providing a silicon-comprising substrate having a surface comprising at least one first gate comprising P-type silicon-comprising material and at least one second gate comprising N-type silicon-comprising material. Next, TEOS is decomposed with ozone to selectively deposit silicon oxide over the substrate surface and over both the first gate and the second gate, such that a greater thickness of silicon oxide is deposited on the first gate than on the second gate. Then, the silicon oxide deposited on the substrate during the reaction step is etched to leave a silicon oxide layer or formed spacers of variable thickness around the first gate and the second gate.
Another embodiment of the invention is a memory device comprising at least a first wordline comprising P-type silicon-comprising material and at least a second wordline comprising N-type silicon-comprising material, wherein both the first wordline and the second wordline have nonconductive spacers comprising silicon oxide wherein the nonconductive layer or formed spacer for the first wordline is thicker than the nonconductive layer or spacer for the second wordline.
Another embodiment of the invention is a multi-gate semiconductor device comprising at least one gate comprising (i) P-type silicon-comprising material, (ii) at east one second gate comprising N-type silicon-comprising material and, (iii) layer or a nonconductive layer or formed spacers around each of the first and second gates, wherein the nonconductive layer or spacer is thicker for the first gate than for the second gate.
BRIEF DESCRIPTION OF THE DRAWINGS
Preferred embodiments of the invention are described below with reference to the following accompanying drawings, which are for illustrative purposes only. Throughout the following views, reference numerals will be used in the drawings, and the same reference numerals will be used throughout the several views and in the description to indicate same or like parts.
FIG. 1 is a bar graph comparing deposition rates and layer thicknesses for the selective deposition of TEOS decomposed by ozone on silicon-comprising substrates that have different conductivities.
FIG. 2 is a cross-sectional view of a silicon-comprising substrate having an N-type silicon-comprising protrusion and a P-type silicon-comprising protrusion.
FIG. 3 shows the substrate of FIG. 2 following selective depositing of silicon oxide.
FIG. 4 shows the substrate of FIG. 3 following an etch processing step.
FIG. 5 shows a scanning electromicrograph (SEM) of a silicon substrate demonstrating the selective deposition of silicon oxide onto silicon substrates of different conductivity types.
DETAILED DESCRIPTION
In the following detailed description, references are made to the accompanying drawings which 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 and that structural, logical and electrical changes may be made without departing from the spirit and scope of the present invention.
The terms “wafer” or “substrate” used in the following description include any semiconductor-based structure having an exposed polysilicon or other silicon-comprising surface in which to form the silicon oxide deposition layer of this invention. Wafer and substrate are to be understood as including silicon-on-insulator (SOI) or silicon-on-sapphire (SOS) technology, doped and undoped semiconductors, epitaxial layers of silicon supported by a base semiconductor foundation, and other semiconductor structures. Furthermore, when references made to a wafer or substrate in the following description, previous process steps may have been used to form regions or junctions in the base semiconductor structure or foundation.
FIG. 1 is a bar graph showing selective deposition of silicon oxide using ozone/TEOS on silicon that has been doped with an N-type dopant (arsenic; center bar) or a P-type dopant (boron; right bar) or not doped (left bar). The substrate is composed of a single crystal silicon wafer, which has been implanted with the specified dopant. The surface was subjected to a hydrogen fluoride dip prior to the ozone/TEOS deposition processing. A blanket layer of silicon oxide was deposited on the wafer surface by ozone decomposition of TEOS at a temperature of about 400° C. and a pressure of about 300 torr. Under these reaction conditions, about five liters per minute of oxygen, containing about 10% by weight ozone, and about 350 milligrams per minute of TEOS were supplied to the deposition vessel.
As shown in FIG. 1, a P-type implant, in this case boron difluoride, in a silicon-comprising substrate (polysilicon) obtains a higher deposition rate (approximately 22% faster) of oxide and reaches a greater deposition thickness for a given time than non-doped silicon. In contrast, an N-type implant, in this case arsenic, in a silicon-comprising substrate (polysilicon) retards the deposition rate (approximately 14% slower) of oxide as compared to non-doped silicon and results in a lower thickness. Similar results are obtained when the N-type implant is phosphorous. As such, the oxide deposits approximately 33% faster on P-type silicon than on N-type silicon. The selectivity effect is more pronounced at higher concentrations of dopant. Additionally, the selectivity increases as the reaction temperature decreases and/or the reaction pressure increases.
FIGS. 2-4 shows a typical embodiment of the process of this invention, in which two non-abutting structures or protrusions 21 , 22 are arrayed on a silicon-comprising substrate 20 such as single crystal silicon, epitaxial silicon or polysilicon. Protrusion 21 has a P-type doped silicon layer 23 . Protrusion 22 has an N-type doped silicon layer 24 . Protrusions 21 and 22 each have a metalized film 25 , such as tungsten silicide, arrayed atop the doped polysilicon layers 23 and 24 , respectively.
The substrate 20 (single crystal) and protrusions 21 and 22 are contacted with gaseous ozone and gaseous TEOS under conditions where a silicon oxide layer 30 is deposited over the substrate and protrusions as shown in FIG. 3 . At the proper reaction conditions, the silicon oxide will deposit selectively onto the substrate and protrusions in a single process step. The selectivity of this single process step avoids the necessity of masking and performing multiple photolithographic steps to form a suitably thick oxide layer or spacer 30 over the component layers of the protrusions 21 , 22 and the substrate 20 . As shown a thicker layer 26 is formed over the P-type layer 23 . An intermediate thickness layer 27 is deposited over non-doped silicon substrate 20 . A thinner layer 24 is deposited over the N-type silicon layer 24 . An intermediate thickness layer 29 is deposited over metalized silicide film layer 25 .
Appropriate reaction conditions for the selective deposition of silicon oxide over materials with different type doping is similar to the reaction conditions used in conventional methods to obtain selective deposition on silicon versus silicon nitride. Such reaction conditions are known in the art as shown in U.S. Pat. No. 5,665,644, incorporated herein by reference. Typically, the reaction temperature is greater than about 200° C. up to about 500° C., preferably up to about 400° C. Generally, the selectivity of the deposition is more pronounced at lower reaction temperatures. The reaction pressure is at least about 10 torr, preferably at least about 300 torr up to about atmospheric pressure, more preferably up to about 600 torr.
An exemplary reaction supplies about five liters per minute of oxygen containing about 10% by weight ozone and about 350 milligrams per minute TEOS. The oxygen: ozone ratio may typically vary from about 2 parts oxygen: 1 part ozone to about 20 parts oxygen: 1 part ozone. The ozone: TEOS ratio typically varies from about 0.5: 1 to about 200: 1. Reaction times will vary depending on the desired thickness of the deposited layer, generally about 2-3 minutes.
Optionally, the surface to receive the oxide layer may be wet cleaned in a dip prior to depositing the oxide layer. A hydrofluoric acid (HF) wet-clean dip provides a marginal enhancement of the selectivity of the deposition. Other wet-clean dips, such as sulfuric acid or non-fluorine type etchants, have not been found to enhance the selectivity of the deposition and may negatively affect the subsequent deposition.
Following the deposition of the oxide layer 30 , the portion of the oxide layer 27 overlying the substrate 20 is selectively etched to expose the substrate 20 , resulting in the structure of FIG. 4 having the oxide layers 26 , 28 remaining over the protrusions 21 , 22 , respectively. Any suitable oxide etching method may be used to remove the oxide layer 27 and expose the substrate 20 . Preferably, the method provides an anisotropic etch. Suitable etching methods include directional methods such as reactive ion etching (RIE). An exemplary etching process is by RIE using a mixture of carbon tetrafluoride (CF 4 ) at a flow of about 15 standard cubic centimeters per minute (sccm), and methylene trifluoride (CHF 3 ) at 25 sccm for thirty seconds at about 200 millitorr and a power of 100 watts.
In one preferred embodiment, the protrusions 21 , 22 of FIG. 2 represent wordlines of different conductivity. In this embodiment, layer 23 represents a wordline comprising P-doped silicon and layer 24 represents a wordline comprising N-doped silicon. These wordlines can be incorporated into a memory unit, such as a dynamic random access memory (DRAM), by any suitable means known in the art.
In another preferred embodiment of the invention, the protrusions 21 , 22 represent a dual gate structure. In this embodiment, layer 23 in FIG. 2 represents a gate comprising P-doped silicon and layer 24 represents a gate comprising N-doped polysilicon.
In another embodiment of the invention, blanket layers of oxide using ozone/TEOS deposition processing are deposited over a silicon substrate having differentially doped areas. FIG. 5 is a SEM photomicrograph showing a cross-section of a silicon substrate 100 upon which this invention has been enacted. A transistor 114 is disposed on the surface of the substrate 100 . The portion 102 of substrate 100 has been doped with a P-type conductivity enhancing dopant such as boron, and portion 104 of the substrate 100 has been doped with an N-type dopant such as phosphorus. The intermediate (dark) layer 106 immediately above the substrate 100 and the transistor 114 is an oxide layer 106 formed from an ozone/TEOS deposition. The outermost (white) layer 112 above the oxide layer 106 is a deposited titanium nitride cap layer. As shown in FIG. 5, the silicon oxide layer 106 deposited as a significantly thicker layer 108 over the P-type doped portion 102 of the silicon substrate 100 compared to the thinner layer 110 deposited over the N-type doped portion 104 of the silicon substrate 100 .
The methods and devices of the current invention are useful whenever semiconductors are fabricated with silicon-comprising regions or structures having different type conductivities. Examples of useful applications include memory arrays, such as DRAM and static random access memory (SRAM), logic circuitry, and combinations of memory and logic, such as a system-on-chip array.
In compliance with the statute, the invention has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the invention is not limited to the specific features shown and described, since the means herein disclosed comprise preferred forms of putting the invention into effect. The invention is, therefore, claimed in any of its forms or modifications within the proper scope of the appended claims appropriately interpreted in accordance with the doctrine of equivalents. | 4y
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CROSS REFERENCE TO RELATED APPLICATIONS
This is a continuation-in-part of application Ser. No. 08/413,666 filed Mar. 30, 1995 now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates primarily to faucets. More particularly, the invention relates to diverter valves for use with faucets having a spout outlet, a separate spray outlet and an antisiphonage feature.
2. Description of the Art
Hand spray functions in conjunction with kitchen faucets have been in existence for over fifty years. An outlet valve on a pull-out spray typically causes a water pressure change that activates a diverter valve to shut off flow to a spout while the spray is operating.
Prior art diverter valves for such purposes have shortcomings in that they have a tendency to clog with foreign particles. Even some designs which have incorporated by-pass paths to minimize clogging problems have difficulties with manufacturing tolerances. Most other diverters do not provide one hundred percent spout shut off. There is also the problem with prior art diverters in that they are difficult to assemble and/or machine. Others have installation problems into the valve body. Accessibility, complexity, and high costs have also been a problem. Further, there can be problems incorporating and providing sufficient antisiphonage protection in such systems.
SUMMARY OF THE INVENTION
In one aspect, the invention provides a faucet with a housing having a fluid inlet leading to a first cavity and a fluid outlet leading from the first cavity. A valve unit is positioned in the first cavity for regulating a flow of fluid between the inlet and outlet. The outlet has a first branch leading to a spout, a second branch leading to a spray member with a second cavity at the intersection of the two branches. A diverter valve is positioned in or adjacent the second cavity, the diverter valve having a sleeve in radial sealing engagement with the first branch, and having an axial passage through the sleeve. A valve member is operatively connected to the sleeve for reciprocal movement relative thereto, the valve member including a first head for opening and closing the passage through the sleeve in one direction. The valve member further includes a second head having a one way seal valve in sealing engagement with the second branch with the second head. Importantly, the second head is also constructed and arranged for positive contact with a valve seat on the sleeve.
When the spray member is closed, the first head is forced to move away from a sealing position and allow fluid flow to the spout. When the spray member is open, fluid pressure will cause the diverter valve to close off fluid from entry to the spout and allow fluid flow past the second head into the spray member. In the event of a pressure failure in the fluid inlet, reverse fluid flow from the spray is prevented from the spray to the second cavity by the one way seal sealing against a surface of the second branch with back-up protection afforded by the contact of the second head with the valve seat of the sleeve.
Preferably, the valve member includes a neck portion interconnecting the first and second heads. In another aspect, the second head is of a larger diameter than the first head. In yet another aspect, the valve has guide flanges for guiding reciprocal movement of the valve member in the sleeve. In another embodiment, the sleeve valve unit includes a waist having a reduced diameter portion with at least one opening positioned adjacent the second cavity.
The objects of the invention therefore include:
a. providing a diverter member of the above kind which reduces the risks of back siphonage without requiring check valves on the spray unit or line to the spray;
b. providing a diverter member of the above kind which can easily and efficiently be installed;
c. providing a diverter member of the above kind which can be manufactured with few parts and thus at reduced costs;
d. providing a diverter member of the above kind which can be easily assembled;
e. providing a diverter member of the above kind which affords complete shut off of a valve spout; and
f. providing a diverter member of the above kind which can be assembled or retrofitted into a variety of valve housings.
These and still other objects and advantages of the invention will be apparent from the description which follows. In the detailed description below, a preferred embodiment of the invention will be described in reference to the accompanying drawings. The embodiment does not represent the full scope of the invention. Rather the invention may be employed in other embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view showing a faucet employing the diverter valve of this invention;
FIG. 2 is an exploded perspective view of the diverter valve parts shown in FIGS. 3 and 5;
FIG. 3 is an enlarged sectional view taken along line 3--3 of FIG. 1 and showing the diverter valve in one mode of operation;
FIG. 4 is a sectional view taken along line 4--4 of FIG. 1; and
FIG. 5 is a view similar to FIG. 3 showing the diverter valve in another mode of operation.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 4, the diverter valve, generally 10, is shown in conjunction with a faucet, generally 12, having a housing 14 with a cavity 15. There are hot and cold water passages 16 and 17 in the housing 14 to supply hot and cold water to the cavity 15 such as by the cold water pipe 18. A cartridge valve 23 is seated in the cavity 15 and retained therein by the mounting nut 25 over which is placed the bonnet 26. Valve 23 is of the ceramic disk type having a stationary disk with hot and cold water passages extending therethrough and a movable disk operable by the stem 28. Stem 28 is connected to a handle 31 such as by the screw 27. Water flows from the valve 23 through the outlet orifice 30 and into outlet passage 29 where it enters a second and non-coaxial junction passage 33 in the valve housing 14. A valve sleeve 19 surrounds the valve body 14 and is sealed thereto by O-rings 20 and seals 21 and 22.
Referring to FIGS. 2-5, it is seen that junction passage 33 joins with a first outlet branch 35 and a second outlet branch 36. The diverter valve 10 is placed in the cavity 33 and has a sleeve 38 sealably engaged in the first branch 35 by the O-ring 47. The diverter valve 10 is held in position in housing 14 by the valve sleeve 19 and the projections 38a extending from sleeve 38 for retentive contact with an inwardly extending wall portion 19a. This retention is also aided by the frictional protrusions 28b on the sleeve 38. A poppet type valve member 42 has opposing piston heads 43 and 45 with head 43 having a seal member 44 connected thereto such as by the cap 41 frictionally engaged over the enlarged head 39. As shown specifically in FIG. 3, the seal member 44 is in sealing engagement with a valve seat 55 in the sleeve 38, adjacent the passage 40.
Valve member 42 has a neck portion 48 which connects the opposing piston heads 43 and 45. Guide flanges 52 extend from the neck portion 48 to provide a guide surface for the neck portion 48 in the sleeve 38. The sleeve 38 has a waist or reduced diameter portion 53 with opposing openings 32 and 46 which allows water to enter inside the sleeve 38. A seal member 51 is connected to the piston head 45 by the connector cap 58. It has a lip 59 for sealable engagement in the second outlet branch 36. A tapering wall 56 extends between wall 54 and the second outlet branch 36.
FIG. 5 shows the diverter valve in a spout open condition with water flowing from cartridge valve 23. In this instance the spray nozzle 57 is attached to a spray outlet line 66 communicating with the second outlet branch 36 by the passage 65 as seen in FIG. 4. The spray nozzle 57 would be closed. Water pressure builds in the cavity 33, thus forcing the valve member 42 to move to the right as viewed in FIG. 5, and thereby moves the seal member 44 away from the valve seat 55 and allows the flow of water to pass in the direction of the flow arrows. Water flows around the piston seal 44 from the sleeve 38, into a passage 60 in the valve body 14 and to the opposite side where, as seen in FIG. 1, it flows through the aperture 62 and ultimately into the spout 64 extending from sleeve 19.
In the instance where the spray nozzle 57 would be in an open condition, water flows through the spray outlet line 66. This condition would cause the valve member 42 to move to the left as viewed in FIG. 3, thus closing the pathway, including passage 40, through the sleeve 38 as the seal member 44 now sealably engages the valve seat 55. However, water is free to flow around the outside of piston head 45 and seal 51. This is effected by an inward deflection of the lip 59 as fluid flows from cavity 33 to passage 65 when the valve 10 is in a spray open condition.
Diverter valve 10 offers the advantage of an antisiphonage feature. This is effected by the seal 51 with lip 59. Back flow from spray nozzle 57 is prevented should it be left in dirty water and there is a loss of pressure in the water supply passages 16 and 17. An important feature of the invention is the sealing effected by seal 51 and lip 59 engaging the branch line 36 and the additional sealing effected by the abutment of the piston head 45 with the seat 61 of the sleeve 38. This serves as an additional closure.
It will therefore be appreciated that a diverter 10 is provided wherein a complete shut off of water is effected to the spout while the spray nozzle function is taking place. This is effected by the movement of the piston head 43 and the seal member 44 against the valve seat 55 in response to the fluid pressure on the larger piston head 45. In addition, there is an ease of assembly in that the valve member 42 is quickly assembled into the sleeve 38 and guide flanges 52 into the bore of the sleeve 38. The valve seal member 44 is then passed over the enlarged head 39 and the cap 41 secured thereon. This then captures the valve member 42 in the sleeve 38. Similarly seal member 51 is passed over enlarged piston head 45 and cap 58 secured thereon.
Still another feature of the diverter valve 10 is the simplified construction. It is composed of three rather simple injection molded pieces 42 and 38 with two elastomer seals 44 and 51, an O-ring 47 and caps 41 and 58.
Yet another feature of the valve of this invention is the design of the diverter in that it is easily placed into a faucet housing either manually or by an automatic assembly.
Thus, the invention provides an improved diverter member. While a preferred embodiment has been described above, it should be readily appreciated to those skilled in the art, that a number of modifications and changes may be made without departing from the spirit and scope of the invention. For example, while cap seal 51 has been shown as attached to valve member 42 by cap 58 it could be retained thereon by other fastening means such as a screw. Seal member 44 could be retained in a similar manner. Further, while a cup seal 51 has been described with a lip 59 in conjunction with piston head 45, the seal 51 could have other geometric configurations. Also, the specific materials mentioned are not the only materials which can be used. All such and other modifications within the spirit of the invention are meant to be in the scope thereof. | 4y
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BACKGROUND OF THE INVENTION
The present invention relates to plasma collection and, more particularly, to a device and method for separating and discharging plasma. The field of plasma collection plays an important role in analytical methods for determining a concentration of blood components. In many cases such blood tests cannot be carried out with whole blood since this contains corpuscular components (blood cells) which could result in an interference of the assay procedure. Hence, in order to carry out many analytical methods it is necessary to firstly isolate plasma from whole blood, which plasma should be as free as possible from cellular material.
A conventional method for isolating plasma for blood tests is the centrifugation procedure in which cellular components of the blood are separated on the basis of centrifugal forces. This method is laborious and is especially unsuitable when only small amounts of plasma are required for an analysis. However, particularly modern miniaturized tests use quantities of plasma that are only in the range of a few microliters. This applies especially to so-called carrier-bound tests in which an analytical system that is as small and compatible as possible is present, for example, in the form of a test strip. In this case all reagents and other agents required to carry out the test are integrated into the test strip. In order to determine an analyte the sample liquid is contacted with such an analytical element. The reagent contained in the test element reacts within a short period with the analyte to be determined such that a physically detectable change occurs on the analytical element. Such a change can, for example, be a colour change or a change in a measurable electrical variable. The change is measured and calculated with the aid of an evaluation instrument in order to output an analytical result.
An example of an analytical system which determines an analyte from plasma by means of such a test element is the HDL test (high density lipoproteins). The determination of the HDL concentration in blood is, among other things, important for the risk assessment of coronary heart disease and is thus in recent times used to diagnose one of the most common modern diseases.
The severity of a coronary heart disease can be assessed on the basis of several known parameters such as total cholesterol, in the blood, plasma or serum. Since the concentration of total cholesterol is of only limited use for individual risk assessment, the low density lipoproteins (LDL) and the high density lipoproteins (HDL) are quantified separately from one another in modern analytical methods. When assessing such analytical methods it must be taken into account that there is a positive correlation between LDL cholesterol and a coronary heart disease but a negative correlation between HDL cholesterol and the disease. Clinical studies have proven that, as a first approximation, the determination of HDL and total cholesterol is sufficient for a risk assessment. This is the preferred method in current diagnostic practice.
HDL cholesterol is, for example, determined by means of an analytical element such as those known in the prior art (e.g., HDL test elements from Roche Diagnostics GmbH). Since the HDL cholesterol is determined separately, the other lipoprotein classes that are present have to be separated from the remaining blood components to allow the determination of HDL cholesterol in plasma. Such a test, for example, requires a plasma volume of about 40 μl in order that the concentration can be determined independently of the applied plasma volume. Only pure plasma in which there are substantially no blood components can be used to determine HDL cholesterol. A complexing agent which is also integrated into the test element is additionally used to determine the HDL concentration. Plasma is then applied to the zone of the test element in which the complexing agent is present. The complexing agent EDTA is, for example, used in the prior art to analyze HDL cholesterol.
However, an analyte in pure plasma can also be determined by means of a test element that requires no completing agent to determine an analyte. Such test elements are, for example, used to determine enzymes and are described in the prior art in the document DE 3130749 among others. Test elements which determine an analyte in pure plasma but do not contain a complexing agent are often designed such that the test element itself separates plasma. For this purpose such test elements contain a separation layer in addition to a reagent layer. In order to measure an analyte whole blood is firstly applied to the separation layer. Blood components are separated from the plasma within the separation layer and the plasma is passed on to the reagent layer. In this manner an analyte can be determined in pure plasma although blood has been applied to the test element. However, such a plasma separation layer integrated into the test element cannot be used when using complexing agents. If a complexing agent is used to determine an analyte, it turns out that the complexing agent in the test element prevents the separation of plasma from blood. Hence, the test element can no longer separate plasma if the test element contains a complexing agent.
Since, on the one hand, a complexing agent is needed to determine HDL cholesterol by one of the test elements described above and, on the other hand, it is necessary to separate plasma from blood, it follows that the plasma has to be already separated from blood on a μl scale before applying blood to the test element.
In this connection the determination of HDL cholesterol is only one important example of an analyte determination which requires small amounts of pure plasma for analysis. Other fields of application for the use of released plasma are in the field of clinical analysis. Since test strips are currently preferably used in diagnostic practice as analytical systems, there is an increasing need for simple methods for obtaining small amounts of plasma in order to achieve an overall simplification and more rapid analytical procedure.
In this respect several methods have been described in the prior art which are intended to simplify the isolation of small amounts of plasma. The aim is to obtain plasma from likewise small volumes of blood to spare the patients a laborious blood withdrawal which would, for example, be required for a centrifugation method.
Filtration methods in which different filter media and in particular membrane and glass filters are used have been discussed for many years and in some cases have been used successfully. Earlier examples of filtration technology are described in U.S. Pat. Nos. 3,791,933 and 4,477,575. A recent example comprising a complicated combination of membrane and glass filters is described in U.S. Pat. No. 5,922,210. Small amounts of plasma are obtained by microfiltration with the aid of a microcomponent. The blood cells are separated by a so-called barrier channel which is too small to allow blood cells to flow through the barrier channel. However, manufacture of a device with such a channel requires special manufacturing processes which are complicated. The said plasma collection methods have the additional disadvantage that there is a high risk of the fine pores being clogged up by mechanical plugging or by accumulation of cellular material on the walls of the pores. This would reduce the filter capacity. However, an enlargement of the filter capacity would require more space for the filter medium. This would in turn have an unfavorable effect in relation to the applied sample volume and volume of plasma obtained.
A filtering process for collecting plasma is described in U.S. Pat. No. 4,477,575 which comprises a glass fiber layer which improves the relation between sample volume and the volume of plasma obtained. In this case the volume of plasma to be separated is preferably less than 30% of the suction volume of the glass fiber layer. The filtering process takes place after blood has been applied to the glass fiber layer and is driven solely by gravity and hence the plasma isolation is correspondingly time consuming.
In order to accelerate plasma collection other methods for collecting plasma have been described in the prior art. In the patent application EP 747105 a glass fiber onto which blood is applied is firstly stored in a vessel. Pressure is exerted by a plunger on the glass fiber and the blood contained therein to accelerate the filtration process. The blood is thus pressed through the glass fiber resulting in a separation of plasma from other blood components. The plasma is discharged via an outlet. However, a disadvantage of the described device is that large amounts of blood sample are required due to the filtering process. In addition, pressing out the glass fibers results in a destruction of the corpuscular blood components and hence it is not possible to obtain pure plasma.
A vessel for plasma collection, which is described in the patent application EP 0 785 012, is based on a similar principle. In this case pressure is also exerted on a filter material to which blood has previously been applied to allow plasma separation to occur. As already described above, the pressing out process destroys blood cells and hence pure plasma is not obtained. Once plasma has been contaminated by the destruction of blood cells, it is unsuitable for use in numerous analytical tests.
SUMMARY OF THE INVENTION
It is against the above background that the present invention provides certain unobvious advantages and advancements over the prior art. In particular, the inventors have recognized a need for improvements in devices and methods for separating and discharging plasma.
Although the present invention is not limited to specific advantages or functionality, it is noted that the device and method allows plasma that is as pure as possible to be obtained on a μl scale from whole blood.
In accordance with one embodiment of the present invention, a device for separating and discharging plasma is provided. The device comprises a separation element comprising a first zone on which blood is applied. Corpuscular blood components are substantially completely retained in the first zone of the separation element whereas plasma is passed into a second zone of the separation element, typically by means of capillary forces. The separation element is configured such that the first zone of the separation element is accessible to the user for blood application. The device also has a discharge unit which, after plasma separation, acts on the second zone of the separation element without having an effect on the first zone of the separation element that would, for example, lead to blood hemolysis. If the discharge units acts exclusively on the second zone of the separation element, the separated plasma is released from the second zone and discharged through an outlet of the device.
In accordance with another embodiment of the present invention, a system for detecting analytes in blood is provided. In addition to the device according to the present invention, the system, as already described, also comprises a test element which enables detection of an analyte in plasma when the plasma separated by the device is applied.
The device according to the present invention ensures an effective collection of plasma on a μl scale even from small sample volumes. For example, plasma volumes of 30 μl or more can be obtained from 100 μl blood. Hence, the device according to the present invention is particularly suitable for the field of modern analyses since it already enables a rapid plasma separation and discharge of the plasma onto a test strip even when only small volumes of sample are drawn. If the applied blood volume is typically 30 to 150 μl, the device according to the present invention can be used to obtain sufficient amounts of plasma that are specified for commercial test elements in order that an analyte concentration can be determined independently of the applied sample volume. Consequently, the device according to the present invention enables sufficiently large amounts of plasma to be obtained despite small blood volumes in order to meet the requirements of commercial analytical methods especially with test elements.
Furthermore, the device according to the present invention allows a particularly simple and cost-effective manufacture of the system since, for example, microstructures (microchannels) do not have to be integrated into the device in the manufacturing process. The plasma is separated by means of a separation element that is typically designed for single use. Thus, a blockage of the microporous structures due to multiple use and contamination can be avoided.
The present invention can also provide for the release of the plasma and the separation of the plasma from blood, which according to the invention, are carried out as two separate successive processes. Thus, it is possible to accelerate plasma collection without having to apply pressure on the sample during the separation process. According to the present invention, the plasma is released substantially only by means of an action on the second zone of the separation element whereby this process can be accelerated in any desired manner (e.g., by overpressure, negative pressure, or elution processes, etc.). The plasma separation step is substantially independent of this process and occurs independently of the release process and can, for example, also be accelerated by capillary forces which act inside the first zone of the separation element. However, care should be taken that acceleration of plasma separation should only occur to the extent that a reliable separation of plasma from other blood components is still ensured. In particular, processes which would cause hemolysis during plasma separation should be avoided (e.g., those which require shear forces). Consequently, the invention enables an accelerated plasma separation process without having to accept contamination of the plasma with other blood components.
In the field of modern analysis the present invention is particularly suitable for applying pure plasma to test elements that, as described, contain a complexing agent and therefore cannot themselves separate plasma within the test element due to the complexing agent.
However, an application for test elements which do not contain a complexing agent is also contemplated. Although the plasma can also be separated commercially by means of a separation layer in the test element and, consequently, the user does not have to rely on a separate plasma separation in order to use these test elements, the system according to the present invention allows a simplified test element construction in this case. Hence, the test elements only need to have a reagent layer and no longer need to be provided with a separation layer or separation fleece. This reduces, among others, the number of production steps which lowers the costs of the test elements.
Using the test elements with a separation layer or separation fleece described in the prior art as a basis, a typical embodiment of a separation element according to the present invention is constructed as a first approximation in a similar manner. Reference is, for example, made to the document DE 3130749 for a more detailed description of commercial test elements with a separation layer. The document describes a test element in which plasma is firstly separated from blood so that only plasma is transported to a reagent layer. The reagent is then used to determine an analyte in plasma. For this purpose the test element has a flat separation layer located on the base strip on which the blood sample is applied at one end. The separation layer is composed of glass fiber material which retains the blood cells near to the site of application. In contrast, blood plasma spreads in the layer in such a manner that a “plasma lake” is available in the area of the separation layer that is distant from the separation layer. A reagent layer is usually located above or below the plasma lake which can be subsequently used to determine an analyte in the plasma. Appropriate evaluation devices that are known in the prior art are used to evaluate such a test carrier.
However, a disadvantage of these analytical systems is that the so-called “plasma lake” collected in this manner can only be used on the described system. Hence, an analysis of analytes present in the plasma is only possible within the scope of the test carrier system since it is not possible to release plasma from the test carrier.
If a device according to the present invention contains a separation element which is designed like such a simplified test element, such a separation element, for example, comprises a separation layer in its first zone which is also referred to as a separation fleece in the following and it comprises a transport fleece in a second zone in which the plasma collects in an area that is distant from the separation layer. Consequently, a typical embodiment of the separation element has a test carrier-like, strip-like structure without a reagent layer being present. The separation element typically comprises a filter in its separation fleece which, for example, is composed of glass fiber material to ensure a substantially complete separation of plasma from blood. Other commercial fleeces are, for example, described in the document EP 0 045 476 or are commercially available under the name Whatman fleece. In this case, the filtering process according to the present invention is substantially not assisted by pressure to avoid destruction of blood cells in the first zone of the separation element. If, for example, negative pressure is applied to the first zone of the separation element to assist the filtration process, then care should be taken that pressure is only exerted to an extent that does not cause hemolysis.
Plasma is then subsequently released by an action on the second zone of the separation element without influencing the first zone of the separation element. Thus, according to the present invention, a contamination of the plasma by the process step of plasma release is prevented.
Pressure is typically applied to the second zone of the separation element in order to release plasma such that plasma is pressed out of the second zone of the separation element. If plasma is pressed out of the separation element care should be taken that pressure is only exerted on the second zone of the separation element in which there are no more blood components to avoid hemolysis. In principle, a variety of methods are contemplated for releasing the plasma whereby the process step of plasma release takes place according to the invention independently of the plasma separation so that the plasma separation step does not impose any constraints on the plasma release. Another example of plasma release is to elute the separated plasma. The released plasma is subsequently discharged in a dosed manner through an outlet of the device.
It has also proven to be advantageous for the release of the plasma when forces for releasing the plasma act on the second zone of the separation element substantially perpendicularly to the plane in which the separation element is located. This ensures that there is no effect on the first zone of the separation element which could otherwise contaminate the released plasma with the other blood components.
In this connection, an embodiment using a plunger is contemplated in which the plunger is arranged within the device above or below the plane in which the second zone of the separation element is located. Hence, pressing the plunger against the separation element only exerts pressure on the second zone of the separation element and thus plasma is released.
It is also contemplated that the second zone of the separation element is firstly separated from the first zone of the separation element in order to ensure the release of pure plasma so that, for example, the separation element zones can be spatially separated. In this case it is advantageous to take care that the second zone is only separated from the first zone at the site of the separation element in which substantially only plasma is present so that no corpuscular components can contaminate the plasma in the second zone of the separation element. The spatial separation now allows the plasma to be released in a variety of manners without the risk of affecting the first zone.
The second zone of the separation element can, for example, be separated from the first zone by a holder which is connected to the second zone of the separation element. If the user exerts a force (e.g., pulling, pressing, twisting, etc.) on this holder this force is directly or indirectly transferred to the second zone of the separation element and thus results in a detachment of the second zone. For example, it is possible that a rotation of the holder by typically about 90° detaches the second zone from the first zone which is fixed in a permanent position within the device.
In another embodiment, the separation element is detached and the plasma is subsequently released from the second zone in two successive steps which are carried out by actuating the same trigger unit on the device. Such a trigger unit is then linked to the holder of the device in such a manner that when the trigger unit is actuated first it initially results in a severing of the element and another actuation of the trigger unit results in plasma release. Trigger units can be in the form of a release button which in a first step, for example, causes a rotation of a holder which is connected to the second zone of the separation element resulting in a rotation of this separation element. During the rotation of the second zone attached to the holder the first part of the separation element remains in a permanent position in the device. The forces exerted by the rotation result in a severing of the separation element. In this case it is, for example, contemplated that a cutting element is positioned in the device in such a manner that the second zone of the separation element is pressed against the cutting element during the rotation. This facilitates a severing of the separation element and can be carried out precisely. If a cutting element is omitted the separation element can also be severed by tearing the first zone from the second zone. Subsequently, the plasma is released by the discharge unit.
If the separation element is designed as a single-use article in an embodiment of the device, an irreversibly severing of the element is not disadvantageous; it is also possible to offer the holder as a single-use article that is permanently connected to the separation element. This would greatly simplify the handling of the devices for the user when reinserting a new separation element since especially older persons have difficulties in handling small instrument components. Moreover, the holder and separation element can be stored in a dispenser which dispenses individual units of the single-use article.
In accordance with yet another embodiment of the present invention, a method for separating and discharging plasma is provided. The method comprises applying blood to a first zone of a separation element which comprises a first and a second zone. The plasma is separated from other blood components by the separation element during which the plasma is passed into the second zone of the separation element and the remaining blood components are substantially retained in the first zone of the separation element. Subsequently, the second zone of the separation element is processed in such a manner that plasma is released from the second zone of the separation element. In this connection, no processing of the first zone of the separation element should occur which would cause plasma to be contaminated with previously separated blood components by, for example, hemolysis. The released plasma is discharged through an outlet of the device.
Embodiments of the method of the present invention are derived as described. The method for plasma separation and discharge is typically carried out by means of the device of the present invention, as described herein.
The device according to the present invention and the method according to the present invention consequently allow a simple and rapid separation of plasma from blood on a microliter scale. The device is convenient to handle and can be manufactured economically.
These and other features and advantages of the present invention will be more fully understood from the following detailed description of the invention taken together with the accompanying claims. It is noted that the scope of the claims is defined by the recitations therein and not by the specific discussion of features and advantages set forth in the present description.
BRIEF DESCRIPTION OF THE DRAWINGS
The following detailed description of the embodiments of the present invention can be best understood when read in conjunction with the following drawings where like structure is indicated with like reference numerals and in which:
FIG. 1 is a schematic illustration of a separation element shown in accordance with one embodiment of the present invention;
FIGS. 2 a )- c ) are schematic illustrations of a device for separating and discharging plasma shown in accordance with another embodiment of the present invention; and
FIGS. 3 a )- c ) are schematic illustrations of a device for separating and discharging plasma with a rotatably pivoted holder shown in accordance with yet another embodiment of the present invention.
Skilled artisans appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of embodiment(s) of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring initially to FIG. 1 , an example of the construction of a separation element ( 1 ) in accordance with one embodiment of the present invention, is illustrated. The separation element ( 1 ) comprises a transport fleece ( 2 ) which, for example, consists of glass fibers. A separation fleece ( 3 ) which is composed of a filter medium is mounted on the transport fleece ( 2 ). The main difference between the transport and the separation fleece is their different densities. In the prior art a density of 77 g/cm 2 is, for example, given for a separation fleece and 53 g/cm 2 for a transport fleece (Whatman fleece). The smaller thickness of the transport fleece allows a rapid transport of the sample along the fleece whereas the larger thickness of the separation fleece ensures a reliable separation of plasma from blood. When a blood drop ( 5 ) is applied, the blood enters the separation fleece ( 3 ). The filter medium in the separation fleece separates the blood components from the plasma and retains them in the separation fleece ( 3 ). The plasma can be passed on by means of capillary forces which act within the transport fleece. In this case it has been often observed that small concentrations of blood components from the separation fleece ( 3 ) can enter a small area of the transport fleece ( 2 ) due to capillary forces. This area is referred to as a transition zone ( 6 ) and does not contain pure plasma. In an embodiment of the inventive device, the discharge unit therefore does not act on the transition zone of the transport fleece during release of the plasma in order to avoid contamination of the remaining plasma with impurities that are contained therein. As shown in FIG. 2 , the transition zone is avoided by, for example, detaching the second zone of the test element from the first zone on the other side of this transition zone to ensure that pure plasma is obtained.
FIGS. 2 a ) to c ) are examples of a method for plasma separation using a device ( 10 ) according to another embodiment of the present invention. The device comprises a hollow body ( 14 ) which is provided with an outlet ( 13 ). The separation element ( 1 ) is arranged within the hollow body ( 14 ) in such a manner that the separation fleece ( 3 ) protrudes from the hollow body ( 14 ) and is easily accessible for the user. The transport fleece ( 2 ) is located within the hollow body ( 14 ). The device also comprises a plunger ( 12 ) which is movably mounted within the device ( 14 ). The radius of the plunger ( 12 ) is substantially identical to the inner radius of the hollow body ( 14 ) such that the plunger ( 12 ) can be moved by means of a button ( 11 ) within the device. FIG. 2 b ) shows application of blood ( 5 ) on a separation fleece ( 3 ) of a separation element ( 1 ). If the blood enters the separation fleece, the plasma is passed along the separation fleece whereas the remaining blood components are retained in the separation fleece. A complete plasma separation occurs after about 2 to 10 sec. The separated plasma is now transported into the transport fleece ( 2 ). Actuation of the button ( 11 ) firstly presses the plunger ( 12 ) against the transport fleece ( 2 ) such that this area of the separation element is swept along by the plunger within the hollow body ( 14 ). Since the separation fleece ( 3 ) is permanently positioned in the hollow body, this results in a detachment of the transport fleece from the separation fleece whereby it is severed on the other side of the transition zone ( 6 ) shown in FIG. 1 . Further actuation of the button ( 11 ) presses the separated transport fleece ( 2 ) against the wall ( 16 ) of the housing ( 14 ). In this process the plunger ( 12 ) presses the plasma out of the transport fleece ( 2 ) and releases it. Subsequently, plasma ( 7 ) is discharged from the outlet ( 13 ) of the device. The plasma can then, for example, be applied to a test element ( 17 ) to determine the HDL concentration.
FIG. 3 shows various views of another embodiment of the device (a-c). Compared to the embodiment shown in FIG. 2 , the device additionally comprises a rotatably pivoted holder ( 21 ) in which a separation element ( 1 ) is positioned within a channel ( 23 ). The separation element ( 1 ) is positioned in the holder in such a manner that the separation fleece ( 3 ) protrudes outside the holder and device in such a manner that it is readily accessible for blood application by the user as illustrated by the side-views. The device is also provided with a plunger ( 12 ) which is connected with the button ( 11 ). Furthermore, the button ( 11 ) can operate a rotating element ( 22 ). Firstly, blood is applied to the separation fleece ( 3 ) of the separation element ( 1 ) as shown in side-view in FIG. 3 a ). After the plasma has been separated from blood, the rotating element ( 22 ) is operated by a first pressing of the button ( 11 ). The holder ( 21 ) is rotated by about 90° by a downwards movement Of the rotating element ( 22 ). This detaches the separation fleece ( 3 ) from the transport fleece ( 2 ) during which the transition zone ( 6 ) of the transport fleece ( 2 ) remains attached to the separation fleece ( 3 ). Further actuation of the button ( 11 ) results in the plunger ( 12 ) which is firstly within a channel ( 23 a ) being transferred into the channel region ( 23 b ). This presses together the transport fleece against a sieve ( 24 ) located in the outlet ( 13 ). The sieve ( 24 ) typically has a small thickness of 20 to 300 μm in order to avoid an excessive dead volume. The plasma is discharged through the outlet ( 13 ).
It is noted that terms like “preferably”, “commonly”, and “typically” are not utilized herein to limit the scope of the claimed invention or to imply that certain features are critical, essential, or even important to the structure or function of the claimed invention. Rather, these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the present invention.
For the purposes of describing and defining the present invention it is noted that the term “substantially” is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term “substantially” is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
Having described the invention in detail and by reference to specific embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. More specifically, although some aspects of the present invention are identified herein as preferred or particularly advantageous, it is contemplated that the present invention is not necessarily limited to these preferred aspects of the invention. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority of the prior Japanese Priority Application No. 2013-004325 filed on Jan. 15, 2013, the entire contents of which are hereby incorporated by reference.
FIELD
The disclosures herein generally relate to a power consumption amount estimating apparatus and a power consumption amount estimating method.
BACKGROUND
A server has a mechanism for measuring power consumption or power consumption amount spent by itself. With such a measuring mechanism, power consumption (amount) may be measured for each resource such as a CPU (Central Processing Unit), a memory, a peripheral circuit, and the like. However, if multiple virtual machines (VMs) are running on a server, it is very difficult to measure power consumption of a resource for each of the virtual machines because the virtual machines share multiple resources.
There exists a technology that estimates power consumption of a virtual server by measuring CPU utilization and memory usage of an operation of the virtual server, converting them to CPU utilization and memory usage on a reference server that has a predetermined hardware configuration, and estimating power consumption on the reference server (see, for example, Patent Document 1).
There exists a technology that obtains power consumption of a virtual machine by providing a state mapping table in which power consumption of an operation corresponding to each operational state of a physical resource is specified, obtaining the number of operations actually executed by the virtual machine on the physical resource where the number is obtained by an operation counter in the physical resource, and multiplying an entry of the table by the number of operations to obtain power consumption (see, for example, Patent Document 2).
RELATED-ART DOCUMENTS
Patent Documents
[Patent Document 1] Japanese Laid-open Patent Publication No. 2010-039513
[Patent Document 2] Japanese Laid-open Patent Publication No. 2010-277509
SUMMARY
According to at least one embodiment of the present invention, a power consumption amount estimating apparatus for estimating a power consumption amount of a resource allocated to multiple virtual machines operating on a physical machine, the estimation being made for each of the virtual machines, includes: a power consumption amount measuring unit configured to measure the power consumption amount of the resource; a time identifying unit configured to identify a start time and an end time of a duration during which a processor is continuously allocated for one of the virtual machines; a power consumption amount obtaining unit configured to obtain the power consumption amount of the resource during the duration using the power consumption amounts at the start and end times; and a power consumption amount accumulating unit configured to accumulate multiple power consumption amounts of the resource for each of the virtual machines, the multiple power consumption amounts being obtained during multiple durations, respectively.
The object and advantages of the embodiment 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 DRAWINGS
FIG. 1 is a schematic view illustrating multiple virtual machines operating on a physical machine according to an embodiment;
FIG. 2 is a schematic view illustrating switching operations of multiple virtual machines according to an embodiment;
FIG. 3 is a schematic view illustrating memory allocation ratios of multiple virtual machines according to an embodiment;
FIG. 4 is a flowchart for measuring resource allocation of virtual machines according to an embodiment;
FIG. 5 is a flowchart for measuring power consumption according to an embodiment;
FIG. 6 is a schematic view illustrating an example of a summarized power consumption table;
FIG. 7 is a flowchart for measuring a steady part of power consumption according to an embodiment;
FIG. 8 is a schematic view illustrating an example of a steady power consumption table;
FIG. 9 is a schematic view illustrating a measurement example of power consumption and a power consumption amount of a device according to an embodiment;
FIG. 10 is a functional block diagram according to an embodiment;
FIG. 11 is another functional block diagram according to an embodiment; and
FIG. 12 is a schematic view illustrating a hardware configuration according to an embodiment.
DESCRIPTION OF EMBODIMENTS
To obtain a power consumption amount of a virtual machine, power consumption amounts of multiple resources used by the virtual machine may be accumulated, respectively. As a physical server may include various resources, it is desirable to measure or estimate power consumption amounts of the respective resources in suitable ways. If power consumption is measured (estimated) for resources used by a specific virtual machine, a power consumption amount of the specific virtual machine can be obtained by accumulating the power consumption amounts of the resources.
Also, by obtaining power consumption amounts of resources used by a virtual machine or a power consumption amount of the virtual machine itself, live migration of the virtual machine may be planned based on it. For example, there may be a case where a specific resource is intensively used by multiple virtual machines. In such a case, namely, if the power consumption amount of a specific resource of a physical machine steadily indicates a high value, a virtual machine to undergo live migration to another physical machine can be identified according to an embodiment of the present invention. By moving a virtual machine having high power consumption on a specific resource by live migration, the lifetime of the specific resource may be prevented from being shortened due to steady high-power consumption.
In the following, embodiments of the present invention will be described with reference to the drawings.
According to at least one embodiment of the present invention, it is possible to conveniently estimate a power consumption amount of a resource of a physical machine for multiple virtual machines operating on the physical machine.
Embodiments
FIG. 1 is a schematic view illustrating multiple virtual machines VM1-VM3 operating on a physical machine 100 according to the present embodiment. The physical machine 100 includes a CPU, a memory, I/Os, a disk, a network interface (NIC), and the like as hardware 102 . There exists server firmware 104 that operates on the hardware 102 . The server firmware 104 includes firmware for BIOS and for a virtual machine that constitutes an interface between a virtual machine monitor VMM and the hardware 102 . The virtual machine monitor VMM provides an operational environment for the virtual machines VM1-VM3. Here, the virtual machine monitor VMM is basic software for virtualization. The virtual machine monitor VMM emulates physical resources for each of the virtual machines VM1-VM3. Also, the VMM arbitrates requests from the virtual machines VM1-VM3, and isolates a memory space for each of the virtual machines VM1-VM3. Here, the embodiments of the present invention do not depend on a type of the virtual machine monitor VMM, which may be any one of a host-type, a hypervisor-type, a hybrid-type, or the like.
Also, although the embodiments of the present invention may be implemented on the virtual machine monitor VMM, implementation is not limited to that. Namely, it is obvious that a part or all of the embodiments of the present invention may be implemented on the server firmware 104 or the hardware 102 .
A guest OS 1 is installed on the virtual machine VM1, and applications 1 and 2 operate on the guest OS 1. A guest OS 2 is installed on the virtual machine VM2, and application 3 operates on the guest OS 2. A guest OS 3 is installed on the virtual machine VM3, and application N operates on the guest OS 1. These virtual machine VM1-VM3 can operate on the single physical machine 100 without interfering with each other under control of the virtual machine monitor VMM.
FIG. 2 is a schematic view illustrating switching operations of the virtual machines VM1-VM3 according to the present embodiment. The virtual machine monitor VMM operates from time t1 to t2 to save an operational environment before time t1 and to provide an operational environment for the virtual machine VM1 that has been scheduled to operate next. The virtual machine VM1 operates from time t2 to t3. Similarly, the virtual machine monitor VMM operates from time t3 to t4, the virtual machine VM2 operates from time t4 to t5, the virtual machine monitor VMM operates from time t5 to t6, and the virtual machine VM3 operates from time t6. Switching virtual machines in this way is one of the important roles of a virtual machine monitor.
FIG. 3 is a schematic view illustrating memory allocation ratios of the virtual machines VM1-VM3 according to the present embodiment. A memory 310 is illustrated that has capacity of L as a whole. The virtual machine monitor VMM allocates areas “a” and “d” to the virtual machine VM1, an area “c” to the virtual machine VM2, and an area “b” to the virtual machine VM3. Here, assume that “a” to “d” represent the sizes of areas, respectively. Therefore, as illustrated in a table 320 , usage ratios of the memory are (a+d)/L for the virtual machine VM1, c/L for the virtual machine VM2, and b/L for the virtual machine VM3. Memory allocation can be dynamically changed by the virtual machine monitor VMM if necessary. Therefore, if the virtual machine VM3 faces a shortage of memory, for example, the memory area can be expanded by allocating an unallocated area to the virtual machine VM3. Also, if it is determined that a part of the memory area for the virtual machine VM1 is not required any longer, for example, the memory area “a” may be released so that only the memory area “d” is allocated for the virtual machine VM1.
FIG. 4 is a flowchart for measuring resource allocation of virtual machines according to the present embodiment. The flowchart may be triggered by an interrupt. Here, Steps 402 and 422 are arranged in parallel. Only one of these steps may be executed. Alternatively, both steps may be executed. The steps may be executed in any order.
At Step 402 , a power consumption amount J(t) in time t for a resource is measured. Alternatively, power consumption W(t) may be measured instead. Here, time integral of a power consumption rate W(t) is the power consumption amount J(t), which may be obtained, for example, by connecting an integrator with a device measuring power consumption rate W(t). Here, such an integrator may be implemented by an analog circuit or a digital circuit. As the physical machine 100 has multiple resources, it is desirable to execute measurement for each of the resources. This will be described concretely using FIG. 9 . In addition, it is desirable to measure the measurement time of a power consumption amount J(t) (or power consumption rate W(t) if necessary). Measurement time may be set to predetermined intervals for a storage device such as a memory. In addition, it is desirable to measure power consumption amounts when virtual machines are switched. Measurement time may depend on characteristics of resources. Here, details will be described later when describing calculation of power consumption amounts for resources using FIG. 5 .
At Step 422 , usage ratios of the virtual machines VM1-VM3 are measured on a storage section. The usage ratios on the storage section dynamically change while the virtual machines VM1-VM3 operate. For example, if a virtual machine uses a larger physical memory space while another virtual machine uses a smaller physical memory space, it is desirable that a greater power consumption amount of memory is calculated for the virtual machine with the larger memory. Therefore, it is desirable to take dynamically changing memory usage ratios into consideration when calculating power consumption amounts of the virtual machines VM1-VM3 for a storage section such as a memory or a disk. For a resource other than a storage section such as a memory, but whose usage ratios by the virtual machines VM1-VM3 change similarly to the storage section above, usage ratios may be measured at Step 422 to calculate power consumption amounts. Here, instead of obtaining dynamically changing usage ratios of memory areas during operations of the virtual machines VM1-VM3, memory usage ratios may be measured only when a switching of virtual machine operations is started or ended. Alternatively, memory usage ratios may be measured when a switching of virtual machine operations is started and ended, and the average value of the start and end may be used. In this way, a periodic overhead for obtaining memory usage ratios can be reduced while the virtual machines VM1-VM3 operate. Alternatively, measurement of memory usage ratios of the virtual machines VM1-VM3 may be executed by special-purpose hardware, or implemented as a function of the firmware 104 . A concrete calculation method of power consumption amounts considering memory usage ratios will be described later using FIG. 5 .
FIG. 5 is a flowchart for measuring power consumption according to the present embodiment. In FIG. 5 , the flowchart illustrates just a part of operations of the virtual machine monitor VMM from time t3 to time t4 in FIG. 2 , which is for obtaining power consumption amounts. It is noted that the virtual machine monitor VMM executes processing steps other than the processing steps described here. The flowchart in FIG. 5 illustrates a flow for measuring (estimating) power consumption amounts for multiple resources, which includes steps that may not be required for a specific resource. In the following, content of processing will be described for each major resource.
In the following, measuring (estimating) methods of power consumption amount are described for major resources. It is noted that either of the methods may be applied to other resources depending on their characteristics. Also, by accumulating power consumption amounts obtained for the resources used by a specific virtual machine, the power consumption amount of the specific virtual machine can be obtained.
[Calculation Example of Power Consumption Amount of CPU]
It will be described using FIGS. 2, 4, and 5 . At time t3, the virtual machine VM1 ends its operation, and control is transferred to the virtual machine monitor VMM. The virtual machine monitor VMM starts a switching procedure between the virtual machines VM1 and VM2.
Next, a relationship between a virtual machine and a CPU will be described. If a CPU is allocated to the virtual machine VM1, the CPU is occupied by the virtual machine VM1 for a certain duration (from time t2 to time t3) to operate only for the virtual machine VM1. The CPU controls the virtual machine VM1 and the other resources. Namely, all of the power consumption amount of the CPU while it is occupied with the virtual machine VM1 may be accumulated to the power consumption amount of CPU for the virtual machine VM1. There are resources other than a CPU that are occupied by a virtual machine in this way. For example, an input/output controller, a bus, or a network controller, and the like are this kind of resources. Although the following description is for a power consumption amount of a CPU, it is noted that power consumption amounts of the same kind of resources can be calculated by substantially the same procedures, respectively.
At Step 502 , a power consumption amount of a CPU and time are measured as illustrated in FIG. 4 . The power consumption amount of CPU and time may be stored into a memory when measured. Measurement may be executed at Step 502 . Also, the time to be stored may be execution time of Step 502 .
Also, at Step 529 , which is the step just before the end of the virtual machine switching operation at time t4, a power consumption amount of CPU and time may be measured as illustrated in FIG. 4 . The measured amount and time may be stored into the memory for later usage.
Although FIG. 5 is illustrated for time t3 to t4 as mentioned above, it is noted that substantially the same processing flow as in FIG. 5 can be executed by the virtual machine monitor VMM at other timings, for example, for time t1 to t2 and time t5 to t6.
At Step 510 , a power consumption amount of CPU is calculated for the virtual machine VM1 from time t2 to t3. The power consumption amount of CPU from time t2 to t3, Jcpu(t2, t3), can be calculated by the following formula.
J cpu( t 2 ,t 3)= J cpu( t 3)− J cpu( t 2) (1)
Here, Jcpu(t3) is a power consumption amount of CPU at time t3, which has been obtained at Step 502 in FIG. 5 . Jcpu(t2) is a power consumption amount of CPU at time t2, which has been obtained and stored at Step 529 executed just before time t2. The power consumption amount of CPU Jcpu(t2, t3) calculated here is accumulated to a previously accumulated power consumption amount of CPU (an entry C1 in a VM power consumption amount table 600 in FIG. 6 ), and stored into the same location (entry C1) (Step 510 ).
For other resources, for example, an input/output controller, a bus, a network controller, and the like, power consumption amounts can be calculated for the virtual machine VM1 from time t2 to t3 by substantially the same procedures as for a CPU.
[Calculation Example of Power Consumption Amount of Memory]
As illustrated with the memory 310 in FIG. 3 , certain areas in a storage section such as a memory are occupied by the virtual machines VM1-VM3, respectively. For example, assume that a physical machine is in an idle state. Even in this case, the memory consumes power at least for refreshing. It is desirable to distribute such power consumption to the virtual machines VM1-VM3 depending on the usage ratios 320 of the memory as illustrated in FIG. 3 . Therefore, based on this idea, it is desirable to obtain a power consumption amount of memory while a physical machine is idle (called a “steady part of power consumption”, hereafter) in advance, to distribute the power consumption amount depending on changes in memory allocation. Here, it is desirable to distribute increased parts of power consumption amounts generated by memory access to the respective virtual machines VM1-VM3. Therefore, a power consumption amount of memory Jmem(t2, t3) from time t2 to t3 can be calculated, for example, as follows.
Jmem
(
t
2
,
t
3
)
=
∫
t
=
t
2
t
3
α
(
t
)
×
Wc
+
∫
t
=
t
2
t
3
(
W
(
t
)
-
Wc
)
(
2
)
Here, α(t) represents memory usage ratio of the virtual machine VM1 as a function of time, and Wc represents a power consumption amount of memory while a physical machine is idle. Also, W(t) represents a power consumption rate of memory while a physical machine is operating as a function of time. Therefore, the left integral term represents a steady part of power consumption amount of memory of the virtual machine VM1 taking its memory usage ratio into consideration (Step 512 ). The right integral term represents a variable part of power consumption amount of memory of the virtual machine VM1 (Step 514 ). Here, if adopting this calculation formula (2), it is necessary to obtain and store the memory usage ratio α(t) and the power consumption rate of memory W(t) during an operation of the virtual machine VM1. Here, instead of obtaining these parameters, an overall power consumption amount of memory Jm(t) may be measured, and the average value of memory usage ratios at time t2 and t3 may be used for memory usage ratios. For example, the following formula may be used.
Jmem
(
t
2
,
t
3
)
=
α
(
t
2
)
+
α
(
t
3
)
2
×
Wc
×
(
t
3
-
t
2
)
+
(
Jm
(
t
3
)
-
Jm
(
t
2
)
-
Wc
×
(
t
3
-
t
2
)
)
(
3
)
Here, as for memory usage ratios, the average value of memory usage ratios α(t2) and α(t3) is used in the above formula. Alternatively, only α(t2) or α(t3) may be used instead.
The power consumption amount of memory calculated here is accumulated to a previously accumulated power consumption amount of memory (an entry M1 in the VM power consumption amount table 600 in FIG. 6 ), and stored into the same location (Step 510 ).
Here, if an input/output controller is partially allocated to virtual machines, a usage ratio of the input/output controller allocated to a specific virtual machine may be identified based on a ratio of the part of the input/output controller to the whole, and a power consumption amount of the specific input/output controller may be calculated by substantially the same calculation method as for a memory. For other resources, the above calculation method of a power consumption amount of memory may be adopted depending on characteristics of the resources.
The present invention is not limited to the above formula.
[Power Consumption Amount of VMM Itself]
As a power consumption amount other than power consumption amounts of the virtual machines VM1-VM3, a power consumption amount of the virtual machine monitor VMM itself exists. For the flow in FIG. 5 from time t3 to t4, data from time t1 to t2 has been stored to be utilized. Therefore, a power consumption amount Jvmm(t1, t2) of the virtual machine monitor VMM from time t1 to t2 has been calculated at Step 522 in FIG. 5 . Jvmm(t1, t2) may be calculated using the following formula (4), for example, if the power consumption rate WT(t) of the physical machine at time t has been measured.
Jvmm
(
t
1
,
t
2
)
=
∫
t
=
t
2
t
3
WT
(
t
)
(
4
)
Alternatively, if the power consumption amount JT(t) of the physical machine at time t has been measured, it may be calculated as follows.
Jvmm ( t 1 ,t 2)= JT ( t 2)− JT ( t 1) (5)
Jvmm(t1, t2) obtained in this way is accumulated to a value in an entry v1( 610 ) for power consumption amount of the virtual machine monitor in FIG. 6 , and written back to the same entry v1.
Also, a power consumption amount may be calculated for time when none of multiple virtual machines are allocated with a CPU.
Here, the present invention is not limited to the above formulas.
[Calculation Example of Power Consumption Amount of Power Source Unit]
For example, a power source unit (PSU) or a fan is a resource whose power consumption amount fluctuates depending on a power consumption amount of a specific virtual machine, and shared by multiple resources. Therefore, for example, the following method may be used for calculating a part of power consumption amount of the power source unit used by each of the virtual machines VM1-VM3. For example, power consumption amounts of resources ( FIG. 6, 602 ) occupied by the respective virtual machines VM1-VM3 are added for the respective virtual machines VM1-VM3 to calculate subtotals of power consumption amounts Y1, Y2, and Y3 for the respective virtual machines VM1, VM2, and VM3 ( 612 ). Using the subtotals, a power consumption amount Jpsu(t) of the power source unit (PSU) at time t may be distributed to the virtual machines VM1-VM3 proportionately. A concrete formula may be as follows.
P
1
=
Y
1
Y
1
+
Y
2
+
Y
3
+
v
1
×
Jpsu
(
t
)
(
6
)
P
2
=
Y
2
Y
1
+
Y
2
+
Y
3
+
v
1
×
Jpsu
(
t
)
(
7
)
P
3
=
Y
3
Y
1
+
Y
2
+
Y
3
+
v
1
×
Jpsu
(
t
)
(
8
)
where v1 represents a power consumption amount of the virtual machine monitor VMM itself for managing the virtual machines VM1-VM3. As illustrated in FIG. 6 with entries 604 , P1, P2, and P3 represent values distributed to the virtual machines VM1, VM2, and VM3 as parts of a power consumption amount of the power source unit PSU, respectively.
Similarly as above, power consumption amounts of a cooling fan or the like can be calculated for the respective virtual machines.
As illustrated in the VM power consumption amount table 600 in FIG. 6 power consumption amounts of resources for each of the virtual machines VM1, VM2, and VM3 are stored, with which total power consumption amounts X1, X2, and X3 ( 614 ) are calculated for the respective virtual machines VM1-VM3.
FIG. 7 is a flowchart for measuring a steady part of power consumption amounts according to the present embodiment. For example, a steady part of power consumption amounts of a memory is calculated as follows. Here, for a resource other than a memory, such as a hard disk, it is calculated in a similar way. It is desirable to execute this procedure while a physical machine is idle.
At Step 702 , a power consumption amount of memory 1 is obtained.
At Step 704 , the obtained power consumption amount 1 is stored into a resource power consumption table 810 in FIG. 8 .
At Step 706 , wait for, for example, 10 s.
At Step 708 , a power consumption amount of memory 2 is obtained.
At Step 710 , the difference of the power consumption (power consumption amount 2−power consumption amount 1) is calculated.
At Step 712 , a deviation is calculated with a power consumption amount calculated in the previous loop and a power consumption amount calculated in the current loop.
At Step 714 , the deviation and a default value are compared. If the deviation is less than the default value (YES), the procedure goes to Step 716 . If the deviation is greater than or equal to the default value (NO), the procedure goes back to Step 704 .
If going back to Step 704 , the previous power consumption amount of memory 2 is stored into the resource power consumption table 810 , and the loop is repeated.
At Step 716 , the power consumption amount value is stored into a steady power consumption table 820 in FIG. 8 because the measured power value is determined to indicate a steady value at Step 714 , and the procedure ends.
The above procedure is executed for resources other than a memory.
FIG. 8 is a schematic view illustrating an example of tables related to steady power consumption amounts of resources. In FIG. 8 , the resource power consumption table 810 stores measured results of power consumption (power consumption amount for 10 s) for the resources.
The steady power consumption table 820 in FIG. 8 stores steady values of power consumption rates of the resources obtained by the procedure in FIG. 7 . P-idle-mem represents steady power consumption rate W1 of memory. P-idle-io represents steady power consumption rate W2 of an input/output interface. P-idle-disk represents steady power consumption rate W3 of a disk.
FIG. 9 is a schematic view illustrating a measurement example of power consumption rate and a power consumption amount of a device M according to the present embodiment. The device M as a resource is supplied power at terminals P and Q. An amperemeter 910 and a voltmeter 920 are disposed on a power supplying path. Representing a current value by A and a voltage value by V at time t, power consumption rate W(t) at time t is calculated by the following formula with a power consumption calculator 930 .
W ( t )= A×V
In addition, by integrating the power consumption rate with a power consumption amount calculator 940 , a power consumption amount J(t) of the device M is calculated as follows.
J
(
t
)
=
∫
t
1
=
0
t
W
(
t
1
)
(
9
)
The power consumption calculator 930 and the power consumption amount calculator 940 may be implemented by an analog circuit or a digital circuit. By disposing such power measuring circuits for resources, it is possible to obtain power consumption amounts of the resources as functions of time, respectively.
FIG. 10 illustrates an example of a functional block diagram 1000 that implements the process described, for example, in [Calculation example of power consumption amount of CPU] or [Power consumption amount of VMM itself].
A control unit 1006 has a function for allocating a predetermined resource 1002 to a specific virtual machine, and identifies the time when the resource is allocated.
A power consumption amount measuring unit 1008 measures power consumption amounts of the resource.
A power consumption amount obtaining unit 1010 obtains and outputs a power consumption amount of the resource at the identified time. For example, it obtains power consumption amounts of a CPU at a start time and an end time of a duration during which a CPU is continuously allocated to the virtual machine VM1. The obtained power consumption amount of the CPU for the duration is added to the entry C1 for VM1 in the VM power consumption amount table in FIG. 6 . Here, a resource 1002 may be a CPU, an input/output controller, a bus, a network controller, or any other one of the resources that consume power and shared by the virtual machines VM1-VM3. Procedures for the resources are the same as described above for a CPU, and description is omitted.
A power consumption amount of the virtual machine monitor VMM itself may be obtained, for example, by identifying a start time and an end time of a duration during which a CPU is continuously allocated to the virtual machine monitor VMM (i.e., no virtual machines are allocated with the CPU) based on time information from the time identifying unit 1004 , and accumulating power consumption amounts of multiple resources for the duration (power consumption amount of the physical machine itself) that are to be shared by the virtual machines VM1-VM3. By adding the obtained power consumption amount to the value of v1 in the storage area 610 in FIG. 6 , an accumulated value of the power consumption amount of the virtual machine monitor VMM is stored into v1.
FIG. 11 illustrates an example of a functional block diagram 1100 that implements the process described, for example, in [Calculation example of power consumption amount of memory] or [Calculation example of power consumption amount of power source unit]. Here, the same blocks as in FIG. 10 are designated with the same numerical codes, and their description is omitted.
A usage ratio obtaining unit 1102 obtains memory usage ratios of the virtual machines VM1-VM3 that occupy certain memory areas. Usage ratios may be obtained for resources other than a memory, for example, a hard disk, a silicon disk, or any other of various storage devices. Alternatively, if a part of input/output ports of an input/output controller is occupied by one of the virtual machines VM1-VM3, usage ratios of the virtual machines VM1-VM3 on an input/output controller may be obtained. In this case, the input/output controller may have the same process applied as a memory to obtain power consumption amounts of the respective virtual machines VM1-VM3. Therefore, it is noted that the process described for a memory is applicable to the other resources in the present specification. This is the same for the following description.
A steady power consumption amount identifying unit 1106 executes the procedure described in FIG. 7 . Namely, if a physical machine is in an idle state, it obtains a steady part of power consumption amount of the resources, and stores the part into the memory (for example, the steady power consumption table 820 in FIG. 8 ).
A steady power consumption amount obtaining unit 1112 may calculate the following term in formula (3) described above.
α
(
t
2
)
+
α
(
t
3
)
2
×
Wc
×
(
t
3
-
t
2
)
Alternatively, it may calculate the left integral term in formula (2).
A variable power consumption amount obtaining unit 1114 may calculate the following term in formula (3) described above.
( Jm ( t 3)− Jm ( t 2)− Wc ×( t 3 −t 2))
Alternatively, it may calculate the right integral term in formula (2). Here, the present invention is not limited to these formulas.
An adder 1116 adds values output from the steady power consumption amount obtaining unit 1112 and the variable power consumption amount obtaining unit 1114 , and outputs the added result to a power consumption amount accumulating unit 1020 .
A proportional distribution unit 1118 may use the VM power consumption amount table 600 in FIG. 6 generated by the power consumption amount accumulating unit 1020 . Specifically, using the subtotals 612 calculated in the VM power consumption amount table 600 , it distributes power consumption amounts of the cooling fan, the power source unit (PSU) and the like to the virtual machines VM1-VM3. Proportionate distribution may be executed with, for example, the above formulas (6)-(8).
Here, the power consumption amount accumulating unit 1020 may calculate total power consumption amounts X1, X2, and X3 for the virtual machines VM1, VM2, and VM3, respectively, in the VM power consumption amount table 600 in FIG. 6 .
Here, the present invention is not limited to the resources illustrated as examples in the VM power consumption amount table in FIG. 6 . For example, for a resource dedicated for a specific virtual machine, a power consumption amount of the resource may be counted only for the specific virtual machine. Also, a resource connected by serial transfer or the like may operate at a timing later than an operation of the corresponding virtual machine. In this case, by identifying a virtual machine that makes the operation request to the resource, the power consumption amount of the resource may be associated with the virtual machine. In other words, it is noted that care should be taken as described above if there is a difference between a time interval for allocating a CPU to a specific virtual machine and a time interval used for counting the power consumption amount of a resource used by the specific virtual machine.
FIG. 12 is a schematic view illustrating a hardware (computer) configuration according to the present embodiment. The hardware may include a CPU 1202 , a BIOS firmware 1204 , a RAM 1206 , an input/output controller 1208 , a disk 1210 , a drive unit 1212 , and a network interface card (NIC) 1214 . These devices may be connected with each other by a bus 1208 . Also, the drive unit 1212 can read from or write to a storage medium 1216 . The NIC 1214 may be connected with a network (not illustrated here).
Here, all or a part of the present embodiment may be implemented by a program. The program may be stored into the storage medium 1216 , the disk 1210 , the RAM 1206 , or the like. The storage medium 1216 is one or more non-transitory storage media having a structure. For example, the storage medium 1216 may be a magnetic storage medium, an optical disk, an optical-magnetic storage medium, a non-volatile memory, or the like. A magnetic storage medium may be an HDD, a flexible disk (FD), a magnetic tape (MT), or the like. An optical disk may be a DVD (Digital Versatile Disc), a DVD-RAM, a CD-ROM (Compact Disc-Read Only Memory), a CD-R (Recordable)/RW (ReWritable), or the like. Also, an optical-magnetic storage medium may be an MO (Magneto-Optical disk), or the like. By loading the program stored in the storage medium 1216 to have a CPU execute the program, all or a part of the present embodiment may be executed.
In a data center, virtual machines for multiple corporations may operate on a physical machine owned by the data center. In this case, the data center needs to charge the corporations for usage of virtual machines. If power consumption amounts of the virtual machines VM1-VM3 are obtained, they may be used as one of the factors for calculating charges for usage of the virtual machines VM1-VM3 for the respective corporations.
Also, corporations may need to disclose amounts of carbon dioxide emissions for accomplishing their corporate social responsibility. In general, this is called a “carbon footprint disclosure”. From this viewpoint, a corporation may need to obtain a power consumption amount of a virtual machine that operates for the corporation if the corporation operates the virtual machine on a physical machine owned by another corporation. This is because the corporation needs to count the amount of carbon dioxide emissions corresponding to operations of the virtual machine used for the corporation as its own emissions.
Therefore, it becomes increasingly important to grasp power consumption amounts of virtual machines (and/or power consumption amounts of resources for respective virtual machines).
All examples and conditional language recited herein are intended for pedagogical purposes to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art, and are to be construed as being without limitation to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention. | 4y
|
BACKGROUND OF THE INVENTION
Pneumatic power tools have been used extensively in industrial and construction applications for well over the last century. These tools frequently are pneumatic grinders, drills and wrenches in industrial applications and paving breakers, earth borers and chipping hammers in the construction industry.
All these tools, however, have the same basic configuration, including a reciprocating piston or rotary air motor for driving or impacting an associated tool and a handle portion with an operator-controlled trigger and valve assembly that connects compressed air from a fitting to the motor. Fluid passageways are conventionally formed in the handle portion and in a tool body portion that is adjacent to the motor for conveying air under pressure to the motor.
The formation of the air passages in the handle portion and in the tool body has always been a problem because it is not economically practical to core these passageways during the forging operations for the handle and the tool body, particularly where these fluid passageways must be curved to accommodate the configuration of the tool. For these reasons, the fluid passageways in the handle portion and the tool body are today formed largely by drilling operations subsequent to the forging of the parts. Where the passageways must curve or turn, it is necessary to drill multiple angularly related intersecting bores in the tool and then cap the exterior openings of the bores with a weldment to seal the passageway. This multiple drilling technique requires different machine setups because of their angular relationship and has been found to be a very significant cost factor in the overall tool cost.
It is a primary object of the present invention to ameliorate the problems noted above in forming fluid passageways in pneumatic power tools.
SUMMARY OF THE PRESENT INVENTION
In accordance with the present invention, a pneumatic power tool and method of manufacture are provided in which most of the fluid passageways in the tool handle portion and tool body are formed by casing external grooves in the parts, covering the grooves with high temperature resistant tape and then molding a highly elastic thermosetting elastomeric material around the parts covering the tape and grooves to form the fluid passageways. In addition to forming the passageways, the elastomeric coating provides an insulated, comfortable, non-slip hand grip for the operator.
This method of manufacture eliminates the requirement for drilling even straight passageways but more importantly eliminates the requirement for drilling multiple intersecting passageways and welding the passageways closed at their external openings to form angular or generally curved passageways.
While the present invention has utility in a variety of fluid operated power tools, it is specifically represented in the present specification as a chipping hammer, which is a relatively small hand-held pneumatic tool that reciprocates a blade-type tool used to break away hard particulate surfaces such as vertical cementatious ones. These tools conventionally include an arcuate handle having a trigger-operated on/off valve adjacent a compressed air inlet at the end of the handle. The handle is connected to a straight barrel portion that reciprocably receives a piston which impacts the end of a blade-type chipping tool.
Fluid passageways are formed in both the handle and the barrel by substantially the same technique according to the present invention. In the handle, which like the barrel is a steel casting, a groove is formed in the casting operation in the exterior of the part from the trigger valve to the portion of the handle into which the barrel is threaded. This is far simpler than coring an internal passage. After casting, this groove is covered by a high temperature fiberglass tape that has a contact adhesive on one side thereof. The handle with the taped groove is then placed into a mold as an insert and a polyurethane elastomer is cast completely around most of the handle covering the tape and the groove. The polyurethane is a high tear strength, high elongation resin with a shore A durometer of 75 to 85. The polyurethane is cured or polymerized in the mold in a curing oven at approximately 300 degrees F. for 11 minutes. The resulting urethane coating on the handle is approximately 0.250 inches in thickness, sufficiently thick to withstand the 90 to 100 psi air pressure normally encountered in pneumatic tools of this type.
Air delivery and exhaust passages are similarly cast in the tool barrel, covered with tape and then encapsulated with a polyurethane molding.
Other objects and advantages will appear more clearly in the following detailed description of the present chipping hammer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal section of the chipping hammer according to the present invention;
FIG. 2 is an enlarged sub-assembly view in longitudinal section of the handle member of the chipping hammer illustrated in FIG. 1 in its as cast condition;
FIG. 3 is a cross-section taken generally along line 3--3 of FIG. 2 illustrating the fluid passage in the handle covered by high temperature tape;
FIG. 4 is a cross-section of the chipping hammer illustrating part of the fluid passage therein covered by high temperature tape taken generally along line 4--4 of FIG. 2;
FIG. 5 is a longitudinal section of the handle assembly coated with polyurethane;
FIG. 6 is a cross-section of the tool handle after the addition of the polyurethane molding taken generally along line 6--6 of FIG. 5;
FIG. 7 is a longitudinal section of the tool barrel prior to polyurethane encapsulation illustrating one of the piston return passageways;
FIG. 8 is a cross-section of the tool barrel taken generally along line 8--8 of FIG. 7;
FIG. 9 is a longitudinal section of the tool barrel similar to FIG. 7 after polyurethane encapsulation;
FIG. 10 is a longitudinal section of the cylinder barrel taken through the exhaust passageways after encapsulation with polyurethane; and,
FIG. 11 is a cross-section of the encapsulated cylinder barrel taken generally along line 11--11 of FIG. 10.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings, and particularly FIG. 1, a chipping hammer 10 is illustrated according to the present invention generally including a handle assembly 12 having an air inlet swivel 13, a barrel assembly 15, defining a motor with reciprocating piston 16, and a reciprocably mounted bladed point or "steel" 17 adapted to be impacted by piston 16 as it reciprocates in the barrel assembly 15.
While the present invention is shown incorporated into chipping hammer 10, it should be understood that the principles of forming fluid passageways according to the present invention are applicable to other fluid-operated power tools as well, particularly those that require curved or turning fluid passageways.
The handle assembly 12 includes an arcuate portion 18 having a generally circular cross-section that is a one-piece steel casting. Handle portion 18 has an inlet fitting 20 threaded into its free end that rotatably receives the air inlet swivel 13 adapted to be connected to a source of compressed air such as a motor driven compressor. A central stepped bore 22 is provided in handle 18 that includes an upper reduced diameter portion 23, a somewhat enlarged central portion 24, a reduced pilot portion 25 and an enlarged chamber portion 26. A valve assembly 27 is reciprocably mounted in stepped bore 22 and includes a valve head 29 carried on an enlarged land 31, a small guide land 33 slidable in bore portion 25, a second guide land 35 slidable in bore 33, and a stem portion 37 engageable and depressable by a pivotal trigger 38. The valve assembly 27 is biased to its closed position where valve head 29 engages seat 39 in handle 18, by a coil compression spring 41 that reacts against the lower side of valve 29. Upon depression of trigger 38 by the operator's hand, valve assembly 27 will move to its open position porting fluid from the inlet swivel 13 across open valve seat 39 into chamber 24 and through arcuate handle passageway 44 to the barrel assembly 15. Upon release of trigger 38, the valve assembly closes. The handle casting 18 is covered by a polyurethane thermosetting coating 46 that is applied by the method described more clearly hereinbelow.
The barrel assembly 15 is seen to include an elongated straight cylindrical steel casting 47 covered by a polyurethane coating 48 similar to coating 46 around handle portion 18. Barrel casting 47 has a threaded inner end 49 threadedly received in a threaded bore 50 in a forwardly extending end 52 of handle portion 18. Barrel casting 47 is locked to the handle portion 18 by a lock nut 54 and an annular metal deflector 56 spans an exhaust space 58 between lock jam nut 54 and polyurethane coating 48, and it has an unshown slot that forms an exhaust passage from the chipping hammer 10. The operator may rotatably adjust the deflector 56 so that it exhausts air away from his or her body.
The barrel assembly 15 generally includes a valve cap 60, a ring valve 61 that selectively ports fluid under pressure to both sides of the piston 16, a cylinder bore 62 slidably receiving piston 16, and a bushing 64 carrying a seal 65 that slidably receives shank 66 on tool 17.
The valve cap 60 is circular in configuration and is pinned to the barrel 47 by a pair of diametral pins 67 and is axially locked against shoulder 69 in the end of handle portion bore 50.
The cap 60 serves to axially locate the ring valve 61 which is annular in configuration having circular inner and outer surfaces.
The barrel member 47, as seen in FIGS. 1, 7 and 9, has a radial forward port 71 and a diametrally opposed radial return port 72 that are controlled by the radial movement of ring valve 61 to port fluid to opposite sides of the piston 16. Port 71 communicates with the rear side of piston 16 in cylinder 62 while port 72 communicates with the forward side of piston 16 through two closely spaced axial passages 74, two adjacent communicating scalloped grooves 75 in the periphery of the barrel member 47, and radial ports 78 and 79.
The barrel casting 47 has exhaust passageways communicating with chamber 58 including a pair of diametrally opposed central ports 81 and 82 that communicate with axially arcuate grooves 83 and 84 that in turn communicate with exhaust chamber 58. Similarly, diametrally opposed ports 85 and 86 communicate with exhaust through grooves 83 and 84.
The valve 61 effects alternate pressurization of ports 71 and 72 by slight vertical movement in the plane of FIG. 1. This vertical movement is possible because the reduced diameter surface 87 on the end of the barrel 47 on which the ring 61 is seated has eccentrically disposed upper and lower semi-cylindrical surfaces with the same length radius formed on centers on the vertical axis of barrel 47 spaced 0.022 inches from one another with the radii overlapping. The radius of these two upper and lower surfaces is equal to the inner diameter radius of ring valve 61 so it seats and seals against both surfaces although not at the same time. The resulting vertical diameter of surface 87 is 0.022 inches less than the inner diameter of valve ring 61 enabling ring 61 to shift upwardly to close port 71 and open port 72 and to shift downwardly to close port 72 and open port 71 depending upon the differential pressure acting on ring valve 61.
Assuming ring valve 61 to be in its lower position opening port 71, fluid pressure is applied to the right side of the piston and with the piston in its rearmost position, air pressure applied to the right side of piston 16 drives it forwardly in the cylinder 62. As rear end 88 of the piston uncovers ports 85, 86, the right end of cylinder 62 will be exhausted through ports 85, 86, and the piston 16 then proceeds forwardly under its own inertia. At about the same time piston 16 covers exhaust ports 81, 82, so that the forward end of the cylinder 62 is blocked from exhaust causing a pressure rise on the forward side of piston 16, which is transmitted through return passages 78, 79, 75 and 74 to port 72 causing ring valve 61 to shift upwardly in the plane of FIG. 1 opening port 72 to inlet fluid pressure in passage 44, and closing lower port 71. This causes inlet fluid pressure to be applied to the forward end of piston 16 reversing movement of the piston after impacting steel 17 with fluid in the right side of piston 16 exhausting through ports 85, 86, across deflector 56. After piston 16 closes exhaust ports 85, 86, and at about the same time opens exhaust ports 81, 82, pressure increases on the rear side of piston 16 and drops on the forward side thereof causing a pressure increase at port 71 and a pressure decrease at port 72 resulting in ring valve 61 shifting downwardly in the plane of FIG. 1, reversing movement of the piston prior to impacting cap 60.
According to the present invention the passageway 44 in the handle assembly 12 and the passageways 75, 83 and 84 in the barrel assembly 15 are formed by a unique method that eliminates the requirement for complex drilling and welding.
As seen in FIG. 2, the arcuate handle portion or member 18 is a steel casting that is formed as cast with an arcuate groove on its inner periphery that has an enlarged portion 90 as seen in FIGS. 3, 4 and 6. After casting the handle portion 18, the entire exterior surface of the handle 18 is carefully cleaned and dried and a high temperature fiberglass tape 92 is applied over the groove 44 along its entire length as seen in FIG. 5, including the length of the enlarged portion 90. Tape 92 is a high temperature tape capable of withstanding at least 320 degrees F., and it carries an acrylic contact adhesive on one side thereof. One such tape that has been found suitable for this purpose is Temp. R. Tape No. G569 manufactured by CHR Industries of New Haven, Conn.
After the application of the high temperature tape 92 to the handle 18, the handle 18 is placed in a mold as an insert with the mold having a cavity configuration complementary to the periphery of the total assembly as shown in FIG. 5. A highly elastomeric polyurethane resin is thoroughly mixed with an appropriate moca catalyst, evacuated to remove air entrapments, and poured into the mold around the casting 18 forming a coating of approximately 0.250 inches around the periphery of the casting 18 except for trigger slot 94, which remains uncovered. Tape 92 serves to preserve the integrity of the passage 44 and the enlarged grooved portion 90 as seen in FIGS. 3, 4 and 5, during the molding operation.
The mold with the handle 18 as an insert is then placed in an oven at approximately 300 degrees F. for about 12 minutes polymerizing and curing the polyurethane mixture. Several polyurethanes, such as the high elongation thermosetting polyurethanes manufactured by Uniroyal Chemical Company, under the trademarks Vibrathane or Adiprene L-42, can be used for this purpose so long as the resulting coating has a shore A durometer in the range of 75 to 85 with high tear strength and high elongation (in the range of 700 to 850) characteristics to withstand the pulsing of high pressure 90 to 100 psi air in the tool passageways.
Portions of the passageways in the barrel assembly 15 are formed in a similar manner to the passageway 44 in the handle assembly 12. Viewing FIGS. 7, 8 and 11, adjacent grooves 75, 83 and 84 are cast into the barrel 47, which is a steel casting and then the same high temperature tape 96, 97 and 98 is applied to grooves 75, 83 and 84. Thereafter, barrel 47 is placed into a mold as an insert having a cavity configuration complementary to the outer periphery of the assembly shown in FIGS. 9 and 10, and the same polyurethane mixture is poured into the mold, and the mold heated to cure the polyurethane coating illustrated in FIGS. 1, 9 and 10 in exactly the same manner as the coating 46 around the handle 18.
After curing, the tape portions 100 and 101 of tapes 97 and 98 are removed opening passages 83 and 84 to the periphery of the barrel assembly. This technique enables cross passages to be easily formed.
In the above manner, the majority of the passageways normally formed in the tool handle and the barrel are cast, rather than drilled, in the steel parts and covered, enclosed and sealed in an efficient and highly reliable way with a heavy thermosetting polyurethane coating. | 4y
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BACKGROUND OF THE INVENTION
This invention relates to an operating mechanism for vehicles with an automatic transmission, wherein the mechanism hinders the movement of the shift lever from the park position if certain conditions are not fulfilled.
Such mechanisms are already known. Accordingly, from DE-A-3 617 256, it is known to use an operating mechanism with a blocking device which in certain positions blocks said mechanism, thereby hindering the movement of the shift lever if certain conditions are not fulfilled. This known operating mechanism either locks in a park position (P) or in a neutral position (N). The condition which has to be fulfilled in order to unlock the shift lever, in either of these two positions, is that the brake pedal must be activated. An activation of the brake pedal causes a solenoid-actuated locking pin to be moved out of its locking position whereby the shift lever can be moved freely. The disadvantage with this known mechanism is that the blocking device directly locks the shift lever and that no further activation of, for example, a button is necessary in order to unlock the shift lever in connection with activation of the brake pedal. As a consequence, when checking if the shift lever is locked or not, the force is directly transmitted via the shift lever to the locking mechanism if in the locking positions. As the shift lever has a considerable length this will result in an undesired lever effect, which implies that the locking mechanism will be subjected to large forces. This locking mechanism and the shift lever therefore have to be dimensioned with respect to relatively large forces.
A known solution do the above-mentioned problem is shown in EP-A-300 268. This operating mechanism shows a blocking device which, when being moved from said locking position, requires activation of a button at the same time that the conditions of activating the brake pedal and switching on the ignition are fulfilled. When these latter conditions are fulfilled it is possible by activation of the button to move a locking pin which is mounted adjacent to the shift lever, down into the groove of a cage which is rotatably arranged on the shift lever. The rotation of said cage is performed, at least in one direction, by means of a solenoid whose position is controlled in response to whether the brake pedal is activated. This known device, however, has several disadvantages. Amongst others, all embodiments show a cage-like blocking device which is rotatably arranged on the outside of the shift lever. This design leads to relatively large surfaces between the blocking device and the shift lever being in contact, between which surfaces movement takes place. Accordingly, this can result in a relatively large frictional resistance and the design may be rather susceptible to influence of external particles which are friction-increasing. Therefore there is a risk that such a design would not work if such a negative influence occurred which would increase the frictional resistance to a level exceeding a certain predetermined force. The risk of such a malfunction is considered to be related to the size of said surface, partly because the frictional force is directly proportional to the relation of the contacting surfaces between two elements and partly because it can be assumed that the difficulty in keeping a component protected from the influence of external particles is, to a certain extent, related to the size of the surface.
A further disadvantage is that the known device has extra means, either in the form of spring or linkage devices, between the solenoid and the blocking device.
Moreover, this known device shows a blocking device which is rotated about an axis situated solely in the vertical plane. This implies that the known solution will not be able to make use of the gravitational force for moving/rotating the locking device.
From EP-A-324 469 there is known a further operating mechanism of a similar kind. This mechanism, however, has the major disadvantage that an intermediate device is pivotally mounted between the solenoid and the blocking device, which of course increases the complexity. A further disadvantage is that the blocking device is interconnected with the shift lever in such a manner that it moves together therewith.
OBJECT AND SUMMARY OF THE INVENTION
It is a first object of this invention to provide an operating mechanism, wherein the force is not directly transmitted via the shift lever to the locking mechanism, if in the locking position, when checking whether the shift lever is locked or not.
Another object is to create such a mechanism which is relatively unsusceptible to the influence of external particles and wherein the number of components is relatively low. It is of course desired to reduce the number of components for several reasons, e.g. cost and reliability.
Furthermore, the invention has as its object to achieve an operating mechanism with a locking device wherein the details have such a configuration that they can be produced in a rational manner.
Yet a further object of the invention is to create an operating mechanism of the above-mentioned kind which, if the power is cut off, after certain measures, enables said locking device to be released so that the shift lever, despite the power-cut, can be moved out of the park position.
Other objects will be apparent as the description progresses.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following the invention will be described in more detail, by way of example only, with reference to the drawings in which;
FIG. 1 is a side cross-sectional view showing a principal arrangement of an operating mechanism which is suited for being provided with the present invention,
FIG. 2 shows the above mechanism seen from the front,
FIG. 3 is a side-view of chosen parts of the preferred embodiment of the invention,
FIG. 4 is an enlarged partial side view which shows the locking device in a first position,
FIG. 5 is a view which shows the locking device in a second position,
FIG. 6 shows a preferred embodiment of a locking device in accordance with the invention,
FIGS. 7,8 show a preferred embodiment of a releasing mechanism in accordance with the invention,
FIG. 9 shows a preferred embodiment of the locking device in its first position, and
FIG. 10 is a view which shows the second position of the preferred locking device of FIG. 9.
DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 shows a shift lever 1 which is pivotally mounted about a shaft 3. On the opposite side of said shaft 3 are levers 4,14 which are interconnected with the transmission box. At the top of the shift lever 1 is a knob 2. On the knob 2 there is a button 7 which at least in a certain predetermined position of the shift lever has to be activated in order to permit movement of the shift lever out of said predetermined position.
The button 7 is connected to a rod 8 which extends within the tubular shift lever 1. At the lower end of the rod 8 there is a locking pin 9 which is transversely mounted in relation to the rod 8.
At one of the sides of the operating mechanism there is also arranged a gate 10, in which one end of the locking pin 9 is located. The gate 10 presents a number of vertical shoulders which for certain predetermined positions of the shift lever interact with the locking pin 9 in a blocking manner if the button 7 is not activated, i.e. pushed downwardly, since this button 7 is affected by an upwardly directed spring force.
FIGS. 1 and 2 show the operating mechanism when the shift lever 1 is located in the park position. The locking pin 9 is then situated in an end position of the gate 10. To be able to move the car it is now required that the shift lever be differently positioned. This implies that the shift lever 1 has to be moved in a direction towards the other end of the gate 10, i.e. to the right-hand side of FIG. 1. The downwardly directed shoulder of the gate hinders the locking pin 9 against such a movement if the button 7 is not activated first, whereby the locking pin 9 is moved downwardly below said shoulder.
FIG. 3 shows an operating mechanism according to FIGS. 1 and 2, which mechanism is arranged with a locking device 15, 16 in accordance with the invention. Also in this figure the locking pin 9 is shown in the park position of the gate 10. Further, there is a blocking device 15, which is rotatably mounted about a substantially horizontal shaft 17. This blocking device cooperates partly with the locking pin 9, and partly with a solenoid 16. The solenoid 16 comprises a moveable solenoid anchor 161 and a coil 162. On the end of the solenoid anchor 161 there is a protruding pin 163. The solenoid 16 is affected by the core with a force which acts in a direction coming out of the paper of FIG. 3. In FIG. 3 the solenoid anchor 161 is in a protruding position which prevents the blocking device 15 from being moved out of its first position (see also FIG. 4). In this first position an upwardly directed edge 152 of the blocking device 15 hinders a downwardly directed movement of the locking pin. Accordingly, it is not possible to depress the button 7 in this position. The solenoid 16 works in such a manner that when activated, it causes the solenoid anchor 161 to move inwardly as shown in FIG. 3 (see also FIG. 5).
In a preferred embodiment the solenoid 16 is interconnected with a relay which controls the brake light. Accordingly, when the ignition is on and the brake pedal is depressed the brake relay will be activated, resulting in an activation of the solenoid 16 and the solenoid anchor 161 is consequently moved inwardly into the coil 162. The solenoid anchor 161 hereby moves away from its locking position where it locks the blocking device 15 to a position where it releases the blocking device 15. As long as the brake is activated the solenoid anchor is maintained in this position where it releases the blocking device 15. Movement of the blocking device 15 is no longer hindered by the solenoid anchor 161. If the button 7 is activated in this state, this leads to a downward movement of the locking pin 9 and, accordingly, also a rotation of the blocking device 15 in a clockwise direction, which movement is directly controlled by the movement of the locking pin 9 since this, preferably with minor play, is positioned in a recess 157 formed between protruding side edges 151, 152, which are adapted-.to the configuration of the locking pin 9. After having completely depressed the button 7 and thereby rotated the blocking device 15, the shift lever 1 is released and can be moved.
When the shift lever 1 is repositioned in the park position, the locking pin 9 will be steered by the gate 10 and will enter into the recess 157 and thereby return the blocking device 15 to its first position by means of an upwardly directed force acting on the edge 151 of the blocking device. The solenoid anchor 161 can then be repositioned in its locking position.
The second end position of the blocking device is defined by the interaction between a recess 153 formed in the blocking device 15 and the pin 163 which protrudes from the solenoid anchor 161.
FIG. 3 shows that a releasing device 18 is rotatably arranged about a substantially horizontal pivot 19. This releasing device has an upper part 181 which is grippable and which, preferably, is positioned closely underneath the bristle-equipped opening for the shift lever 1. At the opposite side of its center of rotation 19 the releasing device 18 presents a protruding portion 182. This protruding portion 182 has a lower edge 183 which is tapered and which is intended to cooperate with a tapered part 164 of the solenoid anchor 161.
If there is a power-cut there is no possibility of activating the solenoid. Consequently, the blocking device 15 remains in its blocking position, where it blocks the locking pin 9, despite activation of the brake pedal and the button 7. Accordingly, it is difficult to move the car under such circumstances, since a mechanical arrangement (not shown) normally excludes the possibility of towing the car when the shift lever is positioned in the park position.
In order to also provide for the possibility of moving the car in an easy manner under these circumstances, the releasing device 18, in accordance with the invention functions as follows. The upper part 181 of the releasing device is gripped, preferably by introducing a finger through the bristle of the opening of the operating mechanism. Thereafter the releasing mechanism 18 is rotated in a counterclockwise direction by applying an upwardly directed force to the upper part 181. This force is transmitted to the oppositely positioned protruding portion 182 of the releasing mechanism 18. The lower, tapered edge 183 of the protruding portion 182 then interacts with the tapered edge 164 of the solenoid anchor 161. The more the releasing mechanism 18 is rotated, the more the solenoid anchor is pressed into the coil 162. Hence the solenoid anchor 161 is depressed. Thereafter the blocking device 15 can be pivoted out of its blocking position by means of depressing the button 7 and thereby moving the locking pin 9 out of its locking position in the gate 10. Consequently a different shift lever position can be chosen, e.g. the neutral position (N), in which the car can be moved.
In FIG. 4 a side-view shows in greater detail the active position of the solenoid anchor 161 when this is located in that position where it locks the blocking device 15. Further, it is shown that the releasing mechanism 18 has its lower, tapered edge 183 located above the tapered portion 164 of the solenoid anchor.
In FIG. 5 the locking mechanism is shown in that position where it releases the blocking device 15. Normally, the solenoid anchor is moved into this non-locking position by activation of the brake pedal, which activation results in the solenoid anchor 161 being pulled into the coil 162. Thereafter the blocking device 15 can be rotated, together with the locking pin 9, into the releasing position, a position which is defined by means of a protruding pin 163 on the solenoid anchor 161.
FIG. 5 also shows that this position of the solenoid anchor 161, in which it releases the blocking device 15, can also be obtained after activation of the releasing mechanism 18, whereby the lower, tapered edge 183 of the protruding portion 182, by means of a camming action on the tapered part 164 of the solenoid anchor, can depress the anchor 161 into the coil 162.
In FIG. 6 there is shown a drawing in detail of a preferred embodiment of the blocking device 15. It is shown that the blocking device 15 preferably consists of two elements 155, 156. One of the elements 156, which includes the pivot point 17, presents an edge 151 which interacts with the locking pin 9 in a manner described above. Further, this element 156 of the blocking device 15 presents a recess 157 in an area adjacent said edge 151, one side of the recess being defined by edge 151 and the opposite side of the recess being defined by an upwardly directed edge 152, of the main body of this element 156. The second element of the blocking device 15 is especially designed for interaction with the solenoid anchor 161. This element 155 is fitted to an edge portion of the other element 156 in an appropriate manner. This second element 155 partly consists of sub-surfaces 154 formed in an arc, the radius of which preferably corresponds to the radius of the solenoid anchor 161. Further, this second element 155 comprises a recess 153 which extends along an arc having a shape determined by the distance between the recess 153 and the center of rotation 17 of the blocking device 15. The prior mentioned surface 154 of this second element 155 defines the first position of said blocking device 15 and the inner end surface of said recess 153 defines the second position of the blocking device 15.
In FIG. 7 and 8 the release mechanism 18 is shown in more detail. It is shown that the release mechanism 18 comprises a plate-like element which comprises said protruding portion 182 and the pivot center 19, by means of which the release mechanism is arranged in a pivoting manner. On the opposite side of the pivot center 19 in relation to said protruding portion 182 there is a grippable part 181. This grippable part preferably consists of a device which is parallelly arranged in relation to the axis of pivot center 19. In order to provide a support for said device 181 there is at its other end a further plate-like element 184 and a spacer 183 therebetween having a recess 185. This recess 185 makes it possible to reach and grip the grippable device 181, e.g. with a finger.
FIG. 9 and 10 show principally the same subject-matter as FIG. 4 and 5. The embodiment according to FIG. 9 and 10, however, is more preferred. Firstly, it is shown that the plate 10 which includes the gate is also used as a means for centering the solenoid anchor 161 by means of its pin 163 which is moveable in a hole in said plate 10. Further, the solenoid anchor 161 has a flange 165 which interacts with a protruding edge 12 when the solenoid is in its retracted position. In its protruding position, which is shown in FIG. 9, the limit is defined by the inner surface of the wall 10. Moreover it is shown that both the release mechanism 18 and the front portion 155 of the blocking device are located in the same plane and that the release mechanism 18 and the blocking device 15 are positioned between two walls 10,11 in order to obtain exact steering thereof. The principal manner of function is the same as has been described in connection with FIG. 4 and 5. A small difference, however, is to be found. Since both the front part 155 of the blocking device and the release mechanism 18 are located in the same plane, the release mechanism 18 is pushed away when the button 7 is activated and the front part 155 of the blocking device is then moved towards that position where the protruding portion 182 of the release mechanism was situated.
The invention is not limited by what has been presented by the above described preferred embodiments, but can be varied within the scope of the following claims.
Hence, it is for example not necessary to have a rod for transmitting the force from the button 7 to the locking pin 9, but it is also possible to use a wire which runs about a wheel, in order to obtain the same movement. Other possible changes could be to supply the operating mechanism with several corresponding blocking devices or to adapt one and the same blocking device to block the pin in two different positions.
Further, it is possible to equip the side of the blocking device 15 with surfaces 151,152 interacting with the locking pin 9 instead of a recess 157 in the blocking device 15, e.g. by means of welding a horseshoe-like part on it at the location where the recess should be placed. | 4y
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This application is a continuation of non-provisional patent application Ser. No. 11/960,908, filed Dec. 20, 2007 (Now U.S. Pat. No. 7,966,502), which is incorporated by reference herein, in its entirety, for all purposes.
BACKGROUND
1. Field of the Invention
The present invention relates generally to Power over Ethernet (PoE) and, more particularly, to a system and method for enabling PoE for legacy devices.
2. Introduction
The IEEE 802.3af and 802.3at PoE specifications provide a framework for delivery of power from power sourcing equipment (PSE) to a powered device (PD) over Ethernet cabling. Various types of PDs exist, including voice over IP (VoIP) phones, wireless LAN access points, Bluetooth access points, network cameras, computing devices, etc.
In the PoE process, a valid device detection is first performed. This detection process identifies whether or not it is connected to a valid device to ensure that power is not applied to non-PoE capable devices.
After a valid PD is discovered, the PSE can optionally perform a power classification. In a conventional 802.3af allocation, each PD would initially be assigned a 15.4 W power classification after a Layer 1 discovery process. An optional classification process could then reclassify the PD to a lower power level. In more complex PoE schemes, a Layer 2 classification engine can be used to reclassify the PD. Layer 2 classification processes can be included in PoE systems such as 802.3af, 802.3at or proprietary schemes. In general, Layer 2 communication (e.g., LLDP) can be used to enable a determination of an amount of power to be allocated to a PD. Where a PD such as a computing device has rapidly changing power needs, the Layer 2 communication can be used to transmit various power management information relevant to the PD's current or anticipated needs. Examples of such power management information include battery information, computing device component information, external device information, user information, application information, or the like.
Legacy computing devices (e.g., laptop computers) that have limited or no PoE functionality typically represent a large percentage of the installed base of devices. In rolling out PoE functionality into a corporate environment, the upgrading of the large installed base of legacy devices represents a prohibitive expense. What is needed therefore is a mechanism that enables PoE functionality for such legacy devices.
SUMMARY
A system and/or method for enabling PoE for legacy devices, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
In order to describe the manner in which the above-recited and other advantages and features of the invention can be obtained, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:
FIG. 1 illustrates an embodiment of a PoE system.
FIG. 2 illustrates an embodiment of a PoE accessory.
FIG. 3 illustrates another embodiment of a PoE accessory.
FIG. 4 illustrates an example mechanism of generating a power request and priority.
FIG. 5 illustrates a flowchart of a process of enabling PoE for legacy devices.
DETAILED DESCRIPTION
Various embodiments of the invention are discussed in detail below. While specific implementations are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without parting from the spirit and scope of the invention.
The deployment of power over Ethernet (PoE) systems in an enterprise environment is expected to produce significant benefits. By eliminating the reliance on AC power cords, devices can be flexibly deployed throughout the enterprise environment using a single Ethernet cable for connectivity. This flexibility in deployment also produces significant cost savings as excess electrical wiring, conduits, and outlets need not be installed.
As noted, one example of a device that can benefit from the installation of a PoE system is a computing device. In general, computing devices that are connected to enterprise networks are often connected on a non-permanent basis. For example, a corporate conference room can be designed with network cabling and corresponding power outlets to support the computing devices of 5-20 conference participants. With a PoE system installed, many of the power outlets can be eliminated as power can be alternatively supplied through the existing Ethernet connection.
In realizing the benefits of a PoE system, a computing device would require the inclusion of certain PoE functionality. FIG. 1 illustrates those PoE elements that would enable a computing device to operate as a PD. As illustrated, the PoE system includes power sourcing equipment (PSE) 120 that transmits power to device 130 . Power delivered by the PSE to device 130 is provided through the application of a voltage across the center taps of transformers that are coupled to a transmit (TX) pair and a receive (RX) pair of wires carried within an Ethernet cable. In general, the TX/RX pair can be found in, but not limited to structured cabling. The two TX and RX pairs enable data communication between Ethernet PHYs 110 and 131 in accordance with 10BASE-T, 100BASE-TX, 1000BASE-T, 10GBASE-T and/or any other layer 2 PHY technology.
As is further illustrated in FIG. 1 , device 130 includes PoE module 132 . PoE module 132 includes the electronics that would enable computing device 130 to communicate with PSE 120 in accordance with a PoE standard such as IEEE 802.3af, 802.3at, legacy PoE transmission, or any other type of PoE transmission. Device 130 also includes pulse width modulation (PWM) DC:DC controller 133 that controls power FET 134 , which in turn provides constant power to load 135 .
In the example of the IEEE 802.3af standard, PSE 120 can deliver up to 15.4 W of power to a plurality of PDs (only one PD is shown in FIG. 1 for simplicity). In the IEEE 802.at specification, on the other hand, a PSE can deliver up to 30 W of power to a PD over 2-pairs or 60 W of power to a PD over 4-pairs. Other proprietary solutions can potentially deliver even higher levels of power to a PD. In general, high power solutions are often limited by the limitations of the cabling.
As would be appreciated, the incorporation of PoE elements 132 , 133 , 134 into an installed base of computing devices would be prohibitive. This is especially true when considering that the PoE functionality does not represent a core function of the computing device, but rather a measure of convenience for users. The principles of the present invention seek to address the need to accelerate the rollout of PoE functionality in a manner that does not require an overhaul of an installed base of devices.
FIG. 2 illustrates an embodiment of an accessory 210 that can be used to enhance the PoE functionality of a device. In general, the device may have no PoE functionality resident therein, or could have a lower level of PoE functionality that is sought to be upgraded. Regardless of the level of PoE functionality of the device, the principles of the present invention can be used to enhance the level of PoE functionality in a low cost manner.
In general, accessory 210 is designed to provide an interface between a PSE and device 220 , which needs upgraded PoE functionality. In the illustrated embodiment, accessory 210 includes transformers 211 designed to receive the wire pairs in an Ethernet cable. The TX and RX wire pairs are passed on to Ethernet port 212 , while the center taps of transformers 211 are coupled to PD 216 . As noted above, PD 216 can include a PoE module, which contains a signature detection component that enables detection by the PSE, a power controller that controls delivery of power received from the PSE, and circuitry that enables the relay of power demand information to the PSE (e.g., via Layer 2 communication). As illustrated, the resulting power that is extracted by PD 216 from the Ethernet link is forwarded to a power port on device 220 . In one embodiment, the power port can represent a standard DC power input port on device 220 .
In one embodiment, accessory 210 can be designed to simply produce a DC power output from an Ethernet input. No other communication port need be used. In one scenario, this embodiment can be used in those contexts where device 220 has no PoE functionality. For example, accessory 210 can be designed with basic 802.3af Layer 1 functionality that is designed to get as much power as possible from the PSE to deliver to device 220 . In this example, accessory 210 need contain only transformers 211 and PD 216 . In another example, accessory 210 can be designed with more advanced Layer 2 functionality to negotiate a power request on behalf of device 220 . In this example, accessory 210 could be used to augment non-existent PoE functionality or primitive Layer 1 PoE functionality in device 220 . To facilitate this type of functionality, accessory 210 would also include Ethernet port 212 and a processor (not shown) to perform the power request negotiation. In yet another example, accessory 210 can be applied to a legacy device that may already have basic two-pair PoE functionality (e.g., 802.3af). In this example, accessory 210 can be used to provide additional power via alternative pairs (e.g., 802.3at), wherein the additional amount of power can be modulated via Layer 2 communication.
In another embodiment, accessory 210 can be designed to support a communication connection with device 220 in addition to the power connection discussed above. To support the communication connection, accessory 210 also includes switch 213 . In the illustrated embodiment, switch 213 is at least a three-port switch that can support Ethernet port 212 , communication port 214 , and internal port 215 . Ports 212 , 214 , and 215 can support full duplex links such that traffic can be coming from either direction at the same time. Traffic can also be switched to two ports simultaneously. For example, internal port can add traffic to either or both of ports 212 , 214 , or receive traffic from either or both of ports 212 , 214 . In one example, traffic to/from Ethernet port 212 and internal port 215 can support PoE power request/priority negotiation between accessory 210 and the PSE, while traffic to/from internal port 215 and communication port 214 can support the exchange of power management information between accessory 210 and device 220 .
As noted, the principles of the present invention can also be applied to legacy PDs that lack Layer 2 communication. In the embodiment of FIG. 3 , accessory 320 can incorporate PD 322 that faces an advanced (e.g., 802.3at) PSE 310 , and PSE 324 that faces legacy (e.g., 802.3af) PD 330 . Accessory 320 can then power PSE 324 , initially requesting the power it detects on PD 330 via Layer 1, and requesting that amount of power from PSE 310 using PD 322 . In one scenario, accessory 320 can then override the hardware classification of legacy PD 330 and provide the required dynamic power, which can be negotiated over the communication channel between accessory 320 and legacy PD 330 , to advanced PSE 310 using PD 322 .
In one embodiment, communication port 214 is an Ethernet port. In this embodiment, Ethernet traffic from the switch can be passed without modification from port 212 to port 214 , and on to device 220 . In other embodiments, communication port 214 can be embodied as a Bluetooth port, serial port, parallel port, USB port, or any other device-to-device communication mechanism.
As noted, communication port 214 can be used to support the exchange of power management information between accessory 210 and device 220 . In one example, device 220 can be configured to provide accessory 210 with information that enables accessory 210 to determine the power needs of device 220 . For example, device 220 can be configured to transmit parameters such as battery capacity, battery life, etc. that enables accessory 210 to make a priority decision based on a priority and allocation algorithm.
In another example, device 220 can be configured to perform a priority and allocation algorithm using parameters known to device 220 . FIG. 4 illustrates an example of such a mechanism that can be implemented in software, hardware, and/or firmware. As illustrated, various power management information can be used as inputs to power need determination 410 . In this example, the power management information includes user parameters (e.g., management, engineering, admin, etc.); computing device parameters (e.g., battery capacity, battery life, system states, processor states, device states, etc.); application parameters (e.g., mode of operation, application load, etc.); IT parameters (e.g., computing device model, IT policies, performance characteristic data, etc.); and network parameters (e.g., length of cable, type of cable, etc.). With this set of power management information, power need determination 410 can then produce a power request and power priority for the device. This power request/priority information can then be communicated to accessory 210 for use in performing a power negotiation with the PSE. With this framework, device 220 plays a role in the PoE process, yet need not have the PoE hardware installed within. Device 220 can therefore leverage the various PSE deployments/upgrades without being reconfigured in hardware. Support for such PSE deployments/upgrades is enabled through the functionality of accessory 210 .
To further illustrate the features of the present invention, reference is now made to the flowchart of FIG. 5 . As illustrated, the process of FIG. 5 begins at step 502 where the PoE accessory is attached to a device needing PoE enhancement. In one example, the attachment is based solely on a DC power connection. In another example, the attachment is based on a DC power connection and a communication connection (e.g., Ethernet, Bluetooth, serial, parallel, USB, etc.). At step 504 , the accessory is then coupled to a PSE via an Ethernet cable.
The positioning of the accessory between the PSE and the device enables the accessory to act as a PD on behalf of the device. In other words, the accessory can be detected as a PD using the signature detection component incorporated within the accessory. Upon detection of the accessory as a PD, the accessory can then negotiate a power request on behalf of the device at step 506 . In one embodiment, the accessory can negotiate the power request independently of the device. In this embodiment, the accessory can request the maximum allowed power that is available from the PSE. Whatever amount of power that is approved can then be transferred to the device using the DC power connection. In another embodiment, the accessory can negotiate the power request using input from the device. In one example, the device can forward power management parameters to the accessory for determination of a power request/priority. In another example, the device can determine the power request/priority using various power management information available to the device, and forward the determined power request/priority to the accessory. Regardless of the type or amount of input that is provided by the device to the accessory, the accessory represents a low-cost mechanism of leveraging new or upgraded PoE capabilities of the PSE without requiring commensurate upgrades at the device.
At step 508 , after the accessory has negotiated the power request on behalf of the device, the accessory can then extract power that is delivered to the accessory via the Ethernet cable. The power is extracted using the power controller and power FET in the accessory and delivered to the device at step 510 using the DC power connection.
As has been described, the accessory of the present invention can provide the benefits of the latest PoE technologies to any type of device that needs power. These benefits can be realized without requiring a hardware upgrade of the device. Specifically, any device that has an external DC power port can potentially benefit from the principles of the present invention.
These and other aspects of the present invention will become apparent to those skilled in the art by a review of the preceding detailed description. Although a number of salient features of the present invention have been described above, the invention is capable of other embodiments and of being practiced and carried out in various ways that would be apparent to one of ordinary skill in the art after reading the disclosed invention, therefore the above description should not be considered to be exclusive of these other embodiments. Also, it is to be understood that the phraseology and terminology employed herein are for the purposes of description and should not be regarded as limiting. | 4y
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to a battery cooling structure for cooling a battery mounted in a vehicle.
[0003] 2. Description of Related Art
[0004] Vehicles such as hybrid vehicles (HV) and electric vehicles (EV) run by driving a motor using electric power from a battery. Therefore, a battery that ensures the necessary electric power is mounted in the vehicle. Also, in order to improve the battery mounting space efficiency, Japanese Patent Application Publication No. 2010-036723 (JP 2010-036723 A) proposes to house the battery under a rear seat. Also, a battery generates heat as it charges and discharges. In particular, with a battery for a vehicle, large current often flows, so the amount of heat generated is large. If the temperature of the battery becomes high, the battery will deteriorate, so it is necessary to provide a structure to cool the battery. JP 2010-036723 A describes a structure that draws air into a vehicle cabin from in front of a lower portion of the rear seat, and discharges this air out of the vehicle from behind a lower portion of the rear seat.
SUMMARY OF THE INVENTION
[0005] Here, if exhaust air that has cooled the battery under the rear seat is discharged out of the vehicle as it is, the exhaust passage is able to be short, which is advantageous in terms of space, and pressure loss is low, so it is efficient. However, with this configuration, an exhaust vent is arranged in a relatively low position, so sufficient consideration must be given so that foreign matter and water and the like on the road does not get into the battery pack.
[0006] Therefore, one aspect of the invention relates to a battery cooling structure for cooling a battery mounted in a vehicle. This battery cooling structure includes a battery pack, an air supplying device, and an air exhausting device. The battery pack houses the battery in an internal space, and is arranged under a rear seat of the vehicle. The air supplying device is configured to send cooling air to the battery pack. The air exhausting device is configured to discharge exhaust air from the battery pack. An exhaust vent that discharges the exhaust air is provided in a floor surface in a rearward space behind the rear seat in the vehicle. The exhaust vent is configured to discharge the exhaust air from the battery pack upward into the rearward space from the exhaust vent.
[0007] Also, in the battery cooling structure described above, the rearward space may be a luggage space of the vehicle, and a spare tire housing space may be provided in a lower portion of the luggage space. Also, the exhaust vent may be positioned in front of the spare tire housing space.
[0008] Also, in the battery cooling structure described above, the air exhausting device may have an exhaust air duct that extends from the battery pack to the rearward space, and an exhaust port of the exhaust air duct may be provided underneath the floor surface and open into a discharge duct that extends in a vehicle width direction. The discharge duct may have a discharge port in a position planarly offset with respect to the exhaust port on a front surface side of the discharge duct. After exhaust air discharged from the exhaust port of the exhaust air duct flows through the discharge duct in a direction parallel to the floor surface in the vehicle width direction, the exhaust air may be discharged upward into the rearward space via the discharge port and the exhaust vent.
[0009] Also, in the battery cooling structure described above, the discharge port of the exhaust air duct may be covered by cloth. Also, in the battery cooling structure described above, the discharge port of the exhaust air duct may be covered by lattice. Furthermore, in the battery cooling structure described above, the discharge port of the exhaust air duct may be provided in a direction excluding in front, with respect to a vehicle longitudinal direction, of the exhaust port, and a closed portion may be provided in front, with respect to the vehicle longitudinal direction, of the exhaust port.
[0010] This kind of battery cooling structure makes it possible to effectively inhibit foreign matter and the like from getting in through the exhaust vent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Features, advantages, and technical and industrial, significance of exemplary embodiments of the invention will be described below with reference to the accompanying drawings, in which like numerals denote like elements, and wherein:
[0012] FIGS. 1A and 1B are views illustrating the flow of supply air and exhaust air to and from a battery pack according to a battery cooling structure of one example embodiment of the invention;
[0013] FIG. 2 is a view of the exterior of the battery pack and a duct according to the battery cooling structure of the example embodiment;
[0014] FIGS. 3A, 3B, and 3C are views of the structure of an exhaust air duct behind a rear seat according to the battery cooling structure of the example embodiment; and
[0015] FIGS. 4A, 4B, and 4C are views of the exterior of the exhaust air duct, a supply air duct, a blower, and an intake air duct according to the battery cooling structure of the example embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0016] Hereinafter, example embodiments of the invention will be described with reference to the accompanying drawings. The invention is not limited to the example embodiments described here.
[0017] First, the structure related to supply air and exhaust air in a battery cooling structure of this example embodiment will be described. FIGS. 1A and 1B are views of the structure related to the flow of supply air and exhaust air to and from a battery pack in this example embodiment.
[0018] A rear seat 10 includes a seat cushion 10 a, a seatback 10 b, and a battery housing space 10 c below the seat cushion 10 a. The front and sides of the battery housing space 10 c are surrounded by a lower trim 12 . Also, a vehicle body 14 is positioned on a bottom surface side of the battery housing space 10 c.
[0019] A battery pack 20 is arranged inside of the battery housing space 10 c, and a battery stack 22 is arranged inside of this battery pack 20 . This battery stack 22 is formed by a plurality of battery modules 24 connected together in series.
[0020] The inside of the battery pack 20 is sealed by a lower case and an upper cover. A supply air flow path is formed above the battery stack 22 and an exhaust air flow path is formed below the battery stack 22 .
[0021] A supply air duct 26 is connected to a rear side of the supply air flow path above the battery stack 22 inside the Battery pack 20 , as shown in FIG. 1A , and this supply air duct 26 extends toward the rear and is connected to a blowing side of a blower 28 .
[0022] An exhaust air duct 30 is connected to a rear side of the exhaust air flow path below the battery stack 22 of the battery pack 20 , as shown in FIG. 1B , and this exhaust air duct 30 extends toward the rear, with an exhaust port 32 opening upward.
[0023] A rear side (back) space of the seatback 10 b of the rear seat 10 serves as a luggage space 40 . A floor surface of the luggage space 40 is formed by a deck board 42 . This deck board 42 is placed in the luggage space 40 , so it is able to be picked up and removed. A spare tire space 44 within which a spare tire is housed is provide below the deck board 42 , and a spare tire is housed here: Also, an accessories compartment such as a shelf is provided below the deck board 42 , at a front upper portion in the, spare tire space 44 .
[0024] Also, the blower 28 described above is arranged behind the rear seat 10 and in front of the spare tire space 44 . That is, there is a space below the luggage space 40 to the rear of the rear seat 10 and in front of the spare tire space 44 , and the blower 28 is arranged here. An intake air duct 60 (see FIG. 2 ) and the supply air duct 26 are connected to this blower 28 . Also, a rear side portion of the exhaust air duct 30 and the exhaust port 32 are provided. A discharge duct 48 that extends in a vehicle width direction is provided on an upper portion of this exhaust port 32 , and a discharge port panel 50 is provided on a front surface of this discharge duct 48 . This discharge port panel 50 has a closed portion and an open portion. The open portion is an exhaust port. An exhaust vent 54 formed by a gap between a tip end of the deck board 42 and a back surface of the seatback 10 b above this exhaust port is open to the luggage space 40 . A seat member 52 is provided between a lower front end of the discharge duct 48 and the back surface of the seatback 10 b so that articles will not fall down.
[0025] Here, FIG. 2 is a perspective view of the battery pack 20 and a duct. In this case, the intake air duct 60 is connected to the intake side of the blower 28 . This intake air duct 60 draws in air from an inlet 62 in a side surface on the door side of lower trim of the rear seat 10 . In FIG. 2 , the seat cushion 10 a and the lower trim 12 and the like shown in FIGS. 1A and 1B have been removed, but the inlet 62 is open to the door-side side surface of the lower trim 12 . Cloth or lattice or the like is placed over the front surface of the inlet 62 to prevent foreign matter from getting in from the outside.
[0026] In this way, the intake air duct 60 , the supply air duct 26 , and the exhaust air duct 30 are arranged in order from the door side toward the inside, in the space below the seat cushion 10 a of the rear seat 10 .
[0027] Next, the structure to the rear of the battery cooling structure of this example embodiment will be described. Here, FIGS. 3A, 3B, and 3C are views of the structure of a portion where the exhaust port 32 opens out. In FIG. 3A , the top of the drawing is toward the vehicle rear and the side of the drawing is in the vehicle width direction. In FIG. 3B , the top of the drawing is upward with respect to the vehicle, and the side of the drawing is in the vehicle width direction. In FIG. 3C , the top of the drawing is upward with respect to the vehicle, the left side of the drawing is toward the vehicle front, and the right side of the drawing is toward the vehicle rear.
[0028] In this way, the exhaust port 32 is provided in front of an accessories compartment 46 , and is open to a bottom surface of the discharge duct 48 that extends in the width direction of the vehicle. This discharge duct 48 has the discharge port panel 50 on the front side. This discharge port panel 50 has a discharge port 50 a that is covered by cloth or lattice or the like, and a closed portion 50 b. This discharge port 50 a is provided somewhere other than on (i.e., in a location excluding) the front side of the exhaust port 32 . The front of the exhaust port 32 is the closed portion 50 b. The discharge port panel 50 may be formed by a panel in which the discharge port 50 a is formed as an opening, or the closed portion 50 b may be arranged at appropriate intervals so as to form an open portion (i.e., the discharge port 50 a ) therebetween.
[0029] Therefore, after exhaust air from the exhaust port 32 temporarily curves in the width direction of the vehicle, it then flows forward toward the back surface of the seatback 10 b of the rear seat 10 . The exhaust air then passes through the exhaust vent 54 that is the gap between the tip end of the deck board 42 and the back surface of the seatback 10 b, and is discharged upward into the luggage space 40 .
[0030] Cloth or lattice may also be arranged on the upper surface of the exhaust port 32 so that articles will not fall into the exhaust port 32 . Also, the discharge port panel 50 is preferably able to be removed from the discharge duct 48 . Further, the upper end of the exhaust port 32 is flange-shaped and positioned above the bottom surface of the discharge duct 48 . By having this portion extend upward in a pipe-shape, water and the like will not reach the exhaust port 32 even if it gets into the discharge duct 48 .
[0031] Next, the flow of air in the battery cooling structure of this example embodiment will be described. Air inside the vehicle cabin is drawn in from the inlet 62 by driving the blower 28 . This air is drawn into the blower 28 via the intake air duct 60 . Discharged air from the blower 28 is supplied into an upper space (i.e., a supply air flow path) in the battery pack 20 via the supply air duct 26 . The battery stack 22 is arranged inside the battery pack 20 , but because there is a gap between battery modules 24 of the battery stack 22 , the air flows downward through this gap, such that the battery modules 24 are effectively cooled. Here, cooling air is able to be made to pass through this gap between the stacked battery modules 24 by closing off the area between the periphery of the battery stack 22 and a peripheral inside wall of the battery pack 20 .
[0032] Exhaust air is discharged from a lower space (i.e., an exhaust air, flow path) in the battery pack 20 into the luggage space 40 through the exhaust air duct 30 , the exhaust port 32 , the discharge duct 48 , the discharge port panel 50 , and the exhaust vent 54 that is the gap between the tip end of the deck board 42 and the back surface of the seatback 10 b. In this example, the exhaust vent 54 is positioned along almost the entire width in the width direction of the vehicle, but it may also be limited to only a specific portion.
[0033] Next, the individual structures of the battery cooling structure of this example embodiment will be described. In FIGS. 1A and 1B , only one rear seat 10 is shown, but normally there are two rear seats 10 , and battery packs 20 , as well as a mechanism for cooling the battery packs 20 , are arranged with the same configuration under the rear seats 10 , as shown in FIGS. 1A and 1B .
[0034] Here, FIGS. 4A, 4B, and 4C are views of the exteriors of the exhaust air duct 30 , the supply air duct 26 , and the intake air duct 60 , respectively. As shown in FIG. 4A , the exhaust air duct 30 extends toward the rear from a rear end of a lower case that forms a bottom surface of the battery pack 20 . As shown in the drawing, a front end of the exhaust air duct 30 is a flat opening that is vertically narrow (i.e., narrow in the vehicle height direction) and wide (in the vehicle width direction). Air from the whole discharge flow path below the battery stack 22 is discharged from this opening. The width of the exhaust air duct 30 gradually narrows toward the exhaust port 32 , and the exhaust port 32 is a generally square-shaped opening.
[0035] Also, a periphery of an open portion 30 a of the front end of the exhaust air duct 30 is reinforced by a flange portion 30 b. This open portion 30 a is able to be connected to the discharge flow path in an airtight manner by placing the lower side of the flange portion 30 b close against the lower case and holding the upper side of the flange portion 30 b down against the rear side end portion of the battery stack 22 . A side portion of the flange portion 30 b is connected in an airtight manner to an inside wall of an upper cover that covers a side portion and an upper portion of the battery pack 20 . An airtight seal is achieved by arranging a sealant around the flange portion 30 b.
[0036] A more reliable seal is achieved by providing a recessed portion that is recessed downward in two locations as shown in FIG. 4A , on an upper edge portion of the flange portion 30 b, and adjusting the shape of a lower surface of the rear end of the battery stack 22 accordingly. Also, having the recessed portion directly contact the lower edge portion of the flange portion gives the flange portion 30 b sufficient strength.
[0037] The front end of the supply air duct 26 is a flat open portion 26 a that is vertically narrow and wide in the width direction, matching the shape of the upper space (i.e., the supply air flow path) of the battery pack 20 , as shown in FIG. 4B . Also, a flange portion 26 b is formed around the open portion 26 a, and the periphery of this flange portion 26 b is sealed via a sealant between the rear upper end portion of the battery stack 22 and the upper cover of the battery pack 20 . The supply air duct 26 extends toward the rear, while the width thereof gradually becomes narrower. This supply air duct 26 is connected to an air outlet 28 a around the blower 28 . The blower 28 has a cylindrical shape and blows out air drawn in from a side intake port 28 b in a radial direction, and blows out air from the air outlet 28 a provided in a portion of a donut-shaped blowing chamber.
[0038] The intake air duct 60 has a pipe-shape that extends from the front toward the rear, and the rear end of the intake air duct 60 is connected to the intake port 28 b of the blower 28 , as shown in FIG. 4C . The front end is a rectangular-shaped inlet 62 .
[0039] Next, the effects of the example embodiment will be described. In this way, with this example embodiment, the battery pack 20 is housed in the battery housing space 10 c below the seat cushion 10 a of the rear seat 10 , so the battery will not get in the way of other equipment and vehicle space is able to be more efficiently utilized. Also, the discharge port 50 a of the discharge duct 48 is provided right behind the back surface lower portion of the seatback 10 b of the rear seat 10 , so the discharge duct 48 is able to be relatively short, which enables pressure loss there to be small.
[0040] Furthermore, the exhaust port 32 opens into the discharge duct 48 , the discharge duct 48 discharges exhaust air from the discharge port 50 a, and the discharge port 50 a is pointed in a substantially horizontal direction and is covered by cloth or the like, so foreign matter is able to be prevented from getting in from the outside. In particular, the discharge port 50 a is offset from the exhaust port 32 in the width direction, so air discharged upward from the exhaust port 32 temporarily travels in the width direction of the vehicle, and then strikes the back surface of the seatback 10 b from the discharge port 50 a in the front surface and escapes upward. This kind of an air path makes it possible to reliably prevent foreign matter from getting in and the like. Also, the discharge port 50 a is provided over a relatively large area in the vehicle width direction, so pressure loss is able to be reduced with a relatively complex path.
[0041] Exhaust air is discharged into the luggage space 40 from the opening between the deck board 42 and the back surface of the seatback 10 b. Therefore, it is unlikely that this airflow will affect an occupant, so exhaust air will not cause the occupant any discomfort.
[0042] Also, the inlet 62 is on a side lower portion of the rear seat, so it is less likely that the flow of intake air from here will be felt by a leg of an occupant or the like. Moreover, the inlet 62 is pointed at an angle, so the flow of intake air is not that fast. As a result, the intake air will not easily be felt by an occupant, and noise generated by the intake air is also able to be suppressed. | 4y
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CROSSREFEENCES
This application is a continuation in part of the U.S. application Ser. No. 08/982,030, filing date of Dec. 1, 1997, now U.S. Pat. No. 5,798,043.
FIELD OF INVENTION
The invention belongs to biological-abiotic systems for waste treatment, and more specifically is a method for conjugate degradation and reduction of carbonaceous BOD or COD, toxic and recalcitrant organics, and nitrogen and phosphorus, and for minimization of the excess biosolids.
BACKGROUND
Biological processes are routinely used for removing carbonaceous BOD and COD. These processes involve oxidation and reduction steps and biomass synthesis. In the last thirty years, the so-called advanced process modifications were developed to also remove phosphorus and nitrogen. These systems include various combinations of aerobic, fermentation, facultative anaerobic, anoxic, nitrification and denitrification zones. In nitrogen removal systems, the nitrogen containing species, usually ammonia, are biologically oxidized (nitrified) to nitrites and nitrates, following by a biological reduction (denitrification) of nitrites and nitrates to nitrogen and gaseous oxides of nitrogen. Phosphorus removal systems are conducted via, first, exposing the recycle sludge to facultative anaerobic conditions wherein acetic acid is formed and phosphorus is released, and, second, exposing biomass in the sludge to aerobic conditions wherein the so-called luxurious uptake of phosphorus is believed to occur. These systems are described in books "Phosphorus and Nitrogen Removal from Municipal Wastewater, Principles and Practice" Second Edition, Richard Sedlak, Editor, Lewis Publishers, 1991, "Biological and Chemical Systems for Nutrient Removal" A Special Publication, Prepared by the Task Force on Biological and Chemical Systems for Nutrient Removal, Movva Reddy, Chair, Water Environment Federation, 1998, and in patents, for example, U.S. Pat. Nos. 2,788,127, 2,875,151, 3,236,766, 3,964,998, 4,056,465, 4,162,153, 4,183,807, 4,183,808, 4,183,809, 4,183,810, 4,271,026, 4,488,967, 4,500,427, 4,500,429, 4,874,519, 4,867,883, 4,874,519, 4,917,805, 4,948,510, 4,999,111, 5,013,441, 5,022,993, 5,076,928, 5,076,929, 5,098,572, 5,160,043, 5,182,021, 5,213,681, 5,288,405, 5,480,548, 5,601,719, and 5,651,891.
The main problem with biological nutrient removal is that it is difficult to maintain balance between phosphorus and organics needed for the acetic acid production, and between nitrogen species and organics needed in the denitrification processes. Other problems may include low process efficiency, seasonal instabilities due to low temperatures, difficulties with pH control, complex systems, and complex operations. Additionally, the volume and costs of advanced biological reactors far exceed that of the conventional aerobic systems with complete nitrification. In biological phosphorus removal, there is a problem of phosphorus dissolution in the subsequent process steps, for example, during sludge treatment. Advanced biological systems usually require more energy than conventional systems. Large mass and volume of excess biosolids, also known as excess sludge or biomass, is generated.
Phosphorus can be easily removed with reagents, primarily, iron or aluminum ions in forms of insoluble phosphates. The process can be conducted in biological reactors so that little equipment is required. The stoichiometric iron and aluminum requirements are only 0.88 mg Fe and 0.28 mgAl per 1 mg P 2 O 4 . The actual metal requirement is significantly greater. Chemical nitrogen removal involves difficult processes and is not practiced for low nitrogen concentrations in municipal and many industrial wastewater types. A co-precipitation of phosphorus and nitrogen (ammonia) as struvite (MgNH 4 PO 4 ) have also been discussed, but not practiced yet. The use of reagents contributes to the sludge mass. Increased mass of the excess sludge is cited as the argument against chemical phosphorus removal.
Anaerobic, aerobic, and coupled or combined anaerobic-aerobic biological systems are also used for treatment of dilute and concentrated industrial waste for organics and nutrients removal, as well as for removal and destruction of toxic and recalcitrant organics, heavy metals, sulfur containing compounds, and other applications. In these applications, biological processes may suffer problems similar to those experienced with advanced systems and also application specific problems. For example, in some applications, toxicity is a problem, in other applications, odorous constituents are emitted, while in others the process stability is difficult to control.
OBJECTIVES
Accordingly, an objective of the present invention is to provide a simple, reliable, efficient, stable, and economical system for removal of organics, nutrients, and other target constituents, while generating little or no waste biological solids. Other objectives of the present invention will become clear from the ensuing description.
SUMMARY OF INVENTION
The essence of this method is that in biological treatment of wastewater having oxidation and reduction steps, an improvement is provided comprising a step of charging at least one recuperable oxidation-reduction mediator specie. For example, this can be a method of biological wastewater treatment with biomass in a system comprising at least one aerobic biological wastewater treatment step, whereby the target organic and inorganic constituents in the said wastewater and the recuperable oxidation-reduction mediator specie charged in the system become at least partially oxidized to form new biomass, carbon dioxide, water, and nitrites and nitrates, and/or at least one step of oxidizing the said biomass, wherein the said biomass is repeatedly treated in the said aerobic and biomass oxidizing steps, whereby the said recuperable oxidation-reduction mediator species become reduced in the said biomass oxidation step to a lower oxidation state while oxidizing and minimizing biomass.
This can also be a method of biological wastewater treatment with biomass in a system comprising at least one aerobic biological wastewater treatment step, whereby the target constituents in the said wastewater and the recuperable oxidation-reduction mediator species charged in the said system are oxidized to form new biomass, carbon dioxide, water, and nitrites and nitrates and higher valence recuperable oxidation-reduction mediator species, at least one denitrification step, whereby the said nitrites and nitrates are reduced to form gaseous nitrogen forms and the said abiotic species are converted to the lower valence, a step of charging at least one recuperable oxidation-reduction mediator species in the said system. Selected recuperable oxidation-reduction mediator species can precipitate phosphorus as insoluble phosphates from the said wastewater in the said system simultaneously with other process steps. Some ion exchange mediator species can also remove phosphorus via ion exchange mechanisms.
The said wastewater is defined herein as domestic or industrial wastewater, aqueous industrial, agricultural and production materials, industrial, agricultural and production gases, polluted air, gaseous and vent emissions, solid waste, materials of plant, animal, or fossil origin, and solid industrial, agricultural or production streams, and combinations thereof. It is understood that gaseous pollutants can be washed with a liquid and treated in the present system, while solid materials can be converted to slurries with water.
The said aerobic step can be selected from the group comprising oxygen enriched steps (including high purity oxygen), air aerated aerobic treatment, nitrification treatment, to a lesser degree anoxic treatment, denitrification treatment, facultative anaerobic treatment, and combinations thereof. The said biological reduction step can be selected from the group comprising anoxic treatment, denitrification treatment, facultative anaerobic treatment, ferric iron reduction, sulfate reduction, carbonate reduction (methanation), and combinations thereof. The said step of biomass oxidation is preferably anaerobic, ferric ion reduction, or facultative anaerobic step. These steps are given to the skillful in art as benchmarks for orientation and approximate evaluation of the oxidation-reduction conditions in the system.
The said recuperable oxidation-reduction mediator species with variable oxidation state can be selected from the group comprising zero valence metal pieces, metallic ions, metal-containing oxy ions, nonbiodegradable and insoluble inorganic constituents with variable oxidation-reduction states, nonbiodegradable and insoluble organic constituents with variable oxidation-reduction states, and combinations thereof. The said metallic and metal-containing species include metals selected from the group comprising iron, nickel, cobalt, manganese, vanadium, and combinations thereof. Ion exchange resins with oxidation-reduction groups, also known as redox exchangers, and similarly activated and modified natural organic and inorganic materials known to skillful in art or specifically developed in the future for particular applications can also be used as recuperable abiotic species in this process.
Iron is practicable recuperable abiotic specie. A simplified pH-potential diagram for iron is shown in FIG. 1. More detailed diagrams can be found, for example, in "Atlas of Electrochemical Equilibria in Aqueous Solutions" by Marcel Pourbaix, Pergamon Press, 1966. FIG. 1 shows lines a and b separating the domain of stability of water and the oxidation and reduction domains of water. A range of pH from 6 to 8.5 generally considered as acceptable for biological processes is hatched in FIG. 1. Within this range, iron is found in a higher valence as an insoluble Fe(OH) 3 , or as divalent ions Fe 2+ , and at lower oxidation-reduction potentials (ORP) in the presence of sulfides, as ferrous sulfide, and at pH greater than approximately 8.35 as ferrous carbonate. The iron species of the main interest here are trivalent (ferric) and divalent (ferrous) forms. In this method, ferric and ferrous species are respectively an oxidant and a reducing agent. Solid line in FIG. 1 separates oxidizing and reducing conditions for these species. Accordingly, process steps conducted at pH and ORP above the solid line are called herein oxidation steps, and those below solid line are reduction steps. The domain of metallic (zero-valence) iron is located low in FIG. 1 beyond the domain of water stability. Therefore, metallic iron can be added to the system and converted into recuperable ferric and ferrous species, but metallic iron cannot be recuperated.
In aerobic, nitrification, and denitrification steps, and sometimes in facultative anaerobic steps of the present method, ferrous ions are oxidized to ferric ions either by oxygen supplied through aeration or via reduction of nitrites and nitrates mainly to molecular nitrogen, or by halogenated organics. In biomass oxidation, it is oxidized mainly to carbon dioxide and water by ferric ions becoming ferrous ions. Thus formed ferrous and ferric ions are repeatedly used in the said aerobic, nitrification, denitrification, and the said biomass oxidation steps. Insoluble ferric forms are enmeshed with the sludge and retained (recuperated) in the system. In addition to the benefits of mediating oxidation-reduction steps in biological processes, ferric hydroxide is also a coagulant for the biomass. It beneficially enhances sludge separation. In batch processes, the repetition of these steps occurs in the same space on a time sequence. In continuous flow systems, the steps are repeated in spatially separated steps in different reservoirs by recycling the sludge composed of biomass and the said abiotic species in solid form between these steps. The recycled biomass can be separated from the wastewater being treated and further directed for the repeated treatment, or it can be directed for the repeated treatment together with the said wastewater as mixed liquor. Alternatively, the spatial separation can be provided due to concentration gradients within a single tank with nonhomogeneous mixing. Nonhomogeneous mixing can be either due to concentration gradients within incompletely mixed tank, or due to unsteady-state (time variable) concentration gradients within biological flocs and films. Therefore, it is biomass (or sludge including the biomass and insoluble forms of oxidation-reduction mediator species) that is repeatedly treated in the at least one step of oxidizing terminal reducing agents (hydrocarbons and/or biomass) wherein the recuperable oxidation-reduction species are reduced, and at least one step of reducing terminal oxidizers (oxygen, air, or nitrites and nitrates) whereby the recuperable oxidation reduction mediator species are oxidized, while the wastewater may be, but not necessarily, repeatedly treated in these steps. The recuperable oxidation-reduction mediator species function as intermediate oxidation-reduction agents. In prior art systems for phosphorus removal, iron concentration is provided at the level needed to remove phosphorus. This is usually a small concentration. Moreover, iron used for binding phosphates is rapidly evacuated from the system and new iron needs to be continuously fed. In the present system, concentration of iron ions can be from a fraction of 1 g/L to several grams per liter, that is at least one to several orders of magnitude greater than in phosphorus removal systems. At these concentrations, a constantly present pool of charged iron is created in the system. At concentration of 1 g Fe 3+ /L, the estimated equivalent "oxidation capacity" as compared to oxygen is 1×(8/56)=0.143 g O/L, or 143 mg O/L (where 8 and 56 are atomic weights of oxygen and iron per 1 electron). This "oxidation capacity" is much greater than that of oxygen in conventional air aeration systems and exceeds that of high purity oxygen systems by a factor greater than two. In conventional biological denitrification processes, the "reducing power" of ferrous ions used in denitrification steps can also exceed that of the purchased organics. Unlike organics, for example methanol, in denitrification processes, recuperable iron ions do not constitute BOD that needs to be removed after the conventional denitrification step. Recyclable iron ions do not contribute to the growth of biomass in denitrification and post denitrification steps as organics do. On the contrary, the biomass is oxidized in the recuperation cycle of iron ions. Significantly increased oxidation-reduction capacity (or driving force) in the system results in dramatic increases in rates and efficiency of denitrification and sludge oxidation steps. It is understood that iron is used here as an example and many other recuperable oxidation-reduction mediator specie types can also be used. It is also understood that when selecting the said species, skillful in art can consider physical-chemical and other properties of specific recuperable species.
Cobalt and nickel are other practicable species to be used in the present method. A simplified pH-ORP diagram for cobalt is given in FIG. 2. Similarly to iron, cobalt and nickel exist in zero-, di-, and tri-valence states. In contrast to iron, nickel and cobalt in zero-valence state can exist within the domain of water stability. Moreover, a portion of the area of stability of cobalt and nickel within the stable water domain corresponds to conventional anaerobic processes, particularly, many methanogenic processes having ORP approximately -250 to -400 mV. Therefore, metallic (zero-valence) cobalt, or nickel, can be formed in anaerobic processes from tri-, and di-valence forms. Accordingly, these species can be used in the present method in three oxidation states and form three zones separated by solid lines that can be used as oxidation and reduction zones. Zero-valence species are very powerful reducing agents for many toxic and recalcitrant constituents found in many wastewater, solid wastes, contaminated soils, and other wastes. These reductions are described in U.S. Pat. No. 5,348,629 and co-pending patent application No. PCT/US98/08649 which are made a part of this application by inclusion. In di-, and tri-valence forms, nickel and cobalt can form poorly soluble hydroxides and oxides. Accordingly, they can also be retained and recuperated in biological processes, including aerobic and some anoxic steps.
The method further provides at least one recuperable alkalinity control specie. Such specie can be selected from calcium, zinc, aluminum, iron, nickel, cobalt, cesium, and combinations thereof. Effects of such species are described in the co-pending U.S. application Ser. No. 08/982,030, now U.S. Pat. No. 5,798,043, which is made a part of the present application by inclusion.
The present method can be conducted in a multi step system. The sequence of the said steps is selected from a group comprising sequential treatment steps, parallel treatment steps, parallel-sequential treatment steps, treatment steps in a racetrack arrangement, treatment steps with recycling the said wastewater and the said biomass among and between the said steps, and combinations thereof. The operation mode of at least one step in the said system is selected from a group comprising continuous operation, batch operation, continuous operation with flow equalization, and combinations thereof. The said batch operation steps are selected from the group comprising aerobic treatment, nitrification treatment, anoxic treatment, denitrification treatment, biomass oxidation treatment, facultative anaerobic treatment. The said batch operation steps are selected from the group comprising filling step, filling-stripping step, reacting step, reacting-stripping step, settling step, decanting step, and combinations thereof.
In continuous and batch modes of the present method, the said wastewater can be repeatedly treated in at least two functional zones for conducting the steps selected from the group comprising oxygen enriched treatment, aerobic treatment, nitrification treatment, anoxic treatment, denitrification treatment, facultative anaerobic treatment, sulfate reduction, carbonate reduction, sludge conditioning, biomass oxidation treatment, and combinations thereof.
The said biomass in the said system is composed of microorganisms selected from the group comprising obligate aerobic, facultative aerobic, nitrifying, denitrifying, ferrous iron oxidizing, ferric iron reducing, anoxic, facultative anaerobic, sulfate reducing, methanogenic, obligate anaerobic, and mixtures thereof. Further, the present method can provide at least one step of anaerobic sludge conditioning to produce biomass enriched with methanogens, and at least one step of feeding at least a portion of the said conditioned sludge with enhanced content of methanogens in at least one step of the said system.
When wastewater contains nitrogen oxy ions, nitrites and nitrates, the present method can be conducted in a system comprising at least one denitrification step, at least one step of the said biomass oxidation (or other reduction step), a step of treating the said biomass repeatedly in the said denitrification and biomass oxidation steps, and a step of charging in the said system at least one recuperable abiotic specie with a variable oxidation state.
The present process can be carried out in an apparatus comprising at least one biological wastewater treatment zone with aerobic conditions, and/or at least one denitrification zone with the use of recuperable oxidation-reduction mediator species in a lower oxidation state, and at least one zone of oxidizing the said biomass with the use of recuperable oxidation-reduction mediator species in a higher oxidation state. Transferring means for the repeated treatment of the said biomass in the said biological treatment zones can also be provided. At least two of the said biological treatment zones and the sludge oxidation zone can be combined in a single reservoir. Moreover, at least two of the said zones can be combined in the same space in a single reservoir.
The new apparatus can be a multi zone system. The zone connection in the said multi zone system is selected from a group comprising sequential treatment zones, parallel treatment zones, parallel-sequential treatment zones, treatment zones in a racetrack arrangement, treatment zones with recycling the said wastewater and the said biomass among and between the said zones, and combinations thereof. An apparatus can further be provided with a zone of anaerobic treatment of the said wastewater.
DRAWINGS
FIG. 1 is a simplified pH-ORP diagram for iron.
FIG. 2 is a simplified pH-ORP diagram for cobalt.
FIG. 3 is a flowchart of a denitrification process with biomass oxidation in a sideline zone with reducing conditions.
FIG. 4 is a flowchart of a process of FIG. 1 with an added aerobic process step following the denitrification stage.
FIG. 5 is a flowchart of a process of FIG. 2 with an added aerobic process step preceding the denitrification step.
FIG. 6 is a flow chart of a portion of a treatment system with two sequential aerobic-denitrification zones and a single dedicated biomass oxidation zone.
FIG. 7 is a flowchart of a denitrification process with a dedicated biomass oxidation zone in the sludge recycle line.
FIG. 8 is a layout of a race track system with an aerobic, denitrification and biomass oxidation zones.
FIG. 9 is a cross section of a denitrification-aeration-biomass oxidation unit.
FIG. 10 is a modified Biolac system with added denitrification-biomass oxidation zones.
DETAILED DESCRIPTION OF INVENTION
FIG. 3 is a flowchart of a denitrification process with biomass oxidation in a sideline zone with reducing conditions. This embodiment is operated as follows. The system is charged with a recuperable oxidation-reduction mediator species having variable oxidation state, for example, with iron salt, whereby iron can change between the higher valence ions (trivalent ferric ions) and lower valence ions (divalent ferrous ions). Wastewater loaded with organics and nitrites and/or nitrates is fed via line 1 in the denitrification zone 2. In this zone, organics are biologically oxidized to carbon dioxide and water and a new biomass is formed. Simultaneously, nitrites and/or nitrates are partially reduced to molecular nitrogen and nitrous and nitric oxides (gaseous nitrogen forms), and the remaining nitrites and nitrates oxidize ferrous ions to ferric with the conversion to gaseous nitrogen forms. A portion of the mixed liquor from zone 2 is directed via line 3 to the final sludge separator 4 (a clarifier or other means), the clarified treated wastewater is evacuated via line 5 and the separated sludge is recycled to zone 2 via line 9. The other portion of the mixed liquor is directed via line 7 in the biomass oxidation zone 6 and returned back in zone 2 via line 8. In zone 6, ferric ions oxidize biomass and revert to ferrous ions; the latter are recycled in zone 2 to be used in denitrification process. Biomass oxidation causes a dramatic excess sludge reduction. Iron ions form insoluble phosphates which particles become enmeshed in the sludge and are removed from the system with the excess sludge. At pH range of biological treatment, virtually insoluble ferric hydroxide and sparingly soluble ferrous hydroxide are formed. Accordingly, iron ions charged in the system circulate between zones 2 and 6 and the sludge separator 4.
The advantages of this process over the prior art are as follows. Nitrites and nitrates are removed by oxidizing ferrous ions to ferric. In prior art, methanol or other purchased organics are used instead. Moreover, ferric ions are further used to oxidize biomass thus reducing the excess sludge. This is an unexpected benefit of the present invention. Because iron ions are used for denitrification and biomass oxidation, there is always an excess iron insuring complete phosphorus removal. In contrast to conventional phosphorus removal methods with metal salt additions, losses of the charged iron are very low. Accordingly, iron ions and other similar species are called herein the recuperable abiotic species. The iron losses are due to binding phosphorus, and due to some loss of iron hydroxides with a small quantity of waste sludge. However, the iron lost with sludge is a coagulant that would be added to the sludge later in the sludge treatment processes. Therefore, all charged iron is beneficially used in the system. Moreover, sludge oxidized in the present process is well mineralized and easy to dewater. It will not need stabilization in a dedicated sludge treatment process. Optionally, the waste sludge can by hydrolyzed by using chemical, thermal, or anaerobic biological hydrolysis, and the said recuperable oxidation-reduction mediator species can be almost completely recovered for the use in the present process. The remaining residue is largely an insoluble mineral material that can be used, for example, as a fill in construction projects.
FIG. 4 is a flowchart of a process of FIG. 1 with an added aerobic process step 10 following the denitrification stage 2. A recycle line 15 can also be provided. This embodiment can be used for removal of the influent nitrogen in forms different from nitrites and nitrates. For example, wastewater influent can include organic and/or ammonia nitrogen. In this embodiment, nitrogen is converted into nitrates and nitrites in the aerobic zone 10 and recycled in the denitrification zone 2 via line 15. The rest of the operations are the same as previously described and will not be repeated. Due to oxidation to ferric ions, loss of iron with the effluent will be virtually eliminated.
FIG. 5 is a flowchart of a process of FIG. 4 with an added aerobic process step 12 preceding the denitrification step 2. This figure also shows a mixed liquor recycle line 15 between zones 2 and 12, a mixed liquor recycle line 16 between zones 19 and 6, and a line 14 for feeding a portion of the influent to zone 6. In zone 12, organics are converted to new biomass, carbon dioxide, and water, and nitrogen is largely converted into nitrites and nitrates. Zones 2 and 6 are operated as previously described. The aerobic zone 10 serves as a zone of thorough organics removal and iron oxidation. Additional nitrification can also occur in this zone. Recycle line 15 is optional and should preferably be used when treating wastewater with high nitrogen content. Recycling denitrified flow to zone 12 reduces concentration of nitrites and nitrates and pH swings in the system. Recycle line 16 can be used to deliver ferric ions directly to the biomass oxidation zone 6 to oxidize more biomass. Additionally, recycles via lines 15 and 16 equalize the influent organics and nitrogen concentrations. Line 14 provides direct feed of organics with a portion of the influent to the biomass oxidation zone 6 for consumption of excess ferric ions in the system.
FIG. 6 is a flow chart of a portion of a treatment system with two sequential aerobic-denitrification zones 12 and 2a and 17 and 2b and a single dedicated biomass oxidation zone 6. Such arrangement can be combined with additional aerobic and sludge separation zones and recycle lines as previously described. This arrangement can be used for thorough nitrogen removal. The single biomass oxidation zone in this embodiment is one more illustration of possible modifications that can be easily designed by a skillful in art based on the present teaching.
FIG. 7 is a flowchart of a denitrification process with the dedicated biomass oxidation zone in the sludge recycle line. In this embodiment, the wastewater influent is fed via line 1 in the aerobic zone 12 where organics are converted to new biomass, carbon dioxide and water, and nitrogen species are oxidized to nitrites and nitrates. From zone 12, the mixed liquor is directed via line 13 into zone 2 for denitrification with ferrous ions. Further, mixed liquor goes via line 3 to an aerobic zone 10 for thorough removal of organics and oxidation of ferrous ions to ferric, which form ferric hydroxide. A mixed liquor carrying biomass and flocculated ferric hydroxide enter the sludge separator 4. Upon separation, the clarified treated wastewater is discharged via line 5. The separated sludge comprising biomass, ferric hydroxide, and the accumulated inert constituents is evacuated via line 9. It is further directed in part to the aerobic zone 12, while the balance of the sludge is fed through line 19 to the biomass oxidation zone 20 and further via line 21 to zone 2. Optionally, a portion of sludge from zone 20 can be fed via line 22 in zone 12. Biomass is partially oxidized in zone 20 by ferric ions becoming ferrous ions.
FIG. 8 is a layout of a race track system with an aerobic, denitrification and sludge oxidation zones. This embodiment comprises an influent line 1, a circular aerobic zone 12 embracing a circular denitrification zone 2, the central biomass oxidation zone 6, and the line 3 leading to the sludge separator. The sludge separator and sludge return means are not shown. Brush aerators 23 are aerating and propelling mixed liquor in zone 12. Propeller mixers 24 and 25 propel and mix mixed liquor in zones 2 and 6 respectively. Zones 12, 2, and 6 communicate hydraulically with the use of gates 13, 7 and 8. This layout corresponds to the flow chart shown in FIG. 4 and is operated as previously described. Other modification of racetrack layouts and equipment can be used as known to skillful in art at the time of design. Present teachings are sufficient for designing the process variants not shown in this specification.
FIG. 9 is a cross section of a denitrification-aeration-biomass oxidation unit. This system comprises a reservoir 28 accommodating functional zones 2, 6 and 10 as described in FIG. 4. Accordingly, the system is operated as previously described. Only specific features related to this particular layout are discussed. In this system, zone 2 is exposed above zone 6 and the sludge comprising the biomass and iron hydroxides is densified in zone 6. This reduces the volume of the biomass oxidation zone 6. The sludge can be lifted from zone 6 to zone 2 via standpipe 7, which can be fitted with an airlift, a pump, a jet pump, or other lifting means. Aerators 26 and clarifiers 4 are shown in zone 10. This embodiment does not have well defined borders separating zones 2, 6, and 10, and many lines shown in FIG. 4 for connecting these zones are absent. Other modifications of combined layouts and equipment can be used as known to skillful in art at the time of design. Present teachings are sufficient for designing the process variants not shown in this specification.
FIG. 10 is a modified Biolac system with added denitrification-biomass oxidation zones. Biolac is described in U.S. Pat. Nos. 4,287,062, 4,797,212, and 5,472,611. This system comprises a reservoir 28 accommodating functional zones 12, 2, 6, and 10 as described in FIG. 5. Accordingly, the system is operated as previously described. Only specific features related to this particular layout are discussed. In this system, zone 2 is exposed above zone 6 and the sludge comprising the biomass and iron hydroxides is densified in zone 6. This reduces the volume of the biomass oxidation zone 6. The sludge can be lifted from zone 6 to zone 2 via standpipe 7, which can be fitted with an airlift, a pump, a jet pump, or other lifting means. Floating aerators 26 are shown in aerobic zones 12 and 10. Floating clarifiers (not shown) can also be installed within the reservoir 28. In contrast to other described systems, this embodiment has floating and moving aerators 26 and a floating and moving sludge transfer means 7. Aerators 26 and the sludge transfer means 7 are connected to and suspended from a floating air pipe 27, which is connected to an air conduit 29. Structural support for the floating assembly including elements 7, 26, and 27 is provided by a cable 30 and anchors 31. Optional curtains 32 can be provided for a better separation of the denitrification zone 2 from the aerobic zones 12 and 10. This embodiment also does not have well defined borders separating zones 2, 6, and 10, and many lines shown in FIG. 3 for connecting these zones are absent. Other modifications of combined layouts and equipment can be used as known to skillful in art at the time of design. For example, zones 2 and 6 can be accommodated over a flat bottom using partitions, walls of the reservoir 28 can be vertical, and a conventional clarifier for sludge separation can be installed within or beyond the reservoir 28.
Addition of calcium, for example lime, to the present system is also beneficial. In aerobic zones, such as zones 10 and 12, carbon dioxide is stripped and insoluble calcium carbonate is formed. This insoluble compound is retained in the system and transferred in the denitrification zones 2 and further in biomass oxidation zones 6. In zones 2 and 6, carbon dioxide is formed and not well stripped and some volatile fatty acids can also be formed, thus producing acidification of the media in these zones. Under such conditions calcium carbonate will convert to calcium bicarbonate thus buffering pH. It is possible to maintain near optimal pH values in all zones in this system for nitrification, denitrification, and iron oxidation. Addition of small quantities of catalysts, for example, manganese or copper salts, further increases the rate and efficiency of iron oxidation in the system. Powdered (pulverized) activated carbon (PAC), and or powdered or fine-crushed coal can also be used to increase the rate and efficiency of oxidation-reduction processes in the present system. Similarly to iron and calcium, losses of PAC are very small. Therefore, it can be charged once and small losses can be periodically replenished.
The pool of recuperable oxidation-reduction species in biological treatment systems with fluctuating flows and concentrations helps to smooth the dynamic variations in the output parameters (effluent quality) and in demands for aeration and other operating conditions. For example, during a low organics loading rate in a biological treatment of BOD (COD) with or without nutrients removal the oxidized forms of the recuperable oxidation-reduction species accumulate in the system. During the period of greater than average loading rate, the previously accumulated oxidized species are reduced thus minimizing the peak oxygen demand. Respectively, the aeration system does not need to be designed for the maximum BOD and ammonia nitrogen loading rates. It can correspond to a somewhat prudently greater than the average loading rate. Such a dynamic behavior of the present system is a significant unexpected benefit for the cost reduction and simplicity of operation.
FIGS. 1 and 2 define significant properties of recuperable oxidation-reduction mediator species. These figures also clearly show that the boundaries between oxidation and reduction domains are different for the selected species. Moreover, some species can divide the total oxidation-reduction domain of biological processes into more than two oxidation and reduction domains. Accordingly, definition of oxidizing and reducing biological steps should be coordinated with the properties of selected recuperable oxidation-reduction mediator specie. Biological processes can be graded from oxidizing to reducing as follows: high purity oxygen systems, air aerated systems including nitrification, denitrification systems, ferric iron reduction systems, sulfate reduction systems, carbonate reduction (methanation) systems. Corresponding primary oxidizers, or primary electron acceptors, are oxygen, oxygen of air, nitrites and nitrates, ferric iron, sulfates, and carbonates. Some organics, particularly, halogenated compounds, can also be oxidizers. Hydrocarbons (admixtures in the wastewater) and biomass (ultimately a product derived from the hydrocarbons) constitute terminal reducing agents, or terminal electron donors. The recuperable oxidation-reduction species are the secondary oxidizing species (electron acceptors) in their oxidation reactions of the terminal reducing agents and they are the secondary reducing agents (electron donors) in their reduction reactions with the primary oxidizers. High purity oxygen systems and carbon dioxide reduction systems are always oxidation and reducing steps in the context of this method. However, all other steps in the oxidation-reduction scale can be either oxidation or reduction steps depending on the position of the boundary line (or lines) in the pH-ORP diagram for the selected recuperable oxidation-reduction mediator specie, or a combination of such species. It is understood that a combination of several recuperable oxidation-reduction mediator species can be used simultaneously. These species can perform as described in this method, and also react with each other as known to skillful in art. For example, nickel and cobalt can cement on zero-valence iron, various oxidation-reduction or other processes known from fundamental sciences and engineering applications can occur. These interactions can produce synergistic beneficial effects in the present method. For example, cementation of a more electropositive specie on the a less electropositive one accelerates the target process rate and efficiency. Accordingly, the present invention meets the objectives: to provide a simple, reliable, efficient and economical system for removal of organics and nutrients with low generation of sludges.
It will therefore be understood by those skilled in the art that particular embodiments of the invention here presented are by way of illustration only, and are meant to be in no way restrictive; therefore numerous changes and modifications may be made, and the full use of equivalents resorted to, without departing from the spirit and the scope of the invention as outlined in the appended claims. | 4y
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BACKGROUND
[0001] The wireless industry is rapidly developing content driven applications for mobile devices to complement traditional voice applications. Content includes music, still and motion video, etc. The goal is to provide mobile device users with a wide variety of services and features.
[0002] Many mobile device users are currently able to download files to their mobile wireless and handheld devices. To accommodate these larger files, the mobile devices now include larger storage capacity. Additional internal storage mechanisms and removable storage devices such as memory sticks or flash memory devices can add a significant amount memory capacity required to handle the larger audio and video files that can be downloaded and executed on a mobile device. A typical MP3 audio file can occupy up to 10 Mb of memory. Video files such as MPEG can take up even more space.
[0003] There are also an increased number of content providers that constantly are adding to their offerings. In many cases user can purchase content files and download them to their mobile devices.
[0004] The download process, however, takes time and battery resources. In some cases the user can lose content if their mobile device loses too much battery power before the download process is completed. This can be annoying and costly especially if the user has been already billed and the purchased content download is terminated prematurely.
[0005] What is needed is a mechanism to help ensure that there is enough battery power remaining to allow a purchased download to complete.
SUMMARY
[0006] The present invention provides a mechanism for a mobile device to estimate the power required to download a desired file from a remote source. The mobile device includes, inter alia, a digital processor, a battery, a battery warning software application executable by the digital processor, and a user interface that can access and manipulate the battery warning software application as well as display data generated by the battery warning software application. The mobile device further provides a communications module coupled with the digital processor for providing a communications link to the remote source such that the desired file to be downloaded can be wirelessly received by the mobile device. In addition, the mobile device also includes a data storage mechanism for storing the desired file to be downloaded from the remote source once it is wirelessly received by the mobile device. However, if the data file to be downloaded is streaming data (audio, video, or both), then the “data file” need not be stored but buffered in memory instead.
[0007] The present invention may also be implemented as a battery warning software application resident in a mobile device and executable by the mobile device. The mobile device includes a display and is able to wirelessly exchange data with a remote source. The battery warning software application includes a download estimation component comprised of computer program code that estimates the power required to download a desired file from the remote source. The battery warning software application further includes a remaining battery time estimation component comprised of computer program code that estimates the remaining power currently available to the mobile device. Also included is a comparison component comprised of computer program code that compares the estimated power required to download a desired file from the remote source to the estimated remaining power currently available to the mobile device. In addition, a user interface component is included comprised of computer program code that displays a warning on the mobile device's display when the estimated power required to download a desired file from the remote source is within a predetermined value to the estimated remaining power currently available to the mobile device. The battery warning software application is also linked with a communications component comprised of computer program code that provides a communications link to the remote source such that the desired file to be downloaded from the remote source can be wirelessly received by the mobile device. The battery warning software further allows a data storage component comprised of computer program code to store the desired file to be downloaded from the remote source in a data storage device once it is wirelessly received by the mobile device.
[0008] The present invention may also be implemented as a method of estimating the power required by a mobile device to download a desired file from a remote source. The method estimates the power needed to download the desired file from the remote source and the remaining power currently available to the mobile device. The method then compares the power needed to download the desired file from the remote source to the remaining power currently available to the mobile device. If the estimated power required to download a desired file from the remote source is within a predetermined value to the estimated remaining power currently available to the mobile device, then the mobile device displays a “Low Battery” warning.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a block diagram illustrating functions and components that comprise the present invention.
[0010] FIG. 2 is a textual sub-menu illustrating a sample list of selectable content files that can be downloaded.
[0011] FIG. 3 is a view of a “Low Battery” warning screen used to inform the user that the mobile device may not be able to complete the download before the battery gets too weak.
[0012] FIG. 4 is a flowchart of logic used to carry out the present invention.
DETAILED DESCRIPTION
[0013] FIG. 1 is a block diagram illustrating functions and components that comprise the present invention. A mobile device 100 includes a battery warning software application 110 that is executable by a digital processor 120 . The battery warning software application is also coupled with a user interface 130 and the power source 140 (battery) of the mobile device 100 . The digital processor 120 is further coupled with a communications module 150 and a storage mechanism 160 . The storage mechanism can be an internal storage device or a removable storage medium such as a memory stick, or both.
[0014] The communications module 150 is enabled to wirelessly communicate with a content provider over a data protocol such as General Packet Radio Service (GPRS) or Enhanced Data for Global Evolution (EDGE). Other data protocols can be implemented without affecting the processes of the present invention.
[0015] The user responds to the output of the battery warning software application 110 via the user interface 130 . The user interface is primarily comprised of the mobile device's display and keypad. Audible alerts can also be part of the user interface.
[0016] When a user successfully downloads a content data file via the communications module 150 , it will be stored within the mobile device or on a removable storage media. This is illustrated as stored data 160 in FIG. 1 .
[0017] FIG. 2 is a textual sub-menu illustrating a sample list of selectable content files that can be downloaded to the user's mobile device 100 . The present invention is described without getting into the particulars of how a content file is purchased and downloaded from a content provider. The present invention is focused on ensuring that the download process will not fail for lack of battery power regardless of the actual download process. Thus, FIG. 2 presents a generic menu listing 210 of selections of audio data files. This example assumes that the mobile user has accessed a content provider's mobile service and has been pushed a list 210 of eligible audio files for download. This list 210 could have been the product of a search query. In this example, the selection “Forever Young.MP3” has been underlined indicating that the user wishes to select and download this file. It is presumed that the user has a subscription with the content provider and will be billed upon initiation of the download.
[0018] FIG. 3 is a view of a “Low Battery” warning screen 310 used to inform the user that the mobile device 100 may not be able to complete the download before the battery gets too weak. This screen will be displayed when the mobile device determines that the battery power that is likely needed to accomplish the download could exceed the remaining battery life of the mobile device in its current state. The user then has the option of aborting the download prior to incurring a download fee. Or, if the user happens to be near a power charging source, he can connect the mobile device to the power charging source before continuing with the download.
[0019] FIG. 4 is a flowchart of logic used to carry out the present invention. The first step shown in FIG. 4 calls for the user to select an item to download 410 . This presupposes that the user's mobile device is capable of performing such a task and that the user has already manipulated the mobile device to present a list similar to the one shown in FIG. 2 . The actual format and presentation of such a list is not patentably relevant to the present invention as it is merely illustrative in nature. Moreover, the type of file to be downloaded and any fee arrangement for such a download are also considered to be tangential to the present invention. The present invention provides a mechanism to determine whether the mobile device's battery contains ample reserves to perform the desired task.
[0020] Once the user has selected a file to download, the mobile device estimates the time (and power) needed to download the selected item 420 . This calculation is an estimation based on several factors including, but not limited to, the size of the file to be downloaded, the current effective bandwidth of the wireless data connection between the mobile device and the host server containing the file to be downloaded, and the current signal quality of the wireless data connection. File size data is typically supplied by the content provider with an item when originally listed. This is a courtesy to the user so that the user can determine if their device has the required memory to receive and store the desired file. The other parameters can be determined by the mobile device itself while monitoring the communications channel it is currently using.
[0021] The mobile device then estimates the time (and power) currently remaining on the mobile device 430 . The MS low battery application running on the mobile device then compares the time/power required to complete the download against the time/power remaining on the mobile device 440 . If the time/power remaining on the mobile device 430 exceeds the estimate for the time/power required to complete the download 420 , then the mobile device will initiate the download 450 without further delay. However, if the time/power remaining on the mobile device 430 is less than the estimate for the time/power required to complete the download 420 , then the mobile device will display a “Low Battery” warning 460 similar to the one shown in FIG. 3 .
[0022] The MS low battery application can set tolerances or thresholds for the comparison. For instance, the MS low battery application may require that the time/power required to complete the download 420 exceed the time/power remaining on the mobile device 430 by a threshold amount before initiating a download. Such tolerances or thresholds can have a default setting but can be overwritten or changed by the user if desired.
[0023] In addition to displaying a “Low Battery” warning 460 , the mobile device will also prompt the user to select a course of action 470 . There are three courses of action shown in FIG. 4 including: aborting the download 480 , connecting the mobile device to a power charger (if readily available) 485 before continuing with the download, or initiating the download despite the “Low Battery” warning 490 .
[0024] The foregoing description has focused on a mobile phone or mobile device and its power consumption when faced with a download scenario. The principles can be readily applied to a portable computer (PC) such as a laptop since a laptop is often operated in a battery powered mode. As such, a mobile device is intended to include a mobile phone, a laptop or notebook computer, a personal digital assistant (PDA), and any other device exhibiting portable mobility that relies on battery power to operate in certain situations.
[0025] Laptops can use a wide variety of data connections to host servers on remote networks. The laptop can connect to a network node via a direct wire connection such as Ethernet, a wireless LAN connection such as WiFi or Bluetooth™, or a mobile wireless connection such as a PCM card running a wireless protocol like those used by mobile devices.
[0026] There are also many instances in which a laptop can be used to download data files for a fee. One particularly common example is a music download via an Internet service such as I-Tunes™.
[0027] In addition, the description (and subsequent claims) have been characterized in terms of a data file that is to be downloaded. Data file can include, but is not limited to, audio files, video files, text files, streaming audio data, streaming video data, or a combination audio/video streaming data.
[0028] Computer program elements of the invention may be embodied in hardware and/or in software (including firmware, resident software, micro-code, etc.). The invention may take the form of a computer program product, which can be embodied by a computer-usable or computer-readable storage medium having computer-usable or computer-readable program instructions, “code” or a “computer program” embodied in the medium for use by or in connection with the instruction execution system. In the context of this document, a computer-usable or computer-readable medium may be any medium that can contain, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The computer-usable or computer-readable medium may be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium such as the Internet. Note that the computer-usable or computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via, for instance, optical scanning of the paper or other medium, then compiled, interpreted, or otherwise processed in a suitable manner. The computer program product and any software and hardware described herein form the various means for carrying out the functions of the invention in the example embodiments.
[0029] Specific embodiments of an invention are disclosed herein. One of ordinary skill in the art will readily recognize that the invention may have other applications in other environments. In fact, many embodiments and implementations are possible. The following claims are in no way intended to limit the scope of the present invention to the specific embodiments described above. In addition, any recitation of “means for” is intended to evoke a means-plus-function reading of an element and a claim, whereas, any elements that do not specifically use the recitation “means for”, are not intended to be read as means-plus-function elements, even if the claim otherwise includes the word “means”. | 4y
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This application is a continuation, of application Ser. No. 07/411,957 filed Sept. 25, 1989, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an attenuatinq element which utilizes a yttrium-iron-garnet (YIG) material, and more particularly to a method of fabricating a plurality of such elements at one time.
2. Description of the Related Art
Frequency selective limiters (FSL) or attenuating devices which utilize a yttrium-iron-garnet (YIG) material have the property of being able to attenuate higher power level signals while simultaneously allowing lower power level signals, separated by only a small frequency offset from the higher level signals, to pass with relatively low loss. YIG-based FSL's are capable of limiting or attenuating across more than an octave bandwidth in the 2-8 GHz range. Higher power level (above-threshold) signals within a selectivity bandwidth will be attenuated without requiring tuning of the FSL. Lower power level (below-threshold) signals separated from the higher power level signals by more than a few spinwave linewidths will pass through the FSL without experiencing any greater loss than if the higher power level signals were not present. For an attenuating device based on YIG, this selectivity bandwidth is on the order of between 20-50 MHz.
A portion of a fully assembled FSL is illustrated in perspective in FIG. 1. Signal carrying conductor 12 is positioned between first and second YIG layers or slabs 14, -6 each having a generally planar configuration. The second YIG slab 16 has an overall length less than the overall length of the first YIG slab 14. As a result, the end portion 18 (one shown) of the signal carrying conductor 12 extends outwardly beyond the transverse edge 20 (one shown) of second YIG slab 16. The YIG slabs 14 and 16 and the signal carrying conductor 12 are supported on a metallized substrate 22 and are surrounded by a ground plane 24. Jumpers (not shown) may be utilized to serially connect a plurality of FSL's. The thickness of each YIG slab 14 and 16 may be varied to make the impedance of the signal carrying conductor 12 compatible with amplifiers and other external circuits (not shown). It has been found that increasing the thickness of the YIG slabs 14 and 16 increases the level of attenuation per unit length of YIG material at a given power level above some threshold power level. The apparatus shown in FIG. 1 is described in greater detail in a copending U.S. patent application entitled "Frequency Selective Limiting Device", Ser. No. 07/169,926, filed Mar. 18, 1988 in the name of Steven N. Stitzer et al. and assigned to Westinghouse Electric Corporation the assignee herein now U.S. Pat. No. 4,845,439 issued July 4, 1989.
The processing technique used thus far for making individual FSL units 10 has consisted of cutting all of the parts of the structure to final size from standard wafers, then processing the individual parts through a series of steps. Individual parts processing is labor intensive and uniformity in the final product is difficult to achieve on a regular basis. In addition, the expense involved in individual parts processing can be considerable.
SUMMARY OF THE INVENTION
The present invention provides a method for assembling a plurality of frequency selective limiting (FSL) units. A generally planar first ferrite member is secured to a metallized surface of a substrate layer. Thereafter a plurality of linear signal carrying conductors are placed on the first ferrite member in spaced relation. A second ferrite member is then bonded to the conductors and the first ferrite member with a nonconductive adhesive to form a multilayer structure. Grooves are cut into the multilayer structure between adjacent conductors. The grooves extend through both ferrite members exposing the metallized surface of the substrate layer. The upper surface and the grooves of the multilayer structure, are metallized in a conformal manner. The sandwich structure is then separated into a plurality of individual FSL units.
In a preferred embodiment, the first and second ferrite members are carried on respective supporting substrates. After each ferrite member is secured or bonded to the overall structure, their respective supporting substrates are ground off.
The metallized surface of the substrate layer and the metallized upper surface of the sandwich structure form an RF shield for containing the RF field lines generated by a signal flowing through the conductor to within the frequency selective limiting unit
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an FSL described in the above-referenced copending application.
FIGS. 2A-2L present in a series of fragmentary side sectional views the sequence of steps for assembling a plurality of frequency selective limiting units;
FIG. 3 illustrates graphically a spin curve representing the thickness of a nonconductive epoxy for a given spin rate.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The theory of operation and the construction of frequency selective limiting (FSL) devices which utilize a yttrium-iron-garnet (YIG) material are described in the following articles, which are incorporated by reference herein: "Frequency Selective Microwave Power Limiting in Thin YIG Films," IEEE Transactions on Magnetics, Vol. MAG-19, No. 5, September 1983, Steven N. Stitzer; "A Multi-Octave Frequency Selective Limiter," 1983 IEEE MTT-S Digest, page 326, Steven N. Stitzer and Harry Goldie; "Non-Linear Microwave Signal-Processing Devices Using Thin Ferromagnetic Films," Circuits Systems Signal Process, Vol. 4, No. 1-2, 1985, page 227, Steven N. Stitzer and Peter R. Emtage.
The present invention comprises a method for fabricating a plurality of YIG-based FSL elements at one time. Referring to FIGS. 2A-2L, only a fragmentary portion of a wafer is shown in cross-section at each major step of the process.
The starting materials for the process (FIG. 2A) are a nonmagnetic substrate 30 and a wafer 32 formed from a nonmagnetic substrate 34 having a layer of ferrite material 36 thereon. In the preferred embodiment, the nonmagnetic substrates 30 and 34 are gadolinium gallium garnet (GGG) wafers that are available commercially. The ferrite material 36 on the wafer 32 is an epitaxially grown yttrium iron garnet (YIG) dielectric film. The GGG wafer 34 provides support for the YIG film 36.
Although the substrates 30 and 34 are illustrated and described herein as being formed from GGG material, other suitable materials may be utilized. However, the material from which substrates 30 and 34 are formed should be selected to have a thermal expansion coefficient (TEC) which approximates that of the YIG film 36. For example, a high nickle alloy (70% Ni, 17% Mo, 7% Cr, 6% Fe), which has substantially the same TEC of the YIG (ΔL/L=10.4×10 -6 /° C.) may be utilized if desired.
In the preferred embodiment, the GGG substrates 30, 34 are each approximately 18 to 22 mils thick and the YIG film 36 is approximately 4 mils thick. The substrates 30 and wafer 32 are metallized as shown in FIG. 2B with gold films 38 and 40 to a thickness of 2 microns
The substrate 30 and wafer 32 are then bonded together by a conductive adhesive 42 with the two metallized surfaces 38 and 40 in confronting relationship as shown in FIG. 2C to form a multilayer structure 44-C. The metallized surfaces 38 and 40 and the conductive adhesive 42 form a lower ground plane 46 for the structure 44-C.
As shown in FIG. 2D the GGG substrate layer 34 is thereafter removed from the YIG layer 36 by a grinding and polishing procedure. The thickness and surface finish of the YIG layer 36 is then established by known lapping and polishing techniques. Preferably the YIG layer 36 should be approximately 3.6 to 4.4 mils.
The adhesive 42 is preferably a conductive epoxy preform sold commercially as Abelfilm ECF550 by Ablestick Labs a subsidiary of National Starch and Chemical Corporation. The preform 42 is normally supplied in the shape of a disc and is heat cured to form the bond. The preform 42 is approximately 5 mils thick and forms a sufficiently strong bond between the substrates 30 and 32 which is resistent to lateral forces such as shimmying associated with the removal of the GGG substrate layer 34 from the YIG layer 36.
In FIG. 2E the upper surface 48 of the YIG layer 36 is metallized by a layer 50. The metallized layer 50 is preferably gold or other suitable material formed to an approximate thickness of 4 microns.
In FIG. 2F metallic signal conductors 52 are formed by removal of selected portions 54 of the film 50 leaving nonconductive gaps 54 between adjacent conductors 52. Known photolithographic techniques common in the microelectronic industry may be used to form the gaps 54 between the conductors 52.
The multilayer structure 44-F (FIG. 2F) is further processed as follows. A wafer 58 comprising a GGG substrate 60 and YIG layer 62 shown in FIG. 2G is bonded in confronting relationship to the multilayer structure 44-G to thereby form the multilayer structure 44-H (FIG. 4H). Initially, a layer of nonconductive paste 56 is deposited on a surface 68 of the YIG layer 62 to provide adhesion between wafer 58 and the multilayer structure 44-G.
In order to provide good magnetic coupling between the conductors 52 and the YIG layer 62 it is important to control the spacing therebetween. Hence, it is important to control the thickness of the nonconducting paste 56 which bonds the ferrite layers 62 and 36. In general, the nonconducting paste 56 must be sufficiently thick so that its upper surface 64 is more or less coplanar with the upper surface 66 of each conductor 52 after wafer 58 is bonded to structure 44-G. Such an arrangement allows for proper bonding of the multilayer structure 44-G to the YIG layer 62. It is important that the paste 56 does not cover the upper surface 66 of the conductors 52. Ideally, any space between the YIG layer 62 and the conductors 52 should be as small as possible in order to provide maximum magnetic field coupling therebetween. Any gap reduces such magnetic coupling and is thus undesirable.
In the preferred embodiment of the invention the nonconductive paste 56 is made from a combination of Epon® 828, (Shell Oil Co.) an epoxy resin and Versamid® 125 (Henkel Corp.) hardener that is thinned with varying proportions of ethylene glycol mono ethylether (Cellosolve®, Union Carbide Corp.) and xylene. The mixture is spun at various speeds to generate thickness data for the material. An exemplary graph of the thickness versus spin rate is shown in FIG. 3 for a nominal mixture. From the graph it is apparent that at a particular spin rate the material will form a film of a given thickness, determined from the curve. For various materials the spin rate and duration to achieve the desired thickness may be empirically determined without difficulty. The process is sufficiently accurate that a separate viscosity determination is not necessary. Numerous curves may be generated for different compositions of paste 56. Once the mixture and desired thickness are known the required spin rate may be taken from the respective spin curve.
During fabrication, the paste 56 is deposited on the surface 68 of the YIG layer 62. The structure is spun at a speed (and duration) determined from the spin curve (FIG. 3) to result in the desired thickness T. The paste 56 thus spreads to the desired thickness as shown in FIG. 2G. For a desired paste thickness T (equal to the thickness of conductors 52) of 4 microns, the spin rate is shown as 4200 rpm.
After the bonding step shown in FIG. 2H, the GGG substrate 60 is removed from the YIG layer 62 by a grinding and polishing procedure similar to that referred to with respect to FIG. 2D. The result is a multilayer structure 44-I illustrated in FIG. 2I.
Referring to FIG. 2J, grooves 74 are formed in the structure 44-J (FIG. 2J). The grooves 74 extend through both YIG layers 62 and 36 and the metallized layer 40 immediately below the first YIG layer 36 to expose the conductive epoxy 42. Each of the signal carrying conductors 52 is thus physically separated from an adjacent conductor 52 as illustrated in FIG. 2J. The upper surfaces 76 of the structure 44-J including the grooves 74 are coated with a conformal layer of metal 78 thereby forming the structure 44-K illustrated in FIG. 2K. The metallized layer 78 is in electrical contact with the conductive epoxy layer 42 to thereby surround each conductor 52 with a ground plane. The structure 44-K is thereafter diced in order to produce individual FSL units 82 as illustrated in FIG. 2L. Ledges 83, formed on the FSL units 82, aid in making electrical contact. Each of the individual FSL units 82 is relatively uniform in physical and electrical characteristics. With the preferred design dimensions, the above batch sequence can produce 19 individual FSL elements from a single standard 3 inch wafer.
Although the invention has been described in terms of what are at present believed to be its preferred embodiments, it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention. It is therefore intended that the appended claims cover such changes. | 4y
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RELATED APPLICATIONS
[0001] The present application is a continuation of U.S. patent application Ser. No. 12/234,441, filed Sep. 19, 2008, which is a continuation of U.S. patent application Ser. No. 10/974,392, filed Oct. 26, 2004, entitled, “Reactive Replenishable Device Management,” now U.S. Pat. No. 7,444,192, both commonly assigned herewith.
[0002] The present application is also related to co-pending U.S. patent application Ser. No. 10/974,335 filed Oct. 26, 2004 in the name of inventors Blake Dickinson, Lisa Lei Horluchi, and Nathaniel Jordan Ramer, entitled “Dynamic Replenisher Management”, commonly assigned herewith.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The present invention relates to the field of computer science. More particularly, the present invention relates to reactive replenishable device management.
[0005] 2. Description of the Related Art
[0006] Systems for monitoring numerous replenishable device parameters are known in the art. Such systems typically collect battery pack information, recharger information, or both, and make the information available for viewing by an operator. While such systems typically provide visibility with respect to parameters of a particular charger or replenishable device, acting upon these parameters is typically left to operator. Furthermore, operators responsible for multiple devices must scrutinize similar information for several devices in order to determine optimal replenishable device asset allocation. Thus the burden on the operator increases as the number of replenishable device assets increases.
[0007] Accordingly, a need exists in the art for a solution that provides relatively integrated replenishable device management. A further need exists for such a solution that is relatively automated. Yet a further need exists for such a solution that provides relatively efficient replenishable device asset resource allocation.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more embodiments of the present invention and, together with the detailed description, serve to explain the principles and implementations of the invention. In the drawings:
[0009] FIG. 1 is a block diagram of a computer system suitable for implementing aspects of the present invention.
[0010] FIG. 2 is a block diagram that illustrates a system for reactive control of one or more devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention.
[0011] FIG. 3 is a block diagram that illustrates a system for reactive control of one or more networked devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention.
[0012] FIG. 3A is a block diagram that illustrates an apparatus for reactive control of one or more devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention.
[0013] FIG. 4 is a high level data flow diagram that illustrates dynamic control of one or more devices based at least in part on device measurement data collected from the one or more devices in accordance with one embodiment of the present invention.
[0014] FIG. 4A is a flow diagram that illustrates a method for reactive control of one or more devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention.
[0015] FIG. 4B is a flow diagram that illustrates a method for optimized management of a fleet of replenishable devices and devices associated with the replenishable devices, in accordance with one embodiment of the present invention.
[0016] FIG. 5 is a high level block diagram that illustrates a system for automatic control of one or more devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention.
[0017] FIG. 6 is a high level control flow diagram that illustrates automatic control of one or more devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention.
[0018] FIG. 7 is a data flow diagram that illustrates automatic control of one or more chargers based at least in part on device measurement data obtained from one or more batteries in accordance with one embodiment of the present invention.
[0019] FIG. 8 is a data flow diagram that illustrates automatic control of one or more vehicles based at least in part on device measurement data obtained from the one or more vehicles and from one or more batteries associated with the one or more vehicles in accordance with one embodiment of the present invention.
[0020] FIG. 9 is a high level block diagram that illustrates a system for issuing one or more management recommendations based at least in part on device measurement data obtained from one or more devices in accordance with one embodiment of the present invention.
[0021] FIG. 10 is a high level control flow diagram that illustrates issuing one or more management recommendations based at least in part on device measurement data obtained from one or more devices in accordance with one embodiment of the present invention.
[0022] FIG. 11 is a low level data flow diagram that illustrates issuing one or more management recommendations based at least in part on device measurement data obtained from one or more vehicles and from one or more batteries associated with the one or more vehicles in accordance with one embodiment of the present invention.
[0023] FIG. 12 is a high level block diagram that illustrates a system for issuing one or more user alerts based at least in part on device measurement data obtained from one or more devices in accordance with one embodiment of the present invention.
[0024] FIG. 13 is a high level control flow diagram that illustrates issuing one or more user alerts based at least in part on device measurement data obtained from one or more devices in accordance with one embodiment of the present invention.
[0025] FIG. 14 is a low level data flow diagram that illustrates issuing one or more user alerts based at least in part on device measurement data obtained from one or more vehicles and from one or more batteries associated with the one or more vehicles in accordance with one embodiment of the present invention.
[0026] FIG. 15 is a block diagram that illustrates dynamic control of one or more chargers based at least in part on device measurement data collected from the one or more chargers and one or more vehicles associated with the one or more chargers in accordance with one embodiment of the present invention.
[0027] FIG. 16 is a block diagram that illustrates dynamic control of one or more chargers and one or more vehicles associated with the one or more chargers based at least in part on device measurement data collected from the one or more chargers and the one or more vehicles in accordance with one embodiment of the present invention.
[0028] FIG. 17 is a block diagram that illustrates dynamic control of one or more chargers based at least in part on device measurement data collected from the one or more chargers an in accordance with one embodiment of the present invention.
[0029] FIG. 18 is a flow diagram that illustrates a method for battery fault management in accordance with one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Embodiments of the present invention are described herein in the context of reactive replenishable device management. Those of ordinary skill in the art will realize that the following detailed description of the present invention is illustrative only and is not intended to be in any way limiting. Other embodiments of the present invention will readily suggest themselves to such skilled persons having the benefit of this disclosure. Reference will now be made in detail to implementations of the present invention as illustrated in the accompanying drawings. The same reference indicators will be used throughout the drawings and the following detailed description to refer to the same or like parts.
[0031] In the interest of clarity, not all of the routine features of the implementations described herein are shown and described. It will, of course, be appreciated that in the development of any such actual implementation, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with application- and business-related constraints, and that these specific goals will vary from one implementation to another and from one developer to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would nevertheless be a routine undertaking of engineering for those of ordinary skill in the art having the benefit of this disclosure.
[0032] In accordance with one embodiment of the present invention, the components, process steps, and/or data structures may be implemented using various types of operating systems (OS), computing platforms, firmware, computer programs, computer languages, and/or general-purpose machines. The method can be run as a programmed process running on processing circuitry.
[0033] The processing circuitry can take the form of numerous combinations of processors and operating systems, or a stand-alone device. The process can be implemented as instructions executed by such hardware, hardware alone, or any combination thereof. The software may be stored on a program storage device readable by a machine. In addition, those of ordinary skill in the art will recognize that devices of a less general purpose nature, such as hardwired devices, field programmable logic devices (FPLDs), including field programmable gate arrays (FPGAs) and complex programmable logic devices (CPLDs), application specific integrated circuits (ASICs), or the like, may also be used without departing from the scope and spirit of the inventive concepts disclosed herein.
[0034] In accordance with one embodiment of the present invention, the method may be implemented on a data processing computer such as a personal computer, workstation computer, mainframe computer, or high performance server running an OS such as Solaris® available from Sun Microsystems, Inc. of Santa Clara, Calif., Microsoft® Windows® XP and Windows® 2000, available from Microsoft Corporation of Redmond, Wash., or various versions of the Unix operating system such as Linux available from a number of vendors. The method may also be implemented on a multiple-processor system, or in a computing environment including various peripherals such as input devices, output devices, displays, pointing devices, memories, storage devices, media interfaces for transferring data to and from the processor(s), and the like. In addition, such a computer system or computing environment may be networked locally, or over the Internet.
[0035] In the context of the present invention, the term “network” comprises local area networks, wide area networks, the Internet, cable television systems, telephone systems, wireless telecommunications systems, fiber optic networks, ATM networks, frame relay networks, satellite communications systems, and the like. Such networks are well known in the art and consequently are not further described here.
[0036] In the context of the present invention, the term “identifier” describes one or more numbers, characters, symbols, or the like. More generally, an “identifier” describes any entity that can be represented by one or more bits.
[0037] In the context of the present invention, the term “identification data” describes one or more time-invariant attributes of a device. By way of example, identification data comprises an identifier of the device, the size of the device, the capacity of the device, the manufacturer of the device, the maintenance schedule of the device, the warranty schedule of the device, and the like.
[0038] In the context of the present invention, the term “historical data” describes one or more time-variant attributes of a device. Exemplary historical data are shown in Table 1, below.
[0000]
TABLE 1
Historical Data
Date Battery Monitor Identification (BMID) Was Initialized
Days in Operation
Total Charge Abs
Total Charge kilowatt-hours
Total Discharge Ahs
Total Discharge kilowatt-hours
Total Fast Charge Time
# of Fast Charge Events
Total Full Charge Time
Number of Complete Full Charge Events
Total Equalization Charge Time
Number of Complete Equalization Charge Events
Total External Charge Time
Total Run Time
Total Key On Time
Total Key Off Time
Maximum Battery Temperature T 1
Number of Times the Battery Exceeds Temperature T 1
Minimum Battery Temperature T 2
Number of Times the Battery Temperature falls below T 2
Average Battery Temperature
Minimum Battery Voltage V 1
Number of Times the Battery Voltage Falls Below V 1
Maximum Battery Voltage V 2
Number of Times the Battery State-Of-Charge Falls Below 20%
Number of Low Water Events
Last Equalization Start Date
Last Equalization Start Time
Last Equalization End Date
Last Equalization End Time
Last Equalization Ahs
Last Equalization kilowatt-hours
Last Equalization Term Code
Last Equalization Start Temperature
Last Equalization Start Voltage
Last Equalization Start Current
Last Equalization End Temperature
Last Equalization End State-Of-Charge
Last Equalization End Voltage
Last Equalization End Current
Maximum Days Between Equalizations
Maximum Ahs Between Equalizations
Days Since Last Complete Equalization
Ahs Since Last Complete Equalization
[0039] In the context of the present invention, the term “real-time data” describes a single sample of one or more time-variant attributes of a device. Real-time data comprises real-time descriptive data and real-time performance data. Exemplary real-time data are shown in Table 2, below. The real-time data in Table 2 is illustrative and is not intended to be an exhaustive list. Those of ordinary skill in the art will recognize that other real-time data may be used.
[0000]
TABLE 2
Real-Time Data
Charge Ahs
Discharge Ahs
Charge Kilowatt-hours
Discharge Kilowatt-hours
Fast Charge Time
Full Charge Time
Equalization Charge Time
Key On Time
Key Off Time
Run Time
Full Charge Complete
Equalization Complete
Minimum Battery State-Of-Charge
Maximum Battery State-Of-Charge
Average Battery State-Of-Charge
Minimum Battery Temperature T 2
Maximum Battery Temperature T 1
Average Battery Temperature
Minimum Battery Voltage V 1
Maximum Battery Discharge Current
Low Water Event
Fault Code(s)
[0040] FIG. 1 depicts a block diagram of a computer system 100 suitable for implementing aspects of the present invention. As shown in FIG. 1 , computer system 100 includes a bus 102 which interconnects major subsystems such as a central processor 104 , a system memory 106 (typically RAM), an input/output (I/O controller 108 , an external device such as a display screen 110 via display adapter 112 , serial ports 114 and 116 , a keyboard 118 , a fixed disk drive 120 , a floppy disk drive 122 operative to receive a floppy disk 124 , and a CD-ROM player 126 operative to receive a CD-ROM 128 . Many other devices can be connected, such as a pointing device 130 (e.g., a mouse) connected via serial port 114 and a modem 132 connected via serial port 116 . Modem 132 may provide a direct connection to a remote server via a telephone link or to the Internet via a POP (point of presence). Alternatively, a network interface adapter 134 may be used to interface to a local or wide area network using any network interface system known to those skilled in the art (e.g., Ethernet, xDSL, AppleTalk™).
[0041] Many other devices or subsystems (not shown) may be connected in a similar manner. Also, it is not necessary for all of the devices shown in FIG. 1 to be present to practice the present invention, as discussed below. Furthermore, the devices and subsystems may be interconnected in different ways from that shown in FIG. 1 . The operation of a computer system such as that shown in FIG. 1 is readily known in the art and is not discussed in detail in this application, so as not to overcomplicate the present discussion. Code to implement the present invention may be operably disposed in system memory 106 or stored on storage media such as fixed disk 120 , floppy disk 124 , or CD-ROM 128 .
[0042] FIGS. 2 , 3 , and 3 A illustrate systems for reactive control of one or more devices based at least in part on device measurement data obtained from the one or more devices in accordance with embodiments of the present invention. FIG. 2 illustrates the one or more devices operatively coupled via a dedicated communication means to a remote device manager adapted to control the one or more devices. FIG. 3 illustrates the one or more devices and the remote device manager operatively coupled via a network. FIG. 3A illustrates the device manager as part of the one or more devices.
[0043] Turning now to FIG. 2 , a block diagram that illustrates a system for reactive control of one or more devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention is presented. As shown in FIG. 2 , one or more devices 206 comprise a local device controller 240 adapted to control the one or more devices 206 based at least in part on one or more commands from manual control means 238 , or automatic controller 228 . Battery 200 and vehicle 204 are exemplary devices represented by one or more devices 206 . Remote device manager 202 may receive input via manual input means 252 . The type of input received via manual input means 252 may vary depending at least in part on the particular device or devices being managed. Exemplary manual inputs are listed below in Table 3. The manual input data in Table 3 is illustrative and is not intended to be an exhaustive list. Those of ordinary skill in the art will recognize that other manual input data may be used. Manual input means 252 comprises an input device, such as alphanumeric keyboard 118 , numeric keyboard 118 , joystick 116 , roller 114 , directional navigation pad 126 , or display screen 110 of FIG. 1 . Those of ordinary skill in the art will recognize that other input devices may be used.
[0000]
TABLE 3
Manual Inputs
Utility Schedule
Vehicle Pricing
Replenishable Device Pricing
Vehicle Purchase Profile
Replenishable Device Purchase Profile
Maintenance Schedule
Dealer/Distributor Contact Information
Plant Operation Schedule
Driver Associated with a Particular Vehicle
Vehicle Type of a Particular Vehicle
Vehicle Location
Charger Associated with a Particular Vehicle
Vehicle Periodic Maintenance Log/Status
Local Daylight Savings Time
Rechargeable Device Manufacture Date
Vehicle Manufacture Date
Driver Complaints for a Particular Vehicle
Operator Schedule
Utility Power Purchase Agreement(s)
[0044] According to one embodiment, the one or more devices 206 comprise one or more replenishers and one or more replenishable devices. The one or more replenishers may comprise one or more refuelers and the one or more replenishable devices may comprise one or more refuelable devices. By way of example, the one or more refuelable devices may comprise a fuel cell. According to another embodiment, the one or more devices may comprise one or more replenishers and one or more rechargeable devices. According to one embodiment, the one or more replenishers may comprise one or more chargers and the one or more replenishable devices may comprise one or more batteries. According to another embodiment, the one or more chargers may comprise battery chargers and the one or more batteries may comprise one or more replaceable battery packs. According to another embodiment, the one or more devices 206 may further comprise an electric vehicle powered by the one or more replaceable battery packs. According to another embodiment, the one or more devices 206 may further comprise a vehicle powered by one or more replaceable or refuelable fuel cells. The vehicle may be any vehicle that is powered at least in part by a replenishable device. By way of example, the vehicle may comprise an electrically- or fuel cell-powered fork lift, automobile, truck, motorcycle, moped, scooter, airplane, locomotive, submersible vessel, boat, spacecraft, automated guided vehicle (AGV), and automated unguided vehicle (AUGV).
[0045] According to embodiments of the present invention, the replaceable battery packs are based on one or more of the following battery technologies: lead acid, nickel cadmium, nickel metal hydride, nickel zinc, nickel iron, silver zinc, nickel hydrogen, lithium ion, lithium polymer, lithium/iron sulfide, zinc air, zinc bromine, sodium sulfur, regenerative fuel cell, and ultracapacitor. The battery technologies listed are for the purpose of illustration and are not intended to be limiting in any way. Those of ordinary skill in the art will recognize that replaceable battery packs based on other battery technologies may be used.
[0046] According to another embodiment of the present invention, the one or more devices 206 comprises a vehicle powered by the one or more replenishable devices, and the one or more devices 206 further comprises one or more devices that reside in, on, or are otherwise associated with the vehicle. By way of example, the one or more devices may comprise one or more movement sensors, access control devices, shock meters, force meters, and the like.
[0047] According to another embodiment of the present invention, the one or more devices 206 comprises automation equipment.
[0048] According to another embodiment of the present invention, the one or more devices 206 comprises energy management systems, such as distributed generation equipment and the like.
[0049] Still referring to FIG. 2 , remote device manager 202 comprises an aggregator 210 , an analyzer 218 , a determiner 222 , an automatic controller, an advisor 226 , and an alerter 224 . Aggregator 210 is adapted to receive device measurement data 208 from the one or more devices 206 . The received device measurement data 208 comprises one or more of identification data 212 , historical data 214 , and real-time data 216 . Analyzer 218 is adapted to update one or more usage profiles 220 based at least in part on one or more of the identification data 212 , the historical data 214 , and the real-time data 216 .
[0050] The one or more usage profiles 220 comprise information regarding the use of the one or more devices 206 . The one or more usage profiles 220 may be stored in a memory (not shown in FIG. 2 ) associated with the remote device manager 202 .
[0051] Determiner 222 is adapted to invoke one or more of automatic controller 228 , advisor 226 , and alerter 224 based at least in part on the one or more usage profiles 220 . Automatic controller 228 is adapted to automatically control attributes or operations of the one or more devices based at least in part on the device measurement data 208 obtained from the one or more devices 206 by issuing one or more commands 236 to the one or more devices 206 . Automatic controller 228 is described in more detail below with respect to FIGS. 5-8 . Advisor 226 is adapted to issue one or more management recommendations to a user 234 , based at least in part on the device measurement data 208 obtained from the one or more devices. Advisor 226 is described in more detail below with respect to FIGS. 9-11 . Alerter 224 is adapted to issue one or more user alerts to the user 234 , based at least in part on the device measurement data 208 obtained from the one or more devices 206 (either directly from real-time data 216 as shown by reference numeral 250 , or from usage profile 220 ). Alerter 224 is described in more detail below with respect to FIGS. 12-14 . Manual control means 238 may be used by user 234 to control the one or more devices 206 based at least in part on one or more management recommendations received from advisor 226 , or one or more user alerts received from alerter 224 . Manual control means 238 comprises an input device, such as alphanumeric keyboard 118 , numeric keyboard 118 , joystick 116 , roller 114 , directional navigation pad 126 , or display screen 110 of FIG. 1 . Those of ordinary skill in the art will recognize that other input devices may be used.
[0052] In operation, device measurement data 208 is transferred from device 206 to remote device manager 202 . According to one embodiment of the present invention, the transfer is initiated by the one or more devices 206 . According to another embodiment of the present invention, the transfer is initiated by the remote device manager 202 . Aggregator 210 of remote device manager 202 receives the device measurement data 208 . Analyzer 218 updates one or more usage profiles 220 based at least in part on one or more of the identification data 212 , the historical data 214 , and the real-time data 216 . Determiner 222 invokes zero or more of automatic controller 228 , advisor 226 , and alerter 224 based at least in part on the one or more usage profiles 220 . Automatic controller 228 automatically controls attributes or operations of the one or more devices 206 based at least in part on the device measurement data 208 obtained from the one or more devices 206 by issuing one or more commands 236 to the one or more devices 206 . Advisor 226 issues one or more management recommendations to a user 234 , based at least in part on the device measurement data 208 obtained from the one or more devices. Alerter 224 issues one or more user alerts to the user 234 , based at least in part on the device measurement data 208 obtained from the one or more devices 206 .
[0053] According to one embodiment of the present invention, remote device manager 202 comprises one or more of automatic controller 228 , adviser 226 , and alerter 224 .
[0054] Turning now to FIG. 3 , a block diagram that illustrates a system for reactive control of one or more networked devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention is presented. FIG. 3 is similar to FIG. 2 , except that the one or more devices illustrated in FIG. 3 are operatively coupled to a remote device manager via a network. As shown in FIG. 3 , one or more devices 306 comprise a local device controller 340 adapted to control the one or more devices 306 based at least in part on one or more commands from manual control means 338 , or automatic controller 328 . Battery 300 and vehicle 304 are exemplary devices represented by one or more device 306 . The one or more devices 306 are operatively coupled to a remote device manager 302 via a network 344 . At least part of network 344 may reside inside or outside of a physical facility where one or more of the one or more devices 306 and the remote device manager 302 are located. Remote device manager 302 may receive input via manual input means 352 . The type of input received via manual input means 352 may vary depending at least in part on the particular device or devices being managed. Exemplary manual inputs are listed above in Table 3. The manual input data in Table 3 is illustrative and is not intended to be an exhaustive list. Those of ordinary skill in the art will recognize that other manual input data may be used. Manual input means 352 comprises an input device, such as alphanumeric keyboard 118 , numeric keyboard 118 , joystick 116 , roller 114 , directional navigation pad 126 , or display screen 110 of FIG. 1 . Those of ordinary skill in the art will recognize that other input devices maybe used.
[0055] According to one embodiment of the present invention, the one or more devices 306 comprise one or more replenishers and one or more replenishable devices. According to one embodiment of the present invention, the one or more replenishers comprise one or more refuelers and the one or more replenishable devices comprises one or more refuelable devices. By way of example, the one or more refuelable devices may comprise a fuel cell. According to another embodiment of the present invention, the one or more devices comprises one or more replenishers and one or more rechargeable devices. According to one embodiment of the present invention, the one or more replenishers comprises one or more chargers and the one or more replenishable devices comprises one or more batteries. According to another embodiment of the present invention, the one or more chargers comprise battery chargers and the one or more batteries comprise one or more replaceable battery packs. According to another embodiment of the present invention, the one or more devices 306 further comprises an electric vehicle powered by the one or more replaceable battery packs. According to another embodiment of the present invention, the one or more devices 306 further comprises a vehicle powered by one or more replaceable or refuelable fuel cells. The vehicle may be any vehicle that is powered at least in part by a replenishable device. By way of example, the vehicle may comprise an electrically- or fuel cell-powered fork lift, automobile, truck, motorcycle, moped, scooter, airplane, locomotive, submersible vessel, boat, spacecraft, automated guided vehicle (AGV), and automated unguided vehicle (AUGV).
[0056] According to another embodiment of the present invention, the one or more devices 306 comprises a vehicle powered by the one or more replenishable devices, and the one or more devices 306 further comprises one or more devices that reside in, on, or are otherwise associated with the vehicle. By way of example, the one or more devices may comprise one or more movement sensors, access control devices, shock meters, force meters, and the like.
[0057] According to another embodiment of the present invention, the one or more devices 306 comprises automation equipment.
[0058] According to another embodiment of the present invention, the one or more devices 306 comprises energy management systems, such as distributed generation equipment and the like.
[0059] According to embodiments of the present invention, the replaceable battery packs are based on one or more of the following battery technologies: lead acid, nickel cadmium, nickel metal hydride, nickel zinc, nickel iron, silver zinc, nickel hydrogen, lithium ion, lithium polymer, lithium/iron sulfide, zinc air, zinc bromine, sodium sulfur, regenerative fuel cell, and ultracapacitor. The battery technologies listed are for the purpose of illustration and are not intended to be limiting in any way. Those of ordinary skill in the art will recognize that replaceable battery packs based on other battery technologies may be used.
[0060] Still referring to FIG. 3 , remote device manager 302 comprises an aggregator 310 , an analyzer 318 , a determiner 322 , an automatic controller, an advisor 326 , and an alerter 324 . Aggregator 310 is adapted to receive device measurement data 308 from the one or more devices 306 (either directly from real-time data 316 as shown by reference numeral 350 , or from usage profile 320 ). The received device measurement data 308 comprises one or more of identification data 312 , historical data 314 , and real-time data 316 . Analyzer 318 is adapted to updates one or more usage profiles 320 based at least in part on one or more of the identification data 312 , the historical data 314 , and the real-time data 316 .
[0061] The one or more usage profiles 320 comprise information regarding the use of the one or more devices 306 . The one or more usage profiles 320 may be stored in a memory (not shown in FIG. 3 ) associated with the remote device manager 302 .
[0062] Determiner 322 is adapted to invoke one or more of automatic controller 328 , advisor 326 , and alerter 324 based at least in part on the one or more usage profiles 320 . Automatic controller 328 is adapted to automatically control attributes or operations of the one or more devices based at least in part on the device measurement data 308 obtained from the one or more devices 306 by issuing one or more commands 336 to the one or more devices 306 . Automatic controller 328 is described in more detail below with respect to FIGS. 5-8 . Advisor 326 is adapted to issue one or more management recommendations to a user 334 , based at least in part on the device measurement data 308 obtained from the one or more devices. Advisor 326 is described in more detail below with respect to FIGS. 9-11 . Alerter 324 is adapted to issue one or more user alerts to the user 334 , based at least in part on the device measurement data 308 obtained from the one or more devices 306 . Alerter 324 is described in more detail below with respect to FIGS. 12-14 . Manual control means 338 may be used by user 334 to control the one or more devices 306 based at least in part on one or more management recommendations received from advisor 326 , or one or more user alerts received from alerter 324 . Manual control means 338 comprises an input device, such as alphanumeric keyboard 118 , numeric keyboard 118 , joystick 116 , roller 114 , directional navigation pad 126 , or display screen 110 of FIG. 1 . Those of ordinary skill in the art will recognize that other input devices may be used.
[0063] In operation, device measurement data 308 is transferred from device 306 to remote device manager 302 . According to one embodiment of the present invention, the transfer is initiated by the one or more devices 306 . According to another embodiment of the present invention, the transfer is initiated by the remote device manager 302 . Aggregator 310 of remote device manager 302 receives the device measurement data 308 . Analyzer 318 updates one or more usage profiles 320 based at least in part on one or more of the identification data 312 , the historical data 314 , and the real-time data 316 . Determiner 322 invokes zero or more of automatic controller 328 , advisor 326 , and alerter 324 based at least in part on the one or more usage profiles 320 . Automatic controller 328 automatically controls operations or attributes of the one or more devices 306 based at least in part on the device measurement data 308 obtained from the one or more devices 306 by issuing one or more commands 336 to the one or more devices 306 . Advisor 326 issues one or more management recommendations to a user 334 , based at least in part on the device measurement data 308 obtained from the one or more devices. Alerter 324 issues one or more user alerts to the user 334 , based at least in part on the device measurement data 308 obtained from the one or more devices 306 .
[0064] According to one embodiment of the present invention, remote device manager 302 comprises one or more of automatic controller 328 , adviser 326 , and alerter 324 .
[0065] Turning now to FIG. 3A , a block diagram that illustrates an apparatus for reactive control of one or more devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention. Unlike FIGS. 2 and 3 , FIG. 3A shows one or more devices 3 A 06 that comprise a device manager 3 A 02 . Device manager 3 A 02 is configured to operate as discussed previously with respect to reference numeral 202 of FIG. 2 and reference numeral 302 of FIG. 3 , except that the communication of measurement data 3 A 08 to the device manager 3 A 02 and the communication of commands from the device manager 3 A 02 to the local device controller 3 A 40 occurs within the one or more devices 3 A 06 .
[0066] Turning now to FIG. 4 , a high level data flow diagram that illustrates dynamic control of one or more devices based at least in part on device measurement data collected from the one or more devices in accordance with one embodiment of the present invention is presented. As shown in FIG. 4 , device measurement data comprising one or more of identification data 412 , historical performance and descriptive data 414 , and real-time performance and descriptive data 416 are obtained from one or more devices, such as a charger, 452 , a battery 400 , and a vehicle 404 . The device measurement data is analyzed to update one or more usage profiles 420 . According to one embodiment of the present invention, an automatic controller 428 uses the one or more usage profiles 420 to automatically control attributes or operations of the one or more devices ( 400 , 404 , and 452 ). According to another embodiment of the present invention, an advisor 426 uses the one or more usage profiles 420 to issue one or more management recommendations to a user. According to another embodiment of the present invention, an alerter 426 uses the one or more usage profiles to issue one or more user alerts to a user. Having the benefit of a management recommendation from advisor 426 , or an alert from alerter 426 , the user may control the one or more devices ( 400 , 404 , and 452 ) via manual control means 438 .
[0067] Turning now to FIG. 4A , a flow diagram that illustrates a method for reactive control of one or more devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention is presented. FIG. 4A corresponds with FIGS. 2 and 3 . The processes illustrated in FIG. 4A may be implemented in hardware, software, firmware, or a combination thereof. At 4 A 00 , device measurement data from one or more devices is received. The device measurement data comprises one or more of identification data, historical data, and real-time data. At 4 A 05 , one or more usage profiles associated with the device are modified based at least in part on the device measurement data. At 4 A 15 , a determination is made regarding whether automatic control of the one or more devices is enabled. If automatic control is enabled, the automatic control is performed at 4 A 20 . At 4 A 25 , a determination is made regarding whether management recommendations with respect to the one or more devices are enabled. If management recommendations are enabled, the management recommendation processing is performed at 4 A 30 . At 4 A 35 , a determination is made regarding whether user alerts with respect to the one or more devices is enabled. If user alerts is enabled, the user alert processing is performed at 4 A 40 .
[0068] Turning now to FIG. 4B , a flow diagram that illustrates a method for optimized management of a fleet of replenishable devices and devices associated with the replenishable devices, in accordance with one embodiment of the present invention is presented. The processes illustrated in FIG. 4B may be implemented in hardware, software, firmware, or a combination thereof. At 4 B 00 , device usage information for a fleet of replenishable devices and vehicles associated with the replenishable devices is accumulated. Step 4 B 00 may be performed using the process illustrated in FIG. 4A , above. At 4 B 04 , the accumulated device usage information is stored in a global memory. At 4 B 10 , the device usage information accumulated at 4 B 00 and stored at 4 B 05 is used to manage fleet assets. By way of example, if the accumulated device usage information indicates a first vehicle is over utilized and a second vehicle capable of performing substantially the same functions as the first vehicle is underutilized, the first vehicle may be switched with the second vehicle. As a further example, if the accumulated device usage information indicates the fleet as a whole is over utilized, additional devices may be added to the fleet. Likewise, if the accumulated device usage information indicates the fleet as a whole is underutilized, one or more devices may be removed from the fleet.
[0069] FIGS. 5-14 illustrate more detail for an automatic controller, an advisor, and an alerter in accordance with embodiments of the present invention. FIGS. 5-8 illustrate an automatic controller, FIGS. 9-11 illustrate an advisor, and FIGS. 12-14 illustrate an alerter.
[0070] Turning now to FIG. 5 , a high level block diagram that illustrates a system for automatic control of one or more devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention is presented. As shown in FIG. 5 , device 506 comprises a local device controller 540 adapted to control the one or more devices 506 based at least in part on one or more commands from automatic controller 528 . According to one embodiment of the present invention, device 506 and remote device controller 502 are operatively coupled via a dedicated communication means. According to another embodiment of the present invention, device 506 and remote device manager 502 are operatively coupled via a network (not shown in FIG. 5 ). Remote device manager 502 comprises an analyzer 518 and an automatic controller 528 . Analyzer 518 is adapted to update one or more usage profiles 520 based at least in part on one or more of the identification data, the historical data, and the real-time data that comprises the device measurement data 508 .
[0071] The one or more usage profiles 520 comprise information regarding the use of the one or more devices 506 . The one or more usage profiles 520 may be stored in a memory associated with the remote device manager 502 .
[0072] Automatic controller 528 is adapted to automatically control attributes or operations of the one or more devices 506 based at least in part on the device measurement data 508 obtained from the one or more devices 506 by issuing one or more commands 536 to the one or more devices 506 .
[0073] In operation, device measurement data 508 is transferred from device 506 to remote device manager 502 . According to one embodiment of the present invention, the transfer is initiated by the one or more devices 506 . According to another embodiment of the present invention, the transfer is initiated by the remote device manager 502 . Analyzer 518 updates one or more usage profiles 520 based at least in part on one or more of the identification data, the historical data, and the real-time data that comprises the device measurement data 508 . Automatic controller 528 automatically controls attributes or operations of the one or more devices 506 based at least in part on the device measurement data 508 obtained from the one or more devices 506 by issuing one or more commands 536 to the one or more devices 506 .
[0074] Turning now to FIG. 6 , a high level control flow diagram that illustrates automatic control of one or more devices based at least in part on device measurement data obtained from the one or more devices in accordance with one embodiment of the present invention is presented. FIG. 6 corresponds with FIG. 5 and provides more detail for reference numeral 4 A 20 of FIG. 4A . The processes illustrated in FIG. 6 may be implemented in hardware, software, firmware, or a combination thereof. At 600 , a usage profile corresponding to a device is analyzed. At 605 , a determination is made regarding whether the device usage is sub-optimal. If the device usage is sub-optimal, at 610 a command is issued to automatically perform one or more maintenance operations, or to adjust one or more device parameters. Alternatively, the remote device manager stores the command and the one or more devices are adapted to query the remote device manager for the command.
[0075] According to one embodiment of the present invention, process 610 comprises adjusting one or more charge rates. According to another embodiment of the present invention, process 610 comprises adjusting a battery monitor identification (BMID) device to optimize charging rates. According to another embodiment of the present invention, process 610 comprises watering a battery. According to another embodiment of the present invention, process 610 comprises unscheduled battery equalization.
[0076] According to another embodiment of the present invention, process 610 comprises adjusting one or more vehicle performance levels. By way of example, process 610 may comprise adjusting one or more of the vehicle traction acceleration, the vehicle speed, and if the vehicle is a fork lift, the vehicle lift rate and the vehicle lift lockout.
[0077] Turning now to FIG. 7 , a data flow diagram that illustrates automatic control of one or more chargers based at least in part on device measurement data obtained from one or more batteries in accordance with one embodiment of the present invention is presented. As shown in column 702 , the types of data used for automatic control of chargers comprise identification data 704 , real-time descriptive data 706 , real-time performance data 708 , and historical data 710 . As shown in column 704 , exemplary descriptive data 706 comprises battery water level 712 , battery temperature 714 , and battery state-of-charge 716 . Additionally, exemplary real-time performance data comprises battery faults 718 , battery capacity 720 , battery usage 722 , and battery charge rate 724 . Exemplary battery fault information is presented in Table 4, below. The battery fault information listed in Table 4 is illustrative and is not intended to be an exhaustive list. Those of ordinary skill in the art will recognize that other battery fault information may be used. Column 706 illustrates information derivable from the sample data in column 704 . A low water level condition 726 is indicated if the battery water level 712 falls below a predetermined water level. A low state-of-charge condition 728 is indicated if the battery state-of-charge falls below a predetermined state-of-charge level. A sub-optimized charging regimen 730 or a sub-par battery performance 732 may also be indicated based at least in part on device measurement data obtained from the battery 702 .
[0000]
TABLE 4
Fault Event Information
Charger Identifier
Charge Port
Fault Start Date
Fault Start Time
Fault End Date
Fault End Time
Fault Code
Fault Information
[0078] Charge Event Data is a type of real-time data. Exemplary real-time data is listed in Table 5, below. The charge event data listed in Table 5 is illustrative and is not intended to be an exhaustive list. Those of ordinary skill in the art will recognize that other charge event data may be used.
[0000]
TABLE 5
Charge Event Data
Charger Identifier
Charge Port
Charge Start Date
Charge Start Time
Charge End Date
Charge End Time
Charge Time
Charge Ahs
Charge KWhs
Charge Start Temperature
Charge End Temperature
Charge Start State-Of-Charge
Charge End State-Of-Charge
Charge Start Voltage
Charge End Voltage
Charge Start Current
Charge End Current
Charge Type
Charge Start Code
Charge Term Code
[0079] Exemplary battery charge parameters are listed in Table 6, below. The battery charge parameters listed in Table 6 is illustrative and is not intended to be an exhaustive list. Those of ordinary skill in the art will recognize that other battery charge parameters may be used.
[0000]
TABLE 6
Battery Charge Parameters
Battery Identifier
Truck Identifier
Battery Type
Number of Cells
Battery Capacity
Start Current Limit
FC State-Of-Charge Limit
Maximum Ahs between
Maximum Days Between Equalizations
Equalization day of week
Internal Resistance
Target Voltage Limit
Temperature Fold back Coefficient
[0080] Column 708 illustrates exemplary automatic control measures that may be initiated based at least in part on the indicators in column 706 . In more detail, a low water level indication triggers a command to a watering system 742 that effectuates automatic watering of the battery 702 . A low battery state-of-charge triggers a reduction of temperature fold back in small steps per week 736 . A sub-optimized charging regimen 730 triggers an adjustment of the charge rates. Sub-par battery performance 732 triggers initiation of unscheduled battery equalization
[0081] Turning now to FIG. 8 , a data flow diagram that illustrates automatic control of one or more vehicles based at least in part on device measurement data obtained from the one or more vehicles and from one or more batteries associated with the one or more vehicles in accordance with one embodiment of the present invention is presented. As shown in column 802 , the types of data used for automatic control of the one or more vehicles comprises vehicle identification data 804 , vehicle real-time descriptive data 806 , vehicle real-time performance data 808 , vehicle and battery historical data 810 , and battery real-time descriptive data, identification data, and real-time performance data 812 . As shown in column 804 , exemplary vehicle real-time descriptive data 806 comprises energy usage 814 and charge compliance 816 . Additionally, exemplary vehicle real-time performance data comprises faults 818 . Exemplary battery real-time performance data comprises the battery state of charge 820 . Column 806 illustrates information derivable from the sample data in column 804 . Energy usage data 814 , charge compliance data 816 , and fault data 818 may be used to determine whether the vehicle energy usage is sub-optimal 822 . An indication 824 is also made if the battery state of charge 820 is less than a predetermined amount. As shown in column 808 , exemplary automatic vehicle control actions comprise adjusting the vehicle traction acceleration 826 , adjusting the vehicle speed 828 , or adjusting the vehicle lift rates 830 (if the vehicle comprises a fork lift) when the vehicle energy usage is sub-optimal. Exemplary vehicle control actions also comprise performing a lift lockout 832 when the battery state of charge is less than a predetermined amount 824 .
[0082] Column 808 illustrates exemplary automatic control measures that may be initiated based at least in part on the indicators in column 806 . In more detail, a low water level indication triggers a command to a watering system 842 that effectuates automatic watering of the battery 802 . A low battery state-of-charge triggers a reduction of temperature fold back in small steps per week 836 . A sub-optimized charging regimen 830 triggers an adjustment of the charge rates. Sub-par battery performance 832 triggers initiation of unscheduled battery equalization.
[0083] Turning now to FIG. 9 , a high level block diagram that illustrates a system for issuing one or more management recommendations based at least in part on device measurement data obtained from one or more devices in accordance with one embodiment of the present invention is presented. As shown in FIG. 9 , one or more devices 906 comprises a local device controller 940 adapted to control the one or more devices 906 based at least in part on one or more commands from manual control means 938 . According to one embodiment of the present invention, one or more devices 906 and remote device controller 902 are operatively coupled via a dedicated communication means. According to another embodiment of the present invention, the one or more devices 906 and remote device manager 902 are operatively coupled via a network (not shown in FIG. 9 ).
[0084] Still referring to FIG. 9 , remote device manager 902 comprises an analyzer 918 and an adviser 928 . Analyzer 918 is adapted to update one or more usage profiles 920 based at least in part on one or more of the identification data, the historical data, and the real-time data that comprises the device measurement data 908 .
[0085] The one or more usage profiles 920 comprise information regarding the use of the one or more devices 906 . The one or more usage profiles 920 may be stored in a memory associated with the remote device manager 902 .
[0086] Adviser 928 is adapted to issue one or more management recommendations to a user 942 , based at least in part on the device measurement data 908 obtained from the one or more devices 906 .
[0087] In operation, device measurement data 908 is transferred from the one or more devices 906 to remote device manager 902 . According to one embodiment of the present invention, the transfer is initiated by the one or more devices 906 . According to another embodiment of the present invention, the transfer is initiated by the remote device manager 902 . Analyzer 918 updates one or more usage profiles 920 based at least in part on one or more of the identification data, the historical data, and the real-time data that comprises the device measurement data 908 . Advisor 928 issues one or more management recommendations 936 to a user 942 , based at least in part on the device measurement data 908 obtained from the one or more devices 906 .
[0088] Turning now to FIG. 10 , a high level control flow diagram that illustrates issuing one or more management recommendations based at least in part on device measurement data obtained from one or more devices in accordance with one embodiment of the present invention is presented. FIG. 10 corresponds with FIG. 9 and provides more detail for reference numeral 4 A 30 of FIG. 4A . The processes illustrated in FIG. 10 may be implemented in hardware, software, firmware, or a combination thereof. At 1000 , a usage profile corresponding to a device is analyzed to provide recommendations with respect to management of the particular device, as well as other assets. The usage profile comprises performance data of the device gathered over a period of time. At 1005 , a determination is made regarding whether the device usage is sub-optimal. If the device usage is sub-optimal, at 1010 a management recommendation is issued.
[0089] According to one embodiment, a management recommendation comprises an asset rotation recommendation. The asset rotation recommendation may be based at least in part on the capabilities of a device and the workload of the device with respect to capabilities and workloads of other devices.
[0090] According to another embodiment, a management recommendation comprises an asset reduction recommendation. According to another embodiment, a management recommendation comprises an asset addition recommendation. The asset reduction recommendation and the asset addition recommendation may be based at least in part on the capabilities of fleet devices and the workload of the fleet devices.
[0091] A management recommendation may be delivered to the user 942 many ways. According to one embodiment of the present invention, a management recommendation is delivered to user 942 via a phone call. By way of example, the phone number of a phone associated with user 942 is dialed and when the phone is answered, an audio message regarding the management recommendation is played for user 942 to hear. According to one embodiment of the present invention, a management recommendation is delivered to user 942 via a pager. By way of example, a text message regarding the management recommendation is sent to the pager number of a pager associated with user 942 . According to one embodiment of the present invention, a management recommendation is delivered to user 942 via an email message. By way of example, a text message comprising a management recommendation, or a Universal Resource Locator (URL) that references a management recommendation, is delivered in an email message to an email address associated with user 942 . According to one embodiment of the present invention, a management recommendation is delivered to user 942 via a message on a display screen. By way of example, a management recommendation is rendered on a display screen associated with user 942 . According to one embodiment of the present invention, a management recommendation is delivered to user 942 via an alarm. By way of example, an audio message regarding the management recommendation may be played over a public address system of a facility associated with the user 942 . As another example, an audio message or an audio-video message regarding the management recommendation may be played on a computing device adapted to render audio messages and associated with the user 942 . The audio or audio-video message may comprise one or more of a verbal message and a nonverbal message (e.g. one or more “beeps” or other sounds associated with a particular management recommendation). According to another embodiment of the present invention, a management recommendation comprises two or more of the types of management recommendations mentioned above.
[0092] Turning now to FIG. 11 , a low level data flow diagram that illustrates issuing one or more management recommendations based at least in part on device measurement data obtained from one or more vehicles and from one or more batteries associated with the one or more vehicles in accordance with one embodiment of the present invention is presented. As shown in column 1102 , the types of data used for issuing one or more management recommendations comprises vehicle and battery identification data 1104 , vehicle and battery real-time descriptive data 1112 , vehicle and battery real-time performance data 1114 , and vehicle and battery historical data 1116 . Column 1106 illustrates information derivable from the sample data in column 1102 . The data 1118 may be used to determine whether there is sub-optimal usage of vehicle assets, battery assets, or both, whether one or more operators are underutilized, and whether a schedule is inefficient 1120 . As shown in column 1108 , exemplary management recommendations comprise one or more of recommendations for increasing the number of operators, reducing the number of operators, rearranging the shift schedule, using a different utility schedule, training operators, using 3PL, using peak-season rentals, reevaluating maintenance schedules, reducing the rental fleet, using a capital purchase instead of leasing, leasing instead of using a capital purchase, use different type of vehicle when a vehicle needs to be replaced, using a different type of battery when a battery needs to be replaced, increasing the fleet size, decreasing the fleet size, and rotating batteries or vehicles according to actual usage 1122 . The management recommendation 1108 is presented to a user 1130 who is free to make a management decision 1128 based at least in part on the management recommendation 1108 .
[0093] The management recommendations listed at 1122 are illustrative and are not intended to be an exhaustive list. Those of ordinary skill in the art will recognize that other management recommendations may be used.
[0094] Turning now to FIG. 12 , a high level block diagram that illustrates a system for issuing one or more user alerts based at least in part on device measurement data obtained from one or more devices in accordance with one embodiment of the present invention is presented. As shown in FIG. 12 , device 1206 comprises a local device controller 1240 adapted to control the one or more devices 1206 based at least in part on one or more commands from manual control means 1238 . According to one embodiment of the present invention, device 1206 and remote device controller 1202 are operatively coupled via a dedicated communication means. According to another embodiment of the present invention, device 1206 and remote device manager 1202 are operatively coupled via a network (not shown in FIG. 12 ).
[0095] Still referring to FIG. 12 , remote device manager 1202 comprises an analyzer 1218 and an alerter 1228 . Analyzer 1218 is adapted to update one or more usage profiles 1220 based at least in part on one or more of the identification data, the historical data, and the real-time data that comprises the device measurement data 1208 .
[0096] The one or more usage profiles 1220 comprise information regarding the use of the one or more devices 1206 . The one or more usage profiles 1220 may be stored in a memory associated with the remote device manager 1202 .
[0097] Analyzer 1218 comprises one or more of a historical data analyzer 1222 , a schedule milestone recognizer 1224 , and an exception recognizer 1226 . Historical data analyzer 1222 is adapted to analyze historical data, schedule milestone recognizer is adapted to analyze schedule milestones, and exception recognizer 1226 is adapted to recognize exceptions. Alerter 1224 is adapted to issue one or more user alerts to the user 1242 , based at least in part on the device measurement data 1208 obtained from the one or more devices 1206 . Manual control means 1238 may be used by user 1242 to control the one or more devices 1206 based at least in part on one or more user alerts received from alerter 224 . Manual control means 1238 comprises an input device, such as alphanumeric keyboard 118 , numeric keyboard 118 , joystick 116 , roller 114 , directional navigation pad 126 , or display screen 110 of FIG. 1 .
[0098] In operation, device measurement data 1208 is transferred from device 1206 to remote device manager 1202 . According to one embodiment of the present invention, the transfer is initiated by the one or more devices 1206 . According to another embodiment of the present invention, the transfer is initiated by the remote device manager 1202 . Analyzer 1218 updates one or more usage profiles 1220 based at least in part on one or more of the identification data, the historical data, and the real-time data that comprise the device measurement data 1208 . Historical data analyzer 1222 of analyzer 1218 analyzes historical data. Schedule milestone recognizer 1224 of analyzer 1218 analyzes schedule milestones. Exception recognizer 1226 of analyzer 1218 analyzes exceptions. Alerter 1228 issues one or more user alerts to the user 1242 , based at least in part on the one or more usage profiles 1220 .
[0099] Turning now to FIG. 13 , a high level control flow diagram that illustrates issuing one or more user alerts based at least in part on device measurement data obtained from one or more devices in accordance with one embodiment of the present invention is presented. FIG. 13 corresponds with FIG. 12 and provides more detail for reference numeral 4 A 40 of FIG. 4A . The processes illustrated in FIG. 3 may be implemented in hardware, software, firmware, or a combination thereof. At 1300 , a usage profile corresponding to a device is analyzed. At 1305 , one or more historical usage or performance profiles associated with the one or more devices are analyzed. At 1310 , one or more maintenance schedule milestones associate with the one or more devices are analyzed. At 1315 , a determination is made regarding whether the fault codes indicate a fault. At 1320 , a determination is made regarding whether the one or more profiles indicate a fault. At 1325 , a determination is made regarding whether the maintenance schedule indicates a fault. If a fault is indicated at 1315 , 1320 , or 1325 , a user alert corresponding to the particular fault is issued at 1330 .
[0100] While the operations shown in FIG. 13 are illustrated in a specific order, other sequences of the operations are conceivable. For example, the order of processes 1300 , 1305 , and 1310 with respect to each other is not important. Additionally, the order of determinations 1315 , 1320 , and 1325 with respect to each other is not important.
[0101] According to one embodiment of the present invention, a user alert comprises a compliance alert. By way of example, if a user responsible for a particular vehicle charges the vehicle less frequently than suggested, a user alert informs the user of the non-compliance.
[0102] According to another embodiment of the present invention, a user alert comprises a warranty period ending alert. By way of example, if the warranty for a particular device will end within a predetermined amount of time, a user alert informs the user of this fact.
[0103] According to another embodiment of the present invention, a user alert comprises a non-warranty replacement alert.
[0104] According to another embodiment of the present invention, a user alert comprises a maintenance alert. By way of example, if the maintenance schedule of a device indicates maintenance should be performed and it has not yet been performed, a user alert informs the user of this fact.
[0105] According to another embodiment of the present invention, a user alert comprises a charger service alert. By way of example, if a charger requires unscheduled service, a user alert informs the user of this fact.
[0106] According to another embodiment of the present invention, a user alert comprises a vehicle service alert. By way of example, if a vehicle requires unscheduled service, a user alert informs the user of this fact.
[0107] According to another embodiment of the present invention, a user alert comprises a battery service alert. By way of example, if a battery requires unscheduled service, a user alert informs the user of this fact.
[0108] A user alert may be delivered to the user 1242 many ways. According to one embodiment of the present invention, a user alert is delivered to user 1242 via a phone call. By way of example, the phone number of a phone associated with user 1242 is dialed and when the phone is answered, an audio message regarding the user alert is played for user 1242 to hear. According to one embodiment of the present invention, a user alert is delivered to user 1242 via a pager. By way of example, a text message regarding the user alert is sent to the pager number of a pager associated with user 1242 . According to one embodiment of the present invention, a user alert is delivered to user 1242 via an email message. By way of example, a text message comprising a user alert, or a Universal Resource Locator (URL) that references a user alert, is delivered in an email message to an email address associated with user 1242 . According to one embodiment of the present invention, a user alert is delivered to user 1242 via a message on a display screen. By way of example, a user alert is rendered on a display screen associated with user 1242 . According to one embodiment of the present invention, a user alert is delivered to user 1242 via an alarm. By way of example, an audio message regarding the user alert may be played over a public address system of a facility associated with the user 1242 . As another example, an audio message or an audio-video message regarding the user alert may be played on a computing device adapted to render audio messages and associated with the user 1242 . The audio or audio-video message may comprise one or more of a verbal message and a nonverbal message (e.g. one or more “beeps” or other sounds associated with a particular user alert). According to another embodiment of the present invention, a user alert comprises two or more of the types of user alerts mentioned above.
[0109] Turning now to FIG. 14 , a low level data flow diagram that illustrates issuing one or more user alerts based at least in part on device measurement data obtained from one or more vehicles and from one or more batteries associated with the one or more vehicles in accordance with one embodiment of the present invention is presented. As shown in column 1402 , the types of data used for issuing one or more user alerts comprises vehicle and battery identification data 1410 , vehicle real-time descriptive data 1412 , vehicle and battery real-time performance data 1414 , and vehicle and battery historical data 1416 . As shown in column 1404 , exemplary identification data 1410 comprises a vehicle maintenance schedule 1418 . Exemplary vehicle real-time descriptive data 1412 comprises battery capacity 1420 . Exemplary vehicle and battery real-time performance data comprise faults. Column 1406 illustrates information derivable from the sample data in column 1404 . The data 1404 may be used to determine whether the time for scheduled maintenance is near, whether a warranty period has ended 1424 , whether operator compliance procedures are being followed 1426 , whether a battery is displaying low capacity 1428 , and whether a battery, vehicle, or charger requires maintenance 1430 . As shown in column 1408 , exemplary user alerts comprise indicating a warranty period is ending 1432 , indicating maintenance is required 1434 , indicating an operator is operating a vehicle in a noncompliant manner 1440 , indicating a battery requires either (1) full or cell replacement, or (2) service 1442 , and indicating another charger, vehicle, or battery service alert. The user alert 1404 is presented to a user 1448 who is free to make a management decision 1446 based at least in part on the user alert 1404 .
[0110] FIGS. 15-17 illustrate dynamic control of one or more devices based at least in part on device measurement data collected from the one or more devices in accordance with embodiments of the present invention.
[0111] Turning now to FIG. 15 , a block diagram that illustrates dynamic control of one or more chargers based at least in part on device measurement data collected from the one or more chargers and one or more vehicles associated with the one or more chargers in accordance with one embodiment of the present invention is presented. As shown in FIG. 15 , multiple vehicles ( 1534 , 1536 ) are operatively coupled to a remote device manager 1502 via a network 1544 . The remote device manager 1502 receives device measurement data 1508 from the vehicles ( 1534 , 1536 ) and the chargers associated with the vehicles ( 1534 , 1536 ). The remote device manager 1502 analyzes the device measurement data 1508 and issues one or more commands based at least in part on the analysis. The BMID parameters may be adjusted to optimize charging rates and to reduce battery temperature. The BMID parameters may also be adjusted to maximize battery state-of-charge based at least in part on the charging history. Additionally or as an alternative thereto, unscheduled battery equalization may be initiated to address battery performance issues.
[0112] Turning now to FIG. 16 , a block diagram that illustrates dynamic control of one or more chargers and one or more vehicles associated with the one or more chargers based at least in part on device measurement data collected from the one or more chargers and the one or more vehicles in accordance with one embodiment of the present invention is presented. As shown in FIG. 16 , multiple vehicles ( 1634 , 1636 ) are operatively coupled to a remote device manager 1602 via a network 1644 . The remote device manager 1602 receives device measurement data 1608 from the vehicles ( 1634 , 1636 ) and the chargers associated with the vehicles ( 1634 , 1636 ). The remote device manager 1602 analyzes the device measurement data 1608 and issues one or more commands 1636 based at least in part on the analysis. A rotational schedule that maximizes asset life of batteries and vehicles may be recommended. A future asset replacement time may be anticipated based at least in part on battery performance. Vehicle, battery, or charger fault numbers may be recorded and communicated to customer support personnel. Vehicle performance levels may be adjusted to conserve energy, based at least in part on battery usage and state-of-charge data. Battery charging rates may be adjusted based at least in part on historical plug-in times, battery energy usage, and minimum battery state-of-charge data to conserve energy and reduce peak demand costs. A vehicle reduction recommendation or utilization plan may be presented. Customers, operators, or both, may be alerted with respect to compliance issues. Batteries may be automatically watered based at least in part on a water level threshold.
[0113] Turning now to FIG. 17 , a block diagram that illustrates dynamic control of one or more chargers based at least in part on device measurement data collected from the one or more chargers an in accordance with one embodiment of the present invention is presented. As shown in FIG. 17 , multiple vehicles ( 1734 , 1736 ) are operatively coupled to a remote device manager 1702 via a network 1744 . The remote device manager 1702 receives device measurement data 1708 from the vehicles ( 1734 , 1736 ) and the chargers associated with the vehicles ( 1734 , 1736 ). The remote device manager 1702 analyzes the device measurement data 1708 and issues one or more commands 1736 based at least in part on the analysis. The BMID parameters may be adjusted to optimize charging rates and to reduce battery temperature. The BMID parameters may also be adjusted to maximize battery state-of-charge based at least in part on the charging history.
[0114] Turning now to FIG. 18 , a flow diagram that illustrates a method for battery fault management in accordance with one embodiment of the present invention is presented. FIG. 18 exemplifies issuing user alerts, issuing management recommendations, and automatically controlling attributes or operations of one or more devices based at least in part on device measurement data obtained from the one or more devices. The processes illustrated in FIG. 18 may be implemented in hardware, software, firmware, or a combination thereof. At 1800 , a determination is made regarding whether a battery is overheating. If the battery is not overheating, at 1802 a determination is made regarding whether the battery has a low state-of-charge. If the battery has a low state-of-charge, at 1820 a determination is made regarding whether the battery has at least one bad cell. If the battery has at least one bad cell, a battery replacement request is sent at 1822 . If the battery does not have at least one bad cell, at 1824 a determination is made regarding whether the battery usage is too high. If the battery usage is too high, at 1826 an alert message is sent, warning that the vehicle performance should be reduced, or the number of vehicles should be increased. If the battery usage is not too high, at 1828 a determination is made regarding whether plug-in compliance procedures are being adhered to. If the plug-in compliance procedures are not being adhered to, at 1830 an alert message is sent. If plug-in compliance procedures are being adhered to, at 1832 the temperature fold back is decreased in small steps, one step per week, until the battery state-of-charge is maintained below a first predetermined limit and the battery temperature does not exceed a second predetermined limit.
[0115] Still referring to FIG. 18 , if battery overheating is indicated at 1800 , at 1804 a determination is made regarding whether the battery water level is low. If the battery water level is low, at 1806 an alert message is sent. The alert message may be sent to one or more persons or entities. By way of example, the alert message may be sent to one or more of the shift supervisor, the battery supplier, and the supplier of a device associated with the battery. Alternatively or in addition thereto, the battery is automatically watered. If the battery water level is not low, at 1808 a determination is made regarding whether the battery has at least one bad cell. If the battery has at least one bad cell, a battery replacement request is sent at 1810 . The battery replacement request may be sent to one or more persons or entities. By way of example, the battery replacement request may be sent to one or more of a battery service provider, the battery supplier, and the supplier of a device associated with the battery. If the battery does not have at least one bad cell, at 1812 a determination is made regarding whether the battery usage is too high. If the battery usage is too high, at 1814 a determination is made regarding whether plug-in compliance procedures are being adhered to. If the plug-in compliance procedures are not being adhered to, at 1816 an alert message is sent. If plug-in compliance procedures are being adhered to, at 1818 the temperature fold back is increased in small steps, one step per week, until the battery temperature is maintained below the second predetermined limit.
[0116] While the operations shown in FIG. 18 are illustrated in a specific order, other sequences of the operations are conceivable. For example, one or both of determinations 1804 and 1808 and their associated actions (reference numerals 1806 and 1810 ) may occur after determination 1814 . Additionally, one or more of determinations 1820 and 1824 and their associated actions (reference numerals 1822 and 1826 ) may occur after determination 1828 .
[0117] While embodiments of the present invention have been illustrated with respect to fork lifts having a replenishable battery pack, those of ordinary skill in the art will recognize that any device powered by a replenishable device may be used.
[0118] While embodiments and applications of this invention have been shown and described, it would be apparent to those skilled in the art having the benefit of this disclosure that many more modifications than mentioned above are possible without departing from the inventive concepts herein. The invention, therefore, is not to be restricted except in the spirit of the appended claims. | 4y
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This is a continuation of U.S. patent application Ser. No. 12/330,871 filed Dec. 9, 2008, which claims the priority date of U.S. Provisional Application Ser. No. 61/062,380, entitled “COMPOUND ARCHERY BOW” filed Jan. 25, 2008.
FIELD OF THE INVENTION
[0002] This invention relates to compound bows, and more specifically, it relates to a two-track system for bow strings and power cables of the compound bow.
BACKGROUND OF THE INVENTION
[0003] Cams have been used on compound bows for some time. Compound bows have opposing limbs extending from a handle portion which house the cam assemblies. Typically, the cam assemblies are rotatably mounted on an axel which is then mounted on a limbs of bow. The compound bows have a bow string attached to the cam which sits in a track and also, generally, two power cables that each sit in a track on a separate component on the cam, and either anchored to the cam or a limb/axel. When a bowstring is pulled to full draw position, the cam is rotated and the power cables are “taken up” on their respective ends to increase energy stored in the bow for later transfer, with the opposing ends “let out” to provide some give in the power cable.
[0004] Cam assemblies are designed to yield efficient energy transfer from the bow to the arrow. Some assemblies seek to achieve a decrease in draw force closer to full draw and increase energy stored by the bow at full draw for a given amount of rotation of the cam assembly.
[0005] There exists a number of U.S. patents directed to compound bows, including U.S. Pat. No. 7,305,979 issued to Craig Yehle on Dec. 11, 2007. The Yehle patent discloses a cam assembly having a journal for letting out a draw cable causing the cam to rotate and two other journals for take-up mechanism and a let-out mechanism for the two power cables. The Yehle patent requires that the power cables and draw string each sit in a different components and tracks for the take up and let out mechanism to work and to have the efficiencies described therein.
[0006] Therefore, a compound bow having a mechanism with fewer tracks is desired because of the advantage in assembly in manufacturing and to increase efficiency in the transfer of energy to propel bows.
[0007] Further, an adjustable or modular take-up/let-out mechanism is desired to account for different size draw lengths or other specifications required by the user.
SUMMARY OF THE INVENTION
[0008] The invention comprises, in one form thereof, a cam assembly comprising bowstring cam component having a track for receiving a bowstring; and a power cable cam component having a take up portion and a let out portion, wherein the take up and let out portion have a track for receiving a power cable.
[0009] More particularly, the invention includes a compound bow comprising a handle portion; a limb portion; at least two cam assemblies, each comprising a bowstring cam component having a track for receiving a bowstring; and a power cable cam component having a take up portion and a let out portion, wherein the take up and let out portion have a track for receiving a power cable, a draw stop pin, a take up terminating post, and a let out terminating post; an axel; at least two power cables; and a bowstring.
[0010] The cam assembly has a two track system wherein the power cables utilize a track or opposing tracks made on the power cable component of the cam assembly. Another track is formed on the bowstring component of the cam assembly in which the bowstring lies.
[0011] An advantage of the present invention is that the device has high efficiency in transferring energy stored in the limbs during the draw cycle to the arrow or other projectile of the device.
[0012] A further advantage of the present invention is that it requires less component parts for cam assembly which is highly desirable in the art.
[0013] An even further advantage of the present invention is that the cam assembly allows for a modular format which allows the user to change minor components to change parameters of the device (e.g. draw length) without having to change the entire cam assembly or bow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention is disclosed with reference to the accompanying drawings, wherein:
[0015] FIG. 1 is a side view of a dual cam compound bow embodying the present invention;
[0016] FIG. 2 is a side view of the top cam assembly in a first embodiment of the present invention.
[0017] FIG. 3 is a rearview of the top cam assembly in a first embodiment of the present invention.
[0018] FIG. 4 is a side view of the bottom cam assembly in a first embodiment of the present invention.
[0019] FIG. 5 is a rearview of the bottom cam assembly in a first embodiment of the present invention.
[0020] FIGS. 6 and 7 show the modular form of the let out portion 64 a,b with the draw stop pin 90 a,b attached thereto.
[0021] FIG. 8 is a side view of the top cam assembly in a second embodiment of the present invention.
[0022] FIG. 9 is a side view of the bottom cam assembly in a second embodiment of the present invention.
[0023] FIG. 10 is a side view of the top cam assembly in a third embodiment of the present invention.
[0024] FIG. 11 is a side view of the bottom cam assembly in a third embodiment of the present invention.
[0025] FIG. 12 is a rearview of the top cam assembly in a fourth embodiment of the present invention.
[0026] FIG. 13 is a rearview of the bottom cam assembly in a first embodiment of the present invention.
[0027] Corresponding reference characters indicate corresponding parts throughout the several views. The examples set out herein illustrate a few embodiments of the invention but should not be construed as limiting the scope of the invention in any manner.
DETAILED DESCRIPTION
[0028] FIG. 1 shows a dual cam compound bow 10 of the present invention. The bow 10 has a frame, which includes bow limbs 12 a,b extending from handle 14 . Extending from the handle is cable guard 16 and a cable slide 18 through which the power cables 50 and 52 are placed. The bowstring 70 and power cables 50 , 52 are attached to the bow 10 at the cam assemblies 30 a,b , which further is placed on the limbs via axel 36 a,b . The cams 30 a,b are shown in greater detail in the following figures.
[0029] The cams 30 a,b have bowstring assemblies 40 a,b , each having a single track for the bowstring 70 with each end of the bowstring 70 being attached to the cams 30 a,b at a terminating post (not shown). Further, the each of the cams 30 a,b have terminating posts 80 , 82 for each of the ends of the respective power cables 50 , 52 , and which will be described in more detail herein. Further, each cam assembly 30 a,b has a power cable assembly 60 a,b having either a single track or groove around perimeter of the assembly 60 a,b for receiving or retaining the power cables. Alternatively, the power cable assembly 60 a,b can have the tracks or grooves on the portions of the assembly receiving the cable instead of a unitary track around the perimeter. The power cable assembly 60 a,b has a take up portion 62 a,b and a let out portion 64 a,b for managing the take up and let out of the power cables through a single track.
[0030] FIG. 2 shows a side view of the top cam assembly 30 a . FIG. 2 shows one embodiment of the cam 30 a in non-circular shape. The bowstring 70 is in line with the track in the bowstring assembly 40 a and attached with a terminating post (not shown). The power cable assembly 60 a has a take up portion 62 a and a let out portion 64 a , and can either be a unitary piece or be modular. For instance as shown in FIG. 2 , the power cable assembly 60 a has a modular unit for the let out portion 64 a , which allows manufacturers to make a single cam assembly with one small piece that can account for varying sizes and preferences by the user. Specifically, this versatility is important because each hunter or archer has different specifications (e.g. draw length) which can be accounted for by having a modular portion to the cam assembly 30 a , and in this case is the let out portion 64 a . The power cable 52 , in FIG. 2 , is attached to terminating post 82 a and wraps around the let out portion 64 a and therefore feeds power cable 52 out when the bow is in full draw. On the opposing side of power cable assembly 60 a is power cable 50 , which sits on the take up portion 62 a of the assembly 60 a . Power cable 50 is attached at terminating post 80 a , and is taken up when the bow is in full draw by the take up portion 62 a . The power cable assembly 60 a is attached to the bowstring assembly 30 a by a fastening mechanism, but it will be well recognized the power cable assembly 60 a can be attached to the bowstring assembly 40 a by any means or, if desired, manufactured as a single piece with the bowstring assembly 40 a to make-Lip top cam assembly 30 a . As shown, the power cable assembly 60 a is attached to the bowstring assembly 40 a by a fastener 78 a . The cam assembly 30 a is attached to the limb 12 a by axel 36 a . Last the take power cable assembly 60 a , either in a unitary form or modular form, may optionally have draw stop pin 90 a attached to stop the draw cycle of the bow. The draw stop pin 90 a , however, does not have to be attached to the power cable assembly 60 a in order to function on the cam assembly 30 a.
[0031] FIG. 3 shows the rearview of the top cam assembly. As seen from this perspective, the cam assembly 30 a has one track on the bowstring assembly 40 a for the bowstring 70 and a second track for the power cables 52 and 50 (not shown) on same track but on opposing sides of the power cable assembly 60 a . In FIG. 3 , the let out portion 64 a is visible with power cable 52 sitting in the track or groove. Axel 36 a is inserted through the limb 12 a and then the cam assembly 30 a and then the other end of the limb 12 a.
[0032] FIG. 4 shows a side view of the bottom cam assembly 30 b . FIG. 4 shows the bottom cam 30 b in non-circular shape as well. The bowstring 70 is in bowstring assembly 40 b and attached with a terminating post (not shown). The power cable assembly 60 b has a take up portion 62 b and a let out portion 64 b , which can either be a unitary piece or as shown can have a modular unit. In FIG. 4 , there is a modular assembly shown where the let up portion 64 b can be changed in size and shape according to the user's specifications. The power cable 52 , in FIG. 4 , is attached to terminating post 80 b and wraps around the take up portion 62 b and therefore is taken up when the bow is in full draw. On the opposing side of power cable assembly 60 b is power cable 50 , which attaches to terminating post 82 b and wraps around the let out portion 64 b , and is let out when the bow is in full draw position. The power cam assembly 60 b is attached to the bowstring assembly 30 b by a fastening mechanism, the two assemblies can be attached by any means or if desired manufactured as a single piece. As shown, the power cable assembly 60 b is attached to the bowstring assembly 40 b by a fastener 78 b . The cam assembly 30 b is attached to the limb 12 b by axel 36 b . Last the power cable assembly 60 b , either in a unitary or modular form, may optionally have draw stop pin 90 b attached to stop the draw cycle of the bow.
[0033] FIG. 5 shows the rearview of the bottom cam assembly 30 b . As seen from this perspective, the cam assembly 30 b has a bowstring assembly 40 b for the bowstring 70 , and a power cable assembly 60 b for both power cables 50 , 52 . In FIG. 5 , power cable 50 is visible because it is sitting on the let out portion 64 b of the power cable assembly 60 b . Axel 36 b allows bottom cam assembly 30 b to rotate when the drawstring is pulled, and holds bottom cam assembly 30 b in limb 12 b.
[0034] FIGS. 6 and 7 show the modular form of the let out portion 64 a,b and draw stop pin 90 a,b for the cam assemblies 30 a,b . The let out portion 64 a,b and draw stop pins 90 a,b can be attached in any number of ways or can be further manufactured as a unitary piece. Further, as described above, let out portion 64 a,b can be manufactured as a single part of power cable assembly 60 a,b . Therefore, though the modular form is more desirable to personalize the parameters of the device size (e.g. draw length), the cam assembly could be manufactured as a single unit or in varying degrees of pieces.
[0035] FIGS. 8 and 9 show a side view of a second embodiment of the present invention 100 a,b . FIG. 8 shows the top cam assembly 100 a is in a circular shape. In particular, the power cable assembly 120 a is shown as being in a unitary form, having the take up portion 122 a and let out portion 124 a . The draw stop pin 90 a is not attached to the power cable assembly 120 a , though if preferred the assembly 120 a could be attached to the pin 90 a . Further the bowstring assembly 110 a is also in a circular or disc shape with power cable assembly 120 a attached thereto. FIG. 9 exemplifies the bottom cam assembly 100 b for the second embodiment, which is in a circular or disc shape. Generally the other components of the cam assemblies 100 a,b are similar to those shown in the first embodiment.
[0036] FIGS. 10 and 11 show a third embodiment of the present invention, wherein the cam assembly 200 a,b have a circular portion for the bowstring track 110 a,b and a non-circular power cable assembly 60 a,b . It will be understood that other embodiments could include a non-circular portion for the bowstring assembly and a circular power cable assembly and, again, can be either modular or unitary form. Further other geometrical shapes, such as ovular, may be used in varying forms for either the bowstring or power cable assembly.
[0037] Still another embodiment could include a three track system, as shown in the rearview perspectives of FIGS. 12 and 13 . The three track system would be used where there are four power cables. This type of embodiment would include two power cable assemblies as described above, both of which would be attached to the bowstring assembly.
[0038] In use, using the first embodiments as an exemplar and in reference to FIGS. 1-3 , the bowstring 70 is pulled rearward toward the hunter or archer. The tension by the bowstring forces the cam assemblies 30 a,b to rotate rearward. Focusing on FIG. 1 , the power cable assembly 60 a on top cam assembly 30 a is moved upward as the entire cam 30 a is moved rearward. The terminating post 80 , with power cable 50 attached, moves upward, and therefore causes take up of power cable 50 . On the bottom cam assembly 30 b the cam 30 b is also moved rearwardly. The positioning of the power cable assembly 60 and power cable 50 causes power cable 50 to be let out on the bottom cam assembly 30 a . The same is true in the opposite manner for power cable 52 (i.e. power cable 52 is taken up) on the cam assemblies 30 a,b . Accordingly energy is stored in the limbs of the device and transferred to the arrow or other projectile placed in the compound bow in a highly efficient manner with little shock to the user.
[0039] Though the compound bow embodying the invention may have differing specifications, the bow may have a brace height of about eight (8) inches and axel-to-axel length of about thirty-two and half (32½) inches. The draw length can range from twenty-seven (27) to thirty (30) inches and a draw weight between sixty (60) to eighty (80) inches.
[0040] It should be particularly noted that dual track cam disclosed in this invention has a highly efficient and powerful performance. With respect to speed, the following performance results were noted in a twenty-nine (29″) inch draw cycle, sixty pound (60 lbs.) draw weight compound bow, in testing completed by Archery Evolution:
[0000]
Arrow (Grains)
300
360
420
540
Speed (ft./sec.)
307.3
283.5
264.2
235.4
Kinetic Energy (ft.lbs.)
62.9
64.2
65.1
66.4
Momentum
13.2
14.6
15.9
18.2
Dynamic Efficiency
83.7%
85.5%
86.7%
88.5%
Noise Output (dBA)
88.7
84.1
85.5
87.1
Total Vibration (G)
222.8
234.4
228.7
188.6
[0041] While the invention has been described with reference to particular embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the scope of the invention.
[0042] Therefore, it is intended that the invention not be limited to the particular embodiments disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope and spirit of the appended claims. | 4y
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BACKGROUND OF THE INVENTION
The prior art teaches a number of ways of automatically leveling the main frame of a construction machine during its advance along a grade, at a pre-determined and accurately held plane and height regardless of variations in the grade, slope or height of the ground being traversed. The prior art also teaches a number of ways of automatically leveling the working tool of a construction machine under the foregoing conditions. The means by which these results are accomplished and the accuracy of the end product of course vary as much as the number of teachings. The U.S. Pat. Nos. 3,249,026, 3,280,846, 3,292,511, 2,761,666, 3,710,695 and 3,606,827 are exemplary of these teachings and each has its advantages and disadvantages.
One of the problems facing the construction machine art has been the accurate control of the slope and grade of a working tool as the machine negotiates a path of travel over a rough grade. Various forms of suspension have been used between the working tool and the main frame of the machine or between the main frame, carrying a fixed tool, and the ground engaging means used to transport the machine. Machines of this type employ working tools that extend transversely of the main frame either in front of the frame, at a mid-point of the frame or at the rear of the frame. If the frame is adjusted in relation to the wheels or tractors and the tool is fixed to the frame then the location and number of supporting wheels and frame adjusting points become critical to the accurate control of the system.
Generally it is easier to maintain three suspension points in a plane than it is to maintain four suspension points in a plane. Attempts have been made to use large flexible frames to carry rigidly attached working tools and support the four corners of the frame on adjustable suspension means over a wheel or tractor at each corner. In this arrangement a grade reference on each side of the machine is required and the slope is determined by the co-planar relationship of the grade reference.
In order to eliminate one grade line, which has several known advantages, it is necessary to control the pair of suspension means on that side in a manner to maintain the required slope or level of the working tool. This is done by operating that pair of suspension means simultaneously from a gravity operated sensor to raise and lower that side of the frame.
The prior art machines fall into a number of categories: (a) those that employ large flexible frames and four corner supports between the frame and the ground engaging means, (b) those that employ rigid frames and either three or four supports between the frame and the ground engaging means, and (c) those that employ either flexible or rigid frames and adjustably support the tool in relation to the frame, using relatively rigid supports between the frame and the ground engaging means. It is apparent that the larger heavy machines, such as those which span one or more lanes of a highway, are easier to control and produce an end product meeting the accepted standards of grade and slope than smaller machines which because of their dimensions are subject to greater deviations in negotiating and correcting for given changes in grade, slope or level. In both large and small machines the working tool can be carried transverse the frame or longitudinal of the frame at various locations and the tool can be on either side of the main frame or in the so-called straddle position. Some machines are versatile enough to tolerate any type of tool mounting.
The art recognizes that the problems associated with frame and tool adjustment to control grade and slope for these purposes are not related, and the teachings from one art are not necessarily applicable to another. Likewise the suspensions used for a transverse tool do not translate into something useful for a side-mounted working tool. Thus a side-mounted tool such as illustrated by the Cheney U.S. Pat. No. 3,292,511 requires a vertical adjustment for height or grade control, a gravity responsive tilt correction and a pitch or grade correction. In the Cheney device, a change in pitch influences the height of the tool and a change in tilt.
Such construction machines include as their basic parts a main frame used to support one or more working tools; ground engagement or traction means such as wheels, skids or endless tracks, and various kinds of adjustable support means between the main frame and the ground engagement means or between the main frame and the working tool. The ground engagement means are in direct rolling or sliding contact with grade (the elevation), slope (the inclination); and the surface conditions encountered differ widely. Their common objective is to utilize adjustable frame or tool support means to maintain the frame and tool at a predetermined plane reflecting as near as possible a desired grade and slope irrespective of the irregularities of the ground over which the machine passes.
SUMMARY OF THE INVENTION
The invention is based on the use of mechanical means to isolate grade and slope corrections of a working tool from each other. A tool support is provided across the front of the machine. The tool support has a pair of rearwardly extending arm members that are located along the sides of the frame and are pivoted thereto on a common transverse axis. The forward ends of the arm members are supported from a frame extension by a pair of extendible members that operate in unison to raise and lower the tool support in an arc of relatively long radius about the transverse axis. The working tool is supported from the tool support by a single extensible member connected between the tool support and a central point of the working tool and also by a longitudinal pivot axis at one end of the working tool. This longitudinal pivot axis is located in the proximity of the grade reference or the so-called inboard side of the machine.
Thus the simultaneous operation of the pair of extensible members raises and lowers the tool support, the working tool, and its longitudinal axis support as a unit without changing the angular relationship of the working tool (the slope) in relation to the frame support. The operation of the single extensible member rotates the working tool in relation to the tool support without causing a significant change in grade as established by the pair of extensible members since the longitudinal pivot axis is contiguous to or in line with the grade reference.
The machine steers by articulation of the frame between the front and rear pairs of ground engaging means on which the machine travels.
DESCRIPTION OF THE DRAWINGS
Illustrative embodiments of the invention are shown in the drawings wherein:
FIG. 1 is an isometric view of a machine carrying the tool support means of this invention;
FIG. 2 is a fragmentary enlarged view of the frame articulation and steering means for the machine shown in FIG. 1;
FIG. 3 is a plan view of the machine showing a steering correction to the right;
FIG. 4 is a plan view of the machine showing a steering correction to the left;
FIG. 5 is a front view of the machine showing a slope correction of amplified magnitude for purposes of illustration;
FIG. 6 is a side view of the machine showing a grade correction of amplified magnitude for purposes of illustration; and
FIG. 7 is a schematic of the control system for the machine also showing the geometry of the suspension.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawings, particularly FIGS. 1, and 2, the machine 10, illustrated by a Vermeer Model 475 four wheel drive tractor manufactured by Vermeer Mfg. Corp., includes the front rigid frame section 12 which has the rigid auxillary frame members 14 defining a housing for the prime mover, the muffler therefore being illustrated at 16. Aft of the frame 12 and integral therewith is the canopy 18 and drivers seat 20. The housing portion for the prime mover is of low profile so the driver can check the operation of the machine at all times.
The frame 12 (See FIG. 2) is connected to the rear frame section 22 by means of the heavy duty universal joint 24 wherein these parts are pivotally connected to the pin 26 through the yoke member 27 in a manner known in the art. The lower arm 28 of the yoke 27 has a side arm 30 to which the rod 32 of the ram 34 is pivotally connected at the pin 36. The rear frame 22 is also pivoted on a second axis defined by the pin 37 oriented in the yoke at 90° to the axis of the pin 26 for full universal action, that is, allowing the front and rear frame sections to rotate on the axis 37 so that the wheels can negotiate obstructions on the grade. The other end of the ram 34 is pivotally connected to the frame 12 by means of the pin 38. The hydraulic lines leading to and from the ram 34 are omitted for simplicity.
Each frame part 12 and 22 carries a pair of rubber tired drive wheels, indicated by the front drive wheels 40 and the rear drive wheels 42, all driven in synchronism from the prime mover from a single transmission providing separate drive shafts (not illustrated) connected thereto through fixed axle differential units. The pairs of wheels 40 and 42 are fixed through their axles to the respective frame sections 12 and 22 there being no springs or other suspension means there between.
It is obvious that the extension and retraction of the ram 34 will cause the frame parts 12 and 22 supported as they are on their separate pairs of wheels to articulate in a horizontal plane about the pin 26. Also as each wheel negotiates a change in the grade it is free to raise or lower as the case may be. This type of universal joint is of very rugged construction and only allows the frame parts these two degrees of movement, there being little or not tendency for the parts to pivot on a transverse axis.
The frame section 12 carries the housing 44 for the gas tank, hydraulic oil tank and the other auxillary equipment for the machine, not involved in this invention except for operability as far as a source of motive power for the drive and hydraulic parts are concerned.
Across the front of the machine the tool support unit 50 is provided to comprise the transverse box beam 52 and a pair of upright rigid side members 54 and 56 affixed to its ends. The beam 52 extends in spaced relationship in front of the frame portion 14 and carries a pair of longitudinal arms 58 and 60 that extend in spaced relationship along the sides of the frame portion 12-14 where they are each attached to the frame by means of the respective pivot pins 62 and 64, (See FIG. 7) aligned transversely of the frame. The arms 58 and 60 are of equal length and coplanar with the beam 52. As before stated the frame section 14 of the Vermeer machine is very rugged allowing its use for the attachment of the pair of rams 66 and 68 by means of the top pivots 70 and 72 and the bottom pivots 74 and 76 attached to the respective side members 58 and 60. Again the hydraulic lines therefore are omitted in FIG. 1 for simplicity. Simultaneous operation of the rams 66 and 68 raises and lowers the tool support means 50 in an arc of relatively long radius about the pivots 62-64.
The working tool 80 is illustrated by an arcuate open-bottom housing 82 which carries therein an auger or cutter supported on the shaft 84 carried between the end plates 86 and 88 upon suitable enclosed bearings of a heavy duty type. A separate motor drive for the tool is carried in the housing 90 at one end (the outboard side) of the housing 82, in this instance a chain drive unit is intended so that the motor therefore can be located above the grade and out of the dust and dirt kicked up by the cutter. This motor is driven hydraulically, and under the control of the operator for stopping, starting and speed adjustment.
The housing 82 is suitably rigidified by the reinforcing plates 92 spaced therealong which are tied together along the back edge by the box beam 94.
The entire working tool 80 with its housing and drive means 90 is pivotally mounted at one end by the pivot pin 96 carried longitudinally of the frame (on the inboard side) and spaced to one side by the upright member 56 of the tool support means 50. The pin 96 is journaled in the pair of cleats 98 affixed to the side plate 86. The working tool 80 is vertically supported at about its center point (transverse the machine) by the single ram 100 which is pivotally attached to the upright support member 102, carried central of the box beam 52 and spaced forward of the frame unit 14, by means of the pivot pin 104 as illustrated. The piston rod 106 of the ram 100 is pivoted to the center or balance point of the entire working tool 80 by means of the pivot pin 108 carried by the box beam 94.
The housing 82 and cross beam 94 are unattached at the end (outboard side) opposite the longitudinal pivot pin 96 but may oscillate in an arc in guided relationship against the forward surface of the vertical beam 54. If desired rollers can be placed therebetween, the purpose being to provide some longitudinal (fore and aft) support for the working tool at this end so that the pivot pins 96 and 108 are under no strain as the tool progresses along and does work upon the rough grade 110.
The cuttings produced by the working tool are conveyed toward the outboard side of the machine and deposited therealong so that the wheels 40 and 42 of the machine travel on the finished grade 112 and the inboard side is clear for the placement of the grade reference line 114 supported by the posts 116 spaced therealong and having the vertically adjustable brackets 118 as are known in this art. If desired the rear top portion of the housing 82 can be open and an endless belt conveyor provided therealong on which the cutter deposites the earth cuttings for conveyance to the inboard side of the machine.
It is clear that the operation of the ram 100 upon the cross pin 108 will raise and lower the working tool 80 upon the pivot pin 96 to make slope adjustments, and the simultaneous operation of the rams 66 and 68 will raise the working tool 80 in a substantially vertical manner to make the grade adjustments.
The upright member 56 is provided with an extension 119 which carries the grade sensor 120 by means of the adjustable hand operated jack 122, upon the side bracket 124 which is also adjustable in relation to the jack. The grade sensor has its sensing arm 126 extending over and in light contact with the top of the grade line 114.
The extension 119 also provides support for the hand operated jack 128, supporting at its end the steering sensor 130. The pendent sensing arm 132 of the steering sensor 130 rides along the inside of the grade line 114.
The purpose of the jacks 122 and 128 is to provide initial manual adjustment of the sensors to bring them into proper position in relation to the grade line 114 while having the rams 66, 68 and 100 at about their mid-points of extension so that maximum travel in each direction is had.
As previously described, the machine is articulated at the center and steering is performed by the operation of the ram 34. This function is through the servo-valve 132 (FIG. 7) and hydraulic lines 134-136 in a manner known in the art. In FIG. 3 the steering function of the machine is shown during the step of negotiating a right turn as sensed by the steering sensor 130 to turn the front portion of the machine in the direction of the arrow C as the back portion of the machine is turned in the direction of the arrow B by the ram 34, with the machine traveling in the direction of the arrow 140.
In FIG. 4 the opposite steering function is being performed wherein the front of the machine is being turned in the direction of the arrow C and the back portion is being turned in the direction of the arrow B under the guidance of the steering sensor 130. In both of these maneuvers the primary swing of the frame parts is in the rear section 22 and the front section 12 remains on a practically straight path.
Referring to FIG. 5 a slope control adjustment is illustrated by the arrow S, being made by the extension of the ram 100 to pivot the tool 80 about the longitudinal axis 96. This function is under the control of the gravity operated slope sensor 142 located central of the frame 12 in a protected position (See FIG. 7) on the frame 12.
In FIG. 6 the machine is shown responding to a grade correction as sensed by the grade sensor 120 (not shown), wherein the rams 66 and 68 are operated simultaneously to lower the arms 58 and 60, the tool support unit 50, along with the tool 80, in making a grade adjustment indicated by the arrow G. It is to be noted that the lower forward edge of the housing 80 is beveled at 144 so that it will not dig into the grade during normal grade adjustments.
FIG. 7 illustrates the general geometry of the tool suspension system along with some of the parts for control of the servo-hydraulic system. The engine 146 drives the pump 150 and provides high pressure oil in the line 152 from the supply tank 154, inlet line 156, connected through a filter and return line 158 via the cooler 160. The high pressure oil line 152 leads to the branch line 162 and the solenoid valve 164 supplying the servo-valve 132. A second branch line 166 leads back through the solenoid valve 168 to the supply tank 154.
It is apparent that the grade sensor 120 and the steering sensor 130 are suitably connected electrically from the battery 170 through the amplifier 172 for control of the servo-valve 132 whereby those portions of the valve 132 are activated to accomplish, respectively, a grade correction by means of the simultaneous operation of the pair of rams 66 and 68 through the pairs of hydraulic lines 174-176 connected by branch lines to the top and bottom of the cylinders of their rams and a slope correction by means of the operation of the ram 100 through the hydraulic lines 178-180.
The pump 150 also supplies high pressure oil through the line 182 to the motor 184 to drive the cutter, and the return line 186 conveys the oil from this motor back to the supply 154. The valve 188 controls the speed of the motor 184 while the valve 190 is the main control valve for all of the hydraulic systems. The main electrical switch for the grade, slope and steering controls is illustrated at 192. The connections for the slope control 142 to the servo-valve 132 are not shown.
In FIG. 7 the geometric relationship of the rams 66 and 68 and the ram 100 to each other and to the tool support 50 and pivots 62-64 is an important consideration as concerns the accuracy and sensitivity of the slope and grade adjustments. The rams 66-68 are located sufficiently ahead of the mid-point between the center line of the pivots 62-64 and behind the center line of the tool so that the upward thrust during working and downward weight of the tool 80 are suitably balanced and the tool in a sense floats along as the machine progresses, there being very little actual working forces on these rams during operation. Similarly the ram 100 in addition to being central of the rams 66-68 and ahead of them is at approximately the central balance point of the tool 80 thereby reducing the lateral thrusts that would otherwise be placed upon the longitudinal end pivot 96 or the central pivot 104. During operation the tool 80 practically floats on the pivot 104.
During the operation of the machine the tool 80 tends to maintain the front frame portion 12 in its transverse position along the path of travel, indicated by the arrow 140. When a steering correction is called for by the steering sensor 130 and the ram 34 extends, for example, to make a right hand correction, the rear section 22 of the frame tends to move outwardly from the string line, more than the front section 12 of the machine moves inwardly, or to the right. This is due to the resistance of the tool 80 against twisting in its horizontal plane because of contact with the grade. The reverse action is the same for a left hand steering correction.
Consequently a relatively greater ram movement to accomplish a given steering correction is necessary with the working tool suspended in this manner across the front of an articulated frame than would be required with no tool on the machine. A decided advantage results in that a very small movement of the ram 34 can accomplish a finite direction adjustment within the sensitivity of the steering sensor which can be used to its ultimate capacity without lag or hunting in the system.
The tool naturally offers greater resistance to the hydraulic rams 66 and 68 in making a downward correction (extending) than in making an upward correction (retracting) but the slope adjustments, accomplished by the ram 100 are practically unimpeded in either direction. The extension of the rams 66 and 68 tends to either lower the tool 80 or raise the front wheels 40 from the grade. Since the weight of the machine is far greater than the downward thrust necessary to cause the tool to dig deeper in making a grade adjustment, the geometry of the placement of the rams 66-68 ahead of the axles for the front wheels comes into play by giving the side beams 58 and 60 less lifting leverage than lowering leverage. | 4y
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The Government has rights in this invention pursuant to a contract awarded by the Department of the Air Force.
TECHNICAL FIELD
The invention relates to nozzles carrying high temperature gas and in particular to retention of a liner therein.
BACKGROUND OF THE INVENTION
Nozzles of gas turbine engines carry extremely hot exhaust gas. It is therefore necessary to provide liners which protect the underlying structure. These liners are conventionally air cooled, usually with an impingement plate located adjacent the liners with cooling air passing through holes in the impingement plate and impinging against the liner. Such airflow then passes out through the aft end of the liner convectively cooling hot surfaces as it traverses aft.
These liners must furthermore be supported in such a way as to permit expansion relative to the support structure because of the temperature differential.
Even with the appropriate cooling construction these liners still deteriorate and must be replaced. Previous methods of retaining the liners produce difficult installation and replacement problems.
Fasteners previously used required welding. They also frequently required covering of the fasteners. This tended to lead to disturbances of the aerodynamic contour. They were also very difficult to remove for replacement of the liner.
SUMMARY OF THE INVENTION
The liner to be held against the impingement plate is a flexible liner with a plurality of arcuate portions and an axially extending linear portion between the arcuate portions.
On the linear portion there are a plurality of clips which interact with engageable clips on the impingement plate. These are sized and spaced such that the liner may be placed over the impingement plate axially misaligned with the clips passing by each other at that point, and with the liner being slid axially with all the clips in engagement. The liner must then be axially restrained.
A fixed stop, preferably on the impingement plate engages one side of a clip which is on the liner. A second side of this clip is engaged with a depressible spring preferably also located on the impingement plate. This is preferably a cantilever spring with the edge in abutment with the clip.
The closable opening is provided in the liner adjacent the spring which permits inspection to determine that the spring is engaged, and also permits access for removal. This opening is preferably closed with a rivet to eliminate air leakage.
It is also preferable that both the stop and the spring operate on the same clip whereby expansion of the liner may take place away from the two holding points. This permits relatively close tolerance on the clearance at the spring and stop locations.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a section showing a liner, the impingement plate and the clips;
FIG. 2 is a top view showing a relative position of the clip portions;
FIG. 3 is a side view of the liner retainer;
FIG. 4 is a section through the retainer without the liner; and
FIG. 5 is a section through the retainer with the liner.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1 there is shown a nozzle support structure 10 with a planar impingement plate 12. Liner 14 has a plurality of arcuate sections 16 with axially extending linear portions 18 located between the arcuate portions. Airflow openings 20 located in the impingement plate direct cooling air against the liner 16 with this air convectively cooling the liner as it passes aft and out the end.
Interlocking clip pairs 22 are each comprised of a first clip 24 located on the linear portion of the liner and a second clip 26 located on the impingement plate. FIG. 2 is a top view of the assembly with liner 16 removed. Clips 24 secured to the liner are, however, shown in one portion of the drawing to illustrate their relationship to clips 26. Clips 26 located on impingement plate 20 are spaced and have a tapered edge 28 to facilitate assembly with clips 24. A flat bar 30 extends substantially the length of the liner with clips 24 extending therefrom at spaced locations. These clips 24 engage corresponding clips 26 as shown. For installation the clips (24 and 26) are placed out of engagement, the surface is pressed together, and the liner slid axially for engagement as shown. Cantilever spring 32 retains the liner in position as described in more detail hereinafter. It is noted, however, that this retainer spring 32 need not be located with every bar 30 and preferably is at two or three locations.
Referring to FIG. 3 an optional spring travel retainer 34 is shown. This limits the travel of the spring beyond its uncompressed condition as shown and the fully required depressed condition against the impingement plate. The travel limiter 34 must be located at such a point that it does not interfere with axial travel of clip 24 on liner 14.
The liner 14 is placed with the clips (24 and 26) out of engagement as described above and slid into place. Clip 24 engages stop 36 located on impingement plate 12 which limits and retains axial motion in a first direction. Spring 32 which has been depressed below clip 24 for initial installation springs upwardly and abuts the end of clip 24 to prevent axial travel in the other direction. This functions to retain the liner against axial movement while the opposite end of the liner is free to expand as required.
An opening 38 in the liner permits inspection to determine that the spring is released and engaged. It also provides access for depressing the spring for later disassembly and removal of the liner. A rivet 40 or any other appropriate closing means may be used to close this hole against air leakage during operation.
FIG. 4 illustrates in more detail the spring arrangement with the liner omitted. Clip 26 secured to liner 12 can be seen with the leading edge 28 tapered. The spring travel retainer is omitted in this view. Stop 36 is brazed, and may be bolted to the planar impingement plate 12.
FIG. 5 is similar to FIG. 4, but illustrates the liner in place with clip 24 abutting stop 36. Spring 32 abuts or is closely spaced from clip 24. The clearance between the spring and the clip 24 plus the clearance between the clip 24 and the stop is nominally on the order of 0.030 inches (0.762 mm). Access opening 38 is shown in the liner.
Thus, there is provided an apparatus for retaining the liner wherein the liner is easy to install and also easy to remove when required. There is no interference with either the cooling airflow or the gas flow passing through the nozzle. It eliminates access cover plates and eliminates welding and fitting. It provides a means for inspecting for positive engagement of the stop. | 4y
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[0001] This invention relates to a brush-type mat with lengths of fibrous materials embedded in and extending up from a base layer of plastic, in which that base layer is essentially formed of a particular combination of biodegradable plastics, the mat having superior physical and chemical characteristics, and to a particularly advantageous method of forming the base layer.
BACKGROUND OF THE INVENTION
[0002] Brush-type mats are well known, and are often used as doormats. They consist of a base layer of plastic into which are embedded the ends of tufts of fibrous material, portions of these tufts extending up from the base layer. Since such mats are generally used in applications where they are subjected to extremely rigorous conditions, and therefore must be capable of withstanding these conditions. Accordingly, in the past, the base layer has usually been constituted of a cured plastic having appropriate physical and chemical characteristics, usually polyvinyl chloride or comparable material, into which the lengths of the fabric material forming the tufted portion of the mat are embedded. Those plastic materials, while generally satisfactory in terms of use, have a significant drawback which has recently become relatively critical, to wit, they are not biodegradable. Since mats of the type under discussion have only a finite life and will be discarded at some time, the non-biodegradability of the plastics used in them has become a serious drawback, particularly in view of the increased consciousness on the part of the public of the need for biodegradability. Non-biodegradable curable plastics are, of course, known, but their use in mats of the type under discussion has been contra-indicated because they have not in the past produced mats of adequate physical characteristics, in particular being deficient in the strength with which the tufted lengths of fibrous materials are reliably retained within the plastic layer and the resistance of the mats to tearing or the like.
SUMMARY OF THE INVENTION
[0003] In accordance with the present invention, the layer which forms the base of the mat is constituted by a layer of biodegradable plastic material made up largely of rubber, the rubber being provided in a compounded form which in the end product produces physical characteristics, particularly including strength, equal or superior to the strength of the polyvinyl chloride which has previously largely been used for mats. In addition, the essentially rubber compositions used to constitute the layer of the present invention are significantly superior to other latex formulations in terms of shelf life, a very important manufacturing consideration.
[0004] These results are accomplished by first forming two different latex mixtures which have comparatively long shelf lives and then combining them to produce a relatively short shelf life combination which can readily be formed into a layer into which the coir or other fibrous materials may be inserted to produce the desired mat when the layer with the fibrous materials embedded and projecting therefrom is cured. One mixture comprises natural rubber latex and an accelerator and the other mixture comprises synthetic rubber latex, a filler and an accelerator.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The drawing is a schematic representation of the equipment used to form the mats of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0006] The drawing discloses a preferred embodiment of the apparatus to produce the mat of the present invention. The fibrous materials generally designated 2 which will form the tufts of the mat are preferably constituted by coir yarn, the fibers being extracted from the husks of coconuts, cleaned and then spun by hand or machine to form yarn. The yarn is provided in a plurality of rolls 4 . Many lengths of yarn 2 are unwound from the equally numerous rolls 4 and fed over rollers 6 to an assembly station 8 of known construction and operation, the continuous yarn lengths 2 at this assembly station 8 being cut into short lengths which eventually become the tufts of the mat.
[0007] A part of the assembly station 8 is the latex feeding mechanism, generally designated 10 , which pumps latex from a container 12 onto a continuous teflon belt 14 to form a layer of latex thereon. The belt 14 , which moves from left to right as viewed in the drawing, carries that layer beneath the assembly station 8 . The layer on the belt 14 will have a appreciable thickness such as 4-8 mm depending on the desired pulling strength and pile height of the end product. In the assembly station 8 the fibrous material 2 is fed therethrough and cut into short lengths the size of which is determined by the desired thickness on the mat to be produced. The short lengths of fibrous materials are, at the assembly station 8 , oriented vertically and pushed down so that their lower ends become embedded in the plastic layer. In this way, a continuous embryonic mat is produced consisting of a continuous layer of uncured latex and a substantially continuous series of tufts of fibrous materials extending up therefrom. That embryonic mat is then subjected to a treatment such as heating in order to cure the latex and thus produce the finished product. To that end, the latex layer with the tufts of fibrous material extending up therefrom is fed from the belt 14 into a curing enclosure generally designated 16 in which a continuous belt 18 receives the layer and tufts and moves it through the heating enclosure 16 , which is elongated so that the layer with the fibrous material extending up therefrom is subjected to heat for a long enough period to cure the layer. The heat enclosure 16 preferably comprises a hot air chamber in which the air in the chamber is maintained at an appropriate curing temperature for an appropriate period of time, such as 90° centigrade for 45 minutes. It is preferred to have heating elements both above and below the layer tuft assembly throughout substantially the entire length of the heating enclosure 16 The finally cured continuous mat 22 is moved out from the heating chamber 16 and wound on a reel 24 , ready for cutting and shearing as is conventional.
[0008] It is most desirable to form a biodegradable latex layer of appropriate characteristics, particularly one having structural strength and strongly retaining the tufts of fibrous material, while at the same time utilizing materials which have a shelf life of many days, so that they are adaptable to economic industrial use. To that end, and in accordance with the present invention, the material to be stored in the container 12 and pumped onto the belt 14 to produce the latex layer is formed of two initially separate mixtures. Each of those mixtures has an appreciable shelf life. These two mixtures may therefore be produced and stored in the plant for appreciable periods of time without any deterioration However, neither of them are themselves capable of forming a commercially adequate layer for receiving the fibrous tufts When these two mixtures are combined, the resultant combination has a relatively short shelf life, but the two mixtures will be combined only when the layer is to be formed In this way, mats may be formed which are comparable or superior to mats using polyvinyl chloride but which, unlike the polyvinyl chloride mats, are biodegradable. These two original mixtures will, for purposes of description, be designated mixture A and mixture B.
[0009] Mixture A comprises natural rubber latex and an accelerator. Mixture B comprises synthetic rubber latex, preferably styrene butadiene rubber latex (SBR), a filler, preferably dolomite powder, and an accelerator. The same accelerator may be used in both mixtures if desired. The accelerator is preferably zinc diethyl dithiocarbamate (ZDC). Zinc oxide and sulphur and other conventional chemicals and coloring agents may also be included. Mixture A, before it is combined with mixture B to be used to form a mat, requires maturation before it is ready for use. That is preferably accomplished by keeping the mixture in a room without sunlight at a temperature of 25-30° C. for a period of 3-5 days. When it is matured it should preferably be used within 20 days, which is a comparatively long shelf life. Mixture B can be used as mixed, without maturation, and has a shelf life well in excess of 20 days. When mixture A and mixture B are combined the resultant combination has a shelf life which is much shorter than that of either of mixtures A or B, but since the combination can be formed only when needed for manufacturing its shelf life is quite adequate
[0010] The use of ZDC as an accelerator is highly preferred, but up to 50% of that ZDC can be substituted for by the zinc salt of mercaptobenzthiazole (ZMBT). The preferred SBR is that sold by Powerene under the designation PLX-802
[0011] Two preferred recipes from mixtures A and B are set forth below, but it will be understood that the relative proportions may be varied depending upon the characteristics and conditions of the lattices involved. In particular, the proportions of the chemicals added to the natural latex in mixture A may vary up to plus or minus 10% depending upon the quality and age of the latex received.
[0012] In addition, the relative proportions of mixtures A and B, which in the disclosed recipes extend over a ratio range of from 1:1.5 to 1:1.29, these being parts by weight of mixture B to mixture A, might also be varied by plus or minus 10%.
Recipe- Recipe-1 Recipe-2 Recipe-1 2 Mixture A 60% LATEX 100.00 KGS 100.00 KGS 220.00 LBS 220.00 LBS 50% ZDC 1.80 KGS 1.80 KGS 4.00 LBS 4.00 DISPER- LBS SION 50% SUL- 1.80 KGS 1.80 KGS 4.00 LBS 4.00 PHUR LBS 50% ZINC 0.96 KGS 0.96 KGS 2.10 LBS 2.10 OXIDE LBS Mixture B DOLOMITE 60.00 KGS 60.00 KGS 132.00 LBS 132.00 POWDER LBS SBR LA- 30.00 KGS 20.00 KGS 66.00 LBS 44.00 TEX (PLX- LBS 802) 50% ZDC 0.15 KGS 0.10 KGS 0.33 LBS 0.22 DISPER- LBS SION 50% SUL- 0.30 KGS 0.20 KGS 0.66 LBS 0.44 PHUR LBS 50% ZINC 0.90 KGS 0.60 KGS 1.98 LBS 1.32 OXIDE LBS
[0013] Through the use of separate mixtures of natural rubber latex and styrene butadiene rubber latex, each of which has a shelf life satisfactory for storage in connection with an industrial process, and combining of those two mixtures at the time of use in order to produce a plastic layer into which tufts of fibrous material may be inserted, the layer-fiber combination thereafter being cured, a tufted mat is produced which can compete in strength with mats made with polyvinyl chloride as the plastic but which, unlike the polyvinyl chloride mats, has the very desirable characteristic of being biodegradable.
[0014] While preferred embodiments in the present invention have been here disclosed, it will be apparent that variations may be made therein, all within the scope of the present invention as defined in the following claims: | 4y
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BACKGROUND
[0001] 1. Field of the Invention
[0002] This invention relates to a device and method using infrared to enhance selective catalytic reduction (SCR) of NOx, consisting of at least an infrared-emitting body, said infrared-emitting body being engineered to have specific spectral luminance covering a part or the whole of 3-14 μm wavelength range, that provides an effective means for improving NOx conversion in the SCR aftertreatment system of diesel engines.
[0003] 2. Description of Prior Art
[0004] The combustion of fossil fuel always leads to the formation of nitrogen oxides (NOx). NOx formation mechanisms in internal combustion engines are well known and details published in textbooks. The term “NOx” is used primarily to describe two species: nitric oxide (NO) and nitrogen oxide (NO 2 ). Sometimes the term is extended to include other oxides such as a nitrous oxide (NO 2 ), which is insignificant and often ignored.
[0005] The most desirable removal mechanism would be direct decomposition of NOx. The selective catalytic reduction (SCR) is a validated technology for the removal of NOx in diesel exhaust. There are commercial exhaust aftertreatment systems that employ intentional injection of some reducing agent into the exhaust gas. This is called “active deNOx”. The reducing agent is usually ammonia or urea, while some researchers are pursuing methods using hydrocarbons as reducing agent.
[0006] The strategy of urea-SCR is to set free NH 3 from urea, CO(NH 2 ) 2 , by thermolysis and hydrolysis as given in the chemical equation (1):
[0000] CO(NH 2 ) 2 →HNCO+NH 3 . . . (by thermolysis)
[0000] HNCO→NH 3 +CO 2 . . . (by hydrolysis) (1)
[0000] The NH 3 radical then reacts with NO and NO 2 as depicted in chemical equations (2) and (3):
[0000] 6NO+4NH 3 →5N 2 +6H 2 O (2)
[0000] 6NO 2 +8NH 3 →7N 2 +12H 2 O (3)
[0000] An undesired byproduct, such as biuret (NH 2 CONHCONH 2 ), can be produced if urea solution is not properly thermolyzed or hydrolyzed.
[0007] An alternative method is the use of a light hydrocarbon, such as propylene, propane, or methane as a reluctant during the selective catalytic reduction of NOx (HC—SCR). As such, hydrocarbons can be provided from the fuel source, thus adding no new storage, transportation or corrosion concerns. For example, the propylene C 3 H 6 reacts with NO in the way as described in chemical equation (4)
[0000] 2C 3 H 6 +18NO→9N 2 +6H 2 O+6CO 2 (4)
[0000] The present inventor had realized the scientific fact that hydrocarbons are “infrared-active” and absorb infrared photons shorter than 20 μm in wavelengths causing vibrations, which resulted in the inventions of fuel combustion enhancement devices as described in U.S. Pat. Nos. 6,026,788 and 6,082,339 (by the present inventor). Quantum Mechanically speaking, infrared-excited hydrocarbon molecules have lower activation barriers and thus get higher chemical reaction rates. The present inventor had developed several infrared-emitting bodies in 3-14 μm wavelengths, which are categorized as “mid-infrared” in NASA definition but “far-infrared” in Japanese convention. The present inventor was able to use the IR-emitters to validate underlying science of infrared-excitation in Methane-Air Counterflow Flame experiments. Infrared was found helping improve 6 % combustion efficiency in combustion of methane-air mixture as described in reaction (5).
[0000] CH 4 +O 2 →CO+H 2 +H 2 O
[0000] furthermore H 2 +½O 2 →H 2 O
[0000] CO+½O 2 →CO 2 (5)
[0008] In real diesel engine applications, the present inventor discovered experimentally that such IR-emitters could also enhance the reduction reaction described in equation (4) for removal of NOx. Through literature search, the present inventor further realized that the bonds in urea and ammonia molecules, including N—H, —NH 2 , —CONH—, and —CONH 2 , also absorb infrared in 3-14 μm wavelengths to cause molecular excitations. In other words, urea and ammonia are so-called “infrared-active”.
[0009] For example, —HNCO—bond vibrates at 3.23-3.26 and 6.45-6.62 μm bands, while the —NH 2 bonds absorb photons at 3.029 μm, 3.106 μm, and 6.680 μm wavelengths to respectively cause symmetric, asymmetric, and bending vibrations. The vibrational modes also include overtones at bands 4.52-4.72, 6.58-6.76, 9.57-9.85, 11.90-12.50, and 12.20-12.99 μm, which all fall in said 3-14 μm wavelength range. It became evident that infrared can help enhancing urea-SCR reaction in equations (1), (2), and (3), and HC—SCR in equation (4), because all reactants in the equation are all infrared-active. Besides, the bonds of biuret (NH 2 CONHCONH 2 ) are found to vibrate at 4.72-4.93 and 6.80-6.92 μm bands so that infrared excitation may raise reduction of biuret and limit its production in the processes.
[0010] As previously mentioned, the present inventor had discovered the use of infrared in 3-14 μm wavelengths for improving combustion efficiency of hydrocarbon fuel in internal combustion engines as disclosed in U.S. Pat. Nos. 6,026,788 and 6,082,339 by the present inventor. Since then, a number of similar inventions had followed, for examples U.S. Pat. Nos. 7,021,297, 7,036,492, and 7,281,526, just to name a few. Even so, the prior arts only described the use of infrareds in oxidation of hydrocarbons and failed to teach the use of infrareds for aiding selective catalytic reduction (SCR) of NOx using urea, ammonia, and hydrocarbons as reducing agents in diesel applications.
Objects and Advantages
[0011] Accordingly, one object of this invention is to provide a device and method that can increase the efficiency of a selective catalytic reduction (SCR) of NOx aftertreatment using urea, ammonia, hydrocarbons, or other infrared-active substances as reducing agent(s).
[0012] Another object of the present invention is to provide a simple, easy-to-implement, and maintenance-free infrared-enhanced SCR of NOx device.
[0013] These objectives are achieved by an infrared-enhanced SCR device comprising essentially at least one infrared emitting body having specific spectral luminance covering a part or whole of 3-14 μm wavelength range. The device can be disposed in the delivery system of reducing agent for said SCR system to excite the reluctant before it mixes with exhausts gas for reduction of NOx.
[0014] Other objects, features and advantages of the present invention will hereinafter become apparent to those skilled in the art from the following description.
DRAWINGS FIGURES
[0015] FIG. 1 shows a cross-sectional view of one embodiment of the present invention with a tubular infrared-emitting body implemented as a part of nozzle assembly.
[0016] FIG. 2 shows a cross-sectional view of another embodiment of the present invention with an infrared emitting body in partial-tubular form and being mounted on a supply hose.
REFERENCE NUMERALS IN THE DRAWINGS
[0000]
11 Infrared emitting body
21 Nozzle assembly
22 Supply hose
SUMMARY
[0020] In accordance with the present invention an infrared-enhanced selective catalytic reduction (SCR) of NOx aftertreatment device and method consists of at least an infrared emitting body having specific spectral luminance covering a part or the whole of 3-14 μm wavelength range. It can enhance NOx conversion efficiency of said SCR system, resulting in reduced NOx in exhaust. The infrared emitting body can be disposed in the passageway of reducing agent for said SCR aftertreatment to energize the reluctant before it mixes with exhaust gas for NOx reduction.
DETAILED DESCRIPTION OF THE INVENTION
[0021] It is well known that absorption of an infrared photon at a wavelength shorter than 20 μm (micrometer) gives rise to bond stretching or bending vibration in molecules that are “infrared-active”. In fact, Organic Chemists have been using IR absorption spectral analysis (so-called “Infrared Correlation Charts”) to identify unknown specimens for decades. Based on spectral absorption profiles in 3-7 μm (so-called “Functional Group” zone) and 7-20 μm (“Signature” zone) the test specimen can be precisely identified. However, what people had long ignored was absorbing IR photons can increase kinetic energy of covalent bonds and thus cause molecule to vibrate. It not only changes dipole moment of the molecule, but also decreases activation barrier of the bond and thus increases reaction chemical rate, which is described in equation (6) by Quantum Mechanics:
[0000] Reaction Rate: W=Ke −E/RT (6)
[0000] where K is a constant, E activation energy, and T temperature (in Kelvin). Equation (6) predicts an increased reaction rate W with a reduced activation energy E.
[0022] The present inventor had reported favorable results on using the devices as described in U.S. Pat. No. 6,026,788 to excite fuels for enhanced engine performance. The net results were improved fuel combustion efficiency with increased torque/power, reduced fuel consumption, and lowered emissions. In real diesel engine applications the present inventor recognized that the reducing agents such as urea, ammonia, or hydrocarbons used in commercial urea-SCR or HC—SCR aftertreatment systems for removal of NOx are all “infrared-active”. In urea and ammonia, bonds such as N—H, —NH 2 , and primary and secondary amide —CONH 2 show strong absorption for combination and overtone modes in 3-7 μm wavelengths (i.e. Zone I). There are other overtone bands in long wavelengths, but often too weak to be noticed.
[0023] The present inventor learned from Japanese published results and experimentally confirmed that adding cobalt oxide and/or nickel oxides to the oxide mixture as disclosed in U.S. Pat. No. 6,026,788 can boost the radiation strength at short wavelengths. Meanwhile, increasing ceramic processing temperature from a conventional 1200° C. to above 1350° C. can further strengthen spectral luminance of the resultant IR-emitter at short wavelengths. Accordingly, several examples of the present invention were prepared for demonstration.
[0024] FIG. 1 shows a cross-sectional view of one embodiment of the present invention, in which an infrared-emitting body 11 takes a tubular form and is disposed as a part of the nozzle assembly 21 that is connected to a supply line 22 for injecting reducing agent into the SCR system. In this implementation the infrared-emitting body is in direct contact with reducing agent. By the same token, the infrared-emitting body can be immerged in the storage tank of the reducing agent as an alternative to provide infrared excitation.
[0025] FIG. 2 shows a cross-sectional view of another embodiment of the present invention, in which a partial-tubular infrared-emitting body 11 is mounted on a supply line 22 connecting to the nozzle assembly 21 . In this arrangement, the infrared-emitting body can be mounted on the exterior of a nonmetal section of the supply line for ease of implementation. Infrared photons can penetrate nonmetal hose and excite the substance flowing through the line. Such implementation does not require infrared-emitting body to directly contact reducing agent.
[0026] In other embodiments the infrared emitting bodies can be disposed in the interior of a supply line or nozzle assembly by embedding or coating on the inner wall, or being a part of the reducing agent delivery system.
EXAMPLES
[0027] Several demonstration samples were made with 40 (weight) % silicate, 25% alumina, 17% zirconia, 7% magnesium oxide, 5% cobalt oxide, and other minor elements and processed at a temperature above 1350° C. An SEM/EDS (scanning electron microscope with energy dispersive spectrometry) plot was run with the samples to obtain a quantitative analysis on the elemental composition of the oxide compounds. In lab, an infrared imaging camera with variable wavelength band filters was used to determine the spectral luminance for these IR-emitters. The IR-emitter was tested by mounting it on a Teflon fuel hose to an HC—SCR system with a zeolites catalyst. The preliminary test result seemed very encouraging, while further scientific investigation remained to be done.
Conclusion, Ramifications, and Scope
[0028] According to the present invention, an infrared-enhanced selective catalytic reduction (SCR) device comprises at least an infrared emitting body having specific spectral luminance covering a part or the whole of 3-14 μm wavelength range, which can be disposed in the passageway of the reducing-agent to said SCR system for better NOx conversion.
[0029] The invention has been described above. Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. Such variations are not to be regarded as a departure from the spirit and scope of the invention and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims. | 4y
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RELATED APPLICATIONS
This application is a continuation in part of Ser. No. 29/243,432 filed Nov. 23, 2005 entitled Bottom Feeding Hose Reel Enclosure with Wheels and a See Through Cover, Ser. No. 29/243,433 filed Nov. 23, 2005 entitled Bottom Feeding Hose Reel Enclosure With Wheels and Opaque Cover, Ser. No. 29/243,434 filed Nov. 23, 2005 entitled Bottom Feeding Hose Reel Enclosure with See-Through Cover, Ser. No. 29/243,435 filed Nov. 23, 2005 entitled Bottom Feeding Hose Reel Enclosure, Ser. No. 29/243,426 filed Nov. 23, 2005 entitled Ornamental Shape for a Hose Reel Enclosure with Wheels, Ser. No. 29/243,502 filed Nov. 23, 2005 entitled Ornamental Shape for a Hose Reel Enclosure with See-Through Cover, Ser. No. 29/243,503 filed Nov. 23, 2005 entitled Ornamental Shape for a Bottom Feeding Hose Reel Enclosure, the contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates generally to garden tools, and more specifically to a hose reel device having an entry point below the centerline of the reel for stability of the enclosure and a crank operation point at or above the centerline of the reel for ease of operation.
BACKGROUND OF THE INVENTION
Portable hose reel carts for handling and storage of flexible water hoses, such as garden and air hoses, have gained wide public acceptance. While the construction of hose reel carts is quite varied, such carts are primarily constructed of molded plastic components having a centrally disposed rotatable spool for reeling of the flexible hose, a frame for supporting of the spool, wheels may be included at one end of the base of the frame, and a frame handle for tilting the frame onto the wheels to facilitate moving the cart. The frame handle may, or may not be foldable or telescoping for purposes of shipping and/or storage. For more information concerning the structure and operation of hose reel carts, reference may be made to U.S. Pat. RE. 32,510, and U.S. Pat. No. 5,998,552 the teachings of which are hereby incorporated by reference.
Common to hose reel carts is the use of a crank handle secured to a hub for use in rotation of a spool. The spools are typically arranged with the crank handle located at the center of the hub to wind the flexible hose. Attempts have been made to move the location of the crank handle, however, such attempts typically employ the use of a sprocket and chain assembly leaving little in the way of efficiency, ratio gearing, or the ability to compactly store such a device. The advantage of an elevated crank handle is to allow rotation of the spool by an operator who need not bend over to perform the operation. Standing upright lessens the strain on an individual's back, but typically crank movement does not address the change in location for gearing leverage, or address storage of such a device.
For instance, U.S. Pat. No. 1,115,325 discloses a garden hose reel storage device wherein the spool is rotated from a crank mounted a distance above the spool. The remotely mounted crank is coupled by a chain extending between a pair of sprockets for driving the spool. A smaller sprocket secured to the crank provides a gear reduction to the larger sprocket adjacent to the spool. The direct coupling requires a large diameter spool sprocket that is difficult to shield and creates dangerous pinch points.
U.S. Pat. No. 5,388,609 discloses a hose reel cart having a remotely mounted crank handle coupled to a spool by a chain and sprocket assembly. This disclosure utilizes an oversize crank handle thereby reducing the size of sprockets needed to transfer rotation from the hand crank to the hose reel spool.
U.S. Pat. No. 4,947,627 discloses a hose reel cart employing yet another sprocket and chain drive assembly. In this disclosure a crank sprocket is mounted along a side wall of the cart, at a slightly elevated position. The hand crank remains well below the cart handle. Thus, the device fails to take advantage of the highest point on the cart and continues to force the operator to crank the spool from a lower position.
U.S. Pat. Nos. 6,742,740, 6,908,058 and 6,976,649, assigned to same assignee as the instant invention, disclose hose carts with elevated cranking positions. These devices all utilize various combinations of intermeshing gears to transmit power between the crank, the reel and/or the level-wind device. However, one shortcoming with these devices is the elevated point from which the hose is recoiled onto the reel. The elevated recoil position may increase the likelihood of overturning the device during hose rewinding.
U.S. Pat. No. 5,404,900, assigned to the same assignee as the instant invention, discloses a hose enclosure with a level-wind apparatus for distributing the hose in an even manner across the face of a reel.
Thus, what is lacking in the art is a hose reel device having an elevated crank handle and a low-entry area for recoiling the hose. Also what is lacking in the art is a hose reel enclosure that includes a combination of injection molded and extruded panels for a low-cost yet robust enclosure. Prior art assemblies that utilize extruded panels require separate connectors to attach the panels together, increasing the number of components and connections required to assemble an enclosure, thereby increasing the complexity an cost of assembly. The hose reel device should include intermeshing gear drives for transfer of motion from the crank to the reel and/or level-wind components.
SUMMARY OF THE INVENTION
Among the several aspects and features of the present invention may be noted the provision of an improved portable hose reel cart having a low-entry point for recoiling a hose and an elevated hand crank for use in rotation of the reel spool. In an additional embodiment, the elevated hand crank is also used for movement of a level-wind hose guide for positioning of the flexible hose around the hose reel spool.
The hose reel cart of the present invention is of a shape and design so that the hose reel cart may be preassembled at the factory, thereby eliminating the need for assembly and associated product packaging. Preassembly of the hose reel cart permits the use of an enclosed construction for support of a hose to be wound into a coil of multiple layers with adjacent turns of each layer touching each other by use of a directional spool rotatably coupled to the enclosure. The hose is wound around the spool by use of a remotely located crank providing an direct or indirect rotational link between the crank and the winding of the spool. In the preferred embodiment, the crank is positioned in an upper portion of the enclosure assembly to allow for operation of the device with minimal bending or stooping. A hand-grip on the crank can also be placed in a storage position by pivoting the hand-grip about one end of the crank arm. The hand-grip has a releasable lock for securing the hand-grip in a parallel position with the crank arm for storage, and securing the crank hand-grip in a perpendicular position with respect to the crank arm for operation. In addition to providing the appropriate spacing, the intermeshing gears connect the crank to the reel and the optional level-wind components.
The instant invention utilizes a combination of injection molded and extruded panels to create a low-cost yet robust enclosure. Combining injection molded panels with extruded panels facilitates reducing the number of components required to assemble an enclosure when compared to enclosures comprised entirely of extruded panels. Injection molding facilitates integral formation of various connectors about the panel. The integrally formed connectors facilitate connecting the injection molded panel to extruded panels, blow molded panels and injection molded panels, eliminating the separate connectors required by the prior art devices.
Thus, an objective of the instant invention is to provide a portable hose reel enclosure having an elevated crank handle and a low-point of entry for retraction of a hose.
Another objective of the instant invention is to disclose a hose reel enclosure that includes injection molded as well as extruded panels to provide a lightweight yet robust enclosure assembly.
Yet another objective of the invention is to provide a portable hose reel cart having an elevated crank handle that can position a hose guide in addition to providing rotation to the hose reel hub.
Still another objective of the instant invention is to teach a combination of injection molded and extruded panels wherein connectors are integrally formed onto the edges of injection molded panels for connection to extruded and/or blow molded panels.
Still yet another objective of the instant invention is to provide an enclosure assembly which reduces the number of components required to assemble an enclosure to simplify construction.
A further objective of the instant invention is to provide a hose reel enclosure having a structural lid member having a lid strap for lid retention.
Other objectives and advantages of this invention will become apparent from the following description taken in conjunction with the accompanying drawings wherein are set forth, by way of illustration and example, certain embodiments of this invention. The drawings constitute a part of the specification and include exemplary embodiments of the present invention and illustrate various objectives and features thereof.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 is a front perspective view illustrating a hose reel apparatus constructed with the teachings of the present invention;
FIG. 2 is a rear perspective view illustrating a hose reel apparatus constructed with the teachings of the present invention;
FIG. 3 is a front perspective view illustrating a the lid member of the enclosure in an open position;
FIG. 4 is a partial perspective view illustrating a gearbox and a level-wind assembly constructed with the teachings of the present invention;
FIG. 5 is a partial perspective view illustrating a gear-train constructed with the teachings of the present invention;
FIG. 6 is an exploded perspective view illustrating integrally formed bearing surfaces constructed with the teachings of the present invention;
FIG. 7 is a rear perspective view of the front panel constructed with the teachings of the instant invention;
FIG. 8 is a perspective view of one embodiment of a reel suitable for use in the instant invention.
DETAILED DESCRIPTION OF THE INVENTION
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 embodiments illustrated.
Referring generally to the Figures, a hose reel apparatus 10 having an elevated point of operation and a low-entry point for hose retrieval is illustrated. The hose reel apparatus of the preferred embodiment includes an enclosure assembly 12 , a spool assembly 14 , a level-wind assembly 16 , a first gear train 18 , a second gear train 20 , and a crank assembly 22 .
The enclosure assembly includes a pair of side panels 24 secured in a substantially parallel arrangement. A front panel 26 extends between the side panels 24 at a front portion thereof to enclose the front portion of the enclosure and a rear panel 28 extends between the side panels at a rear portion thereof to enclose the rear portion of the enclosure. A lid member 30 encloses the top portion of the enclosure. In the preferred embodiment, the side members, front panel and lid member are formed by the process of injection molding to include integral connectors, ribs 46 and gussets 48 . The side panels 24 include integrally formed first connectors 32 along one edge thereof and integrally formed second connectors 34 along a second opposite edge thereof. The first connectors 32 are illustrated herein as at least one outwardly extending locking post 34 being constructed and arranged to cooperate in an interlocking manner with at least one inwardly extending socket 36 positioned along the edges of the front panel for interlocking cooperation therebetween. The locking posts 34 are constructed and arranged to cooperate with the front panel for connecting and maintaining a substantially perpendicular relationship between the front and side panel members. It should also be noted that while the locking posts are illustrated as being rectangular in shape when viewed from the end, other shapes suitable for locating and securing panels together may be utilized without departing from the scope of the invention. In a most preferred embodiment, each locking post 34 includes at least one detent or spring lock fastener 38 integrally formed thereto. The spring lock is constructed and arranged to cooperate with a catch surface 40 positioned within each socket for snap-together interlocking engagement. Those skilled in the art will appreciate that the snap-type fasteners 38 can be used throughout the hose reel device 10 to mount or secure components to one another, and to facilitate ready assembly of the cart if it is provided in an unassembled manner.
Referring to FIGS. 2 and 4 , the second connectors 34 are illustrated herein as two spaced apart substantially parallel surfaces 42 extending outwardly from an end surface 44 forming a U-shape for connection to an adjacently positioned extruded or blow molded rear panel 28 . In a most preferred embodiment, at least one of the parallel surfaces include a spring lock fastener integrally formed thereto for cooperation with a catch surface positioned in the rear panel.
It should be noted that while the locking posts are illustrated as formed on the edges of the side panels, the locking bosses may be formed on the edges of the front or rear panel and the sockets formed into the side panels without departing from the scope of the invention.
Referring to FIGS. 1-3 , the lid member is illustrated. The lid member includes a bottom surface 50 constructed and arranged to cooperate with the front panel, the rear panel and the side wall members in a closed position to maintain a weather-tight enclosure. The bottom surface 50 illustrates the ribs 46 and gussets 48 facilitated by injection molding of panels. In addition to the strengthening ribs 46 , the bottom surface of the lid member includes a depending lip 51 extending around the perimeter of the lid and a hinge means integrally formed to a rear portion thereof. The hinge means is illustrated herein as a pair of depending C-shaped members 52 and loop shaped receivers 54 . A latch means 56 is integrally formed to a front portion of the lid member for releasably securing the cover to the front panel. The latch means is illustrated herein as a depending spring-lock 58 that is constructed and arranged to cooperate with apertures 60 positioned in the upper edge of the front panel. It should be noted that other latch means well known in the art may be utilized without departing from the scope of the invention. In operation, when the lid is opened a portion of the depending lip 51 pivots to engage an inwardly extending recess 53 . The engagement between the depending lip 51 and the recess 53 control the rotation of the lid and prevent the lid prevent from being removed from the enclosure. Strap 47 may also be provided to control rotation of the lid and further tie the lid to the enclosure. Integrally formed mounts 49 allow the ends of the strap 47 to be snapped into engagement with the lid and the side panel.
Injection molding of the panel members offers significant strength, stability and versatility advantages over blow-molding, extrusion or vacuum molding as utilized in the prior art. Injection molding facilitates forming thicker and/or thinner portions within the same panel for areas of high or low stress concentrations such as is required with the first and second connectors to facilitate connection to panels manufactured by different methods. It should also be appreciated that the injection molded panels of the instant invention only require a single wall construction, while the extruded or blow molded panels may include two or more walls integrally connected together. It should also be noted that while only the rear panel is illustrated as being an extruded panel, the first and second connectors may be formed along the edges of any injection molded panel, used in construction of the enclosure, for cooperation with an adjacently positioned extruded or blow molded panel. In this manner, an enclosure comprising various combinations of extruded, injection molded and blow molded panels may be constructed for economy, strength and durability.
Referring to FIG. 8 , a rotatable reel assembly suitable for use with the teachings of the instant invention is illustrated. The rotatable reel assembly 14 is operably connected between the side panels 24 for rotation about an axis of rotation A ( FIG. 4 ). The rotatable reel 14 provides for pick-up, storage and pay-out of an elongated hose member. The spool 14 includes a central hub 62 and a pair of radially extending flanges 64 that are configured to accommodate a length of flexible hose wrapped around the hub 62 between the flanges 64 . In a typical arrangement, the hose reel apparatus 10 may store between 50 to 300 feet of a ⅝ inch common hose. Those skilled in the art will recognize that the hose reel apparatus 10 may include a water/air inlet port or in-tube 66 ( FIG. 2 ) and an outlet port or out-tube (not shown). Typically the in-tube is mounted to the side panel 24 at about the axis of rotation A of the spool 14 . The in-tube is connected to the out-tube by a sliding seal arrangement (not shown) so that the in-tube remains fixed to the side panel 24 , while the out-tube rotates with the spool 14 , and the in-tube and out-tube remain in fluid communication with one another. This arrangement permits rotation of the spool 14 without twisting or torquing internal components, while maintaining sealed fluid communication between the water/air supply and the hose. The preferred in-tube and coupling arrangement can be viewed in U.S. Pat. No. 5,998,552, the contents of which are incorporated herein by reference.
Referring to FIGS. 1 , 3 and 6 , the crank assembly 22 is rotatably supported and journaled to one of the side wall members 24 at a position above the axis of rotation A to elevate the point of operation for the device. In an alternative embodiment, the crank assembly 22 is rotatably supported and journaled to one of the side wall members 24 at the axis of rotation A. In this manner, the crank could be directly connected to the reel as is well known in the art.
The crank assembly preferably includes a foldable handle 68 for a compact storage and shipping configuration. The foldable handle may include a sleeve 70 that is constructed and arranged to rotate about the handle during operation of the crank. In the preferred embodiment the crank 22 is indirectly connected to the spool assembly via a first gear train 18 to provide rotation thereto. A level-wind assembly 16 is optionally located between the side wall members 24 at a position below the axis of rotation A. The level-wind assembly is operably connected to said spool assembly via a second gear train 20 so that rotation of the spool assembly provides reciprocating movement to a hose guide 28 to uniformly and smoothly wrap a hose onto the spool assembly 14 to provide a compact storage configuration. It should also be noted that the device may be utilized without the level-wind or with a manually operated level-wind (not shown) without departing from the scope of the invention. In a preferred embodiment, the level-wind assembly 16 is automatically reciprocated with the reel. The automatic level-wind assembly 16 includes a double-helix lead screw 72 suitably supported and journaled in the side panels 24 for rotational movement and a single guide element 74 extends between the side panels. It should be noted that while a rod is illustrated as the guide element, other structures such as rails, cables, grooves and the like may be utilized without departing from the scope of the invention. When the spool 14 is rotated the second gear train 20 illustrated in FIG. 6 , transfers rotary motion from the spool 14 to the double-helix lead screw 72 . A guide 28 cooperates with the double-helix lead screw 72 and slides along the guide element 74 to cause the guide 28 to reciprocate back and forth across the spool 14 facilitating even distribution of the flexible elongate member onto the spool.
Still referring to FIG. 6 , in order to provide manual rotation of the hose reel 14 and reciprocation of the automatic level-wind assembly 16 , a first gear train 18 is positioned within one of the side panels 24 . The crank assembly 22 ( FIG. 3 ) includes an input shaft (not shown) extending inwardly through an opening 76 in an upper portion of the side panel 24 and rotatable with respect thereto. The input shaft is secured to the input gear 78 of the first gear train 18 at a position at or above the axis of rotation A. The spool gear 80 is suitably secured to the spool 14 so as to be rotatable therewith. Idler gears 82 A and 82 B are positioned within the side panel 24 to be freely rotating with respect to the side panel and directly meshed with the input gear 78 , one another, and the spool gear 80 to provide gear powering therebetween. Thus, rotational movement of the input gear 78 with handle assembly 22 will cause similar rotational movement of the spool gear 80 and spool 14 . Preferably the spool gear 80 will be larger in pitch diameter than the pitch diameter of the input gear 78 thereby achieving a torque increasing gear reduction desired by the present invention. It should be noted that while the crank is illustrated herein as connecting to the reel at a position above the axis of rotation, the crank may be directly coupled to the reel or any number of idler gears may be utilized for spacing to place the crank above the axis of rotation without departing from the scope of the invention.
Still referring to FIG. 6 , the second gear-train 20 utilizes rotation of the spool 14 to cause rotation of the double-helix lead screw 72 . The lead screw gear 84 is suitably secured to the lead screw 72 to be rotatable therewith. Idler gears 86 A and 86 B are positioned within the side panel 24 to be freely rotating with respect to the side panel 24 and directly meshed with the spool gear 80 , one another, and the lead screw gear 84 to provide direct gear powering therebetween. Thus, rotational movement of the spool gear 80 will cause similar rotational movement of the lead screw gear 84 and reciprocation of the hose guide 28 . Preferably the spool gear 80 will be larger than the lead screw gear 84 thereby achieving the desired amount of hose guide 28 travel per spool 14 revolution for a compact hose storage configuration. It should be noted that while the level-wind assembly is illustrated herein as positioned at a lowermost position within the enclosure, the level wind assembly may utilize more or less idler gears for spacing to position the level-wind at any position at or below the axis of rotation without departing from the scope of the invention.
Referring now to FIG. 3 , the enclosure includes a pair of spaced apart side members 24 and may include a storage bin 88 that extends between the side panels. The storage bin is preferably formed as a single piece having multiple living hinges 90 which facilitate assembly. A pair of tabs 92 extend outwardly from the sides of the storage bin to facilitate connection to storage bin receivers 94 which are preferably integrally formed to the inner surface of the side members 24 . Alternatively, the storage bin may be formed of multiple components that are glued or suitably fastened together and attached to the inner surface of the enclosure panels as is known in the art. The storage bin 88 can be used to store various hose attachments, such as, spray heads, nozzles and the like. Consumers will recognize the advantage to having the handy storage bin 88 mounted within the enclosure assembly, so that hose attachments can be readily stored with the hose and easily accessed, rather than stored in another location and possibly misplaced or lost.
All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings/figures included herein.
One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned, as well as those inherent therein. The embodiments, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims. | 4y
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BACKGROUND
1. Field
This device relates to a conductive sheath for electromagnetically shielding electric cable.
2. Prior art
Japan Published Unexamined Utility Model Application No. S61-120118 discloses a tube-shaped cable sheath made of a knitted wire mesh. Unfortunately, it comes in a fixed sizes, so different sizes must be used with cable bundles of different diameters. Also, because it is a tube, it cannot be installed after the cable bundle has been installed.
A prior-art cable sheath addressing these problems has been proposed. As shown in FIG. 14, a shielding strip 8 is spirally wound around a bundle of cables 4 and is held in place by cable ties 9. However, if the cable is bent, the closed surface of the sheath is likely to break between the cable ties 9. To prevent this, more cable ties 9 must be used at closer intervals. This makes installation more expensive and more tedious.
SUMMARY
The present invention includes a shield and a fastener. The fastener holds the shield in place, forming a closed conductive surface. As shown in FIG. 13, the fastener has hooks for catching and holding the mesh fibers of the shield. In one variation, the shield winds around the cable bundle and the fastener holds the overlapping portions of the shield together. Many winding methods may be used, varying, for instance, with the diameter of the cable bundle. Moreover, this cable sheath is easy to install even after the cables have been laid.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a first embodiment.
FIG. 2A shows one variation of the first embodiment with a fastener inserted inside the shield.
FIG. 2B is a sectional view of the first variation on the first embodiment taken along line IIB-IIB in FIG. 2A.
FIGS. 3A through 3E are sectional views of several more variations on the first embodiment.
FIG. 4 is a perspective view of another variation on the first embodiment.
FIGS. 5A and 5B are sectional views of two more variations on the first embodiment.
FIGS. 6A and 6B are perspective views of two more variations on the first embodiment.
FIGS. 7A through 7C are sectional views of a second embodiment during installation.
FIG. 8A is a sectional view of a third embodiment.
FIG. 8B is a sectional view of a fourth embodiment.
FIG. 9 is a perspective view of a guard used in a fifth embodiment.
FIG. 10 is a sectional view of the fifth embodiment.
FIG. 11 is a perspective view of a sixth embodiment.
FIG. 12 is a sectional view of the first embodiment using a conductive fastener.
FIG. 13 shows some hook designs.
FIG. 14 is a perspective view of a prior-art cable sheath.
DESCRIPTION
A first embodiment is shown in FIG. 1. A tubular shield 2 made of conductive-wire mesh is wrapped around a cable 4 bundle, and is secured by fastener 3 with hooks 6a. FIG. 2A shows an unrolled segment of the cable sheath 1. The fastener 3 is inserted into the sleeve-like shield 2 and is pressed against one side so the hooks 6a protrude, as indicated in FIG. 2B. Thus prepared, the sheath 1 may be wrapped around a cable 4 bundle, as shown in FIG. 1. The hooks 6a of the fastener 3 hold the ends of the shield 2 together forming a closed conductive surface.
The cable sheath 1 can be used many ways, some of which are shown in FIGS. 3A through 4. In FIG. 4, the cable sheath 1 is spirally wound around a cable 4 bundle where the circumference of the bundle exceeds the width of the cable sheath 1. FIGS. 5A through 6B show some variations on the basic cable sheath 1. A fastener 3 is used at each end of the shield 2 in FIGS. 5A and 5B. An additional piece 5 of shield 2 is used, in FIG. 5B, to bridge the gap because the cable 4 bundle circumference exceeds the cable sheath 1 width. The variations in FIGS. 6A and 6B are similar to the one in FIG. 4 except that the fastener 3 is not inserted into the shield 2, but is wound separately. In FIG. 6A the fastener 3 is under the shield 2; in FIG. 6B the shield 2 is under the fastener 3.
A second embodiment of the cable sheath 1a, shown in FIGS. 7A and 7B uses a flat, single-sided fastener 3a. In a third embodiment of the cable sheath 1b, shown in FIG. 8A, the fastener 3b spreads throughout the shield 2. A fourth embodiment cable sheath 1c, shown in FIG. 8B, is like the third embodiment cable sheath 1b except the hooks 6a protrude from both sides of the fastener 3c.
A fifth embodiment of the cable sheath 1d, shown in FIG. 10, uses the flexible guard 7 shown separately in FIG. 9. A cable sheath 1, for instance the first embodiment cable sheath 1, is attached inside the guard 7 at a connection site 7a. The connection site 7a is located close to the opening of the guard 7 so the cable sheath 1 wraps around the cable 4 bundle when the guard 7 is installed.
The shield 2 need not be entirely mesh. A sixth embodiment of the cable sheath 1e, shown in FIG. 11, has conductive mesh tubes 2a at both sides of a conductive sheet 2b. The fastener 3 may be inserted into either tube 2a. The resulting cable sheath 1e may be used as the other embodiments are used.
If the fastener 3 and its hooks 6a are conductive, they form part of the closed conductive surface, thus improving the overall conductivity of the closed surface. FIG. 12 shows the first embodiment cable sheath 1 taking advantage of a conductive fastener 3d.
Although this description has focused on a simple hook 6a, many different hook designs may be used for the fastener 3. Four designs are shown in FIG. 13: a simple hook 6a, a double hook 6b, a T-hook 6c, and a knob hook 6d. Other designs could be used as well. The preceding description also focuses on the use of conductive mesh; however, other conductive materials, e.g., steel wool or expanded metal, could be used for the shield 2 as long as they can be securely retained by the hooks 6a of the fastener 3.
This description merely describes some embodiments of the claims without exhausting all of the possible variations; the scope of this invention is limited only by the following claims. | 4y
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FIELD OF THE INVENTION
The present invention relates to an integrated controller for the detecting and operating one or more expansion cards. More specifically, the present invention relates to an integrated controller for detecting and controlling PC Cards (16-bit PCMCIA cards and 32 bit-CardBus cards), and smart cards. Particular utility of the present invention is to provide an integrated controller for mobile computing devices, e.g., laptop computers, etc, although other utilities are contemplated herein.
DESCRIPTION OF RELATED ART
The need for security and enhanced privacy is increasing as electronic forms of identification replace face-to-face and paper-based ones. The emergence of the global Internet, and the expansion of the corporate network to include access by customers and suppliers from outside the firewall, have accelerated the demand for solutions based on public-key technology. A few examples of the kinds of services that public key technologies enable are secure channel communications over a public network, digital signatures to ensure image integrity and confidentiality, and authentication of a client to a server (and visa-versa).
Smart cards are a key component of the public-key infrastructure that Microsoft is integrating into the Windows platform because smart cards enhance software-only solutions such as client authentication, logon, and secure e-mail. Smart cards are essentially a convergence point for public key certificates and associated keys because they provide tamper-resistant storage for protecting private keys and other forms of personal information; isolate security-critical computations involving authentication, digital signatures, and key exchange from other parts of the system that do not have a “need to know”; and enable portability of credentials and other private information between computers at work, home, or on the road.
It is estimated that the smart card will become an integral part of the Windows platform because smart cards will enable new breeds of applications in the same manner that the mouse and CD-ROM did when they were first integrated with the Personal Computer (PC). Incompatibility among applications, cards, and readers has been a major reason for the slow adoption of smart cards outside of Europe. Interoperability among different vendors' products is a necessary requirement to enable broad consumer acceptance of smart cards, and for corporations to deploy smart cards for use within the enterprise.
ISO 7816, EMV, and GSM
In order to promote interoperability among smart cards and readers, the International Standards Organization (ISO) developed the ISO 7816 standards for integrated circuit cards with contacts. These specifications focused on interoperability at the physical, electrical, and data-link protocol levels. In 1996, Europay, MasterCard, and VISA (EMV) defined an industry-specific smart card specification that adopted the ISO 7816 standards and defined some additional data types and encoding rules for use by the financial services industry. The European telecommunications industry also embraced the ISO 7816 standards for their Global System for Mobile communications (GSM) smart card specification to enable identification and authentication of mobile phone users.
While all of these specifications (ISO 7816, EMV, and GSM) were a step in the right direction, each was either too low-level or application-specific to gain broad industry support. Application interoperability issues such as device-independent APIs, developer tools, and resource sharing were not addressed by any of these specifications.
PC/SC Workgroup
The PC/SC (Personal Computer/Smart Card) Workgroup was formed in May 1996 in partnership with major PC and smart card companies: Groupe Bull, Hewlett-Packard, Microsoft, Schlumberger, and Siemens Nixdorf. The main focus of the workgroup has been to develop specifications that solve the previously mentioned interoperability problems. The PC/SC specifications are based on the ISO 7816 standards and are compatible with both the EMV and GSM industry-specific specifications. By virtue of the companies involved in the PC/SC Workgroup, there is broad industry support for the specifications and a strong desire to move them onto an independent-standards tract in the future.
Since its founding and initial publication of the specifications, additional members have joined the PC/SC Workgroup. New members include Gemplus, IBM, Sun Microsystems, Toshiba, and Verifone.
Microsoft's Approach
Microsoft's approach consists of the following:
A standard model for interfacing smart card readers and cards with PCs
Device-independent APIs for enabling smart card-aware applications
Familiar tools for software development
Integration with Windows and Windows NT platforms
Having a standard model for how readers and cards interface with the PC enforces interoperability among cards and readers from different manufacturers. Device-independent APIs serves to insulate application developers from differences between current and future implementations. Device-independence also preserves software development costs by avoiding application obsolescence due to underlying hardware changes.
The most popular method currently being used to interface a smart card with a notebook computer is to use a PCMCIA Type II smart card reader/writer (FIG. 1 ). PCMCIA smart card readers are currently available from companies such as Gemplus, SCM Microsystems and Tritheim Technologies, to name a few. The end user cost for these smart card readers is typically around $150. The cost of the reader is a major portion to the cost of the overall security solution. The adapter card 104 in FIG. 1 depicts the major functional blocks of a conventional smart card reader. The PCIC Host Interface block of the smart card reader provides the electrical interface to the PC Card connector ( 106 , which in turn connects to the PC Card controller 102 . Additional logic is provided to control the interaction between the smart card and the software application. However, as noted above, this solution carries a significant per unit cost, and thus, is an unattractive alternative to large-scale migration to smart card compatibility.
Thus, there exists a need to provide an integrated host controller that provides PC Card, smart card, and Passive smart card adapter operability. Moreover, there exists a need to provide an integrated controller that can replace existing motherboard-mounted PC Card host controllers, without having to retool or redesign the motherboard.
SUMMARY OF THE INVENTION
Accordingly, one object of the present invention is to provide an integrated PC Card and Smart card controller suitable to replace conventional PC Card controllers for integration into current PC motherboard technology.
It is another object to provide a controller as above that is simultaneously fully compatible with PC Card specifications.
It is still another object to provide a Smart card controller, as above, that has an identical pinout arrangement as existing PC Card controllers, thereby permitting the controller to be directly integrated onto a PC motherboard without redesigning and/or retooling costs.
It is another object of the present invention to provide logic and methodology to detect the presence of a smart card or a Passive smart card adapter utilizing existing PC Card specified signals.
In one aspect, the present invention provides a method of detecting the presence of an expansion card using conventional PC Card specification signal lines, during the initial card detection sequence. The method comprising the steps of determining the signal state of a first and second card detection signal lines; determining the signal state of a first and second voltage select signal lines; determining if said first and/or second card detection signal lines, or said first and/or second voltage select signal lines, comprise a signal state that is reserved by a PC Card signal specification; and determining the signal state of a predetermined unused PC Card signal line, relative to said reserved signal state. During the card detection sequence the status change signal (STSCHG) is used to detect a smart card or a smart card adapter. After the detection sequence is completed the STSCHG signal has the original uses based on the PC Card specification for signal definition. Also, in the preferred embodiment, this process determines the presence of a smart card or a Passive smart card adapter by determining whether said first card detection signal and said second voltage select signals are tied together.
In logic form, the present invention provides a device to detect the presence of an expansion card using conventional PC Card specification signal lines, comprising a state machine including a lookup table and a plurality of logic sets, each said logic sets operable to interface with a certain predefined expansion card type, said state machine accepting as input signals a plurality of predetermined card detection and voltage selection signals, and an additional signal, and coupling an appropriate one of said logic sets to an appropriate one of said expansion cards based on a match between said input signals and said lookup table.
In another aspect, the present invention provides an integrated circuit for the detection and operation of a plurality of expansion cards, comprising, a first logic set for detecting and operating a plurality of expansion card types, said first logic set having predetermined signal lines and a pinout arrangement defined by PC Card specifications, and a second logic set for detecting and operating a smart card, wherein said first and second logic being incorporated into a single controller without requiring additional pinouts. In the preferred embodiment, the second logic set is adapted to reassign certain ones of said predetermined signal lines to detect and operate said smart card, so that additional pins are not required.
It will be appreciated by those skilled in the art that although the following Detailed Description will proceed with reference being made to preferred embodiments and methods of use, the present invention is not intended to be limited to these preferred embodiments and methods of use. Rather, the present invention is of broad scope and is intended to be limited as only set forth in the accompanying claims.
Other features and advantages of the present invention will become apparent as the following Detailed Description proceeds, and upon reference to the Drawings, wherein like numerals depict like parts, and wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 depicts a block diagram of a conventional solution to incorporate smart card operability for PC applications;
FIG. 2 is a system-level block diagram of the integrated smart card reader of the present invention;
FIG. 3 is a detailed block diagram of the integrated Smart card reader of the present invention;
FIG. 4 is a state machine block diagram of the integrated Smart card reader of the present invention;
FIG. 5 is a table of conventional PC Card detection and voltage sensing pin arrangements, and an example of the use of a pin arrangement for smart card detection employed by the controller of the present invention;
FIG. 6 is a flowchart of an exemplary smart card and passive smart card adapter detection scheme of the present invention; and
FIGS. 7A and 7B depict tables showing conventional PCMCIA assigned functional pins and their use for Smart Card interface and detection, respectively.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
FIG. 2 depicts a system-level block diagram of how the passive smart card adapter and a smart card interface with a host controller. The controller 10 is integrated into a PC platform, for example, laptop PC. As an example, the PC may be configured as shown, with the controller 10 operating to detect and control one or more expansion device cards that are inserted into Socket A 12 and/or Socket B 14 . It will be understood that the controller 10 of present invention is adapted with the appropriate logic to drive PC Cards as well as smart cards. The PC system typically includes a processor 26 and a data bus 20 . “North Bridge” logic 24 provides communication between the processor 26 and the bus 20 . The controller 10 , of the present invention is likewise adapted to communicate with the bus 20 . In this example, the bus 20 is a PCI bus, however, any bus technology can be incorporated into the controller's logic. To complete the picture, “South Bridge” logic is provided for external bus communications, for example, legacy devices (ISA bus architecture), etc. South Bridge and North Bridge logic are well known in the art. Power IC chip 28 supplies the correct voltages (as determined by the card type inserted into Socket A or B) to the pins of the PC Card connector. Once the type of card is detected (based on the PC Card definitional table of FIG. 5, discussed below), chip 28 supplies the appropriate voltage for that card type.
In one embodiment, the present invention provides a passive smartcard adapter 18 which is configured to be inserted into either Socket A 12 or Socket B 14 , which are in turn configured as either PC Card type I/II/III—type socket interface. The passive adapter 18 of this embodiment includes appropriate connector 84 and passive circuit 86 . The smart card 16 inserted into the passive smart card adapter 18 also includes physical contacts 88 to interface with the physical connector 84 of the adapter. Pinout arrangements 84 and 88 of the adapter and smart card are dictated by the smart card specification, for example PC/SC compliant Smart card specification that meets ISO 7816 electrical specifications and T=0, T=1 protocols. In this embodiment the use of an adapter 18 permits smart card readability and operability without retooling the PC case to include a specific smart card socket. Alternatively, the PC can include a smart card slot 14 ′ as shown in FIG. 2 . In this alternative embodiment, the logic 86 and connector 84 are, of course, provided internally within socket 14 .
Referring now to FIG. 3, a more detailed block diagram of the integrated controller 10 is depicted, showing those logic portions directed to smart card detection and operability. In this example, the controller 10 includes smart card sensing logic 30 A and 30 B, Smart card multiplexer (MUX) logic 32 A and 32 B, Smart card reader logic 34 A and 34 B and interface logic 36 A and 36 B.
It should be noted at the outset that FIG. 3 depicts only the logic associated with smart card and Passive smart card adapter detection and operability, and it should be understood that controller 10 includes additional logic (not shown) to permit detection and operation of conventional PC Card's. Conventional PC Card controllers detect the type of card inserted into a slot using a set of card detection pins, CD 1 and CD 2 , and a set of voltage sense pins VS 1 and VS 2 . The coupling combinations between these pins (with reference to ground) indicate to the appropriate logic which type of card has been inserted into the socket. For example, as shown in the table of FIG. 5, the coupling combination of CD 1 , CD 2 , VS 1 and VS 2 determine whether the PC Card inserted is a 16-bit PCMCIA card or a 32-bit CardBus card. Moreover, as is shown in the table, this combination also determines the driving voltage for the particular type of card. For example, 3.3 V, 5 V, X.X V and Y.Y V. In the last two rows of the table of FIG. 5, it is to be noted that the listed combinations of CD 1 , CD 2 , VS 1 and VS 2 are reserved in the PC Card specification. The present invention utilizes one of these reserved combinations of CD 1 , CD 2 , VS 1 and VS 2 , and additionally uses a status change signal, STSCHG, to indicate whether a smart card has been inserted into the slot (either directly, or via an adapter). The status change signal is preferably used in the present invention since this signal is not utilized during the detection process for conventional PC Card cards, and is only used once the card type is known.
Thus, in one sense, the smart card sensing logic 30 A shown in FIG. 3 can be viewed as a state machine that determines the type of card inserted into a socket. To that end, and referring to FIG. 4, a state machine representation of the card sensing logic 30 A of FIG. 3 is depicted. As is shown, the card sensing logic 30 A accepts as inputs CD 1 , CD 2 , VS 1 , VS 2 and status change (labeled 40 , 42 , 44 , 46 and 48 , respectively). In accordance with the reserved arrangement of CD 1 , CD 2 , VS 1 , VS 2 as shown in FIG. 5, and the addition of the status change signal, the state machine 30 A determines the appropriate logic 32 A for communicating with the given type of card. For example, certain combinations of CD 1 , CD 2 , VS 1 , VS 2 (as indicated in FIG. 5) will dictate that the card inserted into the socket is either a 16-bit PC card or a 32-bit CardBus PC card. Accordingly, the state machine 30 A will activate the appropriate logic 50 or 52 for the given card type. It should also be noted that the particular voltage of the inserted card is also determined using the combination of these four pins. Extending the capabilities of conventional PC Card controllers, the present invention also monitors the STSCHG pin to determine if a smart card or a passive smart card adapter has been inserted into the socket, and likewise activates the appropriate logic 54 to communicate with the smart card, for example, logic 32 A as shown in FIG. 3 . To determine the states of CD 1 , CD 2 , VS 1 , VS 2 and STSCHG, the card sensing logic 30 A can produce, for example, a pulse train signal on selected ones of these pinouts, and by monitoring the signal on one or more of the other pins (with respect to ground), it can then be determined the card type inserted into the socket.
The smart card sensing logic 30 A and 30 B operate to detect both a smart card or a passive smart card adapter and PC Cards, based on the Table in FIG. 5 . The pin assignments shown in FIG. 5 are designated by the PC Card specification, and are conventional pin assignments for these signal lines. The identity of the card is determined by the values of the voltages of columns 1-4, i.e., CD 2 , CD 1 , VS 2 and VS 1 . Both smart card and passive smart card adapter detection operates by utilizing the reserved combinations of these pins, plus the use of an additional pin, for example, STSCHG signal line. The concept is summarized in the Table of FIG. 7 B. This table shows the pins used to detect PC Cards, smart cards and Passive smart card adapter cards. The signal column for a smart card or passive smart card adapter detection includes one of the reserved areas for CD 1 , CD 2 , VS 1 and VS 2 , as shown in the last two rows of Table of FIG. 5 . It should be noted that although the figures depict the use of signal line STSCHG (which is provided by the conventional PC Card specification), the present invention, generally, could use any pin in the PC Card specification that is unused during the card detection sequence. In other words, from a timing perspective, certain signal lines in the PC Card specification remain unused during the card detection process. The present invention utilizes one (or more) of these signal lines, in conjunction with the reserved combination of CD 1 , CD 2 , VS 1 , and VS 2 , to effectuate smart card or passive smart card adapter detection. Thus, the FIGS. represent only one of many examples for the use of an additional signal pin that could be used for smart card detection.
A flow chart 60 of the card-type detection process is depicted in FIG. 6 . For clarity, the corresponding reference numerals of the logic to detect and operate PC Card, smart card and passive smart card adapter cards (as shown in FIGS. 2 and 3) are omitted. Initially, the detection logic seeks the presence of CD 1 , CD 2 , VS 1 , VS 2 , and STSCHG 62 . If not present, or otherwise unavailable, it is assumed the no card has been inserted into a socket, and thus the card detection signals (CD 1 and CD 2 ) are blocked 64 . Once a card is inserted, the detection logic monitors the falling edge of CD 1 or CD 2 66 . This is dictated by the PC Card specification for determining the presence of a card. Once a card is detected, the detection logic of the present invention toggles CD 1 , CD 2 , VS 1 , VS 2 , and STSCHG to determine the type of card inserted 68 . Toggling, as cited above, can be in the form of a pulse train signal, or other toggling signal. The detection logic proceeds by polling CD 1 , CD 2 , VS 1 , VS 2 , and STSCHG in the following manner. First, the logic determines if VS 1 and CD 2 are tied to ground 70 . If not, it is known that a 16-Bit PCMCIA Card or 32-bit CardBus card is inserted 72 , as indicated by the table of FIG. 5 . If yes, the logic determines if VS 2 and CD 1 are tied together 74 . If this is not the case, again it is known that a 16-Bit Card or 32-bit CardBus card is inserted 76 , as indicated by the table of FIG. 5 . If it is determined that CD 1 and STSCHG are tied together 78 , then it is determined that a smart card or a passive smart card adapter is present. Either the passive smart card adapter is inserted into the socket, or a smart card is inserted directly into a smart card socket 82 .
Another feature of the present invention is to provide an integrated controller circuit 10 , which can be directly integrated with current PC Card controller logic. Conventional PC Card controller logic is an IC package that is mounted directly on the motherboard, which has 208 pins, and each of these pins is assigned by the PC Card specification. Another feature is to provide a controller 10 that can directly replace conventional controllers, without having to reconfigure pin assignments, add additional pin configurations, alter the motherboard, or change the tooling required. To that end, and referring to the table of FIG. 7A, the controller 10 of present invention includes both conventional, legacy interface card signals and smart card signals. As is shown in this table, the same pins (leftmost column) used to interface with conventional 16 and 32 cards are likewise used to interface with the smart card. Thus, no additional pins are required. Referring again to FIG. 3, if a smart card is detected into a socket, logic 30 A or 30 B communicates with and enables logic 34 A or 34 B, to enable smart card readability. Logic 34 A and 34 B enable the socket MUX logic 32 A or 32 B, so that the socket (A or B) can communicate with the cardbus/PCI controller logic 36 A or 36 B, which communicate with the PCI bus 20 (via PCI interface 38 ). As should be understood, the smart card logic 30 A, 30 B, 34 A and 34 B of the present invention directly interfaces with the MUX logic 32 A and 32 B and communicates with bus interface controllers 36 A and 36 B using conventional PC Card communication protocols. If a conventional card is inserted into a socket (socket A or B), then conventional logic (not shown) incorporated into the controller 10 activates MUX 32 A and 32 B and communicates with bus interface controllers 36 A and 36 B using conventional PC Card communication protocols.
To facilitate direct integration with conventional PC Card logic sets, the present invention controls a predetermined number of pre-assigned pins to effectuate smart card communication. For example, as shown in FIG. 7A, pins 17 , 51 , 58 , 47 , 32 , GND, 18 , 16 and 40 , as specified by the PC Card standard, are utilized by the present invention to operate both smart cards and PC cards. Therefore, no extra pins are required by the controller 10 to effectuate Smart card operability. In operation, once the smart card has been detected (as described above with reference to FIGS. 3 - 6 ), logic 34 A or 34 B reassigns the operability of the PC Card pins noted in FIG. 7A to effectuate Smart card readability. The signal assignments, set forth under the smart card Signal column of FIG. 7A, are the required signals to read smart Cards.
The table and FIG. 7A is included as a lookup table in the controller 10 of the present invention to operate PC Cards. Likewise, the tables of FIG. 5 and FIG. 7B are included as lookup tables in the controller 10 for the detection of PC Cards and smart Cards. To this end, and view the logic sets 30 A and 30 B as a state machine (shown in FIG. 4 ), the state machine compares the input signals to the lookup tables of FIGS. 5 and 7B to couple the appropriate logic to the card.
Those skilled in the art will recognize that CD 1 , CD 2 , VS 1 and VS 2 comprise card detect and voltage select signals, respectively, as specified by the conventional PC Card signal specification. In the tables of FIGS. 5, 7 A and 7 B, and the flowchart of FIG. 6, the nomenclature used for these signal lines includes, for example, CD 1 #, CD 2 #, VS 1 #, VS 2 #, etc., which are the formal names for these conventional signal lines. However, it should be apparent that the use of CD 1 , CD 2 , VS 1 and VS 2 are shorthand versions of these formal names, and may be used interchangeably.
Thus, it is evident that there has been provided an integrated Smart card controller and Smart card detection process that satisfies the aims and objectives stated herein. It will be apparent to those skilled in the art that modifications are possible. For example, although the present invention has been described with reference to detection and operation of smart Cards, the present invention is equally adapted for the detection and operation of any type of expansion cards, in addition to conventional PC Cards. Other modifications are possible. For example, it may be desirable to include a software lock on the operability of the smart card logic shown herein. Accordingly, the logic depicted in FIG. 3 can include an enable bit, which selectively turns on and off smart card detectability and operability. To that end, and referring to FIG. 6, the smart card detection process may alternatively include the step of determining if an enable bit is enabled, and if CD 1 and STSCHG are tied together 84 . If this is not the case, the smart card the logic will not detect the presence of a smart card. This feature of the present invention permits, for example, manufacturers to offer smart card compatibility as an upgrade option, while still integrating the core logic of the controller 10 . Those skilled in the art will recognize additional modifications, and all such modifications are deemed within the scope of the present invention, only as limited by the appended claims. | 4y
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a device for treating gases by means of a surface plasma, in the presence of a catalyst.
The fields of use of the present invention comprise, in particular, the degradation of pollutants likely to be contained in gases, the reforming, and the upgrading of gases.
2. Description of Related Art
In the field of gas treatment, methods using a plasma may result in being particularly advantageous since they enable elimination of pollutants at ambient temperature for a low energy cost when the elements are present in the gases in minute quantities. They may also lower the temperature of reaction between two gaseous compounds and/or lower the power necessary to carry out a reaction between two compounds. The plasmas may be volume or surface plasmas at atmospheric pressure.
In the case of atmospheric plasmas, the dielectric barrier discharge or DBD technology is generally implemented. This technology comprises applying an A.C. signal between two electrodes, a dielectric substrate being interposed between the two electrodes to avoid the forming of an electric arc ( FIG. 1 ).
In the case of volume DBD plasmas, the space between electrodes is limited to a few millimeters due to the fact that voltage necessary to generate the plasma increases with the inter-electrode space ( FIG. 1 ) and that the thickness of the dielectric substrate is linked to its dielectric strength. The inter-electrode spacing depends, in particular, on the nature of the dielectric substrate and on the applied voltage. The dielectric thickness conventionally is between 3 and 5 mm and the free space for the flowing of gases is of the same order of magnitude, which generates a significant head loss. In such a configuration, and as described in document US 2002/0070127, a catalyst may be introduced in the plasma area by deposition on the surface opposite to the electrode. The electrode itself may also be used as a catalyst in the case where it is made of an electrically-conductive material.
The DBD technology may also be implemented to generate a surface plasma. The plasma is then created in the vicinity of the surface of a dielectric substrate. The two electrodes are arranged on this dielectric substrate, on either side of the main surfaces of the dielectric substrate ( FIG. 2 ).
The plasma area can thus be adjusted according to the inter-electrode space. In this configuration, the distance between dielectric substrates is independent from the discharge parameters. Such surface plasmas create an acceleration of the gas speed near the electrodes, as described in document U.S. Pat. No. 7,380,756. The multiplication of electrodes on the surface enables the creation of jet effects perpendicularly to the surface, as described by Bénard et al. (“ Thin Solid Films ”, Vol. 516, pp. 6660-6667, 2008).
Document FR 2918293 provides using such surface plasmas for the degradation of pollutants in a gaseous atmosphere. It describes the use of a photocatalyst (TiO 2 ) arranged in the form of a thin layer in contact with the dielectric substrate in the inter-electrode space, such a catalyst being intended to select the decomposition products. In this case, the catalyst thus cannot be an electric conductor such as a metal, to avoid a strong decrease of the plasma area.
The present invention relates, in particular, to a device enabling association of the generation of a surface plasma with a wide range of catalysts, for the treatment of gases, in particular the degradation of pollutants, the reforming, and the upgrading of gases.
The present invention enables improved conversion of gases, but also decreased head losses, while providing the lowest possible power consumption and the lowest possible temperature.
SUMMARY OF THE INVENTION
The Applicant has developed a gas treatment device where a plasma enables to generate, from the gases present, radicals, ions, and active species from the ambient temperature. This device enables to limit head losses and to promote the interaction with species activated by the surface plasma and a catalytic system.
The catalytic system interacts with the species, in particular the pollutants, to increase the plasma efficiency, and also acts on the selectivity of the reactions.
More specifically, the present invention relates to a device for treating gases by means of a surface plasma, comprising:
at least one dielectric substrate having two opposite main surfaces, at least one first electrode and at least one second electrode being respectively deposited on the two opposite main surfaces of the substrate, the first and second electrodes being connected to the two terminals of an electric power supply source; at least one catalytic support independent from the dielectric substrate and from the electrodes, and integrating a catalyst.
Term electrode is used to designate an electrode or a plurality of electrodes connected to the same source and thus having the same potential. The electric power supply source advantageously has an A.C. or pulse signal.
“Plurality of electrodes” is advantageously used to designate electrodes placed parallel to one another.
“Independent” here means a physical independence of the catalytic support from the substrate; in other words, the catalytic support is not in contact with the substrate, and thereby, is not in contact with the electrodes either. More specifically, the formed surface plasma does not come into contact with the catalytic support, and thus, the plasma does not risk deteriorating the catalytic support. The surface plasma enables to promote the accelerated sending back, and this, substantially perpendicularly to the substrate surface, of the species contained in the gas flow to be treated.
Generally, the gases treated by means of the device according to the present invention comprise VOCs (Volatile Organic Compounds), NO x (nitrogen oxides) . . . . The quantities of pollutants may vary from less than 1 ppm to several thousands of ppm according to the application and to the nature of the treated gases.
As already indicated, the configuration of the device according to the present invention enables limiting head losses and reinforcing the contact between the active species created by a surface plasma and the catalytic support or catalyst. Indeed, the presence of a catalyst between two dielectric substrates enables a decrease in the power consumption necessary to treat the gas. The species created by the surface plasma are directed towards the catalytic support, given that these plasmas create an acceleration of the gas speed around the electrodes and jet effects perpendicular to the surface of the dielectric substrate (Cf. Bénard et al.).
It should be noted that the surface plasma is formed around each of the two main surfaces of the dielectric substrate between the first electrode and the second electrode.
Further, the device according to the invention provides a greater versatility than prior art devices, the catalytic support being independent from the dielectric substrate comprising the electrodes. It causes a synergy between the catalyst which is positioned between two dielectric substrates, and generally in porous bodies (foam or honeycomb). The invention thus has the advantage of being able to associate with the plasma a wide range of catalysts (metal, oxide, or mixture) comprised in an electrically-conductive or insulating catalytic support (foam, honeycomb). On the other hand, in this device, the thickness of the catalytic support is not limited, and it should only be lower than the spacing between two dielectric substrates, when present.
Advantageously, the first or second electrodes of the device according to the present invention may have a width advantageously in the range between 1 mm and 10 cm, and more advantageously still between 3 and 5 mm.
In a specific embodiment, each electrode may be formed of a plurality of parallel strips, connected to the same potential, arranged on the dielectric substrate, with the projection of each of the electrodes on a plane parallel to the main plane of the substrate forming an interdigitation. Thus, the surface of the dielectric substrate is advantageously optimized and a plurality of surface plasmas may be generated.
Advantageously, the surface area of the electrodes deposited on the dielectric substrate amounts to between 10 and 90% of the total area of the main surface of the dielectric substrate comprising the electrodes, more advantageously between 30 and 50%.
The electrodes deposited on a main surface of the dielectric substrate may be positioned substantially orthogonally or substantially parallel to the general direction of the flow of the gas to be treated. They are preferably orthogonal.
The inter-electrode spacing, defined by the distance separating the projection of the electrodes on a plane parallel to the main plane of the substrate is in the range between 2 mm and 15 mm, advantageously between 4 and 8 mm.
Further, the ratio between the inter-electrode space such as defined hereabove and the electrode width typically is in the range between zero and 2.
Preferably, the thickness of each of the electrodes is in the range between 1 μm and 2 mm.
Advantageously, the catalytic support may appear in the form of a plate of dense material; of metal or ceramic foam; or of metal or ceramic honeycomb. It is advantageously made of:
ceramic: zirconia, yttria-stabilized zirconia, magnesium oxide, cerium oxide, vanadium oxide, cordierite, WO 3 , TiO 2 , ZnO, and mixtures thereof; or of metal: Al, Cu, Ni, Zn, stainless steel, Ti, FeCrAl, and mixtures thereof.
Further, the catalytic support generally has a thickness advantageously in the range between 1 mm and 10 cm, and more advantageously still between 5 mm and 5 cm.
The catalytic support comprises a catalyst advantageously capable of being selected from the group comprising metal oxides, nitrides, metals, and mixtures thereof, more advantageously still the following metals: Pt, Ag, Ru, Rh, Cu, Fe, Cr, Pd, Zn, Mn, Co, Ni, V, Mo, Au, Ir, Ce.
To limit head losses, the dielectric substrate and the catalytic support are advantageously spaced apart by from 5 mm to 10 cm, and more advantageously by from 5 mm to 5 cm.
The dielectric substrate is advantageously made of a material selected from the group comprising silica, glass, and alumina.
In a preferred embodiment, the device according to the present invention may comprise at least two dielectric substrates spaced apart from each other, their spacing being preferably in the range between 10 mm and 15 cm, and more advantageously between 1 and 5 cm. The device comprises at least one catalytic support advantageously positioned between two main surfaces comprising the first electrodes, or between two main surfaces comprising the second electrodes.
In this configuration, the catalytic supports are arranged between the dielectrics so that they at least partially cover by projection the area of the electrodes and of the plasma.
The catalytic support is arranged in front of the surface of the dielectric support having the plasma generated thereon.
In a specific embodiment, the device for treating gases by means of a surface plasma according to the present invention has a cylindrical shape. The dielectric substrate and the catalytic support thus have cylindrical shapes and are coaxial. The dielectric substrate can thus be arranged inside of a catalytic support of cylindrical shape. The same applies for the catalytic support, which can be arranged inside of a dielectric substrate of cylindrical shape.
Generally, the surface plasma may preferably be generated between 900 mbar and 20 bar, more preferably between 900 mbar and 2 bar, and more preferably still at the atmospheric pressure.
The present invention also relates to the use of the device for treating gases by means of a surface plasma such as described hereabove for the degradation of pollutants (VOC, NO x , . . . ) capable of being contained in gases, but also for the reforming of hydrocarbons, of alcohol, or the upgrading of CO 2 .
In particular, the present invention has the following advantages:
the distance between dielectric substrates can be adjusted according to the envisaged application; the structure of the catalytic support can be modified according to the envisaged application; the nature of the catalyst can be selected according to the envisaged application; the distance between the dielectric substrate and the catalytic support can be adjusted according to the envisaged application to limit head losses.
The invention and the resulting advantages will better appear from the following non-limiting drawings and examples, provided as an illustration of the invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the forming of an atmospheric plasma according to prior art between two electrodes deposited on two distinct dielectric substrates, one of the dielectric substrates being interposed between the two electrodes.
FIG. 2 illustrates the forming of a surface plasma on each surface according to prior art between two electrodes deposited on either side of a same dielectric substrate.
FIG. 3 illustrates a device for treating gases by means of a surface plasma according to the present invention, comprising two catalytic supports and three dielectric substrates partly covered with electrodes.
FIG. 4 illustrates the projection of the electrodes on a same plane parallel to the main plane of the substrate.
FIG. 5 illustrates a device for treating gases by means of a surface plasma according to the present invention of cylindrical geometry, comprising two dielectric substrates and two catalytic supports.
FIG. 6 illustrates the cross-section view of a device for treating gases by means of a surface plasma according to the present invention showing the inter-electrode space between the first and the second electrode deposited on a dielectric substrate.
FIG. 7 shows the toluene conversion rate according to the specific energy applied to a device according to prior art (diamonds) and to a device according to the present invention (squares) in the context of the treatment of gases.
DETAILED DESCRIPTION OF THE INVENTION
As already mentioned, FIG. 1 illustrates the forming of a volume plasma at atmospheric pressure (atmospheric plasma) ( 1 ) between two electrodes ( 5 , 6 ) connected across an electric power supply source ( 4 ) according to prior art. The two electrodes are deposited on two dielectric substrates ( 3 ) spaced apart from each other. The atmospheric plasma ( 1 ) is generated between the two electrodes ( 5 , 6 ), separated from each other, on the one hand, by one of the dielectric substrates, and on the other hand, by the space separating the dielectric substrates.
FIG. 2 illustrates the forming of a surface plasma ( 2 ) on each surface between two electrodes ( 5 , 6 ) connected across an electric power supply source ( 4 ) according to another prior art configuration. The two electrodes are deposited on two opposite surfaces of a same dielectric substrate ( 3 ).
FIG. 3 illustrates the cross-section view of a device for treating gases by means of a surface plasma according to the present invention. This device comprises three dielectric substrates ( 3 ) in the form of wafers, each of the wafers defining two opposite main surfaces.
The two opposite surfaces of each of these substrates each receive a first electrode ( 5 ) and a second electrode ( 6 ), the electrodes being each formed of a series of parallel strips, connected to a potential (electric power source) ( 4 ).
Catalytic supports ( 7 ) also appearing in the form of wafers are interposed between the substrates ( 3 ). The catalytic support ( 7 ) is arranged in front of the surfaces of the dielectric substrates having the surface plasmas generated around them.
FIG. 4 illustrates the projection of the electrodes ( 5 ) and ( 6 ) of the substrate of FIG. 3 on a plane parallel to the substrate. Such a projection shows the interdigitation of the electrodes. The defining of an inter-electrode space ( 8 ) can thus be observed ( FIG. 6 ).
FIG. 5 illustrates a device for treating gases by means of a surface plasma according to the present invention having a cylindrical shape. The use of two coaxial cylindrical dielectric substrates, having a catalytic support interposed therebetween, cylindrical and coaxial with the substrates, can thus be observed. Further, a central catalytic support has been shown.
FIG. 6 shows a longitudinal cross-section view of a dielectric substrate ( 3 ) comprising a first electrode ( 5 ) and a second electrode ( 6 ) interposed to form the inter-electrode space ( 8 ).
EXAMPLES
Examples 1 and 2 relate to the decomposition of toluene in dry air comprising 55 ppm of toluene.
Example 1
Prior Art
The rectangular reactor has a 4-cm height, a 12-cm width, and a 15-cm length. The gas inlet, connected to a gas injection device, in the present case dry air containing 55 ppm of toluene (the pollutant which is desired to be eliminated), is located at one end, and the gas outlet connected to a gas chromatography device to determine the toluene conversion rate, that is, its degradation rate, is located at the other end.
Two dielectric supports having a 12-cm width and a 14-cm length are arranged in the reactor. Shims having a 2-cm width, made of dielectric material (quartz), are arranged on either side along the reactor, to provide a 3-cm spacing between the two dielectric substrates. Electrodes cover the entire width of the dielectric substrate of the reactor (without the shim), that is, 8 cm, their length in the main axis of the reactor being approximately 7.5 cm.
The electrodes are made of copper and have a 3-mm width and a 7.5-cm length.
The inter-electrodes distance ( 8 ) in the configuration of FIG. 6 is 3 mm. Each surface of the dielectric substrates has seven electrodes. To provide the electric continuity, the electrodes are interconnected by a copper electrical circuit, along the width of the dielectric substrate. The first electrodes ( 5 ) are connected to the electric power supply of the generator, while the second electrodes ( 6 ) are grounded.
The device is swept by air containing 55 ppm of toluene until the area of the peak corresponding to toluene and measured by gas chromatography is stabilized to obtain a reference peak.
A sinusoidal voltage of +/−15 kV is then applied to the electrodes connected to the generator for a specific energy consumed by the plasma of 320 J/L.
The toluene conversion rate is determined after 30 minutes by measurement of the area of the corresponding peak by gas chromatography.
Then, the specific energy of the plasma is decreased and after 30 minutes, the new conversion rate is determined. The same procedure is applied for lower specific energies.
The obtained results are disclosed on the graph of FIG. 7 (diamonds), which shows the toluene conversion rates according to the specific energy consumed by the plasma. The “conversion rate” is related to the toluene degradation or decomposition rate. The toluene is converted into CO 2 and H 2 O by a large majority.
Example 2
Invention
The device is identical to that of example 1 but it further comprises a honeycomb catalytic support made of cordierite having a 5-mm thickness.
The catalytic support is arranged between the two dielectric substrates, 12.5 mm away from each of the dielectric substrates. It comprises approximately 500 ppm of platinum and 500 ppm of palladium in channels directed perpendicularly to the dielectric substrate wafers.
The experimental protocol is identical to that of example 1.
The results are also reproduced on the graph of FIG. 7 (squares). For an equivalent specific energy, the device according to the present invention (squares) has a higher conversion rate than that of prior art (diamonds). Accordingly, for an identical toluene conversion rate, the device according to the present invention requires less energy or has a higher conversion rate for an identical specific energy. | 4y
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention is directed to a method of manufacturing a semiconductor structure. More particularly, this invention is directed to a method of manufacturing a semiconductor structure to obtain a structure comprising a Si base, at least one insulating layer residing on the Si base, and a SiC layer residing on the insulating layer, in which the SiC layer is non-indigenous to the Si base. The semiconductor structure may be employed, for example, in the fabrication of high temperature instrumentation such as high temperature electronics and sensors for use in environments such as aircraft engines.
[0003] 2. Background Information
[0004] The use of layers of semiconductor materials in the manufacture of sensing elements such as pressure sensors is well known to those skilled in the art. Such sensing elements are typically fabricated from one or more thin semiconductor layers residing on a thick support structure. The thin semiconductor layer or layers may be obtained by bonding the semiconductor material to a support wafer (e.g. a Si wafer), with an intermediate insulating layer residing therebetween. The semiconductor material is then thinned, typically via etching or grinding, to the desired thickness.
[0005] For high temperature sensor applications semiconductor materials such as silicon carbide (SiC), gallium nitride (GaN) and diamond are of particular interest, due to the wide band gap of such materials. More particularly, as disclosed, for example, in U.S. Pat. No. 5,798,293 (Harris), the cubic form 3C polytype of single crystal SiC (3C-SiC) is an advantageous semiconductor material. However, such materials are typically difficult to process, as they tend to be hard, brittle, fragile and chemically resistant. In particular, although SiC is a preferred material for use in high temperature sensor applications, SiC is very hard and chemically resistant, which makes fabrication of the sensing element difficult. For example, bonding of SiC wafers requires flat and smooth wafer surfaces, yet polishing SiC surfaces to achieve sufficient flatness and surface finish is difficult due to the hardness of SiC. Moreover, even if bonding of the SiC surface is accomplished, thinning of the SiC layer via conventional grinding or a combination of chemical and mechanical etching or polishing remains difficult.
[0006] Various other techniques are known for fabricating desired composite semiconductor material structures. For example, a thin film of active material (e.g. Si or SiC) may be placed on a “handle” wafer. Thereafter, insulating layers may be applied to both the active material thin layer and a separate “base” wafer. The insulating layers are then bonded or annealed to form a single structure, and the “handle” wafer is removed via etching, grinding or polishing or a combination thereof to yield a structure having a base wafer, an active top layer, and an insulating layer therebetween.
[0007] However, because of the disadvantages of etching, grinding and polishing techniques to remove excess Si material (such as the “handle” wafer), other semiconductor material fabrication methods have been developed. For example, in the so-called “SMART-CUT” process, described in U.S. Pat. No. 5,374,564 (Bruel), which is incorporated herein by reference, a thin semiconductor material film is prepared by bombarding a face of a semiconductor wafer material (e.g. a monocrystalline Si wafer) with hydrogen ions to a depth close to the average penetration depth of ions into the wafer, thereby defining an upper wafer portion (i.e. a thin film) and a lower wafer portion (i.e. the substrate). A stiffener constituting at least one rigid material layer is brought into contact with the planar face of the thin film portion of the wafer, and the wafer-stiffener assembly is thereafter thermally treated, thereby causing separation of the thin film from the substrate by the formation and coalescence of hydrogen filled microcracks.
[0008] Similarly, a method of fabricating a 3C-SiC semiconductor layer on a SiO 2 insulating layer is described by K. Vinod et al. in “Fabrication of Low Defect Density 3C-SiC on SiO 2 Structures Using Wafer Bonding Techniques,” J. of Electronic Materials, Vol. 27, pp. L17-20 (1998) (referred to herein as Vinod et al.), which is incorporated herein by reference. The paper describes the fabrication of a 3C-SiC on SiO 2 structure in which etching is employed to expose a SiC surface on an SiO 2 layer.
[0009] In view of the above-described problems associated with the use of grinding, polishing and etching techniques to obtain the desired SiC active layer, it would be desirable to employ a method of manufacturing semiconductor structures having a SiC active layer residing on an insulating layer which avoids the use of such techniques.
[0010] It is one object of this invention to provide a method of preparing a semiconductor structure having a SiC active layer residing on an insulating layer which is prepared by using a handle wafer which is removed without etching, grinding or polishing. It is yet another object of this invention to provide high temperature pressure sensors, high temperature sensors and integrated electronics prepared from the semiconductor structure of this invention, as well as a method of preparing such sensors and integrated electronics.
[0011] It is one feature of this invention that a handle wafer is prepared having a Si substrate, at least one SiC active layer applied to the substrate, and an insulating layer applied to the SiC active layer. The handle wafer is bombarded with ions and the ions are implanted to a desired depth within the SiC active layer. At least one base wafer having an insulating layer is also provided, and the insulating layers of the handle and base wafers are bonded, thereby forming a single structure. Upon thermal treatment of the structure as described in the “SMART-CUT” process as described in U.S. Pat. No. 5,374,564 (Bruel), the Si substrate and a portion of each SiC layer of the handle wafer is removed, yielding at least one semiconductor structure having a base wafer, an oxide insulating layer residing on the base wafer, and a top SiC active layer residing on the insulating layer.
[0012] The method of this invention advantageously may employ thicker wafers which tend to remain flat and facilitate bonding thereto. In addition, the method of this invention advantageously permits the manufacture of large diameter (say 4 inches in diameter) SiC on insulator (SiCOI) having excellent crystal properties which are obtained without using etching. Other objects, features and advantages of this invention will be apparent to those skilled in the art in view of the detailed description of the invention provided below.
SUMMARY OF THE INVENTION
[0013] The method of this invention comprises:
[0014] providing a first material comprising (i) a first (i.e. handle) wafer comprising silicon, (ii) at least one SiC conversion layer obtained by converting a portion of the silicon from the handle wafer to SiC, (iii) at least one layer of non-indigenous SiC applied to the conversion layer, and (iv) at least one oxide layer applied to the non-indigenous SiC layer, wherein a region of the non-indigenous SiC layer has ions implanted therein, thereby establishing an implant region therein which defines a first portion of the non-indigenous SiC layer and a second portion of the non-indigenous SiC layer;
[0015] providing at least one additional material comprising (i) a second (i.e. base wafer) comprising silicon, and (ii) an oxide layer applied to a face of the base wafer;
[0016] bonding the oxide layer of the first material and oxide layer of the additional material to provide an assembly of the first material and additional material; and
[0017] separating at the implant region the second portion of the non-indigenous SiC layer from the first portion of the non-indigenous SiC layer, thereby providing at least one semiconductor structure having a silicon base, at least one oxide insulating layer thereon, and a non-indigenous SiC active top layer residing on the oxide insulating layer. The semiconductor structure obtained from the method of this invention may be used to fabricate integrated electronics, temperature sensors, pressure sensors or other instrumentation which may be used in high temperature environments such as aircraft engines.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIGS. 1 A- 1 G depict cross-sectional views of one embodiment of the method of this invention.
[0019] FIGS. 2 A- 2 G depict cross-sectional views of another specific embodiment of the method of this invention, in which two semiconductor structures of this invention are simultaneously prepared.
[0020] FIGS. 3 A- 3 K depict cross-sectional views of a specific embodiment of this invention, in which a pressure sensor is fabricated.
[0021] FIGS. 4 A- 4 E depict cross-sectional views of another specific embodiment of this invention, in which a pressure sensor is fabricated.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention combines the desirable aspects of the use of a SiC film on a Si “handle” wafer, as described in Vinod et al., and the SMART-CUT process as described in U.S. Pat. No. 5,374,564 (Bruel) to obtain a semiconductor structure having a Si base layer, an oxide insulating layer thereon, and a SiC top layer residing on the oxide insulating layer. This structure is obtained while avoiding the use of etching, grinding or polishing to remove the Si handle wafer from the SiC film by employing the ion implantation technique of the SMART-CUT process to achieve removal of the Si handle wafer. The present invention preserves the cost advantage of the SMART-CUT process and extends it to more easily and reliably obtain an SiC active layer residing on an oxide insulating layer: i.e. a SiCOI substrate in which a monocrystalline SiC film resides on at least one insulating layer which insulates the SiC film from the underlying base layer or substrate.
[0023] The invention is described in greater detail herein relative to non-limiting embodiments of the invention and with reference to the drawings. FIGS. 1 A- 1 G show cross sectional views of the various method steps employed in one embodiment of the invention to prepare the desired semiconductor structure. In FIG. 1A, a first or “handle” wafer 2 which is a Si wafer having a thickness of about 0.3-1.2 mm, say about 1 mm is shown. FIG. 1B depicts the handle wafer 2 having a SiC layer 4 applied to a face of the handle wafer 2 . The SiC layer 4 has a total thickness of about 0.5-1.5 μm, say 1 μm. SiC layer 4 comprises an initial conversion layer 3 and an epitaxial layer 5 residing thereon. The conversion layer 3 is a 3C-SiC layer having a thickness of about 100 Angstroms which is indigenous to the handle wafer 2 and is obtained by converting a portion of Si wafer 2 to 3C-SiC as described, for example, by Wu et al. in “The Microstructure and Surface Morphology of Thin 3C-SiC Films Grown on (100) Si Substrates Using an APCVD-Based Carbonization Process,” Materials Science Forum, Vols. 353-356, pp. 167-70 (2001), which is incorporated herein by reference. This is followed by application of an epitaxial layer 5 of additional SiC (which is not indigenous to the handle wafer) upon the converted SiC layer 3 using a chemical vapor deposition process such as atmospheric pressure chemical vapor deposition (APCVD) as described, for example, by Fleishman et al. in “Epitaxial Growth of 3C-SiC Films on 4-inch Diameter (100) Silicon Wafers by APCVD,” presented at the Silicon Carbide and Related Materials 1995 Conference, Kyoto, Japan, pp. 197-200. Epitaxially grown SiC layer 5 is advantageous in that it provides a virtually defect-free SiC layer for use in the semiconductor structure of this invention, because defects in the SiC crystals remain in the portion of the SiC layer 4 which remains integral to the discarded handle wafer, as further described herein.
[0024] [0024]FIG. 1C depicts an oxide layer 6 applied to SiC layer 4 . The oxide layer 6 is preferably a SiO 2 layer which has been obtained by techniques known to those skilled in the art, including thermal oxidation or chemical vapor deposition (CVD), preferably CVD, as will be well understood by those skilled in the art. Plasma enhanced chemical vapor deposition (PECVD) is particularly preferred to obtain oxide layer 6 . The oxide layer 6 typically has a thickness of about 1000 Angstroms.
[0025] In FIG. 1D, the substrate of FIG. 1C has been subjected to ion bombardment, thereby implanting ions in an implant region 8 (shown in dashed lines) which is located in the epitaxial SiC layer 5 . Implantation must be performed such that above the implant region 8 is at least a portion 10 of the epitaxial SiC layer 5 and the oxide layer 6 adjacent to portion 10 , and below the implant region 8 is the conversion SiC layer 3 , and the handle wafer 2 adjacent thereto. The ions employed may be hydrogen gas ions and possibly other ions alone or in combination such as boron, carbon, phosphorus, nitrogen, arsenic or fluorine ions, most preferably hydrogen gas ions. Ion implantation may be accomplished via techniques and equipment well known to those skilled in the art, such as the method described in U.S. Pat. No. 5,374,564 (Bruel) at col. 5, line 8—col. 6 line 10, which is incorporated herein by reference. The temperature of the substrate of FIG. 1C during implantation is preferably kept below the temperature at which gas (which is produced by the implanted ions) can escape via diffusion from the substrate of FIG. 1C or its component layers. Ion implantation causes a concentrated layer of ions to form and reside in the implant region 8 at a depth close to the average penetration depth of the ions into the SiC layer 4 .
[0026] The oxide layer 6 is typically damaged during the ion implantation process, and accordingly oxide layer 6 is stripped from the epitaxial SiC layer 5 after ion implantation using wet etch in buffered oxide etch (BOE) or dry etch in reactive ion etch (RIE). The epitaxial SiC layer 5 is then cleaned with SO 5 /HF/Chelate, and PECVD is again employed to provide the ion-implanted epitaxial SiC layer 5 with a new oxide layer 9 . The oxide layer 9 balances film stresses and wafer distortion, such that the original wafer flatness is retained. Subsequent polishing and cleaning of the oxide layer 9 may be achieved via the use of chemical-mechanical polishing (CMP), which is a process of using a fine polishing disc with wet chemical enhancement to achieve a fine finish on semiconductor materials (for example, silicon, oxides and nitrides), as will be well understood by those skilled in the art. The desired finish is a flatness of less than 1 micron and a surface of less than 5 Angstroms RMS.
[0027] [0027]FIG. 1E depicts the ion implanted material of FIG. 1D with new oxide layer 9 (labeled I) in proximity to a second material (labeled II) having a base wafer 14 and an oxide layer 16 applied thereto. The base wafer 14 comprises silicon, and in a preferred embodiment is a Si wafer having a thickness of about 100-5000 μm, preferably 300-1000 μm, most preferably about 300-500 μm. The oxide layer 16 is preferably a SiO 2 layer obtained as previously described with respect to oxide layers 6 and 9 . Oxide layer 16 has a thickness of about 1-25 μm say about 10 μm, and may be cleaned and polished using CMP as previously described with respect to oxide layer 9 . Material I is shown inverted as contemplated in the method of this invention for adjoining to material II.
[0028] The oxide layers 9 and 16 of the materials I and II, respectively, are bonded as depicted in FIG. 1F to provide a single assembly. The bonded interface 15 shows the interface between the bonded oxide layers 9 and 16 . The oxide layers are preferably bonded by chemically treating each oxide layer 9 and 16 by chemical activation of these surfaces followed by mechanical adjoining. As will be well understood by these skilled in the art, chemical activation is typically achieved by forming a hydrophilic surface which attaches an OH radical to the SiO 2 molecules residing in the oxide layers. The OH radicals on each oxide surface are attracted to each other, which aids the bonding process. The presence of moisture may also be desirable. The OH radicals are typically provided by cleaning the oxide surfaces with one or more of the following commercially available chemical surface cleaning formulations: SC-1 (hydrogen peroxide, ammonium hydroxide and deionzed water); SC-2 (hydrochloric acid, hydrogen peroxide and deionzed water); “Piranha” (sulfuric acid and hydrogen peroxide); and “Chelate” (a 1:3 blend of hydrogen peroxide and ammonium hydroxide). SC-1, SC-2 and Piranha are described, for example, in S. Wolf and R. Tauber, Silicon Processing For The VLSI Era, Vol. 1 : Process Technology (2d ed. 1986), pp. 128-29.
[0029] After materials I and II have been joined at the interface 15 of oxide layers 9 and 16 to form a single assembly (as depicted in FIG. 1F), the assembly is separated in the vicinity of the ion implant region 8 . This separation is preferably achieved by first heating the assembly to a temperature of about 800-900° C., preferably about 850° C. for up to about one hour, preferably about 0.5 hours. During this first heating step, coalescence of the implanted ion species (e.g. hydrogen) forms microcracks cleaving the assembly in the implant region 8 . The heating of the assembly must be at a temperature above that at which the ion bombardment was carried out. After cleavage or separation as described above, the resulting semiconductor material has the structure depicted in FIG. 1G: i.e. a base Si wafer 14 having thereon at least one oxide insulating layer (oxide layers 16 and 9 in FIG. 1G) and an active non-indigenous epitaxial SiC top layer 10 which is electrically insulated from the base wafer 14 by the at least one oxide insulating layer (shown as the combination of oxide layers 9 and 16 in FIG. 1G). SiC layer 10 is composed only of non-indigenous epitaxially grown SiC obtained as previously described. A subsequent heating of the resulting semiconductor structure depicted in FIG. 1G is then employed in which it is heated to a temperature of 1100-1200° C., preferably about 1150° C. for about 0.5 hours. The SiC layer 10 may then be polished as necessary using techniques well known to those skilled in the art. An additional epitaxial SiC layer (not shown) may also optionally be grown upon SiC layer 10 .
[0030] FIGS. 2 A- 2 G show cross-sectional views of various method steps employed in another embodiment of this invention to prepare two semiconductor structures using a single handle wafer and two base wafers. FIG. 2A depicts a structure having a first or “handle” wafer 202 which is a Si wafer having a thickness of about 0.3-1.2 mm, say about 1 mm. As shown in FIG. 2B, handle wafer 202 has a first SiC layer 104 applied to a face of the handle wafer 202 , and a second SiC layer 204 applied to the opposite face of handle wafer 202 . First SiC layer 104 comprises an initial conversion layer 103 and a non-indigenous epitaxial layer 105 residing thereon. Second SiC layer 204 comprises an initial conversion layer 203 and a non-indigenous epitaxial layer 205 residing thereon. Each SiC layer 104 and 204 is prepared as previously described with respect to FIGS. 1A and 1B.
[0031] [0031]FIG. 2C depicts an oxide layer 106 applied to non-indigenous SiC layer 105 , and an oxide layer 206 applied to non-indigenous SiC layer 205 . The oxide layers 106 and 206 are preferably each a SiO 2 layer which has been obtained as previously described with respect to FIG. 1C.
[0032] In FIG. 2D, the substrate of FIG. 2C has been subjected to ion bombardment, thereby implanting ions in implant region 108 and 208 (shown in dashed lines) which are located in the epitaxial layers 105 and 205 , respectively. Above the implant region 108 is at least a portion 110 of the epitaxial SiC layer 105 , and below the implant region 208 is at least a portion 210 of the epitaxial SiC layer 205 . Ion implantation and subsequent treatment is as described above with respect to FIG. 1D. As previously described, oxide layers 106 and 206 are damaged during ion bombardment, and are replaced by oxide layers 107 and 207 , which are obtained as previously described for oxide layers 106 and 206 .
[0033] [0033]FIG. 2E depicts the ion implanted material of FIG. 2D (labeled VI) in proximity to a second material (labeled III) having a base wafer 115 and an oxide layer 117 applied thereto and a third material (labeled IV) having a base wafer 215 and an oxide layer 217 applied thereto. The base wafers 115 and 215 each comprises silicon, and in a preferred embodiment each is a Si wafer having a thickness of about 100-5000 μm, preferably 300-1000 μm, most preferably about 300-500 μm. The oxide layers 117 and 217 are each preferably a SiO 2 layer obtained as previously described with respect to oxide layers 105 and 205 . Oxide layers 117 and 217 each have a thickness of about 1-25 μm, say about 10 μm. Material III is shown inverted as contemplated in the method of this invention for adjoining to material V, and material IV is also shown in proximate relation to material V prior to adjoining thereto.
[0034] The oxide layers 107 and 117 of the materials V and III, respectively, and the oxide layers 207 and 217 of the materials V and IV, respectively, are bonded as depicted in FIG. 2F to provide a single assembly. Bonding is accomplished as previously described with respect to FIGS. 1E and 1F. Inferface 125 is the bonded interface of oxide layers 107 and 117 , and interface 225 is the bonded interface of oxide layers 207 and 217 , as shown in FIG. 2E.
[0035] After materials III, V and IV have been joined to form a single assembly (as depicted in FIG. 2F), the assembly is separated in the vicinity of the ion implant regions 108 and 208 . This separation is achieved as previously described with respect to FIGS. 1F and 1G. After cleavage or separation as described above, the resulting two semiconductor structures are as depicted in FIG. 2G: i.e. the first semiconductor structure has a base Si wafer 115 having thereon at least one oxide insulating layer (oxide layers 117 and 107 in FIG. 2G) and an active non-indigenous SiC top layer 110 which is electrically insulated from the base wafer 115 by the at least one oxide insulating layer (shown as the combination of oxide layers 117 and 107 in FIG. 2G), and the second semiconductor structure has a base Si wafer 215 having thereon at least one oxide insulating layer (oxide layers 217 and 207 in FIG. 2G) and an active non-indigenous SiC top layer 210 which is electrically insulated from the base wafer 215 by the at least one oxide insulating layer (shown as the combination of oxide layers 207 and 217 in FIG. 2G). A subsequent heating of the resulting semiconductor structures depicted in FIG. 2G is then employed in which the resulting semiconductor structures are heated to a temperature of 1100-1200° C., preferably about 1150° C. for about 0.5 hours. The SiC layers 110 and 210 of each material may then be polished using techniques well known to those skilled in the art. An additional epitaxial layer (not shown) may also optionally be grown upon SiC layers 110 and 210 , respectively.
[0036] The semiconductor structure obtained from the method of this invention is particularly useful in fabricating electronic parts and instrumentation which must be used in hostile environments. In one embodiment, the semiconductor structure may be employed in connection with the fabrication of a pressure sensor useful in high temperature (e.g. 400-600° C.) applications, such as for the measurement of pressure at the exhaust portion of a jet engine. Such an embodiment is described below with reference to FIGS. 3 A- 3 K.
[0037] FIGS. 3 A- 3 K show cross sectional views of the various method steps employed in one embodiment of this invention to prepare a pressure sensor of this invention. In FIG. 3A, a first or “handle” wafer 302 which is preferably a Si wafer having a thickness of about 0.3-1.2 mm, preferably about 1 mm. The handle wafer 302 has a SiC layer 304 applied to a face of the handle wafer 302 . The SiC layer 304 comprises a conversion layer 303 and a non-indigenous SiC layer 305 . Oxide layer 306 (not shown) is initially applied to non-indigenous SiC layer 305 .
[0038] As shown in FIG. 3A, the substrate has been subjected to ion bombardment, thereby implanting ions in an implant region 308 (shown in dashed lines) which is located in the non-indigenous SiC layer 305 . Above the implant region 308 is at least a portion 310 of the non-indigenous SiC layer 305 and the initial oxide layer 306 (not shown) adjacent to the non-indigenous SiC layer 305 . The initial oxide layer 306 is damaged during ion implantation, and has been replaced by oxide layer 309 as shown in FIG. 3A. Preparation of the material depicted in FIG. 3A is accomplished as previously described with respect to FIGS. 1 A- 1 D. The material depicted in FIG. 3A is labeled as material VI.
[0039] [0039]FIG. 3B depicts a Si wafer 314 having a thickness of about up to 500 μm, preferably about 300-325 μm, say about 318 μm. Si wafer 314 has a lower face 321 and an upper face 319 . A pressure sensor diaphragm 322 has been etched, cut or otherwise provided in the Si wafer 314 , using techniques which are well known to those skilled in the art. FIG. 3C depicts the Si wafer 314 having the pressure sensor diaphragm cavity 322 after wafer 314 has been bonded at face 321 to another Si wafer 324 having a thickness of up to about 1000 μm, preferably 300-1000 μm, most preferably about 800 μm. Si wafer 324 has a passageway 325 therethrough which operatively interfaces pressure sensor diaphragm cavity 322 , thereby providing a pathway for a fluid medium (e.g. aircraft engine exhaust gas) to contact pressure sensor diaphragm cavity 322 to enable measurement of the pressure of the gaseous medium. In FIG. 3C, Si wafer 314 also has an oxide layer 316 applied to Si wafer 314 . Oxide layer 316 may be applied by a chemical vapor deposition process such as PECVD as previously described, or may preferably be obtained by fusing wafers 314 and 324 in an oxidizing atmosphere, thereby causing formation of oxide layer 316 which is a thermal oxide layer on the upper face 319 of wafer 314 . The oxide layer 316 has a thickness of about 1-20 μm, say about 1 μm. The assembly of wafer 314 having oxide layer 316 on face 319 thereof and wafer 324 bonded to wafer 314 at face 321 thereof is labeled as material VII in FIG. 3C.
[0040] [0040]FIG. 3D depicts the ion implanted material of FIG. 3A (labeled as material VI) bonded to the second material of FIG. 3C (labeled as material VII). Material VI is shown inverted as contemplated in the method of this invention for adjoining to material VII. The oxide layers 309 and 316 of materials VI and VII, respectively, are bonded as depicted in FIG. 3D to provide a single assembly. The bonded interface 315 shows the interface between the bonded oxide layers 309 and 316 . The oxide layers are bonded using techniques as previously described with respect to bonded materials I and II in FIG. 1F.
[0041] After materials VI and VII have been joined at the interface 315 of oxide layers 309 and 316 to form a single assembly (as depicted in FIG. 3D), separation at the vicinity of the ion implantation region 308 is achieved as previously described with respect to FIGS. 1F and 1G. After cleavage or separation as described above, a pressure sensor precursor is obtained having the structure depicted in FIG. 3E: i.e. a base Si wafer 324 fusion bonded to Si wafer 314 , with Si wafer 314 having thereon at least one oxide insulating layer (shown in FIG. 3E as the single layer 326 which is the combination of oxide layers 316 and 309 in FIG. 3D) and an active non-indigenous SiC top layer 310 which is electrically insulated from the base wafers 314 and 324 by the oxide insulating layer 326 . A subsequent heating of the resulting semiconductor material depicted in FIG. 3E is then employed in which the resulting semiconductor material is heated to a temperature of 1100-1200° C., preferably about 1150° C. for about 0.5 hours. SiC layer 310 may optionally be made thicker using an appropriate chemical vapor deposition technique such as APCVD as previously described, which provides additional SiC (which is not indigenous to the handle wafer). SiC layer 310 may be polished using techniques well known to those skilled in the art.
[0042] An oxide or metal film, photolithographic emulsion, mask and developer are then employed to provide a protective layer or layers (not shown) in a pattern emulating the pattern desired in SiC layer 310 . The photolithographic emulsion is used to pattern the oxide or metal film which in turn is used to protect selected areas of the SiC during etching. The unprotected portion of SiC layer 310 is then selectively removed, as will be well understood by those skilled in the art. As shown in FIG. 3F, after portions of SiC layer 310 have been selectively removed, preferably using RIE, underlying portions of oxide layer 326 are exposed. Upon removal of the remaining protective layer (not shown) a passivation layer 330 , preferably Si-nitride, is then applied over the exposed portions of oxide layer 326 and the remaining portions of SiC layer 310 , as shown in FIG. 3G. As shown in FIG. 3H, opening 332 is provided for access to Si wafer 314 , and opening 334 is provided for access to a remaining portion of SiC layer 310 . Metal contact 336 is provided through opening 332 to contact Si wafer 314 , and metal contact 338 is provided through opening 334 to contact SiC layer 310 , as shown in FIG. 31, thereby providing the necessary electronic connections to the semiconductor material.
[0043] To facilitate its intended use, the pressure sensor as shown in FIG. 31 is preferably adjoined or affixed to a base portion or pedestal 340 shown in FIG. 3J having a conduit 342 therethrough, as described, for example in U.S. Pat. No. 5,515,732, incorporated herein by reference. In a preferred embodiment, base portion 340 is anodically bonded to the lower face 341 of Si wafer 324 as shown. Conduit 342 is operatively associated and aligned with passageway 325 as shown in FIG. 3J to permit passage of the gaseous medium (e.g. aircraft engine exhaust gas) through conduit 342 and passageway 325 to contact pressure sensor diaphragm cavity 322 to enable measurement of the pressure of the gaseous medium. The base portion or pedestal 340 is a fabricated from a material capable of withstanding high temperatures (i.e. 300-1000° C.), such as a ceramic or SiC material. In one preferred embodiment of this invention, the base portion or pedestal is preferably fabricated from PYREX glass. In a particularly preferred embodiment, the exposed or non-bonded end 343 of base portion 340 may be metallized to facilitate further bonding or mounting (not shown). As depicted in FIG. 3K, this may be accomplished by providing one or more metal layers 344 on the exposed or non-bonded end 343 of base portion 340 . This metal layer is preferably a tri-metal layer, as described, for example, in U.S. Pat. No. 5,515,732.
[0044] In another embodiment, as depicted in FIG. 4A, a first material may be prepared as described above with respect to FIG. 3A. FIG. 4A depicts a first or “handle” wafer 402 having a SiC layer 404 applied to a face of the handle wafer 402 . The SiC layer 404 comprises a conversion layer 403 and a non-indigenous SiC layer 405 . Oxide layer 406 (not shown) is initially applied to non-indigenous SiC layer 405 . Implant region 408 located in layer 405 is also shown. Oxide layer 406 is damaged during ion implantation, and has been replaced by oxide layer 409 . FIG. 4B depicts a Si wafer 414 having an upper surface 419 and a pressure sensor diaphragm 422 etched, cut or otherwise provided in Si wafer 414 , as previously described with respect to FIG. 3B. FIG. 4C depicts an oxide layer 416 applied to the upper surface 419 of Si wafer 414 . Oxide layer 416 may be applied as previously described, and has a thickness of about 1-20 μm, say about 1 μm. As shown in FIG. 4D, the ion implanted material of FIG. 4A (labeled as material VIII) is bonded to the second material of FIG. 4C (labeled as material IX) by bonding oxide layers 409 and 416 to provide a single assembly. The oxide layers 409 and 416 are bonded using techniques as previously described. After materials VIII and IX have been joined at the interface of oxide layers 409 and 416 to form a single assembly (as depicted in FIG. 4D), another Si wafer 424 having a thickness of about 100-1000 μm, preferably 300-1000 μm, most preferably about 300-500 μm is fusion bonded to face 421 of joined materials VIII and IX, as depicted in FIG. 4E. As described with respect to FIG. 3C, Si wafer 414 has a passageway 425 therethrough which operatively interfaces pressure sensor diaphragm cavity 422 , thereby providing a pathway for a fluid medium (e.g. aircraft engine exhaust gas) to contact pressure sensor diaphragm cavity 422 to enable measurement of the pressure of the gaseous medium. The assembly as depicted in FIG. 4E may then be separated at the vicinity of the ion implantation region 408 and further processed as described above with respect to FIGS. 3 E- 3 K to obtain the pressure sensor of this invention.
[0045] Although this invention has been illustrated by reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications may be made which clearly fall within the scope of this invention. | 4y
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BACKGROUND OF THE INVENTION
(1) Field of the Invention
The present invention relates to wafer cleaning methods and apparatus for etching, and dissolving and removing metallic impurities from various types of wafers such as semiconductor substrates, glass substrates for photomasks and glass substrates for liquid crystal displays.
(2) Description of the Prior Art
Japanese Patent Publication Laying-Open No. 173720/1987 discloses such a cleaning technique, which comprises the steps of (1) placing a wafer in a treating chamber, (2) supplying vapor of hydrofluoric acid HF/H 2 O into the treating chamber to dissolve and wash oxide films off a wafer surface, (3) stopping the supply of hydrofluoric acid vapor after completion of oxide film removal and supplying high purity water vapor into the treating chamber to wash off hydrofluoric acid adhering to the wafer surface and inside walls of the treating chamber, and (4) stopping the supply of water vapor after hydrofluoric acid is sufficiently replaced by water, and supplying hot nitrogen gas N 2 into the treating chamber to dry the wafer.
As methods of producing vapor of hydrofluoric acid from a tank storing a hydrofluoric acid solution, the above publication discloses (a) heating of the tank, (b) injection of nitrogen gas into the solution to cause its bubbling, and (c) use of an ultrasonic generator.
Further, according to this known technique, a wafer supporting device is mounted in a housing, with the tank disposed at a lower lateral position of the housing for storing hydrofluoric acid acting as cleaning liquid. The tank and housing communicate with each other through a pipe including a valve. Hydrofluoric acid vapor is generated as noted above, which is supplied into the housing to dissolve and wash oxide films off the wafer surface.
Japanese Patent Publication Laying-Open No. 213127/1987 discloses a different cleaning technique. This technique is carried out by (1) supplying clean nitrogen gas N 2 into a treating chamber while spinning a wafer placed in the treating chamber, (2) in parallel with the above, supplying hydrogen fluoride gas HF, which is obtained by heating anhydrous hydrofluoric acid, and spraying superpure water into the treating chamber at the same time to produce hydrofluoric acid for removing oxide films from the wafer, (3) cleaning the wafer surface with jets of superpure water, and (4) spinning the wafer rapidly while introducing nitrogen gas to extract the liquid from and dry the wafer.
In both of the techniques disclosed in Patent Publications Laying-Open Nos. 173720/1987 and 213127/1987, the wafer before being dried is washed by supplying highly pure water vapor to the wafer surface and chamber walls or by spraying superpure water against the wafer. These techniques, however, have the drawback of leaving particles on the wafer surface in spite of the washing treatment.
In the technique disclosed in Patent Publication Laying-Open No. 173720/1987, an aerosol (mist) is formed along with the vapor by any one of the methods (a)-(c) of producing hydrofluoric acid vapor. That is, an aerosol is formed by boiling in the case of method (a), by formation of bubbles in method (b), and by cavitation in method (c).
Moreover, a space must be secured outside the housing to install the tank for storing hydrofluoric acid. This results in the disadvantage of enlarging the entire apparatus.
With such a wafer cleaning apparatus, it is necessary to prevent leakage of the vapor such as of hydrofluoric acid used in the cleaning treatment. Thus, seals must be provided not only for the housing but for the tank itself and connections of the pipe to the tank and housing. Such sealing structures are large and expensive.
In the technique disclosed in Patent Publication Laying-Open No. 213127/1987, the supply of superpure water and the direct supply to the wafer of the liquid hydrofluoric acid formed by dissolving hydrogen fluoride gas in the superpure water themselves result in adhesion of an aerosol to the wafer.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a method capable of cleaning wafers with high precision whereby the wafers are cleaned to a particle-free condition.
Another object of the invention is to provide an apparatus effective for practicing the above wafer cleaning method. Specifically, the invention intends to provide a cleaning treatment in which a wafer surface is cleaned with cleaning vapor while avoiding formation of colloidal silica at and adjacent the gas/liquid and gas/solid interfaces, and to provide a cleaning treatment accompanied by an etching process in which a wafer is uniformly etched in the absence of impurities which is made possible by eliminating the aerosol.
A further object of the present invention is to provide a compact cleaning apparatus with simplified seals for preventing leakage of cleaning vapor.
Other objects and advantages of the present invention will be apparent from the following description.
In order to achieve the above objects, the present invention provides a method of cleaning a wafer by supplying cleaning vapor to the wafer, comprising the steps of causing a solution to evaporate at a temperature below a boiling point to produce the cleaning vapor, and supplying the cleaning vapor to the wafer at a temperature above a dew point thereof to clean the wafer.
The wafer cleaning method of this invention includes a cleaning method in which, as will be described later, a cleaning treatment is not carried out with a cleaning solution. This is because the wafer quality is not affected by omitting a cleaning treatment with a cleaning solution in the absence of particles and metallic impurities from the wafer having undergone a plurality of treatments preceding a cleaning treatment with cleaning vapor. Such instances include the case where, in causing growth of a synthetic film or a natural oxide film, the core pipe of an oxidizing furnace, wafer pallets, piping for the treating gas and the like are formed of materials having no impurities, and the treating gas used has a high degree of purity on the order of nine 9s after the decimal point (purity of 99.999999999), and the case where, for a cleaning process preceding the growth of such synthetic or natural oxide film, transport mechanisms, a chamber and the like are formed of materials having no impurities, the treating gas used has a high degree of purity, and the wafer is passed to the next process in a cleanroom under the atmospheric condition of a highly pure inert gas.
In the wafer cleaning method using a cleaning solution, and in the wafer cleaning apparatus, which will be described later, the wafer is cleaned with a cleaning solution in a chamber separate from a chamber in which a vapor cleaning treatment is provided. However, the invention includes a wafer cleaning method in which the wafer is cleaned with cleaning vapor and with a cleaning solution in the same chamber. This single-chamber cleaning treatment is made possible without forming colloidal silica by cleaning the wafer with cleaning vapor, thereafter replacing the vapor in the chamber with a dry inert gas and cleaning the wafer with a cleaning solution in the dry atmosphere containing no aerosol.
Experiments have been conducted for arriving at the present invention, by way of researches on the cause of particle formation. Particulars of these experiments, a review and a summary will be set out hereinafter.
EXPERIMENTS
(A) Several droplets of a 25% aqueous solution of hydrofluoric acid were applied to a silicon wafer surface carrying 5,000 A of a thermal oxidation film of silicon (th-SiO 2 ). The way in which the thermal oxidation film was etched was observed through an optical microscope (see FIG. 4). The etching reaction of the thermal oxidation film progressed vertically and horizontally with respect to the silicon wafer. The vertical reaction is understood mainly as;
6HF+SiO.sub.2 →H.sub.2 SiF.sub.6 +2H.sub.2 O (1).
H 2 SiF 6 is hexafluorosilicic acid. Formation of bubbles was not detected.
Hydrofluoric acid spread fast horizontally. The horizontal etching reaction was such that surface areas of the thermal oxidation film around the droplets of hydrofluoric acid were first corroded into scale-like forms by mixed vapor HF/H 2 generating from the droplets. This reaction is as follows:
SiO.sub.2 +4HF+2H.sub.2 O→SiF.sub.4 +4H.sub.2 O (2)
where SiF 4 is silicon tetrafluoride (gas).
Hydrofluoric acid spreading horizontally causes vertical etching as expressed by the formula (1).
(B) Next, droplets of hydrofluoric acid were separately applied to a bare silicon surface revealed after the thermal oxidation film of silicon has been etched away completely by the mixed vapor HF/H 2 O. Changes taking place moment after moment were observed through the optical microscope (see FIG. 5).
The droplets became semispherical since the bare silicon surface completely stripped of the thermal oxidation film was hydrophobic. After a while, colloidal silica SiO 2 .nH 2 O (a silicon oxide in colloids) was gradually deposited on gas/liquid and gas/solid interfaces around the droplets.
The droplets gradually diminished while colloidal silica was deposited increasingly around the droplets. Meanwhile, relatively large colloidal particles were found afloat in the droplets.
Colloidal silica was in fine grain sizes up to about 0.625 μm. Aggregates of colloidal silica deposited formed spots known as blue hazes on the bare silicon surface. The deposition of colloidal silica was not limited to the gas/liquid and gas/solid interfaces but occurred on areas of the bare silicon surface surrounding the droplets as well. When a droplet having a diameter d was put on the silicon wafer, colloidal silica was rapidly deposited on the gas/solid interface over a range around the droplet about 4 times its diameter as shown in FIG. 5.
Colloidal silica was formed also on the droplet surface, i.e. the gas/liquid interface.
The incidence rate of colloidal silica was highest at both gas/solid and gas/liquid interfaces and became progressively lower farther away therefrom.
The reason for the formation of colloidal silica at the gas/solid interface shown in FIG. 5 is not clear. It appears, however, that colloidal silica was formed as a result of bonding between the moisture evaporating from the droplet surface and silicon tetrafluoride in the atmosphere.
As the droplet gradually diminished, colloidal silica was deposited in a certain amount around the droplet. When the droplet disappeared in the end, large colloidal particles which had been afloat in the droplet remained around what had been the center of the droplet. However, when the droplet was caused to evaporate at an increased rate, colloidal silica was deposited ultimately only around the peripheries, with no colloidal silica left in the center (see FIG. 6).
Such formation of colloidal silica was limited to areas contacting the atmosphere of the etching treatment, and did not take place in the wet areas covered by the droplets, i.e. at the liquid/solid interface.
(C) An experiment was conducted to check on the relationship to a rinsing treatment with deionized water (pure water).
Droplets of pure water were applied to a bare silicon surface after the natural oxide film was removed with hydrofluoric acid, and results were observed through the microscope. Colloidal silica was formed around the droplets applied to the bare silicon surface immediately after removal of the natural oxide film. However, colloidal silica was hardly formed on a bare silicon surface rinsed after removal of the natural oxide film.
Activating energy of the silicon surface is believed to lessen as a result of bonding between the silicon surface and various substances such as carbon present in the air.
Thus, colloidal silica can be formed during the period following removal of the natural oxide film by mixed vapor HF/H 2 O and before the bare silicon surface is covered by pure water, which presumably results in particles.
REVIEW
Colloidal silica is formed on portions of the bare silicon surface exposed to the atmosphere after being etched with hydrofluoric acid. Further, it has been found that colloidal silica is formed around the droplets and its incidence rate tends to lessen away from the gas/liquid and gas/solid interfaces. This shows that the formation of colloidal silica is closely related to the amount of moisture in the atmosphere. Colloidal silica is SiO 2 .nH 2 O which appears to be formed, if at all, when silicon tetrafluoride SiF 4 (gas) formed by the treatment with hydrofluoric acid reacts with moisture in the atmosphere as in the following formula (3):
3SiF.sub.4 +3H.sub.2 O→SiO.sub.2 H.sub.2 O+2H.sub.2 SiF.sub.6( 3)
In other words, the formation of colloidal silica is considered due to hydrolysis of silicon tetrafluoride SiF 4 (gas).
Silicon tetrafluoride may be formed by the reaction expressed by formula (2), as a result of corrosion of the bare silicon by vapor HF evaporating from the droplets of hydrofluoric acid, or as a result of decomposition of hexafluorosilicic acid in the droplets as H 2 SiF 6 →SiF 4 +2H 2 O. This silicon tetrafluoride and water vapor are considered to cause the hydrolysis expressed by formula (3) to produce and deposit colloidal silica. Another possible cause of colloidal silica formation is the silicon dissolved in hydrofluoric acid as expressed by the following formula:
2H.sup.+ +SiF.sub.6.sup.2- +60H.sup.- →SiO.sub.2 H.sub.2 O+6F.sup.- +3H.sub.2 O (4)
However, the above reaction takes place only at the gas/liquid interface and does not extend to regions around the droplets.
It appears, therefore, that the deposition of colloidal silica is promoted mainly by the hydrolytic effect of atmospheric moisture upon silicon tetrafluoride which results from etching of the silicon surface by hydrogen fluoride.
Colloidal silica is also fostered by the droplets adhering to the bare silicon surface stripped of the natural oxide film. Thus, mist or aerosol adhering to the surface will act as the core for promoting formation of colloidal silica.
SUMMARY
(a) The deposition of colloidal silica is promoted by the hydrolytic effect of atmospheric moisture upon silicon tetrafluoride resulting from etching of the silicon surface by hydrogen fluoride.
(b) Colloidal silica is deposited around the droplets adhering to the bare silicon surface stripped of the natural oxide film.
(c) No deposition of colloidal silica is found in the droplet-covered portions.
(d) Colloidal silica is deposited after the natural oxide film is etched away by hydrofluoric acid and the bare silicon surface becomes hydrophobic, particularly during the period following exposure of the bare silicon surface to the atmosphere until the bare silicon surface is covered by deionized water.
(e) The incidence rate of colloidal silica is highest at the gas/liquid and gas/solid interfaces and becomes progressively lower farther away therefrom.
(f) Colloidal silica is not formed on the bare silicon wafer surface in an active state especially where etching and rinsing treatments are carried out successively and the bare silicon surface is isolated from the atmosphere.
(g) Sizes of colloidal silica are on the order of 0.625 μm and its aggregates look like hazy spots to the naked eye.
It will be understood from the foregoing observations that, in order to prevent formation of colloidal silica, an attempt should be made to allow no aerosol (mist) to exit in the atmosphere for the cleaning process. For this purpose, it is important not to supply an aerosol to the silicon wafer and not to allow the cleaning vapor supplied to the silicon wafer to liquefy and form an aerosol.
These facts have been found through the experiments, and measures as set out hereunder have been taken on the basis of such findings to solve the problem.
The following cleaning liquids or solutions are available for use in the present invention:
[1] Sulfuric acid (H 2 SO 4 ), a mixture of sulfuric acid and hydrogen peroxide (H 2 O 2 ), fuming sulfuric acid (H 2 SO 4 +SO 3 +H 2 O 2 ), and an aqueous solution of sulfuric acid:
Vapors from these liquids are effective for eliminating organic and inorganic substances. An aqueous solution of sulfuric acid (H 2 SO 4 +H 2 O) having an azeotropic composition at 98.4% and a boiling point at 317° C. reacts with metallic impurities to form a sulfate, thereby dissolving and removing the metallic impurities.
[2] Nitric acid (HNO 3 ), fuming nitric acid (HNO 3 +NO 2 +H 2 O) containing nitric acid in a concentration of at least 86%, and an aqueous solution of nitric acid:
Vapors from these liquids react with metallic impurities to form nitrides, thereby dissolving and removing the metallic impurities. However, aluminum (Al), chromium (Cr) and iron (Fe) become passive. The silicon surface may be oxidized.
[3] A liquid mixture and an aqueous solution of nitric acid (HNO 3 ) and hydrogen halides (HF, HCl, etc.):
Vapors from these liquids react with metallic impurities for their dissolution and removal. Further, particles and metallic impurities are removable by a combination of oxidation by nitric acid and oxide decomposition by hydrogen halides.
[4] An aqueous solution of hydrogen fluoride (hydrofluoric acid) (HF+H 2 O), and a liquid mixture and an aqueous solution of hydrogen fluoride (HF) and alcohol (ROH):
Vapors from these liquids are effective for etching and removal of natural oxide films (SiOx), and react with metallic impurities to form fluorides for dissolution and removal thereof.
[5] a liquid mixture and an aqueous solution of hydrogen fluoride (HF) and hydrogen peroxide (H 2 O 2 ), and an liquid mixture and an aqueous solution of hydrogen fluoride (HF), alcohol (ROH) and hydrogen peroxide (H 2 O 2 ):
Vapors from these liquids are capable of removing particles and metallic impurities with oxidation by hydrogen peroxide of the silicon surface and decomposition by hydrogen fluoride of the oxides taking place simultaneously.
[6] An aqueous solution of hydrogen chloride (hydrochloric acid) (HCl+H 2 O), a liquid mixture and an aqueous solution of hydrogen chloride (HCl) and alcohol (ROH), a liquid mixture and an aqueous solution of hydrogen chloride (HCl) and hydrogen peroxide (H 2 O 2 ), and a liquid mixture and an aqueous solution of hydrogen chloride (HCl), alcohol (ROH) and hydrogen peroxide (H 2 O 2 ):
Vapors from these liquids react with metallic impurities and remove them in the form of chlorides.
[7] An aqueous solution of ammonia (NH 3 +H 2 O), and a liquid mixture and an aqueous solution of ammonia (NH 3 ) and alcohol (ROH):
Vapors from these liquids are capable of removing particles by utilizing that ammonia dissolves silicon compounds (i.e. etch silicon) to a minor extent.
[8] A liquid mixture and an aqueous solution of ammonia (NH 3 ) and hydrogen peroxide (H 2 O 2 ), and a liquid mixture and an aqueous solution of ammonia (NH 3 ), alcohol (ROH) and hydrogen peroxide (H 2 O 2 ):
Vapors from these liquids remove particles with etching of silicon by ammonia and oxidation by hydrogen peroxide. The wafer surface becomes oxidized and hydrophilic after the treatment.
[9] Choline ([(CH 3 ) 3 NC 2 H 4 OH]OH) and choline derivatives ([(C n H 2n+1 ) 4 N]OH), an aqueous solution of choline ([(CH 3 ) 3 NC 2 H 4 OH]OH+H 2 O), and a liquid mixture and an aqueous solution of choline ([(CH 3 ) 3 NC 2 H 4 OH]OH) and alcohol (ROH):
Vapors from these liquids remove particles with etching of silicon by choline.
[10] A liquid mixture and an aqueous solution of choline ([(CH 3 ) 3 NC 2 H 4 OH]OH) and hydrogen peroxide (H 2 O 2 ), and a liquid mixture and an aqueous solution of choline ([(CH 3 ) 3 NC 2 H 4 OH]OH), alcohol (ROH) and hydrogen peroxide (H 2 O 2 ):
Vapors from these liquids remove particles with etching of silicon by choline and oxidation by hydrogen peroxide. The wafer surface becomes oxidized and hydrophilic after the treatment.
According to the wafer cleaning method of the present invention, the cleaning vapor to be supplied to the wafer is produced by evaporating a cleaning solution at a temperature below its boiling point. In other words, the cleaning vapor is produced, without boiling the cleaning solution, by evaporating the solution from its surface in a molecular diffusive fashion tending to a balanced mass transfer at the gas/liquid interface. The cleaning treatment is carried out with such cleaning vapor at an atmospheric temperature above the dew point of the cleaning vapor, i.e. under the condition in which the saturation vapor pressure of the cleaning vapor exceeds its partial pressure, in order to avoid formation of an aerosol due to condensation of the cleaning vapor. This precludes the cause of formation of colloidal silica. Formation of an aerosol is prevented by producing the cleaning vapor at a temperature below the boiling point of the solution and maintaining the so produced vapor at a temperature above its dew point. This protects the wafer surface from contamination by impurities, formation of particles, adhesion of particles carried by an aerosol, and uneven etching results.
Thus, the vapor for cleaning the wafer is obtained in an aerosol-free state by evaporating the cleaning solution at a temperature below the boiling point. Moreover, the cleaning vapor is supplied to the wafer at a temperature above the dew point without allowing it to liquefy. This feature precludes the cause of colloidal silica formation due to an aerosol, thereby allowing an effective cleaning treatment with the cleaning vapor to provide the wafer with a clean surface. Where an etching process is included in the treatment, the wafer may be etched uniformly in the absence of impurities.
It is important to exclude an aerosol (mist) for prevention of colloidal silica. Water vapor itself is a gas and its presence will present no problem.
The present invention provides a wafer cleaning apparatus having a wafer supporting device for supporting a wafer under treatment, which is suited for practicing the above wafer cleaning method. This apparatus comprises a cleaning solution storage for storing a cleaning solution, a vapor generating section defined above the cleaning solution storage for evaporating the cleaning solution at a temperature below a boiling point thereof, and a vapor supply section for supplying cleaning vapor to the wafer supported by the wafer supporting device while adjusting the cleaning vapor to a temperature above a dew point thereof. The cleaning solution storage, vapor generating section, a wafer supporting position of the wafer supporting device and the vapor supply section are arranged in a housing to overlap one another in plan view and to lie vertically close to one another.
Preferably, at least the wafer supporting position of the wafer supporting device and the vapor supply section are enclosed in a double, inner and outer housing structure, and an exhaust control device is provided for controlling displacements such that a greater amount of gas is exhausted from an inner housing than from a space between the inner housing and an outer housing.
According to the wafer cleaning apparatus of this invention, the cleaning solution storage, vapor generating section, the wafer supporting position of the wafer supporting device and the vapor supply section are arranged in a housing to vertically overlap one another within a limited range. The housing may be sealed to prevent leakage of the cleaning vapor from the range from cleaning solution storage to vapor supply section.
The entire apparatus is formed compact since the cleaning solution storage, vapor generating section, the wafer supporting position of the wafer supporting device and the vapor supply section are arranged in a housing to vertically overlap one another within a limited range.
The seals applied to the housing alone are used to prevent leakage of the cleaning vapor from the range from cleaning solution storage to vapor supply section. Such construction can dispense with a special sealing arrangement as provided in the prior art where the cleaning solution storage for generating the cleaning vapor is disposed outside the housing. The simplified seals against vapor leakage as in the present invention have an advantage of economy.
With the wafer cleaning apparatus including the exhaust control device, the cleaning vapor having been supplied to the wafer is prevented from leakage by the double housing construction. In addition, controls are provided to exhaust a greater amount of gas from the inner housing than from the space between the inner and outer housings. The pressure within the inner housing thereby becomes lower than that of the space between the two housings, which results in suction of the gas from outside to inside of the inner housing to promote prevention of the cleaning vapor leaking outwardly of the apparatus.
Thus, since the wafer supporting position of the wafer supporting device and the vapor supply section are enclosed in the double housing structure, the cleaning vapor supplied to the wafer is effectively prevented from leaking outwardly.
Further, because of the difference in displacement for lowering the pressure inside the inner housing below the pressure in the space between the two housings, the outgoing cleaning vapor will not flow from the inner housing into the space between the two housings. This feature assures prevention of outward leakage of the cleaning vapor exhaust.
The foregoing wafer cleaning method may be made even more effective by transporting the cleaned wafer to a wet cleaning chamber where the wafer is cleaned with a further cleaning solution.
The cleaning solution or liquid used in the wet cleaning chamber is not limited to pure water (deionized water) but may be selected from ammonium hydrogen peroxide, hydrochloric hydrogen peroxide, choline and choline derivatives. The wafer may be or may not be spun during the cleaning treatment in the wet cleaning chamber.
According to this modified cleaning method, the cleaning solution used in the wet cleaning chamber will never mix into the cleaning vapor since the wafer having been cleaned with the cleaning vapor is transferred to the wet cleaning chamber. Further, formation of colloidal silica is prevented by the feature that the cleaning solution, which is not supplied in mist form to the wafer, entirely covers the wafer surface having been cleaned with the cleaning vapor.
Since the wafer, which has been cleaned with the cleaning vapor containing no aerosol, is transferred to the wet cleaning chamber to be cleaned with the cleaning solution, the cleaning solution will never mix into the cleaning vapor and colloidal silica formation due to the treatment with the cleaning solution is avoided. A clean-surfaced wafer may be obtained also where the wafer is cleaned in a series of treatments with the cleaning vapor and cleaning solution. Where an etching process is involved, the wafer may be etched uniformly in the absence of impurities. Thus, even where particles remain after the vapor cleaning treatment, such particles may be removed.
The modified cleaning method as noted above may be carried out effectively by a wafer cleaning apparatus according to the present invention which comprises a vapor generating section for evaporating a cleaning solution at a temperature below a boiling point thereof, a dry cleaning chamber including a temperature controlling device for adjusting cleaning vapor supplied from the vapor generating section to a temperature above a dew point thereof, the dry cleaning chamber being operable to clean the wafer as placed therein with the cleaning vapor having the adjusted temperature, a wafer transport mechanism for transporting the wafer after being cleaned from the dry cleaning chamber, and a wet cleaning chamber separated from the dry cleaning chamber and including a device for supplying a further cleaning solution, the wet cleaning chamber receiving the wafer transported by the wafer transport mechanism to clean the wafer by supplying the further cleaning solution thereto.
According to this wafer cleaning apparatus, the cleaning vapor is produced in the vapor generating section by evaporating the cleaning solution at a temperature below its boiling point. In other words, the cleaning vapor is produced, without boiling the cleaning solution, by evaporating the solution from its surface in a molecular diffusive fashion tending to a balanced mass transfer at the gas/liquid interface. The dry cleaning chamber includes a temperature controlling device for maintaining the cleaning vapor to a temperature above its dew point to prevent the vapor from liquefying into an aerosol within the dry cleaning chamber. In addition, the dry cleaning chamber is separated from the wet cleaning chamber to preclude the possibility that the cleaning solution used in the wet cleaning chamber will mix into the cleaning vapor in the dry cleaning chamber. Thus, the cleaning treatment is carried out with the cleaning vapor in an aerosol-free condition, thereby preventing formation of colloidal silica.
When the wafer as cleaned above is removed from the dry cleaning chamber by the wafer transport mechanism, chemicals such as silicon tetrafluoride which may cause formation of colloidal silica just leave the wafer surface instead of remaining thereon. Once the wafer is removed from the dry cleaning chamber, there will no longer be a contact with silicon tetrafluoride. The wafer is now exposed to air in the cleanroom which has a high degree of purity and contains no aerosol. Thus, formation of colloidal silica is prevented at this stage as well. In the wet cleaning chamber the wafer is cleaned as entirely covered by the cleaning solution, which is also effective to prevent formation of colloidal silica.
Thus, the cleaning vapor formed in the vapor generating section contains no aerosol, and is maintained at a temperature above the dew point by the temperature controlling device. The dry cleaning chamber is separated from the wet cleaning chamber to preclude the possibility of the cleaning solution mixing into the cleaning vapor in the dry cleaning chamber. Consequently, the wafer is cleaned with the cleaning vapor in an aerosol-free condition.
In the wet cleaning chamber the wafer is cleaned as entirely covered by the cleaning solution to prevent formation of colloidal silica.
All these features combine to realize a cleaning apparatus effective for successively cleaning the wafer with the cleaning vapor and with the cleaning solution without forming colloidal silica.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a wafer cleaning apparatus in a first embodiment of the present invention,
FIG. 2 is a graph of composition-to-temperature characteristic curves, which characteristics appear under ambient pressure,
FIG. 3 is a sectional view of a wafer cleaning apparatus in a second embodiment of the invention,
FIGS. 4 through 8 relate to the experiments conducted by Inventors, in which:
FIG. 4 is a sectional view showing the way in which a thermal oxidation layer is etched,
FIG. 5 is a perspective view showing the way in which colloidal silica is deposited around a droplet of water or other liquid on bare silicon,
FIG. 6 is a perspective view showing colloidal silica remaining deposited after the droplet is evaporated,
FIG. 7 is an explanatory view shoing the way in which etching progresses, and
FIG. 8 is an explanatory view showing the way in which water droplets adhere to bare silicon,
FIG. 9 is a schematic view of a wafer cleaning apparatus in a third embodiment of the invention,
FIG. 10 is a schematic view of a wafer cleaning apparatus in a variation of the invention,
FIG. 11 is a graph showing vapor pressures of a mixture of hydrogen fluoride HF and water H 2 O,
FIG. 12 is a schematic view in vertical section of a wafer cleaning apparatus in a fourth embodiment of the invention,
FIG. 13 is an enlarged sectional view of a principal portion of the apparatus shown in FIG. 12, and
FIG. 14 is a schematic view in vertical section of a wafer cleaning apparatus in a fifth embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of the present invention will be described in detail hereinafter with reference to the drawings.
FIRST EMBODIMENT
FIG. 1 is a sectional view of a wafer cleaning apparatus in a first embodiment of the invention. Reference numeral 1 denotes a storage tank for storing a liquid mixture of hydrofluoric acid HF and pure water H 2 O, i.e. a cleaning solution in a quasiazeotropic state to be described later, quasiazeotropy being detailed in Japanese Patent Application Serial No. 1-109292 (corresponding to U.S. Patent Application filed Apr. 20, 1990. A pipe 3 including anagitating pump 2 is connected to a bottom position and a lateral position of the storage tank 1.
A cleaning solution supply pipe 4 is connected to the storage tank 1. This supply pipe 4 extends from a different tank (not shown) for storing the cleaning solution in the azeotropic state (manufactured by Morita Kagaku Kogyo Co., Ltd.). The supply pipe 4 has a switch valve 5 which is opened to replenish the storage tank 1 when a storage level of the cleaning solution falls below a position detected by a liquid level gauge 6.
The storage tank 1 accommodates a heater 7 for heating the cleaning solution, a cooling pipe 8 for cooling the solution, and a temperature sensor 9 for measuring temperature of the solution stored in the tank 1. The temperature sensor 9 is connected to a temperature control unit 10 to which an electromagnetic valve 11 mounted on the cooling pipe 8 and the heater 7 are also connected.
While the agitating pump 2 acts to uniform the temperature of the cleaning solution stored, the temperature control unit 10 controls the heater 7 and electromagnetic valve 11 in response to the temperature detected by the temperature sensor 9. As a result, the cleaning solution stored in the tank 1 is maintained at 30° C. which is an azeotropic temperature to be described later (which temperature corresponds to an azeotropic concentration of 39% at 760 mmHg as described later).
More particularly, when the temperature of the cleaning solution falls as a result of replenishment, for example, the heater 7 is driven to heat the solution in the storage tank 1 up to the azeotropic temperature of 30° C. Conversely, when the temperature of the solution exceeds this azeotropic temperature, the electromagnetic valve 11 is opened to cause cooling water to flow through the cooling pipe 8 for lowering the solution temperature.
These controls maintain the cleaning solution, which is a liquid mixture of hydrofluoric acid and pure water, at the azeotropic temperature to cause evaporation below a boiling point.
Further, a nitrogen gas supply pipe 14 is connected to the storage tank 1 for supplying nitrogen gas N 2 acting as a carrier. This supply pipe 14 includes a flow controller 12 and an electromagnetic valve 13, with a nozzle 14a having a porous plate attached to an extreme end of the pipe 14 located inside the storage tank 1. Thus, an upper, vapor generating region 15 of the tank 1 has a uniform pressure distribution.
A vapor supply pipe 17 is connected to the storage tank 1 for transmitting cleaning vapor diluted with the carrier nitrogen gas N 2 from the vapor generating region 15 to a dry cleaning chamber 16.
The storage tank 1 has a pressure sensor 18 for measuring pressure of the atmosphere including the cleaning vapor in the vapor generating region 15. The pressure sensor 18 is connected to a pressure control unit 19 which is connected to the electromagnetic valve 13 on the nitrogen gas supply pipe 14. The pressure control unit 19 operates the electromagnetic valve 13 in response to the pressure measured by the pressure sensor 18, thereby to control the nitrogen gas supply for maintaining the atmosphere in the vapor generating region 15 at the ambient pressure of 760 mmHg.
A forward portion of the nitrogen gas supply pipe 14, the vapor generating region 15 of storage tank 1 and vapor supply pipe 17 are enclosed in an outer pipe 20 formed of a heat insulating material. The outer pipe 20 contains hot water, and a bypass pipe 22 having a pump 21 extends between an upstream position and a downstream position of the outer pipe 20. The bypass pipe 22 includes a heater 23 mounted in an intermediate position thereof.
This construction recirculates hot water heated by the heater 23 to an appropriate temperature (50° C., for example). As a result, the vapor of the cleaning solution which comprises a vaporous mixture of hydrogen fluoride gas HF and pure water vapor H 2 O and which flows from the vapor generating region 15 into the vapor supply pipe 17 is maintained at a temperature above the dew point. In the cleaning vapor, hydrogen fluoride gas is maintained at the azeotropic concentration of 39.4% under the conditions of 760 mmHg and 30° C.
That is, as detailed in Japanese Patent Application No. 1-09292 (corresponding to U.S. Patent Application filed Apr. 20, 1990), the saturated vapor pressures of the cleaning vapor in the atmosphere and each component of the vapor are maintained above their respective partial pressures to prevent condensation or liquefaction of the cleaning vapor and components thereof.
At this time, the sum (PHF+PH2O) of the partial pressures of hydrogen fluoride gas and pure water vapor is 18 mmHg, and the partial pressure of nitrogen gas is 742 mmHG.
FIG. 11 is a graph showing vapor pressures of the liquid mixture of hydrogen fluoride HF and water H 2 O. The horizontal axis represents partial pressure PHF of fluoric hydride, while the vertical axis represents the total pressure, i.e. the sum (PHF+PH2O) of partial pressure PHF of hydrogen fluoride and partial pressure PH2O of water vapor. The relations between partial pressure PHF and total pressure PHF+PH2O are shown by using temperature T as a parameter.
The oblique straight lines indicate composition ratios (molar fractions) of hydrogen fluoride with respect to the entire liquid mixture.
According to this graph, the vaporous mixture of hydrogen fluoride gas and pure water vapor does not become condensed or liquefied if the vapor produced at the azeotropic temperature of 30° C. under the foregoing conditions is maintained at temperatures above 30° C. On the other hand, the vaporous mixture of hydrogen fluoride gas and pure water vapor becomes liquefied if the temperature of the vapor having the total pressure of 760 mmHg, with the mixed gas of hydrogen fluoride gas and pure water vapor at the 18 mmHg partial pressure and nitrogen gas at the 742 mmHg partial pressure, falls below 30° C. when hydrogen fluoride is at the azeotropic concentration of 39.4% described later.
No aerosol is included in such cleaning vapor composed of hydrogen fluoride gas and pure water vapor. This cleaning water is generated in the vapor generating region 15 by a vapor generator which comprises the construction including the heater 7, cooling pipe 8, temperature sensor 9, temperature control unit 10 and electromagnetic valve 11 for maintaining the temperature of the cleaning solution at 30° C., and the construction including the electromagnetic valve 13, nitrogen gas supply pipe 14, pressure sensor 18 and pressure control unit 19 for maintaining the atmospheric pressure in the storage tank 1 at 760 mmHg.
Pseudo-azeotrope will now be described.
FIG. 2 shows composition-to-temperature characteristics occurring when the total pressure PHF+PH2O of partial pressure PHF of hydrogen fluoride HF and partial pressure PH2O of water H 2 O is 760 mmHg. The horizontal axis represents composition ratio or concentration (%) of hydrogen fluoride, and the vertical axis represents temperature (° C.).
In FIG. 2, the liquid phase curve and vapor phase curve of the liquid mixture of hydrogen fluoride and water at 760 mmHg meet at 111.4° C. This is an azeotropic point at which the concentration of hydrogen fluoride is 37.73%.
Azeotropic conditions are satisfied where the storage tank 1 stores a cleaning solution composed of hydrogen fluoride having the 37.73% concentration and pure water in 62.27% (=100-37.73%), the atmospheric pressure in the storage tank 1 is maintained at 760 mmHg and the temperature of the cleaning solution at 111.4° C. Then, the cleaning vapor has the same composition ratio HF:H 2 O=37.73:62.27 as the cleaning solution, and this ratio is invariable all the time even if the cleaning solution diminishes with progress of its evaporation.
However, the temperature of 111.4° C. is rather high and, to promote safety, the cleaning solution should preferably be caused to evaporate at a lower temperature. Where, for example, the evaporation temperature of 30° C. is desired, the azeotropic conditions are met by the pressure PHF+PH2O at 18 mmHg and the concentration of hydrogen fluoride acid HF at 39.4%. A pressure reduction is required to set the atmospheric gas pressure PHF+PH2O to 18 mmHg. It is quasi-azeotrope that eliminates the need for the pressure reduction and allows evaporation to take place in the atmosphere at 760 mmHg ambient pressure.
Thus, the cleaning solution comprising a mixture of hydrogen fluoride in 39.4% and pure water in 60.6% is supplied into the storage tank 1. The temperature of the cleaning solution is maintained at 30° C. by temperature adjustment effected through the heater 7, cooling pipe 8, temperature sensor 9 and temperature control unit 10.
The cleaning solution evaporates under the 760 mmHg atmospheric pressure in the storage tank 1, which is the total of partial pressures PHF, PH2O and PN2 of hydrogen fluoride gas, water vapor and nitrogen gas. When the atmospheric pressure deviates from 760 mmHg, pressure adjustment is effected through the pressure sensor 18, electromagnetic valve 13 and pressure control unit 19 to maintain the pressure at 760 mmHg.
Nitrogen gas having a partial pressure of 742 mmHg (=760-18 mmHg) is supplied through the nitrogen gas supply pipe 14 into the storage tank 1 to act as an atmospheric and carrier gas.
The cleaning solution in this case has a composition ratio HF:H 2 O=39.4:60.6. On the other hand, the atmospheric gas has a composition ratio calculated as;
HF:H.sub.2 O:N.sub.2 =5.21:8.00:86.79.
(The above proportional expression is based on HF+H 2 O+N 2 =100. If based on HF+H 2 O+N 2 =760, the expression reads HF:H 2 O:N 2 =7.09:10.91:742.) This composition ratio differs from that of the cleaning solution.
However, what is important to the wafer cleaning treatment is not the composition ratio of the entire atmospheric gas but the composition ratio between hydrogen fluoride gas and water vapor, which is;
HF:H.sub.2 O=5.21:8.00=39.4:60.6.
(When based on HF+H 2 O+N 2 =760 also, the expression reads HF:H 2 O=7.09:10.91=39.4:60.6.) This agrees with the composition ratio of the cleaning solution, which means quasi-azeotrope.
Consequently, the cleaning vapor supplied to the dry cleaning chamber 16 to be described next has a composition ratio maintained constant all the time. Besides, the cleaning vapor can be generated at ambient pressure and at a temperature as low as 30° C., which promotes safety and requires no pressure reduction.
What is more important to the present invention is that the cleaning solution is allowed to evaporate at a temperature below the boiling point. This feature has the advantage of producing no aerosol since the cleaning solution evaporates from its surface without being boiled.
The construction of dry cleaning chamber 16 will be described next.
A wafer treating chamber 24 in the form of a bottomed cylinder houses a mechanical chuck 25 rotatable on a horizontal plane with a semiconductor or other wafer W mounted thereon. The chuck for supporting the wafer W may comprise a known vacuum suction chuck instead of the mechanical chuck. It may include a heater therein for heating the wafer W as sucked by a vacuum to a predetermined temperature. The mechanical chuck 25 has a rotary shaft 26 operatively connected to an electric motor 27, so that the wafer W placed on the chuck 25 is spun on a vertical axis.
The wafer treating chamber 24 has a top opening closed by a cup-shaped cover 28 including a tapered peripheral wall, a chamber 29 integral and watertight with a lower end of the peripheral wall, and a top board integral and watertight with an upper end of the peripheral wall. A hot water supply tube 30 and a hot water drain tube 31 extend into the cover 28 through the peripheral wall to constantly maintain hot water of a fixed temperature (e.g. 50° C.) in the cover 28. Thus, the cover 28 defines a thermostatic hot water tank 32 for maintaining the interior of the cover 28 at the fixed temperature.
The thermostatic hot water tank 32 accommodates an aspirator 33 to which are connected the vapor supply pipe 17 for supplying the cleaning vapor composed of hydrogen fluoride gas, water vapor and nitrogen gas for etching and cleaning the wafer W, a carrier gas supply tube 34 for supplying nitrogen gas acting as carrier gas, and a vapor supply tube 35 for supplying the cleaning vapor to the chamber 29. The cleaning vapor diluted with the carrier gas is supplied into the chamber 29 as drawn by a negative pressure produced by flows of the carrier gas.
The vapor supply pipe 17, aspirator 33 and vapor supply tube 35 are placed in the thermostatic hot water tank 32 in order to control the temperature of the cleaning vapor to be above the dew point for prevention of its liquefaction or formation of an aerosol. In this sense, the thermostatic hot water tank 32, and the combination of outer pipe 20, pump 21, bypass pipe 22 and heater 23 for effecting temperature control of the vapor supply pipe 17 adjacent the cleaning solution storage tank 1 constitute the temperature control means of this invention.
The chamber 29 includes a gas inlet at its peripheral wall position and at an angle (e.g. 30°) to the radial direction, and a porous plate 36 defining a vapor supply section over a lower opening area. The cleaning vapor flowing into the chamber 29 through the slant gas inlet forms a vortex in the chamber 29, with the amount of flow increasing from center to periphery because of the centrifugal force. Consequently, the amount of vapor flowing out through the porous plate 36 is the greater toward the peripheries when the mechanical chuck 25 stands still. The rotation of the chuck 25 for spinning the wafer W supported thereon generates horizontal vapor flows, producing a negative pressure around the center. This increases the amount of vapor flow through center regions of the porous plate. As a result, the cleaning vapor is equalized in flowing out through the entire porous plate 36 to be directed evenly over the surface of wafer W.
The cup-shaped cover 28 is vertically movable with the chamber 29 and, when in a lowered position, rests on a packing along an upper edge of the wafer treating chamber 24 to place the latter in a gastight condition. Air cylinders 37 are provided as a mechanism for raising and lowering the cover 28.
The wafer treating chamber 24, cup-shaped cover 28 and the like constitute a main treating assembly which defines a double chamber construction with an outer housing 38. The housing 38 includes a wafer inlet 38a and a wafer outlet 38b level with the mechanical chuck 25, which are opened and closed by shutters not shown, as disclosed in U.S. patent application Ser. No. 642,014.
Flexion arm type wafer transport mechanisms 39 and 40 are disposed outside the housing 38 adjacent the inlet 38a and outlet 38b, respectively. With the cover 28 raised to open the wafer treating chamber 24, the wafer W as suction-supported by the transport mechanism 39 is delivered through the inlet 38a into the housing 38 and placed on the chuck 23. The wafer W may be removed likewise from the chunk 23 and out of the housing 38 through the outlet 38b. Such wafer transport mechanisms are disclosed in Japanese Utility Model Publication Laying-Open No. 176548/1985 (U.S. patent application Ser. No. 462,014), for example.
Numeral 41 denotes an exhaust pipe connected to the treating chamber 24. Numeral 42 denotes an exhaust pipe connected to the housing 38.
The way in which the wafer cleaning apparatus operates will be described next.
In the dry cleaning chamber 16, hot water is supplied at the fixed temperature (50° C.) through the hot water supply tube 30. The hot water is cooled through a heat exchange and exhausted through the exhaust tube 31. Thus, the temperature in the thermostatic hot water tank 32 is maintained constant.
The wafer inlet 38a is opened, and the air cylinders 37 are extended to raise the cover 28 and secure a space between cover 28 and mechanical chunk 25 for entry of the wafer transport mechanism 39. Wafer W is placed on and held tight by vacuum suction to the transport mechanism 39, which is then extended to deliver the wafer W through the inlet 38a into the housing 38 and onto the mechanical chuck 25. Thereafter the transport mechanism 39 is flexed to retract through the inlet 38a, and the inlet 38a is closed.
The air cylinders 37 are contracted to lower the cover 28 into pressure contact with the wafer treating chamber 24 to close the latter. Next, the electric motor 27 is driven to spin the chuck 25 and wafer W together. The carrier gas is fed through the carrier gas supply tube 34 to the aspirator 33 to produce a negative pressure. As a result, the aspirator 33 draws in the cleaning vapor composed in the fixed ratio of hydrogen fluoride gas, pure water vapor and nitrogen gas and containing no aerosol in the quasiazeotropic state, from the vapor generating region 15 of the storage tank 1 through the vapor supply pipe 17. It will be understood that the cleaning vapor will nonetheless flow into the chamber 29 without using the aspirator 33.
At this time, the cleaning vapor flowing through the vapor supply pipe 17 is maintained at a predetermined temperature above its dew point, and thus prevented from liquefaction, by the hot water heated by the heater 23 and recirculated by the pump 21. When flowing through the forward portion of the vapor supply pipe 17, aspirator 33 and vapor supply tube 35, the cleaning vapor is prevented from liquefaction, hence producing no aerosol, by the hot water in the thermostatic hot water tank 32.
The cleaning vapor diluted with the carrier gas in the aspirator 33 is supplied to the chamber 29 through the vapor supply tube 35 and slant gas inlet.
The cleaning vapor jetting at an angle into the chamber 29 forms a vortex in the chamber 29, circulating in a progressively greater amount from center to periphery and passing through the porous plate 36 to be supplied to the wafer W. The centrifugal force generated by the spin of the wafer W supported on the chunk 25 produces radially outward vapor flows.
By suitably selecting a flow rate of the cleaning vapor supplied and a rotating rate of the chunk 25, balance may be obtained between the negative pressure resulting from the vapor flows under the centrifugal force and the vapor flows descending from the porous plate 36, whereby the wafer W is subjected to a uniform vapor flow. This allows the thermal oxidation film of silicon on the wafer W to be etched uniformly over the entire surface, resulting in a flat profile.
In addition, since the cleaning vapor containing no aerosol is suppled and the temperature control is provided in the course of vapor supply to prevent aerosol formation, the etching treatment may be carried out for the wafer W in the condition that precludes formation of colloidal silica.
Upon completion of a required etching process, the supply of cleaning vapor is stopped and the electric motor 27 is switched off. The interiors of wafer treating chamber 24 and housing 38 are purged through the exhaust pipes 41 and 42. Then the air cylinders 37 are extended to raise the cover 28 and open the treating chamber 24. The wafer outlet 38b is opened, and the wafer transport mechanism 40 is extended to pick up the wafer W and flexed to transport the wafer W outwardly through the outlet 38b. Finally, the outlet 38b is closed.
SECOND EMBODIMENT
FIG. 3 is a sectional view of a second embodiment which additionally comprises a wet cleaning chamber 60 disposed next to the dry cleaning chamber 16. The wafer W having been cleaned with the cleaning vapor is delivered to the wet cleaning chamber 60 by the wafer transport mechanism 40 for a cleaning treatment with a cleaning solution or cleaning liquids.
The dry cleaning chamber 16 is identical to that already described, and like reference numerals are affixed to like components without repeating the description.
The wet cleaning chamber 60 will be described hereinafter.
A cleaning tank 61 houses a spin chuck 63 driven by an electric motor 62, with the wafer W held thereon by suction. A nozzle 64 is provided for spraying pure water H 2 O, and a nozzle 65 for spraying a cleaning chemical to the wafer W. The cleaning tank 61 further houses a cover 66 for preventing the water and chemical from scattering and for allowing smooth downflow thereof. The cover 66 is vertically movable by air cylinders 67 disposed under the cleaning tank 61. Elongate capillary nozzles, as disclosed in U.S. patent application Ser. No. 3983,408, consititue the nozzles 64 and 65, respectively.
The combination of nozzle 64 for spraying pure water and nozzle 65 for spraying the cleaning chemical to the wafer W corresponds to a cleaning solution supply mechanism.
Numeral 68 denotes a pure water storage tank, 69 a pump associated therewith, 70 a chemical storage tank, 71 a pump associated therewith, 72 an exhaust gas pipe, 73 an exhaust liquid pipe, and 74 a flexion arm type wafer transport mechanism. The cleaning solution used here comprise the mixture of pure water and the cleaning chemical. The cleaning chemical may be selected from ammonium hydrogen peroxide, hydrochloric hydrogen peroxide, choline and choline derivatives.
In the second embodiment, silicon tetrafluoride SiF 4 which causes formation of colloidal silica only volatilizes from the surfaces of etched wafer W during transfer of the wafer W from the dry cleaning chamber 16 to the wet cleaning chamber 60. Further, formation of colloidal silica is prevented since the wafer W is placed in a cleanroom having a high degree of cleanliness and containing no aerosol.
The dry cleaning chamber 16 is separated from the wet cleaning chamber 60, hence the cleaning liquids sprayed into the wet cleaning chamber 60 will never enter the wafer treating chamber 24 in the form of mist.
Consequently, excellent etching results are obtained with no particles remaining on the wafer W.
OPERATION
The way in which the wet cleaning chamber 60 in the second embodiment operates will be described next.
In the wet cleaning chamber 60, a wafer inlet 61a is opened with the cover 66 lowered by contracting the air cylinders 67. The wafer W having been cleaned with the cleaning vapor in the dry cleaning chamber 16 is transferred to the spin chunck 63 by the wafer transport mechanism 40. After the transport mechanism 40 is retracted, the inlet 61a is closed. The air cylinders 67 are extended to raise the cover 66, and then the pump 70 is driven to supply the cleaning chemical such as choline through the nozzle 65 to the wafer W for a primary cleaning treatment. Thereafter the pump 69 is driven to supply pure water through the nozzle 64 to the wafer W for a secondary cleaning treatment.
Since the nozzles 64 and 65 comprise elongate capillary nozzles, a bare silicon surface of the wafer W may be coated all over in one effort with the chemical and pure water, thereby preventing formation of colloidal silica.
The cover 66 has a smooth construction for promoting downflow of the cleaning liquids. This prevents droplets from remaining on the cover 66, and allows the cleaning liquids after use to be drained smoothly down the liquid exhaust pipe 73, thereby preventing the liquids from remaining in the cleaning tank 61. By enclosing the wafer W in the cover 66, the mist on inside walls of the cleaning tank 61 is prevented from adhering to the wafer W.
After a required cleaning treatment is completed, the interior of the cleaning tank 61 is purged through the exhaust gas pipe 72 and the spin chuck 63 is rotated at high speed to scatter the cleaning liquids off the wafer W and dry the wafer W.
After the drying process, the cover 66 is lowered and the cleaned wafer W is removed through a wafer outlet 61b by the transport mechanism 74.
Bacteria, a cause of particles, could be bred in pure water within the nozzle 64 and piping connected thereto during non-cleaning periods. It is therefore desirable to keep pure water flowing from the nozzle 64 all the time to avoid the breeding of bacteria.
In the second embodiment, the wafer W is cleaned and dried in the same treating chamber 60. However, a separate chamber may be provided exclusively for drying purposes.
Further, in the second embodiment, the wafer W is etched and cleaned in the separate treating chambers 16 and 60. However, etching and cleaning may be carried out in the same chamber as long as the wafer W is completely dried after the cleaning treatment. This is because colloidal silica is not formed if a perfectly dry condition is met in the etching treatment. It is, however, desirable to provide the separate chambers 16 and 60 since a long time is consumed to attain a perfectly dry condition.
The wet cleaning chamber 60 may be the type to immerse the wafer W in pure water instead of spraying pure water to the wafer W in the cleaning tank 61.
THIRD EMBODIMENT
Apart from the experiments described hereinbefore, Inventors have carried out further experiments to check how particles are formed by organic contamination. Results show that it is highly advantageous to eliminate any organic contamination beforehand for preventing formation of colloidal silica.
EXPERIMENT
As shown in FIG. 7, a silicon wafer W was set in a vertical posture and a vapor mixture of hydrogen fluoride and pure water was supplied upwardly to a surface of the wafer W. Then observation was made of etching of a thermal oxidation film of silicon th-SiO 2 on the wafer surface. Bare silicon Si was exposed from a lower position upward since the etching rate reduced from bottom to top. The boundary between bare silicon and thermal oxidation film shifted successively upward as a-b, c-d, e-f, g-h and i-j until finally the thermal oxidation film was eliminated. This reaction is expressed as follows:
6HF+SiO.sub.2 →H.sub.2 SiF.sub.6 +2H.sub.2 O (5)
where H 2 SiF 6 is hexafluorosilicic acid. Water was formed in the course of this reaction. As shown in FIG. 8, the water thus formed collects as droplets at the boundary between bare silicon Si and thermal oxidation film th-SiO 2 , which move upward with progress of the etching.
When there was organic contamination on the surface of thermal oxidation film or when etching progressed in varied directions, part of the thermal oxidation film was left in the form of islands and water droplets remained on boundaries between such film islands and bare silicon.
The residual droplets contained hexafluorosilicic acid H 2 SiF 6 and reacted as follows:
H.sub.2 SiF.sub.6 →SiF.sub.4 +2HF (6)
3SiF.sub.4 +4H.sub.2 O→SiO.sub.2.2H.sub.2 O+2H.sub.2 SiF.sub.6(7).
As a result, colloidal silica SiO 2 2H 2 O was formed on bare silicon around the droplets.
In order to prevent formation of colloidal silica, therefore, care must be taken for removal of organic contamination from the surface of thermal oxidation film and for fixing the etching direction.
In the first embodiment, the vapor mixture flows into the chamber 29 through the slant gas inlet, which results in influx through the porous plate 36 in the greater amount toward the peripheries. This is counterbalanced by the horizontal gas flows generated by spins of the wafer W supported on the mechanical chuck 25. With these horizontal gas flows, the atmospheric pressure becomes progressively higher away from the spin axis of the wafer. Consequently, the vapor flowing through the porous plate 36 is uniformly distributed over the entire surface of wafer W, thereby fixing the direction of etching progress. This leaves the question of organic contamination.
A cleaning treatment using ultraviolet radiation and ozone supply is known to be effective for elimination of organic contamination. Having this fact in view, in the third embodiment, as shown in FIG. 9, an ultraviolet/ozone (UV/O 3 ) cleaning chamber 80 is provided opposite the dry cleaning chamber 16 of the first embodiment across the wafer transport mechanism 39. An additional wafer transport mechanism 81 is also provided to deliver wafer W into the ultraviolet/ozone cleaning chamber 80.
Numeral 82 denotes ultraviolet lamps acting as ultraviolet radiator means, 83 an ozone spray nozzle acting as ozone spray means, 84 a spin chuck acting as wafer support means, and 85 an electric motor.
In the other aspects of construction this embodiment is the same as the first and second embodiments.
Preparatory to the treatment in the dry cleaning chamber 16, organic contamination is eliminated from the wafer W in the ultraviolet/ozone cleaning chamber 80. This process prevents droplets from remaining in island forms on the bare silicon surface owing to organic contamination, thereby eliminating the possibility of formation of colloidal silica in the etching and cleaning treaments.
VARIATION
There will be described below a variation for the apparatus for producing and supplying the cleaning azeotropic mixture solution of hydrogen fluoride HF and pure water H 2 O mixed in the ratio of 37.73:62.27%, the apparatus being useful where the azeotropic mixture solution described previously is not available.
Referring to FIG. 10 which is a sectional view of the apparatus, a hydrofluoric acid supplying device 106 comprises a hydrofluoric acid storage tank 101 storing an aqueous solution about 50% in concentration of hydrofluoric acid which is commercially available and acts as hydrogen halide for use in the cleaning treatment, a nitrogen gas supply pipe 102 and a valve 103 for supplying nitrogen gas N 2 under pressure to force hydrofluoric acid out of the storage tank 101, a hydrofluoric acid supply pipe 104 for transmitting hydrofluoric acid, and an electromagnetic valve 105 mounted on the hydrofluoric acid supply pipe 104.
A pure water supplying device 111 comprises a pure water storage tank 107 storing pure water H 2 O, a pump 108 for transmitting the pure water under pressure from the storage tank 107, a pure water supply pipe 109, and an electromagnetic valve 110 mounted on the pure water supply pipe 109.
The hydrofluoric acid supply pipe 104 and pure water supply pipe 109 are connected to a cleaning solution storage tank 112. The storage tank 112 receives hydrofluoric acid and pure water and stores the cleaning solution formed by mixing the two liquids.
Further, a bypass pipe 114 including an agitating pump 113 is connected to the cleaning solution storage tank 112 for agitating and mixing hydrofluoric acid and pure water therein.
The cleaning solution storage tank 112 includes a concentration sensor 115 such as a conductivity meter or an ultrasonic concentration meter for detecting concentration of the cleaning solution, an upper level sensor 116 and a lower level sensor 117. The concentration sensor 115, upper level sensor 116 and lower level sensors 117 are all connected to a replenish control unit 118. The replenish control unit 118 is connected to the electromagnetic valve 105 of hydrofluoric acid supply pipe 104, pump 108, electromagnetic valve 110 of pure water supply pipe 109 and to an electromagnetic valve 120 mounted on a drain pipe 119 of the cleaning solution storage tank 112. These components constitute a concentration controlling device 121 for replenishing the cleaning solution storage tank 112 with hydrofluoric acid and pure water under the control based on the concentration detected by the concentration sensor 115, thereby to maintain the cleaning solution stored in the storage tank 112 at the quasi-azeotropic concentration of 39.4% (this percentage being one example).
Specifically, the hydrofluoric acid storage tank 101 is pressurized by opening the electromagnetic valve 103 to supply nitrogen gas N 2 through the nitrogen gas supply pipe 102. At this time the electromagnetic valve 11 105 is opened to allow hydrofluoric acid to be supplied through the hydrofluoric acid supply pipe 104 to the cleaning solution storage tank 112. When hydrofluoric acid is filled up to the lower level sensor 117, the replenish control unit 118 closes the electromagnetic valve 105 to stop the supply of hydrofluoric acid, and opens the electromagnetic valve 110 and actuates the pump 108 to supply pure water from the pure water storage tank 107 through the supply pipe 108 to the cleaning solution storage tank 112.
At this time the agitating pump 113 is driven to mix hydrofluoric acid and pure water. When the concentration sensor 115 detects the quasi-azeotropic concentration of 39.4%, the replenish control unit 118 closes the electromagnetic valve 110 and stops the pump 108 to discontinue the supply of pure water.
If the upper level sensor 116 turns on before the concentration sensor 115 detects the quasi-azeotropic concentration of 39.4%, the electromagnetic drain valve 120 is opened to exhaust part of the cleaning solution, and pure water supplied until the cleaning solution comes to the quasi-azeotropic concentration of 39.4%.
The heat of dilution is generated when hydrofluoric acid and pure water are mixed in the cleaning solution storage tank 112. A certain fixed time is necessary for the heat of dilution to lose its influence and for the cleaning solution to attain a uniform concentration throughout. Upon lapse of the fixed time the conditions become stable and the cleaning solution is maintained at the quasi-azeotropic concentration of 39.4%.
The cleaning solution storage tank 112 is connected to the cleaning solution supply pipe 4 described in the first embodiment.
Further, a carrier gas supply pipe 122 is connected to the cleaning solution storage tank 112 for supplying nitrogen gas N 2 as carrier gas. This supply pipe 122 includes an electromagnetic valve 123. The cleaning solution storage tank 112 also includes a pressure sensor 124 for measuring pressure in an upper space thereof.
According to this construction, the electromagnetic valve 123 is opened to supply nitrogen gas N 2 as carrier gas through the supply pipe 122 into the cleaning solution storage tank 112. At this time the nitrogen gas is supplied under a fixed pressure by controlling the electromagnetic valve 123 based on the pressure detected by the pressure sensor 124.
FOURTH EMBODIMENT
FIG. 12 is a schematic view in vertical section of a wafer cleaning apparatus in a fourth embodiment of the invention.
The fourth embodiment is an improvement on the dry cleaning chamber described in the preceding embodiments. A housing 201 contains a hydrofluoric acid tank 202 for storing hydrofluoric acid acting as a cleaning solution. The hydrofluoric acid tank 202 is closed by a top cover 203, and includes a vapor generating region 204 in an upper space thereof in which vapor is generated from hydrofluoric acid.
An inner housing 205 is provided inside the housing 201 and immediately under a bottom wall 202a of the hydrofluoric acid tank 202. The inner housing 205 accommodates a wafer supporting device 206 for supporting wafer W under treatment. A vapor supply section 207 is provided between the undersurface of the bottom wall 202a and wafer W for supplying the vapor of hydrofluoric acid.
As shown in FIG. 13 which is an enlarged sectional view, the wafer supporting device 206 includes a hot plate 208 rotatable on a vertical axis and containing a heater (not shown), and a support shaft 209 rigidly connected to the hot plate 208. The support shaft 209 is operatively connected to an electric motor 210 outside the housing 201 through a belt transmission 211.
A vacuum suction passage 212 extends to the hot plate 208 through the support shaft 209 for maintaining the wafer in position by vacuum suction. The heater contained in the hot plate 208 is controlled by a temperature controller not shown to maintain a surface temperature of the hot plate 208 equal to or above the atmospheric temperature in the vapor supply section 207.
At a level substantially corresponding to the top surface of the hot plate 208, the inner housing 205 and housing 201 define openings 205a and 201a for allowing passage of the wafer W, respectively. Shutters 217 are provided for opening and closing the openings 205a and 201a. A flexion arm type wafer transport mechanism 218 disposed outside the opening 201a of the housing 201 is extendible to a position above the hot plate 208 for transporting the wafer W into and out of the inner housing 205. More particularly, the wafer W is delivered as suction-supported by the transport mechanism 218 through the openings 201a and 205a onto the hot plate 208. Thereafter the transport mechanism 218 is retracted outwardly of the housing 201, then the openings 201a and 205a are closed by shutters 217 and the wafer W is sucked to the hot plate 208. For removing the wafer W outwardly of the housing 201, the above sequence is reversed. That is, the shutters 217 are opened and the wafer W is carried by the transport mechanism 218 outwardly of the housing 201 through the openings 205a and 201a.
Each shutter 217 is movable between opening and closing positions by means of a rack (not shown) and a pinion (not shown), the latter being driven by an electric motor 217a. The shutters 217 may have any desired construction as long as they enable wafer transport and formation of a gastight space.
As shown in FIG. 13, the hydrofluoric acid tank 202 includes hot water piping 219 supported by a holder or holders not shown. The bottom wall 202a of the tank 202 defines a hot water passage 221 therein. Hot water is circulated through a loop made up of a hot water supply pipe 222 shown in FIG. 12, the piping 219, passage 221 and a hot water exhaust pipe 223. The hot water in circulation heats and evaporates hydrofluoric acid stored in the hydrofluoric acid tank 202. Thus, the hot water piping 219 and hot water passage 221 constitute heating means for heating and evaporating hydrofluoric acid. Reference S1 in FIG. 13 denotes a temperature sensor for measuring temperature of hydrofluoric acid in the hydrofluoric acid tank 202. The measured temperature is used to control the amount of hot water flowing through the piping 219 and passage 221, thereby maintaining the temperature of hydrofluoric acid below its boiling point.
When a cleaning solution having a low boiling point is employed, for example, the hot water piping 219 may be omitted, with the hot water passage 221 alone used to heat the cleaning solution. Further, oil may be used as a heating medium instead of hot water.
As shown in FIG. 12, the hydrofluoric acid tank 202 includes an overflow passage 224 having an automatic switch valve 224 mounted in an intermediate position thereof. Hydrofluoric acid having the concentration of 39.4% is supplied initially or as replenishment from a storage tank not shown through a supply pipe 226 until it overflows the tank 202. When an overflow occurs, a valve 227 is closed so that an appropriate amount of hydrofluoric acid is stored in the tank 202. A temperature controlling device may be provided for the hydrofluoric acid supply pipe 226 since it is desirable to preheat hydrofluoric acid supplied therethrough to a predetermined temperature. After the appropriate amount of hydrofluoric acid is stored, the automatic switch valve 225 is closed to prevent the hydrofluoric acid vapor from leaking through the overflow passage 224 during a cleaning treatment. Replenishment is made midway in the cleaning treatment with a suitable timing based on the number of wafers W processed an processing time. The construction for supplying the appropriate amount of hydrofluoric acid into the hydrofluoric acid tank 202 may, for example, include a liquid level gauge in the tank 202 for detecting a reduction to a predetermined amount, on the basis of which an appropriate amount of hydrofluoric acid is supplied.
A vapor supply passage 228 opens to communicate with the vapor generating region 204 at a position above an opening position of the overflow passage 224. An end of the vapor supply passage 224 opens through the bottom of the hydrofluoric acid tank 202 into the vapor supply section 207. A device 229 is provided for automatically opening and closing the vapor supply passage 228.
A carrier gas supply pipe 233 is connected to an upper position of the vapor generating region 204 for supplying nitrogen gas N 2 as a carrier gas. The carrier gas supply pipe 233 includes a valve 234. The carrier gas is used to feed, into the vapor supply passage 228, the hydrofluoric acid vapor collected in the vapor generating region 204 by heating.
A mixing gas supply pipe 235 is connected to the vapor supply section 207 for supplying nitrogen gas N 2 as a mixing gas. The mixing gas supply pipe 235 includes a valve 236.
Though not shown, each of the carrier gas supply pipe 233 and mixing gas supply pipe 235 has a temperature controlling device for maintaining nitrogen gas flowing therethrough to a predetermined temperature.
The vapor supply section 207 includes a vapor scattering porous plate 237 defining a vapor space 238 with the bottom wall 202a of the hydrofluoric acid tank 202. The vapor supply passage 228 communicates with the vapor space 238 for supplying the hydrofluoric acid vapor to the surface of wafer W on the hot plate 208. Hydrofluoric acid in the vapor supply section 207 is maintained at a temperature above its dew point by the heating action of the hot water passage 221 defined in the bottom wall 202a of hydrofluoric acid tank 202 and by the heat from the hot plate 208.
According to the described construction, the hydrofluoric acid tank 202, vapor generating region 204, vapor supply section 207, and vapor supply passage 228 intercommunicating the vapor generating region 204 and vapor supply section 207 are arranged vertically close to one another. These components may, therefore, be heated or temperature-controlled efficiently in a batched manner, to readily prevent condensation of the cleaning vapor flowing therein.
As shown in FIG. 12, a first exhaust pipe 240 having a first flow control valve 239 commmunicates with the interior space of inner housing 205. A second exhaust pipe 242 having a second flow control valve 241 communicates with the space defined between inner housing 205 and outer housing 201. The first and second exhaust pipes 240 and 242 are connected to respective suction devices not shown. The first flow control valve 239 has a larger opening degree than the second flow control valve 241, so that a greater amount of gas is exhausted from inside the inner housing 205 than from the space between the two housings 201 and 205. This exhaust control arrangement is effective for preventing the hydrofluoric acid vapor exhausted after being supplied to the wafer W from leaking outwardly of the apparatus.
In order to increase the displacement of inner housing 205 over that of outer housing 201, the exhaust pipe 240 may have a larger diameter than the exhaust pipe 242, with the two pipes 240 and 242 connected to a common suction device or separate suction devices.
FIFTH EMBODIMENT
FIG. 14 is a sectional view of a fifth embodiment which comprises a wafer supporting device 252 mounted in a housing 251 for holding wafer W by vacuum suction.
The wafer supporting device 252 includes a hot plate 253, and a support shaft 254 extending upwardly rom the hot plate 253 and supported by the housing 251 to be rotatable on a vertical axis. An electric motor M is connected to an upper end of the support shaft 254.
A vapor supply section 256 including a porous plate 255 is disposed under a wafer holding position of the hot plate 253.
The housing 251 defines a hydrofluoric acid tank 257 in a bottom portion thereof for storing a cleaning solution. A hydrofluoric acid strorage tank 260 is connected to this hydrofluoric acid tank 257 through a supply pipe 259 including a pump 258. The hydrofluoric acid tank 257 includes an overflow pipe 261 so that a proper amount of hydrofluoric acid is stored in the hydrofluoric acid tank 257 at initial and replenishing times.
A vapor generating region 262 is defined between an upper surface of the hydrofluoric acid tank 257 and porpous plate 255. A mixing gas supply pipe 263 communicates with the vapor generating region 204 for supplying nitrogen gas N 2 as a carrier gas and mixing gas.
A heater 264 surrounds the housing 251 over a range including the wafer holding position of hot plate 253, vapor supply section 256, vapor generating region 262 and hydrofluoric acid tank 257. The heater 264 acts to maintain hydrofluoric acid in the tank 257 at a temperature below the boiling point and, in combination with the heating action of hot plate 253, maintains the vapor of hydrofluoric acid in the vapor generating region 262 to a temperature above the dew point.
The fourth and fifth embodiments may include the ultraviolet/ozone cleaning chamber described in the third embodiment for eliminating organic contamination from the wafer W.
While, in the foregoing embodiments, the wafer W is spun during the cleaning treatment, the present invention may be embodied as an apparatus in which the wafer W is not spun while being cleaned.
In all of the embodiments described herein, cleaning vapor is produced by heating the cleaning solution. Where a cleaning solution having a boiling point below room temperature is employed, a similar treatment can be effected by cooling the cleaning solution.
Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not be be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims. | 4y
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[0001] The present invention relates to a method of processing bitumen-polymer blends, used in producing modified bituminous membranes of improved quality. Extremely rapid dissolution of polymer into the bitumen is achieved with improved dispersion and minimal air void entrainment. This blend of improved process quality maximizes the waterproofing capability and performance longevity of the resulting coated modified bituminous membrane. Also provided are unique compositions of polymer-asphalt blends with secondary polymer modifiers for membranes that exhibit exemplary heat stability, toughness, flexibility, and rubber like properties.
BACKGROUND OF THE INVENTION
[0002] Asphalt is commonly used to coat fleece or mat like materials to produce membranes or sheet materials that are impervious to water. These membranes or sheet materials are supplied in roll form and are referred as Roll Roofing or Cap Sheets. In a precut form, they are referred to as shingles. The asphalt coating typically contains inorganic filler material to plasticize and extend the asphalt, which has been air blown or oxidized to a predetermined level to prevent flow and deformation from the effects of heat, gravity, foot traffic, etc. in its roof top application. The upper surface typically contains a ceramic coated roofing granule that serves as a weathering and wearing course while the lower surface contains a inorganic mineral material as a parting and anti-stick material agent.
[0003] These types of asphalt coatings are modified with polymers because unmodified air-blown asphalt coatings are brittle, inflexible, and lack strength and durability. The sheet or membrane materials they produce are likewise brittle in nature, often cracking during application. A polymer-modified asphalt coating becomes flexible, has added strength and durability, and also has improved temperature susceptibility. Poor temperature susceptibility for asphalt is defined as having poor physical properties at the low and high ends of the temperature range of actual field use or performance. At cold temperatures, asphalt becomes glassy, brittles, and breaks easily. At high temperatures, the asphalt becomes soft, flows and deforms—all under actual use conditions. Polymer modification with styrene-butadiene-styrene {“SBS”} block co-polymer or atactic polypropylene(APP) improves the low temperature susceptibility. Such an asphalt-polymer blend remains flexible, becomes plastic/elastic and durable. Further, at high temperatures, the asphalt-polymer blend has a higher softening point, higher melting point, and better sag and flow resistance resisting deformation. These types of polymer-modified asphalt coatings are used to coat fleece or mat like reinforcement materials producing Roll Roofing materials called Modified Bituminous Membranes.
[0004] Typical recipes for SBS-asphalt blends consist of thermoplastic block copolymers at 5 to 20 percent by weight, similar to and including, the Kraton D1101, D1184 types, or, of the Phillips Solprene 411 types sold under the EUROPRENE, FINAPRENE, and CALPRENE labels. Typical APP recipes include amorphous polypropylenes or atactic polypropylene at loadings of 15 to 30 percent by weight with an optional amount of crystalline or isotactic polypropylenes(IPP) at loadings of 0 to 5 percent. Examples of APP are Eastman Chemical's ELASTOFLEX M-5H or Huls VESTOPLAST 891. An example of IPP is Iscom's IC-20. In these recipes, the SBS and the APP are primary asphalt modifiers. Prior art formulations do not use secondary polymers to enhance the aging of these polymer asphalt blends.
[0005] Polymer modified asphalt coatings are usually treated at temperatures in the range of from about 300 to about 400 degrees F, to assure that the components are in a fluid state. SBS is typically added in a solid form, although APP may be added in either liquid or solid form, to the molten liquid asphalt. The materials are mixed under heat and agitation until a homogenous blend is achieved. As the polymer disperses within the asphalt under mixing or agitation, the viscosity of the blend increases dramatically. In a manner not unlike that encountered in many kitchen methods, the increase in viscosity under agitation causes entrainment of air as part of the mixing operation. The high viscosity does not allow release of the air, so the modified asphalt has entrained air as the material is moved to the coating operation of the fleece or mat like material. Air voids or pockets, on the order of around 100 to 1000 microns, are formed in the modified bituminous membrane sheet material. The entrapped air causes loss of performance in the modified bituminous membranes. They also cause blisters in the sheet material in field performance. As the air heats or warms up from the heat of sun, it expands, putting the pocket under positive pressure, forming a blister. The constant cycling of expansion and contraction from heating that occurs from the sun during the day and cooling that occurs during the night causes premature physical wear and stress. As a result, the product fails prematurely, causing a breach in the waterproofing integrity of the membrane. These breaches cause even further deteriorate the roof assembly, by allowing water to penetrate the individual components of the roof assembly, where it can freeze and thaw, causing even further damage. Also, some of the larger air voids or pockets can cause incomplete coating and sealing of the reinforcement, creating a direct channel allowing water to penetrate and wick into the fleece/mat reinforcement. Once water penetrates into the fleece or mat material, it spreads, causing delamination of the polymer asphalt coating and widespread material failure.
[0006] The prior art has not taught a process for preventing or minimizing air entrainment in the modified asphalt polymer blend.
SUMMARY OF THE INVENTION
[0007] This and other advantages of the present invention are achieved by producing a roofing membrane comprising a continuous matrix of bitumen modified by addition of a polymer, the matrix being characterized as being substantially free of voids containing entrained air.
[0008] In some embodiments, the modifying polymer is selected from a group consisting of: styrene-butadiene-styrene (“SBS”) block co-polymer, atactic polypropylene (“APP”), and a combination of SBS and APP.
[0009] In some embodiments, the bitumen is selected from the group consisting of straight run asphalts with a rod & ball softening point in the range of from 80 to 130 degrees F.; oxidized asphalts, solvent washed asphalts, road tars, refined tars, and blends thereof.
[0010] In some aspects of the invention, the bitumen is modified by the polymer by adding the polymer to the bitumen while the bitumen is in a molten state in a sealed mixing vessel at a pressure inside the vessel of less than ambient. In other useful aspects of the invention, the bitumen is modified by the polymer by adding the polymer to the bitumen while the bitumen is in a molten state until the polymer is completely dispersed in the bitumen, followed by residence of the modified bitumen in a sealed vessel at a pressure inside the vessel of less than ambient. In either of these cases, the internal pressure in the vessel is at least 15 inches Mercury less than ambient.
[0011] In many aspects of the invention, the modified bitumen continuous matrix embeds a reinforcing mat of fibers. In many aspects, an upper or weathering surface of the membrane is coated with a granular material, particularly a No. 11 ceramic roofing granule. In some embodiments, a lower or non-weathering surface of the membrane is coated with a means for preventing self-adhesion, especially wherein the means for preventing self-adhesion is a fine silica sand.
[0012] The modifying polymer is present in the modified bitumen in the range of from about 5 to about 30 percent by weight.
[0013] In many cases, the bitumen is further modified by a secondary modifying polymer selected from the group consisting of styrene-isoprene styrene (“SIS”), styreneethylene-butylene-styrene (“SEBS”), styrene-ethylene (“SE”) and combinations thereof.
[0014] The modifying polymer is typically added to the bitumen while the bitumen is agitated in a mixer at a temperature in the range of from about 300 to about 400 degrees Fahrenheit.
[0015] In a roofing membrane of the present invention, the roofing membrane exhibits no blistering from entrained air voids after being submerged in water at about 120 degrees F. for 72 hours, then maintained at about 160 degrees F. under at least 15 in. Hg vacuum for up to 48 hours.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The present invention will be best understood when reference is made to the detailed description of the invention and the accompanying drawings, wherein identical parts are identified by identical reference numbers, and wherein:
[0017] [0017]FIG. 1 shows a side sectional view of a modified bituminous membrane as known in the prior art; and
[0018] [0018]FIG. 2 shows a side sectional view of a modified bituminous membrane according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0019] The present invention will be best understood by reference to FIGS. 1 and 2. A modified bituminous membrane 10 as known in the prior art is a sheet material comprising a polymer-asphalt blend 12 saturating or forming a continuous matrix that embeds a fleece or mat like reinforcing inner core 14 . The primary modifiers of the bitumen are SBS and APP. An upper surface or weathering surface of the membrane 10 is typically coated with a ceramic granular material 16 . One such material 16 is sold commercially as No. 11 Roofing Granule. A bottom surface of the membrane typically is coated with a means 18 to prevent sticking or adhesion, especially self-adhesion. One commonly-used means is a fine silica sand. Because of the agitation involved in normal processing of the asphalt polymer blend, air is inherently entrained or entrapped during the mixing process or the dispersion of the polymer in the bitumen matrix. This entrained air results in the creation of air voids 20 in the polymer-asphalt matrix 12 . These voids 20 adversely affect the performance properties of the membrane 10 . In a typical membrane 10 of the prior art, voids 20 comprise a small but measurable amount of the volume of the membrane. This amount of voidage may be estimated through a directly measurable decrease in membrane density.
[0020] The present invention produces a modified bituminous membrane 110 which is previously unknown in the prior art. Like the prior art membrane 10 , it comprises a polymer-asphalt blend 112 saturating or forming a continuous matrix that embeds the fleece or mat like reinforcing inner core 14 . The polymer-asphalt blend 112 is substantially the same composition as the blend 12 of the prior art, but is distinctly different in physical properties due to the difference in the voidage. The upper or weathering surface of the membrane 10 is typically coated with the ceramic granular material 16 . The bottom surface of the membrane typically is coated with the means 18 for preventing sticking or adhesion, especially self-adhesion. The difference between the prior art membrane 10 and the membrane 110 of the present invention is the amount and dispersion of the voids 120 . By dispersing the polymer in the asphalt at a pressure lower than atmospheric, entrained air is reduced or eliminated. By measuring membrane density, the polymer-asphalt blend is observed to have a density which is in the range of 5 to 8% higher when the blend is processed at pressures less than atmospheric. In particular, this level of increase is observed when the processing is conducted at a pressure at least 15 in. Hg lower than atmospheric. As a result, the volumetric portion of the membrane comprising voids is reduced, by reducing either the average size of voids, the average number of voids per unit volume of membrane or both. As a result, the membrane 110 behaves more like a truly continuous matrix of the polymer-asphalt blend than the membrane 10 of the prior art.
[0021] Typical SBS asphalt recipes consist of thermoplastic block copolymers at 5 to 20 percent by weight similar to and including the Kraton types or of the Phillips Solprene types sold under Europrene, Finaprene, Calprene labels. Typical APP recipes include amorphous polypropylenes or attactic polypropylene at loadings of 15 to 30 percent by weight with optional amount of crystalline or isotactic polypropylenes at loadings of 0 to 5 percent. Examples of APP are Eastman Chemical's Elastoflex M-5H or Huls Vestoplast 891 while examples of IPP are Iscom's IC-20.
[0022] In these recipes the SBS and the APP are primary asphalt modifiers, the modifiers that are used to give the polymer asphalt blend it's improved low temperature properties—flexibility, plastic/elastic properties, strength, durability; and, it's improved high temperature properties—high softening point, reduced flow and improved sag/deformation resistance. What has been found and is an object of this invention is the use of secondary polymers to enhance the aging of these polymer asphalt blends. Specifically claimed is StyreneIsoprene-Styrene(SIS), Styrene-Ethylene-Butlyene-Styrene(SEBS), and Styrene-Ethylene(SE) thermoplastic block co-polymers. These polymers, either used by themselves or in conjunction with one another enhance the typical aging characteristics of polymer asphalt blends. These secondary modifiers enhance the properties of the primary polymer asphalt blends by two different distinct mechanisms depending upon the polymer type. SIS's primary mode of degradation with age that occurs is chain scission, that is as it ages the polymer molecule becomes smaller in size and act as a plasticizer/softener for the SBS or APP polymer asphalt blends that becomes brittles with time as it ages losing flexibility and elasticity. SEBS and SE polymers have a hydrogenated polymer backbone that resists degradation, either chain scission or crosslinking(recombination). Withstanding any form of degradation these hydrogenated polymers retain their original properties that contribute to the physical properties of the overall polymer asphalt blend, i.e. flexibility, elasticity, and rubber like properties.
[0023] In processing of polymer modified asphalt coatings, the temperature is usually between 300 and 400 degrees F. to ensure that the components are in a fluid state. The polymer is added in solid form for the case of SBS and in either liquid or solid form for APP to the molten liquid asphalt. The materials are then mixed under heat and agitation until a homogenous blend is achieved. As the polymer disperses within the asphalt under mixing or agitation—the blend increases in viscosity. As the blend mixes with this increase in viscosity, the blend incorporates and entrains air as part of the mixing operation. Often because these blends are so high in viscosity, the air entrained in mixing does not release by itself and transfers to the coating operation of the fleece or mat like material. Air voids or pockets, on the order of around 100 to 1000 microns are formed in the modified bituminous membrane sheet material. These voids or air pockets sacrifice performance of the modified bituminous membranes. These voids or air pockets can cause blisters in the sheet material in field performance. As the air heats or warms up from the heat of sun—it expands putting the pocket under positive pressure forming a blister. Under constant cycling of expansion and contraction from heating that occurs from the sun during the day and cooling that occurs during the night—these pockets or voids undergo excessive physical wear and stress and as a result, fail prematurely causing a break in the water-proofing integrity of the membrane. These breaks in the waterproofing integrity cause the further deterioration of the roof assembly by allowing water to penetrate the individual components of the roof assembly causing even further damage. Also, larger air voids or pockets can cause incomplete coating and sealing of the reinforcement creating a direct channel allowing water to penetrate and wick into the fleece/mat reinforcement. Once water penetrates into the fleece/mat material it eventually spreads causing delamination of the polymer asphalt coating and widespread material failure.
[0024] Laboratory test methods can assess the amount of air voidage, as well as how it correlates to blistering of the modified bituminous membrane. One method of assessment is to form a specimen, typically a square specimen with 6-inch sides, cut from a piece of the formed membrane. The cut edges of the sides are sealed with asphalt to minimize edge effects, particularly lateral migration.. The specimen is immersed in water for 72 hours at a temperature of about 120 degrees F. Porosity in the specimen, especially porosity due to air voidage, allows water to displace air during this immersion. The specimens are transferred immediately to a vacuum oven and maintained at a temperature in the range of about 160 degrees F. with a vacuum in the range of from about 15 to about 25 inches Hg for up to about 48 hours. Blistering from the evaporative release of the water in the pores is directly observable if present. This laboratory blistering may be directly related to a propensity for the same specimen to blister under actual field conditions. The laboratory blistering, if it is to occur, will generally be observed within 48 hours, although many of the cases will exhibit blistering much more quickly, if it is to occur at all.
[0025] While the above describes a specific “pass/fail” test for determining the removal of air voidage from a modified bituminous membrane, it should also be observed that there are also other manners of conducting the determination. For example, in some cases, merely cutting the membrane to form the specimen and observing the matrix of the membrane for visible voidage will be a good predictor of field blistering.
[0026] The present invention teaches that, by applying vacuum or negative pressure in the mixing process, air void formation can be minimized or eliminated. By eliminating and reducing the potential for air void or pocket formation the long term performance of the modified bituminous sheet material can be greatly improved. A preferred mixing unit is the VERSIMIX manufactured by Charles Ross & Sons or equivalent. This unit allows for rapid dissolution of polymer into asphalt to which vacuum or negative pressure can be applied. The mixing unit has three type of mix heads: a mixer/emulsifier head providing high shear and particle size reduction; a high speed disperser head similar to a Cowles type mixer for dispersing solid powder particulate; and, a low speed sweep to keep material moving and flowing over itself. This type of mixing is unique to polymer-asphalt technology, even more so when combined application of vacuum. Polymer asphalt blends are mixed to complete dispersion with filler addition in 30 to 45 minutes, typical vacuum stages are applied for 5 to 15 minutes after dispersion is complete at 15 to 25 inches Hg negative pressure. Typical mixing times for polymer asphalt blends on conventional equipment is two to twenty four hours.
[0027] While a process for applying the deaerating vacuum during the modification of the bitumen with polymer has described in detail, the invention is not limited to only that particular process. Specifically, the polymer modification of the bitumen greatly increases viscosity, which also increases the entrainment of air during mixing. The critical aspect of the invention, as viewed by the inventors, is that the bitumen, once modified to increase the viscosity, should be allowed to release any entrained air through a vacuum treatment before being formed into the membrane and certainly after any vigorous mixing procedure. The deaeration procedure may be at the end of the blending step in the same vessel, it may be in a separate vessel after the blending step and it may even be achieved using in-line deaeration techniques while pumping the modified bitumen at the point of forming the membrane. | 4y
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